JP2001222285A - Fibrous sound absorbing body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the weight after mounting and man-hours for mounting by preventing the bending of a sound absorbing body. SOLUTION: A fiber molding 1 is formed to a planar form of a prescribed size and the front surface or inside of this fiber molding 1 is provided with a surface or net-like reinforcing material 2, by which the bending of the fiber molding 1 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-based sound-absorbing material used in buildings, civil engineering materials, railroads, roads, airports, various stadiums, amusement facilities and the like where particularly noise suppression is required.

[0002]

2. Description of the Related Art Conventionally, a fiber-based sound-absorbing material having sound-absorbing performance has been mounted on the backside of a road surface such as an elevated railway or road. In this case, the fibrous sound absorbing material having a predetermined size and formed in a plate shape has insufficient rigidity and is bent, so a flat bar is provided in a frame for mounting the sound absorbing material, or the sound absorbing material is covered with a perforated plate. To prevent the sound absorbing material from falling.

As described above, if a sound absorbing material is attached to the backside of an elevated road surface and left for a long period of time, the sound absorbing material will bend due to its own weight or external force such as wind or vibration. At this time, a dimensional change in the air layer behind the sound absorbing material and the frame and a change in the shape of the end of the sound absorbing material occur. Such deformation of the sound absorbing material increases with time and does not return to its original state.

Therefore, a louver or the like made of punched metal is used, and a method of setting a sound absorbing material on the louver has been adopted. However, the overall weight of the sound absorbing material provided on the backside of the elevated road surface and the louvers for preventing the deformation of the sound absorbing material has been increased, the man-hour for mounting the sound absorbing material has been increased, and the cost has been increased.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fiber-based sound absorbing material which prevents the sound absorbing material from bending and does not increase the weight after mounting or increase the number of mounting steps.

[0006]

In order to achieve the above-mentioned object, the present invention is to form a fiber molded body into a plate having a predetermined size, and to form a planar or net-like surface on or inside the fiber molded body. A reinforcing material is provided to prevent the fiber molded body from bending.

[0007]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

In the embodiment shown in FIG. 1, a fiber molded body 1 is formed in a plate shape having a predetermined size, and a planar or net-like reinforcing material 2 is provided on the surface of the fiber molded body 1 to form the fiber molded body 1. The following is a diagram for preventing deflection. FIG. 2 shows a wire net or a resin net used as the reinforcing member 2. In order to manufacture such a fiber-based sound absorbing material, a method as shown in FIGS. 3 to 5 can be employed. That is, hot melt powder was sprayed on the surface of the formed fiber molded body 1, and then the reinforcing material 2 was superimposed on the hot melt spray layer 3 as shown in FIG. 4, and then heated as shown in FIG. A material obtained by superposing the reinforcing material 2 on the surface of the fiber molded body 1 is fed between a pair of belt conveyors 10. Then, it is heated and pressurized while being transferred between these conveyors 10 and the reinforcing material 2
Is integrated with the fiber molded body 1.

[0009] The above-mentioned fiber molded body 1 has a fiber distribution
The average appearance of short fibers with a heart of 30 denier or less
Density 0.01 to 0.15 g / cm^ThreeMolded into fiber aggregate
What is obtained can be suitably used. 30 denier or less
Use fine short fibers and keep the apparent density within the specified range.
To increase the airflow resistance inside the fiber molded body 1
The sound absorption characteristics are improved. If it's 30 denies
The use of fibers greater than or equal to
It is in a state, the ventilation resistance does not increase and the sound absorption characteristics are inferior
become. So, let's make this apparently dense
If you try to improve sound absorption with
Radiation becomes easier, and conversely, the sound absorption performance decreases. In addition, look
Increasing the hanging density is disadvantageous for weight reduction.
You. From these viewpoints, the upper limit of the apparent density is 0.15 g.
/ Cm^ThreeMust be set to On the other hand, 30 denier or less
Even if the lower thin fiber is used, the apparent density is 0.01 g / c.
m ^ThreeBelow, ventilation resistance does not increase and expects sound absorption
And the soundproofing performance becomes insufficient. Use
The short fiber used is basically 30 denier or less,
15 denier or less to achieve sound absorption performance
It is desirable to use 1 to 8 denier short fibers. Short
Examples of fiber materials include polyester and polypropylene.
Synthetic fibers such as ren, polyethylene, nylon, vinylon
In addition, natural fibers such as wool, cotton, and hemp can be used.
Wear. In addition, they were opened from fabrics using these fibers.
Short fibers can also be used. In this case, there is bitumen
Or similar material by melt spinning or other methods.
In the form of fibers, this is 10% by weight or more in the short fibers described above.
Molding of fiber aggregates mixed or used alone
By using a product, a large sound insulation and sound absorption effect can be obtained.
Can be Bituminous similar materials include bituminous brittleness and temperature.
Dependency on resin, rubber, thermoplastic elastomer, etc.
Containing 30% by weight or more of bituminous material modified by
You. Such bituminous or similar materials are made into fibrous
Can be used to obtain a large sound insulation and sound absorption effect
Indicates that bituminous vibration damping (high damping)
Suppressed not only sound insulation and sound absorption, but also vibration
This is because the function can be obtained.

The fibrous molded article 1 contains a binder and has an apparent density of 0.025 g / cm ³ preformed in a flat plate.
It can also be obtained by laying the following short fiber aggregate (preliminary molded body) in a mold and subjecting it to heat compression molding so that the volume becomes 1/2 to 1/4. As such a preform, a polyester fiber which is hardened with a binder such as polyethylene fiber, low melting point polyester fiber or bituminous fiber can be used. When the fiber molded body 1 is obtained by compression molding the preformed body, if the compression ratio is less than 2, the air permeability becomes too large and the sound absorption is low,
If the compression ratio exceeds 4, an over-compressed portion occurs,
For the reasons described above, the soundproof performance becomes insufficient.

Further, there is a method in which the fibers which have been opened and separated are blown into a mold together with a gas (air), only this air is discharged from a large number of mesh holes, and only short fibers are filled in the mold to form. By adopting it, more uniform filling can be performed and the density distribution can be reduced. In order to solidify the thus obtained filler, a binder is required. As the binder, various materials such as a phenol resin which is heated and melted and solidified by reaction or a urethane-based adhesive which solidifies by steam injection are considered, but a binder having a fibrous form can be suitably used. As such a fibrous binder, a low-melting polyester fiber which is melted by heating or steam, or a polyethylene or polypropylene fiber which is melted by heating and solidified by cooling can be used. In this way, short fibers as a raw material are blown into the mold together with the fibrous binder, and further hot air is blown to melt the binder and bond the short fibers, thereby forming a soft, lightweight, and desired-shaped fiber. The body 1 can be obtained. Such a fiber molded body 1 has high dimensional accuracy and excellent soundproofing performance.

Further, as the fiber molded body 1, one as shown in FIG. 6 can be used. That is, a layer formed by laminating a skin layer 1B made of another organic fiber non-woven fabric on one side of a core material layer 1A made of an organic fiber non-woven fabric is used as a fiber molded product 1.
Can also be used. The core layer 1A is formed by blending 35% of polyester low-melting fiber having a fiber diameter of 3 denier and 65% of polyester fiber having a fiber diameter of 6 denier, forming a sheet after opening these fibers (this is referred to as a web).
Then, the web is heat-treated at 150 ° C. for 1 minute to melt the polyester low-melting fiber and bond the web fibers to each other. Apparent density of the organic fiber nonwoven fabric forming the core layer 1A is, 0.01 g / cm ³ or higher, preferably 0.02 to 0.5 g / cm ^3, more preferably 0.0
³ to 0.4 g / cm ³ . This core material layer 1A was manufactured by a method of opening and heat-treating. As a processing method after forming the web, in addition to the method of opening and heat-treating, an adhesive type,
There is a mechanical coupling type (fiber locker type), and a processing method other than the above-described method of opening and heat-treating is also possible. As the organic fiber, a wide range of raw material fibers such as rayon, acetate, nylon, polypropylene, tetron, and vinylon can be used in addition to polyester. The above-mentioned method is a processing method in which fibers of the web are bonded to each other after the web is formed by a dry method.

The skin layer 1B shown in FIG.
0.05 g / cm ³ or more, preferably 0.2 to 1.2
g / cm ^3, more preferably from 0.3 to 1 g / cm ^3, in which the organic fiber nonwoven fabric formed from long fibers and water repellent treatment. This nonwoven fabric is manufactured by a spun bond method. The same organic fibers as those used in the core layer 1A are used. By making the skin layer 1B denser than the core material layer 1A, a highly rigid fiber molded body 1 can be obtained.

In order to apply a water-repellent treatment to the organic fiber nonwoven fabric made of long fibers forming the skin layer 1B shown in FIG. 6, a fluorine-based processing agent is diluted with water to form a 2 to 10% solution. The organic fiber nonwoven fabric is immersed, and then the nonwoven fabric is dried and then cured. Alternatively, an aqueous solution containing 2 to 30% of an acrylic emulsion may be prepared before the fluorine processing and dried.

As shown in FIG. 7, the skin layer 1B made of the organic fiber nonwoven fabric 12 subjected to the water-repellent treatment is provided on one surface of the web 13 at the time of manufacturing the core material layer 1A.
Paste with. The hot melt 11 cools and solidifies to form an adhesive layer 1C shown in FIG. In FIG. 7, reference numeral 14 denotes a heater device.
Hot melt 11 is melted at the location of the cooling roll 15 and the melted hot melt 11 is solidified at the location of the cooling roll 15 to form the web 1
The nonwoven fabric 12 is stuck on 3. By cutting the sheet material after passing through the cooling roll 15 into an appropriate size,
The fiber molded body 1 shown in FIG. 6 can be obtained. In this case, the apparent density of the core material layer 1A is 0.01 g / cm ³ or more, the apparent density of the skin layer 1B is 0.05 g / cm ³ or more, and the gap between the fibers becomes 200μm or less. When the gap between the fibers of the skin layer 1B exceeds 200 μm, water droplets easily enter. Even if it is 200 μm or less, it does not hinder noise input. Preferably 0.1 μm to 100
μm.

As the adhesive layer 1C, in addition to the hot melt 11, 5 to 60% by weight of a polyester low melting point fiber in a polyester fiber having a melting point of 200 ° C. or more, preferably 250 ° C.
The web 13 that contains is preferably used. A web 13 serving as the adhesive layer 1C between the core layer 1A and the skin layer 1B
With a compression press at 180 ° C.
The fiber molded body 1 can also be obtained by heating for 5 minutes to melt and integrate the low melting point fibers. The low melting point fiber used as the adhesive layer 1C melts at 80 to 180 ° C, particularly 90 to 170 ° C.
Polyester fibers at 0 ° C. can be suitably used. Instead of a normal adhesive, an adhesive layer 1C containing 60 to 100% by weight of a low-melting fiber is provided between the skin layer 1B and the core layer 1A, and the skin layer 1B is heated and pressed to form the core layer 1A. , It is possible to form the molded body 1 substantially composed of only fibers, and in this respect, the working environment, recyclability, and cost are excellent.

The organic fiber nonwoven fabric 12 forming the core layer 1A and the skin layer 1B is a fiber having a melting point of 200 ° C. or more, and a fiber diameter of 15 denier or less, preferably 0.5 to 6 denier, more preferably 1 to 4 denier. Forming from denier fibers is preferred in terms of performance and cost.

The skin layer 1B can be laminated not only on one side of the core layer 1A but also on both sides. The skin layers 1B laminated on both sides of the core material layer 1A may have different raw fibers or different apparent densities between those on one surface and those on the other surface. The reinforcing material 2 can be provided on the surface or between the core material layer 1A and the skin layer 1B.

The embodiment shown in FIG. 8 shows a spunbond spunbond nonwoven fabric (Toyobo Dynac G)
P025) 4 and an organic fiber non-woven fabric 5 produced by a spun bond method is further superposed thereon, and a hot melt powder (Nitto Bo 7211, EVA, 6
0 g / m ² ) to form a sprinkling layer 3, and a reinforcing material 2 made of aluminum expanded or expanded iron or SUS was overlaid. These laminates were heated at a temperature of 13
Heating and pressurization was performed at 0 ° C. for 1 minute. The pressure at this time is 3.5k
gf / cm ² . The size of the fibrous sound absorbing material obtained here was 1 m × 2 m and the thickness was 40 mm. Also, instead of aluminum expand, an aluminum punched plate (thickness 1.
5 mm, a hole φ8, and a hole-to-hole pitch of 10 mm) may be used.

