ABSTRACT The method of Fused Deposition Modelling (MDF) for polymers processing - usually called 3D printing - is one of the additive construction technologies with greatest impact in recent years. The irruption of low cost machines and the continuous improvement in quality and resistance of employed polymers, demand to estimate the life time and performance of printed parts. Hence, this work analyses the mechanical performance under bending efforts of polymers, typically used in additive construction. In particular, the bending elastic modulus is evaluated - through experiments designed "ad-hoc" - in Poly Lactic Acid (PLA), Nylon, and High Impact Polystyrene (HIPS) probes, as a function of tracing direction, orientation of printed parts, presence of dye additives in polymers, and printing speed. We found that all the studied variability factors significantly modify the bending elastic modulus. Analysis of filaments orientation in the three materials reveals that the MDF technique produces anisotropic pieces. The highest elastic modulus is achieved when all filament directions match the direction of main stresses. Besides, the dye additives have significant influence as well as the orientation of the printed parts. Besides, we verified that the elastic modulus decreases with increasing printing speed.

ABSTRACT The method of Fused Deposition Modelling (MDF) for polymers processing - usually called 3D printing - is one of the additive construction technologies with greatest impact in recent years. The irruption of low cost machines and the continuous improvement in quality and resistance of employed polymers, demand to estimate the life time and performance of printed parts. Hence, this work analyses the mechanical performance under bending efforts of polymers, typically used in additive construction. In particular, the bending elastic modulus is evaluated - through experiments designed "ad-hoc" - in Poly Lactic Acid (PLA), Nylon, and High Impact Polystyrene (HIPS) probes, as a function of tracing direction, orientation of printed parts, presence of dye additives in polymers, and printing speed. We found that all the studied variability factors significantly modify the bending elastic modulus. Analysis of filaments orientation in the three materials reveals that the MDF technique produces anisotropic pieces. The highest elastic modulus is achieved when all filament directions match the direction of main stresses. Besides, the dye additives have significant influence as well as the orientation of the printed parts. Besides, we verified that the elastic modulus decreases with increasing printing speed.