The correct selection and setup of powder feeders, pumps, hoses, and spray guns strongly affects the final finish. Powder can affect the result of the process as well. The powder particles’ size distribution is critical to successful powder coating. Once powder is ground, a laser inspects it and a statistical report is issued. This report indicates the majority size of the particles. The grinding process used in powder production is unable to make every particle exactly the same size. Some particles are coarse and some are fine. Neither extreme is able to take on good charging characteristics. Many powder-coating systems rely on reciprocating equipment to paint products. Automatic guns are the best choice for uniformity and consistency in the finishing application. Automatic guns provide film thickness and even particle distribution. They generally require more over sprayed powder to be collected and recycled for reuse. Keeping the powder in a dry place and making certain each box is properly resealed ensures a quality product next time it is needed. Most paint operations require that some parts be masked prior to painting.
By Gary Conner
By George N Bullen FSME