RU2807765C1 - Recyclable flexible films and bags for packaging fluid materials - Google Patents

Abstract

FIELD: polymer materials.

SUBSTANCE: co-extruded multilayer films based on an ethylene copolymer and α-olefins, including barrier films and non-barrier films, as well as industrial products that include films, such as flexible bags and containers for fluid materials. Films and products including films have increased resistance to cracking in bending and impact strength. Films and products that include films have good barrier properties because the barrier films include a core layer of an ethylene-vinyl alcohol (EVOH) copolymer having a high ethylene content. The low amount of EVOH copolymer in the entire film, necessary to achieve flex crack resistance, impact strength, and good barrier properties, further allows processing of such films and industrial products.

EFFECT: improved resistance to cracking in bending, resistance to impact loads, and good barrier properties, as well as recyclability.

39 cl, 14 dwg

Description

TECHNICAL FIELD

This application is related to Provisional Patent Application No. US 62/990,540, filed March 17, 2020, and provisional patent application no. US 63/054,309, filed July 21, 2020, claims their priority, and each of the descriptions thereof is incorporated herein by reference in its entirety for all purposes.

TECHNICAL FIELD

This description relates to co-extruded multilayer (CEML) films based on ethylene-α-olefin copolymer, which can be used in the production of flexible bags (for example, for containing, containing, transporting, packaging and /or storage of fluid materials). CEML films can be used in the production of flexible bags, which can exhibit improved resistance to flex cracking, impact resistance and good barrier properties, as well as be recyclable. The disclosed CEML films and flexible pouches containing these films achieve these performance characteristics through combinations of materials that have not been used in the prior art (for example, by including a central barrier layer of ethylene vinyl alcohol copolymer (EVOH) having a high percentage of ethylene (e.g., greater than 32%), wherein the central barrier layer constitutes less than about 5% of the total film thickness or weight).

BACKGROUND ART

Bags used to package flowable liquid products such as food and beverages are typically made using bag forming equipment in which rolls of film are unwound to form the bag. The bag is marked with a code followed by punching a hole to form an opening for the spout. The spout is inserted, the bag is sealed along the long sides and usually brushed to remove air. It is then sealed at the bottom and at the top of the next bag that is made and pulled through the line. The pouch is perforated near the cross seams and packaged for use on the bag-in-box filling line.

Consumers are demanding thinner film bags, especially when packaging flowable/liquid products. This presents a problem as most commercially available films cannot meet these desired physical parameters and also provide insufficient bond strength and impact resistance. As a result, the performance of the bags suffers, especially for bags that are filled with refrigerated products or products that need to be refrigerated during use, storage and transport. Flexible bags ranging from 1 to 6 gallons (equivalent to 3.8 liters to 22.7 liters) made from currently available films exhibit significantly poorer performance, especially when refrigeration is required. These bags may also suffer from ineffective emptying or release of contents and may require the addition of devices that assist in the complete release of fluid contents contained in the bag. Additionally, fluctuations in ambient temperature can create additional challenges in handling, transporting and distributing filled bags. Leakage is a systematic and recurring problem in these bags due to frequent leaks and seam ruptures, primarily on the side and bottom seams, and in the area around the pouch spout.

Beverage pouches are widely available with either a thermoplastic outer barrier layer (plastic) or an adhesive laminate (laminated material) comprising a biaxially oriented (biaxially oriented) nylon 6 core sandwiched with polyethylene/ethylene vinyl acetate (EVA) sealing layers. , from the English ethylene vinyl acetate). The inner layer of these drink bags is usually made of polyethylene. Other pouches for packaging various liquids are based on a thermal or adhesive laminate containing biaxially oriented polyethylene terephthalate (PET) with a vacuum-applied metal coating to provide a highly oxygen impermeable coating construction. However, these types of flexible pouches, which contain biaxially oriented nylon 6 or metallized PET, are not recyclable and therefore are not as desirable, sustainable or environmentally friendly as materials that can be recycled.

Accordingly, there is a need in the art for a multilayer film that provides packaging(s) having excellent strength and durability, capable of withstanding the cold temperatures and temperature changes that are common during use, transportation and handling. Flexible pouches that can release the contents of the pouch (ie, without any means of emptying) are also desirable in light of the savings that such pouches can provide (eg, savings on materials and manufacturing costs). As shown in the following description, the inventors have developed film structures that can provide the required strength and durability while substantially eliminating leaks and seam breaks in bags made using these films. Films and bags incorporating films have good barrier properties, good resistance to flex cracking and excellent self-emptying properties, and can also be recycled, which improves sustainable use later on.

SUMMARY OF THE INVENTION

The present invention generally relates to co-extruded barrier films, pouches containing co-extruded films, optionally in combination with one or more non-barrier films, packaged fluid products containing co-extruded barrier films and/or pouches that contain an amount of barrier material , which provides good barrier performance, impact strength, flex crack resistance and durability, and can also be recycled.

In one aspect, the invention relates to a coextruded (co-extruded) multilayer polymer barrier film comprising at least three layers:

(i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer , while the inner sealing layer has a total density in the range from 0.910 g/cm ³ to 0.924 g/cm ³ ;

(ii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer film, wherein the EVOH contains at least 38% ethylene in the EVOH copolymer; And

(iii) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ .

In one aspect, the invention relates to a coextruded multilayer polymer barrier film comprising at least three layers:

(i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer , while the inner sealing layer has a total density in the range from 0.910 g/cm ³ to 0.924 g/cm ³ ;

(ii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 5% of the total weight or thickness of the coextruded multilayer polymer film, wherein the EVOH contains at least 38% ethylene in the EVOH copolymer; And

(iii) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ .

In another aspect, the invention relates to a coextruded multilayer polymer film comprising five layers:

(i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer wherein the inner sealing layer has a total density in the range of about 0.910 g/cm ³ to 0.924 g/cm ³ ;

(ii) first and second intermediate layers comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the first intermediate layer , and an adhesive or binder resin in an amount effective to promote adhesion of the first and second intermediate layers to at least one other layer in the coextruded multilayer polymer film, wherein the first and second intermediate layers have a combined density in the range of about 0.910 g/cm ³ to 0.924 g/ ^cm3 ;

(iii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer film, wherein the EVOH contains at least 38% ethylene in the EVOH copolymer; And

(iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ .

In another aspect, the invention relates to a coextruded multilayer polymer film comprising five layers:

(i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer wherein the inner sealing layer has a total density in the range of about 0.910 g/cm ³ to 0.924 g/cm ³ ;

(ii) first and second intermediate layers comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the first intermediate layer , and an adhesive or binder resin in an amount effective to promote adhesion of the first and second intermediate layers to at least one other layer in the coextruded multilayer polymer film, wherein the first and second intermediate layers have a combined density in the range of about 0.910 g/cm ³ to 0.924 g/ ^cm3 ;

(iii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 5% of the total weight or thickness of the coextruded multilayer polymer film, wherein the EVOH contains at least 38% ethylene in the EVOH copolymer; And

(iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ .

In another aspect, the invention relates to a coextruded multilayer polymer film comprising seven layers:

(i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer wherein the inner sealing layer has a total density in the range of about 0.910 g/cm ³ to 0.924 g/cm ³ ;

(ii) first and second outer intermediate layers and first and second inner intermediate layers, all intermediate layers containing an ethylene-α-olefin copolymer fraction having a density ranging from 0.894 g/cm ³ to 0.920 g/cm ³ , in an amount of at least about 50% by weight or thickness of the first intermediate layer, wherein all intermediate layers have a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ , and wherein the first and second inner intermediate layers contain an adhesive or binder resin in an amount effective to improve adhesion of the first and second inner intermediate layers to at least one layer in the coextruded multilayer polymer film;

(iii) a central barrier layer adjacent to and located between the first and second inner intermediate layers, wherein the central barrier layer comprises ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer films, wherein EVOH contains at least 38% ethylene in the EVOH copolymer; And

(iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ .

In another aspect, the invention relates to a coextruded multilayer polymer film comprising seven layers:

(i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/ ^cm3 to 0.920 g/ ^cm3 in an amount of at least about 50% by weight or thickness of the total inner seal layer, wherein the inner sealing layer has a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ ;

(ii) first and second outer intermediate layers and first and second inner intermediate layers, all intermediate layers containing an ethylene-α-olefin copolymer fraction having a density ranging from 0.894 g/cm ³ to 0.920 g/cm ³ , in an amount of at least about 50% by weight or thickness of the first intermediate layer, wherein all intermediate layers have a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ , and wherein the first and second inner intermediate layers contain an adhesive or a binder resin in an amount effective to improve adhesion of the first and second inner intermediate layers to at least one layer in the coextruded multilayer polymer film;

(iii) a central barrier layer adjacent to and located between the first and second inner intermediate layers, wherein the central barrier layer comprises ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 5% of the total weight or thickness of the coextruded multilayer polymer films, wherein EVOH contains at least 38% ethylene in the EVOH copolymer; And

(iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer wherein the outer sealing layer has a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ .

In embodiments of any of the above aspects, the coextruded multilayer polymer film may comprise a structure in which a first intermediate layer is located between the inner seal layer and the central barrier layer, and a second intermediate layer is located between the outer seal layer and the central barrier layer.

In some embodiments of the above aspect, the coextruded multilayer polymeric barrier film may comprise an inner seal layer and/or an outer seal layer that contains an adhesive or adhesive resin in an amount effective to improve adhesion of the seal layers to the central barrier layer.

In some embodiments of any of the above aspects, the ethylene-α-olefin interpolymer in at least one of the inner seal layer, outer seal layer, first intermediate layer, or second intermediate layer comprises a linear low density polyethylene polymer fraction and a second ethylene-octene copolymer fraction -1, copolymer of ethylene and hexene-1 or copolymer of ethylene and butene-1.

In some embodiments of any of the above aspects, the interpolymer has a density of 0.915 g/cm ³ and a melt index of from 0.80 dg/min to 1.0 dg/min. In yet another embodiment, the ethylene-α-olefin interpolymer contains at least one metallocene linear low density polyethylene (mLLDPE, for metallocene linear low density polyethylene) having a density of 0.912 g/cm ³ .

In some embodiments of any of the above aspects, the percentage of thickness of the EVOH barrier layer relative to the entire film is selected from the following values: 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 , 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2 ,4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6 , 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4 .9 and 5.0. In some embodiments, the percentage of thickness of the EVOH barrier layer relative to the entire film may range from about 2.5% to about 5.0% (e.g., 2.5 to 5.0, 2.6 to 5.0 , from 2.7 to 5.0, from 2.8 to 5.0, from 2.9 to 5.0, from 3.0 to 5.0, from 3.1 to 5.0, from 3.2 up to 5.0, from 3.3 to 5.0, from 3.4 to 5.0, from 3.5 to 5.0, from 3.6 to 5.0, from 3.7 to 5.0, from 3.8 to 5.0, from 3.9 to 5.0, from 4.0 to 5.0, from 4.1 to 5.0, from 4.2 to 5.0, from 4.3 to 5.0, from 4.4 to 5.0, from 4.5 to 5.0, from 4.6 to 5.0, from 4.7 to 5.0, from 4.8 to 5.0 or from 4.9 to 5.0%), including any individual values and ranges falling within the stated ranges.

In some embodiments of any of the above aspects, the mole percent of ethylene in the EVOH copolymer is selected from greater than about 35 mole percent. In other embodiments, the mole percent of ethylene in the EVOH copolymer is selected from 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, and 55 mole percent. .

In some embodiments of any of the above aspects, the ethylene-α-olefin interpolymer in at least one of the inner seal layer, outer seal layer, first intermediate layer, or second intermediate layer has a melt index in the range of 0.2 dg/min to 2. 0 dg/min.

In some embodiments of any of the above aspects, the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer, or the second intermediate layer has a zero shear viscosity (ZSVR). ratio) in the range from 1.15 to 2.5.

In some embodiments of any of the above aspects, the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer, or the second intermediate layer has a molecular weight distribution expressed as the ratio of weight average molecular weight to number average molecular weight mass (Mw/Mn) in the range from 2.0 to 4.0.

In embodiments of some of the above aspects comprising an intermediate layer, the first intermediate layer is located between the inner seal layer and the central barrier layer, and the second intermediate layer is located between the outer seal layer and the central barrier layer.

In some embodiments of any of the above aspects, any one or more of the seal layers, core layers, and intermediate layers may individually comprise from one to 45 layers of material, inclusive.

In one aspect of the present invention, there is provided a fluid packaging pouch comprising a recyclable barrier coextruded multilayer polymer film and a non-barrier coextruded multilayer polymer film, wherein the barrier coextruded multilayer polymer film comprises:

(i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer, wherein the inner sealing layer has a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ ;

(ii) first and second intermediate layers comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the first intermediate layer layer, and an adhesive or binder resin in an amount effective to promote adhesion of the first and second intermediate layers to at least one other layer in the coextruded multilayer polymer film, wherein the first and second intermediate layers have a combined density in the range of about 0.910 g/ cm ³ to 0.924 g/cm ³ ;

(iii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 5% of the total weight or thickness of the coextruded multilayer polymer film, or of the total weight or thickness of the barrier and non-barrier films, wherein the EVOH contains each at least 38% ethylene in the EVOH copolymer; And

(iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ .

In some embodiments of the above aspect, the package may comprise first and second outer intermediate layers, and first and second inner intermediate layers, all intermediate layers containing an ethylene-α-olefin copolymer fraction having a density ranging from 0.894 g/cm ³ to 0.920 g/cm ³ , in an amount of at least about 50% by weight or thickness of the first intermediate layer, wherein all intermediate layers have a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ , and wherein the first and the second inner intermediate layers contain an adhesive or binder resin in an amount effective to improve adhesion of the first and second inner intermediate layers to at least one layer in the coextruded multilayer polymer film; and wherein the central barrier layer is adjacent to and located between the first and second inner intermediate layers.

In some aspects, the invention relates to a packaged product containing coextruded multilayer polymer barrier films described herein.

In some aspects, the invention provides a packaged product comprising fluid packaging pouches described herein.

In some aspects, the invention provides a method for making coextruded multilayer polymer barrier films described herein.

In some aspects, the invention provides a method for making pouches for packaging fluid materials as described herein.

In some aspects, the invention provides a process for packaging a flowable product including coextruded multilayer polymer barrier films described herein.

In some aspects, the invention provides a method of packaging a fluid product, including pouches described herein.

Additional aspects and embodiments of the invention will be apparent to one skilled in the art in view of the following description and illustrative examples.

BRIEF DESCRIPTION OF GRAPHIC MATERIALS

Fig. 1A-1D illustrate a number of general schematic diagrams of multilayer non-barrier films in accordance with several illustrative aspects and embodiments described herein.

In FIG. 1A shows an example embodiment of a three-layer non-barrier film.

In FIG. 1B shows a five-layer non-barrier film.

In FIG. 1C shows a seven-layer non-barrier film.

Figure 1D shows a seven-layer non-barrier film in which four of the seven layers contain multiple individual layers of the same material stacked on top of each other to form the entire layer.

Fig. 2A-2D illustrate a number of general schematic diagrams of multilayer barrier films in accordance with several illustrative aspects and embodiments described herein.

In FIG. 2A shows an example of a three-layer barrier film in which the inner layer contains a barrier layer.

In FIG. 2B illustrates a five-layer barrier film in which the inner layer comprises a barrier layer.

In FIG. 2C shows a seven-layer barrier film in which the inner layer contains a barrier layer.

In FIG. 2D shows a seven-layer barrier film in which five of the seven layers, including the inner barrier layer, contain multiple individual layers of the same material stacked on top of each other to form the entire layer.

In FIG. 3A-3D show a series of general schematic diagrams of a two-layer film structure that includes multilayer barrier and non-barrier films in accordance with several illustrative aspects and embodiments described herein.

In FIG. 3A shows an exemplary embodiment of a two-layer film structure that includes the three-layer non-barrier and barrier films depicted in FIG. 1A and 2A, respectively, wherein the "outer" layer contains a barrier layer and the "inner" layer contains a non-barrier layer.

In each of the embodiments depicted in FIGS. 3A-3D, the outer and inner layers are not connected to each other except at the edges (welds) to form packets. Within most of the surface area between strata, these strata can be considered "free-floating" in relation to each other.

In FIG. 3B shows an exemplary embodiment of a two-layer film structure that includes the five-layer non-barrier and barrier films depicted in FIG. 1 B and 2 B, respectively, where the “outer” layer contains a barrier layer, and the “inner” layer contains a non-barrier layer.

In FIG. 3C shows an exemplary embodiment of a two-layer film structure that includes the five-layer non-barrier film and the seven-layer barrier film shown in FIG. 1B and 2C, respectively, wherein the “outer” layer contains a barrier layer and the “inner” layer contains a non-barrier layer.

In FIG. 3D shows an exemplary embodiment of a two-layer film structure that includes the seven-layer non-barrier and barrier films shown in FIG. 1D and 2D, respectively, wherein five of the seven layers (including the inner barrier layer) of the "outer" barrier layer and four of the seven layers of the "inner" non-barrier layer contain a plurality of individually stacked layers of the same material to form the entire layer.

In FIG. 4A and 4B are an overview of a flexible pouch (22) in an unfilled form (4A) containing a fluid product (4B), in accordance with exemplary embodiments of the invention, wherein the pouch includes at least one spout (50) that may be positioned in various locations on the bag, and sealed edges (34, 38, 54, 42) around the perimeter that define a volume (26) containing the fluid contents.

INFORMATION CONFIRMING THE POSSIBILITY OF IMPLEMENTING THE INVENTION

Before proceeding to further details regarding the invention, it should be understood that this invention is not limited to specific materials (including polymers, copolymers, interpolymers, additives, etc.), structures and arrangements (including the number of individual layers in the film, the number of film layers , orders of layers and layers of film, etc.), or method steps, as well as intended or envisaged areas of use and application, as these may vary while remaining within the scope of the description provided herein.

Percentages stated in the specification generally refer to either percent weight or percent thickness of the total weight or total thickness of the composition, and are usually indicated when mentioned.

Although differences in the densities of the components (polymers, copolymers, with or without additives) can result in differences in percentages expressed by weight and percentages expressed by thickness, the two percentages are usually very close to each other. All ratios expressed in this document are given in mass ratios unless otherwise noted.

Ranges are used as a shorthand only to avoid listing and describing each and every value within the range. Any suitable value within the range can be selected as the high value, low value, or end point of the range.

The singular form of a word includes the plural form, and vice versa, unless the context clearly indicates otherwise. Thus, references to the singular usually also include the plural of the corresponding terms they define. For example, a reference to “method” includes the plural “ways.” Likewise, the terms “comprises,” “contains,” and “comprising,” whether used as a transitional phrase in a claim or otherwise, are to be construed inclusively and not exclusively. Likewise, the terms “include,” “including,” “has,” “have,” and “or” should be construed as inclusive unless such construction is clearly denied by the context. Likewise, the term “examples,” especially when followed by a list of terms, is intended to be exemplary, illustrative and non-limiting only, and therefore should not be considered exclusive or all-inclusive.

Unless otherwise indicated, all technical, scientific, technical terms and acronyms used in the specification have the meanings commonly understood by those skilled in the art in the relevant fields of technology in which the term is used. Although any compositions, methods, products or other means or materials similar or equivalent to those described herein may be practiced in accordance with the various aspects and embodiments described herein, particular compositions, methods, products or other products or materials are described for purposes of illustration and clarity only.

All patents, patent applications, publications, technical and/or scientific articles and other references cited or referred to herein are incorporated by reference in their entirety to the extent permitted by law. The discussion of these references is intended simply to summarize the statements made in these references. No assumption is made that any such patents, patent applications, publications or references, or any part thereof, are relevant, essential or constitute prior art with respect to the disclosure or scope of the claims.

As used herein, the term "flowable material" does not include gaseous materials, powders or other solid materials, but covers any liquid materials that are gravity-flowable or pumpable. These materials include liquids (e.g. syrup, mixtures, alcohol, milk, water, fruit juice, butter, etc.), semi-solid and liquid emulsions (e.g. ice cream, ice cream mix, soft margarine, whipping cream, dough and etc.). The aspects and embodiments described herein are particularly applicable to flowable foods and beverages, including those that may be packaged at ambient or refrigerated temperatures.

As used herein, the term "density" is defined according to ASTM D 792 and "melt index" is defined according to ASTM D 1238. The "melting point" of a polymer is measured as the peak melting point when performing differential scanning calorimetry (DSC) as described in the ASTM Standard Procedure D3417-83 (Rev. 88).

In FIG. 1A-D are general schematic diagrams of multilayer non-barrier films (100) in accordance with exemplary embodiments of the invention.

As shown in FIG. 1A, coextruded non-barrier films in accordance with the invention typically contain multiple layers, which may be the same or different. The core layer (110) and the sealing layers (120), each of which may be the same or a different polymer or copolymer material, can be coextruded to form a non-barrier film (100). In some embodiments, the non-barrier film may not include a central layer (ie, only two layers). Fig. 1B illustrates an exemplary embodiment of a five-layer non-barrier film (100) having a center layer (110), outer and inner seal layers (120), and outer and inner intermediate layers (130). In FIG. 1C shows an exemplary embodiment of a seven-layer non-barrier film (100) as described, having a center layer (110), outer and inner seal layers (120), first outer and inner intermediate layers (130), and second outer and third inner intermediate layers ( 140). In FIG. 1D depicts a seven-layer non-barrier film (100) similar to the exemplary embodiment shown in FIG. 1C, and includes a similar central layer (110) and second outer and inner intermediate layers (140), but further illustrates an exemplary embodiment in which outer and inner seal layers (1201), and first outer and inner intermediate layers (1301) contain multiple individual layers of the same material stacked on top of each other to form an entire layer.

In FIG. 2A-D are general schematic diagrams of multilayer barrier films (200) in accordance with several illustrative aspects and embodiments described herein. Although the example illustrations and structures in FIGS. 2A-2D are similar to those described in FIGS. 1A-1D, multilayer barrier films and non-barrier films do not need to be equally structured or symmetrical, as discussed in more detail here. In addition, the barrier films (200) shown in FIG. 2A-2D and Figs. 3A-3D, and in accordance with the invention contain a central barrier layer (210), (2101) of ethylene vinyl alcohol (EVOH).

In FIG. 2A shows an example implementation of a three-layer barrier film (200) having inner and outer seal layers (220), which can be made of the same or different materials, and a central barrier layer (210), which contains EVOH barrier material, which can be coextruded to form a barrier film (200). Such embodiments suitably include an adhesive between the central barrier layer and the sealing layers, or the sealing layer may contain some adhesive material to facilitate bonding between the layers.

In FIG. 2B shows an exemplary embodiment of a five-layer barrier film (200) having a center layer (210), outer and inner seal layers (220), and first inner and outer intermediate layers (230). Each of the outer seal and inner seal layers (220), and intermediate layers (230) may be made from the same polymer or copolymer material, or may be made from different polymer or copolymer materials. Accordingly, in some embodiments, the polymer or copolymer used in the outer and inner seal layers (220) may be different and may have different thicknesses. In similar embodiments, the polymer or copolymer used in the inner and outer intermediate layers (230) may be different and may have different thicknesses. In some additional embodiments, the polymer or copolymer used in all of the outer and inner seal layers (220) and the inner and outer intermediate layers (230) may be the same material and have approximately the same thickness.

In FIG. 2C shows an exemplary embodiment of a seven-layer barrier film (200) having a center layer (210), outer and inner seal layers (220), first outer and inner intermediate layers (230), and second outer and inner intermediate layers (240). Any of the outer and inner sealing layers (220), the first and second intermediate layers (230), (240) may be made from the same polymer or copolymer material or may be made from different polymer or copolymer materials. Accordingly, in some embodiments, the polymer or copolymer used in one or another of the sealing layers (220) may be different and may have different thicknesses. In such embodiments, the polymer or copolymer used in the first and second intermediate layers (230), (240) may be different and may have different thicknesses. In some additional embodiments, the polymer or copolymer used in all of the outer and inner seal layers (220), as well as the first and second intermediate layers (230), (240), may be the same material and have approximately the same thickness.

