To provide a method by which a combined filament yarn having a difference in shrinkage between respective filaments constituting the combined filament yarn is large and suitable for providing a woven or a knitted fabric excellent in a touch feeling and a visual feeling and color tone can stably be produced at a low cost.
Another kind of a polymer in an amount of 0.3-5.0 wt.% is added into a polyester and the resultant mixture is then melt discharged from the same pack to provide a yarn group comprising the spun polyester multifilaments. The resultant yarn group is cooled to the glass transition temperature or below once and then divided into two groups and one of the yarn groups in an opened state is subjected to a noncontact heat treatment with an atmosphere at ≥120°C. The other yarn group is kept in a state without carrying out the heat treatment. The respective yarn groups are simultaneously taken off at ≥2,500 m/min speed, doubled and subjected to a filament combining treatment.
NAGAMUNE KEIJI
IWASHITA KENJI