METHODS FOR MANUFACTURING ABSORBENT UNDERWEAR, AND EQUIPMENT FOR MANUFACTURING ABSORBENT UNDERWEAR

Abstract

The invention relates to a method for producing an absorbent garment in the form of underwear (1) comprising waistband sections (20, 30) and a fixing section (5), the method comprising: a transport step (S1) for transporting, in the direction of transport, a continuous detail around the waistband (20L) to form the waistband section (20); and a welding step (S6) for welding the base (5t) of the fixing section (5) to the continuous detail around the waistband (20L) to form the welded section (F1) as a cutting guide (40) in the continuous detail around the waistband (20L).

Description

Method for manufacturing pants-type absorbent articles and apparatus for manufacturing pants-type absorbent articles

[0001] The present invention relates to a method for manufacturing pants-type absorbent articles and an apparatus for manufacturing pants-type absorbent articles.

[0002] Conventionally, in a production line for manufacturing absorbent articles, etc., a method for joining materials together by performing a welding process such as ultrasonic welding on material sheets has been known. For example, Patent Document 1 discloses an ultrasonic processing device and method for continuously joining sanitary materials by pressing them with ultrasonic vibrations.

[0003] Chinese Patent No. 105710524

[0004] The ultrasonic processing method disclosed in Patent Document 1 extends the time that the ultrasonic welding unit acts on the material, thereby extending the time of the thermal compound action and achieving a good thermal compound effect. However, it does not particularly disclose any processing or method that makes it easier to cut the material based on the welding process portion.

[0005] For example, when manufacturing an absorbent article that is pants-type in its initial state, has fastening parts including engaging members on one or both sides of the article in the left-right direction, and can form leg openings by cutting a portion of the waistband and engaging the fastening parts with the waistband, there is a process of welding the fastening parts to a material that will become the waistband. This process fixes the fastening parts to the waistband, but in the case of the absorbent article, pulling the fastening parts cuts a portion of the waistband in the vertical direction to open it during use, so a design that makes it easy to tear (tear) is required. For example, if perforations or the like are added to make the absorbent article easier to tear, such a structure must be formed in a process separate from the welding process, and therefore an efficient method is needed.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a method for manufacturing a pants-type absorbent article that can efficiently form a cutting guide portion that guides the user to cut a member and can efficiently bond materials together.

[0007] The main invention for achieving the above object is a method for manufacturing a pants-type absorbent article having a waist portion and a fastening portion, the method comprising: a conveying step of conveying the continuous waist member for forming the waist portion in a conveying direction; and a welding step of welding a base end of the fastening portion to the continuous waist member to form a welded portion as a cutting guide portion in the continuous waist member. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0008] According to the present invention, it is possible to provide a method for manufacturing a pants-type absorbent article that can efficiently form a cutting guide portion that guides a user to cut a member and efficiently bond materials together.

[0009] 2 is a perspective view of the disposable diaper 1 in a worn state; FIG. 3 is a plan view of the disposable diaper 1 in an unfolded and stretched state, as seen from the non-skin side; FIG. 4 is an enlarged view of a portion X in FIG. 2; FIG. 5 is an enlarged view of a portion X in FIG. 2; FIG. 6 is a diagram illustrating separation and joining of the ventral waistline portion 20; FIG. 7 is a diagram illustrating the operation of cutting the ventral waistline portion 20; FIG. 8 is a diagram illustrating a partial cut portion 41; FIG. 9 is a schematic side view of a portion of a manufacturing line 100 for the pants-type disposable diaper 1 according to the present embodiment; FIG. 10 is a schematic diagram illustrating a manufacturing flow of the pants-type disposable diaper 1 according to the present embodiment; FIG. 11 is an enlarged view illustrating a temporary fastening portion 60 formed in the temporary fastening step S5; FIG. 12 is an enlarged view illustrating a welded portion F1 formed in the welding step S6; FIG. 13 is a diagram illustrating a modified example of the formation of the partial cut portion 41; FIG. 14 is an enlarged view illustrating a cut guide portion 40; FIG. 15 is a diagram illustrating the details of a portion of the welded portion F1, the auxiliary welded portion F2, and the auxiliary welded portion F3; FIG. 16 is a diagram illustrating a manufacturing method in which fastening portions 5 are provided on both left and right sides of the diaper 1.

[0010] At least the following points become clear from the description of this specification and the accompanying drawings: Aspect 1 is a method for manufacturing a pants-type absorbent article having a waist portion and a fastening portion, the method comprising: a conveying step of conveying the continuous waist member for forming the waist portion in a conveying direction; and a welding step of welding a base end of the fastening portion to the continuous waist member to form a welded portion as a cutting guide portion in the continuous waist member.

[0011] According to the manufacturing method of the pants-type absorbent article of aspect 1, the cutting guide portion is a portion that guides the user to cut the waist portion when using the product, and the bonding of the fastening portion and the formation of such a cutting guide portion can be efficiently carried out in a single process (welding process) for forming the welded portion.

[0012] Aspect 2 is the method for manufacturing a pants-type absorbent article according to Aspect 1, wherein the welded portion is formed to form a partially cut portion in which a part of the continuous waistband member is cut.

[0013] According to the method for manufacturing a pants-type absorbent article of Aspect 2, the partial cut portion is a slit that makes it easier to cut the waist portion at the cut guide portion. The partial cut portion is not only efficiently formed in a single process for forming welded portions (welding process) together with the bonding of the fastening portions, but also in a case where it is formed in the welded portion by tension (tension) applied to the continuous waist member during transportation after the welded portions have been formed. Furthermore, due to the cross-sectional configuration, if the partial cut portion is formed separately, it must be formed before the bonding of the fastening portions. In such a case, there is a risk that the waist portion will break at the partial cut portion before the bonding of the fastening portions. However, by welding the base end of the fastening portion to the continuous waist member, a welded portion as a cut guide portion is simultaneously formed in the continuous waist member, thereby eliminating the above-mentioned concerns.

[0014] Aspect 3 is a method for manufacturing a pants-type absorbent article described in Aspect 1 or 2, in which, when the direction intersecting the conveying direction is the CD direction, the welded portion is formed to form the cutting guide portion from one end of the waist continuous member in the CD direction to the other end.

[0015] According to the method for manufacturing a pants-type absorbent article of Aspect 3, the risk of impeding the transport state is reduced by forming a cutting guide portion along the CD direction. The cutting guide portion is a portion that guides the waistband portion to be cut in the up-and-down direction (CD direction during transport) from its upper end to its lower end when the product is in use, and by forming the cutting guide portion from one end to the other end in the CD direction, it is possible to more easily promote the cutting of the waistband portion when the product is in use.

[0016] Aspect 4 is a method for manufacturing a pants-type absorbent article according to any one of Aspects 1 to 3, wherein, when a direction intersecting the conveying direction is defined as a CD direction, the cutting guide portion has a one-side inclined portion inclined from the center in the CD direction toward one side and the base end side of the fastening portion, and an other-side inclined portion inclined from the center toward the other side and the base end side of the fastening portion, and when a portion of the fastening portion located on the opposite side of the conveying direction from the base end is defined as a tip portion, the intersection of the one-side inclined portion and the other-side inclined portion is located closer to the tip portion in the conveying direction than the outer end in the CD direction of the one-side inclined portion and the outer end in the CD direction of the other-side inclined portion.

[0017] According to the manufacturing method of pants-type absorbent articles of aspect 4, the fastening portion is a part that is grasped at its tip and pulled in the left-right direction (the conveying direction during manufacturing) when cutting the waist portion during use of the product, and by forming the inclination of the cutting guide portion in the above-mentioned shape, the pulling force is likely to first concentrate at the above-mentioned intersection of the cutting guide portion, and the force is then propagated along the inclined portion, making it easier to cut along the cutting guide portion.

[0018] Aspect 5 is a method for manufacturing a pants-type absorbent article described in any one of Aspects 2 to 4, characterized in that, when the direction intersecting the conveying direction is the CD direction, by forming the welded portion, the partially cut portion having a predetermined length in the CD direction of the waistline continuous member is formed along the cutting guide portion.

[0019] According to the manufacturing method of pants-type absorbent articles of aspect 5, the cutting guide portion of the pants-type absorbent article is a portion that guides the waist portion to be cut in the vertical direction from its upper end to its lower end during use, and by forming a partial cut portion having a predetermined length in the CD direction (vertical direction of the product) of the waist continuous member along the cutting guide portion, the partial cut portion can be formed without interfering with the conveying state.

[0020] Aspect 6 is a method for manufacturing pants-type absorbent articles according to any one of Aspects 1 to 5, which includes a spacing change step of changing the attachment spacing of the fastening parts to a spacing appropriate for the product size prior to the welding step.

[0021] According to the manufacturing method of pants-type absorbent articles of aspect 6, the spacing can be changed according to the size of the product to be manufactured by changing the settings of the spacing change process, so there is no need to replace the entire spacing change device.

[0022] Aspect 7 is a manufacturing method for a pants-type absorbent article according to Aspect 6, which includes a temporary fastening step of forming a temporary fastening portion that temporarily fastens the fastening portion to the waist continuous member after the spacing change step and before the welding step.

[0023] According to the manufacturing method of pants-type absorbent articles of aspect 7, by temporarily fastening the fastening parts before the welding process, it is possible to prevent the fastening parts from shifting or coming off during transportation until the welding process is performed, and also improve the stability of the subsequent welding process.

[0024] Aspect 8 is a manufacturing method of a pants-type absorbent article described in Aspect 7, in which, in the temporary fastening process, the temporary fastening portion is not formed at the tip end portion of the fastening portion that is located on the opposite side of the conveying direction from the base end portion.

[0025] According to the manufacturing method of the pants-type absorbent article of aspect 8, the tip of the fastening part is the part that is used to grab with the fingers and peel off when using the product, and by not forming a temporary fastening part at that position, it becomes easier for the user to grab the fastening part and peel it off from the waist part.

[0026] Aspect 9 is a method for manufacturing a pants-type absorbent article according to Aspect 7 or 8, wherein, when the upstream side of the fastening portion in the conveying direction is defined as the upstream side and the downstream side of the fastening portion in the conveying direction is defined as the downstream side, based on the cutting guide portion, the total area of ​​the temporary fastening portions provided per unit area of ​​the downstream side of the fastening portion is larger than the total area of ​​the temporary fastening portions provided per unit area of ​​the upstream side of the fastening portion.

[0027] According to the manufacturing method of pants-type absorbent articles of Aspect 9, the downstream side of the temporarily fastened fastening parts is a part that is prone to curling up or shifting during transport. By forming many temporary fastening parts in such a downstream side part, it is possible to prevent curling up or the like, and the welding step can be carried out more stably.

[0028] Aspect 10 is a method for manufacturing a pants-type absorbent article according to any one of Aspects 1 to 9, wherein the waist portion has a first sheet, a second sheet, and a waist elastic member provided between the first sheet and the second sheet, the waist continuous member has a first sheet material to which the first sheet is continuous in the conveying direction, a second sheet material to which the second sheet is continuous in the conveying direction, and a waist elastic continuous member to which the waist elastic member is continuous in the conveying direction, the waist elastic continuous member being joined in a stretched state between the first sheet material and the second sheet material, and in the welding process, the waist elastic continuous member is cut by forming the welded portion.

[0029] According to the manufacturing method of the pants-type absorbent article of Aspect 10, by cutting the waist elastic continuous member (waist elastic member), the waist elastic member becomes discontinuous in the region where the fastening parts are present, and does not exhibit stretchability. By eliminating stretch in the region where the fastening parts are present, wrinkles and the like are less likely to occur in the fastening parts, and usability of the product can be improved.

[0030] Aspect 11 is a method for manufacturing a pants-type absorbent article described in any of Aspects 1 to 10, in which, when the direction intersecting the conveying direction is the CD direction, in the welding process, the welded portion is formed so that the outer end of the welded portion in the CD direction does not become a continuous line.

[0031] According to the method for manufacturing pants-type absorbent articles of Aspect 11, the welded parts are not continuous lines, so that so-called non-welded parts are provided, and the non-welded parts are in a state where a part of the continuous waistline member is connected without being welded. By forming welded parts (cut guide parts) and providing non-welded parts where a part of the continuous waistline member is connected together with the cut guide parts, the continuous waistline member is not cut all the way to the end, so that it is possible to prevent the flow of the production line from being interrupted.

[0032] Aspect 12 is a method for manufacturing a pants-type absorbent article according to Aspect 11, wherein the fastening portion has an engaging portion that detachably engages with the non-skin side of the waist portion, and when a portion where the welded portion does not form a continuous line is defined as a discontinuous portion, the discontinuous portion is provided at a position that does not overlap with the engaging portion in the CD direction.

[0033] According to the method for manufacturing a pants-type absorbent article of Aspect 12, when the tear guide portion is formed, the engaging portion is in a state of being detachably engaged with the continuous waist member. Therefore, in the region where the engaging portion is present, the engagement between the continuous waist member and the engaging portion can prevent the tear from spreading from the partial cut portion. Furthermore, by forming a discontinuous portion at a position that does not overlap with the engaging portion, it becomes easier to prevent the tear from spreading from the partial cut portion even in the region where the engaging portion is not present.

[0034] Aspect 13 is a method for manufacturing a pants-type absorbent article described in any one of Aspects 2 to 12, wherein the fastening portion has an engaging portion that detachably engages with the non-skin side of the waist portion, and when the direction intersecting the conveying direction is the CD direction, in the welding process, at least a portion of the partial cut portion is formed so as to overlap with the engaging portion in the CD direction.

[0035] According to the method for manufacturing pants-type absorbent articles of Aspect 13, the partially cut portions are positioned on an extension of the engaging portions in the conveyance direction (left-right direction of the product), and opening of the partially cut portions in the conveyance direction can be suppressed.

[0036] Aspect 14 is a method for manufacturing a pants-type absorbent article described in any one of Aspects 2 to 12, wherein the fastening portion has an engaging portion that detachably engages with the non-skin side of the waist portion, and when the direction intersecting the conveying direction is the CD direction, in the welding process, the partial cut portion is formed so as not to overlap with the engaging portion in the CD direction.

[0037] According to the manufacturing method of pants-type absorbent articles of aspect 14, by providing a partial cut portion at a location that does not overlap with the engagement portion, the impact on the continuous waistband member is reduced, and the risk of the cut in the continuous waistband member spreading during transportation is reduced.

[0038] Aspect 15 is a method for manufacturing a pants-type absorbent article according to any one of Aspects 2 to 14, wherein, when the direction intersecting the conveying direction is the CD direction, the cutting guide portion has a one-side inclined portion that inclines from the center in the CD direction toward one side and the base end side of the fastening portion, and an other-side inclined portion that inclines from the center toward the other side and the base end side of the fastening portion, and the partial cut portion is located across the intersection of the one-side inclined portion and the other-side inclined portion.

[0039] According to the manufacturing method of pants-type absorbent articles of aspect 15, by providing a partial cut portion across the intersection of the one-side inclined portion and the other-side inclined portion, it is possible to prevent the partial cut portion from expanding during transportation.

[0040] Aspect 16 is a method for manufacturing a pants-type absorbent article described in any one of Aspects 7 to 9, in which by forming the welded portion, a partial cut portion is formed in which a portion of the waistline continuous member is cut, and when the direction intersecting the conveying direction is the CD direction, at least a portion of the partial cut portion overlaps with the temporary fastening portion in the CD direction.

[0041] According to the method for manufacturing pants-type absorbent articles of aspect 16, the temporary fastening parts strengthen the fixation of the fastening parts to the continuous waistband member, and the stretching of the continuous waistband member in the conveyance direction (the left-right direction of the product) is further suppressed. Therefore, it is possible to suppress the opening of the partially cut parts in the conveyance direction and to suppress unnecessary cutting of the continuous waistband member starting from the partially cut parts.

[0042] Aspect 17 is a method for manufacturing a pants-type absorbent article as described in Aspect 12, in which, in the welding process, when forming the welded portion, an auxiliary welded portion separate from the welded portion is formed by welding the base end of the fastening portion to the waist continuous member, and the auxiliary welded portion is adjacent to the cutting guide portion from the base end side of the fastening portion in the conveying direction, and at least a portion of the discontinuous portion overlaps with the auxiliary welded portion in the CD direction.

[0043] According to the manufacturing method of pants-type absorbent articles of aspect 17, by forming auxiliary welded portions, the tensile strength concentrated in the discontinuous areas can be alleviated by the auxiliary welded portions, thereby preventing breakage in the conveying direction.

[0044] Aspect 18 is a manufacturing apparatus for pants-type absorbent articles having a waist portion and a fastening portion, characterized in that it comprises a conveying section that conveys the waist continuous member for forming the waist portion in a conveying direction, and a welding forming section that welds the base end of the fastening portion to the waist continuous member to form a welded portion as a cutting guide portion on the waist continuous member.

[0045] According to the manufacturing device for pants-type absorbent articles of Aspect 18, the cutting guide portion is a portion that guides the user to cut the waist portion when using the product. In this manufacturing device, the bonding of the fastening portion and the formation of such a cutting guide portion can be efficiently performed in a single welding and forming unit that forms the welding portion.

[0046] ===Embodiment=== The manufacturing method and manufacturing device for a pants-type absorbent article 1 of this embodiment are used in a manufacturing line 100 for pants-type disposable diapers 1 for infants, which are one example of pants-type absorbent articles 1. However, pants-type absorbent articles according to the present invention are not limited to pants-type disposable diapers for infants, and can also be used, for example, as disposable diapers for adults, sanitary shorts, etc.

[0047] <Basic Structure of Disposable Diaper 1> Fig. 1 is a perspective view of a disposable diaper 1 (hereinafter referred to as "diaper") in a worn state, as viewed from one side in the left-right direction. Fig. 2 is a plan view of the diaper 1 in an unfolded and stretched state, as viewed from the non-skin side. The center line C-C in Fig. 2 is the center line in the left-right direction in the stretched state. Figs. 3 and 4 are enlarged views of a portion X in Fig. 2.

[0048] The "unfolded state" refers to a state in which both sides of the diaper 1 in a pants-type state, i.e., the side joints 2a, 2b at both side ends of the ventral waistband 20 and the back waistband 30, which will be described later, are separated and opened, thereby unfolding the entire diaper 1 in a flat plane. The "stretched state" refers to a state in which the elastic members of the diaper 1 are stretched to an extent that wrinkles in the diaper 1 are no longer visible. Specifically, this refers to a state in which the dimensions of each component constituting the diaper 1 (e.g., the ventral waistband 20, which will be described later, etc.) are stretched to the extent that they match or are close to the dimensions of the component alone.

[0049] In the pants-type state shown in Fig. 1, the diaper 1 has a vertical direction, a horizontal direction, and a front-to-back direction that intersect (are perpendicular to) one another, and is provided with a waist opening BH and a pair of leg openings LH, LH. In the vertical direction, the waist opening BH side is the upper side, and the crotch side is the lower side. In the front-to-back direction, the wearer's abdominal side is the front side, and the wearer's back side is the rear side. The direction in which the materials constituting the diaper 1 are layered is referred to as the thickness direction, and the side in contact with the wearer in the thickness direction is referred to as the skin side, and the side opposite the skin side is referred to as the non-skin side. The thickness direction also corresponds to the front-to-back direction of the diaper 1 in the pants-type state.

[0050] The diaper 1 is a so-called three-piece type, and includes an annular waist portion having a ventral waist portion 20 and a dorsal waist portion 30, and an absorbent main body 10. The ventral waist portion 20 covers the wearer's ventral side, and the dorsal waist portion 30 covers the wearer's dorsal side. The diaper 1 also includes fastening parts 5.

[0051] In the diaper 1 in the unfolded state shown in Fig. 2, the ventral waist portion 20 and the back waist portion 30 are arranged so that their longitudinal directions are aligned with the left-right direction of the diaper 1. One longitudinal end of the absorbent main body 10 is arranged in the center of the ventral waist portion 20 in the left-right direction, and the other longitudinal end of the absorbent main body 10 is arranged in the center of the back waist portion 30 in the left-right direction, thereby forming a crotch portion 80. The absorbent main body 10 is arranged closer to the skin than the ventral waist portion 20 and the back waist portion 30.

[0052] The diaper 1 in the unfolded state shown in Fig. 2 is folded in half at approximately the center CL of the absorbent body 10 in the longitudinal direction, with the longitudinal direction of the absorbent body 10 aligned with the up-down direction of the diaper 1, and both side ends of the ventral waistband portion 20 and both side ends of the dorsal waistband portion 30 in the left-right direction of the diaper 1 are joined by heat welding, ultrasonic welding, or the like to form a pair of side joints 2a, 2b, thereby producing the pants-type diaper 1 shown in Fig. 1. The side joint 2a is a joint provided on one side in the left-right direction, and the side joint 2b is a joint provided on the other side in the left-right direction.

[0053] The absorbent body 10 comprises an absorbent body 11, a liquid-permeable top sheet 12 arranged closer to the skin than the absorbent body 11, a second sheet 13 arranged between the top sheet 12 and the absorbent body 11, a side sheet 14 arranged closer to the skin than the absorbent body 11 and the second sheet 13, a liquid-impermeable back sheet 15 arranged closer to the skin than the absorbent body 11, and an outer sheet 16 arranged closer to the skin than the back sheet 15.

[0054] The absorbent body 11 has a generally rectangular shape in plan view and includes an absorbent core 11A that absorbs and retains excretions such as urine, and a liquid-permeable core wrap sheet (not shown) that covers the absorbent core. Examples of the absorbent core 11A include a liquid-absorbent fiber such as pulp containing superabsorbent polymer (SAP) molded into a predetermined shape, such as a generally hourglass shape in plan view (a liquid-absorbent fiber molded product), and a so-called SAP sheet in which superabsorbent polymer (SAP) is molded into a sheet. Examples of the core wrap sheet include a liquid-permeable sheet such as tissue paper or nonwoven fabric, but a configuration without a core wrap sheet is also possible.

[0055] As shown in Fig. 2, leg elastic members 17 provided on both lateral sides of the absorbent main body 10 constitute leg gathers. The leg gathers of the pants-type diaper 1 are provided along the leg openings LH, and the diaper 1 fits around the legs of the wearer by the elasticity of the leg elastic members 17. The leg elastic members 17 of the diaper 1 are made of a plurality of rubber threads, and are fixed in a stretched state in the longitudinal direction of the absorbent main body 10 between the back sheet 15 and the outer sheet 16, for example, between the outer sheets 16 that are folded inward in the lateral direction to form two layers.

[0056] The absorbent body 10 has leak-preventing wall elastic members 18 on both left-right sides thereof, inside the leg-hole elastic members 17. A plurality of leak-preventing wall elastic members 18 are fixed in a longitudinally stretched state between the two layers of side sheets 14 folded outward in the left-right direction, forming a pair of leak-preventing wall portions along the longitudinal direction. When the diaper 1 is worn, the leak-preventing wall portions rise up against the wearer's skin due to the elasticity exhibited by the leak-preventing wall elastic members 18, and fit snugly against the wearer's crotch area.

[0057] Examples of the leg-hole elastic members 17 and the leak-preventing wall elastic members 18 include rubber threads and elastic sheets.

[0058] The ventral waistline portion 20 has a skin-side sheet 21, a non-skin-side sheet 22 disposed on the non-skin side of the skin-side sheet 21, and multiple waistline stretch members 23 that stretch in the left-right direction. The skin-side sheet 21 and the non-skin-side sheet 22 are sheet members of approximately the same size and shape, and in this embodiment, are approximately rectangular. The skin-side sheet 21 and the non-skin-side sheet 22 can be made of non-stretch sheets such as SMS nonwoven fabric (spunbond, meltblown, spunbond nonwoven fabric), spunbond nonwoven fabric, air-through nonwoven fabric, point-bond nonwoven fabric, stretch nonwoven fabric, plastic sheet, perforated plastic sheet, or laminate sheets thereof.

[0059] The multiple waistline elastic members 23 of the ventral waistline portion 20 are arranged vertically between the skin-side sheet 21 and the non-skin-side sheet 22 and are fixed in a stretched state in the left-right direction. Therefore, the ventral waistline portion 20 stretches left-right to fit the wearer's waist. Examples of the waistline elastic members 23 include elastic members such as rubber and spandex. The ventral waistline portion 20 has an engaged portion 25 on the non-skin-side surface of the non-skin-side sheet 22 that can engage with an engaging portion 51 (described below) of the fastening portion 5. The engaged portion 25 is a so-called target area, and examples thereof include a nonwoven fabric sheet. Furthermore, if a male hook-and-loop fastener is used for the engaging portion 51, it is desirable to select an engaged portion that corresponds to the engaging portion 51, such as a female hook-and-loop fastener, for the engaged portion 25. Furthermore, instead of providing a separate member on the non-skin side of the non-skin side sheet 22, the non-skin side sheet 22 may be made of a member (e.g., nonwoven fabric) that can engage with the engaging portion 51, and the engaging portion 25 may be directly engaged with the non-skin side of the non-skin side sheet 22. However, conversely to the above, the engaging portion 25 of the ventral waistline portion 20 may be a male member of a hook-and-loop fastener, and the engaging portion 51 of the fastening portion 5 (the surface facing the ventral waistline portion 20) may be a nonwoven fabric sheet, a female member of a hook-and-loop fastener, or the like.

[0060] The back waistband portion 30 includes a skin-side sheet 31, a non-skin-side sheet 32 ​​disposed closer to the skin than the skin-side sheet 31, and multiple waistband stretch members 33 that stretch in the left-right direction. The skin-side sheet 31 and the non-skin-side sheet 32 ​​are laminated and joined together by a joining method such as an adhesive such as hot melt, or by heat or ultrasonic welding. The skin-side sheet 31 and the non-skin-side sheet 32 ​​are sheet members of approximately the same size and shape, and in this embodiment, are approximately rectangular. The skin-side sheet 31 and the non-skin-side sheet 32 ​​can be, for example, a non-stretch sheet such as a polypropylene SMS nonwoven fabric (spunbond, meltblown, or spunbond nonwoven fabric), a spunbond nonwoven fabric, an air-through nonwoven fabric, a point-bond nonwoven fabric, a stretch nonwoven fabric, a plastic sheet, a perforated plastic sheet, or a laminate sheet thereof.

[0061] The multiple waistline elastic members 33 of the back-side waistline portion 30 are arranged side by side in the vertical direction between the skin-side sheet 31 and the non-skin-side sheet 32, and are fixed in a stretched state in the left-right direction. Therefore, the ventral waistline portion 20 and the back-side waistline portion 30 each stretch in the left-right direction to fit the waist of the wearer. Examples of the waistline elastic members 33 include elastic members such as rubber and spandex.

[0062] The fastening part 5 is a so-called tab (knob) member, and is a member used to reconnect the ventral waistline portion 20 when the ventral waistline portion 20 is cut by engaging the engaging part 51. In the fastening part 5 of this embodiment, the base end of the fastening part 5 (one side in the left-right direction in FIG. 2 etc.) is fixed to one side of the center in the left-right direction of the ventral waistline portion 20, and the tip end of the fastening part 5 (the other side in the left-right direction in FIG. 2 etc.) has the engaging part 51 that separably engages with the non-skin side of the ventral waistline portion 20.