In FIG. 2D shows an exemplary embodiment of a seven-layer barrier film (200) having a general structure similar to the embodiment described in FIG. 2C, wherein five of the seven layers, including the inner central barrier layer (2101), the outer and inner sealing layers (2201), and the first outer and inner intermediate layers (2301), comprise a plurality of individually stacked layers of the same material to formation of the entire layer.

Although not necessarily on the same scale as shown in any of FIGS. 2A-2D or FIG. 3A-3D and as described in various aspects and embodiments of the present invention, the invention relates to films including a central EVOH barrier layer that constitutes 5% or less of the total film (by weight or thickness).

FIGS. 3A-3D show a number of exemplary embodiments consistent with the description of dual-layer film structures, which may include multilayer barrier and non-barrier films described in various aspects and embodiments herein.

In FIG. 3A shows an exemplary embodiment of a two-layer film structure that includes the three-layer non-barrier (100) and barrier (200) films depicted in FIG. 1A and 2A, respectively, wherein the "outer" formation comprises a barrier layer (200) and the "inner" formation comprises a non-barrier layer (100).

The layered strata in all illustrated embodiments in FIGS. 3A-3D are physically connected only at the edges (labeled (310)), and thus may have a gap or separation between the two layers (300) at locations other than the sealed edges (310).

In FIG. 3B shows an exemplary embodiment of a two-layer film structure that includes the five-layer non-barrier (100) and barrier (200) films depicted in FIG. 1B and 2B, respectively, wherein the “outer” formation comprises a barrier layer (200) and the “inner” formation comprises a non-barrier layer (100).

In FIG. 3C shows an exemplary embodiment of a two-layer film structure that includes the five-layer non-barrier film (100) and the seven-layer barrier film (200) depicted in FIG. 1C and 2D, respectively, where the "outer" layer contains a barrier layer (200) and the "inner" layer contains a non-barrier layer (100).

In FIG. 3D shows an exemplary embodiment of a two-layer film structure that includes the seven layers of non-barrier (100) and barrier (200) films depicted in FIG. 1D and 2D, respectively, wherein five of the seven layers of the “outer” barrier layer (200) and four of the seven layers of the “inner” non-barrier layer (100) comprise a plurality of individually stacked layers of the same material to form the entire layer. As discussed herein, different formations do not necessarily have to have the same or similar number of layers or layer structures to fall within the scope of the invention.

Coextruded films

In general, the invention relates to co-extruded (i) non-barrier films and (ii) barrier films that can be combined in any number of ways and combinations to form multi-layer and multi-layer structures that find use in a wide variety of applications.

Materials and film structures for non-barrier and barrier films

In some aspects, the invention provides co-extruded multi-layer (CEML) films that can be used for pouches for packaging liquid fluid materials, including, for example, food and beverage related products. In illustrative embodiments of this aspect, the invention provides a CEML film that is smaller in size (thickness) but exhibits superior impact and bond strength, including under variable temperature conditions (e.g., ambient and refrigerated conditions), as shown in the data presented here indicating higher bag drop heights (F50 values) measured by the Bruceton step drop test.

In some embodiments, the invention provides a non-barrier co-extruded multi-layer (NB-CEML) film that excludes (i.e. does not consist of, include, or contain) the material forming barrier layer (eg, non-barrier embodiments do not include EVOH in any of their layers). In some embodiments, the NB-CEML film may contain interpolymers and film structures, as described in patent application publication US 2018/0370201 (“Bag-in-Box Packaging Film for Refrigerated Liquids”), published December 27, 2018 and in full incorporated herein by reference. Thus, aspects and embodiments of the present invention provide a flexible pouch or bag-in-box package that contains (i) a barrier coextruded multilayer film as described herein, and (ii) a non-barrier coextruded multilayer film as described herein. document, and/or as described, for example, in application publication US 2018/0370201, in which barrier and non-barrier films are combined and edge-sealed as separate sheets in a flexible pouch or pouch-in-box structure.

In some embodiments, the invention provides a barrier co-extruded multi-layer (B-CEML) film that contains a central barrier layer containing EVOH.

In general, embodiments related to non-barrier (NB-CEML) and barrier (B-CEML) film structures may include similar or identical components, materials, thickness and structure, except for the presence of a central layer of EVOH in the barrier film (B-CEML) . Accordingly, in illustrative embodiments, one or both of the barrier and non-barrier films may comprise a coextruded structure, which may be symmetrical or asymmetrical. In some embodiments, the film structures may comprise an outer seal layer, one or more intermediate layers, a central layer, one or more intermediate layers, and an inner seal layer.

In some B-CEML embodiments, the film may comprise one or more intermediate layers between other intermediate layers, or an inner and/or outer seal layer and a central barrier layer. That is, in some embodiments, the B-CEML comprises a first, or first and second, or first, second and third (etc.) inner and/or outer intermediate layer located between the central barrier layer and the sealing layer. In embodiments containing more than one intermediate layer, at least one side of the intermediate layer will border/adjacent to another intermediate layer.

In exemplary embodiments, the coextruded multilayer films may contain from 1 to about 45 or 50 individual layers of polymer film. In other words, either the B-CEML film or the NB-CEML film, or both, may comprise one or more polymer layers which are formed from a plurality of single layers of the same polymer and may be selected from: 2, 3, 4, 5 , 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 , 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, and 50. In some embodiments, the films may contain multiple layers from a range defined by any two numbers given above that include the end points of the range.

For example, B-CEML and NB-CEML films containing five layers are shown in each of FIGS. 1B and 2B and combined to form the two-layer (outer and inner layer) structure shown in FIG. 3B. According to exemplary embodiments, the outer seal layers and the inner seal layers (220), (120) may be made from an ethylene/α-olefin copolymer (EAO) (or "interpolymer"); the first inner and outer intermediate layers (230) or the second outer and inner sealing layers (130) may be made from an ethylene-α-olefin copolymer; and the non-barrier center layer (110) is LLDPE (linear low density polyethylene - LLDPE). In some embodiments, EAO, including low-density polyethylene (LDPE, abbreviated as low-density polyethylene) or LLDPE, may comprise a copolymer of ethylene and 1-octene, ethylene and 1-hexane, or ethylene and 1-butene. In certain additional embodiments, the EAO copolymer may have a melt index from 0.8 dg/min to 1.0 dg/min and a density from 0.912 g/cm ³ to 0.916 g/cm ³ or may include one or more other copolymers or combinations of copolymers that fall within these physical parameters. In some embodiments, any of the layers in the B-CEML or NB-CEML barrier or non-barrier layers may be constructed from a single polymer layer or multiple polymer layers.

In embodiments, the outer seal layer and the inner seal layer may each constitute approximately 10% to 40% of the thickness of the NB-CEML film. In some embodiments containing one or more intermediate layers, each intermediate layer may comprise from about 5% to 20% of the thickness of the NB-CEML film. In some embodiments of an NB-CEML film that includes a core layer, the core layer may comprise approximately 30% to 50% of the thickness of the NB-CEML film.

The overall thickness of the NB-CEML film in some embodiments is from about 1 mil to 5 mil (25 µm to 127 µm), or about 1.5 mil to 4.0 mil (38 µm to 102 µm), or about 1.8 mils to 3.8 mils (46 µm to 96.5 µm) in total film thickness. In some flexible pouch embodiments, the total thickness of the NB-CEML film is greater than 50% of the total thickness of the NB-CEML and B-CEML films that can be used in the flexible pouch. In some embodiments, the thickness of the NB-CEML layer of a flexible package that contains the B-CEML layer and the NB-CEML layer may be 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61. 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 or approximately 75% or more of the total thickness of the barrier and non-barrier formations. In some embodiments of the flexible pouches described herein, a pouch that contains a layer of NB-CEML comprising greater than 50% of the total thickness of the films forming the pouch may provide good spontaneous emptying/recovery of fluid contents without the need for any additional emptying devices.

While a number of multilayer films are known that have been made from various polymers (eg, polyolefins) and polymer blends, such as those described in US Pat. No. 4,503,102; US 4521437; US 5206075; US 5364486; US 5508051; US 5721025; US 5879768; US 5942579; US 5972443; US 6117465; US 6256966; US 6406765; US 6416833; and US 6,767,599 (all of which are incorporated herein by reference in their entirety), in aspects and embodiments described herein, the film may comprise one or more film layers that contain ethylene-α-olefin (EAO) copolymers. Thus, the invention provides films in which one or more EAO copolymers or mixtures of EAO copolymers can be used to form inner and outer seal layers, intermediate layers and a non-barrier core layer. EAO copolymers are selected based on one or more functional or physical characteristics that can provide improved impact strength and pouch drop characteristics, especially in cold conditions, compared to conventional pouches made from multilayer films containing no ethylene-α-olefin copolymers, such as described in this work.

Ethylene-α-olefin copolymer (EAO copolymer)

The description provides an EAO copolymer that can be used within the various aspects and embodiments described herein and can contain, for example, an interpolymer of ethylene and a C4-C10-α-olefin. In some embodiments, the ethylene-C4-C10-α-olefin interpolymer (EAO copolymer) has a melt index of 0.2 dg/min to 2.0 dg/min, 0.4 dg/min to 1.5 dg/min or about 0.5 dg/min to 1.0 dg/min (g/10 min); density from 0.890 g/cm ³ to about 0.930 g/cm ³ (for example, including specific values and narrower ranges falling within this range, such as, for example, from 0.912 g/cm ³ to 0.925 g/cm ³ ; 0.910 g /cm ^{3 ,} 0.911 g/cm ³ , 0.912 g/cm 3 , 0.913 g/cm ³ , 0.914 g/cm ³ , 0.915 g/cm ³ , 0.916 g/cm ³ , 0.917 g/cm ³ , 0.918 g/cm ³ , etc.) and may be one polymer, or a mixture of two polymers, or contain several different individual brands of polymers. As used herein, the term "interpolymer" includes copolymers, terpolymers, and the like.

In some embodiments, the EAO copolymer may have a zero shear viscosity ratio (ZSVR) in the range of about 1.15 to 2.5 (eg, including specific values and narrower ranges falling within this range). In some embodiments, the EAO copolymer may have a molecular weight distribution, expressed as the ratio of weight average molecular weight to number average molecular weight (Mw/Mn), in the range of 2.0 to 4.0 (for example, including specific values and narrower ranges, falling within this range).

The EAO copolymer may be selected from low density polyethylenes (LDPEs), including linear low density polyethylenes (LLDPEs), as well as metallocene-derived LDPEs and LLDPEs (mLDPE, mLLDPE). According to some common industry descriptions, linear low-density polyethylenes in the density range from 0.915 g/cm ³ to 0.930 g/cm ³ may be called LLDPEs, and polyethylenes in the density range from 0.900 g/cm ³ to 0.915 g/cm ³ may be called polyethylenes ultra-low density (ULDPE, from the English ultra-low-density polyethylene) or very low density polyethylene (VLDPE, from the English very low-density polyethylene).

