Precautions for metal powder spraying

As we all know, in the process of metal powder spraying, the powder coating is flowed through the air flow to the spray gun, the spray gun is transmitted to the spray gun through the high-pressure electrostration generator, the electrode needle of the nozzle generates corona discharge, a dense negative charge is generated near the electrode, the powder is equitised from the gun head, the captured charge becomes a charged powder, in the air flow, electric field and its own gravity, flying to the grounding parts, and adsorption on the surface of the profile. Therefore, in our spraying process, we need to do a good job of prevention.
1. Coating method of metal powder spraying
In most cases, the use of electrostitive spray gun for coating, because this type of product contains metal pigments, in the use of electrostation gun construction should ensure the good grounding of the system, while setting a lower electrostectrectectectectectectectectrelectrelectrelectraught voltage and powdering, to prevent spraying when the phenomenon of fire
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. The effect of filming has a lot to do with the setting, quality or brand of the spray gun. After a long period of spraying, a large amount of metal powder may accumulate at the spray gun discharge needle, requiring the builder to clean the discharge needle on a timed period.
2. Gloss of metal powder coatings
In most cases, due to large errors, it is not recommended to use a gloss meter to measure the gloss of the metal appearance coating film, but only to use visual contrast to determine whether it is consistent with the standard model.
3. Recyclability of metal powder coatings
For powders manufactured using dry mixing, due to the separation of the process of spraying and recycling, there will be some differences between recycled powder and new powder in the metal pigment content, which may lead to inconsistent appearance of the coating film, color bias phenomenon. This is due to the difference in properties between metal pigments and powder particles. Experts recommend a ratio of at least 1:4 between recycled powders and new powders. If a powder coating is manufactured using bonding fixation, the recycled powder can be reused due to the relatively fixed ratio between the metal pigment and the powder particles.
4. The hood gloss layer of metal powder coating
the re-spraying of the hood gloss layer on the metal powder coating film has the following advantages: enhancing the anti-stone performance of the metal powder coating film; In order to ensure the appearance of the hood gloss layer, it is required that the first sprayed work piece can not be contaminated with any. Therefore, it is generally necessary to have fully automated spray lines and two separate spray houses for separate coating. It is recommended not to spray the hood light layer in general.
5. The scratchability of metal pigments
whether it is made by dry mixing or by bonding fixation, can not completely solve the problem of the scratchability of metal pigments. The only way to solve the scratchability is to apply a transparent coating to the metal powder coating.
6. Try to maintain the stability of the spraying conditions
use the same spray equipment, use the same voltage, air pressure and other parameters, try to keep the distance between the spray gun and the work parts unchanged, try to maintain the stability of the film thickness, ensure that the powder coating before spraying has been fully fluidized When using recycled powder, ensure that the ratio of recycled powder to new powder is as low as 1:4, avoid spraying complex or deeply dented work parts with metal powder coating, and it is recommended that multiple work pieces used to assemble together should be sprayed at the same time.