JP7262958B2 - Elastic sheet manufacturing method and elastic sheet manufacturing apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to a stretch sheet manufacturing method and a stretch sheet manufacturing apparatus.

As a method of manufacturing a stretchable sheet, a method of attaching stretched rubber threads between sheets with an adhesive is known. On the other hand, in Patent Document 1, a rubber thread (wire-like element) arranged between sheets is passed between a pair of rollers to press the sheet so that the rubber thread crosses the rubber thread. A method is disclosed for forming connections on both sides of the . In the narrowed portion formed between the connection portions on both sides of the rubber thread, the rubber thread in a state of being thickened due to no tension can be fixed, and the rubber thread can be attached to the sheet. In this way, by attaching the rubber thread to the sheet without using an adhesive, it is possible to suppress deterioration in shrinkage performance of the rubber thread and deterioration in flexibility of the elastic sheet due to hardening of the adhesive.

Japanese Patent No. 3212615

In the elastic sheet manufactured as described above, the thread rubber may be cut. In that case, if the distance between the joints (pair of joints) formed on both sides of the rubber thread is wide and is greater than the diameter of the rubber thread in the stretched state, or if the stretch ratio of the rubber thread is high, the rubber thread will be cut. In this case, the rubber thread easily slips through the pair of joints, and there is a possibility that the cut ends of the rubber thread cannot be fixed by the desired pair of joints. As a result, stretchability cannot be exhibited in a desired region of the stretchable sheet.

The present invention has been made in view of the above-described problems, and provides a stretchable sheet in which a rubber thread is attached to a sheet portion at joint pairs located on both sides of the rubber thread. The purpose is to fix the cut end of the

The main invention for achieving the above object is
A method for manufacturing a stretchable sheet having a longitudinal direction and a lateral direction, comprising:
disposing the rubber thread stretched in the lateral direction between the first sheet portion and the second sheet portion;
forming a plurality of joints by pressing the first sheet and the second sheet to form a plurality of joints;
a step of relaxing the stretched state of the rubber thread;
a step of cutting the rubber thread at a cutting position in the horizontal direction after the relaxing step;
The plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction,
After the step of cutting, the contracted rubber thread is sandwiched between the pair of joint portions to restrict the lateral position of the rubber thread,
In the lateral direction, when the joint portion pair adjacent to one side of the cutting position is defined as a one side joint portion pair, and the joint portion pair adjacent to the other side of the cutting position is defined as the other side joint portion pair,
In the relaxing step, the stretched state of the rubber thread between the pair of joints on one side and the pair of joints on the other side in the horizontal direction is relaxed,
When the elongation ratio of the rubber thread in the stretched state is R1, the elongation ratio of the rubber thread relaxed in the relaxing step is R2, and the elongation ratio of the rubber thread in the natural state is R3, the elongation ratio is: R2 has the following formula
R2>R3+(R1-R3)/2
A method for producing a stretchable sheet characterized by satisfying

According to such a method for manufacturing a stretchable sheet, in the stretchable sheet in which the rubber thread is attached to the sheet portion at joint pairs located on both sides of the rubber thread, the cut ends of the rubber thread are fixed at desired joint pairs. easier to be

1 is a plan view of a stretchable sheet 10 manufactured by the manufacturing method of this embodiment. FIG. FIG. 2 is a schematic cross-sectional view of the elastic sheet 10 of FIG. 1; 1 is an explanatory diagram of a basic configuration of a stretch sheet manufacturing apparatus 20. FIG. 4A is an explanatory view of the surfaces of the anvil roller 23 and the horn roller 24, and FIG. 4B is a schematic enlarged view of the nearest portion between the anvil roller 23 and the horn roller 24. FIG. 5A and 5B are explanatory diagrams of a method of attaching the rubber thread 14 at the joint j. 6A to 6C are explanatory diagrams of the cutting process of the rubber thread 14. FIG. FIG. 5 is an explanatory diagram of a relaxation process and a cutting process of the rubber thread 14; FIG. 10 is an explanatory diagram of a relaxation process and a cutting process of the rubber thread 14 in Modification 1; 9A and 9B are explanatory diagrams of the relaxation process and the cutting process of the rubber thread 14 in Modification 2. FIG. 10A and 10B are explanatory diagrams of the relaxation step and the cutting step of the rubber thread 14 in Modification 3. FIG. It is explanatory drawing of the relaxation process and cutting process of the rubber thread 14 in 2nd Embodiment. It is explanatory drawing of the relaxation process and cutting process of the rubber thread 14 in 3rd Embodiment. It is explanatory drawing of the relaxation process and cutting process of the rubber thread 14 in 4th Embodiment. It is explanatory drawing of the relaxation process and cutting process of the rubber thread 14 in 4th Embodiment.

At least the following matters will become apparent from the descriptions of this specification and the accompanying drawings.
A method for manufacturing a stretchable sheet having a longitudinal direction and a lateral direction, comprising a step of disposing a rubber thread stretched in the lateral direction between a first sheet portion and a second sheet portion; and the second sheet portion are crimped to form a plurality of joints joined to each other, the step of relaxing the stretched state of the rubber thread, and the step of relaxing, at the cutting position in the horizontal direction a step of cutting the rubber thread, wherein the plurality of joints have pairs of joints positioned on both sides of the rubber thread in the longitudinal direction, and after the step of cutting, the contracted In the step of regulating the lateral position of the rubber thread by sandwiching the rubber thread between the pair of joint portions, and in the relaxing step, in the lateral direction, at least a portion on one side of the cutting position and the Relaxing the stretched state of the rubber thread in at least a part on the other side of the cutting position.

According to such a stretchable sheet manufacturing method, the rubber thread can be cut with the diameter of the rubber thread on one side and the other side larger than the cutting position, and the rubber thread is less likely to slip through the joints. . Therefore, the cut ends of the rubber thread can be easily fixed at a desired joint portion pair.

In the method for manufacturing such a stretchable sheet, in the step of relaxing, the rubber thread is relaxed so as to be in a state between the stretched state and the natural state.

According to such a method for manufacturing a stretchable sheet, it is possible to cut the rubber thread that is moderately stretched, and to reliably and cleanly cut the rubber thread.

In the method for manufacturing such a stretchable sheet, the elongation ratio of the rubber thread in the stretched state is R1, the elongation ratio of the rubber thread relaxed in the relaxing step is R2, and the rubber thread in the natural state is When the elongation ratio is R3, the elongation ratio R2 is the following formula R2>R3+(R1-R3)/2
to meet

According to such a method for manufacturing a stretchable sheet, it is possible to cut the rubber thread that is moderately stretched, and to reliably and cleanly cut the rubber thread.

In this stretchable sheet manufacturing method, the upstream drive roller supplies the laminate in which the rubber thread is arranged between the first sheet portion and the second sheet portion to the rubber thread cutting device. and the downstream driving roller discharges the laminate from the cutting device, and the peripheral speed of the upstream driving roller is faster than the peripheral speed of the downstream driving roller.

According to such a stretchable sheet manufacturing method, the stretched state of the rubber thread can be relaxed between the upstream drive roller and the downstream drive roller, and the cut ends of the rubber thread can be cut at desired joint pairs. Easier to fix.

In this stretchable sheet manufacturing method, a second upstream driving roller between the upstream driving roller and the cutting device supplies the laminate to the cutting device, and the downstream driving roller and the A second downstream drive roller between cutting devices ejects the stack from the cutting device and has a peripheral speed of the second upstream drive roller that is slower than the peripheral speed of the upstream drive roller. and setting the peripheral speed of the second downstream drive roller faster than the peripheral speed of the second upstream drive roller and faster than the peripheral speed of the downstream drive roller.

According to such a method for manufacturing a stretchable sheet, the cut ends of the rubber thread can be easily fixed at a desired joint pair. Furthermore, the rubber thread can be stretched between the second upstream drive roller and the second downstream drive roller (that is, around the cutting position), and the rubber thread can be reliably and cleanly cut.

In the method for manufacturing such a stretchable sheet, the cutting device has a cutter roller having a cutter blade and a receiving roller arranged opposite to the cutter roller, and the circumferential speed of the cutter roller is set at the upstream drive Faster than the peripheral speed of the roller.

According to such a method for manufacturing a stretchable sheet, the cut ends of the rubber thread can be easily fixed at a desired joint pair. Furthermore, since the cutter blade can cut the rubber thread while extending it in the horizontal direction, the rubber thread can be reliably and cleanly cut.

In the method for manufacturing such a stretchable sheet, the cutter blade of the cutting device presses down the laminate in its thickness direction to cut it.

According to such a method for manufacturing a stretchable sheet, the cut ends of the rubber thread can be easily fixed at a desired joint pair. Furthermore, since the cutter blade can cut the rubber thread while extending it in the thickness direction of the laminate, the rubber thread can be reliably and cleanly cut.

In the method for manufacturing such a stretchable sheet, the rubber thread is cut while transporting a laminate in which the rubber thread is arranged between the first sheet portion and the second sheet portion by a transport device, The conveying device has a plurality of holding units that partially hold the laminate at intervals in the conveying direction of the laminate, and after narrowing the interval between the holding units, Cutting the located rubber thread.

According to such a method for manufacturing a stretchable sheet, the stretched state of the rubber thread positioned between the holding portions can be relaxed, and the stretched rubber thread can be cut. The cut ends of the rubber thread are easily fixed by the pair.

In the method for manufacturing such a stretchable sheet, the rubber thread is cut while transporting a laminate in which the rubber thread is arranged between the first sheet portion and the second sheet portion by a transport device, The supply roller supplies the laminate to the transport device, the supply speed of the laminate by the supply roller is higher than the transport speed of the laminate by the transport device, and the transport device transports the laminate. A plurality of holding portions that partially hold the laminated body are provided at intervals in the conveying direction of the laminate, and after widening the interval between the holding portions, the rubber thread positioned between the holding portions is cut. .

According to such a method for manufacturing a stretchable sheet, since the rubber thread positioned between the holding portions can be stretched and cut, the rubber thread can be reliably and neatly cut. Further, the stretched state of the rubber thread positioned on the holding portions on the upstream side and the downstream side in the conveying direction from the cutting position of the rubber thread can be relaxed, and the cut ends of the rubber thread are fixed at desired joint pairs. easier to be

In the method for manufacturing such a stretchable sheet, the rubber thread is cut while transporting a laminate in which the rubber thread is arranged between the first sheet portion and the second sheet portion by a transport device, The conveying device has a suction unit that partially sucks the laminate and a support unit that partially supports the laminate, which are arranged alternately in a conveying direction of the laminate. After narrowing the interval in the conveying direction, the rubber thread positioned on the suction part is cut.

According to such a stretchable sheet manufacturing method, the rubber thread extending on the suction portion can be cut, and the rubber thread can be reliably and cleanly cut. In addition, the stretched state of the rubber thread positioned between the suction portions, that is, the rubber thread positioned upstream and downstream in the conveying direction from the cutting position of the rubber thread can be relaxed, and the thread can be cut at a desired joint pair. The cut ends of the rubber are easily fixed.

In the method for manufacturing such a stretchable sheet, the distance between the pair of joints in the longitudinal direction is equal to or greater than the diameter of the rubber thread in the stretched state.

According to such a method for manufacturing a stretchable sheet, even when the rubber thread easily slips through the pair of joints, the cut ends of the rubber thread are easily fixed at the desired pair of joints.

A stretchable sheet manufacturing apparatus having a vertical direction and a horizontal direction, comprising: an arrangement unit for arranging a rubber thread stretched in the horizontal direction between a first sheet portion and a second sheet portion; and the first sheet. a joining portion forming portion that forms a plurality of joining portions that are joined to each other by crimping the portion and the second sheet portion; a relaxing portion that relaxes the stretched state of the rubber thread; a cutting portion that cuts the rubber thread at a cutting position in the direction, wherein the plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction, and the rubber thread is cut. After the contraction, the shrunk rubber thread is sandwiched between the pair of joint portions, the position of the rubber thread in the lateral direction is regulated, and the relief portion is located on one side of the cutting position in the lateral direction. and at least a portion on the other side of the cutting position, the stretched state of the rubber thread is relaxed.

According to such a stretchable sheet manufacturing apparatus, the rubber thread can be cut with the diameter of the rubber thread on one side and the other side larger than the cutting position, and the rubber thread is less likely to slip through the joints. . Therefore, the cut ends of the rubber thread can be easily fixed at a desired joint portion pair.

===Embodiment===
<<Configuration of elastic sheet 10>>
FIG. 1 is a plan view of a stretchable sheet 10 manufactured by the manufacturing method (manufacturing apparatus) of this embodiment. FIG. 1 is a diagram showing a state in which the elastic sheet 10 is stretched without wrinkles. FIG. 2 is a schematic cross-sectional view of the elastic sheet 10 of FIG.

The stretchable sheet 10 has a horizontal direction (stretching direction), a thickness direction, and a vertical direction (width direction) which are orthogonal to each other. In addition, the stretchable sheet 10 has a first sheet portion 11 and a second sheet portion 12 laminated in a thickness direction, and a plurality of stretchable 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 horizontal direction of the stretchable sheet 10 while being spaced apart in the vertical direction. The rubber thread 14 is attached to the first sheet portion 11 and the second sheet portion 12 in a stretched state. Therefore, the elastic sheet 10 is provided with elasticity in the direction along which the rubber thread 14 extends. As the thread rubber 14 (thread-like elastic member), in addition to thread-like natural rubber, various known synthetic rubbers such as styrene-based rubber, urethane-based rubber, ester-based rubber, polyurethane, and polyethylene can be applied.

The plurality of joint portions j are for crimping and joining the first sheet portion 11 and the second sheet portion 12 to each other, and are arranged intermittently in the horizontal and vertical directions of the elastic sheet 10. . Also, the plurality of joints j regulate the lateral position of the rubber thread 14 with respect to the first sheet portion 11 and the second sheet portion 12 . Although the details will be described later, the lateral position of the rubber thread 14 is regulated by joint portion pairs jP formed on both sides of the rubber thread 14 in the longitudinal direction. Although the planar shape of the joint j illustrated in FIG. 1 is a rectangular shape, the planar shape of the joint j is not particularly limited, and any shape such as an elliptical shape, a circular shape, a parallelogram shape, or the like can be adopted.

The stretchable sheet 10 shown in FIG. 2 is composed of two sheets. It can be a part. Alternatively, the elastic sheet 10 may be formed by stacking one or more separate sheet portions on the first and second sheet portions 11 and 12 . That is, the elastic sheet 10 may have three or more layers.

<<Usage example of elastic sheet 10>>
The stretchable sheet 10 manufactured by the manufacturing method (manufacturing apparatus) of the present embodiment is used, for example, as a component of absorbent articles such as disposable diapers. In that case, a soft sheet member can be exemplified as the first sheet portion 11 and the second sheet portion 12 that constitute the elastic sheet 10 . Examples include nonwoven fabrics such as spunbond nonwoven fabrics and SMS (spunbond/meltblown/spunbond) nonwoven fabrics. At least one of the first sheet portion 11 and the second sheet portion 12 may be a stretchable sheet (stretchable film or stretchable nonwoven fabric) that is stretchable in the stretching direction of the stretchable sheet 10 . Also, a stretchable film or stretchable nonwoven fabric may be sandwiched between the first sheet portion 11 and the second sheet portion 12 .

Specifically, the stretchable sheet 10 can be used for the ventral waist portion and the back waist portion of a pants-type disposable diaper. In addition, the elastic sheet 10 can be used for the leg gathers provided on both sides of the absorbent body in the lateral direction of the disposable diaper. In addition, in a tape-type disposable diaper (not shown), the elastic sheet 10 can be used for the side panel for attaching the fastening tape (hook member) to the back waist portion.

In addition, the stretchable 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 shorts-type sanitary napkins. be. Moreover, it can be used not only for absorbent articles but also for masks, cleaning sheets, and the like.

=== Elastic sheet manufacturing apparatus and manufacturing method ===
<<First Embodiment>>
(Basic configuration of elastic sheet manufacturing apparatus 20)
FIG. 3 is an explanatory diagram of the basic configuration of the elastic sheet manufacturing apparatus 20 in the first embodiment. FIG. 4A is an explanatory diagram of the surfaces of the anvil roller 23 and the horn roller 24. FIG. FIG. 4B is a schematic enlarged view of the nearest portion between the anvil roller 23 and the horn roller 24. FIG. 5A and 5B are explanatory diagrams of a method of attaching the rubber thread 14 at the joint j.

The elastic sheet manufacturing apparatus 20 includes a conveying roller group 21 ( FIG. 4 ), an ultrasonic welding device 22 , a discharge roller 25 , a cutter roller 26 and a receiving roller 27 . The stretchable sheet 10 is manufactured as a continuous sheet continuous in its lateral direction. In the stretchable sheet manufacturing apparatus 20, the direction in which the materials are continuous is the conveying direction, and the direction perpendicular to the conveying direction (that is, the longitudinal direction of the stretchable sheet 10) is the CD direction.

