注塑压缩成型工艺参数对塑料透镜体积收缩率的影响

Effect of Injection Compression Molding Parameters on Volume Shrinkage of Plastic Lens

利用自主设计加工的透镜模具,选取综合性能较好的聚甲基丙烯酸甲酯（PMMA）为实验原料,通过Moldflow数值模拟和实验验证相结合,研究了塑料透镜注塑压缩成型过程的工艺参数对体积收缩率的影响规律。模拟结果表明：熔体温度变化是造成体积收缩的主要原因,当温度由205℃升至245℃时,体积收缩率从4.98%增加至6.149%;而随着压缩延迟时间的增加,体积收缩率先从5.671%升高到6.295%,然后又降至4.889%;模具温度升高,体积收缩率增大;体积收缩率随着压缩距离的增加先降低后升高,在压缩距离为1.6mm时最小;此外,注射时间在1.2s时的体积收缩率最小;对透镜进行注塑生产,透镜的实际测量结果与模拟分析结果基本吻合。

Using self-designed lens mold, and PMMA（with better overall performance） served as experimental material, the influence of process parameters on volume shrinkage of plastic lens during injection compression molding was studied through the combination of Moldflow numerical simulation and experimental verification. The simulation results show that the change of melt temperature is the main reason for the volume shrinkage. When the temperature changes from 205℃ to 245℃, the volume shrinkage increases from 4.98% to 6.149%. The delay time increases from 5.671% to 6.295% first, and then decreases to 4.889%. The volume shrinkage increases with the rise of mold temperature. As the compression distance increases, the volume shrinkage decreases first and then increases, which reaches the minimum value when the compression distance is 1.6 mm. It also acheives the minimum value when the injection time gets to 1.2 s. The actual measured results of lens which are produced by injection compression molding are in good agreement with the simulation results.