Experiments tell you under what conditions tempere

  • Detail

On July 12 this year, the tempered glass in the hall of a teaching building in Chongqing University of technology suddenly exploded for no reason, but fortunately no one was injured

on July 12 this year, the tempered glass in the hall of a teaching building in Chongqing University of technology suddenly exploded for no reason, but fortunately no one was injured

on June 28, when an office building in Shenzhen was under construction, the 4-square-meter tempered glass curtain wall suddenly burst, causing four workers to be injured

at the same time, a piece of tempered glass in the window of a resident's home in Nanhuan new village, Jiangsu Province, also exploded without cause

put many accidents together, they all have one thing in common, that is, the self explosion of tempered glass mostly occurs in summer

why? What is the relationship between self explosion and temperature? Let's do an ultimate high temperature test of tempered glass

in dog days, the maximum temperature of glass directly exposed to the sun is about 65 ℃

our experiment uses qualified tempered glass, which is 1.5m long, 1m wide and 10mm thick. Usually, the curtain wall of office buildings also uses tempered glass of this thickness

Dashi first hit the tempered glass with a hammer, and the glass was intact

then start baking glass with a spray gun

although there is no flame when the temperature rises to 180 ℃, bursts of heat waves rush towards Dashi

the tempered glass has been baked under Dashi's spray gun for more than 10 minutes, and the glass temperature has reached 300 ℃, but there is no problem with the glass

the highest temperature recorded by the thermal imager is 301 ℃, which has completely exceeded the normal temperature of the sun

this means that exposure to the sun will not cause the tempered glass to self explode

then there is another saying that the self explosion of tempered glass is caused by the bright sunshine outdoors and the cool wind swishing when the air conditioner is turned on indoors

Dashi continued to bake this glass, and then poured it directly up with cold water

300 ℃ under high temperature, the tempered glass only emitted a little smoke when encountering cold water, and did not burst

Lvjinyun, the quality director of Dingsheng technology, said that tempered glass should be calcined at a high temperature of 620 to 640 ℃ in the tempering furnace and then cooled sharply. After special process treatment, the general temperature will not lead to the self explosion of tempered glass

the root cause of self explosion of tempered glass depends on the original sheet, because the original sheet itself contains impurities nickel sulfide. The more impurities and bubbles, the higher the self explosion rate

next, continue the experiment with low-quality tempered glass with obvious impurities. The temperature of tempered glass increased by 200 ℃. Pour cold water on the glass. When the cold water touches the glass, the whole glass breaks and collapses to the ground in less than 2 seconds

Lock Yingqiao, the production director of Dingsheng technology, said that there were sulfide stones in this glass raw material. After the cold and hot expansion of the experiment, the sulfide stones caused microcracks in the glass, which led to the self explosion of the glass

uneven cooling and heating is the inducement of self explosion of tempered glass, and the fundamental reason is that the glass quality is not up to standard. There are impurities in the original glass. Affected by the temperature difference, the stress of the whole glass will be changed and self explosion will occur

in addition to excessive internal impurities, design and construction are also related to glass self explosion

two pieces of tempered glass, with the same size and thickness, are qualified products after inspection

one piece does not do any treatment

the other piece strengthens the four corners, three loose and one tight, to see if there is any difference in the firmness of the glass

when installing reinforced tempered glass, it is required to bear the force evenly around. However, Dashi deliberately tightened the screws in one corner to simulate improper construction

the toughened glass without any treatment did not break under many times

the two hammers of the toughened glass with screws broke

therefore, the toughened glass that looks very strong and durable will become very fragile as long as the stress structure changes

modern glass production technology can not completely eliminate the existence of nickel sulfide impurities. Summer is the season when curtain wall components are most prone to deformation. Under multiple reasons, tempered glass is prone to self explosion

according to the regulations of China's "technical program for application of architectural glass", laminated glass must be used for curtain walls with an overhead surface of more than 3 meters. Laminated glass is a layer of glue in the middle, which will not fall off even if it explodes, and it is very safe. If you see the self explosion and falling of tempered glass in a high-rise building, it must be cutting corners

transferred from curiosity laboratory

warm tips for hammus doors and windows:

clear CCC marks and numbers, specifications, technical conditions, and enterprise names must be on the glass




Copyright © 2011 JIN SHI