The automotive glazing meets very precise safety standards. It must prevent injury in case of impact, under normal traffic conditions. The degree of light transmission is also studied, for optimal visibility. Vehicles use two main types of glazing: laminated glass and tempered glass. The laminated glass consists of two single glass slides sealed by a polyvinyl butyral interlayer (PVB). The tempered glass is heated and suddenly cooled. It has a high mechanical strength and thermal shock. In case of breakage, its fragmentation is fine and not blunt.
- clear or tinted, green, blue, brown.
- athermic (violet blue exterior glare). The athermic windscreen prevents infrared and UV light from entering the cabin, but without affecting the brightness. It reflects 34% of solar energy.
- acoustics, which limits the spread of noise.
- heating, with the integration of wires in the glazing.
The windshield is an essential element of safety, in terms of airbags in case of shock (the windshield blocks the airbags). The windshield becomes bigger and bigger. The designers use the technological evolutions of the new windows and take the opportunity to replace the sheet by the glass. In 20 years, the glass surface has increased from 3.5 to 5 m² (i.e. the C4 Picasso from Citroën has more than 6 m² of glazing). The replacement of the windshield has become a very technical operation, only accessible to professionals trained and informed continuously.
Along with your car’s airbags and seat belts, the windshield is designed to help keep the car’s occupants inside the vehicle. In a collision, the seat belts prevent ejection, and the airbags cushion impact. The windshield provides another physical barrier to help occupants inside the car.
Airbags deploy with great force, and in some cases, windshields are designed to help with the deployment. Proper installation is critical to facilitate this intended action.
Rollovers have a higher fatality rate than any other vehicle accident and windshields help prevent damage by protecting the car roof from collapsing easily or caving in quickly. The windshield in a modern vehicle provides much of the support that steel A-pillars did in older cars, and this helps to prevent the roof from collapsing.
Visibility and Wipers
Being able to see what is ahead in the road is important to avoid collisions. In normal conditions, the glass windshield provides a clear line of vision.
Windshield Wipers are installed on the windshield to help remove debris, dust, water, and other conditions that can impair visibility. If there is any mist or fog built up on the windshields, then the wipers help clear it. The wipers also help in clearing off some amount of snow as well. Without wipers a windshield is incomplete.
A windshield looks like any other glass window on a car, but a lot of research, tests, and trial and error have taken place in order to create the perfect windshield for automobiles. The manufacturing process of the windshield glass has evolved over the years, and today the ‘float method’ is used. The early stages of the glass float in a chamber as it cools and cures to form the strong and protective windshield later on.
There are two types of glass that are used in a windshield:
This type of glass is on the side and the back windshields and they are made up of only one layer. This is because the side and rear windshields don’t require as much protection as the front ones. But still, tempered glass is quite strong enough to withstand any mild pressure and is very safe. The best thing about tempered glass is that when it’s broken, it shatters into many pieces that cause minimum damage as opposed to big shards that can easily cause cuts.
The front of the windshield is made of laminated glass. The glass is made up of 3 layers. PVB is the main material that makes up the middle layer of the glass and it protects from any external objects to penetrate or crack the glass easily. Laminated glass windshield is only on the front for the driver’s and front passenger’s safety.