Joining method and machining head and manufacturing machine for carrying out the method

A joining method for connecting at least two thermoplastic workpieces, with the steps of:

• a) splicing edge regions on a first workpiece and a second workpiece in order to produce splice regions on each of the first and second workpieces region, wherein—at least one of:
• the splicing takes place by at least one of corresponding fiber placement, material abrasion, laser ablation, machining or milling, the at least one splice region is formed in a stepped manner by a plurality of workpiece layers of the workpiece, the splice region is pretreated by fibers of the workpiece being exposed, the splice region is pretreated by fibers of the workpiece being exposed by means of laser surface treatment, the splice region is pretreated by the first one of the workpieces being coated with a microstructured functional layer, or the splice region is pretreated by the workpiece being plasma-coated with a microstructured functional layer;
• b) positioning the first and second workpieces relative to one another in such a manner that the splice regions of the first workpiece and the second workpiece bound a seam region and are in mirror relationship forming a gap extending parallel to lengths of the first and second workpieces and between respective lowermost surfaces of the first and second workpieces;
• c) inserting a connecting body into the seam region and heating part of the connecting body by means of local input of heat in order to form an integrally bonded connection between each workpiece and the connecting body, and when the connecting body layer is inserted, the connecting body is pressed by a pressing device which detects the connecting body, and a counter pressing device which detects the first and second workpieces and the counter pressing device has a blade which is introduced into the gap between the respective lowermost surfaces of the first and second workpieces when the pressing takes place.