RU2772035C1 - Panel, system and application for a hidden sound-absorbing surface and the method for its implementation - Google Patents

Abstract

FIELD: construction industry.

SUBSTANCE: present invention relates to a panel (100) with one or more perforations (140) containing a front surface (120) in which the Cm contrast between the front surface (120) and the specified one or more perforations (140) is less than 0.3, a sound-absorbing system containing a panel (100) and a masking layer (160), while the masking layer (160) is breathable, and the use of the specified panel or sound-absorbing system.

EFFECT: expansion of the range of sound-absorbing solution.

15 cl, 6 dwg

Description

Technical field

The present invention relates to a panel according to Claim 1, a sound absorbing system according to Claim 9, and the use of a panel or sound absorbing system according to Claim 14.

This application claims benefit from international patent application PCT/EP 2018/000581 dated December 21, 2018, which is incorporated herein by reference in its entirety and in particular with reference to specific embodiments and features described below.

State of the art

Room acoustics are an important factor to consider when constructing or renovating a building. Many public institutions, such as classrooms and lecture halls, have strict rules regarding room acoustics that must be followed, while rooms such as offices and apartments require noise control for comfort or even health, especially when choosing furniture. in the style of minimalism. In addition, room acoustics are a variable that must be carefully controlled in environments such as theaters and music venues to obtain optimal conditions for their intended use.

The key factor used to indicate the acoustic characteristics of a room is the reverberation time. Reverberation time refers to the amount of time it takes for sound to disappear in an enclosed space. Indoors, sounds can reverberate when sound waves are not absorbed by the surfaces they come in contact with, and are instead reflected off said surfaces within an enclosed space.

This reverberation time can be reduced by modifying the surfaces in such a way that sound in the respective frequency range is absorbed more and hence such reflections are minimized. For this effect, an open-cell sound-absorbing material such as mineral fiber/wool, polyester fiber or felt can be used.

To improve the acoustic performance of a room in the required environments, such sound-absorbing materials can be used on wall, ceiling, and even floor surfaces. These sound-absorbing materials may be sold with a finished surface, such as mineral fiber ceilings, or this surface may be made at the time of installation of these materials, for example, on a perforated plasterboard ceiling, which is attached to a suspension system of metal profiles or wooden battens with a mineral fiber backing. cotton wool.

The perforated surfaces of the sound-absorbing material allow air to pass through the material and increase the sound-absorbing surface. The holes provide sound absorbing properties that can be used to control room acoustics. Said openings may provide acoustic damping effects to the environment in which they are installed. These holes may have any variety of cross-sectional shapes, such as rectangular, square or round. Since openings in a material, panel or slab play a large role in providing the sound deadening effects of that material, the distribution and size of the holes can thus be chosen to provide the desired sound dampening effects for the chosen environment.

An example of a perforated surface is the Knauf Cleaneo Akustikplatte acoustic board. The best soundproofing effect can be achieved with a complete system containing perforated gypsum boards with laminated film or fiber fleece on the side facing the wall or ceiling and with mineral wool placed at the back. Such a structure also includes fasteners or elements for attaching these boards to a wall or ceiling.

Perforated sound absorbing panels such as Knauf Cleaneo Akustikplatte or Knauf Cleaneo Acoustic Linear Panels can be hung from the ceiling, while mineral fiber panels are often held in place by a trellis structure surrounding the edges of the individual panels. The sound absorbing material can be laid out in such a way as to largely hide these edges and make the surface look like a smooth wall or ceiling.

However, the undesirable effect remains that the perforated surface has a large number of visible holes. Usually these holes appear quite dark (sometimes even black) to the observer, especially when the front surface of the ceiling is white (which is very common). The solution to cover visible openings with a masking layer, depending on this masking layer, may lead to a reduction in the sound-absorbing effect due to the masking layer reducing at least to some extent the flow of air passing into the sound-absorbing material. Such a masking layer can be made in accordance with the Knauf Cleaneo SYSTEXX system. This system uses rather expensive reflective foil to increase the visual masking effect. Thanks to this foil, the perforations in the panel should at least to some extent be invisible. In addition, in order to obtain advantageous acoustic properties, this foil contains a plurality of very small apertures.

However, such a reflective foil modified with a plurality of small holes is rather expensive and difficult to handle. In addition, once installed, it cannot be easily replaced.

As a general rule, the more or thicker layers required to mask holes/perforations, the more the sound damping effect is reduced.

Thus, the problem remains of hiding or masking a large number of visible openings in an easy and easily replaceable way, for example in a perforated panel sound absorbing ceiling or in other locations where perforated panels are used (for example in partition wall systems), without reducing the no sound absorbing effect.

Another problem to be solved is the easy replacement of the masking layer on the perforated panel without compromising the sound deadening effect.

These problems are solved by the panel of claim 1, the sound-absorbing system of claim 8, and the use of the panel or sound-absorbing system of claim 13.

Disclosure of the essence of the invention

In particular, this drawback is overcome by a panel with one or more perforations, comprising a front surface, wherein the contrast Cm between the front surface and said one or more perforations is less than 0.3.

The advantages are to reduce the visible contrast between the perforations and the panel surface without the use of costly reflective foils, while at the same time allowing the masking layer to be easily reapplied and easily replaced if necessary. In addition, such a masking layer can be thinner than the prior art solution, while still masking the openings in the panel and not reducing sound absorption performance as much as more or thicker masking layers would.

In addition, the sound absorption performance of a ceiling containing a panel according to the present invention is improved compared to a (closed, white) ceiling without a perforated panel, although their appearance is the same since the perforations are (substantially) invisible.

In a perforated panel, a perforated (or through) hole and part of the surface of this panel may alternate. Such a perforated panel has at least some height such that, in any configuration, less light (considered to be coming from the same side of the panel as the observer) enters the perforations than the surface of the panel. Thus, for the observer on the panel, there is (in the first approximation) only one dark and only one bright feature, and they can occupy quite similar or comparable parts of the area. In the explanatory notes to this application, the brightness of the perforation hole is considered to be the dark brightness L _d . However, configurations are possible in which the perforation has a light brightness L _b , for example, when the front surface of the panel is completely black, the perforation may have a (slightly) higher brightness than the panel surface.

Thus, in such a panel, the contrast can be appropriately expressed as the Michelson contrast (also known as visibility or modulation). The Michelson contrast is defined as follows

,

,

where L _b and L _d represent the high (here: light feature; panel) and low (here: dark feature; punch hole) luminance L. The denominator is twice the average of the luminances L _b and L _d . In general, C _m may refer to the contrast of the (periodic) signal L with respect to its average value. If L _b is equal to L _d , then there is no contrast because the numerator is 0, and thus C _m = 0.

Luminance L can be measured with a luminance meter, for example "Gossen MAVO-SPOT2 USB M508G". To obtain correct results, L _b and L _d should be measured simultaneously. Therefore, the values of C _m are always in the range from 0 to 1.

Also, for matte or soft and diffusely reflective surfaces, relative brightness Y can be used instead of luminance L. For a completely black surface (no light is reflected) and a completely white surface (all light is reflected), the relative luminance Y is set to 0. , use luminance L or relative luminance Y, the absolute values are the same.

To obtain a sufficiently low contrast between the perforations and the (front) surface of the panel, a C _m value of less than 0.3 is advantageous. However, even greater advantage is provided when the value of C _m is less than 0.2, preferably less than 0.1, more preferably less than 0.05.

In addition, it should be noted that (daylight) lighting also has some influence. Thus, in a rather dark room, due to low illumination, even a rather high contrast C _m = 0.4 or more may seem to the observer to be smaller than it is. However, for the present invention, sufficiently bright lighting is preferred, which makes masking the perforations in the panel more difficult. However, the present invention also works in daylight or (artificial) office lighting or any other artificial lighting used to illuminate buildings.

In one aspect of the present invention, the panel may comprise a panel material, wherein the panel material preferably comprises gypsum, fiberglass, mineral wool, or a fiber/gypsum mixture. Thus, the panel may preferably be gypsum board, gypsum board or insulation board, more preferably gypsum board. The thickness of the panel may preferably be less than 30 mm, more preferably less than 20 mm, most preferably less than 15 mm. However, in the present invention, a panel of any size and any design with perforations can be used. However, it is possible to use even a panel made of wood or plastic.

Preferably, the front surface of the panel may be

- the surface of the panel material,

the surface of the front outer layer of the panel, the front outer layer being preferably a cardboard layer or a non-woven material, more preferably a cardboard layer,

the surface of a coating layer, preferably paint, the coating layer being preferably applied to the surface of the panel material or to the surface of the front outer layer of the panel, or

the surface of the bonding layer, the receiving layer being preferably attached to the panel material or to the front outer layer of the panel.

However, while different materials and/or functions are accompanied by the aforementioned different panel fronts, they all fall within the Cm _contrast between them and the perforations of less than 0.3. Therefore, it is advantageous if the panel material, the front skin layer, the cover layer and/or the tie layer contain pigments, preferably dark pigments, more preferably dark gray pigments or black pigments. The various options are described below:

If the front surface of the panel is the surface of the panel material, this means that the panel material may have a contrast of less than 0.3 with respect to the perforations of that panel. This is possible, for example, in gypsum board when, for example, dark pigments (eg black or gray) are mixed into the mixture that is used to create the gypsum board. Thus, any level of brightness can be achieved, at least lower than without dark pigments, so that the required contrast C _m of less than 0.3 can be achieved. One advantage here is that no additional panel modification steps need to be performed to achieve the desired contrast C _m of less than 0.3, since the panel itself already has sufficient brightness (or relative brightness) after fabrication.

If the front surface of the panel is the surface of the front outer layer of the panel, this means that the front outer layer may have a contrast of less than 0.3 with respect to the perforations of the panel. This is possible, for example, in a gypsum board containing a front outer layer, usually a layer of cardboard. In the production of perforated gypsum boards, the slurry (which contains the plaster) is usually covered on both sides with a layer of cardboard. Thus, in addition to the front outer layer, there is usually also a rear outer layer. After drying (and cutting to specific dimensions), perforations are made in the gypsum board. Thus, when a panel is perforated, not only the material of the panel is perforated, but also the paperboard layer. Cardboard layers used in gypsum boards can be made in any desired color and brightness. Thus, it is possible to produce board layers having a C _m contrast of less than 0.3 with respect to the perforations of the panel, for example by using dark pigments (eg black or gray) in the production of the board layers. However, the same applies to other front outer layers, such as, for example, as non-woven materials. One of the advantages here is that no additional panel modification steps need to be performed to achieve the required contrast C _m less than 0.3, since the panel itself already has sufficient brightness (or relative brightness) after production due to the use of a front outer layer as a coating, for example, cardboard or non-woven fabric.

However, other panels are possible having only a front outer layer (eg non-woven fabric) while not having a back outer layer.

If the front surface of the panel is the surface of a coating layer, preferably paint, the coating layer being preferably applied to the surface of the panel material or the surface of the front outer layer of the panel, this means that the coating layer may have a contrast of less than 0.3 with respect to the perforations of the panel. This can be done by simply painting the panel (meaning that either the panel material or the cardboard layer is painted) a dark color such as grey, preferably dark grey, which can be very similar to the color of the panel's perforations, especially in the assembled state. . An additional step is needed here. However, the advantage here is that it is possible to decide with a long delay which ink (colour, brightness, etc.) should be used. In addition, the paint almost does not increase the thickness. In addition, the coating layer may be applied after said one or more perforations have been made in the panel, so that the coating (eg, paint) may be preserved. Also, in some cases it may be easier to make standard panels (eg gypsum boards) without pigments in the outer layer(s) and then coat the front outer layer.

If the front surface of the panel is the surface of the tie layer, with the tie layer preferably attached to the material of the panel or to the front outer layer of the panel, this means that the tie layer can have a contrast of less than 0.3 with respect to the perforations of the panel. This can be achieved by using a dark material for the tie layer, for example a material with pigments, for example dark gray or black pigments.

Preferably the tie layer may comprise plastic, more preferably the tie layer may comprise polypropylene, most preferably the tie layer may be composed of polypropylene. More preferably, the tie layer is a polymeric foil or film, most preferably a polymeric film. Particularly preferred is a dark resin film, ie a resin film with dark pigments, so that the bonding layer can have a contrast of less than 0.3 with respect to the perforations of the panel. Even more preferred is a dark polymeric film having a thickness of 0.3 to 0.6 mm, preferably 0.4 to 0.5 mm. The preferred density may be from 100 g/m ² to 200 g/m ² , preferably from 120 g/m ² to 180 g/m ² , more preferably from 140 g/m ² to 160 g/m ² . The advantages are that the polymer film is cheap, thin and easy to handle.

Such a tie layer may contain one or more perforations, preferably at substantially the same locations as the panel. Preferably, the tie layer can be attached, preferably glued, to the panel, preferably either to the material of the panel or to the front outer layer of the panel. Preferably, the tie layer can be attached, preferably glued, to the panel before perforations are made in that panel, so that the perforations in the panel and in the tie layer can preferably be made in one step. This has the advantage of saving time in the manufacturing process and also ensures that the perforations in the panel and in the bonding layer are (substantially) in the same location.

Another option is that such a tie layer may contain a plurality of micro-perforations. These micro-perforations can be made, for example, with a spiked roller. Thanks to such perforations micro-holes, sufficient airflow is possible.

In a particularly preferred embodiment, the tie layer may comprise a plurality of hooks, a plurality of gripping surface features, preferably loops, or a plurality of mushroom rods, preferably a plurality of hooks. With any of these features, it is possible to attach the mask layer to the panel in a detachable manner. Hooks, gripping surface features, preferably loops or rods, can be very small and can also be spaced very close to each other. Particularly preferred is, for example, a dark polymer film, i.e. a dark pigmented polymer film, which contains a plurality of hooks, a plurality of loops or a plurality of mushroom rods, preferably a plurality of hooks, such that the bonding layer can have a contrast of less than 0.3 with respect to panel perforations.

In general, plurality is defined as the state of plurality, with plural being the opposite of singular. So set means any number greater than 1, i.e. 2, 3, 4, etc. Most often, a set is a very large, almost uncountable number. The person skilled in the art is aware of this. With regard to hooks, loops or rods, this means that the plurality can be at least 100, preferably at least 200 hooks, loops or rods per 1 cm ² layer. In a particularly preferred embodiment, there are approximately 300 hooks, loops or rods per 1 cm ² layer. From these quantities, one can roughly estimate the dimensions of hooks, loops or rods and the distance between them.

As described above, one of the objectives of the present invention is to hide or mask visible holes or perforations in a panel without losing its sound absorbing function. Thus, various combinations of different panel front surface configurations with one or more perforations as described above and a masking layer will be described below.

In this aspect, the present invention relates to a sound absorbing system. The sound absorbing system may comprise a panel as described above and a masking layer. Preferably, the masking layer can be made at least to some extent breathable in such a way that the sound-absorbing function of the system is provided.

The masking layer can be attached to the panel without the possibility of detachment or with the possibility of detachment.

If the masking layer is attached to the panel in a non-removable manner, this can be done by gluing, screwing, nailing or any other permanent attachment system, preferably by gluing. The adhesive used in this application may be any adhesive known to those skilled in the art for these applications. Preferably the adhesive is transparent.

In order to ensure air permeability when the masking layer is attached to the panel by means of gluing, it is preferable to use such sticking points that, on the one hand, are sufficient for a stable permanent connection of the masking layer and the panel, and on the other hand, to ensure the sound-absorbing function of the system, leave sufficient airflow passing through the masking layer to the panel.

Non-peelable masking is preferred in panel configurations where the front face of the panel is

- the surface of the panel material,

the surface of the front outer layer of the panel, the front outer layer being preferably a cardboard layer or a non-woven material, more preferably a cardboard layer, or

the surface of a coating layer, preferably paint, the coating layer being preferably applied to the surface of the panel material or to the surface of the front outer layer of the panel.

However, non-peelable attachment of the mask layer is also possible when the front surface is the surface of the tie layer, with the acquisition layer attached to the panel material or to the front outer layer of the panel. This may be the case when, for example, the tie layer is a (thin) polymer film with dark pigments.

Next, masking will be described in more detail.

The masking layer may comprise wool, fleece, felt, polyester fleece, any other breathable material or mixtures thereof, preferably felt.

More preferably the masking layer consists of wool, fleece, felt, polyester fleece, any other breathable material or mixtures thereof, most preferably felt.

In addition, the mask layer may have a specific thickness. The thickness of the mask layer may preferably be 0.1 mm to 20 mm, preferably 1 mm to 15 mm, more preferably 2 mm to 8 mm. The thickness of the masking layer depends on the material of the masking layer, since, on the one hand, effective sound-absorbing properties must be ensured, and, on the other hand, the invisibility of the holes, and the rather dark appearance of the panel must not be visible. For example, you can use a very loose material of greater thickness than a fairly dense material. It is required that the felt, for example, 4 mm thick, has, on the one hand, sufficient air flow, and on the other hand, provides sufficient invisibility of the (rather dark) front surface.

However, any other breathable structure of the masking layer is possible.

In addition, it should be noted that the dimensions of the mask layer may be the same as the dimensions of the panel. This facilitates the installation of the sound absorbing system, since the panel and the masking layer can be installed in one step. However, they do not have to be the same as the dimensions of the panel. Larger or smaller sizes available. For example, on the one hand, a fairly small piece of masking layer may be required at a particular location on the panel, which is known to be designed to change at specific intervals. On the other hand, the lighter weight of the mask layer compared to the panel makes it possible to mask larger dimensions than the size of one panel, for example, the size of two panels, with only one mask layer, which is therefore larger than the panel.

In addition, it should be noted that if the masking layer comprises wool, fleece, felt, polyester fleece, any other breathable material, or mixtures thereof, two adjacent masking layers can be joined by felting, preferably using a special tool, such as a felting needle.

If the masking layer is releasably attached to the panel, this may be by means of a Velcro fastening system, a mushroom rod fastening system, or any other releasable fastening system, most preferably via a Velcro fastening system.

There are various fastening systems with the possibility of detachment. For example, in a Velcro fastening system, the hooks interact with the loops and provide the fastening mechanism. However, there are many forms and combinations of Velcro fastening systems, as well as self-engaging and one-piece technologies, such as, for example, a fastening system based on mushroom rods. In such a system, both sides of the fastening system contain the same geometry, in this case a mushroom rod. However, any of these systems that allow the mask layer to be releasably attached to the tie layer are included in the present invention.

Removable attachment of the mask layer is preferred in those panel configurations in which the front surface of the panel is the surface of the tie layer, the tie layer being preferably attached to the panel material or to the front outer layer of the panel.

In one preferred embodiment, the connecting layer comprises a plurality of hooks, a plurality of gripping surface features, preferably loops, or a plurality of mushroom rods, preferably a plurality of hooks, as already described above. With any of these features, it is possible to attach the mask layer to the panel in a detachable manner. Particularly preferred is, for example, a dark polymer film, i.e. a dark pigmented polymer film, which contains a plurality of hooks, a plurality of loops or a plurality of mushroom rods, preferably a plurality of hooks, such that the bonding layer can have a contrast of less than 0.3 with respect to panel perforations.

In a particularly preferred configuration, the tie layer comprises a plurality of hooks and the mask layer may comprise a plurality of loops. Thus, in this configuration, the masking layer may comprise wool, fleece, felt, polyester fleece, any other breathable material, or mixtures thereof, preferably felt, as already described above. Thus, the masking layer may comprise a plurality of loops or other similar gripping surface features (which are pieces of wool, fleece, felt, polyester fleece or any other breathable material, whereby no additional layers are required here) in such a way that between the connecting layer and the mask layer can easily establish a stable but releasable connection by attaching the mask layer to the connection layer. Another advantageous effect of this combination is that, thanks to the masking layer, neither holes nor the rather dark appearance of the panel are preferably visible.

However, other combinations are also possible.

If the connecting layer contains a plurality of grippable surface features, preferably loops, or a plurality of mushroom rods, then the masking layer may differ from that described above: the masking layer, in addition to what is described above, may contain an additional layer that is configured to connect or interact with the specified a plurality of gripping surface features, preferably loops,

or with the specified set of mushroom rods. This means that the masking layer may further comprise an additional layer containing a plurality of hooks or a plurality of mushroom rods. To provide a sound-absorbing function, this additional layer preferably contains micro-perforations. These micro-perforations can be made, for example, with a spiked roller. Preferably, this additional layer can be permanently attached to the mask layer without the possibility of detachment, more preferably glued to the mask layer, most preferably by means of sticking points.

Preferably, the flow resistance of the mask layer can be between 1 and 20,000 Pa.s/m, preferably between 100 and 1,000 Pa.s/m. The masking layer may also contain a fluorescent whitening agent.

Alternatively (or in addition) to darken the front surface of the panel, the back side of the mask layer may be darkened instead (or in addition). However, such darkening is preferably carried out in such a way that the masking layer is still breathable thereafter. Preferably, the front side of the mask layer 160 may then have a different color as required for visibility. For example, the masking layer can be made in any desired color or pattern according to the desired room wall or ceiling design, such as bright or substantially white, and still be breathable. In this particular case, the front surface (of the panels) is in fact the back surface of the masking layer.

However, the best results in terms of sound absorption and hole invisibility have been achieved with a combination of perforated gypsum board (i.e. a board with outer layers of cardboard), a bonding layer with dark pigments and hooks, and a masking layer made of felt and thus containing loops. The preferred thickness of the mask layer is approximately 4 mm.

In addition, the sound-absorbing system may include additional sound-absorbing material located behind the panel, for example, in the ceiling structure between the panel and the base plate. This additional sound-absorbing material may be mineral wool. This additional sound-absorbing material can be made in the form of a layer and/or breathable and/or perforated or micro-perforated. Additional layers of sound-absorbing material may also be part of the sound-absorbing system.

