Glass is somewhat of an enigma. It’s tough enough to protect us and yet shatters easily. It is made from sand but ends up totally transparent! Weirder still is the fact that it behaves like a solid but is also a kind of liquid. Glass is an anomaly, but one that serves us very well indeed. It is one of the oldest of man-made materials and is all around us, from the lightbulbs and windows to our mobile phones and laptops.
Glass is made from liquid sand. Glass can be made by heating up ordinary sand until it melts into a liquid. This doesn’t happen on a hot beach thankfully, as sand melts at an extremely high temperature of 1700 degrees Celsius!
When the heated sand cools down, it doesn’t turn back into sand but completely transforms and gains a different structure. It never quite returns to a solid though, no matter how much you cool it. It can best be described as a kind of amorphous solid or a liquid with crystalline properties.
It’s a highly versatile and popular material in our daily lives because it has incredibly useful properties. It is clear, cheap to produce, easily shaped in its molten state, resistant to heat and not chemically reactive. It can also be recycled infinitely. Should you experience a crack or break in your home’s windows or glass doors, you’ll need the services of an Emergency Glaziers Leicester like https://www.nandu.co.uk/glazing/replacement-glazing/
How is glass made?
Factories that produce glass mix sand with waste glass, limestone and soda ash and heat it all up in a large furnace. The soda ash is for lowering the sand’s melting point, which helps to conserve energy during the process. The major problem with soda ash though, is that it produces glass that can dissolve in water! That’s what the limestone is added for, to prevent this reaction from taking place.
Molten sand is poured into various moulds to make containers, glass bottles or any other kind of required object. It can also be floated on top of a large vat of molten tin to make flat sheets of glass for use as windows.
There are slightly different processes that glass makers can follow to produce different types and shapes of glass. Chemicals can be added to change the colour or appearance of the resulting glass.
For example, chromium and iron are added to glass to give it a green tint. The oven-proof glass we are used to, known as Pyrex is made by adding boron oxide to the molten glass. Fine crystal glass can be produced by adding in lead oxide at the molten stage. Bulletproof glass is made by layering sheets of glass and plastic which are bonded together. The glass we see in our car windscreens has to be tough and as such, is made by cooling molten glass extremely quickly which makes it harder. To make stained glass, different metals are added to the molten glass and it is the metallic compounds that produce the different colours.