NONWOVEN SHOE UPPER AND FABRICATING METHOD THEREOF

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to China Patent Application 202411535953.8, filed October 30, 2024, which is incorporated herein by reference.

FIELD OF DISCLOSURE

The present disclosure relates to a nonwoven shoe upper and a fabricating method thereof.

DESCRIPTION OF RELATED ART

Generally, a footwear product comprises a shoe sole and a shoe upper that is fixed to the shoe sole, wherein shoe uppers currently available and made of non-leather materials are mostly formed by braiding or weaving methods. To braid or weave shoe uppers, yarn is woven to form patterns or textures into the jacquard of the shoe uppers. However, patterns and textures of jacquard fabric formed by such a method can have a slightly coarser texture in appearance, and the weaving process can consume significant time, resulting in low production efficiency. Thus, such a weaving/braiding method is constrained in achieving high production efficiency and delicate pattern designs. On the other hand, in order to deliver specified patterns on shoe appearance, constant adjustments of yarn tension, weaving density, and arrangements are needed while fabricating jacquard. In order to form complicated patterns on shoe appearance, changing the yarn to different colors and materials is required. As a result, it is difficult to precisely control the firmness of each piece of yarn, and the texture within the shoe can easily become rough and uneven, which affects wearing comfort. In view of the aforementioned problems of the prior art, how to provide a shoe upper with high comfort in wearing and great aesthetics is one of the goals under active research by people in the industry.

SUMMARY

According to several embodiments of the present disclosure, a nonwoven shoe upper, having an inner surface and an outer surface, comprises a base layer and a surface layer. A surface of the base layer defines the inner surface, and the base layer comprises a plurality of first polymer strips stacked and intersecting with each other, wherein any two of the plurality of first polymer strips used for defining the inner surface that intersect constitute a first joint. The surface layer is disposed on the base layer, and the surface thereof defines the outer surface; and the surface layer comprises a plurality of second polymer strips stacked and intersecting with each other, wherein any two of the plurality of second polymer strips used for defining the outer surface that intersect constitute the second joint. The lower surface of the first joint and the lower surfaces of the first polymer strips that constitute the first joint are substantially planar. A thickness of the second joint is 135% to 200% of a thickness of any one of the two of the plurality of second polymer strips that constitute the second joint.

In several embodiments of the present disclosure, the lower surface of the first joint is higher than the lower surfaces of the two of the plurality of first polymer strips that constitute the first joint by no more than 20% of a thickness of any one of the two of the plurality of first polymer strips that constitute the first joint.

In several embodiments of the present disclosure, each of the plurality of first polymer strips and each of the plurality of second polymer strips has a plurality of porous structures.

According to several embodiments of the present disclosure, the fabricating method of a nonwoven shoe upper, having an inner surface and an outer surface, comprises the following steps: adding a polymer in the solvent to form a dispensing solution; dispensing the dispensing solution to the surface of the substrate to form a plurality of first polymer strips, stacked and intersecting with each other and corresponding to the base layer, and a plurality of second polymer strips, stacked and intersecting with each other and corresponding to the surface layer, wherein evaporation of the solvent in the plurality of first polymer strips and the solvent in the plurality of second polymer strips causes the plurality of first polymer strips and the plurality of second polymer strips gradually solidify; allowing the stacked base layer and the stacked surface layer to stand for a predetermined period of time, thereby solidifying and forming the nonwoven shoe upper, wherein the surface of the base layer defines the inner surface and the surface of the surface layer defines the outer surface; wherein any two of the plurality of first polymer strips used for defining the inner surface that intersect constitute a first joint, any two of the plurality of second polymer strips for defining the outer surface that intersect constitute a second joint, a lower surface of the first joint and lower surfaces of the two of the plurality of first polymer strips that constitute the first joint are substantially planar, and a thickness of the second joint is 135% to 200% of a thickness of any one of the two of the plurality of second polymer strips that constitute the second joint.

In several embodiments of the present disclosure, the polymer has a weight percentage concentration in the solvent of 5% to 90%.

In several embodiments of the present disclosure, the solvent comprises a primary solvent and an auxiliary solvent, and a difference in boiling points between the primary solvent and the auxiliary solvent ranges from 10°C to 150°C.

In several embodiments of the present disclosure, the fabricating method of the nonwoven shoe upper further comprises: adding a foaming agent in the solvent to form the dispensing solution; and performing a foaming step on the nonwoven shoe upper after the nonwoven shoe upper is solidified and formed.

In several embodiments of the present disclosure, the foaming step is performed on the nonwoven shoe upper with at an expansion ratio of 105% to 130%.

In several embodiments of the present disclosure, the dispensing solution is dispensed onto the surface of the substrate based on a pre-compensation value to form the plurality of first polymer strips and the plurality of second polymer strips with a controlled line width.

In several embodiments of the present disclosure, the substrate comprises a planar substrate, a curved flat-surfaced substrate, or a last substrate.

According to the aforementioned embodiments of the present disclosure, through the design of a nonwoven shoe upper of the present disclosure that comprises a substantially planar inner surface and a three-dimensional outer surface, the nonwoven shoe upper can achieve a high degree of wearing comfort and great aesthetics. On the other hand, through the use of dispensing (or, including foaming) methods along with curing methods for adhesive, the present disclosure can fabricate adhesive-formed shoe uppers of special designs. Therefore, problems in making shoe uppers using conventional methods of weaving or braiding yarn into jacquard can be overcome, and a nonwoven shoe upper with a substantially planar inner surface and a three-dimensional outer surface can be produced that makes an adhesive-formed shoe upper have a high degree of wearing comfort, air permeability, and great aesthetics similar to that of jacquard fabric made from weaving yarn.

