HEATING ELEMENT FOR SPINNING

摘要

PURPOSE:To prevent the generation and sticking of carbon fiber during spinning by forming a thermally cracked carbon film and boron nitride film successively on an artificial graphite base material to be used as a heating element for a spinning furnace of a preform method. CONSTITUTION:The artifitial graphite base material is disposed in a reactor and a hydrocarbon such as methane or propane is supplied by a carrier gas (e.g.; nitrogen) into the reaction system to heat the base material to a high temp. to cause the thermal cracking thereof, by which the thermally cracked carbon film is formed on the surface of the artificial graphite base material. The boron nitride film is then formed on the outside of the thermally cracked carbon film by a thermal CVD method using a boron source such as BCl3 or BF3 and nitrogen source such as N2 or NH3 to obtain the objective heating element for spinning. The optical fiber which is free from partial strength deterioration and dispersion of the fiber diameter is obtd. without sticking of the carbon powder to the spun optical fiber by using such heating element as the heating element for the spinning furnace by the preform method.