Patent Description:
An absorbent body used for absorbent articles such as disposable diapers, disposable shorts, sanitary napkins and incontinence pads contains a granular absorbent material capable of absorbing and holding liquid.

This absorbent body is produced, for example, by using an absorbent body producing apparatus <NUM> shown in <FIG>. As shown in <FIG>, one main surface side of a fiber sheet <NUM> being conveyed is nap-raised by a nap-raising device <NUM>. Then, by using a scattering device <NUM>, a granular absorbent material is scattered onto the nap-raised one main surface of the fiber sheet <NUM> while the other main surface of the fiber sheet <NUM> is supported with a planar conveyance surface, and by using a suction device <NUM>, the other main surface of the fiber sheet <NUM> is suctioned through the conveyance surface to hold the scattered absorbent material on the fiber sheet <NUM>. Then, a cover sheet <NUM> having a larger width than the fiber sheet <NUM> is laminated on the one main surface of the fiber sheet <NUM>. Then, by using a folding device <NUM>, the part of the cover sheet <NUM> protruding from the fiber sheet <NUM> is folded and overlapped with the other main surface of the fiber sheet <NUM>. Then, by using a crimping device <NUM>, the fiber sheet <NUM> and the cover sheet <NUM> are compressed in the thickness direction.

If the granular absorbent material scattered on the nap-raised fiber sheet <NUM> moves inside the fiber sheet <NUM> to be unevenly distributed due to vibrations during transport or the like, the liquid absorption decreases or rewet occurs. For this reason, it is desirable to prevent the scattered absorbent material from moving inside the fiber sheet <NUM>.

Accordingly, it is considered to apply an adhesive to the nap-raised fiber sheet <NUM> and scatter the absorbent material thereon. However, when adhering to the applied adhesive, the scattered absorbent material is prevented from moving and cannot enter the inside of the fiber sheet. For this reason, a problem occurs in that a large amount of absorbent material remains on the absorbent-material-scattered side.

In view of such circumstances, a problem to be solved by the present invention is to provide a method of producing an absorbent body for an absorbent article, capable of preventing the absorbent material from moving in a state in which the granular absorbent material is infiltrated into the inside of the nap-raised fiber sheet.

To solve the above-mentioned problem, the present invention provides a method of producing an absorbent body for an absorbent article structured as follows:.

The method of producing an absorbent body for an absorbent article is provided with: (i) a first step of supplying a base sheet having one main surface thereof applied with a first adhesive, to a conveyance device, and conveying the base sheet while suctioning another main surface of the base sheet through a conveyance surface of the conveyance device; (ii) a second step of overlapping, along the conveyance surface of the conveyance device, another main surface of a fiber sheet having one main surface thereof nap-raised with the one main surface of the base sheet applied with the first adhesive, thereby forming a first laminate where the fiber sheet is laminated on the base sheet; (iii) a third step of scattering a granular absorbent material capable of absorbing and holding liquid, onto the one main surface of the fiber sheet of the first laminate, and infiltrating the scattered absorbent material into an inside of the fiber sheet when the other main surface of the base sheet is suctioned through the conveyance surface of the conveyance device; (iv) a fourth step of overlapping one main surface of a cover sheet having the one main surface thereof applied with a second adhesive with the one main surface of the fiber sheet of the first laminate into the inside of which the absorbent material is infiltrated, thereby forming a second laminate where the cover sheet is laminated on the first laminate; and (v) a fifth step of compressing the second laminate in a thickness direction by using compression means, and spreading the first adhesive applied to the base sheet and the second adhesive applied to the cover sheet, in the inside of the fiber sheet of the second laminate.

According to the above-described method, since the first and second adhesives are spread in the inside of the fiber sheet after the granular absorbent material is infiltrated into the inside of the nap-raised fiber sheet, in a state in which the granular absorbent material is infiltrated into the inside of the nap-raised fiber sheet, the absorbent material can be prevented from moving.

Preferably, the compression means is a pair of rolls, and compresses the second laminate in the thickness direction when the second laminate passes between the pair of rolls.

In this case, the second laminate can be continuously compressed in the thickness direction with a simple structure.

Preferably, the first and second adhesives contain a thermoplastic resin. The compression means includes heating means for heating the second laminate.

In this case, by softening the first and second adhesives, the first and second adhesives can be effectively spread in the inside of the fiber sheet.

Preferably, the first and second adhesives contain a thermoplastic resin. The compression means is a pair of rolls, and compresses the second laminate in the thickness direction when the second laminate passes between the pair of rolls. At least one of the pair of rolls is heated.

In this case, the second laminate can be continuously compressed in the thickness direction with a simple structure. Moreover, by providing the pair of rolls with heating means and softening the first and second adhesives, the first and second adhesives can be effectively spread in the inside of the fiber sheet.

Preferably, the method of producing an absorbent material for an absorbent article is further provided with: (vi) a sixth step of supplying another base sheet having one main surface thereof applied with a third adhesive, to another conveyance device, and conveying the other base sheet while suctioning another main surface of the other base sheet through a conveyance surface of the other conveyance device; (vii) a seventh step of overlapping another main surface of another fiber sheet having one main surface thereof nap-raised with the one main surface of the other base sheet applied with the third adhesive, thereby forming a third laminate where the other fiber sheet is laminated on the other base sheet; (viii) an eighth step of scattering a granular other absorbent material capable of absorbing and holding liquid, onto the one main surface of the other fiber sheet of the third laminate, and infiltrating the scattered other absorbent material into an inside of the other fiber sheet when the other main surface of the other base sheet is suctioned through the conveyance surface of the other conveyance device; (ix) a ninth step of applying a fourth adhesive to the other main surface of the base sheet of the second laminate, and overlapping the other main surface of the base sheet of the second laminate applied with the fourth adhesive with the one main surface of the other fiber sheet of the third laminate into the inside of which the other absorbent material is infiltrated, thereby forming a fourth laminate where the second laminate is laminated on the third laminate; and (x) a tenth step of compressing the fourth laminate in the thickness direction by using other compression means, and spreading the third adhesive applied to the other base sheet and the fourth adhesive applied to the other main surface of the base sheet of the second laminate, in the inside of the other fiber sheet of the fourth laminate.

In this case, an absorbent body including two layers of fiber sheets can be produced. Since the third and fourth adhesives are spread inside the other fiber sheet after the granular other absorbent material is infiltrated into the inside of the nap-raised other fiber sheet, in a state in which the granular other absorbent material is infiltrated into the inside of the nap-raised other fiber sheet, the other absorbent material can be prevented from moving.

Since the distribution of the absorbent materials which is difficult in the absorbent body including only one layer of fiber sheet can be realized in the absorbent body including two layers of fiber sheets, the degree of freedom in design of the absorbent article is increased.

Preferably, when the fourth laminate is seen through in the thickness direction, (a) a plurality of first areas where the absorbent material is scattered so as to be continuous on the one main surface of the fiber sheet are disposed at intervals in a conveyance direction of the fourth laminate, (b) a plurality of second areas where the other absorbent material is scattered so as to be continuous on the one main surface of the other fiber sheet are disposed at intervals in the conveyance direction, (c) each of the first areas overlaps with only one of the second areas, respectively, and (d) the first areas are narrower than the second areas in the conveyance direction, or the second areas are narrower than the first areas in the conveyance direction.

In this case, the distribution of the absorbent materials in the thickness direction inside the absorbent body can be varied in the conveyance direction.

Moreover, the present invention provides a method of producing an absorbent article as claimed in claim <NUM>.

The absorbent article includes the absorbent body produced by the above-described method of producing an absorbent body for an absorbent article, (A) when seen through in the thickness direction, the first areas are narrower than the second areas in the conveyance direction and the fiber sheet is disposed on a skin surface side of the other fiber sheet, or (B) when seen through in the thickness direction, the second areas are narrower than the first areas in the conveyance direction and the other fiber sheet is disposed on the skin surface side of the fiber sheet.

In this case, since the absorbent materials are disposed more widely on the non-skin surface side than on the skin surface side, rewet is less likely to occur than when the absorbent materials are disposed more widely on the skin surface side than on the non-skin surface side.

According to the present invention, in a state in which the granular absorbent material is infiltrated into the inside of the nap-raised fiber sheet, the absorbent material can be prevented from moving.

A method of producing an absorbent body for an absorbent article according to the first embodiment will be described with reference to <FIG>. <FIG> is a schematic view of an absorbent body producing apparatus <NUM> used in the first embodiment. <FIG> is a relevant part enlarged view of the absorbent body producing apparatus <NUM>. <FIG> are schematic views of an absorbent body <NUM> cut vertically to a conveyance direction. <FIG> is an assembled view, and <FIG> is a disassembled view.

As shown in <FIG>, in the absorbent body producing apparatus <NUM>, after a breathable continuous base sheet <NUM> and fiber sheet <NUM> supplied to a first conveyance device <NUM> and a continuous cover sheet <NUM> supplied to a second conveyance device <NUM> are overlapped with each other, they are compressed in the thickness direction by a compression device <NUM> and before the cover sheet <NUM> is overlapped, a granular absorbent material <NUM> capable of absorbing and holding liquid is scattered from a scattering device <NUM> onto one main surface <NUM> of the fiber sheet <NUM> previously nap-raised by a nap-raising device <NUM>, thereby continuously producing the absorbent body <NUM>. The absorbent material <NUM> is, for example, SAP (super absorbent polymer).

In the first conveyance device <NUM>, a breathable cylindrical conveyance surface 16a having a mesh structure or the like rotates in the direction indicated by the arrow 16r, and the base sheet <NUM> is wound on the conveyance surface <NUM>. The first conveyance device <NUM> has inside a space (vacuum chamber) being negative in pressure, and air is suctioned inward from the conveyance surface <NUM> through the conveyance surface <NUM> in a section <NUM> (hereinafter, referred to as suction section <NUM>) between a first position 16i where the base sheet <NUM> has moved by a predetermined distance after being wound and a second position 16j where the base sheet <NUM> separates from the conveyance surface <NUM>.

The base sheet <NUM> is conveyed in the direction indicated by the arrow 60p, and a first adhesive <NUM> such as hot melt adhesive (see <FIG>) is applied to one main surface <NUM> thereof by a first applying device <NUM> in such a manner that the breathability is maintained. Then, after passing a guide roll 13a, the base sheet <NUM> is supplied to the first conveyance device <NUM> so that the other main surface 60t thereof is in contact with the conveyance surface <NUM> of the first conveyance device <NUM> (see <FIG>), and is wound on the conveyance surface <NUM> of the first conveyance device <NUM>. The base sheet <NUM> is suctioned through the conveyance surface <NUM> in the suction section <NUM>, and moves together with the conveyance surface <NUM>. The base sheet <NUM> is, for example, a sheet of tissue paper.

The fiber sheet <NUM> is conveyed in the direction indicated by the arrow 52p, is wound on the nap-raising device <NUM> by guide rolls 13b to 13d, and has one main surface <NUM> side thereof nap-raised by the nap-raising device <NUM>. Then, the fiber sheet <NUM> is supplied to the first conveyance device <NUM> in such a manner that the other main surface 52t is overlapped with the one main surface <NUM> of the base sheet <NUM> wound on the conveyance surface <NUM> of the first conveyance device <NUM> (see <FIG>), a first laminate 50p where the fiber sheet <NUM> is laminated on the base sheet <NUM> is formed, and the fiber sheet <NUM> moves together with the base sheet <NUM>. The fiber sheet <NUM> is, for example, an air-through nonwoven fabric. The nap-raising device <NUM> is, for example, a tiller in which a plurality of blade edges scratch the one main surface <NUM> of the fiber sheet <NUM> to nap-raise the one main surface <NUM> side so as to be bulky. The nap-raising device <NUM> is unnecessary when the fiber sheet <NUM> having the one main surface <NUM> side thereof previously nap-raised is used.

The scattering device <NUM> scatters the absorbent material <NUM> onto the nap-raised one main surface <NUM> of the fiber sheet <NUM> of the first laminate 50p. The absorbent material <NUM> is scattered onto a scatter area <NUM> (see <FIG>) on the upstream side in the conveyance direction of the first position 16i where suction is started. The scattering device <NUM> scatters the absorbent material <NUM> onto the one main surface <NUM> of the fiber sheet <NUM>, for example, by mixing a plurality of kinds of absorbent materials stored in a storage 14a by a mixing device 14b and discharging the mixed absorbent material <NUM> from a non-illustrated scatter port of an opening and closing device 14c. The opening and closing device 14c opens and closes the scatter port to thereby scatter the absorbent material <NUM> intermittently, that is, in such a manner as to continue at intervals in the conveyance direction of the fiber sheet <NUM>.

A member <NUM> in the form of a plate (hereinafter, referred to as plate-like member <NUM>) is disposed so as to face, with a space in between, the one main surface <NUM> of the fiber sheet <NUM> of the first laminate 50p scattered with the absorbent material <NUM> and being conveyed in the suction section <NUM>. One end 17a of the plate-like member <NUM> adjoins the non-illustrated scatter port of the scattering device <NUM>, and the other end 17b of the plate-like member <NUM> adjoins the second conveyance device <NUM>.

In the second conveyance device <NUM>, a breathable endless belt <NUM> having a mesh structure or the like circulates in the direction indicated by the arrow 18p, and a vacuum box <NUM> is disposed inside of the endless belt <NUM>.

The cover sheet <NUM> is conveyed in the direction indicated by the arrow 62p, and a second adhesive <NUM> such as hot melt adhesive (see <FIG>) is applied to one main surface <NUM> thereof by a second applying device <NUM>; then, the cover sheet <NUM> is supplied to the second conveyance device <NUM> in such a manner that the other main surface 62t is in contact with the endless belt <NUM> of the second conveyance device <NUM>, and moves together with the endless belt <NUM> while being suctioned through the endless belt <NUM>. The cover sheet <NUM> is, for example, a sheet of tissue paper.

The first conveyance device <NUM> and the second conveyance device <NUM> are disposed close to each other, and the one main surface <NUM> of the fiber sheet <NUM> of the first laminate 50p being conveyed by the first conveyance device <NUM> is overlapped with the one main surface <NUM>, applied with the second adhesive <NUM> (see <FIG>), of the cover sheet <NUM> being conveyed by the second conveyance device <NUM>, whereby a second laminate 50q where the cover sheet <NUM> is laminated on the first laminate 50p is formed.

The second laminate 50q, that is, the laminated base sheet <NUM>, fiber sheet <NUM> and cover sheet <NUM> pass between a pair of rolls 19a and 19b of the compression device <NUM> to be compressed in the thickness direction, so that the first adhesive <NUM> (see <FIG>) applied to the base sheet <NUM> and the second adhesive <NUM> (see <FIG>) applied to the cover sheet <NUM> spread in the inside of the fiber sheet <NUM> of the second laminate 50q. This forms the continuous absorbent body <NUM> where the absorbent material <NUM> inside the fiber sheet <NUM> is fixed. Although not shown, the continuous absorbent body <NUM> is conveyed to a post-process to be cut into pieces, and then, disposed in appropriate positions of an absorbent article.

Although the second laminate 50q may be compressed in the thickness direction by using compression means other than the pair of rolls 19a and 19b, the use of the pair of rolls 19a and 19b enables the second laminate 50q to be continuously compressed in the thickness direction with a simple structure.

It is preferable for the compression means to include heating means for heating the second laminate 50q. For example, at least one of the pair of rolls 19a and 19b is heated by using the first and second adhesives <NUM> and <NUM> containing a thermoplastic resin such as hot melt adhesive. In this case, the second laminate 50q is heated to soften the first and second adhesives <NUM> and <NUM>, whereby the first and second adhesives <NUM> and <NUM> can be effectively spread in the inside of the fiber sheet <NUM>.

The first and second adhesives <NUM> and <NUM> may be either the same adhesive or different adhesives. Moreover, the first and second adhesives <NUM> and <NUM> may be other than adhesives containing a thermoplastic resin.

Next, the plate-like member <NUM> will be further described. As shown in <FIG>, one main surface <NUM> of the plate-like member <NUM> faces, with a space in between, the one main surface <NUM> of the fiber sheet <NUM> of the first laminate 50p scattered with the absorbent material <NUM> and being conveyed in the suction section <NUM>. The plate-like member <NUM> has a plurality of through holes 17p passing through between the main surfaces <NUM> and 17t. Since the base sheet <NUM> is suctioned through the conveyance surface <NUM>, as indicated by the arrows <NUM>, the air flow is caused that passes through the through holes 17p of the plate-like member <NUM> and penetrates the fiber sheet <NUM> to move inward from the conveyance surface <NUM>.

Compared with when no plate-like member <NUM> is provided, in a second facing area <NUM> facing the through holes 17p of the plate-like member <NUM>, the air flow is high in flow speed until it impinges on the one main surface <NUM> of the fiber sheet <NUM>, and high in dynamic pressure on the one main surface <NUM> side of the fiber sheet <NUM>. For this reason, compared with when no plate-like member <NUM> is provided, the difference in atmospheric pressure, that is, the difference in static pressure is large between the conveyance surface <NUM> side (in <FIG>, the area indicated by reference numeral <NUM>) and the opposite side (in <FIG>, the area indicated by reference numeral <NUM>) of the fiber sheet <NUM>.

The provision of the plate-like member <NUM> makes it possible to enhance the air flow passing through the fiber sheet <NUM> to move toward the conveyance surface <NUM> to increase the force by which the granular absorbent material <NUM> scattered onto the one main surface <NUM> of the fiber sheet <NUM> is suctioned toward the other main surface 52t of the fiber sheet <NUM>.

Moreover, it is possible to make the air flow weak in a first facing area <NUM> facing the part of the plate-like member <NUM> where no through holes 17p are formed and make the air flow strong in the second facing area <NUM> facing the through holes 17p of the plate-like member <NUM>. In this case, the fiber sheet <NUM> passes the first facing area <NUM> where the air flow is weak and the second facing area <NUM> where the air flow is strong, so that shaking of each fiber of the fiber sheet <NUM> becomes fierce and changes in the flow direction and strength of the air become drastic inside the fiber sheet <NUM>. For this reason, the absorbent material <NUM> scattered onto the one main surface <NUM> of the fiber sheet <NUM> is readily released even if entangled with the fibers of the fiber sheet <NUM>, so that it easily moves inside the fiber sheet <NUM> toward the other main surface 52t of the fiber sheet <NUM>.

Although the granular absorbent material <NUM> can be infiltrated into the inside of the fiber sheet <NUM> of the first laminate 50p without the provision of the plate-like member <NUM>, the provision of the plate-like member <NUM> enables a larger amount of granular absorbent material <NUM> to be infiltrated into the inside of the fiber sheet <NUM> from the nap-raised one main surface <NUM> of the fiber sheet <NUM>.

In the absorbent body <NUM>, as shown in <FIG>, the one main surface <NUM> of the base sheet <NUM> and the other main surface 52t of the fiber sheet <NUM> are bonded together by the first adhesive <NUM>. The one main surface <NUM> of the cover sheet <NUM> and the one main surface <NUM> of the fiber sheet <NUM> are bonded together by the second adhesive <NUM>. Inside the fiber sheet <NUM>, the absorbent material <NUM> is disposed. While it is preferable to use the same adhesive as the first and second adhesives <NUM> and <NUM>, adhesives different in ingredients may be used.

When the absorbent body <NUM> is used for the absorbent article, the absorbent article is formed as follows: The one main surface <NUM> of the fiber sheet <NUM> is disposed on the skin surface side (that is, the side close to the user's skin in a state in which the absorbent article is being used) and the other main surface 52t of the fiber sheet <NUM> is disposed on the non-skin surface side (that is, the side farther from the user's skin in a state in which the absorbent article is being used).

In the absorbent body <NUM>, as mentioned previously, a larger amount of absorbent material <NUM> scattered onto the nap-raised one main surface <NUM> of the fiber sheet <NUM> can be infiltrated into the inside of the fiber sheet <NUM>. For this reason, the amount of absorbent material <NUM> disposed on the one main surface <NUM> side of the fiber sheet <NUM> can be made small. Although a large mount of absorbent material <NUM> disposed on the skin surface side gives a rough touch, the rough touch can be suppressed because the amount of absorbent material <NUM> disposed on the skin surface side can be made small.

A method of producing an absorbent material for an absorbent article according to the first embodiment for producing the absorbent body <NUM> by using the above-described absorbent body producing apparatus <NUM> is provided with the following first to five steps:
(i) At the first step, the base sheet <NUM> having the one main surface <NUM> thereof applied with the first adhesive <NUM> is supplied to the first conveyance device <NUM> and conveyed while the other main surface 60t of the base sheet <NUM> is suctioned through the conveyance surface <NUM> of the first conveyance device <NUM>. (ii) At the second step, the other main surface 52t of the fiber sheet <NUM> having the one main surface <NUM> thereof nap-raised is overlapped with the one main surface <NUM> of the base sheet <NUM> applied with the first adhesive <NUM>, thereby forming the first laminate 50p where the fiber sheet <NUM> is laminated on the base sheet <NUM>. (iii) At the third step, the granular absorbent material <NUM> capable of absorbing and holding liquid is scattered onto the one main surface <NUM> of the fiber sheet <NUM> of the first laminate 50p, and the scattered absorbent material <NUM> is infiltrated into the inside of the fiber sheet <NUM> when the other main surface 60t of the base sheet <NUM> is suctioned through the conveyance surface <NUM> of the first conveyance device <NUM>. (iv) At the fourth step, the one main surface <NUM> of the cover sheet <NUM> having the one main surface <NUM> thereof applied with the second adhesive <NUM> is overlapped with the one main surface <NUM> of the fiber sheet <NUM> of the first laminate 50p into the inside of which the absorbent material <NUM> is infiltrated, thereby forming the second laminate 50q where the cover sheet <NUM> is laminated on the first laminate 50p. (v) At the fifth step, the second laminate 50q is compressed in the thickness direction by using the compression means (compression device <NUM>), so that the first adhesive <NUM> applied to the base sheet <NUM> and the second adhesive <NUM> applied to the cover sheet <NUM> are spread in the inside of the fiber sheet <NUM> of the second laminate 50q.

If the first adhesive <NUM> is applied to the one main surface <NUM> of the fiber sheet <NUM> and the granular absorbent material <NUM> is scattered thereon to unlike the above-described method of the first embodiment, since the absorbent material <NUM> is bonded to the first adhesive <NUM>, the absorbent material <NUM> is not easily infiltrated into the inside of the fiber sheet <NUM>. On the contrary, according to the above-described method of the first embodiment, since the first adhesive <NUM> is not directly applied to the one main surface <NUM> of the fiber sheet <NUM> onto which the absorbent material <NUM> is scattered, the absorbent material <NUM> scattered onto the one main surface <NUM> of the fiber sheet <NUM> is easily infiltrated into the inside of the fiber sheet <NUM>. For this reason, the absorbent material <NUM> can be broadly distributed inside the fiber sheet <NUM>.

The second laminate 50q in a state in which the absorbent material <NUM> is broadly distributed inside the fiber sheet <NUM> is compressed to spread the first adhesive <NUM> applied to the base sheet <NUM> and the second adhesive <NUM> applied to the cover sheet <NUM> inside the fiber sheet <NUM>, which makes it possible to fix the absorbent material <NUM> distributed inside the fiber sheet <NUM> inside the fiber sheet <NUM>.

Consequently, in a state in which the granular absorbent material <NUM> is infiltrated into the inside of the nap-raised fiber sheet <NUM>, the absorbent material <NUM> can be prevented from moving.

<FIG> is a schematic view of an absorbent body producing apparatus 10a of the first modification in which a belt-like member <NUM> is used instead of the plate-like member <NUM>. As shown in <FIG>, the absorbent body producing apparatus 10a is structured substantially similarly to the absorbent body producing apparatus <NUM> used in the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and parts of the same structure as those of the first embodiment are denoted by the same reference numerals.

As in the first embodiment, after a first adhesive such as hot melt adhesive is applied to the one main surface <NUM> by the first applying device <NUM> in such a manner that the breathability is maintained, the base sheet <NUM> is wound on the breathable cylindrical conveyance surface <NUM> of a first conveyance device 16a. After the one main surface <NUM> side is nap-raised by the nap-raising device <NUM>, the fiber sheet <NUM> is overlapped with the one main surface <NUM> of the base sheet <NUM> where the first adhesive is applied. This forms the first laminate 50p. In the first laminate 50p, the absorbent material <NUM> supplied from the scattering device <NUM> is scattered onto the one main surface <NUM> of the fiber sheet <NUM>.

Inside the first conveyance device 16a, a vacuum box <NUM> is provided so that the base sheet <NUM> is suctioned through the conveyance surface <NUM> over the entire section where the base sheet <NUM> is wound. Unlike the first embodiment, the suction section is the entire section where the base sheet <NUM> is wound on the conveyance surface <NUM>, and the absorbent material <NUM> is scattered in the middle of the suction section.

After the second adhesive such as hot melt adhesive is applied to the one main surface <NUM> by the second applying device <NUM>, the cover sheet <NUM> is overlapped with the one main surface <NUM> of the fiber sheet <NUM> of the first laminate 50p scattered with the absorbent material <NUM>. This forms the second laminate 50q. Unlike the first embodiment, the second conveyance device <NUM> is absent, and the cover sheet <NUM> and the second laminate 50q are conveyed by the first conveyance device 16a.

