FDM 3D printing of MWCNT re-inforced ABS nano-composite parts with enhanced mechanical and electrical properties

This work presents significant mechanical and electrical property enhancement of 3D printed parts through dispersion of multiwall carbon nanotubes (MWCNTs) using twin-screw micro-compounding extruder having a backflow channel facility. The composite structure obtained has been further processed in a single screw extruder to produce 3D printing filaments, 1,7 mm in diameter. The mechanical, electrical and melt flow properties of the MWCNT reinforced ABS matrix composite parts, with loading percentages up to 10% has been presented for the first time in this work, using a commercial 3D printer. Moreover effects of raster angle on tensile properties such as tensile strength, ductility and the elastic modulus as well as the electrical conductivity are also studied. The tensile strength of 3D printed parts has increased considerably (up to 58 MPa equaivalent to 288% increase) with 7 wt.% addition of MWCNTs in ABS. However ductile to brittle transition was observed with increasing MWCNT concentraion. Micro Raman spectroscopic and scanning electron microscopic analysis made on the 3D-printed MWCNT parts supports the enhanced mechanical properties. Electrical conductivity of the composites has also shown dramatic increase ( similar to 7 fold increase), owing to the existence of MWCNT particles. A 3 wt.% MWCNT loading percolation threshold found for the linear printing direction shifted to 5 wt.% for the crossed layered samples.