Tubular sleeve

Abstract

The present disclosure provides a tubular sleeve comprising a polymeric first wall and a polymeric second wall, and a barrier film having one or more polyvinyl alcohol layers obtained by an extrusion process. The present disclosure provides a method of manufacturing a tubular sleeve. The present disclosure also provides a tubular sleeve comprising a polymeric first wall and a polymeric second wall, and a barrier film comprising one or more polyvinyl alcohol layers having a thickness in the range of from 1 micron to 15 microns.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to packaging materials. In particular, the present disclosure relates to a tubular sleeve comprising a barrier film, and a method of manufacturing said tubular sleeve. BACKGROUND

[0002] Tubular sleeves are layered laminates which have to meet several criteria such as layer integrity (meaning that the layers do not separate during their downstream processing (or) use phase), sufficient barrier properties to protect the product from several environmental factors such as oxygen, moisture, UV light, etc., and still maintain the product's aroma and stability, etc. A key challenge among these factors is to obtain sufficient barrier properties without increasing the thickness of the barrier layer and thus the overall sleeve. This is to enhance the sustainability of the tube to maximize the content of single material (single type of polymer) and minimize the barrier material, which is advantageous in terms of recyclability.

[0003] Therefore, there is an unmet need in the art to develop a multi-layered tubular sleeve having improved barrier properties at a minimal thickness, but still meeting the requirements of a tube sleeve properties such as compliance with burst strength, bonding strength with shoulder, mechanical integrity in drop test, no delamination during downstream processing or use phase, etc. SUMMARY

[0004] In one aspect of the present disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film having one or more polyvinyl alcohol layers obtained by an extrusion process.

[0005] In another aspect of the present disclosure, there is provided a method of manufacturing the tubular sleeve according to claim 1, the method comprising:

[0006] a) independently obtaining a polymeric first wall, a polymeric second wall, and a barrier film;

[0007] b) laminating the independent layers of the polymeric first wall, the polymeric second wall, and the barrier film together to obtain a laminated web; and

[0008] c) cutting the laminated web into a sheet having a width in the range of 63 mm to 320 mm, folding and sewing the sheet to obtain a tubular sleeve.

[0009] In yet another aspect of the present disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film comprising one or more polyvinyl alcohol layers having a thickness in the range of 1 micrometer to 15 micrometers.

[0010] In yet another aspect of the present disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film comprising a polyvinyl alcohol layer obtained by blown film extrusion of polyvinyl alcohol pellets.

[0011] These and other features, aspects, and advantages of the present inventive subject matter will become better understood with reference to the following disclosure and appended claims. The following Summary is provided as an overview of some aspects of the disclosure. It is not intended to determine key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter in any way. DETAILED DESCRIPTION

[0012] Those skilled in the art will realize that the subject matter of the present disclosure is susceptible to variations and modifications other than those specifically described. It is the intent of the disclosure to encompass all such variations and modifications as fall within the scope of the claims. The disclosure includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

[0013] DEFINITIONS

[0014] For the purposes of convenience and brevity, certain terms used in the description of the disclosure are defined herein before further describing the disclosure. These definitions should be read in light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for the convenience and completeness of the reader, particular terms and their meanings are set forth below.

[0015] The articles "a," "an," and "the" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By the use of the term "a" or "an," it is meant "one or more" of the elements following the article.

[0016] The terms "comprising" and "including" are used in the inclusive, open sense of "including but not limited to," and are used synonymously with the term "containing." The term "comprising" is used to mean one or more steps do not exclude additional steps.

[0017] Throughout this specification, unless the context requires otherwise, the word "comprise," and variations such as "comprises" and "comprising," will be understood to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps.

[0018] The term "including" is used to mean "including but not limited to." "Including" and "including but not limited to" are used interchangeably.

[0019] The term "w / w" means weight percent with respect to the weight of the total composition, unless otherwise stated.

[0020] The term "at least one" is used to mean one or more and thus includes individual components as well as mixtures / combinations.

[0021] The term "barrier film" refers to a polymeric layer having appreciable barrier properties at a reduced thickness and having a lower oxygen transmission rate when placed adjacent to another polymeric material. In the present disclosure, the barrier film has one or more layers of polyvinyl alcohol obtained through an extrusion process. The barrier film also includes one or more layers of ethylene vinyl alcohol copolymer, polyamide, polyethylene terephthalate, or a combination thereof.

[0022] The term "one or more layers of polyvinyl alcohol" as used herein refers to polyvinyl alcohol obtained through melt extrusion of particulate / pelletized polyvinyl alcohol. Polyvinyl alcohol exhibits good oxygen barrier properties due to its chemical nature.

