Enhanced sealing for flexile packaging

Abstract

A packaging material and packages comprising such packaging material are provided. The packaging material comprises a laminate of a cavitated heat sealable film and a layer of recyclable material. The layer of recyclable material is selected from paper or recyclable polymeric materials. Laminates with the cavitated heat sealable film are configured to provide improved sealing compared to laminates employing a non-cavitated heat sealable film.

Description

ENHANCED SEALING FOR FLEXILE PACKAGINGCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit to U.S. Provisional Patent Application No.63 / 763,489, filed on February 26, 2025, the entire contents of which are incorporated herein by reference.FIELD OF INVENTION

[0002] The present technology relates to packaging material and packages comprising such materials. In particular, the present technology relates to a recyclable packaging material. The recyclable packaging material comprises a laminate of a cavitated heat sealable film and a layer of a recyclable material.BACKGROUND

[0003] Packaging materials formed from polymeric and sometimes paper-based materials are employed to form flexible packages for housing or storing a variety of products include both food and non-food products. The ability to form a suitable seal in the formation of the package, and particularly to achieve effective sealing in high-speed production, can be a challenge. Additionally, recyclable materials, and particularly those employing paper, face sealing challenges due to the insulative properties of paper.SUMMARY

[0004] The following presents a summary of this disclosure to provide a basic understanding of some aspects. This summary is intended to neither identify key or critical elements nor define any limitations of embodiments or claims. Furthermore, this summary may provide a simplified overview of some aspects that may be described in greater detail in other portions of this disclosure.

[0005] In one aspect, provided is a recyclable packaging material. The recyclable packaging material comprises a laminate of a cavitated heat sealable film and a layer of a recyclable material. The layer of recyclable material is selected from a paper material or arecyclable polymeric material. The laminates with the cavitated heat sealable film exhibit improved sealing compared to laminates employing a non-cavitated heat sealable film.

[0006] In packing material laminates comprising paper, the use of a cavitated heat sealable film provides a lower density film, which allows for the use of thicker heat sealable films with relatively thin paper layers to still meet the fiber-to-polymer ratio required for the material to be considered recyclable.

[0007] In one aspect, provided is a package material comprising an inner film selected from a cavitated heat sealable film and an outer film layer.

[0008] In one embodiment, the cavitated heat sealable film comprises an oriented polymeric film comprising a plurality of voids formed by a cavitating agent upon orientation of the film.

[0009] In one embodiment, the cavitating agent is selected from solid or hollow pre-formed glass or polymer spheres, metal beads or spheres, ceramic spheres, mica, talc, calcium carbonate (CaCCh), silica (SiCh), titanium oxide (TiCh), barium sulfate (BaSC ), chalk, and mixtures of two or more thereof.

[0010] In one embodiment, the oriented polymeric film is a polyolefin film, a polyamide film, ionomer films, or a polyester film.

[0011] In one embodiment, the outer film is a paper-based film.

[0012] In one embodiment, the outer film is a polymeric film.

[0013] In one embodiment, the outer film is a polyolefin film, and the cavitated heat sealable film is a polyolefin film.

[0014] In one embodiment, the inner film and the outer film are polyethylene films.

[0015] In one embodiment, the package material comprises a heat seal coating disposed on a lower surface of the cavitated heat sealable film.

[0016] In one embodiment, the package material comprises a cold seal coating disposed on a lower surface of the cavitated heat sealable film.

[0017] In one embodiment, the sealing configuration comprises a heat seal coating disposed on a lower surface of the cavitated heat sealable film, and a cold seal coating disposed on the heat seal coating.

[0018] In one embodiment, the package material is recyclable.

[0019] In another aspect, provided is a package comprising a packaging material of any of the previous aspects or embodiments.

[0020] In one embodiment, the package is formed from the packaging material.

[0021] In one embodiment, the package comprises a container having an lower end and an upper end distal to the lower end, a container wall disposed between the upper end and the lower end and defining an container interior, and a lid disposed over the upper end of the container, wherein the lid comprises the packaging material.

[0022] The following description and the drawings disclose various illustrative aspects. Some improvements and novel aspects may be expressly identified, while others may be apparent from the description and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings illustrate various systems, apparatuses, devices and related methods, in which like reference characters refer to like parts throughout, and in which:

[0024] FIGURE l is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology;

[0025] FIGURE 2 is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology;

[0026] FIGURE 3 is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology;

[0027] FIGURE 4 is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology;

[0028] FIGURE 5 is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology;

[0029] FIGURE 6 is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology;

[0030] FIGURE 7 is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology; and

[0031] FIGURE 8 is a cross-sectional view of an embodiment of a packaging material in accordance with aspects of the present technology.DETAILED DESCRIPTION

[0032] Reference will now be made to exemplary embodiments, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized, and structural and functional changes may be made. Moreover, features of the various embodiments may be combined or altered. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments. In this disclosure, numerous specific details provide a thorough understanding of the subject disclosure. It should be understood that aspects of this disclosure may be practiced with other embodiments not necessarily including all aspects described herein, etc.

