US4744857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for modifying fluoropolymer fibers
Assignee: ACTON ASSOCIATES Inc A CORP OF
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Filing: 1986-10-23
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Granted: 1988-05-17
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Expires: 2006-10-23
Abstract
Abstract The present invention provides etched fluoropolymer fibers and a method for etching fluoropolymer fibers, which are then capable of being boned either together or with other materials to form composite materials. In particle, the present invention relates to a method for chemically etching chopped, natural polytetrafluoroethylene fiber by immersing the fibers in an alkai metal polyaryl hydrocarbon etching solution with increased temperatures ranging from 50° C. to 110° C. and high shearing agitation until at least 98% of the fibers are sufficiently hydrophilic to sink when placed in water. This produces etched fiber material which may then be bonded together to form composite fluoropolymer products.
Inventors
- 👤 Kevin G. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:02
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/04; C08J5/06; D; D06; D06M; D06M11/00; D06M11/83; D06M13/00; D06M13/02; D06M13/03; D06M13/07; D06M23/00; C08J2375/00; C08J2375/04; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2904; Y10T428/2913
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
65 words
A method of etching fluoropolymer fibers comprising: (a) immersing said fibers in an alkali metal/polyaryl hydrocarbon etching solution and; (b) subjecting said fibers in said etching solution to high shear agitation which maintains said fibers at a temperature in the range of from about 50° C. to 110° C. until at least 98% of said fibers are sufficiently hydrophilic to sink when placed in water.
Claim 2
Independent Claim
65 words
A method of etching fluoropolymer fibers comprising: (a) immersing said fibers in an alkali metal/polyaryl hydrocarbon etching solution and; (b) subjecting said fibers in said etching solution to high shear agitation which maintains said fibers at a temperature in the range of from about 50° C. to 110° C. until at least 98% of said fibers are sufficiently hydrophilic to sink when placed in water.
Claim 3
Dependent Claim
11 words
The method of claim 1 in which said fiber comprises polytetrafluoroethylene.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein said fibers are about 0.02 mm to about 0.04 mm in diameter.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein said fibers are about 0.2 mm to about 0.3 mm in length.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said fibers have a tetrafluoroethylene content of about 95%.
Claim 7
Dependent Claim
14 words
The method of claim 1 wherein said etching solution is a sodium/napathalene etching solution.
Claim 8
Dependent Claim
21 words
The method of claim 1 wherein said high shear agitation is accomplished by intense mechanical mixing using a high shear mixer.
Claim 9
Dependent Claim
17 words
The method of claim 1 wherein said high shear agitiation is maintained for 6 to 10 minutes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |