Radiant Ignition of Polyurethane Foam: The Effect of Sample Size

Hadden, Rory, Alkatib, Abubakar, Rein, Guillermo and Torero, Jose L. (2012) Radiant Ignition of Polyurethane Foam: The Effect of Sample Size. Fire Technology, 50 3: 673-691. doi:10.1007/s10694-012-0257-x

Author Hadden, Rory
Alkatib, Abubakar
Rein, Guillermo
Torero, Jose L.
Title Radiant Ignition of Polyurethane Foam: The Effect of Sample Size
Journal name Fire Technology   Check publisher's open access policy
ISSN 0015-2684
Publication date 2012-04
Sub-type Article (original research)
DOI 10.1007/s10694-012-0257-x
Volume 50
Issue 3
Start page 673
End page 691
Total pages 19
Place of publication New York, NY United States
Publisher Springer New York LLC
Collection year 2013
Language eng
Formatted abstract
Although smouldering ignition of upholstery items remains a leading cause of residential fire deaths, relatively little research is conducted on the topic. An experimental investigation of the effect of sample size on the ignition and spread of smouldering and flaming in polyurethane foam under natural flow conditions is reported here. Polyurethane foam samples are used because this is a common material in modern, residential environments and one for which there exists significant quantities of previous experimental data in the literature. Samples of different square cross-section size and a fixed height of 150 mm are insulated on all sides except the top which is exposed to a radiant heat flux and is open to the air. Samples with side lengths of 50 mm, 100 mm, and 140 mm are studied. Ignition and spread dynamics are diagnosed using thirteen thermocouples located along the vertical centre line. The onset of smouldering ignition (13 {Mathematical expression}, 8 {Mathematical expression} and {Mathematical expression} for 50 mm, 100 mm and 140 mm sample sizes respectively) is observed at significantly lower heat fluxes that flaming (45 {Mathematical expression}, 32 {Mathematical expression} and {Mathematical expression} respectively). Critical heat fluxes for smouldering and flaming ignition increase with decreasing sample size, with smouldering ignition being significantly more sensitive to sample size than flaming ignition under the size range studied. Smouldering spread rates are measured in the range from 3 {Mathematical expression} to {Mathematical expression} and found to be a strong function of the heat flux and depth of the smoulder front. The effect of sample size on smouldering has been theoretically proposed before but this is the first time that this effect has been demonstrated experimentally for ignition. The fact that large samples result in the lowest critical heat flux could have implications for testing procedures and translation of results from small-scale testing to real-scale in the built environment.
Keyword Cone calorimeter
Sample Size
Smoulder propagation
Transition to flaming
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Civil Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 1 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 3 times in Scopus Article | Citations
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Created: Thu, 28 Mar 2013, 08:56:40 EST by Julie Hunter on behalf of School of Civil Engineering