Printing Characteristics of TPU/MWCNT Conductive Composite Using FFF

Conductive polymer composites (CPC) have been remarkably developed, demonstrating their potential in various applications such as sensors, wearables, and even the field of biomedical. Furthermore, the recently attracted multi-material additive manufacturing (MMAM) technology indicates the potential for expansion into a wider range of applications. However, the characteristics studies of printable composites are still in progress, and this implies that the applicability of composite materials is limited in the near future. It is also necessary to consider an investigation of conductive composites with unexplored wide ranges of filler contents. CPCs are easier to print when the conductivity filler content is low. On the contrary, increasing the conductivity filler content to enhance electrical conductivity leads to a decrease in polymer characteristics, making it challenging to print. In this study, TPU (thermoplastic polyurethane)/MWCNT(multi wall carbon nanotube) filaments incorporating relatively high content MWCNT were manufactured. The filaments were extruded by the melting mixing method and the printing characteristics were discussed using fused filament fabrication (FFF). It was confirmed that TPU/MWCNT filaments with a maximum MWCNT content of 20% could be produced, but printing was limited to 15% MWCNT content. As the MWCNT content increases, the nozzle temperature also needs to be increased to avoid print quality reduction. Additionally, the electrical and mechanical properties of the printed TPU/MWCNT composites were investigated.