JPH09324356A - Production of filament web - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a filament web, enabling to produce the filament web uniform in METSUKE and excellent in a longitudinal strength/latitudinal strength ratio in the span bond method. SOLUTION: This method for producing a filament web comprises spinning out multifilament groups from the group of approximately aligned parallel spinnerets, downwardly taking off the multifilament groups with ejectors 1, respectively, allowing the multifilament groups F to collide with collision plates 2 disposed below the spinnerets, respectively, spreading and loading the opened multifilament groups F on a moving conveyer net. Therein, the collision plates 2 are mutually synchronously, periodically and laterally swung so that the loaded truck of each multifilament group collided with each collision plate 2 and subsequently spread and loaded on the conveyer net N becomes an approximately zigzag line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinning device, in which a group of multifilament yarns spun from each of a group of spinnerets is taken up by an ejector group, and then the group of multifilaments taken out is collided with a group of colliding plates to be opened. And a method of manufacturing a long fiber web by spreading and placing the multifilament yarn group on a moving net.

[0002]

2. Description of the Related Art Conventionally, a group of filaments obtained from a spinneret is suctioned by using an air flow of an ejector or the like,
Many methods have been reported for forming a long fiber web by collecting on a running net conveyor after opening. As one of the methods, a large number of ejectors are arranged in a line in the net direction, the multifilament yarn group is sucked for each weight to open the fiber, and then the web is spread and placed on the moving net. There is a method to collect the web.

In such a method of arranging a large number of ejectors in the lateral direction, the uniformity of the web is deteriorated due to the interference of the filament groups ejected from the adjacent ejectors and the accompanying flow, and uneven web spots are generated in the web width direction. And the lateral diffusion of the web is suppressed, which facilitates orientation of the filaments in the longitudinal direction, resulting in an increase in the aspect ratio of the resulting web. Further, as the production speed increases due to the progress of the production apparatus, it is difficult to widen the web in the horizontal direction, and the web is more likely to be vertically oriented.

As a method for solving these problems, Japanese Unexamined Patent Publication No. 62-170570 discloses a method in which fiber bundles ejected by ejectors arranged in a line are collided with a first colliding member, and then, further. , A method of opening the fibers by colliding with the second collision member has been proposed. Here, the purpose of the method will be briefly described. In the method, the first collision members are swung, and a fiber bundle is ejected from each second collision member for each adjacent ejector. By making the angles alternate, the webs are piled up in a direction perpendicular to the traveling direction of the nets that move the fiber bundle groups ejected from the adjacent ejectors, and the fibers are spread and placed on the nets. To obtain a uniform long fiber web.

However, although it is possible to spread and place the web on the net without the fiber bundles ejected from the adjacent ejectors interfering with each other by the method, the final collision plate group is certainly possible. Since the (second collision plate group) is fixedly installed by changing the direction alternately, the fiber bundle ejection angle of the final collision plate also differs alternately.
For this reason, the width of the web to be obtained differs for each weight, and the uniformity in the width direction of the web deteriorates, which is a very serious problem.

Further, although this method temporarily swings the first collision member group, the swinging method is not specifically described except swinging in the width direction of the web. Means not shown. In addition to this, even more importantly, even if the first collision plate is rocked, the fiber bundle group collided with the collision plate is fixedly installed without any movement. (2) By colliding with the collision plate again, the spreading / placement position of the fiber bundle group is controlled.

In such a method, the fiber bundle group is certainly collided with the swinging first collision plate to open the fiber bundle group, thereby randomizing the array of the fiber bundle group on the moving net conveyor and spreading the fiber bundle group. -It is possible to obtain the effect of placing. However, the final collision plate for finally colliding and opening the fiber bundle group and spreading and placing it on the moving net is still fixed and placed at the position on the moving net. Spread the fiber at the intended position while controlling the fiber bundle group.
It has a problem that it cannot be placed at all.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the above-mentioned prior art, improves the uniformity of the basis weight of the web, and increases the vertical / horizontal direction of the obtained web even under the condition that the line speed is fast. It is an object of the present invention to provide a method for producing a long fiber web having an excellent aspect ratio and an excellent quality.

[0009]

According to the present invention according to claim 1, a multifilament yarn group is spun out from each of the spinneret groups arranged side by side in substantially one row, and each of the spinnerets is handled. The multi-filament yarn group spun by each ejector arranged underneath is pulled downward, and each multi-filament yarn is collided with each collision plate arranged in the yarn ejection direction of each ejector to open. In the method of producing a long fiber web by spreading and then placing the opened multifilament yarn group on a moving conveyor net, until ejected from each ejector and colliding with each collision plate. Assuming each virtual plane formed by moving the respective centerlines of the multifilament yarns in parallel with the moving direction of the net, the virtual planes intersect with the collision plates. The center line of the swing is used as a swing axis, and the collision plates are periodically swung to the left and right while being synchronized with each other. At that time, the collision plates collide with the collision plates and spread on the conveyor net. A method for producing a long fiber web, characterized in that each collision plate is subjected to a swinging motion such that the placed locus of each of the extended and placed multifilament yarns on the conveyor net becomes a substantially straight line in a zigzag shape. Will be provided.

According to a second aspect of the present invention, there is provided the method for producing a long fiber web according to the first aspect, wherein the rocking cycle of the collision plate group is 200 to 1000 times / minute.

According to the present invention of claim 3,
The method for producing a long fiber web according to claim 1 or 2, wherein when the collision plates perform the oscillating motion, switching of the oscillating plates in the oscillating direction is performed in a short time. .

Further, according to the present invention of claim 4, when swinging the collision plates, the deflection angle of the collision plates in the upward or downward direction with respect to the plane orthogonal to the virtual planes. Where ψ is −45 ° ≦ ψ ≦ 45 °
A method for producing a continuous fiber web according to any one of claims 1 to 3 is provided.

Finally, according to the present invention of claim 5,
Other collision plates were fixedly installed between the ejectors corresponding to the swinging collision plates and the collision plates, and ejected from the ejectors to the fixed collision plates. After each multifilament yarn is collided and opened, further, with respect to each of the swinging collision plates,
A method for producing a long fiber web according to any one of claims 1 to 4, wherein the opened multifilament yarns are collided with each other, and then spread and placed on a moving net.

Before describing the method for producing the continuous fiber web of the present invention, the filament group constituting the constituent material of the continuous fiber web of the present invention will be described in detail below.

In order to produce the above filament group, a known melt-spinning apparatus that is commonly used in producing thermoplastic synthetic fibers can be preferably used.

However, in the present invention, the spinneret group for spinning the filament yarn group in such a known melt-spinning apparatus is arranged substantially in a line in the width direction of the net for collecting the long fiber web. It is essential that they are installed. However, the spinneret groups need not necessarily be arranged in a regular and linear manner. For example, the spinneret groups may be arranged in a zigzag line in a zigzag pattern. That is,
What is necessary is that they are substantially arranged in a line. Here, the distance between adjacent spinneret groups is preferably equal to each other.

The filament yarn group spun from the spinneret group is directly supplied to each ejector.
It may be sucked and ejected from each of the ejectors,
The spun yarn may be supplied to each ejector after the spun yarn is once taken out by a high-speed take-up roller or the like. However, it is preferable that each filament yarn supplied to each ejector be supplied straight to each ejector.
If each filament yarn is supplied obliquely to each ejector, friction occurs due to the bending of the yarn at the suction port of each ejector, which increases the yarn take-up resistance and decreases the spinning speed. It is not preferable because it causes a change in yarn quality.

Next, the polymer for forming the filament is not particularly limited as long as it can be formed into a fibrous shape, and examples thereof include polyester, polyamide, polypropylene, polyethylene and the like, and copolymers thereof. Can be used. Further, ordinary additives such as a matting agent, a heat stabilizer and a pigment may be added to these.

Further, the fiber form of the filament itself does not necessarily have to be a homogeneous fiber composed of a single type of polymer, and a side-by-side type or a sheath type containing two or more types of polymers in one filament. It may be a core type conjugate fiber or a blend fiber in which two or more kinds of polymers are mixed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for obtaining a long-fiber web of the present invention using the above-described filament group will be described below in detail with reference to the drawings.

FIG. 1 is a schematic front view for explaining an apparatus for obtaining a long fiber web by the method of the present invention, and FIG. 2 is a schematic side view.

In the figure, reference numeral 1 is an ejector, 2
Represents a collision plate, and 3 represents a rocking device for rocking the collision plate. Reference symbol F represents a filament yarn group spun from a spinneret (not shown) (not shown). Further, a symbol N represents a net for spreading and placing the filament yarn group.

In the apparatus for carrying out the present invention configured as described above, the yarn (F) made of multifilament is spun out from each of the spinneret groups (not shown) juxtaposed in a line. The multi-filament yarn group (F) is drawn downward by the ejectors (1) arranged in parallel below the spinnerets. In addition, it is preferable that the multifilament yarn group (F) drawn downward is subjected to electric spreading (spreading by corona discharge).

The multifilament yarn groups (F) thus taken up are collided with the collision plate (2) and the fibers are opened by the impact force of the collision. Then, the opened multifilament yarn group (F) is spread and placed on the moving conveyor net.

Here, in the method of the present invention, the collision plate (2) is oscillated to the left and right, and the width direction of the web (the direction perpendicular to the moving direction of the conveyor net, hereinafter, unless otherwise specified). , Simply referred to as "width direction".) It is essential to spread and place the multifilament yarn group (F) opened into a long fiber web. The swinging motion of the group of collision plates (2) will be described in more detail.
When the collision plate group (2) is viewed from the side as shown in FIG. 2, the collision plate group (2) is provided to be inclined downward while forming an angle θ with respect to the vertical direction. It swings right and left around each swing center axis as a fulcrum.

That is, considering the loci of the center lines (C) of the multifilament yarns (F) from the ejectors (1) to the collision plates (3), the center lines ( First, consider each virtual plane (P) formed by translating C) in the moving direction of the conveyor net (N) (hereinafter, simply referred to as “MD direction” unless otherwise specified). Then, the virtual center line at which each of the virtual planes (P) intersects with each of the collision plates (2) is used as the pivot for swinging.

However, if the impact plate (2) is simply swung to the left and right with the virtual center line as a swing axis, the resulting web is less uniform in terms of basis weight. It is necessary to devise the method.

The method of the present invention is characterized in that the basis weight distribution of the obtained web can be made uniform, and this point will be described in detail below with reference to FIG.

In the conventional technology, generally, a crank mechanism or the like is used to convert a circular motion into a single horizontal motion in the left-right direction, and the single vibration oscillates each collision plate left and right. ing. According to such a method, as shown by the broken line in FIG. 3, the multifilament yarns spread and placed on the moving conveyor net are sequentially placed in a sine-shaped curve. go.

However, when each multifilament yarn is placed on the conveyor net in such a sine-shaped curve, the basis weight of the web becomes large near the peaks and valleys of the sine-shaped curve, The present inventors have discovered that a phenomenon occurs in which the weight of the web is reduced during the transition from the peaks to the valleys, or during the transition from the valleys to the peaks.

In order to eliminate such a phenomenon, as a result of intensive studies by the present inventors, the multi-filament yarns of the multifilament yarns collided with the collision plates and spread and placed on the conveyor net are conveyed on the conveyor net. It has been clarified that it is essential to swing each collision plate so that the mounting locus in (3) becomes substantially a zigzag straight line as shown by the solid line in FIG.

Here, in the present invention, the swing cycle of the collision plate group (2) may be appropriately selected depending on the speed at which the web of the conveyor net (N) is conveyed (speed in the MD direction). To increase the speed of the conveyor net (N) in order to improve the
About 000 times / minute is preferable. However, if the swing cycle of the collision plate (2) is shortened, the placing motion of the multifilament yarn group (F) on the conveyor net (N), which is swung in the left-right direction (width direction), causes the swing plate to swing. It is not preferable because it becomes impossible to follow the moving speed.

