What Is Powder Coating?

Definition:  Powder coating is the process of coating a surface in which a powder material is applied using an electrostatic or compressed air method. The applied powder is then heated (cured) to its melting point, after which it flows to form a smooth film which dries to a firm, durable finish very resistent to scratches, cracking, peeling, UV rays and rust.

The entire powder coating process involves several steps.

Very generally:

• a blasting, stripping and/or solvent cleaning step to insure the substrate is free of any oils, dirt, rust, mill scale, etc;
• a pretreatment step (an important step not done by all coaters) during which the product is treated with a pretreatment chemical or conversion coating, usually phosphate or zinc based, to further protect it and improve the surface for powder adherence;
• rinse, rinse, rinse..dry completely then
• powder coat, usually done with an electrostatic gun, but sometimes in a fluidized bed;
• finally, FULLY cure the powder in the oven, generally at 375-400 deg. F, 15-20 minutes (varies) , making sure the oven is preheated to temp

Advantages of Powder Coating

Although a finish represents only one attribute of a coated part, it is the most visible and influential characteristic to the consumer. Powder coatings have a positive impact on the consumer, both directly and indirectly, and provide solutions to issues of public concern. Powder coatings have become the coating technology of choice for consumable goods from toolboxes, bicycles, office furniture, and lawn furniture to widespread markets such as appliance and automotive for the reasons listed below.

QUALITY: The unique rheological and application characteristics of powder coatings provide superior consistency and uniformity of finish without sags, drips, runs, or bubbles. They provide extremely tough, durable films, enhancing the high quality, value-added image of consumer products. In general, the performance properties, such as impact resistance, flexibility, and corrosion resistance, of powder coatings are better than with liquid paints. Powder coated parts resist cracking, peeling, and marring during handling and normal service use. In many cases, merchandise is specifically being advertised as "POWDER COATED" because of the quality image it projects.

ECONOMICS: Powder coatings are frequently a cost saving alternative to liquid paints with respect to energy savings, labor costs, rework costs, material usage, waste disposal, and overall line efficiency. The advantage to manufacturers and the consumers is a coated part with a superior quality finish at a reasonable cost.

ENVIRONMENTAL: Environmental issues are of significant interest and importance to the government and general public today. Unlike many liquid paints, powder coatings are compliant with environmental regulations. Liquid paints often contain solvents, which can contribute to air pollution and, in some cases, ozone depletion. Powder coatings are free of such pollutants. Wet painting processes can generate sludge, which must be disposed of into hazardous waste landfills. Properly formulated powder coatings generate no such hazardous waste. The consumer can feel good about buying a powder-coated product, which is ENVIRONMENTALLY RESPONSIBLE.