Acoustic panel

Abstract

The invention relates to an acoustic panel comprising at least one wall element having a thickness of between 0.7 and 4 cm and comprising at least one slot having a height H of between 0.5 and 2 cm, more particularly between 0.6 and 1.75 cm, more particularly between 0.6 and 1.5 cm, into which a series of objects is introduced, each having a width and a length greater than the width, as well as a concavity oriented downwards when the wall element is positioned in such a way that its thickness is horizontal, the panel having a weighted acoustic absorption capacity, measured according to standard ISO-11654: 1997, of between 0.65 and 0.75.

Description

[0001] ACOUSTIC PANEL

[0002] The present invention relates to an acoustic panel, its use and its manufacturing process.

[0003] Acoustic panels play a crucial role in noise management and improving sound quality in various environments, from offices and conference rooms to recording studios and public spaces. They not only reduce noise but also improve speech intelligibility and listening quality.

[0004] Indeed, noise is a major problem in many environments today, particularly in open-plan offices, schools, and hospitals. Acoustic panels are essential for absorbing sound, reducing echoes, and lowering ambient noise levels to create a more comfortable environment conducive to concentration and productivity.

[0005] Outdoors, noise and sound pollution are also increasingly present and also affect the comfort of citizens, spectators of daily life or spectators at any events.

[0006] In indoor spaces such as classrooms, auditoriums, and meeting rooms, speech intelligibility is paramount. Acoustic panels help control reverberation and improve speech clarity, which is essential for effective communication.

[0007] Acoustic comfort is also an important factor in the well-being of a space's occupants. A poor acoustic environment can lead to stress, fatigue, and decreased cognitive performance. Acoustic panels help create a balanced sound environment, thus reducing the negative effects of noise.

[0008] The state of the art for standard acoustic panels has evolved considerably to meet the growing needs for acoustic management in various environments.

[0009] Acoustic panels made with mineral fibers such as rock wool and glass wool are currently available and widely used due to their excellent sound absorption and fire resistance properties. These materials are often chosen for panels installed in industrial and commercial environments. Acoustic panels made with natural fibers and materials such as recycled cotton, hemp, and cellulose are also available. These are increasingly used for eco-friendly acoustic solutions. These materials offer good sound absorption while being environmentally responsible.

[0010] Acoustic panels using acoustic foams such as polyurethane and melamine foams are also available, popular for their lightness and ability to absorb high-frequency sounds. These are commonly used in recording studios and offices.

[0011] We also encounter panels using composite materials combining different fibers and resins, which thus offer improved acoustic properties and increased durability.

[0012] Acoustic panels come in various types. For example, there are sound-absorbing acoustic panels designed to reduce reverberation and echoes by absorbing sound waves. These are often installed on walls and ceilings.

[0013] There are also diffusing acoustic panels used to disperse sound waves, creating a more even distribution of sound in a room. These are typically used in concert halls and auditoriums. Finally, there are hybrid acoustic panels that combine absorbent and diffusive properties. These are particularly useful in multifunctional environments.

[0014] More recently, various developments have been made with the aim of enhancing acoustic panel technology. For example, adaptive acoustic panels are now available, incorporating phase-change materials or mechanical mechanisms to dynamically adjust acoustic properties according to the specific needs of the environment.

[0015] We also encounter 3D printed panels which allow for the creation of complex shapes to absorb or diffuse sound, as well as acoustic panels which use nanostructures to improve absorption properties with reduced weight and thickness.

[0016] As can be seen, the technical field of acoustic panels is evolving, but apart from acoustic panels made from natural fibers, the ecological dimension of many of the solutions described above remains neglected. In fact, several of these solutions use polymers, adhesives and resins, synthetic materials that emit volatile organic compounds and are very difficult to recycle given their highly varied composition and multi-material nature.

[0017] The present invention aims to provide an acoustic panel that is environmentally friendly and durable while exhibiting significant acoustic absorption efficiency.

