Patent ID: 8574474

Claim:
A method of preparing a para-aramid fiber comprising: preparing an aromatic polyamide by polymerizing aromatic diamine with aromatic diacid halide; preparing a spinning dope by dissolving the aromatic polyamide in a solvent; extruding the spinning dope through a spinneret; and sequentially passing the spinning dope through an air gap, a coagulation bath filled with a coagulation solution, and a coagulation tube having a jet opening to obtain a filament, wherein the coagulation tube is connected with a bottom of the coagulation bath, wherein a distance from the upper surface of the coagulation solution contained in the coagulation bath to the jet opening of the coagulation tube is within a range between 10 and 35 mm, and wherein a distance from the bottom of the coagulation bath to the jet opening is within a range between 5 and 20 mm.