Induction welding with an electromagnetic field concentrator

A manufacturing method, comprising:

• providing an induction welder including a first concentrator, a second concentrator and a coil extending within a first receptacle in the first concentrator and within a second receptacle in the second concentrator, the first receptacle projecting in a first direction into the first concentrator from a first face surface of the first concentrator, and the second receptacle projecting in the first direction into the second concentrator from a second face surface of the second concentrator;
• providing a first thermoplastic body arranged with a second thermoplastic body, the first thermoplastic body located next to the first face surface and the second face surface wherein the first face surface and the second face surface are disposed to a common side of the first thermoplastic body;
• and
• induction welding the first thermoplastic body to the second thermoplastic body to provide a weld seam between the first thermoplastic body and the second thermoplastic body, the first concentrator spaced from the second concentrator along the weld seam, the induction welding comprising
• generating an electromagnetic field with the coil;
• and
• concentrating the electromagnetic field with the first concentrator and the second concentrator onto respective regions of the first thermoplastic body.