SYSTEMS AND METHODS FOR MAKING A LIGNIN PAPER POUCH, CONTAINER, OR SEALING STRUCTURE

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Application No. 63/734,711, filed on Dec. 16, 2024, and entitled “System and Methods for Making a Lignin Paper Bag, Container, or Sealing Structure,” the entire contents of which is incorporated by reference herein in its entirety.

REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable

SEQUENTIAL LISTING

Not applicable

BACKGROUND OF THE DISCLOSURE

Field of the Invention

The present disclosure generally relates to systems and methods for making a lignin paper pouch or container that may be made partially or entirely of repulpable and/or recyclable paper, and more particularly to lignin paper pouches and containers with bodies and sealing structures that are also or alternatively made of repulpable and/or recyclable paper.

Description of the Background of the Invention

Historically, re-closeable pouches and containers (collectively “bags”) that are used in food and household storage and packaging comprise one or more of a folded web of elastomeric material, a web formed of blown, cast, monolayer, or co-extruded films, or a silicone-based mixture that may be liquid injection molded, all of which generally have two side walls that are connected along the bottom and opposing sides. The bags typically include a re-closable fastener or closure system at a top of the bag, such as, for example, an adhesive, a wire tie, or zipper. While thermoplastic and elastomeric bags have a variety of benefits, including reduced cost and ease of manufacture, efficient packaging and transport, and desirable sealing capabilities for end use, such bags are not recyclable or repulpable, and given consumer trends related to recyclable and repulpable packaging, new and improved bags are desired that maintain the benefits associated with prior art bags.

It is therefore desirable to maintain or enhance the benefits of prior art bags through the use of materials that are configured to be recycled or repulped, i.e., by using one or more sustainable materials. It is further desirable to optimize sealing structures used with such repuplable and/or recyclable bags, pouches, or containers, including by having a simple sealing structure that is capable of providing an optimized seal for the intended use of each particular bag and that can be used in various rigorous applications.

Furthermore, the current state of the art in paper bags or products focuses on the repulpability of the product rather than the recyclability. Creating a recyclable paper bag or product would address the consumer desire for a more sustainable product.

SUMMARY OF THE DISCLOSURE

According to some embodiments, a pouch or container for food packaging includes a body defining a left side, a right side, a bottom side, and a mouth at an upper end thereof that provides access into a cavity of the pouch, and a sealing structure that is configured to allow access into the cavity of the pouch in an open configuration and to prevent access into the cavity of the pouch in a closed configuration. The body of the pouch includes lignin. In some embodiments, the sealing structure also includes lignin. In some embodiments the lignin includes softwood lignin, hardwood lignin, and annual plant lignin. The lignin may be sulfur free or sulfur baring. In some embodiments, up to 100% of the pouch is made from lignin.

In some embodiments, the body of the pouch may further include at least one repulpable, plant-based material. In some embodiments, the sealing structure of the pouch may also include at least one repulpable, plant-based material. In some embodiments the repulpable, plant-based material includes an organic material selected from the group consisting of wood pulp, paper fibers, cotton, linen, silk, wool, wheat straw, sugar cane waste, flax, bamboo, wood, linen rags, esparto, manilla, jute, palm fiber, mulberry, coconut husk, agave, reed grass, and hemp.

The body of the pouch may also include a water-insoluble polymer that is not lignin. In some embodiments, the sealing structure of the pouch may also include a water-insoluble polymer that is not lignin. In some embodiments, the water-insoluble polymer component includes polyolefins, hexanes, poly(lactic acid)s, polyhydroxyalkanoates, chitosans, polyimides, polysiloxanes, acrylic polymers, polybenzoxazines, polyvinyl acetates, polyethylenes, polystyrenes, polyvinyl acetate copolymers, polyacrylates, polyethers, styrene-maleic anhydrides and combinations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a plant-based pouch with a first sealing structure shown in an open configuration, as disclosed herein;

FIG. 2 is a schematic view of the pouch of FIG. 1 with the first sealing structure shown in a closed configuration;

FIG. 3 is a side cross-sectional view of a second sealing structure including a male portion and a female portion shown in an open configuration; and

FIG. 4 is a female portion of a sealing structure formed via extruding a blend of paper and kitchen oil.

Other aspects and advantages of the present disclosure will become apparent upon consideration of the following detailed description, wherein similar structures have similar reference numerals.

DETAILED DESCRIPTION

The present disclosure is directed containers or pouches (collectively “bags”), and the associated bodies and sealing structures for the pouches, wherein the body comprises lignin, and in some embodiments, the sealing structure also comprises lignin. In a preferred implementation, the body and sealing structure for the pouch are made entirely or partially from repulpable and/or recyclable materials, such as paper. More specifically, the present disclosure is directed to a body comprising lignin for a re-closeable pouch, a sealing structure for a re-closeable pouch, and a method of making a pouch, body, and sealing structure therefor. While the systems and methods disclosed herein may be embodied in many different forms, several specific embodiments are discussed herein with the understanding that the embodiments described in the present disclosure are to be considered only exemplifications of the principles described herein, and the disclosure is not intended to be limited to the embodiments illustrated.

Throughout the disclosure, the terms “about” and “approximate” mean plus or minus 5% of the number or value that each term precedes. As used herein, the phrase “leak resistant seal” refers to a seal that resists leakage of liquids and solids from the container during storage and transport without the aid of an external structure to maintain the seal. Finally, the term “closure element” is defined herein to mean one part of a closure system that is configured to close a pouch. The closure system may comprise a sealing structure used to seal the pouch wherein the sealing structure comprises one or more closure elements. For example, on a zipper sealing structure, a closure element is one profile or the other of the zipper, e.g., a rib profile or a groove profile.

The pouches, bodies, and sealing structures disclosed herein may be entirely or partially repulpable and/or recyclable. In some embodiments, the pouches, bodies, and sealing structures disclosed herein may be made entirely or partially of lignin. The pouches may take varying forms, and representative examples are provided in FIGS. 1-4. As used herein, the term “repulpable” refers to a plant-based material whose fibers can be broken down and returned to the pulp state and suspended in a liquid such as water, i.e., material that can undergo the operation of re-wetting and fiberizing for subsequent sheet formation. The dissociated fibers can then be re-used (e.g., re-combined) to make a new repulpable material. Examples of repulpable materials include various papers, cardboards, and other cellulose-based materials. The bodies and/or sealing structures of the pouches disclosed herein may enable production of fully repulpable and/or recyclable flexible packages that can be opened and re-closed by a consumer. In some embodiments, the body of the pouch includes a repuplable pressure sensitive adhesive. In further embodiments, the sealing structure of the pouch includes a repuplable pressure sensitive adhesive.

