JP2008050041A - Heat-shrink packaging method by heat-shrinkable film, and heating device for heat-shrinkable film, and heat shrink packaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-shrink packaging method for an article to be packaged which can stably join a heat-shrinkable film to the article to be packaged by uniformly heat-shrinking the heat-shrinkable film by using a heating medium of high heating value per unit volume, and also, which can easily package the article to be packaged over a short period of time without making moisture stick to the article to be packaged or the heat-shrinkable film. <P>SOLUTION: In this heat-shrink packaging method, at least certain parts of articles 7 and 49 to be packaged are covered with the heat-shrinkable films 8 and 50, and the heat-shrinkable films 8 and 50 are closely joined to the peripheral surfaces of the articles 7 and 49 to be packaged by heat-shrinking the heat-shrinkable films 8 and 50. Thus, the articles 7 and 49 to be packaged are packaged with the heat-shrinkable films 8 and 50 by the heat-shrink packaging method. Super-heated steam is jetted to the heat-shrinkable films 8 and 50 which are covering the articles 7 and 49 to be packaged, and the heat-shrinkable films 8 and 50 are heat-shrunk. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat-shrink packaging method and apparatus for packaging a package by heat-shrinking a heat-shrinkable film coated on the package, and in particular, without causing water droplets to adhere to the package. The present invention relates to a heat shrink wrapping method and apparatus capable of heat shrinking a heat shrinkable film uniformly over time.

  Conventionally, many heat-shrinkable films have been used as packaging plastic films. As a packaging method using this heat-shrinkable film, the peripheral surface of the package is covered with the heat-shrinkable film, and the heat-shrinkable film is melted in accordance with the shape and dimensions of the packaged object, and the fused edge 2. Description of the Related Art A technique for packaging an object to be packaged by welding the edge and then heat-shrinking the heat-shrinkable film to bring it into close contact with the peripheral surface of the object to be packaged is widely known.

  An invention relating to packaging an object to be packaged by heat-shrinking such a heat-shrinkable film is disclosed in JP-A-10-194242 (Patent Document 1). In the heat shrink wrapping method using the heat shrinkable film described in Patent Document 1, a wide heat shrinkable film is folded in half along the longitudinal direction and introduced into the opening device, and the cross section is reversed while being reversed by the opening device. Open in a U-shape and introduce the article to be packaged into the opening. Subsequently, the article to be packaged introduced into the opening of the heat-shrinkable film is conveyed under the L-shaped heat sealer by a belt conveyor serving as a conveying means, and then the L-shaped heat sealer The heat-shrinkable film existing along the two peripheral surfaces is fused and simultaneously welded. Thereafter, the package covered with the heat-shrinkable film is sent to a heat tunnel which is a heat-shrinkable film heat-shrink device, and the heat-shrinkable film is heated and shrunk to surround the package. The heat shrink wrapping of the article to be packaged is completed.

  In the heat shrink wrapping of an object to be packaged by such a heat shrinkable film, as the heat shrink device (heat tunnel), a device for heat shrinking the heat shrink film using hot air is widely used. For example, as shown in FIGS. 8 and 9, a heat shrinkable film heating / shrinking device 51 using hot air introduces a package 58 covered with the heat shrinkable film 59 into the room, and the heat shrinkable film 59. A heating / shrinking chamber 52 for heating and shrinking, a belt conveyor 53 for transporting an article 58, a blowing means 54 for continuously blowing and circulating air in the heating / shrinking chamber 52, and circulation in the heating / shrinking chamber 52. A heating heater 55 that heats the air to be heated, and a plurality of hot air injection nozzles 56 that are formed on the inner wall surface of the heating shrinkage chamber 52 and that inject hot air heated by the heating heater 55 toward the packaged object 58. is doing. The arrows shown in FIGS. 8 and 9 indicate the flow of hot air heated by the heater 55, and the hot air heated by the heater 55 is heated by the hot air injection nozzle 56 in the heating shrinkage chamber 52. After being injected into the room, it is circulated so as to flow again to the heater 55 through the blowing means 54 from the outlet 57 provided on the upper surface of the heating shrinkage chamber 52.

  According to such a heat-shrink device 51, when the article 58 covered with the heat-shrinkable film 59 passes through the heat-shrink chamber 52 by the belt conveyor 53, the left and right inner wall surfaces and bottom surfaces of the heat-shrink chamber 52 are used. By spraying hot air from the plurality of hot-air spray nozzles 56 disposed on the package object 58, the heat-shrinkable film 59 can be heated and shrunk with hot air to package the package object 58. In addition, since the heat-shrinkable film 59 can be heated without using moisture, when packaging a paper or powder, or an object to be packaged (for example, a food lid) that dislikes moisture or moisture in terms of food hygiene. It can be suitably used.

  However, the heating / shrinking device 51 that performs heating / shrinking with hot air has a low amount of heat per unit volume of hot air, and it is necessary to heat the air to a temperature higher than the film heating temperature in order to compensate for it. There was a drawback of being low. Moreover, since air is used as the heat medium, temperature unevenness is likely to occur in the hot air, and it is difficult to uniformly heat the heat-shrinkable film. Therefore, there is a problem that shrinkage unevenness occurs in the heat-shrinkable film, and further, the heat-shrinkable film is broken due to the heated air locally becoming high temperature. Thus, in order to package the packaged item in a good manner, a high technical force is required such as precisely adjusting the arrangement of the hot air injection nozzles according to the shape of the packaged item and the like.

  In recent years, heat shrink wrapping with heat shrinkable film has been used in various fields. However, it can be broadly divided into one that wraps the entire package with heat shrinkable film and only a part of the package. Can be divided into packaging. For example, heat-shrinkable packaging that wraps the entire packaged object with a heat-shrinkable film uses a biaxially stretched film as the heat-shrinkable film. It's being used.

  In addition, containers such as cup ramen are increasingly printed on the heat-shrinkable film itself to be packaged without printing characters or patterns on the container due to problems such as recycling of garbage. Furthermore, due to concerns about the propagation of germs due to residual water droplets, a heat-shrinking apparatus that jets hot air as described above is generally used when heat-shrinking a heat-shrinkable film. However, as described above, the heat shrink device that ejects hot air causes unevenness of shrinkage in the heat shrinkable film and easily causes distortion in printing. Therefore, a high level of technical ability to adjust the cost is required, which has been one of the causes of cost increase.

  On the other hand, in the heat shrink device for heat shrinking the heat shrinkable film, in addition to the heat shrink device 51 for injecting hot air, the heat shrink by spraying steam (water vapor) onto the packaged object and the heat shrinkable film. There is also known a heat shrink device for heat shrinking a conductive film. In such a heat shrinkable film heat shrinkable apparatus using steam, water vapor is used as a heat medium, so that the heat amount per unit volume is higher than that of the heat shrinkable apparatus 51 that injects hot air, and the heat shrinkable film. Can be uniformly shrunk to obtain a stable packaging finish.

  However, since the heat shrink device for injecting water vapor is 100 ° C. or less under the condition of the water vapor temperature of 1 atm, the shrinkage stress of the heat shrinkable film is small, for example, the packaged object has a complicated shape. In addition, if large irregularities are formed on the peripheral surface, problems such as failure to sufficiently adhere the heat-shrinkable film to the package are caused. In addition, since water vapor is in direct contact with the package or heat-shrinkable film, there is a problem that it is difficult to use for the package or the like that hate moisture and moisture as described above. The range of things was greatly limited. Furthermore, in addition to the disadvantage of large heat loss due to the formation of water droplets of steam, for example, when packaging a package packaged with a heat-shrinkable film in a post-process, such as drying before packaging the cardboard. Since it is necessary to perform processing, there are problems such as complicated work and increased costs.

Therefore, in order to solve the above-described various problems in the heating and shrinking apparatus for jetting hot air and the heating and shrinking apparatus for jetting water vapor, Japanese Patent Application Laid-Open No. 2001-48128 (Patent Document 2) discloses heat shrinkability. A heat-shrinkable packaging is disclosed in which a heat-shrinkable film is heated and shrunk using a mixture of hot air and steam (or humidified air) to the object to be packaged coated with the film, thereby packaging the object to be packaged. ing. According to the heat-shrink packaging using a mixture of hot air and steam as disclosed in Patent Document 2, the heat-shrinkable film is heated and contracted by the hot air in a wet state. It is possible to wrap the packaged product evenly in close contact with the surface of the packaged product, and the amount of moisture attached to the packaged product or heat-shrinkable film is small, so moisture is removed in the subsequent process. It is said that processing such as drying is not required.
JP-A-10-194242 JP 2001-48128 A

  However, when the heat-shrinkable film is heated and shrunk by a mixture of hot air and steam as disclosed in Patent Document 2, for example, the ratio of the steam to be mixed is increased to increase the moisture in the heat-shrinking device. Although the amount of heat per unit volume can be increased as compared with hot air, the temperature of the mixture sprayed onto the package is inevitably lowered, so that the shrinkage stress of the heat-shrinkable film tends to be insufficient. As a result, it is difficult to sufficiently adhere the heat shrinkable film to a packaged object having a complicated shape or a packaged object having large irregularities on the peripheral surface, and stable packaging cannot be performed. Still remained.

  On the other hand, when the temperature of the mixture is increased by reducing the ratio of steam, the amount of heat per unit volume decreases, and the temperature of the mixture becomes uneven and heats the heat-shrinkable film uniformly. This makes it difficult to cause shrinkage unevenness or bag breakage of the heat-shrinkable film. Therefore, even if the heat-shrinkable film is heated and shrunk with a mixture of hot air and steam, it is difficult to increase the amount of heat per unit volume and the temperature of the mixture at the same time. I could not expect a big effect that could be solved.

  By the way, when packaging an object having a shape elongated in the longitudinal direction, such as a PET bottle or a single bottle, for example, with a heat-shrinkable film, conventionally, a printed uniaxially stretched film is generally used as the heat-shrinkable film. It is used for. In addition, when packaging a vertically long packaged article using a uniaxially stretched film subjected to such printing, heat shrinkage of a heat-shrinkable film by hot air or water vapor is used, particularly in recent years, Along with the speeding up of the packaging process, a method of performing heat shrinkage with steam having a high calorie per unit volume has become mainstream.