[0023] The term "ethylene vinyl alcohol copolymer" as used herein refers to a hydrolyzed copolymer of ethylene and vinyl acetate used as a barrier compound in a layered laminate.

[0024] The term "polyamide" refers to a polymeric material having amide linkage linking groups obtained either by ring opening polymerization of caprolactam or by condensation reaction between amine and carboxyl groups of different monomer molecules, typically used in barrier applications in laminates. Polyamides also include copolymers and blends of aliphatic, aromatic.

[0025] The term "polyethylene terephthalate" refers to a polymeric resin belonging to the family of polyesters obtained by polymerization of terephthalic acid and derivatives of this type. Typically, polyethylene terephthalate is used as a barrier material due to its lower oxygen transmission rate. Polyethylene terephthalate can also be a low melting point PET having a melting point of (90 to 210) °C.

[0026] The term "blown film extrusion" refers to a process that includes extruding a molten polymer through an annular die and blowing to inflate the polymer to several times its original diameter, thereby forming a thin polymeric film bubble and collapsing the polymer bubble into a flat film, which is then converted into articles such as tubes, bags, covers, containers, and pouches.

[0027] The term "extrusion lamination" refers to a process in which two or more layers / films are joined together by a layer of molten resin extruded between the films. This layer of molten resin that joins the films together is referred to as a "adhesive layer".

[0028] The term "polymeric first wall" refers to a printable layer that can be configured with a print, a colorant, or any ink. Configuring the ink on the film is performed by employing a process selected from letterpress printing, flexo-ink printing, digital printing, or a combination thereof. For the purpose of printing, the polymeric first wall can be subjected to a corona treatment, oxidation, flame treatment, or plasma treatment. In the present disclosure, the polymeric first wall comprises at least one ethylene polymer selected from high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), metal-modified polyethylene, chemically-modified polyethylene, fiber-modified polyethylene, or a combination thereof.

[0029] The term "ethylene polymer" as used herein refers to a polymerized ethylene selected from high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and combinations thereof. The ethylene polymer of the present disclosure has a density in the range of 0.910 g / cm 3 to 0.99 g / cm 3 , preferably in the range of 0.940 g / cm 3 to 0.99 g / cm 3 , and a melt flow index in the range of 0.5 g / 10 minutes to 15.0 g / 10 minutes.

[0030] The term "melt flow index" as used herein refers to the amount of polymer in grams that flows through a capillary per 10 minutes. It is a measure of the ease of flow of a polymer melt, expressed in g / 10 minutes. It is performed according to ASTM D 1238.

[0031] The term "colorant" refers to a coloring substance added to the tubular sleeve to impart a desired color, thereby imparting an aesthetic look to the packaged article of the tubular sleeve. In the present disclosure, the colorant is selected from titanium dioxide (Ti02), zinc sulfide (ZnS2), zinc oxide (ZnO), barium sulfate (BaS04), calcium carbonate (CaC03), or a combination thereof.

[0032] Ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, the preferred methods and materials are now described.

[0034] The scope of the disclosure is not intended to be limited to the particular embodiments described herein, which are meant to be illustrative only. Functionally equivalent products, compositions, formulations, and methods are clearly within the scope of the disclosure as described herein.

[0035] As discussed in the background section, the tubular sleeve which is conventionally known for the layered laminated material has to meet several criteria such as layer integrity meaning the layers do not separate during its downstream processing (or) usage phase, sufficient barrier property to protect the product from environmental factors such as oxygen, moisture, UV light, etc., maintaining the aroma of the product, etc. The key challenge among these factors is to achieve sufficient barrier level without increasing the thickness of the barrier layer and hence the overall sleeve. This is to enhance the sustainability of the tube meaning maximizing the content of single material (single type of polymer) and minimizing the barrier material. The sustainability referred here is mainly from the perspective of mechanical recyclability.

[0036] Polyvinyl alcohol (PVOH) is one of the alternatives employed in the barrier layer to improve the barrier properties with minimal thickness. However, the major challenge associated with incorporating PVOH is its melt processability till date. On the other hand, if PVOH coating is applied, the residual moisture leads to peelability / delamination causing severe damage to the packaging material and the product inside it.

[0037] Thus, there is an unmet need in the prior art to develop a multilayered tubular sleeve having improved barrier properties at minimal thickness but still meeting the requirements of the tube sleeve properties such as meeting the burst strength, bonding strength with the shoulder, mechanical integrity in drop test, no delamination during the downstream processing or usage phase, etc.

