Absorbent material and method for manufacturing the same
By expanding materials with slits to form through holes, the absorbent reduces material usage while maintaining performance, addressing the need for cost-effective absorbent production without quality compromise.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- ZUIKO CORP
- Filing Date
- 2025-01-16
- Publication Date
- 2026-07-29
AI Technical Summary
The rising material costs necessitate a reduction in the amount of materials used in absorbent products without compromising their quality.
The absorbent is configured with slits formed in materials like the top sheet, liquid-diffusing sheet, and absorbent core, which are then expanded in directions intersecting the slits to create through holes, allowing these components to cover a larger area with reduced material usage while maintaining or improving quality.
This configuration reduces material usage without deteriorating the absorbent's performance, as the through holes enable effective liquid absorption and diffusion, preventing leakage and maintaining quality.
Smart Images
Figure 2026122857000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an absorber and a method for manufacturing the same, and more particularly, to an absorber used for absorbing body fluids and the like in disposable diapers, sanitary napkins, and other wearing articles, and a method for manufacturing the same.
Background Art
[0002] FIG. 9 is a longitudinal front explanatory view of an absorbent article used in a wearing article. As shown in FIG. 9, an absorber body 101 has an absorbent core 104 having liquid absorbency disposed between a surface sheet 102 having liquid permeability and a back sheet 103 having liquid impermeability. A diffusion sheet 115 is joined to the upper surface of the absorber body 101, and a permeable upper surface sheet 116 is joined to the upper surface of the diffusion sheet 115 (see, for example, Patent Document 1).
[0003] FIG. 10 is an exploded perspective view of an incontinence shield 200. As shown in FIG. 10, the incontinence shield 200 has an absorbent core 209 enclosed between a top sheet 207 having liquid permeability and a back sheet 208 having liquid impermeability, and an inlet material 201 is disposed between the top sheet 207 and the absorbent core 209.
[0004] FIG. 11 is a plan view of the inlet material 201 before being expanded. FIG. 12 is a plan view of the inlet material 201 after being expanded. As shown in FIG. 11, the inlet material 201 forms a slit 202 extending in the lateral direction, and then, as shown in FIG. 12, is expanded in the lateral direction with respect to the direction of the slit 202 to form an opening 203 in which the slit 202 is opened, and then is disposed at a predetermined position.
[0005] As shown in FIGS. 10 to 12, the slit 202 and the opening 203 are formed only in the central region 204 of the inlet material 201, and are not formed in the edge regions 205 and 206 of the inlet material 201. Therefore, the edge regions 205 and 206 of the inlet material 201 have greater elasticity than the central region 204.
[0006] Figure 13 is an explanatory diagram of the incontinence shield 200 as seen from the user's perspective when worn. As shown in Figure 11, the incontinence shield 200 takes on a bowl shape when worn due to the elastic contraction of the edge regions 205 and 206 (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]
[0007] [Patent Document 1] Patent No. 3474497 [Patent Document 2] Patent No. 6580717 [Overview of the project] [Problems that the invention aims to solve]
[0008] In recent years, material prices have soared, making it necessary to reduce the amount of materials used. In doing so, it is desirable that the quality of the absorbent material does not deteriorate.
[0009] In view of these circumstances, the problem that the present invention aims to solve is to provide an absorbent and a method for manufacturing the same that can reduce the amount of materials used without causing a deterioration in the quality of the absorbent. [Means for solving the problem]
[0010] To solve the above problems, the present invention provides an absorbent configured as follows.
[0011] The absorbent body comprises (a) a liquid-permeable top sheet, (b) a liquid-impermeable back sheet, (c) a liquid-absorbing absorbent core disposed between the top sheet and the back sheet, and (d) a liquid-permeable liquid-diffusing sheet disposed between the top sheet and the absorbent core, wherein at least one of the top sheet, the liquid-diffusing sheet, and the absorbent core is made of a material that has a slit formed through its main surfaces and then widened in a direction intersecting the slit, and has a through hole formed by widening the slit.
[0012] According to the above configuration, the spread-out material can be placed over a larger area than the material before spreading, thus reducing the amount of material used. Since the top sheet and liquid diffusion sheet need to permeate the liquid, even if the top sheet and / or liquid diffusion sheet have through holes, this can be prevented from causing a deterioration in the quality of the absorber. Even if the absorption core has through holes, it can absorb the liquid from the inner surface of the through holes, thus preventing a deterioration in the quality of the absorber.
