Machine crimped synthetic fiber having latent three-dimensional crimpability and method for production thereof

摘要

The machine-crimped synthetic fibers of the present invention have a thickness of 0.5 to 200 dtex, a fiber length of 3 to 20 mm and the number of crimps of 1 to 13 crimps/25 mm and a crimp percentage of 2 to 20%, each fiber having two portions disproportional in thermal shrinkage with each other and located in two sides of the fiber divided by an interface by which the fiber is divided along the longitudinal axis of the fiber into two side portions, to cause the fiber to have such a latent crimping property that when heat treated at 60 to 200° C., the two side portions of the fiber disproportionally shrink and the shrunk fiber exhibits three-dimensional crimps having the number of crimps of 15 to 80 crimp/25 mm and a crimp percentage of 25 to 90%. The fibers are produced by disproportionally cool-solidifying in fiber-forming procedure or by forming in an eccentric core-in-sheath type on side-by-side type composite fiber structure.