三叶形喷丝孔干法纺丝挤出膨胀过程的模拟

Simulation of Die Swell Process in Dry Spinning with Trilobal Spinneret Hole

建立三叶形喷丝孔的三维挤出膨胀模型,对聚酰胺酸(PAA)/二甲基乙酰胺(DMAC)体系纺丝液的挤出膨胀过程做了模拟分析。研究结果表明,纺丝液从三叶形口模挤出后呈非均匀膨胀,单叶的长轴和短轴膨胀比不同;提高牵伸比后丝条明显细化,但截面异形度变化不大;改善喷丝孔壁面条件可以使纺丝液挤出时的速度趋于平均并能有效减小膨胀比,挤出物的截面形状也更加接近喷丝孔。

A three dimensional die swell model based on a trilobal spinneret hole was established to simulate the die swell process of polyamic acid（PAA）/N,N-dimethylacetamide（DMAC）solution system.The results show that the spinning solution is not well-distributed die swell after extrusion,and the die swell ratio of major axis and minor axis is unequal.The increased draw ratio results in the thinner filament,but the profile degree of cross section is nearly constant.The improved wall condition of spinneret hole is helpful for the average velocity distribution of spinning solution in the spinneret outlet,decreasing the die swell ratio,and therefore the cross section shape is more close to the hole.