Patent ID: 7311960

Claim:
A prepreg of a honeycomb sandwich structure precursor comprising: a honeycomb core; a stiffness-treated prepreg ply comprising: (a) a stiffness-treated fabric, consisting of a plurality of fibers and a polymerized precursor of a polymeric material disposed on the fibers, polymerized with a treatment selected from the group consisting of heat treatment, ultraviolet treatment, and free radical treatment, to polymerize the precursor of a polymeric material, where the stiffness-treated fabric exhibits an ASTM stiffness value not less than 7% greater than the ASTM stiffness value of an untreated fabric; and (b) a curable resin system applied to the stiffness-treated fabric prior to contacting with the honeycomb core; and a second prepreg ply selected from the group consisting of a stiffness-treated prepreg ply and an untreated prepreg ply, where the untreated prepreg ply comprises a curable resin system and an untreated fabric, interposed between the honeycomb core and the stiffness-treated prepreg ply; where the stiffness-treated prepreg ply exhibits a frictional resistance to the second prepreg ply greater than the frictional resistance between two untreated prepreg plies disposed against one another, so as to enhance resistance to core crush when autoclave pressures are raised to decrease void content of a honeycomb core during fabrication of a honeycomb core structure from the honeycomb core structure precursor.