JP7369510B2 - Sleeve packaging method using stretch film, stretch film for sleeve packaging, and manufacturing method of sleeve packaging body - Google Patents

Description

The present invention relates to a method for wrapping an article in a sleeve using a stretch film, a stretch film used in the method, and a method for producing a sleeve package using the method. The present invention can be particularly suitably used when packaging substantially rectangular parallelepiped articles such as comic books, hardcover books, and boxed products, or when packaging a plurality of them together.

BACKGROUND ART Books such as comic books and books are often wrapped in synthetic resin films to prevent browsing, contamination, and damage. Patent Document 1 is an invention relating to a packaging bag from which a sales slip sandwiched between books can be taken out without opening the bag. When a book is wrapped in a bag to prevent it from being opened, there is a problem in that it is not possible to remove the slip to confirm sales. Therefore, Patent Document 1 is characterized in that the packaging bag is provided with a hole through which the sales slip can be extracted.
However, when packaging books using pre-made packaging bags, it is difficult to mechanize the process of putting the books into the bag, so the opening of the packaging bag is usually opened manually and the books are placed inside the bag. I had to put in some kind of stuff.

Patent Document 2 is an invention related to a packaging device for shrink-wrapping books and the like. By using this device, the work of putting books into packaging bags, which was conventionally done manually, can be omitted and automated. Specifically, just by inserting books into the device through the insertion slot, the books can be automatically shrink-wrapped.
By the way, shrink packaging requires wrapping books in a shrink film and then passing the book through a heating device called a shrink tunnel to shrink the shrink film. However, since books are paper products, it is not desirable to install a heating device in a bookstore, and there is a desire for a packaging method that does not require a heating device.

Patent Document 3 is an invention related to a stretch film. The purpose is to eliminate the amount of carbon dioxide emitted during incineration, and it is characterized by containing a specific amount of carbon dioxide absorbing material.
Patent Document 3 discloses that the film can be used to package books and the like. However, no specific method for packaging books using this film is disclosed.

Patent Document 4 is an invention relating to a method for wrapping an object in a sleeve using a stretch film that is wider than the object to be packaged and has self-adhesive properties, and an apparatus for wrapping the object in a sleeve. The packaging method disclosed in Patent Document 4 involves wrapping a stretch film around an object to be packaged in at least two or more layers, then cutting the film and adhering the films to each other by self-shrinkage of the stretch film. In addition, the excess portion of the film protruding from the edge of the packaged object is shrink-adhered from the edge to the end surface in a sleeve-like manner.

This packaging method requires a large amount of packaging material because the film is wrapped at least twice. Furthermore, since the stretch film used in this packaging method has self-adhesive properties, it is difficult to stretch the stretch film while wrapping it around the item to be packaged, or to stretch the film after wrapping it around the item to be packaged. In Patent Document 4, a stretch film is stretched by 100% to 250% using a stretch roller in advance, and then the film is wrapped around an object to be packaged. Therefore, the equipment for covering the packaged items with the film was very special.

Utility Model Publication No. 7-11353 Utility model registration No. 3067592 Japanese Patent Application Publication No. 2016-11401 Japanese Patent Application Publication No. 10-305807

The present invention is a method for mechanically packaging objects such as books and boxed products, or objects made by stacking a plurality of these, and does not require a heating device such as a shrink tunnel. The objective is to provide a packaging method that can prevent contamination and damage to the packaged items. Another object of the present invention is to provide a stretch film used in the packaging method and a package using the packaging method.

As a means for solving the above problems, the present inventors first studied a method of wrapping an object with a band using a stretch film. As shown in FIG. 6(A), band wrapping is wrapping around the object 3' in a band shape using a synthetic resin film 2' whose width is narrower than the width X of the object 3'. It is a packaging method. At this time, the right side surface 3a' and left side surface 3b' of the packaged object 3' are not covered with the synthetic resin film 2'.
When books and boxed products were wrapped with a stretch film, it was found that the band wrapping could not sufficiently prevent contamination and damage of the books. The corners of these items to be packaged are most susceptible to damage, and in band wrapping, these corners cannot be protected with a film.

Therefore, the present inventors investigated a method of wrapping an object in a sleeve using a stretch film. As shown in FIG. 6(B), sleeve packaging is a packaging method in which a synthetic resin film 2' that is wider than the width X of the object 3' is used to cover the object 3'. According to sleeve packaging, the synthetic resin film 3' covers the front 31', back 32', upper surface 33', and lower surface 34' of the packaged object, and also covers the periphery of the right side 3a' and left side 3b' of the packaged object. is also covered.
In general sleeve packaging, a shrink film is used as the synthetic resin film 3'. This is to bring the side edges 2a', 2b' of the film into close contact with the left and right side surfaces 3a', 3b' of the packaged object. If the side edges 2a', 2b' of the film are raised from the left and right side surfaces 3a', 3b' of the packaged object, the appearance of the package will be poor and the film 2' will be easily torn from the raised parts.
The present inventors have discovered that when carrying out sleeve packaging using a stretch film, if the film is sufficiently stretched before forming the stretch film into a cylindrical shape, the side edges of the film will align with the left and right sides of the packaged object. They discovered that it can be bent, leading to the present invention.

That is, according to the present invention, as a means for solving the above problems, in a method of sleeve-wrapping an object to be packaged using a stretch film that is wider than the object to be packaged, both edges of the stretch film overlap both sides of the object to be packaged. a covering step of covering the object to be packaged with the stretch film so as to protrude from the sides; a stretching step of stretching the stretch film and folding the both side edges of the stretch film toward both side surfaces of the object to be packaged; There is provided a sleeve packaging method using a stretch film , which comprises sequentially a forming step of fusing and cutting the stretch film by fusing and sealing it to form a cylindrical shape.
Further, in a method of sleeve-wrapping a packaged item using a stretch film wider than the packaged item, the wrapped item is wrapped with the stretch film so that both side edges of the stretch film protrude from both sides of the packaged item. A stretching and covering step of stretching the stretch film while covering the object and folding the both side edges of the stretch film to both sides of the object to be packaged, and fusing and cutting the stretch film by fusing and sealing the stretch film. There is provided a sleeve packaging method using a stretch film, which comprises sequentially the following steps: , forming into a cylindrical shape.
Furthermore, the sleeve packaging method using the stretch film is characterized in that when stretching the stretch film in the stretching step or the stretch coating step, both side edges of the stretch film are stretched more than the center portion of the stretch film. provided.
Further, according to the present invention, there is provided a sleeve packaging method using the stretch film, wherein the object to be packaged is books.

Further, there is provided the sleeve packaging method, characterized in that the covering step or the stretch covering step includes covering the object to be packaged using one stretch film that is wider than the object to be packaged. .
In addition, raw stretch films are arranged above and below the object to be packaged, and the tip of the stretch film fed out from above and the tip of the stretch film fed out from below are connected by fusing and sealing. The sleeve packaging method is characterized in that the covering step or the stretch covering step covers the object to be packaged using a stretched stretch film.
Furthermore, there is provided a method for manufacturing a sleeve package comprising a stretch film and an object to be packaged, characterized in that the above-mentioned sleeve packaging method is used.

According to the packaging method of the present invention, books such as comic books and books, boxed products, and the like can be covered with a stretch film, including the corners. Therefore, there is no need for a heating device such as a shrink tunnel, and it is possible to effectively suppress contamination, damage, etc. of the packaged items. Further, according to the present invention, since the side edges of the stretch film are bent toward the packaged object, the resulting package has a good appearance, and the problem of the film being torn from the side edges is less likely to occur.
Furthermore, when the packaging method of the present invention is used for integrated packaging in which multiple items are packaged together, since both side edges of the stretch film are bent toward the packaged item, it is possible to suppress the individual items from shifting from side to side. A state of unity can be maintained.
When the object to be packaged is a book, browsing etc. can be prevented by employing the packaging method of the present invention. In addition, since the sleeve packaging is opened at the center of the left and right sides, the sales slip sandwiched between the books can be extracted without making holes in the film.

In particular, as a stretch film, no yield point is observed when the film is stretched by 50% (1.5 times the base length) in the machine direction (MD: the direction in which the film travels when manufacturing the film). When a film is used, the resulting package has a particularly good appearance .

