To reduce the amount of fuel vapor created in the fuel tank, we developed a variable-capacity, plastic bladder fuel tank that is efficient, reliable, and provides permeation prevention performance.
This bladder fuel tank changes in shape and total capacity in accordance with the volume of fuel it holds. Thus, in contrast to the conventional fuel tank, it can dramatically reduce the amount of fuel vapor that is ordinarily created in the fuel tank while the vehicle is being refueled, parked, or driven.
The bladder fuel tank has been adopted in the Vapor Reducing Fuel Tank System of the North American model Prius, a vehicle that operates under the Toyota Hybrid System (THS), which complies with the SULEV exhaust emission requirement.
This paper primarily gives an outline of the technology for manufacturing the bladder fuel tank.