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Busch R5 RA are used for the evacuation of vacuum chambers. Source: Busch Vacuum Solutions.

Glass Coating Under Vacuum

Pumps and boosters from Busch Vacuum Solutions are used for the coating of low-E glass (low-emissivity glass) under vacuum.

A total of ten R5 RA, fourteen PANDA WZ, two COBRA NC and two ZEBRA RH are in use at a customer site to evacuate several vacuum chambers. Glass coating takes place inside these chambers with the aid of what is known as magnetron sputtering. In this process, the coating material (such as silver) is placed opposite the workpiece (glass) that is to be coated. After evacuating the chambers, an inert gas (usually argon) is introduced and a voltage of several hundred volts is applied. As a result, the argon ions crash onto the coating material and release atoms from it. These condense as a thin layer on the workpiece.

Low-E window glass created in this way allows better energy control because the coating reduces the absorption of infrared radiation. Visible light is transmitted, but heat remains on the side of the glass from which it comes. This means that heat is preserved inside the room in winter and is kept out during the hot summer months.