Screen your powder before application

Screening of powder coating powder is very important,that will separate out contaminants, insure uniform particle size distribution,and allow the system operator to fine tune the application equipment without puffing or surging for maximum transfer efficiency and finish quality.

Actual on-line test results have shown that screened powder will cover much more area than the same material unscreened. The most common reason that powders puff and surge during application is due to the lack of screening. Powders may become compressed in transportation or in storage and will form large compacted groups of particles that will clog up feed hoses.

Powder should be screened into a clean dry hopper. Powders are manufactured by the manufacturer through an 80 mesh screen. The powder is light and fluffy when they make it. It may not be light and fluffy when you get it at your facility. If the powder manufacturer is screening though an 80 mesh screen, and you screen through a standard stainless steel window screen, the powder should fall through just as fast as you pour it in. That’s going to prevent you from introducing into your system, balls of coagulated powder that are going to clog your feed lines. What happens when you clog your feed lines? You get puffing and surging.