Numerical simulation of electrical field distribution in tribo-powder coating of conducting cylindrical objects

The electric conditions in tribo-powder coating of cylindrical objects, such as car wheels, are analyzed. The authors present a numerical model for predicting the electric field distribution between a tribo gun and a cylindrical object. It is assumed that the particle distribution is governed primarily by the air flow and that the only source of the electric field is the space charge of the tribocharged particles. Simplified models for the field lines and design configuration are assumed, and the electric field is determined by means of the charge simulation method. The very high electric field found on all sharp edges of the coated object suggests the possibility of back-corona generation, and this was confirmed by the experimental observations