CN108938212B - Method and apparatus for manufacturing sheet-like member for absorbent article - Google Patents

Abstract

A method for manufacturing a sheet member relating to an absorbent article includes the steps of: conveying the composite sheet fixed by the thermoplastic adhesive in a conveying direction; the composite sheet is arranged in the conveyance direction by cutting the elastic member at least one portion in the conveyance direction in a region corresponding to the low stretch region, thereby forming a high stretch region and a low stretch region. In the step of forming the high and low expansion and contraction regions, the heating member heats the rotating body of at least one of the cutting rotating body and the anvil rotating body such that the temperature of the rotating body is less than the melting point of the adhesive, the cutting rotating body and the anvil rotating body rotate with the outer circumferential surfaces of each other facing each other and the cutting blade and the anvil rotating body of the outer circumferential surface of the cutting rotating body nip the composite sheet while the composite sheet passes between the cutting rotating body and the anvil rotating body in the conveying direction, thereby forming a nip portion of the first continuous sheet and the second continuous sheet at the nip-pressed position of the composite sheet and cutting the elastic member.

Description

Method and apparatus for manufacturing sheet-like member for absorbent article

The present application is a divisional application of an invention patent application entitled "method and apparatus for manufacturing a sheet member relating to an absorbent article", having an international application date of 2014-11-6, an international application number of PCT/JP2014/079417, and a national application number of 201480083184.0.

Technical Field

The present invention relates to a method and an apparatus for manufacturing a sheet member for an absorbent article such as a disposable diaper.

Background

Conventionally, in the manufacture of disposable diapers known as absorbent articles for absorbing excretory fluids such as urine, sheet members having a high stretch region and a low stretch region are used, the high stretch region being aligned in a predetermined direction, and the low stretch region having a lower stretch property in the predetermined direction than the high stretch region.

The sheet member 20s' is produced as follows. Fig. 1 is a schematic view showing a production process thereof in a plan view.

First, as shown in fig. 1, the composite sheet 20s1 'as a material of the sheet member 20s' is conveyed in the MD direction. Here, composite sheet 20s1' is a composite sheet as follows: a continuous body 27s ', 27s' … … of elastic strands (elastic strands) as elastic members continuous in the MD direction is interposed in an elongated state in the MD direction between a first continuous sheet 21s 'continuous in the MD direction and a second continuous sheet 22s' continuous in the MD direction. The continuous body 27s ', 27s' … … of the elastic thread is intermittently fixed to each of the continuous pieces 21s ', 22s' in the MD direction. That is, the continuous body 27s ', 27s' … … of the elastic thread is fixed by a hot melt adhesive, which is an example of a thermoplastic adhesive, in the region AH1 'corresponding to the high stretch region AH', but is not fixed in the region AL1 'corresponding to the low stretch region AL'.

When the composite sheet 20s1 'passes through the cutter device 50', the region AL1 'corresponding to the low stretch region AL' in the composite sheet 20s1 'is nipped by the cutter blade (not shown) of the cutter roll and the anvil roll (not shown) of the cutter device 50', and the continuous body 27s ', 27s' … … of the elastic thread is cut at one location PC in the MD direction. Then, the cut elastic threads 27sd ' and 27sd ' … … contract toward the regions AH1' and AH1' corresponding to the high stretch regions AH ' and AH ', respectively, whereby the high stretch regions AH ' and the low stretch regions AL ' are aligned in the MD direction and formed in the composite sheet 20s1 '. In addition, the sheet member 20s' is produced by the above processing.

Prior art documents

Patent document

Patent document 1: japanese Kohyo 2014-511753

Problems to be solved by the invention

Here, from the viewpoint of suppressing damage to the sheet member 20s ', it is preferable that only the continuous body 27s', 27s '… … of the elastic cord is cut at the pinched position PC1, and the first and second continuous pieces 21s', 22s 'of the composite sheet 20s1' are not cut as much as possible, and in the case described above, the pressure-bonded section j of the first continuous piece 21s 'and the second continuous piece 22s' is formed at the pinched position PC 1.

However, patent document 1 does not disclose that the pressure-bonding section j is formed at the position PC 1.

Further, patent document 1 also does not disclose a measure for suppressing the cutting damage of the continuous body 27s' of the elastic thread. As one of the countermeasures, the following countermeasures can be considered: by heating the cutting roll or the anvil roll, softening of the thermoplastic first and second continuous sheets 21s ', 22s ' is promoted during nipping, and thus the nipping force, which is the force during nipping, can be easily applied to the continuous body 27' of the elastic thread.

However, if these rollers are heated excessively, a large amount of heat may be transferred from the rollers to the composite sheet 20s1' when the composite sheet 20s1' passing through the apparatus comes into contact with the rollers, and the hot melt adhesive in the sheet 20s1' may melt. Then, when the adhesive agent adheres to and accumulates on the roll with high fluidity in its molten state, and the adhesive substance falls down on the composite sheet 20s1 'after the accumulation continues to form a large lump, and is involved therein, the diaper in which the adhesive substance is involved in the portion of the composite sheet 20s1' becomes a defective product. Therefore, a technique capable of suppressing the adhesion of the adhesive to the roller is desired.

Disclosure of Invention

The present invention has been made in view of the above-described conventional problems, and an object thereof is to: when the composite sheet is cut into an elastic member such as a continuous body of elastic threads and the like, and at the same time, a pressure-bonded portion of the thermoplastic first continuous sheet and the thermoplastic second continuous sheet is formed at the position, it is possible to effectively prevent the thermoplastic adhesive from the composite sheet from adhering to the cutting rotator or the anvil rotator while suppressing the cutting damage of the elastic member.

Means for solving the problems

A main aspect of the present invention for achieving the above object is a method for manufacturing a sheet member for an absorbent article, the sheet member having a high stretch region and a low stretch region aligned in a predetermined direction, the low stretch region having a lower stretch degree than the high stretch region in the predetermined direction, the method comprising:

conveying a composite sheet, in which an elastic member continuous in the predetermined direction is interposed in an extended state in the predetermined direction between a first continuous thermoplastic sheet continuous in the predetermined direction and a second continuous thermoplastic sheet continuous in the predetermined direction, while the elastic member is fixed by a thermoplastic adhesive at least in a region corresponding to the high stretch region, by using the predetermined direction as a conveying direction;

forming the high stretch region and the low stretch region by cutting the elastic member at least one location in the conveyance direction in a region corresponding to the low stretch region, thereby aligning the composite sheet in the conveyance direction;

in the step of forming the high expansion and contraction region and the low expansion and contraction region, a heating member heats a rotating body of at least one of a cutting rotating body and an anvil rotating body such that a temperature of the rotating body is less than a melting point of the adhesive, the cutting rotating body and the anvil rotating body rotate with outer circumferential surfaces thereof facing each other, and a cutting knife of the outer circumferential surface of the cutting rotating body and the anvil rotating body nip the composite sheet when the composite sheet passes between the cutting rotating body and the anvil rotating body in the conveying direction, thereby forming a nip portion of the first continuous sheet and the second continuous sheet at a nip position of the composite sheet and cutting the elastic member,

the rotating body heated by the heating member is both the cutting rotating body and the anvil rotating body.

Further, the present invention relates to an apparatus for manufacturing a sheet member for an absorbent article, the sheet member having a high stretch region and a low stretch region aligned in a predetermined direction, the low stretch region having a lower stretch degree than the high stretch region in the predetermined direction, the apparatus comprising:

a conveying device that conveys a composite sheet, which is configured such that an elastic member continuous in the predetermined direction is interposed in an extended state in the predetermined direction between a first continuous sheet continuous in the predetermined direction and a second continuous sheet continuous in the predetermined direction, and the elastic member is fixed with a thermoplastic adhesive at least in a region corresponding to the high stretch region, the composite sheet being conveyed in the predetermined direction as a conveying direction; and

a cutting device that forms the high stretch region and the low stretch region by cutting the elastic member at least one location in the conveyance direction in a region corresponding to the low stretch region, thereby aligning the composite sheet in the conveyance direction;

the cutting device includes a cutting rotor, an anvil rotor, and a heating member, wherein the cutting rotor and the anvil rotor rotate so that outer circumferential surfaces thereof face each other, the heating member heats at least one of the cutting rotor and the anvil rotor so that a temperature of the rotor is less than a melting point of the adhesive,

a cutting knife of an outer peripheral surface of the cutting rotary body and the anvil rotary body nip the composite sheet while the composite sheet passes between the cutting rotary body and the anvil rotary body along the conveying direction, thereby forming a nip portion of the first continuous sheet and the second continuous sheet at a position of the composite sheet being nipped and cutting off the elastic member,

the rotating body heated by the heating member is both the cutting rotating body and the anvil rotating body.

Other features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, when an elastic member such as a continuous body of an elastic thread is cut in a composite sheet and a pressure-bonded portion of a thermoplastic first continuous sheet and a thermoplastic second continuous sheet is formed at the position, it is possible to effectively prevent a thermoplastic adhesive from the composite sheet from adhering to a cutting rotator or an anvil rotator while suppressing cutting damage of the elastic member.

Drawings

Fig. 1 is a schematic plan view showing a process of producing a sheet member 20s ' having a high stretch region AH ' and a low stretch region AL '.

Fig. 2 is a schematic perspective view of a 3-piece type disposable diaper 1 as an example of the absorbent article of the present embodiment.

Fig. 3 is a schematic plan view of the diaper 1 in an unfolded state as viewed from the skin side.

Fig. 4 is a schematic plan view of the diaper 1 viewed from the non-skin side.

Fig. 5A is a sectional view a-a in fig. 3, and fig. 5B is a sectional view B-B in fig. 3.

Fig. 6 is a cross-sectional view VI-VI in fig. 3.

Fig. 7 is a schematic plan view of the abdominal-side band member 20a as viewed from the non-skin side.

Fig. 8 is a schematic plan view of the abdominal-side belt member 20a before the elastic thread 27s is cut, as viewed from the non-skin side.

Fig. 9A is a schematic plan view of the sheet member 20as before being conveyed to the manufacturing apparatus 30 of the present embodiment, and fig. 9B is a schematic plan view of the sheet member 20as in which the extensible regions AH, AH and the non-extensible region AL are formed by the manufacturing apparatus 30.

Fig. 10A is a schematic side view of the manufacturing apparatus 30, and fig. 10B is a view taken along line B-B in fig. 10A.

Fig. 11 is an explanatory diagram of the arrangement state of the cutter blades C, C … … provided on the cutter block 54 of the cutter roller 51d, and is a diagram showing the outer peripheral surface 51da of the roller 51d spread out on a plane.

Fig. 12 is a schematic enlarged side view showing a gap G formed between the cutting edge of the cutter blade C and the outer peripheral surface 51ua of the anvil roll 51 u.

Fig. 13A is a schematic longitudinal sectional view of the cutter roller 51d and the anvil roller 51u for explaining the heating mechanism, and fig. 13B is a sectional view B-B in fig. 13A.

Fig. 14A is a schematic side view showing a state where a hot melt adhesive is applied to the continuous body 27s of the elastic thread, and fig. 14B is a view taken along direction B-B in fig. 14A.

Fig. 15 is a schematic side view showing a state where the sheet member 20as is wound around the cutter roller 51 d.

Fig. 16A and 16B are explanatory diagrams of an example in which the continuous body 27s of each elastic thread is cut at a plurality of positions PC and PC … … in the rotation direction Dc51d in the region AL1 corresponding to the non-stretch region AL.

Detailed Description

At least the following matters will become apparent from the description of the present specification and the accompanying drawings.

A method for manufacturing a sheet member for an absorbent article, the sheet member having a high stretch region and a low stretch region which are aligned in a predetermined direction, the low stretch region having a lower stretch in the predetermined direction than the high stretch region, the method comprising: conveying a composite sheet, in which an elastic member continuous in the predetermined direction is interposed in an extended state in the predetermined direction between a first continuous thermoplastic sheet continuous in the predetermined direction and a second continuous thermoplastic sheet continuous in the predetermined direction, while the elastic member is fixed by a thermoplastic adhesive at least in a region corresponding to the high stretch region, by using the predetermined direction as a conveying direction; forming the high stretch region and the low stretch region by cutting the elastic member at least one location in the conveyance direction in a region corresponding to the low stretch region, thereby aligning the composite sheet in the conveyance direction; in the step of forming the high expansion and contraction region and the low expansion and contraction region, a heating member heats a rotating body of at least one of a cutting rotating body and an anvil rotating body such that a temperature of the rotating body is less than a melting point of the adhesive, the cutting rotating body and the anvil rotating body rotate with outer circumferential surfaces thereof facing each other, and a cutting knife of the outer circumferential surface of the cutting rotating body and the anvil rotating body nip the composite sheet when the composite sheet passes between the cutting rotating body and the anvil rotating body in the conveying direction, thereby forming a nip portion of the first continuous sheet and the second continuous sheet at a nip position of the composite sheet and cutting the elastic member.

According to the method of manufacturing a sheet member for an absorbent article, the heating member heats the rotating body of at least one of the cutting rotating body and the anvil rotating body so that the temperature of the rotating body is less than the melting point of the adhesive. Therefore, softening of the thermoplastic first and second continuous sheets can be promoted by the heating, and the force at the time of nipping, that is, the nipping force can be easily applied to the continuous body of the elastic member, whereby the cutting damage of the elastic member can be suppressed.

Further, by heating the rotary body limited to a temperature less than the melting point as described above, the hot melt adhesive in the composite sheet can be substantially prevented from being melted by heat input caused by contact between the rotary body and the composite sheet. Therefore, the adhesive can be effectively prevented from adhering from the composite sheet to the rotary body.

In the method for producing a sheet member relating to the absorbent article, the adhesive is preferably applied to the elastic member.

According to such a method for producing a sheet member for an absorbent article, the adhesive is applied to an elastic member. Therefore, the elastic member can be fixed by a relatively small amount as compared with the case of applying the elastic member to the first and second continuous sheets. That is, the amount of adhesive remaining in the composite sheet without contributing to the fixation of the elastic member can be greatly reduced. As a result, the composite sheet can be prevented from being hardened, which may occur when the coating amount is too large, and the flexibility of the composite sheet can be easily ensured.

In the method of manufacturing a sheet member relating to the absorbent article, it is preferable that the rotating body heated by the heating member is the cutting rotating body.

According to the method of manufacturing a sheet member relating to an absorbent article, since the heat of heating is also rapidly transmitted to the cutter, the heat can effectively promote softening of the first and second continuous sheets at the position where the first and second continuous sheets abut against the cutter. This makes it possible to easily apply the clamping force to the elastic member at the position, and as a result, the cutting property of the elastic member can be improved. Further, since the temperature of the dicing blade is not high enough for the melting point, the adhesive is prevented from melting, and the adhesive is prevented from adhering to the dicing blade, so that the cutting performance of the dicing blade can be maintained in a good state for a long period of time.

In the method of manufacturing a sheet member relating to the absorbent article, it is preferable that the rotating body heated by the heating member rotates about a rotation axis along a CD direction intersecting the conveyance direction, and the heating member heats the rotating body in a predetermined heating pattern so that a temperature difference in the CD direction of the rotating body is reduced.

According to the method of manufacturing a sheet member relating to an absorbent article, the temperature difference in the CD direction of the rotating body is reduced. Therefore, the deviation of the gap size between the cutting blade and the anvil rotating body can be reduced in the CD direction, whereby the formation accuracy of the crimping portion can be improved.

In the method of manufacturing a sheet member relating to the absorbent article, it is preferable that the heating pattern is defined by an amount of heat (W/m) input per second per unit length in the CD direction, and the heating member inputs more heat (W/m) to an end portion of the rotating body in the CD direction than to a central portion of the rotating body in the CD direction based on the heating pattern.

According to the method of manufacturing a sheet member relating to an absorbent article, when the temperature of the end portion is lower than the temperature of the central portion in the CD direction, the temperature difference in the CD direction of the rotating body can be reduced.

In the method of manufacturing a sheet member relating to the absorbent article, it is preferable that the cutter is provided on the outer peripheral surface of the cutter rotor via a cutting block, a temperature sensor for measuring a temperature of the cutter rotor is provided in a region where the cutting block is located in the CD direction, and a heating amount of the cutter rotor is adjusted based on a measured value of the temperature sensor.

According to the method of manufacturing a sheet member for an absorbent article, the temperature of the portion close to the cutter blade is measured, and the amount of heating of the cutter rotor is adjusted based on the measured temperature. Therefore, the adhesive can be more effectively prevented from adhering to the cutter blade.

In the method of manufacturing a sheet member relating to the absorbent article, it is preferable that the rotating body heated by the heating member is both the cutting rotating body and the anvil rotating body.

