JP2005035649A - Packaging method using corona discharge process, packaging device, and package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To join, with sufficient joining strength, parts of packaging film even if the packaging film is antistatic film, to allow printing on the joint, and to ensure appropriate packaging. <P>SOLUTION: The packaging method includes: the step of covering an item 40 to be packaged, with the packaging film 41; and the step of overlapping and joining parts of the packaging film 41. Before the covering step, the surface of the packaging film 41 is activated by being processed with corona discharge. In the joining step, the parts of the packaging film 41 processed with the corona discharge are blocked together. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for suitably carrying out packaging having a part in which parts of a packaging film such as a so-called center seal are bonded to each other.

  As an example of a conventional packaging method, there is a method of packaging an object to be packaged using a pillow packaging machine (see, for example, Patent Document 1). In this packaging method, first, a long strip of packaging film is formed into a cylindrical shape by a former of a pillow packaging machine, and a plurality of packaging objects are sequentially supplied into the cylindrical packaging film. . At the lower part of the former, a center sealer is used to bond the side edges of the packaging film. At a stage subsequent to the former, a pair of fusing sealers are used to cut and seal the packaging film at a position between the objects to be packaged. As a result, a package in which the entire packaging object is wrapped with the bag-shaped packaging film is obtained. Thereafter, when the packaging film of the packaging body is heated and shrunk, an overshrink packaging body having a form in which the packaging film is substantially in close contact with the outer surface of the packaging object is obtained.

As a method of adhering both side edges of the packaging film with the center sealer, there are a heat seal method in which those portions are heated and heat-sealed, or an electrostatic seal method in which those portions are charged and adhered. In the past, the actual situation was that these sealing methods were used.
Japanese Patent Laid-Open No. 2002-337941 (FIG. 7)

  However, in the conventional heat sealing method, when printing is performed on the heat sealing target portion, there is a problem that the adhesiveness is inferior or the printing portion is damaged by heat. More specifically, as shown in FIG. 7, in the heat sealing method, for example, a pair of heating rollers 80 are used to sandwich the side edges 9a and 9b of the film 9, and the sealing portion is a so-called joint-pasting. It becomes. In this case, if the printing is performed on the inner surfaces of the pair of side edge portions 9a and 9b that are in contact with each other, the adhesiveness is inferior. On the contrary, if printing is performed on the outer surfaces of the pair of side edge portions 9a and 9b, the printing ink is damaged by heat, and the printing appearance is greatly impaired. For this reason, when the heat seal method is used, it is necessary to avoid printing the heat seal target portion as much as possible. However, in recent years, there is often a strong demand for displaying a product name on a packaging film or printing a decorative design in a large area. In order to meet such a demand, there is a case where it is desired to perform printing on a portion to be bonded of the packaging film.

  On the other hand, the electrostatic sealing method can be applied only when the packaging film can be charged. If the packaging film has been subjected to antistatic treatment, this electrostatic sealing method should be applied. I can't. On the other hand, if the packaging film is not subjected to antistatic treatment so that the electrostatic sealing method can be applied, the packaging film is charged with static electricity. As a result, the packaging operation cannot be performed smoothly. Moreover, the packaging body obtained by using the packaging film is likely to be dusty and electrostatically adhered to the surface, and the commercial value is greatly impaired.

  The present invention has been conceived under such circumstances, and even if the packaging film has been subjected to antistatic treatment, a part of the packaging film is bonded with sufficient adhesive strength. The challenge is to enable it to be printed on the adhesive part and to enable appropriate packaging.

  In order to solve the above problems, the present invention takes the following technical means.

  The packaging method provided by the first aspect of the present invention includes a covering step of covering an object to be packaged with a packaging film, and an adhesion step of overlapping and bonding a part of the packaging film. In the preceding stage of the coating step, the packaging film is subjected to corona discharge treatment to activate its surface, and in the bonding step, the corona discharge of the packaging film is performed. It is characterized in that the portions subjected to the discharge treatment are blocked.

  The corona discharge treatment technology itself used in the present invention is known from the past, and when a film with poor surface activity is printed or an adhesive is applied, this treatment is performed in advance to activate the film surface. It is used for the purpose of enhancing the hydrophilicity by making it possible to suitably perform printing and adhesive application. In contrast, the present invention uses the corona discharge treatment used for such a purpose as a treatment for adhering a part of the packaging film, and the adhering is performed using a blocking phenomenon. This is based on a new idea that has never been seen before, and has the following effects.

