1)  Defect Analysis

      Sink marks commonly occur in areas with material accumulation, caused by the inability of the injection molding process to                      

     compensate for thermally-induced plastic shrinkage due to pressure loss.

     (凹痕多数出现在物料聚积的部位，是由于注塑件因失压而未能补偿由热引致的塑料收缩。)

    ① Sink marks occurring near reinforcing ribs.   ② Sink marks appear in areas with             ③ The cylindrical core causes poor temperature                                                  (在加强肋附近出现的凹痕)                                   significant thickness variation.                     control at that location, resulting in sink marks.

                                                                                   (凹痕出现在胶位厚薄变化大的部位)              (圆形模芯令该处的溫度控制不良而产生凹痕)