Glass wool acoustic panel and process for manufacturing said panel

Abstract

The invention relates to a glass wool panel designed for use as an acoustic panel, having: - a density less than or equal to 130 kg / m³, - a density less than or equal to 130 kg / m³, and - a Young's modulus between 0.5 and 4 MPa. The invention provides a lightweight panel with good sound absorption and insulation properties, as well as a method for its production.

Description

[0001] The invention relates to a glass wool panel intended for use as an acoustic panel, for example in a suspended ceiling system.

[0002] Acoustic ceiling panels that combine sound absorption and insulation performance are known on the market. However, these panels, for example made of rock wool or combining mineral wool with a plasterboard backing, are generally very heavy. They are therefore difficult for installers to handle. Furthermore, their weight places stress on the ceiling structures supporting the acoustic panels. A prior art acoustic panel is known as JP H09 170276 A.

[0003] Therefore, there is a need for "lightweight" panels that combine a high level of performance in both sound absorption and sound insulation.

[0004] For this purpose, the invention proposes a glass wool panel intended to be used as an acoustic panel as defined in claim 1.

[0005] According to another characteristic, the panel also has a micron content between 2.5 / 5g and 6 / 5g, preferably between 3 / 5g and 6 / 5g, or even between 3.5 / 5g and 6 / 5g, or even between 4 / 5g and 5 / 5g.

[0006] According to another characteristic, the panel also has a thickness greater than or equal to 25 mm, or greater than or equal to 30 mm, preferably greater than or equal to 35 mm, or greater than or equal to 40 mm, or even greater than or equal to 45 mm.

[0007] According to another distinctive feature, the panel also includes, on each of its main faces, a veil.

[0008] According to another feature, the veil intended to be turned towards the side from which the sound to be dampened originates having a specific resistance to airflow less than or equal to 1 kPa.s / m, preferably less than or equal to 0.5 kPa.s / m, and the opposite veil having a specific resistance to airflow greater than or equal to 1 kPa.s / m, preferably greater than or equal to 5 kPa.s / m, or even greater than or equal to 10 kPa.s / m, or even airtight.

[0009] According to another characteristic, the panel includes a binder mass ratio of between 5% and 15% of the total mass, preferably between 6% and 10% of the total mass.

[0010] According to another characteristic, the panel has a sound absorption α W greater than or equal to 0.9.

[0011] According to another characteristic, the panel has a sound insulation D nfw greater than or equal to 38 dB, preferably greater than or equal to 39 dB, or even greater than or equal to 40 dB, or even greater than or equal to 41 dB, or even greater than or equal to 42 dB.

[0012] The invention also relates to a method for manufacturing the glass wool panel as described above, comprising the following steps: manufacturing a fiberglass mat by internal centrifugation, using an installation comprising: ∘at least one centrifuge capable of rotating around an X axis, in particular vertical, and whose peripheral band is perforated with a plurality of orifices to deliver filaments of a molten material, ∘ a high-temperature gas drawing means in the form of an annular burner which ensures the drawing of the filaments into fibers, and ∘ a receiving mat associated with suction means to receive the fibers, creping of the fiberglass mat with a creping ratio between 1.5 and 5, preferably between 2 and 5, or even between 2.5 and 5, or between 3 and 5.

[0013] Another distinctive feature is that during the fiberglass mat manufacturing stage, a combination of parameters is set from among at least: • the viscosity of the molten glass, which is between 820 and 1500 poise, preferably between 950 and 1200 poise, • the burner pressure, which is between 200 and 1000 mm CE, preferably between 200 and 600 mm CE, • the total glass output per day per centrifuge, which is between 14 tonnes / day and 23 tonnes / day, preferably between 17 and 22 tonnes / day, • the number of holes in each centrifuge, which is between 5000 and 40000, preferably between 15000 and 35000, and • the rotation speed of the centrifuge at a speed greater than 2000 rpm.

[0014] Another distinctive feature is that the diameter of the orifices of each centrifuge is between 0.5 and 1.1 mm.

[0015] According to another characteristic, each centrifuge has a diameter between 200 and 800 mm.

[0016] According to another feature, binder is sprayed onto the glass fibers before they fall onto the receiving mat, with a rate of between 5% and 15% of the total mass, preferably between 6% and 10% of the total mass, the glass fiber mat being put in an oven, preferably after creping, in order to polymerize the binder.

[0017] Another distinctive feature is that a veil is glued to each of the main faces of the glass wool panel.

[0018] The panel according to the invention, with a maximum density of 130 kg / m³, is described as "lightweight." Its acoustic properties (airflow resistance and Young's modulus) make it an ideal candidate for use as an acoustic panel. The lighter the panel, the easier it is to handle and the less stress it places on the supporting structure.

[0019] In parallel, the panel has very interesting acoustic properties thanks to a low airflow resistivity (between 30 and 120 kPa.s / m 2<, preferably between 50 and 110 kPa.s / m 2<, or even between 50 and 100 kPa.s / m 2<, or between 50 and 90 kPa.s / m 2<, or even between 50 and 80 kPa.s / m 2<) and a high Young's modulus (between 0.5 and 4 MPa, preferably between 0.8 and 4 MPa, even more preferably between 1.2 MPa and 4 MPa, or even between 1.5 MPa and 4 MPa, or even between 2 MPa and 4 MPa). Indeed, in the ranges mentioned above, the lower the airflow resistance, the better the sound absorption and, the higher the Young's modulus, the better the sound insulation.

[0020] The measurement of airflow resistivity is carried out according to ISO 9053.

[0021] The measurement of Young's modulus is carried out according to the ISO 18437 standard and according to the article by C. Langlois, R. Panneton and N. Atalla: Polynomial relations for quasi-static mechanical characterization of isotropic poroelastic materials, J. Acoust. Soc. Am., 110:3032-3040, 2001.

[0022] Airflow resistivity and Young's modulus measurements are performed on the panel without the front / rear sails.

[0023] This glass wool panel is produced by internal centrifugal spinning followed by creping of the glass fibers at a creping ratio between 1.5 and 5. The creping ratio influences the airflow resistance and the Young's modulus. The creping ratio is preferably between 2 and 5, or even between 2.5 and 5, or between 3 and 5 to further reduce the airflow resistance and increase the Young's modulus. Indeed, creping promotes the orientation of the fibers along a direction perpendicular to the main faces of the panel: the higher the creping ratio, the greater the fiber orientation along the Z axis, and the more the airflow resistance is reduced and the Young's modulus is increased.

[0024] The glass wool panel also has a micron count between 2.5 / 5g and 6 / 5g. Preferably, the micron count is between 3 / 5g and 6 / 5g, or even between 3.5 / 5g and 6 / 5g, or between 4 / 5g and 5 / 5g. Indeed, the higher the micron count, the lower the airflow resistance.

[0025] The micronaire is representative of fiber fineness. Micronaire measurement reflects the specific surface area by measuring the aerodynamic pressure drop when a given quantity of fibers extracted from an uncoated mattress is subjected to a specific gas pressure—usually air or nitrogen. This measurement is common in mineral fiber production facilities and is performed according to DIN 53941 or ASTM D 1448 standards using a device known as a "micronaire apparatus."

[0026] The glass wool panel also has a thickness of 25 mm or more, or even 30 mm or more, preferably 35 mm or more, or even 40 mm or more, or even 45 mm or more. Indeed, as the panel's density decreases, it becomes more advantageous to have a thicker panel to maintain a satisfactory surface density. The surface density, or basis weight, is preferably between 4 and 6.5 kg / m².

[0027] Optionally, the glass wool panel can be cut along its thickness on a plane substantially parallel to its main faces. In this configuration, the thickness of the glass wool panel before cutting is therefore greater than or equal to 60 mm, preferably greater than or equal to 70 mm, or even greater than or equal to 80 mm.

[0028] However, preferably, the glass wool panel is not cut through its thickness along a plane substantially parallel to its main faces.

[0029] The glass wool panel also features a facing on each of its main faces. The facing intended to be oriented towards the direction from which the sound to be dampened originates, called the front facing, has a specific airflow resistance of 1 kPa·s / m or less, preferably 0.5 kPa·s / m or less, so as to allow maximum sound transmission to the glass wool, which will dampen the sound for good acoustic absorption. The opposite facing, called the back facing, has a specific airflow resistance of 1 kPa·s / m or more, preferably 5 kPa·s / m or more, or even 10 kPa·s / m or more: it is preferably airtight to provide good acoustic insulation. An airtight facing has an infinite specific airflow resistance, that is, one within the limits of what can be measured. The front facing can be painted to improve the aesthetics of the panel on the visible side.The front panel can be glued onto the front face of the panel after light sanding to flatten it.

[0030] The glass wool panel also includes a mass percentage of binder between 5% and 15% of the total mass, preferably between 6% and 10% of the total mass.

[0031] The glass wool panel has a sound absorption αW greater than or equal to 0.9. Sound absorption is measured according to ISO 354. The αW indicator is then calculated according to ISO 11654. Throughout the application, measurements were carried out with a plenum of 200 mm in construction height.

[0032] The glass wool panel exhibits a sound insulation value (D nfw) greater than or equal to 38 dB, preferably greater than or equal to 39 dB, or even greater than or equal to 40 dB, or greater than or equal to 41 dB, or even greater than or equal to 42 dB. The sound insulation is measured according to ISO 10848-1. The D nfw value is then calculated according to ISO 717-1. Throughout the application, measurements were taken with a plenum of 700 mm in construction height.

[0033] Acoustic absorption and insulation measurements are carried out on the panel with the front / rear panels.

[0034] The invention also relates to the manufacturing process for the glass wool panel as described above. The process includes a step of manufacturing a glass fiber mat by internal centrifugation followed by a creping step of the glass fiber mat with a creping ratio between 1.5 and 5.

[0035] The fiberglass mat manufacturing stage using internal centrifugation is carried out using an installation comprising: ∘ at least one centrifuge capable of rotating around an X axis, in particular vertical, and whose peripheral belt is pierced with a plurality of orifices to deliver filaments of a molten material, ∘ a high-temperature gas drawing means in the form of an annular burner which ensures the drawing of the filaments into fibers, and ∘ a receiving mat associated with suction means to receive the fibers.

[0036] The centrifuge(s), also called fiber-forming plates, are used to create mineral fibers or other thermoplastic materials through an internal centrifugation process combined with drawing using a high-temperature gas stream. Internal centrifugation is particularly useful in the industrial production of glass wool, intended for use in thermal and / or acoustic insulation products, for example. A stream of molten glass is introduced into each centrifuge, which rotates at high speed and is perforated around its periphery by a large number of orifices. Through these orifices, the glass is projected as filaments by centrifugal force. These filaments are then subjected to an annular drawing current at high temperature and speed, flowing along the centrifuge wall. This current thins the filaments and transforms them into fibers.The fibers formed are carried by this gaseous drawing current towards a receiving device generally consisting of a gas-permeable belt, called a receiving mat.

[0037] During the fiberglass mat manufacturing stage, a combination of parameters is set from among at least: • the viscosity of the molten glass, which is between 820 and 1500 poise, preferably between 950 and 1200 poise, • the burner pressure, which is between 200 and 1000 mm CE, preferably between 200 and 600 mm CE, • the total glass output per day per centrifuge, which is between 14 tonnes / day and 23 tonnes / day, preferably between 17 and 22 tonnes / day, • the number of holes in each centrifuge, which is between 5000 and 40000, preferably between 15000 and 35000, and • the rotation speed of the centrifuge at a speed greater than 2000 rpm.

[0038] These parameters allow, in particular, the adjustment of the density and micron count of the glass wool panel.

[0039] Preferably, the diameter of the orifices of each centrifuge is between 0.5 and 1.1 mm. Each centrifuge preferably has a diameter between 200 and 800 mm.

[0040] In addition, a binder is sprayed onto the glass fibers before they fall onto the receiving conveyor, at a rate of between 5% and 15% of the total mass, preferably between 6% and 10% of the total mass. The glass fiber mat is then placed in an oven, after creping, to polymerize the binder.

[0041] To finalize the product, a veil is glued onto each of the main faces of the glass wool panel, the specifics of each of the veils having been given above.

[0042] A first example according to the invention is a glass wool panel with a density of 117 kg / m³ and a thickness of 50 mm, exhibiting an airflow resistance of 63 kPa·s / m² and a Young's modulus of 2.3 MPa. The micronaire is 4.3 / 5 g. The crepe ratio is 3.5. The panel comprises a front layer with a specific airflow resistance of 0.3 kPa·s / m and a sealed back layer. The sound absorption coefficient αW is 0.9 and the sound insulation coefficient Dnfw is 42 dB.

[0043] A second example according to the invention is a glass wool panel with a density of 102 kg / m³ and a thickness of 52 mm, exhibiting an airflow resistance of 68 kPa·s / m² and a Young's modulus of 0.9 MPa. The micronaire is 3.6 / 5g. The crepe ratio is 3.5. The panel comprises a front layer with a specific airflow resistance of 0.3 kPa·s / m and a sealed back layer. The sound absorption coefficient αW is 0.95 and the sound insulation coefficient Dnfw is 41 dB.

[0044] Thus, glass wool panels with both good sound absorption and good sound insulation could be manufactured.

