US4935271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lettuce packaging film
Assignee: Cryovac LLC
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Filing: 1988-09-06
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Granted: 1990-06-19
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Expires: 2008-09-06
Abstract
Abstract A multilayer laminate comprises a first perforated film of propylene homopolymer or copolymer, and a second film bonded to the first film and including a bonding layer of ethylene vinyl acetate copolymer and an outer heat sealable layer.
Inventors
- 👤 Henry G. Schirmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:26
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/18; B32B27/30; B32B27/306; B32B27/32; B32B3/00; B32B3/26; B32B3/266; B32B37/00; B32B37/14; B32B37/15; B32B37/153; B32B38/00; B32B38/0008; B32B7/00; B32B7/04; B32B7/12; B32B2305/00; B32B2305/02; B32B2305/026; B32B2307/00; B32B2307/30; B32B2307/31; B32B2310/00; B32B2310/14; B32B2323/00; B32B2323/04; B32B2323/046; B32B2323/10; B32B2331/00; B32B2331/04; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1334; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/2848; Y10T428/2852; Y10T428/2878; Y10T428/31; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
61 words
A multilayer laminate comprising: (a) a first perforated film comprising propylene homopolymer or copolymer; and (b) a second film, bonded to the first film, including a bonding layer of ethylene vinyl acetate copolymer, and an outer heat sealable layer, wherein the bonding layer of ethylene vinyl acetate copolymer is located between the first perforated film and the outer heat sealable layer.
Claim 2
Dependent Claim
61 words
A multilayer laminate comprising: (a) a first perforated film comprising propylene homopolymer or copolymer; and (b) a second film, bonded to the first film, including a bonding layer of ethylene vinyl acetate copolymer, and an outer heat sealable layer, wherein the bonding layer of ethylene vinyl acetate copolymer is located between the first perforated film and the outer heat sealable layer.
Claim 3
Dependent Claim
16 words
A multilayer laminate according to claim 1 wherein the first perforated film comprises a propylene homopolymer.
Claim 4
Dependent Claim
27 words
A multilayer laminate according to claim 1 wherein the bonding layer of the second film comprises a high vinyl acetate, low melting point ethylene vinyl acetate copolymer.
Claim 5
Dependent Claim
29 words
A multilayer laminate according to claim 3 wherein the ethylene vinyl acetate copolymer has a vinyl acetate content, by weight of the resin, of between about 4.5% and 28%.
Claim 6
Dependent Claim
23 words
A multilayer laminate according to claim 1 wherein the outer heat sealable layer of the second film is an ethylene vinyl acetate copolymer.
Claim 7
Dependent Claim
27 words
A multilayer laminate according to claim 5 wherein the outer heat sealable layer of the second film is the same material as that of the bonding layer.
Claim 8
Dependent Claim
28 words
A multilayer laminate according to claim 5 further comprising a core layer of linear low density polyethylene disposed between the bonding layer and the outer heat sealable layer.
Claim 9
Dependent Claim
34 words
A multilayer laminate according to claim 7 wherein an intermediate layer of ethylene vinyl acetate copolymer is disposed between and bonds the core layer to each of the bonding and heat sealable layers respectively.
Claim 10
Dependent Claim
23 words
A multilayer laminate according to claim 1 wherein the outer heat sealable layer of the second film is a very low density polyethylene.
Claim 11
Dependent Claim
31 words
A multilayer laminate according to claim 1 wherein the outer heat sealable layer of the second film comprises a blend of ethylene vinyl acetate copolymer and an antiblocking agent master batch.
Claim 12
Dependent Claim
36 words
A multilayer laminate according to claim 10 wherein the outer heat sealable layer of the second film comprises a blend of about 80% ethylene vinyl acetate copolymer and about 20% of an antiblocking agent master batch.
Claim 13
Independent Claim
53 words
A method of making a multilayer laminate comprising: (a) providing a perforated film comprising a propylene homopolymer or copolymer; (b) coextruding a second film having a bonding layer of ethylene vinyl acetate copolymer and an outer heat sealable layer; and (c) bonding the bonding layer of the second film to the perforated film.
Claim 14
Independent Claim
53 words
A method of making a multilayer laminate comprising: (a) providing a perforated film comprising a propylene homopolymer or copolymer; (b) coextruding a second film having a bonding layer of ethylene vinyl acetate copolymer and an outer heat sealable layer; and (c) bonding the bonding layer of the second film to the perforated film.
Claim 15
Dependent Claim
29 words
A method according to claim 12 wherein the coextruded film is corona treated at its bonding surface and then bonded at its corona treated surface to the perforated film.
References Cited (Backward Citations)
US3558330A
Cited
JPS5119081A
Cited
US4178401A
Cited
US4439478A
Cited
EP0178218A1
Cited
US4657610A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |