PROCESS FOR PRODUCING CARBON FIBERS

摘要

When preparing carbon fibers from mesophase pitches, we usually encounter the formation of cracks along the fiber axis. The crack formation is the most serious and troublesome problem. A simple process and apparatus which can effectively prevent the crack formation are disclosed. In the process for preparing the carbon fibers from mesophase pitches by melt spinning, it is sufficient only to give a rotatory motion to the molten mesophase pitches just before extrusion substantially around the axis of a spinning nozzle hole. The apparatus is essentially the same as a usual nozzle plate having a pitch introducing tube and a spinning nozzle hole provided that the apparatus further contains a plug member having an outer spiral groove such as a drill point or a worm gear and the plug member is inserted within the pitch introducing tube.