Suitable polymers that can be used to form the various B-CEML and NB-CEML layers and have the performance characteristics described herein are commercially available and sold under various trade names and trademarks, including, for example, ExxonMobil Chemical (for example, polyethylenes and PE polymers with high performance characteristics (EXCEED™ XP, EXCEED™, ENABLE™, EXXONMOBIL™ LDPE, NEXXSTAR™ LDPE, EXXONMOBIL™ LLDPE, EXXONMOBIL™ NTX LLDPE)) and Dow Chemical (for example, polyethylenes (AFFINITY™, AGILITY™, ASPUN™, DOW™ LDPE, DOWLEX™, ELITE™, INNATE™, XUS 59999.38)), as well as other commercial sources. The specific polymer(s) may be selected based on specific performance characteristics as described herein (eg, density, melt index, zero shear viscosity, molecular weight distribution, etc.). In some specific embodiments, the films contain at least one polymer selected from the group of commercially available resins sold under the Dow INNATE™, Exxon EXCEED™ or Exxon EXCEED™ XP trademarks (for example, DOW INNATE™ ST70 Precision Packaging Resin packaging), DOW INNATE™ ST50 Precision Packaging Resin, DOW INNATE™ XUS 59910.03 and DOW INNATE™ TH60 Precision Packaging Resin (Dow Chemical Company, Midland, Milwaukee); EXCEED™ XP 6026 series, EXCEED™ XP 6056ML, EXCEED™ XP 8318ML, EXCEED™ XP 8358 series, EXCEED™ XP 8656MK, EXCEED™ XP 8656ML, EXCEED™ XP 8784 series, EXCEED™ 1012HJ, EXCEED™ 1012MA, EXCEED™ 1012MJ, EXCEED™ 1012MK, EXCEED series ™ 1015, EXCEED™ series 1018, EXCEED™ 1018MA, EXCEED™ 1023MJ, EXCEED™ 1327MA, EXCEED™ 1518MA, EXCEED™ 1518MM and EXCEED™ 2012 Series (ExxonMobil Chemical Company, Houston, TX) In some embodiments, the films contain ethylene-α-olefin copolymer compositions as described in the patent US 9115275, which is incorporated herein by reference. The improved results are described in the illustrative examples below and in accordance with the illustrative aspects and embodiments presented throughout the specification. Some non-limiting examples of the above resins are listed in Table 1 below to provide some additional details regarding some of the physical characteristics of these non-limiting resins.

Film structure and composition Central layer of barrier film

The barrier coextruded multilayer (B-CEML) film contains at least one central layer that is adjacent to a first at least one intermediate layer on one side and a second at least one intermediate layer on the opposite side. At a minimum, at least one layer of the core layer contains EVOH such that the total thickness of all layers containing EVOH is less than about 5%, or about 10% of the total thickness of B-CEML, or about 5% of the combination of B-CEML and NB -CEML. In some embodiments, the thickness of the barrier core layer may be from about 0.1% to 5% of the total thickness of the barrier multilayer film. If the intermediate layer is not used in a multilayer film, then the central layer is adjacent to the sealing layers on either side.

In embodiments, the center layer consists of a single layer, but in alternative embodiments, it may also include a multilayer structure, with each layer having the same or similar EVOH polymer blend as described herein. The thickness of the barrier core layer can be from about 0.1% to 10% of the total thickness of the barrier multilayer film. In some embodiments, the thickness of the barrier core layer may be no more than about 5% of the total thickness of the barrier multilayer film. In some additional embodiments, the thickness of the barrier core layer may be from about 0.1% to 5% of the total thickness of the combination of non-barrier and barrier multilayer films (for example, EVOH is 5.0% or less of the combination of barrier and non-barrier layers of the flexible package according to with the invention). Thus, the central barrier layer contains EVOH, such that in some embodiments, the total thickness of the one or more central barrier layers containing EVOH is less than 5% of the thickness of the B-CEML film and/or a combination film consisting of two layers of NB-CEML and B-CEML.

Thus, in some embodiments and in specific embodiments related to flexible stacks, the total thickness of the EVOH layers, whether in B-CEML or in a stack containing B-CEML and NB-CEML layers, is less than any of the following percentage values of total film thickness (or alternatively as a percentage by weight): 5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2 , 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2 ,9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7 , 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0 ,4, 0.3, 0.2, and 0.1. In embodiments, the total thickness of the EVOH layers is less than a number in the range defined by any two of the above values, including the end points, as a percentage of the total B-CEML thickness. In another embodiment, the combined thickness of the EVOH layers is less than a number in the range defined by any two of the above values, including the end points, as a percentage of the total B-CEML thickness or the combined B-CEML/NB-CEML thickness (e.g., EVOH is 5. 0% or less of the aggregate of barrier and non-barrier layers of the package).

In embodiments, the mole percentage of ethylene in the EVOH copolymer is greater than 35%. In one embodiment, the mole percentage of ethylene in the EVOH copolymer is in the range of 38% to 55%. Thus, embodiments provide a molar percentage of ethylene in the EVOH copolymer selected from the following set of values: 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53 , 54 and 55.

In one embodiment, the barrier layer of the film described herein comprises a coextruded multilayer (CEML) film structure including an outer seal layer, a barrier core layer, and an inner seal layer. In embodiments, the multilayer film comprises, within the barrier core layer, an EVOH containing layer that includes 44 mol% ethylene, with a maximum EVOH thickness of 5% of the total thickness of the multilayer film.

In one embodiment, the EVOH may be a single core layer in a symmetrical or asymmetrical structure, or multiple layers or microlayers in a multilayer structure if the total cumulative thickness of the EVOH is equal to or less than 5% of the total thickness of the structure. Multi-layer and multi-microlayer layering technology is available to those skilled in the art and is incorporated herein by reference (see, for example, US 5,094,793, US 20100215879, US 20140044906, US 20180215121, US 20170197348, US 20140044906, US 2012 0077005, incorporated herein by reference in their entirety).

In embodiments, the EVOH has an ethylene content of 44 mol.% (eg, EVALCA EVAL™ class E). In other embodiments, other lower oxygen barrier grades of EVOH may be included, such as the 38 mole% and 48 mole% ethylene varieties.

External and internal sealing layers (OSL, ISL)

In illustrative embodiments, the invention provides multilayer films (eg, B-CEML and NB-CEML) that comprise at least one outer seal layer and at least one inner seal layer.

The outer seal layer of the film is identified and oriented towards the outside of the film (i.e. furthest from the inner/product contact side of the film), while the inner seal layer, which is also the outer layer of the multi-layer film, is closest to the inside of the package (i.e. in contact with the product). The thicknesses of the outer and inner seal layers may be the same, but in some embodiments, the inner and outer seal layers may have different thicknesses. In embodiments, the outer or inner seal layers may comprise more than one layer of film, such as 2, 3, 4 or more (eg, up to about 50) layers of film.

In embodiments, the encapsulation layers may comprise from about 10% to 100% by weight ethylene-α-olefin copolymer or combinations thereof as described herein, and may contain up to 100% by weight ultra-low density polyethylene (ULDPE) polymer ) or linear low-density polyethylene (LLDPE), which in some embodiments contains a copolymer of ethylene and an α-olefin, wherein the α-olefin chain may consist of 4 or more carbon atoms (for example, butene-1) or 6 or more carbon atoms ( for example, hexene-1) or 8 or more carbon atoms (for example, octene-1), or combinations thereof, having a density ranging from about 0.910 g/cm ³ to 0.914 g/cm ³ and a melt index from about 0.7 dg /min to 1.0 dg/min. In some embodiments, the encapsulation layers may comprise an amount (e.g., about 5% to 50%) of linear low-density polyethylene (LLDPE), which in some specific embodiments comprises a copolymer of ethylene-1-hexene or ethylene-1-octene, or combinations thereof having a density ranging from about 0.915 g/cm ³ to 0.925 g/cm ³ and a melt index from about 0.7 dg/min to 1.0 dg/min.

In some embodiments, the copolymer of the encapsulation layers may comprise from about 75% to 90% by weight ultra-low density polyethylene (ULDPE) having a density ranging from about 0.911 g/cm ³ to 0.913 g/cm ³ and a melt index from about 0.8 dg/min up to 0.9 dg/min; and from 10% to 25% by weight of linear low density polyethylene (LLDPE), which may contain an ethylene-α-olefin copolymer (for example, ethylene-1-octene copolymer and/or ethylene-1-hexene copolymer) having a density in the range from about 0.918 g/cm ³ to 0.922 g/cm ³ and a melt index from about 0.8 dg/min to 0.9 dg/min. In some embodiments, the copolymer of the seal layers may have a density of from about 0.910 g/cm ³ to about 0.925 g/cm ³ (for example, 0.917 g/cm ³ , 0.915 g/cm ³ , 0.912 g/cm ³ , etc.) and a melt index of about 0.7 dg/min to 1.0 dg/min (eg, 0.9, 0.8, etc. dg/min). In embodiments, the density range may also be defined by any two of the following g/cm ³ values, including endpoints: 0.910, 0.911, 0.912, 0.913, 0.914, 0.915, 0.916, and 0.917 g/cm ³ .

In some embodiments, the thickness of each of the sealing layers ranges from about 1% to about 25% of the total thickness of the CEML films. That is, each of the inner and outer seal layers may have a thickness (or weight) expressed as a percentage of the total thickness (or weight) of the CEML film of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23% , 24% and 25%.

In some embodiments, the thickness of the sealing layers is within the range defined by any two of the above numbers, including the end points. The thickness of the sealing layers may also be percentages intermediate between the percentages indicated above, for example, from about 11.1%, 11.2%, 11.3%, 11.4%, etc. (for example, between 11% and 12 % indicated above).

Intermediate layer

In accordance with exemplary embodiments described herein, the films contain one or more intermediate layers, which may contain the same or similar polymeric materials in the same or similar ratios as the sealing layers described above, and may further contain additional polymer components and additives, for example, to vary the density and melt index in the above ranges, the polymer components may be in different ratios, and adhesives and binders may be added to facilitate film formation.

In accordance with the illustrative aspects and embodiments described herein, films may comprise a plurality of intermediate layers (eg, second, third, fourth, fifth, etc. inner and outer intermediate layers). Generally, any layer that is not disclosed or described as a core layer or seal layer is characterized as an “intermediate layer,” and in embodiments that include more than one intermediate layer, intermediate layers adjacent to the seal layers are referred to as an “intermediate layer.” layer", and in embodiments that contain more than one intermediate layer, the intermediate layers adjacent to the sealing layers are referred to as the "first" inner/outer intermediate layer, and subsequent intermediate layers are referred to as the second, third, fourth, as they occur. approaching the film located inside the central region.

Although the barrier or non-barrier coextruded multilayer (NB-CEML) films described herein may contain an intermediate layer adjacent to the seal layer and adjacent to the central layer, the term is intended for use in accordance with the present invention to refer to the polymer or copolymer layers located between the seal layer and a core layer or between two or more core layers in a B-CEML and NB-CEML film (ie, for example, some core layers in NB-CEML may not include a barrier layer such as EVOH). Thus, in some embodiments, one or both of NB-CEML or B-CEML may comprise first intermediate layer(s) and/or second intermediate layer(s), such that, for example, a multilayer film may have one or more intermediate layers located between the sealing layers and the central/central barrier layer, and/or two or more central/central barrier layers. In some embodiments, as described for the liner and core layers, the intermediate layers may comprise a plurality of individual layers (eg, up to about 45 or 50 layers) that together form the first (or second or more) intermediate layers.

Thus, in some embodiments, the intermediate layers may comprise an ethylene-α-olefin copolymer as described herein. In some embodiments, the copolymer may comprise a copolymer of ethylene and an α-olefin or a combination thereof (an α-olefin with a carbon chain length of 4, or 6, or 8 or more) having a density (or density when combined) of about 0.910 g/cm ³ to about 0.925 g/cm ³ (for example, 0.917 g/cm ³ , 0.915 g/cm ³ , 0.912 g/cm ³ , etc.) and a melt index from about 0.2 dg/min to 2.0 or from about 0.5 dg/min to 1.0 dg/min or from about 0.7 dg/min to 1.0 dg/min (for example, 0.9, 0.8, etc. dg/min) . In embodiments, the density range may also be defined by any two numbers specified below, in g/cm ³ , including the endpoints: 0.910, 0.911, 0.912, 0.913, 0.914, 0.915, 0.916, and 0.917 g/cm ³ . Likewise, the melt index range may be defined by any two numbers described above in dg/min, including endpoints, and in some specific embodiments may be 0.5, 0.6, 0.7, 0.8, 0 .9 and 1.0 dg/min. In some embodiments, the total thickness of each intermediate layer may range from about 1% of the total film thickness to about 40% of the total film thickness.

In some embodiments, the intermediate layer contains an amount of an agent, such as an adhesive material (e.g., a binder resin or adhesive), that facilitates binding and adhesion of the intermediate layer to the central EVOH barrier layer and, optionally, to other intermediate layers and/or sealing layers . Any known binder resins and adhesives may be used in the intermediate layer, including, for example, polyethylene copolymers of polar and non-polar repeat units with or without functional reactive groups. Modifiers may be added to further improve certain physical properties, such as peel strength, of such binders, adhesives, and binder resins. Some non-limiting examples of binder resins include non-reactive binder resins such as ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA), acid-modified olefin copolymers (e.g., ethylene acrylic acid (EAA). ethylene acrylic acid) and ethylene methacrylic acid (EMAA), as well as reactive binder resins such as anhydride modified polyethylene (i.e., ethylene grafted maleic anhydride (AMP, anhydride modified polyethylene) )).

