US4402889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Making sheet with moisture barrier properties coextruded from scrap materials
Assignee: Composite Container Corp
•
Filing: 1982-02-04
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Granted: 1983-09-06
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Expires: 2002-02-04
Abstract
Abstract Coextruding an inexpensive multilayered plastic sheet with outer layers of scrap material and a central layer of unqualified scrap having sufficient polyolefin content to provide a moisture barrier.
Inventors
- 👤 Laszlo J. Bonis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:54
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B29; B29C; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/305; B29C48/307; B29C51/00; B29C51/14; B32B7/00; B32B7/04; B32B7/12; B32B2272/00; B32B2325/00; Y; Y10; Y10S; Y10S264/00; Y10S264/911; Y10S264/92; Y10S425/00; Y10S425/046
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
82 words
A method of making an inexpensive multilayered sheet structure comprising coextruding by separately heating qualified scrap material and unqualified scrap material having sufficient polyolefin content to provide a moisture barrier, supplying said heated material to a coextrusion block to form a multilayer stream with outer layers of said qualified scrap material, and a central layer of said unqualified scrap having sufficient polyolefin content to provide a moisture barrier, and flattening said multilayer stream in a coextrusion die to produce a multilayer sheet.
Claim 2
Independent Claim
82 words
A method of making an inexpensive multilayered sheet structure comprising coextruding by separately heating qualified scrap material and unqualified scrap material having sufficient polyolefin content to provide a moisture barrier, supplying said heated material to a coextrusion block to form a multilayer stream with outer layers of said qualified scrap material, and a central layer of said unqualified scrap having sufficient polyolefin content to provide a moisture barrier, and flattening said multilayer stream in a coextrusion die to produce a multilayer sheet.
Claim 3
Dependent Claim
38 words
The method of claim 1 wherein said coextruding includes coextruding intermediate tie layers between said central layer and said outer layers of adhesive that binds with the predominant plastic in said unqualified scrap and with said qualified scrap.
Claim 4
Dependent Claim
16 words
The method of claim 1 further comprising preparing said unqualified scrap from different sources of material.
Claim 5
Dependent Claim
13 words
The method of claim 2 wherein said qualified scrap is impact resistant polystyrene.
Claim 6
Dependent Claim
13 words
The method of claim 4 wherein said unqualified scrap includes polypropylene and polystyrene.
Claim 7
Dependent Claim
25 words
The method of claim 5 wherein said sheet has a moisture permeability at 78° F., 90% humidity of about 0.02 gm/100 in 2 -24 hr.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein said unqualified scrap has more than about 10% polypropylene.
Claim 9
Dependent Claim
19 words
The method of claim 2, 3, 4, 5 or 6 further comprising thermoforming said sheet into a desired shape.
Claim 10
Dependent Claim
30 words
The method of claim 3 further comprising thermoforming said sheet into a desired shape, trimming containers from the thermoformed sheet and using the scrap plastic from trimming in said preparing.
Claim 11
Dependent Claim
46 words
The method of claim 3 wherein said inner layer of unqualified scrap has more than about 70% of one type of plastic, said outer layers are made of said one type of plastic, and said coextruding involves coextruding said inner layer directly to said outer layers.
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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) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |