How glass is made. How to make glass? Glass production technology

Glass is the most ancient object that has been found by man and is still used today. Found because a person did not invent it himself and made it for the first time. Most likely, the first glass appeared many thousands of years ago from volcanic lava. Nowadays this substance is commonly called obsidian. How is glass made? Let's go back to the times when he didn't exist yet. Gradually, people became aware of the surrounding nature and noticed that when natural soda was mixed with sand and then heated, a transparent substance appeared. This is how they became aware of this new type of material. This process was described by Pliny, the ancient Greek encyclopedist. It was from that moment that the history of the use of glass began, which has become absolutely indispensable in our lives today. After all, now it is used everywhere.

However, there is another theory regarding how glass is made, or more precisely, how it was made before. Some scientists decided that the glassy material was discovered as a by-product of copper smelting or roasting. In human life, this product played a truly outstanding role. It is difficult to overestimate its importance. The production of sheet glass is comparable to such discoveries as the making of fire and the invention of the wheel. During the times of Ancient Egypt, it was customary to make all kinds of jewelry from it. Later they learned to make containers for liquids from it. From the thirteenth century there was a sharp increase in the amount of glass produced. Venice became the center of its production. The masters became aware of the technology for creating oriental glass, after which they began to develop and improve it. The transparency of glass became possible thanks to the addition of various impurities to it. Masters began to make various dishes from it, which were very thin and elegant. In those days, glass products served more as luxury items and decorations.

If the question of how glass is made is still interesting to you, then you can talk about how it found more and more new areas of application. Its production technology has improved. A mirror was invented, this was done by applying amalgam to one side. Glass also began to be used in construction. It was usually used in the construction of palaces and temples. And after the craftsmen learned how to make it in color, they began to decorate windows with it, making beautiful stained glass windows. And now glass is widely used for fusing. And over time, glass began to be used in science. Thanks to the discovery of its ability to concentrate and scatter light, various lenses were created, telescopes and microscopes were made. These discoveries became a giant step in the development of the natural sciences - medicine, biology, astronomy, physics and others. No activity in any scientific field is possible without glass.

How is glass made? Like once before, made of sand. At its core, sand contains quartz, presented here in the form of crystals. When heated it melts. If you cool it quickly, the minerals will not have time to crystallize, becoming transparent. To give the product any color, oxides are added. different metals. To give the glass maximum transparency, the sand is cleaned so that it contains almost only quartz.

On this moment There are many ways to obtain a product with different properties: reinforced, hardened, mirrored, armored. The base is still simple sand, which is processed. It is important to say that there is still enough sand on the planet, so glass will not soon go out of our use.

Glass is a material that has no analogues in some properties. Until now, natural ingredients are used for its production; reprocessing of a damaged product can occur repeatedly without loss of quality and almost without waste.

Definition

Glass can be in several states of aggregation at different stages of production. And yet, what is glass and what is it made from?

According to the scientific definition, glass is any amorphous body obtained by melting, which, with increasing viscosity, acquires the properties of a solid. In this case, the process of transition from one state to another is reversible.

History of the material

IN Everyday life we use glass every day. What it is and what it is made of are questions rarely asked in modern times, the material is so familiar to us. Scientists believe that glass was first obtained by accident; it is impossible to trace the origin of the technology. The first products date back to approximately 2540 BC. The ancient recipe contained three components - soda, sand and alumina. Later we learned to improve the properties of the material by adding chalk, dolomite and other components to the main ingredients. The entire composition from which glass is made is called a charge.

Colored glass began to be produced using natural pigments - chromium oxide, nickel oxide, cobalt additives. The first molded product was produced in the 1st century AD by Roman craftsmen. They also invented sheet glass. The technology for producing glass in sheets consisted of blowing a huge, human-sized cylindrical bubble from a hot mass. While it was still hot, it was cut along the long side and laid out on trays for leveling. This technique was widespread until the beginning of the 20th century. In Russia, glass production was opened in the 17th century and was located in the village of Dukhanino; at that time, only foreigners were craftsmen.

