More and more mold makers are involved in manufacturing plastic injection molds for cooling system of automotive. However, the warp issue caused by plastic PA66＋30GF is always a hard task to complete. To handle the project, it requires consolidating force from each team including mold flow/design/machining/QC. And the whole team must own rich experience, otherwise the critical dimensions are difficult to be achieved and mold has been changed again and again. For most companies, core and cavity needs to be replaced at least one time. Dumping away blocks is quite commonly seen.