Experimental Analysis and Optimization of Process Parameters of Plastic Injection Moulding for the Material Polypropylene

In present work, experimental analysis and optimization of process parameters of plastic injection moulding has been reported. Response surface methodology (RSM) has been utilized to investigate the influence of three important input parameters – plasticizing temperature, injection pressure and cooling time on two performance characteristics- Tensile Strength of material Polypropylene (PP). Centered central composite design was employed to conduct the experiments and to develop a correlation between the process parameters and performance characteristics. The analysis of experimental work is performed using MINITAB 16 statistical software. Response surface methodology (RSM) was applied for developing the mathematical models in the form of regression equation and to find optimized values of process parameters. The optimum set of process parameters obtained are cross validated by using ANOVA method. The influence of all factors has been identified which can play a key role in increasing Tensile Strength of PP. Surface plots and Contour plots have been plotted for studying combined effect of two factors while keeping other factor at their mid-values. From ANOVA it is clear that for Polypropylene to achieve maximum Tensile Strength injection pressure is the most significant factor followed by cooling time and plasticizing temperature followed by injection pressure and cooling time.