Glass Failure Analysis of Vehicle Windows

Glass Failure Expert reminds users that there are two types of windows in automobiles. All the side and rear windows are made with fully tempered glass. This is required for safety. These windows will break into small "cubes", and they are less likely to cut the occupants during an accident. The windshield is made from laminated glass. The windshield consists of two pieces of 0.1" thick annealed soda lime glass with a 0.05" thick layer of polyvinyl butryl (PVB) as the inner layer. The PVB performs several tasks. It isolates the two pieces of glass. Therefore, a crack in the outer layer does not penetrate into the interior of the vehicle. The PVB also helps hold the windshield in place during an accident. Finally, it is there to restrain the occupants from going out the front during impact. The attached photo is a view of the edge of a windshield. In it one can see the three layers.