JP2001271259A - Multiaxial tow laminated nonwoven fabric and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven fabric which has large strengths and breaking energies in many directions and can be produced at a low cost, to provide a nonwoven fabric suitable in the uses of three-dimensional moldings, geotextiles, roofing base fabrics, and so on, and to provide a method for producing the same. SOLUTION: This multiaxial tow laminated nonwoven fabric obtained by laminating and bonding tows having crimps, a total tex of <=30,000 and a single filament tex of <=3 as a constituting raw material, and the method for stably producing the multiaxial tow laminate nonwoven fabric having a good quality, characterized by performing a thermal treatment or a joining treatment such as a needle-punching treatment in a state that the mutually obliquely crossed tows are held with the pins of the laminating device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonwoven fabric having a large basis weight and strong in all directions, and relates to a nonwoven fabric used for three-dimensional molded articles, geotextiles and the like.

[0002]

2. Description of the Related Art As one use of geotextiles, textiles have been conventionally used in fields requiring strength such as embankment and reinforcement of soft ground. However, thick fabrics have a low production rate and use yarns, which increases costs. Also, in terms of physical properties, the strength of the vertical and horizontal is strong, but the strength in the 45 degree direction is weak, and it is not always suitable for geotextiles that require strength in all directions, so use a woven fabric thicker than necessary. And the cost was increased. For the purpose of improving this point, a four-axis woven fabric has also been developed (Japanese Patent Laid-Open No. 1-292140), and is also being studied as a geotextile (Maruzen: Handbook of Industrial Textile Materials, 1994, p376).

[0003]

However, these four-axis woven fabrics have lower productivity than ordinary looms, resulting in an increase in cost and are not suitable for geotextile or the like where cost is an important factor. In addition, since the woven fabric has strength, but the elongation is small, the breaking energy of strength × elongation is not necessarily large, and a nonwoven fabric having a large rupture elongation has been required. As another important use of geotextile, when used for the purpose of sucking out, filtering, and draining water, water permeability is required as an important property. Conventionally, spunbonded nonwoven fabrics and short fiber nonwoven fabrics have been used in this field. However, spunbonded nonwoven fabrics have a fiber diameter of 25 to 30 microns and are thick, and the water permeability utilizing the capillary action of fibers is not necessarily large. On the other hand, a spunbonded nonwoven fabric having a small fiber diameter has poor productivity and increases cost. Spunbond has a filament strength of 20 m.
Weak at about N / tex. Further, since the arrangement of the filaments is also random, it is inefficient to use the capillary phenomenon. The short fiber non-woven fabric has a fiber strength of 100 to 20.
Although the strength is as low as 0 mN / tex, the strength of the nonwoven fabric depends on the entanglement strength of the fibers and is extremely small because it is a short fiber. Also,
Since the arrangement of the fibers in the nonwoven fabric is also random, the water permeability is not efficient. An object of the present invention is to provide a nonwoven fabric which has solved these problems. Although the above has been described with reference to geotextile as an example, as will be described later, it is also used to solve the conventional problems in fields requiring high strength and high breaking energy such as roofing base fabric, carpet, flexible container and the like. Can be

[0004] The inventors of the present invention attempted to improve the weakness of conventional woven fabrics and orthogonal nonwoven fabrics in the 45-degree direction by oblique triaxial axes.
Development of multi-axial laminated non-woven fabric such as 4-axis
54904, Tokuhei 1-29043, Tokuhei 3-809
No. 11, JP-A-8-209518). However, since these were laminates made of yarn, only a coarse structure could be realized, and a product having a large basis weight had poor productivity. Furthermore, these prior inventions are costly because the adhesion between the yarns is dependent on the adhesive, and in general, bonding with the adhesive has a weak adhesive strength and the adhesive has no heat resistance, so that it is difficult to use the adhesive. Often there were restrictions. An object of the present invention is to provide a nonwoven fabric which has solved these problems.

[0005] In the plastics industry, a plastic sheet is deep drawn by thermoforming or the like to produce a three-dimensional molded product. Since the woven fabric does not have thermoformability and has a small elongation, deep drawing cannot be performed. Some nonwoven fabrics have thermoformability (JP-A-60-199957, JP-A-60-199961, and JP-A-8-2915457).
issue). However, these are composed of filaments having a small molecular orientation, and the resulting products have low strength and small dimensional stability. Further, since these are based on spunbonded nonwoven fabric technology, productivity was low in order to obtain a product having a large basis weight. Therefore, there is a need for a material that can be used for automobile seats and ceiling materials, office chairs, and the like, and that can produce a three-dimensional molded product by a three-dimensional molding process with a large basis weight and a tactile sensation, such as cloth, at low cost. Another object of the present invention is to provide a nonwoven fabric that solves these problems.

[0006] In the present society, the problem of treating waste plastic such as PET bottles has become a major social problem not only in the plastics industry but also in the administrative and distribution industries. An object of the present invention is to provide a nonwoven fabric that has important social significance by using this waste plastic as a raw material resin, opening up a large-scale use of geotextiles and the like, and effectively utilizing waste plastic.

Usually, in the production of tow, a spun undrawn tow is placed in a box (Kens, Can). Then, unstretched tows are unreeled from a large number of boxes and are stretched and crimped to produce tows as products, or are directly processed into short fibers after crimping. In such a process, a number of boxes for storing the spun undrawn tow and a number of boxes for feeding out to the drawing process are required, and the tow manufacturing factory has a feeling that these boxes are filled up, and the space for the factory is limited. Is inefficient. An object of the present invention is to provide a nonwoven fabric which has solved these problems. Conventionally, a tow widening nonwoven fabric has been invented by widening a tow to form a thin web and laminating and bonding the web (Japanese Patent Publication No. 53-38883).
However, widening of the tow is not always efficient, and is effective for a nonwoven fabric having a small basis weight, but is not efficient for a nonwoven fabric having a large basis weight or a multidirectional strong nonwoven fabric, which is the object of the present invention. In addition, the orthogonal nonwoven fabric formed by toe widening cannot be expected to have multidirectional strength. An object of the present invention is to provide a nonwoven fabric which has solved these problems.

[0008]

Means for Solving the Problems The present invention has intensively studied to solve the above problems, and as a result, has reached the following solving means. In the present invention, the constituent filament is 3te
The present invention relates to a multiaxial tow laminated nonwoven fabric having a layer in which a plurality of tows having a crimp of x or less and a total tex of 1,000 to 30,000 are arranged in parallel. Further, the present invention relates to a tow multiaxial laminated nonwoven fabric in which the above-described multiaxial tow laminated nonwoven fabric is bonded between layers by at least one of the following means. Needle punch, stitch bond, ultrasonic bonding, water jet, through air. Further, the present invention provides a multi-axial tow laminated nonwoven fabric as described above, wherein the multi-axial tow laminated nonwoven fabric has a 50
The present invention relates to a multiaxial tow laminated nonwoven fabric having a strength at 10% elongation of 10 mN / tex or more. Furthermore, the present invention provides the multiaxial tow laminated nonwoven fabric, wherein the multiaxial tow laminated nonwoven fabric includes a conjugate fiber or a mixed fiber made of different polymers having different softening points and bonded by hot embossing or thermocompression bonding. About. Furthermore, the present invention relates to a three-dimensional molded product three-dimensionally molded from the multiaxial tow laminated nonwoven fabric. Further, the present invention relates to a tow wherein the bonding between filaments or the heat treatment of the web is performed after the tow multiaxial laminating step, in a state where both ear ends of the oblique members of the multiaxial laminate oblique to each other are held by pins. It relates to a method for producing a multiaxial nonwoven fabric. Further, the present invention provides a multiaxial tow laminated nonwoven fabric comprising a conjugate fiber or a mixed fiber made of different polymers having different softening points, and the multiaxially laminated nonwoven fabric is subjected to three-dimensional molding by three-dimensional molding. And a method for producing a three-dimensional molded product made of a tow laminated nonwoven fabric by heat-treating at a temperature equal to or higher than the lower softening point of the different polymer constituting the three-dimensional molded product.

In the present invention, the multiaxial laminated nonwoven fabric, ie, 3
A laminated nonwoven fabric manufactured by a manufacturing technology of an oblique laminated nonwoven fabric such as an axis, an axis, an axis, and an axis is used. These nonwoven fabrics are characterized by containing oblique materials unlike woven fabrics and orthogonal nonwoven fabrics. With triaxial nonwoven fabric or triaxial laminated nonwoven fabric,
A nonwoven fabric in which oblique materials in two directions crossing each other in the opposite directions are laminated and joined to a constituent vertical (warp) material. Further, the nonwoven fabric may be a nonwoven fabric in which oblique materials in two directions crossing each other in the opposite directions to the weft (weft) material are laminated and joined. 4
The axial nonwoven fabric or the four-axis laminated nonwoven fabric refers to a nonwoven fabric obtained by laminating and joining two-way oblique materials that intersect with each other in the vertical (warp) and transverse (weft) materials. 5
The axial nonwoven fabric is a case where oblique materials that intersect with each other in a direction opposite to the vertical material are changed in angle to form a combination of two sets of oblique materials. In these multiaxial nonwoven fabrics, the length is counted as one axis, but it is also possible to arrange the length on the front and back. The multiaxial laminated nonwoven fabric is disclosed in Japanese Patent Publication Nos. 62-54904, 1-24903, and
JP-B-3-80911, JP-A-8-209518, and the like are used, but the invention is not limited to these, and any nonwoven fabric may be used as long as a vertical material, a horizontal material, and an oblique material are laminated and joined.

