Nonwoven fabric and manufacturing method thereof

Abstract

To provide a nonwoven fabric having a new design in which three areas having different patterns are regularly disposed on the whole of the nonwoven fabric by repeatedly and regularly forming two more areas at one of two entanglement parts extending in substantially one direction to constitute a stripe pattern.SOLUTION: A first entanglement part and a second entanglement part are disposed in stripe-like pattern on a nonwoven fabric. The second entanglement part at least includes a first area and a second area. In plan view, when a direction in which the first entanglement part and the second entanglement part continuously extend is an X direction and a direction orthogonal to the X direction is a Y direction, the first area and the second area are repeatedly and alternately disposed in the X direction. The first entanglement part, the first area, and the second area have different patterns from each other.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a nonwoven fabric having a novel design in which at least two entangled portions are repeatedly and regularly formed to form a striped pattern, and in one of the two entangled portions, at least two regions are repeatedly and regularly formed in the direction in which the entangled portions extend, and to a method for producing the same. [Background technology]

[0002] Nonwoven fabrics with striped (also called "striped") patterns have been proposed, for example, in Patent Documents 1 and 2. A nonwoven fabric with a striped pattern has two or more areas with different patterns formed alternately or regularly, and the pattern of each area is determined by the dimensions and / or arrangement of openings formed in that area. A nonwoven fabric with a striped pattern can enhance the designability and increase the added value of the nonwoven fabric, and therefore various striped patterns have been proposed. Furthermore, by adjusting the pattern of each area, a nonwoven fabric with a striped pattern can improve the wiping performance when used, for example, as a wiper.

[0003] Another document (Patent Document 3) proposes a patterned nonwoven fabric having a low-density region, a first high-density region, and a second high-density region, in which multiple low-density regions are gathered together to form a single island-shaped region, and in each island-shaped region, a second high-density region is formed at least between two low-density regions, and a first high-density region is formed between two island-shaped regions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-45161 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-287158 [Patent Document 3] International Publication 2017 / 164195 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a nonwoven fabric with a novel design in which two intertwined sections that extend in approximately one direction to form a striped pattern have two further regions that are repeatedly and regularly formed in one of the intertwined sections, resulting in three different patterned sections being regularly arranged throughout the nonwoven fabric. [Means for solving the problem]

[0006] In a first aspect, the present disclosure provides a nonwoven fabric in which first entangled portions and second entangled portions are arranged in a striped pattern, the second entangled portion includes at least a first region and a second region, When a direction in which the first intertwined portions and the second intertwined portions continuously extend is defined as an X direction and a direction perpendicular to the X direction is defined as a Y direction in a plan view, the first regions and the second regions are repeatedly and alternately arranged in the X direction, the first intertwined portion, the first region, and the second region have patterns different from each other; A nonwoven fabric is provided.

[0007] In the second aspect, the present disclosure provides: Producing a fibrous web; placing the fibrous web on a support and subjecting the fibrous web to an entanglement treatment using a high-pressure fluid stream; A method for producing a nonwoven fabric comprising: The support has at least two types of weaves A and B, In the support, the weave structure A and the weave structure B are belt-shaped portions extending along the direction in which the weft yarns extend, and the weave structure A and the weave structure B are regularly and repeatedly formed along the direction in which the warp yarns extend, The entanglement treatment of the fiber web placed on the support with a high-pressure fluid stream is carried out by spraying the high-pressure fluid stream onto the fiber web along the extending direction of the weft yarns of the support so that portions onto which the high-pressure fluid stream is sprayed from two or more continuous orifices of a nozzle and portions onto which the high-pressure fluid stream is not sprayed alternate with each other. A method for producing a nonwoven fabric is provided. [Effects of the Invention]

[0008] The nonwoven fabric of the present disclosure has two intertwined regions that extend in approximately one direction to form a striped pattern, and at one of these intertwined regions, two further regions are repeatedly and regularly formed, resulting in three different patterned regions regularly arranged throughout the nonwoven fabric, resulting in a unique design that resembles both a striped pattern and a checkerboard pattern. This nonwoven fabric is suitable for applications where appearance is important (e.g., cosmetics, surface materials for absorbent articles). Furthermore, for example, the nonwoven fabric of the present disclosure can be used as a wiper to wipe away dirt from the human body or articles by selecting the patterns, particularly in the first and second regions, to more effectively wipe away dirt. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a structural diagram of an example of a support used in the production of the nonwoven fabric of the present embodiment. [Figure 2] FIG. 2 is a structural diagram of an example of a support used in the production of the nonwoven fabric of the present embodiment. [Figure 3] 2 is a photograph showing the surface of a nonwoven fabric produced in Example 1, which corresponds to an example of a nonwoven fabric produced using the support of FIG. 1. [Figure 4] 3 is a photograph showing the surface of a nonwoven fabric produced in Example 2, which corresponds to an example of a nonwoven fabric produced using the support of FIG. 2. [Figure 5] FIG. 2 is a structural diagram of an example of a support used in the production of the nonwoven fabric of the present embodiment. [Figure 6] 6 is a photograph showing the surface of a nonwoven fabric produced in Example 3, which corresponds to an example of a nonwoven fabric produced using the support of FIG. 5. [Figure 7]10 is a plan view showing an acute angle a formed by the diagonal lines of the diagonal line pattern and the Y direction when the first regions formed in the second intertwined portion have a diagonal line pattern. FIG. [Figure 8] FIG. 10 is a plan view showing the distance Da between the centers of adjacent openings when the first regions formed in the second intertwined portion have a diagonal line pattern and openings are formed in the diagonal lines. [Figure 9] FIG. 10 is a plan view showing the distance Db between the centers of adjacent low-density regions when the second regions formed in the second intertwined portion have a pattern in which low-density regions are arranged in a staggered pattern. [Figure 10] FIG. 2 is a plan view showing a meandering first entangled portion in an example of the nonwoven fabric of the present embodiment. [Figure 11] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 4. [Figure 12] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 5. [Figure 13] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 6. [Figure 14] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 7. [Figure 15] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 8. [Figure 16] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 9. [Figure 17] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 10. [Figure 18] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 11. [Figure 19] 1 is a photograph showing the surface of the nonwoven fabric produced in Example 12. [Figure 20] 1 is a side cross-sectional photograph showing a method for determining the difference in height between the surface of weave structure A and the surface of weave structure B in an example of a support used in producing a nonwoven fabric of this embodiment. [Figure 21] 1 is a side cross-sectional photograph showing a method for determining the difference in height between the surface of weave structure A and the surface of weave structure B in an example of a support used in producing a nonwoven fabric of this embodiment. [Figure 22]1 is a side cross-sectional photograph showing a method for determining the difference in height between the surface of weave structure A and the surface of weave structure B in an example of a support used in producing a nonwoven fabric of this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Background to the present embodiment) In the nonwoven fabrics disclosed in Patent Documents 1 and 2, the rows or patterned portions constituting the striped pattern extend in the MD (machine direction) of the nonwoven fabric, and two or more different patterned regions are regularly arranged along the CD (transverse direction) (hereinafter, such striped patterns are referred to as "vertical stripes" for convenience). For example, when producing a nonwoven fabric using a hydroentanglement method, longitudinal stripes can be formed by regularly varying the water jetting conditions in the CD. For example, longitudinal stripes can be formed by blocking the orifice of a nozzle that jets water in a region corresponding to one of the stripe rows. Alternatively, longitudinal stripes can be formed by placing a plate with equally spaced openings between the nozzle and the fibrous web, creating areas where the water jet hits the web after passing through the openings and areas where the water jet is blocked by the plate and not hit by the water jet. Alternatively, longitudinal stripes can be formed by regularly varying the configuration (e.g., the weave of the support) of the support that transports the fibrous web during the hydroentanglement process in a direction perpendicular to the direction of travel. Furthermore, according to Patent Document 3, by making the island-shaped portions exist independently, it is possible to obtain a nonwoven fabric with, for example, a lattice pattern.

[0011] The present inventors conducted extensive research to obtain a pattern not obtainable with conventional nonwoven fabrics. As a result, by using a nozzle or plate for forming the vertical stripes and a specific support for hydroentanglement, they were able to obtain a nonwoven fabric with a unique design in which three different portions of the pattern are regularly arranged, resembling a striped pattern, a lattice pattern, or a ladder pattern. Below, we will first explain the method for producing the nonwoven fabric of this embodiment, and then explain the structure of the nonwoven fabric of this embodiment.

[0012] (Embodiment 1: Method for manufacturing nonwoven fabric) The method for producing the nonwoven fabric of this embodiment includes: Producing a fibrous web; placing the fibrous web on a support and subjecting the fibrous web to an entanglement treatment using a high-pressure fluid stream; A method for producing a nonwoven fabric comprising: The support has at least two types of weaves A and B, In the support, the weave structure A and the weave structure B are belt-shaped portions extending along the direction in which the weft yarns extend, and the weave structure A and the weave structure B are regularly and repeatedly formed along the warp yarn direction, The entanglement treatment of the fiber web placed on the support with a high-pressure fluid stream is carried out by spraying the high-pressure fluid stream onto the fiber web along the extending direction of the weft yarns of the support so that portions onto which the high-pressure fluid stream is sprayed from two or more continuous orifices of a nozzle and portions onto which the high-pressure fluid stream is not sprayed alternate with each other. A method for manufacturing nonwoven fabric.

[0013] This manufacturing method corresponds to a method in which a high-pressure fluid stream is sprayed onto a fiber web to entangle the fibers and integrate them. The high-pressure fluid is, for example, a high-pressure gas such as compressed air, or a high-pressure liquid such as high-pressure water. In the manufacture of nonwoven fabrics, a hydroentanglement process using high-pressure water as the high-pressure fluid is often used, and in this embodiment, the hydroentanglement process is preferably used from the viewpoint of ease of implementation, etc. Below, a manufacturing method in which a high-pressure water stream (hereinafter simply referred to as "water stream") is used as the high-pressure fluid stream will be described.

[0014] In this manufacturing method, a hydroentanglement treatment is partially performed on a fiber web placed on a specific support along the direction in which the weft yarns of the support extend, so that portions of the fiber web onto which a high-pressure fluid stream is sprayed from two or more continuous orifices of a nozzle alternate with portions onto which the high-pressure fluid stream is not sprayed (hereinafter referred to as "pattern-forming entanglement treatment"). In the pattern-forming entanglement treatment, portions not hit by the water stream and portions hit by the water stream alternate along the CD direction of the nonwoven fabric. Furthermore, in this manufacturing method, by performing the pattern-forming entanglement treatment using a specific support, the portions hit by the water stream can be made to have two different pattern regions, and the resulting nonwoven fabric can have three different pattern regions (a portion onto which the water stream is not sprayed, and first and second regions formed in the portions onto which the water stream is sprayed).

[0015] In this embodiment, it is desirable to subject the entire fiber web to a hydroentanglement treatment (hereinafter referred to as "overall entanglement treatment") before the pattern-forming entanglement treatment. The overall entanglement treatment is performed under the same treatment conditions over the entire fiber web. The overall entanglement treatment may also be performed so that the fiber web after the entanglement treatment has no pattern, i.e., is patternless. The overall entanglement treatment entangles the fibers to a certain extent in advance to form portions that will become first entangled portions in the resulting nonwoven fabric, and in the subsequent pattern-forming entanglement treatment, second entangled portions that are different from the first entangled portions can be formed.

[0016] The total entanglement treatment is carried out by placing the fiber web on a support and spraying a columnar water stream onto it. For example, the support is preferably a plain weave support with a mesh size of 80 mesh or more and 100 mesh or less. Using such a support, it is possible to entangle the fibers of the fiber web without forming a pattern on the fiber web and so as to achieve good texture.

[0017] The fiber web can be produced by a known method. The form of the fiber web may be any selected from, for example, a parallel web, a cross web, a carded web such as a semi-random web or a random web, an air-laid web, and a wet-laid web. In this embodiment, a carded web is preferably used because it is easy to obtain a thickness and to form irregularities.

[0018] The total entanglement treatment may be carried out by spraying water at a pressure of 1 MPa to 15 MPa from nozzles having orifices with a hole diameter of 0.05 mm to 0.5 mm spaced at intervals of 0.3 mm to 1.5 mm onto the front and back surfaces of the fibrous web, one to five times each. The water pressure is preferably 1 MPa to 10 MPa, more preferably 1 MPa to 7 MPa.

[0019] In the pattern-forming entanglement process, a support is used (hereinafter, for convenience, referred to as a "pattern-forming support"), which is a support formed by weaving warp and weft yarns and includes at least two types of weaves, A and B. Weaves A and B are strip-shaped portions extending in the direction of the weft yarns (generally perpendicular to the direction in which the support moves during nonwoven fabric production, hereinafter also referred to as the "CD direction"), and weaves A and B are regularly repeated along the direction of the warp yarns (generally the direction in which the support moves during nonwoven fabric production, hereinafter also referred to as the "MD direction"). In the pattern-forming support, weaves A and B extend across the entire width of the support in the CD direction, or across the entire width of the nonwoven fabric to be produced in the CD direction. By spraying a water stream onto the fiber web on this support, regions having patterns (including no pattern) determined by each weave are formed by rearrangement of the fibers.

[0020] In the pattern-forming support, for example, weaves A and B are arranged in the order ABAB... along the direction of the warp (MD). If the regions formed in the nonwoven fabric by weaves A and B of this support are designated as the first and second regions, respectively, then in the nonwoven fabric, two regions are formed in the order of first region-second region-first region-second region... along the MD, forming a horizontal stripe pattern (i.e., horizontal stripes) in which the first and second regions extend along the CD direction perpendicular to the MD. Furthermore, weave C can be added and arranged in the order ABCABC... along the MD. Examples of weaves include plain weave, twill weave, satin weave, and herringbone weave. For example, weave A may be a 2 / 2 twill weave, weave B a plain weave, and weave C a 3 / 1 twill weave. Using a support incorporating three or more weaves allows the resulting nonwoven fabric to have a horizontal stripe pattern in multiple regions with different surface properties. The exemplified weave may be an irregular weave, such as a broken twill weave. By using an irregular weave, floating warp yarns passing over weft yarns are dispersed, and openings or recesses formed by the floating warp yarns are dispersed, thereby imparting a unique design to the nonwoven fabric.

[0021] In this embodiment, when a water stream is sprayed onto a fibrous web placed on a pattern-forming support, a nozzle having one or more orifices arranged at predetermined intervals may be used, or a member having a plurality of holes arranged in a row in a direction perpendicular to the direction of travel of the support and not allowing the high-pressure fluid to pass through except through the holes (hereinafter simply referred to as a "perforated member") may be disposed between the fibrous web and the nozzle to form the second entangled portions. This results in continuous areas of the fibrous web not hit by the water stream in the MD during the hydroentanglement treatment, and these areas are formed at intervals in the CD. The areas not hit by the water stream and the areas hit by the water stream, where the fibers are rearranged, become first entangled portions and second entangled portions, respectively, in the resulting nonwoven fabric. The first entangled portions and second entangled portions are alternately arranged in the CD to form a striped pattern.

[0022] More specifically, when a nozzle having orifice groups arranged at predetermined intervals is used, only the water jets ejected from the orifice groups act on the web. Therefore, the high-pressure water jets with the energy required to form a pattern corresponding to the pattern-forming support act only on the portions of the web corresponding to the orifice groups. In this nozzle, the orifice groups are arranged over a section corresponding to the width of the second intertwined portion. The spacing between the orifice groups corresponds to the width of the first intertwined portion. Such a nozzle may be a nozzle designed to apply a water jet over the entire surface, as described in relation to the overall intertwining treatment, with plugged orifices in the section corresponding to the first intertwined portion. One orifice group preferably consists of two or more orifices. Using two or more orifices allows for a clearer pattern corresponding to the pattern-forming support to be formed in the second intertwined portion. The spacing between adjacent orifices in the orifice group may be, for example, 0.2 mm to 1.5 mm.

[0023] In the method of forming the second entangled portion using a perforated member, only the water flow that passes through the holes acts on the web. Therefore, the high-pressure water flow having the energy necessary to form a pattern corresponding to the pattern forming support acts only on the portion of the web corresponding to the holes. The perforated member is not particularly limited as long as it has a plurality of holes. For example, the material may be synthetic resin or metal. Furthermore, the shape may be selected appropriately depending on the hydroentanglement treatment device, such as a plate or a roll.

[0024] The multiple holes in the perforated member are formed in a direction perpendicular to the direction of travel of the support. Each hole may have a dimension of, for example, 2 mm or more, particularly 3 mm to 50 mm, and more particularly 5 mm to 30 mm, in the direction perpendicular to the direction of travel of the support. When forming second intertwined sections with different widths, holes of different dimensions are formed in one perforated member depending on the width of the second intertwined sections to be obtained. The spacing between adjacent holes in the perforated member may be, for example, 2 mm or more, particularly 3 mm to 50 mm, and more particularly 5 mm to 30 mm. The spacing between adjacent holes determines the width of the first intertwined sections, and is therefore appropriately selected depending on the width of the first intertwined sections to be obtained. The shape of the holes is not particularly limited and may be, for example, a circle, a semicircle, an ellipse, a polygon such as a triangle or a rectangle, a star-shaped polygon, a cross, or a slit-shaped shape such as a linear or curved slit.

[0025] When a perforated member is used, the nozzle is not particularly limited, and the same nozzle as that described in relation to the total entanglement treatment may be used. The distance between the perforated member and the nozzle may be, for example, 1 mm or more. If the distance between the perforated member and the nozzle is less than 1 mm, the perforated member and the nozzle may come into contact, potentially damaging one or both. On the other hand, the distance between the perforated member and the nozzle may be, for example, 30 mm or less. If the distance between the perforated member and the orifice exceeds 30 mm, the energy of the water flow may be reduced, resulting in poor pattern formation. The distance between the perforated member and the fibrous web may be, for example, 5 mm to 50 mm. If the distance between the perforated member and the fibrous web exceeds 50 mm, the energy of the water flow may be reduced, resulting in poor pattern formation.

[0026] The water pressure range that may be used in the pattern-forming entanglement treatment is the same as that described in relation to the overall entanglement treatment. The pattern-forming entanglement treatment is usually formed by spraying a water stream only once onto one side of the fiber web after the overall entanglement treatment. The pressure during the pattern-forming entanglement treatment may particularly be 1 MPa to 15 MPa, more particularly 2 MPa to 10 MPa.

[0027] In the pattern-forming entanglement process, the nozzle or perforated member is fixed in position and the pattern-forming support is advanced along the longitudinal or transverse direction (usually the longitudinal direction) of the fiber web, resulting in a nonwoven fabric having a configuration in which multiple first entangled portions and multiple second entangled portions extend linearly in the longitudinal or transverse direction of the nonwoven fabric.

[0028] In the pattern-forming entanglement process, a nonwoven fabric having a meandering configuration of first entangled portions and second entangled portions is obtained by vibrating a nozzle or a perforated member and moving a pattern-forming support along the longitudinal or transverse direction (usually the longitudinal direction) of the fiber web. Here, "vibration" means moving the nozzle or perforated member back and forth along a fixed direction. "Vibration" includes not only back and forth in a straight line but also back and forth along an elliptical orbit with a fixed direction as the major axis.

[0029] The vibration direction of the nozzle or perforated member may be appropriately selected from the longitudinal direction (MD direction), transverse direction (CD direction), and oblique direction of the web. Here, "oblique direction" means a direction along the surface of the web that forms an angle with the longitudinal or transverse direction in the range of more than 0 degrees and less than 90 degrees. Considering ease of manufacturing, the vibration direction is preferably the transverse direction or a direction that forms an angle with the transverse direction in the range of more than 0 degrees and not more than 45 degrees.

[0030] The vibration amplitude of the nozzle or perforated member is approximately the same as the amplitude of the first entangled portions in the resulting nonwoven fabric (amplitude will be described later). Therefore, the vibration amplitude of the nozzle or perforated member is determined according to the amplitude of the first entangled portions to be obtained. The meandering length per period of the first entangled portions is determined by the vibration speed of the nozzle or perforated member and the moving speed of the pattern-forming support. Therefore, the vibration speed of the nozzle or perforated member is determined according to the meandering length per period of the first entangled portions to be obtained, taking into account the moving speed of the pattern-forming support.

[0031] The vibration speed of the perforated member can be increased up to about 100 m / min. Increasing the vibration speed of the perforated member can increase the difference between the width X at the turning point of the intertwined portion, such as the first intertwined portion or the second intertwined portion, and the width Y at other points.

[0032] In the pattern-forming support used in this embodiment, the diameters of the weft a constituting weave A and the weft b constituting weave B may be different, and the weft a and the weft b may be adjacent to each other at the boundary between weave A and weave B. In addition, in the pattern-forming support, the surface of the weave A may be higher than the surface of the weave B by 0.1 mm to 3.0 mm, particularly 0.5 mm to 2.5 mm, and more particularly 0.8 mm to 2.0 mm. A support having either or both of these configurations can form a narrow third region at the boundary between the first and second regions.

[0033] The difference in surface height between weave structure A and weave structure B is determined by observing the side or cross-section of the support in the MD direction and measuring the difference between the highest point of weave structure A (usually the point where the warp threads float at the boundary between weave structure A and weave structure B) and the highest point of weave structure B. When cutting the support to observe the cross-section, the highest point of the weave may not be visible on the cross-section depending on the cut location. In this case, the highest point can be found behind the photographed cross-section, or the support can be cut in several different places and the different cut surfaces can be observed to determine the distance between the highest points of each cross-section. However, if the surface of the weave is photographed obliquely on the back side of the cross-section, the warp and weft threads at the back should be ignored when determining the surface height. Depending on the weave of the support, the highest point may be the weft thread or the warp thread.

[0034] 20 to 22 show methods for determining the difference in height between the surfaces of weave structure A and weave structure B from a side cross section of the support. FIG. 20 corresponds to the support of the weave structure shown in FIG. 1, which will be described later. In FIG. 20, a line LB is drawn that passes through the highest point on the surface of weave structure B and is parallel to the surface of the table on which the support is placed, and a line LA is drawn that passes through the highest point on the surface of weave structure A (the highest point on the surface of the weft yarn, indicated by the symbol a1), and is parallel to the surface of the table on which the support is placed. The distance between LA and LB (the distance in the direction perpendicular to the surface of the table on which the support is placed) corresponds to the difference in height between the surfaces of weave structure A and weave structure B.

[0035] Figure 21 corresponds to the support of the weave shown in Figure 2, which will be described later, and Figure 22 corresponds to the support of the weave shown in Figure 5, which will be described later. As in Figure 20, in these figures, LB is a line that passes through the highest point on the surface of weave B and is parallel to the surface of the table on which the support is placed, and LA is a line that passes through the highest point on the surface of weave A (the surface of the warp at the highest position) and is parallel to the surface of the table on which the support is placed. In Figure 21, the surface of weave B appears obliquely at the back of the side cross section, but this is ignored when determining LB.

[0036] In a support having the above configuration, a step is formed at the boundary between the two weaves, and / or a gap between the weft yarns is likely to be formed that is wider than in other areas. At this step or gap, the fiber web is subjected to the action of the water flow under conditions different from those of the fiber web in weave structures A and B, and / or is affected by suction during the hydroentanglement treatment. As a result, a third area having a pattern different from both the first and second areas may be formed as a narrow area.

[0037] Furthermore, at the boundary between weave structure A and weave structure B, due to factors such as a change in the diameter of the weft yarn and a change in the weave structure, a portion (called a "knuckle") is formed in which the state of the floating warp yarn differs from the floating warp portions in weave structure A and weave structure B, and it is believed that this knuckle forms an opening in the third region of the resulting nonwoven fabric. Furthermore, at the boundary, the weft yarn may, for example, meander and assume a different state from other portions, which is also thought to be a factor in the formation of the third region and / or determine the pattern in the third region.

[0038] In this embodiment, the pattern-forming support may be one in which twill weave portions as weave structure A and plain weave portions as weave structure B are alternately formed along the direction of travel. In such a support, the diameter of weft thread a may be larger than the diameter of weft thread b. Examples of such pattern-forming supports will be described below, showing weave structures.

[0039] The twill weave portion of weave structure A may be, for example, a weft twill weave with two or more floating weft yarns and one floating warp yarn. Figure 1 is a weft twill weave diagram of a support on which weave structure A, a 1 / 7 weft twill weave portion, and weave structure B, a plain weave portion, are formed. Figure 2 is a weft twill weave diagram of a support on which weave structure A, a 1 / 3 weft offset twill weave portion, and weave structure B, a plain weave portion, are formed. In the weft structure diagram, the colored portions represent warp yarns floating above the weft yarns. Note that Figures 1 and 2, as well as Figure 5 described below, schematically illustrate the repetition of weave structure A and weave structure B, and the numbers of warp and weft yarns constituting each weave shown in the figures are illustrative. Examples of nonwoven fabrics produced using the supports shown in these figures are shown in Figures 3, 4, and 6. However, the numbers of warp and weft yarns in each region of the supports actually used to produce these nonwoven fabrics may differ from those shown.

[0040] In the pattern forming support of Figure 1, knuckle a is formed at the boundary between the two weaves by the floating portion of the warp. In Figure 1, knuckle a is formed by the warp floating on wefts a and b. In other parts, the warp floats on one weft, and it can be seen that knuckle a is formed by the floating of the warp in a different state from the other parts. After the overall entanglement process, the fiber web is placed on the pattern-forming support and subjected to the pattern-forming entanglement process using a nozzle with a group of orifices spaced at predetermined intervals. This produces a nonwoven fabric with a pattern as shown in FIG. 3. The nonwoven fabric of FIG. 3 has a first entangled portion that was not hit by the water flow during the pattern-forming entanglement process and a second entangled portion formed by the pattern-forming entanglement process. The second entangled portion has a first region with a diagonal line pattern imparted by a twill weave portion (weave structure A) and a second region formed by a plain weave portion (weave structure B) with openings or recesses arranged in a staggered pattern. Furthermore, the second entangled portion has a third region, a stitch-like region with relatively clearly formed openings, regularly arranged in the order of the first region, the third region, and the second region. The configuration of the nonwoven fabric will be described in detail in embodiment 2.

[0041] In the second entangled portion of the nonwoven fabric shown in Figure 3, a third region is formed only at the boundary with the first region on the lower side of the figure, as viewed from one second region. The third region is formed by sequentially spraying water from the fiber web at a lower position (weave structure B) on the support to the fiber web at a higher position (weave structure A) when spraying water onto the fiber web while the support is moving during the pattern-forming entanglement process. As the support moves forward, the fiber web extending from the lower position to the higher position is more likely to firmly receive the water flow and be affected by the water flow, which is thought to make knuckles at the step more easily reflected in the nonwoven fabric. On the other hand, at the other step where the water flow is sprayed from the fiber web at the higher position (weave structure A) to the fiber web at the lower position (weave structure B), part of the water flow "flows down" over the fiber web extending from the higher position to the lower position and is not firmly received by the fiber web, which is thought to result in a weaker degree of entanglement. As a result, it is believed that openings and / or recesses are difficult to form, the third region having a distinct pattern is not formed, and a nonwoven fabric such as that shown in FIG. 3 is obtained.

[0042] In the pattern-forming support of Figure 2, knuckle a is a warp yarn floating above one weft yarn. Knuckle a is a portion where the warp yarn passes over thick weft yarn a, but before and after the knuckle a in the direction of travel, the warp yarn passes over thin weft yarn b. Therefore, the arrangement of the weft yarns (especially the spacing between weft yarns) in the vicinity of knuckle a differs from the arrangement of the weft yarns in other weaves, and it is thought that knuckle a therefore forms a characteristic opening and / or openings in the third region of the second interlaced portion.

