Durable multilayer barrier film structure

Abstract

A foldable packaging film includes a base component, a barrier component, and a polymeric adhesive layer coupling the base component to the barrier component. The barrier component includes a polymeric substrate layer, an inorganic coating layer, and a polymeric buffer layer positioned between the polymeric substrate layer and the inorganic coating layer. The polymeric buffer layer is in direct contact with the inorganic coating layer. The inorganic coating layer includes a wave structure characterized by an average amplitude between 0.05 μm and 1.0 µm and a wavelength between 1.0 μm and 5.0 µm. The polymeric buffer layer has a thickness between 1.0 µm and 5.0 µm that is between 1.05 and 100 times the average amplitude of the wave structure.

Description

[0001] Attorney Docket No. 21406-WO

[0002] DURABLE MULTILAYER BARRIER FILM STRUCTURE

[0003] TECHNICAL FIELD

[0004]

[0001] The present invention is related to durable multilayer foldable packaging film, in particular, flexible multilayer films for durable and foldable packaging applications with barrier properties.

[0005] BACKGROUND

[0006]

[0002] Food products are increasingly being packaged in flexible packages as an alternative to metal cans and glass jars. The packaging material for flexible packages typically includes an embedded barrier layer, an outer polymer layer adhered to one side of the barrier layer and forming the exterior surface of the package, and a heat- sealable inner polymer film layer adhered to the other side of the gas barrier layer and forming the interior surface of the package.

[0007]

[0003] Conventional flexible multilayer barrier packaging films are manufactured with layers of different materials to achieve oxygen, water, bacteria, and flavor barrier properties. One typical option for designing resilient, yet flexible, multilayer packaging barrier films is the use of an aluminum barrier layer of at least 5 pm, preferably more than 12 pm, in thickness. Nevertheless, aluminum is expensive, of high density, subject to pinholes and cracks at lower thicknesses after flexing and has the drawback of opacity. Aluminum is also known to cause problems for reheating a packaged food product in a microwave oven. Moreover, the presence of a metal layer is in general undesirable in terms of recycling possibilities and metal detection within the packaging process.

[0008]

[0004] A typical example of a multilayer packaging barrier film may include a polyethylene terephthalate outer layer, a barrier layer, and an inner sealing layer, where the outer layer in general comprises a printing layer, the barrier layer is a metal foil, a metallized film, or a transparent barrier polymer film and the inner layer is a heat sealable polyolefin layer. The multilayer packaging barrier film may also contain an additional polymer film layer such as a polyamide layer or the like. Attorney Docket No. 21406-WO

[0009]

[0005] Besides the recycling issue, due to the presence of the integrated aluminum foil, the diversity of the polymer layers that can be included in the multilayer packaging barrier film results in an additional problem for rendering this multilayer packaging barrier film recyclable.

[0010]

[0006] For a fiber-based (i.e., cellulose-based or paper-based), foldable multilayer packaging barrier film, a folding process may be required to produce a package that can be hermetically sealed to contain a product (e.g., a food product). Generally, a metal foil (e.g., aluminum foil) may be included in the foldable multilayer packaging barrier film providing barrier and increasing the stiffness of the foldable multilayer packaging barrier film. Thinner aluminum or inorganic oxide coated films may provide barrier protection for packaging films (fiber-based or other); however, these barrier layers are more fragile and may crack upon severe bending or folding of the packaging film. The cracks that form decrease the overall barrier provided.

[0011]

[0007] Without contesting the associated advantages of the state-of-the-art systems, it is nevertheless obvious that there is still a need for a recyclable, durable, and foldable multilayer packaging barrier film, where the foldable multilayer packaging barrier film includes a substantially reduced amount of cracks when undergoing heat treatments and folding processes, thereby limiting the loss of oxygen and water vapor barrier properties of the foldable multilayer packaging barrier film.

[0012] SUMMARY

[0013]

[0008] The present disclosure aims to provide a foldable and durable multilayer packaging barrier film with exceptional retention of barrier properties following a folding process, while preserving or improving recyclability of the foldable multilayer packaging barrier film. The foldable multilayer packaging barrier film includes a base component, which includes a fiber-based (i.e., cellulose-based or paper-based) or a polymer-based material, coupled to a barrier component via a polymeric adhesive layer.

[0014] Advantageously, applying heat while folding the foldable multilayer packaging barrier film that includes a wave structure can result in a substantially reduced amount of cracks in the barrier film compared to barrier films without any wave structure and Attorney Docket No. 21406-WO barrier films with wave structure but folded at room temperature thereby limiting the oxygen and water vapor transmission rates of the foldable multilayer packaging barrier film within a desired range.

[0015]

[0009] The retention of barrier properties in the barrier component can be achieved by coating an inorganic coating layer containing an oxide, such as a metal oxide (e.g., aluminum oxide) or a metalloid oxide (e.g., silicon oxide, silicon being an example metalloid material), on a surface of a polymeric buffer layer with a relatively lower modulus. In the present disclosure, the terms “modulus,” “Young’s modulus,” and “elastic modulus” are used interchangeably. Both the polymeric buffer layer and the inorganic coating layer are coated onto a polymeric substrate layer. The polymeric substrate layer has shrink properties in at least one direction at elevated temperatures. When the barrier component is subject to a heat treatment at a temperature above a shrink onset temperature of the barrier component, a textured wave structure is formed in at least the inorganic coating layer, which has a relatively higher modulus.

[0016] Advantageously, the wave structure allows the barrier component to be folded (or bent) without cracks, especially when folded at an elevated temperature. The wave structure can be generated when the barrier component undergoes a heat treatment. For example, the wave structure can be generated when coupling the base component to the barrier component via an extrusion lamination process. In some instances, the wave structure can be designed with desired directionality and intensity.

[0017]

[0010] In one aspect of the present disclosure, a foldable packaging film includes a base component and a barrier component coupled to the base component. The base component includes a polymeric substrate layer, an inorganic coating layer, and a polymeric buffer layer positioned between the polymeric substrate layer and the inorganic coating layer. The polymeric buffer layer is in direct contact with the inorganic coating layer. The polymeric substrate layer has a free shrink between 0.5% and 50% in at least one of the machine direction or the transverse direction at the shrink onset temperature of the barrier component according to ASTM D2732. The inorganic coating layer has a thickness between 0.005 pm (micron) and 0.1 pm. The polymeric buffer layer comprises a thickness between 0.5 pm and 12 pm. A ratio of the thickness of the polymeric buffer layer to the thickness of the inorganic coating layer is between 20 and Attorney Docket No. 21406-WO

[0018] 500. The polymeric buffer layer comprises a Young’s modulus at the shrink onset temperature between 0.1 and 100 MPa, as calculated from measurements collected according to ASTM E2546-15 with Annex X.4.

[0019]

[0011] In some embodiments of the foldable packaging film, the base component is fiber-based. In some embodiments, the base component is polymer-based.

[0020]

[0012] In some embodiments of the foldable packaging film, the base component is configured to form a fold having dead fold properties.

[0021]

[0013] In some embodiments, the foldable packaging film further includes a polymeric adhesive layer coupling the base component to the barrier component.

[0022]

[0014] Embodiments of the barrier component may have one or more of the following features:

[0023] • the polymeric buffer layer has a thickness between 1 pm and 5 pm;

[0024] • the inorganic coating layer is an oxide coating layer, such as a metal oxide coating layer or a metalloid oxide coating layer, and the thickness of the inorganic coating layer is between 0.005 pm and 0.06 pm;

[0025] • a ratio of the thickness of the polymeric buffer layer to the thickness of the inorganic coating layer is between 30 and 120;

[0026] • the polymeric substrate layer includes a monoaxially oriented polypropylene film, a biaxially oriented polypropylene film, a monoaxially oriented polyethylene film, a biaxially oriented polyethylene film, a biaxially oriented polyamide film, a biaxially oriented EVOH film, a monoaxially oriented polyester films, a biaxially oriented polyester film, a monoaxially oriented polylactic acid film, or a biaxially oriented polylactic acid film, and the polymeric substrate layer has a thickness between 4.5 pm and 100 pm;

[0027] • the polymeric substrate layer includes an oriented polyolefin film;

[0028] • the free shrink of the polymeric substrate layer is between 1 % and 6 % at the shrink onset temperature according to ASTM D2732;

[0029] • the polymeric buffer layer includes a vinyl alcohol copolymer, polypropylene, polyurethane, polybutylene succinate, polybutylene adipate terephthalate, polylactic acid, a cyclic olefin copolymer, or an ethylene vinyl acetate copolymer; Attorney Docket No. 21406-WO

[0030] • the barrier component includes a second polymeric buffer layer in direct contact with the inorganic coating layer; and

[0031] • the barrier component further includes one or more additional polyolefin layers.

[0032]

[0015] In some embodiments of the barrier component, the polymeric substrate layer includes biaxially oriented polypropylene having a thickness between 10 pm and 50 pm, the inorganic coating layer includes aluminum oxide (AIOx) or silicon oxide (SiOx), the thickness of the inorganic coating layer is between 0.01 pm and 0.1 pm, the polymeric buffer layer includes polyurethane, and the thickness of the polymeric buffer layer is between 1 pm and 2.5 pm.

[0033]

[0016] In some embodiments of the barrier component, the polymeric substrate layer includes a monoaxially oriented polyethylene film, the polymeric buffer layer includes a vinyl alcohol copolymer (e.g., ethylene vinyl alcohol copolymer (EVOH)), and the inorganic coating layer includes AIOx or SiOx.

[0034]

[0017] In another aspect of the present disclosure, a foldable packaging film includes a base component, a barrier component, and a polymeric adhesive layer coupling the base component to the barrier component. The barrier component includes a polymeric substrate layer, an inorganic coating layer, and a polymeric buffer layer positioned between the polymeric substrate layer and the inorganic coating layer. The polymeric buffer layer is in direct contact with the inorganic coating layer. The inorganic coating layer includes a wave structure characterized by an average amplitude between 0.05 pm and 1 .0 pm and a wavelength between 1 .0 pm and 5.0 pm. The polymeric buffer layer has a thickness between 1 pm and 5 pm that is between 1 .05 and 100 times the average amplitude of the wave structure.

[0035]

[0018] In some embodiments of the foldable packaging film, the base component is fiber-based. In some embodiments, the base component is polymer-based.

[0036]

[0019] In some embodiments of the foldable packaging film, the base component is configured to form a fold having dead fold properties.

[0037]

[0020] In some embodiments of the barrier component, the wave structure is characterized by a ratio of the wavelength to the average amplitude between 1 and 100. Attorney Docket No. 21406-WO

[0038]

[0021] In some embodiments of the barrier component, the inorganic coating layer includes an oxide coating layer, such as a metal oxide coating layer or a metalloid oxide coating layer, and a thickness of the inorganic coating layer is between 0.005 pm and 0.1 pm.

[0039]

[0022] In some embodiments of the barrier component, the polymeric substrate layer includes a monoaxially oriented polypropylene film, a biaxially oriented polypropylene film, a monoaxially oriented polyethylene film, a biaxially oriented polyethylene film, a biaxially oriented polyamide film, a biaxially oriented EVOH film, a monoaxially oriented polyester films, a biaxially oriented polyester film, a monoaxially oriented polylactic acid film, or a biaxially oriented polylactic acid film.

[0040]

[0023] In some embodiments of the barrier component, the polymeric substrate layer includes an oriented polyolefin film. In some embodiments of the barrier component, the polymeric buffer layer includes polypropylene, polyurethane, polylactic acid (PLA), polybutylene succinate (PBS), polybutylene adipate terephthalate (PBAT), a cyclic olefin copolymer (COG), a vinyl alcohol copolymer (e.g., ethylene vinyl alcohol (EVOH) copolymer), or an ethylene vinyl acetate copolymer.

[0041]

[0024] In some embodiments, the barrier component includes a second polymeric buffer layer in direct contact with the inorganic coating layer. In some embodiments, the barrier component further includes one or more additional polyolefin layers.

