Basic Polymer Material Properties for Flame Spread

Abstract

We present and demonstrate the application of a systematic methodology for predicting fire spread and growth and for a relative fire hazard classification of materials for any scale and fire environment. This methodol ogy consists of three steps: (1) select laboratory test methods to perform flam mability measurements; (2) based on these measurements, obtain key flamma bility material properties which are precisely defined in this work; and (3) use these properties in a mathematical model of fire spread and growth to predict fire hazards. The complementary test methods we have selected and used are: (a) a general flammability test apparatus (such as NIST or FMRC) [1,2] modified to also provide pyrolysis measurements in an inert N2 atmosphere; (b) the Limited Oxygen Index (LOI) apparatus, which is used here as a tool for ob taining properties needed for creeping flame spread and extinction, including vitiated environments; and (c) a solid material smoke-point height apparatus [8], which is used to characterize the smokiness of the burning material needed to determine the radiation and smoke yield for arbitrary fire situations (wall fires, pool fires or ceiling fires) [8]. The use and proper interpretation of the Limited Oxygen Index apparatus can replace the LIFT [10] apparatus for deter mining in a more accurate and direct way the material properties required for creeping (vertical downward, lateral, horizontal) flame spread. The present methodology has been compared well with experiments in this work and else where [9], and it has been used to predict critical conditions for fire spread [11], not empirically as it is usually done, but based on first principles of fire spread, fire growth and burning, together with material flammability properties syste matically deduced from small-scale test measurements.