The Critical Technology Of Drop-on-demand Jetting For 3D Printing

3D printing has been widely concerned and applied in field of m anufacturing equipment industry. However, drop-on-demand Jetting, which shows strong vitality in 3D printing, faces with some challenges: In the micro-jet, the existing resolution is not enough. This paper presents a type of jetting dispenser which is driven by piezoceramic material, high precision and wide range viscosity compatibility are proposed by this device.Considering the effect of 3D printing force on drop-on-demand jetting, this paper analyses the theory of drop-on-demand jetting, through contrast and compare four types of drop-on-demand jetting, the technology of mechanical needle is adopted. Dynamical model is built based on this type of drop-on-demand jetting, and in order to design the jetting dispenser, this paper deduces the necessary condition for drop-on-demand jetting.Based on the theoretical research in drop-on-demand jetting and combined with piezoelectric actuation theory, this paper completes the physical design for amplication mechanism 、 needle 、 nozzle and so on. A non-contact and drop-on-demand Jetting dispenser actuated by piezoelectric actuation is manufactured. It has laid a certain foundation for the flow modeling analysis in nozzle with Fluent.Governing equations are set up for a viscous and imcompressible laminar flow through thin orifice based on fluid dynamics after the physical design for the jetting dispenser. Changes of liquid surface in ambient air are tracking by means of Volume of Fluid method(VOF) which is a model in eulerian method. In this paper, simulation and analysis have been made on the procedures that needle movement down to pedestal with liquid flows through jetting nozzle and the formation of a droplet which provide a reference of optimization for the ph ysical design for the jetting dispenser and provide some related guidance in experiments concerning drop-on-demand jetting. Finally, according to the requirements of the dispensing process for 3D printing, a moving platform is set up, and some experiments related drop-on-demand jetting proceed based on it.