Method for manufacturing absorbent body, device for manufacturing absorbent body, and method for manufacturing absorbent article

Abstract

Provided are a method for manufacturing an absorbent body, an apparatus for manufacturing an absorbent body, and a method for manufacturing an absorbent article, with which it is possible to stabilize the quality of the absorbent body when a base material of the absorbent body is compressed by side portions of a convex portion and side portions of a concave portion to form a compressed groove. The method for manufacturing the absorber (30) has a compression step (S20, S50) in which the compression groove is formed in the base material using the convex portion provided on one of a pair of rollers facing each other and the concave portion provided on the other roller. The compression forming portion has a side compression forming portion, which is a portion of a side portion of the convex portion and a side portion of the concave portion where the base material is compressed. In the compression step, the base material is fed in the conveyance direction while being compressed by at least the side compression forming portion. The difference between the feeding speed of the base material on one side of the side compression forming part in the vertical direction and the feeding speed of the base material on the other side of the side compression forming part in the vertical direction is not more than 5%.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an absorbent body, an apparatus for manufacturing an absorbent body, and a method for manufacturing an absorbent article. Background Art

[0002] Patent document 1 discloses a method for manufacturing an absorbent body compressed by a compression forming portion composed of convex portions and concave portions opposing each other. In this manufacturing method, first, a base material of the absorbent body is formed by covering the absorbent core material in a vertical direction with a covering sheet. Next, compression grooves are formed in the base material of the absorbent body using a convex portion of one roller provided in a pair of rollers opposing each other and a concave portion provided in the other roller. Specifically, the base material of the absorbent body is compressed not only by the top of the convex portion and the bottom of the concave portion, but also by the side of the convex portion and the side of the concave portion, thereby forming compression grooves.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6171118 Summary of the invention

[0006] In the manufacturing method of Patent Document 1, compared with the usual manufacturing method of compressing the base material of the absorbent body by using the convex part opposite to the parallel surface, the compression groove is formed more strongly. As a result, there is a possibility that the base material of the absorbent body is damaged when the compression groove is formed. As a result, there is a concern that the quality of the absorbent body is unstable.

[0007] The present invention is completed in view of such problems, and provides a method for manufacturing an absorbent body, a manufacturing device for an absorbent body, and a manufacturing method for an absorbent article, which can stabilize the quality of the absorbent body by compressing the base material of the absorbent body using the side portions of the convex portion and the side portions of the concave portion to form compression grooves.

[0008] A manufacturing method of an absorbent body according to one embodiment is a manufacturing method of an absorbent body having a compression groove formed by compression using a compression forming part composed of convex parts and concave parts facing each other. The manufacturing method has a compression step in which the compression groove is formed in the base material of the absorbent body using the convex part of one roller provided in a pair of rollers facing each other and the concave part provided in the other roller. The compression forming part has a side compression forming part, which is a part of the side part of the convex part and the side part of the concave part that compresses the base material. In the compression step, the base material is sent out in the conveying direction while being compressed by at least the side compression forming part. The difference between the sending speed of the base material on one side of the side compression forming part and the sending speed of the base material on the other side in the vertical direction is within 5%.

[0009] Another embodiment of an absorbent manufacturing device is an absorbent manufacturing device having a compression groove. The manufacturing device comprises: a pair of rollers facing each other; and a compression forming section, which is composed of a convex portion and a concave portion facing each other and compresses the substrate of the absorbent. The compression forming section forms the compression groove on the substrate using the convex portion provided on one roller of the pair of rollers and the concave portion provided on the other roller. The compression forming section comprises a side compression forming section, which is a portion of the side portion of the convex portion and the side portion of the concave portion that compresses the substrate. The substrate is fed out in the conveying direction while being compressed by at least the side compression forming section. The difference between the feeding speed of the substrate on one side of the side compression forming section and the feeding speed of the substrate on the other side in the vertical direction is within 5%.

[0010] Another embodiment of a manufacturing method of an absorbent article is a manufacturing method of an absorbent article having an absorbent body having a compression groove formed by compression using a compression forming section composed of convex parts and concave parts facing each other. The manufacturing method has a compression step in which the compression groove is formed in the base material of the absorbent body using the convex part of one roller provided in a pair of rollers facing each other and the concave part provided in the other roller. The compression forming section has a side compression forming section, which is a part of the side part of the convex part and the side part of the concave part that compresses the base material. In the compression step, the base material is sent out in the conveying direction while being compressed by at least the side compression forming section. The difference between the sending speed of the base material on one side of the side compression forming section and the sending speed of the base material on the other side in the vertical direction is within 5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a plan view of the absorbent article according to the embodiment as viewed from the skin surface side.

[0012] Figure 2 This is a plan view of the absorbent article 1 according to the embodiment as seen from the non-skin surface side.

[0013] Figure 3 It is an absorbent article along Figure 1 A schematic cross-sectional view taken along line AA is shown.

[0014] Figure 4 It is an absorbent article 1 in Figure 3 A schematic cross-sectional view of the range indicated by F4.

[0015] Figure 5 This is a plan view of the absorbent body according to the embodiment as viewed from the skin surface side T1.

[0016] Figure 6 This is a schematic cross-sectional view for explaining a situation in which the absorbent core according to the embodiment receives a force directed inward in the width direction.

[0017] Figure 7 This is a schematic diagram for explaining the movement of the absorbent core when a wearer wears the absorbent article according to the embodiment.

[0018] Figure 8 It is a plan view of the absorbent body 30 according to the modification example as viewed from the skin surface side T1.

[0019] Fig. 9 It is a schematic side view of a part of the production line of the absorbent article 1 according to the embodiment.

[0020] Fig.10 It is a schematic front view of the first compression device 121 according to the embodiment.

[0021] Fig.11 It is a partially enlarged cross-sectional view of the first compression device 121 according to the embodiment.

[0022] Fig.12 It is a diagram for explaining the feeding speed of the substrate 30B.

[0023] Fig.13 This is a partially enlarged cross-sectional view of the first compression device 121 of Modification Example 1.

[0024] Fig.14 It is a partially enlarged cross-sectional view of the first compression device 121 of Modification Example 2 and Modification Example 3.

[0025] Fig.15 It is a diagram for explaining the convex portion C of Modification Example 4.

[0026] Fig.16 It is a schematic front view of the first compression device 121 according to Modification Example 5. DETAILED DESCRIPTION

[0027] (1) Overview of Implementation

[0028] At least the following matters will become clear from the description of this specification and the drawings.

[0029] The manufacturing method of the absorbent body of mode 1 is a manufacturing method of the absorbent body having a compression groove formed by compression using a compression forming part composed of convex parts and concave parts opposite to each other. The manufacturing method has a compression step in which the compression groove is formed in the base material of the absorbent body using the convex part of one roller provided in a pair of rollers opposite to each other and the concave part provided in the other roller. The compression forming part has a side compression forming part, which is a part of the side part of the convex part and the side part of the concave part that compresses the base material. In the compression step, the base material is sent out in the conveying direction while being compressed by at least the side compression forming part. The difference between the sending speed of the base material on one side of the side compression forming part and the sending speed of the base material on the other side in the vertical direction is within 5%.

[0030] As a result of the inventor's in-depth research, it is known that when the substrate of the absorbent body is compressed by the side compression forming part, a relatively fast-transported part and a relatively slow-transported part are generated in the substrate. For example, it is assumed that the substrate is placed on one of a pair of rollers and is transported. For a part on the side of one roller in the side compression forming part (for example, one side of the side compression forming part in the vertical direction), it is closer to the rotation axis of one roller than the part on the side of the other roller in the side compression forming part (for example, the other side of the side compression forming part in the vertical direction), so the substrate is sent out at a relatively slow speed. Therefore, the part of the substrate sent out on one side of the side compression forming part is sent out relatively slowly, and the part of the substrate sent out on the other side of the side compression forming part is sent out relatively quickly. Due to the relative speed difference, a deviation in the transport direction is generated in the substrate. Since the rigidity of the compressed part is high, it is easy to be damaged (especially broken) due to the deviation in the transport direction. Here, by setting the difference in the feed speed of the substrate on one side and the other side of the side compression forming part to within 5%, the deviation in the transport direction between the part that is relatively fast-transported and the part that is relatively slow-transported can be reduced. As a result, damage to the substrate caused by deviation in the transport direction within the substrate (particularly, breakage at the boundary between the portion compressed by the side compression forming section and the uncompressed portion) can be suppressed, and an absorbent body without damage can be easily formed.

[0031] According to a preferred embodiment, the invention of embodiment 2 may have the following features on the basis of the invention of embodiment 1. The shortest distance from the top of the convex portion to the bottom of the concave portion is longer than the shortest distance from the side of the convex portion to the bottom of the concave portion. The force borne by the substrate due to the top of the convex portion and the bottom of the concave portion is relatively weak compared to the force borne by the side compression forming portion. Thus, the force compressed by the side compression forming portion is easily diffused between the top of the convex portion and the bottom of the concave portion, and it is easy to suppress the damage of the substrate. In addition, compared with the portion compressed by the side compression forming portion, the rigidity between the top of the convex portion and the bottom of the concave portion can be reduced, and the deterioration of the wearer's skin touch relative to the portion between the top of the convex portion and the bottom of the concave portion can be reduced.

[0032] According to a preferred embodiment, the invention of embodiment 3 may have the following features on the basis of the invention of embodiment 1 or embodiment 2. A plurality of the compression forming parts are arranged at intervals in the cross direction. The plurality of compression forming parts include a first compression forming part and a second compression forming part arranged next to the first compression forming part in the cross direction. The maximum difference between the feed speed of the substrate of the first compression forming part and the feed speed of the substrate of the second compression forming part is within 5%. Thus, the deviation in the conveying direction of the substrate between the part that is relatively quickly conveyed in the first compression forming part and the part that is relatively slowly conveyed in the second compression forming part can be reduced. As a result, the damage to the substrate caused by the deviation in the conveying direction within the substrate can be suppressed.

[0033] According to a preferred embodiment, the invention of embodiment 4 can have the following features on the basis of the invention of embodiment 3. The lower roller of the pair of rollers having a loading surface on which the substrate can be loaded has an end parallel surface, which is the loading surface parallel to the cross direction and loads the end of the substrate in the cross direction. The maximum distance in the vertical direction of the side compression forming part of each of the plurality of compression forming parts based on the end parallel surface is less than 5% of the radial distance from the rotation axis of the lower roller to the end parallel surface. In the vertical direction, the farther the side compression forming part is from the end parallel surface, the greater the difference between the feed speed of the substrate at the side compression forming part and the feed speed of the substrate at the end parallel surface. By setting the maximum distance of the side compression forming part to less than 5% of the above-mentioned radial distance, the difference in the feed speed of the substrate of each side compression forming part can be reduced. As a result, the damage to the substrate caused by the deviation in the conveying direction within the substrate can be suppressed.

[0034] According to a preferred embodiment, the invention of embodiment 5 may have the following features on the basis of the invention of embodiment 3 or embodiment 4. In the cross direction, the intervals between the plurality of compression forming parts are greater than the height of the convex part in the vertical direction. Since the force applied between the plurality of compression forming parts is not concentrated on the local part of the substrate but is dispersed over a larger range in the cross direction, the deviation in the conveying direction per unit length in the cross direction between the plurality of compression forming parts can be reduced. The situation where the load is concentrated on the local part of the substrate located between the plurality of compression forming parts can be reduced, and the damage to the substrate generated between the plurality of compression forming parts can be suppressed.

[0035] According to a preferred embodiment, the invention of embodiment 6 may have the following features on the basis of any one of the inventions in embodiments 3 to 5. The lower roller of the pair of rollers has a loading surface on which the substrate can be loaded. A central area is provided which is located in the center of the loading surface when the loading surface is divided into five equal parts in the cross direction. In the compression process, any one of the plurality of compression forming parts compresses the substrate in the central area. In the compression process, the compression forming part which compresses the substrate in the central area can press the substrate in the central area, and can suppress the positional deviation of the center of the substrate in the cross direction. As a result, it is possible to suppress the compression at a position different from the target position due to the positional deviation of the substrate.

[0036] According to a preferred embodiment, the invention of embodiment 7 may have the following features on the basis of any one of the inventions in embodiments 3 to 5. The lower roller of the pair of rollers has a loading surface on which the substrate can be loaded. A central region located in the center of the loading surface divided into five equal parts in the cross direction and side regions located on both sides of the central region in the cross direction are provided. In the compression process, the multiple compression forming parts do not compress the substrate in the central region but compress the substrate in the side regions. Since the end of the substrate portion located in the side region that is farther from the central region is a free end, the force generated by the compression is easily diffused on the end side. On the other hand, since the ends on both sides of the substrate portion located in the central region are connected to the substrate portion located in the side region, the force generated by the compression is not easy to diffuse. By compressing the substrate in the side regions instead of the central region by multiple compression forming parts, it is possible to suppress damage to the substrate.

[0037] According to a preferred embodiment, the invention of embodiment 8 may have the following features on the basis of any one of the inventions of embodiments 3 to 7. The one roller has the convex portion of the first compression forming portion and the concave portion of the second compression forming portion. The other roller has the concave portion of the first compression forming portion and the convex portion of the second compression forming portion. The substrate is compressed from one side in the vertical direction using the convex portion of the first compression forming portion of one roller, and the substrate is compressed from the other side in the vertical direction using the convex portion of the second compression forming portion of the other roller. Thus, the substrate is pressed from both sides in the vertical direction, so that positional deviation during transportation can be suppressed. As a result, it is possible to suppress compression at a position different from the target due to positional deviation of the substrate.

[0038] According to a preferred embodiment, the invention of embodiment 9 can have the following features on the basis of any one of the inventions in embodiments 3 to 8. In the lower roller of the pair of rollers having a loading surface on which the substrate can be loaded, the intermediate surface placed between the first compression forming part and the second compression forming part and opposite to the substrate has an inclined loading surface inclined relative to the cross direction. Compared with the case where the intermediate surface is always parallel to the cross direction, the length of the intermediate surface can be extended by an amount corresponding to the height generated by the inclination. Thus, the force applied between the first compression forming part and the second compression forming part will not be concentrated on a local part of the substrate, but will be dispersed over a larger range in the cross direction. Thus, the deviation in the conveying direction per unit length in the cross direction between the first compression forming part and the second compression forming part can be reduced. As a result, the situation where the load is concentrated on a local part of the substrate located between the first compression forming part and the second compression forming part can be reduced, and the damage to the substrate generated between the first compression forming part and the second compression forming part can be suppressed.

[0039] According to a preferred embodiment, the invention of embodiment 10 can have the following features on the basis of any one of the inventions in embodiments 3 to 9. Non-compression forming portions for conveying the substrate without compression are provided on both sides in the cross direction of the compression forming portion. In the lower roller of the pair of rollers having a loading surface on which the substrate can be loaded, the non-compression forming portion has a parallel protruding surface extending parallel to the cross direction from the end of the compression forming portion in the cross direction. Since the distance between the substrate portion on the parallel protruding surface and the rotation axis of the lower roller is constant, the delivery speed of the substrate portion is constant. Therefore, in the substrate portion, no deviation in the conveying direction is generated in the substrate. Therefore, the substrate portion on the parallel protruding surface can be used to absorb the deviation in the conveying direction caused by the difference in the delivery speed of the substrate on one side and the other side of the side compression forming portion. As a result, the damage to the substrate caused by the deviation in the conveying direction in the substrate can be suppressed.

[0040] According to a preferred embodiment, the invention of embodiment 11 may have the following features on the basis of the invention of embodiment 10. The compression forming part is arranged in a plurality at intervals in the cross direction. The plurality of compression forming parts include a first compression forming part and a second compression forming part arranged next to the first compression forming part in the cross direction. The non-compression forming part is provided between the first compression forming part and the second compression forming part. In the lower roller, the non-compression forming part has an intermediate surface, which is arranged between the first compression forming part and the second compression forming part and faces the substrate. In the lower roller, the intermediate surface includes the parallel extension surface and an axis-side parallel surface which is closer to the rotation axis of the lower roller than the parallel extension surface and extends in the cross direction. The average distance in the vertical direction from the axis-side parallel surface to the upper roller of the pair of rollers is longer than the average distance in the vertical direction from the parallel extension surface to the upper roller. As a result, in the axis-side parallel surface, the distance between the upper roller and the lower roller is increased compared with the parallel extension surface, and the substrate is easily moved in the vertical direction on the intermediate surface. Therefore, it is easy to diffuse the force generated by the deviation in the conveying direction between the relatively fast conveyed portion and the relatively slow conveyed portion in the first compression forming portion and the second compression forming portion. As a result, it is possible to suppress the damage of the substrate caused by the deviation in the conveying direction in the substrate.

[0041] According to a preferred embodiment, the invention of embodiment 12 may have the following features on the basis of any one of the inventions in embodiments 1 to 11. In the method for manufacturing an absorbent body, a plurality of small protrusions protruding in the vertical direction are arranged at intervals on the top of the convex portion in the conveying direction. The small protrusions extend along the intersecting direction while being inclined relative to the conveying direction. The small protrusions overlap with the small protrusions adjacent to the small protrusions in the intersecting direction. Thus, while the small protrusions compress the substrate, the adjacent small protrusions begin to compress the substrate, thereby reducing the difference between the force applied by the small protrusions and the force applied to the plurality of small protrusions during the formation of the compression groove. The damage to the substrate caused by the difference in force can be suppressed.

[0042] According to a preferred embodiment, the invention of embodiment 13 may have the following features on the basis of any one of the inventions of embodiments 1 to 12. The manufacturing method of the absorbent body includes a cutting step: after the compression step, the substrate is cut in a manner that the substrate is divided in the conveying direction. The substrate before the division is less likely to move when the compression groove is formed than the cut substrate. Therefore, the compression groove can be easily formed at the target position, and the quality of the absorbent body can be stabilized.

[0043] According to a preferred embodiment, the invention of embodiment 14 may have the following features on the basis of any one of the inventions of embodiments 1 to 13. The method for manufacturing an absorbent body includes a cutting step of cutting the substrate in a manner that divides the substrate in the conveying direction. In the compression step, the compression groove is formed in the cut substrate. Generally speaking, in the cutting step, a force is applied to the substrate when the substrate is cut, so that the substrate expands and contracts. The degree of compression formed on the substrate is likely to be weaker due to the expansion and contraction of the substrate. Here, by forming a compression groove in the cut substrate, it is possible to prevent the degree of compression from being weaker due to the cutting step. The desired compression can be achieved, and the quality of the absorbent body can be stabilized.

[0044] According to a preferred embodiment, the invention of embodiment 15 can have the following features on the basis of any one of the inventions in embodiments 1 to 14. The pair of rollers each has a plurality of roller portions divided in a cross direction. At least one of the compression forming portions is respectively arranged on the plurality of roller portions. In the compression process, the rotation speed of each of the plurality of roller portions is controlled so that the difference in the feed speed of the substrate is within 5%. When the rotation speed of the plurality of roller portions is constant, the feed speed of the substrate varies according to the height of the top of the convex portion of the plurality of compression forming portions, so that the height of the convex portion is limited. On the other hand, by controlling the rotation speed of each of the plurality of roller portions, the difference in the feed speed of the substrate can be made within 1% when the height of the convex portion is not limited, and damage to the substrate caused by deviation in the conveying direction can be suppressed.

[0045] According to a preferred embodiment, the invention of embodiment 16 may have the following features based on the invention of embodiment 15. There are gaps between the plurality of rollers. Thus, the substrate is not pressed from both sides in the vertical direction at the gap between the compression forming portion arranged on the roller and the compression forming portion arranged on another roller adjacent to the roller, so that the force applied to the substrate is easily diffused between the compression forming portions. Thus, damage to the substrate between the compression forming portions can be suppressed.

[0046] According to a preferred embodiment, the invention of embodiment 17 may have the following features. The manufacturing device of the absorbent body of embodiment 17 is a manufacturing device of an absorbent body having a compression groove. The manufacturing device has: a pair of rollers facing each other; and a compression forming portion, which is composed of convex portions and concave portions facing each other, compressing the substrate of the absorbent body. The compression forming portion forms the compression groove on the substrate using the convex portion provided on one roller of the pair of rollers and the concave portion provided on the other roller. The compression forming portion has a side compression forming portion, which is a portion of the side portion of the convex portion and the side portion of the concave portion that compresses the substrate. The substrate is sent out along the conveying direction while being compressed by at least the side compression forming portion. The difference between the sending speed of the substrate on one side of the side compression forming portion in the vertical direction and the sending speed of the substrate on the other side is within 5%.

[0047] According to a preferred embodiment, the invention of embodiment 18 may have the following features. The manufacturing method of the absorbent article of embodiment 18 is a manufacturing method of an absorbent article having an absorbent body, the absorbent body having a compression groove formed by compression using a compression forming part composed of convex parts and concave parts opposite to each other. The manufacturing method has a compression step in which the compression groove is formed on the base material of the absorbent body using the convex part of one roller provided in a pair of rollers opposite to each other and the concave part provided in the other roller. The compression forming part has a side compression forming part, which is a part of the side part of the convex part and the side part of the concave part that compresses the base material. In the compression step, the base material is sent out along the conveying direction while being compressed by at least the side compression forming part. The difference between the sending speed of the base material on one side of the side compression forming part and the sending speed of the base material on the other side in the vertical direction is within 5%.

[0048] (2) Overview of absorbent articles

[0049] Hereinafter, an absorbent article 1 of an embodiment will be described with reference to the accompanying drawings. In addition, in the description of the following drawings, the same or similar parts are marked with the same or similar reference numerals. However, it should be noted that the drawings are schematic diagrams, and the ratios of each dimension are different from the actual situation. Therefore, the specific dimensions should be determined by referring to the following description. In addition, the drawings may include parts with different dimensional relationships and ratios. The absorbent article 1 may be an absorbent article such as a sanitary napkin, a panty liner, an incontinence pad, or a fecal pad. The absorbent article may be an article that is installed on the inside of a wearing article such as underwear for use. The absorbent article 1 of the embodiment is a sanitary napkin for daily use. In addition, in the description of the following drawings, the same or similar parts are marked with the same or similar reference numerals. However, it should be noted that the drawings are schematic diagrams, and there are cases where the ratios of each dimension are different from the actual situation. Therefore, the specific dimensions should be determined by referring to the following description. In addition, there is a case where the drawings may include parts with different dimensional relationships and ratios.

[0050] Figure 1 This is a plan view of the absorbent article 1 as viewed from the skin surface side T1. Figure 2 This is a plan view of the absorbent article 1 as viewed from the non-skin surface side T2. Figure 3 It is along Figure 1 1 is a schematic cross-sectional view of the AA line shown. Here, the "skin-facing side" corresponds to the side facing the skin of the wearer during use. The "non-skin-facing side" corresponds to the side facing the opposite side of the skin of the wearer during use. The absorbent article 1 has a front-to-back direction L, a width direction W, and a thickness direction T that are orthogonal to each other. The side that contacts the lower abdomen of the wearer in the front-to-back direction L of the absorbent article 1 is called the "front side", and the side that contacts the buttocks of the wearer is called the "rear side".

[0051] The absorbent article 1 has a front region, a central region, and a rear region. The central region S2 is disposed between the front region S1 and the rear region S3. The central region S2 may be a region including a region opposite to the excretion opening of the wearer, such as the vaginal opening. When the absorbent article 1 is mounted on a wearing article, the central region S2 may be a region disposed at the crotch of the wearing article and disposed between the legs of the wearer. In the case where the absorbent article 1 has a wing 7 described later, the central region S2 may also be a region from the frontmost front edge of the wing 7 (specifically, the root of the front side) to the rearmost rear edge (specifically, the root of the rear side). In the case where the absorbent article 1 does not have a wing 7 and the absorbent article 1 after manufacture is in a state of being folded in three or four in the front-to-back direction L, the central region S2 may be a region between the first fold and the second fold from the front. In other states and when the absorbent article 1 does not have the wing 7, the central region S2 may be the central region of the region obtained by dividing the absorbent article 1 into three equal parts in the front-back direction L. The front region S1 is located at a position closer to the front side than the central region S2. The front edge of the front region S1 defines the front edge of the absorbent article 1. The rear region S3 is located at a position closer to the rear side than the central region S2. The rear edge of the rear region S3 defines the rear edge of the absorbent article 1.

[0052] The absorbent article 1 has at least an absorbent core 31, a top sheet 10 and a back sheet 20. The absorbent article 1 is in a longitudinal shape. The top sheet 10 is a sheet material that is arranged at a position closer to the skin side T1 than the absorbent core 31 and abuts against the wearer. The top sheet 10 may have: a central sheet 11 that covers the center of the absorbent core 31 in the width direction W; and a side sheet 12 that is arranged at a position closer to the outside in the width direction W than the central sheet 11 and is arranged at least on the wing sheet 7 described later. The side sheet 12 only needs to have a portion that is arranged at a position closer to the width direction W than the central sheet 11, and may overlap with the outer portion of the central sheet 11. The side sheet 12 has a portion that is arranged at a position closer to the outside in the width direction W than the absorbent core 31, and in this embodiment, it is separated from the absorbent core 31 in the width direction W. The central sheet 11 is composed of any sheet-like material having a structure that allows liquid to pass through, such as non-woven fabric, woven fabric, perforated plastic sheet, mesh sheet, etc. The side sheet 12 may be hydrophobic. The material of the side sheet 12 may be the same as that of the central sheet 11. The central sheet 11 and the side sheet 12 may be joined by a sheet joint. The sheet joint may be composed of a compressed portion formed by compressing the central sheet 11 and the side sheet 12, and may be configured to be visually recognizable from the skin surface side T1 of the absorbent article 1. The sheet joint may be composed of an aggregate of dot-shaped compressed portions, and more specifically, may be composed of an aggregate of dot-shaped compressed portions arranged in a rhombus shape and the rhombus shape arranged in the front-back direction L. The sheet joint may extend along the front-back direction L.

[0053] The back sheet 20 is a sheet material that is arranged closer to the non-skin surface T2 than the absorbent core 31 and the fiber sheet 50 and that contacts the wearing article. The back sheet 20 is a liquid-impermeable sheet material. For example, a non-breathable resin film or the like can be used for the back sheet 20.

[0054] The absorbent core 31 constitutes the absorbent body 30. The absorbent core 31 can be made of an absorbent material that absorbs liquid. The absorbent material constituting the absorbent core 31 can be formed of, for example, hydrophilic fibers, pulp, and super absorbent polymers (SAP). The absorbent body 30 can have a core wrap 32 covering the absorbent core 31. The core wrap 32 can be made of, for example, non-woven fabrics or tissue paper. As a modified example, the absorbent core 31 may not be covered by the core wrap 32.

[0055] The absorbent article 1 has a wing 7. When the wing 7 is worn, it is folded back toward the non-skin surface side T2 of the wearing article with the wing fold FL as the base point. At least a top sheet 10 and a back sheet 20 can be arranged on the wing 7. The wing fold FL is defined by the root of the wing 7, and the wing fold FL is a line connecting the part located on the front side and the part located on the rear side of the two parts that are recessed inward in the width direction W. It is also possible that the wing 7 is folded toward the top sheet 10 side before use with the wing fold FL as the base point, and is folded back toward the non-skin surface side T2 of the wearing article when used. A reinforcing sheet 15 can be arranged on the wing 7, and the reinforcing sheet 15 is arranged between the top sheet 10 and the back sheet 20. In addition, in this specification, the term "along the front-back direction L" means a direction having an angle of less than 45° relative to the front-back direction L, and the term "along the width direction W" means a direction having an angle of less than 45° relative to the width direction W.

