Patent ID: 8834755
Filing Date: 2014-09-16
Classification: D01D,D01F,Y02P,Y10T

Abstract:
1. A method of manufacturing wholly aromatic polyamide filament, comprising: dissolving wholly aromatic polyamide polymer in a concentrated sulfuric acid solvent to prepare a spinning liquid dope; spinning the liquid dope through a spinneret to give a spun material; and feeding the spun material through a non-coagulation fluid layer into a coagulant injection tank containing coagulant, characterized in that the method comprises the step of multi-stage injecting of the coagulant with sulfuric acid concentration lowered sequentially stage by stage, to the spun material fed into the injection tank, wherein an aqueous sulfuric acid solution with sulfuric acid concentration of 10 to 20% is injected at the velocity of 1 to 10 m/sec to the spun material at a first stage, followed by a second stage to inject an aqueous sulfuric acid solution with sulfuric acid concentration of 3 to 10% at the velocity of 13 to 20 m/sec and a third stage which directly follows the second stage, wherein in the third stage, water is injected at the velocity of 20 to 25 m/sec to the spun material.