An Experimental Investigation of Flame-Spreading Mechanisms Over Textile Materials

Abstract

Qualitative observations of flame spreading over textiles indicate different governing mechanisms for cellulosic fabrics, for nylon fabrics, and for fuzzy cellulosic materials. For cellulosic fabrics, the important processes involve heat transfer from flame to virgin material and generation of combustible vapors to fuel the flame. The fine structure (i.e. the porosity and the interlacing geometry) of the cellulosic fabrics does not seem to affect the flame-spreading speed. Rather, the flame-spreading speeds are related primarily to fabric mass per unit area, as predicted by de Ris's solid-fuel flame-spread theory or by a simple energy balance at the solid-gas interface of the burning material. For nylon fabrics, the physics of the flame-spreading process are greatly affected by their thermoplastic behavior, i.e. by shrinking, melting and dripping; and for fuzzy cellulosic materials, by the occurrence of fire jumps, smoldering and gravity-induced flame blow-outs. Further experimental and theoretical work is needed on these two materials.