Patent ID: 6156683
Filing Date: 2000-12-05
Classification: C03C

Abstract:
A product comprising man-made vitreous fibres formed of a composition which includes, by weight of oxides, SiO.sub.2 36 to 55% Al.sub.2 O.sub.3 15 to 30% CaO 3 to 30% MgO 5 to 20% FeO 4 to 15% Na.sub.2 O + K.sub.2 O 1 to 12% TiO.sub.2 0 to 6% Other Elements 0 to 15%  and in which the ratio Si.sup.4+ to Si.sup.4+ +Al.sup.3+ is below 0.67and the composition has a viscosity at the liquidus temperature of above 300 poise and a liquidus temperature below 1300.degree. C.and the fibres have a dissolution rate of at least 20 nm per day when measured at a pH of 4.5.