BRIEF DESCRIPTION OF THE DRAWINGS

To better understand the aforementioned and other objectives, novel features, advantages, and embodiments of the present disclosure, the detailed descriptions of the present disclosure are provided as follows, along with diagrams and preferred embodiments:

FIG. 1 and FIG. 2 are schematic plan views of the nonwoven shoe upper, respectively, according to several embodiments of the present disclosure;

FIG. 3A is a three-dimensional schematic view of the two intersecting first polymer strips located on the inner surface of the nonwoven shoe upper according to several embodiments of the present disclosure;

FIG. 3B is a three-dimensional schematic view of the two intersecting second polymer strips located on the outer surface of the nonwoven shoe upper according to several embodiments of the present disclosure;

FIG. 3C is a cross-sectional view of the second polymer strips along the cutting plane line C-C' of FIG. 3B;

FIG. 4A shows an image of the inner surface of the nonwoven shoe upper generated by an optical microscope according to several embodiments of the present disclosure;

FIG. 4B shows an image of the outer surface of the nonwoven shoe upper generated by an optical microscope according to several embodiments of the present disclosure;

FIG. 5 is a schematic cross-sectional micro-scale view of the first polymer strips or the second polymer strips according to several embodiments of the present disclosure;

FIG. 6 is a flow chart of the fabricating method of the nonwoven shoe upper according to several embodiments of the present disclosure; and

FIG. 7 is a schematic view of the dispensing path during the steps of the dispensing process according to several embodiments of the present disclosure.

DETAILED DESCRIPTION

A plurality of embodiments of the present disclosure will be disclosed below with reference to drawings. For the purpose of clear illustration, many details in practice will be provided together with the following descriptions. However, these detailed descriptions in practice are for illustration only and shall not be interpreted to limit the scope, applicability, or configuration of the present disclosure in any way. For better illustration, the dimensions of every component in the drawing are not produced according to the actual scale. Furthermore, opposite and relative terms, such as "lower" and "upper", are used in this specification to describe relations of a component with another component. As illustrated in the figures, the purpose of opposite terms is to cover components of different directions in addition to the direction that is illustrated. The terms "first" and "second" in the specification and claims are used to specify different components or to distinguish different embodiments or ranges. They shall not be interpreted as the highest value or the lowest value to limit the quantity of the component, or the manufacturing sequence or the sequence of installation of the components.

Please note that the "nonwoven shoe upper" of the present disclosure refers to shoe uppers that are not produced by braiding/weaving methods. In other words, the nonwoven shoe upper does not comprise any interlocking (for example, weaving, knitting, looped, knotted) yarn structures. The terms "shoes" or "footwear products" in this specification generally refer to any suitable types of covering members or shielding members worn on the feet by people. The terms "inner side", "inner surface", and "inner layer" generally refer to the side, surface, and layer closer to the wearer's foot when the footwear product is worn by the wearer. The terms "outer side", "outer surface", and "outer layer" generally refer to the side, surface, and layer away from the wearer's foot when the footwear product is worn by the wearer.

Please refer to FIG. 1 and FIG. 2. FIG. 1 and FIG. 2 are schematic plan views of the nonwoven shoe upper 10, respectively, according to several embodiments of the present disclosure, wherein FIG. 1 illustrates the view of the inner surface 10A of the nonwoven shoe upper 10, and FIG. 2 illustrates the view of the outer surface 10B of the nonwoven shoe upper 10. The nonwoven shoe upper 10 can be made individually by one single process into the surface of a footwear through finishing methods such as bending, curling, cutting, punching, etc. For example, the nonwoven shoe upper 10 constitutes a shoe upper that wraps around the foot, wherein the shoe upper can comprise a vamp 12 that is located in the forefoot area and wrapping around toes and the bridge and a quarter 14 that is located in the hindfoot area and extending from the centerline of the heel counter to the vamp 12. In addition, the nonwoven shoe upper 10 surrounds an ankle opening 16 and a throat area 18, wherein the ankle opening 16 allows the foot to enter into the interior space of the shoe, and the throat area 18 extends from the ankle opening 16 toward the forefoot area and allows the shoe upper to open up, making it easier for the foot to enter the interior space of the shoe. In several embodiments, appropriate fastening pieces (for example, shoelaces) may extend across both sides of the throat area 18 in order to change the girth of the shoe upper, thus tightly securing the foot in the interior space of the shoe.

The nonwoven shoe upper 10 has a stacked layer structure, more specifically, the nonwoven shoe upper 10 comprises a base layer 110 (FIG. 1) located on a relatively inner side and a surface layer 120 (FIG. 2) disposed on the base layer 110 and located on a relatively outer side, wherein the surface layer 120 covers the base layer 110 in a direction perpendicular to the nonwoven shoe upper 10. The nonwoven shoe upper 10 comprises a plurality of polymer strips (polymer adhesive strips) P, wherein the plurality of polymer strips P are stacked and intersect with each other to form a stacked layer structure. The base layer 110 and the surface layer 120 comprise the plurality of polymer strips P, respectively, wherein the base layer 110 comprises a plurality of first polymer strips P1 stacked and intersecting with each other, and the surface layer 120 comprises a plurality of second polymer strips P2 stacked and intersecting with each other. As an additional note, "stacked and intersecting" in the present disclosure refers to a form of two different layers of polymer strips P that are stacked and intersect with each other in different directions. Given that the design is a stacked layer structure, the nonwoven shoe upper 10 can have much greater design freedom in adjusting the quantity, arrangement density, and stacking arrangement of the polymer strips P of the base layer 110 and the surface layer 120, respectively, according to the actual needs. For example, by adjusting the quantity and arrangement density of the first polymer strips P1 of the base layer 110, both the mechanical strength and air permeability of the base layer 110 can be obtained, and by adjusting the arrangement density of the second polymer strips P2 of the surface layer 120, the appearance of patterns, texture, and the tactile feel of the surface layer 120 can be constructed by design. Therefore, the overall mechanical properties, comfort, and aesthetic design of the nonwoven shoe upper 10 can be achieved.

