Shrink-wrapped items

Abstract

To provide a shrink package article having a hexagonal shape provided with perforations serving as a film easy break line in a form of not breaking on heating and in a form of easily being broken when taking out an article.SOLUTION: A shrink film 20 on a rectangular one face of a hexagonal article is provided, along a virtual straight line 53 traversing the one face, with a film easy break line 54 by a perforation 52 formed by perforation forming means 15 provided in a shrink package device 10. A unit perforation 52a constituting the film easy break line 54 is formed only at a part on one short side on the rectangular one face, preferably at a region M of length of about 30%, as a part of the virtual straight line 53 in continuity at 6 to 15 points at intervals S of 3.0 to 6.5 mm with a length L of 0.5 to 1.0 mm.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a shrink-wrapped article having a hexahedral shape formed using a shrink-wrapping device.

Background Art

[0002] Conventionally, as a packaged article obtained by packaging various articles such as cup noodles, a shrink-wrapped article packaged using a shrink film, which is a synthetic resin film having heat shrinkability, is known. The shrink-wrapped article is obtained by forming a shrink film provided with pinholes on the film surface into a cylindrical shape, then accommodating an article inside the formed cylindrical shrink film, and sealing both end portions, and heating the article accommodation bag obtained thereby by passing it through a heating portion to shrink the shrink film, thereby packaging the article with the shrink film adhered to the surface. Various packaging devices for forming such shrink-wrapped articles have been developed (for example, see Patent Document 1).

[0003] In the shrink-wrapping device described in Patent Document 1, an article supply unit for supplying an article, a film supply unit for supplying a shrink film, an article accommodation unit for accommodating an article in a bag made of the shrink film to form an article accommodation bag, a heating unit for heating the formed article accommodation bag, etc. are provided. When passing the article accommodation bag through the heating unit, the shrink film is heated, and by the synergistic action of the shrinkage of the shrink film and the air inside the article accommodation bag being once heated and expanded and then discharged from the pinholes, a shrink-wrapped article in which the article is packaged with the shrink film adhered to the surface can be obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] On the other hand, with the diversification of sales methods for goods in recent years, there is consideration being given to shrink-wrapping and distributing / selling items with a hexahedral shape, such as booklets formed by laminating multiple sheets of printed paper with a rectangular planar shape to a predetermined thickness, using shrink film.

[0006] Furthermore, when shrink-wrapping an article with a hexahedral shape, the heat-shrunk shrink film will adhere tightly to all six sides of the hexahedral article. Therefore, it is expected that removing the shrink film and taking out the article from the shrink-wrapped hexahedral article will require considerable effort. For this reason, it is conceivable to make it easier to remove the article by providing an easy-tear line, such as a perforation, on one of the sides of the hexahedral shape of the shrink film covering the hexahedral article.

[0007] However, when a perforated line for easy tearing is provided on one of the sides of a hexahedral-shaped shrink film covering a hexahedral-shaped article, the perforations must be formed in the shrink film prior to heating in the heating section. Depending on the form of the formed perforations, when the air inside the article-containing bag is heated and expands, the perforated line for easy tearing may break. Furthermore, when removing the shrink film from the shrink-wrapped article to take out the article, it may become difficult to find or break the perforated line. Therefore, there is a need to solve these technical problems specific to hexahedral-shaped shrink-wrapped articles.

[0008] The present invention aims to provide a shrink-wrapped article having a hexahedral shape, in which perforations that serve as easy-tear lines are provided on one of the surfaces of the hexahedral shape of the shrink film covering the article, in a manner that prevents tearing when heated but allows for easy tearing when removing the article, thereby maintaining a stable packaging form during distribution and sales, while allowing for easy removal of the article when in use. [Means for solving the problem]

[0009] The present invention achieves the above objective by providing a shrink-packaged article having a hexahedral shape, formed by covering an article having a hexahedral shape with shrink film using a shrink packaging device, wherein a film breakage line is provided along a virtual straight line that crosses the rectangular face of the shrink film on the hexahedral shape, formed by a perforation forming means provided on the shrink packaging device, and the unit perforations constituting the film breakage line are arranged in a series of 5 to 22 locations with a length of 0.5 to 1.5 mm and intervals of 1.0 to 7.0 mm, and are formed only on a portion of the virtual straight line.

[0010] Furthermore, it is preferable that the shrink-wrapped article of the present invention has unit perforations constituting the film's easy-tear line arranged in a series of 6 to 15 locations with a length of 0.5 to 1.0 mm and at intervals of 3.0 to 6.5 mm, and is formed only on a portion of the imaginary straight line.

[0011] Furthermore, it is preferable that the shrink-wrapped article of the present invention comprises an article supply unit for supplying the article having the hexahedral shape, a film supply unit for supplying a heat-shrinkable shrink film, an article storage unit for storing the article in a storage unit made of shrink film to form an article storage bag before heat shrinking, and a heating unit for shrink-wrapping the stored article by heating the formed article storage bag to heat-shrink the shrink film.

[0012] Furthermore, it is preferable that the shrink-wrapped article of the present invention has a pair of markings indicating the direction of separation on both sides of the film break line on the shrink film on the side where the film break line is formed by perforations.

[0013] Furthermore, it is preferable that the shrink-wrapped article of the present invention has a pair of markings indicating the direction of separation, which are arrow markings.

[0014] Furthermore, in the shrink-wrapped article of the present invention, it is preferable that the perforations that allow the film to break easily are formed only on a portion of the imaginary straight line that extends parallel to the long side direction of one rectangular surface.

[0015] Furthermore, it is preferable that the perforations in the shrink-wrapped article of the present invention form the film break-off line only on a portion of the imaginary straight line that crosses the center of the width in the short-side direction of one rectangular surface.

[0016] Furthermore, in the shrink-wrapped article of the present invention, it is preferable that the unit perforations constituting the film break-off line are formed as a part of the imaginary straight line, in an area of ​​50% or less of the straight line that crosses one rectangular surface.

[0017] Furthermore, in the shrink-wrapped article of the present invention, it is preferable that the unit perforations constituting the film break-off line are formed only on one short side of the rectangular surface, as part of the imaginary straight line.

[0018] Furthermore, it is preferable that the shrink-wrapped article of the present invention is a booklet formed by laminating a plurality of printed sheets having a rectangular planar shape to a predetermined thickness, in which case the article having the hexahedral shape is a booklet. [Effects of the Invention]

[0019] According to the shrink-wrapped article of the present invention, on any one of the six faces of the hexahedral article covered by the shrink film, a perforation that becomes an easily breakable line of the film is provided in a form that does not break during heating and can be easily broken when the article is taken out. Thus, a stable packaging form can be maintained during distribution and sales, and the article can be easily taken out during use.

Brief Description of the Drawings

[0020] [Figure 1] (a) is a schematic perspective view showing a shrink film-wrapped article according to a preferred embodiment of the present invention, (b) is a front view of the shrink film-wrapped article, and (c) is an enlarged schematic view of part A in (b). [Figure 2] It is a schematic side view for explaining the configuration of a shrink packaging device that forms a shrink film-wrapped article according to a preferred embodiment of the present invention. [Figure 3] It is an enlarged view of part B of FIG. 2 for explaining the situation where a perforation is formed in the shrink film by a perforation forming device. [[ID='15']] [Figure 4] (a) is a front view illustrating a round knife, and (b) is a cross-sectional view taken along line C-C of (a). [Figure 5] It is an enlarged schematic side view for explaining the first heating tunnel that constitutes the heating part. [Figure 6] It is an enlarged schematic side view for explaining the second heating tunnel that constitutes the heating part. [Figure 7] It is an enlarged schematic side view for explaining the article supply part.

Modes for Carrying Out the Invention

[0021] The shrink-wrapped article 50 shown in Figures 1(a) and 1(b) according to a preferred embodiment of the present invention is a hexahedral-shaped packaged article formed by laminating a booklet 50', which preferably has a rectangular planar shape, to a predetermined thickness, and then covering it with a shrink film 20 using the shrink-wrapping device 10 shown in Figure 2. In this embodiment, the shrink-wrapped article 50 has perforations 52, which serve as film break-off lines 54, on one side of the booklet 50', which is a hexahedral-shaped article, in a manner that prevents breakage during heating, but allows for easy breakage when removing the booklet 50', thus maintaining a stable packaging form during distribution and sales, and allowing for easy removal of the article during use.

