The main reasons and solutions for dark color and poor gloss are as follows.
1. Poor finish of the injection mold, rust on the surface of the cavity, etc., which may be due to poor mold exhaust.
2. 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.
3. The gating system of the injection mold is defective. The cold slug well should be enlarged, the runner, polished main runner, runner 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 must 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. Prevent cold material from entering the part, use self-locking spring or lower nozzle temperature when 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 enterprise. The impact of increasing the production efficiency of enterprises.