Central layer of non-barrier film

The non-barrier coextruded multilayer (NB-CEML) film may comprise a core layer that is adjacent to inner and outer seal layers or intermediate layers and is typically located within a film laminate structure. In embodiments in which the NB-CEML comprises an intermediate layer in a multilayer film, the central layer is adjacent to the intermediate layer(s) on either side thereof. In embodiments, the core layer may comprise a polymer or polymer blend comprising: 0% to 100% by weight, about 30% to 70% by weight, or about 30% to 50% by weight linear low density polyethylene (LLDPE) from an ethylene-octene-1 copolymer having a density of about 0.910 g/cm ³ to 0.920 g/cm ³ and a melt index of about 0.8 dg/min to 1.2 dg/min. In embodiments, the core layer may further comprise from 0% to 100% by weight linear low density polyethylene (LLDPE), such as ethylene-1-butene copolymer or low-density ethylene-hexene-1 copolymer having a density of from about 0.918 g/cm ³ to 0.930 g/cm ³ and a melt index of from about 0.8 dg/min to 1.2 dg/min, or from about 70% to 30% by weight, or from 50% to 70% by weight of these copolymers.

In yet another embodiment, the core layer comprises a polymer blend of: 35% to 45% by weight linear low density polyethylene (LLDPE) ethylene-1-octene copolymer having a density of about 0.914 g/ ^cm3 to 0.918 g/ ^cm3 and a melt index of about 0.9 dg/min to 1.1 dg/min; and from 55% by weight to 65% by weight linear low density polyethylene (LLDPE) of ethylene-butene-1 copolymer having a density of from about 0.918 g/cm ³ to 0.920 g/cm ³ and a melt index from about 0.9 dg /min to 1.1 dg/min.

Depending on the product and the conditions under which the product is stored, transported and used, the NB-CEML core layer may contain up to 100% by weight ethylene-α-olefin copolymer under the conditions described in this work. The percentage of copolymer can vary from 5, 10, 20, 30, 40, 50, 60, 70, 80 and 90% to any amount depending on the desired or required properties of the NB-CEML film. In embodiments, the core layer may be a single layer, but may also comprise a multilayer structure in which each layer has the same or similar polymer blend within the above ranges. The thickness of the NB-CEML core layer may be approximately 30% to 50% of the total thickness of the NB-CEML multilayer film.

Application

In embodiments, the invention provides flexible liquid packaging pouches consisting of two or more layers, wherein at least one layer is a barrier layer (B-CEML film) and at least one layer is a non-barrier layer (NB-CEML film). ) in accordance with the aspects and embodiments described above. Thus, the barrier layer contains a B-CEML film structure containing EVOH in an amount of 5% or less of the total thickness of the layer or B/NB layer combination. In such embodiments, the flexible pouch does not contain (ie, does not contain or consist of) nylon, polyester, or metal, such as, for example, vacuum deposition metal or aluminum foil. In embodiments, the outer layer of the pouch comprises a B-CEML film structure containing EVOH in accordance with the invention, and the inner ply of the pouch may comprise a non-barrier film containing no EVOH. In some additional embodiments, the non-barrier inner layer of the pouch is thicker than the barrier outer layer by a ratio of from about 1.1:1 to about 3:1, including any ratio in this range (e.g., 3.8 mil:1.8 mil, which corresponds to 96.5 µm: 46 µm). In such embodiments, the thickness of the inner layer may provide better spontaneous ejection efficiency of the contents of the flexible pouch.

In one embodiment, the EVOH-containing barrier layer or layers may form the outer layer or layers of the flexible package (eg, the outer and middle layers of multi-layer packages), and the non-barrier layer may form the inner layer of the package. Alternatively, the barrier layer may be placed as the inner layer of the package.

In embodiments, the bag size may range from 0.5 US gallons to 10 US gallons (corresponding to 1.9 L to 37.8 L) (e.g., about 1, 2, 3, 4, 5, or 6 gallons, corresponding to 3.8, 7.6, 11.4, 15.1, 18.9 or 22.7 l). In some embodiments, the size may also be expanded to bulk pouches in the 10 to 45 and 45 to 400 gallon size range (corresponding to 37.8 to 170.3 L and 170.3 to 1514 L) (i.e. The bags can cover a wide range of sizes from about 0.5 US gallons to about 400 US gallons, corresponding to about 1.9 L to about 1514 L). In some embodiments, packages may include a plurality of layers (ie, there may be more than two layers in a package). Such embodiments, for example, may include a combination of two barrier layers and one non-barrier layer or one barrier layer and two non-barrier layers in different structural arrangements. In accordance with the foregoing aspects and embodiments, the thickness of the EVOH-containing barrier layer in such pouches may range from 1 to 10 mils (25 μm to 254 μm), and in some specific embodiments may be about 1.5, 1.6 , 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2 ,9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1 , 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 mils (where 1 mil equals approximately 25 mm). In embodiments, the thickness of the non-barrier layer may be approximately the same thickness as described above for the barrier layer (e.g., in the range of 1.5 to 5.0 mils (25 to 127 μm), 2.5 to 5.0 mils (63.5 to 127 microns), 1.5 to 4.0 mils (38 to 102 microns), and similar ranges within the general range specified above). In other embodiments, the thickness of the non-barrier layer is greater than the thickness of the barrier layer, as described above.

In some embodiments, a flexible pouch is used to package concentrated soft drink syrup (eg, a beverage pouch). In some embodiments, the flexible pouch is used to package edible oil. In some embodiments, the flexible pouch is used to package liquid dairy products (in ambient or refrigerated conditions). In some embodiments, the flexible pouch is used to package non-food products, industrial liquids, or chemicals. In some embodiments, the flexible pouch contains pigmented layers to impart color (white, blue, black, etc.).

In embodiments, the pouches contain a maximum amount of EVOH throughout the pouch structure that is no more than 5.0%, 4.5%, 4.0%, 3.5%, 3.0%, or 2.5% of the total thickness, or mass of the film structure. In embodiments containing a barrier and non-barrier multilayer structure, the total amount (thickness or weight percentage) of EVOH in the entire multilayer structure is reduced since the non-barrier film sheets do not contain EVOH. In embodiments related to pouch structures, neither nylon, nor PET (polyethylene terephthalate), nor metallization are used. In some embodiments, the pouches do not contain any thermoplastic or adhesive laminates. In some embodiments, pouches are made for packaging liquids at ambient temperatures, such as concentrated beverage syrups, edible oils, as well as industrial liquids such as soaps, detergents, and the like. As described herein, flexible pouches in accordance with the invention may find use in the dispensing and dispensing of viscous liquids such as food products (eg, premix syrups for the preparation of beverages). The pouches typically have thin, flexible polymer walls sealed at the edges and have a dispensing spout or closure sealed to the wall of the pouch. See, for example, FIG. 4A-4B. General images of the package in Fig. 4A-4B are merely illustrative of non-limiting embodiments of the invention. As described herein, flexible pouches can be designed and manufactured according to any number of parameters (e.g., including more than one dispensing device in different locations, different pouch shapes, delta joints at any one or more corners of the pouch, hanging holes, and others designs generally known in the art).

In use, the flexible pouch is filled with a flowable material to be packaged, and the pouch may be packaged in a relatively rigid container, such as a corrugated cardboard box, for distribution (eg, a bag-in-box). Typically, the spout or closure on the flexible pouch is configured to mate at the point of use with a dispensing valve or a supply line connector is connected to it to control and direct the dispensing of the contents of the pouch. Because the pouch walls are thin and very flexible, pouches in normal use may break when the contents are removed. A problem that arises in the art and that flexible pouches in accordance with aspects and embodiments of the present invention solve is that when dispensing the liquid contents of the pouch, it is possible that one of the flexible walls of the pouch may move close to the spout, even if significant Some of the contents remain in the package. The wall of the bag may cover the inner end of the spout, thereby blocking it and blocking the flow of contents. Due to the pressure of the liquid remaining in the bag on the wall, it is difficult and problematic to dislodge the wall from the spout and remove the blockage. In the prior art, this is typically addressed by including one or more release aids that are designed and adapted to maintain flow by preventing blockage due to pouch collapse.

In some embodiments, flexible pouches in accordance with the present invention can support the flow and release of pouch contents without the need for aids known in the art, such as outlets, tubes, molds, dip strips, or reinforced/embossed films that may help ensure complete extraction of the package contents. Unexpectedly, it turned out that the inner and outer layers of the bags described in this document, although demonstrating increased strength, have a structure that provides sufficient rigidity to the geometry of the bag and ensures complete spontaneous extraction of its fluid contents. That is, it has been unexpectedly discovered that the fluid contents in the flexible pouches of the present invention reach and flow through the spout even when the contents of the pouch are completely or substantially emptied, without the need for any additional emptying aid(s).

Thus, flexible bags are convenient in that they can be made relatively flat when unfilled and, accordingly, they are convenient to store and transport to the filling site (the geometry of the bag is not distorted due to the presence of an extraction aid). Additionally, pouches in accordance with exemplary embodiments of the present invention do not require any device to be inserted into the pouch after it has been formed, thereby reducing manufacturing complexity.

In addition, bags in accordance with illustrative embodiments of the invention are well suited for use with supply line connectors that are provided with quick-release connectors and valves. Such quick release connectors and valves may utilize a valve element that slides within the closure or spout, protruding into the pouch when actuated by insertion of a supply line connector, and extending within the closure to shut off the flow of contents when the connector is removed. In such applications, the bags of the present invention avoid any possible interaction between the slider of such a valve and the outlet channel or structure that will be attached to the spout or its periphery.

When used, bags in accordance with illustrative embodiments of the present invention are capable of spontaneous recovery of fluid materials/contents to levels meeting industry requirements (i.e., recovery of 95% or more of the contents (95%, 96%, 97%, 98 %, 99%, 99.5%, 99.6%, 99.7%, 99.8% or 99.9%)) without the need to use auxiliary devices when removing. This observed level of emptying without the need or assistance of an integral retrieval structure is unexpected and provides a significant advantage to the flexible pouches described herein over the state of the art. In use, the observed superior content recovery rates are achievable with various orientations of flexible pouches or pouches in a box, such as, for example, with the dispensing spout facing the bottom as well as side-facing devices.

Supplements

In some embodiments, the films may contain standard additives commonly known and used in the art, including, for example, antioxidants, stabilizers, antiblocking agents, and glidants. Optionally, any one or more seal layers or intermediate layers may contain one or more additives that can facilitate processing of the film in the pouch making process, such as, for example, polymer processing aid concentrates, and/or slip/anti-block additive concentrates . Any of such additives that are generally known and used in the art may be used, including the following types of additives.

Additives that increase slip

Any slip agent known in the art may be included in the film layers, typically in an amount of from about 200 ppm to 2000 ppm or from 0.5% to 2.5% by weight of a particular layer. In some embodiments, the slip additive may be added in an amount of less than about 200 ppm (even down to zero, i.e., 0 ppm) if the anti-slip agent is added in amounts that provide some function that was would be provided by the addition of one or more slip additives. Non-limiting examples of glidant additives include erucamide or other fatty acid amides such as oleamide. A slip additive can reduce the coefficient of friction of the film and allow it to glide easily on a variety of surfaces.

Anti-caking agents

Any anti-blocking agent known in the art may be added to the film layers, typically in an amount of about 1000 to 5000 ppm or 0.5% to 2.5% by weight of the seal layer or intermediate layer. However, in some embodiments, the amount of antiblocking agent(s) can be increased to about 10,000 ppm without any adverse effect on the properties and performance of the film. For example, typical anti-blocking agents such as diatomaceous earth, synthetic silica or talc may be added to the inner and outer seal layers of the film. The anti-block material may help reduce the coefficient of friction between the film and the metal surfaces over which the film is stretched in a pouch making process.

