What Is the Powder Coating Process?

Powder spraying uses powder spraying equipment (electrostatic spraying machine) to spray powder coating on the surface of the workpiece. Under the action of static electricity, the powder will be evenly adsorbed on the surface of the workpiece to form a powder coating; the powder coating is dried at high temperature. Baked and leveled and solidified to become the final coating with different effects (different types of powder coatings); the spraying effect of powder spraying is superior to the spraying process in terms of mechanical strength, adhesion, corrosion resistance, aging resistance, etc., and the cost is also Under the same effect spray paint.

Powder Coating

An electrostatic powder spraying system is mainly composed of a powder supply device, one or more electrostatic spray guns and control devices, a static electricity generating device (usually arranged in the electrostatic spray gun) and a powder recovery device.

Powder spraying uses the principle of electrostatic spraying to adsorb dry powders on

The coating is made of special resin, pigments, fillers, curing agents and other auxiliaries, mixed in a certain ratio, and then prepared by processes such as hot extrusion and crushing and sieving. They are stable in storage at room temperature. They can be electrostatically sprayed, friction sprayed (thermoset method) or fluidized bed dip-coated (thermoplastic method), then heated, baked, melted and solidified to form a flat and bright permanent coating film for decoration. And anti-corrosion purpose.

Its characteristics are:

1. This product is non-toxic, contains no solvents and does not contain volatile and toxic substances, so there is no pollution, no fire, no "three wastes" and other pollution problems, which fully meet the requirements of national environmental protection laws.

2. The utilization rate of raw materials is high. The powder produced by some well-known brand powder suppliers can be recycled. The highest utilization rate can even reach more than 99%.

3. After pre-treatment of the object to be coated, it can be applied in a one-time operation, without the need for primer coating, to obtain a coating film of sufficient thickness, easy to realize automatic operation, high production efficiency, and reduce costs.

4, the coating is dense, adhesion, impact strength and toughness are good, corner coverage is high, has excellent chemical resistance and electrical insulation properties.

5. Powder coating storage and transportation are safe and convenient.

(1) In order to make full use of the characteristics of powder coating and extend the service life of the coating film, the surface of the object to be coated must be strictly subjected to surface pretreatment.

(2) When spraying, the object to be coated must be completely grounded to increase the spraying efficiency of powder coating.

(3) For objects with large surface defects, conductive putty should be applied to ensure the flatness and smoothness of the coating film.

(4) After spraying, the objects need to be cured by heating. The curing conditions are subject to the technical specifications of the powder product, but the curing temperature and time must be fully guaranteed to avoid quality accidents caused by insufficient curing.

(5) Inspect immediately after powder spraying. If defects are found, they should be dealt with in a timely manner. If defects are found after curing, the scope is small and not affected. It also affects the surface quality. After sanding with sandpaper, spray again or remove the coating with paint remover, and then re-spray.

(6) The recovered powder must be screened to remove debris and mixed with new powder in a certain proportion.

(7) The powder supply barrel, powder spraying room and recovery system should avoid the pollution of other powders of different colors, so it must be cleaned every time the color is changed.

1. Keep away from fire and avoid direct sunlight. It should be placed in a well-ventilated place with a temperature below 35 ° C.

2. Avoid storing in places susceptible to contamination by water, organic solvents, oil and other materials.

3. Do not expose the powder coating to the air after use. Cover it or close the bag tightly at any time to avoid the inclusion of debris.

4. Avoid prolonged contact with the skin. Rinse the powder that adheres to the skin with soap and water. Do not use solvents. Safety of painting construction sites

5. The equipment used for painting work must be well grounded to eliminate static electricity.

6.Avoid endless discharge of coating machine

7. In the spraying room, the concentration of floating dust should be controlled below the safe concentration as far as possible to avoid the danger of dust explosion and fire.

With the promotion of environmental protection laws and regulations, limiting the VOC emissions will make powder spraying more widely used. If the coating line is compared with solvent-based and water-based coatings and comprehensively evaluated, powder spraying will replace other Painting. The future development trend of powder coating equipment is as follows.

(1) In order for powder spraying to be comprehensively evaluated in terms of coating film performance, coating cost, coating cost, and repayment of equipment investment, the entire industry related to powder coating needs to jointly organize research.

(2) In terms of powder coating equipment, an electrostatic fluidized bed coating equipment suitable for large-scale objects should be developed and designed, and a cleaning method for color change should be developed.

(3) In terms of powder coating technology, it is expected to further improve the coating efficiency of electrostatic coating, and to develop a rapid color change method and a recycling technology of exhaust air in the powder spraying room. ^[1]