Application of response surface methodology for weld strength prediction in laser welding of polypropylene/clay nanocomposite

Welding as a fabrication process can be used to join materials, including composite and nanocomposites and laser welding process due to its advantages has found wide applications in this field. Its process parameters can play a significant role in determining the weld strength of laser-welded joints in polypropylene/clay nanocomposites. In this study, the effect of laser welding parameters, such as laser power, welding speed and focal position along with the clay content in a polypropylene/clay nanocomposite on weld strength were determined using response surface methodology. This methodology was applied for developing a mathematical model which can predict the main effects of the above parameters and their impacts on tensile strength of butt-welded laser joints in 2-mm thick polypropylene/clay nanocomposite sheets. The analysis of variance was performed to check the adequacy of the developed model. A comparison was also made between the predicted and actual results. The results showed that weld strength decreased when clay content was increased from 0 to 6 %, but welding speed increased from 30 to 60 mm/s. The above parameters were also optimized to achieve a high strength welded joint.