DEGRADABLE FILAMENT, PREPARATION METHOD THEREFOR, AND USE THEREOF

Description

TECHNICAL FIELD

The present disclosure relates to the technical field of biodegradable materials, and in particular relates to a degradable filament and a specific material thereof.

BACKGROUND

Along with popularization of environmental protection concepts such as carbon peaking and carbon neutrality, the demand for biodegradable materials is growing. The research on degradable materials has gradually expanded from the application fields of plastics such as various injection molding materials, film materials, and sheet materials to the fields such as rubber, leather, or textile. Among these, the preparation of novel fibers using degradable materials has become a research hotspot, which has expanded new chemical fiber types and enabled greater potential for the two major application fields: textile and non-woven fields.

Polyhydroxyalkanoate (PHA), as an emerging material of purely biological origin and 100% degradability, demonstrates more eco-friendly and more bio-friendly production, purification, and application processes compared with degradable materials such as polylactic acid (PLA), polybutylene succinate (PBS), Poly (butyleneadipate-co-terephthalate) (PBAT), and polypropylene carbonate (PPC). Notably, PHA requires no petroleum-based industrial products as synthetic feedstocks. Furthermore, PHA exhibits lower environmental demands for degradation, achieving natural degradation without requiring composting. These characteristics render PHA fully compliant with carbon peaking and carbon neutrality principles, making it a truly full life-cycle environment-friendly material.

However, the application of PHA in textile and non-woven fields remains in the exploratory phase, where it is typically blended with materials such as PLA, PBAT, and PPC to enhance spinnability. Nevertheless, PHA constitutes only a small proportion in such blends, particularly in finished apparel or other products where its content often falls below 10%, thereby failing to fully utilize its advantages including rapid degradation, bioaffinity, antibacterial properties, and ease of dyeing. Furthermore, incompatibility between blended materials can easily lead to instability in the overall material. Consequently, there is an urgent need to develop appropriate formulations and processing methods for pure PHA-based filaments.

The patent document CN114262952A provides a composite material, which is composed of skin layer component A and core layer component B. In the component A, PHA serves as the primary component, and in the component B, nylon serves as the primary component. This configuration combines PHA's advantages of dyeability and full biodegradability with nylon's advantages of high toughness and high strength, resulting in a composite filament with a skin-core structure. However, the presence of nylon prevents the material from achieving full biodegradability. Moreover, the elevated processing temperatures required for the nylon core layer lead to incomplete encapsulation of the core by the PHA of the skin layer. This incomplete encapsulation results in compromised performance stability of the resultant filaments.

The patent document CN111501117A discloses a method for preparing PLA/PHA fibers using an in-line preparation device combined with a specific ratio, which enhances fiber quality and mechanical properties while effectively reducing costs. However, the proportion of PHA remains very low in the resultant fibers, failing to achieve a PHA-dominant fiber. Consequently, the fibers exhibit poor performance in dyeing properties and heat resistance.

The patent document CN109183191B discloses a method for preparing flexible blended fibers by melt-extruding blended chips of P3HB4HB and PLA to form nascent fibers, followed by static placement and thermal drawing. However, the PHA content in the fibers does not exceed 40%, thereby failing to establish PHA as the primary component. In addition, the raw materials undergo repeated heating-cooling cycles through processes including melt-granulating, melting to prepare chips, melt-extruding nascent fibers, and thermal drawing, which easily induce degradation or thermal decomposition, resulting in diminished material properties and inconsistent quality of the final fibers. Furthermore, the extremely low draw ratio and the relatively slow spinning machine speed during production adversely affect manufacturing efficiency.

The patent document CN102392318A discloses a bio-based degradable fiber obtained by combining PHA (PHBV) with PLA. This fiber demonstrates improved spinnability at relatively low spinning temperatures and relatively high spinning speeds, while exhibiting enhanced mechanical strength and consistently stable softness. The preparation method effectively increases production efficiency and reduces costs. However, PLA constitutes a significant proportion of the composite material. The process relies solely on physical blending of the two materials without employing additional modification methods to enhance processability of the materials, resulting in suboptimal overall heat resistance.

The patent document CN114318588A discloses a blend of PHA (P4HB) and PLA modified with reactive and physical compatibilizers, significantly enhancing the compatibility between the two materials to improve fiber toughness and strength. While PHA serves as the primary component, the second-stage drawing temperature during processing is insufficiently high, which intensifies post-crystallization phenomena. This results in diminished mechanical performance (i.e., embrittlement) and is not conducive to the improvement of efficiency.

The patent document CN105603569A discloses a method where carbon nanotubes are blended with PHBHHx, unexpectedly accelerating crystallization rates and thereby enhancing spinning efficiency and reducing costs. However, the method employs post-crystallization stretching and orientation followed by tension heat setting. The excessively slow melt-extruding speed necessitates a high stretching ratio during stretching. Yet, since the stretching temperature is only marginally higher than the crystallization temperature, crystallization continues during the stretching and orientation phase. This combination of the high stretching ratio and the low stretching temperature easily induces filament breakage, rendering the process unstable.

Based on the patent documents described above, few reports exist on pure PHA-based filaments or fibers. Most PHA-containing fiber preparation methods encounter challenges such as slow crystallization rates, inter-fiber adhesion, low strength, poor toughness, and narrow processing windows. Consequently, there is a need in the art to develop filaments and preparation methods therefor that address issues including low melt strength, poor thermal stability, slow crystallization rates, weak mechanical properties, and severe adhesion during PHA spinning.

SUMMARY

The objective of the present disclosure is to overcome the drawbacks of existing technologies in preparing filament materials using PHA. By employing appropriate auxiliary agents and a pure PHA material as a base material, the processability of PHA is enhanced. Furthermore, through specialized processing techniques, the comprehensive performance of pure PHA filaments, particularly mechanical properties and antibacterial efficacy, is further improved. The present disclosure addresses challenges such as low melt strength, poor thermal stability, slow crystallization rates, weak mechanical properties, and severe adhesion during PHA spinning, thereby expanding its applicability in textile and non-woven fields.

In a first aspect, provided is a filament. The filament (or a raw material thereof) comprises a base material and an auxiliary agent.

The base material comprises, by mass percentage, PHA in any value in the range of 50% to 100%, preferably any value in the range of 80% to 100%, such as 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, or 100% PHA.

Preferably, the filament (or the raw material thereof) comprises a base material and an auxiliary agent, wherein the base material is PHA.

Further preferably, the filament (or the raw material thereof) comprises PHA and an auxiliary agent. In one specific embodiment of the present disclosure, the filament (or the raw material thereof) is prepared from the PHA and the auxiliary agent. Preferably, the filament uses PHA as the primary raw material and is physically or chemically modified by the addition of various auxiliary agents. Preferably, a mass ratio of the base material to the auxiliary agent is any value in the range of (50-150):(0.1-28), such as (50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, or 150):(0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, or 28), such as 50:0.1, 100:0.1, 150:0.1, 100:5.75, 100:7.5, 100:7.75, 100:8.25, 100:8.5, 100:10.35, 50:14.05, 100:14.05, 100:14.5, 100:16.5, 100:16.75, 150:14.05, 100:20.5, 50:28, 100:28, or 150:28.

The auxiliary agent can be any known auxiliary agent in the existing technology, which can physically or chemically modify PHA.

The auxiliary agent includes, but is not limited to, one or a combination of two or more of a nucleating agent, a reinforcing agent, a nanomaterial, tetrachlorophthalic anhydride, a heat stabilizer, a chain extender, an antioxidant, a hydrolysis-resistant agent, an anti-blocking agent, a crosslinking agent, a coupling agent, and a plasticizer.

Preferably, the auxiliary agent includes a nanomaterial. Further preferably, the nanomaterial includes, but is not limited to, one or a combination of two or more of nano-magnesia, nano-calcium carbonate, fumed nano-silica, nanocellulose, nano-zinc oxide, nano-titanium boride, or nano-titanium carbide.

Preferably, a mass ratio of the PHA to the nanomaterial is any value in the range of 100:0.0001 to 100:4, preferably any value in the range of 100:0.0001 to 100:3.25 or 100:1 to 100:4, such as 100:0.0001, 100:0.001, 100:0.01, 100:0.1, 100:0.2, 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9, 100:1, 100:1.25, 100:1.5, 100:1.6, 100:1.7, 100:1.75, 100:1.8, 100:1.9, 100:2, 100:2.25, 100:2.5, 100:2.75, 100:3, 100:3.25, 100:3.5, or 100:4.

Preferably, the auxiliary agent includes a nucleating agent and/or a reinforcing agent.

Further preferably, the nucleating agent includes, but is not limited to, one or a combination of two or more of nano-magnesia, nano-calcium carbonate, MILLAD 3905, MILLAD 3988, NA-21, or ACLYN 285A.

Further preferably, the reinforcing agent includes, but is not limited to, one or a combination of two or more of fumed nano-silica, talc, nanocellulose, DH-2 reinforcing agent, DH-3 reinforcing agent, DH-4 reinforcing agent, or tetrachlorophthalic anhydride. Further preferably, the reinforcing agent includes at least tetrachlorophthalic anhydride.

Preferably, a mass ratio of the nucleating agent to the reinforcing agent is any value in the range of (0.0001-5):(0.1-25), further preferably any value in the range of (0.0001-3):(0.1-18), (0.2-3):(1-20), or (0.2-3):(1-18), such as (0.0001, 0.0002, 0.001, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.55, 0.6, 0.7, 0.75, 0.8, 0.9, 1, 2, 3, 4, or 5):(0.1, 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25).

In one specific embodiment of the present disclosure, the mass ratio of the nucleating agent to the reinforcing agent is 0.75:5.

In one specific embodiment of the present disclosure, the auxiliary agent includes a nanomaterial and tetrachlorophthalic anhydride; preferably, the nanomaterial includes nano-magnesia, nano-calcium carbonate, fumed nano-silica, or nanocellulose.

In one specific embodiment of the present disclosure, a mass ratio of the PHA to tetrachlorophthalic anhydride is any value in the range of 100:0.05 to 100:5, preferably any value in the range of 100:1.5 to 100:2, such as 100:0.05, 100:0.1, 100:0.5, 100:1, 100:1.5, 100:1.6, 100:1.7, 100:1.8, 100:1.9, 100:2, 100:3, 100:4, or 100:5.

Preferably, the auxiliary agent further includes one or a combination of two or more of a heat stabilizer, a chain extender, an antioxidant, a hydrolysis-resistant agent, an anti-blocking agent, a crosslinking agent, a coupling agent, and a plasticizer.

Preferably, the auxiliary agent further includes a heat stabilizer. Further preferably, the heat stabilizer includes, but is not limited to, one or a combination of two or more of magnesium 2-ethylhexanoate, zinc 2-ethylhexanoate, zinc stearate, calcium stearate, calcium laurate, or magnesium laurate.

Preferably, the auxiliary agent further includes a chain extender. Further preferably, the chain extender includes, but is not limited to, one or a combination of two or more of BASF ADR 4300F, BASF ADR 4400, Vertellus E60P, 1,3-bis(4,5-dihydrooxazol-2-yl)benzene, trimethylolpropane, and EK-145 polyester chain extender.

