BodySpray guns and their use
| The gun is the most important tool for the painter, in order
to obtain a perfect-quality painting. With the help of compressed
air, the mixed enamel is applied over the surface. Compressed air
and enamel pass through the gun via separate channels. The exit point
of air and enamel is called the „hot point“. |
| Regulation of the paint gun |
| The amount of material is determined by the alteration in
the length of the enamel needle. Regulation is checked with a sample
of paint on cardboard or plate, at an appropriate distance. |
| With the air passage regulation wheel the work pressure is
chosen depending on the material and technical determinations. In
addition, it is through the regulation wheel that the form of the
spray cone is chosen. A spray cone as a high concentration of enamel,
and a small concentration of enamel. The compressed air pressure is
also determined by the size of the drops. |
| High pressure = small paint drops |
| Low pressure = large paint drops |
| With the spray regulation it is possible to continuously regulate
the round spray to plain spray. In the round spray, the air leaves
from the central hole in the air cap. The air channels in the air
cap are closed by the regulation screw, so that a conical enamel spray
occurs. In the plain spray, the air channels of the bit holes of the
horn are released by the opening of the regulation screw. The spray
in the form of a cone may now be conformed in the form of an ellipse
until the plain spray. By additionally turning the air cap, the spray
may come out either vertically or horizontally.+ |
| t
| Prior to painting, check if the baffle is appropriate for the
enamel to be used: heavy stuffing materials need a large opening of
the baffle, the less viscous materials need smaller baffle openings.
As a matter of principle, a complete set of baffles must always be
replaced |
| t
| After regulating the gun, the application of enamel is carried
out. The distance to the part to be painted must always be equal. |
| t
| The types of spray guns are classified per high and low pressure
guns. |
| High pressure guns have the disadvantage of high consumption
of energy and material. However, up to now they are the most commonly
used ones. The pressure required by them is between 1 - 6 bar. In
this case, baffles of sizes 1 -2,2mm may be used. For 1 l of enamel,
an amount of compressed air of approximately 400 l is required. An
oil purger and a water purger are also absolutely necessary. The high
air pressure and the large amount of air necessary cause a strong
paint cloud. The consequence is that the efficiency of the application
is only approximately 35%. |
| These are increasingly getting acceptance. They have the advantage
of forming a reduced cloud and so the performance rate of the application
of enamel is 65 %. The necessary pressure is between 1 - 5 bar. In
this case, baffles of sizes 1 -2,2mm may be used. Approximately 300
l of compressed air are for 1 l of enamel. |
| Several types of spray guns are offered, all designed for
specific types of work. They must meet the following criteria: |
| t
| Good ergonomics and handling |
| t
| Tireless work and with little physical effort |
|
|
|
| It is a gun with an enamel cup installed on top. The material
reaches the baffle via the force of gravity. At the outlet, the compressed
air spray causes a vacuum at the outlet of the air vent, in front
of the paint baffle. This vacuum sucks the enamel, which is under
atmospheric pressure, from the cup. Attention should be paid so that
the pressure compensating hole on the container cover is always open. |
|
|
|
| It is a gun with an enamel cup installed at the lower end.
The operation of this gun is almost identical to that of the flow
cup gun, via gravity. In this case the enamel is also sucked from
the paint cup by the vacuum generated by a compressed air spray. |
| This type of gun is mainly used in the industrial area, for
painting trucks or buses. In this case, the material is conveyed to
the spray gun under pressure, as the paint baffle and the air baffle
end um aligned, so there is no vacuum to such the material from the
cup. This gun is also used for heavy painting material, or to facilitate
the constant refilling of the enamel cup, on large surfaces. |
|
|
|
| This gun is used for the manifold painting of Design and Airbrush.
The amount of material of this round spray gun may be changed continuously,
hence it is also usable to draw finer lines. The sizes of the baffles
are from 0.2 to 1.0 mm, and may be also used for enamels that are
soluble in water. |
| This high-performance gun forms a soft, fine and homogeneous
spray. The reduced pressure of 0.7 bar provide a high index of material
application with a reduced cloud. The reduced internal pressure of
the baffle reduces the regression of the droplets of enamel from the
object and so also the parcel of „Overspray“. At the
same time, less solvent evaporates into the atmosphere. This allows
for a wide and uniform application of enamel for high-quality surfaces.
It application is primarily intended for water-soluble enamels. However,
even in the conventional field it provides excellent results in work
with coating and base enamels, as well as with colorless enamels.
With the high performance of material, it obtains savings of up to
15% with the coating enamels The higher productivity thus obtained
has also a positive effect on the environmental sociability and the
working conditions. |
| According to a study of the Residue Handling Consultant Baden-Württemberg
(ABAG), the advantages are: |
| t
| High degree of productivity of the application |
| t
| Lower consumption of material |
| t
| Lower emissions of solvent |
| t
| Reduced volume of waste products |
| t
| Higher durability of the filters |
| t
| Lower maintenance of the painting systems |
| t
| Lower waste sanitation costs |
| Cleaning of spray guns (painting system with
a solvent base) |
|
|
|
| In order to ensure the good operation of the spray guns for
a long time, a careful cleaning is necessary after each use. Otherwise
the paint material may dry in a short time, and later its removal
is very difficult. |
| t
| After use, clean the enamel cup immediately |
| t
| Rinse the gun with diluent |
| t
| For a careful cleaning the gun must be disassembled |
| t
| Clean the air cap with an appropriate brush |
| t
| For holes and baffles, use only baffle cleaning needles |
| Automatic gun washing system (paint system with
solvent base) |
|
|
|
| This consists of an hermetically close chamber. The guns and
tools to be cleaned are placed in this chamber. After closing the
cover, a pneumatic pump is turned on, which distributes the cleaning
product in the system. After the cleaning process is finished or when
the cover is opened, the pump is turned off. |
Note | After cleaning the spray gun, remove the diluent in order not
to damage the sealing and gaskets. |
|
|
|
02 Body & interior
