Packaging Materials

Abstract

A packaging material comprising a substrate and a liner extending along the substrate, the liner comprising at least a biopolymer and graphene nanoplatelets, the liner providing a gas barrier along at least a portion of the packaging material.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 288,218, filed December 10, 2021. [Incorporated by reference]

[0002] The disclosure of U.S. Provisional Patent Application No. 63 / 288,218, filed December 10, 2021, is hereby incorporated by reference for all purposes as if set forth herein in its entirety. [Background technology]

[0003] FIELD OF THE DISCLOSURE This disclosure relates generally to materials (eg, laminates) for forming packaging components. Summary of the Invention

[0004] In one aspect, the present disclosure generally relates to a packaging material that includes a substrate and a liner extending along the substrate, the liner including at least a biopolymer and graphene nanoplatelets to provide a gas barrier along at least a portion of the packaging material.

[0005] In another aspect, the present disclosure generally relates to a method of forming a packaging material, the method can include forming a liner material by incorporating graphene nanoplatelets into a biopolymer, the method can further include applying the liner material to a substrate, such that the liner material provides a gas barrier along at least a portion of the packaging material.

[0006] In yet another aspect, the present disclosure generally relates to an article of manufacture that includes a packaging material. The packaging material can include a substrate and a liner extending along the substrate. The liner can include at least a biopolymer and graphene nanoplatelets to provide a gas barrier along at least a portion of the packaging material.

[0007] Other aspects, features, and details of the present disclosure can be more fully understood from the appended claims by reference to the following detailed description of exemplary embodiments in conjunction with the drawings.

[0008] Those skilled in the art will appreciate these and other advantages and benefits of various additional embodiments upon reading the following detailed description of the exemplary embodiments with reference to the following drawings: In addition, the various features of the drawings described below are not necessarily drawn to scale. Dimensions of various features and elements in the drawings may be expanded or reduced to more clearly illustrate the exemplary embodiments of the present disclosure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates a portion of an exemplary packaging material according to the present disclosure.

[0010] Corresponding parts are indicated by corresponding reference numbers throughout the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present disclosure generally relates to packaging materials including laminates. The packaging materials can be for forming components (e.g., containers, packages, sleeve cases, trays, cups, insulating cups, or other components). In some embodiments, the packaging materials can include other materials in addition to the laminates (e.g., injection molded polymeric elements). The components can be used, for example, to hold, store, freeze, heat, cook, etc. food products or other products. In one example, the components can be configured to hold food products while heating in a microwave oven, an electric oven, or both (e.g., dual oven heating), hermetically seal (e.g., extended life with atmosphere packaging, vacuum sealed packaging, etc.), refrigerate / freeze, and / or serve food (e.g., french fries). Additionally, the packaging materials and / or components made from the packaging materials can include microwave packaging elements (e.g., microwave energy interactive elements such as microwave susceptor elements, microwave shielding elements, etc.), and / or seals configured to automatically vent during heating or transportation at elevated temperatures. Other uses and formats of composite components are also included in the present disclosure.

[0012] In this embodiment, the materials of the packaging material elements can include renewable materials, natural fibers, repulpable materials, and / or degradable materials. For example, the renewable materials can be derived at least in part from biological processes or other processes whose supplies can be replenished within a reasonable period of time, which can include annually renewable plant sources, plant sources that can be replenished in years or decades, algae, bacteria, or any other suitable source. In one example, the reasonable period for at least partially replenishing the resources can be within the lifespan of an average person. For example, a polymer derived exclusively from fossil-derived petrochemicals may not be considered a biobased polymer. However, some substances similar to petrochemicals (e.g., petrochemical analogs) can be produced at least in part by microorganisms and / or other biological sources, or by, for example, chemically reacting or modifying biologically-sourced materials, and these at least in part biobased petrochemical analogs can be used to produce at least in part biobased polymers. A natural fiber can be any fiber that occurs at least partially in nature, such as fibers derived from plants (e.g., wood fibers, cotton, hemp, jute, flax, coconut fiber, bamboo, sugar cane, rice husk, banana fiber, jute, sisal, and other plants). A repulpable material (such as a paper product) can be a material that can be returned to a pulp (e.g., by chemical, mechanical, and / or other suitable methods) to produce new materials from the pulp (such as recycled paper). A degradable material (e.g., polylactic acid-based polymers) can be at least partially compostable biodegradable materials and / or other materials that can be broken down within a reasonable time at least partially into smaller elements that are relatively harmless to the environment and / or nutrient (e.g., for beneficial plants and / or bacteria).

