High Throughput Flammability Characterization Using Gradient Heat Flux Fields.
High Throughput Flammability Characterization Using
Gradient Heat Flux Fields.
(2612 K)
Gilman, J. W.; Davis, R. D.; Shields, J. R.; Harris, R.
H., Jr.
Journal of ASTM International, Vol. 2, No. 9, October
2005.
Keywords:
heat flux; flammability; flame spread; radiant panel;
polymers; heat release rate
Abstract:
The quest for small-scale flammability tests useful for
predicting large-scale fire test performance is an
enduring undertaking. Often, this work is motivated by
limited access to larger quantities of samples, in the
case of materials development efforts, and by the slow
turn-around and high cost of large scale flammability
testing. Use of Cone calorimeter data such as heat
release rate (HRR) and ignition data has been coupled
with various models to attempt to predict the
performance of materials in medium and large scale fire
tests. In some instances this has been successful;
however, the extensive amount of data that needs to be
acquired has motivated the High Throughput (HT)
Flammability program at the National Institute of
Standards and Technology (NIST) to develop flammability
characterization methods which significantly increase
the rate of data generation. The goal is to keep pace
with our sample preparation rate, which is a significant
challenge since our capability to produce samples,
either extruded rod, or gradient coatings, has developed
to a rate of one sample per minute! The efforts
described here are those specifically focused at
developing HT flammability analysis methods. The method
of evaluating the flammability of a sample at a variety
of fluxes simultaneously involves use of a radiant panel
to create a gradient heat flux field. Samples are
ignited in the high flux region and burned until they
self-extinguish. The local flux at this position is
termed the minimum flux for flame spread (MFFS). The
same general technique has also been accomplished on a
smaller scale using the Cone calorimeter. Here MFFS and
HRR can be measured concurrently.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899