Safety glass varieties
Safety glass refers to glass with high mechanical strength and strong impact resistance compared with ordinary glass. Its main varieties are tempered glass, wired glass, laminated glass and titanium glass. When the safety glass is broken, its fragments will not hurt people, and it has the functions of anti-theft and fire prevention. Depending on the original glass used in production, safety glass has a certain decorative effect.
(1) The principle of tempered glass tempering
Tempered glass is also called strengthened glass. It uses physical or chemical methods to form a compressive stress layer on the glass surface. The glass itself has high compressive strength and will not cause damage. When the glass is subjected to an external force, this pressure layer can offset part of the tensile stress and avoid glass fragmentation. Although the inside of the tempered glass is in a state of greater tensile stress, there are no defects inside the glass and no damage will be caused. To achieve the purpose of improving the strength of the glass. Tempered glass is a secondary processing product of flat glass. The processing of tempered glass can be divided into physical tempering method and tempered tempering method.Physically tempered glass is also called tempered tempered glass. When it heats ordinary flat glass in a heating furnace to close to the softening temperature of the glass (600°C), the internal stress is eliminated through its own deformation, and then the glass is removed from the heating furnace, and then a multi-head nozzle is used to blow high-pressure cold air to the glass. On both sides, make it cool to room temperature quickly and evenly, and then tempered glass can be obtained. This kind of glass is in a state of internal tension and external compression. Once locally damaged, stress will be released. The glass is broken into numerous small pieces. These small pieces have no sharp edges and corners and are not easy to hurt people. Chemically tempered glass is to improve the strength of the glass by changing the chemical composition of the surface of the glass. Generally, it is tempered by the ion exchange method. The method is to immerse the silicate glass containing alkali metal ions into the molten lithium (Li+) salt to exchange the Na+ or K+ ions on the surface of the glass with Li+ ions, forming a Li+ ion exchange layer on the surface. The expansion coefficient is smaller than Na+ and K+ ions, so that the outer layer shrinks less and the inner layer shrinks more during the cooling process. When cooled to room temperature, the glass will also be in a state of tension on the inner layer and pressure on the outer layer. Its effect Similar to physical tempered glass. Tempered glass has high strength, and its compressive strength can reach 125MPa or more, which is 4 to 5 times larger than ordinary glass. The impact strength is also very high. When measured by the steel ball method, the 0.8kg steel ball is from 1. The glass can be kept intact when dropped from a height of 2m. The elasticity of tempered glass is much greater than that of ordinary glass. A piece of tempered glass of 1200mm×350mm×6mm can have a bending deflection of up to 100mm after being stressed. When the external force is removed, it can still return to its original shape, while ordinary glass can only be bent and deformed. A few millimeters. It has good thermal stability, and it is not easy to burst when subjected to rapid cold and rapid heat, which is another characteristic of tempered glass. This is because the compressive stress of tempered glass can offset part of the tensile stress caused by rapid cooling and rapid heating. Tempered glass has a heat shock resistance, the maximum safe working temperature is 288℃, and it can withstand a temperature difference of 204℃. Because tempered glass has good mechanical properties and thermal stability, it is widely used in construction engineering, transportation and other fields. Flat tempered glass is often used as doors and windows, partition walls, curtain walls, showcases, furniture, etc., while curved glass is often used in automobiles, trains and airplanes. It should be noted that the tempered glass cannot be cut or ground, and the corners cannot be impacted and extruded. It is necessary to select according to the ready-made size specifications or submit specific design drawings for processing and customization. The glass used in the large-area glass curtain wall should be controlled in tempering. Choose semi-tempered glass, that is, its stress cannot be too large, so as to avoid vibration and self-explosion caused by wind load. Depending on the original glass used, it can be made into ordinary tempered glass, heat-absorbing tempered glass, Cairan tempered glass, tempered insulating glass, etc.
(2) Wire mesh anti-theft glass
Wired glass is also called shatterproof glass or steel wire glass. It is produced by the calendering method, that is, the pre-heated steel wire or steel wire mesh is pressed into the middle of the glass in the molten state of the glass, and then annealed and cut. The wire glass surface can be embossed or polished, and the color can be colorless, transparent or colored. Wired glass is characterized by good safety and fire resistance. Wired glass not only improves the strength of the glass due to the skeleton effect of the steel wire mesh, but also when it is damaged by an impact or a sudden temperature change, the fragments will not fly away, avoiding the fragments from hurting people. When a fire occurs, when the flame spreads, the wire-inserted glass is heated and bursts. Due to the effect of the metal wire mesh, the glass can still be fixed to isolate the flame, so it is also called fire-resistant glass. According to the national industry standard JC433-91, the thickness of the wire glass is divided into: 6, 7, 10mm, and the size is generally not less than 600mm×400mm and not more than 2000mm×1200mm. At present, the laminated glass produced in our country is divided into two types: laminated embossed glass and laminated polished glass. Wired glass can be used for anti-doors and windows, skylights, daylighting roofs, balconies and other parts of buildings.
(3) Laminated glass Laminated glass
Laminated glass is a flat or curved composite glass product formed by heating and pressure bonding between two or more original glass sheets with PVB (polyvinyl butyral) resin film. The original sheet used for laminated glass can be ordinary flat glass, float glass, tempered glass, colored glass, heat-absorbing glass or heat-reflecting glass, etc. There are 2, 3, 5, 7 layers of laminated glass, up to 9 layers. For two-layer laminated glass, the thickness of the original sheet is commonly used (mm): 2+3, 3+3, 3+5 Wait. Laminated glass has good transparency, and its impact resistance is several times higher than that of ordinary flat glass. It can be combined with multiple layers of ordinary glass or tempered glass to make bulletproof glass. Due to the adhesive effect of PVB film, even if the glass is broken, the shards will not fly out and hurt people. By using different original glass, laminated glass can also have durability, heat resistance, humidity resistance and other properties. Laminated glass has a high degree of safety and is generally used in buildings as doors and windows of high-rise buildings, skylights and shops, banks, jewelry windows, partitions, etc.
(4) Titanium glass
Titanium glass is also called never-broken iron armor foil film glass. It is a new type of glass in which the titanium foil film is closely attached to any kind of glass substrate to integrate it into a whole. Titanium glass has high shatter resistance, high heat resistance and UV protection. Different substrate glass and different titanium foil films can be combined into titanium glass with different colors, different properties, and different specifications. The common colors of titanium glass are: colorless and transparent, brown, brown reflective, copper reflective and so on.
CRYSTOEandNEOPARIES (CRYSTOEandNEOPARIES) is also called microcrystalline jade or ceramic glass. It is a comprehensive glass, a new type of building material that has just been developed in foreign countries, and its scientific name is called glass crystal. Glass-ceramics look very different from our common glass. It has the dual characteristics of glass and ceramics. The arrangement of atoms inside ordinary glass is irregular, which is one of the reasons why glass is fragile. And like ceramics, glass-ceramics are composed of crystals, that is to say, its atomic arrangement is regular. Therefore, glass-ceramics have higher brightness than ceramics and stronger toughness than glass.