JP2000177715A - End seal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an end seal device in which an entire seal section can be pressurized uniformly without causing damage to a packing film and a desired seal state can be attained. SOLUTION: A pair of seal surfaces of sealer oppositely arranged with a packing film being held therebetween are formed with a lateral corrugated seal having corrugations of predetermined pattern, i.e., grooves 20 and protrusions 21. A partial axial section of the sealer (for example, a location opposing against the center seal section) is formed with a low stepped part 23 where the surface position of the seal section is entirely lowered only by a distance (d). With such an arrangement as above, the low stepped portions are oppositely faced at the center seal section where many overlapped film sheets are found, so that the entire film can be pressurized with a uniform pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end seal device, and more particularly, to an improvement in the structure of a seal surface.

[0002]

2. Description of the Related Art At the last stage of various packaging machines, there is disposed an end sealing device which seals (usually simultaneously cuts) in the advancing direction of a packaging film containing an article to be packaged. By sealing (end seal) in the lateral direction, the packaged object is sealed for each individual package.

An example of such an end seal device is shown in FIG. 1. A sealer 2 is attached to a pair of rotating shafts 1 disposed with a packaging film interposed therebetween, so that the sealer 2 is integrally rotated. 2 opposing sealing surfaces 2
A predetermined seal is formed on a. With this sealing eye, a desired eye (unevenness) is formed on the end seal portion of the package.
Is formed and is tightly heat sealed.

The seal surface 2a is an arc-shaped curved surface corresponding to the radius of rotation of the sealer 2. If the shape of the seal is, for example, a horizontal line waveform, as shown in FIG.
Extend, and become wave-shaped in the rotation direction (the direction orthogonal to the axial direction). The grooves 3 (shown by broken lines) formed on the sealing surface 2a of the opposing sealer 2 are arranged alternately, and as shown in FIG. Has become.

[0005] As a result, the end seal portion 5 of the package 4 formed as shown in FIG. 3 is deformed along the seam of the seal surface 2a to form an eye extending parallel to the side edge. Is done.

[0006]

However, the above-mentioned conventional end seal device has the following problems. That is, since the end seal portion 5 folds the packaging film 6 normally formed into a tubular shape,
There will be one film. If the package 4 is of a pillow type, the center seal portion 7 seals a portion where both edges in the traveling direction of the package film are overlapped.
Is present, the end seal portion 5 intersecting the center seal portion 7 is in a state in which four (in the case of attaching to a palm) or three (in the case of attaching to an envelope) packaging films are overlapped. Therefore, only that portion has a larger film thickness than other portions.

As a result, the sealing surfaces 2 of the pair of sealers 2
Since the interval between a is normally set in consideration of the thickness of the two films, the interval where the center seal portion 7 overlaps is narrow with respect to the film thickness, and a large pressure is applied to the packaging film. Then, at the end seal portion where the center seal portion 7 overlaps, the packaging film may be crushed and torn, causing a seal leak. This is particularly true when a material having low stretchability such as aluminum is used as the material of the packaging film.

Conversely, if the interval between the sealing surfaces 2a is set in accordance with the portion where the center seal portion 7 overlaps, the pressing force becomes insufficient in a region other than the center seal portion 7, resulting in poor sealing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and has as its object to solve the above-mentioned problems and to uniformly pressurize the entire sealing portion without damaging the packaging film. An object of the present invention is to provide an end seal device capable of achieving a desired sealing state.

[0010]

In order to achieve the above-mentioned object, an end sealing device according to the present invention has a pair of sealers arranged to face each other with a packaging film interposed therebetween. An end seal device that heat seals a contact portion of the packaging film by holding and heating the packaging film at a predetermined pressure, wherein a seal stitch having a predetermined pattern of irregularities is formed on a seal surface of the sealer, A low step portion is formed in a part of the sealer in the axial direction, in which the surface position of the seal is lowered as a whole (Claim 1).

[0011] Preferably, the area where the low step portion is formed is a part of the sealer in the axial direction and the entire surface of the seal surface in a direction orthogonal to the axial direction. 2). Furthermore, it is preferable that the region where the low step portion is formed is at least one of a position facing the center seal portion of the package to be manufactured and a position facing both side edges of the package (claim 3).

