Surface potential measurements for predicting film thickness of electrostatically sprayed powders

This paper investigates the possible correlation between the surface potential of electrostatically sprayed powders prior to bake to their cured film thickness. In this study, two different methods were used for supplying the powder to the spray gun. The first method used a fluidized bed (conventional system). The second series of tests were performed with a vibrating trough that delivered a fixed amount of powder (in-house setup). The experimental data does show that correlation does exist between the film thickness and the surface potential, but a single correlation factor can only be established for a fixed set of spraying conditions.