[0033] As used herein, the words “example” and “exemplary” means an instance, or illustration. The words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment. The word “or” is intended to be inclusive rather than exclusive, unless context suggests otherwise. As an example, the phrase “A employs B or C,” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles “a” and “an” are generally intended to mean “one or more” unless context suggest otherwise.

[0034] Provided is a packaging material. The packaging material is a recyclable material comprising a laminate of a recyclable material and a cavitated heat sealable fdm. The use of a cavitated heat sealable film has been found to provide enhanced sealing and may be particularly useful for high-speed heat seal applications. In paper-based packaging materials, the cavitated heat sealable films provide enhanced sealing but also allows for the use of thicker heat sealable films while still meeting the paper-to-polymer ratio required for the material to be considered recyclable.

[0035] Paper-Based Packaging Material.

[0036] In one aspect, provided is a paper-based packaging material. A paper-based packaging material may comprise a laminate of a paper-based material and a cavitated heat sealable film.

[0037] Referring to FIGURE 1, a packaging material 100 comprises a paper-based layer 110 laminated to cavitated heat sealable film 120. The paper-based layer 110 can be laminated or bound to the cavitated heat sealable film 120 by an adhesive 130. The packaging material 100may include a print layer 140 disposed on the outer surface of the paper-based layer 110 to provide any desired branding, indicia, content information, and the like as may be desired. A protective coating 150 such as an overprint varnish or lacquer may be provided over the print layer 140.

[0038] The cavitated heat sealable film will generally be constituted as the inner layer of the packaging material when employed to form a food package or cover / lid for application to a container.

[0039] The packaging material may optionally employ additional sealable materials in conjunction with the cavitated heat sealable film. In embodiments, the packaging material may comprise a heat seal coating, a cold seal coating, or both a heat seal coating and a cold seal coating disposed on the lower surface of the cavitated heat sealable film. FIGURES 2-4 show embodiments of a packaging material comprising these additional seal components.

[0040] In FIGURE 2, packaging material 200 comprises a paper-based layer 210 and a cavitated heat sealable film 220 laminated via an adhesive 230. In the packaging material 200, the upper surface of the paper-based layer 210 may be printed with a print layer 240 and include a protective coating 250, such as a lacquer or overprint varnish, over the print layer 240. The packaging material 200 further comprises a heat seal coating 260 disposed on a lower surface of the cavitated heat sealable film 220. In FIGURE 2, the heat seal coating 260 is shown as a continuous layer disposed on the cavitated heat sealable film 220. It will be appreciated, however, that the heat seal coating 260 may be provided as a discontinuous or patterned coating disposed only in those regions desired for sealing in forming of a package.

[0041] FIGURE 3 is an embodiment of a packaging material 300 comprising a paper-based layer 310 and a cavitated heat sealable film 320 joined together by an adhesive 330. In the packaging material 300, the upper surface of the paper-based layer 310 may be printed with an ink to form a print layer 340 and include a protective coating 350, such as a lacquer or overprint varnish, over the print layer 340. The packaging material 300 comprises a cold seal coating 360 disposed on a lower surface of the cavitated heat sealable film 320. The cold seal coating 360 in FIGURE 3 is shown as a discontinuous or patterned coating, but it will be appreciated that the cold seal coating could be provided as a continuous coating over the entire surface of the cavitated heat sealable film 320.

[0042] FIGURE 4 is a packaging material 400 comprising a cold seal adhesive in combination with a heat sealable film. The packaging material 400 includes a paper-based layer410 and a cavitated heat sealable fdm 420 adhered via an adhesive 430. Tn the packaging material 400, the upper surface of the paper layer 410 may be printed with an ink to form a print layer 440 and include a protective layer 450, such as a lacquer or overprint varnish, over the print layer 440. The packaging material 400 includes a heat seal coating 460 disposed on a lower surface of the cavitated heat sealable film 420, and a cold seal coating 470 disposed over the heat seal coating 460. In FIGURE 4, the heat seal coating 460 is shown as a continuous coating, but it will be appreciated that the heat seal coating 460 may be provided as a discontinuous or patterned coating. Similarly, the cold seal coating 470 is shown as a discontinuous or patterned coating, but it may be provided as a continuous coating.

[0043] It will be appreciated that the foregoing are examples of suitable embodiments. For example, while the laminate is shown as having one paper film, it will be appreciated that the laminate may comprise multiple paper films as part of the construction.

[0044] Recyclable Polymeric Packaging Material

[0045] In other embodiments, the recyclable packaging material may include other film layers in place of a paper film layer. In embodiments, the packaging material may be a polymer based construction comprising one or more polymer films in place of the paper film. The polymeric packaging material comprises a polymer film and a cavitated heat sealable film. Generally, to provide a polymeric recyclable packaging material in accordance with the present technology, the polymer film(s) and the cavitated heat sealable film will be polyethyelene-based films.

[0046] Referring to FIGURE 5, a packaging material 500 comprises a polymer film layer 510 laminated to cavitated heat sealable film 520. The polymer film layer 510 can be laminated or bound to the cavitated heat sealable film 520 by an adhesive 530. The packaging material 500 may include a print layer 540 disposed on the outer surface of the polymer film layer 510 to provide any desired branding, indicia, content information, and the like as may be desired. A protective coating 550, such as an overprint varnish or lacquer, may be provided over the print layer 540.

[0047] The cavitated heat sealable film will generally be constituted as the inner film layer of the packaging material when employed to form a food package or cover / lid for application to a container.

[0048] The packaging material may optionally employ additional seal materials in conjunction with the cavitated heat sealable film. In embodiments, the packaging material may comprise a heat seal coating, a cold seal coating, or both a heat seal coating and a cold seal coating disposed on the lower surface of the cavitated heat sealable film. FIGURES 6-8 show embodiments of a packaging material comprising these additional seal components.

[0049] In FIGURE 6, packaging material 600 comprises a polymer film layer 610 and a cavitated heat sealable film 620 laminated via an adhesive 630. In the packaging material 600, the upper surface of the polymer film layer 610 may be printed with a print layer 640 and include a protective coating 650, such as a lacquer or overprint varnish, over the print layer 640. The packaging material 600 further comprises a heat seal coating 660 disposed on a lower surface of the cavitated heat sealable film 620. In FIGURE 6, the heat seal coating 660 is shown as a continuous layer disposed on the cavitated heat sealable film 620. It will be appreciated, however, that the heat seal coating 660 may be provided as a discontinuous or patterned coating disposed only in those regions desired for sealing in formation of the package.

[0050] FIGURE 7 is an embodiment of a packaging material 700 comprising a polymer film layer 710 and a cavitated heat sealable film 720 joined together by an adhesive 730. In the packaging material 700, the upper surface of the polymer film layer 710 may be printed with an ink to form a print layer 740 and include a protective coating 750, such as a lacquer or overprint varnish 750, over the print layer 740. The packaging material 700 comprises a cold seal coating 760 disposed on a lower surface of the cavitated heat sealable film 720. The cold seal coating 760 in FIGURE 7 is shown as a discontinuous or patterned coating, but it will be appreciated that the cold seal coating 760 could be provided as a continuous coating over the entire surface of the cavitated heat sealable film 720.

[0051] FIGURE 8 is a packaging material 800 comprising a cold seal adhesive in combination with a heat sealable film. The packaging material 800 includes a polymer film layer 810 and a cavitated heat sealable film 820 adhered via an adhesive 830. In the packaging material 800, the upper surface of the polymer film layer 810 may be printed with an ink to form a print layer 840 and include a protective layer 850, such as a lacquer or overprint varnish, over the print layer 840. The packaging material 800 includes a heat seal coating 860 disposed on a lower surface of the cavitated heat sealable film 820, and a cold seal coating 870 disposed over the heat seal coating 860. In FIGURE 8, the heat seal coating 860 is shown as a continuous coating, but itwill be appreciated that the heat seal coating 860 may be provided as a discontinuous or patterned coating. Similarly, the cold seal coating 870 is shown as a discontinuous or patterned coating, but it may be provided as a continuous coating.

[0052] Cavitated Heat Sealable Film

[0053] The cavitated heat sealable film is a polymeric material that is capable of forming a seal to itself or a surface under the application of heat. The cavitated heat sealable film generally has the properties of softening of the polymeric material upon heating without melting the other layers in the film or the material to which it is being attached. The heat sealable film is a cavitated polymeric film.

[0054] Cavitated polymeric materials are produced by dispersing a cavitating agent (e.g., micro-scale and / or nano-scale inclusions) into polymeric materials and subsequently orienting (or stretching) the polymeric materials; the presence of the inclusions forming micro-scale and / or nano-scale cavities, or voids, within the oriented polymeric materials.

[0055] The cavitating agent is selected from an inorganic material. Examples of suitable cavitating agents include, but are not limited to, solid or hollow pre-formed glass or polymer spheres, metal beads or spheres, ceramic spheres, mica, talc, calcium carbonate (CaCCh), silica (SiCh), titanium oxide (TiCh), barium sulfate (BaSCE), chalk, and mixtures of two or more thereof.

[0056] The cavitating agent may have a particle size as desired to provide the desired degree of void formation or void volume. In embodiments, the cavitating agent has a particle size of from about 0.1 micron to about 10 microns, about 0.2 micron to about 8 microns, from about 0.5 to about 6 microns, from about 1 micron to about 5 microns, or from about 2 to about 4 microns.

[0057] The cavitating agent may be of any desired shape. For example, the cavitating agent(s) may be substantially spherical (e.g., have an aspect ratio of about 1), non-spherical, ellipsoidal, polyhedral, distorted spherical, distorted ellipsoidal, or polyhedral shaped particles, or platelets. The cavitating agent may have an aspect ratio of from about 0.1 to about 2000.

[0058] The cavitated polymeric film may be a single layer film or a multi-layer film. A multi-layer polymeric film comprises two or more layers. Such may be formed by co-extrusion processes and / or lamination of individual polymer layers together to form a multi-layer film material. Where the heat sealable film is a multi-layer film, the cavitating agent can be added toany layer of the film. Where the cavitated heat sealable film is a multi-layer film, at least one of the two or more layers is cavitated.

[0059] The amount of the cavitating agent to be incorporated may correspond to the desired degree of void formation upon stretching. The film may comprise a cavitating agent or a blend of the cavitating agents in an amount of about 0.5 to about 70%, about 1.0 to about 60.0%, about 3.0 to about 60.0%, about 5.0 to about 50.0%, about 5.0 to about 30.0%, about 5.0 to about 20.0%, or about 5.0 to about 15.0%, based on the total weight of the layer to which the cavitating agent is added.

[0060] The cavitated heat sealable film may comprise a polymeric material as desired for a particular purpose or intended application. In one embodiment, the cavitated heat sealable film is selected from a polyolefin film, a polyamide film, ionomer films, a polyester film, and the like. When the packaging material is a paper-based packaging material, the cavitated heat sealable film is not particularly limited with respect to the polymeric material(s) of the film. For the polymeric-based films, the cavitated heat sealable film will generally be selected from a polyethylene film.

[0061] Examples of suitable polyolefin resins that may be used in the heat sealable film include, but are not limited to, homopolymers and copolymers of olefins having 2-8 carbon atoms, and copolymers of olefins having 2-8 carbon atoms with monomer(s). Examples of such olefin resins include, but are not limited to, high-density polyethylene (FIDPE), low-density polyethylene (LDPE), linear low-density polyethylene resin, and other such polyethylene, polypropylene, polyisobutylene, poly (1 -butene), poly-4-methylpentene, polyvinylcyclohexane, polystyrene, poly(p-methylstyrene), poly(a-methyl styrene), ethylene / propylene block copolymers, ethylene / propylene random copolymers, ethylene / butene-1 copolymers, ethylene / 4-m ethyl- 1 -pentene copolymers, ethyl ene / hexene copolymers, and other such a-olefin copolymers, ethylene / vinyl acetate copolymers, ethylene / acrylic acid copolymers, ethylene / methyl methacrylate copolymers, ethylene / vinyl acetate / methyl methacrylate copolymers, ionomer resins, and so forth may be cited. Moreover, it is also possible use chlorinated polyolefins obtained by chlorination of any of these polyolefins.

[0062] Particularly suitable olefin resins include low density polyethylene (hereinafter may be abbreviated as “LDPE”), polypropylene (PP) and polyethylene obtained by polymerization in the presence of a metallocene catalyst (hereinafter may be abbreviated as “M-LLDPE”). Further, in case where a resin material has a higher melting point higher than a desiredseal initiation temperature, the melting point may be adjusted to the above defined range by blending the other resin thereinto to depress the melting point. Examples of LLDPE include, but are not limited to, LLDPE (commercial products), UNIPOL (by Union Carbide, Corporation), DOWLEX (by Dow Chemical Company), SCREAR (by DuPont Canada), MARLEX (by Philips), NEO-ZEX and ULTZEX (by Mitsui Chemicals, Inc.), NISSEKI LINIREX (by Nippon Oil Corporation) and STAMIREX (by DSM) are mentioned.

[0063] Another category of polymer resin suitable for a heat sealable film includes polyester materials. An example of a suitable polyester is ethylene / unsaturated ester copolymers. An ethylene / unsaturated ester copolymer may comprise any ethylene / unsaturated ester copolymer or derivative thereof. For example, the ethylene / unsaturated ester copolymer or derivative thereof may comprise one or more of ethylene / methyl acrylate copolymer, ethylene / methyl methacrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / ethyl methacrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / 2-ethylhexyl methacrylate copolymer, ethylene / vinyl acetate copolymer, and blends thereof, and more particularly an ethylene / vinyl acetate copolymer or blends thereof.

[0064] Other examples of suitable polyesters suitable for a heat sealable film include homopolymers and copolymers of alkyl-aromatic esters. For example, the heat sealable film may comprise polyethylene terephthalate (PET), amorphous polyethylene terephthalate (APET), crystalline polyethylene terephthalate (CPET), glycol-modified polyethylene terephthalate (PETG), and polybutylene terephthalate. In some aspects, the heat seal layer may comprise copolymers of terephthalate and isophthalate, such as, for example, polyethylene terephthalate / isophthalate copolymer. In some aspects, the heat seal layer may comprise homopolymers and copolymers of aliphatic esters such as, for example, polylactic acid (PLA) and polyhydroxyalkonates, such as, for example, but not limited to, polyhydroxypropionate, poly (3 -hydroxybutyrate) (PH3B), poly(3 -hydroxy valerate) (PH3V), poly(4-hydroxybutyrate) (PH4B), poly(4-hydroxyvalerate) (PH4V), poly(5-hydroxyvalerate) (PH5V), poly(6-hydroxydodecanoate) (PH6D), and blends thereof.

[0065] The thickness of the cavitated heat sealable film may be selected as desired for a particular purpose or intended application. The use of cavitated heat sealable films in paper-based application provides a lower density film that may allow for the use of thicker heat seal layers than in paper-based materials that do not employ cavitated heat seal films. In paper-based films,the thickness of the cavitated heat sealable film is generally only limited to the extent that the cavitated heat sealable film should be provided such that the packaging material comprises at least 80% by weight of recyclable fiber material. In polymeric-based films, the thickness of the cavitated heat sealable film is generally not limited. In polymer-based films, the cavitated heat sealable film may have a thickness that is less than or greater than the other polymeric films in the construction.

[0066] In embodiments, the heat sealable film can have a thickness of from about 6 pm to about 200 pm, from about 20 pm to about 175 pm, from about 25 pm to about 150 pm, from about 40 pm to about 125 pm, from about 50 pm to about 100 pm, or from about 75 pm to about 90 pm.

[0067] Heat Seal Coating (Adhesive)

[0068] As discussed herein, the packaging material may optionally include other seal materials in addition to the heat sealable film. In embodiments, the packaging material may comprise a heat seal coating disposed on the cavitated heat sealable film. Heat seal coatings are thermoplastic materials that can be coated onto a substrate, dried, and then reactivated by heat and pressure. Upon drying, they form a coating that can be heat-activated and bonded to other substrates. They are non-tacky materials at ambient temperature and become molten liquids upon heat activation during the product assembly process. The term “heat seal coating” and “heat seal adhesive” may be used interchangeably.

[0069] The heat seal coating may be chosen from any material suitable as a heat seal coating. The heat seal coating may be a solvent-based or water-based coating composition. Example of suitable classes of materials include, but are not limited to, ethylene vinyl acetate, polyolefins such as polyethylene, polypropylene, or the like, polyamides, polyvinyl chloride, and the like.

[0070] The heat seal coating may be applied to provide a dry coating weight in the range of about 2 to about 25 g / m2, about 5 g / m2to about 20 g / m2, about 8 g / m2to about 18 g / m2, or about 15 g / m2to about 15 g / m2.

[0071] Cold Seal Coating (Adhesive)

[0072] The packaging material may optionally comprise a cold seal coating that is used with the cavitated heat sealable film (with or without a heat seal coating).

[0073] The cold seal coating can be any suitable material useful for sealing / adhering materials at temperatures between 0° C. and 30° C. Examples of suitable cold seal adhesive materials include, but are not limited to, natural or synthetic rubber or “latex”.

[0074] An example of a suitable cold seal adhesive is a composition based on mixtures of natural or synthetic latex dispersions and one or more dispersions selected from an aqueous polyacrylic dispersion, a poly (meth)acryl ate dispersion, an acrylate and / or methacrylate based copolymer dispersion. An example is a cold seal adhesive composition containing 40-65% by weight of a natural latex emulsion, preferably with an ammonia content giving pH values of approximately 10, 20-50% by weight of a styrene-acrylate emulsion, and small amounts (e.g., 1-5% by weight) of wetting agents, latex stabilizers, antioxidants, biocides, thickeners, and optionally tackifiers.

[0075] Another example of a suitable cold seal coating is a natural rubber comprising more than 50% but less than 90% natural latex in the formulation composition and one or more of the following components: acrylic polymer or copolymers; styrene acrylic polymer or copolymer where the monomers are mainly but not exclusively butyl acrylate, methyl methacrylate, and ethyl hexyl acrylate; styrene copolymer; and, vinyl acetate ethylene copolymer. The total synthetic polymer proportion of the cold-seal formulation may be from about 10% and 50% of the final composition.

[0076] The cold seal adhesive layer may completely or only partially be disposed on the reverse side of the second web of the multi-layer material or tag. A partially disposure is particularly advantageous to reduce cost or to avoid contact of the cold seal layer to the object in the final application. Preferably the cold seal layer is applied in stripes, most preferably in the web direction of both flexible webs. Nevertheless, any useful pattern of the cold seal adhesive may be chosen depending on the application. As the cold seal adhesive is only used in the areas which are contacted to each other in the final application only these areas need to have the adhesive.

[0077] The cold seal adhesive layer typically has a dry coating weight in the range of about 2 to about 25 g / m2, about 5 g / m2to about 20 g / m2, about 8 g / m2to about 18 g / m2, or about 15 g / m2to about 15 g / m2.

[0078] The packaging material comprises a film that serves as a structural film in addition to the cavitated heat sealable film. The additional film is selected from a paper film or a polymeric film.

[0079] In embodiments where the structural film is selected from a polymeric material, the polymer is selected from a polyolefin. Examples of suitable polyolefins include, but are not limited to polyethylene, polypropylene, polybutylene, and the like. In one embodiment, the polyolefin is selected from polyethylene. The polyethylene is not particularly limited and can be selected from various types of polyethylene including, for example, a high-density polyethylene, a medium density polyethylene, or a low density polyethylene. It will be appreciated that the polymer film layer can be formed from a blend of polymers, e.g., a blend of different polyolefins, a blend of a particular polyolefin (e.g., a blend of different polyethylenes), and the like.

[0080] The packaging material may comprise one or more paper layers. The recyclable flexible packaging film may comprise a recyclable paper, for example, a commercial fiber paper that is highly calendared.

[0081] The paper material may be modified or have incorporated therein various fillers (e.g., inorganic fillers) or other materials to provide or impart certain properties to the paper material. In embodiments, the paper material may have a polymer material incorporated in the material. The polymer material incorporated in the paper material should generally be provided to allow for the paper to still be recyclable if desired. Polymers that may be included in the paper material may include those described herein with respect to the optional polymeric film layers.

[0082] The thickness of the structural layers may be selected as desired for a particular purpose or intended application. In embodiments, structural layers formed from polymeric films may have a thickness of from about 4 pm to about 30 pm, from about 7 pm to about 25 pm, or from about 9 pm to about 20 pm.

[0083] The packaging material may comprise one or more paper layers. The recyclable flexible packaging film may comprise a recyclable paper, for example, a commercial fiber paper that is highly calendared. The paper can have a weight as desired for a particular purpose or intended application. In embodiments, the paper can have a weight of from about 20 gsm to about 500 gsm, from about 50 gsm to about 250 gsm, or from about 100 gsm to about 200 gsm. In embodiments, the paper is a food grade paper. Food grade papers can be uncoated, single coated, double coated. The paper may have a natural color or include one or more pigments.

[0084] The packaging material may optionally include other layers to provide particular characteristics or properties to the packaging material. In embodiments the packaging material may include one or more barrier layers. The barrier layer can be configured as a gas barrier layer, a moisture layer, or as both a gas and moisture barrier layer.

[0085] Gas barrier layers may be, for example, oxygen barrier layers configured to have a selected oxygen transmission rate and low oxygen permeability if such is desired for a particular package application. Non-limiting examples of gas barrier layers include those comprising EVOH, polyvinylidene chloride, polyamide, polyester, polyalkylene carbonate, polyacrylonitrile, nanocomposite, a metallized film such as aluminum vapor deposited on a polyolefin, etc.

[0086] In embodiments, the packaging material may comprise a moisture barrier layer having a moisture permeability sufficiently low to protect the contents of the package from deteriorating or losing freshness or crispness. Non-limiting examples of moisture barrier layers include, but are not limited to, aluminum foil, PVDC, or polyolefins such as LDPE or LLDPE.

[0087] The thickness of the barrier layer(s) may be selected to provide the desired barrier performance. In embodiments, a barrier layer may have a thickness of from about 1 pm to about 5 pm, from about 2 pm to about 4 pm, or from about 1 pm to about 3 pm.

[0088] It will be appreciated that the packaging material can comprise one or more adhesive layers to adhere adjacent layers of the packaging laminate together. The adhesive is not particularly limited and can be selected by those skilled in the art for adhering adjacent layers of selected materials. Examples of suitable adhesives include, but are not limited to, acrylic adhesives, polyolefins, natural rubber, synthetic rubber, styrenic polymers, silicones, polyurethanes, and the like. Some examples include, but are not limited to, modified polyolefins, which are mostly based on LDPE or LLDPE co-polymers or, graft co-polymers with functional-group containing monomer units, such as carboxylic or glycidyl functional groups, e.g. (meth)acrylic acid monomers or maleic anhydride (MAH) monomers, (i.e. ethylene acrylic acid copolymer (EAA) or ethylene methacrylic acid copolymer (EMAA)), ethylene-glycidyl(meth)acrylate copolymer (EG(M)A) or MAH-grafted polyethylene (MAH-g-PE). When the packaging material is to be used for food packaging, the adhesives are generally selected from food-grade materials.

[0089] It will be appreciated that the paper material may be modified or have incorporated therein various fillers or other materials to provide or impart certain properties to the papermaterial. In embodiments, the paper material may have a polymer material incorporated in the material. The polymer material incorporated in the paper material should generally be provided to allow for the paper to still be recyclable if desired. Polymers that may be included in the paper material may include those described herein with respect to the optional polymeric film layers.

[0090] The present packaging materials are provided for housing or storing a product, e.g., a food item. The present packaging materials are not configured for heating of a food product disposed therein, and the packaging materials will generally be free of a susceptor material (which is commonly employed in packages configured for heating of food via microwave energy). Rather, the packaging material is configured to facilitate heat sealing of the paper-based packaging material.

[0091] The packaging material can be formed in any suitable manner. The various structural layers (e g., heat sealable film, polymeric film layer, and / or paper layer) may be formed by adhesively laminating the respective layers to one another. The heat seal coating and / or the cold seal adhesive may be applied to the inner most structural layer (e.g., a polymeric film or heat sealable film) via any suitable coating techniques such as, but not limited to, roller coating, meyer bar, die systems, or rotogravure. For the partial coating, the die system or rotogravure technique is preferred. The upper surface of the laminate can be subjected to a printing process (e.g., but not limited to, rotogravure printing, flexographic, digital printing, or the like) to apply graphics or indicia to the package. This can be done to the outermost paper layer prior or subsequent to formation of the bulk laminate (in a construction with multiple paper layers and / or polymeric film layers). The outer surface of the upper most paper layer may optionally be treated prior to printing to render the surface more receptive to the inks. Such treatments include corona discharge or flame treatment. Alternatively, the outer structural layer of the film can be reverse printed prior to lamination to an inner layer of the packaging material.

[0092] The upper surface of the laminate can be subjected to a printing process (e.g., but not limited to, rotogravure printing, flexographic, digital printing, or the like) to apply graphics or indicia to the package. This can be done to the outermost paper layer prior or subsequent to formation of the bulk laminate (in a construction with multiple paper layers and / or polymeric film layers). The outer surface of the upper most paper layer may optionally be treated prior to printing to render the surface more receptive to the inks. Such treatments include corona discharge or flame treatment.

[0093] The present packaging materials are provided for use in a package configured for housing or storing a product, e.g., a food item. The packaging material may be employed to form all of or a portion of a package for housing one or more items.

[0094] In embodiments, the packaging material may be used to form a flexible package (e.g., a pouch, bag, wrapper, or the like). The packaging can be formed from any suitable now known or later discovered packaging method. Examples of suitable methods for forming packaging include, but are not limited to, vertical form / fill / seal (VFFS), horizontal form / fill / seal (HFFS), therm oforming / lidstock, and continuous horizontal packaging. It will be appreciated that those skilled in the art will be capable of employing the present packaging film to provide the necessary conditions to form the shape of the packaging and effect sealing. In one embodiment of a flow wrapping process, the heat-sealing jaws that compress sides of the packaging material to form the end seals may be configured such that the sealing jaws will penetrate into the packaging material to a selected depth. This may allow for increased efficiency in transfer of heat to particular layers such as, for example, where the packaging material comprises paper layer(s). In one embodiment, the packaging film can be employed to form a bag, pouch, or sachet. Such configurations are generally formed from multiple sheets of packaging film brought together to form the walls of the package. A pouch or bag may be sealed in a fin seal or lap seal configuration. A sachet may have side seals and end seals. Fitments or other closures may be sealed to any part of the recyclable film.

[0095] In one embodiment, the packaging film is employed as a cover or lid for a container. The container may be, for example, a tray, cup, or the like. The container material is not particularly limited and can be selected as desired. The container material may be, for example, flexible, semi-rigid, or rigid. Examples of suitable materials for a container include, but are not limited to, polyester, polyolefin (e.g., polyethylene, polypropylene, etc.), polystyrene, polyvinyl chloride, paper, metal, glass, ceramic, and the like. The container will typically have an upper surface, and the package film is sealed to the upper surface of the container. The package film is sealed to the container such that the package film can be peeled away from the container body to expose the contents of the container. The cover or lid that is sealed to a container body by application of heat and pressure.

[0096] The sealing configuration may form a hermetic seal and hermetically sealed package. The terms “hermetic seal” or “hermetically sealed”, as used herein, refer to a seal that is maintained against the flow of air or fluid, in other words, an airtight or liquid proof seal.

[0097] The package may also be provided with a modified atmosphere wherein the package comprises a gaseous material other than atmospheric gas. In particular, it may be desirable to replace or lower the content of oxygen or other oxidative gases in a package. Such modified atmosphere packages may be provided to reduce or eliminate atmospheric gases or free oxygen or other oxidative gases from the package. The package atmosphere may be modified by flushing the package with gases such as, but not limited to, carbon dioxide, nitrogen, argon, krypton, xenon, etc.

[0098] The packaging film can be used to package any type of product. Examples of suitable products include, but are not limited to, foods, beverages, pharmaceuticals, nutraceuticals, cosmetics, medical products, electronic devices and products, wipes, etc. Examples of food products that can be packaged using the packaging films include, but are not limited, dry foods, frozen foods, fresh foods, refrigerated foods, and the like. Examples of food products include but are not limited to, cereals, chips, pretzels, bars (e.g., candy bars, protein bars, granola bars, etc.), nuts, raisins, pizzas, tortillas, gum, popcorn, a grain, a seasoning, popsicles, a frozen bar, ready -to-bake dough, pet food, vegetables, fruits, meats, cheese, sugar and powders, candy, and the like.

[0099] It will be appreciated that the foregoing embodiments are exemplary embodiments of packaging materials, but packaging materials are not necessarily limited to such embodiments. For example, it will be appreciated that a packaging material may comprise two or more film layers; a configuration shown as reverse printed could be provided with printing on the outer / upper surface of the outermost film layer; a material shown as having printing on the upper surface of the outer film could instead be reverse printed; and the like. Additionally, the multifilm constructions could be provided as single film constructions.

[0100] It will be appreciated that the foregoing embodiments are exemplary embodiments of packaging materials, but packaging materials are not necessarily limited to such embodiments. For example, it will be appreciated that a packaging material may comprise two or more film layers; a configuration shown as reverse printed could be provided with printing on the outer / upper surface of the outermost film layer; a material shown as having printing on the uppersurface of the outer film could instead be reverse printed; and the like. Additionally, the multifilm constructions could be provided as single film constructions.

[0101] What has been described above includes examples of the present specification. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present specification, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present specification are possible. Accordingly, the present specification is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

[0102] The foregoing description identifies various, non-limiting embodiments of a packaging material. Modifications may occur to those skilled in the art and to those who may make and use the invention. The disclosed embodiments are merely for illustrative purposes and not intended to limit the scope of the invention or the subject matter set forth in the claims.

Claims

AMENDED CLAIMSreceived by the International Bureau on 13 July 2026What is claimed is:

1. A packaging material comprising:an inner film comprising a cavitated heat sealable film;an outer film layer joined to an upper surface of the inner film; and a sealing configuration comprising a heat seal coating disposed on a lower surface of the cavitated heat sealable film and a cold seal coating disposed on the heat seal coating.

2. The packaging material of claim 1, wherein the cavitated heat sealable film comprises an oriented polymeric film having a plurality of voids formed by a cavitating agent upon orientation of the film.

3. The packaging material of claim 2, wherein the cavitating agent is selected from solid or hollow pre-formed glass or polymer spheres, metal beads or spheres, ceramic spheres, mica, talc, calcium carbonate (CaCCh), silica (SiCh), titanium oxide (TiCh), barium sulfate (BaSO4), chalk, and mixtures of two or more thereof.

4. The packaging material of claim 2, wherein the oriented polymeric film is a polyolefin film, a polyamide film, an ionomer film, or a polyester film.

5. The packaging material of claim 1, wherein the outer film is a paper-based film.

6. The packaging material of claim 1 , wherein the outer film is a polymeric film.

7. The packaging material of claim 2, wherein the outer film is a polyolefin film, and the cavitated heat sealable film is a polyolefin film.

8. The packaging material of claim 1, wherein the inner film and the outer film are independent polyethylene films.

9. The packaging material of claim 1, wherein the packaging material is recyclable.

10. The packaging material of claim 1, wherein the cold seal coating comprises a material adhering at temperatures between 0° C. and 30° C.

11. The packaging material of claim 1, further including a print layer disposed on an upper surface of the outer layer.

12. The packaging material of claim 1, wherein the outer layer is joined to the inner layer by an adhesive.

13. A package comprising a packaging material according to any one of claims 1-12.

14. The package of claim 13, wherein the package is formed from the packaging material.

15. The package of claim 13, wherein the package comprises a container having a lower end and an upper end distal to the lower end, a container wall disposed between the upper end and the lower end and defining a container interior, and a lid disposed over the upper end of the container, wherein the lid comprises the packaging material.

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