Every cooling device, whether refrigerator or air conditioner, has a cooling circuit consisting of copper tubes in which coolant circulates. On the assembly lines the copper tubes must be vacuum treated in order to remove the air from the cooling circuit, and subsequently the gaseous coolant is introduced through a filler valve. After filling the filler valve is cut off by a single scissor-like movement of the ultrasonic welding machine during which the tube is also welded to be gas-tight so that the cooling circuit is hermetically sealed. The entire process is finishes in less than one second as a rule, thus predestinating this method for mass production programs.