The end seal portion of the package is formed by overlapping and sealing a plurality of packaging films.
At that time, if, for example, a center seal portion or a gusset is present, the number of sheets on which the packaging film overlaps is increased as compared with other portions. Therefore, by providing a low step portion at a position (a part in the axial direction) opposed to the overlapping portion, the distance to each portion of the packaging film becomes uniform over the entire sealing surface, and it is necessary for a portion where the overlapping number is large. As described above, the application of excessive pressure is suppressed, and the film can be prevented from being damaged or broken, and can be reliably sealed.

[0013] Since the low step portion has the surface shape of the sealing eye lowered as a whole (including the depth of the groove), it can be firmly applied to the surface of the film portion where the center seal portion and the gusset are formed. A seal is formed.

[0014]

4 to 7 show a preferred embodiment of an end seal device according to the present invention. The figure shows a sealer 10 constituting a main part of the end seal device. In practice, the end seal device is configured by attaching the sealer 10 to each of the pair of rotating shafts.

FIG. 4 is a front view of the sealer 10, and FIG.
Is a plan view thereof, and FIG. 6 shows a side view thereof.
FIG. 7 is an enlarged view of a sealing surface which is a main part of the present invention.

As shown, the lower side in FIGS. 4 and 6 is a wide mounting surface 10a, and this mounting surface 10a is mounted on the peripheral surface of a rotating shaft (not shown). And the mounting surface 10
In a, both ends in the axial direction protrude outward, a through hole 11 is formed in the protruding portion, and the a is fixed to the rotating shaft by a screw passing through the through hole.

As shown in FIG. 6, the main body of the sealer 10 becomes narrower as it goes upward in the figure, and its tip forms an arc-shaped sealing surface 12. And sealer 1
0, a heater 1 is provided inside the body so as to extend in the axial direction.
3, a heat pipe 14 is buried, and a thermocouple 15 is disposed near the sealing surface 12 to control the heater 13 so that the temperature of the sealing surface 12 becomes a desired temperature by detecting the temperature. It is supposed to.

Further, on the center line of the sealing surface 12,
A cutting blade 16 is formed, and the packaging film is cut by the cutting blade 16. When the cutting blade 16 is built in one sealer 10 as shown in the drawing, a receiving portion is formed on the other sealer at a position facing the cutting blade, and a receiving portion is formed between the cutting blade 16 and the receiving portion. And cut by sandwiching the packaging film. Since the above-described components are the same as those of the related art, detailed description thereof will be omitted.

Here, according to the present invention, as shown in FIG. That is, a large number of grooves 20 extending in the axial direction are formed,
Adjacent grooves 20 are connected by a smooth curve. That is, FIG. 7A showing an enlarged Y portion in FIG.
The groove 20 and the ridge 21 are alternately arranged so that the waves travel in the rotation direction (the direction orthogonal to the axial direction of the sealer 10). Although not shown in the drawing, a substantially same shape seal is formed on the seal surface of the sealer on the mating side so that the own groove 20 and the ridge 21 on the mating side are opposed to each other.

The interval between the sealing surfaces 12 when the packaging film is sandwiched between the pair of sealers 10 and heat-sealed is basically set in consideration of the thickness of the two packaging films. I have. Then, as shown in FIGS. 4 and 5, the sealing line in the region 23 between the center of the sealing surface 12 in the axial direction and a predetermined distance X (for example, a length of 10 mm) on one side (the right side in the drawing) is totally removed. Constant distance (for example, 0.08 mm) d
The low step portion 23 is dug down only.

That is, as shown in FIG. 7A, in a normal region, the groove 20 and the ridge 21 are formed at positions shown by solid lines, and the low step portion 23 has The groove 20 and the ridge 21 are formed at a position lower by the distance d as a whole. In addition, one ridge 21
Focusing on the (groove 20), as shown in FIG. 3B, only the region of the low step portion 23 is lower by one step, and the upper end (lower end)
Are different in absolute position (e.g., distance from the mounting surface 10a), but this shape (relative positional relationship) is the same in each part of the seal surface in the rotation direction.

