WO2025005903A1

WO2025005903A1 - Compostable high barrier film and methods of constructing the same

Info

Publication number: WO2025005903A1
Application number: PCT/US2023/026285
Authority: WO
Inventors: Marcelo B. ELIAS; Ross K. GRUETZMACHER; Otacilio T. Berbert
Original assignee: Amcor Flexibles North America Inc
Current assignee: Amcor Flexibles North America Inc
Priority date: 2023-06-27
Filing date: 2023-06-27
Publication date: 2025-01-02
Anticipated expiration: 2025-12-27

Abstract

A compostable high barrier film having a thickness comparable to traditional non-compostable films for use in packaging and a method of manufacture. The compostable high barrier film includes a compostable outer film defining a first exterior surface, a sealing layer defining a second exterior surface and having a thickness in a range of about 2 micron to 15 micron, a barrier layer positioned between the sealing layer and the compostable outer film, and an adhesive layer positioned between the barrier layer and the compostable outer film with the compostable high barrier film having a thickness in the range of about 20 micron to 50 micron. The compostable high barrier film is manufactured from a pair of separate film structures that are laminated together and subsequently deconstructed to form a compostable high barrier film having a thickness that is considered comparable to traditional non-compostable films.

Description

COMPOSTABLE HIGH BARRIER FILM AND METHODS OF CONSTRUCTING THE SAME

TECHNICAL FIELD

[001 ] This disclosure is related to compostable multilayer films that are suitable for packaging food products that require high barrier properties and are capable of being produced in a thickness comparable to traditional non- compostable films. More particularly, the disclosure is related to a thin and compostable film structure for use in packaging snacks and confections and a method of constructing the same.

BACKGROUND

[002] It has become increasingly desirable to design flexible packaging structures that are more sustainable. One sustainable solution is the use of a film or film laminate having a compostable structure comprising compostable polymers. A compostable structure is generally defined as comprising biodegradable polymeric materials which can be digested by micro-organisms within a given environment to degrade over time at a consistent rate into water, CO2, biomass, and inorganic compounds without leaving any visible residue or toxic residue. More particularly, if compostable, the packaging should be able to fulfill well established compostable standards, such as the standard established by ASTM D6400, that require disintegration and biodegradation at industrial and home composting conditions (12 weeks at 58°C or 26 weeks at 21 °C, respectively) to conform to chemical characterization and ecotoxicity requirements.

[003] Despite the obvious sustainable value, these compostable structures and compostable polymers, in general, are disfavored in certain applications requiring a barrier. Further, typical compostable structures, due to manufacturing limitations requiring tenter frame assets, are generally produced in a thickness that is considered much thicker than a traditional non- compostable structure, such as the thickness of an oriented polypropylene (OPP) film.

[004] The typical non-compostable film structure used within the snack and confection industries is a biaxially oriented polypropylene (BOPP) laminate produced from a blown, cast, or machine direction orientation (MDO) film machine and includes a metallized layer with an overall final thickness of about 30 micron (1 .2 mil). These typical films are considered thin and high barrier wherein it is desired to have water vapor transmission rates (WVTR) of about below 0.3 g/m²/day (38°C, 90% R.H.) when tested according to ASTM F1249 for Water Vapor Transmission Rate Through Plastic Film and Sheeting Material Using a Modulated Infrared Sensor.

SUMMARY

[005] The developments described herein include multilayer structures that can expand the applicability of compostable materials by providing high barrier and thin packages for particular use in packaging snacks and confections. The compostable high barrier film comprises a compostable outer film defining a first exterior surface of the compostable high barrier film. A sealing layer defines a second exterior surface of the compostable high barrier film, with this sealing layer having a sealing layer thickness in a range from about 2 micron to 15 micron. A barrier layer is positioned between the compostable outer film and the sealing layer. An adhesive layer is positioned between the barrier layer and the compostable outer film with the compostable high barrier film having an overall thickness in a range of from 20 micron to 50 micron. This compostable high barrier film structure provides a compostable film having high barrier properties and a thickness comparable to more traditional and non-compostable structures for use in packaging.

[006] The compostable resins for the compostable high barrier film are selected from the group comprising at least one of a polylactic acid (PLA) polymer, amorphous polylactic acid (aPLA), polybutylene adipate terephthalate (PBAT) polymer, polybutylene succinate (PBS) polymer, polyhydroxyalkanoates (PHAs), polyhydoxybutyrate (PHB), 4- hydroxybenzoate hydroxylase (PHBH), cellulose acetate (CA), poly(vinyl alcohol) (PVOH), a cellophane, a compostable paper, or combinations thereof.

[007] The sealing layer defining the second exterior surface of the compostable high barrier film is generally provided from a sealant structure that is produced from a coextruded polyolefinic based film comprising a layered structure having distinct compostable and polyolefinic layers to promote controlled delamination resulting in the final compostable high barrier film for packaging. Accordingly, the compostable layers of the coextruded film are coated with the barrier layer being of the type of barrier that could be considered high barrier, such as, but not limited to, a metal or an inorganic deposition that is liquid coated or deposited for forming the barrier layer. This barrier layer may be a vacuum deposited barrier layer. Alternately, this barrier layer may be deposited by way of an atmospheric atomic layer deposition. The sealant structure including the barrier layer is laminated via the adhesive layer to the compostable outer film to generally adhere the barrier layer and the sealing layer to the compostable outer film. After lamination, the polyolefinic portion of the sealant structure coextruded film is removed resulting in the desired final structure of the compostable high barrier film.

[008] The sealing layer comprises compostable resins and other resins (ensuring that compostability limit requirements are fulfilled) selected from the group comprising at least an amorphous polylactic acid (aPLA), polybutylene adipate terephthalate (PBAT) polymer, polybutylene succinate (PBS) polymer, polyhydroxyalkanoates (PHAs), 4-hydroxybenzoate hydroxylase (PHBH), polylactic acid (PLA) polymer, polyhydoxybutyrate (PHB), butanediol vinyl alcohol copolymer (BVOH), such as G-Polymer™ amorphous vinyl alcohol resin produced by Mitsubishi Chemical Group, ethylene vinyl alcohol copolymer (EVOH), ethylene vinyl acetate (EVA), cyclic olefin copolymer (COC), or combinations thereof.

[009] This compostable high barrier film structure of the present disclosure when tested provides both a low water vapor transmission (WVTR) and low oxygen gas transmission rate (OTR), wherein the compostable high barrier film has a WVTR according to ASTM F1249 of about less than 0.5g/m²/24 hours at 38°C and 90% relative humidity and an OTR according to ASTM F1927 of about less than 0.5 cc/m²/24 hours at 23°C and 0% relative humidity amounting to a high barrier surface capable of protecting the internal contents of a package formed from the resultant compostable high barrier film.

