JP2817057B2 - Nonwoven fabric having aperture pattern and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a nonwoven fabric having a pattern, particularly a perforated pattern, and a method for producing the same. More specifically, it consists of short fibers,
Excellent in physical properties such as strength, dimensional stability, and durability, as well as liquid absorbency, texture, and feel, wiping cloths, surgical dressings, bandages, lace-like table cloths and curtains, decorative cloths, clothes, The present invention relates to a nonwoven fabric having openings suitable for use as a wide variety of fiber cloths such as industrial material cloths and a method for producing the same.

[Conventional technology]

The nonwoven fabric having a perforated pattern or a concavo-convex pattern is useful as a cleaning cloth or a washing cloth or as a surgical patch, due to its form. That is, since the contact area with the liquid is increased by the patterning, the contact point with the object is smaller than that of the nonwoven fabric having a relatively smooth surface while exhibiting good liquid absorbability, and the number of contact points with the object is reduced. The frictional resistance is low, and at the same time, a strong force acts at the contact point to give a good wiping action. In addition, as a surgical patch, excessive contact with the wound surface is avoided, and the necessary absorption of body fluid is performed from a partial contact point, and exhibits good characteristics as a wound patch. .

Various attempts to obtain a nonwoven fabric having such a perforated pattern or an uneven pattern have been disclosed.

For example, a fiber material layer is sandwiched between a mold plate having a large number of mold holes and a microporous plate, spraying a relatively low water pressure spray water flow from the mold plate surface side to move fibers between the plates. A method of producing a nonwoven fabric having openings corresponding to the mold holes of a template, or a method of producing a nonwoven fabric having a concavo-convex pattern corresponding to the mold holes by spraying spray from the side of a microporous plate (T. Kimiaki) 36-7274, Japanese Patent Publication No. 40-8756). A fiber layer is placed on a water-permeable mold having a large number of fine protrusions, and a relatively low-pressure spray water stream collides with the fiber layer, thereby moving the fibers along the protrusions and causing the fibers to move on the protrusions of the mold. A method for producing a nonwoven fabric having a corresponding pattern (Japanese Patent Publication No. 44-23909). A method in which a high-pressure, small-diameter columnar water stream is made to impinge on a fiber web held on a support member having openings to obtain a nonwoven sheet having openings (Japanese Patent Publication No. Sho 47
-18069). Furthermore, scattered in a regular array,
Areas where the fibers are highly entangled in three dimensions, areas of another group of fibers that are in a relatively elongated fashion interconnecting these areas, and are separated by these areas Non-woven fabric having a specific impermeability evaluation value and structural characteristics, which is composed of an area where fibers are absent or exist only at a low density, and which has a specific impermeability evaluation value (Japanese Patent Publication No. 49-20823). ) Are known.

These known patterns, especially nonwoven fabrics with a perforated pattern, when used as a cleaning cloth or a dressing cloth, have excellent properties as compared to ordinary nonwoven fabrics having a relatively smooth surface. It is still not enough. In these applications, particularly high liquid absorption and sufficient strength are required. Soft texture and touch are also important required characteristics. The ability to wipe off water droplets during wiping and the rapid absorption of bodily fluids during surgical procedures depend on the liquid absorption properties of the nonwoven fabric. Further, the durability as a wiping cloth, and the removability and the safety of the dressing cloth depend on its strength characteristics, particularly the strength when wet. JP-B-36-7274, JP-B-40-8756, and JP-B-44-23909 disclose that a fiber sheet having a short fiber length (10 mm or less) is 5 to 7 kg / cm ^{2 through a} template. A method for obtaining a perforated non-woven fabric by performing a water pressure sprinkling flow treatment is disclosed. In this method, the fibers are relocated on the surface of the template member by running water to form a perforated nonwoven. The product obtained by this technology basically has only the rearranged fibers of the papermaking sheet, and there is almost no interlocking between the fibers, so it does not have sufficient practical strength, and the final Specifically, a treatment with an adhesive is performed before use. The adhesive is
Impairs the excellent liquid absorbency inherent in this nonwoven fabric,
It has a hard feel. Furthermore, the presence of an adhesive is not desirable from a hygienic and medical point of view.

JP-B-47-18069 and JP-B-49-20823 disclose that a fiber web on an apertured member has a water pressure of 7 to 352 kg / cm.
It is disclosed that by colliding the high-pressure columnar water stream of No. ² , a perforated nonwoven fabric having sufficiently practical strength can be obtained without requiring an adhesive or a binder. In these inventions, as the raw material fiber web, a fiber having a relatively long yarn length, for example, a continuous filament or a yarn length of 2.5 to 3.8
A staple fiber of cm is used.
For this reason, the number of fiber ends contained in the nonwoven fabric is relatively small, and the soft touch feeling is lacking, and the liquid absorbing property is poor. Shorter paper length fiber (0.635c
The use of m) is also indicated, but also in this case, the use is limited to mixing with a web having a relatively long fiber length. Because, in these inventions, the raw web fibers are pushed into the openings of the opening member by the collision of the high-pressure columnar water flow, but when the raw materials having a short fiber length are used, they are selectively moved to the openings. Because it is easy, the amount of fiber connecting the apertures and the apertures will be reduced,
Further, since the fiber length is short, even when the connecting portion is formed, it is not possible to sufficiently entangle the fiber in the opening portion. Therefore, when a raw material web having a short fiber length is used, as a result, the strength of the entire nonwoven fabric is not sufficiently exhibited. In these inventions,
Since the degree of concentration of the fibers in the openings is increased, the strength of the entire nonwoven fabric is more dominated by the strength of the connecting portion connecting the openings having a lower fiber density. It is of lower strength for the basis weight. In addition, since the fiber aggregate in the connecting portion has a uniform shape, when the connecting portion is composed of short fibers, the fiber itself does not have sufficient strength.

Japanese Unexamined Patent Publication No. 63-243360 discloses a nonwoven fabric having a regular opening pattern with a high surface smoothness without a density pattern by treating a fiber web in a columnar flow on a cylinder having a large number of projections on the surface. It has been disclosed. Although a nonwoven fabric with a high vertical strength was obtained because the fibers were arranged in a vertical direction, the horizontal strength was insufficient and the dimensional stability in the horizontal direction was lacking.

Also in the invention of this one, the fiber length of the raw fiber web is used in the range of 20 to 100 mm, which lacks a soft touch feeling and is inferior in liquid absorbing property, and the thickness direction between the fibers in the thickness direction is reduced. The entanglement density is low and the delamination strength is not sufficient.

[Problems to be solved by the invention]

The invention consists of stock-length fibers and therefore has a large number of fiber ends, resulting in a pattern with a good texture, hand and very good liquid absorption, especially perforated It provides non-woven fabrics with patterns and irregularities suitable for applications such as weing cloths, surgical dressings, and bandages. It is an object of the present invention to provide a nonwoven fabric having a perforated pattern having a high strength and not requiring an adhesive treatment with a resin or the like, and a method for producing the same.

[Means for solving the problem]

In the present invention, the fiber length is 15 mm or less, the single yarn fineness is 0.5 to 5 denier, and the ratio L / D of the diameter D of the single yarn to the fiber length L is 0.8 × 10 ³ to
A nonwoven fabric composed of short fibers of 2.0 × 10 ³ having openings scattered in a regular arrangement in the nonwoven fabric, and the short fibers constituting the nonwoven fabric surround the openings, forming nodules and Arranged in a regular pattern of connecting parts connecting the nodules to each other and forming an overall network, the short fibers penetrate in each area of the nodules and connecting parts and / or between the respective areas, A nonwoven fabric having an aperture pattern, characterized by being irregularly curved, twisted, wound, and interlaced with each other so that the distance between interlaced points is 300 μm or less.

