One melts silica sand of a certain purity. Gases are removed by additives. The melt cools down slightly and comes to rest at about 1100 ° C on an elongated, often endless tin bath. This process is called floating and results in the production of flat glass.
As soon as it's cooled down, it is cut into the desired shape by corresponding robots. Because today's disks are almost only just glued, each has on the inside an opaque surface, in order to hide uneven distribution of the adhesive.
In principle, all glass panes are printed on the later inside with the screen printing process. Thereby the filaments arise mostly on the rear window and often even several antennas. There are basically two panes consecutively manufactured of the same cut. The non-printed is placed on the printed side of the other and both heated to about 600° C.
Either by its own gravity or by additional shaping measures both have matching curvatures at the end. A plastic film resistant to yellowing, then comes between the two panes. Many panes are collected and come as package into an oven called autoclave.
They stay there at 140°C and 13 bar for two hours. Only then they will get rid of the milky lack of transparency. Most side and rear windows are made from single-pane safety glass. It will also cut and gets the printing and shape after being heated. However, it is cooled down more quickly by blowing of air.
Typical of such a Sekurit pane (hardened glass) is the decay in relatively harmless crumbs. However, the pane has still a considerable strength due to the slower cooling inner layer. To smash a side window, even a hammer blow may not be sufficient sometimes. Saint Gobain - 08/15