Lap-sealable polyethylene films and sealed packages

Abstract

A lap-sealable film comprises a non-oriented film, a heat-resistant lacquer (HRL), and a sealing layer. The non-oriented film comprises a first outer layer and a second outer layer. The first outer layer comprises a first polymeric blend having a low density polyethylene (LDPE) and an ethylene copolymer. The second outer layer comprises a non-oriented high density polyethylene (HDPE). The HRL is attached to the first outer layer and is coextensive with less than 100%, by area, of the exterior surface of the first outer layer. The sealing layer comprises an ethylene copolymer or a second polymeric blend having a LDPE and an ethylene copolymer. The ethylene copolymer has a density less than or equal to 0.92 g / cm3. The first polymeric blend has a seal initiation temperature less than or equal to 110°C. The lap-sealable film comprises a total composition having greater than or equal to 80% polyethylene.

Description

[0001] LAP-SEALABLE POLYETHYLENE FILMS AND SEALED PACKAGES

[0002] TECHNICAL FIELD

[0003]

[0001] This disclosure is related to lap-sealable multilayer film containing non-oriented layers and sealed packages including such lap-sealable films as described herein.

[0004] BACKGROUND

[0005]

[0002] There has been a shift in flexible packaging to move into more sustainable options. One of the main solutions is to make the entire structure from polyethylene-based materials (i.e., mono-polyethylene, or mono-PE materials), as these can be recycled with existing recycling technologies in most countries. The goal of increasing recyclability of polyethylene films becomes challenging when attempting to form packaging films with specific seal performance requirements, such as lap sealing.

[0006]

[0003] Traditionally, a packaging film having both heat resistance and sealability is achieved by forming a multilayer film. Multilayer films contain a plurality of layers specific for providing different enhanced sealing properties. Currently, lap sealing properties in non-barrier packages are obtained by using structures including a coextruded, biaxially oriented polypropylene (BOPP) external web that contains terpolymer PP on the outer layer to seal to an inner sealant layer with a similar composition, or using a BOPP that contains a significant amount of PE in the outer layer to seal to another PE-containing inner sealant layer. Only in the second case a relatively high level of lap seal strength (e.g., greater than approximately 10 N / 15 mm) could be reached. However, such BOPP / PE films can only be recycled in the mixed- PO recycling stream, rather than a mono-material PP or PE recycling stream, which may be more attractive to customers and recyclers. Packaging films with barrier and lap seal properties, such as BOPP / PETMet / PE, are by definition not recyclable due to the inclusion of polyethylene terephthalate (PET).

[0007]

[0004] Lap sealing is defined as the sealing of an inside layer of a film (or laminate) with an outer web (external layer) of the same film as opposed to fin seal, which is a sealing of the inside of the film to itself. Lap sealing offers some advantages with regards to, for example, reducing an amount (e.g., measured by a width) of material to form a package, seal integrity, and / or marketing reasons. For example, a customer may already own packaging lines designed to run non-recyclable lap sealable films (or laminates) with little to no capability for shifting the long seal configuration from lap seal to fin seal.

[0008]

[0005] Accordingly, without contesting the associated advantages of the state-of-the-art film structures, there is a need to overcome technical limitations in a lap-sealable mono-PE structure which can run on existing packing lines while increasing or maximizing the recyclability of the film structures.

[0009] SUMMARY

[0010]

[0006] Lap-sealable films can be used for packaging a wide variety of products including, but not restricted to food, cosmetics, lotions, lawn care products, cleaners / soaps, concentrates, industrial materials, pharmaceuticals, medical supplies, and medical devices.

[0011]

[0007] Embodiments of the disclosure advantageously provide lap-sealable films and sealed packages formed therefrom, or including, such lap-sealable films as described herein. The lap-sealable film is configured as a mono-polyethylene (mono-PE) structure having a total composition comprising greater than or equal to 80% PE. The lap-sealable film includes, at least, a non-oriented film configured with a sealable outer layer (i.e., first outer layer 110 described below) attached to (e.g., by coextrusion) a non-oriented HDPE-containing outer layer (i.e., second outer layer 120 described below), a sealing layer (as a part of a multilayer sealant film, for example) attached to an interior surface of the non-oriented film, and a heat-resistant lacquer (HRL) applied in register to an exterior surface of the non-oriented film. In some embodiments, the sealing layer includes an ethylene copolymer or a polymeric blend having a LDPE and an ethylene copolymer. As such, a package comprising the lap-sealable film may include a lap seal formed by heat sealing the sealable outer layer of the non-oriented film to the sealing layer. The package may additionally include a fin seal formed by heat sealing the sealing layer to itself. Advantageously, one or more components of the lap-sealable film provide enhanced heat stability, lap sealability, drop resistance, and optionally barrier properties for the lap-sealable film.

[0012]

[0008] In one or more embodiments, a lap-sealable film comprises at least a non-oriented film, a heat-resistant lacquer (HRL), and a sealing layer. The non-oriented film comprises a first outer layer and a second outer layer. The first outer layer comprises a first polymeric blend having a low density polyethylene (LDPE) and an ethylene copolymer. The second outer layer comprises a non-oriented high density polyethylene (HDPE). The HRL is attached to an exterior surface of the first outer layer and is coextensive with less than 100%, by area, of the exterior surface of the first outer layer. The sealing layer comprises an ethylene copolymer or a second polymeric blend having a LDPE and an ethylene copolymer. The ethylene copolymer has a density less than or equal to 0.92 g / cm3. The first polymeric blend has a seal initiation temperature less than or equal to 110°C when tested in the lap seal configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2. The lap-sealable film comprises a total composition having greater than or equal to 80% polyethylene.

[0013]

[0009] In some embodiments, one or both of the first polymeric blend and the second polymeric blend further comprise one or both of a linear low density polyethylene (LLDPE) and a very low density polyethylene (VLDPE).

[0014]

[0010] In some embodiments, the second polymeric blend has a seal initiation temperature less than or equal to 1 10°C when tested in the fin seal or the lap seal configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2.

[0015]

[0011] In some embodiments, the ethylene copolymer comprises a terpolymer. In some embodiments, the ethylene copolymer comprises one or more of a polyethylene plastomer, a polyolefin plastomer, or an ethylene-a-olefin copolymer.

[0016]

[0012] In some embodiments, the second outer layer comprises greater than or equal to 80% of the second HDPE, by weight.

[0017]

[0013] In some embodiments, the first outer layer has a thickness in a range of from 2 micron to 10 micron. In some embodiments, the second outer layer has a thickness in a range of from 2 micron to 40 micron. In some embodiments, the non-oriented film has a total thickness in a range of from 4 micron to 60 micron. In some embodiments, the sealing layer has a thickness in a range of 2 micron to 40 micron.

[0018]

[0014] In some embodiments, the non-oriented film has a lap seal strength greater than or equal to about 8 N / 15 mm when tested according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2.

[0019]

[0015] In some embodiments, the lap-sealable film further comprises an adhesive layer between the second outer layer and the sealing layer. In some embodiments, the adhesive layer comprises polyurethane. In some embodiments, the lap-sealable film further comprises a printed layer between the second outer layer and the sealing layer.

[0020]

[0016] In some embodiments, a package comprising the lap-sealable film further comprises at least one lap seal bonding the first outer layer of the non-oriented film to the sealing layer. In some embodiments, a package comprising the lap-sealable film further comprises at least one fin seal bonding the sealing layer to itself.

[0021]

[0017] In some embodiments, a package formed from the lap-sealable film comprises the non-oriented film as described herein, the sealing layer as described herein, at least one lap seal bonding the first outer layer of the non-oriented film to the sealing layer, and at least one fin seal bonding the sealing layer to itself.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023]

[0018] 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:

[0024]

[0019] Figure 1 illustrates a schematic cross-sectional view of an embodiment of a nonoriented film, according to embodiments of the present disclosure;

[0025]

[0020] Figure 2 illustrates a schematic cross-sectional view of an embodiment of a lap- sealable film, according to embodiments of the present disclosure;

[0026]

[0021] Figure 3 illustrates a schematic perspective view of an embodiment of a sealed package including at least a lap seal, according to embodiments of the present disclosure;

[0022] Figure 4A illustrates a schematic cross-sectional view of an embodiment of a portion of the sealed package along line A-A’ of Figure 3, according to embodiments of the present disclosure;

[0027]

[0023] Figure 4B illustrates a schematic cross-sectional view of an embodiment of a portion of the sealed package along line B-B’ of Figure 3, according to embodiments of the present disclosure;

[0028]

[0024] Figure 5 is a graph of seal length against temperature, illustrating results of hot tack analysis of different types of multilayer sealant films, according to embodiments of the present disclosure;

[0029]

[0025] Figure 6 is a graph of seal strength against temperature, illustrating results of fin seal strength analysis of different types of multilayer sealant films, according to embodiments of the present disclosure; and

[0030]

[0026] Figure 7 is a graph of seal strength against temperature, illustrating results of lap seal strength analysis of different types of multilayer sealant films, according to embodiments of the present disclosure.

[0031]

[0027] The Figures show some but not all embodiments. The elements depicted in the Figures are illustrative and not necessarily to scale, and the same (or similar) reference numbers denote the same (or similar) features throughout the Figures. It will be understood, however, that the use of a number to refer to a component in a given Figure is not intended to limit the component in another Figure labeled with the same number.

[0032] DETAILED DESCRIPTION

[0033]

[0028] The flexible packaging industry is moving toward more sustainable options, including streamlining of the materials used into narrow categories. For example, one option is to design packaging structures (or packages) with high polyolefin content (e.g., high polyethylene, or PE, content) in order to categorize the films as recyclable. While reduction (or elimination) of non-olefinic polymers has generally resulted in enhanced recyclability of packaging structures, it has presented challenges to other aspects of the performance of the packaging structures for which improvements are desired.

[0029] In one example, obtaining robust lap seal properties, such as a seal strength greater than approximately 8 N / 15 mm, can be challenging with packaging films that include mono-PE (i.e., containing, or substantially containing, only PE) structures. This may be attributed, at least in part, to properties of external web (or external layers) of the lap seal, which typically includes high density PE (HDPE)-rich machine direction oriented PE (MDOPE) or biaxially oriented PE (DOPE). While such oriented PE films are usually designed to provide as much heat resistance as possible to avoid melting or sticking to sealing jaws, it may become difficult to seal packaging films including such oriented PE films at relatively low temperatures before the packaging films become distorted upon heating.

[0034]

[0030] In another example, drop resistance or resistance to tear, breaks, and / or holes after, for example, several drops of a filled Quadro packaging structure from a height of 1 m is a common embedded functionality requested by e.g., retailers and end consumers to ensure integrity of such packaging structure. A Quadro packaging structure is also known as a four-corner-sealed type of a gusseted stand-up pouch that incorporates a lap seal in one of the corner seals. The limited seal strength of a lap seal configuration typically presents a structural weak point, especially when considering heavy-duty packaging, and therefore may negatively impact the drop resistance of the packaging structure.

[0035]

[0031] Embodiments of the disclosure advantageously provide lap-sealable films including non-oriented (mono-PE) films and sealed packages formed from, or including, such lap-sealable films. Incorporation of the materials as described herein into the lap-sealable films can reduce the negative effects of utilizing a more recyclable set of polymer materials. As a result, the non-oriented films described herein are more easily recyclable due to the high polyethylene content. The lap-sealable films made from the non-oriented films described herein have at least improved heat stability, lap seal strength, and drop resistance.

[0036]

[0032] For example, in some embodiments, the incorporation of a polymeric blend containing a low-density (LDPE) and an ethylene copolymer (e.g., a plastomer) in a sealable layer of the non-oriented film helps improve the heat sealability and seal strength when forming a lap seal between the non-oriented film and an inner sealing layer of the lap-sealable film. In some embodiments, the sealable layer of the nonoriented film is coextruded with a layer of non-oriented high density PE (HDPE). In some embodiments, the non-orientation of the HDPE is configured to not only provide a sufficient level of heat resistance and stiffness for maintaining integrity of the lap- sealable film during the sealing process, but also to improve the sealability of the nonoriented film when coextruded with the sealable layer. In some embodiments, the incorporation of a heat-resistant lacquer (HRL) applied in register over the nonoriented film provides additional protection of the lap-sealable film against heat distortion and adhesion (e.g., stickiness) to a sealing apparatus during the sealing process.

[0037]

[0033] As used herein, the term “film” is a monolayer or multilayer web that has an insignificant z-direction dimension (thickness) as compared to the x- and y-direction dimensions (length and width). Films are generally regarded as having two major surfaces, opposite each other, expanding in the length and width directions. The innermost surface of the film, which is connected to another layer or film such that the innermost surface is not exposed may be referred to an "inner surface" or "interior surface." The surface of the film that is not connected to another layer or film is an exposed surface (e.g., an outer surface or an exterior surface) of the film and may be referred to as an “exterior surface.” Films may be built from an unlimited number of films or layers; the films or layers being bonded together to form a multilayer film.

[0038]

[0034] The term “layer,” as used herein, refers to a building block of films that is a structure of a single polymer or a homogeneous blend of materials. A layer may contain other non-polymeric materials and may have additives. Layers may be continuous or discontinuous (e.g., patterned) with the length and width of the film. In a monolayer film, “film,” “sheet,” and “layer” are synonymous. Embodiments of the non-oriented films and the lap-sealable films include as many layers as desired and, preferably, at least two layers.

[0039]

[0035] The term “multilayer,” as used herein, refers to a single film structure, which may have a plurality of layers, generally in the form of a sheet or web that can be made from a polymeric material or a non-polymeric material bonded together by any conventional means known in the art, (i.e., coextrusion, lamination, coating, or a combination thereof).

[0040]

[0036] As used herein, layers or films that are “in direct contact with” or “are directly adjacent to” each other have no intervening material disposed between them.

[0041]

[0037] As used herein, the term “printed indicia layer” or “printed ink layer” refers to a layer or series of sub-layers that have been printed onto a film. The layer or sub-layers may include pigment containing materials (e.g., colored ink), protective layers (e.g., overlacquer), and ink receptive primers. Over-lacquer may protect a printed pigment layer and may improve the appearance of surface the film. Each of the printed indicia layer(s) may be independently continuous with the other layers of the film or independently discontinuous (e.g., patterned). Specifically, a printed indicia layer may include one or more continuous sub-layers of white pigmented print and one or more patterned sub-layers including other colors, thus producing the visible graphics for the packaging film.

[0042]

[0038] As used herein, the term “barrier layer” refers to a layer that significantly reduces the transmission of one or more molecular species through the layer. A barrier layer may be a surface layer or an inner layer of a film. A barrier layer may limit or reduce the permeation of migratory species such as moisture, oxygen, and / or other gasses. Barrier layers are typically comprised of metals or polymers that are referred to as “barrier materials.” Barrier materials suitable for films and components include, but are not limited to, ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVOH), polyvinylidene chloride (PVDC), HDPE, cyclic olefin copolymers (COC), polyamides (PA), polyacrylates, metals, metal oxides (e.g., silicon oxide (SiOx), aluminum oxide (AIOx)), the like, or combinations thereof. Barrier layers may comprise blends of materials. The film may contain multiple barrier layers, that is, a second barrier layer, a third barrier layer, and so on. The film may further include additional layers to provide bulk or adhesion, among other things.

[0043]

[0039] As used herein, the terms "polyethylene" or “PE” refers to, unless indicated otherwise, ethylene homopolymers as well as copolymers of ethylene with at least one alpha-olefin. The term will be used without regard to the presence or absence of substituent branch groups. Polyethylene includes, for example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), very low (or ultra-low) density polyethylene (VLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-alpha-olefin copolymer, or various combinations or blends thereof.

[0044]

[0040] As used herein, the terms “polyethylene-based” or “polyethylene-containing” refers to an article (e.g., a package, a film, a layer, etc.) that comprises high levels of polyethylene polymers. In some cases, a polyethylene-based article has at least 50% polyethylene polymers, by weight. In some cases, a polyethylene-based article may have at least 60%, at least 70%, at least 80%, at least 90% or at least 95% polyethylene polymers, by weight. In some cases, a polyethylene-based article consists of polyethylene polymers. In some embodiments, the lap-sealable film described herein includes at least 80% polyethylene and is referred to as a monopolyethylene (mono-PE) structure.

[0045]

[0041] As used herein, the term "ethylene copolymer" refers to, unless indicated otherwise, a polyethylene having a density less than or equal to 0.92 g / cm3. Examples of the ethylene copolymer include polyethylene plastomers, polyolefin plastomers, linear-alpha-olefin copolymers, the like, or combinations or blends thereof. Examples of linear-alpha-olefin copolymers include, but are not limited, to metallocene linear low density polyethylene (mLLDPE) and copolymers of 1 -butene, 1 -hexene, 1 -octene, the like, or combinations thereof.

[0046]

[0042] As used herein, the terms “high density polyethylene” or “HDPE” refer to both (a) homopolymers of ethylene that have densities from about 0.960 g / cm3to about 0.970 g / cm3, and (b) copolymers of ethylene and an alpha-olefin (usually 1 -butene or 1 - hexene) that have densities from about 0.940 g / cm3to about 0.958 g / cm3. HDPE includes polymers made with Ziegler or Phillips type catalysts and polymers made with single-site metallocene catalysts. HDPE also includes high molecular weight polyethylene. As used herein, the terms "medium density polyethylene" or "MDPE" refer to a polyethylene having a density in a range of from 0.926 g / cm3to 0.945 g / cm3.

[0047]

[0043] Furthermore, as described herein, the term “oriented” indicates that the film has been heated to a temperature lower than the melting point of the material and stretched at least about two times (i.e., the dimension of the film is increased at least about two times the original dimension). Correspondingly, the terms “non-oriented” or “unoriented” refer to a monolayer or multilayer film, sheet or web that is substantially free of post-extrusion orientation. As described herein, the PE-containing layers (e.g., the first outer layer 110 and the second outer layer 120 described below) of the nonoriented film do not undergo stretching during their formation process to impart any monoaxial or biaxial orientation in the polymeric chains of the layers. In some embodiments of the present disclosure, a blown film process is utilized to form the PE-containing layers. Although the blown film process does impart some stretching of the layers, such stretching is not enough to result in an oriented polymer film. Accordingly, the thus-formed PE-containing layers are considered “non-oriented” or “unoriented.”

[0048]

[0044] As used herein, the terms “sealable layer” or “sealing layer” refer to a layer of a film, sheet, etc., involved in the sealing of the film, sheet, etc., to itself and / or to another layer of the same or another film, sheet, etc. As used herein, the terms “heat seal,” “heat sealed,” “heat sealing,” “heat sealable,” and the like, refer to both a film layer which is heat sealable to itself or other film layer, and the formation of a bond between two polymer surfaces by conventional indirect heating means. It will be appreciated that conventional indirect heating generates sufficient heat on at least one film contact surface for conduction to the contiguous film contact surface such that the formation of a bond interface therebetween is achieved without loss of the film integrity.

[0049]

[0045] Heat sealing is a well-known and commonly used process for creating packages and is familiar to those skilled in the art. Without intending to be bound by theory, during heat sealing, a sealable material in the non-oriented film softens due to the application of heat, allowing formation of a heat seal bond between the non-oriented film and another layer, such as a sealing layer attached to an interior surface of the non-oriented film in the case for a lap seal. Since heat must be driven through the entire non-oriented film to raise the temperature of the sealable material, it is advantageous if the heat sealable material softens and seals at a relatively low temperature. A lower seal initiation temperature (SIT) enables faster packaging line speeds. For example, some embodiments of the non-oriented film (e.g., the lap- sealable film comprising the non-oriented film) may include a heat sealable material that exhibits a SIT of less than or equal to approximately 110°C, less than or equal to approximately 100°C, or less than or equal to approximately 90°C.

[0050]

[0046] Suitable heat sealable materials having a SIT in the aforementioned ranges may include, but are not limited to, acrylate copolymers, polyesters, PE, PP, or hot melts (wax based). In some embodiments, the heat sealable material of the non-oriented film comprises PE. In some embodiments, the heat sealable material comprises more PE than any other polymer, such that the heat sealable material is considered to have a mono-PE structure. The SIT and heat seal strength provided by the heat sealing can be measured according to ASTM F88 at a sealing pressure of approximately 300 N / 15 cm2for a sealing time of approximately 0.5 seconds.

[0051]

[0047] In some embodiments, the lap-sealable film described herein is formed by attaching (using an adhesive layer, for example) a sealing layer (included in a multilayer sealant film, for example) to an interior surface of the non-oriented film, and attaching (by surface printing, for example) a HRL in register to an exterior surface of the non-oriented film. In some embodiments, the sealing layer includes a sealable material similar in composition to or the same as that included in the non-oriented film. In some embodiments, the non-oriented film forms an external web of the lap-sealable film. Additional layers may be added to the lap-sealable film, including, but not limited to, printed indicia layers, adhesive layers, and / or barrier layers. The lap-sealable films including the non-oriented film as described herein can be advantageously used to form hermetically sealed packages that include at least lap seals. Furthermore, such lap-sealable films are also configured to form packages that include other types of seals, such as fin seals.

[0052]

[0048] An embodiment of a non-oriented film structure is illustrated in Figure 1. Without being limited to any particular embodiment, any suitable method, including the methods described herein, may be used to form the embodiment of the non-oriented film structure illustrated in Figure 1.

[0053]

[0049] Figure 1 illustrates a schematic cross-sectional view of an embodiment of a nonoriented film 100. The non-oriented film 100 has a total composition comprising greater than or equal to 80% polyethylene, including greater than or equal to 85% polyethylene, greater than or equal to 90% polyethylene, or greater than or equal to 95% polyethylene. The non-oriented film 100 has an exterior surface 102 and an interior surface 104.

[0054]

[0050] The non-oriented film 100 of Figure 1 comprises a first outer layer 110 and a second outer layer 120 attached to the first outer layer 110. As depicted herein, the second outer layer 120 provides (or includes) the interior surface 104 of the nonoriented film 100 and the first outer layer 110 provides (or includes) the exterior surface 102 of the non-oriented film 100. Accordingly, as the non-oriented film 100 is configured to form a lap seal, the first outer layer 110 is considered a sealable layer to be bonded to a sealing layer (e.g., sealing layer 142 described below) attached to the second outer layer 120, and the second outer layer 120 is considered a treated, non-sealable layer. In some embodiments, the non-oriented film 100 is configured as an external web of a lap-sealable film (e.g., lap-sealable film 200 described below).

[0055]

[0051] The first outer layer 110 is formed from a first polymeric blend that includes a LDPE and an ethylene copolymer. In some embodiments, the first polymeric blend further includes a LLDPE, a VLDPE, or a combination (or blend) thereof. In some embodiments, the ethylene copolymer has a density less than or equal to 0.92 g / cm3. In some embodiments, the ethylene copolymer includes a plastomer, a linear-alpha- olefin copolymer, the like, or combinations (or blends) thereof. In some embodiments, the plastomer includes a PE plastomer, a polyolefin plastomer, or a combination thereof. In some embodiments, the ethylene copolymer includes a terpolymer synthesized from three distinct monomers. In some embodiments, the first outer layer 110 is free, or substantially free, of any MDPE or HDPE.

[0056]

[0052] The first polymeric blend in the first outer layer 110 is configured to be heat sealable with a sealing layer (e.g., the sealing layer 142 of a multilayer sealant film 140 described below) at a relatively low SIT. In some embodiments, the first polymeric blend has a SIT of less than or equal to approximately 1 10°C, less than or equal to approximately 100°C, or less than or equal to approximately 90°C, which can be measured in the lap seal configuration according to ASTM F88. In one such example, the SIT and the heat seal strength are measured at a sealing pressure of approximately 300 N / 15 cm2for a sealing time of approximately 0.5 seconds.

[0053] The second outer layer 120 is formed from a non-oriented HDPE. In some embodiments, the non-oriented HDPE is in a form of an HDPE-rich blown film. In some embodiments, the non-oriented HDPE is free, or substantially free, of any postprocessing orientation (e.g., machine-direction or cross-direction). For example, the non-oriented HDPE is free, or substantially free of, any HDPE-rich MDOPE or HDPE- rich DOPE. In some embodiments, the second outer layer 120 includes greater than or equal to 80% of the non-oriented HDPE, including greater than or equal to 99% of the non-oriented HDPE, or 100% of the non-oriented HDPE, by weight.

[0057]

[0054] In some embodiments, the first outer layer 110 and the second outer layer 120 are formed by coextrusion. The first outer layer 110 is formed to a thickness in a range of from approximately 2 micron (pm) to approximately 10 micron. The second outer layer 120 is formed to a thickness in a range of from approximately 2 micron to approximately 40 micron, including in the range of from approximately 5 micron to approximately 30 micron, or in the range of from approximately 5 micron to approximately 25 micron. In some embodiments, the non-oriented film 100 is formed to a thickness in a range of from approximately 4 micron to approximately 60 micron. In some examples, the non-oriented film 100 is formed to a thickness of approximately 25 micron, 30 micron, or 35 micron.

[0058]

[0055] Figure 2 illustrates a schematic cross-sectional view of an embodiment of a lap- sealable film 200. The lap-sealable film 200 includes at least the non-oriented film 100, a sealant film 140 attached (or connected) to the interior surface 104 (i.e., the second outer layer 120) of the non-oriented film 100, where the sealant film 140 includes a sealing layer (e.g., an outer sealing layer) 142, and HRL 160 attached to the exterior surface 102 (i.e., the first outer layer 110) of the non-oriented film 100. In this regard, the sealant film 140 is attached to the non-oriented film 100 at the interior surface 104, which is protected by the HRL 160 at the exterior surface 102. The sealing layer 142 is disposed along an exterior surface 106 of the sealant film 140, where the exterior surface 106 is opposite an interior surface 108 of the sealant film 140 to which the non-oriented film 100 is attached. In some embodiments, the sealant film 140 is a multilayer sealant film.

[0056] The sealing layer 142 is configured to be heat sealable with the first outer layer 110 of the non-oriented film 100. As such, in some embodiments, the sealing layer 142 includes an ethylene copolymer described herein. In some embodiments, the ethylene copolymer in the sealing layer 142 is similar to or substantially the same as the ethylene copolymer in the first outer layer 110 in composition. In some embodiments, the ethylene copolymer in the sealing layer 142 is different from that in the first outer layer 110 in composition.

[0059]

[0057] In alternative embodiments, the sealing layer 142 includes a second polymeric blend having a LDPE and an ethylene copolymer described herein. In some embodiments, the second polymeric blend has a SIT less than or equal to approximately 1 10 °C, including less than or equal to approximately 100 °C, or less than or equal to approximately 90 °C. In some embodiments, the second polymeric blend further includes a LLDPE, a VLDPE, or a combination (or blend) thereof. The ethylene copolymer included in the second polymeric blend is similar to or substantially the same as that in the first outer layer 110 in composition. In some embodiments, the ethylene copolymer in the second polymeric blend is different from that in the first outer layer 110 in composition.

[0060]

[0058] In some embodiments, the sealant film 140 is formed by coextruding various components of the sealant film 140 to form a multilayer structure. In some embodiments, the sealant film 140 is formed to a thickness in a range of from approximately 30 micron to approximately 150 micron. In some embodiments, the sealing layer 142 is formed to a thickness in a range of from approximately 2 micron to approximately 40 micron. In an example embodiment, the sealant film 140 is formed to a thickness of approximately 80 micron.

[0061]

[0059] In some embodiments, the sealant film 140 is attached to the second outer layer 120 of the non-oriented film 100 by lamination, such as extrusion or adhesive lamination. If lamination is used, an adhesive layer 130 is applied between the sealant film 140 and the second outer layer 120. The adhesive layer 130 may include, but is not limited to, a two-component curing adhesive applied by coating (e.g., gravure) or a polymeric adhesive applied by extrusion. In some embodiments, the adhesive layer 130 includes a solvent-less adhesive. For example, the adhesive layer 130 may include a polyurethane-based solvent-free adhesive.

[0062]

[0060] Additional layers may be included in the lap-sealable film 200, including, but not limited to, printed indicia layers, adhesive layers, and / or barrier layers. For example, the lap-sealable film 200 may further include a printed indicia layer 150. In some embodiments, the printed indicia layer 150 is formed by a reverse printing process. In some embodiments, the printed indicia layer 150 is omitted from the lap-sealable film 200.