By the way, if the locus of accumulation of each multifilament yarn on the conveyor net has a gentle sine curve at the tip of the peak (valley) shown by the broken line in FIG. It is as described above that I have found that the number is larger than other parts. Therefore,
Close observation of this phenomenon has revealed that the speed at which the swinging direction of the collision plate (2) is switched becomes a problem.

In other words, when the collision plate (2) swings, if the swinging direction is gently switched, as described above, the peaks (valleys) form a gentle sine curve. I understood. For this reason, when each impact plate (2) swings, if the switching direction of each swing plate (2) is changed in a short time, the peak (valley) becomes an acute angle. It is possible to take such a trajectory.

However, it is extremely difficult to place each multifilament yarn (F) on the conveyor net (N) so as to form a zigzag accurate straight line as shown by the solid line in FIG. . This includes the distance between the impact plate (2) and the conveyor net, the swing angle (ψ) of the swing plate (2), the swing cycle of the swing plate (2), the take-up speed of each multifilament yarn, etc. Because it depends on the manufacturing conditions. Therefore, the placement locus of each multifilament yarn (F) on the conveyor net may be "a placement locus approximated to a substantially zigzag straight line" even if it is not a zigzag accurate straight line. Practically preferable.

In order to obtain such a "locating locus approximated to a substantially straight line in a zigzag shape", when the collision plates (2) are swung, a plane orthogonal to each of the virtual planes (P) is set. When the deflection angle of each collision plate (2) in the upward direction or the downward direction is ψ, the ψ is −45 ° ≦ ψ each collision plate (2)
Is a collision plate (2) with respect to a plane (P ') orthogonal to each of the virtual planes (P) with each swing center axis as the center.
When the deflection angle in the upward direction or the downward direction is ψ, it is preferable to oscillate so that ψ is in the range of −45 ° ≦ φ ≦ 45 °. However, the swing angle (ψ) is, as clearly shown in FIG. 2, half of φ, which is the angle when the tip of each swinging collision plate (2) swings up and down to the maximum, that is, ψ = φ / 2, and the angle formed between each collision plate (2) and each orthogonal plane (P ′) when the collision plate (2) swings upward is represented by minus. The angle when the collision plate (2) swings downward is indicated by a plus sign.

By doing so, it is possible to make the placement locus of the multifilament yarn from a sine curve to a zigzag substantially straight line as much as possible. Here, the deflection angle ψ of the collision plate (2) is −45 °> ψ, or ψ>
Within the range of 45 °, the swing amplitude of each collision plate (2) becomes large, and each multifilament yarn placed on the conveyor net after colliding with each collision plate (2) becomes
It will be greatly swung to the left and right, and it will be difficult to control the mounting locus so that it becomes a zigzag substantially straight line. In addition, the inertia force of the collision plate (2) increases, making it difficult to quickly and quickly switch the swinging direction. In addition, when switching the swinging direction, a large impact force is applied. The above-mentioned unreasonableness arises.

By the way, in FIG. 2, each multifilament group (F) spun from a spinneret group (not shown).
Has been described above in which each ejector (1) picks up and then collides against a swinging collision plate (2) and places it on a moving conveyor net.

On the other hand, as shown in FIG. 4, between each ejector (1) and each swinging collision plate (2b),
It is also conceivable as a preferable embodiment that the other collision plates (2a) that do not swing are fixedly installed. In this embodiment, after the multifilament yarns (F) ejected from the ejectors (1) collide with the fixedly installed collision plates (2a) to spread the fibers, furthermore,
It goes without saying that the opened multifilament yarns are caused to collide with the swinging collision plates (2b), and then spread and placed on the moving net.

Thus, another collision plate (2
By affixing each of the multifilament yarns which are opened by colliding with the oscillating collision plate (2b), if the multifilament yarns are pierced into the conveyor net, This is effective in placing the filament yarn more softly. In addition, each multifilament yarn is caused to collide with each collision plate more,
When it is desired to spread each multifilament yarn, it is preferable to add the non-oscillating collision plate group (2a) as described above.

As described above, as a mode of installing the collision plate (2), a case where a swinging collision plate is provided alone and a case where a fixed collision plate is added in addition to the swinging collision plate are added. There are two possible cases. In addition, these collision plates (2)
May be appropriately selected depending on the type of the polymer. Further, in the case where the polymer that is difficult to be triboelectrically charged or the web spread and placed on the conveyor net is insufficiently spread, it is preferable to use a fiber opening technique such as corona discharge in combination. At this time, the corona discharge device is preferably installed between the ejector and the collision plate installed first.

Next, as means for swinging the collision plate,
A method of combining a cylindrical cam with a link mechanism to swing around a swinging support shaft as the swing center, connecting the number of rotations of a servo motor whose speed is controlled to the crankshaft, or rotating by a rack and a pinion. A method of converting the motion into an amplitude motion and using the converted motion is exemplified.

The placement angle (angle θ in FIG. 2) when the multifilament yarn group is spread and placed on the conveyor net from the swinging collision plate group according to the present invention can be selected appropriately depending on the type of polymer. It is good, but the range of 30 ° to 75 ° is preferable. Further, the contact length of each multifilament yarn at each swinging collision plate is preferably 50 mm or less. If the distance is long, the multifilament yarns tend to adhere to the collision plate, and the uniformity of the basis weight of the placed web is unfavorably reduced.

[0044]

EXAMPLES Hereinafter, the method of the present invention will be described more specifically with reference to examples.

In this example, the unevenness of the sheet was evaluated by the following method.

The CV value (%) in the vertical direction of the web is 25 m in the vertical direction.
By the weight method of m × width 25 mm, the rate of variation (CV) = {σ (standard deviation) / X (average value)} × 10 in the statistical calculation of n = 120
I asked for 0. The horizontal CV value (%) is 250
mm = 25 mm horizontal weighting method, n = 120 statistical calculation (CV) = {σ (standard deviation) / X (average value)} × 1
It asked for 00. The vertical / horizontal strength ratio is 200 from the sheet.
A test piece of mm × width 50 mm was sampled from an arbitrary location, and the tensile strength (kg / 50 mm) was measured in the length / width to obtain the ratio of length / width.

[Example 1] The diameter of each spinneret was 60 mm,
The distance between adjacent spinnerets is 80 mm, and 12 spinneret groups each having 72 spinneret holes are linearly arranged in a row, and polyethylene terephthalate is 1.2 g / min for each spinneret. It was spun at each discharge amount of. As shown in FIG. 2, each spun multifilament yarn is sucked by each ejector (1) at a speed of 4500 m / min, and then collided with each swinging collision plate (2) to cause each collision. The contact length between the plate (2) and each multifilament yarn is 25 mm, and the deflection angle ψ of each collision plate (2) is -45.
Each collision plate (2) was swung with an amplitude of 45 ° to 45 °. At this time, the colliding plate group (2) to be oscillated is moved to a link mechanism that uses a cylindrical cam to make a simple vibration using a center line in the width direction of each colliding plate (2) as a support shaft. And the respective impact plates (2) were swung so that each multifilament thread took a placement locus in a zigzag substantially straight line to the left and right. The swing cycle at this time is 7
It was 50 times / minute.

The long fiber web thus obtained was conveyed by a conveyor net and calendered by an embossing calendar to obtain a sheet having a basis weight of 20 g / m ² . The uniformity of the basis weight and the longitudinal / horizontal strength characteristic ratio of the obtained sheet were evaluated. As a result, the CV value (%) in the longitudinal direction of the web, the CV value (%) in the lateral direction of the web, and the longitudinal / lateral strength ratio were , 6.5%, 6.5%, and 1.8, respectively.

[Comparative Example 1] Until the collision plate is collided,
Under the same conditions as in Example 1, the rocking of the collision plate group is performed by a known rocking means that is a combination of a crank mechanism and a link mechanism, and each multifilament yarn is spread and placed on the conveyor net. did. At this time, the placement loci of the multifilament yarns on the conveyor net were sinusoidal.

The long fiber web thus obtained was conveyed by a conveyor net in the same manner as in Example 1 and calendered by an embossing calendar to give a basis weight of 20 g / m ^2.
Got a sheet of. When the uniformity of the basis weight and the ratio of strength to height / width of the obtained sheet were evaluated, the CV value (%) in the longitudinal direction of the web, the CV value (%) in the transverse direction of the web, and the
The lateral strength ratios were 9.0%, 10.0%, and 2.5, respectively.

A detailed examination of these results revealed that Comparative Example 1 was clearly inferior to Example 1 in terms of uniformity of areal weight and longitudinal / horizontal strength ratio. It will be seen how Example 1 in which the long fiber web was produced is superior in terms of its uniformity of basis weight and its strength / width ratio.

[0052]

As described above, according to the present invention, a multifilament yarn group is taken up by a large number of ejector groups arranged in the lateral direction of the conveyor net, and the taken-up filament yarn group is collided by each collision plate. When the web is spread and placed on the conveyor net that is caused to collide with each other and travels, it is possible to adopt a placement trajectory that reduces the interference between adjacent fibers.
The remarkable effect that the long fiber web excellent in the uniformity of the basis weight and the characteristic ratio of the aspect ratio can be stably produced.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of an apparatus for producing a long fiber web in the present invention.

FIG. 2 is a side view showing an embodiment of a collision plate used in the method of the present invention.

FIG. 3 is a plan view (explanatory diagram) illustrating a placement locus in a state where a multifilament yarn group is placed on a conveyor net in the method of the present invention.

FIG. 4 is a side view showing another embodiment of the collision plate used in the method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 ejector 2 collision plate 3 swing means F multifilament yarn N conveyor net

Claims (5)

[Claims] 1. A multifilament yarn spun from each of the spinneret groups arranged substantially in a line and spun by respective ejectors juxtaposed corresponding to each spinneret. A conveyor that pulls the filament group downwards, collides each multifilament yarn with each collision plate arranged in the yarn ejection direction of each ejector to open the fiber, and then moves the opened multifilament yarn group. In the method for producing a long fiber web by spreading and placing on a net, the trajectory of each center line of each multifilament yarn from the ejector ejected to the collision plate is described. Assuming each virtual plane formed by moving in parallel with the moving direction, the collision plates are synchronized with each other with the virtual center line at which the virtual plane intersects with each collision plate as the swing axis. However, the collision plates are periodically oscillated to the left and right, and at that time, the multifilament yarns which are collided with the collision plates and spread and placed on the conveyor net are placed on the conveyor net. A method for producing a long fiber web, characterized in that each collision plate is caused to perform a swinging motion such that a placement locus becomes a substantially straight line in a zigzag shape. 2. The swing cycle of the collision plate group is 200 to 1
The method for producing a long fiber web according to claim 1, wherein the production rate is 000 times / minute. 3. The production of a long fiber web according to claim 1 or 2, wherein when the collision plates swing, the switching of the swing directions of the swing plates is performed in a short time. Method. 4. When swinging each of the collision plates,
When the deflection angle in the upward or downward direction of each collision plate with respect to the plane orthogonal to each of the virtual planes is ψ, the ψ is −4.
The method for producing a continuous fiber web according to claim 1, wherein the range is 5 ° ≦ ψ ≦ 45 °. 5. Another collision plate is fixedly installed between each ejector corresponding to each of the swinging collision plates and each collision plate, and each ejector is mounted on each fixed collision plate. After the multifilament yarns ejected from each other are collided to open the fibers, the opened multifilament yarns are further collided with the swinging collision plates, and then moved. The method for producing a continuous fiber web according to claim 1, wherein the continuous fiber web is spread and placed on a net.