Glass. Receiving and using. Melting point of glass

Being one of the most ancient materials, glassused by mankind for not one thousand years. The universality of this substance allowed him to find application in a wide variety of industries. On the physical and chemical properties of glass refers to inorganic compounds, it is solid, has an amorphous structure, isotropic.

For each type of glass is characteristic in the processthe transformation of the aggregate state from a liquid, extremely viscous to a glassy species. The technology of production provides for its cooling at a rate that does not allow the transition to the crystallization phase of the melt.

The melting point of glass depends on itsquality and expected characteristics. Typically, cooking occurs over a fairly wide temperature range from 300 to 2500 ° C. The properties of this substance depend on the components that make up the glass-forming melts. Their list is quite extensive and is represented by various oxides, phosphates, fluorides and other additives. At the same time, classical transparency is by no means the last characteristic for various types of glasses, occurring both in nature and synthesized during production.

With the most ancient glass crafts,dating back to the seven centuries BC, were met by archaeologists engaged in excavations in Egypt. These were beads and amulets. But several millennia passed before the first industrial enterprises appeared, glassworks of the eighteenth century. The peculiarity of glass production in batch was that the melting temperature of the glass was achieved using coal, and the boilers for cooking became closed.

Before that, fuel was used for fuel,glassworks were not in place for a long time, the furnaces were scattered, and the fuel in the district was quickly consumed. The boilers were open, firewood did not emit substances that affect the transparency and color of the product. The melting temperature of glass in this type of process reached 1450 ° C.

An important event was the invention in the early XXcentury method of production of sheet glass, named for its developer Emil Furko, who offered the machine method of drawing. Having existed until 1959, it was superseded by the Float method developed by Pilkington.

The main components of conventional glass isquartz sand in the proportion of 69-74%, soda (12-16%), dolomite and limestone (5-12%). But in the technological process of production it is important not only at what temperature the glass melts, but also what is the rate of cooling the melt. Theoretically, with rapid cooling, it is possible to obtain a vitreous body from a metal, the main thing is to cool the melt until a crystal lattice is formed.

With all the variety of attractive propertiesordinary glass in its time, there was an urgent need for a more durable and lightweight transparent material. First of all, it touched the industry specializing in aircraft construction. Plexiglas got its name only from external similarities with traditional glass.

Its impact resistance is five times higher, it is easier in2.5 times. By light transmission it reaches a level of 92%, has a high resistance to aging. Much easier and more accessible plexiglas in processing. The melting point of Plexiglas is in the range of 90-105 degrees, which allows it to be heat treated.

But both of these materials have occupied every niche in modern production. Traditional inorganic glass firmly holds its positions and is not going to hand them over to the newest organic polymers.

Using a wide range of different impurities and additives allows not only to obtain amazing optical characteristics of glass, but also to significantly improve its mechanical properties.

In addition to industrial use,note the role of art glass. Masters-glass blowers, continuing the traditions of ancient artists, have turned the creation of masterpieces from glass into true art. In the furnaces of their workshops, the melting point of the glass is reached, working almost manually, in their work they not only exhibit an uncommon fantasy, but also expend a lot of physical effort.