JPH076126B2 - Manufacturing method and device for unidirectionally arranged nonwoven fabric - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method and an apparatus for producing a non-woven fabric by melting or melting a polymer substance and spinning the polymer substance, in which filaments constituting the non-woven fabric are arranged in one direction. The present invention relates to a method and a device for producing a non-woven fabric.

[Problems to be Solved by Prior Art and Present Invention]

The conventional Suban bond nonwoven fabric has good bulkiness and texture, but since the filaments are arranged almost randomly,
The dimensional stability was poor in the vertical and horizontal directions, and the strength was low.
As means for solving these problems, the present inventors previously disclosed in Japanese Patent Application No. 62-173929 (hereinafter abbreviated as the prior invention) a method and apparatus for stretching a nonwoven fabric in the vertical or horizontal direction, and a vertically stretched nonwoven fabric. We proposed means for laminating warp-stretched non-woven fabrics in the weft direction and means for arranging spun filaments in one direction. The present invention relates to another new invention for producing a non-woven fabric in which the filaments are arranged in one direction, and is an additional patent of the prior invention.

As described in the previous invention, the conventional radam nonwoven fabric, even if it is simply stretched in the vertical direction or the horizontal direction, the entanglement and the adhesion connecting the filaments are often released, and the filament is not stretched. Often does not improve the strength of the nonwoven fabric. Therefore, it was found that by stretching the nonwoven fabric in which the filaments are arranged in one direction in the filament arrangement direction, the filaments are stretched and the strength of the nonwoven fabric is increased. Depending on the type of filaments constituting the non-woven fabric, there are some filaments in which the filaments are simply arranged without stretching, and sufficient strength and dimensional stability can be obtained in the arrangement direction. In the previous invention, since hot air is used to scatter, it is difficult to apply it to the production of a nonwoven fabric by a wet or dry method or emulsion spinning using a solvent or a dispersion medium. Further, in the previous invention, as a means for swirling or vibrating the spun filament first in the width direction, since hot air was also used, the filament does not swirl or vibrate stably depending on the type of polymer substance, Even if hot air was crossed after that, there was a case where it was not stably arranged in one direction.

[Means for solving problems]

As a result of diligent research on these problems, it can be applied to wet spinning, dry spinning, and emulsion spinning, and any spinning filament can be swirled or vibrated stably and scattered in one direction with good alignment. And invented the device.

In a process for producing a non-woven fabric by melt spinning in which a polymer substance is melted, if the spun filament is attempted to be blown off by wind as in the previous invention, the flyout will not occur unless heat is applied above the melting point of the polymer substance. It ’s enough, and there ’s lumps and buds,
There were problems such as small scattering width and insufficient arrangement. There is also a problem in that heat energy is lost when heating a large amount of air, and when hot air is jetted out vigorously, the cold air around it is entrained and the hot air temperature drops. In addition, in order to disperse well, if the spun filament has a low viscosity and a large spinnability, the dispersal is insufficient, but the temperature of the melted polymer to be spun is dependent on the thermal stability of the polymer and the spinning device. There was naturally a limit from the range of heat resistance. As a means for solving the above problems, a fluid for dispersing a filament by dissolving a polymer in a solvent or dispersing it in an emulsion in a liquid (hereinafter referred to as a solution-type spinning solution for the sake of simplicity) and spinning. Also no need to heat. The viscosity of the spinning solution can be freely selected by lowering the concentration of the spinning solution even if a high molecular weight polymer having good spinnability is used.

As a pre-stage for scattering the filaments, the filaments have an amplitude in the range of several mm to several tens of cm, preferably 5 mm to 50 mm, and several tens of times / minute to several hundred times / second, preferably 300 times / minute.
It is necessary to make a turning or reciprocating motion at a cycle of not less than a minute (hereinafter referred to as vibration for simplicity). Another problem of the prior invention is that this vibration depends on the weak hot air near the spinneret, but it is unstable depending on the type and viscosity of the polymer, and stable vibration may not be possible. In the present invention, it has been found that by vibrating the spinneret itself, all the polymers can be melted and even a solution type spinning solution can be vibrated stably regardless of the viscosity. As a result of the experiment, when the amplitude range of vibration is less than 1 mm, the effect of vibrating is not found, and it is desirable that the range is 5 mm or more. Further, it has been found that if the vibration range vibrates over a wide width exceeding 300 mm, the uniformity of scattering cannot be maintained, and it is preferably 50 mm or less. If the cycle of vibration is too slow and is less than 60 times / minute, the productivity of the nonwoven fabric is poor and the accumulation of scattered filaments is insufficient. To form a non-woven fabric, preferably 300 times /
It needs to vibrate for more than a minute. More desirably 30 times /
In the state of turning or reciprocating at a cycle of more than one second (1800 times / minute), the subsequent scattering was stable.

According to the invention of vibrating the solution type spinning liquid or the spinneret itself, as a fluid that vibrates or scatters the filament, not only a heated gas but also an unheated gas,
It has been found that liquids or vapors or gases containing liquids can also be used. Further, in order to give momentum to these liquids, fine powder of a heavy solid or an adhesive solid may be mixed. These liquids may be fluids that aid not only vibration and ratio, but also coagulation and adhesion of the filaments.

As a method of vibrating the spun filament, two methods, that is, a method using air near the spinneret and a method of vibrating the spinneret have been described. As another method, an electric field or a magnetic field may be used, and the polarity of the electric field or the magnetic field may be changed to apply vibration. For example, a high voltage may be applied to the spun filament, and a positive electric field and a negative electric field may be alternately applied to the charged filament to vibrate the spun filament. This method is particularly suitable when a large number of filaments are spun near the spinneret, because the spun filaments are well dispersed without being cohesive. Various methods such as air and vibration of the spinneret and electric charge may be used in combination.

Another feature of the present invention is that the spinneret has a rectangular, elliptical, or irregular cross section such that the filament has an elliptical or irregular cross section deviated from the true circle to facilitate the action of fluid. The point is that it is effective to make the shapes deviated. By using a filament having a cross section deviated from such a perfect circle, even a small amount of low-pressure fluid can disperse and arrange the filaments.

The filament to be spun may be a single filament in the form of a monofilament, but if multiple filaments are simultaneously spun in the form of a multifilament, vibrate at the same time, and are scattered at the same time,
Production efficiency is also good. Further, like the melt-blowing method of a non-woven fabric, it may be jetted together with a gas from the spinneret, and the jetted filament may be vibrated and scattered.

The filament that oscillates to the next scattering has not yet completely solidified and needs to have twice or more draft properties remaining. When solidification is completed at this stage and the draft properties are lost. Experimentally confirmed that, even when the next scattering process was performed, the scattering was insufficient and the sequence was not good. Desirably, when the draft property is 10 times or more, more preferably 100 times or more, the width of the scattered filaments is wide, and the degree of arrangement and the uniformity of arrangement are good. In the case of using the solution type spinning solution, the filament may be vibrated by passing the coagulation bath immediately after spinning and vibrating it at the coagulation bath outlet. In this case, since the drafting property disappears when the solidification is completed,
It is necessary to proceed to the scattering step in a state of at least twice the draft property.

Next, how to apply the fluid that scatters the vibrating filament will be described. There are two ways to do this,
One of them is a method in which a pair of fluids, which are substantially bilaterally symmetrical from the side with respect to a vibrating filament, collide head-on on the filament to cause the filament to scatter in the direction perpendicular to the jet direction of the fluid. Another method is to make a pair of fluids that are substantially symmetrical from the side with respect to the vibrating filament as the center of the crossing in the vibration range of the filament so that the filament is scattered in a direction substantially parallel to the ejection direction of the fluid. Is the way. In this case, the left and right fluids can be jetted intermittently alternately, and the filaments can be scattered in the jetting direction of the fluid, which is also included in the present invention. When the left and right fluids are intermittently ejected, the left and right fluids may be ejected at a focus such that they collide head-on when they are simultaneously ejected. The generation sources of the fluids scattered by these two methods are not limited to one pair, and it is more efficient to install two pairs and three pairs for one spinneret, but in the following description, in order to avoid complexity, A pair will be described. These two methods are detailed in the Detailed Description of the Drawings section.

