A fundamental mathematical model of carpet is needed for studying the impact of component materials and thicknesses on tests that measure flammability. Of particular interest is the ASTM E648 radiant panel test, which is used to qualify floor coverings for commercial installations. The flammability characteristics of carpet in the cone calorimeter are expected to relate closely to carpet behavior in the ASTM E648 test. Accordingly, the combination of materials and their properties were sought that produces a match between cone calorimeter modeling and experiment. Careful measurements were taken from cone tests performed on broadloom style carpet composites for three types of fiber, on fiber plus primary backing alone, and on samples with adhesive plus one or both backings. Steps were taken to overcome the challenge of securing thin materials that curl and shrink during testing. This combination of tests enabled the determination of mass fraction, char yield, and heat of combustion for each individual component as well as capturing critical information such as time to ignition and effective heat of combustion for whole samples. These values can be used as input parameters for a cone calorimeter model to compare with experimental results. A simple transformation was found that collapses plots of heat release rate (HRR) for cone heat fluxes between 15 kW/m~2 and 35 kW/m~2 into a single curve for each carpet type. Broadloom style carpet is neither thermally thick nor thermally thin. As with many materials, however, both peak heat release rate (PHRR) and inverse time to ignition are linear functions of cone heat flux. The recognition that the inverse time to PHRR is also a linear function of cone heat flux results in the universal curve. This behavior may permit a more simplified approach to modeling more complex problems.
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