Flammability of FRP composites

After recalling the basic mechanisms involved in the combustion of 

A general scheme which summarizes the necessary conditions for combustion to occur is represented by the fire triangle (Fig. 12.26). This scheme involves three factors the fuel materials (polymer matrix, and in some cases organic fibres), the combustive element (oxygen) and an additional heat source. If one of these factors is removed, the combustion phenomenon will not take place. 

The initial phase consists in the heating of the FRP composite under the effect of an external heat flux produced by a pre-existing fire or a radiant source. The resulting temperature increase leads to the softening or even the melting of the polymer matrix in the case of thermoplastic systems. Thermosetting systems are less affected, due to their cross- 

Non-combustible products (gases and solid char residue) 

The third step involves the ignition of the combustible gases, provided 

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