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The Flatness Of Tempered Glass And The Solution Summary
Oct 26, 2017

One of the reasons why the flatness of flat tempered glass is bad:

Glass deformation is caused by temperature difference between the upper and lower surfaces during heating.

① tempered glass plate face upward bending.

Reason: This phenomenon is because the glass is heated in the heating furnace, when the temperature on the surface of the glass is higher than that of the lower surface, the glass which keeps the temperature state cools into the cooling chamber, and during the cooling process, when the cooling temperature of the glass upper and lower surface and the wind pressure are the same, the surface temperature of the glass is high, The shrinkage of the upper surface after cooling is greater than that of the lower surface, and the deformation of the glass plate facing the upper bending is observed.

Scheme: This kind of situation can increase the temperature of the bottom of the heating furnace and reduce the temperature difference of the glass upper and lower surface.

② tempered glass plate face downward bend.

Reason: This phenomenon is because the glass is heated in the heating furnace, the glass under the surface of the temperature above the surface of the temperature, keep the temperature of the state of the glass into the cooling chamber cooling, during the cooling process, when the glass upper and lower surface cooling temperature and wind pressure, and other conditions are the same, due to the glass surface temperature is high, The shrinkage of the lower surface after cooling is larger than that of the upper surface, and the deformation of the glass plate facing down bending is observed.

Scenario: This can reduce the temperature at the bottom of the heating furnace and minimize the temperature difference on the upper and lower surface of the glass.

The reason why the flatness of the flat tempered glass is bad two:

Glass deformation is caused by temperature difference between the center and the edge during heating.

Reason: Glass in the heating furnace after heating, if the middle part of the temperature is higher than the edge of the temperature, then in the cooling process, glass on the middle of the higher temperature of the contraction, will be greater than the temperature of the lower side of the contraction. When the glass is cooled to room temperature, the side size of the glass will be larger than the size of the middle part, forming a larger compressive stress on the edge of the glass, and thus the phenomenon of bending deformation of the glass plate facing down.

Similarly, if the glass is heated in a heating furnace, if the temperature of the edge is higher than the temperature of the middle part, then in the cooling process, the high temperature of the middle part of the glass shrinkage will be greater than the temperature of the lower side of the contraction, 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, A larger tensile stress is formed on the edge of the glass, which causes the bending deformation of the plate.

Scheme: The above two cases can be solved by adjusting the heating temperature parameters of the tempering furnace or changing the arrangement of the pieces.

The reason why the flatness of the flat tempered glass is not good three:

Random temperature distribution caused by uneven glass deformation.

Reason: The uneven distribution of temperature is mainly caused by the poor equipment condition. The heating wire of tempering furnace has local damage, the position of temperature sensor is changed or distorted, the stacking of the glass on the roller is unreasonable, etc. will make the glass heated unevenly. The uneven temperature distribution will cause the uneven temperature distribution in the plate direction after glass heating, and the irregular and irregular shrinkage of glass in different areas when cooling, which leads to the poor local flatness of the plate surface.

Plan: This kind of situation, the enterprise may through the establishment reasonable equipment overhaul, the installation piece system solves.





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