Research On 3D Printing Technology Of Microdroplet Jetting Based On Wire

3D printing technology of microdroplet jetting is a new technology developed on the basis of digital printing.It takes the droplet as the basic forming unit and "accumulates" point by point and layer by layer according to the shape characteristics of parts to realize the rapid printing technology of three-dimensional structure.This technology has been widely used in the rapid manufacturing of micro-complex metal parts,micro-heterogeneous parts,microfunctional devices and micro-electronic devices in the field of aviation,aerospace and microelectronics.Because the microdroplet injection 3D printing technology has high requirements on the type of materials and the way of feeding,it is not popular in the 3D printing market in China.In order to reduce the threshold of microdroplet jetting 3D printing technology,a highprecision pneumatic firing pin type microdroplet jetting device is proposed in this topic to realize the 3D printing wire jet printing molding.Firstly,the structure design of the pneumatic firing pin type microdroplet jetting device was carried out according to the 3D printing principle of the microdroplet jetting.After the structural design of the pneumatic jetting component was determined,the scheme and structure design of the molten feeding component were determined through the simulation analysis of the temperature field.Then,starting from the knowledge of basic fluid mechanics,the theoretical analysis of microdroplet jetting was carried out.Aiming at the formation process of a single droplet,a mechanical model was established to analyze its force situation,and the critical conditions for fluid to achieve microdroplet injection were deduced.The fluid motion model at the nozzle hole was simplified,the jetting velocity and flow rate of the fluid at the nozzle hole were deduced,and their influencing parameters were determined,which pointed out the direction for the subsequent fluid simulation analysis.The Fluent module in ANSYS Workbench software was used to simulate and analyze the fluid state in the jetting chamber.Through the results of fluid simulation analysis,the influence law of the structure parameters and working parameters of the nozzle on the performance of microdroplet jetting was obtained.Finally,the production of pneumatic firing pin type microdroplet jetting device is completed and the experimental platform is built with this as the core.The functional modules of the experimental platform are introduced in detail.The experimental analysis of the spray performance of the microdroplet nozzle shows that the closed chamber formed between the nozzle firing pin ball and the nozzle cone has a direct effect on the spray performance.The minimum resolution of the microdroplet nozzle was obtained by the experiment of the minimum droplet jet printing.