Flexible Container with Peel Sleeve
20210300657 · 2021-09-30
Inventors
- Nicolas Cardoso Mazzola (Jundiai, BR)
- Jorge Caminero Gomes (Jundiai, BR)
- Javier Hector Figueyra (Buenos Aires, AR)
- Silvina Vanesa D'Agosto (Buenos Aires, AR)
Cpc classification
B32B2307/50
PERFORMING OPERATIONS; TRANSPORTING
B32B27/304
PERFORMING OPERATIONS; TRANSPORTING
B29C65/02
PERFORMING OPERATIONS; TRANSPORTING
B29K2067/003
PERFORMING OPERATIONS; TRANSPORTING
B29C65/76
PERFORMING OPERATIONS; TRANSPORTING
B32B2307/40
PERFORMING OPERATIONS; TRANSPORTING
B32B7/12
PERFORMING OPERATIONS; TRANSPORTING
B29C66/21
PERFORMING OPERATIONS; TRANSPORTING
B29C66/73713
PERFORMING OPERATIONS; TRANSPORTING
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B29K2023/0633
PERFORMING OPERATIONS; TRANSPORTING
B32B27/18
PERFORMING OPERATIONS; TRANSPORTING
B29K2023/0625
PERFORMING OPERATIONS; TRANSPORTING
B29K2023/0625
PERFORMING OPERATIONS; TRANSPORTING
B29C66/5326
PERFORMING OPERATIONS; TRANSPORTING
B32B2307/546
PERFORMING OPERATIONS; TRANSPORTING
B29C66/028
PERFORMING OPERATIONS; TRANSPORTING
B65D75/26
PERFORMING OPERATIONS; TRANSPORTING
B65D75/008
PERFORMING OPERATIONS; TRANSPORTING
B29C66/712
PERFORMING OPERATIONS; TRANSPORTING
B32B2307/714
PERFORMING OPERATIONS; TRANSPORTING
B29L2031/712
PERFORMING OPERATIONS; TRANSPORTING
B32B27/306
PERFORMING OPERATIONS; TRANSPORTING
B29K2067/003
PERFORMING OPERATIONS; TRANSPORTING
B29K2023/0633
PERFORMING OPERATIONS; TRANSPORTING
B29C66/1122
PERFORMING OPERATIONS; TRANSPORTING
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B32B15/20
PERFORMING OPERATIONS; TRANSPORTING
B29C65/482
PERFORMING OPERATIONS; TRANSPORTING
B32B27/20
PERFORMING OPERATIONS; TRANSPORTING
International classification
B65D75/58
PERFORMING OPERATIONS; TRANSPORTING
B32B15/20
PERFORMING OPERATIONS; TRANSPORTING
B32B7/12
PERFORMING OPERATIONS; TRANSPORTING
B65D75/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The present invention relates to a flexible container (10). In an embodiment, the flexible container includes a first flexible film (12) superimposed on an opposing second flexible film (14). The first flexible film and the second flexible film are sealed along a common peripheral edge (16) to form an inner container having a closed chamber. The first flexible film and the second flexible film each has an outermost layer comprising an ethylene-based polymer. Each outermost layer is a surface-treated layer having a surface energy from 33 mN/m to 36 mN/m. The flexible container includes a peel sleeve (22, 24) superimposed on each respective outermost layer and along the common peripheral edge. The flexible container includes a release material (26) located between the peel sleeve and each outermost layer along the common peripheral edge. The release material releasably attaches the peel sleeve to the inner container.
Claims
1. A flexible container comprising: a first flexible film superimposed on an opposing second flexible film, the first flexible film and the second flexible film sealed along a common peripheral edge to form an inner container having a closed chamber; the first flexible film and the second flexible film each having an outermost layer comprising an ethylene-based polymer, and each outermost layer is a surface-treated layer having a surface energy from 33 mN/m to 36 mN/m; a peel sleeve superimposed on each respective outermost layer and along the common peripheral edge; and a release material located between the peel sleeve and each outermost layer along the common peripheral edge; the release material releasably attaching the peel sleeve to the inner container.
