How and from what glass and glass products are made. Glass: what is it, types, production technology, properties, purpose What is glass made from?

If you're wondering where glass comes from, go to the beach. Almost all glass is made from sand, which is actually ground quartz.

The sand contains a small amount of iron. It is iron that gives glass made from ordinary sand its greenish color. Glass wool uses selenium to produce absolutely colorless transparent glass. This mineral gives the glass a slight reddish tint, which is offset by a greenish color, resulting in the glass appearing colorless. (To produce glass of other colors, glassblowers add other substances: cobalt for deep blue; manganese for violet; chromium or iron for green.)

To make glass, sand must be melted. You've probably walked on hot sand on a sunny day, so you guess that to do this it needs to be heated to very high temperatures. An ice cube melts at a temperature of about 0 C. Sand begins to melt at a temperature of at least 1710 C, which is almost seven times higher than the maximum temperature of our usual oven. Heating any substance to such a temperature requires a lot of energy, and therefore money. For this reason, when producing glass for everyday needs, glassmakers add a substance to the sand that helps the sand melt at lower temperatures - about 815 C. This substance is usually soda ash.

However, if you use only a mixture of sand and soda ash when melting, you can get an amazing type of glass - glass that dissolves in water (frankly, not the best choice for glasses).

To prevent the glass from dissolving, you need to add a third substance. Glassmakers add crushed limestone to sand and soda (you've probably seen this beautiful white stone).

The glass commonly used to make windows, mirrors, glasses, bottles and light bulbs is called soda-lime silicate glass. This glass is very durable, and when molten it is easy to shape into the desired shape. In addition to sand, soda ash and limestone, this mixture (experts call it “mixture”) contains some magnesium oxide, aluminum oxide, boric acid, as well as substances that prevent the formation of air bubbles in this mixture.

All these ingredients are combined and the mixture is placed in a giant furnace (the largest of these furnaces can hold almost 1,110,000 kg of liquid glass).

The high heat of the oven heats the mixture until it begins to melt and changes from a solid to a viscous liquid. Liquid glass continues to be heated at high temperatures until all the bubbles and veins disappear from it, since the thing made from it must be absolutely transparent. When the glass mass becomes homogeneous and clean, reduce the heat and wait until the glass turns into a viscous viscous mass - like hot iris. The glass is then poured from the furnace into a casting machine where it is poured into molds and shaped.

However, when producing hollow objects such as bottles, the glass must be blown out like a balloon. Previously, glass blowing could be seen during fairs and carnivals, but now this process is often shown on TV. You've probably seen glassblowers blowing hot glass at the end of a tube to create amazing shapes. But glass can also be blown using machines. The basic principle of glassblowing is to blow into a glass droplet until an air bubble forms in the middle, which becomes a cavity in the finished piece.

After the glass is given the required shape, a new danger awaits it - it can crack when cooled to room temperature. To avoid this, craftsmen try to control the cooling process by subjecting the hardening glass to heat treatment. The last stage of processing is removing excess glass droplets from the handles of cups or polishing plates using special chemicals that make them perfectly smooth.

Scientists are still debating whether glass should be considered a solid or a very viscous (syrup-like) liquid. Because the glass in the windows of older houses is thicker at the bottom and thinner at the top, some claim that the glass drips over time. However, it can be argued that previously window glass was not made perfectly straight and people simply inserted them into the frames with the thicker edge down. Even glassware from the times of Ancient Rome does not show any signs of “fluidity”. Thus, the example of old window glass will not help resolve the question of whether glass is actually a highly viscous liquid.

People come into contact with glass products every day. Glass is an almost magical object - transparent on one side, and a material object on the other. A substance will be transparent when photons (light quanta) pass through it without being absorbed. But for some reason, not everyone comes up with the idea - how and what is glass made from? How does the process work?

Interesting Facts:

  • It will take a million years for glass to decompose.
  • Glass is recycled without loss of quality.
  • The thickest glass in the world is the 26 cm screen of the Sydney Aquarium.

What is glass made from?


To make glass, craftsmen take: quartz sand (the main component); lime; soda;

First, quartz sand, soda and lime are heated in a special furnace to a temperature of 1700 degrees above zero. The grains of sand connect with each other, then homogenize (turn into a homogeneous substance), and the gas is removed. The mass is “dipped” into molten tin at temperatures above 1000 degrees, which floats on the surface due to its lower density. The smaller the mass that goes into the tin bath, the thinner the glass that comes out will be.

