US4064214A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making polytetrafluoroethylene yarn
Assignee: EIDP Inc
•
Filing: 1975-09-22
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Granted: 1977-12-20
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Expires: 1995-09-22
Abstract
Abstract A process for forming polytetrafluoroethylene yarn by 1. forming an oriented polytetrafluoroethylene film by drawing a sintered sheet from about 5 to 30 times its original length at an elevated temperature; and 2. passing the oriented film through fibrillating means such as a high turbulent air velocity jet to form a yarn of entangled irregular shaped non-uniform staple fibrils. The yarn and woven, non-woven and knitted fabrics prepared from this yarn also are part of the invention.
Inventors
- 👤 Emerson B. FitzGerald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:49
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/08; D01F6/12; B; B29; B29C; B29C55/00; B29C55/02; B29C55/04; B29C55/06; D01D; D01D5/00; D01D5/42; Y; Y10; Y10S; Y10S264/00; Y10S264/47
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
87 words
A process for forming a polytetrafluoroethylene yarn which comprises 1. forming an oriented film consisting of polytetrafluoroethylene having a tensile strength of 50,000-100,000 pounds per square inch by drawing a sintered polytetrafluoroethylene sheet at a temperature of about 340°-400° C. from about 5 to 30 times its original length; 2. passing the oriented film through a fibrillating means comprising a jet through which a high velocity fluid is passed and is impinged upon the oriented film thereby forming a yarn of entangled irregularly shaped non-uniform staple fibrils.
Claim 2
Dependent Claim
87 words
A process for forming a polytetrafluoroethylene yarn which comprises 1. forming an oriented film consisting of polytetrafluoroethylene having a tensile strength of 50,000-100,000 pounds per square inch by drawing a sintered polytetrafluoroethylene sheet at a temperature of about 340°-400° C. from about 5 to 30 times its original length; 2. passing the oriented film through a fibrillating means comprising a jet through which a high velocity fluid is passed and is impinged upon the oriented film thereby forming a yarn of entangled irregularly shaped non-uniform staple fibrils.
Claim 3
Dependent Claim
11 words
The process of claim 1 in which the fluid is air.
Claim 4
Dependent Claim
41 words
The process of claim 2 in which a 2-5 mil thick non-sintered polytetrafluorethylene film is used and is sintered at about 340°-400° C. and immediately thereafter is drawn at 10-20 times its original length at a temperature of about 340°-400° C.
Claim 5
Dependent Claim
12 words
The process of claim 3 in which the yarn is 100-2000 denier.
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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) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |