COMPOSITE HONEYCOMB SANDWICH STRUCTURE

We eliminate resin flow into the cells of honeycomb in sandwich structure by using an unsupported film adhesive (108), a barrier layer (110), and a scrim supported adhesive layer (112) between the composit e laminate (102) and the core (106). We produce superior panels with lighter weights, improved mechanical properties, and more predictable structural performance by keeping resin in the laminate rather than losing it to the core cells. We reduce core crush and ply wrinkling in composite honeycomb sandwich structure by preventing slipping of tiedown plies relative to the mandrel and to one another during autoclave curing. We produce superior panels with lighter weights, improved mechanical properties, and more predictable structural performance. The method involves applying a film adhesive to the tiedown plies in the margin of the part outside the net trim line. Durin g heating of the autoclave and prior to the application of high pressure to the composite structure, the film adhesive cures to form a stron g bond between the plies and to the mandrel. When pressure is applied, the tiedown plies are locked together and to the mandrel to prevent slippage between any layers in the panel.