Apparatus for bonding overlapping material layers

An automatic bonding apparatus for thermally induced seam bonding of weldable or gluable flat flexible material layers with each other which are each configured as a material web, a material band or a material piece and are arranged at least partially overlapping, the automatic bonding apparatus comprising:

• at least one electrical contact heating arrangement that is arranged at a carrier frame of the automatic bonding apparatus and includes
• a directly electrically powered and heatable heating wedge for locally heating at least one material layer of the flat flexible material layers to a bonding temperature, and
• at least one contact pressure and feed roller arranged at the carrier frame and driven by an electric motor for locally compressing a heated material portion of the at least one material layer,
• wherein an electronic control is used for adjusting or controlling a relative velocity between the flat flexible material layers, the automatic bonding apparatus, a temperature, an electrical power of a heating resistor, and the heating resistor arranged between two electrodes of the heating wedge that are separated by a flat insulating element,
• wherein the electronic control is configured to monitor the relative velocity and the temperature or the electrical power of the heating wedge during a bonding process at least in predetermined time intervals,
• wherein the electronic control is configured to automatically adjust the electrical power of the heating resistor upon a change of the relative velocity as a function of a determined relative velocity,
• wherein the electronic control is configured to increase the electrical power of the heating resistor upon an increase of the relative velocity,
• wherein the electronic control is configured to increase the electrical power of the heating resistor upon an increase of the relative velocity,
• wherein the electronic control is configured to decrease the electrical power of the heating resistor upon a decrease of the relative velocity,
• wherein the heating resistor is formed by a folded steel sheet blank whose kink forms a heating wedge tip and whose edges that extend parallel to the kink are attached at the two electrodes,
• wherein the heating wedge tip is arranged in a center plane of the flat insulating element and the folded steel blank is arranged mirror symmetrical to the center plane of the flat insulating element,
• wherein the heating resistor includes two sides that are oriented away from each other and configured to contact the weldable or gluable flat flexible material layers, and
• wherein an entirety of each of the two sides is concave.