Method for bonding at least partially overlapping material layers and automatic bonding apparatus for performing the method

A method 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 which are arranged at least partially overlapping, the method comprising the steps:

• using an automatic bonding apparatus;
• using at least one electrical contact heating arrangement that is arranged at a carrier frame of the automatic bonding apparatus with a directly electrically powered and heatable heating wedge for locally heating at least one of the material layers to a bonding temperature;
• using 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;
• using an electronic control for adjusting or controlling a relative velocity between the material layers and the automatic bonding apparatus and a temperature or an electrical power of a heating resistor arranged between two electrodes of the heating wedge;
• monitoring the relative velocity and the temperature or the electrical power of the heating wedge during a bonding process at least in predetermined time intervals;
• automatically adjusting the electrical power of the heating resistor upon a change of the relative velocity as a function of a determined relative velocity;
• increasing the electrical power of the heating resistor upon an increase of the relative velocity;
• and
• decreasing the electrical power of the heating resistor upon a decrease of the relative velocity.