MIXTURE EXPERIMENT APPROACHES - EXAMPLES, DISCUSSION, AND RECOMMENDATIONS

A mixture experiment involves varying the proportions of two or more i ngredients, called components of the mixture, and studying the changes that occur in the measured properties (responses) of the resulting en d products. Other factors that affect the response(s) such as process variables or the total amount of the mixture may also be studied in th e experiment. Five approaches for designing mixture experiments and an alyzing the data are considered: component proportion, mixture-amount, mixture-process variable, mathematically independent variables, and s lack variable. The approaches are illustrated using examples from the literature. The various approaches are discussed and recommendations a re made for choosing among the approaches when faced with a mixture ex periment problem. A five-component waste grout example for which sever al mixture experiment approaches are possible is discussed.