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US4448792A
Expired / Lapsed
US
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Pasteurizable and cook-in shrink bag constructed of a multilayer film
Assignee: Cryovac LLC
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Filing: 1982-07-26
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Granted: 1984-05-15
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Expires: 2002-07-26
Abstract
Abstract A pasteurizable, cook-in shrink bag is provided that comprises a first or sealing and food contact layer composed of propylene homopolymer or copolymer; a second or heat shrinkable layer composed of a blend of propylene homopolymer or copolymer and butylene homopolymer or copolymer; a third or adhesive layer composed of ethylene methacrylate copolymer; a fourth or barrier layer composed of vinylidene chloride copolymer; a fifth or adhesive layer as in said third layer; and a sixth or optical clarity layer as in said first layer; further provided that the foregoing bag structure is oriented and irradiated to a dose of about 4-12 megarads after orienting or alternatively, though less preferred, to about 6-12 megarads before orienting. Associated method for making said bag is also provided.
Inventors
- 👤 Henry G. Schirmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:54
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B1/00; B32B1/08; B32B27/30; B32B27/304; B32B27/32; B32B7/00; B32B7/04; B32B7/12; B65; B65D; B65D81/00; B65D81/34; B65D81/3415; B65D81/3423; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/70; B32B2307/718; B32B2307/724; B32B2307/7242; B32B2307/732; B32B2307/734; B32B2307/736; B32B2309/00; B32B2309/08; B32B2309/10; B32B2309/105; B32B2439/00; B32B2439/70; B32B2597/00; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10S428/913; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1334; Y10T428/1341; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
A pasteurizable, cook-in shrink bag constructed of a multilayer film comprising: (a) a first or sealing and food contact layer comprising propylene homopolymer or copolymer; (b) a second or heat shrinkable layer comprising a blend of said propylene polymer with about 30-70% by weight of butylene homopolymer or compolymer; (c) a third or adhesive layer being irradiatively crosslinkable and comprising a copolymer of ethylene; (d) a fourth or barrier layer comprising vinylidene chloride copolymer; (e) a fifth or adhesive layer as in said third layer; and (f) a sixth or optical clarity layer as in said first layer; (g) further provided that said film is oriented and irradiated to at least a dosage sufficient to render said film delamination resistant during pasteurizing or cooking of a food product contained in said bag.
Claim 2
Dependent Claim
132 words
A pasteurizable, cook-in shrink bag constructed of a multilayer film comprising: (a) a first or sealing and food contact layer comprising propylene homopolymer or copolymer; (b) a second or heat shrinkable layer comprising a blend of said propylene polymer with about 30-70% by weight of butylene homopolymer or compolymer; (c) a third or adhesive layer being irradiatively crosslinkable and comprising a copolymer of ethylene; (d) a fourth or barrier layer comprising vinylidene chloride copolymer; (e) a fifth or adhesive layer as in said third layer; and (f) a sixth or optical clarity layer as in said first layer; (g) further provided that said film is oriented and irradiated to at least a dosage sufficient to render said film delamination resistant during pasteurizing or cooking of a food product contained in said bag.
Claim 3
Dependent Claim
16 words
The bag of claim 1 further provided that said bag is post-irradiated to crosslink said adhesive.
Claim 4
Dependent Claim
15 words
The bag of claim 1 further provided that said third layer comprises ethylene methacrylate copolymer.
Claim 5
Dependent Claim
19 words
The bag of claim 3 further provided that said bag is post-irradiated to a dose of about 4-12 megarads.
Claim 6
Dependent Claim
12 words
The bag of claim 4 wherein said dose is about 4-6 megarads.
Claim 7
Dependent Claim
19 words
The bag of claim 3 further provided that said bag is pre-irradiated to a dose of about 6-12 megarads.
Claim 8
Dependent Claim
28 words
The bag of claim 1 further provided that the blend ratio of said second layer corresponds to substantially maximum shrink properties of said bag in near boiling water.
Claim 9
Dependent Claim
19 words
The bag of claim 7 wherein said blend ratio is about 60% by weight and said butylene is butene-1.
Claim 10
Dependent Claim
26 words
The bag of claim 1 further provided that said propylene and butylene are each copolymers having a minor amount of ethylene or butylene to promote orientability.
Claim 11
Dependent Claim
78 words
The bag of claim 1 wherein said first layer has a thickness of about 0.36 mils, said second layer has a thickness of about 0.89 mils, said third layer has a thickness of about 0.12 mils, said fourth layer has a thickness of about 0.20 mils, said fifth layer has a thickness of about 0.25 mils, and said sixth layer has a thickness of about 0.18 mils, and said bag has an overall thickness of about 2 mils.
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) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |