Sound-absorbing acoustic panel

Abstract

An acoustic panel comprising: a layer comprising wood wool and at least one binder; the invention relates to a composite material comprising a substrate, a substrate, and a liner comprising a glass fiber-based nonwoven, characterized in that the glass fiber-based nonwoven has an airflow impedance [sigma] (ISO 9053-1: 2018) of at least 5.00 * 105 Pa.s / m2.

Description

[0001] The present invention relates to a sound absorbing acoustic panel comprising a layer of a wood wool composite system and a nonwoven lining.

[0002] Mineral-bonded wood wool boards (other expressions are WW boards, WW panels, (WW) lightweight panels) are building panels made of wood wool (usually long-fiber wood wool) and a mineral binder (hereinafter also synonymously referred to as "binder"). For the present document, the expressions "board" and "panel" are understood to be synonymous, and the term "panel" will be used consistently.

[0003] The amount of binder is chosen so that the wood wool strands bind together and form a dimensionally stable solid layer, but without creating bulky binder layers. In contrast, the lightweight panel is highly porous.

[0004] For example, the panels can usually also be cut or sawn. For example, WW panels are used as indoor and outdoor insulation panels, they can be plastered, or as acoustically effective ceiling and wall cladding. Building panels based on WW panels often include additional layers, in particular those which take over functional tasks. Multilayer lightweight panels are used in particular for thermal and sound insulation and for optimizing and improving room acoustics.

[0005] Sound insulation refers to blocking sound so that it cannot travel from one room to another, i.e. soundproofing. Sound absorption, on the other hand, refers to stopping sound from bouncing around the room, and accordingly refers to room acoustics (sound damping). Room acoustics can be optimized by room paneling with good sound absorption properties. Room acoustics are optimized when sound is highly absorbed and little reflected.

[0006] The sound absorption value α can be used according to DIN EN ISO 11654 (same as ISO 11654) W The acoustic optimization of a room is evaluated by using the sound absorption coefficient (also called the sound absorption coefficient), which indicates the proportion of the sound absorbed by the insulation material (0 means complete reflection and 1 means complete absorption). The sound absorption coefficient can be divided into the following ranges or levels:

[0007]

[0008] 1) Designated as "Not Classified" in DIN EN ISO 11654

[0009] Panels based on wood wool and inorganic binders are generally highly porous systems. The binder serves to hold the wood wool together mechanically, but does not generally form a closed, impermeable layer. Due to their low density and the cavities retained between the bonded wood wool shavings, these panels have good insulating properties and a certain sound insulation effect, but these generally do not meet high requirements. The achieved sound absorption class is generally D or C. Composite systems made of layers of different materials (one of which can be the described wood wool composite system) and / or different structures are used so that the resulting composite panel has the desired properties. In this way, sound absorption classes B or even A can be achieved.

[0010] Wood shavings are mechanically separated wood particles obtained from wood during the sawing or planing process. The term wood wool shavings refers to elongated, usually fine, thread-like or flaky wood particles which can also be obtained by mechanical separation and are usually free of splinters. Often only the general expression wood wool is used, specifically a pile of wood wool shavings. Like the wood from which they are derived, wood wool and wood shavings are based on wood fibers. Wood fibers are elongated wood cells or wood cell composites which are part of the wood and provide the plant with its strength.

[0011] The individual design of the composite panel also depends on the intended use. For example, the German utility model DE 20 109 704U shows a sound insulation element for a floor in the form of a multilayer panel, wherein the outer layer of the panel consists of a wood wool lightweight material and wherein the wood wool layer has raised sections. The sound insulation element is applied as a dry mortar layer floating on the floor substrate. For sound insulation, the contact area between the element and the floor material should be minimized. Wall and ceiling coverings are not described.

[0012] EP 971 080B describes a sound absorbing composite panel in which a fiber mat, which may be made of mineral fibers, has a wood wool insulation panel bonded to one of its surfaces. A nonwoven, such as a glass nonwoven, is bonded to its other surface. The wood fibers of the wood wool insulation panel may be bonded with a magnesium binder. The composite panel is used as a sound insulation panel between the tracks in a tunnel, for example in a railway tunnel.

[0013] For example, EP 464 618B proposes an insulating layer for wall or ceiling insulation. There, an air-permeable fiber material layer is provided with an air-permeable, bonded wood wool layer on one or both sides, wherein the connection is carried out by partial bonding.

[0014] EP 2 006 462 B discloses an acoustic multilayer panel. A layer comprising wood wool shavings is used as a core layer, the shavings being bonded with an inorganic binder. On one of the surfaces of the wood wool layer, a perforated surface layer is provided in the form of a prefabricated semi-finished product or a cured integral mass. On the other surface of the wood wool layer, a mineral fiber covering layer, a gypsum board or glass wool is applied. The non-perforated side of the multilayer board is used to attach the multilayer board to a ceiling or a wall.

[0015] Due to the high permeability (porosity) of wood wool panels, the thermal insulation properties can be improved, but at the expense of sound absorption. By using rock wool panels as an additional layer, the sound insulation can be significantly improved and an optimized product is obtained in terms of both thermal and sound insulation.

[0016] One such product is available from Knauf Ceiling Solutions under the name Fineplus is available. This is a double-layer panel consisting of a magnesite-bonded wood wool panel and a rock wool board layer with drip protection as an absorber. In order to best optimize the room acoustics, the absorber layer has approximately the same thickness as the wood wool panel, typically in the range of a few centimeters in thickness, for example in the range of 2.5 cm to 5 cm.

[0017] Especially for use in gyms, sports halls and the like, acoustic panels must exhibit high mechanical stability in addition to the properties discussed above. Furthermore, they must be easy to attach and install. In particular, they must be safe against pitched balls (hereinafter also referred to as "ball-proof"). Building panels that remain durable under the mechanical stresses caused by balls without significant changes to the element and its underlying structure (in particular complying with relevant standards such as DIN 18032-3:2018-11) are considered to be ball-proof.

[0018] Wall panels or ceiling panels are usually fixed to (underlying) building elements such as rails, profiles or wooden laths. See above, since the sound-absorbing rock wool panels need to have a certain thickness in order to provide good room acoustics, it is not possible to securely fasten the panels to the building rails through this layer. Therefore, the above-mentioned panels with rock wool panels are not suitable for use, for example, in gyms. Such an application means that the rock wool panels must be recessed at the same distance as the building rails. This will be disadvantageous for the acoustic effect (because a large area of ​​the panel will be without the absorber layer) and will require a lot of work during manufacturing. Therefore, due to the mineral wool applied to the back of the panel, it is not possible to install the panel crosswise to the building elements. Therefore, commercially available products for this application are excluded for design reasons, because the support of 600mm or 625mm as required by the relevant building standards cannot be maintained.

[0019] Last but not least, rockwool fibers are considered to be harmful and carcinogenic when they have a certain size and concentration. Therefore, in the current Technical Rules on Hazardous Substances (TRGS) and similar regulations, it is necessary to reduce certain sizes of man-made mineral fibers (AMF), or even completely ban them.

[0020] Another requirement for acoustic panels refers to their fire rating, which should meet relevant specifications.

[0021] Therefore, there is a need for a sound absorbing acoustic panel which does not have the above mentioned disadvantages or has them only to a lesser extent and / or which meets the above mentioned required features. Such an acoustic panel should be suitable for gyms, sports halls and / or multipurpose halls. Preferably, the positive properties of the acoustic panel according to the prior art, such as fire integrity, should not be significantly deteriorated.

[0022] Surprisingly, it was found that the sound-absorbing acoustic panel according to the main claim and according to the dependent claims (hereinafter referred to as "acoustic panel") has the desired properties to solve the problems. The sound-absorbing acoustic panel according to the invention is a panel for optimizing the acoustics of a room. According to the main claim, the acoustic panel comprises a layer comprising wood wool and at least one binder; and a lining comprising a nonwoven based on glass fibers. Preferably, the lining comprises a nonwoven based on glass fibers and cellulose fibers.

[0023] The layer containing wood wool contains a certain amount of binder to ensure that the layer is dimensionally stable in the hardened and (if applicable) pressed shape and forms a solid panel. Advantageously, the hardened binder system does not build up a massive and closed layer, but is added in a small amount that is only sufficient to bind the wood wool shavings to each other, but allows the layer to remain porous or even highly porous. This ensures that the layer is dimensionally stable (form-stable) as required, but also has the best possible sound absorption properties and a low dead weight.

[0024] The layer of the acoustic panel according to the invention comprising wood wool and at least one binder is hereinafter referred to as "wood wool panel".

[0025] Within the scope of this document, a nonwoven based on glass fibers is referred to as a "glass fiber nonwoven", independently of any other fibers that may be present in the nonwoven. The glass fiber nonwoven acts as a sound absorber. This means that it improves the room acoustic optimization properties of the acoustic panel according to the invention compared to a pure wood wool panel. A glass fiber nonwoven is a nonwoven according to the definition in EN 29092 (DIN EN 29092:1992-08). According to the invention, it contains glass fibers. Preferably, the amount of glass fibers in the glass fiber nonwoven is at least half of the amount of all fibers present, or even more. The glass fiber nonwoven is a porous material.

[0026] In one aspect of the present invention, all fibers present in the glass fiber nonwoven are glass fibers. In the alternative preferred aspect of the present invention, the glass fiber nonwoven also comprises one or more other fibers. However, advantageously, there is no rock wool fiber and other harmful AMF fibers, and therefore is not a component of the glass fiber nonwoven. The glass fiber present in the glass fiber nonwoven is preferably selected so that it is neither classified as harmful nor classified as carcinogenic due to its size. Therefore, the presence of harmful artificial mineral fibers can be avoided.

[0027] The glass fiber nonwoven may be prefabricated and thus represent a separate entity, which is usually the case.However, it is also possible to produce the glass fiber nonwoven during the production of the acoustic panel according to the invention (produced in situ and not representing a separate object previously).

[0028] Even at very low thicknesses, the glass fiber nonwoven used according to the invention has sound absorption properties that correspond to those of the much thicker rock wool panels used previously, for example when the latter have a thickness of 25 mm. Therefore, according to the invention, glass fiber nonwoven fabrics having a thickness of less than 2.0 mm, more preferably less than 1.0 mm, and even more preferably less than 0.3 mm are preferably used for the acoustic panel. This makes it possible to reduce the overall thickness of the acoustic panel by almost half, while maintaining or even improving the room acoustic optimization properties.

[0029] Compared to the thickness of the wood wool panel, the thickness of the glass fiber nonwoven is preferably at most 1 / 10, in a preferred case almost 1 / 100 less (e.g., less than 1 / 83 for a preferred implementation of the invention, where the wood wool layer has a thickness of 25 mm and the glass fiber nonwoven lining has a thickness of less than 0.3 mm). Therefore, the glass fiber nonwoven of the acoustic layer is considered to be a lining of the wood wool panel, rather than a separate layer, as the latter is the case with ordinary rock wool panels.

[0030] The glass fiber nonwoven fabric is firmly and durably bonded to one surface of the wood wool panel by bonding means. The bonding means can be the same as the adhesive already used for the wood wool panel, or the same as it. Alternatively or in addition, an additional adhesive or glue can be used as the bonding means.

[0031] The bonding means preferably fully bonds at least the surface of the glass fiber nonwoven with the wood wool panel by full surface fixing, and in addition, it can optionally penetrate into the glass fiber nonwoven to a certain extent. Insertion can improve anchoring. However, the penetration depth should be kept very low so as not to excessively reduce the absorption capacity of the glass fiber nonwoven fabric. Therefore, the bonding means preferably only penetrates into the boundary area of ​​the nonwoven at its surface. Without losing quality, the possible insertion depth depends on the total thickness of the glass fiber nonwoven and the residual thickness of the part (not penetrated) without the bonding means.

[0032] Preferably, in addition to glass fibers, the glass fiber nonwoven also contains cellulose fibers. Glass fiber-cellulose fiber nonwovens can be limited to glass fibers and cellulose fibers, however, one or more additional (different) fibers may also be present. However, likewise, rock wool fibers and harmful AMF fibers are not present in glass fiber-cellulose fiber nonwovens.

[0033] Within the scope of this context, and in light of what has been described, when referring to glass fiber nonwovens, glass fiber-cellulose fiber nonwovens are included unless otherwise stated separately.

[0034] Airflow resistance, specific airflow resistance and airflow impedance are parameters that influence sound absorption and can be used to characterize sound absorption. If there is a pressure difference Δp [Pa] between the two surfaces of the (porous) absorption layer (in the present case glass wool), air flows at a volumetric airflow rate q v flows through the absorbent layer and moves at a speed u = q relative to the traversing surface A of the absorbent layer v / A flows through the absorption layer.

[0035] The ratio of the pressure difference Δp to the volumetric airflow rate qv is called the airflow resistance R, where R = Δp / q V , and the ratio of the pressure difference Δp to the flow velocity u is called the specific flow resistance R S , where R S =R·A=Δp / u.

[0036] The impedance R S Depends on the thickness of the absorbent layer (resistance increases with increasing thickness). Flow resistance R S divided by the thickness d of the absorbent layer is called the airflow resistance σ and can be used as a normalized parameter for the layer under consideration, σ = R S / d.

[0037] Unit: [p] = Pa; [Δp] = Pa; [q V ]=m 3 / s; [u] = m / s; [A] = m 2; [RS] = Pa·s / m; [r] = Pa·s / m 2 . Derived SI units are also allowed.

[0038] Therefore, the values ​​of specific airflow resistance RS and airflow impedance σ specified herein refer to the measurements as disclosed in ISO 9053-1:2018.

[0039] According to the present invention, the glass fiber nonwoven has a hardness of at least 5.00·10 5 Pa·s / m 2 , preferably at least 1.00·10 6 Pa·s / m 2 , more preferably at least 3.00·10 6 Pa·s / m 2 The airflow impedance σ.

[0040] Advantageously, the specific airflow resistance R according to ISO 9053-1:2018 (Chapter 3.2) S At least 1000 Pa·s / m.

[0041] The acoustic panel according to the invention has excellent room acoustics optimization properties and is classified as sound absorption class A (DIN EN ISO 11654).

[0042] Besides its excellent room acoustics optimizing properties, the acoustic panel according to the invention also has good sound insulating properties.

[0043] The layer comprising wood wool and at least one binder is preferably a bonded wood wool layer, i.e. a wood wool panel. In principle, all prefabricated bonded wood wool panels known from the prior art are suitable for this purpose. Alternatively, wood wool panels can be produced by hardening the corresponding mixture of each material to produce a glass fiber nonwoven directly on a glass fiber nonwoven. As a wood wool panel, such panels based on wood wool shavings are particularly suitable, wherein the shavings are connected via an inorganic binder or will be connected via an inorganic binder to form an open-pore structure. Wood wool lightweight panels are particularly preferably used for this layer.

[0044] Wood wool which is very suitable for wood wool panels is based on conifers and / or softwood, for example on spruce or pine. In principle, however, there are no restrictions in this respect.

[0045] Wood wool panels can be limited to their basic components wood wool and a binder system (one or more binders, respectively). When producing wood wool panels, production aids such as water can be used as solvents or suspending agents for the binder system and / or water of hydration in the binder system. This can at least partially remain in the board as water of crystallization and / or residual moisture.

[0046] It is possible that the wood wool panel comprises further components, such as wood fibers and / or textile fibers or the like.

[0047] Additives may be present in wood wool panels such as flame retardants, fireproofing agents and insecticides.

[0048] As already mentioned, the wood wool is based on a variety of wood shavings. Preferred wood shavings of the wood wool generally have a length of more than 8 cm, a width of 1 mm to 4 mm and a thickness of 0.2 mm to 0.5 mm. Since wood fibers are the basic material of wood, individual wood shavings have a high open porosity. Brittle wood wool shavings present in irregular geometric shapes are irregularly distributed in the wood wool panel in the form of an open three-dimensional framework and are at least partially bonded to each other by a binder system (one, two, three or more binders).

[0049] Inorganic or organic binders can be used as binders for wood wool panels. Inorganic (especially mineral) binders are preferred, such as, for example, caustic calcined magnesite (caustic magnesite), magnesite, magnesium sulfate, magnesium hydroxide, calcium carbonate, cement, gypsum. Combinations of two or more binders can also be used, preferably from the binders listed above. If a binder system comprising more than one binder is used, one of the binders is usually selected in a high amount compared to the other binders, while the other binders can be present in a substantially lower amount as co-binders.

[0050] The wood wool panel as used according to the invention preferably has a thickness in the range of 15 mm to 35 mm, for example 25 mm. In principle, the panel can also consist of two or more thinner panels instead of using a single-layer panel. Preferably, the thickness of the combination of thinner panels then has a thickness in the above range.

[0051] The natural, characteristic texture of wood wool is ideal as a surface for creative color designs, so that the surface of the wood wool panel can be visually designed as desired, such as by painting.

[0052] from Knauf Ceiling Solutions Company under the trade name Fine or Superfine commercially available wood wool panels are very suitable as wood wool panels of the present invention and are advantageously used. They are single-layer, magnesite-bonded wood wool panels in which the wood wool fibers are 2 mm (fine) or 1 mm (superfine) in width. These panels are available in different thicknesses and sizes. The binder system comprises caustic magnesite (as the main component) and a co-binder.

[0053] The wood wool panel and the glass fiber nonwoven covering are firmly connected to each other at the contact area, preferably over the entire surface. For this fixation, a separate intermediate connecting layer (e.g., an adhesive or glue layer) may be present between the wood wool panel and the glass fiber nonwoven lining. Alternatively, the wood wool panel and the glass fiber nonwoven covering are connected to each other without an intermediate layer. For example, the binder system of the wood wool panel can also be used to bond glass fiber nonwovens (e.g., glass fiber-cellulose fiber nonwovens). Possible processes for receiving such a connection and producing an acoustic panel without an intermediate layer are discussed below.

[0054] Preferably, the total thickness of the acoustic panels according to the invention perpendicular to their major surfaces is in the range of 15 mm to 40 mm, more preferably 15 mm to 26 mm, even more preferably 15 mm to 25.3 mm. The panel dimensions preferably correspond to common grid sizes, such as 600·600 mm, 625·625 mm, 1200·600 mm or 1250·625 mm. Other dimensions are also possible.

[0055] The acoustic panel according to the invention complies with the relevant fire regulations, the fire behavior corresponding at least to the classification Euroclass "B-s1, d0" according to EN 13501-1 (DIN EN 13501-1:2019-05). The acoustic panel is flame retardant, exhibits no smoke development and no burning dripping / shedding under the specifications mentioned herein.

[0056] The acoustic panel according to the invention is ballproof (safe against pitching) according to DIN 18032-3:2018-11 Chapter 2.1 (characterized as "ballwurfsicher") and according to EN 13964 Supplement D (DIN EN 13964:2014-08). In particular, the acoustic panel complies with class A1 according to this standard. The panel is therefore very suitable as suspended ceilings and paneling or wall coverings in gymnasiums, fitness rooms and halls for sports and multifunctional use.

[0057] Another advantage of the acoustic panel according to the present invention is also conducive to the above-mentioned use, which is caused by the fact that the glass fiber nonwoven is very thin. Therefore, the attachment to the building frame or building rail or other suspension device is not limited, but can be easily achieved with the thin glass fiber nonwoven lining thus produced. This realizes a durable and safe anchoring. Compared with the thick acoustic panel made of rock wool board according to the prior art, the acoustic panel according to the present invention does not require any undercut of the nonwoven, that is, the nonwoven is not offset or shifted to the edge of the wood wool panel. The threaded engagement of the acoustic panel with the (lower layer) building element or suspension device can be achieved by an acoustic panel containing a nonwoven lining without causing a lack of stability. For safe attachment, other nonwoven grooves are also unnecessary. Therefore, the acoustic panels according to the present invention have an absorption effect on their entire surface, and in addition, there are no longer restrictions on the size and span of the acoustic panels and on their alignment, because the threaded engagement can occur anywhere. In addition, the number of adjacent edges can be reduced. These advantages make the acoustic panel fully suitable for gyms such as those that require good stability and good ball resistance to comply with relevant standards.

[0058] Of course, if desired, the second surface of the wood wool panel may also be provided with a corresponding glass fiber nonwoven as described herein. However, in many cases this is not necessary for most performance requirements and may often even be disadvantageous. However, an acoustic panel having two glass fiber nonwoven linings, one lining on one of its surfaces, also falls within the scope of the present invention.

[0059] Figure 1 A sound-absorbing acoustic panel according to the invention is schematically shown, without intending to be limited by the principles presented in the teaching of the invention. A layer 1 comprising at least wood wool and at least one binder and a lining 2 comprising a nonwoven based on glass fibers, in particular based on glass fibers and cellulose fibers, are connected to one another with a common contact area (3) to build an acoustic panel. In particular, the individual components are those described in more detail in this document.

[0060] Figure 2 and Figure 3 The acoustic panel according to the present invention is schematically shown. Figure 2 ) and the case of using rock wool board ( Figure 3 ) compared to the advantages of each of the two cases, a cross-sectional view is shown. Likewise, the embodiments shown herein are only examples and are not intended to unnecessarily limit the present invention.

[0061] according to Figure 2, using an acoustic panel (A) according to the invention. Two wood wool panels (4), each having a lining (5) comprising a glass fiber nonwoven, preferably a glass fiber-cellulose fiber nonwoven, are abutted (9) in the region of the underlying structural element at the edge (6) of the wood wool panel (4). The panel is screwed (8) to the lower part of the suspension device (7) via the acoustic panel A. The upper part of the suspension device (7) is advantageously shaped to engage with a supporting system, a suitable ceiling eyelet, etc. Alternatively, a direct screwing to an underlying structural element, such as a CD profile, a wooden slat, etc., is also possible.

[0062] As already mentioned, it is also possible to install acoustic panels (A) having large area dimensions, since no abutment edges (6) are required at the suspension points (location of the underlying structural elements). Figure 2 In this case, the adjacent edge line (6) will be omitted.

[0063] Figure 3 It is shown how to attach an acoustic panel (B) according to the prior art. In this context, a wood wool panel (4) is provided with a sound insulating rock wool board (10). At the abutting edge (9) of the wood wool panel (4), an offset (11) of the edge (12) of the rock wool board (10) from the edge (6) of the wood wool panel (4) is necessary to ensure a secure threaded engagement (8) of the acoustic panel to the suspension device / underlying structural element (7) and to ensure a secure mounting of the acoustic panel (B) at the abutting edge region. A threaded engagement through the rock wool board (10) would not be possible and would not achieve sufficient stability.

[0064] One aspect of the invention relates to an advantageous method for producing an acoustic panel. In the method, a glass fiber nonwoven is provided and the material for producing a wood wool nonwoven layer, in particular wood wool shavings and a (mineral) binder system, is applied thereto and formed into a layer. Preferably, the layer has a thickness as disclosed above for a wood wool panel. Subsequently, the binder system is hardened or hardened by activation.

[0065] Wood wool, the binder used (binder system) and common suspending agents, especially water, are mixed in a mixer in advance to prepare the desired basic formulation. In a preferred manner, a binder suspension is first prepared from the binder and suspending agent, and the wood wool is subsequently mixed into the suspension.

[0066] In a particularly preferred manner, a belt former is used. In a belt former, a flat body can be produced by applying the base material to a belt, in particular a moving or removable belt, in particular between two belts (lower belt and upper belt) and optionally two side belts. The flat primary product is formed by pressing and / or passing through a slit, a slit nozzle, etc. In order to receive the flat body, further treatments such as curing, solidification, drying, etc. may be necessary. The belt can be moved continuously or discontinuously through the processing stations.

[0067] In the preferred method, the glass fiber nonwoven fabric is brought directly to the lower steel belt of the belt former during the production process. The wet formulation (comprising wood wool shavings and an inorganic binder suspension, preferably prepared as described above) is dispersed or applied to the glass fiber nonwoven. The system can be surrounded by a second horizontal steel belt and two side belts. Optionally, the wet molding formulation is dried through a coagulation channel. When leaving the double belt system, an endless strand is produced. The strand can be cut or sewn into panels of desired length.

[0068] During the pressing step, the glass fiber nonwoven is fully wetted by the wet formulation and the formulation can slightly penetrate the nonwoven. Once dried and the binder hardens, a permanent bond (fixing) of the glass fiber nonwoven to the wood wool panel is achieved. Only thin areas of the nonwoven should be penetrated.

[0069] The advantage of this process is that the hardened binder system itself serves as the bonding means to secure the glass fiber nonwoven liner to the wood wool panel. Therefore, no additional adhesive is required. Intermediate layers are avoided.

[0070] However, it is also possible to prefabricate wood wool panels or to use commercially available wood wool panels (e.g. product) and by using a suitable adhesive or glue to fix the glass fiber nonwoven.

[0071] A further aspect of the invention relates to the use of a glass fiber nonwoven, in particular a glass fiber-cellulose fiber nonwoven, as a component of a sound-absorbing acoustic panel or for producing a sound-absorbing acoustic panel, in particular in the form of a lining for a wood wool panel, wherein the glass fiber nonwoven has a sound absorption coefficient of at least 5.00·10 % according to ISO 9053-1:2018 (Chapter 3.3). 5 Pa·s / m 2 , preferably at least 1.00·10 6 Pa·s / m 2 , more preferably at least 3.00·10 6 Pa·s / m 2 Preferably, a glass fiber nonwoven according to any one of the above-mentioned advantageous aspects is used.

[0072] A further aspect of the invention relates to the use of a glass fiber nonwoven, in particular a glass fiber-cellulose fiber nonwoven, as a component of a sound-absorbing acoustic panel or for producing a sound-absorbing acoustic panel, in particular in the form of a coating of a wood wool panel, wherein the glass fiber nonwoven has a sound absorption coefficient of at least 1.00·10 % according to ISO 9053-1:2018 (Chapter 3.2). 3 Specific airflow resistance R in Pa·s / m S , and wherein the thickness of the glass fiber nonwoven is not greater than 1.0 mm, preferably not greater than 0.5 mm. Preferably, a glass fiber nonwoven according to any of the above-mentioned advantageous aspects is used.