In the present invention, tow is used for at least a part of the vertical, horizontal and oblique materials. Tow is J
The IS fiber term is defined as "a kind of spinning raw material and a bundle with a very large number of filaments", and the tow in the present invention is also used in the meaning of such "a bundle with a very large number of filaments". In addition, the filament is
Fine fibers that are essentially continuous or semi-continuous, and are distinguished from short fibers that are about 80 millimeters or less. The use of the tow is not possible with a conventional multi-axial laminate using yarns, only a rough structure can be realized, and the productivity of a product having a large basis weight is poor. In the present invention, by using tow as a raw material as it is, a nonwoven fabric having a high fiber density and a large basis weight can be realized, and a nonwoven fabric most suitable for geotextile and the like can be obtained. Conventionally, there is no technology to convert tow directly into sheets.
A thick nonwoven fabric having a strong basis weight distribution in all directions could not be obtained. Conventionally, short fiber non-woven fabrics have been used, but short fiber non-woven fabrics require extra steps, such as cutting the tow and placing them on a card. It has a drawback that it cannot be utilized for the above and depends on the strength of the joint. On the other hand, the present invention is 350-450 m
By directly using a tow made of a filament having a high strength of N / tex, such a problem can be overcome.
A thick nonwoven fabric with low cost, strong in multiple directions, and uniform basis weight distribution was realized.

When tow is used as a raw material for ordinary spinning, tow having a tex of 50,000 to hundreds of thousands of tex is used. However, the tow used as the oblique material of the present invention is from 1,000 tex to 30,0.
00 tex, from 2,000 tex to 25,000
tex is particularly desirable. Too big total
x is difficult to handle as an oblique material, and several hundred te
Below x, industrial yarns are widely used, so there is no point in using tows, and tows with a small total tex rather increase costs in production. When using tow as vertical wood,
Large tows with x of 30,000 to 50,000 tex can be used, and in some cases, by using a widened tow, 1
A tow of more than 10,000 tex can also be used. The tex of the filament constituting the tow used in the present invention is:
It is desirable to be 3 tex or less and 1 tex or less. Three
With a single yarn tex exceeding tex, the web may not be sufficiently entangled with a bonding method that does not use an adhesive such as a needle punch, and may not have sufficient bonding strength.

The tow used in the present invention is not limited to a production method for producing so-called short fibers.
It can also be produced by drawing a filament spun from a spun bond die, a melt blow die, a flash spinning die, a centrifugal spinning die or the like for producing a nonwoven fabric. In short, what is necessary is just "a bundle having an extremely large number of filaments".

As the multiaxial nonwoven fabric in the present invention, conjugate fibers or mixed fibers made of polymers having different softening points and melting points can be used. These low softening point fibers may be contained in the tow, but as another form, other webs containing these fibers can be laminated with a multiaxial nonwoven fabric and joined with a needle punch or the like. . In the present invention, fiber means a fiber in a broad sense, not only short fiber,
Continuous or semi-continuous filaments are also included. The softening point is the temperature at which the fiber softens. Above that temperature, the fibers start to stick together. The conjugate fiber is effective in giving a high bulk and a good texture, and a low melting point component acts as an adhesive component, and can be used for bonding between filaments or between layers by hot embossing or thermocompression bonding. In addition, since the softening point and the melting point are different, mixed fibers mixed with filaments having different shrinkage ratios are also effective for giving rise to bulkiness and texture, and low softening point component fibers are used as adhesive components. It can be used for bonding between filaments or between layers by hot embossing or thermocompression bonding.

[0014] In addition, tow is usually conjugated so that the filaments do not fall apart due to static electricity or the like.
It has been crimped. However, in the present invention, the crimping is effective not only for conjugation but also for efficient operation of a needle punch method or a water jet method when bonding between filaments or between laminated materials. is there. For the crimping, usually, a press-in crimp using a stuffing box is employed, but a conjugate crimp, an edge crimp, a gear crimp, a three-dimensional crimp, and the like are also effective.

The tow used in the present invention is
A relatively small value of x is used, however, which results in poor productivity with ordinary spinning tows. However, by adopting a tow manufacturing method in which the spinning step, the drawing step, and the crimping step are performed consistently, a tow having a relatively small total tex has better productivity. That is, by adopting the integrated production method, there is no need to install a large number of boxes for storing the spun undrawn tow or a large number of boxes for supplying the undrawn tow to the drawing process, The production method of raw material tow for tow laminated nonwoven fabric was efficient in terms of factory space. In order to realize this process, it is necessary to draw a filament group traveling at a spinning speed of several thousand m / min at that speed and generate crimp at that speed. Machine is required. When employing the stuffing box method as this crimping machine, it is necessary that the stuffing box be capable of withstanding a speed of several thousand m / min. As a device that can withstand the purpose, the prior invention of the present applicant (Japanese Patent Publication No. 2-10245, etc.) can be used. In addition,
The strength increase performed in the stretching step may be performed in the spinning step, and the stretching step may be omitted.