2. The flexible container of claim 1 wherein the release material is located in a spaced-apart manner along a portion of the common peripheral edge and between the peel sleeve and each outermost layer.
3. The flexible container of claim 1 wherein each peel sleeve comprises a tab at a top portion of the flexible container, each tab free of release material.
4. The flexible container of claim 1 wherein the inner container comprises a top heat seal at a top portion of the flexible container.
5. The flexible container of claim 4 wherein the top heat seal is sandwiched by the tabs.
6. The flexible container of claim 3 wherein the top heat seal and the tabs are free of the release material.
7. The flexible container of claim 3 wherein at least one tab has a free edge for grasping and initiating peel sleeve release.
8. The flexible container of claim 1 wherein the release material adheres each peel sleeve to its respective surface-treated layer with a bond strength from 0.00656 N/mm to 0.00386 N/mm.
9. The flexible container of claim 1 wherein the release material adheres to the peel sleeve when the peel sleeve is released from its respective surface-treated layer.
10. The flexible container of claim 1 comprising an access member located at a bottom portion of the top heat seal.
11. The flexible container of claim 10 wherein the access member is selected from the group consisting of a tear notch, a tear slit, a perforation, a line of weakness, a cut line, and combinations thereof.
12. The flexible container of claim 10 comprising an accessory structure located below the access member.
13. The flexible container of claim 12 wherein the accessory structure is selected from the group consisting of a re-seal structure, a microcapillary strip, and combinations thereof, comprising an accessory structure located below the access member.
14. The flexible container of claim 1 wherein the release material is a GRAS acrylate-based composition.
15. The flexible container of claim 1 wherein each peel sleeve is composed of a material selected from the group consisting of polyethylene terephthalate and biaxially oriented polypropylene.
16. The flexible container of claim 1 wherein the flexible container is selected from the group consisting of a pouch, a pillow pouch, a stand up pouch, and a fin seal pouch.
17. The flexible container of claim 1 comprising a comestible in the chamber.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0004]
[0005]
[0006]
[0007]
[0008]
[0009]
[0010]
[0011]
DEFINITIONS AND TEST METHODS
[0012] All references to the Periodic Table of the Elements herein shall refer to the Periodic Table of the Elements, published and copyrighted by CRC Press, Inc., 2003. Also, any references to a Group or Groups shall be to the Groups or Groups reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups. Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight. For purposes of United States patent practice, the contents of any patent, patent application, or publication referenced herein are hereby incorporated by reference in their entirety (or the equivalent US version thereof is so incorporated by reference), especially with respect to the disclosure of synthetic techniques, definitions (to the extent not inconsistent with any definitions provided herein) and general knowledge in the art.
[0013] The numerical ranges disclosed herein include all values from, and including, the lower value and the upper value. For ranges containing explicit values (e.g., 1, or 2, or 3 to 5, or 6, or 7) any subrange between any two explicit values is included (e.g., 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6; etc.).
[0014] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight, and all test methods are current as of the filing date of this disclosure.
[0015] The term “bond strength” is the amount of force or energy required to separate plies of material or materials plus the force to bend the plies. Ply separation is initially started mechanically by the application of heat or by using a solvent. The separated plies of the test specimen are then placed into the grips of a tensile testing machine. The grips are then separated and the force required to further separate the plies is defined as bond strength. Bond strength is measured in accordance with ASTM F 904, and is reported in Newtons per millimeter, or N/mm.
[0016] The term “composition,” as used herein, refers to a mixture of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.
[0017] The terms “comprising,” “including,” “having,” and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term “comprising” may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term, “consisting essentially of” excludes from the scope of any succeeding recitation any other component, step or procedure, excepting those that are not essential to operability. The term “consisting of” excludes any component, step or procedure not specifically delineated or listed.