The fiber length in the present invention is 15 mm or less short fiber, the material is arbitrary, for example, polyester, nylon,
Vinylon, rayon, cupra, cotton, wool and the like are used. Further, it may be based on a copolymer. Further, so-called composite fibers or mixed fibers (blend fibers) made of two or more kinds of materials are also suitable. These may be used as a mixture. The fineness of these fibers is preferably 0.5 to 5 denier. Particularly preferably, the ratio L / D of the fiber length to the single yarn diameter is from 0.8 × 10 ^{3 to} 2.0 × 10 ³ . When it is at this value, a non-woven fabric with particularly high strength is obtained. For applications such as a surgical dressing cloth, a dishwashing cloth, and a table wiping cloth, it is desirable to use a fiber composition mainly composed of water-absorbing fibers such as cellulosic fibers and acrylic fibers. It is also preferable to mix vegetable pulp fibers. When higher strength is required, use of polyester or nylon is desirable. Moreover, the composite heat-fused fiber further contributes to the improvement of the strength by the action of the thermal bonding. These are mixed according to the application, and the optimal product characteristics are designed. A short fiber having a fiber length of 15 mm or less forms a large number of fiber ends (fluff) in the nonwoven fabric, and as a result, provides excellent liquid absorbency and feel. In addition, there is a particularly great feature in that various fibers can be uniformly mixed and that an extremely uniform sheet can be formed.

The opening in the present invention is an opening penetrating from the front surface to the back surface of the nonwoven fabric of the present invention, and the shape and size thereof are arbitrary, but the maximum major axis is 5 mm or less, and the opening area per piece is 20 mm ^2.
The following is desirable. The percentage of apertures in the entire nonwoven fabric is
It is desirable that the projection area ratio be 90% or less. This opening is formed by the state of aggregation of the fibers constituting the non-woven fabric, and is formed by cutting, fusing, or shaving the portion and causing the fiber to break. is not. The openings according to the present invention are scattered with a regular arrangement, but the arrangement regularity, pitch, etc. are arbitrary. The series of apertures can take an array such as a lattice, a twill, a cedar twill, a staggered, a striped, a willow, a may rain, or a repetition of an irregular pattern.

The short fibers constituting the nonwoven fabric of the present invention are tightly entangled with each other and entangled with each other to constitute each section of the nonwoven fabric. It is a feature of the present invention that the entanglement is sufficiently carried out over the respective areas of the nonwoven fabric, which has heretofore been impossible with short fibers. Provides high strength, excellent dimensional stability, and high durability to withstand repeated washing. This makes it possible, for the first time, to take advantage of the various advantages provided by the short fibers mentioned above.

The entangled short length fiber surrounds the opening and forms an opening, and it is connected to each other, and the connecting parts that connect the nodules and the nodal equivalents are arranged in a regular pattern. , As a whole. Here, the connecting portion corresponds to a partition wall that partitions a pair of adjacent openings, and an area formed by intersecting a plurality of connecting portions is a nodule. First
In the drawing, an opening a, a knot b, and a connecting portion c are exemplified.

In the present invention, the short fibers are randomly curved, twisted, wrapped and intersected at these nodes and joints. Also, some of the short fibers are entangled through two or more knots and connections. The nodules and connecting parts in the present invention refer to each part that is characterized as a shape when a pattern formed by interlacing of an opening and a short fiber is regarded as a pattern on a nonwoven fabric plane. The inclusion of density, degree of entanglement, specificity in fiber arrangement, etc., is not required to be characterized thereby. Rather, the present invention is characterized in that the fiber density and the degree of entanglement between the knot and the connecting portion are relatively close.

In the present invention, the short fibers are desirably tightly entangled in each part of the nonwoven fabric. In particular, it is desirable that the degree of the confounding is 300 μm or more as the value of the distance between the confounding points. Since the entanglement is highly performed over the entire nonwoven fabric, the strength properties of the nonwoven fabric become excellent. The nonwoven fabric of the present invention is extremely excellent in dimensional stability, strength balance of vertical and horizontal directions, and delamination strength as compared with the conventional nonwoven fabric.

