JP7238958B2 - COMPOSITE EXPANSION MEMBER AND MANUFACTURING APPARATUS AND MANUFACTURING METHOD THEREOF - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite stretchable member applicable to gathers of paper diapers, and a manufacturing apparatus and manufacturing method thereof.

2. Description of the Related Art Conventionally, an absorbent article is known in which a waist portion and a crotch portion are composed of a composite stretchable member.
As a device for manufacturing composite elastic members, a method has been proposed in which an elastic member is placed on the surface of a sheet coated with a hot-melt material in a stretched state, and then another sheet is placed to cover the elastic member. It is As a result, the elastic member is arranged between the sheets, and the two sheets and the elastic member are joined to each other to manufacture the composite stretchable member (see Patent Document 1).

WO2014/010340

An object of the present invention is to provide a novel composite elastic member.

(1) In order to achieve the above objects, the composite stretchable member of the present invention is a composite stretchable member in which two sheet materials and an elastic member disposed between the sheet materials are welded together, The sheet material and the elastic member are not welded to each other, and a non-welding area is provided in which a dimension in the stretching direction of the elastic member exceeds a threshold value, and the sheet material and the elastic member are not welded in the non-welding area. The sheet materials are welded to each other at a position away from the overlapping portion.

(2) In order to achieve the above object, the apparatus for manufacturing a composite elastic member of the present invention is a device for manufacturing two sheets and an elastic member disposed between the sheet materials. A manufacturing apparatus for a composite stretchable member that manufactures a composite stretchable member by welding while conveying in a longitudinal direction, wherein the elastic member and the elastic member are sandwiched between the two sheet materials. To press the two sheets sandwiched by the elastic member between a conveying roller that conveys the sheet material and the outer peripheral surface of the conveying roller, thereby melting the elastic member and the sheet material. and a applying device for applying energy of the two sheets, wherein the outer peripheral surface of the conveying roller is provided with a convex portion projecting toward the applying device. A first protrusion that is welded to each sheet material, and a second protrusion that welds the sheet materials to each other at a position out of a position where the sheet material and the elastic member are superimposed, wherein the second protrusion is , wherein the first convex portion is not formed and is formed within a predetermined range in which the dimension in the circumferential direction exceeds a threshold value.

(3) Preferably, the applying device applies vibration energy as the energy.

(4) In order to achieve the above object, the method for manufacturing a composite elastic member of the present invention provides a composite elastic member in which two sheet materials and an elastic member disposed between the sheet materials are welded together. In the manufacturing method, when the dimension in the stretching direction of the non-welding region where the sheet material and the elastic member are not welded exceeds a threshold value, the sheet material and the elastic member are separated from each other in the non-welding region. It is characterized in that the sheet materials are welded together at a position away from the overlapped portion.

(5) It is preferable that the welding between the sheet material and the elastic member and the welding between the sheet materials are performed by applying ultrasonic vibration.

According to the present invention, a composite elastic member can be manufactured without using a hot-melt material, so a novel composite elastic member can be manufactured.

1 is an exploded view for explaining the overall configuration of a disposable diaper; FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; In addition, in FIG. 2, the thickness of each sheet is exaggerated in order to facilitate understanding of each configuration. FIG. 2 is a schematic diagram for explaining the configuration of the gathers, and is an enlarged view of a main part viewed from the direction B in FIG. 1; It is a schematic diagram which shows the whole structure of the manufacturing apparatus of gathers. FIG. 4 is a schematic developed view showing the configuration of the gathers; FIG. 4 is a schematic developed view of the main part of the anvil roller peripheral surface for explaining the configuration of the ridges of the anvil roller.

Hereinafter, the form for carrying out this case is demonstrated. The following embodiments are merely examples, and are not intended to exclude various modifications and application of techniques not explicitly described in these embodiments. Each configuration of this embodiment can be modified in various ways without departing from the gist thereof. In addition, they can be selected as necessary, and can be combined as appropriate.