Preferably, the auxiliary agent further includes an antioxidant. Further preferably, the antioxidant includes, but is not limited to, one or a combination of two or more of antioxidant CA, LOWINOX 44B25, antioxidant RIANOX 1098, antioxidant RIANOX 1790, antioxidant RIANOX 168, or antioxidant RIANOX 626.

Preferably, the auxiliary agent further includes a hydrolysis-resistant agent. Further preferably, the hydrolysis-resistant agent includes, but is not limited to, one or a combination of two or more of polycarbodiimide UN-03, double bond hydrolysis-resistant agent CHINOX P-500, DuPont 132F NC010, anti-hydrolysis stabilizer 3600, or KANEKA M732.

Preferably, the auxiliary agent further includes an anti-blocking agent. Further preferably, the anti-blocking agent includes, but is not limited to, one or a combination of two or more of oleamide, stearamide, BYK3700 organosilicon leveling agent, silica opening agent AB-MB-09, or antistatic agent MOA3-PK.

Preferably, the auxiliary agent further includes a crosslinking agent, such as an environment-friendly crosslinking agent. Further preferably, the environment-friendly crosslinking agent includes, but is not limited to, one or a combination of two or more of hydroxypropyl methacrylate, methyltriethoxysilane, HTDI, DAP, N-(isobutoxymethyl)acrylamide, multifunctional aziridine crosslinking agent SaC-100, aluminum citrate, and multifunctional polycarbodiimide UN-557.

Preferably, the auxiliary agent further includes a coupling agent, such as an environment-friendly coupling agent. Further preferably, the environment-friendly coupling agent includes, but is not limited to, one or a combination of two or more of silane coupling agent Z-6020, silane coupling agent KH-550, silane coupling agent KBM-602, TTS, or KR-38S.

Preferably, the auxiliary agent further includes a plasticizer, such as an environment-friendly plasticizer. Further preferably, the environment-friendly plasticizer includes, but is not limited to, one or a combination of two or more of TBC, ATBC, or BNTXIB.

Preferably, a mass content of the PHA in the filament (or the raw material thereof) is any value in the range of 64.10% to 99.933% (preferably 72% to 99%), such as 64.10%, 65%, 70%, 72%, 75%, 80%, 85%, 87%, 90%, 95%, 98%, 99%, or 99.933%.

Preferably, a mass content of the auxiliary agent in the filament (or the raw material thereof) is any value in the range of 0.067% to 35.90% (preferably 1% to 28% or 0.67% to 35.90%), such as 0.067%, 0.67%, 1%, 5%, 10%, 11%, 12%, 13%, 15%, 20%, 25%, 28%, 30%, 35%, or 35.90%.

Preferably, a mass ratio of the PHA to the auxiliary agent is any value in the range of (50-150):(0.1-28), such as 50:0.1, 100:0.1, 150:0.1, 100:5.75, 100:7.5, 100:7.75, 100:8.25, 100:8.5, 100:10.35, 50:14.05, 100:14.05, 100:14.5, 100:16.5, 100:16.75, 150:14.05, 100:20.5, 50:28, 100:28, or 150:28.

In one specific embodiment of the present disclosure, the filament (or the raw material thereof) comprises 100 parts of the PHA and 14.5 parts of the auxiliary agent.

Preferably, the PHA can be any known PHA in the existing technology, with any molecular weight, such as in the range of 300,000 to 6,000,000 (specifically, 300,000, 500,000, 1,000,000, 2,000,000, 3,000,000, 4,000,000, 5,000,000, or 6,000,000). The PHA can be prepared by any method, such as bacterial fermentation or chemical synthesis.

Further preferably, the PHA includes, but is not limited to, a homopolymer, a random copolymer, and a block copolymer of any one or two or more of 3-hydroxypropionic acid (3HP), 3-hydroxybutyric acid, 3-hydroxyvaleric acid, 3-hydroxyhexanoic acid, 4-hydroxybutyric acid, 5-hydroxyvaleric acid, or a derivative thereof. More preferably, the PHA includes, but is not limited to, one or a combination of two or more of poly-3-hydroxybutyrate (PHB), poly-3-hydroxyvalerate (PHV), poly-3-hydroxypropionate (P3HP), a copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid (PHBV), poly-3-hydroxyoctanoate (PHO), poly-3-hydroxynonanoate (PHN), a copolymer of 3-hydroxybutyric acid and 4-hydroxybutyric acid (P3HB4HB), a copolymer of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid (PHBHHx), a copolymer of 3-hydroxybutyric acid, 4-hydroxybutyric acid, and 3-hydroxyvaleric acid (P3HB4HB3HV), or a copolymer of 3-hydroxybutyric acid, 4-hydroxybutyric acid, and 5-hydroxyvaleric acid (P3HB4HB5HV).

Preferably, the PHA includes, but is not limited to, one or a combination of two or more of PHB, P3HB4HB, PHBHHx, PHBV, P3HB4HB3HV, and P3HB4HB5HV.

Preferably, a molar content of the 3HV in the PHBV is any value in the range of 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

Preferably, a molar content of the 4HB in the P3HB4HB is any value in the range of 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

Preferably, a molar content of the HHx in the PHBHHx is any value in the range of 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

Preferably, a molar content of the 4HB or 3HV in the P3HB4HB3HV is any value in the range of 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

Preferably, a molar content of the 4HB or 5HV in the P3HB4HB5HV is any value in the range of 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

Depending on the requirements of the specific embodiment, the PHA may be a single type or a combination of two or more types.

In one embodiment of the present disclosure, the PHA includes a blend of the PHB and the P3HB4HB in a mass ratio range of 1:10 to 10:1, such as 1:10, 5:10, 10:10, 20:10, 30:10, 40:10, 50:10, 60:10, 70:10, 80:10, 90:10, or 100:10.

In one embodiment of the present disclosure, the PHA includes a blend of the PHB and the PHBV in a mass ratio range of 1:10 to 10:1, such as 1:10, 5:10, 10:10, 20:10, 30:10, 40:10, 50:10, 60:10, 70:10, 80:10, 90:10, or 100:10.

In one embodiment of the present disclosure, the PHA includes a blend of the PHB and the PHBHHx in a mass ratio range of 1:10 to 10:1, such as 1:10, 5:10, 10:10, 20:10, 30:10, 40:10, 50:10, 60:10, 70:10, 80:10, 90:10, or 100:10.

In one embodiment of the present disclosure, the PHA includes a blend of the PHB, the P3HB4HB, and the PHBV in a mass ratio range of (1-10):(1-6):(1-4), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, 4, 5, or 6):(1, 2, 3, or 4).

In one embodiment of the present disclosure, the PHA includes a blend of the PHB, the P3HB4HB, and the PHBHHx in a mass ratio range of (1-10):(1-5):(1-5), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, 4, or 5):(1, 2, 3, 4, or 5).

In one embodiment of the present disclosure, the PHA includes a blend of the PHB, the PHBV, and the PHBHHx in a mass ratio range of (1-10):(1-4):(1-6), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, or 4):(1, 2, 3, 4, 5, or 6).

In one embodiment of the present disclosure, the PHA includes a blend of the PHB, the PHBV, the PHBHHx, and the P3HB4HB in a mass ratio range of (1-15):(1-4):(1-5):(1-6), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15):(1, 2, 3, or 4):(1, 2, 3, 4, or 5):(1, 2, 3, 4, 5, or 6);

• • a blend of the PHB and the P3HB4HB3HV in a mass ratio range of 1:10 to 10:1, such as 1:10, 5:10, 10:10, 20:10, 30:10, 40:10, 50:10, 60:10, 70:10, 80:10, 90:10, or 100:10;
  • a blend of the PHB and the P3HB4HB5HV in a mass ratio range of 1:10 to 10:1, such as 1:10, 5:10, 10:10, 20:10, 30:10, 40:10, 50:10, 60:10, 70:10, 80:10, 90:10, or 100:10;
  • a blend of the PHB, the P3HB4HB3HV, and the P3HB4HB5HV in a mass ratio range of (1-10):(1-4):(1-5), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, or 4):(1, 2, 3, 4, or 5);
  • a blend of the PHB, the PHBV, and the P3HB4HB3HV in a mass ratio range of (1-10):(1-5):(1-6), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, 4, or 5):(1, 2, 3, 4, 5, or 6);
  • a blend of the PHB, the PHBV, and the P3HB4HB5HV in a mass ratio range of (1-10):(1-5):(1-6), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, 4, or 5):(1, 2, 3, 4, 5, or 6);
  • a blend of the PHB, the PHBHHx, and the P3HB4HB3HV in a mass ratio range of (1-10):(1-4.5):(1-5.5), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5):(1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, or 5.5);
  • a blend of the PHB, the PHBHHx, and the P3HB4HB5HV in a mass ratio range of (1-10):(1-4.5):(1-5.5), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5):(1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, or 5.5);
  • a blend of the PHB, the P3HB4HB, and the P3HB4HB3HV in a mass ratio range of (1-10):(1-5):(1-4.5), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, 4, or 5):(1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5);
  • a blend of the PHB, the P3HB4HB, and the P3HB4HB5HV in a mass ratio range of (1-10):(1-5):(1-4.5), such as (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10):(1, 2, 3, 4, or 5):(1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5);

In one embodiment of the present disclosure, in parts by mass, the PHA is 75 parts of PHB and 25 parts of P3HB4HB. In another embodiment of the present disclosure, the PHA is 55 parts of PHB and 45 parts of PHBV. In another embodiment of the present disclosure, the PHA is 65 parts of PHB, 20 parts of PHBHHx, and 15 parts of P3HB4HB. In another embodiment of the present disclosure, the PHA is 65 parts of PHB, 15 parts of PHBV, and 20 parts of P3HB4HB. In another embodiment of the present disclosure, the PHA is 65 parts of PHB, 22 parts of PHBHHx, and 13 parts of PHBV. In another embodiment of the present disclosure, the PHA is 55 parts of PHB, 18 parts of PHBHHx, 10 parts of PHBV, and 17 parts of P3HB4HB. In another embodiment of the present disclosure, the PHA is 80 parts of PHB and 20 parts of P3HB4HB3HV. In another embodiment of the present disclosure, the PHA is 82 parts of PHB and 18 parts of P3HB4HB5HV. In another embodiment of the present disclosure, the PHA is 81 parts of PHB, 10 parts of P3HB4HB3HV, and 9 parts of P3HB4HB5HV. In another embodiment of the present disclosure, the PHA is 70 parts of PHB, 12 parts of PHBV, and 18 parts of P3HB4HB3HV. In another embodiment of the present disclosure, the PHA is 70 parts of PHB, 14 parts of PHBV, and 16 parts of P3HB4HB5HV. In another embodiment of the present disclosure, the PHA is 72 parts of PHB, 14 parts of PHBHHx, and 14 parts of P3HB4HB3HV. In another embodiment of the present disclosure, the PHA is 72 parts of PHB, 16 parts of PHBHHx, and 12 parts of P3HB4HB5HV. In another embodiment of the present disclosure, the PHA is 75 parts of PHB, 12 parts of P3HB4HB, and 13 parts of P3HB4HB3HV. In another embodiment of the present disclosure, the PHA is 75 parts of PHB, 15 parts of P3HB4HB, and 10 parts of P3HB4HB5HV.

