Why does dark luster appear in injection mold products
Injection mold is a tool for producing plastic products; it is also a tool for giving plastic products a complete structure and precise dimensions. Injection molds often encounter dark color and poor gloss during the processing and manufacturing process, so what is the reason for the dark color and poor gloss? And how to solve it?
In the process of normal injection mold production and processing, the gloss of the mold surface is mainly determined by the type of plastic, the colorant and the finish of the mold surface. “The main reasons and solutions for dark color and poor gloss are as follows.
1 The injection mold has poor finish, rust on the surface of the cavity, and poor mold exhaust.
2Too 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.
3 The gating system of the injection mold is defective. The cold slug well should be enlarged, the runner, polished main runner, subchannel and gate should be enlarged.
4 The material temperature and mold temperature are low, and local heating of the gate can be used if necessary.
5 Plastics should be fully plasticized, but to prevent degradation of materials, be stable when heated, and adequately cooled, especially thick-walled ones.
6 The clamping force must be sufficient during the manufacturing process of the injection mold.
7 The injection mold 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.
8 To prevent cold material from entering the part, use a self-locking spring or lower the nozzle temperature if necessary.
Doing the above 8 points can well avoid the phenomenon of dark color and poor gloss in the injection mold. Even if this phenomenon occurs during the production process, remedial measures can be taken to minimize the production progress of the company and increase the production efficiency of enterprises.