Chemical composition
Production process method | SiO2 | Al2O3 | Fe2O3 | CaO | MgO | Na2O | K2O | SO3 |
Vertical lead up method | 72.0~73.0 | 0.5~2.3 | < ;0.1 | 6.5~8.0 | 3.0~4.2 | 14.5~15.5 | <0.3 | |
Flat drawing method | 72.0 | 0.6 | <0.1 | 8.0~10 p> | 4.2 | 13.0 | <0.3 | |
calendering method | 70.8~72.5 | 0.94~1.1 | <0.1 | 8.0~10.5 | 3.34~4.2 | 13.6 | 0.6 | <0.3 |
Float | 72.0~72.2 | 1.3~1.5 | <0.1 | 8.2~8.9 | 2.9~4.0 | 13.4~14.6 | <0.3 |
Classification
According to the thickness, it can be divided into thin glass, thick glass, and extra-thick glass; according to the surface condition, it can be divided into ordinary flat glass, patterned glass, ground glass, floating glass. French glass and so on. Flat glass can also be made into products with different colors and various special properties through coloring, surface treatment, compounding and other processes, such as heat-absorbing glass, heat-reflective glass, selective absorption glass, insulating glass, tempered glass, laminated glass, and wire Mesh glass, colored glass, etc. (see new architectural glass, safety glass). Ordinary flat glass: window glass, generally refers to flat glass produced by the processes of vertical lead-up with grooves, flat-drawn, vertical lead-up without grooves, and the Asahi method. According to the national standard <> (GB11614-2009), the net sheet glass can be divided into 2, 3, 5, 6, 8, 10, 12, 15, 19, 22, 25 mm according to its nominal thickness. Two specifications. It is used in general buildings, factories, warehouses, etc., and can also be processed into frosted glass, colored glazed glass, etc., and the thickness of more than 5 mm can be used as the blank for the production of polished glass. Common ground plates include polished glass and float glass, which are made of ordinary flat glass that is polished and polished on both sides, or produced by the float process. It is generally used for doors, windows, showcases and mirrors of civil buildings, shops, restaurants, office buildings, airports, stations and other buildings. It can also be used to process and manufacture toughened, laminated and other safety glass.
Characteristics
The flat glass has good see-through and good light transmission performance (3mm and 5mm thick colorless transparent flat glass has a visible light transmittance of 88% and 86% respectively), The transmittance of near-red heat rays in the sun is relatively high, but the far-infrared long-wave heat rays reflected by the indoor wall, furniture, and fabrics on the visible light are effectively blocked, so it can produce an obvious "warm room effect". Colorless and transparent flat glass has a low transmittance to ultraviolet rays in sunlight. Flat glass has sound insulation and certain thermal insulation properties, and its tensile strength is much lower than its compressive strength, which is a typical brittle material. Flat glass has high chemical stability. Under normal circumstances, it has strong resistance to acids, alkalis, salts, chemical reagents and gases, but long-term exposure to corrosive media can also cause qualitative change and damage, such as weathering of glass. Both mold and mildew will cause the appearance of the damage and the reduction of light transmission ability. Flat glass has poor thermal stability, and is prone to bursting due to rapid cold and rapid heat.
Grade
According to the national standard GB11614-2009, flat glass is divided into three grades: excellent, first-class and qualified according to its appearance quality.
Features
Because the thickness of the flat glass produced is about 5mm, it is a relatively thin glass, and its flatness and thickness are quite different. This flat glass is mainly The use of glass doors and windows in ordinary residential houses is a kind of architectural glass for residential use. After a certain amount of sandblasting, carving and grinding, and a certain corrosion treatment, this kind of glass can be made into screens, blackboards, and partitions. It can also be used as a kind of deep-processed product for better quality glass, such as original glass.
Traditional production
Traditional molding methods: The main molding methods of flat glass are manual molding and mechanical molding.
Manual molding
There are mainly bubble-blowing method, crown method, and tube-blowing method. These methods have been gradually eliminated due to low production efficiency and poor glass surface quality, and they are only used in the production of artistic glass.
Mechanical forming
Flat glass (13 sheets)
Mainly include calendering, grooved vertical lead up, counter roll (also known as Asahi method) ), vertical lead-up without groove, flat-draw and float, etc. The calendering method is made by rolling the molten glass in the melting furnace through calendering rollers, forming and annealing, and is mainly used to make wire (mesh) glass and patterned glass. The process of vertical lead-up method with grooves, counter-roll method, and vertical lead-up method without grooves are basically similar. The glass liquid is passed through trough bricks or rollers, or bricks are used to fix the roots, and the glass is lifted by the asbestos rollers of the guide The belt is pulled upwards, annealed, cooled, and continuously produced flat glass. The flat drawing method is to draw the glass vertically, and turn the glass ribbon into a horizontal direction with the help of a turning roller. These methods were common flat glass production processes before the 1970s.New production
The float process is a new method of making flat glass by floating glass liquid on the surface of the molten metal. It is a new process successfully researched by Pilkington Company in 1959. It is to continuously flow glass liquid from the kiln and float on the metal tin liquid surface protected by reducing gas. Relying on the combined effect of the surface tension of the glass, gravity and mechanical pulling force, it is drawn into glass ribbons of different thicknesses. After annealing and cooling, it is made into flat glass (also called float glass). When this kind of glass is formed, the upper surface forms a fire-polished surface in the free space, and the lower surface is in contact with the molten tin, so the surface is smooth, the thickness is uniform, no light distortion occurs, and its quality is no less than polished glass. This production method has the advantages of simple molding operation, excellent quality, high output, and easy automation. It has been widely used in the 1980s. If an alloy such as copper and lead is used as the anode on the surface of the high-temperature glass ribbon in the tin bath, and the tin liquid is used as the cathode, after direct current is applied, metal ions such as copper can be transferred to the upper surface of the glass to be colored, which is called "electric float method". ". It is also possible to set up a thermal spraying device between the exit of the tin bath and the annealing furnace to directly produce colored glass and heat reflective glass on the surface.
Use
The use of flat glass with different thicknesses is also different: (1) 3-4mm glass. When referring to the thickness of glass, millimeters (mm) are commonly referred to as "centimeters". When we flat
the 3 cm glass refers to the glass with a thickness of 3mm. The glass of this specification is mainly used for the surface of the picture frame. (2) 5-6mm glass. Mainly used in small-area light-transmitting shapes such as exterior wall windows and door leaves. (3) 7-9mm glass. It is mainly used in large-area but frame-protected shapes such as indoor screens. (4) 9-10mm glass. It can be used for indoor large-area partitions, railings and other decoration projects. (5) 11-12mm glass. It can be used for floor spring glass doors and partitions where some activities and people flow are larger. (6) Above 15mm. Generally, there are less sales on the market, and orders are often required. It is mainly used for the entire glass wall of the outer wall of the large-area floor spring glass door.
