JPS6330428B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a long-fiber nonwoven fabric manufacturing apparatus called the so-called spunbond method, which continuously performs spinning, drawing, and web formation. The present invention relates to an apparatus for producing long fiber nonwoven fabric that is stretched and laminated on a collection surface to form a web. A group of undrawn filaments from a spinneret are drawn by suction using an ejector and stacked on a collection surface,
In the production of a long fiber nonwoven fabric to be made into a web, in order to obtain a wide nonwoven fabric, the ejector must be moved in a direction perpendicular to the traveling direction of the web collection device, that is, in the width direction of the web, over the entire width of the nonwoven fabric to be produced. Generally, they are arranged in one or two or more rows. However, according to this, the traveling direction of the nonwoven fabric web to be manufactured, that is,
The disadvantage is that the strength of the nonwoven fabric in the longitudinal direction is greater than the strength of the nonwoven fabric in the lateral direction, that is, the width direction, and that only an anisotropic nonwoven fabric with different strength in both the longitudinal and lateral directions can be obtained. The reason for this is that when the air ejected from the ejector reaches the web collection surface, it collides with the air walls of other ejectors adjacent to each other laterally, instead of forming an isotropic circular pattern. The lateral spreading of the web collection surface is inhibited, which reduces the lateral spreading and entanglement of the filaments that the web should consist of, and the long axis is aligned in the web traveling direction such that more filaments are oriented in the longitudinal direction. This is to form a tangled oval pattern. To further elaborate on this point, when generally known ejectors are used to form a web by laminating filaments onto a web collection surface, the filaments are dispersed within the boundary area of the free air jet of the ejector jet. However, the distribution of filaments within the jet is not uniform, and the closer to the center, the more filaments accumulate. Therefore, when a large number of ejectors are arranged in parallel in the width direction, if the intervals between each ejector are widened to the extent that the boundary areas of their free air jets do not overlap so much, the air flow ejected from each ejector and , the interference force with the ejected airflow from the adjacent ejector is weakened, and the pattern of the ejected airflow drawn on the web collection surface is close to circular, but on the other hand, the filament deposition distribution within the pattern is not uniform. As a result, the nonwoven fabric is non-uniform with uneven fabric weight (fabric weight refers to the weight per unit area) in the width direction, so-called vertical stripes. Therefore, in order to obtain a nonwoven fabric with no unevenness over the entire width of the nonwoven fabric, the spacing between the ejectors arranged in the width direction should be close to each other until the boundary areas of the free air jets of each ejector overlap to a considerable extent. For example, it is necessary to
In the case of Publication No. 42-23998, the spacing between the ejectors is 1/1 of the size of the free air jet of the ejector.
I think about 3 is appropriate. However, in this case, as described above, the jet flow from each ejector hits the wall of the jet flow of the adjacent ejector, and the spread of the web in the width direction is inhibited at the web collection surface. An oval pattern with a long axis in the direction of travel is formed. The resulting web is such that the filaments are oriented at least in the longitudinal direction of the web (long axis direction of the pattern), and the spread and entanglement of the filaments in the lateral direction of the web (the short axis direction of the pattern) are different from each other. becomes anisotropic, with the strength in the vertical direction being larger than the strength in the lateral direction. In order to eliminate these drawbacks, it is necessary to create a non-woven fabric that does not have uneven surface area over the entire width of the non-woven fabric, even if each ejector is placed at a distance that prevents it from being affected by adjacent ejectors. It is necessary to widen the free air jet from each ejector and to keep the distribution of filaments within the jet as uniform as possible to the extent that it is possible to produce a There is a way to do it. In this method, since there is no influence from adjacent ejectors, the deposited filaments do not flow in the direction of travel of the web, and therefore the strength in the lateral direction is isotropic, close to the strength in the longitudinal direction. Depending on the conditions, a web that is stronger in the transverse direction may be obtained than in the longitudinal direction. However, in order to move the ejector across the entire width of the nonwoven fabric, a large-scale device is required, and when the manufacturing conditions, for example, the traveling speed of the collection surface is set to several meters per minute to several tens of meters per minute, the width In order to produce wide uniform webs, it becomes necessary to move the ejector transversely at considerable speeds. Furthermore, from the viewpoint of productivity, it is desirable to suction and deposit a large number of filaments using one ejector, so it is preferable to manufacture nonwoven fabrics by the so-called spunbond method, which involves continuous spinning, stretching, and web formation. However, there is a limit to the drawing and drawing capacity of the ejector itself, and moving the ejector means that the distance between the spinneret and the ejector is constantly changing, making it impossible to obtain a very stable spinning condition. In order to achieve this, it is possible to install several spinnerets in the width direction of the web and divide the web in the width direction to reduce the transverse movement of the ejector as much as possible, but this also causes the distance between the spinneret and the ejector to change. There is no change in the spinning process, and the spinning condition is very poor. As another means, a method has been proposed in which the airflow from the ejector and the filament group are moved transversely without moving the position of the ejector itself. For example, in Japanese Patent Publication No. 45-10779, a recess with an unwide wall is provided in the ejector injection port, and two air holes facing each other in the diametrical direction are provided on the wall of the recess. The transverse movement is caused by control air injected from the injection ports at alternating intervals. However, in this method, the control air flow for periodically changing the direction of the ejected air flow from the ejector is placed at a position close to the thread pulling part of the ejector, that is, at the upper part of the recess having a wide-end wall surface. Because the control air flow is located at When one side of the recess is completely closed and the other is open, the air flow inside the recess is completely pushed in one direction, and forms a so-called adhesion jet on the inner wall of the recess on the side that is pushed away. As a result, although the width of the web piled up is expanded by the transverse movement of the ejected air flow, the filament group itself does not spread in minute portions, and only a web with poor opening properties is formed. Furthermore, since a strong force is required to separate the flow of air that has adhered in this way and push it to the other side, if the control air that works for this purpose is slightly opened from the completely closed state, the air flow itself will be ,
It does not move away from the wall of the recess, and only when it approaches the fully open state does it move away and is pushed to the other side. As a result, the residence time of the air flow at the point of change of direction of the transverse movement, i.e. at the end of the web being deposited, is therefore reduced by depositing the filaments at the point of displacement of the transverse movement, i.e. in the center of the web being deposited. This results in a wide web with more filaments at the ends and fewer filaments at the center, resulting in an unevenly deposited wide web. Even if this is done, a nonwoven fabric with a uniform basis weight over the entire width cannot be obtained. The inventors of the present invention focused on such problems and, as a result of intensive research, found that when a large number of ejectors are arranged in one or more rows in the width direction, the ejected airflow from adjacent ejectors is An effective means for selectively and uniformly dispersing the jet air flow from each ejector in the width direction sufficiently so as not to be affected by the air flow, and for expanding the boundary area of the free air jet itself in the width direction. As a result, they succeeded in producing a nonwoven fabric with an isotropic strength distribution in which the strength in the longitudinal direction of the nonwoven fabric is close to the strength in the lateral direction. That is, the present invention suction-draws a group of undrawn filaments from a spinneret using round ejectors arranged in one or more rows in the width direction of the nonwoven fabric over the entire width of the nonwoven fabric to be produced,
In an apparatus for producing long fiber nonwoven fabric that is laminated on a collection surface to form a web, a guide pipe is connected to the injection pipe of a round ejector, and the guide pipe is connected to the width of the web formed on the collection surface. A set of two of them are inserted into the diffuser so as to be parallel to each other in the direction, and the inner surface of the diffuser forms a diffuser opening with a rectangular cross-sectional shape, and also forms the short side of the rectangle. This is a long-fiber nonwoven fabric manufacturing device that has a pair of pressurized air jetting ports on two opposing sides that jet pressurized air alternately from each side. An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Reference numeral 1 denotes round ejectors arranged in the width direction of the web, and a guide pipe 3 is connected to an injection pipe 2 of the ejector 1. Note that d is the inner diameter of the guide tube 3. 4 is a supply pipe for pressurized air to be supplied to the ejector 1. The guide tubes 3 are made into a set of two, and a diffuser 5 is formed.
It is inserted into the opening. This guide tube 3 is 2 pieces 1
As shown in detail in FIG. 2, the two guide tubes 3 are inserted into the diffuser 5 as a set and opened in the width direction of the web to be formed on the lower collecting surface. They are lined up and inserted into the diffuser 5 and open. In addition to this, the second
To explain with the drawings, a in FIG. 2 is a front sectional view of the diffuser 5 viewed from the direction of travel of the web, b in FIG. 2 is a side sectional view of the diffuser 5, and c in FIG. is a plan cross-sectional view of the diffuser 5 cut along a plane passing through the pressurized air jet port at right angles to the air jet direction;
As can be clearly seen from this figure, the interior of the diffuser 5 forms a diffuser port 6 that widens toward the tip and has a rectangular cross-sectional shape. The direction of the long side of this rectangle, the left and right direction in the figure, is the width direction (horizontal direction) of the web to be formed, and the direction of the short side, the up and down direction in the figure, is the length of the web. This is the horizontal direction (vertical direction). In addition, in the diffusion port 6 of the diffuser 5, θ represents the opening angle, L represents the length, and W represents the inner width. Also, pressurized air outlets 7, 7' are provided near the lower end of the diffusion port 6. Reference numeral 8 denotes a pressurized air supply pipe, which is connected to a rotary switching valve 9. 10, 10' are pressurized air pipes from the rotary switching valve 9, and these pressurized air pipes 10, 1
From 0', a compressed air supply pipe 1 opens to the pressurized air outlets 7 and 7' in the diffusion port 6 of the diffuser 5.
1 and 11' are branched. Therefore, the pressurized air from the pressurized air supply pipe 8 is alternately switched and supplied to the pressurized air pipes 10 and 10' by the rotary switching valve 9, and the compressed air is sent from the pressurized air pipes 10 and 10'. Pressurized air is alternately injected into the diffusion port 6 from pressurized air jet ports 7, 7' which open into the diffusion port 6 of the diffuser 5 via supply pipes 11, 11'. On the other hand, pressurized air is supplied to the ejector 1 from a pressurized air supply pipe 4, whereby a group of filaments F from a spinneret (not shown) is sucked and pulled, and the ejected air from the ejector 1 is drawn. As described above, the filament groups from the two ejectors are delivered to one diffuser through the injection pipe 2 and guide pipe 3 along with the flow. The filaments fed through the diffusion port 6 of this diffuser are subjected to alternate jets of pressurized air from pressurized air outlets 7 and 7' located near the lower end of the diffusion port 6, and are directed to the collection surface 12 of the web. The alternating injection of pressurized air from the pressurized air outlets 7, 7' will be explained mainly with reference to Fig. 3. The pressurized air from the pressurized air supply pipe 8 is divided into two and alternately by the rotary directional control valve 9, and the air is sent to the pressurized air pipes 10 and 10', which are used as pressurized air jets. It has already been explained that the injection is carried out alternately from the outlets 7 and 7', but this pressurized air supply pipe 8
For example, a rotary directional valve 9 is used to divide the pressurized air into two streams and to cause these divided streams to flow alternately. The rotary directional control valve 9 is composed of an outer cylinder 13 and an inner cylinder 14. The center of this inner cylinder 14 is a hollow space, and the pressurized air from the pressurized air supply pipe 8 is directed to this central hollow space 15.
sent to The inner cylinder 14 has delivery holes 1 at equal intervals.
6 (nine in the figure) are provided. On the other hand, the outer cylinder 13 is provided with two through holes 17 and 17' at symmetrical positions with respect to the center of the outer cylinder 13,
The previously described pressurized air pipes 10, 10' are connected to the through holes 17, 17', respectively.
It is desirable that the outer peripheries of the through holes 17, 17' of the outer cylinder 13 and the delivery hole 16 of the inner cylinder 14 have the same shape and size. Furthermore, the inner cylinder 14 is rotatable. An odd number of delivery holes 16 are provided in the inner cylinder 14 at equal intervals, while two through holes 17 and 17' are provided in the outer cylinder 13 at symmetrical positions with respect to the center thereof. Through hole 17 and delivery hole 1
When the outer circumferences of the holes 6 and 6 coincide with each other, the through hole 17' located symmetrically with the through hole 17 is closed by the inner cylindrical wall 18 of the non-delivery hole portion located in the middle of the delivery hole 16. Become. Therefore, in the state shown in the figure, pressurized air flows from the central cavity 15 through the distribution hole 16 and from the through hole 17 to the pressurized air pipe 10, and this pressurized air passes through the compressed air supply pipe 11 and is then pressurized. The compressed air is ejected from the air ejection port 7 to the diffusion port 6 of the diffuser 5 . At this time, through hole 1
7' is closed by the inner cylinder wall 18, so that no pressurized air is supplied, and no pressurized air is ejected from the pressurized air outlet 7' of the diffusion port 6 of the diffuser 5.
When the inner cylinder 14 rotates in the direction of the arrow from this state,
The passage hole 17 is gradually closed, and on the contrary, the passage hole 17' begins to communicate with the delivery hole 16, and when it rotates further and the inner cylinder 14 rotates by 1/18 in the case of the figure, On the contrary, the through hole 17 is closed by the inner cylinder wall 18, and the through hole 17' coincides with the outer periphery of the delivery hole 16 and completely communicates with it, so that the pressurized air in the central cavity 15 is On the contrary, it flows into the pressurized air pipe 10' and is ejected from the jet port 7', and the pressurized air pipe 10
The flow of the pressurized air is stopped, and the jetting from the pressurized air jetting port 7 is stopped. Hereinafter, as the inner cylinder 14 rotates, the central cavity 15
The flow of pressurized air from the outlet 7 is switched to
The ejections from 7' will be alternated. At this time, the ejector 1 at the diffusion port 6 of the diffuser 5
Looking at the flow of air from the pressurized air outlet 7, when the pressurized air outlet 7 is completely blocked, and at the moment when the pressurized air outlet 7' is completely communicated with, the air is pushed toward the blocked pressurized air outlet 7. Although the two ejectors are approaching each other, the airflows ejected from the two ejectors become accompanying flows and pull toward each other, and try to be located in the center of the diffusion port 6, so the jets that adhere to the inner wall of the diffusion port are I'm not used to it. At the next moment, when the pressurized air outlet 7, which was completely blocked, becomes slightly open, and conversely, the pressurized air outlet 7', which was completely communicated, becomes slightly blocked, The airflow ejected from the ejector begins to move toward the center of the diffusion port 6. Furthermore, until the pressurized air jet port 7', which has been blocked for a while, becomes completely blocked, the air flow ejected from the ejector passes through the center of the diffusion port due to its inertial force. , then,
It continues to move toward the pressurized air outlet 7', which is about to be blocked, and eventually reaches it. By repeating similar movements at very short intervals, 2
The filaments from the two ejectors are oscillated, spread out and deposited on the collection surface 12 of the web. In addition, the basis weight of the web deposited by one diffuser is slightly smaller at the ends, but forms a substantially uniform distribution over the entire width. Figure 4 schematically represents the state of the basis weight distribution of a web deposited by one diffuser. Even if oscillating diffusion using pressurized air is used, adhesion jets tend to form on the inner wall surface of the diffuser, and many filaments gather at the end of the deposited web, as shown in Figure 4a. This results in an uneven distribution. In addition, the airflow from two ejectors (filament groups are fed simultaneously) is simply sent to one diffuser, and the swinging by alternate jetting of pressurized air as in the present invention is not combined. If so, the ejected flows from the two ejectors attract each other and accumulate a large amount of filaments only in the center due to the accompanying effect, resulting in an uneven distribution as shown in Fig. 4b. The distribution will not be as shown in c in Fig. 4, which is the basis weight distribution. If, as in the present invention, several diffusers capable of uniformly and widely depositing a web are arranged and deposited in the width direction of the web depending on the width of the nonwoven fabric, the difference in strength in the vertical direction and strength in the lateral direction is It is possible to obtain a uniform nonwoven fabric with a small amount of This is because the individual diffusers can be spaced apart from each other to such an extent that they are not affected by the air flow emitted from adjacent diffusers, and the oscillating effect of the diffusers also makes it possible to move the web. Since the constituent filaments are randomly oriented in both the vertical and horizontal directions of the web, a uniform nonwoven fabric with little difference in strength in the vertical and horizontal directions can be obtained. . In the present invention, locating the pressurized air outlet opening in the diffusion port above the diffusion port tends to cause jets to adhere to the inner wall of the diffusion port, as described above.
Since this impairs the uniformity of distribution and spreadability, it is desirable to position it as close to the bottom end of the diffuser as possible, and optimally within 20 mm from the bottom end of the diffuser. In addition, in the present invention, the time required to switch the direction of the pressurized air for swinging, that is, the swinging reciprocating speed and the pressure of the pressurized air, are important conditions for obtaining uniform distribution. However, if the swinging reciprocating speed is too high or the pressure of the pressurized air is too low, the swinging motion itself will not occur and the web diffusion effect will not be obtained, making it impossible to deposit a wide web. On the other hand, if the swinging reciprocating speed is too slow or the pressure of the pressurized air is too high, there will be a synergistic effect between the force trying to move to the center due to the accompanying effect of the jet flow from the ejector and the pushing force of the pressurized air. This makes the travel time of the jet from the ejector containing the filament oscillating in the diffuser very fast, and as a result the residence time of the jet from the ejector, which is pushed to one side by the pressurized air, is required to travel. If the length of time is longer than the time required, the web will have an uneven distribution with many filaments gathered at the ends, which is undesirable. Therefore, the time it takes for the pressurized air outlet to go from being completely communicated to being completely closed to being completely communicated again, that is, the swinging reciprocating speed per reciprocation is:
A very short time of 0.1 to 0.5 seconds is desirable, and the pressure of pressurized air for rocking is 0.5 seconds.
Kg/cm ² G to 2.0 Kg/cm ² G is desirable. Regarding the opening angle θ of the diffusion port in the present invention,
It is determined by the distance between the web collection surface and the diffuser, that is, the deposition distance, and the web deposition width required per one diffuser. The relationship between spinning capacity and production speed, the distance between the diffusers required to reduce the difference between the strength in the longitudinal direction and the strength in the lateral direction of the resulting web, and the opening of the filaments that make up the web. It is decided by taking all these conditions into account, spreading the ejected air flow uniformly in the width direction, depositing the web, and reducing the difference in strength in the longitudinal and lateral directions. The opening angle θ for obtaining a less isotropic nonwoven fabric is from 8 degrees to 24 degrees. Note that if the opening angle θ is small, a wide web cannot be obtained, and the distance between the individual diffusers arranged in the width direction of the web cannot be set very far apart, so as mentioned above, the strength in the vertical direction is If the opening angle is too large, the position of the pressurized air outlet will be too far from the center of the diffusion port, and the oscillating diffusion effect will not be achieved. Even if a diffusion effect can be obtained and a wide web can be deposited, the problem arises that productivity cannot be increased due to the limitations of the spinning capacity of one ejector and the spreadability of the filaments that make up the web. . Furthermore, the optimum condition for the length L of the diffusion port is determined by the amount and speed of air ejected from the ejector and introduced into the diffuser, and the inner diameter d of the guide pipe connected to the ejector's injection pipe. Under normal conditions, that is, when the pressure of the high-pressure air supplied to the ejector is within the range of 1 kg/cm ² G to 5 kg/cm ² G, the length L of the diffusion port is 3 to 7 times the inner diameter d of the guide tube. desirable. In the present invention, the ejected air flows and filament groups from two ejectors are sent to one diffuser, where they are collected and deposited at the same time, so the spinning capacity (processing capacity) per diffuser is 2. It also has the advantage of being doubled. Next, the present invention will be explained in more detail with reference to Examples. Example 1 A group of 48 undrawn polyester filaments spun from a spinneret were sucked into each 24 filaments by an ejector supplied with high-pressure air of 3 kg/cm ² G, and pulled into a guide connected to the ejector. It was delivered to one diffuser by a tube. The opening angle θ of the diffusion port is 16 degrees, its length L is 50 mm, and a pressurized air outlet for swinging is provided at a position 10 mm above the bottom end of the diffusion port. The filament group was drawn by the two ejectors described above onto a collecting surface that was set 70 cm below the bottom end of the diffuser and moved at a speed of 5 m/min, so that the single filament denier was 3 d.