[0038] To address these issues, the present disclosure provides a tubular sleeve comprising a barrier film having reduced thickness with improved barrier properties. The barrier film of the tubular sleeve comprises a polyvinyl alcohol layer obtained by melt extrusion of particulate polyvinyl alcohol. The melt extrusion process can be blown film or cast film. The barrier film can be further supplemented by one or more layers of other barrier components such as ethylene-vinyl alcohol copolymer, polyamide, polyethylene terephthalate or a combination thereof.

[0039] Accordingly, the present disclosure provides a tubular sleeve comprising a polymeric first wall and a polymeric second wall, and a barrier film having one or more polyvinyl alcohol layers obtained by an extrusion process. Depending on the position in the tubular sleeve, the polymeric first wall can also be referred to as outer wall, and the polymeric second wall can also be referred to as inner wall.

[0040] The present disclosure also provides a tubular sleeve comprising a polymeric first wall, a polymeric second wall and a barrier film having one or more polyvinyl alcohol layers obtained by an extrusion process. The polymeric first wall, the polymeric second wall and the barrier film can be placed alternately. Polymeric first (outer) wall / barrier film / polymeric second (inner) wall; barrier film / polymeric first wall / polymeric second (inner) wall; polymeric first (outer) wall / polymeric second wall / barrier film, etc. The core layer can be referred to as barrier film. The terms "core", "barrier film" and "core layer" can be used interchangeably.

[0041] Barrier film

[0042] A tubular sleeve according to one embodiment of the present disclosure comprises a polymeric first wall (polymeric outer wall) and a polymeric second wall (polymeric inner wall), and a barrier film having one or more polyvinyl alcohol layers obtained by an extrusion process. The core or barrier film as disclosed herein comprises one or more polyvinyl alcohol layers obtained by an extrusion process, in particular by blown film extrusion of polyvinyl alcohol pellets having dimensions typically adapted to the extrusion process. The core or barrier film is adjoined between the polymeric first wall and the polymeric second wall by at least one adhesive layer.

[0043] In one embodiment of the present disclosure, the barrier film is adjoined to the polymeric first wall or to the polymeric second wall, or sandwiched between the polymeric first wall and the polymeric second wall.

[0044] In one embodiment of the present disclosure, the barrier film is adjoined between the polymeric first wall and the polymeric second wall. In another embodiment of the present disclosure, the barrier film is adjoined between the polymeric first wall and the polymeric second wall by at least one adhesive layer.

[0045] In one embodiment of the present disclosure, the polymeric first wall is adjoined between the barrier film and the polymeric second wall. In another embodiment of the present disclosure, the polymeric first wall is adjoined between the barrier film and the polymeric second wall by at least one adhesive layer.

[0046] In one embodiment of the present disclosure, the polymeric second wall is adjoined between the barrier film and the polymeric first wall. In another embodiment of the present disclosure, the polymeric second wall is adjoined between the barrier film and the polymeric first wall by at least one adhesive layer.

[0047] In one embodiment of the disclosure, the barrier film is adjacent between the polymeric first wall and the polymeric second wall; or the polymeric first wall is adjacent between the barrier film and the polymeric second wall; or the polymeric second wall is adjacent between the barrier film and the polymeric first wall.

[0048] In one embodiment of the disclosure, the core (barrier film) has a single layer structure. Alternatively, in one embodiment of the disclosure, the core (barrier film) has a multi-layer structure. The polyvinyl alcohol layer has a thickness of less than 15 μιη. In another embodiment of the disclosure, the polyvinyl alcohol layer has a thickness in the range of 1 μιη to 15 μιη.

[0049] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein the barrier film is sandwiched between at least one first adhesive layer and at least one second adhesive layer; the first adhesive layer is in contact with the polymeric first wall; and the second adhesive layer is in contact with the polymeric second wall.

[0050] In another embodiment of the disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film having: one or more polyvinyl alcohol layers obtained by an extrusion process; one or more layers of ethylene-vinyl alcohol copolymer, polyamide, polyethylene terephthalate, or a combination thereof.

[0051] In another embodiment, there is provided a tubular sleeve as disclosed herein, wherein the barrier film comprises one or more polyvinyl alcohol layers obtained by an extrusion process, and one or more polyamide layers; the barrier film is adjacent to the polymeric first wall or to the polymeric second wall, or is sandwiched between the polymeric first wall and the polymeric second wall; the one or more polyvinyl alcohol layers are in contact with the first adhesive layer. In another embodiment, the barrier film comprises one or more polyvinyl alcohol layers obtained by an extrusion process, and one or more polyamide layers, wherein the barrier film is sandwiched between at least one first adhesive layer and at least one second adhesive layer, and the one or more polyamide layers are in contact with the first adhesive layer. In yet another embodiment, the barrier film comprises one or more polyvinyl alcohol layers obtained by an extrusion process, and one or more ethylene-vinyl alcohol copolymer layers, wherein the barrier film is sandwiched between at least one first adhesive layer and at least one second adhesive layer, and the one or more ethylene-vinyl alcohol copolymer layers are in contact with the first adhesive layer.

