JP2000144565A - Nonwoven fabric and its production, production device used for the production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonwoven fabric having a good sound-absorbing characteristic and suitable for vehicle uses by forming a three-dimensional structure which comprises a staple fiber composition containing thermally fusible fibers and in which the mutual contact portions of the fibers are partially heat-fused. SOLUTION: The nonwoven fabric is obtained by preliminarily opening staple fibers comprising at least both sheath-core type thermally fusible fibers and <=1.5 denier fibers, carrying the obtained tuft T into a charging duct 1 with air, once staying the carried tuft 1 in a reserve trunk 4, adjusting the flow of air to constantly maintain a charged height or a charged density, sequentially feeding the tuft T to an opener roller 6 through a feed roller 5, further homogenizing the tuft T, feeding the homogenized tuft T on a feed trunk 7, uniformly compressing the web W in the feed trunk 7 in the lateral direction by the flow of air, carrying the web W on a carrying conveyer 10 with a delivery roller 9, guiding the web W to a heat setter and subsequently subjected the web to a thermal fusion treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a nonwoven fabric obtained by entanglement of short fibers,
More particularly, the present invention relates to a nonwoven fabric in which the directionality of constituent short fibers has three-dimensional randomness, a method for manufacturing the same, and a manufacturing apparatus.

[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, if the fineness is less than 1.5 denier, it will sink into the needle cloth of the card machine. It becomes a nep, and extremely deteriorates the quality and decreases the 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 nonwoven fabric having a uniform and three-dimensionally random fiber orientation, a manufacturing method capable of easily manufacturing the nonwoven fabric, and a manufacturing method used in the manufacturing method are provided for the purpose of improving sound absorption characteristics and the like. It is to provide a device.

[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 three-dimensional structure of a nonwoven fabric made of short fibers, wherein the fibers substantially adhere at a part of a contact portion between the fibers, and the fibers have a three-dimensional structure. Characterized in that they are arranged in random directions in at least two planes of the nonwoven fabric. The invention according to claim 2 is a three-dimensional structure of a nonwoven fabric composed of at least two or more kinds of fibers, one of the constituent fibers containing a component having a melting point lower than the melting point of the other fibers. Wherein the low melting point component substantially adheres to 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 three-dimensional structure. Nonwoven fabric. Further, the invention according to claim 3 is characterized in that the constituent fibers are a core-sheath type heat fusion type fiber,
The nonwoven fabric according to claim 1 or 2, wherein the nonwoven fabric comprises fibers of 1.5 denier or less. Claim 4
According to the invention according to the invention, short fibers are pre-spread by a pre-spreading machine, and then the short fibers are piled up by using an air stream so as to be automatically piled up in a portion where the vertical pile level is low, and then inter-fibers are separated. Is a nonwoven fabric manufactured by substantially bonding a part of the contact portion of the nonwoven fabric. These nonwovens are
It is manufactured by the manufacturing method according to claim 5. That is, the short fiber is preliminarily opened by the preparatory opening machine,
Then, the non-woven fabric is manufactured by depositing the short fibers by automatically stacking them in a portion having a low vertical deposition level using an air flow, and then substantially bonding a part of a contact portion between the fibers. It is manufactured by a manufacturing method. This nonwoven fabric manufacturing method is manufactured by the manufacturing apparatus according to claim 6. That is, the short fibers are pre-spread by a pre-spreading machine, and then the short fibers are deposited by automatically stacking them in a portion where the vertical deposition level is low using an air flow, and then the contact portions between the fibers are contacted. Is manufactured by a nonwoven fabric manufacturing apparatus which manufactures by substantially bonding a part of the nonwoven fabric.

BEST MODE FOR CARRYING OUT THE INVENTION

The nonwoven fabric of the present invention will be described below.
Note that this embodiment is merely an example of the embodiment,
The present invention is not limited to this embodiment.

The nonwoven fabric according to the present invention is mainly composed of polyester-based short fibers, and substantially adheres at a part of the contact portion between the fibers, and the constituent fibers are at least 2% of the nonwoven fabric structure. A nonwoven fabric characterized by being arranged in a random direction within a plane.

