How window glass is made. How glass is made: production features. Glass at home

WHAT IS THE ARTICLE ABOUT?

Glass composition

The components that make up glass can be divided into the following types:

• The basis
• Mandatory Alkali Metal Oxides
• Components that give special properties
• Excipients

Also in some cases, cullet is added.

The basis of any glass is quartz sand or silicon dioxide. Moreover, only selected sand, purified from iron impurities and from the slightest contaminants, gets into the mixture for future glass, about 2% of impurities are allowed. The transparency of the glass itself depends on this.

The required alkali metal oxides are different depending on the type of glass. For example:

• for window glass, oxides of sodium, calcium or aluminum are used
• for crystal - oxides of potassium and lead
• for laboratory - oxides of sodium, potassium, boron
• for optical - oxides of barium, aluminum, boron

Components to impart special properties are selected based on the desired effect, for example, titanium or barium oxides are added to impart heat resistance, and so on.

Auxiliary substances are mostly illuminators, bleaches and dyes.

Industrial glass production

It all starts with the fact that all the necessary substances are brought to the production plant. The main components of what glass is made of are quartz sand, dolomite, soda, lime. All substances undergo preparatory processing. Sand is cleaned of iron impurities, dolomite and lime are crushed in a crusher. After that, all substances are mixed and at this stage the components necessary to impart certain properties are also mixed in. This whole mixture is called a mixture. A mixture is a mixture that is already completely ready for further processing, that is, it is already exactly what glass is made of.

The technological process for the manufacture of glass begins. The finished charge goes through the conveyor into the bunkers, from which it is poured into the loader, and the loader already pushes it into the furnace. Since the temperature here ranges from 1200 to 1600 degrees, depending on the type of future glass, such a furnace operates continuously for several years. Because you can’t just take and turn off such a furnace, otherwise it will simply collapse. In order to turn off such an oven, it will take about a week of uniform cooling. At this temperature, the charge turns into glass mass.

From the furnace, this glass mass first enters a tank with a stirrer, and after it is well mixed, it flows into the stubbing chamber. Here it cools down to about 1000 degrees. From the student part, the glass melt enters the fleet bath. At this stage, an interesting process occurs. A navy bath is a bath of molten tin, the temperature of which is about 600-700 degrees Celsius. On this tin, the glass mass literally floats and cools down a little, it is thanks to this technology that it acquires an almost perfect plane.

After a bath with tin, the glass ribbon enters the firing lehr, which is more than 100 meters long, rolling over which it gradually cools.

The next step is cutting the tape into sheets of glass. This is where some very clever technology comes into play. Cutting takes place directly in the direction of the tape, which significantly speeds up the entire process of glass production. How can you cut the tape on the go, you ask. The fact is that the cutter moves at exactly the same speed as the tape and at this time cuts it across, after which it returns to its original position. So we get finished sheets of glass.

Now, such equipment as a stacker machine comes into operation. As the name suggests, she makes stacks of glass. The movement of glass sheets occurs with the help of suction cups, since the glass is very fragile, but it weighs quite a lot, it cannot be moved in any other way. After the stacks are formed, they are transported by a special loader, and then the glass is distributed to warehouses, shops, to places where double-glazed windows are made from them, and so on.

By the way, why is glass transparent? The fact is that quartz sand is completely transparent. But we cannot see anything through the grains of sand due to the multiple refraction of light. For example, if you break the glass into many pieces, then you will not see anything through them either. And when the sand turns into a smooth mass, then here we already see a transparent sheet of glass.

Manufacturing of glass products

Glass products can be divided into two large types. The first are those products that are produced on an industrial scale, the so-called glass containers, such as glass bottles, jars. The second big type is art products. This is the name of all products that are made by hand by glassblowers, such as vases, glass figurines, figurines and the like. In the manufacture of glass products, industrial glass and in general any glass, the initial stage of production is always absolutely similar, until the glass mass is obtained. Only the components that make up the charge, the melting temperature and the subsequent processing of the resulting glass mass are different.

