Study of Downward Flame Spread and Fire Risk Evaluation of the Thermoplastic Materials

This paper focuses its attention on the combustion characteristics and fire risk evaluation on the downward flame spread of polypropylene (PP) and polymethyl methacrylate (PMMA). Many characteristic parameters have been measured under different widths of samples, including flame spread rate, flame height etc. It is shown that the flame spread of PP and PMMA are diversed for different pyrolysis mechanism. The width of test sample has different impact on the fire spread rate, flame height and CO emissions during the burning period. As the width increases, the fire spread rate and flame height of PP decreases first, and then increases, while that of PPMA increases monotonically. The volume fraction of CO of PP and PPMA increases, but the effect of the width on sample PP can be neglected. Based on the Analytic Hierarchy Process (AHP), the evaluation of fire risk has been conducted. The flame height, flame spread rate and toxic gas generation rate are selected as the basic evaluation index parameters to establish a comprehensive evaluation model of fire risk. The evaluation results indicates that the fire risk of PP is greater than PMMA.