Recyclable bag

Abstract

Hermetically sealed single-lip pouch, comprising: a front wall, a rear wall, a first side wall, a second side wall, a top seal, a first side seal, a second side seal and a bottom seal, wherein the first side seal comprises an upper section connecting the front wall to the rear wall, a front leg section connecting the front wall to the first side wall, and a rear leg section connecting the rear wall to the first side wall, and the second side seal comprises an upper section connecting the front wall to the rear wall, a front leg section connecting the front wall to the second side wall, and a rear leg section connecting the rear wall to the second side wall, and wherein each of the front wall, the back wall, the first side wall and the second side wall is constructed from a recyclable packaging film with strong barrier properties, comprising a machine-direction oriented polyethylene-based outer film and a polyethylene-based inner film, wherein the polyethylene-based outer film has a secant modulus in the transverse direction and a secant modulus in the machine direction, each between 1,000 and 1,800 N / mm² 2 amount to, and wherein the recyclable packaging film with strong barrier properties comprises an ethylene vinyl alcohol copolymer not exceeding 5% by weight.

Description

TECHNICAL AREA

[0001] This disclosure concerns single-lip pouches and recyclable film structures with strong barrier properties used to manufacture the pouches. The hermetically sealed single-lip pouches offer product protection, easy opening functionality, and improved shelf life. STATE OF THE ART

[0002] Pre-made, single-lip pouches with strong barrier properties are manufactured using sophisticated flexible structures. These flexible structures typically incorporate a variety of films, layers, and materials to achieve the properties required for pouch production, filling, and distribution. The pouches often include numerous convenience features such as a flat bottom, an easy-open system, and a resealable mechanism. These single-lip pouches can be used to package various food products or other consumer goods.

[0003] The bag's format allows it to stand upright easily, providing large, flat areas for product information and marketing graphics. This format also enables a high fill volume for free-flowing products. However, it necessitates a complex bag manufacturing process due to the numerous triple seals where three or more bag walls meet. Achieving a good seal at these triple seals requires high temperatures to drive sufficient heat into the sealing layer. Consequently, the outer surface of the flexible structure typically uses high-temperature-resistant polymers, such as oriented polyester or oriented polyamide, while the inner surface typically uses low-temperature softening polymers, such as ethylene copolymers.This mixture of polymer materials results in a flexible structure and a bag that cannot be recycled in a single-polymer recycling stream. SUMMARY

[0004] The invention relates to hermetically sealed single-lip pouches made from a recyclable packaging film with strong barrier properties. The packaging film is designed so that the unfilled pouches can be produced in conventional pouch manufacturing equipment and the pouches can be filled and sealed in conventional filling equipment. When filled with dry product, the hermetically sealed pouches exhibit excellent drop resistance and product protection and offer easy opening and closing functionality.

[0005] The embodiments of the hermetically sealed single-lip bag have a front wall, a rear wall, a first side wall, a second side wall, a top seal, a first lateral seal, a second lateral seal, and a bottom seal. The first lateral seal has an upper section connecting the front wall to the rear wall, a front leg section connecting the front wall to the first side wall, and a rear leg section connecting the rear wall to the first side wall. Similarly, the second lateral seal has an upper section connecting the front wall to the rear wall, a front leg section connecting the front wall to the second side wall, and a rear leg section connecting the rear wall to the second side wall. In some embodiments, the bottom seal connects the front wall to the rear wall.In other embodiments, the single-lip bag further comprises a bottom wall, and the lower seal has a front section connecting the front wall to the bottom wall, a rear section connecting the rear wall to the bottom wall, a first lateral section connecting the first side wall to the bottom wall, and a second lateral section connecting the second side wall to the bottom wall.

[0006] In some embodiments of the single-lip bag, each of the front wall, back wall, first side wall, second side wall, and bottom wall (if present) is constructed from a recyclable packaging film with strong barrier properties, comprising a machine-oriented polyethylene-based outer film and a polyethylene-based inner film. The polyethylene-based outer film may have a transverse secant modulus and a machine-oriented secant modulus, each between 1,000 and 1,800 N / mm². 2 Ideally, the recyclable packaging film with strong barrier properties comprises an ethylene vinyl alcohol copolymer that does not exceed 5% by weight of the total composition.

[0007] The single-lip bag may have an adhesive layer that bonds the outer film to the inner film.

[0008] The recyclable packaging film with strong barrier properties may also contain a heat-resistant overprint varnish located on the exposed surface of the outer film.

[0009] In some embodiments of the single-lip pouch, the inner film of the recyclable, high-barrier packaging film can have a first outer layer comprising a sealing surface, a second outer layer, and a first inner layer, wherein the first inner layer of the inner film comprises the ethylene vinyl alcohol copolymer. The inner film can further contain a white pigment located in a second inner layer, the second inner layer of the inner film being positioned between the first inner layer of the inner film and the outer film. If the inner film contains a white pigment, the inner film preferably has a diffuse optical density between 0.30 and 0.50 units. The sealing surface of the inner film preferably has a dynamic coefficient of friction (COF) above 0.35, as measured according to ASTM 1894.

