The side windows and rear windshield of a car are made of tempered glass, which is manufactured by rapidly heating glass to more than 1000 degrees Fahrenheit and then rapidly cooling it to room temperature. There are two main types of glass used when building cars: laminated glass and tempered glass. The glass generally used for the front and rear door windows and the rear window are made of tempered glass, while the windshield is made of laminated glass. Tempered glass is just as important to a vehicle's safety as laminated glass, but it differs greatly in both form and function.
This type of glass is used for the surrounding windows of vehicles (also called side windows) and the rear window (or backlight). Tempered glass is created by rapidly heating and then cooling the glass to room temperature by introducing it through a blower system. Safety glass is used in all automotive glass, as it is made to reduce the likelihood of injury, should it break. Windshields are manufactured from a lamination process, which consists of two pieces of glass with a thin layer of vinyl between them.
The three pieces are laminated together by applying heat and pressure in a special oven called an autoclave. When a small object hits a piece of safety glass, usually only the outer layer of the windshield that is hit breaks. Glass manufacturers continue to explore new ideas to make glass stronger, safer and more adaptable to new vehicles. However, in severe impact situations, the glass “breaks”, but usually does not separate because broken glass pieces generally adhere to the vinyl inner liner.
This type of glass is used in the side and rear windows of the vehicle and gains strength through a rapid heating and cooling process that strengthens the outer surface of the glass and its core. In addition, automotive glass is designed to be resistant to dust, dirt and impacts to prevent annoying particles from sticking to the glass and distorting the driver's line of sight. The second type of aftermarket automotive glass comes from the OEM, but was created on a different production line. Glass, in this case, is used to refer to the side windows, the deflector glass, the ventilation glass and the glazed roof (if the car has one). However, the most important glass in any vehicle is the windshield, which is made of laminated glass.
Laminated glass is made up of two pieces of glass with a thin layer of vinyl between them. The three pieces are laminated together by applying heat and pressure in a special oven called an autoclave. Different types of glass are used throughout the vehicle because each type has a different purpose. Automotive glass is exceptionally durable and responsible for 60% of the car's structural integrity in rollover accidents, while absorbing 45% of the crash impact during a head-on collision. The modern vehicle incorporates more glass than ever before, including larger windshields, sunroofs and even complete roof replacements with panels made out of glass. Laminated safety glass was born when PVB sheets were heat fused with two pieces of strong glass.
Laminated safety glass consists of two strong pieces that become one thick sheet by sandwiching a layer of polyvinyl butyral (PVB) between them. Laminated safety glass has been around for over a century and can be used in any situation where there is potential for impact by a person.