[0063]

[0061] In some embodiments, the lap-sealable film 200 further comprises a barrier layer (not shown in the illustrated embodiment) between the first outer layer 110 and the sealant film 140 (i.e., the sealing layer 142). In some embodiments, the unillustrated barrier layer comprises one or more of EVOH or PA, coextruded in the non-oriented film 100. In some embodiments, the unillustrated barrier layer comprises an extruded polymer layer (such as EVOH and / or PA) adjacent to the sealing layer 142 and not within the non-oriented film 100. In some embodiments, the unillustrated barrier layer additionally or alternatively comprises a vacuum-deposited material, such as metal oxide (e.g., silicon oxide (SiOx), aluminum oxide (AIOx)), and / or metal (e.g., aluminum), located on the interior surface 104 of the non-oriented film 100. In some embodiments, the unillustrated barrier layer additionally or alternatively comprises a coated material, such as PVOH and / or polyacrylate, located on the interior surface 104 of the non-oriented film 100. In some embodiments, the unillustrated barrier layer additionally or alternatively comprises COC.

[0064]

[0062] In some embodiments, the HRL 160 includes one or more of polyurethane, nitrocellulose, acrylate, polyvinyl butyral (PVB), or copolymers thereof. The HRL 160 may include other polymers which are cross linkable using ultraviolet (UV) light and electron beam (EB) curing processes. The HRL 160 may be pigmented or unpigmented. The HRL 160 may provide a glossy or matte finish to the lap-sealable film 200. In some examples, the HRL 160 may include one or more of SYSTS200, SYSTS457, and SYSTS410 (commercially available from Sun Chemical Ltd, UK). In some examples, the HRL 160 may include one or more of BG 2K 100, H HARDENER 10-600014-4.1570, and H HARDENER 10-600015-1.1620 (commercially available from Siegwerk Belgium N.V.). In some other examples, the HRL 160 may include a two-component system such as a blend of Herberts-GL 3335 and hardener GLI106 (commercially available from Bostik SA).

[0065]

[0063] The HRL 160 is applied on the first outer layer 110 (i.e., at the exterior surface 102) of the non-oriented film 100 in register, such that the HRL 160 is partially coextensive with the underlying first outer layer 110. For example, as depicted in Figure 2, the first outer layer 110 includes a first portion 110A and a second portion 11 OB. The HRL 160 is attached to the first portion 110A but not the second portion 110B, such that the second portion 110B is exposed for subsequent heat sealing with a portion of the sealing layer 142 to form a lap seal.

[0066]

[0064] In some embodiments, an area of the HRL 160 corresponds to a critical area of the lap-sealable film 200 (i.e., the non-oriented film 100) to be placed in direct contact with portions (e.g., sealing jaws) of a sealing apparatus during a heat sealing process. In this regard, the partial coverage of the HRL 160 not only allows a lap seal to be formed between the first outer layer 110 and the sealant film 140 but also provides protection for the non-oriented film 100 against potential heat damage, which may lead to inadvertent melting or adhesion to the sealing apparatus. In some embodiments, the HRL 160 is coextensive with less than 100% of the first outer layer 110, including less than 95% of the first outer layer 110, less than 90% of the first outer layer 110, or less than 85% of the first outer layer 110. Specific coverage of the HRL 160 may vary based on intended applications of the lap-sealable film 200. In some embodiments, the HRL 160 is applied to the first outer layer 110 by surface printing.

[0067]

[0065] In some package embodiments, the lap-sealable film 200 containing the nonoriented film 100 may be used to form flexible film packages such as stand-up pouches, pillow pouches, sachets, brick bags, flow wrap bags, stick packs, pillow packs, and the like. Advantageously, the lap-sealable film 200 is used for package styles that include a lap seal configuration, i.e., an outside-to-inside configuration. Additionally, the sealing layer 142 can be heat sealed with itself, allowing the lap- sealable film 200 to be applied in package styles that include a fin seal configuration, i.e., an inside-to-inside configuration.

[0066] Figure 3 illustrates a schematic perspective view of an embodiment of a hermetically sealed package (or a sealed package component) 300 formed from an embodiment of the lap-sealable film 200 of Figure 2. The lap-sealable film 200 has been formed by a vertical form fill and seal (VFFS) packaging line, for example, sealing the lap-sealable film 200 around a product (not shown). The sealed package 300 formed may be configured to contain a variety of food or non-food product. Example food products include, but are not limited to, confectionary, snack bars, snack crisps, dry powders, liquids, and / or pastes. The sealed package 300 may be well suited to contain products that include a moisture content of greater than 30%, such as 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any other moisture contents therebetween. The non-oriented film 100 and the corresponding lap-sealable film 200 disclosed herein can be advantageously used to package products, such as the sealed package 300, that may be sensitive to moisture gain or loss, providing significant barrier to moisture transmission.

[0068]

[0067] As depicted in Figure 3, the lap-sealable film 200 is oriented such that the HRL 160 (i.e., the exterior surface 102 of the non-oriented film 100 corresponding to the first outer layer 110) is on the exterior (or outside) of the sealed package 300, visible by a consumer. Likewise, the interior surface 104 of the non-oriented film 100 (i.e., the side of the non-oriented film 100 corresponding to the second outer layer 120 and to which the sealant film 140 is attached) is oriented towards the interior (or inside) of the sealed package 300 (not depicted in Figure 3). Accordingly, as further depicted in Figure 4A, which illustrates a schematic cross-sectional view an embodiment of the sealed package 300 along line A-A’ of Figure 3, the sealant film 140 is exposed to the packaged product.

[0069]

[0068] As depicted in both Figure 3 and Figure 4A, the sealed package 300 includes a lap seal 312 that extends along a length of the sealed package 300 and lays flat on the sealed package 300. Referring to Figure 3 and Figure 4B, the sealed package 300 further includes two fin (or end) seals 314 extending substantially perpendicular to the lap seal 312. In some embodiments, the fin seals 314 are formed by heat sealing together portions of the sealant film 140. The sealant film 140 is attached to, by heat sealing, the second outer layer 120 (not depicted separately) of the non-oriented film 100 along a length of the lap seal 312. Figure 4A further depicts the second portion 11 OB over which the HRL 160 is not applied to allow the lap seal 312 to be formed between the first outer layer 110 of the non-oriented film 100 and the sealant film 140 (e.g., the sealing layer 142).

[0070]

[0069] The lap-sealable film 200 formed from the non-oriented film 100 described herein may be recycled after their primary use is completed. The term “suitable for recycling,” as used herein, is meant to indicate that the film can be converted into a new, useful item by means of reprocessing in a recycle stream (e.g., recycling streams based on the polymer or single polymer). Reprocessing may entail washing, separating, melting, and forming, among many other steps. Typically, when flexible polymeric packaging is recycled by reprocessing, the material is mechanically chopped into small pieces (e.g., granulated, flaked, etc.), melted, mixed, and reformed into the new product. If multiple incompatible materials are present in the packaging, interactions occur during reprocessing that can cause gels, brittle material, poor appearance, and generally unusable or poor-quality products. Using the term “recyclable” indicates that these drawbacks generally are not present. Qualification as a recyclable material is not regulated by any specific agencies but can be obtained from groups such as the Association of Plastic Recyclers (APR) and How2Recycle™.