In one specific embodiment of the present disclosure, the filament (or the raw material thereof) comprises, in parts by mass:

• • the PHA: any value in the range of 50 parts to 150 parts, such as 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, or 150 parts; and
  • the auxiliary agent: any value in the range of 0.1 parts to 28 parts, such as 0.1 parts, 1 part, 1.5 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 7.5 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 14.5 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 25 parts, or 28 parts.

Preferably, the auxiliary agent comprises:

• • the heat stabilizer: any value in the range of 0 parts to 2.5 parts, such as 0 parts, 0.1 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.9 parts, 1.0 part, 1.1 parts, 1.2 parts, 1.25 parts, 1.3 parts, 1.5 parts, 2 parts, 2.4 parts, or 2.5 parts;
  • the nucleating agent: any value in the range of 0.0001 parts to 1.5 parts, such as 0.0001 parts, 0.001 parts, 0.01 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.9 parts, 1.0 part, or 1.5 parts;
  • the chain extender: any value in the range of 0 parts to 2.5 parts, such as 0 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 part, 1.1 parts, 1.2 parts, 1.25 parts, 1.3 parts, 1.4 parts, 1.5 parts, 2 parts, or 2.5 parts;
  • the antioxidant: any value in the range of 0 parts to 1.5 parts, such as 0 parts, 0.1 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.9 parts, 1.0 part, or 1.5 parts;
  • the hydrolysis-resistant agent: any value in the range of 0 parts to 1.5 parts, such as 0 parts, 0.1 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.9 parts, 1.0 part, or 1.5 parts;
  • the reinforcing agent: any value in the range of 0.1 parts to 10.0 parts, such as 0.1 parts, 0.5 parts, 1.0 part, 1.5 parts, 2.0 parts, 2.5 parts, 3.0 parts, 3.5 parts, 4.0 parts, 4.5 parts, 5.0 parts, 7.0 parts, 9.0 parts, or 10.0 parts;
  • the anti-blocking agent: any value in the range of 0 parts to 2.0 parts, such as 0 parts, 0.1 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.9 parts, 1.0 part, 1.5 parts, or 2.0 parts;
  • the crosslinking agent: any value in the range of 0 parts to 2.5 parts, such as 0 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 part, 1.1 parts, 1.2 parts, 1.25 parts, 1.3 parts, 1.4 parts, 1.5 parts, 2.0 parts, or 2.5 parts;
  • the coupling agent: any value in the range of 0 parts to 3.0 parts, such as 0 parts, 0.1 parts, 0.3 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, 1.0 part, 1.1 parts, 1.2 parts, 1.25 parts, 1.3 parts, 1.4 parts, 1.5 parts, 2.0 parts, 2.5 parts, or 3.0 parts; and
  • the plasticizer: any value in the range of 0 parts to 2.0 parts, such as 0 parts, 0.1 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.9 parts, 1.0 part, 1.5 parts, or 2.0 parts.

Preferably, the molecular weight of the PHA is any value in the range of 300,000 to 6,000,000.

Preferably, the form of the filament includes, but is not limited to, POY, FDY, and DTY.

PHA serves as the primary component in the filament (or the raw material thereof) described in the present disclosure (e.g., with a mass percentage greater than 60% in the entire product). It can be the sole degradable component, and additional common degradable materials may be included in the filament or the raw material thereof, such as PLA, PBAT, PPC, PBS, and nylon. However, these common degradable materials do not serve as the primary components (e.g., with a mass percentage less than 20% in the entire product).

In a second aspect, provided is a preparation method for the filament-specific material described above, which comprises:

• • step I: vacuum-drying the raw materials; and
  • step II: weighing the raw materials, physically mixing them using a high-speed mixer, and subsequently melt-extruding the mixture through a twin-screw extruder, and cooling and granulating the extrudate via air-cooling to obtain filament-specific granules.

Preferably, a drying temperature in step I is any value in the range of 60° C. to 105° C., such as 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C., or 105° C.

Preferably, a drying time in step I is any value in the range of 2 h to 12 h, such as 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, or 12 h.

Preferably, a moisture content in step I is controlled to be no more than 180 ppm.

Preferably, a physical mixing time in step II is any value in the range of 10 min to 60 min, such as 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

Preferably, a barrel temperature in step II is set to any value in the range of 140° C. to 220° C., such as 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., 210° C., or 220° C.

Preferably, an air supply temperature in step II is any value in the range of 5° C. to 75° C., such as 5° C., 10° C., 15° C., 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C., or 75° C.

The raw material comprises a base material. The base material comprises PHA.

Preferably, the raw material further comprises an auxiliary agent.

The base material and the PHA are as defined above according to the first aspect.

The auxiliary agent is as defined above according to the first aspect.

In a third aspect, provided is a preparation method for the filament described above, which comprises melt-granulating raw materials followed by spinning to obtain the filament.

Preferably, the preparation method comprises melt-granulating the raw materials followed by a primary spinning process.

The raw materials comprise a base material and an auxiliary agent. Preferably, the base material comprises PHA.

The base material and the PHA are as defined above according to the first aspect.

The auxiliary agent is as defined above according to the first aspect.

Melt-granulating the raw materials involves mixing the raw materials in a barrel, subsequently melt-extruding the mixture using a twin-screw extruder, and cooling and granulating the extrudate via air-cooling to obtain filament-specific granules. Preferably, the barrel temperature is set to any value in the range of 140° C. to 220° C., preferably any value in the range of 150° C. to 210° C., such as 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., 210° C., or 220° C. Preferably, the air supply temperature is any value in the range of 5° C. to 75° C., such as 5° C., 10° C., 15° C., 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C., or 75° C.

Preferably, the filament-specific granules are first dried and subsequently subjected to the primary spinning process. Preferably, the drying controls the moisture content to no more than 180 ppm.

Preferably, the drying is vacuum-drying with the temperature set to any value in the range of 60° C. to 105° C., such as 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C., or 105° C.

The drying time can be adjusted according to the drying temperature, preferably any value in the range of 1 h to 12 h, further preferably any value in the range of 1 h to 4 h, such as 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h, 10 h, 10.5 h, 11 h, 11.5 h, or 12 h.

The primary spinning process comprises simultaneous cooling and stretching.

Preferably, the simultaneous cooling and stretching includes simultaneous water-cooling and stretching or simultaneous air-cooling and stretching.

Preferably, a water-cooling temperature during the simultaneous water-cooling and stretching is any value in the range of 0° C. to 30° C., further preferably any value in the range of 4° C. to 25° C., 4° C. to 10° C., or 4° C. to 15° C., such as 0° C., 1° C., 2° C., 3° C., 4° C., 5° C., 6° C., 7° C., 8° C., 9° C., 10° C., 11° C., 12° C., 13° C., 14° C., 15° C., 16° C., 17° C., 18° C., 19° C., 20° C., 21° C., 22° C., 23° C., 24° C., 25° C., 26° C., 27° C., 28° C., 29° C., or 30° C.

Preferably, a stretching ratio during the simultaneous water-cooling and stretching is any value in the range of 2 to 12, further preferably in the range of 4 to 12, 6 to 10, or 4 to 10, such as 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, or 12.

Preferably, an antistatic agent is added to the water during the simultaneous water-cooling and stretching. Preferably, an amount of the antistatic agent added is any value in the range of 0.05% to 0.3%, such as 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. The antistatic agent includes, but is not limited to, one or a combination of two or more of Tween 20, Tween 40, and Tween 60.

In one specific embodiment of the present disclosure, 0.15% Tween 40 is added to the water during the simultaneous water-cooling and stretching.

In one specific embodiment of the present disclosure, the water-cooling is performed in a horizontal water tank with a length of any required value, such as 0.5 m, 1 m, 2 m, 3 m, 4 m, 5 m, or longer.

A temperature of the primary spinning process is any value in the range of 150° C. to 210° C., preferably any value in the range of 160° C. to 200° C. or 165° C. to 195° C., such as 150° C., 160° C., 165° C., 170° C., 175° C., 180° C., 185° C., 190° C., 195° C., 200° C., or 210° C.

A pressure of the primary spinning process is any value in the range of 5 MPa to 15 MPa, preferably any value in the range of 6 MPa to 13 MPa, such as 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, or 15 MPa.

An extrusion speed of the primary spinning process is any value in the range of 40 m/min to 200 m/min, preferably any value in the range of 60 m/min to 100 m/min or 40 m/min to 120 m/min, such as 40 m/min, 50 m/min, 60 m/min, 70 m/min, 80 m/min, 90 m/min, 100 m/min, 110 m/min, 120 m/min, 130 m/min, 140 m/min, 150 m/min, 160 m/min, 170 m/min, 180 m/min, 190 m/min, or 200 m/min.

The number of spinneret holes set for the primary spinning process is single-hole, 12, 24, 36, 48, 60, 72, 84, 96, or more.

The primary spinning process is followed by drying, oiling, and a forming process.

The drying is performed using an annular air-blowing duct. Preferably, the air supply temperature is any value in the range of 35° C. to 105° C., preferably any value in the range of 40° C. to 100° C., 50° C. to 100° C., or 85° C. to 102° C., such as 35° C., 40° C., 45° C., 50° C., 60° C., 70° C., 80° C., 85° C., 90° C., 95° C., 100° C., 102° C., or 105° C. Preferably, the annular air-blowing duct is vertically positioned with a length of any required value, preferably any value in the range of 1.5 m to 5 m, such as 1 m, 1.5 m, 2 m, 2.5 m, 3 m, 3.5 m, 4 m, 4.5 m, 5 m, 6 m, 7 m, 8 m, 9 m, 10 m, or longer.

The drying is performed simultaneously with oiling.

Preferably, the oiling is performed using an oiling roller. Preferably, a speed at the oiling roller is any value in the range of 400 m/min to 1,600 m/min, preferably any value in the range of 600 m/min to 1,400 m/min, 1,000 m/min to 1,500 m/min, 1,200 m/min to 1,400 m/min, or 480 m/min to 1,440 m/min, such as 400 m/min, 450 m/min, 480 m/min, 500 m/min, 600 m/min, 700 m/min, 800 m/min, 900 m/min, 1,000 m/min, 1,050 m/min, 1,100 m/min, 1,150 m/min, 1,200 m/min, 1,250 m/min, 1,300 m/min, 1,350 m/min, 1,400 m/min, 1,440 m/min, 1,450 m/min, 1,500 m/min, 1,550 m/min, or 1,600 m/min.

The forming process comprises sequentially feeding the oiled strand through two or more godet rollers, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10 godet rollers, preferably 3 godet rollers, and subsequently collecting the filament. Stretching occurs between the subsequent godet roller and the preceding godet roller.

Preferably, the forming process comprises sequentially feeding the oiled strand through a first godet roller, a second godet roller, and a third godet roller, and subsequently collecting the filament.

