Method for manufacturing an absorbent article

Abstract

In a method of manufacturing an absorbent article (1) having an absorbent core (132) and a non-skin side sheet (133), there is a slit forming process (S105) of forming a slit (18) on the non-skin side sheet (133) using a cutting roller (551) having a cutting edge (551c) protruding from a peripheral surface (551f) toward an outer side in a radial direction and an anvil roller (552) having a groove (552d) recessed from a peripheral surface (552f) toward an inner side in the radial direction, a part (cp) of the cutting edge (551c) presses the non-skin side sheet (133) toward the peripheral surface (552f) in a manner to form the slit (18), and another part (np) of the cutting edge (551c) presses the non-skin side sheet (133) toward the groove (552d) in a manner not to form the slit (18).

Description

Technical Field

[0001] This invention relates to a method for manufacturing absorbent articles. Background Technology

[0002] Previously known absorbent articles include labial pads that are worn in close contact with the labia. In such labial pads (absorbent articles), multiple slits are provided in a rigid component such as the absorbent body, allowing for easy three-dimensional deformation along the contours of the wearer's body, thereby improving fit during wear. For example, Patent Document 1 discloses a labial pad with multiple slits along the length or width of the article.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-97693 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the manufacturing process of labial pads (absorbent materials), the following method is generally used: when forming a slit in the absorbent material, a cutting roller and an anvil roller with multiple blades are used to press the absorbent material while clamping it in the thickness direction. However, in this method, the absorbent core after the slit is formed may adhere (press) to the blades of the cutting roller, easily causing a phenomenon known as "blade retention" where it is difficult to detach from the blades, which may reduce manufacturing efficiency.

[0008] The present invention was made in view of the above-mentioned problems, and its object is to suppress blade retention on the cutting roller when forming a slit in an absorbent article using a cutting roller and an anvil roller.

[0009] Solution for solving the problem

[0010] The main invention for achieving the above-mentioned objective is a method for manufacturing an absorbent article. This method involves manufacturing an absorbent article having an absorbent core and a non-skin side sheet disposed on a non-skin side in the thickness direction relative to the absorbent core. The method comprises: a transport step transporting the non-skin side sheet in a transport direction; a lamination step laminating the absorbent core onto the transported non-skin side sheet; and a slit-forming step, after the lamination step, forming a slit at least on the non-skin side sheet using a cutting roller and an anvil roller disposed opposite to the cutting roller. The cutting roller has a blade protruding outward from its circumferential surface in a radial direction, and the anvil roller has a groove recessed inward from its circumferential surface in a radial direction. A portion of the blade presses the absorbent core and the non-skin side sheet against the circumferential surface of the anvil roller in a manner that forms the slit, while another portion of the blade presses the absorbent core and the non-skin side sheet against the groove in a manner that does not form the slit.

[0011] Other features of the invention will become apparent from the description and accompanying drawings.

[0012] The effects of the invention

[0013] According to the present invention, when forming a slit on an absorbent article using a cutting roller and an anvil roller, blade retention on the cutting roller can be suppressed. Attached Figure Description

[0014] Figure 1 This is a top view of pad 1 in its unfolded state.

[0015] Figure 2 yes Figure 1 A-A direction outline sectional view.

[0016] Figure 3 is a diagram illustrating the structure of pad 1.

[0017] Figure 4 This is a diagram illustrating the structure of pad 1.

[0018] Figure 5 This is a top view illustrating the structure of the absorption layer 13.

[0019] Figure 6 It is a diagram showing the distribution of fiber lengths in hardwood absorbent fibers (hardwood pulp) and softwood absorbent fibers (softwood pulp).

[0020] Figure 7 This is a flowchart showing the manufacturing process of pad 1.

[0021] Figure 8This is a schematic diagram illustrating the manufacturing apparatus 500 for manufacturing absorbent articles such as pad 1.

[0022] Figures 9A-9C This is a diagram illustrating the configuration of the cutting roller 551 used in forming the first slit 18a.

[0023] Figures 10A-10B This diagram illustrates the configuration of the anvil roller 552 used to form the first slit 18a.

[0024] Figure 11 This diagram illustrates the action of forming the first slit 18a by the cutting roller 551 and the anvil roller 552.

[0025] Figure 12A as well as Figure 12B This diagram illustrates the situation where no groove is provided on the circumference of the anvil roller when forming a slit using a cutting roller and anvil roller.

[0026] Figure 13A as well as Figure 13B This diagram illustrates a scenario where a groove is provided on the circumferential surface of the anvil roller when a slit is formed using a cutting roller and anvil roller.

[0027] Figure 14 This is a diagram showing a variation of Figure 13.

[0028] Figures 15A-15C This diagram illustrates the configuration of the cutting roller 561 used in forming the second slit 18b.

[0029] Figure 16 This is a diagram illustrating a variation of the first slit forming mechanism 550. Detailed Implementation

[0030] The following will be understood from the description in this specification and the accompanying drawings.

[0031] (Method 1)

[0032] A method for manufacturing an absorbent article, the method comprising: a transport step, wherein the transport step transports the non-skin side sheet in a transport direction; a lamination step, wherein the lamination step laminations the absorbent core onto the transported non-skin side sheet; and a slit forming step, wherein after the lamination step, a slit is formed at least on the non-skin side sheet using a cutting roller and an anvil roller disposed opposite to the cutting roller, the cutting roller having a blade protruding outward from its circumferential surface in a radial direction, the anvil roller having a groove recessed inward from its circumferential surface in a radial direction, a portion of the blade pressing the absorbent core and the non-skin side sheet toward the circumferential surface of the anvil roller in a manner that forms the slit, and another portion of the blade pressing the absorbent core and the non-skin side sheet toward the groove in a manner that does not form the slit.

[0033] According to the method for manufacturing absorbent articles of method 1, when the cutting edge (another part) of the cutting roller presses against the groove of the anvil roller on the non-skin side sheet or other substrate, no slit is formed, thus making it difficult for the substrate to adhere to the cutting edge. Therefore, even if a slit is formed, if the substrate is attached to one part of the cutting edge, the other part will become a point where the substrate detaches, and the entire cutting edge easily falls off the substrate. As a result, it is difficult for the cutting edge to remain stuck.

[0034] (Method 2)

[0035] The method for manufacturing an absorbent article as described in Method 1 is characterized in that, in the slit-forming process, the blade presses the absorbent core and the non-skin side sheet from the side where the non-skin side sheet is provided toward the circumferential surface of the anvil roller in the thickness direction.

[0036] According to the absorbent article manufacturing method of Method 2, since the cutting roller presses (forming a cut) from the non-skin side sheet which has high rigidity and stable shape, the fibers are easily cut, and the cutting edge easily detaches from the substrate (non-skin side sheet) after the cut is formed. Therefore, compared with the case where the cutting edge is pressed from the skin side which has low rigidity, it is less likely for the cutting edge to remain stuck.

[0037] (Method 3)

[0038] The method for manufacturing an absorbent article as described in method 1 or 2 is characterized in that the absorbent article has at least: an absorbent layer comprising the absorbent core and the non-skin side sheet; and a layer disposed at a position closer to the skin side than the absorbent layer, wherein the absorbent layer has a shorter average fiber length and a finer average fiber diameter compared to the layer disposed at a position closer to the skin side than the absorbent layer.

[0039] According to the absorbent article manufacturing method of Method 3, in the absorbent layer with short fiber length and small diameter, the fibers tend to become denser, and the rigidity tends to be higher compared to the layer located on the skin side. Furthermore, by pressing the substrate with a blade from the side of the highly rigid absorbent layer (the non-skin side of the substrate) (forming a cut), the shape of the substrate is more easily maintained compared to the opposite case, and a neat slit can be formed.

[0040] (Method 4)

[0041] The method for manufacturing an absorbent article according to any one of methods 1 to 3 is characterized in that, in the width direction of the blade, the end of one side of the blade is located at the same position as the end of one side of the groove, or at a position closer to one side than the end of one side of the groove, and the end of the other side of the blade is located at the same position as the end of the other side of the groove, or at a position closer to another side than the end of the other side of the groove.

[0042] According to the absorbent article manufacturing method of Method 4, by pressing the substrate towards the circumferential surface of the anvil roller from the width-direction end of the blade, a short slit can be formed at the width-direction end. That is, by using a blade with a long width direction, blade wear and maintenance costs can be suppressed, and a short slit can be accurately formed. Furthermore, since the slit is not formed in the center of the blade's width direction, the substrate is difficult to adhere to the blade, thus preventing blade residue and easily forming a neat, short slit.

[0043] (Method 5)

[0044] The method for manufacturing an absorbent article according to any one of methods 1 to 4 is characterized in that the circumferential surface of the anvil roller and the boundary of the groove are chamfered.

[0045] According to the absorbent article manufacturing method of method 5, the boundary between the portion overlapping the circumference of the cutting roller and the anvil roller (the portion forming a slit) and the portion overlapping the groove (the portion not forming a slit) within the blade of the cutting roller changes gradually due to the force applied when the blade is pressed. Therefore, compared to the case where there is no chamfered portion, the substrate is less likely to adhere to the blade at the end of the slit, and blade retention is easily suppressed.

[0046] (Method 6)

[0047] The method for manufacturing an absorbent article according to any one of methods 1 to 5 is characterized in that the slit forming step comprises: a first slit forming step for forming a first slit along a direction orthogonal to the transport direction; and a second slit forming step for forming a second slit along the transport direction, wherein in the first slit forming step, a portion of the blade presses the absorbent core and the non-skin side sheet toward the circumferential surface of the anvil roller in such a manner as to form the first slit, and another portion of the blade presses the absorbent core and the non-skin side sheet toward the groove in such a manner as not to form the first slit.