Additional advantages are that the panel according to the present invention can be mounted independently of the masking layer. However, even with a rather dark appearance, the contrast C _m between the perforations of the panel and its front surface is less than 0.3, so that these perforations are less visible to the observer. However, in a preferred embodiment in service, the mask layer may be the visible top layer of the panel of the present invention. The advantages are that the mask layer can be changed or renewed (for example, if it is dirty or damaged) or removed for washing, cleaning or modification. The mask layer can be any desired color, pattern, pattern, or photo print. The advantages associated with the surface are that, in use, the perforations required to provide effective sound damping properties are not visible (or perceptible) through the masking layer.

The system may additionally contain one or more fasteners (not shown in the drawings, but comparable to the fasteners (8) in PCT/EP2018/000581), and, preferably, using one or more fasteners, the panel is connected to an external surface (for example, a ceiling ). As a rule, the panels are more firmly attached to the wall or ceiling than the masking layer is attached to the panel.

The disadvantage of the prior art is further overcome by using a panel according to the present invention and/or according to the present invention, preferably for wall or ceiling mounting.

The benefits and benefits of the application described herein are equivalent or similar to those of the panel or system described herein.

The present invention will be further described below, while the specific embodiments do not limit the present invention in any way as described in this application.

Brief description of the drawings

Examples of the present invention are described below with reference to the drawings, in which

in fig. 1 shows a cross section of a panel (100) in accordance with the present invention;

in fig. 2 shows a cross section of a panel (100) in accordance with the present invention with outer layers;

in fig. 3 shows a cross section of a sound absorbing system (600) in accordance with the present invention;

in fig. 4 shows a cross section of a sound absorbing system (600) in accordance with the present invention with outer layers;

in fig. 5 is a cross-sectional view of a sound-absorbing system (600) in accordance with the present invention with a Velcro attachment system;

in fig. 6 shows a cross-sectional view of a sound absorbing system (600) in accordance with the present invention with outer layers and with a Velcro attachment system.

In FIG. 1 shows a cross-section of a panel (100) comprising a panel material (110), a front surface (120), and a back surface (122), the panel (100) having one or more perforations 140 that extend through the panel material (110), therefore, they can also be called through holes. The front surface (120) is made in such a way that the contrast C _m between the front surface (120) and said one or more perforations (140) is less than 0.3. This can be done with a panel material (110) or a coating layer (not shown because it will be very thin when applied to the panel material (110)) containing pigments, preferably dark pigments, more preferably dark gray pigments or black pigments. . In this example, the panel (100) is a gypsum board or insulation board. Preferably, the thickness of the panel (100) may be less than 30 mm, preferably less than 20 mm, more preferably less than 15 mm.

In FIG. 2 shows a cross section of a panel (100) comprising a panel material (110), a front outer layer (124), a rear outer layer (126) and a front surface (120), wherein the panel (100) has one or more perforations (140) that pass through the panel material (110), the front outer layer (124) and the rear outer layer (126). The front surface (120) is made in such a way that the contrast C _m between the front surface (120) and said one or more perforations (140) is less than 0.3. This can be done with a front outer layer (124) or a coating layer (not shown as it will be very thin when applied to the front outer layer (124)) containing pigments, preferably dark pigments, more preferably dark gray pigments or black pigments. In this example, panel (100) is gypsum board. Preferably, the thickness of the panel (100) may be less than 30 mm, preferably less than 20 mm, more preferably less than 15 mm.

In FIG. 3 shows a cross section of a sound absorbing system (600) in accordance with the present invention. This drawing shows the panel (100) of FIG. 1 and a mask layer (160). The masking layer (160) is non-removably attached by adhesive (not shown) to the panel material (110) or to the cover layer (not shown), preferably by means of sticking points. Here, the front surface (120) contains either the panel material (110) or a coating layer (not shown). By virtue of the masking layer (160) covering both the perforations (140) and the front surface (120), which have a contrast _Cm relative to each other of less than 0.3, the result is a system with good sound-absorbing properties, wherein for the viewer the perforations in the panel are not visible. The masking layer (160) is breathable and allows airflow, for example by containing wool or felt. The flow resistance can range from 1 to 20000 Pa*s/m. Due to the darkened front surface (120), the mask layer can be made thinner (and less opaque) with the same masking effect, resulting in improved air permeability of the mask layer and thus better sound absorption performance of the entire system. Preferably the masking layer is made of 4 mm thick felt.

In FIG. 4 shows a cross section of a sound absorbing system (600) in accordance with the present invention. This drawing shows the panel (100) of FIG. 2 and a mask layer (160). The mask layer (160) is permanently bonded by adhesive (not shown), preferably by stick points, to the front outer layer (124) or to a coating layer (not shown) that can be applied to the front outer layer (124). Here, the front surface (120) contains either the front outer layer (124) or a coating layer (not shown). By virtue of the masking layer (160) covering both the perforations (140) and the front surface (120), which have a contrast _Cm relative to each other of less than 0.3, the result is a system with good sound-absorbing properties, wherein for the viewer the perforations in the panel are not visible. The masking layer (160) is breathable and allows airflow, for example by containing wool or felt. The flow resistance can be from 1 to 20000 Pa*s/m. Due to the darkened front surface (120), the mask layer can be made thinner (and less opaque) with the same masking effect, resulting in improved air permeability of the mask layer and thus better sound absorption performance of the entire system. Preferably, the masking layer is made of 4 mm thick felt.

In FIG. 5 shows a cross-sectional view of a sound absorbing system (600) in accordance with the present invention with a Velcro attachment system. This drawing shows the panel (100) of FIG. 1 with a tie layer (165) and a mask layer (160). The connecting layer (165) is a polymer film with many hooks (10). The bonding layer (165) is attached without the possibility of detachment by gluing (not shown) to the material (110) of the panel, preferably by means of sticking points. In addition, the bonding layer (165) contains perforations (essentially) in the same locations where the panel contains its perforations (140). The masking layer (160) may be made of wool, fleece, felt, polyester fleece, any other breathable material, or mixtures thereof. As mentioned above, these materials already contain a plurality of grippable surface features, preferably loops (12), which are shown larger in this drawing for clarity (which also applies to hooks (10)) compared to the rest of the features. Here the connecting layer (165) contains the front surface (120). By virtue of the masking layer (160) covering both the perforations (140) and the bonding layer (165), which have a contrast _Cm relative to each other of less than 0.3, the result is a system with good sound-absorbing properties, wherein the perforations are in the panel are not visible. The masking layer (160) is breathable and allows airflow, for example by containing wool or felt. The flow resistance can range from 1 to 20000 Pa*s/m. Due to the darkened front surface (120), the mask layer can be made thinner (and less opaque) with the same masking effect, resulting in improved air permeability of the mask layer and thus better sound absorption performance of the entire system. Preferably the masking layer is made of 4 mm thick felt.

The Velcro fastening system is further described herein and in priority application PCT/EP2018/000581, alternatively or in addition to the use of adhesive, for example by means of sticky points. In said priority application, the panel (2) may be identical to the panel (100), the receiving surface (4) may be identical to the front surface (120), preferably when the front surface (120) is the surface of the bonding layer (165), and the detachable layer (6) may be identical to the masking layer (160), the hooks (10) may be identical to the hooks (10), and the gripping surface elements (12) may be identical to the gripping surface elements (12).

The masking layer (160) should be held well enough on the panel (100) so as not to fall off. However, it is preferred that the masking layer (160) is not retained more strongly than to the extent that the masking layer (160) can be removed without tearing it and/or the panel from its connection to the wall or ceiling and/or without requiring too much force. for manual operations.

By connecting with complementary hooks and gripping surface features or a Velcro system, the masking layer (160) is attached in such a way that it can be easily removed, which makes the system more flexible. This means that said layer can be removed or replaced for repair, and can also be replaced or modified according to the user's preferences. The connection by means of hooks and gripping surface elements can preferably be in the form of a Velcro fastener.

In FIG. 6 shows a cross-sectional view of a sound absorbing system (600) in accordance with the present invention with a Velcro attachment system. This drawing shows the panel (100) of FIG. 2 with a bonding layer (165) and a masking layer (160). The connecting layer (165) is a polymer film with many hooks (10). The tie layer (165) is non-releasably attached by adhesive (not shown) to the front outer layer (124), preferably with stick points. In addition, the bonding layer (165) contains perforations (essentially) in the same locations where the panel contains its perforations (140). The masking layer (160) may be made of wool, fleece, felt, polyester fleece, any other breathable material, or mixtures thereof. As mentioned above, these materials already contain a plurality of grippable surface features, preferably loops (12), which are shown larger in this drawing for clarity (which also applies to hooks (10)) compared to the rest of the features. Here the connecting layer (165) contains the front surface (120). By virtue of the masking layer (160) covering both the perforations (140) and the bonding layer (165), which have a contrast _Cm relative to each other of less than 0.3, the result is a system with good sound-absorbing properties, wherein the perforations are in the panel are not visible. The masking layer (160) is breathable and allows airflow, for example by containing wool or felt. The flow resistance can range from 1 to 20000 Pa*s/m. Due to the darkened front surface (120), the mask layer can be made thinner (and less opaque) with the same masking effect, resulting in improved air permeability of the mask layer and thus better sound absorption performance of the entire system. Preferably the masking layer is made of 4 mm thick felt.

Another variant (not shown) in Fig. 5 and 6 may be to swap the hooks and loops in the Velcro fastening system. The mask layer then contains an additional layer with many hooks. To ensure breathability, this additional layer preferably contains micro-perforations. By virtue of the masking layer (160) covering both the perforations (140) and the bonding layer (165), which have a contrast _Cm relative to each other of less than 0.3, the result is a system with good sound-absorbing properties, wherein the perforations are in the panel are not visible. The masking layer (160) is breathable and allows airflow, for example by containing wool or felt. The flow resistance can range from 1 to 20000 Pa*s/m.

List of reference designations

10 hooks

12 loops / gripping surface elements

100 panel

110 panel material

120 front face

122 back surface

124 front outer layer

126 back outer layer

140 perforated/through hole

160 masking layer

165 connecting layer

Claims (20)

1. Panel (100) with one or more perforations (140), containing a front surface (120), in which the contrast C _m between the front surface (120) and said one or more perforations (140) is less than 0.3. 2. Panel (100) according to claim 1, wherein the contrast _Cm between the front surface (120) and said one or more perforations (140) is less than 0.2, or less than 0.1, or less than 0.05. 3. Panel (100) according to claim 1 or 2, in which the panel (100) contains the material (110) of the panel, and the material (110) of the panel contains gypsum, fiberglass, mineral wool or fiber-gypsum mixture, and / or panel (100) is a gypsum board, gypsum board or insulation board, and/or the thickness of the panel (100) is less than 30 mm, or less than 20 mm, or less than 15 mm. 4. The panel (100) according to any one of the preceding claims, wherein the front surface (120) of the panel (100) is surface of the material (110) of the panel, the surface of the front outer layer (124) of the panel (100), wherein the front outer layer (124) is a layer of cardboard or a non-woven material, the surface of a coating or paint layer, wherein the coating or paint layer is applied to the surface of the material (110) of the panel or to the surface of the front outer layer (124) of the panel (100), or the surface of the connecting layer (165), wherein the connecting layer (165) is attached to the material (110) of the panel or to the front outer layer (124) of the panel (100). 5. Panel (100) according to claim 4, in which the material (110) of the panel, the front outer layer (124), the coating layer and / or the connecting layer (165) contain pigments, or dark pigments, or dark gray pigments, or black pigments. 6. Panel (100) according to any one of paragraphs. 4 or 5, in which the connecting layer (165) contains plastic or is a polymer foil or a film or a polymer film. 7. Panel (100) according to any one of paragraphs. 4-6, in which the connecting layer (165) contains one or more perforations (140) in the same locations as the panel (100), or contains a plurality of micro-perforations. 8. Panel (100) according to any one of paragraphs. 4-7, in which the connecting layer (165) contains a plurality of hooks, a plurality of gripping surface features, a plurality of loops, or a plurality of mushroom rods. 9. Sound-absorbing system (600) comprising a panel (100) according to claim 1 and a masking layer (160), wherein the masking layer (160) is breathable. 10. Sound-absorbing system (600) according to claim 9, wherein the masking layer is attached to the panel (100) without the possibility of detachment by gluing, screwing, nailing or a permanent attachment system, or with the possibility of detachment by means of a Velcro fastening system, fastening systems based on mushroom rods or fastening systems with the possibility of detachment. 11. Sound-absorbing system (600) according to claim 9 or 10, wherein the masking layer (160) comprises wool, fleece, felt, polyester fleece, or a breathable material, or mixtures thereof. 12. Sound-absorbing system (600) according to any one of paragraphs. 9-11, in which the flow resistance of the mask layer (160) is from 1 to 20000 Pa*s/m or from 100 to 1000 Pa*s/m. 13. Sound-absorbing system (600) according to any one of paragraphs. 9-12, additionally containing one or more fasteners (8), and the panel (100) is connected to the outer surface using the specified one or more fasteners (8). 14. The use of the panel (100) according to any one of paragraphs. 1-8 or sound-absorbing system (600) according to any one of paragraphs. 9-13 for wall or ceiling mounting.

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