Claims

1. A glass wool panel intended to be used as acoustic panel and having: - a density comprised between 100 kg / m3 and 130 kg / m3, preferably comprised between 100 kg / m3 and 120 kg / m3, or comprised between 100 kg / m3 and 110 kg / m3, - an air flow resistivity of between 30 and 120 kPa.s / m2, preferably of between 50 and 110 kPa.s / m2, or of between 50 and 100 kPa.s / m2, or else of between 50 and 90 kPa.s / m2, or of between 50 and 80 kPa.s / m2, and - a Young's modulus of between 0.5 and 4 MPa, preferably of between 0.8 and 4 MPa, more preferably still of between 1.2 MPa and 4 MPa, or of between 1.5 MPa and 4 MPa, or else of between 2 MPa and 4 MPa.

2. The panel as claimed in claim 1, additionally having a micronaire of between 2.5 / 5g and 6 / 5g, preferably between 3 / 5g and 6 / 5g, or between 3.5 / 5g and 6 / 5g, or else between 4 / 5g and 5 / 5g.

3. The panel as claimed in claim 1 or 2, additionally having a thickness of greater than or equal to 25 mm, or greater than or equal to 30 mm, preferably greater than or equal to 35 mm, or greater than or equal to 40 mm, or else greater than or equal to 45 mm.

4. The panel as claimed in one of claims 1 to 3, additionally comprising a veil on each of its main faces.

5. The panel as claimed in one of claims 1 to 4, wherein the veil intended to be facing the side from where the sound to be absorbed originates having a specific air flow resistance of less than or equal to 1 kPa.s / m, preferably less than or equal to 0.5 kPa.s / m, and the opposite veil having a specific air flow resistance of greater than or equal to 1 kPa.s / m, preferably greater than or equal to 5 kPa.s / m, or greater than or equal to 10 kPa.s / m, or else airtight.

6. The panel as claimed in one of claims 1 to 5, comprising a weight content of binder of between 5% and 15% of the total weight, preferably of between 6% and 10% of the total weight.

7. The panel as claimed in one of claims 1 to 6, having a sound absorption αW of greater than or equal to 0.9.

8. The panel as claimed in one of claims 1 to 7, having a sound insulation Dnfw of greater than or equal to 38 dB, preferably greater than or equal to 39 dB, or greater than or equal to 40 dB, or else greater than or equal to 41 dB, or greater than or equal to 42 dB.

9. A process for manufacturing the glass wool panel as claimed in one of claims 1 to 8, comprising the following steps: - manufacturing a mat of glass fibers by internal centrifugation, using equipment comprising: ∘ at least one centrifuge capable of rotating about an axis X, in particular a vertical axis, and the peripheral band of which is pierced by a plurality of orifices for delivering filaments of a molten material, ∘ a high-temperature gas attenuating means in the form of an annular burner that attenuates the filaments into fibers, and ∘ a receiving belt associated with suction means for receiving the fibers, - crimping the mat of glass fibers with a degree of crimping of between 1.5 and 5, preferably of between 2 and 5, or of between 2.5 and 5, or else of between 3 and 5.

10. The process as claimed in claim 9, wherein, during the step of manufacturing the mat of glass fibers, a combination of parameters is regulated from among at least: ∘ the viscosity of the molten glass, which is between 820 and 1500 poise, preferably between 950 and 1200 poise, ∘ the pressure of the burner, between 200 and 1000 mm WC, preferably between 200 and 600 mm WC, ∘ the total daily output of glass per centrifuge, which is between 14 metric tons / day and 23 metric tons / day, preferably between 17 and 22 metric tons / day, ∘ the number of holes of each centrifuge, which is between 5000 and 40 000, preferably between 15 000 and 35 000, and ∘ the rotational speed of the centrifuge at a speed greater than 2000 revolutions / minute.

11. The process as claimed in claim 9 or 10, wherein the diameter of the orifices of each centrifuge is between 0.5 and 1.1 mm.

12. The process as claimed in one of claims 9 to 11, wherein each centrifuge has a diameter of between 200 and 800 mm.

13. The process as claimed in one of claims 9 to 12, wherein binder is projected onto the glass fibers before they fall onto the receiving belt, with a content of between 5% and 15% of the total weight, preferably of between 6% and 10% of the total weight, the mat of glass fibers being passed into a drying oven, preferably after crimping, in order to polymerize the binder.

14. The process as claimed in one of claims 9 to 13, wherein a veil is adhesively bonded to each of the main faces of the glass wool panel.