JPH08226062A - Production of filament web - Google Patents

Abstract

PURPOSE: To stably produce a filament web having improved uniformity of the web and directional uniformity of the web properties. CONSTITUTION: A filament group taken up by a number of ejectors 1 arranged in the lateral direction of a net is collected in the form of a web by colliding the filament group with collision plates 2-4 each composed of plural plates. The final collision plates 4 are arranged in a row and the directions of fibers entering into the final collision plates 4 are alternately reversed. The interference between the fibers of the adjacent spindles is eliminated and each filament group is independently opened and dropped to collect a web in high uniformity.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a long fiber web.

[0002]

2. Description of the Related Art Conventionally, an air stream such as an ejector is used to suck a filament group obtained from a spinneret,
A method has been reported in which, after the fibers are opened, they are collected on a net (net conveyor) to form a long fiber web. As a method of forming a long fiber web, a method of collecting in a comb shape using a rectangular ejector, a method of arranging a number of round ejectors in a line in the net direction, and collecting a long fiber web have been reported. ing.

In the former case, since the filament group is collected in a comb shape, it is possible to collect the web without the fibers interfering with each other, but the air flow is jetted from the entire surface in the width direction of the web. Therefore, there is no room for diffusion in the width direction of the web, so there is no choice but to diffuse in the traveling direction of the web.
Therefore, the filament group conveyed in the air flow has a high probability of being arranged in the traveling direction of the web, and thus the tensile strength in the traveling direction of the web is high, but the strength in the transverse direction is low, and the longitudinal direction of the obtained sheet is reduced. / There is a drawback that only a large aspect ratio can be obtained.

Further, the rectangular ejector has a problem that the amount of compressed air used is larger than that of the round ejector, which is disadvantageous in terms of cost.

In the latter case, since a large number of ejectors are arranged side by side, the filament groups ejected from the adjacent ejectors interfere with each other, which deteriorates the uniformity of the web, and the ejection flow from the adjacent ejectors. This suppresses the lateral diffusion of the web, which facilitates vertical orientation and increases the aspect ratio.

In order to solve these problems, a method of increasing the distance between adjacent ejectors and a method of providing a partition plate between adjacent weights have been reported. However, if the method of increasing the distance between the ejectors is used, the number of ejectors per width is reduced, resulting in poor productivity. If it is attempted to increase the number of filaments per ejector in order to increase the productivity, the spreadability will be deteriorated and the uniformity of the web will be deteriorated, which is not preferable.

Further, in the method of providing the partition plate between the adjacent weights, the spread of the web in the width direction is regulated, so that the uniformity of the web is deteriorated and the jet air flow is also reduced. Is also regulated, and the web tends to be oriented vertically, and the aspect ratio becomes large.

As a method for solving these problems, JP-A-62 / 62
In Japanese Patent Laid-Open No. 170570, in a method in which fibers ejected by a row of ejectors collide with a first collision plate and then collide with a second collision plate to open the fibers, the first collision plate is swung. Further, a method is disclosed in which, for each adjacent ejector, the ejection angles of the fiber bundles from the second collision plate are staggered, and the adjacent ejection fibers overlap each other in the web width direction and are collected on the net. ing.

Further, Japanese Patent Laid-Open No. 62-177721 discloses a method of collecting the web by changing the height of the ejection port of the adjacent ejector and attaching a separating wall for each height. There is.

However, in either case, the webs can be accumulated without the fibers ejected from the adjacent ejectors interfering with each other. However, the widths of the webs differ depending on the ejectors, and the basis weight of the webs in the width direction is determined. The uniformity is reduced.

In order to compensate for this, the collision plate is swung, but since the widths of adjacent webs are different, it is not preferable because the swirling may cause unevenness of the web. Further, according to the study by the present inventors,
When the webs are collected in multiple stages, there are drawbacks that the webs are easily separated when the webs are separated from the net, and the effect of static elimination performed to prevent these is reduced.