[0043] After the overall entanglement process, the fiber web is placed on the support shown in FIG. 2 and subjected to a pattern-forming entanglement process using a nozzle with a group of orifices arranged at predetermined intervals. This produces a nonwoven fabric with a pattern as shown in FIG. 4. The nonwoven fabric shown in FIG. 4 has a first entangled portion formed by the overall entanglement process and a second entangled portion formed by the pattern-forming entanglement process. The second entangled portion has a first region in which openings provided by the twill weave portion (weave structure A) are regularly arranged, and a second region in which openings or recesses are arranged in a staggered pattern, formed by the plain weave portion (weave structure B). In addition, in the second entangled portion, a third region, a stitch-like region with clearly formed openings, is regularly formed from the top to the bottom of the figure in the order of first region → third region → second region. The structure of the nonwoven fabric will be described in detail in Embodiment 2. In the first region of the second entangled portion of the nonwoven fabric shown in FIG. 4, relatively clear openings are formed at positions corresponding to the portions where the warp yarns are floating in the weave structure A. This is thought to be because weave structure A is a 1 / 3 weft-break twill weave, and the curvature of the floating warp yarns is stronger and the floating warp yarns are more raised than in weave structure A of the support in Figure 1, for example, and because there is a floating warp yarn diagonally adjacent to the floating warp yarn, and these together can be considered to form a large convex portion. Also, in weave structure A of the support in Figure 2, the floating warp yarns do not form continuous diagonal lines, so a diagonal line pattern is unlikely to form in the first region of the obtained nonwoven fabric.

[0044] The nonwoven fabric shown in Fig. 4 also has a configuration in which the first region → the third region → the second region are repeatedly formed in the second entangled portion, and the third region is formed only at the boundary between one second region and the first region on the lower side of the figure. The reason for the formation of the third region in this way is thought to be the same as that explained with reference to Fig. 3 above.

[0045] The weave structure A of the pattern formation support is not limited to one with one warp float, and may be a twill weave with two or more warp floats. The upper limit of the number of warp floats may be, for example, 16, and particularly 10. In this case, the number of weft floats may be, for example, 2 or more and 16 or less, and particularly 2 or more and 10 or less. For example, the pattern formation support may be one in which a weave structure A that is a 2 / 2 twill weave and a weave structure B that is a plain weave are formed, as shown in the weave diagram of Figure 5.

[0046] A twill weave portion, in which the number of floating warp yarns is two or more, forms a characteristic knuckle at the boundary with the plain weave portion. As shown in Figure 5, a knuckle N1, which floats on three or more consecutive weft yarns including the weft yarn a and the weft yarn b, is formed at one boundary of the twill weave portion and the plain weave portion. Because this knuckle N1 is long in the vertical direction, it tends to form a vertically long opening at the boundary between the first and second regions.

[0047] 5, a knuckle N2 is formed at the boundary opposite to the boundary on the side where knuckle N1 is formed, in which a warp yarn floats on two or more continuous weft yarns including weft yarn a and weft yarn b, and a knuckle N3 is formed adjacent to one side of knuckle N2, in which a warp yarn floats on two or more continuous weft yarns. Because knuckles N2 and N3 are formed closely to each other, in the resulting nonwoven fabric, a region where two adjacent openings or two openings are joined to form one larger opening is formed between the first region and the second region.

[0048] In a weave, as in the support shown in Figure 5, when the number of warp floats (the number of wefts on which successive warp threads lie) and the number of weft floats (the number of warp threads on which successive weft threads lie) are the same, the numbers of warp and weft floats will be the same on both main surfaces. Such a support makes it possible to produce nonwoven fabrics with substantially the same pattern regardless of which main surface the fibrous web is placed on. However, in the twill weave portion, the direction of the diagonal lines formed by the warp threads is mirror image between the two main surfaces, and the direction of the diagonal lines formed in the resulting nonwoven fabric will be opposite.

[0049] FIG. 6 shows an example of a nonwoven fabric produced by performing a total entanglement process, placing a fiber web on the support shown in FIG. 5, and then performing a pattern-forming entanglement process using a nozzle with a group of orifices arranged at predetermined intervals. The nonwoven fabric shown in FIG. 6 was produced by performing a hydroentanglement process during the pattern-forming entanglement process so that the boundary where the knuckles N1 were formed was sprayed first with the water stream, i.e., with the arrow shown on the right side of the weave diagram in FIG. 5 as the direction of travel. In the nonwoven fabric shown in FIG. 6, the first region of the second entangled portion has a diagonal line pattern in which diagonal lines with openings and diagonal lines without openings are alternately arranged. The openings correspond to the areas where warp yarns float in the twill portion of FIG. 5. Since the warp yarns floating above two weft yarns in the twill portion are adjacent to each other, relatively clear openings are formed in the nonwoven fabric.

[0050] The second interlaced portion of the nonwoven fabric in Figure 6 has a third region formed corresponding to the boundary including knuckle N1 and a fourth region formed corresponding to the boundary including knuckles N2 and N3. The four regions are repeatedly formed in the order of first region → third region → second region → fourth region. Both the third and fourth regions have patterns different from those of the first and second regions, emphasizing the boundary between the first and second regions. Because knuckle N1 is long and floats above the three weft yarns, the opening in the third region is larger than the opening formed in the first region, and the direction of the diagonal lines formed by the opening in the first region appears to be changed in the third region. Because knuckle N2 passes over the weft yarns constituting weave A and the weft yarns constituting weave B at the boundary between weaves A and B, the warp yarns on the weave B side reach a lower position before passing under the weft yarns of weave B. This is thought to be what makes the pattern of the fourth region different from the other regions. Furthermore, at the boundary between weave structures A and B, the spacing between weft threads tends to be wider than that in weave structures A and B, which is also thought to make the patterns in the third and fourth regions different from those in the other regions.

[0051] In the nonwoven fabric shown in Figure 6, regions with a different pattern from the first and second regions are formed at the upper and lower boundaries of the second region formed on the second support. At knuckles N2 and N3, the warp yarns float above two weft yarns, making them relatively large. Therefore, even when water flows sequentially across a fiber web spanning from high to low positions, the knuckles are likely to affect the fibers. This is thought to have resulted in a clearer pattern than the supports shown in Figures 1 and 2 (where the knuckle at the boundary of the weave on the rear side in the direction of travel has only one warp yarn floating).

[0052] The illustrated pattern-forming support is an example, and weaves A and B may be weaves other than those shown in the drawings. The width in the MD direction of each weave, the diameter of the wefts a and b, and the diameter of the warp are also appropriately selected so as to obtain a desired striped pattern or ladder pattern, and a desired pattern of the first and second regions in the second intertwined portion.

[0053] In the pattern-forming support, the MD dimensions of the weave structures A and B determine the MD dimensions of the first and second regions formed in the second entangled portions in the resulting nonwoven fabric (i.e., the X-direction dimensions when the direction in which the first and second entangled portions extend is the X-direction). In this embodiment, the MD dimension of the weave structure A may be 2 mm to 200 mm, particularly 3 mm to 100 mm, more particularly 5 mm to 50 mm, even more particularly 7 mm to 30 mm, and even more particularly 10 mm to 25 mm. Similarly, the MD dimension of the weave structure B may be 2 mm to 200 mm, particularly 3 mm to 100 mm, more particularly 5 mm to 50 mm, even more particularly 7 mm to 30 mm, and even more particularly 10 mm to 25 mm. The MD dimension of the weave structure A may be the same as or different from the MD dimension of the weave structure B. Furthermore, in one support, there may be a plurality of weave structures A with different dimensions in the MD direction, and / or there may be a plurality of weave structures B with different dimensions in the MD direction.

[0054] The warp and weft yarns constituting the pattern-forming support may be filaments with a diameter of, for example, 0.3 mm to 1.2 mm. The diameter of the weft yarn may be, for example, 0.5 mm to 1.2 mm, particularly 0.9 mm to 1.0 mm, and more particularly 0.65 mm to 0.95 mm. Weft yarns a and b may have different diameters. In this case, the difference in diameter between weft yarns a and b may be, for example, 0.1 mm to 0.8 mm, particularly 0.2 mm to 0.7 mm, and more particularly 0.3 mm to 0.6 mm. The greater the difference in diameter between weft yarns a and b, the clearer the pattern in the third and fourth regions of the resulting nonwoven fabric tends to be. However, if the difference is too large, weave B and the fiber web may not come into contact near the boundary between weaves A and B (large gaps may result), making it difficult to form a clear pattern. The warp threads constituting the support are common to both weaves A and B, and the thickness of the warp threads is the same in both weaves A and B.

[0055] The diameter of the warp and weft yarns is the length of the longest line segment connecting any two points on the cross section (a cross section obtained by cutting perpendicularly to the length) of the yarn (e.g., filament). The diameter can also be determined in this way for filaments with an elliptical, polygonal, star-shaped, etc. cross section. However, as will be described later, for filaments with a flat cross section (including a rectangle with rounded corners), the dimensions of the short and long sides of the rectangle circumscribing the cross section are used as an index of thickness.

[0056] The warp and weft yarns constituting the pattern-forming support may be monofilaments having a flat cross section, and a rectangle circumscribing the cross section may have a short side of 0.2 mm to 0.8 mm and a long side of 0.3 mm to 1.2 mm. The short side of the circumscribing rectangle may be particularly 0.4 mm to 0.6 mm, and the long side may be particularly 0.7 mm to 0.9 mm. Here, "flat shape" refers to a shape with a large dimension in one direction, such as a rectangle (oblong), an oblong, or a rectangle with rounded corners, whose dimensions and shape are difficult to grasp solely from the diameter determined by the above method. When the cross section is a perfect rectangle, the short and long sides of the rectangle will have dimensions within the above ranges. The ratio of the long side to the short side of the circumscribing rectangle (long side / short side ratio) may be, for example, 1.2 or more, particularly 1.3 to 3, and more particularly 1.4 to 2.

[0057] In this embodiment, the warp yarns constituting the pattern-forming support preferably have a flat shape. When flat warp yarns are used, the contact area between the warp yarns and the fiber web increases compared to when warp yarns with a circular cross section are used, and the areas of openings and / or recesses formed by the floating portions of the warp yarns, including knuckles, tend to become larger.

[0058] The warp and weft threads constituting the pattern-forming support may be made of one or more materials selected from polyester, polyamide, polyolefin, polyether ether ketone, polyphenylene sulfide, and the like. The warp and weft yarns may be in a form other than monofilament, such as multifilament or spun yarn. In the case of multifilament or the like, the fineness may be used instead of the diameter as an indicator of the thickness of the yarn, and weft yarns a and b having different finenesses may be used.

[0059] The weave density of the pattern-forming support may be, for example, 6 to 123 threads / inch for the warp yarns, particularly 10 to 80 threads / inch, and more particularly 20 to 40 threads / inch. The weave density of the weft yarns may be, for example, 6 to 123 threads / inch, particularly 8 to 60 threads / inch, and more particularly 10 to 20 threads / inch. The higher the weave density, the more easily the nonwoven fabric can be imparted with a clearer pattern by the portions where the warp yarns, including the knuckles, are raised. However, if the weave density is too high, the smoothness of the portions where the warp yarns, including the knuckles, are raised will increase, which may actually reduce the clarity of the pattern.

[0060] When weave structure A is a twill weave, the shape of the diagonal pattern in the first region varies depending on the diameter of the monofilaments, the warp density, and the weft density, as well as the number of warp threads floating above the weft threads and / or the number of warp threads sinking below the weft threads in the twill weave. In a twill weave, the warp threads may or may not be adjacent to each other at the floating positions above the weft threads. When the floating warp threads are connected by a straight line, if a diagonal line extending diagonally can be drawn that includes all the floating warp threads, a first region with a diagonal pattern as shown in Figures 3 and 6 is obtained. If such a straight line cannot be drawn, a first region with a pattern in which the arrangement of openings or recesses is less regular, as shown in Figure 4, is obtained.

[0061] When the weave structure B is a plain weave portion, the size of the openings formed in the second region varies depending on the diameter of the monofilaments that make up the structure, and the area of ​​the openings or recesses tends to increase as the diameter of the monofilaments increases. Furthermore, the spacing between openings, between openings and recesses, or between recesses varies depending on the weft density and warp density of the plain weave portion, and the spacing tends to decrease as the weft density and / or warp density increases.

[0062] In the pattern-forming support, weaves A and B may both be plain weaves. In this case, the two weaves can be made different from each other by changing the diameter of the weft yarns and / or the density of the weft yarns. Alternatively, weaves A and B may both be twill weaves. In this case, the two weaves can be made different from each other by using one method selected from the group consisting of changing the number of warp yarns floating above the weft yarns, changing the number of warp yarns sinking below the weft yarns, changing the diameter of the weft yarns, etc.

[0063] If weave B is a plain weave portion with a fine mesh (for example, 80 mesh or more and 100 mesh or less), a second region without a pattern is formed corresponding to the weave. In this case, weave A may be a weave in which a pattern can be formed, such as a twill weave, or a plain weave portion made of large-diameter filaments.

[0064] After the pattern-forming entanglement treatment, the fiber web is subjected to a drying treatment to obtain the nonwoven fabric of the second embodiment described below. The nonwoven fabric of the second embodiment corresponds to that already described with reference to Figures 3, 4, and 6, and its configuration will be described in detail below.

[0065] When the fibrous web contains adhesive fibers, a bonding treatment may be carried out simultaneously with or after the drying treatment, so that the fibers are bonded together in the resulting nonwoven fabric. The bonding treatment may be a thermal bonding treatment, or bonding by electron beam irradiation, or ultrasonic welding. By using a heat treatment, the adhesive fibers (e.g., low-melting point components of the composite fibers) melt or soften by heat during the heat treatment, thereby bonding the fibers constituting the fibrous web together. By using a heat treatment, the drying treatment can be carried out simultaneously.

[0066] The heat treatment may be, for example, a hot air processing treatment in which hot air is blown, a heat roll processing (heat embossing roll processing), or a heat treatment using infrared rays. The hot air processing treatment may be carried out using a device that blows hot air at a predetermined temperature onto the fiber web, for example, a hot air penetration type heat treatment machine or a hot air blowing type heat treatment machine.

[0067] The heat treatment temperature (e.g., the temperature of the hot air) may be a temperature at which the component that constitutes the adhesive fiber and functions as an adhesive component softens or melts. For example, the heat treatment temperature may be a temperature equal to or higher than the melting point of the component. For example, when the adhesive fiber contains polyethylene as a component and polyethylene is used as the adhesive component, the heat treatment temperature may be 130°C to 150°C.

