Glass fibres are long thin fibres made of glass. bestehen. Glass fibres are extruded from the glass melt. They are used in glass fibre cables for data transfer, as textile fibres for heat and noise insulation, and as filler material in plastics to reinforce a material and make it dimensionally stable. Glass fibres for reinforcement can be short (millimetre range), long (up to several centimetres) or endless fibres. Glass fibres may be added to plastics in proportions of up to 70% by weight. The adhesion between the fibres and the plastic matrix is of decisive importance for the performance of the reinforced plastic. It can be improved by plasma treatment of the glass fibres. The surfaces of glass fibre reinforced plastics can be etched in the plasma so as to expose the fibres for analysis or to pre-treat the plastic before bonding.