Recycling of HDPE from MSW waste to 3D printing filaments

This thesis investigates the suitability of Fortum CIRCO® HDPE for fused deposition modelling (FDM). Fortum CIRCO® HDPE is recycled high-density polyethylene sourced from municipal solid waste, provided by Fortum Waste Solutions Oy. The literature review covers rHDPE’s future in additive manufacturing. HDPE’s general ubiquity does not carry on into 3D printing. Challenges of warping and poor first layer adhesion in FDM are exaggerated with HDPE. The experiments are targeted towards exploring the feasibility of producing a high quality rHDPE filament suitable for FDM. Filament characterization techniques are used to compare rHDPE filament to a reference HDPE material. Also, printed parts are tensile tested to analyse mechanical properties of rHDPE and HDPE. This thesis illustrates that it is possible to produce rHDPE filament, although extrusion parameters have not been fully optimized. During the extrusion process a heated water bath was found to be crucial in producing the most round and the most regular filament. rHDPE filament has a more elliptical shape and greater diameter variation than pristine HDPE when produced with the available setup. Both recycled and pristine filament samples produced comparable print quality and similar Young’s Modulus values during tensile testing. In addition, the recycled material exhibited higher yield strength and greater ductility. rHDPE has potential as a feedstock material for FDM. Further research is required to improve the extrusion process