A Study of Optimum Conditions for the Production of a Prototype of Nakhon Si Thammarat’s Niello with 3D Printing

This study employed a Box–Behnken Design for experimental planning and analyzed the results using Response Surface Methodology (RSM). The process parameters considered were print temperature, print speed, and infill density. Experimental results revealed that the optimal printing conditions for achieving the highest tensile strength, as determined by RSM, were a print temperature of 240 °C a print speed of 30 mm/s, and an infill density of 80%. Under these conditions, the printed specimens exhibited 36.16 MPa as the maximum tensile strength and 4.96 µm as the minimum surface roughness. The anticipated values were compared with the actual experimental data to verify the accuracy of the experimental model and response predictions. The results showed strong agreement between the predicted and experimental values, with average prediction errors of only 1.11 for tensile strength and 0.93 for surface roughness, confirming the reliability of the developed model.