JP2004051175A - Shrink wrapping apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shrink wrapping apparatus, which enables a rapid and consecutive shrink wrapping process and prevents projected corners of a wrapping film from projecting from a wrapped article. <P>SOLUTION: The shrink pack wrapping apparatus 1 comprises a transfer means 2 for transferring rectangular, bag-shaped thermally shrinkable films F in each of which the article P is wrapped up, and a heating means 3 for heating each thermally shrinkable film F. The transfer means 2 is a belt conveyor, which comprises a drive rotating wheel 20, a driven rotating wheel 21, and an endless belt 22 wound on both rotating wheels. The heating means 3 comprises a main heating means 4 for heating the whole of the film F, a spot heating means 5 for heating only the projected corners E of the film F, and a following means 6 for making the spot heating means 5 follow the film F that is transferred by the transfer means 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shrink wrapping apparatus that packages food, merchandise other than food, containers containing the food, and the like with a heat-shrinkable film, and that can perform such wrapping quickly and continuously.
[0002]
[Prior art]
DESCRIPTION OF RELATED ART Conventionally, the technique of shrink packaging which wraps an article to be packaged with a heat-shrinkable film is well known. As a general method, as shown in FIGS. 9A to 9C, while the articles to be packaged P are placed on a belt conveyor or the like and conveyed in a straight line, the articles to be packaged P are chased from above. Then, a heat-shrinkable film F0 in which a heat-shrinkable polypropylene-based resin or the like is formed into an extremely thin strip is supplied. The both sides of the heat-shrinkable film F0 are butted and welded below the article to be packaged P, so that the heat-shrinkable film F has a tubular shape in which the article to be packaged P is accommodated.
[0003]
Further, one end f1 of the heat-shrinkable film F1 having a cylindrical shape is sealed by being melted by heat, and an appropriate portion (the other end) f2 of the heat-shrinkable film F1 is cut by being melted by heat and sealed. As a result, the heat-shrinkable film F1 has a rectangular bag shape in plan view and contains the article to be packaged P. The above steps are repeated for each packaged object P.
[0004]
Further, as shown in FIG. 10, the bag-shaped heat-shrinkable film F containing the article to be packaged P is placed on the belt conveyor C and introduced into the heat tunnel H. The heat tunnel H blows out hot air from a large number of holes formed in both side surfaces h1 and the top surface h2 of the inside thereof. The entire heat-shrinkable film F including the article to be packaged P is heated substantially uniformly in the process of passing through the inside of the heat tunnel H. As a result, the entire heat-shrinkable film F shrinks and adheres to the packaged object P. At the same time, the air confined in the bag-shaped heat-shrinkable film F is discharged through pinholes that have been perforated in the heat-shrinkable film F in advance.
[0005]
[Problems to be solved by the invention]
According to the above method, since the entire bag-shaped heat-shrinkable film F shrinks substantially uniformly, as shown in FIG. 6, the diagonal of the bag-shaped heat-shrinkable film F, that is, the most from the center of the rectangle. Only the four corners E that are located far away protrude without being in close contact with the packaged object P. This tendency becomes more remarkable when the packaged object P is circular.
[0006]
The above-mentioned protruding corner portion E is commonly referred to as “one” and is hardly protruded. When a plurality of objects to be packaged P packed with the heat-shrinkable film F are arranged side by side, adjacent heat-shrinkable films F are damaged. Cause you to Alternatively, a person who handles the packaged object P packaged with the heat-shrinkable film F may be hurt by, for example, catching one's hand.
[0007]
Therefore, in a step different from the step of introducing the heat-shrinkable film F containing the article to be packaged into the heat tunnel H, only the protruding corner portion E of the bag-shaped heat-shrinkable film F is further heated. Attempts were made to substantially eliminate the "one" by locally shrinking the protruding corner E locally compared to the entire heat-shrinkable film F. Alternatively, it has been attempted to eliminate the protruding corner portion E by cutting the four corners of the bag-shaped heat-shrinkable film F into a shape in which the bag-shaped heat-shrinkable film F is chamfered.