[0068] (Embodiment 2: Nonwoven fabric) The nonwoven fabric described as embodiment 2 is a nonwoven fabric in which the first entangled portions and the second entangled portions are arranged in a striped pattern, the second entangled portion includes at least a first region and a second region, When a direction in which the first intertwined portions and the second intertwined portions continuously extend is defined as an X direction and a direction perpendicular to the X direction is defined as a Y direction in a plan view, the first regions and the second regions are repeatedly and alternately arranged in the X direction, the first intertwined portion, the first region, and the second region have patterns different from each other; It is a nonwoven fabric.

[0069] [First intertwined part, second intertwined part] The nonwoven fabric of this embodiment has first entangled portions and second entangled portions, which are arranged in a striped pattern. Both the first and second entangled portions are formed by entanglement of fibers and extend in one direction of the nonwoven fabric. In this embodiment, the direction in which the first and second entangled portions extend is defined as the X direction, and the direction perpendicular to the X direction is defined as the Y direction. The X direction may be the machine direction (also referred to as the "MD direction") or the cross direction (also referred to as the "CD direction") of the nonwoven fabric, or may be a direction forming an angle with the MD or CD direction.

[0070] As described below, the first and second entangled portions may be meandering. In this case, when the two types of entangled portions meander between two straight lines parallel to the MD direction of the nonwoven fabric, the first and second entangled portions are considered to extend along the MD direction of the nonwoven fabric, and the X direction is considered to be the MD direction. Similarly, when the first entangled portions meander between two straight lines parallel to the CD direction of the nonwoven fabric, the first entangled portions are considered to extend along the CD transverse direction of the nonwoven fabric, and the X direction is considered to be the CD direction.

[0071] The first intertwined portion and the second intertwined portion are distinguished by the different patterns they have. Here, "pattern" also includes "no pattern." "No pattern" refers to a state without a sense of design, such as a formation unevenness that inevitably occurs during web formation or nozzle streaks that inevitably occur during hydroentanglement, but without any intentional pattern. More specifically, if a protrusion, recess, or opening has a longest dimension (excluding the dimension in that direction if it extends continuously in one direction, such as a nozzle streak) of 0.1 mm or less, such a protrusion, recess, or opening is not considered to form a pattern.

[0072] The first entangled portions may have no pattern. As described in the first embodiment, when the nonwoven fabric of this embodiment is produced by performing a pattern-forming entanglement treatment after the overall entanglement treatment, the first entangled portions have a pattern determined by the support used in the overall entanglement treatment. When a support with a large number of meshes is used in the overall entanglement treatment, the first entangled portions are formed without a pattern.

[0073] The second intertwined portions have first and second regions alternately formed along the X direction, and may further have a narrow third region at the boundary between the first and second regions, or may have narrow third and fourth regions at the boundary between the first and second regions. The first to fourth regions will be described later. The nonwoven fabric of this embodiment exhibits a unique design effect that is not a simple striped pattern, due to the second intertwined portions having two or more regions, with the first intertwined portions having a uniform pattern in one direction and the second intertwined portions having a horizontal striped or ladder-like appearance.

[0074] The dimension in the Y direction of each first intertwined part (hereinafter referred to as "width" for convenience) may be, for example, 2 mm to 200 mm, particularly 3.5 mm to 100 mm, more particularly 4 mm to 50 mm, and even more particularly 5 mm to 30 mm, or 5 mm to 15 mm. The width of one first intertwined part may or may not be constant.

[0075] The nonwoven fabric may have primary entangled portions of different widths. For example, primary entangled portions of narrow width (e.g., 2 mm to 5 mm) and primary entangled portions of wide width (e.g., 6 mm to 15 mm) may be arranged alternately. Alternatively, primary entangled portions of narrow width (e.g., 2 mm to 3 mm), primary entangled portions of medium width (e.g., 4 to 5 mm), and primary entangled portions of wide width (e.g., 6 to 15 mm) may be arranged in the order of thin / medium / wide or thin / wide / medium.

[0076] The width of each second intertwined portion may be 2 mm to 200 mm, particularly 3.5 mm to 100 mm, more particularly 4 mm to 50 mm, and even more particularly 5 mm to 30 mm, or 5 mm to 15 mm. The width of one second intertwined portion may or may not be constant.

[0077] In the nonwoven fabric, second intertwined portions of different widths may be present. For example, second intertwined portions of narrow width (e.g., 2 mm to 5 mm) and second intertwined portions of wide width (e.g., 6 mm to 15 mm) may be arranged alternately. Alternatively, second intertwined portions of narrow width (e.g., 2 mm to 3 mm), second intertwined portions of medium width (e.g., 4 to 5 mm), and second intertwined portions of wide width (e.g., 6 to 15 mm) may be arranged in the order of narrow / medium / wide or narrow / wide / medium.

[0078] In the nonwoven fabric, the first entangled portions may be straight or serpentine. When the first intertwined parts are meandering, the meandering length per period (i.e., wavelength) may be 5 mm or more. The meandering length per period is determined as follows. i) As shown in FIG. 10, the direction parallel to the line perpendicular to the X direction 31 in which the first intertwined portion 42 extends (i.e., the Y direction) is defined as the orthogonal direction, the direction extending toward the "+" side is defined as the positive orthogonal direction 32a, and the direction extending toward the "-" side is defined as the negative orthogonal direction 32b. ii) At point e where the meandering progression of the first intertwined portion 42, which had been progressing toward the negative orthogonal direction 32b (because the first intertwined portion 42 has width, focus is on the progression of one end in the width direction (the left end in the figure)), changes to the positive orthogonal direction 32a, a straight line 33 perpendicular to the length direction 31 is drawn. iii) The meandering of the first intertwined portion 42, which had been moving from point e toward the positive orthogonal direction 32a, moves toward the negative orthogonal direction 32b, and then changes to the positive orthogonal direction 32a at point f, where a straight line 34 perpendicular to the longitudinal direction 31 is drawn. iv) The distance l between the straight lines 33 and 34 is the length of the meandering per period. At a point where the meandering progression of the first intertwined portions 42 changes from the negative orthogonal direction 32b to the positive orthogonal direction 32a, if the first intertwined portions 42 move straight in the length direction 31 (for example, if they meander like a square wave), straight lines 33 and 34 are drawn at the midpoints of the straight portions, intersecting at right angles to the length direction 31. In FIG. 3, reference numeral 41 denotes second intertwined portions formed between the first intertwined portions 42.

[0079] In this embodiment, the upper limit of the wavelength may be 200 mm. The wavelength is particularly from 10 mm to 150 mm, and more particularly from 30 mm to 100 mm. This allows the meandering pattern to be clearly visible in the nonwoven fabric.

[0080] The meandering of the first intertwined parts preferably has an amplitude of 1 mm or more. The amplitude is determined as follows. i) As shown in FIG. 10, a point on the above-mentioned straight line 33 that equally divides the width of the first intertwined portion 42 is designated as g. ii) At point i where the meandering progression of the first intertwined portion 42, which had been moving in the positive orthogonal direction 32a, changes to the negative orthogonal direction 32b, draw a straight line 35 perpendicular to the length direction 31, and define h as a point on the straight line 35 that equally divides the width of the first intertwined portion 42. iii) The distance j between a line 36 that includes point g and is parallel to the length direction 31 and a line 37 that includes point i and is parallel to the length direction is defined as the amplitude. The upper limit of the amplitude may be 200 mm. The amplitude is particularly from 2 mm to 150 mm, more particularly from 5 mm to 100 mm, and even more particularly from 10 mm to 50 mm.

[0081] The meandering of the first intertwined portions may have different lengths per cycle, or may have different amplitudes like damped waves, and these meandering patterns may be repeated regularly. A preferred meandering configuration is one in which the meandering length per cycle is the same and the amplitude is the same, i.e., the same pattern is repeated. Such meandering first intertwined portions give an impression of order. Furthermore, when the nonwoven fabric is appropriately cut into products, such meandering first intertwined portions do not give the impression of significant differences in design between products.

[0082] The ratio of the length per period (wavelength) of the meandering to the amplitude (wavelength / amplitude) may be, for example, 1 to 15, particularly 1.5 to 12, and more particularly 2 to 8. If the ratio of the wavelength to the amplitude is less than 1 or exceeds 15, it may be difficult to recognize that the first intertwined portions are meandering. Fig. 3 shows an example in which the meandering phases of adjacent first intertwined portions are the same. The meandering phases of adjacent first intertwined portions may be shifted.

[0083] When a nonwoven fabric has only first and second entangled portions and the first entangled portions are meandering, the second entangled portions adjacent to the first entangled portions also meander. In this case, the length and amplitude of the meandering per period of the second entangled portions are determined by those of the first entangled portions. Therefore, a description of the length and amplitude of the meandering per period of the second entangled portions is omitted here.

[0084] [Areas 1 to 3, and Area 4] Next, the first and second regions formed in the second intertwined portion, and the third and fourth regions formed as needed, will be described. These regions exist in stripes and have different patterns. Here, the meaning of "pattern" is as explained above with respect to the first intertwined portion and the second intertwined portion. In this embodiment, these regions are regularly arranged in the X direction. For example, when the second intertwined portion has a first region and a second region, the first region and the second region may be arranged alternately and repeatedly. When the second intertwined portion further has a third region, the first region, the third region, and the second region may be formed in this order. Note that the repetition of the first → third → second in one direction becomes the repetition of the first → second → third in the opposite direction.

[0085] The patterns of the first and second regions are not particularly limited as long as they have different patterns from each other. For example, the first region may have no pattern and the second region may have a pattern.

[0086] The pattern may be formed by, for example, regularly arranging regions of lower fiber density ("low-density regions") and regions of higher fiber density ("high-density regions") In this case, the low-density regions may be a regular pattern, such as at least one pattern selected from the group consisting of a dot pattern, a herringbone pattern, a checkerboard pattern, a grid pattern, a houndstooth pattern, a diagonal (twill) pattern, a satin pattern, a wave pattern, and a zigzag pattern.

[0087] The low-density region may be a recess that is thinner than the high-density region and recessed from the high-density region, or an opening where no fibers are present. A single region may contain both recesses and openings as low-density regions. In particular, when forming openings, depending on the manufacturing conditions, it may not be possible to form all of the low-density region into openings, and some of the low-density region may exist as recesses. Such a configuration is also permitted in this embodiment.

[0088] In this embodiment, the pattern of the first region is preferably a diagonal line pattern. The diagonal line pattern is a pattern in which low-density regions and high-density regions extending diagonally are alternately arranged, and in this embodiment, the "diagonal direction" refers to a direction that is not parallel to the MD and CD directions of the nonwoven fabric. The diagonal line pattern region tends to improve wiping performance, for example, when the nonwoven fabric is used as a wiper.

[0089] When the first region has a diagonal line pattern, the acute angle a (see FIG. 7 ) formed between the diagonal lines of the diagonal pattern and the extension direction of the first region may be 10 degrees or more and 80 degrees or less, particularly 15 degrees or more and 75 degrees or less, and more particularly 20 degrees or more and 70 degrees or less. If the acute angle a is too small, the direction of the diagonal lines will approach the extension direction of the first region (Y direction). If the acute angle a is too large, the direction of the diagonal lines will approach the direction perpendicular to the extension direction of the first region (X direction), making the diagonal line pattern difficult to recognize. Furthermore, whether the acute angle a is too small or too large, when the nonwoven fabric is used as a wiper, it will be difficult to achieve improved wiping performance.

[0090] When the first region has a diagonal line pattern, diagonal lines S1, in which openings or recesses are arranged in a straight line, and diagonal lines S2, in which openings or recesses are not formed or, if they are formed, openings or recesses are formed that are smaller than the openings or recesses of diagonal lines S1, may be arranged alternately. The diagonal lines S1 are formed by using a support having a twill weave portion as the weave structure A, in which the number of warp floats is two or more, such as the support described with reference to Figure 5. When openings or recesses are formed in the diagonal lines S1, the area M1 of one opening or recess is, for example, 0.3 mm 2 More than 3mm 2 It may be less than or equal to 0.5 mm, in particular 2 Over 2.7mm 2 Below, more particularly 0.7 mm 2 Over 2.5mm 2 The average diameter of one opening or recess may be, for example, 1 mm or more and 5 mm or less, particularly 1.2 mm or more and 4 mm or less, and more particularly 1.5 mm or more and 3 mm or less. Here, the average diameter of an opening or recess refers to the longest length of a line segment connecting any two points on the outline forming the opening, and the average diameter is expressed as the average of the diameters of five or more openings or recesses formed in one region. When the opening or recess is elliptical, the major axis is the diameter of the opening.

[0091] If the area or average diameter of the openings or recesses formed in the first region is too large, the strength of the nonwoven fabric may decrease. Furthermore, if openings are formed and the area or average diameter of the openings is too large, for example, when the nonwoven fabric is used as a wiper, the wiped dirt may adhere to the hand or tool through the openings, or the wiped dirt may be easily detached from the openings. If the area or average diameter of the openings or recesses formed in the first region is too small, the presence of the openings or recesses may be difficult to notice, and the design effect may not be achieved.

[0092] In addition, the distance between the openings, recesses, or between an opening and a recess in the diagonal line S1 may be, for example, 0.5 mm to 4.5 mm, particularly 0.7 mm to 4.0 mm, and more particularly 1.0 mm to 3.5 mm. Here, the distance between the openings, recesses, or between an opening and a recess refers to the shortest line segment connecting the centers of all combinations of adjacent openings and recesses. In the case of openings or recesses formed along a diagonal line, the distance between the openings is the distance indicated by the symbol Da in FIG. 8.

[0093] The second region may have a pattern in which openings or recesses are regularly arranged. The pattern in which openings or recesses are regularly arranged may be, for example, a pattern in which openings or recesses are arranged in a staggered pattern, a pattern in which openings or recesses are arranged in a square pattern, or the like. In the pattern in which openings or recesses are regularly arranged, the distance between openings, recesses, or between an opening and a recess may be, for example, 1.0 mm or more and 4.0 mm or less, particularly 1.3 mm or more and 3.0 mm or less, and more particularly 1.6 mm or more and 2.5 mm or less. Here, the meaning of the distance between openings, recesses, or between an opening and a recess is as explained in relation to the oblique line S1 that may be formed in the first region. Therefore, for example, when openings or recesses are formed in a staggered pattern as shown in FIG. 9, the shortest distance between the centers of adjacent openings or recesses is the distance indicated by the symbol Db.

[0094] When the second region is a pattern formed by regularly arranging openings or recesses, the area M2 of one opening or recess is, for example, 1.0 mm 2 It may be less than or equal to 0.8 mm, in particular 2 Below, more particularly 0.6 mm 2 The lower limit of the area of ​​the opening or recess may be, for example, 0.01 mm 2 In particular, 0.02 mm 2 , more particularly 0.03 mm 2The average diameter of the openings or recesses may be, for example, 0.5 mm or more and 4.0 mm or less, particularly 0.6 mm or more and 3.5 mm or less, and more particularly 0.7 mm or more and 3 mm or less. If the area of ​​the openings or recesses is too large or the average diameter is too large, the strength of the nonwoven fabric may decrease. Furthermore, if openings are formed and the area or average diameter of the openings is too large, when the nonwoven fabric is used as a wiper, the wiped dirt may adhere to the hand or tool through the openings, or the wiped dirt may easily detach from the openings.

[0095] When the second region has a pattern formed by a regular arrangement of openings, the proportion of the openings in the second region may be, for example, 1% to 30%, particularly 3% to 20%, and more particularly 5% to 10%. If the proportion of the openings in one second region is too small, the effects of improving the design and wiping properties provided by the openings may not be achieved. If the proportion of the openings in one region is too large, the strength of the nonwoven fabric may decrease, and when used as a wiper, wiped dirt may adhere to hands or tools through the openings, or the wiped dirt may easily detach from the openings.

[0096] When either the first region or the second region has no pattern, the other region may have a diagonal line pattern or a pattern formed by a regular arrangement of openings. In particular, when the other region has a diagonal line pattern, the difference in thickness between the diagonal line pattern and the non-patterned region becomes large, which tends to improve scraping performance when used as a wiper.

[0097] In the nonwoven fabric of this embodiment, the second intertwined portion may further include a third region. In a plan view, the direction in which each region extends continuously is the Y direction, and the direction perpendicular to the Y direction is the X direction. The third region may have a dimension of 9 mm or less in the X direction, particularly 7 mm or less, and more particularly 5 mm or less. The X direction dimension of the third region generally corresponds to the X direction dimension of the opening or recess formed in the third region. As described in the first embodiment, the third region is formed corresponding to the boundary between the weave structures of the support, where two different weave structures are repeatedly formed. Therefore, the third region may be formed as a narrow region, particularly as a linear region whose X direction dimension is approximately the dimension of one opening or recess.

[0098] The third region has at least one or both of a plurality of openings and recesses arranged linearly in the Y direction. The third region may have a mixture of openings and recesses, for example, a mixture of a plurality of openings arranged linearly and a plurality of recesses arranged linearly. Alternatively, when openings and recesses are mixed, they may be arranged linearly without any regularity. The recesses may be, for example, portions where the rearrangement of fibers during hydroentanglement treatment was insufficient to form openings. Alternatively, the third region may have no openings and only recesses, and recesses resulting from knuckles as well as floating weft yarns may be formed, with these recesses arranged regularly to form a pattern. Nonwoven fabrics using fiber webs that are less susceptible to rearrangement by water currents, such as nonwoven fabrics with a larger basis weight and laminated nonwoven fabrics, tend to form only recesses in the third region.

[0099] At least one of the shape, size, and spacing of the openings and / or recesses in the third region is different from those in the other regions, so that the third region has a different pattern from the first and second regions. This, combined with its smaller dimension in the X direction, gives the third region an appearance resembling a stitch or a cut line, making the boundary between the first and second regions more distinct. If either the first or second region has no pattern, the third region naturally has a different pattern from the unpatterned region in that it has either or both of openings and recesses.

[0100] The area M3 of the opening or recess formed in the third region (the area of ​​one opening or recess) is, for example, 0.3 mm 2 Over 4.0mm 2 It may be less than or equal to 0.4 mm, in particular 2 More than 3.5mm 2 Below, more particularly 0.5 mm 2 Over 3.0mm 2 The average diameter of one opening or recess may be, for example, 0.5 mm or more and 4.0 mm or less, particularly 0.7 mm or more and 3.5 mm or less, and more particularly 1 mm or more and 3 mm or less. In order to increase the average diameter or area of ​​the openings or recesses in the third region, it is necessary to increase the diameter of the warp threads of the striped pattern-forming support used during production. However, weaving using warp threads with a large diameter tends to be difficult, and it is difficult to increase the average diameter of the openings or recesses indefinitely. If the average diameter of the openings or recesses in the third region is too small, the pattern in the third region may be difficult to recognize as different from the patterns in the first and second regions.

[0101] When the basis weight of the nonwoven fabric is large or the like, in the third region, only recesses may be formed. In that case, depending on the type of the pattern formation support used in the production of the nonwoven fabric or the like, two types of recesses may be formed. In this case, the above average diameter or area shall be those of the recesses formed corresponding to the knuckles (parts where the warp threads float) of the support. The recesses formed corresponding to the knuckles (parts where the warp threads float) of the support are often formed in the nonwoven fabric as vertically long ones having a deeper depth of the recess and a longer dimension in the X direction.

[0102] When the average diameter of the openings or recesses formed in the first region is L1, the average diameter of the openings or recesses formed in the second region is L2, and the average diameter of the openings or recesses formed in the third region is L3, L3 may be larger than either L1 or L2. By L3 being the largest, the third region can be more emphasized at the boundary between the first region and the second region, and the design effect of the nonwoven fabric can be enhanced more.

[0103] The relationship among the area per one of the openings or recesses M1, M2, and M3 formed in each region is affected by the weave structure of the striped pattern formation support used in the production of the nonwoven fabric. For example, in the nonwoven fabric produced using the support as shown in FIG. 1, the relationship of M1≦M2<M3 may be satisfied, and further, the relationship of M3 / M2≧1.2, more particularly M3 / M2≧1.5, and even more particularly M3 / M2≧2.0 may be satisfied. This is because, like the support shown in FIG. 1, in the weave structure A, the number of floating warp threads is smaller compared to the number of floating weft threads, and it is more difficult to form openings or recesses in the first region. When M3 and M2 satisfy or do not satisfy the above relationship, when openings and / or recesses are formed in the first region, M3 and M1 may satisfy the relationship of M3 / M1≧1.2, more particularly M3 / M1≧1.3.

[0104] Note that there may be no openings or recesses formed in the first region and / or the second region, and M1 and / or M2 may be substantially zero. In this case, M3 / M2 cannot be determined. However, even when M1 and / or M2 are zero, since the third region and the first region are more clearly distinguished, it is assumed that the relationship M3 / M2 ≥ 1.2 is satisfied.

[0105] Also, for example, in the non-woven fabric produced using the support shown in FIG. 2, the relationship M2 < M1 < M3 may be satisfied, and further, the relationship M3 / M1 ≥ 1.2, more particularly M3 / M1 ≥ 1.3 may be satisfied. In the support shown in FIG. 2, since the number of floats of the weft yarns of the woven structure A is smaller compared to the support of FIG. 1, openings are relatively likely to be formed in the first region. Therefore, in order to distinguish the third region from the first region, it is possible to define the relationship between M3 and M1, and by satisfying M3 / M1 ≥ 1.2, the third region is more emphasized.

[0106] The distance between openings, between recesses, or between an opening and a recess formed in the third region may be, for example, 1 mm or more and 9 mm or less, particularly 2 mm or more and 8 mm or less, and more particularly 2.5 mm or more and 7 mm or less. Here, the distance between openings, between recesses, or between an opening and a recess is, as described in relation to the oblique line S1 that can be formed in the first region, the shortest of the line segments connecting the centers in all combinations of adjacent openings, an adjacent opening and a recess, and adjacent recesses. In the third region, when openings and recesses are mixed, it is preferable that the distances between openings, between recesses, and between an opening and a recess all satisfy the above range. Since the openings and / or recesses are linearly arranged in a row in the Y direction in the third region, the distance between openings, between recesses, or between an opening and a recess generally becomes the distance in the Y direction.

[0107] In the nonwoven fabric of this embodiment, the second entangled portion may further have a fourth region. The fourth region is formed at the boundary between one first region (or second region) and the second region (or first region) on the opposite side from the side where the third region is formed. That is, like the third region, the fourth region is formed corresponding to the boundary between the weave structures of the support where two different weave structures are repeatedly formed. A nonwoven fabric having a fourth region has four regions repeatedly formed in the X direction in the order of the first region, third region, second region, and fourth region. Note that the repetition of 1st → 3rd → 2nd → 4th in one direction becomes the repetition of 1st → 4th → 2nd → 3rd in the opposite direction.

[0108] The fourth region has a dimension in the X direction of 9 mm or less in a plan view, particularly 8 mm or less, more particularly 6 mm or less, and even more particularly 4 mm or less. The X direction dimension of the fourth region roughly corresponds to the X direction dimension of the opening or recess formed in the fourth region. Like the third region, the fourth region is formed corresponding to the boundary between the weaves of the support in which two different weaves are repeatedly formed. Therefore, it is formed as a narrow region, particularly a linear region whose X direction dimension is roughly the dimension of one opening or recess. The dimension of the fourth region is determined by the weave of the pattern-forming support and the thicknesses of the wefts a and b. For example, when using a support as shown in FIG. 5, the fourth region is formed by knuckles N2 and N3, which have two warp floats, and therefore its X direction dimension is smaller than that of the third region, which is formed by knuckle N1, which has three warp floats.

[0109] The fourth region has at least one or both of a plurality of openings and recesses arranged linearly in the Y direction. The fourth region may have a mixture of openings and recesses, for example, a mixture of a plurality of openings arranged linearly and a plurality of recesses arranged linearly. Alternatively, when openings and recesses are mixed, they may be arranged linearly without any regularity. The recesses may be, for example, portions where the rearrangement of fibers during hydroentanglement treatment was insufficient to form openings. Alternatively, the fourth region may have only recesses, with no openings, and may have not only recesses resulting from knuckles but also recesses resulting from floating weft yarns, arranged regularly to form a pattern. Nonwoven fabrics using a fiber web that is less susceptible to rearrangement by water currents, such as nonwoven fabrics with a larger basis weight and laminated nonwoven fabrics, tend to have only recesses formed in the fourth region.

[0110] At least one of the shape, size, and spacing of the openings and / or recesses in the fourth region is different from those in the first and second regions, giving the fourth region a different pattern from these regions. As a result, the fourth region, like the third region, has a smaller dimension in the X direction, giving it the appearance of stitches or cut lines, making the boundary between the first and second regions more distinct. If either the first or second region has no pattern, the fourth region naturally has a different pattern from the no-pattern region in that it has either or both openings and recesses. The fourth region may have the same pattern as the third region, or a different pattern.

[0111] The area of ​​the opening or recess formed in the fourth region (the area of ​​one opening or recess) is, for example, 0.5 mm 2 More than 3.5mm 2 It may be less than or equal to 0.7 mm, in particular 2 More than 3mm 2 Below, more particularly 1 mm 2 Over 2.5mm 2The following may be applicable. The average diameter of one opening or recess may be, for example, 0.5 mm or more and 5 mm or less, particularly 1 mm or more and 4 mm or less, and more particularly 2 mm or more and 3 mm or less. The reason for exemplifying the above as the range of the average diameter or area of the openings or recesses in the fourth region is as described above in relation to the average diameter and area of the openings or recesses in the third region.

[0112] When the basis weight of the non-woven fabric is large, etc., in the fourth region, only recesses may be formed, and in that case, depending on the type of the pattern-forming support used in the production of the non-woven fabric, etc., two types of recesses may be formed. In this case, the above average diameter or area shall be that of the recesses formed corresponding to the knuckles (parts where the warp threads are floating) of the support. The recesses formed corresponding to the knuckles (parts where the warp threads are floating) of the support are often formed in the non-woven fabric as vertically long ones having a deeper depth and a longer dimension in the X direction.

[0113] As described above, when the diameters of the openings or recesses formed in the first to third regions are L1 to L3 respectively, and the diameter of the openings or recesses formed in the fourth region is L4, L4 may be larger than either L1 or L2. The relationship between L3 and L4 is not particularly limited, and L3 = L4 may be applicable, or L3 > L4, or L3 < L4 may be applicable. Since L4 is larger than either L1 or L2, the fourth region is more emphasized at the boundary between the first region and the second region, and the design effect of the non-woven fabric can be enhanced more.

[0114] The relationship among M1, M2, M3, and M4 is affected by the weave structure of the pattern-forming support used in nonwoven fabric production. For example, in the nonwoven fabric produced using the support shown in FIG. 5, the relationships of M2 < M1 < M3 and M2 < M1 < M4 may be satisfied. Further, the relationships of M3 / M2 ≥ 1.2, particularly M3 / M2 ≥ 1.3, and / or M4 / M2 ≥ 1.2, particularly M4 / M2 ≥ 1.3 may be satisfied. Furthermore, M4 and M1 may satisfy a relationship such as M4 / M1 ≥ 1.2, particularly M4 / M1 ≥ 1.5, more particularly M4 / M1 ≥ 2, and even more particularly M4 / M1 ≥ 3. Additionally, M3 and M1 may satisfy a relationship such as M3 / M1 ≥ 1.2, particularly M3 / M1 ≥ 1.3, and more particularly M3 / M1 ≥ 1.5.

[0115] The distance between the openings, between the recesses, or between the opening and the recess formed in the fourth region may be, for example, 1 mm or more and 8 mm or less, particularly 2 mm or more and 6 mm or less, and more particularly 3 mm or more and 4 mm or less. Here, the meaning of the distance between the openings, between the recesses, or between the opening and the recess is as described above in relation to the first region.

[0116] As described above, in the nonwoven fabric of the present embodiment, the first region and the second region, and optionally further the third region or the third region and the fourth region, are arranged parallel to each other within the second intersection portion and exist in a pattern repeated in a certain direction to form a pattern. That is, the nonwoven fabric of the present embodiment forms a stripe pattern or a ladder pattern in the direction (X direction) orthogonal to the direction (Y direction) in which each region extends. The direction in which each region is repeatedly arranged coincides with the direction in which the first intersection portion and the second intersection portion extend. Therefore, the nonwoven fabric of the present embodiment has a stripe pattern in which the first intersection portion and the second intersection portion, which are belt-shaped portions extending in the X direction, are regularly arranged in the Y direction, and the second intersection portion forms another stripe pattern or a lattice pattern, presenting a unique appearance that is not a simple stripe pattern but a lattice or patchwork pattern.

[0117] The first region may have a dimension in the X direction of, for example, 2 mm to 200 mm, particularly 3 mm to 100 mm, more particularly 5 mm to 50 mm, even more particularly 7 mm to 30 mm, and even more particularly 10 mm to 25 mm. The second region may also have a dimension in the X direction of, for example, 2 mm to 200 mm, particularly 3 mm to 100 mm, more particularly 5 mm to 50 mm, even more particularly 7 mm to 30 mm, and even more particularly 10 mm to 25 mm. The X direction dimension of the first region (hereinafter referred to as "width" for convenience) and the width of the second region may be the same or different. Furthermore, a single nonwoven fabric may have multiple first regions of different widths and / or multiple second regions of different widths.

[0118] If the width of the first region is too small, the design effect of the striped or checkered pattern may not be fully achieved, and when the nonwoven fabric is used as a wiper, the wiping performance may be insufficient. The same applies if the width of the second region is too small. If the width of the first region is too large, the design effect may not be fully achieved, and the wiping performance may be insufficient. The same applies if the width of the second region is too large.

[0119] [Fibers that make up nonwoven fabric] The fibers constituting the nonwoven fabric of this embodiment are not particularly limited, and any fibers used in the manufacture of nonwoven fabrics may be used. synthetic fibers made of one or more thermoplastic resins selected from polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and copolymers thereof; polyamide resins such as nylon 6, nylon 66, and copolymers thereof; polyolefin resins such as polymethylpentene, polypropylene, and polyethylene (including high-density polyethylene, low-density polyethylene, and linear low-density polyethylene); acrylic resins, engineering plastics such as polycarbonate, polyacetal, polystyrene, and cyclic polyolefins, and elastomers thereof; natural fibers such as cotton, silk, wool, hemp, and pulp; Regenerated fibers (including those whose surfaces have been treated with a hydrophobizing agent) such as rayon and polynosic obtained by the viscose method, cupra obtained by the cuprammonium method, and cellulosic fibers (such as Lyocell and Tencel (registered trademark)) obtained by the solvent spinning method; Cellulosic fibers obtained by melt spinning, and Semi-synthetic fibers such as acetate fibers The fiber may be formed of one or more fibers selected from:

[0120] The synthetic fibers may be either monofilaments or bicomponent fibers, such as concentric or eccentric sheath-core bicomponent fibers, islands-in-the-sea bicomponent fibers, side-by-side bicomponent fibers, or splittable bicomponent fibers.

[0121] Synthetic fibers may also be those that melt or soften when heated or the like to exhibit adhesive properties. For example, synthetic fibers may be single fibers or conjugate fibers containing a resin with a relatively low melting point, such as polyethylene, as one component, with the low-melting-point resin component occupying at least a portion of the fiber surface. Such fibers include, for example, sheath-core conjugate fibers made of a combination of polyethylene / polypropylene or polyethylene / polyethylene terephthalate, with polyethylene as the sheath component, or splittable conjugate fibers made of a combination of these thermoplastic resins.

[0122] In the case of core-sheath type composite fibers, the volume ratio of the core component to the sheath component (core component:sheath component) is preferably 80:20 to 20:80, more preferably 70:30 to 30:70, and even more preferably 60:40 to 40:60.

[0123] In the case of splittable conjugate fibers, the volume ratio of the two components (first:second) is preferably 80:20 to 20:80, more preferably 70:30 to 30:70, and even more preferably 60:40 to 40:60. In the case of splittable conjugate fibers, the number of divisions (i.e., the number of sections in the conjugate fiber) may be, for example, 4 to 32, particularly 4 to 20, and more particularly 6 to 10.

[0124] When synthetic fibers capable of bonding fibers together are used, the synthetic fibers may account for, for example, 5% by mass or more, particularly 10% by mass or more, and more particularly 15% by mass or more, when the total mass of the nonwoven fabric is 100% by mass. The upper limit of the proportion of adhesive synthetic fibers is, for example, 35% by mass, particularly 30% by mass, and more particularly 25% by mass. If the proportion of adhesive synthetic fibers is too low, the effects of bonding fibers together (e.g., improving the mechanical strength of the nonwoven fabric, suppressing fuzzing, and maintaining the applied pattern) may not be fully achieved. If the proportion of adhesive synthetic fibers is too high, the texture of the nonwoven fabric becomes hard and the drapeability decreases, which may affect wiping performance when used as a wiper.

[0125] The nonwoven fabric of this embodiment may contain, for example, 30% by mass or more, particularly 50% by mass or more, and more particularly 80% by mass or more of cellulosic fibers. Examples of cellulosic fibers include natural fibers derived from plants such as cotton, linen, ramie, jute, hemp, and pulp; regenerated fibers such as rayon and polynosic obtained by the viscose process, cupra obtained by the cuprammonium process, and cellulosic fibers obtained by solvent spinning (such as Lenzing Lyocell® and Tencel®); cellulosic fibers obtained by melt spinning; and semi-synthetic fibers such as acetate fibers. Cellulosic fibers, particularly when produced by entanglement using a high-pressure fluid flow, tend to entangle with each other, resulting in a nonwoven fabric that maintains its entangled state well even after entanglement, facilitating the formation of clear patterns on the nonwoven fabric. Furthermore, good entanglement of the fibers reduces fuzzing of the nonwoven fabric.

[0126] The fiber fineness is not particularly limited and is selected depending on the intended use of the nonwoven fabric. The fiber fineness may be, for example, 0.3 dtex to 10 dtex, particularly 0.5 dtex to 5.0 dtex, more particularly 0.7 dtex to 4.0 dtex, even more particularly 1.0 dtex to 3.0 dtex, and even more particularly 1.3 dtex to 2.5 dtex. When the fibers constituting the nonwoven fabric are natural fibers such as cotton, it may be difficult to use fibers within a specific fineness range. In such cases, fibers of various finenesses may be included. If the fiber fineness is too small, the fibers may become entangled with the support or may clog the support when the nonwoven fabric is produced by entanglement using a high-pressure fluid flow. If the fiber fineness is too large, the pattern may become unclear.

[0127] The fiber length is not limited and is selected depending on the manufacturing conditions of the nonwoven fabric. The fiber length is, for example, 10 mm or more and 100 mm or less. If the fiber length is outside this range, it may be difficult to produce a fiber web using, for example, a carding machine. Furthermore, in a low-basis-weight nonwoven fabric, if the fiber length exceeds 100 mm, the number of fibers constituting the nonwoven fabric will be reduced, which may result in an unstable formation of the nonwoven fabric or in the failure to obtain the required strength. Furthermore, if the fiber length is too short, the strength of the nonwoven fabric may decrease, and if the fiber length is too long, the pattern may not be clear. The fiber length is more preferably 25 mm or more and 90 mm or less, even more preferably 32 mm or more and 70 mm or less, and particularly preferably 38 mm or more and 65 mm or less. Alternatively, if the nonwoven fabric is manufactured by a method including producing a fiber web by an air-laying method or a wet papermaking method, the fiber length may be, for example, 2 mm or more and 20 mm or less.

[0128] [Nonwoven fabric form] The nonwoven fabric may have a single-layer structure or a laminate structure. The nonwoven fabric may be formed from a web selected from carded webs such as parallel webs, cross webs, semi-random webs, and random webs, air-laid webs, wet-laid webs, meltblown webs, and spunbonded webs. When cellulosic fibers are used in whole or in part as constituent fibers, a web selected from carded webs, air-laid webs, and wet-laid webs may be produced. When a nonwoven fabric is produced using these fiber webs containing cellulosic fibers, particularly by entanglement treatment using a high-pressure fluid flow, the fibers are easily entangled with each other, and the entangled state is well maintained even after the entanglement treatment. This facilitates the formation of clear patterns on the nonwoven fabric, and the good entanglement of the fibers suppresses fuzzing of the nonwoven fabric.

[0129] Furthermore, by forming the nonwoven fabric into a laminated structure including an air-laid web, a wet-laid web, a melt-blown web, or a spunbonded web, the mechanical strength of the nonwoven fabric can be improved.

[0130] [Physical properties of nonwoven fabric] The physical properties of the nonwoven fabric of this embodiment will be described below by way of example. Note that the physical properties of the nonwoven fabric vary depending on the fibers constituting the nonwoven fabric, the basis weight of the nonwoven fabric, and the manufacturing conditions of the nonwoven fabric, and therefore the nonwoven fabric of this embodiment is not limited to those having the following physical properties.

[0131] The thickness (under a load of 294 Pa) of the nonwoven fabric of this embodiment may be, for example, 0.50 mm or more and 1.0 mm or less, particularly 0.55 mm or more and 0.90 mm or less, and more particularly 0.60 mm or more and 0.80 mm or less.

[0132] The basis weight of the nonwoven fabric of this embodiment is not particularly limited and may be appropriately selected depending on the application, etc. For example, when the nonwoven fabric of this embodiment is used as a wiper, the basis weight is 30 g / m 2 More than 80g / m 2 or less, in particular 35 g / m 2 ~75g / m 2 and more particularly 40 g / m 2 ~70g / m 2 Alternatively, when the nonwoven fabric of this embodiment is used as a sanitary product (for example, a surface material of an absorbent article), the basis weight may be 20 g / m 2 ~70g / m 2 and in particular 25 g / m 2 ~65g / m 2 and more particularly 30 g / m 2 ~60g / m 2 Although it depends on the type of fiber used and the configuration of the fiber web, the larger the basis weight, the more likely it is that openings will be formed in the third region or the third and fourth regions in the second entangled portion, and the more likely it is that recesses will be formed. If the basis weight is too large, the pattern will be formed only on one side, and the effect of the pattern will only be manifested on one side. If the basis weight is too small, the pattern will not be clearly formed, and the effect of the pattern will not be fully realized.

[0133] (Embodiment 3: Use of the nonwoven fabric of embodiment 2) As the third embodiment, a product using the nonwoven fabric of the second embodiment will be described. The nonwoven fabric of embodiment 2 may be used as a wiper, either alone or together with another nonwoven fabric or sheet. This nonwoven fabric is unlikely to wrinkle even when placed on a soiled object and rubbed against the object by reciprocating in the direction in which the first and second regions are repeatedly formed, and the unevenness and openings that form the pattern of the first and second regions of the second entangled part allow the soiling on the object to be effectively wiped away.

[0134] Here, the term "wiper" includes those for use on people and those for use on objects. The term "wiper for use on people" includes wipers for wiping dirt off human skin, as well as wipers for wiping dirt off teeth and wipers for wiping dirt off scalp and hair. The object wiper may be used to wipe floors, kitchens, toilets, bathtubs, furniture, vehicles, walls, screen doors, window panes, etc. The person and object wiper may be provided in a state in which it is impregnated with, for example, water or an aqueous solution containing a cleaning component in an amount of 100 parts by mass or more and 1000 parts by mass or less per 100 parts by mass of the nonwoven fabric.

[0135] Alternatively, the nonwoven fabric of this embodiment may be used in hygiene products such as sanitary napkins, disposable diapers for babies, and disposable diapers for adults. As described above, the nonwoven fabric of this embodiment has unique water absorption properties, and absorbed liquids are less likely to spread in the nonwoven fabric of this embodiment. Therefore, the nonwoven fabric of this embodiment may be used as a component, particularly a surface material, in hygiene products where it is necessary to suppress the spread of blood or excrement. Alternatively, the nonwoven fabric of this embodiment may be used in wet towels, face masks, hygiene masks, filters, patches, etc. [Example]

[0136] The present embodiment will be described below with reference to examples. The following fibers were prepared for use in the examples and comparative examples. Rayon (cellulosic fiber): Viscose rayon fiber with a fineness of 1.7 dtex and a fiber length of 40 mm (Corona CD (product name) manufactured by Daiwabo Rayon Co., Ltd.). PP / PE: Concentric core-sheath composite fiber (NBF(H) (product name) manufactured by Daiwa Boseki Co., Ltd.) with a core of polypropylene and a sheath of high-density polyethylene (melting point: approximately 133°C), a composite ratio (core:sheath) of 37:63 (volume ratio), a fineness of 1.7 dtex, and a fiber length of 51 mm.

[0137] The pattern-forming supports used in the pattern-forming and entangling treatment in the production of the nonwoven fabrics of the Examples and Comparative Examples are shown below. Pattern-forming support 1: A woven fabric was prepared as support 1, in which weave structure A was a 1 / 7 twill weave and weave structure B was a plain weave, with weave structure A and weave structure B arranged alternately in the MD. For support 1, polyester monofilaments with a rounded rectangular cross section and circumscribing the cross section with dimensions of long sides 0.88 mm x short sides 0.57 mm were used as warp yarns, polyester monofilaments with a diameter of 0.9 mm were used as weft yarns a, and polyester monofilaments with a diameter of 0.45 mm were used as weft yarns b. For support 1, the warp density was 30 threads / inch, the weft density was 25 threads / inch, the MD dimension of weave structure A was 15 mm, and the MD dimension of weave structure B was 8 mm. For support 1, the surface of weave structure A was located 1.5 mm higher than the surface of weave structure B. Pattern-forming support 2: A woven fabric was prepared as support 2, in which weave structure A was a 1 / 3 broken twill weave (broken twill + 4 warp threads in 1 weave), weave structure B was a plain weave, and weave structures A and B were arranged alternately in the MD. For support 2, polyester monofilaments with a rounded rectangular cross section and circumscribing the cross section, with the long side measuring 0.88 mm and the short side measuring 0.57 mm, were used as warp threads. Weft thread a was a polyester monofilament with a diameter of 0.9 mm, and weft thread b was a polyester monofilament with a diameter of 0.45 mm. For support 1, the warp density was 30 threads / inch, the weft density was 17 threads / inch, the MD dimension of weave structure A was 15 mm, and the MD dimension of weave structure B was 8 mm. For support 2, the surface of weave structure A was located 1.0 mm higher than the surface of weave structure B. Pattern-forming support 3: A woven fabric was prepared as support 3, in which weave structure A was a 2 / 2 twill weave and weave structure B was a plain weave, with weave structure A and weave structure B arranged alternately in the MD. For support 3, polyester monofilaments with a rounded rectangular cross section and circumscribing the cross section with dimensions of long sides 0.88 mm x short sides 0.57 mm were used as warp yarns, polyester monofilaments with a diameter of 0.9 mm were used as weft yarns a, and polyester monofilaments with a diameter of 0.45 mm were used as weft yarns b. For support 1, the warp density was 30 threads / inch, the weft density was 17 threads / inch, the MD dimension of weave structure A was 20 mm, and the MD dimension of weave structure B was 10 mm. For support 3, the surface of weave structure A was 0.8 mm higher than the surface of weave structure B.

[0138] Pattern-forming support 4: A woven fabric was prepared as support 4, in which weave structure A was a 1 / 7 twill weave and weave structure B was a plain weave, with weave structure A and weave structure B arranged alternately in the MD. For support 4, polyester monofilaments with a rounded rectangular cross section and circumscribing the cross section with dimensions of long sides 0.88 mm x short sides 0.57 mm were used as warp yarns, polyester monofilaments with a diameter of 0.9 mm were used as weft yarns a, and polyester monofilaments with a diameter of 0.45 mm were used as weft yarns b. For support 4, the warp density was 30 threads / inch, the weft density was 25 threads / inch, the MD dimension of weave structure A was 15 mm, and the MD dimension of weave structure B was 20 mm. For support 4, the surface of weave structure A was located 1.6 mm higher than the surface of weave structure B. Pattern-forming support 5: A woven fabric was prepared as support 5, in which weave structure A was a 2 / 2 twill weave and weave structure B was a plain weave, with weave structure A and weave structure B arranged alternately in the MD. For support 5, polyester monofilaments with a rounded rectangular cross section and circumscribing the cross section with dimensions of long sides 0.88 mm x short sides 0.57 mm were used as warp yarns, polyester monofilaments with a diameter of 0.9 mm were used as weft yarns a, and polyester monofilaments with a diameter of 0.45 mm were used as weft yarns b. For support 5, the warp density was 30 threads / inch, the weft density was 17 threads / inch, the MD dimension of weave structure A was 6 mm, and the MD dimension of weave structure B was 6 mm. For support 5, the surface of weave structure A was 0.6 mm higher than the surface of weave structure B. Pattern-forming support 6: A woven fabric was prepared as support 6, in which weave structure A was a 2 / 2 twill weave and weave structure B was a plain weave, with weave structure A and weave structure B arranged alternately in the MD. For support 6, polyester monofilaments with a rounded rectangular cross section and circumscribing the cross section with dimensions of long sides 0.88 mm x short sides 0.57 mm were used as warp yarns, polyester monofilaments with a diameter of 0.9 mm were used as weft yarns a, and polyester monofilaments with a diameter of 0.45 mm were used as weft yarns b. For support 6, the warp density was 30 threads / inch, the weft density was 17 threads / inch, the MD dimension of weave structure A was 10 mm, and the MD dimension of weave structure B was 10 mm. For support 6, the surface of weave structure A was 0.45 mm higher than the surface of weave structure B.

[0139] Example 1 A fiber web was produced by mixing 80% by mass of rayon and 20% by mass of PP / PE using a parallel carding machine. The basis weight of this fiber web was about 40 g / m 2 It was. [Overall confounding treatment] The above-mentioned fiber web was placed on a plain weave net with a warp diameter of 0.132 mm, a weft diameter of 0.132 mm, and a mesh count of 90. While the fiber web was traveling at a speed of 4 m / min, a columnar water stream at a water pressure of 1.0 MPa was sprayed onto the front surface of the fiber web, and then a columnar water stream at a water pressure of 1.5 MPa was sprayed onto the back surface of the fiber web. A nozzle with orifices with a hole diameter of 0.12 mm spaced 0.6 mm apart was used to spray the water stream. The distance between the surface of the fiber web and the orifices was 15 mm.

[0140] [Pattern formation interlacing process] The fiber web after the overall entanglement treatment was placed on a pattern-forming support 1, and while the fiber web was traveling at a speed of 4 m / min, a columnar water stream at a water pressure of 1.5 MPa was sprayed onto the back surface of the fiber web. In the pattern-forming entanglement treatment, a nozzle in which some of the orifices were blocked to form a group of orifices at predetermined intervals was used to form second entangled portions. Specifically, a nozzle in which orifices with a hole diameter of 0.12 mm were provided at 0.6 mm intervals were partially blocked so that first entangled portions with a width of 10 mm were formed every 20 mm was used. During the hydroentanglement treatment, the nozzle was not vibrated, and the distance between the nozzle and the web was 15 mm. The same nozzle as that used in the overall entanglement treatment was used to spray the water stream.

[0141] The pattern-forming entanglement process yielded a nonwoven fabric having a first entangled portion and a second entangled portion in which first to third regions were formed, as shown in Figure 3. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a diagonal line pattern portion as the first region and a pattern portion with staggered openings as the second region were alternately repeated in the MD direction (X direction) to form a striped pattern. In addition, a third region consisting of multiple openings formed along the Y direction was formed between the first and second regions.

[0142] [Heat treatment] The nonwoven fabric after the pattern-forming entanglement treatment was heated at 135°C for approximately 5 seconds using a hot air penetration type heat treatment machine to carry out a drying treatment, and at the same time, the fibers were thermally bonded together by the PP / PE sheath component to obtain the nonwoven fabric of Example 1. The dimensions of each intertwined portion and each region of the obtained nonwoven fabric, and the configuration of the openings or recesses formed in each region are shown in Table 1.

[0143] Example 2 The nonwoven fabric of Example 2 was obtained in the same manner as in Example 1, except that pattern-forming support 2 was used in the pattern-forming entanglement treatment. The pattern-forming entanglement treatment resulted in a nonwoven fabric having a first entangled portion and a second entangled portion in which first to third regions were formed, as shown in Figure 4. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a pattern portion in which openings were irregularly formed as the first region and a pattern portion in which openings were staggered as the second region were alternately repeated in the MD direction (X direction), forming a striped pattern. In addition, a third region consisting of multiple openings formed along the Y direction was formed between the first and second regions. The dimensions of each entangled portion and each region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 1.

[0144] Example 3 The nonwoven fabric of Example 3 was obtained in the same manner as in Example 1, except that pattern-forming support 3 was used in the pattern-forming entanglement treatment. The pattern-forming entanglement process yielded a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in Figure 6. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 1.

[0145] Example 4 The nonwoven fabric of Example 4 was obtained in the same manner as in Example 1, except that a pattern-forming support 4 was used in the pattern-forming entanglement treatment. The pattern-forming entanglement treatment resulted in a nonwoven fabric having a first entangled portion and a second entangled portion in which first to third regions were formed, as shown in Figure 11. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. In addition, a third region consisting of multiple openings formed along the Y direction was formed between the first and second regions. The dimensions of each entangled portion and each region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 1.

[0146] Example 5 The nonwoven fabric of Example 5 was obtained in the same manner as in Example 1, except that a pattern-forming support 5 was used in the pattern-forming entanglement treatment. The pattern-forming entanglement process yielded a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 12. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 1.

[0147] Example 6 The nonwoven fabric of Example 6 was obtained in the same manner as in Example 1, except that pattern-forming support 6 was used in the pattern-forming entanglement treatment. The pattern-forming entanglement process yielded a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 13. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 1.

[0148] Example 7 The nonwoven fabric of Example 6 was obtained using the same procedure as that used in the production of Example 1, except that a nozzle was used in which some of the multiple orifices were blocked so that first intertwined sections 6 mm wide were formed every 6 mm (i.e., so that second intertwined sections 6 mm wide and first intertwined sections 6 mm wide were formed in a striped pattern) and that a pattern forming support 6 was used. The pattern-forming entanglement process yielded a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 14. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 2.

[0149] Example 8 The nonwoven fabric of Example 6 was obtained using the same procedure as that used in the production of Example 1, except that a nozzle was used in which some of the multiple orifices were blocked so that 10 mm wide first intertwined sections were formed every 10 mm (i.e., 10 mm wide second intertwined sections and 10 mm wide first intertwined sections were formed in a striped pattern) in the pattern forming entanglement process, and a pattern forming support 6 was used. The pattern-forming entanglement process yielded a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 15. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 2.

[0150] Example 9 The nonwoven fabric of Example 6 was obtained using the same procedure as that used in the production of Example 1, except that a nozzle was used in which some of the multiple orifices were blocked so that 20 mm wide first intertwined sections were formed every 10 mm (i.e., 10 mm wide second intertwined sections and 20 mm wide first intertwined sections were formed in a striped pattern) in the pattern forming entanglement process, and a pattern forming support 6 was used. The pattern-forming entanglement process yielded a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 16. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 2.

[0151] Example 10 The nonwoven fabric of Example 6 was obtained using the same procedures as those used in the production of Example 1, except that in the pattern-forming entanglement process, (i) a nozzle was used in which some of the multiple orifices were blocked to form a group of orifices at predetermined intervals so that 10 mm-wide first entangled sections were formed every 10 mm (i.e., 10 mm-wide second entangled sections and 10 mm-wide first entangled sections were formed in a striped pattern), (ii) the nozzle was vibrated in the transverse direction of the web at an amplitude of 80 mm and a vibration speed of 4 m / min, and (iii) pattern-forming support 6 was used. The pattern-forming entanglement process resulted in a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 17. The first and second entangled portions were meandering. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 2.

[0152] Example 11 The nonwoven fabric of Example 6 was obtained using the same procedure as that used in the production of Example 1, except that in the pattern-forming entanglement treatment, a nozzle in which some of the multiple orifices were blocked to form a group of orifices spaced at predetermined intervals was vibrated in the lateral direction of the web at an amplitude of 80 mm and a vibration speed of 4 m / min, and that a pattern-forming support 6 was used. The pattern-forming entanglement process resulted in a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 18. The first and second entangled portions were meandering. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 2.

[0153] Example 12 The nonwoven fabric of Example 6 was obtained using the same procedures as those used in the production of Example 1, except that in the pattern-forming entanglement treatment, a nozzle in which some of the multiple orifices were blocked to form a group of orifices spaced at predetermined intervals was vibrated in the transverse direction of the web at an amplitude of 80 mm and a vibration speed of 4 m / min, and that pattern-forming support 2 was used during the pattern-forming entanglement treatment. The pattern-forming entanglement process resulted in a nonwoven fabric having a first entangled portion and a second entangled portion in which first through fourth regions were formed, as shown in FIG. 18. The first and second entangled portions were meandering. In the second entangled portion, each region extended along the CD direction (i.e., the CD direction was the Y direction), and a first region, which was a diagonal line pattern portion, and a second region, which was a pattern portion with staggered openings, were alternately repeated in the MD direction (X direction), forming a striped pattern. A third region and a fourth region were formed at the boundary between the first and second regions. In the first region, diagonal lines S1 with openings and diagonal lines S2 without openings were alternately formed. The dimensions of each entangled portion and region of the resulting nonwoven fabric, as well as the configuration of the openings or recesses formed in each region, are shown in Table 2.

[0154] (Comparative Example 1) A nonwoven fabric of Comparative Example 1 was obtained in the same manner as in Example 1, except that the pattern-forming entanglement treatment was not carried out. This nonwoven fabric had no pattern throughout its entirety.

[0155] (Comparative Example 2) In the pattern-forming entanglement treatment, a fiber web was placed on a support having the following configuration, and while the fiber web was traveling at a speed of 4 m / min, a columnar water stream at a water pressure of 1.5 MPa was sprayed onto the fiber web using the nozzle used in the overall entanglement treatment in Example 1 to obtain a nonwoven fabric. The obtained nonwoven fabric had a grid pattern in which unpatterned entangled portions each approximately 10 mm wide were arranged vertically and horizontally, and the areas between the grids had a herringbone pattern. In the areas between the grids (approximately square areas), only one type of pattern was formed, and two or more areas with different patterns were not formed. The support used consisted of a 2 / 1 herringbone weave fabric with a warp thread of 0.66 mm diameter polyester monofilament and a weft thread of 0.89 mm diameter polyester monofilament, with a warp thread density of 41 threads / inch and a weft thread density of 15 threads / inch. A polyethylene resin sheet (1 mm thick) with holes measuring 2 cm vertically and 2 cm horizontally, arranged in a grid pattern with 1 cm spacing between adjacent holes, was attached to the fabric.

[0156] [Table 1] [Table 2]

[0157] The average diameter and area of ​​the openings or recesses, and the distance between the openings and recesses in the above examples were measured by the following methods. [Average diameter of openings, etc.] The nonwoven fabric was attached to a black paper or sheet, and in this state, an image of the nonwoven fabric surface was captured using the scanning function of a copy machine (DocuCentre-VII C4473 (product name), manufactured by Fuji Xerox Co., Ltd.) The scanning conditions were set to color mode: full color, resolution: 600 dpi, and image quality: highest quality. Image analysis of the scanned images was performed using the image processing software "Image J." The black areas in the scanned images were considered to be openings, and their average diameters and areas were calculated.

[0158] [Average diameter of recesses, etc.] The depressions formed in the nonwoven fabric were filled in with black magic marker and attached to a black piece of paper or sheet, and in this state, a scanned image was captured in the same manner as in the method for measuring the average diameter, etc. of the openings described above, and the areas displayed in black in the scanned image were considered to be depressions, and their average diameter, area, etc. were determined. Note that if the nonwoven fabric has not only depressions but also openings, the black areas visible through the openings are binarized in the same way as the depressions, so that the average diameter, etc. of these can also be measured.

[0159] The wiping test was carried out on each of the nonwoven fabrics of Examples 1 to 3, 8, 11 and 12 according to the following procedure. The evaluation results are shown in Table 3.