[0013] Preferably, the absorbent further comprises a breathable outer sheet attached to the main surface of the backsheet opposite to the absorbent core, wherein, instead of or in addition to at least one of the above, the outer sheet is made of a material which is widened in a direction intersecting the slit after a slit is formed penetrating between the main surfaces, and the slit has a widened through-hole.
[0014] Preferably, (i) the liquid diffusion sheet has the through-hole, and (ii) the liquid diffusion sheet is arranged with a gap between it and the outer edge of the absorbent core in a plan view.
[0015] In this case, even if the amount of material used in the liquid diffusion sheet is reduced, it is possible to avoid a deterioration in the quality of the absorbent.
[0016] Furthermore, in order to solve the above problems, the present invention provides a method for manufacturing an absorbent configured as follows.
[0017] A method for manufacturing an absorbent is to form at least one of the top sheet, absorbent core, liquid diffusion sheet, and outer sheet constituting the absorbent by a process including (i) transporting a base sheet for forming the one; (ii) forming a slit in the transported base sheet; and (iii) spreading the base sheet in a direction intersecting the extending direction of the slit to form a through hole through which the slit has been widened.
[0018] According to the above method, the base sheet used for at least one of the topsheet, the liquid diffusion sheet, and the absorbent core is formed using the expanded base sheet. The expanded base sheet can be arranged in a larger area compared to the base sheet before expansion, and the amount of the base sheet used can be reduced.
[0019] In the above method, the direction in which the slit is formed in the base sheet may be parallel to the conveyance direction of the base sheet or may intersect the conveyance direction of the base sheet. Also, the direction in which the base sheet is expanded may be parallel to the conveyance direction of the base sheet or may intersect the conveyance direction of the base sheet.
Advantages of the Invention
[0020] According to the present invention, it is possible to reduce the amount of materials used without causing a deterioration in the quality of the absorber.
Brief Description of the Drawings
[0021] [[ID=]] [[ID=]] [Figure 1] FIG. 1 is a schematic view of the absorber seen through perpendicularly to the surface. [Figure 2] FIG. 2 is a plan schematic view of a wearing article using an absorber of another embodiment. [Figure 3] FIG. 3(a) is a schematic view of another embodiment of the expanded absorber seen through perpendicularly to the surface, and FIG. 3(b) is an exploded cross-sectional schematic view along line B-B of another embodiment. [Figure 4] FIG. 4 is a schematic view showing the manufacturing process of the liquid diffusion sheet. [Figure 5] FIG. 5 is a photograph of a sample after the coloring liquid is supplied. [Figure 6] FIG. 6 is a graph showing the experimental results of the liquid absorption characteristics. [Figure 7] FIG. 7 is a graph showing the experimental results of the liquid return characteristics. [Figure 8] FIG. 8 is an exploded cross-sectional schematic view of an absorber of another example. [Figure 9] FIG. is a longitudinal front explanatory view of an absorbent article. (Conventional Example 1) [Figure 10] Figure 10 is a disassembled perspective view of an incontinence shield. (Conventional example 2) [Figure 11] Figure 11 is a top view of the inlet material before it is expanded. (Conventional Example 2) [Figure 12] Figure 12 is a top view of the inlet material after it has been spread out. (Conventional Example 2) [Figure 13] Figure 13 shows the incontinence seal as seen from the user's perspective when worn. (Conventional Example 2) [Modes for carrying out the invention]
[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023] <Example 1> The absorber 10 of Example 1 will be described with reference to Figures 1 to 7.
[0024] Figure 1 is a schematic diagram of the absorbent viewed perpendicularly to the surface, Figure 2 is a schematic plan view of a wearable article using another embodiment of the absorbent, Figure 3(a) is a schematic diagram of the other embodiment of the absorbent viewed perpendicularly to the surface, and Figure 3(b) is an exploded cross-sectional view of the other embodiment along line BB.
[0025] Figure 1 shows the case in which the absorbent body 10 is used in an open / close type wearable item 20. Both ends of the absorbent body 10 are joined to the torso side member 22 and the ventral side member 24 of the disposable wearable item 20, such as a paper diaper, and when worn, fastening members 26 provided at both ends of the torso side member 22 are fastened to the ventral side member 24.
[0026] Figure 2 shows another embodiment of the absorbent material 10 used in a pants-type garment 21. The absorbent material 10 is folded in half along a fold line 10k, and both ends of the absorbent material 10 are joined to the torso member 22 and the ventral member 24. The torso member 22 and the ventral member 24 are joined to each other along their respective end edges 22a, 22b; 24a, 24b by hot melt bonding, heat sealing, sonic sealing, etc. Figure 3(a) shows the garment 21 in an unfolded state, that is, the joining of the torso member 22 and the ventral member 24 is released, and the folded absorbent material 10 is laid flat.
[0027] The absorbent material 10 alone may constitute a wearable item.
[0028] As shown in Figures 1 to 3, the absorbent 10 is constructed by laminating a liquid diffusion sheet 14 and an absorbent core 16 between a top sheet 12 and a back sheet 18. The top sheet 12 has the property of allowing liquid to pass through, i.e., liquid permeability. The back sheet 18 has the property of not allowing liquid to pass through, i.e., liquid impermeability.
[0029] The liquid diffusion sheet 14 is permeable to liquid and is placed between the top sheet 12 and the absorbent core 16. The absorbent core 16 is liquid absorbent and is made of, for example, fibers such as cotton or crushed pulp mixed with a superabsorbent polymer (SAP). When liquid supplied from the top sheet 12 side passes through the liquid diffusion sheet 14 and reaches the absorbent core 16, it is absorbed and retained by the absorbent core 16. It is preferable to form channels 19 in the absorbent core 16.
[0030] By providing the liquid diffusion sheet 14, the liquid is spread to the absorbable area of the absorbent core 16. As a result, the liquid is prevented from remaining in one part of the absorbent core 16 and leaking out, increasing the total amount of liquid absorbed by the absorbent core 16 and improving the quality of the absorbent material.
[0031] The liquid diffusion sheet 14 is made of, for example, a nonwoven fabric sheet, and through holes 14x are formed that penetrate between the main surfaces of the liquid diffusion sheet 14. Figures 1 to 3 conceptually illustrate the through holes 14x, but the through holes 14x are formed in appropriate numbers and at appropriate locations, with appropriate dimensions and shapes.
[0032] As shown in Figure 1, the liquid diffusion sheet 14 having through holes 14x can be positioned in close proximity to the outer edge 17 of the absorbent core 16 in a plan view. In this case, the liquid can diffuse throughout the entire absorbable region of the absorbent core 16, thereby allowing the absorbent core 16 to exhibit its original absorption performance.
[0033] Alternatively, as shown in Fig. 3(a), it may be arranged with a gap between the outer peripheral edge 17 of the absorbent core 16. In this case, even if the liquid diffusion sheet 14 is made as small as possible and the amount of material used for the liquid diffusion sheet 14 is reduced, it is possible to effectively prevent leakage and the like without causing a deterioration in the quality of the absorber.
[0034] Next, the process of manufacturing the liquid diffusion sheet 14 will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing the manufacturing process of the liquid diffusion sheet 14.
[0035] First, as shown in Fig. 4(a), a sheet-like continuous body 30, which is the material for forming the liquid diffusion sheet 14, is conveyed in the longitudinal direction of the continuous body 30, that is, in the MD direction indicated by the arrow 80.
[0036] Next, as shown in Fig. 4(b), a slit 32 penetrating between the main surfaces is formed in the conveyed continuous body 30 using a perforating cutter or the like. At this time, the slit 32 is formed, for example, parallel to the conveying direction of the continuous body 30.
[0037] Next, in Fig. 4(c), in the CD direction indicated by the arrow 82, that is, the width direction, the continuous body 30 with a width W0 is expanded to form an expanded continuous body 31 with a width W1 (W0 < W1). For example, when the slit 32 is formed parallel to the conveying direction of the continuous body 30, by using an expanding roll to expand the continuous body 30 in a direction orthogonal to the conveying direction, the slit 32 expands and a large open through-hole 34 is formed.
[0038] Next, the expanded continuous body 31 is cut to form the liquid diffusion sheet 14.
[0039] Although not shown, a slit 30 extending in a direction (including the CD direction orthogonal to the MD direction) intersecting the conveying direction (MD direction) of the continuous body 30 may be formed, and then, by providing a difference in the conveying speed or the like, the continuous body 30 is stretched in the conveying direction (MD direction) to form a through-hole 34 in which the slit 32 has expanded.
[0040] Next, we will explain the experimental results of investigating the effect of a liquid diffusion sheet 14 having widened through-holes 14x, referring to Figures 5 to 7.
[0041] A widened sample was prepared by expanding a 65mm wide material with slits to 100mm in the width direction, and placing the liquid diffusion sheet 14, which has widened through-holes 14x, on top of an absorbent core with a single channel. For comparison, a comparative sample was prepared by placing a normal, unwidened liquid diffusion sheet with a width of 100mm on top of an absorbent core with a single channel. 150ml of colored liquid was supplied four times onto the liquid diffusion sheet of each sample.
[0042] Figure 5 is a photograph of the sample after the coloring solution has been supplied. From Figure 5, it can be seen that the coloring solution spreads and is absorbed into the absorbent core of the widened sample to the same extent as the comparison sample.
[0043] Figure 6 is a graph showing the experimental results of liquid absorption characteristics. In Figure 6, the vertical axis represents the time (absorption time) it takes for 150 ml of colored liquid to be absorbed by the absorbent core and disappear from the liquid permeable sheet. As shown in Figure 6, the widened sample has a shorter absorption time compared to the comparison sample, and the liquid absorption characteristics remain almost constant even when the number of times the colored liquid is supplied increases. The comparison sample has a longer absorption time compared to the widened sample, and the absorption time increases as the number of times the colored liquid is supplied increases.
[0044] Figure 7 is a graph showing the experimental results of the liquid return characteristics. In Figure 7, the vertical axis shows the results of measuring the weight of the colored liquid absorbed by the sheet (amount of liquid return) when a sheet was placed on top of a sample that had absorbed 150 ml of colored liquid. From Figure 7, it can be seen that the widened sample had less liquid return than the comparison sample.
[0045] As explained above, by using a liquid diffusion sheet 14 having widened through-holes 14x, the width of the material used for the liquid diffusion sheet can be reduced, thereby reducing the amount of material used for the liquid diffusion sheet. Furthermore, even if the amount of material used for the liquid diffusion sheet is reduced, it does not lead to a decrease in the quality of the absorber; on the contrary, the quality is improved.
[0046] Furthermore, by using a liquid diffusion sheet 14 having widened through-holes 14x, it is possible to maintain performance equivalent to that of conventional products even if the amount of material used in the absorbent core 16 is reduced. Therefore, a liquid diffusion sheet 14 having widened through-holes 14x can reduce not only the amount of material used in the liquid diffusion sheet 14, but also the amount of material used in the absorbent core 16.
[0047] <Example 2> Through-holes with widened slits may be formed in the absorbent core. Even if the absorbent core has through-holes, it can absorb liquid from the inner circumferential surface of the through-holes, thus preventing a deterioration in the quality of the absorbent material.
[0048] An absorbent core having a widened through-hole is manufactured, for example, by the following process:
[0049] The material for forming the absorbent core is transported, and then slits are made in the transported material using a perforation cutter or the like. Next, the material is widened using a widening roll so that the slits can be widened. Then, the width of the material is fixed using a heat seal or the like. Finally, hot melt adhesive is applied using a coater gun and the material is cut to the specified dimensions.
[0050] <Example 3> Through-holes with widened slits may be formed in the top sheet. Since the top sheet needs to permeate the liquid, having through-holes with widened slits in the top sheet can be done without causing a deterioration in the quality of the absorbent.
[0051] <Example 4> Figure 8 is a schematic cross-sectional view of an absorbent 10a, which is provided with a cover sheet 11 that covers the back sheet 18, similar to Figure 3(b).
[0052] As shown in Figure 8, the absorbent 10a is substantially the same as the absorbent 10 of Example 1, comprising a top sheet 12, a liquid diffusion sheet 14a, an absorbent core 16, and a back sheet 18. However, unlike the absorbent 10 of Example 1, it further comprises an outer sheet 11, and the liquid diffusion sheet 14a does not have through holes 14x with widened slits.
