WO2017164195A1 - Patterned non-woven fabric and manufacturing method for same - Google Patents

Abstract

Provided is a patterned non-woven fabric that exhibits a more advantageous design effect and has better balance between longitudinal strength and lateral strength. A patterned non-woven fabric 100 has low-density regions 10, first high-density regions 12 and second high-density regions 14, wherein: island-shaped parts 20 are each formed by a plurality of the low-density regions gathered together; the second high-density regions 14 are each formed at least between the low-density regions in each island-shaped part; the first high-density regions are formed between the island-shaped parts; the fiber density of the first high-density regions is lower than the fiber density of the second high-density regions; the fiber density of the low-density regions is lower than the fiber density of the first high-density regions, or the low-density regions are open holes; the total surface area of the low-density regions is 0.1-12% of the surface area of the entire non-woven fabric; and the total surface area of the island-shaped parts is 1-45% of the surface area of the entire non-woven fabric.

Description

Nonwoven fabric with pattern and method for producing the same

The present invention relates to a patterned nonwoven fabric having a pattern formed by arranging a plurality of portions having different fiber densities and a method for producing the same.

Conventionally, various non-woven fabrics having a pattern and methods for producing the same have been proposed. For example, Patent Document 1 discloses a fiber layer between a support member composed of a plurality of fluid permeable portions and a fluid impermeable portion that continuously surrounds and surrounds the fluid permeable portion, and a molding member in which a large number of holes are arranged. And a pressure fluid is applied to rearrange the high-density portion and the low-density portion corresponding to the permeable portion and the non-permeable portion of the support member, respectively. A method for producing a nonwoven fabric, wherein the non-woven fabric is rearranged so as to have another low density portion corresponding to the hole of the molded member, and each high density portion is cross-linked with each other by substantially rows of fibers. It is disclosed.

In Patent Document 2, a part of the constituent fibers of the fiber web in which the constituent fibers are entangled are rearranged by hydroentanglement, and each has a regular pattern and a plurality of stripes spaced apart from each other. Discloses a non-woven fabric having a stripe pattern and a stripe width of 4 mm to 50 mm.

Japanese Patent Publication No.54-10666 JP 2009-287158 A

The present disclosure aims to provide a patterned nonwoven fabric that exhibits a design effect different from that of a conventional patterned nonwoven fabric and has a better strength balance in the machine direction and the transverse direction, and a method for manufacturing the patterned nonwoven fabric.

In one aspect, the present disclosure is a patterned nonwoven fabric having a low density region, a first high density region, and a second high density region,
A plurality of the low-density regions are assembled to form one island-shaped portion,
In the one island-shaped portion, the second high-density region is formed at least between the low-density region and the low-density region,
The first high-density region is formed between the island-shaped portion and the island-shaped portion;
The fiber density in the first high-density region is smaller than the fiber density in the second high-density region,
The fiber density in the low density region is smaller than the fiber density in the first high density region, or the low density region is an aperture.
The total area of the low-density regions is 0.1% to 12% with respect to the entire area of the patterned nonwoven fabric, and the total area of the island-shaped portions is relative to the entire area of the patterned nonwoven fabric. 1% to 45%,
A patterned nonwoven fabric is provided.

The patterned nonwoven fabric of the present disclosure is configured so that three regions (low density region, first high density region, and second high density region) having different fiber densities are aggregated to form an island-like portion. A pattern is formed by arranging the second high-density region between the low-density regions in the island-like portion and arranging the first high-density region as a base portion between the island-like portions. Such a pattern exhibits an unprecedented design effect. Moreover, since the part which comprises the pattern is an island-shaped part enclosed by the base part, the nonwoven fabric of this indication becomes a thing with the better strength balance of the vertical direction by the formation of a pattern, and a horizontal direction. Furthermore, in the nonwoven fabric of the present disclosure, the total area of the low density region is 0.1% to 12% with respect to the entire area of the nonwoven fabric, and the total area of the island-shaped portions is with respect to the entire area of the nonwoven fabric. When the content is 1% to 45%, a higher design effect is exhibited and good handleability is achieved.

It is a top view which shows typically the nonwoven fabric of this embodiment. It is a top view which expands and shows an island-shaped part. It is a photograph which shows the surface of an example of the nonwoven fabric of this embodiment. It is a photograph which shows the surface of an example of the nonwoven fabric of this embodiment. It is a photograph which shows the surface of an example of the nonwoven fabric of this embodiment. It is a photograph which shows the surface of an example of the nonwoven fabric of this embodiment. It is a photograph which shows the surface of an example of the nonwoven fabric of this embodiment. It is a photograph which shows the surface of an example of the nonwoven fabric of this embodiment. It is a photograph which shows the surface of an example of the nonwoven fabric of this embodiment. In manufacture of the nonwoven fabric of this embodiment, it is a side view which shows an example of arrangement | positioning of the nozzle at the time of forming a low density area | region and a 2nd high density area | region, an opening member, a web, and a pattern formation support body.

The nonwoven fabric of the present embodiment is a patterned nonwoven fabric having a low density region, a first high density region, and a second high density region,
A plurality of low density regions are gathered to form one island,
In one island-like portion, a second high-density region is formed at least between the low-density region and the low-density region,
The first high density region is formed between the island portion and the island portion,
The fiber density in the first high density region is smaller than the fiber density in the second high density region,
The fiber density in the low density region is smaller than the fiber density in the first high density region, or the low density region is an aperture.
It is a nonwoven fabric with a pattern. FIG. 1 is a plan view schematically showing an example of the nonwoven fabric.

In the nonwoven fabric 100 shown in FIG. 1, nine circular low-density regions 10 gather to form one island-shaped portion 20, and the first high-density region 12 is formed between the island-shaped portions 20. The low density regions 10 are arranged in a zigzag manner, that is, in the vertical and horizontal directions, so that the low density regions 10 in the next row are located between the two low density regions 10 in a row. A typical staggered pattern is formed. In a modification, the low density regions 10 may be arranged in a square. The low density regions 10 are independent from each other, and a second high density region 14 is formed between the low density regions 10. The island-like portions 20 as a whole have a substantially rhombus or circle and are arranged in a staggered manner. In other words, the nonwoven fabric 100 is formed by regularly forming island-shaped portions 20 composed of the low-density regions 10 and the second high-density regions 14 on the nonwoven fabric based on the first high-density regions 12. It is a nonwoven fabric that is formed.

The low density region 10 is a region having the lowest fiber density among the three regions, and may be a portion where the thickness does not change from the other regions (that is, the unevenness may not be formed) Or a recessed part may be sufficient, or an aperture part may be sufficient. As will be described later, the low density region 10 is implemented by, for example, arranging a web on a fabric made of a relatively thick monofilament with high pressure fluid (high pressure gas such as compressed air, high pressure liquid such as high pressure water), The fiber web located on the intersection (the highest part) of the fabric is formed by moving the fibers around and rearranging them by the action of a high-pressure fluid (hereinafter also simply referred to as movement). When forming the low density area | region 10 by such a method, the area per low density area | region 10 is mainly determined by the thickness of the thread | yarn which comprises a textile fabric. Or the low density area | region 10 may be formed of the molded object or spiral net which has at least one selected from a convex part, a recessed part, and an opening part.

When the low density region is a concave portion or an opening portion, a plurality of low density regions may be gathered to form a regular pattern in the island-shaped portion. A regular pattern means a pattern formed by arranging low-density areas according to a certain rule. The regular pattern may be, for example, at least one selected from the group consisting of a dot pattern, a herringbone pattern, a checkered pattern, a lattice pattern, a staggered pattern, an oblique stripe pattern, a wave pattern, and a zigzag pattern. When the low density region forms a regular pattern, the design of the nonwoven fabric can be improved. Moreover, functions, such as air permeability of a nonwoven fabric, liquid permeability, liquid retention property, and wiping property, can be improved because a low density area | region forms a regular pattern. As will be described later, the regular pattern can be formed by placing a web on a support on which at least one selected from a convex portion, a concave portion and an opening is regularly arranged, and applying a high-pressure fluid.

Each low density region 10 may have an area of, for example, 0.03 mm ² to 20 mm ² , in particular, an area of 0.1 mm ² to 10 mm ² , and more particularly 0.7 mm. It may have an area of ² to 5.0 mm ² . If the low density region 10 is too small, the low density region 10 may not be sufficiently recognized, and the design effect may not be sufficiently exhibited. When the low density region 10 is too large, deformation or breakage such as elongation, twisting, and tearing is likely to occur in the nonwoven fabric, and the handleability is lowered. On the other hand, if the low density region 10 is too large, it may be difficult to be recognized as the low density region, and the design effect may not be sufficiently exhibited.

Low-density regions 10 are small areas of the fiber density than at least the first high-density regions 12, for example, it may have a fiber density of ^{0g / cm 3 ~ 0.080g / cm} 3, in particular, 0 g / cm ³ ~ may have a fiber density of 0.070 g / cm ^3, more particularly, may have a fiber density of ^{0g / cm 3 ~ 0.05g / cm} 3. That the fiber density is zero means that the low density region 10 is an aperture. When the fiber density of the low density region 10 is large and the difference from that of the first high density region 12 is small, the pattern becomes difficult to recognize and the sufficient design effect may not be exhibited.

The low density region has a total area (that is, the total area of all the low density regions in the nonwoven fabric) of, for example, 0.1% to 12%, particularly 0.5% to 10% of the total area of the nonwoven fabric, More particularly, it may be formed so as to occupy 1.0% to 9%, and more particularly 1.5% to 8%. When the ratio (area ratio) occupied by the low density region is within this range, the strength improvement by the second high density region formed between the low density regions is superior to the strength reduction caused by the formation of the low density region. Thus, the strength of the nonwoven fabric (especially, the stress at 10% elongation) can be effectively increased as compared with the case where the island-shaped portions (the low density region and the second high density region) are not formed. When the ratio of the total area of the low density region becomes too large, the strength of the nonwoven fabric may be lowered, and the nonwoven fabric is likely to be deformed or broken such as elongation, twisting, and tearing.

In one island-shaped part 20 or in one nonwoven fabric 100, the fiber density, shape and area of each low-density region 10 do not necessarily have to be the same. For example, in one island-shaped portion 20, one low density region 10 may be a hole portion, and another low density region 10 may be a region that is not a hole portion.

The pitch between the low density regions 10 is not particularly limited, and may be, for example, 0.1 mm to 50 mm, particularly 0.5 mm to 30 mm, and more particularly 1 mm to 10 mm in at least one direction. It may be. Here, the pitch corresponds to the distance between the centers of gravity of adjacent low-density regions 10 in one island-shaped portion 20. Further, the interval between the low density regions 10 may be, for example, 0.1 mm to 50 mm, particularly 0.5 mm to 30 mm, and more particularly 1.0 mm to 10 mm in at least one direction. It's okay. Here, the interval is an arbitrary point on the outer periphery (contour) of the low-density region 10 and the outer periphery (contour) of another low-density region 10 adjacent to the low-density region 10 in one island-shaped portion 20. ) The shortest line segment among the line segments connecting any one of the above points.

In one island-shaped part 20 or one nonwoven fabric 100, the pitch and interval between the low density regions 10 may not be constant. For example, when the low-density regions 10 are arranged in a staggered manner as shown in FIG. 2 in which the non-woven island-like portion 20 shown in FIG. 1 is enlarged, the pitch (a1, a2 in the figure) and the interval (B1 and b2 in the figure) have different values depending on the direction, but in the present embodiment, it is preferable that at least the shortest pitch and the shortest interval are within the above ranges, respectively. Is more preferably within the above range.

The second high-density region 14 is a region that is formed at least between the low-density region 10 and the low-density region 10 and has a higher fiber density than the first high-density region 12. As described above, the second high-density region 14 is a region where the moved fibers are densely gathered when the fibers are moved by the action of the high-pressure fluid to form the low-density region 10. Since the fibers move around the low density region 10, for example, in FIG. 1, the second high density region 14 is also formed outside the low density region 10 </ b> A located outside (for example, in a portion surrounded by a dotted line in the drawing). Generally formed. However, the boundary between the second high-density region 14 and the first high-density region 12 may not be clear. It should be noted that the dotted lines shown in FIG. 1 and other drawings are for conceptualizing the island-shaped portion 20 and do not clearly indicate the range of the second high-density region 14.

The second high-density region 14 has a higher fiber density than the first high-density region 12, and may have a fiber density of, for example, 0.01 g / cm ³ to 0.30 g / cm ^3. may have a fiber density of ^{.03g / cm 3 ~ 0.20g / cm} 3, more particularly, it may have a fiber density of ^{0.05g / cm 3 ~ 0.15g / cm} 3. The second high-density region 14 may have a thickness of, for example, 0.05 mm to 5.0 mm, particularly 0.10 mm to 3.0 mm, more particularly 0.2 mm to 2.0 mm. When the second high-density region 14 is formed by gathering fibers that have moved when the low-density region 10 is formed, the fibers are densely gathered in the region, and the thickness thereof is the first high-density region 12. The fiber density is generally higher than that of the fiber. Here, the fiber density is determined from the thickness measured without applying a load of the nonwoven fabric and the basis weight of the nonwoven fabric. The thickness in a state where no load is applied to the nonwoven fabric can be determined by, for example, observing an electron micrograph.

The island-shaped portion 20 is a portion in which a plurality of low-density regions 10 are gathered, and is a portion where the second high-density regions 12 are formed at least between the low-density regions 10. The island-like portion 20 has a partially mesh-like appearance, particularly when the low-density region 10 is an aperture portion.

For example, the island-shaped portion 20 is provided with an opening corresponding to the island-shaped portion 20, and a member that does not allow high-pressure fluid to pass between the openings, that is, an opening member (for example, a metal plate) is prepared. You may form by making the high pressure fluid which passed the opening part act on the web arrange | positioned on the support body for forming. That is, the island-like portion 20 having the low-density region 10 and the second high-density region 14 can be formed by limiting the region where the high-pressure fluid acts to only the portion corresponding to the island-like portion 20. It becomes possible. Therefore, the area and shape of the island-shaped portion 20 are determined by the area and shape of the opening. However, the area and shape of the island-shaped portion 20 are not exactly the same as those of the opening. The reason is that the island 20 is formed by the action of the high-pressure fluid that has passed through the opening, and the area where the high-pressure fluid actually acts depends on the spread of the high-pressure fluid and the number of nozzle orifices that overlap the opening. Change. The pressure of the high pressure fluid, the diameter of the orifice, the fineness, the softness and the length of the fibers (which affect the degree of fiber movement), and the web weight and density are also the area of the island 20 And affect the shape. These are also factors that the area and shape of the island-like portion 20 are not the same as those of the opening.

In the case where the island-shaped portion 20 is formed by confounding treatment using a high-pressure fluid (particularly, high-pressure water), the island-shaped portion 20 is a portion that is more affected by the action of the high-pressure fluid than the first high-density region 12. Are closely entangled and have a higher fiber density than the first high-density region 12. In addition, in the island-shaped portion 20, as described above, a region where fibers move and gather when forming the low-density region 10 is also formed, so that at least the low-density region 10 has a higher fiber density, A second high density region 14 is formed.

The shape of the island-shaped portion 20 is not particularly limited, and is circular, elliptical, cloud-shaped, polygons having three or more sides (including regular polygons), star-shaped, flowers, clover-shaped, heart-shaped, symbols, characters, etc. Any shape formed by straight lines or curves may be used. The polygon having three or more sides is, for example, a triangle, a rhombus, a trapezoid, a parallelogram, a rectangle (including a square), a regular pentagon, or the like. The island-shaped part 20 of a different shape and / or dimension may be formed in one nonwoven fabric.

In one non-woven fabric, the island portions 20 may be regularly arranged in the same size, and may be arranged in a staggered arrangement or a square arrangement, for example. Alternatively, the island-shaped portion 20 may be a collection of a plurality of island-shaped portions having different shapes and / or areas to form one symbol (motif), and the symbols may be arranged in a staggered arrangement or a square arrangement. . For example, in the non-woven fabric shown in FIGS. 3 to 5, the island portions 20 having the same size and shape are arranged in a staggered arrangement or a square arrangement. In the nonwoven fabric shown in FIG. 6, rows in which the substantially rectangular island portions 20 are arranged at equal intervals at an angle in the vertical direction are arranged so as to have a mirror image relationship with adjacent rows in the horizontal direction. Yes.

In the nonwoven fabric shown in FIG. 7, eight small circular island portions 20b are arranged around one large diameter circular island portion 20a to form one symbol, and the symbols are arranged in a staggered manner. ing. In the nonwoven fabric shown in FIG. 8, two large and small heart-shaped islands 20c and 20d form one symbol, and the symbols are arranged in a square arrangement. In the nonwoven fabric shown in FIG. 9, island portions 20 having the same dimensions and the same shape are arranged at equal intervals in the diagonal direction (two directions) to form a diamond pattern.
The arrangement of the island-shaped portions shown in the figure is only an example, and the arrangement of the island-shaped portions is not limited to these. For example, the island-shaped portions may be arranged irregularly, and an aggregate of a plurality of island-shaped portions may form one pattern (for example, flowers, animals, symbols, characters, etc.).

Size per one island 20 is not particularly limited, for example, the area may be a 1.0mm ² ~ 18000mm ^2, may in particular 3.0 mm ² ~ 5000 mm ^2, more especially 5 It may be from 0 mm ² to 2000 mm ² . As the area of the island-shaped portion 20 is larger, the number of low-density regions 10 included in the island-shaped portion 20 is larger. If the area of the island-shaped portion 20 is too small, the opening provided in the opening member is also small, and a high-pressure fluid having a sufficient energy amount does not pass through the opening, so that the low-density region 10 and the second high-density region 14 are formed. May be insufficient. If the area of the island-shaped portion 20 is too large, the pattern formed by the island-shaped portion 20 and the aggregate of the island-shaped portions 20 is not sufficiently recognized, and the design effect may not be obtained. In particular, when the nonwoven fabric is cut and used according to its use, depending on the size after cutting, the number of islands 20 or aggregates of islands 20 included in the cut region is reduced. The pattern formed by the shape portion 20 cannot be fully recognized. If the boundary of the island-shaped portion 20 is not clear, the area of the island-shaped portion 20 is a circle that can include all the low-density regions in the island-shaped portion 20, and is approximated by the area of the circle with the smallest diameter. It's okay.

