Effect of layer thickness on flexural properties of PLA (PolyLactid Acid) by 3D printing

Abstract

This article focuses towards the newer manufacturing technique 3D Printing (3DP). The objective of this work is the mechanical characterization (flexurel properties) of materials produced by 3D printing based on fused filament fabrication with fused deposition modeling (FDM). The materials chosen are a polylactic acid (PLA). This paper described the effect of different layer thickness of PLA by 3D printing on flexural properties.Additive manufacturing, also known as 3D printing, is a common material extrusion process using (bio) polymers PLA. The study begins from manufacture the solid 3D model based on the ASTM standards for flexural properties test of the material using Three-point bending method. Three-point bending test was conducted with Tensilon Universal Testing Machine – AND RTF-2410 with a 100kN load cell, specimen shape and size according to standard size ASTM D 790. The result shown that the layer thickness had an effect on flexural strengths of PLA samples. The maximum flexural strengths from Lt = 0.4 to 0.5mm were significantly increase. Moreover, it is worth nothing that ductility decreased as layer thickness increased. According to test result that the maximum flexural strength occurred at 0.5 mm layer thickness with 59.6 MPa and the minimum flexural strength occurred at 0.1 mm layer thickness with 43.6 MPa. The higher layer thickness tended to promote higher strength. The thicker layer is the stronger layer bond in holding the load bending. In this study the thicker layer have tendend to shown a 90-degree delamination fracture and the thinner layer have tendend to shown a 45-degree delamination fracture according to the direction of printing is ± 45°.