PRODUCTION OF CARBON FIBER AND APPARATUS FOR CENTRIFUGAL SPINNING USED THEREFOR

摘要

PURPOSE:To rapidly lower the surface temperature of discharged pitch and reduce shots, etc., by controlling the temperature near the nozzle surface to a low value. CONSTITUTION:Coal or petroleum pitch 3 is fed to a heated rotating spinning nozzle 5 and discharged from nozzle holes 7 to the outside air and form a drawn and fiberized pitch 8. Cooling air 12 is fed from cooling gas feeding nozzles 9 and 10 to keep the atmospheric temperature near the nozzle surface at a low value. the temperature of pitch discharged from the nozzle holes is kept at 200-400 deg.C and controlled so that the ratio (l/d) of the distance [l(m)] apart in the radial direction from the nozzle surface to the nozzle hole diameter [d(m)] may be within the range of 10-20 and the atmospheric temperature (t) may satisfy the relation expressed by the formula t<=Sp-K.(l/d).(T-Sp) [Sp is softening point ( deg.C) of the raw material pitch: T is the discharging temperature ( deg.C) of the pitch; K=0.013].