Process for producing carbon fibers
US4069297A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1976 |
| Grant date | Jan 17, 1978 |
| Priority date | — |
| Expiry date | Apr 6, 1996 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F9/32
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A process for continuously producing carbon fibers which comprises preoxidizing polyacrylonitrile fibers containing at least about 90% by weight of acrylonitrile at a temperature of about 200.degree. to about 300.degree. C in an oxidizing atmosphere while allowing the fibers to shrink about 40 to about 70% (of the free shrinkage of the fibers determined under a load of 1 mg/d) with the progress of preoxidation; then carbonizing the preoxidized fibers at about 500.degree. to about 1,000.degree. C in a non-oxidizing atmosphere so that the shrinkage of the fibers finally becomes about 40 to about 70% (of the free shrinkage of the preoxidized fibers determined when the fibers are placed under a load of 1 mg/d and heated at 1,000.degree. C for 15 minutes); and then heat treating the carbonized fibers at constant length at a temperature of up to about 3,000.degree. C in a non-oxidizing atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.