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: Fibers are drawn out by maintaining a temperature gradient between the interior and exterior walls of the peripheral band of a centrifuge. The peripheral band is made from a material having a thermal conductivity below 20 Wm.sup.-1 C.sup.-1 at 1000.degree. C. Application to the drawing out of fibers from glasses having a working range less than 100.degree. C. wide.

Abstract: Process for making a cement mixture containing fibers wherein a paste is formed by mixing cement and, per 100 parts by weight of cement, approximately 5 to 20 parts by weight of a first pulverized material of which the grains have an average diameter of between 1/5 and 1/10 of the average diameter of the grains of the cement and approximately 20 to 35 parts by weight of water. The paste is then mixed with reinforcing fibers. The paste may also include a second pulverized material the average grain diameter of which is between 1/5 and 1/10 of the average diameter of the first pulverized material. The invention further includes products made from a cement mixture manufactured according to one of the foregoing processes.

Abstract: Fibres, particularly glass or rock wool fibres coated with a modified polyvinyl alcohol-based polymer and suitable for use as a base material to produce a surface coating on a backing by a simultaneous spraying of the coated fibres mixed with water and a cross-linking agent. A method of producing the fibres to make them suitable to be sprayed in the manner described is also provided.

Abstract: Fibres, particularly glass or rock wool fibres coated with a modified polyvinyl alcohol-based polymer and suitable for use as a base material to produce a surface coating on a backing by simultaneous spraying of the coated fibres mixed with water and a cross-linking agent. A method of producing the fibres to make them suitable to be sprayed in the manner described is also provided.