What is powder coating?

Powder coating is a dry finishing process that has become extremely popular since its introduction in North America over in the 1960s.  Representing over 15% of the total industrial finishing market, powder is used on a wide array of products. More and more companies specify powder coatings for a high-quality, durable finish, allowing for maximized production, improved efficiencies, and simplified environmental compliance.  Used as functional (protective) and decorative finishes, powder coatings are available in an almost limitless range of colors and textures, and technological advancements have resulted in excellent performance properties.How Powder Coating WorksPowder coatings are based on polymer resin systems, combined with curatives, pigments, leveling agents, flow modifiers, and other additives.  These ingredients are melt mixed, cooled, and ground into a uniform powder similar to baking flour.  A process called electrostatic spray deposition (ESD) is typically used to achieve the application of the powder coating to a metal substrate.  This application method uses a spray gun, which applies an electrostatic charge to the powder particles, which are then attracted to the grounded part.  After application of the powder coating, the parts enter a curing oven where, with the addition of heat, the coating chemically reacts to produce long molecular chains, resulting in high cross-link density. These molecular chains are very resistant to breakdown.  This type of application is the most common method of applying powders.  Powder coatings can also be applied to non-metallic substrates such as plastics and medium density fiberboard (MDF).Sometimes a powder coating is applied during a fluidized bed application.  Preheated parts are dipped in a hopper of fluidizing powder and the coating melts, and flows out on the part.  Post cure may be needed depending on the mass and temperature of the part and the type of powder used.  No matter which application process is utilized, powder coatings are easy to use, environmentally friendly, cost effective, and tough!
Powder coating line. Metal panels are suspended on an overhead conveyor line. Painting products in an electrostatic field.