As further used herein, “recyclable” material means “used material that is capable of being processed into new paper or paperboard.” A paper product that is recyclable must be repulpable, but a paper product that is repulpable is not always recyclable. Repulpability may be tested through a method of blending paper material with water into a pulp, filtering the pulp, and determining how much fiber can be recovered. Recyclability may be tested by pulping the paper product and converting it into a new sheet that is then put through a series of quality tests to validate both properties and appearance. In some embodiments, the lignin is removed from the repulpable, plant-based material (or “pulp”) entirely.

The repulpable, plant-based material pulp may comprise one or more different types of organic materials that may be made from cellulose, tannin, cutin, and/or lignin. The organic materials may come from various plants, including cotton, wheat straw, sugar cane waste, flax, bamboo, wood, linen rags, esparto, manilla, jute, palm fiber, mulberry, coconut husk, agave, reed grass, and/or hemp. In some embodiments, the end pulp/binder mixture is configured to be heat resistant up to 451° F (232° C), freezer capable, and oven and microwave resistant. Preferably, the pulp/binder mixture in its end form is water and oil resistant. In some embodiments, the binder is entirely made from or includes RTV silicone. In some embodiments, the zipper profile is separately combined with and/or joined to a paper pouch to make a fully recyclable paper pouch product.

The advantages of the repulpable and/or recyclable pouches disclosed herein are: 1) improved environmental performance; 2) waste is eliminated since the leftover pouches do not have to be disposed of and less material is wasted in the mixing process, and 3) material utilization is improved since all the material in the pouch ends up in the mixer and none otherwise enters into the environment. The paper comprising the pouches may include kraft paper, twisted paper, greaseproof paper, recycled paper, coated paper, cotton, offset paper, paperboard, duplex paper, or combinations thereof. In some embodiments, repulpable tape may be included, which may comprise water soluble modified acrylic adhesive, coated on a repulpable paper carrier, such that the repulpable tape’s backing and glue can be dissolved in water. In some embodiments, recyclable tape may be utilized.

The body and, in some embodiments, the sealing structure of the pouch may include at least one repulpable, plant-based material. In some embodiments, more than 10%, or more than 20%, or more than 30%, or more than 40%, or more than 60%, or more than 70%, or more than 80%, or more than 85%, or more than 90%, or more than 95% of the body may include at least one repulpable, plant-based material. In further embodiments, the sealing structure of the pouch also includes at least one repulpable, plant-based material. In some embodiments, more than 10%, or more than 20%, or more than 30%, or more than 40%, or more than 60%, or more than 70%, or more than 80%, or more than 85%, or more than 90%, or more than 95% of the sealing structure may include at least one repulpable, plant-based material.

As noted above, the pouches, bodies, and sealing structures of the present disclosure are made of paper or paper-like materials, and in some embodiments are made using a pulp/binder mixture. In some embodiments, the sealing structure is a zipper that includes a male profile and a female profile. The details of the body and sealing structure of the pouch may be modified based on a user’s intended use and are not limited to the embodiments disclosed herein. While the ratio of the pulp/binder mixture may be modified based on intended use, in some embodiments more than 50% of the mixture comprises pulp or a similar substance, e.g., potato fibers, vegetable fibers, or other organic fibers. In some embodiments, more than 20%, or more than 30%, or more than 40%, or more than 60%, or more than 70%, or more than 80%, or more than 90%, or more than 95% of the body of the pouch may include the pulp or similar substance. In further embodiments, the sealing structure of the pouch also comprises the pulp. In some embodiments, more than 20%, or more than 30%, or more than 40%, or more than 60%, or more than 70%, or more than 80%, or more than 90%, or more than 95% of the sealing structure of the pouch may include the pulp or similar substance.

As used herein, “lignin” is defined as a complex aromatic polymer that comprises about 20% to 40% of wood where it occurs as an amorphous polymer. Lignins can be grouped into three broad classes, including softwood or coniferous (gymnosperm), hardwood (dicotyledonous angiosperm), and grass or annual plant (monocotyledonous angiosperm) lignins. Softwood lignins are often characterized as being derived from coniferyl alcohol or guaiacylpropane (4-hydroxy-3-methoxyphenylpropane) monomers. Hardwood lignins contain polymers of 3,5-dimethoxy-4-hydroxyphenylpropane monomers in addition to the guaiacylpropane monomers. The grass lignins contain polymers of both of these monomers, plus 4-hydroxyphenylpropane monomers. Hardwood lignins are much more heterogeneous in structure from species to species than the softwood lignins when isolated by similar procedures.

Lignin is an organic substance binding the cells, fibers and vessels which constitute wood and the lignified elements of plants, as in straw. After cellulose, lignin is the most abundant renewable carbon source on Earth. Lignin has been shown to function as a plant body’s structural framework or a natural glue holding the cellulosic fibers together and providing rigidity and strength to the plant body structure. Plant fibers can be distinguished from most synthetic fibers by their intricate shape and intrinsic porosity called lumen, which is usually assumed to be tubular. The chemical composition of lignin varies from species to species, but lignin is traditionally considered to be formed from the oxidative coupling of three monolignols: p-coumaryl, coniferyl, and sinapyl alcohols. Between 40 and 50 million tons per annum are produced worldwide as a mostly non commercialized waste product. It is not possible to define the precise structure of lignin as a chemical molecule. All lignins show a certain variation in their chemical composition. However, a commonly used definition is a dendritic network polymer of phenyl propene basic units.

There are two principal categories of lignin: those which are sulfur bearing and those which are sulfur-free. In some embodiments, the lignin category is sulfur bearing. In some embodiments, the lignin category used is sulfur-free. In certain embodiments, the lignin is a mix of sulfur bearing and sulfur-free lignin. These sulfur bearing lignin include lignosulphonates (world annual production of 500,000 tons) and kraft lignin (under 100,000 tons p.a.). Due to the lack of suitable industrial processes, the sulfur-free lignin are not yet widely commercialized.

Unlike synthetic adhesives or plastic coatings, lignin is biodegradable as well as repulpable. When incorporated into the sealing structure, lignin-based materials can assist in ensuring that the entire sealing structure can be recycled at paper mills without disrupting the process. This sustainability feature makes the packaging system more compatible with circular economies, where the goal is to minimize waste and maximize material reuse. In contrast, traditional paper pouch sealing structures made from synthetic adhesives or plastic coatings are often problematic during recycling because these materials are not biodegradable. They may remain in the waste stream, contaminating the recycled paper and making it difficult or impossible to repulp. With lignin, the sealing structure supports zero-waste goals and aligns with sustainable practices in food packaging.

The function of the sealing structure is to secure the pouch and prevent it from falling apart under stress. Lignin, when used in the sealing structure, can offer improved strength and durability, much like synthetic polymers but without the environmental downsides. The adhesive-like properties of lignin allow it to form a strong bond between the paper layers, holding them together effectively. Moreover, lignin's inherent water-insolubility provides added resistance to moisture, making the seal more durable in varying environmental conditions. Lignin's natural properties ensure that the pouch's sealing structure remains intact even when exposed to moderate moisture levels, reducing the likelihood of leaks. This makes it suitable for applications like food packaging where moisture or humidity could compromise the integrity of the pouch. Unlike synthetic adhesives that may lose their effectiveness when exposed to water, lignin retains its functional qualities while also being able to degrade in a controlled recycling process.

As the world shifts toward more sustainable packaging solutions, lignin-based sealing structures and pouches or containers offer an excellent alternative to plastic-based food packaging. Lignin is a natural, renewable resource, unlike petroleum-based plastics. It is produced as a byproduct of the pulp and paper industry, making it readily available and environmentally friendly. By incorporating lignin into the sealing structure and/or body of a pouch or container, the present disclosure provides embodiments that reduce the carbon footprint associated with packaging production. Additionally, since lignin is biodegradable, it does not contribute to long-term environmental pollution when the packaging is discarded.

The present disclosure provides a sustainable solution for the sealing structure and body of the pouches or containers used for food packaging by utilizing lignin as a biodegradable, recyclable, and durable material. By replacing traditional synthetic adhesives or plastic coatings, sealing structures and bodies of the pouch or containers comprising lignin improve the recyclability, support environmentally friendly practices, and can help reduce the carbon footprint of food packaging. With continued innovation and development in lignin processing, this technology could play a significant role in the future of sustainable food packaging.

Other sources of plant-based materials and lignin include, but are not limited to, wood and non-wood plants having sources of cellulose such as soy, rice, cotton, cereal straw, flax, bamboo, reeds, esparto grass, jute, palm fiber, mulberry, coconut husk, agave, reed grass, flax, sisal, abaca, hemp, bagasse, kenaf, Sabai grass, milkweed floss fibers, pineapple leaf fibers, switch grass, lignin-containing plants, and the like. The source of organic fibrous material can be virgin or waste/recycle cellulose fibers, or a combination thereof. In some embodiments, more than 10%, or more than 20%, or more than 30%, or more than 40%, or more than 50%, or more than 60%, or more than 70%, or more than 80%, or more than 85%, or more than 90% of the body of the pouch comprises the organic fibrous material. In further embodiments, the sealing structure of the pouch also comprises the organic fibrous material. In some embodiments, more than 10%, or more than 20%, or more than 30%, or more than 40%, or more than 50%, or more than 60%, or more than 70%, or more than 80%, or more than 85%, or more than 90% of the sealing structure of the pouch comprises the organic fibrous material.

Suitable sources for plant-based materials and lignin may be waste/recycled fiber used as the source of the cellulose fiber, or it may be added to virgin cellulose fibers and in any amount. While any suitable waste/recycled fiber may be used, waste/recycled fiber with relatively low levels of groundwood can be employed in many cases, such as office waste that contains less than 15% by weight lignin content, or less than 10% by weight lignin content. Newsprint waste can contain high quantities of lignin, such as above 10 wt. %, or 20-40 wt. % lignin.

Lignin-based materials have become of interest in sustainable food packaging due to their unique combination of antioxidant and antibacterial properties, alongside their mechanical, thermal, UV-blocking, and antiviral capabilities. These properties make lignin-based materials particularly attractive for the food packaging industry, where extending the shelf life and ensuring the safety of food products are critical.

The exceptional antioxidant activity exhibited by lignin are in part due to the presence of phenolic groups in their structures. These phenolic compounds play a central role in scavenging free radicals, which are reactive molecules that can damage food and packaging materials. The antioxidant activity of lignin is a vital component in preventing the oxidative degradation of food products, which can lead to rancidity, discoloration, and nutrient loss. Additionally, lignin can act as a chain-breaking antioxidant, inhibiting the propagation of free radical chains that could otherwise lead to more extensive oxidation. The antioxidant mechanism can be understood as follows. Lignin's phenolic hydroxyl groups interact with reactive oxygen species, such as hydroxyl radicals, superoxide anions, and peroxyl radicals. These hydroxyl groups donate electrons to neutralize the reactive oxygen species, transforming them into stable, non-reactive molecules and preventing oxidative damage to the food's cellular structures and nutrients.

In addition to its antioxidant properties, the antimicrobial activity of lignin-based materials also makes them highly effective in preventing microbial contamination in food packaging. The antibacterial properties of lignin are attributed to both its physical structure and its chemical composition. Lignin nanoparticles, in particular, have shown promising results in inhibiting the growth of bacteria and fungi. The mechanism of antimicrobial action is thought to involve the interaction of lignin nanoparticles with microbial cell membranes. The hydrophobic nature of lignin and its aromatic structure allow lignin nanoparticles to interact with and disrupt the integrity of the bacterial membrane, leading to leakage of cellular contents and eventually cell death. Lignin’s phenolic groups can also interact with bacterial cell walls, inhibiting important cellular functions, including enzyme activity and DNA replication, further contributing to its antibacterial action. Further, lignin-based materials can be modified to increase their surface area (e.g., in nanoparticle form), enhancing their interaction with microbial surfaces and improving their antimicrobial efficiency.

The combination of antioxidant and antibacterial properties, along with mechanical, thermal, and UV-blocking capabilities, positions lignin-based materials as a sustainable and multifunctional solution for food packaging. These materials can be engineered to address multiple challenges in food preservation, offering enhanced protection from oxidation, microbial contamination, and environmental factors, while also being biodegradable and derived from renewable sources.

The enhanced properties of lignin-based paper pouches make them not only suitable for dry food storage but also highly effective for a wide range of other food occasions that require additional protection and preservation. For example, these pouches are ideal for wet or moist foods, such as fruits, vegetables, or deli items, where antibacterial and antioxidant properties are essential for preventing microbial growth and oxidative spoilage. Lignin-based pouches can also be used for hot food packaging, offering thermal stability to withstand higher temperatures without compromising the structural integrity of the pouch. Additionally, the UV-blocking feature of the material makes it well-suited for packaging foods sensitive to light exposure, such as fresh herbs, dairy products, or juices, where degradation from UV rays can affect quality. Furthermore, the antiviral properties of the lignin-based pouches provide an added layer of safety for ready-to-eat meals and takeout orders, where hygiene and contamination prevention are critical. These advanced features allow lignin-based paper pouches to be used in a broad array of food applications, including wet foods, hot foods, fresh produce, and takeout, expanding their consumer usage beyond traditional dry food packaging.

