JP2022043262A - Composite stretchable member, and production device and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel composite stretchable member.

SOLUTION: There is provided a composite stretchable member 17 which deposits two sheet materials 15a and 15b and an elastic member 20 arranged between the sheet materials 15a and 15b. The composite stretchable member has a non-deposition area Sa where the sheet materials 15a and 15b and the elastic member 20 are not deposited and a dimension in a stretchable direction W of the elastic member 20 exceeds a threshold value, and in the non-deposition area Sa, the sheet materials 15a and 15b are deposited at a position out of a position where the sheet materials 15a and 15b and the elastic member 20 overlap each other.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a composite elastic member applicable to gathers of disposable diapers, and a manufacturing apparatus and manufacturing method thereof.

Conventionally, an absorbent article in which the waistline portion and the inseam portion are composed of a composite elastic member is known.
As a device for manufacturing a composite elastic member, a method is proposed in which an elastic member is placed on the surface of a sheet coated with a hot melt material in an elongated state, and then another sheet is placed so as to cover the elastic member. Has been done. As a result, with the elastic member arranged between the sheets, the two sheets and the elastic member are joined to each other to manufacture a composite elastic member (see Patent Document 1).

International Publication 2014/010340

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

(1) In order to achieve the above object, the composite elastic member of the present invention is a composite elastic member for welding two sheet materials and an elastic member arranged between the sheet materials. The sheet material and the elastic member are not welded, and the elastic member has a non-welded region in which the dimension regarding the expansion / contraction direction is set to exceed the threshold value. In the non-welded region, the sheet material and the elastic member are used. It is characterized in that the sheet materials are welded to each other at a position away from the place where the sheets are overlapped.

(2) In order to achieve the above object, the apparatus for manufacturing a composite elastic member of the present invention uses two sheet materials and an elastic member arranged between the sheet materials as the length of the sheet material. A device for manufacturing a composite elastic member that is welded while being conveyed in the length direction to manufacture the composite elastic member, and the elastic member is sandwiched between the two sheet materials and the elastic member. To hold the two sheet materials in which the elastic member is sandwiched between the transfer roller that conveys the sheet material and the outer peripheral surface of the transfer roller, and to melt the elastic member and the sheet material. The outer peripheral surface of the transport roller is provided with a convex portion that projects toward the imparting device, and the elastic member is used as the convex portion of the two elastic members. Each of the first convex portions to be welded to the sheet material is provided with a second convex portion for welding the sheet materials to each other at a position separated from the portion where the sheet material and the elastic member are overlapped, and the second convex portion is provided. The first convex portion is not formed, and the dimension in the circumferential direction is formed in a predetermined range exceeding the threshold value.

(3) It is preferable that 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 is a composite elastic member for welding two sheet materials and an elastic member arranged between the sheet materials. In the manufacturing method, when the dimension of the non-welded region in which the sheet material and the elastic member are not welded exceeds the threshold value, the sheet material and the elastic member are formed in the non-welded region. It is characterized in that the sheet materials are welded to each other at a position away from the overlapping portion.

(5) It is preferable to perform welding of the sheet material and the elastic member and welding of the sheet materials by applying ultrasonic vibration, respectively.

According to the present invention, since the composite stretchable member can be manufactured without using the hot melt material, a new composite stretchable member can be manufactured.

It is a development drawing for demonstrating the whole composition of a disposable diaper. FIG. 1 is a cross-sectional view taken along the line AA of FIG. In FIG. 2, the thickness of each sheet is exaggerated to make it easier to understand each configuration. It is a schematic diagram for demonstrating the structure of gathers, and is the enlarged view of the main part seen from the B direction of FIG. It is a schematic diagram which shows the whole structure of the gather manufacturing apparatus. It is a schematic development view which shows the structure of gathers. It is a schematic development view of the main part of the peripheral surface of an anvil roller for demonstrating the composition of the ridge of an anvil roller.

Hereinafter, a mode for carrying out this case will be described. The following embodiments are merely examples, and there is no intention of excluding the application of various modifications and techniques not specified in this embodiment. Each configuration of the present embodiment can be variously modified and implemented without departing from the gist thereof. In addition, it can be selected as needed and can be combined as appropriate.

In the following embodiment, 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 is the direction connecting the front body arranged facing the abdomen of the wearer and the back body arranged facing the back of the disposable diaper. Between these front and back bodies (center in the longitudinal direction), the inseam located in the inseam of the wearer (arranged facing the crotch) is located.
In addition, when the disposable diaper is worn on the wearer (hereinafter abbreviated as "wearing state"), the side facing the skin (inside) of the wearer is the skin surface side, and the opposite side (outside) of the skin surface side is not. 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 orthogonal 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 a plan view.
Further, with respect to the articles constituting the disposable diaper, the longitudinal direction L, the thickness direction T and the width direction W shall follow this.
Further, in the manufacturing apparatus, the transport direction of the sheet material and the rubber thread corresponds to the width direction W of the disposable diaper, and the width direction orthogonal to the transport direction corresponds to the longitudinal direction L of the disposable diaper.

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

<Sheets>
First, the sheets of the disposable diaper 1 will be described.
As shown in FIG. 1, the disposable diaper 1 contains an absorber 10 (indicated by a thick broken line) extending in the longitudinal direction L over the front body 1A, the inseam 1B, and the back body 1C. Here, an hourglass-shaped absorber 10 having a smaller W dimension in the width direction in the inseam 1B than the front body 1A and the rear body 1C in the front view in the unfolded state is illustrated.

The absorber 10 has water absorbency that absorbs and retains liquid water such as urine and menstrual blood excreted from the wearer. In order to improve the fit, water absorption and breathability of the disposable diaper 1 to the wearer, the skin surface side (absorbent surface side) of the absorber 10 and the center sheet 11 described later have squeezing grooves 10a and 10b intersecting each other. It is extended linearly.

As shown in FIG. 2, various sheets 11, 12, 13, and 14 described below are provided on the skin surface side and the non-skin surface side with respect to the above-mentioned absorber 10.
The center sheet 11 is laminated on the skin surface side of the absorber 10, and the back sheet 12 is laminated on the non-skin surface side. Side seats 13 are arranged on the W side in the width direction of these seats 11 and 12.

The cover sheet 14 covers the above-mentioned absorber 10 and sheets 11, 12, 13 from the non-skin surface side. As shown in FIG. 1, the cover sheet 14 in the front body 1A and the cover sheet 14 in the rear body 1C have their respective widthwise edge portions 14a attached to each other so that the front body 1A and the rear body are attached to each other. Each cover sheet 14 of 1C is joined to form a pants-shaped disposable diaper 1.

<gather>
Next, the gather 15 of the disposable diaper 1 will be described with reference to FIGS. 1 to 3.
The gather 15 is configured as a composite elastic member having elasticity.
As the gather 15, gathers 16, 17, and 18 are exemplified. One is a three-dimensional gather 16 provided at the edge of the side sheet 13 on the skin surface side, and the other is a Tammy gather 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 Tammy Gather 17 as an example, Tammy Gather 17 is configured by sandwiching elastic thread rubber 20 (elastic member) between two sheet materials 15a and 15b in an extended state. A plurality of thread rubbers 20 extend in the width direction W and are arranged along the longitudinal direction L. Both the sheet materials 15a and 15b and the rubber thread 20 extend in the longitudinal direction L as a whole, and a plurality of linear welded portions (hereinafter, also referred to as “welded wires”) 30 provided along the width direction W (FIG. 1). And in FIG. 2), the sheets are welded to each other, and the sheet materials 15a and 15b are welded to each other by the circular dot-shaped welded portion 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 that was in the stretched state at the time of manufacture is contracted), the sheet material 15a is placed between the welded portions 30 adjacent to each other on the rubber thread 20. , 15b are wrinkled to form convex folds 40.
Further, a coating layer made of magnesium stearate having a melting point lower than that of the main body (core portion) of the rubber thread 20 is provided on the outer peripheral portion of the rubber thread 20.

The three-dimensional gather 16 is provided to prevent the excrement from leaking to the W side in the width direction by enhancing the followability to the wearer at the peripheral edge of the excretion portion. The Tammy Gather 17 is provided to enhance the followability of the wearer to the buttocks and lower abdomen. The second three-dimensional gather 18 is provided at the inseam 1B in order to improve the followability.

[1-2. Overall configuration of manufacturing equipment]
With reference to FIG. 4, the manufacturing apparatus 100 (manufacturing apparatus for the composite telescopic member) of the gather 15 will be described by taking the manufacturing apparatus 100 whose manufacturing target is the Tammy gather 17 as an example.
The manufacturing apparatus 100 is a joining device 200 in which the thread rubber 20 is sandwiched between the sheet materials 15a and 15b, and the thread rubber 20, the sheet materials 15a and 15b, and the sheet materials 15a and 15b are ultrasonically welded and joined. Has. The joining device 200 has an anvil roller 210 (conveying roller) and a horn 220 (applying device). In FIG. 4, the rubber thread 20 is shown by a broken line for convenience.

The anvil roller 210 is a rotating member that rotates about an axis extending in a direction orthogonal to the paper surface of FIG. Hereinafter, the direction orthogonal to the paper surface of FIG. 4 is referred to as a front-back direction. By rotating, the anvil roller 210 conveys the thread rubber 20 in a state of being sandwiched between the sheet materials 15a and 15b on the outer peripheral surface thereof. In the example shown in FIG. 4, the anvil roller 210 rotates clockwise in FIG. Hereinafter, the sheet materials 15a and 15b before ultrasonic welding (bonding) by the joining device 200 in a state where the thread rubber 20 is sandwiched may be referred to as "sheet materials 15a and 15b before welding". On the outer peripheral surface of the anvil roller 210, a linear convex portion (hereinafter, also referred to as a “convex”) protruding outward in the radial direction and a circular dot-shaped convex portion are formed.

The horn 220 is applied to the pre-welding sheet materials 15a and 15b while sandwiching (pressurizing while sandwiching) the pre-welding sheet materials 15a and 15b conveyed by the anvil roller 210 with the convex portion of the anvil roller 210. It is a device that applies ultrasonic vibration (energy) for melting the sheet materials 15a and 15b before welding and the rubber thread 20. The horn 220 is arranged so as to face the outer peripheral surface of the anvil roller 210. In the example of FIG. 4, they are arranged so as to face the left side portion of the outer peripheral surface of the anvil roller 210. At the tip of the horn 220, an output unit 221 for outputting energy for ultrasonic vibration applied toward the outer peripheral surface of the anvil roller 210 is provided.

The horn 220 presses the output unit 221 against the pre-welding sheet materials 15a and 15b, and applies ultrasonic vibration to the pre-welding sheet materials 15a and 15b while sandwiching 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. Further, the outer circumference of the rubber thread 20 is also melted, and the rubber thread 20 and the sheet materials 15a and 15b are welded to each other. Alternatively, the rubber thread 20 is melted and cut (fused), and the sheet materials 15a and 15b are welded to each other. Specifically, the output unit 221 sandwiches the pre-welding sheet materials 15a and 15b with the convex portions on the outer peripheral surface of the anvil roller 210, and is arranged on the convex portions of the pre-welding sheet materials 15a and 15b. The sheet materials 15a and 15b or the thread rubber 20 and the sheet materials 15a and 15b are welded to each other in a dot shape or a linear shape at the portion. In other words, a dot-shaped welded portion or a linear welded portion (welded wire) for welding the sheet materials 15a and 15b and the rubber thread 20 is formed corresponding to (matching) the shape of the convex portion.

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

The output unit 221 of the horn 220 extends in the front-rear direction, and the horn 220 applies 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 pre-welding sheet materials 15a and 15b are conveyed by the anvil roller 210, the horn 220 constantly applies ultrasonic vibration. 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 on the outer peripheral surface of the anvil roller 210 in a state parallel to the front-rear direction, and its width is on the outer peripheral surface of the anvil roller 210 and on the sheet material 15b previously introduced on the outer peripheral surface of the anvil roller 210. Arranged side by side in the direction. Further, the rubber thread 20 is introduced into the anvil roller 210 in a state of being extended (extended state) in the circumferential direction of the anvil roller 210. In the present embodiment, the rubber thread 20 is introduced into the anvil roller 210 in an extended state (the natural state is 100%) extended to 300% in the natural state. 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 appropriately set, for example, within the range of 150% to 400% of the natural state.

[2. Main part composition]
[2-1. Gather key components]
The gather 15 of the present embodiment will be described with reference to FIG. 5 by taking Tammy gather 17 as an example.
As described above, the tammy gather 17 has a welded portion 30 formed so that the sheet materials 15a and 15b and the thread rubber 20 cross the thread rubber 20 in a state where the thread rubber 20 is sandwiched between the sheet materials 15a and 15b. It is configured by being welded (bonded) to each other. Since the sheet materials 15a and 15b are melted in the welded portion 30, the surface of the sheet materials 15a and 15b (the surfaces facing opposite to each other) is provided as a portion having a different appearance and feel from other non-melted portions. It appears in and can be recognized visually and tactilely.

As the welded portion 30, in the present embodiment, linear welded portions 31A and 31B (hereinafter, also referred to as “welded wire 31A” and “welded wire 31B”) and circular dot-shaped welded portions 31C are provided.
In the welding wires 31A and 31B, the rubber thread 20 and the sheet materials 15a and 15b are welded. The welding lines 31A and 31B are oriented along the longitudinal direction L in the example shown in FIG. 5 with respect to the center line CL1 along the alignment direction of the rubber threads 20 (hereinafter, also referred to as “arrangement direction L”). It is line-symmetrical and is alternately arranged in the expansion / contraction direction of the rubber thread 20 (equal to the width direction W in the example shown in FIG. 5, therefore also referred to as “expansion / contraction direction W”).

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

In the Tammy Gather 17, a region Sa (non-welded region) in which the welding wires 31A and 31B for welding the sheet materials 15a and 15b and the thread rubber 20 are not formed is provided in the center of the width direction W. This region Sa is set so as to surround the region S0 (hereinafter referred to as “absorbent arrangement region”) that overlaps with the absorber 10 (see FIG. 1) in a plan view in a state where the Tammy gather 17 constitutes the disposable diaper 1. , Is provided over the entire longitudinal direction L of the diaper gather 17.

That is, in the absorber arrangement region S0, the rubber thread 20 is not welded to the sheet materials 15a and 15b. This is because when the welded portion of the rubber thread 20 is solidified after welding, the density becomes higher and the hardness increases as compared with that before welding, so that the rubber thread 20 is welded to the sheet materials 15a and 15b in the absorber arrangement region S0. This is because if the welding wires 31A and 31B are provided, the flexibility of the absorber arrangement region S0 is reduced, and the fit of the absorber 10 to the wearer is expected to be lowered.

Here, for manufacturing reasons described later, instead of providing the welding wires 31A and 31B, dot-shaped welding portions 31C are provided in a predetermined arrangement in the region Sa.
Specifically, a plurality of dot-shaped welded portions 31C are provided along each of the expansion / contraction direction W and the arrangement direction L. Further, the welding lines 31A and 31B are sequentially formed from right to left in FIG. 5, but the welding portion 31C is the welding line 31A immediately to the right of the region Sa (hereinafter, particularly when referring to this welding line). It is arranged so that the shortest distance L ₁ with respect to the expansion / contraction direction W from (referred to as “welded wire 31A ₁ ”) is equal to or less than the threshold value L ₀ (L ₁ ≦ L ₀ ), and further, in the present embodiment, The shortest distance in the expansion / contraction direction W from the welding line 31B immediately to the left of the region Sa (hereinafter, referred to as "welding line 31B ₁ " when referring to this welding line in particular) and the mutual distance in relation to the expansion / contraction direction W are respectively. The arrangement of the welded portion 31C is set so as to be equal to or less than the threshold L ₀ .

Further, the welding wires 31A and 31B are provided by welding the thread rubber 20 and the sheet materials 15a and 15b, whereas the welding portion 31C is provided by removing the portion where the thread rubber 20 and the sheet materials 15a and 15b overlap. The sheet materials 15a and 15b are welded together. When the sheet materials 15a and 15b are welded to each other, the sheet materials 15a and 15b have increased hardness after welding and solidification as compared with those before welding (melting), but the yarn after welding and solidification is increased. The flexibility is higher than that of the rubber 20.
Therefore, with the above configuration, the decrease in flexibility of the absorber placement region S0 is suppressed, and the fit to the wearer is enhanced.

[2-2. Main part configuration of manufacturing equipment (convex pattern of anvil rollers)]
The convex portion of the anvil roller 210 will be described.
The welded portions 31A, 31B, 31C of the tammy gather 17 correspond to the pattern in which the convex portion of the anvil roller 210 is transferred, and the pitch of the rubber thread 20 of the tammy gather 17 is the thread supplied to the outer peripheral surface of the anvil roller 210. Corresponds to the pitch of the rubber 20.

Therefore, in FIG. 5, the longitudinal direction L can be rephrased as the axial direction A of the anvil roller 210 and the width direction W as the circumferential direction C of the anvil roller 210, and in FIGS. 5 and 6, the pitch of the rubber thread 20 is anvil. The pitch of the thread rubber 20 supplied to the roller 210 is shown, and the shapes and arrangements of the welded portions 31A, 31B and 31C indicate the shape and arrangement of the convex portions of the anvil roller 210, and the welded parts 31A, 31B and 31C and the thread rubber are shown. Each positional relationship with 20 indicates the positional relationship between the convex portions 211A, 211B, 211C of the anvil roller 210 and the thread rubber 20.

The convex portions 211A, 211B, 211C of the anvil roller 210 will be further described with reference to FIG.
FIG. 6 is a development view of a main part of the peripheral surface of the anvil roller 210, and the sheet materials 15a and 15b are omitted for convenience of explanation. Further, in FIG. 6, a subscript number is added to the end of the reference numerals 211A, 211B, 211C in order to distinguish the plurality of convex portions 211A, 211B, 211C. Unless otherwise specified, it is simply expressed without a subscript at the end, such as convex strips 211A, convex strips 211B, and 211C. It should be noted that the convex portion 211C is designated only by the one at the uppermost stage in the figure.

The ridge 211A (first convex portion) 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 convex portion) 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 welded portion 31C, and has a circular dot shape like the welded portion 31C.

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

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

The sheet materials 15a and 15b and the rubber thread 20 are conveyed by the rotation of the anvil roller 210, and are conveyed 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 thread rubber 20 are welded from the convex portions 211A, 211B, 211C on the right side. 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 horn 220 the sheet material 15a, 15b and the thread rubber 20 in this order (FIG. 4) is pressed to weld the sheet materials 15a and 15b and the rubber thread 20.

When the distance with respect to the circumferential direction C from the formation of the welded portion 30 to the formation of the next welded portion 30 exceeds the 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 convex portion 211C is not provided in the region S substantially corresponding to the absorber arrangement region S0, the welding line 31A ₁ is formed by the ridges 211A ₂ . After that, the distance Lc until the welding line 31B ₁ on the left side of the region S, which is the next welding portion 30, is formed exceeds the threshold value L ₀ , so that the sonic (ultrasonic wave) becomes unstable.

Therefore, in the region S, the convex portion 211C is provided instead of the convex strips 211A and 211B. That is, the convex portion 211C ₁ is arranged so that the shortest distance L ₁ with respect to the expansion / contraction direction W from the convex strip 211A ₂ is equal to or less than the threshold value L ₀ (L ₁ ≤ L ₀ ), and further, in the present embodiment, the convex strip. The arrangement of the convex portions 211C is set so that the shortest distance in the expansion / contraction direction W from the _211B3 and the mutual distance are each set to be equal to or less than the threshold value _L0 . With the arrangement of the convex portion 211C, the welded portion 31C is similarly arranged as described above.
The convex portion 211C (and by extension, the welding portion 31C) is provided by removing the portion where the rubber thread 20 and the sheet materials 15a and 15b overlap each other, and welds the sheet materials 15a and 15b to each other. Welding is originally performed to join the rubber thread 20 and the sheet materials 15a and 15b, and the welding is performed by removing the overlapped portion between the rubber thread 20 and the sheet materials 15a and 15b. say.
By throwing away in the region S in this way, the stability of the sonic during manufacturing is maintained.

Here, the stability of Sonic means that the fluctuation with respect to the time of the energy amount of ultrasonic vibration (hereinafter referred to as "input energy amount") input from the horn 220 to the rubber thread 20 and the sheet materials 15a and 15 is within an allowable range. It means to be inside. If the distance with respect to the expansion / contraction direction W to the next welding point is long, the amount of input energy becomes zero for a relatively long time, and the fluctuation becomes large. When the fluctuation of the input energy amount becomes large and the input of the energy amount to the rubber 20 and the sheet materials 15a and 15 becomes intermittent, the welding of the thread rubber 20 and the sheet materials 15a and 15 becomes uneven, and the thread rubber 20 and the thread rubber 20 Welding with the sheet materials 15a and 15 becomes unstable.
Therefore, a dot-shaped convex portion 211C is provided in the region S so as to suppress the fluctuation of the energy amount of the ultrasonic vibration by throwing away.

The amount of energy of ultrasonic vibration greatly depends on the area of the convex portions 211A, 211B, 211C facing the horn 220 (in other words, the area of the welded portions 31A, 31B, 31C in the gather 17).
Therefore, a long reference range A0 is set in the axial direction A, which is a predetermined area, and the “convex portion 211C ₁ in the reference area A0” with respect to the “area of the protrusions 211A ₂ in the reference area A0” in the developed view of FIG. From the ratio R of "area", it is possible to estimate the fluctuation of the energy amount of the ultrasonic vibration and, by extension, the energy amount of the ultrasonic vibration between the convex portion 211A ₂ and the convex portion 211C ₁ . The "area of the convex strip 211A ₂ in the reference area A0" and the "area of the convex portion 211C ₁ in the reference area A0" are shown by diagonal lines in FIG. 6 in the surface facing the horn 220. The area.
The minimum value of the ratio R is, for example, about 10 to 25%.

[2-3. effect]
(1) According to the present invention, since the gather 15 can be manufactured without using a hot melt material, a new gather 15 can be manufactured.
(2) In the predetermined region Sa where the dimension related to the expansion / contraction direction W is set to exceed the threshold value L and the sheet material 15a and the thread rubber 20 are not welded, instead of welding the sheet material 15a and the thread rubber 20, discarding is performed. Since it is performed, welding can be performed stably. When the predetermined region S covers the absorber placement region S0, the flexibility of the absorber placement region S0 can be suppressed from decreasing, and the fit of the absorber 10 to the wearer can be well maintained.

(3) In the gather 15, the welded wires 31A and 31B in which the rubber thread 20 is welded to the sheet materials 15a and 15b and the welded portion 31C in the region Sa where the rubber thread 20 is not welded are different in shape. Whether or not the region Sa to which the rubber thread 20 is not welded is normally formed can be easily identified by whether or not the 31C can be visually recognized. That is, the quality of the gather 15 can be easily inspected.

[3. others]

(1) In the above embodiment, the protrusions 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. The zigzag-shaped extending example has been described, but the shape of the ridges and welded wires 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. Further, the convex portion 211C and the welded portion 31C may be formed in a rectangular dot shape, or may be formed in a straight line or a zigzag shape like the convex portions 211A and 211B.

As shown in FIG. 5, the welded portion 31C may be arranged in a broken line extending in the width direction W (a plurality of welded portions 31C may be arranged at intervals in the width direction W), but in the region Sa, for example, a straight line in the width direction W. It may be in the form (may be a continuous welded part). 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 adhered, and the shape of the welded portion 31C may be linear / regular broken line / irregular broken line. You may do it.

(2) Further, in the width direction W both sides of the region Sa (the non-adhesive region between the rubber thread 20 and the sheet materials 15a and 15b) (that is, before and after the transport direction of 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 of the width direction W of the region Sa so as not to have. In this case, the rubber thread 20 may be cut at any point in the region Sa in the gather 15 (composite elastic member) in which the rubber thread 20 is bonded to the sheet materials 15a and 15b by the welding wires 31A and 31B.