[0018] Density is measured in accordance with ASTM D 792 with results reported in grams (g) per cubic centimeter (cc), or g/cc.
[0019] An “ethylene-based polymer,” as used herein is a polymer that contains more than 50 mole percent polymerized ethylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer.
[0020] Melt flow rate (MFR) is measured in accordance with ASTM D 1238, Condition 280° C./2.16 kg (g/10 minutes).
[0021] Melt index (MI) is measured in accordance with ASTM D 1238, Condition 190° C./2.16 kg (g/10 minutes).
[0022] Tm or “melting point” as used herein (also referred to as a melting peak in reference to the shape of the plotted DSC curve) is typically measured by the DSC (Differential Scanning calorimetry) technique for measuring the melting points or peaks of polyolefins as described in U.S. Pat. No. 5,783,638. It should be noted that many blends comprising two or more polyolefins will have more than one melting point or peak, many individual polyolefins will comprise only one melting point or peak.
[0023] An “olefin-based polymer,” as used herein is a polymer that contains more than 50 mole percent polymerized olefin monomer (based on total amount of polymerizable monomers), and optionally, may contain at least one comonomer. Nonlimiting examples of olefin-based polymer include ethylene-based polymer and propylene-based polymer.
[0024] A “polymer” is a compound prepared by polymerizing monomers, whether of the same or a different type, that in polymerized form provide the multiple and/or repeating “units” or “mer units” that make up a polymer. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term copolymer, usually employed to refer to polymers prepared from at least two types of monomers. It also embraces all forms of copolymer, e.g., random, block, etc. The terms “ethylene/α-olefin polymer” and “propylene/α-olefin polymer” are indicative of copolymer as described above prepared from polymerizing ethylene or propylene respectively and one or more additional, polymerizable α-olefin monomer. It is noted that although a polymer is often referred to as being “made of” one or more specified monomers, “based on” a specified monomer or monomer type, “containing” a specified monomer content, or the like, in this context the term “monomer” is understood to be referring to the polymerized remnant of the specified monomer and not to the unpolymerized species. In general, polymers herein are referred to has being based on “units” that are the polymerized form of a corresponding monomer.
[0025] A “propylene-based polymer” is a polymer that contains more than 50 mole percent polymerized propylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer.
[0026] The term “surface energy” is the sum of all intermolecular forces that are on the surface of a material, the degree of attraction or repulsion force of a material surface exerts on another material. Surface energy is measured in accordance with ASTM D 2578 and is reported in milli-Newtons/meter, or mN/m.
DETAILED DESCRIPTION
[0027] The present disclosure is directed to a flexible container. In an embodiment, the flexible container includes a first flexible film superimposed on an opposing second flexible film. The first flexible film and the second flexible film are sealed along a common peripheral edge to form an inner container having a closed chamber. The first flexible film and the second flexible film each has an outermost layer composed of an ethylene-based polymer. Each outermost layer is a surface-treated layer having a surface energy from 33 mN/m to 36 mN/m. The flexible container includes a peel sleeve superimposed on each respective outermost layer and along the common peripheral edge. The flexible container includes a release material located between the peel sleeve and each outermost layer along the common peripheral edge. The release material releasably attaches the peel sleeve to the inner container.
1. Flexible Films
[0028] The present flexible container includes a first flexible film superimposed on an opposing second flexible film so as to define a common peripheral edge. The first flexible film and the second flexible film may be separate and discrete films with respect to each other. Alternatively, the first flexible film and the second flexible film each may be a component (i.e., panels) of a single unitary film that is folded over along one of the sides of the flexible container, such as a fold-over bottom pouch, for example. A “fold-over bottom pouch” is a flexible pouch made from a single flexible film with seals on three sides and the single flexible film is folded over on the bottom.
