【摘要】 以实测高密度聚乙烯(HDPE)的性能参数为基础,提出了以挤出口模壁面附近的剪切速率、壁面附近的熔体流动速度与管中心熔体流动速度之比值来描述速度变化、用压力梯度描述压力变化的观点,采用Ansys、Matlab软件对芯棒式管材机头中挤出HDPE薄壁管的成型过程进行了模拟,并系统地描述、分析了成型段的长度及入口压力、入口速度发生变化时对成型段上的速度分布和压力分布的影响,得到了成型段长厚比与入口压力的优化值。更多还原

【Abstract】 By taking the actual high density polyethylene(HDPE) natural parameter as the foundation, the methods of describing the speed change with the shear rate nearby the mold wall surface and the ratio of speed nearby the wall surface to the central speed and describing the pressure variation with the pressure gradient are put forward. With ANSYS, MATLAB to analyse the extrusion process of thin-wall tube in mandrel tube extrude mold, and making a full description of the corresponding influence of the velocity distribution and the pressure distribution in the constant outline section when the inlet pressure, inlet velocity as well as the length of the constant outline section change, the optimization values about inlet pressure and the ratio of the length of the constant outline section to the thickness of the tube were got.更多还原