[0053] The outer sheet 11 has through holes 11x with widened slits, similar to the liquid diffusion sheet 14 of Example 1.
[0054] The outer sheet 11 is breathable and positioned on the opposite side of the back sheet 18 from the absorbent core 16. It is attached to the back sheet 18 at appropriate locations, covering the back sheet 18. By providing the outer sheet 11, which is the outermost layer on the non-skin side of the absorbent body 10a, the appearance of the absorbent body 10a can be improved, and the slipperiness between the absorbent body 10a and clothing during wear can be improved.
[0055] The outer sheet 11 is constructed, for example, similar to the liquid diffusion sheet 14 in Example 1, by forming slits in a continuous nonwoven fabric, then widening the continuous fabric to create a widened continuous body with through-holes formed by the widened slits. By constructing the outer sheet 11 using a material that has been widened to have through-holes with widened slits, the amount of material used for the outer sheet 11 can be reduced. In other words, the amount of material used for the absorbent body 10a can be reduced.
[0056] The back sheet 18 is preferably impermeable to liquids but also breathable. In this case, the outer sheet 11 has through holes 11x, which further improves breathability.
[0057] <Modification 1> A slit may be formed extending in a direction intersecting the material transport direction (MD direction) (including a direction perpendicular to the material transport direction (CD direction)), and then the material may be stretched in the transport direction (MD direction) to form a through hole with an expanded slit.
[0058] <Modification 2> The direction in which the material with the slit is spread may be a direction other than the direction in which the slit extends, such as a direction that intersects the direction in which the slit extends.
[0059] Furthermore, two or more of the above-described examples 1 to 4 and modifications 1 and 2 may be combined as appropriate. For example, two or more of the liquid permeable sheet 12, liquid diffusion sheet 14, absorbent core 16, and outer sheet 11 may have through holes with widened slits.
[0060] <Summary> As explained above, by forming slits in the material, then expanding the material in a direction intersecting the direction in which the slits extend, and using the expanded material with the expanded through-holes to form at least one of the absorbent's top sheet, liquid diffusion sheet, and absorbent core, it is possible to reduce the amount of absorbent material used while suppressing the deterioration of the absorbent's quality.
[0061] It should be noted that the present invention is not limited to the embodiments described above, and can be implemented with various modifications.
[0062] For example, the absorbent material may be provided with three-dimensional gathers or the like. Alternatively, the absorbent material alone may constitute a wearable item. [Explanation of Symbols]
[0063] 10,10a absorber 12 Top Sheets 14 Liquid Diffusion Sheet 14x through holes 16 Absorbent core 17 Outer edge 18 Backseat 19 channels 22 Body side member 24 Ventral member 26 Fastening members 30 continuum 31 Widening continuous section (materials) 32 slits 34 Through holes
Claims
1. A top sheet that is permeable to liquid, A back sheet that is impermeable to liquid, An absorbent core having liquid-absorbing properties is disposed between the top sheet and the back sheet, A liquid-permeable liquid diffusion sheet is disposed between the top sheet and the absorbent core, Equipped with, An absorbent body in which at least one of the top sheet, the liquid diffusion sheet, and the absorbent core is made of a material that has a slit formed through the main surfaces and then widened in a direction intersecting the slit, and the slit has a through hole formed by widening.
2. The back sheet further comprises a breathable outer sheet attached to the main surface of the back sheet opposite to the absorbent core, Instead of at least one of the above, or in addition to at least one of the above, The absorbent body according to claim 1, wherein the outer sheet is constructed using a material that has been widened in a direction intersecting the slits after slits have been formed penetrating between the main surfaces, and the slits have widened through holes.
3. The liquid diffusion sheet has the through-hole, The absorbent according to claim 1 or 2, wherein the liquid diffusion sheet is arranged in a plan view with a gap between it and the outer edge of the absorbent core.
4. At least one of the top sheet, the absorbent core, the liquid diffusion sheet, and the outer sheet constituting the absorbent according to claims 1 to 3, The steps include transporting a base sheet to form the said one, The steps include forming a slit in the conveyed base material sheet, The steps include: spreading the base sheet in a direction intersecting the extending direction of the slit to form a through hole in which the slit has been widened; A method for producing an absorbent by a process including the following.