[0042]

[0025] In some embodiments of the barrier component, the polymeric substrate layer includes a biaxially oriented polypropylene film with a thickness between 10 pm and 50 pm, the inorganic coating layer includes a vacuum deposited AIOx or SiOx, the thickness of the inorganic coating layer is between 0.01 pm and 0.1 pm, and the average amplitude of the wave structure is between 0.4 pm and 1 .0 pm.

[0043]

[0026] In some embodiments of the barrier component, the polymeric substrate layer includes a monoaxially oriented polyethylene film, the polymeric buffer layer includes a vinyl alcohol copolymer (e.g., EVOH), the inorganic coating layer includes AIOx or SiOx, the average amplitude of the wave structure is between 0.15 pm and 1 .0 pm, and the wavelength of the wave structure is between 1 .0 pm and 4.0 pm. In some embodiments of the barrier component, the polymeric buffer layer includes polyurethane. Attorney Docket No. 21406-WO

[0044]

[0027] In some embodiments, the foldable packaging film includes a folding axis along which a fold is formed, and the wave structure is arranged parallel to the folding axis.

[0045]

[0028] In some embodiments, a method for producing the foldable packaging film having the wave structure in the barrier component includes the steps of:

[0046] • providing the base component,

[0047] • forming the barrier component, and

[0048] • extruding a melt curtain of the polymeric adhesive layer between the base component and the barrier component in an extrusion lamination process, thereby coupling the base component to the barrier component, wherein the step of extruding the melt curtain of the polymeric adhesive layer causes the wave structure to form in the inorganic coating layer.

[0049]

[0029] In some embodiments, the step of forming the barrier component includes the steps of:

[0050] • providing the polymeric substrate layer,

[0051] • applying the polymeric buffer layer to a surface of the polymeric substrate layer by techniques comprising extrusion, lacquering, spray coating, or solvent evaporation, and

[0052] • applying the inorganic coating layer to a surface of the polymeric buffer layer by vacuum deposition.

[0053]

[0030] In some embodiments, a method for producing a folded package includes the steps of:

[0054] • providing the foldable packaging film disclosed herein, where the foldable packaging film includes the wave structure in the barrier component,

[0055] • heating the foldable packaging film to a folding temperature that is above room temperature,

[0056] • folding the foldable packaging film along a folding axis, and

[0057] • sealing the foldable packaging film.

[0058]

[0031] In some embodiments, the folding temperature is greater than 85 °C. In some embodiments, the step of folding the foldable packaging film results in a fold having dead fold properties. Attorney Docket No. 21406-WO

[0059]

[0032] In some embodiments, a hermetically sealed package includes the foldable packaging film disclosed herein, where the foldable packaging film includes the wave structure in the barrier component.

[0060]

[0033] In some embodiments, a method of producing a shelf-stable packed product includes the steps of:

[0061] • providing the foldable packaging film disclosed herein, where the foldable packaging film includes the wave structure in the barrier component,

[0062] • heating the foldable packaging film to a folding temperature that is above room temperature,

[0063] • folding the foldable packaging film along a folding axis to form a package,

[0064] • filling the package with a product, and

[0065] • hermetically sealing the product inside the package to form a packaged product.

[0066] BRIEF DESCRIPTION OF THE DRAWINGS

[0067]

[0034] 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:

[0068]

[0035] Figure 1 is a cross-sectional view of an embodiment of a foldable packaging film including a barrier component coupled to a base component by a polymeric adhesive layer;

[0069]

[0036] Figure 2 is a cross-sectional view of an embodiment of a barrier component after performing a heat treatment and forming a wave structure in the barrier component;

[0070]

[0037] Figure 3 is a cross-sectional view of an embodiment of a barrier component prior to forming a wave structure in the barrier component;

[0071]

[0038] Figure 4 is a cross-sectional view of an embodiment of a barrier component prior to performing a heat treatment and forming a wave structure in the barrier component; Attorney Docket No. 21406-WO

[0072]

[0039] Figure 5 is an optical micrograph of a top view of a barrier component including a wave structure;

[0073]

[0040] Figure 6 is a flowchart showing steps of a method of producing a barrier component;

[0074]

[0041] Figure 7 is a flowchart showing steps of a method of producing a foldable packaging film that includes a barrier component having a wave structure;

[0075]

[0042] Figure 8 is a flowchart showing steps of a method of producing a package that includes a foldable packaging film with a barrier component having a wave structure;

[0076]

[0043] Figure 9 is a schematic showing folding forces exerted on an inorganic coating layer of a barrier component that includes a wave structure;

[0077]

[0044] Figure 10A is an optical micrograph of a top view of a barrier component that included a wave structure and was folded along a folding axis (FA) at a folding temperature greater than room temperature;

[0078]

[0045] Figure 10B is an optical micrograph of a top view of a barrier component that did not include a wave structure and was folded along a folding axis (FA);

[0079]

[0046] Figure 11 is an atomic force microscopy (AFM) image of a top view of a barrier component that did not include a wave structure and was folded along a folding axis (FA) at room temperature;

[0080]

[0047] Figure 12A is an optical micrograph of a top view of a barrier component that included a wave structure and was folded along a folding axis (FA) at a folding temperature greater than room temperature;

[0081]

[0048] Figure 12B is an optical micrograph of a top view of a barrier component that included a wave structure and was folded along a folding axis (FA) at room temperature;

[0082]

[0049] Figure 13A is an optical micrograph of a top view of a barrier component that included an MDOPE film and a wave structure, where the barrier component was shrunk in a cross-direction (CD) and folded along a folding axis (FA) that was parallel to the MD at a folding temperature greater than room temperature; and Attorney Docket No. 21406-WO

[0083]

[0050] Figure 13B is an optical micrograph of a top view of a barrier component that included an MDOPE film and a wave structure, where the barrier component was shrunk in a cross-direction (CD) and folded along a folding axis (FA) that was perpendicular to the MD at a folding temperature greater than room temperature.

[0084]

[0051] 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.

[0085] DETAILED DESCRIPTION

[0086]

[0052] A foldable packaging film includes a base component coupled to a barrier component via a polymeric adhesive layer. The barrier component according to the present disclosure includes at least one heat-shrinkable polymeric substrate layer, at least one inorganic coating layer, and at least one polymeric buffer layer, the polymeric buffer layer in direct contact with the inorganic coating layer and positioned between the polymeric substrate layer and the inorganic coating layer. During exposure to temperatures high enough to cause the polymeric substrate layer to shrink, the role of the buffer layer is to be a malleable interface between the shrinking substrate layer and the stiff and non-shrinking inorganic coating layer, allowing a continuous wave structure to form within the inorganic layer at the surface of the buffer layer. By formation of this wave structure, cracks within the inorganic coating layer can be substantially reduced and the loss of oxygen and water vapor barrier due to the shrinking substrate layer can be mitigated.

[0087]

[0053] The wave structure formation effect of the inorganic layer on the buffer layer is obtained by a subtle equilibrium between 1 ) polymeric buffer layer thickness, 2) elastic modulus of the polymeric buffer material at the heat treatment temperature, and 3) the thickness of the inorganic layer. At and above the temperature at which the substrate layer begins to shrink (i.e., shrink onset temperature), the buffer layer must have a modulus such that it can change shape. The shape change is a result of a shrinking surface area on the side of the buffer layer nearest the shrinking substrate layer and the non-shrinking surface area on the side of the buffer layer adjacent the inorganic coating Attorney Docket No. 21406-WO layer. Due to its low modulus, the surface of the buffer layer adjacent to the substrate layer can move and adjust to the shrinking force. The buffer layer adjacent to the inorganic layer conforms to a wave structure to accommodate for the unchanging surface area of the inorganic coating layer. The wave structure of the inorganic coating may form in one or more patterns including but not limited to regular (i.e., stripes), herringbone and random (i.e., labyrinths). The formation of the waves allows the inorganic coating layer to flex, retaining its original area and remain intact, without cracks (or without as many cracks), reducing or eliminating the degradation of the barrier of this layer that can occur due to shrinking of the substrate layer.

[0088]

[0054] Without limiting the current invention, a model used to describe the theoretical formation of waves in various systems can be found in Huang, ZY, Hong, W, Suo Z 2005, ‘Nonlinear Analysis of Wrinkles in a Film Bonded to a Compliant Substrate’, Journal of the Mechanics and Physics of Solids, 53, 2101 -21 18.

[0089]

[0055] “Shrink onset temperature” as used herein is the temperature at which the barrier component demonstrates a free shrink of at least 1 % in at least one of the MD or the TD. “Free Shrink” as used herein is an unrestrained linear shrinkage that a film or layer undergoes due to exposure to elevated temperature. The shrink is irreversible and relatively rapid (i.e., evident within seconds or minutes). Free shrink is expressed as a percentage of the original dimension, (i.e., 100 x (pre-shrink dimension - post-shrink dimension) / (pre-shrink dimension)). Free shrink can be measured using ASTM D2732. Alternatively, free shrink can be measured by using the test method described in ASTM D2732 with a modification of using hot air as the heating source instead of a hot fluid bath. If using the hot air method, place the unrestrained sample in the oven set at the specified temperature for a time span of at least 1 minute, giving the oven interior and sample ample time to come to thermal equilibrium. To determine the shrink onset temperature, perform the free shrink test at 10°C increasing increments until the material shrinks at least 1 % in one or both of the machine direction and the transverse direction. The temperature at which the free shrink is at least 1 % in at least one direction (machine-direction (MD) or cross-direction (CD)) is the shrink onset temperature. Practical shrink onset temperatures for the barrier components described herein may be between 50°C and 200°C. Attorney Docket No. 21406-WO

[0090]

[0056] “Polymeric buffer layer” as used herein is a layer within the barrier component, directly adjacent to and in contact with the inorganic coating layer, having the function of allowing the inorganic coating layer to flex from a relatively flat cross-sectional geometry into a wave structure. The polymeric buffer layer is formulated such that the material or blend of materials becomes malleable in the temperature range at which the barrier component experiences slight shrinking due to thermal exposure (e.g., at the shrink onset temperature of the barrier component), as is further described herein. The formula of the polymeric buffer layer can be directed toward achieving an elastic modulus in the appropriate temperature range that allows the material to be pliable.

[0091]

[0057] 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.

[0092]

[0058] “Inorganic Coating Layer” as used herein refers to a layer that comprises a metal layer or an oxide (e.g., a metal oxide, a metalloid oxide) coating layer. These layers function for barrier purposes. The inorganic coating layer may be vacuum deposited (e.g., vacuum coated, vapor coated, vacuum metalized) directly on the surface of the buffer layer. The inorganic coating layer may also be deposited by alternative methods, such as chemical vapor deposition (CVD), atomic layer deposition (ALD), or physical vapor deposition (PVD). Alternatively, the inorganic coating layer may be deposited by wet chemistry methods, such as solution coating.

[0093]

[0059] As described herein, the polymeric substrate layer may be oriented. Orientation may be the result of monoaxially oriented (machine direction or transverse direction), or biaxially oriented (machine direction and transverse direction) stretching of the film, increasing the machine direction and / or transverse direction dimension and subsequently decreasing the thickness of the material. Biaxial orientation may be imparted to the film simultaneously or successively. Stretching in either or both directions is subjected to the film at a temperature just below the melt temperature of the polymers in the film. In this manner, the stretching causes the polymer chains to “orient”, changing the physical properties of the film. At the same time, the stretching thins the film. The resulting oriented films are thinner and can have significant changes in mechanical properties such as toughness, heat resistance, stiffness, tear strength Attorney Docket No. 21406-WO and barrier. Orientation is typically accomplished by a double- or triple-bubble process, by a tenter-frame process or a machine-direction oriented (MDO) process using heated rolls. A typical blown film process does impart some stretching of the film, but not enough to be considered oriented as described herein. An oriented film may be heat-set (i.e., annealed) after orientation, such that it is relatively dimensionally stable under elevated temperature conditions that might be experienced during conversion of the film laminate (i.e., printing or laminating) or during the use of the laminate (i.e., heat sealing or retort sterilization).

[0094]

[0060] As used herein, the term “polyolefin” generally includes polypropylene and polyethylene polymers.

[0095]

[0061] As used throughout this application, the term “copolymer” refers to a polymer product obtained by the polymerization reaction or copolymerization of at least two monomer species. The term “copolymer” is also inclusive of the polymerization reaction of three, four or more monomer species having reaction products referred to terpolymers, quaterpolymers, etc.

[0096]

[0062] As used throughout this application, the term "polypropylene" or “PP” refers to, unless indicated otherwise, propylene homopolymers or copolymers. Such copolymers of propylene include copolymers of propylene with at least one alpha-olefin and copolymers of propylene with other units or groups. The term “polypropylene” or “PP” is used without regard to the presence or absence of substituent branch groups or other modifiers. Polypropylene includes, for example, homopolymer polypropylene, polypropylene impact copolymer, polypropylene random copolymer, etc. Various polypropylene polymers may be recycled as reclaimed polypropylene or reclaimed polyolefin.

[0097]

[0063] As used throughout this application, the term "polyethylene" or “PE” refers to, unless indicated otherwise, ethylene homopolymers or copolymers. Such copolymers of ethylene include copolymers of ethylene with at least one alpha-olefin and copolymers of ethylene with other units or groups such as vinyl acetate, acid groups, acrylate groups, or otherwise. The term “polyethylene” or “PE” is used without regard to the presence or absence of substituent branch groups. Polyethylene includes, for example, Attorney Docket No. 21406-WO medium density polyethylene, high density polyethylene, low density polyethylene, linear low-density polyethylene, ultra-low density polyethylene, ethylene alpha-olefin copolymer, ethylene vinyl acetate, ethylene acid copolymers, ethylene acrylate copolymers, or blends of such. Various polyethylene polymers may be recycled as reclaimed polyethylene or reclaimed polyolefin.

[0098]

[0064] As used throughout this application, the term “polyester” or “PET” refers to a homopolymer or copolymer having an ester linkage between monomer units. The ester linkage may be represented by the general formula [O-R-OC(O)-R'-C(O)]nwhere R and R' are the same or different alkyl (or aryl) group and may generally be formed from the polymerization of dicarboxylic acid and diol monomers.

[0099]

[0065] As used herein, the term "polyamide" refers to a high molecular weight polymer having amide linkages (-CONH-)n which occur along the molecular chain and includes "nylon" resins which are well known polymers having a multitude of uses including utility as packaging films. Examples of nylon polymeric resins for use in food packaging and processing include: nylon 66, nylon 610, nylon 66 / 610, nylon 6 / 66, nylon 1 1 , nylon 6, nylon 66T, nylon 612, nylon 12, nylon 6 / 12, nylon 6 / 69, nylon 46, nylon 6-3-T, nylon MXD-6, nylon MXDI, nylon 12T and nylon 6I / 6T. Examples of polyamides include nylon homopolymers and copolymers such as nylon 4,6 (poly(tetramethylene adipamide)), nylon 6 (polycaprolactam), nylon 6,6 (poly(hexamethylene adipamide)), nylon 6,9 (poly(hexamethylene nonanediamide)), nylon 6,10 (poly(hexamethylene sebacamide)), nylon 6,12 (poly(hexamethylene dodecanediamide)), nylon 6 / 12 (poly(caprolactam-co- dodecanediamide)), nylon 6,6 / 6 (poly(hexamethylene adipamide-co-caprolactam)), nylon 66 / 610 (e.g., manufactured by the condensation of mixtures of nylon 66 salts and nylon 610 salts), nylon 6 / 69 resins (e.g., manufactured by the condensation of epsilon- caprolactam, hexamethylenediamine and azelaic acid), nylon 11 (polyundecanolactam), nylon 12 (polylauryllactam) and copolymers or mixtures thereof. Polyamide is used in films for food packaging and other applications because of its unique physical and chemical properties. Polyamide is selected as a material to improve temperature resistance, abrasion resistance, puncture strength and / or barrier of films. Properties of polyamide-containing films can be modified by selection of a wide variety of variables Attorney Docket No. 21406-WO including copolymer selection, and converting methods (e.g., coextrusion, orientation, lamination, and coating).

[0100]

[0066] As used herein, “polyurethane” is generally referencing polymers having organic units joined by urethane links (-NH-(C=O)-O-).

[0101]

[0067] As used herein, “polylactic acid” (PLA) is a polymer made from lactic acid and having a backbone of [-C(CH3)HC(=O)O-]n.

[0102]

[0068] As used throughout this application, the term “vinyl alcohol copolymer” refers to film forming copolymers of vinyl alcohol (CH2CHOH). Examples include, but are not limited to, ethylene vinyl alcohol copolymer (EVOH), butenediol vinyl alcohol copolymer (BVOH), and polyvinyl alcohol (PVOH).

[0103]

[0069] As used throughout this application, the term “ethylene vinyl alcohol copolymer”, “EVOH copolymer” or “EVOH” refers to copolymers comprised of repeating units of ethylene and vinyl alcohol. Ethylene vinyl alcohol copolymers may be represented by the general formula: [(CH2-CH2)n-(CH2 -CH(OH))]n. Ethylene vinyl alcohol copolymers may include saponified or hydrolyzed ethylene vinyl acetate copolymers. EVOH refers to a vinyl alcohol copolymer having an ethylene co-monomer and prepared by, for example, hydrolysis of vinyl acetate copolymers or by chemical reactions with vinyl alcohol. Ethylene vinyl alcohol copolymers may comprise from 28 mole percent (or less) to 48 mole percent (or greater) ethylene.

[0104]

[0070] As used herein, the phrase "ethylene / norbornene copolymer" refers to a class of polymeric materials based on cyclic olefin monomers and ethane. Ethylene / norbornene copolymers are known commercially as cyclic olefin copolymers, "COC," with one or more different cyclic olefin units randomly or alternately attached to the ethylene polymer backbone. In general, COCs exhibit a high glass transition temperature (greater than 50. °C.), optical clarity, low heat shrinkage, low moisture absorption and low birefringence. These materials may be produced by a number of polymerization techniques which may include chain polymerization of cyclic monomers such as 8,9,10- trinorborn-2-ene (norbornene) of 1 ,2,3,4,4a,5,8,8a-octa-hydro-1 ,4:5,8- dimethanonaphthalene (tetracyclododecene) with ethane; or ring-opening metathesis of various cyclic monomers followed by hydrogenation. Attorney Docket No. 21406-WO

[0105]

[0071] The term "layer", as used herein, refers to a building block of a film that is a structure of a single material type or a homogeneous 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 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 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.

[0106]

[0072] 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. A film has two major surfaces, the area of which are defined by the length and width of the film.

[0107]

[0073] As used herein, the term “exterior” is used to describe a film or layer that is located on one of the major surfaces of the film in which it is comprised. As used herein, the term “interior” 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.

[0108]

[0074] As used herein, a “sealing layer” is a layer comprising a composition configured to affix the film to another structure or itself, such as a surface of a package or packaging film, via fusion bonding or chemical bonding, such as adhesion. For example, the sealing layer may comprise a heat sealable polymeric composition. In some embodiments, the sealing layer forms one of the two major surfaces of the film. In some embodiments, there may be a first sealing layer on one major surface of the film and a second sealing layer on the other major surface of the film. Attorney Docket No. 21406-WO

[0109]

[0075] “Wave structure” as used herein refers to a cross-sectional geometry of the inorganic coating layer and the surface of the adjacent polymeric buffer layer(s). As with any wave, the wave structure has a wavelength, measurable in the x-y direction, and an amplitude, measurable in the z-direction.

[0110]

[0076] The wavelength of the wave structure can be determined using top view microscopy techniques including, but not limited to, optical microscopy, laser scanning microscopy, electron microscopy, or atomic force microscopy. The resolution of the microscope needs to be sufficient to identify features on the waves, such as wave peaks and wave valleys. An example of a representative top view microscopy is shown in Figure 5. As shown in this view, the waves can include various patterns and are organized into wave domains, or sections where the waves are regular and ordered. The wave domains meet at corners or edges and form irregular folds or intersections. Measurements of the waves can be executed in the wave domains, examples of which are indicated by superimposed ovals. Variations in wave measurements can occur at the intersections, examples of which are indicated by superimposed circles, as the colliding waves interfere with the regular pattern. The intersections of waves are not used for wave measurements.

[0111]

[0077] The wavelength is the distance between either peak to peak or valley to valley in an undistorted area of waves (i.e., wave domain). An average wavelength is calculated by taking the average of at least 5 individual wavelength measurements.

[0112]

[0078] Other techniques to determine the wavelength are possible. For example, the wavelength may be measured using a cross-sectional view of the wave structure. Another option would be to measure it in an optical setup, using the waves as a grating. The resulting spectrum of a light shining through the film may be used to determine the wavelength.

[0113]

[0079] The amplitude of a wave structure (i.e., the distance from valley to peak of a wave) can be assessed on a film using a z-direction information sensitive microscope. For example, the microscope may be a laser scanning microscope or an atomic force microscope. The resolution in the z-direction should be at least as small as the tens of nanometers range. Attorney Docket No. 21406-WO

[0114]

[0080] In some embodiments of the film, the amplitude can be determined on a cut cross-section (i.e., microtome cut, embedded in epoxy and polished, or other routes) in a microscope with appropriate resolution and contrast. As the shrink in a laminate containing many layers is generally less than shrink in a film containing only a polymeric substrate layer, a polymeric buffer layer and an inorganic coating layer, the amplitude may be lower.

[0115]

[0081] As used herein, the “average amplitude” is determined by measurement of the amplitude of at least five individual waves using one or more positions across the film sample in undistorted areas (i.e., wave domains) and calculating the average of these five measurements.

[0116]

[0082] As used herein, “barrier” or “barrier film” or “barrier layer” or “barrier material” refers to providing for reduced transmission to gases such as oxygen (i.e., containing an oxygen barrier material). The barrier material may provide reduced transmission to moisture (i.e., containing a moisture barrier material). The barrier characteristic may be provided by one or more, or a blend, of multiple barrier materials. The barrier layer may provide the specific barrier required to preserve the product within a package throughout an extended shelf-life which may be several months or even more than one year.

[0117]

[0083] The barrier may reduce the influx of oxygen through the barrier component during the shelf-life of a packaged product (i.e., while the package is hermetically sealed). The oxygen transmission rate (OTR) of the barrier component is an indication of the barrier provided and can be measured according to ASTM F1927 using conditions of 1 atmosphere, 23°C and 50% RH.

[0118]

[0084] As used herein, “modulus,” “Young’s modulus,” or “elastic modulus” is a measure of a materials ability to change dimension when under tensile or compressive force, in units of force per unit area. A material with a higher Young’s modulus may be relatively stiff while a material with a lower Young’s modulus is relative soft and pliable (i.e., elastic). Young’s modulus can be calculated from a force-displacement data set derived from a nanoindentation test procedure. Attorney Docket No. 21406-WO

[0119]

[0085] As used herein, “ASTM E2546-15 Annex X.4” refers to an instrumented indentation test procedure according to the documented standard using apparatus including a silicon tip mounted on a silicon cantilever with a defined tip radius of 30 nm.

[0120]

[0086] As used herein, “fiber” or “fiber-based” may include, but not be limited to, cellulose and / or cellulose-based fibers including virgin cellulose-based fibers, recycled fibers including materials like paper fibers and craft papers, textiles, non-woven fibers, wood-based fibers, cotton, linen, hemp, sugar cane or sorghum commonly known as bagasse fibers, or grains. These fibers may be untreated and / or treated to provide enhancements or improvements to their inherent properties. These fibers may be provided in a plurality of dimensions / lengths including micro and nano fibrillated types, such as, but not limited to, microfibrillated and / or nanofibrillated cellulose. Further, these fibers for a fiber-based article may contain fluff pulp and / or another fiber type and may be provided in a roll, bale, blank or sheet form, continuous web, and / or may be formed from an airlaid process, and / or may be provided in a slurry for forming in a wet molding process. Further, the use of fiber or fiber-based materials may provide a multitude of end of use options for the tray, wherein the tray may be recycled, compostable, biodegradable, repulpable, or be considered responsibly disposable.

[0121]

[0087] As used herein, the term “paper” or “paper component" may include any type of paper that can be processed in a paper recycling (repulpability) process. Further, the term “paper” or "paper component" may be described with respect to an amount of cellulose fibers in the paper component. For example, the paper component comprises or may consists essentially of cellulose fibers. As used in this context, "consisting essentially of" means that the total composition of the paper component includes greater than or equal to 95 %, greater than or equal to 98 %, greater than or equal to 99 %, greater than or equal to 99.9% or 100% cellulose fibers. In some cases, the paper component may contain up to 20 % mineral filler by weight and correspondingly an amount greater than or equal to 80 % cellulose fibers.

[0122]

[0088] As used herein, the term "polymer" or “polymer-based” refers to the product of a polymerization reaction, and is inclusive of homopolymers, copolymers, terpolymers; Attorney Docket No. 21406-WO etc. In general, the layers of a film can consist essentially of a single polymer, or can have still additional polymers together therewith, i.e., blended therewith.

[0123]

[0089] As used herein, the term "adhesive layer” refers to a layer or material placed on one or more layers to promote the adhesion of that layer to another surface. Generally, adhesive layers are positioned between two layers of a multilayer film to maintain the two layers in position relative to each other and prevent undesirable delamination. Unless otherwise indicated, an adhesive layer can have any suitable composition that provides a desired level of adhesion with the one or more surfaces in contact with the adhesive layer material.

[0124]

[0090] As used herein, the term "polymeric adhesive layer" refers to a layer of polymeric material serving a primary purpose or function of adhering two surfaces to one another. In some embodiments, the polymeric adhesive layer may adhere one film layer surface to another film layer surface or one area of a film layer surface to another area of the same film layer surface. The polymeric adhesive layer may comprise any polymer, copolymer, or blend of polymers having a polar group thereon, or any other polymer, homopolymer, copolymer, or blend of polymers including modified and unmodified polymers, e.g., grafted copolymers, that provide sufficient interlayer adhesion to adjacent layers comprising otherwise non-adhering polymers. The polymeric adhesive layers conform to the compositional requirements of the U.S. Food and Drug Administration Code of Federal Regulations, Title 21 , 175.105, Adhesives, the entirety of which is incorporated herein by reference.

[0125]

[0091] As used herein, the term “fold” or “folded” means to bend over on to itself and the bend of the fold may have a sharp or rounded edge. This bent over shape may be described as “V-shaped,” wherein the fold has an apex at a convergence of the bent over surfaces. Accordingly, the V-shape can alternately be described as generally having a narrow portion and a wide portion with the apex being the narrow-most point of the narrow portion. A directionality of the fold may be defined as “inside” or “outside.” The term “inside” refers to a fold that results a relatively stiffer layer (i.e., a layer with a higher modulus) of the barrier component (e.g., an inorganic coating layer) to form on an inside of the fold. The term “outside” refers to a fold that results the relatively stiffer Attorney Docket No. 21406-WO layer to form on an outside of the fold. The term “dead fold” refers to a fold that is not capable of unfolding spontaneously, such as a fold in a soft metal foil material or paper.

[0126]

[0092] As used herein, a “hermetically sealed package” is a package made from the barrier component described herein that maintains a high barrier level with little degradation after exposure to at or above the shrink onset temperature. The packages are such that can be filled with product, sealed, and remain hermetically sealed, maintaining excellent barrier properties.

[0127]

[0093] The barrier components described herein may be useful in packaging films, such as hermetic packaging films. As used herein, a “hermetic packaging film” or “hermetically sealed package” is a film, or package made from the film, that can be filled with product, sealed, and remain hermetically sealed. The “hermetic packaging film” or “hermetically sealed package” maintains a high barrier level with little degradation after exposure to at or above the shrink onset temperature. A packaging film including the barrier components described herein may be folded (e.g., may include one or more folds) during a folding process to form a package. In some embodiments, the barrier component provides sufficient mechanical durability to withstand potential physical abuse endured during such a folding process, thereby maintaining a packaging film with a substantially reduced amount of cracks.

[0128]

[0094] Now referring to Figure 1 , a foldable packaging film 30 includes a barrier component 10, a base component 26, and a polymeric adhesive layer 25 positioned between the barrier component 10 and the base component 26. The polymeric adhesive layer 25 physically couples the barrier component 10 to the base component 26. The polymeric adhesive layer 25 may be in direct contact with each of the barrier component 10 and the base component 26, as shown in Figure 1 . Alternatively, there may be one or more additional layers positioned between the polymeric adhesive layer 25 and each of the barrier component 10 and the base component 26.

[0129]

[0095] The base component 26 includes a fiber-based material. In some embodiments, the base component 26 consists essentially of cellulose fibers. In some embodiments, the base component 26 is a paper component that consists essentially of cellulose fibers. In some embodiments, an exterior surface of the base component 26 is further Attorney Docket No. 21406-WO coated with a thermal plastic resin layer (not shown) by a process such as extrusion coating. In some embodiments, a printing layer is provided to the exterior surface of the base component 26 prior to coating the exterior surface with the thermal plastic resin layer. Alternatively, the printing layer may be provided to an exterior surface of the thermal plastic resin layer after performing the extrusion coating process. In some embodiments, a score line along which the foldable packaging film 30 is subsequently folded is formed on the base component 26 by a process such as press ruling.

[0130]

[0096] The thermal plastic resin layer may include any polyolefin having sealing properties. In other words, the thermal plastic resin layer is coated onto the exterior surface of the base component 26 as a sealing layer. Examples of the thermal plastic resin layer include, but are not limited to, ethylene resins such as low density polyethylene resin (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), ethylene-a-olefin copolymer, and polypropylene (PP) resins such as homopolypropylene resin, propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-a-olefin copolymer.

[0131]

[0097] The polymeric adhesive layer 25 is positioned between the base component 26 and the barrier component 10. In some embodiments, as shown in Figure 1 , the polymeric adhesive layer 25 directly contacts a surface of the base component 26 and a surface of the barrier component 10. The polymeric adhesive layer 25 is configured to adhere or attach the barrier component 10 to the base component 26, thereby coupling the components together to form the foldable packaging film 30. In some embodiments, the polymeric adhesive layer 25 includes a coextruded polymeric layer. In some embodiments, the polymeric adhesive layer 25 couples the barrier component 10 to the base component 26 by a process of extrusion lamination. In this regard, the polymeric adhesive layer 25 is extruded as a melt curtain that couples the barrier component 10 to the base component 26. In some embodiments, the polymeric adhesive layer 25 includes multiple layers, coextruded in the same melt curtain.

[0132]

[0098] The polymeric adhesive layer 25 may include a thermal melting resin. Examples of the thermal melting resin include, but are not limited to, acid-modified polyolefin Attorney Docket No. 21406-WO resins, which include polyolefin resins such as LDPE, MDPE, HDPE, LLDPE, PP, ethylene-vinyl acetate copolymer (EVA), ionomer resin, ethylene-methyl acrylate copolymer (EMA), ethylene- acrylate acid copolymer (EAA), ethylene-methacrylate acid copolymer (EMAA), ethylene-propylene copolymer, , polyethylene and polypropylene, which may be modified by unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride fumaric acid, and itaconic acid.

[0133]

[0099] The barrier component 10 includes a polymeric substrate layer 12, an inorganic coating layer 13, and a polymeric buffer layer 14 positioned between the polymeric substrate layer 12 and the inorganic coating layer 13. The polymeric buffer layer 14 is in direct contact with the inorganic coating layer 13. The polymeric buffer layer 14 may be in direct contact with the polymeric substrate layer 12, as shown in Figure 1 , or there may be one or more additional layers between them.

[0134]

[0100] The polymeric substrate layer 12 has a free shrink value greater than zero in at least one of the machine direction (MD) or the transverse direction (TD or crossdirection, CD) at the shrink onset temperature of the barrier component in which it is comprised. The free shrink of the polymeric substrate layer 12 experienced at the shrink onset temperature, or another temperature above the shrink onset temperature to which the barrier component 10 is exposed, causes a decrease in the surface area of the polymeric substrate layer 12. Any attached layer adjacent to or near the shrinking polymeric substrate layer 12 experiences a shrink force in the x-y direction, due to the reduction of surface area.

[0135]

[0101] The free shrink of the polymeric substrate layer 12 at the shrink onset temperature may be between 0.5 % and 50 %, between 0.5 % and 25 %, between 1 % and 10 % or between 1 % and 6 %. The free shrink of the polymeric substrate layer 12 may be measured on the polymeric substrate layer 12 alone (including any sublayers that may be present). Alternatively, the free shrink of the polymeric substrate layer 12 may be measured on a combination of the polymeric substrate layer 12 and the polymeric buffer layer 14, plus any intervening layers, together. The free shrink of the polymeric substrate layer 12 may be measured when it is connected to the inorganic Attorney Docket No. 21406-WO coating layer 13, including the polymeric buffer layer 12 and any other intervening layers.

[0136]

[0102] The polymeric substrate layer 12 may include any polymer including, but not limited to, EVOH, polyester, polyethylene, polypropylene, polyamide, and polylactic acid, or blends of polymers. The polymeric substrate layer 12 may include any number of sublayers. The sublayers of the polymeric substrate layer 12 may include polymers within the same polymer class (i.e., all layers are various types of polypropylene polymers) or the sublayers may be of different polymer classes. The polymeric substrate layer 12 may be oriented or non-oriented. The polymeric substrate layer may be relatively clear, translucent, or opaque. The polymeric substrate layer 12 may have printed indicia deposited on either of the major surfaces.

[0137]

[0103] The polymeric substrate layer 12 may be a film and the film may be produced by any known process, for example blown film or cast film. The polymeric substrate layer 12 may include a monoaxially oriented polypropylene film (MDOPP), a biaxially oriented polypropylene film (BOPP), a monoaxially oriented polyethylene film (MDOPE), a biaxially oriented polyethylene film (BOPE), a biaxially oriented polyamide film (BOPA), a biaxially oriented EVOH film, a monoaxially oriented polyester film (MDOPET), a biaxially oriented polyester film (BOPET), a monoaxially oriented polylactic acid film (MDOPLA), or a biaxially oriented polylactic acid film (BOPLA). The polymeric substrate layer 12 may be produced using specific polymers and may be oriented using specific conditions which optimize the heat resistance of the film.

[0138]

[0104] The polymeric substrate layer 12 may have a thickness (prior to shrinking) between 4.5 pm and 100 pm. In some embodiments, the polymeric substrate layer 12 may have a thickness between 10 pm and 50 pm, or between 10 pm and 30 pm.

[0139]

[0105] The inorganic coating layer 13 of the barrier component 10 includes an inorganic metal oxide or an inorganic metalloid oxide that may be applied using a vacuumdeposition process, CVD, ALD, or PVD. Alternatively, the inorganic coating layer 13 may be applied using a wet chemistry technique. The inorganic coating layer 13 is deposited on the surface of the polymeric buffer layer 14. The inorganic coating layer 13 is directly adjacent to and in direct contact with the polymeric buffer layer 14. Attorney Docket No. 21406-WO

[0140]

[0106] The inorganic coating layer 13 provides a significant contribution to the oxygen barrier (i.e., reduction in OTR) to the barrier component 10. The inorganic coating layer 13 may include a transparent metal oxide coating layer such as aluminum oxide (i.e., AIOx) or a transparent metalloid oxide coating layer such as silicon oxide (i.e., SiOx). In some embodiments, the inorganic coating layer 13 is free, or substantially free, of any metal layer such as aluminum or a blend of aluminum and another metal.

[0141]

[0107] Referring to Figure 2, the inorganic coating layer 13 has a thickness 19 measured in the z-direction. The inorganic coating layer 13 has a thickness 19 between 0.005 pm and 0.1 pm, between 0.005 pm and 0.06 pm, between 0.01 pm and 0.1 pm or between 0.01 pm and 0.06 pm. An inorganic coating layer 13 having thickness greater than these ranges results in a layer that is not able to flex into the wave structure 80 to accommodate the surface area change without cracking or otherwise failing.

