Q
Several Tips for Eliminating Surface Particles in Aluminum Powder Spraying
A
Several Tips for Eliminating Surface Particles in Aluminum Powder Spraying

(1) Painting work environment

The production environment surrounding the dusting room will directly affect the surface quality of the coating. 
For the coating of the corona electrostatic spray gun , some of the dust and particles in the environment will be brought into the powder coating booth, and charged by the electrostatic effect. 
Impurities are adsorbed on the surface of the coating and become particles on the surface of the coating when the powder is melted and leveled. The clean production environment has a good effect on product quality. 
Persons entering the workshop shall wear on the work clothes and change shoes; do a good job of sanitary work in the workshop; often wipe the production equipment with a semi-moist cloth or use a vacuum cleaner to remove the dust from all parts of the workshop.


(2) Workpiece surface treatment
Generally powder-sprayed aluminum workpieces need go through the following process: shelf-degreasing-water-washing-chromatization-curing-discharging; impurities such as chromium residue in the surface treatment process may adhere to the workpiece. 
This results in the presence of particles after film formation.

(3) Control of Film thikcness
For spraying technicians, it is understand that if the film too thin, in addition to particles, it will produce poor leveling, severe orange peel, and poor hiding power of the light colors, while the acid and alkali resistance, Salt tolerance,water-tolerant and other performance of coating will be worse. Appropriate increase the thickness of coating can effectively reduce the formation of particles,
and not be too thick. Generally, if too thick will affect the size of workpiece, and the properties such as impact resistance, flexibility and adhesion will be reduced. Layer thickness control between 40~120um. We can control the film thickness in the following ways:
a. The number and arrangement of the spray guns in the powder spray booth. 
b. The powder output and air pressure of the spray gun (powder out, atomization, fluidization parameters)
c. Running speed. Chain speed.
d. Suspending method and arrangement of coated workpieces.

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