In several embodiments, the nonwoven shoe upper 10 can be fabricated with a stacked layer structure having a different number of layers in different parts thereof. For example, in order to ensure that the forefoot area can move and bend naturally and that the hindfoot area can be covered more firmly, a stacked layer structure having relatively fewer layers is applied in fabricating the vamp 12 of the nonwoven shoe upper 10, and a stacked layer structure having relatively more layers is applied in fabricating the quarter 14 of the nonwoven shoe upper 10. In several embodiments, the nonwoven shoe upper 10 has 5 layers to 35 layers (for example, 14 layers) overall, wherein, for instance, the first layer to the third layer from the inner side to the outer side are defined as the base layer 110, and the remaining layers (for example, the fourth layer and more from the inner side to the outer side) are defined as the surface layer 120. Basically, the lower limit of the number of layers of the stacked layer structure must meet the requirement of constructing a shoe upper, whereas the upper limit can be adjusted according to actual requirements. For example, certain regions may require patterns or logos and thus are designed with a relatively greater number of stacked layers. Moreover, the nonwoven shoe upper 10 has an inner surface 10A and an outer surface 10B facing away from each other, wherein the inner surface of the base layer 110 defines the inner surface 10A of the nonwoven shoe upper 10, and the outer surface of the surface layer 120 defines the outer surface 10B of the nonwoven shoe upper 10. The inner surface of the base layer 110 may, for example, be jointly formed by the stacking and intersection of the first polymer strips P1 of the innermost layer and the sub-innermost layer (for example, the first layer and the second layer), and the outer surface of the surface layer 120 may, for example, be jointly formed by the stacking and intersection of the second polymer strips P2 of the outermost layer and sub-outermost layer (depending on the actual total number of layers).

Generally, a shoe upper not only can appropriately restrain and protect the feet of a wearer, but also can maintain both the comfort of wearing (for example, reducing the feeling of foreign objects inside the shoes, having good air permeability, etc.) and great aesthetics (for example, enhancing the three-dimensional appearance of the shoe). The interior space of the shoe beneath the shoe upper helps reduce foot fatigue and enhances the stability of wearing. The shoe upper can increase the texture of an outer appearance, and the three-dimensional design can cover minor stains and wear. These advantages shall be taken into account when the shoe uppers are made of adhesives (nonwoven uppers, non-leather uppers). Through the design of a nonwoven shoe upper 10 of the present disclosure that comprises a substantially planar inner surface 10A and a three-dimensional outer surface 10B, the nonwoven shoe upper 10 can achieve an effect of a high degree of wearing comfort and great aesthetics. In the following descriptions, features of surfaces (the inner surface 10A and the outer surface 10B) of the nonwoven shoe upper 10 of the present disclosure will be introduced in detail.

With respect to the features of the inner surface 10A of the nonwoven shoe upper 10, please refer to FIG. 3A, which is a three-dimensional schematic view of two intersecting first polymer strips P1 located on the inner surface 10A of the nonwoven shoe upper 10 according to several embodiments of the present disclosure. More specifically, any two of the first polymer strips P1 used for defining the inner surface 10A of the nonwoven shoe upper 10 that are in contact and intersect constitute a first joint C1, wherein two first polymer strips P1 that are in contact and intersect are, for example, from the first layer of strips (innermost layer) and the second layer of strips (sub-innermost layer). Furthermore, the lower surface SC1 of the first joint C1 and the lower surfaces SP1 of the two first polymer strips P1 that constitute the first joint C1 are substantially planar. In other words, in comparison with the lower surfaces SP1 of the two first polymer strips P1 that constitute the first joint C1, the lower surface SC1 of the first joint C1 does not have any noticeable protrusions or recesses. Since the entire inner surface 10A of the nonwoven shoe upper 10 comprises a plurality of first polymer strips P1 that extend and intersect with each other, as well as a plurality of first joints C1 arranged apart from each other and formed by the intersection of the first polymer strips P1, and since the lower surface SC1 of each first joint C1 and the lower surfaces SP1 of the two first polymer strips P1 that constitute the first joint C1 are substantially planar, the lower surfaces SC1 of all first joints C1 and the lower surfaces SP1 of all first polymer strips P1 are substantially planar. Namely, the entire inner surface 10A of the nonwoven shoe upper 10 is substantially planar. By the design of having the entire inner surface 10A of the nonwoven shoe upper 10 be substantially planar, not only can the feeling of foreign objects inside the shoe caused by the nonwoven shoe upper 10 and the friction and pressure between the shoe and the foot be reduced, but the risk of experiencing poor posture or falls due to ill-fitting footwear can be decreased and also foot fatigue and pain caused by long walk or standing can be reduced. As a result, such a design enhances the stability of wearing.

Please note that the aforementioned description "the lower surface SC1 of the first joint C1 and the lower surfaces SP1 of two first polymer strips P1 that constitute (are used to form) the first joint C1 are substantially planar" refers to "the lower surface SC1 of the first joint C1 being higher than the lower surfaces SP1 of the first polymer strips P1 that constitute the first joint C1 by no more than 20% of the thickness H1 of any one of the two first polymer strips P1.” In other words, the lower surface SC1 of the first joint C1 is higher than the lower surfaces SP1 of the two first polymer strips P1 that constitute the first joint C1, and the vertical distance (not shown in the figure) between the lower surface SC1 and the lower surfaces SP1 is smaller or equal to 20% of the thickness H1 of any one of the two first polymer strips P1. In several embodiments, the aforementioned vertical distance can be, for example, 16% to 20% (for example, 17%, 18%, or 19%) of the thickness H1. In a preferred embodiment, the aforementioned vertical distance can be, for example, 11% to 15% (for example, 12%, 13%, or 14%) of the thickness H1. In a more preferable embodiment, the aforementioned vertical distance can be, for example, 6% to 10% (for example, 7%, 8%, or 9%) of the thickness H1. In an even more preferable embodiment, the aforementioned vertical distance can be, for example, 1% to 5% (for example, 2%, 3%, or 4%) of the thickness H1. In a most preferred embodiment, as shown in FIG. 3A, the aforementioned vertical distance can be, for example, 0% of the thickness H1. In summary, the entire inner surface 10A of the nonwoven shoe upper 10, especially the area of lower surfaces formed by first polymer strips P1 that are stacked and intersect, is substantially flat and therefore can provide a high degree of comfort of wearing.

