33
Samand
Technical description
The first anti-corrosion steps are taken in the body
shop. Galvanised sheet steel is used for those parts of
the body that are most exposed to corrosion. See also
technical description, Galvanised body parts.
1
Cleaning
the bodywork from the body shop.
When the body comes to the paint shop it is
initially cleaned to remove all the mechanical
processing residue and most of the grease and oil
that has resulted form the body assembly.
2
Degreasing.
To attain as good a base a possible
for the continued surface treatment, the rest of the
grease deposits are removed from the body with
an alkali degreasing agent.
3
Phosphatizing.
Phosphatizing gives the metal a
good basic protection and foundation for the
primer. Temperature 52Þc - 55Þc.
4
Washing.
The body is washed to remove residue
from phosphatizing.
5
Electrocoating (ED).
The body is lowered into a
bath containing anti-corrosion paint and a
negative electric current is led to the body. The
positively charge paint particles are drawn to the
body in the same way as iron fillings to a magnet.
In this way, a layer of anti-corrosion paint covers
the entire body, hollow sections, joints, etc.
6
Oven hardening.
The paint from the
electrocoating is hardened for ?? minutes after
the body has reached a temperature of 175Þc +
5Þc.
7
Noise suppression mats.
Noise suppression
mats are placed at strategic points in the body to
reduce resonance.
8
Sealing.
Seams and joints over the whole body
are sealed with PVC sealant. This is mainly to
prevent damp from entering but it also acts as a
sound insulator.
9
Oven hardening.
The body passes through an
oven to cure the sealant. The sound absorbing
panels soften slightly at this time and shape
themselves to the contours of the body.
10
Inspection and grinding.
Any dust particles and
paint run are removed.
11
Cleaning.
Dust is removed from the body.
12
Intermediate coat.
The intermediate coat forms a
good base for the top coat, for both its adhesion
and its appearance. The intermediate coat also
contributes to the corrosion protection by
withstanding stone chipping. The paint is applied
by a robot with rotation cups. When the cups
rotate, a fine spray is formed which migrates to
the body and gives it an even coat. Interior
surfaces that are difficult to reach are painted
manually.
13
Inspection.
After the intermediate coat the body
is vigorously inspected.
14
Oven hardening.
The intermediate coat is
hardened for ?? minutes at + 145Þc + 5Þc.
15
Grinding.
Any dust particles and paint runs are
levelled off.
16
Cleaning.
Grinding dust and other foreign
particles are removed from the body so that it is
absolutely clean before the top coat is applied.
17
Anti-corrosive treatment.
Penetrating wax is
injected into hollow sections in the sills, members,
etc.
18
Oven hardening.
The body is heated to
40Þc - 50Þc for ?? minutes so that the hollow
section wax will spread throughout the hollow
sections and dry.
19
Top coat.
The top coat is applied in the same
way as the intermediate coat with robots fitted
with rotation cups. Metallic paint is applied in two
coats. First a thin coat with a high pigment
content and then a thick coat of clear enamel to
protect the pigment and give it a high gloss.
20
Oven hardening.
The top coat is hardened at a
temperature of 145Þc + 5Þc.
21
Final inspection.
After painting, the body is
inspected rigorously. If any paint run, scratches or
dust particles are found in the paint or if there is
any damage in the coating, the body is returned
for paint repair before going on to the next station.
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