[0056] like Figure 2 As shown in the figures, the absorbent article 1 has an adhesive portion for fixing the absorbent article 1 to a wearing article such as underwear. The adhesive portion is an area provided on the non-skin surface side T2 of the backsheet 20, and provided with a fixing component for fixing the absorbent article 1 to a wearing article such as underwear. The adhesive portion has a main body adhesive portion 61 for fixing at least the area overlapping with the absorbent core 31 to the wearing article. The main body adhesive portion 61 is provided in the area overlapping with the absorbent core 31 in the thickness direction T of the absorbent article 1. The adhesive portion may have a wing adhesive portion 62 for fixing the wing 7 to the wearing article. The wing adhesive portion 62 is attached to the non-skin surface of the wing 7, and when the wing 7 is folded back to the non-skin surface side T2 of the wearing article when worn, the wing adhesive portion 62 is fixed to the non-skin surface of the wearing article.

[0057] (3) Details of the absorber and compression grooves

[0058] The absorbent body 30 and the compressed grooves 40 according to the embodiment will be described in detail. Figure 4 It is an absorbent article 1 in Figure 3A schematic cross-sectional view of the range indicated by F4 in FIG. Figure 4 In the embodiment, the top sheet 10 and the back sheet 20 are joined in a manner along the shape of the absorbent body 30 . Figure 5 30 is a top view of the absorbent body 30 as viewed from the skin surface side T1. Figure 5 In the figure, a first compressed groove 41, a second compressed groove 42, and a third compressed groove 43 described later are shown, and illustration of other compressed portions of the absorbent body 30 is omitted. Figure 6 This is a schematic cross-sectional view for explaining a situation in which the absorption core 31 receives a force directed inward in the width direction. Figure 7 It is a schematic diagram for explaining the movement of the absorbent core 31 when the wearer WA wears the absorbent article 1. The absorbent core 31A shows an example of the state of the absorbent core 31 when the absorbent article 1 is installed on the wearing article (not shown), the absorbent core 31B shows an example of the state of the absorbent core 31 when the absorbent article 1 installed on the wearing article is slightly pulled up toward the crotch side, and the absorbent core 31C shows an example of the state of the absorbent core 31 when the absorbent article 1 installed on the wearing article is further pulled up toward the crotch side and is located directly below the crotch.

[0059] like Figure 4 and Figure 6 As shown, the absorbent core 31 includes a first absorbent core 311, a second absorbent core 312, and a third absorbent core 313. The first absorbent core 311 is a portion located on the non-skin surface side T2 of the first compressed groove 41 described later. The first absorbent core 311 is a portion overlapping with the first compressed groove 41 in the thickness direction T. The first absorbent core 311 overlaps with at least the bottom surface 41b of the first compressed groove 41 in the thickness direction T. For example, when the side portion of the first compressed groove 41 is inclined relative to the thickness direction T, the first absorbent core 311 overlaps with the side portion of the first compressed groove 41 in the thickness direction T.

[0060] The second absorption core 312 is a portion located on the non-skin surface side T2 of the second compressed groove 42 described later. The second absorption core 312 is a portion overlapping the second compressed groove 42 in the thickness direction T. The second absorption core 312 overlaps at least the bottom surface 42b of the second compressed groove 42 in the thickness direction T. For example, when the side portion of the second compressed groove 42 is inclined relative to the thickness direction T, the second absorption core 312 overlaps the side portion of the second compressed groove 42 in the thickness direction T.

[0061] The third absorption core 313 is a portion located on the skin surface side T1 of the third compressed groove 43 described later. The third absorption core 313 is a portion overlapping with the third compressed groove 43 in the thickness direction T. The third absorption core 313 overlaps with at least the bottom surface 43b of the third compressed groove 43 in the thickness direction T. For example, when the side portion of the third compressed groove 43 is inclined with respect to the thickness direction T, the third absorption core 313 overlaps with the side portion of the third compressed groove 43 in the thickness direction T.

[0062] In addition, the absorbent core 31 has a non-compressed portion 35, which is a part of the absorbent core 31 and is away from the compressed groove 40 in the width direction W. The non-compressed portion 35 is composed of the uncompressed portion of the absorbent core 31. In addition, when the compressed groove 40 is formed, the side portion of the side wall in the width direction W of the compressed groove 40 (particularly the side portion on the bottom surface side of the compressed groove 40) is also affected by compression and the thickness of the side portion changes, so the non-compressed portion 35 is composed of a portion at least 3 mm away from the compressed groove 40 in the width direction W.

[0063] like Figure 1 and Figure 5 As shown, the absorbent core 31 may have at least a high unit weight region HWR arranged in a central front region described later and a low unit weight region LWR having a lower unit weight than the high unit weight region HWR and arranged on the outside in the front-to-back direction L of the high unit weight region HWR. The high unit weight region HWR may be arranged in the central region S2. The high unit weight region HWR may be a region sandwiched by a pair of first compression grooves 41 in the width direction W. The low unit weight region LWR may be arranged in the front side region S1 and the back side region S3. The low unit weight region LWR may be a region on the outside of the pair of first compression grooves 41 in the width direction W. Therefore, the high unit weight region HWR may also be sandwiched by the low unit weight region LWR in the width direction W.

[0064] The central region S2 may have a central front region including an area on the front side of the center of the central region S2 in the front-back direction L. The central front region may be composed of the first region and the second region from the front in the region obtained by dividing the central region S2 into three parts in the front-back direction L. The central front region may be composed of the central region in the region obtained by dividing the absorbent core 31 into three parts in the width direction W. The central front region may be a region opposite to the vaginal opening of the wearer. The high unit area weight region HWR may be configured at least in the central front region.

[0065] like Figure 1 , Figure 4 , Figure 5As shown, the absorbent article 1 has a compression groove 40. The compression groove 40 compresses at least the absorbent core 31 in the thickness direction T and extends in the front-back direction L. The compression groove 40 is arranged at least in the central area S2. In the embodiment, the compression groove 40 has a pair of first compression grooves 41, a pair of second compression grooves 42, and a third compression groove 43.

[0066] The pair of first compressed grooves 41 are arranged so as to compress at least the absorbent core 31 from the skin surface side T1 to the non-skin surface side T2 and sandwich the center of the absorbent core 31 in the width direction W. The pair of second compressed grooves 42 compress at least the absorbent core 31 from the skin surface side T1 to the non-skin surface side T2 and are arranged at positions further outward in the width direction of the absorbent article 1 than the pair of first compressed grooves 41. The third compressed grooves 43 compress at least the absorbent core 31 from the skin surface side T1 to the non-skin surface side T2 and are arranged in the width direction W between the pair of first compressed grooves 41.

[0067] like Figure 4 and Figure 6 As shown, the non-skin surface 311n of the first absorption core 311 is located closer to the non-skin surface side T2 than the non-skin surface 35n of the non-compressed portion 35, and is located closer to the non-skin surface side T2 than the non-skin surface 312n of the second absorption core 312. Therefore, the first absorption core 311 is located on the non-skin surface side T2 of the absorption core 31 between a pair of first compression grooves 41, i.e., the inner absorption core IAC. In addition, the non-skin surface 311n of the first absorption core 311 only needs to be located closer to the non-skin surface side T2 than the non-skin surface 35n of at least one non-compressed portion 35 in the width direction W. Similarly, the non-skin surface 311n of the first absorption core 311 only needs to be located closer to the non-skin surface side T2 than the non-skin surface 312n of the outer second absorption core 312 in the width direction W.

[0068] In addition, for example, the positions of each non-skin surface can be compared by the following method. After the absorbent article 1 serving as a sample is impregnated with liquid nitrogen and frozen, the absorbent article 1 is cut with a razor to obtain a cross section along the thickness direction T and the width direction W, and the cross section is obtained in the top view of the absorbent article 1. Next, the sample is returned to room temperature, and a cross-sectional image with a magnification of 50 times is obtained using an electron microscope (e.g., VE7800 of Keyence Corporation). Then, in the cross-sectional image, the positions of the non-skin surface 311n of the first absorbent core 311, the non-skin surface 35n of the non-compressed portion 35, and the non-skin surface 312n of the second absorbent core 312 are evaluated by visual observation. In addition, the non-skin surface 35n of the non-compressed portion 35 compared with the non-skin surface 311n of the first absorbent core 311 can be, for example, a non-skin surface 35n of a portion located within a range of 3 mm or more and 10 mm or less from the first compression groove 41 in the width direction W and a non-skin surface 35n of an uncompressed portion. The non-skin surface 35n of the non-compressed portion 35 compared with the non-skin surface 312n of the second absorption core 312 can, for example, be a non-skin surface 35n of a portion located within a range of 3 mm to 10 mm from the second compression groove 42 in the width direction W, and is a non-skin surface 35n of an uncompressed portion.

[0069] like Figure 6 As shown in (A), it is assumed that the absorbent core 31 receives a force F inward in the width direction. Figure 6 As shown in (B), the first absorption core 311 is located closer to the non-skin surface side T2 than the non-compressed portion 35 on the outside in the width direction. Therefore, the first absorption core 311 receives a force f1 having a component in the inner side in the width direction and a component in the direction of the non-skin surface side T2 from the non-compressed portion 35. As a result, the first absorption core 311 moves inward in the width direction while moving in the direction of the non-skin surface side T2. Next, the first absorption core 311 applies a force f2 to the non-compressed portion 35 on the inside in the width direction. Specifically, the first absorption core 311 is located closer to the non-skin surface side T2 than the non-skin surface 35n of the non-compressed portion 35 on the inside in the width direction. Therefore, a force f2 having a component in the inner side in the width direction and a component in the direction of the skin surface side T1 is applied to the non-compressed portion 35. Therefore, as shown in FIG. Figure 6 As shown in (C), the first absorbent core 311 easily pushes the non-compressed portion 35 on the inner side in the width direction, that is, the inner absorbent core IAC, from the non-skin surface side T2 to the skin surface side T1 (refer to Figure 7 The result is that, as shown in FIG. Figure 7 As shown, the inner absorbent core IAC can be easily raised toward the skin surface side T1, and the center of the absorbent article 1 in the width direction W can be attached to the excretion opening E of the wearer WA (see Figure 7The absorbent core 31C).

[0070] Here, since the non-skin surface 311n of the first absorption core 311 is located closer to the non-skin surface side T2 than the non-skin surface 312n of the second absorption core 312, at least a portion of the first absorption core 311 (specifically, the portion of the first absorption core 311 located closer to the non-skin surface side T2 than the non-skin surface 312n) is located closer to the non-skin surface side T2 than the second absorption core 312. Therefore, when the absorption core 31 is subjected to the force F directed inward in the width direction, the first absorption core 311 is more likely to push up the absorption core 31 inward in the width direction than the second absorption core 312. As a result, the absorption core 31 is more likely to deform with the first compression groove 41 as the base point than with the second compression groove 42 as the base point, and the desired deformation of the absorption core 31 can be achieved.

[0071] In addition, the second compressed groove 42 is arranged at a position on the outside of the first compressed groove 41 in the width direction W. Therefore, when the absorbent core 31 is subjected to the force F directed inward in the width direction, the shrinkage of the absorbent core 31 between the first compressed groove 41 and the second compressed groove 42 can be suppressed. As a result, it is difficult to produce the shrinkage of the absorbent core 31 on the outside of the first compressed groove 41 in the width direction, which is the deformation base point, and the side leakage of excrement can be suppressed. In this way, it is possible to achieve both the fit of the absorbent article 1 in the width direction center and the suppression of the side leakage of excrement.

[0072] It can be, for example Figure 5 As shown, the first compression groove 41 extends linearly along the front-to-back direction L. At least the portion of the first compression groove 41 arranged in the central area S2 can extend linearly along the front-to-back direction L. As a result, at least in the central area S2, the position of the first compression groove 41 in the width direction W is the same, so in the central area S2, when the absorbent core 31 is subjected to the force F toward the inner side in the width direction, the force will not be concentrated on the part of the first compression groove 41, and it is easy to apply force to the first compression groove 41 as a whole. As a result, in the central area S2, it is easy to make the inner absorbent core IAC bulge toward the skin surface side T1 in a larger range, and the desired deformation of the absorbent core 31 can be achieved.

[0073] In addition, the first compression groove 41 may extend continuously or intermittently from the front edge of the absorbent core 31 to the rear edge. In the embodiment, the first compression groove 41 extends continuously from the front edge of the absorbent core 31 to the rear edge. Compared with the case where the first compression groove 41 does not extend from the front edge to the rear edge of the absorbent core 31, when the absorbent core 31 is subjected to the force F toward the inner side in the width direction, the first absorbent core 311 is easy to withstand the force F toward the inner side in the width direction. As a result, it is easy to make the inner absorbent core IAC bulge toward the skin surface side T1, and the desired deformation of the absorbent core 31 can be achieved.

[0074] The first compression groove 41 may extend from the high unit weight region HWR to the low unit weight region LWR. In the embodiment, the first compression groove 41 extends from the high unit weight region HWR to the low unit weight region LWR of the front region S1. In addition, the first compression groove 41 extends from the high unit weight region HWR to the low unit weight region LWR of the rear region S3. In addition, when the absorption core 31 is compressed to form the first compression groove 41, by continuously arranging the first compression groove 41 in the front-to-back direction L, it is possible to set the first compression groove 41 to extend from the high unit weight region HWR to the low unit weight region LWR of the rear region S3. Since the absorption core 31 is continuously compressed, the position of the absorption core 31 is stable, so that the first compression groove 41 can be stably arranged, which can suppress the degradation of quality.

[0075] In the front-to-back direction L, the length of the first compression groove 41 may be longer than the length of the wing piece 7. In addition, in the front-to-back direction L, the length of the first compression groove 41 may be longer than the length of the second compression groove 42. In the front-to-back direction L, the first compression groove 41 is arranged in a larger range than the second compression groove 42. In addition, the portion of the first compression groove 41 where the second compression groove 42 does not exist on the outer side in the width direction W is more likely to bear the force F toward the inner side in the width direction. Therefore, it is easy to make the inner absorption core IAC bulge toward the skin surface side T1 in a larger range, and the desired deformation of the absorption core 31 can be achieved.

[0076] The first compression groove 41 may overlap with the main body adhesive portion 61 in the thickness direction T. Since the main body adhesive portion 61 is located on the non-skin surface side T2 of the first absorbent core 311, the first absorbent core 311 is not easily moved to the non-skin surface side T2, and the inner absorbent core IAC can be easily raised to the skin surface side T1 accordingly.

[0077] It can be, for example Figure 5As shown, in the top view of the absorbent article 1, when the absorbent core 31 is divided into four equal parts in the width direction W, a pair of outer regions OR located on the outside in the width direction W and an inner region IR located between the pair of outer regions OR are provided. Here, the first compression groove 41 can be located in the inner region IR. The inner region IR corresponds to two parts of the absorbent core 31 obtained by dividing into four equal parts in the width direction W. Since the first compression groove 41 is located in the inner region IR, the width of the absorbent core 31 between the first compression grooves 41, that is, the inner absorbent core part IAC is smaller than half of the width of the absorbent core 31. Therefore, compared with the case where the width of the inner absorbent core part IAC is more than half of the width of the absorbent core 31, the inner absorbent core part IAC that bulges toward the skin surface side T1 can be made smaller, and the deformation range of the absorbent core 31 based on the first compression groove 41 does not increase. Excessive deformation of the absorbent core 31 can be prevented, and it is not easy to cause discomfort to the wearer. In addition, since the inner absorption core IAC is small, it is easy to enter the crotch of the wearer. As a result, the inner absorption core IAC can be brought closer to the excretion opening of the wearer. Furthermore, the area outside the first compression groove 41 in the width direction, which is the deformation base point, can be ensured to be larger. As a result, the side leakage of excrement can be suppressed.

[0078] It can be, for example Figure 4 As shown, in the cross section of the absorbent article 1 along the width direction W and the thickness direction T, the width W1 of the first compressed groove 41 is wider than the thickness T5 of the non-compressed portion 35. Therefore, when the absorbent core 31 is deformed with the first compressed groove 41 as a base point, the absorbent core portion on one side of the first compressed groove 41 and the absorbent core portion on the other side of the first compressed groove 41 do not collide in the width direction W, and the deformation of the absorbent core 31 can be less hindered. As a result, the inner absorbent core portion IAC can be easily raised toward the skin surface side T1, and the desired deformation of the absorbent core 31 can be achieved.

[0079] In the embodiment, the bottom surface 41b of the first compression groove 41 is composed of the core wrap sheet 32. The bottom surface 41b of the first compression groove 41 may also be composed of the absorbent core 31. In addition, in the first compression groove 41, the top sheet 10 is not compressed. Thus, since the top sheet 10 is not compressed, the bottom surface 41b of the first compression groove 41 is not composed of the top sheet 10. If compared with the rigidity of the compressed portion, the rigidity of the non-compressed portion of the top sheet 10 is low, so even if the top sheet 10 on the first compression groove 41 touches the excretion opening (e.g., vaginal opening), it is not easy to cause discomfort to the wearer.

[0080] The depth D1 of the bottom surface 41b of the first compressed groove 41 in the high unit weight region HWR can be deeper than the depth D1 of the bottom surface 41b of the first compressed groove 41 in the low unit weight region LWR. Therefore, in the high unit weight region HWR arranged in the central front area, the bottom surface 41b of the first compressed groove 41 is relatively deep, so it is easy to make the inner absorption core IAC bulge toward the skin surface side, and in the low unit weight region LWR, the bottom surface 41b of the first compressed groove 41 is relatively shallow, so compared with the high unit weight region HWR, the inner absorption core IAC is not easy to bulge. As a result, in areas other than the high unit weight region HWR, it is not easy to locally touch the inner absorption core IAC, which is not easy to cause discomfort to the wearer. In addition, if Figure 4 As shown, the depth D1 of the bottom surface 41b of the first compressed groove 41 is the distance in the thickness direction T from the opening edge of the first compressed groove 41 to the bottom surface 41b (the skin surface of the core wrap sheet 32 ​​on the skin surface side T1 of the absorbent core 31 in the embodiment).

[0081] Furthermore, the first compressed groove 41 may be disposed at the boundary between the high unit weight region HWR and the low unit weight region LWR in the width direction W. Generally, since the rigidity of the absorbent core 31 in the high unit weight region HWR is higher than that in the low unit weight region LWR, a rigidity difference can be generated with the first compressed groove 41 as the boundary, and deformation can be easily achieved with the first compressed groove 41 as the base point.

[0082] The bottom surface 41b of the first compression groove 41 can be located at a position closer to the non-skin surface side T2 than the non-skin surface 35n of the non-compressed portion 35. As a result, the first absorption core 311 is located as a whole at the non-skin surface side T2 of the inner absorption core IAC of the non-compressed portion 35. Therefore, when the first absorption core 311 is subjected to the force F toward the inner side of the width direction and moves inward in the width direction, it is easy to push the inner absorption core IAC further from the non-skin surface side T2 to the skin surface side T1. As a result, it is easy to make the inner absorption core IAC bulge toward the skin surface side T1. In addition, the bottom surface 41b of the first compression groove 41 can be located at a position closer to the non-skin surface side T2 than the non-skin surface of the portion of the core wrap sheet 32 ​​that contacts the non-skin surface 35n of the non-compressed portion 35 in the thickness direction T.

[0083] It can also be, Figure 5As shown, the second compression groove 42 is composed of a collection of multiple point-shaped compression parts. Specifically, in the second compression groove 42, multiple point-shaped compression parts can be arranged adjacent to each other (for example, within 3 mm). Thus, in the top view of the absorbent article 1, the part that is recessed from the skin surface side to the non-skin surface side can extend linearly along the front-to-back direction L as the second compression groove 42. As a modified example, the second compression groove 42 can also be composed of a continuously extended compression part. Specifically, the second compression groove 42 can also be composed of a continuously compressed part extending along the front-to-back direction L.

[0084] In the top view of the absorbent article 1, the second compression groove 42 may extend in a curved shape. Thus, compared with the case where the second compression groove 42 extends in a straight line along the front-to-back direction L, in the width direction W, the width direction distance between the position of the innermost inner edge of the second compression groove 42 and the position of the outermost outer edge becomes longer. Thus, the width direction length of the second compression groove 42 can be ensured, and compared with the linear second compression groove 42, the shrinkage of the absorbent core 31 can be suppressed in accordance with the amount of the width direction length. In addition, in an embodiment, in the top view of the absorbent article 1, the second compression groove 42 is annular. Thus, the front ends of a pair of second compression grooves 42 are connected to each other, and the rear ends of a pair of second compression grooves 42 are connected to each other. The pair of second compression grooves 42 are respectively arc-shaped. As a modified example, the second compression groove 42 may also be linear.

[0085] In addition, in the top view of the absorbent article 1, the distance between the first compressed groove 41 and the second compressed groove 42 in the width direction W is relatively long on the central side in the front-back direction L, and the distance between the first compressed groove 41 and the second compressed groove 42 in the width direction W is relatively short on the outer side in the front-back direction L. On the central side in the front-back direction L, the force toward the inner side in the width direction W is strong, so although the absorbent core 31 is easy to shrink, the shrinkage of the absorbent core 31 can be suppressed at a position farther than the first compressed groove 41 that serves as the deformation base point. In addition, in the central area S2, a pair of first compressed grooves 41 are arranged inside the annular second compressed groove 42, thereby, the second compressed groove 42 is arranged at a position closer to the outer side in the width direction W than the pair of first compressed grooves 41.

[0086] In addition, the portion of the second compression groove 42 that overlaps at least with the central front region in the width direction W may be located in each outer region OR of a pair of outer regions OR. That is, the second compression groove 42 may be located in the outer region OR at a position that is further outward in the width direction W than the central front region. By the portion of the second compression groove 42 that is arranged in the outer region OR, the shrinkage of the absorbent core 31 can be suppressed in the outer region OR. Since the outer region OR is located at a position that is further outward in the width direction than the inner region IR, it is not easy to cause the shrinkage of the absorbent core 31 that is further outward in the width direction than the first compression groove 41 that serves as the deformation base point. It is possible to ensure a larger absorption area for excrement in the width direction outside of the central front region where excrement is likely to leak. In addition, at a position that is further outward in the front-rear direction L than the central front region, the second compression groove 42 may be arranged in either the outer region OR or the inner region IR.

[0087] like Figure 4 As shown, in the embodiment, the bottom surface 42b of the second compressed groove 42 is formed by the top sheet 10. In addition, the bottom surface 42b of the second compressed groove 42 can also be formed by the absorbent core 31 or the core wrapping sheet 32 ​​by tearing the top sheet 10 due to compression. Figure 4 As shown, the bottom surface 42b of the second compression groove 42 is located at a position closer to the skin surface side T1 than the non-skin surface 35n of the non-compression portion 35. Thus, at least a part of the second absorption core 312 is located at a position closer to the skin surface side T1 than the non-compression portion 35. Here, as described above, the non-skin surface 311n of the first absorption core 311 is located at a position closer to the non-skin surface side T2 than the non-skin surface 32n of the second absorption core 312. Therefore, when the second absorption core 312 receives the force F toward the inner side in the width direction, it is easy to move the absorption core 31 between the first compression groove 41 and the second compression groove 42 in the direction from the skin surface side T1 toward the non-skin surface side T2. As a result, the first absorption core 311 can easily withstand the force f1 in the direction from the skin side T1 toward the non-skin side T2. For the absorption core 31, it is easier to deform with the first compression groove 41 as the base point than to deform with the second compression groove 42 as the base point, thereby achieving the desired deformation of the absorption core 31.

[0088] In the embodiment, the third compression groove 43 at least compresses the absorbent core 31 from the non-skin side T2 to the skin side T1. In addition, the third compression groove 43 is arranged between a pair of first compression grooves 41 in the width direction W. As a result, the third absorbent core 313 can be easily moved to a position closer to the skin side T1 than the non-compressed portion 35 when subjected to a force toward the inside in the width direction, and the inner absorbent core IAC can be easily raised toward the skin side T1 with the third compression groove 43 as the vertex (see Figure 7 As a result, it is easy to fit the inner absorption core IAC to the excretion opening E.

[0089] It can be, for example Figure 4 As shown, the skin surface 313s of the third absorption core 313 is located at a position closer to the skin surface side T1 than the skin surface 35s of the non-compressed portion 35. As a result, the portion of the third absorption core 313 located at a position closer to the skin surface side T1 than the skin surface 35s of the non-compressed portion 35 receives a force in the direction of pushing from the non-skin surface side T2 to the skin surface side T1 from the non-compressed portion 35 adjacent to the third absorption core 313, so that the third absorption core 313 is easy to move to the skin surface side T1. As a result, it is easy to make the inner absorption core IAC bulge toward the skin surface side T1 with the third compression groove 43 as the vertex, and the desired deformation of the absorption core 31 can be achieved. In addition, similarly to the above, the positional relationship between the skin surface 313s of the third absorption core 313 and the skin surface 35s of the non-compressed portion 35 can be evaluated by visual observation using an electron microscope (e.g., VE7800 of Keyence Corporation). The non-skin surface 35n of the non-compressed portion 35 is a non-skin surface 35n located at a distance of at least 3 mm to 10 mm from the third compression groove in the width direction W and is an uncompressed non-skin surface 35n.

[0090] It can be, for example Figure 4 As shown, the depth D3 of the bottom surface 43b of the third compressed groove 43 is deeper than the depth D1 of the bottom surface 41b of the first compressed groove 41. Therefore, the absorbent core 31 is more easily deformed in the third compressed groove 43 than in the first compressed groove 41. As a result, it is easy to make the inner absorbent core IAC bulge toward the skin surface T1 with the third compressed groove 43 as the vertex, and it is easy to make the inner absorbent core IAC fit the excretion port E. In addition, as Figure 4 As shown, the depth D3 of the bottom surface 43b of the third compression groove 43 is the distance in the thickness direction T from the opening edge of the third compression groove 43 to the bottom surface 43b (in the embodiment, it is the non-skin surface of the core wrap sheet 32 ​​on the non-skin surface side T2 of the absorbent core 31).

[0091] The third compression groove 43 may not overlap with the main body adhesive portion 61 in the thickness direction T. Thus, the movement of the third absorption core 313 toward the skin surface side T1 is not hindered by the main body adhesive portion 61, and the third absorption core 313 can easily move toward the skin surface side T1. As a result, the inner absorption core IAC can be easily raised toward the skin surface side T1 with the third compression groove 43 as the vertex.

[0092] like Figure 4As shown, in an embodiment, in the 1st compression groove 41 and the 3rd compression groove 43, the absorbent core 31 and the core wrap sheet 32 ​​are compressed. In the 1st compression groove 41 and the 3rd compression groove 43, the top sheet 10 is not compressed. Thus, in the 1st compression groove 41 and the 3rd compression groove 43, the top sheet 10 is not compressed and at least the absorbent core 31 is compressed. Under the situation that the 1st compression groove 41 is formed in a manner that the non-skin surface 311n of the 1st absorbent core 311 is located at the position of the non-skin surface 35n of the non-compressed part 35 by the non-skin surface side T2, if compared with the situation that is not the situation, then it is necessary to compress strongly. But, when forming the 1st compression groove 41, the top sheet 10 is not compressed, so there is no worry that the top sheet 10 is torn. As a result, even if the top sheet 10 contacts the excretion port E due to the bulging of the inner absorption core IAC toward the skin surface side T1, there is no tearing of the top sheet 10 caused by the formation of the first compression groove 41, which can not easily cause discomfort to the wearer. In addition, when the user visually recognizes the top sheet 10, he will not feel that the absorbent article 1 is a defective product, which can suppress the decline in the quality of the absorbent article 1.

[0093] On the other hand, in the second compressed grooves 42, the top sheet 10 is compressed in addition to the absorbent core 31 and the core wrap sheet 32. In the first compressed grooves 41 and the third compressed grooves 43, the absorbent core 31 and the top sheet 10 are compressed together.

[0094] The tensile strength in the width direction W of the top sheet 10 can be below 10N / 25mm. By making the tensile strength of the top sheet 10 lower, the softness of the top sheet 10 can be ensured. As a result, even if the top sheet 10 contacts the excretion port E due to the inner absorbent core IAC bulging toward the skin surface side T1, it is not easy to bring discomfort to the wearer.

[0095] Tensile strength can be measured by the following method.For example, the top sheet 10 is removed from the absorbent article 1. The top sheet 10 is cut in a 25mm mode with a length on the front-back direction L of the top sheet 10. The cut top sheet 10 is placed in a tensile testing machine (Autograph AGS-1kNG: Shimadzu Corporation), set to a distance between chucks of 100mm. Under a state where one side on the width direction W of the cut top sheet 10 is fixed, stretch to the other side on the width direction W of the top sheet 10. The stretching speed is 100mm / minute. The maximum value of the tensile force when the top sheet 10 is broken is measured as tensile strength. Utilize 5 samples to carry out the same measurement, and use their average value as tensile strength (N / 25mm). The tensile strength of the top sheet 10 of length 25mm is evaluated. Since the length of the top sheet 10 is based on 25mm, the denominator of the unit is 25mm.

[0096] The width of the second compression groove 42 may be wider than the width of the first compression groove 41. In addition, the width of the second compression groove 42 may be wider than the width of the third compression groove 43. Thus, the shrinkage of the absorbent core can be suppressed by the amount of the width of the second compression groove 42 being wider. In addition, in the top view of the absorbent article 1, the width of the compression groove 40 is the distance from one side wall to the other side wall of the compression groove 40 in the direction orthogonal to the extension direction of the compression groove 40. In addition, the width of the first compression groove 41 may be wider than the width of the third compression groove 43. Thus, in the first compression groove 41, compared with the third compression groove 43, the absorbent cores 31 are less likely to collide with each other. In the first compression groove 41, the deformation of the absorbent core 31 can be less likely to be hindered, and the inner absorbent core portion IAC can be easily raised toward the skin surface side T1. In addition, the width of the third compression groove 43 may be wider than the width of the first compression groove 41. Thus, the absorbent cores 31 are less likely to collide with each other in the third compressed grooves 43 than in the first compressed grooves 41. The deformation of the absorbent core 31 is less likely to be hindered, and the inner absorbent core can be easily raised toward the skin surface side with the third compressed grooves 43 as apexes.

[0097] In the first absorption core 311, relatively high rigidity parts and relatively low rigidity parts may be alternately arranged in the front-to-back direction L. Thus, the absorption core is easily bent in the front-to-back direction L with the low rigidity parts as base points, so that the absorbent article 1 can be easily made to follow the wearer's body in the front-to-back direction L. In addition, the third absorption core 313 may have the same rigidity as the first absorption core 311.

[0098] In addition, it can also be, Figure 1 As shown in the figure, in the absorbent article 1, the positions other than the compression groove 40 are compressed. For example, in the top view of the absorbent article 1, the inner side of the annular second compression groove 42 may be compressed in a dotted manner. In addition, a plurality of dot-shaped compression portions may be arranged on a line at a position outside the second compression groove 42 in the front-back direction L. In these compression portions, in addition to compressing the absorbent core 31 and the core wrap sheet 32, the top sheet 10 is also compressed, similarly to the second compression groove 42.

[0099] (4) Absorber of Modification Example

[0100] The absorbent body 30 of the modified example will be described. The differences from the above-described embodiment will be mainly described. Figure 8 : is a top view of the absorbent body 30 of the modification example as viewed from the skin surface side T1. Figure 8 In the figure, the first compressed groove 41 and the third compressed groove 43 are shown, but the second compressed groove 42 is not shown.

[0101] like Figure 8As shown in the figure, in the absorbent body 30 (absorbent article 1), the first compressed grooves 41 extend intermittently in the front-to-back direction L. As a result, in the front-to-back direction L, the rigidity between the first compressed grooves 41 (first intermittent portions 41i described later) is low, so the absorbent core 31 is easy to bend in the front-to-back direction L between the first compressed grooves 41 in the front-to-back direction L. As a result, the absorbent core 31 can be easily bent in the front-to-back direction L along the body of the wearer, and the absorbent core 31 can be easily fitted to the body of the wearer.

[0102] Similar to the first compressed grooves 41 , the third compressed grooves 43 also extend intermittently in the front-rear direction L. Therefore, similar to the first compressed grooves 41 , the absorption core 31 can be easily bent along the wearer's body in the front-rear direction L, and the absorption core 31 can easily fit the wearer's body.

[0103] The first compression groove 41 and the third compression groove 43 may respectively extend intermittently along the front-to-back direction L at a position on the outside of the central front region in the front-to-back direction L. In the modified example, the first compression groove 41 is not arranged in the region overlapping with the central front region in the width direction W (or the thickness direction T). On the other hand, the third compression groove 43 is arranged in the region overlapping with the central front region in the width direction W (or the thickness direction T). In addition, the first compression groove 41 may also be arranged only at a position not overlapping with the high unit weight region HWR in the thickness direction T. On the other hand, the first compression groove 41 may also be arranged at a position overlapping with the high unit weight region HWR in the thickness direction T. In addition, in the modified example, the region other than the high unit weight region HWR is the low unit weight region LWR.

[0104] In addition, the absorbent article 1 (absorbent body 30) may have a plurality of compressed groove portions (hereinafter referred to as first compressed groove portions 41p) constituting the first compressed groove 41 and one or more intermittent portions (hereinafter referred to as first intermittent portions 41i) between the plurality of first compressed groove portions 41p. In the front-to-back direction L, the total length of the plurality of first compressed groove portions 41p may be longer than the total length of the one or more first intermittent portions 41i. Thus, the absorbent core 31 can be easily bent along the wearer's body in the front-to-back direction L, and the ease of deformation of the absorbent core 31 with the first compressed groove 41 as the base point can be ensured, and the desired deformation of the absorbent core 31 can be achieved. In addition, the total length of the one or more first intermittent portions 41i may not include the length of the first intermittent portion 41i that is longer than the length of one first compressed groove portion 41p in the front-to-back direction L. For example, the total length of the one or more first intermittent portions 41i may not include the length of the first intermittent portion 41i that overlaps with the high unit area weight region HWR in the thickness direction T.

[0105] In addition, the absorbent article 1 (absorbent body 30) may include a plurality of compressed groove portions (hereinafter referred to as third compressed groove portions 43p) constituting the third compressed grooves 43 and one or more intermittent portions (hereinafter referred to as third intermittent portions 43i) between the plurality of third compressed groove portions 43p. In the front-back direction L, the total length of the plurality of third compressed groove portions 43p may be longer than the total length of the one or more third intermittent portions 43i.

[0106] The position of the first intermittent portion 41i may be offset from the position of the third intermittent portion 43i in the front-rear direction L. Therefore, the first intermittent portion 41i and the third intermittent portion 43i may not overlap in the width direction W, or only a portion of the first intermittent portion 41i may overlap in the width direction W with the third intermittent portion 43i.

[0107] In this modification, the first intermittent portion 41i is located at a position closer to the front side than the third intermittent portion 43i. Here, the rigidity of the first intermittent portion 41i is lower than that of the first compression groove 41, and the rigidity of the third intermittent portion 43i is lower than that of the third compression groove 43. Therefore, at a position further back than the central front area, the absorbent core 31 is easy to bend along a line passing through the first intermittent portion 41i and the third intermittent portion 43i (i.e., a line L13 that goes toward the outside in the width direction W as it goes toward the front side in the front-back direction L). As a result, the absorbent core 31 can be easily bent along the buttocks, and the leakage of excrement to the rear of the wearer can be further suppressed.

[0108] In other modified examples, the first intermittent portion 41i may be located at a position further back than the third intermittent portion 43i. In this case, the absorbent core 31 is easily bent along a line passing through the first intermittent portion 41i and the third intermittent portion 43i (i.e., a line that moves toward the inside in the width direction as it moves toward the front side in the front-back direction) at a position further forward than the central front region. As a result, the absorbent core 31 can be easily bent along the abdomen, and leakage of excrement to the front of the wearer can be further suppressed.

[0109] The length of the first intermittent portion 41i in the front-to-back direction L may be longer than the length of the second intermittent portion 42i in the front-to-back direction L. Thus, the first compressed groove 41 is more likely to receive a force directed inwardly in the width direction W than the second compressed groove 42, and is more likely to deform with the first compressed groove 41 as a base point. In addition, the length of the third intermittent portion 43i in the front-to-back direction L may be longer than the length of the second intermittent portion 42i in the front-to-back direction L. Thus, the third compressed groove 43 is more likely to receive a force directed inwardly in the width direction W than the second compressed groove 42, and is more likely to deform with the third compressed groove 43 as a base point.

[0110] Furthermore, when there are a plurality of first intermittent portions 41i, the first intermittent portion 41i closest to the third intermittent portion 43i is targeted with respect to the positional relationship between the first intermittent portion 41i and the third intermittent portion 43i in the front-rear direction L. Similarly, when there are a plurality of third intermittent portions 43i, the third intermittent portion 43i closest to the first intermittent portion 41i is targeted with respect to the positional relationship between the first intermittent portion 41i and the third intermittent portion 43i in the front-rear direction L.

[0111] (5) Apparatus for manufacturing absorbent body

[0112] The manufacturing apparatus 100 of the absorbent body 30 according to the embodiment will be described. Fig. 9 It is a schematic side view of a part of the production line of the absorbent article 1 according to the embodiment. Fig.10 It is a schematic front view of the first compression device 121 according to the embodiment. Fig.11 It is a partially enlarged cross-sectional view of the first compression device 121 according to the embodiment. Fig.12 It is a diagram for explaining the feeding speed of the base material 30B of the absorbent body.

[0113] like Fig. 9 As shown, in this embodiment, the manufacturing device 100 of the absorbent body 30 has a compression device 120. The manufacturing device 100 may further include a substrate forming device 110 and a cutting device 130. The substrate forming device 110 forms the substrate of the absorbent body. For example, in the substrate forming device 110, the substrate 30B of the absorbent body 30 is formed by covering the absorbent core 31M with a covering sheet in the vertical direction TD. Alternatively, in another embodiment, the manufacturing device 100 does not include a substrate forming device, but performs a compression process on the substrate (for example, an air-laid pulp sheet) of the pre-formed absorbent body using a compression device 120 or the like. The substrate forming device 110 includes a rotating drum 111 and a supply unit 112 for supplying the absorbent core 31M to the outer peripheral surface of the rotating drum 111. The compression device 120 forms a compression groove 40 on the substrate of the absorbent body 30. The cutting device 130 cuts the substrate 30B of the absorbent body 30 in a manner that the substrate 30B is divided along the conveying direction MD. The cutting device 130 is composed of a rotating drum having a cutting blade for cutting the substrate 30B. The cutting blade is installed on the outer peripheral surface of the rotating drum. In addition, the manufacturing device 100 has a conveying direction MD (Machine Direction), a cross direction CD (Cross Direction) orthogonal to the conveying direction MD, and a vertical direction TD (Transverse Direction) orthogonal to the conveying direction MD and the cross direction CD.

[0114] like Fig. 9As shown, in the embodiment, the compression device 120 includes a first compression device 121 and a second compression device 122. The first compression device 121 forms the first compression groove 41 and the third compression groove 43. The second compression device 122 forms the second compression groove 42.

[0115] The first compression device 121 includes a pair of rollers consisting of an upper roller 121U and a lower roller 121L. Fig.10 As shown, the upper roller 121U and the lower roller 121L are opposite to each other. The upper roller 121U rotates around the rotation axis CU parallel to the cross direction CD. The lower roller 121L rotates around the rotation axis CL parallel to the cross direction CD. The lower roller 121L has a loading surface PS on which the substrate 30B of the absorbent body can be loaded. The loading surface PS is at least a part of the outer peripheral surface of the lower roller 121L.

[0116] The first compression device 121 has a compression forming portion PF composed of a convex portion C and a concave portion R facing each other. The convex portion C has a top portion Ct and side portions Cs located on both sides of the top portion Ct in the direction CD crossing the top portion Ct. The concave portion R has a bottom portion Rb and side portions Rs located on both sides of the bottom portion Rb in the direction CD crossing the bottom portion Rb.

[0117] In this embodiment, the compression forming portion PF includes a side compression forming portion PFs and a central compression forming portion PFc. The side compression forming portion PFs is a portion of the base material 30B of the absorbent body compressed between the side portion Cs of the convex portion C and the side portion Rs of the concave portion R. The central compression forming portion PFc is a portion of the base material 30B of the absorbent body compressed by the top portion Ct of the convex portion C and the bottom portion Rb of the concave portion R.

[0118] In the embodiment, a plurality of compressed forming portions PF are arranged at intervals in the cross direction CD. Fig.10As shown, the plurality of compression forming parts PF include a first compression forming part PF1, a second compression forming part PF2, and a third compression forming part PF3. The second compression forming part PF2 is arranged next to the first compression forming part PF1 on one side in the cross direction CD, and is arranged next to the third compression forming part PF3 on the other side in the cross direction CD. The first compression forming part PF1 and the third compression forming part PF3 are arranged at positions offset in the cross direction CD relative to the center of the upper roller 121U and the lower roller 121L in the cross direction CD. The second compression forming part PF2 is arranged at the center of the upper roller 121U and the lower roller 121L in the cross direction CD. The upper roller 121U is provided with a convex portion C1 of the first compression forming part PF1, a concave portion R2 of the second compression forming part PF2, and a convex portion C3 of the third compression forming part PF3. The lower roller 121L is provided with a concave portion R1 of the first compression forming portion PF1, a convex portion C2 of the second compression forming portion PF2, and a concave portion R3 of the third compression forming portion PF3. In the vertical direction TD, the convex portion C1 faces the concave portion R1, the convex portion C2 faces the concave portion R2, and the convex portion C3 faces the concave portion R3.