[010] The compostable high barrier film may include a printed indica layer. In an embodiment, this printed indica layer is reverse printed onto an interior surface described as a non-exposed side of the outer compostable film such that the printed indica is visible through the first exterior surface but also protected by the barrier layer and sealant layer after lamination.

[011] In an embodiment of the compostable high barrier film of the present disclosure, the final compostable high barrier film for packaging comprises the compostable outer film having a thickness of about 25.4 micron (1 .0 mil) and being an MDO or blown or cast polylactic acid (PLA) polymer based film defining a first exterior surface of the compostable high barrier film and having an interior surface. The interior surface may be reverse printed with the printed indica. The adhesive layer is placed adjacent to the interior surface of the compostable outer film. If a print indicia is utilized, the adhesive layer is placed adjacent to the print indicia. The adhesive layer is selected to adhere the barrier layer and the sealing layer to the compostable outer film. The adhesive layer may be made of a compostable adhesive material. In an embodiment, the barrier layer is a vacuum deposited metalized layer of aluminum and the sealing layer comprises aPLA having a thickness of about 5.08 micron (0.2 mil). Accordingly, this resultant compostable high barrier film provides a high barrier and compostable structure with a thickness comparable to that of a traditional BOPP structure for use as a packaging film.

[012] To produce the resultant compostable high barrier film structure of the above embodiment having high barrier properties, the sealant structure is constructed from the coextruded film, either blown or cast, and often referred to herein as a liner. An embodiment of the coextruded film functioning as the liner comprises a layer of polyethylene (PE) having a thickness of about 38.1 micron (1 .5 mil), a delamination layer comprised of EVA having a thickness of about 7.62 micron (0.3 mil), the sealing layer comprising aPLA, and the barrier layer which is metalized on the aPLA sealing layer. The construction of this liner and combination of materials is selected based upon the distinct chemical composition of each of the distinct layer types, wherein the delamination layer of EVA is selected as it bonds tightly to PE, but only slightly to the aPLA (slight being below 30gf/in when subjected to a bond strength test, such as ASTM F 904). However slight, the bond strength between the EVA and aPLA is strong enough to avoid delamination during the metallization and lamination processes to produce the resultant compostable high barrier film. Accordingly, the delamination layer of the sealant structure could be any incompatible polyolefin chemically modified to promote slight adhesion to avoid premature delamination during conversion. Further, the components of the liner are utilized to provide a generally less stiff surface when compared to traditional bi-oriented compostable materials; this less stiff property reduces noise of the film during use and allows for a more consistent and effective sealing layer and barrier layer during the forming process.

[013] After the completion of lamination where the barrier layer and sealing layer are adhered via the adhesive to the compostable outer film, the liner is removed, wherein the delamination layer of the coextruded film will separate from the sealing layer. The sealing layer will remain adhered to compostable outer film and form the second exterior surface. To comport with the sustainable goal of developing a compostable high barrier film for packaging, the liner, with the majority of the structure comprising PE and only a small percentage of EVA, for example, can be reused in another process or recycled or repurposed in a polyethene waste stream.

[014] In an alternate embodiment, the sealing layer may be constructed from a pair of distinct layers of BVOH and aPLA, or BVOH with EVOH blends, or BVOH and PBAT.

[015] To ensure an appropriate high barrier, when a metal is deposited or formed, it may be completed in multiple passes, such as, but not limited to two passes of metallization.

[016] In various embodiments, the solutions presented here provide for 1 ) the desired functionality for product protection preventing moisture loss and product oxidation, 2) the prevention of barrier deterioration, delamination, or chemical attack of the package during the product shelf-life and/or 3) the enablement of biodegrading and disintegrating under industrial or home composting conditions. The compostable high barrier film may be particularly suitable for use as a packaging film in packaged products, enabling extended shelf-life storage of snack and confection products.

[017] In some embodiments, the coextruded film for forming the sealant structure may include multiple polyolefin based layers, such as, but not limited to, a polyethylene film having five distinct PE resin layers in percentages from 10% to 20% of the total film weight. [018] The compostable high barrier film may be free from paper and cellulose.

[019] Also disclosed herein are packaged products including a package made of an embodiment of the compostable multilayer film and a product. The product may be a snack or confection item. The package may essentially consist of or consists of one or more embodiments of the compostable high barrier film. The package may be sealed and formed into a pouch or bag.

BRIEF DESCRIPTION OF THE DRAWINGS

[020] The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings, in which:

[021] FIG. 1 is a cross-sectional view of a compostable high barrier film having comparable thickness to a non-compostable film for use in packaging;

[022] FIG. 2 is a cross-sectional view of a liner film having a sealant structure for forming the compostable high barrier film;

[023] FIG. 3 is a cross-sectional view of a compostable outer film prior to lamination to form the compostable high barrier film;

[024] FIG. 4 is a cross-sectional view of the intermediate film structure of a compostable high barrier film with the compostable outer film and liner film laminated together and prior to delamination of the sealant structure;

[025] FIG. 5 is a diagram of the processing steps to form the compostable high barrier film, according to the present disclosure; and

[026] FIG. 6 is an exemplary package constructed from the compostable high barrier film, according to the present disclosure.

[027] The drawings show some but not all embodiments. The elements depicted in the drawings are illustrative and not necessarily to scale, and the same (or similar) reference numbers denote the same (or similar) features throughout the drawings.

DETAILED DESCRIPTION

[028] There is a need for an improved compostable high barrier film that delivers excellent barrier properties and is capable of being produced in a thickness comparable to traditional non-compostable films for particular use in packaging snack and confection products. Accordingly, this disclosure provides a compostable structure that can be considered comparable to existing packaging films for these products that are not compostable. The compostable high barrier film is provided in a thickness of about 30 micron (1 .2 mil) and has barrier properties with a WVTR according to ASTM F1249 of about less than ,5g/m²/24 hours at 38°C and 90% relative humidity and an OTR according to ASTM F1927 of about less than .5 cc/m²/24 hours at 23°C and 0% relative humidity to mirror existing non-compostable films used for these product types. Providing an improved compostable structure thickness that is a comparable thickness to traditional BOPP films amounts to a significant cost savings when compared to current known compostable structures. Currently, the compostable resins used to make compostable films are approximately three times more costly and approximately 30% heavier when compared to polyolefins. Therefore, by improving the composition to provide a high barrier but thin sealant structure, a significant cost savings can be had when compared to existing compostable structures.

