Electrostatic painting Advantages and Disadvantages

Powder coatings are an advanced method for applying decorative and protective coatings to virtually any type of metal used by industry and consumers. The powder used in the process is a mixture of finely ground pigment and resin particles which are electrostatically sprayed onto the surface to be coated. The charged powder particles adhere to the electrically grounded surface until the powder is heated and melted into a smooth coating in the curing oven. The result is uniform, durable, high quality and attractive finish. This article will introduce the advantages and disadvantages of electrostatic powder coating.

Advantages of Electrostatic Powder Spray

1. Only for one electrostatic powder coating can achieve a coating of 100-300μm, but a common solvent coating requires 4-6 times. Electrostatic powder coating has good corrosion resistance.
2. Electrostatic powder coating has no solvent, no waste pollution, and the working conditions have been improved.
3. Powder coatings provides consumers, businesses and industries with the most economical, long lasting and most durable quality finishes available for virtually any type of metal. The powder coated surface is more resistant to wear, scratches, fading and wear than other surfaces. Color choices are almost limitless, including flat, satin, glossy, high gloss, metallic, candy, transparent, iridescent, fluorescent, wrinkle, hammer and glitter finishes. The colors stay bright and vibrant. Textures range from smooth surfaces to wrinkle or matte finishes, as well as rough textures designed to hide surface defects.
4. The use of new technologies such as electrostatic powder coating is high efficient to work, suitable for automatic coating lines. The powder has high utilization rate and can be recycled.
5. In addition to curable epoxy resins, polyesters, and acrylic resins, there are a large number of thermoplastic resins that can be used as electrostatic powder coating materials such as polyethylene, polypropylene, polystyrene, fluorinated polyether, nylon, and poly. Carbonate and various fluorine resins, etc.

Disadvantages of Electrostatic Powder Spray

1. Electrostatic powder coating requires the entire coating equipment, which is a huge investment if just small areas painting.
2. For the complex shape of the workpieces, the recessed holes are not easy to spray, and the coating of the protruding portions is not uniform, so electrostatic powder coating usually requires process adjustment or manual repair.
3. Electrostatic powder coating requires rigorous maintenance and management. Poor management or improper operation can result in electric shock, high-voltage breakdown discharge, and even fire accidents.
4. Specialized electrostatic spray equipment is required for application and the surface must be conductive to accept the charged paint particles. This limits the ability of powder coatings to penetrate well into parts that have deep recesses.
5. Powder coatings cannot be mixed with each other to obtain different colors, therefore mixing-machine/toner systems such as those used in liquid paint technologies are not an option. All powder colors must be produced to the final color match at the paint supplier’s factory.

Pre­treatment Process
1. Surface treatment and paint
Removal of oil, soil, lubrication greases, metal oxides, welding scales etc. is essential prior to the powder coating process to increase the adhesion and to prevent bubbles, cracks, and peels.
2. Purpose of Surface Treatment
a. Improves the corrosion resistance.
b. Clean the surface and improve the bonding of the powder to the surface
c. Gives the paint affinity and wettability.
d. Remove the unevenness to smooth the surface.

Below are two DP hot-selling Electrostatic Powder Coating System for reference.