As shown in FIG. 4 , the conveying roller group 21 is arranged upstream of the ultrasonic welding device 22 in the conveying direction, and conveys the materials constituting the stretchable sheet 10 and supplies them to the ultrasonic welding device 22 . Specifically, the transport roller group 21 includes a first transport roller 211 that transports the continuum of the first sheet portion 11, a second transport roller 212 that transports the continuum of the second sheet portion 12, and the rubber thread 14. and a third conveying roller 213 for conveying a plurality of continuities.

The first to third conveying rollers 211 to 213 are rotated around a rotation axis along the CD direction by a drive source (eg, motor) not shown. The first to third conveying rollers 211 to 213 may be a pair of rollers or a single roller. Alternatively, materials 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 continuum of the second sheet portion 12, the continuum of the rubber thread 14, and the continuum of the elastic sheet 10 are simply referred to as the first sheet portion 11, the second sheet portion 12, The rubber thread 14 is also referred to as the elastic sheet 10 .

The ultrasonic welding device 22 (joint part forming part) is for forming the joint part j of the elastic sheet 10, and has an anvil roller 23 and a horn roller 24 which are arranged to face each other. The anvil roller 23 and the horn roller 24 are rotated around a rotation axis along the CD direction by a drive source (not shown).

The outer peripheral surface of the anvil roller 23 is an uneven surface on which a plurality of protrusions 231 are formed, as shown in FIG. 4A. This convex portion 231, together with the horn roller 24, ultrasonically welds the material to form the joint portion j. Therefore, the protrusions 231 are arranged corresponding to the arrangement pattern of the joints j in the elastic sheet 10 .

The outer peripheral surface of the horn roller 24 is a smooth surface without irregularities, and vibrates in the direction of increasing or decreasing the distance between it and the surface of the anvil roller 23 (that is, the thickness direction of the material passing therebetween). The frequency of vibration is a predetermined value, for example, between 20 kHz and 40 kHz, and the amplitude is a predetermined value, for example, between 20 microns and 60 microns. Therefore, the surface of the horn roller 24 is ultrasonically vibrated. Such vibration is generated by, for example, inputting an electric signal of the above frequency to a piezo element of a converter (not shown) connected to the horn roller 24 .

Moreover, in the manufacturing apparatus 20 illustrated in FIG. 3 , the first and second sheet portions 11 and 12 and the rubber thread 14 pass between the anvil roller 23 and the horn roller 24 after being wound around the anvil roller 23 . The peripheral speed values of the first and second transport rollers 211 and 212 that transport the first and second sheet portions 11 and 12 are approximately the same as the peripheral speed value of the anvil roller 23, respectively. Therefore, the first and second sheet portions 11 and 12 are wound around the anvil roller 23 in a state in which they are substantially stretched and not slackened.

On the other hand, the peripheral speed value of the third transport roller 213 that transports the rubber thread 14 is 1/approximately the expansion ratio of the peripheral speed value of the anvil roller 23 . The extension ratio is a ratio R (R=E1/E0) that indicates how many times the total length E1 of the rubber thread 14 in the elastic sheet 10 in the stretched state is stretched over the total length E0 in the unloaded state, which is the natural length. . Therefore, while passing between the 3rd conveyance roller 213 and the anvil rollers 23, the thread rubber 14 is extended|stretched by said extension ratio, and it winds around the anvil roller 23 in the said extended state.

The discharge roller 25 is a roller that discharges the semi-finished elastic sheet having the joint j formed thereon to the step of cutting the rubber thread 14 . The discharge roller 25 is rotated around a rotation axis along the CD direction by a drive source (not shown).

The cutter roller 26 and the receiving roller 27 (cutting portion) are rollers arranged to face each other downstream of the ultrasonic welding device 22 in the conveying direction. The cutter roller 26 and the receiving roller 27 are rotated around a rotation axis along the CD direction by a drive source (not shown).

A cutter blade 261 protruding radially outward of the cutter roller 26 is provided on the outer peripheral surface of the cutter roller 26 . In FIG. 3, two cutter blades 261 are provided at intervals in the rotation direction of the cutter roller 26, but the number of cutter blades is not limited to this. The interval between the cutter blades 261 in the rotational direction corresponds to the interval between the cutting positions of the rubber thread 14 . Further, a plurality of rubber threads 14 arranged in the CD direction (longitudinal direction) in the stretchable sheet 10 may be cut by a cutter blade 261 extending in the CD direction, or a plurality of rubber threads 14 arranged in the CD direction provided for each rubber thread 14 may be cut. A plurality of cutter blades 261 may be used for cutting.

A receiving blade 271 that receives the cutter blade 261 of the cutter roller 26 is provided on the outer peripheral surface of the receiving roller 27 . However, the receiving roller 27 may not have the receiving blade 271. For example, it may be a roller having a smooth outer peripheral surface, or a roller provided with a groove for receiving the cutter blade 261. .

(Manufacturing method: step of forming joint j)
In the method of manufacturing the elastic sheet 10 by the manufacturing apparatus 20 configured as described above, first, the conveying roller group 21 (placement section) supplies the first and second sheet portions 11 and 12 and the rubber thread 14 to the anvil roller 23 . Specifically, in the radial direction of the anvil roller 23, the rubber thread 14 is positioned outside the first sheet portion 11 and is supplied so that the rubber thread 14 is positioned inside the second sheet portion 12. be. In this way, the rubber thread 14 is arranged between the first sheet portion 11 and the second sheet portion 12 in a stretched state in the conveying direction (horizontal direction).

Next, the first and second sheet portions 11 and 12 and the rubber thread 14 wound around the anvil roller 23 are conveyed to the ultrasonic welding device 22 by the rotation of the anvil roller 23, and between the anvil roller 23 and the horn roller 24. pass through At this time, the ultrasonic welding device 22 ultrasonically welds (compresses) the first sheet portion 11 and the second sheet portion 12 to form a plurality of joints j to be joined to each other.

Specifically, the first and second sheet portions 11 and 12 are melted and joined by receiving ultrasonic vibrations from the horn roller 24 at positions corresponding to the convex portions 231 of the anvil roller 23 . At this time, the rubber thread 14 is positioned in the groove 232 (see FIGS. 4A and 4B) of the anvil roller 23 and is not ultrasonically welded. In addition, in FIG. 3 and the like, the rubber thread 14 is positioned on the convex portion 231 of the anvil roller 23 for easy understanding of the drawings. However, the thread rubber 14 is actually located in the groove portion 232 .

Further, as described above, the plurality of joints j serve to regulate the lateral position of the rubber thread 14 with respect to the first sheet portion 11 and the second sheet portion 12, that is, the first and second sheet portions It also serves to attach the rubber thread 14 to the portions 11 and 12 . For this reason, in the present embodiment, as shown in FIG. 1, a plurality of joint pairs jP located on both sides of the rubber thread 14 in the longitudinal direction of the stretchable sheet 10 are spaced apart in the lateral direction of the stretchable sheet 10. Form. Note that the junction pair jP may be continuous in the horizontal direction.

Further, as shown in FIG. 5A, in the CD direction (vertical direction), the distance Dj between the joint portion pair jP located on both sides of the rubber thread 14 is the CD direction of the rubber thread 14 that is stretched when the joint portion j is formed. diameter D14 or more. Further, the interval Dj is assumed to be smaller than the diameter in the CD direction of the rubber thread 14 in the unloaded state, which is the natural length. The rubber thread 14 in the stretched state is thinner than the thickness of the rubber thread 14 in the natural state by the stretched amount. Therefore, after the continuous body of the rubber thread 14 is cut after the formation of the joint j, the stretched state of the rubber thread 14 is relaxed, and as shown in FIG. The thread rubber 14 to be connected is sandwiched between the pair of joints jP. As a result, the lateral position of the rubber thread 14 is regulated, and the rubber thread 14 is attached to the seat portion.

However, not limited to the above, the distance Dj between the joint portion jP may be smaller than the diameter D14 in the CD direction of the rubber thread 14 that is elongated when the joint portion j is formed. That is, the joining portion j may be formed while the rubber thread 14 is compressed by the space surrounded by the groove portion 232 of the anvil roller 23 and the horn roller 24 . Also, a part of the rubber thread 14 may be crimped together with the first and second sheet portions 11 and 12 by the convex portion 231 of the anvil roller 23 and the horn roller 24 . In this case also, the rubber thread 14 is sandwiched between the joints jP in the stretchable sheet 10, the lateral position of the rubber thread 14 is regulated, and the rubber thread 14 is attached to the sheet portion.

Further, the joining portion forming portion that forms the joining portion j is not limited to the ultrasonic welding device 22, and may be any device capable of crimping and joining a plurality of sheet portions to each other. For example, a heat sealer may be used to form the joint j (thermally welded portion). The heat-sealing device is a pair of heated rollers, one roller having a convex portion corresponding to the joint j on the outer peripheral surface, and the other roller having the convex portion on the smooth outer peripheral surface. can be exemplified.

Moreover, although FIG. 3 illustrates the ultrasonic welding device 22 configured by a pair of rollers, the present invention is not limited to this. Instead of horn roller 24, a non-rotating horn having a flat vibrating surface positioned opposite the surface of anvil roller 23 may be used. Alternatively, the horn side that vibrates ultrasonically may be a roller-shaped device, and the anvil side may be a non-rotating device having a flat surface that receives ultrasonic vibrations. Alternatively, the vibration surface on the horn side may be an uneven surface, and the surface on the anvil side may be a smooth surface. Also, both the horn-side and anvil-side surfaces may be uneven surfaces.

(Manufacturing method: step of cutting the rubber thread 14)
6A to 6C are views showing the rubber thread 14 and the joint pairs jP in the elastic sheet 10, and are explanatory views of the cutting process of the rubber thread 14. FIG. FIG. 7 is an explanatory diagram of the relaxation process and cutting process of the rubber thread 14 .

The method for manufacturing the elastic sheet 10 of the present embodiment has a step of cutting the rubber thread 14 after forming the joint j. Therefore, as shown in FIG. 3, the laminate 10' of the first and second sheet portions 11 and 12 and the rubber thread 14 on which the joint portion j is formed is conveyed by the discharge roller 25, and is transferred to the cutter roller 26 and the receiving roller 26. It passes between rollers 27 . At this time, the cutter blade 261 is inserted into the laminate 10 ′ supported by the receiving blade 271 to cut the rubber thread 14 .

In the step of cutting the rubber thread 14, the first sheet portion 11 and the second sheet portion 12 may be cut and separated together with the rubber thread 14, or only the rubber thread 14 may be cut and separated, and the second sheet portion 12 may be cut and separated. The first sheet portion 11 and the second sheet portion 12 may not be separated.

For example, in the case of cutting the stretchable sheet 10 into the component size of the absorbent article, the first sheet portion 11 and the second sheet portion 12 are preferably cut and separated together with the rubber thread 14 . On the other hand, the stretchability may be partially removed from the stretchable sheet 10 . For example, when the stretchable sheet 10 is used for the ventral waist portion and the back waist portion of a pants-type disposable diaper, in order to ensure the flatness of the absorbent body, etc., Elasticity may be removed from areas overlapping the absorbent body. In this case, it is preferable to cut and separate the central portion of the rubber thread 14 extending in the lateral direction in the elastic sheet 10 so as not to separate the first sheet portion 11 and the second sheet portion 12 . However, if the first sheet portion 11 and the second sheet portion 12 are also separated together with the rubber thread 14, no cut marks remain on the elastic sheet 10, so that the appearance of the elastic sheet 10 can be improved.

In the stretchable sheet 10, the stretchability is exhibited from the position where the cut end portion 14a of the cut rubber thread 14 is fixed by the joint portion jP. For example, as shown in FIG. 6A, the pair of joints on both sides of the cutting position Pc of the rubber thread 14 in the lateral direction is defined as the first pair of joints jP1, and the pair of joints on the opposite side of the cutting position from the pair of first joints jP1. Let the junction pair be a second junction pair jP2. When the cut end portion 14a of the rubber thread 14 is fixed by the first joint pair jP1, stretchability is exhibited on the side opposite to the cutting position with respect to the first joint pair jP1.

Therefore, the joint portion pair jP to which the cut ends 14a of the rubber thread 14 are to be fixed is determined according to the region in the stretchable sheet 10 to exhibit stretchability. However, as shown in FIG. 5A, when the distance Dj between the joint portion jP in the longitudinal direction is relatively wide and is equal to or larger than the diameter D14 of the rubber thread 14 that is stretched when the joint portion j is formed, the yarn after cutting The rubber 14 easily slips through between the joint pair jP. Further, even when the distance Dj between the joint portion jP is narrower than the diameter D14 of the rubber thread 14 that is stretched when the joint portion j is formed, if the elongation ratio of the rubber thread 14 is high, the length of the rubber thread 14 will increase. The shrinkage force after cutting is strong, and the rubber thread 14 easily slips through the joints jP.

Therefore, even if it is desired to fix the cut end portion 14a of the rubber thread at the first joint pair jP1, simply cutting the rubber thread 14 does not allow the rubber thread 14 to move between the first joint pair jP1. There is a possibility that the rubber thread 14 may pass through and be fixed at the second joint pair jP2 or may be fixed at the joint pair jP on the side opposite to the cutting position from the second joint pair jP2.

Therefore, in the manufacturing method of the present embodiment, the step of relaxing the stretched state of the rubber thread 14 when the rubber thread 14 is placed on the sheet portions 11 and 12, and the step of cutting the rubber thread 14 after the step of relaxing. have. In the relaxing step, the stretched state of the rubber thread 14 is relaxed in at least a portion of the rubber thread 14 on one side of the cutting position Pc and at least a portion of the rubber thread 14 on the other side of the cutting position Pc in the horizontal direction.

At least a portion of the rubber thread 14 on one side and the other side of the cut position Pc means the rubber thread 14 around the joint pair jP (here, the first joint pair jP1) to which the cut end 14a of the rubber thread is to be fixed. is part of By doing so, as shown in FIGS. 6B and 6C, before the rubber thread 14 is cut, the stretched state of the rubber thread 14 around the first joint pair jP1 is relaxed, and the diameter of the rubber thread 14 is increased. Become. Therefore, after the rubber thread 14 is cut, it becomes difficult for the rubber thread 14 to slip through the first joint portion pair jP1.

As described above, according to the manufacturing method of the present embodiment, when the distance Dj between the joint portion and jP in the vertical direction is equal to or greater than the diameter D14 of the rubber thread 14 in the stretched state, or when the stretch ratio of the rubber thread 14 is high, Even if the rubber thread 14 easily slips through the joint pair jP, the cut end 14a of the rubber thread is likely to be fixed at the desired joint pair jP. Therefore, it is possible to prevent the stretchable region of the stretchable sheet 10 from being narrowed, and stretchability can be expressed in a desired region of the stretchable sheet 10 .

A portion of the rubber thread 14 that does not include the desired joint pair jP to which the cut end 14a of the rubber thread is to be fixed may be relaxed. Preferably, however, the portion of the rubber thread 14 that includes the rubber thread 14 located between the desired joint pair jP is relaxed. By doing so, the diameter of the rubber thread 14 positioned between the desired joint pair jP is increased, and the rubber thread 14 can be cut in a state in which the rubber thread 14 is sandwiched between the desired joint pair jP. 14 is more difficult to slip through the desired junction pair jP.

Further, as shown in FIG. 6B, the rubber thread 14 may be cut in a state in which the stretched state of the rubber thread 14 located at the cutting position Pc is relaxed, or as shown in FIG. The rubber thread 14 may be cut while the stretched state of the rubber thread 14 is not relaxed.

Further, in FIG. 6A, the first joint pair jP1 positioned immediately adjacent to the cutting position Pc of the rubber thread 14 is the joint pair jP for fixing the cut end 14a of the rubber thread, but the present invention is not limited to this. . That is, the N-th (N≧2) joint pair jP from the cutting position Pc of the rubber thread 14 may be the joint pair jP for fixing the cut end 14a of the rubber thread.

Further, it is preferable that the diameter of the rubber thread 14 whose stretched state is relaxed is equal to or larger than the distance (Dj in FIG. 5A) between the joint portion pair jP in the vertical direction. This makes it even more difficult for the rubber thread 14 to slip through the desired joint pair jP.

However, if the stretched state of the rubber thread 14 is relaxed too much, it becomes difficult to cut the rubber thread 14 (especially when the rubber thread 14 at the cutting position Pc is relaxed as shown in FIG. 6B). Therefore, the state (extension ratio) between the stretched state (extension ratio at) when the rubber thread 14 is arranged on the sheet portions 11 and 12 and the unloaded natural state (stretch ratio at) It is preferable to relax the rubber thread 14 so that By doing so, the rubber thread 14 that is moderately elongated can be cut, and the rubber thread 14 can be reliably and cleanly cut.

Furthermore, the stretch ratio of the rubber thread 14 in the stretched state arranged on the sheet portions 11 and 12 is R1, the stretch ratio of the rubber thread 14 relaxed in the relaxing step is R2, and the rubber thread 14 in the natural state is When the extension ratio of is R3 (= 1), the extension ratio R2 is the following formula R2>R3+(R1-R3)/2
should be satisfied.

By doing so, the rubber thread 14 having an extension ratio R2 closer to the extension ratio R1 in the stretched state than in the natural state can be cut, and the rubber thread 14 can be reliably and cleanly cut. As described above, the expansion ratio is a ratio R (R=E1/E0) that indicates how many times the total length E1 of the rubber thread 14 in the stretched state is stretched as compared with the total length E0 of the rubber thread 14 in the natural state. is.

Further, as shown in FIG. 7, the stretched states of the first sheet portion 11 and the second sheet portion 12 are relaxed together with the rubber thread 14 . Therefore, by relaxing the elongation ratio of the rubber thread 14 as described above, the sheet portions 11 and 12 can be conveyed while applying an appropriate tension, and the conveyance is stabilized.

The manufacturing apparatus 20 of the first embodiment has an upstream drive roller 30 and a downstream drive roller 31 as shown in FIG. The upstream drive roller 30 and the downstream drive roller 31 are a pair of nip rollers that are rotated around a rotation axis along the CD direction by a drive source (not shown). Both of the pair of nip rollers may be drive rollers, or one may be a drive roller and the other a driven roller.

The upstream drive roller 30 is arranged between the ultrasonic welding device 22 (discharge roller 25) shown in FIG. 3, the cutter roller 26 and the receiving roller 27 (hereinafter also referred to as "rubber thread cutting device"). The upstream drive roller 30 feeds the laminated body 10 ′ in which the rubber thread 14 is arranged between the first sheet portion 11 and the second sheet portion 12 to form the joint portion j to the rubber thread cutting devices 26 and 27 . supply.

The downstream drive roller 31 is arranged downstream of the rubber thread cutting devices 26 and 27 . The downstream drive roller 31 discharges the laminate 10' from the rubber thread cutting devices 26 and 27 and supplies it to downstream processes.

The peripheral speed V1 of the upstream driving roller 30 is set to be faster than the peripheral speed V2 of the downstream driving roller 31 (V1>V2). That is, the amount (length per unit time, e.g., m/sec) of the layered product 10′ delivered by the upstream drive roller 30 toward the rubber thread cutting devices 26, 27 is determined by the downstream drive roller 31. It is larger than the amount of laminate 10' sent out to the process (length per unit time, eg m/sec).

Therefore, between the upstream driving roller 30 and the downstream driving roller 31, the stretched state of the laminate 10' is relaxed, and the stretched state of the rubber thread 14 is also relaxed. Specifically, as shown in FIG. 6B, it is possible to relax the stretched state of the rubber thread 14 at a portion on one side and a portion on the other side of the cutting position Pc, including the cutting position Pc of the rubber thread 14. The rubber thread 14 can be cut while the diameter of the rubber thread 14 is increased. Therefore, the cut end 14a of the rubber thread can be fixed at the first joint pair jP1 (desired joint pair jP).

(Modification 1)
FIG. 8 is an explanatory diagram of the relaxation process and the cutting process of the rubber thread 14 in Modification 1. As shown in FIG. In Modified Example 1, a second upstream drive roller 32 is arranged between the upstream drive roller 30 and the rubber thread cutting devices 26 and 27, and the rubber thread cutting devices 26 and 27 and the downstream drive roller 31 are arranged. A second downstream drive roller 33 is arranged in between.

The second upstream drive roller 32 and the second downstream drive roller 33 are a pair of nip rollers that rotate about a rotation axis along the CD direction by a drive source (not shown). Both of the pair of nip rollers may be drive rollers, or one may be a drive roller and the other a driven roller. The second upstream drive roller 32 feeds the layered product 10 ′ to the rubber thread cutting devices 26 and 27 , and the second downstream drive roller 33 feeds the layered product 10 ′ to the rubber thread cutting devices 26 and 27 . Eject from

The peripheral speed V3 of the second upstream driving roller 32 is set to be slower than the peripheral speed V1 of the upstream driving roller 30 (V3<V1). By doing so, the amount of laminate 10′ sent downstream by the upstream drive roller 30 (eg m/sec) is the amount of laminate 10′ sent downstream by the second upstream drive roller 32 (eg m/s). Therefore, between the upstream driving roller 30 and the second upstream driving roller 32, the stretched state of the laminate 10' is relaxed, and the stretched state of the rubber thread 14 is also relaxed.

Also, the peripheral speed V4 of the second downstream drive roller 33 is set to be faster than the peripheral speed V3 of the second upstream drive roller 32 (V4>V3). By doing so, the amount of laminate 10′ sent downstream by the second upstream drive roller 32 (eg, m/sec) is the amount of laminate 10′ sent downstream by the second downstream drive roller 33. (eg m/s). Therefore, between the second upstream drive roller 32 and the second downstream drive roller 33, the laminate 10' (rubber thread 14) is stretched again.

Also, the peripheral speed V4 of the second downstream drive roller 33 is set to be faster than the peripheral speed V2 of the downstream drive roller 31 (V4>V2). By doing so, the amount of the laminate 10′ sent downstream by the second downstream drive roller 33 (eg, m/sec) is the amount of the laminate 10′ sent downstream by the downstream drive roller 31 (eg, m/s). Therefore, between the second downstream driving roller 33 and the downstream driving roller 31, the stretched state of the laminate 10' is relaxed again, and the stretched state of the rubber thread 14 is also relaxed again.

In this case, the elongation ratio of the rubber thread 14 between the second upstream drive roller 32 and the second downstream drive roller 33, that is, around the cutter blade 261, is between the upstream drive roller 30 and the second upstream drive roller 30. It is higher than the stretch ratio of the rubber thread 14 between the rollers 32 and between the second downstream drive roller 33 and the downstream drive roller 31 . Therefore, the rubber thread 14 that is moderately elongated can be cut, and the rubber thread 14 can be reliably and cleanly cut.

In addition, in a part of the upstream side in the conveying direction of the cutter blade 261 and a part of the downstream side of the conveying direction of the cutter blade 261, the stretched state of the rubber thread 14 is relaxed, and the diameter of the rubber thread 14 is increased. there is Therefore, the cut end portion of the rubber thread 14 is easily fixed at the desired joint portion pair jP. That is, in Modification 1, the rubber thread 14 can be cut in the state shown in FIG. 6C.

Further, in Modification 1, by adjusting the distance between the cutter blade 261 and the second upstream driving roller 32 and the distance between the cutter blade 261 and the second downstream driving roller 33, the cutting position Pc of the rubber thread is adjusted. to the position where the stretched state of the rubber thread 14 is relaxed. Therefore, the diameter of the rubber thread 14 around the joint pair jP distant from the rubber thread cutting position Pc can be increased, not the joint pair (first joint pair jP1) closest to the rubber thread cutting position Pc. That is, the cut end portion 14a of the rubber thread can be fixed at a desired joint portion jP away from the cutting position Pc of the rubber thread.

(Modification 2)
9A and 9B are explanatory diagrams of the relaxation step and the cutting step of the rubber thread 14 in Modification 2. FIG. FIG. 9B is an enlarged view of the periphery of the cutter blade 261. FIG. Note that the first sheet portion 11 and the second sheet portion 12 are omitted in FIG. 9B to avoid complication of the drawing.

The manufacturing apparatus of Modification 2 has the same configuration as that of the above-described embodiment (FIG. 7). However, in Modification 2, the peripheral speed V5 of the cutter roller 26 is set to be faster than the peripheral speed V1 of the upstream driving roller 30 and faster than the peripheral speed V2 of the downstream driving roller 31. (V5>V1>V2).

By doing so, the stretched state of the rubber thread 14 is relaxed between the upstream drive roller 30 and the downstream drive roller 31, as in the above-described embodiment (FIG. 7). Therefore, the rubber thread 14 can be cut with the diameter of the rubber thread 14 increased around the desired joint pair jP, and the cut end of the rubber thread 14 can be fixed at the desired joint pair jP.

Furthermore, in Modification 2, the moving speed (rotating speed) of the cutter blade 261 is faster than the conveying speed of the rubber thread 14 let out by the upstream drive roller 30 . Therefore, as shown in FIG. 9B , after the rubber thread 14 is caught by the cutter blade 261, until the rubber thread 14 is pinched and cut by the cutter blade 261 and the receiving roller 27, the cutter blade 261, which moves at high speed, is threaded. Rubber 14 is pulled. Therefore, a portion of the rubber thread 14 on the upstream side of the cutter blade 261 extends, and the cutter blade 261 can cut the rubber thread 14 while extending in the transport direction (horizontal direction). Therefore, the rubber thread 14 can be reliably and cleanly cut.

Note that the cutter roller 26 (cutter blade 261) and the receiving roller 27 come into contact when the rubber thread 14 is cut. Therefore, the conveying speed of the laminate 10' that has passed between the cutter roller 26 and the receiving roller 27 does not change, and the rubber thread 14 downstream of the cutter roller 26 is also maintained in a relaxed state.

(Modification 3)
10A and 10B are explanatory diagrams of the relaxation step and the cutting step of the rubber thread 14 in Modification 3. FIG. FIG. 10B is an enlarged view of the periphery of the cutter blade 261. FIG. Note that the first sheet portion 11 and the second sheet portion 12 are omitted in FIG. 10B to avoid complication of the drawing.

The manufacturing apparatus of Modification 3 has the same configuration as that of the above-described embodiment (FIG. 7). Therefore, between the upstream drive roller 30 and the downstream drive roller 31, the stretched state of the rubber thread 14 is relaxed. Therefore, the rubber thread 14 can be cut with the diameter of the rubber thread 14 increased around the desired joint pair jP, and the cut end of the rubber thread 41 can be fixed at the desired joint pair jP.

Furthermore, in Modification 3, the cutter blade 261 of the cutter roller 26 pushes down the layered product 10' (rubber thread 14) in its thickness direction to cut it. Therefore, in the vertical direction (in the thickness direction of the laminate 10′), the distance between the cutter blade 261 and the receiving roller 27 is higher than the nip position h1 of the upstream drive roller 30 and the nip position h1 of the downstream drive roller 31. The contact position h2 (cutting position of the rubber thread) is shifted downward in the vertical direction (toward the receiving roller 27).

By doing so, as shown in FIG. 10B , the rubber thread 14 caught on the cutter blade 261 is pushed down by the cutter blade 261 . Therefore, the cutter blade 261 can cut the rubber thread 14 while extending it in the thickness direction of the laminate 10', and the rubber thread 14 can be reliably and cleanly cut.

Although the rotary cutter blade 261 in which the roller is provided with the cutter blade 261 has been taken as an example so far, the present invention is not limited to this. The rubber thread 14 cutting device (other than the modification 2) may be, for example, a device in which at least one of a cutter blade and a receiving blade moves up and down to pinch and cut the rubber thread 14 .

=== Second Embodiment ===
FIG. 11 is an explanatory diagram of the relaxation process and the cutting process of the rubber thread 14 in the second embodiment. The manufacturing apparatus of the second embodiment has a supply roller 50, a conveying device 40, a cutter roller 26, and a discharge roller 51 downstream of the ultrasonic welding device 22 and the discharge roller 25 (see FIG. 3). In the second embodiment, the supply roller 50 supplies the laminated body 10 ′ in which the joint portion j is formed by arranging the rubber thread 14 between the first sheet portion 11 and the second sheet portion 12 to the conveying device 40 . , the rubber thread 14 is cut while the laminate 10 ′ is conveyed by the conveying device 40 .

The conveying device 40 is a substantially drum-shaped device that rotates around a rotation axis along the CD direction, and conveys the laminate 10 ′ along the rotation direction of the conveying device 40 . The conveying device 40 has a plurality of holding portions 41a to 41f that partially hold the laminate 10' at intervals in the rotation direction of the conveying device 40 (that is, the conveying direction of the laminate 10'). The holding portions 41a to 41f have a suction mechanism (not shown), and convey the laminate 10' while adsorbing it to the surfaces of the holding portions 41a to 41f. Further, the holding portions 41a to 41f can be moved in the rotational direction by a drive mechanism (not shown) while rotating in the rotational direction of the conveying device 40, and the intervals between the holding portions 41a to 41f adjacent to each other in the rotational direction can be changed. It's becoming

Further, in the second embodiment, the conveying speed V6 of the layered product 10′ on the upstream side of the conveying device 40 is substantially the same as the conveying speed V6 of the laminated body 10′ by the conveying device 40 (peripheral speed of the conveying device 40). is set to be Therefore, the laminated body 10' (rubber thread 14) transferred from the supply roller 50 to the holding portion (eg, 41a) is maintained in its stretched state.

After that, on the upstream side of the cutter roller 26, the holding portion (example: 41a) moves downstream in the conveying direction so that it approaches the neighboring holding portion (example: 41b) on the downstream side of the holding portion (example: 41a). move to the side. Therefore, the angle formed by the adjacent holding portions 41a to 41f is larger than the angle θ1 when the laminated body 10 is delivered to the holding portions 41a to 41f when the holding portions 41a to 41f approach the cutter roller 26. The angle θ2 is smaller (θ1>θ2).

Further, the laminated body 10' sucked and held by the holding portions 41a to 41f is not displaced in the transport direction. Therefore, the holding portion (eg, 41a) approaches the downstream holding portion (eg, 41b), and the space between the holding portions (eg, 41a and 41b) is narrowed. The stretched state of the laminated body 10' located at is relaxed, and the stretched state of the rubber thread 14 is also relaxed. That is, the conveying device 40 functions as a relaxation section that relaxes the stretched state of the rubber thread 14 .

After that, the cutter blade 261 cuts the rubber thread 14 positioned between the holding portions 41a to 41f. By doing so, the stretched state of the rubber thread 14 can be relaxed around the cutting position of the rubber thread 14, and the cut end portion of the rubber thread 14 can be easily fixed at the desired joint pair jP.

Preferably, a desired joint pair jP to which the cut ends of the rubber thread 14 are to be fixed is positioned on the laminate 10' positioned between the holding parts 41a to 41f. By doing so, the rubber thread 14 can be cut while increasing the diameter of the rubber thread 14 around the desired joint pair jP, and the cut end of the rubber thread 14 can be fixed at the desired joint pair jP.

Although not shown, a receiving portion (receiving blade) for receiving the cutter blade 261 may be provided between the holding portions 41a to 41f.
In addition, the holding portion (eg, 41f) that has delivered the laminate 10′ to the discharge roller 51 has an interval (angle) with the downstream holding portion (eg, 41a) when receiving the laminate 10′ (angle θ1).
Also, although the holding portions 41a to 41f hold the laminated body 10' by suction, the holding portions 41a to 41f are not limited to this. It is sufficient that the laminated body 10' on the holding portions 41a to 41f is not displaced.

=== Third Embodiment ===
FIG. 12 is an explanatory diagram of the relaxation process and the cutting process of the rubber thread 14 in the third embodiment. As in the second embodiment, the manufacturing apparatus of the third embodiment also has a supply roller 50, a conveying device 40, a cutter roller 26, and a discharge roller 51, and conveys the laminate 10' by the conveying device 40. While cutting the thread rubber 14.

Also, the configuration of the conveying device 40 is assumed to be the same. That is, the conveying device 40 has a plurality of holding portions 41a to 41g that partially hold the laminate 10'. The holding portions 41a to 41g rotate in the rotational direction of the conveying device 40, and can change the distance between the holding portions 41a to 41g adjacent to each other in the rotational direction.

However, in the third embodiment, the supply speed V7 of the laminate 10′ by the supply roller 50 (peripheral speed of the supply roller 50) is the conveyance speed V8 of the laminate 10′ by the conveying device 40 (peripheral speed of the conveying device 40). (V7>V8). That is, the amount (eg, m/sec) of the laminate 10′ delivered to the conveying device 40 by the supply roller 50 is greater than the amount (eg, m/sec) of the laminate 10′ conveyed by the conveying device 40. ing. Therefore, the stretched state of the laminated body 10 ′ on the conveying device 40 is relaxed, and the stretched state of the rubber thread 14 is relaxed.

As described above, in the third embodiment, the supply roller 50 and the conveying device 40 function as a relaxation section that relaxes the stretched state of the rubber thread 14 . Further, the conveying speed V8 of the laminated body 10′ by the conveying device 40 means that after the laminated body 10 is delivered to the holding section (eg 41a), the holding section (eg 41a) and the downstream side holding section ( Example: The conveying speed in the period before the interval from 41b) changes.