The fibers constituting the nonwoven fabric include, for example, polyester fibers (fineness 6.0 denier, fiber length 51 mm) having a side-by-side structure and exhibiting self-crimping properties.
Among ultrafine polyester fibers (fine denier: 0.5 denier, fiber length: 51 mm) referred to as fine denier, core-in-sheath type composite fibers, and the melting point of the fiber constituting the sheath portion is one of the fibers constituting the nonwoven fabric according to the present invention. Polyester with the lowest melting point (fineness 2.0 denier, fiber length 5
1 mm). If the fibers are limited to polyester, it is advantageous in that the fibers are re-melted when recycled.

The outer shape of the manufactured nonwoven fabric according to the present invention is a thin, substantially rectangular parallelepiped. The greatest feature of the nonwoven fabric 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.
That the fiber orientation on the surface is random (hereinafter,
It is called “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) for at least two sides of a non-woven fabric rectangular parallelepiped is set in a stereoscopic microscope, and this is set to an image processing apparatus (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 image processing command 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).

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[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.

Next, the results of the performance evaluation of the nonwoven fabric according to the present invention will be shown. The performance evaluation was a sound absorbing characteristic when this nonwoven fabric was used as a sound absorbing material.
000 Hz) and a static spring constant at 5 kgf. The results are shown in Table 4.

[0022]

[Table 4]

The sound absorbing properties and mechanical properties 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. The static spring constant at 5 kgf was measured by an automatic hardness tester according to JASO-M304. 300x300m which is a measurement sample
20 mm and a thickness of 50 mm
The thickness when a load of 0.5 kgf is applied by a 0 mm pressure plate is defined as the initial thickness. This is applied at a pressing speed of 50 mm / min from 0 to 6
Compress to 5%, and measure the static spring constant at 5 kgf. The lower the static spring constant, the lower the frequency range (500 to 10).
(00 Hz).

As is apparent from Table 4, there is a remarkable difference in the sound absorbing properties between the nonwoven fabric manufactured by the conventional card method and the nonwoven fabric according to the present invention. The first reason for expressing this difference is that ultra-fine fibers, which could not be applied to a carding machine with a conventional nonwoven fabric and could not be used as a constituent fiber of the nonwoven fabric, became fibers of a nonwoven fabric per unit volume. This is because the total surface area was increased. That is, sound absorption occurs when sound waves (waves of air molecules) enter the nonwoven fabric and come into contact with the surface of the fiber to convert sound energy into heat energy due to friction. For this reason, if the nonwoven fabric has 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 better the sound absorption characteristics. I do. Conventionally, an ultrafine fiber of about 0.5 denier, which has not been applied to a card machine, has exhibited such an effect.

The second reason is expressed by three-dimensional randomness that cannot be realized by a conventional nonwoven fabric. That is, by having three-dimensional randomness,
It is considered that the diffuse reflection of the propagated sound wave in the non-woven fabric was promoted, so that multiple reflection of the sound proceeded, and the friction between the fibers was more likely to occur, so that the sound absorbing characteristics were improved. It should be noted that JP-A-10-1
Japanese Patent No. 10370 describes a two-dimensional random manufactured by blow-molding after hanging on a card machine, which has an orientation in a fiber traveling direction in the card machine due to the characteristics of the card machine. The improvement in sound absorption characteristics is not so expected.

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 the propagation of the sound is not uniform in the entire fiber assembly, so that the sound absorption characteristics are improved as compared with the case of the two-dimensional random.

Next, a nonwoven fabric manufacturing apparatus of the present invention and a manufacturing method using the same will be described in detail.

(Nonwoven Fabric Manufacturing Apparatus) An example of the nonwoven fabric manufacturing apparatus according to the present invention is shown in FIG. 1 and FIG. As shown in the figure, the nonwoven fabric manufacturing apparatus includes an input duct (1) for inputting the pre-opened fibers, an exhaust duct for exhaust air (2), and an air outlet 1 in a reserve trunk (4).
(3) 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 the fibers and sending them to a feed trunk, a feed trunk (7) for sending short fibers by a fixed amount to a delivery roller (9), an air outlet 2 (8) in the feed trunk (7), and a web from the device. It comprises a delivery roller (9) for sending out (W), a fan for blowing each part of the apparatus, and a conveyor (10) for conveying 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 by mechanism.

<Input Duct> The input duct (1) is a hollow rectangular parallelepiped located above the apparatus and having an opening on 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 punched 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.

<Reserve Trunk> The reserve trunk (4) has a vertical cylindrical shape for storing the pre-opened fiber (taft), and a feed roller (5) is provided below the reserve trunk. 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, it is possible to reliably feed out a raw material having a high bulky property 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 or a rectangular hole having a large number of small diameters formed in a flat plate. 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) The nonwoven fabric according to the present invention is manufactured by depositing pre-spread short fibers in the vertical direction by using an air flow, and setting the direction after extrusion to horizontal. When binder fibers are mixed, heat treatment (hot air treatment, far-infrared ray treatment, wet heat treatment, etc.) is preferably performed as a post-process to heat-mold the nonwoven fabric. It is preferable that the fibers are substantially bonded at a part of the contact portion between the fibers by a mechanical method such as a punch.

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

<Preliminary Fiber Opening Step> The fibers (tufts) taken out of the raw cotton by the bale opener are gradually and finely and uniformly made uniform by the opener generally used in the blended cotton step and the like. 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, 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. When several webs (W) are stacked in this manner, nonwoven fabrics having different fiber 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.

[0050]

According to the first aspect of the present invention,
It is possible to provide a sound absorbing material having good sound absorbing properties and suitable for a vehicle or the like. Further, according to the second aspect of the present invention, it is possible to provide a nonwoven fabric which can be easily handled by melting a component having a melting point lower than that of other fibers. Claim 3
According to the invention, fibers having a density of 1.5 denier or less can improve sound absorbing properties, and provide a sound absorbing material having good sound absorbing properties and suitable for use in vehicles and the like. Further, according to the invention of claim 4, it is possible to provide a nonwoven fabric which does not require a card machine,
It is possible to provide a nonwoven fabric manufactured at a reduced manufacturing cost by omitting a step or the like. According to the fifth aspect of the present invention, since a card step is not required as compared with the conventional card manufacturing method, the step can be omitted, and there is an effect of reducing the manufacturing cost. Further, according to the invention of claim 6, it is possible to provide a non-woven fabric manufacturing apparatus which can omit steps and realize a reduction in manufacturing cost.

[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

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noboru Nananabe 1-2-2 Umeda, Kita-ku, Osaka, Osaka Kanebo Synthetic Fibers Co., Ltd. (72) Inventor Hiroshi Onoe 1-2, Umeda, Kita-ku, Osaka, Osaka -2 Kanebo Gosen Co., Ltd.

Claims (6)

[Claims] 1. A three-dimensional nonwoven fabric made of short fibers, which substantially adheres at a part of a contact portion between fibers,
A nonwoven fabric, wherein fibers are arranged in random directions within at least two planes of the three-dimensional structure. 2. A three-dimensional structure of a nonwoven fabric composed of at least two or more kinds of fibers, wherein one constituent fiber contains a component having a melting point lower than the melting points of other fibers,
A non-woven fabric characterized in that the low melting point component substantially adheres to a part of a contact portion between the fibers, and the fibers are arranged in a random direction within at least two surfaces of the three-dimensional structure. . 3. A fiber comprising core-sheath type heat fusion type fiber,
The nonwoven fabric according to claim 1 or 2, comprising fibers of 1.5 denier or less. 4. A pre-spreading machine for pre-spread short fibers by a pre-spreading machine.
It was then manufactured by depositing the short fibers in a manner that automatically stacks vertically into the lower deposition level using a stream of air and then substantially bonding some of the contacts between the fibers. Non-woven fabric. 5. A pre-spreader for short fibers by a pre-spreader,
Then, the non-woven fabric is manufactured by depositing the short fibers by automatically stacking vertically in a portion having a low deposition level using an air flow, and then substantially bonding a part of a contact portion between the fibers. Production method. 6. A pre-spreader for short fibers by a pre-spreader,
Then, the non-woven fabric is manufactured by depositing the short fibers by automatically stacking them in a portion having a low vertical deposition level using an air flow, and then substantially bonding a part of a contact portion between the fibers. manufacturing device.