US3764662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making carbon fiber
Assignee: General Electric Co
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Filing: 1971-04-21
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Granted: 1973-10-09
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Expires: 1991-04-21
Abstract
Abstract Carbon fibers made by a process which involves heating a polyacrylonitrile fiber to a temperature below its carbonization temperature in an oxidizing atmosphere, carbonizing the fibers in a nonoxidizing atmosphere, such that combined heat and tension is applied to the fiber during at least one of the above steps, and then heating the carbon fibers in an inert atmosphere for at least one hour at from 1,300*-1,800* C., are improved by subjecting the carbon fibers to a post-heat treatment in an inert atmosphere at elevated temperatures of about 2,300*-3,000* C. for a very short time of 30-90 seconds.
Inventors
- 👤 B Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:55
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
45 words
The process of claim 1, wherein the post-heat treatment of the carbon fiber produces alignment, growth and coalescence of the plane packets to a highly organized state as shown in FIG. 2, whereby the Young''s modulus is increased to greater than 45 X 106 psi.
References Cited (Backward Citations)
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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) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |