JPH11253487A - Disposable diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject diaper with gathers for legs which give no unpleasant feeling to a user by swinging a guide that inserts a plurality of elastic yarns for legs at an equal interval and reciprocates in the width direction of a continuous sheet so that it may be perpendicular to loci of the yarns provided continuously to a back sheet, thereby adhering the yarns to each other at an equal interval. SOLUTION: A guide 11a is moved by a drive mechanism constituted of an eccentric am to positions G3, G5 shown by solid lines to positions G2, G4 shown by dotted lines. The guide 11a has insertion holes 22, 222, 22 at an equal interval, and an elastic yarn 2 is inserted into each of them. The guide 11a is swung in synchronization with loci of the yarns 2. The guide 11a is forcibly changed in its angle around a support shaft 21 so that it can normally maintain its perpendicular angle to the loci of the yarn 2 provided continuously to a back sheet. With this constitution, the yarns 2 can be adhered onto a sheet with their intervals made equal normally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to disposable pants for infants or adults, and more particularly to a leg gather formed around a leg, which is gentle on the skin without causing discomfort to a wearer. It is about disposable pants.

[0002]

2. Description of the Related Art FIGS. 4 and 5 are explanatory views of disassembly of a back sheet 1 constituting a disposable pants. The back sheet 1 is in an extended state in order to fit the pants to a wearer's waist, torso and legs. Elastic yarns 2, 7, 8 are additionally provided. That is, elastic yarns 8, 8 for the waist portion are disposed at the upper and lower ends of the back sheet 1 corresponding to the waist in parallel with the waist line W, and at the portion corresponding to the circumference of the trunk between the waist and the inseam, The elastic yarns 7 for the body gathers are arranged in parallel with the elastic yarn 8 for the waist. In addition, as a leg gather to surround the base of the leg of the wearer, elasticity for the leg that curves along the half circumference of one leg opening and along the half circumference of the other leg opening while passing through the crotch. Threads 2 and 2 are attached.

The leg elastic yarn 2 is formed by a front line 2A provided on the front body side of the pants and a rear line 2B provided on the rear body side of the pants. The front body and the rear body are curved in a substantially U-shape or an inverted substantially U-shape, respectively. The front line 2A and the rear line 2B may intersect at the crotch as shown in FIG. 4 or may be arranged in parallel at the crotch as shown in FIG.

[0004] The shape of the curved line of the elastic yarn for the leg shown in Figs. 4 and 5 is adopted for continuously manufacturing disposable pants, and the elastic yarn at the crotch is clearly the leg gather. Does not work. The portion that substantially acts as the leg gather is only the elastic yarn located at the periphery of the leg opening, and is, for example, a portion indicated by Y in the drawing. Hereinafter, a range in which the attached elastic yarn 2 acts as a leg gather will be referred to as an “effective elastic range”.

FIG. 6 shows a general method for continuously attaching the elastic yarn 2 for the leg to the back sheet 1.
The continuous backsheet 1 corresponding to a state in which individual disposable pants to be separated later are arranged side by side is run in the direction of the white arrow. Reference numeral 4 denotes a guide roll, and on the upstream side of the guide roll 4, an adhesive application device (not shown) is provided, and hot melt adhesive or the like is applied to the entire surface or a part of the back sheet 1 in a mist or mesh form. Have been. If necessary, a pinch roll (not shown) that comes into contact with the guide roll 4 is provided, and the back sheet 1 with the elastic yarn 2 attached thereto.
Another sheet (not shown) is laminated on top, and the elastic yarn is quickly bonded to both sheets.

In FIG. 6, two guide rails 10 for elastic yarn are provided in parallel on the upstream side of the guide roll 4. Guides 11a and 11b that reciprocate on the guide rails 10 and 10 in a direction (sheet width direction; black arrow direction in the drawing) orthogonal to the longitudinal direction of the continuous sheet are provided. The elastic thread 2 is inserted. The traveling speed of the continuous backsheet 1 and the distance and speed of the reciprocating movement of the guide are adjusted to draw a desired attached trajectory. Elastic yarn supply rolls 12a and 12b are provided upstream of the guides 11a and 11b, and supply a constant amount of elastic yarn 2 to the guides 11a and 11b within a fixed time to adjust the elastic force. .

