Glass Technology

Glass Overview

Glass is a solid material is amorphous (non crystalline). Glass (glass) itself in the German language has a transparent meaning. Glasses are usually fragile, brittle, and often are optically transparent. Glass is generally used for windows, bottles, glasses and examples of materials including glass of soda lime glass.

Strictly speaking, glass is defined as an inorganic product of fusion that has cooled through the glass transition for the solid state without crystallization process. Many glasses contain silica as its main component and glass formers. The term "glass", is often extended to all amorphous solids (and melts that easily form amorphous solids), including plastics, resins, or other silica-free amorphous solids. Glass plays an important role in science and industry. Optical properties and physical properties of glass make it suitable for applications such as flat glass, glass containers, optical and optoelectronic materials, laboratory equipment, thermal insulator (glass wool), reinforcement fiber (glass reinforced plastic, glass fiber reinforced concrete), and art .

HISTORY OF GLASS

Glass obsidia originally derived from material that is formed from volcanic lava, and in fact has been known since the stone age. According to one reference, the first glass makers are a nation of Egypt around 2000 BC. At that time, the glass used as packaging pottery and a number of other objects. In the first century BC, developing and manufacturing techniques of glass became more widely used in everyday life.

At the time of the Roman Empire largely shaped glass products and glass bottles. Then in the 12th century stained glass was made by mixing the dye in the form of metal oxides. This type of glass is less developed because it is not used widely by the public. In the 14th century glass-making center is the city of Venice in Italy. This city gave birth to many new techniques, and glass products eventually become important commodities, such as plates, cups, bowls, mirrors, and other luxury goods.

Then around the year 1688, the glass manufacturing process uses a number of ways that have been developed, so that the glass products are more easily made. With the birth of glass products processing machinery in 1827, the glass-based products can be made in bulk, the price is cheaper. In the mid-1800s introduced the process of making glass crown (crown glass process).

Glass Production

* Composition of Making Glass

Quartz sand (silica) as main raw material for commercial glass production. Pure silica (SiO2) has a melting point (in the viscosity of 10 Pa / s) more than 2,300 ° C (4,200 ° F). Pure silica can be made into glass for special applications, but there are other substances are added to the glass to simplify the process in general. One is sodium carbonate (Na2CO3), which can lower the melting point of about 1,500 ° C (2,700 ° F). However, the soda makes soluble sodium silicate, which is usually not desirable. So, grilled lime (calcium oxide (CaO), which is generally derived from burnt limestone (CaCO3)), some magnesium oxide (MgO) and aluminum oxide (Al2O3) was added to provide better chemical resistance. The resulting glass contains about 70-74% by weight of silica glass itself.

In addition to soda and lime, other additional material on the most common glass to change its properties. Crystals (Crystal) more brilliant because of the increased refractive index causes look more "sparkling", while boron may be added to change the thermal and electrical properties, such as Pyrex. Adding barium also increases the refractive index. Thorium oxide makes glass has a high refractive index and low dispersion, and never used in producing high-quality lenses, but given the radioactivity has been replaced by lanthanum oxide then this world are rarely used in modern glasses.

In large quantities, iron is used for glass that absorbs infrared energy, such as filters to absorb heat in film projectors, while cerium (IV) oxide can be used for glass that absorbs the UV wave (biologically damaging ionizing radiation). Two other common glass material is calumite (a byproduct of steel industry) and "cullet" (glass recycling). Recycled glass saves raw materials and energy. However, impurities in the cullet may lead to failure of products and equipment. Finally, glass complement agents such as sodium sulfate, sodium chloride, or antimony oxide is added to reduce the bubble content in the glass.

* Glass Making in Several Age

How to blow down the first is the traditional way is to form the glass. But the growing period so that this technique is getting a little abandoned. Common method now is to make a mixture of glass is SiO2 (quartz sand), NaCO3 (sodium carbonate), CaO (calcium oxide), and other additions in melting in the furnace and then printed. Things like this will be faster and more uniform results.

To strengthen the crystal structure of glass commonly used technique of glass coated with certain polymers. This technique is commonly known lamination techniques. This technique is to make bulletproof glass.

* Addition of Color Compound

Colored glass produced by mixing with a bit of transition metal oxides. For example, manganese oxide will result in the color purple, cupric oxide and chromium provide the green color, and oxides cobalt give blue.

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