Interesting Facts:

  • Murano glass is considered the most expensive in the world. Products made from it cost millions of dollars. Since ancient times, Venice has been famous for the production of high-quality glass. It is reliably known that in the 13th century the state government moved production to the large island of Murano, and the craftsmen were strictly forbidden to leave it. The punishment is a death sentence. In addition, entry to the island was also closed to tourists or other residents of Venice. Such strict measures made it possible to maintain the secret of production.
  • One of the most interesting mental illnesses of the Middle Ages is the “glass disease.” A person with such a disorder thought that he was made of glass and was afraid of breaking. The French king Charles VI suffered from this disease. The monarch always wore several layers of clothing and forbade anyone to touch himself.

What functions do soda and lime perform in the production process?


Baking soda helps reduce the melting point by 2 times. If you do not add it, it will be very difficult to melt the sand, and, accordingly, to connect individual grains of sand with each other. Lime is needed so that the mass can withstand water. If it had not been included, the window, for example, would have dissolved immediately after the first rain, and the glass would have burst after contact with water.

Related materials:

What is Venetian glass and why did artists buy eggs?

Interesting Facts:

  1. China did not produce glass for more than 500 years, from the 14th to the 19th centuries. Now the state is one of the leaders in production and controls a third of the world glass market.
  2. 1994 was a very active year for glass recycling in the United States. If you put all the glass products recycled during that year in one line, you will get a kind of “road” to the Moon.

How is colored glass made?

Not only colorless glass is produced. To obtain a colored product, in addition to the main components, chemical compounds are added to the melting furnace:

  1. Iron oxides give glass a rich red tint.
  2. Nickel oxides – brown, purple (depending on quantity).
  3. To get a bright yellow tint, add uranium oxides to sand, soda and lime.
  4. Chrome makes glass green.

What characteristics and properties does glass have?

The proportions of components for the manufacture of glass goods are selected depending on their purpose. They are distinguished: household glass - that which is then used to make dishes, glasses, jewelry; construction – shop windows, windows, stained glass;

What is it that you can’t do with your own hands nowadays? Be it an ordinary craft, a wardrobe item, furniture, etc. How to make glass at home? — It would seem like melting glass, it’s unrealistic. In the modern world, nothing is impossible. The main thing in this matter is desire. And in this article you will find a detailed step-by-step algorithm for such an entertaining and interesting activity as making glass.

What is known about glassmaking?

It is known from history that glassmaking is a very ancient process. How it's done? The time frame dates back to approximately the period before 2500 BC. Previously, such a rare and valuable occupation has now been replaced by the widespread production of this material.

Glass products are found everywhere. They are used as containers, household and decorative elements, insulators, reinforcing fiber and other things. Glasses differ only in the constituent material used for manufacturing. But the process itself is almost the same.

Basic materials you will need:

  1. the main element is quartz sand (silicon dioxide);
  2. sodium carbonate or soda;
  3. calcium oxide, also known as lime;
  4. furnace for melting glass;
  5. other salts and oxides that can be used additionally on an individual basis (oxides of aluminum, iron, magnesium, lead and calcium or sodium salts);
  6. protective clothing;
  7. grill;
  8. charcoal;
  9. molds and other elements for giving shape;
  10. fireproof crucible.

Methods for making glass using a furnace

The first way to solder glass at home is to use a stove.

Purchasing quartz sand:

  • This material is the basis for glass production. Glass, which does not contain iron impurities, has its advantages - it is light. The same cannot be said about the glass in which it is present. It will smell green.
  • It is important to put on a mask before starting work. Quartz sand is fine-grained and easily enters the nasal cavity and further into the lungs. This, in turn, will irritate your throat.
  • You can easily purchase quartz sand in a specialized online store. Its cost is low.

Important! The cost of the approximate quantity that will be needed will be around 20 USD. e. In the future, you can purchase up to a ton of it, the approximate cost of which will be 100 USD. e. This is if you plan to work on an industrial scale.

  • It happens that finding high-quality sand is not so easy, and it contains more impurities. Dont be upset. In this case, manganese dioxide will come to the rescue. It should be added in small quantities. If your idea is glass with a greenish tint, then you don’t need to do anything at all. Leave everything as it is.

Addition of calcium carbonate and oxide:

  • In this case, carbonate reduces the temperature of production of industrial glasses. At the same time, it causes corrosion of glass with the participation of water. To avoid this, it is necessary to additionally introduce lime or calcium oxide into the glass.
  • For glass resistance, magnesium or aluminum oxides are used. As a rule, these inclusions do not occupy a large percentage of the glass composition. The figure is approximately 26-30 percent.

