JP2612203B2 - Fabrication of web with fibers - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a nonwoven fabric by ejecting fibers together with a fluid to form a web arranged in a fixed direction on a conveyor.

[Problems to be solved by the prior art and the present invention]

In the production of conventional nonwoven fabrics, filaments that have been transported in a belt shape by air soccer or the like are collided on a conveyor belt, or bundles of fibers are sucked by a fluid ejector and collide with the conveyor with the force of the fluid. And fell randomly on the conveyor with the force of the collision,
It has been common to produce random nonwovens. These conventional nonwoven fabrics have good bulkiness and feel, but have poor dimensional stability in the horizontal and vertical directions and low strength because the filaments are arranged almost randomly. In order to manufacture a strong nonwoven fabric in the field of civil engineering and construction, which has recently attracted attention in the nonwoven fabric of random arrangement, the present inventors have arranged the fiber directions biaxially in a vertical or horizontal direction like a woven fabric. 3 in combination with non-woven fabric, plus horizontal and oblique
It has been found that a shaft or a four-axis nonwoven fabric is effective. As specific means for these, the present inventors have previously described
No. 36948 and Japanese Patent Publication No. 7-6126 (hereinafter abbreviated as prior invention), a method and an apparatus for stretching a non-woven fabric into a vertical or horizontal direction, a means for laminating a vertical-stretched non-woven fabric and a horizontal-stretched non-woven fabric, and spinning. A means for arranging the filaments in one direction was proposed. The present invention relates to a new invention for producing a nonwoven fabric in which the filaments are arranged in one direction, and is an additional patent of the previous invention.

As mentioned in the previous invention, the conventional random nonwoven fabric,
Simply stretching in the vertical or horizontal direction often causes only the entanglement and adhesion between the filaments to be released, and often does not lead to the stretching of the filament and does not increase the strength of the nonwoven fabric. Therefore, it has been found that by stretching a nonwoven fabric having filaments arranged in one direction in the filament arrangement direction, the filaments are also stretched and the strength of the nonwoven fabric is increased. However, depending on the type of filaments constituting the non-woven fabric, stretching as a non-woven fabric is not necessary, and the constituting filaments are strong, and simply by arranging the filaments, sufficient strength and dimensional stability are provided in the arrangement direction. Some are available. Further, in the prior invention, as a method of arranging the fibers, a method in which the molten polymer is mainly scattered by hot air was used, so that the filaments were sufficiently oriented by drafting or drawing, or the short fibers obtained by cutting the filaments, and wet spinning. It could not be used for filaments. Accordingly, there has been a long-felt need for a web production method that can freely control the arrangement direction of fibers with any fiber.

As a conventional technique, a method of arranging fibers in a horizontal direction by blowing different air alternately in the ejector for this purpose (Japanese Patent Publication No. 45-10779), or mechanically controlling the filament exiting the ejector USP 3,293,7 to judge
There is also No. 18, but with these methods, the line speed could not be increased and the technology could not be mass-produced.

[Means for solving the problem]

As a result of intensive research on these problems,
It can be applied to melt spinning, wet spinning, dry spinning, and emulsion spinning.Also, filaments that have already been oriented by drafting or drawing, unoriented filaments, and those short fibers can be used to stably align a web in a certain direction. The inventors have invented a method and an apparatus for forming.

The basis is a nonwoven fabric manufacturing method and apparatus in which fibers are spouted together with a fluid to accumulate on a conveyor, and a special action is given to the conveyor or the periphery thereof, and a valley or groove is formed on the conveyor or the collection body, and the valley or It was confirmed that the object could be achieved by arranging the fibers along the fluid flowing along the grooves. The concrete means are roughly divided into four. The first is a method in which fluid is scattered in the direction of a curved groove because the conveyor is curved in a certain direction instead of a plane, and the fibers are arranged in the direction in which the fluid is scattered to form a fiber-arranged web. It is. For example, when a part of the conveyor belt is slackened to create a groove in the horizontal direction, and the fiber is ejected with the fluid into the groove, the fluid flows in the direction of the groove, and the fiber flows along the flow, and the conveyor flows. An aggregate of fibers lined up in the groove direction is formed. In this case, the conveyor belt often uses a porous conveyor such as a screen mesh.