[0018] The present invention thus relates to an acoustic panel comprising at least one wall element of a thickness between 0.7 and 4 cm and comprising at least one slot of a height H between 0.5 and 2 cm, more particularly between 0.6 and 1.75 cm, more particularly between 0.6 and 1.5 cm, into which is introduced a series of objects each having a width and a length greater than the width, as well as a concavity oriented downwards when said wall element is positioned so that its thickness is horizontal, preferably, said panel having a weighted sound absorption index, measured according to ISO-1 1654:1997, between 0.65 and 0.75.

[0019] As can be seen, the acoustic panel according to the present invention has a wall element with a thickness of between 0.7 and 4 cm, preferably between 0.9 and 2.5 cm, more particularly between 1 and 2 cm. It has a series of slots in which objects with a downward concavity are placed, creating on the other side a series of ridges which have good sound wave absorption capacity, provided that the weighted sound absorption index, measured according to ISO-1 1654:1997, is between 0.65 and 0.75.

[0020] The weighted sound absorption index is a single frequency-independent value, equal to the value of the reference curve at 500 Hz after translation, as specified in International Standard ISO-1 1654:1997.

[0021] The fact that concave objects are simply inserted into a slot creates a simple assembly that avoids the use of glues, which typically emit volatile organic compounds. It also allows for vibration absorption, as the concave objects are simply inserted into the slot, which slightly constrains them, allowing them to move slightly without falling. This is due to the slot height, specifically chosen within the range of 0.5 to 2 cm, particularly between 0.6 and 1.75 cm, and especially between 0.6 and 1.5 cm, and to the fact that the object has a downward concavity. Indeed, an object with a downward concavity has an internal curved shape (and possibly also a convex external shape), which allows the object to be slightly clamped within the slot.

[0022] Advantageously, in one embodiment, the acoustic panel according to the present invention comprises at least one object, preferably each object of said series of objects, which has a contour of which at least a part is curved.

[0023] More particularly, in one embodiment according to the present invention, the acoustic panel comprises at least one object, preferably each object of said series of objects has a median width less than a width taken near the ends.

[0024] This allows, when objects are placed side-by-side in a slot and thus juxtaposed, for the middle section to be narrower. Therefore, the portion inserted into the slot is actually narrower than the protruding sections near the ends. Thus, a gap is created between two objects in the same slot, and the sections near the ends of the objects are very close to each other, even overlapping, while simultaneously capturing a volume of air beneath the objects. This improves the sound absorption capabilities of the panel according to the present invention.

[0025] In a particular embodiment according to the present invention, at least one object, preferably each object of said series of objects, has an edge made of a flexible material, preferably rubber or silicone, which allows adhesion to the bottom wall of the slot of the object while bringing an elastic material into the acoustic panel according to the present invention.

[0026] In yet another particular embodiment according to the present invention, the acoustic panel has at least one object, preferably each object of said series of objects, which has a body made of fibrous material, for example composed of wool fibers, cotton and synthetic fibers, more particularly of felt made of wool fibers, cotton and synthetic fibers, materials also having sound absorption capabilities.

[0027] In a preferred embodiment of the acoustic panel according to the present invention, at least one object, preferably each object in said series of objects, is half a tennis (or padel) ball, cut along the outer surface seam of the tennis (or padel) ball. This allows for the recycling of discarded tennis (or padel) balls in a sector where the amount of waste is very high. Indeed, tennis ball waste constitutes an urgent environmental problem, with only 1% of the more than 400 million balls manufactured each year being recycled. Today, the balls end up in landfills, causing congestion and contributing to resource depletion.

[0028] Recycling efforts are limited due to the complex materials used in tennis (or padel) balls. The production and disposal of tennis balls consume significant resources and contribute to greenhouse gas emissions. Despite some initiatives, sustainable practices in the tennis industry are not widely adopted. The panel according to the present invention gives tennis (or padel) balls a second life by repurposing them to meet current needs in a world where noise pollution is constantly increasing.

[0029] Ideally, the objects to be inserted are halves of tennis or padel balls. This allows for a sufficiently durable insertion without the need for glue. When desired, the balls are easily removed from the support and replaced with others, allowing for variations in patterns and colors.

[0030] In the context of the present invention, the word "ball" or "tennis ball" advantageously refers to tennis balls and any similar ball, such as padel balls (type of material, and arrangement in two connected half-balls).