It is often desirable to stretch or roll the unidirectionally arranged nonwoven fabric of the present invention in the filament arranging direction by the method of the previous invention. The stretching and rolling methods have been described in detail in the previous invention. The unidirectionally arranged nonwoven fabric according to the method of the present invention has a particularly uniform thickness, a good filament arrangement degree, and is less likely to produce lumps or lumps. In the method of the present invention, a unidirectionally arranged non-woven fabric is manufactured, and further, a non-woven fabric arranged in a direction orthogonal to the above-mentioned non-woven fabric by laminating the one-way non-woven fabric is produced, and biaxially arranged in the filament arranging direction of the laminated non-woven fabric. It is also possible to manufacture a cross-woven fabric by stretching the cross-woven fabric. The biaxial stretching in this case may be sequential biaxial or simultaneous biaxial. In either uniaxial stretching or biaxial stretching, it is often suitable to lightly adhere or join the nonwoven fabric before stretching to increase the strength by stretching. It is desirable for the nonwoven fabric to have a strong bond between filaments by adhesion or mechanical bonding after stretching.

Although the unidirectionally arranged nonwoven fabric of the present invention can be used alone, it is generally a nonwoven fabric or a fibrous web arranged in a direction perpendicular to the nonwoven fabric or a fibrous web (for example, yarn or drawn tape arranged at regular intervals, Widened toe,
It is often used in the form of a cross-woven nonwoven fabric in combination with a spun card-like web. The step of combining may be performed on a nonwoven fabric production line or may be performed on another line. The materials to be combined may be the same manufacturing method, and may be a combination of non-woven fabrics arranged in the vertical direction and the horizontal direction depending on the difference in the jetting direction of the fluid. Further, the non-woven fabrics arranged in an oblique direction may be combined so that their arrangement directions are orthogonal to each other. Here, the term “orthogonal” is not limited to the case where the angles strictly intersect with each other at 90 degrees, but may intersect with each other at 30 to 150 degrees.
It is also possible to combine three-dimensional and four-axis non-woven fabrics by combining materials that are diagonally crossed with each other in the vertical or horizontal direction. Further, the materials to be combined are not only materials having the same manufacturing method and different only in the arrangement direction, but also completely different materials, or even if the materials are similar to each other, it is possible to combine materials having completely different manufacturing methods. In terms of balance of physical properties, it is often desirable that the materials to be combined are arranged so as to be orthogonal to the arrangement direction of the filaments of the nonwoven fabric of the present invention. As a method of combining and joining, an adhesive such as powder or emulsion may be used, or mechanical joining such as needle punching may be performed. Further, since the nonwoven fabric of the present invention has a very fine denier, when combined in a nonwoven fabric production line, no adhesive is required and fine filaments can be joined together by combining them. In addition, in the production of the nonwoven fabric of the present invention, filaments having adhesiveness are spun into a large number of spinnerets,
The non-woven fabric itself may contain an adhesive so that it can be bonded to another material only by heating later. In the case of a solution-type spinning solution, coagulation is not completed even after being scattered and accumulated as unidirectionally aligned filaments, and therefore those that still have self-adhesion, use the adhesiveness to bond filaments together. I do.

As one of the effective methods of utilizing the present invention, Japanese Patent Application No. 63-
As an additional invention of No. 61187, it is possible to arrange the filaments in the horizontal direction by the method of the present invention and fix the arrangement of the yarn groups running in the vertical direction by the filaments arranged in the horizontal direction. In this case, the filament is preferably an adhesive polymer. The web in which the running yarn groups are fixedly arranged can be used as a weft web of a warp-laminating machine such as Japanese Patent Publication No. 53-38783.

