ACRYLIC YARN AS THICK CARBON FIBER PRECURSOR AND METHOD FOR PRODUCING THE SAME

摘要

A method for producing an acrylic yarn as a precursor of a thick carbon fiber wherein an acrylonitrile polymer is spun out and then the resultant swollen yarn is dried to produce a fine yarn, characterized in that the width of a yarn is controlled by introducing an swollen yarn (1) by using a roll (2) having striae (3), to thereby produce a thick yarn having a total fineness of 22,000 dtex or more. The method can be employed for producing an acrylic yarn as a precursor of a thick carbon fiber which can provide a high quality carbon fiber being free from problems of the irregularity in strength in the longitudinal direction thereof and the like, even when the yarn is a precursor of a thick carbon fiber having a large total fineness.