Flammability properties and radiant fraction of FRT wood plastic composites using mass loss calorimeter under HRR hood

Abstract

A special test arrangement was used to assess the flammability of 4 different wood plastic composites (WPC), most with fire retardants, all of which has a tendency to high smoke production leading to high radiant energy losses to the apparatus walls. The mass loss calorimeter (MLC) was modified to include a thermopile on the exhaust pipe stack to compensate for radiant energy losses to the wall (Figure 1) (Dietenberger, et. al.) A truncated conical electric heater provides a constant heat flux of up to 100 kW/m² onto the test specimen of up to 50 mm thick and a spark pilot igniter. Pure ethylene glycol and methanol for low flame radiant losses and the PMMA and solid polystyrene for high flame radiant losses supplanted the use of methane for calibrating the HRR using both thermopiles. Mass data was processed using a SG digital filter followed by an exponential filter so that the mass loss profile was synchronized the HRR in order to obtain an accurate effective heat of combustion (HOC) with time. Standard materials of methanol, ethylene glycol, PMMA and polystyrene have data listed by Tewarson for the radiant fraction of the chemical heat of combustion, whose values were used in calibration of the modified MLC for estimating radiant heat of combustion of unknown materials.

Citation

Dietenberger, Mark A.; Boardman, Charles R.; Stark, Nicole. 2017. Flammability properties and radiant fraction of FRT wood plastic composites using mass loss calorimeter under HRR hood. In: Interscience Communications Ltd, eds. Proceedings, Fire and Materials Conference. 6-8 February 2017: San Francisco, CA: 988-989.