How is the glass tempered, and how is the tempered glass made

Glass tempering: 1. Physical tempering method.

The principle of the physical tempering method is to heat the glass to a suitable temperature and then cool it quickly, so that the glass surface shrinks sharply and produces compressive stress, while the middle layer of the glass cools slowly and has no time to shrink, so the tensile stress is formed, so that the glass obtains higher strength. Generally speaking, the higher the cooling intensity, the stronger the glass. There are many physical tempering methods, which can be divided into the following according to the cooling medium:

2. Chemical tempering method.

Chemical toughening method refers to the tempering method that changes the surface composition of glass by chemical methods and increases the surface lamination stress to increase the mechanical strength and thermal stability of glass. Since it strengthens the glass through ion exchange, it is also called ion exchange enhancement method. According to the type of exchange ion and the temperature of ion exchange, it can be divided into ion exchange method below the transition point degree and ion exchange method above the transition point temperature.

The principle of chemical enhancement method is to change the surface composition of the glass according to the mechanism of ion diffusion, and immerse the glass in the alkali metal in the glass at a certain temperature in the high-temperature molten salt.

Ions and alkali metal ions in molten salt are exchanged with each other due to diffusion, resulting in the phenomenon of "squeezing", which causes compressive stress on the surface of the glass, thereby improving the strength of the glass.

The ordinary annealed glass is first cut to the required size, then heated to about 700 degrees close to the softening point, and then cooled quickly and evenly (usually 5-6mm glass is heated at a high temperature of 700 degrees for about 240 seconds and cooled down for about 150 seconds. 8-10mm glass is heated at a high temperature of 700 degrees for about 500 seconds and cooled down for about 300 seconds. In short, depending on the thickness of the glass, the time to choose heating and cooling is also different).

Glass strengthening is also commonly known as glass tempering. It is a physical or chemical method to form a compressive stress layer on the surface of the glass, and the glass itself has a high compressive strength. No damage.

When the glass is subjected to an external force. This pressure layer can offset part of the tensile stress to avoid the fragmentation of the glass, although the tempered glass is in a state of greater tensile stress, but the glass has no internal defects, will not be damaged, so as to achieve the purpose of improving the strength of the glass. Glass strengthening can be divided into physical strengthening and chemical strengthening.

Physical strengthening is to heat the ordinary flat glass in the heating furnace to a softening temperature close to the glass (600), through its own deformation to eliminate the internal stress, and then move the glass out of the heating furnace, and then use a multi-head nozzle to blow high-pressure cold air to both sides of the glass, so that it can be quickly and evenly cooled to room temperature. Tempered glass can be made.

This glass is in a state of stress in which the inside is tensioned and the outside is compressed. Once the local breakage occurs. The stress is released and the glass is shattered into countless small pieces, which have no sharp edges and are not easy to hurt.

Chemical strengthening is to improve the strength of glass by changing the chemical composition of the surface of the glass, generally by applying ion exchange method for toughening. This is done by immersing silicate glass containing alkali metal ions in a molten state of lithium salt. The sodium ion or potassium ion of the glass surface layer is exchanged with lithium ions, and the lithium ion exchange layer is formed on the surface, because the expansion coefficient of lithium ions is less than that of potassium and sodium 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 is also in a state of tension on the inner layer and compression on the outside, and its effect is similar to that of physically tempered glass.

into the characteristic furnace, changing the internal molecular structure.

Method 1: Physical tempering method, the glass is heated to a suitable temperature and then cooled rapidly, so that the glass surface shrinks sharply, resulting in compressive stress, and the middle layer of the glass cools slowly, and it is too late to shrink, so the tensile stress is formed, so that the glass obtains higher strength.

Method 2: Chemical tempering method, a tempering method that changes the surface composition of glass and increases the surface lamination stress by chemical methods to increase the mechanical strength and thermal stability of glass.

Heating ordinary glass to about 700 degrees and then cooling it quickly is a brief process of tempered glass. There is also a kind of laminated glass on the market, which is to tightly stick two pieces of glass together with transparent glue, which can also play the effect that the glass is not easy to brittle.

It is obtained by heating ordinary glass until the glass is softened, and then the slag grill is cooled quickly and evenly.

Tempered glass belongs to safety glass. Tempered glass is a kind of glass that usually uses chemical or physical methods to improve the strength of glass, forming compressive stress on the surface of glass such as Mengchang, and first counteracting the surface stress when the glass bears external force, thereby improving the bearing capacity and enhancing the glass itself Wind pressure resistance, cold and heat, impact and other characteristics of the glass.

The disadvantages of tempered glass are as follows:

The obvious disadvantage of this kind of glass is that it cannot be cut and processed casually after molding, and if you want to change the shape, you should operate before processing, and then it can be tempered.

Although tempered glass is stronger than ordinary glass, if the temperature difference changes very largely, it may also break, but ordinary glass will not be self-exposed.

The surface of the tempered glass will have uneven wind spots, and there will be slight thickness thinning. The reason for the thinning is that after the glass is softened by hot melting, it is quickly cooled by strong wind, so that the crystal gap inside the glass becomes smaller, the pressure increases, and the tremor is so that the glass is thinner after tempering than before tempering. <>

Hello, tempered glass can not remove tempering because 1, tempered glass is made of ordinary glass through a certain processing technology 2, put the glass into the tempering furnace heating, the temperature reaches the glass softness and then under a certain wind pressure rapid cooling, the high temperature glass in the action of strong wind rapid cooling, the surface temperature decreases quickly, the bridge burns the inside of the temperature to reduce slowly, so that the formation of the surface layer to the inside of the pressure and the inner layer of the inward tension, thereby improving the strength of the glass, the segment to achieve the tempered eye sensitivity. 3. The processing technology of tempered glass is irreversible, because the internal lattice structure of the glass has changed during the tempering process, and the structural bonds between the atoms have changed, and there is no way to reverse it back. Hope it helps.