[0071]

[0070] Various embodiments of the lap-sealable film 200 disclosed herein are configured to be recyclable. The recyclable lap-sealable film 200 includes greater than 80% of a single polymer, such as PE. In this regard, the lap-sealable film 200 is considered as a mono-PE film. As used in this application, the term “single polymer” refers to a blend of different polymers in the same category of a particular polymer type. In the embodiments of the present disclosure, the lap-sealable film 200 includes greater than or equal to 80 % of a blend of ethylene-based polymers. For example, the first outer layer 110 of the non-oriented film 100 includes the first polymeric blend having a LDPE and an ethylene copolymer, the second outer layer 120 of the non-oriented film 100 includes a non-oriented HDPE, and the sealing layer 142 includes an ethylene copolymer or the second polymeric blend described herein.

[0072]

[0071] Being suitable for recycling may be obtained by keeping the overall amount of the single polymer, such as PE, in the lap-sealable film 200 at a high level. Any additives used should be kept to a minimum. Any other polymer types that are present should be minimized. The total composition of the lap-sealable film 200 may include between 80% and 100% of PE, by weight, including any range or combination of ranges therebetween. For example, the total composition of the lap-sealable film 200 is greater than or equal to 90%, including greater than or equal to 95% PE, greater than or equal to 98% PE, or greater than or equal to 99% PE, by weight.

[0073] EXAMPLES AND DATA

[0074]

[0072] Various embodiments will be further clarified by the following examples.

[0075]

[0073] Four film samples were produced for testing. Example 1 included an embodiment of the lap-sealable film 200 having the non-oriented film 100 as the external web and attached to a sealant film 140 that includes the sealing layer 142. In Example 1 , the external web was a 25 micron-thick non-oriented HDPE with a sealable layer that included a polymeric blend of a LDPE and an ethylene copolymer, while the PE- containing sealant film was a 80 micron-thick film with a low SIT sealing layer that included a second polymeric blend of a LDPE and an ethylene copolymer.

[0076] Comparative Example 1 included a 20 micron-thick sealable film containing BOPP in its external web (including trade name B-THL available from Flex Films) and PE as a sealant film (including trade name LDPE foil K-20.02.1 available from MG Italy). Comparative Example 2 included a 25 micron-thick mono-PE film having an HDPE- containing machine direction oriented PE, or MDOPE, in its respective external web. Comparative Example 3 included a 25 micron-thick film having an HDPE-containing biaxially oriented PE, or BOPE, in its external web. However, unlike the Example 1 and Comparative Example 1 , the external web of each of the Comparative Examples 2 and 3 was free from any sealable outer layer (e.g., the first outer layer 110 of the lap-sealable film 200). Comparative Examples 2 and 3 each included a sealing layer substantially similar to or the same as the sealing layer 142 of the lap-sealable film 200 (e.g., Example 1 ) described herein. The external web and the sealant film of each of the Example 1 and the Comparative Examples 1 -3 were laminated using a polyurethane based solvent-free lamination adhesive. Example 1 and Comparative Examples 2 and 3 had a two-component polyurethane based HRL applied in register on their external web.

[0077]

[0074] Unless otherwise stated, tests related to seal strength (for both lap seal and fin seal, for example) and SIT were implemented according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2.

[0078]

[0075] Hot Tack Results

[0079]

[0076] Testing conditions of hot tack analysis of Example 1 and Comparative Examples 1 -3 are provided in Table 1 below. It is noted that the hot tack analysis was implemented by sealing each film in an inside-to-inside fin seal configuration (i.e., sealed to itself).

[0080] Table 1

[0081]

[0077] Referring to Figure 5, which illustrates results of the hot tack analysis, Example 1 and Comparative Examples 2 and 3 each demonstrated a sufficient level of tack at lower temperatures than Comparative Example 1 . Such a difference is likely due to the presence of the respective sealing layers (e.g., a co-extruded PE-based sealing layer having a PE plastomer, a polyolefin plastomer, and / or an ethylene-alpha-olefin copolymer) in Example 1 and Comparative Examples 2 and 3. As described herein, Example 1 and Comparative Examples 2 and 3 each included a mono-PE film, while Comparative Example 1 included BOPP laminated with a regular PE sealing layer, which was reflected by the shift of hot tack towards elevated temperatures.

[0082]

[0078] It was further observed that Example 1 and Comparative Examples 2 and 3 started shrinking at approximately 130° C, while Comparative Example 1 started shrinking at a higher temperature, such as at approximately 140° C. This effect was attributed to the BOPP outer web.

[0079] Fin Seal Strength Results

[0083]

[0080] Testing conditions of a fin seal strength analysis of Example 1 and Comparative Examples 1 -3 are provided in Table 2 below. It is noted that the fin seal strength analysis was implemented by sealing each film in an inside-to-inside configuration (i.e., sealed to itself).

[0084] Table 2

[0085]

[0081] Referring to Figure 6, which illustrates results of the fin seal strength analysis, Example 1 and Comparative Examples 2 and 3 each demonstrated a lower SIT than Comparative Example 1. Such a difference is likely due to the presence of the respective sealing layers (e.g., a co-extruded PE-based sealing layer having a PE plastomer, a polyolefin plastomer, and / or an ethylene-alpha-olefin copolymer) in Example 1 and Comparative Examples 2 and 3, while Comparative Example 1 included a regular PE sealing layer. Furthermore, Comparative Examples 2 and 3 each reached a higher value of maximum seal strength than each of Example 1 and Comparative Example 1 , which may be due to a difference in the failure mode behaviors on the dynamometer.

[0086]

[0082] Based on the seal analysis herein, Example 1 is more prone to elongation before breaking as may be expected from the non-oriented HDPE blown film in Example 1 in comparison to the oriented HDPE films in Comparative Examples 2 and 3, for example. In the case of Comparative Example 1 , the failure mode was reported to be delamination without elongation or breaks. Additionally, strong shrinkage was reported on all of the samples at approximately 140°C.

[0083] Lap Seal Strength Results

[0087]

[0084] Testing conditions of a lap seal strength analysis of Example 1 and Comparative Examples 1 -3 are provided in Table 3 below. It is noted that lap seal strength analysis was implemented by sealing an inside of each film with an outside of the same film in a portion exposed by the HRL (e.g., the HRL 160) as depicted in Figure 4A, for example. The sealed materials were protected with a 12 micron-thick film including PET (PET12).

[0088] Table 3

[0089]

[0085] Referring to Figure 7, which illustrates results of the lap seal strength analysis, Comparative Examples 2 and 3 each demonstrated relatively lower lap seal strength (at less than approximately 5 N / 15 mm) at approximately 140°C, while Example 1 demonstrated relatively higher lap seal strength (at greater than or equal to approximately 20 N / 15 mm) starting at approximately 100°C and with a stable seal strength plateau as the sealing temperature increased. Comparative Example 1 shows lower lap-seal strength compared to Example 1 , the sealing also starting at notably higher temperature.