Compound

Glass is used for many purposes. What is glass, we have understood, but what are its main ingredients? The composition of the starting ingredients has remained virtually unchanged over the entire period of practice in manufacturing the material. Three main components make up the base (charge) - silica or quartz sand, soda (sodium oxide) and calcium oxide, known as lime. The components are combined in certain proportions and melted in a furnace at temperatures from 300 to 2500 ° C. Depending on the desired properties, potash, boric anhydride, broken glass from previous brewings or recycled raw materials are added to the composition of the charge.

Technology

To enhance or weaken the properties of compounds, amplifiers, opacifiers, dyes, decolorizers, etc. are added to the melting process. After cooking, the mass is quickly cooled, which avoids the formation of crystals. Of all the components, the largest percentage in the recipe is sand - from 60 to 80%. The sand acts as a framework around which a glassy material is formed. Glass production technology has remained unchanged for centuries.

Lime is another component without which glass cannot be produced. What is calcium oxide in the ingredients? This component gives the material chemical resistance and enhances shine. Glass can be melted only from sand and soda, but without lime it will dissolve in water. The third player in the charge is metal oxide - sodium or potassium (up to 17%). It is added to the mixture in the form of soda ash or potash. These components reduce the melting point, allowing individual grains of sand to completely melt and combine into a monolith.

Kinds

Depending on the components used in the charge, glass types are divided:

Quartz. It is made from one component - silica. It has high qualities: resistant to high temperatures (up to 1000 °C) and thermal shock, transmits visible and ultraviolet radiation. Production is associated with high energy costs, since silica (silicate glass) is a refractory raw material and is difficult to mold. The main areas of application are chemical and laboratory glassware, parts of optical systems, mercury lamps etc.
Sodium silicate. It is made of two components, the glass composition is silicate sand and soda (1:3). Due to its properties, it is widely used in industry as a component of any process, but is not used in other areas, products are not made from it. The main disadvantage is that it dissolves in water.
Limestone. The most common type of material from which most products are made is sheet glass, glass containers, mirror cloth, dishes and much more.
Lead. Lead oxide is proportionally added to the classic glass composition (charge). Lead glass has increased dielectric properties, which allows it to be used as the best insulating composition in television tubes, oscilloscopes, capacitors, etc. The presence of lead in the glass mass gives the material additional shine and sparkle, which is often used in the manufacture of artistic products, dishes, etc. d. Crystal is a type of lead glass.
Borosilicate. The addition of boron oxide to the composition of the material increases its resistance to thermal shock up to 5 times, significantly improving Chemical properties. Borosilicate glass is used for the manufacture of pipes and laboratory chemical glassware, products for household needs. A large-scale example of use is a mirror created using borosilicate glass for the world's largest telescope.
Other types of glass - aluminosilicate, borate, colored, etc.

Types of window glass

Window glass is the most popular type of material. It allows sunlight to pass through, provides thermal insulation in winter and summer, prevents noise penetration, aesthetically decorates the window opening and performs many other functions. Today there is a wide selection of types of glass, each of which meets certain requirements:

Energy saving. A type of glass tinted in bulk or coated with a special film, which allows short-wave solar radiation to penetrate into the room, while long-wave radiation from heating devices is not allowed out of the room. The second name is selective glass. To date, several types of coatings have been developed. The most promising are K-glass (deposition of metal oxides onto the surface) and i-glass (vacuum multilayer deposition of silver - dielectric).
Sun protection. Reduces the transmission of sunlight into the room. They are divided into two types - reflective and absorbing. The effect is achieved either by tinting the glass in the mass during cooking, or by applying a special film to the surface.
Decorative. Window glass with additional aesthetic characteristics - patterned, colored, etc.

