A study on the strand arrangement in 3D printing of continuous carbon fiber composite materials with multiple strands

Abstract

3D printing of continuous carbon fiber composite materials with multiple strands has significant potential for improving model forming efficiency. However, in this field, we are faced with the challenge of arranging multiple fiber strands closely without excessive overlap consolidation, to avoid damage to the original model. The inability to effectively control the arrangement of multiple strands can significantly affect the print accuracy and mechanical performance of the model. Therefore, in this study, a predictive formula for the line width of carbon fiber strands is first presented. Subsequently, a device dedicated to 3D printing with multiple strands is designed using this formula, and the interrelationship between pressure and the arrangement of multiple strands is delved into. Comparative tests are also conducted on printed parts for tension and bending to investigate the influence of strand arrangement tightness on the mechanical performance of printed samples under different pressure conditions. Through electron microscopy experiments to analyze the microstructure of fracture surfaces, the causes of differences in mechanical performance and the potential effects of different pressures on print accuracy are explained. The results of the study indicate that when pressure can be precisely controlled to ensure a tight arrangement between multiple strands, the mechanical performance of printed parts reaches its optimal state. The tensile strength can reach 360.62 MPa, and the bending strength is 311.04 MPa. At the same time, for test samples printed under the optimal printing pressure, their surface accuracy is also at its best.