JP2020054742A - Manufacturing method of stretchable sheet and manufacturing apparatus of stretchable sheet - Google Patents

Abstract

To suppress cut of a rubber thread when forming a bonding part of a sheet by using a pressure roller whose outer peripheral surface is rugged and a crimping part.SOLUTION: A manufacturing method (10) of a stretchable sheet supplies a rubber thread (14) at a supply angle position of a pressure roller (25) having a rugged surface, puts a first sheet part (11) and the rubber thread (14) between the pressure roller (25) and a press roller (23), puts the first sheet part (11) and a second sheet part (12) via the rubber thread (14) between the pressure roller (25) and a crimping part (26), bonds the first sheet part (11) and the second sheet part (12), forms a plurality of bonding parts that regulate positions of the rubber thread (14) in a stretching direction, and makes an angle difference between a pressure angle position and a supply angle position equal to or below an angle difference between the pressure angle position and a bonding angle position.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for manufacturing a stretchable sheet and a manufacturing apparatus for a stretchable sheet.

  As a method of manufacturing an elastic sheet, a method of attaching a stretched thread rubber between sheets with an adhesive is known. On the other hand, in Patent Document 1, a thread rubber (wire-like element) in an extended state is disposed between sheets, and the sheet is pressed between a pair of rollers to press the sheet and to cross the thread rubber. A method for forming a connection portion on both sides of the device is disclosed. In a narrow portion formed between the connection portions on both sides of the thread rubber, the thread rubber in a state where tension is lost can be fixed, and the thread rubber can be attached to the sheet. Thus, by attaching the thread rubber to the sheet without using the adhesive, it is possible to suppress a decrease in the shrinkage performance of the thread rubber and a decrease in the flexibility of the stretchable sheet due to the curing of the adhesive.

Japanese Patent No. 3212615

  However, in Patent Literature 1, the sheet and the thread rubber are not wound around the rollers but are supplied linearly between the pair of rollers. Therefore, the position of the thread rubber in the rotation axis direction is not stable, and the thread rubber is easily supplied between the pair of rollers in a state where the thread rubber is not settled in the groove between the protrusions arranged in the rotation axis direction. In this case, the rubber thread is cut.

  The present invention has been made in view of the above problems, and when forming a joint portion of a sheet using a pressing roller and a pressing portion having an uneven outer peripheral surface, the cutting of thread rubber. The purpose is to control.

A main invention for achieving the above object is a method for manufacturing a stretchable sheet in which a first sheet portion and a second sheet portion are laminated with thread rubber interposed therebetween, and a pressure roller having an outer peripheral surface having an uneven surface. Supplying the rubber thread to the pressure roller so that the rubber thread is located outside the first sheet portion in the radial direction of the pressure roller at a supply angle position in the rotation direction of the pressure roller; And pressing the first sheet portion at a pressing angle position in the rotation direction by passing the first sheet portion and the thread rubber between a press roller contacting the pressure roller. By passing the first sheet portion and the second sheet portion with the thread rubber between a pressure roller and a pressure portion that contacts the pressure roller, At the joining angle position in the rotation direction, a plurality of joining portions that press and join the first sheet portion and the second sheet portion and join each other, and the plurality of joining portions regulate a position of the thread rubber in a stretching direction. Forming a joining portion, wherein the angle difference between the pressing angle position and the supply angle position is equal to or less than the angle difference between the pressing angle position and the joining angle position. This is a sheet manufacturing method.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  According to such a method for manufacturing a stretchable sheet, cutting of the rubber thread can be suppressed when a bonding portion of the sheet is formed by using a pressing roller and a pressing portion having an uneven outer peripheral surface.

It is a top view of the elastic sheet 10 manufactured by the manufacturing method of this embodiment. It is a schematic sectional drawing of the elastic sheet 10 of FIG. FIG. 3A is a schematic perspective view of the pants-type disposable diaper 1 using the elastic sheet 10, and FIG. 3B is a schematic plan view of the pants-type disposable diaper 1 in the expanded state and the extended state as viewed from the skin side. It is an outline sectional view of manufacturing device 20 of an elastic sheet in a 1st embodiment. FIG. 5A is an explanatory view of the surface of the anvil roller 25 and the horn roller 26, and FIG. 5B is a schematic enlarged view of the closest part between the anvil roller 25 and the horn roller 26. 6A and 6B are explanatory diagrams of a method of attaching the thread rubber 14 by the joint j. 7A and 7B are explanatory diagrams of the supply direction of the thread rubber 14. FIG. FIG. 9 is an explanatory diagram of an arrangement of a third transport roller 213. It is a schematic sectional drawing of the manufacturing apparatus 20 of a stretchable sheet in 2nd Embodiment.

At least the following matters will be made clear by the description in the present specification and the accompanying drawings.
A method of manufacturing an elastic sheet in which a first sheet portion and a second sheet portion are laminated with thread rubber interposed therebetween, wherein the pressing is performed at a supply angle position in a rotation direction of a pressing roller having an uneven outer peripheral surface. A step of supplying the thread rubber to the pressure roller so that the thread rubber is located outside the first sheet portion in the radial direction of the roller, and the pressure roller, and a press roller that contacts the pressure roller. Pressing the first sheet portion at the pressing angle position in the rotation direction by passing the first sheet portion and the thread rubber between, and pressing the pressing roller and the pressing roller in contact with the pressing roller. By passing the first sheet portion and the second sheet portion with the thread rubber interposed therebetween, the joint angle position in the rotation direction is reduced. Forming a plurality of joints for pressing and bonding the first sheet portion and the second sheet portion to each other and for regulating a position of the thread rubber in the direction of expansion and contraction; Wherein the angle difference between the pressing angle position and the supply angle position is equal to or less than the angle difference between the pressing angle position and the joining angle position.

  According to such a method for manufacturing a stretchable sheet, on the upstream side of the press roller, the thread rubber can be wrapped tightly around the curved surface of the pressure roller and move in a direction intersecting the stretch direction without being closely attached. Therefore, the thread rubber can enter the groove of the pressure roller, and it can be suppressed that the thread rubber is cut at the time of forming the joint.

  In the method for manufacturing a stretchable sheet, the first sheet portion is supplied to the pressure roller at a second supply angle position in the rotation direction, and a position between the pressing angle position and the second supply angle position is determined. The angle difference is not more than the angle difference between the pressing angle position and the joining angle position.

  According to such a method for manufacturing a stretchable sheet, the first sheet portion is bent into the groove of the pressure roller without the first sheet portion being tightly wound around the curved surface of the pressure roller and closely attached to the upstream side of the press roller. It becomes easy to put in. Therefore, the thread rubber can enter the groove, and it is possible to suppress the thread rubber from being cut when the joint is formed.

  In the method for manufacturing such an elastic sheet, an outer peripheral surface of the pressure roller, which is a range from a tangent drawn from the rotation center of the pressure roller to the press roller to the pressing angle position in the rotation direction, or A method for producing an elastic sheet, comprising supplying the thread rubber to an outer peripheral surface of the press roller.

  According to such an elastic sheet manufacturing method, the rubber thread can move in a direction intersecting the elastic direction on the upstream side of the press roller. Therefore, the thread rubber can enter the groove of the pressure roller, and it can be suppressed that the thread rubber is cut at the time of forming the joint.

  A method for producing such an elastic sheet, wherein the rubber thread is supplied to an outer peripheral surface of the pressure roller in the above-mentioned range.

  According to such a method for manufacturing a stretchable sheet, the time margin for the rubber thread to move on the outer peripheral surface of the pressure roller increases on the upstream side of the press roller. Therefore, the thread rubber can enter the groove of the pressure roller, and it can be suppressed that the thread rubber is cut at the time of forming the joint.

  A method for manufacturing such an elastic sheet, wherein the first sheet portion is also supplied to the outer peripheral surface of the pressure roller in the above range.

  According to such a method for manufacturing a stretchable sheet, the first sheet portion is bent into the groove of the pressure roller without the first sheet portion being tightly wound around the curved surface of the pressure roller and closely attached to the upstream side of the press roller. It becomes easy to put in. Therefore, the thread rubber can enter the groove, and it is possible to suppress the thread rubber from being cut when the joint is formed.

  The method for producing an elastic sheet, wherein the second sheet part is passed between the pressure roller and the press roller together with the first sheet part and the rubber thread. It is a manufacturing method.

  According to such an elastic sheet manufacturing method, the second sheet portion is supplied onto the thread rubber that has entered the groove portion of the pressure roller, and is pressed by the press roller. Therefore, the state in which the thread rubber has entered the groove is maintained, and it is possible to suppress the thread rubber from being cut during the formation of the joint.

  In this method for producing an elastic sheet, using a transport roller, the thread rubber is supplied to the pressure roller, and in a range from the pressing angle position to the joining angle position in the rotation direction, the pressing roller is When the length of the thread rubber to be wound is length L1, the length of the thread rubber transported from the transport roller to the pressing angle position is longer than the length L1. This is a method for producing a stretchable sheet.

  According to such an elastic sheet manufacturing method, since the transport roller is disposed apart from the press roller, the rubber thread can move in a direction intersecting the stretch direction between the transport roller and the press roller. Therefore, the thread rubber can enter the groove of the pressure roller, and it can be suppressed that the thread rubber is cut at the time of forming the joint.

  In the method for manufacturing an elastic sheet, the outer peripheral surface of the press roller is formed of an elastic material.

  According to such an elastic sheet manufacturing method, the press roller can firmly adhere to the pressure roller (convex portion) via the first and second sheet portions, and the first and second sheet portions and the thread rubber are formed. The position is fixed firmly.

  Further, the present invention is an apparatus for manufacturing a stretchable sheet in which a first sheet portion and a second sheet portion are laminated with thread rubber interposed therebetween, and at a supply angle position in a rotation direction of a pressure roller having an uneven outer peripheral surface, A supply unit that supplies the rubber thread to the pressure roller, the pressure roller, and the pressure roller so that the rubber thread is located outside the first sheet portion in the radial direction of the pressure roller. A pressing portion that presses the first sheet portion at a pressing angle position in the rotation direction by passing the first sheet portion and the rubber thread between the pressing roller, the pressing roller, and the pressing roller By passing the first sheet portion and the second sheet portion with the thread rubber interposed between the pressing portion and the crimping portion that comes into contact with the pressing portion, the joining angle in the rotation direction is increased. A plurality of joints for pressing and bonding the first sheet portion and the second sheet portion to each other, and forming the plurality of joints for restricting the position of the rubber thread in the direction of expansion and contraction. Manufacturing a stretch sheet, wherein an angle difference between the pressing angle position and the supply angle position is equal to or less than an angle difference between the pressing angle position and the joining angle position. Device.

  According to such a stretch sheet manufacturing apparatus, the thread rubber can move in the direction intersecting the stretch direction without being tightly wound around the curved surface of the pressure roller on the upstream side of the press roller. Therefore, the thread rubber can enter the groove of the pressure roller, and it can be suppressed that the thread rubber is cut at the time of forming the joint.

=== embodiment ===
<< Configuration of Elastic Sheet 10 >>
FIG. 1 is a plan view of an elastic sheet 10 manufactured by the manufacturing method (manufacturing apparatus) of the present embodiment. FIG. 1 is a view showing a state in which the elastic sheet 10 is stretched without wrinkles. FIG. 2 is a schematic sectional view of the elastic sheet 10 of FIG.

  The elastic sheet 10 has an elastic direction, a thickness direction, and a width direction orthogonal to each other. Further, the elastic sheet 10 has a first sheet portion 11 and a second sheet portion 12 stacked in the thickness direction, and a plurality of elastic sheets interposed between the first sheet portion 11 and the second sheet portion 12. It has a thread rubber 14 and a plurality of joints j.

