JPH026651A - High-strength wet nonwoven fabric and production thereof - Google Patents

Abstract

PURPOSE:To obtain an extremely soft high-strength wet nonwoven fabric having a strength comparable to that of a filament nonwoven fabric by forming sheets from short fibers having a specific single yarn diameter and fiber length, subjecting the resultant sheets to high-speed fluid treatment and three- dimensionally entangling the fibers therein so as to provide the average distance between the fiber entangled points with a specific length or below. CONSTITUTION:Short fibers having 7-25mum diameter of single yarns and 0.8X10<3> to 2.0X10<3> ratio (L/D) of the fiber length (L) to the single yarn diameter (D) are used to form sheets by a sheet forming method. The resultant sheets are then subjected to high-speed fluid treatment to mutually and three-dimensionally entangle the short fibers constituting the sheets and provide <=300mum average distance between fiber entangled points.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a high-strength wet-laid nonwoven fabric and a method for producing the same.

[Conventional technology]

In recent years, nonwoven fabrics have shown remarkable development, taking advantage of their excellent performance and high productivity to be used as an alternative to conventional knitted fabrics, or for functional uses that cannot be handled by knitted fabrics. Various types of nonwoven fabrics are known, but
Typical examples include the spanpond method disclosed in Japanese Patent Publication No. 4B-38025, etc., and the method disclosed in Japanese Patent Publication No. 42-19520.
A long-fiber dry nonwoven fabric obtained by directly spinning a fiber-forming polymer using the flash spinning method disclosed in et al., and simultaneously pulling and accumulating filaments I with air, gas, etc., JP-A-49-48921. A short fiber dry nonwoven fabric with a relatively long fiber length obtained by the melt blowing method disclosed in et al. After carding the short fibers, it is formed into a sheet by cross layering, air layering, etc., and depending on the purpose, entangling by needle punching or columnar water jet, Alternatively, short fiber dry nonwoven fabrics obtained by bonding with adhesives, heat-fused fibers, etc., and wet nonwoven fabrics obtained by papermaking methods are known.

Long-fiber dry nonwoven fabrics obtained by spunbonding, flash spinning, etc., have filaments as their constituent fibers, so the nonwoven fabrics obtained by thermocompression bonding are characterized by high tensile strength, tear strength, etc. Widely used for industrial materials that require high strength.

However, on the other hand, among the strengths, the nonwoven fabric's interlayer peel strength is at most 300 to 400 g/cm, which is not sufficient strength.

This designation is based on the fact that the constituent fibers are long fibers, and because the fibers are bonded together by simply thermocompression bonding, it is dimensional and there is almost no entanglement between single fibers. . In addition, since the sheet forming method of these nonwoven fabrics relies on traction and accumulation by air currents, gas flows, etc., the sheet cannot be uniformly formed.
There were disadvantages such as large unevenness in fiber properties, i.e., fabric weight, and because thermocompression bonding was used to join the filaments inside the shell, the filaments did not stretch and were hard, and 1. they lacked rapability.

In addition, short fiber dry non-woven fabric obtained by joining sheets formed by the cart method with knittle punch, adhesive, or heat-sealable fibers is similar to long fiber dry non-woven fabric, but due to its short fiber length, it has a higher strength. In order to compensate for this, the constituent fibers are often integrated using adhesives, etc., and in this case, the disadvantage is that the texture is hard.

Binder-free so-called spunlace type nonwoven fabric 4J obtained by entangling sheets formed by the Carr 1 method disclosed in Japanese Patent Publication No. 11.3749 etc. with a columnar water stream,
Compared to card method dry non-woven fabrics that are bonded using spunpond, adhesives, or heat-sealable fibers, it has a softer texture, but it is still formed using a dry process. It has drawbacks such as poor uniformity (one spot) and poor delamination strength.

On the other hand, wet-laid non-woven fabrics are formed into sheets by dispersing extremely short fibers in water, so they have a characteristic of incomparably better uniformity than dry-laid non-woven fabrics. however,
In order to uniformly disperse the fibers in water, the fiber length must be extremely short, typically around 3 to 7 mm.
Nonwoven fabric G obtained by this method: 1 has extremely low strength;
Applications are also limited to fields that do not require much strength.

In the papermaking method (3), wet-processed nonwoven fabrics are generally thinner and denser, as they are usually crimped using a fel 1- or Yankee dryer, resulting in a paper-like texture. Ta.

In this way, conventional nonwoven fabrics each have their own characteristics and defects depending on the characteristics of their manufacturing method, and they have excellent uniformity, high strength,
At present, there is currently no nonwoven fabric that has the characteristics of soft texture.

