Drawing glass at high speed, in order to obtain fine filaments, requires a batch composition which is a compromise. The elements of the compromise are, as usual, technical (mechanical properties, colour, RI, solubility, chemical behaviour etc) and economical. Glass used in the "reinforcement" sector (now called "composites" is mostly "E" glass. Thanks to the technical evolution during the last 60 years or so, many improvements have been made. More recently, less than 10 years ago, another driver appeared to take more and more importance: the necessity to protect the environment. This has led to new glass formulations, & to more sophisticated production processes. Owens Corning recently introduced on its market a new & environmentally friendly fibre glass composition called "Advantex". This glass is no longer defined by its composition, but by its properties.
