BigPatents India

Device for welding a moving packaging material (1) comprising a layer that can be heated by electro-magnetic induction and a thermoplastic layer incorporating a welding zone (2) which lies in the direction of movement of the packaging material; the welding device comprising an alternating current generator, a coil (3, 5, 6) for transforming the alternating current into a magnetic field, a ferromagnetic element (7, 8, 10-13) for channeling the magnetic field lines in a specific direction, the magnetic field being oriented so as to cross the packaging material (1) in order to induce heating of the layer that can be heated by electromagnetic induction; the welding device being characterized in that it comprises a set of ferromagnetic elements (7, 8, 10-13, 19-21) which are arranged so that the magnetic field lines cross the packaging material (1) in at least two distinct regions (14, 16-18) located along the welding zone (2).