Adding other chemical elements:

  • This method of making decorative glass at home requires the use of lead oxide. It gives shine to crystal, its low hardness, makes it easy to cut, and gives it a low temperature of melt formation.
  • Lanthanum oxide can be found in eyeglass lenses. It has refractive properties.
  • As for lead crystal, it can contain up to 33 percent lead oxide.

Important! The more lead, the more dexterity is required to shape the molten glass. Based on this, many glassblowers prefer a smaller amount.

  • Iron impurities in quartz glass give it a green tint. In this case, iron oxide is added to increase the greenish tint. This also applies to copper oxide.
  • Yellow, amber, and even black colors can be obtained using a sulfur compound. It all depends on the amount of carbon or iron added to the glass charge.

Main stages of glass production:

  • Place the mixture in a heat-resistant crucible. The latter should be as resistant as possible to the temperature that will be in the oven. It can vary from 1500 to 2500 degrees. It depends on the additives.

Important! There is also one important requirement for the crucible - it must be such that it can be easily fixed with metal tongs.

  • Melt the mixture to a liquid consistency. For industrial silicate glass, this can be done in a gas-heated furnace.

Important! There are also electric, muffle and pot furnaces. They can be made of special glass. Please note that quartz and sand, which do not contain additional impurities, turn into a glassy state when the oven temperature is 2500 degrees Celsius. If you add sodium carbonate to the contents, this is ordinary soda, the temperature will drop to 1500 degrees.

  • Carefully monitor the consistency of the glass. It is important to remove all bubbles from it in a timely manner. This can be achieved by stirring regularly until the consistency is uniform. It is also necessary to add one of the elements - sodium chloride, sodium sulfate or antimony oxide.
  • Shape the glass. To do this, use one of the following methods.
  • The simplest thing is to pour the glass melt into a mold and wait until it cools. Using this method, many optical lenses are created. Previously, this was the method used by the Egyptians.
  • Place the finished molten glass in a bath containing molten tin. The latter acts as a substrate. Next, you need to blow it with compressed nitrogen to shape or polish it. Another way is to collect the required amount of glass at the end of a hollow pipe and, turning the pipe, blow it out.

Important! Glass made using this method is called float glass. This is what they have been producing since the early 1950s.

  • Leave the glass to cool. It is important to place it in a place where it will not be damaged, it will not be spoiled by water, dust or, for example, leaves. Keep in mind that if it comes into contact with cold objects, it will crack.
  • The final step of this method of making glass at home will be annealing the glass. This method of heat treatment will add strength to the material. When using it, all point sources of stress that may be encountered during the glass cooling process will be removed.

Important! Upon completion of this work, additional coatings can be applied to the glass to increase durability and strength. Can also be laminated.

  1. Unannealed glass has less strength.
  2. As for the temperature for finishing work, it depends on the exact composition of the glass - from 400 to 550 degrees Celsius.
  3. The cooling rate of glass depends on the size. Large glass items must be cooled slowly. Things go faster with smaller ones.

Method of making glass using a roaster

The second way to make glass at home is with a charcoal roaster. Let’s look at everything step by step in this case too.

Equipment for work

First you need to make a stove. A barbecue grill is perfect for this. It is important that it is heated with charcoal. In this case, the heat generated by coal when burned is used to melt quartz sand into glass. Again, the cost of this material is not too high. They are widely available.

Important! Use a standard size grill. It would be better if it was in the form of a dome. The main qualities that it must have are the presence of thick walls and good strength. If your grill has a vent, usually on the bottom, it needs to be opened.

However, there may be some minor hurdles in this method. Even if there are very high temperature numbers, it is not always possible to melt it easily. To do this, before starting the process, you need to add lime, borax or washing soda to the sand. The amount of additives should not exceed ⅓-¼ of the volume of sand.

Important! Remember that these additives significantly reduce the melting point of sand.

Formatting glass

To blow glass, prepare a long, hollow metal tube. In order to pour glass, you need a mold. It should be dense and should not melt from the hot glass. Use graphite, for example.

Important! When using this method, remember that the grill heats up much higher than normal. It is possible that the grill itself may melt. Therefore, when making glass using this method, you need to perform all actions carefully and responsibly. Negligence can result in serious injury or even death.

Security measures:

  1. Place a large amount of sand and a fire extinguisher near the work area.
  2. All work must be done outdoors.
  3. The floor should be concrete, for example.
  4. When cooking glass, stay away from the grill in order to protect yourself and your clothes from high temperatures.
  5. Don't forget to wear protective clothing. This includes fire-resistant clothing, oven mitts, a high-strength apron over clothing, and always a welding mask.
  6. Also in this method you will need a vacuum cleaner. It will act as a coal blower. We position it as follows: we place the body at a sufficient distance. We fix the hose to the ventilation hole, which is located below. It may need to be bent to get the desired shape. You can fix it to one of the grill legs. The hose must be secured firmly and not move.

Important! If the opposite happens, then under no circumstances approach it, because it is very hot. Next, you need to turn off the vacuum cleaner and look at the position of the hose. It should be aimed exactly at the ventilation hole.

Operating procedure:

  • Place charcoal on the inside of the grill. It is necessary to put in two or even three times more than for roasting meat. It's good if it's filled almost to the brim.

Important! Use hardwood charcoal. It burns faster and better than briquetted.

  • Place a cast iron container or crucible with sand in the middle of the bowl.
  • Carefully examine the packaging of the charcoal you use. Light it in a suitable manner. There is coal that lights itself directly, and there is material for which lighter fluid is used. Wait until the flame spreads evenly.
  • Wait until the coal is ready for further work. The readiness of coals can be determined by color. They will be orange.
  • The next step is to turn on the vacuum cleaner. This is necessary to ensure that the coal is blown through.

Important! Coal exposed to air flow can reach very high temperatures. Up to approximately 1100 degrees Celsius. This must be taken into account when near the stove. Rising flashes may appear from it.

  • If the temperature has not reached the desired figure, then you need to check the location of the hose in the ventilation hole.
  • Everything necessary to melt the sand has already been done. The final step is to remove the glass container from the grill. Here you also need to be very careful. Use a long metal tool.
  • Next, carry out all your ideas with glass.

Important! Keep in mind that glass made using this method will be thicker. It will be a little harder to work with. This is all due to the low temperatures during its manufacture.

Finally, we offer you a few more tips on making glass at home:

  • Beach sand can be used instead of special quartz sand. It should be the whitest, most uniform and thin. However, the quality of such glass will not always be necessary.

    • We have given two ways to craft glass yourself. The same method can be used to make sea glass at home. When performing work, be extremely careful so that it does not result in disastrous consequences for your health.

Using glass objects every day, almost no one thinks about what this material is obtained from. How are sometimes amazingly beautiful interior items made? How is glass made? Why does sunlight penetrate freely through a window into a room? How do certain types of glass avoid breaking even when subjected to strong impacts?

Production technology

The main material for glass production is quartz sand. Yes, the same one that is strewn with sandy beaches and on which you can happily walk barefoot in the summer.

Glass production begins with the precise amount of tiny quartz measured on an electronic scale being heated to a temperature of over 1500 degrees C. The grains of sand melt, forming a homogeneous mass. Soda ash and limestone are added to them in small quantities. For what purpose?

Soda ash acts as a catalyst in this process and causes the sand to melt at a lower temperature, approximately 850 degrees C. This reduces energy costs for production. But soda is not used without limestone. This fact is explained simply: molten sand and soda ash, when solidified, form a substance that easily dissolves in water (not the best material for the production of household items). Magnesium and aluminum oxides and boric acid are also added here. As well as a number of substances that prevent the formation of air bubbles in the mass.

After all the components are brought to a certain temperature, sharp cooling follows - this will prevent the grains of sand from returning to their original form.

glass rainbow

Crushed quartz (sand) in its natural form contains a small admixture of iron, which gives finished products in the future a light green tint. To make the material transparent, selenium is added to it. This substance gives off reddish tones, but when mixed with iron, the glass surface turns out colorless. And what is glass made from in different shades, and sometimes not even one color, shimmering with all the colors of the rainbow?

To give the material color, metal oxides are added to the heated mixture. Cobalt will give rich blue colors. The product will sparkle with purple shades if manganese is added during the manufacturing process, and green will come from a mixture of chromium and iron. For sunny yellow color, chromium oxide is suitable, for emerald green - chromium and copper oxides. Which components are added depends on the purpose of the glass plant.

The secret of strength

The next process after coloring is crystallization of the mixture. It is otherwise called the homogenizing process. As a result, all air bubbles, streaks and other inconsistencies that may further affect the quality of the products are removed.

After homogenization, the future glass is delivered to a tank with molten tin at a temperature of about 1000 degrees C. Since tin has a higher density, the liquid glass mass is on its surface. Where it becomes perfectly smooth, it cools a little, acquiring hardness. At the next stage, the mass, cooled in the tank to 600 degrees C, is transferred to a roller conveyor. Here, based on the rules of how glass is made with a high level of quality, it is kept until the temperature drops to 250 degrees C. The duration of the process is explained by the need for uniform gradual cooling, in order to avoid premature cracks.

Unique waste-free production

At the end of the conveyor, a device is installed that controls the quality of the finished material, and if there is the slightest flaw, the glass is sent for remelting with a new prepared mixture. After passing quality control, the finished sheets are cut into the required format and sent either to the warehouse or for further processing. It all depends on the purpose of the product.

The remains after cutting are put back into the mixture for remelting. All rejected material is sent there. Based on how glass is made, we can say with confidence that this production is waste-free.

Kinds

Due to its chemical and physical properties, glass is divided according to several criteria:

  • by purpose (domestic needs, industrial use, construction);
  • by type of processing (chemical, mechanical and special technologies);
  • by surface texture (matte, glossy, coated with various metals, with or without film coating).

There is no clear division into categories. The classification is based on the technology used and how the glass is made. The end result may be a multi-layer surface with machined edges or a product with a high level of light transmission, cold cut. It is worth noting that a separate quality parameter is the level of light transmission. There is no glass with a 100% level; for domestic needs it is 82%. In high-tech products: microscopes, telescopes, various lenses and precision instruments - this figure is above 90%.

People come into contact with glass products every day. Glass is an almost magical object - transparent on one side, and a material object on the other. A substance will be transparent when photons (light quanta) pass through it without being absorbed. But for some reason, not everyone comes up with the idea - how and what is glass made from? How does the process work?

Interesting Facts:

  • It will take a million years for glass to decompose.
  • Glass is recycled without loss of quality.
  • The thickest glass in the world is the 26 cm screen of the Sydney Aquarium.

What is glass made from?


To make glass, craftsmen take: quartz sand (the main component); lime; soda;

First, quartz sand, soda and lime are heated in a special furnace to a temperature of 1700 degrees above zero. The grains of sand connect with each other, then homogenize (turn into a homogeneous substance), and the gas is removed. The mass is “dipped” into molten tin at temperatures above 1000 degrees, which floats on the surface due to its lower density. The smaller the mass that goes into the tin bath, the thinner the glass that comes out will be.

Interesting Facts:

  • Murano glass is considered the most expensive in the world. Products made from it cost millions of dollars. Since ancient times, Venice has been famous for the production of high-quality glass. It is reliably known that in the 13th century the state government moved production to the large island of Murano, and the craftsmen were strictly forbidden to leave it. The punishment is a death sentence. In addition, entry to the island was also closed to tourists or other residents of Venice. Such strict measures made it possible to maintain the secret of production.
  • One of the most interesting mental illnesses of the Middle Ages is the “glass disease.” A person with such a disorder thought that he was made of glass and was afraid of breaking. The French king Charles VI suffered from this disease. The monarch always wore several layers of clothing and forbade anyone to touch himself.

What functions do soda and lime perform in the production process?


Baking soda helps reduce the melting point by 2 times. If you do not add it, it will be very difficult to melt the sand, and, accordingly, to connect individual grains of sand with each other. Lime is needed so that the mass can withstand water. If it had not been included, the window, for example, would have dissolved immediately after the first rain, and the glass would have burst after contact with water.

Related materials:

What is Venetian glass and why did artists buy eggs?

Interesting Facts:

  1. China did not produce glass for more than 500 years, from the 14th to the 19th centuries. Now the state is one of the leaders in production and controls a third of the world glass market.
  2. 1994 was a very active year for glass recycling in the United States. If you put all the glass products recycled during that year in one line, you will get a kind of “road” to the Moon.

How is colored glass made?

Not only colorless glass is produced. To obtain a colored product, in addition to the main components, chemical compounds are added to the melting furnace:

  1. Iron oxides give glass a rich red tint.
  2. Nickel oxides – brown, purple (depending on quantity).
  3. To get a bright yellow tint, add uranium oxides to sand, soda and lime.
  4. Chrome makes glass green.

What characteristics and properties does glass have?

The proportions of components for the manufacture of glass goods are selected depending on their purpose. They are distinguished: household glass - that which is then used to make dishes, glasses, jewelry; construction – shop windows, windows, stained glass;

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