Preliminary investigations of polylactic acid (PLA) properties

Abstract

Additive Manufacturing (AM) is a technology capable to directly manufacture a prototype alongside with their inserted mathematical model in an additive nature. The emergence of 3D printing has secured a shorter cycle time for designing and developing innovative products. One of the most commonly used additive manufacturing technology is Fused Deposition Modelling (FDM). Its applications have included more load-bearing parts targeted to fit an intended application as per user’s requirement. A certain level of mechanical property information is being demanded as a benchmark to assess the strength of the printed part in the whole. This research work aims to investigate the tensile property of Polylactic Acid (PLA) and to determine optimum printing parameter combinations with the aim of acquiring maximum response using low-cost fused filament printer. Two parameters chosen to be varied in this research are raster angle and infill density, with the value of 20°, 40°, 60° and 20%, 50%, 80% respectively. Tensile specimens with a combination of these two parameters were printed according to ASTM D638 type 1 standard. Three mechanical properties were analysed, namely ultimate tensile strength, elastic modulus and yield strength. It was found that the tensile property increases with the infill density. Meanwhile, both high and low raster angle have shown the considerably high mechanical properties. The optimum parameters combination is 40° raster angle, and 80% infill density. Its optimum mechanical property is 32.938 MPa for ultimate tensile strength, 807.489 MPa for elastic modulus and 26.082 MPa for yield strength.