[0029] The present flexible container includes a first flexible film and a second flexible film. Each film is flexible and has from one, or two to three, or four, or five, or six, or seven, or eight, or nine, or 10 layers. The first flexible film and the second flexible film each is resilient, flexible, deformable, and pliable. The structure and composition for each flexible film may be the same or different. For example, each of two opposing flexible films can be made from a separate web, each web having a unique structure and/or unique composition, finish, or print. Alternatively, each flexible film can be the same structure and the same composition.
[0030] In an embodiment, the first flexible film and the second flexible film each is a flexible multilayer film having the same structure and the same composition.
[0031] Each flexible multilayer film may be (i) a coextruded multilayer structure, (ii) a laminate, or (iii) a combination of (i) and (ii). In an embodiment, each flexible multilayer film has at least three layers: a seal layer, an outer layer, and a core layer and/or a tie layer between. The tie layer adjoins the seal layer to the outer layer. The flexible multilayer film may include one or more optional inner layers disposed between the seal layer and the outer layer.
[0032] In an embodiment, the flexible multilayer film is a coextruded film having at least two, or three, or four, or five, or six, or seven to eight, or nine, or 10, or 11, or more layers. Some methods, for example, used to construct films are by cast co-extrusion or blown co-extrusion methods, adhesive lamination, extrusion lamination, thermal lamination, and coatings such as vapor deposition. Combinations of these methods are also possible. Film layers can comprise, in addition to the polymeric materials, additives such as stabilizers, slip additives, antiblocking additives, process aids, clarifiers, nucleators, pigments or colorants, fillers and reinforcing agents, and the like as commonly used in the packaging industry. It is particularly useful to choose additives and polymeric materials that have suitable organoleptic and or optical properties.
[0033] Nonlimiting examples of suitable polymeric materials for the seal layer and/or the core layer and/or the outer layer include olefin-based polymer (including any ethylene/C.sub.3-C.sub.10 α-olefin copolymers linear or branched), propylene-based polymer (including plastomer and elastomer, random propylene copolymer, propylene homopolymer, and propylene impact copolymer), ethylene-based polymer (including plastomer and elastomer, high density polyethylene (“HDPE”), low density polyethylene (“LDPE”), linear low density polyethylene (“LLDPE”), medium density polyethylene (“MDPE”), ethylene-acrylic acid or ethylene-methacrylic acid and their ionomers with zinc, sodium, lithium, potassium, magnesium salts, ethylene vinyl acetate copolymers and blends thereof.
[0034] Nonlimiting examples of suitable polymeric materials for the tie layer include functionalized ethylene-based polymers such as ethylene-vinyl acetate (“EVA”), polymers with maleic anhydride-grafted to polyolefins such as any polyethylene, ethylene-copolymers, or polypropylene, and ethylene acrylate copolymers such an ethylene methyl acrylate (“EMA”), glycidyl containing ethylene copolymers, propylene and ethylene based olefin block copolymers (OBC) such as INTUNE™ (propylene-based olefin block copolymer) and INFUSE™ (olefin block copolymer) both available from The Dow Chemical Company, and blends thereof.
[0035] The flexible multilayer film may include additional layers which may contribute to the structural integrity or provide specific properties. The additional layers may be added by direct means or by using appropriate tie layers to the adjacent polymer layers. Polymers which may provide additional mechanical/optical performance such as stiffness or opacity, as well polymers which may offer gas barrier properties or chemical resistance can be added to the structure.
[0036] Nonlimiting examples of suitable material for the optional barrier layer include copolymers of vinylidene chloride and methyl acrylate, methyl methacrylate or vinyl chloride (e.g., SARAN™ resins available from The Dow Chemical Company); vinylethylene vinyl alcohol (EVOH), metal foil (such as aluminum foil). Alternatively, modified polymeric films such as vapor deposited aluminum or silicon oxide on such films as BON, OPET, or OPP, can be used to obtain barrier properties when used in laminate multilayer film.
