What is glass, and how is it made? Surprisingly, not too many people know what glass actually is. Most think that they know, but they’re wrong! Almost every piece of glass you will ever see was produced in a large furnace heated to very high temperatures.
This process is known as melting. As the heat is applied to the glass, the atoms of each element come together and fuse or solidify into one unit.
After this happens enough times, we have a nice, clear block of material. This material is now melted down and formed into whatever shape the next step demands.
There are several types of shapes that glass can be worked into. Some require more time to take form than others do, which is why some are done with more ease. But overall, all glasses go through the same steps.
The article writer will going over different types of glass and how they are made here.
Making the raw materials meltable
The first thing most people do not realize about glass is that it is made of pure silica! This makes sense, because you can make almost anything out of glass including dishes, windows, and even some bathrooms are made from nothing but glass.
But unfortunately, this also means that you cannot mix silica into other substances to create new materials. It will simply burn away.
So how then do we make glass? We start with raw materials such as silicon dioxide or just “silica” for short. Then we heat them up in a process called fusion, where the atoms actually melt down and combine to form something else.
The difference between these two types of melting is determined by temperature. Fusion happens at higher temperatures, so instead of combining with another element, it breaks apart and forms molecules of oxygen and silicon. These molecules bond together later to form either normal glass or an oxide layer of glass which prevents additional chemical reactions.
Molten glass
Photo by Francesco Ungaro on Pexels
Before being shaped into any kind of container, molten glass has to be worked. This is when the materials in glass are mixed together and heated up so that they can take on new shapes.
Heating up glass also allows it to move more easily, which is why most glass is melted down and then pressed or rolled into thin sheets or rods. These sheets and rolls can then be cut andshapedinto whatever shape you want!
The process begins with raw material, usually silica (the main ingredient in sand) combined with other ingredients such as soda (sodium carbonate) and potash(potassium oxide).
These chemicals are mixed into the hot, liquid state glass and then stirred in. The whole mixture is heated and spun at high speeds to create an extremely fine powder. When this cools down, it forms pure quartz, one of the many possible crystal structures of solid matter.
This stage is called frit. It’s not quite ready for shaping yet. Now it needs to be spread out onto a cold, smooth surface using a device called a dragoon.
A dragoon spreads the glass by dragging a rod across the top edge, creating a sheet of glass about 0.5mm thick. Repeat this several times and you have layer upon layer of glass.
You could now roll these layers up into a tube, but there’s another way to make thinner pieces.
The kiln
After raw glass is melted down, it must be cooled quickly to ensure that it does not melt completely. This is done in what’s called a kiln!
The process begins by heating up the empty chamber of the kiln until it reaches 2200° Fahrenheit (1200 Celsius). At this temperature, atoms are moving very fast, which helps solidify the material.
Next, molten glass is mixed with chemicals such as silicon or potassium carbonate to create another liquid that can be poured into the hot chamber.
This new liquid is then spread across the surface of the heated chamber using a device called an agitator. As the agitator spins, it pulls some of the gas molecules out of the liquid, creating bubbles.
As the heat disperses, the shape of the glass changes slightly, so it is necessary to check it frequently.
The factory
Most glass is made in factories, where huge machines shape and roll molten glass into thin sheets or shapes of containers. These sheets are then cut and polished to make various sizes of clear products such as windows or bottles for drinks.
The thickness and size of each sheet depends on how thick and what size container it will be used in. For example, a 1 inch wide window goes through more than 100,000 times in this process!
Window panes usually get attached to other panes or to a frame using heat activated glue which solidifies when hot. This cuts down on manual work since you can just leave all that stuff behind once it’s done gluing.
Some parts need to be connected with thicker glass so they have an insert at the end. These gets melted onto the edge and bonded together while the rest is thinner and easily bent or shaped later.
Closing a bottle or putting a stopper in it also requires thinner glass but longer time to cool down and harden. So there are different types of equipment to achieve this depending on the product.
The process
All of glass comes from liquid, but it is not just any old liquid!
A common element in making most anything you can think of (with maybe the exception of water) is silica, or sand as some like to call it. This ingredient makes up about 40% of pure glass, with the rest being other elements such as potassium, sodium, magnesium, etc.
These minerals are mixed into the raw material (the fluid that becomes glass), frothing the mixture and incorporating those components. Once all of the ingredients are thoroughly mixed, the mix is melted down and shaped either by hand or machine.
From there, the glass is cooled and cut to size. It is then tempered, polished, and packaged for sale.
The finished product
After all of the steps are completed, what we have is an insulated glass unit or IGLU, as they’re often called. An IGLU is just like any other window frame except it does not contain wood. It instead has plastic that can be heated to make it soft so you can press in some metal wires to create your wire grid structure.
From there, another layer of tempered glass is attached using heat compression which makes it solid but still slightly bendable, similar to regular glass. This layer of glass is then cut into pieces to form individual panes for the IGUS.
The insulating material is now applied onto both layers of glass and mixed together by hand before being pressed into place. To ensure that no air gets trapped between the two layers, the whole process must take at least an hour per panel!
Products such as Fortalen are manufactured via this method and used in high quality windows and doors.
Popular misconceptions about glass
There are several popular myths surrounding glass that influence how it is made and what types of products can be done with it. Unfortunately, these wrong ideas often get spread through word of mouth or printed in material.
Many people assume that all glasses must be heated and bent using heavy equipment like a roller machine or a press. This assumption is false because there are ways to make almost every type of clear flat glass without having special machinery!
This article will talk more about some common theories about why glass is so beautiful and how they are not true. Then, we’ll discuss some easy recipes for making your own thin sheeted glassware.
Disclaimer: While this article may seem very academic and educational at times, we do not recommend attempting any glass projects unless you have trained yourself on proper safety procedures and materials.
Tips for taking good photos of your glass
The first thing you should do is learn how to use your camera properly!
Your smartphone already has a feature that can help when it comes to taking great pictures of glass, such as our new top 10 favorite picture frames here. It’s called live mode and it was designed specifically for this purpose.
In live mode, the device will try to stay in continuous autofocus while capturing still images or videos. This will remove the need to manually focus each time, which helps prevent blurry photos.
If one were to take their phone out during a lightning storm, then this is even better because the device will automatically switch off the flash so there are no weird reflections.
Recognize good glass
What makes up clear, transmissive glass is silica (or silicon oxide). This is also what gives most regular glasses their strength and durability.
The amount of silica in glass depends on how much pure quartz it contains. The more quartz, the higher its density and therefore heavier the glass. Therefore, thicker pieces of glass are made out of denser quartz batches and contain less air than thinner ones.
Thicker, heavier glass takes longer to melt down and shape-compared to thin, lighter glass. That’s why we usually see bigger, heavier shapes like bowls or jars that take longer to make than a tumbler, for example.
However, not every piece of thick glass is totally useless! A few types of heavy, strong glass have special qualities that make them useful in certain applications.
