One subject of the invention is a process for manufacturing a glass, the chemical composition of which comprises at least 3% by weight of iron oxide, expressed in the form Fe.sub.2O.sub.3, comprising a step of electric melting, using electrodes submerged in the molten glass, of a vitrifiable batch material mixture containing at least one manganese carrier wherein the manganese is in an oxidation state higher than +2.

A drying oven for crosslinking a continuous mat of mineral or plant fibers includes a plurality of heating boxes through which the mat of fibers successively passes. At least one of the boxes includes, between an external insulating jacket of the drying oven and a central compartment of the box, an in-built hot-gas heating and recirculation device that includes at least one radial turbine mounted horizontally, the axis of rotation of which is arranged vertically, the turbine drawing hot gas along the axis through a gas outlet orifice of the central compartment after it has passed through the mat, and discharging it radially toward a recirculation device that recirculates the hot gas leaving the radial turbine to a gas inlet orifice of the compartment, and at least one heating device for heating the gas circulating in the box.

A drying oven for crosslinking a continuous mat of mineral or plant fibers includes a plurality of heating boxes through which the mat of fibers successively passes. At least one of the boxes includes, between an external insulating jacket of the drying oven and a central compartment of the box, an in-built hot-gas heating and recirculation device that includes at least one radial turbine mounted horizontally, the axis of rotation of which is arranged vertically, the turbine drawing hot gas along the axis through a gas outlet orifice of the central compartment after it has passed through the mat, and discharging it radially toward a recirculation device that recirculates the hot gas leaving the radial turbine to a gas inlet orifice of the compartment, and at least one heating device for heating the gas circulating in the box.

Described herein are apparatuses and methods of creating fibers, such as microfibers and nanofibers. The methods discussed herein employ centrifugal forces to transform material into fibers. Apparatuses that may be used to create fibers are also described. Systems and methods of heating the fiber producing device, before and during use, are also described herein.

Provided is a cooling water spray apparatus including a plurality of spinners disposed to be adjacent to one another along a travel path of a target to be cooled, and a plurality of cooling water spray holes provided on each spinner and configured to spray cooling water. The plurality of spinners may be non-overlappingly disposed with respect to one another.

A fibrous insulation product with improved thermal resistance and method of making it are provided. A plurality of base fibers (e.g. glass) are formed into an insulation product, which may be bindered or unbonded. At least one infrared opacifying agent, such as soot, carbon black or graphite, is applied to the fibrous insulation product such that the base fibers are substantially uniformly coated with opacifying agent. The opacifying agent may be applied, for example, from a fluid suspension or by pulling the fiber through a sooty flame. When opacifying agent applied via a suspension and a binder is desired, it is preferable to avoid binder dispersions that can dislocate the opacifying agent. Alternative binder applications may include co-mingling of base fibers with binder fibers, or other physical or mechanical distributions.

A fibrous insulation product with improved thermal resistance and method of making it are provided. A plurality of base fibers (e.g. glass) are formed into an insulation product, which may be bindered or unbonded. At least one infrared opacifying agent, such as soot, carbon black or graphite, is applied to the fibrous insulation product such that the base fibers are substantially uniformly coated with opacifying agent. The opacifying agent may be applied, for example, from a fluid suspension or by pulling the fiber through a sooty flame. When opacifying agent applied via a suspension and a binder is desired, it is preferable to avoid binder dispersions that can dislocate the opacifying agent. Alternative binder applications may include co-mingling of base fibers with binder fibers, or other physical or mechanical distributions.

A thermal insulation product based on mineral wool, characterized in that the fibers have a micronaire of less than 10 l/min, preferably less than 7 l/min and especially between 3 and 6 l/min, and in that the material has a thermal conductivity of less than 31 mW/m.Math.K, especially less than 30 mW/m.Math.K. The parameters for obtaining this product are in particular the pressure of the burner, the rotation speed of the fiberizing spinner and the daily fiber output per spinner orifice.

A thermal insulation product based on mineral wool, characterized in that the fibers have a micronaire of less than 10 l/min, preferably less than 7 l/min and especially between 3 and 6 l/min, and in that the material has a thermal conductivity of less than 31 mW/m.Math.K, especially less than 30 mW/m.Math.K. The parameters for obtaining this product are in particular the pressure of the burner, the rotation speed of the fiberizing spinner and the daily fiber output per spinner orifice.

Described herein are apparatuses and methods of creating fibers, such as microfibers and nanofibers, that include additives that modify one or more properties of the produced fibers. The methods discussed herein employ centrifugal forces to transform material into fibers. Apparatuses that may be used to create fibers are also described. Fiber producing devices with features that enhance fiber production and adaptability to different types of fiber are described.