Preferably, stretching occurs between the first godet roller and the second godet roller, with the stretching ratio controlled to any value in the range of 1.5 to 4, such as 1.5, 2, 2.5, 3, 3.5, or 4.

The first godet roller is set at a temperature of any value in the range of 25° C. to 90° C., preferably any value in the range of 45° C. to 70° C., such as 25° C., 35° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C., 80° C., or 90° C.

The first godet roller is set at a speed of any value in the range of 500 m/min to 2,000 m/min, preferably any value in the range of 1,200 m/min to 1,800 m/min, 1,300 m/min to 1,500 m/min, or 750 m/min to 1,750 m/min, such as 500 m/min, 600 m/min, 700 m/min, 750 m/min, 800 m/min, 900 m/min, 1,000 m/min, 1,100 m/min, 1,200 m/min, 1,300 m/min, 1,350 m/min, 1,400 m/min, 1,450 m/min, 1,500 m/min, 1,600 m/min, 1,700 m/min, 1,750 m/min, 1,800 m/min, 1,900 m/min, or 2,000 m/min.

The second godet roller is set at a temperature of any value in the range of 70° C. to 115° C., preferably any value in the range of 75° C. to 110° C., such as 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C., 105° C., 110° C., or 115° C.

The second godet roller is set at a speed of any value in the range of 1,500 m/min to 5,500 m/min, preferably any value in the range of 2,400 m/min to 4,800 m/min, 3,000 m/min to 4,200 m/min, or 2,800 m/min to 4,200 m/min, such as 1,500 m/min, 1,800 m/min, 2,000 m/min, 2,200 m/min, 2,400 m/min, 2,500 m/min, 2,800 m/min, 3,000 m/min, 3,200 m/min, 3,300 m/min, 3,500 m/min, 3,800 m/min, 4,000 m/min, 4,200 m/min, 4,500 m/min, 4,800 m/min, 5,000 m/min, 5,200 m/min, or 5,500 m/min.

The third godet roller is set at a speed of any value in the range of 1,750 m/min to 6,000 m/min, preferably any value in the range of 2,500 m/min to 5,000 m/min, 3,300 m/min to 4,600 m/min, or 3,000 m/min to 4,500 m/min, such as 1,750 m/min, 2,000 m/min, 2,200 m/min, 2,500 m/min, 3,000 m/min, 3,300 m/min, 3,500 m/min, 4,000 m/min, 4,500 m/min, 4,600 m/min, 5,000 m/min, 5,500 m/min, or 6,000 m/min.

The oiling is performed using an oiling roller with a speed of any value in the range of 400 m/min to 1,600 m/min, such as 400 m/min, 500 m/min, 600 m/min, 700 m/min, 800 m/min, 900 m/min, 1,000 m/min, 1,100 m/min, 1,200 m/min, 1,300 m/min, 1,400 m/min, 1,500 m/min, or 1,600 m/min, etc.

Annular air-blowing is applied between the oiling roller used during the oiling and the first godet roller with the temperature of any value in the range of 15° C. to 45° C., preferably any value in the range of 18° C. to 45° C., such as 15° C., 18° C., 20° C., 25° C., 30° C., 35° C., 40° C., or 45° C.

Annular air-blowing is applied between the second godet roller and the third godet roller with the temperature of any value in the range of 15° C. to 45° C., preferably any value in the range of 18° C. to 45° C., such as 15° C., 18° C., 20° C., 25° C., 30° C., 35° C., 40° C., or 45° C.

Collecting the filament comprises winding the filament onto a bobbin with a winding speed preferably set to any value in the range of 1,750 m/min to 6,000 m/min, further preferably any value in the range of 2,500 m/min to 5,000 m/min, 3,300 m/min to 4,600 m/min, or 3,000 m/min to 4,500 m/min, such as 1,750 m/min, 2,000 m/min, 2,500 m/min, 2,750 m/min, 3,000 m/min, 3,300 m/min, 3,300 m/min, 3,400 m/min, 3,500 m/min, 3,600 m/min, 3,700 m/min, 3,800 m/min, 3,900 m/min, 4,000 m/min, 4,100 m/min, 4,200 m/min, 4,300 m/min, 4,400 m/min, 4,500 m/min, 4,600 m/min, 5,000 m/min, 5,500 m/min, or 6,000 m/min.

In one specific embodiment of the present disclosure, the preparation method comprises:

• • A) subjecting raw materials to drying, mixing, melt-extruding, and cooling and granulating via air-cooling to obtain filament-specific granules;
  • B) subjecting the filament-specific granules to a primary spinning process to obtain a nascent fiber, wherein the primary spinning process comprises simultaneous water-cooling and stretching, wherein the water-cooling temperature is in the range of 0° C. to 30° C., the stretching ratio is in the range of 2 to 12, and an antistatic agent is added to the water; the temperature of the primary spinning process is in the range of 150° C. to 210° C., the pressure is in the range of 5 MPa to 15 MPa, and the extrusion speed is in the range of 40 m/min to 200 m/min;
  • C) drying the nascent fiber in an annular air-blowing duct and oiling the nascent fiber via an oiling roller, wherein an air supply temperature is in the range of 35° C. to 105° C., and the speed at the oiling roller is in the range of 400 m/min to 1,600 m/min; and
  • D) subjecting the oiled strand to a forming process comprising sequentially feeding the oiled strand through a first godet roller, a second godet roller, and a third godet roller, and subsequently collecting the filament,
  • wherein the first godet roller is set at a temperature in the range of 25° C. to 90° C. and a speed in the range of 500 m/min to 2,000 m/min, the second godet roller is set at a temperature in the range of 70° C. to 115° C. and a speed in the range of 1,500 m/min to 5,500 m/min, and the third godet roller is set at a speed in the range of 1,750 m/min to 6,000 m/min; and
  • annular air-blowing is applied between the oiling roller and the first godet roller at a temperature in the range of 15° C. to 45° C., and annular air-blowing is applied between the second godet roller and the third godet roller at a temperature in the range of 15° C. to 45° C.

If the first godet roller and second godet roller are removed, and the annular air-blowing between the oiling roller and the first godet roller, as well as between the second godet roller and the third godet roller, is removed, the winding speed is controlled in the range of 800 m/min to 3,200 m/min to obtain a filament product in the form of POY. The filament in the form of POY may further undergo false-twist texturing to obtain a filament product in the form of DTY.

Preferably, the form of the filament includes, but is not limited to, POY, FDY, and DTY.

In one specific embodiment of the present disclosure, the filament in the form of POY may further undergo false-twist texturing to obtain a filament product in the form of DTY.

In one specific embodiment of the present disclosure, the filament is in the form of FDY; preferably, the annular air-blowing is applied between the oiling roller and the first godet roller;

• • preferably, the annular air-blowing is applied between the oiling roller and the first godet roller with the temperature controlled to any value in the range of 15° C. to 45° C., preferably any value in the range of 18° C. to 45° C., such as 15° C., 18° C., 20° C., 25° C., 30° C., 35° C., 40° C., or 45° C.;
  • preferably, the annular air-blowing is applied between the second godet roller and the third godet roller with the temperature controlled to any value in the range of 15° C. to 45° C., preferably any value in the range of 18° C. to 45° C., such as 15° C., 18° C., 20° C., 25° C., 30° C., 35° C., 40° C., or 45° C.;
  • preferably, the winding speed is any value in the range of 1,750 m/min to 6,000 m/min, further preferably in the range of 2,500 m/min to 5,000 m/min, 3,300 m/min to 4,600 m/min, or 3,000 m/min to 4,500 m/min, such as 1,750 m/min, 2,000 m/min, 2,500 m/min, 3,000 m/min, 3,300 m/min, 3,300 m/min, 3,400 m/min, 3,500 m/min, 3,600 m/min, 3,700 m/min, 3,800 m/min, 3,900 m/min, 4,000 m/min, 4,100 m/min, 4,200 m/min, 4,300 m/min, 4,400 m/min, 4,500 m/min, 4,600 m/min, 5,000 m/min, 5,500 m/min, or 6,000 m/min.

In one specific embodiment of the present disclosure, the filament is in the form of POY; preferably, the winding speed is any value in the range of 800 m/min to 3,200 m/min, further preferably any value in the range of 2,000 m/min to 3,000 m/min, such as 800 m/min, 900 m/min, 1,000 m/min, 1,500 m/min, 1,750 m/min, 2,000 m/min, 2,500 m/min, 3,000 m/min, or 3,200 m/min.

In one specific embodiment of the present disclosure, the filament is in the form of DTY; preferably, the preparation method further comprises false-twist texturing.

In a fourth aspect, provided is the filament or the filament-specific material obtained by the preparation method described above.

In a fifth aspect, provided is a product, which comprises the filament described above or the filament or the filament-specific material obtained by the preparation method described above, or is prepared from the filament or the filament-specific material described above.

In a sixth aspect, provided is use of the filament described above or the filament or the filament-specific material obtained by the preparation method described above in the manufacture of a product requiring a material to exhibit a biodegradable property.

Preferably, the product includes, but is not limited to, a conventional textile product or an industrial textile product.

Preferably, the conventional textile product includes, but is not limited to, a yarn, a thread, a sewing thread, an embroidery thread, a knitted fabric, a woven fabric, a non-woven fabric, a garment, a garment accessory, a household textile, a decorative fabric product, a glove, a hat, a sock, a bag, a blanket, a fabric toy, a lighting decoration, a handicraft, a hand-crocheted article, a kesi silk, a belt, a rope, a woven tape, a hook-and-loop fastener, a fabric packaging product, and the like.

Preferably, the industrial textile product includes, but is not limited to, a wig, a hairpiece, a false eyelash, a false beard, a hair material for doll-making, a vehicle interior trim, an aerospace interior trim, a life-saving equipment, a geotextile, a construction textile, an agricultural textile, a canvas textile product, an artificial leather fabric, a surgical suture, a ligature thread, a fixation thread, a healthcare fabric, a gauze, a bandage, a medical adhesive tape, a cotton swab, a cotton ball, a wound dressing, a protective mask, an adhesive bandage, a surgical supply (including a surgical gown, a surgical cap, and a surgical drape), a glove, a medical protective clothing, a military textile product, and the like.

The term “simultaneous A and B” as described in the present disclosure refers to processes A and B overlapping in time either fully or partially, e.g., “simultaneous cooling and stretching”. For example, “simultaneous water-cooling and stretching” means that the water-cooling process and the stretching process are performed simultaneously. The term “simultaneous” herein means that the duration of the water-cooling process overlaps with the duration of the stretching process either fully or partially, and does not necessarily require identical start times, and/or identical end times, and/or complete temporal coincidence of the two processes. Furthermore, the total duration of water-cooling may differ from the total duration of stretching. The water-cooling duration may be longer than the stretching duration; the stretching duration may be longer than the water-cooling duration; or the durations may be equal. However, it is required that at least 50% (e.g., 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, 99.1%, 99.5%, 99.9%, or 100%) of the shorter duration between the water-cooling duration and the stretching duration must fully overlap with the longer duration.

The term physical modification as described in the present disclosure refers to blending PHA with an auxiliary agent such as a heat stabilizer, a nucleating agent, an antioxidant, a hydrolysis-resistant agent, a reinforcing agent, an anti-blocking agent, an environment-friendly coupling agent, or an environment-friendly plasticizer to enhance or modify its corresponding properties, during which physical changes occur.