[0010] The hermetically sealed single-lip pouch can be made from a recyclable packaging film with strong barrier properties, enclosing an outer film consisting of one or more polyethylene-based polymers. In some embodiments, the outer film has a density between 0.93 g / cm³. 3 and 0.95 g / cm² 3 In some embodiments, the outer film exhibits a transverse elongation at break of more than 500% as measured according to ASTM D882. In some embodiments, the outer film exhibits a free shrinkage in the machine direction of less than 5% after heating an unstrained sample in an oven at 100°C for 15 minutes. In some embodiments, the outer film exhibits a free shrinkage in the machine direction of less than 3% after heating an unstrained sample in an oven at 100°C for 15 minutes.

[0011] The hermetically sealed single-lip bag may have a total composition comprising between 90% and 99% by weight of polyethylene-based polymer. Some embodiments of the hermetically sealed single-lip bag further include a zipper closure, a weakening line on the front wall extending between the upper portion of the first lateral seal and the upper portion of the second lateral seal, and / or a tear notch with a non-rounded internal shape, the tear notch being adjacent to the weakening line. The bag may have a second weakening line on the rear wall extending between the upper portion of the first lateral seal and the upper portion of the second lateral seal.

[0012] The hermetically sealed single-lip bag can contain a product, which can be a dry, particulate product. The product weight can range from 300 g to 10 kg. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The disclosure can be more fully understood by taking into account the following detailed description of various embodiments of the disclosure in conjunction with the accompanying drawings, in which: Fig. 1 is a schematic view of an embodiment of the hermetically sealed single-lip pouch; Fig. 2 is a schematic view of an embodiment of the hermetically sealed single-lip pouch; Fig. 3a is a schematic view of the upper section of an embodiment of the hermetically sealed single-lip bag; Fig. 3b is a schematic view of the upper section of an embodiment of the hermetically sealed single-lip bag, which has been partially opened; Fig. 4a is a schematic view of the tear notch detail on an embodiment of the hermetically sealed single-lip bag; Fig. 4b is a schematic view of the tear notch detail on an embodiment of the hermetically sealed single-lip bag; Fig. Figure 5 shows a cross-sectional view of an embodiment of the recyclable packaging film with strong barrier properties; and Fig. Figure 6 shows a cross-sectional view of an embodiment of the recyclable packaging film with strong barrier properties.

[0014] The drawings show some, but not all, embodiments. The elements depicted in the drawings are for illustrative purposes only and are not necessarily to scale, and the same (or similar) reference numerals denote the same (or similar) features in the drawings. DETAILED DESCRIPTION Introduction

[0015] Single-lip bags are used for packaging dry products that require significant environmental protection. These bags are made from packaging films with strong barrier properties that can be hermetically sealed. This effectively prevents ambient gases and moisture from penetrating the bag and negatively affecting the product inside after filling and sealing. Historically, packaging films with strong barrier properties incorporated several different polymer material types (i.e., combinations of polyester, polyamide, and polyolefin) to achieve the critical quality characteristics required for hermetically sealed single-lip bags. It is desirable to design a packaging film with strong barrier properties using a limited number of material types, focusing as much of the structure as possible on a single polymer type.In this way, the single-lip bag made from packaging film with strong barrier properties can be considered recyclable.

[0016] The focus of the single-lip pouches described here is to enable consumers to easily recycle the pouch in a polyethylene or polyolefin recycling stream, while maintaining the high-performance features that include hermetic seals and excellent robustness and durability.

[0017] The single-lip pouches described here contain high proportions of polyethylene-based polymers, exceeding 90% or even 95% by weight. The high-barrier packaging film used to manufacture these single-lip pouches also contains high proportions of polyethylene-based polymers, exceeding 90% or even 95% by weight. Other components of the single-lip pouches, such as zippers, may also contain high proportions of polyethylene-based polymers.

