JP2019103767A - Ultrasonic sealing method and ultrasonic sealing device - Google Patents

Abstract

To allow residual vibration to be damped quickly.SOLUTION: An ultrasonic sealing method comprises repeatedly performing ultrasonic sealing processing on a continuous web (30) of a conveyed absorbent article, thereby forming multiple seals spaced in the conveyance direction of the continuous web (30). The ultrasonic sealing processing involves: a clamping step in which an ultrasonic horn (8) and an anvil (14) clamp the continuous web (30); a seal forming step in which a seal (S) is formed in the continuous web (30) by the ultrasonic horn (8) vibrating upon receiving ultrasonic waves generated by an ultrasonic generator (9); and a clamping release step in which the clamping of the continuous web (30) is released after the ultrasonic generator (9) has stopped generating the ultrasonic waves and the residual vibration remaining in the ultrasonic horn (8) has stopped.SELECTED DRAWING: Figure 10

Description

  The present invention relates to an ultrasonic sealing method and an ultrasonic sealing device.

  It is already well known that an ultrasonic sealing method for forming a plurality of seals at intervals in the conveyance direction of a continuous web by repeatedly performing an ultrasonic sealing process on a continuous web related to an absorbent article to be conveyed There is.

  The ultrasonic sealing process forms a seal portion on the continuous web by vibrating the ultrasonic horn by receiving the ultrasonic wave generated by the ultrasonic wave generator and the holding process in which the ultrasonic horn and the anvil hold the continuous web. Forming a seal portion, and a pinch releasing step of releasing pinching of the continuous web.

JP 2002-355270 A

  Even after the ultrasonic generator stops generating ultrasonic waves, residual vibration as noise remains in the ultrasonic horn, but in the conventional example, when the timing for releasing the continuous web is determined, the residual vibration remains. The presence of vibration was not considered at all. Therefore, the cancellation is performed in a state where residual vibration remains after the ultrasonic generator stops generating the ultrasonic waves.

  And since residual vibration is hard to be settled when holding is not made (released) compared with the case where holding by ultrasonic horn and anvil is made, residual vibration is settled easily after the release. An event that has not occurred has occurred.

  The present invention has been made in view of the above problems, and an object of the present invention is to cause residual vibration to rapidly converge.

The main invention to achieve the above object is
An ultrasonic sealing method for forming a plurality of seal portions at intervals in the conveyance direction of the continuous web by repeatedly performing ultrasonic sealing processing on the continuous web related to the absorbent article to be conveyed,
The ultrasonic sealing process is
A pinching step in which an ultrasonic horn and an anvil pinch the continuous web;
A sealing portion forming step of forming the sealing portion on the continuous web by receiving ultrasonic waves generated by an ultrasonic generator and vibrating the ultrasonic horn;
A sandwiching release step of releasing the sandwiching of the continuous web after the ultrasonic generator stops the generation of ultrasonic waves and the residual vibration remaining in the ultrasonic horn stops;
It is an ultrasonic sealing method characterized by having.

  Other features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

  According to the present invention, it is possible to quickly converge residual vibration.

The upper drawing of FIG. 1 is a perspective view showing the unfolded state of the continuous web 30, and the lower drawing of FIG. 1 is a perspective view showing the continuous web 30 in a state of being conveyed to the sealing device 1. FIG. 9 is a cross-sectional view showing a state in which the continuous web 30 is held between the ultrasonic horn 8 and the anvil 14, and is a cross-sectional view along the line IX-IX in the lower part of FIG. It is sectional drawing which shows the state by which the continuous web 30 was clamped by the ultrasonic horn 8 and the anvil 14, and is the lower figure of FIG. 1, and XX sectional drawing of FIG. It is the figure which showed the seal | sticker apparatus 1 which concerns on this Embodiment, and is II sectional drawing of FIG. It is a figure which shows the rotary drum 5 of the sealing apparatus 1, and its internal structure. It is an explanatory view for explaining operation of a rocking drive part. It is the schematic which showed a mode that the sealing unit 10 clamped the continuous web 30. FIG. It is an enlarged view which shows the internal structure of the holding | maintenance part 52. FIG. It is an image figure which shows the operation state of the seal | sticker apparatus 1. FIG. It is an image figure which shows the relationship between the vibration area of the ultrasonic horn 8 which concerns on an ultrasonic sealing process, and the clamping area of continuous web 30. FIG.

  At least the following matters will be made clear by the present specification and the description of the accompanying drawings.

An ultrasonic sealing method for forming a plurality of seal portions at intervals in the conveyance direction of the continuous web by repeatedly performing ultrasonic sealing processing on the continuous web related to the absorbent article to be conveyed,
The ultrasonic sealing process is
A pinching step in which an ultrasonic horn and an anvil pinch the continuous web;
A sealing portion forming step of forming the sealing portion on the continuous web by receiving ultrasonic waves generated by an ultrasonic generator and vibrating the ultrasonic horn;
A sandwiching release step of releasing the sandwiching of the continuous web after the ultrasonic generator stops the generation of ultrasonic waves and the residual vibration remaining in the ultrasonic horn stops;
An ultrasonic sealing method characterized by having.

  According to such an ultrasonic sealing method, it is possible to quickly converge the residual vibration.

Such an ultrasonic sealing method
It is desirable that the time from when the residual vibration stops to when the holding of the continuous web is released is longer than the time from when the ultrasonic generator stops generating the ultrasonic wave to when the residual vibration stops.

  According to such an ultrasonic sealing method, it is possible to allow a time for releasing the holding of the continuous web after the residual vibration stops, and there is a variation in the length (time) of the residual vibration section. Even if the residual vibration converges, it is possible to reliably perform the release of the clamping.

Such an ultrasonic sealing method
The time from when the residual vibration stops to when the holding of the continuous web is released is the time from when the ultrasonic horn and the anvil hold the continuous web until when the ultrasonic generator generates ultrasonic waves. Longer than is desirable.

  According to such an ultrasonic sealing method, it is possible to allow a time for releasing the holding of the continuous web after the residual vibration stops, and there is a variation in the length (time) of the residual vibration section. Even if the residual vibration converges, it is possible to reliably perform the release of the clamping.

Such an ultrasonic sealing method
It is preferable that the time from the stop of the residual vibration to the release of the holding of the continuous web is shorter than the time from the generation of the ultrasonic wave to the stop of the ultrasonic wave generator.

  According to such an ultrasonic sealing method, it is possible to quickly converge the residual vibration.

Such an ultrasonic sealing method
In the holding step, it is preferable that the continuous web be held in a state where the ultrasonic horn is not vibrating.

  According to such an ultrasonic sealing method, it becomes possible to suppress careless vibration and to vibrate the ultrasonic horn promptly.

Such an ultrasonic sealing method
In the sealing portion forming step, the ultrasonic wave generator may stop the generation of the ultrasonic wave when the energy of the ultrasonic vibration reaches a predetermined amount after the ultrasonic wave generator generates the ultrasonic wave. desirable.

  According to such an ultrasonic sealing method, the ultrasonic generator can emit a predetermined amount of ultrasonic vibration energy, and the seal portion can be stably formed.

Such an ultrasonic sealing method
In the holding step, it is preferable that the flat surface of the ultrasonic horn and the flat surface of the anvil hold the continuous web.

  According to such an ultrasonic sealing method, it is possible to rapidly converge the residual vibration of the ultrasonic horn.

Such an ultrasonic sealing method
The continuous web is conveyed by rotation of the rotating member in a state of being wound around the outer peripheral surface of the rotating member,
A plurality of members of the ultrasonic horn and the anvil are provided at equal intervals on the outer peripheral surface,
A plurality of other members are provided on the rotating member corresponding to each one of the members, and are provided so as to be able to contact or separate the one member with the continuous web interposed therebetween,
When the ultrasonic horn and the anvil rotate with the rotation of the rotating member to reach a predetermined first angular position, the other member abuts on the one member to hold the continuous web. And when the ultrasonic horn and the anvil reach a predetermined second angular position, the other member separates from the one member to release the holding.
It is desirable that the ultrasonic wave generator generates an ultrasonic wave when the ultrasonic horn and the anvil rotate with the rotation of the rotating member to reach a predetermined third angular position.

  According to such an ultrasonic sealing method, it becomes possible to generate an ultrasonic wave reliably at a desired timing regardless of the rotational speed of the rotating member.

Such an ultrasonic sealing method
Assuming that the difference between the third angle and the second angle is θ, and the time from when the ultrasonic generator generates an ultrasonic wave to when the residual vibration stops is T,
It is desirable that the continuous web be conveyed by rotating the rotating member at an angular velocity of θ / T or less.

  According to such an ultrasonic sealing method, it is possible to rapidly converge the residual vibration of the ultrasonic horn.

Such an ultrasonic sealing method
When the plurality of seals are formed in the low speed mode in which the rotating member is rotated at the first speed to convey the continuous web, the rotating member is rotated at the second speed higher than the first speed. It is desirable that the time from when the residual vibration stops to when the holding of the continuous web is released is longer than when the plurality of seal portions are formed in the high speed mode in which the continuous web is conveyed.

  According to such an ultrasonic sealing method, it is possible to adjust the time from the end of the residual vibration to the release of the clamping by the selection of the operation mode (selection of the transport speed of the continuous web).

Such an ultrasonic sealing method
It is desirable that the other member be in contact with or separated from the one member by swinging.

  According to such an ultrasonic sealing method, it is possible to realize a reliable holding mechanism with a simple structure.

Such an ultrasonic sealing method
After the ultrasonic horn and the anvil release the sandwiching of the continuous web in the ultrasonic sealing process, the ultrasonic generator superimposes on the ultrasonic horn in the next ultrasonic sealing process by the ultrasonic horn. It is desirable to execute a frequency adjustment process to adjust the frequency of the ultrasonic wave generated by the ultrasonic wave generator to the ultrasonic horn until the generation of the sound wave is started.

  According to such an ultrasonic sealing method, the frequency adjustment process is performed in the state where the residual vibration is stopped. Therefore, it is possible to adjust the frequency appropriately.

A conveying device for conveying the continuous web relating to the absorbent article;
An ultrasonic generator that generates ultrasonic waves,
An ultrasonic horn which forms a seal portion on a continuous web conveyed by the conveyance device by receiving and vibrating the ultrasonic wave generated by the ultrasonic wave generator;
An anvil for clamping the continuous web in cooperation with the ultrasonic horn;
The ultrasonic horn vibrates in a state of sandwiching the continuous web in cooperation with the anvil, and repeatedly performs an ultrasonic sealing process for forming the seal portion on the continuous web, thereby forming the continuous web An ultrasonic seal device that forms a plurality of the seal portions at intervals in the transport direction, the ultrasonic seal device comprising:
The ultrasonic horn and the anvil release the holding of the continuous web after the ultrasonic generator stops generating ultrasonic waves and residual vibration remaining in the ultrasonic horn stops. Ultrasonic sealing device.

  According to such an ultrasonic sealing device, the same operation and effect as those of the above-described ultrasonic sealing method can be obtained.

=== About the ultrasonic sealing method according to the present embodiment ===
The ultrasonic sealing method according to the present embodiment is used in an ultrasonic sealing device (hereinafter referred to as a sealing device 1). And, as shown in the lower part of FIG. 1, the sealing device 1 is applied to the continuous web 30 (continuous web 30 in which the base material of the absorbent article is overlapped) related to the absorbent article to be transported in the continuous production line of the absorbent article. On the other hand, the ultrasonic sealing process is repeatedly performed to form a plurality of seal portions S at intervals in the transport direction of the continuous web 30.

<<< Continuous Web 30 Relating to Absorbent Article >>>
First, taking the pants-type disposable diaper as an example, the continuous web 30 according to the absorbent article of the present embodiment will be described.

  The continuous web 30 which concerns on this Embodiment is conveyed by the sealing apparatus 1 in the folded state, as shown to the lower figure of FIG. FIG. 2 shows a state in which the ultrasonic horn 8 and the anvil 14 sandwich the continuous web 30 to form the seal portion S on the continuous web 30, and shows a section IX-IX in the lower view of FIG. FIG. 3 shows a lower view of FIG. 1 and an X-X cross section of FIG.

  The lower part of FIG. 1 shows a state in which the ultrasonic horn 8 and the anvil 14 of the seal device 1 form the seal portion S on the continuous web 30. After forming the seal portion S on the continuous web 30, by cutting along the cutting line C-C between the adjacent seal portion S and the seal portion S, a pants-type disposable which is the absorbent article of the present embodiment Diapers are manufactured. Further, the upper view of FIG. 1 shows the unfolded state immediately before the continuous web 30 is conveyed to the sealing device 1.

  As shown in the upper view of FIG. 1, in the band-like body in which the continuous web 30 is developed, the first sheet 32 is located on the back side of the drawing, and the second sheet 31 is superimposed thereon. The first sheet 32 is wider than the second sheet 31, and the side edge 32 a of the first sheet 32 is the side of the second sheet 31 on one side 30 A shown in the upper view of FIG. 1. It is folded so that it is piled up. Similarly, on the other side 30 B, the side edge 32 b of the first sheet 32 is folded so as to be superimposed on the second sheet 31. This folded state is shown in FIG.

  Then, as shown on the waist side of FIG. 3, on one side 30A of the strip, a plurality of first waist bands 35 are sandwiched between the first sheet 32 and the second sheet 31. . Further, on the other side 30 </ b> B of the strip, a plurality of second waist bands 36 are sandwiched between the first sheet 32 and the second sheet 31. The first waist band 35 and the second waist band 36 are disposed in parallel with each other and extend linearly in the conveyance direction of the strip.

  Further, as shown in the leg side of FIG. 3, a plurality of first leg bands 37 and a plurality of second leg bands 38 are provided between the first sheet 32 and the second sheet 31. There is. As shown in the upper view of FIG. 1, the first leg band 37 and the second leg band 38 extend in the conveyance direction of the strip in a state of being curved in a wave shape. Then, in a region surrounded by the first leg band 37 and the second leg band 38, a leg hole 34 which is a leg insertion portion when the pants are formed is formed.

  The first waist band 35, the second waist band 36, the first leg band 37, and the second leg band 38 are stretched at a predetermined magnification in the conveyance direction of the strip, and the first sheet 32 and the second Between the seat 31 and the seat. Then, the first sheet 32 and the second sheet 31 and the first waist band 35, the second waist band 36, the first leg band 37, and the second leg band 38 sandwiched between them are hot melt adhesives. Etc. are bonded to each other.

  The first sheet 32 and the second sheet 31 are air-permeable and liquid-blocking, and can be fused by heat. For example, it is a spunbonded nonwoven fabric or a meltblown nonwoven fabric formed of thermoplastic synthetic fibers, or a laminate of the nonwoven fabric. Alternatively, one of the first sheet 32 and the second sheet 31 may be the non-woven fabric, and the other may be a breathable plastic film.

  The first waist band 35, the second waist band 36, the first leg band 37, and the second leg band 38 are elastic stretchable members such as thread-like or band-like rubber, synthetic rubber, and the like.

  On the surface of the second sheet 31, a liquid absorber 33 is provided between the leg holes 34 and the leg holes 34. The liquid absorbent body 33 has an hourglass shape or a rectangular shape, and is disposed at a predetermined interval in the transport direction of the strip. The liquid absorber 33 is ground pulp, a mixture of ground pulp and a water-absorbing polymer (SAP), a laminate of hydrophilic non-woven fabrics, air-laid pulp, and the like. These absorbents are wrapped in a liquid-permeable top sheet. Each liquid absorbent body 33 is bonded to the surface of the second sheet 31 with a hot melt adhesive or the like.

  The top sheet is formed of a spunlaced non-woven fabric, an air-through non-woven fabric, a plastic film having liquid permeation holes, or the like.

  It is a continuous web 30 shown in the lower part of FIG. 1 that the strip shown in the upper part of FIG. 1 is folded in two by the center line O1-O1 extending in the longitudinal direction. As described above, the continuous web 30 is conveyed to the sealing device 1 in the form shown in the lower part of FIG. Then, when the continuous web 30 is conveyed to the sealing device 1, the ultrasonic horn 8 and the anvil 14 provided in the sealing device 1 are located at positions between the adjacent liquid absorbers 33 and 33, A plurality of stacked first sheets 32 and second sheets 31 are sandwiched and sealed.

  Further, in the present embodiment, as shown in FIG. 3, in the middle portion of the continuous web 30 sandwiched between the ultrasonic horn 8 and the anvil 14, two first sheets 32 and two second sheets are provided. A total of 4 sheets with 31 are stacked, and the thickness is the smallest. On the side to be the waist side, in addition to the four sheets, the folded back of both side edges of the first sheet 32 is overlapped, and further, the first waist band 35 and the second waist band 36 intervene to make the thickness the largest. ing. On the leg side which is the leg hole 34 side, the four sheets and the first leg band 37 and the second leg band 38 intervene, and the thickness on the leg side is larger than that of the middle portion, and It is smaller than the west side.

  The first sheet 32 and the second sheet 31 are formed of a heat-fusible material, generate internal heat by vibration given from the ultrasonic horn 8, and each sheet is formed on the anvil facing surface 14a of the anvil 14 It welds according to the shape of a micro convex pattern, and seal part S is formed.

  In the example shown in the lower part of FIG. 1, the pattern of the seal portion S formed in a minute convex pattern is formed so that fine seal lines form a row. After the seal portion S is formed by the seal device 1, a cutting line C-C between the adjacent seal portion S and the seal portion S is cut to complete a pant-type disposable diaper as an absorbent article.

  In addition, although manufacture of the underpants type disposable diaper demonstrated as an example of an absorbent article, the absorbent article manufactured by the sealing apparatus 1 of this invention may be a sanitary napkin, a panty liner, etc.

<<< About the sealing device 1 >>>
Next, the seal device 1 will be described. FIG. 4 is a cross-sectional view (a cross-sectional view along the line I-I in FIG. 9) showing the seal device 1 according to the present embodiment. FIG. 5 is a view showing the rotary drum 5 of the sealing device 1 and the internal structure thereof.

  The seal device 1 includes a rotary member drive unit, a rotary member (corresponding to a transport device), a seal unit 10, an ultrasonic wave generator 9, a swing support member 50, and a swing drive unit.

  As shown in FIG. 4, the rotation member drive unit includes a rotation shaft 3a, a bearing 3, a ball bearing 3b, a timing wheel 2, a toothed belt (not shown), and a motor (not shown). There is. A bearing unit 3 is provided on a fixed table 4 which is a fixed unit, and a rotary shaft 3 a is rotatably supported by a ball bearing 3 b held by the bearing unit 3. In FIG. 4, the center line of the rotation axis 3 a is indicated by a rotation center line OO.

  The timing wheel 2 having teeth on its outer periphery is fixed to the base end on the right side of FIG. 4 of the rotation shaft 3a, and a toothed belt is hung along the outer periphery of the timing wheel 2. Then, power from a drive source having a motor is applied from the toothed belt to the timing wheel 2, and the rotation shaft 3a continuously rotates counterclockwise as viewed from the left side of FIG.

  The rotating member is for conveying the continuous web 30, and includes a rotating base 6 and a rotating drum 5, as shown in FIG. The rotating member is fixed to the rotating shaft 3a and is rotated by the rotating member drive unit. Specifically, the rotary base 6 is fixed to the rotary shaft 3a, and the rotary drum 5 is fixed to the rotary base 6, and rotates with the rotary shaft 3a. The rotary base 6 is opposed in parallel to the fixed table 4 with an interval in order to secure the installation portions of the rocking support member 50 and the rocking drive unit.

  As shown in FIGS. 4 and 5, a plurality of rectangular windows 5a extending in parallel with the rotation center line OO are formed on the outer peripheral surface 5A of the rotary drum 5. The windows 5a are formed at equal pitches in the circumferential direction of the rotary drum 5, and in the present embodiment, the windows 5a are provided at six positions at an arrangement angle of 60 degrees with respect to the rotation center line O-O. ing.

  The seal unit 10 includes an ultrasonic horn 8, a booster 7b, a converter 7a, and an anvil 14, and is provided on a rotating member.

  Accordingly, the seal unit 10 rotates with the rotary base 6 and the rotary drum 5. In the present embodiment, as shown in FIG. 5, a plurality of (six) seal units 10 are provided at an arrangement angle of 60 degrees at equal intervals along the circumferential direction of the rotating member. Hereinafter, these seal units 10 will be referred to as a seal unit S1, a seal unit S2, a seal unit S3, a seal unit S4, a seal unit S5, and a seal unit S6 in order along the circumferential direction.

  The ultrasonic horn 8 is fixed to the rotary base 6 inside the rotary drum 5 as shown in FIG. The ultrasonic horn 8 and the devices connected to the ultrasonic horn 8 are arranged radially around the rotation center line O-O, and the arrangement angle is equal to the arrangement angle of the window 5a. I do. Then, as shown in FIG. 5, each ultrasonic horn 8 protrudes outward from the window 5a of the rotary drum 5 with a height h, and the horn opposing surface 8a at the tip of the ultrasonic horn 8 has a rotation center It is directed outward in the normal direction (radial direction) from the line OO, and the horn opposing surface 8a is located parallel to the rotation center line OO.

  The anvil 14 is fixed to the support portion 70 provided in the holding portion 52 of the rocking support member 50, and moves so as to be in contact with and separated from the horn facing surface 8a as the rocking support member 50 is rocked. That is, the anvil 14 moves between a position in contact with the ultrasonic horn 8 and a position rotated about 90 degrees away.

  The seal unit 10 will be described in more detail later.

  As shown in FIG. 4, the swing support member 50 includes a swing portion 51 and a holding portion 52, and the swing portion 51 and the holding portion 52 are fixed. And the anvil 14 is being fixed to the support part 70 provided in the holding part 52. As shown in FIG. The swing support member 50 is provided on the rotation member. Accordingly, the swing support member 50 rotates with the rotary base 6 and the rotary drum 5. The holding unit 52 will be described in more detail later.

  FIG. 6 is an explanatory view for explaining the swing operation of the swing support member 50. As shown in FIG. As shown in FIG. 6, the rotary base 6 has a regular hexagonal shape in front view. The six rocking support members 50 are provided at the center of each side of the regular hexagon at an interval of 60 degrees, and the arrangement angle of the rocking support members 50 matches the arrangement angle of the ultrasonic horn 8.

  As shown in FIG. 4, each rocking portion 51 is rockably supported on each side of the regular hexagon of the rotary base 6 by a rocking shaft 51A, and the rocking shaft 51A has a rotation center line O-. This direction is orthogonal to O. Therefore, the swing support member 50 (the holding portion 52) can swing the anvil 14 in the radial direction centering on the rotation center line O-O about the swing shaft 51A.

  In the rocking drive unit, as shown in FIG. 4, a cam member 60 constituting the rocking drive unit is fixed to the surface of the fixed table 4 opposed to the rotary base 6. The cam member 60 is a flat plate having a predetermined thickness dimension, and as shown in FIG. 6, a cam groove 61 serving as a cam locus is formed on the front surface. The cam groove 61 is continuous around the rotation center line OO. The depth direction of the concave portion of the cam groove 61 is parallel to the rotation center line OO.

  As shown in FIGS. 4 and 6, link mechanisms are provided between the respective swinging portions 51 and the cam members 60. In this link mechanism, the drive link 53 is rotatably supported via the first connecting shaft 51B provided in the swinging portion 51 in a direction orthogonal to the rotation center line OO.

  On the back surface of the rotation base 6, a base 54A of a rotation link 54 is rotatably supported by a support shaft 54a. The axial direction of the support shaft 54a is parallel to the rotation center line OO. The distal end of the drive link 53 is rotatably coupled to the distal end of the arm 54 B of the pivot link 54 via the second connection shaft 55. The axial direction of the second connection shaft 55 is parallel to the rotation center line OO.

  A drive member 56 is attached to the pivot link 54. The drive member 56 includes a drive support 56a fixed so as not to rotate on the middle portion of the rotation link 54, and a follower 56b provided on the drive support 56a. Then, the follower 56 b can move in the cam groove 61. The follower 56 b rolls in the cam groove 61 or slides without rolling.

  In addition, in FIG. 6, the drive support body 56a is abbreviate | omitted and the relative positional relationship of the rotation link 54, the follower 56b, and the drive link 53 is shown.

  As shown in FIG. 6, when the rotary base 6 rotates, the follower 56 b moves along the cam groove 61. At this time, the distance between the follower 56 b and the rotation center line OO changes in accordance with the shape of the cam groove 61. In accordance with this change, the pivoting link 54 is pivoted, and the pivoting support member 50 is further pivoted through the drive link 53.

  As described above, the swing support member 50 is rotated by the cam groove 61, but while the seal unit 10 moves from the angular position A2 to the angular position A3 shown in FIG. As shown, the swing support member 50 pivots toward the outer peripheral surface 5A of the rotary drum 5 and reaches the contact position. Also, while moving from the angular position A0 to the angular position A1 shown in FIG. 6, the swing support member 50 is directed approximately 90 degrees toward the fixed table 4 as shown by the seal unit 10 in the lower part of FIG. It is pivoted to the retracted position (see FIG. 9).

<<< About the seal unit 10 and the ultrasonic wave generator 9 >>>
FIG. 7 is a schematic view showing the seal unit 10 holding the continuous web 30. As shown in FIG.

  In the seal unit 10, the converter 7a performs mechanical ultrasonic vibration on the ultrasonic signal generated (generated) by the ultrasonic generator 9 in a state in which the ultrasonic horn 8 and the anvil 14 sandwich the continuous web 30 being conveyed. , And received by the ultrasonic horn 8 via the booster 7b. And the seal part S is formed in the continuous web 30 by vibrating the ultrasonic horn 8 which received mechanical ultrasonic vibration.

  In the present embodiment, the ultrasonic generators 9 that emit ultrasonic waves to each of the six sealing units 10 are different from one another. That is, one ultrasonic wave generator 9 is disposed in each of the plurality of seal units 10. Therefore, as shown in FIG. 7, one seal unit 10 has one ultrasonic horn 8, one booster 7b, one converter 7a and one anvil 14 and is connected to one ultrasonic wave generator 9. ing. The ultrasonic wave generator 9 is provided outside the rotating member via a current collection tube (not shown). Further, six members (one ultrasonic horn 8 in the present embodiment) of the ultrasonic horn 8 and the anvil 14 are provided at equal intervals on the outer peripheral surface 5A, and the other member (this embodiment) , Six anvils 14) are provided on the rotating member corresponding to each one member (the ultrasonic horn 8), and the continuous web 30 is held in contact with the one member (the ultrasonic horn 8). It is provided releasably. Then, the other member (anvil 14) comes in contact with and separates from one member (the ultrasonic horn 8) by swinging.

  The ultrasonic generator 9 is a device that emits ultrasonic waves (ultrasonic electric signals). The frequency of ultrasonic waves emitted by the ultrasonic generator 9 (hereinafter also referred to as ultrasonic frequency) is the natural frequency of the ultrasonic horn 8 (resonance frequency. Strictly speaking, ultrasonic waves including the converter 7a and the booster 7b. The natural frequency of the stack, which is herein described as the natural frequency of the ultrasonic horn 8). In other words, the size (length) of the ultrasonic horn 8 so that the ultrasonic frequency (in the present embodiment, 20 kHz) emitted by the ultrasonic generator 9 becomes equal to the natural frequency of the ultrasonic horn 8 Is designed.

  The converter 7a is connected to the ultrasonic generator 9 and converts the ultrasonic electric signal generated by the ultrasonic generator 9 into mechanical vibration. The converter 7a is provided with a piezoelectric element, and the conversion is performed by the piezoelectric element.

  The booster 7b is connected to the converter 7a and amplifies the vibration transmitted from the converter 7a.

  The ultrasonic horn 8 is connected to the booster 7b, and receives the ultrasonic wave emitted by the ultrasonic generator 9 (the converter 7a receives the ultrasonic wave in the form of mechanical vibration because it has been converted to mechanical vibration) (By applying mechanical energy by vibration to the continuous web 30) to generate frictional heat at the bonding surface of the overlapping substrates of the continuous web 30. As a result, the base material is dissolved, and the seal portion S is formed on the continuous web 30.

  The anvil 14 is a member that clamps and seals the continuous web 30 in cooperation with the ultrasonic horn 8. A convex portion 14B is formed on the surface of the anvil 14 (see FIG. 8), and the surface of the convex portion 14B is an anvil facing surface 14a facing the ultrasonic horn 8. The anvil facing surface 14 a is a pattern surface for setting the pattern shape of the seal formed on the continuous web 30. The anvil 14 is fixed to a support portion 70 of a first elastic member 71 and a second elastic member 72, which will be described later, provided inside the holding portion 52 so that the pattern surface faces the outside of the holding portion 52.

<About the frequency adjustment (tuning) function of the ultrasonic wave generator 9>
By the way, the size (length) of the ultrasonic horn 8 may change due to wear and tear due to aging and temperature change. Then, when the length of the ultrasonic horn 8 changes, its natural frequency also changes. Then, if the natural frequency changes, the ultrasonic frequency generated by the ultrasonic generator 9 will not be matched with the natural frequency, and problems such as seal failure of the continuous web 30 may occur. .

  In order to suppress the occurrence of such inconveniences, the ultrasonic generator 9 has a frequency adjustment (tuning) function as a standard function to adjust the frequency of ultrasonic waves emitted from the ultrasonic generator 9 to the ultrasonic horn 8 . At the time of frequency adjustment, the ultrasonic generator 9 actually emits an ultrasonic wave for frequency adjustment to detect an ultrasonic frequency corresponding to the natural frequency of the ultrasonic horn 8. Then, the detected ultrasonic frequency is used in the next sealing portion forming process by the ultrasonic horn 8.

  In the present embodiment, the adjusted (detected) frequency is temporarily stored in a storage unit such as a memory provided in the ultrasonic wave generator 9. Then, at the next sealing portion forming process, the frequency is called from the storage portion, and the ultrasonic generator 9 starts emitting ultrasonic waves at the ultrasonic wave number.

  In addition, when the ultrasonic wave generator 9 which concerns on this Embodiment performs a seal | sticker part formation process, the change of the ultrasonic wave frequency by vibrating in the state which the ultrasonic horn 8 and the anvil 14 pinched | continuousd the continuous web 30. Has a function (different from the tuning function) of forming the seal portion S while following and adjusting as a standard function. That is, even in the sealing portion forming process, the natural frequency may change momentarily, but the ultrasonic generator 9 changes the ultrasonic frequency following the change of the natural frequency. Therefore, in the present embodiment, the ultrasonic frequency acquired by the frequency adjustment function is used only at the beginning of the ultrasonic wave.

  Further, in the present embodiment, the amplitude of the ultrasonic wave emitted by the ultrasonic wave generator 9 in the frequency adjustment is smaller than the amplitude of the ultrasonic wave emitted by the ultrasonic wave generator 9 when forming the seal portion S. . The ultrasonic wave generated by the ultrasonic wave generator 9 in the frequency adjustment does not need to have an amplitude sufficient to melt the continuous web 30, as long as the ultrasonic wave frequency corresponding to the natural frequency of the ultrasonic wave horn 8 can be detected. Therefore, in the present embodiment, the amplitude of the ultrasonic wave emitted by the ultrasonic wave generator 9 in the frequency adjustment is about 5% of the amplitude of the ultrasonic wave emitted by the ultrasonic wave generator 9 when forming the sealing portion S. ing. Therefore, it becomes possible to suppress the power consumed when the ultrasonic wave generator 9 adjusts the frequency.

<<< Regarding holding unit 52 >>>
FIG. 8 is an enlarged view showing the internal structure of the holder 52. As shown in FIG. The holding portion 52 internally includes a first elastic member 71 and a second elastic member 72, and the anvil 14 is fixed to the support portion 70 of the first elastic member 71 and the second elastic member 72. The first elastic member 71 and the second elastic member 72 are aligned in the width direction of the rotary drum 5, that is, in the direction along the rotation center line OO. Then, the holding portion 52 causes the anvil 14 to move so as to be moved toward and away from the ultrasonic horn 8 by the rocking drive portion, and at the contact position where the anvil 14 and the ultrasonic horn 8 contact each other. The ultrasonic horn 8 clamps the continuous web 30.

  The first elastic member 71 and the second elastic member 72 are softly deformable and elastically deformable bags made of a material such as rubber or the like which can be elastically deformed, or a material in which a reinforcing material is incorporated in the rubber. The air damper or the air spring has a (casing) and air is supplied as a fluid to the hollow portion of the bag body, and the inside is set to a predetermined pressure by the air pressure.

  As shown in FIG. 8, the first elastic member 71 and the second elastic member 72 are fixed to the mounting surface 52B of the holding portion 52 via the first fixing plate 71A and the second fixing plate 71B on the mounting side, respectively. . A support 70 is fixed to the pressing side of the first elastic member 71 and the second elastic member 72, and the anvil 14 is fixed to the support 70. In a state in which the anvil 14 is not in contact with the ultrasonic horn 8, the fluid pressure inside the first elastic member 71 and the second elastic member 72 presses the support portion 70 against the inner surface 52 c of the frame 52 a.

  A first nozzle 73 and a second nozzle 74 are provided on the first fixing plate 71A and the second fixing plate 71B, respectively, and a first air pipe 75 and a second nozzle 74 are provided on the first nozzle 73 and the second nozzle 74, respectively. Two air pipes 76 are connected. That is, each of the first elastic member 71 and the second elastic member 72 has an air supply portion so that the internal pressure can be set individually.

  As described above, the continuous web 30 according to the present embodiment is a continuum of the above-described pants-type disposable diaper, and as shown in FIG. 3, the ultrasonic horn 8 and the anvil 14 form the seal portion S. The continuous web 30 of the part is not flat. That is, the thickness is largest at the waist side, thinner at the middle, and larger at the leg side. Therefore, the continuous webs 30 to be sealed are partially different in thickness, and their surfaces are uneven.

  And, even when the portion where the seal portion S is formed is not uniform in thickness as in the pants-type disposable diaper, and the thickness locally changes, the anvil 14 has air inside the bag-like elastic body ( Since the fluid damper is pressurized toward the ultrasonic horn 8 by the air damper in which the fluid is enclosed, the anvil facing surface 14 a can flexibly cope with the change in thickness of the continuous web 30. That is, by the pressure inside the first elastic member 71 and the second elastic member 72, the ultrasonic horn 8 and the anvil 14 can be substantially uniformly pressurized at each location of the seal portion S of the continuous web 30. . Therefore, it is possible to make the seal quality in each place of the seal portion S uniform.

  Further, the internal pressure inside the bag of the first elastic member 71 and the second elastic member 72 can be controlled by the supply of air pressure from the first nozzle 73 and the second nozzle 74. Therefore, control to change the internal pressure in the bag is easy according to the material and structure of the continuous web 30 to be sealed. Therefore, even when the structure of the continuous web 30 is changed and the seal pattern of the anvil facing surface 14a is changed accordingly, the setting of the setup can be completed only by changing the internal pressure in the bag. The sealing work can always be performed under the optimum conditions.

<<< Operation of Seal Device 1 >>>
Next, the operation of the seal device 1 will be described using FIGS. 1 to 6 and 9. FIG. 9 is an image diagram showing an operating state of the seal device 1.

  As shown in FIG. 5, the continuous web 30 is wound around the supply conveyance roll 21 and conveyed to the outer peripheral surface 5 </ b> A of the rotating drum 5. The continuous web 30 is wound at an angle of about 180 degrees around the outer peripheral surface 5A of the rotary drum 5 (more specifically, the horn opposing surface 8a of the ultrasonic horn 8 protruding from the outer peripheral surface 5A) at the discharge portion (ii) It is separated from the rotary drum 5, wound around the discharge conveyance roll 22, and pulled out to the outside.

  The continuous web 30 is continuously fed into the supply portion (i) at a constant speed, and in the sealing device 1, the rotational power is transmitted to the timing wheel 2, and the rotating shaft 3a and the rotating drum 5 as a rotating member The rotation base 6 rotates counterclockwise in FIGS. 5 and 9 at a constant angular velocity.

  Here, the continuous web 30 contacts the horn opposing surface 8 a of the ultrasonic horn 8 protruding from the outer peripheral surface 5 A of the rotating drum 5, and the rotating drum 5 rotates in this state. In the present embodiment, the angular velocity of the rotating member is set such that the rotational peripheral velocity of the horn opposing surface 8 a matches the supply velocity of the continuous web 30. Therefore, on the outer peripheral surface 5A of the rotary drum 5, the horn opposing surface 8a of the ultrasonic horn 8 and the continuous web 30 rotate together without slipping. Thus, the continuous web 30 is conveyed by the rotation of the rotating member (rotary drum 5) in a state of being wound around the outer peripheral surface 5A of the rotating member (rotary drum 5).

  The arrangement pitch of the ultrasonic horns 8 in the circumferential direction projecting on the outer peripheral surface 5A of the rotary drum 5 is one of the arrangement pitch of the liquid absorbers 33 of the continuous web 30 and the arrangement pitch of the leg holes 34 shown in the lower part of FIG. I do. Therefore, when the continuous web 30 is conveyed to the outer peripheral surface 5A of the rotary drum 5, as shown in FIG. 2, the liquid absorber 33 is positioned between the ultrasonic horn 8 and the ultrasonic horn 8 adjacent to each other. On the horn facing surface 8a of the ultrasonic horn 8, a portion where the liquid absorber 33 is not present is installed.

  While the rotary base 6 and the rotary drum 5 rotate counterclockwise, the follower 56 b provided on the rocking drive moves along the cam groove 61 of the cam member 60 provided on the fixed table 4.

  As shown in FIGS. 6 and 9, when the seal unit 10 (the anvil 14 and the ultrasonic horn 8) moves between the predetermined angular position A0 and the predetermined angular position A1 by the rotation of the rotary base 6, the cam By the groove 61, the follower 56b is moved in a direction approaching the rotation center line OO. Therefore, during this time, as shown in the lower seal unit 10 in FIG. 4, the swing support member 50 is pivoted outward in the radial direction about the swing shaft 51 A, and the swing support member 50 The anvil 14 being held is directed outwardly at an angle of approximately 90 degrees with respect to the center of rotation line O-O.

  While the seal unit 10 (the anvil 14 and the ultrasonic horn 8) moves from the angular position A1 to a predetermined angular position A2 (corresponding to a predetermined first angular position), the follower 56b is guided by the cam groove 61 and moves outward It is moved. Therefore, the swing support member 50 is rotated toward the outer peripheral surface 5A of the rotary drum 5, and when reaching the angular position A2, the anvil 14 and the ultrasonic horn 8 clamp the continuous web 30. That is, when the ultrasonic horn 8 and the anvil 14 rotate with the rotation of the rotation member and reach the angular position A2, the anvil 14 abuts on the ultrasonic horn 8 to hold the continuous web (in the holding step) Equivalent).

  And as shown in FIG. 2, in the area | region in which the liquid absorber 33 of the continuous web 30 is not provided, the 1st sheet | seat 32, the 2nd sheet | seat 31, the 1st waistband 35, the 2nd waist shown in FIG. The laminate of the band 36, the first leg band 37 and the second leg band 38 is pressed by the horn facing surface 8 a of the ultrasonic horn 8 and the anvil facing surface 14 a of the anvil 14. At this time, the horn facing surface 8a and the anvil facing surface 14a are both flat surfaces, and the flat surfaces sandwich the continuous web 30 with each other. That is, in the sandwiching process, the flat surface of the ultrasonic horn 8 and the flat surface of the anvil 14 sandwich the continuous web 30. In the holding step, the continuous web 30 is held in a state where the ultrasonic horn 8 is not vibrating.

  As shown in FIG. 9, when the seal unit 10 (the anvil 14 and the ultrasonic horn 8) reaches a predetermined angular position C1 on the way from the angular position A1 to the angular position A2, the ultrasonic horn 8 is continuous. The state of separation from the web 30 is shifted to the state of contact with the continuous web 30.

  Then, the holding state continues until reaching the predetermined angular position A3 (corresponding to the predetermined second angular position), and during this time (that is, the continuous web 30 from the angular position A2 to the angular position A3 is the anvil 14 and the ultrasonic horn The seal portion S is formed while being held between the two. That is, in the ultrasonic sealing process for forming the sealing portion S, the ultrasonic horn 8 and the anvil 14 sandwich the continuous web 30, and the ultrasonic horn 8 vibrates in response to the ultrasonic wave emitted by the ultrasonic generator 9. The seal portion S is formed on the continuous web 30, and the process of releasing the sandwiching of the continuous web 30 is performed, which is performed between the angular position A2 and the angular position A3.

  When the seal unit 10 (the anvil 14 and the ultrasonic horn 8) reaches a predetermined angular position B1 (corresponding to a predetermined third angular position), the ultrasonic generator 9 starts emitting ultrasonic waves to the ultrasonic horn 8. That is, the ultrasonic wave generator 9 generates an ultrasonic wave when the ultrasonic horn 8 and the anvil 14 rotate in accordance with the rotation of the rotary member and reach the angular position B1. In the present embodiment, the angular position of the seal unit 10 can be detected by the encoder, and the fact that the seal unit 10 (the anvil 14 and the ultrasonic horn 8) has reached the angular position B1 is an ultrasonic wave generator. 9 is notified by an electric signal. The ultrasonic horn 8 receiving the ultrasonic wave from the ultrasonic wave generator 9 vibrates to form the seal portion S on the continuous web 30 (corresponding to the seal portion forming step).

  Then, when the energy of the ultrasonic vibration (corresponding to the electric energy of the ultrasonic generator 9) reaches a predetermined amount after the ultrasonic generator 9 emits ultrasonic waves, the ultrasonic generator 9 generates the ultrasonic waves. To stop the generation of ultrasound. That is, in the sealing portion forming step, when the energy of the ultrasonic vibration reaches a predetermined amount after the ultrasonic wave generator 9 generates the ultrasonic wave, the ultrasonic wave generator 9 stops the generation of the ultrasonic wave. The predetermined amount is determined in advance in consideration of the proper formation of the seal portion S. Further, a predetermined amount is determined so that the ultrasonic wave is stopped before the seal unit 10 (the anvil 14 and the ultrasonic horn 8) reaches the angular position A3 (in the present embodiment, as shown in FIG. 9). As shown, at angular position B2, the ultrasound generator 9 has stopped the ultrasound).

  When the seal unit 10 (the anvil 14 and the ultrasonic horn 8) reaches the angular position A3, the anvil 14 and the ultrasonic horn 8 release the holding of the continuous web 30. That is, when the ultrasonic horn 8 and the anvil 14 reach the angular position A3, the anvil 14 is separated from the ultrasonic horn 8 to release the holding (corresponding to the holding releasing step). Then, while the seal unit 10 (the anvil 14 and the ultrasonic horn 8) reaches from the angular position A3 to the angular position A0, the follower 56b is guided by the cam groove 61 toward the rotation center line OO, and the anvil 14 is an ultrasonic wave. It is pivoted away from the horn 8 and the continuous web 30. Then, when the angular position A0 is reached, as shown in the seal unit 10 in the lower part of FIG. 4 again, the anvil 14 turns to an angle of approximately 90 degrees with respect to the rotation center line OO and becomes the retracted position.

  As shown in FIG. 9, when the seal unit 10 (the anvil 14 and the ultrasonic horn 8) reaches a predetermined angular position C2 on the way from the angular position A3 to the angular position A0, the ultrasonic horn 8 is continuous. The contact state in contact with the web 30 is shifted to the separated state separated from the continuous web 30. The continuous web 30 separated from the ultrasonic horn 8 is conveyed to the outside of the sealing device 1 by the discharge conveyance roll 22 and cut along a cutting line C-C shown in the lower part of FIG. 1 to produce individual pant diapers. Ru.

<About the operation timing of the frequency adjustment (tuning) function>
It has already been mentioned that the ultrasonic generator 9 is provided with a frequency adjustment (tuning) function, but such frequency adjustment is carried out during operation of the sealing device 1. The timing at which the frequency adjustment is performed is indicated by the angular position BT in FIG.

  That is, after the ultrasonic horn 8 and the anvil 14 release the holding of the continuous web 30 in the ultrasonic sealing process (angular position A3), the ultrasonic generator 9 is used in the next ultrasonic sealing process by the ultrasonic horn 8. The frequency of the ultrasonic wave generated by the ultrasonic wave generator 9 is adjusted (frequency adjustment) until the ultrasonic wave generator 8 starts generating the ultrasonic wave to the ultrasonic wave horn 8 (angular position B1) Execute the process).

  In the present embodiment, when the seal unit 10 (the anvil 14 and the ultrasonic horn 8) is rotated by the rotating member as it rotates and reaches the predetermined angular position BT on the way from the angular position A3 to the angular position B1. The frequency adjustment process is to be implemented. That is, when the ultrasonic horn 8 and the anvil 14 reach the predetermined angular position, the frequency adjustment process is performed. In the present embodiment, the ultrasonic generator 9 is notified by an electrical signal that the seal unit 10 (the anvil 14 and the ultrasonic horn 8) has reached the angular position BT, and the ultrasonic generator 9 is notified of such notification. Adjusts the frequency of ultrasonic waves emitted to the ultrasonic horn 8.

<Repeat Operation of Seal Unit 10>
In the above, the operation (from the angular position A0 to the angular position A0 again) while the seal unit 10 makes one rotation of the rotary member has been described, but here the rotary member rotates continuously to form one seal unit 10 Among the operations repeated by repeatedly reaching the same angular position (hereinafter described by taking the seal unit S1 as an example), the repeated operation of the ultrasonic sealing process will be described.

  When the seal units S1 (the ultrasonic horn 8 and the anvil 14) reach the respective angular positions in the order of the angular positions A2, B1, B2 and A3, the sealing unit S1 performs an operation according to the respective angular positions and performs ultrasonic sealing processing Do. Then, when the rotary member makes one rotation and the seal unit S1 reaches the angular positions A2, B1, B2 and A3 again in the same order, the seal unit S1 performs an operation according to the same angular position again, and the ultrasonic seal is performed. Execute the process That is, the sealing unit S1 executes the ultrasonic sealing process at one interval per one rotation of the rotating member, and repeatedly executes the same according to the rotation of the rotating member.

<<< Relationship between the vibration of ultrasonic horn 8 and the operation of pinching >>>
Next, the relationship between the start and stop of the vibration of the ultrasonic horn 8 according to the present embodiment and the operation from when the ultrasonic horn 8 and the anvil 14 hold the continuous web 30 until when it is released will be illustrated in FIG. This will be described in detail using 10. FIG. 10 is an image diagram showing the relationship between the vibration section of the ultrasonic horn 8 involved in the ultrasonic sealing process and the holding section of the continuous web 30. As shown in FIG. The horizontal axis represents time (msec = one thousandth of a second), and shows changes in the state with time of each item of “continuous web pinching”, “ultrasonic horn”, and “power”.

  At the top of FIG. 10, a section from the ultrasonic horn 8 and the anvil 14 to holding the continuous web 30 until release is performed as “continuous web holding”. That is, the section from the angular position A2 to the angular position A3 is shown.

  Under “Continuous web pinching” in FIG. 10, as an “ultrasonic horn”, a waveform that vibrates a section from when the ultrasonic horn 8 starts vibrating until it stops is shown by the magnitude of amplitude. That is, when the angular position B1 is reached, the ultrasonic horn 8 starts to vibrate in response to the ultrasonic wave generated by the ultrasonic generator 9, and the amplitude of the vibration starts from the stationary state where there is no vibration amplitude. After the increase section of the amplitude), a predetermined amplitude (100% amplitude shown in FIG. 10) is reached. Then, the ultrasonic horn 8 vibrates at a predetermined amplitude until reaching the angular position B2.

  Then, the ultrasonic wave generator 9 stops the ultrasonic wave at the angular position B2, but the stop is to turn off the switch of the so-called ultrasonic wave generator 9, and the ultrasonic wave generated by the ultrasonic wave generator 9 is electrically It is only in the cut-off state when the circuit is turned on and off. That is, the supply of the ultrasonic waves generated by the ultrasonic wave generator 9 as the drive source is merely stopped for the ultrasonic horn 8. Therefore, mechanical vibration remains in the ultrasonic horn 8 which is a physical resonator (residual vibration).

  In order to stop the mechanical vibration of the ultrasonic horn 8, in addition to stopping the supply of the ultrasonic wave from the drive source, from the state of mechanically vibrating at a predetermined amplitude to the state of rest without amplitude It is necessary to suppress the vibration. That is, it is necessary to have a means for achieving a stationary state where there is no amplitude from a predetermined amplitude, and a time for the means to achieve a stationary state. For example, in the case where the vibration is naturally stopped (by damped vibration) by leaving it in the air, a resisting force such as air resistance or frictional force is used as a means, and it takes time until it becomes stationary. .

  Therefore, even if the ultrasonic generator 9 stops the ultrasonic waves, mechanical vibration remains in the ultrasonic horn 8 as residual vibration. That is, as shown in FIG. 10, the vibration section of the ultrasonic horn 8 is a section from the angular position B1 to the position beyond the angular position B2 until the residual vibration stops.

  Under the “ultrasonic horn” in FIG. 10, “power” indicates the fluctuation of the power (corresponding to the power (watt)) from when the ultrasonic generator 9 starts emitting the ultrasonic wave until the emitting is completed. In the present embodiment, when the energy of ultrasonic vibration (corresponding to the amount of electric power (watt hour)) reaches a predetermined amount after the ultrasonic generator 9 generates ultrasonic waves, the ultrasonic generator 9 generates Stop the generation of ultrasound. That is, after the ultrasonic wave generator 9 generates an ultrasonic wave at the angular position B1, the ultrasonic wave generator 9 transmits the ultrasonic wave at an angular position B2 at which the integrated value (ultrasonic vibration energy) of the power graph reaches a predetermined value. Stop.

  Next, with the vibration section of the ultrasonic horn 8 and the sandwiching section of the continuous web 30 shown in FIG. 10 as one continuous section, the section is divided (described under the outside of the graph frame in FIG. 10). The ultrasonic sealing process according to the present embodiment will be described using each section.

  First, a section from the angular position A2 to the angular position B1 is a section from when the ultrasonic horn 8 and the anvil 14 sandwich the continuous web 30 to when the vibration of the ultrasonic horn 8 is started. This section is referred to as a section D1 before the start of vibration.

  Next, from the angular position B1 to the angular position B2, the section in which the ultrasonic horn 8 which has started to vibrate continues the vibration upon receiving the ultrasonic electric signal emitted from the ultrasonic generator 9. This section is referred to as an electrical vibration section D2.

  Then, as described above, when the ultrasonic horn 8 reaches the angular position B2, the ultrasonic generator 9 stops the ultrasonic wave, and mechanical vibration remains as residual vibration in the ultrasonic horn 8 after the stop. Then, the residual vibration is stopped with a time difference from the stop of the ultrasonic wave. That is, from the angular position B2 until the residual vibration stops, it is a section in which the ultrasonic horn 8 is mechanically vibrating without a drive source. This section is referred to as a residual vibration section D3.

  Finally, the ultrasonic horn 8 is not vibrating between the residual vibration stop and the angular position A3 at which the continuous web 30 is released from the clamping. This section is referred to as a post-vibration stop section D4.

  That is, the ultrasonic sealing process according to the present embodiment can be divided into four sections of the section D1 before the start of vibration to the section D4 after vibration stop.

  Here, division is performed in the same manner as the above division with respect to general ultrasonic sealing processing. The ultrasonic sealing process according to the present embodiment is described by describing the difference between the section of the general ultrasonic sealing process divided into sections and the section of the ultrasonic sealing process according to the present embodiment. Do. In a general ultrasonic sealing process, a continuous web is obtained by the ultrasonic horn 8 vibrating in response to the ultrasonic wave generated by the ultrasonic generator 9 and the holding step in which the ultrasonic horn 8 and the anvil 14 hold the continuous web 30. A seal portion forming step of forming the seal portion S at 30 and a pinch releasing step of releasing the pinching of the continuous web 30 are included. That is, a general ultrasonic sealing process is a process from the ultrasonic horn 8 and the anvil 14 sandwiching the continuous web 30 to the formation of the sealing portion S and releasing the sandwiching.

  First, a process from the ultrasonic horn 8 and the anvil 14 sandwiching the continuous web 30 to the formation of the seal portion S is defined as one section. The section corresponds to the section D1 before the start of vibration and the electrical vibration section D2 according to the present embodiment.

  And processing after releasing formation of seal part S until release of pinching of continuous web 30 is made into one section. Then, there is no section in the one section that matches the section according to the present embodiment.

  In this embodiment, there is a section combining the residual vibration section D3 and the post-vibration stop section D4 instead of the one section, but in these sections, the residual vibration is stopped and then the continuous web 30 is held. Since the process to cancel is performed, it does not coincide with the one section. In other words, in the process of the one section, the process of releasing the holding of the continuous web 30 is executed before the residual vibration stops (or while the ultrasonic vibration continues). That is, unlike the general ultrasonic sealing process, the ultrasonic sealing process according to the present embodiment is provided with a section until the residual vibration of the ultrasonic horn 8 stops after the formation of the sealing portion S. A section is provided until the clamping of the continuous web 30 is released after the residual vibration has stopped.

  That is, in the ultrasonic sealing process according to the present embodiment, the ultrasonic horn 8 receives the ultrasonic wave generated by the ultrasonic generator 9 and the holding process in which the ultrasonic horn 8 and the anvil 14 hold the continuous web 30. Vibration causes the seal portion forming step of forming the seal portion S on the continuous web 30, and after the residual vibration remaining in the ultrasonic horn 8 is stopped after the ultrasonic generator 9 stops generating the ultrasonic wave, And n) releasing the nipping of the continuous web 30.

  Next, the relationship between the post-vibration stop section D4 sectioned before and the lengths (time lengths) of the sections before the start of vibration D1 to the residual vibration section D3 will be described. The length of each section shown in FIG. 10 represents an approximate length of time as an image.

  When the lengths of the section after vibration stop D4 and the section before vibration start D1 are compared, the ultrasonic sealing process is performed so that the section D4 after vibration stop is longer than the section D1 before vibration start. That is, the time from when the residual vibration stops to when the holding of the continuous web 30 is released is from when the ultrasonic horn 8 and the anvil 14 hold the continuous web 30 to when the ultrasonic generator 9 generates ultrasonic waves. Longer than time. In the present embodiment, the section D4 after vibration stoppage is about 40 to 50 mSec, and the section D1 before vibration start is about 30 mSec.

  Comparing the lengths of the post-vibration stop section D4 and the electrical vibration section D2, in the present embodiment, the ultrasonic seal processing is performed so that the post-vibration stop section D4 is shorter than the electrical vibration section D2. It is done. That is, the time from when the residual vibration stops to when the holding of the continuous web 30 is released is shorter than the time from when the ultrasonic generator 9 generates ultrasonic waves to when it stops. In the present embodiment, the section D4 after vibration stoppage is about 40 to 50 mSec, and the electric vibration section D2 is about 85 to 90 mSec.

  Comparing the lengths of the post-vibration stop section D4 and the residual vibration section D3, in the present embodiment, the ultrasonic seal processing is performed such that the post-vibration stop section D4 is longer than the remaining vibration section D3. ing. That is, the time from the stop of the residual vibration to the release of the holding of the continuous web 30 is longer than the time from the stop of the generation of the ultrasonic wave by the ultrasonic generator 9 to the stop of the residual vibration. In the present embodiment, the section D4 after vibration stoppage is about 40 to 50 mSec, and the residual vibration section D3 is about 30 mSec.

<<< Relationship between rotational speed and operation of rotating member >>>
Next, the relationship between the rotational speed of the rotary member (rotary drum 5) and the operation thereof will be described in detail. First, the rotational speed of the rotating member and the timing at which the ultrasonic generator 9 starts emitting ultrasonic waves will be described. As described above, in the present embodiment, the ultrasonic wave generator 9 generates an ultrasonic wave when the ultrasonic horn 8 and the anvil 14 rotate as the rotation member rotates and reach the angular position B1. That is, regardless of the rotational speed of the rotating member, when the seal unit 10 reaches the predetermined angular position B1, the ultrasonic generator 9 starts to emit ultrasonic waves.

  Next, how the vibration of the ultrasonic horn 8 and the holding operation change due to the rotational speed of the rotating member will be described focusing on the change in the length of the section (length of time) described above. The rotational speed of the rotating member according to the embodiment will be described.

  As described above, the angular positions A2, A3 and B1 are predetermined angular positions (first to third angular positions). Therefore, in the section between these angular positions, the length of the section shown in FIG. 10 changes due to the rotational speed of the rotating member.

  That is, the angle between the angular position A2 and the angular position A3, the angle between the angular position A2 and the angular position B1, and the angle between the angular position B1 and the angular position A3 are at predetermined angles. Because there are some, the time to pass through them becomes shorter as the rotational speed (angular velocity) is larger (faster). That is, the length of the section of D1 + D2 + D3 + D4, the length of the section of D1, and the length of the section of D2 + D3 + D4 become shorter as the rotational speed of the rotary member increases.

  On the other hand, since the length of the section of the electrical vibration section D2 is the time until the energy of the ultrasonic vibration emitted by the ultrasonic generator 9 reaches a predetermined amount, no change occurs due to the rotational speed of the rotating member . As described above, in the present embodiment, it is a time of about 85 to 90 mSec of the electrical vibration section D2 (note that this length (time) has such variation from experience, though there is some variation). I know).

