Estimation of Charge Distribution of Polymer Particles Based on New Contact Charging Model

Abstract

A new method for simulating the charging behavior of polymer particles was proposed as part of the fundamental investigation of the charging behavior of toner particles in an electrophotographic system. In this system, which is representative of systems using small charged particles, the design of the charge characteristics of the toner particles is required for miniaturization and high image quality. Toner particles, which are derived from insulating polymers, are charged by contact with metals or other charged toner particles during operation of the system. The surfaces of the model polymer particles used in the simulation were divided into many small regions, as we can assume that the particles have numerous charging sites on their surfaces. While a given polymer particle is flowing, each of its charging sites is charged by contact with metals or the charging site of another particle. The amount of charge on a polymer particle can be represented by the summation of charge at all surface sites. The measurement system for the contact charge on polymer particles under precisely controlled contact conditions was developed to measure the metal-polymer or polymer-polymer charge transfer in the model. Small amounts of metal-polymer and polymer-polymer charge transfer were measured precisely. The charging experiment was carried out using flowing spherical particles of polystyrene in a vibrating box. The charging behavior of these particles was simulated using the discrete element method (DEM) and the application of model charging particles. The simulated charge distribution of the particles agreed well with those determined experimentally, meaning that the proposed simulation method will be useful in designing the charging characteristics of toner particles.