[0090]

[0086] It is also noted that the lap seal strength values found for Example 1 were higher than what was previously measured for lap sealable BOPE-containing samples (Comparative Examples 4 and 5 in Table 5) available on the market. Comparative Example 4 included a 25 micron-thick HDPE-containing biaxially oriented PE, or BOPE, in its external web (including trade name Ethy-Lyte™ 25HD240 available from Jindal Films). Comparative Example 5 included a 25 micron-thick matte finish, HDPE- containing BOPE in its external web (including trade name Ethy-Lyte™ 25HD230 available from Jindal Films). The samples in this dataset each had a sealant film (e.g., sealing layer) that was similar in composition to the sealing layer described herein (i.e., the sealing layer 142 containing a low-SIT sealant made of a LDPE and an ethylene copolymer). The testing conditions for these samples are presented in Table 4 and the lap seal strength results obtained at different temperatures are shown in Table 5.

[0091]

[0087] Furthermore, it is worth noting that the testing conditions presented in Table 4 were slightly different (e.g., the higher tensile testing speed) from those of Table 3, which could be responsible for the lower values of the lap seal strength observed.

[0092] Table 4

[0093] Table 5

[0094]

[0088] Barrier Properties

[0095]

[0089] Conditions for testing barrier properties of Example 1 and Comparative Examples

[0096] 1 -3 with respect to water vapor transmission rate (WVTR) are provided in Table 6.

[0097] Table 6

[0090] Referring to Table 7, with respect to water vapor barrier properties, each of Example 1 and Comparative Examples 2 and 3 showed a WVTR less than approximately 4 g / m224h, which was comparable to that of Comparative Example 1 . Furthermore, Example 1 offered better protection against moisture ingress compared to the comparative examples.

[0098] Table 7

[0099]

[0091] Bond Strength

[0100]

[0092] Conditions for testing bond strength of Example 1 and Comparative Examples 1 -

[0101] 3 are presented in Table 8.

[0102] Table 8

[0103]

[0093] Referring to Table 9, which illustrates results of the bond strength analysis, Comparative Examples 2 and 3 each demonstrated a bond strength greater than approximately 2 N / 15 mm, which is greater than the bond strength measured for Comparative Example 1 . For Example 1 , no value could be measured because the sample could not be delaminated, indicating a substantially stronger inter-layer adhesion than the comparative examples.

[0104] Table 9

[0105]

[0094] Coefficient of Friction

[0106]

[0095] Results of an analysis of coefficient of friction (COF) of Example 1 are presented in Table 10. Example 1 showed a relatively low COF level in / in (i.e., in an inside-to- inside configuration) and a moderate COF level out / out (i.e., in an outside-to-outside configuration), indicating feasible runnability on a VFFS line. Such properties could however be adjusted by the designs of the formulation of the sealing layer and the HRL.

[0107] Table 10

[0108]

[0096] Mechanical Testing - Elmendorf Tear Resistance

[0109]

[0097] Conditions for testing Elmendorf tear resistance in both the machine direction (MD) and the cross direction (CD) of Example 1 and Comparative Examples 1 and 2 are presented in Table 11. Results of the tear resistance analysis in MD and CD are presented in Table 12 and Table 13, respectively. Table 11

[0110]

[0098] Referring to Table 12 and Table 13, Example 1 and Comparative Example 2 both showed stronger tear resistance than Comparative Example 1 in both the MD and the CD.

[0111] Table 12

[0112] Table 13

[0113] EMBODIMENTS

[0114]

[0099] Embodiment 1 : lap-sealable film comprising: a non-oriented film having a first outer layer and a second outer layer, the first outer layer comprising a first polymeric blend having a low density polyethylene (LDPE) and an ethylene copolymer, and the second outer layer comprising a non-oriented high density polyethylene (HDPE), a heat- resistant lacquer (HRL) attached to an exterior surface of the first outer layer, the HRL being coextensive with less than 100%, by area, of the exterior surface of the first outer layer, and a sealing layer attached to the second outer layer of the non-oriented film, the sealing layer comprising an ethylene copolymer or a second polymeric blend having a LDPE and an ethylene copolymer, wherein the ethylene copolymer has a density less than or equal to 0.92 g / cm3, the first polymeric blend has a seal initiation temperature less than or equal to 110°C when tested in a lap seal configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2, and the lap-sealable film comprises a total composition having greater than or equal to 80% polyethylene.

[0115]

[0100] Embodiment 2: The lap-sealable film according to Embodiment 1 , wherein one or both of the first polymeric blend and the second polymeric blend further comprise one or both of a linear low density polyethylene (LLDPE) and a very low density polyethylene (VLDPE).

[0116]

[0101] Embodiment 3: The lap-sealable film according to any previous Embodiment, wherein the second polymeric blend has a seal initiation temperature less than or equal to 1 10°C when tested in a fin seal configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2.

[0117]

[0102] Embodiment 4: The lap-sealable film according to any previous Embodiment, wherein the ethylene copolymer comprises a terpolymer.

[0118]

[0103] Embodiment 5: The lap-sealable film according to any previous Embodiment, wherein the ethylene copolymer comprises one or more of a polyethylene plastomer, a polyolefin plastomer, or an ethylene-a-olefin copolymer.

[0119]

[0104] Embodiment 6: The lap-sealable film according to any previous Embodiment, wherein the second outer layer comprises greater than or equal to 80% of the nonoriented HDPE, by weight.

[0120]

[0105] Embodiment 7: The lap-sealable film according to any previous Embodiment, wherein the first outer layer has a thickness in a range of from 2 micron to 10 micron.

[0121]

[0106] Embodiment 8: The lap-sealable film according to any previous Embodiment, wherein the second outer layer has a thickness in a range of from 2 micron to 40 micron.

[0107] Embodiment 9: The lap-sealable film according to any previous Embodiment, wherein the non-oriented film has a total thickness in a range of from 4 micron to 60 micron.

[0122]

[0108] Embodiment 10: The lap-sealable film according to any previous Embodiment, wherein the non-oriented film has a lap seal strength greater than or equal to about 8 N / 15 mm when tested according to ASTM F88 with the sealing time of 0.5 seconds and the sealing pressure of 300 N / 15 cm2.

[0123]

[0109] Embodiment 11 : The lap-sealable film according to any previous Embodiment, wherein the sealing layer has a thickness in a range of 2 micron to 40 micron.

[0124]

[0110] Embodiment 12: The lap-sealable film according to any previous Embodiment, further comprising an adhesive layer between the second outer layer and the sealing layer.

[0125]

[0111] Embodiment 13: The lap-sealable film according to Embodiment 12, wherein the adhesive layer comprises polyurethane.

[0126]

[0112] Embodiment 14: The lap-sealable film according to any previous Embodiment, further comprising a printed layer between the second outer layer and the sealing layer.

[0127]

[0113] Embodiment 15: The lap-sealable film according to any previous Embodiment, further comprising a barrier layer between the first outer layer and the sealing layer.

[0128]

[0114] Embodiment 16: The lap-sealable film according to Embodiment 15, wherein the barrier layer comprises one or more of ethylene vinyl alcohol, polyamide, cyclic olefin copolymer, polyvinyl alcohol, polyacrylate, metal, aluminum oxide, or silicon oxide.

[0129]

[0115] Embodiment 17: A package comprising the lap-sealable film according to any previous Embodiment, wherein the package further comprises at least one lap seal bonding the first outer layer of the non-oriented film to the sealing layer.

[0130]

[0116] Embodiment 18: A package comprising the lap-sealable film according to any previous Embodiment, wherein the package further comprises at least one fin seal bonding the sealing layer to itself.

