Preliminary Analysis of Extruded PP Filaments for FFF

Abstract The objective of the present work is the study of fabrication of Polypropylene (PP) filaments starting from raw and recycled materials, evaluating their use for Fused Filament Fabrication (FFF). The main operating parameters of the extrusion process are taking into account, identifying significant correlations between PP properties and process performances. After the material characterization, simulation tests were performed to evaluate material processability and related processing window. Numerical multiphysics models of filament extrusion and an FFF deposition were realized, allowing the evaluation of the processability to be performed. The filament extrusion was modeled as a pressure-driven flow spanning the entire nozzle diameter, also remaining fluid along the entire length. Using this model, a better understanding of the effect of extrusion runs on the thermal process was achieved, also identifying most influencing material properties.