The second laminate 50q is discharged from the first conveyance device 16a and is then compressed in the thickness direction by means of the compression device <NUM>, so that the first and second adhesives spread in the inside of the fiber sheet <NUM>. This forms the continuous absorbent body <NUM> where the absorbent material <NUM> is fixed.

The belt-like member <NUM> is a breathable endless belt, and is structured so as to circulate in the direction indicated by the arrow 17r. For example, the belt-like member <NUM> is formed so as to have a mesh structure or the like, or through holes, slits or the like are formed on the belt-like member <NUM>.

While the belt-like member <NUM> and the fiber sheet <NUM> of the first laminate 50p wound on the conveyance surface <NUM> of the first conveyance device 16a are shown as being separated from each other in <FIG>, the belt-like member <NUM> moves together with the fiber sheet <NUM> while being in contact with the one main surface <NUM> of the fiber sheet <NUM> scattered with the absorbent material <NUM>. That is, the first laminate 50p where the fiber sheet <NUM> and the base sheet <NUM> are laminated is conveyed while being sandwiched between the conveyance surface <NUM> and the belt-like member <NUM> and at this time, is suctioned through the conveyance surface <NUM> so that air flows from the belt-like member <NUM> side to the conveyance surface <NUM> side.

By appropriately structuring the belt-like member <NUM>, the air flow penetrating the fiber sheet <NUM> to move toward the conveyance surface <NUM> is suppressed, so that the atmospheric pressure difference between the conveyance surface <NUM> side and the opposite side of the fiber sheet <NUM> can be made large. This enables a larger amount of granular absorbent material <NUM> to be infiltrated into the inside of the fiber sheet <NUM> from the nap-raised one main surface <NUM> of the fiber sheet <NUM>.

Consequently, as in the first embodiment, in a state in which the granular absorbent material <NUM> is infiltrated into the inside of the nap-raised fiber sheet <NUM>, the absorbent material <NUM> can be prevented from moving.

A second embodiment in which an absorbent body <NUM> including two layers of fiber sheets <NUM> and <NUM> is produced will be described with reference to <FIG>. <FIG> is a schematic view of an absorbent body producing apparatus <NUM> used in the second embodiment. <FIG> are schematic views of the absorbent body <NUM> cut vertically to a conveyance direction. <FIG> is an assembled view, and <FIG> is a disassembled view.

As shown in <FIG>, the absorbent body producing apparatus <NUM> is provided with: first and second apparatuses 11a and 11b having the same structure as the absorbent body producing apparatus <NUM> of the first embodiment; a third applying device <NUM>; and a folding device <NUM>.

The first apparatus 11a continuously produces, as in the first embodiment, the second laminate 50q in which the continuous base sheet <NUM> (hereinafter, referred to also as intermediate sheet <NUM>), the continuous fiber sheet <NUM> and the continuous cover sheet <NUM> are laminated. The second laminate 50q is compressed in the thickness direction by means of the compression device <NUM>.

The second apparatus 11b continuously produces, substantially as in the first embodiment, a fourth laminate <NUM> in which a continuous other base sheet <NUM>, a continuous other fiber sheet <NUM> and the continuous second laminate 50q are laminated. The fourth laminate <NUM> is compressed in the thickness direction by means of the compression device <NUM>.

Specifically, in the second apparatus 11b, the other fiber sheet <NUM> has one main surface <NUM> side thereof nap-raised by the nap-raising device <NUM> before supplied to the first conveyance device <NUM>. The other base sheet <NUM> has breathability, and before it is supplied to the first conveyance device <NUM>, a third adhesive <NUM> such as hot melt adhesive (see <FIG>) is applied to one main surface <NUM> by the first applying device <NUM> in such a manner that the breathability is maintained. The other main surface 64t of the other base sheet <NUM> is suctioned through the conveyance surface <NUM> of the first conveyance device <NUM>. The other main surface 54t of the other fiber sheet <NUM> and the one main surface <NUM> of the other base sheet <NUM> are overlapped with each other to form a third laminate 50r where the other fiber sheet <NUM> is laminated on the other base sheet <NUM>.

In the second laminate 50q formed by the first apparatus 11a, after a fourth adhesive <NUM> such as hot melt adhesive (see <FIG>) is applied to the other main surface 60t of the intermediate sheet <NUM> of the second laminate 50q by the second applying device <NUM>, the other main surface 60t of the intermediate sheet <NUM> of the second laminate 50q is overlapped with the one main surface <NUM> of the other fiber sheet <NUM> of the third laminate 50r. This forms the fourth laminate <NUM> where the second laminate 50q is laminated on the third laminate 50r.

As shown in <FIG>, the cover sheet <NUM> is larger in the dimension in the width direction (a direction vertical to the conveyance direction and the thickness direction) than the other sheets <NUM>, <NUM>, <NUM> and <NUM>, and is laminated so as to protrude from both sides in the width direction of the other sheets <NUM>, <NUM>, <NUM> and <NUM>.

As shown in <FIG>, <FIG>, in the third applying device <NUM>, a fifth adhesive <NUM> such as hot melt adhesive is applied to the one main surface <NUM> of parts 62a and 62b on both sides in the width direction of the cover sheet <NUM>. The folding device <NUM> folds the parts 62a and 62b on both sides in the width direction of the cover sheet <NUM> applied with the fifth adhesive <NUM> and overlaps them with the other base sheet <NUM>. This forms the continuous absorbent body <NUM> structured so as to be wrapped with the cover sheet <NUM>.

As shown in <FIG>, in the absorbent body <NUM>, the one main surface <NUM> of the intermediate sheet <NUM> and the other main surface 52t of the fiber sheet <NUM> are bonded together by the first adhesive <NUM> and the one main surface <NUM> of the cover sheet <NUM> and the one main surface <NUM> of the fiber sheet <NUM> are bonded together by the second adhesive <NUM>. Moreover, the one main surface <NUM> of the other base sheet <NUM> and the other main surface 54t of the other fiber sheet <NUM> are bonded together by the third adhesive <NUM>, and the other main surface 60t of the intermediate sheet <NUM> and the one main surface <NUM> of the other fiber sheet <NUM> are bonded together by the fourth adhesive <NUM>. The one main surface <NUM> of parts 62a and 62b on both sides in the width direction of the cover sheet <NUM> and the other main surface 64t of the other base sheet <NUM> are bonded together by the fifth adhesive <NUM>. The absorbent material <NUM> is disposed inside the fiber sheet <NUM>, and an other absorbent material <NUM> is disposed inside the other fiber sheet <NUM>. While it is preferable to use the same adhesive as the first to fifth adhesives <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, adhesives different in ingredients may be used.

<FIG> are schematic views of the second to fourth laminates 50q to <NUM> seen through in the thickness direction. In <FIG>, the direction indicated by the arrow 50x is the conveyance direction.

As shown in <FIG>, when the second laminate 50q is seen through in the thickness direction, a plurality of first areas <NUM> where the absorbent material <NUM> is scattered so as to be continuous on the one main surface <NUM> of the fiber sheet <NUM> are disposed at intervals in the conveyance direction.

As shown in <FIG>, when the third laminate 50r is seen through in the thickness direction, a plurality of second areas <NUM> where the other absorbent material <NUM> is scattered so as to be continuous on the one main surface <NUM> of the other fiber sheet <NUM> are disposed at intervals in the conveyance direction.

As shown in <FIG>, when the fourth laminate <NUM> is seen through in the thickness direction, each of the first areas <NUM> overlaps with only one of the second areas <NUM>, respectively, and a plurality of continuous areas <NUM> where one of the first areas <NUM> and one of the second areas <NUM> overlap with each other, respectively, are disposed at intervals in the conveyance direction. The fourth laminate <NUM> is, as indicated by the broken lines <NUM>, cut between the adjoining continuous areas <NUM> into pieces, and disposed on a non-illustrated absorbent article.

When seen through in the thickness direction, the first areas <NUM> and the second areas <NUM> may be either the same or different from each other in area and shape, and the first areas <NUM> and the second areas <NUM> may be situated so as to completely coincide with each other or may be situated so as to be shifted from each other.

In the absorbent body <NUM> where one of the first area <NUM> and the second area <NUM> is narrower than the other thereof in the conveyance direction as shown in <FIG>, the distribution of the absorbent materials <NUM> and <NUM> in the thickness direction can be varied in the conveyance direction.

<FIG> is a schematic view of the absorbent body <NUM> cut vertically in the width direction. When the second area <NUM> is narrower than the first area <NUM> in the conveyance direction as shown in <FIG>, it is desirable to dispose the absorbent body <NUM> on the absorbent article so that the other fiber sheet <NUM> is on the skin side of the fiber sheet <NUM>. On the other hand, although not shown, when the first area <NUM> is narrower than the second area <NUM> in the conveyance direction, it is desirable to dispose the absorbent body <NUM> on the absorbent article so that the fiber sheet <NUM> is on the skin side of the other fiber sheet <NUM>.

When the absorbent body <NUM> is disposed as described above, since the absorbent materials <NUM> and <NUM> are disposed more widely on the non-skin surface side than on the skin surface side, rewet is less likely to occur than when the absorbent materials <NUM> and <NUM> are disposed more widely on the skin surface side than on the non-skin surface side.