In the present invention, not all of the filaments or fibers constituting the present invention need be tow.
If tow is used for at least a part of the filament, the purpose can be sufficiently achieved in some applications. For example, other nonwoven fabrics may be used for the warp material, and only the oblique material may use tow, or only the warp material may use tow, and the oblique material may use ordinary yarn.
Further, the tow multiaxial laminate of the present invention and another web such as a spunbonded nonwoven fabric can be laminated and joined by means such as needle punching to be integrated. At that time, it is effective to insert other webs between the vertical material and the oblique material. As this other web, when inserting a spunbonded nonwoven fabric or the like for the purpose of an extender to reduce the cost or increase the thickness, or put a meltblown nonwoven fabric for utilizing a filter effect or the like by being composed of ultra-fine filaments In some cases, there is a case where a nonwoven fabric of polyvinyl alcohol or cotton for the purpose of hydrophilicity is put, in a case where it is combined with a web having functions such as an antibacterial action or an anti-mite action, or in a case where a woven fabric is put for dimensional stability .

The most suitable means for joining filaments and between layers in the present invention is a needle punch. The needle punch can be joined efficiently even in the case of a thick material as in the present invention. In addition, as compared with the adhesive method, there are advantages that the cost is low, the material is not hard, and the water permeability required for the geotextile is not hindered. Needle punching is also an effective joining method for forming a nonwoven fabric having a large elongation, which is one of the features of the present invention. Furthermore, the molded product formed by the needle punch has a characteristic of having a soft touch and a gentle visual sense, which is an important characteristic when the molded product of the present invention is used for an automobile seat, a ceiling material, an office chair, and the like. In order to further utilize these characteristics, it is also useful to use a decorative needle in which the needle is not merely locked, in the needle punching step.

As the joining means of the present invention, besides needle punching, stitch bonding, ultrasonic joining, water jet, through air, etc. can be used. This is because these means can be joined without using an adhesive and are suitable for a thick web. When conjugate fibers or mixed fibers made of polymers having different melting points are used, they can be joined by joining means such as embossing, hot pressing, and through air. In addition, by using an adhesive web as the other web described above, it is possible to use the above-described means such as embossing and hot pressing.

These joining means are desirably performed after the tow multiaxial laminating step in a state where the both ear ends of the diagonally oblique members of the multiaxial lamination are held by pins. This is because by joining while being held by the pins, the joining is performed without disturbing the multiaxial arrangement, and the joining can be performed without disturbing the desired strength balance. In addition, the product width is constant, the disturbance in the basis weight is small, and therefore, there is no weak portion. Further, after the multiaxial laminating step and the joining step, it is preferable that the heat treatment is performed in a state in which the both ear ends of the oblique members of the multiaxial laminating which are oblique to each other are held by the pins. Distortion caused by needle punch etc.
Removal by heat treatment can contribute to product stability. If the product is produced with distortion, the product may warp or bend. By subjecting the oblique material to heat treatment in a state of being hung on a pin, a nonwoven fabric having increased constant width, flatness, dimensional stability, and the like can be obtained.

Conventionally, when performing needle punching or the like on a short-fiber non-woven fabric, a woven fabric called a carpet backing is often used as a backing material in order to obtain the above-mentioned dimensional stability, constant width, and a reinforcing effect. . However, the present invention is also characterized in that it has sufficient strength and can achieve dimensional stability, constant width, and the like without using such a backing material.

As the tow used in the present invention, a tow composed of organic synthetic fibers such as polypropylene, polyester, polyamide, acrylonitrile, and polyvinyl alcohol is used. Alternatively, tow of high-performance and high-performance fibers such as ultra-high-strength polyethylene, aramid, and polyarylate can be used.

The present invention is characterized in that the raw material tow in the present invention can be spun from waste plastic as a main raw material resin. Applications such as the geotextile of the present invention, the thickness unevenness and dyeing properties of the constituting filaments do not matter, the filament diameter is not required to be fine, and since the texture is not required, the spinning process is not required. Waste plastic containing various miscellaneous raw materials can be used as the raw material under the condition that the yarn breakage is small. Further, since it is waste plastic, its cost is low, and it is most suitable for geotextiles and the like where cost is an important factor, and has the effect of effective use of waste plastic.