Technological additives

Any processing aid known in the art, such as a non-limiting example of a fluoroelastomer polymer, can be added to the outer and inner seal layers of the film.

The films described herein can be used in the manufacture of various products, including a flexible pouch containing a flowable material, wherein said flexible pouch is made from the above-described multilayer film in a tubular form and has transversely sealed ends.

In some embodiments, the invention provides a method for making pouches filled with a flowable material using the conventional pouch making method described herein. The pouches can be made using a vertical form, fill and seal ("VFFS") machine, in which each pouch is made from a flat web of film by forming it into a tubular film with a longitudinal seam and then flattening the tubular film in a first position, and transversely heat sealing the tubular film in the flattened state, filling the tubular film with a predetermined amount of flowable material above said first position, flattening the tubular film over a predetermined amount of fluid material in the second position, and transversely heat sealing the tubular film in the second position wherein the improvement includes making pouches from a flat film web made from the multilayer film described above. VFFS methods and modifications thereof are described in US Pat. Nos. 5,538,590, US 9,327,856, and US 9,440,757 and are incorporated herein by reference in their entirety.

While melt index ranges have been described in various aspects and embodiments, it will be understood that polymers with melt indexes characteristic of film grade polymers can be used. The multilayer films of the present invention are capable of forming a lap seam as well as a seam joining the edges of the material. They also significantly reduce curling of the laminate.

One of the film production methods is the so-called blown film production method. After production, the film is cut longitudinally into films of the appropriate width. The method for making multilayer film is to use a co-extrusion blown film method, although other film making methods can be used.

Flexible bags and layers in large bags

As discussed herein, the invention provides pouches that include an EVOH barrier layer in a polyolefin film, resulting in pouches having sufficient flex crack resistance, sufficient impact strength, and sufficient barrier properties for flowable materials with a short shelf life but suitable recyclable because they do not contain nylon, PET or their metalized variants. In particular embodiments, flexible packaging made from the films described herein can have a wide range of sizes, from small bags (for example, 100 ml to 2500 ml), small bags (for example, 1 to 6 US gallons, corresponding to 3. 8 L to 22.7 L) or larger bags (e.g. 50 to 400 US gallons, corresponding to 189.3 L to 1514 L) containing NB-CEML and B-CEML films and can be used for packaging liquids including, for example, dairy products, milkshakes, confectionery, hot sauce, coffee, vegetable and fruit juices, sauces and purees. It was found that adding a small amount of EVOH—less than 5% by film thickness or less than 5% by film weight—surprisingly resulted in improved flex crack resistance, increased impact strength, and improved barrier properties compared to the prior art. This also allows for the elimination of the use of materials such as nylon, PET or metallized variants thereof to provide barrier properties that would otherwise make such films and bags unrecyclable.

In embodiments of the invention, the flexible pouches do not have a liner, providing liner-less pouches that may consist of a single ply or multiple plies but no liner. In embodiments, a thermally laminated polymer film structure is produced comprising B-CEML type films described herein. The bags, which can be made from B-CEML/NB-CEML films, can be pre-formed and then filled with food products through the closure. They are often sterilized and may, for example, be irradiated in a batch process using standard irradiation conditions known in the art. It is also possible to sterilize the film rather than the bags. Sterilization can be achieved by various known methods, such as exposing the film or bag to a solution of hydrogen peroxide. Films used to make bags can be processed in a similar way before forming the packaging.

Bag production

In one aspect, bags can be manufactured by a method including the following steps:

providing one or more of the films described herein, including CEML barrier film,

attaching the spout to the inner and outer layers of the film structure through the hole provided in it,

jointly sealing the layers across the width of the film structure to form the top seam of one package and the bottom seam of this package, as well as the top seam of the adjacent package, then

joint sealing of layers parallel to the length line of the package on both sides of the polymer films, and removal of trapped air before complete sealing of the package, and

separating packages immediately or immediately before use.

Representative methods for making pouches are generally described in US Pat. No. 8,211,533, which is incorporated herein by reference.

In some embodiments, a method for making flowable pouches may involve using a pouch production line where each pouch is made from a flat web of film, which may include the following steps:

(I) Unwinding the film from two rolls at the top and two rolls at the bottom.

(II) Inkjet printing of code on each bag.

(III) Punching a hole for the spout in each bag.

(IV) Inserting the spout into the bag.

(V) Smoothing the bag to remove trapped air.

(VI) Formation of transverse seams at the bottom of one package and at the top of the next package.

(VII) Formation of longitudinal seams.

(VIII) Pulling bags through the line using a servo drive.

(IX) Formation of perforation between adjacent transverse seams.

(X) Pushing packages to the end of the line along a conveyor belt.

(XI) Packing packages into boxes.

The above steps are typical for a bag making machine.

It should be noted that the order of the steps may be changed depending on the bag making machine.

The following examples will help to provide further illustration and clarity of the invention, as well as the aspects and embodiments described above.

DESCRIPTION OF EXAMPLES OF IMPLEMENTATION OF THE INVENTION EXPERIMENT 1

Co-extrusion of multilayer films and bags containing films

The examples detail a series of experiments in which multilayer films were produced using film extrusion processes that are widely known and used in film production. The films can be extruded on a conventional multilayer film extrusion line, such as three-layer, five-layer, seven-layer, nine-layer or even more layers, blown film extrusion line, co-extrusion line. Films based on polymer (resin) compositions in accordance with aspects and embodiments of the invention can also be made using other film extrusion processes known and used in film production.

Non-limiting exemplary operating conditions for making multilayer films may include those listed in Table 2:

Film thickness may vary as described herein, but can suitably range from about 1.5 or 1.8 mils (or about 38 microns to 45 microns) to about 3.8 mils (or about 96.5 microns) .

The films are used to produce test bags (eg, 5-gallon (18.9 liter) bags) at a typical throughput (eg, 25 bags/min). Bags are made consisting of two layers in which the edges of the bag are welded (soldered) together, for example, using conventional technologies (for example, thermal welding (sealing), for example, using a Maverick bag production line or pulse welding, etc. ). Overall dimensions of a 5 gallon (18.9 liter) bag can be approximately 18.75 inches (47.6 cm) in outside width and 24.75 inches (62.9 cm) in outside length. A hole with a spout and a lid can be formed in the bag.

The films were formed using typical extrusion conditions as described or otherwise known in the art. CEML barrier films include an EVOH layer in a core layer stack and are used to provide exemplary embodiments of the invention.

Bruceton Step Drop Test (ASTM D 5276 A Version 2.4.2)

The Bruceton step drop test is used to evaluate the strength/resilience of the package. Typically a test involves a set (eg, about 30) packets. The first bag is positioned so that the longitudinal axis of the bag is aligned with an imaginary horizontal line, the bottom surface of the bag is at a suitable initial drop height (e.g., 8 feet, or approximately 2.44 m), and the vertical seam is facing upward. In this orientation, the bag is dropped onto a stainless steel sheet and then inspected visually and tactilely for damage or leaks. Depending on the intended use of the bag, the test may be conducted by maintaining a constant or varying temperature of the bag between tests (eg, approximately 4°C ambient or 40°C).

If the first bag survives the drop test intact and watertight, a new bag is selected and dropped an additional 1 ft (0.3 m), such as 9 ft (2.74 m). Alternatively, if the first bag leaks, select a new bag and drop it from a height that may be lower (eg, 7 feet (2.13 m)). The test continues with a new package for each drop until at least 5 passes and 5 failures have occurred in the height range where both test passes and failures occur. The 50% failure height is then calculated using a statistical method according to ASTM 1 D 5628.

Some of the drop tests below were performed as follows: Flexible bags were filled to approximately a total weight of 41.6 lbs (19 kg). The bags were dropped flat, with the closure pointing upward. The temperature of the water in the bags was recorded. For each trial, 30 packets were dropped. The F-50 value is the average height of the package dropped in feet. The temperature of the water in the filled five-gallon bags during the Bruceton drop test was 60-65°F (16-18°C).

Resistance to flex cracking

The Gelbo Flex testing machine was used to determine the flex crack resistance of the films used to make the flexible pouches of the present invention, as well as comparative, reference or control samples. The test is described below. The film in accordance with aspects and embodiments of the invention exhibited unexpectedly improved flex crack resistance properties compared to films of comparative embodiments. Comparison films are alternatively also called "control" or "reference" films or variants.

This test determines the puncture resistance of flexible packaging materials and films due to bending. However, it does not measure any abrasion characteristics associated with flexural failure. The turpentine colored portion of the test measures failures characterized by the presence of physical holes through the structure.

The Gelbo Flex testing machine is configured to test according to ASTM F392. This machine consists essentially of a 3.5 inch (90 mm) diameter stationary mandrel and a 3.5 inch (90 mm) diameter movable mandrel spaced 7 inches (180 mm) apart at the starting position - i.e. maximum distance - shaft travel. The sides of the film sample are fixed on round mandrels so that a hollow cylinder is formed between them. The movement of the movable mandrel is controlled by a grooved shaft to which the movable mandrel is attached. The shaft rotates through 440 degrees and at the same time moves toward a stationary mandrel that crushes the film so that mandrels facing each other are as close as 1 inch (25.4 mm) apart. The movement of the machine is reciprocating, with forward and backward movements completing a full cycle. The machine operates at a speed of 45 cycles per minute.

This testing machine bends flexible material samples under standard atmospheric conditions (23°C and 50% relative humidity) unless otherwise specified. The number of flex cycles may vary depending on the flex crack resistance of the film structure being tested. The bending action produced by this machine consists of a twisting motion, thus repeatedly twisting and compressing the film.

Bending failure is determined by measuring micro-holes formed in the film. Holes are determined by painting one side of a test film sample (300 cm ² in area) with colored turpentine and passing it through the holes onto a white backing or blotting paper. Pinhole formation is the standard criterion presented for measuring failure, but other tests such as gas permeation rate may be used instead of or in addition to the pinhole test. The results shown are the average of four replicates.

Below is data from Gelbo Flex, which was obtained using many more flex cycles than suggested in the ASTM standard method - 10800 compared to the usual 2700 cycles for coextruded films. A higher number of cycles, i.e. 10,800 cycles, was used to test the differences between the two samples as this provides a better correlation of what is happening in the field.

Oxygen transmission

The Oxygen Transmission Rate (OTR) test determines the reduction in oxygen transmission in the film used to make the flexible pouches of the present invention. The test is described below.

A film sample of the appropriate size was cut on a cutting mat using the MOCON jig for the Mocon Oxtran machine. The cut film sample was then placed into Mocon Oxtran and clamped into position according to the specific requirements of the machine. The test parameters on the machine were set according to ASTM D3985. Parameter settings are based on industry standard tests. The test temperature was set at 23°C and 60% relative humidity. The sample was tested until the graph showed a plateau, and the testing time varied from 8 to 70 hours depending on the curve of the graph. All results were recorded in units of cm ³ /100 in ² per day.

Packages made from inner layer NB-CEML and outer layer B-CEML

Example 1 of the invention

Flexible pouches in accordance with aspects and illustrative embodiments of the present invention were prepared for testing using a five-gallon (18.9 liter) two-ply design. The outer layer of flexible bags has the following structure: thickness 3.8 mils (96.5 microns); symmetric; coextruded; seven-layer film with a layer of EVOH (44 mol.% ethylene) as a barrier central layer with a thickness of 2.5% to 5.0% of the barrier film (approximately 3.0 µm to 4.8 µm, and in some samples measurements identified as 3.3 µm). Thus, the EVOH layer constitutes approximately 3.4% (3.4% at 3.3 µm measured) and less than 5% of the total thickness of the outer barrier layer. The internal layer of flexible bags has the following structure: thickness 1.5 mils (38 microns); symmetric; coextruded; five-layer film without EVOH in the central layer. Tables 3 and 4 provide a general overview of formation structures that can be used in accordance with aspects and embodiments of the invention, as well as illustrative examples of embodiments of the invention.

Comparative example.

