Patent US3769379A successfully refreshed from Google Patents.
US3769379A
Expired / Lapsed
US
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Apparatus for the method of making plastic film
Assignee: Reynolds Metals Co
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Filing: 1971-03-22
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Granted: 1973-10-30
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Expires: 1991-03-22
Abstract
Abstract Plastic film is made using a heat transfer liquid circulated through the film extrusion die to control (by either heating or cooling, as required) the temperature of the plastic melt flowing through such die. A plastic bubble emerging at the outlet of the die is inflated and ventilated by continuously circulated gas which is controlled in temperature as it enters and leaves the bubble so that it does not adversely affect the temperature of the melt in the die.
Inventors
- 👤 D Hinrichs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:56
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/78; B29C48/86; B29C48/87; B29C48/03; B29C48/09; B29C48/10; B29C48/30; B29C48/32; B29C48/80; B29C48/802; B29C48/865
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |