How to solve the upward bending of tempered flat glass?

When the glass is heated, there is a temperature difference between the upper and lower surfaces to cause glass deformation.

Toughened glass. The plate side is bent upward.

Reason: This phenomenon is due to the fact that after the glass is heated in the heating furnace, the temperature of the upper surface of the glass is higher than the temperature of the lower surface, and the glass that maintains this temperature state enters the cooling chamber for cooling, and during the cooling process, when the cooling temperature and wind pressure of the upper and lower surfaces of the glass occur.

Solution: In this case, the temperature at the bottom of the furnace can be increased to minimize the temperature difference between the upper and lower surfaces of the glass.

The tempered glass plate is bent downward.

Reason: This phenomenon is due to the fact that after the glass is heated in the heating furnace, the temperature of the lower surface of the glass is higher than the temperature of the upper surface, and the glass that maintains this temperature state enters the cooling chamber for cooling, and in the cooling process, when the cooling temperature of the upper and lower surfaces of the glass is the same as the wind pressure, due to the high temperature of the lower surface of the glass, the shrinkage of the lower surface after cooling is greater than that of the upper surface, and the phenomenon of bending and deformation of the glass plate facing down will occur (as shown in Figure 2).

Solution: In this case, the temperature at the bottom of the furnace can be reduced to minimize the temperature difference between the upper and lower surfaces of the glass.

Reason 2 for the poor flatness of flat tempered glass

When the glass is heated, there is a temperature difference between the middle and the edges of the glass, which causes the glass to deform.

Reason: After the glass is heated in the furnace, if the temperature of the middle part of the glass is higher than the temperature of the edge, then during the cooling process, the shrinkage of the middle part of the glass with higher temperature will be greater than the shrinkage of the edge with lower temperature. When the glass is cooled to room temperature, the size of the edge of the glass will be larger than the size of the middle part, and a large compressive stress will be formed on the edge of the glass, resulting in the phenomenon of bending and deformation of the glass plate face downward (as shown in Figure 2).

Similarly, after the glass is heated in the heating furnace, if the temperature of its edge is higher than the temperature of the middle part, then in the cooling process, the shrinkage of the middle part with higher temperature on the glass will be greater than the shrinkage of the edge with lower temperature, and when the glass is cooled to room temperature, the size of the middle part of the glass will be greater than the size of the edge, and a large tensile stress will be formed at the edge of the glass, so that the phenomenon of bending and deformation of the glass plate face upward (as shown in Figure 1).

Solution: The above two situations can be solved by adjusting the local heating temperature parameters of the tempering furnace or changing the arrangement of the filling.

Three reasons for the poor flatness of flat tempered glass

Random temperature distribution caused by uneven glass deformation.

Reason: The uneven distribution of random temperatures is mainly caused by the poor state of the equipment. The heating wire of the tempering furnace has local damage and the temperature sensor.

The change or distortion of the position of the glass, and the unreasonable stacking of the glass on the roller table will cause the glass to be heated unevenly. This random uneven temperature distribution will lead to uneven temperature distribution in the direction of the glass surface after heating, and irregular and irregular shrinkage of the glass in different areas when cooling, which will directly lead to the local flatness of the glass surface.

Solution: In this case, the enterprise can solve it by formulating a reasonable equipment maintenance and loading system.

There are several factors for tempered glass to bend upwards:

1. When the lower part of the glass is cooled out of the furnace, the cooling speed is slow or the wind pressure is small, and the solution is to make the lower cooling air grid too high or raise the upper air grid.

2. The upper part of the furnace is heated at a high temperature, and the solution is to reduce the upper part temperature or increase the lower part temperature or extend the heating time.

3. Other factors such as glass material, heating environment, silk screen printing high-temperature ink tempering and other factors. Increase the temperature of the lower part of the furnace, or lower the temperature of the upper part of the furnace.

Increase the air pressure in the upper part of the wind grid in the tempered section to reduce the thermal balance.

Priority is given to the method of adjusting the wind pressure, and if it is ineffective, the method of adjusting the temperature is used.

Tempered glass reinforced glass is a type of safety glass. Tempered glass is actually a kind of prestressed glass, in order to improve the strength of the glass, chemical or physical methods are usually used to form compressive stress on the surface of the glass, and the glass first counteracts the surface stress when it bears external force, thereby improving the bearing capacity and enhancing the wind pressure resistance, cold and heat resistance, impact and so on. Note the difference with FRP.

The deformation of tempered glass mainly comes from the beauty side; The first is the accuracy of the roller table, and the second is the uneven stress.

The first point is that the tempered glass flatness is poor due to problems in the roller table.

The second point is thermal deformation caused by uneven heating temperature.

The third point is thermal deformation caused by uneven cooling.

According to what you said, there is a problem with your air grille, which needs to be adjusted as a whole, and your air nozzle is blocked and needs to be cleaned and poked open. If possible, the equipment will be leveled (leveled) as a whole. In addition, check whether the furnace wire has been replaced with a new furnace wire of different power, resulting in uneven heating.

Hope it helps.

Phenomenon: Concave bending of tempered glass.

Causes: 1. The temperature of the upper part of the heating furnace is too high; 2. The wind pressure in the upper part of the tempered section is too low.

Treatment method: 1. Increase the temperature of the lower part of the heating furnace, or reduce the temperature of the upper part of the furnace; 2. Increase the wind pressure at the upper part of the wind grid of the tempered section; 3. Reduce thermal equilibrium.

Note: The method of adjusting the wind pressure is preferred, and if it is invalid, the method of adjusting the temperature is used.

Phenomenon: Convex bending of tempered glass.

Causes: 1. The temperature of the lower part of the heating furnace is too high; 2. The wind pressure in the lower part of the tempered section is too low.

Solution: 1. Reduce the temperature under the furnace or increase the upper temperature; 2. Increase the wind pressure at the lower part of the wind grid; 3. Increase thermal balance.

Note: Similarly, the method of adjusting the wind pressure is preferred, and if it is ineffective, the method of adjusting the temperature is used.

If it is pasted on a mobile phone, it may not look good after it is pasted, so you can consider changing it. Or flatten it and stick it again.

1. Upturning: Reason: When the glass is out of the oven, the temperature of the upper surface of the glass is higher than the temperature of the lower surface, the temperature of the upper surface of the glass is too high and the loss is fast, the temperature of the lower surface is low and the loss is slow, and the upper wind pressure is lower than the lower wind pressure at the wind grid.

Solution: Increase the temperature of the bottom of the furnace, appropriately reduce the upper temperature, if the furnace temperature is stable, you can adjust the pressure of the air grid, and make the upper pressure greater than the lower pressure when the height of the nozzle is unchanged. 2. Downbend:

Reason: When the glass is out of the oven, the temperature of the lower surface of the glass is higher than the temperature of the upper surface, the temperature of the lower surface of the glass is too high and the loss is fast, the upper surface temperature is low and the loss is slow. Workaround:

If the furnace temperature rises steadily, the pressure of the air grid can be adjusted, and the lower pressure is greater than the upper pressure when the nozzle height remains unchanged.

1. Protect the corners of the tempered glass, if the corners of the tempered glass are damaged, then the risk of self-explosion of such tempered glass is multiplied. Because the stress points of the tempered glass are all concentrated in the corners, the corners of the tempered glass must be protected, and the corners of the tempered glass must be used with caution when the corners of the broken tempered glass cannot be treated.

2. Pay attention to avoid uneven cold and heat, as mentioned above, the internal stress points of tempered glass are all concentrated in the edge part. If a piece of glass is subjected to high and low temperatures at both ends in extreme conditions, 90% of the glass will explode on its own, for example, if you pour cold water on a lit incandescent lamp, the glass of the incandescent lamp will break.

The tempered glass big glass is bent on one side, and it is not bent on the other, and the small glass is better, what's going on?

Dear, hello, I'm glad to answer for you: Tempered silver glass big glass on one side of the S bend, on the other hand is not bent, the small glass is better to serve Hu Qing, what's going on? Answer: In the process of tempered glass, the curvature may be different due to the poor level of the equipment, the different wind pressure around the high-pressure section, the uneven heating of the glass, and the blockage of the tuyere.

Solution: 1. Check the track level and calibrate it (1mm) 2. Adjust the height of the nozzle left and right in the high-voltage section 3. Check the working current of the thermocouple and the heating furnace wire 4. Check whether the nozzle is blocked, I hope my nozzle is helpful to you, I wish you a happy life, if my is helpful to you, I hope you can give a 5-star like. Thank you for your support.

It is the same material as ordinary glass, but the ordinary glass has been tempered, and the so-called tempering treatment is to heat the ordinary glass to the melting point, and then put it in a constant temperature environment to cool it slowly, and it becomes tempered glass.

I can't help it.

If it's a desktop, you can consider turning it over. After a while, it will be restored. If it's a large area, there's no way.

How to solve the problem of upturned glass in the middle when the tempered glass is out of the oven! Hello, I am glad to answer the <> reasons for you: when the glass is out of the oven, the temperature of the upper surface of the glass is higher than the temperature of the lower surface, the temperature of the upper surface of the glass is too high and the loss is fast, the temperature of the lower surface is low and the loss is slow, and the upper wind pressure is lower than the lower wind pressure at the wind grid.

Solution: If the furnace temperature is stable, the pressure of the air grid can be adjusted, and the upper pressure is greater than the lower pressure when the nozzle height remains unchanged. The wide transparent glass absorbs heat quickly, and the middle heat absorption is slow to cause upturning, so the convection in the furnace should be increased and the convection time should be extended.

The concave operation of coated glass low-e glass in the tempering furnace is also caused by the inconsistency of the heating rate of the upper and lower parts, and there is a certain solution effect by adjusting the convection in the furnace. The concave operation of the glass in the furnace for a short time has no effect on the tempering quality of the glass, but if the operation is done for a long time, the contact surface of the glass and the roller table will form a foggy white road, and the solution is only to improve the heating state in the steel clearance furnace and make the glass as uniform as possible. Hope mine can help you <>

Do you have any other questions?

Hello, tempered flat glass bending upwards can be solved by the following methods1Reheating: Increase the tempered temperature sensitivity group appropriately, make the tempered flat glass soft again, strengthen the downward bending of the tempered glass, and avoid glass cracking caused by excessive temperature.

2.Cool again: Manage the temperature and cooling time, so that the glass can recover smoothly downward during the natural cooling process, and pay attention to avoid other problems caused by too fast or slow cooling time.

3.Replace the glass with a new one: If the above methods do not solve the problem, it is recommended to make a new tempered flat glass.