Safety glasses

One of the negative qualities of glass is its fragility; there are technologies for strengthening the material. The most common types:

Reinforced. Sheet glass, during molding of which a metal mesh is embedded into the mass. Scope of application - industrial premises, street lighting, lining of elevator shafts, etc.
Laminated or triplex. Two or more glasses are held together with a special film or liquid. This type of material significantly reduces the noise level in the premises. Also, when using additional color filters during lamination, it can perform sun protection functions. Triplex has increased mechanical stability; when the canvas breaks, the fragments remain attached to the film, which makes it as safe as possible for use in facade, balcony, window, and door glazing.
Fire resistant. Most often it is produced using lamination technology with special films, which at temperatures above 120 ° C change their physical properties and, expanding, become matte, giving rigidity to the glass.
Protective. It is a multilayer material consisting of several types of glass bonded with a polymer film. For example, silicate glass is bonded to polycarbonate and organic glass. This translucent block is resistant to mechanical, chemical, and impact damage. Security types of glass include bullet-resistant, shock-resistant, puncture-resistant and other types. Technical requirements The material and classification of protective glass are regulated by GOST R 51136.
Tempered. Has high strength characteristics. The effect is ensured by glass production technology - in a special tunnel furnace, sheets are briefly exposed to high temperatures and quickly cooled. When broken, tempered glass crumbles into small fragments that do not pose a threat to life and health. The disadvantage is the impossibility of mechanical processing of hardened fabric; at the slightest impact it is destroyed. Most tempered glass products are first shaped, cut or otherwise processed before being tempered.

Auto Glass

Glass for cars has increased strength characteristics that meet safety requirements. Today, two technologies are used in production - lamination (triplex) and hardening (stalinite):

Tempered glass is obtained by heat treatment of ordinary silicate glass, heating it in a furnace to a temperature of +600 °C, followed by rapid cooling. It acquires mechanical and thermal strength, but with strong impacts it collapses, breaking up into small safe fragments that do not have cutting or piercing edges. Russian marking is the letter “Z”, European marking is “T” or Tempered.
Laminated is two thin sheets of glass bonded with a polymer film under the influence of temperature and vacuum. The properties of glass are such that it remains intact under strong impacts and does not break into fragments if it bursts. The parts remain secured with film. Triplex has additional capabilities - tinting with color filters during the lamination process, additional sound insulation of the interior, low thermal conductivity, etc.

Modern developments

The twentieth century can be called a time of widespread use of glass. After the development of technology for mechanical methods of obtaining the material, it began to be used in a variety of fields - as the finest fiber in the field of telecommunications, and with no less success it is used in large multi-ton blocks in construction technologies.

The properties of glass are diverse; they continue to be studied in scientific institutes, and craftsmen find new uses and invent new types. In 1940, glassmakers introduced foam glass to the world. Its qualities are:

Lightweight - does not sink in water, has a cellular structure, the specific gravity is slightly higher than the weight of cork.
Moisture resistance, durability.
Environmental friendliness (in classic recipe coke was added to the charge).
Fireproof (does not burn) and suppresses fire.
The material can be sawn into pieces without compromising quality.

The scope of application is insulating materials for hazardous industries, refrigerators, etc.

For solar panels They use glass with a conductive coating of a thin layer of metal oxide. Coated panels operate at temperatures around 350 °C. In addition, such glass is installed in aircraft cabins to avoid ice and retain heat inside the cabin.

An important achievement of modern times has been the possibility of producing glass ceramics. The material is made using conventional glass technology, but at the last stage of cooling the process slows down and crystallization occurs in the mass of the material. Catalysts are special additives that do not affect the external state of the glass in any way, but form small crystals. The material can withstand high temperatures without deformation and is more resistant to all types of damage. Used in rocket science, home appliances, laboratories, engine parts and many other fields.

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 Ancient Rome do 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.

Such a thing as glass surrounds us everywhere: windows in a house or car, aquariums, dishes, decorative items, retorts and beakers in industry and medicine, even watches have it. Interesting Facts:

It takes a million years for glass to decompose.
When recycled, glass retains all its qualities.
The thickest sheet of glass is the screen of the aquariums in Sydney. Its thickness is 26 cm.

