Experimental optimization: 3 Level full factorial design and variation of processing parameters for polycarbonate colors

The objective of this paper is to evaluate the influence of variation of processing parameters on the dispersion quality of polycarbonate compound. For proper dispersion of these pigments, the optimization of compounding process parameters is required. The effect of three processing parameters, temperature, screw speed, and feed rate, was investigated. Experimental design for the optimization of process parameter based upon 3 levels full factorial response surface methodology was utilized. Design expert software was employed to carry out the experimental designs, statistical and numerical optimization. Statistical equation developed by this method contained individual and interactions effects of parameters on the color values. The developed model and experimental data obtained passed all diagnostic tests establishing this model as statistically significant. The analysis of variance (ANOVA) reveals that the color parameters dL∗, da∗ and db∗ are significantly influenced by the three parameters studied. The best possible optimum process parameters were found to be: 245.26 oC, 741.27 rpm and 24.72 kg/hr in order to achieve the color values in a minimum desirable deviation dE∗ of 0.8. Application was extended to study the variations of the processing parameters while other parameters are constant (General Trends), focused on the minute variation of the feedrates leads to a significant improvement in key color desirable deviation dE∗ of 0.34. Both designs are yielded process parameters that were statistically significant.