LAUSR

With the increasing use of 3D printers especially the fused filament fabrication type in the industries and general public, there is indeed a need to consider the after-use treatment for the products. The use of recycled filaments as the feedstock for 3D printers is a feasible alternative, but its application is limited to rather poor product quality. This study, thus, evaluates the effects of adding iron (Fe), silicon (Si), chromium (Cr), and aluminum (Al) nano-crystalline powders into the recycled polypropylene/high-density polyethylene plastics feedstock for filament extrusion. Physical and mechanical analysis tests revealed that the addition of 1% Fe–Si–Cr or Fe–Si–Al resulted in better thermal stability, and up to 37% and 17% improvement, respectively, in yield strength and Young modulus compared with the original recycled filaments, possibly due to the enhancement of interfacial adhesion between the nano-metal powders and the polymer, leading to reduced crack formation.