In another embodiment shown in FIG.
Urethane binder (Nittobo VA2515,2)
4 g / m ² ) 6 were superimposed, and a reinforcing material 2 made of aluminum expanded was superimposed thereon. Further reinforcing material 2
Was provided with a urethane binder 4 ', and the fiber molded body 1 was overlaid thereon. This laminate was heated and pressed in a mold at a temperature of 150 ° C. for 1 minute. Alternatively, they were joined by heat lamination (130 to 150 ° C. × 1 minute). The pressure applied at this time was 3.5 kgf / cm ² .

In the embodiment shown in FIG. 10, a spider web spunbonded nonwoven fabric 4 is superimposed on a water-repellent nonwoven fabric 5, and a cold gauze (Toyobo ES1000) 7 is further provided on the spunbonded nonwoven fabric 4. The same thing as the spider web spunbonded nonwoven fabric 4 was provided, and the fiber molded body 1 was further provided. This laminate was heated and pressed in a mold at a temperature of 140 ° C. for 1 minute. Alternatively, they were joined by heat lamination. The pressurizing pressure at this time was 3.57 kgf / cm ² . The cold gauze 7 in FIG. 10 corresponds to the reinforcing material 2.

The reinforcing member 2 can be attached to the fiber molded body 1 by using not only adhesive means but also fasteners or rivets.

[0023]

As described above, according to the present invention, since a planar or net-like reinforcing material is provided on the surface or inside of the fiber molded body, deflection of the fiber molded body is prevented, and in particular, an elevated railway. When installed on the back side of a road or an elevated road, it is possible to prevent an increase in weight, increase the number of mounting steps, and to prevent deformation over a long period of time. Further, since the weight of the fibrous sound absorbing material itself is light, it is easy to handle and the workability is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention.

FIG. 2 is a perspective view of a reinforcing member used in FIG.

FIG. 3 is a view showing a state in which hot melt powder is sprayed on a fiber molded body.

FIG. 4 is an explanatory diagram in which a reinforcing material is superimposed on a spray layer on which hot melt powder is sprayed.

FIG. 5 is an explanatory view showing an example of a means for heating and pressing the laminate shown in FIG. 4;

FIG. 6 is a sectional view showing another example of a fiber molded body.

FIG. 7 is an explanatory view showing a production example of a fiber molded body as shown in FIG.

FIG. 8 is a sectional view showing another embodiment.

FIG. 9 is a sectional view showing still another embodiment.

FIG. 10 is a sectional view showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fiber molding 2 Reinforcement

Claims (8)

[Claims] An object of the present invention is to form a fibrous formed body into a plate having a predetermined size and to provide a planar or net-like reinforcing material on or in the surface of the fibrous formed body to prevent deflection of the fibrous formed body. Characteristic fiber-based sound absorbing material. 2. The fibrous sound absorbing material according to claim 1, wherein a metal net, a resin net or a woven fabric is used as the reinforcing material. 3. An organic fiber nonwoven fabric different from the core material layer is subjected to a water-repellent treatment on one or both surfaces of a core material layer made of an organic fiber nonwoven fabric with a fiber material, so that a gap between fibers is 200 μm or less. The fibrous sound-absorbing material according to claim 1 or 2, wherein the fibrous sound-absorbing material is formed from a laminate of skin layers. 4. An organic fiber non-woven fabric comprising an organic fiber non-woven fabric, wherein the apparent density of the organic fiber non-woven fabric forming the core material layer is 0.01 g / cm ³ or more and which is formed from short fibers having a length of 200 mm or less, forming the skin layer. 0.05g / cm apparent density
The fibrous sound absorbing material according to claim ^{3, wherein the} number is ³ or more. 5. The fibrous sound absorbing material according to claim 3, wherein an acrylic emulsion is added before the water repellent treatment. 6. The fibrous sound-absorbing material according to claim 3, wherein a water-repellent nonwoven fabric serving as a skin layer during the production of the core material layer is bonded by hot melt. 7. The fibrous sound-absorbing material according to claim 1, wherein the reinforcing material is bonded to the fiber molded body by hot melt. 8. The fiber molding according to claim 1, wherein the reinforcing member is provided on the fiber molded body by fasteners or rivets.
The fiber-based sound-absorbing material according to any one of the above.