How to avoid shrinkage of plastic two-color molds

For the processing process of plastic two-color molds, one of the most troublesome things for people who are not very experienced is the shrinkage phenomenon that occurs during the processing of plastic two-color mold products. After the plastic product is ejected by injection molding, pits will appear on the surface of the product, especially where the material thickness is uneven, which is what we often call product shrinkage. So how to avoid the shrinkage of plastic two-color mold products? Next, the engineers of Hang Seng Digital will introduce how to avoid the shrinkage of plastic products?

Ways to avoid shrinkage of plastic two-color molds:

1. Start with plastic molds. For example, the position of the glue port can be improved or the runner can be enlarged to allow more glue to flow into the cavity. Change the glue port so that the glue inlet is closer to the thicker part of the plastic, so that the pressure holding effect at the thicker glue position is better.

Second, start to improve shrinkage from the injection molding process of plastic two-color molds. Such as lengthening the holding time, adjusting the temperature of the plastic mold, adjusting the injection pressure and time, and other injection parameters to improve the shrinkage.

3. Temporary improvement measures for the injection molding process. After the plastic product is ejected, it is immediately cooled in cold water to speed up the cooling of the injection product, which can alleviate the shrinkage of the injection product to a certain extent.

4. Start with the product and change the product. For example, when reducing plastic, the shrinkage is mainly due to uneven product thickness, which results in different cooling times of the product, while the thin material level that cools faster will pull the plastic at the thick material level. Then it will cause insufficient rubber at the thick material level and form pits. Therefore, we can alleviate the shrinkage problem of plastic two-color mold products by reducing the material thickness of the thick material level.

The above is about how to avoid shrinkage of plastic two-color molds. I hope it will be helpful to everyone. In the plastic two-color mold injection process, if you want to make a good product, you must analyze the defects of the injection molded part during the processing. The real reason is not easy to find out. It requires a combination of process, mold, and structure.