JP5858776B2 - Non-woven - Google Patents

Description

  The present invention relates to a nonwoven fabric.

Absorbent articles such as sanitary napkins, panty liners, disposable diapers, etc., depending on its function, those with a protruding part on one side of the sheet material, those with a protruding part, and many Products with small holes have been developed.
In Patent Document 1, in an uneven or undulating sheet material, convex portions and open concave portions are dispersed throughout, and the fiber aggregate density of the concave portions is more than the fiber aggregate density of the convex portions. Low ones are disclosed. Thereby, it is said that the leakage of the high-viscosity body fluid is surely suppressed or prevented, and also has other necessary characteristics, and has excellent performance as a surface material of the absorbent article. .
In the nonwoven fabric disclosed in Patent Document 1, FIG. 1 of Patent Document 1 shows a state in which the fibers around the aperture are annularly oriented. For this reason, since the absorption speed of the liquid around the opening is suppressed, the liquid passing speed may be slow.

In Patent Document 2, in the surface sheet of an absorbent article made of a nonwoven fabric having a large number of openings, the openings are surrounded by the nonwoven fabric so as to extend from the surface of the surface sheet toward the back surface. A surface sheet of an absorbent article that is curved in a convex shape so as to have a top between adjacent openings is disclosed. Further, a>b> c between the sheet thickness a at the top, the sheet thickness c at the peripheral edge of the lower end of the opening, and the sheet thickness b at a substantially middle part between the top and the peripheral edge of the lower end of the opening. It is said that there is a relationship. Thereby, a surface sheet will have a sparse / dense structure, a liquid residue will reduce, and the surface sheet excellent in the dry feeling will be obtained. Moreover, since the fiber density of the part which touches skin is sparse, in addition to being able to give softness like a cushion to skin, it is supposed that texture is further improved.
In the nonwoven fabric disclosed in Patent Literature 2, when the nonwoven fabric was produced by the production method disclosed in Patent Literature 2, it was confirmed that the orientation of the fibers around the apertures was circular. For this reason, since the absorption speed of the liquid around the opening is suppressed, the liquid passing speed may be slow.

Patent Document 3 discloses a multilayer nonwoven fabric in which one side of a sheet material is a protruding portion extending in a streak shape, and the cross-section thereof is a kamaboko (substantially semicircular) shape. The groove part in this nonwoven fabric is formed so that the basis weight is the lowest in the nonwoven fabric, the content of the horizontally oriented fibers is high, and the content of the vertically oriented fibers is low. And the side part of a convex-shaped part has the highest fabric weight in a nonwoven fabric, and the content rate of a longitudinally-oriented fiber is high. As a result, it becomes easy to allow a predetermined liquid such as excrement to pass through, and since the liquid falls into the groove portion, the diffusion area is small (spot property), the contact area with the skin is small (good tactile property), and the liquid return is suppressed. The Therefore, it is difficult for the liquid to remain on the sheet surface (low persistence), and it is possible to prevent the liquid from adhering widely to the skin for a long time.
In the nonwoven fabric disclosed in Patent Document 3, since the fiber density of the convex portion is higher than that of the groove portion, the liquid accumulated in the groove portion hardly flows to the convex portion side, and the liquid passing speed is slow. Moreover, since the convex part is not easily crushed by the pressure at the time of wearing, the cushioning property is low.

Japanese Patent Laid-Open No. 03-137258 Japanese Patent Laid-Open No. 08-246321 JP 2008-025081 A

  An object of the present invention is to provide a non-woven fabric that is not easily crushed and has good cushioning properties, and that facilitates the flow of liquid to increase the absorption rate from the through holes.

  The present invention includes a first projecting portion projecting to the first surface side of the sheet-like nonwoven fabric in plan view, and a second projecting portion projecting to the second surface side opposite to the first surface side. The first and second protrusions are alternately and continuously arranged in different directions intersecting in plan view of the nonwoven fabric, and have a through hole at the top of the plurality of second protrusions, The fibers around the through holes provide a non-woven fabric that is oriented toward the center of the through holes.

  The nonwoven fabric of the present invention has an effect that the fibers around the through holes are oriented toward the center direction of the through holes, so that the cushioning properties are good, the protruding portions are hardly crushed, and the cushioning properties are maintained. Moreover, since there exists a through-hole in the top part of a 2nd protrusion part, absorption speed becomes quick, and also the supplied liquid becomes easy to flow along an orientation direction.

It is the fragmentary sectional perspective view which showed typically the principal part which showed preferable one Embodiment of the nonwoven fabric of this invention. It is a transverse cross section of the 2nd projection part around the penetration hole showing the position which measures the orientation of the nonwoven fabric of the present invention. It is the cross-sectional view of the center part in the height direction of the 2nd protrusion part which showed the position which measures the orientation of the nonwoven fabric of this invention. It is a longitudinal cross-sectional view of the 2nd protrusion part around the through-hole of the nonwoven fabric of this invention. It is the plane arrangement | positioning figure which showed the example of arrangement | positioning of the 1st, 2nd protrusion part of the nonwoven fabric of this invention. It is principal part sectional drawing which showed a preferable example of the manufacturing method of the nonwoven fabric of this invention. It is the perspective view which notched partially the disposable diaper which applied the nonwoven fabric of this invention to the surface sheet, and was shown typically.

A preferred embodiment of the nonwoven fabric according to the present invention will be described below with reference to FIGS. 1 to 4.
The nonwoven fabric 10 of the present invention is preferably applied to a surface sheet of an absorbent article such as a sanitary napkin or a disposable diaper. The first surface side Z1 is used with the skin surface side of the wearer, and the second surface side Z2 is used. Is preferably disposed on the absorbent body (not shown) side inside the absorbent article. Hereinafter, although it demonstrates considering the embodiment which uses the 1st surface side Z1 of the nonwoven fabric 10 shown in drawing toward a wearer's skin surface, this invention is limited to this and is not interpreted.

  As shown in FIG. 1, the nonwoven fabric 10 of the present invention has a first protrusion 11 protruding from the first surface side Z1 on the side of the sheet-like nonwoven fabric in plan view and having an internal space 11K, and the first surface side Z1. It has the 2nd protrusion part 12 which protrudes in the 2nd surface side Z2 of an other side, and has the internal space 12K. These 1st, 2nd protrusion parts 11 and 12 are distribute | arranged alternately by each of the different direction which crosses planar view over the whole surface of the nonwoven fabric 10, for example. The different direction is, as a specific example, an X direction which is one direction of the different directions and a Y direction which is one direction of the different directions unlike the X direction. Here, the convex portion viewed from the first surface side Z <b> 1 is the first projecting portion 11, and the concave portion is the second projecting portion 12. Further, the convex portion viewed from the second surface side Z <b> 2 is the second projecting portion 12, and the concave portion is the first projecting portion 11. Therefore, the first protrusion 11 and the second protrusion 12 are partially shared.

  In this embodiment, the 1st, 2nd protrusion parts 11 and 12 are made into the truncated cone shape or hemisphere which rounded the top parts 11T and 12T, and the through-hole 21 is formed in the top parts 12T of the some 2nd protrusion part 12. FIG. have. More specifically, the protruding shape of the first protruding portion 11 is somewhat hemispherical, while the protruding shape of the second protruding portion 12 is a cone or truncated cone shape with a round top. In addition, in this embodiment, the 1st, 2nd protrusion parts 11 and 12 are not limited to the said shape, What kind of protrusion form may be sufficient, for example, various cone shape (In this specification, cone shape is It is practical to include a cone, a truncated cone, a pyramid, a truncated pyramid, an oblique cone, etc.). In this embodiment, the 1st, 2nd protrusion parts 11 and 12 hold | maintain the frustoconical shape or hemispherical internal space 11K and 12K with a round top part similar to the outer diameter.

  A wall 13 is provided between the top of the first protrusion 11 (hereinafter also referred to as the first protrusion 11) 11T and the opening 11H. The wall portion 13 forms an annular structure in the first projecting portion 11. Moreover, it has the wall part 14 between the top part (henceforth the 2nd protrusion part top part) 12T of the 2nd protrusion part 12, and its opening part 12H. The wall portion 14 forms an annular structure in the second projecting portion 12. The wall portion 14 is shared with a part of the wall portion 13. The “annular” herein is not particularly limited as long as it has a series of endless shapes in plan view, and may be any shape such as a circle, an ellipse, a rectangle, or a polygon in plan view. In order to maintain the continuous state of the sheet suitably, a circle or an ellipse is preferable. Furthermore, if the "annular" is considered as a three-dimensional shape, a cylindrical shape, a slanted columnar shape, an elliptical columnar shape, a truncated cone shape, a truncated oblique cone shape, a truncated elliptical cone shape, a truncated quadrangular pyramid shape, a truncated oblique pyramid shape Arbitrary ring structures, such as a shape, are mentioned, In order to implement | achieve a continuous sheet | seat state, cylindrical shape, elliptic cylinder shape, truncated cone shape, and truncated elliptical cone shape are preferable.

The nonwoven fabric 10 having the first and second projecting portions 11 and 12 arranged as described above does not have a bent portion, and is configured by a curved surface that is continuous as a whole.
Thus, it is preferable that the said nonwoven fabric 10 has a structure continuous in the surface direction. This “continuous” means that there are no small holes other than the intermittent portions and the through holes 21. However, fine holes such as gaps between fibers are not included in the small holes. The small hole can be defined, for example, as a hole having a diameter equivalent to a circle of 1.0 mm or more.

The fibers around the through hole 21 are oriented toward the center of the through hole 21.
The fibers constituting the wall 13 of the first protrusion 11 have fiber orientation in the direction connecting the first protrusion top 11T and the edge of the opening 11H. In other words, it has fiber orientation in the direction in which the wall portion 13 stands. Therefore, it has the radial fiber orientation which goes to the 1st protrusion part top part 11T.
The fibers constituting the wall portion 14 of the second protrusion 12 have fiber orientation in the direction connecting the second protrusion top 12T and the edge of the opening 12H. In other words, the fibers constituting the wall portion 14 have a radial fiber orientation toward the second protrusion top portion 12T. The fiber orientation of the wall portion 14 is the same as the fiber orientation of the wall portion 13 at the common portion with the wall portion 13 described above.

Further, as shown in FIG. 2, the wall portion 14hX crossed by the virtual line Lhx along the first direction X in the cross section passing through the center point Mh of the cross section of the through hole 21 and the center point Mh The orientation of the fibers of the wall portion 14hY crossed by the virtual line Lhy along the second direction Y in the transverse section passing through is as follows. For example, when the Mh direction is 90 °, the orientation angle of the wall portion 14hX is 50 ° to 130 °, preferably 55 ° to 125 °, and more preferably 60 ° to 120 °. The orientation angle of the wall portion 14hY is 50 ° to 130 °, preferably 55 ° to 125 °, more preferably 60 ° to 120 ° when the Mh direction is 90 °. The orientation strength of the wall portion 14hX is 1.05 or more, more preferably 1.1 or more. The orientation strength of the wall portion 14hY is 1.05 or more, and more preferably 1.1 or more.
As described above, the fibers around the through hole 21 are oriented toward the center (center point Mh) of the through hole 21. Here, the center point Mh refers to the depth direction of the through hole 21 and the center of the cross section of the through hole 21.
Thereby, the nonwoven fabric 10 becomes difficult to be crushed, and excellent cushioning properties can be obtained. Further, the liquid easily flows along the fiber orientation direction, and the liquid easily flows into the through holes 21 in the orientation direction, so that the liquid absorption rate is increased.

  Further, as shown in FIG. 3, the wall portion 14wX crossed by the virtual line Lwx along the first direction X in the cross section passing through the center point Mw of the cross section of the wall portion 14 passes through the center point Mw. The orientation of the fibers is as follows with the wall portion 14wY crossed by the virtual line Lwy along the second direction Y in the transverse section. For example, the orientation angle of the wall portion 14wX is 50 ° to 130 °, preferably 55 ° to 125 °, more preferably 60 ° to 120 ° when the Mw direction is 90 °. The orientation angle of the wall portion 14wY is 50 ° to 130 °, preferably 55 ° to 125 °, more preferably 60 ° to 120 ° when the Mw direction is 90 °. The orientation strength of the wall portion 14wX is 1.05 or more, more preferably 1.1 or more. The orientation strength of the wall portion 14wY is 1.05 or more, more preferably 1.1 or more. Thus, both the wall portion 14wX and the wall portion 14wY are not easily crushed by being oriented toward the center of the protruding portion, and can maintain high cushioning properties and absorption performance.

As shown in FIG. 4, a wall portion 14 having an annular structure is provided between the second projecting portion top portion 12 </ b> T and the opening portion 12 </ b> H, and the fiber density of the wall portion portion 14 </ b> H around the through hole 21 is intermediate between the wall portions 14. This is lower than the fiber density of the wall portion 14M.
The fiber density of the wall portion 14H is 2 to 100 fibers / mm ² , preferably 5 to 90 fibers / mm ² , and more preferably 10 to 80 fibers / mm ² . The fiber density of the wall portion 14M is 30 to 200 fibers / mm ² , preferably 40 to 170 fibers / mm ² , and more preferably 50 to 150 fibers / mm ² . Therefore, within the above range, the fiber density of the wall portion 14H is lower than the fiber density of the wall portion 14M.
Since the fiber density is thus different, the strength of the wall portion 14H is high and it is difficult to be crushed, so that it is possible to suppress body fluid from returning from the absorbent layer to the skin during use.
In addition, the wall part 14H shows the area | region from the edge of the through-hole 21 to 0.5 mm.

  The fiber material that can be used for the nonwoven fabric 10 of the present invention is not particularly limited. Specific examples include the following fibers. Polyolefin fibers such as polyethylene (PE) fibers and polypropylene (PP) fibers; fibers using a thermoplastic resin such as polyethylene terephthalate (PET) and polyamide alone; composite fibers having a structure such as a core-sheath type and a side-by-side type, such as A core-sheath structure fiber in which the sheath component is polyethylene or low-melting-point polypropylene is preferable, and representative examples of the core / sheath structure fiber include PET (core) and PE (sheath), PP (core) and PE (core). Sheath), fibers of core-sheath structure such as PP (core) and low melting point PP (sheath). More specifically, the constituent fibers preferably include polyolefin fibers such as polyethylene fibers and polypropylene fibers, polyethylene composite fibers, and polypropylene composite fibers. Here, the composite composition of the polyethylene composite fiber is polyethylene terephthalate and polyethylene, and the composite composition of the polypropylene composite fiber is preferably polyethylene terephthalate and low-melting polypropylene, and more specifically, PET (core). And PE (sheath), PET (core), and low melting point PP (sheath). These fibers may be used alone to form a nonwoven fabric, but may be used in combination of two or more.

Next, the dimension specification in the nonwoven fabric 10 of this embodiment is demonstrated below.
Regarding the thickness of the sheet, the total thickness when viewed from the side of the nonwoven fabric 10 is the sheet thickness TS, and the local thickness of the sheet curved in the unevenness is the layer thickness TL. The sheet thickness TS may be adjusted as appropriate depending on the application, but when used as a surface sheet for diapers, sanitary products, etc., 1 mm to 7 mm is preferable, and 1.5 mm to 5 mm is more preferable. By setting it as the range, the body fluid absorption speed at the time of use is high, the liquid return from an absorber is suppressed, and also moderate cushioning property is realizable. The layer thickness TL may be different in each part in the sheet, and may be appropriately adjusted depending on the application. When used as a top sheet for diapers, sanitary products, etc., the layer thickness TL1 of the first protrusion top 11T is preferably 0.1 mm to 3 mm, more preferably 0.4 mm to 2 mm. The preferable range of the layer thickness is the same for the layer thickness TL2 of the second protrusion top 12T around the through hole 21 and the layer thickness TL3 of the wall 14 (13). The relationship between the layer thicknesses TL1, TL2, and TL3 is preferably TL1>TL3> TL2. Thereby, in the 1st protrusion part 11, especially on the skin surface side, fiber density is low and can implement | achieve favorable skin contact. On the other hand, the second protrusion 12 has a high fiber density, is not easily crushed, and can be made of a nonwoven fabric excellent in cushioning properties and liquid absorption speed without being deformed.
What is necessary is just to adjust suitably the space | interval of the said 1st protrusion part 11 and the 2nd protrusion part 12 according to a use, and when using as surface sheets, such as a diaper and sanitary goods, 1 mm-15 mm are preferable, and 3 mm-10 mm are more preferable. The basis weight of the nonwoven fabric 10 is not particularly limited, but is preferably 15 to 50 g / ^{m 2} the average value of the entire sheet, 20 to 40 g / ^{m 2} is more preferable.

The nonwoven fabric 10 demonstrated by the said embodiment has the following effects.
The said nonwoven fabric 10 (refer said FIG. 1) has the outstanding cushioning property.
Since the nonwoven fabric 10 of this embodiment has the part which protruded not only on the single side | surface of a front and back but on both surfaces, the cushioning characteristic peculiar to the structure is expressed. For example, streak-like projections or single-sided projections will inevitably exhibit elasticity as lines or surfaces. However, according to this embodiment, the two-dimensional movement is well followed and supported by points on both sides. Has a three-dimensional cushioning. Moreover, it has the fiber orientation orientated toward the direction where the wall part 13 stands. For this reason, a firm stiffness is produced in the wall portion 13, and there is an appropriate cushioning property that prevents the fibers from being crushed in the thickness direction. Furthermore, even if the nonwoven fabric 10 is crushed due to the pressing force due to the fiber orientation of the wall portion 13, the shape restoring force is large, and the initial cushioning force is easily maintained even if the packing state and wearing are continued. That is, the first and second projecting portions 11 and 12 are not easily crushed and can be easily recovered even if deformation occurs.

The said nonwoven fabric 10 (refer said FIG. 1) is excellent in the touch.
The nonwoven fabric 10 of this embodiment has the 1st, 2nd protrusion parts 11 and 12 in a double-sided direction, and the top part 11T is rounded. Therefore, the surface on the 1st protrusion part 11 side is made into the skin surface side, and the favorable touch which a surface sheet contacts softly with respect to skin is implement | achieved. In addition, the point of contact with the pressure at the time of wearing increases and decreases in a planar shape, and the shape deformation of the entire topsheet against pressure can be suppressed while improving the touch, and shape restoration from pressure deformation can also be achieved Easy to do. There also exists an effect | action resulting from said favorable cushioning property, and a unique favorable touch is obtained with the dynamic effect | action by a point contact. Moreover, the point contact mentioned above has an effect also when excretion etc. are received, and the smooth touch is implement | achieved. Complementing this smooth touch (absorbing effect), since the fiber is oriented in the direction in which the wall portion 13 stands up, the liquid is smoothened by the fibers oriented in the thickness direction of the wall portion 13. Through the through-holes 21, the fibers are quickly transferred to the absorbent body disposed on the lower surface of the nonwoven fabric 10, and the liquid orientation of the wall portion 13 reduces liquid return, thereby realizing a smooth touch. Further, the nonwoven fabric 10 itself is excellent in air permeability by maintaining the above-described structure, and helps prevent fogging by the effect of point contact.

The said nonwoven fabric 10 (refer said FIG. 1) is excellent in the excretion capture property.
In the nonwoven fabric 10 of this embodiment, since it has internal space 11K and 12K inside each of the 1st, 2nd protrusion parts 11 and 12 which protrude on both surfaces, it is various according to the physical property of excretion liquid and excrement. These can be captured and dealt with in various forms. For example, when the first surface side Z1 of the nonwoven fabric 10 is described as the skin surface side, if it is excrement having high viscosity and low permeability, the excrement is temporarily stored in the internal space 12K without passing through the surface sheet of the nonwoven fabric 10. The water and a part thereof are absorbed by the absorber (not shown) through the through hole 21. On the other hand, if the excretory liquid has a low viscosity and easily permeates, it passes through the through-hole 21 and the surface sheet of the nonwoven fabric 10 and is then captured in the internal space 11K. In any of these cases, the portion that first hits the skin surface is the first protruding portion top portion 11T, and the captured excretory fluid or excrement is made difficult to come into contact with the skin. As a result, after the excretion of urine, feces, menstrual blood, and spillage, a very good and smooth feeling can be sustained widely.

  Next, a preferred planar arrangement example of the first and second projecting portions 11 and 12 will be described with reference to FIG.

  As shown in FIG. 5, the example of arrangement | positioning is the 1st protrusion part 11 which protruded on the 1st surface side Z1 (paper surface upper side) of the side which planarly viewed the sheet-like nonwoven fabric, and the 1st surface side Z1 and the other side. The second projecting portion 12 projecting to the second surface side Z2 (downward on the paper surface) alternates in each of the first direction X and the second direction Y as different directions intersecting in plan view over the entire surface of the nonwoven fabric 10. Are arranged continuously. Accordingly, when viewed in one direction, the first projecting portions 11 and the second projecting portions 12 project alternately in opposite directions with respect to the sheet surface. The crossing angle between the first direction X and the second direction Y is preferably 30 ° or more and 90 ° (orthogonal) or less, for example, 90 °. The same number of second projecting portions 12 as the first projecting portions 11 projecting on the first surface side Z1 are arranged so as to project on the second surface side Z2. The first ridge 15 is formed between the first protrusions 11 adjacent to each other. As described with reference to FIG. 1, the internal space 11 </ b> K is held in the first protrusion 11, and the internal space 12 </ b> K is held in the second protrusion 12. Moreover, although not shown in figure, seeing from the 2nd surface side Z2, between the 2nd protrusion parts 12 adjacent to each becomes a 1st ridge part.

  The internal spaces 11K and 12K are separated from each other by the wall 13 (14) with the first ridge 15 as a boundary, and are configured as spaces that are not substantially continuous. This “ridge portion” refers to a boundary line between two surfaces having an inclination and a convex section, and in this case, an “intersection” (boundary line) between the surfaces of the internal space 12K of the adjacent second protrusions 12. . In other words, along a ridge line that passes between the second protrusions 12 so as to surround the second protrusions 12 from the adjacent first protrusions 11 via the second protrusions 12 to another first protrusion 11B. Refers to the part. The “ridge line” is a line obtained by continuously connecting the highest positions in the vertical longitudinal section viewed continuously with respect to the line connecting the top portions 11T of the nearest first projecting portion 11. Say.

  In the nonwoven fabric 10 of the above-described arrangement example, the first protrusions 11 are connected via the first ridges 15, and the first protrusions 11 are parallel to the first ridges 15 while the first protrusions 11 are connected. It is connected through. Further, the second protrusions 12 are connected in parallel between the series of the first protrusions 11 and the series of other first protrusions 11. Since it is such an arrangement | positioning form, it has a capture | acquisition space between the 1st protrusion parts 11 series. In addition, the trapping space becomes a liquid diffusion path, and the series of the first protrusions 11 prevents the liquid from leaking sideways.

  In the above arrangement example, when the crossing angle between the first direction X and the second direction Y is 60 °, the first protrusions 11 and the second protrusions 12 are adjacent to each other. However, as long as a continuous sheet state is formed as a whole, the arrangement of such a form is also different in the first and second directions X and Y as the different directions intersecting in plan view. Since the second protrusions 11 and 12 are alternately and continuously arranged, it is included in the meaning that the first protrusions 11 and the second protrusions 12 are arranged “alternately”.

  As described above, the first protrusion 11 and the second protrusion 12 arranged in the first direction (X direction) and the second direction (Y direction) in plan view are in a state where the whole is continuous with a curved surface, The nonwoven fabric 10 is comprised. In addition, the arrangement | sequence form of the said 1st protrusion part 11 and the 2nd protrusion part 12 is not limited above, What is necessary is just a form which can be arrange | positioned by the arrangement | sequence which can be continued. For example, the arrangement may be such that six second projecting portions 12 are arranged at the apexes of the hexagon with the first projecting portion 11 as the center, and the pattern extends in the plane. In addition, four second protrusions 12 are arranged at the apexes of the square with the first protrusion 11 as the center, and further, the second protrusions 12 are arranged at the centers between the apexes, for a total of eight second protrusions. 12 may be arranged, and the pattern may extend in the plane.

Next, a preferred embodiment of the method for producing the nonwoven fabric 10 of the present invention will be described below with reference to FIG.
The manufacturing method of the nonwoven fabric 10 according to the above-described embodiment may be a method generally used for this type of product as appropriate. At this time, the support 30 having the configuration shown in FIG. 6A is used as a support for shaping the web. The support 30 has a plurality of protrusions 31 corresponding to positions where the holes 32 are arranged corresponding to the positions where the first protrusions 11 are shaped and the second protrusions 12 are shaped. . The tip shape of the protrusion 31 is made at an acute angle. For this reason, when air is strongly blown onto the support 30, the first protrusion 11 is formed between the protrusions 31, and the through hole 21 is formed at the top of the second protrusion 12 formed between the protrusions 31. .

An example of this production method is as follows.
In the web apparatus that supplies the fiber web 20 before fusion to a shaping apparatus from a card machine (not shown) so as to have a predetermined thickness, the fiber web 20 is first fixed to the support 30. Next, warm air is blown onto the fiber web 20 on the support 30 to shape the fiber web 20. Temperature of hot air at this time, considering the general fiber materials used for this type of product, it is necessary that low 5 to 50 ° C. with respect to the melting point of the thermoplastic fiber constituting the fiber web (the (See FIG. 6 (1)). In the drawing, a two-dot chain line indicates a shaped fiber web 20 in which a first protrusion 11 and a second protrusion 12 are formed.

  Next, as shown in FIG. 6 (2), each fiber is fused by blowing hot air (hereinafter referred to as hot air) of air at a temperature at which each fiber can be appropriately fused. The temperature of the hot air at this time is preferably 0 to 70 ° C. higher than the melting point of the thermoplastic fiber constituting the fiber web 20 in consideration of a general fiber material used for this type of product, and 5 to 50 More preferably, the temperature is higher.

  Examples of the thermoplastic fiber include, as described above, polyolefins such as polypropylene and polyethylene, polyesters, polyamides such as nylon 6 and nylon 66, polyacrylonitriles, and the like, or a core-sheath type composed of two or more of these. And side-by-side type composite fibers. When a composite fiber containing a low melting point component and a high melting point component is used as the thermoplastic fiber, the temperature of the hot air blown onto the fiber web 20 is preferably equal to or higher than the melting point of the low melting point component and lower than the melting point of the high melting point component. . The temperature of the hot air blown onto the fiber web 20 is more preferably a temperature not lower than the melting point of the low melting point component and 10 ° C. lower than the melting point of the high melting point component. It is more preferable that the temperature is lower by at least ° C.

  The fiber web 20 preferably contains 30 to 100% by mass of thermoplastic fibers, and more preferably 40 to 80% by mass. The fiber web 20 may include fibers that do not inherently have heat-fusibility (for example, natural fibers such as cotton and pulp, rayon, and acetate fibers).

The wind speed of the warm air that shapes the fiber web 20 is 60 to 80 m / s, more preferably 65 to 75 m / s, from the viewpoints of formability and texture. It is preferable that the wind speed is within the above range because the through-hole 21 is formed in the portion that is protruded by the protrusion 31 and the three-dimensional effect is sufficient, and the effects of air permeability and excrement capture are sufficiently exhibited. Further, it is preferable because the fiber density and orientation are in a predetermined range, the body fluid absorption rate is increased, and the liquid return amount is reduced. If the wind speed is too lower than the lower limit value, the through-hole 21 is not formed. On the other hand, if the wind speed is too fast, the diameter of the through-hole becomes too large, and the fiber density at the edge portion (14H) of the through-hole 21 increases with the selected fibers. Is in a direction perpendicular to the center direction of the through-hole 21 (MD direction), the liquid flow during absorption becomes poor. Moreover, it is preferable that the wind speed is in the above range because the compression resistance is well maintained, the touch is good, and the effects of air permeability and excretion capture can be sufficiently exhibited. In consideration of continuous production, there may be mentioned a mode in which the support 30 is made of a conveyor type or a drum type, and the typed nonwoven fabric 10 being conveyed is wound up by a roll. In this way, the nonwoven fabric 10 of the present invention is obtained. In addition, although MD and CD may be turned to any direction about the nonwoven fabric 10 of this embodiment, when it says in the model figure shown in the said FIG. 5, it is preferable to make drawing vertical direction MD.
The MD is also referred to as a machine direction, which is a fiber web feeding direction when manufacturing a nonwoven fabric, and is an abbreviation for “Machine Direction”. The CD is a direction orthogonal to the MD and is an abbreviation of “Cross Direction”.

Next, as an example in which the nonwoven fabric 10 of the present invention is applied to an absorbent article, an application example of the diaper 100 to the absorbent main body 4 will be described with reference to FIG.
As shown in FIG. 7, the disposable diaper which applied the nonwoven fabric 10 of this invention to the surface sheet 1 is partially cut away, and is a perspective view which shows typically. The diaper shown in the figure is a tape-type disposable diaper for infants, and is shown in a state where a diaper developed in a plane is bent slightly and viewed from the inside (skin contact surface side).

  The disposable diaper 100 includes a liquid-permeable top sheet 1 disposed on the skin contact surface side, a liquid-impermeable back sheet 2 disposed on the non-skin contact surface side, and a gap between them. And an absorber 3. The nonwoven fabric 10 of the said embodiment is applied to the surface sheet 1, and the 1st protrusion part 11 side is made into the skin contact surface. An absorber 3 is interposed between the back sheet 2 and the top sheet 1. The back sheet 2 is in an unfolded state, and both side edges thereof have a shape confined to the inside in the longitudinal central portion C. Even if the back sheet 2 is composed of a single sheet, it is composed of a plurality of sheets. Also good. In this example, a side leakage prevention gather 7 formed by the side seats 5 is provided, whereby side leakage of liquid or the like in the hip joint portion due to movement of the infant can be effectively prevented. In the diaper of this embodiment, a functional structure part, a sheet material, etc. may be provided. In addition, in FIG. 7, the arrangement | positioning relationship and boundary of each member are not illustrated strictly, and if it is set as the general form of this kind of diaper, the structure will not be specifically limited.

  The diaper is shown as a tape type, and a fastening tape 6 is provided on the flap portion on the back side R. The fastening tape 6 can be attached to a tape application part (not shown) provided in the flap part on the ventral side F, and the diaper can be attached and fixed. At this time, the center part C of the diaper is gently bent inward so that the absorbent body 3 is worn along the baby's buttocks and lower abdomen. As a result, excreta is absorbed and held in the absorber 3 accurately. By using in such a form, especially the non-woven fabric 10 is applied as the top sheet 1, it shows a good touch, cushioning properties, and excretion capturing properties. In particular, the excretion capture ability can achieve extremely high performance that cannot be achieved by the conventional surface sheet of linear protrusions or those with a small hole, such as diarrhea or loose stool on an infant's skin. It can protect suitably from rough skin by etc.

  The nonwoven fabric 10 of the present invention can be used for various other applications. For example, it can be suitably used as a surface sheet for absorbent articles such as the disposable diapers described above, sanitary napkins, panty liners, urine absorption pads and the like. Furthermore, since the both surfaces of the nonwoven fabric 10 are excellent in air permeability, liquid diffusibility, deformation characteristics at the time of pressing force, etc. due to the concavo-convex structure, between the surface sheet such as diapers and sanitary products and the absorbent body It can also be used as a sub-layer interposed between. In addition, the form utilized as a surface sheet, gathers, an exterior sheet, and a wing of an absorbent article is also mentioned. Furthermore, the form utilized as a wiping wipe sheet | seat, a cleaning sheet | seat, and a filter is also mentioned.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is limited and interpreted by these Examples.

[Example 1-4, Reference example 1-2]
In Example 1, a 2.4 dtex × 51 mm core-sheath composite fiber having a core of polyethylene terephthalate and a sheath of polyethylene was supplied from the card machine to the shaping device so that the basis weight was 30 g / m ² . In the shaping apparatus, the fiber web was fixed on a pedestal having a large number of protrusions and air permeability. The MD pitch 8 mm and the CD pitch 5 mm in plan view of the protrusions 31 of the support 30 were set.
Next, hot air (temperature 130 ° C., wind speed 60 m / s) is blown onto the fiber web 20 on the support 30 and shaped, and the fiber web 20 is shaped along the protrusions 31 on the support 30. The core-sheath structure fibers were fused by switching to hot air having a temperature of 145 ° C. and a wind speed of 5 m / s. The nonwoven fabric 10 thus formed by heat fusion was taken out and used as a nonwoven fabric test body of Example 1. The basis weight of the nonwoven fabric 10 of Example 1 was 30 g / m ² , and the thickness T was 4.2 mm.
In Example 2, the nonwoven fabric 10 was produced under the same conditions as in Example 1 except that the wind speed of hot air as the shaping condition was 65 m / s.
In Example 3, the nonwoven fabric 10 was produced under the same conditions as in Example 1 except that the hot air speed as the shaping condition was set to 70 m / s.
In Example 4, the nonwoven fabric 10 was produced under the same conditions as in Example 1 except that the wind speed of hot air as the shaping condition was 75 m / s.

The reference example 1 produced the nonwoven fabric 10 on the same conditions as the said Example 1 except the wind speed of the hot air as shaping conditions having been 47.5 m / s. In Reference Example 1, the thickness of the nonwoven fabric was 3.40 mm, and no through hole was opened in the second protrusion 12.
The reference example 2 produced the nonwoven fabric 10 on the same conditions as the said Example 1 except the wind speed of the hot air as shaping conditions having been 50 m / s. In Reference Example 2, the nonwoven fabric had a thickness of 3.50 mm, and no through hole was opened in the second protrusion 12.

[Comparative Example 1-3]
In Comparative Example 1, a nonwoven fabric test specimen was produced by the method described in Example 1 of JP-A-2008-25081 (Patent Document 3). Comparative Example 1 was a non-woven fabric having a streak-like uneven shape and an opening, and the heights of the streak-like convex portions were all the same and were 1.3 mm.
In Comparative Example 2, a nonwoven fabric test specimen was produced by the method described in Japanese Patent Laid-Open No. 03-137258 (Patent Document 1).
In Comparative Example 3, a nonwoven fabric test specimen was produced by the method described in JP-A-08-246321 (Patent Document 2). Comparative Example 3 was a non-woven fabric having convex portions and apertures, and the heights of the convex portions were all the same and were 1.2 mm.

  Next, the evaluation method will be described. The following measurement test was performed using a nonwoven fabric test body or a diaper.

<Measurement of height>
The cut surface of the non-woven fabric specimen is enlarged to a size (10 to 100 times) that can be measured by a digital microscope VHX-1000 manufactured by Keyence, and the first protrusion 11 shown in FIG. Measure the height TS. The measurement was performed 5 times, and the average was taken as the height TS (mm) of the first protrusion 11 of the sample.

<Measurement of fiber orientation (orientation angle, orientation strength)>
Using a scanning electron microscope JCM-5100 (trade name) manufactured by JEOL Ltd., the sample is allowed to stand so that the z-axis direction in FIG. Images taken from the direction (adjusted to a magnification capable of measuring 10 or more fibers to be measured; 100 to 300 times) were printed, and the fibers were traced on a transparent PET sheet. The said image was taken in in the personal computer and the said image was binarized using the NexusNewQube [tradename] (stand-alone version) image processing software. Next, the binarized image was subjected to Fourier transform using Fiber Orientation Analysis 8.13 Single software (trade name), which is a fiber orientation analysis program, to obtain a power spectrum, and from an elliptical distribution map, an orientation angle was obtained. And the orientation strength was obtained.
The orientation angle indicates the angle at which the fibers are most oriented, and the orientation strength indicates the strength at the orientation angle. In the measurement of the peripheral part of the through hole 21 and the middle part of the wall part, the closer the orientation angle is to 90 °, the more the fiber is oriented in the central direction of the through hole 21, and 60 to 120 °. It is determined that the fibers are oriented in the center direction of the through hole 21.
Moreover, it represents that the direction of a fiber has gathered, so that the value of orientation strength is large. The case where the orientation strength is 1.05 or more is assumed to be oriented.
Measurement was performed at three locations, and the average was taken as the orientation angle and orientation strength of the sample.

The fiber orientation described above is a concept consisting of the orientation angle and orientation strength of the fiber.
The fiber orientation angle is a concept that indicates in which direction a plurality of fibers having various directions are oriented as a whole, and the shape of the fiber aggregate is quantified. The orientation strength of the fiber is a concept indicating the amount of fibers exhibiting an orientation angle. The orientation strength is less than 1.05 and is hardly oriented, and it can be said that the orientation strength is 1.05 or more. However, in this embodiment, the fiber orientation changes depending on the part. That is, the orientation strength is changed during the transition from a part having a certain orientation angle to a part having a different orientation angle (while the fiber is changing from a state where the orientation strength is strong in one direction to a part showing a strong strength in a different orientation). It has various states such as a weak state and a high state due to reorientation. Therefore, it is preferable that the orientation angle of the fiber is changed between the part showing a strong orientation angle and the part showing a strong orientation angle in another direction even if the orientation strength of the fiber is weak, and the orientation strength is high. Is more preferable. As an example of the orientation strength in this embodiment, the orientation angle is preferably from 50 to 130 °, more preferably from 60 to 120 ° with respect to the curved surface structure around the through-hole 21, and the orientation strength is 1. 05 or more is preferable, More preferably, it is 1.10 or more. The orientation angle with respect to the curved surface structure of the wall portion 14 of the second protrusion 12 is preferably 50 to 130 °, more preferably 60 to 120 °, and the orientation strength is preferably 1.05 or more, more preferably 1. .20 or more.
Since the orientation direction of the fiber of each wall part 14 is a direction which goes to the center of each through-hole 21, cushioning property is expressed. Moreover, when the nonwoven fabric 10 is used as the top sheet 1, there is a difference in the fiber orientation of each wall portion 14, and the high first projecting portion 11A has a higher orientation, so that the main portion as under a low load is used. Even when the high first protrusion 11A is in contact with the skin, the nonwoven fabric has sufficient compression resistance and prevents the nonwoven fabric from being crushed. As a result, a sufficient capture space can be ensured, and the effect of reducing the skin contact area, high air permeability, a large amount of liquid, solid content, highly viscous liquid, etc. can be sufficiently captured and the effect of suppressing leakage can be sufficiently exhibited.

<Measurement of fiber density>
The cut surface of the nonwoven fabric portion was magnified using a scanning electron microscope (adjusted to a magnification (150 to 500 times) at which the fiber cross section can be measured about 30 to 60 times (100 times for this example)), and a constant area The cross-sectional area of the fibers cut by the cut surface was counted, and the center of observation was the middle point of the thickness of the first protrusion top 11T and the second protrusion top 12T. This was converted to the number of cross-sections of fibers per ^2. This was the fiber density (lines / mm ² ) Measurement was performed at three locations and averaged to obtain the fiber density of the sample. JCM-5100 (trade name) manufactured by Electronics Co., Ltd. was used.

<Measurement of absorption time under pressure>
The surface sheet was removed from a commercially available baby diaper (trade name “Merry's Sarah Air-Through M size”) manufactured by Kao Corporation. Instead, a non-woven fabric test piece cut into 100 × 250 mm was laminated, and its periphery was fixed and evaluated. I got a baby diaper. A load having a pressure of 20 g / cm ² was evenly applied on the nonwoven fabric test specimen, and a cylinder with a cross-sectional area of 1000 mm ² placed at the approximate center of the test specimen was applied, and artificial urine was injected therefrom. As the artificial urine, physiological saline was used, and the artificial urine was injected three times by 40 g every 10 minutes, and the time (seconds) to be absorbed was measured.

<Measurement of return of pressurized liquid>
The surface sheet is removed from the commercially available baby diaper (trade name “Merry's Sarasara Air-Through M size”) of Kao Corporation. Instead, the non-woven fabric test specimen 1 cut out to 100 × 250 mm is laminated, and its periphery is fixed. A baby diaper for evaluation was obtained. A load having a pressure of 20 g / cm ² was evenly applied on the nonwoven fabric test specimen, and a cylinder with a cross-sectional area of 1000 mm ² placed at the approximate center of the test specimen was applied, and artificial urine was injected therefrom. As the artificial urine, physiological saline is used, and after 40 g of artificial urine is injected three times every 10 minutes, the load is removed, and a filter paper to which a load of 4.9 kPa is applied is applied to the nonwoven fabric specimen. After placing and leaving for 2 minutes, the mass change of the filter paper was defined as the liquid return amount (g).

  Table 1 shows the measurement results and evaluation results for each of the above evaluation items.

As is clear from the evaluation results shown in Table 1, in the nonwoven fabric 10 (Example 1-4) according to the preferred embodiment of the present invention, the through holes 21 are arranged in the top portion 12T of the second protruding portion 12. Therefore, the absorption time under pressure is 59 seconds to 74 seconds, and the return amount under pressure is 0.31 g to 0.48 g, which is very small. It has the excellent effect of being friendly to the environment. Further, regarding the orientation, the orientation angle of the MD direction center point Mh (center axis) of the through hole 21 and the wall portion 14hX which is the edge intersection of the through hole 21 is 64 ° to 96 °, and the orientation strength is 1.07. As described above, the orientation angle of the CD direction center Mh (central axis) of the through hole 21 and the wall 14hY which is the edge intersection of the through hole 21 is 57 ° to 100 °, and the orientation strength is 1.08 or more. Therefore, the supplied liquid easily flows along the fiber orientation direction and easily flows into the through-hole 21, so that the effect of increasing the liquid absorption rate can be obtained.
Further, the orientation angle in the MD direction of the wall portion 14 is 81 ° to 102 °, the orientation strength is 1.16 or more, the orientation angle in the CD direction is 55 ° to 101 °, and the orientation strength is 1.12. Since it is above, since it becomes easy for a liquid to flow along the wall part 14 and to the through-hole 21 direction, the effect that a liquid absorption speed becomes quick is acquired.

In Reference Example 1, the through hole 21 is not formed, but the MD orientation angle is 93.5 °, the orientation strength is 1.47, the CD orientation angle is 52.6 °, and the orientation strength is 1.23. Therefore, the absorption time is short and the liquid return amount is relatively small.
In Reference Example 2, the through hole 21 is not formed, but the MD orientation angle is 91.9 °, the orientation strength is 1.33, the CD orientation angle is 94.4 °, and the orientation strength is 1.14. Therefore, the absorption time is short and the liquid return amount is relatively small.

In Comparative Example 1, the MD orientation center point (center axis) of the opening and the wall portion which is the edge intersection of the opening have an orientation angle of 7.9 °, the fiber orientation is 1.72, Since the orientation angle of the center point (center axis) in the CD direction and the wall portion which is the edge intersection of the aperture is 175.6 ° and the orientation strength is 2.36, the liquid supplied around the aperture is a fiber. Since it flows along the orientation direction, it is difficult to flow into the aperture, so that the liquid absorption rate is slow.
Further, since the orientation angle in the MD direction of the wall portion 14 is 9.1 °, the orientation strength is 1.27, the orientation angle in the CD direction is 86 °, and the orientation strength is 1.3, the wall The liquid flows in the opening direction along the part.
In Comparative Example 2, the orientation angle of the center of the hole in the MD direction (center axis) and the wall portion which is the edge intersection of the hole is 162.8 °, the fiber orientation is 2.82, Since the orientation angle of the center point (center axis) in the CD direction and the wall portion which is the edge intersection of the aperture is 168.6 ° and the orientation strength is 2.31, the liquid supplied around the aperture is a fiber. Since it flows along the orientation direction, it is difficult to flow into the aperture, so that the liquid absorption rate is slow.
Further, since the orientation angle in the MD direction of the wall portion 14 is 86 °, the orientation strength is 1.01, the orientation angle in the CD direction is 19 °, and the orientation strength is 1.17, It is difficult for the liquid to flow in the opening direction.
In Comparative Example 3, the orientation angle of the center of the hole in the MD direction (center axis) and the wall at the edge intersection of the opening is 162.8 °, the fiber orientation is 1.53, Since the orientation angle of the wall portion which is the intersection of the CD direction center point (center axis) and the edge of the opening is 2.1 ° and the orientation strength is 2.23, the liquid supplied around the opening is a fiber. Since it flows along the orientation direction, it is difficult to flow into the aperture, so that the liquid absorption rate is slow.
Further, since the orientation angle in the MD direction of the wall portion 14 is 10 °, the orientation strength is 1.14, the orientation angle in the CD direction is 39 °, and the orientation strength is 1.19, It is difficult for the liquid to flow in the opening direction.

DESCRIPTION OF SYMBOLS 1 Top sheet 2 Back sheet 3 Absorbent body 10 Nonwoven fabric 11 1st protrusion part 11T 1st protrusion part top part 11K Internal space 11H Opening part 12 2nd protrusion part 12T 2nd protrusion part top part 12K Internal space 12H Opening part 13,14 Wall part 15 1st edge part 21 Through-hole 100 Diaper Z1 1st surface side Z2 2nd surface side

Claims (8)

A first projecting portion projecting to the first surface side of the sheet-like nonwoven fabric in plan view, and a second projecting portion projecting to the second surface side opposite to the first surface side, The first and second protrusions are alternately and continuously arranged in different directions intersecting in plan view of the nonwoven fabric,
Having a through hole at the top of the plurality of second protrusions;
A nonwoven fabric in which fibers around the through hole are oriented toward the center of the through hole.   The nonwoven fabric according to claim 1, wherein the fibers constituting the wall portion of the second protrusion have a radial fiber orientation toward the top of the second protrusion. A wall portion of an annular structure between the top of the second protrusion and the opening;
The nonwoven fabric according to claim 1 or 2, wherein a fiber density of a wall portion around the through hole is lower than a fiber density of a wall portion of the wall middle portion.   The fiber density of the wall portion around the through hole is 2 / mm. ² More than 100 / mm ² The fiber density of the wall portion in the middle portion of the wall portion is 30 fibers / mm. ² More than 200 / mm ² The nonwoven fabric according to claim 3, wherein: The nonwoven fabric according to any one of claims 1 to 4, wherein the fibers constituting the wall of the first protrusion have a radial fiber orientation toward the top of the first protrusion. A wall portion of an annular structure between the top of the second protrusion and the opening;
A wall portion traversed by an imaginary line along a first direction which is one of the different directions in the cross section passing through a center point of the cross section of the wall portion, and the wall section in the cross section passing through the center point. in a wall portion where the virtual line intersects along a second direction different from the a 1 direction different directions the first direction, from the claims 1 that have a orientation towards the center of the second protrusion 5 The nonwoven fabric of any one of these. The first protrusion adjacent to, each have connected by first ridge, the second protruding portions adjacent to the one each from and has claim 1 connected by the second edge portion 6 1 The nonwoven fabric according to item.   The relationship between the layer thickness TL1 of the top of the first protrusion, the layer thickness TL2 of the top of the second protrusion around the through hole, and the layer thickness TL3 of the wall of the second protrusion is TL1> TL3> TL2. The nonwoven fabric according to any one of claims 1 to 7.

Images