THE DRY SPINNING OF POLYACRYLONITRILE SOLUTION

Abstract

The dry spinning condition to obtain continuous filaments of polyacrylonitrile from dimethylformaide solution was investigated as to residual solvent, yellowness (YI) and longitudinal dispersion of denier of undrawn filaments.In this study, length and diameter of the spinning tower were fixed. Results obtained are;1) The higher the temperature of hot air and spinning tower, the smaller the residual solvent content; and the increase of hot air intake results in the decrease of the residual solvent content of the undrawn filaments.2) The spinning solution with larger yellowness (YI) results in the undrawn filaments with larger Yl obtained under the same spinning condition.3) The larger the volume of hot air, the higher the concentration of the spinning solution and the smaller the spinning draft, the smaller is the longitudinal dispersion of denier.Optimum range for temperature and concentration of the spinning solution, and temperature of hot air also results in the smaller dispersion of denier.4) The dispersion of denier is not so much influenced by the viscosity of the spinning solution.5) The larger initial drying rate of dimethylformamide from the extruded filaments, which is thought to be proportional to the constant drying rate, makes the longitudinal dispersion of denier smaller.