Research On The Simulation Of Piezoelectric Inkjet Process Based On CFD

From the last century,the ink jet technology as an accurate digital control micron scale ink drop generation and distribution of technology and has performed well in the field of inkjet printing.And with the further development of inkjet technology,it also generated great application value in other fields,such as the microelectronics manufacturing,microelectronic packaging,micro optical components manufacturing and rapid prototyping etc.Meanwhile,the materials used also developed from water-based materials to more diversified direction,such as the lubricant,solder paste,photoresist and molten metal etc.Inkjet process involves forming and spreading of ink droplets which contains complex morphological changes of fluid.It is quite difficult to deal with this theoretical subject,so the study of droplet forming process can help to understand the droplet formation mechanism and provide guidance for the improvement of ink jet system which has important practical significance.In this paper,a push type piezoelectric inkjet system was developed and the evolution process of the forming of ink droplets was simulated after the overview of its development and application.First,the model of the push type piezoelectric ink jet system was established,and the dynamic process of ink drop was simulated by CFD software FLUENT.The phase diagram of the fluid was combined with the velocity and pressure cloud images to explain the mechanism of ink drop forming process.Second,the influence of the driving vibrator on the ink drop was studied.The single factor analysis of the amplitude and the hold time of the driving vibrator were done,and the case of the single variable influence on drop formation was obtained.Then,the parameters ranges of drop formation with satellite droplets,drop formation without satellite droplets and no drop forming were obtained by the analysis of the two sets of parameters.Finally,the effect of ink properties on the ink drop was studied.By using inks with different properties to do simulation analysis and calculation,with the effects of ink surface tension and the viscosity on the evolution of drop formation,the break up time of droplet and the length of the liquid column when droplet break up were obtained.