基于正交试验法的三层吹膜机头优化分析

Optimization Analysis of Three-layer Blown Film Dies Based on Orthogonal Experiment

为产出厚度均匀,无熔接痕,无晶点的薄膜,针对生产LLDPE/LDPE复合薄膜的三层螺旋芯棒式吹膜机头的结构,运用FLUENT仿真,分析结构参数对出口流动均匀性、熔体滞留区域以及机头内部最大压力值的影响。并采用正交试验法,筛选出较好的参数。结果表明,压缩段宽度压缩比对于出口流动均匀性影响最大,外层初始间隙对熔体滞留区域影响最大,中层初始间隙和中层螺旋消退角对于机头内部的最大压力影响最大。为三层螺旋芯棒式吹膜机头的结构优化提供了一种新方法。

In order to obtain the film with uniform layer thickness,no weld lines and no crystal points,aiming at producing composite film of LLDPE/LDPE by the structure of three-layer spiral mandrel dies,the effects of structural parameters on the flow uniformity of the outlet,the stagnation zone of the melts and the maximum pressure in the die have been analyzed by applying FLUENT simulation.And better parameters are selected using orthogonal design.The results indicate：the compression ratio of compression width matters the most to flow uniformity,outer initial clearance matters the most to stagnation zones,middle intial clearance and spiral decreasing angle matters the most to the maximum pressure drop in the die.This will provide a new method for the structure optimization of three-layer spiral mandrel dies.