Patent US4927708A successfully refreshed from Google Patents.
US4927708A
Expired / Lapsed
US
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Flexible stretch/shrink film
Assignee: Cryovac LLC
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Filing: 1988-07-26
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Granted: 1990-05-22
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Expires: 2008-07-26
Abstract
Abstract A multi-layered thermoplastic polyolefin film having an improved combination of physical characteristics is disclosed. In particular, the multi-layered film evidences an improved combination of abuse resistance, elongation, and flexibility. Preferred five layer embodiments of the film comprise (1) a core layer of very low density polyethylene; (2) two adjacent intermediate layers of a linear low density polyethylene and (3) two outer layers of an ethylene vinyl acetate copolymer or very low density polyethylene.
Inventors
- 👤 Vincent W. Herran
- 👤 George D. Wofford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:14
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B2250/00; B32B2250/05; B32B2323/00; B32B2323/04; B32B2323/046; B32B2553/00; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/26; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
87 words
In a multilayer thermoplastic packaging film having at least five layers, including a layer of linear low density polyethylene, the improvement wherein: (a) a core layer comprises a very low density polyethylene; (b) intermediate layers adjacent each side of the core layer comprise a linear low density polyethylene; and (c) two outer layers each bonded to a respective intermediate layer comprise a very low density polyethylene; wherein the film has a modulus at 73° F. of less than about 17,000 p.s.i. in the longitudinal and transverse directions.
Claim 2
Dependent Claim
87 words
In a multilayer thermoplastic packaging film having at least five layers, including a layer of linear low density polyethylene, the improvement wherein: (a) a core layer comprises a very low density polyethylene; (b) intermediate layers adjacent each side of the core layer comprise a linear low density polyethylene; and (c) two outer layers each bonded to a respective intermediate layer comprise a very low density polyethylene; wherein the film has a modulus at 73° F. of less than about 17,000 p.s.i. in the longitudinal and transverse directions.
Claim 3
Dependent Claim
10 words
The film of claim 1 wherein each layer is cross-linked.
Claim 4
Dependent Claim
28 words
The film of claim 1 having a modulus of less than about 17,000 p.s.i. in the longitudinal direction and less than about 13,000 p.s.i. in the transverse direction.
Claim 5
Dependent Claim
30 words
The film of claim 1 having an elongation, at break at 73 ° F. of at least about 220% in the longitudinal direction and about 250% in the transverse direction.
References Cited (Backward Citations)
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Cited
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |