Description
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 involves draining the molten glass through platinum dies which have orifices of 1-2 mm in diameter.
Viscous glass drops are thus formed, which are kept at a high temperature, which are stretched mechanically to form filaments wound around drums rotating at high velocity.
Discontinuous filament textile glass - glass staple - is produced today, using the latest procedures, by spraying the thread of molten glass which comes out of the die with overheated steam. The glass filaments thus produced are channelled and wound around rotating drums and then unravelled to different lengths. Textile glass, both continuous and discontinuous, has a diameter which varies from 3 to 8 micrometres.
The mechanical effect of the stretching and winding is not sufficient to keep the filaments united in a long-lasting way, in a single thread or in a fibre ribbon. The glass is too smooth to be agglomerated; also, it is sensitive to friction, abrasion and static electricity, which are phenomena which run the risk of increasing when we proceed to the weaving or other transformation procedures. Because of this, as the filaments come out of the die, they are softened and coated with thin films of organic compounds (dressings). The aims of the protective covering, which is thus formed on the surface, are to:
- agglomerate the filaments when they are twisted to form a single thread;
- cover them with a lubricating film;
- support the adherence between the glass and the synthetic resins in the production of glass-resin objects.
Yarn and glass fabrics are valued highly due to their high strengthening and isolation properties; large quantities are produced for various industrial sectors.
They can also be used in the production of fabrics for furnishings, upholstering, curtains, cinema screens etc..
But studies on the uses of glass fibres are far from over; different combinations with other yarns have been recently experimented to obtain fabrics of exceptional sturdiness, non-creasingness and resistance to wear and tear.
Fibres of a particular composition (bioglass) are used as biocompatible materials. In all its various forms, glass fibre is the best strengthener of 'composites'. These objects, in synthetic resin and glass fibre, are used widely and are becoming increasingly more important.
Some of the most well-known objects in glass resin are: bumper-bars and other important automobile bodywork parts (prototypes of automobiles with bodies made entirely of glass resin are already on the market), boat hulls, sporting goods etc..
Of particular importance is its use in the aeronautical and railway industries.