JP2014109118A - Sound absorption panel using paper core material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an optimal sound space including a low-pitched sound region to be realized, the optimal sound space being formed of a sound insulation material layer, an acoustic absorption layer, and an air layer of a paper core layer, by filling various acoustic absorption materials into a functional opening and a core of the paper core layer.SOLUTION: A functional opening 10 is formed in a paper core material 4, a low-pitched sound absorption material 12 such as glass wool is filled therein to make a paper core layer 1 (d). An acoustic absorption layer 20 is made of a fiber hard board obtained by compressing a textile material. A sound insulation layer 30 is made of a gypsum board. The acoustic absorption layer 20 is brought into close contact with one surface 6 of the paper core layer 1 while the sound insulation layer 30 is brought into close contact with the other surface 6a, thereby configuring an integrated panel 40 with every layers laminated (b) to (d). The panel 40 is provided with a frame material 42 having a U-shaped cross section such as a metallic frame on its four sides, and an external surface 21a of the acoustic absorption layer 20 and an external surface 31a of the sound insulation layer 30 are respectively covered by decorative cloths 44, 44 (a), (b).

Description

  The present invention relates to a sound absorbing panel using a paper core material whose main purpose is to adjust acoustic conditions by using gaps between plates formed of paper core materials such as a honeycomb core and a bias core. This sound absorbing panel is used for a partition or the like.

Conventionally, many panels using a honeycomb core material as a reinforcing material have been proposed. For example, there has been a proposal for configuring a panel by housing a honeycomb core material in a frame chamber partitioned by horizontal pieces (Patent Document 1). In this case, the honeycomb core material was used as a reinforcing material, and was spread without gaps in the frame chamber.
Moreover, paying attention to the sound absorbing effect of the special felt material, there has also been a proposal for realizing a remarkable sound absorbing effect by interposing an air layer between the special felt plate and the sound insulating plate (Patent Document 2).

JP-A-7-96569 JP2009-264029

The honeycomb core material is made of kraft paper, and has the effect of combining light weight and strength, but the board stretched on the surface on which the honeycomb core material is spread is a laminate of aluminum foil, kraft paper and vinyl chloride. It is simply a structure that pursues lightness and durability, and no consideration is given acoustically.
A panel made of a combination of a special felt board and a sound insulation board, which has a sound absorption effect mainly on the high frequency range on one side and a sound insulation effect on the other side, is ideal for partitioning offices. The effect was not considered. In this case, an air layer between the special felt plate and the sound insulating plate is indispensable to exhibit an effective sound absorbing effect. However, the air layer only needs to be a gap, and the air layer itself has a sound absorbing effect. There was no.

  Therefore, in the present invention, a sound absorbing layer is provided on one side of the paper core layer made of paper core material, a sound insulating layer is provided on the other side, and the paper core material is disposed in the air layer, so that the effect of the air layer in the gap between the cores is achieved. In addition, focusing on the vibration performance of the paper material surrounding each core of the paper core layer, the overall sound absorption performance was improved. Moreover, since the opening was formed in the paper core layer to accommodate the low-frequency absorber and the sound absorption performance was improved by dividing the sound range, the above problems were solved.

That is, this invention is a sound absorption panel using the paper core material characterized by having been comprised as follows.
(1) A paper core layer is formed using a paper core material obtained by laminating a large number of “strip-shaped paper materials”.
(2) A sound absorbing layer formed by compressing a fiber material into a plate shape on one surface of the paper core layer is fixed in close contact with each other or with a gap interposed therebetween.
(3) A sound insulation layer is adhered and overlapped on the other surface of the paper core layer, or overlapped with a gap interposed therebetween, and fixed.

Another invention is a sound-absorbing panel using a paper core material, which is characterized as follows.
(1) A paper core layer is formed using a paper core material obtained by laminating a large number of “strip-shaped paper materials”.
(2) A sound absorbing layer formed by compressing a fiber material into a plate shape on one surface of the paper core layer is fixed in close contact with each other or with a gap interposed therebetween.
(3) A sound insulation layer is adhered and overlapped on the other surface of the paper core layer, or overlapped with a gap interposed therebetween, and fixed.
(4) In the paper core layer, functional openings are formed in a portion where a part of the paper core material is removed or in a portion where the paper core material is not disposed.
(5) A low frequency range absorbing material is accommodated in the functional opening.

Another invention is a sound-absorbing panel using a paper core material, which is characterized as follows.
(1) A paper core layer is formed using a paper core material obtained by laminating a large number of “strip-shaped paper materials”.
(2) A sound absorbing layer formed by compressing a fiber material into a plate shape on one surface of the paper core layer is fixed in close contact with each other or with a gap interposed therebetween.
(3) A sound insulation layer is adhered and overlapped on the other surface of the paper core layer, or overlapped with a gap interposed therebetween, and fixed.
(4) In the paper core layer, a bass sound absorbing material is accommodated in a selected core of the paper core material.

  In each of the above inventions, the sound absorbing panel uses a paper core material in which a reinforcing inner crosspiece is disposed at least at one edge of the functional opening.

  The paper core material formed by laminating a number of “strip-shaped paper materials” is a concept including a paper honeycomb having a so-called hexagonal core, a bias core having a parallelogram core, and the like, and is not limited to the core shape. .

  In addition, the above-described lamination in which the layers are fixed is a case where the layers are mainly adhered and laminated. However, the layers are moved to each other at least on the outer peripheral side of the paper core material by some means other than adhesion without adhesion. Including not to be.

In the present invention, a paper core layer made of a paper core material, an absorption layer, and a sound insulation layer are laminated to constitute a panel. Therefore, if the panel is arranged with the outer surface facing the sound source that should absorb the panel, first, the absorption layer The sound in the high frequency range is absorbed, passes through the air layer in the core of the paper core material, and the sound reflected by the inner surface of the sound insulation layer passes again through the air layer in the core of the paper core material, It is absorbed again from the inner surface side. At this time, the sound component that has passed through the absorption layer is diffusely reflected on the surface of the paper core of the paper core material, and part of it is absorbed by the paper material, so that the sound absorption performance can be improved.
In addition, when the functional opening is provided, a component including a low frequency range that has passed through the sound absorbing layer can be absorbed by the bass absorbing material in the functional opening, and when not provided by the bass absorbing material in the core.

  Therefore, this panel absorbs high-frequency components or low-frequency and high-frequency components according to the nature of the sound source, or according to the sound of the sound range that you want to hear or do not want to hear on the sound insulation layer side. An acoustic space can be constructed. In this case, the position of the functional opening can be moved, or the acoustic properties in the paper core of the paper core material can be easily changed.

FIG. 1 is a panel of an embodiment of the present invention, (a) is a front view with a frame member and a decorative cloth attached, (b) AA sectional view, (c) is a perspective view of the panel, and (d) is a panel. FIG. FIG. 2 shows a paper core material used in an embodiment of the present invention, in which (a) shows a folded state before spreading, and (b) shows a spread use state. FIG. 3 is a front view of a panel using another frame material of the present invention. FIG. 4 is an exploded perspective view of a panel using another frame material of the present invention. FIG. 5 is an exploded perspective view of a panel using another frame material of the present invention. 6 (a) to 6 (f) are front views showing other functional openings of the present invention. 7A and 7B are cross-sectional views showing the structure of another mechanism opening. FIGS. 8A to 8F are longitudinal sectional views of an embodiment in which gaps are provided between the respective layers. FIG. 9 is a graph of the experimental results of measuring the sound absorption performance of the fiber hard plate, where (a) shows the reverberation chamber method absorptivity measurement and (b) shows the transmission loss measurement.

1. Embodiment of panel 40

(1) If the base material 3 which laminated | stacked the strip | belt-shaped kraft materials 2 and 2 and adhered and laminated | stacked is comprised (FIG. 2 (a)) and the both ends 3a and 3a of the base material 3 are drawn, an aspect ratio will be obtained. A paper core material (so-called bias core) 4 is formed by obliquely arranging rectangular cores 5 and 5 of 1: 2 (FIG. 2B). The paper core material 4 is formed with a thickness t ₁ , a width D ₁ , and a height H, and the paper core material 4 is cut and removed at the center to form a functional opening 10 (FIG. 1D).
Here, since the functional opening 10 is cut and removed, the thickness is t ₁ (= the thickness of the paper core material 4), and is rectangular in a front view, in a rectangular parallelepiped shape perpendicular to the surface in the direction of the thickness t _1. Form. Further, the sound absorbing material 12 (for example, a material obtained by compressing glass wool or polyester resin fiber) is filled in the mechanism opening 10 to form the paper core layer 1 (FIG. 1D).

(2) The sound absorbing layer 20 is configured by compressing the fiber material.
For example, a material containing PET (polyethylene terephthalate) resin fiber and vinyl chloride fiber is compressed, and the sound absorbing layer 20 is formed from this plate as a felt-like plate. The sound absorbing layer 20 is formed with a thickness t ₂ , a width D ₁ , and a length H.
Moreover, the sound absorption layer 20 can also use the material manufactured as follows, for example. Recycled fiber raw material consisting of natural fiber and chemical fiber is defibrated, and as a binder resin, PET resin fiber is mixed with this to make a raw fabric, and this raw fabric is heated to about 50 ° C to 150 ° C and a chill roll is used. A fiber hard plate having a surface weight of 0.5 to 1.0 kg / m ² and an air flow resistance value of 1000 to 4000 N · s / m ³ is formed, and the sound absorbing layer 20 is formed from the fiber hard plate.

In FIG. 9, when this fiber hard plate (thickness 6 mm) was used alone and hung on a rail as a slat of a vertical blind, its acoustic performance was measured. Here, “blind closed” means that the slats are substantially parallel to the rail (the slats are arranged in a plane), and “blind open” means that the slats are about 90 degrees to the rail. Represents the state. The back air layer between the slat and the wall is set to 100 mm. The “aluminum horizontal blind” is a blind in which a large number of slats arranged in the horizontal direction are arranged vertically. Further, in FIG. 9B, “window glass alone” is an opening of only window glass that does not use a blind, and “window glass / sound absorption blind closed” is the vertical blind of FIG. 9A on the window glass. "Window glass / sound absorption blind open" is an opening that is used together with the vertical blind shown in FIG. 9A in the open state.
It can be seen that both the measurement of the reverberation chamber method sound absorption coefficient in FIG. 9A and the transmission loss in FIG. 9B have outstanding sound absorption performance at 1000 Hz or more when the blind is closed.

(3) The sound insulation layer 30 is formed from a so-called gypsum board. Instead of the gypsum board, other materials having sound insulation performance can also be used.
For example, a wavy intermediate material may be sandwiched between a front surface material and a back surface material and integrally molded (not shown). In this case, the intermediate material, the front surface material, and the back surface material are all made of polypropylene resin or the like.

(4) The sound absorbing layer 20 is adhered to one surface 6 of the paper core layer 1 and the sound insulating layer 30 is adhered to and adhered to the other surface 6a to form an integrated panel 40 in which the layers are laminated (FIG. 1B). To (d)). In this case, the paper core layer 1, the sound absorbing layer 20, and the sound insulating layer 30 are laminated with the upper edges 8, 23, 33, the lower edges 8a, 23a, 33a, and the side edges 7, 22, 32 aligned.
In this case, usually, an adhesive is applied to the entire surface of the plate-like end surfaces of the one surface 6 and the other surface 6a of the paper core layer 1, and the inner surface 21 of the sound absorbing layer 20 and the inner surface 31 of the sound insulating layer 30 are respectively bonded and laminated. To do. In this case, an adhesive may be applied and laminated on the entire inner surface 31 of the sound insulation layer 30, but the surfaces 21 and 21a of the sound absorption layer 20 need to allow air to pass through. Do not cover.

2. Use of panel 40

(1) Since the panel-like sound absorbing layer 20 and the sound insulating layer 30 are bonded and fixed to both surfaces of the paper core layer 1, the panel 40 can be arranged independently, but a frame member 42 can also be provided. In general, considering the workability of attaching adjacent panels 40, 40 and attaching the panel 40 to a wall or ceiling, it is made of metal or hard resin and has a U-shaped frame material 42 (vertical frame material 42a, The horizontal frame member 42b) is provided on the four circumferences (FIGS. 1A and 1B).
Further, the outer surface 21a of the sound absorbing layer 20 and the outer surface 31a of the sound insulating layer 30 of the panel 40 are respectively covered with decorative cloths 44 and 44, and the four circumferences of the decorative cloth 44 are frame members 42 and the panel 40 (the sound absorbing layer 20 and the sound insulating layer 30). (FIGS. 1A and 1B).
In this case, the decorative cloth 44 needs to be made of, for example, a woven fabric of fibers, and a through hole through which air passes between the front surface and the back surface of the fibers. Since an arbitrary pattern can be formed, it can be appropriately selected and used according to the preference of the installation space.

(2) The panel 40 “attached with the frame 42 and the decorative cloth 44” formed as described above, or the single panel 40 “without using the frame material 42 and the decorative cloth 44” has a sound absorbing layer on the sound source side to be absorbed. Twenty outer surfaces 21a are used. Select the size and position of the functional opening 10 and the performance of the sound absorbing material to be used. For example, it is effective to absorb the low frequency range at a certain point inside the wall or ceiling surface of the audio viewing room or inside the room space. If you want to build a sound space, use a panel filled with low-frequency absorption material by forming a large functional opening according to the desired low-frequency sound absorption performance, and if you want to absorb high sound range, A panel that does not form the functional opening 10 is used in combination. In this case, a panel having a desired sound absorption performance can be configured with a small number of sheets without preparing a large number of panels having various sound absorption ranges.
Moreover, since the functional opening 10 and the bass sound absorber 12 can be formed in any size, position, and depth with a single panel 40, a single panel can provide a high-frequency absorption region and a low-frequency absorption region. Can be set (not shown).

(3) Similarly, if the functional opening 10 is configured according to the generation source of low-frequency noise and high-frequency noise by using it as a partition, noise at adjacent locations can be efficiently reduced. The above-mentioned low-frequency noise or high-frequency noise means “noise including a relatively high sound range” or “noise including a relatively low sound range”. In general, a frequency lower than 1000 Hz is considered as a low sound range (especially 500 Hz or less), and a frequency of 1000 Hz or higher is considered as a high sound range (especially 1500 Hz or more).

(4) In this case, the position / shape of the functional opening 10 is
Two rectangular functional openings 10 are provided in the upper and lower parts, respectively (a).

  • Two circular functional openings are provided at the top and bottom, respectively (b).

  A function opening 10 having a horizontally long belt shape (a horizontally long rectangle) is provided at the center (c).

  -Two horizontally long strip-shaped (horizontal rectangular) functional openings 10 are provided at the top and bottom (d).

  -One vertically long (long rectangular) functional opening 10 is provided in the center (e).

  -Two vertically long (vertical rectangular) functional openings 10 are provided at both left and right ends (f).

Etc., and configured according to desired design conditions (FIG. 6).

(5) Further, in the above embodiment, functional apertures 10 (although that is, the thickness was constituted by t ₁₎ is constituted through the paper core layer 4, mechanism opening 12 provided from one surface 6 side other surface 6a The mechanism opening 12 provided from the other surface 6a does not have to reach the one surface 6 side, and the thickness of the functional opening 10 can be arbitrarily determined according to desired performance. (Not shown).

(6) In the above, the dimension of the panel 40 (= the dimension of the paper core layer) is, for example,
D ₁ = about 900 to 1200 mm H = 200 mm to about the ceiling height. The thickness t ₁ of the paper core layer 1 is generally based on the standard of the paper core material 4, but if the cores 5 and 5 of the paper core layer 1 are considered as air layers,
It is desirable that t ₁ = about 50 mm to 300 mm.
The thickness t ₂ of the sound absorbing layer 20 is
t ₂ = 3 mm to 10 mm
It is set according to the desired high-frequency absorption performance.
The thickness t ₃ of the sound insulation layer 30 depends on the thickness of the gypsum board,
t ₃ = 9 mm to 15 mm
Degree. If the sound insulation layer 30 is made of a steel plate,
It is possible even when t ₃ is about 0.2 mm to 0.6 mm.

3. Other embodiments

(1) In the above-described embodiment, the frame member 42 having a U-shaped cross section is used. However, the rod-like vertical frame member 46 and the horizontal frame member 46a can be fixed to the four sides of the panel 40 in a frame shape (FIG. 3). .

(2) Moreover, in the said embodiment, the inner crosspiece 48 (vertical inner crosspiece 48a, horizontal inner crosspiece 48b) of thickness t1 can also be previously fixed to the four periphery of the paper core layer 1 (FIG. 4). The four circumferences of the paper core layer 1 are formed smaller by the inner crosspiece 48 (vertical inner crosspiece 48a, horizontal inner crosspiece 48b) having a thickness t1, and the vertical inner crosspiece 48a and the horizontal inner crosspiece 48b are preliminarily formed as the paper core layer. 1 is fixed to the outer periphery (upper and lower edges 8 and 8a, side edges 7 and 7), and the sound absorbing layer 20 and the sound insulating layer 30 are laminated and fixed to the paper core layer 1 to which the inner crosspieces 48a and 48b are fixed (FIG. 4). . Therefore, in this case, the four circumferences of the sound absorbing layer 20 and the sound insulating layer 30 are fixed to the longitudinal inner crosspiece 48a and the horizontal inner crosspiece 48b. Further, in this case, it is sufficient that at least one inner rail member 48a, 48b for attachment is provided (not shown) instead of four rounds.

(3) Moreover, in the said embodiment, the reinforcement inner crosspiece 49 for reinforcement or attachment can also be provided in the inside of the paper core layer 1 (FIG. 5). In particular, it is effective to provide at the edge portion of the functional opening 10.
For example, horizontal inner crosspieces 48b and 48b are provided at both upper and lower ends of the paper core layer, and reinforcing inner crosspieces 49 and 49 are also provided at the lower edge of the upper edge of the functional opening 10 (FIG. 5). Further, the reinforcing inner crosspiece 49 can be disposed so as to surround the functional opening 10 (not shown).

(4) Moreover, in the said embodiment, although the functional opening 10 was provided and it filled with the low frequency range absorber, the functional opening 10 was abbreviate | omitted and the core 5 of paper core material in the position where absorption of a low frequency range is calculated | required, 5 may be filled with the low-frequency absorber 12 (not shown).

(5) Moreover, in the said embodiment, although the adhesive agent was apply | coated to the front surface of the paper core layer 1, and the sound absorption layer 20 and the sound-insulation layer 30 were laminated | stacked, the paper material (craft paper) of each core of the paper core layer 1 If the movement of the sheet is made free, it is possible to absorb noise by making better use of the vibration of the paper material, so that only the outer peripheral part can be adhered and the center part side can be made free (not shown).
In particular, when the frame member 42 is used, the outer periphery of the paper core layer 1, the outer periphery of the sound absorbing layer 20, and the outer periphery of the sound insulating layer 30 can be bonded and fixed to the frame member 42, respectively. The paper core layer 1 and the sound insulation layer 30 are only required to be laminated, and need not be bonded.

(6) Moreover, in the said embodiment, although the mechanism opening 10 of the depth t1 was formed similarly to the thickness t1 of the paper core layer 1, it can also be set as another structure (FIG. 7).
That is, the mechanism opening 10 having a depth t5 can be formed only on the one surface 6a side (sound absorbing layer 20 side) of the paper core layer 1 (FIG. 7A). In this case, the bass sound absorbing material 12 is not disposed in the paper core layer 1 near the sound absorbing layer 20 side.
Similarly, a mechanism opening 10 having a depth t5 can be formed only on the other surface 6 side (sound insulation layer 30 side) of the paper core layer 1 (FIG. 7B). In this case, the low sound absorber 12 is not disposed on the paper core layer 1 near the sound insulating layer 30 side.

(7) Moreover, in the said embodiment, when absorbing a noise more utilizing the vibration of the paper material (craft paper) around each core 5 and 5 of the paper core layer 1, the functional opening 10 is formed. The filling of the bass sound absorbing material can be omitted, or the filling of the bass sound absorbing material into the core can be omitted. In this case, the paper core layer 1, the sound absorbing layer 20, and the sound insulating layer 30 are simply laminated (not shown).

(8) Moreover, in the said embodiment, although the sound-absorbing layer 20 was closely_contact | adhered to the one surface 6 of the paper core layer 1, and the sound-insulation layer 30 was each closely_contact | adhered to the other surface 6a, it is also possible to make it not closely_contact | adhere. In this case, in order to maintain the laminated state, it is desirable to use the frame member 42 (vertical frame member and / or horizontal frame member 42b) or another spacer.
For example, the sound absorbing layer 20 may be disposed on the one surface 6 of the paper core layer 1 and the sound insulating layer 30 may be disposed with the gap 14 formed on the other surface of the paper core layer 1 (FIGS. 8A and 8D). . In this case, when the functional opening 10 is not formed (FIG. 8A), the mechanism opening 10 may be formed and filled with the bass absorber 12 or the like (FIG. 8D). Further, in this case, a spacer 51 is provided in order to maintain the gap 14 (FIG. 8A shows a chain line 51). In the following, in order to maintain the gaps 14 and 15 in each example, a spacer 51, a frame member 42, and the like can be similarly used (not shown).
Further, the sound absorbing layer 20 can also be disposed by adhering the sound insulating material layer 30 to the other surface 6a of the paper core layer 1 and leaving a gap 15 in the one surface 6 of the paper core layer 1 (FIGS. 8B and 8E). )). In this case, when the functional opening 10 is not formed (FIG. 8B), the mechanism opening 10 may be formed and filled with the bass absorber 12 or the like (FIG. 8E).
Further, the sound absorbing layer 20 can be disposed with a gap 15 on one surface 6 of the paper core layer 1, and the sound insulating material layer 30 can be disposed with a gap 14 on the other surface 6a (FIGS. 8C and 8F). )). In this case, when the functional opening 10 is not formed (FIG. 8C), the mechanism opening 10 may be formed and filled with the bass absorber 12 or the like (FIG. 8F).

DESCRIPTION OF SYMBOLS 1 Paper core layer 4 Paper core material 5 Core of paper core material 6 One surface 6a of a paper core layer The other surface 7 of a paper core layer 7 The side edge 8 of a paper core layer The upper edge 8a of a paper core layer The lower edge 10 of a paper core layer Opening 12 Low sound absorbing material 14, 15 Interlayer gap 20 Sound absorbing layer 21 Sound absorbing layer inner surface 21 a Sound absorbing layer outer surface 22 Sound absorbing layer side edge 23 Sound absorbing layer upper edge 23 a Sound absorbing layer lower edge 30 Sound insulating layer 31 Sound insulating layer inner surface 31a Outer surface of sound insulation layer 32 Side edge of sound insulation layer 33 Upper edge of sound insulation layer 33a Lower edge of sound insulation layer 40 Panel 42 Frame material (FIG. 1)
42a Vertical frame material 42b Horizontal frame material 44 Decoration cloth 46 Frame material (FIG. 3)
46a Vertical frame material 46b Horizontal frame material 48 Inner frame material (Fig. 4)
48a Vertical crosspiece 48b Horizontal internal crosspiece 49 Reinforcement internal crosspiece (Fig. 5)
51 Spacer

Claims (4)

A sound-absorbing panel using a paper core material, which is characterized as follows.
(1) A paper core layer is formed using a paper core material obtained by laminating a large number of “strip-shaped paper materials”.
(2) A sound absorbing layer formed by compressing a fiber material into a plate shape on one surface of the paper core layer is fixed in close contact with each other or with a gap interposed therebetween.
(3) A sound insulation layer is adhered and overlapped on the other surface of the paper core layer, or overlapped with a gap interposed therebetween, and fixed. A sound-absorbing panel using a paper core material, which is characterized as follows.
(1) A paper core layer is formed using a paper core material obtained by laminating a large number of “strip-shaped paper materials”.
(2) A sound absorbing layer formed by compressing a fiber material into a plate shape on one surface of the paper core layer is fixed in close contact with each other or with a gap interposed therebetween.
(3) A sound insulation layer is adhered and overlapped on the other surface of the paper core layer, or overlapped with a gap interposed therebetween, and fixed.
(4) In the paper core layer, functional openings are formed in a portion where a part of the paper core material is removed or in a portion where the paper core material is not disposed.
(5) A low frequency range absorbing material is accommodated in the functional opening. A sound-absorbing panel using a paper core material, which is characterized as follows.
(1) A paper core layer is formed using a paper core material obtained by laminating a large number of “strip-shaped paper materials”.
(2) A sound absorbing layer formed by compressing a fiber material into a plate shape on one surface of the paper core layer is fixed in close contact with each other or with a gap interposed therebetween.
(3) A sound insulation layer is adhered and overlapped on the other surface of the paper core layer, or overlapped with a gap interposed therebetween, and fixed.
(4) In the paper core layer, a bass sound absorbing material is accommodated in a selected core of the paper core material. The sound-absorbing panel using the paper core material according to any one of claims 1 to 3, wherein a reinforcing inner crosspiece is disposed at least at one edge of the functional opening.

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