US4183435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymeric multiple-layer sheet material
Assignee: Champion International Corp
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Filing: 1978-08-24
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Granted: 1980-01-15
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Expires: 1998-08-24
Abstract
Abstract A polymeric multiple-layer sheet material particularly suited for making containers for food products to be cooked or reheated in microwave ovens has a relatively thick core layer of foamed, high density polyethylene with thinner surface layers of a coextruded polyester, such as polyethylene terephthalate. The surface layers are preferably bonded to the core by suitable adhesive layers.
Inventors
- 👤 Kenneth P. Thompson
- 👤 Richard C. Ihde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:39
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B5/00; B32B5/18; B32B27/36; B32B37/00; B32B37/14; B32B37/15; B32B37/153; B32B7/00; B32B7/04; B32B7/12; B65; B65D; B65D1/00; B65D1/34; B65D81/00; B65D81/34; B65D81/3446; B29; B29C; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/16; B29C48/18; B29C48/21; B29C48/22; B32B2266/00; B32B2266/02; B32B2266/0214; B32B2266/025; B32B2307/00; B32B2307/30; B32B2307/31; B32B2367/00; B32B2439/00; B32B2439/02; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249982; Y10T428/249987; Y10T428/249991; Y10T428/249992
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
64 words
A multiple-layer sheet material from which containers adapted to heat food in microwave ovens may be erected, said sheet material comprising a core layer of foamed, high density polymeric material selected from the group consisting of high density polyethylene and polypropylene, and surface layers on both sides of said core layer, each of said surface layers being a relatively thin layer of polyethylene terephthalate.
Claim 2
Dependent Claim
64 words
A multiple-layer sheet material from which containers adapted to heat food in microwave ovens may be erected, said sheet material comprising a core layer of foamed, high density polymeric material selected from the group consisting of high density polyethylene and polypropylene, and surface layers on both sides of said core layer, each of said surface layers being a relatively thin layer of polyethylene terephthalate.
Claim 3
Dependent Claim
22 words
A multiple-layer sheet material as recited in claim 1 further including adhesive layers for bonding said core layer to said surface layers.
Claim 4
Dependent Claim
23 words
A multiple-layer sheet material as recited in claim 2 wherein the material is formed by coextrusion of the core layer and surface layers.
Claim 5
Dependent Claim
23 words
A multiple-layer sheet material as recited in claim 1 wherein the material is formed by coextrusion of the core layer and surface layers.
Claim 6
Dependent Claim
25 words
A multiple-layer sheet material as recited in claim 1 wherein the material is formed by heat sealing of the surface layers to the core layer.
Claim 7
Dependent Claim
80 words
A tray suitable for use in a microwave oven comprising: a bottom wall panel; and a plurality of side wall panels connected to the edges of said bottom wall panel and extending generally upright therefrom, each of said panels being made of a multiple-layer sheet material comprising a core layer of foamed, high density polymeric material selected from the group consisting of high density polyethylene and polypropylene, having each surface covered by a relatively thin surface layer of polyethylene terephthalate.
Claim 8
Dependent Claim
80 words
A tray suitable for use in a microwave oven comprising: a bottom wall panel; and a plurality of side wall panels connected to the edges of said bottom wall panel and extending generally upright therefrom, each of said panels being made of a multiple-layer sheet material comprising a core layer of foamed, high density polymeric material selected from the group consisting of high density polyethylene and polypropylene, having each surface covered by a relatively thin surface layer of polyethylene terephthalate.
Claim 9
Dependent Claim
20 words
A tray as recited in claim 6 further including adhesive layers for bonding said core layer to said surface layers.
Claim 10
Dependent Claim
22 words
A tray as recited in claim 7 wherein the sheet material is formed by coextrusion of the core layer and surface layers.
Claim 11
Dependent Claim
24 words
A tray as recited in claim 7 wherein the sheet material is formed by heat sealing of the surface layers to the core layer.
Claim 12
Dependent Claim
22 words
A tray as recited in claim 6 wherein the sheet material is formed by coextrusion of the core layer and surface layers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-14 | 1983-07-16 | 1984-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-14 | 1987-07-16 | 1988-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-14 | 1991-07-16 | 1992-01-15 | $7700.00 | Window Closed / Lapsed |