According to the method for manufacturing a sheet-like member relating to an absorbent article, adhesion of the adhesive to both the cutting rotor and the anvil rotor is effectively prevented, and the cutting property of the elastic member can be improved by the heating.

In the method for manufacturing a sheet member relating to the absorbent article, it is preferable that the composite sheet is wound around the rotating body heated by the heating member.

According to the method for manufacturing a sheet member for an absorbent article, the composite sheet can be stably conveyed by winding the sheet member around the rotating body, and as a result, the elastic member can be more effectively prevented from being cut and damaged. In this case, the heating of the rotating body is also maintained at a temperature less than the melting point of the adhesive, and the adhesive is effectively prevented from adhering to the rotating body.

In the method for manufacturing a sheet member relating to the absorbent article, it is preferable that the composite sheet has a lubricant.

According to the method for manufacturing a sheet member relating to an absorbent article, since the composite sheet has a lubricant, the lubricant can quickly perform a lubricating action when the sheet member is nipped by a cutter blade. Thus, the cutter blade performs pressure bonding without cutting the first and second continuous sheets related to the composite sheet, and selectively cuts the elastic member easily.

Further, an apparatus for manufacturing a sheet member for an absorbent article, the sheet member having a high stretch region and a low stretch region which are aligned in a predetermined direction, the low stretch region having a lower stretch in the predetermined direction than the high stretch region, the apparatus comprising: a conveying device that conveys a composite sheet, which is configured such that an elastic member continuous in the predetermined direction is interposed in an extended state in the predetermined direction between a first continuous sheet continuous in the predetermined direction and a second continuous sheet continuous in the predetermined direction, and the elastic member is fixed with a thermoplastic adhesive at least in a region corresponding to the high stretch region, the composite sheet being conveyed in the predetermined direction as a conveying direction; and a cutting device that forms the high stretch region and the low stretch region by cutting the elastic member at least one location in the conveyance direction in a region corresponding to the low stretch region, thereby aligning the composite sheet in the conveyance direction; the cutting device has a cutting rotating body, an anvil rotating body, and a heating member, the cutting rotating body and the anvil rotating body rotate in a manner that outer peripheral surfaces of each other face each other, the heating member heats a rotating body of at least one of the cutting rotating body and the anvil rotating body so that a temperature of the rotating body is less than a melting point of the adhesive, and when the composite sheet passes between the cutting rotating body and the anvil rotating body along the conveying direction, a cutting knife of the outer peripheral surface of the cutting rotating body and the anvil rotating body nip the composite sheet, thereby forming a pressure-bonding portion of the first continuous sheet and the second continuous sheet at a nip-pressed position of the composite sheet and cutting off the elastic member.

According to the apparatus for manufacturing a sheet-like member relating to an absorbent article, the same effects as those in the case of the above-described manufacturing method can be obtained.

In this embodiment, the present invention is not limited to the embodiment

The method and apparatus 30 for manufacturing the sheet member 20as relating to the absorbent article according to the present embodiment are used, for example, in a production line of a disposable diaper 1 as an example of the absorbent article. Fig. 2 is a schematic perspective view of a 3-piece type disposable diaper 1 as an example of the disposable diaper 1. Fig. 3 is a schematic plan view of the diaper 1 in an unfolded state as viewed from the skin side, and fig. 4 is a schematic plan view of the diaper 1 as viewed from the non-skin side. Fig. 5A is a sectional view taken along line a-a in fig. 3, fig. 5B is a sectional view taken along line B-B in fig. 3, and fig. 6 is a sectional view taken along line VI-VI in fig. 3.

As shown in fig. 3, 5A, and 6, the diaper 1 has three directions orthogonal to each other, namely, a longitudinal direction, a transverse direction, and a thickness direction. Since the diaper 1 is a so-called 3-piece diaper, it has an absorbent main body 10 which is attached to the crotch of a wearer to absorb excrement such as urine as a first member, an abdominal belt member 20a which covers the waist of the wearer from the abdominal side as a second member, and a back belt member 20b which covers the waist of the wearer from the back side as a third member.

In the developed state of fig. 3, the absorbent main body 10 is stretched between the abdominal belt member 20a and the back belt member 20b in a state where the abdominal belt member 20a and the back belt member 20b are arranged in parallel with a gap therebetween, and the ends 10ea and 10eb in the longitudinal direction of the absorbent main body 10 are joined and fixed to the nearest belt members 20a and 20b, respectively, and the external shape thereof is substantially H-shaped in plan view. In this state, the diaper 1 is folded in two with the substantially central portion CL10 in the longitudinal direction of the absorbent main body 10 being a folded position, and when the belt members 20a, 20b facing each other are joined to each other by welding or the like at the portions 20ae, 20be to be brought into contact with the side abdomen of the wearer (i.e., the respective end portions 20ae, 20be in the lateral direction) in this folded state, the belt members 20a, 20b are connected to each other in a loop shape, whereby the pants-type diaper 1 having the waist-opening 1HB and the pair of leg-opening 1HL, 1HL formed therein as shown in fig. 2 is obtained.

The absorbent main body 10 has: an absorbent core 11; a liquid-permeable top sheet 13 covering the core 11 from the skin side and constituting the skin-side surface of the absorbent main body 10; and a liquid-impermeable back sheet 15 covering the core 11 from the non-skin side to constitute the non-skin side surface of the absorbent main body 10. The absorbent core 11 is an absorbent core obtained by molding a liquid-absorbent material such as pulp fiber and a super absorbent polymer, which are examples of liquid-absorbent fibers, into a predetermined shape such as a substantially hourglass shape in plan view. In this example, the core 11 is covered with the liquid-permeable covering sheet 12, and the back sheet 15 has a two-layer structure including a nonwoven fabric 15nw and a resin film 15 f.

As shown in fig. 3 and 5B, the absorbent main body 10 may have three-dimensional gathers LSG, LSG as leakage-preventing walls at each end in the lateral direction for the purpose of preventing lateral leakage, and elastic members 17r such as elastic threads may be disposed at both lateral side portions of the absorbent main body 10, whereby stretchable leg gathers LG, LG may be formed at portions corresponding to the leg openings 1HL, 1HL of the diaper 1, as shown in fig. 2.

On the other hand, as shown in fig. 3 and 4, each of the abdominal-side belt member 20a and the back-side belt member 20b is a sheet-like member having a substantially rectangular shape in a plan view, which is long in the lateral direction, and has an outer layer sheet 21 and an inner layer sheet 22 laminated in the thickness direction as shown in fig. 5A and 6. The inner layer sheet 22 is positioned on the skin side in the thickness direction of the outer layer sheet 21. In addition, both the sheets 21 and 22 are formed of a soft thermoplastic sheet such as a nonwoven fabric, and in this example, a spunbond nonwoven fabric is used. However, the present invention is not limited to the above examples, and may be other types of nonwoven fabrics, resin films, woven fabrics, and the like. In this example, a single fiber of polypropylene (PP) is used as the structural fiber of the nonwoven fabric, but the present invention is not limited to the above examples, and a single fiber of another thermoplastic resin such as Polyethylene (PE) may be used, and a composite fiber such as a core-sheath structure of PE and PP may be used.

The transverse central regions 20ac, 20bc of the belt members 20a, 20b are joined to overlap the non-skin-side surfaces of the longitudinal end portions 10ea, 10eb of the absorbent body 10.

Incidentally, in this example, as shown in fig. 3 and 6, the planar dimension of the outer layer sheet 21 is such that it protrudes outward in the longitudinal direction from the inner layer sheet 22, and the protruding portion 21p of the outer layer sheet 21 is folded back inward in the longitudinal direction so as to cover the end 22e in the longitudinal direction of the inner layer sheet 22.

The belt members 20a, 20b are provided with lateral stretchability so that the belt members 20a, 20b can firmly hold the waist of the wearer when the diaper 1 is worn. However, from the viewpoint of suppressing the occurrence of wrinkles at the position of the absorbent core 11 of the absorbent body 10 and preventing the liquid absorption and leakage prevention properties thereof from being lowered, as shown in fig. 4, in the belt members 20a, 20b, particularly, the regions 20ac, 20bc overlapping with the absorbent core 11 of the absorbent body 10, are formed with the non-stretchable region AL having almost no stretchability.

