Abstract: The invention is a process for making a composite structure. In detail, the process includes the steps of: 1) laying up a plurality of sheets of fibrous material fully impregnated with a resin on a mold surface forming a lay-up; 2) forming a chamber about the lay-up; 3) drawing a vacuum from the chamber; 4) simultaneously with the step of drawing a vacuum from the chamber, providing a source of additional resin to the lay up, such that the additional resin is drawn throughout the lay-up; and 5) heating the lay-up until the resin is cured.

Abstract: Method and apparatus for making a fiber reinforced composite wherein fiber reinforcement material is disposed in a molding cavity formed between a substantially rigid molding tool and a compliant molding tool in a pressurizable chamber of a pressure vessel, such as an autoclave. Uncured polymer resin is introduced under pressure to the molding cavity by a resin pump disposed in the chamber or external thereof so as to initially infiltrate the fiber reinforcement material with the resin. The chamber is gas pressurized to provide isostatic pressure on the rigid and compliant tools during resin infiltration of the fiber reinforcement material. The resin-infiltrated fiber reinforcement material then is heated in the chamber to cure the resin matrix. Large surface area composites of the aerospace skin structure type can be made using the present invention.

Abstract: Ultra strong lightweight core material capable of sustained operation at unusually high temperatures for composite structure of the type used in aircraft parts such as wings, fairings and stabilizers is produced from preimpregnated thermoplastic fibercloth ribbon by the manufacturing processes of this invention. The fibercloth ribbon is preformed between corrugated rollers of a special roll forming press which heats the ribbon to a softening temperature, forms it into a pattern of half-hex corrugations, cools it and sets it in that pattern. Then sheets cut from the corrugated ribbon are stacked into a bonding press along with hex forming mandrels placed between the sheets in the corrugations.

Abstract: An isostatic pressurizing bag for consolidating a composite part has an outer flexible elastomer having a fixed resilient outside surface. The outer elastomer surrounds a closed chamber. A thermally expandable inner elastomer is located in the closed chamber. The inner elastomer is selected as an elastomer that can viscously flow or move in response to pressure. The outer elastomer is capable of flexure to relieve expansion of the inner elastomer. The bag is formed by curing plies of uncured silicone rubber around either a silicone gel or a particulated silicone rubber that is capable of phase change to a flowable gel in response to pressure. In use a composite prepreg is overlaid on a surface that defines the shape of a desired part. The isostatic pressurizing bag is located over the prepreg trapping the prepreg between the pressurizing bag and the surface.