Shrink packaging apparatus and shrink packaging method

Abstract

To provide a shrink packaging device and a shrink packaging method capable of easily shrink-packaging a booklet formed by laminating a plurality of printed sheets to a predetermined thickness while retaining a hexahedral shape.SOLUTION: The shrink packaging device is constituted so that a heating section 14 includes a first heating tunnel 25 arranged on the upstream side in a sending direction, and a second heating tunnel 26 arranged on the downstream side in the sending direction, wherein in the first heating tunnel 25, a shrink film 20 covering an outer peripheral surface of a booklet 50' which is an article in an article storage bag 51 is heated and contracted in advance, and then in the second heating tunnel 26, the remaining part of the shrink film 20 covering the article storage bag 51 is heated and contracted to shrink-package the booklet 50' which is the article.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a shrink packaging device and a shrink packaging method for shrink packaging a booklet, which is an article having a hexahedral shape, with a shrink film having heat shrinkability.

Background Art

[0002] Conventionally, as a packaging form for packaging various articles such as cup noodles, shrink packaging using a shrink film, which is a film of a synthetic resin having heat shrinkability, is known. Shrink packaging is obtained by forming a shrink film provided with pinholes on the film surface into a cylindrical shape, accommodating an article inside, and then sealing and cutting both ends to obtain an article accommodation bag, and heating the article accommodation bag by passing it through a heating unit to shrink the shrink film, thereby packaging the article with the shrink film closely attached to the surface. Various packaging devices for performing such shrink packaging have been developed (for example, see Patent Document 1).

[0003] The shrink packaging device described in Patent Document 1 includes an article supply unit for supplying an article, a film supply unit for supplying a shrink film, an article accommodation unit for accommodating the article in a bag formed by the shrink film to form an article accommodation bag, a heating unit for heating the formed article accommodation bag, etc. When passing the article accommodation bag through the heating unit, the shrink film is heated, and due to the synergistic effect of the shrinkage of the shrink film and the air inside the article accommodation bag once expanding by heating and then being discharged from the pinholes, a shrink packaged article in which the shrink film is closely attached to the surface is 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 has been consideration of shrink-wrapping items with a hexahedral shape, such as booklets formed by laminating multiple printed sheets of paper with a rectangular planar shape to a predetermined thickness, using shrink film.

[0006] However, when shrink-wrapping a booklet formed by laminating multiple printed sheets to a predetermined thickness using conventional shrink-wrapping equipment, especially if the booklet has a flexible soft cover, such as a comic book or paperback, or if it has no cover, even if it has a box-shaped appendix, when the item storage bag containing the booklet passes through the heating section and the shrink film contracts, the edges of the printed sheets on the side of the booklet opposite the binding margin are left open. As a result, the compressive force from the contraction of the bag makes it easy for the cross-sectional shape perpendicular to the binding margin to curve and warp into an arc shape. This makes it difficult to shrink-wrap the booklet while maintaining its hexahedral shape, and therefore there is a need to solve the specific technical challenges in equipment and methods for shrink-wrapping such hexahedral booklets.

[0007] The present invention aims to provide a shrink-wrapping apparatus and shrink-wrapping method that can easily shrink-wrap a booklet formed by laminating multiple printed sheets to a predetermined thickness while maintaining its hexahedral shape. [Means for solving the problem]

[0008] The present invention relates to a shrink packaging apparatus comprising: an article supply unit for supplying articles having a hexahedral shape; a film supply unit for supplying heat-shrinkable shrink film; an article storage unit for storing the articles in a storage unit made of shrink film to form an article storage bag before heat shrinking; and a heating unit for shrink packaging the stored articles by heating the formed article storage bag to heat shrink the shrink film, wherein the articles having a hexahedral shape are booklets formed by laminating a plurality of printed sheets having a rectangular planar shape to a predetermined thickness, and the heating unit is configured to include a first heating tunnel located on the upstream side in the dispensing direction and a second heating tunnel located on the downstream side in the dispensing direction, and the first The above objective is achieved by providing a shrink packaging device in which the heating tunnel moves up and down relative to the conveyor belt, and is equipped with an upper pressing belt that moves the article storage bag being conveyed between the conveyor belt and the heating tunnel while covering and sandwiching the upper and lower surfaces of the bag, the heating tunnel moves the article storage bag by the conveyor belt with the upper surface of the article storage bag open, and in the first heating tunnel the shrink film covering the outer peripheral side surface of the booklet in the article storage bag is heated and shrunk first, and then the remaining portion of the shrink film covering the article storage bag is heated and shrunk in the second heating tunnel to shrink the booklet.

[0009] Furthermore, the shrink packaging apparatus of the present invention is provided in the film supply section with a perforation forming device for forming perforations along the supply direction of the shrink film, thereby providing a film tear-off line on one side of the hexahedral booklet after shrink packaging. The perforation forming device includes a disc-shaped round knife equipped with a plurality of protruding cutter blades spaced apart in the circumferential direction. Preferably, the round knife has a plurality of protruding cutter blades arranged in a continuous manner only in a portion of the circumferential direction, such that a plurality of unit perforations constituting the dimples are formed in a continuous manner at 6 to 15 locations with a length of 0.5 to 1.0 mm and spacing of 3.0 to 6.5 mm, only in a portion of a hypothetical straight line crossing one side of the booklet.

[0010] Furthermore, it is preferable that the shrink packaging apparatus of the present invention is configured such that the round knife of the perforation forming apparatus forms the perforations with a plurality of protruding cutter blades while rotating with the shrink film sandwiched between the round knife and a rotating roller that winds and guides the shrink film in the supply direction.

[0011] Furthermore, it is preferable that the shrink packaging apparatus of the present invention includes a reciprocating mechanism that moves the round knife forward and backward relative to the rotating roller.

[0012] Furthermore, the present invention provides a shrink packaging apparatus comprising: an article supply unit for supplying an article having a 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 packaging the stored article by heating the formed article storage bag to heat shrink the shrink film, wherein the article having a hexahedral shape is a booklet formed by laminating a plurality of printed sheets having a rectangular planar shape to a predetermined thickness, and the present invention achieves the above objective by providing a shrink packaging method in which, when heating the article storage bag containing the booklet in the heating unit to heat shrink the shrink film, the shrink film covering the outer peripheral side of the booklet in the article storage bag is heated and shrunk first, and then the remaining portion of the shrink film covering the booklet is heated and shrunk to shrink the booklet. [Effects of the Invention]

[0013] According to the shrink packaging apparatus or shrink packaging method of the present invention, a booklet formed by laminating multiple printed sheets of paper to a predetermined thickness can be easily shrink packaged while maintaining its hexahedral shape. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic side view illustrating the configuration of a shrink packaging apparatus according to a preferred embodiment of the present invention. [Figure 2] This is an enlarged view of part A in Figure 1, illustrating the process of forming perforations in shrink film using a perforation forming device. [Figure 3] (a) is a front view illustrating a round knife, and (b) is a cross-sectional view of (a) along line BB. [Figure 4] (a) is a schematic perspective view showing a shrink-film packaged article formed by a shrink-wrapping device, (b) is a front view of the shrink-film packaged article, and (c) is a schematic enlarged view of section C in (b). [Figure 5] This is an enlarged schematic side view illustrating the first heating tunnel that constitutes the heating section. [Figure 6] This is an enlarged schematic side view illustrating the second heating tunnel that constitutes the heating section. [Figure 7] This is an enlarged schematic side view illustrating the goods supply section. [Modes for carrying out the invention]

[0015] The shrink-wrapping apparatus 10 shown in Figure 1, according to a preferred embodiment of the present invention, is used as an apparatus for forming a hexahedral shrink-film-wrapped article 50 (see Figure 4) by covering a booklet 50', which is formed by laminating a plurality of printed sheets having a rectangular planar shape to a predetermined thickness, with a shrink-wrapping film 20. The shrink-wrapping apparatus 10 of this embodiment has the function of easily shrink-wrapping a booklet 50' with a flexible cover, such as a comic book or a paperback, which is formed by laminating a plurality of printed sheets to a predetermined thickness, while maintaining its hexahedral shape.

[0016] The shrink packaging apparatus 10 of this embodiment comprises an article supply unit 11 for supplying articles having a hexahedral shape, a film supply unit 12 for supplying heat-shrinkable shrink film 20, an article storage unit 13 for storing articles 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-packaging the stored articles by heating the formed article storage bag 51 to heat-shrink the shrink film 20, thereby shrink-packaging the stored articles to form a shrink-film-packaged article 50, wherein the article having a hexahedral shape is a booklet 50' formed by laminating a plurality of printed sheets having a rectangular planar shape to a predetermined thickness (see Figure 4). The heating unit 14 is configured 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 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, and moves the article storage bag 51 being conveyed between it and the conveyor belt 25a while covering and sandwiching its upper and lower surfaces. As shown in Figure 6, the second heating tunnel 26 moves the article storage bag 51 by the conveyor belt 26a with the top surface of the article storage bag 51 open. In the first heating tunnel 25, the shrink film 20 covering the outer periphery of the booklet 50', which is the article in the article storage bag 51, is heated and shrunk first, and 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'.

[0017] Also, in the present embodiment, preferably, a perforation forming device 15 is disposed in the film supply unit 12 to form perforations 52 (see FIG. 4) along the supply direction of the shrink film 20, so as to provide a film easily breakable line 54 on one surface of the hexahedral booklet 50' after shrink packaging. As shown in FIGS. 2, 3(a), and 3(b), the perforation forming device 15 includes a disk-shaped round knife 16 having a plurality of protruding cutter blades 16a arranged at intervals in the circumferential direction. On the round knife 16, a plurality of unit perforations 52a constituting the perforations 52 are continuously formed at 6 to 15 locations with a length L of 0.5 to 1.0 mm and a spacing S of 3.0 to 6.5 mm only on a portion of a virtual straight line 53 (see FIG. 4) that crosses one surface of the shrink packaged article 50. The plurality of protruding cutter blades 16a are continuously provided only on a portion in the circumferential direction (see FIG. 3(a)).

[0018] Furthermore, in the present embodiment, the round knife 16 of the perforation forming device 15 is configured to form the perforations 52 with the plurality of protruding cutter blades 16a while rotating in a state where the shrink film 20 is sandwiched between the round knife 16 and a rotating roller 17 that winds and guides the shrink film 20 in the supply direction (see FIG. 2).

[0019] Moreover, in the present embodiment, the perforation forming device 15 includes an advancing and retreating mechanism 18 that advances and retreats the round knife 16 with respect to the rotating roller 17.

[0020] In the present embodiment, the shrink packaging device 10 has the same configuration as the shrink packaging device described in Patent Document 1 above, except that, for example, the perforation forming device 15 is provided, the heating unit 14 includes a first heating tunnel 25 and a second heating tunnel 26 as described later, and the article supply unit 11 supplies the booklet 50'.

[0021] 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.

[0022] As shown in Figure 7, the item supply unit 11 is configured to include 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 capable of pushing 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 1) of the moving means 19.

[0023] As shown in Figure 1, 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.

[0024] 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.

[0025] In this embodiment, a perforation forming device 15 is preferably provided in the film supply unit 12 for forming 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). The perforation forming device 15, as shown in an enlarged view in Figure 2, comprises 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 as to be able to 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.

[0026] 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 1). 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.

[0027] 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 3(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.

[0028] In this embodiment, the round knife 16 rotates with the shrink film 20 being fed in between the rotating roller 17 on which the shrink film 20 is wound, and a plurality of protruding cutter blades 16a sequentially and intermittently form perforations 52 by a group of unit perforations 52a in a row, for example, with a length L of 0.5 to 1.5 mm and an interval S of 1.0 to 7.0 mm, on a virtual straight line in the feeding direction of the shrink film 20 being fed out, at a predetermined pitch between perforations 52. More specifically in this embodiment, perforations 52 by a group of unit perforations 52a in a row, formed at 21 locations with a length of 1 mm and an interval of 1 mm, are sequentially and intermittently formed at a predetermined pitch that preferably corresponds to the length of the booklet 50' in the feeding direction.

[0029] 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.

[0030] 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.

[0031] In this embodiment, the heating section 14 for heat-shrinking the shrink film 20 that covers the booklet 50' in the formed article storage bag 51 is configured as described above, and includes 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 (see Figure 1). 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, and moves the article storage bag 51 being conveyed between it and the conveyor belt 25a while covering and sandwiching its upper and lower surfaces.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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 first heated and shrunk 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.

[0036] In other words, according to this embodiment, the shrink packaging apparatus 10 comprises an article supply unit 11 for supplying a booklet 50' 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 storing 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 packaging the stored booklet 50' by heating the formed article storage bag 51 to heat shrink the shrink film 20. The shrink packaging apparatus 10 provides a method for shrink packaging a booklet 50' which is an article having a hexahedral shape, wherein in the heating unit 14, when heating the article storage bag 51 containing the booklet 50' to heat shrink the shrink film 20, the shrink film 20 covering the outer periphery of the booklet 50' in the article storage bag 51 is heated and shrunk first, and then the remaining portion of the shrink film 20 covering the booklet 50' is heated and shrunk in this shrink packaging method.

[0037] As a result, according to the shrink-wrapping device 10 or shrink-wrapping method of this embodiment, even if the booklet 50' to be shrink-wrapped is a booklet with a flexible soft cover, such as a comic book or a paperback, it is possible to easily shrink-wrap such a booklet 50', which is formed by laminating multiple sheets of printed paper to a predetermined thickness, while maintaining its hexahedral shape.

[0038] Here, if the booklet 50' being shrink-wrapped is, for example, a comic book or a paperback, which has a flexible soft cover, or has no cover at all, even if it has, for example, a box-shaped appendix, in the case of a conventional heating tunnel, the printed edges of the booklet 50' on the side opposite the binding margin are open, and the compressive force due to the contraction of the storage bag makes it easy for the cross-sectional shape perpendicular to the binding margin to curve and warp into an arc shape, and therefore it becomes difficult to shrink-wrap the booklet while maintaining its hexahedral shape.

[0039] 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.

[0040] In this embodiment, a hexahedral shrink-packaged article 50, which is formed by a shrink-packaging device 10 having the above-described configuration, for example, by covering a booklet 50' with shrink film 20, is provided with a film break line 54 formed by perforations 52, which are formed by the perforation forming device 15 described above, along a virtual straight line 53 that crosses one rectangular surface of the shrink film 20 on that surface, as shown in Figures 4(a) and (b). The film break line 54 is formed by unit perforations 52a of the perforations 52 that constitute the film break line 54, which are preferably arranged in 6 to 15 locations with a length L of about 0.5 to 1.0 mm and an interval S of about 3.0 to 6.5 mm, as a part of the virtual straight line 53, for example, only in a length region M of preferably about 30% of one short side of one rectangular surface. 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.

[0041] 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.

[0042] 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 comic book or a paperback, with a soft cover. The shrink-packaged article 50, which is made by packaging the soft-cover booklet 50', is formed to have a flattened hexahedral shape with a rectangular planar shape having a vertical width of approximately 120 to 200 mm and a horizontal width of approximately 100 to 130 mm, and a thickness of approximately 5.5 to 50 mm. By passing through the heating section 14 by the first heating tunnel 25 and the second heating tunnel 26 described above, it is not curved or warped into an arc shape, but maintains its hexahedral shape firmly, and is neatly shrink-packaged in a desirable appearance.

[0043] 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.

[0044] Furthermore, in this embodiment, the film breakage line 54 is formed by having unit perforations 52a of the perforations 52 constituting the film breakage line 54, preferably with a length L of about 0.5 to 1.0 mm and spaced apart at intervals S of about 3.0 to 6.5 mm in 6 to 15 locations, and preferably as part of a virtual straight line 53 parallel to the long side direction that crosses the center in the width direction, for example, only in a region M of preferably about 30% of the length on one short side of one rectangular surface. As a result, when the article storage bag 51 before the shrink film 20 is heated and shrunk passes through the heating section 14, particularly the second heating tunnel 26, even if the air inside the heated bag expands, the unit perforations 52a constituting the perforations 52 are arranged in a manner of appropriate length L and spaced apart at appropriate intervals S, and are formed only in a part of the virtual straight line 53, so 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'.

[0045] Therefore, with the shrink-wrapped article 50 formed by the shrink-wrap device 10 of this embodiment, 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.

[0046] Furthermore, according to the shrink packaging apparatus 10 of this embodiment, it becomes possible to easily form perforations 52, which serve as film break-off lines 54, on any of the hexahedral surfaces of the shrink film packaging article 50 covered by the 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.

[0047] 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 4(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 pulled away or separated. The markings 55 indicating the direction in which the film breakage line 54 can be pulled away or separated can be arrows or other various other marks that indicate different separation directions.

[0048] 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, it is not necessarily required that one side of the hexahedral booklet formed by the shrink packaging apparatus of the present invention has perforations for easy film tearing. The shrink packaging method of the present invention can also be carried out by a shrink packaging apparatus that includes heating sections other than those including the first heating tunnel and the second heating tunnel 26. [Explanation of symbols]

[0049] 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 device 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 machine 24 encoder units 25. First heated tunnel 26. Second heated tunnel 50 Shrink film packaged items 50' booklet 51. Item storage bag 52 perforations 52a Unit perforation 53. A virtual straight line 54. Film prone to breakage.

Claims

1. A shrink packaging apparatus comprising: an article supply unit for supplying articles having a hexahedral shape; a film supply unit for supplying heat-shrinkable shrink film; an article storage unit for storing the articles in a storage unit made of shrink film to form an article storage bag before heat shrinking; and a heating unit for shrink-packaging the stored articles by heating the formed article storage bag to heat-shrink the shrink film, wherein The article having the hexahedron shape is a booklet formed by laminating multiple printed sheets having a rectangular planar shape to a predetermined thickness. The film supply unit is equipped with a perforation forming device for forming perforations along the supply direction of the shrink film, thereby providing an easy-tear line on one side of the hexahedral booklet after shrink packaging. The perforation forming apparatus includes a disc-shaped round knife equipped with a plurality of protruding cutter blades arranged at intervals in the circumferential direction, wherein the plurality of protruding cutter blades are arranged in a continuous manner only in a portion of the circumferential direction on a hypothetical straight line that crosses one side of the booklet, and the plurality of unit perforations constituting the perforation are formed in a continuous manner at intervals of 3.0 to 6.5 mm and 6 to 15 locations with a length of 0.5 to 1.0 mm, and the heating section is configured to include a first heating tunnel located on the upstream side in the feeding direction and a second heating tunnel located on the downstream side in the feeding direction. The first heating tunnel is equipped with an upper pressing belt that moves up and down relative to the conveyor belt, and moves the article storage bag being conveyed between it and the conveyor belt while covering and sandwiching its upper and lower surfaces. The second heating tunnel is configured to move the article storage bag by a conveyor belt with the top surface of the article storage bag open. A shrink packaging apparatus comprising the first heating tunnel, which first heats and shrinks the shrink film covering the outer surface of the article in the article storage bag, and then the second heating tunnel, which heats and shrinks the remaining portion of the shrink film covering the booklet to shrink the booklet.

2. The shrink packaging apparatus according to claim 1, wherein the round knife of the perforation forming apparatus is configured to form the perforations with a plurality of protruding cutter blades while rotating with the shrink film sandwiched between the round knife and a rotating roller that winds and guides the shrink film in the supply direction.

3. The shrink packaging apparatus according to claim 2, which includes a reciprocating mechanism for moving the round knife back and forth relative to the rotating roller.

Images