Abstract: A method and an apparatus for conforming a blank onto forming surface sections of a forming tool by drawing a vacuum against an elastic vacuum bag for transmitting forming forces from the elastic vacuum bag to the blank. The elastic vacuum bag includes at least one bag section having a different stiffness than other bag sections. The at least one bag section is an elongated bag section having a stiffness larger than that of surrounding bag sections. The location of the elongated bag section of the elastic vacuum bag corresponds, when the elastic vacuum bag after completion lies against the forming surface sections having the blank in between, with an elongated forming surface section of the forming tool where the blank requires a forming force being larger than that of the surrounding bag sections.

Abstract: The invention relates to a method of manufacturing an integral article comprising a fiber-reinforced composite material. An inner tool body (12) of a cellular plastic material is provided, onto which an airtight sheet (14) of a flexible material is applied so as to fully encompass and seal the tool body (12). A plurality of layers (16) of fiber-reinforced composite material are then applied onto the outer surface of the airtight sheet (14), and an airtight vacuum bag (18) is in turn applied onto the outer layer of the composite material (16). The vacuum bag (18) is evacuated and the layers (16) of composite material compressed. The composite material is heat treated so as to cure the same. The vacuum bag (18) is then removed from the thus formed article. To form a hollow integral tank, the formed article is provided with a hole (22), and a solvent is poured therein to dissolve the cellular plastic material.