POLYMER IGNITION

We describe a mathematical model to evaluate the critical heat dux req uired to ignite thermoplastics in radiative ignition experiments. The concept of a critical mass flux from the solid phase into the gas phas e is used as the criticality condition. Using this criterion, the soli d temperature corresponding to the critical heat flux is related to th e 'characteristic temperature' determined in Thermogravimetric experim ents (TG). We investigate the dependence of the critical heat flux and critical surface temperature on the value taken for the critical mass Aux. The specific application we have in mind is piloted ignition in the cone calorimeter.