48 drawn filaments were deposited to form a web. Based on these basic conditions, the time it takes for the pressurized air outlet to go from being fully connected to being fully connected again, that is, the swinging reciprocating speed, is 0.05 seconds, 0.10 seconds, 0.20 seconds per reciprocation, 0.30 seconds, 0.50
seconds, 0.70 seconds, and at these swinging reciprocating speeds, the pressure of the pressurized air jetted from the pressurized air jet port is 0Kg/cm ² G, 0.25Kg/cm ² G, 0.50Kg/cm ²
G, 1.00Kg/cm ² G, 1.5Kg/cm ² G, 2.00Kg/cm ² G,
The conditions were 2.50 Kg/cm ² G and 3.00 Kg/cm ² G, and the width direction basis weight distribution of the web deposited on the collection surface of the web was observed under these conditions, and the deposition width was measured. At the same time, the only difference from the above conditions is that 48 undrawn filaments are suctioned and pulled by one ejector, fed to one diffuser, and deposited on the collection surface.Other conditions are the same as above. A similar web was deposited. The results are shown in Table 1 below.

【table】

[Table] As can be seen from this table, when the filaments from two ejectors were fed to one diffuser, a web with a nearly uniform distribution of area weight was obtained up to a deposition width of about 60 cm. When the filament from the ejector was fed to one diffuser, even if a wide deposition width could be obtained, only a non-uniform web with a small basis weight in the center of the web could be obtained.
From this, when a group of filaments from two ejectors are fed to one diffuser, the oscillation caused by the pressurized jet air and the accompanying effect of the jets from the two ejectors combine well to form a uniform web. I understand that. To obtain a wider web, the pressure of pressurized air for rocking should be at least 0.5
Kg/cm ² G is required, and if a pressure higher than 2 Kg/cm ² G is applied, the web will have a non-uniform basis weight distribution with many filaments gathered at the ends.
It has also been found that the appropriate speed for alternating the direction of the pressurized air is within the range of 0.1 to 0.5 seconds per reciprocation. Comparative example with Example 1 A pressurized air jet for swinging that opens at the diffusion port of the diffuser is located above the diffusion port, that is, near the end of the guide tube inserted into the diffusion port. In the same manner as in Example 1, 48 undrawn polyester filaments from the spinneret were suctioned and pulled by two ejectors to 24, and then fed to one diffuser to collect and deposit the web on the collection surface. did. According to this study, even if the pressure of the pressurized air from the pressurized air outlet in the diffusion port is increased to 3 kg/cm ² G, the width of the web piled up is only about 45 cm, and moreover, many filaments are concentrated at the ends of the web. However, only a web with uneven basis weight distribution could be obtained. Example 2 When obtaining a long-fiber nonwoven fabric with a width of 180 cm and a basis weight of 70 g/m ² made of polyester filaments with a single yarn denier of 3d by a spunbond method, a group of filaments from a spinneret were arranged in a line in the width direction of the web. It was delivered to the diffuser by an ejector. At this time, 60 filaments were inserted into one ejector, and air at a pressure of 3.0 Kg/cm ² G was supplied. A guide tube is connected to each ejector, and two of the guide tubes are inserted into one diffuser. Therefore, the filaments of two ejectors will be fed to one diffuser. The diffusion port of the diffuser has an inner width W of 2 mm and an opening angle θ.
