300C shattered back glass

[tint123]

I just wonder if it woulda shattered if the film had not been installed, a weak spot within the glass itself, maybe ?

[nctinter]

Have had this happen on a couple back windows a while back. Also Florida. I believe both were SUV hatches though. We never could figure it out. To me the best explanation was maybe by cutting the defroster square water had a reaction to the electricity and shattered it. Who knows. Luckily the dealer warrantied the windows. This seems so rare that I'd say it is a defect in the glass. I've had 3 Chryslers with defective rear defrosters.

[Sisqouc]

Check out the 2nd and 3rd pics in this link.

http://www.glassonweb.com/articles/article/330/

[TintDude]

Nice article.

I didn't know this:

Flat glass is toughened in an oven that resembles a giant toaster. The glass is transported on rollers and is rolled back and forth inside the oven and heated to a temperature of between 600 and 700 °C until it becomes soft. The glass in its softened state is rolled out of the oven into an air shower where both sides of the glass are cooled rapidly. Glass has low thermal conductivity so that the inside of the glass remains hot and soft while the two outer surfaces of the glass cool, solidify and then contract due to thermal contraction (thermal expansion in reverse).

After this the inside gradually cools, solidifies and contracts. Because the outer surfaces are already cold when the inner region begins to solidify, contraction in the inner region squeezes the outer surfaces. In the finished glass the regions near the outer surfaces experience high compressive forces which are balanced by high tensile forces generated at the inner region. The toughening process produces a safety glass that is also very strong.