[Problem to be solved by the invention]

The present invention provides a novel wet-laid nonwoven fabric that takes advantage of its characteristics such as excellent uniformity while improving its weak strength and paper-like texture, and a method for producing the same. The purpose is to

[Means to solve problems]

The present inventors have diligently studied the above-mentioned problems and have arrived at the present invention. That is, the above-mentioned object of the present invention is that the diameter of the single yarn is 7 to 25 μm11, and the ratio L of the fiber length to the single yarn diameter is
Short fibers with /D of 0.8X10' to 2.0XIO' are three-dimensionally entangled with each other, and the distance between the fiber entanglement points is 300
This is achieved by using a high-strength wet-laid non-woven fabric with a tensile strength of μ11 or less.

The nonwoven fabric manufacturing method for obtaining the high-strength wet-laid nonwoven fabric according to the present invention is as follows: the diameter of the single yarn is 7 to 25 μm, the fiber length and the single yarn diameter D (7) ratio I-/I) b<0.8 X 10'
~2. It is characterized by forming a sheet of ( )×103 short fibers by a papermaking method, and then intertwining the short fibers with each other in the I dimension by high-speed fluid flow treatment.

The wet-laid nonwoven fabric of the present invention is composed of short fibers having a specific shape, and it is essential that the short fibers are intertwined at a specified entanglement density. A high-strength nonwoven fabric that was previously unavailable can be obtained.

The constituent fibers have a single yarn diameter of 7 to 25 μm, and a ratio L/D of fiber length to single yarn diameter of 0.8 x 103 to 2.0.
It is necessary that both of the two elements of X10' be satisfied.

If the single yarn fineness is less than 7 μm, even if L/I) is within the above range, the single yarn strength will be too low, resulting in poor tensile strength, tear strength, and interlayer peeling strength. This is too low to achieve the purpose of the present invention.

If the length of both yarns exceeds 25 μm, even if l-/D is within the range of the present invention, the fibers are too thick and the surface uniformity and density of the nonwoven fabric will be lost, making it impossible to achieve the purpose of the present invention. I can't do that. Therefore, from the point of view of strength and uniformity, the single yarn diameter must be 7 to 25 μm, and the preferred range is 10 to 17 μm.

Next, the L/D of the raw yarn is 0 within the above fiber diameter range.
．． 8XIO" to 2.0X103, and the preferable range is 1.OX10' to 1.5xlQ
It is 3.

1. of raw yarn. / D & J: The inventors have found that there is an important relationship with the degree of entanglement between fibers, and when L/D is less than 0.8XIO3,
and 2. If it exceeds OX 10'', the desired nonwoven fabric strength cannot be obtained, and the present invention's 0.8X103~
Practical high strength can only be obtained in the range of 2.0×]03. This surprising fact can be estimated as follows.

In other words, the ease of movement of the fibers due to the ↑-shaped water flow, etc. T, /l'
) is smaller, that is, the thicker and shorter the fibers are, the greater the entanglement between the fibers. On the other hand, the number of contact points between fibers increases as the fibers become thinner and longer, that is, the L/D becomes larger. However, if L/D is too large, the movement of the fibers during intertwining will be suppressed, and the intertwining of the horizontal lines, 71εJ, will conversely become smaller. Therefore, the optimal range of 1 is the maximum intertwining density between fibers.
．． , /D exists, and this range is 0.8X10' to 2
．． OX]03.

The requirements for constituting the high-strength wet-laid nonwoven fabric of the present invention are that it is composed of short fibers having the above-specified fiber diameter and L/D, and that such raw yarn has an average distance between fiber entanglement points of 30.
It is necessary to consist of two points that are three-dimensionally intertwined with each other in a state of 0 μm or less. Even if the wet-laid nonwoven fabric is made of specific short fibers as used in the present invention, the average distance between fiber entanglement points is 300 μmo even if the fibers are not intertwined with each other in the paper-formed state, or even if they are intertwined.
A relatively loose intertwined state exceeding the above is not included in the present invention because high strength cannot be obtained, which is the objective of the present invention.

Regarding the diameter of the single yarn constituting the present invention, the single yarn may have a circular cross section or various non-circular cross sections. In the case of a circular shape, the diameter of the single yarn is determined by directly measuring its diameter.In the case of a yarn with an irregular cross section, the diameter of the single yarn is determined by measuring its fineness (denier) by the gravimetric method, and this denier is determined as the diameter of the single yarn. It will be expressed by the average diameter obtained by the following formula when it is assumed that is circular.

(Here, R - Diameter of single yarn (μ river) d - Fineness of single yarn (denier) π - Circumference) The fiber average distance between intertwining points here is the following known in JP-A-58-191280. It is a value measured by the method described above, and is a measure of the intertwining density between fibers. The smaller the strands, the more dense the intertwining. FIG. 1 is an enlarged schematic diagram of the constituent fibers of a wet-laid nonwoven fabric when observed from the surface in a plane direction. The constituent fibers are f l+
f 2 + f)..., and trace the point where the fibers r l + f2 of any two trees intertwine to the point where the fiber f2, which is above at a, intersects under the other fiber. , the point where they intersect is a2. Similarly al.

Let it be a4+... Next, the linear horizontal distances al a2 , a2aJ , . . . between the intersecting points obtained in this way are
is measured, and the average value of these many measured values is determined, and this is taken as the average distance between fiber entanglement points.

The raw yarn constituting the wet-laid nonwoven fabric of the present invention includes polyamide fibers such as nylon 6, nylon 66, and nylon 610, polyester fibers such as polyethylene terephthalate 1, polyethylene ethylene terephthalate I, polypropylene, and polyethylene. Polyolefin fibers such as polyolefin fibers, regenerated cellulose fibers such as rayon, etc., have the fiber diameter of the present invention and 1. It is preferably used within the range of /D. In addition, the Young's modulus of the yarn (J5
0-700kg/ffll62, especially 50-500
kg/mm" range. 700 kg
A raw yarn with a high Young's modulus exceeding /mm2 also has high bending rigidity, and in order to achieve an intertwined state with an average fiber intertwining point distance of 300 degrees or less in the present invention, a large intertwining force (for example, a very high pressure) is required. Problems may arise, such as the need for columnar water flow.

Because the wet-laid nonwoven fabric of the present invention has such a structure, it not only has high strength, which was previously considered difficult to achieve with wet-laid nonwoven fabrics, but also has relatively long fibers such as spunbond or other long fiber nonwoven fabrics, or relatively long fibers obtained by a card method. A type of nonwoven fabric (
For example, it has much stronger interlayer peel strength than non-woven fabrics such as spunlace type non-woven fabrics such as Du Pout's ``Sontara ■'', and has excellent uniformity with less unevenness in area weight, which is a characteristic of wet-laid non-woven fabrics. It's also holding. Furthermore, compared to wet-laid nonwoven fabrics that are bonded with regular adhesives, the fibers are bonded together only by three-dimensional entanglement, and there is no need to use adhesives or other bonding means, resulting in an extremely soft texture and drapability. It also has the characteristic of being rich in

As described above, the nonwoven fabric of the present invention has the uniformity that is characteristic of the wet process, while also having high strength and a soft texture that overcome the disadvantages of the wet process. It also has strong delamination strength, which non-woven fabrics lack, and has performance that could not be expected from conventional non-woven fabrics, so it can be used in applications that are difficult to apply with conventional non-woven fabrics. I can do things.

One suitable example thereof is materials for medical and sanitary + A applications, such as medical materials such as surgical bags, surgical gowns, and underpads, and sanitary materials such as diapers, napkins, and masks. In these applications, the characteristics of the nonwoven fabric of the present invention, such as drapability, rich texture, and high strength, are well utilized.

In particular, when the nonwoven fabric of the present invention is used in surgical gowns, the property of excellent liquid barrier properties, which is particularly required for surgical gowns, can be effectively utilized. The nonwoven fabric of the present invention has a specified L/D
Since the short fibers are intertwined with high density, it itself has a high level of liquid barrier property. As an attempt to obtain the liquid barrier properties required for surgical gowns using conventional nonwoven fabrics, for example, as disclosed in Japanese Patent Application Laid-Open No. 59-94659, a nonwoven fabric made of polyester (polyethylene tereph clay 1-) made of fine fibrils has been proposed. It has been devised to increase the density of the nonwoven fabric by jetting a columnar water stream onto a sheet obtained by laminating or mixing wood pulps to entangle the pulp with polyester in a so-called "filling" manner, but in the present invention, teeth,
Excellent liquid repellency can be obtained simply by using a 1d12.5+++m raw yarn of polyester (polyethylene terephthalate), for example, without using special inner fibers (such as special meshing). has been confirmed.

When the nonwoven fabric of the present invention is used as an interlining material for clothing, the characteristics of uniformity and high strength are well utilized and it is suitable. It is also suitable for industrial wiping cloths such as those used in the electronic field. This is because the nonwoven fabric of the present invention has no binder and the fibers are firmly joined by interlacing the fibers, so it has excellent lint-free properties, and is flexible, so it has excellent wiping properties. Furthermore, it is also recognized to be suitable as a filter for gases and liquids, especially as a so-called pre-filter for filtering particles of 5 to 25N. This is a result of the fact that the average distance between fiber entanglement points of this nonwoven fabric is small and dense, which is fully utilized for its filter function.

When using the nonwoven fabric of the present invention as a coating base fabric,
The characteristics of the nonwoven fabric of the present invention are well utilized.

In other words, attempts have been made to use conventional nonwoven fabrics as coating base fabrics in place of conventional woven or knitted base fabrics, but these nonwoven fabrics have lower interlayer peel strength than woven or knitted fabrics, so the surface of the nonwoven fabric Coated products obtained by coating polyurethane or polyvinyl chloride on nonwoven fabrics often suffer from peeling between the layers of the nonwoven fabric during use, making them unsuitable for practical use. In order to improve this drawback, nonwoven fabrics include polyurethane, polyacrylic ester, SBR, MBR, and NBR.
Apply an elastic polymer such as as a binder in advance,
Subsequently, the surface has been coated with polyurethane, polyvinyl chloride, etc., but in this case, the texture becomes paper-like and the quality is inevitably inferior to that of woven or knitted fabrics. With respect to dirt, the nonwoven fabric of the present invention has extremely high delamination strength compared to conventional nonwoven fabrics, so it can be used as a coating base fabric without a binder, which is not seen in conventional nonwoven base fabrics. It has new features such as a soft texture and excellent peel strength between high-rise layers.

One of the preferable examples is to use the nonwoven fabric of the present invention as a base fabric for leather. For example, real nonwoven fabric is
Used as a base fabric and coated with polyurethane, vinyl chloride, SBI? By applying a solution of an elastic polymer such as NIIR, MBR, etc., or emulsion 51 using a gravure machine, a doctor knife, etc., a silver-like artificial leather can be obtained. In this case, it is more preferable in terms of strength and texture to impregnate the nonwoven fabric with an elastic polymer such as polyurethane and dry or wet coagulate and fill it, if necessary, before forming the surface coating layer.

Furthermore, if you want to obtain suede-like leather, you can laminate sheets 1~ made of ultrafine fibers with a single fiber fineness of 0.5 d or less on this nonwoven fabric, and integrate this laminate by three-dimensional entanglement. It is also possible to obtain the desired suede-like artificial leather by forming a composite nonwoven fabric, raising the ultrafine interlaced layer, impregnating it with an elastic polymer, etc. as necessary, or dyeing it.

Next, a method for producing a high-strength wet-laid nonwoven fabric of the present invention will be explained.

First, single yarn diameter 7~25 um, L/D 0.8
Short fibers having a specific shape of XHI' to 2X10'' are prepared.

A slurry is prepared by dispersing this in water to a concentration of 0.1 to 3%. At this time, it is preferable to add a small amount of a dispersant. This slurry is made into paper using a fourdrinier type or circular net type paper making machine. The basis weight is 5 to 500g/depending on the application.
It is preferable to set it within the range of r + It is good and also has two different materials and/or shapes.
It is also preferable to use one type or a mixture of three types of yarn. The obtained paper sheet is entangled with a high-speed fluid stream. The fluid here refers to a body or a gas, but water is most preferable from the viewpoint of ease of handling, cost, and high collision energy as a fluid. When water is used, the water pressure varies depending on the type of yarn used and the distance of the papermaking sheet I, but in order to obtain an average distance between fiber entanglement points of 300 μm, the water pressure is 5 to 200 kg/cIN, preferably 10
~80kg/(Collide within the range of the barge.

In the case of the same raw yarn, the water pressure for one culm of a low eye spring is low, and the higher the basis weight, the higher the water pressure may be set. In addition, in the case of the same objective, in the case of yarn having a high Young's modulus, high strength, which is the object of the present invention, can be obtained by treating with a water stream of higher pressure. The diameter of the nozzle that sprays the water stream is preferably 0.01 to 1 mm. The shape of the trajectory of the water stream may be a straight line parallel to the direction of advance of the papermaking sheet, or it may be a curved shape obtained by the rotational movement of a header equipped with a nozzle or the vibration motion that reciprocates at right angles to the direction of progress of sorting. It's okay. The intertwining of multiple circular water flow trajectories obtained by rotational motion is
The spray area of the water stream against the sheet per nozzle is large, which is efficient, but at the same time, depending on the application, it is difficult to see spots in the trajectory of the water stream, which can reduce the product value. Advantages and preferred. The paper sheet may be treated with a high-speed water stream by spraying the water stream alternately on the front and back sides, or it may be applied on one side. Moreover, the optimum conditions for the number of processing times may be selected depending on the purpose.

