The windshields themselves are made of a specialized form of glass designed for windshields. This glass is composed of silica, fine sand, soda ash, dolomite, waste glass and limestone. Certain formulations contain small amounts of potassium oxide and aluminum oxide. Laminated glass is formed by a thin layer of vinyl between two layers of glass.
This creates a thicker, stronger window. They are considered one of the safest types of glass because they are not easy to break or break. Most vehicle windshields are made of laminated glass. They are considered effective in preventing break-ins because of the effort required to break them.
Rear glass, also called rear window glass, rear windshield, or rear glass, is the piece of glass opposite a vehicle's windshield. The back glass is made of tempered glass, also known as safety glass, and when broken it breaks into small round pieces. This is different from a front windshield, which is made of laminated glass, glass consisting of two pieces of glass, with vinyl in the middle. Laminated glass is made by sandwiching a layer of polyvinyl butyral (PVB) between two pieces of glass.
Glass and PVB are sealed by a series of pressure rollers and then heated. This combination of pressure and heat chemically and mechanically bonds PVB to glass. Mechanical bonding occurs through the adhesiveness of PVB, whereas chemical bonding is created through hydrogen bonding of PVB to glass. Safety glass is used in all automotive glass.
It is made to reduce the likelihood of injury, should it break. Windshields are manufactured from a lamination process. Your car's windshield glass is made of laminated glass, which is designed to offer the highest levels of safety in the event of an accident. 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. When a small object hits a piece of safety glass, usually only the outer layer of the windshield that is hit breaks. Float glass is used to create laminated glass. Nearly all windshields in North America are made of laminated glass.
Laminated windshields are composed of two pieces of float glass with an interlayer of plastic between them. Think of a sandwich where glass is bread and plastic is a slice of mortadella. The resulting glass is much stronger than simple float glass. When laminated glass breaks, it breaks into small pieces instead of large fragments, which also makes safety that way.
Molten plastic is then injected into the mold, and after cooling, a plastic frame is formed around the glass so that the windshield can be shipped to a car or glass manufacturer. In 1903, French chemist Edouard Benedictus stumbled upon the secret of shatter-resistant glass when he dropped a glass jar filled with a dry collodion film. The glass is then tempered to improve its strength by rapidly heating the glass and then blasting it with cold air. Some of these companies include AGC Glass Company North America, Guardian Industries, PGW Glass, Pilkington North America and Vitro.
The glass then enters a special furnace called a furnace, where the glass is gradually cooled to approximately 200°C before cooling to room temperature when it is ready to be cut. 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. Ellen Rogers has been involved with the glass industry for nearly 20 years and is the editor of USGlass Magazine and Architects' Guide to Glass magazine. This “tempering process” makes glass many times stronger than untempered glass of the same thickness.
However, in severe impact situations, the glass “breaks”, but usually does not separate because broken glass pieces generally adhere to the vinyl inner liner. Tempered glass is manufactured by rapidly heating glass to more than 1000 degrees Fahrenheit and then rapidly cooling it to room temperature. That inserted layer of PVB is what allows the glass to absorb energy during an impact and gives it resistance to the penetration of flying projectiles. When tempering, when the glass is damaged, the windshield will break into many small pieces of glass without the sharp edges.