An Example of Application of a Mixture Design with Constraints to Screen a Large Number of Variables

• Activity Number: 298
• Type: Contributed
• Date/Time: Tuesday, August 5, 2014 : 8:30 AM to 10:20 AM
• Sponsor: Section on Physical and Engineering Sciences
• Author(s): Vaneeta Grover*+
• Companies: DuPont
• Keywords: Design of Experiments ; Mixture design ; Screening ; Formulation ; Constrained design ; Mixture with process variables

Abstract

In order to improve one of the existing offerings, initial scouting work identified about 20 raw materials that looked promising to meet the study objectives. Each raw material could be added only in certain proportion of one of the raw materials that was required to be present in the formulation. A constrained mixture Design of Experiment (DOE) with 17 mixture variables (raw materials/compounds) and 2 process variables was set up to study the effects of the raw materials on the 7 - 8 properties of the offering. The DOE consisted of 36 runs. A tool was created in Microsoft Excel using the results from the DOE that helped in looking at different scenarios depending on the importance ranking of the properties as well as the number of raw materials for which the property showed up as significant. We were able to identify the raw materials that resulted in the desirable properties and reduce the initial list of about 20 raw materials to 6 - 7.