Manufacture of industrial glass products

The finished glass mass from the furnace falls into a glass line, from which it flows out in the form of a sausage and is cut into cylindrical drops by a cutter, one such drop is a future bottle or jar. The drop is sent to a so-called scoop, which directs them to the molding machine. It works by the following method: the holders take the drop by the edge and hold it in a hanging position, the entire lower part of the drop is closed on both sides with the desired shape, whether it be a jar or a bottle, certain patterns can also be on the shape. After the mold is closed, the holder is removed and a blowing device is inserted into the drop. It, like a balloon, inflates the drop from the inside with compressed air and the mass acquires the desired shape. Excess molten glass goes back to its original shape.

By the way, to give the glass some color or shade, certain substances are added to the charge, for example, iron or chromium oxide is added to give green color, copper oxide for blue, and so on.

Now almost finished products move along a heated conveyor so that there is no sharp temperature drop and the product does not crack. From this conveyor, the loading machine moves the products into a lehr, along which they move slowly and gradually cool down. Here they are treated with a special solution that allows them to glide and move smoothly. And they move on to the testing and packaging line. After going through all the stages, we get ready product.

How art glass products are made

Artistic glass products are all made from the same glass mass. In the production of such products, the same furnace is still used, but only the temperature for manufacturing is slightly lower than industrial, about 1200 degrees. The product itself is made by glassblowers. Glassblowers are like jewelers for glass, they can work alone or in pairs or even more.

With the help of a long tube, glassmakers take the required amount of hot glass directly from the furnace and immediately begin to shape it with various methods, while periodically blowing it through the tube. In the process, it will be possible to add more material, for example, for any additional details. Very small details are made separately, also by different methods.

After forming the details and the general shape of the product, it is placed in another kiln for a day. As a rule, the temperature in the heated state is about 400 degrees, at night such a furnace is turned off and the products in it gradually cool down to 70 degrees, where they harden and harden.

31.10.2017 19:01 2116

Glass is an indispensable item in our lives. It is found everywhere: in residential buildings, shop windows and in all modes of transport.

Have you ever wondered what glass is made of?

People learned how to make glass in ancient Egypt about 5 thousand years ago, but unlike modern glass, it was not as transparent as it is now.

The main material for making glass is quartz sand. Lime and soda are added to it and heated in a special oven. Due to the interaction with soda, sand melts better. Lime also serves to strengthen the resulting material, and it does not collapse when interacting with water. If lime were not added, then the glass could simply dissolve on contact with water. When the temperature reaches 1700 degrees, all three materials mix and become one substance, which is lowered into molten tin at a temperature of more than 1000 degrees. Next, the resulting material is placed on a conveyor, where it is cooled to 250 degrees. In the same place, the glass is cut into standard parts and adjustable in thickness.

To obtain colored glass, in addition to soda and lime, compounds of chemical elements are added to sand. For example, green glass can be obtained by adding chromium, yellow by adding uranium oxide, and red by iron oxide. An oxide is a compound of a chemical element (for example, a metal) with oxygen.

Various forms of glass are obtained by blowing its red-hot mass. There is such a profession - a glass blower. This is a craftsman who makes glass of various shapes. The glassblower uses a special long tube in his work.

On its tip, he catches molten glass and blows out the resulting bubble. In this case, the glassblower rotates the tube, and the bubble enters a special wooden or metal mold. Sometimes masters make their masterpieces without forms. They process the bubble blown out of the tube with the help of tools (forceps, scissors, trowels, etc.), giving it various shapes.

In the last 10 years, glass industry products have been in high demand. Souvenir products, furniture, window and door components, dishes, various containers, etc. are made from glass. However, in order for the manufactured goods to find their consumer, it is necessary to correctly select the production technology and control the accuracy of its execution at all stages of the process. Another nuance is significant capital investments at the start, amounting to more than 100 million rubles only for the purchase of equipment. For this reason, many entrepreneurs are abandoning full-scale glass production in favor of recycling the material, which is also profitable, but less costly to initial stage field of activity.

Features of the Russian market

The leaders of the glass industry of the Russian Federation are 11 plants, the largest of which are: JSC "AGC BSZ" (Nizhny Novgorod region), JSC "Saratovstroysteklo" (Saratov region), JSC "Salavatsteklo" (Bashkortostan), LLC "AGC Flat Glass Clean" ”, Pilkington Glass LLC (Moscow region). It is these enterprises that produce 90% of domestic sheet glass. Moreover, only 30% of the volume of glass products on the market comes from abroad.

Glass production consumes 21% of raw materials, about 8% of fuel, 13% of electricity from the total industrial volume of the Russian Federation.

Glass types

Depending on the industry that the company is going to serve, it is possible to set up the production of various types of glass. Among the most requested modifications:

• quartz glass. The most common and easy to manufacture type of material based on quartz sand. Products made from it have heat resistance, transparency, but at the same time they are quite fragile. Such glass is used, for example, for the manufacture of flasks and other laboratory glassware.
• lime. An inexpensive material to manufacture, which is used for the manufacture of glass containers, sheet glass and electric lamps.
• Lead. Silica and lead oxide are added to the composition of the glass mass. It is used in the production of crystal and elements of radio components.
• Colored glass. It can be body dyed, drawn, rolled, patterned, smooth and two-layer. It is used as a facing material, for decorative glazing, making stained-glass windows.
• energy saving(K-, I-, E-, I-glass). It is produced by applying a thin, invisible coating with high thermal conductivity to the glass surface. Thanks to this, about 70% of the heat coming from heating devices is retained in the room.
• Reinforced glass. Used for glazing window structures and partitions in industrial premises. In the thickness of the glass there is a metal mesh, thanks to which, in case of fire or mechanical damage, the structure does not shatter into fragments, but breaks off along the cut line.
• tinted. Used for sun protection. It is produced by adding metal oxides of a given shade to the glass mass.
• sun protection glass. The appropriate coating is applied by spraying. Penetrating into the thickness of the glass, metal oxides give the surface additional strength and resistance to external influences.
• Strained glass. The material is obtained by heat treatment. After gradual heating and subsequent cooling, the glass acquires mechanical strength, which allows it to be used, for example, in the automotive industry.
• multilayer (Triplex). Contains several layers glued together with transparent polymers. It has a high resistance to the formation of through holes, good sound insulation, does not shatter into fragments upon impact. It is used most often as a windshield in cars and in the production of double-glazed windows.
• Milled. Ordinary glass is heated and given a given shape. As a result, a wide variety of products of a complex, for example, curved, configuration are obtained.
• Armored. Multi-layer construction of several M1 glasses and polymeric photocurable composition. It can be film and filmless. Reliably protects against bullets in accordance with the bullet resistance class - B1, B2, B3, B4, B5.
• fireproof glass. Little is produced in Russia. Contains reinforcement that holds glass cracked in a fire in place, thereby preventing the spread of flames.

Glass production equipment

Scroll

The choice of equipment depends on the type of product being produced. In this case, the manufacturer practically does not play a role. Domestic units are not inferior in quality foreign analogues. All standard lines have the same set of components:

• Units for the preparation of raw materials. These include machines for separating impurities, in particular magnetic separators that extract metal particles from sand, as well as powerful crushers for grinding ingredients.
• Plants for batch mixing (charge mixers). Components are selected depending on the composition of the final product.
• Weighing equipment. High-precision scales allow you to dose the components correctly.
• Glass melting plants.
• Conveyor equipment. Necessary for transporting ingredients.

You will also need a packaging line and possibly a sandblasting machine.

Equipment for the production of various kinds glass looks quite similar. Installations for the manufacture of automotive glass are considered to be one of the most complex, due to the strict standardization of the final product. There are specific cooling lines, gluing machines, as well as devices for processing products with polymers, which give the surface additional strength.

Glass furnaces

For melting glass, special furnaces with different technological modes are used. This equipment is classified according to two indicators.

Classification by technological parameters

In small enterprises for the production of optical, lighting and medical glass, pot furnaces are used. The equipment is designed to produce a small amount of products (1-16 pots are installed in the oven) with high light transmission and uniformity.

Also in the glass industry, bath furnaces of continuous or batch action are often used, having the form of massive rectangular containers. Their design and dimensions may vary. The lines include installations with molten tin, where the glass mass is cooled.

Large-sized bath furnaces are equipped with complexes for automatic control of the burners, which allows you to regulate and evenly distribute pressure, temperature and gas component on the working surface.

Classification according to the principle of heating

According to the principle of heating, plasma and electric furnaces are distinguished. The former work from fuel combustion and have low efficiency, since thermal energy used to heat the charge and boilers.

Electrical equipment makes it possible to produce all existing species glass. Here, glass mass acts as a heating element, which, under the influence of high temperatures, acquires the properties of an electrolyte. The main advantage of the installations is the absence of heat losses with outgoing gases.

