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US3773882A
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Method for multilayer coextrusion
Assignee: Dow Chemical Co
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Filing: 1971-10-01
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Granted: 1973-11-20
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Expires: 1991-10-01
Abstract
Abstract Multilayer coextrusion method is shown which provides a relatively easily obtained symmetry control of the layer thickness which is particularly suitable when the desired laminate contains many layers wherein streams of first and second thermoplastic material are divided into substreams with the resulting substreams being combined at locations which are generally disposed on an arc of a circle with the interdigitated substreams being thereafter deformed by inward flow to a discharge location generally disposed at the center of the said circle.
Inventors
- 👤 W Schrenk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:43
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/30; B29C48/305; B29C48/307; B29C48/03; B29C48/07; B29C48/08; B29C48/16; B29C48/18; B29C48/21
Claims Analysis
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References Cited (Backward Citations)
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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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |