Evaluating the Performance of Thermally and UV Aged Firefighters’ Protective Clothing Using both Destructive and Non-Destructive Methods
Fulton, Mackenzie 1991-
Firefighters’ protective clothing (e.g. coat and pants) are multi-layer ensembles consisting of an outer shell, moisture barrier, and thermal liner. Strict material performance and manufacturing conditions exist for new firefighter protective clothing constructions, but evaluation of in-use or worn protective clothing lacks these defined metrics. A need currently exists for the development of a quantitative, material-property based method of determining the remaining useful life of firefighters’ protective clothing. A non-destructive testing method is desirable due to the high replacement cost of firefighters’ protective clothing. Additionally, a non-destructive testing procedure developed in laboratory conditions could be adapted for field use and allow for material performance history tracking by individual firefighters. Guidelines and specific performance indicators could then be developed for a detailed garment retirement procedure for future implementation in fire departments. This information would be extremely useful to many firefighting departments in Canada and around the world. This study considered destructive and non-destructive textile testing of aged outer shell materials of firefighters’ clothing. Three types of outer-shell Kevlar®/PBI fabric types were examined and mechanical strength was used to evaluate remaining fabric performance following thermal and UV ageing procedures. Thermal exposures were chosen based on data obtained from thermogravimetric testing and exposure conditions faced by firefighters. A scanning electron microscope was used to evaluate microstructural changes in the fabrics following thermal and UV ageing procedures. A fiber microstructure crack-development process based on ageing was outlined using this information. Near infrared (NIR) reflectance readings were obtained through the use of a spectrophotometer and related to the remaining material strength of the aged fabrics. Different methods of interpreting NIR spectral results were compared. These included reflectance shifts, absorbance feature characteristic changes (e.g. feature area and peak prominence/width), and slope change based on a normalized-difference index method. Absorbance feature area and characteristic changes showed promise at explaining thermochemical changes in the specimens following ageing. However, the normalized-difference index slope changes showed the best potential for characterizing the remaining tensile strength for all three fabrics.
DegreeMaster of Science (M.Sc.)
CommitteeTorvi, David; Noble, Scott; Odeshi, Akindele; Simonson, Cary; Meda, Venkatesh
Copyright DateAugust 2017
Firefighter protective clothing