Application of chemometrics to the production of friction materials: Analysis of previous data and search of new formulations

Abstract A friction material is a composite containing up to 18 different components which can be chosen among a large number of possible raw materials having different characteristics, like graphite, sulphides, metals, fibers, rubbers, resins and fillers. The requested form is obtained by moulding at controlled pressure and temperature. In order to prepare new formulations having good performances, the problem is to choose the best raw materials and to mix them in the optimal proportions. Since the quality of a formulation is not expressed by a single value, but several responses have to be taken into account at the same time (friction coefficient, comfort, wear, etc.), the analysis of the data obtained from different formulations is quite difficult. In this study an approach to the analysis of this kind of data is presented, in order to evaluate different products on the basis of a small number of ‘quality indicators’. The techniques of experimental design are successfully applied in order to investigate the effect of process variables on the performances of the product and to perform a screening of the raw materials for new optimal formulations.