[0018] There are many competing characteristics for a packaging film with strong barrier properties for use in hermetically sealed, single-lip pouches. First, the film must have good heat resistance so that it is not affected or otherwise damaged by the strenuous pouch manufacturing process. Second, the film must allow for heat sealing, be able to seal the three-point sealing areas, and still remain strong after the seal is created. Third, the film must have good integrity to withstand drops and other misuse after filling and sealing. The details of these challenges are described below.Surprisingly and advantageously, it turned out that a packaging film with strong barrier properties, manufactured with a high proportion of polyethylene-based polymers and designed according to the characteristics described here, was able to achieve a balance between these characteristics and could be used to produce high-performance, hermetically sealed, single-lip pouches. Based on this finding, the pouch is suitable for use in packaging sensitive products and is, as desired, recyclable. Single-lip pouch

[0019] One embodiment of a single-lip bag 10, as described here, may have design features such as those described in Fig. Figure 1 shows the bag. It has a front wall 210, a back wall 220, a first side wall 230, a second side wall 240, and a bottom wall 250. Each wall is made of a recyclable packaging film with strong barrier properties. The walls can be made of the same recyclable packaging film with strong barrier properties (i.e., all walls are identical), or the walls can be made of different recyclable packaging films with strong barrier properties (i.e., the walls are made of more than one recyclable packaging film with strong barrier properties).

[0020] The walls of the single-lip bag 10 are connected by seals. The seals between the walls used here are heat seals produced by applying heat and pressure, as is known in the field. The front wall 210 and the back wall 220 are connected at or near the top of the bag by a top seal 340. The front wall 210 and the back wall 220 are also connected by an upper section 312 of a first lateral seal 310 and an upper section 322 of a second lateral seal 320. The first lateral seal 310 and the second lateral seal 320 extend from the top to the bottom of the bag 10. The first lateral seal 310 further includes a front leg section 314 that connects the front wall 210 to the first side wall 230, and a rear leg section 316 that connects the rear wall 220 to the first side wall 230.The first side wall 230 has a fold-like formation that terminates at a triple point of the first lateral seal 310, where the first side wall 230, the front wall 210, and the rear wall 220 meet. Similarly, the second lateral seal 320 further comprises a front leg section 324 that connects the front wall 210 to the second side wall 240, and a rear leg section 326 that connects the rear wall 220 to the second side wall 240. The second side wall 230 also has a fold-like formation that terminates at a triple point of the second lateral seal 320, where the second side wall 240, the front wall 210, and the rear wall 220 meet. To close the pocket, the bottom wall 250 is connected by a lower seal 330.The lower seal 330 has a front section 332 connecting the front wall 210 to the bottom wall 250, a rear section 334 connecting the rear wall 220 to the bottom wall 250, a first lateral section 336 connecting the first side wall 230 to the bottom wall 250, and a second lateral section 338 connecting the second side wall 240 to the bottom wall 250. Each section of the lower seal terminates at a triple point of the lower seal (i.e., four triple points, one at each corner of the bottom wall), where three of the walls meet.

[0021] Another embodiment of a single-lip bag 20, as described here, may have design features such as those described in Fig. 7 and Fig. Figure 8 shows the bag. It has a front wall 1210, a back wall 1220, a first side wall 1230, and a second side wall (not shown). Each wall is made of a recyclable packaging film with strong barrier properties. The walls can be made of the same recyclable packaging film with strong barrier properties (i.e., all walls are identical), or the walls can be made of different recyclable packaging films with strong barrier properties (i.e., the walls are made of more than one recyclable packaging film with strong barrier properties).

[0022] The walls of the single-lip bag 20 are connected by seals. The seals between the walls used here are heat seals produced by applying heat and pressure, as is known in the field. The front wall 1210 and the back wall 1220 are connected at or near the top of the bag by a top seal 1340. The front wall 1210 and the back wall 1220 are also connected by the upper section 1312 of a first lateral seal 1310 and an upper section (not shown) of a second lateral seal 1320. The first lateral seal 1310 and the second lateral seal 1320 extend from the top to the bottom of the bag 20.The first lateral seal 1310 further comprises a front leg section 1314, which connects the front wall 1210 to the first side wall 1230, and a rear leg section 1316, which connects the rear wall 1220 to the first side wall 1230. Thus, the first side wall 1230 has a fold-like formation that terminates at a triple point of the first lateral seal 1310, where the first side wall 1230, the front wall 1210, and the rear wall 1220 meet. Similarly, the second lateral seal 1320 further comprises a front leg section (not shown) that connects the front wall 1210 to the second side wall (not shown), and a rear leg section (not shown) that connects the rear wall 1220 to the second side wall (not shown).The second side wall has a fold-like formation that terminates at a triple point of the second lateral seal 1320, where the second side wall, the front wall 1210, and the rear wall 1220 meet. To complete the bag, the front wall 1210 is connected to the rear wall 1220 by a lower seal 1330.

[0023] The single-lip pouches described here can be used to package a wide variety of products, especially those sensitive to moisture, oxygen, and / or other gases. The pouches can be filled and hermetically sealed. A hermetically sealed single-lip pouch, as described here, exhibits no leaks in the seals, even at the three-point areas of the heat seals. In other words, the single-lip pouches are airtight. The recyclable packaging film with strong barrier properties maintains sufficient integrity, and the heat seals are designed to effectively insulate and protect the packaged product from the environment outside the pouch.

