PURPOSE: To provide a process for producing a PVA fiber having excellent strength and elastic modulus by drawing an undrawn polyvinyl alcohol(PVA) yarn at a high speed.
CONSTITUTION: A spinning dope containing 2-35wt.% of PVA having an average polymerization degree of 21,500 is spun by a solution spinning method and the obtained undrawn yarn is drawn by a multi-stage heat drawing of two or more stages using a hot-air heater. The hot drawing is carried out by using a hot-air heater having an oven length of ≤10m and keeping the draw ratio from the spinning to the 1st-stage hot drawing to 20-80% of the total, draw ratio, the fiber outlet-side temperature of the 1st hot air heater to 100-250°C, the fiber outlet-side temperature of the 2nd hot air heater to 150-350°C, the total draw ratio to ≥15 and the final take-up speed to 100-600m/min.
NAGATA NAOHIKO
MURAKAMI SHIRO
NAGATOMI KAZUYA
ICHINOSE NAOJI
TAKAGI SHINYA
