Causes and treatment methods of dyeing, blooming, and color jumping in die-casting aluminum oxidation coloring:
The pH value of the dye liquor is low, and it can adjust to the standard worth with dilute ammonia water.
Not clean. Keep washing until clean.
The dye did not dissolve completely. Dissolution is dense until complete dissolution.
The temperature of the dye liquor is too high, and the temperature needs to be lower.
The pores of the oxide film are small, and the oxidation temperature is too low to prevent the oxide film from being dissolved by sulfuric acid. The oxidation temperature needs to be adjusted.
If the dyeing is too fast, the secondary dyeing time is too short. It is necessary to adjust the diluted dye solution, reduce the dyeing temperature and prolong the coloring time.
The sealing temperature is too low, and heating will solve it.
If the pH value of the sealing solution is too low, use dilute ammonia water to adjust to the standard value.
The stained surface is easy to wipe off, and the paint film is rough, which is generally caused by excessive oxidation temperature. The oxidation temperature should keep within the specified range.