[0142]

[0108] In some embodiments, the polymeric buffer layer 14 has a thickness 18 measured in the z-direction. The polymeric buffer layer 14 has a thickness 18 between 0.5 pm and 12.0 pm, between 1 .0 pm and 5.0 pm, or between 1 .0 pm and 2.5 pm.

[0143]

[0109] A ratio of the thickness of the polymeric buffer layer 14 of the barrier component 10 to the thickness of the inorganic coating layer 13 of the barrier component 10 is between 20 and 500, or between 30 and 120. A ratio of thicknesses within this range is one of the combination of factors that allows for the formation of the wave structure 80 in the inorganic coating layer 13 upon the shrinking of the polymeric substrate layer 12 at temperatures above the shrink onset temperature of the barrier component 10.

[0144]

[0110] The polymeric buffer layer 14 of the barrier component 10 is located between the polymeric substrate layer 12 and the inorganic coating layer 13. The polymeric buffer layer 14 is in direct contact with the inorganic coating layer 13. The polymeric buffer layer 14 may be in direct contact with the polymeric substrate layer 12. The polymeric buffer layer 14 may be a layer within a film that also contains the polymeric substrate layer 12. In some embodiments of the barrier component 10 there may be intervening layers between the polymeric buffer layer 14 and the polymeric substrate layer 12.

[0145]

[0111] Without limiting, the polymeric buffer layer 14 may include polymers such as a vinyl alcohol copolymer, polyurethane (e.g., a polyurethane-based polymer), Attorney Docket No. 21406-WO polypropylene (e.g., a polypropylene-based polymer), polylactic acid (e.g., a polylactic acid-based polymer), polybutylene succinate (e.g., a PBS-based polymer), polybutylene adipate terephthalate (e.g., a PBAT-based polymer), a cyclic olefin copolymer, an ethylene vinyl acetate copolymer, blends of these polymers or blends of these materials with other materials. Again, without limiting, the polymeric buffer layer 14 may be produced by coating, extrusion, coextrusion, or lamination. Each of these techniques may be performed in-line with a coating process. The polymeric buffer layer 14 may have an intrinsic barrier property (oxygen or moisture barrier), that may contribute to the overall barrier property of the barrier component 10.

[0146]

[0112] The barrier component 10 may have an overall thickness from about 4.5 pm to about 254 pm, or from about 76.2 pm to about 152.4 pm.

[0147]

[0113] The barrier component 10 described herein may contain at least 80 % or at least 90 % polyolefin-based polymers by weight, promoting recyclability of the film and or package in which it is used. Materials that are not polyolefin-based polymers are minimized. For example, the barrier layer of the barrier component 10 is a material that is not a polyolefin-based material and thus is provided in as thin of a layer as possible to function properly as a barrier. The film may also have other non-polyolefin materials such as adhesives and inks.

[0148]

[0114] In some embodiments, the polymeric buffer layer 14 has a Young’s modulus of between 0.1 MPa and 100 MPa at an elevated temperature, such as at a temperature above the shrink onset temperature of the barrier component 10. This property of the polymeric buffer layer 14, in conjunction with the location and thickness of the polymeric buffer layer 14 among other details of the barrier component 10, advantageously allows for the formation of a wave structure 80 in the inorganic coating layer 13 as the polymeric substrate layer 12 shrinks, thereby preventing cracking and loss of barrier properties.

[0149]

[0115] Using the combination of film structure design elements as described herein, the barrier component 10 can be achieved. The layers of the barrier component 10 may be suitable to be recycled in a polyolefin-based recycling process because of the high polyolefin content. The layers may have low levels of, or may be essentially free from, Attorney Docket No. 21406-WO materials such as polyester, polyamide, chlorine-containing polymers and metal layers (e.g., aluminum foil). The layers may contain non-polyolefin-based polymers such as those used in adhesive layers or ink layers, but these are minimized and generally less than 10% of the overall composition, by weight. The layers may contain non-polymeric materials such as barrier materials, but these are minimized and generally less than 10% of the overall composition, by weight.

[0150]

[0116] As previously described herein, an increase in environmental temperature may cause the polymeric substrate layer 12 to shrink. As the temperature rises, the polymeric material softens, releasing tension that may have been embedded in the layer upon production, such as during orientation. The tension release may result in a movement and rearrangement of the polymer chains and an ultimate change (increase or decrease) in the dimensions of the layer. A common result of increasing temperature on a polymeric substrate layer 12 is a slight reduction in a dimension (i.e., shrink) of the polymeric substrate layer 12 in at least one direction parallel with the x-y plane of the polymeric substrate layer 12.

[0151]

[0117] Upon shrinking of the polymeric substrate layer 12, a compressive force is applied to the other layers within the barrier component 10 with the largest force being applied to the adjacent layers. The other layers may also have a shrinking tendency at the elevated temperature, and it is likely that the free shrink of each layer is slightly different. The greatest difference in free shrink is likely found when comparing a layer to the inorganic coating layer 13 of the barrier component 10. Most inorganic coatings experience no shrink at the temperatures at which the polymeric substrate layer 12 shrinks (i.e., at the shrink onset temperature, such as at 60°C or some other temperatures). Additionally, inorganic coatings (e.g., the inorganic coating layer 13) generally also have relatively higher modulus (i.e., high stiffness) at these elevated temperatures.

[0152]

[0118] Using the defined structure of the barrier component 10 explained herein, upon experiencing an elevated temperature, the polymeric substrate layer 12, and possibly other layers of the barrier component 10, will begin to shrink. The closely located polymeric buffer layer 14, having a low modulus at the elevated temperature, Attorney Docket No. 21406-WO experiences compressive forces in the x-y plane and conforms to the stresses easily. The surface of the polymeric buffer layer 14 may become slightly denser (i.e., possessing a higher density) or the polymeric buffer layer 14 may become slightly thicker (in the z-direction) as the surface area (in the x-y plane) of the polymeric substrate layer 12 decreases and the polymeric buffer layer 14 is compressed. The inorganic coating layer 13, however, is not pliable due to its relatively higher modulus (i.e., higher stiffness). As a result of the compressive forces in the x-y plane from the shrinking polymeric substrate layer 12 and the low modulus of the underlying (i.e., directly adjacent) polymeric buffer layer 14, the inorganic coating layer 13 may have a tendency to bend into a pattern of waves, with the amplitude of the waves forming in the z-direction. The formation of the wave structure 80 preserves the surface area of the inorganic coating layer 13, reducing or, in some embodiments, preventing formation of cracks that would typically form under the shrink (i.e., compressive) forces upon shrinking.

[0153]

[0119] Figure 1 shows a cross-sectional view of an embodiment of the foldable packaging film 30 in which the barrier component 10 includes a wave structure 80. In particular, the wave structure 80 is formed in the inorganic coating layer 13 of the barrier component 10. The wave structure 80 may additionally be formed in other layers of the barrier component 10, such as the polymeric buffer layer 14. In various embodiments, the wave structure 80 is formed in the inorganic coating layer 13 while forming the foldable packaging film 30. For example, the wave structure 80 may be formed while coupling (or attaching) the barrier component 10 to the base component 26 through the polymeric adhesive layer 25 during an extrusion lamination process.

[0154]

[0120] In some embodiments, the wave structure 80 is formed in the inorganic coating layer 13 after one or more components of the foldable packaging film 30 are subjected to a heat exposure (e.g., a heat treatment, a heat loading process) at a temperature above the shrink onset temperature. The heat exposure causes the polymeric substrate layer 12 to shrink, exerting compressive forces on the polymeric buffer layer 14. The compressive forces may in turn cause the polymeric buffer layer 14, which has a relatively lower modulus, to become pliable, allowing the attached inorganic coating layer 13, which has a relatively higher modulus, to take on the wave structure 80. In Attorney Docket No. 21406-WO addition to the inorganic coating layer 13, in some embodiments, the wave structure 80 is also formed in the polymeric buffer layer 14.

[0155]

[0121] Referring to Figure 2, which shows a portion of the cross-sectional view of the foldable packaging film 30 of Figure 1 , the wave structure 80 in the inorganic coating layer 13 is characterized by an amplitude 82 measurable in the z-direction and a wavelength 84 measurable in the x-y direction. In some embodiments, the wave structure 80 is positioned between and in direct contact with the polymeric adhesive layer 25 and the polymeric buffer layer 14.

[0156]

[0122] For embodiments of the barrier component 10 in which the wave structure 80 is formed, an average amplitude of the wave structure 80 may be between 0.05 pm and

[0157] 1 .0 pm or between 0.4 pm and 1 .0 pm. The wavelength 84 of the wave structure 80 may be between 1 .0 pm and 5.0 pm. The wave structure 80 may also be characterized by a ratio of the wavelength 84 to the average amplitude of between 1 and 100, or between 1 and 12.5.

[0158]

[0123] For embodiments of the barrier component 10 that include the wave structure 80 formed in the inorganic coating layer 13, the thickness of the polymeric buffer layer 14 may be between 1 .05 and 100 times the average amplitude of the wave structure 80. In some embodiments, the thickness of the polymeric buffer layer 14 may be between 1 .5 and 5 times the average amplitude of the wave structure 80.

[0159]

[0124] In some embodiments, before being exposed at elevated temperatures, the barrier component 10 may have an average OTR value that is less than 2 cm3 / m2 / day, less than 1 cm3 / m2 / day, less than 0.5 cm3 / m2 / day, or less than 0.1 cm3 / m2 / day (measured according to ASTM F1927 using conditions of 1 atmosphere, 23°C and 50% RH).

[0160]

[0125] The wave structure 80 may be formed when the barrier component 10 is exposed to temperatures above the shrink onset temperature of the barrier component 10 (e.g., the polymeric substrate layer 12). This may happen in any type of heat treatment process. For example, during or after the conversion of the barrier component 10, the barrier component 10 may be heated by a roller or an oven. The roller should be heated to a temperature that is capable of raising the barrier component 10 to a Attorney Docket No. 21406-WO temperature above the shrink onset temperature of the barrier component 10, causing the wave structure 80 to form. This barrier component 10 can then be used in a packaging application or for another use. Alternatively, the barrier component 10 may be exposed to temperatures above the shrink onset temperature during or after forming the material into a package, filling with product, and hermetically sealing it closed. The elevated temperature may be part of a pasteurization process, if applicable. Again, the elevated temperature should be greater than the shrink onset temperature of the barrier component 10, thereby causing the wave structure 80 to form.

[0161]

[0126] Figure 3 shows a cross-sectional view of an embodiment of the barrier component 10 before forming the wave structure 80 therein, i.e., in a pre-shrunk configuration. As described herein, the barrier component 10 includes the polymeric substrate layer 12, the inorganic coating layer 13, and the polymeric buffer layer 14 positioned between the polymeric substrate layer 12 and the inorganic coating layer 13. In some embodiments, before the formation of the wave structure 80, the barrier component 10 as shown in Figure 3 is free of any attachment to the base component 26, such that the inorganic coating layer 13 is an exterior layer of the barrier component 10. In some embodiments, the barrier component 10 as shown in Figure 3 has not undergone any exposure at a temperature above the shrink onset temperature of the polymeric substrate layer 12.

[0162]

[0127] The barrier component 10 may also include additional layers. For example, referring to Figure 4, the barrier component 10 includes the polymeric substrate layer 12, the inorganic coating layer 13, and the polymeric buffer layer 14 positioned between the polymeric substrate layer 12 and the inorganic coating layer 13. The polymeric buffer layer 14 is in direct contact with the inorganic coating layer 13. The polymeric buffer layer 14 may be in direct contact with the polymeric substrate layer 12, as shown in Figure 3, or there may be one or more additional layers between them. The barrier component 10 may also include a second polymeric buffer layer 15, located on a surface (i.e., an exterior surface) of the inorganic coating layer 13 opposite to the polymeric buffer layer 14, and in direct contact with the inorganic coating layer 13. For embodiments in which the second polymeric buffer layer 15 is included in the barrier component 10, the second polymeric buffer layer 15 also has a relatively lower modulus Attorney Docket No. 21406-WO

[0163] (i.e., similar to the polymeric buffer layer 14) at or above the shrink onset temperature, and the second buffer layer 15 is pliable to allow the formation of the wave structure 80 in at least the inorganic coating layer 13. Alternatively, there may be additional layers (i.e., non-buffer layers) attached to the inorganic coating layer 13.