[0052] In one embodiment of the disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film comprising one or more polyvinyl alcohol layers obtained by an extrusion process disposed between polyamide layers.

[0053] In one embodiment of the disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film comprising one or more polyamide layers disposed between polyvinyl alcohol layers obtained by an extrusion process.

[0054] In one embodiment of the disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film comprising one or more ethylene-vinyl alcohol copolymer layers disposed between polyvinyl alcohol layers obtained by an extrusion process.

[0055] In one embodiment of the disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film comprising one or more polyamide layers disposed between one or more ethylene-vinyl alcohol copolymer layers obtained by an extrusion process.

[0056] In one embodiment of the disclosure, there is provided a tubular sleeve comprising: a polymeric first wall and a polymeric second wall, and a barrier film having one or more polyvinyl alcohol layers obtained by an extrusion process adjacent to one or more ethylene-vinyl alcohol copolymer layers.

[0057] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein when the barrier film is sandwiched between the polymeric first wall and the polymeric second wall, the barrier film is first sandwiched between the at least one first adhesive layer and the at least one second adhesive layer, and then sandwiched between the polymeric first wall and the polymeric second wall.

[0058] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein when the polymeric first wall is abutted between the barrier film and the polymeric second wall, the polymeric first wall is first sandwiched between the at least one first adhesive layer and the at least one second adhesive layer, and then sandwiched between the barrier film and the polymeric second wall.

[0059] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein when the polymeric second wall is abutted between the barrier film and the polymeric first wall, the polymeric second wall is first sandwiched between the at least one first adhesive layer and the at least one second adhesive layer, and then sandwiched between the barrier film and the polymeric first wall.

[0060] The total thickness of the barrier film as disclosed herein is in the range of 1 to 150 pm, with 1 to 11 layers. The barrier film layers can themselves comprise their own adhesive layers and other ethylene polymer layers.

[0061] Polymeric first wall

[0062] The tubular sleeve according to one embodiment of the disclosure includes a polymeric first wall. In one embodiment of the disclosure, the polymeric first wall includes at least one layer of an ethylene polymer. The at least one ethylene polymer has a melt mass-flow rate in the range of 0.5 g / 10 minutes to 15.0 g / 10 minutes, and a density in the range of 0.910 g / cm3to 0.990 g / cm3. 3 3

[0063] In one embodiment of the disclosure, the polymeric first wall is the outermost layer of the tubular sleeve, which is a printable layer having a printing property. In another embodiment of the disclosure, the polymeric first wall is an intermediate layer of the tubular sleeve. In another embodiment of the disclosure, the polymeric first wall is an inner layer of the tubular sleeve. In one embodiment, the polymeric first wall comprises at least one ethylene polymer selected from the group consisting of high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metal-modified polyethylene, chemically-modified polyethylene, fiber-modified polyethylene, or combinations thereof. In another embodiment, the polymeric first wall comprises at least one ethylene polymer selected from the group consisting of high density polyethylene (HDPE), medium density polyethylene (MDPE), LLDPE, LDPE, or combinations thereof.

[0064] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein the polymeric first wall includes at least one layer of an ethylene polymer. In another embodiment of the disclosure, the polymeric first wall includes a single layer of an ethylene polymer. In another embodiment of the disclosure, the polymeric first wall includes 2 to 7 layers of an ethylene polymer.

[0065] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein the polymeric first wall has a thickness in the range of 30 μm to 150 μm, with 1 to 7 layers. In another embodiment of the disclosure, the polymeric first wall includes at least 3 layers.

[0066] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein the polymeric first wall is in contact with at least one adhesive layer.

[0067] The polymeric first wall further comprises at least one colorant selected from the group consisting of titanium dioxide (Ti02), zinc sulfide (ZnS2), zinc oxide (ZnO), barium sulfate (BaS04), calcium carbonate (CaC03), or combinations thereof.

[0068] Adhesive layer ​​

[0069] The tubular sleeve according to one embodiment of the disclosure comprises at least one adhesive layer through which the barrier film, the polymeric first wall, and the polymeric second wall are adjoined together. The at least one adhesive layer can be selected from one or more layers of a modified or unmodified alkylene polymer. The term "modified or unmodified alkylene polymer" refers to a polymer comprising an alkyl chain optionally modified with a functional group or a substituent group and having a density in the range of 0.930 g / cm3 3 to 0.962 g / cm3 3 .

