Understanding the influence of manufacturing and material parameters on the mechanical properties of polymer-clay composites : an exploratory statistical analysis

Abstract

Polymers are used in various industrial applications due to their ease of production, light weight and ductility. Adding fillers, such as clays, improves a range of thermo-mechanical properties, however manufacturing parameters may have an influence on the composite system. This paper provides a statistical analysis on a set of previously obtained experimental tensile data with various clay fillers added to high density polyethylene (HDPE). The composite material was compounded using an extrusion process and manufactured into tensile test samples by means of hot pressing. Various manufacturing parameters (number of extrusions, press time, sample cooling method), material (polymer grade, clay type, clay weight loading) and testing parameters (strain rate) were investigated to determine their influence on the mechanical properties, specifically strength (ultimate tensile strength) and ductility (percentage elongation at failure), of the composite system. The results showed wide variability, necessitating a statistical approach. The statistical analysis concluded that all parameters, except for press time, have a statistically significant influence on the mechanical properties of interest. The conclusions and insights gained from these analyses will be used to inform a statistical design of experiments to quantify the manufacturing variability and reliability in future work.