Causes and solutions of surface color and gloss defects of injection mold molded parts

Injection mold is a tool for producing plastic products; it is also a tool for giving plastic products a complete structure and precise dimensions.The injection mold consists of two parts: a movable mold and a fixed mold. Mold injection molding is a processing method used in mass production of some complex-shaped parts.The plastic raw materials are injected into the injection mold cavity through the injection molding machine, and the molded injection parts are obtained after cooling and solidification.

Under normal circumstances, the surface of the plastic products obtained by this injection molding method has relatively good gloss and beautiful colors, but there are many in the actual injection molding production process.Injection Mold FactoryThe products produced have relatively large defects in color and gloss. In addition to the rigid factors of plastic raw materials, colorants and mold surface finish, what other reasons can cause this situation?Today, the Dongguan Injection Mold Factory PTJ will solve this mystery and how to deal with it.

  • (1) The mold finish is poor, there are rust marks on the surface of the cavity, and the mold is poorly vented.
  • (2) The gating system of the mold is defective, the cold slug well should be enlarged, the runner, polished main runner, runner and gate should be enlarged.
  • (3) The material temperature and mold temperature are low, and local heating of the gate can be used if necessary.
  • (4) The processing pressure is too low, the speed is too slow, the injection time is insufficient, and the back pressure is insufficient, resulting in poor compactness and dark surface.
  • (5) Plastics must be fully plasticized, but the degradation of the materials must be prevented, the heating must be stable, and the cooling must be adequate, especially for thick-walled ones.
  • (6) Prevent cold material from entering the part, use self-locking spring or lower nozzle temperature when necessary.
  • (7) Too much recycled materials are used, plastics or colorants are of poor quality, water vapor or other impurities are mixed, and lubricants used are of poor quality.
  • (8) The clamping force should be sufficient.

It can be seen that to manufacture a high-quality plastic product requires a lot of work, not only good plastic raw materials, but also sophisticated processing and production equipment, high-quality and high-precision injection molds, and skilled and experienced operators. Enough patience and care in the entire production process can finally be completed.

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