[029] The compostable high barrier films for packaging disclosed herein include a compostable outer film defining a first exterior surface, a sealing layer defining a second exterior surface, a barrier layer positioned between the sealing layer and the compostable outer film, and an adhesive layer between the barrier layer and the compostable outer film. A first embodiment of a compostable high barrier film 10 for packaging is shown in FIG. 1 comprising a compostable outer film 12 having a first exterior surface 13 and an interior non-exposed surface 15. The non-exposed surface 15 of the compostable outer film 20 is secured with an adhesive layer 16 to a barrier layer 18 formed on a non-exposed surface 17 of a sealing layer 20. The sealing layer 20 further defines a second exterior surface 21 . Also shown is a printed indica layer 14 that may be printed on the interior non-exposed surface 15 of the compostable high barrier film 10. The compostable high barrier film 10 of FIG. 1 is formed from the lamination of a pair of separate film structures 30, 40, shown in FIGS. 2-3, wherein FIG. 2 shows a sealant structure 31 that is produced from a coextruded film structure 30 and laminated with adhesive layer 16 to a compostable outer film structure 40 shown in FIG. 3 forming a composite laminate 60 of FIG. 4 that is later deconstructed to form the compostable high barrier film 10 of FIG. 1.

[030] As used herein, the term “compostable” refers to materials such as polymers, layers, films, or packages that are able to disintegrate and biodegrade at industrial and home composting conditions (12 weeks at 58°C or 26 weeks at 21 °C, respectively) and fulfill industrial compostable standards such as EN 13432-2000, ASTM D6400 “Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities” or ASTM D6868 “Standard Specification for Labeling of End Items that Incorporate Plastics and Polymers as Coatings or Additives with Paper and Other Substrates Designed to be Aerobically Composted in Municipal or Industrial Facilities”, and home compostable standards such as AS-5810- 2010 NF T51800, among others.

[031 ] The term "adhesive layer” refers to a layer or material placed on one or more layers or films to promote the adhesion of that layer or film to another surface. For example, adhesive layers may be positioned between two layers of a multilayer film to maintain the two layers in position relative to each other and prevent undesirable delamination. In another example, adhesive layers may be positioned between two films of a laminate to maintain the two layers in position relative to each other and prevent undesirable delamination. As used herein, layers or films that are “in direct contact with” or “are directly adjacent to” each other have no intervening material between them.

[032] Some embodiments of the compostable multilayer film may have one or more adhesive layers that are made of a compostable adhesive applied by an adhesive lamination process. Commercially available compostable adhesives may be solvent-based, solvent-free or water-based. Commercially available adhesives may have base reactive chemistry of isocyanate. Alternatively, the films and layers of the compostable high barrier film may be connected to one another by other means such as extrusion lamination, using an extruded polymer for bonding, coextrusion, or thermal lamination.

[033] The term "layer", as used herein, refers to a building block of a film or laminate that is a structure of a single material type, a homogeneous blend of materials, or a dispersion blend of materials. A layer may be a single polymer, a blend of materials within a single polymer type or a blend of various polymers, may contain metallic materials, and may have additives. Layers may be continuous with the film (i.e., coextensive with the film) or may be discontinuous or patterned. A layer has an insignificant thickness (z direction) as compared to the length and width (x-y direction), and therefore is defined to have two major surfaces, the area of which are defined by the length and width of the layer. An exterior layer is one that is connected to another layer at only one of the major layer surfaces. In other words, one major surface of an exterior layer is exposed. An interior layer is one that is connected to another layer at both major surfaces. In other words, an interior layer is between two other layers. A layer may have sub-layers.

[034] Similarly, the term “film”, as used herein, refers to a web built of layers and/or films, all of which are directly adjacent to and connected to each other. A film can be described as having a thickness that is insignificant as compared to the length and width of the film. Films are generally regarded as having two major surfaces, opposite each other, expanding in the length and width directions. As used herein, a “laminate” is a film that may be built from an unlimited number of films and/or layers, the films and/or layers being bonded together by any known process such as, but not limited to, coextrusion, coating or laminating, to form a composite article.

[035] As used herein, the term “exterior layer”, “exterior film”, “skin layer”, “surface layer” or “surface film” is used to describe a film or layer that is located on one of the major surfaces of the film or laminate in which it is comprised. As used herein, the term “interior layer” or “interior film” is used to describe a film or layer that is not located on the surface of the film in which it is comprised. An interior film or layer is adjacent to another film or layer on both sides.

[036] As shown in FIG. 1 , this embodiment and other embodiments of the compostable high barrier film 10 may include printed indicia layers 14 (i.e., ink layers, graphics layers, print layers). Printed indicia may be applied to one or both surfaces of one or more films of the compostable high barrier film 10.

The printed indicia layer 14 may be applied by any printing process, such as but not limited to flexographic printing, rotogravure printing, or digital printing. The printed indicia layer 14 may be comprised of inks that are compostable. The printed indicia layer 14 may be coextensive with the compostable high barrier film 10 (100 % coverage) or may be patterned. The printed indicia layer 14 may include multiple colors that are layered upon each other. If the printed indicia layer 14 is located on an exterior surface of the compostable high barrier film 10, the printed indicia layer 14 may include a clear over lacquer having the function of heat resistance and/or scuff protection. The printed indicia layer 14 may only consist of a heat resistant over lacquer.

[037] The compostable high barrier films 10 disclosed herein are able to fulfill industrial compostable standards such as EN 13432-2000, ASTM D6400 “Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities” or ASTM D6868 “Standard Specification for Labeling of End Items that Incorporate Plastics and Polymers as Coatings or Additives with Paper and Other Substrates Designed to be Aerobically Composted in Municipal or Industrial Facilities”, and home compostable standards such as AS-5810-2010 NF T51800, among others.

[038] In some embodiments of the compostable high barrier film 10, each layer, except the barrier layer 18, when comprising a vapor deposited metal layer as the barrier component, contains a compostable material.

[039] Some embodiments of the compostable high barrier film 10 may include additional films and/or layers. For example, the compostable high barrier film 10 may contain a thin primer layer. The compostable high barrier film 10 may include other functional layers such as tie layers or moisture barrier layers. Additional layers should be minimized such that they do not disrupt the mechanical performance and/or composting performance of the compostable high barrier film 10.

[040] COMPOSTABLE OUTER FILM

[041] The compostable outer film 12 may serve as a printable web, able to carry the printed indicia 14 if required for the packaging application. As is shown in FIG. 3, the compostable outer film 12 serves as the exterior surface 13 of the packaging, wherein the compostable outer film 12 is provided in a compostable film structure 40. In some embodiments, the compostable outer film 12 may be made out of a polylactic acid (PLA) polymer, amorphous polylactic acid (aPLA), polybutylene adipate terephthalate (PBAT) polymer, polybutylene succinate (PBS) polymer, polyhydroxyalkanoates (PHAs), polyhydoxybutyrate (PHB), 4-hydroxybenzoate hydroxylase (PHBH), cellulose, cellulose acetate (CA), poly(vinyl alcohol) (PVOH), a cellophane, a compostable paper, or combinations thereof.

[042] Other embodiments of the compostable outer film 12 are PLA films, or films that contain one or more PLA layers. A PLA layer of a PLA film may contain greater than 50% PLA polymer, greater than 75% PLA polymer or greater than 95% PLA polymer, by weight. In some embodiments, the compostable outer film 12 is free from paper and cellulose. In some embodiments the compostable outer film 12 is multilayered and comprised of layers of PLA and PBAT, such as a structure of PLA / PBAT / PLA.

[043] The compostable outer film 12 is a machine direction oriented film (MDO), or a blown film, or a cast film. To comport with the goal of providing the compostable high barrier film 10 for packaging that is comparable to existing films, the thickness of the compostable outer film 12 is of about 1 .0 mil (25.4 micron). In an embodiment of the compostable high barrier film 10, the compostable outer film 12 is a multilayered blown film comprised of a core layer of PBAT and skin layers of PLA in a composition of about 10% by weight of PLA in the skin layers and 80% by weight of PBAT in the core layer. More specifically, the compostable outer film 12 is a multilayered blown film comprised of a core layer of PBAT and skin layers of PLA in a composition of about 8% by weight of PLA in the skin layers and 84% by weight of PBAT in the core layer. This composition of the compostable outer film 12 with PLA on the outer layers and PBAT in the core provides blown processability due to its low modulus when combined with the stiff PLA. This construction Stiff / Soft / Stiff allows the use of the I-Beam effect producing a film with higher bending stiffness.

[044] Alternately, the compostable outer film 12, when produced as a blown film, can be produced by collapsing a blown tube resulting in a multilayered film with layered construction comprising A / B / C / C / B / A with the A and C layers comprising PLA and the B layer comprising PBAT. This alternate compostable outer film 12 would have a composition comprising of about 5% by weight of PLA and of about 40% PBAT in a corresponding structure by weight of 5% PLA / 40% PBAT /5% PLA / 5% PLA / 40% PBAT / 5% PLA. More specifically, this layered composition of the compostable outer film 12 may have a composition comprising of about 4% PLA / 42% PBAT / 4% PLA / 4% PLA / 42% PBAT / 4% PLA.

[045] In an alternate embodiment, the compostable outer film 12 is a blown multilayered film comprising a PBS based structure. This embodiment is a multilayered blown film comprised of a core layer of PBS and skin layers of PBS in a composition of about 15% by weight of PBS in the skin layers and 70% by weight of PBS in the core layer. When constructed of a layered PBS based structure, the compostable outer film 12 may include an anti-oxidant to avoid gel formation and improve processibility.

[046] As used herein, “skin layer” refers to a layer of a film that is necessarily located at the surface of the film. By this definition, a film has two skin layers and all other layers that may be present within the film are between the skin layers. If a film is a monolayer film, that single layer is a skin layer, occupying both surfaces of the film.

[047] As used herein, “PLA polymer” or “PLA” is a compostable polymer based on polylactic acid. Commercial examples of PLA polymers are available from Total Corbion and NatureWorks. A layer of a film that comprises PLA may include at least 50 %, at least 75 % or at least 95 % PLA polymer, by weight.

[048] As used herein, “PBAT polymer” or “PBAT” is a compostable biopolymer based on poly(butylene adipate-co-terephthalate). Commercial examples of PBAT biopolymers are available from many suppliers, including but not limited to Mitsubishi, Novamont, Jiangsu Torise Biomaterials Co., and BASF. A layer of a film that comprises PBAT polymer may include at least 50 %, at least 75 % or at least 95 % PBAT polymer, by weight.

[049] SEALANT STRUCTURE

[050] The compostable high barrier film 10 including the barrier layer 18 and the sealing layer 20 provides a thin and compostable structure that can be utilized to form a package, wherein the sealing layer 20 is utilized to both form and secure an opening of the package and provide a suitably compatible substrate to receive the material composition of the barrier layer 18 to provide a barrier that is considered to have high barrier properties. As is shown in FIG. 2, the sealant structure 31 is provided in multiple layers on the film structure 30 and preferably formed through a coextrusion process. The sealant structure 31 includes the barrier layer 18, the sealing layer 20, and a delamination layer 22, with the sealant structure 31 being formed upon a coextruded film 24.

[051 ] The sealing layer 20 comprises compostable resins and other resins (ensuring that compostability limit requirements are fulfilled) selected from the group comprising at least an amorphous polylactic acid (aPLA), polybutylene adipate terephthalate (PBAT) polymer, polybutylene succinate (PBS) polymer, polyhydroxyalkanoates (PHAs), 4-hydroxybenzoate hydroxylase (PHBH), polylactic acid (PLA) polymer, polyhydoxybutyrate (PHB), butanediol vinyl alcohol copolymer (BVOH), such as G-Polymer™ amorphous vinyl alcohol resin produced by Mitsubishi Chemical Group, ethylene vinyl alcohol copolymer (EVOH), ethylene vinyl acetate (EVA), cyclic olefin copolymer (COC), or combinations thereof.

[052] To be provided in a desired thickness of about 2 micron to 15 micron, the sealing layer 20 is formed upon the coextruded film 24, either blown or cast, and often referred to herein as a liner or a liner film. The construction of this liner film structure 30 comprising the selected combination of materials is based upon the distinct chemical composition of each of the distinct layer types, wherein the delamination layer 22 composition is selected to bond tightly to the coextruded film 24, but only slightly to the sealing layer 20 (slight being below 30gf/in when subjected to a bond strength test, such as ASTM F 904) to allow for processing and application of the barrier layer 18 upon the non-exposed surface 17 of the sealing layer 20.

[053] The coextruded film 24 functioning as the liner can be formed from any polyolefin based polymer. The sealant structure 31 comprises at least the delamination layer 22 and the sealing layer 20 with each of the delamination layer 22 and the sealing layer 20 being coextruded along with the coextruded film 24. In some embodiments the coextruded film 24 is a polyethylene (PE) based film having a thickness of about 38.1 micron (1 .5 mil). This PE based film may be a multilayered film. In some embodiments the delamination layer 22 is comprised of EVA having a thickness of about 7.62 micron (0.3 mil). In some embodiments the sealing layer 20 is comprised of aPLA in a thickness of about 5.08 micron (0.2 mil). In some embodiments the sealing layer 20 is comprised of a layer of aPLA in a thickness of about 2.54 micron (0.1 mil) and a layer of BVOH in a thickness of about 2.54 micron (0.1 mil). The construction of this liner film structure 30 comprising the selected combination of materials is based upon the distinct chemical composition of each of the distinct layer types to compart with the ability of the material to selectively adhere to certain material types, but only slightly to other material types.

