Laminate structure with recycling conditions for achieving optimal barrier in a folding package construction

Abstract

An improved construction for a multilayer recycle-ready film laminate for polyolefin-based packaging having a fold in the assembly. The recycle-ready laminate comprises a first layer, a second layer having a barrier layer on the second layer opposite the first layer, and a third layer. The first and third layers are outer layers of the laminate, wherein the first layer has a first major surface aligned with an exterior of the packaging and the third layer has a second major surface aligned with an interior of the packaging. The third layer is a seal layer. Positioning the barrier layer proximate the seal layer maintains and improves the barrier properties of the laminate when folded as compared to conventional standard recycle-ready laminates for packaging subjected to retort processing.

Description

Technical Field

[0001] This disclosure relates to an improved construction of a multilayer recyclable film for use in packaging, the packaging having a folded portion in an assembly. More specifically, this disclosure relates to a multilayer recyclable film in which the barrier layer position is selected to minimize the effect of compressive forces on the barrier layer when used in packaging where the assembly requires folding. Background Technology

[0002] There is a growing desire to design more sustainable flexible packaging structures. Increased sustainability can take the form of using raw materials from renewable resources, such as paper or starch-based polymers. Increased sustainability can also take the form of end-of-life solutions, which are something other than waste, such as recyclable options. For flexible packaging used in long-shelf-life food products, it can be difficult to match the required performance characteristics with any of these more sustainable options.

[0003] Beyond packaging design challenges, flexible packaging for moisture-rich food products must possess sufficient oxygen and water vapor barrier properties to maintain the integrity of the packaging and its contents during use. Typically, these packages require a shelf life of 3 to 18 months. In some packaging styles, such as, but not limited to, stand-up pouches (“SUPs”), a barrier layer exists as an interlayer between a pair of oriented film layers. In this construction, the barrier layer is protected by a pair of stably oriented film webs that are not easily shrunk or deformed, as deformation or shrinkage of the material adjacent to the barrier layer could cause cracks or small fissures within the barrier, thus affecting its barrier capabilities.

[0004] In addition to the normal requirements for flexible film laminates used in typical packaging, stand-up pouches require folding or creases during assembly to typically form accordion pleats. This folding of the flexible laminate generates compressive forces on each of the individual layers of the laminate, including the barrier layer placed within the assembly. When this barrier layer comprises inorganic barrier layers, such as alumina (“AlOx”) or silicon oxide (“SiOx”), the inherently brittle nature of these coatings makes them particularly susceptible to compressive cracking, leading to the possibility of barrier failure.

[0005] Therefore, in order to compensate for the brittle nature of these inorganic barrier coatings when used in recyclable flexible laminates for packaging components that require folding, improvements are needed to prevent the barrier components within these flexible laminates from cracking and deteriorating during use. Summary of the Invention

[0006] The development described herein involves multilayer membrane structures, which, compared to the use of multilayer membrane structures in packaging constructions containing folds, have specific layers at designated locations within the multilayer membrane structure. This folded area, typically in the form of accordion pleats within the packaging, is particularly susceptible to degradation of the barrier properties of the multilayer membrane due to the inherent compression and stress applied to the sensitive barrier layer material when positioned in this folded location. When folded packaging constructions are used for articles subjected to retort treatment, the protection of the sensitive barrier layer is enhanced due to the harsh conditions of high humidity, high temperature, and high pressure associated with typical retort processes.

[0007] In addition to the improved barrier properties associated with foldable packaging components, the multilayer film structures described herein consist of a combination of materials that enable the packaging to be considered recyclable or recyclable. Therefore, the materials comprising the multilayer film structure are composed of polyolefins, wherein they can be considered to include monopolyolefins, such as, but not limited to, monopolypropylene structures. This combination of similar materials enables the multilayer film comprising the packaging to be recycled in a dedicated recycling stream, such as, but not limited to, polypropylene-based or recycled streams.

[0008] The recyclable and / or recyclable multilayer film laminates disclosed herein are configured for use in specific packaging types that have folds or accordion pleats within their components, where the packaging typically defines an internal packaging space. The multilayer film laminate comprises a first polyolefin layer, a second layer, and a third layer. A second layer is adjacent to this first layer, wherein the second layer comprises a polyolefin of the same type as the polyolefin of the first layer. This second layer comprises a barrier layer, wherein this barrier layer is located on the second layer, positioned opposite an adjacent position of the first layer. A third layer is located near the barrier layer and forms a sealing layer, the sealing layer comprising a polyolefin of the same type as the polyolefins of the first and second layers, wherein the position of this third layer is aligned with the interior of the packaging. The positions of the first, second, barrier, and third layers relative to each other and the internal space of the packaging are specifically chosen to prevent loss of barrier properties when the laminate is placed in a folded position in a packaging assembly that requires folding.

[0009] In an alternative embodiment of the recyclable multilayer film laminate disclosed herein, the adhesive is placed between the first and second layers and between the barrier layer and the third layer.

[0010] In another embodiment and previous alternative embodiments of the recyclable multilayer membrane laminate according to this disclosure, the polyolefin of the first layer is polypropylene. Therefore, in order to maintain the recyclability of the multilayer membrane and its composition of a single-material structure, the selection of polypropylene for the first layer also requires that the second layer and the sealing layer are also composed of polypropylene.