[0024] The single-lip pouches described here are suitable for packaging a wide variety of products. As in Fig. As shown in Figure 2, the hermetically sealed, single-lip pouch 10, constructed from walls of a recyclable packaging film 100 with strong barrier properties (which will be described in more detail here), contains a product 600 in an interior space. The products can be semi-moist or dry particulate matter that is sensitive to degradation of quality due to exposure to moisture and / or oxygen. Examples of products that can be packaged in the hermetically sealed, single-lip pouches include dry pet food, powdered milk, protein powder, dry beverage mixes, cocoa, rice, or other grains. The pouches can have a wide variety of dimensions (i.e., height, width, depth) but are generally able to stand upright when filled with product and often have a height greater than their width.The bags can be dimensioned to hold a product weighing from approximately 300 grams to approximately 10 kilograms.

[0025] Single-lip pouches are typically pre-fabricated in a process separate from filling and final sealing, meaning they are produced in dedicated pouch-making equipment. Pouch production utilizes one or more rolls of recyclable, barrier-resistant packaging film, with the walls mechanically formed and heat-sealed. Additional features, such as zippers and tear notches, can be added during the pouch manufacturing process.

[0026] The pre-made single-lip pouches are filled and sealed in filling machines commonly used in the field. The pouch is mechanically opened, a measured quantity of product is filled into the interior of the pouch, and a final seal (top seal 340) is applied, thus hermetically enclosing the product in the single-lip pouch.

[0027] The single-lip pouch can be manufactured with additional features and / or components. These features and / or components, such as tear lines, tear notches, and zippers, can facilitate easy opening and resealing of the pouch after initial opening, as described in [reference to product / document]. Fig. 3a and Fig. 3b shown, enable. Fig. 3a and Fig. Figure 3b shows schematic views of the upper section of an embodiment of the hermetically sealed single-lip bag 10. As shown, a zipper 400 can be incorporated, extending from the first side seal 310 to the second side seal 320. In bag manufacturing, the zipper is included in each of the side seals and is typically attached to both the front and back walls across the entire width of the bag. The zipper 400 can be manually opened and pressed to reseal, as is common with many types of packaging. The zipper component should be selected such that its composition consists of either 100% or nearly 100% of a polyethylene-based polymer, so as not to impair the bag's recyclability. The selection of the zipper should also take into account the need to create a hermetic seal around it.

[0028] The in Fig. 3a and Fig. The embodiments shown in Figure 3b also depict a weakening line 500 and a tear notch 502. In various embodiments, weakening lines and tear notches can be used together or independently. The weakening line 500 and / or the tear notch 502 are present to allow manual opening of the bag without the use of a tool, such as scissors. As shown in Fig. As shown in 3b, the upper seal 340 of the bag can be torn away from the rest of the bag at the point of the tear notch 502 or the weakening line 500, thereby breaking the hermetic seal of the bag and allowing access to the contents of the bag.

[0029] A weakening line 500 can be present in one or both of the front and back walls of the single-lip pouch. In some embodiments, the weakening line is formed mechanically. In other embodiments, the weakening line is formed by laser scoring (i.e., a weakening line scored by a laser). A weakening line can be continuous, extending from one side edge of the pouch to the other side edge of the pouch, or it can be interrupted. In some embodiments, there are multiple weakening lines in a single wall, running parallel to each other.

[0030] A particularly advantageous embodiment of a single-lip bag features a laser-scored weakening line in the front wall and a laser-scored weakening line in the back wall. Each of the laser-scored weakening lines extends across the front or back wall from the first lateral seal 310 to the second lateral seal 320. The laser scoring process used to generate the weakening lines can be applied (as described later) starting from the sealing surface side of the wall. This orientation when applying the weakening line has a significant influence on the tearing behavior. The weakening line is more effective, resulting in easier tearing. This will be explained in more detail in connection with the structure of the recyclable packaging film with strong barrier properties.

[0031] A tear notch 502 may be present in one or both of the first lateral seal 310 and the second lateral seal 320. If both are present, the tear notch 502 should be adjacent to the weakening line 500. In some embodiments, the inner shape of the tear notch 504 is rounded; an example of this is shown in Fig. 4a shown. In some embodiments, the inner shape of the tear notch 504 is not rounded, an example of which is shown in Fig. 4b shown.

[0032] As described herein, the "overall composition" of the single-lip bag refers to all components, including the walls, zipper, and all other additional components. The overall composition may contain between 90% and 99% by weight of polyethylene-based material. In some embodiments, the overall composition of the single-lip bag comprises more than 90% or more than 95% by weight of polyethylene-based material.

