Welding jaw and method for thermal welding

A method for thermally welding a pouch wall which is made of a plastic film to a welding region of a spout which is made of a plastic, the method comprising:

• providing two welding jaws which are arranged opposite to each other, each of the two welding jaws comprising a jaw body which is connected to a heat source, each jaw body comprising a first pressing surface;
• providing a pressing element which is arranged on the jaw body or which is fastened to the jaw body, the pressing element comprising a second pressing surface which is adjacent to the first pressing surface of the jaw body;
• moving the two welding jaws toward the welding region from opposite directions so that the pouch wall lying between the first pressing surface and the welding region is pressed against the welding region of the spout in a surface area to be welded;
• and
• pressing, via a movement of the second pressing surface of the pressing element, the pouch wall toward the welding region of the spout or toward a center longitudinal axis of the pouring channel in a surface area not to be welded which is adjacent to the surface area to be welded.