A comparative example of flexible pouches is manufactured using a two-ply design in which the outer barrier ply has the following structure: 3.8 mil (96.5 µm) thick; symmetric; coextruded; seven-layer film with a layer of EVOH (32 mol % ethylene) as a barrier center layer with a thickness of 2.5% to 5.0% of the barrier film thickness (approximately 3.0 µm to 4.8 µm in some measurements). Thus, the EVOH layer constitutes approximately 2.5% to 5.0% (eg, 3.6 µm/96 µm) of the total thickness of the outer layer.

The internal layer of the comparative flexible bags has the following structure: thickness 1.5 mils (38 microns); coextruded; five-layer film without EVOH in the central layer.

Below are the results of the Bruceton drop test of the bag, the goal of which was to achieve an F50 (median) drop value of 4 feet.

The flexible pouches of Example 1 unexpectedly demonstrate 57% and 29% improvement in pouch drop height in the Bruceton test compared to the control flexible pouch at 15°C and 24°C. In fact, Example 1's flexible bags achieve a target drop height of 4 feet.

The coextruded films of Comparative Example and Inventive Example 1 were compared to evaluate the flex crack resistance and stiffness of the outer (barrier) layer containing EVOH. The results are shown and summarized in Tables 6-6.1.

The above results indicate that the EVOH coextruded films of the invention have good or improved crack resistance when tested by Gelbo Flex compared to the comparative example, which may be due in part to the lower tensile modulus resulting in a more pliable, elastic film. For example, the film described herein may exhibit increased resistance to flex cracking (eg, about 35%) compared to a comparative (control) coextruded machine direction film. Likewise, in the transverse direction, films in accordance with the invention can improve resistance to flex cracking by approximately 22%. As for the 1% secant modulus of 1%, the elastic modulus of the films according to the invention decreased by about 12% in the longitudinal direction and by 15% in the transverse direction compared to the film of the comparative example.

These results are unexpected since the main difference in the two films arises from the introduction of a small amount (ie, a thin layer) of ethylene-rich EVOH into the central layer of the coextruded film. The structure and content of EVOH help improve the barrier properties of the film and also make bags or other materials made from the film more recyclable. Improvements in flexural modulus and secant modulus also result in superior shipping performance when filled bags are crated, palletized, and shipped to end-user locations.

EXPERIMENT 2

Performance characteristics of the flexible package.

In the following embodiments, the thickness of the outer and inner layers was varied to determine any effect on the performance of the Bruceton drop bag test and the performance of the structure as an oxygen barrier. Oxygen barrier performance was tested using MOCON according to ASTM D3985 protocol.

Example 2 of the invention

The outer layer of the flexible package in accordance with Example 2 of the invention has the following structure: thickness 3.8 mils (96.5 microns); symmetric; coextruded; seven-layer film with a layer of EVOH (44 mol.% ethylene) in the central layer, a thickness of 2.5% to 5.0% of the thickness of the barrier film (approximately 3.0-4.8 microns in some measurements). Thus, the EVOH layer constitutes approximately 2.5% to 5.0% (eg, 3.4% (100×(3.3 µm/96 µm)) of the total thickness of the outer layer.

The internal layer of flexible bags has the following structure: thickness 1.5 mils (38 microns); co-extruded without EVOH in the center layer. The thickness of the EVOH layer as a percentage of the total thickness of the two layers can be approximately calculated (for example, 2.4% (100×(3.3 μm/(96 μm+38 μm)))).

Example 3 of the invention

In Example 3 of the invention, the outer layer of the flexible bags has the following structure: thickness 3.8 mils (96.5 microns); symmetric; coextruded; seven-layer film with an EVOH (44 mol% ethylene) layer in the central layer, 2.5% to 5.0% of the barrier film thickness (approximately 3.0 µm to 4.8 µm in some measurements). Thus, the EVOH layer constitutes about 2.5% to 5.0% (eg, about 3.4% (100×(3.3 µm/96 µm))) of the total thickness of the outer layer.

The inner layer of Example 3 of the invention has the following structure: thickness 45 μm; co-extruded film structure without any central EVOH barrier layer. The EVOH layer thickness as a percentage of the total thickness of the two layers can be approximately calculated (eg 2.3% (100×(3.3 µm/(96 µm+45 µm)))).

Example 4 implementation of the invention

The outer layer in flexible bags according to Example 4 of the invention has the following structure: thickness 70 microns; symmetric; coextruded; seven-layer with an EVOH (44 mol% ethylene) layer in the central layer, 2.5% to 5.0% barrier film thickness (approximately 2.0 µm to 4.8 µm in some measurements). Thus, the EVOH layer is approximately 2.5 times the thickness of the outer layer.

The inner layer of Example 4 of the invention has the following structure: thickness 70 μm; co-extruded film structure without any central EVOH barrier layer. The thickness of the EVOH layer as a percentage of the total thickness of the two layers can be approximately calculated (for example, 1.7% (100×(2.4 μm/(70 μm+70 μm)))).

Example 5 of the invention

The outer layer in flexible bags according to Example 5 of the invention has the following structure: thickness 45 microns; symmetric; coextruded; seven-layer film with an EVOH (44 mol% ethylene) layer in the central layer, 2.5% to 5.0% of the barrier film thickness (approximately 1.5 µm to 4.8 µm in some measurements). Thus, the EVOH layer constitutes about 2.5% to 5.0% (eg, about 3.5% (100×(1.6 µm/45 µm))) of the total thickness of the outer layer.

The inner layer of Example 5 of the invention has the following structure: thickness 96 μm; co-extruded film structure without EVOH in the central layer. The thickness of the EVOH layer as a percentage of the total thickness of the two layers can be approximately calculated (for example, 1.1% (100×(1.6 μm/(45 μm+96 μm)))).

Example 6 (comparative/control).

The outer layer in flexible bags according to Example 6 has the following structure: thickness 96 microns; symmetric; coextruded; a seven-layer film with an EVOH (32 mol% ethylene) layer in the central layer, 2.5% to 5.0% thick of the barrier film (approximately 3.0 µm to 4.8 µm in some measurements). Thus, the EVOH layer constitutes about 2.5% to 5.0% (eg, about 3.4% (100×(3.3 µm/96 µm))) of the total thickness of the outer layer.

The internal layer of the flexible package has the following structure: thickness 38 microns; co-extruded film structure without any central EVOH barrier layer. The thickness of the EVOH layer as a percentage of the total thickness of the two layers can be approximately calculated (for example, 2.4% (100×(3.3 μm/(96 μm+38 μm)))).

Example 7 (comparative/control).

The outer layer of flexible bags according to Example 7 has the following structure: thickness 96 microns; symmetric; coextruded; seven-layer film with a layer of EVOH (32 mol % ethylene) in the central layer, 2.5% to 5.0% of the barrier film thickness (approximately 3.0 µm to 4.8 µm in some measurements). Thus, the EVOH layer constitutes about 2.5% to 5.0% (eg, about 3.4% (100×(3.3 µm/96 µm))) of the total thickness of the outer layer.

The internal layer of the flexible package has the following structure: thickness 45 microns; co-extruded film structure without any central EVOH barrier layer. The thickness of the EVOH layer as a percentage of the total thickness of the two layers can be approximately calculated (for example, 2.3% (100×(3.3 μm/(96 μm+45 μm)))).

Embodiments 3, 4, and 5 showed that varying the thickness of the outer and inner layers while maintaining the same overall thickness could maintain the required drop height of the F50 stack at 4.0 feet or higher. Reducing the internal non-barrier layer from 45 µm to 38 µm (options 2 and 3) kept the drop height above 4 feet. Reducing the thickness of the outer barrier layer and increasing the thickness of the inner non-barrier layer also reduces the total amount of EVOH in the structure from 2.4% to 1.1% (excluding closure). Therefore, depending on the maximum amount of EVOH allowed in the packaging for recycling purposes, the total amount of EVOH can be adjusted.

Comparative Examples 6 and 7 demonstrated a lower package drop height of less than 4 feet. These two comparative examples include a higher barrier grade of EVOH (with 32 mole percent ethylene) in the center layer, which is found in standard industrial applications. Although these Examples may exhibit better oxygen barrier performance than non-barrier films, pouch drop performance is compromised, likely due to the physical characteristics of the 32 mole percent ethylene grades, which are typically brittle. Thus, increasing oxygen impermeability simply increases manufacturing costs and surprisingly does not provide the resiliency, processability, and oxygen impermeability exhibited by the films and flexible pouches of the exemplary aspects and embodiments of the present invention illustrated by the description.

The oxygen barrier of a typical biaxially oriented nylon laminate as used in the industry for typical beverage pouches is approximately 3.6 cm ³ /100 in ² per day. These oxygen barrier data were obtained from a resulting 3.8 mil (96.5 µm) thermally laminate material with a 0.48 mil (12 µm) thick biaxially oriented nylon 6 core layer. The Examples show that the oxygen barrier value over the entire range of values for various Examples of implementation of the present invention is better than the comparative value for biaxial nylon. Therefore, the use of films in accordance with the illustrative embodiments described herein for the manufacture of flexible pouches can maintain shelf life without the need for higher EVOH barrier properties (lower OTR values). This also reduces costs.

EXPERIMENT 3

Comparison of films and bags with standard biaxially oriented nylon.

Containing two layers, five-gallon (18.9 liter) bags were made from films having the following structure: an outer layer (thicknesses of 1.8, 2.8 and 3.8 mils, corresponding to 46, 71 and 96.5 microns), consisting of seven coextruded layers with a central layer of EVOH (44 mol% ethylene) having a maximum thickness of 5% in the formation; and an inner layer (3.8, 2.8 and 1.8 mil thicknesses corresponding to 96.5, 71 and 46 microns) having five co-extruded layers containing no EVOH/barrier layer.

The five-gallon bags have an outside width of 18.75 inches (47.6 cm) and an outside length of 24.75 inches (62.9 cm) and were produced on the Maverick bag production line.

For comparison, a two-ply stack of standard biaxially oriented nylon was fabricated using the following ply structures: an outer layer of 3.8 mil (96.5 µm) biaxially oriented nylon laminate; and a 1.8 mil (46 µm) LLDPE inner layer.

The bags were evaluated using a drop test where ten bags of each type were dropped from a height of 30 inches (762 mm).

The bags were filled with water using Liqui-Box 1500 filler and kept for 16 hours at a constant temperature (73°F ambient and 40°F cold) before testing.

The total weight of the package was approximately 43 pounds (approximately 16 kg).

Each bag was dropped three times: the first time it was dropped onto the flat surface of the bag with the closure facing up, the second time it was dropped onto the bottom transverse seam of the bag, and the third time it was dropped onto the long seam of the bag.

This drop test data demonstrates that bags made in accordance with illustrative embodiments of the present invention have at least the same resiliency as bags made from standard biaxially oriented nylon material over a standard temperature range (ambient temperature and low temperatures) and with different thicknesses of barrier and non-barrier layers. This increased resilience for such pouch materials is unexpected and provides at least one or more of the following characteristics:

(a) reducing and/or limiting the amount of EVOH in the middle layer of the barrier layer to a maximum of 5% of the total film thickness, which is markedly different from most film structures containing EVOH, which typically include an amount of EVOH in the middle layer from 5% to 12%, and provides higher output stability and recyclability;

b) use of EVOH grades with a low oxygen barrier, i.e. having an ethylene content of from about 38 mol.% to about 48 mol.% (for example, 44 mol.%) which is markedly different from typical film structures produced by the EVOH blown process, which use an ethylene content of 29 mol.% or 32 mol.%, and provide improved barrier properties to oxygen;

(c) film structures that allow the thickness of the EVOH barrier layer in the outer barrier layer to be easily adjusted, as well as the thickness of the inner non-barrier layer to reduce the overall level of EVOH in the stack if desired or preferred, thereby reducing the total amount of EVOH in the entire stack structure ( excluding closure) is reduced to approximately 2.5% and only 1.1% of the thickness of the entire multi-layer structure.

(d) Films provide improved performance and recyclability compared to other films and pouch designs that use materials such as nylon, PET, or metal (such as vacuum deposition coating or aluminum foil).