1 is a schematic diagram for explaining the packaging method of the present invention. 1 is a schematic diagram for explaining the packaging method of the present invention. FIG. 2 is a schematic perspective view of a sleeve package produced by the manufacturing method of the present invention. 1 is a schematic diagram for explaining a specific embodiment of the present invention. 1 is a schematic diagram for explaining a specific embodiment of the present invention. It is a schematic perspective view for explaining band wrapping packaging (A) and sleeve packaging (B).

Hereinafter, the present invention will be explained in detail based on the drawings. In each figure, the same reference numerals represent the same or equivalent components. Further, the present invention is not limited to these forms, and can take various forms.
[Sleeve packaging method]
The sleeve packaging method using a stretch film of the present invention includes (1) a covering step, a stretching step, and a molding step in this order, or (2) a stretch coating step and a molding step in this order.

[(1) Packaging method comprising a coating step, a stretching step, and a forming step in this order]
Among the sleeve packaging methods of the present invention, a packaging method that includes a covering step, a stretching step, and a molding step in this order will be described based on FIG.
The covering step is a step of covering the object to be packaged with a stretch film. Specifically, as shown in FIG. 1(A), a film is bent by about 180 degrees, and an object to be packaged is placed between the folded films. Hereinafter, the direction perpendicular to the folded side of the film (direction W in Figure 1) will be referred to as the "width direction", and the direction parallel to the folded side (direction L in Figure 1) will be hereinafter referred to as the "length direction". .
In the covering step, the object to be packaged 3 is covered with the stretch film 2 so that both side edges 2a and 2b parallel to the length direction of the stretch film 2 protrude from the side edges 3c of the object to be packaged 3. At this time, the length direction L of the stretch film 2 and the side 3c of the article to be packaged 3 are made to be approximately parallel to each other. In FIG. 1, the side 3c substantially parallel to the length direction L of the stretch film is the short side of the object to be packaged, but the side 3c may be the long side of the object to be packaged. Which of the sides 3c should be used can be determined as appropriate depending on the size of the object to be packaged, the width of the film, the packaging machine, etc.

Next, a stretching process is performed. In the stretching process, as shown in FIG. 1(B), while stretching the stretch film 2 in the film length direction (in the direction of the arrow), the side edges 2a and 2b of the stretch film 2 are stretched along the sides 3a and 3a of the packaged object 3, respectively. Fold it to the 3b side. Usually, if the stretch film 2 is stretched approximately 1.1 to 1.5 times its length before stretching, the side edges 2a, 2b of the stretch film 2 will naturally bend toward the sides 3a, 3b of the packaged object 3. Note that when the side edges 2a, 2b of the stretch film are stretched more than the central portion 2c in the width direction, the side edges 2a, 2b tend to bend toward the packaged object 3 side.
As long as at least a portion of the side edges 2a and 2b of the stretch film 2 is bent toward the side surfaces 3a and 3b of the object to be packaged 3, there is no problem even if some unbent portion remains. , 2b is preferably bent at least 50%, particularly at least 70%, and even more preferably at least 90%. The more bent parts there are, the more effectively the packaged object can be protected, and the better the appearance of the package will be.

Next, a molding process is performed. The forming step is a step of fusing and cutting the stretch film to form it into a cylindrical shape as shown in FIG. 1(C). When the side edges 2a and 2b are bent toward the side surfaces 3a and 3b of the object to be packaged 3 in the stretching process, the stretch film 2 is formed into a cylindrical shape while maintaining the bent state. The method of fusing and cutting the film 2 is not particularly limited, but in consideration of the packaging finish, it is desirable to use fusing and sealing.

[(2) Packaging method comprising a stretch coating step and a forming step in this order]
Among the sleeve packaging methods of the present invention, a packaging method that includes a stretch coating step and a molding step in this order will be described based on FIG. 2. In FIG. 1, the object 3 to be packaged is covered with the stretch film 2 (covering step) and then the film 2 is stretched (stretching step). Also good (stretch coating process).
The stretch covering step is a step of covering the periphery of the packaged object 3 with the stretch film 2 while stretching the stretch film 2 in the length direction, as shown in FIG. 2(A). Although there is no particular limitation on the method of stretching the film and placing it around the object 3 to be packaged, it is desirable to temporarily fix the object 3 so that the position of the object 3 does not move. Further, similarly to the stretching process described above, when the side edges 2a, 2b of the stretch film are stretched more than the central portion 2c in the width direction, the side edges 2a, 2b tend to bend toward the packaged object 3 side.
The molding step (FIG. 2(B)) may be performed in the same manner as the molding step of the packaging method described above (1), which includes a covering step, a stretching step, and a molding step in this order.

[Sleeve packaging]
FIG. 3 is a schematic perspective view of the sleeve package 1 manufactured by the sleeve packaging method described above. A sleeve package 1 obtained according to the present invention consists of a stretch film 2 and a packaged object 3. When the width of the stretch film 2 is W (not shown) and the width of the packaged object 3 is X, W>X. If the film width W is less than or equal to the width of the object to be packaged, the object to be packaged 3 cannot be wrapped in a sleeve. Further, in order to reliably protect the corner portion 3d of the article to be packaged 3, it is desirable that the film width W is at least X+5 mm, particularly preferably at least X+10 mm.
Moreover, when the height of the packaged object 3 is Y, it is desirable that the film width W is (X+Y) or less. When the film width W exceeds X+Y, the stretch films 2 overlap on the right side 3a and/or left side 3b of the packaged object, deteriorating the appearance. When the packaged item 3 is books, the film width W is preferably (X+Y-5 mm) or less, particularly preferably (X+Y-10 mm) or less, in view of the work of removing sales slips.

[Stretch film]
The stretch film used in the sleeve packaging method of the present invention is stretched by 50% in the film flow direction (stretched until the distance between chucks becomes 1.5 times the original length) by the tensile test described below. It is desired that the film has no observed yield point. A film whose yield point is observed when stretched by 50% may undergo irreversible deformation during the above-mentioned stretching process or stretch coating process. Preferably, no yield point is observed even if the film is stretched 100% (distance between chucks is 2.0 times the original length).

Further, the stretch film used in the present invention desirably has a Young's modulus (tensile modulus) of 200 MPa or less in the film flow direction, which is determined from the tangent to the rising part of the stress-strain curve determined by the tensile test described below. , 150 MPa or less, particularly 100 MPa or less. A stretch film with a high Young's modulus is difficult to stretch, and the side edges of the stretch film are difficult to bend against the sides of the packaged object in the above-mentioned stretching process or stretch coating process. When the Young's modulus is less than 50 MPa, particularly less than 10 MPa, it becomes difficult to tightly wrap the object with the stretch film.

(Tensile test)
The tensile test method will be explained. First, a test piece type 4 specified in JIS K7127 is created. At this time, the flow direction of the film should be the length direction of the test piece. Next, in accordance with JIS K7161:2014, a tensile test is performed at a temperature of 23±2° C., a relative humidity of 50±5%, a distance between gauge lines of 40 mm, a distance between grips of 40 mm, and a tensile speed of 500 mm/min. In the examples of the present invention, Autograph AGS-X500N manufactured by Shimadzu Corporation was used for the tensile test.

In order to keep the values of yield point, Young's modulus, and 50% modulus within the above-mentioned ranges, it is preferable to form a film from polyurethane, for example. In addition, polyethylene resins such as low-density polyethylene, medium-density polyethylene, ultra-low-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, etc. One or more thermoplastic elastomers (β) such as polystyrene elastomer, polyolefin elastomer, polyurethane elastomer, polyester elastomer, polyamide elastomer, etc. are selected from α) as the main component. It is preferable to manufacture a stretch film from a resin composition which is selected and contains this as a subcomponent. In addition, considering the film formability and stretchability of the film, it is desirable to form a stretch film from a resin composition containing linear low-density polyethylene as the main component and adding an olefin elastomer as a subcomponent. . Furthermore, when a block copolymer of ethylene and α-olefin, which has excellent heat resistance, is used as the olefin-based elastomer, the stability of the sealed portion of the resulting film is improved.
The blending ratio of polyethylene resin (α) and thermoplastic elastomer (β) is not particularly limited, but for example, polyethylene resin (α): thermoplastic elastomer (β) = 51 to 95% by weight: 49 to 5 It is desirable that the amount is about 70 to 90% by weight: 30 to 10% by weight.

Further, it is desirable that the stretch film used in the present invention has a static friction coefficient of 0.1 to 0.9 on both surfaces. If the static friction coefficient exceeds 0.9, the stretch film may come into close contact with the packaged object or the conveyance machine, and may not be stretched uniformly in the above-mentioned stretch coating process. Furthermore, if the coefficient of static friction is less than 0.1, it becomes difficult to stack and store sleeve-wrapped packages. It is preferable that the inner surface (wrapping object side) of the stretch film has a coefficient of static friction of about 0.1 to 0.4, and the outer surface about 0.3 to 0.7.
In order to lower the coefficient of static friction without impairing the stretchability of the film, the stretch film is multi-layered, with the main component of both outer layers being a relatively dense polyethylene resin, and the main component of the other resin layer being a relatively dense polyethylene resin. It is sufficient to use a polyethylene resin with a low For example, the film may have a three-layer structure, with both outer layers molded from a resin composition containing linear low-density polyethylene as a main component with a density of 910 to 925 kg/m ³ , and an intermediate layer formed from a straight chain low density polyethylene with a density of 880 to 909 kg/m ³ . It is preferable to mold from a resin composition containing linear ultra-low density polyethylene as a main component.

Next, specific embodiments of the present invention will be described based on the drawings. 4 and 5 are diagrams sequentially showing steps of an embodiment of the present packaging method.
The stretch film 2 has a thickness of 40 μm and is made from a resin composition containing linear low-density polyethylene as a main component and an olefin elastomer, which is a block copolymer of ethylene and α-olefin, as a sub-component. Adopts stretch film (width 195mm). The yield point of the film was not observed when stretched 50%, and even when stretched 100%. Further, Young's modulus is 80 MPa.
A comic book with a width of 182 mm, a length of 128 mm, and a height of 20 mm is used as the packaged object.

The sleeve packaging method illustrated in FIG. 4 will be explained.
First, the article to be packaged 3 (comic book) is placed on the belt conveyor 5. At this time, the short side direction of the object to be packaged 3 is made to be approximately parallel to the moving direction of the belt conveyor 5. Next, the original rolls 4 of the stretch film 2 are placed above and below the object to be packaged 3, and the tip of the stretch film 2 fed out from above and the tip of the stretch film 2 fed out from below are fused and sealed. (Figure 4(A)). Furthermore, the belt conveyor 5 is rotated to push the packaged object 3 between the stretch films 2 (FIG. 4(B)). At this time, the original fabric 4 is set to be fed out with low tension. Once the stretch film 2 substantially covers the packaged object 3, the covering process is completed.

Next, the original fabric 4 is fixed so as not to rotate, and the object to be packaged 3 is further moved. At this time, in order to prevent the packaged product 3 from being pulled back by the stress of the stretch film 2, the lower rear part (the original fabric 4 side) of the packaged product 3 is pushed using the claw 6 (FIG. 4(C)). When the side edges 2a (2b) of the stretch film 2 are bent toward the object to be packaged 3, the stretch coating process is completed. At this time, if the side edges 2a (2b) of the stretch film are stretched larger than the widthwise center portion of the stretch film by pinching the side edges 2a (2b) with a jig or by placing a crown roll, etc. , the side edge portions 2a (2b) are easily bent toward the packaged object 3 side.

Finally, the stretch film 2 is fused and sealed using the heat seal bar 7a and the pedestal 7b, and the film is formed into a cylindrical shape, completing the forming process (FIG. 4(D)). Note that when the stretch film 2 expands and contracts during fusing and sealing, stress is applied to the sealing portion, which tends to cause sealing defects. In order to achieve a stable seal, it is preferable to suppress the front and back portions of the stretch film 2 to be melt-sealed with a restraining tool 8 prior to the melt-sealing, thereby suppressing expansion and contraction of the stretch film 2.
The sleeve package obtained according to this embodiment has a stretch film covering all corners of the comic book to be packaged, so that the comic book can be efficiently protected. Also, since both edges of the stretch film are bent toward the sides of the comic book, the appearance is good.

Next, the sleeve packaging method illustrated in FIG. 5 will be explained.
First, the article to be packaged 3 (comic book) is placed on the belt conveyor 5. At this time, the short side direction of the comic book is made to be approximately parallel to the moving direction of the belt conveyor 5. Next, the original fabric 4 of the stretch film 2 is placed above and below the object to be packaged 3, and the tip of the stretch film 2 fed out from above and the tip of the stretch film 2 fed out from below are connected ( Figure 5(A)). Next, the article to be packaged 3 is pushed out between the stretch films 2 by pressure 9 (FIG. 5(B)). At this time, the original fabric 4 is set to be fed out with high tension, so that the stretch film 2 is fed out while being stretched. When the side edges 2a (2b) of the stretch film 2 are bent toward the object to be packaged 3, the stretch coating process of the present invention is completed. Similar to the embodiment illustrated in FIG. 4, when the side edge portions 2a (2b) of the stretch film are stretched more than the widthwise center portion of the stretch film, the side edge portions 2a (2b) are directed toward the packaged object 3 side. Easy to bend.

Next, while retracting the pressure 9, the stretch film 2 is held between the restrainers 8 to prevent the stretch film 2 from returning to its original state (non-stretched state) (FIG. 5(C)). Finally, the packaging method of the present invention is completed by fusing and sealing the film 2 using the heat seal bar 7a and the pedestal 7b and forming it into a cylindrical shape (FIG. 5(D)).

1 Packaging body 2 Stretch film 2' Synthetic resin film 2a, 2a' Right edge 2b, 2b' Left edge 3, 3' Item to be packaged 3a, 3a' Right side 3b, 3b' Left side 3c Side edge 3d Corner 31' Front 32' Back 33' Upper surface 34' Lower surface 4 Original fabric 5 Belt conveyor 6 Claw 7a Heat seal bar 7b Receiver 8 Holder 9 Pressure

Claims (4)

In a method of sleeve-wrapping an object to be packaged , such as books, boxed products, or a substantially rectangular parallelepiped object, using a stretch film wider than the object to be packaged,
a conveyance step of placing the object to be packaged on a belt conveyor and conveying the object to be packaged in a horizontal direction;
disposing stretch film originals above and below the packaged object, and connecting the tip of the stretch film fed out from above and the tip of the stretch film fed out from below by fusing and sealing;
A coating that covers the upper and lower surfaces of the packaged item with the stretch film so that the packaged item is pushed out between the stretch films during the conveyance process , and both side edges of the stretch film protrude from both sides of the packaged item. process and
a stretching step of stretching the stretch film disposed on the upper and lower surfaces of the object to be packaged in the length direction, thereby bending the both side edges of the stretch film toward both side surfaces of the object to be packaged;
A forming step in which the stretch film placed on the upper and lower surfaces of the packaged object is sandwiched between restrainers, stretched in the length direction, and fused and sealed to fuse and cut to form a cylindrical shape. ,
A sleeve packaging method using a stretch film, characterized by sequentially comprising: In a method of sleeve-wrapping an object to be packaged , such as books, boxed products, or a substantially rectangular parallelepiped object, using a stretch film wider than the object to be packaged,
a conveyance step of placing the object to be packaged on a belt conveyor and conveying the object to be packaged in a horizontal direction;
disposing stretch film originals above and below the packaged object, and connecting the tip of the stretch film fed out from above and the tip of the stretch film fed out from below by fusing and sealing;
The object to be packaged is pushed out between the stretch films by the conveyance step, and the upper and lower surfaces of the object to be packaged are covered with the stretch film so that both side edges of the stretch film protrude from both sides of the object to be packaged. , a stretch coating step of stretching the stretch film disposed on the upper and lower surfaces of the object to be packaged in the length direction, thereby folding the both side edges of the stretch film toward both side surfaces of the object to be packaged;
A forming step in which the stretch film placed on the upper and lower surfaces of the packaged object is sandwiched between restrainers, stretched in the length direction, and fused and sealed to fuse and cut to form a cylindrical shape. ,
A sleeve packaging method using a stretch film, characterized by sequentially comprising: Using the stretch film according to claim 1 or 2, wherein when stretching the stretch film in the stretching step or the stretch coating step, both side edges of the stretch film are stretched more than the center portion of the stretch film. Sleeve packaging method. A method for producing a sleeve package comprising a stretch film and an object to be packaged, the method comprising using the sleeve package method according to any one of claims 1 to 3 .

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