# US 2013/0153577 A1 · Peelable closure for container > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153577 A1 - Document ID: US20130153577A1 - Status: Published application - Kind: A1 - Application number: 13/327,211 - Filed: 2011-12-15 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: Berry Plastics Corporation - Inventors: Jau-Ming Su; Charisa Sofian; Paul Wolak - Web page: https://patentgrep.com/patent/US20130153577A1 ## CPC - B32B 27/08: of synthetic resin - B32B 7/12: using interposed adhesives or interposed materials with bonding properties - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - B32B 27/36: comprising polyesters - B65D 1/34: Trays or like shallow containers {(B65D81/3813 takes precedence)} - B65D 7/045: {Casks, barrels, or drums in their entirety, e.g. beer barrels, i.e. presenting most of the following features like rolling beads, double walls, reinforcing and supporting beads for end walls (thermally insulated barrels, B65D81/3802)} - B65D 81/3453: {Rigid containers, e.g. trays, bottles, boxes, cups} - B32B 2250/02: 2 layers - B32B 2250/04: 4 layers - B32B 2250/24: All layers being polymeric - B32B 2307/306: Resistant to heat - B32B 2307/31: Heat sealable - B32B 2439/00: Containers; Receptacles - B32B 2439/70: Food packaging - B65D 2581/3445: Microwave reactive adhesives, e.g. also used in valves or lids - Y10T 428/2817: Heat sealable - Y10T 428/2848: Three or more layers - Y10T 428/2878: including addition polymer from unsaturated monomer - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A steam-ventable package includes a container formed to include an interior region and a mouth opening into the interior region and a closure coupled to the container to close the mouth. The closure is made from a peelable film coupled to a brim included in the container and configured to be removed from the brim in response to application of shear force applied to the peelable film. ## Claims ### Claim 1 A cold-durable, heat-resistant, peelable film for packaging a food product, comprising (a) a sealant layer and (b) a protective layer, wherein i) the sealant layer is a polypropylene-based monolayer polyolefin layer comprising at least one polyethylene polymer resin or a polypropylene-based multilayer polyolefin film comprising at least two different polyethylene polymer resins, ii) the sealant layer does not fracture when exposed to a temperature in a range of about −20° C. to about 0° C., iii) the sealant layer does not melt or burst when exposed to a temperature of up to about 105° C. without melting, iv) the sealant layer may be peeled either before or after heating with a peel force in a range of about 1 lbf/in to about 5 lbf/in, and v) the protective layer may be included as part of the sealant layer. ### Claim 2 (depends on 1) The cold-durable, heat-resistant, peelable film of claim 1, wherein the sealant layer is a polypropylene-based multilayer polyolefin layer comprising (a) an inner heat sealable sub-layer formed from at least one polypropylene/alpha-olefin copolymer, the polypropylene/alpha-olefin copolymer having a melt flow rate in a range of about 0.5 g/10 min. to about 45 g/10 min, and at least two different polyethylene polymer resins one of which has a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min., (b) a core sub-layer adjacent to the inner heat sealable sub-layer, the core sub-layer being formed from a polymeric material having a melting point of at least 71° C., and (c) an outer skin sub-layer formed from at least one polyethylene polymer resin, the at least one polyethylene polymer resin having a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min, wherein the protective layer is laminated to the outer skin sub-layer, the protective layer being formed from a polymer material that is temperature resistant at a temperature of up to about 105° C. and wherein the cold-durable, heat-resistant, peelable film can be used to establish a closure that is coupled to a container included in a package that permits a food product to be heated. ### Claim 3 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein the polypropylene/alpha-olefin copolymer comprises a propylene/ethylene copolymer containing ethylene comonomer in an amount in a range of about 1% to about 8% by weight of the copolymer. ### Claim 4 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein the heat sealable sub-layer comprises a blend of polypropylene/alpha-olefin copolymers. ### Claim 5 (depends on 4) The cold-durable, heat-resistant, peelable film of claim 4, wherein the blend of polypropylene/alpha-olefin copolymers comprises a propylene/ethylene copolymer containing ethylene comonomer in an amount in a range of about 1% to about 8% by weight. ### Claim 6 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein the polypropylene/alpha-olefin copolymer has a melting temperature greater than 71° C. ### Claim 7 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein the core sub-layer comprises a homopolymer polypropylene and a polyethylene polymer resin. ### Claim 8 (depends on 7) The cold-durable, heat-resistant, peelable film of claim 7, wherein the homopolymer polypropylene has a melt flow rate in a range of about 0.5 g/10 min. to about 25 g/10 min. ### Claim 9 (depends on 7) The cold-durable, heat-resistant, peelable film of claim 7, wherein the polyethylene polymer resin has a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min. ### Claim 10 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein the outer skin sub-layer includes a homopolymer polypropylene having a melt flow rate in a range of about 0.5 g/10 min. to about 25 g/10 min. ### Claim 11 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein the protective layer is formed from a material selected from the group consisting of a polyethylene terephthalate film, a nylon film, a biaxially oriented polypropylene film, and a biaxially oriented propylene/ethylene copolymer film. ### Claim 12 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein an adhesive layer is used to laminate the protective layer to the outer skin sub-layer. ### Claim 13 (depends on 12) The cold-durable, heat-resistant, peelable film of claim 12, wherein the adhesive layer comprises a polyurethane adhesive. ### Claim 14 (depends on 12) The cold-durable, heat-resistant, peelable film of claim 12, wherein the adhesive layer is formed from a material selected from the group consisting of a polyurethane adhesive, polyester-polyurethane adhesive, a hot-melt of ethylene vinyl acetate, a hot-melt of polyamide, and a hot-melt of polyester. ### Claim 15 (depends on 2) The cold-durable, heat-resistant, peelable film of claim 2, wherein the multilayer polyolefin layer is either a coextruded blown film, a coextruded cast film, or a laminated film. ### Claim 16 (depends on 1) The cold-durable, heat-resistant, peelable film of claim 1, wherein the sealant layer is a polypropylene-based multilayer polyolefin layer comprising (a) an inner heat sealable sub-layer formed from at least one polypropylene/alpha-olefin copolymer, the polypropylene/alpha-olefin copolymer having a melt flow rate in a range of about 0.5 g/10 min. to about 45 g/10 min, and at least two different polyethylene polymer resins one of which has a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min., (b) a core sub-layer adjacent to the heat sealable sub-layer, the core sub-layer being formed from a polymeric material having a melting point of at least 71° C., and (c) an outer skin sub-layer formed from a homopolymer polypropylene resin, the homopolymer polypropylene resin having a melt flow rate in a range of about 0.50 g/10 min. to about 25 g/10 min, wherein the protective layer is the outer skin sub-layer and wherein the cold-durable, heat-resistant, peelable film can be used to establish a closure that is coupled to a container included in a package that permits the food product to be heated in a microwave oven or other source of heating energy. ### Claim 17 (depends on 16) The cold-durable, heat-resistant, peelable film of claim 16, wherein the heat sealable sub-layer comprises a blend of polypropylene/alpha-olefin copolymers. ### Claim 18 (depends on 17) The cold-durable, heat-resistant, peelable film of claim 17, wherein the blend of polypropylene/alpha-olefin copolymers comprises a propylene/ethylene copolymer containing ethylene comonomer in an amount in a range of about 1% to about 8% by weight. ### Claim 19 (depends on 16) The cold-durable, heat-resistant, peelable film of claim 16, wherein the polypropylene/alpha-olefin copolymer has a melting temperature greater than 71° C. ### Claim 20 (depends on 16) The cold-durable, heat-resistant, peelable film of claim 16, wherein the core sub-layer comprises at least one homopolymer polypropylene and at least one polyethylene polymer resin. ### Claim 21 (depends on 16) The cold-durable, heat-resistant, peelable film of claim 16, wherein the multilayer polyolefin layer is either a coextruded blown film, a coextruded cast film, or a laminated film. ### Claim 22 (depends on 1) The cold-durable, heat-resistant, peelable film of claim 1, wherein the sealant layer is a polypropylene-based monolayer polyolefin film comprising at least one polypropylene/alpha-olefin copolymer, the polypropylene/alpha-olefin copolymer having a melt flow rate in a range of about 0.5 g/10 min. to about 45 g/10 min, and low density polyethylene resin, the protective layer is laminated to the monolayer polyolefin film, the protective layer being formed from a polymer material that is temperature resistant at a microwave or other oven temperature of about 105° C., and the cold-durable, heat-resistant, peelable film is adapted to establish a closure that is coupled to a container included in a package that permits the frozen food product to be heated in a microwave oven or other source of heat energy. ### Claim 23 (depends on 22) The cold-durable, heat-resistant, peelable film of claim 22, wherein the monolayer polyolefin film comprises a blend of at least two polypropylene/alpha-olefin copolymers. ### Claim 24 (depends on 23) The cold-durable, heat-resistant, peelable film of claim 23, wherein the blend of polypropylene/alpha-olefin copolymers comprises a propylene/ethylene copolymer containing ethylene comonomer in an amount in a range of about 1% to about 8% by weight. ### Claim 25 (depends on 22) The cold-durable, heat-resistant, peelable film of claim 22, wherein the polypropylene/alpha-olefin copolymer has a melting temperature greater than 71° C. ### Claim 26 (depends on 22) The cold-durable, heat-resistant, peelable film of claim 22, wherein the protective layer is formed from a material selected from the group consisting of a polyethylene terephthalate film, a nylon film, a biaxially oriented polypropylene film, and a biaxially oriented propylene/ethylene copolymer film. ### Claim 27 (depends on 22) The cold-durable, heat-resistant, peelable film of claim 22, wherein an adhesive layer is adapted to laminate the protective layer to the monolayer polyolefin layer. ### Claim 28 (depends on 27) The cold-durable, heat-resistant, peelable film of claim 27, wherein the adhesive layer comprises a polyurethane adhesive. ### Claim 29 (depends on 27) The cold-durable, heat-resistant, peelable film of claim 27, wherein the adhesive layer is formed from a material selected from the group consisting of a polyurethane adhesive, polyester-polyurethane adhesive, a hot-melt of ethylene vinyl acetate, a hot-melt of polyamide, and a hot-melt of polyester. ### Claim 30 (depends on 1) The cold-durable, heat-resistant, peelable film of claim 1, further comprising a venting system. ### Claim 31 (depends on 1) The cold-durable, heat-resistant, peelable film of claim 1, wherein the sealant layer may be peeled either before or after heating with a peel force in a range of about 1 lbf/in to about 3 lbf/in. ### Claim 32 A product, comprising (a) a food product and (b) a package containing the food product, the package comprising a container and a cold-durable, heat-resistant, peelable film, wherein the cold-durable, heat-resistant, peelable film comprises a sealant layer comprising (i) an inner heat sealable sub-layer formed from at least one polypropylene/alpha-olefin copolymer, the polypropylene/alpha-olefin copolymer having a melt flow rate in a range of about 0.5 g/10 min. to about 45 g/10 min, and at least two different polyethylene polymer resins one of which has a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min, (ii) a core sub-layer adjacent to the heat sealable sub-layer, the core sub-layer being formed from a polymeric material having a melting point of at least 71° C., and (iii) an outer skin sub-layer formed from at least one polyethylene polymer resin, the at least one polyethylene polymer resin having a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min, and a protective layer laminated to the outer skin sub-layer, the protective layer being formed from a polymer material that is temperature resistant at a temperature of about 105° C., wherein the sealant layer does not fracture when exposed to a temperature in a range of about −20° C. to about 0° C., wherein the sealant layer may be peeled either before or after heating with a peel force in a range of about 1 lbf/in to about 5 lbf/in, and wherein the package permits the frozen food to be heated directly in a microwave or other oven at a temperature of up to about 105° C. without melting or bursting the container. ### Claim 33 (depends on 32) The product of claim 32, wherein the sealant layer of the cold-durable, heat-resistant, peelable film may be peeled either before or after heating with a peel force in a range of about 1 lbf/in to about 3 lbf/in. ### Claim 34 A lid for a container, the lid comprising (a) a brim adapted to be fittable on or around a rim of the container, (b) a cold-durable, heat-resistant, peelable film associated with the brim and comprising (i) a sealant layer comprising: (A) an inner heat sealable sub-layer formed from at least one polypropylene/alpha-olefin copolymer, the polypropylene/alpha-olefin copolymer having a melt flow rate in a range of about 0.5 g/10 min. to about 45 g/10 min, and at least two different polyethylene polymer resins one of which has a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min, (B) a core sub-layer adjacent to the heat sealable sub-layer, the core sub-layer being formed from a polymeric material having a melting point of at least 71° C., and (C) an outer skin sub-layer formed from at least one polyethylene polymer resin, the at least one polyethylene polymer resin having a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min, and (ii) a protective layer laminated to the outer skin sub-layer, the protective layer being formed from a polymer material that is temperature resistant at a temperature of about 105° C., and (c) an adhesive associated with the rim to facilitate attachment of the lid to a container, wherein the sealant layer does not fracture when exposed to a temperature in a range of about −20° C. to about 0° C., wherein the sealant layer may be peeled either before or after heating with a peel force in a range of about 1 lbf/in to about 5 lbf/in, and wherein the container permits the frozen food to be heated directly in a microwave oven or other source of heating energy at a temperature of up to about 105° C. without melting or bursting the container. ### Claim 35 A steam venting system, comprising (a) a container and (b) a cold-durable, heat-resistant, peelable film associated with the container and comprising (i) a sealant layer comprising (A) an inner heat sealable sub-layer formed from at least one polypropylene/alpha-olefin copolymer, the polypropylene/alpha-olefin copolymer having a melt flow rate in a range of about 0.5 g/10 min. to about 45 g/10 min, and at least two different polyethylene polymer resins one of which has a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min, (B) a core sub-layer adjacent to the heat sealable sub-layer, the core sub-layer being formed from a polymeric material having a melting point of at least 71° C., and (C) an outer skin sub-layer formed from at least one polyethylene polymer resin, the at least one polyethylene polymer resin having a melt index in a range of about 0.50 g/10 min. to about 20 g/10 min, and (ii) a protective layer laminated to the outer skin sub-layer, the protective layer being formed from a polymer material that is temperature resistant at a temperature of about 105° C., wherein the sealant layer does not fracture when exposed to a temperature in a range of about −20° C. to about 0° C., wherein the sealant layer may be peeled either before or after heating with a peel force in a range of about 1 lbf/in to about 5 lbf/in, and wherein the container permits the frozen food to be heated directly in a microwave or other oven at a temperature of up to about 105° C. without melting or bursting the container, and (c) a plurality of venting apertures extending through the peelable film so as to create a plurality of open passageways through which steam can pass from within the container to the outside. ### Claim 36 (depends on 35) The steam venting system of claim 35, wherein the plurality of venting apertures comprises a first set of slits extending and spaced across a portion of and proximate to a first edge of the peelable film and a second set of slits extending and spaced across a portion of and proximate to a second edge of the peelable film and generally parallel to the first set of slits, the second edge of the peelable being opposite the first edge. ### Claim 37 (depends on 36) The steam venting system of claim 36, wherein each slit comprises a slit passageway in each layer and sub-layer whereby the slit passageways are aligned to provide an open passageway through the peelable film such that steam generated when the container is subjected to heating energy is able to escape through at least a portion of the plurality of slits. ### Claim 38 A method of heating an article in a container and venting steam created therefrom, comprising a) providing an article to be heated; b) providing a receptacle for holding the article, the receptacle comprising a container and cold-durable, heat-resistant, peelable film, comprising (i) a sealant layer, (ii) a protective layer, wherein A) the sealant layer is a polypropylene-based monolayer polyolefin layer comprising at least one polyethylene polymer resin or a polypropylene-based multilayer polyolefin film comprising at least two different polyethylene polymer resins, B) the sealant layer does not fracture when exposed to a temperature in the a range of about −20° C. to about 0° C., C) the sealant layer does not melt or burst when exposed to a temperature of up to about 105° C. without melting, D) the sealant layer may be peeled either before or after heating with a peel force in a range of about 1 lbf/in to about 3 5 lbf/in, and E) the protective layer may be included as part of the sealant layer, and (iii) a plurality of venting apertures extending through the peelable film so as to create a plurality of open passageways through which steam can pass from within the container to the outside, c) applying the peelable film to the container containing the article so as to form a seal, and d) heating the article by applying energy to the article in the form of either heat or microwave energy such that seam created during heating is vented outside the container via the plurality of venting apertures. ### Claim 39 (depends on 38) The method of claim 38, further comprising e) peeling the peelable film at least partially from the container so as to provide access to the article contained therein.