Your vehicle’s windshield is one of its most important safety features. While it may look like any other glass, auto glass is designed to protect you in an accident.
Most types of glass, including the glass used in home windows, will shatter into sharp shards if broken. It doesn’t take much to break window glass, but auto glass needs to stand up to hazards like potholes, car accidents, and the occasional rock. To withstand these hazards and avoid shattering, auto glass goes through a unique manufacturing process.
How Auto Glass is Made
There are two types of automotive or safety glass: laminated glass, which is used for your windshield, and tempered glass, which is used for your back and side windows. While each has a slightly different function, both work to keep you inside your vehicle, shield you from sharp glass, and retain the integrity of the roof in a rollover.
Your vehicle’s windshield is made from laminated glass. This type of glass is made by layering polyvinyl butyral (PVB) between pieces of glass which are sealed together with pressure rollers and heat. The layer of PVB allows the windshield to absorb energy from an impact while protecting you from penetration from flying objects. While the glass can be punctured or broken, it will remain intact thanks to the PVB.
Tempered glass also serves an important role. Tempered glass is made by heating and rapidly cooling glass. Because the surface cools faster than the center and contracts while the center expands, the glass is stretched and compressed at the same time. This gives tempered glass 5-10x greater strength than regular glass. When tempered auto glass breaks, it shatters into tiny, dull pieces, not shards.
Auto glass serves many roles: it’s designed to resist punctures, it won’t break into dangerous shards, and it preserves the integrity of your car’s frame if you are involved in a rollover accident. If any of the glass in your car has been damaged, it’s important to have it repaired right away to retain these benefits so the glass can protect you in an accident.