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 DEG 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%.