Special Glass
Mario Moretti
In addition to types of glass produced in large industrial firms, other types, which we call 'special', are available on the market. They are used in fields which are different based on their application - from those already discussed, like flat glass and hollow ware glass.
Coloured glass
Various types of colouring of glasses are described in: 'Mixtures, furnaces, fusion'.
Opaque glass
In glass used most commonly in the lighting and home-goods sector or objects for artistic use, opaqueness is due to the presence of various calcium fluoride, sodium fluoride and fluorosilicate micro-crystals in the glass, which form due to the presence of a fluorine level of 4-5% in the glass which enables the development of opaqueness during the cooling of the glass during the forming phase.
Alternatively, recourse can be made to other opacifying composites like titanium dioxide, zirconium dioxide and tin, calcium fluo-antimoniates, lead arenate and calcium phosphate.
Glass for Eyewear
All glass used in the production of optical devices belong to this group.Glass for lensesBy convention, glass for lenses is divided in Crown glass and Flint glass, the first are sodium …
Glass transmitting UV and IR rays
Glass which has the property of changing colour, in varying intensity, when it is exposed to different types of rays, belong to this group.Photosensitive glassThis is silicate glass in …
Refractory Glass
This is glass with an annealing temperature which is higher than that of normal glass and always not lower than 700°C.Silica glassThis is one of the most refractory glasses known and is …
Multiform Glass
These are small, glass objects produced with a 'multiform' process which consists in compressing fine glass powder, with the addition of an organic binder, in a metallic mould before …
Glass for various uses
In the field of materials for thermal and acoustic isolation, a particular type of glass called multi-cellular glass or foamed glass is used. It has a structure of very small pores, …
Ceramic-glass
Ceramic-glass is much more resistant than normal glass. In the molten state it is worked and shaped like any glass, but during cooling it undergoes a particular thermal treatment which leads…
Bio-glass
This is glass whose chemical composition is very similar to that of bone tissue.This characteristic has led to its use in orthopaedics as an implant material; the biocompatibility of this …