Transforming automotive polypropylene components into 3D printing filaments

Abstract The automotive sector plays a fundamental role in the search for solutions for the reuse, remanufacturing and recycling of materials, parts and components of vehicles produced to mitigate their environmental impacts. The automotive sector has requested to mitigate its environmental impacts through the reuse, remanufacturing, and recycling of materials, parts, and components of the vehicles produced. This work presents a proposal to reuse discarded automotive parts made of talc‐reinforced polypropylene (20 and 40% w/w) to produce filaments used for 3D printing. To produce the filament, firstly discarded parts were cleaned, washed, and dried. Afterward, they were ground and extruded through a machine, then used to print test samples using a fused deposition modeling (FDM) 3D printer. Filaments were characterized using scanning electron microscopy (SEM), thermogravimetry (TGA), differential scanning calorimetry (DSC), and Melt flow index techniques. Results showed that adding talc did not significantly influence the filament's diameter, density, extrusion temperature, and roughness. Also, talc enhanced the compatibility, increasing the interaction between the composite components. This led to a reduction in the melt flow index, as the chain mobility was decreased. The developed composite filaments (20 and 40% w/w) were successfully 3D printed and the amount of talc reinforced in PP influenced the Shore D hardness values. Thus, the possibility of including plastic parts produced by FDM technology is an innovative option for car manufacturers, representing an opportunity to empower small‐scale producers of polymers. Highlights 3D printing provides agile prototyping and expands design possibilities. Reuse of automotive parts to produce filaments for 3D printing. Filaments of talc‐reinforced polypropylene (20% and 40% w/w). Filament characterization through SEM, TGA, DSC, and MFI techniques. The composite filaments (20 and 40% w/w) were successfully 3D printed.