Lignin has also been effectively integrated into a variety of biopolymers, including starch, protein, cellulose, polylactic acid (PLA), and polyhydroxybutyrate (PHB), to create biopolymers with enhanced functional properties. As a natural, renewable polymer, lignin offers a sustainable alternative to petroleum-based plastics while also improving the mechanical, thermal, and barrier properties of biopolymer materials. When combined with biopolymers such as PLA and PHB, lignin not only reinforces the material's structural integrity but also provides additional anti-oxidant and anti-bacterial properties, making the resulting bioplastics highly suitable for food storage applications. Lignin-enhanced bioplastics can offer superior moisture and gas barriers, which are crucial for extending the shelf life of fresh food products, as well as thermal resistance for handling hot foods or microwave-ready packaging. Furthermore, incorporating lignin into plant-based biopolymers can improve the material's strength and biodegradability, making it an ideal choice for eco-friendly packaging solutions that still meet the stringent demands of food safety, hygiene, and freshness preservation. By enhancing bioplastics with lignin, it is possible to create more sustainable and functional food storage options that reduce environmental impact while ensuring the quality and safety of the food products they contain.

Biopolymers derived from micro- and nano-fibrillated cellulose (MFC and NFC) and regenerated nano-lignin represent an exciting frontier in sustainable packaging materials. These biopolymers are produced by harnessing the unique properties of cellulose and lignin at the nanoscale, allowing for the development of lightweight, strong, and biodegradable polymers that are ideal for food packaging applications. Micro- and nano-fibrillated cellulose (MFC and NFC) are obtained by mechanically or chemically breaking down cellulose fibers into tiny nanoscale structures. This process significantly increases the surface area of the cellulose, improving its mechanical strength, flexibility, and barrier properties. MFC and NFC can be used to create pouches, coatings, and composites that are highly effective at protecting food from moisture, oxygen, and UV radiation, extending the shelf life of food products. These cellulose-based materials are also biodegradable, making them an attractive alternative to conventional plastic packaging.

Similarly, regenerated nano-lignin is produced by breaking down lignin into nanoscale particles or fibers, which are then reconstituted into a usable form for bioplastic production. Nano-lignin has excellent antioxidant and antibacterial properties, which can be leveraged to enhance the functionality of food packaging. When combined with cellulose or other biopolymers, nano-lignin strengthens the material and imparts additional antimicrobial activity, protecting packaged food from spoilage due to bacterial contamination. The incorporation of nano-lignin also improves the thermal stability, UV protection, and mechanical durability of the bioplastic, offering a multi-functional, eco-friendly alternative to synthetic packaging.

Together, nano-cellulose and nano-lignin not only enhance the performance of biopolymers but also contribute to their sustainability by reducing the dependence on petrochemical-based materials used in many modern food packaging materials. These advanced biopolymers are biodegradable and compostable, ensuring that food packaging can break down naturally after use, thus reducing environmental waste. Their high strength-to-weight ratio and multifunctionality make them promising candidates for a wide range of applications in the food packaging industry, offering both environmental benefits and enhanced food preservation. Lignin, as a natural polymer derived from plant biomass, plays a significant role in enhancing the performance and functionality of biopolymers. Due to its unique chemical structure, which includes aromatic rings and phenolic hydroxyl groups, lignin can be used effectively as a plasticizer, stabilizer, or bio-compatibilizer in bioplastic formulations.

In biopolymers, plasticizers are substances that are added to enhance the flexibility and workability of the polymer. Lignin, when incorporated into biopolymer formulations, can act as a plasticizer by reducing the rigidity of the material, making it more flexible and easier to mold or process. This makes lignin an ideal plasticizer for bioplastics made from starch, cellulose, and proteins, which can often be too brittle without modification. By incorporating lignin as a plasticizer, biopolymers become more suitable for applications that require flexibility, such as flexible food packaging films or coatings that need to bend without cracking or breaking.

Lignin can also serve as an excellent stabilizer in biopolymers, particularly in protecting the material from environmental factors such as UV radiation and oxidative degradation. Lignin’s intrinsic antioxidant properties, stemming from its phenolic content, allow it to effectively scavenge free radicals and reactive oxygen species (ROS) that can lead to the breakdown of polymer chains over time. This stabilizing effect is particularly beneficial for biodegradable polymers, which can be more susceptible to degradation compared to traditional plastics. The incorporation of lignin into these materials can extend their lifespan and enhance their thermal stability, UV resistance, and oxidative stability, making them more durable in outdoor or light-exposed environments.

Another important role of lignin in biopolymers is its function as a bio-compatibilizer. In the context of biopolymer blends, particularly those involving natural polymers such as cellulose or PLA (polylactic acid), often the biopolymers have poor compatibility with each other due to differences in their molecular structures, which can lead to phase separation and reduced mechanical properties. As a bio-compatibilizer, lignin can help to form a more homogeneous matrix, enhancing the overall mechanical strength and stability of the biopolymer. This is especially useful when combining lignin with materials like PLA, where lignin can enhance the performance without compromising biodegradability.

By serving as a plasticizer, stabilizer, and bio-compatibilizer, lignin not only improves the mechanical and physical properties of bioplastics but also enhances their sustainability. Unlike synthetic plasticizers and stabilizers, lignin is derived from renewable sources and is inherently biodegradable, making it an ideal choice for the development of eco-friendly packaging materials. The multifunctionality of lignin in biopolymers contributes to the growing demand for sustainable food packaging solutions that offer both performance and environmental benefits. Through the incorporation of lignin, biopolymers can be tailored to meet the diverse requirements of food packaging, providing enhanced flexibility, durability, stability, and biodegradability all in one material.

Recent studies on cellulose-lignin and lignin-containing cellulosic fiber-reinforced bioplastics have focused on overcoming the challenge of low fiber-matrix compatibility in bioplastics. Lignin can act as a compatibilizer improving the adhesion between cellulose fibers and biopolymer matrices, enhancing fiber-matrix interactions. This is achieved by using compatibilizers that modify the surface chemistry of fibers and promote better dispersion. Additionally, crosslinking lignin can improve the mechanical properties and thermal stability of the materials, making them more durable and resistant to degradation. Moreover, controlling the fiber length in cellulose-lignin composites plays a crucial role in optimizing the strength and processing behavior of biopolymers. While shorter fibers offer easier processing, longer fibers provide better reinforcement. These advances help overcome the issues associated with poor dispersion and weak stress transfer in natural fiber-reinforced biopolymers, making the materials stronger and more suitable for food packaging and other applications.

