The main reasons and solutions for uneven color of injection molded products are as follows:
(1) Colorant diffusion is poor, which often causes patterns to appear near the gate.
(2) Plastics or colorants have poor thermal stability. To stabilize the color tone of parts, production conditions must be strictly fixed, especially material temperature, material quantity and production cycle.
(3) For crystalline plastics, try to keep the cooling rate of all parts of the part consistent. For parts with large wall thickness differences, colorants can be used to mask the color difference. For parts with more uniform wall thicknesses, the material temperature and mold temperature must be fixed. .
(4) The shape and gate form and position of the part have an impact on the plastic filling, causing color differences in some parts of the part, and must be modified if necessary.
Problem solving list
| Product problem | Causes | Solution |
| 1，The temperature of the barrel, nozzle and mold is lowincrease temperature | Increase temperature | |
| 2，Back pressure is too small | Increase back pressure | |
| 3，Injection pressure is too low | Raise pressure | |
| Mixed colors | 4，Injection speed is too slow | Increase injection speed |
| 5，The mixer is not cleaned | Clean the mixer | |
| 6，The barrel is not cleaned | Clean the barrel | |
| 7，The crusher is not cleaned | Clean the shredder | |
| 8，Toner compatibility is too poor | Change to toner, diffusing agent or granules with good compatibility |