  The plurality of thread rubbers 14 are arranged along the width direction while being spaced along the direction in which the elastic sheet 10 expands and contracts. The thread rubber 14 is attached to the first sheet portion 11 and the second sheet portion 12 in an extended state. Therefore, the elastic sheet 10 is provided with elasticity in the direction along the rubber thread 14. As the thread rubber 14 (thread-like elastic member), various known synthetic rubbers such as styrene-based rubber, urethane-based rubber, ester-based rubber, polyurethane, and polyethylene can be applied in addition to thread-like natural rubber.

  The plurality of joining portions j are for joining the first sheet portion 11 and the second sheet portion 12 by crimping and joining each other, and are intermittently arranged in the stretching direction and the width direction of the stretchable sheet 10. . The plurality of joints j regulate the position of the rubber thread 14 in the expansion and contraction direction with respect to the first sheet portion 11 and the second sheet portion 12. As will be described in detail later, the position of the thread rubber 14 is regulated by a pair of joints jP formed on both sides of the thread rubber 14 in the width direction so as to form a pair. The planar shape of the joint j illustrated in FIG. 1 is rectangular, but the planar shape of the joint j is not particularly limited, and an arbitrary shape such as an ellipse, a circle, a parallelogram, or the like can be adopted.

  Although the elastic sheet 10 in FIG. 2 is composed of two sheets, for example, one sheet is folded, the folded part is a first sheet part, and the unfolded part is a second sheet. It may be a part. Moreover, the elastic sheet 10 in which one or a plurality of different sheet portions are stacked on the first and second sheet portions 11 and 12 may be used. That is, the elastic sheet 10 may have three or more layers.

<< Example of use of elastic sheet 10 >>
FIG. 3A is a schematic perspective view of the pants-type disposable diaper 1 using the elastic sheet 10. FIG. 3B is a schematic plan view of the pants-type disposable diaper 1 in the unfolded state and the stretched state as viewed from the skin side. The elastic sheet 10 manufactured by the manufacturing method (manufacturing apparatus) of the present embodiment is used as a component of an absorbent article such as a disposable diaper.

  The illustrated pants-type disposable diaper 1 (hereinafter also referred to as “diaper”) includes an absorbent main body 2 that absorbs and retains excrement, an abdominal waist portion 3 applied to a wearer's abdomen, and a back of the wearer. And a back side waist portion 4 applied to the portion. As shown in the unfolded state of FIG. 3B, the central portion in the left-right direction of the abdominal waistline portion 3 overlaps one end in the longitudinal direction of the absorbent main body 2, and the other end in the longitudinal direction of the absorbent main body 2 is provided. The center part of the back waist part 4 in the left-right direction overlaps the end part. The unfolded diaper 1 is folded in two substantially at the center in the longitudinal direction, and the left and right sides of the abdominal waistline portion 3 and the left and right sides of the back waistline portion 4 are joined by welding or the like. The diaper 1 is of a pants type.

  The abdominal waist portion 3 and the back waist portion 4 are substantially rectangular members in plan view, and a plurality of thread rubbers 5 that expand and contract in the left-right direction of the diaper 1 are arranged at intervals in the up-down direction. . Therefore, the abdominal waist part 3 and the back waist part 4 can expand and contract in the left-right direction of the diaper 1 and fit around the wearer's waist. The stretchable sheet 10 can be used for the abdominal waistline 3 and the back waistline 4. The stretching direction of the elastic sheet 10 corresponds to the left-right direction of the diaper 1, and the width direction of the elastic sheet 10 corresponds to the up-down direction of the diaper 1.

  When the elastic sheet 10 is used as a component of an absorbent article, a soft sheet member can be exemplified as the first sheet portion 11 and the second sheet portion 12 constituting the elastic sheet 10. For example, it is a nonwoven fabric such as a spunbonded nonwoven fabric and an SMS (spunbond / meltblown / spunbond) nonwoven fabric. Further, at least one of the first sheet portion 11 and the second sheet portion 12 may be a stretchable sheet (a stretchable film or a stretchable nonwoven fabric) that can be stretched in the stretchable direction of the stretchable sheet 1. Further, an elastic film or an elastic nonwoven fabric may be interposed between the first sheet portion 11 and the second sheet portion 12.

  Further, the elastic sheet 10 is not limited to being used for the abdominal waistline 3 and the back waistline 4. For example, the elastic sheet 10 can be used in leg gather portions provided on both sides of the absorbent body in the left-right direction of the diaper so that the disposable diaper fits around the wearer's leg. Since the leg gathers extend and contract in the longitudinal direction of the absorbent main body, the longitudinal direction of the absorbent main body corresponds to the extension and contraction direction of the elastic sheet 10.

  Further, in a tape-type disposable diaper (not shown), a fastening tape (hook member) extends from the back waist portion to both outer sides in the left-right direction. The elastic sheet 10 can be used for a side panel for attaching the fastening tape to the back waistline. Since the side panel expands and contracts in the left-right direction of the diaper, the left-right direction of the diaper corresponds to the expansion and contraction direction of the elastic sheet 10.

  The elastic sheet 10 is not limited to pants-type or tape-type disposable diapers, but can also be used as a component of absorbent articles such as pad-type disposable diapers, sanitary napkins, and sanitary shorts-type napkins. is there. In addition, it can be used not only for absorbent articles but also for masks, cleaning sheets, and the like.

=== Stretching Sheet Manufacturing Apparatus and Method ===
<< 1st Embodiment >>
(Structure of elastic sheet manufacturing apparatus 20)
FIG. 4 is a schematic sectional view of the stretch sheet manufacturing apparatus 20 according to the first embodiment. FIG. 5A is an explanatory diagram of the surfaces of the anvil roller 25 and the horn roller 26. FIG. 5B is a schematic enlarged view of the closest part between the anvil roller 25 and the horn roller 26. 6A and 6B are explanatory diagrams of a method of attaching the thread rubber 14 by the joint j. 7A and 7B are explanatory diagrams of the supply direction of the thread rubber 14. FIG. 8 is an explanatory diagram of the arrangement of the third transport roller 213.

