Glass is a very widespread material in our society. We all know its characteristics, a transparent material, fragile, with a certain thickness and weight… But what is glass made of? How it is made? What types of glass are there?
If you know the answers then go check out another article, maybe start here. If you are interested? Keep reading as we explain in a simple way how glass is manufactured
But before we do that, let’s highlight the importance of glass in the development of humanity, because glass is not only useful in our daily lives as a material in which we use for drinking or from which our windows are made.
Glass has played a very important role in the development of technology and in the current perception we have of nature.
With glass, we were able to make microscopes with which we discovered microorganisms and we were able to create telescopes with which to observe the Universe.
The truth is that glass for us has a wide variety of uses and thanks to its versatility it is worth knowing a little more about such materials. So let’s get to it…
The glass comes from siliceous clay or sand
The glass is either obtained from a mixture of silica sand or clay with dry powdered metal oxides which are introduced into a fusion reactor at temperatures exceeding 1,832°F (1,000°C).
During this fusion process, the mixture forms a viscous liquid that becomes transparent and when it cools down it acquires consistency and can be shaped.
Clay is a material obtained as a result of the erosion of the earth’s surface made by the movements of water, wind, glaciers and terrestrial movements.
But how come clay turns into glass??
It seems strange, right?
Well, the clay major component is aluminosilicate (a compound made of silicon and aluminum). When subjected to temperatures close to 2,732°F (1,500ºC) it begins to undergo compaction and later transforms into liquid glass.
Around 1,832°F (1,000°C) the glass behaves like a kind of chewing gum making it easier to be worked out to achieve different and unique forms.
Types of glass according to the composition
Due to the great variety of clays that exist in the world, the type of glass depends on the clay that is used. So let’s see the types of glasses that exist according to their composition:
This type of glass is made up of silica, sodium and calcium. Without calcium, the glass would be soluble in water, so it would practically not serve us at all. This type of glass is used to make the windows of buildings.
In this type of glass, calcium is substituted by lead, the result is a glass that is as transparent as the Soda–lime glass, but much denser, which is why it has greater refractive power and dispersion.
These properties allow it to be used as optical glass, that is, they are excellent for manufacturing cameras. Also, this glass can be worked at lower temperatures and can be easily engraved.
Borosilicate glass is the one that is usually used to make kitchen utensils or for laboratory materials. Its composition of silica and boron (mainly) makes it very resistant to heat and changes in temperature.
Perhaps it is the purest glass that exists, with 96% silica, you get the toughest and hardest glass to work with.
This type of glass is very resistant, with a softening temperature at above 2,732°F (1,500ºC), it is mainly used for materials that require exceptional resistance to heat, such as oven glasses or germicidal lamps.
Types of glass according to your application
Apart from these types of glass whose difference lies in the composition of the glass, there are other types of glass that depends on the application to which they are made for.
In this case, we refer to special types of glass, such as security glass or tempered glass, armored glass and insulating glass.
Safety glass or tempered glass
Surely you have heard about tempered glass, you may even have had the opportunity to see how a tempered glass breaks. This type of glass dominates the windows of cars, especially in the front and rear windshields.
It is called safety glass because of the way it breaks makes it very difficult for you to get splinters fly off which can cause you a cut. But it is not a different type of glass, only that the way it is made makes it have these special characteristics.
Tempered is made of different glass plates glued to each other, then they are introduced in a sort of oven that heats them up to a certain temperature. The next step is decisive, it is about cooling the plates with air, this very process is known as tempering.
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This technique is done by cooling with air, which causes a compression force on the surface that causes the interior of the glass to tighten. Thus giving the material great strength, but also, the plastic plate can be introduced between the glass sheets so that besides being more resistant, if it breaks, it does so in small pieces to avoid splinters that can cut us.
Armored glass or bulletproof glass
It may seem strange to you that glass is capable of resisting the impact of a bullet, but the truth is that it does exist. It is known as combined safety glass and consists of overlays of glass and plastic sheets.
These layers are glued and pressed, then they go through a process that submits them to high pressures and temperatures, and finally, a very thick and bullet resistant glass is obtained. Even sometimes, it can be reinforced with a wireframe or steel plates.
These glasses are used both for thermal and acoustic insulation. Here, two glass plates are also used, but they are left slightly separated from one another to ensure that the intermediate spaces remain, but are sealed.
This way the slight layer of air left between the two plates which reduces the heat and sound passage significantly.
As you can see, there are many types of glass that exist and with the different manufacturing process. What is impressive is that material as the clay can give birth to a material as peculiar as glass.
Do you know something we did not mention above about glass? Share with us in the comments below.