[0012]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, improves the uniformity of the web, and produces a long fiber web having an improved web aspect ratio. To provide a method.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a filament group obtained from a spinneret is taken by a large number of ejectors arranged in a lateral direction, and the taken filament group is applied to a plurality of collision plates and then dropped. When collecting the web to be used on the net, arrange the final collision plates in a line,
In the method for producing a long fiber web, the filament groups are alternately incident on the final collision plate in opposite directions.

In the present invention, the spinnerets for spinning the long fiber web may be arranged in a line in the width direction of the net conveyor for collecting the long fiber web, or may be arranged in a staggered arrangement. . However, in any case, it is preferable that the distances between adjacent spinnerets are equal. The filament group spun from the spinneret may be directly supplied to the ejector and sucked to be ejected, or may be supplied to the ejector after being taken by a high-speed take-off roller or the like.

In any case, the filament group supplied to the ejector is preferably supplied straight to the ejector. When the filament group is supplied at an angle, rubbing of threads occurs at the ejector suction port,
This is not preferable because it lowers the spinning speed and changes the yarn quality.

The material for forming the filament group is not particularly limited as long as it is a fiber-forming material, and polyester, polyamide, polypropylene, polyethylene, etc., synthetic fiber made of a copolymer thereof, or a composite containing these. It may be fiber. Further, usual additives such as matting agents, heat stabilizers and pigments may be added.

[0017]

According to the present invention, when the filament group is taken up by a large number of ejectors arranged in the lateral direction of the net as described above and the taken filament group is collided with a plurality of collision plates and taken out on the net, the filament group is arranged in a line. The filament groups are alternately incident on the final collision plate arranged in the opposite direction to collide with each other. For this reason, the fibers of adjacent weights do not interfere with each other, and each filament group is independently opened and dropped, so that the webs are collected in a uniform manner, and the long fibers with excellent uniformity and longitudinal / horizontal characteristic ratio are also obtained. The web can be manufactured stably and easily.

The operation and effect of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a plan view (top view) of an embodiment for explaining a method for producing a long fiber web according to the present invention.
2 (a) and 2 (b) are respectively A- of FIG.
FIG. 9 is a view taken in the direction of arrows A ′ and BB ′, showing an example in which ejectors for sucking and ejecting filament groups spun from the spinneret are arranged in a line at right angles to the web width direction. Further, FIG. 3 is a plan view showing another embodiment, which is an example of staggered arrangement, and FIGS. 4 (a) and 4 (b).
3A and 3B are a view taken along the arrows CC 'and DD' of FIG. 3, respectively. 1 to 4, MD means the machine flow direction, and the arrow direction indicates the machine flow direction.

In FIGS. 1 and 2, a filament group spun from a spinneret (not shown) is supplied to and sucked by the ejector 1. Below the ejector 1, there is a first collision plate 2
Is installed, the filament group ejected by the ejector 1 collides with the first collision plate 2, and the filament group is opened by this collision force and frictional charging. The position and material of the first collision plate 2 may be appropriately set depending on the type of polymer. Further, in the case of a polymer that is difficult to be triboelectrically charged, a fiber opening technique such as corona discharge may be used together.

The filament group ejected from the first collision plate 2 collides with the second collision plate 3 and the third collision plate 4 arranged on the side of or below the collision plate 2 and then on the net (net conveyor). To collect. As shown in FIG. 1, when the ejectors 1 are arranged in a line in the width direction of the net (right angle to the traveling direction), the second collision plate 3 has a surface perpendicular to the net and a constant surface with this surface. It is composed of the surfaces that make an angle of
Web (filament group) for each weight (each ejector 1)
The positions are arranged in opposite directions so that the traveling directions of are opposite. Similarly, the first collision plates 2 are also arranged in opposite directions.

In this case, if the second collision plate 3 is arranged in the same direction for each weight, the distance between the weights becomes close and adjacent fibers interfere with each other, which is not preferable. By arranging these in reverse, it becomes possible to eliminate the interference between the fibers as described above without increasing the distance between the adjacent ejectors 1. The filament group that has left the second collision plate 3 has a third collision plate 4 arranged perpendicular to the net direction.
After being collided with, is captured on the net.

