Patent US2791806A successfully refreshed from Google Patents.
US2791806A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion of polytetrafluoroethylene at temperatures above the normal melting point
Assignee: EIDP Inc
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Filing: 1953-08-21
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Granted: 1957-05-14
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Expires: 1973-08-21
Abstract
No abstract record available.
Inventors
- 👤 John P Tordella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:12
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/03; B29C48/022; B29K; B29K2027/00; B29K2027/12; B29K2027/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
67 words
A PROCESS FOR EXTRUDING SUBSTANTIALLY PURE UNBAKED POLYTETRAFLUOROETHYLENE WHICH COMPRISES SUBJECTING THE SAID POLYTETRAFLUOROETHYLENE IN AN EXTRUDER AT A TEMPERATURE ABOVE ITS ATMOSPHERIC PRESSURE MLTING POINT TO A CONTROLLED PRESSURE SUFFICIENT TO RESTRAIN THE MELTING OF THE SAID POLYTETRAFLUOROETHYLENE, FORCING THE SAID POLYTETRAFLUOROETHYLENE INTO A DIE AT THE SAID PRESSURE AND TEMPERATURE, AND PERMITTING THE PRESSURE ON THE POLYTETRAFLUOROETHYLENE TO DECREASE AS IT PASSES THROUGH THE SAID
Claim 2
Dependent Claim
67 words
A PROCESS FOR EXTRUDING SUBSTANTIALLY PURE UNBAKED POLYTETRAFLUOROETHYLENE WHICH COMPRISES SUBJECTING THE SAID POLYTETRAFLUOROETHYLENE IN AN EXTRUDER AT A TEMPERATURE ABOVE ITS ATMOSPHERIC PRESSURE MLTING POINT TO A CONTROLLED PRESSURE SUFFICIENT TO RESTRAIN THE MELTING OF THE SAID POLYTETRAFLUOROETHYLENE, FORCING THE SAID POLYTETRAFLUOROETHYLENE INTO A DIE AT THE SAID PRESSURE AND TEMPERATURE, AND PERMITTING THE PRESSURE ON THE POLYTETRAFLUOROETHYLENE TO DECREASE AS IT PASSES THROUGH THE SAID
References Cited (Backward Citations)
US2456621A
Cited
US2485691A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-05-13 | 1960-11-12 | 1961-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-05-13 | 1964-11-12 | 1965-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-05-13 | 1968-11-12 | 1969-05-14 | $7700.00 | Window Closed / Lapsed |