[0048] According to the absorbent article manufacturing method of Method 6, since the blade forming the first slit is arranged along a direction orthogonal to the transport direction (CD direction), the portion that abuts against the circumferential surface of the anvil roller at a certain moment when the slit is formed becomes longer. Conversely, in the CD direction, a portion (another portion) of the blade is provided that presses against the groove of the anvil roller, thereby shortening the length of the portion of the blade that abuts against the circumferential surface of the anvil roller, making it less likely for the blade to become stuck. In addition, since it is less likely for the blade to become stuck, it is less likely for the shape of the substrate (absorbent layer, etc.) to be deformed.

[0049] (Method 7)

[0050] The method for manufacturing an absorbent article according to any one of methods 1 to 6 is characterized in that, in the first slit forming step, the blade is formed at a predetermined angle relative to a direction orthogonal to the transport direction.

[0051] According to the absorbent article manufacturing method of method 7, by arranging the blade at an angle relative to the direction orthogonal to the transport direction (CD direction), it is possible to prevent the entire width direction of the blade from contacting the circumferential surface of the anvil roller at the same time. As a result, the length of the portion of the blade pressing against the circumferential surface of the anvil roller is shortened, making it more difficult for the blade to become stuck.

[0052] (Method 8)

[0053] The method for manufacturing an absorbent article according to any one of methods 1 to 7 is characterized in that the absorbent article has intersecting front-back directions and width directions, the front-back direction being the direction along the transport direction, and in the first slit forming step, the blade forms the first slit in a manner opposite to the inclination of the first slit relative to the direction orthogonal to the transport direction, at a position one side closer to the center position of the absorbent article in the front-back direction and a position one side closer to the center position.

[0054] According to the method of manufacturing absorbent articles according to method 8, since the inclination direction of the first slit is opposite at the front and back of the central position of the absorbent article, the bending and deformation direction of the absorbent layer is also opposite at the front and back of the central position. Therefore, it is easy to make the absorbent article fit the concavity and convexity of the crotch of the wearer.

[0055] (Method 9)

[0056] The method for manufacturing an absorbent article according to any one of methods 1 to 8 is characterized in that the cutting roller used in the first slit forming step has a plurality of blades arranged discontinuously along the transport direction, and the anvil roller used in the first slit forming step has a groove that is continuous along the transport direction.

[0057] According to the absorbent article manufacturing method of Method 9, since the grooves of the anvil roller are continuously arranged along the transport direction (MD direction), it is not necessary to align the blade with the groove when pressing the cutting roller blade towards the groove. Therefore, the first slit can be formed with high precision.

[0058] (Method 10)

[0059] The method for manufacturing an absorbent article according to any one of methods 1 to 9 is characterized in that the absorbent article has intersecting front-back directions and width directions, and the anvil roller has the grooves at both ends of the absorbent article in the width direction.

[0060] According to the method for manufacturing an absorbent article of method 10, in the portion where the groove is provided, the substrate is difficult to adhere to the blade, and blade retention is unlikely to occur. Therefore, blade retention at both sides in the width direction (CD direction) of the absorbent layer can be easily suppressed. Thus, at both sides in the width direction of the absorbent layer, the blade can easily detach from the substrate (absorbent layer), and deformation of the absorbent layer from both sides can be suppressed.

[0061] (Method 11)

[0062] The method for manufacturing an absorbent article according to any one of methods 1 to 10 is characterized in that, at both ends of the absorbent article in the width direction, there is no portion where the first slit formed by the first slit forming process intersects with the second slit formed by the second slit forming process.

[0063] According to the method for manufacturing an absorbent article of method 11, since the first slit and the second slit at both ends in the width direction that abut against the labia do not intersect when the absorbent article is worn, the non-skin side panel can be prevented from rolling up towards the skin at the intersection. Therefore, it is possible to prevent the rolled-up non-skin side panel from irritating the wearer's labia or causing discomfort or imbalance in the wearer.

[0064] (Method 12)

[0065] The method for manufacturing an absorbent article according to any one of methods 1 to 11 is characterized in that the slit along the transport direction is formed in the second slit forming step in such a way that it overlaps with the portion of the blade that did not form the slit in the first slit forming step.

[0066] According to the absorbent article manufacturing method of method 12, a second slit is formed along the MD direction by overlapping the portion in the CD direction with the portion where the first slit is not formed, thereby enabling the formation of non-intersecting slits with low cost and high precision.

[0067] ===Implementation Methods===

[0068] The following description uses an interlabial pad 1 (hereinafter also referred to as "pad 1") as an example of an absorbent article related to the present invention to illustrate the embodiments. An interlabial pad is a physiological product inserted between a woman's labia to absorb menstrual blood and other excretions (body fluids). However, the absorbent articles related to the present invention are not limited to interlabial pads; for example, they may be urine-absorbing pads that come into contact with the urethra to absorb urine, or absorbent pads that come into contact with the anus to absorb feces, etc.

[0069] <Basic Composition of the Interlabial Pad 1>

[0070] Figure 1 This is a top view of pad 1 in its unfolded state. Figure 1 This is a picture viewed from the side of the skin on pad 1. Figure 2 yes Figure 1 A schematic cross-sectional view along line A-A. Figure 3 and Figure 4 This is a diagram illustrating the structure of pad 1. (Each diagram...) Figures 1-4 In the diagram, C-C represents the center in the width direction, and CL represents the center in the front-to-back direction of the absorption layer 13 (described later) when the pad 1 is viewed in the thickness direction. Additionally, Figure 1 as well as Figure 2 The diagram shows the state of inserting a finger into piece 15 (described later), cutting it at the center C-C, and placing pad 1 flat on a plane ("flat plane" state).

[0071] The pad 1 has mutually orthogonal front-back direction, width direction, and thickness direction. In the front-back direction of the pad 1, when worn, the side located on the wearer's abdomen is designated as the "front side", and the side located on the wearer's back is designated as the "back side". In addition, in the thickness direction of the pad 1, the side that contacts the wearer's skin is designated as the "skin side", and the opposite side is designated as the "non-skin side".

[0072] like Figures 1-4As shown, when viewed from above, pad 1 is approximately elliptical in shape, with its length in the front-to-back direction greater than its length in the width direction. It is symmetrical about its width center C-C, and its width length decreases as the center CL in the front-to-back direction tapers inwards towards the width center. Furthermore, when viewed from above, pad 1 is asymmetrical about its front-to-back center. Specifically, the center CL (the center of the absorber layer 13 in the front-to-back direction) is located rearwards compared to the center of the pad 1 in the front-to-back direction, and the distance from the front end of pad 1 to the front end of absorber layer 13 is greater than the distance from the rear end of pad 1 to the rear end of absorber layer 13. That is, in the front-to-back direction of pad 1, absorber layer 13 is positioned towards the rear. Figures 2-4 As shown, the pad 1 has a surface layer 11, a sub-absorbent layer 12, an absorbent layer 13, a back layer 14, and a finger insertion piece 15.

[0073] In this embodiment, the pad 1 is stored and distributed as a product bent with the fold line F facing the non-skin side. Figure 3 and Figure 4 This is a diagram illustrating the breakdown of pad 1 into its individual components. For example... Figure 3A As shown, in this embodiment, the pad 1 is bent along the central portion (central C-C) in the width direction, with the fold line F (bending line) bent towards the non-skin side. At the position closest to the non-skin side, a finger insertion piece 15 for forming the finger insertion portion 20 is fixed using an adhesive such as a hot melt adhesive HMA. The fold line F is a bend located in the central portion in the width direction along the front-back direction. The fold line F is a portion with a predetermined width, and the apex of the fold line F on the skin side (the portion protruding towards the skin side) is approximately at the same position as the central C-C in the width direction. Figure 3B This is the state in which the finger insertion piece 15 is separated from the back layer 14. Figure 3C This changes the position of the pad 1, from its bent state at fold F, to a horizontal state, where the finger insert 15 has been removed. Furthermore, from... Figure 3C From the state shown, as Figure 4 As shown, starting from the skin side in the thickness direction, a surface layer 11, a sub-absorbent layer 12, an absorbent layer 13, and a back layer 14 are sequentially overlapped, and at least a portion of these components are bonded to each other by an adhesive or the like (see Figure 14). Figure 2 ).

[0074] The surface layer 11 is located on the side closest to the skin and is the component that comes into contact with the wearer's skin (between the labia) during wear. Therefore, it is preferable to use a soft sheet that is unlikely to cause skin irritation. The surface layer 11 has the shape of the pad 1 and is a liquid-permeable sheet component. Examples of surface layer 11 include materials obtained by using nonwoven fabric alone or in combination with other nonwoven fabrics produced by methods such as meltblowing, spunbonding, dot bonding, hot air, needle punching, dry and wet hydroentangling, and foam film manufacturing. It can be a sheet component made of fibers obtained by using monomers or core-sheath structure composites of materials composed of rayon, acetate, cotton, pulp, or synthetic resins (e.g., polyethylene terephthalate: PET, polypropylene: PP, polyethylene: PE, etc.) alone or in combination. In this embodiment, the pad 1 is a sheet component made of rayon and polyethylene terephthalate.

[0075] The sub-absorbent layer 12 is located on the non-skin side compared to the surface layer 11, and on the skin side compared to the absorbent layer 13. Located between the surface layer 11 and the absorbent layer 13, the sub-absorbent layer 12 flexibly adapts to changes in the wearer's movements, labial movements, and pressure from clothing, changing its shape to act as a buffer layer that reduces discomfort for the wearer. The sub-absorbent layer 12 is approximately elliptical in shape, smaller than the surface layer 11, and located approximately in the center of the pad 1 (more precisely, towards the rear). Furthermore, the central CL of the sub-absorbent layer 12 in the front-to-back direction is recessed inward in the width direction, reducing its length in the width direction. For example, pulp, chemical pulp, rayon, acetate, natural cotton, and synthetic fibers can be used alone or in mixtures as the sub-absorbent layer 12. In this embodiment, fibers mainly composed of pulp fibers, rayon fibers, and polyethylene terephthalate (PET) are used.

[0076] The absorbent layer 13 is located on the non-skin side compared to the secondary absorbent layer 12, and on the skin side compared to the back layer 14. It is an absorbent layer that absorbs bodily fluids such as excrement. The absorbent layer 13 is roughly elliptical and located in the approximate center of the pad 1 (more precisely, towards the back). Details about the absorbent layer 13 will be explained later.

[0077] The back layer 14 is a sheet component located on the non-skin side relative to the absorbent layer 13. The back layer 14 has the shape of the pad 1 and, when viewed from above, has approximately the same shape and size as the surface layer 11. The back layer 14 can be a sheet component such as a liquid-permeable sheet or a liquid-impermeable sheet, for example, a sheet film made of synthetic resin, a breathable film, pulp, paper, nonwoven fabric, a breathable liquid barrier sheet, or a sheet component obtained by combining these. In this embodiment, a sheet component obtained by mixing rayon, polyethylene terephthalate (PET), and pulp is used.

[0078] The finger insertion piece 15 is a piece member used to form the finger insertion portion 20. The finger insertion portion 20 is the space between the finger insertion piece 15 and the backing layer 14, which is the space for the wearer to insert their fingers when wearing the pad 1. The length of the finger insertion piece 15 in the front-back direction is shorter than that of the backing layer 14, and the length in the width direction is also shorter than that of the backing layer 14. In addition, it is located on the rear side in the front-back direction, closer to the non-skin side than the backing layer 14. The two sides of the finger insertion piece 15 in the width direction are joined and fixed to the non-skin side of the backing layer 14 by means of a finger insertion piece joint 16 formed by an adhesive such as a hot melt adhesive (see reference). Figure 2 The finger insertion piece 15 has openings at its front and rear ends, respectively, where the finger insertion piece 15 and the back layer 14 are not fixed with adhesive. The front opening is larger than the rear opening. The wearer inserts a finger (e.g., the middle finger) through the front opening of the finger insertion part 20, allowing the pad 1 to be placed against the labia in a supported position.

[0079] As the finger insertion sheet 15, the same material as the surface layer 11 or the back layer 14 can be used. For example, nonwoven fabrics made from composite synthetic fibers such as PE / PP, PE / PET, and PP / PP, such as spunlace nonwoven fabrics, shrinkable nonwoven fabrics, and stretchable spunbond fabrics, can be used; sheet components made from fibers such as rayon, acetate, cotton, pulp, or synthetic resins (e.g., polyethylene terephthalate: PET); breathable films, paper, and breathable liquid barrier sheets can also be used. Additionally, sheets with stretchability such as films made from synthetic rubber and amorphous olefin resins, open-cell foam films, mesh materials, woven fabrics, or fabrics woven with synthetic rubber filaments, spunbond nonwoven fabrics or meltblown nonwoven fabrics primarily made of synthetic rubber, and foam sheets can also be used. In this embodiment, a sheet component mainly composed of pulp and rayon is used.

[0080] Furthermore, while the pad 1 in this embodiment is bent towards the non-skin side via fold F in its unused state, it is not limited to this. For example, it may be unbent without fold F in its unused state, and worn by the wearer who folds it towards the non-skin side. Additionally, it may have multiple fold F. The fold F may have a crease after bending or may not have a crease.

[0081] <Regarding wearing pad 1>

[0082] The pad 1 is worn by folding its central portion in the width direction towards the non-skin side, thus bringing it into contact with the wearer's skin (excretory opening). In this embodiment, the pad 1 is a menstrual product. It is folded towards the non-skin side along the fold line F, and its central portion in the width direction is inserted between the woman's labia to form a worn state. Because the pad 1 has a higher degree of contact with the body (excretory opening) compared to sanitary napkins, leakage of excrement (menstrual blood) is less likely to occur, and discomfort during excretion is less likely to occur.

[0083] When worn, the wearer inserts their fingers (index or middle finger) into the finger insertion part 20 from the front of the pad 1, which is bent at the bend F, and then presses the pad 1 against the labia from the ventral side, thus forming the wearing state. After use, the worn pad 1 can be detached from the toilet bowl or held in hand and thrown into the toilet for flushing. For flushing, the components of the pad 1 and the adhesive are preferably made of biodegradable, water-dispersible, or water-soluble materials. Flushing the pad 1 eliminates the hassle of treating it as trash or reduces the amount of trash.

[0084] Additionally, "biodegradability" refers to the following property: in the presence of actinomycetes and other bacteria, and according to natural processes, under anaerobic or aerobic conditions, a substance decomposes into gases such as carbon dioxide or methane, water, and biomass. The biodegradability (biodegradation rate, biodegradation degree, etc.) of this substance is equivalent to naturally occurring materials such as fallen leaves, or synthetic polymers that are generally recognized as biodegradable under the same environment. "Water dispersibility," also known as hydrolysis, refers to the following property: although a limited amount of moisture (menstrual blood) during wear does not have an impact, fibers easily disperse into small fragments in large amounts of water or flowing water, to a degree that is at least not enough to clog typical toilet pipes. "Water solubility" refers to the following property: although a limited amount of moisture (menstrual blood) during wear does not have an impact, it is soluble in large amounts of water or flowing water.

[0085] <About Absorption Layer 13>

[0086] Figure 5 This is a top view illustrating the structure of the absorbent layer 13. In this embodiment, the absorbent layer 13, starting from the skin side in the thickness direction, sequentially comprises a skin-side sheet 131, an absorbent core 132, and a non-skin-side sheet 133. Furthermore, as... Figure 5 As shown, the area in the center when the pad 1 is divided into three equal parts along the width direction is designated as the central area CR, and the areas on both sides are designated as the end areas SR.

[0087] The absorbent core 132 is a portion that absorbs and retains liquids (body fluids) such as menstrual blood, possessing both absorbency and water retention properties. For example, it can be made from pulp, chemical pulp, rayon, acetate, natural cotton, synthetic fibers, cellulose foam, or a continuous foam of synthetic resin, either alone or in combination. Furthermore, it can be a mixture of granular and fibrous absorbent polymers, or a sheet-like absorbent polymer. Moreover, to maintain the volume of the absorbent core and improve water retention, chemical pulp, acetate, and synthetic fibers that are cross-linked and shredded using a cross-linking agent can be mixed. In the pad 1, pulp fibers (absorbent fibers) shaped into a predetermined form are used.

[0088] The skin-side sheet 131 is a component that covers the absorbent core 132 from the skin side, and the non-skin-side sheet 133 is a component that covers the absorbent core 132 from the non-skin side. Examples of materials that can be used for the skin-side sheet 131 and the non-skin-side sheet 133 include pulverized pulp, cellulose such as cotton, rayon, regenerated cellulose such as microfiber rayon, semi-synthetic cellulose such as acetate and triacetate, and materials obtained by hydrophilicating thermoplastic hydrophobic chemical fibers. In this embodiment, the skin-side sheet 131 of the pad 1 is a sheet made of spunlace material composed of pulp and rayon, and the non-skin-side sheet 133 is a sheet made of pulp such as 100% wet-processed paper.

[0089] Furthermore, by providing skin-friendly side panels 131, excrement that has reached the absorbent layer 13 can easily spread horizontally, and the horizontally dispersed excrement can be absorbed by the absorbent core 132. As a result, the absorbent core 132 can quickly absorb the excrement, thereby easily reducing discomfort to the wearer's skin.

[0090] In addition, the absorption layer 13 is provided with a plurality of slits 18, 18... and a plurality of compression sections 19, 19... Figure 5 (Not shown in the figure). The slit 18 is a cut that penetrates at least the absorbent layer 13 (skin side sheet 131, absorbent core 132, and non-skin side sheet 133) in the thickness direction. However, the slit 18 may also penetrate both the absorbent layer 13 and the sub-absorbent layer 12 in the thickness direction. By providing this slit 18, when wearing the pad 1, the absorbent layer 13 or the sub-absorbent layer 12 can easily deform flexibly following the wearer's body movements, thus improving the fit. In addition, by allowing the absorbed excrement to diffuse along the slit 18 in the front-back and left-right directions, the excrement can be absorbed and retained over a large area of ​​the absorbent core 132. Furthermore, as will be described in detail later, the slit 18 is formed by making a cut from the non-skin side of the absorbent layer 13 in the thickness direction using a cutter or the like. Therefore, in the pad 1 of this embodiment, a slit (cut) is formed at least in the non-skin side sheet 133.

[0091] The slit 18 has a first slit 18a along the width direction and a second slit 18b along the front-back direction. Here, "slit along the width direction" refers to a slit whose smaller angle among the angles formed by the slit (or its tangent) and the width direction is 45 degrees or less. That is, the first slit 18a includes a slit arranged parallel to the width direction and a slit arranged at a predetermined angle of 45 degrees or less relative to the width direction. Similarly, "slit along the front-back direction" refers to a slit whose smaller angle among the angles formed by the slit (or its tangent) and the front-back direction is less than 45 degrees. That is, the second slit 18b includes a slit arranged parallel to the front-back direction and a slit arranged at a predetermined angle of less than 45 degrees relative to the front-back direction.

[0092] Compression section 19 is a portion in which the absorbent layer 13 (skin side sheet 131, absorbent core 132, and non-skin side sheet 133) and the sub-absorbent layer 12 are compressed in the thickness direction. For example, it is formed by overlapping the absorbent layer 13 and the sub-absorbent layer 12 in the thickness direction and performing an embossing process (see reference). Figure 4 By providing the compression section 19, the multiple fibers constituting the absorbent layer 13 and the sub-absorbent layer 12 are pressed together, making it easy for the absorbent layer 13 and the sub-absorbent layer 12 to maintain their shape and preventing them from spreading out. Therefore, when wearing the pad 1, the absorbent layer 13 can be prevented from becoming misshapen or twisted, losing its fit, or leaking excrement when the wearer moves their body.

[0093] Furthermore, the absorbent layer 13 and the sub-absorbent layer 12 are only pressed together by the compression section 19, without the use of adhesives or the like for fixation. Therefore, when the used pad 1 is flushed into the toilet, if the compression section 19 becomes wet, the compression bonds (hydrogen bonds) between the fibers break, and the fibers constituting the absorbent layer 13 and the sub-absorbent layer 12 easily disperse. As a result, hydrolysis (water dispersibility) is improved, making it less likely for problems such as toilet pipe blockage to occur.

[0094] Furthermore, in the absorbent core 132 of this embodiment, the pulp fiber (absorbent fiber) includes absorbent fiber formed from broadleaf trees, namely broadleaf absorbent fiber (broadleaf pulp). This broadleaf absorbent fiber has the characteristics of shorter fiber length and finer fiber diameter compared to the absorbent fiber formed from coniferous trees (coniferous pulp).

[0095] Figure 6 This is a graph showing the distribution of fiber length in hardwood absorbent fibers (hardwood pulp) and softwood absorbent fibers (softwood pulp). The horizontal axis represents fiber length (mm), and the vertical axis represents frequency (%). Figure 6As shown, the average fiber length of coniferous pulp is about 2.5 mm, and the fiber length distribution is wide (including fibers longer than 3 mm, with a standard deviation of 1.6). In contrast, the average fiber length of absorbent hardwood fibers is about 0.79 mm, and the fiber length distribution is narrow (standard deviation of 0.27).

[0096] Furthermore, the average fiber length of pulp fibers refers to the length-weighted average fiber length L(l) measured based on the centerline fiber length (Cont). The length-weighted average fiber length can be measured as the L(l) value using the Kajaani FiberLab fiber properties (off-line) manufactured by Metso Automation. This method is also recommended by JIS P 8226-2 (the standard for fiber length determination based on the non-polarized light method of automated pulp-optical analysis).

[0097] The absorbent core 132 is composed of short-fiber absorbent fibers (average fiber length of approximately 0.8 mm), such as those from hardwood pulp, and thus possesses high water retention. For example, when comparing absorbents made from short-fiber hardwood pulp and those made from long-fiber softwood pulp by the same weight, the fiber number density of hardwood pulp is greater than that of softwood pulp. In other words, by using hardwood pulp, the absorbent core 132 can be made more dense than when using softwood pulp. Furthermore, by increasing the density of the absorbent core 132, the capillary effect can be improved, thus enhancing water retention. Additionally, the fiber number density, which is equivalent to the average number of fibers per unit area, is a value obtained by estimating the number of fibers per unit area in the case of the densest filling structure using fiber thickness plus average inter-fiber distance.

[0098] <Manufacturing Method of Interlabial Pad 1>

[0099] Next, the manufacturing method of the interlabial pad 1 will be explained. Figure 7 This is a flowchart illustrating the manufacturing process of the pad 1 involved in this embodiment. Figure 8 This is a schematic diagram illustrating the manufacturing apparatus 500 for producing absorbent articles such as pad 1. Additionally, Figure 7 as well as Figure 8 This diagram illustrates representative processes involved in the manufacture of pad 1, but does not represent all manufacturing processes.

[0100] Figure 8 The manufacturing apparatus 500 shown can be implemented sequentially. Figure 7Each process shown (S101~S110) intermittently manufactures the pad 1 or other absorbent articles involved in this embodiment. The manufacturing apparatus 500 includes a conveying mechanism 510, an absorbent core lamination mechanism 520, a secondary absorbent layer lamination mechanism 530, a flipping mechanism 540, a first slit forming mechanism 550, a second slit forming mechanism 560, a cutting and sealing mechanism 570, a sailor uniform shaping mechanism 580, a finger insert mounting mechanism 590, and a kneading mechanism 595.

[0101] In the manufacturing process of pad 1, the first step is a transport process: the continuous body of the non-skin side sheet 133 constituting the absorbent layer 13 is transported in the transport direction (S101). Furthermore, in the manufacturing apparatus 500, the transport direction is along the front-to-back direction of pad 1. Hereinafter, the transport direction will also be referred to as the "MD direction (Machine Direction)," and the direction orthogonal to the transport direction (the direction along the width direction of pad 1) will be used. Figure 8 The direction of depth on the paper (the center) is also called the "CD direction (Cross Direction)".

[0102] In the transport process, after the non-skin side sheet continuous body 133a (substrate sheet) connected along the MD direction is released from the raw material roll, it is transported from the upstream side to the downstream side in the MD direction by a transport mechanism 510 composed of transport rollers or the like at a predetermined transport speed. Furthermore, during the transport of the non-skin side sheet continuous body 133a, the pad 1 is manufactured by performing each of the steps S102 to S110.

[0103] Next, the absorbent core lamination process is performed: Absorbent core 132 is laminated relative to the non-skin side sheet continuous 133a (substrate sheet) being transported in the MD direction using the absorbent core lamination mechanism 520 (S102). The absorbent core lamination mechanism 520 includes a defiberizing device 521, a material supply unit 522, and a rotating drum 523. In the absorbent core lamination process, firstly, pulverized pulp, the raw material for the absorbent core 132, is manufactured. The pulverized pulp is manufactured by pulverizing the pulp sheet PS1, which is the raw material, using the defiberizing device 521. The defiberizing device 521 includes a rotating body (e.g., a saw cylinder 521m) with multiple blades on the outer circumferential surface of a cylindrical roller. By rotating this rotating body (saw cylinder 521m) to cut the pulp sheet PS1 unwound from the raw material, the pulp sheet PS1 is finely pulverized to produce pulverized pulp. Alternatively, a rotating body different from the saw barrel 521m can be used to crush the pulp sheet PS1, or a hammer mill can be used instead of a rotating body to crush the pulp sheet PS1 by striking it. In addition, in this embodiment, the pulp sheet PS1, which serves as the raw material for the absorbent core 132, is mainly composed of pulp containing broadleaf pulp as described above, but it may also contain softwood pulp, or it may be a pulp-mixed hydroentangled product.

[0104] The pulverized pulp produced by the defiberization device 521 is collected inside the material supply unit 522 and supplied to the rotary drum 523. The material supply unit 522 is configured to cover the upper part of the rotary drum 523, mixes thermoplastic resin in the pulverized pulp, and further mixes superabsorbent polymer particles (SAP) as needed, and supplies these mixtures to the rotary drum 523 by air transport.

[0105] The rotating drum 523 is a hollow cylindrical drum equipped with a suction mechanism (not shown) that draws air inward from the outer side of its outer circumference. Furthermore, on its outer circumference, a plurality of recesses 523r, serving as a mold for filling the absorbent core 132, are formed at predetermined intervals. When the rotating drum 523 rotates and the recesses 523r enter the material supply section 522, the material (pulp) of the absorbent core 132 supplied from the material supply section 522 is drawn into the recesses 523r by the suction mechanism. When the rotating drum 523 rotates and the recesses 523r containing the material of the absorbent core 132 reach the bottom of the drum, the material of the absorbent core 132 falls out of the recesses 523r and is transferred to the transported substrate sheet (non-skin side sheet continuous 133a) for delivery to the next process. Thus, the absorbent core 132 is deposited on the skin side of the non-skin side sheet 133.

[0106] Next, as the substrate sheet with the absorbent core 132 is transported from the absorbent core lamination mechanism 520 to the downstream side in the transport direction (MD direction), the continuum 131a of the overlapping skin side sheet 131 (see reference) Figure 8 The skin side sheet 131 is then deposited in the sub-absorption layer lamination mechanism 530 to form the absorption layer 13. Additionally, for simplicity, the skin side sheet 131... Figure 8 The following processes are not illustrated.

[0107] Next, a sub-absorbent layer lamination process is performed: the sub-absorbent layer 12 is laminated on the skin side in the thickness direction of the absorbent layer 13 using the sub-absorbent layer lamination mechanism 530 (S103). The sub-absorbent layer lamination mechanism 530 includes a defibering device 531. The defibering device 531 includes a rotating body, i.e., a saw cylinder 531m, which has multiple blades on the circumferential surface of a cylindrical roller. And, similarly to the defibering device 521, the pulp sheet PS2, which is unwound from the raw material roll, is pulverized by cutting and rotating it to produce pulverized pulp, which is the raw material for the sub-absorbent layer 12. The pulverized pulp is directly spread on the substrate sheet, and the layer of pulverized pulp (sub-absorbent layer 12) is laminated on the skin side of the absorbent layer 13.

[0108] The pulp sheet PS2 used in the sub-absorbent layer lamination process is composed of softwood pulp, and may also contain hardwood pulp, and may also be mixed with rayon. Furthermore, the hardwood pulp content in pulp sheet PS2 is lower than that in pulp sheet PS1. Therefore, compared to the absorbent core 132, the sub-absorbent layer 12 has a longer average fiber length and a larger average fiber diameter.

[0109] Furthermore, after the sub-absorbent layer 12 is deposited on the absorbent layer 13, an embossing process is performed to form the compression section 19. As a result, the multiple fibers constituting the absorbent layer 13 and the sub-absorbent layer 12 are pressed together with each other, and they do not easily peel off or deform while the two are deposited.

[0110] Next, a flipping process is performed: the substrate sheet (absorbing layer 13 and sub-absorbing layer 12) is flipped in the thickness direction by the flipping mechanism 540 (S104). Figure 8 In the process, the substrate sheet, which is transported from left to right on the paper, is flipped from right to left in the transport direction, and its thickness direction is also flipped. Therefore, after the flipping process, it is transported in the MD direction with the absorption layer 13 deposited on the vertical side of the sub-absorption layer 12.

