Influence of Printing Parameters on Impact and Tension Resistance of Parts Produced by the Fused Filament Fabrication Process

Additive manufacturing by the Fused Filament Fabrication (FFF) process is a manufacturing process that has great potential for facilitating the production of complex and customized parts quickly, with low production costs and little material waste. However, the mechanical resistance of the parts produced by this manufacturing method vary greatly according to printing parameters, especially when they are not bulk solid. It was observed in this work how the impact and tensile resistance of a part change according to the thickness of the shell, height of the printed layer and the infill since these factors alter the moment of inertia and thermal loads. For instance, it is hard to predict if the mechanical properties will improve when increasing shell thickness and reducing infill, or vice versa. Specimens were then produced following a complete factorial design for these 3 variables at 2 levels, and then an analysis of variance was performed with the data from tensile strength tests according to ASTM D638 and impact resistance according to ASTM D4508. Shell thickness was shown to be the most influential and advantageous.