The production of injection molding products, all need to use injection molding mold. Under normal circumstances, the surface of plastic products produced by this injection molding method has good gloss and color, but sometimes it is inevitable to have some shortcomings. In addition to the material problems of the plastic itself, colorant and the glossiness of the mold surface, what will the injection molding process have What are the reasons for this?
(1) The surface of the mould is rusty, and the die has poor air exhaust.
(2) If there is a problem in the gating system of the mould, the cooling well should be enlarged, the runner, polishing sprue, splitter and gate should be increased.
(3) The material temperature and mold temperature are low, if necessary, the gate local heating method can be used.
(4) The injection molding 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 should be fully plasticized, but the degradation of materials should be prevented. The heating should be stable and the cooling should be sufficient, especially for thick wall ones.
(6) To prevent cold material from entering the parts, use self-locking spring or reduce the nozzle temperature if necessary.
(7) Too much recycled materials, poor quality of plastics or colorants, mixed with water vapor or other impurities, and poor quality of lubricants used.
(8) The clamping force should be enough.