[0011] In some embodiments, the barrier layer is selected to include an inorganic coating.

[0012] In another aspect, which can be combined with any other embodiment or aspect, the inorganic coating is selected to include a coating of aluminum oxide (AlOx) or silicon oxide (SiOx).

[0013] In another aspect, which can be combined with any other embodiment or aspect, the first layer and the second layer include orientation, wherein the first layer and the second layer include orientation layers.

[0014] In another aspect, which can be combined with any other aspect or embodiment, after the multilayer laminate is cooked at 127°C for 50 minutes, the oxygen permeability in the folded area, measured according to ASTM F1927 using conditions of 1 atmosphere, 23°C, and 50% RH, is approximately less than 1.0 cm⁻¹. 3 / m 2 / sky.

[0015] In one aspect, which can be combined with any other aspect or embodiment, this disclosure provides a recyclable laminate having a layered composition selected to optimize the integrity of barrier properties when used in folded packaging. The laminate comprises a first layer of oriented polyolefin having a first side and a second side opposite the first side, wherein the first side is the outer side and a first main surface. A second layer is an oriented polyolefin of the same type as the first layer, located near the second side of the first layer. The second layer comprises an inorganic barrier layer positioned opposite the first layer. A third layer forming a sealing layer and comprising a polyolefin of the same type as the first and second layers is located near the inorganic barrier layer, wherein the positioning of the third layer relative to the barrier layer is specifically selected to prevent loss of barrier properties by reducing tension on the barrier layer when the laminate is folded during packaging assembly.

[0016] In another aspect, which can be combined with any other aspect or embodiment, this disclosure provides a recyclable stand-up pouch and / or stand-up bag having folded portions or accordion pleats, wherein the folded portions or accordion pleats of the stand-up pouch comprise a multilayer film. The stand-up pouch is composed of a multilayer film comprising a first layer of oriented polyolefin, the outer surface of which is aligned with the exterior of the stand-up pouch. A second layer comprises an oriented polyolefin of the same type as the first layer, located near the first layer opposite the outer surface. An inorganic barrier layer is located on the second layer, opposite the first layer, wherein a sealing layer comprises a polyolefin of the same type as both the first and second layers, located near the inorganic barrier layer, opposite the second layer. The sealing layer has an inner surface positioned opposite the inorganic barrier layer, wherein the inner surface is aligned with the interior of the pouch. Specifically, the inorganic barrier layer is chosen to be adjacent to the sealing layer and facing inward relative to the first and second layers to prevent loss of the film's barrier properties when the film is manipulated during assembly of the stand-up pouch to form folded or accordion pleats. Attached Figure Description

[0017] This disclosure can be more fully understood by considering the following detailed description of various embodiments of the disclosure in conjunction with the accompanying drawings, wherein: Figure 1 This is a cross-sectional view of a first embodiment of a recyclable laminate with optimal barrier placement for use in packaging that requires folding; Figure 2 This is a cross-sectional view of another embodiment of a recyclable laminate with optimal barrier placement for use in packaging that requires folding; Figure 3 This is a cross-sectional view of a first embodiment of a recyclable laminate with optimal barrier placement for use in folded packaging; and the laminate is in a folded position. Figure 4 It is a cross-sectional view of a package with folds and including recyclable laminates with optimal barrier positions.

[0018] The accompanying drawings illustrate some, but not all, embodiments. The elements depicted in the drawings are illustrative and not necessarily drawn to scale, and throughout the drawings, the same (or similar) reference numerals denote the same (or similar) features. Detailed Implementation

[0019] The foregoing detailed description includes reference to the accompanying drawings, which form part of the detailed description. The drawings schematically illustrate specific embodiments in which the invention can be practiced. These embodiments, also referred to herein as “examples,” are described in sufficient detail to enable those skilled in the art to practice the invention. Combined embodiments, other embodiments, or structural and logical changes may be made without departing from the scope of the invention. Therefore, the following detailed description should not be construed as limiting. However, before such detailed description of the invention, it should be understood that the invention is not limited to the specific variations set forth, and changes are certainly possible.

[0020] definition As defined below, the following terms are used throughout.

[0021] As used herein and in the appended claims, unless otherwise specified herein or clearly contradicted by the context, singular articles such as “a / an” and “the”, and similar pronouns, in the context of describing elements (particularly in the context of the following claims) should be interpreted as encompassing both the singular and plural. Unless otherwise indicated herein, the enumeration of value ranges herein is intended only as a shorthand method for individually referring to each individual value falling within the range, and each individual value is incorporated into the specification as if it were individually enumerated herein. Unless otherwise stated herein or otherwise clearly contradicted by the context, all methods described herein may be performed in any suitable order. Unless otherwise stated, any and all examples or exemplary language provided herein ( For example The use of "for example" is merely intended to better illustrate the embodiments and does not limit the scope of the claims. No language in this specification should be construed as indicating that any non-claimed element is necessary.

