The combustion process of polymer is a complex coupling of energy feedback from a flame to the polymer surface with gasification of the polymer to generate combustible degradation products. In this paper the effect of the dimension of the polymer sheets upon the downward flame spread is studied by theoretical and experimental methods. In the theoretical method the effect of the dimensions of the solid fuel on the energy balance in the solid phase is studied by scale up method. This study show that the flame spread over the solid fuel is independent of the width of the sample if the ratio of the width to the thicknes s of the solid is higher than ten. The experimental results confirm the theoretical results.

Keywords