Electrostatic powder coating spray gun for complex parts without friction of spraying

Due to its high powder loading efficiency, friction guns can achieve high economic benefits for various color changing requirements and small batch production using non recycling systems. The flexibility of production allows application manufacturers to gain greater competitiveness in product variety.

Friction electrostatic guns can exert their advantages of good penetration performance when spraying complex workpieces (such as various aluminum profiles and deep groove workpieces).

The use effect of the friction gun requires the use of specialized friction powder. With the continuous improvement of powder production level, more and more powder manufacturers are producing spray powder suitable for high-pressure gun and friction gun applications.

Spray powder is usually composed of three different sizes of powder particles:

Fine particles: below 20 microns

Medium particles: 20-45 microns

Coarse particles: above 45 microns

The difference in frictional electrostatic effects caused by particles of different sizes is significant. Smaller particles can achieve greater contact friction effect when passing through the friction tube in the friction gun, and have a greater chance of colliding with the tube wall for friction. Therefore, the effect of friction charging can be quickly achieved. Medium particle powder is suitable for friction gun spraying applications.

Advantages of friction guns

1. Comprehensive automatic spraying can be used to save labor.

2. Compared to high-voltage electrostatic guns, the surface quality is more perfect and smooth.

3. The surface coating has perfect uniformity.

4. Overcoming the Faraday effect is particularly effective for spraying complex workpieces.

5. High powder loading rate reduces equipment investment costs

Friction spraying can achieve smoother surface quality

Usually, the surface quality obtained by friction spraying is smoother and smoother than that obtained by high-pressure electrostatic gun spraying. This is because friction spraying powder does not generate electrostatic repulsion on the workpiece due to accumulation, overcoming the resulting "orange peel effect". The "orange peel effect" of powder static electricity usually occurs when:

1. When powder particles accumulate too thick on the surface of the workpiece, the outer particles cannot be fully grounded, repel each other, and have a repulsive effect on the powder particles that continue to spray towards the workpiece, affecting the powder loading efficiency and surface quality. On the surface of the workpiece, there may be surface irregularities or even bubbles.

2. Excessive powder may also cause small gaps between the coating and the surface of the workpiece, resulting in an orange peel surface.

3. High voltage static electricity is too high. When the high voltage static electricity acting on the powder is too high, it can also cause orange peel on the surface of the coating. Friction gun spraying can avoid this phenomenon.

4. The leveling and curing process is incomplete, the temperature distribution in the curing furnace is uneven, and the temperature rise of the workpiece is incomplete.

Precautions for friction gun spraying

1. During spraying, the first friction gun is used to perform "initial" spraying on the sprayed workpiece to achieve the grounding effect of the workpiece. This can create a similar "preheating" effect on the workpiece and improve the powder loading efficiency of subsequent spraying.

2. Adjust the spraying angle between the spray gun and the workpiece to ensure that the workpiece has as long contact time as possible with the sprayed powder. Try to ensure that the sprayed powder has a longer contact time with the workpiece.

3. When spraying workpieces with deep grooves, two sets of guns can be used. The first group of guns sprays the interior of the deep groove at a high powder output at close range. Due to the close distance between the nozzle and the workpiece, the interior of the deep groove can be sprayed. The second group of spray guns is arranged far away from the workpiece and sprayed onto the outside of the workpiece at a low speed with a small amount of powder output.

4. Avoiding the intersection of spray gun spray amplitudes cannot improve the spraying effect, but can cause confusion in spray amplitudes.