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US4521359A
Expired / Lapsed
US
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Method of coextruding plastics to form a composite sheet
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1981-12-04
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Granted: 1985-06-04
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Expires: 2001-12-04
Abstract
Abstract This invention pertains to a method of producing a composite sheet of plastic materials by means of coextrusion. Two plastic materials are matched with respect to their melt indices. These matched plastic materials are then coextruded in a side-by-side orientation while hot and soft to form a composite sheet having a substantially uniform demarkation therebetween. The plastic materials are fed at a substantially equal extrusion velocity and generally have substantially equal viscosities. The coextruded plastics can be worked after coextrusion while they are still hot and soft.
Inventors
- 👤 Hsue C. Tsien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:15
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/16; B29C48/18; B29C48/19; B29C48/03; B29C48/07; B29C48/08; B29C48/12; B29C59/00; B29C71/00; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/10; B29K2023/12; B29L; B29L2031/00; B29L2031/34; B29L2031/3468
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
55 words
A method of producing a composite sheet of dissimilar plastic materials, comprising the steps of: (a) matching at least two dissimilar plastic materials with respect to their melt indices; and (b) coextruding said matched plastic materials with a side-by-side orientation while hot and soft to form a composite sheet having a substantially uniform demarcation therebetween.
Claim 2
Independent Claim
55 words
A method of producing a composite sheet of dissimilar plastic materials, comprising the steps of: (a) matching at least two dissimilar plastic materials with respect to their melt indices; and (b) coextruding said matched plastic materials with a side-by-side orientation while hot and soft to form a composite sheet having a substantially uniform demarcation therebetween.
Claim 3
Dependent Claim
19 words
The method of claim 1, wherein in said coextruding step (b), said plastic materials have substantially equal extrusion velocities.
Claim 4
Dependent Claim
13 words
The method of claim 1, wherein said plastic materials have substantially equal viscosities.
Claim 5
Dependent Claim
26 words
The method of claim 1, further comprising the step of: (c) working at least one of said plastic materials while still hot and soft after coextrusion.
Claim 6
Dependent Claim
16 words
The method of claim 4, wherein said working step (c) includes pinching at least one plastic.
Claim 7
Dependent Claim
16 words
The method of claim 4, wherein said working step (c) includes dimpling at least one plastic.
Claim 8
Dependent Claim
21 words
The method of claim 1, further comprising the step of: (c) coating at least one of said plastic materials after coextrusion.
Claim 9
Dependent Claim
22 words
The method of claim 1, wherein said matching step (a) includes minimizing differences in melt flow indices between each dissimilar plastic material.
Claim 10
Dependent Claim
24 words
The method of claim 1, wherein said coextruding is conducted at speeds in an approximate range of from 20 to 90 feet per minute.
Claim 11
Dependent Claim
15 words
The method of claim 1, wherein at least one of said plastic materials comprises polyethylene.
Claim 12
Dependent Claim
15 words
The method of claim 1, wherein at least one of said plastic materials comprises polypropylene.
Claim 13
Dependent Claim
17 words
The method of claim 1, wherein at least one of the plastic materials comprises a conductive plastic.
Claim 14
Dependent Claim
20 words
The method of claim 1, wherein at least one of the plastic materials comprises a copolymer of polypropylene and polyethylene.
Claim 15
Dependent Claim
16 words
The method of claim 1, wherein at least one of the plastic materials comprises a polyolefin.
Claim 16
Dependent Claim
17 words
The method of claim 1, wherein said coextruding is achieved at a approximate temperature above 375° F.
Claim 17
Dependent Claim
20 words
The method of claim 1, wherein said coextruding is achieved in an approximate pressure range from 1,500 to 1,800 psi.
References Cited (Backward Citations)
US1476392A
Cited
US1978163A
Cited
US2696640A
Cited
US3276943A
Cited
GB1167551A
Cited
US3532570A
Cited
US3629037A
Cited
US3557262A
Cited
US3849051A
Cited
US4055526A
Cited
US4105829A
Cited
US4152387A
Cited
US4169816A
Cited
US4197169A
Cited
DE2853850A1
Cited
US4272471A
Cited
US4272312A
Cited
US4277317A
Cited
US4312735A
Cited
US4279732A
Cited
US4285794A
Cited
US4259417A
Cited
US4286027A
Cited
US4293623A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-03 | 1988-12-03 | 1989-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-03 | 1992-12-03 | 1993-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-03 | 1996-12-03 | 1997-06-04 | $7700.00 | Window Closed / Lapsed |