[0033] The term "polyethylene-based polymer," as used here, refers to a polymer that contains ethylene bonds and maintains a glass transition temperature below 50 °C. The polymer may be a homopolymer of ethylene or a copolymer of ethylene and other monomers. Examples of polyethylene-based polymers include, but are not limited to, low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLPDE), metallocene-catalyzed linear low-density polyethylene (mLLDPE), ethylene vinyl acetate copolymer (EVA), cyclic olefin copolymers (COC), and maleic anhydride-grafted polyethylene (MAH-PE). As used here, "polyethylene-based" does not include ethylene vinyl alcohol copolymers (EVOH), as this material is considered separately.

[0034] As used here, the term "polyethylene-based" refers to an article (i.e., a bag, film, layer, etc.) that contains high proportions of polyethylene-based polymers. In some cases, a polyethylene-based article contains at least 50% by weight of polyethylene-based polymers. Or a polyethylene-based article may contain at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, or at least 95% by weight of polyethylene-based polymers. In some cases, a polyethylene-based article is composed entirely of polyethylene-based polymers.

[0035] The recyclable, high-barrier packaging film used for the walls of the single-lip bag contains ethylene vinyl alcohol copolymer to enhance its gas barrier properties, as discussed later. The ethylene vinyl alcohol copolymer is not considered a polyethylene-based polymer, as described here, because it can cause problems in a polyethylene or polyolefin recycling stream. The overall composition of the single-lip bag contains less than 5% by weight, less than 4% by weight, or less than 3% by weight of ethylene vinyl alcohol copolymer. Some embodiments of the single-lip bag have an overall composition comprising between 1% by weight and 5% by weight of ethylene vinyl alcohol copolymer.

[0036] The hermetically sealed, single-lip pouches described here have the clear and surprising advantage of being recyclable in a polyethylene or polyolefin recycling stream. This advantage is achieved while maintaining a suitably hermetic packaging that offers excellent durability and drop resistance, and is easy to open. Recyclable packaging film with strong barrier properties

[0037] The single-lip pouches described here have walls made of a recyclable packaging film with strong barrier properties. The term "recyclable" reflects the fact that the material can be readily processed in a recycling process that accepts "full polyethylene" or "full polyolefin" articles. Typically, these recycling processes can handle small amounts of contaminant material. Therefore, "recyclable," as used here, refers to the fact that the packaging film has very high levels of polyethylene and low levels of acceptable contaminants. The overall composition, defined by the weight of the materials, determines the recyclability of the packaging film. As described here, the "overall composition" of the recyclable packaging film with strong barrier properties refers to all the materials it contains.The overall composition of the packaging film can contain between 90% and 99% by weight of polyethylene-based materials. In some embodiments, the overall composition of the recyclable packaging film with strong barrier properties comprises more than 90% or more than 95% by weight of polyethylene-based materials.

[0038] The recyclable packaging film with strong barrier properties can achieve an oxygen permeability rate of less than 1.0 cm. 3 / m 2 per day and bar or between 0.1 cm 3 / m 2 per day and bar and 1.5 cm 3 / m 2 per day and bar or between 0.5 cm 3 / m 2 per T a g and bar and 1.0 cm 3 / m 2per day and bar, measured at 23°C and 50% relative humidity using ASTM F1927. The recyclable packaging film with strong barrier properties can exhibit an oxygen permeability rate of less than 2.0 cm. 3 / m 2 per day and bar or between 0.5 cm 3 / m 2 per day and bar and 5.0 cm 3 / m 2 per day and bar or between 1.0 cm 3 / m 2 per day and bar and 2.0 cm 3 / m 2 per day and bar, measured at 23°C and 70% relative humidity using ASTM F1927. The recyclable packaging film with strong barrier properties can exhibit a moisture permeability rate of less than 1.0 g / m². 2 per day or between 0.1 g / m² 2 per day and 1.0 g / m² 2 per day or between 0.3 g / m² 2 per day and 1.0 g / m² 2per day, measured at 23 °C using ASTM F1249. The recyclable packaging film with strong barrier properties can exhibit a moisture permeability rate of less than 5.0 g / m². 2 per day or between 1.0 g / m² 2 per day and 5.0 g / m² 2 per day or between 1.5 g / m² 2 per day and 4.0 g / m² 2 per day, measured at 38 °C using ASTM F1249.

