US4551380A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oriented heat-sealable multilayer packaging film
Assignee: Cryovac LLC
•
Filing: 1984-05-10
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Granted: 1985-11-05
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Expires: 2004-05-10
Abstract
Abstract A three layered heat shrinkable, heat sealable thermoplastic packaging film having a desired combination of physical characteristics is disclosed. The film may be utilized to package a wide variety of items. A preferred embodiment of the film comprises a core layer consisting essentially of a linear low density polyethylene and two surface layers comprising a three component blend of (1) a linear low density polyethylene, (2) a linear medium density polyethylene and (3) a copolymer of ethylene and vinyl acetate.
Inventors
- 👤 Julian H. Schoenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:16
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/06; B32B27/08; B32B2250/00; B32B2250/03; B32B2250/24; B32B2250/246; B32B2270/00; B32B2305/00; B32B2305/72; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/50; B32B2307/514; B32B2307/518; B32B2307/70; B32B2307/718; B32B2307/732; B32B2307/734; B32B2307/736; B32B2323/00; B32B2323/04; B32B2323/046; B32B2553/00; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/24992; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
50 words
An oriented heat sealable multilayer film comprising: a cross-linked core layer consisting essentially of a linear low density polyethylene; and two cross-linked surface layers each comprising a three component blend of (1) a linear low density polyethylene, (2) a linear medium density polyethylene and (3) an ethylene vinyl acetate copolymer.
Claim 2
Dependent Claim
50 words
An oriented heat sealable multilayer film comprising: a cross-linked core layer consisting essentially of a linear low density polyethylene; and two cross-linked surface layers each comprising a three component blend of (1) a linear low density polyethylene, (2) a linear medium density polyethylene and (3) an ethylene vinyl acetate copolymer.
Claim 3
Dependent Claim
78 words
An oriented heat sealable three layer packaging film comprising: a cross-linked core layer consisting essentially of a linear low density polyethylene; two cross-linked surface layers each comprising a three component blend of (1) from about 40% to about 60%, by weight, of a linear low density polyethylene, (2) from about 20% to about 30%, by weight, of a linear medium density polyethylene and (3) from about 20% to about 30%, by weight, of an ethylene vinyl acetate copolymer.
Claim 4
Dependent Claim
78 words
An oriented heat sealable three layer packaging film comprising: a cross-linked core layer consisting essentially of a linear low density polyethylene; two cross-linked surface layers each comprising a three component blend of (1) from about 40% to about 60%, by weight, of a linear low density polyethylene, (2) from about 20% to about 30%, by weight, of a linear medium density polyethylene and (3) from about 20% to about 30%, by weight, of an ethylene vinyl acetate copolymer.
Claim 5
Dependent Claim
126 words
An oriented heat sealable three layer packaging film comprising: a cross-linked core layer consisting essentially of a linear low density polyethylene having a density of about 0.920 grams per cubic centimeter; and two cross-linked surface layers each consisting essentially of a three component blend of (1) about 50%, by weight, of a linear low density polyethylene having a density of about 0.920 grams per cubic centimeter, (2) about 25%, by weight, of a linear medium density polyethylene having a density of about 0.935 grams per cubic centimeter and (3) about 25%, by weight, of an ethylene vinyl acetate copolymer comprising from about 3.3% to about 4.1% vinyl acetate derived units, said copolymer having a density of from about 0.9232 to about 0.9250 grams per cubic centimeter.
Claim 6
Dependent Claim
126 words
An oriented heat sealable three layer packaging film comprising: a cross-linked core layer consisting essentially of a linear low density polyethylene having a density of about 0.920 grams per cubic centimeter; and two cross-linked surface layers each consisting essentially of a three component blend of (1) about 50%, by weight, of a linear low density polyethylene having a density of about 0.920 grams per cubic centimeter, (2) about 25%, by weight, of a linear medium density polyethylene having a density of about 0.935 grams per cubic centimeter and (3) about 25%, by weight, of an ethylene vinyl acetate copolymer comprising from about 3.3% to about 4.1% vinyl acetate derived units, said copolymer having a density of from about 0.9232 to about 0.9250 grams per cubic centimeter.
Claim 7
Dependent Claim
29 words
The film of claims 1 or 2 or 3 having longitudinal and transverse shrink/temperature curves substantially as shown in FIGS. 2 and 3 for embodiments I, II and III.
Claim 8
Dependent Claim
22 words
The film of claims 1 or 2 or 3 having longitudinal and transverse shrink values of greater than 10% at 200° F.
Claim 9
Dependent Claim
27 words
The film of claim 2 wherein said ethylene vinyl acetate copolymer comprises from about 2%, by weight, to about 18%, by weight, of vinyl acetate derived units.
Claim 10
Dependent Claim
26 words
The film of claim 2 wherein said vinyl acetate copolymer comprises from about 2%, by weight, to about 10%, by weight, of vinyl acetate derived units.
Claim 11
Dependent Claim
27 words
The film of claim 2 wherein said ethylene vinyl acetate copolymer comprises from about 2%, by weight, to about 5%, by weight, of vinyl acetate derived units.
Claim 12
Dependent Claim
29 words
The film of claims 2 or 3 having a melt flow at 230° C. and 21,600 grams load of from about 1.0 to about 10.0 grams per ten minutes.
Claim 13
Dependent Claim
29 words
The film of claims 2 or 3 having a melt flow at 230° C. and 21,600 grams load of from about 2.0 to about 5.0 grams per ten minutes.
Claim 14
Dependent Claim
25 words
The film of claims 2 or 3 having a melt flow at 230° C. and 21,600 grams load of about 3.0 grams per ten minutes.
Claim 15
Dependent Claim
23 words
The film of claims 2 or 3 having an average ball burst value of from about 17 to about 22 centimeters times kilograms.
Claim 16
Dependent Claim
22 words
The film of claims 2 or 3 having an average ball burst value of greater than from about 19 centimeters times kilograms.
Claim 17
Dependent Claim
22 words
The film of claims 2 or 3 which has been cross-linked with from about 1.0 MR to about 6.0 MR of irradiation.
Claim 18
Dependent Claim
22 words
The film of claims 2 or 3 which has been cross-linked with from about 1.5 MR to about 3.5 MR of irradiation.
Claim 19
Dependent Claim
17 words
The film of claims 2 or 3 which has been cross-linked with about 2.5 MR of irradiation.
Claim 20
Dependent Claim
31 words
The film of claims 2 or 3 which has been oriented by racking at a racking ratio of from about 3.0 to about 6.0 in both the longitudinal and transverse directions.
Claim 21
Dependent Claim
27 words
The film of claims 2 or 3 which has been oriented by racking at a ratio of greater than about 4.5 times in both the longitudinal directions.
Claim 22
Dependent Claim
31 words
The film of claims 2 or 3 which has been oriented by racking at a racking ratio of from about 4.5 to about 5.5 in both the longitudinal and transverse directions.
Claim 23
Dependent Claim
27 words
The film of claims 2 or 3 which have been oriented by racking at a racking ratio of about 5.0 in both the longitudinal and transverse directions.
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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) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |