- Author
- Ohlemiller, T. J. | Rogers, F. E.
- Title
- Survey of Several Factors Influencing Smoldering Combustion in Flexible and Rigid Polymer Foams.
- Coporate
- Princeton Univ., NJ
- Journal
- Journal of Fire and Flammability, Vol. 9, 489-509, October 1978
- Sponsor
- National Bureau of Standards, Washington, DC
- Keywords
- smoldering combustion | flexible foams | rigid foams
- Abstract
- Smoldering combustion of solid fuels can be divided on the basis of fuel permeability to air flow and further subdivided on the basis of relative "flows" of fuel and air through the smolder wave. The limiting case of 1-D, forward smolder for high permeability fuels has been examined here and in previous studies for both flexible polyurethanes and several rigid polymer foam materials. The oxygen-limited character of the smolder makes the process relatively insensitive to fuel chemistry variations, except during ignition. The behavior of flexible polyurethanes has further been shown to vary due to competition between tar and char formation during degradation; this competition is sensitive to chemical and physical factors that influence either degradation pathway. Low permeability smolder pertains to intact rigid polymer foams of the type used for thermal insulation. A series of tests, systematically changing heat loss and 0, supply conditions, is proposed for smolder tendency assessment in these materials. The resuIts from one of these, a facing slab test, show distinct differences which agree qualitatively with ease of oxidation of the polymer chars. All ignition temperatures are relatively high (350 deg C and above) but at least one rigid foam material, phenol-formaldehyde, is more ignitable in some conditions than white pine wood.