Smolder Rates of Thin Cellulosic Materials

Abstract

Linear burn rates were determined for thin, cellulosic materials (papers and cotton fabrics) held in the horizontal plane by measuring the rate of radial increase of the circular burn pattern. Linear burn rates were determined for freely smoldering materials and for materials in contact with polyurethane foam. The linear burn rates of the freely smoldering materials were found to be inversely proportional to basis weight. This relationship held over basis weights from 0.8 to 24 oz/yd². The linear burn rates of the materials in contact with poly urethane foam were also inversely proportional to basis weight and were reduced about 16% from the free smolder rate. The effect of potassium ion content was also examined. A minimum level of potassium, approximately 1300 ppm, was re quired for sustained smoldering combustion. Above this minimum level, the ion content did not have a significant effect on the linear burn rate.