An improved method of manufacturing a PEM fuel cell collector plate is
disclosed. During molding a highly conductive polymer composite is formed
having a relatively high polymer concentration along its external
surfaces. After molding the polymer rich layer is removed from the land
areas by machining, grinding or similar process. This layer removal
results in increased overall conductivity of the molded collector plate.
The polymer rich surface remains in the collector plate channels,
providing increased mechanical strength and other benefits to the
channels. The improved method also permits greater mold cavity thickness
providing a number of advantages during the molding process.