[0119] In addition, in the first compression device 121, non-compression forming parts NP for conveying the substrate 30B of the absorbent body without compression are provided on both sides of the compression forming part PF in the cross direction CD. In the embodiment, the non-compression forming part NP is provided between the first compression forming part PF1 and the second compression forming part PF2, and between the second compression forming part PF2 and the third compression forming part PF3. In addition, the non-compression forming part NP is provided at a position on the outside of the first compression forming part PF1 in the cross direction CD, and is provided at a position on the outside of the third compression forming part PF3 in the cross direction CD.

[0120] Reference Fig.11 The structures of the convex portion C and the concave portion R are described. The convex portion C1 of the first compressed portion PF1 has a top portion C1t and side portions C1s located on both sides of the top portion C1t in the cross direction CD. The concave portion R1 of the first compressed portion PF1 has a bottom portion R1b and side portions R1s located on both sides of the bottom portion R1b in the cross direction CD.

[0121] The first compression forming portion PF1 has a first side compression forming portion PF1s and a first center compression forming portion PF1c. The first side compression forming portion PF1s is a portion of the base material 30B compressed in the side portion C1s of the convex portion C1 and the side portion R1s of the concave portion R1. The first side compression forming portion PF1s has an end portion PF1sa on one side and an end portion PF1sb on the other side in the vertical direction TD. In the convex portion C1, the end portion PF1sa is an end portion on the top C1t side, and the end portion PF1sb is an end portion on the side away from the top C1t. In the concave portion R1, the end portion PF1sa is an end portion on the bottom R1b side, and the end portion PF1sb is an end portion on the side away from the bottom R1b. On the other hand, the first center compression forming portion PF1c is a portion of the base material 30B compressed by using the top C1t of the convex portion C1 and the bottom R1b of the concave portion R1. In the convex portion C1, both ends of the first central compression forming portion PF1c in the cross direction CD are connected to the end portions PF1sa of the first side compression forming portion PF1s. The second compression forming portion PF2 and the third compression forming portion PF3 are the same as the first compression forming portion PF1.

[0122] As described later, in the compression process, the substrate 30B is compressed by at least the side compression forming part PFs and the substrate 30B is fed out in the feeding direction MD. Here, the difference between the feeding speed of the substrate on one side of the side compression forming part PFs and the feeding speed of the substrate on the other side in the vertical direction TD is within 5%. As a result of intensive research by the inventors, it is found that when the substrate 30B is compressed by the side compression forming part PFs, a relatively fast fed portion and a relatively slow fed portion are generated in the substrate 30B.

[0123] For example, it is assumed that the substrate 30B of the absorbent body is placed on one roller (hereinafter referred to as the lower roller 121L) of a pair of rollers and is transported. Fig.12As shown, the end PF1sa on one side of the first side compression forming portion PF1s is closer to the rotation axis CL of the lower roller 121L than the end PF1sb on the other side, so the feeding speed V1a of the substrate 30B at the end PF1sa is relatively slow, and the feeding speed V1b of the substrate 30B at the end PF1sb is relatively fast. Specifically, the distance from the end PF1sa to the rotation axis CL is set to r1a, the distance from the end PF1sb to the rotation axis CL is set to r1b, and the difference between the end PF1sb and the end PF1sa is set to D1. The feeding speed V is represented by the product of the distance (radius) from the rotation axis CL to the predetermined position of the roller and the angular velocity of the roller, and a relative speed difference ΔV1 corresponding to the difference D1 is generated. Therefore, the portion of the substrate 30B sent out at the end PF1sa of the first side compression forming portion PF1s is sent out relatively slowly, and the portion of the substrate 30B sent out at the end PF1sb of the first side compression forming portion PF1s is sent out relatively quickly. Based on the relative speed difference ΔV1, a deviation in the conveying direction MD occurs in the substrate 30B. Since the rigidity of the compressed portion is high, it is easy to be damaged (especially broken) due to the deviation in the conveying direction MD.

[0124] Here, in the manufacturing method of the absorbent body 30, the difference ΔV between the feed speeds of the substrate 30B on one side (e.g., the end PF1sa) and the other side (e.g., the end PF1sb) of the side compression forming part PFs is set to within 5%. Specifically, the difference ΔV1 between the feed speeds of the substrate 30B in the first side compression forming part PF1s is set to within 5%. In addition, the difference ΔV2 between the feed speed V2a of the substrate 30B at the end PF2sa and the feed speed V2b of the substrate 30B at the end PF2sb in the second side compression forming part PF2s is set to within 5%. Thus, the deviation in the conveying direction MD between the portion that is relatively quickly conveyed and the portion that is relatively slowly conveyed can be reduced. As a result, the damage of the substrate 30B caused by the deviation in the conveying direction MD in the substrate 30B (particularly the disconnection at the boundary between the portion compressed by the side compression forming part PFs and the uncompressed portion) can be suppressed, and an absorbent body 30 without damage can be easily formed. In addition, in order to prevent the substrate 30B from being deformed in the conveying direction MD, it is preferable that the difference ΔV between the feed speeds of the substrate 30B on one side and the other side of the side compression forming portion PFs be within 4%. More preferably, the difference ΔV between the feed speeds of the substrate 30B on one side and the other side of the side compression forming portion PFs be within 1.5%. For example, the difference ΔV between the feed speeds of the substrate 30B may be 1.01%.

[0125] In addition, if Fig.11As shown, the shortest distance Lc from the top Ct of the convex part C (for example, the top C2t) to the bottom Rb of the concave part R (for example, the bottom R2b) is longer than the shortest distance Ls from the side Cs of the convex part C (for example, the side C2s) to the side Rs of the concave part R (for example, the side R2s). The force received by the base material 30B from the top Ct and the bottom Rb is relatively weak compared with the force received from the side compression forming part PFs. As a result, the rigidity of the portion compressed by the top Ct and the bottom Rb can be reduced, and the deterioration of the skin touch of the wearer relative to this portion can be reduced.

[0126] In addition, the maximum difference between the feed speed of the substrate 30B of the first compression forming part PF1 and the feed speed of the substrate 30B of the second compression forming part PF2 can be within 5%. Specifically, the difference between the end PF1sa of the first compression forming part PF1 and the end PF2sb of the second compression forming part PF2 can be within 5%. As a result, the deviation in the conveying direction of the portion of the substrate 30B that is relatively quickly conveyed and the portion that is relatively slowly conveyed in the first compression forming part and the second compression forming part can be reduced. As a result, the damage of the substrate 30B caused by the deviation in the conveying direction MD in the substrate 30B can be suppressed. In addition, in order to prevent the substrate 30B from being deformed in the conveying direction MD, the maximum difference between the feed speed of the substrate 30B of the first compression forming part PF1 and the feed speed of the substrate 30B of the second compression forming part PF2 can be within 4%, preferably within 1.5%. For example, the maximum difference in the above speed can be 1.01%. In addition, the maximum difference between the feeding speed of the substrate 30B of the second compression forming section PF2 and the feeding speed of the substrate 30B of the third compression forming section PF3 may be the same. The above-mentioned maximum difference may be within 5%. In addition, the difference between the maximum feeding speed and the minimum feeding speed of the substrate 30B of the plurality of compression forming sections PF may be the same.

[0127] like Fig.10 and Fig.11 As shown, in the lower roller 121L, the non-compressed forming portion NP has an end parallel surface EPS, which is a loading surface PS parallel to the cross direction CD and can load the end of the substrate 30B in the cross direction CD. In addition, in this embodiment, in the lower roller 121L, the loading surface PS of each non-compressed forming portion NP located between the plurality of compressed forming portions PF is parallel to the cross direction CD.

[0128] The maximum distance Md of the side compression forming parts PFs of each of the multiple compression forming parts PF in the vertical direction TD with the end parallel surface EPS as the reference BL can be less than 5% of the radial distance r from the rotation axis CL of the lower roller 121L to the end parallel surface EPS. The maximum distance Md is preferably less than 2.5% of the radial distance r, and more preferably less than 1.1% of the radial distance r. In the vertical direction TD, the farther the side compression forming part PFs is from the end parallel surface EPS, the greater the difference between the feed speed of the substrate 30B at the side compression forming part PFs and the feed speed of the substrate 30B at the end parallel surface EPS. By setting the maximum distance Md of the side compression forming part PFs to less than 5% of the radial distance r, the difference in the feed speed of the substrate 30B of each side compression forming part PFs can be reduced. As a result, damage to the substrate 30B caused by deviations in the conveying direction MD within the substrate 30B can be suppressed. In addition, as Fig.11 As shown, for example, in the vertical direction TD, the end of the first side compression forming part PFs1 that is farthest from the reference BL is the end PF1sa, so the maximum distance Md1 of the first side compression forming part PFs1 is the distance from the reference BL to the end PF1sa of the first side compression forming part PF1s in the recess R1. Similarly, the maximum distance Md2 of the second side compression forming part PFs2 is the distance from the reference BL to the end PF2sa of the second side compression forming part PF2s in the recess R2. Therefore, the maximum distance Md1 and the maximum distance Md2 can be less than 5% of the radial distance r.

[0129] In addition, the spacing between the plurality of compression forming parts PF in the cross direction CD may be greater than the height of the convex portion C in the vertical direction TD. Thus, the force applied between the plurality of compression forming parts PF will not be concentrated on the local part of the substrate 30B, but will be dispersed over a larger range in the cross direction CD, thereby reducing the deviation in the conveying direction MD per unit length in the cross direction CD between the plurality of compression forming parts PF. The situation where the load is concentrated on the local part of the substrate 30B located between the plurality of compression forming parts PF can be reduced, and the damage to the substrate 30B generated between the plurality of compression forming parts PF can be suppressed. In addition, in order to prevent the substrate 30B from being deformed in the conveying direction MD, the spacing between the plurality of compression forming parts PF is preferably more than twice the height of the convex portion C, and more preferably more than 5 times.

[0130] It can be, for example Fig.10As shown, there is provided a central region located in the center when the placing surface PS is divided into five equal parts in the cross direction CD, and side regions SR located on both sides of the central region CR in the cross direction CD. It may be that any one of the plurality of compression forming portions PF is located in the central region CR. Thus, it may be that any one of the plurality of compression forming portions PF compresses the substrate 30B in the central region CR. In the compression process described later, the compression forming portion PF that compresses the substrate 30B in the central region CR can press the center of the substrate 30B in the cross direction CD, and can suppress the positional deviation of the center of the substrate 30B. As a result, it is possible to suppress the situation in which compression at a position different from the target due to the positional deviation of the substrate 30B. In the embodiment, the second compression forming portion PF2 is located in the central region CR, and the first compression forming portion PF1 and the third compression forming portion PF3 are located in the side regions SR.

[0131] In addition, in the modified example, the plurality of compression forming parts PF may not compress the substrate 30B in the central region CR. The plurality of compression forming parts PF may not compress the substrate 30B in the central region CR but compress the substrate 30B in the side region SR of the central region CR. Since the end of the substrate portion located in the side region SR that is farther from the central region CR is a free end, the force generated by compression is easy to spread on the side of the end. On the other hand, since the ends on both sides of the substrate portion located in the central region CR are connected to the substrate portion located in the side region, the force generated by compression is not easy to spread. By compressing the substrate 30B in the side region SR instead of the central region CR by the plurality of compression forming parts PF, the damage of the substrate 30B can be suppressed. In addition, the plurality of compression forming parts PF may not compress the substrate 30B in only one side region SR but in two side regions SR. Since the plurality of compression forming parts PF press the substrate 30B from both sides in the cross direction CD, the force is not easy to concentrate on one side in the cross direction CD. This makes it easier to strike a balance when conveying the substrate 30B, and can suppress positional deviation during conveyance. As a result, it is possible to suppress compression at a position different from the target due to positional deviation of the substrate 30B.

[0132] In addition, the upper roller 121U as one roller may have a convex portion C1 of the first compression forming portion PF1 and a concave portion R2 of the second compression forming portion PF2. The lower roller 121L as another roller may have a concave portion R1 of the first compression forming portion PF1 and a convex portion C2 of the second compression forming portion PF2. Thus, the substrate 30B is compressed from one side in the vertical direction TD using the convex portion C1 of the first compression forming portion PF1, and the substrate 30B is compressed from the other side in the vertical direction TD using the convex portion C2 of the second compression forming portion PF2. Thus, the substrate 30B is pressed from both sides in the vertical direction TD, so that positional deviation during transportation can be suppressed. As a result, it is possible to suppress compression at a position different from the target due to positional deviation of the substrate 30B.

[0133] Furthermore, in the manufacturing apparatus 100 of the absorbent body 30, when the rotation speed of the upper roller 121U and the rotation speed of the lower roller 121L are set to the maximum value, the difference between the feeding speed of the substrate 30B on one side of the side compression forming portion PFs in the vertical direction TD and the feeding speed of the substrate on the other side may be 5% or more. The manufacturer may control the rotation speed of the upper roller 121U and the rotation speed of the lower roller 121L so that the difference in the feeding speed is within 5% according to the type of the absorbent body 30 to be manufactured.

[0134] The second compression device 122 has a pair of rollers consisting of an upper roller 122U and a lower roller 122L facing each other. The upper roller 122U rotates around a rotation axis CU parallel to the cross direction CD. The lower roller 121L rotates around a rotation axis CL parallel to the cross direction CD. The second compression device 122 compresses the substrate 30B using a convex portion (not shown) facing the parallel surface. The upper roller 122U is provided with a convex portion, and the lower roller 121L is provided with a parallel surface.

[0135] (6) Method for manufacturing absorbent body

[0136] The manufacturing method of the absorbent body 30 is described. In the present embodiment, the manufacturing method of the absorbent body 30 has a first compression step S20. The manufacturing method may also have a base material forming step S10, a cutting step S30, a top sheet configuration step S40, and a second compression step S50. In the present embodiment, the first compression step S20 and the second compression step S50 are included in the compression step. In other embodiments, the manufacturing method may not have a base material forming step.

[0137] In the substrate forming step S10, the substrate 30B of the absorbent body 30 is formed. More specifically, in the substrate forming step S10, the absorbent material for absorbing body fluids, i.e., the absorbent core 31M, may be stacked to form the substrate 30B of the absorbent body 30, or the absorbent material may be formed into a sheet to form the substrate 30B of the absorbent body 30, or the substrate 30B of the absorbent body 30 may be formed by covering one side of the absorbent core 31M in the vertical direction with a covering sheet, or the substrate 30B of the absorbent body 30 may be formed by covering both sides of the absorbent core in the vertical direction with a covering sheet. Preferably, in the substrate forming step S10, the covering sheet substrate (e.g., the substrate 32B of the core wrap sheet 32) may be used for covering in the vertical direction TD. Fig.11 As shown, the base material 32B1 of the core wrap sheet 32 ​​disposed on the non-skin surface side T2 is transported by a conveying unit such as a belt conveyor. The absorbent core 31M is placed on the transported base material 32B1 from the rotating drum 111. Next, the base material 32B2 of the core wrap sheet 32 ​​disposed on the skin surface side T1 is placed on the absorbent core 31M. As a result, both sides of the absorbent core 31M in the vertical direction are covered by the base material 32B of the core wrap sheet 32 ​​corresponding to the covering sheet in the vertical direction TD. As a result, the base material 30B of the absorbent body 30 is formed.

[0138] In the first compression step S20, the compression grooves 40 are formed in the substrate 30B using the convex portion C provided on one roller of the pair of rollers and the concave portion R provided on the other roller. Fig.11 As shown, the upper roller 121U and the lower roller 121L rotate, so that in the first compression forming section PF1, the substrate 30B is compressed by the convex portion C1 and the concave portion R1. Specifically, in the first compression forming section PF1, the substrate 30B is compressed by the side compression forming section PFs and the center compression forming section PFc. Thus, the first compression groove 41 is formed in the substrate 30B. Similarly, in the third compression forming section PF3, the substrate 30B is compressed by the convex portion C3 and the concave portion R3. Thus, the first compression groove 41 is formed in the substrate 30B. In addition, in the first compression process, the second compression groove 42 is not formed.

[0139] In the first compression step S20, the substrate 30B is fed out in the conveying direction MD while being compressed by at least the side compression forming part PFs. In addition, in the present embodiment, the substrate 30B is fed out in the conveying direction MD while being compressed by the side compression forming part PFs, and the substrate 30B is fed out in the conveying direction MD while being compressed by the center compression forming part PFc. The difference between the feeding speed of the substrate 30B on one side of the side compression forming part PFs and the feeding speed of the substrate 30B on the other side is within 5%.

[0140] In the cutting step S30, the substrate 30B is cut in such a manner that the substrate 30B is divided in the conveying direction MD. Specifically, the substrate 30B is cut by the cutter blade by the rotation of the rotary drum. In the present embodiment, the substrate 30B is cut after the first compression step S20. The substrate 30B before the division is less likely to move when the compression groove 40 is formed than the cut substrate 30B. Therefore, the compression groove 40 can be easily formed at the target position, and the quality of the absorbent body 30 can be stabilized.

[0141] In the top sheet disposing step S40, the base material 10B of the top sheet 10 is disposed on the base material 30B of the absorbent body 30. Fig. 9 As shown, in this embodiment, the base material 30B (base material 32B1) of the absorbent body 30 is covered with the base material 10B of the top sheet 10 in the vertical direction TD. Therefore, the base material 10B of the top sheet 10 is arranged on the upper side of the base material 30B.

[0142] In the second compression step S50, in addition to compressing the base material 30B using the convex portion C of one roller provided on a pair of rollers and the concave portion R provided on the other roller, the base material 10B of the top sheet 10 is also compressed using these to form the compression groove 40. In this embodiment, as Fig.11 As shown in FIG. 1 , the substrate 30B and the substrate 10B are compressed by the rotation of the upper roller 122U and the lower roller 122L. The second compression groove 42 is formed by pressing the convex portion (not shown) provided on the upper roller 122U against the flat outer peripheral surface of the lower roller 122L. In addition, since the compression is performed by the convex portion of the upper roller 122U and the flat outer peripheral surface of the lower roller 122L, the absorbent body 30 is less likely to be damaged compared to the first compression step S20. Therefore, the difference between the feed speed of the substrate 30B at the top of the convex portion provided on the upper roller 122U and the feed speed of the substrate 30B at the side of the convex portion can be 5% or more.

[0143] Afterwards, other components (such as the reinforcing sheet 15, the substrate of the back sheet 20, etc.) are arranged on the substrate 30B formed with the second compression groove 42, and the intermediate product arranged with the other components is cut, thereby manufacturing the absorbent article 1. In addition, other processes can also be performed between the above-mentioned processes. For example, the process of forming a dot-shaped compression portion on the substrate 32B1 can be performed between the substrate forming process S10 and the first compression process S20, or between the first compression process S20 and the cutting process S30. The process for compressing the substrate 10B of the top sheet 10 and the substrate 30B of the absorbent body 30 can be arranged between the top sheet arrangement process S40 and the second compression process S50, or after the second compression process S50.

[0144] In addition, as a modification, the first compression step S20 may be performed after the cutting step S30. Therefore, the cut substrate 30B may be formed with either the first compression groove 41 or the third compression groove 43. Generally speaking, in the cutting step S30, a force is applied to the substrate when the substrate 30B is cut, so that the substrate expands and contracts. The degree of compression formed on the substrate 30B is likely to be weaker due to the expansion and contraction of the substrate 30B. Here, by forming a compression groove in the cut substrate 30B, it is possible to prevent the degree of compression from being weaker due to the cutting step S30. The desired compression can be achieved, and the quality of the absorbent body 30 can be stabilized.

[0145] (7) Absorbent Manufacturing Apparatus of Modified Example

[0146] A manufacturing apparatus 100 of the absorbent body 30 according to a modified example will be described. In addition, the description will be mainly focused on the parts different from the above-mentioned embodiment, and the description of the same parts will be omitted. Fig.13 This is a partially enlarged cross-sectional view of the first compression device 121 of Modification Example 1. Fig.13 is with Fig.11 Same cross-section view. Fig.14 It is a partially enlarged cross-sectional view of the first compression device 121 of Modification Example 2 and Modification Example 3. Fig.14 (A) is a partially enlarged cross-sectional view of the first compression device 121 of Modification Example 2. Fig.14 (B) is a partially enlarged cross-sectional view of the first compression device 121 of Modification Example 3. Fig.15 It is a diagram for explaining the convex portion C of Modification Example 4. Fig.15 (A) is a diagram for explaining the convex portion C. Fig.15 (B) is along Fig.15 (A) is a schematic cross-sectional view taken along line F15B-F15B. Fig.16 It is a schematic front view of the first compression device 121 according to Modification Example 5.

[0147] It can also be, Fig.13 As shown in the figure, the compression forming part PF does not have a central compression forming part PFc, but has only a side compression forming part PFs. Therefore, the shortest distance Lc from the top Ct of the convex part C to the bottom Rb of the concave part R can be longer than the thickness (i.e., the length in the vertical direction TD) of the base material 30B of the absorbent body 30. As a result, the central side of the compression groove 40 in the width direction W is not compressed, so the force compressed by the side compression forming part PFs is easily diffused, and the damage of the base material 30B can be suppressed.

[0148] It can be, for example Fig.14As shown in (A), in the first compression device 121, in the lower roller 121L, the non-compression forming part NP has an intermediate surface IS, and the intermediate surface IS is arranged between the first compression forming part PF1 and the second compression forming part PF2, and is opposite to the substrate 30B. The intermediate surface IS is a part of the outer peripheral surface of the lower roller 121L. The intermediate surface IS can have a parallel protruding surface EXS and an axial side parallel surface AS. The intermediate surface IS can be, for example, a surface from the end of the recessed portion R1 of the first compression forming part PF1 (the opening edge of the recessed portion R1) to the end of the convex portion C2 of the second compression forming part PF2 (the root of the convex portion C2). In addition, it can also be, as Fig.14 As shown in (A), the plane connecting the parallel projecting surface EXS and the axis-side parallel surface AS is a plane extending parallel to the crossing direction CD and is orthogonal to the parallel projecting surface EXS and the axis-side parallel surface AS.

[0149] The parallel extension surface EXS is a surface extending parallel to the cross direction CD from the end of the compression forming portion PF in the cross direction CD. In addition, when the compression forming portion PF is a recessed portion R, the end of the compression forming portion PF in the cross direction CD may be the opening edge of the recessed portion (for example, the end PF1sb of the first side compression forming portion PF1s), and when the compression forming portion PF is a convex portion C, the end of the compression forming portion PF in the cross direction CD may be the root of the convex portion C. For example, the parallel extension surface EXS may be formed from one end of the first compression forming portion PF1 of the lower roller 121L (at Fig.14 In (A), the end PF1sb of the first side compression forming part PF1s extends parallel to the second compression forming part PF2. The length Le in the cross direction CD of the parallel extension surface EXS can be longer than the depth of the recess R (i.e., the height in the vertical direction TD from the parallel extension surface EXS to the bottom Rb), and preferably can be more than twice the depth of the recess R.

[0150] The axis-side parallel surface AS is a surface that is closer to the rotation axis CL of the lower roller 121L than the parallel extension surface EXS and extends in a narrowing manner along the cross direction CD. Fig.14 As shown in (A), when the shaft-side parallel surface AS is a surface extending parallel to the cross direction CD from the end of the second compression forming portion PF2 in the cross direction CD in the lower roller 121L, it coincides with the parallel extended surface EXS extending from the second compression forming portion PF2.

[0151] The average distance from the axis-side parallel surface AS to the upper roller 121U in the vertical direction TD may be longer than the average distance from the parallel extension surface EXS to the upper roller 121U in the vertical direction TD. Fig.14In (A), the average value of the distance Di from the axial side parallel surface AS to the upper roller 121U in the vertical direction TD can be greater than the average value of the distance De from the parallel extension surface EXS to the upper roller 121U in the vertical direction TD. Therefore, a space can be provided in the non-compression forming part NP for the substrate 30B to move freely to a certain extent in the vertical direction TD. As a result, in the axial side parallel surface AS, the distance between the upper roller 121U and the lower roller 121L is increased compared to the parallel extension surface EXS, and the substrate 30B is easy to move in the vertical direction TD on the intermediate surface IS. Therefore, the force generated by the deviation in the conveying direction MD between the relatively fast conveyed part and the relatively slow conveyed part in the first compression forming part PF1 and the second compression forming part PF2 is easy to spread. As a result, the damage of the substrate 30B caused by the deviation in the conveying direction within the substrate 30B can be suppressed.

[0152] In addition, it can be, Fig.14 As shown in (A), the height of the bottom Rb of the lower roller 121L in the vertical direction TD with the end parallel surface EPS as the reference BL is less than 5% of the radius distance r from the rotation axis CL of the lower roller 121L to the end parallel surface EPS. The height of the bottom Rb with the end parallel surface EPS as the reference BL is preferably less than 2.5% of the radius distance r, and more preferably less than 1.1% of the radius distance r. Fig.14 In (A), the height of the bottom R1b and the bottom R3b is consistent with the parallel extension surface EXS, which is 0% of the radius r. Similarly, the height of the top Ct of the lower roller 121L in the vertical direction TD with the end parallel surface EPS as the reference BL can be less than 5% of the radius r. The height of the top Ct with the end parallel surface EPS as the reference BL is preferably less than 2.5% of the radius r, and more preferably less than 1.1% of the radius r. Fig.14 In (A), the height of the top Ct is consistent with the parallel extension surface EXS, which is 0% of the radial distance r. With the end parallel surface EPS as the reference BL, the bottom Rb and the top Ct provided on the lower roller 121L may also be located at a height within 5% of the radial distance r. Thus, when the compression groove 40 is formed in the first compression step S20, the substrate 30B does not shift significantly in the vertical direction TD in the range from one side to the other side in the cross direction CD of the substrate 30B, and damage to the substrate 30B can be suppressed.

[0153] In addition, it can be, Fig.14 As shown in (A), in the lower roller 121L, the concave portion R is farther from the rotation axis CL in the vertical direction TD than the convex portion C. Therefore, the concave portion R may be arranged at a position higher than the convex portion in the vertical direction TD. In this case, the parallel extension surface EXS may extend from both ends of the concave portion R in the cross direction CD.

