Entropy-TOPSIS appraisal of brake friction linings developed from composite agricultural wastes using optimum manufacturing process parameters

In this study, the optimum process parameters for the manufacture of brake friction linings (BFLs) from palm kernel shells (PKS), periwinkle shells (PWS), and coconut shell (CNS) composites were established using signal–to–noise ratio based on the Taguchi technique. The L9(34) orthogonal array was set up for the investigation of the performance metrics (coefficient of friction, wear rate, and hardness) synergized by multiple criteria evaluation. The manufacturing parameters considered were molding pressure, molding temperature, curing time, and heat treatment time. Consequently, the optimized parameters were utilized for the production of different BFL composites of the PKS/PWS/CNS mix. Finally, entropy and TOPSIS techniques were employed to isolate the best composite for comparative analysis. The results show that the optimum process parameters are 29 MPa (molding pressure), 120 °C (molding temperature), 6 min (curing time), and 2 h (heat treatment time). ANOVA using Minitab 21.1.0.0 shows that the effects of the molding pressure and curing time are statistically significant at α = 0.05, with a total contribution of 94.45%. The entropy-TOPSIS analysis gave sample S2pkpc with a composition of 12% PKS, 15% PWS, and 18% CNS as the best composite. Compared to the asbestos BFL, the composite shows an improvement in friction coefficient (45.7%), wear rate (66%), density (60.2%), and oil and water absorption (233%) (542.8%) respectively. The live test on a Peugeot 301 using S2pkpc BFL confirms the satisfactory performance of the composite. However, an increased wear rate was observed at vehicle speeds above 90 km/h.