The elastic yarn 2 supplied from the supply rolls 12a and 12b passes through the guides 11a and 11b, comes into contact with the back sheet 1 that runs continuously on the guide roll 4, and is sequentially bonded. At this time, the elastic yarn 2 is displaced in the width direction of the sheet 1 by the reciprocating movement of the guides 11a and 11b in the sheet width direction, so that the elastic yarn 2 is adhered while drawing a curve on the continuously running back sheet. The front line 2A and the rear line 2B of FIGS. 4 and 5 are formed on the back sheet 1 in this manner. Note that reference numerals C ₁ and C ₂ in the drawing indicate virtual cutting lines, C ₂ is a cutting line for forming leg openings, and C ₁ is a cutting line for dividing individual disposable pants.

[0008]

The above guides 11a, 1a
1b reciprocates in the sheet width direction, but since the direction of this guide is fixed in the sheet traveling direction,
There is a problem that the spacing between the elastic yarns is not uniform. When the three elastic yarns are controlled by a guide so as to draw a sine curve on the continuous sheet and are added, the moving path of the guide 11a for guiding the elastic yarn 2 (G1 to G1)
G5) is schematically shown in FIG. Guide is G1, G3
And G5, the elastic yarn 2 and the guide 11a
Are substantially orthogonal to each other, and the intervals between the insertion holes of the elastic yarn 2 in the guide 11a can be secured as they are as the additional intervals d1 and d5 between the elastic yarns 2. However, when there is a guide at G2 and G4 at the intermediate position between the upper end and the lower end, the attached trajectory of the guide 11a and the elastic yarn 2 behaves obliquely. Therefore, the distance d2 between the elastic yarns 2 at the intermediate position is It becomes narrower than the attachment distance d1. Particularly in a severe case, the distance d2 is almost 0 mm, and it is as if a single thick elastic body.

As a result, regarding the effective elastic range Y of the elastic body 2 for the leg, the bonding interval between the elastic yarns 2 is small at Za on the center of the crotch and wide at Zb on the trunk side. Will be. When the adhesion interval between the elastic yarns 2 is narrowed at the crotch side, the elastic restoring force of the elastic yarns 2 is concentrated in a narrow area with respect to the wearer's skin, so that the inner portion of the soft thigh is excessively tightened. This causes red swelling and pain, resulting in poor wearing feeling.

Accordingly, a first object of the present invention is to provide disposable pants having leg gathers which prevent the elastic restoring force of the elastic yarn 2 from concentrating on a small area and do not cause discomfort.

On the other hand, focusing on the elastic restoring force in the state where the elastic yarn 2 for the leg is attached, the magnitude of the restoring force is as shown in a graph of FIG. The starting position of the guide 11a and G1, when the initial tension and T _0, the guide 1
As 1a moves in the width direction, the elastic restoring force of the elastic yarn 2 gradually increases. This is because the elastic yarn supply roll 12a on the upstream side of the guide 11a does not move, and only the guide moves laterally. As the distance from the start position G1 increases, the distance over which the elastic yarn 2 is pulled increases, and the restoring force increases. You do it. Then, the restoring force becomes maximum at the position of G3.

Therefore, considering only the effective elastic range Y of the legs in the disposable pants, the elastic restoring force is the lowest on the side of the torso Zb, and conversely the maximum on the center Za of the crotch. As described above, when the maximum and the minimum of the elastic restoring force are formed at the end of the effective elastic range Y, a portion where the elastic restoring force is abnormally high is generated at the center portion side of the crotch, and the inside of the thigh of the wearer is generated. Will be overtightened. Conversely, it is conceivable to lower the maximum value of the elastic restoring force so as not to put a burden on the skin, but doing so may cause the minimum value of the elastic restoring force to be extremely reduced, and gathers may not be formed at this part. is there. If the start point is G3, the minimum and maximum occurrence positions are reversed.

Therefore, a second object of the present invention is to prevent the elastic restoring force of the elastic yarn in the leg gathers from being excessively large in part, thereby preventing the wearer from feeling discomfort such as pain and swelling. It is to provide disposable pants.

[0014]

According to the present invention, which has attained the first object, a plurality of elastic yarns for leg portions are attached to a back sheet or a top sheet, and the plurality of elastic yarns are used for the front side and the under side of the pants. In the disposable pants in which the front line and the rear line curved to the rear side are respectively configured, the guide for inserting the plurality of elastic yarns at equal intervals and reciprocating in the continuous sheet width direction is applied to the trajectory of the elastic yarns. The gist is such that the plurality of elastic yarns are equally bonded by being swung so as to be always perpendicular to the plurality of elastic yarns.

The present invention, which has achieved the second object, is characterized in that a plurality of elastic yarns for legs are attached to a back sheet or a top sheet, and the plurality of elastic yarns are bent to the front and rear sides of the pants. In the disposable pants in which the line and the rear line are respectively configured, the guide for inserting the plurality of elastic yarns and reciprocating in the sheet width direction starts from substantially the center in the sheet width direction and moves in the left and right width direction. Thus, the gist lies in that the elastic restoring force in the effective elastic range of the front line and the rear line is substantially uniformly arranged.

In a further preferred embodiment, both of the above-mentioned two requirements are satisfied, the plurality of elastic yarns are bonded at equal intervals, and the elastic restoring force in the effective elastic range of the front line and the rear line is substantially uniform. Is to be done.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a disposable pants, in which a back sheet or a top sheet is provided with at least elastic yarns for legs, the elastic yarns being composed of a plurality of lines, and a front side and a rear side of the disposable pants. To form a U-shaped or inverted U-shaped front line and a rear line. In order to continuously form the front line and the rear line, a guide that reciprocates in the width direction of the continuously traveling sheet is provided, and elastic yarns are respectively passed through a plurality of insertion holes formed in the guide, and the traveling of the sheet is performed. Then, the front line and the rear line are continuously formed by laterally moving the guide.

Further, the guide is configured to be swingable so that the angle can be changed, so that the lateral movement of the guide and the change of the angle of the guide can be performed in synchronization with each other. The angle is changed so that it is always orthogonal to the attached locus of the elastic yarn. As a result, the insertion holes are always in a state of being parallel to the attached trajectories of the elastic yarns, and the intervals of the attached elastic yarns can always be uniform (they are adhered according to the arrangement intervals of the insertion holes). Therefore, the elastic restoring force of the plurality of elastic yarns is distributed over a wide area, and does not concentrate on a part around the leg of the wearer, and does not cause pain or swelling.

In the front line and the rear line, the range that acts as a leg gather is limited to the effective elastic range. In order to make the elastic restoring force of the elastic yarns provided in this range substantially uniform, the guide is used. Start position is substantially at the center in the sheet width direction. At this time, naturally, the supply roll of the elastic yarn, which is arranged on the upstream side of the guide, is arranged substantially at the center in the sheet width direction at the same position as the guide start position. The lateral pulling distance of the elastic yarn caused by the lateral movement of the guide is only half of the guide stroke,
The difference in elastic restoring force from the start position can be made as small as possible. Although the elastic restoring force of the attached elastic yarn is slightly weakened at the start position, the difference between the maximum value and the minimum value can be reduced, and the elastic restoring force can be made substantially uniform particularly in the effective elastic range around the leg. .

The reduction in the elastic restoring force of the elastic yarn caused by the lateral movement of the guide can be easily adjusted by reducing the supply amount of the elastic yarn in the supply roll provided on the upstream side of the guide.

