Burning Rate and Flame Heat Flux for PMMA in the Cone Calorimeter.
Burning Rate and Flame Heat Flux for PMMA in the Cone
Calorimeter.
(2959 K)
Rhodes, B. T.
NIST GCR 95-664; Thesis; 125 p. December 1994.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Order number: PB95-216990
Keywords:
cone calorimeters; burning rate; heat flux; polymethyl
methacrylate; ignition; experiments; mass loss; heating;
thermoplastics; small scale fire tests
Abstract:
Ignition and burning rate data are developed for thick
(25 mm.) black Polycast PMMA in a Cone Calorimeter
heating assembly. The objective is to establish a
testing protocol that will lead to the prediction of
ignition and burning rate from Cone data. This is done
for a thermoplastic like PMMA. For black PMMA, ignition
temperatures of 250 to 350 deg C and vaporization
temperatures of approximately 325 to 380 deg C were
measured over irradiance levels of 15 to 65 kW/m(2).
The incident flame heat flux, for irradiation levels of
0 to 75 kW/m(2), is found to be approximately 37 kW/m(2)
for black PMMA. Its constancy is shown due to the
geometry of the Cone flame. Also, this flame is shown
to be nearly transparent for Cone irradiance (>90%).
The heat of gasification of the black PMMA used is found
to be approximately 2.8 kJ/g; higher than other values
reported for PMMA. This is believed to be due to
differences in molecular structure or pigmentation
effects and the types of PMMA tested. A burning rate
model is demonstrated to yield good accuracy (>80%) in
comparison to measured transient values.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899