[0022] As used herein, “about” will be understood by those skilled in the art and will vary to some extent depending on the context in which it is used. Where a term is not readily apparent to those skilled in the art, “about” will, in light of the context in which it is used, mean at most ±10% of a particular term—for example, “about 10 wt.%” will be understood to mean “9 wt.% to 11 wt.%”. It should be understood that when “about” precedes a term, the term should be interpreted as disclosing both the number of “about” in the term and the term without the “about”—for example, “about 10 wt.%” discloses both “9 wt.% to 11 wt.%” and “10 wt.%”.

[0023] As used in this disclosure, the phrase “and / or” will be understood to mean individually any one of the members or any combination of two or more of them – for example, “A, B and / or C” would mean “A, B, C, A and B, A and C, B and C, or a combination of A, B and C”.

[0024] As used herein, the term "polyolefin" refers to a homopolymer or copolymer having methylene bonds between monomer units, including, for example, binary copolymers, terpolymers, etc., which can be formed by any method known to those skilled in the art. Non-limiting examples include: low-density polyethylene (LDPE); high-density polyethylene (HDPE); ethylene α-olefin copolymers (EAO), preferably using 1-butene, 1-hexene, or 1-octene as comonomers, wherein the ethylene comonomer content is dominant and includes, for example, linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), metallocene-catalyzed linear low-density polyethylene (mLLDPE), plasmons, and elastomers; copolymers of ethylene and polar groups, such as vinyl acetate (VA), methyl acrylate (MA), or acrylic acid (AA), such as ethylene vinyl acetate copolymer (EVA), ethylene methyl acrylate copolymer (EMA), or ethylene acrylic acid copolymer (EAA); ionomers; functionalized polymers, including, for example, anhydride-modified polyolefins. Homopolymers of propylene and butene-1 containing polypropylene and polybutene-1, as well as copolymers of ethylene, propylene and butene-1 in different proportions, are useful.

[0025] As used throughout this application, the term "polypropylene" or "PP" refers to a plastic, homopolymer, or copolymer having at least one propylene monomer bond within the repeating backbone of the polymer. The propylene bond can be represented by the general formula: [CH2CH(CH3)]n. Such polypropylene can be an impact copolymer, a random copolymer, or a homopolymer, and can be syndiotactic or isotactic, or may or may not be transparent.

[0026] As used herein, a “laminate” is a membrane that can be constructed from an unlimited number of films and / or layers bonded together by any known method, such as, but not limited to, co-extrusion, coating, or lamination, to form a composite article.

[0027] As used herein, the term "layer" refers to a building block of a membrane, which is a structure or homogeneous blend of materials of a single material type. A layer can 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. A layer can be continuous with the membrane, or it can be discontinuous or patterned. A layer has a negligible thickness (z-direction) compared to its length and width (xy-direction), and is therefore defined as having two principal surfaces whose area is defined by the length and width of the layer. An outer layer is a layer that connects to another layer only at one of its principal surfaces. In other words, one principal surface of the outer layer is exposed. An inner layer is a layer that connects to another layer at both of its principal surfaces. In other words, the inner layer lies between two other layers. A layer may have sublayers.

[0028] As used throughout this application, the term "packaging" means any part or combination of parts used to completely or partially surround a product. Packaging can take many different forms. For example, the term "packaging" can comprise a bag, such as a stand-up pouch, that completely surrounds one or more products to be packaged; the term "packaging" can also comprise a film, sheet, etc., that partially surrounds one or more products to be packaged, and, when used in combination with another film, sheet, etc., completely surround one or more products.

[0029] As used herein, the term “adjacent” means that items (such as layers of a membrane) are close to each other with or without the use of an intermediate material (such as an adhesive). As used herein, the terms “directly adjacent” or “directly in contact” mean that items are in contact with each other without the use of an intermediate material.

[0030] As used herein, “retorch packaging film” or “retorch packaging” is a film or packaging made of film that can be filled with product, sealed, and remain airtight after exposure to a typical retort sterilization process. Typical retort sterilization is a batch process using temperatures of approximately 100°C to approximately 150°C, overpressures of up to approximately 70 psi (483 kPa), and durations ranging from minutes to hours. Common retort processes for products packaged in flexible films include steam or water immersion. Food or other products packaged in retort packaging film and retort sterilized can be stored under ambient conditions for extended periods (i.e., shelf-stable) while remaining sterile. Because the retort process is extremely demanding, highly specialized flexible packaging films have been designed to withstand it.

[0031] As used herein, "inorganic coating" refers to a layer comprising a metallic layer or an oxide coating. These layers act as a barrier. Inorganic coatings can be directly vacuum deposited (i.e., vacuum coating, vapor coating, vacuum metallization) onto the surface of a buffer layer. Alternatively, inorganic coatings can be deposited using wet chemical methods (e.g., solution coating). Therefore, inorganic coatings can include silicon oxide (SiOx) or aluminum oxide (AlOx).

[0032] As used in this article, “recyclable” refers to packaging that meets the collection, sorting, and recycling standards currently in place in a particular area.

[0033] As used herein, “recyclable” refers to packaging that is intentionally designed and manufactured to enable recycling in certain streams, such as, but not limited to, polypropylene-based recycling streams, based on material selection and global guidance.

[0034] As described herein, layers and / or films can be oriented layers and / or films. Orientation can be the result of uniaxial orientation (longitudinal or transverse) or biaxial orientation (longitudinal and transverse) stretching of the film, thereby increasing the longitudinal and / or transverse dimensions and subsequently reducing the thickness of the material. Biaxial orientation can be imparted to the film simultaneously or continuously. The film is stretched in either or both directions at a temperature just below the melting temperature of the polymer in the film. In this way, stretching “orients” the polymer chains, thereby altering the physical properties of the film. Simultaneously, stretching thins the film. The resulting oriented film is thinner and can exhibit significant changes in mechanical properties such as toughness, heat resistance, stiffness, tear strength, and barrier properties. Orientation is typically achieved through double-bubble or triple-bubble processes, through tenter frame processes, or through MDO processes using heated rollers. Typical blown film processes do impart some stretch to the film, but not enough to be considered oriented as described herein. Oriented films can be heat-set (i.e., annealed) after orientation, so that they are relatively dimensionally stable under elevated temperature conditions that may be experienced during the conversion (i.e., printing or lamination) of the retort film laminate or during the use of the laminate (i.e., heat sealing or retort sterilization).

[0035] As used herein, the terms "adhesive layer" or "bonding layer" refer to a layer or material placed on one or more layers or films to facilitate adhesion of said layer or film to another surface. For example, a bonding layer may be positioned between two layers of a multilayer film to hold the two layers in place relative to each other and prevent undesirable delamination. In another instance, an adhesive layer may be positioned between two films of a laminate to hold the two layers in place relative to each other and prevent undesirable delamination.

[0036] As used herein, “barrier,” “barrier film,” “barrier layer,” “barrier material,” or “barrier coating” refers to providing reduced permeability to gases such as oxygen (i.e., oxygen-containing barrier materials). Barrier materials can provide reduced permeability to moisture (i.e., moisture-containing barrier materials). Barrier properties can be provided by one or more of various barrier materials or blends thereof. Barrier layers can provide the specific barriers required to preserve a product within the packaging for an extended shelf life, which can be several months or even more than a year.

[0037] As used herein, the term "fold" or "folded" means a bend in itself, and a folded bend can have sharp or rounded edges. This bend shape can be described as a "V-shape," where the fold has a apex at the convergence of the curved surface. Thus, a V-shape can alternatively be described as typically having a narrow portion and a wide portion, where the apex is the narrowest point of the narrow portion. The term "dead fold" refers to a fold that cannot unfold spontaneously, such as a fold in a flexible foil material.

[0038] As used herein, the term "accordion pleat" refers to a folded portion of a flexible bag (e.g., a stand-up pouch) comprising at least three folds in a flexible film defining one or more central folds extending inward toward the interior of the product volume and two folds disposed on opposite sides of the central folds extending outward away from the central fold. Accordion pleats are also referred to differently as pleats, pleats, joints, connections, and gathers. Accordion pleats can be arranged to provide stability within a flexible bag, for example, by creating a surface on which the flexible bag rests. Accordion pleats can also be used to increase the volume of a flexible bag, for example, by creating a three-dimensional shape from the flexible material rather than a two-dimensional shape. A flexible bag can contain one or more accordion pleats disposed in any part of the flexible bag, such as the bottom side, top side, and / or one or more sides of the flexible bag.

[0039] As used herein, the term "outer layer" refers to one or more layers of the membrane on any of its main surfaces, i.e., layers not between two other layers of the membrane. The membrane has an outer surface that forms the exterior of a package using the membrane. When formed into a package, the outer surface of the membrane is exposed to the environment. The membrane has an inner surface that forms the interior of the package using the membrane. When formed into a package, the inner surface serves to form a seal and is exposed to the packaged product.

[0040] As used herein, a “sealing layer” is a layer comprising a composition configured to attach a film to the surface of another structure or itself, such as a package or packaging film, via fusion bonding or chemical bonding (e.g., adhesion). For example, a sealing layer may comprise a heat-sealable polymer composition. The sealing layer forms one of the two main surfaces of the film.

[0041] As used herein, the term "inner" describes a film, layer, or surface located in a position, such that it is in or near the packaged product, when the film is used in a packaging application. This layer is aligned with and positioned such that the product can access this layer when it is placed in the package.

[0042] There is a need to improve barrier properties associated with packaging structures that are folded and subjected to retort treatment. Furthermore, this need for improved barrier properties is particularly important for structures that can be considered recyclable or recyclable. The solution proposed in this paper addresses this problem by forming a laminate with a specific positioning of the barrier layer adjacent to a sealing layer that utilizes or requires folding to align with the internal space of the packaging assembly. Typically, when subjected to folding within a packaging assembly, the barrier layer of the laminate can be damaged due to compressive properties and stresses applied to the barrier material during folding. Therefore, by utilizing the positioning of the barrier layer with a more aligned internal packaging space during folding, this compressive stress is reduced and barrier integrity is maintained.

