Thermal insulation product based on mineral wool and method of fabrication of the product
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.
1. A method of fabricating a thermal insulation product based on mineral wool, the method comprising:
fabricating mineral fibers from molten glass in a centrifuge,
receiving the mineral fibers on a reception belt having a speed V 0 ,
conveying the mineral fibers on a first group of conveyers, a speed V 1 of a last conveyer of the first group of conveyers being in the range between greater than 100% and 105% of V 0 , and
conveying the mineral fibers on a second group of conveyers, a speed V 2 of a last conveyer of the second group of conveyers being in the range between 108% and 120% of V 0 ,
wherein the thermal insulation product based on mineral wool produced by the method comprises 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 TO L (0°+/−6°) greater than or equal to 48% 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 TO m (0°+/−6°) greater than or equal to 40% 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.
2. The method of claim 1 , wherein the conveyers of the second group all have a speed greater than that of the conveyers of the first group.
3. The method of claim 1 , wherein a number of conveyers of the first group is in the range between 3 and 10.
4. The method of claim 1 , wherein a number of conveyers of the second group is in the range between 2 and 5.
5. The method of claim 1 , wherein the speed of each conveyer of the first group increases by the same amount as for a preceding conveyer.
6. The method of claim 1 , wherein the speed of each conveyer of the second group increases by the same amount as for a preceding conveyer or the speed of each conveyer of the second group increases faster than that of the preceding conveyer.
7. The method of claim 1 , wherein, for the two last conveyers at least, the mineral fibers are progressively compressed when going between at least the last two conveyers and at least two upper driving devices.
8. The method of claim 1 , wherein the thermal insulation product based on mineral wool produced by the method has a thermal conductivity less than or equal to 32 mW/m·K and a density of 15 kg/m 3 -60 kg/m 3 .
9. The method of claim 1 , wherein the thermal insulation product based on mineral wool produced by the method has a thermal conductivity less than or equal to 29 mW/m·K and a density of 55-80 kg/m 3 .