自由曲面光学透镜注射成型误差因素研究

Investigation on error factor of injection molding plastic for freeform optics

自由曲面光学透镜注射成型误差对其光学性能将产生直接影响。注射成型过程中,注射工艺参数组合的优劣,直接影响成型误差的大小。为了获得高精密度的光学元件,就热塑性塑料的注射温度、模具温度、注射压力、保压压力及保压时间等主要工艺参数,对注射成型误差的影响进行综合研究,并且进行了实验验证。研究结果表明:适当提高注射温度与模具温度,同时采用高压注射、高压保压以及快速保压工艺,可显著降低注塑工件的体积收缩率,显著提高面形精密度,其光学表面面形误差小于0.1μm。可为注射工艺设计提供合理的依据。

The error factor of injection molding has a direct effect on the quality of a plastic freeform optics. In the process of injection molding, the combination of injection parameters and the injection process control significantly affects the error of molded plastics. In order to obtain higher precision plastic optical components, this paper focused on some key parameters such as the temperature of mold and injected material, injection pressure, holding pressure and holding time, and analyzed their effect on the quality of injected part. The theoretical research was proved by the experiments. The result indicates that, the shrinkage rate of volume is reduced, and the form and surface accuracy is improved by increasing the temperature of injection and mold, the pressure of injection and holding pressure. Thus, the precision plastic optical components can be obtained with the error of less than 0.1 μm.