JP2002254522A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sealing device which can efficiently form a transverse sealing part having enough seal strength. SOLUTION: The sealing device has a transverse sealing means 100 which seals films 1, which are laid to overlap each other and to be transferred in the longitudinal direction, in a direction crossing the longitudinal direction. The transverse sealing means 100 has the first sealing means 3 and the second sealing means 8 which hold the films 1 between them. The first sealing means 3 has an endless conveyance means 4 extended in the longitudinal direction of the films 1 and a plurality of sealing bars 5 supported at prescribed intervals in the extension direction by the conveyance means 4. The conveyance means 4 is moved so that the sealing bars 5 are moved in the moving direction of the films 1 at a speed equal to that of the films 1 while the films 1 are held between the sealing bars 5 and the second sealing means 8 to do transverse sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device provided with a horizontal sealing means for sealing a superposed film in a direction intersecting a longitudinal direction thereof.

[0002]

2. Description of the Related Art When a superposed film is sealed in a direction intersecting with the longitudinal direction using ultrasonic waves or the like (hereinafter referred to as a horizontal seal), for example, the sealing is performed by an operation shown in FIG. It is carried out. In the drawing, reference numeral 1 denotes a film to be sealed (side end faces along the longitudinal direction are shown in the drawing).
It is transported downward from above along its longitudinal direction.
A horn 2 is provided on the front and back (left and right in the figure)
a and an anvil 2b are provided so as to face each other with the film 1 interposed therebetween.

At the time of sealing, the horn 2a and the anvil 2b move toward the film 1 from the standby position indicated by reference numeral A in the figure, and hold the film 1 from the front and back as indicated by reference numeral B in the figure. The horn 2a and the anvil 2b move downward with the transfer of the film 1, and the horn 2a
By ultrasonic vibration applied toward the anvil 2b from
Portions of the film 1 sandwiched between the horn 2a and the anvil 2b are fused together, and the film 1 is horizontally sealed.

[0004] When the horn 2a and the anvil 2b move downward to a predetermined position (the position indicated by the symbol C in the figure), the horn 2a and the anvil 2b move as shown by the symbol D in the figure.
It moves away from the film 1, moves further upward, and returns to the standby position A. By repeating this process, the film 1 transferred from above to below is removed.
Are continuously horizontally sealed at a predetermined interval corresponding to the interval between the horn 2a and the anvil 2b. This operation is performed by the horn 2a and the anvil 2 as shown by arrows in the figure.
Since the movement trajectory of b has a rectangular shape, it is generally called “box motion”.

[0005]

By the way, in the case of the box motion, the horn 2a and the anvil 2b are moved from the position indicated by the symbol C in the drawing to the standby position A between the end of the horizontal seal and the start of the next horizontal seal. I need to put it back. However, if the holding time between the horn 2a and the anvil 2b (the time from the position indicated by the symbol B to the position indicated by the symbol C in the drawing) is increased in order to improve the sealing strength, the horn 2a and the anvil 2b are set to the symbol C in the drawing. The time required to return to the standby position A from the position indicated by 長 く becomes longer. Also, horn 2
When the holding time between the a and the anvil 2b is increased, the interval between the horizontal seal portions formed by the horizontal seals is naturally increased.

Therefore, conventionally, when the interval between the horizontal seals is short, it has been necessary to cope with the problem by shortening the holding time between the horn 2a and the anvil 2b and unavoidably lowering the seal strength. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a seal device capable of realizing both improvement in seal strength at the time of lateral sealing and shortening of a seal interval.

[0007]

According to the present invention, there is provided a sealing device comprising a transverse sealing means for sealing a superposed film conveyed along a longitudinal direction in a direction intersecting the longitudinal direction. Horizontal sealing means includes first sealing means and second sealing means for sandwiching the film from the front and back, and further, the first sealing means extends endlessly along the longitudinal direction of the film. And a plurality of seal bars supported at predetermined intervals along the direction of extension of the film, and the film is interposed between the seal bar and the second seal means. The horizontal seal is performed by moving the transport means so that the seal bar moves at a constant speed with the film along the transport direction of the film while nipping.

Here, the interval between the seal bars supported by the conveying means may be changeable. For example, between the adjacent seal bars, the endless member constituting the conveying means is moved inside a loop constituted by the conveying means, and by changing the amount of movement, the seal bar The interval can be changed.

[0009] Further, the second sealing means may be a horn extending parallel to the surface of the film along the longitudinal direction of the film and applying ultrasonic vibration to the film.

[0010] Alternatively, the second sealing means may be formed by a conveying means having an endless shape similar to the first sealing means, and a plurality of supporting means which are supported by the conveying means at predetermined intervals along the extending direction thereof. It may be a seal bar. In this case, while sandwiching the film between the seal bars of the first and second sealing means, the seal bars of the first and second sealing means are in contact with the film along the transport direction of the film. The horizontal sealing is performed by moving the transporting means of the first and second sealing means so as to move at a constant speed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show examples of the horizontal sealing means according to the sealing device of the present invention. Here, FIGS. 1, 3 and 4 are side views of the horizontal sealing means, and FIG. 2 is a cross-sectional view of the horizontal sealing means. In the drawing, reference numeral 1 denotes a film similar to that shown in FIG. 7, and the film 1 is transferred from above to below along the longitudinal direction in a state of being superposed.

Reference numeral 3 denotes first sealing means provided on one of the front and back sides of the film 1 (the right side in FIG. 1). The first sealing means 3 includes an endless chain (conveying means) 4 extending along the longitudinal direction of the film 1.
And a plurality of anvils (seal bars) 5 supported at predetermined intervals (equal intervals in the present embodiment) along the extending direction of the chain 4.

As shown in FIG. 2, the chain 4 is stretched between a pair of upper and lower pulleys 41 on both left and right sides of the film 1, respectively. The pulleys 41 can be moved up and down, respectively, and the distance between the pulleys 41 is located vertically above and below the horns (described later) that face each other across the film 1. It is set as follows.

A plurality of (eight in the present embodiment) a pair of left and right support members 6 are attached to the chain 4 at the above-mentioned predetermined intervals along the direction in which the chain 4 extends. The support member 6 is a pair of left and right plates 61 attached to the chain 4 from outside (hereinafter simply referred to as “outside”) of a loop formed by the chain 4, and rotatably extends between the plates 61. Shaft 62,
A rod 63 projecting outward from the shaft 62;
A bush 64 supported movably along its longitudinal direction, and a bush 64 attached to the tip of the rod 63.
And a flange 65 for preventing the rod from coming off from the rod 63.

As shown in FIG. 2, the anvil 5 is horizontally stretched and fixed between the bushes 64 of the support member 6 located on the left and right, so that the plurality of anvils 5 are fixed.
Is supported by the chain 4 via the support member 6. In FIG. 2, reference numeral 7 denotes a pair of left and right sprockets which are driven by the chain 4 to rotate and support the chain 4 from the outside. The sprocket 7 is rotated by a support frame 72 extending left and right via a shaft 71. It is freely supported.

Reference numeral 8 denotes a horn (second sealing means) provided on the other side (left side in FIG. 1) of the film 1 so as to face the first sealing means 3 with the film 1 interposed therebetween. It is. The horn 8 extends in a direction parallel to the surface of the film 1 along the longitudinal direction of the film 1 and is positioned so that the front end surface of the horn 8 contacts the surface of the film 1 from the other side. ing. The total length of the horn 8 (the length in the vertical direction shown in FIG. 1) is determined while holding the film 1 between the horn 8 and the anvil 5 as described later.
When the film 1 is moved at the same speed as the transfer speed and the horizontal sealing is performed, the film 1 is set to such an extent that a sufficient horizontal sealing can be performed. Specifically, the material and thickness of the film 1, the moving speed,
It is set according to the sealing performance of the horizontal sealing means, required sealing strength, and the like. Further, the width of the horn 8 (length in the left-right direction shown in FIG. 2) is set slightly larger than the width of the film 1 as shown in FIG.

Reference numeral 9 denotes a support plate provided between the film 1 and the chain 4 in parallel with the surface of the film 1.
The distance between the surface 1a of the support plate 9 facing the film 1 and the film 1 is the same as the height of the anvil 5 at the time of horizontal sealing (the distance in the horizontal direction in FIG. 1, and the vertical direction in FIG. 2). As a result, the base end surface (the lower surface in FIG. 2) of the anvil 5 movably supported by the bush 64 is moved to the surface 9a.
The anvil 5 is positioned at an appropriate position at the time of the horizontal sealing by being held in contact with the upper side. The upper and lower ends of the surface 9a are gradually chamfered toward the chain 4 in order to smoothly contact / remove the anvil 5.

