JPH0791764B2 - Nonwoven fabric, method for producing the same, and absorbent article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a nonwoven fabric, a method for producing the same, and an absorbent article,
More specifically, the present invention relates to a nonwoven fabric having irregularities suitable as a surface material for absorbent articles such as disposable diapers and sanitary napkins, a method for producing the same, and an absorbent article using the nonwoven material as a surface material.

[Conventional technology]

One of the problems of absorbent articles such as paper diapers and sanitary napkins is to suppress or prevent leakage of body fluids such as urine, loose stools, and menstrual blood from the absorbent articles. For that purpose, the members constituting the absorbent article, that is, the surface material, the absorber, the back surface material, and the like, are each creatively devised to suppress or prevent liquid leakage.

In general, a non-woven fabric is often used for the surface material, and the non-woven fabric is often formed of a hydrophilic thermoplastic fiber in order to improve the absorbability of body fluid. Also,
In order to prevent exudation and leakage of body fluids, attempts have been made to make the side parts or the peripheral parts of the nonwoven fabric, which is the surface material of sanitary goods, hydrophobic.

On the other hand, highly viscous body fluids such as loose stools and highly viscous menstrual blood have poor permeability in ordinary non-woven fabrics, and flow through the non-woven fabric surface until they are absorbed by the internal absorbent body to stain clothes and sometimes skin irritation. It may cause discomfort.

Conventionally, as measures against these, for example, a method of perforating a non-woven fabric with a pin, a needle or the like, a method of interlacing a web with a high-speed water flow to form a perforated shape or a mesh shape (Japanese Patent Publication No. 62-62175).
Japanese Patent Laid-Open No. 62-28219), and a method of reducing the basis weight of a non-woven fabric or increasing the distance between fibers with thick denier fibers has been proposed.

[Problems to be Solved by the Invention]

However, the conventional nonwoven fabrics and the manufacturing methods thereof have the following problems, respectively.

That is, the non-woven fabric perforated with a pin, a needle, etc., has a poor feel on the surface because of the formation of protrusions around the perforations on the surface, and also lacks the morphological stability of the perforation. , Fluff is liable to occur, and bulkiness cannot be obtained unless the basis weight is increased. In addition, the fiber treatment agent may fall off due to a high-speed water flow, and a fiber composed of thermoplastic fibers may become hydrophobic. There was Also enough confounding,
In order to provide the perforations, there is a problem that the processing speed cannot be increased, the water flow is scattered around the manufacturing apparatus, which is not preferable in the working environment, and rust is generated in the manufacturing apparatus. Furthermore, in the case of a mesh non-woven fabric, the return of body fluid absorbed by the absorber is large, and when used as a surface material,
There was also a problem that a dry feeling could not be obtained.

In short, conventional non-woven fabric, when used as a surface material,
Although permeability to excrements such as body fluids with high viscosity is recognized to some extent, they are not always sufficient as liquid permeability, and in addition, the ability to suppress body fluid return, which is required as a surface material for absorbent articles. However, properties such as bulkiness and texture such as touch were not always satisfactory.

Therefore, the object of the present invention, when used as a surface material of an absorbent article, is to ensure that permeates such as body fluids having high viscosity are permeated and that their leakage is suppressed or prevented, and that they are required as a surface material. It is an object of the present invention to provide a comprehensively excellent non-woven fabric having various properties as well as a method for producing the same and an absorbent article utilizing the various properties by using the non-woven fabric as a surface material.

[Means for Solving the Problems]

The present inventors have conducted various studies on a nonwoven fabric having a form capable of preventing the flow of a highly viscous liquid and having excellent permeability and a method for producing the same, and as a result, after forming irregularities on the fiber web by a specific means, the fiber web was formed. It was found that the above object can be achieved by heating and fusing the thermoplastic fiber contained in the.

That is, the present invention is based on the above findings,
In a nonwoven fabric obtained by melting and integrating thermoplastic fibers of a fibrous web containing thermoplastic fibers, the nonwoven fabric is
It has a central portion and both end portions adjacent to the central portion, the central portion is formed from a convex portion and a concave portion dispersed throughout and the fiber aggregation density of the concave portion is more than the fiber aggregation density of the convex portion. Further, the present invention provides a non-woven fabric characterized by having a low fiber density at both ends.

Further, the present invention is an absorbent article comprising a surface material that comes into contact with skin and an absorbent body covered with the surface material, wherein the surface material is formed of the non-woven fabric in an absorbent article that absorbs excrements such as body fluids. An absorbent article characterized by the above is provided.

Further, the present invention, as a manufacturing method suitable for manufacturing the nonwoven fabric, a fiber web containing a thermoplastic fiber is placed on an air-permeable conveyor having irregularities, and the fiber web is conveyed in a placed state. In the meantime, a gas is jetted discontinuously on the surface of the fibrous web in the width direction, and the fibrous web is made to follow the concave portion of the air-permeable conveyor and the gas is jetted only on the uneven portion of the fibrous web. The present invention also provides a method for producing the above-mentioned non-woven fabric, in which the fibrous web is heated and the thermoplastic fibers are fused and integrated after the formation.

[Action]

According to the nonwoven fabric of the present invention, the highly viscous liquid does not permeate through the central concave portion to flow on the surface, and the liquid can be prevented from returning.

In addition, according to the absorbent article of the present invention, while being in contact with the convex portion of the central portion where the fiber assembly density is high when it is worn, the viscous loose stool and body fluid such as menstrual blood have a low central portion of the fiber assembly density. It is possible to allow the absorbent body to permeate through the recessed portion and absorb the bodily fluid, and to prevent the absorbed body fluid from returning to the central portion and both end portions.

Further, according to the method for producing a nonwoven fabric of the present invention, while conveying a fiber web containing a thermoplastic fiber by a breathable conveyor having unevenness in a state of being placed, a gas discontinuously in the width direction on the surface thereof. By spraying, a concavo-convex part is formed in the gas injection part of the fibrous web, and a flat part is formed in the gas non-injection part. By heating the thermoplastic fiber, the concavo-convex part is retained in the width direction. It is possible to form a non-woven fabric having the unevenness in the central portion by fusion bonding of the thermoplastic fibers in a state of having the formed portion and the portions having the flat portions on both sides of the uneven portion.

〔Example〕

The present invention will be described below based on the embodiments shown in FIGS. In the figure, FIG. 1 is a partial perspective view conceptually showing one embodiment of the nonwoven fabric of the present invention, and FIG. 2 is II-II of FIG.
FIG. 3 is a cross-sectional view taken along the line, FIG. 3 is a perspective view showing a nonwoven fabric manufacturing apparatus that can be suitably used when carrying out the nonwoven fabric manufacturing method of the present invention, and FIG. 4 is an injection duct of the manufacturing apparatus shown in FIG. It is a partial perspective view which expands and shows the state which forms an uneven | corrugated shaped part in a nonwoven fabric.

The nonwoven fabric 10 of the present embodiment is formed by melting and integrating thermoplastic fibers of a fibrous web containing thermoplastic fibers, and as shown conceptually in FIG. It has both ends 12, 12 adjacent to each other.

Thus, the central portion 11 is formed of the convex portion 11A and the concave portion 11B dispersed throughout. The concave portion 11B has a first
Although it is expressed as a state where the holes are completely opened in FIGS. 2 and 3, originally, the fibrous web is diffused into the convex portions 11A around the fibrous web to form a low fiber aggregate density. In other words, the convex portion 11A surrounding the concave portion 11B has a higher fiber aggregate density, and as a result, the fiber aggregate density of the concave portion 11B is lower than that of the convex portion 11A. In addition, it is preferable that the fiber assembly density in the concave portion 11B becomes low as described above, and that the concave portion 11B is substantially open. The convex portions 11A and the concave portions 11B are preferably arranged alternately and regularly as shown in FIG. 1, and the nonwoven fabric 10 is formed by regularly dispersing the irregularities in this manner. The appearance quality can be improved. Further, the preferable pitch of the unevenness is 3 to 20 mm. If the pitch is less than 3 mm, the unevenness is too small and the bulkiness is deteriorated. On the contrary, if the pitch exceeds 20 mm, the unevenness is too large and only the appearance is good. However, the pitch of the concave portions 11B that function as absorption holes for the highly viscous liquid becomes large, and the permeability of the highly viscous liquid decreases. Further, the hole diameter of the open hole portion in terms of a perfect circle is preferably φ2 to φ6 mm, and the bottom surface of the concave portion 11B and the convex portion 1
The height difference h from the bottom surface of 1A is characterized by h> 0, and h> 0.5 mm is more preferable.

On the other hand, the both end portions 12 and 12 are not formed with the convex portion 11A and the concave portion 11B, respectively, and are formed substantially flat, the fiber aggregate density is formed substantially uniform, and the touch is improved. ing.

Thus, the non-woven fabric 10 of this embodiment preferably has a basis weight of 9 to 40 g / m ² , and more preferably 15 to 30 g / m ² . When the basis weight is low, the bulkiness is low, the feeling of unevenness is inferior, and the liquid returning property is deteriorated. On the contrary, even if the basis weight is increased more than necessary, there is a cost disadvantage.

Further, the fiber aggregate density of the convex portion 11A and the concave portion 11B,
With the middle of the top of the convex portion 11A and the bottom of the concave portion 11B of the nonwoven fabric 10 as a boundary, the fibrous web in the upper portion from the middle is attributed to the convex portion 11A, and the fibrous web in the lower portion from the middle is concave. Assuming that the fiber web belongs to the portion 11B, the fiber assembly density of the convex portion 11A is 1 × 10 ⁻⁵ to 8
× 10 ^-5 g / mm ² , and the fiber assembly density of the concave portion 11B is
It is preferably 0 to 2 × 10 ⁻⁵ g / mm ² . Here, the fiber aggregate density is defined by the following formula, and means the average basis weight in a minute area.

As the thermoplastic fiber forming the fibrous web, for example, polyethylene terephthalate (melting point 255
℃), polybutylene terephthalate (melting point 215 ℃), polypropylene (melting point 165 ℃), nylon-6 (melting point 220)
C.), nylon-66 (melting point 260.degree. C.), polyethylene (melting point 130.degree. C.), and fibers made of modified polymers thereof. Further, the fibrous web is a composite fiber containing 50% by weight or more of thermoplastic fibers, and the thermoplastic fibers comprising a low melting point component and a high melting point component. The composite fiber is
The thermoplastic fiber is composed of two or more kinds of thermoplastic fibers appropriately selected from those having different melting points, and examples of the composite fiber include a core-sheath type thermoplastic composite fiber in which the sheath side has a lower melting point than the core side. And / or laminated thermoplastic composite fibers having different melting points. It is preferable that both the core-sheath type and the laminated type composite fibers have a melting point difference of 30 ° C. or more between the high melting point component and the low melting point component.

The above-mentioned fibrous web is a composite fiber, which is formed as a fiber web having a predetermined shape by a constituent fiber obtained by mixing a predetermined amount of a non-composite fiber, if necessary, and then by heating and melting the low melting point component of the composite fiber, It is formed by integrating the above constituent fibers.

As a method of heating and melting the fibrous web, there is a method of passing the fibrous web through a pair of heating rolls, but the bulkiness,
In consideration of giving a texture and the like, a method of passing the material through a heated air chamber as described later is preferable.

Further, the content of the thermoplastic fiber constituting the above conjugate fiber is 50% by weight or more as described above, and therefore, the content of the non-composite fiber used in combination is preferably less than 50%. If the content of the composite fiber is less than 50% by weight, the strength of the nonwoven fabric as the surface material of the absorbent article described below may not be obtained. Also,
Examples of the non-composite fibers include non-composite fibers made of polyethylene terephthalate, polybutylene terephthalate, polypropylene, nylon-6, nylon-66 and the like.

Further, each of the thermoplastic fibers used to form the nonwoven fabric 10,
Considering the process of manufacturing a nonwoven fabric and the texture when used as a surface material of an absorbent article, the fineness is preferably 1 to 6 denier. Incidentally, the composite fiber and the non-composite fiber,
The fibers are not limited to those described above, and various other fibers can be selected as necessary. However, non-thermoplastic fibers such as rayon, cupra, and cotton are not preferable as a material for a non-woven fabric used as a surface material of an absorbent article in consideration of fluff drop, decrease in bulkiness, strength and the like.

Nonwoven fabric 10 of the present embodiment, as described above, the central portion 11 is formed with convex portions 11A and concave portions 11B that are regularly dispersed,
Since the convex portion 11A has a high fiber aggregate density, it has bulkiness (cushioning property), and when used as a surface material of an absorbent article, it is difficult for liquid to return, and the concave portion 11B has a fiber aggregate density. Since it has a low temperature and is in a substantially open state, it has excellent permeability for highly viscous liquids.
Since Nos. 2 and 12 have a uniform fiber aggregate density and are flat, they have an excellent feeling, and as a whole have a good feeling as a surface material.

Next, one example of the absorbent article of the present invention using the above-mentioned nonwoven fabric 10 will be described.

The absorbent article of this example includes a liquid-permeable surface material (surface sheet) that comes into contact with the skin, an absorber covered with the surface sheet, and a back sheet that covers the back surface of the absorbent body. It has a basic structure and absorbs or stores excrement such as urine, feces and menstrual blood, and as such an absorbent article,
For example, a conventionally known disposable diaper. There are incontinence pads, adult diapers or sanitary napkins.

Thus, the present absorbent article, the surface sheet is formed by the nonwoven fabric 10 described in detail above, the central portion 11 having a convex portion 11A and a concave portion 11B in the nonwoven fabric 10 in the central portion in the longitudinal direction of the surface sheet. , And both end portions 12, 12 having a uniform fiber aggregate density in the non-woven fabric 10 are located at both end portions in the width direction. Further, the absorber is a conventionally known one,
For example, there are a combination of a high-molecular absorbing polymer mainly composed of crushed pulp, and a mixture obtained by heat-treating a mixture of a thermoplastic resin, a cellulose fiber and a high-molecular absorbing polymer. Note that the present absorbent article may be appropriately provided with an elastic member for gather formation, etc., depending on its application.

Since the absorbent article is provided with the non-woven fabric 10 as a surface sheet, loose stools in the central portion 11, high-viscosity liquids such as menstrual blood do not flow, and the substantially convex portion 11B having a low fiber aggregate density and having a small hole diameter is formed. To the absorbent body, soft contact with the skin at the bulky convex portion, and effective prevention of the return of the highly viscous liquid, and a flat surface having uniform fiber aggregate density at both ends The part touches the part comfortably.

Next, one embodiment of the method of the present invention for producing the non-woven fabric 10 will be described with reference to FIGS. 3 and 4.

First, a non-woven fabric manufacturing apparatus preferably used when carrying out one embodiment of the method of the present invention will be described. In the present manufacturing apparatus, as shown in FIG. 3, a feeding unit 20 for feeding fibers containing thermoplastic fibers is used. A card machine (30) for forming a belt-shaped web (10 ') which is an intermediate product of the non-woven fabric (10) from the fibers supplied by the supply unit (20), and a belt-shaped web (10') formed in the card machine (30) to receive a convex portion (11A) in the longitudinal direction. And a concave-convex forming portion 40 for forming the non-woven fabric 10 by forming the concave-convex portion 11B and forming two rows of concave-convex portions on the strip-shaped web 10 '.
In receiving the nonwoven fabric 10 having two rows of uneven portions in the longitudinal direction, the thermoplastic fiber of the low melting point component contained in the fibrous web of the nonwoven fabric 10 is heat fused to the thermoplastic fiber of the high melting point component to form two rows. Uneven parts and three rows of flat parts adjacent to them
A heat treatment section 50 for forming a non-woven fabric 10 having 12, 12, 12;
The uneven portion 11A, 11B is formed in the central portion 11 by cutting the central flat portion 12 formed in the heat treatment portion 50 in the longitudinal direction at the center in the width direction.
And a winding section 70 for winding the nonwoven fabrics 10, 10 cut by the slitter 60 and divided into two, respectively. And is configured.

The concavo-convex forming section 40 is provided with a pair of upper and lower breathable conveyors 41 and 42 that sandwich and convey the fibrous web. The breathable conveyor 41 arranged on the lower side is an endless conveyor for transportation which is wound around the unevenness forming section 40 to the heat treatment section 50 on the downstream side, and is formed in a mesh shape, for example. Further, the air permeable conveyor 42 arranged on the upper side is an endless conveyor formed substantially flat so as to press the fiber web against the air permeable conveyor 41 on the lower side to sandwich the fiber web. It is rotatably supported by rolls.

Further, as shown in FIG. 3, the unevenness forming portion 40 discontinuously jets a gas such as air from above onto the strip-shaped web 10 ′ sandwiched by a pair of upper and lower air-permeable conveyors 41, 42 to discontinue the fibers. A gas injection device (43) having a plurality of injection ports for intruding and following the web into the surface concave portion of the lower air permeable conveyor (41) at predetermined intervals in the width direction is provided. The gas injecting device 43 includes an injecting duct 43A inserted laterally inside the rotation of the upper permeable conveyor 42 and a lower permeable conveyor 4
1 is provided with a collection duct 43B inserted laterally inside the rotation, the blower 43C allows the breathable conveyor 42 to pass from the injection duct 43A, and the strip-shaped web 10 'pressed by the breathable conveyor 42. In the width direction of the air-permeable conveyor 41, the gas is discontinuously injected by injecting gas at two predetermined intervals in the width direction as will be described later, and two uneven shapes are formed in the width direction of the uneven surface of the breathable conveyor 41 as described above. The portions are formed so that each flat surface is formed. Then, the air flow passing through the belt-shaped web 10 'and the lower air permeable conveyor 41 is returned to the blower 43C via the recovery duct 43B.

Next, the injection duct 43A will be described in detail. As shown in FIG. 4, the injection duct 43A has two slit-shaped injection ports 43D and 43D, and as described above, the strip-shaped web 1
Gas is jetted at two locations discontinuously in the 0'width direction, and the breathable conveyor 42 is provided only at the portion where the gas is jetted.
The convex portion 11A and the concave portion 11B are formed so as to conform to the concave and convex portion, and the portion where the gas is not ejected is formed as a flat surface. In this case, it is preferable that the blower 43C jets the gas at a speed of 20 to 200 m / sec. If it is less than 20 m / sec., It is difficult to form unevenness or perforations at the same time.If it is more than 200 m / sec., The fiber web is disturbed, and the energy load of the blower 43C becomes excessively uneconomical. It is a win. Also, in order to minimize the energy loss of the jet flow,
It is preferable to inject from a substantially flat mesh-like breathable conveyor 43B side from a rotation internal position as close to the breathable conveyor 43B as possible. The shape of the injection port 43D may be a large number of orifice-shaped pores,
A slit shape is preferable in order to reduce energy loss. At this time, when heat-sealing the thermoplastic fibers, it is preferable to fuse the heat-sealing fibers having a core-sheath structure with the hot air as the thermoplastic fibers in order to form irregularities or perforations in the irregularities. On the other hand, the transportation speed of the fiber web by the air permeable conveyors 41, 42 is set in relation to the gas injection speed, and is preferably set to 10 to 100 m / min.

Further, in the heat treatment section 50, since the treatment is performed with heated air, a heating roll or the like, the surfactant applied in the fiber manufacturing process is not easily removed, and it is necessary to add a new surfactant in the manufacturing process of the nonwoven fabric 10. Absent.

Next, one embodiment of the method for producing a nonwoven fabric of the present invention will be described.

First, when a fiber containing a thermoplastic fiber is supplied from the supply unit 20 to the card machine 30, the card machine 30 produces a belt-shaped web 10 ′ which is an intermediate product of the nonwoven fabric 10. This web
10 'is a pair of upper and lower air-permeable conveyors in the unevenness forming section 40.
While the strip-shaped web 10 'is being conveyed by 41 and 42, the air supplied by the blower 43C is discontinuously ejected in the width direction by the two ejection ports 43D and 43D of the ejection duct 43A to form the unevenness in the longitudinal direction. The central portions 11 in which the shaped portions 11A and 11B and the openings are dispersed are formed in two lines, and the flat portions 12, 12 are formed on both sides thereof.
After 12 is formed, it is conveyed to the heat treatment section 50, where the low melting point component is welded and integrated with the high melting point component. Thereafter, while being conveyed, the flat portion 12 located in the widthwise central portion is cut in the longitudinal direction by the slitter 60, and the uneven portions 11A and 11B to be dispersed are provided in the central portion 11, and both ends adjacent to this are provided. The non-woven fabric 10 in which the parts 12 and 12 are formed as flat surfaces is wound into two rolls by the winding part 70.

Therefore, according to the present embodiment, the uneven portion 11 is formed in the central portion 11.
The nonwoven fabric 10 having A and 11B can be easily manufactured at high speed.

Hereinafter, the nonwoven fabric of the present invention will be specifically described based on the following examples.

Example 1 In this example, an invention product 1 was manufactured as follows by using the nonwoven fabric manufacturing apparatus shown in FIG.

That is, a polyethylene-terephthalate (melting point 255 ° C.) / Polyethylene (melting point 132 ° C.) core-sheath thermoplastic composite fiber 3
A conventional carding machine for denier x 51 mm fiber web 30
And then sandwiching the fibrous web between the breathable plain weave net 41 and the concave-convex net 42, the fibrous web having a total width of 900 mm from the plain weave net 41 side to the jet port 43D of the jet duct 43A. Air is blown from 43D at a width of 120 mm at two locations in the width direction, and the fiber web is pushed into the recesses of the concavo-convex net 42 to produce a fiber web in which the dense and dense portions of the fiber aggregate density are formed at a predetermined pitch. . Then, the fibrous web in this state is passed through a heat treatment section 50 heated to 140 ° C. to weld the polyethylene portion of the low melting point component, and the fibrous web is integrated to form an uneven portion on the fibrous web. The holes were formed at a predetermined pitch and the concave portions were opened. After that, the portion in which the uneven portion is not formed is cut in the flow direction, and the uneven portion is formed in the central portion 11 and the concave portion is opened, and the both end portions 12 and 12 are uniform.
A nonwoven fabric 10 shown in the figure was produced.

The non-woven fabric 10 has an average pitch of 5.5 m in which the central portion 11 is uneven.
m, the average pore diameter of the open part is 2.5 mm, and the fiber aggregate density of the convex part is
2.9 × 10 ^-5 g / mm ² , fiber density of the concave part is 7.0 × 10 ^-5 / mm
^2. The tolerance h between the uneven bottom surfaces was 1.0 mm, the both ends 12, 12 had a substantially uniform fiber aggregate density, and the basis weight was 25 g / m ² .

Comparative Example 1 In this comparative example, Comparative product 1 was prepared as follows.

That is, the fibrous web formed by the above card machine was formed with uneven portions at a predetermined pitch over the entire width, and the concave portions were opened. Then, the nonwoven fabric was cut into a required width in the flow direction, and the entire nonwoven fabric was formed with uneven portions similar to those of the invention product 1 to prepare a comparative product 2.

Comparative Example 2 In this Comparative Example, the fibrous web formed by the above card machine was simply placed on a plain weave net and passed through heated air at 140 ° C. to melt and integrate the polyethylene portion of the low melting point component. A flat non-opened hole was prepared as a comparative product 2.

Next, the invention item 1, the comparative item 1 and the comparative item 2 were tested for the evaluation items shown in Table 1 below, and the results are shown in the corresponding columns of the same table.

According to the results shown in Table 1 above, the product 1 of the present invention is required not only for the permeability of artificial loose stool which is a highly viscous liquid as compared with the comparative products 1 and 2, but also for the surface material of the absorbent article. It can be seen that the characteristics are also excellent.

Although the nonwoven fabric of the present invention has been specifically described based on the above examples, the nonwoven fabric of the present invention is not limited to the above examples and can be variously modified without departing from the scope of the present invention. Can be changed. For example, the opening of the concave part is
It does not have to be a clear hole, and may be substantially open. Further, the above-mentioned openings are not always necessary, and the recessed portions may be recessed to the extent that body fluid can permeate, and the fiber aggregate density is low, and the irregular shape of the nonwoven fabric is regularly arranged. It does not have to be provided.

Further, the method for manufacturing a nonwoven fabric of the present invention is not limited to the above-mentioned embodiment of sandwiching and conveying by the pair of breathable conveyors 41, 42, and placing the fiber web on the breathable conveyor having irregularities. It suffices that irregularities are formed on the fibrous web while being conveyed in the state of being in the state of

〔The invention's effect〕

The non-woven fabric of the present invention can surely permeate the high-viscosity liquid and can suppress the reversion of the liquid,
It has an excellent texture and feel.

Further, the absorbent article of the present invention is excellent in permeability of highly viscous body fluid such as loose stool and menstrual blood and can suppress absorption of the highly viscous body fluid in the absorbent body so as to be absorbed and held in the absorbent body, and feel the wind such as touch to the skin. It is excellent in all cases.

Further, according to the method for producing a nonwoven fabric of the present invention, the above nonwoven fabric can be easily produced at a high speed.

[Brief description of drawings]

FIG. 1 is a partial perspective view conceptually showing one embodiment of the nonwoven fabric of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a method of manufacturing the nonwoven fabric of the present invention. FIG. 4 is a perspective view showing a non-woven fabric manufacturing apparatus that can be preferably used in a case, and FIG. 4 is a partial perspective view showing an enlarged shape of forming a concavo-convex portion on the non-woven fabric by the injection duct of the manufacturing apparatus shown in FIG. Is. 10; Non-woven fabric, 11; Central part 11A; Convex part, 11B; Concave part (open hole) 12; Both ends, 40; Concavo-convex forming part 41; Breathable conveyor 42 with irregularities; Breathable conveyor 43A; Jet port, 50; Heat treatment department

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-4-24262 (JP, A) JP-A-4-24263 (JP, A) JP-A-3-137258 (JP, A) JP-A-61- 655 (JP, A) JP-A-2-229255 (JP, A)

Claims (5)

[Claims] 1. A non-woven fabric obtained by melting and integrating thermoplastic fibers of a fibrous web containing thermoplastic fibers, wherein the non-woven fabric has a central portion and both end portions adjacent to the central portion, the central portion Is formed of a convex portion and a concave portion dispersed throughout, and the fiber assembly density of the concave portion is lower than the fiber assembly density of the convex portion, and the both end portions have substantially uniform fiber assembly density. A non-woven fabric characterized by that. 2. The non-woven fabric according to claim 1, wherein the concave portion of the central portion is substantially open. 3. The fibrous web comprises 50% by weight of thermoplastic fibers.
The non-woven fabric according to claim 1, wherein the thermoplastic fiber is a composite fiber containing the low melting point component and the high melting point component. 4. An absorbent article comprising a surface material that comes into contact with the skin and an absorbent body covered with the surface material, which absorbs excrements such as body fluids. 3)
An absorbent article formed by the non-woven fabric according to any one of 1. 5. A fiber web containing a thermoplastic fiber is placed on an air-permeable conveyor having irregularities, and while the fiber web is conveyed while being placed, the fiber web is discontinuous in the width direction. To the concave portion of the air permeable conveyor to form a concavo-convex portion on the fiber web only at the portion where the gas is jetted, and then the thermoplastic resin obtained by heating the fibrous web. The method for producing a nonwoven fabric according to claim 1, wherein the fibers are fused and integrated.