The pitch between the island portions 20 is not particularly limited, and may be, for example, 5 mm to 100 mm, particularly 7 mm to 80 mm, and more particularly 10 mm to 50 mm in at least one direction. Here, the pitch corresponds to the distance between the centers of gravity of the adjacent island portions 20.
Further, the distance between the island-shaped portions 20 may be, for example, 1 mm to 100 mm, particularly 2 mm to 80 mm, and more particularly 5 mm to 50 mm in at least one direction. Here, the interval is a line connecting an arbitrary point on the outer periphery (contour) of the island-shaped portion 20 and an arbitrary point on the outer periphery (contour) of another island-shaped portion 20 adjacent to the island-shaped portion 20. This refers to the shortest line segment. The pitch and interval of the island portions 20 may be different values depending on the direction as in the case of the low density region 10. In this case, it is preferable that at least the shortest pitch and the shortest interval are within the above ranges. More preferably, the pitches and intervals in all directions are within the above range. When each of the island-shaped portions 20 shows a symbol, if the pitch and interval of 20 are too small, the boundary between adjacent island-like portions is not clear, and the symbol indicated by the island-shaped portion 20 is recognized. It may be difficult to be done.

Alternatively, the island-shaped portion 20 has a total area (that is, the total area of all the island-shaped portions in the nonwoven fabric) of, for example, 1% to 45%, particularly 3% to 40%, more particularly the total area of the nonwoven fabric. It may be formed so as to occupy 5% to 35%, and more particularly 7% to 30%. If the proportion of the island-shaped portion 20 (area ratio) is too small, the desired design effect may not be obtained. If it is too large, the island-shaped portion 20 has an island-like area as in the case where the area is too large. The pattern formed by the aggregate of the portion 20 and the island-shaped portion 20 may not be sufficiently recognized. Moreover, when the total ratio of the area of the island-shaped part 20 which occupies for a nonwoven fabric is too large, the space | interval between the island-shaped parts 20 may become small, and the pattern which the island-shaped part 20 shows may become difficult to be recognized.

In addition, in the above, the island-shaped part 20 is demonstrated as what forms the independent area | region in the nonwoven fabric. Whether or not “the island portions form an independent region” is determined by the following method.
i) One island-like portion (referred to as “island-like portion A” for convenience) and an island-like portion located next to the island-like portion A and closest to the island-like portion A (for convenience (Referred to as “island B”).
ii) Among the low-density regions included in the island-shaped portion A, the one closest to the low-density region included in the island-shaped portion B is defined as the low-density region A, and the low-density region included in the island-shaped portion B Among them, the one closest to the low density region included in the island-shaped portion A is defined as the low density region B.
iii) The distance between the low density region A and the low density region B is measured. If the interval between the low density region A and the low density region B is larger than the largest of the interval between the low density regions included in the island portion A and the interval between the low density regions included in the island portion B, the island shape It can be said that the parts are formed independently.
The interval between the low density region A and the low density region B is at least twice as large as the interval between the low density region included in the island-shaped portion A and the interval between the low density regions included in the island-shaped portion B. Is preferably 3 times or more, more preferably 5 times or more.

The first high-density region 12 is a portion that can be said to be a base of a nonwoven fabric, and is a portion that is located between the island-shaped portion 20 and the island-shaped portion 20. The first high-density region 12 has a high-pressure fluid having energy necessary for forming the low-density region and the second high-density region when the confounding process using the high-pressure fluid is performed using the member having the opening. There is no part. The first high-density region 12 is a region integrated in advance before the entanglement process with the high-pressure fluid using the member having the opening. For example, the fibers are entangled in advance by the entanglement process with the high-pressure fluid. A portion where the fibers are bonded together, or a portion where the fibers are entangled and bonded together.

The fiber density of the first high-density region 12 is not particularly limited as long as it is larger than that of the low-density region 10 and smaller than that of the second high-density region 14, and is, for example, 0.01 g / cm ³ to 0. It may have a fiber density of 20 g / cm ³ , in particular it may have a fiber density of 0.03 g / cm ³ to 0.15 g / cm ³ , more particularly 0.05 g / cm ³ to 0. It may have a fiber density of 13 g / cm ³ . Since the first high-density region 12 is a portion serving as a base for forming the island-shaped portion 20 (the low-density region 10 and the second high-density region 14), the fiber density is too small or too large. However, it may be difficult to form the island-shaped portion 20 satisfactorily.

The first high density region may have a thickness of, for example, 0.05 mm to 3.0 mm, particularly 0.1 mm to 2.5 mm, more particularly 0.2 mm to 1.8 mm.

When the low density region 10 is an aperture, the fiber density of the first high density region 12 and the second high density region 14 has a ratio of 1 / 1.03 or less (first / second). It may have a ratio of 1 / 1.05 or less (first / second). When the low density region 10 is not an aperture, the fiber density ratio between the low density region 10 and the first high density region 12 may be, for example, 1 / 1.03 or less (low density / first). /1.05 or less (low density / first). When the density difference between the low density region 10 and the first high density region 12 and / or the density difference between the first high density region 12 and the second high density region 14 is small, the pattern formed by the island-shaped portions 20 It may become indistinct and the design effect may not be exhibited sufficiently.

In the nonwoven fabric of this embodiment, it is preferable that the fibers are entangled with each other. That is, it is preferable that the fibers are entangled in any of the low-density region (except when formed as an aperture), the first high-density region, and the second high-density region. According to the entanglement between the fibers, the low-density region, the first high-density region, and the second high-density region are clearly and easily formed. The fibers are preferably entangled by the action of the high-pressure fluid, and more preferably entangled by the action of the high-pressure liquid (particularly high-pressure water). A nonwoven fabric in which fibers are entangled with a high-pressure liquid is excellent in touch. Further, since the entanglement treatment with the high-pressure liquid easily removes the excess fiber treatment agent adhering to the fibers, the nonwoven fabric in which the fibers are entangled with each other by the high-pressure liquid is preferably used in applications where the adhesion of the fiber treatment agent is not desirable. It is done.

The fiber which comprises the nonwoven fabric of this embodiment is not specifically limited, It selects according to the use etc. of a nonwoven fabric. The nonwoven fabric of this embodiment is, for example,
Polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and copolymers thereof, polyamide resins such as nylon 6, nylon 66, and copolymers thereof, polymethylpentene, polypropylene, and polyethylene (high Synthetic fibers composed of one or more thermoplastic resins selected from polyolefin resins such as density polyethylene, low density polyethylene, and linear low density polyethylene), and acrylic resins,
Natural fibers such as cotton, silk, wool, hemp, and pulp, as well as rayon and polynosic obtained by the viscose method, cupra obtained by the copper ammonia method, cellulosic fiber obtained by the solvent spinning method (Lentzing Griyocell (registered trademark)) ) And Tencel (registered trademark)), and regenerated fibers (including those treated with a hydrophobizing agent) such as cellulose fibers obtained by melt spinning, and semi-synthetic fibers such as acetate fibers It may be formed of one or more fibers.

The synthetic fiber may be either a single fiber or a composite fiber. The conjugate fiber may be, for example, a concentric or eccentric core-sheath conjugate fiber, a sea-island conjugate fiber, a side-by-side conjugate fiber, or a split conjugate fiber.

The synthetic fiber may also exhibit adhesiveness by melting or softening by heating or the like. For example, the synthetic fiber may be a single fiber or a composite fiber containing a resin having a relatively low melting point such as polyethylene as one component, and the low melting point resin component occupying at least a part of the fiber surface. Such a fiber is, for example, a core / sheath composite fiber made of a combination of polyethylene / polypropylene and polyethylene / polyethylene terephthalate, in which polyethylene is a sheath component. When using a synthetic fiber capable of bonding fibers together, the synthetic fiber may be contained in the nonwoven fabric in an amount of, for example, 5% by mass or more, particularly 10% by mass or more, and more particularly 20% by mass or more. If the ratio of the adhesive synthetic fiber is too small, the effect (described later) by bonding the fibers may not be sufficiently obtained.

Alternatively, the synthetic fiber may be a latent crimpable fiber that develops three-dimensional crimps by heating or the like, or may be an actual crimpable fiber that exhibits three-dimensional crimps during fiber production.

The fineness of the fiber is not particularly limited as long as a desired pattern is formed, and is selected according to the use of the nonwoven fabric. The fineness of the fiber may be, for example, in the range of 0.1 dtex to 6.6 dtex, and may be in the range of 0.25 dtex to 3.3 dtex.

The fiber length of the fiber is not particularly limited as long as a desired pattern is formed, and is selected according to the manufacturing conditions of the nonwoven fabric. The fiber length of the fiber 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 card machine. In addition, in non-woven fabrics with a low basis weight, if the fiber length exceeds 100 mm, the number of fibers constituting the non-woven fabric will decrease, so the formation of the non-woven fabric may not be stable, or the required non-woven fabric strength will not be obtained. There is. The fiber length is more preferably 25 mm or more and 100 mm or less, still more preferably 32 mm or more and 70 mm or less, and particularly preferably 38 mm or more and 65 mm or less.

