FILAMENT-LIKE FIBERS AND BUNDLES THEREOF, AND NOVEL PROCESS AND APPARATUS FOR PRODUCTION THEREOF

摘要

A novel filament composed of at least one thermoplastic synthetic polymer, said filament being characterized by having (1) an irregular variation in the size of its cross section along its longitudinal direction, and (2) a coefficient of intrefilament cross-sectional area variation ¢CV9F)! of 0.05 to 1.0; and a novel bundle of said filament. The bundle of filament-like fibers can be produced by extruding a melt of a thermoplastic synthetic polymer through a spinneret having numerous small openings, which comrises extruding said melt from said spinneret, said spinneret having such a structure that discontinuous elevations are provided between adjacent small operings on the extruding side of the spinneret, and the melt extruded from one opening can move to and from the melt extruded from another opening adjacent thereto or vice versa through a depression existing between said elevation; and taking up the extrudates from the small openings while cooling them by supplying a cooling fluid to the extrusion surface of said spinneret or its neighborhood, whereby said extrudates are converted into numerous separated fine fibrous streams and solidified.