Modern production technologies make it possible to obtain glass with a wide variety of characteristics and qualities:

Household. It is used in everyday life: dishes, glasses, decorative items.
Technical. This is a very dense glass used in heavy industry.
Construction. Showcases, stained glass, and windows are made from it.
Bulletproof. Used to improve the safety of buildings, cars, etc.

Today, looking at a tiny watch dial, we can think: which glass is better: sapphire or mineral. We can choose material of various shades for finishing our windows: blue, red, green or no color at all. Buy a matte white simple vase or a multi-colored bright freeform product from professional glassblowers. It’s even strange for such popularity that very few people think about how glass is made? What is needed for this?

What is glass made from?

Not only the manufacturing process itself is curious, but also what glass is made from. The basis is usually only three ingredients, and each of them has its own role in the creation process:

Quartz sand is the base. Its melting point is 1700⁰С.
Soda. It helps to reduce the melting point of sand by half and significantly simplify the manufacturing process.
Lime. This component is necessary for waterproofing. If it were not there, then we would not be able to put flowers in a vase, we would not be able to drink tea from a glass, since water would simply dissolve such an alloy.

Making glass is a fairly hot, labor-intensive and dangerous process. First, all components are mixed and melted in a special furnace. After the grains of sand combine with each other, turning into a homogeneous mass, it is sent to a bath with molten tin (its temperature is above 1000⁰C). The glass mixture will float on the surface due to the difference in the density of the materials. The less mass there is in the tin container, the thinner the sample will be. After this, the workpieces are cooled on a special conveyor.

Curious history:

One of the oldest glass particles dates back to the 21st century. BC. Blue transparent wet glass was found in southern Mesopotamia. Glassmaking was also practiced in Syria, Egypt and Phenicia.
For many centuries, glass from Venice was considered the most expensive. The masters produced unusually thin and beautiful products: dishes, jewelry, mirrors, costing fabulous money. For a very long time, Venice was a glass monopolist, and the secrets of craftsmanship were jealously kept. In the 13th century, production was even moved to the island of Murano, and craftsmen were forbidden to leave it under pain of death. Despite this, glassmakers were a special, rich and privileged caste. An unheard of thing for that time: having married the daughter of such a master, the guy moved into his wife’s family!
One of the world leaders in production today is China; it controls a third of the world market. And in the period from the 14th to the 19th centuries, the country did not produce glass at all.

As long as glass has existed, there have been varieties of it, differing in color. What is blue, green or red glass made from? What allows you to change the shade of a material to create a beautiful stained glass window, vase or sculpture? It's all about adding various chemical compounds, most often oxides:

The red color comes from the addition of iron oxide.
Purple and brown shades (it all depends on the quantity) – nickel.
The bright yellow color is uranium.
Shades of green – chrome and copper.
Rich blue – cobalt.

By the way, another oxide - this time aluminum oxide is used to produce sapphire glass for watches. It is very hard, you can only leave a scratch on it with a diamond!

Glass is an interesting and surprising material that is needed in many aspects of life.

As usual, we invite you to watch a fascinating video about how glass is made

31.10.2017 19:01 2116

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

Have you guys ever wondered what glass is made of?

People learned 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. Thanks to the interaction with soda, the sand melts better. Lime serves to strengthen the resulting material, and it does not collapse when interacting with water. If lime had not been added, the glass could simply dissolve upon contact with water. When the temperature reaches 1700 degrees, all three materials mix and become one substance, which is dipped 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. There, the glass is cut into standard pieces and adjusted in thickness.

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

Various forms of glass are obtained by blowing a heated mass. There is such a profession - glass blower. This is a master who makes glass of different shapes. The glassblower uses a special long tube in his work.

He attaches molten glass to its tip and blows out the resulting bubble. In this case, the glass blower rotates the tube, and the bubble falls into a special wooden or metal mold. Sometimes masters make their masterpieces without forms. They process the bubble blown from the tube using tools (tweezers, scissors, smoothers, etc.), giving it various shapes.