In the following embodiments, an example in which the composite elastic member is used for a disposable diaper (absorbent article) will be described.

In each embodiment, the longitudinal direction L of the paper diaper is the direction connecting the front body arranged to face the abdomen of the wearer and the back body arranged to face the back of the wearer. Between the front body and the back body (at the center in the longitudinal direction), a crotch part is positioned at the wearer's crotch (located facing the crotch).
In addition, in a state where the disposable diaper is worn by the wearer (hereinafter abbreviated as "wearing state"), the side facing the wearer's skin (inner side) is the skin side, and the side opposite the skin side (outer side) is the non-skin side. Use the skin side. Further, the direction connecting the skin surface side and the non-skin surface side is defined as the thickness direction T, and the direction perpendicular to both the longitudinal direction L and the thickness direction T is defined as the width direction W. In addition, viewing from the thickness direction T is defined as planar view.
In addition, the longitudinal direction L, thickness direction T and width direction W of the article constituting the disposable diaper follow this.
As for the manufacturing apparatus, the direction in which the sheet material and the rubber thread are conveyed corresponds to the width direction W of the paper diaper, and the width direction perpendicular to the direction of conveyance corresponds to the longitudinal direction L of the paper diaper.

[1. overall structure]
The overall configuration of the disposable diaper and gather manufacturing apparatus will be described.
[1-1. Overall configuration of paper diaper]
First, with reference to FIG. 1, the basic configuration of the paper diaper 1 will be described.
Here, the paper diaper 1 is formed symmetrically with respect to the center line CL in the width direction W as a reference. The paper diaper 1 is roughly divided into three regions along the longitudinal direction L, ie, a front body 1A, a crotch part 1B and a back body 1C.

<Sheets>
First, the sheets of the paper diaper 1 will be described.
As shown in FIG. 1, the paper diaper 1 incorporates an absorbent body 10 (indicated by a thick dashed line) extending in the longitudinal direction L over the front body 1A, the crotch part 1B and the back body 1C. Here, an hourglass-shaped absorber 10 in which the crotch portion 1B has a widthwise dimension W smaller than that of the front body 1A and the back body 1C when viewed from the front in the unfolded state is illustrated.

The absorber 10 has a water absorption property that absorbs and retains water in liquids such as urine and menstrual blood excreted by the wearer. Compression grooves 10a and 10b that intersect each other are provided on the skin surface side (absorbent surface side) of the absorbent body 10 and on the center sheet 11, which will be described later, in order to improve the fit, water absorbency, and breathability of the paper diaper 1 to the wearer. It extends linearly.

As shown in FIG. 2, various sheets 11, 12, 13 and 14 described below are provided on the skin side and the non-skin side of the absorber 10 described above.
A center sheet 11 is laminated on the absorbent body 10 on the skin side, and a back sheet 12 is laminated on the non-skin side. A side seat 13 is arranged on the side of the seats 11 and 12 in the width direction W. As shown in FIG.

The cover sheet 14 covers the absorbent body 10 and the sheets 11, 12, 13 from the non-skin side. As shown in FIG. 1, the cover sheet 14 of the front body 1A and the cover sheet 14 of the back body 1C are attached to each other at their widthwise edges 14a. Each cover sheet 14 of 1C is joined to form the underpants-type disposable diaper 1 .

<gather>
Next, the gathers 15 of the disposable diaper 1 will be described with reference to FIGS. 1 to 3. FIG.
The gathers 15 are configured as a composite stretchable member having stretchability.
Gathers 16 , 17 , and 18 are illustrated as gathers 15 . One is the three-dimensional gathers 16 provided on the edge of the skin side of the side sheet 13, the other is the tummy gathers 17 provided on the front body 1A and the back body 1C. One is a second three-dimensional gather 18 (not shown in FIG. 1) provided at the edge portion in the width direction W on the non-skin surface side of the side sheet 13 .

Taking the tummy gather 17 as an example, the tummy gather 17 is constructed by sandwiching a stretchable rubber thread 20 (elastic member) between two sheet members 15a and 15b in a stretched state. The thread rubber 20 extends in the width direction W and is arranged in plurality along the longitudinal direction L. As shown in FIG. Both the sheet materials 15a and 15b and the rubber thread 20 have a plurality of linear welding portions (hereinafter also referred to as "welding lines") 30 (hereinafter also referred to as "welding lines") extending in the longitudinal direction L and provided along the width direction W as a whole. and omitted in FIG. 2), and the sheet materials 15a and 15b are welded together by circular dot-shaped welding portions 31C. In a natural state in which no tensile force is applied to the rubber thread 20 (that is, a state in which the rubber thread 20 is contracted, which was in an elongated state at the time of manufacture), the sheet material 15a , 15b are crimped to form convex folds 40. FIG.
Further, the outer peripheral portion of the rubber thread 20 is provided with a coating layer made of magnesium stearate, which has a lower melting point than the main body (core portion) of the rubber thread 20 .

The three-dimensional gathers 16 are provided in order to prevent leakage of excrement in the width direction W side by enhancing the followability to the wearer at the periphery of the excretion site. The tummy gathers 17 are provided to enhance the followability to the wearer's buttocks and lower abdomen. The second three-dimensional gathers 18 are provided in order to improve followability in the crotch portion 1B.

[1-2. Overall configuration of manufacturing equipment]
With reference to FIG. 4, an apparatus 100 for producing the gathers 15 (an apparatus for producing a composite stretchable member) will be described by taking the apparatus 100 for producing the tummy gathers 17 as an example.
The manufacturing apparatus 100 is a joining apparatus 200 that joins the rubber thread 20 to the sheet materials 15a and 15b and the sheet materials 15a and 15b by ultrasonic welding in a state in which the rubber thread 20 is sandwiched between the sheet materials 15a and 15b. have The joining device 200 has an anvil roller 210 (conveying roller) and a horn 220 (applying device). In addition, in FIG. 4, the thread rubber 20 is shown by the broken line for convenience.

The anvil roller 210 is a rotating member that rotates around an axis extending in a direction perpendicular to the plane of FIG. 4 . Hereinafter, the direction perpendicular to the paper surface of FIG. 4 is referred to as the front-rear direction. The anvil roller 210 rotates to convey the rubber thread 20 sandwiched between the sheet materials 15a and 15b on its outer peripheral surface. In the example shown in FIG. 4, the anvil roller 210 rotates clockwise in FIG. Hereinafter, the sheet materials 15a and 15b in which the rubber thread 20 is sandwiched and before ultrasonic welding (bonding) by the bonding device 200 may be referred to as "pre-welding sheet materials 15a and 15b". The outer circumferential surface of the anvil roller 210 is formed with linear protrusions (hereinafter also referred to as “protrusions”; omitted in FIG. 4) and circular dot-like protrusions protruding radially outward.

The horn 220 presses the pre-welding sheet materials 15a and 15b conveyed by the anvil roller 210 with the convex portion of the anvil roller 210 (pressing while pinching) to the pre-welding sheet materials 15a and 15b. It is a device for applying ultrasonic vibration (energy) for melting the pre-welding sheet materials 15a and 15b and the rubber thread 20. FIG. Horn 220 is arranged to face the outer peripheral surface of anvil roller 210 . In the example of FIG. 4, it is arranged to face the left portion of the outer peripheral surface of the anvil roller 210 . The tip of the horn 220 is provided with an output portion 221 that outputs energy for ultrasonic vibration applied toward the outer peripheral surface of the anvil roller 210 .

