Design And Implementation Of Process Control System For 3D Printing Of Molten Mixed Materials

With the continuous development of modern society,traditional manufacturing has been unable to meet people's requirements for efficient and intelligent production.3D printing technology emerges at the historic moment,promoting the transformation of traditional manufacturing industry to intelligent advanced manufacturing industry.Also known as additive manufacturing,3D printing is a method of building up layers of material based on digital model files.3D printing technology has the advantages of saving manufacturing materials and being able to realize the forming of complex heterogeneous structures.It has been widely used in industrial design,mold manufacturing,biological medical treatment,aerospace and other fields.Fused Deposition Molding(FDM),as one of the more mature technologies in 3D printing,has the advantages of low printing cost and simple Molding equipment compared with other 3D printing technologies.However,at the present stage,most FDM devices can only print finished silk materials such as ABS and PLA,and do not have the ability of melting and mixing integrated printing of multi-component materials.In order to realize the fusion and mixing integration printing of complex threedimensional objects with heterogeneous structure,this dissertation proposes a dual nozzle3 D printing process for the fusion and mixing materials,and focuses on the design of a set of PLC based fusion and mixing materials 3D printing process control system.First of all,the melting and mixing 3D printing process is analyzed,and based on this,the overall scheme of the melting and mixing materials 3D printing control system is formulated,and the hardware and software design ideas of the control system are given,which lays the foundation for the hardware platform construction and control program writing of the control system.Then,on the basis of analyzing and counting the input and output points of the system,I select the hardware such as Programmable Logic Controller(PLC)and sensors,design the electrical circuit and electrical control cabinet of the system,and build the hardware platform of the control system with PLC as the core.Secondly,the system is divided into several modules according to the process flow,and the control flow and control program of each module are designed to realize the function of data acquisition and control in the process of system operation.Thirdly,in view of the printing material's sensitivity to temperature,as well as the system temperature instability and interference caused by the use of special heating methods,by establishing a mathematical model of temperature as the controlled object,the control effect of conventional PID and fuzzy PID is compared,the results show that the fuzzy PID has better control ability.Finally,the developed control system was integrated with the 3D printing device of molten mixed materials,and the experiment was carried out to print the heterogeneous cylindrical sample wrapped in the shell.The printing results show that the control system can control the whole printing process,and it can meet the needs of melting and mixing integration printing of high viscosity and multi-component materials.