| abstract |
A polytrimethylene terephthalate fiber, a methodnfor producing the same, a cheese-shaped package formednthereof, a false-twist textured yarn using the fibernand a fabric using the false-twist textured yarn arenprovided. The fiber is composed of 90 mol% or more ofntrimethylene terephthalate repeating units having andensity in a range from 1.320 to 1.340 g/cm 3 , anbirefringence in a range from 0.030 to 0.070, a peaknvalue of thermal stress in a range from 0.01 to 0.12ncN/dtex, a boiling water shrinkage in a range from 3 ton40%, and an elongation at break in a range from 40 ton140%. The inventive polytrimethylene terephthalate fibernhas both of proper crystallinity and orientation and isnfree from the package tightness due to yarn shrinkagenand the bulge. The inventive fiber can be produced onnan industrial scale. |