Molten glass lends itself perfectly to be easily stretched into continuous filaments or short fibres (staples or glass wool): this has been known since its invention. Despite this, the production of glass fibres is the only type which does not have craftsman origins. The reason is very simple if you consider that, in the transformation of one kilogram of glass fibres with a diameter of 1 micrometre, over 4,000 km of glass thread is obtained.
To produce these fibres whose characteristics are resistance to traction, elasticity, dimensional stability and corrosion, or, by contrast, soluble, we start with glass with particular chemical-physical characteristics.
Those most used are:
- E glass (calcium alluminoboronsilicate), used for continuous fibre, due to its dielectric properties and its high chemical resistance.
- C glass (sodium and calcium boronsilicate), used for isolation, soluble in particular conditions and thus non-toxic.
The vitrifiable mixture is melted at a high temperature (about 1400°C ), made homogenous and then refined until all the glass bubbles and impurities have been completely removed. To obtain further homogeneity and refinement, the molten glass is transformed into small marbles and then re-melted; any impurity would in fact lead to the breaking of the fibres and the halting of the production. This molten glass is finally stretched at a great speed and is transformed into continuous filaments or short fibres.
Textile glass is worked as a continuous multithread filament or as a discontinuous filament, that is, a staple, which is easily spinnable.The start of production of a continuous filament …
Glass wool or rock wool
Material consisting of fibrous mass, similar to cotton wool, obtained through the action of violent blasts of air on cast glass or molten puffy material (basalt).Fibres which are made up of …
A particular type of glass fibre is the so-called fibre optic, which is used as a light guide. If a large number of very thin fibres are put together (the diameter is about 0.13 mm), so as …