Development of the fire-retardant sandwich structure using an aramid/glass hybrid composite and a phenolic foam-filled honeycomb

To improve the post-fire properties and fire resistance of the glass/phenolic composite, a phenolic coating and an aramid/phenolic composite layer were applied on the surface. The carbonization and impregnation of the phenolic matrix of the composite were repeated twice to eliminate the matrix cracking and delamination by fire exposure. Phenolic foam-filled honeycomb core was used to reduce the thermal conductivity and increase the stiffness and strength of the sandwich. Finally, the thermal insulation and post-fire flexural properties of the sandwich structure were estimated.