Lignin is inherently hydrophobic. This low affinity for water and inability to easily absorb moisture is crucial in the context of food packaging, as it helps to minimize localized condensation within the packaging material. When food is stored in pouches or containers, especially in environments with fluctuating temperatures or humidity levels, condensation can occur inside the packaging. This moisture can create an ideal environment for the growth of microorganisms like bacteria and mold, which can accelerate food spoilage and reduce the shelf life of the product. Because of its hydrophobic nature, lignin acts as a moisture barrier, preventing the absorption of water and the formation of condensation on the inside of the packaging. This is particularly important for fresh food storage, as it helps to maintain a dry and stable environment, reducing the risk of moisture-related degradation. For example, when storing fruits, vegetables, or baked goods, lignin-based packaging can help maintain crispness, texture, and flavor, preventing the deterioration that often results from excess moisture accumulation. Additionally, by keeping condensation at bay, lignin-based materials help to preserve the freshness of the product for a longer period, thereby extending the shelf life and reducing food waste.

In some embodiments, the pouch, body, and/or the sealing structure may be repulpable, recyclable, or repulpable and recyclable. Further, one or more adhesives may be used along the pouch and/or the sealing profile, which may also be repulpable, recyclable, or repulpable and recyclable. In some embodiments, the pouch may be customized by printing one or more indicia on one or both of the first and second opposing walls at predetermined intervals. Indicia may include, e.g., logos, writable surfaces, volumetric fill lines or other indicators, etc. Indicia may be applied at various stages during the manufacturing process. In still another aspect, indicia may not be applied to the pouch. In yet another aspect, customizing may include adding sliders, stickers, embossing, scoring, or other decorative and/or functional attributes to the pouch.

In some embodiments, the pouch may include a fold top closure, a slider sealer, a hook-and-loop-type sealer, or an adhesive to at least partially seal a mouth of the pouch. In some embodiments, a tab disposed adjacent the mouth may assist in opening the pouch. Additionally, as would be appreciated by those of ordinary skill in the pertinent art, the subject technology is applicable to any type of bag, pouch, package, and various other storage containers, e.g., snack, sandwich, quart, and gallon size bags. The subject technology is also adaptable to pouches having a double zipper, multiple zippers, or other type of closure mechanisms.

In some embodiments, the ratio of fiber to another material may be 85% fiber compared with 15% of a different material, which achieves a repulpable material. In some embodiments, more than 90% fiber may be utilized, which renders the pouch recyclable. A repulpable formulation for the pouches disclosed herein may include a blend of lignin, a water-insoluble polymer and repulpable, plant-based materials. In some embodiments, the lignin acts as a binder of the repulpable, plant-based cellulosic material to maintain structural integrity of the zipper closure during use, and further enables the repulpability and recyclability of the packaging structure. As noted above, a formulation range of 15% or less of the water-insoluble polymer and/or lignin enables ease of repulpability and maintains recyclability with current recycling streams, which require 85% recovered repulpability. However, use of more than 90% plant-based material increases recyclability and composability of the product, due to the higher ratio of fiber content to polymer.

The closure elements disclosed herein can include any suitable water-insoluble polymer that is not miscible with water or aqueous liquids. When present, the closure element can be formed using the same water-insoluble polymer as the remainder of the pouch or can be formed using a different water-insoluble polymer. Suitable repulpable materials include plant-based cellulose materials, including wood pulp, paper fibers, cotton, linen, silk, wool, combinations thereof, and/or any of the plant-based materials listed above. While other (e.g., non-cellulose) materials may qualify as repulpable, the plant-based cellulose materials, combined with suitable amounts of a water-insoluble polymer, contribute mechanical and structural properties that are helpful in some embodiments to maintain the structural integrity of the closure element.

To that end, the materials used to form the pouches, bodies, and sealing structures may fall into the same two categories. The first category includes lignin and other water-insoluble polymers that are not miscible in water. The second category includes repulpable and recyclable materials, such as plant-based cellulose materials that are intended to replace disposable non-repulpable/recyclable plastic packages. The pouches disclosed herein can include between about 5% and about 95% by weight of a water-insoluble polymer and between about 5% and about 95% by weight of a repulpable and/or recyclable material. In some embodiments, the pouch, body, and/or sealing structure can include between about 10% and about 90% by weight of a water-insoluble polymer and between about 10% and about 90% by weight of a repulpable and/or recyclable material, or between about 15% and about 85% by weight of a water-insoluble polymer and between about 15% and about 85% by weight of a repulpable and/or recyclable material. In embodiments that includes a zipper, the zipper is movable between a first open position that disengages the at least one interlocking element adapted for connection to the front wall from the at least one interlocking element adapted for connection to the second wall and a second closed position that engages the at least one interlocking element adapted for connection to the front wall to the at least one interlocking element adapted for connection to the second wall.

The polymers, besides lignin, may include any polymer combinations that are useful, including polyolefins, hexanes, poly(lactic acid)s, polyhydroxyalkanoates, chitosans, polyimides, polysiloxanes, acrylic polymers, polybenzoxazines, polyvinyl acetates, polyethylenes, polystyrenes, polyvinyl acetate copolymers, polyacrylates, polyethers, styrene-maleic anhydrides and combinations thereof. In some embodiments, the water-insoluble polymer used to form the body of the pouch (i.e., the front wall and the back wall thereof) can be the same water-insoluble polymer or polymer combination used to form the one or more closure elements or can be a different water-insoluble polymer or polymer combination.

Polyolefins refer to a group of polymers derived from olefins (alkenes), including polyethylene (PE) and polypropylene (PP). Polyethylene is widely used and available in several forms, including low-density polyethylene (LDPE), high-density polyethylene (HDPE), and ultra-high-molecular-weight polyethylene (UHMWPE), each with distinct properties like flexibility, strength, and chemical resistance. Polyolefins have been used in products from plastic pouches to industrial pipes.

Hexanes refer to hydrocarbons that contain six carbon atoms (C₆H₁₄). Hydrocarbons are saturated compounds made up only of carbon and hydrogen atoms. The straight-chain form, n-hexane, is the most common form found in hexane solvent mixtures, though the mixture can contain branched isomers including but not limited to isohexane and neopentane. These isomers have the same molecular formula but differ in the arrangement of their carbon atoms, which affects their boiling points and solvent properties. Hexanes can be derived from crude oil and are often used for cleaning, extracting, and purifying other polymer materials in industrial settings.

