In large-scale fires, the input of energy to burning materials occurs predominantly by radiative transfer. The in-depth absorption of radiant energy by a polymer influences its ignition time and burning rate. The present investigation examines two methods for obtaining the absorption coefficient of polymers for infrared radiation from high-temperature sources: a broadband method and a spectral method. Data on the total average broadband transmittance and absorptance for eleven thermoplastics are presented (as are reflectance data), and the absorptance is found to vary with thickness. Implications for modeling of mass loss experiments are discussed.
Citation: Fire and Materials
Pub Type: Journals
pyrolysis modeling, material flammability, IR absorption, polymer diathermicity