聚氨酯反应注射成型充模流动研究

Studies of Ployurethane RIM Mold Filling

聚氨酯原料体系反应注射成型(RIM)制品在汽车构件、商用机器外壳等制造方面得到越来越广泛的应用,同时RIM制品也朝着体积大、注射速度快的方向发展.但目前在模具设计及工艺参数选择中仍采用经验或尝试的方法,耗费大量人力物力.为此,本文对长扁平板模聚氨酯反应注射成型(RIM)充模流动过程进行了实验研究并建立了计算模型.得出的压力计算公式与实验结果进行了对比.结果表明在充模时间t_f远小于凝胶时间t_(km)时充模过程中混合物料的粘度可视为常量,并可据此计算充模压力.

Polyurethane RIM product has found more and more applications in making automobile exterior parts and commercial ma-chine frame. The present trend in RIM is toward larger, more complex part and faster reacting system. But until now. in mold designing and process parameter selecting, the trial and error approach are still employed. This paper deals with studies of RIM mold filling in a plaque mold. A model is developed for pressure rise, extent of reaction and temperature changes during filling. The prediction of the model are shown to be in good agreement with experimental result.