[0037] In an embodiment, the flexible multilayer film includes a seal layer selected from LLDPE (sold under the trade name DOWLEX™ (The Dow Chemical Company)), single-site LLDPE (substantially linear, or linear, olefin polymers, including polymers sold under the trade name AFFINITY™ or ELITE′″ (The Dow Chemical Company) for example, ethylene vinyl acetate (EVA), ethylene ethyl acrylate (EEA), propylene-based plastomers or elastomers such as VERSIFY™ (The Dow Chemical Company), grafted olefin-based polymer (MAH-grafted), and blends thereof. An optional tie layer is selected from either olefin block copolymer (sold as INFUSE™) or propylene-based olefin block copolymer (INTUNE™). The outer layer includes greater than 50 wt % of resin(s) having a melting point, Tm, that is from 25° C. to 30° C., or 40° C. or higher than the melting point of the polymer in the seal layer wherein the outer layer polymer is selected from resins such as AFFINITY™, LLDPE (DOWLEX™), VERSIFY™ or VISTAMAX, ELITE™, MDPE, HDPE or a propylene-based polymer such as propylene homopolymer, propylene impact copolymer or TPO.
[0038] In an embodiment, the flexible multilayer film is co-extruded.
[0039] In an embodiment, the flexible multilayer film includes a seal layer selected from LLDPE (sold under the trade name DOWLEX™ (The Dow Chemical Company)); single-site LLDPE (substantially linear, or linear, olefin polymers, for example; propylene-based plastomers or elastomers such as VERSIFY™ (The Dow Chemical Company), grafted olefin-based polymer (MAH-grafted), and blends thereof.
[0040] In an embodiment, the first flexible film and the second flexible film each is a multilayer film having three layers. Each of the layers is a blend of an LLDPE and an LDPE. Each layer includes from 60 wt %, or 70 wt % to 80 wt % of LLDPE and a reciprocal amount of LDPE, from 40 wt %, or 30 wt % to 20 wt % LDPE (based on total weight of each respective layer). In a further embodiment, each layer consists of LLDPE and LDPE in the aforementioned weight percentages.
[0041] The first flexible film and also second flexible film each consist of LLDPE and LDPE, for example. In a further embodiment, the first flexible film and the second flexible film each consists of (is composed solely of) one or more ethylene-based polymer(s). The first flexible film and the second flexible film each consists of LLDPE and LDPE, for example.
2. Inner Container
[0042] In an embodiment,
[0043] In a further embodiment, the first flexible film 12 and the second flexible film 14 each is a three layer film composed solely of ethylene-based polymer, each layer consisting of 70 wt % LLDPE and 30 wt % LDPE.
[0044] In an embodiment, the heat seal 18 is a hermetic seal.
[0045] The heat seal 18 extends along at least of portion of the common peripheral edge 16 to form a chamber 20. The chamber 20 is a sealed hermetic enclosure for holding contents as will be discussed in detail below. In an embodiment, the heat seal 18 extends along all, or substantially all, of the common peripheral edge 16, to form a closed chamber 20 as shown in
3. Surface Treated Layer
[0046] As best shown in
[0047] Polyethylene, for example, has a surface energy of about 31 mN/m in its nascent state. Each surface-treated layer 12a, 14a is composed of an ethylene-based polymer having a surface energy from 33 mN/m, or 34 mN/m to 35 mN/m, or 36 mN/m. In an embodiment, each surface-treated layer 12a, 14a has a surface energy from 34 mN/m to 35 mN/m.
4. Peel Sleeve
[0048] The present flexible container includes one or more peel sleeves. The peel sleeve(s) is/are superimposed on each respective outermost layer and along the common peripheral edge. Along with the first flexible film and the second flexible film, the peel sleeve(s) further define the common peripheral edge. The peel sleeve can be a single peel sleeve. In this embodiment, a single film serves as the peel sleeve, the single film having a fold-over bottom at the bottom portion of the flexible container.
