The invention relates to an uncured thermal and/or sound insulation product, based on mineral wool, advantageously on glass wool, that is in the form of a ply comprising a mineral wool layer sized by at least one binder, said sized layer having: a surface density, or basis weight, of less than or equal to 350 g/m.sup.2, preferably less than or equal to 300 g/m.sup.2, or less than or equal to 250 g/m.sup.2, and, optionally, greater than or equal to 200 g/m.sup.2, a micronaire of at most 3 under 5 grams, preferably of at most 15 l/min, better still of at most 12 l/min, and of at least 9 l/min, and the ply having a thickness of greater than 10 mm, or greater than or equal to 15 mm, or even greater than or equal to 25 mm. The invention makes it possible to propose a thermal and/or sound insulation product that is lighter while retaining satisfactory thermal and/or sound insulation properties and a good mechanical strength.

A process for forming mineral fibers by internal centrifugation using a device including a basket and a fiberizing spinner suitable for rotating jointly about an axis of rotation, the basket including an annular wall pierced by orifices and the fiberizing spinner including an annular wall pierced by orifices, the process including feeding the basket with material to be fiberized at a temperature T.sub.a; centrifuging the material to be fiberized by joint rotation of the basket and of the fiberizing spinner. The factor F is greater than 2000, the factor F being defined by F=μ.sub.adN/Q; wherein μ.sub.a is the viscosity of the material to be fiberized at the temperature T.sub.a; d is the distance between the annular walls of the basket and of the fiberizing spinner; N is the number of orifices of the basket; and Q is the feed flow rate of the material to be fiberized.

An alloy contains the following elements, the proportions being indicated as percentage by weight of the alloy (limit values included): Cr 20 to 35%, Fe 0 to 6%, W 3 to 8%, Nb 0.5 to 3%, Ti 0 to 1%, C 0.4 to 1%, Co 0 to 3%, Si 0.1 to 1.5%, Mn 0.1 to 1%, the remainder consisting of nickel and unavoidable impurities.

The invention relates to a method and facility for manufacturing a cross-linked fiberglass material, in which melted glass is produced in a melting furnace heated via combustion of a fuel with an oxygen-rich oxidant. The melted glass is converted into glass filaments, the filaments are bonded, a sheet is made from the bonded filaments, and the sheet is then cross-linked. The fumes from the melting furnace are used to preheat a combustion reagent in two steps: a first step in which air is heated via heat exchange with the fumes, and a second step in which the combustion reagent is preheated via heat exchange with the hot air. The air is then used in the cross-linking step of the method for converting the melted glass into a fiberglass material.

The invention relates to a method and facility for manufacturing a cross-linked fiberglass material, in which melted glass is produced in a melting furnace heated via combustion of a fuel with an oxygen-rich oxidant. The melted glass is converted into glass filaments, the filaments are bonded, a sheet is made from the bonded filaments, and the sheet is then cross-linked. The fumes from the melting furnace are used to preheat a combustion reagent in two steps: a first step in which air is heated via heat exchange with the fumes, and a second step in which the combustion reagent is preheated via heat exchange with the hot air. The air is then used in the cross-linking step of the method for converting the melted glass into a fiberglass material.

A mineral fiber forming device including: a centrifuge configured to rotate about a rotation axis, the centrifuge including an annular wall pierced by a plurality of orifices, the axis of symmetry of the annular wall being the rotation axis; a first annular inductor configured to heat a top part of the annular wall; a second annular inductor configured to heat a bottom part of the annular wall. The device makes it possible to increase its energy efficiency and very greatly reduce, even cancel altogether, its carbon dioxide emission level.

A mineral fiber forming device including: a centrifuge configured to rotate about a rotation axis, the centrifuge including an annular wall pierced by a plurality of orifices, the axis of symmetry of the annular wall being the rotation axis; a first annular inductor configured to heat a top part of the annular wall; a second annular inductor configured to heat a bottom part of the annular wall. The device makes it possible to increase its energy efficiency and very greatly reduce, even cancel altogether, its carbon dioxide emission level.

The invention relates to a method and facility for manufacturing a fiberglass material, in which melted glass is produced in a melting furnace heated via combustion of a fuel with an oxygen-rich oxidant. The fumes generated are used to preheat a combustion reagent in two steps: a first step in which air is heated via heat exchange with the fumes, and a second step in which the combustion reagent is preheated via heat exchange with the hot air. The air is then used in the method for converting the melted glass into a fiberglass material.

The invention relates to a method and facility for manufacturing a fiberglass material, in which melted glass is produced in a melting furnace heated via combustion of a fuel with an oxygen-rich oxidant. The fumes generated are used to preheat a combustion reagent in two steps: a first step in which air is heated via heat exchange with the fumes, and a second step in which the combustion reagent is preheated via heat exchange with the hot air. The air is then used in the method for converting the melted glass into a fiberglass material.

A glass wool which has physical properties required for a heat insulation material, can be produced industrially, can have reduced hygroscopicity, and has a novel compounding composition. The glass wool having the following glass composition: SiO.sub.2: 60.0 to 65.0% by mass inclusive, Al.sub.2O.sub.3: 0.5 to 2.0% by mass inclusive, Na.sub.2O and K.sub.2O: 13.0 to 17.0% by mass inclusive, MgO and CaO: 8.0 to 12.0% by mass inclusive, B.sub.2O.sub.3: 5.0 to 12.0% by mass inclusive, and others: a remainder.