Glass - what is it and how is it produced? Properties of glass

Each of us has met glass many times. What is this fragile and transparent material, any schoolboy knows. We see it every day in mirrors, windows, in dishes and furniture, but are we well acquainted with it? How is it produced, what is it and what are the properties of the glass?

What does this word mean

There are many reference materials that can help in this matter. What is the meaning of the word "glass" according to one of the most popular sources? Ozhegov's dictionary describes this substance as a solid material, obtained from quartz sand mixed with the oxides of certain metals. Even the definition gives some idea of the way the material is produced. But we will move on to this topic later.

Surely everyone is used to the fact that glass is a transparent material. But pay attention - Ozhegov's dictionary does not give such specification. Glass can be not only transparent, but also colored or matte. But the composition of the material differs insignificantly.

What do glass do?

The standard composition of glass is a mixture of pure quartz sand, lime and soda. Various additives can be used to change the properties of the material. But still the main component is pure river sand. Its amount is approximately 75% of the total mixture. Soda can reduce the melting point of sand by almost 2 times. Lime protects the glass from the effects of most chemicals, and also adds strength and shine.

Additional impurities:

• Manganese. It is added to the glass to obtain a specific green hue. For other colors, nickel or chromium can be used.
• Lead gives the glass extra shine and characteristic ringing. The material is more cold to the touch. Glass with an admixture of lead is called crystal.
• Boric acid also imparts additional gloss and transparency to the material, while lowering the coefficient of thermal expansion of the products.

History of glass production

Even 6000 years ago, people were able to create this beautiful and fragile material. Of course, its appearance was somewhat different from modern glass, because in Ancient Egypt and Mesopotamia there was no equipment for high-quality cleaning of sand and other tools. Nevertheless, the production of glass began there. Due to its resistance to environmental influences, this material gave historians an idea of the culture and technical capabilities of the most ancient peoples.

In Russia, the first glass manufacturing plant appeared in 1636. It was located near Moscow. There they created dishes and window panes. This branch of industry developed under Peter I.

Only in 1859 the invention of a high-pressure pump allowed the creation of glass without the participation of glass blowers. This greatly simplified production. And in the beginning of the 19th century an interesting property of the material was discovered - if the finished product was heated to a certain temperature, the mechanical properties of the glass would increase by 400%.

Modern production

Technologies have stepped far ahead, which allowed the creation of any materials in huge quantities and with the least human effort. At present, there are many factories where glass is created according to standard established technology. What is modern material, obtained from molten quartz sand, we learn by getting acquainted with the technology. As an example, take the sheet material.

Glass production by stages:

1. All the necessary ingredients are loaded into the oven and heated until a liquid homogeneous mass is formed.
2. In a special homogenizer, this alloy is mixed until uniform.
3. The resulting mass is poured into a flat container at the bottom of which there is molten tin. There the glass is distributed, forming a uniform thin layer.
4. Cooled and hardened material is sent to the conveyor. There the control of thickness of glass and cutting is carried out. Material that has not been tested, as well as defective parts, are sent for remelting.
5. The last quality control is carried out, after which the glass enters the finished goods warehouse.

Types of glass

Currently, this material is one of the most common. Not surprisingly, there are different types of glass, differing in appearance and physical properties. Here are some of them:

1. Crystal glass. It is a material containing lead. We spoke about him above.
2. Quartz glass. Contains in the composition of the purest sand, due to which it is distinguished by its high strength. It is able to withstand temperature fluctuations, therefore it is used to create optical instruments, laboratory glassware and windows.
3. Foamglass. Lightweight building material that can be used both for finishing, and for laying walls and floors. Contains a large number of voids, due to which it has high heat and sound insulation properties.
4. Glass wool. A volumetric air material consisting of thin and very strong threads. Fire-resistant, therefore, it is used not only in construction, but also in tailoring clothes for firemen and welders.

Application of glass

Depending on the properties and appearance of this material, almost any application can be found. The main consumer of glass produced in our time is the construction industry. It uses more than half of the material produced. Its purpose can be very diverse - facing the walls, glazing windows, erecting walls from hollow bricks, heat insulation, etc. To the construction area can be attributed and stained glass. What is a Gothic window, know for sure everything. Typically, it is lined with a large number of colored glass. Nowadays, the stained-glass windows have not lost their relevance and are used both in construction and in furniture production.

On the second place on popularity there are glass vessels of various purpose. A little less produced dishes. It is worth noting that in the chemical industry, glass is an indispensable material, since it is resistant to most reagents.

Physical properties

Like any other material, glass has a number of qualities that you need to know before using it in one area or another.

1. Density. It can vary depending on the composition of the mixture and the method of manufacture. The density of glass can range from 220 to 650 kg / m ³ .
2. Friability. This characteristic is a distinctive feature of glass and limits its use in the construction area. At present, scientists create more complex alloys, maximizing the strength of the material.
3. Heat resistance. Normal glass can withstand temperatures of up to 90 ° C. After processing, the thermal properties of the material are significantly increased. For example, industrial glass can withstand temperatures of more than 200 ^o C.

Interesting Facts

We learned a lot about glass - what is, how it is made and what properties it has. It's time to digress a little and get acquainted with the most interesting facts about this very common material. Few people know that:

• The speed of movement of the crack along the broken glass is 4828 km / h.
• The decomposition time of this material is about one million years.
• Glass can be repeatedly melted almost without loss of quality. In this respect, he has almost no analogues.
• Being an amorphous material, the molten glass will not solidify with rapid cooling. This requires special conditions.

Glass is not in vain so actively used in construction and other areas of human life. For sure it will remain for a long time one of the most popular materials. In favor of this statement speak strength, durability and the relative simplicity of glass manufacturing, due to the fact that the components for its creation are present on the Earth in large quantities.