[0043] The recyclable laminate disclosed herein comprises a first layer, a second layer including a barrier layer, and a third layer, which will be detailed and discussed below. An embodiment of the recyclable laminate 10 is shown as follows: Figure 1 The laminate comprises a first layer 101, a second layer 102 adjacent to the first layer 101 and including a barrier layer 103, and a third layer 104 adjacent to the barrier layer 103. Therefore, the barrier layer 103 is located on the second layer 102, opposite the first layer 101 and the second side 111, serving as the inner layer between the second layer 102 and the third layer 104. Specifically, the first layer 101, the second layer 102, the barrier layer 103, and the third layer 104 are chosen relative to each other and to the internal packaging space 302. Figure 4 The position is designed to prevent loss of barrier properties when the recyclable laminate 10 is placed in the folded position in a package that requires folding within the packaging assembly. In addition to the second side 111, the first layer 101 includes a first side 110, wherein the second side 111 is opposite to the first side 110. The first side 110 is the first primary surface of the laminate 10, wherein the first layer 101 is the outer layer of the laminate 10. To ensure that the structure including the laminate 10 can be recycled and / or recycled in a dedicated recycling stream, the first layer 101, the second layer 102, and the third layer 104 all include the same type of polyolefin. In an embodiment, the polyolefin of the first layer 101, the second layer 102, and the third layer 104 is polypropylene. According to this embodiment, the laminate 10 can be considered as having a monomaterial structure including polypropylene, which is a recyclable structure for recycling in a polypropylene or polypropylene-based waste stream. The first layer 101 may include an optional printed marking layer (i.e., an ink layer, a graphic layer, a printing layer), which may be placed on either the second side 111 or the first side 110.

[0044] The printed marking layer can be applied using any printing process, such as, but not limited to, flexographic printing, rotary gravure printing, or digital printing. The printed marking layer can be made with compostable ink. The printed marking layer can be co-extended (100% coverage) with a recyclable laminate 10, or it can be patterned. The printed marking layer can include multiple colors layered on top of each other. If the printed marking layer is located on the first side 110, it can contain a clear topcoat with heat resistance and / or abrasion resistance. The printed marking layer can consist solely of a heat-resistant topcoat.

[0045] Now for reference Figure 2In alternative embodiments, the recyclable laminate 10 includes one or more adhesive layers 105. In some embodiments, the laminate 10 includes the adhesive layer 105 positioned between a first layer 101 and a second layer 102. In some embodiments, the adhesive layer 105 is located between a barrier layer 103 and a third layer 104. In some embodiments, a pair of adhesive layers 105 are located between the first layer 101 and the second layer 102 and between the barrier layer 103 and the third layer 104. The adhesive 105 may be solvent-based, solvent-free, or water-based. Commercially available adhesives may have an isocyanate-based reactive chemistry. Alternatively, the films and / or layers of the laminate 10 may be joined together by other means, such as extrusion lamination (using extruded polymers for bonding), co-extrusion, or thermal lamination.

[0046] When the laminate 10 is formed into the package 300, the first layer 101, which is the outer layer of the laminate 10, is positioned to have a fold 301 ( Figure 4 The outer surface of the packaging 300. Although it is the outer surface of the packaging 300, the first layer 101 is aligned with the innermost position of the fold, as shown. Figure 3 As shown, Figure 3 The relative positions of the multiple layers (101, 102, 103, 104) of laminate 10 in a package with accordion pleats are generally shown. In this position, the first layer 101 is under compressive stress together with the remaining layers of laminate 10. However, as shown in the figure ( Figure 3 When compared to other layers including the barrier layer 103, the first layer 101's positioning relative to the innermost part of the fold results in greater compressive stress. Therefore, due to the positioning of the barrier layer 103 relative to the fold, the barrier layer 103 is placed under tension compared to the compression experienced by the first layer 101.

[0047] The second layer 102 is a polyolefin of the same type as the first layer 101 and is located as an inner layer between the first layer 101 and the barrier layer 103. The second layer 102 is adjacent to the first layer 101 and includes the barrier layer 103 located on the second layer 102, opposite to the first layer 101.

[0048] Barrier layer 103 is a barrier coating typically used to provide barrier properties to laminate 10 by reducing the permeability of moisture and / or oxygen. Barrier layer 103 may be a metallized layer. Barrier layer 103 may be an inorganic deposit, such as, but not limited to, oxides of silicon (SiOx) or oxides of aluminum (AlOx), which are liquid-coated or deposited to form the barrier layer. This barrier layer 103 may be a vacuum-deposited barrier layer. Barrier layer 103 may be deposited by atmospheric atomic layer deposition.

[0049] The third layer 104 is located near the barrier layer 103 and is composed of the same polyolefin as the first layer 101 and the second layer 102. The third layer 104 is a sealing layer and is positioned as the outer layer of the laminate 10, containing a second main surface 140 aligned with the internal space 302 of the package 300. Relative to the fold 301 of the package 300, the third layer 104 is aligned at its apex with the outermost position of the fold, as shown below. Figure 3 As shown in the diagram. In this position, the third layer 104 is under the least amount of compressive stress relative to the fold compared to the other layers, and is considered to be under tension rather than compression along with the barrier layer 103.

[0050] In an embodiment of the multilayer laminate 10, the first layer 101 may include orientation, wherein the first layer 101 is an orientation layer. In an embodiment, the second layer 102 may include orientation, wherein the second layer 102 is an orientation layer. In another embodiment, both the first layer 101 and the second layer 102 may include orientation, wherein the first layer 101 and the second layer 102 are orientation layers.

[0051] To ensure sufficient barrier properties, in this embodiment, after the recyclable laminate 10 was boiled at 127°C for 50 minutes, the oxygen permeability in the folded area, measured according to ASTM F1927 under conditions of 1 atmosphere, 23°C, and 50% RH, was approximately less than 1.0 cm. 3 / m 2 / sky.

[0052] In one aspect that can be combined with any other aspect or embodiment, this disclosure provides the use of a recyclable laminate 10, wherein the layering composition and relative positions of the layers (101, 102, 103, 104) are specifically selected to optimize the integrity of the aforementioned barrier properties when the laminate 10 is used in packaging that requires folding.

[0053] Now for reference Figure 4 In another aspect, which can be combined with any other aspect or embodiment, packaging 300 is a recyclable stand-up pouch and / or stand-up bag formed from a recyclable laminate 10 having folded portions 301 or accordion pleats. As generally shown, the barrier layer is specifically positioned relative to the folded portions 301 near the sealing layer, the second main surface 140, and towards the packaging interior 302 to prevent loss of the film's barrier properties when the film is manipulated to form folded or accordion pleats during assembly of the stand-up pouch and exposure to retort conditions. Therefore, packaging 300 can be considered as a retort pouch composed of a retort packaging film.

[0054] Examples and data A series of four laminates were tested to confirm the improved barrier properties of retort pouches suitable for recycling. Specific membrane structures and layer properties are shown in Table 1. These are adhesive laminates of the structure from the outside to the inside of the packaging, read from left to right. For each barrier layer, a symbol (…) is used. () indicates the direction the barrier layer faces.

[0055] C1 is a recyclable laminate for foldable packaging, wherein a barrier is located near the exterior of the packaging. The laminate is structured as follows: a 25 μm oriented polypropylene outer film is adhesively laminated onto an inorganic barrier layer, which is formed on a 19 μm oriented polypropylene film adhesively laminated onto a 60 μm cast polypropylene sealing film. In this laminate, the barrier layer is located near the outer layer aligned with the exterior of the packaging.

[0056] A1 is an inventive structure that optimizes the placement of a barrier layer in a laminate for use in folded packaging. This structure is a recyclable laminate of a 25 µm oriented polypropylene outer film adhesively laminated to a 19 µm oriented polypropylene film, wherein an inorganic barrier layer is adhesively laminated to a 60 µm cast polypropylene sealing film opposite the outer film. In this laminate, the barrier layer is located near the sealing layer and aligned with the interior of the packaging.

[0057] C2 is a two-layer recyclable laminate for foldable packaging, wherein the barrier is located near the outside of the packaging, and the laminate is constructed as follows: a 19 µ oriented polypropylene film with an inorganic barrier layer is adhesively laminated onto a 60 µ cast polypropylene sealing film.

[0058] C3 is a conventional non-recyclable laminate for folded packaging, wherein the barrier is located near the outside of the packaging, the laminate being constructed as follows: a polyethylene terephthalate (PET) outer film with an inorganic barrier layer is adhesively laminated to a 15 µ oriented polyamide film, the 15 µ oriented polyamide film being adhesively laminated to a 60 µ cast polypropylene sealing film.

[0059] Table 1: Structure and composition of the laminates under test The structures in Table 1 underwent laboratory testing in the folded area before and after a 50-minute cooking period at 127°C to determine oxygen permeability under conditions of 1 atmosphere, 23°C, and 50% RH, according to ASTM F1927. To simulate the presence of folds in the packaging, the sheet of the above-mentioned laminate was folded in the machine direction, with the sealing layer facing outwards relative to the folded surface, as shown. Figure 3The general outline is shown below. To further ensure the consistency of the folds, dead creases were created by compression in a controlled roller gap to simulate the forces present during packaging. Barriers in the materials in Table 1 were then measured prior to cooking. The samples were then steam-cooked at 127°C for 50 minutes. To ensure the representative folds remained closed to simulate accordion pleats, paperclips were used to keep the folds closed to prevent the folds / simulated accordion pleats from opening during the cooking cycle. The laminates were tested in both the flat and folded positions before and after cooking. The test results are shown in Table 2 below.

[0060] Table 2: Oxygen Barrier Properties of Tested Laminates OTR cc / m 2 / d 23℃ 50% RH - Steam at 127℃ for 50 minutes OTR analysis and laboratory tests confirmed the importance of the barrier layer relative to the fold placement. Laminates C1 and A1 consist of the same materials and general structure, the difference being that the barrier layer is positioned on the second layer in A1. A1 has altered the position of the barrier layer relative to the fold. When comparing the test results for laminates C1 and A1, the data clearly show that this shift of the barrier closer to the seal improves oxygen permeability in the folded area. Since this folded area is typically the primary point of barrier loss, it can be confirmed that laminate A1 has improved barrier properties due to its positioning of the barrier layer closer to the inside of the package and towards the outside of the fold apex.

