Abstract: The subject of the invention is a mineral wool capable of being dissolved in a physiological medium and comprising the constituents below in the following percentages by weight: SiO2 38-52% Al2O3 16-23% RO (CaO + MgO) 4-15% R2O (Na2O + K2O) 16-25% B2O3 0-10% Fe2O3 (total iron) 0-3%, preferably 0-1.5% P2O5 0-3%, preferably 0-1.5% TiO2 0-2%.

Abstract: The subject of the invention is a mineral wool composition capable of dissolving in a physiological medium which comprises the constituents below, having to the following percentages by weight:______________________________________ (CaO + MgO + BaO + Na.sub.2 O + K.sub.2 O + B.sub.2 O.sub.3) > 30* 2 .times. Al.sub.2 O.sub.3 RO 13.5 to 19.5% R.sub.2 O 14.2 to 23% RO/R.sub.2 O 0.70 to 0.95 CaO/MgO > 1.5 SiO.sub.2 47 to 58.5% Al.sub.2 O.sub.3 0 to 3.5% B.sub.2 O.sub.3 5 to 10% Fe.sub.2 O.sub.3 (total iron) 0 to 3.0% ______________________________________where:RO means oxides of the elements from column 2a of the Periodic Table, including CaO, MgO, BaO and SrO; and R.sub.2 O means oxides from column 1a of the Periodic Table, including Na.sub.2 O, K.sub.2 O and Li.sub.2 O.

Abstract: The invention relates to "two-component" inorganic fibers obtained by conjoint fiber formation from two different inorganic compositions, especially two glass compositions based on SiO.sub.2, alkali metal oxides and alkaline-earth metal oxides;the two inorganic compositions have thermal expansion coefficients .alpha. exhibiting a difference .DELTA..alpha. of at least 20.times.10.sup.7 K.sup.-1,they have a minimum viscosity temperature of fiber formation T.sub.log3 of between 830 and 1010.degree. C.,they exhibit a work range of at least 30.degree. C.,each includes, as weight percentages, in all less than 3% of the following compounds: TiO.sub.2, ZnO, BaO and Li.sub.2 O and preferably less than 1% of each of these,they exhibit, as weight percentages, differences in respective contents of boron oxides B.sub.2 O.sub.3 and of sodium oxide Na.sub.2 O such that:(i) .DELTA.B.sub.2 O.sub.3 >2%(ii) .DELTA.Na.sub.2 O>2%.

Abstract: The present invention relates to mineral fiber compositions useful for forming fibers which are readily degraded in a physiological medium such as that found within the human body. Advantageous compositions formed according to the present invention comprise the following components in the proportions by weight set forth below:______________________________________ SiO.sub.2 37 to 58 wt. %; Al.sub.2 O.sub.3 4 to 14 wt. %; CaO 7 to 40 wt. %; MgO 4 to 16 wt. %; P.sub.2 O.sub.5 1 to 10 wt. %; Fe.sub.2 O.sub.3 up to about to 15 wt. %; ______________________________________wherein the amount of CaO+MgO+Fe.sub.2 O.sub.3 is greater than 25% and the total amount of Na.sub.2 O+K.sub.2 O is less than 7%. The total iron contained within the composition is expressed in the form of ferric oxide (Fe.sub.2 O.sub.3).

Abstract: A method of forming felts, the fibers of which are disposed in random directions, by depositing the fibers which are carried by a current of gas on a gas-permeable conveyor, the fibers, prior to being deposited, being coated with a binder composition. The felt constituted on the conveyor is subjected to at least one longitudinal compression, the intensity of which is regulated in such a way that no creases form on the surface. The felts obtained are highly resistant to compression, tearing and flexion.

Abstract: The invention relates to the forming of felts, the fibres of which are disposed in random directions.These felts are obtained by depositing the fibres which are carried by a current of gas on a gas-permeable conveyor, the fibres, prior to being deposited, being coated with a binder composition. The felt constituted on the conveyor is subject to at least a longitudinal compression, the intensity of which is regulated in such a way that no creases form on the surface.The felts obtained are highly resistant to compression, to tearing and to flexion.

Abstract: The invention relates to the forming of felts, the fibres of which are disposed in random directions.These felts are obtained by depositing the fibres which are carried by a current of gas on a gas-permeable conveyor, the fibres, prior to being deposited, being coated with a binder composition. The felt constituted on the conveyor is subject to at least a longitudinal compression, the intensity of which is regulated in such a way that no creases form on the surface.The felts obtained are highly resistant to compression, to tearing and to flexion.