The water pressure conditions for the columnar water flow treatment of these paper sheets are selected under such conditions as to obtain the desired average fiber entanglement point distance of 30,071,111 or less and to obtain uniformity, for example, 10 to 100 g/rd. relatively small eyes (=
In the case of J papermaking sheet processing, 10 to 40 kg/
It is preferable to treat one or both sides with water pressure.
In the case of a relatively large basis weight of 50 to 500 g/rrf, it is preferable to spray columnar water streams alternately on both sides at a water pressure of 30 to 80 kg/c+fl. To further describe the columnar water flow conditions for obtaining an entangled state with an average distance between fiber entangled points of 300 μm or less, for example, polyethylene terephthalate
1. For a sheet made of 1 denier (PET) short fibers with a length of 10 mm and a weight of 100 g/n,
10 to 2 rows of nozzles with an orifice diameter of 0.07 to 0.25 mm are drilled or arranged at a nozzle spacing of 1 to 8 mm.
Using a nozzle header equipped with a large number of nozzles arranged in 0 rows, the treatment is performed once on each side alternately at a water pressure of 30 to 50 kg/c. At this time, the rudder to the nozzle is 50~500r.
, p, m (corresponding to a sea L processing speed of 2 to 20 TnZ). Furthermore, if necessary, if the water flow trajectory remaining on the sheet surface impairs the quality of the product, a wire mesh of 40 to 100 meshes is inserted between the nozzle header of the same structure and the sheet to sprinkle the columnar water flow and reduce the water flow trajectory. It is also a preferred embodiment to reduce the depth.

As an embodiment included in the manufacturing method for producing the high-strength wet-laid nonwoven fabric of the present invention, after the paper-formed sheet is entangled with a columnar water stream, the sheet is placed on, for example, a rough wire mesh (10 to 20 meshes). It is also preferable to spray a columnar stream of water from the wire mesh to create a pattern with holes that follow the pattern of the wire mesh. The nonwoven fabric of the present invention obtained in this case is found to have improved bulkiness, dimensional stability (elongation recovery rate), etc., compared to the nonwoven fabric before patterning with openings.

Furthermore, as a mode of post-processing of the high-strength wet-laid nonwoven fabric 1 obtained by the present invention, it is also preferable to cold or hot press it with an engraved roll (emboss roll) to shape the surface. According to this method, each time the intertwined sheets are joined, it has been observed that the strength such as tensile strength is improved, and it also has the unexpected effect of improving dimensional stability. I understand.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In the Examples, the measured values were determined by the following method, and all percentages are by weight.

1) Tensile strength: JISLI096 slip-lip method 2) Tear strength: JISLI096 single tongue method 3) Interlaminar peel strength: The nonwoven fabric is cut into four pieces with a diameter of 2.5 cm and a length of 13 cm.

Adhesive tape (D3 manufactured by Sony Chemical ■) was applied to the sample.
After adhering 200"C, 70g/c+R(D pressure-('200"C), press for 30 seconds and bond together.

A slit is made between the adhesive tape and the nonwoven fabric of the measurement sample thus obtained, and both ends are gripped with an autograph chuck and measured. The measurement conditions for the autograph are set as follows.

Tensile speed: lOcrn / Minature 1 Speed: 10cm/min Since the tape is strong and the tape and non-woven fabric are firmly bonded, when the tape of the measurement sample is peeled off from the measurement sample, The peeling force acts to peel one part of the nonwoven fabric from another part without cutting the tape or peeling off the adhesive surface between the tape and the nonwoven fabric. Therefore, the delamination strength of nonwoven fabrics can be measured by this method.

From the stress-strain curve obtained when performing the above measurement using an autograph, three of the larger intensity values and three of the smaller intensity values are selected, and the average value of the six values in total is obtained. The number of test samples for measurement is 5.

This kind of measurement is carried out in the vertical direction (MD) and horizontal direction (MD) of the nonwoven fabric.
CD), and the average value of the vertical/z-horizontal values is taken as the interlayer peel strength of the nonwoven fabric.

4) Flexibility: JISL1096 45° Kanjireher method The average value of the longitudinal direction (MD) and the longitudinal direction (CD) is taken and used as the flexibility.

5) Average distance between fiber entanglement points: 100 by scanning electron microscope
Measurements were made at twice the magnification, and the average value of 50 measurements was taken.

Polyethylene terephthalate fibers having an area of 1 d (10 I1 m) were cut into 10 mm (L/D-103) and dispersed in water to form a slurry with a concentration of 1%. This slurry was made into paper using an inclined fourdrinier machine to obtain a sheet with a basis weight of 50 g/n.

On this sheet, a large number of nozzles with a nozzle diameter of 0.1 mm, a pitch between nozzles of 5 mm, and 18 rows were used to generate 30 kg/c.
A columnar water stream with a water pressure of Ill was jetted D=I to entangle the fibers. The distance between the nozzle and the sheet-forming sheet 1- was 30 mm, and an 80-mesh wire mesh made of stainless steel was used as a supporting member under the sheet-forming sheet. Similar treatment was applied to the opposite side of the sheet.

Then, the water pressure was set at 8 kg/cf, and both sides were similarly sprayed with a columnar water stream. After that, it was dried to obtain an entangled sheet. The average distance between fiber entanglement points of this nonwoven fabric is 70μ
It was m. The physical properties showed the following values.

Tensile strength (vertical/horizontal): 2.0/1.9
kg/c+n tear strength (cut/yo:]): 1.
6/1.4kg Peeling strength: 2100
g/cm Flexibility (vertical and horizontal average): 2B+mn As a comparison, a long-fiber polyethylene terephthalate nonwoven fabric obtained by the spunbond method (Asahi Kasei Spunbond E 3050° (made by Asahi Kasei T Co., Ltd.) 50
The physical properties of g/rrr) were as follows.

Tensile strength: 2.4/1. Okg/cm Tear strength: 1.1/1.2kg Peeling strength: 230 g/c, m Flexibility
: 41 mm As described above, although the nonwoven fabric of the present invention is a wet-laid nonwoven fabric, it has tensile strength and tear strength higher than that of a long fiber nonwoven fabric, and has a much higher delamination strength.

Furthermore, it has an extremely flexible texture and a uniformity comparable to that of conventional wet-laid nonwoven fabrics (
It was found that the fabric has excellent quality compared to any conventional nonwoven fabric.

1tff7↓ 0 of polyethylene terephthalate (hereinafter abbreviated as PET)
．． A 1d (3 μm) raw yarn was produced by a direct spinning method and cut to a length of 3 mm (L/D=10′). Example 1
The average distance between fiber entanglement points of the resulting nonwoven fabric, which was paper-formed and subjected to columnar flow treatment in the same manner as described above, was 36 μm. The physical properties were as shown below.Tear strength was particularly low.

Tensile strength: 1.4 / 1.2 kg/cm Tear strength: 0.210.2 kg Interlaminar peel strength: 910 g/cm Flexibility: 24 mm R'ET1 denier (10 μm) as Konoka J stripping yarn, length 51
mm (L/D=5.1 This paper sheet was subjected to the same columnar flow treatment as in Example 1. However, the pressure was 4.
Fl kg/cM, the second time was 25 kg/cJ. The average distance between fiber entanglement points was 330 μm, and the physical properties were as follows.

Tensile strength: 0.8 / 0.7 kg/cm Tear strength: 3.6 / 3.4 kg Peeling strength: 210 g/cm Flexibility: 39 m + 1 Nylon 6 as yarn 5 denier (24pm) 5m
A paper sheet was obtained in the same manner as in Example 1 using m (L/D = 0.21 x 103). The dispersion state of the fibers in the slurry was good. Target weight is 50g/rW
Met. This paper sheet was subjected to an entanglement treatment using a columnar flow using the same equipment and conditions as in Example 1. The average distance between fiber entanglements was 340 pm. Moreover, the physical properties were as follows.

Tensile strength: 0.4/0.2 kg/cm
Tear strength: 0.8 / 0.6 kg Peeling strength: t9sg/cm Flexibility: 43mm Young's modulus: 900kg/c+fl polypropylene fiber, 3 denier (221 Im), length 20
Using short fibers of mm (L/D = 0.91 x 103), papermaking and columnar flow entanglement were performed in the same manner as in Example 1 to obtain an entangled nonwoven fabric with a grain size (t 50 g/po). Average fiber entanglement The point distance was 350 μm, and the physical properties were as follows.

Tensile strength: 0.1 / 0.09 kg/cm Tear strength: 0.710.3 kg Peeling strength: 180 g/cm Flexibility: 41 mm Nylon 66 as yarn], 5 d (13,1 μ
m), length 12.5mm (L/D = 0.95
300 mm in the same manner as in Example 1 using a raw yarn of
A paper-making sheet 1- of g/ra was made. The columnar flow equipment has a nozzle diameter of 0.2 mm, a pinch between nozzles of 5 mm, a number of nozzle rows of 12, and a distance of 30 mm between the nozzle and the papermaking seam 1.
A wire mesh of 80 mesosib was used as a support for the paper-made sheet. The first time was 70k because the water was dehydrated through a wire mesh.
g/cff 12th time, columnar water streams were injected onto both sides of the papermaking sheet 1-1 at a water pressure of 50 kg/ctM. After drying, the average distance between fiber entanglement points of the interlaced nonwoven fabric was measured and found to be 90 μm.

The physical properties are as follows: this nonwoven fabric was uniform and had good vertical/horizontal strength isotropy, and was suitable for civil engineering materials such as roofing.

Tensile strength: 16.1/15.7kg/r
am tearing strength: 9.7 /10.6kg Delamination strength: L900g/Cm Flexibility Near 4mm F1 row a- 1 denier (9.7μm) of viscose process cellulose fiber (rayon), I 5n++n (L/ D-1,5
Using a yarn of 5×103), the same procedure as in Example 1 was performed to obtain a yarn of 40 g/r+? I got a sheet of The conditions for the columnar flow entanglement process were as follows. Orifice diameter 0.08 mm, nozzle pitch 2 mm, number of nozzle rows IO rows, distance between nozzle and papermaking seam 1 50 strokes, support member wire mesh 60 mesh 1. .

Water pressure 15 kg/c+fl for the first time, 23 k for the second time
g/c+ll, 3 times 116kg/C111, number of passes: 3 times each on the front and back sides. The interlaced nonwoven fabric obtained after drying had a distance between fiber entanglement points of 52 μIn, which was -2. The physical properties are as follows, and it has almost the same strength as the cellulose long fiber nonwoven fabric (“Henryse ■” manufactured by Asahi Kasei Gyogyo ■ 40g/+d) that was measured at the same time as a comparison, but has a softer texture and drapeability. It was a nonwoven fabric with excellent properties.

Tensile strength: 0.14/0. l0kg/cm
Tear strength: 0.30/0.25kg Peeling strength: 1,020 g/cm Flexibility: 26
mm Physical properties of “Benliese ■” Tensile strength: 0.22/0.03kg/cr
n Tear strength: 0.21/0.24kg Peeling strength: 160g/cm Flexibility: 34mm Real Jili [4 PET 2.0 denier (14μm), 20mm (
1-/D = ], /12 x 10”) of 20
A paper sheet of g/r+f was obtained in the same manner as in Example 1. Furthermore, 30 g of wood pulp/
The paper-making sheet 1~ of RL was obtained.

Pulp paper sheets 1~ were sandwiched between two PET sheets of 20 g/r+r to form a three-layer laminated sheet 1~. This laminated sheet was subjected to columnar treatment under the following conditions. Nozzle diameter: 0.1 +nm, nozzle pitch: 5mm, number of nozzle rows: 15 rows, distance between nozzle and sheet: 30mm, water pressure: 15 kg/afl for the first time,
2nd time 28kg/c++1. Rotation speed of the rudder to the nozzle = 70° rpm, sheet speed = 6 m/min, threading method =
Both sides were treated twice. The average distance between the intertwined fiber points of the obtained intertwined sheet was 32 μIll. The physical properties are as follows, and by taking advantage of the hygroscopic function of the pulp, it was suitable for disposable clothing, such as surgical gowns.

Tensile strength: 4.1 / 4.0 kg/cm Tear strength: 3.1 / 2.9 kg Peeling strength:
1,300 g/cm Flexibility: 42 mm, 1.5 denier (15,
6μm), 17.5mm (1−/D=1.
1 denier (9.7 μm opening), 12.5 n+m (L /
D = 1.3
A sheet-formed sheet weighing 60 g/rd was obtained in the same manner as in Example 1. Columnar flow treatment was performed on these paper sheets 1 to 1 under the same conditions as in Example 4. The average distance between fiber entanglement points of the entangled sheet was 150 μm, and the physical properties were as follows. This nonwoven fabric takes advantage of the antistatic and hygroscopic properties of cellulose, etc.
It was suitable for electronic I-conics wiping cloths, floppy desk liners, etc.

Tensile strength: 3.6/3.3 kg/cm Tear strength: 2.4/2.1 kg Peeling strength: 1,230 g/cm Flexibility:
39mm 2 denier (1, 5, 1μm) of nylon 66 fiber, 1
Using raw yarn of 5 mm (L/D-1,0X103), 9
A paper-made sort of 5 g/l "γ" was obtained. This paper-made sheet was passed through the same columnar flow nozzle as in Example 1, twice each on the front and back sides, at a water pressure of 40
Confounded by kg/aR. The average distance 11 between fiber entanglement points of this nonwoven fabric was 93 pm. The physical properties were as follows.

Tensile strength: 6.3/5.6 kg/cm
Tear strength: 3°5 / 2.7 kg Peeling strength: 2.1 kg / (: TI + flexibility: 3
7 mm The surface of this non-woven fabric was coated with polyurethane (concentration 30%) containing polyamide resin in an amount of 45 g/rd using a doctor knife.

The resulting coated product has an extremely soft texture because it is a non-woven fabric or has no binder, and the folds on the surface of the polyurethane film are fine and have a natural and luxurious feel, similar to the silver surface of natural leather. Met. Furthermore, since the interlayer peeling strength is sufficiently strong, it was confirmed that there would be no damage such as peeling during use, even when used as a material for, for example, upholstery.

1.5 denier (13.1 μm) of special nylon 6 fiber, 1
A paper-made sheet of 300 g/rt'j was obtained using a raw yarn of 2.5 mm (L/D = 0.95X10"). This paper-made sheet was prepared using a nozzle diameter: 0.2 mm, a nozzle pitch: 5 mm, and a nozzle row. Column flow treatment was performed with number = 18 rows, distance between paper sheet and nozzle: 30 man, nozzle header rotation speed: 150 rpm, and sheet speed: 5 m/min.The average distance between fiber entanglement points of this entangled sheet was 12
The physical properties were as follows.