[0023]

Embodiments of the present invention will be described with reference to the drawings. FIGS. 1, 2 and 3 show a model of a laminated form of the multiaxial laminated nonwoven fabric of the tow of the present invention. FIG. 1 shows an example of triaxial lamination. Many tows 1 in the vertical direction indicated by the dotted line
a is a vertical tow located on the back surface of a triaxial nonwoven fabric which is an example of the multiaxial nonwoven fabric of the present invention. A large number of tows 1b in the vertical direction indicated by one-dot broken lines are vertical tows located on the surface of the nonwoven fabric. Reference numeral 2a denotes one tow group which is a group of oblique materials oblique to each other, and 2b denotes another tow group of oblique materials oblique to the 2a group. These 1a, 1
All of b, 2a, and 2b do not need to be tows, and it is sufficient that at least one part thereof is tow. In the figure, for the sake of clarity, the flow of a single tow is indicated by a line, but the tow has a width, not a thread. Therefore, in the figure, the tow laminated nonwoven fabric is a nonwoven fabric filled with filaments on one side, although the lines are drawn in a cross-shaped net.

FIG. 2 shows an example of four-axis lamination. FIG.
The form laminated on the shaft is shown. FIG. 2B shows a traveling pattern of the toe of the first group 3a. This FIG. 2B
Therefore, one line is shown in bold to make the traveling pattern easier to understand. The four-axis laminated body is composed of a toe group 3b running obliquely and obliquely with the 3a and the toe 1a in the vertical arrangement shown in FIG.
1b.

FIG. 3 shows an example of five-axis lamination. FIG. 3A
Of the five axes, the material of the axis in the vertical direction is omitted.
FIG. 3B shows a traveling pattern of the toe of the first group 4a, in which the angles α and β when turning at the pin portion are different. The five-axis laminated body is composed of a tow group 4b that runs symmetrically and obliquely intersects with the 4a and the tow 1 in the vertical arrangement shown in FIG.
a and 1b. Not all of these materials need be tow. By providing a yarn feeding guide described later in multiple stages, it is possible to manufacture six or more axes. FIG.
Is an example of an experimental value of the strength of the multiaxial nonwoven fabric of the present invention.
The strength at elongation is shown as a strength distribution in the plane as compared to short fibers. The details will be described in Examples.

FIGS. 5 and 6 show examples of an apparatus for stacking tows according to the present invention. FIG. 5 is a plan view and FIG. 6 is a side view. 5 and 6, a conveyor 12 having pin arrangements 11a and 11b for applying tows at a constant pitch is circulating at left and right ends in the traveling direction. Above the conveyor 12, a pair of cylindrical cams 13a, 13b arranged in parallel and traversing the conveyor at a right angle is provided, and is connected by a bearing (not shown) to a rail 14 connecting the two cams as the cams rotate. The yarn feeding guide 15 reciprocates in a direction crossing the pins 11a and 11b on the conveyor 12. Another rail 16 is held by the yarn feeding guide 15 by a bearing (not shown) at a certain angle with respect to the vertical direction at different heights on the conveyor and the rail (guide rail) 14. The oblique angle of the toe in the product can be changed by the angle of the rail 16, and the angle of the tow in the product is 63.
In the case of 5 degrees, the four-axis lamination of FIG. 2 can be realized. When this angle is 90 degrees, that is, when it is parallel to the cylindrical cam, the triaxial lamination of FIG. 1 can be realized. In the case of the four-axis stacking of FIG. 2, another set of similar yarn feed guides 20 is required, and in this case, the track 21 is set at an object angle of −63.5 degrees with respect to the track 16. The yarn supply guides 15 and 20 have a large number of guide thin tubes 17 and 22 provided at a constant pitch. The rotation of the cylindrical cams 13 and 18 and the nip roll 24 is controlled by being connected to the conveyor 12 driven by the motor 23.

A large number of tows stored in a large number of boxes (cans) are fed, adjusted in tension, and supplied to the multi-axis laminating apparatus as tows 25 and 26. The tow is distributed to the yarn feeder tubes 17 and 22, respectively. Each tow supplied by the yarn feeder tubes 17 and 22 of the yarn feeder guides 15 and 20 reciprocating across the conveyor is connected to the left and right pins 1 of the conveyor.
While being held by 1a, 11b, the tow is obliquely stacked on the conveyor. Many tows 28 from canes 27a, 27b,
29 is supplied as a warp material, one tow group 28 is arranged on a conveyor, and another tow group 29 is supplied on an obliquely laminated tow group.
At 8 and 29, the oblique tow group is sandwiched from above and below. The laminated tow group is needled by the needle punching device 30 and heat-treated by the hot air heat treatment device 31 in a state where the oblique tow group is held by the pin rows 11a and 11b, thereby forming the tow multiaxial laminated nonwoven fabric 32. You. In addition, other nonwoven fabrics such as a short fiber nonwoven fabric and a spunbonded nonwoven fabric were laminated between and on the surface of the tow group, and could be integrated with the tow multiaxial laminate by needle punching or the like. In this case, if these other non-woven fabrics contain fibers having a low softening point due to conjugate fibers or mixed fibers, after forming a three-dimensional molded body, the molded body adheres with the low softening point component and maintains a three-dimensional shape. It is suitable to do.

FIG. 7 shows an example in the case of manufacturing a three-dimensional molded product. There are multiaxial nonwoven fabrics 42a and 42b of the present invention cut into a certain size on a conveyor 41, and run while being heated by infrared heaters 43a and 43b. The non-woven fabric 42c thus heated is placed on the mold 45a of the press 44, and press-molded between the molds 45a and 45b to produce a three-dimensional molded product 42d. In this case, it is desirable that the multiaxial nonwoven fabric 42 contains fibers having a low softening point. If heaters are installed in the dies 45a and 45b of the press 44 and the dies can be heated, the heating by the heater 43 can be omitted. In some cases, molding can be performed by pressing without heating.

[0029]

EXAMPLES Hereinafter, specific examples of the present invention will be described together with comparative examples. (Embodiment 1) The device shown in FIGS.
And the angle of the track 16 to the vertical direction is 9
0, and the second yarn feeding guide 20 is not used. Using a PET bottle recycled pellet as a raw material, a tex of a spun, drawn and crimped single yarn is 0.66 (6 denier), and a total tex is 5,500 (50,000 denier) tow. Obliquely laminated layers, and the vertical tow is 40 m each
The triaxially laminated tow non-woven fabric (0.95 kg / m ² , 3.2 mm in thickness) was obtained by feeding at an m pitch, sandwiching the oblique laminated tow from above and below, then needle punching, and heat-treating at 185 ° C. The physical properties of this product are These measurements are performed as follows. At each angle, cut out a sample 30 cm long and 10 cm wide.
Then, a tensile test is performed at a sample width of 10 cm, a test length of 10 cm, and a tensile speed of 100% / min to determine the strength of the sample. This strength is divided by tex converted from the mass of the sample to obtain the strength of the sample. The sample size for the test is
5 points for one direction. Of the above test results, 5
The strength at 0% elongation is shown by white circles in FIG.

(Embodiment 2) In the apparatus shown in FIGS. 5 and 6, the pin interval is 40 mm, the angle of the track 16 with the vertical direction is 63.5, and the angle formed by the second track 21 is -63.5 degrees. The second yarn feed guide 20 was also used. Spinning, drawing and crimping single yarn tex using recycled PET bottle pellets as raw material
Is 0.66 (6 denier), tex of total is 550
Using a tow of 0 (50,000 denier) as a raw material, the tow is obliquely laminated and the tow is supplied at a pitch of 40 mm each in the upper and lower directions.
Oblique lamination was performed from above and below, and needle punching was performed at about the same level as in Example 1, and heat treatment was performed at 150 ° C. to obtain a 4-axis laminated tow nonwoven fabric (1.05 kg / m ² , about 3.5 mm in thickness). The physical properties of this product are These measuring methods are the same as in Example 1. Of the above test results, the strength at 50% elongation is indicated by black circles in FIG.

(Comparative Example) The tow used in Example 1 was cut to produce a short fiber having a length of 65 mm, which was then processed by a carding machine into a short fiber web. The short fiber web is formed into a laminated web by a cross-laying method.
The layered product was subjected to the same degree of needle punching as in Examples 1 and 2 to obtain a short fiber nonwoven fabric. The physical properties of this product are These measuring methods are the same as in Example 1. The above test results are shown by the mark x in FIG. As can be seen from Examples 1 and 2 and Comparative Example, the multiaxial tow nonwoven fabric has a minimum strength of 29 mN / tex in all directions, an elongation of 70% or more, and a strength at 50% elongation of 18 mN. / Te
x, the cutting energy is 3000% · mN / tex. On the other hand, in the comparative example, the strength was 17 mN / te.
x, the elongation is 91%, and the strength at 50% elongation is 4 mN /
tex and cutting energy are about 1700% · mN / tex. Therefore, both the strength and the cutting energy could be greatly improved, and particularly the strength at 50% elongation could be greatly improved. Even in actual geotextiles and deep drawing in three-dimensional molding, elongation of 100% or more is rarely required, and in most cases, 50% elongation is sufficient, and strength at 50% elongation is strong. This is one of the features of the present invention. In FIG. 4,
In the case of three axes, the intensity in the 45-degree direction is low in the four-axis direction, but the intensity in the 30-degree direction is low in the four-axis direction. However, in actual product use, the sample width is not as narrow as 10 cm, and is therefore larger than the data value. .

Example 3 In FIG. 5 of Example 1, 100 g / m ² of short-fiber nonwoven fabric is inserted into the oblique layer side (inside of the laminate) of the length members 28 and 29. Then, all of the warp material, the oblique material, and the inserted short-fiber nonwoven fabric are needle-punched to form a multiaxial nonwoven fabric A between filaments and between layers. In this case, the short-fiber nonwoven fabric is a short-fiber nonwoven fabric obtained by subjecting a polyester composite fiber (Melty 1680, cut length 55 mm, softening point of the low softening component of the composite fiber to 110 ° C.) manufactured by Unitika Ltd. through a carding machine. This multiaxial nonwoven fabric A
Is cut to the size of the mold 45a in FIG. 7, and is put between the molds 45a and 45b and pressed. In this case, the mold 45a,
45b is heated to 150 ° C. A heat treatment was performed by the press action and the heat of the heated mold, and the molded article was taken out of the mold and cooled to obtain a three-dimensional molded body.

[0033]

According to the present invention, the nonwoven fabric is a multiaxial nonwoven fabric which is strong in multiple directions, has a uniform basis weight, and has a large breaking elongation in all directions because of high breaking elongation. It became a non-woven fabric, and a non-woven fabric having a large basis weight could be manufactured efficiently and inexpensively. This means that the multiaxial laminated nonwoven fabric of the present invention is much more effective than the short-fiber nonwoven fabric and spunbond nonwoven fabric used for the conventional thick nonwoven fabric.
Strength and cutting energy at 0% elongation could be increased. In addition, the nonwoven fabric of the present invention is much cheaper than a four-axis woven fabric that is strong in multiple directions, and can be made thicker, so that the absolute strength is large,
Large elongation. By utilizing these characteristics, it was possible to use as a tow laminated nonwoven fabric used as a geotextile, a ruing base fabric, a carpet, a vehicle interior material, a flexible container base fabric, a civil engineering sheet base fabric, and a waterproof sheet base fabric. In addition, since the individual filaments constituting the multiaxial nonwoven fabric of the tow of the present invention have crimps, the nonwoven fabric can have a high elongation, be soft, and easily deformed by soft touch. Taking advantage of the property of high elongation, three-dimensional molding such as deep drawing can be realized, and covers for automobile seats, ceiling materials, office chairs, and the like can be integrally molded. Furthermore, by coating or impregnating the tow multiaxial nonwoven fabric of the present invention with a resin, or laminating the sheet, it could be used as a waterproof sheet and a civil engineering sheet.

The nonwoven fabric of the present invention is particularly suitable for geotextiles. Geotextiles are required to have high strength and high absolute values of breaking energy, and are required to be strong in all directions. In addition, since it is buried in the soil, the cost must be as low as possible. Therefore, it is necessary to use the minimum fiber usage as efficiently as possible. The ground that is the subject of geotextiles is extremely variable, such as deformation of the terrain, obstacles such as rocks and rocks, and the mixture of soft ground and hard ground. Is required. Also,
The direction in which strength is required cannot be predicted, and in general, strength and breaking energy are required in all directions. In the present invention, since the tow made of long fiber is directly used, it has high strength and has crimp, so that the elongation up to cutting is large and the cutting energy is also large. Further, since the present invention is a multiaxial nonwoven fabric, it is strong in all directions and is most suitable for geotextal. In addition, since the multiaxial nonwoven fabric of the present invention has very few irregular portions such as uneven basis weight and weak portions, the objective can be achieved with the calculated minimum fiber usage, and the cost is also reduced from that aspect. Become cheap. The multiaxial nonwoven fabric of the present invention can be used as a geotextile for reinforcement, drainage, filtration, and the like. For example, soft ground reforming, bag dewatering method,
Sandwich method, improvement of soft subgrade support, slope reinforcement,
It can be used for railway embankment, stabilization of railway cobblestone, reinforcement of road pavement, separation of roadbed and subgrade, etc. In addition, since the tow has thin filaments continuously arranged, the capillary phenomenon works effectively, and it is effective in removing moisture in sucking, separating, filtering and the like in the modification of soft ground.

The multiaxial nonwoven fabric of the present invention has the above-mentioned advantages in terms of performance and production. Therefore, not only geotextiles but also roofing base fabrics, carpets, vehicle interior materials, flexible container base fabrics, civil engineering sheet base fabrics, waterproofing It is also used as a protective cover for sheet base fabric, machinery and furniture. In the roofing base fabric, since the absolute value of strength × elongation is large, stretch roofing (JISA6022, J
ISA6013) is particularly effective. In recent years, flexible containers have been required to be larger and safer in order to streamline distribution, and the high breaking energy of the present invention greatly contributes to this purpose. Carpets are required to be differentiated and highly functional, and the flexible and high-strength nonwoven fabric of the present invention is a high-quality and differentiated product. In addition, by combining the multiaxial nonwoven fabric of the present invention with other materials, it can be a base for various applied processed products.

