This article discusses basic consideration for designing two-shot injection molds, which is referred to also as dual-shot, dual-injection, double-shot, double-injection, multi-shot, 2k molding, and overmolding Before tool design, one should check machine injection unit Injection unit sometimes constrain the tooling type. Material shrinkages for each material should be considered. Shrinkage may cause warpage and flash if those are not made up properly in tooling phase. If there is big different in melt temperature between materials, toolheat balancing should be .studied Tooling should consider gate location, access, allowable gate vestige. Draft angle in 2K molding is very critical factor which deciding wheremolded part stuck and rotating. In 1st shot molding, molded part should be stuck on rotating core and 2nd shot molding, molded part should remain on the side of ejecting system employed. If part design imposing creating shut-off surface with molded part after rotating,Draft angle on shut-off surface should be…
What is flash in two shot injection molding? Description 2nd material penetrating between 1st material and its cavity. It is observed frequently where 1st material shrinkage is big and cooling time for 1 material is too long. It is mainly due to too fast shrinking of 1st material. How to trouble shoot the flash? 1.Optimizing holding pressure & Cooling time to get min shrinking of 1st material till before 2nd shot molding. 2.Select less shrinkage rate material for 1st shot. 3.Changing design as preventive action. We’ve spent the past 15 years accumulating rich practical experience in solving the flash of two-shot injection molding. HS Mold has the design, engineering, and in-house tooling capabilities you need to streamline your project 2k injection molding project from conception to production.