Powder coating

Powdered paint is sprayed onto the cleaned product. In the process of spraying, particles of powder paint are electrically charged from an external source or by electrification by friction. By the electric field, the particles of powder paint are transferred to the product to be painted, which has the opposite charge. Particles of powder paint that have settled on the product are captured in the spray booth and can be used for re-spraying, which is not possible with conventional liquid paints. Next, the product with the applied powder paint is transferred to the polymerization chamber for “baking" the paint.

In the process of coating formation from the applied powder layer, a monolithic high-quality coating is created on the surface of the product.

The process of coating formation is carried out by heating the layer of powder paint to the state of its fusion with the formation of a monolithic layer. During subsequent processing, a solid film forms as a result of hardening (for thermoset materials) or cooling (for thermoplastic materials) of the layer.

The reflow of powder paints is divided into three stages: 1) the powder is melted and passes into a viscous-fluid state; 2) a monolithic layer is formed of melted powder particles; 3) the painted surface is wetted by the molten polymer, as a result of which a coating is formed.

Key Applications

• coloring of any metal components for products;
• staining of finished metal products that withstand heat up to 200 degrees Celsius;
• staining of ceramics and wall stones;
• staining of MDF , glass.

The list of products that can be painted with powder paints is quite wide. There are industries where the rate of consumption of powder paints is growing particularly rapidly. An example is the coating of the inner surface of pipes for oil wells and pumping oil, operating in conditions where factors such as high pressure, high temperatures and the presence of corrosive media can have a destructive effect on almost all coatings (with rare exceptions).

Powder Coating Equipment

Powder paints are applied to parts either by electrostatic spraying, or by immersion in a fluidized bed of powder paint (with or without electrification of particles), or by flame spraying.

The Swiss company GEMA in the early 70s for the first time in the world successfully introduced a high-voltage cascade into a spray gun.

For baking powder paint, polymerization ovens are used. The polymerization furnace is a closed chamber, the internal working volume of which is heated to the temperature necessary for polymerization. The product to be painted is placed inside the chamber, where the polymerization of the powder coating takes place.

• Powder coating (video)