US Patent 7504131 Method of making electro-conductive substrates

The electro-conductive substrate of the present invention may comprise filaments extruded from a die orifice and at least one metal powder dispensed from a second orifice of the same die unit by way of a gas or liquid carrier. As the polymeric filament is extruded from the die, one or more metal powders may be simultaneously dispensed to coat the surface of the filament. As the polymeric melt and metal powder is extruded, air pressure is impinged upon the metal powder directing the powder toward the extruded filament. The metal powder adheres to the molten polymer as it is extruded for the die, coating the surface of the filament. The metal powder may also be incorporated into the polymeric melt prior to extrusion.