The nonwoven fabric of this embodiment contains, for example, 20% by mass or more, particularly 40% by mass or more, and more particularly 60% by mass or more of cellulose fibers. Here, as the cellulose fiber, natural fibers derived from plants such as cotton, linen, ramie, jute, hemp, and pulp; rayon and polynosic obtained by the viscose method, cupra obtained by the copper ammonia method, Cellulosic fibers obtained by the solvent spinning method (Lentzing Griyocell (registered trademark) and Tencel (registered trademark), etc.), regenerated fibers such as cellulose fiber obtained by the melt spinning method, and semisynthetic fibers such as acetate fibers It is done. Cellulose fibers, especially when producing nonwoven fabrics by entanglement treatment using high-pressure water flow, give the nonwoven fabric that the fibers are easily entangled and the entangled state is well maintained after the entanglement treatment. Clearly differentiated and allow a sharp pattern to be formed on the nonwoven.

The fibers contained in the nonwoven fabric may be synthetic fibers. Or a nonwoven fabric may consist of a combination of two or more types of fibers. For example, you may comprise the nonwoven fabric of this embodiment combining the cellulose fiber by which the hydrophobization process was carried out, and the cellulose fiber which has not been hydrophobized. When combining synthetic fibers, if the synthetic fiber is a core-sheath type composite fiber in which the combination of polyethylene / polyethylene terephthalate, polyethylene / polypropylene, low-melting point polyester / polyethylene terephthalate, etc. constitutes the sheath / core, these are treated by heat treatment, It is possible to obtain a nonwoven fabric in which the fibers are bonded to each other. Such a non-woven fabric has greater strength and higher dimensional stability than those in which the fibers are not bonded together.

The basis weight of the nonwoven fabric is not particularly limited as long as a desired pattern is formed, and is selected according to the use or the like. In order to obtain a nonwoven fabric in which each region has a fiber density and thickness in the above ranges, the basis weight of the nonwoven fabric may be, for example, 10 g / m ² to 300 g / m ² , particularly 15 g / m ² to 200 g / m ² . It may be more particularly 20 g / m ² to 100 g / m ² and even more particularly 25 g / m ² to 80 g / m ² . If the basis weight of the nonwoven fabric is too small, it may be difficult to form three regions having different fiber densities, and if too large, it may be difficult to form a particularly low density region.
When the nonwoven fabric is used as a surface material for absorbent articles such as napkins and panty liners, the basis weight of the nonwoven fabric may be, for example, 12 g / m ² to 60 g / m ² , particularly 18 g / m ² to 50 g / m ^2. m ² may be used. When used as a face mask, the basis weight of the nonwoven fabric may be 30 g / m ² to 250 g / m ² , particularly 40 g / m ² to 120 g / m ² , and when used as an interpersonal wiper, The basis weight of the nonwoven fabric may be 10 g / m ² to 200 g / m ² , particularly 15 g / m ² to 150 g / m ² , and when used as an objective wiper, the basis weight of the nonwoven fabric is 10 g / m ² to 200 g. / M ² , particularly 15 g / m ² to 150 g / m ² . Examples of the basis weight suitable for each application described here are, when the nonwoven fabric of this embodiment is used in a state of being laminated with another nonwoven fabric, the basis weight of the nonwoven fabric of this embodiment and the basis weight of the other nonwoven fabric. Is the total basis weight.

The nonwoven fabric may have a single layer structure or a laminated structure.
The nonwoven fabric may be formed from a web selected from a card web such as a parallel web, a cross web, a semi-random web and a random web, an air lay web, a wet papermaking web, and a spunbond web. When cellulose fibers are used as the constituent fibers, the fibrous webs that can be formed using the cellulose fibers are card webs, airlaid webs, and wet papermaking webs, and these fibrous webs comprising cellulose fibers have a clear pattern. It is suitable for producing a non-woven fabric formed in the present invention.

Next, the manufacturing method of the nonwoven fabric of this embodiment is demonstrated. The nonwoven fabric of the present embodiment is prepared by preparing a web selected from the webs listed above, performing entanglement treatment with a high-pressure fluid on the entire surface to form a first high-density region, and then partially entanglement with a high-pressure fluid You may process by the process and form an island-shaped part. The entanglement treatment with the high-pressure fluid for forming the island-shaped portion is performed by using a support having at least one selected from a convex portion, a concave portion and an opening portion for forming a low density region in the fiber web (hereinafter referred to as “pattern”). A member that has an opening and does not allow high-pressure fluid to pass through other than the opening (hereinafter simply referred to as “opening member”), and a nozzle and a web that inject high-pressure fluid And a method of injecting a high-pressure fluid through the opening.

By injecting the high-pressure fluid through the opening member, the high-pressure fluid having the energy necessary for forming the low-density region acts only on the portion of the web corresponding to the opening, and the fibers are more entangled. Proceeds to increase density. In addition, the high-pressure fluid ejected through the opening member acts on the web placed on the pattern formation support, thereby forming a low density region corresponding to the shape of the pattern formation support, Between the regions, the second high-density region is formed by the fibers moved to the periphery in forming the low-density region.

Examples of the high pressure fluid include high pressure gas such as compressed air and high pressure liquid such as high pressure water. The high-pressure liquid is preferably used in that a non-woven fabric excellent in tactile sensation can be obtained and an excess oil agent attached to the fiber can be removed. In the manufacture of nonwoven fabrics, water entanglement treatment using high-pressure water as a high-pressure fluid is often used. Also in this embodiment, hydroentanglement processing is preferably used from the viewpoint of ease of implementation and the like. In the following, a manufacturing method in the case of using high-pressure water (hereinafter, also simply referred to as “water flow”) as the high-pressure fluid will be described.

First, the formation of the first high-density region as a base is carried out by placing a web on a support and spraying a water flow. The water stream may be a columnar water stream. The first high density region is preferably formed so as to have a uniform texture with little roughness. Therefore, when forming the first high-density region, it is preferable to use a support having a relatively fine mesh, for example, a plain weave support of 80 mesh to 100 mesh. Hydroentanglement treatment is performed by applying a water flow of 1 MPa to 15 MPa to the front and back surfaces of the web from a nozzle in which orifices having a hole diameter of 0.05 mm to 0.5 mm are provided at intervals of 0.3 mm to 1.5 mm. You may carry out by injecting once. The water pressure is preferably 1 MPa to 10 MPa, more preferably 1 MPa to 7 MPa. The distance between the nozzle and the web may for example be 5 mm to 100 mm, in particular 10 mm to 50 mm.

Next, island-like portions (low density region and second high density region) are formed. When forming the island-shaped portion, as described above, the web after forming the first high-density region (hereinafter also referred to as “primary processed web”) is disposed on the pattern forming support, and the opening member Is placed between the nozzle and the web.

The pattern-forming support may have a convex portion. In this case, when a water stream hits the fiber located on the convex portion, the fiber moves to the periphery, the fibers are rearranged, and the convex portion is It enables low density regions to be formed at corresponding positions. Alternatively, the pattern forming support may have a concave portion, in which case the fibers around the concave portion move, move to the concave portion, and are rearranged in the concave portion, at a position corresponding to the concave portion. A second high density region is formed, and a low density region is formed around the recess. Depending on the shape of the recess, the second high-density region can be three-dimensional. Alternatively, the pattern forming support may have an opening, in which case the fibers around the opening move, move to the opening, and are rearranged at the opening to form the opening. A second high density region is formed at a corresponding position, and a low density region is formed around the opening. Depending on the shape of the opening and the like, the second high-density region can be three-dimensional. The pattern formation support body may have two or more selected from a convex part, a recessed part, and an opening part.

The pattern forming support may be a woven fabric, a punched plate member, or a spiral net made of natural resin, synthetic resin, or metal. Moreover, the pattern formation support body may have a regular pattern in which one or more selected from the convex portions, the concave portions, and the openings are regularly arranged. When such a pattern-forming support is used, a regular pattern can be formed by gathering a plurality of low-density regions in the island portion. The regular pattern may be, for example, a dot pattern (circle, ellipse, triangle, polygon, etc.), a herringbone pattern, a checkered pattern, a lattice pattern, a staggered pattern, an oblique stripe pattern, a spiral net pattern, or a zigzag pattern.

Specifically, the pattern forming support is, for example, a monofilament having a fiber diameter of about 0.1 mm to 1.2 mm, a warp density of 10 / inch to 30 / inch, and a weft density of 10 / inch to 30 / It may be plain fabrics, twill fabrics, and satin fabrics woven in inches. The support made of a relatively thick filament woven fabric has a convex portion at the intersection of the weft and the warp, thereby enabling the formation of a low density region. When such a woven fabric is used, the area per low density region is determined by the thickness of the yarn constituting the woven fabric, and the spacing and pitch of the low density region are determined by the warp / weft density of the fabric. Is done.

Alternatively, the pattern forming support includes convex portions and / or concave portions, for example, a truncated cone shape, a conical shape, a truncated pyramid shape, or a truncated pyramid shape projection, or a concave portion formed by subjecting the surface of a metal plate to cutting or the like. The portion other than the convex portion and / or the concave portion may be a plate-like member (for example, a metal plate) in which an opening having a small size is formed and water permeability is ensured.
Alternatively, the patterning support may be a spiral net.

The opening member is a member that is provided with an opening corresponding to the island-shaped portion and does not allow high-pressure fluid to pass through other than the opening, and may be, for example, a metal plate formed by punching the opening. When a high-pressure water stream is used as the high-pressure fluid, a small hole for draining may be provided in a portion other than the opening. Alternatively, when a high-pressure gas is used as the high-pressure fluid, a small hole may be provided in a portion other than the opening for the purpose of heat dissipation and pressure loss reduction. The small holes provided outside these openings do not substantially allow high-pressure fluid to pass through, or even if they pass through, the low-density region and the second high-density region are not formed by the high-pressure fluid that has passed (that is, The water flow that has passed through the hole does not have the energy necessary to form a low density region or the like) and is formed with a sufficiently small dimension.

The opening member may be a belt shape or a cylindrical drum. When a cylindrical drum is used, the island portion can be formed by a method in which a nozzle is arranged in the drum and a water flow is jetted while the drum is rotated. When a cylindrical drum is used, the equipment necessary for forming the second high-density region can be made relatively simple compared to the case where a belt-shaped opening member is used, and The space occupied by the facilities can be made relatively small. In addition, when using a drum, the drum rotates around its center as a rotation axis and cannot be slid on other members, so that it does not wear and deform the opening during rotation. It can be rotated at a high speed. Furthermore, since the opening member of the drum is formed by processing a metal plate or the like having a certain thickness to form an opening, even if it is used for a long period of time, it does not easily deteriorate over time (wear and deformation of the opening). A nonwoven fabric having a predetermined pattern can be stably produced over a long period of time.

When a nozzle is arranged in a drum using a cylindrical drum, a water flow can be applied to the web in an area corresponding to the opening of the drum, thereby suppressing water flow energy attenuation and disturbance of the water flow direction. be able to. On the other hand, when a drum is used, if the water flow is applied to the web from the side of the pattern forming support, the water flow is blocked by the support. Need to be high.

When using a belt-like opening member, equipment and space for continuously running a long plate-like member are required. Further, in the belt-shaped opening member, the belt is likely to be worn and deformed along with the belt conveyance, and the opening is likely to be deformed accordingly. Further, since the belt is made using a material that bends, the opening is likely to be deformed during long-term use. Since the opening determines the shape of the island portion, if it is deformed, the intended pattern may not be obtained in the nonwoven fabric.

The shape and area of the opening provided in the opening member are determined according to the shape and area of the island-shaped part to be formed. Or when the shape and area of the opening part of an opening member are decided beforehand, the shape and area of the island-shaped part formed are determined by the shape and area of an opening part. For example, the area per one opening may be, for example, 3mm ² ~ 18000mm ^2, may in particular 5 mm ² ~ 2000 mm ^2, more particularly can be a 19mm ² ~ 710mm ^2. Further, the total area of the openings may be 1% to 45%, particularly 3% to 40%, and more particularly 5% to 35% with respect to the total area of the opening member. And even more particularly from 7% to 30%. If the ratio of the area per opening and / or the total area of the openings is too large, the strength of the opening member may be reduced and the opening may be deformed, making it impossible to obtain the desired pattern in the nonwoven fabric. . An example of the shape of the opening is as described above in relation to the island-shaped portion.

The opening member may be arranged so that the opening member and the primary processing web do not contact each other, that is, a space exists between the opening member and the primary processing web. When a water flow is jetted in a state where the opening member and the primary processing web are in contact with each other, the opening member is pressed against the primary processing web by energy generated by the water flow. As a result, the surface shape (pattern or the like) of the opening member itself may be imparted to the nonwoven fabric, or the resulting nonwoven fabric may be compressed. These actions are unintended actions in the manufacturing method of the present embodiment.

The opening member may be arranged so that the distance between the opening member and the primary web is 0.5 cm to 5.0 cm, for example. The distance between the opening member and the primary working web may in particular be 1.0 cm to 3.0 cm, more particularly 1.5 cm to 2.5 cm. When the distance between the nozzle and the primary processing web is within the range described later, if the distance between the opening member and the primary processing web is short and the two are approaching, the opening member is accidentally placed on the primary processing web. Contact may occur, in which case breakage, wrinkles and fluff may occur in the primary web. Moreover, when both are approaching, the fiber treatment agent (oil agent) adhering to the fiber which comprises a web may adhere to an opening member, and the adhesion amount of the fiber treatment agent in a web is more than predetermined amount. There may be inconveniences due to the reduction. Attachment of the fiber treatment agent to the opening member may require cleaning of the opening member, or may promote deterioration of the opening member. Alternatively, if the distance between the nozzle and the primary processing web is within the range described below and the distance between the opening member and the primary processing web is short, the distance between the nozzle and the opening becomes long and the nozzle is ejected from the nozzle. In some cases, the generated water flow spreads before passing through the opening, and a part thereof is blocked by a portion other than the opening (a portion that does not allow liquid to permeate) to reach the primary processed web. As a result, a sufficient amount of water flow cannot be applied to the nonwoven fabric, and a nonwoven fabric having a clear pattern may not be obtained. On the other hand, when the distance between the two is long, the water flow after passing through the opening spreads and a nonwoven fabric having a target pattern may not be obtained.

The distance between the opening member and the nozzle may be, for example, 0.1 cm to 4.0 cm, particularly 0.3 cm to 3.0 cm, and more particularly 0.5 cm to 2.0 cm. As described above, when the distance between the opening member and the primary processing web is a desirable distance, if the distance between the opening member and the nozzle is short and they are close to each other, the opening member and the nozzle come into contact with each other. The member or nozzle may be worn or damaged. On the other hand, when the distance between the two is long, as described above, the water flow ejected from the nozzle spreads before passing through the opening, and part of the water flow is blocked by the portion other than the opening, and the primary processed web The nonwoven fabric having a clear pattern may not be obtained.

The distance between the nozzle and the primary processing web is the sum of the distance between the opening and the nozzle, the thickness of the opening member, and the distance between the opening and the primary processing web. Specifically, the distance between the nozzle and the primary processed web may be, for example, 3.6 cm to 12.0 cm, particularly 4.3 cm to 9.0 cm, and more particularly 5.0 cm to 8.0 cm. If the distance between the nozzle and the primary web is too short, breakage, wrinkles and fluff may occur in the primary web. Also, if the distance between the nozzle and the primary web is too short, an excessive energy stream is applied to the web and the water stream splashes on the web or support, creating turbulence on the web and creating the desired pattern. It may not be obtained. When the distance between the nozzle and the primary processed web is too long, a sufficient amount of water flow cannot be applied to the nonwoven fabric, and a nonwoven fabric having a clear pattern may not be obtained. In addition, when the distance between the nozzle and the primary processed web is too long, the water flow spreads in the opening member before reaching the web, the energy is attenuated, and a non-woven fabric having a clear pattern may not be obtained. .

FIG. 10 is a side view schematically showing the positional relationship among the nozzle, the drum as the opening member, the pattern forming support, and the primary processing web. As shown in the drawing, when the drum 34 is used as the opening member, the rotation direction of the drum 34 is generally a forward direction that coincides with the traveling direction of the pattern forming support 30 (that is, the conveyance direction of the primary processing web 32). is there. Further, the primary processed web 32 placed on the pattern forming support 30 is ejected from a nozzle 38 disposed in the drum 34 and is subjected to the action of a water flow that has passed through the opening 36 of the drum 34, thereby forming an island shape. Part is formed. In the drum 34, portions other than the opening portion 36 do not allow water to pass through, so that an island-shaped portion corresponding to the opening portion 36 is formed in the primary processed web 32. When the drum-shaped opening member 34 is used, water other than the water flow passing through the opening 36 may accumulate in the opening member 34. Such water is preferably discharged to the outside. The water accumulated in the opening member 34 may be discharged by, for example, sucking with a suction nozzle or draining from a drain opening provided in the opening member 34.

When the drum 34 is used as the opening member, the rotation speed of the drum 34 and the conveyance speed of the primary processing web 32 by the pattern forming support 30 are appropriately adjusted so that a desired island-shaped portion is formed. To do. Specifically, when the linear velocity when the drum 34 is rotated is substantially the same as the conveyance speed of the primary processing web 32, the pitch and interval of the island-shaped portions are the openings 36 formed in the drum 34. It will be almost the same as those. When the linear velocity when the drum 34 is rotated is larger than the conveying speed of the primary processing web 32, the island-like portions are denser (pitch and interval are shorter). Or when the linear velocity when rotating the drum 34 is smaller than the conveyance speed of the formation support body 30 of the primary process web 32, an island-like part is formed more sparsely (a pitch and an interval are longer). Become).

