基于有限元数值模拟技术的热固性塑料模压制品收缩率研究

Study on Shrinkage Ratio of Molded Thermosetting Plastic Products by Finite Element Numerical Simulation Technology

以有限元数值模拟技术作为辅助手段,采用单独变量实验法对热固性塑料模压成型制品收缩率的影响因素、结构组成和变化规律进行了研究。结果表明:对制品收缩率影响较大的因素是模压成型过程中的成型压力、成型温度、保压时间等。制品的收缩率由模具弹性变形、模具热变形、制品弹性恢复、制品冷却收缩和"残余收缩"共同构成,其中权重最大的是"残余收缩"。模具弹性变形、模具热变形、制品弹性恢复、制品冷却收缩分别与成型压力和成型温度成线性相关关系,而当成型压力、成型温度、保压时间处于某一范围内时,"残余收缩"呈现出一定的稳定性。

The influencing factors, structure composition and variation law for the shrinkage ratio of the compression molding products made from thermosetting plastics were studied by the method of single variable experiment which taking finite element numerical simulation as auxiliary means. The results show that the influencing factors, such as molding pressure, molding temperature and dwell time, make more influence on the shrinkage of products. Shrinkage of product is composed by mould elastic deformation, mould thermal deformation, product elastic recovery, product cooling shrinkage and ＂residual shrinkage＂, among them, ＂residual shrinkage＂ shows more weight. Mould elastic deformation, mould thermal deformation, product elastic recovery and product cooling shrinkage show linear correlation relationship with molding pressure and molding temperature, respectively. When molding pressure, molding temperature and dwell time are in a certain range, ＂residual shrinkage＂ has a relative stability.