Method for manufacturing polyacetal fiber

A method for producing a polyacetal fiber, wherein:

• the method comprises a discharge step, a take-off step, a drawing step and a winding step, the steps being successively carried out;
• an oxymethylene copolymer is used as a raw material of the polyacetal fiber, the oxymethylene copolymer having an oxymethylene unit and an oxyethylene unit, the content of the oxyethylene unit being 0.5 to 7.0 mol relative to 100 mol of the oxymethylene unit;
• the roller temperature of a drawing unit used in the drawing step is 130 to 155° C.;
• and
• when a value obtained by dividing a rate difference between a rate of discharging the oxymethylene copolymer from a discharge nozzle in the discharge step and a rate of taking off the fiber using a take-off roller in the take-off step by a distance between the discharge nozzle and the take-off roller is referred to as a rate difference per unit distance x (1/sec) and defined as formula (A):
• Rate difference per unit distance(x)=(rate of take-off roller(m/sec)−rate of discharging resin from discharge nozzle(m/sec))/distance(m) (A),
• and the ratio between an area of the discharge nozzle and a cross-sectional area of the polyacetal fiber after the winding step is referred to as an area ratio y (no unit dimension) and defined as formula (B):
• Area ratio(y)=area of discharge nozzle(mm2)/cross-sectional area of polyacetal fiber after winding step(mm2) (B),
• formula (C) below is satisfied:
• y>1600/x (C)
• with the proviso that 1.5<x<15.