[0073] Advantageously, the acoustic panel according to the invention is used as an acoustic building board in the field of drywall construction, in particular for optimizing room acoustics and / or for sound insulation. It can be used as a ceiling or wall panel, for example for suspended ceilings or wall coverings.

[0074] With the acoustic panel according to the invention the performance of the panel for room acoustic optimization is significantly improved compared to pure wood wool panels without significantly increasing the thickness of the panel.

[0075] The panel performance of the panel for room acoustic optimization may be at least maintained or even improved, while significantly reducing the overall panel thickness, compared to commercially available acoustic panels including wood wool panels and rock wool boards.

[0076] At the same time, an advantageous production method is provided and several further applications have become available, such as use in sports stadiums.

Claims

1. Acoustic panels, including A layer comprising wood wool and at least one binder, and a lining comprising a nonwoven based on glass fibers, Features The glass fiber-based nonwoven has a thickness of at least 5.00·10 5 Pa·s / m 2 The airflow impedance σ (ISO 9053-1:2018).

2. The acoustic panel according to claim 1, characterized in that The glass fiber-based nonwoven has a 6 Pa·s / m 2 , preferably at least 3.00·10 6 Pa·s / m 2 Airflow impedance σ (ISO 9053-1:2018), and / or The glass fiber-based nonwoven has a specific airflow resistance R of at least 1000 Pa·s / m. S (ISO 9053-1:2018).

3. An acoustic panel according to any one of the preceding claims, characterised in that The glass fiber based nonwoven has a thickness perpendicular to the main surface of the acoustic panel of no more than 1.0 mm, preferably no more than 0.3 mm.

4. An acoustic panel according to any one of the preceding claims, characterised in that The total thickness of the acoustic panel perpendicular to the major surface of the acoustic panel is 10 mm to 40 mm, preferably 15 mm to 5.3 mm, and / or The layer comprising wood wool and at least one binder has a thickness perpendicular to the major surface of the acoustic panel of 15 mm to 35 mm.

5. An acoustic panel according to any one of the preceding claims, characterised in that The thickness of the glass fiber-based nonwoven is at most 1 / 10, preferably at most 1 / 80, of the thickness of the layer comprising wood fibers and at least one binder.

6. An acoustic panel according to any one of the preceding claims, characterised in that The glass fiber-based nonwoven also contains cellulose fibers.

7. An acoustic panel according to any one of the preceding claims, characterised in that The liner comprising a glass fiber-based nonwoven consists precisely of said nonwoven.

8. An acoustic panel according to any one of the preceding claims, characterised in that Said lining comprising a nonwoven based on glass fibres is fixed to said layer comprising wood wool and at least one binder by bonding means, in particular wherein said bonding means is the same as said at least one binder of said layer comprising wood wool and at least one binder.

9. An acoustic panel according to any one of the preceding claims, characterised in that The at least one binder is an inorganic binder, in particular a mineral binder, preferably wherein the mineral binder is cement or magnesite, in particular caustic-calcined magnesite.

10. An acoustic panel according to any one of the preceding claims, characterised in that The layer comprising wood wool and at least one acoustic binder also comprises one or more co-binders.

11. An acoustic panel according to any one of the preceding claims, characterised in that The wood wool consists of or comprises wood wool shavings having a length greater than 8 cm, a width of 1 mm to 4 mm, and a thickness of 0.2 mm to 0.5 mm.

12. Method for producing an acoustic panel according to any one of the preceding claims, characterised in that The glass fiber-based nonwoven is brought onto the steel belt of the belt former, applying a moist formulation comprising a suspension of wood wool chips and one or more binders in a suspending agent, in particular in water, to the nonwoven, The moist formulation wets and optionally penetrates into the glass fiber-based nonwoven by a pressing step, The formulation is then hardened by a reaction and / or drying process of the binder.

13. Use of a glass fiber based nonwoven as a component of an acoustic panel according to any one of claims 1 to 11, preferably realized as a lining of a panel based on wood wool and a binder.

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