There are also combined gas-electric furnaces, where gas heating is used to melt the charge, and the glass mass is heated by means of direct resistance.

What is glass made from?

In accordance with the classical technology, the main raw materials in the production of glass are quartz sand, sodium sulfate, dolomite and limestone. To speed up production processes, the so-called charge is used - specific oxides that promote glass formation. They can be basic or acidic. To give the glass the desired properties, auxiliary “ingredients” are used - manganese, chromium and cobalt dyes, brighteners (saltpeter, arsenic trioxide), etc.

The basic components of the glass mixture are sand (70%), soda and lime (30%). After adding other substances according to technological process, the mass is mixed, melted, cooled and cut into sheets of a given size. Modern production lines are designed for the production of sheet glass with a thickness of 2-50 mm and a size of 5x3 m².

Glass production technology + Video how they do it

Its production is a labor-intensive and painstaking process that requires professional knowledge of technology and large investments. The classical method of glass production is based on the melting of the initial mass, where decolorizers, silencing agents, dyes, amplifiers, etc. are additionally introduced. Then the composition is cooled and cut, based on the specified parameters. At the moment, 2 glass production technologies are popular in the world.

Emil Furko method

The technology is based on vertical machine drawing of the material. The glass mass is melted in a glass melting furnace and drawn out by means of rolling shafts, and then fed into the cooling shaft and cut. Almost finished sheets are subjected to grinding and polishing. The thickness of the products is regulated by changing the drawing speed.

Float method [main]

The technology assumes that the molten glass mass from the furnace is placed on horizontal pallets and fed into a float bath with molten tin and a gas-air atmosphere. Moving along the surface, the future glass acquires flat shape and is saturated with tin particles. The sheets are then cooled and annealed. The main advantages of the method are high productivity and no need for subsequent processing (grinding, polishing). In addition, this glass has:

• correct geometry, the same thickness throughout the sheet;
• high quality;
• transparency;
• excellent optical properties.

In a similar way, reinforced glass with figured cells is made.

Full video about the whole process of how they do it, including sand preparation:

Additional processing

IN this case we are talking about applying coatings to the side of the glass that did not come into contact with molten tin. The technology finds application in creating non-standard design solutions.

Due to the high cost of equipment and the high complexity of the production process, many entrepreneurs prefer the secondary business of glass processing or the manufacture of certain products - souvenirs, mirrors, glass furniture, double-glazed windows, and various decorative products.

Mirror production technology

The mirror surface is obtained by decorative processing of sheet glass. Along the edge of the workpiece, facets are made with a width of 4-30 mm and an angle of inclination to the front surface of 5-30°.

Then, a reflective layer of silver 0.15-0.3 µm thick is applied to the back side and coated with a copper-based film for electrochemical protection of the silver layer. The process is completed by applying paints and varnishes that prevent mechanical damage to the surface. Epoxy enamels, polyvinyl butyral and nitroepoxy compositions can be used as them.

Another way to manufacture mirrors is glass metallization by vacuum evaporation and cathode sputtering.

Colored glass production technology + Video

By appearance and, accordingly, manufacturing technologies distinguish several types of sheet glass: drawn, patterned, smooth, colored in mass, two-layer, made by applying oxide films of a given color.

The basic composition of the material is similar to that used for the manufacture of window sheet glass. Molecular dyes are most often used for staining. Products of red, blue, green, violet, blue, milky white, yellow, orange and black colors are in the greatest demand.

According to the type of staining, glass can be transparent, muted or marble-like. In the latter case, the effect is achieved by incomplete mixing of the colored glass mass with opaque glass.

Metal oxides, sulfur compounds of iron, lead, cadmium and copper, as well as sulfur and selenium act as dyes. The intensity of the color depends both on the chosen dye and on the properties of the glass itself. By experimenting with several pigments, it is possible to get dozens of color options.

The differences between the production technology of colored glass and the production of ordinary sheet glass lie in the specifics of the melting and molding processes. So, during cooking, it is necessary to pay special attention to the observance of temperature and gas conditions, the algorithm for supplying charge in the furnace and return cullet. A number of coloring components evaporate when heated, respectively, even small deviations from the technology can cause substandard.

