Sometimes, the surface of the products produced by the injection molding factoryinjection molding factory is dim and poor gloss. The causes of such defects can be divided into the following three types: mold failure, improper control of molding conditions, and improper use of molding materials.

First of all：Mold failure

If the mold surface has scars, corrosion, micropores and other surface defects, it will be copied to the surface of plastic parts, resulting in poor gloss. If there is oil and moisture on the surface of the cavity, the surface of the plastic part will be darkened. Therefore, the cavity of the mold should have a good finish, and it is better to adopt polishing treatment or chromium plating on the surface. The surface of the cavity must be kept clean， oil and water stains should be removed in time.

Mold temperature also has a great influence on the surface quality of plastic parts，If the mold temperature is too low, the raw material will solidify immediately after contacting with the mold cavity, which will reduce the reproducibility of the mold cavity surface， In order to increase the gloss, the mold temperature can be appropriately increased

Second：Improper control of the mold forming

If the injection speed is too fast or too slow, the injection pressure is too low, the barrel temperature is too low, and the feeding is insufficient, the surface gloss of plastic parts will be caused. Therefore, it should be adjusted according to the specific situation.

Third：The raw material does not meet the requirements of use will also lead to poor surface gloss of plastic parts

For example：If there is too much moisture or other volatile substances in the raw materials, the volatile components will condense in the mold cavity wall, so the raw materials should be pre dried.

The degradation and discoloration of raw materials lead to poor gloss. So Raw materials and colorants with high temperature resistance should be selected.

The poor fluidity of raw materials makes the surface of plastic parts not dense, which leads to poor gloss. Therefore, we need to replace the resin with good flow performance or add proper amount of lubricant and increase the processing temperature.