Electrophoresis process:

The general process of anodic electrophoresis is: pre-treatment of the workpiece (oil removal → hot water washing → rust removal → cold water washing → phosphating → hot water washing → passivation) → anodic electrophoresis → post treatment of the workpiece (water washing → drying).

1. Remove oil. The solution is generally a hot alkaline chemical degreasing liquid with a temperature of 60 ° C (heated by steam) and a time of about 20 minutes.

2. Wash in hot water. The temperature was 60 ° C (steam heating), and the time was 2 minutes.

3. Remove rust. Use H2SO4 or HCl, such as hydrochloric acid rust remover, the total acidity of HCl is ≥43 points; the free acidity is> 41 points; add detergent 1.5%; wash at room temperature for 10-20 minutes.

4. Wash in cold water. Rinse in cold water for 1 minute while flowing.

5. Phosphating. Phosphating at medium temperature (10min at 60 ° C), commercially available finished phosphating solution can be used.

The above steps can also be replaced by sandblasting → washing.

6. Passivation. Use the medicine matching the phosphating solution (provided by the manufacturer of the selling phosphating solution), and it can be done at room temperature for 1-2 minutes.

7. Anodic electrophoresis. Electrolyte composition: H08-1 black electrophoretic paint, solid content 9% ~ 12%, distilled water quality 88% ~ 91%. Voltage: (70 ± 10) V; Time: 2 ~ 2.5min; Paint liquid temperature: 15 ~ 35 ℃; Paint liquid PH value: 8 ~ 8.5. Note that the work piece must be powered off and in and out of the slot. During the electrophoresis process, the current will gradually decrease as the paint film thickens.

8. Wash with water. Wash in running cold water.

9. Drying. It can be dried in an oven at (165 ± 5) ℃ for 40 ~ 60min.