As the raw material of the nonwoven fabric used in the present invention, polyolefins such as HDPE and PP and polyester, polyamide,
PVC, acrylonitrile, polyvinyl alcohol, polyurethane and other thermoplastic polymers, glass, pitch, adhesive polymers, those dissolved in a solvent, and those that are dispersed in a dispersion with a surfactant to form an emulsion are also used. You can do it. Further, those dissolved in a solvent of a cellulosic polymer, which is difficult to melt-spin, are particularly effective. What is important for these polymers is that the filaments must still be spinnable when vibrated and scattered, and must be capable of drafting tens to thousands of times.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to stably produce a unidirectionally oriented non-woven fabric which has a very narrow stability range by using any polymer with good unidirectional alignment. Therefore, it becomes possible to easily produce the filaments arranged vertically or horizontally even with the solution type spinning solution, and it is possible to form a nonwoven fabric having good dimensional stability vertically and horizontally by combining it with the nonwoven fabric arranged vertically. Further, even a molten polymer having a high viscosity results in well-arranged filaments in one direction, which was particularly suitable for producing a strong nonwoven fabric by stretching in the filament arrangement direction.

[Explanation with drawings]

 Hereinafter, embodiments will be specifically described with reference to the drawings.

FIG. 1 shows an example of the production of the non-woven fabric according to the present invention, in which a molten polymer is introduced into a spinning chestnut group 2-1, 2-2, 2-3 through a flexible conduit 1. These spinning port groups are vibrated in the Y-axis parallel direction of the XYZ axes of the drawing by a driving device (not shown). The spun filament 3-1 vibrates in the width direction at the same cycle as the spinning port. A pair of fluids 4-1a and 4-in the X-axis direction from a position symmetrical about the filament 3-1 vibrating in the width direction.
1b collides head-on on the filament, and the fluid that collided head-on collides with the Y-axis in the horizontal direction.
They are arranged in the axial direction and scattered like 5-1 and accumulated on the conveyor belt running in the X-axis direction. On the conveyor belt, filament groups 7 arranged in the vertical direction, which are previously manufactured by another manufacturing method, are accumulated, and the filaments arranged in the horizontal direction on the conveyor are laminated to form a nonwoven fabric.

FIG. 2 is an example of the arrangement of fluid ejection holes that vibrate the spun filament with a fluid. In FIG. 2A and FIG. 2B, the spinning port is viewed from below, and 8 is the lower plate of the spinning device. Is the spinneret. FIG. A shows an example in which fluid ejection holes 10-1, 10-2, ..., 10-6 are arranged in a straight line around the spinning port 9, and FIG.
Are fluid ejection holes 11-1 and 11- around the spinneret 9 in a circumferential shape.
In this example, 2 ... 11-6 are arranged. In both cases, the fluid may have a component ejected from the spinning port 9 simultaneously with the spinning solution. Further, it is desirable that the fluid ejection holes are formed at a slight angle with respect to the filament spinning direction.

Figure 3 shows an example of how to apply the scattered fluid.
In FIG. A, a pair of fluid jets 13a and 13b, which are symmetrical to the filament 12 from the side with respect to the filament perpendicular to the vibrating direction (X-axis direction), are arranged in the P direction in FIG. When the fluid collides head-on at a position and the colliding fluid scatters in the Y-axis direction, the filament simultaneously scatters to the left and right in the Y-axis direction to form an aggregate 14 of filaments arranged parallel to the Y-axis. In FIG. B, a pair of jets 16a and 16b of fluid are jetted from the X-axis direction to the filament 15 which is also oscillating in the direction parallel to the Y-axis, but unlike the case of A, 16a and 16b are front faces. Without colliding, intersecting at another focal point Q and R on the vibrating filament, the fluid hitting the filament can rush without being disturbed by the fluid coming from the symmetrical position, and the filament scattered by the fluid is It becomes a set 17 of filaments arranged and scattered in the X-axis direction. In A or B, the filaments can be arrayed in any direction depending on the relative relationship between the traveling direction of the conveyor or the nonwoven fabric that accumulates below and the way in which the scattered fluid is applied. Although FIGS. A and B show an example in which the filaments 12 and 15 vibrate horizontally, the filaments 12 and 15 may be swirled in a circular shape.

