Analysis of different compression-molding techniques regarding the quality of optical lenses

The manufacturing of optical components by injection molding and injection-compression molding is a serious challenge for tool and machine technology as well as for process control. To evaluate the quality of optical parts, the accuracy of the molded geometry as well as the resulting optical performance have been analyzed. At present a geometrical molding accuracy in the lower micron range has been achieved for the production of thick-walled lenses. Overall injection-compression molded lenses showed a better optical performance than injection-molded lenses. Due to these preliminary investigations, different injection-compression-molding technologies are to be examined. Thus, a mold has been developed, which enables the comparison of different injection-compression technologies. The compression step is realized, on the one hand, by the mold motion of the injection molding machine and, on the other hand, by integrated hydraulic pistons. With this mold design, the compression technique using integrated hydra...