为了研究T型模头熔体出口的流率均匀性,利用计算流体动力学软件Polyflow对一种T型模头内的熔体流动和模具变形进行了耦合数值模拟.结果表明：模具流道表面沿模具厚度方向的变形在挤出方向和模具宽度方向均为非线性变化,造成熔体出口流率均匀性与不考虑模具变形的理论设计结果相差较大;随着挤出量增加,狭缝沿模具厚度方向的变形增大,熔体出口流率均匀性降低;随着模具厚度增加,狭缝沿模具厚度方向的变形减小,熔体出口流率均匀性提高.

In order to investigate the flux uniformity of melt at the outlet of T die,the melt flow and die deformation in a T die are analyzed by a coupling numerical simulation with CFD software Polyflow.The results show that the deformation of the flow channel surface along mold thickness nonlinearly varies in the extrusion direction and the die width direction,which results in great discrepancy between the simulated melt flux uniformity at the outlet and the theoretical one without considering die deformation.Moreover,it is pointed out that,with the increase of extrusion output,the slit deformation along the mold thickness increases and the melt flux uniformity at the oulet decreases,and that opposite results can be obtained when the die thickness increases.