When solving the shrinkage hole problem, the mold cavity temperature is too low, which will increase the degree of shrinkage. Therefore, the mold is preferably cooled by machine water. Do not use frozen water. If necessary, increase the mold temperature, for example, when molding PC material. When the temperature rises to 100 degrees, the improvement effect of the shrinkage hole will be better. However, if it is to solve the problem of shrinkage, the mold temperature can not be raised, but it needs to be reduced.
If the surface of the thick-walled part still has a sink mark, or if a plastic part such as a partial wall is encountered, the introduction of gas-assisted injection molding will be solved.
Gas-assisted injection molding is a novel plastic molding technology that introduces high-pressure gas into the thick-walled part of the part, creates a hollow section inside the injection molded part, completes the filling process, achieves gas holding pressure, and eliminates product shrinkage. The traditional injection molding process cannot combine the thick wall and the thin wall together, and the residual stress of the workpiece is large, it is easy to warp and deform, and there is a shrinkage on the surface.
The newly developed gas-assisted technology successfully produced thick-walled and partial-wall products by hollowing out the thick-walled interior, and the product has excellent surface appearance properties, low internal stress, light weight and high strength.