Chang Han-Jui, Su Zhi-Ming
Key Laboratory of Intelligent Manufacturing Technology, Shantou University, Ministry of Education, Shantou 515063, China.
Materials (Basel). 2020 Mar 5;13(5):1151. doi: 10.3390/ma13051151.
The purpose of this study is to clarify the influence of changes in glass fiber properties on warpage prediction, and to demonstrate the importance of accurate material property data in the numerical simulation of injection molding. In addition, this study proposes an optimization method based on the reverse warping agent model, in which the thermal conductivity of the plastic material is reduced, and the solidified layer on the surface of the mold is reduced and transferred from the molding material to the mold wall. This means that by the end of the cooling phase, the shrinkage of the molten zone within the component will continue, resulting in warpage. Based on the optimal process parameters, the sensitivity of the warpage prediction to the relationship between the two most important material properties, the glass fiber and holding pressure time, was analyzed. The material property model constants used for numerical simulations can sometimes vary significantly due to inherent experimental measurement errors, the resolution of the test device, or the manner in which the curve fit is performed to determine the model constants. This model has been developed to intelligently determine the preferred processing parameters and to gradually correct the details of the molding conditions. Thus, the cavity is separated in the critical warpage region, and a new cavity geometry with a reverse warped profile is placed into the mold base slot. The results show that the hypothetical and reasonable variation of the glass fiber model constant and the holding pressure time relationship may significantly affect the magnitude of the warpage prediction of glass fiber products. The greatest differences were found as a result of the warping orientation of the glass fiber material.
本研究的目的是阐明玻璃纤维性能变化对翘曲预测的影响，并证明准确的材料性能数据在注塑成型数值模拟中的重要性。此外，本研究提出了一种基于反向翘曲剂模型的优化方法，其中降低了塑料材料的热导率，减少了模具表面的固化层，并将其从成型材料转移到模具壁上。这意味着在冷却阶段结束时，部件内熔融区的收缩将继续，从而导致翘曲。基于优化的工艺参数，分析了翘曲预测对两个最重要的材料性能（玻璃纤维和保压时间）之间关系的敏感性。由于固有的实验测量误差、测试设备的分辨率或进行曲线拟合以确定模型常数的方式，用于数值模拟的材料性能模型常数有时会有显著差异。该模型已被开发用于智能确定优选的加工参数，并逐步校正成型条件的细节。因此，在临界翘曲区域对型腔进行分离，并将具有反向翘曲轮廓的新型腔几何形状放入模架槽中。结果表明，玻璃纤维模型常数与保压时间关系的假设性和合理变化可能会显著影响玻璃纤维产品翘曲预测的幅度。由于玻璃纤维材料的翘曲方向，发现了最大的差异。