The term chemical modification as described in the present disclosure refers to increasing the molecular weight via a chain extender or transforming linear polymer chains into a network structure (branched linkages forming a three-dimensional macromolecular crosslinking structure) using environment-friendly crosslinking agents, during which chemical changes occur.

By providing the embodiments described above, the present disclosure possesses the following advantages:

1. The filament of the present disclosure uses PHA as the primary degradable material without blending with additional materials (e.g., PLA, PBS, and PBAT), thereby improving the quality and process stability of the degradable filament while ensuring faster degradation rates and enhanced environmental compatibility.

2. The primary component of the filament of the present disclosure is degradable, with PHA constituting the largest proportion. Since PHA is 100% degradable, the filament exhibits relatively low environmental requirements for degradation and achieves significantly accelerated degradation rates. The filament completely decomposes in natural environments without requiring composting, offering an eco-friendly and sustainable solution.

3. The filament of the present disclosure demonstrates skin-friendly properties and excellent biocompatibility. Whether applied to intimate textiles or medical products (e.g., personal protective equipment), it provides a soft and comfortable user experience, free from pruritus, allergic reactions, static electricity, or stuffiness. Compared with conventional synthetic fiber fabrics, it exhibits significantly improved safety, wearing comfort, and wearability.

4. In the filament of the present disclosure, the addition of nanomaterials not only acts as a nucleating agent to accelerate the crystallization rate of PHA but also enhances the antibacterial properties of the final filament product. This is attributed to the nanoscale particles interacting with bacterial surfaces, causing damage to the bacterial surfaces. Specifically, nanoparticles generate ROSs (e.g., hydrogen peroxide, hydroxyl radicals, superoxide anions, and hydroperoxides) within bacterial cells, which can induce a series of biological reactions, such as cell membrane damage, leading to lysis or promoting the aggregation of nanoparticles within the bacterial cells. Experiments through formulation adjustments have confirmed that, although PHA itself possesses inherent antibacterial properties, the presence of nano-magnesia, nanocellulose, and fumed nano-silica in the formulation of PHA filament-specific granules can enhance the antibacterial effect. In addition, the addition of nanomaterials also provides a certain flame-retardant effect. When used in combination with tetrachlorophthalic anhydride, it unexpectedly achieves good flame-retardant properties at low addition levels, surpassing the effects of higher individual addition amounts. This demonstrates a synergistic enhancement effect.

5. In the preparation method for the filament of the present disclosure, due to the effects of appropriately selected types and ratios of nucleating agents, chain extenders, environment-friendly crosslinking agents, and environment-friendly coupling agents in the formulation, the melt strength and crystallization rate of PHA are significantly improved. As a result, the entire filament preparation process eliminates the need for prolonged crystallization steps, and the final filament product is achieved through a one-step process. The process line operates with high efficiency and continuity, and the spinning speed is comparable to that of polyester and nylon, thereby reducing processing costs and improving production efficiency.

6. The preparation method for the filament of the present disclosure innovatively employs an FDY processing technology that involves initial cooling and rapid stretching, followed by hot-air drying, rapid crystallization, further stretching and orientation, heat setting, rapid cooling, and winding. Compared with the conventional FDY processing technology, this method exhibits superior processing stability, higher final stretching and orientation, and higher crystallinity. Specifically, experimental results demonstrate that only the initial cooling combined with simultaneous stretching establishes an optimized foundation for subsequent orientation and crystallization. After this step, the toughness of the strand is improved, significantly reducing the probability of subsequent breakage. Furthermore, the increased stretching ratio and elevated spinning speed significantly accelerate the production efficiency of pure PHA filaments.

7. The preparation method for the filament of the present disclosure innovatively incorporates an antistatic agent during the water-cooling process, which is combined with rapid hot-air drying. In one aspect, this combined process synergizes with subsequent oiling agents to ameliorate the electrostatic effects on the filament surface, thereby facilitating filament aggregation and bundling; in another aspect, this combined process synergizes with anti-blocking agents to enhance the wettability of the filament surface, rendering it relatively more hydrophilic and moisture-retentive while significantly reducing adhesion phenomena, which is advantageous for downstream processing and applications.

8. The preparation method for the filament of the present disclosure first employs water-cooling and rapid stretching, whereby PHA extrudate strands are immediately elongated and thinned. Performing this process in water rather than air reduces breakage incidence, partly due to the buoyancy partially counteracting the gravitational force, and partly because the presence of water helps maintain the rubbery state of the PHA material, making it more deformable and thus easier to stretch and thin out. Next, hot-air drying is used to rapidly remove the moisture from the surface of the PHA nascent fibers. The combined effect of the antistatic agent and the anti-blocking agent in the fiber ensures that the fiber surface becomes immediately dry and non-adhesive. Subsequent oiling with the oiling roller further enhances the antistatic effect, facilitating subsequent operations such as aggregation, bundling, stretching, and winding. Subsequently, rapid crystallization is achieved by air-cooling in the fastest crystallization temperature range of no less than the glass transition temperature and no more than the melting point. This rapidly increases the crystallinity of the fiber, thereby enhancing its mechanical strength. Next, high-speed stretching and orientation are performed at the mild temperature at the first godet roller, which makes the molecular orientation more complete, resulting in fibers with high orientation and moderate crystallinity. Afterward, the fibers undergo tension heat setting at the second godet roller, which further develops and perfects the crystallization, making the molecular arrangement more regular and reinforcing the orientation effect. This process releases all the accumulated energy stored within the fibers, achieving stress relaxation. Finally, rapid cooling is used to enhance crystallization while avoiding surface adhesion, allowing the fibers to be smoothly wound onto the bobbin. The entire filament preparation process is continuous, rapid, and efficient, with energy savings.

The term “comprises”, “comprising” or “includes” as described in the present disclosure is an open-ended description that includes the specified ingredients or steps as described, as well as other specified ingredients or steps that do not substantially affect the technical effect.

The correspondence between the English abbreviations and their full Chinese names of the present disclosure is shown in Table 1.

TABLE 1
Correspondence between English abbreviations
and full Chinese names

Abbreviations	Full Chinese names
PHA	Polyhydroxyalkanoate
PHB	Poly-3-hydroxybutyrate
P4HB	Poly-4-hydroxybutyrate
P3HP	Poly-3-hydroxypropionate
PHBV	Copolymer of 3-hydroxybutyric acid and 3-
	hydroxyvaleric acid
PHBHHx	Copolymer of 3-hydroxybutyric acid and 3-
	hydroxyhexanoic acid
P3HB4HB	Copolymer of 3-hydroxybutyric acid and 4-
	hydroxybutyric acid
P3HB4HB3HV	Copolymer of 3-hydroxybutyric acid, 4-
	hydroxybutyric acid, and 3-hydroxyvaleric acid
P3HB4HB5HV	Copolymer of 3-hydroxybutyric acid, 4-
	hydroxybutyric acid, and 5-hydroxyvaleric acid
PBAT	Poly (butyleneadipate-co-terephthalate)
PBS	Polybutylene succinate
PLA	Polylactic acid
PPC	Polypropylene carbonate
POY	Pre-oriented yarn
FDY	Fully drawn yarn
DTY	False-twist textured yarn
Antioxidant CA	1,1,3-Tris(2-methyl-4-hydroxy-5-tert-
	butylphenyl)butane
LOWINOX 44B25	4,4′-Butylidenebis(2-tert-butyl-5-methylphenol)
Anti-hydrolysis	2,2′,6,6′-Tetraisopropyldiphenylcarbodiimide
stabilizer 3600
HTDI	Methylcyclohexyl diisocyanate
DAP	Diallyl phthalate
TTS	Isopropyl triisostearoyltitanate
KR-38S	Isopropyl tri(dioctylpyrophosphato)titanate
TBC	Tributyl citrate
ATBC	Acetyl tributyl citrate
BNTXIB	2,2,4-Trimethyl-1,3-pentanediol diisobutyrate

DETAILED DESCRIPTION

The technical schemes in the examples of the present disclosure will be described clearly and completely below, and it is apparent that the examples described herein are only some examples of the present disclosure, but not all of them. Based on the examples of the present disclosure, all other examples obtained by those of ordinary skill in the art without intensive steps shall fall within the protection scope of the present disclosure.

Unless otherwise specified, all materials used in the examples of the present disclosure are commercially available.

Unless otherwise specified, the parts, percentages, or ratios described in the examples of the present disclosure are on weight basis.

Test Items and Test Methods in Examples:

(1) Specification: Linear density (dtex) was tested according to GB/T 14343-2008 Testing Method for Linear Density of Man-Made Filament Yarns; the number of filaments (f) corresponds to the number of spinneret holes.

(2) Breaking strength (cN/dtex), breaking strength CV (%), breaking elongation (%), and breaking elongation CV (%) were tested according to GB/T 14344-2008 Testing Method for Tensile of Man-Made Filament Yarns.

The retention rate of breaking strength was measured after 3 months of storage. A high retention rate indicates that the post-crystallization phenomenon has been ameliorated.

(3) Limiting oxygen index (%) was tested according to FZ/T 50017-2011 Testing Method for Flame Retardant Property of Polyester Fibers: Oxygen Index.

(4) Antibacterial rate (%) was tested according to GB/T 20944.3-2008 Textiles-Evaluation for Antibacterial Activity—Part 3: Shake Flask Method. The antibacterial rates against Staphylococcus aureus and Escherichia coli were determined.

(5) Skin-friendliness was evaluated via a subjective assessment method. For masks fabricated from the filament, two groups of subjects were selected.

One group consisted of 10 experts or experienced subjects, with a weighting factor of 1. These evaluators are familiar with subjective evaluation scales and the meanings of the descriptions, understand the human sensory responses corresponding to each rating level, and can rapidly and accurately assess and quantify the performance of the filaments.

The other group consisted of 10 consumers with basic training, with a weighting factor of 0.5. Before the experiment, these subjects received explanations regarding the knowledge related to the filament performance and the terminology of the evaluation scale to ensure accurate evaluation of the filament performance and rigorous results.

Experimental conditions: temperature 20° C.±2° C., relative humidity 65%±2%, and air speed ≤0.1 m/s.

Skin-friendliness subjective evaluation scale and descriptors are shown in Table 2:

• • When grade ≤3, rated as poor skin-friendliness;
  • When 3<grade ≤4, rated as average skin-friendliness;
  • When 4<grade ≤4.5, rated as good skin-friendliness;
  • When 4.5<grade ≤5, rated as excellent skin-friendliness.

TABLE 2
Skin-friendliness subjective evaluation scale

Grade	1	2	3	4	5
Description	Allergic	Allergic	Allergic	Mild pruritus is	Softness and no
	reactions,	reactions,	reactions,	experienced	uncomfortable
	burning	burning	burning	only in dry	feeling are
	sensations, or	sensations, or	sensations, or	environments	experienced in
	pruritus are	pruritus are	pruritus are		any
	experienced for	experienced for	experienced for		environments
	no less than	⅕ to ⅓ of	1/10 to ⅕ of
	⅓ of the	the wearing	the wearing
	wearing time	time	time

Example 1: Preparation of PHB+P3HB4HB Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 3.