[0164]

[0128] Still referring to Figure 4, the barrier component 10 may further include an exteriorly located heat seal layer 16. The heat seal layer 16 allows for the formation of a package by heat sealing to itself or another component. The heat seal layer 16 may comprise a polymeric material. The heat seal layer 16 may comprise a formula of polymers designed to reduce the heat seal initiation temperature to compliment the heat resistance of the opposite exterior surface.

[0165]

[0019] As shown in Figures 1 , 3, and 4, the polymeric substrate layer 12 may be located on the exterior of the barrier component 10. However, there may be additional layers added to the barrier component 10 such that the polymeric substrate layer 12 is an interior layer of the barrier component 10. For example, a heat seal layer may be applied to the surface of the polymeric substrate layer 12 opposite of the polymeric buffer layer 14.

[0166]

[0130] Figure 6 shows an embodiment of a method 100 of forming the barrier component 10 before laminating it with the base component 26 to produce the foldable packaging film 30 described herein. The method 100 includes providing the polymeric substrate layer 12 at step 102. The method 100 includes applying the polymeric buffer layer 14 to a surface of the polymeric substrate layer 12 at step 104. In some embodiments, the polymeric buffer layer 14 is applied to polymeric substrate layer 12 by a technique including extrusion, lacquering, spray coating, or solvent evaporation.

[0167]

[0131] The method 100 further includes applying the inorganic coating layer 13 to a first surface of the polymeric buffer layer 14 at step 106. In this regard, the first surface of the polymeric buffer layer 14 is in direct contact with the inorganic coating layer 13, and a second surface of the polymeric buffer layer 14 opposite to the inorganic coating layer 13 is in direct contact with the polymeric substrate layer 12. In some embodiments, the inorganic coating layer 13 is applied to the polymeric buffer layer 14 by a technique of Attorney Docket No. 21406-WO vacuum deposition. The application of the inorganic coating layer 13 may be completed in-line with and subsequent to the application of the polymeric buffer layer 14.

[0168]

[0132] Figure 7 shows an embodiment of a method 110 of producing (or forming) the foldable packaging film 30 described herein. The method 110 includes providing the base component 26 at step 112. The method 110 includes providing (or forming) the barrier component 10, as shown in Figure 3, at step 114. In some embodiments, the step of providing the barrier component 10 is performed via the method 100 as shown in Figure 6. The method 110 further includes extruding a melt curtain of the polymeric adhesive layer 25 (i.e., the extrudate) between the base component 26 and the barrier component 10 at step 116, thereby connecting them and forming the foldable packaging film 30.

[0169]

[0133] The step of extruding the melt curtain of the polymeric adhesive layer 25 at step 116 is implemented during an extrusion lamination process, which includes coupling (or bonding) a surface of the base component 26 with the inorganic coating layer 13 via the melted polymeric adhesive layer 25, thereby forming the melt curtain between the base component 26 and the barrier component 10, as shown in Figure 1 .

[0170]

[0134] In some embodiments, the melting of the polymeric adhesive layer 25 during the extrusion lamination process heats the barrier component 10 to a temperature above the shrink onset temperature of the polymeric substrate layer 12, resulting in the formation of the wave structure 80 in the inorganic coating layer 13 of the barrier component 10 as shown in Figure 1 . In other words, performing the extrusion lamination process at step 116 transforms the barrier component 10 of Figure 3, which is in the pre-shrunk configuration, into the barrier component 10 of Figure 1 , which is in the postshrunk configuration, while coupling the transformed barrier component 10 to the base component 26 via the polymeric adhesive layer 25. In some embodiments, the barrier component 10 in the post-shrunk configuration includes the wave structure 80 in both the inorganic coating layer 13 and the polymeric buffer layer 14.

[0171]

[0135] In some embodiments, the shrinkage of the barrier component 10 is not only caused by the melting of the polymeric adhesive layer 25, but also caused by a cooling drum with which all the components of the foldable packaging film 30 come into contact. Attorney Docket No. 21406-WO

[0172] A temperature of such a cooling drum may also influence the formation of the wave structure 80 in the barrier component 10. In some examples, the temperature of the cooling drum is above 60° C.

[0173]

[0136] The extrusion lamination process of step 116 may include the application of a primer (not shown) to the barrier component 10 prior to entering the nip and meeting the melt curtain of the polymeric adhesive layer 25. The primer may be applied and subsequently dried in a primer oven. Without being held to theory, the heat of the primer oven may provide enough heat to either partially or fully shrink the polymeric substrate layer 12. In other words, the shrink and wave formation may be completely or partially completed by the primer oven heat, the extrusion lamination melt curtain heat, or both. In some embodiments, the barrier component 10 is subjected to a preheating step, which may also cause the wave structure 80 to form therein.

[0174]

[0137] Figure 8 shows an embodiment of a method 120 of producing a folded package from the foldable packaging film 30 described herein. The method 120 includes providing (or producing) the foldable packaging film 30 that includes the base component 26 coupled to the barrier component 10 at step 122, where the barrier component 10 includes the wave structure 80. In some embodiments, the process of providing the foldable packaging film 30 at step 122 is performed via the method 110 as shown in Figure 7. The method 120 includes heating the foldable packaging film 30 to a folding temperature that is above room temperature, which is approximately 23 °C, at step 124. The method 120 includes folding the foldable packaging film 30 at step 126 to form a package. The method 120 includes filling the package with a product (e.g., a food product) at step 128. The method 120 further includes sealing (e.g., hermetically sealing) the package at step 130. In some embodiments, the step of heating the foldable packaging film 30 is performed before the step of folding of the foldable packaging film 30. In some embodiments, the heating of the foldable packaging film 30 and the folding of the foldable packaging film 30 are performed simultaneously.

[0175]

[0138] During the folding process performed at step 126, folding forces are exerted (or applied) on the components of the barrier component 10. Figure 9 schematically shows the types and directions of the folding forces exerted on the inorganic coating layer 13 Attorney Docket No. 21406-WO during the folding process performed at step 126. The type of folding forces exerted on the inorganic coating layer 13 is determined based on the location of the inorganic coating layer 13 with respect to the fold direction. For example, if the inorganic coating layer 13 is located on an inner side of the fold, the folding forces are compressive. On the contrary, if the inorganic coating layer 13 is located on an outer side of the fold, the folding forces will be extensive (or tensile).

[0176]

[0139] Generally, the folding forces compel the wave structure 80 in the barrier component 10 to arrange in or along the direction of the folding forces. Thermal energy provided by heating the barrier component 10 (i.e., the foldable packaging film 30) to the folding temperature, which is greater than 85 °C (e.g., at approximately 90 °C to approximately 100 °C) helps facilitate such rearrangement of the wave structure 80, which reduces cracking of the inorganic coating layer 13. In some embodiments, the folded foldable packaging film 30 has a substantially reduced amount of cracks (or may be substantially crack-free in some instances), thereby preserving the barrier properties of the barrier component 10 within a desired range. In some embodiments, the resulting fold formed by performing the method 120 exhibits dead fold properties (i.e., is a dead fold). That is, the fold cannot be undone in a spontaneous manner.

[0177]

[0140] The folding temperature implemented at step 124 may be determined based on at least one of the composition of the polymeric substrate layer 12, the composition of the polymeric buffer layer 14, or the thickness of the inorganic coating layer 13. In some embodiments, the folding temperature is greater than 85 °C. In some embodiments, the heating of the foldable packaging film 30 at step 124 is implemented during a film sterilization process.

[0178]

[0141] In some embodiments, heating the foldable packaging film 30 during the folding process causes the polymeric buffer layer 14 to change shape and support the folding (or bending) of the inorganic coating layer 13. In this regard, the folding temperature implemented at step 124 should be high enough to soften the polymeric buffer layer 14, resulting in a more pliable (i.e., having a lower stiffness or modulus) polymeric buffer layer 14 to accommodate the folding of the inorganic coating layer 13. Attorney Docket No. 21406-WO

[0179]

[0142] In some embodiments, softening the polymeric buffer layer 14 also forms the wave structure 80 in the barrier component 10. Accordingly, the folding temperature may be substantially similar to the temperature suitable for forming the wave structure 80 (i.e., above the shrink onset temperature of the barrier component 10). In one example where the polymeric substrate layer 12 includes BOPP and the polymeric buffer layer 14 includes a lacquer, the folding temperature is greater than 90 °C. In another example where the polymeric substrate layer 12 includes MDOPE and the polymeric buffer layer 14 includes EVOH, the folding temperature is greater than 85 °C. In some embodiments, heating the foldable packaging film 30 to above the folding temperature or above the shrink onset temperature causes the polymeric buffer layer 14 to soften and exhibit a modulus between 0.1 MPa and 100 MPa.

[0180]

[0143] It is noted that the wave structure 80 may be completely or partially formed at one or more of the various steps of the method 100, the method 110, and the method 120 during which a heat treatment process (or a heat load) is performed. In some embodiments, the wave structure 80 is formed in the barrier component 10 before coupling it to the base component 26. In one such example, the wave structure 80 may be formed when applying the inorganic coating layer 13 to the first surface of the polymeric buffer layer 14 via the vacuum deposition process, or another deposition process provided herein, at the step 106 of the method 100. In another such example, the wave structure 80 may be formed while imprinting the polymeric buffer layer 14 with a pressure roller. In yet another such example, the wave structure 80 may be formed by the heat load applied during the extrusion lamination process from the extrudate (i.e., the melt curtain of the polymeric adhesive layer 25) at step 1 16 of the method 1 10.

[0181]

[0144] In some embodiments, the wave structure 80 is formed while coupling the barrier component 10 to the base component 26. In one such example, the wave structure 80 may be formed while performing the extrusion lamination process at step 116 of the method 110 described herein. In another such example, the wave structure 80 may be formed while applying the primer to the barrier component 10 prior to entering the nip and meeting the melt curtain of the polymeric adhesive layer 25 in the primer oven as described above. In some embodiments, the wave structure 80 is formed during the folding process. For example, the wave structure 80 may be formed while heating the Attorney Docket No. 21406-WO foldable packaging film 30 at step 124 and folding the foldable packaging film 30 at step 126 of the method 120.

[0182] EXAMPLES & DATA

[0183]

[0145] Figure 10A shows an example optical microscopy image of a barrier component 10 with the wave structure 80 and folded at a folding temperature of approximately 100 °C, and Figure 10B shows an example optical microscopy image of a barrier component 10 without a wave structure 80. The inorganic coating layer 13 of the barrier component 10 in each of Figures 10A and 10B was located on an inner side of the fold, indicating that the folding forces were compressive. A folding axis (FA) of each of the barrier component 10 is indicated in the corresponding figures. The polymeric substrate layer 12 of each of the barrier component 10 included biaxially oriented polypropylene (BOPP), the polymeric buffer layer 14 of each of the barrier component 10 included a lacquer, and the inorganic coating layer 13 of each of the barrier component 10 included SiOx.

[0184]

[0146] Referring to Figure 10B, in the absence of the wave structure 80, the inorganic coating layer 13 cracked in the region of the fold and in a direction parallel to the FA. In contrast, referring to Figure 10A, when the barrier component 10 includes the wave structure 80 and is folded at the folding temperature above room temperature, the wave structure 80 rearranged itself in the region of the fold and in a direction parallel to the FA, thereby keeping the inorganic coating layer 13 substantially intact.

[0185]

[0147] Figure 11 shows an atomic force microscopy (AFM) image of a barrier component 10 without the wave structure 80 (e.g., in its pre-shrunk configuration) and was folded at room temperature. The inorganic coating layer 13 of the barrier component 10 was located on an inner side of the fold, indicating that the folding forces were compressive. An FA of the fold made in the barrier component 10 is marked in the figure for reference. The polymeric substrate layer 12 of the barrier component 10 included biaxially oriented polypropylene (BOPP), the polymeric buffer layer 14 of the barrier component 10 included a lacquer, and the inorganic coating layer 13 of the Attorney Docket No. 21406-WO barrier component 10 included SiOx. Cracks were formed in the inorganic coating layer 13 and are shown to extend generally parallel to the FA.