  According to the present invention, unlike the heat sealing method, since there is no need to heat the packaging film, even if printing is performed on the bonding target portion of the packaging film, the printed portion is damaged by heat. I will not receive it. When the part on which the packaging film is printed is used as the adhesion target area, the corona discharge treatment is applied to the surface opposite to the printing surface of the packaging film, thereby treating the corona discharge treatment on the packaging film. It is possible to appropriately block the other portions to which the coating is applied, and the adhesive strength by this blocking can be made quite strong so that it can sufficiently withstand practical use. Although specific numerical values will be described later, this has been confirmed by the tests of the present inventors. Further, depending on the type of printing ink, it is possible to block other portions of the packaging film by applying a corona discharge treatment to the printing surface. As described above, according to the present invention, it is possible to appropriately print and display the adhesive film while adhering parts of the packaging film with sufficient adhesive strength, and is suitable for improving the decorativeness of the package. It becomes.

  Further, according to the present invention, unlike the electrostatic sealing method, when the antistatic treatment is applied to the packaging film, there is no difficulty in adhering parts of the packaging film. . Therefore, as the packaging film, a film that has been subjected to antistatic treatment is used, and the packaging film is charged with static electricity, causing trouble in the packaging operation, and dust and the like are likely to adhere to the packaging body. Problems such as significant loss of merchandise value can also be resolved.

  The packaging device provided by the second aspect of the present invention includes a former in which both side edge portions of a belt-like packaging film are overlapped to form a cylinder, and a plurality of packaging apparatuses formed in the cylinder-shaped packaging film. A packaging device comprising: a supply means for sequentially supplying the packaging objects; and a cutting means for cutting the packaging film at a position between the plurality of packaging objects. A corona discharge treatment device is provided that performs corona discharge treatment on both side edges before the side edges are overlaid.

  According to the packaging apparatus having such a configuration, the packaging method provided by the first aspect of the present invention can be appropriately implemented, and the same effect as described above can be obtained.

  In a preferred embodiment of the present invention, a cover body surrounding a portion where the corona discharge treatment is performed by the corona discharge treatment apparatus, and ozone generated by the corona discharge treatment are decomposed outside or inside the cover body. And an ozonolysis apparatus for processing. According to such a configuration, it is possible to appropriately prevent the surrounding environment from deteriorating due to the ozone generated with the corona discharge treatment.

  The packaging body provided by the third aspect of the present invention is a packaging body in which a packaging object is covered with a packaging film, and a part of the packaging film is overlapped and bonded. Adhesion between parts of the packaging film is characterized in that the surfaces activated by the corona discharge treatment are blocked.

  According to such a configuration, an effect similar to that described for the packaging method provided by the first aspect of the present invention can be obtained, printing on the adhesive portion between the packaging films can be performed, and packaging It is also possible to use an antistatic treatment film.

  Other features and advantages of the present invention will become more apparent from the following description of the embodiments of the invention.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  FIG. 1 shows an example of a packaging device according to the present invention. The packaging device A of this embodiment includes a pillow packaging machine 1, a heating tunnel 2, and a corona discharge treatment device 3.

  The pillow wrapping machine 1 has a basic structure similar to that of a conventionally known pillow wrapping machine, and is a former 10 that forms a long strip-shaped packaging film 41 fed out from a take-up roll R into a cylindrical shape. The supply conveyor 11 that transports the packaging object 40 so that the plurality of packaging objects 40 are put into the cylindrical packaging film 41 from the front end opening of the former 10 at regular intervals, and the packaging film 41 includes a plurality of packaging objects. A pair of fusing sealers 12 for fusing and sealing between the objects 40 and a discharge conveyor 13 provided at the subsequent stage of the pair of fusing sealers 12 are provided.

  However, the pillow wrapping machine 1 is provided with a receiving plate 14 for pressing a wrapping film and a pressing roller 15 as an alternative to the center sealer provided in a general pillow wrapping machine. The receiving plate 14 has a substantially flat plate shape, is fixedly attached to the former 10, or is formed integrally with the former 10. The pressing roller 15 is urged upward by a spring (not shown) or the like so that a later-described portion of the packaging film 41 can be clamped between the pressing roller 15 and the receiving plate 14. The heating tunnel 2 is configured to be able to heat the packaging body 4 obtained by fusing and sealing the packaging film 41 with a pair of fusing sealers 12, and has a heater for heating or a hot air blowing port. .