Example 2: Preparation of PHB+PHBV Filament (Containing Two Basic Auxiliary Agents: Nucleating Agents and Reinforcing Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 55 parts of PHB, 45 parts of PHBV, 0.25 parts of nano-magnesia, 0.2 parts of MILLAD 3988, 0.3 parts of NA-21, 1 part of talc, 1 part of nanocellulose, 1 part of DH-3 reinforcing agent, and 2 parts of tetrachlorophthalic anhydride were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 3.

Example 3: Preparation of PHB+PHBHHx+P3HB4HB Filament (Containing Heat Stabilizers, Nucleating Agents, Chain Extenders, and Reinforcing Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 65 parts of PHB, 20 parts of PHBHHx, 15 parts of P3HB4HB, 0.75 parts of zinc 2-ethylhexanoate, 0.5 parts of calcium stearate, 0.2 parts of nano-calcium carbonate, 0.3 parts of MILLAD 3905, 0.25 parts of NA-21, 0.4 parts of BASF ADR 4400, 0.5 parts of Vertellus E60P, 0.35 parts of trimethylolpropane, 1.5 parts of nanocellulose, 2 parts of DH-4 reinforcing agent, and 1.5 parts of tetrachlorophthalic anhydride were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 3.

Example 4: Preparation of PHB+PHBV+P3HB4HB Filament (Containing Nucleating Agents, Antioxidants, Hydrolysis-Resistant Agents, and Reinforcing Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 65 parts of PHB, 15 parts of PHBV, 20 parts of P3HB4HB, 0.25 parts of nano-calcium carbonate, 0.25 parts of MILLAD 3988, 0.25 parts of ACLYN 285A, 0.25 parts of LOWINOX 44B25, 0.2 parts of antioxidant RIANOX 1790, 0.3 parts of antioxidant RIANOX 168, 0.45 parts of double bond hydrolysis-resistant agent CHINOX P-500, 0.3 parts of KANEKA M732, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, and 2 parts of tetrachlorophthalic anhydride were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 3.

Example 5: Preparation of PHB+PHBHHx+PHBV Filament (Containing Nucleating Agents, Reinforcing Agents, Anti-Blocking Agents, and Environment-Friendly Plasticizers)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 65 parts of PHB, 22 parts of PHBHHx, 13 parts of PHBV, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 3.

Example 6: Preparation of PHB+PHBHHx+PHBV+P3HB4HB Filament (Containing Nucleating Agents, Reinforcing Agents, Environment-Friendly Crosslinking Agents, and Environment-Friendly Coupling Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 55 parts of PHB, 18 parts of PHBHHx, 10 parts of PHBV, 17 parts of P3HB4HB, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, and 0.9 parts of silane coupling agent KH-550 were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 4.

Example 7: Preparation of PHB+P3HB4HB3HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 80 parts of PHB, 20 parts of P3HB4HB3HV, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 4.

Example 8: Preparation of PHB+P3HB4HB5HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 82 parts of PHB, 18 parts of P3HB4HB5HV, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of calcium laurate, 0.25 parts of nano-magnesia, 0.2 parts of MILLAD 3988, 0.3 parts of NA-21, 0.5 parts of BASF ADR 4300F, 0.35 parts of 1,3-bis(4,5-dihydrooxazol-2-yl)benzene, 0.4 parts of trimethylolpropane, 0.25 parts of antioxidant CA, 0.2 parts of antioxidant RIANOX 1790, 0.3 parts of antioxidant RIANOX 168, 0.35 parts of double bond hydrolysis-resistant agent CHINOX P-500, 0.4 parts of DuPont 132F NC010, 1 part of talc, 1 part of nanocellulose, 1 part of DH-3 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.4 parts of silica opening agent AB-MB-09, 0.2 parts of antistatic agent MOA3-PK, 0.3 parts of hydroxypropyl methacrylate, 0.5 parts of HTDI, 0.45 parts of multifunctional aziridine crosslinking agent SaC-100, 0.7 parts of silane coupling agent KH-550, 0.8 parts of silane coupling agent KBM-602, 0.5 parts of TBC, and 0.5 parts of BNTXIB were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 4.

Example 9: Preparation of PHB+P3HB4HB3HV+P3HB4HB5HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 81 parts of PHB, 10 parts of P3HB4HB3HV, 9 parts of P3HB4HB5HV, 0.75 parts of zinc 2-ethylhexanoate, 0.5 parts of calcium stearate, 0.2 parts of nano-calcium carbonate, 0.3 parts of MILLAD 3905, 0.25 parts of NA-21, 0.4 parts of BASF ADR 4400, 0.5 parts of Vertellus E60P, 0.35 parts of trimethylolpropane, 0.25 parts of LOWINOX 44B25, 0.2 parts of antioxidant RIANOX 1098, 0.3 parts of antioxidant RIANOX 626, 0.35 parts of polycarbodiimide UN-03, 0.4 parts of DuPont 132F NC010, 1.5 parts of nanocellulose, 2 parts of DH-4 reinforcing agent, 1.5 parts of tetrachlorophthalic anhydride, 0.35 parts of stearamide, 0.35 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of HTDI, 0.35 parts of DAP, 0.5 parts of multifunctional polycarbodiimide UN-557, 0.65 parts of silane coupling agent KH-550, 0.85 parts of TTS, 0.4 parts of ATBC, and 0.6 parts of BNTXIB were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 4.

Example 10: Preparation of PHB+PHBV+P3HB4HB3HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 70 parts of PHB, 12 parts of PHBV, 18 parts of P3HB4HB3HV, 0.6 parts of zinc 2-ethylhexanoate, 0.65 parts of magnesium laurate, 0.25 parts of nano-calcium carbonate, 0.25 parts of MILLAD 3988, 0.25 parts of ACLYN 285A, 0.55 parts of BASF ADR 4400, 0.3 parts of 1,3-bis(4,5-dihydrooxazol-2-yl)benzene, 0.4 parts of EK-145 polyester chain extender, 0.25 parts of LOWINOX 44B25, 0.2 parts of antioxidant RIANOX 1790, 0.3 parts of antioxidant RIANOX 168, 0.45 parts of double bond hydrolysis-resistant agent CHINOX P-500, 0.3 parts of KANEKA M732, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of stearamide, 0.25 parts of silica opening agent AB-MB-09, 0.35 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.4 parts of HTDI, 0.45 parts of N-(isobutoxymethyl)acrylamide, 0.75 parts of silane coupling agent Z-6020, 0.75 parts of KR-38S, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 4.

Example 11: Preparation of PHB+PHBV+P3HB4HB5HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 70 parts of PHB, 14 parts of PHBV, 16 parts of P3HB4HB5HV, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 5.

Example 12: Preparation of PHB+PHBHHx+P3HB4HB3HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 72 parts of PHB, 14 parts of PHBHHx, 14 parts of P3HB4HB3HV, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 5.

Example 13: Preparation of PHB+PHBHHx+P3HB4HB5HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 72 parts of PHB, 16 parts of PHBHHx, 12 parts of P3HB4HB5HV, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 5.

Example 14: Preparation of PHB+P3HB4HB+P3HB4HB3HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 12 parts of P3HB4HB, 13 parts of P3HB4HB5HV, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 5.

Example 15: Preparation of PHB+P3HB4HB+P3HB4HB5HV Filament (Containing Various Auxiliary Agents)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 15 parts of P3HB4HB, 10 parts of P3HB4HB5HV, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 5.

Example 16: Preparation of PHB+P3HB4HB Filament Free of Tetrachlorophthalic Anhydride (Free of Tetrachlorophthalic Anhydride Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 5.

Example 17

The process was identical to that described in Example 1, except that the amounts of the auxiliary agents added were adjusted as follows: 1 part of magnesium 2-ethylhexanoate, 1.5 parts of zinc stearate, 0.0001 parts of nano-magnesia, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC.

Example 18

The process was identical to that described in Example 1, except that the amounts of the auxiliary agents added were adjusted as follows: 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.5 parts of nano-magnesia, 0.5 parts of MILLAD 3905, 0.5 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 0.1 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC.

Example 19

The process was identical to that described in Example 1, except that the amounts of the auxiliary agents added were adjusted as follows: 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 1 part of BASF ADR 4300F, 0.5 parts of Vertellus E60P, 1 part of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.8 parts of oleamide, 0.6 parts of BYK3700 organosilicon leveling agent, 0.6 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC.

Example 20

The process was identical to that described in Example 1, except that the amounts of the auxiliary agents added were adjusted as follows: 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.5 parts of antioxidant CA, 0.5 parts of antioxidant RIANOX1098, 0.5 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.8 parts of methyltriethoxysilane, 1 part of HTDI, 0.7 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC.

Example 21

The process was identical to that described in Example 1, except that the amounts of the auxiliary agents added were adjusted as follows: 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 1 part of polycarbodiimide UN-03, 0.5 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 1.2 parts of silane coupling agent Z-6020, 1.8 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC.

Example 22

The process was identical to that described in Example 1, except that the amounts of the auxiliary agents added were adjusted as follows: 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 3 parts of fumed nano-silica, 3 parts of DH-2 reinforcing agent, 4 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.8 parts of TBC, and 1.2 parts of ATBC.

Example 23: Preparation of PHB+P3HB4HB Filament

The raw materials and the ratio were identical to those described in Example 1, except that:

Step I: The raw materials were vacuum-dried at a temperature in the range of 60° C. to 80° C. for a duration in the range of 10 h to 12 h to control the moisture content to no more than 180 ppm.

Step II: The raw materials were physically mixed using a high-speed mixer for a duration in the range of 30 min to 60 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 220° C., and the air supply temperature was in the range of 5° C. to 65° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules obtained in Step II were vacuum-dried at a temperature of 60° C. for 4 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 210° C., the pressure in the melt metering pump was controlled in the range of 5 MPa to 13 MPa, and the spinneret had 24 holes. The extrusion speed was controlled in the range of 100 m/min to 200 m/min. The extrudate was cooled in a horizontal water tank with a length of 0.5 m and simultaneously stretched with a stretching ratio in the range of 2 to 8. The water temperature was 0° C., and 0.3% Tween 60 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 10 m. The air supply temperature was in the range of 35° C. to 85° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 400 m/min to 800 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 90° C. and the spinning speed controlled in the range of 600 m/min to 1,200 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 115° C. and the stretching speed controlled in the range of 2,400 m/min to 4,500 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2.5 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 2,700 m/min to 5,000 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

Example 24: Preparation of PHB+P3HB4HB Filament

The raw materials and the ratio were identical to those described in Example 1, except that:

Step I: The raw materials were vacuum-dried at a temperature in the range of 85° C. to 105° C. for a duration in the range of 6 h to 8 h to control the moisture content to no more than 180 ppm.

