JP2001316961A - Sound-absorbing structural body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound-absorbing structural body having an excellent sound-absorbing capacity, especially a high flat sound-absorbing property from a low-frequency to a high-frequency. SOLUTION: This sound-absorbing structural body consists of a nonwoven fabric containing a glass fiber as a constituting fiber and having 500-4,000 g/m2 surface density, and a non-woven fabric containing a polyolefin high strength fiber of 0.1-12 dtex as a constituting fiber and having 50-500 g/cm2 surface density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing structure having high performance sound absorbing properties, and more particularly to a structure suitable for a sound absorbing wall material used for acoustic equipment.

[0002]

2. Description of the Related Art At present, high-performance sound absorbing and damping materials are required to have good sound insulation and sound absorbing properties. Conventionally used sound absorbing materials have been inorganic fiber (glass, etc.) nonwoven fabrics. Are used, and organic thermoplastic fibers (mainly, polyester fibers) and a sheath-core type (core;
Inventions such as high-melting point, sheath; low-melting point) fiber blend, thermoformed (heat-fused) non-woven fabric, etc. (JP-A-5-132841, JP-A-Hei 7)
-287581, JP-A-8-108810, etc.) have also been proposed.

[0003] However, the required level of the sound insulating performance and the sound absorbing performance of the sound absorbing material is increasing year by year. Particularly, the sound absorbing material used in the acoustic equipment has a high level from a low frequency range to a high frequency range and has a flat sound absorbing performance. Sex is required. Therefore, a glass fiber nonwoven fabric having high sound absorption performance mainly in a low frequency region to a high frequency region is used as a sound absorbing material. Flat sound absorption refers to a state in which sound absorption coefficients at １ ／ octave intervals are averaged and there is no extreme drop at a specific frequency.

[0004] However, glass fiber nonwoven fabrics have a high sound absorption performance from a low sound region to a high sound region, but have a large difference (drop) in sound absorption depending on the frequency, and it is difficult to obtain flat sound absorption performance at present. . Further, a higher level of sound absorption is required.

[0005]

SUMMARY OF THE INVENTION The present invention has been found to solve the above-mentioned problems, and relates to a sound absorbing material having a high sound absorbing property and a flat sound absorbing property.

[0006]

That is, the present invention relates to a non-woven fabric layer having an areal density of 500 to 4000 g / m ² using glass fiber as a constituent fiber and an areal density using a polyolefin high-strength fiber of 0.1 to 12 dtex as a constituent fiber. A sound absorbing structure comprising a nonwoven fabric layer of 50 to 500 g / m ² . And, specifically, the sound absorbing structure according to the above description, wherein a nonwoven fabric layer comprising a polyolefin high-strength fiber as a constituent fiber is laminated on an intermediate layer, and a nonwoven fabric layer comprising a glass fiber as a constituent fiber is laminated on both surfaces thereof. Wherein the polyolefin fiber is a high-strength polyethylene fiber, and an organic fiber nonwoven fabric and / or a woven or knitted fabric is laminated as a surface material on the outer surface side of the nonwoven fabric layer comprising a glass fiber as a constituent fiber, The sound absorbing structure according to the above, characterized by being formed by laminating an inorganic fiber nonwoven fabric and / or a woven or knitted fabric as a surface material on the outer surface side of a nonwoven fabric layer comprising glass fiber as a constituent fiber. The sound absorbing structure described above.

According to the present invention, the presence of a nonwoven fabric composed of polyolefin high-strength fibers in a glass nonwoven fabric not only improves the sound absorption performance from the low-frequency range to the high-frequency range, but also provides a flat sound absorption performance. Is understood, which has led to the present invention.

Note that the definition of the bass region to the treble region here is approximately 200 H, which can be measured by the reverberation room method sound absorption evaluation.
It means from z to 4000 Hz.

The definition of the high-strength polyolefin fiber herein means a fiber having a strength of 10 g / dtex or more and an elastic modulus of 50 g / dtex or more, and preferably 500 g / dtex or more. It is considered that the use of the polyolefin high-strength fiber in the nonwoven fabric tends to increase the vibration absorption performance due to high strength and high elasticity. This is because the sound converted to vibration by the glass non-woven fabric has a high absorption capacity (particularly in the low frequency region), and the vibration energy (power) of the sound
Can be absorbed more, and as a result, it is considered that the sound absorption is improved.

[0010] Further, by providing a nonwoven fabric composed of polyolefin high-strength fibers between two glass nonwoven fabrics, a flat sound absorbing property can be obtained. This is considered to be because the above-described configuration uniformly increases the sound absorbing property, and fills the sound absorbing valley (low) portion generated in the conventional nonwoven fabric composed only of glass fibers. . Further, the glass fiber nonwoven fabric has a high sound absorbing performance from a low sound region to a high sound region, but actually has a lower sound absorbing property in a low frequency region than in a medium high frequency region. However, by adopting the above configuration, the non-woven fabric having a flat sound absorbing property can be obtained by improving the sound absorbing property in a low frequency region.

[0011] Next, the reason why the presence of a non-woven fabric composed of polyolefin high-strength fibers between two glass non-woven fabrics increases the sound absorption to the maximum is described. The low-frequency sound penetrated into the glass non-woven fabric is converted into low-frequency vibration because it has high performance in reducing the vibration transmissibility in the region, and is absorbed by the polyolefin high-strength fiber non-woven fabric, resulting in high sound absorption. it is conceivable that. Furthermore, by sandwiching the polyolefin high-strength fiber nonwoven fabric, a multilayer (three-layer) structure is obtained, and the sound absorption by the multilayer structure is obtained, so that it is considered that the overall sound absorption is also improved. However, even if the polyolefin high-strength fiber non-woven fabric is simply placed on the surface of one glass non-woven fabric, the above sound-absorbing effect can be sufficiently obtained. When it is not possible to make the nonwoven fabric thus prepared exist, the polyolefin high-strength fiber nonwoven fabric may be installed on the surface of the glass nonwoven fabric.

The glass fiber nonwoven fabric has a surface density of 5%.
There is no particular limitation as long as it is in the range of 00 to 2000 g / m ² , and any form may be used. Further, a glass fiber non-woven fabric impregnated with a resin may be used without any problem. Organic fibers and inorganic fibers may be mixed to some extent without any problem. However, the density is more desirably 0.01 to 0.1 g / m ³ from the viewpoint of handleability and shape retention. Although there is no particular limitation on the fiber diameter, it is 0.1-1.
If it is in the range of 0 μm, there is no particular problem.

In addition, the structure is made of high-strength polyolefin fiber.
About the composition of the formed nonwoven fabric, 0.1 to 12 dtex
Area density 50-500g including polyethylene high strength fiber
/ M ^TwoThe non-woven fabric is not particularly limited. However
Since polyethylene fiber has a low melting point of about 120 ° C,
It is more desirable to use a needle punched nonwoven fabric. this
When performing thermoforming at temperatures above the melting point, polyethylene
Since the fibers adhere to each other, the number of restraint points increases and there is sound vibration.
This is because it is difficult to effectively absorb. In addition, polyolefin high strength
There is no particular limitation on the type of force fiber,
It is more preferable to use a len high-strength fiber.

Next, regarding the skin, the material may be either organic or inorganic fiber. Also, the form may be any of non-woven fabric, woven fabric and knitted fabric.
However, by installing it on the front surface side of the glass nonwoven fabric, a certain level of sound absorbing property improving effect is exhibited from the low frequency region to the high frequency region.

[0015]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. (Example 1) Glass fiber nonwoven fabric A having a surface density of 800 g / m ² and a thickness of 25 mm, a surface density of 1600 g / m ² and a thickness of 50
mm between glass fiber nonwoven fabrics B of 200 mm /
m ^2, and an evaluation sample material was placed high tenacity polyethylene nonwoven C of thickness 3 mm.

(Example 2) Glass fiber nonwoven fabric A having an area density of 800 g / m ² and a thickness of 25 mm and an area density of 1600 g / m ^2
2. Surface density 2 between 50 mm thick glass fiber nonwoven fabric B
A high-strength polyethylene nonwoven fabric C having a thickness of 00 g / m ² and a thickness of 3 mm was provided. Further, a polyester woven fabric D having an area density of 200 g / m ² was placed on the surface of the glass fiber nonwoven fabric A, and used as an evaluation sample. (Example 3) Glass fiber nonwoven fabric A having an area density of 800 g / m ² and a thickness of 25 mm, an area density of 1600 g / m ² and a thickness of 50
mm between glass fiber nonwoven fabrics B of 200 mm /
A high-strength polyethylene nonwoven fabric C having a thickness of ² mm and a thickness of 3 mm was provided. Further, a surface density of 20
A glass fiber woven fabric E of 0 g / m ² was set as an evaluation sample.

Comparative Example 1 A glass fiber nonwoven fabric D having an area density of 2400 g / m ² and a thickness of 75 mm was used as an evaluation sample.

(Evaluation method) Evaluation was made based on the sound absorption coefficient (the reverberation chamber method;
(According to JIS A 1409).
Table 1 shows the evaluation results of the sound absorbing properties.

[0019]

[Table 1]

As shown in Table 1, in each of the embodiments, a flat sound absorbing property such as drawing a gentle curve is obtained.
In the case of Comparative Example 1, although there is a frequency region having a better sound absorbing property than that of the working example, there is much variation throughout, and a flat sound absorbing property cannot be obtained.

[0021]

According to the present invention, it is possible to provide a sound-absorbing structure having excellent sound-absorbing performance, especially flat and high sound-absorbing properties from low frequencies to high frequencies.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G10K 11/162 D06M 17/00 M G10K 11/16 A F term (Reference) 4F100 AG00A AG00C AH00D AK03B AK04B BA02 BA03 BA04 BA06 BA10A BA10C BA10D BA13 BA26 DG01A DG01B DG01C DG01D DG12D DG13D DG15A DG15B DG15C DG15D GB08 JA13A JA13B JA13C JH01 JK01B YY00A YY00B YY00C 4L03 AA00 AA00 AA04 AA01 AA00

Claims (5)

[Claims] 1. An areal density of 500 comprising glass fiber as a constituent fiber.
A surface density of 50 to 4000 g / m ^{2 and} a nonwoven fabric layer of 0.1 to 12 dtex as a constituent fiber.
A sound absorbing structure comprising a nonwoven fabric layer of 500 g / m ² . 2. The sound-absorbing structure according to claim 1, wherein a nonwoven fabric layer composed of high-strength polyolefin fibers is formed on the intermediate layer, and a nonwoven fabric layer composed of glass fibers is laminated on both sides of the intermediate layer. body. 3. The sound absorbing structure according to claim 1, wherein the polyolefin fiber is a high-strength polyethylene fiber. 4. An organic fiber nonwoven fabric and / or a woven or knitted fabric as a surface material is laminated on the outer surface side of a nonwoven fabric layer comprising glass fibers as a constituent fiber. Sound absorbing structure. 5. The nonwoven fabric layer comprising glass fiber as a constituent fiber, an inorganic fiber nonwoven fabric and / or a woven or knitted fabric is laminated as a surface material on the outer surface side. Sound absorbing structure.