The rubber thread 20 can be cut by applying a larger energy to the welded wires 31A and 31B closest to the region Sa than the other welded wires 31A and 31B, or the rubber thread 20 can be cut with the anvil roller 210. By using ridges 211A and 211B for changing the distance from the horn 220 and cutting the rubber 20, which are different from the normal ridges for forming welded wires, it is easy to apply force to the rubber thread 20. When the sheet materials 15a and 15b and the rubber thread 20 are welded, the region Sa is formed as a non-stretchable region where the elastic force of the rubber thread 20 does not act, such as by cutting the rubber thread 20. You may.

(3) In each of the above embodiments, the composite telescopic member of the present invention and the manufacturing apparatus thereof are applied to the Tammy gather 17 and its manufacturing, 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 above-mentioned elastic member can be applied to gathers provided in various absorbent articles such as pants-type disposable diapers, tape-type disposable diapers, urine pads, sanitary napkins, and panty liners, in addition to the illustrated pants-type disposable diapers.
An elastic film (elastic member) may be used in place of or in addition to the rubber thread 20 used for the elastic member. In this case, a low melting point coating layer is provided on the outer peripheral portion of the film, as in the case of the rubber thread 20 described above.

1 Paper diaper 15 Gather (composite elastic member)
15a, 15b Sheet material 16 Three-dimensional gather (composite elastic member)
17 Tammy gather (composite telescopic member)
18 Second three-dimensional gather (composite telescopic member)
20 Thread rubber (elastic member)
30, 31A, 31C Welding part 40 folds 210 Anvil roller (conveying roller)
220 horn (giving device)
211A, 211B Convex (first convex part)
211C convex part (second convex part)
213,215 Recessed L Longitudinal direction (arrangement direction of rubber thread 20)
L ₀ threshold W width direction (stretching direction of rubber thread 20)
Region where the ridges of the S anvil roller 210 are not formed Region where the welded portion 30 is not formed in the Sa Tammy gather 17 (non-welded region)

Claims (3)

It is a composite elastic member obtained by melting and welding two sheet materials and an elastic member arranged between the sheet materials by ultrasonic vibration.
The sheet material and the elastic member are not welded, and the dimensions of the elastic member in the expansion and contraction direction are stable without uneven welding. Has a non-welded region set beyond the threshold to cause
The non-welded region is characterized in that the sheet materials are welded to each other at a plurality of positions where the sheet material and the elastic member are deviated from the overlapping portion and have a mutual distance equal to or less than the threshold value. A composite elastic member. A device for manufacturing a composite stretchable member, which manufactures a composite stretchable member by welding two sheet materials and an elastic member arranged between the sheet materials while transporting them in the long direction of the sheet material. And
A transport roller that conveys the elastic member and the sheet material with the elastic member sandwiched between the two sheet materials.
The two sheet materials in which the elastic member is sandwiched are pressed between the outer peripheral surface of the transport roller, and ultrasonic vibration for melting and welding the elastic member and the sheet material is applied as energy. Equipped with a granting device
The outer peripheral surface of the transport roller is provided with a convex portion that protrudes toward the granting device.
As the convex portion, a first convex portion for welding the elastic member to the two sheet materials, respectively, and a plurality of welding the sheet materials to each other at a position separated from the portion where the sheet material and the elastic member overlap. With a second convex part of
The plurality of second convex portions have fluctuations in the amount of energy of the ultrasonic vibration within an allowable range in which the first convex portion is not formed and the dimensions of the transport roller in the circumferential direction are stable without uneven welding. An apparatus for manufacturing a composite elastic member, which is formed in a predetermined range exceeding a threshold value for suppressing and stabilizing welding, and is arranged with a mutual distance equal to or less than the threshold value. It is a method of manufacturing a composite elastic member in which two sheet materials and an elastic member arranged between the sheet materials are melted and welded by ultrasonic vibration.
The size of the elastic member in the non-welded region where the sheet material and the elastic member are not welded suppresses fluctuations in the energy amount of the ultrasonic vibration within an allowable range in which the welding is stable without unevenness. When the threshold for stabilizing welding is exceeded, the sheet material and the elastic member are located at a plurality of positions in the non-welded region where the sheet material and the elastic member are separated from each other and have a mutual distance of equal to or less than the threshold. A method for manufacturing a composite elastic member, which comprises welding sheet materials to each other.

Images