Roundness Error Evaluation in Drilling of Glass Fiber Reinforced Polypropylene (GFR/PP) Composites Using Box Behnken Design (BBD)

In this paper, the damage of drilling parameters on roundness error is investigated in drilling of Glass Fiber Reinforced Polypropylene (GFR/PP) matrix composites with ‘Brad and Spur’ drill bit. The experiment is carried out using Solid Carbide drill bit and L27 orthogonal array is used to analyze the effect of spindle speed, feed rate and drill diameter. A complete and in-detail evaluation and optimization of cutting parameter using Box-Behnken Design (BBD) technique is carried out. The design is contributed for quality and productivity equally and analysis of the drilling parameters. The roundness error is determined using response surface methodology (RSM) and Analysis of variance (ANOVA) which is used for analyzing the output results. One of the most important ovalty damage to be controlled on a cylindrical drilled part is the roundness error. The Co-ordinate Measuring Machine (CMM) is the general metrological equipment used for inspection of roundness error which is normally performed in a quality room. The results indicated that the model can be effectively used for predicting the response variable by means of which roundness error can be controlled. 3-D response surface graphs are developed to study the effect of drilling parameters with roundness error and presented in detail.