CN112351761A

CN112351761A - Absorbent body and absorbent article

Info

Publication number: CN112351761A
Application number: CN201880090083.4A
Authority: CN
Inventors: 永田真悟; 小林慧子; 重松雅人
Original assignee: Daicel Corp
Current assignee: Daicel Corp
Priority date: 2018-05-24
Filing date: 2018-05-24
Publication date: 2021-02-09
Also published as: JPWO2019224988A1; WO2019224988A1

Abstract

The absorbent body is provided with: the absorbent article includes a base sheet formed of a nonwoven fabric, a core disposed above the base sheet, and water-absorbent particles dispersed and disposed between the base sheet and the core. The core is formed of tow band obtained by crimping and opening long fibers of cellulose acetate tow.

Description

Absorbent body and absorbent article

Technical Field

The present invention relates to an absorbent body and an absorbent article.

Background

In the present specification, the following terms are used.

TD: the total fiber (total denier) is the fiber (grams per 9000 m) of the aggregate of tow (tow band).

FD: is single fiber (denier per filament) and means the fiber (grams per 9000 m) of a single fiber (1 filament). Also referred to as filament denier.

Absorbent articles as sanitary products such as disposable diapers and pads for preventing urine leakage include, for example: an absorbent body that absorbs moisture, a top sheet (top sheet) having liquid permeability, and a back sheet (back sheet) having air permeability.

As disclosed in patent document 1 or 2, for example, the absorbent body includes a pair of outer nonwoven fabrics formed of fluff pulp or the like, and a core disposed between the pair of outer nonwoven fabrics. The core is made of, for example, an inner nonwoven fabric having a relatively low density, which is formed by bonding short fibers in a network. Water-absorbing particles made of, for example, a Super Absorbent Polymer (SAP) are dispersed between the pair of outer nonwoven fabrics and the core. In the absorbent article having the absorbent body having such a structure, moisture reaches the absorbent body through the fine holes formed in the top sheet. In the absorbent body, water is diffused by the pair of outer nonwoven fabrics and the inner nonwoven fabric and absorbed into the particulate matter.

Documents of the prior art

Patent document

Patent document 1: chinese patent No. 101491472B

Patent document 2: chinese Utility model No. CN206007482U

Disclosure of Invention

Problems to be solved by the invention

For an absorbent article, good feeling in use and bulkiness are desired. However, in the case of the absorbent article having the above-described configuration, there is a fear that the touch may be reduced due to the water after the water absorption leaching out to the surface of the absorbent article (hereinafter, referred to as rewetting). Further, the thickness is relatively thin, the wearing feeling is not excellent, and the feeling of comfort given to the user is not sufficient.

Therefore, an object of the present invention is to provide an absorbent article having an absorbent body in which water-absorbent particulate matter is dispersed and disposed, in which rewetting is suppressed, and which has a good feel during use and can maintain a bulky state.

Means for solving the problems

In order to solve the above problem, an absorber according to an aspect of the present invention includes: a base sheet formed of a nonwoven fabric; a core disposed above the base sheet; and water-absorbing particles dispersed and disposed between the base sheet and the core, wherein the core is formed of a tow band in which long fibers of a cellulose acetate tow are crimped and opened.

According to the above configuration, since the core is formed of the tow band in which the long fibers of the cellulose acetate tow are curled and opened, the water absorbed by the absorbent can pass through the core through the abundant fiber gaps formed in the core, and the particulate matter can be efficiently absorbed. This makes it possible to quickly move the water from the surface of the core body on the side opposite to the base sheet side to the granular material, and also to prevent the water from remaining around the granular material, thereby greatly preventing rewetting.

Further, since the core has a good bulkiness because the long fibers of the cellulose acetate tow are curled and opened, even if the absorbent body is compressed during use or the absorbent body absorbs water, the core can prevent the absorbent body from being greatly reduced in volume, and can exhibit a soft feel and cushioning properties.

Further, since the particulate matter is disposed between the core and the base sheet, the surface of the core opposite to the particulate matter side has good liquid releasability, and a dry touch can be maintained even after water absorption. Further, since the thickness of the absorbent body can be increased, excellent wearing feeling can be obtained, and a sufficient feeling of comfort can be given to the user.

The core may be sheet-shaped and arranged to overlap the base sheet. By forming the core in a sheet-like shape in this manner, excellent tactile sensation can be obtained over a wide area of the absorbent body even in use due to the favorable bulkiness of the core.

The grammage of the tow band in the core may be set to a value in a range of 15gsm (grams per square meter) or more and 150gsm or less. This can increase the compression energy of the core, and can make the absorbent body more favorably exhibit favorable bulkiness and soft feeling.

The sheet may further include a liquid-permeable sheet disposed between the base sheet and the core, and the particulate matter may be disposed between the base sheet and the liquid-permeable sheet and between the liquid-permeable sheet and the core. Even when such a liquid-permeable sheet is provided, rewet of the absorbent body can be favorably prevented, and a bulky state can be maintained. Further, since the granular materials are disposed between the base sheet and the liquid-permeable sheet and between the liquid-permeable sheet and the core, moisture can be dispersed and absorbed in the granular materials disposed on both sides of the liquid-permeable sheet in the thickness direction by allowing moisture to pass through the liquid-permeable sheet, and the granular materials can be efficiently absorbed.

An absorbent article according to an aspect of the present invention includes: any of the above-described absorbers; a back sheet disposed so as to overlap the base sheet on a side opposite to the core; and a top sheet disposed so as to overlap the core on the side opposite to the base sheet.

According to the above configuration, by using the absorbent body formed of the tow band in which long fibers of a cellulose acetate tow are curled and opened, rewetting in the absorbent article can be prevented, and a large reduction in volume of the absorbent body in use can be prevented.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the aspects of the present invention, rewetting is suppressed in an absorbent article including an absorbent body in which water-absorbing particulate matter is dispersed, so that the feeling during use is good and a bulky state can be maintained.

Drawings

Fig. 1 is a schematic view of an absorbent body manufacturing apparatus according to embodiment 1.

FIG. 2 is a vertical cross-sectional view of an absorbent body obtained by the apparatus of FIG. 1, as seen in the transport direction.

Fig. 3 is a vertical sectional view of an absorbent article provided with the absorbent body of fig. 2.

Fig. 4 is a vertical sectional view of the absorbent body of embodiment 2 as seen from the transport direction.

FIG. 5 is a vertical sectional view of an absorbent body of a comparative example viewed in the transport direction.

Detailed Description

Hereinafter, each embodiment will be described with reference to the drawings. The upstream side mentioned below refers to the upstream side of the tow band 40 in the conveying direction P, and the downstream side refers to the downstream side of the tow band 40 in the conveying direction P.

(embodiment 1)

[ absorbent body manufacturing apparatus ]

Fig. 1 is a schematic diagram of an absorbent body manufacturing apparatus 1 according to embodiment 1 (hereinafter, simply referred to as a manufacturing apparatus 1). As shown in fig. 1, a packing container 50 is disposed near the manufacturing apparatus 1. In the packing container 50, the tow band 40 including a plurality of fibers is folded into a bundle shape, and is compressed and packed. The bale receptacle 50 of fig. 1 shows a cross-sectional configuration.

The fibers contained in the tow band 40 are long fibers of crimped cellulose acetate tow. TD of the tow band 40 may be set as appropriate, and is set to a value in the range of 6000 to 60000, for example. The FD of the tow band 40 may be set as appropriate, and is set to a value in the range of 1 to 20, for example. In the manufacturing apparatus 1 of the present embodiment, the tow band 40 is conveyed in the predetermined conveying direction P while being held horizontally in the width direction. The TD and the grammage of the tow band 40 can be adjusted by cutting the tow band 40 during conveyance to a predetermined width as disclosed in japanese patent application laid-open No. 2014-221961, for example.

The manufacturing apparatus 1 includes a 1 st manufacturing unit 2 and a 2 nd manufacturing unit 3. The 1 st manufacturing part 2 includes: a 1 st spreader 4, a guide 5, a 2 nd spreader 6, a 1 st opening roller pair 7, a 2 nd opening roller pair 8, an opening device 9, and a feeding roller pair 10.

The 1 st tenter 4 tenters the tow band 40 lifted from the inside of the bale case 50 in the width direction. The guide 5 guides the tow band 40 passing through the 1 st tenter 4 toward the 2 nd tenter 6. The 2 nd tentering device 6 further tenters the tow band 40 passing through the guide 5 in the width direction. For example, the 1 st spreader 4 and the 2 nd spreader 6 have the same configuration.

The 1 st opening roller pair 7 and the 2 nd opening roller pair 8 further open the tow band 40 passed through the 2 nd spreading device 6 at the upstream side of the opening device 9. The 2 nd opening roller pair 8 is disposed downstream of the 1 st opening roller pair 7. The 1 st opening roller pair 7 has a pair of rollers 14 and 15 arranged so that their circumferential surfaces face each other. The 2 nd opening roller pair 8 has a pair of rollers 16 and 17 arranged so that their circumferential surfaces face each other. The rollers 16, 17 rotate at a peripheral speed faster than that of the rollers 14, 15.

The tow band 40 passed through the second tenter 6 is inserted between the pair of rollers 14 and 15 and between the pair of rollers 16 and 17. The tow band 40 is tensioned in the conveying direction P by contacting with the circumferential surfaces of the rollers 14 to 17, and is fluffy opened.

The opening device 9 opens the tow band 40 passing through the 2 nd opening roller pair 8. The method of opening tow band 40 in opening device 9 is not limited. The conveying roller pair 10 has conveying

rollers

23 and 24 arranged so that their circumferential surfaces face each other. The tow band 40 passed through the fiber-opening device 9 is inserted between the

transport rollers

23 and 24, and is pressed in the thickness direction by the

transport rollers

23 and 24. Thereby manufacturing the sheet-like core 41. The core 41 is conveyed to the 2 nd manufacturing unit 3 while being guided by the guide roller 13.

In the 2 nd manufacturing unit 3, the core 41 and the base sheet 42 are arranged to overlap each other with the particulate matter 45 interposed therebetween. The 2 nd manufacturing part 3 has: a feeding device 11, a sheet conveying device 25, an adding device 30, and a sheet forming roller pair 32.

The feeding device 11 lifts the strip-shaped base sheet 42 from the base sheet roll R1 and feeds the base sheet onto the conveying line L. The sheet conveying device 25 conveys the base sheet 42 fed by the feeding device 11 along the conveying line L. The adding device 30 adds the particulate matter 45 to the base sheet 42 in the line L. An adhesive is applied to the surface of the base sheet 42 that contacts the particulate matter 45, and the particulate matter 45 is fixed to the base sheet 42 by the adhesive. The core 41 is fed to the base sheet 42 to which the particulate matter 45 is added.

The base sheet 42, the particulate matter 45, and the core 41 pass between the

rollers

26, 27 of the sheet forming roller pair 32. Here, the base sheet 42 is formed of a nonwoven fabric having air permeability and liquid permeability. The base sheet 42 has a network structure in which short fibers are bonded. The short fibers are formed of synthetic fibers, for example. In the manufacturing apparatus 1, the base sheet 42 and the core 41 having passed through the

rollers

26 and 27 are cut into a predetermined size, thereby manufacturing the absorbent body 44.

[ absorbent body and absorbent article ]

Fig. 2 is a vertical sectional view seen from the transport direction P of the absorbent body 44 obtained by the manufacturing apparatus 1 of fig. 1. As shown in fig. 2, the absorber 44 includes: a base sheet 42, a core 41, and a particulate matter 45. The core 41 is disposed above the base sheet 42. The particulate matter 45 is disposed so as to be dispersed between the base sheet 42 and the core 41. That is, the particulate matter 45 is unevenly present on the lower surface side of the core 41 in the absorber 44 rather than on the upper surface side of the core 41. In other words, the particulate matter 45 is covered with the core 41.

The core 41 is sheet-shaped and is disposed to overlap the base sheet 42. The core 41 is formed of a tow band 40 obtained by crimping and opening long fibers of a cellulose acetate tow.

Fig. 3 is a vertical sectional view of an absorbent article 46 provided with the absorbent body 44 of fig. 2. As shown in fig. 3, the absorbent article 46 includes an absorber 44, a top sheet 47, and a back sheet 48. The back sheet 48 has air permeability and is arranged to overlap with the base sheet 42 on the side opposite to the core 41. The top sheet 47 has air permeability and liquid permeability, and is disposed on the opposite side of the core 41 from the base sheet 42. In the absorbent article 46, the particulate matter 45 is not disposed between the core 41 and the top sheet 47. Therefore, the core 41 is in contact with the top sheet 47 in a state not separately covered with the nonwoven fabric, for example.

The grammage of the tow band 40 in the core 41 can be set as appropriate depending on, for example, the thickness dimensions of the absorbent body 44 and the absorbent article 46 to be produced, and in the present embodiment, is set to a value in the range of 15gsm to 150gsm, as an example. The grammage is, for example, more preferably in the range of 30gsm to 110gsm, and still more preferably in the range of 40gsm to 170 gsm.

As described above, according to the absorbent 44, since the core 41 is formed of the tow band 40 obtained by winding and opening the long fibers of the cellulose acetate tow, the moisture absorbed by the absorbent 44 can pass through the core 41 through the abundant fiber gaps formed in the core 41, and can pass through the inside of the core 41, and the particulate matter 45 can be efficiently absorbed by water. This makes it possible to quickly move the water from the surface of the core 41 on the side opposite to the base sheet 42 to the granular material 45, and to prevent the water from remaining around the granular material 45, thereby greatly preventing rewetting.

Further, since the core 41 has excellent bulkiness because the long fibers of the cellulose acetate tow are curled and opened, even if the absorbent body 44 is compressed during use or the absorbent body 44 absorbs water, the volume of the absorbent body 44 can be prevented from being greatly reduced, and a soft touch and good cushioning properties can be exhibited.

Further, since the particulate matter 45 is disposed between the core 41 and the base sheet 42, the surface of the core 41 opposite to the particulate matter 45 side has good liquid releasing properties, and a dry touch feeling can be maintained even after water absorption. Further, since the thickness of the absorber 44 can be increased, excellent wearing feeling can be obtained, and a sufficient feeling of comfort can be given to the user.

Further, since the core 41 has a network structure formed by winding long fibers of a cellulose acetate tow, for example, the network structure can be formed without fusing the fibers to each other or bonding the fibers to each other with an adhesive. Therefore, the core 41 has a large fiber space and excellent liquid diffusibility. In addition, the core 41 is made of cellulose acetate tow, and thus has excellent hydrophilicity. Further, since the core 41 is formed by passing the tow band 40 through the fiber opening device 9, it can be formed without welding or bonding the fibers to each other.

In the absorbent 44, the particulate matter 45 is supported by the base sheet 42 between the core 41 and the base sheet 42. Therefore, for example, the particulate matter 45 may not be supported in the fiber gap formed by fusing or bonding the fibers of the lower portion of the core 41 to each other. In addition, since the fiber gap of the core 41 can be made non-constant in this way, the core 41 can maintain good touch and bulkiness.

Further, since the core 41 is in a sheet shape and is disposed so as to overlap the base sheet 42, excellent tactile sensation can be obtained over a wide area of the absorbent body 44 even in use due to the favorable bulkiness of the core 41.

Further, since the grammage of the tow band 40 in the core 41 is set to a value in the range of 15gsm to 150gsm, the compression energy of the core 41 can be increased, and the absorbent body 44 can be made to exhibit a favorable bulk and a soft feel more favorably. Here, the compression energy means an average per 1cm at the time of compression²The energy absorbed by the surface. The larger the value of the compression energy, the easier the compression is performed, and can be evaluated as soft.

The absorbent article 46 further includes: an absorbent body 44, a back sheet 48 disposed so as to overlap the base sheet 42 on the side opposite to the core 41, and a top sheet 47 disposed so as to overlap the core 41 on the side opposite to the base sheet 42. In this way, by using the absorber 44 formed of the tow band 40 obtained by crimping and opening long fibers of a cellulose acetate tow, rewetting can be prevented, and the volume of the absorber 44 in use can be prevented from being greatly reduced. The core 41 may have a fiber network structure formed by dissolving fibers with a binder such as triacetin. Hereinafter, embodiment 2 will be described with respect to differences from embodiment 1.

(embodiment 2)

Fig. 4 is a vertical sectional view of the absorbent body 144 of embodiment 2 as viewed in the transport direction. As shown in fig. 4, the absorbent body 144 includes a liquid-permeable sheet 43 disposed between the base sheet 42 and the core 41. The particulate matter 45 is disposed between the base sheet 42 and the liquid-permeable sheet 43, and between the liquid-permeable sheet 43 and the core 41. The liquid-permeable sheet 43 has a network structure in which short fibers are bonded. For example, the liquid-permeable sheet 43 is formed of the same sheet as the base sheet 42.

Even when such a liquid-permeable sheet 43 is provided, rewetting of the absorbent body 144 can be prevented satisfactorily, and a bulky state can be maintained. Further, since the granular substances 45 are disposed between the base sheet 42 and the liquid-permeable sheet 43 and between the liquid-permeable sheet 43 and the core 41, by allowing moisture to permeate through the liquid-permeable sheet 43, moisture can be dispersed and absorbed in the granular substances 45 disposed on both sides of the liquid-permeable sheet 43 in the thickness direction, and the granular substances 45 can absorb water more efficiently.

Further, by configuring the liquid-permeable sheet 43 to have a network structure, moisture is rapidly circulated through the liquid-permeable sheet 43, and the particulate matter 45 can be easily and uniformly absorbed with water.

(confirmation test)

Next, the confirmation test will be described, but the present invention is not limited to the examples shown below. The absorbent body 44 according to example was manufactured using the manufacturing apparatus 1 described in embodiment 1.

Fig. 5 is a vertical sectional view seen from the conveyance direction of the absorber 244 of the comparative example. As shown in fig. 5, a sheet-like core 141 having a network structure formed by welding short fibers having a two-layer structure of a core made of PE (polyethylene) and a covering made of PET (polyethylene terephthalate) is used as the core. The core 141 has a lower density than the base sheet 42, and is set to have the same density as the core 41 in the absorbent body 44 of the example.

A nonwoven fabric sheet 49 similar to the base sheet 42 is arranged above the core 141. The absorbent body 244 according to the comparative example was produced under the same production conditions as in the examples, except that the particulate matter 45 was disposed between the base sheet 42 and the core 141 and between the core 141 and the nonwoven fabric sheet 49. The absorbent body 44 of the example and the absorbent body 244 of the comparative example were evaluated for the water absorption rate, rewet amount, and compression energy by the following procedure.

[ Water absorption Rate ]

The

absorber

44, 244 is disposed in a U shape in plan view, and 80cc of physiological saline is dropped onto the

absorber

44, 244 in a state where a constant load (5kg) is applied to the

absorber

44, 244. At this time, the time required for the

absorbent body

44, 244 to completely absorb water was measured as the water absorption rate at the time of the 1 st water absorption. After measuring the rewet amount described later, 80cc of physiological saline was dropped onto the

absorbent member

44 or 244 for the 2 nd time, and the time required for the

absorbent member

44 or 244 to completely absorb water was measured as the water absorption rate at the 2 nd time of water absorption.

[ rewet amount ]

In the measurement of the 1 st water absorption at the water absorption rate, after 5 minutes of dropping physiological saline, the filter paper and a weight of a predetermined weight (3.5kg) were placed on the

absorber

44 or 244, and the weight of the liquid absorbed by the filter paper in 3 minutes was measured as the 1 st rewet amount. Further, the weight of the liquid was measured, and after the 2 nd normal saline was dropped at the time of the measurement of the water absorption rate, the 2 nd rewet amount was measured by the same method as the method for measuring the 1 st rewet amount.

[ compression energy ]

The compression energy of the

absorbers

44 and 244 of the comparative examples and examples was measured using a touch feeling measuring instrument "KES-G5" manufactured by KATO TECH co. In this measurement, the compression deformation rate was 0.1mm/sec, and the upper limit load was 50g/cm²The area of the pressurizing plate is 2cm²Under the set conditions of (3), the

absorber

44, 144 is compressively deformed from the surface in the thickness direction by the pressing plate at a constant speed up to the upper limit load. The value measured at this time was taken as compression energy. The measurement results are shown in table 1.

[ Table 1]

As shown in table 1, it was confirmed that: the absorbent body 44 of the example has a slightly lower water absorption rate for the 1 st and 2 nd times than the absorbent body 244 of the comparative example, and can absorb water for a longer period of time. In addition, it was confirmed that: the absorbent body 44 of the example had a much smaller rewet amount at the time of 1 st absorption than the absorbent body 244 of the comparative example, and the rewet amount at the time of 2 nd absorption could be maintained to be the same as the absorbent body 244 of the comparative example. It is also understood that the compression energy of the absorber 44 of the example is much larger than that of the absorber 244 of the comparative example.

When the appearances of the absorber 44 of the example and the absorber 244 of the comparative example were visually observed, it was found that: the absorbent body 244 of the comparative example, although including the base sheet 42, the core 141, and the nonwoven fabric sheet 49, was significantly thinner than the absorbent body 44 of the example, but the absorbent body 44 of the example was thicker than the absorbent body 244 of the comparative example, and was also comfortable from the viewpoint of wearability and water absorption performance.

The reason why the absorbent body 44 of the example can suppress the amount of rewet and has a large compression energy as compared with the absorbent body 244 of the comparative example is considered that, for example, the core body 41 of the example is bulkier and softer than the core body 141 of the comparative example.

In the example, it is considered that the moisture passes through the fiber gaps of the long fibers of the acetate tow in the core 41 and diffuses in the core 41, so that the liquid releasing property of the surface of the core 41 opposite to the base sheet 42 side is good, and the particulate matter 45 disposed between the core 41 and the base sheet 42 absorbs water efficiently, whereby the amount of moisture remaining around the particulate matter 45 is reduced as compared with the comparative example.

In contrast, it is considered that: in the comparative example, the liquid diffusibility of the core 141 was lower than that of the core 41 of the example, and therefore, the particulate matter 45 could not be sufficiently absorbed water, and the rewet amount at the 1 st time was increased as compared with the example.

The present invention is not limited to the embodiments, and the configurations and methods thereof may be changed, added, or deleted without departing from the scope of the present invention. In the absorber 44, 2 or more sheets of the core 41 may be arranged above the base sheet 42. For example, by arranging more than 2 sheets of the cores 41 so as to overlap each other, the grammage of the tow band 40 in the cores 41 can be increased, and the bulkiness (thickness) of the absorber 44 and the absorbent article 46 can be easily increased.

Further, by cutting the tow band 40 to a predetermined width, the grammage of the tow band 40 in the core 41 can be reduced, and the bulkiness (thickness) of the absorbent body 44 and the absorbent article 46 can be easily reduced.

Industrial applicability

As described above, according to the present invention, an absorbent article including an absorbent body in which water-absorbing particulate matter is dispersed and disposed has an excellent effect that rewetting is suppressed, and that the article has a good feeling during use and can maintain a bulky state. Therefore, the present invention is useful when widely used as an absorbent body and an absorbent article that can exhibit the effect.

Description of the reference numerals

41 core body

42 base sheet

43 liquid-permeable sheet

44. 144 absorbent body

45 granular material

46 absorbent article

47 Top sheet

48 Back sheet

Claims

1. An absorbent body, comprising:

a base sheet formed of a nonwoven fabric;

a core disposed above the base sheet; and

water-absorbing particles dispersed and disposed between the base sheet and the core,

the core is formed of tow band obtained by crimping and opening long fibers of cellulose acetate tow.

2. The absorbent body according to claim 1, wherein the core is sheet-shaped and arranged to overlap with the base sheet.

3. The absorbent body according to claim 1 or 2, wherein the grammage of the tow band in the core is set to a value in a range of 15gsm or more and 150gsm or less.

4. The absorbent body according to any one of claims 1 to 3, further comprising a liquid-permeable sheet disposed between the base sheet and the core,

the particulates are disposed between the base sheet and the liquid-permeable sheet, and between the liquid-permeable sheet and the core.

5. An absorbent article comprising:

an absorbent body according to any one of claims 1 to 4;

a back sheet disposed so as to overlap with a side of the base sheet opposite to the core; and

a top sheet disposed to overlap a side of the core opposite the base sheet.