[0160] <Wipe test> Approximately 1 g of miso paste was spread evenly over a 6 cm x 1.5 cm area in the center of a transparent acrylic plate (3 mm thick, product number KAC9143-1S, manufactured by Hikari Corporation) to simulate soiling. The combined mass of the acrylic plate and miso paste (m1) was then calculated in advance. The mass of the simulated soiling was calculated from the difference between the previously calculated mass of the acrylic plate (m0) and m1.

[0161] The simulated soil was applied to an acrylic plate. A 10 cm x 6 cm nonwoven fabric (100 parts nonwoven fabric impregnated with 300 parts distilled water) was attached to a plate-shaped jig (wiping area 6 cm x 6 cm). The jig was then moved once in a predetermined direction at a speed of 10 mm / s and a distance of 100 mm while applying a pressure of 81 Pa. The mass (m²) of the acrylic plate after wiping was calculated. The difference between m² and m² was taken as the mass of the wiped simulated soil. This mass was used to calculate the wiping efficiency (the ratio of the mass of the wiped simulated soil to the mass of the soil spread on the acrylic plate). The sample was wiped in both the MD and CD directions of the nonwoven fabric to examine the difference in wiping efficiency depending on the wiping direction. Three samples were prepared for each sample, and the average was calculated to evaluate the wiping performance of each sample.

[0162] [Table 3]

[0163] All of the nonwoven fabrics of the Examples had higher wiping rates in the MD direction than Comparative Example 1. This was thought to be due to the fact that all of the nonwoven fabrics of the Examples had bands with different patterns regularly arranged in the MD direction, and the fiber web used was a parallel web, with the main fiber orientation direction being the MD direction, making it difficult for stretching to occur in the MD direction. In other words, even when the nonwoven fabric was moved in the MD direction, it was less likely to twist, firmly contacted the dirt, and the stripes or patterns including the third region were thought to retain the dirt that contacted the nonwoven fabric at its openings, etc. The nonwoven fabrics of Examples 1 to 3 also had smaller differences in wiping rates due to differences in wiping direction than the nonwoven fabric of Comparative Example 1.

[0164] The nonwoven fabric of the Example also had a higher wiping rate in the CD direction than the nonwoven fabric of Comparative Example 2, which had a grid pattern. This is thought to be because the presence of three or more regions with different patterns, i.e., regions with different fiber entanglement states, improved the dirt removal efficiency.

[0165] This embodiment includes the following aspects. (Aspect 1) A nonwoven fabric in which the first entangled portions and the second entangled portions are arranged in a striped pattern, the second entangled portion includes at least a first region and a second region, When a direction in which the first intertwined portions and the second intertwined portions continuously extend is defined as an X direction and a direction perpendicular to the X direction is defined as a Y direction in a plan view, the first regions and the second regions are repeatedly and alternately arranged in the X direction, the first intertwined portion, the first region, and the second region have patterns different from each other; Nonwoven fabric. (Aspect 2) The nonwoven fabric of embodiment 1, wherein the first entangled portions have no pattern, and the first and second regions have a pattern formed by high-density regions and low-density regions. (Aspect 3) The nonwoven fabric of embodiment 1 or 2, wherein the first entangled portions and the second entangled portions both extend linearly in plan view. (Aspect 4) The nonwoven fabric of embodiment 1 or 2, wherein the first entangled portions and the second entangled portions are both meandering in plan view. (Aspect 5) A nonwoven fabric according to any one of aspects 1 to 4, wherein the dimension of the first entangled parts in the Y direction is 2 mm or more and 200 mm or less. (Aspect 6) A nonwoven fabric according to any one of aspects 1 to 5, wherein the dimension of the second entangled portions in the Y direction is 2 mm or more and 200 mm or less. (Aspect 7) the second entangled portion further includes a third region, In the third region, at least one of a plurality of openings and a plurality of recesses arranged linearly in a line in the Y direction is formed, In a plan view, the third region has a dimension of 9 mm or less in the X direction, In a plan view, the first to third regions are repeatedly formed in the order of the first region, the third region, and the second region in the X direction; The first area, the second area, and the third area have different patterns. The nonwoven fabric of any one of Aspects 1 to 6. (Aspect 8) an area M3 of each of the openings or recesses formed in the third region is larger than both an area M1 of each of the openings or recesses formed in the first region and an area M2 of each of the openings or recesses formed in the second region; The nonwoven fabric of embodiment 7. (Aspect 9) the second entangled portion further includes a fourth region, In the fourth region, at least one of a plurality of openings and a plurality of recesses arranged linearly in a line in the Y direction is formed, In a plan view, the fourth region has a dimension of 9 mm or less in the X direction, In a plan view, the first to fourth regions are repeatedly formed in the order of the first region, the third region, the second region, and the fourth region in the X direction; The fourth region has a pattern different from the first region and the second region. The nonwoven fabric of any one of Aspects 1 to 8. (Aspect 10) The nonwoven fabric of embodiment 9, wherein the area M4 of each of the openings or recesses formed in the fourth region is greater than both the area M1 of each of the openings or recesses formed in the first region and the area M2 of each of the openings or recesses formed in the second region. (Aspect 11) Producing a fibrous web; placing the fibrous web on a support and subjecting the fibrous web to an entanglement treatment using a high-pressure fluid stream; A method for producing a nonwoven fabric comprising: The support has at least two types of weaves A and B, In the support, the weave structure A and the weave structure B are belt-shaped portions extending along the direction in which the weft yarns extend, and the weave structure A and the weave structure B are regularly and repeatedly formed along the direction in which the warp yarns extend, The entanglement treatment of the fiber web placed on the support with a high-pressure fluid stream is carried out by spraying the high-pressure fluid stream onto the fiber web along the extending direction of the weft yarns of the support so that portions onto which the high-pressure fluid stream is sprayed from two or more continuous orifices of a nozzle and portions onto which the high-pressure fluid stream is not sprayed alternate with each other. Method for manufacturing nonwoven fabric. (Aspect 12) The entanglement treatment using the high-pressure fluid flow is (i) by ejecting a high-pressure fluid stream from a nozzle containing one or more orifices spaced at regular intervals; or (ii) A member having a plurality of holes arranged in a row along a direction perpendicular to the direction of travel of the support, the member being impermeable to the high-pressure fluid except for the holes, is disposed between the fiber web and a nozzle, and a high-pressure fluid flow is sprayed from the nozzle. 12. A method for producing the nonwoven fabric of embodiment 11. (Aspect 13) In the support, The diameters of the weft yarn a constituting the weave structure A and the weft yarn b constituting the weave structure B are different, and the weft yarn a and the weft yarn b are adjacent to each other at the boundary between the weave structure A and the weave structure B, The surface of the weave A is located at a position higher than the surface of the weave B by 0.1 mm or more and 3.0 mm or less. 13. A method for producing a nonwoven fabric according to claim 11 or 12. (Aspect 14) 14. The method for producing a nonwoven fabric according to any one of aspects 11 to 13, wherein weave structure A is a weft twill weave having two or more floats of weft yarns and one float of warp yarn, and weave structure B is a plain weave structure. (Aspect 15) In the support, a knuckle N1 is formed, which is a portion where the warp yarn constituting the support floats on three or more continuous weft yarns including the weft yarn a and the weft yarn b. A method for producing a nonwoven fabric according to any one of aspects 11 to 14. (Aspect 16) A method for producing a nonwoven fabric according to any one of aspects 11 to 15, wherein, in the support, as viewed from the weave structure A, at the boundary with the weave structure B on the side opposite to the side where the knuckle N1 is formed, a knuckle N2 is formed in which the warp yarns constituting the support float above two or more continuous weft yarns including the weft yarn a and the weft yarn b, and a knuckle N3 is formed adjacent to either side of the knuckle N2 in which the warp yarns float above two or more continuous weft yarns. (Aspect 17) 17. The method for producing a nonwoven fabric according to claim 16, wherein the weave structure A is a twill weave having 2 to 16 floats of weft yarns and 2 to 16 floats of warp yarns, the weave structure B is a plain weave, and the diameter of the weft yarn a is larger than the diameter of the weft yarn b. [Industrial Applicability]

[0166] The nonwoven fabric of the present disclosure has a novel, unprecedented design. Therefore, the nonwoven fabric of the present disclosure is suitable for use in hygiene products such as wipers, sanitary napkins, disposable diapers for babies and children, disposable diapers for adults, hand towels, face masks, sanitary masks, filters, or patches. The nonwoven fabric of the present disclosure can be provided with two or more regions in the second entangled portions that are regularly and repeatedly arranged in the MD direction of the nonwoven fabric. In this case, even when the nonwoven fabric is moved back and forth in the MD direction on the surface of an object, it is less likely to twist, making the nonwoven fabric particularly suitable for use as a wiper.

Claims

1. A nonwoven fabric in which the first entangled portions and the second entangled portions are arranged in a striped pattern, The second entangled portion includes at least a first region and a second region, In a plan view, when a direction in which the first intertwined portion and the second intertwined portion continuously extend is an X direction and a direction perpendicular to the X direction is a Y direction, the first region and the second region are repeatedly and alternately arranged in the X direction, the first intertwined portion, the first region, and the second region have different patterns from each other; Nonwoven fabric.

2. 2. The nonwoven fabric according to claim 1, wherein the first entangled portions have no pattern, and the first and second regions have a pattern formed of high density regions and low density regions.

3. The nonwoven fabric according to claim 1 or 2, wherein the first entangled portions and the second entangled portions both extend linearly in a plan view.

4. The nonwoven fabric according to claim 1 or 2, wherein the first entangled portions and the second entangled portions are both meandering in a plan view.

5. The nonwoven fabric according to any one of claims 1 to 4, wherein the dimension of the first entangled portion in the Y direction is 2 mm or more and 200 mm or less.

6. The nonwoven fabric according to any one of claims 1 to 5, wherein the dimension of the second entangled portion in the Y direction is 2 mm or more and 200 mm or less.

7. The second entangled portion further includes a third region, In the third region, at least one of a plurality of openings and a plurality of recesses arranged linearly in a line in the Y direction is formed, In a plan view, the third region has a dimension of 9 mm or less in the X direction, In a plan view, the first to third regions are repeatedly formed in the order of the first region, the third region, and the second region in the X direction; The first region, the second region, and the third region have different patterns. The nonwoven fabric according to any one of claims 1 to 6.

8. an area M3 of each of the openings or recesses formed in the third region is larger than both an area M1 of each of the openings or recesses formed in the first region and an area M2 of each of the openings or recesses formed in the second region; The nonwoven fabric of claim 7.

9. The second entangled portion further includes a fourth region, In the fourth region, at least one of a plurality of openings and a plurality of recesses arranged linearly in a line in the Y direction is formed, In a plan view, the fourth region has a dimension of 9 mm or less in the X direction, In a plan view, the first to fourth regions are repeatedly formed in the X direction in the order of the first region, the third region, the second region, and the fourth region, The fourth region has a pattern different from the first region and the second region. The nonwoven fabric according to claim 7 or 8.

10. an area M4 of each of the openings or recesses formed in the fourth region is larger than both an area M1 of each of the openings or recesses formed in the first region and an area M2 of each of the openings or recesses formed in the second region; The nonwoven fabric of claim 9.

11. Producing a fibrous web; placing the fibrous web on a support and subjecting the fibrous web to an entanglement treatment using a high-pressure fluid flow; A method for producing a nonwoven fabric comprising the steps of: The support has at least two types of weaves A and B, In the support, the weave structure A and the weave structure B are belt-shaped portions extending along a direction in which the weft yarns extend, and the weave structure A and the weave structure B are regularly and repeatedly formed along a direction in which the warp yarns extend, The entanglement treatment of the fiber web placed on the support with the high-pressure fluid flow is carried out by spraying the high-pressure fluid flow on the fiber web along the extending direction of the weft yarn of the support such that a portion where the high-pressure fluid flow is sprayed from two or more continuous orifices of a nozzle on the fiber web and a portion where the high-pressure fluid flow is not sprayed on the fiber web are alternately positioned. A method for manufacturing nonwoven fabric.

12. The entanglement treatment by the high pressure fluid flow is (i) by ejecting a high-pressure fluid stream from a nozzle having one or more orifices spaced apart at regular intervals; or (ii) A member having a plurality of holes arranged in a row along a direction perpendicular to the traveling direction of the support, and not allowing the high-pressure fluid to pass through other than the holes, is placed between the fiber web and a nozzle, and a high-pressure fluid flow is sprayed from the nozzle. A method for producing the nonwoven fabric according to claim 11.

13. In the support, The diameter of the weft a constituting the weave structure A is different from the diameter of the weft b constituting the weave structure B, and the weft a and the weft b are adjacent to each other at the boundary between the weave structure A and the weave structure B, The surface of the weave structure A is located at a position higher than the surface of the weave structure B by 0.1 mm to 3.0 mm. A method for producing the nonwoven fabric according to claim 11 or 12.

14. The method for producing a nonwoven fabric according to any one of claims 11 to 13, wherein the weave structure A is a weft twill weave structure in which the number of floating weft yarns is two or more and the number of floating warp yarns is one, and the weave structure B is a plain weave structure.

15. In the support, a knuckle N1 is formed, which is a portion where the warp yarn constituting the support floats on three or more continuous weft yarns including the weft yarn a and the weft yarn b. A method for producing the nonwoven fabric according to any one of claims 11 to 14.

16. The method for producing a nonwoven fabric according to any one of claims 11 to 15, wherein, in the support, as viewed from the weave structure A, at the boundary with the weave structure B on the side opposite to the side where the knuckle N1 is formed, a knuckle N2 is formed in which a warp yarn constituting the support floats on two or more continuous weft yarns including the weft yarn a and the weft yarn b, and a knuckle N3 is formed adjacent to either side of the knuckle N2, in which a warp yarn floats on two or more continuous weft yarns.

17. The method for producing a nonwoven fabric according to claim 16, wherein the weave structure A is a twill weave having a number of weft floats of 2 to 16 and a number of warp floats of 2 to 16, the weave structure B is a plain weave, and the diameter of the weft yarn a is larger than the diameter of the weft yarn b.

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