US2786792A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making polytetrafluoro-ethylene articles
Assignee: 3M Co
•
Filing: 1953-05-06
•
Granted: 1957-03-26
•
Expires: 1973-05-06
Abstract
No abstract record available.
Inventors
- 👤 William F Mikiska
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:12
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/04; B32B15/08; F; F42; F42B; F42B5/00; F42B5/38; Y; Y10; Y10S; Y10S383/00; Y10S383/908; Y10S417/00; Y10S417/01
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
114 words
THE METHOD OF MAKING A FLEXIBLE POLYTETRAFLUOROETHYLENE FILM ENVELOPE WHICH COMPRISES: ASSEMBLING TOGETHER IN STACK FORM A PLURALITY OF LAYERS OF SOFT, POROUS, UNSINTERED, LUBRICANT-FREE POLYTETRAFLUOROETHYLENE FILM AND, BETWEEN EACH TWO ADJOINING LAYERS OF SAID FILM AND IN CONTACT WITH ALL AREAS OF SAID FILM WHICH ARE DESIGNED TO BECOME FREE SURFACES OF SAID ENVELOPE, CORRESPONDING THIN LAYERS OF METAL; HEATING TH ESTACK TO A TEMPERATURE THE DENSE, NON-POROUS, STRONG, TOUGH, FLEXIBLE, SINTERED STATE AND TO CAUSE CONTACTING SURFACES OF ADJACENT LAYERS OF FILM TO COHERE AND BOND TOGETHER; COOLING THE ASSEMBLY; AND THEN OPENING AND EXPANDING SAID ENVELOPE; SAID STACK BEING MAINTAINED UNDER UNIFORM AND CONTINUOUS PRESSURE DURING SAID HEATING AND COOLING STEPS.
Claim 2
Independent Claim
114 words
THE METHOD OF MAKING A FLEXIBLE POLYTETRAFLUOROETHYLENE FILM ENVELOPE WHICH COMPRISES: ASSEMBLING TOGETHER IN STACK FORM A PLURALITY OF LAYERS OF SOFT, POROUS, UNSINTERED, LUBRICANT-FREE POLYTETRAFLUOROETHYLENE FILM AND, BETWEEN EACH TWO ADJOINING LAYERS OF SAID FILM AND IN CONTACT WITH ALL AREAS OF SAID FILM WHICH ARE DESIGNED TO BECOME FREE SURFACES OF SAID ENVELOPE, CORRESPONDING THIN LAYERS OF METAL; HEATING TH ESTACK TO A TEMPERATURE THE DENSE, NON-POROUS, STRONG, TOUGH, FLEXIBLE, SINTERED STATE AND TO CAUSE CONTACTING SURFACES OF ADJACENT LAYERS OF FILM TO COHERE AND BOND TOGETHER; COOLING THE ASSEMBLY; AND THEN OPENING AND EXPANDING SAID ENVELOPE; SAID STACK BEING MAINTAINED UNDER UNIFORM AND CONTINUOUS PRESSURE DURING SAID HEATING AND COOLING STEPS.
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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) | 1960-03-25 | 1960-09-24 | 1961-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-03-25 | 1964-09-24 | 1965-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-03-25 | 1968-09-24 | 1969-03-26 | $7700.00 | Window Closed / Lapsed |