[054] As used herein, “BVOH polymer” or “BVOH” is a compostable butenediol vinyl alcohol copolymer such as Nichigo G-Polymer ™ grades available from Soarus. A layer of a film that comprises BVOH polymer may include at least 50%, at least 75% or at least 95% BVOH polymer, by weight.

[055] An embodiment of film structure 30 when comprising EVA in the delamination layer 22 bonds tightly to the coextruded film 24 when comprising PE, but only slightly to the sealing layer 20 when comprising aPLA. However slight, the bond strength between the delamination layer 22 comprising EVA and the sealing layer 20 comprising aPLA is strong enough to avoid delamination during the addition of barrier processing and lamination to the compostable film structure 40 to produce the resultant compostable high barrier film 10. Accordingly, the delamination layer 22 of the sealant structure 31 could be any incompatible polyolefin chemically modified to promote slight adhesion to avoid premature delamination during conversion. Further, the components of the coextruded film 24 are utilized to provide a generally less stiff surface when compared to traditional bi-oriented compostable materials; this less stiff property reduces noise of the film during use and allows for a more consistent and effective sealing layer and barrier layer.

[056] The sealing layer 20 comprising aPLA is selected for its affinity to receive a suitable high barrier material for the barrier layer 18. This barrier layer 18 may be a metalized or metal layer, such as, but not limited to, a vacuum deposited or vapor deposited metal layer of aluminum. Alternate to a metal layer, the barrier layer 18 can be an inorganic deposition, such as oxides of silicon (SiOx) or aluminum (AIOx) that is liquid coated, vacuum coated, or otherwise deposited for forming the barrier layer. Accordingly, the barrier layer 18 may be a vacuum deposited barrier layer. The barrier layer 18 may be deposited by way of an atmospheric atomic layer deposition. In some embodiments, when the barrier layer 18 is a metal layer, it has been produced by two passes through a vacuum metalizing process. Typically, the barrier layer 18 is a vapor deposited metal layer that is an aluminum metal or an alloy thereof. The thickness of this metal layer is between about 3.5 nm and 100 nm. The metal layer may be deposited onto the aPLA layer or BVOH layer (i.e., the metal is in direct contact with the aPLA layer or BVOH layer) of the coextruded film. The metal layer is continuous with the coextruded film 24 sealing layer 20 and the resultant compostable high barrier film 10.

[057] The barrier layer 18 provides moisture and/or oxygen barrier properties to the compostable high barrier film 10. The barrier layer 18, when formed upon the non-exposed surface 17 of the sealing layer 20, allows the high barrier film 10 to have an optical density (OD) of about greater than 3.0 or of about greater than 4.5, a water vapor transmission rate (WVTR) according to ASTM F1249 of about less than 0.5g/m²/24 hours at 38°C and 90% relative humidity, and an oxygen gas transmission rate (OTR) according to ASTM D3985 of about less than 0.5 cc/m²/24 hours at 23°C and 0% relative humidity. To further ensure a proper barrier, when a metalized barrier layer 18 is utilized, the adhesion between the metal and sealing layer 20 non exposed surface 17 is at least of about 400 gf/in according to ASTM F904 for the bond strength of laminates.

[058] To produce the resultant high barrier film 10, a method of construction is provided through various processing steps (FIG. 5) which are utilized to form composite laminate structure 60 of FIG. 4, wherein the barrier layer 18 of film structure 30 is adhesively secured to at least the non-exposed surface 15 of compostable film 12 through adhesive layer 16. In FIG. 5, a process in the form of a method of construction 100 for forming the high barrier film 10 is shown in diagrammatic steps. Accordingly, the high barrier film 10 construction begins with the formation of film structure 30 (FIG. 2) at step 101 , wherein coextruded film 24 is formed in a multilayered structure with at least the delamination layer 22 and the sealing layer 20. The formation step 101 may be a blown coextrusion of the coextruded film 24 being polyolefynic and having a thickness of about 1 .5 mil, the delamination layer 22 being EVA in a thickness of about 0.3 mil, and the sealing layer 20 being aPLA in a thickness of about 0.2 mil and having the exposed surface 21 adjacent the delamination layer 22 and the non-exposed surface 17 being an intermediate exposed surface for later receipt of the barrier coating 18 at step 102. Alternately, the sealing layer 20 and delamination layer 22 could be comprised of different materials having properties as outlined above, wherein the delamination layer 22 bonds tightly to the coextruded film 24 but only slightly to the sealing layer 20.

[059] Step 102 commences when film structure 30 is subjected to the application of the barrier layer 18. The barrier layer 18 being applied to the non-exposed surface 17. The barrier layer 18 is a vacuum deposited metalized layer of aluminum, although other barrier materials could be utilized, such as, but not limited to, aluminum oxides, silicon oxides, and other inorganic coatings. To ensure a robust barrier when metalized, the nonexposed surface 17 may be subjected to multiple passes, such as two passes of metallization to form the barrier layer 18. After application of the barrier layer 18, the process continues at step 103 where film structure 30 (FIG. 2) in the form of the liner is laminated to film structure 40 (FIG. 3) comprising at least the compostable outer film 12.

[060] Step 103 produces composite film structure 60 (FIG. 4) though the addition of the adhesive layer 16 between the barrier layer 18 and compostable outer film 12, wherein film structure 40 is adhesively laminated to film structure 30. If printed indica 14 is provided on the compostable outer film 12, the adhesive layer 16 will be between the barrier layer 18 and the printed indica 14. After lamination of the pair of film structures 30, 40 to form composite film structure 60 the resultant compostable high barrier film 10 is formed after additional processing at step 104.

[061 ] Processing step 104 forms the final compostable high barrier film 10 through the separation of delamination layer 22 from sealant structure 31 and exposing the second exterior surface 21 of sealing layer 20. Accordingly, processing step 104 takes advantage of the material properties of the delamination layer 22 and sealing layer 20 slight adhesion (approximately of about 30 gf/in. peel strength) to allow for removal of the liner film coextruded film 24 and delamination layer 22. Processing step 104 may utilize a rewinder to rewind the liner portion, wherein a peel will be propagated within the composite film structure 60 at the delamination layer 22 to separate the resultant compostable high barrier film 10 from the liner. This rewound liner material, as it is primarily polyolefin based, can be easily reused in additional applications.

[062] After the completion of step 104, the compostable high barrier film 10 is finally provided at step 105, wherein the resulting structure presents a compostable structure having high barrier properties in a thickness that is comparable to existing non compostable structures.