As shown in FIGS. 3 and 4, when the ejectors 1 are arranged in a zigzag manner, the second collision plates 6 are arranged vertically in the net direction like the third collision plates 4 described above. Here, it is preferable that the directions of incidence of the fibers from the first collision plate 5 to the second collision plate 6 are opposite, and the distance between the second collision plates 6 between the rows is as short as possible. The fibers may be made to collide in opposite directions by using one collision plate in one horizontal row.

When the webs are collected in rows in a zigzag arrangement, each layer is easily peeled off when the conveyed web is separated from the net, which is not preferable. This is because it is difficult to remove static electricity from the web that was collected first when the web is removed in order to move it from the net to the next process, when collecting it in rows. It is difficult to happen. When the webs are collected in almost one line without being separated, the above phenomenon is eliminated, and the web can be quickly conveyed to the next step.

The final collision plate according to the present invention is arranged in a line with respect to the net regardless of the arrangement of the spinneret or the ejector, and the fibers entering the final collision plate are arranged so that the incident directions are opposite to each other. . At this time, the incident angle of the fibers is preferably 45 to 75 ° with respect to the final collision plate. If this angle is smaller than 45 °, the impact force of the filament group tends to decrease, while if it is greater than 75 °, the impact force increases, so that the openability is improved, but the uniformity of the web is rather deteriorated. May come. Here, the incident angle of the fiber means, as shown in FIG.
The angle θ between the fiber incident direction and the collision plate is meant.

The fiber contact length in the final collision plate is
It is preferably 50 mm or less. If this distance becomes long, the fibers are likely to adhere to the collision plate, and the uniformity of the web to be collected may be deteriorated and become unstable.

[0026]

EXAMPLES The present invention will be described in more detail below based on examples.

Example 1 Twelve caps each having a cap diameter of 60 mm, a cap interval of 80 mm, and a cap hole number of 72 were arranged in a horizontal row, and polyethylene terephthalate was spun at a discharge rate of 1.2 g / min per cap. The spun filament group is sucked by an ejector placed 900 mm directly below the spinneret and pulled at a speed of 4,500 m / min, and then collides with the first to third collision plates as shown in FIG. Then, the long fiber web was collected on a net.

The first collision plate was set at a position 20 mm below the ejector, and the fiber incident angle to the first collision plate was 60 ° and the fiber contact length was 20 mm. The fiber contact length on the second collision plate was 20 mm, and the fiber incident angle on the third collision plate was 6 mm.
The fiber contact length at the third collision plate arranged perpendicularly to the net was 30 mm. The directions of the first collision plate and the second collision plate were reversed for each weight.

The long fiber web thus obtained is conveyed and treated with an embossing calendar to give a basis weight of 30 g.
A sheet of / m ² was obtained. When the uniformity and strength / width strength characteristic ratio of the obtained sheet were evaluated, the results shown in Table 1 were obtained.

Comparative Example 1 Under the same conditions as in Example 1 up to the ejector, after being sucked by the ejector, they were collided with the first collision plate and the second collision plate, and the long fiber web was collected on the net. The first collision plate was installed 20 mm below the ejector, and the fiber incident angle to the first collision plate was 60 ° and the fiber contact length was 20 mm.
The angle of fiber incidence on the second collision plate arranged perpendicular to the net was 60 °, and the fiber contact length there was 20 mm. All the first collision plates had the same orientation.

The long-fiber web thus obtained is conveyed and treated with an embossing calendar to give a basis weight of 30 g.
A sheet of / m ² was obtained. When the uniformity and strength / width strength characteristic ratio of the obtained sheet were evaluated, the results shown in Table 1 were obtained.

Example 2 Twelve ferrules having a ferrule diameter of 60 mm, a ferrule spacing of 120 mm and a ferrule number of 72 holes were arranged in a zigzag in two rows, and polyethylene terephthalate was spun at a discharge rate of 1.2 g / min per ferrule. This spun filament group is 900 directly under the spinneret.
4,500m by suction with an ejector placed in mm
After being pulled at a speed of / min, the long fiber web was collected on a net by colliding with a first collision plate and a second collision plate as shown in FIG.

The first impingement plate was installed 20 mm below the ejector, and the fiber incident angle to the first impingement plate was 60 ° and the fiber contact length was 20 mm. The angle of fiber incidence on the second collision plate arranged perpendicular to the net was 60 °, and the fiber contact length there was 20 mm. The direction of the first collision plate was reversed for each weight.

The long fiber web thus obtained is conveyed and treated with an embossing calendar to give a basis weight of 30 g.
A sheet of / m ² was obtained. When the uniformity and strength / width strength characteristic ratio of the obtained sheet were evaluated, the results shown in Table 1 were obtained.

Comparative Example 2 Under the same conditions as in Example 2 up to the ejector, suction was performed by the ejector, and then colliding with the first collision plate and the second collision plate, the long fiber web was collected on the net. The first collision plate was installed 20 mm below the ejector, and the fiber incident angle to the first collision plate was 60 ° and the fiber contact length was 20 mm.
The angle of fiber incidence on the second collision plate arranged perpendicular to the net was 60 °, and the fiber contact length there was 20 mm. All the first collision plates had the same orientation.

The long fiber web thus obtained is conveyed and treated with an embossing calendar to give a basis weight of 30 g.
A sheet of / m ² was obtained. When the uniformity and strength / width strength characteristic ratio of the obtained sheet were evaluated, the results shown in Table 1 were obtained.

[0037]

[Table 1]

The sheet unevenness was determined by the following method. The cv% in the vertical direction of the web is the variation rate (cv) = {σ by statistical calculation of n = 120 in the weight method of length 25 mm × width 25 mm.
(Standard deviation) / x (average value)} × 100. The cv% in the horizontal direction of the web was determined by the statistical method of n = 120 by the weight method of length 250 mm × width 25 mm, and the variation rate (cv) = {σ (standard deviation) / x (average value)} × 100. The vertical / horizontal strength ratio was obtained by sampling a test piece of 200 mm long × 50 mm wide from the sheet, measuring the strength (kg / 50 mm) in the vertical and horizontal directions by a tensile tester, and determining the vertical / horizontal ratio.

[0039]

As described above, according to the present invention, when a plurality of ejectors arranged in the width direction of the net are applied to a plurality of colliding plates to collect the web, , The final collision plates are arranged in a line, and the incident directions of the fibers entering the final collision plates are alternately reversed. For this reason, the fibers of adjacent weights do not interfere with each other, and each filament group is independently opened and dropped, so that the webs are uniformly accumulated, and the uniformity and the longitudinal / lateral characteristic ratio are excellent. The remarkable effect that a fiber web can be manufactured stably and easily is produced.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a manufacturing method of the present invention.

FIG. 2A is a view taken along the line AA ′ of FIG. (B)
FIG. 2 is a view taken along the line BB ′ of FIG.

FIG. 3 is a plan view showing another embodiment of the manufacturing method of the present invention.

FIG. 4A is a view taken along the line CC ′ of FIG. (B)
FIG. 4 is a view on arrow DD ′ of FIG. 3.

FIG. 5 is an explanatory diagram of a fiber incident angle θ.

[Explanation of symbols]

 1 Ejector 2 1st collision plate 3 2nd collision plate 4 3rd collision plate 5 1st collision plate 6 2nd collision plate

Claims (6)

[Claims] 1. A filament group obtained from a spinneret is taken up by a large number of ejectors arranged in a lateral direction,
The collected filaments are applied to a plurality of collision plates, and then the falling web is collected on the net.
A method for producing a long fiber web, wherein the final collision plates are arranged in a line, and the respective filament groups are alternately incident on the final collision plates in opposite directions. 2. The method for producing a long fiber web according to claim 1, wherein the final collision plate is arranged perpendicular to the net. 3. The angle of incidence of the fibers on the final collision plate is 45-.
The method for producing a long fiber web according to claim 1 or 2, wherein the angle is 75 °. 4. The method for producing a long fiber web according to claim 1, 2 or 3, wherein the fiber contact length at the final collision plate is 50 mm or less. 5. The method for producing a long fiber web according to claim 4, wherein the distances between adjacent spinnerets are equal. 6. The method for producing a long fiber web according to claim 4, wherein the filament group is linearly fed to the ejector.