Multi-axis additive manufacturing process for continuous fibre reinforced composite parts

There has been considerable research in recent years on the additive manufacturing (AM) of continuous-fibre-reinforced thermoplastic composite parts (CFRTPs) based on fused-deposition modelling (FDM). Most current AM processes are achieved by sandwiching long fibres between the matrix material, which confines the specimens to a single fixed building direction and leads to inferior interfacial performance. Herein, we present a new strategy for printing CFRTPs in three-dimensional space using a novel self-designed multi-axis AM machine. Two head systems are introduced to deposit the thermoplastic and long fibres. Moreover, the multi-axis movement approach advantageously enables the fibre to be deposited on any programmed surface, or wound around the parts. Three types of wound material specimens are manufactured, tested, and compared with specimens produced by a traditional flat layer stacking process. The results show that the tensile and flexural strengths of the composites are significantly enhanced by the continuous fibre, and the interlaminar shear performance of the wound fibre parts were also improved. Additionally, the proposed process makes the manufacturing of complicated composites more convenient, and exhibits significant potential for practical applications.