- Author
- Ohlemiller, T. J. | Rogers, F. E.
- Title
- Smoldering Combustion Hazards of Thermal Insulation Materials.
- Coporate
- Princeton Univ., NJ
- Report
- THESIS, October 15, 1979, 128 p.
- Keywords
- smoldering combustion | thermal insulation | oxidation | thermal analysis | kinetics | ignition temperature | heat sources | degradation | thermochemistry
- Identifiers
- thermal analytical results on cellulosic insulation; effects on smolder ignitability; attic mock-up showing various heat source positions; smolder ignition test results for a single commercial cellulosic insulation; borderline (minimum) ignition temperatures for a commercial cellulosic insulation in various configurations
- Abstract
- The present report extends the work in the attached Appendices on smolder ignitability in cellulosic insulation and on thermal analytical characterization of the oxidation of this material. Thermal analysis (TGA and DSC) shows that both retarded and unretarded cellulosic insulation oxidizes in two overall stages, both of which are exothermic. The second stage (oxidation of the char left as a residue of the first stage) is much more energetic on a unit mass basis than the first. However, kinetics and a sufficient exothermicity make the first stage responsible for ignition in most realistic circumstances. Existing smolder retardants such as boric acid have their major effect on the kinetics of the second-oxidation stage and thus produce only a rather small (20 deg C) increase in smolder ignition temperature. Several simplified analogs of attic insulations have been tested to determine the variability of minimum smolder ignition temperature. These employed planar or tubular constant temperature heat sources in a thermal environment quite similar to a realistic attic application. Go/no-go tests provided the borderline (minimum) ignition temperature for each configuration. The wide range (15O deg C) of minimum ignition temperatures confirmed the predominant dependence of smolder ignition on heat flow geometry. Other factors (bulk density, retardants) produced much less effect on ignitability.