[0111] Next, the first slit forming process is performed: using the first slit forming mechanism 550, the first slit 18a is formed in the absorption layer 13 (S105). The first slit forming mechanism 550 has a cutting roller 551 and an anvil roller 552. The cutting roller 551 has multiple cutting edges on the circumferential surface of a cylindrical roller and is a rotating body driven to rotate around a rotation axis along the CD direction. The anvil roller 552 is located in the thickness direction ( Figure 8It is arranged facing the cutting roller 551 in the vertical direction (of the CD direction) and is a rotating body driven to rotate around a rotation axis along the CD direction. In this embodiment, as Figure 8 As shown, a cutting roller 551 is provided on the upper side (the non-skin side of the pad 1) of the manufacturing apparatus 500 in the vertical direction, and an anvil roller 552 is provided on the lower side (the skin side of the pad 1). Furthermore, the substrate sheet (absorbent layer 13 and sub-absorbent layer 12) is clamped and pressed in the thickness direction by the cutting roller 551 and the anvil roller 552 to form the first slit 18a. The specific configuration and function of the cutting roller 551 and the anvil roller 552 will be explained later.

[0112] Next, the second slit forming process is performed: using the second slit forming mechanism 560, a second slit 18b is formed in the absorption layer 13 (S106). The second slit forming mechanism 560 has a cutting roller 561 and an anvil roller 562. The cutting roller 561 has multiple cutting edges on the circumferential surface of a cylindrical roller and is a rotating body driven to rotate around a rotation axis along the CD direction. The anvil roller 562 is located in the thickness direction ( Figure 8 The cutting roller 561 is arranged facing the cutting roller 561 in the vertical direction (in the middle), and is a rotating body driven to rotate around a rotation axis along the CD direction. The specific structure and function of the cutting roller 561 and the anvil roller 562 will be explained later. Furthermore, in the second slit forming process, the second slit forming mechanism 560 cuts the substrate sheet (absorbent layer 13 and sub-absorbent layer 12) into... Figure 1 It has a roughly elliptical shape, as shown by the dashed line.

[0113] After the slit 18 is formed in the absorber layer 13 (and the sub-absorber layer 12) through the first slit forming process (S105) and the second slit forming process (S106), in the thickness direction, a continuous 11a of the surface layer 11 is laminated from the skin side of the sub-absorber layer 12, and a continuous 14a of the back layer 14 is laminated from the non-skin side of the absorber layer 13.

[0114] Next, a cutting and sealing process is performed: using the cutting and sealing mechanism 570, the continuous body 11a of the surface layer 11 and the continuous body 14a of the back layer 14, in which the absorber layer 13 and the sub-absorber layer 12 are sandwiched in the thickness direction, are cut into a predetermined shape, and the two are joined (sealed) (S107). In the cutting and sealing process, in the region outside of the sub-absorber layer 12 (absorber layer 13), the continuous body 11a of the surface layer 11 and the continuous body 14a of the back layer 14 are joined using a known welding mechanism such as hot melt or ultrasonic welding, or an adhesive such as hot melt adhesive. That is, in Figure 1In the planar state of the pad 1 shown, the area outside the portion surrounded by the dashed line representing the sub-absorbent layer 12 seals the surface layer 11 and the back layer 14 together. Furthermore, the strip-shaped continuous bodies 11a and 14a extending in the MD direction are cut along the outer edge (outline) of the pad 1, and each pad 1 is cut off.

[0115] Next, the sailor suit shaping process is performed: using the sailor suit shaping mechanism 580, each pad 1 is bent at its center in the width direction (CD direction) along the front-to-back direction (MD direction) (S108). The sailor suit shaping mechanism 580 is as follows... Figure 3B As shown, the pad 1 is bent into a triangle that bulges toward the skin along the fold line F in the front-back direction (MD direction).

[0116] Next, the finger insert installation process is performed: using the finger insert installation mechanism 590, the insert 15 is installed on the non-skin side of the back layer 14 (S109). The insert installation mechanism 590 is as follows... Figure 3B As shown, the insert 15 is installed on the non-skin side of the back layer 14 of the pad 1, which is bent into a triangle.

[0117] Next, a loosening process is performed: the loosening mechanism 595 loosens the pad 1 (absorbent article) (S110). The loosening mechanism 595 has multiple rollers that transport the pad 1, which is folded at the fold line F, along its circumference. The pad 1 is bent along the circumference of the rollers in one side of the thickness direction and the other side, thereby loosening and homogenizing the uneven distribution or interlacing of the pulp fibers contained in the pad 1. As a result, the absorbent layer 13 can be easily deformed flexibly, improving the fit of the pad 1 when worn. In addition, since the unevenness of the pulp fibers is corrected, the absorbency and liquid diffusion are improved.

[0118] After the kneading process, pad 1 is individually packaged on the downstream side of the MD direction and shipped to the market as individual or multiple interlabial pad packages.

[0119] <On the formation of slit 18>

[0120] Next, the details of the methods for forming the first slit 18a and the second slit 18b will be explained. First, the method for forming the first slit 18a in the first slit forming step (S105) will be explained. Figures 9A-9C This is a diagram illustrating the configuration of the cutting roller 551 used in forming the first slit 18a. Figure 9A This is a top view of the cutting roller 551 viewed from the MD direction. Figure 9B It is a diagram showing the configuration pattern of a plurality of blades 551c provided on the circumferential surface 551f of the cutting roller 551. Figure 9C It is shown Figure 9BA cross-sectional view taken from the D-D direction. Additionally, Figures 10A-10B This is a diagram illustrating the configuration of the anvil roller 552 used in forming the first slit 18a. Figure 10A This is a top view of the anvil roller 552 viewed from the MD direction. Figure 10B It is an enlarged representation Figure 10A The graph of region E.

[0121] like Figure 9A As shown, the cutting roller 551 of the first slit forming mechanism 550 is a cylindrical rotating body that rotates around a rotation axis Ar1 along the CD direction, and has multiple cutting edges 551c, 551c... protruding outward in the radial direction from the circumferential surface 551f of the cylinder. The multiple cutting edges 551c are arranged according to... Figure 9B Configured according to the pattern shown, Figure 9B Patterns such as Figure 9A The cutting rollers 551 are arranged intermittently along the circumferential direction at predetermined intervals on their peripheral surface 551f. Multiple blades 551c are each configured to form slits primarily along the CD direction (the width direction of the pad 1). That is, each blade 551c of the cutting roller 551 is arranged primarily parallel to the CD direction or inclined at a predetermined angle of less than 45 degrees relative to the CD direction. With such blades 551c, multiple first slits 18a can be formed on the pad 1. However, it is also possible to form a portion of the slits 18 along the MD direction using the cutting roller 551.

[0122] The anvil roller 552 of the first slit forming mechanism 550 is a cylindrical rotating body that rotates around the rotation axis Ar2 along the CD direction, and is arranged facing the cutting roller 551 with the pad 1 (substrate sheet) in between (see reference). Figure 8 Furthermore, while the anvil roller 552 and the cutting roller 551 are rotating, a slit (cut) corresponding to the shape of the blade 551c is formed on the substrate sheet (in this embodiment, the absorption layer 13, the sub-absorption layer 12, etc.) sandwiched between the two at the part where the circumferential surface 552f of the anvil roller 552 abuts the end of the blade 551c of the cutting roller 551.

[0123] Furthermore, a groove 552d recessed inward toward the radial direction is provided on a portion of the circumferential surface 552f of the anvil roller 552. In this embodiment, a pair of grooves 552d are provided on both sides of the central position CDL of the anvil roller 552 in the CD direction. In addition, the grooves 552d are continuously provided along the circumferential direction of the anvil roller 552 (the direction corresponding to the MD direction).

[0124] Figure 11 This diagram illustrates the operation of forming the first slit 18a by the cutting roller 551 and the anvil roller 552. Figure 11The diagram shows the positional relationship between the cutting edge 551c of the cutting roller 551 and the groove 552d of the anvil roller 552 when the cutting roller 551 and the anvil roller 552 are aligned at their central positions CDL in the CD direction and facing each other.

[0125] like Figure 11 As shown, in the CD direction, on both sides of the central position CDCL, there are portions where the cutting edge 551c overlaps with the groove 552d. For example, in Figure 11 In region F, the first portion np of the cutting edge 551c of the cutting roller 551, located at the center in the CD direction, overlaps with the groove 552d of the anvil roller 552. On the other hand, the second portion cp of the cutting edge 551c, located at both ends in the CD direction, does not overlap with the groove 552d. That is, when the end of the cutting edge 551c of the cutting roller 551 abuts against the circumferential surface 552f of the anvil roller 552, the second portion cp of the cutting edge 551c abuts against the circumferential surface 552f, but the first portion np does not abut against the circumferential surface 552f.

[0126] In this case, the second portion cp at both ends of the blade 551c in the CD direction forms a slit 18 by pressing the substrate sheet (absorbent layer 13, etc.) against the circumferential surface 552f of the anvil roller 552. On the other hand, the first portion np at the center of the blade 551c in the CD direction presses the substrate sheet (absorbent layer 13, etc.) against the groove 552d of the anvil roller 552, so the slit 18 is not formed. Thus, a slit 18 is formed in which the center of the first slit 18a in the CD direction (width direction) is cut off (see reference). Figure 5 The end region SR).

[0127] Figure 12A as well as Figure 12B This diagram illustrates the case where no groove is provided on the circumference of the anvil roller when forming a slit using a cutting roller and anvil roller. Figure 13A as well as Figure 13B This diagram illustrates the case where a groove is provided on the circumferential surface of the anvil roller when a slit is formed using a cutting roller and anvil roller.

[0128] In cases where a slit is formed on a substrate using a cutting roller and an anvil roller, the circumferential surface of the anvil roller is typically a uniform surface and does not have a groove similar to the groove 552d of the anvil roller 552 in this embodiment. Therefore, as Figure 12A In this configuration, the entire tip of the cutting roller's blade presses against the circumferential surface of the anvil roller, cutting the substrate at the pressed portion. That is, by pressing the entire tip of the cutting roller's blade against the circumferential surface of the anvil roller, a slit of the same length as the width of the blade is formed. Furthermore, as the cutting roller and anvil roller rotate, the tip of the cutting roller's blade separates from the circumferential surface of the anvil roller, as... Figure 12BIn this case, the substrate, pressed by the blade, may become stuck to the blade and difficult to detach, a phenomenon known as "blade retention." If such blade retention occurs, it becomes difficult to stably transport the substrate along the MD direction, potentially causing malfunctions during the cutting action performed by the cutting roller, resulting in decreased manufacturing efficiency.

[0129] In contrast, in this embodiment, a groove 552d is provided on the circumferential surface 552f of the anvil roller 552. Furthermore, as... Figure 13A In this way, the second portion cp of the cutting edge 551c of the cutting roller 551 presses against the substrate (absorbent core 132, non-skin side sheet 133) towards the circumferential surface 552f of the anvil roller 552, forming a slit 18. On the other hand, the first portion np of the cutting edge 551c of the cutting roller 551 does not form a slit 18 because it presses against the groove 552d of the anvil roller 552. If, in this state, the cutting roller 551 and the anvil roller 552 rotate, and the end of the cutting edge 551c of the cutting roller 551 separates from the circumferential surface 552f of the anvil roller 552, then as Figure 13B In that way, at least in the first part of the blade 551c, there is no substrate attached.

[0130] This is because, since no slit 18 is formed in the portion (first part np) where the blade 551c of the cutting roller 551 overlaps with the groove 552d of the anvil roller 552, the blade 551c cannot be pressed forcefully against the substrate (absorbent core 132, non-skin side sheet 133). Therefore, even if the substrate is attached to a part of the blade 551c (second part cp), there is no substrate attached to the other part of the blade 551c (first part np), making it easy to form a base point that allows the substrate to detach from the blade 551c. As a result, blade retention is unlikely to occur.

[0131] Additionally, in Figure 13, in the CD direction, the entire groove 552d overlaps with the cutting edge 551c, but it is also possible that a part of the groove 552d overlaps with the cutting edge 551c. Figure 14 This is a diagram showing a modified example of Figure 13. In this... Figure 14 In the CD direction (the width direction of the blade 551c), the first portion np′ of the end located on the other side of the blade 551c overlaps with the groove 552d, while the second portion cp′ of the end located on one side does not overlap with the groove 552d. In this case, in the second portion cp′, the blade 551c presses the substrate against the circumferential surface 552f of the anvil roller 552 to form a slit 18. On the other hand, in the first portion np′, since the blade 551c presses the substrate against the groove 552d of the anvil roller 552, no slit 18 is formed. Therefore, in the first portion np′, the substrate does not adhere to the blade 551c, forming a base point for the substrate to detach from the blade 551c, thereby making it difficult for the blade to remain stuck.

[0132] Furthermore, when the slit 18 is formed in this embodiment, the blade 551c of the cutting roller 551 presses the substrate from the non-skin side in the thickness direction toward the circumferential surface 552f of the anvil roller 552. That is, the cut is made from the non-skin side sheet 133 side disposed on the non-skin side of the substrate (absorbent layer 13 and sub-absorbent layer 12). Since the non-skin side sheet 133 has higher rigidity and more stable shape than the absorbent core 132 or the sub-absorbent layer 12 where pulp fibers are interwoven, it is easy to cut the fibers when the cut is formed, and the blade 551c is easy to detach from the substrate after the cut is formed. That is, blade retention is unlikely to occur. Therefore, compared with the case where the press is made from the skin side (the side of the sub-absorbent layer 12) with lower rigidity, blade retention is less likely to occur.

[0133] Furthermore, the substrate to which the slit 18 is formed has a structure in which an absorbent layer 13 and a sub-absorbent layer 12 are laminated. As described above, the absorbent layer 13 is mainly composed of broadleaf pulp fibers with short fiber length and small diameter, and therefore, the fibers are easily made dense. On the other hand, the sub-absorbent layer 12 is composed of coniferous pulp fibers with long fiber length and large diameter, and therefore, the fibers are less likely to be made dense compared to the absorbent layer 13. Therefore, the absorbent layer 13 has higher rigidity than the sub-absorbent layer 12. In the embodiment, the substrate is pressed by a blade 551c from the side of the absorbent layer 13 (the non-skin side of the substrate) where the rigidity is high. That is, a cut is formed from the side with higher rigidity in the thickness direction of the substrate. Therefore, compared to the opposite case, the shape of the substrate (absorbent layer 13 and sub-absorbent layer 12) is easily maintained when pressed by the blade 551c, and the slit 18 can be formed neatly.

[0134] Furthermore, preferably, one of the plurality of blades 551c, 551c... of the cutting roller 551, which is located at a position facing (overlapping) with the groove 552d of the anvil roller 552, is as follows: Figure 11 or Figure 13A As shown, it is configured to traverse the entire groove 552d in the CD direction. In other words, in the CD direction (corresponding to the width direction of the cutting edge 551c), the end of one side of the cutting edge 551c is located at the same position as the end of one side of the groove 552d, or at a position one side closer to the end of one side of the groove 552d, and the end of the other side of the cutting edge 551c is located at the same position as the end of the other side of the groove 552d, or at a position one side closer to the end of the other side of the groove 552d.

[0135] With this configuration, a short slit 18 can be formed at the second portion cp at the end of a blade 551c in the CD direction (width direction), as shown in FIG. 13. Conventionally, to form a short slit, a short blade needs to be provided on the cutting roller according to the desired slit width. However, such a short blade is prone to wear, resulting in maintenance difficulties and increased costs. Furthermore, due to blade retention and other factors, it is difficult to form a neat slit (it is difficult to accurately create a cut relative to the substrate). In contrast, according to this embodiment, a short slit 18 adjacent to at least one side of the groove 552d in the width direction can be easily formed at the second portion cp at the end of the blade 551c in the width direction. Furthermore, since the slit 18 is not formed at the first portion np at the center of the blade 551c in the width direction, blade retention is less likely to occur, and a neat short slit 18 can be formed.

[0136] Furthermore, preferably, in the anvil roller 552, the boundary between the circumferential surface 552f and the groove 552d is chamfered. Figure 10B In this design, at the boundary between the circumferential surface 552f of the anvil roller 552 and the groove 552d, the corner portion ch, indicated by black, is chamfered. By providing such a chamfered portion ch, the boundary between the portion of the cutting edge 551c of the cutting roller 551 that overlaps with the circumferential surface 552f of the anvil roller 552 in the CD direction (forming the second portion cp of the slit 18) and the portion that overlaps with the groove 552d (not forming the first portion np of the slit 18) is gently altered by the force applied when the cutting edge 551c is pressed. Therefore, compared to the case without the chamfered portion ch, the substrate is less likely to adhere to the cutting edge 551c at the end of the slit 18, making it easier to suppress cutting edge retention. Furthermore, the chamfer at the boundary between the circumferential surface 552f and the groove 552d can be used as... Figure 10B It can be formed as a straight line or a curve. That is, the boundary between the circumferential surface 552f and the groove 552d can also be a curved surface.

[0137] Next, the method for forming the second slit 18b in the second slit forming process (S106) will be described. Figures 15A-15C This diagram illustrates the configuration of the cutting roller 561 used in forming the second slit 18b. Figure 15A This is a top view of the cutting roller 561 viewed from the MD direction. Figure 15B It is a diagram showing the configuration pattern of a plurality of blades 561c provided on the circumferential surface 561f of the cutting roller 561. Figure 15C It is shown Figure 15B A cross-sectional view taken from the G-G direction.

[0138] like Figure 15AAs shown, the cutting roller 561 of the second slit forming mechanism 560 is a cylindrical rotating body that rotates around a rotation axis Ar3 along the CD direction, and has multiple cutting edges 561c, 561c... protruding outward in the radial direction from the circumferential surface 561f of the cylinder. The multiple cutting edges 561c... Figure 15B The pattern configuration shown, Figure 15B Patterns such as Figure 15A The cutting roller 561 is arranged intermittently along its circumferential direction at a predetermined interval on its peripheral surface 561f. Multiple blades 561c are respectively configured to form slits primarily along the MD direction (the front-to-back direction of the pad 1). That is, the blades 561c of the cutting roller 561 are arranged primarily parallel to the MD direction or inclined at a predetermined angle of less than 45 degrees relative to the MD direction. Multiple second slits 18b can be formed on the pad 1 using such blades 561c. However, a portion of the slits 18 along the CD direction can also be formed using the cutting roller 561.

[0139] Additionally, on the circumferential surface 561f of the cutting roller 561, a circumferential cutting edge 561rc is provided in such a way that it surrounds a plurality of cutting edges 561c, 561c... along the MD direction. The shape of the circumferential cutting edge 561rc and the outer edge of the sub-absorption layer 12 ( Figure 1 The sheet-like sub-absorbent layer 12, which is laminated in the sub-absorbent layer lamination process (S103), is set in a roughly elliptical shape to match the dotted line. The sub-absorbent layer 12 is shaped into a roughly elliptical shape by cutting it as if it were molded.

[0140] The anvil roller 562 of the second slit forming mechanism 560 is a cylindrical rotating body that rotates around a rotation axis along the CD direction, and is arranged facing the cutting roller 561 with the pad 1 (substrate sheet) in between (see reference). Figure 8 Furthermore, no recess (groove) corresponding to the groove 552d of the anvil roller 552 (see Figure 10) is provided on the circumferential surface of the anvil roller 562. While the anvil roller 562 and the cutting roller 561 rotate, a slit (cut) corresponding to the shape of the blade 561c is formed on the substrate sheet sandwiched between them (in this embodiment, the absorption layer 13, the sub-absorption layer 12, etc.). Simultaneously, at the portion where the circumferential surface of the anvil roller 562 abuts the end of the circumferential blade 561rc of the cutting roller 561, the substrate sheet (absorption layer 13 and sub-absorption layer 12) sandwiched between them is cut into an approximately elliptical shape along the shape of the circumferential blade 561rc.

[0141] Furthermore, a portion of the blade 561c of the cutting roller 561 of the second slit forming mechanism 560 is arranged in the CD direction at a position overlapping with the groove 552d of the anvil roller 552 of the first slit forming mechanism 550 (see reference). Figure 15BTherefore, a portion of the second slit 18b formed by the second slit forming process (S106) is formed on the portion of the first slit 18a not formed by the first slit forming process (S105) (the portion corresponding to the groove 552d of the anvil roller 552). As a result, in the CD direction, at both ends of the CD direction (width direction) where the groove 552d is provided, as... Figure 5 As shown, it does not have the portion where the first slit 18a and the second slit 18b intersect.

[0142] Thus, by utilizing the first slit forming mechanism 550 and the second slit forming mechanism 560, a plurality of first slits 18a along the CD direction (width direction) and a plurality of second slits 18b along the MD direction (front-back direction) are formed in the absorption layer 13 (and the sub-absorption layer 12) (see reference). Figure 5 ).

[0143] In this embodiment, in the second slit formation step (S106), the entire blade 561c of the cutting roller 561 presses the absorbent layer 13 toward the circumferential surface of the anvil roller 562, thereby forming the second slit 18b over the entire area of ​​the blade 561c. On the other hand, in the first slit formation step (S105), the first portion np of the blade 551c of the cutting roller 551 presses the absorbent layer 13 toward the groove 552d of the anvil roller 552, thereby not forming the first slit 18a in the first portion np of the blade 551c (which corresponds to the other portion).

[0144] Because the cutting edge 561c of the cutting roller 561 forming the second slit 18b is arranged along the MD direction, the length of the portion of the cutting edge 561c that abuts against the circumferential surface of the anvil roller 562 at a certain moment is short when the slit is formed, making it difficult for the substrate to adhere and thus preventing blade retention. In contrast, because the cutting edge 551c of the cutting roller 551 forming the first slit 18a is arranged along the CD direction, the length of the portion of the cutting edge 551c that abuts against the circumferential surface 552f of the anvil roller 552 at a certain moment is long when the slit is formed, making it easier for the substrate to adhere to the cutting edge 551c and causing blade retention. Therefore, in the first slit forming process (S105), the first slit 18a is not formed by a portion of the cutting edge 551c (the first portion np), making blade retention difficult to occur. In addition, because blade retention is difficult to occur, the shape of the absorption layer 13 is less likely to become distorted.

[0145] Furthermore, in the first slit forming process (S105), a portion of the plurality of cutting edges 551c, 551c... provided on the circumferential surface 551f of the cutting roller 551 are arranged at an angle of less than 45 degrees relative to the CD direction, forming a first slit 18a inclined relative to the CD direction. Figure 5In the middle, in the regions on both sides when the pad 1 is divided into three equal parts along the width direction, there is a first slit 18a that is inclined relative to the CD direction.

[0146] When the first slit 18a is formed, if the blade 551c is arranged parallel to the CD direction, there is a possibility that the entire blade 551c and the circumferential surface 552f of the anvil roller 552 may come into contact at the same moment. That is, there is a possibility that the length of the portion of the blade 551c that presses against the circumferential surface 552f of the anvil roller 552 may become longer. In this case, the substrate is more likely to adhere to the blade 551c, and blade retention may easily occur.

[0147] On the other hand, when the blade 551c is arranged at an angle relative to the CD direction, only a portion of the blade 551c abuts against the circumferential surface 552f of the anvil roller 552. Therefore, it is possible to prevent the entire blade 551c from abutting against the circumferential surface 552f of the anvil roller 552 at the same time. That is, the length of the portion of the blade 551c that presses against the circumferential surface 552f of the anvil roller 552 at a given moment can be shortened. This makes blade retention less likely.

[0148] Furthermore, when the cutting edge 551c of the cutting roller 551 is arranged at an angle relative to the CD direction, it is preferable that the angles are opposite on the front and rear sides in the front-rear direction. That is, it is preferable that the cutting edge 551c of the cutting roller 551 forms the first slit 18a in such a way that the angles of the first slit 18a relative to the CD direction are opposite on one side and the other side at the central position CL in the front-rear direction of the pad 1.

[0149] exist Figure 5 In this case, the first slit 18a, which is located at the front of the central position CL in the front-back direction, and the first slit 18a, which is located at the rear of the central position CL, have opposite inclination directions. If the first slit 18a is inclined in the same direction on the entire pad 1, the absorbent layer 13 and the like are prone to bending and deforming along the first slit 18a in the same direction, which may make it difficult to reliably match the concavity and convexity of the wearer's crotch when worn. In contrast, if the inclination directions of the first slit 18a are opposite at the front and back of the central position CL, the bending and deformation directions of the absorbent layer 13 and the like at the front and back of the central position CL are also opposite, thus making it easier to match the concavity and convexity of the wearer's crotch.

[0150] Furthermore, on the peripheral surface 551f of the cutting roller 551 used in the first slit forming process (S105), as shown in FIG9, a plurality of cutting edges 551c, 551c... are intermittently provided along the circumferential direction (MD direction). On the other hand, on the peripheral surface 552f of the anvil roller 552 used in the first slit forming process (S105), as shown in FIG9... Figure 10AAs shown, a groove 552d is continuously provided along the circumferential direction (MD direction). Furthermore, while the cutting roller 551 and the anvil roller 552 are rotated in the circumferential direction (MD direction), the cutting edge 551c is pressed against the circumferential surface 552f of the anvil roller 552 and the groove 552d, thereby forming the first slit 18a.

[0151] At this time, since the groove 552d of the anvil roller 552 is continuously arranged along the MD direction, when the blade 551c is pressed towards the groove 552d, it is not necessary for the blade 551c to be phase-aligned with the groove 552d. For example, even if the relative positional relationship in the MD direction of the circumferential surface 551f of the cutting roller 551 and the circumferential surface 552f of the anvil roller 552 changes due to rotational speed deviations in the cutting roller 551 and the anvil roller 552, such as... Figure 11 In this way, the cutting edge 551c can always be pressed against the groove 552d. Therefore, the first slit 18a can be formed with high precision.

[0152] Furthermore, the grooves 552d of the anvil roller 552 are provided on both sides of the central position CDL in the CD direction (width direction). In the portion where the grooves 552d are provided, as illustrated in FIG13, a portion (first portion np) of the blade 551c of the cutting roller 551 presses the substrate (absorbent layer 13, etc.) towards the grooves 552d, thus making it difficult for the substrate to adhere to the blade 551c and preventing blade retention. Moreover, by providing such grooves 552d on both sides in the CD direction (width direction), blade retention on both sides in the width direction of the absorbent layer 13 can be easily suppressed. Therefore, on both sides in the width direction of the absorbent layer 13, the blade 551c after the formation of the first slit 18a can easily detach from the substrate (absorbent layer 13), and the displacement of the absorbent layer 13 from both sides can be suppressed.

[0153] In absorbent articles such as pad 1 manufactured by this method, multiple first slits 18a are formed along the width direction on both sides, and multiple second slits 18b are formed along the front-back direction. Furthermore, none of the multiple slits 18a and 18b intersect on either side of the width direction (see reference). Figure 5 ).

[0154] If the first slit 18a and the second slit 18b intersect, a cross-shaped cut is formed on the rigid non-skin side panel 133 due to the intersecting slits 18a and 18b. Furthermore, when wearing absorbent clothing, if the non-skin side panel 133 rolls up towards the skin at this cut, the rolled-up non-skin side panel 133 will irritate the labia, potentially causing discomfort or a feeling of imbalance for the wearer. In contrast, according to the manufacturing method of this embodiment, a pad 1 can be manufactured in which the first slit 18a and the second slit 18b do not intersect in the width direction on both sides when worn. That is, the first slit 18a and the second slit 18b can be formed at both ends in the width direction without intersecting each other. Therefore, it is difficult for the non-skin side panel 133 to roll up, suppressing any feelings of imbalance or discomfort experienced by the wearer.

[0155] Additionally, since the first slit 18a and the second slit 18b intersect at the central portion in the width direction of the pad 1 (see reference...) Figure 5 Therefore, sometimes the non-skin side 133 curls at the intersection. However, the central part of the width direction of the pad 1 is the part that is sandwiched between the labia (the groove of the vaginal opening) when worn, so even if curling occurs on the skin side, it is difficult for the wearer to feel unbalanced.

[0156] Furthermore, in order to prevent the slits 18a and 18b from intersecting at both sides in the width direction, the slits 18a and 18b are formed in this embodiment as follows: Specifically, in the second slit forming step (S106), the second slit 18b is formed along the MD direction in a manner that overlaps with the portion where the first slit 18a was not formed in the CD direction during the first slit forming step (S105) by pressing a portion (first part np) of the cutting roller 551's blade 551c towards the groove 552d. Thus, non-intersecting slits can be formed with high precision at low cost.

[0157] <Modified example of the first slit forming mechanism 550>

[0158] In the first slit forming mechanism 550, a first slit 18a along the CD direction (width direction of the pad 1) is formed mainly by using a cutting roller 551 having a blade 551c along the CD direction and an anvil roller 552 having a groove 552d along the MD direction. On the other hand, if the cutting roller 551 and anvil roller 552 shown in the following modified example are used, the slit 18a along the MD direction can also be formed.

