Abstract: Glass fiber reinforced epoxy prepreg, flame retardant adhesive film and high density Nomex honeycomb core were used to manufacture sandwich composites by co-curing process in autoclave. The rheological properties of epoxy resins from prepreg face and adhesive film, the influences of applied pressure and heating during co-curing process on the mechanical properties of as-prepared sandwich panels, were investigated to determine a moderate processing profile. Combined with the above results, the properties of sandwich panels manufactured by using different areal density adhesive films and ply structures were further measured. It is found that by increasing the areal density of adhesive film, climbing drum peel strength and long beam bending properties both improve obviously and there is no significant effect on flatwise compressive strength. However, the flame retardant properties, smoke density and toxic gas release properties all decrease. The experiment results also show that the Nomex honeycomb cored sandwich panels with symmetric ply structure have more mechanical stability than unsymmetric ply structures.

Key words: nomex honeycomb cored sandwich, rheology, co-curing, prepreg, adhesive film, ply structure