Poly(lactic acid) (PLA) refers to biodegradable and bioactive thermoplastic polyester derived. PLA can be derived from renewable resources like corn starch or sugarcane. PLA is made in varying grades such as amorphous PLA, crystalline PLA, high molecular weight PLA, low molecular weight PLA, plasticized PLA, and blended PLA. These grades are typically classified based on their intended use which includes uses such as biodegradable packaging, fibers, and medical sutures, with properties influenced by factors like molecular weight and polymerization method.

Chitosan refers to a biopolymer derived from chitin, generally found in the shells of crustaceans. Chitosan derivatives can include N-acyl chitosans for different biomedical applications, and modified forms are used in food preservation due to its antimicrobial properties.

Polyimides refer to a group of polymers with a distinctive structure with imide groups (–C(=O)–N–C(=O)–) in their polymer main chain. These can be synthesized from different diamines and dianhydrides, with variations like PMDA-ODA (polyamide-imide).

Polysiloxanes (silicones) refer to a group of polymers with a polymer main chain composed of alternating silicon and oxygen atoms. Silicones can be crosslinked to form elastomers, or processed into liquids and gels for use in a wide range of applications, including offering flexibility, water resistance, and high thermal stability for food packaging.

Acrylic polymers refer to a group of polymers made from acrylic. The monomers are derived from acrylic acid or its derivatives like methacrylic acid. Acrylic polymers can also be copolymerized with comonomers including butyl acrylate or styrene to improve impact resistance and flexibility. Exemplary acrylic polymers include poly(methyl methacrylate) (PMMA), also known as acrylic glass or Plexiglas®, and other copolymers made by combining different acrylic monomers. These polymers can be flexible or rigid depending on their formulation and are used for their optical clarity, UV stability, and resistance to weathering.

Polybenzoxazines refer to a group of thermosetting polymers derived from benzoxazine monomers. These polymers are known for their high thermal stability and excellent mechanical properties. Polybenzoxazines may be synthesized via condensation reactions involving phenolic resins and amine-based monomers and are used in high-performance composites.

Polyvinyl acetates (PVAc) refer to polymers derived from vinyl acetate monomer. These polymers are commonly used in adhesives, paints, and coatings due to their film-forming properties. PVAc variants, such as polyvinyl acetate emulsions, are used in wood adhesives and paper coatings.

Polystyrene (PS) refers to a polymer derived from monomers of the aromatic hydrocarbon styrene. Polystyrene is a versatile thermoplastic polymer often used for disposable items like cutlery, containers, and packaging. Polystyrene can be expanded (EPS) to create lightweight foam products or crystal (rigid) for transparent applications, depending on the processing method.

Polyvinyl acetate copolymers refer to a group of copolymers made by combining polyvinyl acetate with other monomers. The inclusion of monomers like ethylene or acrylic acid can modify the properties, making them suitable for adhesives, paints, coatings, and emulsions with enhanced water resistance and durability.

Polyacrylates refer to a group of polymers derived from acrylic acid or acrylate esters. These monomers often include compounds like methyl acrylate, ethyl acrylate, butyl acrylate, and other acrylate esters. Polyacrylates are commonly used in applications requiring flexibility, adhesion, and water resistance.

Polyethers refer to polymers characterized by repeating ether linkages (–O–) in their main chain. These polymers can be formed through the polymerization of monomers containing ether groups, such as ethylene oxide or tetrahydrofuran (THF). These polymers can also be blended with other polymers including polyurethane to creating flexible foams or block copolymers.

Styrene-maleic anhydride copolymers refer to polymers that combine styrene and maleic anhydride and are used in engineering plastics, adhesives, and coatings. Styrene-maleic anhydride copolymers can be modified with glycol or amide groups to improve their performance in specific applications.

Lignin can also be combined with bio-oils, like castor oil, to produce a biodegradable polymer. Lignin, with its natural structure and high phenolic content, can be used as a reinforcing agent or cross-linking component in the formation of biopolymers when blended with castor oil, which provides flexibility and hydrophobic characteristics due to its fatty acid content. Castor oil, known for its renewable, biodegradable, and non-toxic properties, can act as a plasticizer, enhancing the workability and durability of the resulting polymer. This combination leverages the natural, sustainable sources of both lignin and castor oil, offering a promising alternative to traditional petroleum-based plastics. In addition to castor oil, several other vegetable oils and bio-based oils can be combined with lignin to produce biodegradable polymers. These oils can provide varying degrees of flexibility, strength, and biodegradability depending on their chemical structure. These bio-oils are made up of fatty acids selected from ricinoleic acid, oleic acid, linoleic acid, palmitic acid, stearic acid, lauric acid, myristic acid, caprylic acid, capric acid, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

The body of the pouch, in some embodiments, can be made 100% non-petroleum-based plastic by using lignin as an eco-friendly alternative to traditional plastic-based bodies. Lignin can be processed and modified to create strong, durable, and biodegradable materials suitable for food packaging. When combined with other renewable resources like plant oils or natural fibers, lignin-based materials can form robust, water-resistant, and flexible bodies that are completely free of synthetic plastics. By harnessing lignin’s natural adhesive properties, the body can perform efficiently without relying on petroleum-based materials, offering both functional and environmental benefits. In further embodiments, the body of the pouch can also be made of 100% non-petroleum-based plastic.

The process of incorporating lignin into the sealing structure and/or body of the pouches can include lignin being processed using a variety of methods, including coating, extrusion, or lamination. For coating, a thin layer of lignin can be applied to the edges of the pouch using a spraying or dipping technique. The lignin then dries to form a durable, water-insoluble barrier. In any of these processes, lignin can be blended with other eco-friendly compounds (such as water-insoluble polymers) to enhance its adhesion properties and to ensure that the sealing structure and/or body of the pouch can withstand the pressures of daily use, including weight-bearing and external impacts.

In some embodiments, the method of making a plant-based pouch, body, and/or sealing structure for food packaging includes blending regular paper with kitchen oil (or frying oil) or other oils containing fatty acids. The mix may then be heated and pushed through the extruder. In some embodiments, the lignin of the paper is heated beyond the melting temperature of the lignin and when cooled off acts as the bind for the extrudate. In some embodiments, the lignin or other water-insoluble polymer acts as a binder of the plant-based cellulosic material, to maintain structural integrity and functionality of the sealing structure when exposed to water-based food, such as soups, pastas, watery produce, etc.

