EP3935624A1

EP3935624A1 - Sound absorber, structure and use of a sound absorber

Info

Publication number: EP3935624A1
Application number: EP20709569.6A
Authority: EP
Inventors: Moritz SPÄH; Xiaoru Zhou; Wolfgang Herget; Peter BRANDSTÄTT; Michael Krämer
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date: 2019-03-07
Filing date: 2020-03-06
Publication date: 2022-01-12
Anticipated expiration: 2040-03-06
Also published as: EP3935624C0; WO2020178427A1; EP3935624B1

Abstract

The invention relates to a use of a sound absorber with an open-pored base plate (1), which has a flow resistance of approximately 500 Ns/m³ to approximately 6000 Ns/m³ according to DIN EN 29053:1993-05, with at least a partial surface of the base plate (1) being provided with a microperforated material layer (2), in or on a building. The invention further relates to a sound absorber with at least one open-pored base plate (1), which has a flow resistance of approximately 500 Ns/m³ to approximately 6000 Ns/m³ according to DIN EN 29053:1993-05, with at least a partial surface of the base plate (1) being provided with a microperforated material layer (2) which is connected to the base plate (1) only in a strip-like or linear or punctiform manner, and a structure provided with such a sound absorber.

Description

Sound absorber, structure and use of a sound absorber

The invention relates to a sound absorber with an open-pore base plate which has a flow resistance of approximately 500 Ns / m ³ to approximately 6000 Ns / m ³ according to DIN EN 29053: 1993-05. Sound absorbers of this type are used, for example, to optimize room acoustics in buildings, vehicles or aircraft. The invention further relates to a building provided with such a sound absorber and to a use of such a sound absorber.

Sound absorbers which contain or consist of a porous material are known from practice. The porous material can be provided in the form of a fleece, a foam or a fiber layer and introduced into a room, for example. Well-known examples are wall or ceiling elements which absorb sound from at least a predeterminable frequency range and thereby the reverb

can reduce. The intelligibility of the language or the perception of music performances can be improved.

Other known sound-absorbing constructions have a micro-perforated and configurable layer on the surface, which is combined with a perforated plate. The perforated plate only has what is necessary

mechanical stability and is perforated so that the sound can penetrate through the perforation to an absorbing layer behind the plate to be absorbed. This makes the construction thicker and, with three layers, complex to manufacture.

However, these known sound absorbers have the disadvantage that the possibilities for optical design

are limited and as a result, aesthetic compromises often have to be made for acoustic optimization. Based on the prior art, the invention is therefore based on the object of providing a sound absorber which also meets high design requirements.

The object is achieved according to the invention by a use according to claim 1, a device according to claim 16 and a

Structure according to claim 29 solved. Beneficial

Further developments of the invention can be found in the sub-claims.

According to the invention, a sound absorber with an open-pore base plate is proposed. The porosity represents a dimensionless measured variable, which the

Specifies the ratio of void volume to the total volume of the base plate. The base plate should be viewed as open-pored if it has cavities that are connected to one another and to the environment. The open one

Porosity thus allows the hydraulic transport of fluids in the base plate.

According to the invention, the open-pore base plate is intended to be a

Have flow resistance of about 500 Ns / m ³ to about 6000 Ns / m ³ according to DIN EN 29053: 1993-05. This flow resistance means that sound waves can penetrate the base plate and are converted into heat there by dissipation. The base plate thus has a sound-absorbing effect in at least part of the acoustic frequency range.

According to the invention, it is now proposed that at least a partial area of the base plate with a micro-perforated Material layer is provided. In some embodiments of the invention, the partial surface can be one in the later

Use the outside facing surface of the base plate. The outside is understood to mean an area which is visible when used as intended.

In other embodiments of the invention, the base plate can be completely provided with the micro-perforated material layer. This primarily means that the whole

Surface of the base plate from the micro-perforated

Material layer is covered. However, the micro-perforated material layer does not have to be bonded with the entire surface. Rather, this can only be connected in strips, lines or points in order to vibrate surfaces of the micro-perforated material layer

enable .

The micro-perforated material layer has a plurality of bores, which on the one hand allow the penetration of a

Allow sound wave into the open-pored base plate behind the micro-perforated material layer. On the other hand, the holes in the micro-perforated material layer themselves act like a damped resonator, i.e. H. the micro-perforated material layer has, depending on the diameter of the bores or holes and depending on the thickness, at a certain frequency or a frequency band, a higher sound absorption than the open-pored base plate without micro-perforated material layer. The inventive combination of the two layers, i. The open-pored base plate and the micro-perforated material layer result in a new acoustic behavior, so that the absorption of the base plate is basically retained, but the absorption is usually improved at low frequencies.

The acoustic behavior of the structure can also be specifically influenced by the design of the micro-perforated material layer. In addition, the

The holes in the micro-perforated material layer are so small can be chosen so that these can no longer be resolved by the eye of a beholder from a conventional viewing distance of, for example, more than about 1 m to more than about 3 m and appear optically smooth. As a result, wall cladding or facade elements or partitions or furniture surfaces can be optically designed in a manner known per se

appear smooth and closed, although they have a completely different acoustic behavior than a smooth surface.

In some embodiments of the invention, the base plate of the sound absorber can have a flow resistance of more than about 2000 Ns / m ³ according to DIN EN 29053: 1993-05

exhibit. This can improve the sound absorption. In some embodiments of the invention, the base plate can have a flow resistance of approximately 2000 Ns / m ³ according to DIN EN 29053: 1993-05.

In some embodiments of the invention, the base plate can have an open porosity of from about 30% to about 99%, or from about 40% to about 80%, or from about 45% to about 60%. This open porosity allows one

reliable sound absorption, so that the sound absorber according to the invention can have high degrees of absorption and only a small proportion of sound is reflected.

In some embodiments of the invention, the base plate may have a thickness of about 6 mm to about 100 mm, or about 50 mm to about 200 mm, or about 7 mm to about 80 mm, or from about 8 mm to about 40 mm, or from about 10 mm to have about 30 mm. This can reduce the trade-off between

low weight and space requirements, mechanical stability and good sound absorption can be optimized.

In some embodiments of the invention, the micro-perforated material layer can be connected to the base plate, in particular the micro-perforated material layer can be connected to the Base plate glued, soldered or welded. In some embodiments of the invention, the micro-perforated material layer can be joined to the base plate over the entire surface. This can improve the mechanical stability of the

Sound absorber be increased.

In other embodiments of the invention, the micro-perforated material layer can only be joined to the base plate in strips or linearly or only at certain points, for example by gluing, soldering or welding. This allows the micro-perforated material layer to bend

run vibrations or surface vibrations, the base plate can act as an additional spring element of a mass / spring system formed in this way, in addition to the

Rigidity of the micro-perforated material layer. The natural frequencies of the vibrations of the micro-perforated

The material position can be influenced by the number, size and / or position of the joints. The vibrations of the micro-perforated material layer can affect the sound field

additional energy can be withdrawn, in particular also in frequency ranges in which the absorption of the base plate and / or the effect of the micro-perforation is only slight. As a result, the vibration of the microperforated material as a whole can partially reduce the effect of the absorber

Complement embodiments.

In some embodiments of the invention, the micro-perforated material layer can be arranged at a distance from the base plate. In some embodiments of the invention, the distance can be between about 1 mm and about 10 mm or

be between about 3 mm and about 8 mm. In this embodiment, the natural oscillation of the micro-perforated material layer can be less dampened by the base plate, so that the effect of the absorber can be increased.

In some embodiments of the invention, the micro-perforated material layer can have a thickness of about 0.1 mm to about 2 mm or from about 0.5 mm to about 1.8 mm or from about 0.8 mm to about 1.5 mm or from about 1 mm to about 4 mm or from about 1 mm to about 2 mm. Such a micro-perforated material layer can, on the one hand, optimize the sound absorption and / or, on the other hand, give the sound absorber high stability with low weight.

In some embodiments of the invention, the micro-perforated material layer has a plurality of bores, the diameter of which is between approximately 0.1 mm to approximately 2 mm or between approximately 0.3 mm to approximately 1.2 mm or between approximately 0.4 mm to about 0.8 mm or between about 0.8 mm to about 2.0 mm. In some embodiments of the invention, all of the bores in the microperforated material layer can have a uniform diameter. In other embodiments of the invention, the bores of the microperforated material layer can have different diameters or a distribution function of the diameters. As a result, the absorption maximum can be optimized to a predeterminable frequency or a predeterminable frequency range, so that the sound absorber can, for example, selectively attenuate room resonances.

In some embodiments of the invention, the area proportion of the bores of the microperforated material layer can be between 0.1% and approximately 10% or between approximately 1% and approximately 9% or between approximately 5% and approximately 8% of the total area. This enables, on the one hand, the visual impression of a closed or largely closed surface and, on the other hand, sufficient sound absorption so that the sound absorber according to the invention is used to optimize the room acoustics or to optimize the acoustic

Properties of a facade can be used.

In other embodiments of the invention, the area proportion of the bores of the micro-perforated material layer can be between about 0.005% and about 2% or between about 0.01% and about 1% of the total area. This enables the use of the microperforation as a broadband acting depth absorber. In some embodiments of the invention, this can have a resonance frequency of less than 120 Hz or less than 80 Hz. In some embodiments of the invention, the resonance frequency of the micro-perforation can be selected such that it is above the natural frequency of the surface oscillation of the micro-perforated material layer and below the absorption maximum of the base plate.

In some embodiments of the invention, the distance between adjacent bores in the microperforated material layer can be selected between approximately 15 mm and approximately 100 mm or between approximately 20 mm and approximately 60 mm.

In some embodiments of the invention, the micro-perforated material layer can be a melamine resin and / or a

Duroplast and / or a thermoplastic and / or a wood veneer and / or polyethylene and / or polyethylene terephthalate and / or ethyl tetrafluoroethylene copolymer and / or a metal or an alloy or consist of them. A

Metal or an alloy can be aluminum or steel

contain or consist of. Such layers of material

enable, on the one hand, a decorative design of wall or ceiling surfaces or furniture surfaces or facades and, on the other hand, are mechanically sufficiently stable to allow a long service life of the sound absorber. In addition, layers of material with low internal friction, e.g. Metals, through vibration of the micro-perforated material layer as a whole, supplement the effect of the absorber in some embodiments.

In some embodiments of the invention, the sound absorber can contain multiple base plates. These can have different properties, for example contain and / or different materials

have different thicknesses and / or different Have porosities. In some embodiments of the invention, the sound absorber can have at least two

Contain base plates, with at least one base plate being arranged on each side of the micro-perforated material layer. In some embodiments, this can be spaced on one or both sides.

In some embodiments of the invention, the base plate can be self-supporting. This facilitates assembly and transportation of the base plate. For the purposes of the present description, "self-supporting" means that the panel does not have any for the desired application

additional mechanical substructure or support or bracing is required. The plate is so stiff and stable that it can only be attached to individual fastening points and nevertheless does not change its shape appreciably over time, e.g. on the ceiling as

Ceiling cladding or on the wall as wall cladding. For wall cladding in the area of movement of students in

In schools or in sports halls, a cladding panel must also withstand mechanical forces such as impact from people. A non-self-supporting panel, on the other hand, always requires a substructure that absorbs the forces that occur in order to keep the panel permanently in shape in a certain position.

In some embodiments of the invention, the base plate can be a pressed polyester fleece and / or a

Wood-based material and / or pressed mineral wool and / or sintered glass foam and / or cement-bound expanded clay and / or a thermoset foam and / or a

Melamine resin and / or a natural fiber and / or a metal foam contain or consist of it. The base plates are therefore open-pored in order to have good acoustic properties. In addition, such base plates can also be mechanically stable in order not to be damaged during handling and assembly. In some execution Form the invention, the material of the base plate can be selected so that it complies with the usual fire resistance classes and an application in or on buildings without

Elaborate approval in individual cases is possible.

In some embodiments of the invention, the sound absorber can contain at least one mechanical reinforcement element which, for example, contains or consists of GRP and / or CFRP and / or polyethylene and / or polyester and / or wood or a wood material. In some embodiments of the invention, the reinforcing element can also contain or consist of a metal or an alloy. Such a reinforcing element can

Improve the mechanical strength of the sound absorber so that assembly and transport are made easier. For this purpose, the reinforcement element can be applied as a grid or fabric layer to the outer surface of a sound absorber, in some cases above the micro-perforated material layer or between the micro-perforated material layer and the base plate. In other embodiments of the invention, the reinforcement element can be embedded in the base plate.

In some embodiments of the invention, the sound absorber can be in a basket on a building wall or on a

Building ceiling to be attached. Such a basket can be a

Contain or consist of perforated sheet metal. Optionally, the basket can be closed at the side.

In some embodiments of the invention, the

Sound absorbers are introduced into at least one room of a building. This can be done as a wall or ceiling element, which sound at least one specifiable

Absorb the frequency range and thereby the reverb

can reduce. The intelligibility of speech or the perception of musical performances in the space of the building can be improved by using the sound absorber. In some embodiments of the invention, the

Sound absorbers on at least one outer facade of one

Structure to be attached at least to a partial area. As a result, sound can be absorbed at least in a predeterminable frequency range and the reverberation can thereby be reduced. The use on a facade is particularly advantageous in inner courtyards or atriums or on busy streets in order to reduce acoustic disturbances in the adjoining interior rooms or to expand the possibilities of use of the inner courtyard or the atrium, for example as a meeting place.

The invention is based on figures without

Limitation of the general inventive concept are explained in more detail. It shows:

Figure 1 shows a sound absorber according to the present

Invention in a first embodiment.

Figure 2 shows a sound absorber according to the present invention in a second embodiment.

Figure 3 shows in a first comparative example

Degree of absorption versus frequency.

In a second comparative example, FIG. 4 shows the degree of absorption versus frequency.

In a third comparative example, FIG. 5 shows the degree of absorption versus frequency.

In a fourth comparative example, FIG. 6 shows the degree of absorption versus frequency.

FIG. 7 shows a sound absorber according to the present invention in a third embodiment. FIG. 8 shows a sound absorber according to the present invention in a fourth embodiment.

FIG. 9 shows a sound absorber according to the present invention in a fifth embodiment.

FIG. 10 shows a sound absorber according to the present invention in a sixth embodiment.

In a fifth comparative example, FIG. 11 shows the degree of absorption versus frequency.

FIG. 12 shows the influence of the micro-perforation on the degree of absorption.

A first exemplary embodiment of a sound absorber according to the invention is explained in more detail with reference to FIG. Darge is a building part 5, for example a wall or ceiling surface, which can be made of masonry or concrete, for example. The building part 5 limits one

Interior of a building. Due to the smooth surface of the building part 5, disturbing sound reflections and long reverberation times can occur in this interior space.

A sound absorber according to the invention is used to improve the acoustic comfort. This contains a base plate 1, which for example has a thickness of about 6 mm to about 100 mm and which in some embodiments contains or consists of a pressed polyester fleece, a wood material, pressed mineral wool, sintered glass foam, cement-bound expanded clay or a thermosetting foam. As a result, the base plate is at least partially open-pored and has a flow resistance of approximately 2000 Ns / m ³ . The base plate 1 can be flat or curved. As a result, the base plate can be shaped complementary to the surface of the building on which it is to be applied.

The base plate 1 can be applied directly to the surface of the building part 5, for example by gluing or by mechanical fasteners, for example screws and dowels. In other embodiments of the invention, the base plate 1 can be arranged at a distance from the building part 5, so that an optional space 4 results, which is a height of about 2 cm to about 20 cm or from about 2 cm to about 40 cm or about 5 cm can have up to about 10 cm.

In order to ensure the mechanical stability of the base plate 1, it can have optional reinforcing elements 15. The reinforcement element 15 can be embedded in the base plate 1, for example, in the form of an elongated stiffener or a grid. The reinforcement element 15 can also be used as a holder to reliably secure the sound absorber to the building part 5

attach. In other embodiments of the invention, the base plate itself can be sufficiently mechanical

Have stability, so that reinforcing elements 15 can also be omitted.

The space 4 can optionally be completely or partially filled with sound-absorbing material.

At least the partial surface of the base plate 1 that is visible when used as intended is provided with a micro-perforated material layer 2. The material layer 2 contains a plurality of bores or holes 20 which can be arranged in a uniform or irregular pattern and which can each have a diameter of approximately 0.1 mm to approximately 2 mm. The total area of the

Bores 20 can be about 0.1% to about 10% of the total, at The visible surface of the sound absorber corresponds to the intended use.

The micro-perforated material layer 2 is in the first

Embodiment connected over the entire surface to the base plate 1, for example by gluing. The micro-perforated material layer can consist of plastic or wood or metal and thus enable a desired surface design of the sound absorber.

The rear side of the base plate 1 facing the building part 5 or the intermediate space 4 is not provided with a micro-perforated material layer 2.

The micro-perforated material layer 2 is in this

Embodiment due to its connection with the

Base plate 1 itself cannot vibrate, i.e. of the

Sound absorber is based on the following mechanisms of action: On the one hand, sound waves can pass through the micro-perforated

Material layer 2 penetrate into the base plate 1 and are dissipated there. This mechanism of action dominates at higher frequencies. On the other hand, the air enclosed in the bores 20 of the microperforated material layer 2 can be excited to vibrate by incident sound waves and thereby dissipate energy from the sound field. This mechanism of action dominates at lower frequencies. In some embodiments of the invention, it can also be omitted or only weakly pronounced. Both mechanisms of action can therefore have different absorption spectra and thus complement each other.

In other embodiments of the invention, the

sound absorbers shown, i.e. the base plate 1 with optional reinforcement elements 15 and the micro-perforated material layer 2 applied over the entire surface also for other applications than the ceiling panel shown

be used, for example, as wall cladding or as the interior lining of a vehicle or aircraft, as a mobile partition or partition or in furniture construction or as

Facade element of a building.

Figure 2 shows a second embodiment of a fiction, contemporary sound absorber. The same components of the invention are provided with the same reference symbols, so that the following description is limited to the essential differences.

FIG. 2 shows a detail from the cross section through a base plate 1. This is not only partially, but over its entire area, with a micro-perforated material layer 2. The micro-perforated material layer 2 thus also covers the side edges and the side of the base plate 1 facing the building part 5.

It can also be seen from FIG. 2 that the optional reinforcement elements 15 are not embedded in the base plate, but rather as a grid between the micro-perforated ones

Material layer 2 and the base plate 1 are introduced. The reinforcement element 15 can thus also be connected to the base plate by gluing or welding.

The micro-perforated material layer 2 is also in this

Embodiment due to its connection with the

Base plate 1 or the reinforcing element 15 itself not capable of vibrating, i.e. Like the first embodiment, the sound absorber is based on the following mechanisms of action: On the one hand, sound waves can pass through the micro-perforated

Material layer 2 penetrate into the base plate 1 and are dissipated there. The other can be in some

Embodiments additionally, the air enclosed in the bores 20 of the micro-perforated material layer 2 are excited to vibrate by incident sound waves and thereby dissipate energy from the sound field. Both Mechanisms of action can have different absorption spectra and thus complement each other.

The first and second embodiment shown in Figures 1 and 2 are collectively referred to as sound absorbers of the first type due to their identical mechanisms of action. Comparative examples between different sound absorbers of the first type versus known sound absorbers are explained with reference to FIGS. 3 - 6 described below.

Also the sound absorber shown in Figure 2, i. the base plate 1 with optional reinforcement elements 15 and the fully applied micro-perforated material layer 2 can be used as a wall or ceiling panel of a building, as the interior cladding of a vehicle or aircraft, as a mobile partition or partition or in furniture construction or as a facade element.

Figure 3 shows a first comparative example of a

sound absorber according to the invention. It is shown

Degree of absorption on the ordinate and the frequency of an incident sound on the abscissa. Here, curve A shows the degree of absorption of a plate known per se made of a melamine resin foam with a thickness of 10 cm. Curve B shows an identical base plate made of melamine resin foam with a thickness of 10 cm, which, however, was additionally provided with a fully bonded micro-perforated material layer according to the present invention on the entry side of the sound.

As can be seen from FIG. 3, the micro-perforated material layer improves the sound absorption in the range from about 100 Hz to about 300 Hz, so that in addition to an aesthetic surface design, the sound absorber also has an improved effect. Figure 4 shows a second comparative example. As in FIGS. 5 and 6 described below, the degree of absorption of a pressed mineral wool panel is again plotted on the ordinate and the frequency on the abscissa. Curve A shows the degree of absorption of a mineral wool panel with a thickness of 2 cm, which was installed in front of a building part 5 with a gap 4 of 10 cm. Curve B again shows the degree of absorption after the

Mineral wool panel has been provided with a micro-perforated material layer over the entire surface. As can be seen from Figure 4, the absorption behavior of the deteriorates

Sound absorber not, with simultaneously improved

optical and aesthetic properties.

A third comparative example is explained with reference to FIG. In this case curve A shows the degree of absorption versus frequency for a pressed fleece made of polyether sulfone (PES). The fleece has a thickness of 5 cm and is mounted with a distance or space 4 of 5 cm to the building part 5.

In this case, too, curve B shows the degree of absorption versus frequency for the fleece after it has been provided with a micro-perforated material layer that is glued over the entire surface. In this case, too, there is a higher absorption in the range from approximately 150 to approximately 250 Hz, so that the sound absorber according to the invention has not only improved optical properties, but also improved acoustic properties in the low frequency range.

In the fourth comparative example according to FIG. 6, the same pressed fleece layer is used as in the example shown in FIG. However, this is at a greater distance of 10 cm from the surface of the

Building part 5 mounted. This changes that

Absorption behavior especially for frequencies above about 800 Hz. Curve B again shows the fleece provided with a micro-perforated material layer.

FIG. 7 shows a sound absorber according to the present invention in a third embodiment. Same

Components of the invention are provided with the same reference symbols, so that the following description is limited to the essential differences.

The third embodiment also has a base plate 1 which, for example, contains or consists of an open-pored foam, a fiber layer, a knitted fabric, a knitted fabric or another sound-absorbing material known per se. The base plate 1 is designed with open pores so that sound waves can penetrate and their energy is dissipated in the base plate.

The base plate 1 is attached to a building part 5, for example a ceiling or an inner wall or an outer wall. The side of the base plate 1 opposite the building part is provided with a micro-perforated material layer 2. In contrast to the first and second embodiments of the invention described above, the micro-perforated material layer 2 according to the third, fourth, fifth and sixth embodiment is not connected to the base plate 1 over the entire surface. Rather, the micro-perforated material layer is connected to the base plate in strips, lines or at points. In some

In embodiments of the invention, the connection can only take place via the edges, so that the surface of the micro-perforated material layer 2 has no connection to the base plate 1. In yet other embodiments of the invention, there can be no mechanical or material connection between the micro-perforated material layer 2 and the base plate 1. This feature enables

Surface vibrations of the micro-perforated material layer 2. In addition to the two above in connection with the First and second embodiment described mechanisms of action, the third, fourth, fifth and sixth embodiments of the invention can additionally also dissipate sound energy by the microperforated

Material layer as a whole is excited to surface vibrations and thus energy is dissipated from the sound field. The micro-perforated material layer in the third

Embodiment have a thickness of about 1 mm to about 4 mm or from about 1 mm to about 2 mm. The micro-perforated material layer preferably has little internal damping and is made, for example, of a metal, an alloy or a thermosetting plastic. In some embodiments of the invention, the micro-perforated material layer 2 can be a sandwich construction made up of several material layers in order to adapt the vibration behavior to desired target values.

The micro-perforated material layer 2 has bores 20 which have a diameter of approximately 0.8 mm to approximately 2 mm and a distance between adjacent holes of approximately 15 mm to approximately 100 mm. As a result, the microperforation can be tuned as a broadband acting depth absorber with a resonance frequency of less than about 150 Hz or less than about 80 Hz. The broadband acting deep absorber is therefore mainly effective in the low frequency range. This is followed by the resonance of the surface oscillation of the micro-perforated material layer 2. Finally, in the high frequency range, the absorption of the base plate 1 is for the

Determining absorption behavior. Since the third embodiment shown in FIG. 7 thus combines three active mechanisms in a single sound absorber, this is referred to below as a sound absorber of a second type, in contrast to the embodiments of the invention described with reference to FIGS. 1 and 2.

The base plate 1 and / or the micro-perforated material layer 2 can be fastened in a basket 6 on the building part 5.

The basket 6 can for example be made of a wire mesh or be made of a perforated sheet and be open or closed at the edges. The basket 6 can optionally contain a trickle protection, which can be designed as a flow layer. Since the basket 6 the sound absorber mechanical

Provides stability, there is greater freedom in an embodiment with such a basket 6 in the selection of the base plate 1. This does not necessarily have to be self-supporting. However, it should be pointed out that the basket 6 is optional and can also be omitted in other embodiments of the invention.

In other embodiments of the invention, the

sound absorbers shown, i.e. the base plate 1 with optional reinforcing elements 15 and the strip-shaped, linear or point-wise connected to the base plate micro-perforated material layer 2 can also be used for other applications than the ceiling panel shown in or on a building, for example as the interior lining of a vehicle or aircraft, as a mobile positioning or partition wall or in furniture construction.

A fourth embodiment of the invention is explained in more detail with reference to FIG. Same components of the

Invention are provided with the same reference numerals, so that the following description is limited to the essential differences from the third embodiment described above with reference to FIG.

As can be seen from FIG. 8, the micro-perforated material layer 2 does not lie on the base plate 1. Rather, there is a spacing 7 between the base plate 1 and the micro-perforated material layer 2. In some embodiments of the invention, this can be between approximately 1 mm and approximately 10 mm or between approximately 3 mm and approximately 8 mm

be. This feature has the effect that the

Natural vibration of the micro-perforated material layer is less influenced by the base plate, so that the effect of the absorber can be increased. That between the micro-perforated material layer 2 and the building part 5 in the

However, the volume of air enclosed in the base plate 1 still acts as a restoring force on the oscillation of the micro-perforated material layer 2, so that the natural frequency of the material layer 2 and thus the absorption behavior of the sound absorber can be optimized or adapted by choosing the distance 7.

A fifth embodiment of the invention is described with reference to FIG. The fifth embodiment of the

The invention differs from the third embodiment in that the basket 6 is enlarged so that a porous foam, a knitted fabric, a knitted fabric or a fiber layer can be arranged on both sides of the micro-perforated material layer 2. Starting from the surface of the building part 5, the base plate 1 is thus initially arranged directly on the upper surface of the building part 5. On the building part 5 opposite side of the base plate 1, the micro-perforated material layer is applied as described above. A first additional plate 11 comes to rest on the side of the micro-perforated material layer 2 opposite the base plate 1. An optional second additional plate 12 is applied to the first additional plate 11. Sound energy that hits it is thus initially absorbed by the first and second additional plates 11 and 12. depth

Frequencies which the additional plates 11 and 12 can pass stimulate the micro-perforated material layer 2

Surface vibrations, which absorb further sound energy in the medium frequency range. Low frequencies below approximately 80 Hz can be absorbed by the volume of air enclosed in the bores 20 of the micro-perforated material layer 2. If high-frequency vibrations still reach the base plate 1, they are absorbed there. Essentially, however, the base plate 1 serves to dampen the vibrations of the micro-perforated material layer 2 and to dissipate energy. Since the micro-perforated material layer 2 is in contact both with the first additional plate 11 and with the base plate 1, an additional mechanical or material

conclusive attachment by gluing, soldering or welding is omitted. The four material layers shown in FIG. 9 can be held in the basket 6 solely by their own weight and attached to the building part 5 with this.

A sixth embodiment of the invention is explained in more detail with reference to FIG. Figure 10 shows a cross section through a sound absorber according to the invention. The sixth embodiment represents a combination of the fifth embodiment described above with the fourth

Embodiment.

As can be seen from FIG. 10, the sixth embodiment also comprises at least a first additional plate 11 and an optional second additional plate 12, which can be made of a different material and / or can have a different thickness, so that the additional plates 11 and 12 have an absorption maximum different frequencies

exhibit. In the fifth embodiment described above, the material properties of the first and second additional plates 11 and 12 can also be selected accordingly.

The essential difference between the sixth embodiment and the fifth embodiment is that there is a distance 7 between the base plate 1 and the micro-perforated material layer 2 and / or between the micro-perforated material layer 2 and the first additional plate 11. The distance 7 can be, for example, between approximately 1 mm and approximately 10 mm. For this purpose, the micro-perforated material layer 2 is connected to the basket 6 by holding elements 25. As a result, the micro-perforated material layer 2 can vibrate freely and thus with a greater amplitude and / or less damping and thus dissipate a higher proportion of the incoming sound energy.

Using FIG. 11, the effect of the sound absorber according to the invention is explained in a fifth comparative example. The degree of absorption is again plotted on the

Ordinate and frequency on the abscissa. Curve A shows an absorber according to the prior art, which has a construction similar to that shown in FIG

Sound absorber. The sound absorber according to FIG. 9 has a base plate 1, in front of which an oscillatable

Material layer 2 is arranged. In addition, before the

Material layer 2 a further base plate 11 and / or

Base plate 12 arranged. However, the material layer 2 has no microperforations or no bores 20. As FIG. 11 shows, this sound absorber has a first one

Resonance frequency at around 125 Hz. At around 150 Hz, an undesirable minimum in the absorption behavior is formed. The absorption of the base plate 11 and / or 12 only takes effect at significantly higher frequencies from around 200 Hz. Such an absorption behavior shown in curve A can result

cause unwanted roar in the room, if single

Frequencies are attenuated less strongly than neighboring frequencies. By attaching the invention

Micro-perforation in the material layer 2 changes that

Absorption behavior with otherwise unchanged structure as shown in curve B. As can be seen from FIG. 11, the resonance shifts to lower frequencies, in the present example to about 80 Hz. The resonance becomes broader and less pronounced. That in curve A.

Visible minimum of the absorption behavior is largely smoothed out by the micro-perforation according to the invention.

On the basis of FIG. 12, in a sixth comparative example, the effect of the microperforation in a sound absorber of the second type according to the present invention is shown again

Invention explained. Curve C again shows the absorption behavior of a sound absorber which roughly corresponds to the structure according to FIG. 7 with a laterally closed basket, but has no bores 20 or no micro-perforations in the material layer 2. The material layer 2 consists of a steel sheet with a thickness of 1.25 mm. The base plate 1 contains a melamine resin foam and has a thickness of 100 mm. As can be seen from FIG. 12, such a known sound absorber has a strong one

Increase in the absorption behavior at a resonance frequency of about 100 Hz. The absorption behavior drops sharply on both sides of the resonance frequency.

Curves D and E show the absorption behavior of a nominally identical sound absorber which, however, has been provided with the microperforation according to the invention. The sound absorbers according to curves D and E thus all have three mechanisms of action which characterize the second type of sound absorber according to the invention. In

Depending on the number or the spacing of the bores, the resonance frequency of the micro-perforated material layer 2 can be shifted to higher or lower frequencies. As especially curve D shows, the

Resonance frequency also be broadened so that the

Absorption behavior up to comparatively high frequencies of 500 Hz is sustainably improved.

The absorption behavior shown in curve D was obtained with a material layer 2 which is made of sheet steel, has a thickness of 1.25 mm and a wall distance of 100 mm. 1 mm holes were made in the material layer 2

Introduced diameter, which are each 22 mm apart. The perforated area is therefore

0.16%.

The absorption behavior shown in curve E was obtained with a material layer 2 which is made of sheet steel, a thickness of 1.25 mm and a wall distance of 100 mm having. 1 mm holes were made in the material layer 2

Introduced diameter, which are each 35 mm apart. The perforated area is therefore

0.064%.

Of course, the invention is not limited to the embodiments presented Darge. The above description is therefore not to be regarded as restrictive but rather as explanatory. The following claims are to be understood in such a way that a named feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. If the claims and the preceding description define “first” and “second” embodiments, this is used

Designation of the distinction between two similar types of execution without defining a priority.

Claims

Expectations

1. Using a sound absorber in or on a

Building, wherein the sound absorber has an open-pored base plate (1), which has a flow resistance of about 500 Ns / m ³ to about 6000 Ns / m ³ according to DIN EN

29053: 1993-05, characterized in that at least one partial area of the base plate (1) is provided with a micro-perforated material layer (2).

2. Use according to claim 1, characterized in that the base plate (1) has a flow resistance of more than about 2000 Ns / m ³ according to DIN EN 29053: 1993-05 or

that the base plate (1) has a flow resistance of about 2000 Ns / m ³ according to DIN EN 29053: 1993-05.

3. Use according to claim 1 or 2, characterized in that the base plate (1) has an open porosity of about 30% to about 99% or from about 40% to about 80% or from about 45% to about 60%.

4. Use according to one of claims 1 to 3, characterized in that the base plate (1) has a thickness of about 6 mm to about 100 mm or about 50 mm to about 200 mm or about 7 mm to about 80 mm or about 8 mm to about 40 mm or from about 10 mm to about 30 mm.

5. Use according to one of claims 1 to 4, characterized in that the micro-perforated material layer (2) is connected to the base plate (1).

6. Use according to claim 5, characterized in that the micro-perforated material layer (2) is glued and / or welded and / or to the base plate (1)

is soldered and / or

that the micro-perforated material layer is only strip or linearly or only selectively connected to the base plate (1) or

that the micro-perforated material layer is fully connected to the base plate (1).

7. Use according to one of claims 1 to 4, characterized in that the micro-perforated material layer (2) is arranged at a distance from the base plate (1).

8. Use according to one of claims 1 to 7, characterized in that the micro-perforated material layer (2) has a thickness of about 0.1 mm to about 2 mm or from about 0.5 mm to about 1.8 mm or from about 0.8 mm to about 1.5 mm or from about 1 mm to about 4 mm or from about 1 mm to about 2 mm.

9. Use according to one of claims 1 to 8, characterized in that the micro-perforated material layer (2) has a plurality of bores (20) whose

Diameters in each case between about 0.1 mm to about 2 mm or between about 0.3 mm to about 1.2 mm or between about 0.4 mm to about 0.8 mm or between about 0.8 mm to about 2.0 mm.

10. Use according to one of claims 1 to 9, characterized in that the surface portion of the bores (20) of the micro-perforated material layer (2)

between about 0.1% and about 10% or

between about 1% and about 9% or

between about 5% and about 8% or

between about 0.005% and about 2% or

between about 0.01% and about 1%

that of the total area.

11. Use according to one of claims 1 to 10, characterized in that the distance between adjacent bores of the micro-perforated material layer is selected between about 15 mm and about 100 mm or between about 20 mm and about 60 mm.

12. Use according to one of claims 1 to 11, characterized in that the micro-perforated material layer (2) is a melanin resin and / or a thermoset and / or a

Thermoplastic and / or a wood veneer and / or polyethylene and / or polyethylene terephthalate and / or ethylene-tetrafluoroethylene copolymer and / or a metal or an alloy and / or steel and / or aluminum or consists of it.

13. Use according to one of claims 1 to 12, characterized in that the base plate (1) is self-supporting.

14. Use according to one of claims 1 to 13, characterized in that the base plate (1) is a pressed polyester fleece and / or a wood material and / or pressed mineral wool and / or sintered glass foam and / or cement-bound expanded clay and / or a

contains or consists of thermosetting foam and / or a melamine resin and / or a natural fiber material and / or a metal foam.

15. Use according to one of claims 1 to 14, further comprising at least one mechanical reinforcing element (15), which for example contains or consists of GRP and / or CFRP and / or polyethylene and / or polyester and / or wood or a wood material.

16. Sound absorbers with at least one open-pored base

Plate (1) which has a flow resistance of about 500 Ns / m ³ to about 6000 Ns / m ³ according to DIN EN 29053: 1993-05, characterized in that

at least one partial area of the base plate (1) is provided with a micro-perforated material layer (2) which is only connected to the base plate (1) in strips or lines or at points.

17. Sound absorber according to claim 16, characterized in that the base plate (1) has a flow resistance of more than about 2000 Ns / m ³ according to DIN EN 29053: 1993-05 has or

18. Sound absorber according to claim 16 or 17, characterized in that the base plate (1) has an open porosity of about 30% to about 99% or from about 40% to about 80% or from about 45% to about 60%.

19. Sound absorber according to one of claims 16 to 18,

characterized in that the base plate (1) has a thickness of about 6 mm to about 100 mm or about 50 mm to about 200 mm or about 7 mm to about 80 mm or from about 8 mm to about 40 mm or from about 10 mm to has about 30 mm.

20. Sound absorber according to one of claims 16 to 19,

characterized in that the micro-perforated

Material layer (2) is glued and / or welded and / or soldered to the base plate (1).

21. Sound absorber according to one of claims 16 to 20,

characterized in that the micro-perforated

Material layer (2) has a thickness of about 0.5 mm to about

1.8 mm or from about 0.8 mm to about 1.5 mm or from about 1 mm to about 4 mm or from about 1 mm to about 2 mm.

22. Sound absorber according to one of claims 16 to 21,

characterized in that the micro-perforated

Material layer (2) has a plurality of bores (20), the diameter of which is between approximately 0.1 mm to approximately 2 mm or between approximately 0.3 mm to approximately 1.2 mm or between approximately 0.4 mm to approximately 0, 8 mm or between about 0.8 mm to about 2.0 mm.

23. Sound absorber according to one of claims 16 to 22,

characterized in that the area proportion of the

Holes (20) of the micro-perforated material layer (2) amounts to between about 5% and about 10% or between about 6% and about 8% of the total area.

24. Sound absorber according to one of claims 16 to 23,

characterized in that the distance between adjacent bores of the micro-perforated material layer is selected between approximately 15 mm and approximately 100 mm or between approximately 20 mm and approximately 60 mm.

25. Sound absorber according to one of claims 16 to 24,

characterized in that the micro-perforated

Material layer (2) a melamine resin and / or a thermoset and / or a thermoplastic and / or a wood veneer and / or polyethylene and / or polyethylene terephthalate and / or ethylene-tetrafluoroethylene copolymer and / or a metal or an alloy and / or steel and /or

Contains or consists of aluminum.

26. Sound absorber according to one of claims 16 to 25,

characterized in that the base plate (1)

is self-supporting.

27. Sound absorber according to one of claims 16 to 26,

characterized in that the base plate (1) is a pressed polyester fleece and / or a wood material and / or pressed mineral wool and / or sintered glass foam and / or cement-bound expanded clay and / or a thermosetting foam and / or a melamine resin and / or a natural fiber and / or one

Contains or consists of metal foam.

28. Sound absorber according to one of claims 16 to 27,

furthermore containing at least one mechanical reinforcement element (15), which for example contains or consists of GFK and / or CFK and / or polyethylene and / or polyester and / or wood or a wood material.

29. Building with a sound absorber according to one of the claims

16 to 28.