Due to the significant difference in the heat transfer of the outer and inner layers, the former harden faster when cooled. Thus, the thinner the tape, the more evenly it cools. That is why the vertical boat drawing method is not used for the production of thickened sheet glass.

The melting of colored glass is carried out in glass melting furnaces with a capacity of 2-15 tons per day with a pool of shallow depth (300-700 mm). The cooking mode is set according to the type and composition of the glass, as well as the properties of the additives used. Some time ago, the melting of colored glasses began to be carried out in direct heating furnaces without recuperators and regenerators.

Requirements for production facilities

Today, glass production with a capacity of about 600 or more tons of products per day is considered the most profitable. Accordingly, the location of the plant should be selected taking into account the presence of nearby deposits of quartz sand and glass batch components, places of compact residence of the population and road, including railway interchanges.

Technological cycle allows the entry of railway tracks into the territory of the enterprise; accordingly, the presence of open combustible structures, coatings and ceilings in the structures should be excluded, and the width of the access roads should be sufficient for the supply of fire engines.

Buildings where glass production is carried out directly belong to category D in terms of fire safety, the rest of the buildings - to category D.

According to the current sanitary standards, glass production belongs to class III and must be separated by a 300 m wide sanitary protection zone. Also, a wastewater filtration system and air filters must be installed at the enterprise.

Each building at the enterprise must be connected to water supply, sewerage, power supply, heat supply, gas supply, flow ventilation.

The type and number of storeys of structures depend on the composition, type, quantity and dimensions production equipment. As a rule, we are talking about one-story multi-span buildings with a grid of columns 30x12 and 36x12 m, 14.4 and 16.5 m high. The frame of the buildings is made of prefabricated reinforced concrete or steel supporting structures.

Trends in the development of glass production

Modern glass production is developing in three main areas: improving working conditions, automating processes and focusing on the production of "green" products.

To solve the tasks set, new technologies are being developed and introduced, including advanced developments in the IT industry, active modernization of existing production facilities, special programs are being introduced that provide for a reduction in the working day, employee insurance, and the installation of efficient ventilation equipment.

Companies strive to compensate for the harm caused to the environment in the process of glass melting through the active use of recycled materials.

The names and faces of those worthy people who gave the world glass, history, as usual, did not bother to save. Actually, there is nothing surprising in this: according to the Roman historian Pliny the Elder, the Phoenician sailors were the discoverers. Moreover, the discovery, like most of his kind, was made by accident.

If we ignore the high style and ancient Latin in which Pliny's "Natural History" was written, the story is as follows. One day, a Phoenician merchant ship, caught in a strong storm, was forced to anchor in a small bay. Tired and chilled sailors went ashore. They began to look for a place to make a fire in order to cook their own stew and keep warm. The shore was sandy, and there were no stones to be seen anywhere on which to put a cauldron. Then it occurred to one of the sailors to pull out of the ship's hold blocks of soda, which were being transported for sale, and put a boiler on these blocks.

So, it was on these soda blocks that the Phoenician sailors put a cauldron of water. The fire turned out to be extremely successful. The sailors had a hearty meal and went to bed. In the morning, getting ready to go, one of them scattered the smoldering remains of a fire. Suddenly he noticed some shiny pieces in the ashes. They didn't look like wood, or metal, or clay, or stone. Until then, no Phoenician had seen such strange light pieces. This new mysterious substance - according to Pliny - was glass: an alloy of coastal sand with soda.

This story is likely to be remembered by everyone who read a history textbook in school. For some reason, this version is loved by many to this day. But how plausible is it? Alas, modern glass makers have quite convincingly proved that the ancient historian was mistaken. Or misrepresented something. But the fact remains: it is impossible to weld glass from soda and sand in a fire flame.

More realistic seems to be the assumption that, by chance, a mixture of sand and soda fell on a clay pot before firing. And the potter, who took the finished product out of the oven, noticed a thin shiny film that covered the sides of the vessel.

In general, one can only guess about who was lucky with the discovery of glass and either believe the stories about the Phoenician sailors, who were generally wonderful guys, or support the version of the lucky and attentive potter. Those who study the history of the origin of this material will someday come to a consensus regarding the place - Egypt, Phenicia or Mesopotamia, Africa or the Eastern Mediterranean, etc. - and regarding the time - "about 6 thousand years ago", but the characteristic "synchronism of discoveries » can be observed, and even a difference of hundreds of years does not matter much, especially when significant differences can be traced in the reconstructed method of melting glass.

