How Are Windshields Made?

by Novus AutoGlass Novus Auto Glass

Windshields are crucial for car safety. They keep the driver and passengers of an automobile safe from natural elements like wind and snow as well as flying debris. Moreover, they also play a vital role in preventing injuries if a car accident occurs. Windshields have been around since the 1900s and in the past were made of tempered glass. While it was hard and extremely shatter-resistant, the tempered glass was replaced by laminated glass which is currently being used in windshields. The reason for this primarily is that laminated Car Glass Repair is far safer than tempered glass. So, how are windshields made and what raw materials are used in the making of laminated glass? Let’s find out.

Raw Materials Used

Different oxides are used as raw materials for making laminated glass. These oxides include Calcium Oxide, Sodium Oxide and Silica. Limestone, Soda Ash and Sand are used for extracting these raw materials. Each oxide has a particular role to play in the formation of the glass. While Silica is the main ingredient for glass-making, Calcium Oxide helps in making the glass chemically durable and improves its hardness. The Sodium Oxide plays the role of the flux and is added simply to lower the melting point of the mix. There are several other oxides added to the mix for different purposes which include Aluminium Oxide, Magnesium Oxide and Potassium Oxide.

Glass Formation Process

The glass formation process starts with the heating of the mixture of the oxides and water in a chamber. Once the glass achieves a molten state, it is fed to a float chamber which is made up of molten tin. Here, the glass floats on the surface of the tin and achieves a flat surface and is rid of any impurities. Moreover, the glass is hardened in this float chamber as well before being fed to a furnace which cools it down and allows it to completely harden and take its shape.

The hardened glass is then cut into the desired dimensions using a diamond scribe. It is then fed to a mould which gives it the curved shape. The glass is again heated to a molten state in order for it to take the shape of the mould. After shaping, the glass is tempered by heating it to a high temperature and then rapidly cooling it down using cold air blasts.

In order to make laminated glass, two sheets of tempered glass are fused together with a sheet of Poly-Vinyl Butyral in between them. This process is conducted in an autoclave which not only uses heat but pressure as well to bind the three sheets together into a single unit. After lamination, the windshield is ready to be assembled onto the car frame.