Maintaining functionality and structural integrity during water-based food storage has been of particular interest for plant-based pouches and closure elements. The temperature of the water-based food, especially heat, can often damage the structural integrity of plant-based pouches, bodies, and sealing structures, and therefore using strong plant-based materials is of particular interest to improve heat resistance. In some embodiments, the temperature of the water-based food varies from a range of -20° F (-29° C) to 212° F (100° C) while maintaining structural integrity and functionality of the sealing structure, body, and pouch. In some embodiments, the end pulp/binder mixture is configured to be heat resistant up to 451° F (232° C), freezer capable, and oven and microwave resistant. Preferably, the pulp/binder mixture in its end form is water and oil resistant. In some embodiments, the zipper 124 is separately combined with and/or joined to a paper pouch to make a fully recyclable paper pouch product.

With reference to FIGS. 1 and 2, one particular embodiment of a pouch 100 in the form of a pouch is illustrated, which includes a closure system 102 in the form of an origami over center hinge, which defines a first sealing structure 104. While it is contemplated that the closure systems disclosed herein may be applied to any of a bag, a pouch, or a container, for ease of reference only the pouch 100 is discussed hereinafter. Further, any of the closure systems of the embodiments discussed herein may be applied to or made integrally with the pouch 100 shown in FIGS. 1 and 2. In some embodiments, the pouch 100 may or may not include a closure system having one or more closure elements 106. In some embodiments, a pouch includes the following elements: a front wall 108 and a back wall 110, each of which defines a first side 112 (i.e., left edge), a second side 114 (i.e., right edge), a top 116, and a bottom 118.

The front wall 108 and the back wall 110 are joined together at the respective first sides 112, second sides 114, and bottoms 118. Each of the respective joinders can be a fold (if the front and back walls are continuous), or a heat seal, or any suitable joint that is essentially permanent and cannot be opened and re-closed. A re-closeable mouth 120 is defined by the top 116 of the front wall 108 and the top 116 of the back wall 110. In some embodiments, the pouch 100 may be a zippered pouch, a slider pouch, a drawstring pouch, or any other type of pouch that is unsealable, sealable, and/or resealable. Further, pouches may broadly encompass any type of component made from a repulpable and/or recyclable material for use by a consumer or industrial user. Various embodiments of pouches and closure systems are depicted herein; however, one of ordinary skill will understand that the presently disclosed system and method may encompass other containers and pouches as noted herein, and that various embodiments may be combined with other embodiments to achieve an optimal solution.

Still referring to FIGS. 1 and 2, the re-closable pouch 100 in the form of a pouch is shown to include a body made up of the front wall 108 and the back wall 110, which are joined together at the respective first side 112, second side 114, and bottom 118, and the closure system 102, as disclosed herein. The pouch 100 in pouch form may be entirely made of one or more repulpable and/or recyclable materials, as described above. When the pouch 100 as a pouch is formed as a unitary component, leak paths along edges of the pouch 100, e.g., the left edge 112, the right edge 114, and the bottom edge 118, are minimized or eliminated since no additional sealing is required along the various edges or sides of the pouch 100, in contrast to some prior art pouches.

The respective tops 116 of the front wall 108 and back wall 110, define the mouth 120, which can be opened and closed using a sealing structure 104, which may be a zipper that is defined by interlocking elements that are connected to and/or adjacent to the tops 116 of the respective front and back walls. As shown in FIG. 3 for example, the zipper 124 includes at least one (or more than one) first interlocking element 126 connected to the front wall 108 and at least one (or more than one) second interlocking element 128 connected to the back wall (not shown) of the flexible pouch 100. In such an embodiment, the zipper 124 is movable between a first open position that disengages each of the first interlocking elements 126 from each of the second interlocking elements 128 and a second closed position that engages each of the first interlocking elements 126 to each of the respective second interlocking elements 128.

Referring again to FIG. 2, a schematic view is shown of the pouch of FIG. 1 with the first sealing structure 104 shown in a closed configuration. In the present embodiment, the first sealing structure 104 includes a first flap 130 (see FIG. 1) that is configured to be folded over a fold line 132 (see FIG. 1) to achieve the folded configuration shown in FIG. 2. Additional features, such as an adhesive (not shown) may be applied to the first flap 130, which may aid in retaining the first flap 130 to the body of the pouch 100. In some embodiments, multiple flaps may be provided, which may further aid in sealing the pouch 100 to achieve the sealed configuration shown in FIG. 2 to enclose an interior volume thereof. In some embodiments, the pouch 100 is leakproof, and in other embodiments, the pouch 100 is not leakproof. In some embodiments, adhesives and cohesives used for in the sealing structure may be selected from mucilage adhesives, cement adhesives (i.e., contact cement and rubber-based adhesives, including both natural and synthetic rubber), biopolymer-based adhesives (i.e., itaconic acid), soy protein adhesives, casein adhesives, hot melt adhesives (i.e., thermoplastic adhesives that are applied using heat), pressure sensitive adhesives (i.e., adhesives that are bonded using pressure), thermoset adhesives, glycoprotein adhesives, multipart adhesives, UV curing adhesives, cyanoacrylate adhesives (i.e., super glue), synthetic adhesives (i.e., PVA, PVAc, VAE, etc.), and combinations thereof.

Referring now to FIG. 3, a side cross-sectional view is shown of a second sealing structure 134 including a first or male portion 136 and a second or female portion 138 shown in an open configuration. The male portion 136 includes a stem 140 from which a head 142 extends, the head 142 defining a generally triangular configuration. The female portion 138 comprises a base portion 144, a first or upper arm 146, and a second or lower arm 148 that are spaced apart from one another and extend toward one another from the base portion 144. The female portion 138 further defines a cavity 150 with rounded inner fillets 152 and a bulbous innermost area 154, which is configured to receive the male portion. The female portion 138 is symmetric about a longitudinal center plane or centerline 156; however, alternative a-symmetric embodiments are contemplated. The upper arm 146 and the lower arm 148 are integral with the base 144 and extend therefrom. The upper arm 146 and the lower arm 148 define an opening into the cavity 150, into which the head 142 of the male portion 136 is inserted to seal the pouch 100. The opening of the cavity 150 is defined between distal ends of the upper arm 146 and the lower arm 148. The upper arm 146 and the lower arm 148 are capable of deflecting inward or outward when the head 142 of the male portion 136 is inserted into or removed from the cavity 150.

Still referring to FIG. 3, the female portion 138 further defines a height 158 and a thickness 160, the cavity 150 defines a height 162 and a thickness 164, and the opening of the cavity 150 defines a height 166. The base portion 144 includes an inner portion 168 and an outer portion 170. The inner portion 168 is defined by a vertical line or plane that extends perpendicularly through the longitudinal centerline 172 and through an innermost point 174 along the surface defining the cavity 150. As such, the inner portion 168 includes the entire cavity 150, while the outer portion 170 does not include any portion of the cavity 150. The inner portion 168 further defines a thickness 176, which is measured in a direction parallel with respect to the centerline 172, and the outer portion 170 defines a thickness 178 measured in a direction parallel with respect to the centerline 172.