Hereinafter, this will be described, and here, the basic configurations of the abdominal-side band member 20a and the back-side band member 20b are the same as each other. Therefore, in the following description, only the abdominal-side band member 20a will be described, and the back-side band member 20b will not be described. For convenience of explanation, the abdominal-side band member 20a will be described below as being divided into two regions AU and AD in the longitudinal direction as shown in a schematic plan view in fig. 7. That is, a region AU located on the side of the waist opening 1HB in the longitudinal direction is referred to as an "upper region AU", and a region AD located on the side of the leg opening 1HL is referred to as a "lower region AD".

As shown in fig. 7, the absorbent core 11 of the absorbent main body 10 does not overlap the upper region AU. Therefore, in this area AU, stretchability is imparted over the entire length in the lateral direction. The stretchability is provided by arranging a plurality of elastic threads 25, 25 … … arranged in the transverse direction in an extended state in the transverse direction in the longitudinal direction and fixing them to the area AU, and the elastic threads 25 are fixed to the area AU by, for example, a hot melt adhesive applied to the elastic threads 25 or the area AU. Incidentally, as a specific example of the fineness of the elastic thread 25, for example, 400dtex to 1000dtex is exemplified, and as a specific example of the elastic thread 25, LYCRA (trademark) or the like is exemplified. The same applies to the elastic thread 27 provided in the lower area AD described later.

On the other hand, since the absorbent core 11 of the absorbent main body 10 overlaps the lateral central region ADc of the lower region AD, a non-stretchable region AL (corresponding to a low stretchable region) having almost no lateral stretchability is formed in the central region ADc, and since the absorbent core 11 does not substantially overlap the end side regions ADe, ADe located on both sides of the central region ADc, stretchable regions AH, AH (corresponding to a high stretchable region) having higher stretchability than the non-stretchable region AL are formed in the end side regions ADe, ADe.

Here, the non-expansion region AL of the central region ADc and the expansion regions AH, AH of the end regions ADe, ADe are formed as follows. First, as shown in fig. 8, a plurality of elastic threads 27s, 27s … … extending in the transverse direction along the transverse direction are arranged in the longitudinal direction between the outer sheet 21 and the inner sheet 22. The elastic thread 27s is substantially fixed by the hot melt adhesive in the region AH1 corresponding to the stretchable region AH in the end region ADe, and is substantially not fixed in the region AL1 corresponding to the non-stretchable region AL in the central region ADc. Therefore, when the elastic threads 27s and 27s … … are cut by pinching the band member 20a from both sides in the thickness direction by the cutting device 50 described later in the region AL1 corresponding to the non-stretchable region AL, the cut elastic threads 27 and 27 … … contract toward the lateral end side as shown in fig. 7, and the region AH1 corresponding to the stretchable region AH in the end side region ADe substantially stays while the region AL1 corresponding to the non-stretchable region AL in the central region ADc substantially does not stay, whereby the non-stretchable region AL is formed in the central region ADc and the stretchable region AH is formed in the end side region ADe.

Incidentally, in this example, at the time of cutting each of the elastic threads 27s, 27s … …, a linear pressure-contact portion j is formed at each position PC1 of the abdominal-side belt member 20a which is pinched from both sides in the thickness direction, as will be discussed later.

In the manufacturing apparatus 30 of the sheet member 20as of the present embodiment, as an example of the sheet member 20as, a continuous body 20as in which a plurality of the abdominal-side band members 20a are connected in the lateral direction is formed. Fig. 9A is a schematic plan view for explaining the sheet member 20as immediately before being conveyed to the manufacturing apparatus 30. At this time, the sheet member 20as is in the following state: the plurality of abdominal- side belt members 20a, 20a … … are connected in the transverse direction in a state where the elastic threads 25s, 27s are not cut. That is, the sheet member 20as is in a state of a composite sheet 20as in which the continuous bodies 25s, 25s … … of the plurality of elastic threads and the continuous bodies 27s, 27s … … of the plurality of elastic threads are interposed between the continuous sheet 21s (corresponding to the first continuous sheet) of the outer sheet and the continuous sheet 22s (corresponding to the second continuous sheet) of the inner sheet, and the two continuous sheets 21s, 22s are joined. The plurality of elastic thread continuous bodies 25s and 25s … … and the plurality of elastic thread continuous bodies 27s and 27s … … are arranged along the continuous direction of the sheet-like member 20as (corresponding to the composite sheet) in an elongated state in the continuous direction and are aligned in the width direction of the sheet-like member 20 as. The sheet member 20as has a region on one side in the width direction corresponding to the upper region AU of the abdominal-side band member 20a, and a region on the other side corresponding to the lower region AD of the abdominal-side band member 20 a. Therefore, in the area AU on the one side of the former, in order to form the stretchable area over the entire length in the continuous direction, the corresponding continuous bodies 25s and 25s … … of the plurality of elastic threads are fixed to the respective continuous sheets 21s and 22s of the sheet-like member 20as with the hot melt adhesive over the entire length in the continuous direction. On the other hand, in the region AD on the other side of the latter, the stretchable region AH and the non-stretchable region AL are formed in a continuous direction, and therefore, the corresponding plurality of elastic thread continuations 27s, 27s … … are intermittently fixed to the respective continuous pieces 21s, 22s of the sheet-like member 20as in the continuous direction by the hot melt adhesive. That is, in the region AH1 corresponding to the stretch region AH of each continuous piece 21s, 22s in fig. 9A, the continuous bodies 27s, 27s … … of the elastic thread are fixed by the hot melt adhesive, but are not fixed in the region AL1 corresponding to the non-stretch region AL. In this case, as shown in fig. 9A, in the respective continuous pieces 21s and 22s, the region AH1 corresponding to the stretchable region AH and the region AL1 corresponding to the non-stretchable region AL are aligned in the continuous direction at a ratio of 2 to 1, because the stretchable regions AH and AH are present on both sides of the non-stretchable region AL in the lateral direction in the single-piece abdominal belt member 20a of fig. 7. However, in fig. 9A, it is not necessary to separately describe each of the regions AH1, AH1 corresponding to the two adjacent telescopic regions AH, and therefore, the following description will describe the two regions AH1, AH1 together as a single region AH 2. In this case, as shown in fig. 9A, the regions AH2 corresponding to the telescopic regions AH, AH and the regions AL1 corresponding to the non-telescopic regions AL appear alternately in the continuous direction in the sheet member 20 as. In addition, a region AL1 corresponding to the non-stretch region AL appears on the sheet member 20as at the product pitch of the diaper 1 in the continuous direction. Therefore, in the manufacturing apparatus 30, the continuous bodies 27s, 27s … … of the elastic threads of the sheet member 20as are cut at the product pitch of the diapers 1 in the continuous direction, and thereby the stretchable regions AH, AH and the non-stretchable regions AL are alternately formed in the sheet member 20as in the continuous direction, as shown in fig. 9B. The continuous body 20as of the abdominal- side band members 20a and 20a … … as shown in fig. 9B is generated by the above processing.

In the following description, the continuous direction of the sheet member 20as is also referred to as the "MD direction", and the width direction of the sheet member 20as is also referred to as the "CD direction". Incidentally, the three of the thickness direction of the sheet member 20as, the MD direction, which is the continuous direction, and the CD direction, which is the width direction, are orthogonal to each other.

Fig. 10A is a schematic side view of the manufacturing apparatus 30, and fig. 10B is a view taken along line B-B in fig. 10A.

As shown in fig. 10A, the manufacturing apparatus 30 includes a conveying device 40 that conveys the sheet member 20as having the continuous body 27s, 27s … … of the elastic thread with the MD direction as the conveying direction, and a cutting device 50 that cuts the continuous body 27s, 27s … … (corresponding to an elastic member) of the elastic thread of the sheet member 20 as.

The conveyance device 40 includes, for example, a plurality of conveyance rollers 40R and 40R … …. At least one of the plurality of conveyance rollers 40R, 40R … … is a drive roller that is rotationally driven about a rotation axis along the CD direction, and the conveyance roller 40R other than the drive roller is a driven roller that is rotated by receiving a rotational force from the sheet member 20as, for example. The conveying device 40 may have a belt conveyor instead of the conveying roller 40R or may have a belt conveyor in addition to the roller 40R.

The cutter device 50 includes a pair of upper and lower metal rollers 51u, 51d made of steel or the like, the rollers 51u, 51d having outer peripheral surfaces 51ua, 51da facing each other and rotating about a rotation axis along the CD direction, and a housing 55 for receiving a cutting reaction force acting on the rollers 51u, 51d when cutting the continuous body 27s, 27s … … of the elastic thread.

The pair of upper and lower rollers 51u and 51d are supported by bearing members 52u and 52d provided in the housing 55, respectively, and are thereby rotatable about a rotation axis parallel to the CD direction. The bearing member 52d of the lower roller 51d is immovably fixed to the housing 55, and the bearing member 52u of the upper roller 51u is vertically movable in a direction of contacting with or separating from the lower roller 51d by an appropriate actuator 53 such as a hydraulic cylinder or a pneumatic cylinder fixed to the housing 55. By controlling the actuator 53, the size of the gap between the outer peripheral surfaces 51ua and 51da of the pair of upper and lower rollers 51u and 51d and the size of the pressure contact force (N) which is a force in the contact or separation direction can be adjusted.

The rollers 51u and 51d are driven by a servo motor, not shown, as a driving source and rotate around the rotation axis. That is, the direction perpendicular to the rotation axis is rotationally driven as the rotational directions Dc51u and Dc51 d. Therefore, the sheet member 20as fed between the outer peripheral surfaces 51ua and 51da of the pair of upper and lower rollers 51u and 51d passes between the outer peripheral surfaces 51ua and 51da and is fed downstream in the MD direction.

In this example, the lower roller 51d is a cutter roller (corresponding to a cutter rotator) and the upper roller 51u is an anvil roller (corresponding to an anvil rotator). That is, at least one cutting block 54 is provided on the outer peripheral surface 51da of the lower roller 51d at an angle corresponding to the product pitch of the diaper 1 in the rotation direction Dc51 d. Specifically, in this example, as shown by hatching in fig. 10A, the two metal cutting blocks 54 and 54 are provided at an angle of 180 ° in the rotation direction Dc51 d. Further, a plurality of cutting blades C, C … … are formed on each of the cutter blocks 54 in a protruding manner, and the outer peripheral surface 51ua of the upper roller 51u, which is an anvil roller, is a smooth surface to receive the cutting blades C, C … …. Further, the rollers 51u and 51d are controlled to rotate in conjunction with the conveying operation of the sheet member 20as based on a synchronization signal or the like, and thereby the cutter roller 51d rotates so that the cutter block 54 faces the region AL1 every time the region AL1 corresponding to the non-stretching region AL passes through.

Therefore, each time the area AL1 corresponding to the non-stretch area AL of fig. 9A passes between the outer peripheral surfaces 51ua, 51da of the pair of rollers 51u, 51d, the area AL1 is nipped by the cutter blade C, C … … of the cutter block 54 of the cutter roller 51d and the anvil roller 51 u. Then, the continuous bodies 27s, 27s … … of the respective elastic threads are cut at the respective pinched positions PC1, whereby the cut elastic threads 27 contract toward an area AH1 corresponding to the high expansion and contraction area AH as shown in fig. 9B, and as a result, the non-expansion and contraction area AL and the expansion and contraction area AH are formed in the sheet member 20 as.

Fig. 11 is an explanatory diagram of the arrangement state of the cutter blades C, C … … provided on the cutter block 54 of the cutter roller 51d, and is a diagram showing the outer peripheral surface 51da of the roller 51d spread out on a plane.

As shown in fig. 11, in the cutting block 54, as the plurality of cutting blades C, C … …, cutting blades C, C … … having a linear cutting edge in a plan view are made of a metal such as cemented carbide. The length LC of the cutting edge in the extending direction is selected from the range of 4mm to 30mm, for example, and the dimension WC in the blade width direction perpendicular to the extending direction is selected from the range of 0.1mm to 1mm, for example. However, the shape of the cutting edge is not limited to the linear shape as described above, and may be a zigzag shape, for example, a zigzag shape, or a curved shape such as a circular arc shape. The cutting blades C, C … … are provided one for each of the continuous bodies 27s, 27s … … of elastic thread. Therefore, the continuous bodies 27s, 27s … … of the respective elastic threads can be reliably cut at one location PC in the MD direction.

Incidentally, in the example of fig. 11, the direction of the dicing blade C, C is inclined at an inclination angle α of an appropriate magnitude other than 90 ° from the CD direction, and not only the magnitude of the inclination angle α but also the inclination directions thereof are made uniform for all the dicing blades C, C … …. Specifically, in this example, the inclination angle α is set to 30 °, and the inclination direction is set so that the cutting edges of all the cutting blades C, C … … are displaced to the same side in the CD direction as they advance to the downstream side in the rotational direction Dc51 d. But is not limited to the above examples. That is, the size of the inclination angle α is not limited to the above 30 °, and the size of the inclination angle α may not be uniform for all the cutting blades C, C … …, and the inclination direction may not be uniform for all the cutting blades C, C … ….

As shown in fig. 10B, the cutter device 50 has edge rings 51SR and 51SR at respective ends of the cutter roller 51d in the CD direction. Each of the side rings 51SR and 51SR is an annular protrusion annularly protruding from the outer peripheral surface 51da of the cutter roller 51d over the entire circumference in the rotation direction Dc51 d. In a state where the outer peripheral surface 51SRa of the side ring 51SR is in contact with the outer peripheral surface 51ua of the anvil roller 51u, a gap G is formed between the cutting edge of the cutter blade C and the outer peripheral surface 51ua of the anvil roller 51u as shown in a schematic enlarged side view of fig. 12. Specifically, the size of the gap G is set to, for example, 1 μm to 20 μm, preferably 5 μm to 15 μm, and in this example 10 μm.

Further, with the above-described configuration, when the sheet-like member 20as passes through the cutter device 50, the cutter blade C of the cutter roller 51d and the outer peripheral surface 51ua of the anvil roller 51u nip the sheet-like member 20as with the gap G therebetween, and thus when the continuous bodies 27s, 27s … … of the elastic thread are cut at the nip position PC1 in the sheet-like member 20as, the pressure-contact portions j of the continuous sheet 21s of the outer layer sheet and the continuous sheet 22s of the inner layer sheet can be formed quickly at the position PC 1. That is, when the continuous body 27s of the elastic cord is cut by the cutter blade C, the continuous piece 21s and the continuous piece 22s can enter the gap G, and thereby the pressure-bonded section j of the two pieces 21s and 22s can be formed in a substantially film shape having a thickness of 10 μm, for example, in the gap G. Also, as a result, the following can be effectively avoided: as the continuous body 27s of the elastic thread is cut, the two continuous sheets 21s and 22s are partially cut at the pinched position PC1 and penetrate in the thickness direction, and as a result, damage to the finally produced continuous body 20as of the sheet-like member 20as, i.e., the abdominal-side band member 20a, can be suppressed.

The actuator 53 such as the hydraulic cylinder described above applies a pressing force in the vertical direction to both the cutter roller 51d and the anvil roller 51u, thereby achieving a state in which the side rings 51SR and 51SR are in contact with the anvil roller 51u, and the size of the gap G can be maintained at a substantially constant value even when the sheet member 20as is nipped by the cutter blade C and the anvil roller 51u according to the contact state. In this case, various other clearances that may affect the clearance G, for example, clearances (clearances between the outer ring or the inner ring and the rolling elements, not shown) provided inside the bearing members 52d and 52u of the cutter roll 51d and the anvil roll 51u, are also reduced as so-called "looseness prevention" by the pressure contact force of the actuator 53. Further, this case also contributes effectively to maintaining the size of the gap G at a constant value.

Incidentally, in this example, the edge ring 51SR is provided to the cutter roller 51d, but is not limited to the above example. That is, the anvil roller 51u may be provided instead of the cutter roller 51d, or may be provided in addition to the cutter roller 51d and the anvil roller 51 u.

In the present embodiment, a heating mechanism for heating the cutting roller 51d and the anvil roller 51u is provided. This can improve the cutting performance of the cutter blade C of the cutter roller 51d with respect to the continuous body 27s of the elastic thread. That is, since the temperature of the cutter blade C is increased by heating the cutter roller 51d, when the sheet member 20as is nipped by the cutter blade C, appropriate heat can be rapidly input from the cutter blade C to the continuous sheet 21s of the outer layer sheet and the continuous sheet 22s of the inner layer sheet to soften the sheets 21s and 22 s. This makes it easy to push the cutter blade C in the thickness direction, and as a result, the pinching force of the cutter blade C can be made to easily act on the continuous body 27s of elastic thread, and the cuttability of the continuous body 27s of elastic thread can be improved.

However, if the temperature is excessively increased, the hot-melt adhesive in the sheet member 20as may adhere to the rollers 51u and 51 d. That is, as described above, the hot melt adhesive is used for fixing the continuous body 27s of the elastic thread, but the adhesive is melted by heat input to the adhesive, and the adhesive has high fluidity and easily seeps out in the thickness direction of the sheet member 20as, and as a result, when coming into contact with the sheet member 20as, the adhesive may adhere to and accumulate on the outer peripheral surface 51da of the cutter blade C and the cutter roller 51d, the outer peripheral surface 51ua of the anvil roller 51u, and the like. Then, when the deposit continues to form a large lump, and the deposit falls down on the sheet member 20as and is caught in, a portion of the sheet member 20as where the deposit is caught becomes a defective product.

In the present embodiment, the heating of the rollers 51d and 51u is performed in such a range that the temperatures of the cutter blade C and the outer peripheral surface 51ua of the anvil roller 51u to be received by the cutter blade C are respectively lower than the melting point of the hot melt adhesive (corresponding to the thermoplastic adhesive). For example, in this example, a rubber-based hot-melt adhesive is used as the hot-melt adhesive, and the melting point thereof is 95 ℃. Therefore, the temperature of each of the rollers 51d and 51u is adjusted by heating so that the temperature of each of the rollers 51d and 51u is in the range of 50 ℃ or more and less than 95 ℃. Incidentally, 50 ℃ which is the lower limit value of the range of the above-described temperature adjustment is set to a temperature higher than, for example, the ambient temperature (the temperature of the ambient atmosphere) of the rollers 51d, 51 u. In addition, depending on the type of the hot-melt adhesive, the nominal value of the melting point may be unclear, and in this case, the value of the melting point may be replaced with the value of the softening point measured by the ring and ball method based on JISK 2351.

Fig. 13A and 13B are explanatory views of the heating mechanism. Fig. 13A is a schematic longitudinal sectional view of the cutter roller 51d and the anvil roller 51u, and fig. 13B is a sectional view B-B in fig. 13A. In addition, in fig. 13A, a partial structure 71p is shown in a cut-away manner.

As shown in fig. 13A, the heating mechanism includes: heating elements 71, 71 (corresponding to heating means) individually inserted into the cutter roller 51d and the anvil roller 51u, temperature sensors 75, 75 for measuring the temperature of the rollers 51d, 51u, and a temperature control unit 77 for controlling the amount of heat generated by the heating elements 71, 71 based on temperature signals output from the temperature sensors 75, 75.

The heating elements 71, 71 and the temperature sensors 75, 75 are provided for the rollers 51d, 51u, respectively, in correspondence with each other. The temperature control unit 77 associates the temperature sensors 75 and 75 with the heating elements 71 and 71, respectively, and controls the amount of heat generated by the corresponding heating element 71 based on the temperature signal of the temperature sensor 75. That is, the temperature signal of the temperature sensor 75 of the cutter roller 51d is used for temperature control of the heat generating element 71 in the cutter roller 51d, and the temperature signal of the temperature sensor 75 of the anvil roller 51u is used for temperature control of the heat generating element 71 in the anvil roller 51 u.

The heating element 71 and the temperature sensor 75 have substantially the same configuration regardless of whether they are used for the cutter roller 51d or the anvil roller 51 u. Therefore, only the heat generating element 71 and the temperature sensor 75 for the cutter roller 51d will be described below, and the heat generating element 71 and the temperature sensor 75 for the anvil roller 51u will not be described.

The heating element 71 is, for example, an electrothermal heater that generates heat based on supplied electric power, and more specifically, is a cylindrical heater 71 having a rod shape in the axial direction. The heater 71 is inserted into a housing hole 51dh provided in the roller 51d coaxially with the rotation axis of the roller 51d, coaxially with the roller 51d, so that the cutter roller 51d is uniformly heated by the heater 71 over the entire circumference in the rotation direction Dc51 d. The heat generated by the heater 71 is radially transferred in the radial direction of rotation of the roller 51d, and finally reaches the cutter blade C via the cutter block 54.

The cartridge heater 71 is of a known structure. Therefore, the following description is only limited to the extent necessary for understanding the present invention, and will not be described in detail. First, the heater 71 includes: a pipe 71p as a housing, and a heating wire 71c housed in the pipe 71p and wound in a coil shape with a substantially constant radius around the rotation axis. When the lead wires 71L and 71L connected to both ends of the heat generating wire 71c are connected to the power supply via the temperature control unit 77, the heat generating wire 71c generates heat with a heat generation amount (W) corresponding to the power (W) supplied from the power supply. Incidentally, in this example, by changing the magnitude of the supplied power and the number of turns N (turns/m) of the heat generating wire 71c per unit length in the axial direction (CD direction), the amount of heat generated per second per unit length in the axial direction (W/m) can be changed.

Further, according to this configuration, the adjustment to the temperature range is performed as follows. For example, the temperature control unit 77 supplies power to the heating element 71 when the instruction value of the temperature signal from the temperature sensor 75 is lower than the temperature range, and stops supplying power when the instruction value exceeds the temperature range. This makes it possible to substantially converge the temperature of the roller 51d at the temperature measurement position to 50 ℃ or higher and less than 95 ℃ which is the temperature range. Incidentally, the temperature control unit 77 is, for example, a computer, a PLC (programmable logic controller), or the like, and performs the above-described power supply operation by reading an appropriate program from a memory by a processor provided in the temperature control unit and executing the program.

As the temperature sensor 75, for example, a thermocouple is used. In addition, the temperature measurement position of the thermocouple is a position on the back side of the cutting block 54. That is, as shown in fig. 13B, the position in the rotational radial direction is the position between the cutting block 54 and the heating element 71, and as shown in fig. 13A, the position in the CD direction is a predetermined position within the area a54 where the cutting block 54 is located. Further, in the example of fig. 13A, when the area a54 is assumed to be divided into two in the CD direction, the predetermined position of the temperature sensor 75 is included in the area a54E where the dicing blade C is located, and is not included in the area a54N where the dicing blade C is not present.

Therefore, the sensor 75 can measure the temperature of the portion close to the cutting blade C, and the amount of heating of the cutter roller 51d can be adjusted by the measured temperature value, so that the temperature of the roller 51d can be adjusted with appropriate accuracy and appropriate responsiveness. This makes it possible to substantially reliably converge the temperature within the above-described temperature range, and as a result, adhesion of the hot melt adhesive to the cutter blade C, the cutter block 54, the outer peripheral surface 51da of the cutter roller 51d, and the like can be more effectively prevented. However, the temperature measuring position of the temperature sensor 75 is not limited to the position on the back side of the cutting block 54 exemplified above, and the sensor 75 is not limited to a thermocouple.

Incidentally, this heating mechanism also functions as a uniform heating device for making the temperature distribution of each roller 51d (51u) uniform in the CD direction, and this will be described below. First, in each roller 51d (51u) in fig. 13A, there is a temperature distribution in the CD direction due to the fact that the heat radiation property differs depending on the position in the CD direction, and more specifically, there is a temperature difference Δ Tce in which the temperature of the central portion 51dc (51uc) in the CD direction is higher than the temperature of the end portion 51de (51 ue). Further, the temperature difference Δ Tce may adversely affect the stable formation of the pressure-bonding section j. For example, as described above, in order to form the pressure-bonding section j, the gap G (fig. 12) is required between the cutter blade C and the outer peripheral surface 51ua of the anvil roller 51u, but when the temperature difference Δ Tce as described above is present, even if the gap G of an appropriate size is formed at the end 51de (51ue) in the CD direction, the size of the gap G is excessively small at the central portion 51dc (51dc), and thus the pressure-bonding section j may not be formed by penetration in the thickness direction. Therefore, the heating means makes the temperature distribution of each roller 51d (51u) uniform in the CD direction for the purpose of keeping the size of the gap G substantially constant in the CD direction.

Hereinafter, a study for causing the heating mechanism to function as a soaking device is described, and the study is the same for both the cutter roll 51d and the anvil roll 51 u. Therefore, the cutter roller 51d will be described below as an example.

In the example of fig. 13A, the amount of heat generation (W/m) of the heating element 71 is changed according to the position in the CD direction based on a predetermined heating pattern. That is, in this heating mode, the temperature difference Δ Tce is compensated by increasing the amount of heat generation (W/m) at the end portion 51de to be larger than the amount of heat generation (W/m) at the center portion 51 dc. The difference in the amount of heat generation can be realized by setting the number of turns N (turns/m) of the heat generation wire 71c to have a difference matching the temperature difference Δ Tce between the end portion 51de and the central portion 51 dc. That is, in this example, the number of turns N (turns/m) at the end portion 51de is made larger than the number of turns N (turns/m) at the central portion 51dc, thereby increasing the amount of heat generation at the end portion 51de as compared with the amount of heat generation at the central portion 51 dc. However, the method of making the heat generation amount different between the end portion 51de and the central portion 51dc is not limited to this method, and other methods may be used. For example, the amount of heat generation may be different by making the resistance of the heat generation line 71c different between the end portion 51de and the central portion 51 dc.

