Safety aspects of electrostatic paint, powder and flock spraying processes

Abstract

Electrostatic coating processes apply high voltages of the order of 100 kV to electrically charge the spraying material which is then precipitated on the surface of the workpiece to be coated, making use of the resulting electrostatic attractive forces. A variety of electrostatic spraying equipment is in use, ranging from the hand-held electrostatic spray guns to the large electrostatic spraying installations for painting car bodies. The materials sprayed are liquid paint, powders and flock. As these materials are flammable, their use may constitute an ignition hazard. Moreover, as high voltages are applied, there may be the risk of electric shock to persons. In a survey, the major safety requirements for the prevention of both the risk of ignition and the risk of electric shock are dealt with, due regard being given to the different types of spraying equipment and spraying materials. In addition, special problems such as the use of triboelectric spray guns or the use of water-based paints has been given some consideration. The safety requirements are based on the European Standards EN 50050 and 50053 parts 1 to 3 for hand-held electrostatic spraying equipment and the European Standards for automatic electrostatic spraying installations which are in preparation.