JPH04267724A - Packaging device - Google Patents

Abstract

PURPOSE:To eliminate over-heat of a heat wire or heat block for a sealing device, and prevent a film from being fused during fusion-welding or a heat shrinkable film from shrinking at the time of welding. CONSTITUTION:In a heat block 26 to which a heat wire 28 is attached, an air passage 40 through which pressurized air is made to pass through is formed. At a location which is confronted with the heat wire 28 on the heat block 26, a small hole 44 which communicates with the air passage 40 is provided along the heat wire 28, and the pressurized air is connected to the air passage 40 of the heat block 26.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging device for packaging products using a belt-shaped synthetic resin film and having a sealing device for fusing and welding the opening of the film.

0002

[Prior Art] Conventionally, a packaging device for packaging products using a so-called belt-shaped plastic film has a heat wire for fusing and welding the film provided on the lower surface of a heat block of a sealing device that seals the opening of the film. The heat wire was designed to instantaneously pass a high current through it. In the sealing process, the film wrapped around the product is sandwiched between the heat block and the crimping bar, the opening of the film is crimped and closed, the film is cut and welded using the heat wire, and the product is wrapped in film. was being carried out. The reason for fusing and welding the film is to instantaneously raise the temperature of the heat wire to a high temperature.When fusing and welding the film, if the heating time is too long, the welding of the film will become unstable, and the parts other than the fused part will melt. In the case of a heat-shrinkable film, the film may partially shrink during fusing and welding, so this is to prevent this.

0003

[Problems to be Solved by the Invention] In the case of the above conventional technology, if the sealing work is continued for a long time, the heat block and the heat wire themselves will overheat and reach a high temperature even when no current is flowing. There was a problem in that the temperature was much higher than the desired temperature, making it impossible to control the temperature of the heat wire. Moreover, if it overheats,
There has been a problem that when the film is welded by fusing, parts of the film other than the fusing part melt or the heat-shrinkable film partially shrinks. Therefore, in order to prevent this, we controlled the energization time to the heat wire, attached an air tube to the film holder provided on the outside of the heat block, and sprayed air onto the outer wall of the heat block. In some cases, heat blocks and heat wires were cooled. However, these methods require complicated devices, and it is difficult to control the temperature when controlling the energization time of the heat wire, so that sufficient effects cannot be obtained. Further, even when air was blown onto the outer wall surface of the heat block using the air pipe, the air did not hit the portion of the film that was sandwiched between the heat block and the pressure bar and was welded by welding, resulting in a low cooling effect.

The present invention has been made in view of the problems of the conventional technology described above. It does not overheat the heat wire or heat block, allows stable fusing and welding, and prevents melting of films and heat-shrinkable films. It is an object of the present invention to provide a packaging device that does not shrink during fusing.

[0005]

[Means for Solving the Problems] The present invention forms an air passage through which pressurized air passes inside a heat block to which a heat wire is attached, and provides the air passage on the surface of the heat block facing the heat wire. In this packaging device, a small hole communicating with the heat block is provided along the heat wire, and pressurized air is connected to the ventilation path of the heat block.

[0006]

[Function] The packaging device of this invention forms small holes through which pressurized air blows out along the heat wire of the heat block, thereby preventing the heat wire from overheating and cooling the film being sealed. It is something.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. 1, 2, and 3 show a first embodiment of the present invention. As shown in FIG. The film 10 is unrolled from the film roll 12 wound around the product 14, and the film 10 is rolled out at a predetermined place.
This is to fuse and weld the opening of 0. Further, this packaging device includes a product conveyance belt 16 for feeding the product 14;
A pair of right-angled isosceles triangles are provided in a line with a product conveyance belt 18 that sends out the product, and sandwich the product conveyance belt 16 and open the two-folded film 10 pulled out from the film roll 12 to change the traveling direction. A shaped film opening device 20 is provided.

Product conveyance belts 16 and 18 of this packaging device
In between, a film 10 is placed in a direction perpendicular to the conveying direction of the product 14.
A sealing device 22 is provided to seal the opening of the container, and a heat-resistant seal receiver 24 is provided below the sealing device 22. The seal device 22, as shown in FIGS. 1 and 2,
A heat block 26 such as an aluminum block, and a heat wire 28 stretched over its lower end surface, which is the sealing surface.
It has The heat wire 28 is fixed to attachment arms 30 and 32 that are swingably provided at both ends of the heat block 26 in the longitudinal direction.
The heat wire 28 is connected by the coil springs 34 and 36.
is biased in the pulling direction. This heat wire 28 comes into contact with the film 10 and generates 30A for about 0.5 seconds.
A certain amount of current is passed through the film, and the film is heated to about 400 to 500 degrees Celsius to fuse and weld the film 10. Further, a ventilation passage 40 communicating with the pressurized air inlet 38 is formed inside the heat block 26 , and the ventilation passage 40 opens downward at the lower end surface of the heat block 26 . is blocked by. This insulating resin plate 42
is for ensuring insulation between the heat wire 28 and the heat block 26. This insulating resin plate 42
A plurality of small holes 44 communicating with the ventilation path 40 and formed diagonally toward the heat wire 28 are provided alternately with the heat wire 28 in between. Furthermore, elongated planar heaters 46 for film welding are fixed to the lower end surface of the insulating resin plate 42, located on both sides of the heat wire 28.

The packaging device of this embodiment further includes a sealing device (not shown) disposed on the side of the product conveyance belt 18 for sealing the opening on the side surface parallel to the traveling direction of the film 10 that wraps the product 14. has been done. This sealing device also has the same configuration as the above-described sealing device 22, similarly has a seal receiver, and performs fusing and welding of the film 10.

