Self-Study Program

53
Cataphoretic immersion paint primary
coating (CIP primary coating)
After the phosphating process the body
receives a cataphoretic primary coating,
which provides an excellent protection
against oxidisation.
Cataphoresis (movement of positively
charged particles through a liquid) is an
electrical process which is also known as
electrophoresis (transport of electrically
charged particles through an electrical
current).
The body is fully immersed in a tank
containing a paint-electrolyte solution.
It is connected to the negative terminal of a
DC power supply. A series of anodes arranged
around the tank form the positive terminal.
In the electrical field the positively charged
paint particles deposit themselves through
the field forces on the negatively charged
body.
Advantages
– All outer surfaces, inner surfaces and
cavities are coated.
– The thickness of the layer is uniform.
CIP primary coating produces a layer of paint
up to 20 µm thick on the body.
Any non-adhering paint residues are removed
in the following rinsing zones.
The last rinse is with fully demineralised
water.
The body (free of water droplets) moves on to
the drier. There the CIP primary coating
hardens at a temperature of 180
o
C.
The parts delivered from the factory are also
already coated with a CIP primary coating.
SSP239_068
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