JP2002128021A - Heat-softening method for upper layer film for vacuum packing machine, its device and vacuum packing machine using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve even heat-softening of an upper layer film and vacuum tightness efficiently and effectively for vacuum packing. SOLUTION: A heated air is held in a holding apace by a heating means 3 installed in a housing 11 of a heat-softening device 1. An upper layer film is heat softened by an air transferring means 2 for transferring the heated air by shrinking a volume of the holding space through air holes 12d. A heat- softening device can be designed to generate a heated air by a heating means installed outside of the holding space and to transfer the heated air to the holding space. A base plate 4 for vacuuming is equipped with many cells 42a which are made by separating a recessed space of an air-tight chamber 42 located on a back face of a porous plate 41 as a placing face of goods to be packed. Each cell is connected to a decompressing means 44 by a sucking pipe 43. As a following process after a heat-sealing process, the goods to be packed can be transferred to a supplemental heat-sealing means, and a heat-sealing part of an upper film and a lower film can be heated again from the lower film side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the field of vacuum packaging machines for hermetically packaging confectionery, seafood, or pasty products without damaging them. The present invention relates to an apparatus and a vacuum packaging machine using the same.

[0002]

2. Description of the Related Art A general vacuum packaging machine mainly includes a vacuum pump board (hereinafter referred to as a vacuum pulling board) having a large number of intake holes communicating with an external pressure reducing means (for example, a vacuum pump) formed on a mounting surface. Abbreviated as “base plate”), welding means for heating and welding the upper and lower coating films, and a cover provided on the upper side of the base plate and having a heating source therein. . In the packaging process of such a configuration, first, a porous, lower-layer film that can be ventilated is laid on the mounting surface of the porous plate of the bedboard, and foods and parts to be packaged are placed thereon, and further thereon. The thermoplastic upper layer film is heat-softened to cover the outer shape of the package. Then, using a decompression means such as a vacuum pump, the air in the gap between the packaged object and the upper layer film is sucked from the air hole of the lower layer film to bring the upper and lower layer films into close contact with the outer surface of the packaged object. The upper and lower layer films in the vicinity of the outer periphery of the object are heated and welded to be airtightly packaged.

[0003] The heating source disposed on the above-mentioned cover is for softening the thermoplastic film.
A heating element such as an electric heating tube or a sheathed heater is arranged in a rectangular umbrella-shaped housing, and the radiant heat of the heating element is directly applied to a film to be softened by radiant heat.

[0004] However, despite the fact that the heating step time in the entire vacuum packaging step is about 1/3, in order to soften the thermoplastic film, the heating device is always heated and kept on standby during the operation of the vacuum packaging machine. I had to keep it.

Therefore, for example, 400 mm × 600 mm
A heating device of the order of magnitude requires approximately 12 electric heating tubes of 400 W, which consumes a large amount of power. In addition, since it is open downward, heat loss during standby is large, and the temperature around the heating device becomes high. there were.

In addition, since the heating device is of a radiant type, the amount of heat applied per unit time differs between the central portion and the peripheral portion of the thermoplastic film, making it difficult to uniformly heat the entire thermoplastic film, and There is also a drawback that the degree of softening tends to be different between the central part and the peripheral part.

On the other hand, suction holes are arranged at predetermined intervals in a base plate located on the side opposite to the heating device, and a chamber provided on the entire back surface of the base plate is connected to a decompression device, so that air suction on the base plate is achieved. Although suction is performed from the hole, the pressure is quickly reduced from the suction hole near the suction point where the suction resistance is low because there are few suction points connected to the decompression device with respect to the volume of the chamber conventionally. On the other hand, in a part remote from the suction part, the pressure reduction was slow and the suction unevenness sometimes occurred.

Further, in order to adjust the suction pressure, the pressure must be set on the vacuum pump side as a pressure reducing means, and the adjustment work is troublesome.

In addition, the above-mentioned conventional vacuum packaging machine has a built-in heat generating means for welding on the mounting surface of the base plate.
In a continuous packaging operation, there is a problem that heat remains on the mounting surface and the upper and lower layer films are welded during the suction, so that air remains around the article to be packaged. To avoid this, it is conceivable to remove the heat from the mounting surface every packaging operation.
The waste of energy and time due to repeated heating and heat removal has been a problem.

[0010]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned various problems, and is directed to a vacuum packaging machine for uniform heat softening of an upper layer film of a vacuum packaging machine and for efficient and effective vacuum sealing. An object of the present invention is to provide a method and apparatus for thermally softening an upper layer film, and a vacuum packaging machine using the same.

[0011]

Means for Solving the Problems In order to solve the above problems, a method and apparatus for thermally softening an upper film in a vacuum packaging machine according to the present invention, and a vacuum packaging machine using the same, are configured as follows. You.

That is, in the first aspect of the present invention, an object to be packaged placed on a porous lower film spread on a vacuum pulling board is covered with a thermoplastic upper film, and then vacuum-evacuated and air-tightly packed. In the method for thermally softening the upper film in the above, the heated air is temporarily stored in the storage space (12a),
The heated air in the storage space (12a) is transferred to the upper film (U) through a large number of ventilation holes (12d) which are communicated from the storage space (12a) and arranged over the entire upper surface of the upper film. It is characterized in that it is supplied with air and thermally softened.

According to a second aspect of the present invention, a vacuum packaging machine for covering an object to be packaged placed on a porous lower layer film laid on a vacuum pulling board with a thermoplastic upper layer film and then vacuum-tightly packing the object. In the thermal softening device for an upper film described in the above, a storage space (12a) for storing heated air is provided in a cover (11) covering the entire upper surface of the upper film, and the cover (11) communicates with the storage space (12a). ) Bottom (1
2b), a large number of ventilation holes (12d) are provided, and the storage space (1) is inserted into the ventilation holes (12d).
It is characterized in that an air sending means (2) for sending the heated air in 2a) is provided.

According to a third aspect of the present invention, the air supply means (2) according to the second aspect is performed by contracting the volume of the storage space (12a). According to a fourth aspect of the present invention, the apparatus for thermally softening the upper layer film of the vacuum packaging machine according to the second or third aspect is configured such that heating air is generated by a heating means (3) disposed outside the storage space (12a). (12
a) is sent. According to a fifth aspect of the present invention, the heat softening device for an upper layer film of the vacuum packaging machine according to the second or third aspect is characterized in that a heating means (3) for generating heated air is disposed in a storage space (12a). I do.

In addition, in claim 6, the upper layer film thermal softening device (1) of the vacuum packaging machine according to claim 2, 3 or 4 is connected to an external pressure reducing means (44), and the upper surface is porous. Vacuum platen on which quality lower film is placed (4)
And welding means for heating and welding the lower film and the upper film near the contour of the object to be packaged after the upper film is placed on the object to be packaged placed on the lower film and evacuated, and I have. In a seventh aspect of the present invention, in the vacuum packaging machine according to the sixth aspect, a vacuum pulling board (4).
In the above, a porous plate (4
A large number of cells (42a) are formed by partitioning a concave space of a chamber (42) airtightly arranged on the back side of 1) into multiple sections, and each cell (42a) has a decompression means (44).
And an intake pipe (43) from the outside.

According to an eighth aspect of the present invention, in the vacuum packaging machine according to the sixth or seventh aspect, the article to be packaged is transferred as a post-step of the welding means, and the complementary welding means (5) for completely welding the upper film and the lower film is provided. ) Is provided. Claim 9
Then, the complementary welding means (5) of the vacuum packaging machine according to claim 8
, A storage space (12a) for storing heating air generated outside or inside is provided, and a large number of ventilation holes (12d) communicating upward from the storage space (12a) and opening upward.
, The heated air in the storage space (12a) is discharged at least to the welding site.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for thermally softening an upper film in a vacuum packaging machine according to the present invention, an apparatus therefor,
Specific embodiments of a vacuum packaging machine using the same will be described in detail with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing a vacuum packaging machine of this embodiment, and FIGS. 2, 3 and 4 are side views illustrating steps of a vacuum packaging method of this embodiment.

The basic configuration of the vacuum packaging machine A according to the present embodiment is as follows. The package B placed on the porous lower film L spread on the vacuum platform 4 is made of a thermoplastic upper film U.
After that, the vacuum pump is evacuated from the base plate 4 side, and the upper layer film U is heated and softened to heat-soften the airtight packaging. Therefore, the detailed description of the same components as the conventional one is omitted. .

The first feature of the present invention is that the upper film U
And a heat softening apparatus 1 for heat softening the material. The thermal softening device 1 is disposed at a higher position so as to cover the entire upper surface of the base 4, and forms a cover 11 of the vacuum packaging machine A. The cover 11 has a main body 12 having a storage space 12a formed on a rectangular box having an upper opening and an airtight fit into the upper opening of the main body 12, and moves up and down while maintaining the airtight state. It comprises a movable plate 13. The lower end of a piston rod 21 of a cylinder / piston mechanism is connected to the upper surface of the movable plate 13. The operation of the cylinder 22 may be either air or oil pressure, and a known technique may be appropriately selected and used.

Further, a heating element 31 such as a sheathed heater is disposed in the storage space 12a to form the heating means 3. In addition, in terms of thermal efficiency, the storage space 12a is a heat insulating material 12c,
It is preferable to cover with 13a. Due to the heat generated by the heating element 31, the air in the storage space 12a is heated and the heated air H
It will be stored in a state where. Furthermore, body 1
A large number of ventilation holes 12d communicating with the storage space 12a and opening over the bottom surface 12b of the cover 11 are disposed on the bottom surface 12b side of the second cover 2 so as to be substantially uniform. With this configuration, the air feeding means 2 is formed which pushes out the stored heated air H almost uniformly from the ventilation holes 12d by advancing and moving the piston rod 21 to contract the space volume of the storage space 12a. . If necessary, a nozzle for diffusion (for example, a trumpet-shaped nozzle) is formed in each ventilation hole 12d in order to release the heated air H in a substantially planar and uniform manner.
May be attached.

Next, the second feature of the present invention lies in the structure of the vacuum platform 4 for performing vacuum suction. The base plate 4 has a flat surface on which the mounting surface of the packaged object B is placed and a porous plate 41 having a large number of suction holes 41a vertically penetrated.
On the back surface side, a chamber 42 composed of a concave space opened upward is hermetically attached. In the concave space of the chamber 42, a large number of cells 42a are formed by dividing into multiple sections (in the embodiment, a matrix), and each cell 4a is formed.
An intake pipe 43 communicating with a pressure reducing means 44 described later is connected to 2a. Each intake pipe 43 has a control valve 4
3a is attached, and by adjusting the control valve 43a, the reduced pressure suction force corresponding to each cell 42a is balanced. The pressure reducing means 44 includes an air tank 44a, a suction hose 44b, and a vacuum pump 44c. The air tank 44a is a hollow box-shaped decompression container. The other end of each intake pipe 43 communicating with each cell 42a is connected to the upper surface of the air tank 44a to balance the decompression suction force of each cell 42a. A vacuum pump 44 is provided on the bottom of the air tank 44a.
c is connected to a suction hose 44b communicating with the suction hose 44b.

Further, a third feature of the present invention resides in that complementary welding means 5 after vacuum packaging is provided. As shown in FIG. 4, the complementary welding means 5 includes a heating plate 51 and a belt conveyor 52 a as a transfer means 52. The heating plate 51 is disposed on the back side of the upper belt of the belt conveyor 52a installed adjacent to the vacuum packaging machine A, and is heated to a temperature sufficient for welding the upper and lower layer films U and L. The lower films U and L are completely welded to each other. The belt conveyor 52a is for moving the packaged object B after vacuum packaging to substantially the center thereof by driving the motor 52b.

[0023]

Operation of the Embodiment The embodiment having the above-mentioned structure operates as follows. The basic packaging process is performed in the order described in the above conventional example. That is, first, an air-permeable porous lower film L is laid on the mounting surface of the perforated plate 41 of the base 4, and a packaged object B such as a food or a part is mounted thereon, and furthermore, heat is placed thereon. The plastic upper film U is heat-softened to cover the outer shape of the package B. The packaged object B may be placed for each cell 42a, or may be placed over a plurality of cells 42a.

Here, the heat softening of the upper film U is performed by causing the heated air H stored in the storage space 12a to advance through the piston rod 21 to reduce the volume of the storage space 12a, thereby allowing the upper film U to pass through the air hole 12d. This is performed by discharging heated air H toward the entire surface of U. Here, since the substantially uniform heated air H is radiated from the many air holes 12d arranged evenly, the upper film U is thermally softened evenly. Further, the upper film U descends substantially in parallel by the blowing pressure from the ventilation hole 12d and covers the packaged object B.

Next, when the vacuum pump 44c is started at the same time or in conjunction with the above steps, the air in each chamber 42 is sucked from the suction pipe 43 connected to each cell 42a, and the inside of each cell 42a is homogeneous. A low-pressure atmosphere is formed. And the chamber 4 which is this homogeneous decompression space
A substantially uniform suction force is generated in the suction hole 41a communicating with the second. As a result, substantially even suction is performed from the lower film L around the packaged object B, and uniform welding is performed by contact with the plasticized upper film U. In the case where uneven pressure reduction occurs between the cells 42a, the variation in the suction force is corrected by adjusting the adjustment valve 43a attached to each cell 42a.

When the vacuum evacuation is quickly performed by the above operation, the air surrounded by the packaged object B and the upper and lower films U and L is also sucked and adheres to each other, and the upper film U is thermally softened. The film is welded to each other and
Will be airtightly packaged. Here, further, heat welding,
The upper and lower films U and L can be welded in the vicinity of the outline of the article to be packaged B using a welding means made of an existing technique such as ultrasonic welding (not shown).

After passing through the above steps, the vacuum-packed packaged object B is sent to the complementary welding means 5 side by the transfer means 52 such as a belt conveyor 52a, and heat is generated from the lower film L side on the heating plate 51. By being added, what was incompletely welded in the upper and lower layer films U and L in the previous step is complemented so as to be completely welded.

[Possibility of another embodiment example]

The heating means 3 of this embodiment heats the storage space 12a by heating the storage space 12a by a heater installed in the cover 11, and stores the heated air H through the ventilation hole 12d.
The movable plate 13 of the air supply means is supplied.
Is replaced by a cylinder / piston mechanism, for example, as shown in FIG.
The movable plate 63 is attached via a return spring 64a disposed on the opening edge 62e of the main body 62 as in the thermal softening device 6 shown in FIG.
The cover 61 may be provided with a cam mechanism 64 that moves up and down by driving the 4b. Thus, the air in the storage space 62a heated by the heating element 65 may be kept warm by the heat insulating materials 62c and 63a, and the heated air may be supplied from the ventilation holes 62d provided on the bottom surface 62b. Further, although not shown in the drawings, the rack and pinion mechanism and the ball screw mechanism may be made to move forward and backward. Further, as in a thermal softening device 7 shown in FIG. 6, a blower mechanism 72 having a heating means disposed outside the system is connected to a hollow rectangular box-shaped cover 71,
The heated air introduced into the storage space 71a of the cover 71 may be stored while being kept warm by the heat insulating material 71c, and may be supplied from the ventilation hole 71d provided on the bottom surface 71b.

In addition, the complementary welding means 5 of this embodiment
Is heated by the heating plate 51, but the lower film L
Since the heating method is optional if heating from the side,
For example, like a complementary welding means 8 shown in FIG. 7, a storage box 81 having an upwardly directed ventilation hole 81a is disposed between the upper and lower belts of a transfer means 82 including a mesh belt conveyor 82a and a motor 82b. The heated air may be blown using a blowing mechanism 83 having a heating means disposed outside the box 81.

[0030]

As described above, according to the present invention, since the heat softening device is not an open system as in the conventional device, heat loss and power consumption during standby can be reduced. Further, since the heating device is not a radiation heating device, uniform heating of the entire thermoplastic film can be performed.

Further, cells are formed by partitioning the chambers of the base plate, and the suction pipes are connected to each cell so that a negative pressure state is formed for each cell. More uniform suction (evacuation) can be performed over the entire surface of the substrate.

In addition, when the complementary welding means is provided separately from the base plate, more complete airtight packaging can be realized, and since the heat generating means is not built in the porous plate of the base plate. In addition, it is possible to avoid the problem that the upper and lower layer films are welded before the evacuation is completely completed. Further, there is no need to perform heat removal to avoid inadvertent welding due to residual heat of the perforated plate, thereby shortening the packaging cycle time and enabling rapid continuous packaging work. The utility is remarkable.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a vacuum packaging machine according to an embodiment of the present invention.

FIG. 2 is a side view illustrating the steps of the vacuum packaging method according to the embodiment.

FIG. 3 is a side view for explaining the steps of the vacuum packaging method of the embodiment.

FIG. 4 is a side view for explaining the steps of the vacuum packaging method of the embodiment.

FIG. 5 is a side view showing a thermal softening device according to another embodiment.

FIG. 6 is a side view showing a thermal softening device according to another embodiment.

FIG. 7 is a partially cutaway perspective view showing a complementary welding means according to another embodiment.

[Explanation of symbols]

 A Vacuum packaging machine 1 Heat softening device 11 Cover 12 Main body 12a Storage space 12b Bottom surface 12c Heat insulating material 12d Vent hole 13 Movable plate 13a Heat insulating material 2 Air supply means 21 Piston rod 22 Cylinder 3 Heating means 31 Heating element 4 Base plate 41 Porous Plate 41a Suction hole 42 Chamber 42a Cell 43 Intake pipe 43a Control valve 44 Decompression means 44a Air tank 44b Suction hose 44c Vacuum pump 5 Complementary welding means 51 Heating plate 52 Transfer means 52a Belt conveyor 52b Motor 6 Thermal softening device (other embodiments) 61 cover body 62a storage space 62b bottom surface 62c heat insulating material 62d vent hole 62e opening edge 63 movable plate 63a heat insulating material 64 cam mechanism 64a return spring 64b cam 65 heating element 7 heat softening device (other embodiment) 71 cover71a Storage space 71b Bottom surface 71c Heat insulating material 71d Vent hole 72 Blowing mechanism 8 Complementary welding means (other embodiments) 81 Storage box 81a Vent hole 82 Transfer means 82a Belt conveyor 82b Motor 83 Blowing mechanism B Packaged material H Heated air U Upper layer Film L Lower film

Claims (9)

[Claims] 1. An upper layer film in a vacuum packaging machine which covers an object to be packaged placed on a porous lower layer film laid on a vacuum pulling board with a thermoplastic upper layer film and then evacuates and airtightly packs. In the thermal softening method, heated air is temporarily stored in a storage space (12a), and the storage air (12a)
The storage space (1) is communicated with the storage space (1) through a large number of air holes (12d) arranged over the entire upper surface of the upper film.
2b) A method for thermally softening an upper film of a vacuum packaging machine, wherein the heated air in 2a) is sent to the upper film (U) to be thermally softened. 2. A method for packaging an upper film in a vacuum packaging machine which covers an object to be packaged placed on a porous lower film spread on a vacuum pulling board with a thermoplastic upper film, and then evacuates and airtightly packages the film. In the thermal softening device, a storage space (12a) for storing heated air is provided in a cover (11) covering the entire upper surface of the upper film, and the storage space (12a) communicates with the bottom surface of the cover (11). A large number of ventilation holes (12d) opened over 12b) are provided, and air supply means (2) for sending the heated air in the storage space (12a) to the ventilation holes (12d) is provided. An apparatus for thermally softening an upper layer film of a vacuum packaging machine. 3. The heat of the upper film of the vacuum packaging machine according to claim 2, wherein the air supply means (2) according to claim 2 is performed by contracting the volume of the storage space (12a). Softening device. 4. Heating air is generated by a heating means (3) disposed outside the storage space (12a) to generate heating air.
4. The apparatus for thermally softening an upper film of a vacuum packaging machine according to claim 2, wherein the apparatus is sent to a). 5. An apparatus for thermally softening an upper film of a vacuum packaging machine according to claim 2, wherein a heating means (3) for generating heated air is disposed in the storage space (12a). 6. A heat-softening device (1) for an upper film of a vacuum packaging machine according to claim 2, and connected to an external pressure reducing means (44), and a porous lower film is mounted on the upper surface. The upper film is placed on the vacuum substrate (4) to be placed and the package placed on the lower film, and after evacuating, the lower film and the upper film near the contour of the package are heated and welded. And a welding means. 7. A vacuum suction table (4) in which a concave space of a chamber (42) which is airtightly arranged on the back side of a porous plate (41) on which a package is to be placed is divided into multiple sections. 7. The vacuum packaging machine according to claim 6, wherein the cells (42a) are arranged, and each of the cells (42a) is connected to an intake pipe (43) from a decompression means (44). 8. The vacuum packaging machine according to claim 6, wherein
A vacuum packaging machine comprising a complementary welding means (5) for transferring an article to be packaged as a post-process of the welding means and completely welding the upper film and the lower film. 9. A storage space (12a) for storing heating air generated externally or internally in the complementary welding means 5, and a large number of vent holes communicating with the storage space (12a) and opening upward. The vacuum packaging machine according to claim 8, wherein the heating air (H) in the storage space (12a) is discharged to at least a welding portion via the (12d).