A method for combining the films used in packaging technology. Contact sealing: Using a (continuously heated) heating rod and counter-pressure bar. Pulse sealing: A sealing bar receives the necessary energy only for a short period of time. Continuous heat welding: Two (endless) moving belts are pressed together by heated sealing bars. Hot-wire welding: Films are simultaneously welded and separated with a heated wire; together with a welding bar, this is also known as separated seam welding. High frequency welding: Heat is generated by a radio frequency field. Ultrasonic welding: The pressure from the mechanical vibrations of ultrasonic frequencies is converted into heat at the contact surface of the films and creates the seal.