The horn 220 applies ultrasonic vibration to the pre-welding sheet materials 15a and 15b while pressing the output portion 221 against the pre-welding sheet materials 15a and 15b and pinching the pre-welding sheet materials 15a and 15b with the anvil roller 210. . As a result, the sheet materials 15a and 15b are melted and welded to each other. The outer circumference of the rubber thread 20 is also melted, and the rubber thread 20 and the sheet members 15a and 15b are welded to each other. Alternatively, the rubber thread 20 is melted and cut (fused), and the sheet members 15a and 15b are welded to each other. Specifically, the output portion 221 presses the pre-welding sheet materials 15a and 15b between the convex portions of the outer peripheral surface of the anvil roller 210, and the pre-welding sheet materials 15a and 15b are arranged on the convex portions. The sheet materials 15a and 15b are fused together or the sheet materials 15a and 15b are welded to each other or to the rubber thread 20 in a dotted or linear manner. In other words, dot-shaped welded portions or linear welded portions (welded lines) for welding the sheet materials 15a and 15b and the rubber thread 20 are formed corresponding to (coinciding with) the shape of the convex portion.

As described above, since the outer peripheral portion of the rubber thread 20 is provided with a coating layer having a melting point lower than that of the main body of the rubber thread 20, when the rubber thread 20 and the sheet materials 15a and 15b are welded, the rubber thread 20 The coating layer (periphery) is melted without melting the main body, and the coating layer and the sheet members 15a and 15b are welded.

The output portion 221 of the horn 220 extends in the front-rear direction, and the horn 220 imparts ultrasonic vibration to the outer peripheral surface of the anvil roller 210 in the entire rotation axis direction of the anvil roller 210 . While the anvil roller 210 is conveying the pre-welded sheet materials 15a and 15b, the horn 220 constantly applies ultrasonic vibrations. Therefore, as the pre-welding sheet materials 15a and 15b are conveyed by the anvil roller 210, the pre-welding sheet materials 15a and 15b are continuously welded.

The rubber thread 20 is introduced onto the outer peripheral surface of the anvil roller 210 in a state parallel to the front-rear direction. arranged side by side. Further, the rubber thread 20 is introduced into the anvil roller 210 in a state of being stretched in the circumferential direction of the anvil roller 210 (stretched state). In this embodiment, the rubber thread 20 is introduced into the anvil roller 210 in an elongated state of 300% of the natural state (the natural state is assumed to be 100%). The stretched state of the rubber thread 20 introduced into the anvil roller 210 is not limited to 300% of the natural state, and can be set appropriately within the range of 150% to 400% of the natural state, for example.

[2. Configuration of main parts]
[2-1. Main configuration of the gather]
The gathers 15 of this embodiment will be described by taking the tummy gathers 17 as an example and referring to FIG.
As described above, the tummy gathers 17 are in a state in which the rubber thread 20 is sandwiched between the sheet materials 15a and 15b, and the sheet materials 15a and 15b and the rubber thread 20 are formed to cross the rubber thread 20. are welded (bonded) to each other. Since the sheet materials 15a and 15b are melted in the welded portion 30, the surfaces of the sheet materials 15a and 15b (surfaces facing opposite to each other) have a different appearance and feel from other unmelted portions. and can be recognized by sight and touch.

As the welding portions 30, in this embodiment, linear welding portions 31A and 31B (hereinafter also referred to as “welding lines 31A” and “welding lines 31B”) and circular dot-like welding portions 31C are provided.
The rubber thread 20 and the sheet materials 15a, 15b are welded at the welding lines 31A, 31B. The welding lines 31A and 31B are aligned with each other with respect to the center line CL1 along the alignment direction of the rubber thread 20 (in the example shown in FIG. 5, it is oriented along the longitudinal direction L. Therefore, hereinafter also referred to as "alignment direction L"). It is line symmetrical, and is alternately arranged in the stretching direction of the rubber thread 20 (in the example shown in FIG. 5, it is equal to the width direction W. Therefore, hereinafter also referred to as "stretching direction W").

