How The Windshield Started

Most early cars did not have a windshield, they were manufactured with an open air

design.

Drivers wore goggles to protect their eyes from the elements.

The windshield became popular because it was an improved way to protect yourself

and your passengers from wind and debris.

The first windshields were made out of glass.

Instead of helping people, the shattering glass on impact would actually cause more injuries, then the windshield was meant to

protect.

That is why auto manufacturers switched to using tempered glass.

Tempering is a special process which makes the glass more shatter resistant.

How A Windshield Is Made

Most windshields are made using the “float method”.

A special formula consisting of silica, soda ash, dolomite, cullet, and limestone mixed together, and then sent through a chamber

known as the float chamber.

The float chamber is made of a sheet of molten tin, reaching a temperature of 1800

degrees Fahrenheit, where the glass is passed above this section of molten tin.

The intense heat of the chamber causes the glass mixture to float above the molten tin while removing any impurities within the

glass.

As the glass exits the float chamber the change in temperature causes the glass to harden just enough to move into the next

chamber.

The next chamber, at around 400 degrees Fahrenheit, is much cooler than the float

chamber.

This temperature allows for the annealing process where the glass is cooled slowly to

make it stronger.

After exiting the last chamber the glass is cooled to room temperature and is now

ready to be cut.

The section of glass is now placed into a mold that is heated to allow the glass to take

the shape of a windshield.

Once the glass has taken its shape, the lamination process begins.

A layer of poly-vinyl butyral is sandwiched between two sheets of tempered glass and

heated with an autoclave.

The heating process turns all the layers clear making it see-through.

Windshields Have Improved

New research is being conducted every day to develop new ways to make glass safer and

more durable.

Some glass can even resist UV light, fix scratches on its own, and has anti-fog

capability.

Being shatter resistant and coated to reflect some of the sun’s rays the windshield has

now become one of the car’s most important designs and safety features.