The next method is to plant a large number of blades (pins with a large width and a small thickness) on the conveyor and scatter the fluid that has collided with the conveyor in the direction of the groove formed between the blades. The fibers are arranged in the direction in which they are scattered, forming an aggregate of fibers arranged on a conveyor. The blade shape and the like will be described in detail in the detailed description of the drawings.

The third means is to provide a barrier just above the conveyor with a little space, such as solids, fluids, electric and magnetic fields, and to scatter the ejected fluid in a direction that does not have the barrier. The fibers are arranged in the direction in which the fibers are arranged, and an aggregate of fibers arranged on a conveyor is produced. Solid walls often use plates. The fluid can also form the walls with an air curtain, a liquid curtain, or a jet of fluid. The electromagnetic field will be described later.

The fourth means is that the fluid ejected from the ejector is ejected to the groove of the collecting body having a curved and grooved inner surface before being put on the conveyor, and the fluid is scattered in the direction of the groove. By arranging the fibers in the direction and transferring the arranged fibers to the conveyor by the flow of fluid,
Make a web stack of fibers arranged on a conveyor. The direction of the groove is inclined from 30 degrees to 90 degrees with respect to the traveling direction of the conveyor. Below 30 degrees, most of the fluid scatters in parallel to the conveyor, which is no different from a simple plate. The U-shaped or V-shaped cross section of the groove has a horizontal structure, and the line below the cross section must be a horizontal or downward slope groove with respect to the conveyor. is there. By this means, if the fluid is a liquid, this fluid also helps to transfer the fibers arranged on the collection body to the conveyor. If the fluid is a gas and does not transfer smoothly from the collection body to the conveyor, it is possible to supply another liquid to the collection body and transfer the liquid to the conveyor by the flow of the liquid. In the past, there were cases where such a collection body or collection plate was used, but all of them aimed at opening the fiber, thereby weakening the momentum of the fluid of the ejector and dispersing the fluid, This is intended to improve the opening property between filaments while making the filaments vertical or random. In the present invention, since the fluid flows in the direction of the groove of the collecting body, the fibers that are inclined at least 30 degrees with respect to the traveling direction of the conveyor are the main components. It is also desirable to vibrate the collector so that the dispersion of the fibers is improved.

As a method for supplying the fiber of the present invention, a nonwoven fabric manufacturing method has been used conventionally. The method of sucking the fiber supplied in a wide band shape by air soccer is not desirable. In the present invention, it is desirable that the fibers supplied in a narrow bundle are sucked and supplied from a high-speed fluid ejector.

As the ejector used in the present invention, a normal ejector can be used, but it is preferable that the outlet of the ejector is an ellipse, a rectangle, or a rhombus whose major axis is a direction in which fibers are to be arranged.

In the present invention, as the fluid to be used, when it is desired that the ejected fibers be taken out as unoriented filaments (when post-stretching is desired), hot air is optimal, and it is preferable to carry out at a temperature higher than the melting point of the filaments. When drafting with an ejected fluid to obtain a strong fiber, ordinary room temperature air may be used in melt spinning or dry spinning, and a coagulating liquid can be used as a fluid in wet spinning. Also, liquid vapor may be used. Further, oil, an agent for imparting weather resistance, an adhesive for imparting adhesiveness, and the like may be mixed into the fluid.

When the flow rate of the fibers ejected together with the fluid is ejected from the conveyor belt at a high speed of at least one digit or more, desirably at least two digits, the fibers are well arranged and the formed web has little unevenness in thickness. As the type of fiber, multifilament, monofilament, split yarn, tape yarn, aggregate of short fibers, tow, roving, sliver, and the like are used. In some cases, an irregular cross-section in which the fiber cross-section is deviated from a perfect circle is more likely to be affected by a fluid.

In these means, the experimental results also confirmed that if the flow of fibers ejected together with the fluid vibrates or swirls to a certain width, the fibers are well arranged and a uniform web is formed. For example, when arranging fibers in a direction perpendicular to the traveling direction of the conveyor (horizontal direction), if the ejected fibers are not vibrating or turning, even if the fibers tend to scatter only in the left direction if the fibers are left, When oscillating or turning, it scatters equally on the left and right,
The arrangement of the fibers is also significantly improved. It is effective to vibrate or rotate the ejector as a means for vibrating or turning. It is desirable that the cycle of vibration and rotation be several tens or more times per second. As another means for oscillating the flow of the ejected fiber, a pair of fluids that are substantially symmetrical from the side are acted on the filament spun in a state of being vibrated or swirled to a fixed width according to the previous invention. Experimental results also confirmed that the fibers were widely aligned and vibrated when the method was used.

The fiber stream ejected together with the fluid may reach the conveyor after exiting the ejector, colliding with a flat or curved collision plate. The collision results in a stream of fibers that spread slightly across the horizontal, generating static electricity, and is often convenient for the arrangement of the present invention. Further, by vibrating the collision plate, it is possible to improve the fiber opening between the fibers. However, the present invention requires that after collision, the majority of the fluid and the fibers collide on the conveyor or collection.

When the flow of the fibers ejected together with the fluid is charged, the fibers are well dispersed, which is effective in reducing unevenness in the density and thickness of the web. This is particularly effective when the ejected fibers are multifilaments or aggregates of short fibers. As a means for charging, a high voltage can be applied to the spinning solution, or corona charging or frictional charging can be applied to the fiber. When the ejected fibers are charged, when providing a barrier on the conveyor, the charged barrier is effective as the barrier. If the fiber is negatively charged, the barrier also uses a negative charge. However, in some cases, it is effective to keep the conveyor positively charged. As a barrier,
A magnetic field can also be used.

When using a conveyor, if the surface of the conveyor is completely flat, the fibers that have been arranged are often disturbed by the force of the ejected fluid. The experimental results also confirmed that the dislocation of the fibers could be reduced by planting.

Earlier, it was mentioned that the ejected fibers are vibrated and swirled, but it may be effective to vibrate the conveyor.

By using a porous material that allows fluid to pass through as a conveyor, and by letting the ejected fluid pass through the back of the conveyor, the degree of scattering of the fluid on the conveyor can be controlled. They are accumulated on the conveyor without disturbing the arrangement. As the porous substance, a mesh-like substance such as a screen mesh is generally used. Controlling the strength of the fluid passing through the conveyor can be controlled by the degree of the material of the conveyor or the degree of the porous material, but when the speed is increased or the weighing of the web is variously changed, changing the conveyor is Inconvenient. Therefore, in general, a negative pressure zone is provided below the conveyor, and the speed of the fluid passing through the conveyor can be adjusted by adjusting the degree of the negative pressure. When arranging the fibers of the present invention, by providing a long negative pressure zone in the arrangement direction of the fibers, the fluid flows in that direction,
Thereby, the arrangement of the fibers is improved.

The unidirectionally arranged nonwoven fabric of the present invention is obtained by the method of the present invention.
It is often desirable to stretch or roll in the direction of filament arrangement. In this case, it is desirable that the fibers are not oriented and are not yet drawn. The stretching and rolling methods have been described in detail in the preceding invention. The unidirectionally aligned nonwoven fabric according to the method of the present invention is a nonwoven fabric that is particularly suitable for stretching since it has good uniformity in thickness, good degree of filament arrangement, and hardly generates lumps or lumps. In the method of the present invention, a unidirectionally arranged nonwoven fabric is manufactured, and further, a nonwoven fabric arranged in a direction perpendicular to the nonwoven fabric in a form of being integrated thereon is manufactured. Orthogonal nonwoven fabrics can also be produced by stretching. The biaxial stretching in this case may be sequential biaxial or simultaneous biaxial. In both uniaxial stretching and biaxial stretching, lightly bonding or joining the nonwoven fabric before stretching is often suitable for increasing the strength by stretching. After stretching, it is desirable for the nonwoven fabric to be strongly bonded between filaments by bonding or mechanical bonding.

Although the unidirectionally arranged nonwoven fabric of the present invention can be used alone, it is generally used as a nonwoven fabric or a fibrous web (for example, one in which yarns or drawn tapes are arranged at regular intervals) arranged in a direction perpendicular thereto. In many cases, the cross-linked nonwoven fabric is used in combination with a widened tow, a carded web formed by spinning, or the like. The combining step may be performed on a nonwoven fabric manufacturing line or on another line. The material to be combined may be a nonwoven fabric arranged in the vertical direction and the horizontal direction only by the difference in the ejection direction of the fluid by the same manufacturing method. Also, nonwoven fabrics arranged in an oblique direction may be combined so that the arrangement directions are orthogonal to each other. Here, the term “orthogonal” means not only the case where the angle intersects exactly at 90 degrees, but also the case where the angle intersects at 30 to 150 degrees. It is also possible to make a triaxial or quadriaxial nonwoven fabric by combining materials obliquely with materials arranged in the vertical or horizontal direction. In addition, the material to be combined is the same manufacturing method,
Not only materials that differ only in the arrangement direction, but completely different materials,
Further, even if the materials are similar, they can be combined with completely different materials. In view of the balance of physical properties, it is 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 joining in combination, an adhesive such as powder or emulsion may be used, or mechanical joining such as needle punching may be performed. Since the nonwoven fabric of the present invention can be made very fine denier, if it is combined on a nonwoven fabric production line, no adhesive is required, and bonding by entanglement of fine filaments is possible. Immediately after spinning, it may be possible to adhere only by embossing.
Also, in the production of the nonwoven fabric of the present invention, a filament having an adhesive property is spun into a large number of spinnerets, an adhesive is contained in the nonwoven fabric itself, and then other materials are simply heated. Can also be joined. In the case of a solution-type spinning solution, even after being scattered and accumulated as a unidirectionally arranged filament, coagulation is not completed. Perform bonding.

One of the effective methods of using the present invention is
As an additional invention of -55582, it is possible to arrange the filaments in the weft direction by the method of the present invention and fix the arrangement of the yarn group running in the vertical direction by the filaments arranged in the weft direction. In this case, the filament is desirably an adhesive polymer. The web in which the arrangement of the running yarn groups is fixed can be used also as a weft web of a weft laminating machine such as Japanese Patent Publication No. 53-38783.

The raw material of the web used in the present invention is HDPE
Fibers of thermoplastic polymers such as polyolefins such as PP and PP, polyesters, polyamides, PVC, acrylonitrile, polyvinyl alcohol, polyurethane, and polyimide. In addition, inorganic fibers such as glass fiber, carbon fiber, and alumina fiber. Fibers mainly for bonding such as pitch and adhesive polymer. Fibers made with a solvent such as cellulose or Kevlar fiber can also be used. Natural fiber,
Cotton, hemp, silk, wool, asbestos and the like can be used regardless of long fibers or short fibers.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to stably produce a unidirectionally oriented nonwoven fabric having a very narrow range of stability with any polymer and with good unidirectional alignment. For this reason, it became possible to easily produce filaments arranged in a vertical or horizontal direction even with a solution-type spinning solution, and in combination with a nonwoven fabric arranged in a perpendicular direction as it was, a nonwoven fabric with good dimensional stability in a vertical and horizontal direction could be obtained. . Further, even a molten polymer having a high viscosity results in filaments which are well arranged in one direction, which is particularly suitable for producing a strong nonwoven fabric by stretching in the direction in which the filaments are arranged.

[Explanation by drawing]

Hereinafter, examples of the embodiments will be specifically described with reference to the drawings.
FIG. 1 shows an example of the production of a nonwoven fabric web according to the present invention, in which needles are densely planted in the form of clothing on the surface of a circulating conveyor belt 1 made of a screen mesh.
The length of the needle is as short as 1 mm. The belt 1 is guided to cylinders 2-1, 2-2, 2-3, and 2-4 that rotate at a constant speed. Both ends of the belt 1 are chained, and a chain (not shown) is provided at both ends of the cylinder. The belt is slackened between the cylinders by the chain and the wheel so that the belt travels between the cylinders in the running direction of the conveyor. The groove is formed so as to bend vertically and downward. The web 3 in which the fibers are arranged in the vertical direction (the flow direction of the line) manufactured in another process is first carried on a belt.
The grooves formed between the cylinders 2-1 and 2-2 allow the fibers to be ejected at high speed together with the fluid by the ejectors 4-1 4-2, 4-3,.
・ Squirted more. By oscillating the tip of the ejector horizontally, the fluid ejected from the ejector is oscillated by 20 to 30 mm in the horizontal direction. There is some resistance for the fluid to pass from the belt, so the fluid flows along the grooves. The ejectors arranged in the same groove are arranged so far that the fluids flowing along the groove do not interfere with each other.
The ejectors arranged in the subsequent grooves do not overlap with the preceding ejectors in the line direction so that the fiber density is uniform in the width direction. Negative pressure chambers 5-1, 5-2, and 5-3 are provided in the width direction on the back of the grooved belt 1 so that fluid flowing into the width is removed more rapidly than the belt, and fibers are fixed to the belt. Play a role. At this time, the fibers are arranged in the flow direction of the fluid (horizontal direction) and fixed on the conveyor. Since the vertical alignment web 3 is gripped by the needle cloth of the belt 1, the vertical alignment web 3 is in close contact with the belt 1 without being swept away by the force of ejecting the fluid of the ejector or the force of the fluid flowing along the groove. Between cylinders 2-2 and 2-3, 2-3 and 2-
Fibers are similarly fixed on the belt in the grooves between the four. In this way, the vertical web can be further laminated during or after the horizontal web is laminated. The vertical web and the horizontal web are peeled from the belt 1 and the emboss roller 6
At the same time as embossing at -1, 6-2, the vertical web, the horizontal web, and the fibers constituting the web are bonded to each other, and are taken rearward as the web 7 in which the fibers are arranged in the vertical and horizontal directions.

FIG. 2 shows an example of a cylindrical conveyor. On the cylindrical conveyor 8, a number of thin blades having a length of 10 to 20 mm, a thickness of 0.3 to 1 mm, and a height of 2 to 3 mm protruding on the conveyor are inserted in the horizontal direction with respect to the rotation direction of the conveyor. The blades are planted so that the spacing between the blades is 2 to 5 mm and the arrangement of the spacing is staggered. The cylindrical conveyor 8 is made of a mesh-like porous sheet, and has a negative pressure chamber 5-1 inside the cylinder.
5-2 and 5-3 are provided long in the horizontal direction, and serve to rapidly remove fluid flowing along the blade to the horizontal from the conveyor. On the surface of the place where the negative pressure chamber of the conveyor 8 is located, fibers are ejected together with fluid from a large number of ejectors. As in the case of FIG. 1, the ejectors are arranged such that they do not interfere with each other in the horizontal direction and the fiber density is uniform in the vertical direction. The fluid ejected from the ejector flows along the groove formed by the blade, and the fibers are arranged along the flow of the fluid.

FIG. 3 is a side view of the device, showing a conveyor belt 9 circulating at an angle and a barrier 10 on the rising slope of the belt.
Fibers are ejected from a large number of ejectors together with fluid into a groove formed by -1, 10-2, and 10-3. When the ejected fluid is a liquid, the angle and speed of the conveyor 9 are determined so that the tendency of the liquid to rise upward at the speed of the conveyor 9 and the tendency of the liquid to fall downward by gravity are balanced. Negative pressure chambers 5-1, 5-2, and 5-3 are provided in the horizontal direction on the inside of the conveyor at a location where a groove formed by the conveyor 9 and the barrier 10 is provided. A vertically arranged web 11 is guided from below the conveyor, and moves upward with fibers arranged in a horizontal direction.

FIG. 4 is a side view of the collecting body. The groove on the inner surface of the collecting body 12 whose inner surface is curved to form a groove has a U-shaped horizontal structure. It is inclined 30 to 90 degrees to the 13 traveling directions. By the ejector 4,
The fluid and the fibers injected into the groove scatter in the direction of the groove, and the fibers are arranged in the direction of the groove. The fluid that has scattered and loses momentum flows out of the groove to the conveyor 13. In this case, the underline of the cross section of the groove is made horizontal or downhill with respect to the conveyor to smoothly transfer the arranged fibers to the conveyor (the angle α in the figure is in the range of 0 to 90 degrees). . In this case, since the fluid is a liquid, the transition is smooth, so if the ejected fluid is a gas, another liquid flows into the groove,
The transition to the conveyor can be smooth. It is also possible to form a laminated web by placing another web on the conveyor in advance.

FIG. 5 shows an example of the suction port of the negative pressure chamber.
Is provided in the horizontal direction along the groove with respect to the traveling direction of the conveyor 15 (FIG. A). More preferably, the position of the groove in FIG. Thus, the suction port 16 of the negative pressure chamber is slightly V-shaped.

FIG. 6 shows an example of an oriented web, and FIG. 6 shows an example in which a vertical web a and a horizontal web b are joined. FIG. 2B is an example of an oblique web. In FIGS. 1 to 5, the fibers ejected from the ejector are illustrated in a case where they are arranged horizontally, but the fibers are obliquely oriented by setting the direction of the grooves to be oblique with respect to the traveling direction of the conveyor. Web c
Can be manufactured. The obliquely oriented web c and the web d arranged in a symmetrical direction with respect to the traveling direction (vertical direction) of the conveyor manufactured in the same manner are laminated to form an oblique web. This is shown as an example of a triaxially arranged web by laminating a web a in a vertical arrangement. If the weft-arranged web is joined to FIG.

[Brief description of the drawings]

FIG. 1 shows that the conveyor belt is curved to form a groove,
FIG. 2 shows an example of manufacturing a weft-arranged web, and FIG. 2 shows a weft-arrangement by providing a number of blades having a wide width on a conveyor and flowing a fluid ejected from an ejector along a groove formed by the blades. The example of the web manufacturing apparatus was shown. FIG. 3 is a side view showing an apparatus for producing a transversely oriented web by ejecting fibers into a groove formed by an inclined conveyor belt and a barrier. FIG. 4 is a side view of an example of the collection body. FIG. 5 shows an example of a suction port of a negative pressure chamber used in the present invention. FIG. 6 shows an example of a fiber array web produced according to the present invention. Explanation of main symbols 1 is a circulating conveyor belt. 2-1, 2-2, 2-3 and 2-4 are rotating cylinders. 3 is a vertical array web. Reference numerals 4, 4-1, 4-2, 4-3, etc. denote ejectors for ejecting the fibers together with the fluid. 5-1, 5-2, and 5-3 are negative pressure chambers. 6-1 and 6-2 are emboss rolls. Reference numeral 7 denotes a web in which a vertical alignment web and a horizontal alignment web are laminated. 8 is a cylindrical conveyor cylinder. 9, 13, and 15 are conveyors. 10-1, 10-2, and 10-3 are solid barriers. 11 is a vertical array web. 12 is a curved aggregate on the inner surface. 14 and 16 are suction ports for the negative pressure chamber. a is a vertical array web. b is a horizontal alignment web. c and d are obliquely arranged webs.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-177271 (JP, A) JP-A-62-170570 (JP, A) JP-A-59-94660 (JP, A) 6513 (JP, A) JP-A-54-138667 (JP, A) JP-A-52-118069 (JP, A) JP-A-49-100374 (JP, A) JP-A-49-85369 (JP, A)

Claims (3)

(57) [Claims] In a continuous web production method in which a bundle of fibers is sucked by a high-speed fluid ejector and jetted onto a conveyor belt, at least a part of a conveyor belt parallel to a plane is moved in a direction perpendicular to a running direction. In addition, by causing a downward curve, the ejector ejects a fluid and fibers from the ejector to the bottom of the curve, and scatters the fluid in the direction of the curved groove, thereby arranging the fibers in the direction in which the fibers are scattered. Web recipe. 2. A continuous web production method in which bundles of filaments comprising filaments having substantially no molecular orientation are sucked by a high-speed fluid ejector and jetted onto a conveyor belt. Provide a barrier for electric and magnetic fields, block the flow of fluid in the direction of the nonwoven fabric by the barrier, and form a groove consisting of the barrier and the conveyor so that the ejected fluid escapes in the direction perpendicular to the traveling of the conveyor. A method for producing a web in which fibers are arranged by causing fibers to be arranged horizontally in the direction of travel of the web by scattering and stretching in the direction of arrangement. 3. In a continuous web production method in which a bundle of fibers is sucked by a high-speed fluid ejector and ejected onto a conveyor belt, a flow of fibers ejected together with the fluid is caused to collide with a concave or V-shaped groove. A method of producing a web with fibers arranged in a horizontal direction by arranging the filaments in a groove horizontally and then transferring the filaments to a conveyor or a collecting body.