If the elastic restoring force of the elastic yarn becomes uniform around the leg, the pain and swelling of the wearer caused by the restoring force being concentrated in one place can be prevented.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to obtain an embodiment having the requirements of the present invention, the manufacturing means shown in FIG. 6 is used. Guide 11
a is swingably arranged on the guide rail 10 via the support shaft 21 as shown in FIG. The guide 11a is moved from a position G1 (G3, G5) shown by a solid line to G2, G4 shown by a broken line by a drive mechanism constituted by an eccentric cam (not shown).
Operate to position. The guide holes 11 are provided at equal intervals in the guide 11a.
2, 22, 22 are arranged, and the elastic thread 2 is inserted through these one by one.

That is, as shown in FIG. 1, the guide 11a is moved from G1 to G5 in accordance with the lateral movement.
The elastic yarn is swung in synchronization with the attached locus as shown in FIG.
In FIG. 1, the attached trajectory of the elastic yarn 2 draws a sinusoidal curve, and the guide 11a reciprocates in the vertical direction (the width direction of the back sheet) in the figure. At this time, the guide 11a is forcibly rocked (angle-changed) about the support shaft 21 by the driving mechanism so that the guide 11a can always maintain an angle orthogonal to the attached locus of the elastic yarn 2 (FIG. 2).

With this configuration, the elastic yarns 2, 2, 2 can be adhered onto the sheet while keeping the intervals between them constant, so that the intervals do not become narrow in a part as in the conventional product in FIG. . Therefore, the adhesive interval between the elastic yarns 2 is reduced, and the elastic restoring force is concentrated in a narrow area with respect to the wearer's skin,
Red swelling and pain were prevented from occurring.
The driving mechanism for swinging the guide 11a is as follows.
The present invention is not limited to the eccentric cam, but may be a device using a rack / pinion, a return cylinder, a servomotor, or the like.

FIG. 3 is a graph showing the relationship between the lateral movement position of the guide 11a and the elastic restoring force of the elastic yarn 2.
In order to achieve the configuration of claim 2 of the present invention, a guide 11a
Start position is center position G3 of reciprocating stroke S
Set to. At this time, the supply roll 12a disposed upstream of the guide 11a is disposed substantially at the center in the sheet width direction, similarly to the guide start position. When the initial tension in the start position as T _1, the elastic restoring force of the elastic yarn by the lateral movement of the guide 11a is the maximum value at both ends of the stroke changes. Difference between the maximum value and the minimum value is T _2.

As is apparent from comparison with FIG. 8 showing a conventional example, T ₂ in the present invention is only half of T _M because the lateral movement distance from the start position of the guide is reduced to half. As a result, the difference between the maximum and the minimum of the elastic restoring force of the elastic yarn 2 can be significantly reduced. By adjusting the supply amount of the elastic yarn 2 to the supply rolls 12a and 12b so as not to reduce the overall elastic restoring force of the elastic yarn 2 (reducing the supply amount within a unit time), the initial tension T ₁ is reduced. The problem can be solved by raising the height compared to T ₀ .

In the embodiment of the present invention shown in FIG.
Has almost no difference in elastic restoring force at both ends Za and Zb of the effective elastic range Y, and it is possible to form a substantially uniform elastic restoring force as the elastic body of the leg gathers.

As described in detail above, since the elastic restoring force of the attached leg elastic yarn 2 is more uniform in the effective elastic range Y than that of the conventional product, it is caused by the elastic restoring force being concentrated on a part. It does not cause discomfort such as pain or swelling to the wearer, and can achieve a skin-friendly wearing feeling.

In the present invention, if both the structure of claim 1 in which the adhesion interval of the elastic yarn 2 is uniform and the structure of claim 2 in which the elastic restoring force of the elastic yarn 2 is substantially uniform are worn, Leg gathers can be formed so as to gently seal around the legs of the user, and the wearing feeling can be further improved.

