Patent US3862334A successfully refreshed from Google Patents.
US3862334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing carbon fibres
Assignee: UK Secretary of State for Defence
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Filing: 1969-06-04
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Granted: 1975-01-21
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Expires: 1989-06-04
Abstract
Abstract In the manufacture of carbon fibre a process is proposed in which a polymeric fibre is firstly heated to a temperature in the range 200* - 300* C in an inert atmosphere for a predetermined time, secondly heated to a temperature in the range 150* - 250* C in an oxygen containing atmosphere for a predetermined time, and subsequently pyrolysed. Using this two-stage preoxidation the exothermic nature of the reaction is reduced.
Inventors
- 👤 William N Turner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:10
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
34 words
A method as claimed in claim 1 and in which the pyrolysis of the fibre is effected by heating the fibre in an inert atmosphere to a temperature in the range 800* to 1500*C.
Claim 2
Dependent Claim
32 words
A method as claimed in claim 2 and in which the pyrolysis of the fibre is effected by heating the fibre to a temperature of about 1,000*C in an atmosphere of nitrogen.
Claim 3
Dependent Claim
47 words
A method as claimed in claim 1 in which said first heating step comprises heating the fibre for 3 hours at 210* C, 2 hours at 220* C, and 2 hours at 250* C in an atmosphere of nitrogen, during which time an exothermic reaction takes place.
Claim 4
Dependent Claim
38 words
A method as claimed in claim 1 and in which said second heating step comprises heating the fibre in air at a temperature of 220* C for 7 hours during which time an additional exothermic reaction takes place.
References Cited (Backward Citations)
US3285696A
Cited
US3412062A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |