What is tempered glass or toughened glass?

Tempered glass, also known as reinforced glass or toughened glass, is one kind of safety glass. Tempered glass is actually one kind of pre-stressed glass. In order to improve the strength of glass, chemical or physical methods are usually used to form compressive stress on the surface of the glass. When the glass is subjected to external force, it first offsets the surface stress, which thereby improves the bearing capacity of the glass, enhances the wind pressure resistance, cold and heat resistance of the glass.

 

Characteristics of tempered glass:

Advantages of tempered glass

1. The tempered glass is safe to people:

When the tempered glass is damaged by an external force, the fragments will form obtuse-angled small particles similar to honeycombs, which are not easy to cause serious harm to the human body.

2. The tempered glass has higher strength compared with ordinary glass.

With the same thickness, the impact strength of the tempered glass is 3 to 5 times that of the ordinary glass, and the bending strength is 3 to 5 times that of the ordinary glass.

3. The tempered glass has good thermal stability.

The tempered glass has good thermal stability, and can withstand a temperature difference 3 times that of ordinary glass, and can a temperature change of 300℃. tempered glass is widely used for high rise buildings.

 

 

Disadvantages of tempered glass:

1. the tempered glass can no longer be cut and processed. The glass can only be processed to the required shape before being tempered and after finishing cutting, then go to be tempered.

2. Although tempered glass is stronger than ordinary glass, tempered glass has the possibility of self-explosion(self-rupture), while ordinary glass does not have the possibility of self explosion.

3. The surface of tempered glass may have unevenness(wind spots) and the thickness of the glass become slightly thinner. The reason for the thinning is that after the glass is melted and softened, it is rapidly cooled by strong wind, so that the crystal gap inside the glass becomes smaller and the pressure increases, so the glass is thinner after being tempered than that before be tempered. Generally, 4-6mm glass will become thinner by 0.2-0.8mm after being tempered, and 8-20mm glass will become thinner by 0.9-1.8mm after being tempered. The specific thinning degree depends on the tempering equipment, which is also the reason why the tempered glass can not be used as a mirror.

4. The flat glass used for buildings will generally be deformed after passing through the tempering furnace(also called toughening furnace), and the degree of deformation is determined by he equipment and the technical personnel. Which to a certain extent affects the decorative effect( except for special needs).

 

How tempered glass is fabricated?

The tempered glass is obtained by cutting ordinary annealed glass into the required size first, then heating it to about 700℃ closing to the softening point, and then cooling it quickly and uniformly(usually 5-6MM glass is heated at 700℃ for about 240 seconds, cooling down for about 150 seconds. 8-10MM glass is heated at a high temperature of 700℃ for about 500 seconds and cooled for about 300 seconds. In short, according to the thickness of the glass, the time for heating and cooling is also different). after being tempered, uniform compressive stress is formed on the surface of the glass, while tensile stress is formed inside, which improves the bending and impact strength of the glass, and its strength is about 4 times that of ordinary annealed glass. The tempered glass that has been tempered can no longer be cut, ground or damaged, otherwise it will be "broken to pieces" due to the destruction of the uniform compressive stress balance.

 

How many types tempered glass has?

1. for different shape, tempered glass can be divided into flat tempered glass and curved tempered glass.

1.1. Generally, there are 12 types of thickness of flat tempered glass, including 11mm, 12mm, 15mm and 19mm,etc; curved tempered glass has around 8 types of thickness including 11mm, 15mm, 19mm,etc. The specific thickness after processing depends on the equipment and technology of each manufacturers. But curved tempered glass has a maximum arc limit for each thickness. That is the R we called usually, and R means the radius.

1.2. According to its flatness, tempered glass is divided into: superior product and qualified product. High quality toughened glass is used for automobile windshields; qualified toughened glass can be used for architectural decoration.

2. According to different tempering technology, tempered glass can be divided into physical tempered glass and chemical tempered glass.

2.1. Physical tempered glass is also called physical toughened glass. The physical tempered glass is processed through heating the ordinary flat glass in a heating furnace close to the softening temperature of glass(600℃), eliminating the internal stress through its own deformation, then removing the glass out of the heating furnace, and blowing the high pressure cold air to the glass with multi-head nozzles, which will quickly and evenly cool the glass into room temperature, then the tempered glass is obtained. This kind of tempered glass is in a stress state of internal tension and external compression. Once the local damage occurs, the stress will be released, and the tempered glass will be broken into countless small pieces. These small pieces have no sharp edges and corners and are not easy to hurt people.

All tempered glass products,like tempered glass lids for top load washing machine, tempered glass door cover for front load washing machine, refrigerator tempered glass shelf, smart control panel, tempered glass advertising billboard panel,tempered glass door panels for wine cooler, etc, are all physical tempered glass.

 

 

2.2. Chemically tempered glass is to improve the strength of the glass by changing the chemical composition of the surface of the glass, generally by applying ion exchange method for tempering. The method of chemical tempering is to immerse the silicate glass containing alkali metal ions into the molten lithium(Li+) salt, so that the Na+ or K+ ions on the surface of the glass are exchanged with Li+ ions, and the Li+ ion exchange layer is formed on the surface of the glass. 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 into the room temperature, the glass is also in the state of inner tension and outer compression. The chemically tempered glass has the similar effect to the physical tempered glass.

3. According to different degree of tempering, tempered glass can be divided into tempered glass, semi-tempered glass and super-strength tempered glass.

3.1. tempered glass: the tempered degree of tempered glass is =2~4N/cm, the surface stress of tempered glass curtain wall α≥95Mpa.

3.2. Semi-tempered glass: the tempered degree of semi-tempered glass is 2N/cm, the surface stress of semi tempered glass curtain wall 24Mpa≤α≤69Mpa.

3.3. super strength tempered glass: the tempered degree of super strength tempered glass is >4N/cm.

4. Applications of tempered glass

Once we have learned what the tempered glass is, how tempered glass is manufactured, and how many types tempered glass has, now we are going to introduce where those tempered glass products are used? And What kind of tempered glass products Huide Glass can fabricate? And where are those tempered glass products are used?

Flat tempered glass and curved tempered glass are both safety glass. Tempered glass products are widely used in doors and windows of high-rise building, glass curtain walls, indoor partition glass, lighting ceiling, sightseeing elevator passages, furniture, glass guardrails, home appliances,etc. Usually tempered glass products can be used in the following industries:

1. tempered glass products can be used for construction industry, building form-work, decoration industry(eg:glass doors and windows, curtain walls, interior decoration partition walls,etc).

2. Tempered glasses are also widely used for furniture manufacturing industry( like tempered glass tea table, tempered glass beach table, tempered glass door panel for cabinet,etc).

3. Tempered glass is also widely used in household appliance manufacturing industry(like glass screen for TV, door glass cover for oven, tempered glass cover for air conditioner, high strength tempered glass refrigerator shelves, tempered glass door cover for top-load washing machine and front load washing machines,etc).

4. Tempered glass can be used for electronic and instrument industry(like tempered glass display board for mobile phone, Mp3, Mp4, clocks and other digital products).

5. Tempered glass can be used for automobile manufacturing industry(tempered automobile window glass,etc).

6. Tempered glass can be used in daily products industry( tempered glass cutting board,etc).

7. Tempered glass can be used for special industry( tempered military glass).

After the tempered glass is broken, the fragments will be broken into uniform small particles and there is no knife-like sharp corner like the general glass, so tempered glass is called safety glass, and is widely used in automobiles, interior decoration, and windows which are open to the outside on the high buildings.

 

How should tempered glass products be packed, delivered and stored?

Package of tempered glass products

Tempered glass products should be packed by wood cartons and or container. And each piece of tempered glass product should be covered by plastic bags or paper, between the tempered glass products and the packing box, the space should be filled with light and soft materials that are not east to cause appearance defects to the tempered glass products like glass scratches. Specific requirements should comply with relevant national standards.

Packaging Mark of tempered glass products:

The packaging mark on the carton of tempered glass products should comply with the relevant national standards, and each packing box should be marked with words such as “upward, light handling, careful for breaking, thickness of tempered glass, grade of tempered glass, factory name or trademark”.

Delivering:

During transportation, the wooden box shall not be placed flat or inclined, and the length direction shall be the same as the moving direction of the delivering vehicle, and the the wooden cartons should be protected against rain.

Storage

All tempered glass products should be placed vertically and stored in a dry room.

What kind of tempered glass products Huide Glass can manufacture and where are those tempered glass products are used?

Huide Glass can manufacture tempered glass products mainly for home appliances, like high strength transparent tempered glass refrigerator shelf, tempered glass lids for top load washing machine, tempered glass door cover for front load washing machine, tempered glass refrigerator door panel, smart control panel, tempered glass advertising billboard panel,tempered glass door panels for wine cooler, etc, are all physical tempered glass.

If you have other special requirement about tempered glass products, kindly send us your detailed requirements, customization is available here. Welcome to contact our sales department for inquiry.