[0159] Figure 16This figure illustrates a variation of the first slit forming mechanism 550. In this variation, the configurations of the cutting roller 551 and the anvil roller 552 differ from those described in the embodiment. The cutting roller 551 in this variation is a cylindrical rotating body that rotates around a rotation axis Ar1 along the CD direction, and has multiple cutting edges 551c, 551c… on its circumferential surface 551f. However, in this variation, the cutting edges 551c are arranged circumferentially (MD direction). The anvil roller 552 in this variation is a cylindrical rotating body that rotates around a rotation axis Ar2 along the CD direction, as shown in the figure. Figure 16 It is arranged facing the cutting roller 551. Furthermore, a groove 552d along the CD direction is provided on the circumferential surface 552f of the anvil roller 552.

[0160] With the substrate sandwiched between the cutting roller 551 and the anvil roller 552 in the modified example, the roller is rotated to press the cutting edge 551c of the cutting roller 551 against the circumferential surface 552f of the anvil roller 552, thereby forming a slit 18 (cutting slit) on the substrate. Here, since the anvil roller 552 has a groove 552d along the CD direction, the cutting edge 551c of the cutting roller 551 does not form a slit 18 in the portion facing the groove 552d.

[0161] That is, if a portion of one of the blades 551c on the cutting roller 551 presses against the substrate toward the circumferential surface 552f of the anvil roller 552, a slit 18 is formed along the MD direction. On the other hand, if another portion of one of the blades 551c presses against the substrate toward the groove 552d of the anvil roller 552, the slit 18 is not formed. In the portion where the slit 18 is not formed, the substrate is difficult to adhere to the other portion of the blade 551c. Therefore, it is easy to form a base point for the substrate to detach from the blade 551c. Thus, when the slit 18 along the MD direction is formed, blade retention is less likely to occur.

[0162] ===Other Implementation Methods===

[0163] The embodiments of the present invention have been described above. The purpose of these embodiments is to facilitate understanding of the present invention, and not to limit its interpretation. Furthermore, changes or improvements can be made to the present invention without departing from its concept, and the present invention naturally includes equivalent configurations.

[0164] In the above embodiment, the absorbent core 132 of the absorbent layer 13 is described as being composed of short fibers with an average fiber length of about 0.8 mm. Conventionally, when it is desirable to finely pulverize pulp to shorten fiber length, a common practice is to add a softener (de-tapering agent) such as a fourth-grade ammonium surfactant to the pulp flakes before pulverization to facilitate pulp pulverization (so-called pulp treatment). However, if a softener (de-tapering agent) is used, the absorbency may be easily hindered.

[0165] Therefore, the absorbent fibers constituting the absorbent core 132 of the pad 1 are preferably composed without softener (de-adhesive). This helps to suppress the decrease in the water retention performance of the absorbent core 132. In the above embodiment, since the absorbent core 132 is formed using hardwood pulp, even without using softener (de-adhesive), the average fiber length can be set to approximately 0.8 mm, achieving an absorbent core 132 with excellent water absorption and softness.

[0166] In the above embodiment, a pad 1 configured such that the absorbent layer 13 is disposed on the non-skin side compared to the sub-absorbent layer 12 has been described (see reference). Figure 2 (etc.), but their arrangement in the thickness direction can also be reversed. For example, the sub-absorbent layer 12 can be arranged on the non-skin side in the thickness direction of the absorbent layer 13. Alternatively, the pad 1 can be configured without the sub-absorbent layer 12 and only have the absorbent layer 13.

[0167] Explanation of reference numerals in the attached figures

[0168] 1. Interlabial pad (pad, absorbent material).

[0169] 11 Surface layer, 11a Continuum,

[0170] 12 sub-absorption layers,

[0171] 13. Absorption layer

[0172] 131 skin profile, 131a continuum,

[0173] 132 Absorbent Core

[0174] 133 Non-skin side plate, 133a continuum,

[0175] 14 Back side layer, 14a Continuum,

[0176] 15-finger insertion piece, 15-finger insertion piece non-jointing part,

[0177] 16. Insert fingers into the joint of the plate.

[0178] 17. Back layer joint,

[0179] 18. Slits

[0180] 18a First slit, 18b Second slit

[0181] 19. Compression section

[0182] 20 fingers insertion point,

[0183] 500 manufacturing unit,

[0184] 510 Handling equipment,

[0185] 520 Absorbent Core Lamination Mechanism,

[0186] 521 Fiber unwinding device, 522 Material supply unit, 523 Rotating drum, 523r Recess,

[0187] 530 absorber layer stacking mechanism,

[0188] 531 Fiber Debonding Device

[0189] 540 Tilting Mechanism

[0190] 550 First slit forming mechanism,

[0191] 551 cutting roller, 551f circumferential surface, 551c blade.

[0192] 552 anvil roller, 552f circumferential surface, 552d groove.

[0193] 560 Second slit forming mechanism,

[0194] 561 cutting roller, 561f circumferential surface, 561c cutting edge, 561rc circumferential cutting edge.

[0195] 562 Anvil Roller

[0196] 570 Cut-off sealing mechanism,

[0197] 580 Sailor Suit Molding Mechanism

[0198] 590 Finger Insertion Piece Mounting Mechanism

[0199] 595 Kneading and loosening mechanism,

[0200] F is a broken line (bend line).

[0201] PS1 pulp sheets, PS2 pulp sheets

[0202] CR central area

[0203] SR end region.

Claims

1. A method for manufacturing an absorbent article, the method comprising manufacturing an absorbent article having an absorbent core and a non-skin side sheet disposed on a non-skin side in the thickness direction relative to the absorbent core, characterized in that, The above-mentioned method for manufacturing absorbent articles has the following characteristics: The transport process involves transporting the aforementioned non-skin side sheet in the transport direction; A lamination process, wherein the absorbent core is laminated onto the transported non-skin side sheet; and The slit-forming process, which occurs after the lamination process, involves forming a slit at least on the non-skin side sheet using a cutting roller and an anvil roller positioned opposite the cutting roller. The aforementioned cutting roller has a blade protruding outward from its circumferential surface in the radial direction. The aforementioned anvil roller has a groove recessed inward from the circumferential surface toward the radial direction. A portion of the aforementioned blade presses against the circumferential surface of the aforementioned anvil roller in a manner that forms the aforementioned slit, thereby pressing against the aforementioned absorbent core and the aforementioned non-skin side sheet. Another portion of the blade presses the absorbent core and the non-skin side plate toward the groove in a manner that does not form the slit.

2. The method for manufacturing an absorbent article as described in claim 1, characterized in that, In the slit-forming process described above, the blade presses the absorbent core and the non-skin side sheet from the side where the non-skin side sheet is provided toward the circumferential surface of the anvil roller in the thickness direction.

3. The method for manufacturing an absorbent article as described in claim 2, characterized in that, The aforementioned absorbent article has at least: an absorbent layer comprising the aforementioned absorbent core and the aforementioned non-skin side sheet; and a layer disposed on the skin side closer to the absorbent layer. Compared to the layer located closer to the skin than the aforementioned absorption layer, the average fiber length and average fiber diameter of the aforementioned absorption layer are shorter.

4. The method for manufacturing an absorbent article as described in any one of claims 1 to 3, characterized in that, In the width direction of the aforementioned blade, The end of one side of the aforementioned cutting edge is located at the same position as the end of one side of the aforementioned groove, or at a position one side closer to the end of one side of the aforementioned groove. The other end of the blade is located at the same position as the other end of the groove, or at a position on the other side of the groove.

5. The method for manufacturing an absorbent article as described in any one of claims 1 to 3, characterized in that, The circumferential surface of the aforementioned anvil roller and the boundary of the aforementioned groove are chamfered.

6. The method for manufacturing an absorbent article as described in any one of claims 1 to 3, characterized in that, The above-described slit forming process includes: a first slit forming process for forming a first slit along a direction orthogonal to the transport direction; and a second slit forming process for forming a second slit along the transport direction. In the first slit forming process described above, a portion of the blade presses against the circumferential surface of the anvil roller in a manner that forms the first slit, along with the absorbent core and the non-skin side sheet. Another portion of the blade presses the absorbent core and the non-skin side plate toward the groove in a manner that does not form the first slit.

7. The method for manufacturing an absorbent article as described in claim 6, characterized in that, In the first slit forming process described above, the blade is formed at a predetermined angle relative to the direction orthogonal to the transport direction.

8. The method for manufacturing an absorbent article as described in claim 7, characterized in that, The aforementioned absorbent articles have intersecting front-to-back and width directions. The aforementioned front-to-back direction refers to the direction along the aforementioned transport direction. In the first slit forming process described above, the blade forms the first slit in a manner opposite to the inclination of the first slit relative to the direction orthogonal to the transport direction, at a position one side closer to the center position in the front-back direction of the absorbent article and a position one side closer to the center position.

9. The method for manufacturing an absorbent article as described in claim 6, characterized in that, The cutting roller used in the first slit forming process has a plurality of blades arranged discontinuously along the transport direction. The anvil roller used in the first slit forming process has the groove that is continuous along the transport direction.

10. The method for manufacturing an absorbent article as described in claim 9, characterized in that, The aforementioned absorbent articles have intersecting front-to-back and width directions. The anvil roller has the grooves at both ends of the absorbent article in the width direction.

11. The method for manufacturing an absorbent article as described in claim 10, characterized in that, At both ends of the absorbent article in the width direction, there is no portion where the first slit formed by the first slit forming process intersects with the second slit formed by the second slit forming process.

12. The method for manufacturing an absorbent article as described in claim 6, characterized in that, In the second slit forming process, the slit along the transport direction is formed in such a way that it overlaps with the portion of the blade that did not form the slit in the first slit forming process.

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