  Further, since the length of the section of the residual vibration section D3 is a length until the vibration is settled, no change occurs due to the rotational speed of the rotating member as in the case of the electrical vibration section D2. That is, as described above, the length (time) of the residual vibration section D3 is about 30 mSec (this length (time) may be such a time from experience, though there is some variation) I know).

  In the present embodiment, the continuous web 30 is conveyed by rotating the rotating member at the following rotational speed (angular velocity).

  The difference between the third angle (angular position B1) and the second angle (angular position A3) is the post-oscillation holding angle θ (angles B1 to A3), and the ultrasonic generator 9 generates an ultrasonic wave and then residual vibration is generated. The rotation member is rotated at an angular velocity equal to or less than the post-vibration pinching angle θ / vibration time T when the time until stopping is the vibration time T (the time obtained by adding the electrical vibration section D2 and the residual vibration section D3) Transport the web. In the present embodiment, since the post-vibration pinching angle θ is about 110 degrees and the vibration time T is about 120 mSec, the rotational speed (angular velocity) of the rotating member is about 0.9 degrees / mSec (about 150 rpm) or less The rotation speed of

  Next, using two different operation modes (a low speed mode and a high speed mode) as the conveyance speed of the continuous web 30 (corresponding to the rotational speed of the rotating member (rotational peripheral speed)), the length of the section according to the difference in the operation mode Explain the change of

  These two operation modes are used to switch the transport speed (feed speed) of the continuous web 30. That is, it is used to switch the processing speed of the ultrasonic sealing process, and is mainly used to adjust the number of ultrasonic sealing processes. In the present embodiment, the low speed mode is used as the first speed mode, and the high speed mode is used as the second speed mode larger than the first speed.

  As described above, the length of the section D2 + D3 + D4 is shorter as the transport speed of the continuous web 30 is faster, so the high speed mode is shorter than the low speed mode. And since the length of the section of electric vibration section D2 and residual vibration section D3 does not depend on the conveyance speed of continuous web 30, it is the same in low speed mode and high speed mode. Therefore, among the sections from the electrical vibration section D2 to the post-vibration stop section D4, a difference occurs between the low speed mode and the high speed mode only in the post-vibration stop section D4.

  That is, when the plurality of seal portions S are formed in the low speed mode in which the continuous web 30 is conveyed by rotating the rotating member at the first speed, the rotating member is rotated at the second speed larger than the first speed. The time from when the residual vibration stops to when the holding of the continuous web 30 is released is longer than when the plurality of seal portions S are formed in the high speed mode in which the continuous web 30 is conveyed. The length (time) of the post-vibration stop section D4 differs depending on the transport speed of the continuous web 30 (rotational speed of the rotating member), and the low speed mode is longer than the high speed mode.

<<< About the effectiveness of the ultrasonic sealing method according to the present embodiment >>>
As described above, in the ultrasonic sealing method according to the present embodiment, the ultrasonic sealing process includes the pinching step in which the ultrasonic horn 8 and the anvil 14 pinch the continuous web 30, and the ultrasonic wave generated by the ultrasonic wave generator 9. The ultrasonic horn 8 is vibrated by receiving the sound wave, and the seal portion forming step of forming the seal portion S on the continuous web 30 and the ultrasonic generator 9 stop the generation of the ultrasonic wave and remain in the ultrasonic horn 8 After the residual vibration has stopped, the clamping release step of releasing the clamping of the continuous web 30 is provided. Therefore, it is possible to rapidly converge the residual vibration of the ultrasonic horn 8.

  In the conventional example, when deciding the timing for releasing the holding of the continuous web 30, the presence of residual vibration as noise was not considered at all. Therefore, the cancellation is performed in a state where the residual vibration remains after the ultrasonic generator 9 stops the generation of the ultrasonic wave.

  And since residual vibration is more difficult to be settled in the case where the holding is not made (released) than when the holding by the ultrasonic horn 8 and the anvil 14 is made, the residual vibration is made after the release. There was an event that continued without getting settled.

  On the other hand, in the ultrasonic sealing process according to the present embodiment, after the ultrasonic generator 9 stops the generation of the ultrasonic wave and the residual vibration remaining in the ultrasonic horn 8 stops, It was decided to release the pinch. That is, after the residual vibration converges, the clamping is released, and the clamping state in which the residual vibration is more likely to be settled is maintained until the residual vibration stops. Therefore, according to the present embodiment, it is possible to rapidly converge the residual vibration.

  Further, in the present embodiment, the time from when the residual vibration stops to when the holding of the continuous web 30 is released is the time from when the ultrasonic generator 9 stops the generation of ultrasonic waves until when the residual vibration stops. It was longer than that.

  That is, the post-vibration stop section D4 shown in FIG. 10 is longer than the residual vibration section D3. In this way, it is possible to allow time for the residual vibration to stop before releasing the holding of the continuous web 30, and even if the length (time) of the residual vibration section D3 varies. It is possible to reliably carry out the release of the clamping after the residual vibration converges.

  In the present embodiment, the ultrasonic horn 8 and the anvil 14 sandwich the continuous web 30 after the residual vibration stops and the time to release the sandwich of the continuous web 30 is the ultrasonic generator 9. It was determined to be longer than the time to generate ultrasonic waves.

  That is, the section D4 after vibration stop shown in FIG. 10 is longer than the section D1 before the start of vibration. In the section D1 before the start of vibration, the order in which the vibration of the ultrasonic horn 8 starts after holding the continuous web 30 is important, and the length (time) of the section may be short. On the other hand, if the section D4 after vibration stoppage is lengthened, it is possible to allow a time from the residual vibration stop to the release of the holding of the continuous web 30, and the length of the residual vibration section D3 (time Even if there is a variation, it is possible to reliably carry out the release of the clamping after the residual vibration converges.

  Further, in the holding process according to the present embodiment, the continuous web 30 is held in a state in which the ultrasonic horn 8 is not vibrating.

  Therefore, it becomes possible to hold the continuous web 30 in a state in which the ultrasonic horn 8 is not vibrating. That is, it becomes possible to suppress careless vibration and it is possible to vibrate the ultrasonic horn 8 promptly.

  Further, in the holding process according to the present embodiment, the flat surface of the ultrasonic horn 8 and the flat surface of the anvil 14 hold the continuous web 30.

  That is, by sandwiching the flat surfaces of the horn facing surface 8a and the anvil facing surface 14a to each other, the residual vibration of the ultrasonic horn 8 can be rapidly converged.

  In the present embodiment, the ultrasonic wave generator 9 generates ultrasonic waves when the ultrasonic horn 8 and the anvil 14 are rotated with the rotation of the rotary member to reach the angular position B1.

  Therefore, the ultrasonic wave generator 9 generates an ultrasonic wave when the ultrasonic horn 8 and the anvil 14 reach the predetermined angular position B1 regardless of whether the rotation of the rotation member is fast or slow. Become. Therefore, it becomes possible to generate an ultrasonic wave reliably at a desired timing (for example, in the holding state after holding at the angular position A2) regardless of the rotational speed of the rotating member.

  Further, in the present embodiment, when the difference between the third angle and the second angle is θ, and the time from when the ultrasonic generator 9 generates an ultrasonic wave to when the residual vibration stops is T, the rotation is The continuous web is conveyed by rotating the member at an angular velocity of θ / T or less.

  Assuming that the angular velocity (rotational velocity) of the rotating member is A, the relationship of θ / T ≧ A is obtained, and by multiplying both sides by T, the relationship of θ ≧ A × T is established. In other words, “the angle (degree) at which the rotary member rotates and advances during the vibration time T” which is the value of the angular velocity A (degree / second) × the vibration time T (second) of the rotary member Less than). In other words, after the ultrasonic horn 8 starts to vibrate (from the third angular position), the sandwiching of the continuous web 30 is not released before the vibration time T elapses (does not reach to the second angular position) . That is, since the holding of the continuous web 30 is released (after reaching the second angular position) after the vibration (residual vibration) of the ultrasonic horn 8 stops (after the vibration time T elapses), the ultrasonic wave is generated. It is possible to quickly converge the residual vibration of the horn 8.

  Further, in the present embodiment, when the plurality of seal portions S are formed in the low speed mode in which the continuous web 30 is transported by rotating the rotating member at the first speed, the rotating member is larger than the first speed. The time from when the residual vibration stops to when the continuous web 30 is released is longer than when the multiple seal portions S are formed in the high speed mode in which the continuous web 30 is conveyed by rotating at the second speed. And

  Therefore, by selecting the operation mode (selecting the transport speed of the continuous web 30), it is possible to adjust the time (that is, the margin) until the clamping is released after the residual vibration stops.

  Further, in the present embodiment, the anvil 14 comes in contact with and separates from the ultrasonic horn 8 by swinging.

  Therefore, contact / separation can be realized only by providing a mechanism for swinging the anvil 14, that is, a reliable holding mechanism can be realized with a simple structure.

  Also, after the ultrasonic horn 8 and the anvil 14 release the holding of the continuous web 30 in the ultrasonic sealing process according to the present embodiment, the ultrasonic generator 9 is used in the next ultrasonic sealing process by the ultrasonic horn 8. It is decided to execute a frequency adjustment process for adjusting the frequency of the ultrasonic wave generated by the ultrasonic wave generator 9 to the ultrasonic wave horn 8 until it starts generating the ultrasonic wave to the ultrasonic wave horn 8 .

  Therefore, the frequency adjustment process is performed in the state where the residual vibration has stopped. Therefore, it is possible to adjust the frequency appropriately.

