company news about How to improve the powder rate of spraying equipment?

How does the spraying equipment improve the powder rate?

1. There are many factors affecting the powder rate at the dead Angle of powder coating, of which the two main theoretical factors are the charging effect of powder and the shielding effect of Faraday cage.

2, the measures to solve the powder rate on the dead corner of the powder to improve the overall electrification of the formula, including the deployment of resin, fillers and auxiliaries, these three aspects are important factors affecting the powder rate on the spray powder.

3, the material powder coating is mainly composed of epoxy, polyester resin and other polymer compounds, these compounds have a high dielectric constant, so the electric field force is strong in the electric field, if only pure resin in the formula, the powder rate is good. However, due to the high price cost, generally do not use this way, powder manufacturers for their own market competition needs to reduce the cost of materials to add fillers, control the appropriate face base ratio, in which the addition of fine particle size filler, in the test, such as ultrafine barium sulfate, can improve the powder rate on the dead corner. 4, charged additives powder coating manufacturers are mostly by adding charged additives in the powder formula to achieve the powder rate on the dead corner. Generally add metal powder, organic matter, fine powder with large specific surface area, etc. The powder particles were crushed and classified by suitable ACM main and secondary grinding, and the particle size was normally distributed and the peak value was appropriate. However, the particle size itself is very fine, and its own fluidity is very weak, which is not conducive to the electrification of the powder and affects the powder rate at the dead corner of the powder. To improve the electrification of powder particles, fumed silica or fine alumina powder can also be added during extrusion and grinding. For example, the addition of Degussa's fumed silica and alumina C can effectively improve powder electrification and increase powder fluidity. 5, particle size and dead Angle powder rate relationship Most of the powder coating materials are high insulation performance materials, a certain particle size powder particles once it is difficult to disappear, and the resistivity of the powder is also large. At present, the powder factory generally controls the median diameter D50 at 32~40μm. The powder in this particle size range has a better coating rate in the electric field。

The particle with a coarser particle size has a large charged strength, is easier to pass through the Faraday shielding effect area, deposited on the surface of the workpiece, and the powder rate is good on the dead Angle: the powder particle size is small, the charge is small, in the electric field to overcome the adverse factors such as powder gravity and aerodynamic force, and the powder is difficult on the dead Angle. It can better overcome the dead Angle promoted by Faraday effect, and the powder particle size should be controlled within the range of 25~ 35μm. The fine particle size (≤10 μm) is controlled below 8%, the ultrafine powder is generally not charged, and the spraying process is mainly affected by air flow; The coarse particle size (≥ 70μm) is controlled below 3%, which can effectively avoid the problem of thick coating on the edge of the groove, and overcome the adverse factors such as the powder falling off the surface of the workpiece or the powder with a finer particle size being sucked away.