Process for continuous graphitization of graphitizable precursor fibers
AssigneeToray Industries, Inc.
InventorsRyuichi Yamamoto, Shizuo Watanabe
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Abstract
An improved process for manufacturing high-grade and high-quality graphite fibers by the steps of (a) heating carbon fibers from acrylic fibers in an initial heating zone while exposed to an atmosphere of inert gas having a maximum temperature from about 1700.degree. C. to 1900.degree. C., and (b) then heating the resulting fibers in a subsequent heating zone while exposed to an atmosphere of inert gas having a maximum temperature from 2300.degree. C. to 2700.degree. C.
Claims6
A process for continuously graphitizing a carbon fiber obtained from an acrylic fiber consisting essentially of at least about 95 mol % of acrylonitrile and up to about 5 mol % of one or more ethylene-type vinyl compounds which are copolymerizable with acrylonitrile which comprises passing the fiber successively through a first and a separate second heating zone, each of said zones containing an inert atmosphere and having a temperature of at least 800.degree. C., maintaining the maximum temperature of the first heating zone at about 1700.degree. to about 1900.degree. C., a heating rate which is a mean heating rate of from about 1300.degree. C. to the maximum temperature minus 100.degree. C. at about 300.degree. C./min to 2000.degree. C./min, and a heating time of about 10 seconds to 10 minutes, and maintaining the maximum temperature of the second heating zone at about 2300.degree. C. to about 2700.degree. C.
Dependencies are inferred from the claim text.