Reference numeral 10 denotes an outer edge of the chain 4 (a position that does not overlap the support member 6) on the side of the support plate 9 on the side of the chain 4, and a space between the anvils 5 located above and below the edge (FIG. 1). A pair of right and left pushers for adjusting the middle symbol W). These pushers 10 can be moved to positions equidistant from both the anvils 5 located above and below them in conjunction with the direction approaching and separating from the film 1 (the left-right direction in FIG. 1, the up-down direction in FIG. 2). As described above, the slider 11 is movably supported by the slider 11 (see FIG. 2) extending in the approach / separation direction, and the slider 11 is further supported by a support 12 extending left and right. In addition, these pushers 10
As a result, the chain 4 has a bent portion 4a which is bent in a U-shape toward the inside of the loop formed by the chain 4 (hereinafter simply referred to as the inside).

The pusher 10 is moved to change the amount of pressure applied to the chain 4 and to adjust the degree of bending at the bent portion 4a.
The distance between the anvils 5 above and below (reference symbol W in FIG. 1) can be adjusted. In this embodiment, as shown in FIG. 1, two pushers 10 are provided between the three anvils 5 in order to adjust the interval W between the three upper and lower anvils 5. Pusher 1
It goes without saying that the 0s also move in conjunction with each other. The member extending from the first sealing means 3 to the support 12 constitutes a horizontal sealing means 100.

Next, the lateral sealing means 1 having the above configuration
The operation of 00 is described below. At the time of horizontal sealing, first, the position of the pusher 10 is adjusted, and the degree of bending of the bent portion 4a is adjusted so that the interval W between the anvils 5 located above and below the pusher 10 becomes a desired interval. Also,
The pulley 41 is moved up and down in accordance with the degree of bending of the bending portion 4a to remove unnecessary tension and looseness of the chain 4.

Next, the pulley 41 is rotationally driven in a direction indicated by an arrow R in FIG.
It is moved so as to move downward at a position facing the film 1. At this time, the anvil 5 located at the upper end of the chain 4 is guided on the surface 9a of the support plate 9 facing the film 1 side before the film 1 is clamped, and is positioned at an appropriate position during the horizontal sealing. , Move downward on the surface 9a.

In addition to the above operation, the film 1 is
At the same speed as the moving speed of the anvil 5, it is transferred downward as shown by the arrow M in FIG. 1 and introduced between the anvil 5 and the horn 8. The introduced film 1 is sandwiched between the distal end surface of the horn 8 and the distal end surface of the anvil 5 on the surface 9a, and is transported downward while sliding on the distal end surface of the horn 8 while maintaining this state. You. When ultrasonic vibration is applied from the horn 8 toward the anvil 5, the portions of the film 1 sandwiched between the horn 8 and the anvil 5 are fused together, and the film 1 is horizontally sealed while being transported downward. You.

As shown in FIGS. 3 and 4, when the anvil 5 passes through the bent portion 4a, the chain 4 and the supporting member 6 driven by the chain 4 move inward. On the other hand, the anvil 5 has a bush 6 movably supported by the rod 63.
4 and is held in contact with the surface 9a, the position of the anvil 5 does not change even if the support member 6 driven by the chain 4 moves inward. Therefore, regardless of the presence or absence of the bent portion 4a, the anvil 5 moves downward on the surface 9a in a state where the anvil 5 is always positioned at an appropriate position during the horizontal sealing. As a result, regardless of the presence or absence of the bent portion 4a, the film 1 is horizontally sealed while being sandwiched between the horn 8 and the anvil 5.

Since the chain 4 also moves inward and outward at the bent portion 4a, when the anvil 5 passes through the bent portion 4a, the moving speed of the anvil 5 downwardly decreases relatively. Accordingly, it is necessary to reduce the speed of the downward movement of the film 1 in synchronization with the passage of the anvil 5 to the bent portion 4a. Alternatively, the moving speed of the chain 4 may be increased in synchronization with the passage of the anvil 5 to the bent portion 4a so that the moving speed of the anvil 5 downward is constant. In this case, the film 1 is moved downward at a constant speed at the same speed as the downward moving speed of the anvil 5. When a plurality of bent portions 4a are formed as shown in FIGS. 3 and 4, in order to enable the speed change of the film 1 or the chain 4 as described above, FIG.
As shown in FIG. 4, it is necessary to set the positions of the anvil 5 and the pusher 10 in advance so that the passage timing of the anvil 5 with respect to each bent portion 4a is synchronized.