In the packaging apparatus of this embodiment, a product 14 is conveyed by being placed on a product conveying belt 16, and a film opening device 2
As the product 14 passes through the two folds, the product 14 is sandwiched between the two folded films 10, and from this state, the film 10 is pulled out below the sealing device 22. Here, the leading end of the film 10 is first attached to the sealing device 22.
Cut and weld by cutting. Then, the product 14 is sent, the film 10 sandwiching the product 14 is pulled out below the sealing device, and when the product 14 passes through the sealing device 22,
A sensor (not shown) detects this and the product conveyance belt 1
6 and 18 are stopped.

Then, the sealing device 22 is lowered toward the film 10, and the heat wire 28 seals the film 10.
are fused and welded, and the films inside the fused and welded portion are welded together by the heater 46 to ensure a reliable seal. Here, the sealing time is between the sealing device 22 and the seal receiver 2.
4, the film 10 is pressed for 3 to 4 seconds, and the heat wire 28 is energized for about 0.5 seconds to melt and cut the film 10. At this time, pressurized air is sent from a pressurized air inlet 38 connected to a pressurized air device (not shown), passes through the ventilation path 40, and blows out from the small holes 44. This air continues to be ejected from the state in which the sealing device 22 is pressed against the film 10 until it is lifted away from the film 10, and continues to cool the heat wire 28 and the sealed portion of the film 10. Here, the heat block 26 is pressed against the seal receiver 24, but by keeping the pressure of the pressurized air above a certain level, the pressurized air continues to be ejected from the small hole 44 even during sealing.

Similarly, the opening in the direction parallel to the traveling direction of the product 14 is sealed by a sealing device (not shown) in the next step, and the packaging of the product 14 is completed. After this,
The film 10 is sent into a heat tunnel (not shown) and is shrunk, completing the shrink wrapping. Moreover, if the film 10 is vacuum-packable and air-impermeable,
Vacuum packaging can be performed, and in that case, just before the opening of the film 10 is completely sealed, the air inside the film 10 is suctioned to complete the sealing.

According to the packaging device of this embodiment, pressurized air continues to be blown out from the small hole 44 during the welding by the sealing device 22, and even after long-term use, the heat block 26 and the heat wire 28 are Never overheats. Furthermore, since the heat-shrinkable film 10 does not partially shrink during fusing and welding, the sealed portion can be neatly finished, and the film 10 can be neatly shrunk in the subsequent shrinking step. Further, the small hole 44 is connected to the heat wire 2.
The cooling effect of the heat wire 28 can be enhanced by continuing to blow out air even when the heat wire 28 is separated from the film 10.

Next, a second embodiment of the present invention will be explained based on FIG. 4. Here, the same members as those in the above embodiment are given the same reference numerals and the description thereof will be omitted. The packaging device of this embodiment includes a sealing device 50 as shown in FIG.
This is an L-shaped so-called L sealer, which combines the sealing devices of the above embodiments arranged in a direction perpendicular to and parallel to the film traveling direction.

The sealing device 50 of this embodiment also has an L-shaped heat block 52 and an insulating resin plate 54 provided on the bottom surface of the heat block 52, and a heat wire 56 facing the insulating resin plate 54. is stretched. The insulating resin plate 54 also has small holes 58 arranged alternately along the heat wires 56.
This small hole 58 communicates with a ventilation passage within the heat block 54, and is connectable to an external pressurized air device.

According to the packaging apparatus of this embodiment, the heat wire does not overheat even during long-time sealing operations.
There is no partial shrinkage of the sealed portion of the film during sealing, allowing clean shrink packaging. Moreover, the L-shaped sealing device can efficiently seal openings in two directions simultaneously.

The packaging device of the present invention is not limited to the above-mentioned embodiments, and the film may be a heat-shrinkable film or an ordinary synthetic resin film, and the shape and position of the heat block, Further, the position of the small hole, etc. can be set as appropriate.

[0018]

Effects of the Invention In the packaging device of the present invention, a ventilation path for passing pressurized air is formed in the heat block of the sealing device, and a small hole is provided in the portion facing the heat wire, so that the heat wire and the sealing portion of the film are sealed. Since it is forcibly cooled during sealing, there is no overheating of the heat wire and heat block. Therefore, the film can be fused and welded stably and reliably, without melting of the film, and even if a heat-shrinkable film is used, the sealing part of the film will not shrink during sealing, and the subsequent shrinkage process will not cause the film to melt. The film can be shrunk neatly. This improves the quality of film packaging, making it possible to easily perform high-quality packaging. In particular, in recent years, synthetic resin films with high airtightness have been provided, and even when shrink-wrapping them in a vacuum packaging style, the so-called impulse sealing method using heat wires can be used to cut the welded parts of the film. Clean packaging is possible without partial melting or shrinkage.

[Brief explanation of the drawing]

FIG. 1 is a front view of a sealing device of a first embodiment of a packaging device of the present invention.

FIG. 2 is a partial vertical sectional view of the packaging device according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a packaging device according to a first embodiment of the invention.

FIG. 4 is a perspective view of a sealing device of a second embodiment of the packaging device of the present invention.

[Explanation of symbols]

10 Film 14 Product 22 Seal device 26 Heat block 28 Heat wire 40 Ventilation path 44 Small hole

Claims (1)

[Claims] Claim 1: A packaging device in which a product is wrapped in a belt-shaped synthetic resin film and the opening of the film wrapped around the product is cut and welded using a heat wire. Forming a ventilation path for passing pressurized air inside the block,
A small hole communicating with the ventilation path is provided along the heat wire on the surface of the heat block that faces the heat wire and is pressed to the film, and pressurized air is connected to the ventilation path of the heat block. A packaging device characterized by: