Glass Inspection|| How is glass classified? What are the characteristics of glass and a summary of related test items

Its main components are silica and other oxides. The chemical composition of ordinary glass is Na2SiO3, CaSiO3, SiO2 or Na2O· CaO·6SiO2, etc., the main component is silicate double salt, which is an amorphous solid with irregular structure.

The main variety of architectural glass is flat glass, which has the advantages of crystal clear surface, light transmission, sound insulation, heat preservation, wear resistance, climate change resistance, and stable material. It is made of quartz sand, sandstone or quartzite, limestone, feldspar, dolomite and soda ash as the main raw materials, through crushing, screening, batching, high-temperature melting, molding, annealing, cooling, processing and other processes.

With the development of modern science and technology and glass technology and the improvement of people's living standards, the function of architectural glass is no longer only to meet the requirements of lighting, but to have the characteristics of adjusting light, thermal insulation, safety (bulletproof, anti-theft, fireproof, anti-radiation, anti-electromagnetic interference), art decoration and so on. With the continuous development of demand, there are also new developments in the forming and processing methods of glass. New technologies such as lamination, tempering, ion exchange, glaze decoration, chemical thermal decomposition and cathodic sputtering have been developed, which have rapidly increased the amount of glass in construction and become the third largest building material after cement and steel.

Classification of glass

According to the thickness, it can be divided into thin glass, thick glass, and extra-thick glass; According to the surface state, it can be divided into ordinary flat glass, patterned glass, polished glass, float glass, etc. Flat glass can also be made into products with different colors and various special properties through coloring, surface treatment, composite and other processes, such as heat-absorbing glass, heat-reflecting glass, selective absorbing glass, insulating glass, tempered glass, laminated glass, wire mesh glass, color glass, etc. (see new architectural glass, safety glass).

Ordinary flat glass: that is, window glass, generally refers to the flat glass produced by slotted vertical lead, flat drawing, slotless vertical lead and Asahi method. According to the provisions of the national standard << Flat Glass >> (GB11614-2009), the net sheet glass can be divided into 12 specifications according to its nominal thickness, including 2, 3, 5, 6, 8, 10, 12, 15, 19, 22 and 25 mm.

Specialty glass production and characterization

Heat-reflective glass is a coated glass made by spraying gold, silver, aluminum, copper, nickel, ferrochrome and other metals and metal oxides or pasting organic films on the surface by heat, evaporation, chemical and other methods. Heat reflective glass has a high thermal reflection ability to sunlight, low thermal transmittance, generally thermal reflectivity is more than 30%, up to about 60%, and maintains good light transmittance, is the most effective modern anti-solar glass. Heat-reflective glass has unidirectional perspective, and its light-facing side has specular reflection properties, which not only has beautiful colors, but also maps the surrounding scenery, so that the building and the surrounding landscape are harmonized. The backlit surface of the glass is the same as the clear glass, so you can clearly see the outdoor scene. Heat-reflective glass is suitable for doors and windows, glass curtain walls, foyers of public buildings and various decorative parts of modern high-end buildings, and is used to make double-layer insulating glass and glass curtain walls with air layers, which can achieve excellent thermal insulation and energy-saving effects.

Glass testing items

Ultraviolet transmittance, chemical composition, ultraviolet reflectance, visible light transmittance, visible light reflectance, direct sunlight transmittance, sunlight direct reflectance, sunlight absorption, solar total transmittance, shading coefficient, solar infrared heat energy total transmittance, photothermal ratio, emissivity, wind pressure resistance, water tightness, air tightness, heat transfer coefficient, dew point, heat transfer coefficient, insulating glass sealing performance, impact resistance, thermal shock resistance, fragment state, shotgun bag impact performance, falling ball impact peeling performance, heat resistance, shotgun bag impact performance, etc.

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