Glass manufacturing technology

Who do you think is ahead of the rest in the field of ancient glassmaking? That's right - the ancient Egyptians. Until about 4 thousand BC. ancient egyptians the so-called "Egyptian faience" was brewed from steatite, soft quartz flour or whole natural quartz.

There is an opinion that the earliest samples are made of steatite. The composition of this mineral is magnesium silicate, it is present in nature in large quantities. Products cut from a piece of steatite were coated with a powder mixture of raw materials that make up the glaze and fired. This glaze, which in chemical composition is sodium silicate with a small admixture of calcium, is nothing more than fusible glass, painted in blue and greenish-blue tones with copper, sometimes with a fair amount of iron.

Egyptian glassmakers melted glass on open hearths in earthenware bowls. The sintered pieces were thrown hot into the water, where they cracked. The resulting fragments, the so-called frits, were ground to dust with millstones and melted again.

Fritting was used as the main glass-making technology even after the end of the Middle Ages, so in old engravings and archaeological excavations we always find two furnaces - one for pre-melting and the other for melting frits.

The required penetration temperature is 1450 °C and working temperature- 1100-1200 °C. The medieval melting furnace (“gut” - in Czech) was a low arch, heated by firewood, where glass was melted in clay pots. Laid out only from stones and alumina, it could not stand it for a long time, but for a long time there was not enough firewood. Therefore, when the forest around the guta was cut down, it was transferred to a new place where there was still plenty of forest.

Another furnace, usually connected to a smelter, was an annealing furnace - for tempering, where the finished product was heated almost to the point of glass softening, and then cooled rapidly to compensate for the stresses in the glass (prevent crystallization).

In the form of such a design, the glass furnace lasted until the end of the 17th century, however, the lack of firewood forced some Huts, especially in England, to switch to coal already in the 17th century. With the change of fuel, another inconvenience arose: the sulfur dioxide escaping from the coal stained the glass yellow. To avoid this, the British began to melt glass in the so-called covered pots.

Interesting information is that glass, in a general sense, has not undergone practically any changes during its existence (the earliest samples of what they began to call glass do not differ in any way from the bottle known to everyone), but in this case we are talking about a substance and material of mineral origin, which has found application in modern practice.

Glass composition

Pure silica (SiO2) has a melting point of approximately 2000 degrees and is mainly used to make glass for specialty instruments. Usually, two more substances are added to the mixture to simplify the production process. Firstly, it is sodium carbonate (Na2CO3), or potassium carbonate, which lowers the melting point of the mixture to 1000 degrees. However, these components contribute to the dissolution of glass in water, which is highly undesirable. Therefore, another component is added to the composition of the mixture - lime (calcium oxide, CaO) to make the composition insoluble. This glass contains about 70% silica and is called soda-lime glass. The share of such glass in the total production is approximately 90%.

Just like lime and sodium carbonate, other ingredients are added to ordinary glass to change it. physical properties. The addition of lead to glass increases the refractive index of light, significantly increases the brilliance, and the addition of boron to the composition of the mixture changes the thermal and electrical properties of the glass. Thorium oxide gave glass a high refractive index and low dispersion, which is necessary in the manufacture of high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern products. Iron additives in glass are used to absorb infrared radiation (heat).

Metals and their oxides are added to glass to change its color. For example, manganese is added in small amounts to give the glass a green tint, or at more high concentrations- the color of amethyst. Like manganese, selenium is used in small doses to discolor glass, or in high concentrations to impart a reddish color. Small concentrations of cobalt give the glass a bluish tint. Copper oxide gives turquoise light. Nickel, depending on the concentration.

In addition to ordinary glass, there are several varieties of historical, cultural and artistic value. For example, Czech and Murano glass. But about them - in the following materials. Follow the news.

Faced with glass products every day, few of us think - what is glass made of? How is the production process going? Appearing in ancient Egypt 5 thousand years ago, the glass was very cloudy, and had an unattractive appearance. The material with which we are now confronted was obtained much later.

glass composition.

Pure glass is used for glass quartz sand(about 75%), lime And soda. To obtain a product with specific properties, oxides and metals can be included in the composition.

