This post is the second in a series on the basics of auto glass, auto glass repair, and mobile windshield replacement. If you haven’t read part 1 yet, I recommend you do before continuing.
Types of auto glass (continued)
Non-tempered glass tends to shatter into long, needle-like shards. By breaking into so many small pieces, tempered glass is much safer for the vehicle’s occupants when it breaks. Car manufacturers also use single pane, tempered glass windows for the side and rear windows so that, should the vehicle’s occupants need to get out, for instance if the vehicle becomes submerged, they can break the windows and escape.
Windshields, on the other hand, are made of laminated glass. They typically contain two panes of tempered glass bonded to a central core, like a sandwich. This middle layer is made out of a material called polyvinyl butyrate, or PVB. PVB is extremely shatter resistant. So much so that an impact can shatter both layers of glass and the PVB layer will still keep the windshield in one piece and in the right place. That way, the windshield will stay in place even in a bad accident. This protects the passengers and keeps them in the car.
Windshields and passenger airbags
Windshield strength is also particularly important in vehicles with passenger airbags. This is because passenger airbags work by inflating and pushing against the vehicle’s windshield to create a cushion for the passenger. You might wonder, if laminated glass is so strong and durable, why not use it for all the vehicle’s windows? Well, if the side windows of your vehicle were made of laminated glass, it would make them essentially impossible to break out if you needed to escape through them. Nonetheless, some auto manufacturers have started to use laminated glass for the side windows of their cars. Why? Well, statistically, far more people are killed by being ejected from their cars than being trapped in them. Plus, laminated glass is much harder for a thief to break through.
Check back soon for Welcome to the Chapman Auto Glass Blog, Part 3! In the meantime, check out our page on mobile windshield replacement.