[063] PACKAGED PRODUCT

[064] Referring to FIG. 6, the resultant high barrier film 10 can be utilized in package 50. The term “package” is used herein to describe an article that may house an object (i.e., a product), the article formed by bonding one or more compostable high barrier films or other packaging components to itself or each other around a periphery, thus forming a package interior space. A “packaged product” refers to the one or more packaging components forming a hermetically sealed package and the product therein. As used herein, hermeticity refers to a seal or sealed package that is completely closed and essentially airtight. Hermetically sealed packages generally have a need for storage and package integrity over a period that is greater than a few days. Package integrity includes a consistent appearance, maintenance of barrier properties, maintenance of lamination bonds, and maintenance of seals.

[065] The product may be any type of food, beverage, pharmaceutical or other medical aid, nutraceutical, consumer good or industrial good. Examples of products include, but are not limited to, chips, candies, snacks, nuts, confections, crisps, crackers, and combinations of these.

[066] The packaged products disclosed herein include a package 50 formed from at least one compostable high barrier film 10 and optionally other components. In some embodiments of the packaged product 50, the entire package is formed from a single compostable high barrier film 10 that has been folded over and sealed to itself (i.e., bag, chip bag, chip package, pouch), such as, but not limited to, fin seals and lap seals as shown in FIG. 6. In some embodiments of the packaged product, the compostable high barrier film is sealed to another compostable high barrier film (i.e., a sachet configuration). Packages that include components that are not according to the compostable high barrier films disclosed herein may also be compostable, such that the entire package is compostable. In some embodiments, the package includes components that are not compostable but can be separated from the portions that are compostable for proper disposal.

[067] In each of the packaged products, the first exterior surface 13 of the compostable high barrier film 10 is facing away from the product, exposed to the outside environment, and the second exterior surface of the compostable high barrier film is facing toward the product, exposed to the product and the internal environment.

[068] The packaged products disclosed herein advantageously include a compostable package and/or a compostable high barrier film which may allow the product to have a shelf-life of up to one week, up to two weeks, up to one month, up to two months, up to three months, up to 4 months, up to 5 months, up to 6 months, up to 7 months, up to 8 months, up to 9 months, up to 10 months, up to 11 months or up to 12 months. The shelf-life is dependent upon one or more variables including: the product packaged, the storage conditions of the packaged product and the barrier of the packaging components. The compostable high barrier films disclosed have the surprising combination of compostability and maintenance of the barrier over the shelf-life of the product. As used herein, the shelf-life of a packaged product is the time period in which the product maintains quality (i.e., taste and appearance) acceptable for consumer use. The shelf-life may be determined due to degradation of product color, taste or suitability for consumption (i.e., microbial growth).

[069] EXAM P LES AN D DATA

[070] Exemplary compostable blown films produced having structures according to Table 1 provide a compostable structure that can be considered to have high barrier properties. These are compostable blown structures having an A/B/C layered composition comprising: A) a sealant layer; B) a core layer; and C) a surface layer specifically adapted to receive a barrier, such as a metalized layer, [sealant / core / layer to receive barrier]. The weight percentage of these layers may be [10% / 80% / 10%]. These exemplary structures provide an optical density greater then about 4.5, WVTR less than about 0.3 g/m²/24hrs. (38°C, 90% R.H.), and an OTR less than about 0.5 cc/m²/24hrs. (23°C; 0% R.H.). For some samples to reach an optical density greater than about 4.5 two passes of metalization are required. Each film component (i.e., A1 , B1 , etc.) are according to: [071 ] A1 = aPLA or PBAT. The aPLA being an amorphous polylactic acid polymer having a density of 1 .24 g/cm³, such as 4060-D by NatureWorks®. PBAT being a poly(butylene adipate-co-terephthalate) polymer having a density of 1 .25-1 .27 g/cm³, such as ecoflex® C1200 by BASF.

[072] B1 = PBAT or PBS or PHA or PHBH. The PBAT being a poly(butylene adipate-co-terephthalate) polymer having a density of 1 .25-1 .27 g/cm³, such as ecoflex® C1200 by BASF. The PBS being a bio-based polybutylene succinate polymer having a density of 1 .26 g/cm³, such as BioPBS™ FZ91 PM by PTTMCC or FD92PM PTTMCC having a density of 1 .24 g/cm³ or a layered composition of both. The PHA being a biosynthesized polyhydoxyalkanoate, such as Nodax® 2198 by Danimer. The PHBH being a 4-hydroxybenzoate hydroxylase having a density of about 1 .19 to 1 .20 g/cm³, such as X071 by Kaneka.

[073] C1 = aPLA. The aPLA being an amorphous polylactic acid polymer having a density of 1 .24 g/cm³, such as 4060-D by NatureWorks®.

[074] A2 = aPLA or PBAT. The aPLA being an amorphous polylactic acid polymer having a density of 1 .24 g/cm³, such as 4060-D by NatureWorks®. PBAT being a poly(butylene adipate-co-terephthalate) polymer having a density of 1 .25-1 .27 g/cm³, such as ecoflex® C1200 by BASF.

[075] B2 = PBAT or PBS or PHA or PHBH. The PBAT being a poly(butylene adipate-co-terephthalate) polymer having a density of 1 .25-1 .27 g/cm³, such as ecoflex® C1200 by BASF. The PBS being a bio-based polybutylene succinate polymer having a density of 1 .26 g/cm³, such as BioPBS™ FZ91 PM by PTTMCC or FD92PM PTTMCC having a density of 1 .24 g/cm³ or a layered composition of both. The PHA being a biosynthesized polyhydoxyalkanoate, such as Nodax® 2198 by Danimer. The PHBH being a 4-hydroxybenzoate hydroxylase having a density of about 1 .19 to 1 .20 g/cm³, such as X071 by Kaneka.

[076] C2 = G-Pol or G-Pol (BVOH) with EVOH blends. G-Pol being G- Polymer™ amorphous vinyl alcohol resin produced by Mitsubishi Chemical Group. EVOH being ethylene vinyl alcohol copolymer. When a blend is utilized, the blend is of about 70% G-Pol and 30% EVOH by weight %. Table 1 : Structures and Components of Example Films

[077] To provide a thin compostable high barrier laminated structure, according to the present disclosure, the sealant structure is produced on the coextruded film described herein as the liner. An exemplary blown or cast liner film is produced with a structure according to Table 2. This liner film of Table 2 is laminated to the compostable film and deconstructed to form the high barrier compostable film. The aPLA being an amorphous polylactic acid polymer having a density of 1 .24 g/cm³ and forming the sealant layer to receive the barrier coating. The EVA being ethylene vinyl acetate copolymer having a density of 0.93 g/cm³ containing 12% by weight Vinyl Acetate comonomer content and forming a delamination layer.

