醋酸纤维素纤维干法纺丝成形模拟

建立了基于Maxwell粘弹性本构方程的干法纺丝动力学模型,对醋酸纤维素纤维干法纺丝过程进行了模拟,预测了纤维成形过程中丝条的溶剂浓度、温度、速度、张力等沿纺程的变化关系。结果表明:纤维固化成形发生在闪蒸结束后离喷丝口不远处,此后丝条溶剂含量变化很小;丝条温度在闪蒸时略低于热吹风温度,闪蒸结束后迅速上升到热吹风温度;丝条张力主要来源于空气的摩擦阻力和卷绕张力,在纺程下半段以摩擦阻力为主;提高泵供量后溶剂蒸发速率变慢,丝条温度达到热吹风温度所需时间变长,丝条固化点离喷丝头越远;闪蒸速率随纺丝液溶剂含量增高而减小,同时丝条温度升到甬道温度的时间也越长。

Simulation of dry spinning of cellulose acetate fibers

A kinetic model of simulating the dry spinning process of cellulose acetate fiber was built based on Maxwell viscoelastic constitutive equation.The change of the solvent content,temperature,velocity and tension of the filament along with spin line was predicted.The results showed that the filament solidified not far from the spinneret after flash evaporation and the solvent content of the filament changed a little afterwards.The filament temperature was slightly lower than hot air temperature during flash evaporation,but rapidly rose to the hot air temperature as the flash evaporation finished.The filament tension was mainly consisted of air drag and take-up tension and the air drag dominated in the second half section of the spin line.The solvent evaporation rate dropped while increasing pump delivery;at the same time the required time increased for the filament rising to the hot air temperature and the solidification position became farther from the spinneret.The flash evaporation rate decreased while increasing the solvent content spinning solution,and the required time was also prolonged for the filament rising to the hot air temperature.