Experimental and statistical study on kerf taper angle during CO2 laser cutting of thermoplastic material

Abstract

CO2 laser machining is an advanced material processing technology, gaining more popularity due to its low cost and rapidity as well as good cutting quality depending on the material and its properties. Polymethylmethacrylate (PMMA) is found to be one of the most suitable thermoplastics for CO2 laser machining due to its higher melting point and higher absorptivity at the CO2 laser wavelength. The kerf taper angle is one of the most important quality characteristics because it is one of the measures for the geometrical accuracy of the machined cavities. The present work deals with the CO2 laser (0–25 W) cutting of 8 mm thick PMMA material. The influence of process parameters like power, speed, and a number of passes of the laser probe is examined on the kerf taper angle. The regression analysis has been done to develop a model that studies the effect of process parameters on the kerf taper angle which is one of the important cutting quality characteristics. Experiments were carried out using the full factorial methodology, and the cylindrical blind cavities were machined for different combinations of parameters. It is found that power, speed, and a number of passes have a significant effect on the kerf taper angle. Higher laser power, lower speed, and higher number of passes of laser probe result in low kerf taper. The statistical model developed can be used for the selection of process parameters for process control.