Charge exchange model of a disperse system of spherical powder particles

This paper presents a charge exchange model of contact charging, based on surface state theory, between classes of insulating polymer particles. The goal of this model is to predict the average charge per particle by computing the overall charge exchange between different classes of particles until the system reaches equilibrium and charge exchange ceases. An iterative approach to the problem is presented as well as the analytical solution for the asymptotic state of the system. The results of the model verify previously published experimental data. The experimental data was obtained from measurements of tribocharged polymer particles inside a fluidized bed. The results show that a bipolarity of charge exists where the large and small size particles, for a given powder, are oppositely charged.