[0039] As previously mentioned, the recyclable packaging film with strong barrier properties contains ethylene vinyl alcohol copolymer, commonly referred to as EVOH, to reduce gas transmission. EVOH is also known as saponified or hydrolyzed ethylene vinyl acetate copolymer and refers to a vinyl alcohol copolymer containing an ethylene comonomer. EVOH is produced by the hydrolysis (or saponification) of an ethylene vinyl acetate copolymer. The degree of hydrolysis is preferably about 50 to 100 mol percent, more preferably about 85 to 100 mol percent, and most preferably at least 97 percent. It is well known that, for a highly effective oxygen barrier, the hydrolysis-saponification must be nearly complete, i.e., at least 97 percent. EVOH is commercially available in the form of resins with varying ethylene contents.Higher ethylene contents are expected to improve processability; however, gas permeability, particularly to oxygen, may become too high for certain packaging applications that are sensitive to microbial growth in the presence of oxygen. Conversely, lower ethylene contents may result in lower gas permeability, but processability may be more challenging. In some embodiments, the ethylene vinyl alcohol copolymer present in the recyclable, high-barrier packaging film comprises approximately 27–48 mol% ethylene. EVOH can be further optimized by blending, special copolymerization, or crosslinking to enhance heat resistance or other properties. The overall composition of the recyclable, high-barrier film can contain between 0.5 wt% and 5 wt% ethylene vinyl alcohol copolymer.In some embodiments, the overall composition of the recyclable film with strong barrier properties comprises less than 5 wt.% or less than 4 wt.% ethylene vinyl alcohol copolymer.

[0040] A "layer," as used here, is a homogeneous building block of film. Layers can be continuous or interrupted (i.e., patterned) with respect to the length and width of the film. The term "film," as used here, refers to a single- or multi-layered web that, compared to its dimensions in the x and y directions (length and width), has a negligible dimension in the z direction (thickness), similar to a sheet of paper. Films generally have two opposing principal surfaces that extend in the longitudinal and transverse directions. Films can be composed of an unlimited number of films and / or layers, with the films and / or layers bonded together to form a composite body, such as a wall.

[0041] As used here, the term "outer" is used to describe a film, layer, or surface located on or near the surrounding environment when the film is used in a packaging application. As used here, the term "inner" is used to describe a film, layer, or surface located on or near the packaged product when the film is used in a packaging application. The term "inner" here refers to a film or layer that is not on the surface of the film in which it is contained. An inner layer of a film is bordered on both sides by another layer of the same film. In other words, the layers of a film that are on the surface of that film are not inner layers.

[0042] One embodiment of the recyclable packaging film with strong barrier properties is in Fig. Figure 5 illustrates the recyclable packaging film 100 with strong barrier properties, which has a polyethylene-based outer film 110 oriented in the machine direction. When used to form a hermetically sealed single-lip bag, the outer film 110 is arranged so that it is in contact with the environment surrounding the packaging. The recyclable packaging film 100 with strong barrier properties also has a polyethylene-based inner film 120. When used to form a hermetically sealed single-lip bag, the inner film 120 is arranged so that it is in contact with the interior of the packaging and / or the product inside the packaging. The outer film 110 and the inner film 120 are joined together by any means known to a person skilled in the art of packaging film forming.

[0043] Another embodiment of the recyclable packaging film with strong barrier properties is in Fig.Figure 6 shows the packaging film 1100, which has an outer film 1110 and an inner film 1120 bonded together by an adhesive layer 1130. The outer film has an exposed surface 1112 and a lamination surface 1114. The inner film has a first outer layer 1122 with a sealing surface 1121 and a second outer layer 1128 with a lamination surface 1129. The inner film has a first inner layer 1124 and a second inner layer 1126. The first inner layer 1124 contains ethylene vinyl alcohol copolymer, and the second inner layer 1126 contains a white pigment. The second inner layer 1126 is located in a relatively outer position compared to the first inner layer 1124. In other words, the second inner layer 1126 lies between the first inner layer 1124 of the inner foil 1120 and the outer foil 1110.The recyclable packaging film 1100 with strong barrier properties also features a heat-resistant overprint varnish 1140, which is located on the exposed surface 1112 of the outer film 1110.

[0044] The terms "machine-oriented" and "MDO" mean that the film has been heated to a temperature lower than the material's melting point and stretched at least twice in the machine direction. This is typically achieved through an MDO process using heating rollers. While a typical blown film process will cause some stretching of the film, it will not be sufficient to qualify as oriented. An oriented film can also be heat-set (i.e., tempered) after orientation, making it dimensionally stable under elevated temperature conditions that might occur during film conversion (i.e., printing or laminating) or during the use of the packaging film (i.e., heat sealing). A film can be manufactured using special polymers and oriented under specific conditions that optimize the film's heat resistance.

[0045] The outer film of the recyclable, barrier-resistant packaging film is polyethylene-based. The outer film can consist of one or more polyethylene-based polymers. It can contain very high proportions of polyethylene-based polymers with only small amounts of non-polyethylene-based processing additives (i.e., antiblocking agents, slurries, etc.). The overall composition of the outer film can comprise between 90% and 99% by weight of polyethylene-based materials. In some embodiments, the overall composition of the outer film comprises more than 90% or more than 95% by weight of polyethylene-based material.

[0046] The outer film can be single-layered or multi-layered and can be produced by any known film forming process.