[0070] The one or more layers of a modified or unmodified alkylene polymer are selected from maleated polyethylene, anhydride grafted ethylene / 1-butene copolymer, anhydride grafted ethylene / 1-hexene copolymer, propylene ethylene copolymer), ethylene vinyl acetate copolymer, ethylene methyl acrylate copolymer, anhydride grafted ethylene / 1-octene copolymer, LDPE, LLDPE, HDPE, MDPE, or a combination thereof. When the barrier film is sandwiched between the polymeric first wall and the polymeric second wall, a first adhesive layer is present between the barrier film and the polymeric first wall, and a second adhesive layer is present between the barrier film and the polymeric second wall. A bottom surface of the first adhesive layer is in contact with an upper portion of the barrier film, and a top surface of the second adhesive layer is in contact with a lower portion of the barrier film. A top surface of the first adhesive layer is in contact with the polymeric first wall, and a bottom surface of the second adhesive layer is in contact with the polymeric second wall. When the polymeric first wall is sandwiched between the barrier film and the polymeric second wall, a first adhesive layer is present between the barrier film and the polymeric first wall, and a second adhesive layer is present between the polymeric first wall and the polymeric second wall. When the polymeric second wall is sandwiched between the barrier film and the polymeric first wall, a first adhesive layer is present between the barrier film and the polymeric second wall, and a second adhesive layer is present between the polymeric second wall and the polymeric first wall. The adhesive layer can be selected to maximize the compatibility with the polymeric first wall or the polymeric second wall thereon, and to maximize the adhesion between the polymeric first wall, the polymeric second wall, and the barrier film.

[0071] Polymeric second wall

[0072] The tubular sleeve according to one embodiment of the disclosure comprises a polymeric second wall. In one embodiment of the disclosure, the polymeric second wall is the innermost layer of the tubular sleeve, which is a sealant layer. In one embodiment of the disclosure, the polymeric second wall is an intermediate layer of the tubular sleeve. In one embodiment of the disclosure, the polymeric second wall comprises at least one ethylene polymer layer. The at least one ethylene polymer has a melt mass-flow rate in the range of 0.5 g / 10 minutes to 15.0 g / 10 minutes, and a density in the range of 0.910 g / cm33 to 0.990 g / cm 3 In one embodiment, the polymeric second (inner) wall comprises at least one ethylene polymer selected from the group consisting of high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metal modified polyethylene, chemically modified polyethylene, fiber modified polyethylene, or combinations thereof. In another embodiment, the polymeric second wall comprises at least one ethylene polymer selected from the group consisting of high density polyethylene (HDPE), medium density polyethylene (MDPE), LLDPE, LDPE, or combinations thereof.

[0073] In one embodiment of the present disclosure, there is provided a tubular sleeve as disclosed herein, wherein the polymeric second wall comprises at least one layer of an ethylene polymer. In another embodiment of the present disclosure, the polymeric second wall comprises a single layer of an ethylene polymer. In another embodiment of the present disclosure, the polymeric second wall comprises a plurality of layers of an ethylene polymer.

[0074] In one embodiment of the present disclosure, there is provided a tubular sleeve as disclosed herein, wherein the polymeric second wall has a thickness in the range of 30 μιη to 180 μιη with 1 to 7 layers.

[0075] In one embodiment of the present disclosure, there is provided a tubular sleeve as disclosed herein, wherein the polymeric second wall is in contact with at least one adhesive layer.

[0076] In one embodiment of the present disclosure, there is provided a tubular sleeve as disclosed herein, wherein the tubular sleeve has a density in the range of 0.935 g / cm 3 to 0.990 g / cm 3 .

[0077] In one embodiment of the present disclosure, there is provided a tubular sleeve comprising: a polymeric first wall having a thickness in the range of 30 μιη to 150 μιη with 1 to 7 layers of an ethylene polymer; a polymeric second wall having a thickness in the range of 30 μιη to 180 μιη with 1 to 7 layers of an ethylene polymer; and a barrier film having a thickness in the range of 1 μιη to 150 μιη with 1 to 11 layers of polyvinyl alcohol obtained by an extrusion process, one or more layers of ethylene-vinyl alcohol copolymer (EVOH), polyamide, polyethylene terephthalate, or combinations thereof.

[0078] In one embodiment of the present disclosure, there is provided a tubular sleeve as disclosed herein, wherein the tubular sleeve in the form of a tube withstands 2 bar pressure for 30 seconds.