The method for producing a nonwoven fabric of the present invention has a fiber length of 15 mm or less,
A fiber sheet made of a short fiber having a single yarn fineness of 0.5 to 5 denier and a ratio L / D of the diameter D of the single yarn to the fiber length L of 0.8 × 10 ^{3 to} 2.0 × 10 ³ is placed on a permeable support. After performing a confounding process with a columnar water flow to form a non-porous entangled sheet, the sheet is placed on a water-permeable member having irregularities or apertures, and a high-pressure water spray angle of 5 ° or less from the surface of the entangled sheet is used. The method is characterized in that a water stream collides to move the constituent fibers of the sheet to a concave portion or an opening portion of the member, and an opening corresponding to a convex portion or a non-opening portion of the member is generated.

The non-porous entangled sheet is formed into a fiber sheet having a basis weight of 5 to 500 g / m ² depending on the use of a short fiber having a fiber length of 15 mm or less by a known method, and then a high-pressure columnar high-speed water flow. Obtained by processing. Particularly preferably, the fiber sheet is obtained by a papermaking method. Sheet uniformity,
The applicability of various fibers and the ease of mixing different kinds of fibers are also possible, and in some cases, two-layer lamination is also possible, which is a great advantage. The method for producing the non-porous entangled sheet of the present invention will be described by taking the method for forming a sheet as an example.

Prepare a cut fiber with a fiber length of 15 mm or less.
A slurry is prepared by dispersing 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 a long-mesh or round-mesh paper machine. The basis weight is preferably set in the range of 5 to 500 g / m ² depending on the application. The type of the yarn forming the papermaking sheet may be appropriately selected according to the purpose, and it is also preferable to use a mixture of two or three types of yarns having different materials and / or shapes. The obtained sheet is entangled with a high-speed water flow. Here, the high-speed water flow is a columnar water flow that is jetted at high pressure from a thin nozzle. The water pressure varies depending on the type of yarn used, the basis weight of the sheet, the relative speed of the nozzle and the sheet, etc.
The collision is carried out in the range of 200200 kg / cm ² , preferably 10-80 kg / cm ² . In the same yarn, the water pressure may be set lower as the basis weight becomes lower and higher as the basis weight becomes higher. Also, a higher pressure is required as the relative speed increases. Further, in the case of a yarn having a high Young's modulus in the case of the same basis weight, it is possible to obtain a high strength, which is the object of the present invention, by treating with a higher pressure water stream. The diameter of the nozzle for jetting the water flow is preferably 0.01 to 1 mm. The trajectory of the water flow may be a straight line parallel to the traveling direction of the papermaking sheet, or may be a curved shape obtained by a rotational motion of a header having a nozzle attached thereto or an oscillating motion reciprocating at right angles to the traveling direction of the sheet. May be. The entanglement of the multiple overlapping circular water flow trajectories obtained by the rotational movement is effective because the water jet area per sheet per nozzle per nozzle is large and efficient, and at the same time, the water flow trajectory lowers the commercial value depending on the application. This is advantageous because it has the advantage that the unevenness of the nonwoven fabric is hard to be seen and the strength ratio of the background of the nonwoven fabric is small. The method of processing the high-speed water flow on the papermaking sheet may be a method of alternately jetting the water flow on the front and back, or a method of processing only one side.
The optimum number of processing times may be selected according to the purpose.

