Patent ID: 8419881

Claim:
A method for manufacturing a hollow composite structure by air pressure without a tube, the method comprising: forming a prepreg product using a plurality of prepregs, the prepreg product having an inner surface and one or more open areas; sealing the prepreg product by forcibly inserting a silicone block into the open areas of the prepreg product; forming a coating layer by applying a coating material to the inner surfaces of the prepreg product; and compressing the prepreg product by applying pressurized air to the coating layer and, at the same time, applying heat to the prepreg product, wherein compressing and applying heat is carried out when the prepreg product is disposed within a mold, wherein one or more holes are provided in the mold and the silicone block, and wherein the coating material is applied to the inner surfaces of the prepreg product by injection of the coating material through the one or more holes.