P98.00-0772-12
Cataphoretic electro-immersion priming
Cataphoretic immersion priming is the basis for permanent corrosion protection, in conjunction with filler and top coat.
With cataphoretic immersion priming the phosphatized bodies and detachable body parts are lowered into an immersion bath with water-based primer. By immersing the body at a special set angle, and due to the hole pattern in the body, air bubbles in cavities are avoided and an optimum coating of the cavity is achieved. An electric field is produced between the body and the immersion bath. The positively charged paint particles (anode) deposit themselves on the negatively charged body (cathode). The separation voltage and coating period (dwell time in immersion bath) are selected so that there is an even film of paint on the body and in its cavities. Once the bodies are moved out of the bath, the loose primer material is rinsed off with ultrafiltrate and demineralized water. The special advantage of cataphoretic immersion priming is the even coating in inaccessible areas such as cavities, corners and edges. With this process, the use of solvents which are hazardous to health and harmful to the environment can be greatly reduced.
Principle of cataphoretic immersion priming
C Positively charged paint particle
A Cathode (body, transport frame)
B Anode