[0049] In an embodiment, the flexible container 10 includes two peel sleeves, peel sleeve 22 and peel sleeve 24 as shown in
[0050] Each peel sleeve 22,24 is a flexible film and may be a monolayer film or a multilayer film. The material for each peel sleeve 22, 24 may be the same or different. Nonlimiting examples of suitable materials for the peel sleeves 22,24 include metal foil and polymeric material such as polyethylene terephthalate (PET), biaxially oriented polyethylene terephthalate (OPET), monoaxially oriented nylon (MON), biaxially oriented nylon (BON), and biaxially oriented polypropylene (BOPP). Other polymeric materials useful in constructing the peel sleeves are polypropylenes (such as propylene homopolymer, random propylene copolymer, propylene impact copolymer, thermoplastic polypropylene (TPO) and the like, propylene-based plastomers (e.g., VERSIFY™ or VISTAMAX™)), polyamides (such as Nylon 6, Nylon 6,6, Nylon 6,66, Nylon 6,12, Nylon 12 etc.), polyethylene norbornene, cyclic olefin copolymers, polyacrylonitrile, polyesters, copolyesters (such as PETG), cellulose esters, polyethylene and copolymers of ethylene (e.g., LLDPE based on ethylene octene copolymer such as DOWLEX™, blends thereof, and multilayer combinations thereof.
[0051] In an embodiment, peel sleeves 22,24 each is a monolayer film made of the same PET.
[0052] In an embodiment, peel sleeves 22, 24 each is a monolayer film made of the same BOPP.
5. Release Material
[0053] The present flexible container 10 includes a release material 26 as shown in
[0054] The release material 26 is a water-based adhesive composition that is generally recognized as safe (GRAS) by a regulatory body, such as the US Food and Drug Administration, for example. In an embodiment, the release material 26 is a water-based and an acrylate-based food grade adhesive that is GRAS. The present release material is a water-based composition and excludes solvent based adhesive compositions which (i) tend to generate a non-peelable bond strength, (ii) produce an odor, (iii) impart health concerns due to the presence of residual aromatics and other harmful solvent residue, and (iv) any combination of (i), (ii), and (iii). Nonlimiting examples of suitable compositions for release material 26 include acrylic water-based adhesives based on butyl acrylate.
[0055] In an embodiment, the release material is a formaldehyde-free butyl acrylate adhesive, such as Robond PS-90, available from The Dow Chemical Company.
[0056]
[0057] The release material 26 releasably attaches each peel sleeve 22, 24 to its respective surface-treated layer 12a, 14a. In an embodiment, the release material 26 adheres the peel sleeve to the its respective surface-treated layer with a bond strength from 0.00656 N/mm (17 gf/in) to 0.00386 N/mm (100 gf/in).
[0058]
[0059]
[0060] The release material 26 remains on the peel sleeves 22, 24 with no release material 26 on the surface-treated layers 12a, 14a after release. In other words, the release material 26 remains on the peel sleeves 22, 24 while being wholly absent, or substantially wholly absent, from the surface-treated layers 12a, 14a after release of the peel sleeves from the inner container.
[0061] The access member 34 is a structure that enables access to into the interior of the chamber 20. The access member extends across a bottom portion of the top heat seal 18a. In other words, actuation of the access member opens the sealed chamber 20 and enables access to the contents stored in the chamber 20. The term “actuate,” “actuated,” and like terms is the act of manipulating the access member to obtain ingress and egress to and from chamber 20. Actuation includes such nonlimiting acts as pulling, tearing, peeling, separating, folding (and any combination thereof), the access member 34 to open the chamber 20. Nonlimiting examples of suitable access members include a tear notch, a tear slit, a perforation, a line of weakness, a cut line, and combinations thereof.
[0062]
[0063] In an embodiment, the flexible container 10 includes an accessory structure located below the access member. Nonlimiting examples of suitable accessory structure include a re-seal structure such as a pressure seal, a pressure zipper, and/or a slide zipper; a microcapillary strip; and any combination thereof.
