The main reasons for the shrinkage of plastic hanger molds

        Poor shrinkage of the plastic hanger hook occurs in the surface of the molded part, which generally occurs in the thick part of the meat with a large volume shrinkage. In the process of cooling the molded product, the volume shrinks, and a pulling force that shrinks toward the center portion is thereby generated.

      At this time, affected by the balance between the rigidity of the surface cold material layer and the shrinkage force of the resin, when the cold material layer of the plastic hook is weak, a pulling force is generated to the center of the molded part, which appears as a concave shape on the surface of the product. When the cold material layer is strong, vacuum bubbles will be generated in the center of the molded part. In the thicker meat area, the balance between the rigidity of the cold material surface and the shrinkage force of the resin is closely related to the cooling rate of the surface of the molded part, and vacuum bubbles are formed when the cooling rate is faster. Conversely, shrinkage is formed when slower. In addition, as the cooling rate becomes slower, the difference in volume shrinkage becomes smaller, and the shrinkage condition becomes smaller.

                                                                                                                                              Information comes from China Plastic Hanger Network