Patent US5322726A successfully refreshed from Google Patents.
US5322726A
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US
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Coextruded film having high oxygen transmission rate
Assignee: Printpack Illinois Inc
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Filing: 1993-03-19
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Granted: 1994-06-21
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Expires: 2013-03-19
Abstract
Abstract A coextruded film having an oxygen transmission rate between about 160 and 375, making it especially suitable for packaging fresh produce, comprises a skin layer of polypropylene, a core layer of ethylene-vinyl acetate copolymer, and a heat seal layer of ultra linear low density polyethylene.
Inventors
- 👤 Jimmy S. Dew
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:42
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/30; B32B27/306; B32B27/32; B32B2307/00; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/7244; B32B2323/00; B32B2323/04; B32B2323/046; B32B2323/10; B32B2331/00; B32B2331/04; B32B2439/00; B32B2439/70; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
69 words
A coextruded film having an oxygen transmission rate between about 160 and 375 cc/100 square inches/24 hours, said film having a temperature-resistant skin layer comprising polypropylene having from zero to six percent ethylene copolymerized therewith, a core layer comprising a copolymer of ethylene and vinyl acetate, and a heat sealable skin layer comprising ultra linear low density polyethylene, wherein the film has a thickness between about 1.25 and 2.75.
Claim 2
Dependent Claim
69 words
A coextruded film having an oxygen transmission rate between about 160 and 375 cc/100 square inches/24 hours, said film having a temperature-resistant skin layer comprising polypropylene having from zero to six percent ethylene copolymerized therewith, a core layer comprising a copolymer of ethylene and vinyl acetate, and a heat sealable skin layer comprising ultra linear low density polyethylene, wherein the film has a thickness between about 1.25 and 2.75.
Claim 3
Dependent Claim
35 words
The film of claim 1 wherein each skin layer comprises from about 15 to 40 percent of the thickness of the film and the core layer comprises from 40 to 60 percent of the thickness.
Claim 4
Dependent Claim
22 words
The film of claim 2 wherein the vinyl acetate content of the ethylene-vinyl acetate copolymer is between about 9 and 15 percent.
Claim 5
Dependent Claim
22 words
The film of claim 3 wherein the heat seal layer has a heat seal activation temperature between about 170° and 190° F.
Claim 6
Dependent Claim
21 words
The film of claim 4 having a haze of less than 15 percent and a gloss of more than 35 percent.
Claim 7
Dependent Claim
32 words
The film of claim 5 wherein the film is made by the blown film process and the copolymer of ethylene and vinyl acetate has a melt index between about 0.2 and 0.4.
Claim 8
Dependent Claim
17 words
The film of claim 6 wherein the polypropylene has from three to six percent ethylene copolymerized therewith.
References Cited (Backward Citations)
US4657610A
Cited
US4935271A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-20 | 1997-12-20 | 1998-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-20 | 2001-12-20 | 2002-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-20 | 2005-12-20 | 2006-06-21 | $7700.00 | Window Closed / Lapsed |