These papermaking water pressure conditions of the columnar water stream treatment of the sheet, for example, in the case of relatively small basis weight processing papermaking sheet of 10 to 100 g / m ² is preferable to one or both surfaces treated with water pressure of 10~40kg / cm ^2, In the case of a relatively large basis weight of 150 to 500 g / m ² , it is preferable to alternately spray a columnar water stream on both sides at a water pressure of 30 to 80 kg / cm ² . Further describing the columnar water flow conditions for obtaining a confounding state with a distance between confounding points of 300 μm or less,
For example, a nozzle having an orifice diameter of 0.07 to 0.25 mm was perforated or arranged at a nozzle interval of 1 to 8 mm on a sheet made of polyethylene terephthalate (PFT) having a denier of 100 g / m ^{2 and} a short fiber having a length of 10 mm and a length of 10 mm. Using a nozzle header equipped with a large number of nozzles arranged in 10 to 20 rows, the treatment is performed once alternately with a water pressure of 30 to 50 kg / cm ² alternately.
At this time, it is preferable that the nozzle header makes a circular rotation at 50 to 500 rpm (corresponding to a sheet processing speed of 2 to 20 m / min). Further, if necessary, if the water flow trajectory remaining on the sheet surface impairs the product quality, sufficient entanglement is performed in advance with a columnar water flow, and then 40 to 100 spaces between the nozzle header and the sheet having the same structure. It is also a preferable embodiment to insert a mesh wire net to sprinkle the columnar water flow to reduce the depth of the water flow trajectory.

In a series of columnar hydroentanglement treatments, the fiber sheet is desirably placed on a permeable support. Preferred supports are fine meshes, for example nets of 60 mesh or more. It is particularly preferable that after forming the papermaking sheet on the papermaking net, preliminary confounding is carried out as it is on the papermaking net with columnar running water having a low water pressure of 3 to 30 kg / cm ² . Subsequently, the entanglement process at a high pressure can be performed. The water in the columnar water stream is drained through the sheet. When water stays on the upper surface of the sheet and water retention occurs, the entanglement of the water flow is significantly reduced. Therefore, drainage is extremely important, and it is preferable that the dewatering box disposed in contact with the back surface of the support net during the entanglement process is suctioned under reduced pressure to forcibly dewater. Thus, the non-porous entangled sheet of the present invention is obtained.

Next, the non-porous entangled sheet is placed on a water-permeable member having irregularities or holes, and a high-pressure water stream collides from the sheet surface to generate holes.

Permeable members with irregularities or holes, woven plates, sheets, fine wires or plastic wires between the holes,
Alternatively, it may be a knitted screen, a honeycomb, etc., and the irregularities and apertures may be of any shape and size, and may be of any regular pattern, for example, parallel,
They may be arranged alternately and diagonally. An example of a suitable aperture member is a 2-60 mesh plain woven screen made of wire 0.15-1.5 mm in diameter and having a pore area of 5-95%. Another example is a metal plate in which circular holes having a diameter of 0.2 to 5.0 mm are arranged in parallel or alternately in rows, and the opening area is 10 to 95%. When one opening is large, it is preferable to back up a mesh material having an opening of 80 nm or more, for example, thinner on the back surface of the opening member. That is, the member having the opening is a perforated plate or screen,
The holes are arranged in a regular pattern at a rate of 3 to 500 per 1 cm ² , and a hole area ratio of 10 to 95% is suitable.

The water flow for generating the opening is a water flow that is jetted from a nozzle having a diameter of 0.05 to 1.0 mm at a pressure of 5 to 200 kg / cm ² ,
It is particularly desirable that the water stream is in the form of a column having a jet divergence angle of 5 ° or less. The distance between the nozzles is preferably 0.5 to 10 mm, and the distance between the nozzles and the sheet surface is preferably 0 to 20 cm. A large number of nozzles are arranged on the header, and the header may be fixedly mounted or may be swung. In a preferred embodiment of the continuous treatment, the entangled sheet on the drum-shaped or net-conveyor-shaped aperture member moves under a number of jet jets. Due to the action of the jet flow, the entangled sheet is provided with apertures having various designs and patterns based on the type of aperture member used. By this process, the fibers of the entangled sheet move along the mold of the aperture member,
There is little tendency to increase entanglement between fibers. This is because the fibers are pushed into the apertures and recesses of the aperture member, and the degree of freedom for the fibers to be sufficiently entangled is relatively low. Therefore, in the present invention, it is particularly preferable that the entangled sheet is sufficiently entangled in advance in a non-porous state.

