Aug.2023 09
Views: 114
Why do some glasses crack when it is poured with boiling water?
Details
"First of all, not all glasses will break when exposed to boiling hot water. But why do some glasses break?
In the past, when buying a glass, the salesperson would tell you whether it was a hot water glass or a cold water glass. Cold water glasses are the ones that break when exposed to scalding hot water; hot water glasses don't. But the glasses I'm in now should all be hot water cups. Especially in China, we all use glasses to make tea, so is it a good thing that the glass cannot touch hot water? The highest temperature of water under one atmospheric pressure is 100 degrees Celsius, in our daily life, we will not have water over 100 degrees.

If thermal expansion and contraction were the only reason, then all glasses would break when exposed to scalding hot water. This is not the case.
Therefore, heat expansion and contraction are part of the reason. In the process of manufacturing glass, there is no proper treatment, and the glass is not made correctly, which is also a very important reason. As long as the thermal expansion coefficient of the glass is relatively small, and the heat transfer coefficient is relatively large, the glass will not break. If the glass can be tempered, it will not break.

According to the technology of the modern glass industry, a glass that breaks when exposed to hot water is a manufacturing problem, not an unchangeable physical phenomenon. "