[0186]

[0148] Figure 12A shows an example optical microscopy image of a barrier component 10 with the wave structure 80 and folded at a folding temperature of approximately 100 °C, and Figure 12B shows an example optical microscopy image of a barrier component 10 with a wave structure 80 and folded at room temperature. The inorganic coating layer 13 of the barrier component 10 in each of Figures 12A and 12B was located on an inner side of the fold, indicating that the folding forces were compressive. An FA of each of the barrier component 10 is indicated in the corresponding figures. The polymeric substrate layer 12 of each of the barrier component 10 included biaxially oriented polypropylene (BOPP), the polymeric buffer layer 14 of each of the barrier component 10 included a lacquer, and the inorganic coating layer 13 of each of the barrier component 10 included SiOx.

[0187]

[0149] Referring to Figure 12A, when the barrier component 10 was folded at an elevated temperature, the wave structure 80 rearranged to extend generally parallel to the FA, resulting in the inorganic coating layer 13 to remain substantially intact (i.e., substantially without cracks). Referring to Figure 12B, when the barrier component 10 was folded at room temperature, the wave structure 80 did not prevent cracks to form in the inorganic coating layer 13.

[0188]

[0150] Figures 13A and 13B each show an example optical microscopy image of a barrier component 10 with the wave structure 80 and folded at a folding temperature of approximately 100 °C. The inorganic coating layer 13 of the barrier component 10 in each of Figures 13A and 13B was located on an inner side of the fold, indicating that the folding forces were compressive. An FA of each of the barrier component 10 is indicated in the corresponding figures. The polymeric substrate layer 12 of each of the barrier component 10 included monoaxially oriented polyethylene (MDOPE), the polymeric buffer layer 14 of each of the barrier component 10 included ethylene vinyl alcohol copolymer (EVOH), and the inorganic coating layer 13 of each of the barrier component 10 included SiOx. Each of the barrier component 10 of Figures 13A and 13B was shrunk only in a cross direction (CD, or transverse direction, TD), which is generally Attorney Docket No. 21406-WO perpendicular to a machine direction (MD) of the polymeric substrate layer 12. Accordingly, the wave structure 80 formed in each of the barrier component 10 extended in a direction generally parallel to the CD.

[0189]

[0151] However, since the barrier component 10 of Figure 13A was folded along an FA that is generally perpendicular to the CD (i.e., generally parallel to the MD), the wave structure 10 did not rearrange itself and remained to extend in the direction generally parallel to the CD, which did not prevent cracking of the inorganic coating layer 13. In contrast, the barrier component 10 of Figure 13B was folded along an FA that is generally parallel to the CD (i.e., generally perpendicular to the MD), the wave structure 10 rearranged itself generally parallel to the CD, allowing the inorganic coating layer 13 to remain substantially intact.

[0190]

[0152] Furthermore, Table 1 below illustrates OTR data of samples of a barrier component 10 with and without the formation of the wave structure 80. The barrier component 10 of each of Sample 1 , Sample 2, and Sample 3 included biaxially oriented polypropylene (BOPP) in the polymeric substrate layer 12, a lacquer in the polymeric buffer layer 14, and SiOx in the inorganic coating layer 13. Sample 1 and Sample 2 each included the wave structure 80, and Sample 3 did not include the wave structure 80.

[0191]

[0153] The samples were prepared by folding 180° along an FA in both the MD and the CD. The inorganic coating layer 13 of each barrier component 10 was located on an inner side of the fold, indicating that the folding forces were compressive. The benefits of the formation of the wave structure 80 and of performing the folding process at elevated temperature in keeping the inorganic coating layer 13 substantially intact can be observed by comparing the samples’ OTR data after being folded at a folding temperature above room temperature with those after being folded at room temperature.

[0192]

[0154] After being folded at room temperature, such as that shown in Figure 12B, the wave structure 80 of Sample 1 or Sample 2 did not rearrange along the FA and cracks developed in the inorganic coating layer 13. In contrast, after being folded at a suitable folding temperature, the wave structure 80 in Sample 1 and Sample 2 rearranged itself Attorney Docket No. 21406-WO along the FA, thereby keeping their respective inorganic coating layer 13 substantially intact. Furthermore, after being folded at the folding temperature, the OTR of each of Sample 1 and Sample 2 was two times less than the OTR of the same corresponding samples after being folded at room temperature, indicating retention of barrier properties after performing the folding process at elevated folding temperatures.

[0193] Table 1 . OTR data for samples of a barrier component with and without a wave structure.

[0194] Embodiments

[0195] Clause 1. A foldable packaging film comprising: a base component; and a barrier component coupled to the base component, the barrier component comprising: a polymeric substrate layer, an inorganic coating layer, a polymeric buffer layer positioned between the polymeric substrate layer and the inorganic coating layer, the polymeric buffer layer in direct contact with the inorganic coating layer, and a shrink onset temperature, wherein: the polymeric substrate layer comprises a free shrink of between 0.5% and 50% in at least one of a machine direction or a transverse direction at the shrink onset temperature according to ASTM D2732, the inorganic coating layer comprises a thickness between 0.005 pm and 0.1 pm, the polymeric buffer layer comprises a thickness between 0.5 pm and 12 pm, a ratio of the thickness of the polymeric buffer layer to the thickness of the inorganic coating layer is comprised between 20 and 500, and the polymeric buffer layer comprises a Youngs modulus at the Attorney Docket No. 21406-WO shrink onset temperature, comprised between 0.1 and 100 MPa, as calculated from measurements collected according to ASTM E2546-15 with Annex X.4.

[0196] Clause 2. The foldable packaging film of clause 1 , wherein the base component is fiberbased.

[0197] Clause 3. The foldable packaging film of clause 1 , wherein the base component is polymer-based.

[0198] Clause 4. The foldable packaging film of any of clauses 1 -3, wherein the base component is configured to form a fold having dead fold properties.

[0199] Clause 5. The foldable packaging film of any of clauses 1 -4, further comprising a polymeric adhesive layer coupling the base component to the barrier component.

[0200] Clause 6. The foldable packaging film of any of clauses 1 -5, wherein the thickness of the polymeric buffer layer is between 1 pm and 5 pm.

[0201] Clause 7. The foldable packaging film of any of clauses 1 -6, wherein: the inorganic coating layer comprises a metal oxide coating layer or a metalloid oxide coating layer, and the thickness of the inorganic coating layer is between 0.005 pm and 0.06 pm.

[0202] Clause 8. The foldable packaging film of any of clauses 1 -7, wherein a ratio of the thickness of the polymeric buffer layer to the thickness of the inorganic coating layer is between 30 and 120.

[0203] Clause 9. The foldable packaging film of any of clauses 1 -8, wherein: the polymeric substrate layer comprises a monoaxially oriented polypropylene film, a biaxially oriented polypropylene film, a monoaxially oriented polyethylene film, a biaxially oriented polyethylene film, a biaxially oriented polyamide film, a biaxially oriented EVOH film, a monoaxially oriented polyester film, a biaxially oriented polyester film, a monoaxially oriented polylactic acid film, or a biaxially oriented polylactic acid film, and the polymeric substrate layer comprises a thickness between 4.5 pm and 100 pm.

[0204] Clause 10. The foldable packaging film of any of clauses 1 -8, wherein the polymeric substrate layer comprises an oriented polyolefin film. Attorney Docket No. 21406-WO

[0205] Clause 11 . The foldable packaging film of any of clauses 1 -10, wherein the free shrink of the polymeric substrate layer is between 1 % and 6 % at the shrink onset temperature according to ASTM D2732.

[0206] Clause 12. The foldable packaging film of any of clauses 1 -1 1 , wherein the polymeric buffer layer comprises a vinyl alcohol copolymer, polypropylene, polyurethane, polylactic acid, polybutylene succinate, polybutylene adipate terephthalate, a cyclic olefin copolymer, or an ethylene vinyl acetate copolymer.

[0207] Clause 13. The foldable packaging film of clause any of clauses 1 -12, further comprising a second polymeric buffer layer in direct contact with the inorganic coating layer.

[0208] Clause 14. The foldable packaging film of any of clauses 1 -13, further comprising one or more additional polyolefin layers.

[0209] Clause 15. The foldable packaging film of any of clauses 1 -14, wherein: the polymeric substrate layer comprises biaxially oriented polypropylene having a thickness between 10 pm and 50 pm, the inorganic coating layer comprises aluminum oxide (AIOx) or silicon oxide (SiOx), the thickness of the inorganic coating layer is between 0.01 pm and 0.1 pm, the polymeric buffer layer comprises polyurethane, and the thickness of the polymeric buffer layer is between 1 .0 pm and 2.5 pm.

[0210] Clause 16. The foldable packaging film of any of clauses 1 -16, wherein: the polymeric substrate layer comprises a monoaxially oriented polyethylene film, the polymeric buffer layer comprises a vinyl alcohol copolymer, and the inorganic coating layer comprises aluminum oxide (AIOx) or silicon oxide (SiOx).

[0211] Clause 17. A foldable packaging film comprising: a base component; a barrier component comprising: i) a polymeric substrate layer, ii) an inorganic coating layer comprising a wave structure characterized by an average amplitude between 0.05 pm and 1 .0 pm and a wavelength between 1 .0 pm and 5.0 pm, and iii) a polymeric buffer layer positioned between the polymeric substrate layer and the inorganic coating layer, the polymeric buffer layer in direct contact with the inorganic coating layer, the polymeric buffer layer comprising a thickness between 1 .0 pm and 5.0 pm that is Attorney Docket No. 21406-WO between 1 .05 and 100 times the average amplitude of the wave structure; and a polymeric adhesive layer coupling the base component to the barrier component.

[0212] Clause 18. The foldable packaging film of clause 17, wherein the base component is fiber-based.

[0213] Clause 19. The foldable packaging film of clause 17, wherein the base component is polymer-based.

[0214] Clause 20. The foldable packaging film of any of clauses 17-19, wherein the base component is configured to form a fold having dead fold properties.

[0215] Clause 21 . The foldable packaging film of any of clauses 17-20, wherein the wave structure of the inorganic coating layer is characterized by a ratio of the wavelength to the average amplitude between 1 and 100.

[0216] Clause 22. The foldable packaging film of any of clauses 17-21 , wherein: the inorganic coating layer comprises a metal oxide coating layer or a metalloid oxide, and a thickness of the inorganic coating layer is between 0.005 pm and 0.1 pm.

[0217] Clause 23. The foldable packaging film of any of clauses 17-22, wherein the polymeric substrate layer comprises a monoaxially oriented polypropylene film, a biaxially oriented polypropylene film, a monoaxially oriented polyethylene film, a biaxially oriented polyethylene film, a biaxially oriented polyamide film, a biaxially oriented EVOH film, a monoaxially oriented polyester films, a biaxially oriented polyester film, a monoaxially oriented polylactic acid film, or a biaxially oriented polylactic acid film.

[0218] Clause 24. The foldable packaging film of any of clauses 17-23, wherein the polymeric substrate layer comprises an oriented polyolefin film.

[0219] Clause 25. The foldable packaging film of any of clauses 17-24, wherein the polymeric buffer layer comprises polypropylene, polyurethane, polylactic acid, polybutylene succinate, polybutylene adipate terephthalate, a cyclic olefin copolymer, a vinyl alcohol copolymer, or an ethylene vinyl acetate copolymer.

[0220] Clause 26. The foldable packaging film of any of clauses 17-25, further comprising a second polymeric buffer layer in direct contact with the inorganic coating layer. Attorney Docket No. 21406-WO

[0221] Clause 27. The foldable packaging film of any of clauses 17-26, further comprising one or more additional polyolefin layers.

[0222] Clause 28. The foldable packaging film of any of clauses 17-27, wherein: the polymeric substrate layer comprises a biaxially oriented polypropylene film with a thickness between 10 pm and 50 pm, the inorganic coating layer comprises vacuum deposited aluminum oxide (AIOx) or silicon oxide (SiOx), a thickness of the inorganic coating layer is between 0.01 pm and 0.1 pm, and the average amplitude of the wave structure is between 0.4 pm and 1 .0 pm.

