以方型口模为例,建立描述其成型过程的理论模型,运用Polyflow软件,对方型材传统口模和气辅口模挤出成型过程分别进行三维等温数值模拟分析。通过模拟分析,得出速度场、温度场分布图。结果表明:气辅挤出过程中聚合物熔体各点的速度和压力趋于一致,能有效减小挤出过程中的挤出胀大,有利于控制产品的形状和尺寸,提高产品精度。 Taking square die as an example, a theoretical model describing its forming process was established. By using Polyflow software, three-dimensional isothermal numerical simulation was conducted on the traditional die and gas-assisted die extrusion process. Through the simulation analysis, get the velocity field, the temperature field distribution map. The results show that the velocity and pressure at each point of the polymer melt tend to be the same during the gas-assisted extrusion process, which can effectively reduce the extrusion bulge during extrusion, which is beneficial to control the shape and size of the product and improve the product accuracy.