Effects of Recycled ABS Content on Extrusion Stability, Diameter Variability, and Mechanical Response of Filaments for FFF/FDM Printing

This study addresses the production of 3D printing filament by extrusion from acrylonitrile butadiene styrene blends containing virgin and recycled material. The effect of recycled acrylonitrile butadiene styrene content on selected quality indicators was investigated, with particular emphasis on mechanical response and filament diameter stability. Dimensional stability was considered a critical quality parameter, as diameter fluctuations directly affect material flow consistency during subsequent FFF/FDM processing and may contribute to extrusion-related defects. The fracture surface morphology of the tested filaments was evaluated by optical microscopy. Based on experimental measurements and data analysis, recommendations are proposed to improve the stability of the filament extrusion process when processing ABS blends containing recycled material.