Electroseparation and efficiency of deposition during electrostatic powder coating

In the paper the full-size laboratory stand for electrostatic powder deposition efficiency measurements is described. This stand is equipped with powder coating booth, suitable transducers and computer data acquisition system. Results obtained for different kinds of powder paints, different workpiece shapes and different spraying heads (high voltage, tribo) are presented. During electrostatic powder paint deposition the electroseparation process also proceeds. Most powder paints are polydisperse powders. Efficiency of deposition of each size fraction is different. So the grain size analysis gives different distribution for fresh and recovered powders. Results of grain size analysis of powder paint samples are presented. Mathematical model of electrostatic powder deposition has been described. The results explain the deposition process and allow to compare different kinds of spraying heads, different kinds of powder paints and powder recovery process. They also help to plan technology of powder coating process and design powder recovery system.