The low step portion (predetermined region) 23 is a region facing the center seal portion of the pillow package. Therefore, the length in the axial direction is determined according to the width of the center seal portion. The distance d is determined in consideration of the increase in the film thickness due to the center seal portion in the pillow package.

By adopting such a configuration, even in the case of a normal end seal portion, a portion intersecting the center seal portion and having a large number of overlapping films, the low step portion 23 can be used.
Is provided, the pressure can be evenly applied to the entire end seal portion on the seal surface 12, and a uniform seal can be formed and the seal can be reliably performed.

In the above embodiment, the low step portion 2
Although an example in which 3 is formed only in the vicinity of the center facing the center seal portion has been described, the present invention is not limited to this. For example, as shown by a two-dot chain line in FIG. Good. And the position of the low step part 24 in this case becomes both end edges of the end seal part of the package. In other words, in the case of a package with a gusset, since both side edges of the packaging film formed into a tubular shape are folded inward, there are four packaging films at both end edges of the end seal portion. Therefore, since the same problem as the above-described problem occurs in the center seal portion, the region where the gusset is formed is set as the low step portion 24, so that the entire end seal portion is uniformly pressurized and securely sealed. I have to.

Further, the sealer 10 forming the low step portion 23 as described above may be formed on the seal surfaces of both sealers of the pair of sealers, or may be formed only on the seal surface of one of the sealers. Good. Preferably, the low step portion 23 corresponding to the center seal portion is formed only on the sealer on the side where the center seal portion is formed,
In the case of the low step portion 24 corresponding to the gusset (formed at both ends), it is necessary to form the low step portion 24 on both the sealers because the film becomes thick on both sides of the film.

In order to form the low step portion having the above structure,
For example, a seal surface is dug by a predetermined distance while moving along an axial direction by an end mill using grains of φ0.7 mm. The digging depth can be formed by digging a predetermined distance d deep from a normal position (each position on the corrugated surface indicated by the solid line in FIG. 7A).

Further, in the above-described embodiment, the description has been given of the seal stitches having a horizontal corrugation. However, it is needless to say that the present invention is not limited to this and can be applied to seals having various shapes. Further, the end seal device to be applied is not limited to a rotary type, but can be applied to various types such as a so-called box motion type and a type of simply moving forward and backward.

[0028]

As described above, in the end seal device according to the present invention, the end seal is provided by providing the low step portion on the seal surface corresponding to the place where the number of wrapping films is large in the end seal portion. Pressure can be evenly applied to the entire film portion of the packaging film. as a result,
A desired sealing state can be obtained without damaging the packaging film.

[Brief description of the drawings]

FIG. 1 is a view showing a general shape of an end seal device (rotary type).

FIG. 2 is a diagram illustrating seal eyes.

FIG. 3 is a view showing a package.

FIG. 4 is a front view showing a sealer in a preferred embodiment of the end seal device according to the present invention.

FIG. 5 is a plan view showing a sealer in a preferred embodiment of the end seal device according to the present invention.

FIG. 6 is a side view showing a sealer in a preferred embodiment of the end seal device according to the present invention.

FIG. 7 is an enlarged view of a main part showing a sealer in a preferred embodiment of the end seal device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sealer 12 Seal surface 20 Groove 21 Ridge 23, 24 Low step

Claims (3)

[Claims] 1. A sealer having a pair of sealers disposed opposite to each other with a packaging film interposed therebetween, wherein the sealing film is heated while being held at a predetermined pressure by a sealing surface of the sealer, so that a contact portion of the packaging film is heat-sealed. An end seal device, wherein a seal stitch made of a predetermined pattern of irregularities is formed on a seal surface of the sealer, and a part of the sealer in an axial direction is
An end seal device, wherein a low step portion is formed by lowering the surface position of the seal eyes as a whole. 2. The area where the low step portion is formed is a part of the sealer in the axial direction, and is the entire surface of the seal surface in a direction orthogonal to the axial direction. An end seal device according to item 1. 3. The region where the low step portion is formed is at least one of a position facing a center seal portion of a package to be manufactured and a position facing both side edges of the package. 3. The end seal device according to 1 or 2.