Date：2023.06.24

Views：323

In the plastic products, especially the raw materials are ABS, PP, PC, often see the surface of the product will have a shiny stress mark, thimble stress mark, inseam stress mark, meat thickness difference stress mark. Increase or decrease of mold temperature (increase can improve filling and reduce holding pressure; Lower is to let the bite surface shine, the surface and the stress mark close, in general, reduce the mold temperature is the most choice)

These visible bright and white marks are the result of internal stress, which is nothing more than orientation stress and cooling shrinkage stress. The irregular stress marks near the gate are caused by typical orientation stress, while the difference in flesh thickness is a joint result of orientation and shrinkage stress, and the factors that cause stress marks on the ejector pin and diagonal pin are more common

In general, as the holding pressure and time increase, the first ones are the thickness difference stress marks, the inclined pin stress marks, then the thickness difference stress marks, and finally the irregular stress marks near the gate (which will turn white and shiny when viewed on the side). Of course, this also depends on the specific structure of the product and the pouring position

Reducing the holding pressure and holding time is the most important, and understanding this, starting from here, modifying product design and mold design is more effective than adjusting molding

The overall thickness of the meat is too thin or the thickness of the flowing end meat is too thick, resulting in excessive filling pressure and holding pressure. It is necessary to add glue or steal meat from the flowing end. That is to say, when the pressure is reduced, it is necessary to check if the shrinkage area can be improved by stealing meat. If not, it is necessary to add glue on a large surface