  The stretch sheet manufacturing apparatus 20 includes a transport roller group 21, an ultrasonic welding device 22, a press roller 23, and a discharge roller 24. The elastic sheet 10 is manufactured as a continuous sheet that is continuous in the expansion and contraction direction. In the elastic sheet manufacturing apparatus 20, a direction in which the materials are continuous is defined as a transport direction, and a direction perpendicular to the transport direction (ie, the width direction of the elastic sheet 10 and the materials) is defined as a CD direction.

  The transport roller group 21 is disposed upstream of the ultrasonic welding device 22 in the transport direction, and transports the material forming the elastic sheet 10 and supplies it to the ultrasonic welding device 22. Specifically, the transport roller group 21 includes a first transport roller 211 that transports a continuum of the first sheet unit 11, a second transport roller 212 that transports a continuum of the second sheet unit 12, and a thread rubber 14. And a third transport roller 213 that transports a plurality of continuous bodies.

  The first to third transport rollers 211 to 213 are rotated around a rotation axis along the CD direction by a drive source (for example, a motor) not shown. The first to third transport rollers 211 to 213 may be a pair of rollers or a single roller. Further, the material may be supplied to the ultrasonic welding device 22 by a belt conveyor or the like.

  Hereinafter, the continuum of the first sheet portion 11, the continuation of the second sheet portion 12, the continuation of the thread rubber 14, and the continuation of the elastic sheet 10 will be simply referred to as the first sheet portion 11, the second sheet portion 12, Also referred to as thread rubber 14 and elastic sheet 10.

  The ultrasonic welding device 22 (joining portion forming portion) is for forming the joining portion j of the stretchable sheet 10, and comes into contact with the anvil roller 25 (pressing roller) and the anvil roller 25 that are arranged to face each other. It has a horn roller 26 (pressure bonding part). The anvil roller 25 and the horn roller 26 rotate around a rotation axis along the CD direction by a drive source (not shown). Note that the anvil roller 25 and the horn roller 26 need only be capable of contacting via at least a material passing therethrough, and are preferably capable of contacting with no material.

  As shown in FIG. 5A, the outer peripheral surface of the anvil roller 25 is an uneven surface on which a plurality of convex portions 251 are formed. The projections 251 together with the horn roller 26 ultrasonically weld a material to form a joint j. Therefore, the protrusions 251 are arranged corresponding to the arrangement pattern of the joints j in the elastic sheet 10.

  The outer peripheral surface of the horn roller 26 is a smooth surface having no irregularities, and vibrates in a direction in which the distance between the horn roller 26 and the surface of the anvil roller 25 is expanded or contracted (that is, the thickness direction of the material passing therethrough). The frequency of the vibration is, for example, a predetermined value of 20 kHz to 40 kHz, and the amplitude is, for example, a predetermined value of 20 μm to 30 μm. Therefore, the surface of the horn roller 26 vibrates ultrasonically. Such vibration is generated by inputting an electric signal of the above-described frequency to a piezo element of a converter (not shown) connected to the horn roller 26.

  Further, the first and second sheet portions 11 and 12 and the rubber thread 14 pass between the anvil roller 25 and the horn roller 26 after being wound around the anvil roller 25. The peripheral speed values of the first and second transport rollers 211 and 212 for transporting the first and second sheet portions 11 and 12 are substantially the same as the peripheral speed value of the anvil roller 25, respectively. Therefore, the first and second sheet portions 11 and 12 are wound around the anvil roller 25 in a state where the first and second sheet portions 11 and 12 are stretched to such a degree that they are not substantially stretched and are not loosened.

  On the other hand, the peripheral speed value of the third transport roller 213 that transports the thread rubber 14 is about one-half the extension speed of the peripheral speed value of the anvil roller 25. The extension ratio is a ratio R (R = E1 / E0) indicating how many times the total length E1 of the thread rubber 14 in the stretched stretchable sheet 10 is extended to the total length E0 in the unloaded state, which is a natural length. . Therefore, the thread rubber 14 is stretched to the above-described stretching magnification while passing between the fourth transport roller 214 and the anvil roller 25, and is wound around the anvil roller 25 in the stretched state.

  The press roller 23 is a roller disposed so as to be in contact with the outer peripheral surface of the anvil roller 25 upstream of the horn roller 26 in the transport direction. The press roller 23 is rotated around a rotation axis along the CD direction by a driving source (not shown). In addition, the press roller 23 should just be able to contact via the material which passes between at least, Preferably it is good to be able to contact in the state without a material.

  The discharge roller 24 is a roller that discharges the manufactured elastic sheet 10 to a downstream process. The discharge roller 24 is rotated around a rotation axis along the CD direction by a drive source (not shown).

(Manufacturing method of elastic sheet 10)
In the method of manufacturing the stretchable sheet 10 by the manufacturing apparatus 20 having the above configuration, first, the transport roller group 21 (supply unit) supplies the first and second sheet units 11 and 12 and the thread rubber 14 to the anvil roller 25. Specifically, the first sheet portion 11 is supplied to the anvil roller 25 at the second supply angle position P2 in the rotation direction of the anvil roller 25. Next, the thread rubber 14 is supplied to the anvil roller 25 at a supply angle position P1 downstream of the second supply angle position P2 in the rotation direction of the anvil roller 25. Therefore, the rubber thread 14 is located outside the first sheet portion 11 in the radial direction of the anvil roller 25.

  Next, by passing the first sheet portion 11 and the second sheet portion 12 with the thread rubber 14 interposed between the anvil roller 25 and the press roller 23 (pressing portion), the pressing angle in the rotation direction of the anvil roller 25 is increased. At the position P3, the first sheet unit 11 and the second sheet unit 12 are pressed. The second sheet portion 12 is conveyed while being wound around the press roller 23, and is passed between the anvil roller 25 and the press roller 23.

  The outer peripheral surface of the press roller 23 is a smooth surface having no irregularities, and the press roller 23 contacts the convex portion 251 of the anvil roller 25. When the first and second sheet portions 11 and 12 and the thread rubber 14 pass between the press roller 23 and the anvil roller 25, the first and second sheet portions 11 and 12 form the convex portions 251 of the anvil roller 25. Is pressed by the press roller 23 at a position corresponding to. At this time, the thread rubber 14 is located in the groove 252 (see FIGS. 5A and 5B) between the protrusions 251 adjacent in the CD direction on the outer peripheral surface of the anvil roller 25, and is not pressed. In FIG. 4, the thread rubber 14 is located on the convex portion 251 of the anvil roller 25 for easy understanding of the drawing. However, the thread rubber 14 is actually located in the groove 252.

  Further, when pressed by the press roller 23, the first sheet portion 11, the second sheet portion 12, and the rubber thread 14 are not joined to each other. Specifically, the adhesive is not applied to the first and second sheet portions 11 and 12 and the thread rubber 14, and the first and second sheet portions 11 and 12 are in a state where they are not pressed against each other. I do.

  Next, by passing the first sheet portion 11 and the second sheet portion 12 with the thread rubber 14 interposed between the anvil roller 25 and the horn roller 26, at the joining angle position P4 in the rotation direction of the anvil roller 25, The first sheet portion 11 and the second sheet portion 12 are joined together by ultrasonic welding (compression bonding) to form a plurality of joints j. Thus, the elastic sheet 10 is manufactured.

  Specifically, the first and second sheet portions 11 and 12 are melted by ultrasonic vibration from the horn roller 26 at positions corresponding to the convex portions 251 of the anvil roller 25, and are joined. At this time, the thread rubber 14 is located in the groove 252 of the anvil roller 25 and is not subjected to ultrasonic welding.

  Further, as described above, the plurality of joints j serve to regulate the position of the thread rubber 14 in the expansion and contraction direction with respect to the first sheet portion 11 and the second sheet portion 12, that is, the first and second sheets j. It also plays a role of attaching the thread rubber 14 to the seat portions 11 and 12.

  For this purpose, in the present embodiment, as shown in FIG. 6A, in the CD direction, the interval Dj between the joining portion pair jP located on both sides of the thread rubber 14 is set to the value of the thread rubber 14 extending at the time of forming the joining portion j. It is assumed that the dimension D14 in the CD direction is equal to or larger than the dimension D14. Further, it is assumed that the interval Dj is smaller than the size of the thread rubber 14 in the CD direction in the naturally long unloaded state. The stretched rubber thread 14 is thinner than the natural thread rubber 14 by the length of the stretched rubber thread. Therefore, when the stretched state of the thread rubber 14 is relaxed by cutting the continuum of the thread rubber 14 after the formation of the joint j, as shown in FIG. The thread rubber 14 to be expanded in the direction can be pressed by the joint portion pair jP from the CD direction. As a result, the position of the thread rubber 14 in the direction of expansion and contraction is regulated, and the thread rubber 14 is attached to the sheet portion.

  In addition, the interval Dj between the joint portion pair jP may be smaller than the CD-direction size D14 of the thread rubber 14 extending at the time of forming the joint portion j. That is, the joint j may be formed while the thread rubber 14 is compressed by the space surrounded by the groove 252 of the anvil roller 25 and the horn roller 26. Further, a part of the rubber thread 14 may be pressed together with the first and second sheet portions 11 and 12 by the horn roller 26 and the convex portion 251 of the anvil roller 25. In these cases, when the joint j is formed (ie, before the stretched state of the thread rubber 14 is relaxed), the position of the thread rubber 14 in the expansion and contraction direction is regulated, and the thread rubber 14 is attached to the sheet portion. State.

  Further, the pressure roller and the pressure portion forming the bonding portion j are not limited to the ultrasonic welding device 22, but may be any device that can press and bond a plurality of sheet portions to each other. For example, the joint j (heat-welded portion) may be formed using a heat sealing device. The heat sealing device is a pair of heated rollers, one roller is a roller having a convex portion corresponding to the joint j on the outer peripheral surface, and the other roller is a roller having the convex portion having a smooth outer peripheral surface. Can be exemplified as a roller which is received by the roller.

  As described above, in the manufacturing method of the elastic sheet 10 of the present embodiment, the first and second sheet portions 11 and 12 and the thread rubber 14 are pressed before the joint j is formed by the ultrasonic welding device 22. The first sheet portion 11 and the second sheet portion 12 pass between the roller 23 and the anvil roller 25 and are pressed.

  Therefore, the positions of the first and second sheet portions 11 and 12 and the rubber thread 14 in the CD direction are fixed by the press roller 23. Further, in the range from the press roller 23 to the horn roller 26, the first and second sheet portions 11, 12 and the rubber thread 14 are wound around the outer peripheral surface (curved surface) of the anvil roller 25 and transported. Therefore, the first and second sheet portions 11 and 12 and the rubber thread 14 are stably conveyed while maintaining the position in the CD direction fixed by the press roller 23.

  In particular, at the nip point between the anvil roller 25 and the press roller 23, the position in the CD direction of the thread rubber 14 entering the groove 252 is fixed. Therefore, compared to the case where the press roller 23 is not provided, the thread rubber 14 upstream of the press roller 23 is more easily guided to enter the groove 252. When the thread rubber 14 and the first sheet portion 11 do not enter the groove 252 on the upstream side of the press roller 23, the thread rubber 14 and the first sheet portion 11 are pushed into the groove 252 by the press roller 23. be able to. Therefore, in a range from the press roller 23 to the horn roller 26, the state in which the thread rubber 14 has entered the groove 252 of the anvil roller 25 is maintained and is stably conveyed. Accordingly, it is possible to prevent the rubber thread 14 from being positioned on the convex part 251 and being cut by the horn roller 26 when the joint j is formed.

  Further, in the present embodiment, as shown in FIG. 4, the angle difference θ1 between the pressing angle position P3 in the rotation direction of the anvil roller 25 and the supply angle position P1 of the thread rubber 14 is determined by the pressing angle position P3 and the joining angle position P4. (Θ1 ≦ θ2).

  Therefore, in the range from the press roller 23 to the horn roller 26, the thread rubber 14 is wound around the curved surface of the anvil roller 25 and is in close contact therewith (ie, the position of the thread rubber 14 in the CD direction is fixed and stable). The length of the thread rubber 14 wound around the anvil roller 25 can be reduced in a range from when the thread rubber 14 is supplied to the anvil roller 25 to when the thread rubber 14 passes through the press roller 23, as compared with the length of the thread rubber 14.

  Therefore, on the upstream side of the press roller 23, the thread rubber 14 can move in the CD direction (wobble) without being tightly wound around the curved surface of the anvil roller 25 and closely attached thereto. Therefore, even if the thread rubber 14 is supplied on the projection 251 of the anvil roller 25, the thread rubber 14 rolls on the outer peripheral surface of the anvil roller 25 in the CD direction before being supplied to the press roller 23. , The groove 252. Thereafter, the thread rubber 14 is stably transported to the horn roller 26 while maintaining the state of having entered the groove 252. Therefore, cutting of the rubber thread 14 at the time of forming the joint j can be suppressed.

  Further, it is preferable that the first sheet portion 11 is supplied similarly to the thread rubber 14. That is, the angle difference θ3 between the pressing angle position P3 and the second supply angle position P2 in the rotation direction of the anvil roller 25 is preferably equal to or less than the angle difference θ2 between the pressing angle position P3 and the joining angle position P4 (θ3). ≤ θ2).

  By doing so, the length of the first sheet portion 11 wound around the anvil roller 25 can be shortened in a range from when the first sheet portion 11 is supplied to the anvil roller 25 to when the first sheet portion 11 passes through the press roller 23. Therefore, on the upstream side of the press roller 23, the first sheet portion 11 is easily wound into the groove 252 of the anvil roller 25 without being tightly wound around the curved surface of the anvil roller 25 and closely attached thereto. Therefore, when the thread rubber 14 is overlaid on the first sheet portion 11, the thread rubber 14 and the first sheet portion 11 easily enter the groove 252 due to the extension force of the thread rubber 14, and the joint j is formed. Cutting of the thread rubber 14 at the time can be suppressed.

Note that the angle difference θ1 (θ3) is defined as the rotation center of the anvil roller 25 and the point at which the thread rubber 14 (first sheet portion 11) starts to contact the anvil roller 25 in a cross section orthogonal to the CD direction of the manufacturing apparatus 20. And the angle θ1 (θ3) formed by the virtual line connecting the rotation center of the anvil roller 25 and the contact point between the anvil roller 25 and the press roller 23.
Similarly, the angle difference θ2 is a virtual line connecting the rotation center of the anvil roller 25, the contact point between the anvil roller 25 and the press roller 23, and the imaginary line of the anvil roller 25 in a cross section orthogonal to the CD direction of the manufacturing apparatus 20. It can also be said that it is an angle θ2 formed by an imaginary line connecting the rotation center and the contact point between the anvil roller 25 and the horn roller 26.

  More preferably, as shown in FIG. 7A, the thread rubber 14 is supplied in parallel or substantially parallel to the direction of the tangent line La to the surface of the anvil roller 25 at the pressing angle position P3 in the rotation direction of the anvil roller 25. Good. Specifically, the tangent line La refers to the pressure of the anvil roller 25 (convex portion 251) and the press roller 23 in a cross section orthogonal to the CD direction of the manufacturing apparatus 20 (in a cross section at a position in the CD direction where the rubber thread 14 is supplied). The tangent La to the surface of the anvil roller 25 (convex portion 251) at the point p1.

  The term “parallel or substantially parallel to the direction of the tangent line La” may be specifically as follows. A range from the tangent line Lb drawn from the rotation center p2 of the anvil roller 25 to the press roller 23 to the pressing angle position P3 (that is, a range from the pressing point p1 to the virtual line Lc passing through the rotation center p2 of the anvil roller 25). The thread rubber 14 may be supplied to the outer peripheral surface (Ra1, Ra2) of the anvil roller 25. In addition, the rotation center p3 of the press roller 23 is located on the extension of the virtual line Lc.

  More specifically, the yarn is formed in a range Ra1 (that is, on the groove 252) from an intersection p4 between the bottom of the groove 252 of the anvil roller 25 and the tangent Lb to an intersection p5 of the bottom of the groove 252 of the anvil roller 25 and the imaginary line Lc. Rubber 14 may be provided. However, the present invention is not limited to this, and the thread rubber 14 may be supplied to a range Ra2 from the intersection p6 of the surface of the protrusion 251 of the anvil roller 25 and the tangent Lb to the pressing point p1 (that is, on the protrusion 251).

  By supplying the thread rubber 14 to the anvil roller 25 within the above range, the thread rubber 14 can be supplied in parallel or substantially parallel to the direction of the tangent line La. By doing so, on the upstream side of the press roller 23, the thread rubber 14 is more likely to move in the CD direction without winding tightly around the curved surface of the anvil roller 25 and closely contacting it. Therefore, even if the thread rubber 14 is supplied on the protrusion 251 of the anvil roller 25, the thread rubber 14 can enter the groove 252 of the anvil roller 25 before being supplied to the press roller 23. Further, since the thread rubber 14 is easily moved in the CD direction, even if the thread rubber 14 is pressed by the press roller 23 on the projection 251, the thread rubber 14 on the projection 251 enters the groove 252 on the downstream side thereof. The press roller 23 can be guided into the groove 252 before pressing the next convex portion 251 by being guided by the thread rubber 14 that is being pressed. Therefore, cutting of the rubber thread 14 at the time of forming the joint j can be suppressed.