[0022] Furthermore, the shrink-wrapped article 50 of this embodiment is a hexahedral-shaped packaged article formed by covering a booklet 50', which is a hexahedral-shaped article, with shrink film 20 using a shrink-wrapping device 10. As shown in Figures 1(a) and (b), a film break line 54 is provided on one rectangular surface of the shrink film 20 of the hexahedral shape, along a virtual straight line 53 that crosses that surface, formed by a perforation forming device 15, which is a perforation forming means 15 provided on the shrink-wrapping device 10 (see Figure 2), with perforations 52. The unit perforations 52a constituting the film break line 54 are arranged in 5 to 22 locations with a length of 0.5 to 1.5 mm and intervals of 1.0 to 7.0 mm, and are formed as a part of the virtual straight line 53, for example, on one short side of one rectangular surface, preferably in an area of ​​50% or less, and only in a length region M of about 30%. In this embodiment, the length region M has, for example, an overall length of approximately 42.5 mm, and its central portion is located 50 mm from the lower short side.

[0023] Furthermore, in the shrink-wrapped article 50 of this embodiment, a pair of markings 55 indicating the direction of separation are preferably drawn on both sides of the film break line 54 on one rectangular surface of the shrink film 20 where the film break line 54 formed by the perforations 52 is located.

[0024] In this embodiment, the article 50' having a hexahedral shape, which is covered with shrink film 20 to become a shrink-packaged article 50, is, as described above, a booklet 50' formed by laminating a plurality of printed sheets, preferably having a rectangular planar shape, to a predetermined thickness. The booklet 50' is, for example, a soft cover, such as a comic book or a paperback. The shrink-packaged article 50, which is made by packaging the soft cover booklet 50', is formed to have a flattened hexahedral shape, having a rectangular planar shape with dimensions of, for example, a vertical width of about 120 to 200 mm and a horizontal width of about 100 to 130 mm, and a thickness of about 5.5 to 50 mm. The soft cover booklet 50' passes through the heating section 14, which consists of the first heating tunnel 25 and the second heating tunnel 26, that constitute the shrink packaging device 10 described later, so that it does not bend or curve in an arc shape, but maintains its hexahedral shape firmly, and is neatly shrink-packaged in a desirable appearance.

[0025] Furthermore, in this embodiment, the shrink film 20 on one rectangular surface (preferably the top surface) of the hexahedral shrink-wrapped article 50 is provided with a film break line 54 formed by perforations 52 along a virtual straight line 53 that crosses that surface. From the viewpoint of making it easier to place the fingers of both hands on either side of the perforations 52 when removing the booklet 50', which is the article, from the shrink-wrapped article 50, it is preferable that the film break line 54 formed by perforations 54 is formed only on a portion of the virtual straight line 53 that extends parallel to the long side direction of the rectangular surface, and more preferably on a portion of the virtual straight line 53 that crosses the center of the width (horizontal width) in the short side direction of the rectangular surface.

[0026] Furthermore, in this embodiment, the film break-resistant line 54 is formed by having unit perforations 52a of the perforations 52 constituting the film break-resistant line 54 arranged in 5 to 22 locations with a length L of 0.5 to 1.5 mm and an interval S of 1.0 to 7.0 mm, preferably as part of a virtual straight line 53 parallel to the long side direction that crosses the center in the width direction, and is formed, for example, only in a length region M of preferably 50% or less on one short side of one rectangular surface. More preferably, for example, it is formed by having 6 to 15 locations with a length L of 0.5 to 1.0 mm and an interval S of 3.0 to 6.5 mm, and is formed only in a length region M of about 30% on one short side.