The male portion 136 of the second closure system 134 is also shown in FIG. 3, which includes the stem portion 140 that extends outward from a base portion 180 and joins the head 142. The head 142 defines an outer corner 182 and inner rounds 184 that are disposed in a triangular configuration. The head portion 142 and the stem 140 are unitary components with the male base portion 180. The base portion 180 of the male portion 136 defines a height 186 and a thickness 188, and the male portion 136 defines a thickness 190. The cavity 150 of the female portion 138 is defined by an inner surface 192. The male profile 136 is defined by an outer surface 194 that corresponds to its profile. As shown in FIG. 3, the outer surface 194 of the male portion 136 does not follow a profile of the inner surface 192 of the female portion 138. In the present embodiments, surfaces that do not follow a corresponding profile portion can be considered to have different shapes or curvatures defining the respective surfaces, i.e., they do not mirror one another or have profiles that substantially conform with one another. Non-identical profiles may be selected to provide performance benefits, such as improved vacuum sealing. In other embodiments, the surfaces may follow a corresponding profile portion having identical or substantially conforming profiles. In some embodiments, the male portion 136 and the female portion 138 combine to define a sealing structure that is a zipper having a water-insoluble polymer component, that may be coupled with the pouch 100 or made as an integral component thereof. In some embodiments, the male portion 136 and the female portion 138 are positioned at the top of the front wall 108 and the top of the back wall 110. The second sealing structure 134 is movable between a first open position that disengages the male portion 136 from the female portion 138, and a closed position.

In some embodiments, the bodies of the pouches disclosed herein include between about 1% and about 99% by weight, or between about 3% and about 97% by weight, or between about 6% and about 94% by weight, or between about 9% and about 91% by weight, or between about 12% and about 88% by weight, or between about 15% and about 85% by weight, or between about 20% and about 80% by weight, or between about 25% and about 75% by weight, or between about 30% and about 70% by weight of a water-insoluble polymer, besides lignin, and between about 1% and about 99% by weight, or between about 3% and about 97% by weight, or between about 6% and about 94% by weight, or between about 9% and about 91% by weight, or between about 12% and about 88% by weight, or between about 15% and about 85% by weight, or between about 20% and about 80% by weight, or between about 25% and about 75% by weight, or between about 30% and about 70% by weight of a repulpable, plant-based material.

In further embodiments, the sealing structures of the pouches disclosed herein include between about 1% and about 99% by weight, or between about 3% and about 97% by weight, or between about 6% and about 94% by weight, or between about 9% and about 91% by weight, or between about 12% and about 88% by weight, or between about 15% and about 85% by weight, or between about 20% and about 80% by weight, or between about 25% and about 75% by weight, or between about 30% and about 70% by weight of a water-insoluble polymer, besides lignin, and between about 1% and about 99% by weight, or between about 3% and about 97% by weight, or between about 6% and about 94% by weight, or between about 9% and about 91% by weight, or between about 12% and about 88% by weight, or between about 15% and about 85% by weight, or between about 20% and about 80% by weight, or between about 25% and about 75% by weight, or between about 30% and about 70% by weight of a repulpable, plant-based material.

In some embodiments, more than 10%, or more than 20%, or more than 25%, or more than 30%, or more than 40%, or more than 50%, or more than 60%, or more than 70%, or more than 75%, or more than 80%, or more than 85%, or more than 90% of the body of the pouch includes the lignin. In further embodiments, more than 10%, or more than 20%, or more than 25%, or more than 30%, or more than 40%, or more than 50%, or more than 60%, or more than 70%, or more than 75%, or more than 80%, or more than 85%, or more than 90% of the sealing structure of the pouch includes the lignin. In some embodiments, the body disclosed includes about 100% lignin. In further embodiments, the sealing structure disclosed herein includes about 100% lignin.

In some embodiments, the lignin of the body of the pouch includes a nano-lignin. In some embodiments, at least 5%, or at least 10%, or at least 20%, or at least 25%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95% of the body of the pouch comprises the nano-lignin. In further embodiments, the lignin of the sealing structure of the pouch includes a nano-lignin. In other embodiments, at least 5%, or at least 10%, or at least 20%, or at least 25%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95% of the sealing structure of the pouch includes the nano-lignin.

In some embodiments, the pouch 100 disclosed herein includes between about 1% and about 99% by weight, or between about 3% and about 97% by weight, or between about 6% and about 94% by weight, or between about 9% and about 91% by weight, or between about 12% and about 88% by weight, or between about 15% and about 85% by weight, or between about 20% and about 80% by weight, or between about 25% and about 75% by weight, or between about 30% and about 70% by weight of a water-insoluble polymer, besides lignin, and between about 1% and about 99% by weight, or between about 3% and about 97% by weight, or between about 6% and about 94% by weight, or between about 9% and about 91% by weight, or between about 12% and about 88% by weight, or between about 15% and about 85% by weight, or between about 20% and about 80% by weight, or between about 25% and about 75% by weight, or between about 30% and about 70% by weight of a repulpable, plant-based material.

Referring now to FIG. 4, an exemplary figure of a female portion of a zipper is shown. This female zipper portion shown in FIG. 4 was produced via blending regular paper with water-insoluble kitchen oil (or frying oil). The blend was then heated and pushed through an extruder to produce the female zipper portion where the fibers are held together but no binder was added. The lignin of the paper is heated beyond the melting temperature of the lignin and when cooled off the lignin acts as a binder for the extrudate. In some experiments, during the heating process, the blend is heated to a temperature of at least 284° F (284° C) or 320° F (160° C) to ensure the temperature of the blend is at least the melting point and flow of lignin. After the lignin is melted and pressurized to flow through a mold or an extruder, the molten lignin mixes with the fibers of the blend. This process of mixing strengthens the blend and allows the blend to hold the pressures of a pouch closure.

It is intended that the thin-thin-thin cross-hatching disclosed herein is inclusive of the materials disclosed herein, such as paper, repulpable materials, lignin, plant-based cellulose materials, polymers, binders, etc.

Additionally, as would be appreciated by those of ordinary skill in the pertinent art, the subject technology is applicable to any type of bag, pouch, package, and various other storage containers, e.g., snack, sandwich, quart, and gallon size bags. The subject technology is also adaptable to bags having double zippers, or multiple zippers, or other type of closure mechanisms.

Industrial Applicability

Numerous modifications will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention. The exclusive rights to all modifications which come within the scope of the application are reserved. All patents and publications are incorporated by reference herein in their entirety.