[0064] In an embodiment, the flexible container 10 includes a re-seal structure that is a slide zipper 36 as shown in
[0065] In an embodiment, the flexible container 10 includes an accessory structure that is a microcapillary strip 38, as shown in
[0066] In an embodiment, the present flexible container 10 is void of a rigid spout and/or rigid fitment.
[0067] In an embodiment, the flexible container 10 has a volume from 0.01 liters (L), or 0.05 L, or 0.1 L, or 0.25 L, or 0.5 L, or 0.75 L, or 1.0 L, or 1.5 L, or 2.5 L to 3 L, or 3.5 L, or 4.0 L, or 4.5 L, or 5.0 L.
[0068] The present flexible container is suitable for storage of flowable substances including, but not limited to, liquid comestibles and flowable solid particulate comestibles. Nonlimiting examples of suitable liquid comestibles include beverages, yogurt, condiments (ketchup, mustard, mayonnaise), butter, sauces, and baby food. Nonlimiting examples of suitable solid particulate comestibles include powders, grains, cereal, nuts, candy pieces, granular solids, animal feed, and pet food.
[0069]
[0070] Applicant discovered that (i) provision of an inner container with a surface-treated outermost layer(s) having a surface energy of 33-36 mN/m in conjunction with (ii) the release material that is a water-based acrylate work synergistically to ensure that all, or substantially all the release material 26 remains adhered to the peel sleeves 22, 24, after the peel sleeves 22, 24 are released, or otherwise separated, from the inner container 20 and as shown in
[0071] By way of example, and not limitation, examples of the present disclosure are provided.
Examples
1. Materials
[0072] Materials used in the examples and in the comparative samples are provided in Table 1 below.
TABLE-US-00001 TABLE 1 Component Description Composition and properties Source Flexible film Three layer Each layer is a blend of 70 wt The Dow (Film 1) coextruded multilayer % Dowlex ™ NG 2045NB and 30 wt Chemical film, total film % LDPE Company thickness, 60 microns Dowlex ™ NG 2045NB: density 0.920 g/cc, melt index (190° C., 2.16 kg) 1 g/10 min LDPE 132l: density 0.921 g/cc, melt index (190° C., 2.16 kg) 0.25 g/10 min Final film: density 0.9203 g/cc, melt index (190° C., 2.16 kg) 0.66 g/10 min Peel sleeve Monolayer film, total polyethylene terephthalate Terphane thickness, 17 microns Design Release Robond L90D Acrylic water-based adhesive The Dow material based on butyl acrylate. Chemical Solids 41.5%, Viscosity < 50 Company cPs, Density 1.06 kg/l Release Robond PS-90 Acrylic water-based adhesive The Dow material FDA approved for based on butyl acrylate. Chemical direct contact Solids 57%, Viscosity 200 cPs, Company with people Density 1.06 kg/l Release Adcote 548/F Polyurethane solvent-based The Dow material adhesive Chemical Solids 66%, Viscosity 4500 Company mPas, Density 1.06 g/cc Release Mor Free 152/C79 Polyurethane solvent-less The Dow material adhesive Chemical Solids 100%, Viscosity 555 Ms, Company Density 0.99 g/cc
2. Peel Sleeve Fabrication
[0073] Different samples are made using Film 1. For each sample, one layer of Film 1 is corona treated to various surface energies during extrusion. Various amounts/types of release material are spot laminated at various coating weights along the peripheral edge of Film 1. The release material is applied via rotogravure on specific areas in a way that the package has an area on the top where no release material is present. The peel sleeve is then placed on the surface treated layer of Film 1 and the release material. The area void of release material serves as a tab by which the consumer can remove the peel sleeve of the packaging. In other words, the peel sleeve includes a tab corresponding to the area where release material is omitted on Film 1.