[0013] According to one embodiment, the renewable and / or degradable materials can include bio-based polymers ("biopolymers"), polymers formed at least in part from chemicals produced or extracted from living organisms (e.g., plants, algae, bacteria, animals), paper products, and / or other materials. Paperboard and other paper products are often recognized as inherently sustainable or renewable materials because the trees and other plants that provide the raw materials for paper products can and are periodically replanted in a sustainable and renewable manner. In one embodiment, the renewable and / or degradable materials can be processed in injection molding applications, can be bonded or otherwise applied to substrates (e.g., raw materials or pressed trays), have sealing, barrier and / or breathability properties, and / or have temperature resistance to heating (e.g., microwave ovens and / or electric ovens) and / or refrigeration / freezing or other storage. Other renewable and / or degradable materials can also be used without departing from this disclosure.

[0014] The materials of the packaging material can have properties suitable for the particular type of component made from the packaging material. For example, a component that is a tray or other container for holding or serving food products can include a barrier layer that is permeable or impermeable to certain gases, liquids, and / or other flowable materials (e.g., oil, oxygen, water, etc.). Because it is often recommended that many food products be heated to at least about 165° F., a component for heating food products can include renewable materials that have a heat resistance of at least about 165° F. Applications with lower temperature resistance requirements can include, for example, heating non-food products, heating beverages, reheating some foods, applications requiring only storage and / or cooling, and / or other suitable applications. Some applications may have higher temperature resistance requirements, for example, for food products that require a higher external temperature to reach a minimum internal temperature and / or for at least partially heating the food products in an electric oven that may be set at a higher temperature to heat the food products via conduction and / or convection. Other considerations for selecting an appropriate material may include material strength to support the mass of the product and / or for stacking.

[0015] In this embodiment, the packaging material can include a laminate 100 as shown in FIG. 1. The laminate can include a substrate 102 and a film, coating, or liner 104 applied (e.g., glued, heat sealed, and / or otherwise attached) to the substrate 102. The substrate 102 can be a paper product (e.g., paper, paperboard, cardboard, and / or other suitable fibrous and / or non-fibrous materials), other renewable, degradable, compostable, and / or rechargeable suitable materials, and / or any other suitable materials. In one embodiment, the liner 104 can include a subset of bioplastics and biopolymers known as polyhydroxyalkanoates (PHAs) in combination with graphene nanoplatelets 106. In an exemplary embodiment, the graphene nanoplatelets can be a form of graphene. Graphene is an extremely thin form of carbon with atoms arranged in a flat two-dimensional lattice. In an exemplary embodiment, graphene can have exceptional electrical, mechanical, and / or thermal properties, and graphene is being investigated for a wide range of applications. Graphene nanoplatelets (GNPs) are short stacks of graphene having a platelet shape and are available in various stages, for example, short stacks can include layers of graphene stacked to a height that is less than the length and / or width of the layers.

[0016] In an embodiment, the laminate 100 can provide a sustainable functional biopolymer nanocomposite from renewable resources with gas and / or water barrier for packaging. In an alternative embodiment, polyhydroxyalkanoate (PHA) can be replaced with other biomaterials such as polylactic acid (PLA) and / or polybutylene succinate (PBS).

[0017] In an embodiment, the liner 104 can be formed by incorporating graphene nanoplatelets into a polyhydroxyalkanoic acid. The polyhydroxyalkanoic acid with graphene nanoplatelets can provide barrier properties to water and / or gases (e.g., oxygen, carbon dioxide, nitrogen, etc.). In an exemplary embodiment, the liner material can be formed by melt mixing the graphene nanoplatelets with a biopolymer (e.g., polyhydroxyalkanoic acid) and / or by other suitable methods. The liner material can then be applied to the substrate 102 (e.g., by flexo / gravure printing, flood coating, extrusion coating, and / or other suitable processes) to form the laminate 100 such that the liner 104 forms a gas and / or water barrier on the substrate. In an embodiment, the graphene nanoplatelets can be prepared in an aqueous solution, and dispersants (e.g., graphene oxide, ethanol, isopropyl alcohol, calcium stearate, etc.), electrostatic systems, etc. can be used to help reduce or prevent agglomeration of the graphene nanoplatelets. The coating can be formed on the substrate, for example, by applying the aqueous solution to the substrate in a drawdown process.

[0018] In an exemplary embodiment, polyhydroxyalkanoates or other biopolymers and graphene nanoplatelets can be combined in appropriate amounts such that the graphene nanoplatelets are randomly dispersed in the material and agglomeration of the graphene nanoparticles is avoided. In an embodiment, factors such as the polymer used, the method of combining the polymer with the graphene nanoplatelets, the amount of graphene nanoplatelets incorporated into the polymer, and / or other factors can affect the amount of graphene nanoparticle aggregation in the coating. For example, certain composites can show improved material properties (e.g., low graphene nanoparticle aggregation) at loadings of about 4% or about 5% by weight (e.g., LLDPE and PLA), under which loadings can reduce aggregation and increase material properties (e.g., tensile strength) with increased mixing (e.g., high screw speed), while higher loadings (e.g., about 10% by weight) can be more difficult to handle at the mixing speed and result in more aggregation. In embodiments, the coatings of the present application may include graphene nanoparticles in an amount of about 10% by weight or less, about 9% by weight or less, about 8% by weight or less, about 7% by weight or less, about 6% by weight or less, about 5% by weight or less, about 4% by weight or less, about 3% by weight or less, about 2% by weight or less, about 1% by weight or less, about 0.5% by weight or less, or other suitable amounts. In additional embodiments, the coatings may include graphene nanoparticles in an amount of about 1% to about 10% by weight, about 2% to about 10% by weight, about 3% to about 10% by weight, about 4% to about 10% by weight, about 5% to about 10% by weight, about 6% to about 10% by weight, about 7% to about 10% by weight, about 8% to about 10% by weight, about 9% to about 10% by weight, about 1% to about 7% by weight, about 2% to about 7% by weight, about 3% to about 7% by weight, It may be about 3% by weight to about 7% by weight, about 4% by weight to about 7% by weight, about 5% by weight to about 7% by weight, about 6% by weight to about 7% by weight, about 1% by weight to about 5% by weight, about 2% by weight to about 5% by weight, about 3% by weight to about 5% by weight, about 4% by weight to about 5% by weight, about 1% by weight to about 4% by weight, about 2% by weight to about 4% by weight, about 3% by weight to about 4% by weight, about 1% by weight to about 3% by weight, about 2% by weight to about 3% by weight, about 1% by weight to about 2% by weight, or any other suitable amount.

[0019] In embodiments, polyhydroxyalkanoates are sourced from renewable resources, including by bacterial fermentation of sugars and lipids. Composites of such materials with graphene nanoplatelets can form gas barriers, such as oxygen and / or carbon dioxide barriers, and can help preserve and maintain the quality of food products and other items. In exemplary embodiments, graphene nanoplatelets can improve the gas barrier properties of biopolymers (e.g., polyhydroxyalkanoates) through a mechanism related to factors including that the presence of dispersed graphene nanoplatelets in the polymer can increase the pathways for diffusing molecules through the coating and that graphene nanoplatelets in the polymer can enhance crystallization. In exemplary embodiments, the improved barrier properties attributed to graphene nanoplatelets are accompanied by higher dimensional stability, which can be associated with the stiffening effect of graphene nanoplatelets, and improved thermal stability.

[0020] Packaging materials having a substrate such as paperboard and a liner including graphene nanoplatelets incorporated into a biopolymer such as polyhydroxyalkanoic acid can have many advantages over other materials. For example, the packaging materials of the present disclosure can be sourced from readily renewable materials and / or can be degradable, compostable, and / or recyclable than other packaging materials with gas and / or moisture barriers. In embodiments, the biopolymer and graphene nanoplatelet composites can provide a barrier that can replace a non-persistent barrier, can improve thermal management (e.g., through heat sealability, insulating properties, anisotropic thermal conduction properties, etc.), and / or can have microwave applications (e.g., graphene nanoplatelets can change dielectric properties). In exemplary embodiments, polyhydroxyalkanoic acid can be significantly more biodegradable than other barrier polymers such as, for example, ethylene-vinyl alcohol copolymers (EVOH), polyvinylidene chloride (PVDC), and nylon. In embodiments, the graphene nanoplatelets can provide coatings with flexural strength and / or heat sealability and / or can be used in film barrier and / or microwave heating applications.

[0021] In embodiments related to microwave applications, liners with graphene nanoplatelets can have anisotropic (e.g., strongly anisotropic) thermal conduction properties, with higher conductivity in the horizontal planes of the graphene nanoplatelets and lower conductivity in the direction perpendicular to the horizontal planes of the graphene nanoplatelets. Additionally, graphene aggregates can cause different dielectric properties in the nanocomposite. According to embodiments, graphene coated paperboard can have similar or identical reflectance, absorbance, and transmittance as standard clay-coated solid bleached sulfate (SBS) paperboard.

[0022] According to one embodiment, the packaging material includes multiple layers, each of which is derived from renewable resources and / or degradable materials up to 100%. Thus, the composite structure places little or no strain on non-renewable resources, and the use of renewable and / or degradable materials can be promoted to consumers. Furthermore, the present disclosure is directed to the use of renewable and / or degradable materials in compositions that have the added benefit of being suitable for alternative waste streams (e.g., composting, recycling, etc.), and have the advantage of laminates that include barrier layers to reduce the permeability of certain substances, and the use of paper or paperboard to improve the rigidity of the packaging drafting and high cooking temperatures.

[0023] According to an exemplary embodiment, the packaging material can be formed into the precursor material to form the respective construct (e.g., tray, carton, fast food container, cup, insulating cup, etc.). The substrate can be formed from paperboard, corrugated board, or other material having suitable properties to at least generally enable each of the above functions. Paperboard can be a heavier and more rigid caliper than plain paper, and corrugated board can be a heavier and more rigid caliper than paperboard. Typically, at least the side of the paperboard or cardboard that will become the exterior surface of the carton erected therefrom is coated with a clay coating or the like. The clay coating can be printed with product, advertising, price code, and other information or images. The precursor material can then be coated with a varnish to protect the information printed on the precursor material. The precursor material can also be coated with a moisture barrier, for example, on one or both sides. The precursor material can also be laminated or coated with one or more sheet-like materials.

[0024] The foregoing description illustrates and describes various embodiments of the present disclosure. Since various changes may be made in the above components, all matters contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not limiting. Also, various modifications, combinations, variations, etc. of the above-described embodiments are within the scope of the disclosure. In addition, the present disclosure shows and describes only selected embodiments, but various other combinations, modifications, and environments are within the scope of the present disclosure, commensurate with the above teachings, and / or within the skill or knowledge of the relevant art. Moreover, the specific features and characteristics of each embodiment can be selectively exchanged and applied with other illustrated and unillustrated embodiments without departing from the scope of the present disclosure.

Claims

1. A substrate; 1. A packaging material comprising: a liner extending along a substrate, the liner comprising at least a biopolymer and graphene nanoplatelets to provide a gas barrier along at least a portion of the packaging material, the graphene nanoplatelets being randomly dispersed in the biopolymer such that agglomeration of the graphene nanoplatelets is avoided.

2. The packaging material of claim 1 , wherein the biopolymer comprises a polyhydroxyalkanoic acid.

3. 3. The packaging material of claim 2, wherein the liner comprises less than about 5% by weight of the graphene nanoplatelets.

4. The packaging material of claim 2 , wherein the substrate comprises a paper product.

5. 10. The packaging material of claim 1, wherein the biopolymer is derived from renewable resources and is biodegradable.

6. 6. The packaging material of claim 5, wherein the substrate comprises at least one of a renewable, degradable, compostable, and repulpable material.

7. 10. The packaging material of claim 1, wherein less than about 5% by weight of the graphene nanoplatelets are incorporated into the biopolymer.

8. 1. An article of manufacture comprising a packaging material comprising a substrate and a liner extending along the substrate, the liner comprising at least a biopolymer and graphene nanoplatelets to provide a gas barrier along at least a portion of the packaging material, the graphene nanoplatelets being randomly dispersed in the biopolymer such that agglomeration of the graphene nanoplatelets is avoided.

9. The article of manufacture of claim 8 , wherein the biopolymer comprises a polyhydroxyalkanoic acid.

10. 10. The article of claim 9, wherein the liner comprises less than about 5% by weight of the graphene nanoplatelets.

11. The article of claim 9 , wherein the substrate comprises a paper product.

12. 10. The article of manufacture of claim 8, wherein the biopolymer is sourced from renewable resources and is biodegradable.

13. 13. The article of claim 12, wherein the substrate comprises at least one of a renewable, degradable, compostable, and repulpable material.

14. 10. The article of claim 8, wherein less than about 5% by weight of the graphene nanoplatelets are incorporated into the biopolymer.

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