What is Glass, How is it Produced?

The history of glass goes back to ancient times. Although it is not known exactly when it was first produced, the oldest glassware available are Ancient Egyptian beads dating to approximately 2500 BC. Glass vessels with feather-like colored zigzag patterns are found in later Egyptian finds. Mosaics made of glass in the modern sense can be found in Alexandria in the Ptolemaic period and in Ancient Roman civilizations.

Phase

Glass pendant ornament. Glasswork is common on the Italian island of Murano. Glass rings and other jewelry are made here.

Glass is an amorphous solid. In this state, it resembles a liquid substance in behavior from place to place. Viscosity, which is one of the general properties of liquid substances, is also a quality found in glass. In other words, glass is a fluid substance, but its flow time is so long that a human cannot observe this flow, its life span is not enough. Therefore, we can characterize glass as a liquid substance. In addition, glasses can be characterized as a solid phase that does not have a definite melting point as solids and exhibits liquid behavior.

The hot glass work technique is also traditionally called flame art.

Materials

There are three groups of substances that enter the composition of ordinary glass. These are substances called glassy oxides, solvents and stabilizers. These substances that enter the composition of the glass can also be called sand-soda-lime. Apart from the substances included in the composition of ordinary glass, there are auxiliary components that give the glass important properties and provide some benefits in production.

These substances, which have the characteristic of glassy, ​​are generally some oxides that form a network. Quartz sand is one of them. The most important of the network forming oxides are SiO2, B2O3 and P2O5 (phosphorus).

Smelters

The substances that are added to the glass composition in order to facilitate the melting of the network forming and glassy oxides are called melters. These substances reduce the melting temperature of the glassifiers and facilitate their melting. In particular, the melting point of silicon at 1713 ˚C drops to 1550˚C. Since the melters enter the mesh and change it, the melters are also called modifiers. The most important melting agent used in glass production is sodium carbonate (Na2CO3) or soda as it is commonly used. Soda is one of the most expensive raw materials used in glass production in terms of unit price.

Stabilizers (Stabilizers)

Stabilizers affect the chemical resistance, refractive index and dielectric qualities of the glass. A glass without stabilizer added to its formula is not stable against water. These glasses are called water glasses. The main substances used as stabilizers are CaO, BaO, PbO, MgO and ZnO. It is provided by adding CaO limestone (CaCO3) and MgO to the glass formula of dolomite (MgCO3). With the heating of these two substances, the CO2 in their structure is removed and oxides remain. Like CaCO3 = CaO+ CO2.