Design Of 3D Printing Platform For Continuous Fiber Reinforced Thermoplastic Composites

Carbon fiber composites are becoming an important resource in the field of new materials due to their high specific strength,stiffness,heat resistance and corrosion resistance.However,the conventional molding process is more complex,high-cost and high-pollution.In this industry background,some new composite material forming processes begin to get attention,among which the composite 3D printing technology is a kind of rapid prototyping process to realize the additive manufacturing of composite materials.In foreign countries,the carbon fiber3 D printer has been commercialized,but there is no mature product in China yet.Therefore,it is of great significance to develop a mature product independently.This paper compares the key parameters and nozzle structure by studying the traditional FDM 3D printing process and the existing 3D printing process of composite materials.The paper analyzes the problems of plugging and filament breaking that may encounter in the 3D printing process,and optimizes the structure of nozzle.On this basis,built the 3D printing experiment platform for carbon fiber prepreg reinforced composite.Firstly,the paper compares several 3D printer structures based on FDM technology,selects XYZ structure as the main frame,and designs the motion mechanism of xyz axis respectively.According to the characteristics of carbon fiber prepreg,designed the nozzle which can print both resin material and carbon fiber prepreg filament respectively.The influence of the fillet inside the nozzle on the filament breaking is verified by finite element simulation and processed according to the simulation results.According to the structure of nozzle,a detachable continuous carbon fiber filament cutting mechanism is designed.Secondly,on the 3D printing experimental platform,developeing the control system of 3D printing experiment platform,which is divided into hardware and software.The hardware includes controller,limit switch,servo driver,heating rod,hot bed,etc.The software includes the development of HMI based on the component of the solid OpenCNC platform,the programming of 3D printing assistant modules such as communication module,temperature measurement module,heating module and filament cutting module.Finally,calibrating and debugging the all parts of the 3D printing experiment platform,including the calibration of motion accuracy,the adjustment of filament cutting mechanism and the debugging of temperature control module.After the calibrating of each part,the printing test and the tensile test of the printed parts are carried out.Finally,design the ultrasonic vibration assisted 3D printing molding experiment to explore the influence of ultrasonic vibration on the interface binding of composite materials.