  7B, the thread rubber 14 may be wound around the press roller 23 and then supplied between the press roller 23 and the anvil roller 25. In this case, as shown in FIG. 7A, the thread rubber 14 may be supplied to the outer peripheral surface (Rb) of the press roller 23 in a range from the tangent line Lb to the pressing angle position P3 (virtual line Lc). That is, the thread rubber 14 may be supplied to a range Rb from the intersection p7 between the outer peripheral surface of the press roller 23 and the tangent Lb to the pressing point p1.

  By doing so, immediately upstream of the pressing point p1 between the anvil roller 25 and the press roller 23, toward the bottom surface of the groove 252 of the anvil roller 25, substantially parallel to the direction of the tangent La (for example, the arrow A in FIG. 7B). Direction), thread rubber 14 can be supplied. Therefore, the thread rubber 14 easily moves in the CD direction immediately upstream of the press roller 23, and the thread rubber 14 can enter the groove 252 of the anvil roller 25 before being supplied to the press roller 23. Further, since the thread rubber 14 is easily moved in the CD direction, even if the thread rubber 14 is pressed by the press roller 23 on the projection 251, the thread rubber 14 on the projection 251 enters the groove 252 on the downstream side thereof. The press roller 23 can be guided into the groove 252 before pressing the next convex portion 251 by being guided by the thread rubber 14 that is being pressed. Therefore, cutting of the rubber thread 14 at the time of forming the joint j can be suppressed.

  However, it is preferable to supply the thread rubber 14 to the outer peripheral surface (Ra1, Ra2) of the anvil roller 25 which is in a range from the tangent line Lb to the pressing angle position P3 (virtual line Lc).

  By doing so, the time allowance for the thread rubber 14 to move in the CD direction on the outer peripheral surface of the anvil roller 25 on the upstream side of the press roller 23 is increased. Therefore, before the thread rubber 14 is supplied to the press roller 23, the thread rubber 14 easily enters the groove 252 of the anvil roller 25. Therefore, cutting of the rubber thread 14 at the time of forming the joint j can be suppressed.

  Also, like the rubber thread 14, the first sheet portion 11 is preferably supplied to the outer peripheral surface (Ra1, Ra2) of the anvil roller 25, which extends from the tangent line Lb to the pressing angle position P3 (virtual line Lc). .

  By doing so, the first sheet portion 11 can also be supplied parallel or substantially parallel to the direction of the tangent line La. Therefore, on the upstream side of the press roller 23, the first sheet portion 11 is easily wound into the groove 252 of the anvil roller 25 without being tightly wound around the curved surface of the anvil roller 25 and closely attached thereto. Therefore, the thread rubber 14 and the first sheet portion 11 can easily enter the groove 252, and cutting of the thread rubber 14 at the time of forming the joint j can be suppressed.

  In addition, as shown in FIG. 4, it is preferable that the second sheet portion 12 is passed between the anvil roller 25 and the press roller 23 together with the first sheet portion 11 and the thread rubber 14. By doing so, the second sheet portion 12 is supplied from above the thread rubber 14 that has entered the groove portion 252 of the anvil roller 25, and the second sheet portion 12 is pressed by the press roller 23. Therefore, the thread rubber 14 is conveyed to the horn roller 26 while being kept in the groove 252. Therefore, cutting of the rubber thread 14 at the time of forming the joint j can be suppressed.

  Further, as shown in FIG. 4, the second sheet portion 12 may be wound around a press roller 23 and then supplied between the press roller 23 and the anvil roller 25. By doing so, when the rubber thread 14 is supplied to the anvil roller 25, the second sheet portion 12 is not located on the rubber thread 14. Therefore, the movement of the rubber thread 14 in the CD direction is less likely to be hindered by the second sheet portion 12. Therefore, the thread rubber 14 easily enters the groove 252.

  However, without being limited to the above, the second sheet portion 12 may be supplied between the press roller 23 and the anvil roller 25 without being wound around the press roller 23. Further, the second sheet portion 12 may be supplied between the horn roller 26 and the anvil roller 25, for example, after being wound around the horn roller 26 without passing between the press roller 23 and the anvil roller 25.

  Also, as shown in FIG. 8, when the length of the thread rubber 14 wound around the anvil roller 25 is L1 in a range from the pressing angle position P3 in the rotation direction of the anvil roller 25 to the joining angle position P4, It is preferable that the length L2 of the thread rubber 14 transported from the third transport roller 213 that transports the thread rubber 14 to the pressing angle position P3 is longer than the length L1 (L1 <L2).

  By doing so, the thread rubber 14 separates from the constraint by the third transport roller 23 and is again restrained by the press roller 23 compared to the length L1 in which the thread rubber 14 is wound around the curved surface of the anvil roller 25 and restrained. The length L2 (that is, the length L2 that is not constrained) can be increased. Therefore, the thread rubber 14 can move in the CD direction on the upstream side of the press roller 23. In other words, since the third transport roller 213 is disposed apart from the press roller 23, the thread rubber 14 is not firmly restrained between the third transport roller 213 and the press roller 23, and the upstream side of the press roller 23 In, the rubber thread 14 can move in the CD direction. Therefore, the thread rubber 14 can enter the groove 252 of the anvil roller 25, and cutting of the thread rubber 14 at the time of forming the joint j can be suppressed.

  The length L1 can be said to be 2πr1 × θ2 / 360, where r1 is the radius of the anvil roller 25 (groove 252), and θ2 is the angle difference between the pressing angle position P3 and the joining angle position P4. In addition, the length L2 can be said to be a length from a point at which the thread rubber 14 leaves the third transport roller 213 to a point at which the thread rubber 14 passes through the pressing angle position P3.

  Further, the outer peripheral surface of the press roller 23 is preferably formed of an elastic material such as rubber. By doing so, the press roller 23 can firmly adhere to the convex portion 251 of the anvil roller 25 via the first and second sheet portions 11 and 12, and firmly hold the first and second sheet portions 11 and 12 together. Can be pressed. Accordingly, the positions of the first and second sheet portions 11 and 12 and the thread rubber 14 in the CD direction are firmly fixed (the state in which the thread rubber 14 has entered the groove 252 is maintained). Further, even when the second sheet portion 12 does not pass between the press roller 23 and the anvil roller 25, the press roller 23 can be pushed into the groove portion 252 without damaging the thread rubber 14. In particular, when the press roller 23 is a smooth surface having no irregularities, the thread rubber 14 is not damaged by the convex portion of the press roller that meshes with the groove 252 of the anvil roller 23, and the strength of the thread rubber 14 can be maintained. .

<< 2nd Embodiment >>
FIG. 9 is a schematic sectional view of a stretch sheet manufacturing apparatus 20 according to the second embodiment. The second embodiment differs from the first embodiment in the ultrasonic welding device 22. The ultrasonic welding device 22 is not limited to a pair of rollers. For example, as shown in FIG. 9, instead of the horn roller 26, a non-rotating horn 27 having a flat vibrating surface 27a disposed opposite to the surface of the anvil roller 25 may be used. The vibrating surface 27a of the horn 27 vibrates in a direction to expand and contract the space between the horn 27 and the surface of the anvil roller 25, and a joint j is formed.
Further, although not shown, the outer peripheral surface of the horn roller 26 may be an uneven surface that meshes with the unevenness of the anvil roller 25.

  As described above, the embodiments of the present invention have been described. However, the above embodiments are for the purpose of facilitating the understanding of the present invention, and are not intended to limit and interpret the present invention. Further, the present invention can be changed or improved without departing from the gist thereof, and it goes without saying that the present invention includes equivalents thereof.

1 pants-type disposable diapers,
2 Absorbent body, 3 belly waist, 4 back waist, 5 thread rubber,
10 elastic sheets,
11 first sheet portion, 12 second sheet portion, 14 thread rubber,
20 stretch sheet manufacturing apparatus, 21 transport roller group (supply unit),
22 ultrasonic welding equipment (joining part forming part),
23 press roller (pressing part), 24 discharge roller,
25 anvil roller (pressure roller, pressing part),
26 Horn roller (crimping part),
27 Horn (crimp),
j junction, jP junction pair

Claims (9)

A method for producing a stretchable sheet in which a first sheet portion and a second sheet portion are laminated with thread rubber interposed therebetween,
At the supply angle position in the rotation direction of the pressure roller where the outer peripheral surface is the uneven surface, the thread rubber is attached to the pressure roller so that the rubber thread is located outside the first sheet portion in the radial direction of the pressure roller. Supplying a
A step of pressing the first sheet portion at a pressing angle position in the rotation direction by passing the first sheet portion and the thread rubber between the pressure roller and a press roller that contacts the pressure roller. When,
By passing the first sheet portion and the second sheet portion with the thread rubber interposed between the pressure roller and the pressure portion contacting the pressure roller, at the joining angle position in the rotation direction, Forming a plurality of joints that press and join the first sheet portion and the second sheet portion together with each other, wherein the plurality of joints regulate the position of the rubber thread in the expansion and contraction direction. Have
A method for manufacturing a stretchable sheet, wherein an angle difference between the pressing angle position and the supply angle position is equal to or less than an angle difference between the pressing angle position and the joining angle position. It is a manufacturing method of the elastic sheet of Claim 1, Comprising:
At a second supply angle position in the rotation direction, supplying the first sheet portion to the pressure roller,
A method for manufacturing a stretchable sheet, wherein an angle difference between the pressing angle position and the second supply angle position is equal to or less than an angle difference between the pressing angle position and the joining angle position. It is a manufacturing method of the elastic sheet according to claim 1 or 2,
An outer peripheral surface of the pressure roller, or an outer peripheral surface of the press roller, which is a range from a tangent drawn from the rotation center of the pressure roller to the press roller to the pressing angle position in the rotation direction, the thread rubber. And a method for producing a stretchable sheet. It is a manufacturing method of the elastic sheet of Claim 3, Comprising:
A method for manufacturing a stretchable sheet, comprising supplying the thread rubber to an outer peripheral surface of the pressure roller in the above range. It is a manufacturing method of the elastic sheet of Claim 4, Comprising:
A method for manufacturing a stretchable sheet, wherein the first sheet portion is also supplied to the outer peripheral surface of the pressure roller in the range. It is a manufacturing method of the elastic sheet according to any one of claims 1 to 5,
A method for manufacturing a stretchable sheet, characterized in that the second sheet part is passed between the pressure roller and the press roller together with the first sheet part and the thread rubber. It is a manufacturing method of the elastic sheet according to any one of claims 1 to 6,
Using a transport roller, supply the thread rubber to the pressure roller,
In the range from the pressing angle position to the joining angle position in the rotation direction, when the length of the thread rubber wound around the pressure roller is length L1,
A length of the thread rubber conveyed from the conveyance roller to the pressing angle position is longer than the length L1. It is a manufacturing method of the elastic sheet according to any one of claims 1 to 7,
An outer peripheral surface of the press roller is formed of an elastic material. An apparatus for manufacturing a stretchable sheet in which a first sheet portion and a second sheet portion are laminated with thread rubber interposed therebetween,
At the supply angle position in the rotation direction of the pressure roller where the outer peripheral surface is the uneven surface, the thread rubber is attached to the pressure roller so that the rubber thread is located outside the first sheet portion in the radial direction of the pressure roller. A supply unit for supplying
By passing the first sheet portion and the thread rubber between the pressure roller and the press roller that contacts the pressure roller, a pressing force that presses the first sheet portion at a pressing angle position in the rotation direction. Department and
By passing the first sheet portion and the second sheet portion with the thread rubber interposed between the pressure roller and the pressure portion contacting the pressure roller, at the joining angle position in the rotation direction, A plurality of joints for pressing and joining the first sheet portion and the second sheet portion to each other, the joint forming portion forming the plurality of joints for regulating the position of the thread rubber in the direction of expansion and contraction; And having
The elastic sheet manufacturing apparatus according to claim 1, wherein an angle difference between the pressing angle position and the supply angle position is equal to or less than an angle difference between the pressing angle position and the joining angle position.

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