Mechanical characterization of polylactic acid, polycaprolactone and Lay-Fomm 40 parts manufactured by fused deposition modeling, as a function of the printing parameters

Abstract

This study aims to determine the mechanical properties of parts manufactured by Fused Deposition Modeling (FDM) using three biocompatible polymer materials: Polylactic Acid (PLA), Polycaprolactone (PCL) and Lay-Fomm 40. Also, it was analyzed the influence of different printing parameters, material selection, infill percentage, and raster angle, over the mechanical properties. The samples were subjected to tension and compression tests using a universal testing machine, and elastic modulus, yield stress, and ultimate stress were obtained from the stress-strain curves. PLA samples have the highest elastic modulus, yield stress and ultimate stress for both compression and tension tests, for example, the ultimate tensile stress with infill percentage of 30 % and raster angle of 0-90° has an average value of 41.20 MPa, while PCL samples had an ultimate tensile stress average value of 9.68 MPa. On the other hand, Lay-Fomm40 samples had the highest elongations, with percentage values between 300 and 600 %. Finally, ANOVA analysis showed that the choice of the material is the leading printing parameter that contributes to the mechanical properties, with percentages of 84.20% to elastic modulus, 93.30% to yield stress, and 82.44% to ultimate stress. The second important factor is the raster angle, with higher strengths for the 0-90° when compared to 45-135°. On the other hand, the contribution of the infill percentage to the mechanical properties was no statistically significant. The obtained results could be useful for material selection and 3D printing parameters definition for additive manufacturing of scaffolds, implants, and other structures for biomedical and tissue engineering applications.