  The corona discharge treatment device 3 is provided in the middle of the supply path of the packaging film 41 from the take-up roll R to the former 10, and the surface for guiding the packaging film 41 has two rollers made of metal. 30a, 30b, and two electrodes 31a, 31b facing each other. These are connected to a high-frequency power source (not shown), and corona discharge is possible between them.

  As clearly shown in FIG. 2, the electrode 31 a is disposed below a portion near one end of the roller 30 a and faces the downward surface 42 a of the packaging film 41 with a space therebetween. Therefore, according to the electrode 31a and the roller 30a, the portion on one side 42a of the one side edge portion 41a of the packaging film 41 is exposed to the corona discharge atmosphere, and only this portion is activated. It becomes the discharge treatment region 43A. On the other hand, the electrode 31b is arranged above the roller 30b so as to be located on the opposite side of the packaging film 41 in the width direction from the electrode 31a. For this reason, according to the electrode 31b and the roller 30b, only the part by the side of the upward surface 42b in the figure among the other side edge parts 41b of the packaging film 41 becomes the corona discharge processing area | region 43B.

  The two corona discharge treatment regions 43A and 43B of the packaging film 41 are formed when the packaging film 41 is formed in a cylindrical shape and the side edges 41a and 41b are overlapped with each other, as shown in phantom lines in FIG. It is an area that faces each other. As shown in the figure, the packaging film 41 is provided with a printed layer 46 on which printing has been performed (however, this printed layer 46 is shown only in FIGS. 3 and 4 and other drawings). Are omitted). The printed layer 46 is formed on substantially the entire area of the one surface 42a of the packaging film 41 excluding the corona discharge treatment area 43A of the one side edge 41a. In the other side edge portion 41b of the packaging film 41, the printed layer 46 is formed on one surface 42a, and the opposite surface 42b is a corona discharge treatment region 43B.

  A region where the corona discharge treatment of the corona discharge treatment apparatus 3 is performed is surrounded by a cover body 32. The cover body 32 is for suppressing the ozone generated by the corona discharge treatment from diffusing around the corona discharge treatment apparatus 3, and is substantially box-shaped. The ozone in the cover body 32 is led from the exhaust port 32a to an ozone decomposition treatment device 39 through an appropriate duct so as to be decomposed. As a method for decomposing ozone, there are a catalyst decomposing method for decomposing by contacting ozone with a catalyst, and a heat decomposing method for decomposing by heating to high temperature. As a specific example of the former, there is a method in which ozone is adsorbed on a powder catalyst of nickel oxide and decomposed. As a specific example of the latter, there is a method in which ozone is guided and decomposed on a metal surface such as stainless steel maintained at a high temperature. The ozonolysis treatment apparatus 39 employs at least one decomposition method among such decomposition methods. When the ozonolysis treatment device 39 is manufactured in a small size, the ozonolysis treatment device 39 may be directly connected to the exhaust port 32a of the cover body 32 or may be provided inside the cover body 32. . Further, when the amount of generated ozone is small, the ozone decomposition treatment device 39 may not be provided, and for example, the ozone in the cover body 32 may be simply guided to an appropriate location via a duct.

  Next, an example of the packaging method according to the present invention using the packaging apparatus A having the above configuration will be described.

  First, in the process of transporting the packaging film 41 fed from the winding roll R, the packaging film 41 is subjected to corona discharge treatment using the corona discharge treatment device 3. Thereby, as described with reference to FIGS. 2 and 3, the predetermined portions of the side edges 41a and 41b of the packaging film 41 are defined as the activated corona discharge treatment regions 43A and 43B. Although ozone is generated during the corona discharge treatment, the ozone is prevented from diffusing to the periphery by the cover body 32 and the exhaust duct, and is guided to the ozone decomposition treatment device 39 and decomposed as necessary. The surrounding environment of the device A can be maintained in a good state.

  Next, the packaging film 41 having been subjected to the corona discharge treatment is formed into a cylindrical shape by the former 10 and a roller (not shown), and a plurality of packaging objects 40 conveyed by the supply conveyor 11 are inserted therein at regular intervals. I will let you. The packaging object 40 in the present embodiment is a cup-shaped container in which, for example, instant noodles or instant noodles are hermetically housed. When the packaging film 41 is formed into a cylindrical shape, as shown in FIG. 4, the side edges 41 a and 41 b of the packaging film 41 are in a state referred to as envelope attachment (the overlapping portion is ribbed from its peripheral portion. Do not stand up like a flat, but flat). This superposition is performed so that the corona discharge treatment regions 43A and 43B are in direct contact with each other. If it does in this way, it will block because the corona discharge treatment area | region 43A, 43B is mutually activated. Further, the overlapping portion is sandwiched between the receiving plate 14 and the pressing roller 15 with an appropriate force F. Thereby, the said blocking is ensured and the adhesive strength can also be raised more.

  According to the technique combining the corona discharge treatment and the blocking described above, both side edge portions 41a and 41b of the packaging film 41 can be appropriately bonded with sufficient adhesive strength. The inventors of the present invention conducted various tests on this point, and depending on the material of the packaging film, for example, in the case of a polypropylene-based heat-shrinkable film, the packaging film to be overlaid as the degree of corona discharge treatment When the wetting tension (JISK6768) of these two surfaces was 38 mN / m, it was confirmed that it was possible to block the adhesive strength to withstand practical use. In the above case, it was confirmed that 42 to 48 mN / m was particularly preferable.

  In the cylindrical state of the packaging film 41 shown in FIG. 4, the printed layer 46 is not formed on the one side edge 41a that is blocked, but the printed layer 46 is formed on the other side edge 41b. The printed layer 46 of the other side edge 41b can be seen through from the outside via the one side edge 41a. Therefore, the packaging film 41 has an appearance in which printing is performed even on the blocked part, and the entire surface of the packaging film 41 appears to be printed.

  Moreover, the above-described blocking is performed as a result of increasing the wettability and reactivity of the surface by generating a functional group having high reactivity and polarity on the surface of the adhesion target portion by corona discharge treatment. Therefore, even when the anti-static treatment film 41 is used as the packaging film 41, the side edges 41a and 41b can be firmly bonded. Furthermore, in the present embodiment, since both side edges 41a and 41b of the packaging film 41 are blocked in a so-called envelope pasting state, they are different from the case of so-called palm-pasting described with reference to FIG. It is not necessary to cut and remove part of the side edge portions 41a and 41b as unnecessary portions. Accordingly, it is possible to prevent so-called seal residue.

  In FIG. 1, at a position subsequent to the former 10, the packaging film 41 is fused and sealed between the packaging objects 40 by using a pair of fusing sealers 12. As a result, as shown in FIG. 5, a package 4 having a structure in which a short packaging film 41 ′ having a pair of fusing seal portions 44 at both ends covers the entire packaging object 40 is obtained. A bonding portion 45 corresponding to a so-called center seal is present on the lower side of the package 4, and the bonding portion 45 has a structure in which both side edges 41 a and 41 b of the packaging film 41 ′ overlap and block. It has become.

  The package 4 described above is carried into the heating tunnel 2 by the discharge conveyor 13 and heated. By this heating, the packaging film 41 ′ contracts, and a packaging body 4 </ b> A of a type called an overlap shrink packaging body as shown in FIG. 6 is obtained. In this package 4A, the film of the bonding portion 45 is contracted and is in close contact with the bottom surface portion of the packaging object 40 in a moderately tensioned state. For this reason, the adhesive strength of the bonding portion 45 is further increased, and there is no possibility that the bonding portion 45 is inadvertently peeled off when the overlap shrink package 4A is handled in a distribution process such as sales. .

  As described with reference to FIG. 4, the bonding layer 45 is also provided with a printing layer 46. Therefore, the package 4A has a so-called full-surface printed design and is excellent in decorativeness. Further, as the packaging film 41 ′, a film subjected to antistatic treatment can be used. For example, when the packaging body 4A is displayed on the commodity, dust or the like is quietly placed on the packaging film 41 ′. It is possible to eliminate the possibility of electroadhesion. Furthermore, this package 4A has a structure in which a corona discharge treatment is applied to the packaging film 41 ′ at the bottom, but the activated part is not exposed to the outside. Yes. Therefore, when the plurality of packaging bodies 4A are stacked one above the other, there is no possibility that the packaging films 41 'of these packaging bodies 4A are blocked.