When the anvil 5 moves to the lower end of the horn 8, the film 1 moves downward and the anvil 5 moves.
Is separated from the film 1 by being guided by the pulley 41 on the lower end side. As a result, the film 1
Is released, and the horizontal seal ends. The anvil 5 wound by the lower pulley 41 moves upward together with the chain 4, is guided by the upper pulley 41, moves downward, and slides on the surface 9 a of the support plate 9 while moving upward. The film 1 transferred from the horn 8 is sandwiched between the film 1 and the upper end of the horn 8. By repeating the above operation,
The film 1 transferred from above to below is continuously horizontally sealed at an equal interval to the interval W of the anvil 5.

According to the horizontal sealing means 100, the plurality of anvils 5 supported by the chain 4 are sequentially fed out from the upper end of the chain 4 with the rotation of the chain 4 to perform horizontal sealing. It is possible to respond. Therefore, even if the entire length of the horn 8 is extended to improve the sealing strength and the clamping time between the chain 8 and the anvil 5 is increased, the seal interval is not affected. That is, according to the sealing device provided with the horizontal sealing means 100, it is possible to realize both improvement of the sealing strength at the time of the horizontal sealing and shortening of the sealing interval.

Further, a pusher 10 for pressing the chain 4 from the outside to form a bent portion 4a at a position facing the horn 8 and adjusting a distance W between the anvils 5 located above and below the chain 4 is formed.
Therefore, even when the individual anvil 5 is immovably supported by the chain 4, the position W of the pusher 10 in the bent portion 4a is changed to change the interval W between the anvils 5, and the sealing portion formed by the horizontal seal is formed. (Horizontal seal)
Can be changed. On the other hand, when it is not necessary to change the interval between the horizontal seal portions, the pusher 10 is unnecessary, and it is not necessary to change the speed of the film 1 or the chain 4 during the horizontal seal.

On the other hand, depending on the total length of the chain 4 and the installation interval of the anvil 5, the anvil 5 may not be installed at equal intervals over the entire area of the chain 4. In such a case, for example, as shown schematically in FIG. 5, a plurality of anvils 5 are wound around a part of the chain 4 at equal intervals W, and a new chain 4 ′ is installed so as to overlap the chain 4. A plurality of anvils 5 are stretched at equal intervals W over a part of the chain 4 '. (A) in FIG.
4 (b) shows the case where the chains 4 'are alternately stacked, and FIG.

The anvil 5 supported by the chain 4 'is located rearward (upward) in the transport direction of the anvil 5 supported by the chain 4, and the anvil 5 and the chain 4' located at the rearmost ends of the chain 4 are arranged. The position of the anvil 5 is adjusted so that the distance W ′ with the anvil 5 located at the forefront end coincides with the above-mentioned distance W. In the cases shown in FIGS. 5A and 5B, it goes without saying that the anvils 5 laid over the chains 4, 4 'can move independently without interfering with each other. .

When the film 1 is horizontally sealed using these chains 4 and 4 ', the state shown in FIG.
W '), the chains 4, 4' are rotated as shown by the arrow R in FIG. 6, and the seat 1 is moved at the same speed as the moving speed of the anvil 5, as shown by the arrow M in FIG. Transported downward. Then, ultrasonic vibration is applied from the horn 8 toward the anvil 5 while the film 1 sandwiched between the distal end surface of the horn 8 and the distal end surface of the anvil 5 is transferred downward. The portion sandwiched between the film and the anvil 5 is fused together, and the film 1
However, due to the anvil 5 supported by the chains 4 and 4 ',
Horizontal sealing is performed continuously at predetermined intervals W and W '.

An anvil 5 located at the end of the chain 4
When the chain 4 (shown by reference numeral 51 in FIG. 6) separates from the horn 8, the chain 4 rotates at a high speed, and the anvil 5 (shown by reference numeral 52 in FIG. It is positioned behind the rearmost anvil 5 (indicated by reference numeral 53 in FIG. 6) via the above-mentioned interval W '(= W). Similarly, when the anvil 5 (53) located at the rearmost end of the chain 4 'separates from the horn 8, the chain 4' rotates at a high speed and the anvil 5 located at the foremost end of the chain 4 '(reference numeral 54 in FIG. 6). (Shown) is positioned behind the anvil 5 (51) located at the rearmost end of the chain 4 via the above-mentioned interval W '. That is, by repeating the above operation, the anvil 5
Even when the film 1 is not installed at equal intervals over the entire area of 4 ', the film 1 can be continuously horizontally sealed at predetermined intervals W and W'.

