Which type of glass is made by cooling glass slowly to relieve internal stress?

The type of glass that is made by cooling glass slowly to relieve internal stress is known as annealed glass. The process of annealing involves heating the glass to a high temperature and then gradually cooling it in a controlled manner. This slow cooling allows any residual stresses that may have occurred during the glass manufacturing process to be evenly distributed, resulting in a more stable and uniform product.

Annealed glass is typically used in applications where safety and strength requirements are not as stringent, as it is less resistant to breakage compared to other types of glass. Its properties make it suitable for applications like glazing or decorative purposes, where the risk of shattering upon impact is lower.

In contrast, tempered glass undergoes a more rapid heating and cooling process, which significantly increases its strength but introduces a different set of stress distributions. Heat-strengthened glass, while more robust than annealed glass, does not attain the same level of strength as tempered glass and also relies on controlled heating and cooling but not to the same extent. Laminated glass, on the other hand, consists of multiple layers of glass bonded together with a durable interlayer for safety mechanisms, rather than being about the stress relief in a single piece of glass through slow cooling.