Inconsistencies of Melt Flow Index (MFI) measurements in the failure analysis of polyethylene components

Characterizing polymeric materials involved in a failure analysis investigation via numerous analytical techniques and comparing these measured values with the stated manufacturer technical specifications is a common first step in such an investigation. Melt flow index (MFI) measurements are one of these techniques. MFI measurements provide both a quantitative measurement of the materials ability to flow as well as a qualitative parameter for correlation with a materials molecular weight. In the analysis of failed polyethylene components, many times the MFI is one of if not the only measured quantities found to not be in compliance with stated technical specifications. This talk will present case studies of such nonconforming materials used in various applications. Potential theories on this phenomenon's origin and its implications in failure analysis investigations will also be presented.