[0047] The outer film of the recyclable, high-barrier packaging film is oriented in the machine direction. Although the outer film is oriented, it is advantageous if, after heating an unstretched sample of the film in an oven at 100°C for 15 minutes, the film exhibits a free shrinkage in the machine direction of less than 5%, preferably less than 3%. Materials with higher shrinkage rates are detrimental when used in bag manufacturing because the shrinking film creates stresses in the heat-sealed areas adjacent to unsealed areas (the body of the walls). If the outer film of the recyclable, high-barrier packaging film exhibits low shrinkage under heating conditions, significantly less stress builds up in the transition areas between the seals and the unsealed wall sections.Lower stress in these areas results in less damage during drop testing and other improper handling.

[0048] The outer film of the recyclable packaging film with strong barrier properties can have a thickness of 10 to 100 micrometers, preferably 20 to 50 micrometers. The outer film can have a density of 0.92 g / cm³. 3 up to 0.98 g / cm³ 3 , preferably 0.93 g / cm³ 3 up to 0.95 g / cm³ 3 exhibit.

[0049] The outer film can exhibit a transverse elongation at break of more than 500% when tested according to ASTM D882. This level of elongation results in a more robust bag overall, capable of withstanding strong impacts such as drop tests.

[0050] Optionally, the exposed surface of the outer film is coated with a heat-resistant overprint varnish. The overprint varnish can cover the entire exposed surface of the outer film, or it can be textured. Preferably, this varnish layer is clear and very thin, so that the overall structure gains virtually no additional stiffness. Additionally, the outer film can be printed on one or both surfaces, with graphics provided for the film and the bag as a whole.

[0051] The inner film of the recyclable packaging film with strong barrier properties is polyethylene-based. The inner film can be multilayered and can contain one or more polyethylene-based polymers. The overall composition of the inner film can comprise between 90 wt.% and 99 wt.% polyethylene-based material. In some embodiments, the overall composition of the inner film comprises more than 90 wt.% or more than 95 wt.% polyethylene-based materials. The overall composition of the inner film can comprise between 0.5 wt.% and 5 wt.% ethylene vinyl alcohol copolymer. In some embodiments, the overall composition of the inner film comprises less than 5 wt.% or less than 4 wt.% ethylene vinyl alcohol copolymer.

[0052] As discussed, the inner film can have a first outer layer that forms the sealing surface. This layer is positioned closest to the inside of the packaging when the recyclable, high-barrier packaging film is formed into a single-lip pouch. The first outer layer contains polyethylene-based polymers that can achieve low heat-seal initiation temperatures for easy sealing and waterproofing of the pouch's triple points. Additionally, the sealing surface of the inner film should have a dynamic coefficient of friction (COF) above 0.35, as measured according to ASTM 1894.

[0053] As mentioned, the inner film may have a first inner layer containing ethylene vinyl alcohol copolymer.

[0054] As mentioned, the inner film can have a second, internal layer containing a white pigment. This white concentrate gives the bag an attractive appearance and a degree of opacity. The white concentrate can impart a diffuse optical density to the inner film between 0.30 and 0.50 units, as measured using a transmission densitometer.

[0055] As discussed, the inner film can have a second outer layer that creates the lamination surface.

[0056] The inner film may contain additional layers. The inner film should have a thickness of 25 to 200 micrometers, preferably 50 to 150 micrometers. Example

[0057] A recyclable film with strong barrier properties was produced by laminating a 25 micrometer thick polyethylene-based film (outer film) oriented in the machine direction (density of 0.94 g / cm³). 3) manufactured on a 120-micrometer thick blown polyethylene-based film (inner film) using a medium-strength polyurethane-based adhesive. The outer film exhibited a secant modulus in the machine direction of approximately 1,600 N / mm². 2 , a secant modulus in the transverse direction of approximately 1,100 N / mm 2and a transverse elongation at break of approximately 600%, measured according to ASTM D 882. The outer film, when stored unstretched in an oven at 100°C for 15 minutes, exhibited a free shrinkage of approximately 2.5% in the machine direction. The polyethylene-based inner film had a structure consisting of a laminating layer (i.e., second outer layer), a white pigment layer (i.e., second inner layer), a compound, an EVOH-containing layer (i.e., first inner layer), a compound, and a sealing layer (i.e., first outer layer), and a diffuse optical density of 0.41. The EVOH-containing layer was approximately 5 micrometers thick. The coefficient of friction (COF) of the inner film's sealing surface, measured according to ASTM 1894, was 0.46 (sealing surface to sealing surface, static) and 0.38 (sealing surface to sealing surface, dynamic).

