4816195 Process of making a loosely formed non-woven mat of aligned carbon fibers

Abstract

A large number of melt blown carbon fibers from petroleum pitch through a multi-orifice die under continuous formation, are fed onto the periphery of a continuously moving endless conveyor surface whose surface speed is matched to the linear velocity of the melt blown carbon fibers to cause the fibers to be deposited in parallel alignment on the conveyor surface and to be maintained in fiber axial alignment to form a non-woven mat of aligned carbon fibers. The speed of the conveyor surface may be slightly less than the linear speed of the fibers to form a loose fiber mat to facilitate subsequent fiber oxidation and carbonization by permitting gas flow through the aligned fiber mat. The endless conveyor may comprise a cylindrical drum whose surface is perforated to facilitate gas flow and oxidation of the carbon fibers subsequent to non-woven mat formation. The drum circumference may be set to the desired fiber length and the mat severed transversely to permit removal of the aligned fibers of desired length in bundle form.