Patent ID: 7513379

Claim:
A process for manufacturing a plastic fuel tank, said process comprising: forming a fuel tank with a wall defining at least one opening: placing at least one accessory at least partly outside the fuel tank such that said fuel tank and said accessory form an interface between said fuel tank and said accessory: forming a thin film of multilayer structure that includes at least one fuel barrier layer that is impermeable to gaseous and liquid fuels, said thin film having a flexibility substantially greater than that of said wall of said fuel tank; placing said thin film over said interface between said fuel tank and said accessory so that said fuel tank is sealed from an outside atmosphere at said interface by said fuel barrier layer of said thin film: and welding an entire outer periphery of the thin film directly to the tank around said opening of said fuel tank thereby connecting a first part of the film directly to the accessory such that the thin film extends across a seam between the accessory and the tank, wherein said forming of the thin film is preformed by thermoforming, independently of the forming of the fuel tank, before the welding of the thin film to the fuel tank.