Metal powder coating method and precautions

Abstract: First, the coating method of metal powder coating friction spray gun is generally not suitable for metal powder coating spraying. Since this type of product contains metallic pigments, it should be ensured that the system is well grounded when using an electrostatic gun, and at the same time, set a lower electrostatic voltage and powder output to prevent ignition during spraying.

Metal powder coating refers to a variety of powder coatings containing metallic pigments (eg, copper gold powder, silver aluminum powder, etc.). As the metal powder coating can display a bright, luxurious decorative effect, it is very suitable for spraying indoor and outdoor objects such as furniture, accessories and automobiles.

In the manufacturing process, dry-blending is currently used in the domestic market, and Bonding is also used internationally. First, the coating method of metal powder coating The friction spray gun is generally not suitable for metal powder coating spraying.

Metal powder coating method and precautions

In most cases, it is recommended to use an electrostatic spray gun for half-loading. Since this type of product contains metallic pigments, it should be ensured that the system is well grounded when using an electrostatic gun, and at the same time set a lower electrostatic voltage and powder output to prevent ignition during spraying.

The effect of forming a coating has a lot to do with the setting, quality or brand of the spray gun. After spraying for a long time, a large amount of metal powder may accumulate at the discharge needle of the gun, requiring the operator to regularly clean the discharge needle.

Second, the gloss of the metal powder coating In most cases, due to large errors, we do not recommend the use of gloss meter to measure the gloss of the metal appearance of the coating, and only use visual contrast method to determine whether the same with the standard model. Third, the recyclability of metal powder coatings For powders produced by the dry-blending method, due to the separation phenomenon during the spraying and recycling process, there will be some differences in the content of the metal pigments between the recycled powder and the new powder, which may lead to The appearance of the coating is inconsistent and color cast occurs.

This is due to the difference in properties between the metallic pigment and the powder particles. Experts from China Epoxy Resin Industry Association suggest that the ratio of recycled powder to new powder be at least 1:4.

If a powder coating made using a bond fixing method is used, since the ratio between the metal pigment and the powder particles is relatively fixed, the recycled powder can be completely reused. Fourth, the metal powder coating of the varnish layer on the metal powder coating film coating layer has the following advantages: enhanced metal powder coating film resistance to stone impact; increase the appearance of metal powder coating film; completely solve the metal pigment can Slip; improve the weather resistance of metal powder coating.

In order to ensure the appearance of the overcoat layer, it is required that the workpieces coated for the first time must not be contaminated. Therefore, a fully automated spray line and two separate spray booths are generally required for separate coating.

It is recommended that you do not spray the overlay under normal conditions. Use only when the requirements are very high, such as high-end appliances, car wheels, and outdoor use (to ensure weatherability).

V. Scrubability of metallic pigments Whether it is a powder produced by a dry-blending method or a bond-fixing method, the problem of the fallibility of metallic pigments cannot be completely solved. The only way to solve the problem of smearability is to spray a clear coat on the metal powder coating.

Sixth, to maintain a consistent appearance of the metal powder coating method 1, for the same product, try to use the same batch of metal powder coating, to avoid the poor batch of powder coating problems. Try to keep the spraying conditions stable.

Use the same set of spraying equipment, use the same voltage, air pressure and other parameters; try to keep the distance between the spray gun and the workpiece as much as possible to maintain the stability of the film thickness; to ensure that the powder coating has been fully fluidized before spraying; use recycling powder, should ensure the recovery The ratio of powder to new powder is as low as 1:4; try to avoid the use of metal powder coating spray pattern complex or deep depression of the workpiece; we recommend that for the assembly of multiple workpieces should be sprayed together. U.S. paint and coatings fell sharply. In the first quarter of this year, the global economy continued to slump and market demand continued to soften. Under this predicament, US paint and coating manufacturers issued pessimistic performance reports, which led to a sharp decline in their performance and even a loss.