[0063] The fastening part 5 is a member that is grasped and operated by the wearer or a person putting the diaper 1 on the wearer (hereinafter also referred to as the "wearer, etc."), and therefore, it is preferable that the fastening part 5 itself has a strength sufficient to prevent breakage. As the fastening part 5, for example, various films such as plastic film and nylon film, nonwoven fabric, film laminated with nonwoven fabric, etc. can be used.

[0064] The engaging portion 51 is provided on the skin side of the fastening portion 5 and is a member that can detachably engage with the non-skin side of the ventral waistline portion 20 (specifically, the engaged portion 25). Examples of the engaging portion 51 include a male member of a hook-and-loop fastener and an adhesive material such as an adhesive sheet. The engaging portion 51 in this embodiment has a substantially rectangular shape, but may have any other shape, such as a round shape.

[0065] As shown in Fig. 3 etc., the base end of the fastening part 5 is fixed to the ventral waistline part 20 by a welding part F1, an auxiliary welding part F2, and an auxiliary welding part F3. In this embodiment, the welding part F1 and the auxiliary welding parts F2 and F3 are parts where the fastening part 5 and the ventral waistline part 20 are joined in the thickness direction by heat welding, ultrasonic welding, or the like. The fastening part 5 is fixed to the ventral waistline part 20 mainly by the welding part F1, and the auxiliary welding parts F2 and F3 assist the fixation by the welding part F1.

[0066] ===Cutting of the ventral waistline portion 20=== Cutting of the ventral waistline portion 20 will be described with reference to Figures 5 and 6. Figure 5 is a diagram illustrating the separation and joining of the ventral waistline portion 20. Figure 6 is a diagram illustrating the operation of cutting the ventral waistline portion 20. Figure 5 is a diagram illustrating the cross-sectional configuration taken along line A-A in Figure 3. Note that Figures 5 and 6 are schematic diagrams, and the dimensions etc. are not necessarily accurate.

[0067] The diaper 1 is distributed with the ventral waist portion 20 and the dorsal waist portion 30 joined at the side seams 2a, 2b. After removing the diaper 1 from the package, a user (e.g., a parent) cuts open a portion of the annular waist portions 20, 30 (here, one lateral portion of the ventral waist portion 20) in the vertical direction. The user then places one leg of the wearer (e.g., a child) (the wearer's right leg in the case of the diaper 1) through the leg opening LH on the other lateral side and pulls the diaper 1 up to the wearer's crotch. The user then engages the engaging portion 51 of the fastening part 5 with the ventral waist portion 20 to fit the diaper 1 around the wearer's waist, thereby joining the ventral waist portion 20 together, thereby putting the diaper 1 on.

[0068] In this way, one side of diaper 1 in the left-right direction is in the form of a tape-type diaper (without leg openings LH formed), and the other side in the left-right direction can be worn in the form of a so-called pants-type diaper (with leg openings LH formed).

[0069] To this end, the diaper 1 has a "cutting guide portion 40" that guides the user to cut the waist-circumference portions 20, 30 in the vertical direction. Specifically, the cutting guide portion 40 is a portion that guides the user to cut the waist-circumference portions 20, 30 in the vertical direction from their upper ends (the ends facing the waist-circumference openings BH) to their lower ends (the ends facing the leg-circumference openings LH). The cutting guide portion 40 also makes it easier to cut the waist-circumference portions 20, 30. In other words, the user can cut the waist-circumference portions 20, 30 at the cutting guide portion 40 with less force than when cutting the waist-circumference portions 20, 30 at the non-cutting guide portion.

[0070] In the diaper 1 of this embodiment, the welded portion F1 that fixes the ventral waist portion 20 and the fastening portion 5 functions as the cutting guide portion 40. The welded portion F1 joins the fastening portion 5 and the ventral waist portion 20 in the thickness direction by heat welding, ultrasonic welding, or the like.

[0071] Auxiliary welds F2 and F3 are provided closer to the base end of the fastening part 5 in the left-right direction than the weld F1. The auxiliary welds F2 and F3 also join the fastening part 5 and the abdominal-side waistline part 20 in the thickness direction by heat welding, ultrasonic welding, or the like.

[0072] 5A is a cross-sectional view of the diaper 1 in the pants-type state shown in Fig. 1 etc. In other words, the ventral waist portion 20 is not cut, and the ventral waist portion 20 and the back waist portion 30 form a continuous waist opening BH via the side joining portions 2a, 2b. Figs. 5B and 6A show a state in which the tip of the fastening portion 5 is grasped and pulled up toward the non-skin side from the state shown in Fig. 5A.

[0073] 6A , by grasping the ventral waistline portion 20 with one hand and the fastening portion 5 with the other hand and pulling them outward in the left-right direction, the ventral waistline portion 20 is cut along the cutting guide portion 40 as shown in FIGS. 5C and 6B . That is, the ventral waistline portion 20 is separated into one portion having the fastening portion 5 and the other portion not having the fastening portion 5. At the welded portion F1, some of the fibers of the skin-side sheet 21 and the non-skin-side sheet 22 constituting the ventral waistline portion 20 are melted and integrated during welding. Therefore, the rigidity of the ventral waistline portion 20 at the welded portion F1 is higher than the rigidity of the portion of the ventral waistline portion 20 adjacent to the welded portion F1. Therefore, when a user holds the ventral waistline portion 20 and the fastening portion 5 and pulls them left-right, the ventral waistline portion 20 on the side with a lower basis weight than the fastening portion 5 is torn and cut at the boundary portion with different rigidities. That is, the abdominal-side waistline portion 20 is cut along the other end CE of the welded portion F1 in the left-right direction (at the boundary between the welded portion F1 and the non-welded portion).

[0074] 5D , the engaging portion 51 of the fastening part 5 is engaged with the engaged portion 25 of the ventral waist portion 20, thereby reconnecting the ventral waist portion 20. Furthermore, by adjusting the position at which the engaging portion 51 is engaged with the engaged portion 25, the size of the waist opening of the diaper 1 can be adjusted.

[0075] Fig. 7 is a diagram illustrating the partially cut portion 41. Fig. 7A is a diagram illustrating the cross-sectional configuration along line B-B in Fig. 3. Fig. 7B is a diagram illustrating the fastening portion 5 in an open state.

[0076] The diaper 1 has a "partially cut portion 41" formed by cutting a portion of the waist portion 20, 30 (here, the ventral waist portion 20) in the up-down direction at the cutting guide portion 40. In other words, the portion of the waist portion 20, 30 that the user cuts along the cutting guide portion 40 is pre-cut. In the diaper 1 of this embodiment, a portion of the ventral waist portion 20 adjacent to the welded portion F1 from the other left-right side is pre-cut as the partially cut portion 41. As shown in Fig. 7A , only the ventral waist portion 20 is cut at the partially cut portion 41, and the fastening portion 5 is not cut. Note that Figs. 3 and 4 show the partially cut portion 41 virtually from the non-skin-facing side of the fastening portion 5.

[0077] For example, as shown in Figure 3, if a partial cut portion 41 is provided in the vertical center of the cutting guide portion 40, when the user rolls up the fastening portion 5, the partial cut portion 41 will be visible as a through hole, as shown in Figures 6A and 7B.

[0078] By visually checking the partial cut portions 41, the user can easily recognize that the waist portions 20, 30 need to be cut before putting on the diaper, and can also easily recognize the positions at which the waist portions 20, 30 should be cut. This prevents the waist portions 20, 30 from being put on in a ring-like state without being cut. It also prevents the waist portions 20, 30 from being cut at a position away from the fastening portion 5, for example, rather than at the cutting guide portions 40, which would result in a shortened adjustment range for the waist portions 20, 30. In other words, the partial cut portions 41 make it easier for the waist portions 20, 30 to be cut at the cutting guide portions 40, making it easier for the user to put on the diaper 1 properly.

[0079] Before use, in the diaper 1, the fastening part 5 is fixed to the ventral waist portion 20 by the engaging part 51 on the other left-right side of the cutting guide part 40, and the fastening part 5 is fixed to the ventral waist portion 20 by the welding part F1 on one left-right side of the cutting guide part 40 or on the cutting guide part 40. Even when the waist portions 20, 30 are stretched left-right when the user handles the diaper 1, the fastening part 5 prevents the ventral waist portion 20 from stretching left-right.

[0080] 4, the diaper 1 has a joining portion 60 (a temporary fastening portion, which will be described later) joining the fastening portion 5 and the waist portion 20, 30 on the base end side (one side) of the fastening portion 5 relative to the tear guide portion 40 in the left-right direction. The joining portion 60 strengthens the fixation of the fastening portion 5 to the abdominal waist portion 20, and the fastening portion 5 prevents the abdominal waist portion 20 from stretching in the left-right direction.

[0081] <Regarding the manufacturing method of the disposable diaper 1> Fig. 8 is a schematic side view of a part of a manufacturing line 100 for the pants-type disposable diaper 1 according to this embodiment. Fig. 9 is a schematic view showing the manufacturing flow of the pants-type disposable diaper 1 according to this embodiment. The manufacturing line 100 for the diaper 1 has a conveyance direction and a CD direction intersecting the conveyance direction. In Figs. 8 and 9, in order to easily explain the present invention, it is assumed that the absorbent main body 10 is supplied in a completed form, and the manufacturing equipment for the absorbent main body 10 itself is omitted (hereinafter, explanation of the manufacturing method of the absorbent main body 10 will also be omitted). Also, in Figure 8, the waistline portions (ventral waistline portion 20 and dorsal waistline portion 30) are supplied in the form of a continuous waistline member 20L (30L) in the left-right direction (conveying direction) in which a skin-side sheet 21 (31), a non-skin-side sheet 22 (32), and a plurality of waistline stretch members 23 (33) that stretch in the left-right direction are joined together.

[0082] The manufacturing method of the disposable diaper 1 includes a conveying step S1 of conveying the waistline continuous members 20L, 30L in the conveying direction, a step S2 of attaching the absorbent body 10 to the waistline continuous members 20L, 30L, a fastening portion forming step S3, a fastening portion spacing changing step S4, a fastening portion temporary fastening step S5, a welding step S6 of forming a welded portion in the waistline continuous member 20L, a folding step S7, a side joint forming step S8, and a cutting step S9.

[0083] In the conveying step S1, the waistline continuous members 20L and 30L are conveyed in the conveying direction as shown in Fig. 9. The waistline continuous member 20L is a continuous member in which the skin-side sheet 21 (first sheet) of the ventral waistline portion 20 is continuous in the conveying direction as a skin-side continuous sheet 21a (first sheet material), and the non-skin-side sheet 22 (second sheet) is continuous in the conveying direction as a non-skin-side continuous sheet 22a (second sheet material), which are overlapped in the thickness direction, and in which the waistline elastic members 23 are continuous in the conveying direction as a plurality of waistline elastic continuous members 23a, each of which has a waistline elastic member 23 continuous in the conveying direction, are joined in a stretched state lined up in the CD direction between these two continuous sheets 21a, 22a. Similarly, the waist continuous member 30L is a continuous member in which the skin side sheet 31a, in which the skin side sheet 31 relating to the waist portion 30 is continuous in the conveying direction, and the non-skin side continuous sheet 32a, in which the non-skin side sheet 32 ​​is continuous in the conveying direction, are stacked in the thickness direction, and between these two continuous sheets 31a, 32a, multiple waist elastic continuous members 33a, in which the waist elastic members 33 are continuous in the conveying direction, are lined up in the CD direction and joined in a stretched state.

[0084] The continuous waist members 20L, 30L are transported in the transport step S1 by an appropriate transport device (transport unit, not shown) such as a belt conveyor or transport rollers. Therefore, unless otherwise specified, it is assumed that the continuous waist members 20L, 30L are transported in the transport direction by these transport devices. Examples of belt conveyors include a normal belt conveyor having a driven, rotating endless belt as a transport surface, and a suction belt conveyor having a suction function on the outer peripheral surface of the endless belt.

[0085] In step S2 of attaching the absorbent main body 10 to the continuous waistline members 20L, 30L, a single-sheet absorbent main body 10 produced in a separate step (not shown) is suspended and fixed between the continuous waistline member 20L relating to the ventral waistline portion 20 and the continuous waistline member 30L relating to the dorsal waistline portion 30 ( FIG. 9 ). As a result, a substantially ladder-shaped continuous body 1hs of diapers is formed, which is made up of a series of diapers 1h, 1h... each expanded into a substantially H-shape.

[0086] As shown in Fig. 8 , the fastening portion forming step S3 is performed as a separate step before attaching the single-sheet fastening portions 5 to the continuous waistband member 20L. In this step S3, a fastening portion base sheet 5K for forming the fastening portions 5 is cut into the shape of the fastening portions 5 to form the single-sheet fastening portions 5. Note that male components of hook-and-loop fasteners that become the engaging portions 51, adhesive materials such as adhesive sheets, etc. are attached to the fastening portion base sheet 5K in advance at product pitch. As an example, the fastening portion base sheet 5K is cut using a die cutter device 105. The single-sheet fastening portions 5 are delivered one by one to a re-pitching device 106 at a processing position PK1 shown in Fig. 8 .

[0087] In the fastening portion spacing change step S4 (spacing change step), when the fastening portions 5 are transferred to the subsequent heat-sealing device 110 using the re-pitching device 106, the timing of the transfer is changed to an attachment spacing appropriate for the product size. That is, after each fastening portion 5 is formed in the fastening portion forming step S3, the formed fastening portions 5 are spaced apart to the desired spacing in step S4. The re-pitching device 106 can be, for example, a known re-pitching drum. Specifically, as shown in FIG. 8 , the re-pitching device 106 has holding pads 106P at multiple positions in the rotational direction on its outer periphery that suction-hold the fastening portions 5. After receiving the fastening portions 5 at processing position PK1, the holding pads 106P accelerate while rotating to change the attachment spacing to the desired spacing. Then, at processing position PK2, the fastening portions 5 are transferred to the heat-sealing device 110. In this way, by changing the settings of the interval changing process, the interval at which the fastening parts 5 are delivered can be changed according to the size of the product to be manufactured, so there is no need to replace the entire interval changing device.

[0088] The fastening portions 5 delivered to the heat-sealing device 110 are joined with the continuous waistband member 20L (continuous diaper body 1hs) at the processing position PK3, where the fastening portion temporarily fastening step S5 is carried out (FIGS. 8 and 9). The fastening portion temporarily fastening step S5 will be described in detail later. Note that, in the continuous waistband member 20L, the engaged portions 25 are bonded to the non-skin side surface of the non-skin side continuous sheet 22a at product pitches between the above-mentioned conveying step S1 and before the fastening portion temporarily fastening step S5 is carried out, but the method for this is not described here.

[0089] In the welding step S6, the ultrasonic welding device 115 (weld forming unit) welds the fastening part 5 to the continuous waistline member 20L to form a welded part F1 in the continuous waistline member 20L. Details of the welding step S6 will be described later.

[0090] After the welding step S6, the substantially ladder-shaped continuous diaper web 1hs passes through the processing position PK5 ( FIG. 9 ) and undergoes a folding step S7 in which the absorbent body 10 is folded in half at a predetermined position CL1 in the cross direction (CD) of the absorbent body 10. This causes the continuous waistline member 20L associated with the ventral waistline portion 20 and the continuous waistline member 30L associated with the dorsal waistline portion 30 to overlap in the thickness direction. This folding can be performed, for example, using a folding guide device (not shown). The folding guide device has, for example, guide plates and guide rollers arranged at predetermined positions in the conveying direction. These guide plates and guide rollers guide the substantially ladder-shaped continuous diaper web 1hs as it passes through the corresponding positions so that the continuous diaper web 1hs is folded in half.

[0091] Next, in the side joint forming process S8, as the folded-in-two continuous diaper web 1hsb passes through the processing position PK6 (FIG. 9), the continuous waistline member 20L for the ventral waistline portion 20 and the continuous waistline member 30L for the dorsal waistline portion 30, which are overlapped in the thickness direction, are welded together at positions on either side of the cutting position PC in the conveying direction to form a pair of side joint regions 2a, 2b. This secures the folded-in-two continuous diaper web 1hsb. As a result, a continuous web of pants-type diapers 1s is produced, consisting of a plurality of pants-type disposable diapers 1, 1... connected in the conveying direction.

[0092] Next, as the pants-type diaper continuous body 1s passes through the processing position PK7, a cutting process S9 is performed in which the continuous body 1s is cut at the cutting target position PC located between the pair of side joint regions 2a, 2b, thereby producing the diaper 1.

[0093] <Regarding the fastening part temporary fixing step S5> The fastening part temporary fixing step S5 (temporary fixing step) will be described in detail below. Fig. 10 is an enlarged view illustrating the temporary fixing part 60 formed in the temporary fixing step S5. Fig. 10 is a view of the material (the continuous waistline member 20L, the absorbent main body 10, etc.) being transported as seen from the skin side, and shows the fastening part 5 and the engaging part 51 in a see-through state. Note that Figs. 11 to 15, which will be described later, also show similar views.

[0094] After the spacing change step S4, in the fastening portion temporary fixing step S5, a heat sealing device 110 is used at a processing position PK3 (FIGS. 8 and 9) to form a temporary fixing portion 60 that temporarily fixes the fastening portion 5 to the continuous waistband member 20L by thermal welding. The heat sealing device 110 has, for example, a pair of rolls that are heated while rotating along the conveyance direction. One roll is a heat embossing roll 110a having protrusions on its outer circumferential surface that correspond to the shape of the temporary fixing portion 60, and the other roll is an anvil roll 110b that receives the protrusions on its smooth outer circumferential surface. Note that, although the present embodiment illustrates the temporary fixing portion 60 by thermal welding using a heat sealing device, the method for joining the temporary fixing portion 60 is not particularly limited and may be, for example, joining by ultrasonic welding, joining by compression without heating, joining with an adhesive, or the like.

[0095] In the fastening portion temporary fastening step S5, the fastening portion 5 is transferred from the re-pitching device 106 to the outer peripheral surface of the anvil roll 110b of the heat-sealing device 110 at processing position PK2, moves along the rotational direction of the roll 110b, and then merges with the continuous waistline member 20L (diaper continuum 1hs) formed in a separate step (step S2) at processing position PK3. At the time of merging, the fastening portion 5 is positioned on the non-skin-facing side of the continuous waistline member 20L, and the engaging portion 51 of the fastening portion 5 is detachably engaged with the engaged portion 25 of the continuous waistline member 20L. The continuous waistline member 20L and the fastening portion 5 are then heat-welded together so that the protrusions of the heat embossing roll 110a abut against the skin-facing side of the joined continuous waistline member 20L, covering the fastening portion 5 from above, forming a plurality of temporary fastening portions 60 (joint portions 60) shown in FIG. 10 .

[0096] By temporarily fastening the fastening part 5 with the temporary fastening part 60 before the welding step S6, which is performed downstream of the temporary fastening step S5, it is possible to prevent the fastening part 5 from shifting or coming off during transport until the welding step S6 is performed, and it is also possible to improve the stability of the subsequent welding step S6. Furthermore, by providing the temporary fastening part 60, it is possible to prevent the fastening part 5 from rolling up due to factors other than the engagement of the welding part F1 and the engagement part 51 formed in the welding step S6. Therefore, it is possible to prevent the fastening part 5 from falling off or folding in the diaper 1 production line 100. Note that the fastening part 60 is preferably fixed weaker than the fastening part F1, which will be described later, so that it can be peeled off by the user by rolling up the fastening part 5.

[0097] 10 , when the base end of the fastening part 5 is defined as the base end 5t and the portion located opposite the base end 5t in the conveying direction as the tip end 5s, it is desirable that in the fastening part temporary fastening step S5, a temporary fastening part 60 is formed on the base end 5t side but not on the tip end 5s side. Note that the "tip end 5s" in this embodiment refers to a portion of the fastening part 5 upstream of the center in the conveying direction (the left-right direction of the product) of the fastening part 5 (the other left-right side, the opposite side from the base end 5t), preferably within a range of one-quarter of the upstream side. The tip end 5s of the fastening part 5 is a portion that a user grips with their fingers to peel off the fastening part 5 when using the product (diaper 1). Not forming the temporary fastening part 60 at this position makes it easier for a user to grip the fastening part 5 and peel it off from the abdominal waistband 20.

[0098] <Regarding the Welding Step S6> The welding step S6 will now be described in detail. Fig. 11 is an enlarged view illustrating the weld F1 formed in the welding step S6. As shown in Figs. 8 and 9 , the continuous waistline member 20L (the diaper continuum 1hs) to which the fastening portions 5 have been temporarily attached is further conveyed in the conveyance direction. In the subsequent welding step S6, an ultrasonic welding device 115 (weld forming unit) is used at a processing position PK4 to form a weld F1 by welding the base end 5t of the fastening portion 5 to the continuous waistline member 20L. As shown in Fig. 11 , the weld F1 that secures the continuous waistline member 20L and the fastening portions 5 functions as a cutting guide portion 40 that guides the user to cut the ventral waistline portion 20 when using the product. In other words, the welding step S6 forms the weld F1 as the cutting guide portion 40 in the continuous waistline member 20L. The cutting guide portion 40 is preferably a portion of the continuous waistband member 20L that has been weakened by thinning it in the thickness direction using an ultrasonic welding device 115.

[0099] In the welding step S6, auxiliary welds F2 and F3 are formed adjacent to and downstream of weld F1 in the conveyance direction at the same time as weld F1 is formed. The shape of weld F1 is not limited to the shape shown in Fig. 11, and the number and shape of auxiliary welds F2 and F3 are not limited to those of this embodiment.

[0100] Conventionally, there have been absorbent articles that are pants-type in the initial product state, have fastening parts like those of the present embodiment on one or both sides in the left-right direction, and can form leg openings by cutting a portion of the waistband and engaging the fastening part with the waistband. When manufacturing such an absorbent article, there has been a process of welding the fastening part to a material that will become the waistband. The fastening part is fixed to the waistband by this welding process, but when used, pulling the fastening part cuts a portion of the waistband in the vertical direction to open it, so a design that makes it easy to tear (tear) is required. For example, if perforations or the like are provided to make the article easy to tear, such perforations or the like must be formed in a process separate from the welding process, and therefore an efficient method is required.

[0101] In this regard, as described above, the welding step S6 of this embodiment welds the waistline continuous member 20L and the fastening portion 5, thereby efficiently bonding the fastening portion 5 and forming the cut guide portion 40 that facilitates cutting the ventral waistline portion 20 in a single step (welding step S6) of forming the welded portion F1. Because the cut guide portion 40 is the welded portion F1, it has greater rigidity than the non-cut guide portion, making it easier to cut the ventral waistline portion 20 during use. In other words, the diaper 1 to be manufactured is configured so that the cut guide portion 40 allows the ventral waistline portion 20 to be cut at the boundary between the welded portion F1 and the non-welded portion.

[0102] 11 , by forming the welded portion F1, the cutting guide portion 40 is formed from one end 20La of the continuous waistline member 20L in the CD direction to the other end 20Lb. If the cutting guide portion 40 were formed along the conveyance direction, an appropriate tension (tension) would be applied to the material conveyed on the production line 100 in the conveyance direction, which could cause cutting starting from the formed cutting guide portion 40 and disrupt the conveyance of the continuous waistline member 20L (diaper continuum 1hs). However, by forming the cutting guide portion 40 along the CD direction, the risk of disruption of the conveyance can be reduced. Furthermore, the cutting guide portion 40 is a portion that guides the ventral waist portion 20 to be cut in the vertical direction (CD direction during transport) from its upper end to its lower end when the product is in use. Therefore, by forming the cutting guide portion 40 in the welding process S6 from one end 20La of the waist continuous member 20L in the CD direction to the other end 20Lb, it becomes easier to promote cutting of the ventral waist portion 20 when in use, improving the usability of the product.

[0103] 11 , in this embodiment, the welded portion F1 is formed to form a partial cut portion 41 in which a portion of the continuous waistline member 20L is cut. Specifically, the welded portion F1 forms a cut guide portion 40, and simultaneously, the partial cut portion 41 is formed by cutting a portion of the continuous waistline member 20L along the cut guide portion 40 (at the boundary between the welded portion F1 and the non-welded portion). Alternatively, the partial cut portion 41 may be formed by varying the welding strength (ultrasonic energy) depending on the position of the cut guide portion 40 in the CD direction. The partial cut portion 41 is a slit that facilitates cutting the ventral waistline portion 20 at the cut guide portion 40 during product use. Due to the cross-sectional configuration of the ventral waistline portion 20, if the partial cut portion 41 is formed separately, it must be formed before the fastening portion 5 is attached. In such a case, the continuous waistline member 20L may break at the partial cut portion 41 before the fastening portion 5 is attached. However, in this embodiment, the base end 5t of the fastening portion 5 is welded to the waistline continuous member 20L, forming a welded portion F1 as a cutting guide portion 40 in the waistline continuous member 20L and simultaneously forming a partial cut portion 41, thereby eliminating this concern.

[0104] Note that the partially cut portions 40 in this embodiment are not limited to being formed in one step (welding step S6) of forming the welded portions F1. For example, after the welded portions F1 are formed, when the continuous waistband member 20L (and the formed welded portions F1 (cutting guide portions 40)) is transported further downstream, tension is continuously applied in the transport direction, and the partially cut portions 41 may be formed by adjusting this tension.

[0105] Furthermore, the partially cut portions 41 formed along the cutting guide portions 40 by forming the welded portions F1 have a predetermined length in the CD direction of the continuous waistline member 20L (see FIG. 11 ). The cutting guide portions 40 guide the ventral waistline portion 20 so that it is cut in the up-down direction from its top to its bottom when the product (diaper 1) is in use. Therefore, by forming the partially cut portions 41 along the cutting guide portions 40, which also have a predetermined length in the CD direction of the continuous waistline member 20L (the up-down direction of the product), the partially cut portions 41 can be formed without interfering with the conveyance state.

[0106] 11 , in the welding step S6 of this embodiment, it is preferable that at least a portion of the partial cut portion 41 overlaps with the engaging portion 51 in the CD direction. This positions the partial cut portion 41 on an extension of the engaging portion 51 in the conveying direction (the left-right direction of the product). In other words, the partial cut portion 41 is positioned on an extension in the conveying direction of the portion where the fastening portion 5 is fixed to the continuous waistline member 20L by the engaging portion 51. By positioning the partial cut portion 41 in a position where the fastening portion 5 is more likely to suppress stretching of the continuous waistline member 20L in the conveying direction, opening of the partial cut portion 41 in the conveying direction can be suppressed, and unintended and unnecessary cutting of the continuous waistline member 20L starting from the partial cut portion 41 can be prevented. If the opening of the partial cut portion 41 in the conveying direction is not suppressed, for example, the entire width in the CD direction of the continuous waistband member 20L will be cut along the cutting guide portion 40, causing the continuous waistband member 20L to separate in the conveying direction, which could result in defective products being produced on the production line 100. However, by forming at least a part of the partial cut portion 41 so that it overlaps with the engaging portion 51 in the CD direction, such an occurrence can be prevented.

[0107] 12A to 12C are diagrams showing modified examples of the formation of the partial cut portion 41. As described above, the partial cut portion 41 can be formed simultaneously with the formation of the welded portion F1 as the cut guide portion 40 in the welding step S6, but this is not limitative. For example, as shown in FIG. 12A , the partial cut portion 41 does not have to be formed. Even in a configuration in which only the cut guide portion 40 is formed without the partial cut portion 41, the ventral waistline portion 20 can be easily cut along the cut guide portion 40 by pinching and pulling the fastening portion 5 when using the product.