With respect to the features of the outer surface 10B of the nonwoven shoe upper 10, please refer to FIG. 3B and FIG. 3C, wherein the FIG. 3B is a three-dimensional schematic view of two intersecting second polymer strips P2 located on the outer surface 10B of the nonwoven shoe upper 10 according to several embodiments of the present disclosure, and FIG. 3C is a cross-sectional view of the second polymer strips P2 along the cutting plane line C-C' of FIG. 3B. More specifically, any two of the second polymer strips P2 used for defining the outer surface 10B of the nonwoven shoe upper 10 that are in contact and intersect constitute a second joint C2, wherein two second polymer strips P2 that are in contact and intersect are, for example, from the outermost layer strips and the second sub-outermost layer strips (the specific number of layer depending on the actual total number of layers). Furthermore, the thickness H of the second joint C2 is 135% to 200% (for example, 140%, 145%, 150%, 155 %, 160%, 165%, 170%, 175%, 180%, 185%, 190%, or 195%) of the thickness H2 of any one of the two second polymer strips P2 that constitute the second joint C2. In other words, in comparison with the thickness H2 of any one of the two second polymer strips P2 that constitute the second joint C2, the second joint C2 has a larger thickness H and exhibits a relatively raised configuration, such that the two second polymer strips P2 that constitute the second joint C2 exhibit a relatively recessed configuration in the non-overlapping portions in comparison with the second joint C2. In addition, the upper surface SC2 of the second joint C2 is higher than the upper surface SP2 of the two second polymer strips P2 that constitute the second joint C2. Since the entire outer surface 10B of the nonwoven shoe upper 10 comprises a plurality of second polymer strips P2 that extend and intersect with each other, and a plurality of second joints C2 arranged apart from each other and formed by the intersection of the second polymer strips P2, the entire outer surface 10B of the nonwoven shoe upper 10 exhibits a non-flat configuration with alternating raised and recessed portions (that is, an uneven surface). By the design of having the entire outer surface 10B of the nonwoven shoe upper 10 be non-planar, a three-dimensional appearance of a shoe can be constructed. The design can enhance the texture of the outer appearance and effectively cover minor stains and wear, thus prolonging service life of the product. In several embodiments, the design of a specific three-dimensional appearance can provide specific functions, for example, displaying specific patterns and icons, adjusting air permeability, and covering capability, etc.

For the actual forms of the inner surface 10A and the outer surface 10B of the nonwoven shoe upper 10, please refer to FIG. 4A and FIG. 4B, wherein FIG. 4A shows an image of the inner surface 10A of the nonwoven shoe upper 10 generated by an optical microscope according to several embodiments of the present disclosure, and FIG. 4B shows an image of the outer surface 10B of the nonwoven shoe upper 10 generated by an optical microscope according to several embodiments of the present disclosure. As shown in FIG. 4A, the overall inner surface 10A of the nonwoven shoe upper 10 at least formed by the first polymer strips P1 that are stacked and intersect is substantially flat. On the other hand, as shown in FIG. 4B, the overall outer surface 10B of the nonwoven shoe upper 10 at least formed by the second polymer strips P2 that are stacked and intersect exhibits a non-flat configuration with alternating raised and recessed portions.

Please refer to FIG. 3A and FIG. 3B again. In several embodiments, the line width W1 of the first polymer strips P1 and the line width W2 of the second polymer strips P2 can be the same or different, and the line width ranges from 0.5 mm to 3 mm (for example, 1 mm, 1.5 mm, 2 mm, or 2.5 mm). In several embodiments, the first polymer strips P1 that belong to the base layer 110 are mainly for providing specific mechanical characteristics and providing the effect of air permeability. Therefore, if the line width W1 is too small, the first polymer strips P1 may not effectively provide sufficient adhesion between the first polymer strips P1. As a result, the overall tensile strength of the nonwoven shoe upper 10 is insufficient. On the contrary, if the line width W1 is too large, the first polymer strips P1 may not provide good air permeability. In several embodiments, the second polymer strips P2 that belong to the surface layer 120 are mainly for providing a good visual effect in appearance and helping providing specific mechanical characteristics and providing the effect of air permeability with the base layer 110. Therefore, if the line width W2 is too small, the outer surface 10B of the nonwoven shoe upper 10 may result in insufficient three-dimensional appearance, leading to an excessively smooth surface with reduced dimensionality. On the contrary, if the line width W2 is too large, the surface layer 120 may affect the air permeability of the nonwoven shoe upper 10. In several embodiments, the mechanical characteristics of the nonwoven shoe upper 10 can be reflected by the tensile strength of the nonwoven shoe upper 10, in which the tensile strength of the nonwoven shoe upper 10 is at least 25 Newtons per centimeter (N/cm). The nonwoven shoe upper 10 with such tensile strength can provide sufficient flexibility (softness) while carrying out general activities, reduce any uncomfortable feeling while wearing the shoes, and have sufficient mechanical properties to withstand fast and intense activities. The tensile strength of the nonwoven shoe upper 10 is tested and obtained by the standard method ASTM D5035-11 issued by American Society for Testing and Materials (ASTM).

Please refer to FIG. 5, which is a schematic cross- sectional micro-scale view of the first polymer strips P1 or the second polymer strips P2 according to several embodiments of the present disclosure. In several embodiments, after the nonwoven shoe upper 10 of the present disclosure is shaped into a polymeric fabric-like structure after the dispensing, arranging, and curing processes, the nonwoven shoe upper 10 undergoes a foaming treatment, so that surfaces of strips become fluffy, thereby effectively improving the tactile feel and increase the sweat absorption, so as to enhance comfort of wearing. Due to the foaming process (further explanation will be provided later), the first polymer strips P1 and the second polymer strips P2 have a plurality of porous structures O, respectively. The porous structures O not only help reduce the density of the material, which makes the nonwoven shoe upper 10 be lightweight, but also absorb impact to provide additional buffering and support effects. The overall effect can improve the comfort of wearing and exercise performance. Furthermore, the porous structures O can maintain the stability of the nonwoven shoe upper 10 under any weather condition, provide shoes with good weather resistance, and prolong the service life of shoes. In several embodiments, the porous structures O are micro-scale structures. In other words, the hole diameter of a single porous structure O is 10 μm to 800 μm. In comparison with porous structures at a nanometer scale, the porous structures O at a micrometer scale are relatively less likely to collapse or deform, providing buffer and support effects that last longer. The porous structure O on a micrometer scale can provide relatively higher air permeability, resulting in a better wearing experience.

