Technology of glass production.

Glass has been known for several millennia. The first mention of glass associated with the findings found in ancient Egypt 7000 years BC, glass beads and amulets. And the first glass factories began to appear only in the eighteenth century.


Glass is a state located in the frozen liquid. This is - an amorphous substance, which does not possess in the solid state properties of crystalline substances. The main components that make up glass are silica sand (69-74%), ash (12-16%), limestone and dolomite (5-12%) and small percentages some other components. In addition to the basic raw materials can enter various additives, such as coloring the glass in the desired color or to change other properties of the glass.

Technology for producing sheet glass is mainly based on two methods: Fourcault and Float.

In 1902 Emil Fourcault developed a method for drawing windows machine. In this method the glass is pulled from the glass furnace as a continuous strip mill rolls over, goes into the mine cooling, which is cut into individual sheets. Today in Europe Fourcault method is not widely applied, it replaced a more perfect float method.

Float method was developed in 1959 by <Pilkington>. In this process, the glass comes from the furnace melting in a horizontal plane in the form of a flat strip through a bath of molten tin on further cooling and annealing. The advantages of this method in comparison with all previous is:

• a stable thickness of the glass
• quality of the glass surface, which does not require further polishing
• the absence of optical defects in glass
• performance

The largest the size of the glass, as a rule, is 5000-6000 mm x 3210 mm and the thickness of the sheet can be from 2 mm to 25 mm.

The mass of glass produced in recent years significantly increased the proportion of functional (with special properties), and decorative glass. This is due to the fact that ordinary glass, used in architecture, does not meet current demand. At present it to the strict specifications of teplosberezheniya, mechanical strength, the spectral range of the transmitted radiation, etc.

Float-glass method can give some necessary properties on the stage of its production. The range is currently produced by the glass is so broad that it can cause confusion for inexperienced users. Some types of glass produced under their own names. To navigate in this diversity and make the right choice should be clear under what conditions will be operated by one or another glass. For example, the use of tinted glass in the mass, with a transmittance of less than 50% as facing facade glazing is not recommended. As a hot sunny day the panel out of it can be heated to a temperature of 80-90 ° C and above, which creates a large thermal stresses that may lead to the destruction of the panel with all the ensuing consequences. In this case, the use of special hardened reinforced and laminated glass.

In Russia, there is widespread enthusiasm for tinted (having a different color glass) glazing. In this fashion from Europe declined. This is due to many reasons. One of them noted above, the second is that much different from the natural spectral composition of light in negative impacts on human well-being. With a large degree of glazing, the people inside the room, losing all sense of time, and they have worse eyesight.

So, the choice of glass should be determined not only by aesthetic considerations, but also the optical-power characteristics of glazing and its biological effects.

In order to successfully apply modern types of glass used in building, it is necessary to understand what the solar radiation.

Consider the basic components of solar radiation:

1. Ultraviolet rays (wavelength 280-380 nm);
2. Visible light (wavelength 380-780 nm);
3. Short wave (wavelength 780-2480 nm);
4. Long waves (wavelength of 2480 and more).

Light rays are partially reflected glass, partially absorbed and some of them falls into the room, which, actually, there is a glass (Fig. 1). Transmittance of glass from 88% (for the ordinary float glass) to 19% (special).

Direct solar energy (short wave) - is an invisible part of the spectrum, it is also partly reflected in the glass (especially dark-colored), and some of it goes into the room. Solar Factor (SF) consists of a straight-through energy I and the energy absorbed by the glass II, which it passes inside.

Indirect solar energy (long wave) is transmitted in three ways:

• thermal conductivity
• convection
• thermal radiation
• 2/3 of heat loss through the glass is due to thermal radiation and the third by conduction and convection.

 Attaching the glass certain properties (creating different types of glass) can influence the penetration of the premises of a particular type of light energy.