COMPOSITE POLYESTER COMBINED FILAMENT YARN HAVING LOW SHRINKAGE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a composite polyester combined filament yarn having low shrinkage, having thick-thin unevenness in the longitudinal direction of yarn, excellent in drapability and springiness and suitable as yarn for a woven or knit fabric exhibiting natural mottle appearance and to provide a method for producing the yarn. ;SOLUTION: This combined filament yarn is constituted of single filaments, in which thick parts a₁ and thin parts a₂ are unevenly formed in the longitudinal direction, and a variation ratio of the cross sections of the thick part a₁ and the thin part a₂ is ≤1.3. The combined filament yarn is composed of polyester high-elongation low-shrinkage yarns A having low torque and polyester low-elongation non-shrinking yarns B. Further, boiling-water shrinkage- percentages and heat-shrinkage stresses of the yarn A and the yarn B satisfy the following relations (1) and (2). (1): Boiling-water shrinkage-percentages of the yarn A and the yarn B are ≤5% and ≥5%, respectively, and the boiling-water shrinkage-percentage of the yarn B minus that of the yarn A is ≥3%. (2): Heat-shrinkage stresses of the yarn A and the yarn B are ≤0.1g/d and ≥0.1g/d, respectively. Furthermore, loosely entangled parts P and densely entangled parts S each having an irregular length are formed in the longitudinal directions of the combined filament yarn, and the coefficient of variation of the lengths of the entangled parts P and S is 20-100%.;COPYRIGHT: (C)1997,JPO