In several embodiments, due to the foaming process (further explanation will be provided later), the first polymer strips P1 and the second polymer strips P2 have a material apparent density, respectively. Designs of the range of the material apparent density help achieve weight reduction of the nonwoven shoe upper 10 while maintaining its mechanical properties. In several embodiments, when the first polymer strips P1 and the second polymer strips P2 have a larger material apparent density, respectively, it means that the materials tend to be over-dense and will not achieve the goal of having a lightweight nonwoven shoe upper 10. When the first polymer strips P1 and the second polymer strips P2 have a smaller material apparent density, respectively, it means that there are too many porous structures O in the materials, which may result in insufficient protection and support and may easily cause uneven cushioning performance.

In several embodiments, the nonwoven shoe upper 10 of the present disclosure can be produced through dispensing (or, including foaming) methods along with curing methods for adhesive. The present disclosure can fabricate adhesive-formed shoe uppers of special designs. Hereby, a nonwoven shoe upper 10 having both a substantially planar inner surface and a three-dimensional outer surface can be fabricated. The following descriptions introduce the fabricating method of the nonwoven shoe upper 10 of the present disclosure by way of embodiments with reference to the accompanying drawings, mainly FIG. 6 along with FIG. 1 to FIG. 5, for illustration.

Please refer to FIG. 6. The fabricating method of a nonwoven shoe upper 10 comprises steps S10 to S40. In step S10, the dispensing solution is prepared. In step S20, the curing process is performed so that the dispensing solution undergoes patternization and forms a polymeric fabric-like structure including a plurality of polymer strips that are stacked and intersect. In step S30, an emplacing step is carried out, so that the polymer strips that are stacked and intersect are cured (solidified) completely and form a nonwoven shoe upper 10. In several embodiments, after step S30 is completed, an additional step S40, a foaming step, can be applied to the nonwoven shoe upper 10 to form a foamed nonwoven shoe upper 10 after the foaming process. Further descriptions of each step will be given below.

First, in step S10, a polymer is added in the solvent to form the dispensing solution to be used in the dispensing process, wherein the polymer is used as the main material of the nonwoven shoe upper 10. In several embodiments, the polymer can be thermoplastic polyurethane (TPU) that has good compression modulus, tensile modulus, and flexural modulus, as well as good anti-impact strength, which enhances the mechanical properties of the nonwoven shoe upper 10. Furthermore, thermoplastic polyurethane has good flexibility and wear resistance, and therefore, both tactile feel and comfort of wearing can be achieved for the nonwoven shoe upper 10. In several embodiments, the polymer can be, but not limited to, polyethylene terephthalate (PET), nylon, polypropylene (PP), polyethylene (PE), polycarbonate (PC), epoxy resin, etc.

Solvents can dissolve and dilute polymers to form a dispensing solution that has higher fluidity than that of polymer, in order to fulfill the subsequent dispensing step. In several embodiments, the polymer has a weight percentage concentration in the solvent of 5% to 90% (for example, 10%, 20%, 30%, 40 %, 50%, 60%, 70%, and 80%). More specifically, the weight percentage concentration of the thermoplastic polyurethane used in this embodiment in the solvent can be, for example, 22.5% to 27.5% (for example, 25.0%). By setting the concentration of the polymer within this range, it benefits the process of dispensing the dispensing solution smoothly and maintaining the desired product shape before the curing process, and achieves better control of the dispensing step. In several embodiments, an excessively high concentration of the polymer may lead to low fluidity of the dispensing solution, making it difficult to perform the dispensing step uniformly and stably, and may even cause high energy consumption due to the increase in pressure in the dispenser. A n excessively low concentration of the polymer may lead to excessively high fluidity of dispensing solution, which causes overflowing during the dispensing process and prevents polymer strips from being formed, and even leads to excessively high permeability of dispensing solution, making it difficult for the adhesive to be stacked by dispensing into a laminated structure with a desired thickness.

In several embodiments, the solvent is a co-solvent comprising a primary solvent and an auxiliary solvent, wherein the polymer has a higher solubility in the primary solvent and has a lower solubility in the auxiliary solvent. The primary solvent and the auxiliary solvent have different boiling points. The primary solvent ensures the polymer dissolves uniformly. The auxiliary solvent, having a different boiling point than that of the primary solvent, is for adjusting the overall vaporization speed of the solvent during the subsequent curing step, so that the curing speed of the strips formed by the dispensing solution can be controlled in response to different product requirements (descriptions will be provided later). In several embodiments, the difference in boiling points between the primary solvent and the auxiliary solvent ranges from 10°C to 150°C (for example, 14°C, 73°C, 75°C, 85°C, 97°C, 99°C, 109°C, or 130°C). In other words, the primary solvent and the auxiliary solvent can have either a large difference in boiling points or a small difference in boiling points in order to cope with the need of different curing speeds, thereby allowing flexible combinations to provide a solvent with appropriate volatility. In several embodiments, the primary solvent can be, for example, tetrahydrofuran (THF), cyclohexanone, dimethylformamide (DMF), dimethylacetamide (DMAC), dimethyl sulfoxide (DMSO), or N-methylpyrrolidone (NMP), and the auxiliary solvent can be, for example, acetone or methyl ethyl ketone. In several other embodiments, the co-solvent comprises two different primary solvents, for example, tetrahydrofuran together with cyclohexanone, in order to achieve better dissolution. Furthermore, the formulation of the dispensing solution Q of the present disclosure is designed for dispensing operations at an ambient temperature.

Next, in step S20, the polymeric fabric-like structure, having a plurality of polymer strips that are stacked and intersect, is formed after the dispensing, arranging, and curing processes of layer by layer of polymer strips. Please refer to FIG. 7, which is a schematic view of the dispensing path during the steps of the dispensing process according to several embodiments of the present disclosure. Meanwhile, FIG. 7 can be used as an example of the configuration formed by polymer strips P that are stacked and intersect with each other, which belong to different layers of strips (for example, the first layer of strips L1 and the second layer of strips L2). More specifically, the dispensing operation can be performed on the supporting surface 201 of the substrate 200 according to the upper outline patterns, so that the dispensing solution Q forms a plurality of polymer strips P on the supporting surface 201. Polymer strips P formed in this operation belong to the first layer of strips L1 (inner layer). Due to the characteristic of the dispensing solution Q of the present disclosure (that is, the solvent-containing characteristics of the dispensing solution Q), the solvent in the strips after the dispensing operation begins to evaporate gradually, and the polymer originally dissolved/distributed in the solvents remain. In other words, once the strips are dispensed on the supporting surface 201 of the substrate 200, the strips may begin to gradually cure. Next, step S20 is repeated at a proper time to form a plurality of polymer strips P intersecting with the first layer of strips L1 and on the first layer of strips L1, wherein polymer strips P constructed in this step belong to the second layer of strips L2 (outer layer). Hereby, by repeating step S20 multiple times, parts of the base layer 110 and the surface layer 120 are gradually stacked layer by layer. Please note that in the following description of the present disclosure, whether the strips are in a just-dispensed state (with the solvent not yet evaporated) or in a partially or fully cured state (with the solvent partially or fully evaporated), they are represented as polymer strips merely to indicate the presence of the actual physical elements. When it is necessary to specifically clarify the presence of the solvent, it will be particularly described.

In order to construct a substantially planar inner surface 10A (provided by the base layer 110) and a three-dimensional design of an outer surface 10B (provided by the surface layer 120) of the nonwoven shoe upper 10 of the present disclosure, when step S20 of dispensing and curing operations are performed, the vaporization and curing period of each layer of strips must be effectively controlled according to the physical properties of the dispensing solution Q (for example, the volatility of the solvent in the dispensing solution Q). With respect to the base layer 110, the process of stacking different layers of strips is controlled in order to complete the process before the solvent has evaporated or fully evaporated. By doing so, the first joints C1, formed by the first polymer strips P1 of the base layer 110, which are stacked and intersect, can have a better infiltration effect, in order to provide a substantially planar inner surface 10A. On the other hand, with respect to the surface layer 120, the dispensing process is controlled to let the solvent in the second polymer strips P2, located in inner layers, evaporate to a certain degree before more strips located in outer layers are dispensed. By doing so, the second joints C2, formed by the second polymer strips P2 of the surface layer 120, which are stacked and intersect, can have a substantially stacking effect in structure, in order to provide a three-dimensional sense of appearance. Further descriptions will be provided later.

In FIG. 7, the polymer strips P are dispensed, for example, in a continuous path (the path of the first layer of strips L1 shown in the figure) or in a discontinuous path (the path of the second layer of strips L2 shown in the figure). Furthermore, the dispensing operation in step S20 not only can continuously dispense the dispensing solution through the dispensing nozzle M, as shown in FIG. 7, but also can dispense droplets of the dispensing solution to construct adhesive-formed strips that are stacked and intersect to form an adhesive-formed shoe upper. In addition, in several embodiments, a slit coating method can be employed to spray line-shaped adhesive directly, which is then stacked and intersected to construct an adhesive-formed shoe upper.

More specifically, the design and configuration of the concentration of the polymer in the dispensing solution Q not only can affect the fluidity of the dispensing solution Q (as described previously), but also is one of the factors that control the line width of the polymer strips P. In several other embodiments, the parameter design of the dispensing equipment is also used to control the line width of the polymer strips P. For example, a dispensing speed of about 1 mm/second to 100 mm/second and a dispensing pressure of about 0.1 megapascal (MPa) to 1 MPa (pressure applied to the dispensing nozzle M) are applied in the dispensing operation. An appropriate dispensing speed and an appropriate dispensing pressure will improve the accuracy of the dispensing process to ensure the dispensing solution is dispensed smoothly and maintains the desired shape. In several embodiments, when the dispensing speed is too high , the dispensing solution Q may have an irregular shape or inconsistent size while being dispensed. When the dispensing speed is too low, the dispensing solution Q may be accumulated at specific positions, resulting in an irregular line width of the polymer strips P. When the dispensing pressure is too high, the dispensing solution Q may overflow while being dispensed and cause damage to the equipment. When the dispensing pressure is too low, the dispensing solution Q may be unstably dispensed, resulting in breaks in the polymer strips P.

In several embodiments, the dispensing operation performed at a temperature of -5°C to 40°C (for example, 0°C, 10°C, 20°C, 30°C), or for example at the ambient temperature, can enhance the stability of the dispensing solution Q, achieve energy saving, and prolong the service life of the dispenser. In several embodiments, the substrate 200 is a glass substrate in order to provide a higher flatness and better thermal stability. Since the glass substrate is transparent, it is easier to observe the dispensing condition. In several embodiments, the substrate 200 may not only be a planar substrate, but may also, for example, be an curved flat-surfaced substrate, (2.5D), or a last substrate (3D), allowing the nonwoven shoe upper 10 formed on the curved flat-surfaced substrate or the last substrate to directly achieve a molded shape conforming to the substrate.

Continuing from the foregoing, the principles of the dispensing and curing design of the present disclosure will be further described. The present disclosure applies the method of evaporation of solvent to curing the polymer strips P during the curing process (also known as solvent-evaporation curing). In comparison with curing polymer strips by cooling a solvent-free molten polymer (also referred to as melt-cooling curing), the s olvent-evaporation curing of the present disclosure enhances the mechanical properties (for example, tensile strength) of the nonwoven shoe upper 10. More specifically, since the solvent has high fluidity, when the dispensing solution Q is dispensed on the substrate 200, the polymer in the dispensing solution Q can change the position of its chains with the flow of the solvent, and as the solvent gradually and slowly evaporates, an ordered and dense arrangement is progressively formed, thereby producing a stable structure that provides high mechanical strength between the cured polymer strips P. Moreover, as described above, after polymer strips P in a relatively inner layer (e.g., the first layer of strips L1) are formed, when new polymer strips P are deposited on top of the inner layer to further form an outer layer (e.g., the second layer of strips L2), the solvent in the polymer strips P of the outer layer may infiltrate into the polymer strips P of the inner layer. That is, at the intersections of the two polymer strips P, the polymers in the outer layer strips P can mix with the polymers in the inner layer strips P as the solvent flows, and during the gradual and slow evaporation of the solvent, an ordered and dense chain arrangement is progressively formed at the intersection, thereby creating a stable junction (e.g., the aforementioned first joint C1 and second joint C2). In contrast, because melt-cooling curing does not involve solvent evaporation, it cannot achieve the effect of enhancing the mechanical properties of the nonwoven shoe upper 10.

In comparison with melt-cooling curing, solvent-evaporation curing of the present disclosure can achieve the goal of a lightweight nonwoven shoe upper 10. More specifically, during the curing process, the solvent evaporates, resulting in a decrease in overall weight of the polymer strips P, and thereby forming polymer strips P with lower polymer content per unit volume. On the other hand, since melt-cooling curing does not involve solvent evaporation, the polymer strips P created by melt-cooling curing have higher polymer content per unit volume and thus cannot achieve the goal of a lightweight nonwoven shoe upper. Please note that the method of solvent-evaporation curing of the present disclosure seems to reduce the density of the polymer in the polymer strips P, which may not be conducive to enhancing the mechanical properties of the nonwoven shoe upper 10 at first. However, as described previously, since the polymer can spontaneously form an ordered and dense chain arrangement when the solvent gradually and slowly evaporates, cured polymer strips P can still have high mechanical strength. Therefore, both the goals of lightweight products and structural stability can be achieved.

Furthermore, the method of solvent-evaporation curing of the present disclosure is conducive to the control of the stacking condition of two adhesive-formed strips at the intersection place, and the degree of protrusion at the joints (for example, the first joints C1 and the second joints C2 described previously). For example, when forming polymer strips P corresponding to the base layer 110, after the polymer strips P of the relatively inner layer are formed, the dispensing/waiting time between adjacent layers may be controlled to be short, or the solvent evaporation rate in the polymer strips P of the inner layer may be slowed. This allows the subsequently formed polymer strips P of the relatively outer layer to infiltrate into the polymer strips P of the inner layer at the overlapping regions, thereby enabling the components of the two polymer strips P to mix at the overlapping regions and form a relatively flat junction (first joint C1). As a result, a relatively flat base layer 110 can be formed, which facilitates constructing a stable foundation for stacking the surface layer 120 on top. In one other example, when forming polymer strips P corresponding to the surface layer 120, after the polymer strips P of the relatively inner layer are formed, the dispensing/waiting time between adjacent layers may be controlled to be long, or the solvent evaporation rate in the polymer strips P of the inner layer may be accelerated. This allows the subsequently formed polymer strips P of the relatively outer layer to only partially infiltrate into the polymer strips P of the inner layer, or to adhere solely to the top surface of the inner-layer polymer strips P without penetrating into them. As a result, the polymer strips P of the outer layer are raised, forming relatively protruding junctions (second joint C2), thereby creating a surface layer 120 with an overall more three-dimensional appearance. Since the polymer strips P in each layer comprise the same polymer, even when the polymer strips P of the relatively inner layer have been cured completely, the cured polymer strips P of the relatively outer layer still can stably bond with the cured polymer strips P of the relatively inner layer due to homogeneity of materials.

In several embodiments, when the dispensing solution Q is dispensed on the supporting surface 201 of the substrate 200 to form polymer strips P, air flow is supplied to the polymer strips P continuously to control the evaporation speed of the solvent in the polymer strips P through adjusting the temperature and the flow speed of the air flow, thus controlling the curing speed of the polymer strips P. In several embodiments, the temperature of the air flow is adjusted appropriately within the range of 30°C to 40°C. In several embodiments, photocuring particles may be added to the dispensing solution Q, or a photocuring dispensing solution Q is applied directly. Moreover, after the dispensing solution Q is dispensed on the supporting surface 201 of the substrate 200 to form the polymer strips P, ultraviolet light (UV light) is used to control the curing speed of the polymer strips P.

Next, in step S30, an emplacing step is carried out. The present disclosure fabricates products through dispensing in the form of fine strips, and employs solvent-evaporation curing to establish a stable connection between intersecting polymer strips P. Therefore, after the polymeric fabric-like structure is produced on the substrate 200 by stacked polymer strips P that intersect with each other, the entire stacked layer structure (that is, the entire polymeric fabric-like structure) together with the substrate 200 are left undisturbed to prevent the polymer strips P that are not completely cured from having defects, such as a twisted and deformed shape, or cracks, caused by external impact force (for example, displacement, bending, etc.). In several embodiments, the fabricated material can be left undisturbed at an ambient temperature of 30°C for a specific period of time, for instance, at least 12 hours, for all the polymer strips to be cured completely. Hereby, after the aforementioned operation, a nonwoven shoe upper 10 made by polymer strips that are stacked and intersect with each other is fabricated after the entire stacked layer structure is removed from the substrate 200, and is ready for subsequent assembly of shoes.

Please refer to FIG. 7. In several embodiments, the dispensing step in step S20 starts with dispensing the solution along the periphery path E of the outline pattern of the shoe upper to form a border line B, then continues dispensing the solution along the inner path I to lay out multiple polymer strips P as needed, wherein the periphery path E defines the boundary of the outline pattern of the shoe upper. In other words, the adhesive-formed material falling outside the periphery path E will not be visible in the final assembled nonwoven shoe upper 10. In several embodiments, the border line B may have a relatively larger width, thereby extending beyond the periphery path E. As a result, after the curing operation of step S20 and the emplacing process of step S30 are completed, the entire stacked layer structure including the border line B can be directly removed from the substrate 200, and the portion of the border line B beyond the periphery path E (that is, the border line B located outside the periphery path E) can be folded into the shoe body in order to hide the excess adhesive material, or the excess adhesive material can be cut off from the border line B along the periphery path E.

In several embodiments, while preparing the dispensing solution in step S10, foaming agents are further added to the solution. In this way, during the curing process of step 20, after the solvent gradually evaporates, the polymer and the foaming agent that originally dissolved/distributed in the solvent remain. Hereby, the entire nonwoven shoe upper 10 formed by the adhesive material after the curing process further undergoes step S40 to put the nonwoven shoe upper 10 through a foaming step. The foaming effect is introduced to the first polymer strips P1 that are located in the base layer 110 and the second polymer strips P2 that are located in the surface layer 120 of the nonwoven shoe upper 10. More specifically, during the foaming step, the foaming agent in the cured adhesive-formed strips releases gas when heated. The gas can create a vast amount of porous structures O in the polymer, and the porous structures O gradually expand to push apart the polymer as the gas is released continuously. As a result, the entire cured adhesive-formed strips expand to form the polymer strips of the present disclosure. In several embodiments, the foaming agent is, for example, thermoplastic-expandable microspheres that comprise a polymeric shell and a component filled within the shell that can generate gas upon heating. In several embodiments, the shell of the foaming agent is degraded at the same time when the gas is released, so that the polymer strips do not contain the foaming agent or only contain a small amount of foaming agent. In several other embodiments, the material of the shell of the foaming agent is selected from the same material as the polymers (for example, polyurethanes) in order to be integrated into the polymer strips. In several embodiments, the heating condition to trigger the foaming reaction of the thermoplastic-expandable microspheres is, for example, at 1 atmosphere pressure and a temperature of 100℃-220℃ with uniform temperature control to maintain a stable and gradual foaming. In several embodiments, the foaming method is supercritical foaming or chemical foaming.

During the foaming process, the first polymer strips P1 that correspond to the base layer 110 and located closer to the substrate 200 will contact the surface of the substrate 200 during the foaming process. In other words, the space for expansion of the first polymer strips P1, close to the substrate 200, is limited by the surface of the substrate 200. Therefore, after the foaming, multiple first polymer strips P1 that constitute the inner surface of the base layer 110 can still form a substantially planar surface. That is to say, the nonwoven shoe upper 10 after the foaming process still has a substantially planar inner surface 10A, as shown in FIG. 3A. On the other hand, the space for expansion of the second polymer strips P2 that corresponds to the surface layer 120 and located closer to the outside are not limited by any other layers. Therefore, the foaming step will not affect the original three-dimensional appearance of the outer surface 10B of the nonwoven shoe upper 10, and a rough surface resulting from the foaming process can produce a matte visual effect, as shown in FIG. 3B. Moreover, the foaming step makes the nonwoven shoe upper 10 have a three-dimensional fluffy appearance, which effectively improves both tactile feel and comfort of wearing of the inner surface 10A and the outer surface 10B of the nonwoven shoe upper 10.

In several embodiments, the expansion ratio of the nonwoven shoe upper 10 is controlled within 105% to 130% (for example, 110%, 115%, 120%, or 125%). A proper expansion ratio can ensure both the mechanical properties and tactile feel of the nonwoven shoe upper 10. In several embodiments, when the expansion ratio is larger than 130%, the volume of the polymer strips P becomes too large (line width to be too large), resulting in a larger quantity of the porous structures O per unit volume in the polymer strips P. The material density of an entire polymer strip P is therefore too low, and an entire polymer strip P cannot withstand large stress, and, as a result, the mechanical properties of the nonwoven shoe upper 10 are degraded. However, when the expansion ratio is smaller than 105%, the foaming process may not provide the nonwoven shoe upper 10 with a three-dimensional fluffy appearance and a sense of friction.

In several embodiments, if the nonwoven shoe upper 10 is to undergo a foaming process, a pre-compensation value is calculated based on the required expansion ratio during the curing step, and the line width of the polymer strips P to be fabricated during the dispensing process is controlled according to the pre-compensation value, so that the line width of the polymer strips P after foaming will meet the required line width by design. Appropriate and sufficient spaces among the polymer strips P need to be secured in order to achieve the mechanical properties, comfort of wearing (air permeability, sweat absorption capability, tactile feel), and the effect of visual appearance. The weight of the shoe upper is reduced effectively by the foamed nonwoven shoe upper 10, and the lightweight effect can be achieved. The aforementioned line width of the polymer strips P, ranging from 0.5 mm to 3 mm, may be the line width after considering the pre-compensation value. In several embodiments, if the line width of the dispensed polymer strips P is too small, the polymer strips P may not be able to provide sufficient strength after foaming, and the entire tensile strength of the nonwoven shoe upper 10 is insufficient. Besides, when the line width is too thin by design, the polymer strips P can easily break before curing, which makes the production more difficult. However, if the line width of the dispensed polymer strips P is too large, there may not be enough space for the polymer strips P to expand during the forming step and the polymer strips P will be in contact with one another during the foaming step that degrades air permeability thereof and, in some cases, deforms the nonwoven shoe upper 10 due to pressing between the polymer strips P.

According to the aforementioned embodiments of the present disclosure, through the design of a nonwoven shoe upper of the present disclosure that comprises a substantially planar inner surface and a three-dimensional outer surface, the nonwoven shoe upper can achieve a high degree of wearing comfort and great aesthetics. On the other hand, through the use of dispensing (or, including foaming) methods along with curing methods for adhesive, the present disclosure can fabricate adhesive-formed shoe uppers of special designs. Therefore, problems in making shoe uppers using conventional methods of weaving or braiding yarn into jacquard can be overcome, and a nonwoven shoe upper with a substantially planar inner surface and a three-dimensional outer surface can be produced that makes an adhesive-formed shoe upper have a high degree of wearing comfort, air permeability, and great aesthetics similar to that of jacquard fabric made from weaving yarn.

The above preferred embodiments are presented to disclose the present disclosure and shall not be interpreted to limit the scope, applicability, or configuration of the present disclosure in any way. Those skilled in the art may use any alternative embodiments that are modified or changed without departing from the spirit and scope of the present disclosure and shall be included in the appended claims.

COMPONENT SYMBOL

10: Nonwoven shoe upper

10A: Inner surface

10B: Outer surface

12: Vamp

14: Quarter

16: Ankle opening

18: Throat area

110: Base layer

120: Surface layer

200: Substrate

201: Supporting surface

P: Polymer strips

P1: First polymer strips

P2: Second polymer strips

C1: First joint

C2: Second joint

SP1, SC1: Lower surface

SP2, SC2: Upper surface

O: Porous structure

Q: Dispensing solution

M: Dispensing nozzle

L1: First layer of strips

L2: Second layer of strips

E: Periphery path

I: Inner path

B: Border line

H1, H2, H: Thickness

W1, W2: Line width

S10~S40: Step

C-C': Cutting plane line