Sink marks appear when thermal shrinkage of plastics material is not compensated. A sink mark usually appear at rib, boss position, or thickness of product is changed. This post I will explain about cause and sink mark troubleshooting. I. Sink mark causes. + Thickness of product is not equal, samples usually have sink marks at transfer […]
injection molding troubleshooting
injection molding troubleshooting flash defect
Injection molding troubleshooting flash defect usually appears near parting line, gas vent, slide core, or ejector pin. Burr looks like a develop film like a plastic edge. I. Causes of flash injection molding. + Material effect. For example, GF resin always have flash. It is difficult to improve flash. + Mold has gap between the […]
injection molding short shot troubleshooting
In injection molding short shot defect cause by molten plastic does not fill the cavity, product marking is incomplete. I. Cause of short shot. + Molten plastics are stick or cold in runner system. + Mold structure is not good so molten plastics can not fill in the cavity. + In injection molding process, air […]
Weld line in injection molding cause troubleshooting
Weld line in injection molding is line where two or more flow molten plastics knit together. These lines occur usually around holes or obstructions and cause locally weak areas in the molded part. Weld line are formed whenever melt fronts separate and recombine at some downstream location. It is formed when parts have multiple gates, […]