POLYESTER THICK AND THIN YARN AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a polyester thick and thin yarn assuming a moire appearance in which deep dyed parts are long and the deep dyed parts are exhibited at a low frequency without period. SOLUTION: This polyester thick and thin yarn is characterized as simultaneously satisfying the following (1) to (3). (1)>=8.0% Uster normal value (U% value), (2) >=1 and <=5 number of thickness fluctuation peaks having >=10% U% value/m and >=80 mm average length of thick parts and (3) parts having 15-40×10-3 birefringenceΔn and parts having 50-80×10-3 birefringenceΔn alternately present in a single filament constituting the thick and thin yarn.