JP6549206B2 - METHOD FOR MANUFACTURING ABSORBENT ARTICLE AND APPARATUS FOR MANUFACTURING ABSORBENT ARTICLE - Google Patents

Description

  The present invention relates to a method of manufacturing an absorbent article and an apparatus for manufacturing an absorbent article.

  BACKGROUND Conventionally, absorbent articles such as so-called pants-type disposable diapers and tape-type disposable diapers are known. For example, in Patent Document 1, the waist opening W and the pair of leg openings are formed by joining the side edges of the ventral side sheet member 2 and the back side sheet member 3 to form the pair of side seal portions S. A pants-type disposable diaper 1 provided with LO, LO is disclosed.

JP, 2013-13683, A

  However, when the pants-type disposable diaper 1 as in Patent Document 1 is worn or to be worn, a force in the direction along the elastic member 7 of the ventral sheet member 2 and the back sheet member 3 is applied. The bonding of the side seal portion S may be peeled off.

  The present invention has been made in view of the problems as described above, and it is an object of the present invention to further strengthen welding and joining of members of an absorbent article.

The main invention for achieving the above object is a first member provided with two sheet members provided with at least one non-woven fabric and an elastic member expandable in the left-right direction, a second member provided with a non-woven fabric, and the first member It is a manufacturing method of an absorptive article which has a welding part welded with the 2nd member, and in the thickness direction which intersects the left-right direction of the 1st member, between the two above-mentioned sheet members, the above-mentioned right and left An elastic member disposing step of arranging the elastic member in an extended state extended in a direction, an overlapping step of overlapping the second member in the thickness direction of the first member, and relaxing the extended state And a welding step of welding one end of the first member in the left-right direction and one end of the second member in the left-right direction to form the welded portion. And the palliative worker After a manufacturing method for absorbent articles which is characterized in that the welding process in the relaxed state.
Other features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

  According to the manufacturing method of such an absorbent article, by performing welding after relaxing the expansion of the elastic member, it is possible to increase the basis weight of the non-woven fabric of the first member in the welded portion, so in the welded portion Welding between the first member and the second member can be further strengthened.

FIG. 1 is a schematic perspective view of a shorts-type disposable diaper 1. FIG. 2A is a schematic plan view of the unfolded and stretched diaper 1 as viewed from the skin side. FIG. 2B is a schematic cross-sectional view taken along the line XX in FIG. 2A. FIG. 3 is a schematic plan view of the ventral-side member 30 in the unfolded state and the extended state as viewed from the non-skin side. FIG. 4 is a flowchart showing the manufacturing process of the diaper 1. FIG. 5: is a schematic plan view which shows a mode that the diapar 1 is manufactured by a production line in a perspective view in part. FIG. 6A is a schematic enlarged view of a part A in FIG. FIG. 6B is a schematic enlarged view of part B in FIG. FIG. 6C is a schematic enlarged view of a portion C in FIG. FIG. 6D is a schematic enlarged view of part D in FIG. FIG. 7A is a schematic view illustrating a cross section indicated by arrow aa in FIG. 6A. FIG. 7B is a schematic view explaining a cross section indicated by the arrow b-b in FIG. 6B. FIG. 7C is a schematic view illustrating a cross section indicated by a arrow c-c in FIG. 6C. FIG. 7D is a schematic view explaining a cross section shown by a d-d arrow in FIG. 6D. FIG. 8 is a schematic enlarged view of a region D in FIG. 6D. FIG. 9 is a diagram for explaining another embodiment.

At least the following matters will be made clear by the present specification and the description of the accompanying drawings.
A welded portion in which two sheet members provided with at least one non-woven fabric and a first member provided with an elastic member expandable in the left-right direction, a second member provided with non-woven fabric, and the first and second members A method of manufacturing an absorbent article, comprising: the elastic member in a stretched state in which the sheet member is stretched between two sheet members in a thickness direction intersecting the left and right direction of the first member An elastic member disposing step of disposing the first member, an overlapping step of overlapping the second member in the thickness direction of the first member, a relaxing step of relaxing the extended state to a relaxed state, the first step And welding the one end of the member in the left and right direction and the one end of the second member in the left and right direction to form the welded portion, the relaxation step being performed after the relaxation step. Said welding in state It is a manufacturing method for absorbent articles and performs extent.

  According to the manufacturing method of such an absorbent article, by performing welding after relaxing the expansion of the elastic member, it is possible to increase the basis weight of the non-woven fabric of the first member in the welded portion, so in the welded portion Welding between the first member and the second member can be further strengthened.

  In the manufacturing method of such an absorbent article, in the relaxation step, the elastic member is relaxed so as to be in a state between the stretched state and the natural state, and the sheet member is divided into a plurality of in the lateral direction. It is desirable to make the eyelids form.

  According to such a method of manufacturing an absorbent article, the first member can perform welding in the welding step performed after the relaxation step at a more accurate position than when the elastic member is completely in the natural state.

  In the method of manufacturing such an absorbent article, the sheet member is a first sheet member, the elastic member is a first elastic member, and the second member is a pair of at least one non-woven fabric. It is desirable to be equipped with the 2 sheet member and the 2nd elastic member which can be expanded-contracted to the left-right direction.

  According to the manufacturing method of such an absorbent article, since welding between the first member and the second member can be made stronger, in the underpants type diaper, bonding between the ventral waistline portion and the back waistline portion Can be made more robust.

  The method for manufacturing such an absorbent article includes a sheet welding step of forming a sheet welding portion for welding the first sheet members, and the sheet welding step is performed after the elastic member disposing step. The sheet welding portion is intermittently arranged from one end to the other end of the first sheet member in the left-right direction in the sheet welding step in the sheet welding step, and is performed along the left-right direction. A welding row is formed, and the welding row is formed at least two rows at predetermined intervals in the vertical direction intersecting the left and right direction, and the first elastic member is the welding row adjacent in the vertical direction It is preferable that the predetermined interval be longer than the thickness of the first elastic member in the stretched state and shorter than the thickness of the first elastic member in the natural state.

  According to the manufacturing method of such an absorbent article, since it is not necessary to adhere an elastic member with an adhesive agent, a 1st member can be softened more than the case where an elastic member is adhered with an adhesive agent.

In the method of manufacturing the absorbent article, the first member is continuous in the left-right direction in the elastic member disposing step, the sheet welding step, the overlapping step, the relaxation step, and the welding step. Yes,
After the welding step, the method includes a cutting step of cutting the first continuous member in a continuous state to form the first member in a cut state, and in the cutting step, the elongation state is relaxed. It is desirable to do in the state of

  According to the manufacturing method of such an absorbent article, the elastic member becomes thicker than the expanded state by performing the cutting process in the state where the expansion of the elastic member is relaxed, and thus the state fixed by the sheet welding portion As a result, even if the first member is cut, the risk of the elastic member coming off the sheet welding portion can be reduced. Further, in order to reduce the force of the elastic member to contract, it is possible to reduce the possibility that the elastic member may come out of being fixed by the sheet welding portion after the first member is cut.

  In the method of manufacturing such an absorbent article, it is preferable that the welded portion be formed at a position overlapping the at least one sheet welded portion in the thickness direction in the welding step.

  According to the manufacturing method of such an absorbent article, when the weld is formed on the ridge formed between the sheet welds adjacent in the left and right direction, the basis weight of the non-woven fabric of the first member in the weld is increased. Since welding can be performed, welding between the first member and the second member in the welding portion can be further strengthened.

  In the method of manufacturing such an absorbent article, it is preferable that the welded portion be formed at a position overlapping the two or more sheet welded portions in the thickness direction in the welding step.

  According to the manufacturing method of such an absorbent article, when the welded portion is formed on the ridge formed between the sheet welded portions adjacent in the lateral direction, the basis weight of the non-woven fabric of the first member in the welded portion is made more Since it can be made to increase reliably, welding with the 1st member and the 2nd member in a welding part can be strengthened more.

  In the method of manufacturing such an absorbent article, a plurality of the welding portions are disposed along the vertical direction, and the distance between the welding portions adjacent in the vertical direction is longer than the predetermined distance. desirable.

  According to such a method of manufacturing an absorbent article, the elastic member is cut by the welds compared to the case where the length between the welds adjacent in the vertical direction is shorter than the length between the weld rows. It can reduce fear.

  In the method of manufacturing the absorbent article, it is desirable that the length of the welded portion in the left-right direction be longer than the length of the welded portion of the sheet in the left-right direction.

  According to the manufacturing method of such an absorbent article, the basis weight of the non-woven fabric of the first member in the welded portion is smaller than in the case where the length in the left and right direction of the welded portion is shorter than the length in the left and right direction of the sheet welded portion. Since it can be made to increase more reliably, welding of the 1st member and the 2nd member in a welding part can be strengthened more.

  In the method of manufacturing such an absorbent article, a plurality of the first elastic members are provided, and a plurality of the welding portions are disposed along the vertical direction, and the first adjacent to each other in the vertical direction. It is desirable that the distance between the elastic members be larger than the length in the vertical direction of the welded portion.

  According to the manufacturing method of such an absorbent article, the risk of the first elastic member being cut by the welded portion can be reduced.

  A welded portion in which two sheet members provided with at least one non-woven fabric and a first member provided with an elastic member expandable in the left-right direction, a second member provided with non-woven fabric, and the first and second members The elastic member in the stretched state in which the sheet member is stretched between the two sheet members in the thickness direction intersecting the left and right direction of the first member. An elastic member disposing portion for disposing the second member, an overlapping portion for overlapping the second member in the thickness direction of the first member, a relaxing portion for relieving the extension state to a relaxing state, The welding formation part which welds the one end of the above-mentioned horizontal direction of a member, and the one end of the above-mentioned horizontal direction of the above-mentioned 2nd member, and forms the welded part, After relaxing the growth of , In the weld formation portion, in the relaxed state, a manufacturing apparatus of an absorbent article and forming the weld portion.

  According to the manufacturing apparatus of such an absorbent article, by performing welding after relaxing the expansion of the elastic member, it is possible to increase the basis weight of the non-woven fabric of the first member in the welded portion, so in the welded portion Welding between the first member and the second member can be further strengthened.

=== Embodiments ===
The manufacturing method and manufacturing apparatus of the absorbent article of this embodiment are used, for example, in a manufacturing line of the disposable diaper 1 as an example of the absorbent article. FIG. 1 is a schematic perspective view of a shorts-type disposable diaper 1. As an example of the absorbent article, the following embodiment will be described by taking a so-called three-piece type diaper 1 shown in FIG. 1 as an example. The pants-type disposable diaper of the present embodiment can be used for infants and adults. The absorbent article according to the present invention can also be used as a pants-type disposable diaper, a tape-type disposable diaper for adults as well as infants and a shorts-type napkin for menstruation.

=== Basic configuration of pants type disposable diaper 1 ===
FIG. 2A is a schematic plan view of the unfolded and stretched diaper 1 as viewed from the skin side. FIG. 2B is a schematic cross-sectional view taken along the line XX in FIG. 2A. FIG. 3 is a schematic plan view of the ventral-side member 30 in the unfolded state and the extended state as viewed from the non-skin side. The “deployed state” refers to the side portions (also referred to as “ends”) 30 a of the ventral members (also referred to as “first members”) 30 a and the back members 40 (“second The connection with the side portion (also referred to as “end portion”) 40 a of the member is separated, respectively, and opened, and the entire diaper 1 is developed in a planar manner. The "stretched state" indicates a state in which the elastic member provided in the diaper 1 is stretched to such an extent that the wrinkles of the diaper 1 can not be visually recognized. Specifically, a state is shown in which the dimensions of each member (for example, belly-side member 30 described later, etc. described later) constituting the diaper 1 are expanded to a size that matches or is close to the size of the single member. The line C-C in FIG. 2 is a center line in the left-right direction. In FIG. 2B, the adhesive is omitted for convenience. In the following description, the configuration described for the ventral-side member 30 is the same as the configuration of the back-side member 40.

  As shown in FIG. 1, the pants-type diaper 1 has a vertical direction, a lateral direction, and a longitudinal direction, and the diaper 1 is formed with a waist opening BH and a pair of leg openings LH. In the vertical direction, the waist opening BH side is the upper side, and the crotch side of the wearer is the lower side. The vertical direction of the diaper 1 in the state of FIG. 2A (deployed and extended) is referred to as “longitudinal direction”, one side in the longitudinal direction as “abdominal side”, and the other side as “back side”. The side is also called "lower side". In the front-rear direction, the front side of the wearer is referred to as the front side, and the back side of the wearer is referred to as the back side. Moreover, the diaper 1 has a thickness direction as shown to FIG. 2B, and let the side which contacts a wearer be a skin side in the thickness direction, and let the other side be a non-skin side.

  The diaper 1 is a so-called three-piece type, and has an absorbent main body 10, an abdominal member 30, and a dorsal member 40. The ventral-side member 30 and the back-side member 40 have a substantially rectangular shape in plan view, and the longitudinal direction is along the left-right direction. The ventral member 30 covers the wearer's ventral side and the back member 40 covers the wearer's dorsal side. The absorptive main body 10 is a planar view substantially rectangular shape. The ventral end 10ea and the dorsal end 10eb of the absorbent main body 10 are respectively overlapped with the skin side of the ventral member 30 and the dorsal member 40.

  As shown in the unfolded state of FIG. 2A, the diaper 1 has a symmetrical shape with respect to the center line C-C. The non-skin side of the ventral end 10ea and the dorsal end 10eb of the absorbent main body 10 and the skin side of the ventral member 30 and the dorsal member 40 are joined with an adhesive (not shown), as shown in FIG. 2A. From the unfolded state shown, the absorbent main body 10 is folded in half so that the ventral side member 30 and the back side member 40 face each other, and both sides 30a of the ventral side member 30 in the left and right direction The diaper 1 becomes a pants type by welding and joining the portion 40a with the side welding portion SS.

  The ventral-side member 30 and the back-side member 40 respectively include two flexible sheet members such as nonwoven fabric (skin-side sheet member 31 and non-skin-side sheet member 32, skin-side sheet member 41 and non-skin-side sheet member 42) And a plurality of thread rubbers (elastic members) 35 and 45 that expand and contract in the left-right direction. The plurality of thread rubbers 35 and 45 are arranged side by side at intervals in the vertical direction, and are fixed between two sheet members (31 and 32, 41 and 42) in a state of being stretched in the horizontal direction There is. Therefore, the ventral-side member 30 and the back-side member 40 can expand and contract in the left-right direction, and fit around the waist of the wearer.

  The absorbent main body 10 includes a top sheet 13, an absorber 11, and a back sheet 15, and they are bonded by an adhesive such as hot melt. The top sheet 13 may be a liquid permeable sheet, and examples thereof include hydrophilic air through non-woven fabric and spun-bonded non-woven fabric. The back sheet 15 may be a liquid impervious sheet, and may be a polyethylene film, a polypropylene film, a hydrophobic SMS non-woven fabric, or the like. The top sheet 13 and the back sheet 15 are sized to cover the entire absorbent body 11.

  The absorber 11 has a substantially rectangular shape in plan view, and includes an absorbent core 11 c that absorbs a liquid. The absorbent core 11c is formed by molding a liquid absorbent fiber such as pulp fiber, and may contain a high absorbent polymer (so-called SAP) or the like.

  In addition, the absorbent main body 10 is a leg gathers LG extended in the longitudinal direction provided at the end in the left and right direction, and a leakage preventing wall provided on the skin side with respect to the absorber 11 for preventing lateral leakage. A solid gather LSG is formed by the back sheet 15. The leg gather LG and the solid gather LSG each include an elastic member 17 and an elastic member 18 which extend in the longitudinal direction (vertical direction).

  In the belly side member 30, a skin side sheet 31, an elastic member (first elastic member) 35, and a non-skin side sheet 32 are sequentially stacked in the thickness direction from the skin side, as shown in FIG. It welds and joins by the some sheet welding part j distribute | arranged discretely to longitudinal direction and the left-right direction. Similarly, in the back side member 40, the skin side sheet 41, the elastic member (second elastic member) 45, and the non-skin side sheet 42 are sequentially stacked in the thickness direction from the skin side, and are discrete in the vertical and horizontal directions. It welds and joins by the several sheet | seat welding part j distribute | arranged. The thread rubbers 35 and 45 are not bonded with an adhesive.

  The skin side sheets 31 and 41 and the non-skin side sheets 32 and 42 are respectively sheets made of non-woven fabric, and specifically, are spun bond non-woven fabric. However, not limited to this, non-woven fabric such as SMS (spun bond / melt blown / spun bond) non-woven fabric may be used. Moreover, in this embodiment, although the single fiber of the polypropylene (PP) of a thermoplastic resin is used as a constituent fiber of a nonwoven fabric, it is not restricted to this. For example, single fibers of other thermoplastic resins such as polyethylene (PE) may be used, or composite fibers having a sheath-core structure such as PE and PP may be used. Furthermore, all of the skin side sheets 31 and 41 and the non-skin side sheets 32 and 42 may not be non-woven fabric, and any one of the skin side sheets 31 and 41 or the non-skin side sheets 32 and 42 is other than non-woven fabric Other soft sheet materials may be used.

  The sheet welding portion j is intermittently arranged from one end to the other end of the ventral-side member 30 in the left-right direction, and forms a welding row L along the left-right direction. A plurality of welding rows L are provided in the vertical direction. The rubber thread 35 is provided between the welding rows L adjacent in the vertical direction. Specifically, in FIG. 5, the rubber thread 35 is provided between the upper welding row L1 and the lower welding row L2. That is, the possibility of the rubber thread 35 moving excessively in the vertical direction is reduced by the sheet welding portion j provided in the vertical direction.

=== Manufacturing method of pants type disposable diaper 1 ===
Hereinafter, the manufacturing method of the diaper 1 is demonstrated. FIG. 4 is a flowchart showing the manufacturing process of the diaper 1. FIG. 5: is a schematic plan view which shows a mode that the diapar 1 is manufactured by a production line in a perspective view in part. FIG. 6A is a schematic enlarged view of a part A in FIG. FIG. 6B is a schematic enlarged view of part B in FIG. FIG. 6C is a schematic enlarged view of a portion C in FIG. FIG. 6D is a schematic enlarged view of part D in FIG. FIG. 7A is a schematic view illustrating a cross section indicated by arrow aa in FIG. 6A. FIG. 7B is a schematic view explaining a cross section indicated by the arrow b-b in FIG. 6B. FIG. 7C is a schematic view illustrating a cross section indicated by a arrow c-c in FIG. 6C. FIG. 7D is a schematic view explaining a cross section shown by a d-d arrow in FIG. 6D.

  In FIG. 5 and the like, a direction orthogonal to the thickness direction of each of the sheets 31, 32, 41, and 42 and the transport direction is referred to as "CD direction" or "vertical direction", and the transport direction is also referred to as "horizontal direction". Moreover, in FIG. 6A-FIG. 6D and FIG. 7A-FIG. 7D, although the abdominal side member 30 is demonstrated hereafter, the same may be said of the back side member 40. FIG. P1 shown in FIG.5 and FIG.6A-FIG. 6D sets the boundary position BL between the diapar 1 and 1 comrades which continue in a left-right direction virtually as a product pitch P1 in a conveyance direction. And CL is the cutting position CL which cut | disconnects the boundary position BL as a cutting object position in the 9th process position PK9 located in the end of this manufacturing line. 7A is a cross-sectional view taken along line a-a in FIG. 6A, a cross-sectional view taken along line b-b in FIG. 6B shown in FIG. 7B, and c-c in FIG. 6C shown in FIG. The cross-sectional view shown by the eye and the cross-sectional view shown by the arrows d in FIG. 6D shown in FIG.

  As shown in FIG. 4, the belly-side member 30 can be obtained by performing the non-skin-side sheet conveyance step (S301), the thread rubber placement step (S302), the skin-side sheet placement step (S303), and the sheet member welding step (S304). The back side member 40 is formed by performing the non-skin side sheet conveyance step (S401), the thread rubber placement step (S402), the skin side sheet placement step (S403), and the sheet welding step (S404). And the diaper 1 is formed by performing an absorptive main body arrangement | positioning process (S505), a superposition | stacking process (S506), a relaxation process (S507), a side welding process (S508), and a cutting process (S509).

  Each step will be described below with reference to FIG. In addition, in each process until it cuts into each diaper 1 at a cutting process (S508), each member (skin side sheet 31, 41, non-skin side sheet 32, 42, thread rubber 35, 45, diaper 1) Are each continuous in the transport direction.

  First, at the first processing position PK1, the non-skin-side sheet conveyance step (S301, S401) is performed. Specifically, the non-skin side sheets 32 and 42 in a continuous state in the transport direction are respectively transported toward the downstream in the transport direction using a transport device such as a transport roller (not shown).

  Next, in the second processing position PK2, a thread rubber arranging step (S302, S402) is performed. In the thread rubber arranging step, a plurality of thread rubbers 35 and 45 in a continuous state in the transport direction are separated from each other in the CD direction from the upper side in the thickness direction of the transported non-skin side sheets 32 and 42 respectively. Place it. The rubber thread is arranged by a conveying device (elastic member arranging portion) such as a conveying roller (not shown). The thread rubbers 35 and 45 in the thread rubber disposing step are in an extended state in which they are extended to a predetermined extension ratio.

  The extension ratio is R (R = E1 / E0) indicating how many times the total length E1 of each of the rubber threads 35 and 45 is extended to the total length E0 in the unloaded state (natural state) which is the natural length. And predetermined expansion magnification R in this embodiment can be chosen from R = 1.5-4.0, for example. In this embodiment, R = 2.0.

  Subsequently, in the third processing position PK3, the skin side sheet disposing step (S303, S403) is performed. In the skin side sheet disposing step, the skin side sheets 31 and 41 are placed from the upper side in the thickness direction of the non-skin side sheets 32 and 42 in which the thread rubbers 35 and 45 are disposed. As a result, as shown in FIG. 6A, in the portion A after the non-skin sheet placement step (S303, S403), the stretched rubber thread 35 is held between the skin sheet 31 and the non-skin sheet 32. It becomes. Then, the sheet is conveyed downstream in the conveying direction.

  At this time, as shown in FIG. 7A, the stretched rubber thread 35 is thinner than the thickness of the natural rubber thread 35 by the amount of stretching. Moreover, since the skin side sheet 31 and the non-skin side sheet 32 are conveyed so as to be pulled from the downstream side in the conveyance direction, the skin side sheet 31 and the non-skin side sheet 32 are conveyed with an appropriate tension applied.

  Subsequently, the sheet member welding step (S304, S404) is performed at the fourth processing position PK4. B part in FIG. 5 has shown the state after the sheet member welding process. In the sheet member welding step, the skin side sheet 31 and the non-skin side sheet are joined at a plurality of sheet welding portions j, j, ... to form the belly side member 30 and the back side member 40. The sheet welding portion j is from one end to the other end in the left-right direction of the abdominal side member 30 and the back side member 40, that is, from the area of the cutting position CL on the downstream side in the transport direction to the area of the cutting position CL on the upstream side. , Placed intermittently. In the portion B after the sheet member welding step, as shown in FIG. 6B, the sheet welding portion j has a substantially square shape, and a space is provided between the sheet welding portion j adjacent in the conveyance direction and in the conveyance direction. A plurality of welding rows L aligned along the CD direction are arranged.

  As can be seen from the cross-sectional structure shown in FIG. 7B, the skin side sheet 31 and the non-skin side sheet 32 are integrated by welding and bonding the skin side sheet 31 and the non-skin side sheet 32. Also in the sheet member welding step, the thread rubber 35 is conveyed in a stretched state, and is thinner than the thread rubber 35 in the natural state. Further, the sheet members 31 and 32 are conveyed in a state in which an appropriate tension is applied.

  The plurality of sheet welded portions j not only join the skin side sheets 31 and 41 and the non-skin side sheets 32 and 42, respectively, but also play a role of attaching the rubber threads 35 and 45. The spacing (predetermined spacing) Dj (see FIG. 8) of the sheet welds j located on both sides in the CD direction across the rubber thread 35 (see FIG. 8) is in an extended state at a first processing position PK1 at a predetermined spacing The size of the rubber thread 35 in the CD direction is larger than the size of the rubber thread 35 in the non-loaded state, which is a natural length. As a result, when the rubber thread 35 is brought closer to the natural state, the thickness of the rubber thread 35 is increased, and the sheet welds j can suppress the rubber thread 35 by narrow pressure from the vertical direction. Thus, by fixing the rubber thread 35 to the sheet welding portion j using expansion and contraction, the amount of the adhesive for fixing the rubber thread 35 can be reduced or no adhesive can be used. Therefore, the ventral-side member 30 can be softened to improve the touch.

  The sheet welding portion j can be formed using an ultrasonic welding device (not shown). The ultrasonic welding apparatus has, for example, a horn having a vibrating surface that vibrates in the normal direction, and an anvil roll that rotates along the transport direction, and the anvil roll has each side welding portion SS to receive this vibrating surface. It has a convex part corresponding to the outer peripheral surface.

  Next, in the fifth processing position PK5, the absorbent main body disposing step (S505) is performed. In the absorbent main body disposing step, the single-plate absorbent main body 10 formed in another step (not shown) is bridged and fixed between the ventral side member 30 and the back side member 40. When the absorbent main body 10 is fixed, it becomes a continuous body of the substantially ladder-like diaper 1 together with the ventral side member 30 and the back side member 40. The disposition of the absorbent main body 10 can be performed, for example, using a rotating drum device (not shown). The rotary drum device has a rotary drum that rotates along the transport direction, and the rotary drum has a plurality of holding portions that detachably hold the absorbent main body 10 on the outer peripheral surface. In the absorbent main body disposing step, the rubber thread 35 is conveyed in a stretched state, and the sheet members 31 and 32 are conveyed in a state in which an appropriate tension is applied.

  Then, the overlapping step (S506) is performed at the sixth processing position PK6. In the superposition step, the absorbent main body 10 is folded in two at a predetermined position CL1 (see FIG. 2A) of the absorbent main body 10 in the CD direction. As a result, the abdominal side sheet 31 and the non-skin side sheet 32 of the abdominal side member 30, and the skin side sheet 41 and the non-skin side sheet 42 of the back side member 40 are stacked in the thickness direction. In the overlapping step, the rubber thread 35 is conveyed in a stretched state, and the sheet members 31 and 32 are conveyed in a state where an appropriate tension is applied.

  The stacking step can be performed, for example, using a bending guide device (stacking unit) (not shown). The bending guide device has a guide plate and a guide roller arranged at a predetermined position in the transport direction. And a guide plate and a guide roller guide the continuous body of the substantially ladder-like diaper 1 which passes the arrangement | positioning position so that it may become a 2-fold shape.

  Subsequently, the relaxation step (S507) is performed at the seventh processing position PK7. The relaxation step is a step of loosening the stretched state of the thread rubbers 35 and 45 so as to relax the stretched state. Part C (FIG. 6C) shows the state after the relaxation process. The relaxed state in which the elongation of the thread rubbers 35 and 45 is relaxed means the state between the extension state and the natural state of the thread rubber 35, and in the present embodiment, the extension in the thread rubber arranging step (S302, 402) The state of being shrunk to be 50% to 70% of the length of the rubber thread 35, 45 in the state. The alleviation process can be performed using, for example, a variable-speed conveyance device (alleviation unit) including a conveyance roller (not shown) or the like. The variable speed conveying device includes a plurality of conveying rollers, and in the seventh processing position PK7, the first roller conveys at a substantially constant speed from the non-skin side sheet member arrangement (S301) to the overlapping step (S506), In the area downstream of Part C, the sheet is conveyed using a second roller that is slower than the first roller. By adjusting the rotational speeds of the first roller and the second roller, it is possible to adjust the degree of relaxation of the rubber thread 35 and wrinkles formed on the skin side sheet 31 and the non-skin side sheet 32.

  FIG. 6C shows a portion C in a state in which the rubber thread 35, 45 is unstretched. As shown in FIG. 6C, by relaxing the elongation of the thread rubber 35, the thread rubber 35 contracts in the transport direction. In the present embodiment, the yarn rubber 35 is contracted to a length of 60% of the length of the rubber rubber 35 in the stretched state such as the yarn rubber disposing step (S302) and in a state of being stretched more than the natural state of the rubber rubber 35. is there. Thus, in the relaxation step and the subsequent steps, rather than stretching the thread rubber 35 to the natural state, the thread rubber 35 is in the stretched state in the thread rubber arranging step (S302) and the like and in the unloaded state. It is preferable to be relaxed so as to be in the state between them. When the rubber thread 35 is loosened to the natural state, positioning on the manufacturing line becomes difficult, and there is a possibility that the welding step (S508) and the cutting step (S509) described later can not be performed at the correct positions. Therefore, by appropriately stretching the rubber thread 35 and loosening it appropriately, processing to a more accurate position becomes possible in the downstream process.

  The region of the ventral-side member 30 shown in FIG. 6C is the same as the region shown in FIGS. 6A and 6B. That is, the pitch P1 shown in FIG. 6C is 60% longer than the pitch P1 in the thread rubber arranging step (S302) shown in FIG. 6A and the sheet member welding step (S304) shown in FIG. It will be. For convenience, in FIGS. 6A to 6D, the drawings are shown aligned on the right side (upstream side in the transport direction), and in FIGS. 6C and 6D, the diaper 1 is in a continuous state in the transport direction. The “downstream side in the transport direction” is omitted.

  At this time, the thread rubber 35 of the ventral-side member 30 becomes shorter in the transport direction than in the stretched state, and becomes thicker in the vertical direction and in the thickness direction. Furthermore, the sheet members 31 and 32 are in a loose state so that the skin side sheet 31 and the non-skin side sheet 32 except the sheet welded portion j are convex toward the skin side and the non-skin side. That is, in the skin side sheet 31 and the non-skin side sheet 32, at least one crease which is uneven in the vertical direction is formed between the sheet welded portions j adjacent in the transport direction, and in the area shown in FIG. A plurality of weirs are formed in the transport direction.

  As shown in FIG. 7C, when the wrinkles of the skin side sheet 31 and the non-skin side sheet 32 are formed by the relaxation of the elongation of the thread rubber 35, the fibers of the nonwoven fabric of the skin side sheet 31 and the non-skin side sheet 32 The basis weight (weight of nonwoven fabric per unit area) increases. That is, the amounts (weights) of the nonwoven fabric of the skin side sheet 31 and the non-skin side sheet 32 in FIG. 7B and the amounts (weights) of the nonwoven fabric of the skin side sheet 31 and the non-skin side sheet 32 in FIG. is there. However, after the relaxation process shown in FIG. 7C, the shrinkage of the rubber thread 35 makes the area smaller, so the amount of non-woven fabric per unit area increases.

  Thereafter, the side welding step (S508) is performed at the eighth processing position PK8. In the welding step, the skin side sheet 31 and the non-skin side sheet 32 of the belly side member 30 and the skin side sheet 41 and the non-skin side sheet 42 of the back side member 40 stacked in the thickness direction are performed in the relaxation step. In a state in which the elongation of the rubber threads 35 and 45 is relaxed, welding is performed at each of both sides of the cutting position CL to form a pair of side welded parts SS, SS. The ventral side member 30 and the back side member 40 are joined by forming the side welded portions SS, SS. The plurality of side welded portions SS have substantially the same shape, are rectangular shapes long in the left-right direction, and are intermittently arranged in the CD direction.

  The formation of the side welding portion SS can be performed, for example, using an ultrasonic welding device (welding portion) (not shown). The ultrasonic welding apparatus has, for example, a horn having a vibrating surface that vibrates in the normal direction, and an anvil roll that rotates along the transport direction, and the anvil roll has each side welding portion SS to receive this vibrating surface. It has a convex part corresponding to the outer peripheral surface.

  FIG. 6D shows a portion D in a state in which the side welds SS are formed in a state in which the rubber thread 35 is loosened. The side weld portion SS in FIG. 7D indicates a substantially half area on the belly side member 30 side in the thickness direction, and omits a substantially half area on the back side member 40 side. As shown in FIG. 6D, with the extension of the thread rubbers 35 and 45 shown in FIG. 6C relaxed, the downstream end of each of the ventral member 30 and the dorsal member 40 on both sides of the cutting position CL. A plurality of side welded parts SS are provided intermittently in the CD direction, which join the parts and the upstream end parts of the ventral side member 30 and the back side member 40, respectively.

  As shown in FIG. 7D, the wrinkles (FIG. 6C, FIG. 7C) having unevenness along the vertical direction formed in the relaxation process are skin side sheets 31 and 41, non-skin side sheets due to the formation of the side welds SS. 32 and 42 are crushed from the thickness direction and become substantially parallel to the transport direction. Since the side welding step is performed in a state in which expansion and contraction of the thread rubbers 35 and 45 are relaxed, the basis weight of each of the non-woven fabrics of the ventral side member 30 and the back side member 40 is reduced by the contraction of the thread rubbers 35 and 45. It will be in the state where it is more than the 35, 45 extension state. As a result, the belly side member 30 and the back side member 40 are relaxed in a relaxed state as compared with the case where the belly side member 30 and the back side member 40 are welded and joined in the stretched state of the thread rubber 35, 45 The welding strength is stronger in the case of welding and joining. This is because the welding is to melt the non-woven fabric and to bond the melted non-woven fabrics to each other. Therefore, the bonding strength improves as the content of the non-woven fabric increases. When the pants-type disposable diaper 1 shown in FIG. 1 is to be worn or during wearing, there is a fear that the lateral end portions (side ends 30a, 40a) of the ventral side member 30 and the back side member 40 may be torn. Can be reduced.

  Moreover, in order to improve the air permeability of the ventral side member 30 and the back side member 40, to lower the cost, or to improve the feel, the basis weight of the nonwoven fabric of the ventral side member 30 and the back side member 40 is respectively lowered. Even in this case, the welding strength between the ventral side member 30 and the back side member 40 can be improved. That is, in the relaxation step, the elongation of the rubber threads 35 and 45 is relaxed to form the side welded portion SS in a state in which the creases are formed on the ventral side member 30 and the back side member 40. Even when the basis weight of the non-woven fabric of the side member 40 is small, the basis weight of the non-woven fabric of the ventral-side member 30 and the back-side member 40 in the side welded portion SS can be increased by wrinkles, so the strength of the side welded portion SS Can be improved.

  Further, as shown in FIG. 8, it is preferable to form the side welds SS at positions overlapping the at least one sheet weld j in the thickness direction. Further, it is more preferable to form the side welds SS overlapping in the thickness direction on the two or more sheet welds j. As described above, by setting the thread rubbers 35 and 45 in the relaxed state, a crease is formed between the sheet welds j adjacent in the transport direction. When the side welds SS are formed on the at least one sheet weld j, the shape tends to crush at least a part of the crease between the sheet welds j. Further, by providing the side welds SS overlapping the two or more sheet welds j in the thickness direction, it is possible to more surely crush the crease between the sheet welds j. As a result, the basis weight of the non-woven fabric of the abdominal side member 30 and the back side member 40 in the side welded portion SS can be increased, and the welding strength of the side welded portion SS can be improved.

  As shown in FIG. 8, it is preferable that the distance Ds between the side welds SS adjacent in the vertical direction is longer than the distance Dj between the sheet welds j adjacent in the vertical direction (Ds> Dj). Since the thread rubbers 35 and 45 are located between the sheet welds j adjacent in the vertical direction, the interval Ds of the side welds SS adjacent in the vertical direction is the distance between the sheet welds j adjacent in the vertical direction The risk of cutting the rubber threads 35, 45 when forming the side welds SS can be reduced more than when the length is shorter than Dj.

  Further, it is preferable that the length Ws in the left-right direction of the side weld portion SS be longer than the length Wj in the left-right direction of the sheet weld portion j (Ws> Wj). When the length Ws in the left and right direction of the side welded portion SS is shorter than the length Wj in the left and right direction of the sheet welded portion j (Ws <Wj), the sheet welds j overlap only in the portion where the sheet welded portion j is provided. There is a risk that the side welds SS will be formed in the area. In this case, even if the elongation of the thread rubbers 35 and 45 is relaxed in the relaxation step, the side welded portion SS is difficult to weld so as to crush the wrinkles, so the basis weight of the nonwoven fabric in the side welded portion SS It will be difficult to increase the In this respect, when the length Ws in the left-right direction of the side weld portion SS is longer than the length Wj in the left-right direction of the sheet weld portion j (Ws> Wj), the sheet weld portion j is provided outside in the left-right direction. Since it becomes easy to crush a weir at the time of formation of side welding part SS, it becomes easy to make the basic weight of the nonwoven fabric in side welding part SS increase, and welding strength of side welding part SS can be improved.

  Further, it is preferable that the interval (Db) of the thread rubber 35 adjacent in the vertical direction is larger than the length (Hs) in the vertical direction of the side welded portion SS (Db> Hs). As shown in FIG. 8, when the intervals Db of the thread rubbers 35 adjacent to each other in the vertical direction are not equal, the portion with the smallest spacing Db of the thread rubbers 35 is the length in the vertical direction of the side welds SS ( More preferably, it is larger than Hs). This can further reduce the risk of cutting the rubber thread 35 when forming the side welds SS.

  Finally, the cutting step (S509) is performed at the ninth processing position PK9. In the cutting step, the diaper 1 in a continuous state in the transport direction is cut at the cutting position CL while the elongation of the thread rubbers 35 and 45 is relaxed, and the individual diapers 1 are formed. In the cutting step, the skin side sheets 31 and 41, the non-skin side sheets 32 and 42, and the rubber threads 35 and 45 in a continuous state in the transport direction are cut at the cutting position CL.

  As in the side welding step, the cutting step is preferably performed in a state in which the elongation of the rubber threads 35 and 45 performed in the relaxation step is relaxed. When the expansion of the thread rubbers 35 and 45 is relaxed, the thickness of the thread rubbers 35 and 45 is increased, and the thread rubbers 35 and 45 are narrowed in the CD direction between the sheet welds j and the side welds SS. It becomes easy to do. By cutting the ventral side member 30 and the back side member 40 including the thread rubbers 35 and 45 in a state of being fixed by the sheet weld portion j and the side weld portions SS, the thread rubbers 35 and 45 are cut in a stretched state As compared with the case, the sheet welded portion j makes it easier to maintain the state in which the rubber threads 35 and 45 are fixed. In addition, when the cutting process is performed in a state where the thread rubbers 35 and 45 are stretched, the thread rubbers 35 and 45 which are narrowed in the vertical direction and the front and back direction immediately after cutting tend to shrink by a strong force. The thread rubbers 34 and 45 fixed by the SS and the sheet welded portion j may come out of the fixing by the side welded portion SS and the sheet welded portion j. In this respect, by performing the cutting process in a state in which the elongation of the thread rubbers 35 and 45 is relaxed, the force for the thread rubbers 35 and 45 to shrink can be reduced, and the thread rubbers 35 of the individual diapers 1 It is possible to reduce the possibility of the fixing member 45 coming out of the fixed state by the side welding part SS and the sheet welding part j.

  The cutting process can be performed using, for example, a cutter device (cutting unit) not shown. The cutter device has a pair of rolls that rotate along the transport direction. And one roll is a cutter roll which has a cutter blade in an outer peripheral surface, and the other roll is an anvil roll which receives a cutter blade in an outer peripheral surface.

  In the cross-sectional views shown in FIGS. 7B, 7C, and 7D, the sheet welded portion j and the side welded portion SS are each represented by a rectangular shape, but in actuality, the welded region changes gently. It does not become a shape, and it becomes vague about the boundary.

=== Other Embodiments ===
As mentioned above, although embodiment of this invention was described, said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. Further, it goes without saying that the present invention can be modified or improved without departing from the gist thereof, and that the present invention includes equivalents thereof. For example, the following modifications are possible.

  In the embodiment described above, the relaxation step (S507) is provided before the side welded portion SS for welding and joining the ventral side member 30 having the thread rubber 35 and the back side member 40 having the thread rubber 45; Although the side welding process (S508) was performed in the state which relieve | moderated 45, it is not restricted to this. The present invention may be applied to bonding of one member (first member) having an elastic member to the other member (second member) not having an elastic member.

  FIG. 9 is a diagram for explaining another embodiment. The disposable diaper 100 shown in FIG. 9 is a tape-type diaper, and has an exterior sheet 101 and an absorber 102, and on the outer side in the left-right direction of the exterior sheet 101, at one end in the longitudinal direction A side panel 103 including an elastic member is provided, and hook members 104 are provided on the outer sides of the side panel 103 in the left-right direction. The side panel 103 and the hook member 104 each include non-woven fabric. The present invention can be applied to the step of joining the hook member 104 to the side panel 103 in the manufacturing process of the diaper 100. Specifically, before welding the hook member 104 to the side panel 103, the extended elastic member of the side panel 103 may be in a relaxed state, and the side panel 103 and the hook member 104 may be welded and joined in the relaxed state. By doing this, the bonding between the side panel 103 and the hook member 104 can be further strengthened, and when the protector or the like tries to make the baby wear the diaper 100 or the baby wears the diaper 100. At the same time, the risk of the hook member 104 peeling off from the side panel 103 can be further reduced.

  In addition, in the above-mentioned embodiment, although the elastic member with which the abdominal side member 30 and the back side member 40 are equipped and illustrated as rubber thread (35, 45) and illustrated, it does not restrict to this. Instead of the thread rubber, one or more sheet-like elastic members such as, for example, an elastic film or an elastic nonwoven fabric may be provided.

  Furthermore, in the above-mentioned embodiment, although seal welding part j and side welding part SS carried out ultrasonic bonding using an ultrasonic seal device, it is not restricted to this. Other welding methods may be used. For example, a heat sealing apparatus having a pair of heated rolls may be used.

  The seal weld j and the side welds SS do not necessarily have to be rectangular. Each shape is not limited to the rectangular shape, and any shape such as an elliptical shape, a circular shape, a parallelogram shape, etc. can be adopted.

  Also for the side welds SS, the plurality of side welds SS may not necessarily be arranged intermittently in the vertical direction. For example, the side welding parts SS provided from the upper end to the lower end of the end part in the left-right direction of the diaper 1 may be provided on both side parts one by one.

1 diapers (pants-type disposable diapers, absorbent articles),
10 Absorbent body, 10ea end, 10eb end,
11 absorber, 11c absorbent core,
13 top sheets, 15 back sheets,
30 ventral member (first member), 30a side (end),
31 skin side sheet member (first sheet member),
32 Non-skin side sheet member (first sheet member),
35 thread rubber (elastic member, first elastic member),
40 back member (second member), 40a side (end),
41 skin side sheet member (second sheet member),
42 Non-skin side sheet member (second sheet member),
45 thread rubber (elastic member, second elastic member),
100 diapers (tape-type disposable diapers, absorbent articles),
101 exterior sheet, 102 absorber, 103 side panel, 104 hook member,
j sheet welding part L1, L2 welding row,
P1 pitch, BL boundary position, CL cutting position,
SS side welds,
LH leg opening, BH trunk opening

Claims (11)

A welded portion in which two sheet members provided with at least one non-woven fabric and a first member provided with an elastic member expandable in the left-right direction, a second member provided with non-woven fabric, and the first and second members A method of manufacturing an absorbent article having
An elastic member disposing step of disposing the elastic member in an extended state extended in the left-right direction between two sheet members in a thickness direction intersecting the left-right direction of the first member;
An overlapping step of overlapping the second member in the thickness direction of the first member;
A relaxation process for relieving the stretched state into a relaxed state;
And welding the one end portion of the first member in the left-right direction and the one end portion of the second member in the left-right direction to form the welded portion.
The manufacturing method of the absorbent article characterized by performing the said welding process in the said relaxation state after the said relaxation process. In the method of manufacturing an absorbent article according to claim 1,
In the relaxation step,
Relieving the resilient member to a state between the stretched state and the natural state;
An absorbent article, wherein the sheet member is in a state in which a plurality of creases are formed in the left-right direction. In the manufacturing method of the absorptive article according to claim 1 or 2,
The sheet member is a first sheet member,
The elastic member is a first elastic member,
A method of manufacturing an absorbent article, wherein the second member comprises two second sheet members provided with at least one non-woven fabric, and a second elastic member that can expand and contract in the left-right direction. In the method of manufacturing an absorbent article according to claim 3,
And a sheet welding step of forming a sheet welding portion for welding the first sheet members together,
Performing the sheet welding step after the elastic member disposing step and before the overlapping step;
In the sheet welding step,
The sheet welding portion is intermittently arranged from one end to the other end of the first sheet member in the left-right direction to form a welding row along the left-right direction,
The welding rows are formed in at least two rows at predetermined intervals in the vertical direction intersecting with the left and right direction,
The first elastic member is provided between the welding rows adjacent in the vertical direction,
The method for manufacturing an absorbent article, wherein the predetermined interval is longer than the thickness of the first elastic member in the stretched state and shorter than the thickness of the first elastic member in the natural state. In the method of manufacturing an absorbent article according to claim 4,
In the elastic member disposing step, the sheet welding step, the overlapping step, the relaxation step, and the welding step, the first member is continuous in the left-right direction,
After said welding step, by cutting the first member of the continuous state, has a cutting step of forming the first member of the disconnected state,
The manufacturing method of the absorbent article characterized by performing the said cutting process in the state which relaxed the said expansion | extension state. In the method of manufacturing an absorbent article according to claim 4 or 5,
In the welding step, the welded portion is formed at a position overlapping the at least one sheet welded portion in the thickness direction. In the method of manufacturing an absorbent article according to claim 6,
In the welding step, the welded portion is formed at a position overlapping with the two or more sheet welded portions in the thickness direction. In the method of manufacturing an absorbent article according to any one of claims 4 to 7,
The plurality of welds are arranged along the vertical direction,
A method of manufacturing an absorbent article, wherein an interval between the welds adjacent in the vertical direction is longer than the predetermined interval. In the method of manufacturing an absorbent article according to any one of claims 4 to 8,
A method of manufacturing an absorbent article, wherein the length in the left-right direction of the welded portion is longer than the length in the left-right direction of the sheet welded portion. In the method of manufacturing an absorbent article according to any one of claims 4 to 9,
A plurality of first elastic members are provided,
The plurality of welds are arranged along the vertical direction,
The space | interval of said 1st elastic member adjacent to the said up-down direction is larger than the length of the said up-down direction of the said welding part, The manufacturing method of the absorbent article characterized by the above-mentioned. Welded portion formed by welding two sheet members provided with at least one non-woven fabric and a first member provided with an elastic member expandable in the left-right direction, a second member provided with non-woven fabric, and the first and second members An apparatus for manufacturing an absorbent article having
An elastic member arranging portion for arranging the elastic member in an expanded state extended in the left-right direction between two sheet members in a thickness direction intersecting the left-right direction of the first member;
An overlapping portion for overlapping the second member in the thickness direction of the first member;
A relief unit for relaxing the extended state to a relaxed state;
The welding formation part which welds the one end of the above-mentioned horizontal direction of the 1st member, and the one end of the above-mentioned horizontal direction of the 2nd member, and forms the welding part,
An apparatus for manufacturing an absorbent article, wherein the welded portion is formed in the relaxed state in the welding formation portion after the extension of the elongated state is relaxed in the relaxation portion.

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