POTENTIALLY HIGHLY-CRIMPABLE POLYESTER-BASED CONJUGATE FIBER

摘要

PROBLEM TO BE SOLVED: To obtain a potentially highly-crimpable polyester-based conjugate fiber having stable operability and exhibiting excellent stretch-back property and bulkiness when applied to woven and knit fabrics by selecting a copolymer PET and PET having a proper melt viscosity difference therebetween at their spinning temperature, subjecting them to a conjugate spinning at a proper conjugate ratio and making the relationship between number of crimps and apparent shrinkage proper. SOLUTION: This potentially highly-crimpable polyester-based conjugate fiber is characterized by that the melt viscosity difference between the copolymer PET component and the PET component [Wa-Wb] satisfies the following formula (a) at 260-290 deg.C spinning temperature (T) and the above two components are conjugated into a side-by-side type at a ratio (35:65) to (65:35) and satisfy the following formula (b) and (c). (a) -2.72T+993<=[Wa-Wb]<=-1.61T+5,900 (b) 1.01X+31<=Y<=0.73X+55 (c) 10<=X<=35 X: number of crimps after boiling water treatment (/cm) and Y: apparent shrinkage (%).