The elastic yarn 2 may be either one attached to one sheet or one in which the elastic yarn 2 is provided between two layers of sheets. This is a bag forming a disposable pants. Either a sheet or a top sheet, or a sheet disposed on another sheet provided between these sheets may be used. Further, the means for bonding the elastic yarn to the sheet is not limited to the method in which the adhesive is applied to the sheet in advance as described above, and the method for applying the adhesive to the elastic yarn and bonding the adhesive to the sheet may also be used. good.

[0031]

According to the structure of the first aspect of the present invention, a plurality of elastic yarns are adhered at equal intervals at the base of the wearer's leg and spread in a plane to abut against the wearer's skin. The elastic restoring force acts partially linearly to prevent inconvenience such as causing red swelling and pain on the skin. Further, if the configuration of claim 2 is adopted, the problem that the elastic restoring force of the elastic yarn becomes uneven at the trunk side portion and the crotch portion and only a part of the elastic yarn is strongly tightened can be solved, and almost uniformly around the leg base. It is possible to provide a customer gather that works and has an excellent feeling of wearing. By combining the above two effects, it is possible to provide a more gentle leg gather for the wearer.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an arrangement state of a leg elastic yarn according to the present invention.

FIG. 2 is an explanatory plan view showing an embodiment of a guide configuration for achieving the configuration of FIG. 1;

FIG. 3 is a graph showing the elastic restoring force of the elastic yarn in the present invention.

FIG. 4 is an explanatory view showing an example of a back sheet structure of disposable pants.

FIG. 5 is an explanatory view showing an example of a back sheet structure of disposable pants.

FIG. 6 is an explanatory view showing a configuration of a means for attaching an elastic thread for a leg.

FIG. 7 is an explanatory view showing a bonding state of a conventional leg elastic thread.

FIG. 8 is a graph showing the state of elastic restoring force of a conventional leg elastic yarn.

[Explanation of symbols]

1 backsheet second leg elastic yarns 2A of the previous line 2B after line 4, 5 guide rolls 7 elastic yarn 8 barrel for the side elastic yarn 10 guide rails 11a, 11b guide 12a, 12b supply roll C _1, C ₂ cut line G1~G5 guide position S stroke Y effective elastic range

Claims (3)

[Claims] 1. A plurality of elastic yarns for leg portions are attached to a backsheet or a topsheet, and a front line and a rear line curved to the front and rear sides of the pants are respectively constituted by the plurality of elastic yarns. In the disposable pants, the guide for inserting the plurality of elastic yarns at equal intervals and reciprocating in the continuous sheet width direction is swung so that the guide is always perpendicular to the trajectory of the elastic yarns. Disposable pants, wherein the elastic yarns are equally spaced from each other. 2. A back sheet or a top sheet is provided with a plurality of elastic yarns for leg portions, and the plurality of elastic yarns form a front line and a rear line, respectively, curved to the front and rear sides of the pants. In the disposable pants, the guide for allowing the plurality of elastic yarns to pass through and reciprocate in the sheet width direction starts from substantially the center of the sheet width direction and moves in the left and right width direction, so that the front line and the rear line are effective. Disposable trousers characterized in that the elastic restoring force in the elastic range is arranged almost uniformly. 3. A back sheet or a top sheet is provided with a plurality of elastic yarns for leg portions, and the plurality of elastic yarns constitute a front line and a rear line, respectively, curved frontward and rearward of the pants. In the disposable pants, the guide that inserts the plurality of elastic yarns at equal intervals and reciprocates in the continuous sheet width direction is swung so as to be always perpendicular to the trajectory of the elastic yarns, Starting from approximately the center of the line and moving it in the left-right width direction, the intervals between the plurality of elastic yarns are bonded equally, and the elastic restoring force in the effective elastic range of the front line and the rear line is almost evenly arranged. Disposable pants, characterized by the fact that they are made.