FIG. 4 shows an example of filament arrangement according to the present invention, in which the direction of the arrow is the vertical direction, and a part of the upper portion of the layer is peeled off so that the structure can be easily understood. (A) is an example in which a layer of filaments arranged vertically and a layer of filaments arranged horizontally are laminated, and a filament in both directions is also an example using the method of the present invention. (B) shows a case where a yarn-arranged filament according to the method of the present invention and a yarn in which the conventional yarns are arranged at a constant pitch in the vertical direction are laminated, and a yarn layer (not shown) may be laminated thereon. (C) is an example in which a layer in which the filaments of the present invention are arranged obliquely and a layer in which the filaments are obliquely arranged and arranged in another oblique direction are laminated. When (C) is obliquely crossed, another non-woven fabric or fiber web in which filaments are arranged in the vertical direction or the horizontal direction may be laminated to form a triaxial or uniaxial non-woven fabric.

〔Example〕

Example 1 The intrinsic viscosity η of polyethylene terephthalate is 0.
72 pellets are melt extruded at 260 ° C. by an extruder and introduced into three spinnerets through a flexible conduit by the method shown in FIG. The spinneret is horizontally parallel to the surface of the paper, and the width is 2400 times with a width of 35 mm
Vibrates in minutes. The spun filament is widthwise
It vibrates in a width of 25 mm at the same cycle as the spinning port. A pair of air heated to 300 ° C. was made to collide head-on in a direction perpendicular to the plane of the paper at a position approximately symmetrical with respect to the filament vibrating in the width direction. With the momentum that the air that collided head-on is scattered in the horizontal direction, the filaments are also arranged in the horizontal direction of the paper surface, and the filaments are arranged in the horizontal direction with a width of about 350 mm per spinneret and scattered, running at a speed of 40 m / min. Collected on the belt. On the conveyor belt, the laterally arranged non-woven fabric with an overall width of about 1000 mm was formed with the laterally arranged filaments from the three spinnerets slightly overlapping the boundary. On the conveyor belt, a non-woven fabric arranged in the vertical direction, which was manufactured by a normal non-woven fabric manufacturing apparatus, was manufactured in the previous step, and was laminated in layers with the filaments arranged horizontally on the conveyor.
The laminated filament group is further laminated with a non-woven fabric whose surface is arranged in the vertical direction, and these layers are bonded by a pair of embossing rollers to form a non-woven fabric. This non-woven fabric is 3.2 times in the vertical direction and 2.8 times in the horizontal direction. Stretch each,
After stretching, the emulsion adhesive was impregnated and dried to obtain a cross-woven fabric. The manufactured non-woven fabric is 35g / m ² , and the vertical strength is 27.2kg.
A non-woven fabric with a width of 5 cm and an elongation of 22% and a lateral strength of 22.5 kg / 5 cm and an elongation of 28%, which is strong against vertical and horizontal, and is 3 to 4 times stronger than a conventional polyester random nonwoven fabric. .

Example 2 A 15% decalin solution of high-density polyethylene was spun out from the nozzle of B in FIG. 2 to obtain filaments arranged vertically in the system of FIG. 3B. In this case, both the vibrating air shown in FIG. 2B and the scattered air shown in FIG. 3B were room temperature air which was not particularly heated. The obtained non-woven fabric was composed of very thin (mostly far smaller than 1 denier) filaments, and it was a non-woven fabric with very good inter-filament adhesion without any particular adhesion. By stretching this non-woven fabric 5 times in the vertical direction by a proximity roller, a non-woven fabric having a basis weight of 15 g / m ² and a vertical strength of 17.4 kg / 5 cm and a vertical elongation of 27% was obtained. This is a non-woven fabric having optimum properties as a raw material web for a weft-laid non-woven fabric.

Example 3 Copper ammonia solution for Rittal valve (concentration 8)
%) Is spun from the spinneret and poured into the funnel at the same time as water to slightly coagulate and stretch, and while the drafting property is still 20 times or more, the exit end of the funnel is 600 times with a width of about 10 mm / Vibrate horizontally in a cycle of minutes, and then eject a pair of water from the vertical direction to the place where the emerging filament vibrates with a force of water to a width of 30 mm (the method of FIG. 3A), The water was collided and the filaments engraved on the side were accumulated on the traveling conveyor belt by the force of the water splashing on the side. The accumulated filaments have not been coagulated yet, but they are layered with the usual method of copper-ammonia cellulose nonwoven fabric (arranged vertically) that is manufactured in the previous step and is deposited on the conveyor and carried. And both were treated with acid to form a vertically and horizontally dimensionally stable nonwoven fabric. In this case, since the coagulation was not yet completed at the time of vertical and horizontal lamination, there was adhesiveness between the filaments and no particular adhesive treatment was necessary.

[Brief description of drawings]

FIG. 1 shows an example of production of the nonwoven fabric of the present invention.
Fig. 2 shows an example of the arrangement of fluid ejection holes when vibrating a spun filament with a fluid. A is an example in which the fluid ejection holes are arranged in a row around the spinneret, and B is an example in which they are arranged in a circumferential shape. Is. FIG. 3 shows an example of how to apply jets of fluid for scattering, where A is a case where the jets collide head-on, and B is a case where they intersect. FIG. 4 shows an example of the arrangement direction of the filaments of the non-woven fabric according to the present invention. (A) is an example of the non-woven fabric arranged according to the present invention in both the vertical and horizontal directions. In this non-woven fabric, an example in which conventional yarns are arranged in the vertical direction, and (C) is an example of a cross-woven non-woven fabric obtained by the method of the present invention. Explanation of main symbols 1 is a flexible conduit for feeding spinning solution 2-1, 2-2, 2-3 is vibrating Spinneret 3-1 is vibrating spinning filament 4-1a, 4-1b The fluid 5-1, which collides head-on, is arranged in a horizontal direction and scattered. 6 is a conveyor belt 7 is a non-woven fabric with vertical alignment 8 is a lower plate of a spinning device, 9 is a spinning port 10-1, 10-2, ... ..10-6, 11-1, 11-2, ... 11-6 are
Fluid ejection holes 12 and 15 for vibrating the filaments are vibrating filaments 13a, 13b, 16a and 16b that cause the vibrating filaments to scatter Fluid jets 14 and 17 are arranged and scattered. Filament group P, Q, R is where the fluid hits the filament

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-49-71263 (JP, A) JP-A-49-85369 (JP, A) JP-B-48-11795 (JP, B2) JP-B-62- 18661 (JP, B2)

Claims (5)

[Claims] 1. A method for producing a non-woven fabric comprising filaments produced by spinning a polymer substance from a spinneret, wherein the spun filaments are spun so as to swirl or vibrate in the width direction, and the swirling or vibrating filaments are still Two
In the state where there is more than twice the draft property, a pair of fluids that are almost symmetrical to the side from one side act on one of the rotating or vibrating filaments, and the filament spinning direction while drafting the filament. A method for producing a unidirectionally arranged non-woven fabric in which the filaments are scattered in the direction perpendicular to and the filaments are arranged in the direction in which they are scattered. 2. The method for producing a unidirectionally arranged nonwoven fabric according to claim 1, wherein a plurality of fluids are collided on one filament. 3. The method for producing a unidirectionally arranged nonwoven fabric according to claim 1, wherein a pair of fluids are intersected with each other in a swirling or vibrating range of one filament. 4. A method for producing a web in which fibers are arranged by stretching the web in which fibers are arranged according to any one of claims (1), (2) and (3) in the arrangement direction. 5. An apparatus for producing a nonwoven fabric having a large number of spinnerets, comprising a spinning filament comprising an apparatus for charging a spinning solution and an apparatus for applying an electric field or a magnetic field for alternately converting the polarity of the spun filament. A device that oscillates in a swirl or width direction, and a pair of fluids that are symmetrical to the left and right are ejected from the side to the center of one of the filaments that are swirling or vibrating, and the fluid flows in a direction perpendicular to the spinning direction of the filament. A unidirectionally arranged non-woven fabric manufacturing apparatus comprising a device for ejecting the liquid to scatter fluid in a direction perpendicular to the spinning direction of the filament.