Molten glass properties from "summary" of Glass Chemistry by Werner Vogel
Molten glass has many unique properties that make it incredibly useful, from its heat resistance to its ability to be molded into a variety of shapes. Understanding these properties can help us use and control molten glass in a variety of ways.- No matter how you play with the shape, colour or texture of a molten glass object, when it is cooled down it creates a complete distribution of unique features such as transparency, durability, and workability.
- Molten glass has an interesting make-up which gives it its unique properties and characteristics. Its principal components are two oxides: silica (an oxide of silicon) and alumina (aluminium oxide). This combination of materials, when heated together to a temperature above 2000°F, result in a liquid that can be shaped into a variety of forms.
- When molten glass comes into contact with cooler material, its heat conduction is excellent compared to other materials. This means that very little energy is lost through heating and cooling processes but at the same time, care must be taken to ensure glass does not reach a shocking level of heat - something any expert glass blower will have experienced.
- While taking its physical form, molten glass provides warm esters and optical brilliance with no spots, streaks and other abnormalities. It also does not react chemically with other materials, thus has low spontaneous oxidation.
- At high temperatures, molten glass flows like water but cools quickly and solidifies into all manner of structures. A special property is vitrification: reduction of the atomic spacing below the original component substances, preventing recrystallisation on cooling.
- Moreover, because of its relatively high resistance to stress and thermal shock, molten glass can be used in places where there are extreme environment conditions. As it ages gracefully, it needs less maintenance to remain lustrous.
