Provided is a glass fiber having a low spinning temperature and a low liquidus temperature, and besides, having a large difference between the liquidus temperature and the spinning temperature, and a method of manufacturing the same. The glass fiber of the present invention includes as a glass composition, in terms of mass % on an oxide basis, 50% to 65% of SiO.sub.2, 0% to 3% of Al.sub.2O.sub.3, 0% to 1% of MgO, 0% to less than 0.7% of CaO, 0% to 1% of Li.sub.2O, 10% to 20% of Na.sub.2O, 0% to 2% of K.sub.2O, 6% to 10% of TiO.sub.2, and 15% to 20% of ZrO.sub.2, and has a value for (Na.sub.2O+K.sub.2O)/(MgO+CaO) of 6.0 or more.

A thermal insulation material includes inorganic fibers and an endothermic material dispersed throughout the inorganic fibers. The endothermic material may be incorporated into the inorganic fibers during a fiber attenuation process. The endothermic material may be particles entangled within a web of the inorganic fibers or may be coated onto surfaces of the inorganic fibers.

A glass wool panel, intended to be used as an acoustic panel, has a density of less than or equal to 130 kg/m.sup.3, an air flow resistivity of between 30 and 120 kPa.Math.s/m.sup.2, a Young's modulus of between 0.5 and 4 MPa.

A glass wool panel, intended to be used as an acoustic panel, has a density of less than or equal to 130 kg/m.sup.3, an air flow resistivity of between 30 and 120 kPa.Math.s/m.sup.2, a Young's modulus of between 0.5 and 4 MPa.

A spinner for fiberizing mineral fibers, in particular glass fibers, by centrifugation from a molten material, includes a peripheral barrel pierced with orifices for the passage of the molten material and for obtaining fibers by drawing during the centrifugation, a wheel center connecting the peripheral barrel to an upper flange for securing the spinner in a fiberizing device, a turnup extending the peripheral barrel in the bottom part of the spinner and making an angle β herewith, wherein the angle β is strictly less than 90°.

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 present invention relates to a method for producing mineral wool having a chemical composition, expressed as a percentage by weight of oxides, comprising:

TABLE-US-00001 SiO2 30-50%  Al2O3 15-35%  CaO 5-25% MgO 1-25% Fe2O3 2-15% Na2O + K2O  >10%
said method comprising providing a mixture of raw materials, melting said mixture of raw materials to obtain a molten material, and fiberizing the molten material; characterized in that the mixture of raw materials comprises at least 8.5% by weight of a recycled raw material comprising at least 3% of magnesium, expressed by weight of oxides, said recycled raw material being substantially free of carbonates, and in that the mixture of raw materials is free of dolomite and magnesia.

The present invention relates to a method for producing mineral wool having a chemical composition, expressed as a percentage by weight of oxides, comprising:

TABLE-US-00001 SiO2 30-50%  Al2O3 15-35%  CaO 5-25% MgO 1-25% Fe2O3 2-15% Na2O + K2O  >10%
said method comprising providing a mixture of raw materials, melting said mixture of raw materials to obtain a molten material, and fiberizing the molten material; characterized in that the mixture of raw materials comprises at least 8.5% by weight of a recycled raw material comprising at least 3% of magnesium, expressed by weight of oxides, said recycled raw material being substantially free of carbonates, and in that the mixture of raw materials is free of dolomite and magnesia.

The invention relates to an apparatus for manufacturing mineral wool. The apparatus includes means (1) for producing molten mineral material, at least one fiberizing device (3) for forming fibres, into which fiberizing device the molten mineral material is fed (2) and by which fibres (12) are formed. The fiberizing device (3) comprises, rotationally arranged around a vertical axis (15), at least one fiberizing plate (13) having a vertical peripheral edge, into which are formed numerous small-sized holes (14), through which the molten material is led by centrifugal force to form fibres (12). Into the fiberizing device (3) are arranged elements to produce a vertical flow of blowing medium (16) to be led around the fiberizing plate (13), the flow causing the fibres (12) to turn downwards and, at the same time, to thin. Downstream the fiberizing device (3) is arranged a collection device (6), into which the formed fibres (12) are led and collected into a mat-like material. In connection with said at least one fiberizing plate (13) is arranged a substantially horizontal, relatively narrow channel (5), through which the fibres (12) are brought into the chamber space (7) of the collection device (6). The invention further relates to a method for manufacturing mineral wool and a mineral wool product manufactured by the method.

The invention relates to an apparatus for manufacturing mineral wool. The apparatus includes means (1) for producing molten mineral material, at least one fiberizing device (3) for forming fibres, into which fiberizing device the molten mineral material is fed (2) and by which fibres (12) are formed. The fiberizing device (3) comprises, rotationally arranged around a vertical axis (15), at least one fiberizing plate (13) having a vertical peripheral edge, into which are formed numerous small-sized holes (14), through which the molten material is led by centrifugal force to form fibres (12). Into the fiberizing device (3) are arranged elements to produce a vertical flow of blowing medium (16) to be led around the fiberizing plate (13), the flow causing the fibres (12) to turn downwards and, at the same time, to thin. Downstream the fiberizing device (3) is arranged a collection device (6), into which the formed fibres (12) are led and collected into a mat-like material. In connection with said at least one fiberizing plate (13) is arranged a substantially horizontal, relatively narrow channel (5), through which the fibres (12) are brought into the chamber space (7) of the collection device (6). The invention further relates to a method for manufacturing mineral wool and a mineral wool product manufactured by the method.