[0058] The recyclable, barrier-resistant packaging film was formed into a single-lip bag with a front wall, back wall, first side wall, second side wall, and bottom wall, as described here. The bag also featured a zipper running across the top section, a laser-cut weakening line, and a triangular tear notch. The bag was filled with 4 kilograms of resin granules and sealed tightly, creating an airtight seal with no leaks at triple-point seals or zipper areas. The bag was dropped three times consecutively from a height of 1 meter without any damage (tearing or seal failure). The bag tore easily along the weakening line.

Claims

[1] Hermetically sealed single-lip pouch, comprising: a front wall, a rear wall, a first side wall, a second side wall, a top seal, a first side seal, a second side seal and a bottom seal, wherein the first side seal comprises an upper section connecting the front wall to the rear wall, a front leg section connecting the front wall to the first side wall, and a rear leg section connecting the rear wall to the first side wall, and the second side seal comprises an upper section connecting the front wall to the rear wall, a front leg section connecting the front wall to the second side wall, and a rear leg section connecting the rear wall to the second side wall, and wherein each of the front wall, the back wall, the first side wall and the second side wall is constructed from a recyclable packaging film with strong barrier properties, comprising a machine-direction oriented polyethylene-based outer film and a polyethylene-based inner film, wherein the polyethylene-based outer film has a secant modulus in the transverse direction and a secant modulus in the machine direction, each between 1,000 and 1,800 N / mm² 2 amount to, and wherein the recyclable packaging film with strong barrier properties comprises an ethylene vinyl alcohol copolymer not exceeding 5% by weight. [2] Hermetically sealed single-lip bag according to claim 1, further comprising a bottom wall made of a recyclable packaging film with strong barrier properties, wherein the bottom seal comprises a front section connecting the front wall to the bottom wall, a rear section connecting the rear wall to the bottom wall, a first lateral section connecting the first side wall to the bottom wall, and a second lateral section connecting the second side wall to the bottom wall. [3] Hermetically sealed single-lip bag according to claim 1, wherein the lower seal connects the front wall to the rear wall. [4] Hermetically sealed single-lip bag according to one of the preceding claims, further comprising an adhesive layer that bonds the outer film to the inner film. [5] Hermetically sealed single-lip bag according to one of the preceding claims, wherein the recyclable packaging film with strong barrier properties further comprises a heat-resistant overprint varnish arranged on the exposed surface of the outer film. [6] Hermetically sealed single-lip pouch according to any of the preceding claims, wherein the inner film comprises a first outer layer comprising a sealing surface, a second outer layer and a first inner layer, and wherein the first inner layer of the inner film comprises the ethylene vinyl alcohol copolymer. [7] Hermetically sealed single-lip pouch according to claim 6, wherein the inner film further comprises a white pigment arranged in a second inner layer, wherein the second inner layer of the inner film is arranged between the first inner layer of the inner film and the outer film, and wherein the inner film has a diffuse optical density between 0.30 and 0.50 units. [8] Hermetically sealed single-lip bag according to any of the preceding claims, wherein the sealing surface of the inner foil has a dynamic COF above 0.35, as measured by ASTM 1894. [9] Hermetically sealed single-lip bag according to any of the preceding claims, wherein the outer film consists of one or more polyethylene-based polymers. [10] Hermetically sealed single-lip bag according to one of the preceding claims, wherein the outer film has a density between 0.93 g / cm³ 3 and 0.95 g / cm²3 exhibits. [11] Hermetically sealed single-lip bag according to one of the preceding claims, wherein the outer film has a transverse elongation at break of more than 500% as measured according to ASTM D882. [12] Hermetically sealed single-lip bag according to one of the preceding claims, wherein the outer film exhibits a free shrinkage in the machine direction of less than 5% after heating an unstrained sample in an oven at 100°C for 15 minutes. [13] Hermetically sealed single-lip bag according to one of the preceding claims, wherein the outer film exhibits a free shrinkage in the machine direction of less than 3% after heating an unstrained sample in an oven at 100°C for 15 minutes. [14] Hermetically sealed single-lip pouch according to any of the preceding claims, further comprising an overall composition comprising between 90 wt.% and 99 wt.% polyethylene-based polymer. [15] Hermetically sealed single-lip pouch according to one of the preceding claims, further comprising a zipper closure. [16] Hermetically sealed single-lip bag according to one of the preceding claims, further comprising a weakening line on the front wall extending between the upper section of the first lateral seal and the upper section of the second lateral seal, and / or a tear notch with a non-rounded internal shape, wherein the tear notch is adjacent to the weakening line. [17] Hermetically sealed single-lip bag according to claim 16, further comprising a second weakening line on the rear wall extending between the upper section of the first lateral seal and the upper section of the second lateral seal. [18] Hermetically sealed single-lip bag according to one of the preceding claims, further comprising a product inside the bag, and the product being a dry particulate product. [19] Hermetically sealed single-lip bag according to a preceding claim, wherein the product has a total weight between 300 g and 10 kg.

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