Design and Implementation of 3D Printing System for Continuous CFRP Composites

Jiangsu Key Laboratory of 3D Printing Equipment and Manufacturing, Nanjing Normal University, Nanjing 210042, China

Abstract

The rapid and low-cost manufacturing of continuous Carbon Fiber Reinforced Polymer (CFRP) composites using 3D printing technology is a hot topic in the field of composite materials’ research. Due to the continuity and infusibility of the long carbon fiber, a series of problems such as loosening of fiber, breakage, and nozzle clogging occurred in the printing process, which result in poor surface quality and performance in the printed product. This paper aims to solve these problems based on the researches and optimizations of three-dimensional printing technology for continuous CFRP composite components. Firstly, the coupling mechanism of continuous fiber and resin polymer in the flow path of nozzle is analyzed, the finite element simulation models of flow field and temperature field of CFRP three-dimensional printing are established by using ANSYS CFX software, and the coupling characteristics and interface performance in the printing process are studied. Then, based on the results of simulation analysis, a modification method of the surface coating film is applied, and a special modification solution is configured to modify the surface of the carbon fiber so as to increase its strength and bondability with the molten resin. Finally, the mechanical structure of the three-dimensional printing system of continuous CFRP components is designed to achieve the synchronization of printing and fiber modification. Considering the continuity of continuous carbon fiber, this paper proposed a new method of printing path design called “unicursal” for continuous CFRP parts, that is, when designing and planning a three-dimensional print path, it ensured that there is no interruption in the printing process, so as to achieve carbon fiber continuity in composite parts. The reliability and superiority of the printing system designed in this paper are confirmed by printing of the composite parts.