JP2001228879A - Sound-absorbing material and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven fabric structure, having uniform and three- dimensionally random fiber orientability for the purpose of improving sound- absorbing characteristics, etc., a method for easily manufacturing this nonwoven fabric structure and an apparatus for manufacture used for this method for manufacture. SOLUTION: This sound-absorbing material is formed by imparting a porous film to one surface of the nonwoven fabric structure, which is a three- dimensional structure of the nonwoven fabric structure consisting of short fibers and in which the contact parts of the fibers with each other are substantially partly adhered and the fibers are arrayed in random directions within at least the two surfaces of the three-dimensional structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound-absorbing material in which a porous film is provided on one surface of a nonwoven fabric structure obtained by entanglement of short fibers, and more particularly to the direction of short fibers constituting the sound absorbing material. The present invention relates to a sound-absorbing material in which a porous film is provided on one surface of a nonwoven fabric structure having three-dimensional randomness and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, in producing a web used as a non-woven fabric, a carding machine used in a carding process is used to comb the fibers with a cylinder and a needle cloth while the fibers are parallelized to some extent. (Card method). Further, it has been manufactured by a method in which short fibers are scattered in the air and then collected in a wire mesh to form a sheet (air lay method). Further, as one form of use of these nonwoven fabrics, it is known that the nonwoven fabric is used for a sound absorbing material such as a sound insulating wall of a vehicle, a house, or a highway, and the smaller the fineness of the constituent fibers, the better the sound absorbing characteristics. .

Japanese Patent Application Laid-Open No. H10-110370 discloses that, in general, when a sound absorbing material is made of fiber, the sound absorbing material has a higher density, a thicker thickness, and a finer fineness of the constituent fibers, the better the sound absorbing characteristics. Further, by arranging the fiber array in a random direction in a plane parallel to the surface of the sound absorbing material, for example, a fiber is hanged on a card to form a web, and the web is laminated and obtained. It is described that the fibers exhibit superior sound absorbing properties as compared with fibers arranged in one direction.

[0004]

However, even if an attempt is made to produce a web using fine fibers as constituent fibers by the card method, the fineness is 1.7 dtex (1.
If it is less than 5 deniers, it will sink into the garment of the card machine or become a nep, resulting in extremely poor quality and reduced machine operation rate. Further, in the card machine, since the web is formed while combing as described above, the fibers are always arranged in a certain direction. Further, it is difficult to realize a laminated state having a sufficiently uniform thickness by the air lay method, and the sound absorption characteristics of the nonwoven fabric become uneven, which is not preferable in quality.

Further, Japanese Patent Application Laid-Open No. H10-110370 discloses that after blending constituent fibers, the blended fibers are further blended and spread with a card, and then blow-molded using an air flow to be parallel to the surface of the sound absorbing material. Although it is said that nonwoven fabrics arranged in random directions in the plane can be manufactured, again, the fiber arrangement is once arranged in one direction by the combing process in a card machine performed before blowing, so that the obtained nonwoven fabric is Fiber orientation does not have sufficient two-dimensional randomness. In addition, this manufacturing method has a drawback that the sound absorbing material is weak in peeling in the laminating direction because the sound absorbing material is laminated in a direction perpendicular to the surface by blow molding with an air flow.

Accordingly, in the present invention, a sound absorbing material having a porous film provided on one surface of a non-woven fabric having a uniform and three-dimensionally random fiber orientation is provided for the purpose of improving sound absorbing properties and the like, and a sound absorbing material therefor. An object of the present invention is to provide a manufacturing method capable of easily manufacturing a sound absorbing material.

[0007]

The nonwoven fabric of the present invention has the following structure to solve the above-mentioned problems.

[0008] That is, the invention according to claim 1 is a sound-absorbing material in which a film is attached to at least one surface of a three-dimensional structure of a nonwoven fabric made of short fibers. A sound absorbing material, wherein the fibers are substantially adhered to each other at a part of a contact portion between the fibers, and the fibers are arranged in a random direction in at least two surfaces of the three-dimensional structure. . The invention according to claim 2 is characterized in that the nonwoven fabric structure is composed of at least two or more fibers, and one of the constituent fibers contains a component having a melting point lower than the melting point of the other fibers, The sound-absorbing material according to claim 1, wherein the low-melting-point component substantially adheres to a part of the contact portion between the fibers.
Further, the invention according to claim 3 is the sound-absorbing material according to claim 1 or claim 2, wherein the fibers constituting the nonwoven fabric structure include a core-sheath type heat fusion type fiber and a fiber of 2 dtex or less. is there. The invention according to claim 4 is the sound-absorbing material according to any one of claims 1 to 3, wherein the film-like material is a porous film. The invention according to claim 5 is the sound-absorbing material according to any one of claims 1 to 4, wherein the film is a spunbond film, a flash-spun film, or a knitted fabric. The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the film is a spunbond film, a flash-spun film, or a knitted fabric having water repellency and / or weather resistance and / or flame retardancy. The described sound absorbing material. These sound absorbing materials are manufactured by the manufacturing method according to claim 7. That is, after pre-spreading the short fibers, and then depositing the short fibers in such a manner that they are automatically piled up in a vertically lower portion by a gas flow, a part of the contact portion between the fibers is substantially removed. A nonwoven fabric structure is produced by adhering to a nonwoven fabric, and a film is attached to at least one surface of the fibrous structure at the same time as or after the bonding step between fibers.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a nonwoven fabric structure which is a member of the sound absorbing material of the present invention will be described. Note that the present embodiment is merely an example of the embodiment, and the present invention is not limited to this embodiment.

[0010] The nonwoven fabric structure substantially adheres at a part of the contact portion between the fibers, and the constituent fibers are arranged in a random direction within at least two surfaces of the nonwoven fabric structure. Features.

It is preferable that the fiber material is a polyester material such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate (including a copolymer thereof). Mixing with other fibers is also possible, but if the fibers are limited to polyester-based ones, it is advantageous in that the fibers are re-melted when recycled.

The fibers constituting the nonwoven fabric include, for example, polyester fibers having a side-by-side structure and exhibiting self-crimping (fineness: 7 dtex, fiber length: 51 mm), and ultrafine polyester fibers called fine denier (fineness: 0.6 dtex, fiber Polyester (core length: 2.2 dtex, fineness: 2.2 dtex, length: 51 mm), which is a core-in-sheath type conjugate fiber in which the melting point of the fiber constituting the sheath portion is set to be the lowest among the fibers constituting the nonwoven fabric according to the present invention. Fiber length 51
mm).

The outer shape of the manufactured nonwoven fabric structure according to the present invention is a thin, substantially rectangular parallelepiped. The greatest feature of the nonwoven fabric structure according to the present invention is that the fiber orientation on at least two sides of the rectangular parallelepiped is random. This is manufactured by a manufacturing apparatus and a manufacturing method using the manufacturing apparatus described in detail below. Here, the orientation of the fibers on at least two surfaces thereof is random (hereinafter, referred to as “ "Three-dimensional randomness" will be described in detail.

The three-dimensional randomness refers to the directionality (also called orientation) of the fibers of each fiber constituting the nonwoven fabric.
Are not aligned in a certain direction. In order to quantify this randomness, three-dimensional randomness was defined by the following procedure.

First, a sample (about 2 cm × 2 cm) on at least two sides of a non-woven fabric rectangular parallelepiped is set on a stereoscopic microscope, and the image data is sent to an image processing device (an image analyzer V10 manufactured by Toyobo Co., Ltd.) at a magnification of about 40 times. Take in. Next, the image data of this original image is
A “binarization process” is performed by the method, and the fiber portion is divided into two, with a black portion and a background portion being a white region. Further, "thinning processing" is performed on the background portion (white area) to make the thickness uniform. The direction of this background is referred to as “filler diameter ratio (y / x
Ratio), and the average value (average value of about 10 data) is defined as a quantification of the three-dimensional randomness as an index indicating the directionality of the fiber of the nonwoven fabric itself.

The fillet diameter is one type of an image processing command for an image in the image processing apparatus, and performs the following processing. Each fiber constituting a nonwoven fabric in which the background portion (white area) in the image data is subjected to "thinning processing" and the thickness is made uniform, with the horizontal axis being the X axis and the vertical axis being the Y axis in the image processing apparatus. , The length of the projected horizontal diameter on the X axis, which is the horizontal axis, is defined as the fillet diameter X.
The length of the projection vertical diameter on the Y axis, which is also the vertical axis, is calculated as the fillet diameter Y. This calculation process is performed for each fiber, and the calculation result is defined as a fillet diameter ratio, and the fillet diameter ratio (y / x
Ratio). The fillet diameter ratio calculated in this way is 1.00 if the directionality is completely random.
When the directionality is inclined to the X axis, it becomes 1.00 or less. Conversely, when tilted to the Y axis, it becomes 1.00 or more. As described above, the fillet diameter ratio is determined for each fiber and the average value thereof is obtained, whereby the fillet ratio close to 1.00 has randomness. By performing this processing on at least two surfaces of the nonwoven fabric rectangular parallelepiped, if the fillet diameter ratio on each surface is close to 1.00, it can be said that three-dimensional random.

The results of the arithmetic processing are shown in Tables 2 and 3 for the nonwoven fabric according to the present invention (Examples 1 and 2) and the nonwoven fabric manufactured by the card method as a comparative example. The diameter ratio is shown (see Table 1 for production conditions such as fineness and fiber length of each nonwoven fabric).

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

As is clear from Tables 2 and 3, while the fillet diameter ratio of the nonwoven fabric according to the present invention is near 1.00, the nonwoven fabric manufactured by the card method is lower than 1.00. The difference is expressed. Therefore, that the fiber orientation degree in at least two planes of the nonwoven fabric is in the range of 0.95 to 1.05,
That is, it can be defined as having three-dimensional randomness.

The film-like material present on at least one surface of the non-woven structure having three-dimensional randomness may be bonded to the non-woven structure by heat or an adhesive, or may be bonded to the surface without bonding. You can just ride.

Examples of the film-like material include a uniform film, for example, a polyester film, a polyethylene film, and a polyvinylidene fluoride film. A porous membrane is also preferably used. From the viewpoint of recycling, the material of the porous membrane is preferably the same type as the nonwoven fabric structure, and a polyester spun bond is mainly used. However, a nonwoven fabric such as nylon, polyethylene, or polypropylene, a spun bond, a flash spun film, or a knitted fabric may be used.

A porous membrane, particularly a porous membrane having a ventilation resistance of 30% or more, is preferable because noise to be absorbed is hardly reflected and the sound absorbing effect is high. Further, considering that the sound absorbing material of the present invention is used outdoors for a long time, it has water repellency so that infiltrating rainwater does not enter the nonwoven fabric structure, and has low weather resistance with less deterioration by ultraviolet rays. It is also preferable to have it and to have flame retardancy.

Next, the results of the performance evaluation of the nonwoven fabric structure according to the present invention will be shown. The performance evaluation is a sound absorbing characteristic (10%) which is a sound absorbing property when this nonwoven fabric structure is used as a sound absorbing material.
(At 00 Hz and 2000 Hz) and the static spring constant at 49 N (5 kgf). The results are shown in Table 4.

[0026]

[Table 4]

The sound absorption characteristics and mechanical characteristics shown in Table 4 were measured as follows. Sound absorption coefficient is JIS-A1405
Incident sound absorption coefficient according to Bruel & Kjar
The measurement was performed by a two-microphone method using a multichannel analysis system Model 3550 (software: Model BZ5087, two-channel analysis software) manufactured by KK. The measurement range is 0 to 5000 Hz and N = 8. In addition, 49N (5
The static spring constant at the time of kgf) was measured by an automatic hardness tester according to JASO-M304. 300 which is a measurement sample
When a load of 0.5 kgf is applied to the upper surface of a sample having a thickness of 300 mm and a thickness of 50 mm using a pressing plate having a diameter of 200 mm, the initial thickness is defined as the initial thickness. Pressing speed 50mm / mi
The pressure is compressed to 0 to 65% with n, and the static spring constant at 5 kgf is measured at this time. The lower the static spring constant, the lower the frequency range (5
(00-1000 Hz).

As is apparent from Table 4, the non-woven fabric structure manufactured by the conventional card method and the non-woven fabric structure according to the present invention have a remarkable difference in sound absorption characteristics. The first reason for expressing this difference is that extra-fine fibers that could not be applied to a carding machine with a conventional nonwoven fabric structure and could not be used as constituent fibers of the nonwoven fabric structure, This is because the total surface area of the fibers per unit volume was increased. That is, sound absorption occurs when sound waves (waves of air molecules) enter the nonwoven fabric structure and come into contact with the surface of the fiber to convert sound energy into heat energy due to friction. Therefore, for nonwoven fabric structures with the same basis weight, the lower the average denier, the greater the number of fibers per unit volume, the greater the total surface area, the greater the conversion of sound waves to heat energy, and the greater the sound absorption properties. Is improved. Conventionally, an ultrafine fiber of about 2 dtex, which has not been applied to a card machine, exhibits such an effect.

The second reason is expressed by three-dimensional randomness that cannot be realized by a conventional nonwoven fabric structure. That is, it is considered that the three-dimensional randomness promotes the irregular reflection of the propagating sound wave in the nonwoven fabric structure, so that the multiple reflection of the sound proceeds, and the friction between the fibers is more likely to occur, so that the sound absorbing property is improved. In addition, what is called a two-dimensional random manufactured by blowing on a card machine described in Japanese Patent Application Laid-Open No. H10-110370 and then blow-molded is oriented in the direction of fiber advance in the card machine due to the characteristics of the card machine. Therefore, the improvement of the sound absorption characteristics is not expected as in the present invention.

Considering from a macro perspective, 3
If the dimension is random, the sound absorbing material as a whole has three-dimensional degrees of freedom. Such a point has a characteristic that the two-dimensional one does not propagate between layers with respect to the incidence of sound from the stacking direction (that is, if the sound incidence direction and the stacking direction are parallel to each other, the sound is lost and the sound absorption characteristics are reduced). In the case of three dimensions, it also has a characteristic that a desired sound absorption characteristic can be obtained regardless of the incident direction. In other words, it is considered that the direction of the reaction of the force received by sound propagation in the entire fiber assembly becomes non-uniform, so that the sound absorption characteristics are improved as compared with the case of two-dimensional random.

Next, an apparatus for manufacturing such a nonwoven fabric structure and a manufacturing method using the apparatus according to the present invention will be described in detail.

(Production Apparatus for Nonwoven Fabric Structure) An example of the nonwoven fabric production apparatus according to the present invention is shown in FIGS. As shown in the figure, the non-woven fabric manufacturing apparatus includes an input duct (1) for inputting the pre-opened fibers, an exhaust duct for exhaust air (2), an air outlet 1 (3) in a reserve trunk (4), A reserve trunk (4) for temporarily storing short fibers, a feed roller (5) for feeding short fibers from the reserve trunk (4) to an opener roller (6), an opener roller (6) for opening fibers and sending the fibers to the feed trunk; A feed trunk (7) for feeding a certain amount of fibers to a delivery roller (9),
Air outlet 2 in feed trunk (7)
(8) A delivery roller (9) for sending out the web (W) from the apparatus, a fan for blowing air to each part of the apparatus, and a transport conveyor (10) for transporting the web (W) to a subsequent process. The air flow is indicated by white arrows, and the fiber flow is indicated by black arrows.

The nonwoven fabric manufacturing apparatus will be described in detail for each mechanism.

<Input Duct> The input duct (1) is a hollow rectangular parallelepiped located above the apparatus and having an opening at the side or above. This is a section where fibers (tufts) preliminarily opened by an air flow are conveyed and introduced into the apparatus.

<Exhaust Duct> The exhaust duct (2) is a duct having an opening above and located in the vicinity of the input duct. The exhaust duct (2) controls the air flow used for transporting the fibers (tufts) when the apparatus is input. This is a duct that discharges to the outside of the device.

<Air Outlet 1> The air outlet 1 (3) is, for example, a punching metal or a rectangular perforated plate having a large number of small diameters formed in a flat plate, and has a structure in which the area of the opening can be adjusted. It is composed of things. Further, as a measure against fly waste, a filter or the like is provided before discharging to the outside of the apparatus.

<Reserved Trunk> The reserved trunk (4) has a vertical cylindrical shape for storing the pre-opened fiber (taft), and has a feed roller (5) at its lower part. Is provided. The fiber (taft) is temporarily stored in the reserve trunk (4), and is opened by the feed roller (5) and the opener roller (6).
Sent to.

<Feed Roller> The feed roller (5) is installed at the bottom of the reserve tank (4). A tooth wire is wound around the feed roller (5), the diameter thereof is large, and the length thereof is designed to be about 50 to 100 mm longer than the width of the web (W). With such a configuration, the raw material can be reliably sent out even to a raw material having a high bulkiness or a raw material having a long fiber length. Further, a motor capable of variable speed control, for example, an AC motor controlled by an inverter is connected to the feed roller (5) via a speed reducer. The speed control is based on the weight data of the web (W) from the weight checker for detecting the weight of the web (W) provided at the apparatus outlet or the sensor from the sensor for detecting the height of the web (W) provided at the apparatus outlet. Feedback control is performed based on the height data of the web (W) so that the weight and thickness of the web (W) always become set values. Further, the weight or thickness of the web (W) is controlled by performing feedback control based on pressure data measured by a pressure sensor provided in the feed trunk (7) so that the pressure in the feed trunk (7) is always constant. Is preferably set to a set value.

<Opener Roller> The opener roller (6) is installed near the lower part of the feed roller (5). The surface of the opener roller (6) is provided with several rows of spikes, the length of which is web (W)
Is designed to be about 50 to 100 mm longer than the width. Further, an electric motor rotating at a constant speed is connected to the opener roller (6) via a speed reducer. By the interaction between the opener roller (6) rotating at a constant speed and the feed roller (5) rotating at a variable speed, the fiber (tuft) is sufficiently opened and supplied to the feed trunk (7). .

<Feed Trunk> The feed trunk (7) has an opener roller (6) at its upper part, has a delivery roller (9) at its lower part, and has an air outlet 2 (8) at its middle part. It is a hollow rectangular parallelepiped. The fiber (tuft) supplied from the opener roller (6) is deposited in the feed trunk (7) by the manufacturing method described later so as to be uniform in the width direction, and becomes a web (W).

<Air Outlet 2> The air outlet 2 (8) is installed below the front and rear walls of the feed trunk (7), and is, for example, a punched metal having a small number of small holes formed in a flat plate or a rectangular hole. It is composed of a perforated plate or the like having a structure in which the area of the opening can be adjusted. These are provided over the entire width of the device.

<Delivery Roller> The delivery roller (9) is composed of, for example, two rollers opposed in the horizontal direction, and the length thereof is set to be about 50 to 100 mm longer than the width of the web (W). Designed for Furthermore, this delivery roller (9)
An electric motor rotating at a constant speed is connected via a speed reducer. The web (W) deposited in the feed trunk (7) is discharged out of the apparatus by two opposing delivery rollers (9).

<Transport Conveyor> Transport Conveyor (10)
Is, for example, a known belt conveyor for discharging a web (W) manufactured on an upper surface thereof horizontally out of the apparatus.

(Method of Manufacturing Nonwoven Fabric Structure) The nonwoven fabric structure according to the present invention is manufactured by depositing pre-spread short fibers in a vertical direction by using an air flow and setting the direction after extrusion to horizontal. is there. In addition, when the binder fiber is mixed, it is also preferable to perform a heat treatment (hot air treatment, far-infrared ray treatment, wet heat treatment, etc.) by a heat setter as a post-process, and heat-mold the nonwoven fabric. Preferably, the fibers are substantially adhered at a part of the contact portion between the fibers by a mechanical method such as needle punching.

The method for producing the nonwoven fabric will be described in detail in the order of steps.

<Preliminary Fiber Opening Step> The fiber (taft) taken out of the raw cotton by the bale opener is gradually and finely and uniformly made uniform by the opener generally used in the blended cotton step. These openers are provided with a beater, a cylinder, a spike roller, a tooth roller, and the like, and the roller mechanism and the like sufficiently open the short fiber composition. In order to produce a uniform web (W), the fibers (tufts) must be sufficiently opened, and the opening ratio is preferably 95% or more.

<Air Transport Step> The opened fiber (tuft) is transported from the opener to the input duct (1) of the manufacturing apparatus of the present invention by air.

<Reserve process> Input duct of device (1)
The fibers (tufts) supplied from the above are temporarily retained in the reserve trunk (4). In the reserve trunk (4), the air flow rate is controlled so as to adjust the flow rate of the air flowing into the reserve trunk (4) and to keep the filling height and the filling density in the reserve trunk (4) constant. That is, when the pressure in the trunk duct increases due to an increase in the level of the fiber (taft) or its density in the reserve trunk (4), this pressure fluctuation is detected and the air flow from the fan is reduced to reduce the amount of cotton feed. Let it. Conversely, when the pressure in the trunk duct decreases in accordance with the decrease in the level or density of the fiber (tuft), this pressure fluctuation is detected and the air flow from the fan is increased to increase the cotton supply. By performing such control, the operation is not stopped, and the filling level is kept constant. This air volume adjustment is performed by controlling the number of rotations of a fan provided at the center of the device, by changing the opening area of the air outlet 1 (3), and the like.

<Feeding Step> Next, the fiber (tuft)
Are fed into the feed trunk (7). In this case, a feed roller (5) is provided at the bottom of the reserve tank (4), and the web (W) is supplied to the opener roller (6) through the feed roller (5). As described above, the tooth wire is wound around the roller (5), and since the diameter thereof is set to be large, the raw material is reliably sent out even to a raw material having a high bulkiness or a long fiber length. be able to. The feed roller (5) detects the pressure in the feed trunk (7) and the speed is controlled. Further, since the speed of the opener roller (6) is constant and the circumference is provided with several rows of spikes, the fibers (tufts) are further homogenized and supplied to the feed trunk (7). . The web (W) in the feed trunk (7) is uniformly compressed in the width direction by the air flow generated by the fan inside the device, and the air flow is compressed by the air outlet 2. After (8), it is controlled to return to the fan. By doing so, the depth of the web (W) can be made constant along with the density of the web (W) deposited in the feed trunk (7). Since the web (W) in the feed trunk (7) is very small, it is not compressed under its own weight. Although the web (W) is compressed by the air flow from the fan, the speed of the feed roller (5) is controlled so that the compression pressure is constant. That is, the speed is reduced with an increase in the internal pressure of the feed trunk (7), that is, the supply amount of the fiber (tuft) is reduced, and the speed of the feed roller (5) is increased by a decrease in the internal pressure, that is, the supply amount of the fiber (tuft) is reduced. To raise. The fibers (tufts) discharged from the opener roller (6) are automatically directed by the airflow of the fan to a portion where the raw material level in the feed trunk (7) is low, that is, a portion where the flow resistance of the air is low. . This makes the feed trunk (7)
Raw material level differences can be eliminated over the entire width of the device within, ultimately resulting in high uniformity across the web (W). Also, as described above, the web (W)
Instead of controlling the thickness of the material by the change in air flow generated from the deviation in the width direction, the raw material that has progressed is weighed by an automatic weighing system such as a load cell system, and the raw material of an arbitrarily set weight is deposited based on the actual measurement value. Alternatively, the raw material having an arbitrarily set weight may be deposited while beating the fiber (taft) with a beater instead of an air flow.

<Discharge Step> The fibers (tufts) in the feed trunk (7) are sent out of the apparatus by the delivery roller (9). The discharged web (W) is transported to a subsequent process by the transport conveyor (10).

<Post Process 1> First, in the case of a web (W) containing heat-fused fibers, the web (W) is set on a heat setter. The heat setter is a known device, and has a structure in which a web (W) is passed through a device having a heat source by a conveyor or the like. Examples of the heat source include hot air obtained from combustion gas, high-temperature steam, far infrared rays, and the like. The temperature of the heat setting is a temperature at which the low melting point component is melted and the high melting point component is not melted. By the treatment in the subsequent step 1, the low melting point component is melted and substantially fused at the contact point with the high melting point component.

<Post-Process 2> In the case of a web (W) containing heat-fused fibers, the web (W) is set on a wet heat setter in addition to or in place of the above-mentioned processing method. This wet heat setter is a known device, and has a structure in which after the web (W) is charged into the inside of the steam pot, the steam pot is closed, the pressure is reduced, and then the high pressure and high temperature wet heat steam is sent. The temperature of the heat setting is a temperature at which the low melting point component is melted and the high melting point component is not melted. By the processing in the subsequent step 2, heat can be transferred to the inside of the web (W),
The low melting point component melts at every corner of the web (W), and substantially fuses at the contact point with the high melting point component. In such a method, even if several webs (W) conveyed by the conveyor (10) are stacked and processed, steam can penetrate into the inside thereof, and uniform heat setting can be performed. Further, when stacking several webs (W) in this way, nonwoven fabric structures having different densities in the thickness direction can be easily manufactured by stacking webs having different fiber densities. In any case, it is suitable for manufacturing a cushion material or the like.

<Post-Process 3> Regardless of whether the web (W) contains heat fusion or not, part of the contact portion between the fibers is mechanically performed as a post-process. Can be substantially adhered. For example, a plurality of needles (needle) are repeatedly pulled out and inserted many times in the vertical direction of the web (W) so that the fibers in the web (W) are entangled with each other and adhered at a contact portion of the fibers.

[0054]

According to the present invention, it is possible to provide a sound-absorbing material having good sound-absorbing characteristics and suitable for vehicles and the like.

[Brief description of the drawings]

FIG. 1 is a side view of an apparatus according to a manufacturing apparatus of the present invention.

FIG. 2 is a front view of an apparatus according to the manufacturing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input duct 2 Exhaust duct 3 Air outlet 1 4 Reserve trunk 5 Feed roller 6 Opener roller 7 Feed trunk 8 Air outlet 2 9 Delivery roller 10 Conveyor T Fiber (taft) W Web

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Noboru Wananabe 4-1 Kanebocho, Hofu City, Yamaguchi Prefecture Kanebo Goden Co., Ltd. F-term (reference) 2E001 DF04 GA23 GA28 GA81 HD11 4F100 AK01B AK04 AK19 AK42 BA02 BA03 BA06 BA10B BA13 DG03A DG12B DG13B DG15A DG15B DG18A DG20A DJ10B EC03A EC031 EC032 EH012 EH761 EJ421 EJ422 GB33 JA04A JB06B JH01 JJ07B JL09B 5D061 AA22 AA25 BB01 BB21

Claims (7)

[Claims] 1. A sound-absorbing material comprising a three-dimensional structure of a nonwoven fabric made of short fibers and a film-like material provided on at least one surface of the three-dimensional structure. Wherein the fibers are substantially adhered at a part of the three-dimensional structure, and the fibers are arranged in a random direction within at least two surfaces of the three-dimensional structure. 2. The nonwoven fabric structure is composed of at least two kinds of fibers, and one of the constituent fibers is
The sound-absorbing material according to claim 1, further comprising a component having a melting point lower than the melting point of the other fiber, wherein the low-melting component substantially adheres at a part of a contact portion between the fibers. 3. The sound-absorbing material according to claim 1, wherein the fibers constituting the nonwoven fabric structure include a core-sheath type heat-sealing type fiber and a fiber of 2 dtex or less. 4. The method according to claim 1, wherein the film is a porous film.
The sound absorbing material according to any one of the above. 5. The sound-absorbing material according to claim 1, wherein the film is a spunbond film, a flash-spun film, or a knitted fabric. 6. The sound-absorbing material according to claim 1, wherein the film is a spunbond film, a flash-spun film, or a knitted fabric having water repellency and / or weather resistance and / or flame retardancy. 7. The pre-spreading of the staple fibers, and then depositing the staple fibers by means of a gas stream in such a way that the staple fibers are automatically piled up in a vertically lower part, and then a part of the contact between the fibers A method for producing a sound-absorbing material in which a nonwoven fabric structure is produced by substantially adhering and a film-like material is attached to at least one surface of the fibrous structure at the same time as or after the step of adhering fibers.