Patent ID: 6877197

Claim:
A continuous process for treating a bicomponent polyester fiber comprising the steps of: a) providing a bicomponent fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) that has been heated to a first heat-treating temperature and cooled to a temperature below about 70° C.; wherein the fiber has an initial crimp contraction value and a developed crimp contraction value; b) applying tension to the fiber of about 0.001 to about 0.088 dN/tex; c) heat-treating the tensioned fiber at a second heat-treating temperature that is no lower than about 75° C. and no higher than the first heat-treating temperature; d) cooling the fiber to lower than the second heat-treating temperature; e) releasing the tension from the fiber, wherein the resulting treated bicomponent fiber has a reduced crimp contraction value.