Step II: The raw materials were physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 140° C. to 210° C., and the air supply temperature was in the range of 35° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature of 105° C. for 1 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 150° C. to 205° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 15 MPa, and the spinneret had 72 holes. The extrusion speed was controlled in the range of 40 m/min to 120 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 12. The water temperature was 15° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 2.5 m. The air supply temperature was in the range of 90° C. to 105° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 480 m/min to 1,440 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 25° C. to 70° C. and the spinning speed controlled in the range of 500 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 70° C. to 110° C. and the stretching speed controlled in the range of 1,500 m/min to 2,250 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 1.5 to 3. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 1,750 m/min to 2,750 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

Example 25: Preparation of PHB+P3HB4HB Filament

The raw materials and the ratio were identical to those described in Example 1, except that:

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: The raw materials were physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 12 holes. The extrusion speed was controlled in the range of 120 m/min to 200 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 12. The water temperature was 4° C., and 0.25% Tween 60 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,600 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 90° C. and the spinning speed controlled in the range of 1,500 m/min to 2,000 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,200 m/min to 5,500 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 3. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,500 m/min to 6,000 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

Example 26: Preparation of PHB+P3HB4HB Filament

The raw materials and the ratio were identical to those described in Example 1, except that:

Step I: The raw materials were vacuum-dried at a temperature of 85° C. for 8 h to control the moisture content to no more than 180 ppm.

Step II: The raw materials were physically mixed using a high-speed mixer for a duration of 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature of 100° C. for 1.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 160° C. to 200° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 96 holes. The extrusion speed was controlled in the range of 60 m/min to 120 m/min. The extrudate was cooled in a horizontal water tank with a length of 5 m and simultaneously stretched with a stretching ratio in the range of 4 to 10. The water temperature was 30° C., and 0.05% Tween 20 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 4 m. The air supply temperature was in the range of 85° C. to 100° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 480 m/min to 1,200 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 600 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 1,600 m/min to 4,000 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 1,800 m/min to 4,500 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

The FDY filament products obtained in Examples 17 to 26 above meet the performance requirements for subsequent applications.

Comparative Example 1: Preparation of PHB+PBS Filament (P3HB4HB Replaced with PBS Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of PBS, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final filament product in the form of FDY was obtained.

The filament product obtained in Comparative Example 1 exhibited yellowing, which may be attributed to the relatively high processing temperature compared with that for PBS, leading to oxidative degradation and post-crystallization phenomena. Therefore, the filament product obtained in Comparative Example 1 showed inferior performance in terms of the breaking strength, the retention rate of breaking strength, the breaking strength CV, the breaking elongation CV, the antibacterial rate, and the skin-friendliness compared with that obtained in Example 1, as can be seen from Tables 3 and 6.

Comparative Example 2: Preparation of PHB+P3HB4HB Filament Free of Nanoparticles (Free of Nano-Magnesia and Fumed Nano-Silica Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

The filament product obtained in Comparative Example 2 exhibited deteriorated thermal stability, slower crystallization rates, and unstable processing characteristics due to the absence of nanoparticles. This led to roller adhesion issues during processing. Additionally, the spinning temperature had to be maintained within the low-temperature range; otherwise, thermal degradation would occur above 180° C. Therefore, the filament product obtained in Comparative Example 2 showed inferior performance in terms of the breaking strength, the retention rate of breaking strength, the breaking strength CV, the breaking elongation CV, the limiting oxygen index, and the antibacterial rate compared with that obtained in Example 1, as can be seen from Tables 3 and 6.

Comparative Example 3: Preparation of PHB+P3HB4HB Filament Free of Nanomaterials and Tetrachlorophthalic Anhydride (Free of Nano-Magnesia, Fumed Nano-Silica, and Tetrachlorophthalic Anhydride Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of DH-2 reinforcing agent, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

The filament product obtained in Comparative Example 3 exhibited deteriorated thermal stability, slower crystallization rates, and unstable processing characteristics due to the absence of nanoparticles and tetrachlorophthalic anhydride. This led to roller adhesion issues during processing. Additionally, the spinning temperature had to be maintained within the low-temperature range; otherwise, thermal degradation would occur above 180° C. Therefore, the filament product obtained in Comparative Example 3 showed inferior performance in terms of the breaking strength, the retention rate of breaking strength, the breaking strength CV, the breaking elongation CV, the limiting oxygen index, and the antibacterial rate compared with that obtained in Example 1, as can be seen from Tables 3 and 6.

Combined analysis of Comparative Examples 2 and 3 and Examples 1 and 16 reveals the synergistic effects of nanoparticles (nano-magnesia and fumed nano-silica) and tetrachlorophthalic anhydride on mechanical properties and flame-retardant properties.

Comparative Example 4: Preparation of PHB+P3HB4HB Filament Free of Nucleating Agents (Free of Nucleating Agents Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

The filament product obtained in Comparative Example 4 exhibited deteriorated thermal stability, slower crystallization rates, and unstable processing characteristics due to the absence of nucleating agents. This led to roller adhesion issues during processing. Additionally, the spinning temperature had to be maintained within the low-temperature range; otherwise, thermal degradation would occur above 180° C. Therefore, the filament product obtained in Comparative Example 4 showed inferior performance in terms of the breaking strength, the retention rate of breaking strength, the breaking strength CV, the breaking elongation CV, the limiting oxygen index, and the antibacterial rate compared with that obtained in Example 1, as can be seen from Tables 3 and 7.

Comparative Example 5: Preparation of PHB+P3HB4HB Filament Free of Nano-Magnesia (Free of Nano-Magnesia Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

The filament product obtained in Comparative Example 5 exhibited deteriorated thermal stability, slower crystallization rates, and unstable processing characteristics due to the absence of nano-magnesia. This led to roller adhesion issues during processing. Additionally, the spinning temperature had to be maintained within the low-temperature range; otherwise, thermal degradation would occur above 185° C. Therefore, the filament product obtained in Comparative Example 5 showed inferior performance in terms of the breaking strength, the retention rate of breaking strength, the breaking strength CV, the breaking elongation CV, the limiting oxygen index, and the antibacterial rate compared with that obtained in Example 1, as can be seen from Tables 3 and 7.

Comparative Example 6: Preparation of PHB+P3HB4HB Filament Free of Fumed Nano-Silica (Free of Fumed Nano-Silica Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.25 parts of MILLAD 3905, 0.5 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

Compared with Example 1, Comparative Examples 2, 5, and 6 demonstrate the synergistic effects of nano-magnesia and other nanoparticles on the antibacterial rate.

The filament product obtained in Comparative Example 6 showed inferior performance in terms of the breaking strength, the retention rate of breaking strength, the breaking strength CV, the breaking elongation CV, and the antibacterial rate compared with that obtained in Example 1, as can be seen from Tables 3 and 7.

Comparative Example 7: Preparation of PHB+P3HB4HB Filament Free of Reinforcing Agents (Free of Reinforcing Agents Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

The filament product obtained in Comparative Example 7 exhibited significantly reduced strength due to the absence of reinforcing agents comprising fumed nano-silica and tetrachlorophthalic anhydride. Compared with Example 1, the breaking strength, the retention rate of breaking strength, the breaking strength CV, the breaking elongation CV, the flame retardancy, and the antibacterial rate were all deteriorated, as can be seen from Tables 3 and 7.

Comparative Example 8: Preparation of PHB+P3HB4HB Filament with Air-Cooling Only (Water-Cooling Replaced with Air-Cooling Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled by a horizontal air-cooling device with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The air-cooling temperature was 4° C. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

However, during the filament preparation process, fiber breakage extremely frequently occurred, and the process was unstable. The final product exhibited significant brittleness. The performance parameters are shown in Table 8.

Comparative Example 9: Preparation of PHB+P3HB4HB Filament with Excessively High Speed (with Excessively High Stretching Speed and Winding Speed Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 6,500 m/min to 8,000 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 5 to 6. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 6,600 m/min to 8,200 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 8.

Comparative Example 10: Preparation of PHB+P3HB4HB Filament with Excessively Low Speed (with Excessively Slow Stretching Speed and Winding Speed Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 1,560 m/min to 2,250 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 1.2 to 1.5. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 1,650 m/min to 2,400 m/min. Thus, the final PHA filament product in the form of FDY was obtained. The performance parameters are shown in Table 8.

Comparative Example 11: Preparation of PHB+P3HB4HB Filament Via Simultaneous Air-Cooling and Stretching Followed by Water-Cooling (Distinct Cooling and Forming Process Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were subsequently stretched with a stretching ratio in the range of 6 to 10. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were cooled in a horizontal water tank with a length of 1 m. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

However, during the filament preparation process, roller adhesion phenomena and fiber breakage frequently occurred, and the process was unstable. The final product exhibited post-crystallization phenomena. The performance parameters are shown in Table 8.

Comparative Example 12: Preparation of PHB+P3HB4HB Filament Via Water-Cooling without Simultaneous Stretching (Distinct Cooling and Forming Process Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 200 m/min to 300 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

However, during the filament preparation process, fiber breakage frequently occurred, and the process was unstable. The final product exhibited post-crystallization phenomena. The performance parameters are shown in Table 9.

Comparative Example 13: Preparation of PHB+P3HB4HB Filament Via Water-Cooling Followed by Air-Cooling and Warm-Water Stretching (Distinct Cooling and Forming Process Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 18° C. to 45° C. The fibers were subsequently cooled in a horizontal water tank with a length of 1 m. The water temperature was in the range of 18° C. to 45° C., and 0.15% Tween 40 was added to the water. Stretching was simultaneously performed. The fibers were oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

However, during the filament preparation process, roller adhesion phenomena and fiber breakage frequently occurred, and the process was unstable. The performance parameters are shown in Table 9.

Comparative Example 14: Preparation of PHB+P3HB4HB Filament with Accelerated Spinning Speed (with Excessively High Spinning Speed Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 2,600 m/min to 3,000 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 1.1 to 1.5. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

However, during the filament preparation process, fiber breakage frequently occurred. The performance parameters are shown in Table 9.

Comparative Example 15: Preparation of PHB+P3HB4HB Filament with Reduced Spinning Speed (with Excessively Slow Spinning Speed Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 3.5 to 7. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 350 m/min to 450 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 360 m/min to 480 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 4 to 7. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

However, during the filament preparation process, fiber breakage frequently occurred, and the final product exhibited post-crystallization phenomena. The performance parameters are shown in Table 9.

Comparative Example 16: Preparation of PHB+P3HB4HB Filament with Excessive Water-Cooling Temperature (with Excessive Water-Cooling Temperature Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 6 to 10. The water temperature was 40° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,200 m/min to 1,400 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,300 m/min to 1,500 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

However, during the filament preparation process, roller adhesion and fiber breakage frequently occurred, and the final product exhibited post-crystallization phenomena, failing to meet downstream application requirements. The performance parameters are shown in Table 9.

Comparative Example 17: Preparation of PHB+P3HB4HB Filament with Excessive Water-Cooling Stretching Ratio (with Excessive Water-Cooling Stretching Ratio Compared with Example 1)

Step I: The raw materials were vacuum-dried at a temperature in the range of 70° C. to 95° C. for a duration in the range of 6 h to 10 h to control the moisture content to no more than 180 ppm.

Step II: 75 parts of PHB, 25 parts of P3HB4HB, 0.5 parts of magnesium 2-ethylhexanoate, 0.75 parts of zinc stearate, 0.25 parts of nano-magnesia, 0.15 parts of MILLAD 3905, 0.35 parts of ACLYN 285A, 0.5 parts of BASF ADR 4300F, 0.25 parts of Vertellus E60P, 0.5 parts of EK-145 polyester chain extender, 0.25 parts of antioxidant CA, 0.25 parts of antioxidant RIANOX 1098, 0.25 parts of antioxidant RIANOX 626, 0.5 parts of polycarbodiimide UN-03, 0.25 parts of anti-hydrolysis stabilizer 3600, 1.5 parts of fumed nano-silica, 1.5 parts of DH-2 reinforcing agent, 2 parts of tetrachlorophthalic anhydride, 0.4 parts of oleamide, 0.3 parts of BYK3700 organosilicon leveling agent, 0.3 parts of antistatic agent MOA3-PK, 0.4 parts of methyltriethoxysilane, 0.5 parts of HTDI, 0.35 parts of aluminum citrate, 0.6 parts of silane coupling agent Z-6020, 0.9 parts of silane coupling agent KH-550, 0.4 parts of TBC, and 0.6 parts of ATBC were weighed in parts by mass, physically mixed using a high-speed mixer for a duration in the range of 10 min to 30 min, subsequently melt-extruded through a twin-screw extruder, and cooled and granulated via air-cooling. The barrel temperature was set to the range of 150° C. to 210° C., and the air supply temperature was in the range of 15° C. to 75° C. Thus, the PHA filament-specific granules were obtained.

Step III: The PHA filament-specific granules were vacuum-dried at a temperature in the range of 70° C. to 105° C. for 2.5 h and subsequently spun using a twin-screw melt-spinning machine. The spinning temperature was set to the range of 165° C. to 195° C., the pressure in the melt metering pump was controlled in the range of 6 MPa to 13 MPa, and the spinneret had 48 holes. The extrusion speed was controlled in the range of 60 m/min to 100 m/min. The extrudate was cooled in a horizontal water tank with a length of 1 m and simultaneously stretched with a stretching ratio in the range of 14 to 18. The water temperature was 4° C., and 0.15% Tween 40 was added to the water. Thus, the PHA nascent fibers were obtained.

Step IV: The cooled PHA nascent fibers obtained in Step III were dried in a vertical annular air-blowing duct with a length of 3.5 m. The air supply temperature was in the range of 85° C. to 102° C. The fibers were immediately oiled via an oiling roller, and multiple fibers were bundled into strands. The speed at the oiling roller was in the range of 1,400 m/min to 1,800 m/min.

Step V: The oiled PHA strands obtained in Step IV were sequentially fed through a first godet roller (with the stretching heating temperature controlled in the range of 45° C. to 70° C. and the spinning speed controlled in the range of 1,600 m/min to 2,100 m/min), a second godet roller (with the heat-setting temperature controlled in the range of 75° C. to 110° C. and the stretching speed controlled in the range of 3,000 m/min to 4,200 m/min), and a third godet roller. Annular air-blowing was applied between the oiling roller and the first godet roller with the temperature controlled in the range of 18° C. to 45° C. Stretching occurred between the first godet roller and the second godet roller with the stretching ratio controlled in the range of 2 to 4. Annular air-blowing was applied between the second godet roller and the third godet roller with the temperature controlled in the range of 18° C. to 45° C. Subsequently, the strands were wound onto a bobbin via a winding device at a winding speed in the range of 3,300 m/min to 4,600 m/min. Thus, the final PHA filament product in the form of FDY was obtained.

Due to the excessive water-cooling stretching ratio, the subsequent oiling roller speed and first godet roller speed were forced to increase to maintain fiber tension, resulting in incoordination between overall stretching and crystallization processes. This led to extremely unstable filament quality and process instability, with a high propensity for fiber breakage. The performance parameters are shown in Table 9.

The test results from the Examples described above are summarized in Tables 3 to 5, whereas those from the Comparative Examples are summarized in Tables 6 to 9. Compared with the filaments prepared in the Examples, the filaments from the Comparative Examples exhibited affected comprehensive performance, whereas the filaments of the present application demonstrated superior technical effects.

TABLE 3
Test results of Examples 1 to 5

Item	Example 1	Example 2	Example 3	Example 4	Example 5
Specification	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f
Breaking strength	3.31 cN/dtex	3.12 cN/dtex	3.26 cN/dtex	3.25 cN/dtex	3.03 cN/dtex
Retention rate of	93.9%	93.1%	93.6%	93.4%	93.5%
breaking strength
Breaking strength CV	4.75%	4.98%	4.88%	4.93%	5.02%
Breaking elongation	36.9%	34.7%	33.9%	34.2%	40.4%
Breaking elongation CV	6.83%	7.05%	6.93%	6.90%	7.11%
Limiting oxygen index	31.3	31.1	31.2	31.2	31.1

Antibacterial	Staphylococcus	98.9	98.6	98.7	98.6	98.6
rate	aureus
	Escherichia	99.2	99.0	99.1	99.1	99.0
	coli

Skin-friendliness

4.67,

4.7,

4.67,

4.7,

4.67,

	excellent	excellent	excellent	excellent	excellent

TABLE 4
Test results of Examples 6 to 10

Item	Example 6	Example 7	Example 8	Example 9	Example 10
Specification	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f
Breaking strength	3.24 cN/dtex	3.28 cN/dtex	3.23 cN/dtex	3.20 cN/dtex	3.25 cN/dtex
Retention rate of	93.5%	93.5%	93.4%	93.6%	93.8%
breaking strength
Breaking strength CV	4.86%	4.79%	4.75%	4.84%	4.77%
Breaking elongation	34.8%	37.0%	36.8%	37.3%	36.5%
Breaking elongation CV	6.98%	6.86%	6.80%	6.92%	6.85%
Limiting oxygen index	31.2	31.3	31.3	31.2	31.4

Antibacterial	Staphylococcus	98.6	98.9	98.8	98.7	98.9
rate	aureus
	Escherichia	99.1	99.0	99.3	99.2	99.3
	coli

Skin-friendliness

4.67,

4.63,

4.6,

4.67,

4.63,

	excellent	excellent	excellent	excellent	excellent

TABLE 5
Test results of Examples 11 to 16

Item	Example 11	Example 12	Example 13	Example 14	Example 15	Example 16
Specification	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f
Breaking strength	3.22 cN/dtex	3.26 cN/dtex	3.21 cN/dtex	3.27 cN/dtex	3.24 cN/dtex	3.01 cN/dtex
Retention rate of	93.7%	93.9%	93.6%	93.8%	93.6%	92.1%
breaking strength
Breaking strength CV	4.79%	4.82%	4.75%	4.78%	4.84%	5.85%
Breaking elongation	36.7%	37.0%	37.2%	36.7%	36.6%	39.3%
Breaking elongation CV	6.86%	6.88%	6.90%	6.87%	6.93%	8.64%
Limiting oxygen index	31.2	31.3	31.3	31.3	31.2	29.3

Antibacterial	Staphylococcus	98.7	99.0	98.9	98.7	99.0	97.2
rate	aureus
	Escherichia	99.1	99.0	99.2	99.0	99.3	97.6
	coli

Skin-friendliness

4.6,

4.67,

4.63,

4.7,

4.67,

4.7,

	excellent	excellent	excellent	excellent	excellent	excellent

TABLE 6
Test results of Comparative Examples 1 to 3

	Comparative	Comparative	Comparative
Item	Example 1	Example 2	Example 3
Specification	167dtex/48f	167dtex/48f	167dtex/48f
Breaking	2.36 cN/dtex	2.90 cN/dtex	2.42 cN/dtex
strength
Retention rate of breaking strength	86.2%	83.4%	79.3%
Breaking strength CV	9.37%	7.82%	7.95%
Breaking	42.4%	37.3%	39.5%
elongation
Breaking	12.85%	9.57%	10.36%
elongation CV
Limiting oxygen index	30.8	29.8	26.4

Antibacterial rate	Staphylococcus aureus	93.2	88.3	87.9
	Escherichia coli	93.6	89.1	88.1

Skin-friendliness	3.53, average	4.67, excellent	4.7, excellent

TABLE 7
Test results of Comparative Examples 4 to 7

	Comparative	Comparative	Comparative	Comparative
Item	Example 4	Example 5	Example 6	Example 7

Specification	167dtex/48f	167dtex/48f	167dtex/48f	167dtex/48f
Breaking	2.93 cN/dtex	3.11 cN/dtex	3.04 cN/dtex	2.06 cN/dtex
strength
Retention rate of breaking strength	67.2%	86.7%	86.9%	81.8%
Breaking strength CV	8.78%	7.33%	6.85%	6.61%
Breaking	40.4%	38.9%	40.7%	41.0%
elongation
Breaking	11.30%	9.03%	8.95%	8.42%
elongation CV
Limiting oxygen index	29.9	30.0	31.0	29.1

Antibacterial	Staphylococcus	96.1	96.5	96.8	96.6
	aureus
rate	Escherichia coli	96.4	96.8	97.2	96.9

Skin-friendliness	4.7, excellent	4.7, excellent	4.67, excellent	4.67, excellent

TABLE 8
Test results of Comparative Examples 8 to 11

	Comparative	Comparative	Comparative	Comparative
Item	Example 8	Example 9	Example 10	Example 11
Specification	167dtex/48f	115dtex/48f	167dtex/48f	167dtex/48f
Breaking	2.68 cN/dtex	2.73 cN/dtex	2.65 cN/dtex	2.85 cN/dtex
strength
Retention rate of breaking	76.2%	88.3%	83.6%	81.4%%
strength
Breaking strength CV	4.96%	8.65%	5.91%	4.87%
Breaking	23.1%	28.7%	42.8%	29.6%
elongation
Breaking	10.87%	10.13%	7.26%	8.53%
elongation CV

TABLE 9
Test results of Comparative Examples 12 to 17

	Comparative	Comparative	Comparative	Comparative	Comparative	Comparative
Item	Example 12	Example 13	Example 14	Example 15	Example 16	Example 17
Specification	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	167 dtex/48 f	140 dtex/48 f
Breaking	2.93 cN/dtex	3.01 cN/dtex	2.74 cN/dtex	2.63 cN/dtex	2.75 cN/dtex	2.62 cN/dtex
strength
Retention	79.8%	85.6%	90.7%	86.0%	83.4%	79.3%
rate of
breaking
strength
Breaking	9.21%	5.45%	7.46%	6.72%	7.53%	9.38%
strength CV
Breaking	32.7%	33.9%	38.2%	35.4%	26.5%	20.7%
elongation
Breaking	7.34%	7.60%	8.19%	8.48%	8.20%	9.51%
elongation CV

It should be noted that the examples described above are provided solely to illustrate the technical solutions of the present disclosure and shall not be construed as limiting. Although the present disclosure has been described in detail with reference to preferred examples, those of ordinary skill in the art will appreciate that modifications or equivalent substitutions to the technical solutions of the present disclosure may be made without departing from the spirit and scope of the technical solutions of the present disclosure. All such modifications and substitutions shall fall within the scope of the claims of the present disclosure.