Effect of layer height, print speed and cell geometry on mechanical properties of marble PLA based 3D printed parts

Material extrusion (MEx) related technologies are widely common and popular in the industry due to their ability to handle wide variety of polymeric materials, user friendly printing process, and lower initial and running cost. Fused deposition modelling (FDM) is a commonly used material extrusion based three-dimensional printing process. Marble - Polylactic acid (Marble - PLA) is a derivative of regular Polylactic acid (PLA), where fine marble powder is mixed with the matrix of PLA. Marble PLA combines the desirable properties of PLA with the aesthetic appeal of marble. The said material is getting popular in the applications related to the decorative ornaments, architectural model, art-based sculptures, and customized home décor etc. However, when it comes to the performance and mechanical characteristics there is not much information available in the literature. This paper applied Taguchi's design of experiment methodology and grey relational analysis to optimize the printing of Marble-PLA. The study varied three parameters of layer height (0.2 mm, 0.3 mm and 0.4 mm), print speed (30 mm/s, 40 mm/s and 50 mm/s) and cell geometry (triangular, diamond and hexagon). Tensile testing was performed on each sample after preparing them using ASTM D638 standard. The out responses were comprised of modulus of toughness, resilience, Young's modulus, yield strength, ultimate tensile strength and strain at fracture. The study revealed optimal conditions of layer height was kept 0.3 mm, print speed was 50 mm/s and triangular cell geometry. The grey relational analysis provided the improvement of 0.16747 in the grey relational grade.