PURPOSE: In subjecting an acrylic polymer to wet spinning, to obtain in high yield, yarn having pilling resistance, cross section close to a circle, and high added value, by limiting a concentration of spinning solution, concentration of a solvent in a coagulating bath, draft ratio, draw ratio, etc. to specific ranges.
CONSTITUTION: In producing yarn having pilling resistance and ≥0.6 index of circularity shown by the formula by subjecting an acrylic polymer containing ≥94wt% acrylonitrile unit, a spinning stock solution having 20W25wt% polymer concentration is extruded into a coagulating bath containing at least 55wt% solvent for the polymer, spun at 0.6W1.2 draft ratio, drawn at 4W5.5 times draw ratio, densified to make ≤5% shrinkage during drying and densification, and, then heat-treated under tension of at least 160°C.
TANAKA HIROYOSHI
FUJII SHIGERU
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