中国塑料 ›› 2019, Vol. 33 ›› Issue (8): 49-55.DOI: 10.19491/j.issn.1001-9278.2019.08.009

• 加工与应用 • 上一篇    下一篇

基于Moldflow的UNCRIMS材料收缩率优化分析

谭安平,骆静   

  1. 成都理工大学工程技术学院
  • 收稿日期:2019-02-18 修回日期:2019-02-27 出版日期:2019-08-26 发布日期:2019-08-26

Analysis of Shrinkage Optimization of UNCRIMS Materials Based on Moldflow

  • Received:2019-02-18 Revised:2019-02-27 Online:2019-08-26 Published:2019-08-26

摘要: 在塑料成型模流分析Moldflow软件里,未修正模具残余应力(UNCRIMS)材料无法进行收缩模拟。以采用UNCRIMS材料的19寸液晶显示器前框为例,模具厂商按照设计经验采用0.5 %的收缩率对制件开模,试模时发现产品表面缩水严重。修改保压参数后缩水得以解决,但制件尺寸过大,不满足装配要求,最终模具报废。为了保证重新开模一次性成功,采用Moldflow软件拟定4种保压方案,并找到了UNCRIMS材料收缩率的计算方法;将分析方案进行综合对比,找出了开模失败的原因并拟定第5种方案,得到了制件的最佳收缩率,计算机辅助工程(CAE)模拟成功,重新开模制件合格。

Abstract: The Moldflow software usually cannot be used to simulate the shrinkage of the UNCRIMS (uncorrected residual stress) materials. In this work, we took the 19-inch LCD front frame made of UNCRIMS as an example for case study. In general, 0.5 % of shrinkage rate was adopted for design of the injection mold in accordance to the normal design experience. However, the serious surface shrinkage of the product was observed during the molding test. The shrinkage of injection-molded part can be solved by modifying holding parameters. When the size of parts is too large to meet the assembly requirements, and the mold will be invalidated. In order to ensure a success for redevelopment of mold, four pressure-holding programs were taken by the Moldflow software to find a method for calculating the shrinkage rate of UNCRIMS materials. By comparing the analysis of these programs comprehensively, the reasons for the failure of development of mold were found. In this case, a new program was taken, and the optimum shrinkage rate of the part was obtained. The CAE simulation was successful, and the injection-molded parts obtained from the redeveloped mold were found to be qualified.