The welding lines 31A and 31B are formed by alternately arranging welded portions that are slanted at the same angle and opposite to each other with respect to the alignment direction L. As shown in FIG. That is, it is formed so as to extend in the arranging direction L in a zigzag shape (triangular wave shape) while the inclination with respect to the arranging direction L is repeatedly reversed.
The welding lines 31A and 31B form a set of patterns, and this pattern is repeatedly formed along the expansion/contraction direction W except for a region S0, which will be described later.

In the center of the tummy gather 17 in the width direction W, there is provided an area Sa (non-welding area) where the welding lines 31A and 31B for welding the sheet materials 15a and 15b and the rubber thread 20 are not formed. This area Sa is set so as to surround an area S0 (hereinafter referred to as an "absorbent body arrangement area") that overlaps with the absorbent body 10 (see FIG. 1) in plan view in a state where the tummy gathers 17 constitute the paper diaper 1. , over the entire longitudinal direction L of the tummy gathers 17 .

That is, the rubber thread 20 is not welded to the sheet materials 15a and 15b in the absorber placement region S0. This is because when the welded portion of the rubber thread 20 solidifies after welding, the density increases and the hardness increases compared to before welding. This is because if the welding lines 31A and 31B are provided, the flexibility of the absorbent body placement region S0 is reduced, and it is expected that the fit of the absorbent body 10 to the wearer will be reduced.

Here, for a manufacturing reason to be described later, instead of providing the welding lines 31A and 31B in the area Sa, dot-shaped welding portions 31C are provided in a predetermined arrangement.
Specifically, a plurality of dot-shaped welding portions 31C are provided along each direction of the expansion/contraction direction W and the alignment direction L. As shown in FIG. The welding lines 31A and 31B are sequentially formed from right to left in FIG. are arranged so that the shortest distance L ₁ in the stretching direction W from the “welding line 31A ₁ ”) is equal to or less than the threshold value L ₀ (L ₁ ≤ L ₀ ). The shortest distance in the expansion/contraction direction W from the welding line 31B on the immediate left side of the region Sa (hereinafter referred to as “welding line 31B ₁ ” when specifically referring to this welding line) and the mutual distance in the expansion/contraction direction W are respectively , threshold value L ₀ or less.

The welding lines 31A and 31B weld the rubber thread 20 and the sheet materials 15a and 15b, whereas the welding portion 31C is provided outside the overlapping portions of the rubber thread 20 and the sheet materials 15a and 15b. The sheet materials 15a and 15b are welded together. When the sheet materials 15a and 15b are welded together, like the rubber thread 20, the sheet materials 15a and 15b are harder after welding and solidification than before welding (melting). Compared with rubber 20, the flexibility is high.
Therefore, by configuring as described above, the decrease in flexibility of the absorber placement region S0 is suppressed, and the fit to the wearer is enhanced.

[2-2. Main configuration of manufacturing equipment (pattern of ridges of anvil roller)]
The convex portion of the anvil roller 210 will be described.
The welded portions 31A, 31B, and 31C of the tummy gather 17 correspond to the pattern to which the projections of the anvil roller 210 are transferred, and the pitch of the rubber thread 20 of the tummy gather 17 corresponds to the thread supplied to the outer peripheral surface of the anvil roller 210. It corresponds to the pitch of the rubber 20.

Therefore, in FIG. 5, the longitudinal direction L can be called the axial direction A of the anvil roller 210, and the width direction W can be called the circumferential direction C of the anvil roller 210. In FIGS. The pitch of the rubber thread 20 supplied to the roller 210 is shown, and the shape and arrangement of the welded portions 31A, 31B, 31C show the shape and arrangement of the convex portions of the anvil roller 210. The welded portions 31A, 31B, 31C and the rubber thread 20 indicates the positional relationship between the projections 211A, 211B, 211C of the anvil roller 210 and the rubber thread 20. As shown in FIG.

The convex portions 211A, 211B, and 211C of the anvil roller 210 will be further described with reference to FIG.
FIG. 6 is a developed view of the peripheral surface of the anvil roller 210, and the sheet members 15a and 15b are omitted for convenience of explanation. Further, in FIG. 6, subscript numbers are attached to the ends of the reference numerals 211A, 211B, and 211C in order to distinguish the plurality of convex portions 211A, 211B, and 211C. When there is no particular distinction, they are simply described without a subscript at the end, such as ridges 211A, ridges 211B, and 211C. Note that only the uppermost protrusion 211C in the figure is denoted by a reference numeral.

The ridge 211A (first projection) forms the welding line 31A, and extends in the axial direction A in a zigzag shape, like the welding line 31A. The ridge 211B (first projection) forms the welding line 31B, and extends in the axial direction A in a zigzag shape like the welding line 31B. The convex portion 211C (second convex portion) forms the welding portion 31C, and has a circular dot shape like the welding portion 31C.

Region S is a region corresponding to region Sa in FIG. 5 (that is, a region where welding lines 31A and 31B are not provided in tummy gather 17). In FIG. 6, the width of the region S (the length in the circumferential direction C) is shown to be short for the sake of convenience.

The ridges 211A and 211B are arranged on both outer sides of the region S in the circumferential direction C. As shown in FIG. Specifically, a pattern consisting of ridges 211A and 211B is formed on each of the upstream side and the downstream side of the region S in the rotation direction D of the anvil roller 210 (hereinafter referred to as “roller rotation direction D”). It is repeatedly formed in the direction C.
On the other hand, a plurality of protrusions 211C are arranged in the region S along each of the axial direction A and the circumferential direction C. As shown in FIG.

The sheet materials 15a and 15b and the rubber thread 20 are conveyed by the rotation of the anvil roller 210 in the same direction as the roller rotation direction D, that is, from left to right in FIG. As a result, the sheet materials 15a, 15b and the rubber thread 20 are welded from the right protrusions 211A, 211B, 211C. That is, the ridges 211B ₁ , 211A ₁ , 211B ₂ , 211A ₂ , 211C ₁ to 211C ₃ , 211B ₃ , 211A ₃ , 211B ₄ , 211A ₄ connect the sheet materials 15a, 15b and the rubber thread 20 in this order to the horn 220 (Fig. 4), the sheet members 15a and 15b and the rubber thread 20 are welded.

If the distance in the circumferential direction C from the formation of the welded portion 30 to the formation of the next welded portion 30 exceeds a threshold value L ₀ (for example, 6 mm), the sonic (ultrasonic wave) becomes unstable. Since the width dimension of the absorber 10 is longer than the threshold value _L0 , if the protrusion 211C is not provided in the region S substantially coinciding with the absorber arrangement region S0, the welding line _31A1 is formed by the protrusion _211A2 . Since the distance Lc from this point to the formation of the weld line _31B1 on the left side of the region S, which is the next welded portion 30, exceeds the threshold value _L0 , the sonic (ultrasonic wave) becomes unstable.

Therefore, in the region S, a convex portion 211C is provided instead of the convex portions 211A and 211B. That is, the convex portion 211C ₁ is arranged such that the shortest distance L ₁ in the stretching direction W from the convex portion 211A ₂ is equal to or less than the threshold value L ₀ (L ₁ ≦L ₀ ). The arrangement of the projections 211C is set so that the shortest distance in the expansion/contraction direction W from _211B3 and the distance between them are each equal to or less than the threshold value _L0 . Along with the placement of this convex portion 211C, the welding portion 31C is similarly placed as described above.
The projecting portion 211C (and thus the welding portion 31C) is provided by removing the portion where the rubber thread 20 and the sheet materials 15a and 15b are overlapped, and welds the sheet materials 15a and 15b. Welding is originally performed to join the rubber thread 20 and the sheet materials 15a and 15b, and the welding that removes the overlapping portions of the rubber thread 20 and the sheet materials 15a and 15b is hereinafter referred to as "disposal welding". say.
By performing the dummy shot within the region S in this manner, the stability of the Sonic during manufacturing is maintained.

Here, the sonic stability means that the amount of energy of ultrasonic vibration input from the horn 220 to the rubber thread 20 and the sheet materials 15a and 15 (hereinafter referred to as "the amount of input energy") varies with time within the allowable range. means to be within If the distance in the stretching direction W to the next welding point is long, the amount of input energy becomes zero for a relatively long period of time, resulting in large fluctuations. When the amount of input energy fluctuates and the amount of energy input to the rubber 20 and the sheet materials 15a and 15 becomes intermittent, uneven welding of the rubber thread 20 and the sheet materials 15a and 15 occurs. The welding with the sheet materials 15a, 15 becomes unstable.
Therefore, dot-shaped convex portions 211C are provided in the region S to perform a random shot, thereby suppressing the fluctuation of the energy amount of the ultrasonic vibration.

The amount of energy of the ultrasonic vibrations is greatly influenced by the areas of the surfaces of the projections 211A, 211B, 211C facing the horn 220 (in other words, the areas of the welded portions 31A, 31B, 31C in the gathers 17).
Therefore, a reference range A0 that is long in the axial direction A and has a predetermined area is set, and "the area of the convex portion _211C1 within the reference area _A0 " in the development view of FIG. From the ratio R of the "area", it is possible to estimate the energy amount of the ultrasonic vibration, and thus the fluctuation of the energy amount of the ultrasonic vibration between the ridge _211A2 and the ridge _211C1 . It should be noted that "the area of the ridge _211A2 within the reference area A0" and "the area of the projection _211C1 within the reference area A0" are the areas of the surface facing the horn 220 that are shaded in FIG. area.
A minimum value of the ratio R is, for example, about 10 to 25%.

[2-3. effect]
(1) According to the present invention, the gathers 15 can be manufactured without using a hot-melt material, so a novel gathers 15 can be manufactured.
(2) In the predetermined area Sa where the dimension in the stretching direction W is set to exceed the threshold value L, and the sheet material 15a and the rubber thread 20 are not welded, the sheet material 15a and the rubber thread 20 are not welded. Welding can be performed stably. When the predetermined region S covers the absorber placement region S0, it is possible to suppress a decrease in the flexibility of the absorber placement region S0, and to keep the absorber 10 well fit to the wearer.

(3) In the gather 15, the welding lines 31A and 31B where the rubber thread 20 is welded to the sheet materials 15a and 15b are different in shape from the welding section 31C in the region Sa where the rubber thread 20 is not welded. It can be easily identified whether or not the region Sa where the rubber thread 20 is not welded is normally formed depending on whether or not the 31C can be visually recognized. That is, the quality of the gathers 15 can be easily inspected.

[3. others]

(1) In the above embodiment, the ridges 211A and 211B of the anvil roller 210 extend in a zigzag shape along the axial direction A, and the welding lines 31A and 31B of the gathers 15 extend along the longitudinal direction L accordingly. Although an example of zigzag extension has been described, the shape of the ridges and welding lines is not limited to this. For example, the ridges 211A and 211B may extend straight along the axial direction A, and the welding lines 31A and 31B may extend straight along the longitudinal direction L. Also, the convex portions 211C and the welded portions 31C may be rectangular dots, or may be linear or zigzag like the convex stripes 211A and 211B.

