干湿法PAN纤维截面成形条件的研究

对干湿法纺丝中PAN纤维的截面形状影响因素进行了研究。研究发现,凝固浴浓度和温度是影响纤维截面的主要因素,随着凝固浴浓度的增大和温度的升高,纤维截面逐渐由扁平形变为圆形,纤维截面的异形度逐渐减小;干湿法比湿法纺丝更有利于得到圆形截面的纤维;随着空气层高度的增大,纤维截面的异形度减小,但当空气层高度超过10mm时,纤维截面形状不再变化;在一定条件下,喷丝头拉伸比对纤维的截面形状有一定影响,后拉伸过程和干燥对纤维截而形状基本上没影响。

Study on shape forming conditions of cross section of PAN fiber during dry-jet-wet spinning

The influential factors on cross section shape of PAN fiber were studied during dry-jet-wet spinning.The results showed that the primary influential factors were coagulation bath concentration and temperature.The cross section shape of the fi- ber was transformed from flat shape into circular shape and the profile degree of the cross section was gradually decreased when the coagulation bath concentration and temperature were increased.The dry-jet-wet spinning process was more helpful to the for- mation of circular cross section as compared with wet spinning process.The profile degree of cross section was restrained when the air gap height was increased.The cross section shape remained unchanged when the air gap height was above 10mm.The jet stretch ratio obviously affected on the cross section shapes of PAN fiber under some specific conditions.The post-drawing and dr- ying processes had hardly effect on the cross section shape.