WO2022091287A1

WO2022091287A1 - Sound absorbing material

Info

Publication number: WO2022091287A1
Application number: PCT/JP2020/040597
Authority: WO
Inventors: 元基正木; 迪斉松本; 昌哉三田村
Original assignee: 三菱電機株式会社
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2022-05-05
Also published as: CN116438340A; JPWO2022091287A1; JP7438392B2; DE112020007744T5

Abstract

The present invention comprises: fiber masses (2) in each of which one or a plurality of fibers (6) are entangled to form a mass, and each of which has first gaps (8) inside the mass and a first resin particles (3) trapped by the first gaps (8); and second resin particles (4) which are disposed in second gaps (9) formed between a plurality of fiber masses (2), and which have a particle size larger than that of the first resin particle (3). Thus, it is possible to provide a sound absorbing material (1) having excellent sound absorption properties in both a high frequency range and low frequency range, wherein high frequency range sound absorption properties are improved by the first resin particles (3) trapped in the first gaps (8), and low frequency range sound absorption properties are improved by the second resin particles (4) disposed in the second gaps (9).

Description

Sound absorbing material

This disclosure relates to sound absorbing materials used for noise control of electrical equipment and automobiles.

Since noise generated from electrical equipment such as air conditioners and refrigerators and automobiles includes sound waves in the low frequency range and high frequency range, a sound absorbing material having a wide range of sound absorbing performance from the low frequency range to the high frequency range is required. ing. Conventionally, a sound absorbing material in which a powder material such as polyurethane resin is attached to a porous material such as glass wool is known, and Patent Document 1 uses a porous material having a fine powder material attached to a sheet having a certain thickness. Disclosed is a technique for improving the sound absorption performance in a high frequency range by molding the product into a glass.

Japanese Unexamined Patent Publication No. 2019-44548 (see, in particular, Table 1, FIG. 3, etc.)

However, although the sound absorption performance in the high frequency range can be improved by appropriately selecting the particle size of the fine powder material to be adhered to the porous material, it is difficult to improve the sound absorption performance in the low frequency range. Therefore, it has been a problem to obtain a sound absorbing material having improved sound absorbing performance in a high frequency range and improved sound absorbing performance in a low frequency range.

The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a sound absorbing material having excellent sound absorbing performance in a low frequency range and a high frequency range.

The sound absorbing material of the present disclosure includes a fiber mass in which one or a plurality of fibers are intertwined to form a mass, and a fiber mass having a first void and a first resin particle trapped in the first void inside the mass, and a plurality of fibers. It includes a second resin particle which is arranged in a second void formed between the fiber lumps and has a particle size larger than the particle size of the first resin particle.

According to the present disclosure, the first resin particles captured in the first voids improve the sound absorption performance in the high frequency range, are arranged in the second voids, and are larger than the particle size of the first resin particles. Since the second resin particles having a diameter improve the sound absorbing performance in the low frequency range, it is possible to obtain a sound absorbing material having excellent sound absorbing performance in the low frequency range and the high frequency range.

It is sectional drawing which shows the schematic structure of the sound absorbing material in Embodiment 1. FIG. It is sectional drawing which shows the structure of the fiber mass of the sound absorbing material in Embodiment 1. FIG. It is a graph which shows the sound absorption coefficient of the sound absorbing material in Embodiment 1. FIG. It is a graph which shows the particle size ratio dependence of the sound absorption coefficient of the sound absorbing material in Embodiment 2. It is a graph which shows the particle size dependence of the 2nd resin particle of the sound absorption coefficient of the sound absorbing material in Embodiment 2. It is a graph which shows the fiber mass diameter dependence of the sound absorption coefficient of the sound absorbing material in Embodiment 3. It is a graph which shows the bulk density dependence of the sound absorption coefficient of the sound absorbing material in Embodiment 4. It is sectional drawing which shows the schematic structure of the sound absorbing material in Embodiment 5.

As a result of diligent studies, the present inventors have made a structure in which a fiber mass in which fine resin particles are trapped in a fiber and a coarse resin particle between a plurality of fiber masses are present in a low frequency region and a high frequency. It has been found that a sound absorbing material having excellent sound absorbing performance in both ranges can be used, and a configuration that improves sound absorbing performance in a wide frequency range can be obtained.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

Embodiment 1.
FIG. 1 is a schematic cross-sectional view showing the sound absorbing material 1 of the first embodiment. The sound absorbing material 1 captures the first resin particles 3 in each of the plurality of fiber lumps 2, and the second gap 9, which is a gap between the plurality of fiber lumps 2, has a diameter larger than that of the first resin particles 3. The configuration is such that the large second resin particles 4 are arranged.

As shown in FIG. 2, the fiber lump 2 is formed by entwining one or a plurality of fibers 6 to form a lump, and the first resin particles 3 are captured by the first void 8 formed inside the lump. Let it be a fiber mass 2. The fiber lump 2 may be formed into, for example, a spherical lump by bending one fiber 6 or by condensing a plurality of fibers 6 together. The fiber mass 2 may have an elliptical shape, a polygonal shape, or the like, or may have a flat shape in which a part of these shapes is flat. All of the plurality of fiber lumps 2 may have one type of shape, or a plurality of types of shapes may be mixed, for example, a spherical shape and a flat shape may be mixed. The fiber mass 2 is large enough to capture the first resin particles 3 in the first voids 8 and to form a second void 9 in which the second resin particles larger than the particle size of the first resin particles 3 can be arranged. You can do it. For example, the diameter of the fiber mass 2 may be about 0.1 mm or more and 100 mm or less. Here, the diameter of the fiber lump 2 means an average diameter, for example, it is assumed that the diameter is measured at about 20 points using a caliper and arithmetically averaged.

The fiber 6 is, for example, an inorganic fiber material such as glass wool, rock wool, carbon fiber, alumina fiber, wollastonite, potassium titanate fiber, a natural fiber material such as cotton and linen, a polyester resin fiber, an aramid resin fiber and the like. One type or a plurality of types may be selected from the organic fiber materials. The wire diameter of the fiber 6 may be determined from the viewpoint of appropriately forming the first void 8 for capturing the first resin particles 3, but may be, for example, 0.1 μm or more and 10 μm or less. Here, the wire diameter of the fiber 6 is obtained from an average value measured at about 20 points in a cross-sectional image of the fiber 6 magnified from 1000 times to 5000 times by using, for example, SEM (Scanning Electron Microscopy).

The first resin particles 3 may be selected from, for example, one or a plurality of types from polyurethane resin, phenol resin, epoxy resin, acrylic resin, polyester resin, polyamide resin, melamine resin and the like. The particle size of the first resin particles 3 may be such that sound absorption performance in a high frequency range can be obtained and the first resin particles 3 are captured in the first void 8. The size of the first void 8 may be adjusted by changing the wire diameter of the fiber 6 according to the particle size of the first resin particles 3. For example, when the particle size of the first resin particles 3 is 1 mm, the wire diameter of the fiber 6 may be 7 μm. Here, the particle size of the first resin particles 3 means an average particle size, and is captured in, for example, an image of the surface or cross section of the fiber mass 2 magnified about 1000 to 5000 times by using SEM. It is assumed that the particle size of the first resin particles 3 is measured at about 20 places and arithmetically averaged.

The second void 9 is provided between the plurality of fiber lumps 2. The size of the second void 9 and the total volume occupied in the sound absorbing material 1 are related to the size of the fiber mass 2. When the filling amount of the fiber lump 2 is the same, as the fiber lump 2 becomes smaller, the ratio of the total volume of the second void 9 to the sound absorbing material 1 in the same volume becomes larger. When the second void 9 becomes large, the second resin particles 4 having a large particle size can be arranged in the second void 9. Further, by dispersing the fiber mass 2, the second resin particles 4 can be dispersed and arranged.

The second resin particles 4 may be selected from one or more types from polyurethane resin, phenol resin, epoxy resin, acrylic resin, polyester resin, polyamide resin, melamine resin and the like. When coarse particles are used for the second resin particles 4, the vibration energy of sound waves in the low frequency region is efficiently converted into thermal energy, so that the sound absorption performance in the low frequency region can be improved. Therefore, as the second resin particles 4, those having a larger particle size than the first resin particles 3 are used. For example, when the particle size of the first resin particle 3 is 0.6 mm and the diameter of the fiber mass 2 is 26 mm, the particle size of the second resin particle 4 can be 21 mm. The particle size of the second resin particles 4 means an average particle size, and is obtained by measuring about 20 points using an optical microscope or a nogis and arithmetically averaging the particles.

Here, from the viewpoint of capturing the first resin particles 3 in the first voids 8 and arranging the second resin particles 4 in the second voids 9, the weight of the fiber lump 2 and the first resin particles 3 The ratio to the total weight of the resin particles including the second resin particles 4 may be 70:30 to 95: 5. It may be preferably 80:20 to 90:10, and if it is 80:20 to 90:10, the first resin particles 3 are efficiently captured in the first void 8 and the second void 9 is filled with the first resin particles 3. The resin particles 4 of 2 can be efficiently arranged. The ratio of the weight of the first resin particles 3 to the weight of the second resin particles 4 may be 5:95 to 50:50. It is preferably 20:80 to 40:60, and 20:80 to 40:60 makes it easy to disperse and arrange the second resin particles 4 in the second void 9.

The total resin particle content ratio, which is the ratio of the total resin particle weight to the sound absorbing material 1, is about 400 when the inorganic fiber material is used for the fiber mass 2 and the mixture of the first resin particles 3 and the second resin particles 4 is used. It can be verified by heat treatment at ~ 500 ° C. and incineration. Specifically, it can be calculated by the following equation 1 from the weight before the heat treatment (W _before ) and the weight _after the heat treatment (Wafter).

Total resin particle content ratio = (1-W _after / W _before ) x 100 ... (Equation 1)

Further, the bulk density of the sound absorbing material 1 is the volume of the bag-shaped package 5 when the fiber lump 2, the first resin particles 3 and the second resin particles 4 are put into, for example, a bag-shaped package 5. , The total weight of the filler containing the fiber lump 2, the first resin particle 3 and the second resin particle 4, can be calculated by using the following formula 2.

Bulk density of sound absorbing material 1 = total weight of filler ÷ volume of package 5 ... (Equation 2)

Here, the package 5 is not limited to the bag shape, but may be a sheet shape. By using the package 5, it is possible to prevent the fibers 6, the first resin particles 3 and the second resin particles 4 from scattering. The package 5 may have ventilation holes to the extent that the sound incident on the sound absorbing material 1 from the outside is not reflected and the fibers 6, the first resin particles 3 and the second resin particles 4 are not scattered. Specifically, glass cloth, non-woven fabric, synthetic fiber cloth and the like may be used. These may be used as one sheet, a single species may be stacked, or a plurality of species may be stacked in combination. In particular, when it is desired to prevent the fibers 6, the first resin particles 3 and the second resin particles 4 from scattering, such as when the sound absorbing material 1 is used indoors, it is preferable to use a plurality of the fibers 6 in layers. Further, it can be used by directly arranging it in a gap or the like of an object generating noise without using the package 5. In this case, the volume of the package 5 may be replaced with the volume of the gap between the objects to obtain the bulk density of the sound absorbing material 1.

Next, the results of producing a test piece of the sound absorbing material 1 of the present embodiment and evaluating the sound absorbing performance will be described. In the evaluation of the sound absorption performance, after measuring the sound absorption coefficient of each sound absorbing material 1 by the vertical incident method described in JIS A1405-2: 2007 using a sound absorption coefficient measuring device, a comparative example at frequencies f of 500 Hz and 1000 Hz. The relative value of the sound absorption coefficient of each sound absorbing material 1 was calculated based on the sound absorption coefficient of the sound absorbing material 1 of No. 1, and the relative values of the sound absorbing rate of each sound absorbing material 1 were compared.
<Example 1>
As the first resin particles 3, polyurethane resin particles having a particle size of 0.6 mm and a total weight of 0.84 g were prepared, and as the second resin particles 4, polyurethane resin particles having a particle size of 21 mm and a total weight of 1.96 g were prepared. Using glass wool having a wire diameter of 4 μm as the fiber 6, a plurality of fiber lumps 2 in which the first resin particles 3 were captured were formed, and a test piece in which the second resin particles 4 were arranged around the fiber lumps 2 was formed. Made. A test piece having a total weight of 18.8 g was placed in a bag-shaped package 5 made of glass cloth having a circular diameter of 100 mm and a thickness of 25 mm in a plan view to obtain a sound absorbing material 1 having a bulk density of 96 kg / m ³ .

<Comparative Example 1>
As a comparative example, the sound absorbing material 1 was obtained in the same manner as in Example 1 without adding the first resin particles 3 and the second resin particles 4.
<Comparative Example 2>
The total weight of the first resin particles 3 was 2.8 g, and the sound absorbing material 1 was obtained in the same manner as in Example 1 without adding the second resin particles 4.

The conditions of Example 1, Comparative Example 1 and Comparative Example 2 are as shown in Table 1 below.

FIG. 3 compares the relative values of the sound absorption coefficient with and without the presence / absence of the first resin particles 3 and the second resin particles 4. As can be seen from Table 1 and FIG. 3, the sound absorbing material 1 of the first embodiment including the first resin particles 3 and the second resin particles 4 includes both the first resin particles 3 and the second resin particles 4. It has a better sound absorption coefficient than the sound absorbing material 1 of Comparative Example 2 in which the first resin particles 3 are added but the second resin particles 4 are not added.

At 500 Hz, which is a low frequency region, the relative value of the sound absorption coefficient of Example 1 is 1.96, which is improved from 1 of Comparative Example 2, and the effect of the second resin particle 4 is shown. Further, in the high frequency range of 1000 Hz, the relative value of the sound absorption coefficient of Example 1 is 1.15, which is improved from 1 of Comparative Example 2, and even if the second resin particles 4 are provided, the high frequency range is provided. It is shown that the sound absorption coefficient of is not reduced.

In this way, the second resin particles 4 have a particle size larger than the particle size of the first resin particles by forming the fiber mass 2 in which the first resin particles 3 are captured in the first voids 8. By arranging the above in the second void 9 formed by the plurality of fiber lumps 2, it is possible to obtain the sound absorbing material 1 having excellent sound absorbing performance in both the low frequency region and the high frequency region.

Although an example of forming a lump for producing a fiber lump 2 by entwining one or a plurality of fibers 6 is shown, a molded product such as a mat shape may be cut to produce a lump. By cutting and using a molded product such as a mat shape, a fiber mass 2 having a desired size can be produced. For cutting, various cutting machines such as a knife cutting type cutting machine, a crushing hammer rotary cutting machine, a roll rotary cutting machine, and a pin disk rotary cutting machine can be used.

Further, it is preferable that the fiber lump 2 and the second resin particles 4 have a structure in which the fiber lumps 2 and the second resin particles 4 are evenly dispersed in the entire sound absorbing material 1. When the fiber lump 2 and the second resin particles 4 are evenly dispersed, the sound absorbing material 1 has a structure effective for absorbing sound waves in a low frequency range and a structure effective for absorbing sound waves in a high frequency range. Therefore, deterioration of sound absorption performance due to individual differences is suppressed. Further, the second resin particles 4 may be unevenly distributed as long as the sound absorption performance is not significantly deteriorated.

Further, the first void 8 can be provided by three-dimensionally entwining the fibers 6, and the bulk density of the sound absorbing material 1 may be adjusted to an appropriate range depending on the amount of the first void 8. When the bulk density is set to an appropriate range, when the fiber mass 2 and the second resin particles 4 are mixed, the first resin particles 3 are easily captured by the first voids 8, and the sound absorbing material 1 contains sound waves. Since a plurality of incident paths can be formed, the sound absorbing material 1 has a structure that easily absorbs sound. The size of the first void 8 is related to the wire diameter and density of the fiber 6, and when the wire diameter of the fiber 6 becomes smaller and the density becomes higher, the first void 8 becomes smaller. When the first void 8 becomes smaller, the first resin particles 3 are more likely to be captured by the first void 8.

Further, in the production of the sound absorbing material 1 of the present embodiment, the fiber lump 2 in which the first resin particles 3 are captured and the second resin particles 4 may be mixed, and the first resin particles 3 and the second resin particles 3 may be mixed. By mixing the lumps formed by the entanglement of the resin particles 4 and the fibers 6 of the above, the treatment of capturing the first resin particles 3 in the lumps to form the fiber lumps 2 and the plurality of second resin particles 4 are formed. The process of arranging the fibers between the fiber lumps 2 may be performed at the same time. In this case, the particle size of the second resin particles 4 is so as not to prevent the second resin particles 4 from being captured by the first voids 8 and the first resin particles 3 from being captured by the first voids 8. Should be adjusted.

Embodiment 2.
In the first embodiment, an example of comparing the presence / absence of the first resin particles 3 and the second resin particles 4 is shown, but in the present embodiment, the particle size of the second resin particles 4 is changed. , An example in which the ratio of the particle sizes is changed will be described. Other configurations are the same as those in the first embodiment. The sound absorption performance was evaluated by the same method as in the first embodiment.

Hereinafter, the ratio of the particle size of the second resin particles 4 to the particle size of the first resin particles 3 is referred to as a particle size ratio. This particle size ratio can be calculated from the particle size of the first resin particles 3 (R ₁ ) and the particle size of the second resin particles 4 (R ₂ ) using the following equation 3.

Particle size ratio = R ₂ ÷ R ₁ ... (Equation 3)

<Example 2>
The sound absorbing material 1 was obtained in the same manner as in Example 1 with the particle size of the second resin particles 4 being 5 mm and the particle size ratio being 8.
<Example 3>
The sound absorbing material 1 was obtained in the same manner as in Example 1 with the particle size of the second resin particles 4 being 13 mm and the particle size ratio being 22.
<Example 4>
The sound absorbing material 1 was obtained in the same manner as in Example 1 with the particle size of the second resin particles 4 being 32 mm and the particle size ratio being 53.

The evaluation results are shown in Table 2. For reference, the evaluation results of Example 1 are reprinted.

From FIG. 4, which is a graph of the sound absorption coefficient of Examples 1 to 4, it can be seen that even if the particle size ratio is changed, the sound absorption coefficient is excellent. Here, the dotted line in FIG. 4 is an auxiliary line showing the behavior of the relative value of the sound absorption coefficient with respect to each particle size ratio.

In the low frequency range of 500 Hz, the relative values of the sound absorption coefficient of Example 2 having a particle size ratio of 8, Example 3 having a particle size ratio 22 and Example 4 having a particle size ratio 53 are 1.69 and 1.92, respectively. , 2.02, which is an improvement from 1 of Comparative Example 2 described above. Further, at 1000 Hz, which is a high frequency region, the relative values of the sound absorption coefficient of Example 2, Example 3, and Example 4 are 1.20, 1.17, and 1.11, respectively, which are improved from 1 of Comparative Example 2. It is shown that the sound absorption coefficient in the high frequency region does not decrease even if the particle size of the second resin particles 4 is changed.

Further, as shown in FIG. 4, if the particle size ratio is increased, the second resin particles 4 are less likely to be captured by the first void 8 inside the fiber mass 2, and are voids between the plurality of fiber masses 2. Since it is easy to disperse and disperse in the second void 9, the particle size ratio is preferably 2 or more, preferably 8 or more, and more preferably 22 or more.

As described above, even if the particle size ratio is changed, the sound absorbing material 1 having excellent sound absorbing performance in the low frequency region and the high frequency region can be obtained. When the particle size ratio is increased, the second resin particles 4 are less likely to be captured in the first voids 8 and are easily dispersed and arranged in the second voids 9, so that both the sound absorption performance in the low frequency region and the high frequency region are improved. An excellent sound absorbing material 1 can be obtained.

In the present embodiment, an example in which the particle size of the second resin particles 4 is changed to adjust the particle size ratio is shown, but the particle size of the first resin particles 3 is changed to adjust the particle size ratio. May be adjusted.

Further, as shown in FIG. 5, the particle size of the second resin particles 4 is preferably 1 mm or more, more preferably 5 mm or more, still more preferably 13 mm or more, from the viewpoint of improving the sound absorption performance in the low frequency range. Just do it.

Embodiment 3.
In this embodiment, an example of changing the diameter of the fiber mass 2 will be described. Other configurations are the same as those in the first embodiment. The sound absorption performance was evaluated by the same method as in the first embodiment.

<Example 5>
The sound absorbing material 1 was obtained in the same manner as in Example 1 with the diameter of the fiber mass 2 being 12 mm.
<Example 6>
The sound absorbing material 1 was obtained in the same manner as in Example 1 with the diameter of the fiber mass 2 being 49 mm.
<Example 7>
The sound absorbing material 1 was obtained in the same manner as in Example 1 with the diameter of the fiber mass 2 being 68 mm.

The evaluation results are shown in Table 3. For reference, the evaluation results of Example 1 are reprinted.

From FIG. 6, which is a graph of the sound absorption coefficient of Examples 1 and 5 to 7, it can be seen that even if the diameter of the fiber mass 2 is changed, the sound absorption coefficient is excellent. Here, the dotted line in FIG. 6 is an auxiliary line showing the behavior of the relative value of the sound absorption coefficient with respect to each diameter.

At 500 Hz, which is a low frequency region, the relative values of the sound absorption coefficient of Example 5 having a diameter of 12 mm, Example 6 having a diameter of 49 mm, and Example 7 having a diameter of 68 mm are 1.94, 1.86, 1, respectively. It is improved from 1.67, which is 1 of Comparative Example 2 described above. Further, at 1000 Hz, which is a high frequency region, the relative values of the sound absorption coefficient of Example 5, Example 6, and Example 7 are 1.17, 1.16, and 1.15, respectively, which are improved from 1 of Comparative Example 2. It is shown that the sound absorption coefficient in the high frequency region does not decrease even if the diameter of the fiber mass 2 is changed.

If the diameter of the fiber lump 2 exceeds 70 mm, the ratio of the second void 9 to the sound absorbing material 1 becomes small, and it may be difficult to arrange the second resin particles 4 in the second void 9. When the diameter of the fiber lump 2 is less than 5 mm, the filler containing the fiber lump 2, the first resin particles 3 and the second resin particles 4 is densely filled in the sound absorbing material 1 and becomes the sound absorbing material 1. It may interfere with the incident of sound waves. Therefore, the diameter of the fiber mass 2 is preferably 5 mm or more and 70 mm or less, more preferably 10 mm or more and 50 mm or less, and further preferably 20 mm or more and 40 mm or less.

As described above, even if the diameter of the fiber mass 2 is changed, the sound absorbing material 1 having excellent sound absorbing performance in both the low frequency region and the high frequency region can be obtained. When the diameter of the fiber mass 2 is appropriately selected, the second resin particles 4 can be easily dispersed and arranged in the second voids 9, and the low frequency range and the high frequency range can be easily arranged without interfering with the incident of sound waves on the sound absorbing material 1. It is possible to obtain a sound absorbing material 1 having excellent sound absorbing performance in the frequency range.

Embodiment 4.
In this embodiment, an example of changing the bulk density of the sound absorbing material 1 will be described. Other configurations are the same as those in the first embodiment. The sound absorption performance was evaluated by the same method as in the first embodiment.

<Example 8>
A sound absorbing material 1 was obtained in the same manner as in Example 1 with a bulk density of 48 kg / m ³ .
<Example 9>
A sound absorbing material 1 was obtained in the same manner as in Example 1 with a bulk density of 150 kg / m ³ .
<Example 10>
A sound absorbing material 1 was obtained in the same manner as in Example 1 with a bulk density of 190 kg / m ³ .

The evaluation results are shown in Table 4. For reference, the evaluation results of Example 1 are reprinted.

From FIG. 7, which is a graph of the sound absorption coefficient of Example 1 and Example 8 to Example 10, it can be seen that even if the bulk density of the sound absorbing material 1 is changed, the sound absorption coefficient is excellent. Here, the dotted line in FIG. 7 is an auxiliary line showing the behavior of the relative value of the sound absorption coefficient with respect to each bulk density.

Relative values of the sound absorption coefficient of Example 8 having a bulk density of 48 kg / m ³ and Example 9 having a bulk density of 150 kg / m ³ and Example 10 having a bulk density of 190 kg / m ³ at 500 Hz, which is a low frequency region. Are 1.90, 2.02, and 1.98, respectively, which are improved from 1 of Comparative Example 2 described above. Further, at 1000 Hz, which is a high frequency region, the relative values of the sound absorption coefficient of Example 8, Example 9, and Example 10 are 1.10, 1.17, and 1.07, respectively, which are improved from 1 of Comparative Example 2. are doing. It has been shown that even if the bulk density of the sound absorbing material 1 is changed, the sound absorbing coefficient in the high frequency range does not decrease at 190 kg / m ³ or less.

If the bulk density of the sound absorbing material 1 is too large, the filler containing the fiber lump 2, the first resin particles 3 and the second resin particles 4 is densely filled, so that the sound wave to the sound absorbing material 1 is charged. It may interfere with the incident. If the bulk density is too small, the filler material is sparsely filled in the sound absorbing material 1, so that the sound waves incident on the sound absorbing material 1 do not reach the first resin particles 3 and the second resin particles 4 and absorb sound. It may be inefficient because it emits from the material 1. Therefore, the bulk density is preferably 30 kg / m ³ or more and 200 kg / m ³ or less, and more preferably 40 kg / m ³ or more and 190 kg / m ³ or less.

In this way, even if the bulk density of the sound absorbing material 1 is changed, it is possible to obtain the sound absorbing material 1 having excellent sound absorbing performance in both the low frequency range and the high frequency range. If the bulk density is properly selected, the sound absorbing material 1 can efficiently absorb sound waves without hindering the incident of sound waves on the sound absorbing material 1, so that the sound absorbing material has excellent sound absorbing performance in both the low frequency range and the high frequency range. 1 can be obtained.

Embodiment 5.
In the present embodiment, an example in which the first resin particles 3 and the magnetic particles 7 are captured in the first voids 8 of the sound absorbing material 1 will be described. Other configurations are the same as those in the first embodiment.

As shown in FIG. 8, the first resin particles 3 and the magnetic particles 7 are captured in the first void 8 of the sound absorbing material 1 to form a fiber mass 2. In such a sound absorbing material 1, the fiber lump 2 can be recovered by applying a magnetic force from the outside. Further, especially when the sizes of the plurality of fiber lumps 2 are different, the sizes can be selected.

For sorting by magnetic force, for example, in a magnetic force sorting device, the relationship between the weight and the magnetic force according to the size of the fiber mass 2 can be used. When the fiber lump 2 becomes larger than a desired size, the fiber lump 2 becomes heavier, and therefore it becomes difficult to move the fiber lump 2 by an attractive force or a repulsive force generated by an external magnetic force. On the other hand, when the fiber lump 2 becomes smaller than a desired size, the fiber lump 2 becomes lighter, so that the fiber lump 2 can be easily moved by an attractive force or a repulsive force generated by an external magnetic force. For example, if the collection destination of the fiber lump 2 is different depending on the amount of movement of the fiber lump 2, the fiber lump 2 having a desired size in which the magnetic particles 7 are captured can be obtained. Here, in the manufacturing process of the sound absorbing material 1, the magnetic particles 7 may be captured by the mass formed by the entanglement of the fibers 6 before the first resin particles 3 are captured, and the mass may be magnetically sorted. In this way, lumps of different sizes can be sorted by size.

The magnetic particles 7 are metal materials such as iron, silicon iron, nickel, permalloy, Fe-Si-Al, sentust, alnico magnets, sumalium cobalt magnets, neodymium iron boron magnets, spinel type ferrites, hexagonal type ferrites, and garnet type ferrites. One or more types may be selected from magnetic powder materials such as ceramic materials such as.

The particle size of the magnetic particles 7 may be such that a desired magnetic force can be obtained and can be captured in the first void 8 in the same manner as the first resin particles 3, for example, the fiber 6. When the wire diameter is 7 μm, it may be 0.05 mm or more and 1 mm or less, preferably 0.1 mm or more and 0.5 mm or less.

Here, an example of a method for manufacturing the sound absorbing material 1 using magnetic force will be described. First, a mixture is prepared by mixing resin particles having different particle sizes such as polyurethane resin, lumps formed by entwining fibers 6, and magnetic particles 7 having a diameter sufficient to be captured in the voids formed in the lumps. (Mixture preparation step). Subsequently, the mixture is vibrated to capture the resin particles and the magnetic particles 7 having a small diameter in the mass to produce a magnetic mass (magnetic mass manufacturing step). Next, the magnetic lump is recovered by the magnetic force from the outside of the magnetic lump (magnetic lump recovery step). Further, the unrecovered mixture is sieved to remove small-diameter resin particles that are not captured, and the minimum particle size of the resin particles remaining in the sieve is set as a threshold, and large-diameter resin particles having a particle size equal to or larger than the threshold are recovered (large). Diameter particle recovery step). A composite in which a lump and a large-diameter resin particle are composited is filled in the package 5, and the large-diameter resin particles are dispersed and arranged in the package 5 to form a sound absorbing material 1 (composite filling step). ).

In this way, the small-diameter resin particles to be the first resin particles 3 are captured in the mass to form the fiber mass 2, the fiber mass 2 is recovered by magnetic force, and the separated large-diameter resin particles are second. When the composite is formed as the resin particles 4 of the above, the fibers 6 are entangled to form a lump, and the fiber lump 2 having the first resin particles 3 captured in the first void 8 inside the lump is formed. , A sound absorbing material 1 having a second resin particle 4 arranged in a second void 9 formed between a plurality of fiber lumps 2 and having a particle size larger than the particle size of the first resin particle 3. Can be manufactured. Further, by changing the magnetic force to recover the lumps in which the small-diameter resin particles and the magnetic particles 7 are captured, the sizes of the fiber lumps 2 can be easily made uniform, and the second resin having a desired size can be easily adjusted. Since the sound absorbing material 1 can be manufactured using the particles 4, stable sound absorbing performance with little variation can be obtained.

Further, for example, a part or all of recycled products such as an air conditioner and a refrigerator may be used as a material for constituting the sound absorbing material 1. An example of a method of recycling the refrigerator to manufacture the sound absorbing material 1 will be described.
First, for example, a housing provided with a heat insulating body containing a lump formed by disassembling an unnecessary refrigerator and entwining a resin such as polyurethane resin, a magnetic material such as iron, and fibers 6 such as glass wool. Separates from various parts such as compressors and door packings (separation process). Subsequently, the resin particles and magnetic particles 7 having different particle sizes and the lumps contained in the heat insulating body are recovered from the crushed powder obtained by crushing the housing and using wind power, magnetic force, or the like. After recovery, the resin particles and the magnetic particles 7 having different particle sizes may be further pulverized to obtain a desired size. Further, the lump may contain resin particles having a small diameter and magnetic particles 7. Then, the above-mentioned production is carried out using the lumps formed by entwining the fibers 6 obtained by recycling, the resin particles having different particle sizes, and the magnetic particles 7 having a diameter sufficient to be captured in the voids formed in the lumps. As in the example shown in the method, the sound absorbing material 1 can be produced from a recycled product through a mixture manufacturing step, a magnetic lump manufacturing step, a magnetic lump recovery step, a large-diameter particle recovery step, and a composite filling step.

Here, it is preferable that the recycled product is appropriately deodorized, washed, etc., and then subjected to treatment such as washing, removal of impurities, etc. in the step of further recovery. Further, after crushing the housing, the crushing powder is vibrated to recover a plurality of composites containing a magnetic lump containing small-diameter resin particles and magnetic particles 7 and a large-diameter resin particle in the lump. A plurality of composites can be filled in the package 5 and large-diameter resin particles can be dispersed and arranged in the package 5 to form the sound absorbing material 1. In this case, the sound absorbing performance of the manufactured sound absorbing material 1 may be inspected, and the sound absorbing material 1 having a desired sound absorbing performance may be selected.

The sound absorbing material 1 manufactured in this way can effectively utilize resources to obtain a sound absorbing material 1 having excellent sound absorbing performance in both a low frequency range and a high frequency range. Further, when the sound absorbing material 1 of the present invention having the magnetic particles 7 is recycled, the recycled product contains the magnetic particles, so that the sorting process can be facilitated.

In the first to fifth embodiments, the same type of material may be selected for the first resin particles 3 and the second resin particles 4, and for example, if a polyurethane resin is selected, a low frequency region may be selected. It is possible to obtain a sound absorbing material 1 having excellent sound absorbing performance in the high frequency range, stabilizing durability by reducing the material types of the sound absorbing material 1, simplifying the manufacturing process, and facilitating the utilization of resources in recycling. And even better.

Further, if the fibers 6 are imparted with hydrophobicity, the second voids 9 and the lumps between the plurality of lumps formed by the fibers 6 being entangled with each other due to the moisture mixed in the sound absorbing material 1 during the production of the sound absorbing material 1 It is possible to prevent the presence of water in the first void 8 inside, and it is easy to arrange the second resin particles 4 in the second void 9, and it is easy to capture the first resin particles 3 in the first void 8. Therefore, it is even better. Here, the fibers 6 or a part or the whole of the mass formed by the entanglement of the fibers 6 may have hydrophobicity.
Further, due to the hydrophobicity, when water adheres to the fiber 6 due to dew condensation or the like after the sound absorbing material 1 is manufactured, the fiber 6 gets wet and the bulk of the fiber mass 2 decreases, so that the volume of the first void 8 fluctuates. , And the deterioration of the sound absorbing performance of the sound absorbing material 1 due to the reflection of sound waves and the like can be suppressed. In the hydrophobic treatment, the fibers 6 and the lumps formed by entwining the fibers 6 are immersed in a water-repellent hydrophobic material such as mineral oil, synthetic oil, fluororesin, epoxy resin, and silicone resin. good. The hydrophobic material may be spray-sprayed to impart hydrophobicity to at least a part of the lumps formed by entwining the fibers 6 and the fibers 6 or the fiber lumps 2. By doing so, it is possible to obtain a sound absorbing material 1 having even better sound absorbing performance in both the low frequency range and the high frequency range.

Further, the sound absorbing material 1 can be directly filled in the noise part according to the application without filling the package 5. For example, the noise of the outdoor unit of the air conditioner may be filled between the noise source such as the compressor and the blower motor and the housing, and the engine may be used for the noise caused by the operation of the engine of the automobile. It may be partially or wholly covered and fixed.

In addition to the above, it is possible to freely combine each embodiment, modify any component of each embodiment, or omit any component of each embodiment.

1 sound absorbing material, 2 fiber lumps, 3 first resin particles, 4 second resin particles, 5 packages, 6 fibers, 7 magnetic particles, 8 first voids, 9 second voids.

Claims

A fiber mass in which one or more fibers are entangled to form a mass and have a first void and a first resin particle trapped in the first void inside the mass.
A sound absorbing material comprising a second resin particle arranged in a second void formed between the plurality of the fiber lumps and having a particle size larger than the particle size of the first resin particle.
The second resin particle is characterized in that it is selected from one or more of a polyurethane resin, a phenol resin, an epoxy resin, an acrylic resin, a polyester resin, a polyamide resin, and a melamine resin, according to claim 1. The described sound absorbing material.
The first resin particle is characterized in that it is selected from one or more of a polyurethane resin, a phenol resin, an epoxy resin, an acrylic resin, a polyester resin, a polyamide resin, and a melamine resin. The sound absorbing material according to claim 2.
The sound absorption according to any one of claims 1 to 3, wherein the ratio of the particle size of the second resin particles 4 to the particle size of the first resin particles is 2 or more. Material.
The sound absorbing material according to any one of claims 1 to 4, wherein the second resin particles have a particle size of 1 mm or more.
The sound absorbing material according to any one of claims 1 to 5, wherein the diameter of the fiber mass is 5 mm or more and 70 mm or less.
The sound absorbing material according to any one of claims 1 to 6, wherein the wire diameter of the fiber is 0.1 μm or more and 10 μm or less.
Any one of claims 1 to 7, wherein the bulk density of the filler in which the fiber mass and the second resin particles are combined is 30 kg / m 3 or more and 200 kg / m 3 or less. The sound absorbing material described in the section.
The sound absorbing material according to any one of claims 1 to 8, wherein the fiber mass and the second resin particles are filled in a package.
The sound absorbing material according to any one of claims 1 to 9, wherein magnetic particles are trapped in the first void of the fiber mass.
The sound absorbing material according to any one of claims 1 to 10, wherein the fiber, the lump, or the fiber lump has at least a part of hydrophobicity.
A mixture preparation step of mixing resin particles having different particle sizes, lumps formed by entanglement of fibers, and magnetic particles to prepare a mixture.
A magnetic mass manufacturing step of vibrating the mixture to capture the small-diameter resin particles and the magnetic particles among the resin particles having different particle sizes in the mass to produce a magnetic mass.
The magnetic lump recovery step of recovering the magnetic lump by magnetic force,
A large-diameter particle recovery step of sieving the unrecovered mixture to recover large-diameter resin particles having a particle size equal to or larger than a threshold value.
The package is provided with a composite packing step in which a composite in which the magnetic mass and the large-diameter resin particles are composited is filled in a package, and the large-diameter resin particles are dispersed and arranged in the package. Manufacturing method of sound absorbing material.
Further provided with a separation step of disassembling the recycled product having the housing provided with the heat insulating body and separating the housing.
The lumps formed by entwining the fibers are generated by the fibers contained in the heat insulating body collected by crushing the housing, and the resin particles having different particle sizes are made of the resin collected by crushing the housing. The method for producing a sound absorbing material according to claim 12, wherein the generated magnetic particles are generated from the magnetic material recovered by crushing the housing.