Стекло – один из самых древних и универсальных materials. Glassware surrounds us everywhere, but usually we don’t think too much about its characteristics. They can vary greatly depending on the purpose of using the future product. One of the most common types is heat resistant glass. Let's find out how it differs from the usual and where it applies.
Glass is an inorganic substance.It is characterized by the properties of a solid, in a molten state, it is a highly viscous liquid. Its brittleness, strength, density and heat capacity vary greatly and depend on impurities.
Recently, materials have been developedwhich have atypical properties for glass, for example, fire resistance. The main parameter that distinguishes heat-resistant glass from other glasses is the temperature at which it retains its properties. It can withstand heating even at 1000 degrees Celsius, while its “colleagues” already crack at 80 degrees.
The refractoriness is affected by the composition and thicknessmaterial. If the glass is thick and contains a large proportion of alkali oxides, then it will be strong. The most resistant heat resistant glass - quartz. It withstands large temperature differences and has a high boiling point (2230 degrees).
Glass is usually a mixture of severalcomponents. For standard material take quartz sand, lime and soda. They are heated to very high temperatures (from 1700 degrees), which is why they melt and mix with each other. After that, the mixture is poured into molten tin (they do not mix due to the difference in density), and then gradually cooled.
To give the necessary properties to thesecomponents add other substances. To make heat-resistant glass, use a variety of oxides. So, in borosilicate material contains boron oxide, in quartz - silica.
Additional strength it will haveif you use multiple layers. To do this, it is allowed to cool completely. Finished sheets are sanded, cleaned and cut to size. Then several sheets of glass are glued to each other using a special polymer. The final touch is the burning of the glass "sandwich" at 660-680 degrees.
Heat resistant glass is popular onthe kitchen. Ovens and cookware are made from it. A common product of this material is also a fireplace. Quartz glass is used in the manufacture of optical fibers, Fresnel lenses, crucibles, insulators, etc. Borosilicate is used for optical glasses, dishes, reflector telescopes.
Refractory glassware has many advantages.It even withstands open fire, is durable. The material is rather inert and does not oxidize when heated, therefore it does not change the taste of the dish. It is not subject to corrosion and scaling.
Of course, even heat resistant glass hasdisadvantages. It reacts poorly to a sharp increase or decrease in temperature. Dishes from this material should not be put on a large fire immediately after the freezer. In addition, refractory glass is not shockproof, and you should not drop it.