Further, before the cutter blade 261 cuts the rubber thread 14 between the holding portion (example: 41d) and the holding portion (example: 41c) adjacent on the upstream side, the downstream holding portion (example: 41d) ) moves downstream in the transport direction away from the upstream holding portion (eg 41c). Therefore, the angle formed by the adjacent holding portions 41a to 41g is larger than the angle θ3 when the laminated body 10 is delivered to the holding portions 41a to 41g when the holding portions 41a to 41g approach the cutter roller 26. The angle θ4 is larger (θ3<θ4). By widening the distance between the holding portions 41a to 41g in this way, the laminate 10' positioned between the holding portions (eg, 41d and 41c) is elongated, and the rubber thread 14 is also elongated.

After that, the rubber thread 14 positioned between the holding portions 41a to 41g and extending is cut by the cutter blade 261 and a receiving portion (receiving blade) (not shown). By doing so, the rubber thread 14 can be reliably and cleanly cut.

In addition, the stretched state of the rubber thread 14 is relaxed in a portion on the upstream side and a portion on the downstream side in the conveying direction of the cutting position of the rubber thread 14 . Therefore, the cut end portion of the rubber thread 14 is easily fixed at the desired joint portion pair jP. Preferably, a desired joint pair jP to which the cut ends of the rubber thread 14 are to be fixed is positioned on the holding portions 41a to 41g and on the laminated body 10' in which the stretched state is relaxed. . By doing so, the rubber thread 14 can be cut while increasing the diameter of the rubber thread 14 around the desired joint pair jP, and the cut end of the rubber thread 14 can be fixed at the desired joint pair jP.

In addition, the holding portion (example: 41d) that moves downstream in order to widen the space between the holding portions 41a to 41g has a gap between the holding portion (example: 41d) and the downstream holding portion (example: 41e). It is preferable to move after the rubber thread 14 is cut.

=== Fourth Embodiment ===
13 and 14 are explanatory diagrams of the relaxation process and the cutting process of the rubber thread 14 in the fourth embodiment. As in the second and third embodiments, the manufacturing apparatus of the fourth embodiment also has a supply roller 50, a conveying device 40, a cutter roller 26, and a discharge roller 51, and transports the laminate 10' to the conveying device. The thread rubber 14 is cut while being conveyed by 40 .

A conveying device 40 shown in FIG. 13 is a substantially drum-shaped device that rotates around a rotation axis along the CD direction, and conveys the laminate 10 ′ along the rotation direction of the conveying device 40 . The conveying device 40 includes suction units 42a to 42f for partially sucking the laminate 10′ by a suction mechanism (not shown) and supporting units 43a to 43f for partially supporting the laminate 10′. are arranged alternately in the conveying direction.

The suction units 42a to 42f can be moved in the rotation direction by a drive mechanism (not shown) while rotating in the rotation direction of the conveying device 40. It is changeable. On the other hand, the support portions 43a to 43f rotate while keeping the distance between the support portions 43a to 43f constant. Moreover, the laminated body 10' transferred to the suction portions 42a to 42f is sucked by the surfaces of the suction portions 42a to 42f and is not displaced, and is maintained in the stretched state. On the other hand, the laminated body 10′ transferred to the support portions 43a to 43f can be displaced relative to the support portions 43a to 43f while being transported by the support portions 43a to 43f, and the stretched state can be relaxed. there is

Further, in the fourth embodiment, the transport speed V6 of the layered product 10′ on the upstream side of the transport device 40 is substantially the same as the transport speed V6 of the layered product 10′ by the transport device 40 (peripheral speed of the transport device 40). is set to be Therefore, the laminated body 10' transferred from the supply roller 50 to the suction portion (eg 42a) or the support portion (eg 43a) is maintained in its stretched state.

After that, on the upstream side of the cutter roller 26, the suction portion (example: 42a) is attached to the support portion (example: 43a) and the suction portion (example: 42b) that are adjacent on the downstream side of the suction portion (example: 42a). Move to the downstream side in the transport direction so as to approach. Therefore, the angle formed by the adjacent suction portions 42a to 42f is larger than the angle θ5 when the laminated body 10 is transferred to the suction portions 42a to 42f when the holding portions 41a to 41f approach the cutter roller 26. The angle θ6 is smaller (θ5>θ6).

As the suction portion (eg 42a) approaches the suction portion (eg 42b) on the downstream side and the space between the suction portions (eg 42a and 42b) narrows, the space between the suction portions (eg 42a and 42b) The stretched state of the positioned laminate 10' is relaxed, and the stretched state of the rubber thread 14 is also relaxed. That is, the conveying device 40 functions as a relaxation section that relaxes the stretched state of the rubber thread 14 .

Thereafter, the rubber thread 14 positioned on the suction portions 42a to 42f and extending is cut by the cutter blade 261 and a receiving portion (receiving blade) (not shown). By doing so, the rubber thread 14 can be reliably and cleanly cut.

In addition, the stretched state of the rubber thread 14 is relaxed in a portion on the upstream side and a portion on the downstream side in the conveying direction of the cutting position of the rubber thread 14 . Therefore, the cut end portion of the rubber thread 14 is easily fixed at the desired joint portion pair jP. Preferably, a desired joint pair jP to which the cut end of the rubber thread 14 is to be fixed is positioned in the laminated body 10' located between the suction parts 42a to 42f and relaxed in the stretched state. . By doing so, the rubber thread 14 can be cut while increasing the diameter of the rubber thread 14 around the desired joint pair jP, and the cut end of the rubber thread 14 can be fixed at the desired joint pair jP.

Further, as in a conveying device 40 shown in FIG. 14, suction portions 42a to 42f may be provided inside a hollow cylindrical support drum 40 that continues in the rotating direction of the conveying device 40 . The suction portions 42a to 42f rotate in the rotation direction of the conveying device 40 inside the support drum 40, and the space between the suction portions 42a to 42f can be changed. The support drum 40 rotates in the rotational direction of the conveying device 40 and conveys the layered product 10' delivered on the outer peripheral surface. Further, the support drum 40 is provided with a suction hole 44 a penetrating in the radial direction of the support drum 40 . Therefore, the portions of the support drum 40 that overlap with the suction portions 42a to 42f correspond to the suction portions of the present invention, and convey the layered product 10' while maintaining the stretched state of the layered product 10'. On the other hand, the portions of the support drum 40 that do not overlap with the suction portions 42a to 42f correspond to the support portions of the present invention, and convey the laminate 10' while allowing the laminate 10' to relax in its stretched state.

In the case of the conveying device 40 of FIG. 14 as well, after the laminated body 10' is transferred to the support drum 40 in a stretched state, the distance between the suction portions (eg, 42a and 42b) should be narrowed. By doing so, the stretched state of the laminate 10 ′ positioned between the suction portions (eg, 42 a and 42 b ) is relaxed, and the stretched state of the rubber thread 14 is also relaxed. After that, the rubber thread 14 on the suction portions 42a to 42f, which is maintained in the stretched state, is sandwiched between the cutter blade 261 and the support drum 40 to be cut. By doing so, the cut ends of the rubber thread 14 can be easily fixed at a desired joint portion pair jP while cutting the rubber thread 14 reliably and neatly.

Although the embodiments of the present invention have been described above, the above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit and interpret the present invention. Further, the present invention can be modified and improved without departing from its spirit, and it goes without saying that the present invention includes equivalents thereof.

10 elastic sheet, 10' laminate,
11 first sheet portion, 12 second sheet portion, 14 thread rubber,
20 Elastic sheet manufacturing apparatus 21 Conveying roller group (arrangement part),
22 ultrasonic welding device (joint part forming part),
23 anvil roller, 24 horn roller,
25 ejection roller,
26 cutter roller (cutting part), 261 cutter blade,
27 receiving roller (cutting portion), 271 receiving blade,
30 upstream drive roller, 31 downstream drive roller,
32 second upstream drive roller; 33 second downstream drive roller;
40 transport device, 41a to 41g holding unit,
42a to 42f suction portion, 43a to 43f support portion,
44 support drum, 44a suction hole,
50 supply roller, 51 discharge roller,
j junction, jP junction pair,

Claims (10)

A method for manufacturing a stretchable sheet having a longitudinal direction and a lateral direction, comprising:
disposing the rubber thread stretched in the lateral direction between the first sheet portion and the second sheet portion;
forming a plurality of joints by pressing the first sheet and the second sheet to form a plurality of joints;
a step of relaxing the stretched state of the rubber thread;
a step of cutting the rubber thread at a cutting position in the horizontal direction after the relaxing step;
The plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction,
After the step of cutting, the contracted rubber thread is sandwiched between the pair of joint portions to restrict the lateral position of the rubber thread,
In the lateral direction, when the joint portion pair adjacent to one side of the cutting position is defined as a one side joint portion pair, and the joint portion pair adjacent to the other side of the cutting position is defined as the other side joint portion pair,
In the relaxing step, the stretched state of the rubber thread between the pair of joints on one side and the pair of joints on the other side in the horizontal direction is relaxed,
When the elongation ratio of the rubber thread in the stretched state is R1, the elongation ratio of the rubber thread relaxed in the relaxing step is R2, and the elongation ratio of the rubber thread in the natural state is R3, the elongation ratio is: R2 has the following formula
R2>R3+(R1-R3)/2
A method for producing an elastic sheet, characterized by satisfying A method for manufacturing the elastic sheet according to claim 1 ,
The upstream drive roller supplies a laminate in which the rubber thread is arranged between the first sheet portion and the second sheet portion to the rubber thread cutting device,
a downstream drive roller ejects the laminate from the cutting device;
A method for producing a stretchable sheet, wherein the peripheral speed of the upstream drive roller is faster than the peripheral speed of the downstream drive roller. A method for manufacturing a stretchable sheet having a longitudinal direction and a lateral direction, comprising:
disposing the rubber thread stretched in the lateral direction between the first sheet portion and the second sheet portion;
forming a plurality of joints by pressing the first sheet and the second sheet to form a plurality of joints;
a step of relaxing the stretched state of the rubber thread;
a step of cutting the rubber thread at a cutting position in the horizontal direction after the relaxing step;
The plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction,
After the step of cutting, the contracted rubber thread is sandwiched between the pair of joint portions to restrict the lateral position of the rubber thread,
In the lateral direction, when the joint portion pair adjacent to one side of the cutting position is defined as a one side joint portion pair, and the joint portion pair adjacent to the other side of the cutting position is defined as the other side joint portion pair,
In the relaxing step, the stretched state of the rubber thread between the pair of joints on one side and the pair of joints on the other side in the horizontal direction is relaxed,
The upstream drive roller supplies a laminate in which the rubber thread is arranged between the first sheet portion and the second sheet portion to the rubber thread cutting device,
a downstream drive roller ejects the laminate from the cutting device;
making the peripheral speed of the upstream drive roller faster than the peripheral speed of the downstream drive roller;
a second upstream drive roller between the upstream drive roller and the cutting device feeds the laminate to the cutting device;
a second downstream drive roller between the downstream drive roller and the cutting device ejects the laminate from the cutting device;
making the peripheral speed of the second upstream drive roller slower than the peripheral speed of the upstream drive roller;
Elasticity characterized by making the peripheral speed of the second downstream drive roller faster than the peripheral speed of the second upstream drive roller and faster than the peripheral speed of the downstream drive roller Sheet manufacturing method. A method for manufacturing the elastic sheet according to claim 2 ,
The cutting device has a cutter roller having a cutter blade and a receiving roller facing the cutter roller,
A method for producing a stretchable sheet, wherein the peripheral speed of the cutter roller is faster than the peripheral speed of the upstream drive roller. A method for manufacturing the elastic sheet according to claim 2 ,
A method for producing a stretchable sheet, wherein a cutter blade of the cutting device pushes down the laminate in its thickness direction to cut the laminate. A method for manufacturing a stretchable sheet having a longitudinal direction and a lateral direction, comprising:
disposing the rubber thread stretched in the lateral direction between the first sheet portion and the second sheet portion;
forming a plurality of joints by pressing the first sheet and the second sheet to form a plurality of joints;
a step of relaxing the stretched state of the rubber thread;
a step of cutting the rubber thread at a cutting position in the horizontal direction after the relaxing step;
The plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction,
After the step of cutting, the contracted rubber thread is sandwiched between the pair of joint portions to restrict the lateral position of the rubber thread,
In the lateral direction, when the joint portion pair adjacent to one side of the cutting position is defined as a one side joint portion pair, and the joint portion pair adjacent to the other side of the cutting position is defined as the other side joint portion pair,
In the relaxing step, the stretched state of the rubber thread between the pair of joints on one side and the pair of joints on the other side in the horizontal direction is relaxed,
Cutting the rubber thread while conveying the laminated body in which the rubber thread is arranged between the first sheet portion and the second sheet portion by a conveying device;
The conveying device has a plurality of holding units that partially hold the laminate at intervals in the conveying direction of the laminate,
A method for producing a stretchable sheet, wherein the rubber thread positioned between the holding portions is cut after narrowing the gap between the holding portions. A method for manufacturing a stretchable sheet having a longitudinal direction and a lateral direction, comprising:
disposing the rubber thread stretched in the lateral direction between the first sheet portion and the second sheet portion;
forming a plurality of joints by pressing the first sheet and the second sheet to form a plurality of joints;
a step of relaxing the stretched state of the rubber thread;
a step of cutting the rubber thread at a cutting position in the horizontal direction after the relaxing step;
The plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction,
After the step of cutting, the contracted rubber thread is sandwiched between the pair of joint portions to restrict the lateral position of the rubber thread,
In the lateral direction, when the joint portion pair adjacent to one side of the cutting position is defined as a one side joint portion pair, and the joint portion pair adjacent to the other side of the cutting position is defined as the other side joint portion pair,
In the relaxing step, the stretched state of the rubber thread between the pair of joints on one side and the pair of joints on the other side in the horizontal direction is relaxed,
Cutting the rubber thread while conveying the laminated body in which the rubber thread is arranged between the first sheet portion and the second sheet portion by a conveying device;
The supply roller supplies the laminate to the conveying device,
The supply speed of the laminate by the supply roller is faster than the conveyance speed of the laminate by the conveying device,
The conveying device has a plurality of holding units that partially hold the laminate at intervals in the conveying direction of the laminate,
A method for manufacturing a stretchable sheet, wherein the rubber thread positioned between the holding portions is cut after widening the gap between the holding portions. A method for manufacturing a stretchable sheet having a longitudinal direction and a lateral direction, comprising:
disposing the rubber thread stretched in the lateral direction between the first sheet portion and the second sheet portion;
forming a plurality of joints by pressing the first sheet and the second sheet to form a plurality of joints;
a step of relaxing the stretched state of the rubber thread;
a step of cutting the rubber thread at a cutting position in the horizontal direction after the relaxing step;
The plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction,
After the step of cutting, the contracted rubber thread is sandwiched between the pair of joint portions to restrict the lateral position of the rubber thread,
In the lateral direction, when the joint portion pair adjacent to one side of the cutting position is defined as a one side joint portion pair, and the joint portion pair adjacent to the other side of the cutting position is defined as the other side joint portion pair,
In the relaxing step, the stretched state of the rubber thread between the pair of joints on one side and the pair of joints on the other side in the horizontal direction is relaxed,
Cutting the rubber thread while conveying the laminated body in which the rubber thread is arranged between the first sheet portion and the second sheet portion by a conveying device;
The conveying device has a suction unit that partially sucks the laminate and a support unit that partially supports the laminate, arranged alternately in the conveying direction of the laminate,
A method for producing a stretchable sheet, wherein after narrowing the distance between the suction portions in the conveying direction, the rubber thread positioned on the suction portions is cut. A method for manufacturing the elastic sheet according to any one of claims 1 to 8 ,
A method for producing a stretchable sheet, wherein the distance between the pair of joints in the longitudinal direction is equal to or greater than the diameter of the rubber thread in the stretched state. A stretchable sheet manufacturing apparatus having a longitudinal direction and a lateral direction,
an arrangement portion for arranging the rubber thread stretched in the lateral direction between the first sheet portion and the second sheet portion;
a joining portion forming portion for forming a plurality of joining portions for joining the first sheet portion and the second sheet portion by pressure bonding to each other;
a relaxing portion that relaxes the stretched state of the thread rubber;
a cutting unit that cuts the rubber thread at the cutting position in the horizontal direction after the relaxing step;
The plurality of joint portions have joint portion pairs positioned on both sides of the rubber thread in the longitudinal direction,
After the rubber thread is cut, the contracted rubber thread is sandwiched between the pair of joint portions to restrict the lateral position of the rubber thread,
In the lateral direction, when the joint portion pair adjacent to one side of the cutting position is defined as a one side joint portion pair, and the joint portion pair adjacent to the other side of the cutting position is defined as the other side joint portion pair,
the relaxation portion relaxes the stretched state of the rubber thread between the one-side joint portion pair and the other-side joint portion pair in the lateral direction;
When the elongation ratio of the rubber thread in the stretched state is R1, the elongation ratio of the rubber thread relaxed in the relaxing step is R2, and the elongation ratio of the rubber thread in the natural state is R3, the elongation ratio is: R2 has the following formula
R2>R3+(R1-R3)/2
An elastic sheet manufacturing apparatus characterized by satisfying

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