Some aspects of the self-heating and ignition of solid cellulosic materials

The self-heating and self-ignition of fibre insulating board and similar materials are discussed in the light of the well-known theory of thermal explosion. It is pointed out that the simple theory for a single reaction neglecting reactant loss during the induction period is inadequate for the interpretation of all the data published by Mitchell (1951). In the case of wood fibre insulating board it is suggested that the reaction leading to significant increases in temperature at relatively low ambient temperatures is not that responsible for ignition; ignition appears to be mainly the result of other reactions which become appreciable only at higher temperatures. Some experimental results in support of this contention are given, and it is estimated that the total heat of reaction is 80 cal g -1 . The induction times reported by Mitchell for three materials show one of them (cotton linters) to be different in its behaviour from the other two.