Cars are amazing creations when you think about it: these are incredibly heavy wonders of engineering, capable of taking you anywhere in the world (almost) at insane speeds. For the most part they're incredibly reliable too and these days they come so packed with features that you can pretty much live out of them.
But despite the wonderful technology under the hood, most of us tend to take our cars somewhat for granted. They've been around as long as we can remember and they always just work… so we tend to forget how marvelous they are (unless you're a real petrol head of course).
In reality, even the most minute and seemingly uninteresting aspects of cars are actually small miracles of engineering. Take your car windshield for instance: what is there to say? It's just a piece of glass right? No, not at all…
The History of Car Windshields
Car windshields were introduced by Henry Ford when he unveiled his first automobile. At this time though, the windshields were somewhat different from today, being made of regular glass – actually just like the glass you have in the windows of your home. The problem with this soon became apparent though as people started having accidents and getting impaled by large shards of glass.
A rethink was needed and so Ford went back to the drawing board. His next windshield design was made from safety glass, much like the stuff that stuntmen use in movies to smash bottles over their head. This glass would crumble on impact into tiny grains, thereby making it much less dangerous to drive around behind.
Unfortunately though, this new safety glass had problems of its own: being so quick to shatter that every pebble or acorn ended up breaking through the glass and requiring repairs.
This led to the creation of the modern car windshield that we rely upon so much today…
The Modern Car Windshield
Modern car windshields are made from not one but two layers of glass that fit precisely together like a sandwich. They're the exact same shape so from the inside they still look like one piece of glass.
In between the two identical panes though is a sheet of laminate plastic that's adhesive on both sides. The role of this plastic is to hold the glass in place, thus meaning that if it shatters because a stone comes through the window, it will all be held together still and it will 'hang' in place.
Better yet, the two layers of glass mean that a stone or other projectile is unlikely to make it all the way through – more likely it will just damage the pane on the outside keeping the integrity of your car uncompromised.
That thin layer in between the glass also makes the windshield more insulating, helping to maintain the conditions inside the car and making it more energy efficient to heat or cool.
This thin gap also has other advantages, as it allows you to run things in between the two layers. For instance this is how heated windshields work – they have a very thin wire mesh running between the two panes of glass that can warm up slightly in order to help melt ice and get rid of condensation.
Finishing it all off is an incredibly powerful bonding agent that actually joins the glass to the outside of the car at the atomic level. This ensures that the windshields remain perfectly air tight and also helps to support the roof of the car in case you roll your vehicle.
So there you go: they look quite dull, but in fact windshields are just as amazing as the rest of a car design!