[0223] Clause 29. The foldable packaging film of any of clauses 17-28, wherein: the polymeric substrate layer comprises a monoaxially oriented polyethylene film, the polymeric buffer layer comprises vinyl alcohol copolymer, the inorganic coating layer comprises vacuum deposited aluminum oxide (AIOx) or silicon oxide (SiOx), the average amplitude of the wave structure is between 0.15 pm and 1 .0 pm, and the wavelength of the wave structure is comprised between 1 .0 pm and 4.0 pm.

[0224] Clause 30. The foldable packaging film of clause any of clauses 17-29, wherein the polymeric buffer layer comprises polyurethane.

[0225] Clause 31 . The foldable packaging film of any of clauses 17-30, wherein: the foldable packaging film comprises a folding axis along which a fold is formed, and the wave structure is arranged parallel to the folding axis.

[0226] Clause 32. A method for producing the foldable packaging film of any of clauses 17 through 31 , comprising the steps of: providing the base component; forming the barrier component; and extruding a melt curtain of the polymeric adhesive layer between the base component and the barrier component in an extrusion lamination process, thereby coupling the base component to the barrier component, wherein the step of extruding the melt curtain of the polymeric adhesive layer causes the wave structure to form in the inorganic coating layer.

[0227] Clause 33. The method of producing the foldable packaging film of clause 32, wherein the step of forming the barrier component comprises the steps of: providing the polymeric substrate layer, applying the polymeric buffer layer to a surface of the Attorney Docket No. 21406-WO polymeric substrate layer by techniques comprising extrusion, lacquering, spray coating, or solvent evaporation, and applying the inorganic coating layer to a surface of the polymeric buffer layer by vacuum deposition.

[0228] Clause 34. A method of producing a folded package, comprising the steps of: providing the foldable packaging film of any of clauses 17 through 31 ; heating the foldable packaging film to a folding temperature that is above room temperature; folding the foldable packaging film along a folding axis to form a package; and sealing the package.

[0229] Clause 35. The method of producing the folded package of clause 34, wherein the folding temperature is greater than 85 °C.

[0230] Clause 36. The method of producing the folded package of clause 34 or 35, wherein the step of folding the foldable packaging film results in a fold having dead fold properties.

[0231] Clause 37. A hermetically sealed package comprising the foldable packaging film of any of clauses 1 through 31 .

[0232] Clause 38. A method of producing a shelf-stable packaged product, the method comprising the steps of: providing the foldable packaging film of any of clauses 17 through 31 ; heating the foldable packaging film to a folding temperature that is above room temperature; folding the foldable packaging film along a folding axis to form a package; filling the package with a product; and hermetically sealing the product inside the package to form a packaged product.

Claims

Attorney Docket No. 21406-WOWhat is claimed is:1 . A foldable packaging film comprising: a base component; and a barrier component coupled to the base component, the barrier component comprising: a polymeric substrate layer, an inorganic coating layer, a polymeric buffer layer positioned between the polymeric substrate layer and the inorganic coating layer, the polymeric buffer layer in direct contact with the inorganic coating layer, and a shrink onset temperature, wherein: the polymeric substrate layer comprises a free shrink of between 0.5% and 50% in at least one of a machine direction or a transverse direction at the shrink onset temperature according to ASTM D2732, the inorganic coating layer comprises a thickness between 0.005 pm and 0.1 pm, the polymeric buffer layer comprises a thickness between 0.5 pm and 12 pm, a ratio of the thickness of the polymeric buffer layer to the thickness of the inorganic coating layer is comprised between 20 and 500, and the polymeric buffer layer comprises a Youngs modulus at the shrink onset temperature, comprised between 0.1 and 100 MPa, as calculated from measurements collected according to ASTM E2546-15 with Annex X.4.

2. The foldable packaging film of claim 1 , wherein the base component is fiberbased.Attorney Docket No. 21406-WO3. The foldable packaging film of claim 1 , wherein the base component is polymer- based.

4. The foldable packaging film of claim 1 , wherein the base component is configured to form a fold having dead fold properties.

5. The foldable packaging film of claim 1 , further comprising a polymeric adhesive layer coupling the base component to the barrier component.

6. The foldable packaging film of claim 1 , wherein the thickness of the polymeric buffer layer is between 1 pm and 5 pm.

7. The foldable packaging film of claim 1 , wherein: the inorganic coating layer comprises a metal oxide coating layer or a metalloid oxide coating layer, and the thickness of the inorganic coating layer is between 0.005 pm and 0.06 pm.

8. The foldable packaging film of claim 1 , wherein a ratio of the thickness of the polymeric buffer layer to the thickness of the inorganic coating layer is between 30 and 120.

9. The foldable packaging film of claim 1 , wherein: the polymeric substrate layer comprises a monoaxially oriented polypropylene film, a biaxially oriented polypropylene film, a monoaxially oriented polyethylene film, a biaxially oriented polyethylene film, a biaxially oriented polyamide film, a biaxially oriented EVOH film, a monoaxially oriented polyester film, a biaxially oriented polyester film, a monoaxially oriented polylactic acid film, or a biaxially oriented polylactic acid film, and the polymeric substrate layer comprises a thickness between 4.5 pm and 100 pm.

10. The foldable packaging film of claim 1 , wherein the polymeric substrate layer comprises an oriented polyolefin film.Attorney Docket No. 21406-WO1 1 . The foldable packaging film of claim 1 , wherein the free shrink of the polymeric substrate layer is between 1 % and 6 % at the shrink onset temperature according to ASTM D2732.

12. The foldable packaging film of claim 1 , wherein the polymeric buffer layer comprises a vinyl alcohol copolymer, polypropylene, polyurethane, polylactic acid, polybutylene succinate, polybutylene adipate terephthalate, a cyclic olefin copolymer, or an ethylene vinyl acetate copolymer.

13. The foldable packaging film of claim 1 , further comprising a second polymeric buffer layer in direct contact with the inorganic coating layer.

14. The foldable packaging film of claim 1 , further comprising one or more additional polyolefin layers.

15. The foldable packaging film of claim 1 , wherein: the polymeric substrate layer comprises biaxially oriented polypropylene having a thickness between 10 pm and 50 pm, the inorganic coating layer comprises aluminum oxide (AIOx) or silicon oxide (SiOx), the thickness of the inorganic coating layer is between 0.01 pm and 0.1 pm, the polymeric buffer layer comprises polyurethane, and the thickness of the polymeric buffer layer is between 1 .0 pm and 2.5 pm.

16. The foldable packaging film of claim 1 , wherein: the polymeric substrate layer comprises a monoaxially oriented polyethylene film, the polymeric buffer layer comprises a vinyl alcohol copolymer, and the inorganic coating layer comprises aluminum oxide (AIOx) or silicon oxide (SiOx).Attorney Docket No. 21406-WO17. A foldable packaging film comprising: a base component; a barrier component comprising: i) a polymeric substrate layer, ii) an inorganic coating layer comprising a wave structure characterized by an average amplitude between 0.05 pm and 1 .0 pm and a wavelength between 1 .0 pm and 5.0 pm, and iii) a polymeric buffer layer positioned between the polymeric substrate layer and the inorganic coating layer, the polymeric buffer layer in direct contact with the inorganic coating layer, the polymeric buffer layer comprising a thickness between 1 .0 pm and 5.0 pm that is between 1 .05 and 100 times the average amplitude of the wave structure; and a polymeric adhesive layer coupling the base component to the barrier component.

18. The foldable packaging film of claim 17, wherein the base component is fiberbased.

19. The foldable packaging film of claim 17, wherein the base component is polymer-based.

20. The foldable packaging film of claim 17, wherein the base component is configured to form a fold having dead fold properties.

21. The foldable packaging film of claim 17, wherein the wave structure of the inorganic coating layer is characterized by a ratio of the wavelength to the average amplitude between 1 and 100.

22. The foldable packaging film of claim 17, wherein: the inorganic coating layer comprises a metal oxide coating layer or a metalloid oxide, and a thickness of the inorganic coating layer is between 0.005 pm and 0.1 pm.Attorney Docket No. 21406-WO23. The foldable packaging film of claim 17, wherein the polymeric substrate layer comprises a monoaxially oriented polypropylene film, a biaxially oriented polypropylene film, a monoaxially oriented polyethylene film, a biaxially oriented polyethylene film, a biaxially oriented polyamide film, a biaxially oriented EVOH film, a monoaxially oriented polyester films, a biaxially oriented polyester film, a monoaxially oriented polylactic acid film, or a biaxially oriented polylactic acid film.

24. The foldable packaging film of claim 17, wherein the polymeric substrate layer comprises an oriented polyolefin film.

25. The foldable packaging film of claim 17, wherein the polymeric buffer layer comprises polypropylene, polyurethane, polylactic acid, polybutylene succinate, polybutylene adipate terephthalate, a cyclic olefin copolymer, a vinyl alcohol copolymer, or an ethylene vinyl acetate copolymer.

26. The foldable packaging film of claim 17, further comprising a second polymeric buffer layer in direct contact with the inorganic coating layer.

27. The foldable packaging film of claim 17, further comprising one or more additional polyolefin layers.

28. The foldable packaging film of claim 17, wherein: the polymeric substrate layer comprises a biaxially oriented polypropylene film with a thickness between 10 pm and 50 pm, the inorganic coating layer comprises vacuum deposited aluminum oxide (AIOx) or silicon oxide (SiOx), a thickness of the inorganic coating layer is between 0.01 pm and 0.1 pm, and the average amplitude of the wave structure is between 0.4 pm and 1 .0 pm.Attorney Docket No. 21406-WO29. The foldable packaging film of claim 17, wherein: the polymeric substrate layer comprises a monoaxially oriented polyethylene film, the polymeric buffer layer comprises vinyl alcohol copolymer, the inorganic coating layer comprises vacuum deposited aluminum oxide (AIOx) or silicon oxide (SiOx), the average amplitude of the wave structure is between 0.15 pm and 1 .0 pm, and the wavelength of the wave structure is comprised between 1 .0 pm and 4.0 pm.

30. The foldable packaging film of claim 17, wherein the polymeric buffer layer comprises polyurethane.31 . The foldable packaging film of claim 17, wherein: the foldable packaging film comprises a folding axis along which a fold is formed, and the wave structure is arranged parallel to the folding axis.

32. A method for producing the foldable packaging film of any of claims 17 through 31 , comprising the steps of: providing the base component; forming the barrier component; and extruding a melt curtain of the polymeric adhesive layer between the base component and the barrier component in an extrusion lamination process, thereby coupling the base component to the barrier component, wherein the step of extruding the melt curtain of the polymeric adhesive layer causes the wave structure to form in the inorganic coating layer.Attorney Docket No. 21406-WO33. The method of producing the foldable packaging film of claim 32, wherein the step of forming the barrier component comprises the steps of: providing the polymeric substrate layer, applying the polymeric buffer layer to a surface of the polymeric substrate layer by techniques comprising extrusion, lacquering, spray coating, or solvent evaporation, and applying the inorganic coating layer to a surface of the polymeric buffer layer by vacuum deposition.

34. A method of producing a folded package, comprising the steps of: providing the foldable packaging film of any of claims 17 through 31 ; heating the foldable packaging film to a folding temperature that is above room temperature; folding the foldable packaging film along a folding axis to form a package; and sealing the package.

35. The method of producing the folded package of claim 34, wherein the folding temperature is greater than 85 °C.

36. The method of producing the folded package of claim 34, wherein the step of folding the foldable packaging film results in a fold having dead fold properties.

37. A hermetically sealed package comprising the foldable packaging film of any of claims 1 through 31 .Attorney Docket No. 21406-WO38. A method of producing a shelf-stable packaged product, the method comprising the steps of: providing the foldable packaging film of any of claims 17 through 31 ; heating the foldable packaging film to a folding temperature that is above room temperature; folding the foldable packaging film along a folding axis to form a package; filling the package with a product; and hermetically sealing the product inside the package to form a packaged product.

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