[0074] Packaging prototypes (peel sleeve/release material/Film 1 structures) are produced and tested manually to determine peel-ability of the peel sleeve and analyzed for delamination and whether release material remains. Robond PS-90 is used in order to test a release material that is FDA approved for direct contact with consumers. The results are presented in Table 2 below.
TABLE-US-00002 TABLE 2 Film1 - to peel sleeve Laminate Film 1 bond strength Surface composition Adhesive Surface Treatment after 72 hrs after delamination Release Weight (mN/m) ASTM (gf/in) Peel analyzed by FTIR Sample material (g/m.sup.2) D2578 ASTM F904 performance Film 1 side Peel sleeve side CS1 Robond L90D 1.6 Less than 33 0 Not easy-peel Polyethylene Ethyl Acrylate (no treatment) Adhesive CS2 Robond L90D 2 Less than 33 0 Not easy-peel Polyethylene Ethyl Acrylate (no treatment) Adhesive CS3 Robond L90D 2.5 Less than 33 0 Not easy-peel Polyethylene Ethyl Acrylate (no treatment) Adhesive IE1 Robond L90D 1.6 34 17 Easy peel Polyethylene Ethyl Acrylate performance Adhesive IE2 Robond L90D 2 34 57 Easy peel Polyethylene Ethyl Acrylate performance Adhesive IE3 Robond L90D 2.5 34 61 Easy peel Polyethylene Ethyl Acrylate performance Adhesive IE4 Robond PS-90 2 34 100 Easy peel Polyethylene Ethyl Acrylate performance Adhesive CS4 Robond PS-90 2 38 800 Not easy-peel Polyethylene Ethyl Acrylate Adhesive CS5 Robond L90D 1.6 36 114 Not easy-peel Ethyl Acrylate PET Adhesive CS6 Robond L90D 2 36 123 Not easy-peel Polyethylene Ethyl Acrylate Adhesive CS7 Robond L90D 2.5 36 165 Not easy-peel Ethyl Acrylate PET Adhesive CS8 Robond L90D 1.6 38 158 Not easy-peel Polyethylene Ethyl Acrylate Adhesive CS9 Robond L90D 2 38 153 Not easy-peel Polyethylene Ethyl Acrylate Adhesive CS10 Robond L90D 2.5 38 164 Not easy-peel Polyethylene Ethyl Acrylate Adhesive CS11 Adcote 548/F 1.8 34 Film Not easy-peel destruction CS12 Mor free 1.8 34 Packaging — — — 152/C79 failure CS = Comparative Sample IE—Inventive Example
[0075] Applicant discovered that Film 1 surface-treated to 34-35 mN/m delivers a low bond strength between the Film 1-release material interface and achieves easy peel performance. When release occurs, release material remains on the PET side due to its higher polarity (PET has higher surface energy) leaving the Film 1 clean for direct mouth contact by a consumer.
[0076] Comparative sample 11 (CS11) demonstrates that solvent-based adhesive (e.g., Adcote 548/E) generates high bond strength which makes the packaging lose its peelable property inhibiting the consumer of opening it manually.
[0077] Inventive examples 1, 2, 3, 4 show that prototypes are easy-peel when the first and second flexible films are surface-treated to 34 mN/m, and release material is applied at adhesive weight between 1.6-2.5 g/m.sup.2, reporting a lamination bond strength between 0.00656 N/mm-0.02353 N/mm (17-61 gf/in) and no contamination of release material on Film 1 surface when the peel sleeve is pulled away.
[0078] Comparative sample 11 (CS11) manufactured using Adcote 548/F (solvent-based adhesive) had bond strength high enough to destroy the films when the delamination test was performed.
[0079] Comparative sample 12 (CS12) manufactured with MorFree 152/C79 (solvent-less adhesive) failed during the manufacturing of the package. The one spot lamination was not able to be achieved due to the low viscosity of the adhesive.
[0080] It is specifically intended that the present disclosure not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.