By this opening treatment, the non-perforated entangled sheet is further improved in dimensional stability and imparted with a property having sufficient durability especially for washing. Further, as a result of the opening, the liquid absorbing property becomes excellent.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

In the examples, the measured values are measured by the following methods, and all percentages are% by weight.

1) Tensile strength: JIS L 1096 strip method 2) Tear strength: JIS L 1096 single tongue method 3) Flexibility: JIS L 1096 45 ゜ cantilever method 4) Distance between confounding points: 100 times magnification with a scanning electron microscope The measurements were taken and the average value of 50 samples was taken.

The inter-entanglement distance referred to here is a value measured by the following method known in Japanese Patent Application Laid-Open No. 58-191280. Is dense. Fig. 2
FIG. 3 is an enlarged schematic diagram of the constituent fibers when the constituent fibers in the nonwoven sheet according to the present invention are observed from the surface. Constituent fibers
f _1, f _2, f ₃ ... and, in any form fibers f ₂ where the two fibers f _1, f ₂ is turned on a point of entanglement in a ₁ is under the other fibers of which will follow until the point of intersection, the point where the the intersection with a _2. Similarly, a ₃ , a _4, ... Next, the straight-line horizontal distances a _{1 to} a ₂ , a _{2 to} a ₃
Are measured, and an average value of these many measured values is determined, and this is defined as a confounding point intersection distance.

5) Delamination strength: A nonwoven sheet is cut into a width of 2.5 cm and a length of 13 cm. An adhesive tape (D320 manufactured by Sony Chemical Co., Ltd.)
After bonding 0), press at 70 ° C. for 30 seconds at a pressure of 70 g / cm ² for lamination.

A cut is made between the adhesive tape and the nonwoven sheet of the measurement sample thus obtained, and both ends are gripped with an autograph chuck to perform measurement. The autograph measurement conditions are set as follows.

Tensile strength: 10 cm / min Chart speed: 10 cm / min The measured value is indicated by the average value of three points of the highest strength and three points of the lowest strength. Such measurement is similarly performed for the nonwoven sheet in the vertical direction (MD) and the horizontal direction (CD), and the average value of the vertical / horizontal values is used as the delamination strength of the nonwoven sheet.

6) Heat seal strength: After heat-sealing the sample with a heat seal tester manufactured by Tester Sangyo, the peel strength of the heat-sealed portion is measured by the same method as in the above 5) to obtain the heat seal strength. . The heat seal conditions are as follows: The shape of the joint surface of the heat seal bar is 30cm x 2c
m, heat seal pressure 1.0 kg / cm ² , seal time 1 sec., seal temperature are set according to the object. Perform three measurements and take the average value.

7) Washing resistance: 1 to 10 test pieces of 15 cm × 15 cm were washed in a room temperature washing machine containing 3 g of detergent (new beads; Kao) at room temperature in 30 water (Toshiba Corporation, Galaxy VH-1015). Repeat washing with 10 minutes of strong washing, 10 minutes of water washing, and 3 minutes of dehydration as one cycle. The appearance change of the sample is observed every cycle. Significant change in appearance (significant fluffing at first glance,
Classification is indicated by the number of cycles in which breakage and deformation are recognized.
Those that cause a remarkable change in appearance in one cycle are classified as Class 1, and those with 5 or more cycles are classified as Class 5, and are ranked among Classes 1 to 5.

8) Dimensional stability: Based on JIS L 1096 elongation modulus A method, constant elongation is 10%, and expressed as 10% elongation elasticity after three repetitions.

Example 1 Rayon fiber having a fineness of 1.0 denier was cut into 10 mm and dispersed in water to obtain a 1% concentration slurry. Nonionic surfactant 10ppm as dispersing aid, polyacrylamide 20ppm
Was added. This slurry was formed into a sheet with a slanted long-mesh type sheeting machine to obtain a sheet having a basis weight of 60 g / m ² .

Place this sheet on a stainless steel 80 mesh wire mesh, nozzle diameter 0.2mm, nozzle pitch 5mm, nozzle row number 3
It was passed under a column of flowing water jetted at a pressure of 15 kg / cm ² from the nozzle group in the row at a moving speed of 15 m / min. The distance between the nozzle and the sheet is 30 mm, and the nozzle group performs a circular motion with a radius of 8 mm at 350 rpm.
The column-like running water was suctioned and drained from the lower surface of the wire mesh with a dehydration box. Next, the sheet was turned over and the processing under the same conditions was performed. Further, the same treatment as above was performed on both sides of the sheet under the condition that the injection pressure was 65 kg / cm ² below the nozzle group having 25 nozzle rows.

The obtained entangled sheet had a basis weight of 58 g / cm ² and a thickness of 0.35 mm, and had the following physical properties.

Tensile strength (kg / cm) Vertical 1.57, Horizontal 0.91 Tensile elongation at break (%) Vertical 19.0, Horizontal 59.0 Tear strength (kg) Vertical 0.46, Horizontal 0.57 Flexibility (mm) Vertical 45, Horizontal 26 Distance between confounding points 150 μm Delamination strength 720 g / cm Washing resistance Class 1 Dimensional stability (%) Length 30, Horizontal 43 Next, place this entangled sheet on a 20-mesh bronze plain woven wire mesh, nozzle diameter 0.15 mm, nozzle pitch 0.8 m.
m, water pressure 55 kg / from fixed nozzle header with 10 nozzle rows
under columnar water streams ejected in cm ² was passed at a traveling speed of 15 m / min. The distance between the nozzle and the sheet was 30 mm. In accordance with the pattern of the wire mesh, the cross-section of the wire became an opening of 58g /
A perforated nonwoven fabric having a pattern of m ² and a thickness of 0.48 mm was obtained.

 The physical properties and performance of this product were as follows.

Tensile strength (kg / cm) Vertical 1.51, Horizontal 0.83 Breaking elongation (%) Vertical 29.0, Horizontal 40.0 Tear strength (kg) Vertical 0.34, Horizontal 0.25 Flexibility (mm) Vertical 31, Horizontal 25 Distance between confounding points 110 μm Washability 5th class Dimensional stability (%) Length 45, width 63 Example 2 Rayon staple fiber 50 having a fineness of 1.0 denier and a cut length of 10 mm
And 50 parts of polyethylene terephthalate staple fibers having a denier of 1.0 denier and a cut length of 10 mm were dispersed in water and uniformly mixed to obtain a slurry having a concentration of 1%. 10 ppm of nonionic activator and 20 ppm of polyacrylamide were added as dispersion aids.
This slurry is formed into a sheet by a slender fourdrinier machine, and the basis weight is 50 g / m ^2.
Sheet was obtained.

This sheet was used as an entangled sheet in the same manner as in Example 1. This entangled sheet was a non-porous sheet having a basis weight of 48 g / m ² and a thickness of 0.32 mm, and had the following physical properties.

Tensile strength (kg / cm) Length 1.65, width 0.95 Elongation at break (%) Length 41, width 62 Tear strength (kg) Length 0.74, width 0.73 Flexibility (mm) Length 48, width 35 Distance between confounding points 135 μm Peel strength 1,500 g / cm Washing resistance Class 5 Dimensional stability (%) Vertical 28, horizontal 39 Next, this entangled sheet was subjected to a perforating treatment in the same manner as in Example 1. The resulting open nonwoven fabric has a similar perforated pattern, a basis weight of 46.5 g / m ² and a thickness of 0.45
mm, and the physical properties were as follows.

