YARN CONSISTING OF AROMATIC POLYAMIDE FIBER

摘要

PROBLEM TO BE SOLVED: To obtain an aromatic polyamide fiber having a specific fiber structure containing a surfactant, capable of dyeing into a deep shade, crystallized by an ordinary treating process and stabilized against repeated washing. SOLUTION: An amorphous aromatic polyamide fiber filament wet-spun by using meta-phenylene isophthalamide polymer is immersed into a treating bath containing an anionic surfactant while the filament is swollen with water to absorb about 5-15 wt.% of the surfactant. The resultant amorphous fiber is heat-treated, e.g. in an aqueous solution kept at <=130 deg.C under pressure to provide an aromatic polyamide fiber capable of readily crystallizing and stabilized against shrinkage due to repeated washing. Preferably, the amorphous fiber can be dyed into deep shade and simultaneously crystallized by putting the fiber into a dyeing bath containing a basic dye and dyeing the fiber under pressure.