Influence of carbon fibre orientation on reaction-to-fire properties of polymer matrix composites

The influence of the orientation of carbon orientation of carbon fibres on the reaction-to-fire characteristics of a layered composite has been investigated in detail. 8552/IM7 prepregs were laid up to give unidirectional and quasi-isotropic laminates. Specimen thickness (0.25 to 8.0 mm) and heat flux (15 to 80kW/m(2)) were varied for irradiation. Fundamental reaction-to-fire properties of this composite are interpreted on the basis of the matrix components: epoxy resin and polyethersulfone. Cone calorimetry and temperature distributions through the laminate showed that the velocity and degree of combustion are dominated by fibre orientation for a given resin. In general, a quasi-isotropic fibre orientation leads to faster ignition, because of preferred delaminations, but retards combustion processes more effectively than a unidirectional lay-up. Migration velocities of the pyrolysis zone were measure. Copyright (c) 2011 John Wiley & Sons, Ltd.