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.

The invention relates to a thermal insulation product based on mineral wool comprising mineral fibers, the product comprising two main faces and longitudinal and transverse edges perpendicular to the main faces, the product being characterized by the following orientation fractions: a longitudinal orientation fraction greater than or equal to 48 %, or even 50 %, along an angle of more or less 6° with respect to the plane of the main faces, when the mineral fibers are counted only in a longitudinal cross-section, and a mean orientation fraction greater than or equal to 40 %, or even 45 %, along an angle of more or less 6° with respect to the plane of the main faces, when the mineral fibers are counted both in a transverse cross-section and in a longitudinal cross-section. The invention allows the insulating power of a thermal insulation product based on mineral wool to be improved without increasing its thickness.

An insulation product includes mineral fibers and a binder obtained by curing a binding compound, includes as components a) compounds including at least one epoxy function, including at least one epoxy precursor chosen from aliphatic compounds including at least two epoxy functions, b) a hardener chosen from compounds including at least two reactive functions chosen from hydroxyl and carboxylic acid functions, it being possible for the carboxylic acid function(s) to be in salt or anhydride form.

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 process for manufacturing self-adhesive insulation products based on mineral wool includes (a) forming mineral fibers by centrifugation of molten glass or rock, (b) spraying, over the mineral fibers, immediately after the forming, a first liquid organic binder composition, (c) forming a blanket of mineral fibers which are coated with the first liquid organic binder composition, (d) covering a face of the blanket with a surfacing mat of glass or organic fibers having high heat resistance, (e) heating the blanket, covered with the surfacing mat, in a drying oven for a period of time and at a temperature sufficient to cure the organic binder, and (f) applying, to the exposed face of the surfacing mat, a self-adhesive material. A second liquid organic binder composition is applied, after stage (c), to the mat and/or face of the blanket which is intended to come into contact with the surfacing mat.

A process for manufacturing self-adhesive insulation products based on mineral wool includes (a) forming mineral fibers by centrifugation of molten glass or rock, (b) spraying, over the mineral fibers, immediately after the forming, a first liquid organic binder composition, (c) forming a blanket of mineral fibers which are coated with the first liquid organic binder composition, (d) covering a face of the blanket with a surfacing mat of glass or organic fibers having high heat resistance, (e) heating the blanket, covered with the surfacing mat, in a drying oven for a period of time and at a temperature sufficient to cure the organic binder, and (f) applying, to the exposed face of the surfacing mat, a self-adhesive material. A second liquid organic binder composition is applied, after stage (c), to the mat and/or face of the blanket which is intended to come into contact with the surfacing mat.

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 herewith, wherein the angle is strictly less than 90.

The present invention concerns a method of determination of specific points of a rotary fibre forming spinner wheel (10) used in a fibre forming device (1), said method comprising the following steps: obtaining measurements of temperatures of the fibre forming spinner wheel obtained by means of a temperature measuring device (40) adapted to take measurements of temperatures of the spinner wheel at a plurality of angular positions of said measuring device in order to supply data to at least one calculation unit (30, 45) that constructs a curve representing the temperature as a function of the angular position of a temperature measuring device; processing said measurements by effecting a calculation of the second derivative of the curve of the temperature as a function of the angular position by means of a calculation unit (30); searching for at least one specific point for which the second derivative satisfies a predefined condition.

The present invention concerns a method of determination of specific points of a rotary fibre forming spinner wheel (10) used in a fibre forming device (1), said method comprising the following steps: obtaining measurements of temperatures of the fibre forming spinner wheel obtained by means of a temperature measuring device (40) adapted to take measurements of temperatures of the spinner wheel at a plurality of angular positions of said measuring device in order to supply data to at least one calculation unit (30, 45) that constructs a curve representing the temperature as a function of the angular position of a temperature measuring device; processing said measurements by effecting a calculation of the second derivative of the curve of the temperature as a function of the angular position by means of a calculation unit (30); searching for at least one specific point for which the second derivative satisfies a predefined condition.

A fibre forming device for fabricating mineral fibres, includes a fibre forming spinner wheel pierced to enable centrifugal fabrication of the fibres, the fibre forming device including at least one annular burner producing an annular gas flow to stretch the fibres and an evacuation system for evacuating smoke created by the burner, the device further including a system adapted to vary the temperature of the spinner wheel, the temperature variation system being a device for circulation of air between the annular burner and the evacuation system to control the smoke evacuation flow.