PVC线槽挤出成型的Polyflow优化与模具设计

Polyflow Optimization and Mould Design of PVC Trunking Extrusion Molding

运用Polyflow软件模拟挤出PVC线槽,通过对比观察黏度、挤出速率、口模长度对挤出成型的影响。结果表明:熔体黏度越大,流体剪切速度增大,挤出膨胀现象会加剧;增大挤出速率,材料在口模中定型的时间越短,其变形越大;口模长度越长,有利于制件形状接近预设口模形状。为获得形状与尺寸准确的制件,采用Polyflow软件模拟逆向挤出过程,逆向得出合理的口模截面形状设计参数,并对口模长度以及定型模设计进行合理优化。产品长度尺寸为20 mm,模具底部设计成19.8 mm,开口设计成25.9 mm,而口模膨胀产品截面厚度为1.5 mm时,对应的模具截面厚度为1.3 mm。

Polyflow software was used to simulate the extrusion of PVC trunking,and the effects of viscosity,extrusion rate and die length on extrusion molding were observed by comparison.The results show that the larger the melt viscosity is,the higher the fluid shear rate is,and the extrusion swell phenomenon will be aggravated.With the increase of the extrusion rate,the shorter the setting time of the material in the die,the greater the deformation.The longer the die length is,the closer the part shape is to the preset die shape.In order to obtain the parts with accurate shape and size,Polyflow software was used to simulate the reverse extrusion process,and the reasonable design parameters of the cross-section shape of the die were obtained reversely,and the length of the die and the design of the setting die were optimized reasonably.The length of the product is 20 mm,the bottom of the die is designed to be 19.8 mm,the opening is designed to be 25.9 mm,and when the section thickness of die expansion product is 1.5 mm,the section thickness of die is 1.3 mm.