By shape
Tempered glass is classified into flat tempered glass and curved tempered glass according to its shape.
There are generally twelve thicknesses of flat tempered glass, such as 11, 12, 15, 19mm, etc. There are eight thicknesses of curved tempered glass, including 11, 15, 19mm, etc. The specific thickness after processing still depends on the equipment and technology of each manufacturer. However, curved (i.e., curved tempered) glass has a maximum curvature limit for each thickness. That is, what is commonly referred to as R, where R is the radius.
2. Tempered glass is classified into flat tempered and curved tempered according to its appearance.
3. Tempered glass is classified by its flatness into: superior grade and qualified grade. Superior tempered glass is used for automotive windshields. Qualified products are used for architectural decoration.
According to the process
Physical tempered glass is also known as quenched tempered glass. It is made by heating ordinary flat glass in a heating furnace to a temperature close to the softening point of the glass (600℃), eliminating internal stress through its own deformation, then removing the glass from the heating furnace, and using multi-head nozzles to blow high-pressure cold air onto both sides of the glass, allowing it to cool rapidly and evenly to room temperature, and thus tempered glass can be produced. This kind of glass is in a stress state of tension inside and compression outside. Once a local breakage occurs, the stress will be released and the glass will break into countless small pieces. These small fragments have no sharp edges or corners and are less likely to hurt people.
Chemical tempered glass enhances its strength by altering the chemical composition of its surface, and it is typically tempered through the ion exchange method. The method is to immerse silicate glass containing alkali metal ions into molten lithium (Li+) salt, so that Na+ or K+ ions on the surface layer of the glass exchange with Li+ ions, forming a Li+ ion exchange layer on the surface. Since the expansion coefficient of Li+ is smaller than that of Na+ and K+ ions, during the cooling process, the outer layer shrinks less while the inner layer shrinks more. When cooled to room temperature, the glass is also in a state where the inner layer is under tension and the outer layer is under pressure, and its effect is similar to that of physically tempered glass.
By tempering degree
1. Tempered glass: Tempering degree =2-4N/cm, surface stress α of tempered glass for glass curtain walls ≥95Mpa;
2. Semi-tempered glass: Tempering degree =2N/cm. The surface stress of semi-tempered glass for glass curtain walls is 24Mpa≤α≤69Mpa.
3. Super tempered glass: Tempering degree >4N/cm.
Flat tempered glass and curved tempered glass belong to safety glass. It is widely used in high-rise building doors and Windows, glass curtain walls, indoor partition glass, skylights, sightseeing elevator passages, furniture, glass guardrails, etc. Usually tempered glass can be used in the following industries:
1. Construction, building formwork, decoration industry (e.g. Doors and Windows, curtain walls, interior decoration, etc.)
2. Furniture manufacturing industry (glass coffee tables, furniture accessories, etc.)
3. Home appliance manufacturing industry (such as televisions, ovens, air conditioners, refrigerators and other products)
4. Electronics and instrumentation industry (various digital products such as mobile phones, MP3 players, MP4 players, and watches)
5. Automotive manufacturing industry (such as car window glass, etc.
5. Daily products industry (such as glass cutting boards, etc.)
Youdaoplaceholder0 Specialty industries (Glass for military use)
Because tempered glass breaks into uniform small particles and does not have the sharp corners of common glass knives, it is called safety glass and is widely used in automobiles, interior decoration, and Windows that open to the outside on high floors.
