Protective Clothing Fabrics

Abstract

An increase in the fabric- or assembly-heat sensor separation improved protection against convective heat (flames) exposure. Zirpro wool assemblies required a longer exposure time to reach second-degree burns, with a longer pain-alarm time than comparable assemblies of aramid or flame-retardant cotton. An increase in the weight of Zirpro wool fabrics decreased heat transfer, but an assembly of a Zirpro wool woven outerwear and a Zirpro wool knitted underwear fabric transferred significantly less heat than a single layer of a Zirpro wool woven fabric of comparable weight with the assembly, because of entrapped air in the thicker innerwear fabric. With decreasing imposed heat flux, time for second-degree burns and pain-alarm time was increased, especially in the case of Zirpro wool.