[0008]
However, since the step of locally heating or removing the protruding corner portion E must be performed separately from the step of introducing the heat-shrinkable film F containing the article to be packaged into the heat tunnel H, the step is accordingly increased. This causes a problem that the time required for the entire process of shrink packaging is delayed. In addition, when the four corners of the bag-shaped heat-shrinkable film F are cut off, the cut-off portions may be arranged at unexpected positions on the packaged object P, and the chips may be generated. Also happens.
[0009]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a shrink wrapping apparatus in which shrink wrapping can be performed quickly and continuously, and in which a protruding corner does not protrude from an object to be wrapped.
[0010]
[Means for Solving the Problems]
The shrink wrapping device according to the present invention includes a conveying unit that conveys a bag-shaped heat-shrinkable film containing an article to be packaged, and a heating unit that heats the heat-shrinkable film. The feature is that, while the entire heat-shrinkable film is heated by the heating means, the heating temperature of the protruding corner formed at the end of the heat-shrinkable film is relatively high.
[0011]
Further, in the shrink packaging apparatus according to the present invention, the heating means is conveyed by the main heating means for heating the entire heat-shrinkable film, the spot heating means for heating the protruding corner of the heat-shrinkable film, and the conveyance means. The heat shrinkable film is provided with follow-up means for moving the spot heating means.
[0012]
Further, in the shrink wrapping device according to the present invention, the follower moves the ejection port for ejecting the hot air to the corner of the heat-shrinkable film together with the corner of the heat-shrinkable film.
[0013]
Further, in the shrink wrapping device according to the present invention, the follower means forms a chamber inside the endless belt running in synchronization with the transport means, and forms an injection port in the endless belt. It is.
[0014]
Further, the shrink wrapping device according to the present invention, as a method of relatively increasing the heating temperature of the protruding corner formed at the end of the heat shrinkable film, when injecting hot air from the heating means to the heat shrinkable film A regulating panel for blocking hot air from the heating means toward the periphery of the corner of the heat-shrinkable film between the heating means and the heat-shrinkable film; It is designed to move in the direction in which the conductive film is transported.
[0015]
Further, in the shrink wrapping device according to the present invention, the regulating panel is attached to an endless chain that travels in accordance with a transporting means.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
A shrink packaging device according to an embodiment of the present invention will be described with reference to the drawings. Hereinafter, the description of the same configuration as that of the related art will be omitted.
[0017]
FIG. 1A is a horizontal sectional view of a shrink wrapping apparatus 1 according to the present embodiment, and a longitudinal sectional view thereof is shown in FIG. As shown in FIGS. 1 and 2, the shrink wrapping apparatus 1 heats the heat-shrinkable film F by a conveying unit 2 that conveys a rectangular bag-shaped heat-shrinkable film F including the article P to be wrapped. Heating means 3.
[0018]
The transport means 2 includes a drive rotating wheel 20 and a driven rotating wheel 21 arranged at intervals in a horizontal direction indicated by an arrow X in FIG. 1, and an endless belt 22 is provided on the driving rotating wheel 20 and the driven rotating wheel 21. Is a belt conveyor around which is wound. The packaged object P and the heat-shrinkable film F are introduced from one end of the heat tunnel H as the endless belt 22 runs, and are conveyed to the other end. This series of transport directions is defined as an arrow X direction from left to right in the drawing for convenience of description.
[0019]
The heating means 3 includes a main heating means 4 for heating the entire heat-shrinkable film F, a spot heating means 5 for heating only the protruding corner portion E of the heat-shrinkable film F, and a heat-shrinkable material conveyed by the conveying means 2. And a follow-up means 6 for causing the spot heating means 5 to follow the film F.
[0020]
The main heating means 4 is a heat tunnel H and a heat source mounted thereon. Its main configuration is to blow air into the heat tunnel H again by the blower 10 while heating the air in the heat tunnel H with an electric heater (not shown). Although both ends of the heat tunnel H are always open, a discharge port of an air passage 10a for guiding hot air blown from the blower 10 is provided at one end of the heat tunnel H, and a suction port of the blower 10 is provided at the other end of the heat tunnel H. By providing, the hot air can be circulated in the heat tunnel H while flowing in the direction of the arrow X.
[0021]
With the above configuration, it is possible to suppress the air outside the heat tunnel H from entering the heat tunnel H, and at the same time, prevent the hot air inside the heat tunnel H from being released to the outside. Further, the temperature in the heat tunnel H can be maintained at a temperature at which the heat-shrinkable film F shrinks. Since the technology relating to the heat tunnel H described above is well known, detailed illustration thereof is omitted.
[0022]
The spot heating means 5 arranges a pair of chambers 7 for accumulating hot air in the vicinity of the transport means 2, and a plurality of jets for jetting hot air to the pair of chambers 7 at the corners E of the heat-shrinkable film F. Each of the ports 8 is formed, and the positions of the plurality of injection ports 8 are moved together with the protruding corner E of the heat-shrinkable film F by the follow-up means 6 synchronized with the conveying means 2.
[0023]
More specifically, the follower 6 forms a chamber 7 inside the endless belt 9 running in synchronization with the transporter 2, and has a plurality of injection ports 8 formed at appropriate places on the endless belt 9. . The endless belt 9 is wound around a driving wheel 90 and a driven wheel 91 provided near both ends of the heat tunnel H, respectively. That is, the follower 6 uses the space inside the endless belt 9 as the chamber 7 as shown in a cutaway view in FIG. 2, and the endless belt 9 is connected to the space in the heat tunnel H and the chamber 7. It plays the role of an outer wall that partitions
[0024]
As shown in FIG. 1, a shielding panel 92 may be provided in the chamber 7. That is, since the endless belt 9 has a structure in which hot air is injected from substantially the entire circumference through the injection port 8, the injection is performed at a part other than the injection port 8 which directly injects the hot air to the corner E of the heat-shrinkable film F. For the purpose of positively suppressing hot air from leaking from the port 8, a shielding panel 92 that closes the injection port 8 from the back side of the endless belt 9 may be provided.
[0025]
As a heat source of the spot heating means 5 for supplying hot air into the chamber 7, the electric heater and the blower 10 applied to the main heating means 4 may be shared. That is, hot air may be pressure-fed into each chamber 7 via another air path 10b provided in the blower 10. Further, in this case, the above-described wind path 10a may be omitted, and the entire heat-shrinkable film F may be heated by using the residual heat of the hot air supplied from the chamber 7 via the injection port 8 to the heating of the outgoing corner E. .
[0026]
Alternatively, the air in the heat tunnel H may be heated and pressurized by another blower or the like while being heated by an electric heater or the like different from the one applied to the main heating means 4, and the hot air may be pressure-fed into the chamber 7. good. Another electric heater or the like may be, for example, a heat source that assists the main heating unit 4 and further heats the air in the heat tunnel H to a higher temperature. In FIG. 2, gaps are opened between the upper and lower edges of the endless belt 9 and the top and bottom surfaces of the heat tunnel H. Hot air leaking slightly from these gaps is blown again by the blower 10. And is pumped into the chamber 7.
[0027]
The plurality of injection ports 8 are small holes perforated at appropriate places of the endless belt 9, and are arranged so as to correspond to the protruding corner portions E of the heat-shrinkable film F. That is, as shown in FIG. 1, the plurality of injection ports 8 pierce the endless belt 9 at a pitch equal to the pitch of the protruding corner portions E of the individual heat-shrinkable films F conveyed at equal intervals by the conveying means 2. Have been. Further, the plurality of injection ports 8 are arranged at the height of a protruding corner portion E protruding from the peripheral surface of the article to be packaged P.