[0031] Indeed, used tennis or padel balls have an outer coating that can be colored to make the acoustic panel attractive to the eye and compatible with natural or synthetic dyes, preferably environmentally friendly, non-toxic and non-corrosive.

[0032] One method for dyeing tennis balls could be, for example, immersing the cut balls in a hot water solution at a temperature between 80 and 90°C, using a dye suitable for materials containing nylon. The immersion time influences the final color; 10 minutes produces a more intense color. The final color also depends on the balls' original shade, which is related to their composition (felt / nylon ratio) and their wear. The balls are then air-dried.

[0033] This is advantageously achieved using industrial-type washing machines, in which the tennis ball halves to be dyed are placed, and the dye (including a mixture of different yellow / red / blue dyes, see below, in the specified concentrations) is added in concentrated form to the pre-wash compartment, along with detergent and / or fabric softener. Temperature and (quick) cycle control are advantageously managed via the built-in or configurable system. If an acidic dye (see below) or one that is potentially corrosive at high temperatures or high concentrations is to be used, an industrial washing machine, preferably one constructed with compatible materials, is necessary.

[0034] In other words, preferably, the manufacturing process according to the invention will include the step of coloring the half-balls or balls in which the balls or half-balls are brought into contact with an aqueous solution at a temperature above 60°C, preferably a temperature of at least 80°C, for example between 80°C and 90°C or, preferably, at a temperature of at least 90°C, or even close to 100°C, preferably for a period of between 1 and 20 minutes, preferably between 2 and 15 minutes, for example about 10 minutes.

[0035] Advantageously, the coloring is carried out from a mixture of (water-soluble) dyes chosen from blue dye, red dye, yellow dye and black dye, said mixture of dyes being made in proportions suitable for giving the desired final color.

[0036] This mixture is advantageously first designed in silico, preferably on the basis of (i) the residual colouring of the balls and (ii) the shade that the mixture of blue, yellow, red and black colours will provide and (iii) the duration of contact.

[0037] Thus, an advantageous preliminary step of the present process consists of sorting the bales according to their residual color and distributing them into at least five classes: substantially white bales; bales with a main color of yellow and of low intensity; bales with a color of yellow and of high intensity; bales with a color other than yellow and of low intensity; bales with a color other than yellow and of high intensity.

[0038] In the context of the present invention, "low intensity" preferably means residual coloration that is negligible compared to the coloration that will be imparted after 5 minutes of impregnation (for example, the relative intensity of the yellow component of the dye is not modified by more than 10%, either increasing or decreasing, and / or the residual coloration is no longer visible after 5 minutes of application of the coloring composition: the yellow / red / blue distribution of the coloring solution compared to the yellow / red / blue distribution of the colored half-ball). Conversely, in the context of the present invention, "high intensity" preferably means residual coloration that remains visible even after coloring, which will be applied after 5 minutes, and / or in which the relative intensity of the yellow component of the dye is modified by more than 10%.Alternatively, the mixture of blue, yellow, red and black colors in the coloring composition is designed in silico, based solely on the desired shade, and the duration of contact of the half-balls with the coloring solution is modulated according to their residual coloring before contact, or modulated according to the coloring obtained over time.

[0039] In this coloring step, preferably the blue dye is CAS 3351-05-01 or CAS 67827-60-5, and / or the red dye is CAS 71873-39-7, and / or the yellow dye is CAS-70865-20-2 and / or the black dye is CAS 57693-14-8, with optionally also CAS 3351-05-01 (blue) and / or CAS 68959-00-2.

[0040] These are intense, low-toxicity dyes, all with acidic properties, which allows them to be mixed in water to form baths with the desired colors.

[0041] The balls or half-balls thus colored are dried, preferably via a flow of dry air at room temperature.

[0042] In the context of the present invention, preferably it is the half-balls that are colored: although the coloring will impregnate both sides, the half-balls occupy less space and have a higher density, which is advantageous for coloring via a washing machine.

[0043] Preferably, according to the present invention, a plurality of objects is inserted into each slot, which facilitates construction. In a variant, a single object is inserted into each slot, the panel comprising a plurality of slots, which allows the position of each object within the acoustic panel to be defined in advance.

[0044] More specifically, when said panel is positioned vertically, said series of objects comprises at least 4 sub-series of objects arranged vertically so as to form columns of objects and rows of objects.

[0045] Preferably, the objects in said rows are aligned vertically between two consecutive rows or offset vertically between two consecutive rows.

[0046] Alternatively, the objects in said columns are aligned horizontally between two consecutive columns or offset horizontally between two consecutive columns.

[0047] In a preferred embodiment of the present invention, said wall element comprises a plurality of wall blocks, each wall block having two ends each provided with tenons, said acoustic panel further comprising two lateral pillars each provided with a mortise so as to form a multiple tenon-mortise assembly of said two lateral pillars and of said plurality of wall blocks, which allows a simple assembly, without requiring synthetic glue and is part of the durable and ecological character of the acoustic panel according to the present invention.

[0048] More specifically, said wall element comprises n wall blocks, each wall block having two ends each equipped with tenons, said acoustic panel further comprising at least two lateral pillars equipped with n mortises so as to form a tenon mortise assembly of said two lateral pillars and said n wall blocks.

[0049] Advantageously each mortise is spaced from another mortise by a distance equal to the height H of said slot.

[0050] In one embodiment of the present invention, said slot extends between a sky wall and a bottom wall, said sky wall and said bottom wall being flat walls and in which said object rests the bottom wall by two lateral edges of a central part, in such a way that two sides of the object, extending from the central part, protrude on either side of said wall element.

[0051] In a variant of the present invention, said slot extends between a sky wall and a bottom wall, said sky wall and said bottom wall being corrugated walls each having a corrugation formed of x crests and y troughs, the corrugation of the sky wall being substantially parallel to the corrugation of the bottom wall.

[0052] More particularly, according to the present invention, each ridge of the sky wall of a slot houses an object and in which said object rests on a ridge of the bottom wall, preferably via a central part, in such a way that two flanks of the object, extending from the central part, protrude on either side of said wall element.

[0053] According to an advantageous embodiment, the panel and slot system is a checkerboard formed by a two-dimensional network of meshes, this checkerboard being deformable and the meshes forming a plurality of holes of dimensions compatible with the insertion of half a tennis ball (per hole or, preferably, half a ball every two holes, depending on their sizes). Preferably, the wires forming these meshes of this checkerboard have a diameter between 1 and 7 mm, preferably between 2 and 6 mm, preferably between 3 and 5 mm.

[0054] Indeed, a minimum thickness ensures good mechanical resistance, whereas a thickness that is too generous could not be masked by the half-balls.

[0055] Preferably the threads forming these meshes are made of a material chosen from among metal and polymers.

[0056] When the wires forming the mesh are made of metal, preferably iron is the predominant element (atom).

[0057] Polymers with mechanical strength properties compatible with the use of the panel are highly preferred.

[0058] Preferably: artificial polymers chosen from polyethylene (recycled), polypropylene (recycled), polyethylene terephthalate (PET), preferably recycled PET, nylon and / or recycled tennis racket strings;

[0059] Artificial (recycled) textile fibers;

[0060] Natural textile fibres (recycled or not, preferably chosen from hemp, linen and cotton).

[0061] Preferably, the openings of these metal meshes have a height between 0.5 and 2.5 cm (preferably between 0.8 and 2.2 cm, or even between 1 and 22 cm) and a width between 4 and 5.5 cm.

[0062] A rectangular shape is advantageous.

[0063] According to a preferred option, the orifices have a hexagonal shape, the hexagons preferably being irregular hexagons 51 or 71, preferably having a maximum height between 10 and 22 mm and / or a maximum length between 40 and 50 mm.

[0064] According to an alternative to this preferred option, the irregular hexagons have two long sides 52 parallel and of equal length and four short sides 53 of equal length, parallel in pairs, each short side 53 being connected at each end to a long side 52 and, at its other end, to another short side 53 (preferably forming a substantially right angle 54), while remaining compatible with the formation of a continuous checkerboard. For example, the length of these long sides of these hexagons is between 15 and 25 mm; advantageously, the height of these hexagons is between 15 and 22 mm. This advantageously implies a total length of the irregular hexagon (measured from one junction of the short sides 53 to the opposite junction of the short sides 53) 51 of between 40 and 50 mm (preferably between 42 and 46 mm) and that each short side 53 has a length of about 70% of the length of the long side 52, here preferably between about 10 and 17 mm.

[0065] According to the other branch of the alternative, the irregular hexagons have four long sides 72 parallel in pairs and of the same size, and two short sides 73 of the same size, parallel, each long side 72 being connected to a short side 73 and, at its other end, to another long side 72, while remaining compatible with the formation of a continuous checkerboard. For example, advantageously, the height of these hexagons is between 15 and 22 mm. Preferably, the length of the hexagon 71 is between 40 and 50 mm (preferably between 42 and 46 mm).

[0066] In the context of the present invention, variations of irregular rectangles or hexagons are possible provided that the dimensions (height, width) remain compatible with the arrangement of half a tennis or padel ball. However, it is preferable to avoid a checkerboard pattern or checkerboard sections with too much material; therefore, geometric patterns allowing for a substantially seamless overlap (without gaps that could potentially be filled) are preferred.

[0067] A checkerboard pattern whose sequence of motifs is in the form of irregular rectangles or hexagons, but in which part of the opening is filled (with metal, polymer; advantageously the same material as the threads forming the mesh), will be considered, in the context of the present invention, as an irregular rectangle or hexagon. In this approach, the checkerboard would reveal openings of rectangular shape (for example, with internal rounding on at least one or two sides), trapezoidal shape (also from partially filled rectangles), or even in the form of an irregular pentagon in which two adjacent sides of the irregular hexagon forming the motif would be further connected by a solid triangular structure.

[0068] Advantageously, tennis balls inserted into the mesh (preferably hexagonal, preferably a 61-square checkerboard of 51 irregular hexagons, or a 70-square checkerboard of 71 irregular hexagons) are held in place by the compressive forces that the balls exert on the structure. Advantageously, the balls are inserted every two, three, or four meshes, so as to have homogeneous and complete coverage of the checkerboard.

[0069] Preferably, the spacing between the balls is small enough so that the mesh structure is hidden or substantially hidden.

[0070] This structure is easy to design and its deformable appearance allows for easy application and / or provides an aesthetic effect.

[0071] Advantageously, according to the present invention, the acoustic panel or the checkerboard of hexagons comprises between 200 and 300, or even 350, objects per square meter. 2, more specifically between 250 and 290 objects / m 2 .

[0072] Preferably, according to the present invention, the acoustic panel has a sound absorption coefficient at 2000 Hz, measured according to ISO-354:2003, of between 0.9 and 0.99.

[0073] Advantageously, according to the present invention, the acoustic panel has a sound absorption coefficient at 1600 Hz, measured according to ISO-354:2003, of between 0.75 and 0.9.

[0074] Preferably, according to the present invention, the acoustic panel has a sound absorption coefficient at 500 Hz, measured according to ISO-354:2003, of between 0.75 and 0.9.

[0075] The acoustic coefficient is preferably determined from reverberation time measurements measured according to ISO-354:2003.

[0076] Other embodiments of the acoustic panel according to the invention are indicated in the attached claims.

[0077] The present invention also relates to the use of an acoustic panel according to the invention in furniture, such as a chair, a bench, a table, a partition panel, a painting, or a chaise longue. Other uses of the acoustic panel according to the invention are indicated in the appended claims.

[0078] The present invention also relates to a method for manufacturing an acoustic panel, the invention comprising:

[0079] A tennis ball cut according to the flexible joints between the textile parts,

[0080] A preparation of a structure comprising at least one wall element of a thickness between 0.7 and 3 cm and comprising at least one slot of a height H between 0.5 and 2 cm, more particularly between 0.6 and 1.75 cm, more particularly between 0.6 and 1.5 cm. An insertion of the cut tennis balls into said slots.

[0081] More specifically, said preparation of the structure includes an assembly of n wall blocks, each wall block having two ends each fitted with tenons and at least two lateral pillars, with each tenon fitting into each mortise.

[0082] Other features, details and advantages of the invention will become apparent from the description given below, by way of non-limitation and with reference to the drawings.

[0083] In the drawings, Figures 1a to 1d represent the assembly of an acoustic panel according to the present invention.

[0084] Figure 2 represents an application of an acoustic panel according to the present invention, in which the tenon-mortise assembly of the panel elements is carried out.

[0085] Figure 3 illustrates other uses of the acoustic panel according to the present invention.

[0086] Figure 4 Evolution of the acoustic absorption coefficient of the acoustic panel as a function of frequency.

[0087] Figure 5 Irregular hexagon constituting a mesh.

[0088] Figure 6 Mesh formed of irregular hexagons.

[0089] Figure 7 Alternative mesh formed of irregular hexagons.

[0090] In the figures, identical or similar elements bear the same reference numbers.

[0091] As can be seen in Figure 1, to manufacture an acoustic panel according to the present invention, tennis balls 1 are cut (see Figure 1b) along the flexible joints 2 between the textile parts 3 forming the body in fibrous material, for example composed of wool fibers, cotton and synthetic fibers, more particularly in felt of wool fibers, cotton and synthetic fibers.

[0092] A structure 4 is prepared (see figure aa). This includes a wall element 5 with a thickness e between 0.7 and 3 cm.

[0093] The wall element comprises, in the embodiment shown, a series of slots 6, each of which has a height H between 0.5 and 2 cm, more particularly between 0.6 and 1.75 cm, more particularly between 0.6 and 1.5 cm.

[0094] Next, the cut tennis balls 1 are inserted into said slots 6.

[0095] As can be seen in Figures 1b and 1d, the cut tennis balls each have a median width I and a length L greater than the width, as well as a downward-facing concavity C when the wall element is positioned so that its thickness is horizontal (as illustrated in Figure 1d). The contour of each tennis ball is curved, and the median width is less than a width 11 taken near the ends.

[0096] The resulting acoustic panel has a weighted sound absorption coefficient, measured according to ISO 11654:1997, of between 0.65 and 0.75. It contains more than 200 tennis balls per square meter. 2 .

[0097] Figure 2 shows a variant according to the present invention, made from the same tennis balls as in Figure 1. However, as can be seen in Figure 2, the wall element 5 comprises n wall blocks 8, each wall block 8 having two ends, each equipped with tenons 9. The acoustic panel 4 also comprises two lateral pillars 7, each equipped with n mortises 10 so as to form a tenon-mortise assembly of said two lateral pillars 7 and the n wall blocks 8. Each mortise is spaced from another mortise by a distance equal to the height H of said slot.

[0098] Each slot extends between a sky wall 12 and a bottom wall 11. The sky wall 12 and said bottom wall 11 are corrugated walls each having an undulation formed of x crests and y troughs, the undulation of the sky wall being substantially parallel to the undulation of the bottom wall.

[0099] As can be seen, once assembled, each ridge of the sky wall 12 of a slot 6 houses an object (half a tennis ball 1) which therefore rests on a ridge of the bottom wall 11, preferably via a central part, in such a way that two sides of the object, extending from the central part, protrude on either side of said wall element.

[0100] As can be seen in Figure 3, the acoustic panel according to the invention can be used in furniture, such as a bench (Figure 3a), a partition panel (Figure 3c) or a chaise longue (Figure 3b).

[0101] Example: Determination of the sound absorption factor based on standard 180-354-2003 and ISO 1 1654-1997.

[0102] Characteristics of the reverberation room:

[0103] The reverberation chamber is shaped like an irregular heptahedron. Its volume is 197 m³. 3The total surface area of ​​the walls, floor and ceiling is 208.8 m². 2 and the floor area is 52 m 2 .

[0104] Five curved diffuser panels were suspended in the room: 5 x (2.01 m x 1.23 m). The average reverberation times, for calculating the absorption factors, were determined as follows:

[0105] Nature of the noise: scanning (duration 23.8s);

[0106] Analysis by 1 / 3 of an octave;

[0107] Number of speakers: 1;

[0108] Number of microphone positions: 6;

[0109] Number of speaker positions: 3;

[0110] The acoustic panels consist of tennis balls attached to a wooden wall element. The base of the wooden wall element is 2 cm thick, with a 6 cm thick perimeter frame. The wooden wall element is perforated with rounded holes to hold the tennis balls. The entire panel is made up of 8 interlocking panels that fit together using a tongue and groove system to form a total surface area of ​​11.7 m². 2 .

[0111] The measurement conditions are an ambient temperature of 20.8°C and a relative humidity of 60%.

[0112] Table 1 Reverberation Time Measurement

[0113] Ti: Average reverberation time of the empty room

[0114] Table 2 Measurement of the sound absorption coefficient as Determination of the weighted sound absorption index according to the ISO standard-

[0115] 1 1654-1997 : aw = 0.70(LM).

[0116] Figure 4 shows the acoustic properties as a function of the frequency of the emitted sound.

[0117] Metallic checkerboard

[0118] Figures 5, 6, and 7 show a metal support formed of irregular hexagons, allowing for the arrangement of tennis ball halves according to the invention; the tennis ball halves are schematically represented in Figure 7. The tennis ball halves are easily inserted and remain in place even without the use of glues or other fasteners. The tennis ball halves can be removed, if necessary, for example, to change the appearance. It is understood that the present invention is in no way limited to the embodiments described above and that many modifications can be made to them without departing from the scope of the appended claims.

Claims

DEMANDS 1. Acoustic panel comprising at least one wall element with a thickness between 0.7 and 4 cm and comprising at least one slot with a height H between 0.5 and 2 cm, more particularly between 0.6 and 1.75 cm, more particularly between 0.6 and 1.5 cm, into which is inserted a series of objects each having a width and a length greater than the width, as well as a concavity oriented downwards when said wall element is positioned so that its thickness is horizontal, said panel having a weighted sound absorption index, measured according to ISO-1 1654:1997, between 0.65 and 0.

75.

2. Acoustic panel according to claim 1, wherein at least one object, preferably each object of said series of objects, has a contour of which at least a part is curved.

3. Acoustic panel according to claim 1 or 2, wherein at least one object, preferably each object of said series of objects, has a median width less than a width taken near the ends.

4. Acoustic panel according to any one of claims 1 to 3, wherein at least one object, preferably each object of said series of objects, has an edge of flexible material, preferably of rubber or silicone.

5. Acoustic panel according to any one of claims 1 to 4, wherein at least one object, preferably each object of said series of objects, has a body made of fibrous material, for example composed of wool fibers, cotton and synthetic fibers, more particularly of felt made of wool fibers, cotton and synthetic fibers.

6. Acoustic panel according to any one of claims 1 to 5, wherein at least one object, preferably each object of said series of objects, is a half tennis ball, cut along the external surface seam of the tennis ball.

7. Acoustic panel according to any one of claims 1 to 6, in which a plurality of objects is introduced into each slot.

8. Acoustic panel according to any one of claims 1 to 6, wherein a single object is introduced into each slot, said panel comprising a plurality of slots.

9. Acoustic panel according to any one of claims 1 to 8, wherein, when said panel is positioned vertically, said series of objects comprises or less 4 sub-series of objects arranged vertically to form columns of objects and rows of objects.

10. Acoustic panel according to claim 9, wherein the objects of said rows are aligned vertically between two consecutive rows or offset vertically between two consecutive rows. 1 1. Acoustic panel according to claim 9 or claim 10, wherein the objects of said columns are aligned horizontally between two consecutive columns or offset horizontally between two consecutive columns.

12. Acoustic panel according to any one of the preceding claims, wherein said wall element comprises a plurality of wall blocks, each wall block having two ends each provided with tenons, said acoustic panel further comprising two lateral pillars each provided with a mortise so as to form a multi-tenon-mortise assembly of said two lateral pillars and of said plurality of wall blocks.

13. Acoustic panel according to any one of claims 1 to 11, wherein said wall element comprises n wall blocks, each wall block having two ends each provided with tenons, said acoustic panel further comprising at least two lateral pillars provided with n mortises so as to form a mortise and tenon joint of said two lateral pillars and said n wall blocks.

14. Acoustic panel according to claim 13, in which each mortise is spaced from another mortise by a distance equal to the height H of said slot.

15. Acoustic panel according to any one of the preceding claims, wherein said slot extends between a sky wall and a back wall, said sky wall and said back wall being flat walls and wherein said object rests the back wall by two lateral edges of a central part, in such a way that two sides of the object, extending from the central part, protrude on either side of said wall element.

16. Acoustic panel according to any one of claims 1 to 14, wherein said slot extends between a sky wall and a back wall, said sky wall and said back wall being corrugated walls each having a corrugation formed of x crests and y troughs, the corrugation of the sky wall being substantially parallel to the corrugation of the back wall. 18 17. Acoustic panel according to claim 16, in which each ridge of the sky wall of a slot houses an object and in which said object rests on a ridge of the bottom wall, preferably via a central part, in such a way that two flanks of the object, extending from the central part, protrude on either side of said wall element.

18. Acoustic panel according to any one of the preceding claims 1 to 6 being a checkerboard (61, 70) formed of a two-dimensional network of meshes, said checkerboard being deformable and said meshes forming a plurality of orifices having a height between 5 and 22 mm and a width between 40 and 55 mm, the wires forming said meshes having a diameter between 0.4 and 1 cm.

19. The acoustic panel of claim 18, wherein the checkerboard (61, 70) is made up of a plurality of irregular hexagons (51, 71).

20. Acoustic panel according to any one of the preceding claims, comprising a number of objects between 200 and 300 objects / m² 2 , more specifically between 250 and 290 objects / m 2 .

21. Acoustic panel according to any one of the preceding claims, having a sound absorption coefficient at 2000 Hz, measured according to ISO-354:2003, of between 0.9 and 0.

99.

22. Acoustic panel according to any one of the preceding claims, having a sound absorption coefficient at 1600 Hz, measured according to ISO-354:2003, of between 0.75 and 0.

9.

23. Acoustic panel according to any one of the preceding claims, having a sound absorption coefficient at 500 Hz, measured according to ISO-354:2003, of between 0.75 and 0.

9.

24. Use of an acoustic panel according to any one of the preceding claims, in furniture, such as for example a chair, a bench, a table, a partition panel, a painting, a chaise longue.

25. A method for manufacturing an acoustic panel according to any one of claims 1 to 23, comprising: A tennis ball cut according to the flexible joints between the textile parts, A preparation of a structure comprising at least one wall element with a thickness between 0.7 and 3 cm and comprising at least one slot with a height H between 0.5 and 2 cm, more particularly between 0.6 and 1.75 cm, 19 Inserting the cut-up tennis balls into the slots 26. Manufacturing method according to claim 25, wherein said preparation of the structure comprises an assembly of n wall blocks, each wall block having two ends each provided with tenons and at least two lateral pillars, with each tenon fitting into each mortise.

27. A manufacturing process according to claim 25 or 26 comprising the step of coloring the balls or half-balls, wherein said balls or half-balls are brought into contact with an aqueous solution at a temperature above 60°C, preferably a temperature of at least 80°C, for example between 80°C and 90°C or, preferably, a temperature of at least 90°C, or even close to 100°C, preferably for a period of 10 minutes.

28. The process according to claim 27 wherein the coloring is carried out from a mixture of dyes selected from blue dye, red dye, yellow dye and black dye, said mixture of dyes being made in amounts suitable for giving the desired color.

29. The process according to claim 28, wherein the blue dye is CAS 3351-05-01 or CAS 67827-60-5, and / or the red dye is CAS 71873-39-7, and / or the yellow dye is CAS-70865-20-2 and / or the black dye is CAS 57693-14-8, optionally further including CAS 3351-05-01 (blue) and / or CAS 68959-00-2.

30. The method according to any one of the preceding claims 25 to 29 wherein the panel is a checkerboard (61, 70), preferably said checkerboard (61, 70) being as defined in claim 19.

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