The nozzle and the water pressure range that may be used when forming the island-shaped portion are the same as those when forming the first high-density region. The islands are usually formed by spraying a water flow once on one side of the primary web. The pressure for forming the island-shaped portion may be particularly 1 MPa to 15 MPa, and more particularly 2 MPa to 10 MPa.

In the above description, the method for forming the island-shaped portion (low density region, second high density region) after first producing the primary processed web has been described. The method of producing the primary processed web first is preferable because a clear island-like portion (low density region and second high density region) can be formed on the appropriately entangled web. In another form, the production of the primary web and the formation of the islands may be performed simultaneously. For example, by arranging one or more nozzles on the outside of the drum and ejecting a high-energy fluid from the inside of the drum while ejecting a high-pressure fluid having a lower energy from the nozzle, under the patterning support A method of injecting a high-pressure fluid having a higher energy from the inside of the drum while applying a high-pressure fluid having a lower energy from the side, and a method of injecting a high-energy high-pressure fluid from the inside of the drum while thermally bonding the whole nonwoven fabric in a high temperature atmosphere Thus, the production of the primary processed web and the formation of the island portions can be performed simultaneously.

In yet another embodiment, the primary processed web may be produced regardless of the entanglement treatment with the high-pressure fluid. For example, the primary processed web may be produced by a method of adhering the fibers by melting a part of the fibers (for example, the sheath component of the core-sheath type composite fiber described above) by heat treatment or the like. You may produce by the method of mutually bonding using a suitable binder. Alternatively, the primary processed web may be produced by combining entanglement treatment with high-pressure fluid and adhesion treatment.

The web (hereinafter, also referred to as “secondary processed web”) in which the first high-density region and the island-shaped portion (low-density region, second high-density region) are formed by the above method is subjected to a drying process for removing moisture. It may be used as it is as the nonwoven fabric of this embodiment. When the secondary processed web contains synthetic fibers and a part or all of the fiber surface of the synthetic fibers is formed of a resin having a relatively low melting point such as polyethylene, the fibers are bonded to each other with a low melting point resin. You may attach | subject to the heat bonding process made to heat-bond. The thermal bonding treatment is preferably performed at a temperature at which the lowest melting point among the thermoplastic resins constituting the surface of the synthetic fiber is melted or softened. When the synthetic fiber is, for example, a single fiber or a composite fiber in which a part or all of the fiber surface is made of polyethylene, the thermal bonding treatment is preferably performed at a temperature of 130 ° C. or higher and 150 ° C. or lower. The degree of thermal bonding can also be changed by adjusting the heat treatment temperature. The degree of thermal bonding affects the strength, flexibility, and touch of the nonwoven fabric.

The thermal bonding process may also serve as a drying process for removing moisture from the secondary processed web. Alternatively, the thermal bonding process and the drying process may be performed separately. The thermal bonding may be performed using a hot air through heat treatment machine (also referred to as an air-through heat treatment machine), a hot air blowing heat treatment machine, an infrared heat treatment machine, or a hot roll (including a hot emboss roll).

Adhesion using a synthetic fiber constituent resin as an adhesive component may be performed by, for example, irradiation with an electron beam or ultrasonic welding. Or you may implement adhesion | attachment of fibers using a binder.

The nonwoven fabric of the present embodiment exhibits a unique design effect by forming a pattern by combining three different fiber density regions. Moreover, in the nonwoven fabric of this embodiment, the independent island-shaped part forms the pattern, and since the 2nd high density area | region which is entangled with high fiber density is scattered, like patent document 2 Compared with the nonwoven fabric in which a pattern is formed in a stripe shape, the strength balance in the vertical direction and the horizontal direction is good.

Furthermore, the nonwoven fabric of the present embodiment has a shape and area per low density region and a ratio (area ratio) of the entire low density region to the nonwoven fabric, a shape and area per island portion, and the entire island portion. By adjusting the ratio (area ratio) occupied by the nonwoven fabric, the performance according to the use of the nonwoven fabric can be optimized. For example, when used as a surface material of an absorbent article, tactile sensation and liquid absorbency, etc., when used as an interpersonal wiper, wiping and handling properties, etc. By changing the area ratio or the like, it is possible to adjust appropriately.

The nonwoven fabric of this embodiment can be suitably used as a surface material for absorbent articles such as napkins and panty liners. When used as a surface material of an absorbent article, the low density region serves as an entrance for transferring menstrual blood and the cage to the absorber side, and promotes that they are quickly transferred to the absorber. Or the nonwoven fabric of this embodiment can be used as an objective wiper, an interpersonal wiper, a towel, a face mask, a mask, a filter, and a poultice.

Hereinafter, the nonwoven fabric of this embodiment is demonstrated by an Example.
Example 1
Viscose rayon with a fineness of 1.7 dtex and a fiber length of 40 mm (trade name CD, manufactured by Daiwabo Rayon Co., Ltd.), high-density polyethylene with a fineness of 1.7 dtex and a fiber length of 51 mm as a sheath component, and a core as a core component. A sheath type composite fiber (trade name NBF (H) P, manufactured by Daiwabo Polytech Co., Ltd.) was prepared. 80% by mass of rayon and 20% by mass of core-sheath type composite fiber were mixed to prepare a parallel web having a target weight of about 40 g / m ² .

The web was subjected to hydroentanglement treatment for forming a first high-density region.
In the hydroentanglement process, the web is placed on a 90 mesh plain weave support made of monofilaments having a wire diameter of 0.132 mm, and one of the webs using a nozzle provided with orifices having a pore diameter of 0.12 mm at intervals of 0.6 mm. A 2.5 MPa columnar water flow was injected once on the surface, and a 2.5 MPa columnar water flow was injected once on the other surface. At this time, the speed of the support was 4 m / min, and the distance between the nozzle and the web was 20 mm.

Next, the hydroentanglement process for forming an island-like part (low density area | region and 2nd high density area | region) was implemented.
In hydroentanglement, the web having the first high-density region is placed on a 25-mesh plain weave support (both warp and weft density is 25 / inch) made of monofilaments with a wire diameter of 0.7 mm and circular with a diameter of 5 mm. The drums are arranged in a staggered pattern with a diagonal pitch of 15 mm, a diagonal spacing of 10 mm, a lateral pitch of 10 mm, and a lateral spacing of 5 mm, and nozzles are arranged in the drum. The water flow was jetted from the nozzle. The drum was formed by punching an opening in a metal plate having a thickness of 3 mm. The distance between the nozzle and the web was 40 mm, the distance between the nozzle and the drum was 20 mm, and the distance between the web and the drum was 20 mm.

The nozzle had the same specifications as those used when forming the first high-density region. The pressure of the columnar water flow was 2 MPa, and the columnar water flow was jetted once on one side of the web. During the hydroentanglement process, the drum was rotated at a speed of 4.3 rpm and the support was run at a speed of 4 m / min. Since the columnar water flow passes only through the opening of the drum and hits the web on the support, the water entanglement was performed only at the portion corresponding to the opening. In addition, the support is made of a filament that is thicker than the support used when forming the first high-density region, and a relatively large convex portion is formed at the weaving intersection. The fibers on the convex part of the body moved to the surroundings by the water flow, and a low density region was formed. At the same time, the moved fibers were entangled to form a second high density region.

In the obtained non-woven fabric, most of the low density region is an opening, and the vertical pitch is 3 mm and the horizontal pitch is 2 mm, the vertical interval is 2 mm and the horizontal interval is 1 mm, the diagonal pitch is 2 mm, They were formed in a zigzag pattern with a diagonal spacing of 1 mm. The islands are circular with a diameter of about 5 mm, each having about 7 low-density regions, a vertical pitch of 20 mm, a horizontal pitch of 8.3 mm, a vertical interval of 11 mm, and a horizontal direction. They were arranged in a zigzag pattern with a spacing of 6 mm, a diagonal pitch of 10.8 mm, and a diagonal spacing of 5.8 mm. Moreover, the area ratio of the island-shaped part occupied in the nonwoven fabric was 23.6%, and the area ratio of the low density region occupied in the nonwoven fabric was 3.3%.

After forming the island portions, the web was dried using a dryer set at 80 ° C., and then the core-sheath composite fiber polyethylene was melted or melted using a hot-air through heat treatment machine set at 135 ° C. The fibers were softened to thermally bond the fibers together. The drying and heat bonding processes were performed for 10 seconds. A photograph showing the surface of the obtained nonwoven fabric is shown in FIG.

(Example 2)
In hydroentanglement processing to form islands (low density area and second high density area), circular openings with a diameter of 5 mm have a diagonal pitch of 9.6 mm, a diagonal spacing of 3.2 mm, and a horizontal width. A nonwoven fabric was obtained in the same procedure as in Example 1 except that drums arranged in a staggered manner with a pitch of 10 mm in the direction and a spacing of 5 mm in the horizontal direction were used.

In the obtained non-woven fabric, most of the low density region is an opening, and the vertical pitch is 3 mm and the horizontal pitch is 2 mm, the vertical interval is 2 mm and the horizontal interval is 1 mm, the diagonal pitch is 2 mm, They were formed in a zigzag pattern with a diagonal spacing of 1 mm. In addition, the islands are circular with a diameter of about 5 mm, each having about 7 low-density regions, a vertical pitch of 11.1 mm, a horizontal pitch of 8.3 mm, and a vertical interval of 6.1 mm. Further, they were arranged in a zigzag pattern with a lateral spacing of 3.3 mm, a diagonal pitch of 6.9 mm, and a diagonal spacing of 1.9 mm. Moreover, the area ratio of the island-shaped part occupied in the nonwoven fabric was 42.3%, and the area ratio of the low density region occupied in the nonwoven fabric was 11.8%.

(Example 3)
In the hydroentanglement process for forming islands (low density region and second high density region), rhombus openings having a diagonal of 15 mm in the vertical direction and a diagonal of 15 mm in the horizontal direction have a pitch of 53.2 mm in the diagonal direction. A non-woven fabric was obtained in the same manner as in Example 1 except that a square array was used with a diagonal spacing of 47.6 mm, a lateral pitch of 32.4 mm, and a lateral spacing of 18.0 mm. It was.

In the obtained non-woven fabric, most of the low density region is an opening, and the vertical pitch is 3 mm and the horizontal pitch is 2 mm, the vertical interval is 2 mm and the horizontal interval is 1 mm, the diagonal pitch is 2 mm, They were formed in a zigzag pattern with a diagonal spacing of 1 mm. Each island-shaped portion is a rhombus having about 24 low-density regions and having a diagonal of 15 mm in the direction and a diagonal of 15 mm in the horizontal direction. The vertical pitch is 27.2 mm and the horizontal pitch is 27.3 mm. They were formed in a square arrangement with a vertical spacing of 12.1 mm, a lateral spacing of 12.2 mm, a diagonal pitch of 38.3 mm, and a diagonal spacing of 28.1 mm. Moreover, the area ratio of the island-shaped part which occupies for a nonwoven fabric was 16.0%, and the area ratio of the low-density area | region which occupies for a nonwoven fabric was 6.1%.

(Example 4)
In hydroentanglement processing to form islands (low density region and second high density region), circular openings with a diameter of 5 mm have a diagonal pitch of 11.6 mm, a diagonal spacing of 5.6 mm, A nonwoven fabric was obtained in the same procedure as in Example 1 except that drums arranged in a staggered manner with a pitch of 10 mm in the direction and a spacing of 5 mm in the horizontal direction were used.

In the obtained non-woven fabric, most of the low density region is an opening, and the vertical pitch is 3 mm and the horizontal pitch is 2 mm, the vertical interval is 2 mm and the horizontal interval is 1 mm, the diagonal pitch is 2 mm, They were formed in a zigzag pattern with a diagonal spacing of 1 mm. In addition, the island-shaped portion has a circular shape with a diameter of about 5 mm, each having about 7 low-density regions, a vertical pitch of 14.3 mm, a horizontal pitch of 8.3 mm, and a vertical interval of 9.3 mm. Further, they were arranged in a zigzag pattern with a lateral spacing of 3.3 mm, a diagonal pitch of 8.3 mm, and a diagonal spacing of 3.3 mm. Moreover, the area ratio of the island-shaped part which occupies for a nonwoven fabric was 32.9%, and the area ratio of the low density area | region which occupies for a nonwoven fabric was 9.2%.

(Comparative Example 1)
A nonwoven fabric was obtained in the same procedure as in Example 1 except that the hydroentanglement process for forming the second high-density region was not performed.

(Comparative Example 2)
A nonwoven fabric was obtained by the same procedure as that of Example 1 except that the hydroentanglement process for forming the second high-density region was performed without using an opening member. In the obtained nonwoven fabric, a low density region was formed over the entire surface, and no island-shaped portion was formed. The area ratio of the low density area | region in a nonwoven fabric was 28.0%.

(Comparative Example 3)
After forming the first high-density region by the same procedure as that of Example 1, a water entangling process was performed using a nozzle that blocked a part of the orifice. Specifically, a part of the orifice of the nozzle was closed so that an area of about 5 mm not closing the orifice and an area of about 16.5 mm closing the orifice were alternately present. The support was the same as that used in forming the second high-density region in Example 1, and the water pressure and the speed of the support were the same as those used in forming the second high-density region in Example 1. . Then, in the same manner as in Example 1, drying treatment and heat bonding treatment were performed to obtain a nonwoven fabric. In the obtained non-woven fabric, a striped pattern was obtained in which rows in which the low-density region and the second high-density region were formed and rows in the first high-density region were alternately arranged in the horizontal direction. . In Comparative Example 3, the ratio of the low density region to the entire nonwoven fabric was the same as that in Example 1.

(Comparative Example 4)
During the hydroentanglement process after forming the first high-density region, a part of the orifice was blocked so that the region that did not block the orifice was approximately 2 mm, and the region that blocked the orifice was approximately 6.5 mm. A nonwoven fabric was produced in the same procedure as that of Comparative Example 3 except that the nozzle was used. In Comparative Example 4, the ratio of the low density region to the entire nonwoven fabric was the same as that in Example 1.

(Comparative Example 5)
In hydroentanglement processing to form islands (low density region and second high density region), circular openings with a diameter of 5 mm have a diagonal pitch of 7.8 mm, a diagonal spacing of 1.7 mm, and a horizontal width. A nonwoven fabric was obtained in the same procedure as in Example 1 except that drums arranged in a staggered pattern with a pitch of 7.3 mm in the direction and a spacing of 1.5 mm in the horizontal direction were used.

In the obtained non-woven fabric, most of the low density region is an opening, and the vertical pitch is 3 mm and the horizontal pitch is 2 mm, the vertical interval is 2 mm and the horizontal interval is 1 mm, the diagonal pitch is 2 mm, They were formed in a zigzag pattern with a diagonal spacing of 1 mm. The islands have a circular shape with a diameter of about 5 mm, each having about 7 low-density regions, a vertical pitch of 10 mm, a horizontal pitch of 6 mm, a vertical interval of 5 mm, and a horizontal interval of 1 mm. They were formed in a staggered pattern with a diagonal pitch of 5.6 mm and a diagonal spacing of 1 mm. Moreover, the area ratio of the island-shaped part which occupies for a nonwoven fabric was 62.4%, and the area ratio of the low density area | region which occupies for a nonwoven fabric was 17.6%.

The nonwoven fabrics obtained in Examples 1 to 4 and Comparative Examples 1 to 5 were evaluated for the following physical properties by the methods described below. The evaluation results are shown in Table 1.

<Breaking strength, breaking elongation, 10% elongation stress>
In accordance with JIS L 1096 6.12.1 A method (strip method), using a constant-speed tension type tensile tester, tension was performed under the conditions of a sample piece width of 5 cm, a grip interval of 10 cm, and a tensile speed of 30 ± 2 cm / min. It attached to the test and measured the load value at the time of a cutting | disconnection (breaking strength), breaking elongation, and the stress at the time of 10% elongation. The tensile test was carried out with the longitudinal direction (MD direction) and the lateral direction (CD direction) of the nonwoven fabric as the tensile direction. All the evaluation results are shown as an average of values measured for three samples.

<Designability>
The design properties of the obtained nonwoven fabric were evaluated according to the following criteria.
A: The boundary between the island-like portions adjacent to each other is clear, and the symbols indicated by the island-like portions can be sufficiently recognized.
B: The boundary between adjacent island portions is slightly clear, and the pattern indicated by the island portions can be recognized.
C: The boundary between adjacent island portions is unclear, and the symbol indicated by the island portions cannot be recognized.

The nonwoven fabrics of Examples 1 to 4 had higher stress at 10% elongation than Comparative Examples 1 and 2. This is because, in comparison with Comparative Example 1, Examples 1 to 4 are subjected to the hydroentanglement process for forming the second high-density region, and therefore the fiber entanglement is advanced by that amount. . Further, in Comparative Example 2, a region having a high fiber density located between the low density region and the low density region is formed on the entire surface, and therefore, due to the region having a higher fiber density than the strength decrease caused by the formation of the low density region. It is inferred that the stress at the time of elongation is higher than that of Comparative Example 1 by the improvement in strength. In the nonwoven fabrics of Examples 1 to 4, the area ratio of the low density region is smaller than that of Comparative Example 2, and the fiber density of the second high density region formed between the low density regions is higher. Since they were firmly entangled with each other, the strength improvement by the second high density region became more dominant, and it is considered that the stress at 10% elongation was significantly improved as compared with Comparative Example 2. In addition, when providing a nonwoven fabric as a surface material of an absorbent article, an interpersonal wiper, or the like, the nonwoven fabric is often stretched by about 10% at the time of processing or use. Compared.

In the nonwoven fabrics of Examples 1 to 4, in comparison with Comparative Example 1, an improvement in stress at 10% elongation due to the formation of the pattern was observed in both the vertical direction and the horizontal direction. On the other hand, the nonwoven fabrics of Comparative Examples 3 and 4 did not show an improvement in the stress at 10% elongation in the transverse direction in comparison with Comparative Example 1. This is because, in Examples 1 to 4, islands forming the pattern are scattered in the nonwoven fabric, and unlike Comparative Examples 3 and 4, the part forming the pattern (low density regions are gathered) It was thought that this was due to the fact that the part) was not continuous in the longitudinal or transverse direction of the nonwoven fabric. The nonwoven fabric of Comparative Example 5 was inferior in design properties because the area ratio of the island-shaped part was large. Further, the stress at 10% elongation of Comparative Example 5 was smaller than the stress at elongation of Examples 1 to 4. This was considered due to the fact that the area ratio of the low density region was larger than that of Examples 1 to 4. Also, among Examples 1 to 4, the stress at 10% elongation of Example 2 is the lowest because the area ratio of the low density region of Example 2 is compared with Examples 1, 3 and 4. It was thought to be due to the largeness.

For the nonwoven fabrics of Examples 1 and 2 and Comparative Example 5, the cross section of the first high-density region and the island-shaped portion was observed with an electron microscope to determine the thickness. From the thickness of the nonwoven fabric and the basis weight of the nonwoven fabric, The fiber densities of the first high density region and the second high density region were determined. The thickness of the nonwoven fabric was measured at four locations for each region, the fiber density was determined for each of the four locations, and the average value thereof was taken as the fiber density for each region. As a result, in the nonwoven fabric of Example 1, the fiber density in the first high-density region was 0.080 g / cm ³ and the fiber density in the second high-density region was 0.089 g / cm ³ . In the nonwoven fabric of Example 2, the fiber density in the first high-density region was 0.077 g / cm ³ , and the fiber density in the second high-density region was 0.092 g / cm ³ . In the nonwoven fabric of Comparative Example 5, the fiber density in the first high density region was 0.082 g / cm ³ , and the fiber density in the second high density region was 0.093 g / cm ³ .

The present disclosure includes the following aspects.
(Aspect 1)
A patterned nonwoven fabric having a low density region, a first high density region, and a second high density region,
A plurality of the low-density regions are assembled to form one island-shaped portion,
In the one island-shaped portion, the second high-density region is formed at least between the low-density region and the low-density region,
The first high-density region is formed between the island-shaped portion and the island-shaped portion;
The fiber density in the first high-density region is smaller than the fiber density in the second high-density region,
The fiber density in the low density region is smaller than the fiber density in the first high density region, or the low density region is an aperture.
The total area of the low-density regions is 0.1% to 12% with respect to the entire area of the patterned nonwoven fabric, and the total area of the island-shaped portions is relative to the entire area of the patterned nonwoven fabric. 1% to 45%,
Patterned nonwoven fabric.
(Aspect 2)
The patterned nonwoven fabric according to aspect 1, wherein the low-density region is a recess or an opening, and the plurality of low-density regions formed in the island-like part form a regular pattern.
(Aspect 3)
The pattern according to aspect 2, wherein the regular pattern is at least one pattern selected from the group consisting of a dot pattern, a herringbone pattern, a checkered pattern, a lattice pattern, a staggered pattern, an oblique stripe pattern, a wave pattern, and a zigzag pattern Nonwoven fabric with.
(Aspect 4)
The area per low-density region, one is 0.03mm ² ~ 20mm ^2,
The low-density regions are arranged in a staggered arrangement or a square arrangement in which a pitch in at least one direction is 0.1 mm to 50 mm and an interval in at least one direction is 0.1 mm to 50 mm. The nonwoven fabric with a pattern according to any one of 3 above.
(Aspect 5)
The island area per one of which is 1.0mm ² ~ 18000mm ^2, embodiment 1-4 either patterned nonwoven fabric.
(Aspect 6)
The island-shaped portions are arranged in a staggered arrangement, a square arrangement, or a diamond pattern in which a pitch in at least one direction is 5 mm to 100 mm and an interval in at least one direction is 1 mm to 100 mm. The patterned nonwoven fabric according to any one of 5 above.
(Aspect 7)
The patterned nonwoven fabric according to any one of aspects 1 to 6, wherein the fibers are entangled with each other.
(Aspect 8)
A low-density region, a first high-density region, and a second high-density region, wherein a plurality of the low-density regions are aggregated to form one island-shaped portion; The fiber density is smaller than the fiber density in the second high density region, the fiber density in the low density region is smaller than the fiber density in the first high density region, or the low density region is an aperture. A method for producing a patterned nonwoven fabric,
Preparing the web,
Forming a first high-density region by subjecting the entire surface of the web to entanglement treatment and / or adhesion treatment; and on the support having at least one selected from a convex portion, a concave portion and an opening portion. And a member that has a plurality of openings between the web and the nozzle that injects the high-pressure fluid, and a portion other than the openings does not allow the high-pressure fluid to pass through (hereinafter referred to as “opening member”). The high-pressure fluid is ejected from the nozzle and the high-pressure fluid that has passed through the opening is applied to the web to form a low-density region and a second high-density region. ,
A method for producing a patterned nonwoven fabric.
(Aspect 9)
The opening member is a drum having an opening;
The distance between the drum and the web is 0.5 cm to 5.0 cm;
The nozzle is disposed in the drum;
The drum is rotated while jetting the high pressure fluid.
The manufacturing method of the nonwoven fabric with a pattern of aspect 8.
(Aspect 10)
The manufacturing method of the nonwoven fabric with a pattern of aspect 8 or 9 whose said high pressure fluid is a high pressure liquid.

In the patterned nonwoven fabric of the present embodiment, the island-shaped portion composed of a plurality of low density regions and a second high density region formed between the low density regions has a fiber density smaller than that of the second high density region. Since it is formed in a high-density region and exhibits a high design effect, it can be used for products that are easily caught by the user, such as surface materials for absorbent articles, interpersonal wipers, objective wipers, etc. .

DESCRIPTION OF SYMBOLS 10 Low density area | region 12 1st high density area | region 14 2nd high density area | region 20 Island-like part 100 Nonwoven fabric 30 Pattern formation support body 32 Web 34 Drum (opening member)
36 Opening 38 Nozzle

Claims (10)

1. A patterned nonwoven fabric having a low density region, a first high density region, and a second high density region,
   A plurality of the low-density regions are assembled to form one island-shaped portion,
   In the one island-shaped portion, the second high-density region is formed at least between the low-density region and the low-density region,
   The first high-density region is formed between the island-shaped portion and the island-shaped portion;
   The fiber density in the first high-density region is smaller than the fiber density in the second high-density region,
   The fiber density in the low density region is smaller than the fiber density in the first high density region, or the low density region is an aperture.
   The total area of the low-density regions is 0.1% to 12% with respect to the entire area of the patterned nonwoven fabric, and the total area of the island-shaped portions is relative to the entire area of the patterned nonwoven fabric. 1% to 45%,
   Patterned nonwoven fabric.
2. The patterned nonwoven fabric according to claim 1, wherein the low-density region is a recess or an opening, and the plurality of low-density regions formed in the island-like part form a regular pattern.
3. The regular pattern is at least one pattern selected from the group consisting of a dot pattern, a herringbone pattern, a checkered pattern, a lattice pattern, a staggered pattern, an oblique stripe pattern, a wave pattern, and a zigzag pattern. The patterned non-woven fabric.
4. The area per low-density region, one is 0.03mm ² ~ 20mm ^2,
   The low-density region is arranged in a staggered arrangement or a square arrangement in which a pitch in at least one direction is 0.1 mm to 50 mm, and an interval in at least one direction is 0.1 mm to 50 mm. The patterned nonwoven fabric according to any one of items 1 to 3.
5. Area per one said island portion is 1.0mm ² ~ 18000mm ^2, patterned nonwoven fabric according to any one of claims 1-4.
6. 2. The island-shaped portions are arranged in a staggered arrangement, a square arrangement, or a diamond pattern in which a pitch in at least one direction is 5 mm to 100 mm and an interval in at least one direction is 1 mm to 100 mm. The patterned nonwoven fabric according to any one of 1 to 5.
7. The patterned nonwoven fabric according to any one of claims 1 to 6, wherein in the nonwoven fabric, fibers are entangled with each other.
8. A low-density region, a first high-density region, and a second high-density region, wherein a plurality of the low-density regions are aggregated to form one island-shaped portion; The fiber density is smaller than the fiber density in the second high density region, the fiber density in the low density region is smaller than the fiber density in the first high density region, or the low density region is an aperture. A method for producing a patterned nonwoven fabric,
   Preparing the web,
   Forming a first high-density region by subjecting the entire surface of the web to entanglement treatment and / or adhesion treatment; and on the support having at least one selected from a convex portion, a concave portion and an opening portion. And a member that has a plurality of openings between the web and the nozzle that injects the high-pressure fluid, and a portion other than the openings does not allow the high-pressure fluid to pass through (hereinafter referred to as “opening member”). The high-pressure fluid is ejected from the nozzle and the high-pressure fluid that has passed through the opening is applied to the web to form a low-density region and a second high-density region. ,
   A method for producing a patterned nonwoven fabric.
9. The opening member is a drum having an opening;
   The distance between the drum and the web is 0.5 cm to 5.0 cm;
   The nozzle is disposed in the drum;
   The drum is rotated while jetting the high pressure fluid.
   The manufacturing method of the nonwoven fabric with a pattern of Claim 8.
10. The method for producing a patterned nonwoven fabric according to claim 8 or 9, wherein the high-pressure fluid is a high-pressure liquid.

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