[0108] 12B, the partial cut portion 41 may be formed so as not to overlap with the engaging portion 51 in the CD direction. By providing the partial cut portion 41 in a portion that does not overlap with the engaging portion 51, the effect on the continuous waistline member 20L is reduced, and the risk of the cut in the continuous waistline member 20L spreading during conveyance can be reduced. Note that in FIG. 12B, the partial cut portion 41 is provided at one end of the continuous waistline member 20L in the CD direction, but this is not limited thereto, and the partial cut portion 41 may also be provided at the other end of the continuous waistline member 20L in the CD direction. Furthermore, as shown in FIG. 12C, in the welding step S6, multiple partial cut portions 41 may be provided at intervals in the CD direction.

[0109] Fig. 13 is an enlarged view illustrating the cut guide portion 40. As shown in Fig. 13, the cut guide portion 40 formed in the welding step S6 has a one-side inclined portion 40A inclined from the center in the CD direction of the continuous waistline member 20L toward one side and the base end 5t of the fastening portion 5, and a other-side inclined portion 40B inclined from the center in the CD direction toward the other side and the base end 5t of the fastening portion 5. An intersection P of the one-side inclined portion 40A and the other-side inclined portion 40B is located closer to the tip end 5s in the conveyance direction than an outer end 40Ae in the CD direction of the one-side inclined portion 40A and an outer end 40Be in the CD direction of the other-side inclined portion 40B. The fastening portion 5 is a portion that is grasped at the tip 5s and pulled in the left-right direction (the conveying direction during manufacturing) when cutting the ventral waist portion 20 during use, and the inclination of the cutting guide portion 40 is formed in such a shape, making it easier for the pulling force to be applied to the intersection point P, which is the starting point of cutting, and the force is propagated from there along the one-side inclined portion 40A and the other-side inclined portion 40B, making it easier for the ventral waist portion 20 to be cut along the cutting guide portion 40.

[0110] In the above case, the partial cut portion 41 is preferably positioned across the intersection P between the one-side inclined portion 40A and the other-side inclined portion 40B of the cutting guide portion 40. By providing the partial cut portion 41 across the intersection P, the continuous waistband member 20L has already been cut at the intersection P, where tension in the conveying direction is likely to concentrate, making it easier to prevent the partial cut portion 41 from expanding during subsequent conveying.

[0111] Furthermore, it is preferable that at least a portion of the formed partially cut portions 41 overlap with the temporary fastening portions 60 in the CD direction (see, e.g., Figures 11 and 13). This positions the temporary fastening portions 60 on extensions of the partially cut portions 41 in the conveying direction. The temporary fastening portions 60 formed in the fastening portion temporary fastening step S5 strengthen the fixation of the fastening portions 5 to the continuous waistline member 20L, further suppressing elongation of the continuous waistline member 20L in the conveying direction (the left-right direction of the product). The overlapping of such temporary fastening portions 60 and the partially cut portions 41 in the CD direction suppresses opening of the partially cut portions 41 in the conveying direction and suppresses unnecessary cutting of the continuous waistline member 20L starting from the partially cut portions 41 during conveyance.

[0112] 11 and 13 , when the upstream side of the fastening portion 5 in the conveying direction (the side of the tip end 5s in FIG. 11 ) is defined as the upstream side and the downstream side of the fastening portion 5 in the conveying direction (the side of the base end 5t in FIG. 11 ) is defined as the downstream side, the total area of ​​the temporary fastening portions 60 provided per unit area in the downstream side of the fastening portion 5 is larger than the total area of ​​the temporary fastening portions 60 provided per unit area in the upstream side of the fastening portion 5. In the fastening portion 5 temporarily fastened in the fastening portion temporarily fastening step S5, the downstream side is a portion where curling or shifting is likely to occur during conveyance. As shown in FIGS. 11 and 13 , forming more temporary fastening portions 60 in such a downstream side can prevent curling or shifting during conveyance and also facilitates more stable performance of the welding step S6 performed after the fastening portion temporarily fastening step S5.

[0113] As described above, in this embodiment, the waistline continuous member 20L transported on the production line 100 has a skin-side continuous sheet 21a (first sheet material) in which the skin-side sheet 21 (first sheet) is continuous in the transport direction, a non-skin-side continuous sheet 22a (second sheet material) in which the non-skin-side sheet 22 (second sheet) is continuous in the transport direction, and a waistline elastic continuous member 23a in which the waistline elastic member 23 is continuous in the transport direction, and the waistline elastic continuous member 23a is joined in a stretched state between the skin-side continuous sheet 21a (first sheet material) and the non-skin-side continuous sheet 22a (second sheet material) (see Figure 9). In the diaper 1 manufactured by the manufacturing method of the diaper 1 of this embodiment, the waistline elastic continuous members 23a, 33a are cut at the portions where the waistline continuous member 20L and the absorbent body 11 overlap in the thickness direction and at the portions where the waistline continuous member 30L and the absorbent body 11 overlap in the thickness direction, respectively, to make the waistline elastic continuous members 23a, 33a discontinuous (see FIG. 2 ). As a result, the diaper 1 does not exhibit lateral stretchability in the discontinuous portions, ensuring flatness and suppressing shrinkage of the absorbent main body 10. Similarly, in the welding step S6 of welding the fastening parts 5, it is preferable to form the welded portions F1 and simultaneously cut the waistline elastic continuous member 23a. Because the waistline elastic member 23 (the waistline elastic continuous member 23a) is discontinuous in the region where the fastening parts 5 are present and does not exhibit stretchability, shrinkage in the region where the fastening parts 5 are present can be suppressed. Suppressing shrinkage makes the fastening parts 5 less prone to wrinkles and improves usability of the product.

[0114] FIG. 14 is a diagram illustrating the details of the welded portion F1, the auxiliary welded portion F2, and a portion of the auxiliary welded portion F3. When forming the welded portion F1 in the above-described welding step S6, it is preferable to form the welded portion F1 so that a portion of the welded portion F1 does not form a continuous line. Preferably, the welded portion F1 is formed so that at least the outer end portion of the welded portion F1 in the CD direction does not form a continuous line. In this embodiment, as shown in FIG. 14 , when forming the welded portion F1 in the welding step S6, a plurality of discontinuous portions 43 where the welded portion F1 does not form a continuous line are formed on both outer sides (one side and the other side) of the center portion of the welded portion F1 in the CD direction. The discontinuous portions 43 are so-called non-welded portions. Because the welded portion F1 does not form a continuous line, the discontinuous portions 43 (non-welded portions) are connected to a portion of the continuous waistline member 20L without being welded. By forming the welded portion F1 (cutting guide portion 40) and forming a non-continuous portion 43 (non-welded portion) to which a part of the continuous waistband member 20L is connected together with the cutting guide portion 40, the continuous waistband member 20L is prevented from being cut all the way to the end in the CD direction during transport, and the flow of the production line 100 is not interrupted.

[0115] Furthermore, the fastening portion 5 has an engaging portion 51 that detachably engages with the non-skin-side surface of the continuous waistline member 20L (ventral waistline portion 20). As described above, when forming the discontinuous portion 43, the discontinuous portion 43 is preferably formed at a position that does not overlap the engaging portion 51 in the CD direction. When the cut guide portion 40 is formed in the welding step S6, the engaging portion 51 is in a state of detachably engaging with the engaged portion 25 of the continuous waistline member 20L. Therefore, in the region where the engaging portion 51 is present, the engagement between the continuous waistline member 20L and the engaging portion 51 prevents the partial cut portion 41 from opening in the conveyance direction, as described above, and prevents the tear from spreading from the partial cut portion 41. Furthermore, forming the discontinuous portion 43 at a position that does not overlap the engaging portion 51 makes it easier to prevent the cut originating from the partial cut portion 41 from spreading even in regions where the engaging portion 51 is not present.

[0116] In this embodiment, the discontinuous portions 43 are formed on both sides of the cutting guide portion 40 (welded portion F1) in the CD direction. However, this is not limited thereto; the discontinuous portions 43 may be formed on at least one side of the cutting guide portion 40 in the CD direction. Furthermore, three discontinuous portions 43 are formed on each side of the cutting guide portion 40 (welded portion F1) in the CD direction. However, the number of discontinuous portions 43 may be one or more. The length of each discontinuous portion 43 in the CD direction is preferably approximately 0.5 mm, and the distance between adjacent discontinuous portions 43 in the CD direction is preferably approximately 6 mm. Furthermore, when a partial cut portion 41 is formed in the center of the cutting guide portion 40 in the CD direction, as in this embodiment, the distance from the center position of the cutting guide portion 40 in the CD direction (the position of the intersection P in FIG. 13 ) to the discontinuous portion 43 located innermost in the CD direction among the multiple discontinuous portions 43 formed is preferably approximately 29 mm.

[0117] Furthermore, at the same time as forming the welded portion F1 in the welding step S6, auxiliary welded portions F2 and F3, separate from the welded portion F1, are formed adjacent to the cutting guide portion 40 (welded portion F1) from the base end 5t side of the fastening portion 5 in the conveyance direction. As shown in the enlarged view of FIG. 14 , at least a portion of the discontinuous portion 43 overlaps with the auxiliary welded portion F2 (F3) in the CD direction. By forming the auxiliary welded portion F2 (F3), the tensile strength concentrated on the discontinuous portion 43 can be alleviated by the auxiliary welded portion F2 (F3). This prevents the continuous waistline member 20L from breaking in the conveyance direction during conveyance.

[0118] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0119] Fig. 15 is a diagram illustrating a manufacturing method in which fastener portions 5 are provided on both lateral sides of the diaper 1. In the above-described embodiment, a method for manufacturing the diaper 1 in which the fastener portion 5 is provided on one lateral side of the product has been described. However, as shown in Fig. 15, the fastener portions 5 may be provided on both lateral sides of the diaper 1. In this case, mainly in the fastener portion temporary fastening step S5 and the welding step S6 in the above-described embodiment, the fastener portions 5, 5 are arranged on both the upstream and downstream sides in the conveyance direction so that the tip ends 5s of the fastener portions 5 face each other, and then welded to the continuous waistline member 20L. The methods for forming the welded portion F1 (cutting guide portion 40), the auxiliary welded portions F2 and F3, and the partial cut portion 41 are the same as those in the above-described embodiment.

[0120] Furthermore, in the above-described embodiment, a method for welding the fastening portion 5 to the waistline continuous member 20L for forming the ventral waistline portion 20 (welding step S6) has been described, but the same method can also be used to weld the fastening portion 5 to the waistline continuous member 30L for forming the dorsal waistline portion 30.

[0121] DESCRIPTION OF SYMBOLS 1 Disposable diaper (pants-type absorbent article) 1h Unfolded diaper, 1hs Diaper continuum 1hsb Diaper continuum, 1s Pants-type diaper continuum 2a Side joint portion, 2b Side joint portion 5 Fastening portion 5K Fastening portion base sheet 5s Distal end portion, 5t Base end portion 10 Absorbent body 11 Absorbent body 11A Absorbent core 12 Top sheet 13 Second sheet 14 Side sheet 15 Back sheet 16 Outer sheet 17 Leg-hole elastic member 18 Leak-barrier elastic member 20 Abdominal waist portion 20L Waist continuous member 20La One end 20Lb Other end 21 Skin-side sheet 21a Skin-side continuous sheet 22 Non-skin-side sheet 22a Non-skin-side continuous sheet 23 Waist elastic member 23a DESCRIPTION OF THE SYMBOLS: Waistline elastic continuous member 25 Engaged portion 30 Back-side waistline portion 30L Waistline continuous member 31 Skin-side sheet 31a Skin-side continuous sheet 32 ​​Non-skin-side sheet 32a Non-skin-side continuous sheet 33 Waistline elastic member 33a Waistline elastic continuous member 40 Cutting guide portion 40A One-side inclined portion 40Ae Outer end 40B Other-side inclined portion 40Be Outer end 41 Partially cut portion 43 Discontinuous portion 51 Engaging portion 60 Temporarily fastened portion (joint portion) 80 Crotch portion 100 Production line 105 Die cutter device 106 Re-pitching device 106P Holding pad 110 Heat sealing device 110a Heat embossing roll 110b Anvil roll 115 Ultrasonic welding device

Claims

1. A method for manufacturing a pants-type absorbent article having a waist portion and a fastening portion, comprising: a conveying step of conveying the waist continuous member in a conveying direction to form the waist portion; and a welding step of welding a base end of the fastening portion to the waist continuous member to form a welded portion as a cutting guide portion in the waist continuous member.

2. A method for manufacturing a pants-type absorbent article as described in claim 1, characterized in that by forming the welded portion, a partial cut portion is formed in which a part of the waistline continuous member is cut.

3. A method for manufacturing a pants-type absorbent article as described in claim 1 or 2, characterized in that, when a direction intersecting the conveying direction is defined as a CD direction, the welded portion is formed to form the cutting guide portion from one end of the waistline continuous member in the CD direction to the other end.

4. A method for manufacturing a pants-type absorbent article as described in claim 1 or 2, characterized in that, when a direction intersecting the conveying direction is defined as a CD direction, the cut guide portion has a one-side inclined portion inclined from a center portion in the CD direction toward one side and the base end side of the fastening portion, and an other-side inclined portion inclined from the center portion toward the other side and the base end side of the fastening portion, and when a portion of the fastening portion located on the opposite side of the conveying direction from the base end is defined as a tip portion, an intersection of the one-side inclined portion and the other-side inclined portion is located on the tip side in the conveying direction relative to the outer end of the one-side inclined portion in the CD direction and the outer end of the other-side inclined portion in the CD direction.

5. A method for manufacturing a pants-type absorbent article as described in claim 2, characterized in that, when a direction intersecting the conveying direction is defined as a CD direction, by forming the welded portion, the partial cut portion having a predetermined length in the CD direction of the waistline continuous member is formed along the cutting guide portion.

6. A method for manufacturing pants-type absorbent articles as described in claim 1 or 2, characterized in that it includes a spacing change process for changing the attachment spacing of the fastening parts to a spacing appropriate to the product size prior to the welding process.

7. A method for manufacturing a pants-type absorbent article as described in claim 6, characterized in that it includes a temporary fixing process for forming a temporary fixing portion for temporarily fixing the fastening portion to the waistline continuous member after the interval changing process and before the welding process.

8. A method for manufacturing pants-type absorbent articles as described in claim 7, characterized in that in the temporary fastening process, the temporary fastening portion is not formed at the tip end of the fastening portion that is located on the opposite side of the conveying direction from the base end.

9. A method for manufacturing a pants-type absorbent article as described in claim 7, characterized in that, when the upstream side of the fastening part in the conveying direction is defined as the upstream side and the downstream side of the fastening part in the conveying direction is defined as the downstream side with respect to the cutting guide part, the total area of ​​the temporary fastening parts provided per unit area of ​​the downstream side of the fastening part is larger than the total area of ​​the temporary fastening parts provided per unit area of ​​the upstream side of the fastening part.

10. A method for manufacturing a pants-type absorbent article as claimed in claim 1 or 2, characterized in that the waist portion has a first sheet, a second sheet, and a waist elastic member provided between the first sheet and the second sheet, the waist continuous member has a first sheet material to which the first sheet is continuous in the conveying direction, a second sheet material to which the second sheet is continuous in the conveying direction, and a waist elastic continuous member to which the waist elastic member is continuous in the conveying direction, the waist elastic continuous member being joined in a stretched state between the first sheet material and the second sheet material, and in the welding process, the waist elastic continuous member is cut by forming the welded portion.

11. A method for manufacturing pants-type absorbent articles as described in claim 1 or 2, characterized in that, when a direction intersecting the conveying direction is defined as a CD direction, in the welding process, the welded portions are formed so that the outer ends of the welded portions in the CD direction do not form a continuous line.

12. A method for manufacturing a pants-type absorbent article as described in claim 11, wherein the fastening portion has an engaging portion that detachably engages with the non-skin side of the waist portion, and when a portion where the welded portion does not form a continuous line is defined as a discontinuous portion, the discontinuous portion is provided at a position that does not overlap with the engaging portion in the CD direction.

13. A method for manufacturing a pants-type absorbent article as described in claim 2, wherein the fastening portion has an engaging portion that detachably engages with the non-skin side of the waist portion, and when a direction intersecting the conveying direction is defined as a CD direction, in the welding process, at least a part of the partial cut portion is formed so as to overlap with the engaging portion in the CD direction.

14. A method for manufacturing a pants-type absorbent article as described in claim 2, wherein the fastening portion has an engaging portion that detachably engages with the non-skin side of the waist portion, and when a direction intersecting the conveying direction is defined as a CD direction, in the welding process, the partial cut portion is formed so as not to overlap with the engaging portion in the CD direction.

15. A method for manufacturing a pants-type absorbent article as described in claim 2, characterized in that, when a direction intersecting the conveying direction is defined as a CD direction, the cut guide portion has a one-side inclined portion inclined from a center portion in the CD direction toward one side and the base end side of the fastening portion, and an other-side inclined portion inclined from the center portion toward the other side and the base end side of the fastening portion, and the partial cut portion is located across an intersection of the one-side inclined portion and the other-side inclined portion.

16. A method for manufacturing a pants-type absorbent article as described in claim 7, characterized in that by forming the welded portion, a partial cut portion is formed in which a part of the waistline continuous member is cut, and when a direction intersecting the conveying direction is defined as a CD direction, at least a part of the partial cut portion overlaps with the temporary fastening portion in the CD direction.

17. A method for manufacturing a pants-type absorbent article as described in claim 12, characterized in that in the welding step, when forming the welded portion, an auxiliary welded portion separate from the welded portion is formed by welding the base end of the fastening portion to the waistline continuous member, the auxiliary welded portion is adjacent to the cutting guide portion from the base end side of the fastening portion in the conveying direction, and at least a portion of the discontinuous portion overlaps with the auxiliary welded portion in the CD direction.

18. A manufacturing apparatus for pants-type absorbent articles having a waist portion and a fastening portion, comprising: a conveying section that conveys the waist continuous member for forming the waist portion in a conveying direction; and a welding forming section that welds a base end of the fastening portion to the waist continuous member to form a welded portion as a cutting guide portion in the waist continuous member.

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