Aluminosilicate glass
5-15 usd/kgAdding alumina (Al2O3) to silica glass – in combination with modifying cations (positively charged ion), such as alkaline earth or rare earth oxide – leads to a glass with improved mechanical, optical and thermal properties. There are several different types, which are categorised according to their physio-chemical properties, and many of which are not in large-scale production. Well-known trade name examples include Gorilla, Xensation, Dragontrial and Dinorex. While the price for plain aluminosilicate is not so much – alumina is not an expensive ingredient – the chemical strengthening process adds considerable time and cost to the finished part.
Unlike float glass, which is limited to 0.4-25 mm thick, aluminosilicate cover glass is produced by the vertical fusion process in-air, allowing thicknesses down to 50 microns or so, with a perfect finish. As with glass fibres, the higher aspect ratio of thinner glass allows it to be very flexible.