Glass Facts

  1.  Did you know there are different kinds of glass? In the auto industry, safety glass is used. There are two main types of glass used- tempered and laminated. Car windows and rear windows are typically made using tempered glass, while car windshields are laminated.

  • Tempered or "toughened" glass is made by applying controlled thermal or chemical treatments to standard glass, usually heating and cooling it repeatedly. Tempered glass is about 4 times stronger than normal glass, but it is still breakable. In fact, it is designed to shatter in very small pieces so that in the event of an accident, passengers are likely to have small cuts, instead of windows breaking into large shards of glass. Think of a puzzle breaking apart into smaller pieces.

  • Laminated glass is also stronger than normal glass; it is comprised of two or more thin layers of glass with a layer of plastic/ resin inbetween. This is so projectiles, like pebbles on the highway, do not usually pierce through the layers upon impact. Small projectiles will instead get caught in the plastic layer, which keeps the windshield mostly in one piece. educing injuries to a vehicle's occupants. Laminated glass is repairable, unlike tempered glass.

​  2. The first windshield was used in 1904. However it was only offered as an accessory, and because it was flat glass (which is the kind of glass used in homes, showers, and businesses) the windshields of that time broke easily and could cause harm to passengers.

 

The first company to use windshields as a standard feature was Oldsmobile in 1917. The first curved windshields, such as those used today, were debuted by Chrysler in 1934. Windshields were not mandatory for cars until 1937!

Soon cars became popular, more easily manufactured, and more affordable. Our national highways were built in the fifties and sixties, which is when safety standards began to raise. The sixties and seventies saw the beginning of Federal Motor Vehicle Safety Standards and the National Highway Traffic Safety Administration, which works with Congress to enforce regulations for vehicle safety still! 

glass comparison.jpg
Image by Will Creswick
1917 olds.jpg

 3. Windshield wipers should be replaced every 6-12 months, depending on frequency of use.

 When wipers deteriorate, they can lose contact with the surface of the glass, leading to squeaking noises, streakiness, and smearing. Old wipers that have stuck on debris can even scratch your windshield over time, reducing your visibility. Here's a tip- most chain stores that sell car parts and accessories will even install them for you.

P.S.- Windshield wipers were invented by a woman. Mary Anderson patented the first automatic windshield wiper in 1903- before Ford had even released the Model T! The flat glass windshields of the era were often two panes, and when the top one dirtied, it could be folded down. Before windshield wipers, the only way to clean the windshield was to go outside and manually wipe it clean with a rag... and if it was raining? Well, someone probably was having a bad day.

Mary Anderson and Patent_edited.jpg