PRODUCTION OF VOID-CONTAINING POLYESTER FIBER WITH UNEVENNESS

PURPOSE:To obtain in high productivity the titled fiber with durability, having excellent animal hair-like form and touch, by incorporating polyester chips with silicone oil and an organic foaming agent to carry out melt spinning followed by drawing. CONSTITUTION:Polyester chips are incorporated with (A) 0.05-0.15wt.% of silicone oil (pref. of dimethylsiloxane structure) and (B) 0.1-0.5wt.% of an organic foaming agent (e.g., azodicarbonamide) to carry out melt spinning followed by drawing, thus obtaining the objective fiber with a fineness variation 20-50% in the longer direction, having numerous closed voids therein with its average hollow degree 15-30%. In carrying out the melt spinning, it is recommended that after a melt extruder is charged with said raw materials, the temperature of the feed section be kept at 150-200 deg.C lower than the decomposition point of the organic foaming agent to retard the decomposition of said foaming agent along with preventing the decomposed gas from dispersion.