Design optimisation of aluminium recycling processes using Taguchi technique

In this paper, a robust design method is developed for reducing cost and improving quality in aluminium recycling. An experimental investigation into the process parameter effects is presented to determine the optimum configuration of design parameters for performance, quality and cost. The Taguchi method is applied initially to plan a minimum number of experiments. Orthogonal array techniques are used to investigate the simultaneous variation of several parameters and the investigation of interactions between parameters. Matrix experiments using standard L4 and L9 orthogonal arrays are employed to evaluate the effects of parameters in recycling of aluminium dross and scrap materials. A statistical analysis of signal-to-noise ratio is followed by performing an analysis of variance (ANOVA), in order to estimate the optimum levels and determine the relative magnitude of the effect of various factors. Finally, a historical data analysis based on the response surface methodology is carried out using a Taguchi orthogonal analysis. Experimental results are shown for an L18 orthogonal array illustrating a good agreement between the optimum factor levels suggested by the signal-to-noise ratios and those obtained from the response surfaces.