It’s one of the most common materials in the world and is used in everything from creating windows through to making ornaments and even complex light fittings, like Venice chandeliers. Even so, there are still a lot of people out there who don’t really know how glass is made.
Here we are going to break things down a little bit so that you can understand where different types of glass come from and how it goes from being a raw material into being one of the most important things in modern technology.
What Is It?
Before looking at how glass is made, let’s examine what it actually is. At its core, glass is made using sand and a number of other minerals, which are melted together at extremely high temperatures to form glass and other materials.
This process occurs naturally, as well as being done in a man-made environment. The mouths of volcanoes, in particular, are hotbeds of natural glass production, with the heat generated from volcanic eruptions causing sand near the volcano to become obsidian, a type of black glass that has strong properties and has been used at various points throughout history for weaponry, such as the tips of spears.
Interestingly, glass is, chemically, a liquid, even when at room temperature and seemingly solid. However, because of its thickness and stickiness, it acts and feels more like a solid. Once temperatures are increased, the glass starts to take on more liquid properties again, which is the point where it can be shaped into various objects.
How Is It Made?
We touched on this a little earlier with the mention of sand, minerals, and extremely high temperatures. Typically in modern glassmaking, sand will be combined with limestone and soda ash, with the mixture being heated in a furnace to a remarkable 1,700 degrees Celsius.
From there, the glass can be allowed to cool, during which time glassblowers and shapers can start working with it. However, additional materials can also be added to the furnace to lend the glass different properties and colours.
All of this, in addition to the speed at which the glass is allowed to cool, will vary depending on the needs of the glassmaker. As a general rule, stronger glass is formed by allowing the mixture to cool more slowly.
Further, various materials can lend glass different physical and chemical properties, making glass one of the most versatile materials on the market. That is why it can be used in everything from Venice chandeliers, car windscreens, and windows, through to complex fibre optics and smartphone screens.
Finally, one of the most attractive qualities of glass is its recyclability. All glass can be reused for as many times as is needed, with the glass itself maintaining the exact same properties.
In fact, glass may well be the only material used for packaging that is also 100 percent recyclable, which is one of the many reasons why it has been one of the most used materials in human history, with records of its use stretching back over 5,000 years.