The specific configuration of the sealing device according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the horizontal sealing means 100 may be replaced with an ultrasonic sealing apparatus having a horn 8 and an anvil 5, and may be a heat sealing apparatus having a hot plate for holding the film 1 or a sealing apparatus using induction heating. Alternatively, a belt or the like made of a flexible member may be used.

Further, the second sealing means 8 is replaced by a horn as shown in the figure, and a transporting means 4 such as a chain, similar to the first sealing means 3, and a direction in which the transporting means 4 is extended. And a plurality of seal bars 5 such as anvils supported at predetermined intervals along the line. In this case, the film 1 is sandwiched between the seal bars 5 of the first and second sealing means 3 and 8, and the transport means 4 of the first and second sealing means 3 and 8 The horizontal seal is performed by moving at a constant speed.

Further, Japanese Patent Application No. Hei.
As shown in No. 1-336856, a space in which the contents are sealed when the contents such as liquid remaining in the horizontal seal portion foams is formed on the distal end surface of the anvil 5 in the horizontal seal portion. May be formed. Further, for the purpose of facilitating the adjustment of the gap between the horn 8 and the anvil 5, the horn 8 and / or the anvil 5 may be provided with a gap adjusting device disclosed in Japanese Patent Application No. 2000-17628 filed earlier by the present inventors. Good.

[0035]

As described above, according to the sealing device of the present invention, it is possible to achieve both improvement of the sealing strength and shortening of the sealing interval at the time of the horizontal sealing, so that the horizontal sealing having a sufficient sealing strength is achieved. The effect that a part can be formed efficiently is acquired.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a lateral sealing means according to a sealing device of the present invention.

2 is a cross-sectional view of the horizontal sealing means shown in FIG.
It is sectional drawing along the line.

FIG. 3 is a side view showing an operation state of the lateral sealing means shown in FIG.

FIG. 4 is a side view showing an operation state of the lateral sealing means shown in FIG.

FIG. 5 is a view exemplifying a schematic configuration of a horizontal sealing means according to the sealing device of the present invention.

FIG. 6 is a side view of the lateral sealing means shown in FIG.

FIG. 7 is a diagram showing an example of the operation of the conventional ultrasonic sealing device at the time of horizontal sealing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film 3 First sealing means 4, 4 'Chain (conveying means) 5 Anvil (seal bar) 8 Horn (second sealing means) 100 Horizontal sealing means

Claims (5)

[Claims] 1. A sealing device comprising a horizontal sealing means for sealing a superimposed film conveyed along a longitudinal direction in a direction intersecting the longitudinal direction, wherein the horizontal sealing means seals the film. It has a first sealing means and a second sealing means sandwiched from the front and back, the first sealing means is an endless conveying means extending along the longitudinal direction of the film, and the conveying means A plurality of seal bars supported at predetermined intervals along the extending direction thereof, wherein the seal bar holds the film between the seal bar and the second sealing means, and the seal bar holds the film. A sealing device that performs the horizontal sealing by moving the transporting means so as to move at the same speed as the film along the transport direction of the film. 2. The seal device according to claim 1, wherein the interval between the seal bars supported by the transport means can be changed. 3. The method according to claim 1, further comprising: moving an endless member constituting the transfer means between the adjacent seal bars into a loop formed by the transfer means, and changing a movement amount of the endless member. 3. The sealing device according to claim 2, wherein the interval between the seal bars can be changed. 4. The horn according to claim 1, wherein the second sealing means is a horn extending parallel to a surface of the film along a longitudinal direction of the film and applying ultrasonic vibration to the film. Item 4. The sealing device according to any one of Items 1 to 3. 5. The endless conveying means similar to the first sealing means, wherein the second sealing means is provided with a plurality of endlessly supported conveying means at predetermined intervals along the direction in which the conveying means extends. And a seal bar, wherein the film is sandwiched between the seal bars of the first and second seal means, and the seal bars of the first and second seal means are arranged along the transport direction of the film. The sealing device according to any one of claims 1 to 3, wherein the horizontal sealing is performed by moving the conveying means of the first and second sealing means so as to move at a constant speed. .