• Boric acid oxide. Reduces the coefficient of thermal expansion of the resulting products, and increases the gloss and transparency of the finished products.
• Lead. This component is added during the production of crystal. Crystal products are colder to the touch and have a characteristic luster and ringing for this material.
• Manganese. The addition of this heavy metal contributes to the production of products with a green tint. In addition to manganese, with the help of nickel, chromium or colt, you can get products of other colors.

physical properties.

The most important characteristics of glass:

• Density. This feature depends on chemical composition and ranges from 2200 to 6500 kg/m³. As the temperature rises, the density of the glass decreases and it becomes particularly brittle.
• Strength. Depending on the type of glass, its strength varies from 50 to 210 kgf/mm². A slight damage to the surface of the material reduces this figure by 3-4 times.
• fragility b. The fragility of glass and its inability to withstand impact limits its use in some areas of life. When certain chemical elements are added to the composition of the material, this characteristic increases.
• Heat resistance. Heat resistance - the ability of a material to withstand huge temperature changes. Ordinary window glass can withstand temperatures up to 90°C. In industry, these figures are increasing at times.

Types of glass.

Many products made of glass we see on the street and use in everyday life. These are glassware, light bulbs, glasses, windows. depending on the physical and chemical properties, glass is also used in the production of showcases, mirrors, lamps. What types of this homogeneous amorphous body exist and what is made of it?

• Crystal glass. Contains lead oxide. High transparency and gloss give this glass an attractive and aesthetic appearance. They are mainly used for the manufacture of dishes and souvenirs.
• quartz glass. The composition contains the purest quartz sand. Due to the fact that quartz glass products can withstand large temperature fluctuations, laboratory glassware, insulators, optical instruments, and windows are made from it.
• Foam glass. It is a glass mass, which has numerous voids in its composition. Excellent thermal and sound insulation properties have led to its widespread use in construction.
• glass wool. It has the appearance of thin glass threads with high tear resistance. Used in both construction and chemical industry. Glass wool is fire resistant. Therefore, it is used as part of the material for sewing clothes for welders and firefighters.

To this list, you can add glasses that have specific properties :

• Fire resistant. Resists open flame and withstands high temperatures.
• Heat resistant. Has a low coefficient of thermal expansion and withstands sudden temperature changes
• bulletproof. Impact-resistant glass that can withstand powerful impacts.

How is glass made?

Glass production includes the following steps in its process:

1. Preparation of the necessary materials. The prepared raw material needs special processing. Quartz sand is enriched, and iron impurities are removed from its composition. Limestone and dolomite are carefully crushed.
2. Mixing material in certain ratios. The amount of this or that material and its percentage in the prepared admixture depends on the required physical and chemical properties of the glass products.
3. Cooking in glass furnaces. The cooking step takes place at a high temperature, the range of which ranges from 800°C to 1400°C. There is an active process of melting quartz sand, and the glass becomes viscous and transparent.

After obtaining a homogeneous glass mixture, the future products are formed, the product is abruptly cooled, followed by thermal and physical processing.

Application in industry

The use of a transparent, wear-resistant and durable material with a smooth surface is amazing. Despite the fact that glass is a very fragile material, it is widely used in various fields of industry and everyday life.

• mechanical engineering- is part of the non-stick paints that are used to process vehicles.
• paper industry- impregnation of the finished paper pulp.
• Construction- added to acid-resistant materials and refractory concrete structures.
• Chemical industry- production of detergents.

This functional material can be bent, cut, melted and unique and beautiful products can be obtained from it. That is why colored glass is actively used for decorative work in the construction of public buildings and all kinds of souvenirs are made.

Glass categories

According to its purpose, glass is divided into the following categories:

• Household glass. This group consists of five sub-groups - kitchen utensils, household utensils, lamp products, art products and household utensils.
• building glass- sheet glass, shop windows, double-glazed windows, heat-insulating double-glazed windows, reinforced glass.
• Industrial glass- laboratory instruments, protective products for industry, glass wool, optics.

In addition to protecting our homes from wind, rain and cold, glass gives a person a vast area for creativity. The process of creating it is as beautiful and mysterious as the material itself. Transparent, hard, acid-resistant glass has become an indispensable material in architecture and everyday life.

In this article, we examined in detail what glass is made of. This material has taken a special, important place in a person's life; without it, many household items would have been much more difficult.

Video: the process of making a substance