The effect of printing parameters on hardness in the production of Poli lactic acid (PLA)-based samples with a 3D printer

Abstract

The fused Deposited Modelling (FDM) technique, one of the additive manufacturing methods, has attracted much attention recently due to its high design flexibility and ability to create complex parts. While a wide variety of parts can be easily manufactured using 3D printers layer by layer according to traditional methods, the printing parameters significantly affect the mechanical properties of the products. This study aims to investigate the effect of printing parameters on the part's hardness. Nozzle diameter, layer height, raster angle, and nozzle temperature were chosen as the printing parameters to be investigated. Three levels were determined for each parameter, and the required high number of experiments was reduced by applying the Taguchi experimental design method. Polylactic acid (PLA) based samples were manufactured and tested according to ASTM standards. Hardness measurements were taken from 5 points on each sample using the Rockwell L method. The highest hardness value was measured as 45 HRL. Although the contribution of nozzle diameter to hardness is 85%, the effect of nozzle temperature is very low and uncertain. The hardness of the manufactured part is directly proportional to the layer thickness and inverse nozzle diameter. Productions made with high -diameter nozzles give better mechanical results and reduce production time. With the increase in the performance of 3D printers and the decrease in costs, the preference rate in manufacturing end -user products is increasing. This study will help to calculate the printing parameters with less uncertainty and variability in determining the surface hardness of the samples.