[0079] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein the ellipticity of the tubular sleeve is in the range of 1% to 7%.

[0080] In one embodiment of the disclosure, there is provided a tubular sleeve as disclosed herein, wherein the thickness of the tubular sleeve is in the range of 61 μιη to 400 μιη.

[0081] In one embodiment of the disclosure, there is provided a method of manufacturing a tubular sleeve as disclosed herein, the method comprising: a) independently obtaining a polymeric first wall, a polymeric second wall and a barrier film; b) subsequently laminating the independent layers of the polymeric first wall, the polymeric second wall and the barrier film together to obtain a laminated web, cutting the laminated web into a sheet having a width in the range of 63 mm to 320 mm, and fold-seaming the sheet to obtain a tubular sleeve. In another embodiment of the disclosure, the lamination of the independent layers of the polymeric first wall, the polymeric second wall and the barrier film is by extrusion lamination. In yet another embodiment of the disclosure, the lamination of the independent layers of the polymeric first wall, the polymeric second wall and the barrier film is by adhesive lamination.

[0082] In one embodiment of the disclosure, there is provided a method of manufacturing a tubular sleeve as disclosed herein, wherein each of the layers of the polymeric outer (first) wall, the polymeric inner (second) wall and the barrier film is independently obtained by blown film extrusion. In another embodiment of the disclosure, each of the layers of the polymeric first (outer) wall, the polymeric second (inner) wall and the barrier film is independently obtained by downward extrusion. In another embodiment of the disclosure, each of the layers of the polymeric first wall, the polymeric second wall and the barrier film is independently obtained by melt casting.

[0083] While the subject matter has been described with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the disclosure should not be limited to the description of the embodiments contained herein.

[0084] Examples

[0085] The present disclosure will now be illustrated with running examples, which are intended to illustrate the running of the present disclosure and are not intended to limit the scope of the present disclosure in any way. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, exemplary methods, devices, and materials are described herein. It is to be understood that this disclosure is not limited to the particular methodology, and experimental conditions described, as such methods and conditions can vary.

[0086] Example 1

[0087] Process for making core / barrier film

[0088] The core / barrier film was obtained by blown film extrusion of granular polyvinyl alcohol having a particle size in the range of 1 mm to 15 mm. The granular polyvinyl alcohol was loaded into a hopper and fed into a hot barrel having a screw, where the granules were melt processed. The molten polyvinyl alcohol was then extruded through an annular die. The molten polymer was allowed to enter the die and air was injected through a hole in the center of the die to cause the molten polymer to expand radially into bubble form, which was subsequently drawn and cooled to obtain a polyvinyl alcohol layer having a thickness of less than 15 μιη. In another embodiment of the present disclosure, the thickness of the polyvinyl alcohol layer was in the range of 1 μιη to 15 μιη.

[0089] In another embodiment, a core-1 (barrier film) comprising a polyvinyl alcohol layer having a thickness of 5 μιη was obtained by a similar process. Similarly, a core-2 (barrier film) comprising a polyvinyl alcohol layer having a thickness of 3 μιη and a core-3 (barrier film) comprising a polyvinyl alcohol (PVOH) layer and an EVOH layer having a total thickness of 5 μιη were obtained. For comparison purposes, a core comprising only EVOH having a thickness of 15 μιη was also prepared.

[0090] Example 2

[0091] Preparation of tubular sleeve

[0092] The process for manufacturing the tubular sleeve comprises the following steps: forming layers and laminating the layers together to form a laminate, followed by cutting into a web of desired width (63 mm to 320 mm), and subsequently forming a tube (sleeve formation and shoulder formation) from the web.

[0093] The tubular sleeve comprises a polymeric outer wall and a polymeric inner wall layer, and a core comprising one or more polyvinyl alcohol layers obtained by an extrusion process. The polymeric outer wall and the polymeric inner wall are independently obtained by blown film extrusion of at least one ethylene polymer (PE). The core is prepared as described in Example 1.

[0094] Each of the layers is prepared by blown film extrusion as described above, and then laminated by extrusion or adhesive lamination to obtain a laminated web. The laminated web is then slit into a sheet having a width in the range of 63 mm to 320 mm and folded and sewn, followed by winding to obtain a tubular sleeve.

[0095] Tubular sleeves having different cores obtained by extrusion or adhesive lamination are shown in Table 1.

