There are thousands of different compositions of glass: at least 100.000 qualities and varieties are calculated.
Here are the most important ones based on their use.
Hollow glass
Bottles, glasses, flacons and flasks occupy a significant portion of glass production.
Chemical inertia, mechanical resistance and optical properties are exploited in various ways for every need, and glass is particularly suitable for containing liquids of all kinds, including for food and medicine.
Flat glass
They are widely used in construction and are classified according to the thickness of the sheet (simple, semi-double, double, half-crystal, ultra-strong), which can vary from 1,6 mm to 10-14 or even 19 mm.
Quartz glass
It is a glass made of pure silica, has important chemical-physical characteristics, but a high melting temperature and high viscosity. Its processing is very expensive.
Artistic glass
The production of handcrafted artistic glass has a longer processing time. For this reason, a percentage of substances is added to the silica which facilitate processing, but make the glass more fragile.
Art glass must also be able to accommodate coloring elements and doses of lead, which increase its brightness and refraction.
Optical glass
It is the glass intended for the lenses of spectacles, microscopes and telescopes, for the objectives of cameras and video cameras: it must therefore be particularly refined.
A particular type of glass, called photochromic (or photochromic), absorbs light becoming darker, until the light radiation ceases.
Safety glass
The fragility of the glass and the formation of small and sharp splinters constitute a serious obstacle to the use of the sheets in building constructions, due to the resulting danger.
Therefore, tempered glass, with diversified cooling, much more resistant and which shatter into very small less sharp fragments were studied; or laminated glass, obtained by coupling two sheets with the interposition of a sheet of thermoplastic material, to which the fragments adhere in case of breakage (for example in the windshield of the car).
Glass for fibers
The glass fibers can have a diameter from 1 to 8 microns and a tensile strength from 8500 to 20000 kg / cm2; the elasticity is also remarkable. They are obtained by drawing the molten glass, through a platinum die with numerous holes.
Glass fibers (fiberglass, in English) are used, due to their lightness and strength, in cladding panels, car bodies, etc. By blowing with air and steam, short and discontinuous fibers are obtained, suitable for insulating panels.
Source: wikipedia, technology.annibalepinotti.it
