Protective Fabrics: A Comparison of Laboratory Methods for Evaluating Thermal Protective Performance in Convective/Radiant Exposures

Two laboratory methods used to evaluate the ability of fabrics to provide protective insulation against high intensity thermal exposures are compared. These procedures are ASTM D4108-82, a method that uses a single laboratory gas burner as the heat source, and a more versatile method that combines two gas burners and quartz heaters to provide a different mixture of radiant and convective heat. Comparisons are based on a series of tests made on a large group of specialized fabrics that might be used in the construction of protective apparel. Among the fabrics tested are samples made with flame resistant cotton, rayon, and wool, fabrics from glass and ceramic fibers, and fabrics from polyaramids, cross-linked phenolics, modacrylics, polybenzimidazole, and stabilized acrylic fibers. Differences in materials comparisons caused by the test procedure are discussed, especially the difference made by the balance of radiant to convective energy provided by the heat sources. Correlations are made with fiber and fabric properties. Special emphasis is placed on observing the performance of alu minized samples.