  The content of the present invention is not limited to the above-described embodiment. The specific configuration of each step of the packaging method according to the present invention can be variously changed. Similarly, the specific configuration of each part of the packaging device and the packaging body according to the present invention can be varied in design in various ways.

  When printing is performed on the packaging film, depending on the material of the packaging film, it may be necessary to perform a corona discharge treatment on the planned printing area before printing. In such a case, in the present invention, a corona discharge treatment (generally performed during the production of the packaging film) performed for printing may be used for blocking the film. More specifically, referring to FIG. 3, when a corona discharge treatment is performed to improve the printing characteristics of the single side 42 a before printing on the single side 42 a of the packaging film 41, the single side 42 a. Is subjected to a corona discharge treatment, and the corona discharge treatment is also applied to the one side edge portion 43A which is not a print target region. If it does in this way, after only giving the corona discharge process only to the surface 42b opposite to the other side edge part 41b of the packaging film 41 after that, each adhesion surface of both side edge parts 41a and 41b will be corona discharge process area | region 43A, 43B, which is reasonable. However, since the effect of the corona discharge treatment performed before printing (at the time of film production) may decrease with time, it is preferable to re-execute the corona discharge treatment before the packaging work of the packaging object. In particular, in the case of a polypropylene-based shrink film, the corona discharge treatment effect tends to decrease with time. In such a case, it is preferable to perform the corona discharge treatment immediately before the blocking step.

  The corona discharge treatment does not necessarily have to be performed in the process in which the packaging film is sent to the former in the packaging device. In the present invention, for example, a packaging film that has been subjected to corona discharge treatment may be set in a packaging device, and the packaging operation may be performed using the packaging film.

  The packaging method according to the present invention is not limited to packaging using a pillow packaging machine. Any packaging method may be used as long as the packaging object is covered with a packaging film and a part of the packaging film is bonded to each other. In addition, when the packaging object is covered with the packaging film, it is not always necessary to cover the entire packaging object, and the packaging method according to the present invention is also applied when packaging only a part of the packaging object. Can do.

  The packaging apparatus according to the present invention is suitable for application to a pillow packaging machine, but is not limited to this, as is the case with the packaging method according to the present invention. In the present invention, the specific material of the packaging film is not limited, and it is needless to say that various articles can be applied as the packaging object.

It is a schematic whole side view which shows an example of the packaging apparatus which concerns on this invention. It is a principal part perspective view of the packaging apparatus shown in FIG. It is sectional drawing which shows an example of the film for packaging. It is IV-IV sectional drawing of FIG. (A) is sectional drawing which shows an example of the package body before a shrink process, (b) is the bottom view. (A) is sectional drawing which shows an example of the package body after a shrink process, (b) is the bottom view. It is explanatory drawing of the heat seal method.

Explanation of symbols

DESCRIPTION OF SYMBOLS A Packaging apparatus 1 Pillow packaging machine 2 Heating tunnel 3 Corona discharge treatment apparatus 4, 4A Packaging body 10 Former 11 Supply conveyor (supply means)
32 Cover body 39 Ozone decomposing apparatus 40 Packaging object 41 Packaging film 41a, 41b Side edge (of packaging film)
43A, 43B Corona discharge treatment area 46 Print layer

Claims (3)

A covering step of covering an object to be wrapped with a packaging film;
An adhesion process in which a part of the packaging film is laminated and adhered;
A packaging method comprising:
In the previous step of the coating step, the packaging film is subjected to corona discharge treatment to activate its surface,
A packaging method using corona discharge treatment, wherein in the bonding step, portions of the packaging film that have been subjected to corona discharge treatment are blocked. A former that forms a cylindrical shape by superimposing both side edges of a belt-like packaging film;
A supply means for sequentially supplying a plurality of packaging objects into the packaging film formed in the cylindrical shape;
Cutting means for cutting the packaging film at a position between the plurality of packaging objects, and a packaging device,
A packaging apparatus, comprising: a corona discharge treatment device that performs corona discharge treatment on both side edges before the side edges of the packaging film are overlaid. A packaging object in which a packaging object is covered with a packaging film, and a part of the packaging film is overlapped and bonded,
The packaging body characterized in that adhesion of parts of the packaging film is performed by blocking surfaces activated by corona discharge treatment.