[0096] Table 1

[0097]

[0098] In one embodiment, a tubular sleeve having a thickness of 250 μm and a diameter of 35 mm and a length of 170 mm is prepared having a polymeric first wall having a thickness of 100 μm; a core comprising (5 μm) PVOH having a thickness of 50 μm; and a polymeric second (inner) wall having a thickness of 60 μm; and an adhesive layer of 20 μm. A comparative tubular sleeve is prepared having a polymeric first (outer) wall having a thickness of 100 μm; a core comprising (15 μm) EVOH having a thickness of 50 μm; and a polymeric second (inner) wall having a thickness of 60 μm; and an adhesive layer of 20 μm.

[0099] Example 3

[0100] Properties of the tubular sleeve

[0101] The tubular sleeves obtained in Example 2 are subjected to further mechanical and ovality measurements as listed in Table 2 below.

[0102] Table 2

[0103]

[0104] A. Burst strength analysis

[0105] Burst strength refers to the ability of a tube having a tubular sleeve of the present disclosure to withstand higher pressure at the nozzle for a specified period of time. The sleeve is held through its nozzle in a burst strength tester in a gas tight manner. The pressure is set to 2 bar and held for 30 seconds. The tubular sleeve is found to withstand this condition without rupturing within the 30 second period.

[0106] The burst strength test results show that the tubular sleeve prepared has the ability to withstand an internal pressure of about 2 bar without bursting.

[0107] B. Shoulder bond strength analysis

[0108] Shoulder bond strength refers to the adhesive strength between the shoulder of the tube and the sleeve. When the tube is pulled from the end of the sleeve (cut in a petal form) and the shoulder is in between, if the shoulder of the tube and the sleeve do not separate at the junction but the sleeve breaks, it indicates that the tube has good shoulder bond strength.

[0109] The tube was cut into 15 mm strips diagonally through the opposite side and tested for strength / separation behavior in a tensile machine / hand. The strips were found to tear without separating from the shoulder, which proves the shoulder bond strength and thus passes the test for shoulder bond strength.

[0110] C. Drop test:

[0111] The tube was filled with product and dropped from a height of 1.5 meters to check if it tears / cracks. After 3 drops, no leakage, cracks or tears were observed, which confirms that the tube passed the drop test and is stable enough. Table 3 below summarizes the test results of the tube comprising the tubular sleeve of the present disclosure and the tube comprising the comparative tubular sleeve of 15 pm EVOH as the core (CEx-1). From the table below, it can be inferred that the tubular sleeve of the present disclosure with less non-PE can enter the A recyclability class according to https: / / recyclass.eu / recyclability / definition.

[0112] Table 3

[0113]

[0114] Advantages of the present disclosure

[0115] The present disclosure provides a tubular sleeve comprising a core having one or more polyvinyl alcohol layers obtained by an extrusion process. The tubular sleeve of the present disclosure has very small ovality of less than 7% and still exhibits higher mechanical strength to withstand 2 bar pressure for 30 seconds. The tubular sleeve of the present disclosure has a thickness in the range of 61 pm to 400 pm and still passes the shoulder bond test and drop test. The present disclosure also provides a compatible yet economical extrusion process for preparing polyvinyl alcohol layers, one or more of which are used for the core of the tubular sleeve. The sleeve having polyvinyl alcohol in its core has better mechanical stability and still has desirable structural properties in terms of thickness and ovality.

Claims

1. A tubular sleeve comprising: A polymeric first wall and a polymeric second wall, and a barrier film having one or more polyvinyl alcohol layers obtained by an extrusion process.

2. The tubular sleeve of claim 1, wherein the polymeric first wall comprises at least one layer of an ethylene polymer.

3. The tubular sleeve of claim 1, wherein the polymeric second wall comprises at least one layer of an ethylene polymer.

4. The tubular sleeve of claim 1, wherein the barrier film further comprises one or more layers of an ethylene-vinyl alcohol copolymer, a polyamide, a polyethylene terephthalate, or a combination thereof.

5. The tubular sleeve of claim 1, wherein the tubular sleeve comprises at least one adhesive layer.

6. The tubular sleeve of claim 1, wherein the tubular sleeve has a density in the range of 0.935 grams / cm 3 to 0.990 grams / cm 3 .

7. The tubular sleeve of claim 1, wherein the polymeric first wall has a thickness in the range of 30 μm to 150 μm with 1 to 7 layers.

8. The tubular sleeve of claim 1, wherein the barrier film has a thickness in the range of 1 μm to 150 μm with 1 to 11 layers.

9. The tubular sleeve of claim 1, wherein the polymeric second wall has a thickness in the range of 30 μm to 180 μm with 1 to 7 layers.

10. The tubular sleeve of claim 5, wherein the adhesive layer is selected from one or more layers of a modified or unmodified alkylene polymer having a density in the range of 0.930 g / cm 3 to 0.962 g / cm 3 .

