Date：2023.08.17

Views：80

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 apparently shiny, white marks are the result of internal stresses, which are nothing more than orientation stresses and cooling shrinkage stresses. The irregular stress marks near the gate are caused by typical orientation stress, and the difference in meat thickness is the common result of orientation and contraction stress, while the factors of thimble and skew pin stress marks are more.

Under normal circumstances, with the increase of pressure and time, the first is the meat thickness difference stress mark, the thimble skew pin stress mark, and then the meat thickness difference stress mark, and finally the irregular stress mark near the gate (the side will be white hair bright), which of course depends on the specific structure of the product and the pouring position.

Reducing the holding pressure and holding time is the most important, and to understand this, start from here to modify the product design and mold design is more effective than the molding adjustment

The overall meat thickness is too thin or the meat thickness at the flowing end is too thick, resulting in excessive filling pressure and holding pressure, which requires gluing or stealing meat at the flowing end. That is to say, when the pressure is reduced, see whether the shrinkage can be improved by stealing meat, if not, it is necessary to add glue to the large surface