How do clay teapots/plates and clay pans work, how does the the tea/liquid not soften it up or make it all clumpy? And how does the heat not make it burn or catch fire?
In: 6
Ceramics aren’t just made of dried clay. They’re heating to extremely high temperatures (several thousand degrees) in a kiln. This doesn’t just dry out the clay, it actually permanently changes the crystalline structure of the clay to make it hard. This process can’t be reversed. Think of when you paint a wall in a house. Once the paint is dry, you can’t make it wet again by getting the wall wet, right?
So the kiln firing process permanently hardens the clay and changes its crystalline structure so that it become permanently hard.
Hot liquids can’t melt ceramics or set them on fire because, again, once they’ve been through the kiln, their structure is changes so that they become vitrified, with glasslike properties. They have extremely high melting temperatures – far higher than boiling water. The only way melt a ceramic is to put it back in a kiln and heat it up to several thousand degrees.
We also coat ceramics in a glaze. When we put the ceramic piece in the kiln, the glaze gets so hot it partially melts and essentially turns into a thin, impermeable glass layer.
Latest Answers