[0131]

[0117] Embodiment 19: A package comprising a lap-sealable film, the lap-sealable film comprising: a non-oriented film having a first outer layer and a second outer layer, the first outer layer comprising a first polymeric blend having a low density polyethylene (LDPE) and an ethylene copolymer having a density less than or equal to 0.92 g / cm3, the first polymeric blend having a seal initiation temperature less than or equal to 110°C when tested in the lap sealing configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2, and the second outer layer comprising a non-oriented high density polyethylene (HDPE), a sealing layer attached to an interior surface of the non-oriented film, the sealing layer comprising an ethylene copolymer or a second polymeric blend having a LDPE and an ethylene copolymer, a heat-resistant lacquer (HRL) attached to an exterior surface of the non-oriented film, the HRL being coextensive with less than 100%, by area, of the exterior surface of the non-oriented film, at least one lap seal, and at least one fin seal, wherein the at least one lap seal is configured to bond the first outer layer to the sealing layer, the at least one fin seal is configured to bond the sealing layer to itself, and the lap-sealable film comprises a total composition comprising greater than or equal to 80% polyethylene.

[0132]

[0118] Embodiment 20: The package according to Embodiment 17, wherein one or both of the first polymeric blend and the second polymeric blend further comprise one or both of a linear low density polyethylene (LLDPE) and a very low density polyethylene (VLDPE).

[0133]

[0119] Embodiment 21 : The package according to any of Embodiments 17-18, wherein the ethylene copolymer comprises one or more of a polyethylene plastomer, a polyolefin plastomer, or an ethylene-alpha-olefin copolymer.

[0134]

[0120] Embodiment 22: The package according to any of Embodiments 17-19, wherein the non-oriented film has a lap seal strength greater than or equal to about 8 N / 15 mm when tested according to ASTM F88 with the sealing time of 0.5 seconds and the sealing pressure of 300 N / 15 cm2.

Claims

What is claimed is:1 . A lap-sealable film comprising: a non-oriented film having a first outer layer and a second outer layer, the first outer layer comprising a first polymeric blend having a low density polyethylene (LDPE) and an ethylene copolymer, and the second outer layer comprising a non-oriented high density polyethylene (HDPE); a heat-resistant lacquer (HRL) attached to an exterior surface of the first outer layer, the HRL being coextensive with less than 100%, by area, of the exterior surface of the first outer layer; and a sealing layer attached to the second outer layer of the non-oriented film, the sealing layer comprising an ethylene copolymer or a second polymeric blend having a LDPE and an ethylene copolymer, wherein the ethylene copolymer has a density less than or equal to 0.92 g / cm3, the first polymeric blend has a seal initiation temperature less than or equal to 1 10°C when tested in the lap seal configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2, and the lap-sealable film comprises a total composition having greater than or equal to 80% polyethylene.

2. The lap-sealable film according to claim 1 , wherein one or both of the first polymeric blend and the second polymeric blend further comprise one or both of a linear low density polyethylene (LLDPE) and a very low density polyethylene (VLDPE).

3. The lap-sealable film according to any one of claims 1 -2, wherein the second polymeric blend has a seal initiation temperature less than or equal to 110°C when tested in the fin seal configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2.

4. The lap-sealable film according to any one of claims 1 -3, wherein the ethylene copolymer comprises a terpolymer.

5. The lap-sealable film according to any of claim 1 -4, wherein the ethylene copolymer comprises one or more of a polyethylene plastomer, a polyolefin plastomer, or an ethylene-o-olefin copolymer.

6. The lap-sealable film according to any one of claims 1 -5, wherein the second outer layer comprises greater than or equal to 80% of the non-oriented HDPE, by weight.

7. The lap-sealable film according to any one of claims 1 -6, wherein the first outer layer has a thickness in a range of from 2 micron to 10 micron.

8. The lap-sealable film according to any one of claims 1 -7, wherein the second outer layer has a thickness in a range of from 2 micron to 40 micron.

9. The lap-sealable film according to any one of claims 1 -8, wherein the non-oriented film has a total thickness in a range of from 4 micron to 60 micron.

10. The lap-sealable film according to any one of claims 1 -9, wherein the non-oriented film has a lap seal strength greater than or equal to about 8 N / 15 mm when tested according to ASTM F88 with the sealing time of 0.5 seconds and the sealing pressure of 300 N / 15 cm2.1 1. The lap-sealable film according to any one of claims 1 -10, wherein the sealing layer has a thickness in a range of 2 micron to 40 micron.

12. The lap-sealable film according to any one of claims 1 -1 1 , further comprising an adhesive layer between the second outer layer and the sealing layer.

13. The lap-sealable film according to claim 12, wherein the adhesive layer comprises polyurethane.

14. The lap-sealable film according to any one of claims 1 -13, further comprising a printed layer between the second outer layer and the sealing layer.

15. The lap-sealable film according to any one of claims 1 -14, further comprising a barrier layer between the first outer layer and the sealing layer.

16. The lap-sealable film according to claim 15, wherein the barrier layer comprises one or more of ethylene vinyl alcohol, polyamide, cyclic olefin copolymer, polyvinyl alcohol, polyacrylate, metal, aluminum oxide, or silicon oxide.

17. A package comprising the lap-sealable film according to any one of claims 1 -16, wherein the package further comprises at least one lap seal bonding the first outer layer of the non-oriented film to the sealing layer.

18. A package comprising the lap-sealable film according to any one of claims 1 -17, wherein the package further comprises at least one fin seal bonding the sealing layer to itself.

19. A package comprising a lap-sealable film, the lap-sealable film comprising: a non-oriented film having a first outer layer and a second outer layer, the first outer layer comprising a first polymeric blend having a low density polyethylene (LDPE) and an ethylene copolymer having a density less than or equal to 0.92 g / cm3, the first polymeric blend having a seal initiation temperature less than or equal to 1 10°C when tested in the lap seal configuration according to ASTM F88 with a sealing time of 0.5 seconds and a sealing pressure of 300 N / 15 cm2, and the second outer layer comprising a non-oriented high density polyethylene (HDPE); a sealing layer attached to an interior surface of the non-oriented film, the sealing layer comprising an ethylene copolymer or a second polymeric blend having a LDPE and an ethylene copolymer;a heat-resistant lacquer (HRL) attached to an exterior surface of the non-oriented film, the HRL being coextensive with less than 100%, by area, of the exterior surface of the non-oriented film; at least one lap seal; and at least one fin seal, wherein the at least one lap seal is configured to bond the first outer layer to the sealing layer, the at least one fin seal is configured to bond the sealing layer to itself, and the lap-sealable film comprises a total composition comprising greater than or equal to 80% polyethylene.

20. The package according to claim 19, wherein one or both of the first polymeric blend and the second polymeric blend further comprise one or both of a linear low density polyethylene (LLDPE) and a very low density polyethylene (VLDPE).

21. The package according to any one of claims 19-20, wherein the ethylene copolymer comprises one or more of a polyethylene plastomer, a polyolefin plastomer, or an ethylene-alpha-olefin copolymer.

22. The package according to any one of claims 19-21 , wherein the non-oriented film has a lap seal strength greater than or equal to about 8 N / 15 mm when tested according to ASTM F88 with the sealing time of 0.5 seconds and the sealing pressure of 300 N / 15 cm2.

Images