One example of how your vehicle’s windshield protects you in the event of an accident can be illustrated in the way the windshield is made. Every auto windshield is constructed of two sheets of glass, separated by a thin layer of polyvinyl butyrate in between. This transparent sheet of plastic is fused between the layers of glass in an adhesion process which utilizes pressure and heat to bind the layers together.

In the event of a collision, the glass may break; however, the thin layer of adhesive plastic in the middle will keep it together. This serves a dual purpose. First, the adhesive will prevent the majority of the glass from shattering and causing cuts and scratches to the occupants. Secondly, it allows the windshield to provide somewhat of a cushion to the passengers, should they strike the windshield. The polyvinyl butyrate is flexible, reducing the amount of force exerted to the occupants upon impact with the windshield. This is why windshields are constructed from glass the way that they are, rather than being constructed from plastic. Plastic does not provide the same amount of flexibility and cushion during an accident.

Windshields are constructed from laminated glass. This laminated glass is composed of two or more layers of glass, with a thin plastic sheet in between. This transparent sheet of plastic is actually called polyvinyl butyrate, or PVB, and is fused between the layers of glass in an adhesion process which utilizes pressure and heat to bind the layers together.

The PVB film keeps the glass from shattering in the event of an accident. On impact, most of the glass is kept from entering the vehicle’s cabin, and can even act as a retainer to keep objects, including you, inside the vehicle.

A qualified auto glass service specialist will be able to clearly make known whether your windshield needs to be replaced or repaired. In general, a windshield should only be repaired if the damage is not too extensive or if distortion will not result from the repair.

Most importantly, if the windshield’s inner layer of polyvinyl butyrate has been affected in any way, the windshield should be completely replaced. This adhesive layer is the most important aspect of any vehicle’s windshield, and is what keeps the windshield from shattering into many pieces when impacted.