Process for producing self-bonded webs of non-woven carbon fibers

Abstract

Self-bonded webs of non-woven carbon fibers in the form of blankets, felt, paper, fiberboard, and the like, are produced by spinning a carbonaceous pitch having a mesophase content of from about 40 percent by weight to about 90 percent by weight to form carbonaceous pitch fiber; disposing staple lengths of the spun fiber in intimately contacting relationship with each other in a non-woven fibrous web; heating the web produced in this manner in an oxidizing atmosphere to thermoset the surfaces of the fibers to an extent which will allow the fibers to maintain their shape upon heating to more elevated temperatures but insufficient to thermoset the interior portions of the fibers; heating the web containing the externally thermoset fibers under compressive pressure in an oxygen-free atmosphere to a temperature sufficiently elevated to cause the mesophase pitch in the unoxidized interior portions of the fibers to undergo liquid flow and exude through surface pores or flaws in the fibers and contact the surfaces of the adjacent fibers; and further heating the web to a carbonizing temperature in an oxygen-free atmosphere so as to expel hydrogen and other volatiles and produce a carbon body wherein the fibers are bonded to each other by infusible carbon bonds.

Dependencies are inferred from the claim text.