基于CAE技术的PMMA灯壳注塑成型缺陷分析及模具设计

Defect Analysis and Mold Design of PMMA Lamp Shell Injection Molding Based on CAE Technology

LED灯壳为带有外螺纹的球头深筒形件,其壁厚不均匀,对外观质量和安装使用要求较高,采用PMMA塑料注塑成型。应用CAE技术对模具设计方案进行“冷却+填充+保压+翘曲”分析,根据模拟分析填充、气穴、熔接痕及变形等情况,首次试模采用优化注塑成型工艺参数、烘干原料等措施无法解决因排气不良等引起的波纹、熔接痕及收缩变形等缺陷。因此,结合首次试模情况及模具结构特点,设计了2种规格溢料槽,经CAE技术分析比较后,选择最佳模具设计方案,并对螺纹加工尺寸进行变形补正,提高了再次试模成功率,为企业开发同类产品提供有实践参考价值的注塑成型方案。

LED lamp shell was a ball head deep cylinder with external thread,uneven wall thickness,high appearance quality and installation requirements.PMMA plastic injection molding was adopted.CAE technology was applied to analyze the original mold scheme of cooling,filling,pressure maintaining,warping.According to the simulation and analysis of the filling,cavitation,weld line and deformation,the defects such as ripple,weld line and shrinkage deformation caused by poor exhaust were not solved by the measures such as optimizing the injection molding process parameters and drying the raw materials.According to the first mold test and the structural characteristics of the mold,two kinds of overflow grooves were designed.Through the analysis and comparison of CAE technology,the best mold design scheme was selected.In addition,the deformation correction of thread processing size is carried out.The success rate of the second mold test was improved.The practical reference for enterprises to develop similar products was provided.