[0061] Examples of recyclable laminates and packaging Example A. A recyclable laminate for use in packaging requiring folded components to define internal packaging space, said recyclable laminate comprising: The first layer is a polyolefin; The second layer is adjacent to the first layer and is a polyolefin of the same type as the polyolefin in the first layer. The second layer includes a barrier layer located on the second layer and opposite to the first layer. A third layer, adjacent to the barrier layer, forms a sealing layer and is a polyolefin of the same type as the polyolefins of the first and second layers, and is configured to be positioned aligned with the internal packaging space. The barrier layer is positioned adjacent to the third layer and opposite to the first layer on the second layer to prevent loss of barrier properties when the laminate is placed in a folded position in the packaging assembly by placing the barrier layer closer to the interior space adjacent to the third layer.

[0062] Example B. A recyclable laminate according to Example A, wherein an adhesive is placed between the first layer and the second layer and between the barrier layer and the third layer.

[0063] Example C. A laminate with recyclability according to Example A or B, wherein the polyolefin of the first layer is polypropylene.

[0064] Example D. A laminate with recyclability according to any one of Examples A to C, wherein the barrier layer comprises an inorganic barrier coating.

[0065] Example E. A laminate with recyclability according to Example D, wherein the inorganic barrier coating comprises silicon oxide (SiOx) or aluminum oxide (AlOx).

[0066] Example F. A laminate with recyclability according to any of Examples A to E, wherein the first layer and the second layer are orientation layers.

[0067] Example G. A laminate according to any one of Examples A to F, having recyclability, wherein after being cooked at 127°C for 50 minutes, the oxygen permeability in the folded area is approximately less than 1.0 cm⁻¹, measured according to ASTM F1927 under conditions of 1 atmosphere, 23°C, and 50% RH. 3 / m 2 / sky.

[0068] Example H. A recyclable laminate having a layered composition selected to optimize the integrity of barrier properties in folded packaging, the recyclable laminate comprising: The first layer is an oriented polyolefin film having a first side, which is the outer side of the recyclable laminate and a first main surface, and is aligned with the outer side of the folded packaging. The second layer is adjacent to the first layer and is an oriented polyolefin film of the same type as the first layer; An inorganic barrier layer is located on the second layer and opposite to the first layer; The third layer, located near the inorganic barrier layer, forms a sealing layer and is a polyolefin of the same type as the first and second layers. The third layer is the outer layer of the laminate and has a second main surface aligned with the interior of the package to be folded. The third layer is positioned adjacent to the inorganic barrier layer to prevent loss of barrier properties by reducing tension on the barrier layer when the recyclable laminate is in a folded position during packaging assembly.

[0069] Example I. A laminate with recyclable properties according to Example H, wherein an adhesive is placed between the first layer and the second layer and between the barrier layer and the third layer.

[0070] Example J. A laminate with recyclable properties according to Example H or I, wherein the polyolefin of the first layer is polypropylene.

[0071] Example K. A laminate with recyclability according to any one of Examples H to J, wherein the inorganic barrier layer is a coating comprising silicon oxide (SiOx) or aluminum oxide (AlOx).

[0072] Example L. A laminate according to any one of Examples H to K, having recyclability, wherein after being cooked at 127°C for 50 minutes, the oxygen permeability in the folded area is approximately less than 1.0 cm⁻¹, measured according to ASTM F1927 under conditions of 1 atmosphere, 23°C, and 50% RH. 3 / m 2 / sky.

[0073] Example M. A self-standing package, the self-standing package having recyclability and having a folded portion or an accordion pleat portion, wherein at least the folded portion or the accordion pleat portion of the self-standing package includes: A membrane capable of being recycled, wherein the membrane capable of being recycled includes: The first layer comprises an oriented polyolefin and has a first main surface, which is the exterior of the self-standing package; The second layer comprises an oriented polyolefin of the same type as the first layer, and is located near the first layer and opposite the first main surface; An inorganic barrier layer is located on the second layer and opposite to the first layer; A sealing layer comprising a polyolefin of the same type as the first layer, the sealing layer being located near the inorganic barrier layer, the sealing layer having a second primary surface opposite the barrier layer, the second primary surface being the interior of the packaging; and The inorganic barrier layer is positioned adjacent to the sealing layer and relative to the interior of the packaging to prevent loss of barrier properties when the multilayer film is manipulated to form the folded portion required for forming the stand-up pouch.

[0074] Example N. The self-standing packaging according to Example M, wherein the multilayer film comprises an adhesive between the first layer and the second layer and between the barrier layer and the sealing layer.

[0075] Example O. The self-standing packaging according to Example M or N, wherein the multilayer film, the first layer of oriented polyolefin, is polypropylene.

[0076] Example P. A self-standing package according to any one of Examples M to O, wherein the inorganic barrier layer comprises silicon oxide (SiOx) or aluminum oxide (AlOx).

[0077] Example Q. A stand-up pouch according to any one of Examples M to P, wherein the multilayer film, after being boiled at 127°C for 50 minutes, exhibits an oxygen permeability of approximately less than 1.0 cm⁻¹ in the folded area, measured according to ASTM F1927 under conditions of 1 atmosphere, 23°C, and 50% RH. 3 / m 2 / sky.

