Effect of folding width on a flame spreading rate for accordion folded paper

Abstract

In this study, a downward flame spreading experiment was performed using the origami sample, which was an accordion-folded filter paper with a constant folding angle of 80°. Flame spreading rates were measured by varying the folding width form 2.0 to 10 mm, and were compared with that of a flat filter paper. The overall width and length of the sample were 40 mm and 160 mm. As a result, the flame spreading rate of the folding width of 10mm was larger than that of the flat sample. On the other hand, when the folding width was less than 5 mm, the spreading rates of the accordion folded paper became lower than that of flat sample. Moreover, it was found that the local minimum value of the flame spread rate appeared at the folding width of 2.5 mm, and at around the local minimum value, the transition from flaming to smoldering combustion was sometimes observed.