薄壁塑件注射压缩成型热残余应力仿真研究

使用Moldflow MPI/Injection-compression模块对薄壁塑件顺序注射压缩成型工艺进行了仿真,采用单因素试验研究了熔体温度、模具温度、延迟时间、压缩距离、压缩速度、压缩压力和保压压力对脱模后热残余应力的影响。仿真结果表明,顺序注射压缩成型薄壁制件热残余应力分布规律与常规注射成型相似,但是前者热残余应力较小且沿流动方向更为均匀;热残余应力随熔体温度、模具温度、压缩距离、压缩速度的增加而减小,随延迟时间和保压压力的增加而增大;压缩压力大于熔体流动阻力后,继续增大压缩力对热残余应力无影响。

Study on Thermal Residual Stress of Injection Compression Molded Thin-walled Plastic Part by Simulation

Sequential injection compression molding of a thin-walled plastic part was simulated in commercial software MPI/injection-compression.The effects of various processing parameters,i.e.melt temperature,mold temperature,press waiting time,press distance,press speed,press force and packing pressure on part thermal residual stress were investigated through single factor experiment design.The results showed that though thermal residual stress distribution of sequential injection compression molded part shares similarities with that of traditional injection molded ones,the former shows smaller thermal residual stress,and that thermal residual stress increased with increasing melt temperature,mold temperature,press distance and press speed,while decreased with increasing press waiting time and packing pressure.The effect of press force,however,had negligible effect on thermal residual stress once it became larger than the value high enough to push the melt back to the runner against the applied packing pressure.