Cathodic dip painting (KTL) operating principle |
A | Cathode (body, transport frame) |
B | Anode |
C | Positively charged paint particles |
P98.00-0772-12
The adhesion of the preceding phosphating process means that the cathodic dip painting (KTL) forms the basis for all subsequent sealing and coating processes as well as for permanent corrosion protection.
The special advantage of cathodic dip painting lies in the uniform coating of the vehicle's outer skin and the protection of all areas which are difficult to access such as body cavities, double plating, corners and edges. With cathodic dip painting, the phosphatized bodies and detachable body parts are lowered into an immersion bath with water-thinnable primer.
The immersion of the bodies at a specially-defined angle and the so-called hole pattern for the bodies help to prevent any air bubbles in cavities while also guaranteeing optimum cavity coating.
An electric field is generated between the body and the dip tank.
The positively charged paint particles (anode) are deposited on the negatively charged body (cathode), a uniform paint film is generated on the body and in the cavities.
After moving the body out of the tank, the loosely adhering primer is rinsed off.
Hazardous, polluting solvents can mainly be dispensed with in this procedure.