A method of reducing the formaldehyde emission of a mineral fiber product bonded with a urea-modified phenol-formaldehyde resol resin-type binder comprises adding dextrose to the binder composition during and/or after preparation of the binder composition but before curing of the binder composition applied to the mineral fibers.

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.

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.

The present invention relates to a sizing composition for mineral fibers, especially glass fibers or rock fibers, containing a liquid phenolic resin having a free formaldehyde content, expressed with respect to the total weight of liquid, of 0.1% or less and an extender.

Preferably, the liquid phenolic resin is mainly composed of phenol-formaldehyde and phenol-formaldehyde-amine condensates and has a water dilutability, at 20° C., at least equal to 1000%.

Another subject of the present invention is the insulating products based on mineral fibers treated by said sizing composition.

The present invention relates to a sizing composition for mineral fibers, especially glass fibers or rock fibers, containing a liquid phenolic resin having a free formaldehyde content, expressed with respect to the total weight of liquid, of 0.1% or less and an extender.

Preferably, the liquid phenolic resin is mainly composed of phenol-formaldehyde and phenol-formaldehyde-amine condensates and has a water dilutability, at 20° C., at least equal to 1000%.

Another subject of the present invention is the insulating products based on mineral fibers treated by said sizing composition.

A method of making a glass mat includes providing an assembly of glass fibers, applying a binder composition to the assembly of glass fibers, wherein the binder includes an organic resin, and curing the binder composition while dimensionally constraining the assembly of glass fibers. Dimensional constraining includes directly contacting a first major surface and a second major surface of the assembly of glass fibers between two substantially parallel surfaces. Further provided is a glass mat that includes an assembly of glass fibers, wherein the assembly of glass fibers are substantially randomly oriented with a tensile anisotropy of less than about 6 in any two directions. The glass mat has a decreased surface roughness and a decreased caliper compared to an equivalent glass mat having an assembly of naturally packed glass fibers with an equivalent fiber diameter size.

A method of making a glass mat includes providing an assembly of glass fibers, applying a binder composition to the assembly of glass fibers, wherein the binder includes an organic resin, and curing the binder composition while dimensionally constraining the assembly of glass fibers. Dimensional constraining includes directly contacting a first major surface and a second major surface of the assembly of glass fibers between two substantially parallel surfaces. Further provided is a glass mat that includes an assembly of glass fibers, wherein the assembly of glass fibers are substantially randomly oriented with a tensile anisotropy of less than about 6 in any two directions. The glass mat has a decreased surface roughness and a decreased caliper compared to an equivalent glass mat having an assembly of naturally packed glass fibers with an equivalent fiber diameter size.

The present invention relates to a sizing composition for mineral fibers, especially glass fibers or rock fibers, containing a liquid phenolic resin having a free formaldehyde content, expressed with respect to the total weight of liquid, of 0.1% or less and an extender. Preferably, the liquid phenolic resin is mainly composed of phenol-formaldehyde and phenol-formaldehyde-amine condensates and has a water dilutability, at 20 C., at least equal to 1000%. Another subject of the present invention is the insulating products based on mineral fibers treated by said sizing composition.

The present invention relates to a sizing composition for mineral fibers, especially glass fibers or rock fibers, containing a liquid phenolic resin having a free formaldehyde content, expressed with respect to the total weight of liquid, of 0.1% or less and an extender. Preferably, the liquid phenolic resin is mainly composed of phenol-formaldehyde and phenol-formaldehyde-amine condensates and has a water dilutability, at 20 C., at least equal to 1000%. Another subject of the present invention is the insulating products based on mineral fibers treated by said sizing composition.

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.