基于有限差分法的注塑腔体温度场建模研究

Research on Modeling of Temperature Field for Injection Molding Cavity Based on Finite Difference Method

注射机腔体的温度是保证塑料制品加工质量的重要参数之一。为了得到注塑腔体的温度场分布,本研究基于有限差分法建立了模具腔体的温度分布模型,利用matlab的pdetool工具箱进行温度分布的数值仿真。仿真结果表明:在模具冷却的过程中,热量从模具腔体内侧向模具腔体外侧进行传递。在0~6 s时,模具腔体外侧温度的上升速度增加,此后上升速度逐步减小,最终趋近于熔体的温度。对于不同熔体温度的塑料,熔体的温度越高,同时间的模具外侧温度越高。不同塑料丙烯腈-丁二烯-苯乙烯共聚物(ABS)、聚氯乙烯(PVC)、聚碳酸酯(PC)和聚苯乙烯(PS)的冷却时间与模具性能相关,在同一模具下基本保持一致,分别为28、26.7、27.6和28.4 s。

The temperature of the mold cavity for the injection molding machine is one of the most important parameters to ensure the processing quality of plastic products.In order to obtain the temperature distribution of the injection cavity,the temperature model of the mold cavity based on the finite difference method was established and the pdetool toolbox in matlab software was used to simulate temperature distribution.The simulation results show that during the cooling process of the mold,heat is transferred from the inside of the mold cavity to the outside.At 0~6 s,the temperature rising speed of the outside of the mold cavity increases,and thereafter the speed of rising gradually decreases,finally approaching the temperature of the melt.For plastics with different melt temperatures,the higher the melt temperature,the higher the outside temperature of the mold at the same time.The cooling time of different types of plastic ABS,PVC,PC and PS is related to the characteristics of the mold,which is basically the same under the same mold,respectively 28,26.7,27.6 and28.4 s.