How to solve the uneven color of plastic products

Generally speaking, when the injection molding machine processes plastic products, the whole process will be very smooth, but occasionally there will be some problems, such as uneven color of injection molding products. Once it happens, it will actually cause great trouble to everyone. To solve this problem, injection molding machine manufacturers have their own methods to deal with it. First, we need to analyze the causes of this problem, and then apply the right medicine to the case, which will be easy.

The main causes and solutions of uneven color of injection molded products caused by injection molding are as follows:

1. The diffusion of colorant is poor, which often leads to patterns near the gate.

2. The thermal stability of plastics or colorants is poor. To stabilize the color tone of the parts, remember to strictly fix the production conditions of the injection molding machine, especially the material temperature, material quantity and production cycle.

3. For crystalline plastics, try to make the cooling rate of all parts of the parts consistent. For parts with large wall thickness difference, colorant can be used to mask the color difference. For parts with uniform wall thickness, the material temperature and mold temperature shall be fixed.

4. The shape, gate form and position of the part have an impact on the plastic filling, resulting in color difference in some parts of the part, which shall be modified if necessary.

Cause analysis of color and gloss defects of injection molded products:

Under normal circumstances, the gloss on the surface of injection molded parts of injection molding machine is mainly determined by the type of plastic, colorant and mold surface finish. However, the surface color, gloss defect, surface dark color and other defects of products are often caused by some other reasons. The causes and solutions are analyzed as follows:

1. Poor finish of the mold, rust on the surface of the cavity and poor exhaust of the mold.

2. If the gating system of the mold is defective, the cold well, runner, polishing sprue, shunt and gate shall be increased.

3. The material temperature and mold temperature are low. If necessary, local heating of the gate can be used.

4. The processing pressure of the injection molding machine 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 shall be fully plasticized, but the degradation of materials shall be prevented. The heating shall be stable and the cooling shall be sufficient, especially for thick wall.

6. Prevent cold materials from entering the parts. If necessary, the injection molding machine shall use self-locking spring or reduce the nozzle temperature.

7. Too much recycled materials are used, the quality of plastics or colorants is poor, water vapor or other impurities are mixed, and the quality of lubricants used is poor.

• The clamping force shall be sufficient.

By reading the above content, you must have some understanding of the solutions to the uneven color of plastic products. If you have any questions and want to consult, you can pay attention to our website or call the hotline at the bottom of the website. Welcome new and old customers to contact us for consultation, and we will serve you wholeheartedly.