subject: How Do They Make Those Double Glazed Windows? [print this page] Double glazing most insulated windows are double glazed because two panes of glass are more efficient than one. Contrary to popular belief, it's not the extra glass providing the insulation, it's what is in between the two panes. An insulated window must have an airtight frame and be able to withstand storms, cold, and heat. For this reason, the frames are generally made from vinyl extruded sections, which has the same insulating qualities as wood, but is also crack resistant and will not shrink as wood does.
The parts for the window frames are cut to size in a very fast saw and the ends are heated to just over 250 degrees centigrade and brought together while hot so they become welded together in the size required, by computer controlled machinery. After cooling, the rough edges are sanded with automatic computer controlled equipment. This creates a frame with airtight joints and no chance of leakage at the joints, as would not be the case with wooden frames. Silicone sealant is applied to the inside of the frame, then it's ready for the glass. A robotic arm grabs the glass and lays it onto the cutting table, where a carbide wheel then lightly scores the glass along the line ready to be snapped by a human hand. It is quite surprising how little pressure is required to snap the glass once it is scored to the correct depth, too much pressure when scoring will cause the glass to crack in irregular places and render the whole sheet useless.
The two pieces of glass are now the correct size, and one piece is stuck to the spacer, which resembles a small window frame, then the other piece of glass is brought together and they are then stuck together. The unit then goes into an oven where it is all cured and firmly fixed by the curing action of the heating oven.. Then when it comes out of the oven, it is injected with the vital ingredient, argon. Argon is an invisible inert gas which is far denser than air, this is what makes it such a good insulator. The argon is put into the unit by being pumped into a hole made in the spacer between the two panes of glass, and the air comes out at the top through another tube that is inserted into the unit for this purpose. When the unit is full of argon, both injector and air removal tubes are extracted and the holes sealed with sealant and the units are fixed into their frames, ready to be fitted into your new house.
