Patent US4421823A successfully refreshed from Google Patents.
US4421823A
Expired / Lapsed
US
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Flexible wrapping material and method of manufacture
Assignee: Curwood Inc
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Filing: 1982-06-01
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Granted: 1983-12-20
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Expires: 2002-06-01
Abstract
Abstract A flexible wrapping material comprising a film laminate is provided for packaging of food products which is resistant to flex-cracking and pinhole development, is impervious to liquids and gasses, and exhibits the property of grease-resistance without the use of adhesives to promote bonds between the layers. The film laminate consists of an outer layer of heat-set, biaxially oriented polymeric material followed by a layer of polymeric material, a layer of oxygen barrier polymer, a layer of biaxially oriented polypropylene, a special grease-resistant polymer, and an inner layer of heat-sealable polymeric material. The film laminate is made by bonding the outer surface layer of heat-set, biaxially oriented polymer to a substrate in which an oxygen barrier material is carried on a biaxially oriented polypropylene/special grease-resistant polymer by means of an intermediate layer of polymeric material. A layer of heat-sealable polymeric material is then extrusion-coated on the special polymer surface to form the inner layer of the laminate.
Inventors
- 👤 Henry J. Theisen
- 👤 Willard H. Gehrke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:07
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B2323/00; B32B2323/04; B32B2323/10; B32B2367/00; Y; Y10; Y10T; Y10T428/00; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31786; Y10T428/31797; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928; Y10T428/31935
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
177 words
A film laminate of flexible, heat-sealable wrapping material, particularly suitable for use in the packaging of products which are to be maintained in hermetically sealed relationship to the atmosphere, comprising a first outer layer of heat-set, biaxially oriented polymeric material bonded on its inner side to a layer of polymeric material which is sandwiched between said outer layer and a layer of oxygen barrier polymer, adapted to provide a barrier against the migration of oxygen through the laminate, a layer of biaxially oriented polypropylene disposed between said layer of oxygen barrier polymer and a layer of special grease-resistant polymer bonding, without the use of a solvent, said layer of biaxially oriented polypropylene to an inner layer of heat-sealable polymeric material having a lower melting point than said outer layer whereby said layer of special grease-resistant polymer is resistant to food oils and greases and is selected from the group consisting of polyethylene, copolymers of vinyl acetate having a vinyl acetate content of approximately 12 percent or less, copolymers of ethylene acrylic acid, ethylene-vinyl acetate terpolymers, and ionomers.
Claim 2
Dependent Claim
177 words
A film laminate of flexible, heat-sealable wrapping material, particularly suitable for use in the packaging of products which are to be maintained in hermetically sealed relationship to the atmosphere, comprising a first outer layer of heat-set, biaxially oriented polymeric material bonded on its inner side to a layer of polymeric material which is sandwiched between said outer layer and a layer of oxygen barrier polymer, adapted to provide a barrier against the migration of oxygen through the laminate, a layer of biaxially oriented polypropylene disposed between said layer of oxygen barrier polymer and a layer of special grease-resistant polymer bonding, without the use of a solvent, said layer of biaxially oriented polypropylene to an inner layer of heat-sealable polymeric material having a lower melting point than said outer layer whereby said layer of special grease-resistant polymer is resistant to food oils and greases and is selected from the group consisting of polyethylene, copolymers of vinyl acetate having a vinyl acetate content of approximately 12 percent or less, copolymers of ethylene acrylic acid, ethylene-vinyl acetate terpolymers, and ionomers.
Claim 3
Dependent Claim
17 words
A film laminate in accordance with claim 1 wherein said outer layer is heat-set, biaxially oriented polypropylene.
Claim 4
Dependent Claim
17 words
A film laminate in accordance with claim 1 wherein said outer layer is heat-set, biaxially oriented polyester.
Claim 5
Dependent Claim
26 words
A film laminate in accordance with claim 1 wherein said layer of polymeric material sandwiches between said outer layer and said oxygen barrier layer is polyethylene.
Claim 6
Dependent Claim
16 words
A flim laminate in accordance with claim 1 wherein said oxygen barrier layer is polyvinylidene chloride.
Claim 7
Dependent Claim
16 words
A film laminate in accordance with claim 1 wherein said oxygen barrier layer is ethylene-vinyl alcohol.
Claim 8
Dependent Claim
17 words
A film laminate in accordance with claim 1 wherein said layer of special grease-resistant polymer is polyethylene.
Claim 9
Dependent Claim
32 words
A film laminate in accordance with claim 1 wherein said layer of special grease-resistant polymer is a copolymer of vinyl acetate having a vinyl acetate content of approximately 12 percent or less.
Claim 10
Dependent Claim
22 words
A film laminate in accordance with claim 1 wherein said layer of special grease-resistant polymer is a copolymer of ethylene acrylic acid.
Claim 11
Dependent Claim
20 words
A film laminate in accordance with claim 1 wherein said layer of special grease-resistant polymer is an ethylene-vinyl acetate terpolymer.
Claim 12
Dependent Claim
18 words
A film laminate in accordance with claim 1 wherein said layer of special grease-resistant polymer is an ionomer.
Claim 13
Independent Claim
117 words
A method of making a film laminate of flexible, heat-sealable wrapping material, suitable for use in the packaging of products which are to be maintained in hermetically sealed relationship to the atmosphere, the steps of the method comprising forming a substrate of oxygen barrier material/biaxially oriented polypropylene/special grease-resistant polymer by emulsion-coating of the oxygen barrier material onto a coextrusion of biaxially oriented polypropylene and special grease-resistant polymer, extrusion laminating an outer layer of heat-set, biaxially oriented polymeric material onto said oxygen barrier surface of said substrate with a layer of polymeric material in its molten state and extrusion coating, as an inner layer, a heat-sealable polymeric material onto said special grease resistant polymeric surface of said substrate.
Claim 14
Independent Claim
117 words
A method of making a film laminate of flexible, heat-sealable wrapping material, suitable for use in the packaging of products which are to be maintained in hermetically sealed relationship to the atmosphere, the steps of the method comprising forming a substrate of oxygen barrier material/biaxially oriented polypropylene/special grease-resistant polymer by emulsion-coating of the oxygen barrier material onto a coextrusion of biaxially oriented polypropylene and special grease-resistant polymer, extrusion laminating an outer layer of heat-set, biaxially oriented polymeric material onto said oxygen barrier surface of said substrate with a layer of polymeric material in its molten state and extrusion coating, as an inner layer, a heat-sealable polymeric material onto said special grease resistant polymeric surface of said substrate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |