Patent ID: 8043451

Claim:
A heating element for contact welding, comprising: a wedge shaped heating body for positioning between first and second sheets of plastic material, the wedge shaped heating body having a wide end positionable toward a supply of the first and second sheets of plastic material and a narrow end positionable toward opposed contact pressure rollers for pressing together and welding the first and second sheets of plastic material together after they have been heated by the wedge shaped heating element, the first and second sheets of plastic material being slideable along respective outer surfaces of the wedge shaped heating body from a separated position at the wide end toward an adjacent position at the narrow end prior to entering the opposed pressure rollers, the wedge shaped heating body heating the sheets of plastic material as they slide along the respective outer surfaces of the wedge shaped heating body; at least a portion of the wedge shaped heating body for contacting the sheets of plastic material being formed of a composite material including a ceramic material to provide anti-sticking and abrasion resistant properties to the wedge shaped body against the sliding sheets of plastic material and a heat-conducting material to provide an enhanced thermal conductivity to the wedge shaped heating body, as compared to a thermal conductivity of the ceramic material alone, for heating the sheets of plastic material, wherein the ceramic material is at least one of a boride, carbide, nitride, oxide, mixed phase and composite of at least one of aluminum, boron, silicon, titanium, tungsten, and zirconium; and wherein the heat-conducting material is a metalloid.