FLAMMABILITY PROPERTIES OF HONEYCOMB COMPOSITES AND PHENOL-FORMALDEHYDE RESINS

The flammability properties of honeycomb composites, which are used in the interior cabin compartments of commercial aircraft, were examined. Analyses of the gases evolved during the thermal degradation of the components indicated that the phenol-formaldehyde resin makes a significant contribution to the flammability of these composites. The possibility that a more fire resistant formulation could be developed was examined by testing a series of resins which differed in the relative amounts of phenol and formaldehyde used in the reaction mixtures. The flammabilities of resins synthesized in excess phenol were measurably less than those synthesized in excess formaldehyde.