Another feature of the multiaxial nonwoven fabric of the tow of the present invention is that the cut elongation can be increased. This is due to the crimp on the tow. How much crimp of the tow remains in the multiaxial nonwoven fabric depends on the tension applied to the tow during lamination and the degree of subsequent needle punching and heat treatment. A high breaking elongation means a high breaking energy (breaking strength x breaking elongation), which was described above as being particularly suitable for geotextiles and roofing base fabrics. It is also important in that a three-dimensional molded article can be manufactured. In addition, the presence of crimps gives not only a mechanical surface but also a soft texture and feel, and may be a great feature from the viewpoint of sensitivity.

The three-dimensional molding according to the present invention means that the nonwoven fabric according to the present invention is formed into a three-dimensional structure by a mechanical deformation action represented by deep drawing. The three-dimensional structure of the present invention
This is because the molded product is mechanically tough and has a soft feel as a nonwoven fabric. Another feature is that thick molded products can be molded at once.
In plastic sheet molding, in the case of a thick sheet, the thick sheet must be heated uniformly, which involves a loss of thermal energy and technical difficulty in uniform heating. However, in the multiaxial nonwoven fabric of the present invention, heating is not necessarily required for molding, and the deformability is not significantly changed by heating. Often there is no technical difficulty.

[Brief description of the drawings]

FIG. 1 shows a model diagram of a tow triaxial laminated nonwoven fabric of the present invention.

FIG. 2 shows a model diagram of a tow 4-axis laminated nonwoven fabric of the present invention.

FIG. 3 is a model diagram for explaining the tow five-axis laminated nonwoven fabric of the present invention.

FIG. 4 shows an example of in-plane strength distribution at 50% elongation of the tow multiaxial laminated nonwoven fabric of the present invention.

FIG. 5 shows an example (plan view) of a tow multiaxial laminated nonwoven fabric manufacturing apparatus of the present invention.

FIG. 6 shows an example (side view) of the tow multiaxial laminated nonwoven fabric manufacturing apparatus of the present invention.

FIG. 7 shows an example of a method for producing a three-dimensional molded product according to an embodiment of the present invention.

[Explanation of symbols]

1a, 1b: tow as warp material constituting the multiaxial tow laminated nonwoven fabric. 2a, 2b: tow as an oblique material constituting the triaxial tow laminated nonwoven fabric. 3a, 3b: tow as an oblique material constituting a four-axis tow laminated nonwoven fabric. 4a, 4b: tow as an oblique material constituting the 5-axis tow laminated nonwoven fabric. 11a, 11b: Threading pins. 12: Conveyor. 13a, 13b, 18a, 18b: cylindrical cams. 14, 16, 19, 21: Rails (guide rails). 15, 20: Yarn feeding guide. 17, 22: Yarn feeding thin tube. 23: Conveyor drive motor. 24: Nip roll. 25, 26: tow group used as oblique material. 27a, 27b: Boxes where tows are stored. 28, 29: tow group used as warp. 30: Needle punch device. 31: heat treatment apparatus. 32: Multiaxial tow laminated nonwoven fabric as a product. 41: Conveyor. 42a, 42b, 42c: Cut samples of the multiaxial tow nonwoven fabric. 42d: a three-dimensional molded product molded from the cut sample. 43a, 43b: infrared lamps. 44: Press machine. 45a, 45b: Press mold.

Claims (7)

[Claims] 1. A filament comprising 3 tex or less, having a crimp, and having a total tex of 1,0.
A multiaxial tow laminated nonwoven fabric having a plurality of parallel layers of tows of not less than 00 and not more than 30,000. 2. A tow multiaxial laminated nonwoven fabric wherein the nonwoven fabric of claim 1 is bonded between layers by at least one of the following means. Needle punch, stitch bond, ultrasonic bonding, water jet, through air. 3. The multiaxial tow laminated nonwoven fabric according to claim 1, wherein the nonwoven fabric has a strength of 10 mN / tex or more at 50% elongation in all of the vertical, horizontal, and 45-degree directions. 4. The multiaxial tow laminated nonwoven fabric according to claim 1, comprising a conjugate fiber or a mixed fiber of different polymers having different softening points, and bonded by hot embossing or thermocompression. 5. A three-dimensional molded product formed by three-dimensional molding from the nonwoven fabric according to claim 1. 6. A tow wherein, after the tow multiaxial laminating step, the bonding between the filaments or the heat treatment of the web is carried out with the two ears of the diagonally oblique members of the multiaxial laminate held by the pins. Multiaxial nonwoven fabric manufacturing method. 7. The multiaxially laminated nonwoven fabric according to claim 6, including a conjugate fiber or a mixed fiber made of different polymers having different softening points, and the multiaxially laminated nonwoven fabric is three-dimensionally molded by three-dimensional molding. And a method for producing a three-dimensional molded product made of a tow laminated nonwoven fabric by heat-treating at a temperature equal to or higher than the lower softening point of the different polymer constituting the three-dimensional molded product.