10. The tubular sleeve of claim 5, wherein the adhesive layer is selected from one or more layers of a modified or unmodified alkylene polymer having a density in the range of 0.930 g / cm 3 to 0.962 g / cm 3 .

11. The tubular sleeve according to any one of claims 2 or 3, wherein the at least one ethylene polymer layer has a melt mass-flow rate in the range of 0.5 g / 10 min to 15.0 g / 10 min, and a density in the range of 0.910 g / cm 3 to 0.990 g / cm 3 .

12. The tubular sleeve of claim 1, wherein the polymeric first wall further comprises at least one colorant.

13. The tubular sleeve of claim 12, wherein the colorant is selected from titanium dioxide (Ti02), zinc sulfide (ZnS2), zinc oxide (ZnO), barium sulfate (BaS04), calcium carbonate (CaC03), or a combination thereof.

14. The tubular sleeve of claim 1, wherein the tubular sleeve withstands 2 bar pressure for 30 seconds.

15. The tubular sleeve of claim 1, wherein the tubular sleeve has an ovality in the range of 1% to 7%.

16. The tubular sleeve of claim 1, wherein the tubular sleeve has a thickness in the range of 61 μm to 400 μm.

17. A method of manufacturing the tubular sleeve of claim 1, the method comprising: a. independently obtaining a polymeric first wall, a polymeric second wall, and a barrier film; b. laminating the independent layers of the polymeric first wall, the polymeric second wall, and the barrier film together to obtain a laminated web; and c. cutting the laminated web into a sheet having a width in the range of 63 mm to 320 mm and fold-seaming the sheet to obtain the tubular sleeve.

18. The method of claim 17, wherein the polymeric first wall, the polymeric second wall, and the barrier film are independently obtained by blown film extrusion, down extrusion, or melt casting.

19. The method of claim 17, wherein the lamination is by extrusion lamination or adhesive lamination. A polymeric first wall and a polymeric second wall, and a barrier film comprising one or more polyvinyl alcohol layers having a thickness in the range of 1 micrometer to 15 micrometers.

20. A tubular sleeve comprising:

20. The tubular sleeve of claim 19, wherein the polymeric first wall comprises at least one layer of an ethylene polymer.

21. The tubular sleeve of claim 19, wherein the polymeric second wall comprises at least one layer of an ethylene polymer.

22. The tubular sleeve of claim 19, wherein the barrier film further comprises one or more layers of an ethylene-vinyl alcohol copolymer, a polyamide, a polyethylene terephthalate, or a combination thereof.

23. The tubular sleeve of claim 19, wherein the tubular sleeve comprises at least one adhesive layer.

24. The tubular sleeve of claim 19, wherein the polymeric first wall has a thickness in the range of 30 μm to 150 μm with 1 to 7 layers.

25. The tubular sleeve of claim 19, wherein the barrier film has a thickness in the range of 1 μm to 150 μm with 1 to 11 layers.

26. The tubular sleeve of claim 19, wherein the polymeric second wall has a thickness in the range of 30 μm to 180 μm with 1 to 7 layers.

27. The tubular sleeve of claim 19, wherein the polymeric first wall further comprises at least one colorant.

28. The tubular sleeve of claim 27, wherein the colorant is selected from titanium dioxide (Ti02), zinc sulfide (ZnS2), zinc oxide (ZnO), barium sulfate (BaS04), calcium carbonate (CaC03), or a combination thereof.

29. The tubular sleeve of claim 19, wherein the tubular sleeve withstands 2 bar pressure for 30 seconds.

30. The tubular sleeve of claim 19, wherein the tubular sleeve has an ovality in the range of 1% to 7%.

31. The tubular sleeve of claim 19, wherein the tubular sleeve has a thickness in the range of 61 μm to 400 μm.

32. A method of manufacturing the tubular sleeve of claim 19, the method comprising: a. independently obtaining a polymeric first wall, a polymeric second wall, and a barrier film; b. laminating the independent layers of the polymeric first wall, the polymeric second wall, and the barrier film together to obtain a laminated web; and c. cutting the laminated web into a sheet having a width in the range of 63 mm to 320 mm and fold-seaming the sheet to obtain the tubular sleeve.

33. The method of claim 32, wherein the polymeric first wall, the polymeric second wall, and the barrier film are independently obtained by blown film extrusion, down extrusion, or melt casting.

34. The method of claim 32, wherein the lamination is by extrusion lamination or adhesive lamination.

21. A tubular sleeve comprising: Polymeric first wall and polymeric second wall, and a barrier film comprising a polyvinyl alcohol layer obtained by blown film extrusion of a particulate polyvinyl alcohol.

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