TPU流变性能测试及胶片挤出过程模拟仿真

Rheological Property Test of TPU and the Simulation of Film Extrusion Process

利用高压毛细管流变仪对热塑性聚氨酯弹性体(TPU)熔体的流变性能进行测试分析,建立相应的熔体本构方程。利用polyflow软件对TPU熔体在经过优化的衣架型口模内的流动情况进行模拟分析,以检验所用口模的性能,同时采用广义Navier滑移模型分析不同滑移系数对流动状态的影响。结果表明,Bird-Carreau模型可以准确描述TPU熔体的流动行为。在不同温度下,TPU熔体在模拟所用的衣架型口模中均能实现均匀挤出,并且挤出过程接近壁面无滑移情况。

In this paper, the rheological properties of TPU melt were tested by high pressure capillary rheometer, and the constitutive equation was established. The Polyflow software was used to simulate and analyze the flow of TPU melt in the optimized hanger die to test the performance of the die, and the generalized Navier slip model was used to analyze the influence of different slip coefficients on the flow state. The results show that the Bird-Carreau model could accurately describe the flow behavior of TPU melt. At different temperatures, the TPU melt could be evenly extruded in the existing coat hanger die, and the extrusion process is close to the boundary condition without slip on wall.