According to the method of producing an absorbent body for an absorbent article according to the second embodiment for producing the absorbent body <NUM> by using the above-described absorbent body producing apparatus <NUM>, the above-described first to fifth steps are performed by using the first apparatus 11a and the following sixth to tenth steps are performed by using the second apparatus 11b:
(vi) At the sixth step, the other base sheet <NUM> having the one main surface <NUM> thereof applied with the third adhesive <NUM> is supplied to the other conveyance device (the first conveyance device <NUM> of the second apparatus 11b) and conveyed while the other main surface 64t of the other base sheet <NUM> is suctioned through the conveyance surface of the other conveyance device (the conveyance surface <NUM> of the first conveyance device <NUM> of the second apparatus 11b). (vii) At the seventh step, the other main surface 54t of the other fiber sheet <NUM> having the one main surface <NUM> thereof nap-raised is overlapped with the one main surface <NUM> of the other base sheet <NUM> applied with the third adhesive <NUM>, thereby forming the third laminate 50r where the other fiber sheet <NUM> is laminated on the other base sheet <NUM>. (viii) At the eighth step, the granular other absorbent material <NUM> capable of absorbing and holding liquid is scattered onto the one main surface <NUM> of the fiber sheet <NUM> of the third laminate 50r, and the scattered absorbent material <NUM> is infiltrated into the inside of the other fiber sheet <NUM> when the other main surface 64t of the other base sheet <NUM> is suctioned through the conveyance surface of the other conveyance device (the conveyance surface <NUM> of the first conveyance device <NUM> of the second apparatus 11b). (ix) At the ninth step, the fourth adhesive <NUM> is applied to the other main surface 60t of the base sheet <NUM> of the second laminate 50q, and the other main surface 60t of the base sheet <NUM> of the second laminate 50q applied with the fourth adhesive <NUM> is overlapped with the one main surface <NUM> of the other fiber sheet <NUM> of the third laminate 50r into the inside of which the other absorbent material <NUM> is infiltrated, thereby forming the fourth laminate <NUM> where the second laminate 50q is laminated on the third laminate 50r. (x) At the tenth step, the fourth laminate <NUM> is compressed in the thickness direction by using the other compression means (the compression device <NUM> of the second apparatus 11b), so that the third adhesive <NUM> applied to the other base sheet <NUM> and the fourth adhesive <NUM> applied to the base sheet 60t of the base sheet <NUM> of the second laminate 50q are spread in the inside of the other fiber sheet <NUM> of the fourth laminate <NUM>.

In the second embodiment, as in the first embodiment, by the first to fifth steps, in a state in which the granular absorbent material <NUM> is infiltrated into the inside of the nap-raised fiber sheet <NUM>, the absorbent material <NUM> can be prevented from moving. Moreover, by the sixth to tenth steps, in a state in which the granular other absorbent material <NUM> is infiltrated into the inside of the nap-raised other fiber sheet <NUM>, the other absorbent material <NUM> can be prevented from moving.

By the above-described method of the second embodiment, the absorbent body <NUM> including the two layers of fiber sheets <NUM> and <NUM> can be produced from the fourth laminate <NUM>. In the absorbent body <NUM> including the two layers of the fiber sheets <NUM> and <NUM>, the combination of the distribution of the absorbent material <NUM> in the fiber sheet <NUM> of the first layer and the distribution of the other absorbent material <NUM> in the other fiber sheet <NUM> of the second layer enables the realization of the distribution of the absorbent materials <NUM> and <NUM> which is difficult in the absorbent body <NUM> including only one layer of fiber sheet <NUM> as in the first embodiment. For this reason, the use of the absorbent body <NUM> including the two layers of fiber sheets <NUM> and <NUM> increases the degree of freedom in design of the absorbent article.

As described above, by compressing the laminates 50q; 50q and 50r in the thickness direction and spreading the applied adhesives <NUM>, <NUM>; <NUM>, <NUM>, <NUM> and <NUM> in the inside of the nap-raised fiber sheets <NUM>; <NUM> and <NUM>, in a state in which the granular absorbent materials <NUM>; <NUM> and <NUM> are infiltrated into the inside of the nap-raised fiber sheets <NUM>; <NUM> and <NUM>, the absorbent materials <NUM>; <NUM> and <NUM> can be prevented from moving.

The present invention is not limited to the above-described embodiments and may be variously modified when carried out.

Claim 1:
A method of producing an absorbent body (<NUM>, <NUM>) for an absorbent article, the method comprising:
a first step of supplying a base sheet (<NUM>) having one main surface (<NUM>) thereof applied with a first adhesive (<NUM>), to a conveyance device (<NUM>), and conveying the base sheet (<NUM>) while suctioning another main surface (60t) of the base sheet (<NUM>) through a conveyance surface of the conveyance device (<NUM>);
a second step of overlapping, along the conveyance surface (<NUM>) of the conveyance device (<NUM>), another main surface (52t) of a fiber sheet (<NUM>) having one main surface (<NUM>) thereof nap-raised with the one main surface (<NUM>) of the base sheet (<NUM>) applied with the first adhesive (<NUM>), thereby forming a first laminate (50p) where the fiber sheet (<NUM>) is laminated on the base sheet (<NUM>);
a third step of scattering a granular absorbent material (<NUM>) capable of absorbing and holding liquid, onto the one main surface (<NUM>) of the fiber sheet (<NUM>) of the first laminate (50p), and infiltrating the scattered absorbent material (<NUM>) into an inside of the fiber sheet (<NUM>) when the other main surface (60t) of the base sheet (<NUM>) is suctioned through the conveyance surface (<NUM>) of the conveyance device (<NUM>);
a fourth step of overlapping one main surface (<NUM>) of a cover sheet (<NUM>) having the one main surface (<NUM>) thereof applied with a second adhesive (<NUM>) with the one main surface (<NUM>) of the fiber sheet (<NUM>) of the first laminate (50p) into the inside of which the absorbent material (<NUM>) is infiltrated, thereby forming a second laminate (50q) where the cover sheet (<NUM>) is laminated on the first laminate (50p); and
a fifth step of compressing the second laminate (50q) in a thickness direction by using compression means (<NUM>), and spreading the first adhesive (<NUM>) applied to the base sheet (<NUM>) and the second adhesive (<NUM>) applied to the cover sheet (<NUM>), in the inside of the fiber sheet (<NUM>) of the second laminate (50q).