is 10 degrees and the length L is 60 mm. Further, a pressurized air outlet is opened at a position 10 mm above the lower end of the diffuser. The pressure of the pressurized air from this pressurized air outlet was 1.5 Kg/cm ² G, and it was ejected for 0.2 seconds per reciprocation. Five diffusers were arranged in a row at 360 mm intervals, and filaments from 10 ejectors were fed to one diffuser using two ejectors as a set. The web is collected and deposited on a collecting surface that moves at a rate of 10.1 m/min, and the web is collected and deposited on a collecting surface that has a basis weight of approximately 56 g/min.
I created a web of ^m2 . On the other hand, without using any diffuser, 40 ejectors were arranged in a row at 45 mm intervals and 15 filaments were drawn by suction to one ejector.
A web having a basis weight of 56 g/m ² was prepared by depositing it on a web collecting surface that was traveling at a rate of 10.1 m/min. Each of the webs thus obtained was impregnated with an emulsion type adhesive and dried to produce a nonwoven fabric with a finished area weight of about 70 g/m ² . Table 2 shows these manufacturing conditions and the physical properties of the obtained nonwoven fabric. As can be seen from Table 2, the ratio of the vertical strength to the horizontal strength of the nonwoven fabric manufactured using the diffuser is
1.13, indicating that a far more isotropic nonwoven fabric was obtained compared to the ratio of vertical strength to horizontal strength of 2.89 for a nonwoven fabric manufactured without using a diffuser.
In addition, when manufacturing without using a diffuser, if the distance between the ejectors was made larger than 45 mm, vertical streaks corresponding to the distance between the ejectors occurred, and a nonwoven fabric with a uniform basis weight across the entire width could not be obtained.

【table】 [Brief explanation of the drawing]

The accompanying drawings are for explaining the present invention, and FIG. 1 is a schematic diagram showing an example of the implementation of the present invention, and FIG. 2 is a schematic diagram showing an example of the diffuser in the present invention.
3 is a front cross-sectional view as seen from the traveling direction of the web, b is a side cross-sectional view, c is a plane cross-sectional view on a plane passing through the pressurized air jet nozzle, and FIG. 3 is a cross-section showing an example of the rotary directional control valve of the present invention. Figures 4 and 4 are diagrams schematically representing the state of the basis weight distribution of a web deposited by one diffuser, where a shows a state where the distribution is thick on both sides, and b shows a state where the distribution is thick in the center. thickened state,
c represents a substantially uniformly distributed state. 1: Ejector, 2: Injection pipe, 3: Guide pipe,
5: Diffuser, 6: Diffusion port, 7, 7': Pressurized air outlet.

Claims (1)

[Scope of Claims] 1. A group of undrawn filaments from a spinneret is drawn and captured by suction over the entire width of the nonwoven fabric to be produced by a round ejector arranged in one or more rows in the width direction of the nonwoven fabric. In an apparatus for producing a long fiber nonwoven fabric that is laminated on a collection surface to form a web, a guide pipe is connected to the injection pipe of a round ejector. A set of two of them are inserted into the diffuser so as to be parallel to each other in the direction, and the inner surface of the diffuser forms a diffuser opening with a rectangular cross-sectional shape, and also forms the short side of the rectangle. 1. An apparatus for producing a long fiber nonwoven fabric, comprising a pair of pressurized air jetting ports on two opposing surfaces for jetting pressurized air alternately from each surface. 2. The apparatus for producing a long fiber nonwoven fabric according to claim 1, wherein the pressurized air outlet in the diffusion port is provided within 20 mm from the lower end of the diffusion port. 3. The apparatus for manufacturing a long fiber nonwoven fabric according to claim 1 or 2, wherein the opening angle θ of the diffusion port is 8 degrees to 24 degrees. 4. The long fiber nonwoven fabric manufacturing apparatus according to claim 1, 2, or 3, wherein the length L of the diffuser is 3 to 7 times the inner diameter d of the guide tube attached to the ejector.