The welded portions 31C may be arranged in a broken line extending in the width direction W as shown in FIG. 5 (a plurality of welded portions may be arranged at intervals in the width direction W). It may be shaped (or may be a continuous weld). That is, in the region Sa, the welded portion 31C may be provided at a position where the rubber thread 20 and the sheet materials 15a and 15b are not bonded, and the shape of the welded portion 31C may be linear, regular broken line, or irregular broken line. can be

(2) In addition, on both sides in the width direction W of the region Sa (non-bonded regions between the rubber thread 20 and the sheet materials 15a and 15b) (that is, before and after the sheet material 15a and the like in the manufacturing process), the region Sa has elasticity. , the rubber thread 20 may be cut on both sides in the width direction W of the region Sa. In this case, the rubber thread 20 may be cut at any point within the region Sa of the gather 15 (composite elastic member) in which the rubber thread 20 is adhered to the sheet members 15a and 15b by the welding lines 31A and 31B.

The rubber thread 20 may be cut by applying greater energy to the welding lines 31A and 31B closest to the region Sa than to the other welding lines 31A and 31B, or by cutting the rubber thread 20 with the anvil roller 210. The distance from the horn 220 is changed, and the ridges 211A and 211B for cutting the rubber 20 are different from the normal ridges for forming the welding lines, so that force is easily applied to the rubber thread 20. By cutting the rubber thread 20, the area Sa is formed as a non-stretchable area where the stretching force of the rubber thread 20 does not act when the sheet materials 15a and 15b and the rubber thread 20 are welded. may

(3) In each of the above-described embodiments, the composite elastic member of the present invention and its manufacturing apparatus were applied to the tummy gather 17 and its production, but it can also be applied to the three-dimensional gather 16 or the second three-dimensional gather 18, and the expansion and contraction other than the gather can be performed. It can be applied where it is needed.

(4) The elastic member described above can be applied to gathers provided in various absorbent articles such as tape-type paper diapers, urine pads, sanitary napkins, and panty liners, in addition to the exemplified underpants-type paper diapers.
A stretchable film (elastic member) may be used instead of or in addition to the rubber thread 20 used for the stretchable member. In this case, a coating layer with a low melting point is provided on the outer peripheral portion of the film in the same manner as the rubber thread 20 described above.

1 disposable diaper 15 gather (composite elastic member)
15a, 15b sheet material 16 three-dimensional gather (composite elastic member)
17 Tammy gather (composite elastic member)
18 Second three-dimensional gather (composite elastic member)
20 Thread rubber (elastic member)
30, 31A, 31C welding part 40 fold 210 anvil roller (conveyance roller)
220 horn (applying device)
211A, 211B ridge (first ridge)
211C convex part (second convex part)
213, 215 recessed portion L longitudinal direction (alignment direction of the rubber thread 20)
L ₀ threshold W width direction (stretching direction of rubber thread 20)
S Region of anvil roller 210 where ridges are not formed Sa Region of tummy gather 17 where welded portion 30 is not formed (non-welded region)

Claims (1)

Two sheet materials are arranged between the two sheet materials, extend along the stretching direction, and are arranged side by side along the alignment direction orthogonal to the stretching direction in plan view. A method for manufacturing a composite stretchable member having a plurality of elastic members, wherein the two sheet materials and the elastic member are melted and welded by ultrasonic vibration ,
Predetermining a threshold value due to time fluctuation of the input energy amount of the ultrasonic vibration,
The two sheet materials and the elastic member are melted and welded by ultrasonic vibration at a plurality of positions spaced apart from each other in the stretching direction with dimensions equal to or smaller than the threshold value, thereby forming the two sheet materials. and the elastic member are welded to form two welding regions on the composite stretchable member separated by the threshold value or more in the stretching direction,
Between the two welded regions, at a plurality of positions away from the overlapping portion of the two sheet materials and the elastic member, and at a distance equal to or less than the threshold value in the stretching direction. By intermittently melting and welding the two sheet materials by ultrasonic vibration, the two sheet materials are welded together without welding the two sheet materials and the elastic member. A method for manufacturing a composite elastic member, characterized in that a welded region is formed in the composite elastic member .

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