Experimental study on optimization of CO2 laser welding parameters for polypropylene-clay nanocomposite welds

Abstract

In this paper, polypropylene-clay nanocomposite sheets of 2 mm thickness with 0 wt%, 3 wt% and 5 wt% nanoclay are butt welded using a CO2 laser to determine the effect of clay content and laser process parameters on weld tensile strength. For this purpose, Taguchi parametric design and optimization method was used to design experiments and develop a model to predict weld tensile strength as a function of clay content and laser process parameters such as laser power, welding speed and focal position. The adequacy of the model was checked using analysis of variance and by conducting extra confirmation tests. Using Taguchi optimization approach, the optimum levels of parameters were determined. The results indicated that an increase in clay content and welding speed decreased the weld strength, whereas increasing laser power increased weld strength. Furthermore, increase in focal position showed an increasing and then a decreasing effect on weld strength.