Accordingly, embodiments described herein provide lower oxygen barrier films and pouches for end-use applications (e.g., bag-in-box packaging) for products having a shelf life of approximately six months or less, including, for example, , drinks and soft drinks, related additives (for example, syrups), edible oils, dairy products, etc. In such embodiments, the use of films for high-barrier bag-in-box packaging with long aseptic shelf life or hot fill packaging is generally avoided.

Claims (63)

1. Coextruded multilayer polymer barrier film comprising at least three layers: (i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer, while the inner sealing layer has a total density in the range from 0.910 g/cm ³ to 0.924 g/cm ³ ; (ii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer film, wherein the EVOH contains at least 38% ethylene in the EVOH copolymer; And (iii) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ . 2. The coextruded multilayer polymer barrier film of claim 1, wherein the inner seal layer and the outer seal layer contain an adhesive or bonding resin in an amount effective to improve adhesion of the seal layers to the central barrier layer. 3. Co-extruded multilayer polymer film, including three layers: (i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer, wherein the inner sealing layer has a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ ; (ii) first and second intermediate layers comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the first intermediate layer , and an adhesive or binder resin in an amount effective to promote adhesion of the first and second intermediate layers to at least one other layer in the coextruded multilayer polymer film, wherein the first and second intermediate layers have a combined density in the range of about 0.910 g/cm ³ to 0.924 g/ ^cm3 ; (iii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer film, wherein the EVOH contains at least 38% ethylene in the EVOH copolymer; And (iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ . 4. Coextruded multilayer polymer film according to claim 3, characterized in that the first intermediate layer is located between the inner sealing layer and the central barrier layer, and the second intermediate layer is located between the outer sealing layer and the central barrier layer. 5. Coextruded multilayer polymer film according to claim 3, characterized in that the interpolymer of ethylene and α-olefin in at least one of the inner sealing layer, the outer sealing layer, the first intermediate layer or the second intermediate layer contains a polymer fraction of linear low density polyethylene and a second copolymer fraction of ethylene-octene-1 copolymer, ethylene-hexene-1 copolymer or ethylene-butene-1 copolymer. 6. Co-extruded multilayer polymer film according to claim 5, characterized in that the interpolymer has a density of 0.915 g/cm ³ and a melt index from 0.80 dg/min to 1.0 dg/min. 7. Coextruded multilayer polymer film according to claim 3, characterized in that the ethylene-α-olefin interpolymer contains at least one metallocene linear low-density polyethylene (mLLDPE) having a density of 0.912 g/cm ³ . 8. Co-extruded multilayer polymer film according to claim 3, characterized in that the percentage by weight or thickness of the EVOH layer relative to the entire film is selected from the following values: 0.5, 0.6, 0.7, 0.8, 0 ,9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 , 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3 ,4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6 , 4.7, 4.8, 4.9, and 5.0. 9. Co-extruded multilayer polymer film according to claim 3, characterized in that the molar percentage of ethylene in the EVOH copolymer is selected from the following values: 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54 and 55. 10. The coextruded multilayer polymer film according to claim 3, characterized in that the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer or the second intermediate layer has a melt index in the range of 0. 2 to 2.0 dg/min. 11. The coextruded multilayer polymer film according to claim 3, wherein the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer or the second intermediate layer has a zero shear viscosity (ZSVR ) in the range from 1.15 to 2.5. 12. The coextruded multilayer polymer film according to claim 3, characterized in that the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer or the second intermediate layer has a molecular weight distribution expressed as the ratio of mass average molecular weight to number average molecular weight (Mw/Mn) in the range from 2.0 to 4.0. 13. Co-extruded multilayer polymer film, including seven layers: (i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer, wherein the inner sealing layer has a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ ; (ii) first and second outer intermediate layers and first and second inner intermediate layers, all intermediate layers containing an ethylene-α-olefin copolymer fraction having a density ranging from 0.894 g/cm ³ to 0.920 g/cm ³ , in an amount of at least about 50% by weight or thickness of the first intermediate layer, wherein all intermediate layers have a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ , and wherein the first and second inner intermediate layers contain an adhesive or binder resin in an amount effective to improve adhesion of the first and second inner intermediate layers to at least one layer of the coextruded multilayer polymer film; (iii) a central barrier layer adjacent to and located between the first and second inner intermediate layers, wherein the central barrier layer comprises ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer films, wherein EVOH contains at least 38% ethylene in the EVOH copolymer; And (iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ . 14. The coextruded multilayer polymer film according to claim 13, characterized in that the first intermediate layer is located between the inner sealing layer and the central barrier layer, and the second intermediate layer is located between the outer sealing layer and the central barrier layer. 15. The coextruded multilayer polymer film according to claim 13, characterized in that the interpolymer of ethylene and α-olefin in at least one of the inner sealing layer, the outer sealing layer, the first intermediate layer or the second intermediate layer contains a polymer fraction of linear low density polyethylene and a second copolymer fraction of ethylene-octene-1 copolymer, ethylene-hexene-1 copolymer or ethylene-butene-1 copolymer. 16. Co-extruded multilayer polymer film according to claim 15, characterized in that the interpolymer has a density of 0.915 g/cm ³ and a melt index from 0.80 dg/min to 1.0 dg/min. 17. The coextruded multilayer polymer film of claim 13, wherein the ethylene-α-olefin interpolymer contains at least one metallocene linear low density polyethylene (mLLDPE) having a density of 0.912 g/cm ³ . 18. Co-extruded multilayer polymer film according to claim 13, characterized in that the weight percentage or thickness of the EVOH layer relative to the entire film is selected from the following values: 0.5, 0.6, 0.7, 0.8, 0.9 , 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2 ,2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4 , 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4 .7, 4.8, 4.9, and 5.0. 19. Coextruded multilayer polymer film according to claim 13, characterized in that the molar percentage of ethylene in the EVOH copolymer is selected from the following values: 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54 and 55. 20. The coextruded multilayer polymer film according to claim 13, characterized in that the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer or the second intermediate layer has a melt index in the range of 0. 2 to 2.0 dg/min. 21. The coextruded multilayer polymer film of claim 13, wherein the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer, or the second intermediate layer has a zero shear rate viscosity (ZSVR ) in the range from 1.15 to 2.5. 22. The coextruded multilayer polymer film according to claim 13, wherein the ethylene-α-olefin interpolymer in at least one of the inner seal layer, the outer seal layer, the first intermediate layer or the second intermediate layer has a molecular weight distribution expressed as the ratio of mass average molecular weight to number average molecular weight (Mw/Mn) in the range from 2.0 to 4.0. 23. The coextruded multilayer polymer film of claim 3, wherein the at least one outer seal layer, the at least one inner seal layer, the central layer, the at least one first intermediate layer, and the at least one second intermediate layer separately comprise from one layer to 45 layers inclusive. 24. The coextruded multilayer polymer film of claim 13, wherein the at least one outer seal layer, the at least one inner seal layer, the central layer, the at least one first intermediate layer, and the at least one second intermediate layer individually comprise from one layer to 45 layers inclusive. 25. The coextruded multilayer polymer film of claim 3, wherein the total film thickness is from about 1 mil to about 5 mil, corresponding to about 25 microns to about 127 microns. 26. The coextruded multilayer polymer film of claim 13, wherein the total film thickness is from about 1 mil to about 5 mils, corresponding to about 25 microns to about 127 microns. 27. A fluid packaging pouch comprising a recyclable barrier coextruded multilayer polymer film and a non-barrier coextruded multilayer polymer film, wherein the barrier coextruded multilayer polymer film comprises: (i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer, wherein the inner sealing layer has a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ ; (ii) first and second intermediate layers comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the first intermediate layer layer, and an adhesive or binder resin in an amount effective to promote adhesion of the first and second intermediate layers to at least one other layer in the coextruded multilayer polymer film, wherein the first and second intermediate layers have a combined density in the range of about 0.910 g/ cm ³ to 0.924 g/cm ³ ; (iii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer film, or about 5% or less of the total weight or thickness of the barrier and non-barrier films wherein EVOH contains at least 38% ethylene in the EVOH copolymer; And (iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ . 28. A fluid packaging pouch comprising a recyclable barrier coextruded multilayer polymer film and a non-barrier coextruded multilayer polymer film, wherein the barrier coextruded multilayer polymer film comprises: (i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer, wherein the inner sealing layer has a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ ; (ii) first and second outer intermediate layers and first and second inner intermediate layers, all intermediate layers containing an ethylene-α-olefin copolymer fraction having a density ranging from 0.894 g/cm ³ to 0.920 g/cm ³ , in an amount of at least about 50% by weight or thickness of the first intermediate layer, wherein all intermediate layers have a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ , and wherein the first and second inner intermediate layers contain an adhesive or a binder resin in an amount effective to improve adhesion of the first and second inner intermediate layers to at least one layer of the coextruded multilayer polymer film; (iii) a central barrier layer adjacent to and located between the first and second inner intermediate layers, wherein the central barrier layer comprises ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer films, or about 5% or less of the total weight or thickness of the barrier and non-barrier films, wherein the EVOH contains at least 38% ethylene in the EVOH copolymer; And (iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ . 29. The pouch of claim 27, wherein the barrier film and non-barrier film each have a thickness of from about 1 mil to about 5 mil, corresponding to about 25 microns to 127 microns. 30. The pouch of claim 28, wherein the barrier film and non-barrier film each have a thickness of from about 1 mil to about 5 mil, corresponding to about 25 microns to 127 microns. 31. The package according to claim 27, characterized in that the thickness of the non-barrier film is greater than the thickness of the barrier film. 32. The package according to claim 28, characterized in that the thickness of the non-barrier film is greater than the thickness of the barrier film. 33. The pouch of claim 31, wherein the non-barrier film thickness is about 3.8 mils, which is about 96.5 microns, and the barrier film thickness is about 1.8 mils, which is about 46 microns. 34. The pouch of claim 32, wherein the non-barrier film thickness is approximately 3.8 mils, corresponding to approximately 96.5 microns, and the barrier film thickness is approximately 1.8 mils, corresponding to approximately 46 microns. 35. The package according to claim 27, characterized in that the EVOH layer in the barrier coextruded multilayer polymer film has a weight or thickness percentage relative to the entire film selected from the following values: 0.5, 0.6, 0.7, 0, 8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3, 3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 and 5.0. 36. The package according to claim 28, wherein the EVOH layer in the barrier coextruded multilayer polymer film has a weight or thickness percentage relative to the entire film selected from the following values: 0.5, 0.6, 0.7, 0, 8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3, 3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, and 5.0. 37. The pouch of claim 27, wherein the pouch is removable from about 95% to about 99.9% of its contents without the use of any extraction aid. 38. The pouch of claim 28, wherein the pouch is removable from about 95% to about 99.9% of its contents without the use of any extraction aid. 39. A pouch for packaging postmix syrup for mixing beverages, comprising at least one screw-on closure, a recyclable barrier coextruded multilayer polymer film, and a non-barrier coextruded multilayer polymer film, wherein the barrier coextruded multilayer polymer film contains: (i) an inner seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total inner seal layer, wherein the inner sealing layer has a total density in the range of from about 0.910 g/cm ³ to 0.924 g/cm ³ ; (ii) first and second intermediate layers comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the first intermediate layer , and an adhesive or binder resin in an amount effective to promote adhesion of the first and second intermediate layers to at least one other layer in the coextruded multilayer polymer film, wherein the first and second intermediate layers have a combined density in the range of about 0.910 g/cm ³ to 0.924 g/ ^cm3 ; (iii) a central barrier layer comprising ethylene vinyl alcohol (EVOH) comprising from about 0.1% to about 10% of the total weight or thickness of the coextruded multilayer polymer film, or about 5% or less of the total weight or thickness of the barrier and non-barrier films wherein EVOH contains at least 38% ethylene in the EVOH copolymer; And (iv) an outer seal layer comprising an ethylene-α-olefin copolymer fraction having a density in the range of 0.894 g/cm ³ to 0.920 g/cm ³ in an amount of at least about 50% by weight or thickness of the total outer seal layer, the outer sealing layer having a total density ranging from about 0.910 g/cm ³ to 0.924 g/cm ³ ; And the pouch passes the standard 40-inch (1016 mm) drop test when filled with postmix beverage mixing syrup.