US4824720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coalesced polyolefin foam having exceptional cushioning properties
Assignee: Dow Chemical Co
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Filing: 1988-02-11
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Granted: 1989-04-25
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Expires: 2008-02-11
Abstract
Abstract Improved closed cell foams particularly suitable for use in packaging applications comprising a plurality of coalesced strands or profiles of a foamed thermoplastic composition.
Inventors
- 👤 Bruce A. Malone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:40
CPC Classifications
H; H05; H05K; H05K1/00; B; B29; B29C; B29C44/00; B29C44/34; B29C44/36; B29C44/46; B29C44/468; C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/14; B29K; B29K2023/00; B29K2023/04; B29K2023/08; B29K2023/083; B29K2025/00; B29K2105/00; B29K2105/04; B29K2105/043; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
A closed cell foam structure comprising a plurality of coalesced extruded strands or profiles of a foamed thermoplastic composition comprising a copolymer of ethylene and an ethylenically unsaturated comonomer or a blend of two or more nonaromatic olefin polymers characterized in that the heat seal strength of a film of the thermoplastic composition is at least 3.0 Newtons/ inch width and provided further that the foam structure has a gross density from about 0.1 o about 5.0 lbs/ft 3 and the strands or profiles are disposed in substantially parallel arrangement to the longitudinal axis of the foam.
Claim 2
Dependent Claim
97 words
A closed cell foam structure comprising a plurality of coalesced extruded strands or profiles of a foamed thermoplastic composition comprising a copolymer of ethylene and an ethylenically unsaturated comonomer or a blend of two or more nonaromatic olefin polymers characterized in that the heat seal strength of a film of the thermoplastic composition is at least 3.0 Newtons/ inch width and provided further that the foam structure has a gross density from about 0.1 o about 5.0 lbs/ft 3 and the strands or profiles are disposed in substantially parallel arrangement to the longitudinal axis of the foam.
Claim 3
Dependent Claim
53 words
A foam according to claim 1, wherein a two inch thick sample has dynamic cushioning properties such that objects inducing static loads of from about 0.15 to about 0.4 lbs/in 2 dropped from a height of about 24 inches at the earth's surface experience a peak deceleration of less than about 55 G's.
Claim 4
Dependent Claim
39 words
A foam according to claim 2, wherein the peak deceleration (G's) in the range of static loadings (SL) from about 0.15 to about 0.4 lb/in 2 is less than or equal to the value generated by the formula G's=20.7+31.1(SL)+4.3/SL.
Claim 5
Dependent Claim
20 words
A foam according to claim 1 having a gross density of from about 0.2 to about 3.0 lbs/ft 3 .
Claim 6
Dependent Claim
19 words
A foam according to claim 4 having a gross density from about 0.5 to about 2.8 lbs/ft 3 .
Claim 7
Dependent Claim
22 words
A foam according to claim 1, having strands or profiles of a local density from about 0.5 to 6.0 lbs/ft 3 .
Claim 8
Dependent Claim
22 words
A foam according to claim 6, having strands or profiles of a local density from about 1.0 to 3.0 lbs/ft 3 .
Claim 9
Dependent Claim
19 words
A foam according to claim 1, wherein the thermoplastic composition copmprises a copolymer of ethylene and a polar comonomer.
Claim 10
Dependent Claim
55 words
A foam according to claim 8, wherein the thermoplastic composition is selected from the group consisting of copolymers of ethylene and acrylic acid and ionomeric derivatives thereof; ethylene/vinyl acetate copolymers; copolymers of ethylene and an α-olefin having ultra low density; blends of the forgoing resins; and blends of the forgoing resins with low density polyethylene.
Claim 11
Dependent Claim
36 words
A foam according to claim 1, wherein the strands are each approximately 0.5 to about 10.0 mm in the largest cross-sectional dimension, or the profiles are each approximately 0.5 to about 10.0 mm in cross-sectional thickness.
Claim 12
Dependent Claim
35 words
A foam according to claim 10, wherein the strands are each about 1.0 to 5.0 mm in the largest cross-sectional dimension, or the profiles are each approximately 1.0 to about 5.0 mm in cross-sectional thickness.
Claim 13
Dependent Claim
11 words
A foam according to claim 1 additionally comprising a crosslinking agent.
Claim 14
Dependent Claim
14 words
A foam according to claim 1, wherein the strands have a non-circular cross-sectional shape.
Claim 15
Dependent Claim
19 words
A foam according to claim 12, wherein the strand's cross-sectional shape is that of a star, cross or X.
Claim 16
Dependent Claim
27 words
A foam according to claim 1 wherein the profiles when coalesced describe in cross-section a repeating structure containing voids having the shape of polygons or closed curves.
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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) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |