ANALYSIS OF EXPERIMENTAL DATA ON THE EFFECT OF BOTTOM VENTILATION CONDITIONS ON FIRE BEHAVIOR OVER A THERMALLY THIN NATURAL LATEX FOAM

The natural latex foam plays a significant role in our daily lives. Fire behaviors over natural latex foam under bottom ventilation conditions differs greatly from the normal one, and the influences of bottom ventilation conditions on fire behaviors were rarely addressed in the literature. Therefore, fire behaviors of thermally thin natural latex foam under different bottom ventilation conditions (bottom holes dimension from 0 mm to 15.0 mm) were investigated experimentally. It was known from the experiments that the combustion characteristic time decreased significantly with bigger bottom holes of dimension up to 4.0 mm, and then it kept the same, even the size continuing increasing. Flame showed a hollow structure under bottom ventilation. The flame spread rate of sample with 1.6 mm bottom holes was obviously lower than the others. A linear relationship was found between the flame spread rate and bottom hole dimension when it was larger than 2.3 mm. The flame spread for those samples with bottom hole dimension less than 1.6 mm almost happened at the sample surface, while for others happened both at the surface and at the bottom after bottom ignition. The preheat length showed an increasingly linear relationship with the dimension of the bottom hole.