Tensile strength (kg / cm) Vertical 1.54, horizontal 0.92 Breaking elongation (%) Vertical 35, horizontal 54 Tear strength (kg) Vertical 0.62, horizontal 0.41 Flexibility (mm) Vertical 37, horizontal 30 Distance between confounding points 90 μm Washability Class 5 Dimensional stability (%) Length 45, width 63 Example 3 A short sheet obtained by cutting polyethylene terephthalate fiber having a fineness of 1.0 denier into 10 mm was used as a raw material to prepare a sheet in the same manner as in the above example. A confounding process was performed to obtain a confounding sheet.

Its weight was 65 g / m ² and thickness was 0.38 mm, and its physical properties were as follows.

Tensile strength (kg / cm) Vertical 5.3, Horizontal 3.0 Elongation at break (%) Vertical 42 Horizontal 66 Tear strength (kg) Vertical 1.4, Horizontal 1.0 Flexibility (mm) Vertical 63, Horizontal 50 Inter-entanglement distance 120 μm Delamination Strength 2,500 g / cm Washing resistance Class 5 Dimensional stability (%) Length 30, width 44 Next, this entangled sheet was subjected to a perforating treatment in the same manner as in Example 1. The obtained non-woven fabric with open pores had the same perforated pattern, a basis weight of 64 g / m ² and a thickness of 0.50 mm, and the physical properties were as follows.

Tensile strength (kg / cm) Vertical 5.0, horizontal 2.9 Elongation at break (%) Vertical 42, horizontal 49 Tear strength (kg) Vertical 1.8, horizontal 1.1 Flexibility (mm) Vertical 29, horizontal 27 Distance between confounding points 105 μm Washability Class 5 Dimensional stability (%) Vertical 46, horizontal 60 [Effect of the Invention] The nonwoven fabric having an aperture pattern according to the present invention is excellent in strength physical properties, excellent in durability, flexibility, and rich in liquid absorption. I have. Also excellent in morphological stability. Due to such characteristics, it is suitably used for applications such as surgical dressings, bandages, gauze, facial cloths, hand wipes, table wipes, industrial wipers, household wipers, lace curtains, and lace table cloths. In addition, it is possible to apply its excellent properties to clothing, sanitary materials, medical materials, industrial materials, and the like.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing, in an enlarged manner, a structure composed of apertures and a fiber entangled body in a nonwoven fabric having apertures according to the present invention. FIG. 2 is an enlarged schematic view of the constituent fibers of the nonwoven fabric of the present invention. a ...... opening, b ...... nodules, c ...... connecting portion, f ₁ ~f ₇ ...... constituent fibers, a ₁ ~a ₇ ...... constituent fibers entangled points between.

Claims (2)

(57) [Claims] 1. The fiber length is 15 mm or less, the single yarn fineness is 0.5 to 5 denier, and the ratio L / D of the diameter D of the single yarn to the fiber length L is 0.8 × 10 ³ to
A nonwoven fabric composed of short fibers of 2.0 × 10 ³ having openings scattered in a regular arrangement in the nonwoven fabric, and the short fibers constituting the nonwoven fabric surround the openings, forming nodules and Arranged in a regular pattern of connecting parts connecting the nodules to each other and forming an overall network, the short fibers penetrate in each area of the nodules and connecting parts and / or between the respective areas, A nonwoven fabric having an aperture pattern, characterized by being irregularly curved, twisted, wrapped, and interlaced with each other so that the inter-entanglement distance is entangled to 300 μm or less. 2. The fiber length is 15 mm or less, the fineness of a single yarn is 0.5 to 5 denier, and the ratio L / D of the diameter D of the single yarn to the fiber length L is 0.8 × 10 ³ to
A fiber sheet made by a papermaking method consisting of short fibers of 2.0 × 10 ³ is entangled by a columnar water flow on a permeable support to form a non-porous entangled sheet, and then a water-permeable member having irregularities or holes. And a high-pressure water stream having a jet divergence angle of 5 ° or less from the surface of the entangled sheet collides, and the constituent fibers of the sheet are moved to the concave portion or the opening portion of the member, and the convex portion of the member or A method for producing a paper-made nonwoven fabric having an aperture pattern, wherein an aperture corresponding to an unopened portion is formed.