• How to fix defects on double injection molding

    This article mainly discusses some of the molding defects that can occur in a part during the process of double injection molding, and ways to fix and avoid them.    Flash Description –2nd material penetrating between 1st material and its’ It observed frequently where 1st material shrinkage is big and cooling time for 1material is too long. It is mainly due to too fast shrinking of 1stmaterial. Optimizing holding pressure & Cooling time to get min shrinking of 1stmaterial till before 2nd shot Select less shrinkage ratematerial for 1st Changing design as preventive Rainbow Description – Because of too high melt temperature or shear, 1st molded material remelt and flow with 2nd § Solution   Lower 2nd material melt temperature or minimize Use low melt resin or low viscosity material as 2nd Changing the sequence of material.( Clear – 1st shot, Opaque- 2nd shot) Washout Description – Because of too high melt temperature or shear,…

    Mold making, Uncategorized January 11, 2020