[0027] As a result, when the article-containing bag 51, before the shrink film 20 is heated and shrunk, passes through the heating section 14 of the shrink packaging device 10, particularly the second heating tunnel 26, the heated air inside the bag expands, but the unit perforations 52a constituting the perforations 52 are arranged in a series with an appropriate length L and an appropriate interval S, and are formed only in a portion of an appropriate length region M as part of a virtual straight line 53. Therefore, it is possible to effectively avoid rupture due to internal pressure caused by the expansion of air. Furthermore, as a result, when removing the shrink film 20 from the shrink-wrapped hexahedral shrink-wrapped article 50 to take out the booklet 50', the unit perforations 52a that make up the perforations 52 are formed along a virtual straight line 53 with an appropriate length L and an appropriate interval S, so the film break line 54 is not difficult to find or break, and it can be broken with a simple operation, for example, by placing the fingers of both hands on either side of the perforations 52 and pulling them apart. Moreover, the remaining part can be easily broken using the film break line 54 formed by 52 as a starting point, and the shrink film 20 can be removed, making it possible to easily and smoothly take out the booklet 50'.

[0028] Therefore, according to the shrink-wrapped article 50 of this embodiment formed by the shrink-wrap device 10, perforations 52, which serve as film break-off lines 54, are provided on one of the hexahedral surfaces of the shrink film 20 covering the booklet 50', which is a hexahedral article. These perforations 52 are provided in a manner that prevents breakage during heating, but allows for easy breakage when removing the article 50'. This ensures that a stable packaging form is maintained during distribution and sales, and that the article 50' can be easily removed during use.

[0029] Furthermore, in the shrink-wrapped article 50 of this embodiment, as described above, a pair of markings 55, preferably arrows, are drawn on both sides of the film break line 54 on one rectangular surface of the shrink film 20 where the film break line 54 formed by the perforations 52 is located, to indicate the direction of separation. This makes it easy to identify the area on one rectangular surface of the shrink film 20 where the film break line 54 formed by the perforations 52 is located, and the clear indication of the direction of separation makes it possible to break the film break line 54 more smoothly. The markings 55 indicating the direction of separation of the film break line 54 can be arrows or other various marks that indicate different separation directions.

[0030] Figure 2 illustrates a preferred shrink packaging apparatus 10 for forming the shrink-wrapped article 50 of this embodiment. The shrink packaging apparatus 10 shown in Figure 2 includes an article supply unit 11 for supplying a booklet 50' before packaging, which is an article having a hexahedral shape; a film supply unit 12 for supplying a heat-shrinkable shrink film 20; an article storage unit 13 for accommodating the booklet 50' in a storage unit made of shrink film 20 to form an article storage bag 51 before heat shrinking; and a heating unit 14 for shrink-wrapping the booklet 50' to form a shrink-film-packaged article 50 by heating the formed article storage bag 51 and causing the shrink film 20 to heat shrink.

[0031] Furthermore, the shrink packaging apparatus 10 is equipped with a perforation forming device 15 in the film supply section 12, which forms perforations 52 (see Figure 1) along the supply direction of the shrink film 20, thereby providing an easy-tear line 54 on one side of the hexahedral shrink-packaged article 50 after shrink packaging. As shown in Figures 3 and 4(a) and (b), the perforation forming device 15 includes a disc-shaped round knife 16 equipped with a plurality of protruding cutter blades 16a arranged at intervals in the circumferential direction. The round knife 16 is provided with a plurality of protruding cutter blades 16a arranged in a continuous manner only in a portion of the circumferential direction, such that a plurality of unit perforations 52a constituting the perforation 52 are formed in a continuous manner at intervals of 1.0 to 7.0 mm and 0.5 to 1.5 mm in length, at 5 to 22 locations, more preferably in a continuous manner at intervals of 3.0 to 6.5 mm and 0.5 to 15 locations (see Figure 4(a)).

[0032] Furthermore, in this embodiment, the round knife 16 of the perforation forming device 15 is configured to form perforations 52 with multiple protruding cutter blades 16a while rotating with the shrink film 20 sandwiched between it and the rotating roller 17 around which the shrink film 20 is wound (see Figure 3).

[0033] Furthermore, in this embodiment, the perforation forming apparatus 15 is configured to include a reciprocating mechanism 18 that moves the round knife 16 forward and backward relative to the rotating roller 17.

[0034] In this embodiment, the shrink packaging device 10 has the same configuration as the shrink packaging device described in Patent Document 1, except that, for example, it is provided with a perforation forming device 15, the heating unit 14 is equipped with a first heating tunnel 25 and a second heating tunnel 26 as described later, and the article supply unit 11 supplies booklets 50'.

