1. If the water washing is not fresh, the water washing shall be strengthened.
2. The water used for washing is too dirty and easy to pollute the film. At this time, the water should be replaced to ensure the laundry quality.
3. The oxide film is polluted by dust, acid and alkali fog in the air. Strengthening washing, timely staining and timely transfer can considerably reduce this symptom.
4. The oxide film is polluted by oil and sweat. The protection must be strengthened, and the appearance surface of the workpiece cannot be touched by hand.
5. There are insoluble impurities in the dye solution, which are polluted by oil and destroy normal dyeing. At this time, filter or replace the dye solution and clean the tank solution regularly.
6. Residual acid flows out of workpiece gaps and deep holes, and water washing shall be strengthened for such workpieces.
7. The dye solution is polluted, causing spot corrosion of the dyed workpiece. At this time, the dye must be replaced. At ordinary times, attention should be paid to avoid introducing impurity ions during operation.
