Gas filling is as old as insulated glass production. When this success story of insulated glass started in the second half of the 1970s, went through a great deal of innovation and still continues today, the very poor thermal conductivity of Argon gas was, of course, recognized from the outset. To utilize this property insulated (or otherwise called Thermo) glass panels were filled with this gas. The air gap in between the glass panes (the volume of which was determined by the size of the heat-insulating glass and the width of the aluminum spacer bars) could accommodate a material that was colorless, but had good insulating property. At first the introduction of gas into the air gap was quite problematic because it was either rather slow process or there was a huge loss of Argon gas during the operation.
This was the reason for developing the gas filler machines. First versions of such machines used very simple solutions for gas filling. Using the volume calculated from the size of glass panel and width of spacer bar, it was possible to determine how long an insulated glass panel should be filled (with a certain hole diameter) to ensure that it was full. Results of these calculations were included in a table, which was attached to the machine. So it was pretty easy to start filling operation with using the table, setting a timer, and then after the set time, the timer stopped the gas flow and the machine switched off. This process had/has several disadvantages. On the one hand, the gas volume was not accurate, it was only approximate, so it was possible that the gas supplied was either inadequate or too much, resulting in large loss. On the other hand, it is very cumbersome to look for the size of each glass panel in the attached table and then set the machine accordingly. As a result, automatic gas fillers equipped with sensor have been developed, which are pretty popular machines to this day. These machines are different from their predecessors in that there is no need to adjust the filling time after finding the value from a table, but a sensor helps to ensure that the gas volume is neither too little nor too much. The gas filling operation is extremely simple, as so called “gas filler” corner pieces are fitted to the two diagonal corners of the insulating glass panel. Gas inlet hose is connected to the bottom corner piece and sensor hose to the upper corner piece. During the gas inflow, oxygen is gradually pushed out of space, so when it is completely displaced, the machine sounds an audible signal, stops the gas filling and switches off. The operation is fast, accurate and has no inert gas loss, and the equipment is easy to move due to its small size. Such machines are available in 1, 2 or 4 channel versions, as multiple channels can speed up the filling process. It should be noted here that this technology is no longer considered to be the fastest and most advanced due to the recent market expansion of gas-filling presses. However opinions on the efficiency of gas filling presses and their losses are divided.