Dynamic analysis of a recirculation system of micro functional fluids for ink-jet applications

Abstract

The rise of ink-jet printing technology has led to numerous studies about functional fluids, which, in most cases, are made to change and improve the chemical and rheological properties. Besides this, there are several patents about the recirculation fluid system that help to prevent settling particles, and thus improving print quality without consequences in the chemical composition of the fluid. This paper presents a dynamic analysis of a recirculation circuit for ink-jet microsystems applications with fluids that contain a particle size of 40 nm to 10 µ m. This analysis integrates multiple mathematical and experimental models, in regard to variables such as: viscosity change with temperature and solid volume fraction, sedimentation, surface tension and flow behavior. As a result, specific values of vacuum pressure for different drop-on-demand print heads with different ink-jet functional fluids, places of probable sedimentation and minimum pickup velocities to remove settled particles are given. © 2017, Springer-Verlag Berlin Heidelberg.