Spraying advantages of electrostatic powder friction spray gun for complex parts
Because of the high efficiency of powdering the friction gun, it can also obtain higher economic benefits for a variety of color changing requirements and the use of non recovery systems in small batch production. The flexibility of production makes the application manufacturers more competitive in the product variety.
Tribological guns have good penetration performance when spraying complex parts, such as all kinds of aluminum and deep groove parts.
The use of friction guns requires special friction powder. With the continuous improvement of the level of powder production, more and more powder manufacturers produce spray powders suitable for high pressure guns and friction guns.
Spray powder is usually made up of three different sizes of powder particles:
Fine particles: less than 20 microns
Medium particles: 20 - 45 microns
Coarse particles: more than 45 microns
The difference of the different friction and electrostatic effects of different size particles is obvious. The smaller particles can get larger contact friction effect when the friction tube is passed through the friction gun, and the chance of collision with the wall of the tube is greater. Therefore, the effect of friction charging can be achieved quickly. The medium particle powder is suitable for the application of the friction gun spraying.
The advantages of the friction gun
1. Full automatic spraying can be used to save labor.
2. Compared with the high voltage electrostatic gun, the surface quality is more perfect and smoother.
3, the surface coating uniformity is perfect.
4, overcoming the Faraday effect is especially effective for spraying complex parts.
5, high powder rate, reduce the investment cost of equipment
A smooth surface quality can be obtained by friction spraying
Generally, the surface quality of the friction spraying is more smooth and smooth than the high voltage electrostatic gun spray. It is because the friction spray powder will not produce electrostatic repulsion on the workpiece and overcome the "orange peel effect". The "orange peel effect" of powder electrostatic is usually produced in the following circumstances:
1. When the powder particles are stacked on the surface of the workpiece, the particles in the outer layer can not be fully grounded and exclude each other, and the powder particles that continue to be sprayed to the workpiece will be repulsive, which affects the efficiency of the powder and the surface quality. On the surface of workpieces, surface roughness and even blistering may occur.
2, too much powder may cause a slight gap between the coating and the surface of the workpiece, resulting in the surface of the orange peel.
3. High voltage static electricity. The high voltage of powder can also cause orange peel on the coating surface. This phenomenon can be avoided when the friction gun is sprayed.
4, the leveling and curing process is not perfect, the temperature distribution in the curing furnace is uneven, and the workpiece temperature rise is not complete.
Precautions for spray gun spraying
1. The first friction gun is used to spray the workpiece at the initial stage when spraying, so as to achieve the grounding effect of the workpiece. This can make the workpiece produce a similar "preheating" effect and improve the efficiency of the rear coating.
2. Adjust the spray angle between the spray gun and the workpiece so as to make the workpiece and the spray powder contact as long as possible. Try to make the spray powder and workpiece have greater contact time.
3. When spraying the workpiece with deep groove, two sets of guns can be used. The first set of guns is sprayed on the deep groove by the high distance of the powder, and the deep groove can be sprayed because of the close distance between the nozzle and the workpiece. The second sets of spray guns are far away from the workpiece and spray at the outside of the workpiece at low speed with a small amount of powder output.
4, avoid the interleaving of the spray gun's spray amplitude, and the interleaving of the spray can not improve the spraying effect, but it will cause confusion of spray amplitude.