Table 2: Structure of Liner Film with Sealant Structure

[078] In an alternate embodiment, the sealant structure is produced from a combination of BVOH and aPLA or BVOH and PBAT on the coextruded film described herein as the liner. An exemplary blown or cast liner film is produced with a structure according to Table 3. This liner film of Table 3 is laminated to the compostable film and deconstructed to form the high barrier compostable film. The aPLA being an amorphous polylactic acid polymer having a density of 1 .24 g/cm³. The EVA being ethylene vinyl acetate copolymer having a density of 0.93 g/cm³, such as ELVAX™ 3135XZ by Dow Chemical. The BVOH being G-Polymer™ amorphous vinyl alcohol resin produced by Mitsubishi Chemical Group.

Table 3: Structure of Liner Film with Alternate Sealant Structure

[079] COMPOSTABLE HIGH BARRIER FILM EMBODIMENTS

[080] Embodiment A. A compostable packaging film displaying high barrier properties comprising:

[081 ] a compostable outer film defining a first exterior surface of the compostable packaging film;

[082] a sealing layer defining a second exterior surface of the compostable packaging film, the sealing layer having a sealing layer thickness in a range from about 2 micron to 15 micron;

[083] a vacuum deposited barrier layer, the vacuum deposited barrier layer positioned between the compostable outer film and the sealing layer; and

[084] an adhesive layer, the adhesive layer positioned between the vacuum deposited barrier layer and the compostable outer film;

[085] wherein the compostable packaging film comprises a thickness in the range from about 20 micron to 50 micron.

[086] Embodiment B. The compostable packaging film displaying high barrier properties according to Embodiment A, wherein the compostable outer film has a thickness in a range from about 10 micron to 40 micron or from about 15 micron to 30 micron.

[087] Embodiment C. The compostable packaging film displaying high barrier properties according to Embodiment A, wherein the compostable packaging film has a water vapor transmission rate (WVTR) according to ASTM F1249 of less than 0.5g/m²/24 hours at 38°C and 90% relative humidity and an oxygen transmission rate (OTR) according to ASTM F1927 of about less than 0.5 cc/m²/24 hours at 23°C and 0% relative humidity.

[088] Embodiment D. The compostable packaging film displaying high barrier properties according to Embodiment A wherein the sealing layer comprises a compostable polymer.

[089] Embodiment E. The compostable packaging film displaying high barrier properties according to Embodiment A wherein the sealing layer comprises one or more of an amorphous polylactic acid polymer (aPLA), a polyhydroxyalkanoate polymer (PHA), a vinyl alcohol copolymer, a cyclic olefin copolymer, a polyethylene (metallocene) or blends thereof.

[090] Embodiment F. The compostable packaging film displaying high barrier properties according to Embodiment A further comprising a printed indica layer located on a non-exposed surface of the compostable outer film.

[091] Embodiment G. The compostable packaging film displaying high barrier properties according to Embodiment A wherein the compostable outer film is oriented.

[092] Embodiment H. The compostable packaging film displaying high barrier properties according to Embodiment A wherein the compostable outer film comprises at least one of a polylactic acid polymer (PLA), a polyhydroxyalkanoate polymer (PHA), a polybutylene adipate terephthalate polymer (PBAT), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), a cellophane, a compostable paper or a cellulose acetate.

[093] Embodiment I. A thin compostable packaging film displaying high barrier properties comprising:

[094] a compostable outer film having an exposed side and a non-exposed side, the exposed side located at a first exterior surface of the compostable packaging film;

[095] a sealing layer comprising a compostable polymer and located at a second exterior surface of the compostable packaging film;

[096] a barrier layer located on the sealing layer opposite the second exterior surface at a non-exposed surface of the sealing layer;

[097] a printed indicia layer on the non-exposed side of the compostable outer film; and [098] an adhesive layer bonding the barrier layer to the printed indica layer;

[099] wherein the compostable packaging film displaying high barrier properties comprises a thickness of from about 20 micron to 50 micron.

[100] Embodiment J. The thin compostable packaging film displaying high barrier properties of Embodiment I wherein the sealing layer has a sealing layer thickness in a range from about 2 micron to 10 micron.

[101 ] Embodiment K. The thin compostable packaging film displaying high barrier properties of Embodiment I wherein the barrier layer is a vacuum deposited metal layer.

[102] Embodiment L. The thin compostable packaging film displaying high barrier properties of Embodiment I wherein the compostable polymer of the sealing layer is an amorphous polylactic acid polymer (aPLA), a poly(vinyl alcohol) (PVOH), a butanediol vinyl alcohol copolymer (BVOH), or combinations thereof.

[103] EMBODIMENTS RELATED TO A METHOD OF MANUFACTURE FOR A COMPOSTABLE HIGH BARRIER FILM

[104] Embodiment M. A method of producing a compostable packaging film comprising the steps of:

[105] providing a multilayer film comprising one or more base layers and a sealing layer, the sealing layer having an exposed surface;

[106] coating the exposed surface of the sealing layer of the multilayer film with a vacuum deposited barrier layer by a vacuum deposition process to produce a multilayer barrier film;

[107] attaching a compostable outer film to the vacuum deposited barrier layer of the multilayer barrier film by an adhesive lamination process to produce an intermediate structure; and

[108] removing the one or more base layers from the intermediate structure to yield the compostable packaging film comprising the compostable outer film, the vacuum deposited barrier layer, and the sealing layer;

[109] wherein the compostable outer film is located at a first exterior surface of the compostable packaging film and the sealing layer is located at a second exterior surface of the compostable packaging film. [1 10] Embodiment N. The method of manufacturing a compostable high barrier film of Embodiment M, wherein the sealing layer comprises a sealing layer thickness in a range from about 2 micron to 10 micron.

[1 11 ] Embodiment O. The method of manufacturing a compostable high barrier film of Embodiment M, wherein the compostable high barrier packaging film comprises a thickness of from about 25 micron to 40 micron.

[1 12] Embodiment P. The method of manufacturing a compostable high barrier film of Embodiment M, wherein a single transfer operation comprises attaching the compostable outer film to the vacuum deposited barrier layer of the multilayer barrier film and removing the one or more base layers from the intermediate structure.

[1 13] Embodiment Q. The method of manufacturing a compostable high barrier film of Embodiment M, wherein the one or more base layers comprises a delamination layer in direct contact with the sealing layer and the step of removing the one or more base layers from the intermediate structure comprises separation of the delamination layer from the sealing layer.

[114] Embodiment R. The method of manufacturing a compostable high barrier film of Embodiment Q, wherein the delamination layer comprises an incompatible polyolefin chemically modified to promote slight adhesion to avoid premature delamination during conversion.

[1 15] Embodiment S. The method of manufacturing a compostable high barrier film of Embodiment R, wherein the delamination layer comprises an ethylene vinyl acetate polymer.

