US3574806A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing flattened sheeting or flattened tubing of molten thermoplastic resins circumferential chill casting
Assignee: Chevron USA Inc
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Filing: 1967-09-07
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Granted: 1971-04-13
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Expires: 1987-09-07
Abstract
Abstract METHOD FOR PRODUCING POLYMER FILM BY EXTRUDING A POLYMER FROM A RADIAL DIE TO FORM FILM TUBING, COOLING THE EXTRUDED POLYMER FILM TUBING OVER AN ARCUATE, SHOULDER-SHAPED HEATED MANDREL WHILE THE POLYMER FILM TUBING IS SUPPORTED BY A THIN LAYER OF MOVING AIR, THEN FURTHER COOLING THE POLYMER FILM TUBING BY CONTACTING THE TUBING WITH A COOLED POROUS MANDREL WHICH HAS INTERNAL VACUUM TO CREATE INTIMATE CONTACT, THENSLITTING THE TUBING, BLOWING AIR INTO THE OPENING CAUSED BY THE SLIT, AND CAUSING THE SLIT TUBING TO LAY FLAT WITH A WEDGE-SHAPED TUBING OPENER, THEN FINALLY WINDING UP THE FLAT SHEET INTO ROLLS.
Inventors
- 👤 Willis A Potter
- 👤 Richard L Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:30
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/90; B29C48/901; B29C48/902; B29C48/03; B29C48/09; B29C48/10; B29C48/001; B29C48/0017; B29C48/0018; B29C48/0019
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) | 1974-04-12 | 1974-10-12 | 1975-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-12 | 1978-10-12 | 1979-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-12 | 1982-10-12 | 1983-04-13 | $7700.00 | Window Closed / Lapsed |