[0154] In addition, it can be, Fig.14 As shown in (B), in the lower roller 121L, the intermediate surface IS has an inclined mounting surface INS that is inclined relative to the cross direction CD. Compared with the case where the intermediate surface IS is always parallel to the cross direction CD, the length of the intermediate surface IS can be extended by an amount corresponding to the height caused by the inclination. For example, Fig.11 implementation and Fig.14 In the modification example (B), the lengths of the first compressed and formed portion PF1 and the second compressed and formed portion PF2 in the cross direction CD are the same. Fig.11 In the embodiment, the length of the intermediate surface (parallel extension surface EXS) arranged between the first compression forming portion PF1 and the second compression forming portion PF2 and always parallel to the cross direction CD is equal to the length in the cross direction CD between the first compression forming portion PF1 and the second compression forming portion PF2. Fig.14 In (B), the length of the intermediate surface IS is the sum of the length (Le) of the parallel extension surface EXS on the first compression forming portion PF1 side in the cross direction CD, the length of the inclined mounting surface INS, and the length of the parallel extension surface EXS on the second compression forming portion PF2 side in the cross direction CD. Here, when the length of the inclined mounting surface INS in the cross direction CD is a and the length of the inclined mounting surface INS in the perpendicular direction TD is b, the length of the inclined mounting surface INS is expressed as (a). 2 +b 2 ) 1 / 2 It means that it is greater than the length a in the cross direction CD of the inclined mounting surface INS. Fig.14 (B) The length ratio of the intermediate surface IS Fig.11 The length of the middle surface (parallel extension surface EXS) in the substrate 30B is longer by an amount corresponding to the height caused by the inclination. As a result, the force applied between the first compression forming part PF1 and the second compression forming part PF2 will not be concentrated on a local part of the substrate 30B, but will be dispersed over a larger range in the cross direction. As a result, the deviation in the conveying direction MD per unit length in the cross direction CD between the first compression forming part PF1 and the second compression forming part PF2 can be reduced. As a result, the situation in which the load is concentrated on a local part of the substrate located between the first compression forming part PF1 and the second compression forming part PF2 can be reduced, and the damage to the substrate generated between the first compression forming part PF1 and the second compression forming part PF2 can be suppressed. Furthermore, when the substrate 30B is transported while being supported on the inclined loading surface INS, the positional deviation of the substrate 30B during transportation can be suppressed. In addition, the angle of the inclined loading surface INS relative to the cross direction CD is preferably 10 degrees to 30 degrees.

[0155] In addition, it can be, Fig.15As shown in FIG. 1 , a plurality of small protrusions SC protruding in the vertical direction TD are arranged at intervals on the top Ct of the convex portion C in the conveying direction MD. The small protrusions SC may extend in the cross direction CD while being inclined relative to the conveying direction MD. The small protrusions SC may overlap with the small protrusions SC adjacent to the small protrusions SC in the cross direction CD. Specifically, it may be, for example, Fig.15 As shown in (A), the small protrusion SC has a first small protrusion SC1 and a second small protrusion SC2. The second small protrusion SC2 is adjacent in the conveying direction MD. Here, in the conveying direction MD, the rear end edge SC1b of the first small protrusion SC1 can be located behind the front end edge SC1a of the second small protrusion SC2. Thus, while the small protrusion SC compresses the substrate 30B, the adjacent small protrusion SC begins to compress the substrate 30B, thereby reducing the difference between the force applied by the small protrusion SC and the force applied between the small protrusion SC and the small protrusion SC during the formation of the compression groove 40. The damage to the substrate 30B caused by the difference in force can be suppressed. In addition, it may be, as Fig.15 As shown in (A), the inclination angle α of the small protrusion SC with respect to the conveying direction MD may be 30 degrees to 60 degrees.

[0156] In addition, it can be, Fig.15 As shown in (B), the rear side surface SCr of the small protrusion SC in the conveying direction MD is inclined relative to the cross direction CD. The inclination angle β between the rear side surface SCr and the top Ct of the convex portion C can be greater than 90 degrees. Therefore, the rear side surface SCr of the small protrusion SC can be inclined in a manner that the closer it is to the rotation axis CL from the top of the small protrusion SC in the cross direction CD, the more it is located at the rear. As a result, the small protrusion SC of the compressed substrate 30B is easy to detach from the substrate 30B, which can further suppress the slight damage of the substrate 30B. In addition, the front side surface of the small protrusion SC in the conveying direction MD can also be inclined relative to the cross direction CD. The inclination angle between the front side surface and the top Ct of the convex portion C can be greater than 90 degrees. As a result, the small protrusion SC of the compressed substrate 30B can be easily detached from the substrate 30B.

[0157] In addition, it can be, Fig.16As shown, a pair of rollers each have a plurality of roller portions divided in the cross direction CD. For example, the upper roller 121U may have a first upper roller portion 121U1, a second upper roller portion 121U2, and a third upper roller portion 121U3. The lower roller 121L may have a first lower roller portion 121L1, a second lower roller portion 121L2, and a third lower roller portion 121L3. At least one compression forming portion PF may be arranged on each of the plurality of roller portions. Each roller portion may be controlled to be able to rotate at a different rotational speed. Thus, in the compression process, the rotational speed of each of the plurality of roller portions may be controlled so that the difference in the delivery speed of the substrate 30B between the plurality of compression forming portions PF is within 5%.

[0158] Specifically, when the second lower roller 121L2 having the convex portion C2 rotates at a predetermined speed, the rotation speed of the first lower roller 121L1 having the concave portion R1 and the rotation speed of the third lower roller 121L3 having the concave portion R3 may be faster than the predetermined speed. Each upper roller may have the same rotation speed as the corresponding lower roller. When the rotation speed of each lower roller can only be controlled to be constant, the feed speed of the substrate varies according to the height of the top Ct (specifically, the convex portion C1, the convex portion C2, and the convex portion C3) of the convex portion C of the plurality of compression forming portions PF. In the convex portion C2, the substrate 30B is fed relatively quickly, and in the convex portion C1 opposite to the concave portion R1 and the convex portion C3 opposite to the concave portion R3, the substrate 30B is fed relatively slowly. Therefore, the height of the convex portion C is limited in such a way that the difference in the feed speed of the substrate 30B is small. Here, by controlling the rotation speed of each of the plurality of rollers, the difference in the feed speed of the substrate 30B can be kept within 1% without limiting the height of the convex portion C, thereby suppressing damage to the substrate 30B caused by deviation in the conveyance direction MD.

[0159] In addition, it can be, Fig.16 As shown in FIG. 1 , there is a gap G between the plurality of roller portions. Thus, the substrate 30B is not pressed from both sides in the vertical direction TD at the gap G between the compression forming portion PF disposed on the roller portion and the compression forming portion PF disposed on another roller portion adjacent to the roller portion, so that the force applied to the substrate 30B is easily diffused between these compression forming portions PF. Thus, damage to the substrate 30B between these compression forming portions PF can be suppressed.

[0160] The present invention has been described in detail using the above-mentioned embodiments, but it is self-evident to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as a modification and alteration mode without departing from the gist and scope of the present invention as defined by the claims. Therefore, the description of this specification is for the purpose of illustration and does not have any restrictive meaning on the present invention.

[0161] In addition, the entire contents of Japanese Patent Application No. 2022-099252 filed on June 20, 2022 are incorporated into this specification by reference.

[0162] Industrial Applicability

[0163] According to the present invention, when the compressed grooves are formed by compressing the base material of the absorbent body using the side portions of the convex portions and the side portions of the concave portions, the quality of the absorbent body can be stabilized.

[0164] Description of Reference Numerals

[0165] 1. absorbent article; 30. absorbent body; 40. compression groove; 41. first compression groove; 42. second compression groove; 43. third compression groove; 100. manufacturing device; C, convex portion; R, concave portion; PF, compression forming portion; PFs, side compression forming portion; MD, conveying direction; CD, cross direction; TD, vertical direction.

Claims

1. A method for manufacturing an absorbent body having a compressed groove formed by compression forming a compression forming portion composed of a convex portion and a concave portion facing each other, wherein: The method for manufacturing an absorbent body comprises a compressing step of forming the compressed grooves in the base material of the absorbent body by using the convex portion of one roller provided in a pair of rollers facing each other and the concave portion provided in the other roller, The compression forming portion includes a side compression forming portion, which is a portion of the side portion of the convex portion and the side portion of the concave portion that compresses the base material. In the compression step, the substrate is fed out in a conveying direction while being compressed by at least the side compression forming portion. A difference between a feeding speed of the substrate on one side and a feeding speed of the substrate on the other side of the side compression forming portion in the vertical direction is within 5%.

2. The method for producing an absorbent body according to claim 1, wherein: The shortest distance from the top of the convex portion to the bottom of the concave portion is longer than the shortest distance from the side of the convex portion to the bottom of the concave portion.

3. The method for producing an absorbent body according to claim 1 or 2, wherein: The compression forming portion is arranged in plurality at intervals in the cross direction, The plurality of compressed forming portions include a first compressed forming portion and a second compressed forming portion arranged beside the first compressed forming portion in the intersecting direction. A maximum difference between a feeding speed of the substrate in the first compression forming section and a feeding speed of the substrate in the second compression forming section is within 5%.

4. The method for producing an absorbent body according to claim 3, wherein: The lower roller of the pair of rollers having a placement surface on which the substrate can be placed has an end parallel surface, which is the placement surface parallel to the intersecting direction and places an end of the substrate in the intersecting direction. The maximum distance of the side compression forming portion of each of the plurality of compression forming portions in the vertical direction with reference to the end parallel surface is 5% or less of the radial distance from the rotation axis of the lower roller to the end parallel surface.

5. The method for producing an absorbent body according to claim 3, wherein: In the intersecting direction, the intervals between the plurality of compressed forming portions are equal to or greater than the height of the convex portion in the vertical direction.

6. The method for producing an absorbent body according to claim 3, wherein: The lower roller of the pair of rollers has a placement surface on which the substrate can be placed. A central area is provided which is located in the center when the placing surface is divided into five equal parts in the intersecting direction. In the compressing step, any one of the plurality of compression forming portions compresses the base material in the central region.

7. The method for producing an absorbent body according to claim 3, wherein: The lower roller of the pair of rollers has a placement surface on which the substrate can be placed. A central region located at the center when the placement surface is divided into five equal parts in the intersecting direction and side regions located on both sides of the central region in the intersecting direction are provided. In the compressing step, the plurality of compression forming portions compress the base material in the side regions instead of in the central region.

8. The method for producing an absorbent body according to claim 3, wherein: The one roller has the convex portion of the first compression forming portion and the concave portion of the second compression forming portion, The other roller has the concave portion of the first compression forming portion and the convex portion of the second compression forming portion.

9. The method for producing an absorbent body according to claim 3, wherein: In the lower roller of the pair of rollers having a placement surface on which the substrate can be placed, an intermediate surface placed between the first compression forming portion and the second compression forming portion and facing the substrate has an inclined placement surface inclined with respect to the intersecting direction.

10. The method for producing an absorbent body according to claim 1 or 2, wherein: Non-compression forming parts are provided on both sides of the compression forming part in the intersecting direction thereof for conveying the substrate without compression. In the lower roller of the pair of rollers having a placement surface on which the substrate can be placed, the non-compressed formed portion has a parallel protruding surface extending in parallel with the intersecting direction from an end portion of the compressed formed portion in the intersecting direction.

11. The method for producing an absorbent body according to claim 10, wherein: The compression forming portion is arranged in plurality at intervals in the cross direction, The plurality of compressed forming portions include a first compressed forming portion and a second compressed forming portion arranged beside the first compressed forming portion in the intersecting direction. The non-compressed forming portion is provided between the first compressed forming portion and the second compressed forming portion. In the lower roller, the non-compressed forming portion has an intermediate surface, and the intermediate surface is arranged between the first compressed forming portion and the second compressed forming portion and faces the substrate. In the lower roller, the intermediate surface has the parallel protruding surface and an axis-side parallel surface that is closer to the rotation axis of the lower roller than the parallel protruding surface and extends in the intersecting direction. An average distance in the perpendicular direction from the axis-side parallel surface to an upper roller of the pair of rollers is longer than an average distance in the perpendicular direction from the parallel extended surface to the upper roller.

12. The method for producing an absorbent body according to claim 1 or 2, wherein: A plurality of small protrusions protruding in the vertical direction are arranged at intervals on the top of the convex portion in the conveying direction. The small protrusion extends in the intersecting direction while being inclined relative to the conveying direction. The small protrusion overlaps with the small protrusion adjacent to the small protrusion in the intersecting direction.

13. The method for producing an absorbent body according to claim 1 or 2, wherein: The method for producing an absorbent body includes a cutting step of cutting the base material so as to divide the base material in the conveying direction after the compressing step.

14. The method for producing an absorbent body according to claim 1 or 2, wherein: The method for manufacturing an absorbent body comprises a cutting step of cutting the substrate so as to divide the substrate in the conveying direction. In the compression step, the compression grooves are formed in the cut base material.

15. The method for producing an absorbent body according to claim 1 or 2, wherein: The pair of rollers each has a plurality of roller portions divided in the intersecting direction, At least one of the compression forming parts is disposed on each of the plurality of roller parts. In the compression step, the rotation speed of each of the plurality of rollers is controlled so that a difference in the feeding speed of the substrate is within 5%.

16. The method for producing an absorbent body according to claim 15, wherein: There are gaps between the plurality of roller portions.

17. An apparatus for manufacturing an absorbent body having compressed grooves, wherein: The manufacturing device of the absorbent body comprises: a pair of rollers facing each other; and A compression forming portion, which is composed of convex portions and concave portions facing each other, compresses the base material of the absorbent body, The compression forming section forms the compression groove on the base material using the convex portion provided on one roller of the pair of rollers and the concave portion provided on the other roller. The compression forming portion includes a side compression forming portion, which is a portion of the side portion of the convex portion and the side portion of the concave portion that compresses the base material. while at least the side compression forming portion compresses the substrate and sends out the substrate in a conveying direction, A difference between a feeding speed of the substrate on one side and a feeding speed of the substrate on the other side of the side compression forming portion in the vertical direction is within 5%.

18. A method for manufacturing an absorbent article, the method comprising: providing an absorbent body having compressed grooves formed by compression forming portions composed of convex portions and concave portions facing each other; The manufacturing method of the absorbent article comprises a compressing step of forming the compressed grooves in the base material of the absorbent body by using the convex portion of one roller provided in a pair of rollers facing each other and the concave portion provided in the other roller, The compression forming portion includes a side compression forming portion, which is a portion of the side portion of the convex portion and the side portion of the concave portion that compresses the base material. In the compression step, the substrate is fed out in a conveying direction while being compressed by at least the side compression forming portion. A difference between a feeding speed of the substrate on one side and a feeding speed of the substrate on the other side of the side compression forming portion in the vertical direction is within 5%.

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