Influence of additive manufacturing parameters by FFF on PLA tensile strength

When na object manufactured by 3D printing goes from prototype to a functional component, it is crucial to understand the mechanical properties of the material used. This knowledge determines the resistance limits of the object. Therefore, the objective of this research was to comparatively analyze the results obtained in tensile tests of specimens constructed with polylactic acid (PLA), printed in 3D, keeping the density constant and varying two construction parameters: the layer thickness and the geometry of the internal filling. The test specimens were made on a BFB Touch – Dual head-smoke 3D printer, in accordance with ASTM D638-14. Tensile tests were carried out using an EMIC model DL10000 testing machine, and the results were statistically analyzed for comparison. The results indicated that the maximum stress and fracture resistance increased with increasing thickness of the filament deposited by the extruder nozzle. Although PLA is often described in the literature as a brittle polymer, it has exhibited ductility characteristics when 3D printed, due to the alignment of fibers during the manufacturing process.