- Author
- Gann, R. G. | Earl, W. L. | Manka, M. J. | Miles, L. B.
- Title
- Mechanism of Cellulose Smoldering Retardance by Sulfur.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Book or Conf
- Combustion Institute, Symposium (International) on Combustion, 18th. August 17-22, 1980, Combustion Institute, Pittsburgh, PA, Waterloo, Canada, 571-578 p., 1980
- Keywords
- sulfur | cellulose | smoldering | inhibition
- Abstract
- The addition of elemental sulfur is effective in preventing cotton smoldering, a process which leads to a major fraction of fire loss. The objective of this work is to determine the mechanism of the observed retardance. Double thickness samples of cotton terrycloth, approximately 18 mm by 100 mm, were smoldered in a pyrex cylinder. The samples contained 0, 5, 8 and 10 percent sulfur by weight. The air velocity over the face of the sample was about 10 cm/s. Ten percent treated samples self-extinguished or smoldered with difficulty. The smoldering velocities and peak temperatures of the other samples were determined using embedded thermocouples; both decreased with increasing sulfur concentration. Calculations and experiments indicate that the sulfur does not simply act as a heat sink as has been suggested for many flame retardants.