MANUFACTURING PROCESS OF POLYESTER-FIBER

摘要

The method comprises; spinning polyethylene terephthalate of limit iscosity above 0.85 with the speed of 3,000-3,600 m/min.; using spinneret orifice with the ratio of length against diameter 2-4; cooling with cooling air of temp. between 25 deg.C and glass transition temp. 85 deg.C, preferrably 45-60 deg.C; two-stage drawing with the draw ratio of 1st stage 1.2-1.5 and total draw ratio 1.4-1.8 at the temp. of between glass transition temp. and crystallization temp., preferrably 90-130 deg.C; heat-treating and finally two-stage relax-treating at the temp. of below 200 deg.C so that the total relax rate be 3-6 %, thus making single fiber fineness of resulting drawn multifilament be 2.5-5 den.