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.

Failure Analysis of Broken Soda Bottle

Glass Failure Expert Performs a Failure Analysis Broken Soda Bottle;

The subject bottle had not yet been opened; it failed as it was being loaded into a cooler. The failure analysis photograph above shows the fracture origin. It shows that this bottle failed as a result of a defect on the interior wall of the bottle. In the photo the failure origin isin the top center. Apparently either the interior bottle walls touched during an intermediate stage of the blow mold process, or there was a bubble (seed) at or near this surface.