Melt spinning of ultra-oriented crystalline filaments

摘要

Ultra-oriented, crystalline synthetic filaments with high tenacity are produced by extrusion of a fiber-forming synthetic polymer melt into a liquid isothermal bath maintained at a temperature of at least 30° C. above the glass transition temperature of the polymer, withdrawing the filaments from the bath and then winding up the filaments. Polyethylene terephthalate filaments so produced at 3000-5000 m/min exhibit a crystalline structure and possess birefringence of 0.20-0.22, tenacity of 7-9 g/d, break elongation of 14-30% and boil-off shrinkage of 5-10%.