[0028]
As the form of the injection port 8, a round hole may be used as exemplified above, but instead of the injection port 8, a vertical slit 12 extending in the vertical direction as shown in FIG. 3 may be formed in the endless belt 9. FIG. 1A shows the side surfaces of the endless belt 9 facing each other in FIG. 1A. For example, the regulating panels 13 which cover the side surfaces and have horizontal slits 13 extending in the horizontal direction are overlapped. For example, the injection port 8 can be formed at the intersection of the vertical slit 12 and the horizontal slit 13.
[0029]
In this case, if the pitch of the vertical slits 12 is increased or decreased, or a plurality of regulating panels 14 having different height positions of the horizontal slits 13 are prepared, these vertical slits 12 and the horizontal slits 13 are arbitrarily combined. Thereby, the position where the injection port 8 opens can be freely changed according to the shape of the heat-shrinkable film F. Further, the vertical slit 12 may be formed in the regulating panel 14 and the horizontal slit 13 may be formed in the endless belt 9.
[0030]
The shrink wrapping device 1 according to the present embodiment illustrated above should not be understood as substantially limiting the technical idea of the present invention. The shrink wrapping device is implemented while appropriately improving, changing, or adding the same to a person skilled in the art without departing from the gist of the shrink wrapping device.
[0031]
For example, slide rails 15 as shown in FIG. 4 are attached to both sides of the heat tunnel H in a posture along the transport direction of the transport means 2, and sliders 16 slidably engaged with the slide rails 15. The nozzle 17 may be attached to the nozzle 17 and hot air may be sprayed from the nozzle 17 to the corner E while the nozzle 17 is reciprocated. The nozzle 17 injects hot air pressure-fed from the blower 10 through the flexible hose 17a toward the corner E of the heat-shrinkable film F. That is, the nozzle 17 plays the role of the injection port 8.
[0032]
A chamber 7 made of a long hollow body as shown in FIG. 5 is attached to each side surface of the heat tunnel H in a posture along the carrying direction of the carrying means 2. A plurality of solenoid on-off valves 18 may be mounted along the transport direction. In this case, of the plurality of electromagnetic on / off valves 18, the electromagnetic on / off valve 18 closest to the protruding corner E of the heat-shrinkable film F conveyed by the conveying means 2 is moved from the upper side in the conveying direction (arrow X). (Sequentially in the direction). Thereby, the hot air injected from each of the electromagnetic on-off valves 18 can be reliably injected only to the protruding corner portion E.
[0033]
Further, the inside of the endless belt 22 of the above-mentioned conveying means 2 may be a chamber 70 for accumulating hot air. In this case, the endless belt 22 is formed with an injection port 80 for injecting hot air to the protruding corner E. The above-described injection port 8 and the injection port 80 may be used in combination, or the injection port 8 may be omitted and the projected corner portion E may be heated only by the injection port 80.
[0034]
Further, as shown in FIG. 6A, a hose 81 for guiding hot air from the injection port 8 to the vicinity of the corner E of the heat-shrinkable film F may be attached to the endless belt 9. Further, if the hose 81 is made of a material that can freely deform plastically, it can easily cope with a slight change in the position of the protruding corner portion E depending on the shape of the article to be packaged P. Further, as shown in FIG. 6B, the endless belt 9 may be provided with a variable nozzle 82 capable of arbitrarily setting a direction in which hot air is jetted.
[0035]
The variable nozzle 82 has a nozzle body 83 having a substantially spherical end 83a, a support 84 having a substantially spherical concave portion 84a that slidably contacts the end 83a, and fixed to the endless belt 9; A nut 85 for fastening the nozzle body 83 to the support 84. When the nut 85 is loosened, the direction of the nozzle body 83 can be freely changed.
[0036]
Next, a shrink wrapping apparatus 40 according to another embodiment of the present invention will be described with reference to the drawings. Hereinafter, the same reference numerals are given to the same configurations as the related art and the above-described embodiments, and the illustration and description thereof are omitted.
