Method and apparatus for welding plastic bodies

A method of welding two or more molded or hollow body members manufactured using injection molding technology into a plastic molded or hollow body, so as to form components for air conduction in internal combustion engines, comprising:

• providing the molded or hollow body members with at least two components, each of the at least two components being made of materials having different melting temperatures, and each molded or hollow body member having a joining region including portions of each of the at least two components;
• melting the molded or hollow body members to be welded together in the joining region of each molded or hollow body member by pressing thereon first and second contact elements heated to the melting temperatures of the respective joining region of each of the at least two components;
• insulating the first contact element from the second contact element with an insulator that is disposed in between the portions of the first and second contact elements that are pressed in contact with the joining region of each of the at least two components as the molded or hollow body members are melted by the first and second contact elements;
• and
• bringing the melted portions together by applying a molding pressure to form a completed component.