Discrete element method simulation of developer flow behavior and toner developing in two-component system

Abstract

The magnetic brushes play an important role in a two component development system in order to realize high quality printing. Therefore, in the design of two-component development system, it is necessary to clarify the relationship between dynamic characteristics of magnetic brushes and design parameters. However, the empirical design and production by trial-and-error have been still cpplied to the real develtyjment procedure and they are time-consuming and expensive. A simulation tool of magnetic brush behavior and toner developing in a two-component electro-photographic system has been developed in this work. Most DEM (Discrete element method) simulation cpproaches have been restricted to a small area or volume, especially, the development zone between the magnet roller and the photoreceptor due to the limitation of number of particles for evaluation and extremely long calculation time. In this paper, a large scale-DEM simulation tool is proposed, which is able to analyze the magnetic brush behaviors in total region surrounding the magnet roller. Parallel computing with fast N-body algorithm has been tqrplied to the DEM calculation of enormous particles in the total region surrounding the magnetic roller. The DEM simulation has been performed in the main functional areas of the magnet roller, e.g. regulation, developing and separation areas and its validity is confirmed by comparison of experimental results. The effects of the geometry of blade, positions of the blade and the magnetic flux density distribution on the flow behavior of developer are investigated in regulation area. Also, the developing behavior of toner particles is simulated according to electric field conditions between magnetic roller and photoreceptor. In the experiment, DMA (Developer mass per area on magnet roller) and TMA (Toner mass per area) are evaluated for simulation accuracy. Simtdations are well matched with experimental results with lower than 10% error.