The Science Behind Your Windshield

Windshields have gone through one of the biggest evolutions since the automobile was invented. The earliest car windshields were made using ordinary glass and shattered easily, injuring passengers and those nearby. Starting with Fords in 1919, the process of glass laminating was used to increase safety.

Modern windshields are a little more complex than early windshields. They are made with laminated safety glass, which consists of two layers of clear glass and an inner layer of polyvinyl butyral. The inner layer is key to the windshield’s shatterproof capability: while the glass may chip or crack, the polyvinyl mix binds the glass layers together and provides visual clarity that would be difficult to maintain through the glass alone.

A windshield begins as a plain piece of glass. A machine called a plotter runs a wheel over the glass and scours it until it is in the desired shape, depending on the vehicle. A torch is run over the scour marks and the shaped glass is popped out of the sheet. This process eliminates most of the jagged and uneven edges of the glass, though the process still requires sanding and polishing through a process called seaming. The glass is seamed, washed and sprayed down with a formula of talcum powder and water so the glass won’t stick to another sheet of glass. A silkscreened border is sprayed onto the glass sheets to conceal any blemishes or imperfections, followed by a visual inspection. The windshield is put through a bending leer at 1382° Fahrenheit, where it is melted down to the correct angle, cooled and hardened. An opaque vinyl sheet, previously formed into the shape of the windshield, is placed between the sheets of glass and put through a nipper, a machine designed to get rid of air bubbles. Following the nipper is an hour in large pressure cooker called an autoclave. The autoclave is followed by the steel ball test. Steel balls are dropped on the windshield from several heights to prove the windshield’s durability. If it does not shatter, the batch is ready to move on to a final visual inspection before getting sold.

Carolina Windshield Centers provides some of the best repair and replacement services in Charlotte, Greensboro, Morrisville, and Hickory, North Carolina. We have expert glass technicians and provide convenience so you can get in and get out with the peace of mind your windshield will protect you. Call us at 800 900-1505 to request a quote or schedule your next appointment today!