PURPOSE: To hold low fuel permeability and to maintain excellent durability and corrosion resistance for a long period.
CONSTITUTION: The tank main body 2 of a fuel tank 1 is made of a polymer alloy material. A copper plating layer 5 having 3μm film thickness is formed on the inner and outer surface of the tank main body 2 by an electroless plating method. Also, on the surface of the copper plating layer 5, a nickel based plating layer 6 having 1μm film thickness composed of nickel-phosphorus compound is formed by the electroless plating method. Total film thickness of both formed plating layers 5, 6 is 4μm and is sufficient to surely prevent from permeating fuel. The copper plating layer 5 has excellent adhesion to the tank main body 2 and is hardly stripped. Furthermore, the nickel base plating layer formed on the outermost surface of the fuel tank 1 has excellent corrosion resistance.
OGISU YASUHIKO
MORI TAKAAKI
