微孔塑料挤出发泡数值模拟

Numerical Simulation of Microcellular Plastics Extrusion Foaming

微孔塑料连续挤出发泡中的熔体压力和压力降速率是比较重要的参数,一般而言越大的压力降和压力降速率越有利于微孔连续挤出发泡成型。文章通过对毛细管口模的模拟,总结了几种提高熔体压力和压力降速率的方法,分析了熔体温度和熔体中CO_2的溶解度对熔体流动的影响。研究发现,可以通过缩小毛细管直径、增加毛细管长度、降低熔体温度、降低熔体中的CO_2溶解含量、增加质量流率来提高熔体压力;可以通过缩小口模直径,降低熔体温度、降低CO_2溶解含量、增加质量流率来增加熔体的压力降速率。

Melt pressure and pressure drop rate are important parameters in microcellular plastics continuous extrusion foaming. Generally,greater pressure drop and pressure drop rate are conducive to microcellular plastics continuous extrusion foaming. In this paper,capillary die was simulated,some ways to increase melt pressure and pressure drop rate were summarized,the influence of melt temperature and solubility of CO2 in melt to melt flow was analyzed. The results show that reduced capillary diameter,increased capillary length,lower melt temperature,lower solubility of CO2 in melt can increase melt pressure; reduced capillary diameter,lower melt temperature and lower solubility of CO2 in melt can increase pressure drop rate.