Incidentally, it is preferable that the sheet member 20as has a lubricant. Further, with this configuration, the lubricant can quickly perform a lubricating action when the outer layer sheet and the inner layer sheet are nipped by the cutter blade C, and thus the continuous body 27s of the elastic thread can be cut by the cutter blade C while the outer layer sheet and the inner layer sheet are not cut by the respective continuous sheets 21s and 22 s. Examples of the lubricant include a surfactant and an oil agent, and more specifically, oleic acid amide, erucic acid amide, stearic acid amide, and the like, or a silicone oil such as a modified silicone oil containing an amino acid, an animal or vegetable oil such as olive oil, liquid paraffin, and the like. However, it is not limited to the above materials. That is, if the friction coefficient at the position of the sheet member 20as to which the predetermined material is applied can be made lower than the friction coefficient before the application, the material may also perform the above-described lubricating action. Therefore, the material can also be used as the above-mentioned lubricant. Incidentally, the measurement of the coefficient of friction can be carried out using an automatic surface performance tester (KES-FB4-AUTO-A) or A friction feeling tester (KES-SE) (both manufactured by KAPPON CO., LTD.) and, as A method for containing A lubricant in the sheet member 20as, A well-known coating method such as slot coating can be exemplified.

Preferably, the hot melt adhesive is applied not to the respective continuous sheets 21s and 22s of the outer layer sheet and the inner layer sheet but to the continuous body 27s of the elastic thread. Further, with the above-described configuration, the continuous body 27s of the elastic thread can be fixed by a relatively small amount as compared with the case of applying the elastic thread to the respective continuous sheets 21s and 22 s. That is, the amount of the adhesive remaining in the sheet member 20as without contributing to the fixation of the continuous body 27s of the elastic thread can be greatly reduced. As a result, the sheet member 20as can be cured when the coating amount is too large can be suppressed, and the flexibility of the sheet member 20as can be easily ensured.

Incidentally, as for the coating method, the following method can be exemplified. Fig. 14A is a schematic side view showing a state of coating, and fig. 14B is a view from B-B in fig. 14A. First, as shown in fig. 14B, the adhesive in a substantially molten state is continuously injected from the injection hole N of the hot-melt adhesive to the continuous body 27s of the elastic thread conveyed in the continuous direction in an omega-like or spiral application pattern. Then, as shown in fig. 14A, the adhesive is wound around the outer peripheral surface of the continuous body 27s of the elastic cord from above to immediately below the outer peripheral surface, and as a result, the adhesive is applied over the entire circumference of the outer peripheral surface of the continuous body 27s of the elastic cord.

In addition, as shown in the schematic side view of fig. 15, the sheet member 20as may be wound around the roller 51d (51u) heated by the heating means at a predetermined winding angle dw. In the present embodiment, since both the cutter roller 51d and the anvil roller 51u are heated, either roller 51d (51u) can be wound around the cutter roller 51d in the example of fig. 15, or the anvil roller 51u can be wound around the cutter roller 51 d. Further, with the above configuration, the conveyance state of the sheet member 20as can be stabilized, and thus the cut damage of the continuous body 27s of elastic thread can be more effectively suppressed. Further, it is preferable that the winding is performed at a position upstream in the rotation direction Dc51d from the position PZ at which the continuous body 27s of the elastic thread is cut, and with the above configuration, the sheet member 20as can be sufficiently heated before the continuous body 27s of the elastic thread is cut. As a result, based on the mechanism in which the pinching pressure is easily applied to the continuous body 27s as described above, the cutting damage of the continuous body 27s can be more effectively suppressed.

In this case, the winding angle dw may be, for example, 10 ° to 60 °, and preferably 20 ° to 40 °. Incidentally, as the definition of the winding angle dw, for example, "an angle dw formed between a first line segment connecting a position Pss coming into contact with the outer peripheral surface 51da (51ua) of the roller 51d (51u) and the rotation shaft of the roller 51d and a second line segment connecting a position Pse coming away from the roller 51d (51u) and the rotation shaft" can be exemplified.

Other embodiments are also possible

While the embodiments of the present invention have been described above, the above embodiments are intended to facilitate understanding of the present invention and are not intended to be restrictive. The present invention may be modified or improved without departing from the gist thereof, and it is needless to say that the present invention also includes equivalent structures thereof. For example, the following modifications can be made.

In the above embodiment, a rubber hot-melt adhesive is exemplified as the thermoplastic adhesive, and the melting point thereof is 95 ℃. However, the adhesive is not limited to the rubber-based hot-melt adhesive as long as it is a thermoplastic adhesive. For example, an olefin hot melt adhesive having a melting point of 110 ℃ or the like may be used as the adhesive.

In the above embodiment, both the cutter roll 51d and the anvil roll 51u have the cartridge heater 71 as a heating means, respectively, but the present invention is not limited thereto. For example, only one of the cutter roll 51d and the anvil roll 51u may be provided with the cartridge heater 71 as a heating member, and in this case, the effect of suppressing the cut damage of the continuous body 27s of the elastic thread can be achieved accordingly.

In the above embodiment, the housing hole 51dh (51uh) of the cartridge heater 71 as the heating member is formed coaxially with the rotation shaft of each roller 51d (51u), and one cartridge heater 71 is inserted into the housing hole 51dh (51uh), but the invention is not limited thereto. For example, the housing holes 51dh (51uh) may be formed at positions equally dividing the rollers 51d (51u) in the rotational direction Dc51d (Dc51u) and equidistant from the rotational axis in the rotational radius direction, and the cartridge heaters 71 may be housed in the housing holes 51dh (51 uh).

In the above embodiment, the cartridge heater 71 is exemplified as an example of the heating member, but the present invention is not limited to the cartridge heater as long as the rollers 51d (51u) can be heated. For example, an induction heating device may be used as the heating member. The induction heating device includes, for example, a dynamic magnetic field generating portion disposed to face the outer peripheral surface 51da (51ua) of each roller 51d (51u) without contact. The dynamic magnetic field generating unit applies a high-frequency dynamic magnetic field to the outer circumferential surface 51da (51ua), and generates a current inside each roller 51d (51u), thereby heating the roller 51d (51 u).

In the above embodiment, the non-stretch region AL is formed by cutting the continuous body 27s of each elastic member at the position PC (fig. 11) that is one location in the rotation direction Dc51d in the region AL1 corresponding to the non-stretch region AL and contracting the cut continuous body 27s of the elastic member toward the region AH1 corresponding to the stretch region AH.

For example, as shown in fig. 16A and 16B, the continuous body 27s of each elastic thread may be cut at a plurality of positions PC and PC … … in the rotation direction Dc51d in the region AL1 corresponding to the non-stretch region AL, and the continuous body 27s of the elastic thread may be cut into a chip shape in the region AL1, whereby the region AL1 may be the non-stretch region AL. In this case, the continuous body 27s of the elastic thread before cutting may be fixed by hot-melt adhesive bonding not only in the region AH1 corresponding to the stretchable region AH but also in the region AL1 corresponding to the non-stretchable region AL.

In the above embodiment, the cutter roll 51d has the side ring 51SR, but the side ring 51SR may not be provided as long as the above-described gap G (fig. 12) can be formed between the cutter blade C of the cutter roll 51d and the outer peripheral surface 51ua of the anvil roll 51 u. For example, the size of the gap G may be set to a constant value by adjusting the position in the vertical direction, which is the direction in which the cutting roller 51d contacts or separates, by controlling the position of the actuator 53 such as the hydraulic cylinder shown in fig. 10B. In this case, a feed screw mechanism that can perform position control using a servo motor as a drive source may be used as the actuator 53.

In the above embodiment, as shown in fig. 11, a plurality of elastic members are exemplified by the plurality of elastic member continuous bodies 27s, 27s … …, and one cutting blade C, C … … is provided for each of the plurality of elastic member continuous bodies 27s, 27s … …, but the present invention is not limited thereto. For example, one cutting blade C may be provided for two or three continuous elastic threads 27s as an example of two or more. That is, one cutting blade C may be provided so as to straddle two continuous bodies 27s, 27s of elastic threads or three continuous bodies 27s, 27s of elastic threads.

In the above embodiment, the sheet member 20as has the continuous sheet 21s of the outer layer sheet and the continuous sheet 22s of the inner layer sheet, but another continuous sheet may be further laminated.

In the above embodiment, the continuous body 27s of the elastic thread is exemplified as the elastic member, but the present invention is not limited thereto. For example, the elastic member may be a belt-like elastic member such as a continuous body of flat rubber.

In the above embodiment, the cutter roller 51d is exemplified as the cutter rotator, and the anvil roller 51u is exemplified as the anvil rotator, but the present invention is not limited thereto. For example, the cutting rotor and the anvil rotor may be endless belts.

In the above-described embodiment, the 3-piece type disposable diaper 1 is exemplified as an example of the absorbent article, but the present invention is not limited thereto. For example, the continuous body 27s of the elastic thread provided on the sheet member used for the 2-piece type disposable diaper may be cut by the cutting device 50 described above. Incidentally, the 2-piece type disposable diaper refers to a diaper of the following type: the absorbent article has an exterior sheet having a two-layer structure as a first member, the exterior sheet having a stomach-side portion, a crotch portion, and a back-side portion, and an absorbent body 10 as a second member fixed to the skin-side surface of the exterior sheet. In this case, the continuous sheet of the exterior sheet corresponds to the sheet member 20as, and the continuous bodies 27s, 27s … … of the respective elastic threads are interposed between the two layers of the continuous sheet of the exterior sheet.

In the above-described embodiment, the pants-type disposable diaper 1 is exemplified as an example of the absorbent article, but the present invention is not limited thereto. That is, a disposable diaper of a tape type may be used. In addition, the tape type disposable diaper refers to the following types of diapers: the waist belt has an abdominal portion for covering a waist of a wearer from an abdominal side and a back portion for covering the waist from a back side, and the abdominal portion and the back portion are connected by a fastening belt. Further, the absorbent article is not limited to the disposable diaper 1. That is, the manufacturing method and manufacturing apparatus 30 of the present invention can be applied to any absorbent article using the sheet member 20as described above as a material. Therefore, the concept of the absorbent article also includes a diaper and a sanitary napkin.

Description of the reference numerals

1 disposable diaper (absorbent article), 1HB waistline opening, 1HL leg opening, 10 absorbent main body, 10ea end, 10eb end, 11 absorbent core, 12 cover sheet, 13 front sheet, 15 back sheet, 15f resin film, 15nw nonwoven fabric, 17R elastic member, 20a abdominal belt member, 20ac central region, 20ae end, 20as sheet member, 20b back belt member, 20ae end, 21 outer sheet, 21p portion, continuous sheet (first continuous sheet) of 21s outer sheet, 22 inner sheet, 22e end, continuous sheet of 22s inner sheet, 25 elastic thread, continuous body of 25s elastic thread, 27 elastic thread, continuous body (elastic member) of 27s elastic thread, 30 manufacturing apparatus, 40 conveying apparatus, 40R conveying roller, 50 cutting apparatus, 51SR edge ring, 51 a, 51d outer peripheral surface cutting roller (cutting rotator), 51da outer peripheral surface, 51dc center portion, 51de end portion, 51dh housing hole, 51u anvil roller (anvil rotator), 51ua outer peripheral surface, 51uh housing hole, 52d bearing member, 52u bearing member, 53 actuator, 54 cutting block, 55 case, 71 cartridge heater (heat generating body), 71C heat generating wire, 71p tube, 75 temperature sensor, 77 temperature control portion, C cutter blade, j wire pressure-bonding portion, G gap, N injection hole, AU upper region, AD lower region, ADc center region, ADe end side region, AH expansion region (high expansion region), AH1 region, AH2 region, AL non-expansion region (low expansion region), AL1 region, PC position, PC1 position, PZ position, Pss position, Pse position, LSG stereo pleat, leg gather, CL10 substantially center portion, a54 region, a54 LG 54E region, a54N region.

Claims (6)

1. A method of manufacturing a sheet member relating to an absorbent article, the sheet member having a high stretch region and a low stretch region aligned in a predetermined direction, the low stretch region having a lower stretch in the predetermined direction than the high stretch region, the method comprising:

conveying a composite sheet, in which an elastic member continuous in the predetermined direction is interposed in an extended state in the predetermined direction between a first continuous thermoplastic sheet continuous in the predetermined direction and a second continuous thermoplastic sheet continuous in the predetermined direction, while the elastic member is fixed by a thermoplastic adhesive at least in a region corresponding to the high stretch region, by using the predetermined direction as a conveying direction;

forming the high stretch region and the low stretch region by cutting the elastic member at least one location in the conveyance direction in a region corresponding to the low stretch region, thereby aligning the composite sheet in the conveyance direction;

in the step of forming the high expansion and contraction region and the low expansion and contraction region, a heating member heats a rotating body of at least one of a cutting rotating body and an anvil rotating body such that a temperature of the rotating body is less than a melting point of the adhesive, the cutting rotating body and the anvil rotating body rotate with outer circumferential surfaces thereof facing each other, and a cutting knife of the outer circumferential surface of the cutting rotating body and the anvil rotating body nip the composite sheet when the composite sheet passes between the cutting rotating body and the anvil rotating body in the conveying direction, thereby forming a nip portion of the first continuous sheet and the second continuous sheet at a nip position of the composite sheet and cutting the elastic member,

the method of manufacturing a sheet member is characterized in that,

the rotating body heated by the heating member is both the cutting rotating body and the anvil rotating body,

the heating pattern heated by the heating member is defined by the amount of heat (W/m) injected per second per unit length in the CD direction intersecting the conveying direction,

based on the heating pattern, the heating member injects more heat (W/m) to an end portion of the rotating body in the CD direction than to a central portion of the rotating body in the CD direction.

2. The method of manufacturing a sheet member relating to an absorbent article according to claim 1,

the adhesive is applied to the elastic member.

3. The method of manufacturing a sheet member relating to an absorbent article according to claim 1 or 2,

the cutting knife is arranged on the peripheral surface of the cutting rotating body through a cutting block,

a temperature sensor for measuring the temperature of the cutting rotary body is arranged in a region where the cutting block is located in a CD direction intersecting the conveying direction,

and adjusting the heating amount of the cutting rotating body based on the temperature measurement value of the temperature sensor.

4. The method of manufacturing a sheet member relating to an absorbent article according to claim 1 or 2,

winding the composite sheet on any one of the cutting rotator and the anvil rotator.

5. The method of manufacturing a sheet member relating to an absorbent article according to claim 1 or 2,

the composite sheet has a lubricant.

6. An apparatus for manufacturing a sheet member relating to an absorbent article, the sheet member having a high stretch region and a low stretch region which are aligned in a predetermined direction, the low stretch region having a lower stretch in the predetermined direction than the high stretch region, the apparatus comprising:

a conveying device that conveys a composite sheet, which is configured such that an elastic member continuous in the predetermined direction is interposed in an extended state in the predetermined direction between a first continuous sheet continuous in the predetermined direction and a second continuous sheet continuous in the predetermined direction, and the elastic member is fixed with a thermoplastic adhesive at least in a region corresponding to the high stretch region, the composite sheet being conveyed in the predetermined direction as a conveying direction; and

a cutting device that forms the high stretch region and the low stretch region by cutting the elastic member at least one location in the conveyance direction in a region corresponding to the low stretch region, thereby aligning the composite sheet in the conveyance direction;

the cutting device includes a cutting rotor, an anvil rotor, and a heating member, wherein the cutting rotor and the anvil rotor rotate so that outer circumferential surfaces thereof face each other, the heating member heats at least one of the cutting rotor and the anvil rotor so that a temperature of the rotor is less than a melting point of the adhesive,

a cutting knife of an outer peripheral surface of the cutting rotary body and the anvil rotary body nip the composite sheet while the composite sheet passes between the cutting rotary body and the anvil rotary body along the conveying direction, thereby forming a nip portion of the first continuous sheet and the second continuous sheet at a position of the composite sheet being nipped and cutting off the elastic member,

the manufacturing apparatus of the sheet member is characterized in that,

the rotating body heated by the heating member is both the cutting rotating body and the anvil rotating body,

the heating pattern heated by the heating member is defined by the amount of heat (W/m) injected per second per unit length in the CD direction intersecting the conveying direction,

based on the heating pattern, the heating member injects more heat (W/m) to an end portion of the rotating body in the CD direction than to a central portion of the rotating body in the CD direction.

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