[0035] In other words, the shrink packaging apparatus 10 of this embodiment includes, as described above, an article supply unit 11, a film supply unit 12, an article storage unit 13, and a heating unit 14, as well as a moving means 19 consisting of a supply conveyor 19a, a feed conveyor 19b, and a discharge conveyor 19c, an automatic defective product removal device 21, an operation panel 22, a scrap winding device, and the like.

[0036] As shown in Figure 7, the item supply unit 11 is composed of a booklet hopper unit 11a capable of stacking and holding multiple hexahedral booklets 50' that are fed in, and an extrusion piston 11c positioned below the booklet hopper unit 11a so as to be able to move back and forth and push out the bottommost booklet 50' one by one to the gripping and conveying unit 11b. The booklets 50' pushed out by the extrusion piston 11c are then gripped between the endlessly rotating upper pressing belt 11d and lower pressing belt 11e of the gripping and conveying unit 11b and sequentially sent to the supply conveyor 19a (see Figure 2) of the moving means 19.

[0037] As shown in Figure 2, the film supply unit 12 is composed of a film holder 12a formed by winding multiple layers of shrink film 20 around a rotating shaft, and a plurality of guide rollers 12b that guide the shrink film 20, which is continuously drawn out in a strip from the film holder 12a, toward the article storage unit 13. A known film splicer 12c, a perforation forming device 15 (described later), and a known pinhole forming device (not shown) are arranged in the middle of the supply path provided by the guide rollers 12b that constitute the film supply unit 12.

[0038] The article storage section 13 is a known structure that includes a sealing section 13a, a side sealing section 13b, a horizontal sealing section 13c, etc. The sealing section 13a is the part that encloses the booklet 50', which is a hexahedral article, inside the shrink film 20 that is continuously supplied in a strip from the film supply section 12, while folding it back in the width direction. The shrink film 20 that encloses the booklet 50' in the sealing section 13a is sealed at the folded open side by the side sealing section 13b on the downstream side in the supply direction, forming a cylindrical shape containing the booklet 50', and after being sent to the supply conveyor 19b, the horizontal sealing section 13c further seals both the front and rear ends in the supply direction that sandwich the contained booklet 50'. This creates an article storage bag 51 before heat shrinkage, in which the booklet 50' is sealed and stored in the bag-shaped storage section made of the shrink film 20. The formed article storage bag 51 is then fed via the discharge conveyor 19c to the heating section 14, which consists of the first heating tunnel 25 and the second heating tunnel 26 on the downstream side in the supply direction.

[0039] In this embodiment, a perforation forming device 15 is provided in the film supply unit 12 to form perforations 52 along the supply direction of the shrink film 20, thereby providing a film break-off line 54 on one side of the hexahedral shrink-packaged article 50 after shrink packaging (see Figure 4). As shown in an enlarged view in Figure 3, the perforation forming device 15 includes a rotating shaft box 15a to which a round knife 16 is attached, a sliding support column 15b that supports the rotating shaft box 15a so that it can slide up and down, and a rotating roller 17 that is supported by the sliding support column 15b and positioned directly below the rotating shaft box 15a.

[0040] A rotating shaft box 15a has a rotating shaft 15c mounted at its lower part, to which a removable round knife 16 is fixed in a predetermined axial position, in a rotatably supported manner. Inside the rotating shaft box 15a, a rotational drive mechanism 15e is provided for rotationally driving the rotating shaft 15c via a rotating belt 15d, and the rotational speed can be controlled by operating the control panel 22 (see Figure 2). A sliding mechanism 18 is integrally mounted on the upper part of the rotating shaft box 15a, extending toward the sliding column 15b side, and functioning as a reciprocating mechanism 18 that moves the round knife 16 fixed to the rotating shaft 15c forward and backward relative to the rotating roller 17, and is slidable vertically along the sliding column 15b. The sliding mechanism 18 can be automatically controlled by operating the control panel 22 to intermittently move the round knife 16 up and down at predetermined timings.

[0041] In this embodiment, the round knife 16 fixed to the rotating shaft 15c is a plate-like member having a disc shape made of metal or synthetic resin, as shown in Figures 4(a) and (b). The round knife 16 has a disc shape with a diameter of approximately φ50 mm, and a circular fixing opening 16c is formed in the central part, with an inner diameter of approximately φ15 mm and a locking notch 16b cut out on the outside for fixing the round knife 16 to the rotating shaft 15c in a non-rotatable manner. The round knife 16 has multiple protruding cutter blades 16a arranged in a continuous manner in the circumferential direction, for example in a region of approximately 120° in the circumferential direction, with a circumferential arc length L' of approximately 0.5 to 1.5 mm and a circumferential arc spacing S' of approximately 1.0 to 7.0 mm, protruding at 5 to 22 locations, preferably with a protrusion height of approximately 2 mm. More preferably, the blades are provided in a continuous configuration in the circumferential direction, with a circumferential arc length L' of about 0.5 to 1.0 mm and a circumferential arc spacing S' of about 3.0 to 6.5 mm, protruding at 6 to 15 locations, preferably with a projection height of about 2 mm. In addition, the circumferential arc length M' of the connected tips of the multiple protruding cutter blades 16a is preferably about 41 to 50 mm.

[0042] In this embodiment, the round knife 16 rotates while sandwiching the shrink film 20 being fed between it and the rotating roller 17 around which the shrink film 20 is wound. As the round knife 16 rotates, a plurality of protruding cutter blades 16a sequentially and intermittently form perforations 52 by a single row of unit perforations 52a at intervals of 1.0 to 7.0 mm and on a virtual straight line in the feeding direction of the shrink film 20, at intervals of 1.0 to 7.0 mm and 5 to 22 locations in a row. In this embodiment, more specifically, for example, perforations 52 by a single row of unit perforations 52a formed at intervals of 1 mm and 21 locations, preferably at a predetermined pitch corresponding to the length of the booklet 50' in the feeding direction.

[0043] In this embodiment, the perforation forming device 15 is provided with an encoder unit 24 supported at the lower end of the slide support portion 15b. The encoder unit 24 is positioned to contact the guide roller 12b adjacent to the downstream side of the rotating roller 17 in the feeding direction, with the feed-out shrink film 20 sandwiched between them, so as to detect the movement speed of the feed-out shrink film 20 and to feed back the detected movement speed to the control panel 22. This makes it possible to accurately and intermittently form a group of unit perforations 52a at a predetermined pitch at predetermined positions on the shrink film 20 supplied toward the article storage section 13.

[0044] The shrink film 20, on which perforations 52 formed by a group of unit perforations 52a at a predetermined pitch with precision and intermittence by the perforation forming device 15, is guided by a plurality of guide rollers 12b of the film supply unit 12, as described above, and after pinholes are further formed at appropriate positions by a pinhole forming device (not shown), it is supplied to the article storage unit 13. The shrink film 20 with perforations 52 that has been supplied to the article storage unit 13 is controlled by operation on the control panel 22, and the intermittently formed perforations 52 are precisely positioned at predetermined positions, for example, on the top surface of each booklet 50', which is a hexahedral-shaped article, supplied sequentially from the article supply unit 11, and as described above, the shrink film 20 is folded back by the holster unit 13a to sequentially wrap the fed-out hexahedral-shaped booklets 50'. The shrink film 20 encasing the booklet 50' is formed into a cylindrical shape containing the booklet 50' by the side sealer portion 13b on the downstream side in the supply direction, as described above. Then, the ends on both the front and rear sides in the supply direction that sandwich the booklet 50' are sealed and cut by the lateral sealer portion 13c, thereby forming the article storage bag 51 before heat shrinking. The formed article storage bag 51 is then sent via the discharge conveyor 19c to the heating section 14 for heat shrinking the shrink film 20, as described above.

[0045] In this embodiment, the heating section 14 for heat-shrinking the shrink film 20 covering the booklet 50' in the formed article storage bag 51 is configured, as shown in Figure 2, to include a first heating tunnel 25 located on the upstream side in the delivery direction and a second heating tunnel 26 located on the downstream side in the delivery direction. As also shown in Figure 5, the first heating tunnel 25 is equipped with an upper pressing belt 25b that moves up and down relative to the conveyor belt 25a, moving the article storage bag 51 being conveyed between it and the conveyor belt 25a while covering and sandwiching its upper and lower surfaces.

[0046] In other words, in this embodiment, the first heating tunnel 25 is configured to include a lower conveyor device 25d that endlessly rotates a conveyor belt 25a using a conveyor motor 25c, and a pressing belt device 25f that endlessly rotates an upper pressing belt 25b using an upper pressing belt motor 25e. The pressing belt device 25f includes a belt support frame 25h having a rectangular frame shape on which a plurality of guide rollers 25g that guide the rotational movement of the upper pressing belt 25b are arranged, and a frame lifting device 25i that is integrally attached to the belt support frame 25h and slides the belt support frame 25h up and down along a support member (not shown) erected adjacent to the lower conveyor device 25d. The raising and lowering of the frame lifting device 25i causes the upper pressing belt 25b, which is supported by the belt support frame 25h and can rotate endlessly, to move up and down relative to the conveyor belt 25a of the lower conveyor device 25d, thereby allowing the item storage bag 51 being transported between the conveyor belt 25a to be moved while being covered and sandwiched between the upper and lower surfaces. In addition to the lower conveyor device 25d and the pressing belt device 25f, the first heating tunnel 25 is also equipped with a heater 25j for heating the inside of the tunnel and a fan motor 25k for circulating hot air.

[0047] These features allow the first heating tunnel 25 to pre-heat and shrink the shrink film 20 covering the outer periphery of the booklet 50', which is the article in the article storage bag 51, before sending the article storage bag 51 to the second heating tunnel 26.

[0048] On the other hand, the second heating tunnel 26 is configured to move the article storage bag 51 while heating it with a conveyor belt 26a, with the top surface of the article storage bag 51 open. Similar to conventional heating tunnels, it is equipped with a conveyor device 26d having a conveyor belt 26a and a conveyor motor 26c for transporting the article storage bag 51, as well as a heater 26j for heating the inside of the tunnel, a fan motor 26k for circulating hot air, and the like.

[0049] In this embodiment of the shrink wrapping apparatus 10, the shrink film 20 covering the outer surface of the booklet 50', which is the article in the article storage bag 51, is heated and shrunk first in the first heating tunnel 25. Then, in the second heating tunnel 26, the remaining portion of the shrink film 20 covering the booklet 50' is heated and shrunk to shrink the booklet 50', thereby forming a shrink-film-wrapped article 50. This makes it possible to easily shrink-wrap a booklet 50', which is the article to be shrink-wrapped, while maintaining its hexahedral shape, even if the booklet 50' has a flexible soft cover, such as a comic book or a paperback.

[0050] In other words, if the booklet 50' being shrink-wrapped is, for example, a comic book or a paperback with a flexible soft cover, then with a conventional heating tunnel, the printed edges of the booklet 50' on the side opposite the binding edge are open. As a result, the compressive force from the contraction of the storage bag makes it easy for the cross-sectional shape perpendicular to the binding edge to curve and warp into an arc shape. Therefore, it becomes difficult to shrink-wrap the booklet while maintaining its hexahedral shape.

[0051] In contrast, in this embodiment, the shrink film 20 covering the outer periphery of the booklet 50' is first heated and shrunk in the first heating tunnel 25, and then the remaining portion is heated and shrunk in the second heating tunnel 26. This makes it possible to pre-determine the shape of the outer periphery of the booklet 50', where the edges of the printed paper are open, by pressing it down with the pre-heated and shrunk shrink film 20 while sandwiching the upper and lower surfaces, thereby effectively preventing the cross-sectional shape perpendicular to the binding margin from becoming curved and warped due to the compressive force caused by the shrinkage of the storage bag when the entire shrink film 20 is heated and shrunk. Furthermore, this makes it possible to easily shrink-package a booklet 50', formed by laminating multiple printed sheets to a predetermined thickness, while maintaining its hexahedral shape.

[0052] Therefore, with the shrink packaging apparatus 10 having the above configuration, it becomes possible to easily form perforations 52, which serve as film break-off lines 54, on any of the hexahedral shrink film packaging articles 50 of this embodiment covered with shrink film 20, in a manner that prevents breakage during heating, while also making it easy to break when removing the booklet 50' which is the article.

[0053] Furthermore, in this embodiment, the shrink packaging apparatus 10 is provided with a known printing device (not shown) controlled by the operation of the control panel 22, downstream of the second heating tunnel 26 of the heating section 14. As described above, this printing device can draw a pair of markings 55 (see Figures 1(a) and (b)) on both sides of the film breakage line 54 of the shrink film 20 on one side of the shrink packaged article 50, preferably consisting of arrows, to indicate the direction in which the film breakage line 54 can be separated.

[0054] It should be noted that the present invention is not limited to the embodiments described above and can be modified in various ways. For example, the shrink-wrapped article of the present invention does not necessarily have to be a booklet 50', but may be any other article having a different hexahedral shape, such as a hexahedral package containing software media, CDs, or DVDs. [Explanation of Symbols]

[0055] 10 Shrink packaging device 11 Goods Supply Department 11a Booklet hopper section 11b Clamping and conveying section 11c Extrusion Piston 11d Upper retaining belt 11e Lower pressure belt 12 Film supply unit 12a Film holder 12b Guide roller 12c Film Sprinkler 13. Storage Section for Goods 13a Home Club 13b Side seal section 13c Yokoshira section 14 Heating section 15 Perforation forming means (perforation forming apparatus) 16 Round Knife 16a Protruding cutter blade 17 Rotating Rollers 18. Retraction mechanism (slide mechanism) 19. Means of Transportation 19a Supply conveyor 19b Feed conveyor 19c discharge conveyor 20 Shrink film 21 Defective product automatic exclusion device 22 Control panel 23. Scrap winding device 24 encoder units 25. First heated tunnel 26. Second heated tunnel 50 Shrink film packaged items 50' Booklet (a hexahedron-shaped object) 51. Item storage bag 52 perforations 52a Unit perforation 53. A virtual straight line 54. Film prone to breakage. 55 Marking

Claims

1. A shrink-wrapped article having a hexahedral shape is formed by covering a soft-cover booklet, which is made by laminating multiple printed sheets of paper having a rectangular planar shape to a predetermined thickness, with shrink film using a shrink-wrapping device equipped with a first heating tunnel and a second heating tunnel. The shrink film covering the outer edge of the softcover booklet is heat-shrunk first in the first heating tunnel, and the remaining shrink film is heat-shrunk later in the second heating tunnel. A shrink-wrapped article having a perforated film breakage line formed by a perforation forming means provided on the shrink-wrapping device along a hypothetical straight line that crosses either the front or back surface of the shrink-wrapped booklet, wherein the unit perforations constituting the film breakage line are arranged in a series of 5 to 22 locations with a length of 0.5 to 1.5 mm and intervals of 1.0 to 7.0 mm, and are formed only on a portion of the hypothetical straight line.

2. The shrink-wrapped article according to claim 1, wherein the unit perforations constituting the film break-off line are arranged in a series of 6 to 15 locations with a length of 0.5 to 1.0 mm and at intervals of 3.0 to 6.5 mm, and are formed only on a portion of the imaginary straight line.

3. The shrink-wrapped article according to claim 1 or 2, wherein a pair of markings indicating the direction of separation are depicted on both sides of the film's tear-off line on one side of the shrink film where the tear-off line is formed by perforations.

4. The shrink-wrapped article according to claim 3, wherein the pair of markings indicating the direction of separation are arrow markings.

5. The shrink-wrapped article according to claim 1 or 2, wherein the perforation line for easy tearing of the film is formed only on a portion of the imaginary straight line extending parallel to the long side direction of one of the surfaces.

6. The shrink-wrapped article according to claim 5, wherein the perforation line for easy tearing of the film is formed only on a portion of the imaginary straight line that crosses the center of the width in the short-side direction of one of the surfaces.

7. The shrink-wrapped article according to claim 1 or 2, wherein the unit perforations constituting the film break-off line are formed as part of the imaginary straight line and are formed only in an area of ​​50% or less of the straight line that crosses one of the surfaces.

8. The shrink-wrapped article according to claim 1 or 2, wherein the unit perforations constituting the film break-off line are formed as part of the imaginary straight line, and only on one short side of one of the surfaces.

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