Cooling glass: Quickly or slowly.
We have all experienced this: When you burn your finger on a hot stove, you quickly run it under cold water. That eases the pain and is meant to reduce the degree of the burn – it is meant to accelerate the cooling process.
The only problem with this is that it achieves exactly the opposite because it encapsulates the heat. In a way, the same applies to glass.
When glass enters the cooling phase, it is crucial how quickly or slowly the glass cools down because cooling creates tensions. Depending on the method, a high level of surface tension is generated in the glass because rapid cooling cools down the top layer first.
The heat on the inside is retained for longer. It is encapsulated. This brings us back to the heat which can become encapsulated in human tissue.
Of course it is not just one single factor that determines the time frame for the glass cooling process. The intended use of the glass – the glass type – is important. The thickness of the glass also plays a role.
As a rule, experts say that glass cools down within half an hour to 100 minutes. That is quite a good time for a solid, but it is due to the fact that glass has poor heat retention properties. By the way: Fast cooling creates higher impact strength of the finished glass.