Mfg false twisted or modified false twisted polyester yarns

摘要

False twisted polyester yarn has a bulk density of of from 1.380 to 1.395g 1 cc and a total crimping percentage (TC) of >=30%. Modified false twisted yarn has equal bulk density but TC of >=20% and a torque of =26 twists per 25 cm. Yarns are produced by using a tow of yarns having a double refractive index varying between 0.030 and 0.145, false twisting the tow, fixing it at a temp. of from 160 to 210 degrees C and stretching the false twisted and fixed tow to obtain a stretch dt satisfying the condition -250 DELTA n + 38 >= (dr) >=-150 DELTA n + 17.