扁平腈纶湿法成形过程中的挤出胀大行为的模拟

应用Polyflow软件通过理论模拟的方法,对扁平腈纶(PAN纤维)湿法成形过程中的挤出胀大行为进行模拟,建立了喷丝孔口挤出胀大比与纺丝工艺参数之间的关系,研究了纺丝温度、喷头挤出速度、负拉伸率、凝固浴温度等工艺参数对挤出胀大比的影响规律。结果表明:挤出胀大比随着挤出速度、负拉伸率的增大而增大,随着纺丝温度的增大而减小,而挤出胀大比受凝固浴温度的影响较小;对模拟结果进行了实验验证,在喷丝板为0. 1 mm×0. 04 mm、板厚为1 mm、纺丝温度40℃、凝固浴温度10℃、凝固浴质量分数14%、入口流量2. 21×10^-3mL/s、喷丝头负拉伸率为-43%的条件下,纺丝制得的扁平PAN纤维的扁平度达到6. 4,线密度为11 dtex,且可纺性好,模拟结果具有合理性。

Simulation of extrusion swelling behavior of flat acrylic fiber in wet forming process

The extrusion swelling behavior of flat acrylic fiber(PAN fiber)in wet forming process was theoretically simulated with Polyflow software.The relationship between the spinneret dieswell ratio and spinning process parameters was established.The influence law of spinning temperature,spinneret extrusion rate,negative draw ratio and coagulation bath temperature on the spinneret dieswell ratio was studied.The results showed that the dieswell ratio was increased with the increase of extrusion rate and negative draw ratio and was decreased with the increase of spinning temperature when it was slightly affected by coagulation bath temperature;and the obtained flat PAN fiber exhibited the flatness of 6.4,linear density of 11 dtex and good spinnability when the process conditions were as followed:spinneret 0.1 mm×0.04 mm,spinneret thickness 1 mm,spinning temperature 40℃,coagulation bath temperature 10℃,mass fraction of coagulation bath 14%,inlet flow 2.21×10^-3 mL/s and negative draw ratio of spinneret-43%,which proved that the simulated result was reasonable.