[0037]
As shown in FIG. 7, the shrink wrapping apparatus 40 includes a heating unit 30 for heating the heat-shrinkable film F. Although not shown in the figure, the shrink wrapping apparatus 40 has the same mechanism as the above-described conveying means 2 and can convey a bag-shaped heat-shrinkable film F containing the article to be packaged P. The feature is that hot air is jetted from the heating means 30 to the heat-shrinkable film F, and between the heating means 30 and the heat-shrinkable film F, the heating corner 30 of the heat-shrinkable film F is exposed. Is to dispose a regulating panel 31 for blocking the hot air heading toward the surroundings, and move the regulating panel 31 in the direction of the arrow X in which the heat-shrinkable film F is transported in synchronization with the transporting means 2.
[0038]
As the heating means 30, hot air blown out from a number of holes formed in both side surfaces h1 inside the heat tunnel H is used. Inside the heat tunnel H, follow-up means for moving the regulation panel 31 in synchronization with the transport means 2 is provided. Specifically, a pair of driving rotary wheels 32 and a pair of driven rotary wheels 33 are provided near both ends of the heat tunnel H, respectively. Each part is attached.
[0039]
The heating means 30 may be installed inside the endless chain 34 as shown by the phantom line in FIG. In this case, the electromagnetic opening / closing valve 18 may be removed from the chamber 7 of the embodiment already illustrated in FIG. 5, and hot air may be simultaneously injected from the plurality of injection ports 8 of the chamber 7 toward the heat-shrinkable film F.
[0040]
As shown in FIG. 8, the outer dimensions of the regulating panel 31 are set to be larger than the outer dimensions of the article to be packaged P, and the regulating panel 31 is moved from the heating means 30 to the protruding corner E of the heat-shrinkable film F. You may form the ventilation hole 35 which lets the hot air which flows go.
[0041]
【The invention's effect】
According to the shrink wrapping device of the present invention, in addition to heating the entire heat-shrinkable film, only the outer corner of the heat-shrinkable film is heated by the spot heating means, so that the shrinkage rate of the outer corner is relatively small. And the protruding corner portion is brought into close contact with the article to be packaged. Therefore, the protruding corners are less likely to protrude from the packaged object, so that adjacent heat-shrinkable films may be damaged during packing, or may be injured by catching a hand on the protruding corners as in the related art. There is no.
[0042]
In addition, since the spot heating means for heating only the corners of the heat-shrinkable film is followed by the heat-shrinkable film conveyed with the packaged object, a step of heating the entire heat-shrinkable film; The step of heating only the outer corner of the film can be performed at the same time. Therefore, the protruding corner portion is brought into close contact with the article to be packaged without delaying the time required for the entire process of shrink wrapping, and the above-described effects can be obtained.
[0043]
Furthermore, according to the shrink wrapping device of the present invention, a chamber for storing hot air is disposed in the vicinity of the conveying means, and the hot air is jetted to the protruding corner of the heat-shrinkable film through the jet port formed in the chamber. This eliminates the need for piping for guiding hot air to the corner.
[0044]
Therefore, heat loss in the process or path of injecting hot air can be minimized. In addition, since the position of the injection port is moved in synchronization with the transfer means, a mechanism for moving the chamber itself is not required. Therefore, the structure is simple, the manufacturing cost can be reduced, and the shrink wrapping device can be easily added to an existing heat tunnel or the like.
[0045]
Further, according to the shrink wrapping device of the present invention, the endless belt plays a role of partitioning the inside and the outside of the chamber by forming the injection port in the endless belt having the chamber formed inside. Further, since the position of the injection port can be changed only by running the endless belt, the number of parts can be minimized. In addition, since the chamber itself can be extremely thinned while having the function of changing the position of the injection port in the chamber, it greatly contributes to downsizing of a heat tunnel or the like that houses the chamber.
