Structure Design And Numerical Simulation Of Screw Extrusion 3D Printer

3D printing is a rapid prototyping technology that is often used to additive manufacturing.Melt deposition techniqueis a kind of 3D printing of typical 3D printing technology which has many advantages,for example,simple structure,favorable price,safe and reliable operation and so on.However,its further promotion and application are affected by the limited types of consumables,easy clogging of nozzles,and products.The accuracy of printed parts is difficult to be controlled.Therefore,It's time to solve the existing problems in the FDM 3D printing,this research designs a new type of twin-screw extrusion 3D printing molding equipment,carries out the theoretical design and numerical simulation research of the molding extrusion system,and It is used to improve the performance of existing 3D printers.First,design a new type of 3D printing molding system's overall layout and control transmission scheme for the moving parts,and through the reasonable decomposition of each execution moving part,and a kind of FDM twin-screw granular 3D printer is designed.Comprehensive consideration of the structural parameters of the screw and the relationship between the rotation speed and the nozzle extrusion volume,etc.,determine the best matching model of the screw rotation speed and the nozzle feed speed.Then,numerical simulation software ANSYS Workbench was sued to analyse the sterss and deformation of the twin screw under the actual case,meanwhile compulate the stress,justfy the shrength and stiffiness whether reachthe accury of design.Then,the numerical simulation software POLYFLOW was used to analyze the real conditions in the flow field by a variety of indexes and parameters.By discussing the screw work in diverse working conditions can we grasp the law of the hot melt inside in the runner during the extrusion process.Study the influence of structural design parameters and process parameters on the flow field distribution and printing accuracy of twin-screw extrusion molding,and obtain the optimized parameters of the screw.Finally,The temperature field and the thermal stress coupling field are used to simulate the temperature distribution of the hot fluid in the nozzle.The analysis of the influence of the nozzle geometry on the 3D printing molding accuracy can make the material extrusion more stable and continuous.