Are thick glass cups more dangerous than thin ones

Many people are unsure whether to choose a thick or thin glass when customizing glasses. This is because many people have learned a knowledge during school, which is thermal expansion and contraction, so they are worried about whether the cup is too thin and easy to crack. So when customizing cups, would you choose thick or thin ones?

I believe many people have encountered this situation where the glass suddenly bursts when hot liquid is introduced into it. This kind of unexpected event often makes us feel that the cup is too thin, and choosing a thick cup is not accidental. Is it really safe to choose thick glassware?

When we pour hot water into a cup, it is not immediately that the entire wall of the cup comes into contact with the hot water, but rather that it becomes hot from the inside out. When hot water enters the cup, the inner wall of the cup first expands. However, due to the time required for heat transfer, the outer wall cannot feel the temperature of the hot water for a short period of time, so the outer wall does not expand in time, which means there is a time difference between the internal and external expansion, resulting in the external wall bearing enormous pressure caused by the expansion of the inner wall. At this point, the outer wall will bear the enormous pressure generated by the expansion of the inner wall, equivalent to a pipe, and the objects inside the pipe will expand outward. When the pressure reaches a certain level, the outer wall cannot withstand the pressure, and the glass cup will explode.

If we carefully observe a broken cup, we will find a pattern: thick walled glass cups are not only prone to breakage, but thick bottomed glass cups are also prone to breakage.

So, obviously, to avoid this situation, we should choose a cup with a thin bottom and thin walls. Because the thinner the glass cup, the shorter the heat transfer time between the inner and outer walls, and the smaller the pressure difference between the inner and outer walls, it can almost expand simultaneously, so it will not crack due to uneven heating. The thicker the cup, the longer the heat transfer time, and the greater the pressure difference between the inner and outer walls, it will crack due to uneven heating!

Post time: Feb-29-2024

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