[0046]
Further, according to the shrink wrapping device of the present invention, the hot air injected from the heating means to the heat-shrinkable film is blocked by the control panel, so that the hot air directly hits the periphery of the corner of the heat-shrinkable film. Restriction, so that the hot air directly hit only the outer corner of the heat shrinkable film, so that the heating temperature of the outer corner is relatively high, the shrinkage is relatively increased, The protruding corner can be brought into close contact with the article to be packaged. Therefore, there is no danger of adjacent heat-shrinkable films being damaged during packaging, or being injured by catching a hand at a protruding corner.
[0047]
Furthermore, according to the shrink wrapping device of the present invention, since the regulating panel is attached to the endless chain running in synchronization with the conveying means, the heat that moves with the wrapped object in the process of conveying the wrapped object. The flow of the hot air can be maintained such that the hot air directly hits the corners of the shrinkable film. Therefore, simultaneously with heating the entire heat-shrinkable film, it is possible to particularly heat the protruding corners of the heat-shrinkable film, so that the protruding corners are brought into close contact with the packaged object without delaying the time required for the entire process of shrink packaging. Can be
[Brief description of the drawings]
FIG. 1 is a horizontal sectional view and a vertical section of a shrink wrapping device according to an embodiment of the present invention.
FIG. 2 is a cutaway view of a main part of the shrink wrapping device according to the embodiment of the present invention.
FIG. 3 is a side view illustrating a modified example of the injection port applied to the shrink packaging device according to the embodiment of the present invention.
FIG. 4 is a plan view showing a modification of a follower applied to the shrink wrapping device according to the embodiment of the present invention.
FIG. 5 is a plan view showing a further modification of the follower applied to the shrink wrapping device according to the embodiment of the present invention.
FIG. 6 is a side view showing a further modified example of the injection port applied to the shrink wrapping device according to the embodiment of the present invention.
FIG. 7 is a plan view and a side view showing a main part of a shrink wrapping device according to another embodiment of the present invention.
FIG. 8 is a side view showing a modified example of a main part of a shrink wrapping device according to another embodiment of the present invention.
FIG. 9 is a conceptual diagram illustrating the principle of a general shrink pack.
FIG. 10 is a horizontal sectional view and a vertical sectional view of a conventional shrink wrapping apparatus.
[Explanation of symbols]
1: Shrink packaging device 2: Conveying means 3: Heating means 4: Main heating means 5: Spot heating means 6: Follow-up means 7, 70: Chambers 8, 80, 81, 82: Injection port E: Outer corner F: Heat shrinkable film P: Packaged material

Claims (6)

Conveying means for conveying a bag-shaped heat-shrinkable film including the article to be packaged, and a heating means for heating the heat-shrinkable film, comprising a shrink packaging apparatus,
A shrink wrapping apparatus, wherein the heating means heats the entire heat-shrinkable film while relatively increasing the heating temperature of a corner formed at an end of the heat-shrinkable film. The main heating means for heating the entire heat shrinkable film,
Spot heating means for heating the outer corner of the heat-shrinkable film,
Follow-up means for following the spot heating means to the heat-shrinkable film transported by the transport means,
The shrink packaging device according to claim 1, further comprising: The shrink wrapping apparatus according to claim 2, wherein the follower moves an ejection port for ejecting hot air to the corner of the heat-shrinkable film together with the corner of the heat-shrinkable film. The said follower means forms a chamber which accumulates hot air inside the endless belt running in synchronization with the transport means, and forms the injection port in the endless belt. 4. The shrink packaging device according to 3. A regulation that injects hot air from the heating means to the heat-shrinkable film, and intercepts hot air from the heating means toward the periphery of the corner of the heat-shrinkable film between the heating means and the heat-shrinkable film. The shrink packaging apparatus according to claim 1, wherein a panel is arranged, and the regulation panel is moved in a direction in which the heat-shrinkable film is transported in synchronization with the transporting means. The shrink wrapping device according to claim 5, wherein the regulation panel is attached to an endless chain that runs in synchronization with the transporting means.

Images