Claims

1. A recyclable laminate for use in packaging requiring folded components to define internal packaging space, said recyclable laminate comprising: The first layer is a polyolefin; The second layer is adjacent to the first layer and is a polyolefin of the same type as the polyolefin in the first layer. The second layer includes a barrier layer located on the second layer and opposite to the first layer. A third layer, adjacent to the barrier layer, forms a sealing layer and is a polyolefin of the same type as the polyolefins of the first and second layers, and is configured to be positioned aligned with the internal packaging space. The barrier layer is positioned adjacent to the third layer and opposite to the first layer on the second layer to prevent loss of barrier properties when the laminate is placed in a folded position in the packaging assembly by placing the barrier layer closer to the interior space adjacent to the third layer.

2. The recyclable laminate of claim 1, wherein the adhesive is placed between the first layer and the second layer and between the barrier layer and the third layer.

3. The recyclable laminate according to claim 1 or 2, wherein the polyolefin of the first layer is polypropylene.

4. The laminate with recyclability according to any one of claims 1 to 3, wherein the barrier layer comprises an inorganic barrier coating.

5. The recyclable laminate according to claim 4, wherein the inorganic barrier coating comprises silicon oxide (SiOx) or aluminum oxide (AlOx).

6. A laminate with recyclability according to any one of claims 1 to 5, wherein the first layer and the second layer are orientation layers.

7. A laminate with recyclability according to any one of claims 1 to 6, wherein the laminate, after being boiled at 127°C for 50 minutes, has an oxygen permeability of less than 1.0 cm⁻¹ in the folded area, measured according to ASTM F1927 under conditions of 1 atmosphere, 23°C, and 50% RH. 3 / m 2 / sky.

8. A recyclable laminate having a layered composition selected to optimize the integrity of barrier properties in folded packaging, the recyclable laminate comprising: The first layer is an oriented polyolefin film having a first side, which is the outer side of the recyclable laminate and a first main surface, and is aligned with the outer side of the folded packaging. The second layer is adjacent to the first layer and is an oriented polyolefin film of the same type as the first layer; An inorganic barrier layer is located on the second layer and opposite to the first layer; The third layer, located near the inorganic barrier layer, forms a sealing layer and is a polyolefin of the same type as the first and second layers. The third layer is the outer layer of the laminate and has a second main surface aligned with the interior of the package to be folded. The third layer is positioned adjacent to the inorganic barrier layer to prevent loss of barrier properties by reducing tension on the barrier layer when the recyclable laminate is in a folded position during packaging assembly.

9. The recyclable laminate of claim 8, wherein the adhesive is placed between the first layer and the second layer and between the barrier layer and the third layer.

10. The recyclable laminate according to claim 8 or 9, wherein the polyolefin of the first layer is polypropylene.

11. The laminate with recyclability according to any one of claims 8 to 10, wherein the inorganic barrier layer is a coating comprising silicon oxide (SiOx) or aluminum oxide (AlOx).

12. A recyclable laminate according to any one of claims 8 to 11, wherein the laminate, after being boiled at 127°C for 50 minutes, has an oxygen permeability of less than 1.0 cm⁻¹ in the folded area, measured according to ASTM F1927 under conditions of 1 atmosphere, 23°C, and 50% RH. 3 / m 2 / sky.

13. A stand-up pouch, the stand-up pouch being recyclable and having a folded portion or an accordion pleat portion, wherein at least the folded portion or the accordion pleat portion of the stand-up pouch comprises: A membrane capable of being recycled, wherein the membrane capable of being recycled includes: The first layer comprises an oriented polyolefin and has a first main surface, which is the exterior of the self-standing package; The second layer comprises an oriented polyolefin of the same type as the first layer, and is located near the first layer and opposite the first main surface; An inorganic barrier layer is located on the second layer and opposite to the first layer; A sealing layer comprising a polyolefin of the same type as the first layer, the sealing layer being located near the inorganic barrier layer, the sealing layer having a second primary surface opposite the barrier layer, the second primary surface being the interior of the packaging; and The inorganic barrier layer is positioned adjacent to the sealing layer and relative to the interior of the packaging to prevent loss of barrier properties when the multilayer film is manipulated to form the folded portion required for forming the stand-up pouch.

14. The self-standing packaging of claim 13, wherein the multilayer film comprises an adhesive between the first layer and the second layer and between the barrier layer and the sealing layer.

15. The self-standing packaging according to claim 13 or 14, wherein the multilayer film, the first layer of oriented polyolefin, is polypropylene.

16. The self-standing packaging according to any one of claims 13 to 15, wherein the inorganic barrier layer comprises silicon oxide (SiOx) or aluminum oxide (AlOx).

17. The self-standing packaging according to any one of claims 13 to 16, wherein the multilayer film, after being boiled at 127°C for 50 minutes, exhibits an oxygen permeability of less than 1.0 cm⁻¹ in the folded area, measured according to ASTM F1927 under conditions of 1 atmosphere, 23°C, and 50% RH. 3 / m 2 / sky.

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