Tensile strength: 18.9/16.4kg/c+n Tear strength: 13.1/I1.5kg Interlayer peeling strength:
2,210 g/cn + this entangled sea 1 ~, polytetramethylene glycol as a polyol component, and P as an isocyanate component.

It was impregnated with a 15% dimethylformamide solution of P'-diphenylmethane diisocyanate and polyurethane using ethylene glycol as a chain extender, squeezed to a squeezing rate of 300%, and coagulated in water.

After drying, one side of the obtained impregnated sheet was puffed using a held sander equipped with 320 mesh emery paper. Next, the ground surface was hot pressed with a calender roll with a surface temperature of 150"C. Polybutylene adipate, P, P'-diphenylmethane cyisocyanate-1,
, coated with 30% dimethylformamide having the composition of ethylene gelcol, coagulated in water, and dried.

Further, this surface was coated with a 40% solution of a mixed solvent of polyethylene glycol, P, P' diphenylmethane diisocyanate, and ethylene diamine in methyl ethyl ketone and isopropyl alcohol using a gravure roll.
The solvent was removed by drying at 30°C. The silver-like sheet material obtained in this way has a polyurethane coating layer with extremely good surface smoothness, excellent flexibility in texture, and physical properties as shown below. It had sufficient strength to the extent that it could be obtained.

Tensile strength: 21.5/20.6kg/cm Tear strength:
13.8/12.1kg Flexibility: 81mm 1 denier (10.7 μII+) of nylon 66 fiber,
A 200g/lTf paper sheet made of 10mm (L/D=0.93X10'') short fibers is coated with 0, 1 denier, 5 mm PE, T ultrafine short fibers obtained by direct spinning. 70 g/n (paper-made sheets were laminated. This was subjected to columnar flow treatment under the same conditions as in Example 6 to obtain an entangled sheet. The average distance between fiber entangled points observed from the nylon 66 sheet surface of this nonwoven fabric is 93I1m,
The physical properties were as follows.

Tensile strength: 12.6/10.8kg/Cl
11 Tear strength: 8.9/8.7 kg Interlayer peel strength: 1,900 g/cm Puff the surface of the PET ultrafine fiber sheet side of this laminated entangled sheet with a held sander equipped with 240 mesh emery paper, and then was coated with a 20% aqueous solution of polyvinyl alcohol, which is insoluble in cold water and soluble in hot water, using a doctor knife, and dried with hot air. This sheet is impregnated with a polyurethane emulsion made by dispersing polypropylene glycol, isocyanate, and coachi diamine in water at a concentration of 1.5%, and the water is removed by hot air drying to solidify. I let it happen. Thereafter, polyhinyl alcohol was removed with hot water at 80°C, and PIE', T, and nylon 66 were dyed in the same bath using a circular dyeing machine, and washed and dried. The sheet autumn material obtained in this way is
The surface of the PIIT O.1 denier layer had an elegant suede effect, and the overall material exhibited sufficient strength and a soft texture, giving it a luxurious feel suitable for the clothing and interior decoration fields.

Tensile strength: 13.0/ ] 1.3 kg/cm Bow tear strength: 6.7/6.0 kg Flexibility: 63 mm [Effects of the Invention] The high-strength wet-laid nonwoven fabric of the present invention is constructed as described above. Therefore, it has the strength of long fiber non-woven heavy fibers and has a very soft texture. In addition, the uniformity of the nonwoven fabric is a wet-laid nonwoven fabric, which is far superior to that of a spunbond nonwoven fabric made of long fiber nonwoven fabrics.

[Brief explanation of the drawing]

FIG. 1 is an enlarged schematic diagram of the constituent fibers when observed from one surface in the planar direction of the nonwoven fabric of the present invention. f, ~f7... Constituent fibers, a1-a7... Intertwining points of constituent fibers.

Claims (2)

[Claims] 1. The diameter of the single yarn is 7 to 25 μm, and the ratio L/D of the fiber length L to the diameter D of the single yarn is 0.8 x 10^3 to 2.0 x 10^3
A high-strength wet-laid nonwoven fabric in which short fibers are three-dimensionally entangled with each other, and the average distance between fiber entanglement points is 300 μm or less. 2. Short fibers with a single yarn diameter of 7 to 25 μm and a ratio L/D of fiber length L to single yarn diameter D of 0.8 x 10^3 to 2.0 x 10^3 are formed into a sheet using a papermaking method, and are processed at high speed. A method for producing a high-strength wet-laid nonwoven fabric, characterized by three-dimensionally entangling short fibers with each other through fluid flow treatment.