Laminated Auto Glass
In order to create laminated glass for a windshield, manufacturers place one layer of polyvinyl butyral in between two portions of glass. Then, pressure rollers are used to seal the three sections. Lastly, the three layers are heated. This process enables the polyvinyl butyral to become mechanically and chemically bonded to the glass. The adhesiveness of the materials is what allows the mechanical bond to occur, and hydrogen bonding is what creates the chemical bond.
Advantages of Laminated Glass
Laminated auto glass offers Houston drivers and passengers a number of advantages. During a collision, the polyvinyl butyral will absorb the energy so that objects will be less able to penetrate the glass. Polyvinyl butyral also has the capacity to deflect nearly 95 percent of the sun’s ultraviolet rays. Even if laminated glass is compromised, the chemical bond will keep the glass from breaking into pieces and becoming flying projectiles.
With laminated auto glass, passenger air bags can be deployed correctly. When passenger air bags are activated, they initially expand toward the windshield before they move in the passenger’s direction. Because laminated glass is so strong, it can withstand the pressure created by the air bag and resists breaking. This is how the air bag keeps the passenger inside the vehicle.
Tempered Auto Glass
Manufacturers create tempered glass by sending it through a series of blowers that heat the glass and then quickly reduce it to room temperature. Because the surface cools before the mid-section does, the surface contracts, and this causes compressive stresses. At the same time, the center expands, and this causes tensile stresses. These two different stresses are pulling and pushing stresses, and they allow tempered glass to have compressive and tensile strength. This means that tempered glass is five to ten times stronger than it was before the heating and cooling process.
Advantages of Tempered Glass
Heat is released very quickly during the cooling process, so the edges of tempered glass are very weak. Therefore, manufacturers must ground the edges down. This allows the glass to shatter into diminutive and dull pieces when it is broken. That is because there is a difference between tensile and compressive stresses. During the tempering process, the pulling and pushing stresses create a great deal of energy that is released when the glass breaks, and this enables it to shatter into tiny pieces. In addition, tempered glass prevents the windows from breaking due to stresses caused by closing car doors, driving over potholes and minor collisions.
The Future
Manufacturers regularly place tempered glass in the side and back windows of a vehicle, but they are beginning to believe that it would be advantageous to use laminated glass for these windows. However, laminated glass presents them with a couple of problems. Because laminated glass is so strong, someone who is severely injured in a car crash will have an extremely difficult time breaking the glass and escaping from the vehicle if this is required. Also, the process used to create laminated glass makes it difficult to recycle the remaining product.
Although there are a few disadvantages to laminated glass, manufacturers are still in search of ways to increase the amount of laminated glass that they place in their vehicles. Cielo roofs are one example of how some manufacturers are managing to do this. These roofs combine the car’s windshield and roof to create a greater windshield area that reaches past the driver’s head.
At Apple Glass Company, we repair and replace damaged automobile glass. This will improve your safety by replacing weaker glass for stronger laminated or tempered glass. Contact us today for a free quote and to learn about our other services.