[1 16] Embodiment T. The method of manufacturing a compostable high barrier film of Embodiment M, wherein the coating step comprises application of aluminum in a vacuum metallizer resulting in a multilayer barrier film having an optical density in the range of from 4.5 to 6.0, a water vapor transmission rate (WVTR) according to ASTM F1249 of less than 0.5g/m²/24 hours at 38°C and 90% relative humidity, an optical density greater then about 3.0, and metal adhesion higher than about 400gf/in.

[1 17] Embodiment U. The method of manufacturing a compostable high barrier film of Embodiment M, wherein the sealing layer comprises an amorphous polylactic acid polymer (aPLA), a poly(vinyl alcohol) (PVOH), a butanediol vinyl alcohol copolymer (BVOH), or combinations thereof. [118] Embodiment V. The method of manufacturing a compostable high barrier film of Embodiment M, further comprising a step of printing a printed indicia layer on the compostable outer film prior to the step of attaching the compostable outer film to the vacuum deposited layer of the multilayer barrier film.

Claims

CLAIMS What is claimed is:

1 . A compostable packaging film displaying high barrier properties, the compostable packaging film comprising: a compostable outer film defining a first exterior surface of the compostable packaging film; a sealing layer defining a second exterior surface of the compostable packaging film, the sealing layer having a sealing layer thickness in a range from about 2 micron to 15 micron; a vacuum deposited barrier layer, the vacuum deposited barrier layer positioned between the compostable outer film and the sealing layer; and an adhesive layer, the adhesive layer positioned between the vacuum deposited barrier layer and the compostable outer film; wherein the compostable packaging film comprises a thickness in the range of from 20 micron to 50 micron.

2. The compostable packaging film of claim 1 , wherein the compostable outer film has a thickness in a range from about 10 micron to 40 micron or from about 15 micron to 30 micron.

3. The compostable packaging film of claim 1 , wherein the compostable packaging film has a water vapor transmission rate (WVTR) according to ASTM F1249 of less than 0.5g/m²/24 hours at 38°C and 90% relative humidity and an oxygen transmission rate (OTR) according to ASTM F1927 of about less than 0.5 cc/m²/24 hours at 23°C and 0% relative humidity.

4. The compostable packaging film of claim 1 , wherein the sealing layer comprises a compostable polymer.

5. The compostable packaging film of claim 1 , wherein the sealing layer comprises one or more of an amorphous polylactic acid polymer (aPLA), a polyhydroxyalkanoate polymer (PHA), a vinyl alcohol copolymer, a cyclic olefin copolymer, a polyethylene (metallocene) or blends thereof.

6. The compostable packaging film of claim 1 , further comprising a printed indicia layer located on a non-exposed surface of the compostable outer film.

7. The compostable packaging film of claim 1 , wherein the compostable outer film is oriented.

8. The compostable packaging film of claim 1 , wherein the compostable outer film comprises at least one of a polylactic acid polymer (PLA), a polyhydroxyalkanoate polymer (PHA), a polybutylene adipate terephthalate polymer (PBAT), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), a cellophane, a compostable paper or a cellulose acetate.

9. A thin compostable packaging film displaying high barrier properties, the thin compostable packaging film comprising: a compostable outer film having an exposed side and a non-exposed side, the exposed side located at a first exterior surface of the compostable packaging film; a sealing layer, the sealing layer comprising a compostable polymer and located at a second exterior surface of the compostable packaging film; a barrier layer, the barrier layer located on the sealing layer opposite the second exterior surface at a non-exposed surface of the sealing layer; a printed indicia layer, the printed indicia layer on the non-exposed side of the compostable outer film; and an adhesive layer, the adhesive layer bonding the barrier layer to the printed indicia layer; wherein the compostable packaging film comprises a thickness in the range of from about 20 micron to 50 micron.

10. The compostable packaging film of claim 9, wherein the sealing layer has a sealing layer thickness in a range of about from 2 micron to 10 micron.

1 1 . The compostable packaging film of claim 10, wherein the barrier layer is a vacuum deposited metal layer.

12. The compostable packaging film of claim 10, wherein the compostable polymer of the sealing layer is an amorphous polylactic acid polymer (aPLA), a poly(vinyl alcohol) (PVOH), a butanediol vinyl alcohol copolymer (BVOH), or combinations thereof.

13. A method of producing a compostable high barrier packaging film comprising the steps of: providing a multilayer film comprising one or more base layers and a sealing layer, the sealing layer having an exposed surface; coating the exposed surface of the sealing layer of the multilayer film with a vacuum deposited barrier layer by a vacuum deposition process to produce a multilayer barrier film; attaching a compostable outer film to the vacuum deposited barrier layer of the multilayer barrier film by adhesive lamination process to produce an intermediate structure; and removing the one or more base layers from the intermediate structure to yield the compostable packaging film comprising the compostable outer film, the vacuum deposited barrier layer, and the sealing layer; wherein the compostable outer film is located at a first exterior surface of the compostable packaging film and the sealing layer is located at a second exterior surface of the compostable packaging film.

14. The method of claim 13, wherein the sealing layer comprises a sealing layer thickness in a range of from about 2 micron to 10 micron.

15. The method of claim 13, wherein the compostable high barrier packaging film comprises a thickness of from about 25 micron to 40 micron.

16. The method of claim 13 further comprising a single transfer operation comprising attaching the compostable outer film to the vacuum deposited barrier layer of the multilayer barrier film and removing the one or more base layers from the intermediate structure.

17. The method of claim 13, wherein the one or more base layers comprises a delamination layer in direct contact with the sealing layer and the step of removing the one or more base layers from the intermediate structure comprises separation of the delamination layer from the sealing layer.

18. The method of claim 17, wherein the delamination layer comprises an incompatible polyolefin chemically modified to promote slight adhesion to avoid premature delamination during conversion.

19. The method of claim 18, wherein the delamination layer comprises an ethylene vinyl acetate polymer.

20. The method of claim 13, wherein the coating step comprises application of aluminum in a vacuum metallizer resulting in a multilayer barrier film having an optical density in the range of from 4.5 to 6.0, a water vapor transmission rate (WVTR) according to ASTM F1249 of less than 0.5g/m²/24 hours at 38°C and 90% relative humidity, an optical density greater then about 3.0, and metal adhesion higher than about 400gf/in.

21 . The method of claim 13, wherein the sealing layer comprises an amorphous polylactic acid polymer (aPLA), a poly(vinyl alcohol) (PVOH), a butanediol vinyl alcohol copolymer (BVOH), or combinations thereof.

22. The method of claim 13, further comprising a step of printing a printed indicia layer on the compostable outer film prior to the step of attaching the compostable outer film to the vacuum deposited layer of the multilayer barrier film.