=== Other Embodiments ===
The above embodiments are for the purpose of facilitating the understanding of the present invention, and are not for the purpose of limiting the present invention. It goes without saying that the present invention can be modified and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

  Further, in the above embodiment, the ultrasonic wave generators 9 that emit ultrasonic waves to each of the plurality of seal units 10 are different from each other. That is, although the ultrasonic wave generator 9 is arranged in each of the seal units 10 one by one, it is not limited to this. For example, instead of arranging one ultrasonic wave generator 9 in one-to-one correspondence with one seal unit 10, it is possible to arrange one ultrasonic wave generator 9 in correspondence with a plurality of seal units 10. Good.

  When one ultrasonic wave generator 9 is provided for each seal unit 10, one ultrasonic wave generator 9 does not have to emit ultrasonic waves to a plurality of seal units 10. That is, it is not necessary to perform reading and writing switching of the memory (every time the corresponding seal unit 10 is changed) each time the ultrasonic wave generator 9 corresponds to each of the plurality of seal units 10. In addition, since the ultrasonic generator 9 only needs to generate ultrasonic waves for one seal unit 10 without requiring time for the read / write switching, the above-mentioned operation mode is a high speed mode. Even ultrasonic generation can be performed without problems (with a margin). From this point of view, the above embodiment is preferable.

  In the above embodiment, when the ultrasonic sealing process for forming the sealing portion S is performed, the energy (electric energy) of the ultrasonic vibration is set to a predetermined amount after the ultrasonic generator 9 generates the ultrasonic wave. When reached, the ultrasonic generator 9 decides to stop the ultrasonic wave, but this is not restrictive. For example, after a predetermined time has elapsed since the ultrasonic generator 9 emits ultrasonic waves, or after the ultrasonic generator 9 emits ultrasonic waves, the instantaneous value of the energy of ultrasonic vibration (equivalent to the power of the ultrasonic generator 9) The ultrasonic wave may be stopped when the predetermined threshold is exceeded.

  In the above embodiment, a plurality of members of ultrasonic horn 8 and anvil 14 are provided at equal intervals on outer peripheral surface 5A, and the other members correspond to the respective members. A plurality of the members are provided on the rotating member so as to be capable of coming into and coming out of contact with the one member with the continuous web interposed therebetween. One member is the ultrasonic horn 8 and the other member is the anvil 14. However, it is not limited to this. One member may be the anvil 14 and the other member may be the ultrasonic horn 8.

  Moreover, in said embodiment, although the six seal | sticker units 10 were provided in the seal | sticker apparatus 1, it does not restrict to this. The number of seal units 10 provided in the seal device 1 may be seven or more or five or less.

  Moreover, although the link mechanism which used the cam was used as a rocking drive part which concerns on said embodiment, it does not restrict to this. The operations of the ultrasonic horn 8 and the anvil 14 according to the above embodiment may be realized by using a cylinder mechanism or the like instead of the link mechanism using a cam.

  Moreover, in said embodiment, although the air damper was used for the 1st elastic member 71 and the 2nd elastic member 72, it does not restrict to this. A coil spring or the like may be used instead of the air damper.

DESCRIPTION OF SYMBOLS 1 seal device, 2 timing wheel, 3 bearing portion, 3a rotary shaft 3b ball bearing, 4 fixed table, 5 rotary drum, 5A outer peripheral surface 5a rotary drum window, 6 rotary base, 7a converter, 7b booster 8 ultrasonic horn, DESCRIPTION OF SYMBOLS 8a Horn opposing surface, 9 ultrasonic wave generator, 10 seal unit 14 anvil, 14B anvil convex part, 14a anvil opposing surface 21 supply conveyance roll, 22 discharge conveyance roll, 30 continuous web 30A continuous web one side, 30B continuous web 31 second sheet 32 first sheet 32a first sheet side edge 32b first sheet second side edge 33 liquid absorbent 34 leg holes 35 first waist band 36 second waist band 37 first leg band 38 second leg band 50 rocking support member Reference Signs List 51 rocking portion 51A rocking shaft 51B first connecting shaft 52 holding portion 52B mounting surface 52a frame portion 52c inner surface 53 drive link 54 rotation link 54A rotation link base 54B rotation link arm , 54a support shaft, 55 second connection shaft, 56 drive member 56a drive support, 56b follower, 60 cam member, 61 cam groove 70 support portion, 71 first elastic member, 71A first fixing plate, 71B second fixing Plate 72 second elastic member, 73 first nozzle, 74 second nozzle, 75 first air pipe 76 second air pipe, S seal portion, D1 section before start of vibration, D2 electrical vibration section D3 residual vibration section, D4 vibration Section after stop

Claims (13)

An ultrasonic sealing method for forming a plurality of seal portions at intervals in the conveyance direction of the continuous web by repeatedly performing ultrasonic sealing processing on the continuous web related to the absorbent article to be conveyed,
The ultrasonic sealing process is
A pinching step in which an ultrasonic horn and an anvil pinch the continuous web;
A sealing portion forming step of forming the sealing portion on the continuous web by receiving ultrasonic waves generated by an ultrasonic generator and vibrating the ultrasonic horn;
A sandwiching release step of releasing the sandwiching of the continuous web after the ultrasonic generator stops the generation of ultrasonic waves and the residual vibration remaining in the ultrasonic horn stops;
An ultrasonic sealing method characterized by having. The ultrasonic sealing method according to claim 1, wherein
The time from when the residual vibration stops to when the holding of the continuous web is released is longer than the time from when the ultrasonic generator stops generating the ultrasonic wave until when the residual vibration stops. Ultrasonic sealing method. The ultrasonic sealing method according to claim 1 or 2, wherein
The time from when the residual vibration stops to when the holding of the continuous web is released is the time from when the ultrasonic horn and the anvil hold the continuous web until when the ultrasonic generator generates ultrasonic waves. Ultrasonic sealing method characterized by longer than. The ultrasonic sealing method according to any one of claims 1 to 3, wherein
Ultrasonic sealing method characterized in that the time from the stop of the residual vibration to the release of the holding of the continuous web is shorter than the time from the generation of ultrasonic waves to the stop of the ultrasonic wave generator. . The ultrasonic sealing method according to any one of claims 1 to 4, wherein
In the holding step, the continuous web is held while the ultrasonic horn is not vibrating. The ultrasonic sealing method according to any one of claims 1 to 5, wherein
In the sealing portion forming step, when the energy of the ultrasonic vibration reaches a predetermined amount after the ultrasonic generator generates the ultrasonic wave, the ultrasonic generator stops the generation of the ultrasonic wave. Characteristic ultrasonic sealing method. The ultrasonic sealing method according to any one of claims 1 to 6, wherein
The ultrasonic sealing method according to claim 1, wherein, in the holding step, the flat surface of the ultrasonic horn and the flat surface of the anvil hold the continuous web. The ultrasonic sealing method according to any one of claims 1 to 7, wherein
The continuous web is conveyed by rotation of the rotating member in a state of being wound around the outer peripheral surface of the rotating member,
A plurality of members of the ultrasonic horn and the anvil are provided at equal intervals on the outer peripheral surface,
A plurality of other members are provided on the rotating member corresponding to each one of the members, and are provided so as to be able to contact or separate the one member with the continuous web interposed therebetween,
When the ultrasonic horn and the anvil rotate with the rotation of the rotating member to reach a predetermined first angular position, the other member abuts on the one member to hold the continuous web. And when the ultrasonic horn and the anvil reach a predetermined second angular position, the other member separates from the one member to release the holding.
The ultrasonic sealing method characterized in that the ultrasonic wave generator generates ultrasonic waves when the ultrasonic horn and the anvil rotate with the rotation of the rotating member and reach a predetermined third angular position. . The ultrasonic sealing method according to claim 8, wherein
Assuming that the difference between the third angle and the second angle is θ, and the time from when the ultrasonic generator generates an ultrasonic wave to when the residual vibration stops is T,
The ultrasonic sealing method, wherein the continuous web is conveyed by rotating the rotating member at an angular velocity of θ / T or less. The ultrasonic sealing method according to claim 9, wherein
When the plurality of seals are formed in the low speed mode in which the rotating member is rotated at the first speed to convey the continuous web, the rotating member is rotated at the second speed higher than the first speed. An ultrasonic wave characterized in that the time from when the residual vibration is stopped to when the holding of the continuous web is released is longer than when the plurality of seal portions are formed in the high speed mode for carrying the continuous web. How to seal. The ultrasonic sealing method according to any one of claims 8 to 10, wherein
The ultrasonic sealing method characterized in that the other member is brought into contact with or separated from the one member by swinging. The ultrasonic sealing method according to any one of claims 1 to 11, wherein
After the ultrasonic horn and the anvil release the sandwiching of the continuous web in the ultrasonic sealing process, the ultrasonic generator superimposes on the ultrasonic horn in the next ultrasonic sealing process by the ultrasonic horn. An ultrasonic sealing method characterized in that a frequency adjustment process is performed to adjust the frequency of the ultrasonic wave generated by the ultrasonic wave generator to the ultrasonic horn until the generation of the sound wave is started. A conveying device for conveying the continuous web relating to the absorbent article;
An ultrasonic generator that generates ultrasonic waves,
An ultrasonic horn that forms a seal portion for the continuous web transported by the transport device by receiving and vibrating the ultrasonic wave generated by the ultrasonic generator;
An anvil for clamping the continuous web in cooperation with the ultrasonic horn;
The ultrasonic horn vibrates in a state of sandwiching the continuous web in cooperation with the anvil, and repeatedly performs an ultrasonic sealing process for forming the seal portion on the continuous web, thereby forming the continuous web An ultrasonic seal device that forms a plurality of the seal portions at intervals in the transport direction, the ultrasonic seal device comprising:
The ultrasonic horn and the anvil release the holding of the continuous web after the ultrasonic generator stops generating ultrasonic waves and residual vibration remaining in the ultrasonic horn stops. Ultrasonic sealing device.

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