  In addition, for example, when an object to be packaged such as a bottle of bread is entirely packaged with a heat-shrinkable film, as shown in FIG. The shrinkage ratio of the heat shrinkable film 50 must be greatly different. However, in the conventional packaging in which the heat-shrinkable film 50 is heated and shrunk by hot air or steam, the shrinkage unevenness occurs or the shrinkage stress is insufficient, so that the entire package 49 is made of one heat-shrinkable film. 50, it was difficult to package in good appearance. For this reason, it is necessary to divide and cover the heat-shrinkable film 50 into the body portion 49a and the cap portion 49b of the package 49, and heat-shrink the respective heat-shrinkable films 50 to perform heat-shrink packaging. In addition, the packaging work is complicated and the working time is increased, and the packaging design is limited.

  The present invention has been made in view of the above-described conventional problems, and a specific object thereof is to uniformly heat-shrink a heat-shrinkable film using a heat medium having a high amount of heat per unit volume of the heat medium. In addition, it is possible to stably adhere the heat-shrinkable film to the package without causing unevenness of the film or bag breakage, and without attaching moisture to the package or the heat-shrinkable film. Another object of the present invention is to provide a heat shrink wrapping method for packaging objects and an apparatus for packaging the packaging objects which can be packaged easily in a short time.

  In order to achieve the above object, a heat shrink wrapping method for an object to be packaged provided by the present invention includes, as a basic structure, covering at least a part of the object to be packaged with a heat shrinkable film, A heat shrink wrapping method for wrapping the package with the heat-shrinkable film by heat shrinking the film and bringing it into close contact with the peripheral surface of the package. The main feature is to heat-shrink the heat-shrinkable film by injecting superheated steam onto the film.

  In particular, in the heat shrink packaging method according to the present invention, it is preferable to use superheated steam that is higher than 100 ° C. and lower than or equal to 300 ° C. when 1 atm is used as the superheated steam.

  Next, the heat-shrinkable film heat-shrink device provided by the present invention comprises a heat-shrinkable chamber for heat-shrinking a heat-shrinkable film covering at least a part of an article to be packaged introduced into the room, and the heat shrinkage A packaged article transport unit for passing the packaged article through the room, a superheated steam generator for generating superheated steam for heating and shrinking the heat-shrinkable film, and the superheated steam generated by the superheated steam generator. And a superheated steam guide path for guiding the superheated steam into the heating shrinkage chamber and an inner wall surface of the heating shrinkage chamber and injecting the superheated steam guided by the superheated steam guide path toward the heating shrinkage chamber. A superheated steam injection nozzle, and forcibly sending the superheated steam toward the superheated steam injection nozzle in the superheated steam guide path. It is preferred that also comprises blower.

  Further, in the heating and shrinking device of the present invention, the superheated steam is superheated steam, and the superheated steam generation device is disposed between a steam generation source and the superheated steam guide path, and steam is heated using a heating unit. It is preferable to include a superheated portion that heats and a heating temperature adjusting means that adjusts the heating temperature of the heating means. Furthermore, it is more preferable that a flow rate control valve for adjusting the flow rate of the generated superheated steam is disposed on the downstream side of the superheated portion.

  Furthermore, the heat shrink wrapping apparatus provided by the present invention supplies a heat shrinkable film in accordance with the supply of the package to be packaged, and supply means for supplying the package continuously or intermittently. Film supply means, film covering means for covering the supplied packaged article with the heat-shrinkable film, and conveyance for conveying the packaged article coated with the heat-shrinkable film by the film coating means And a heating / shrinking device having the above-described configuration of the present invention for heat-shrinking the heat-shrinkable film coated on the package.

  The heat shrink wrapping method of a packaged article according to the present invention is a conventional hot air, steam (saturated steam), or hot air and steam as a heat medium for heat shrinking a heat shrinkable film covering the package. Are not used, but superheated steam obtained by further heating saturated steam is used. By heat-shrinking the heat-shrinkable film using superheated steam in this way, the amount of heat per unit volume can be greatly increased compared to the heat medium that has been used conventionally, and the heat-shrinkable film is saturated with saturated steam. It is possible to heat shrink at a higher temperature.

  Therefore, as a first effect of the present invention, the heat-shrinkable film can be uniformly heated and shrunk with sufficient shrinkage stress. Even if the package has a complex shape or large irregularities on its peripheral surface, the heat-shrinkable film can be stably adhered to the package, and the aesthetics of the packaged product should be greatly improved than before. Is possible. In addition, since shrinkage unevenness is unlikely to occur in the heat-shrinkable film, high-precision adjustment technology of the injection nozzle that injects superheated steam toward the packaged object is not required, and thus heat-shrink packaging can be easily performed. it can.

  In addition, as a second effect of the present invention, since the superheated steam has a large amount of heat per unit volume, the heat shrinkable film can be quickly and reliably subjected to heat shrinkage in a short time. For this reason, not only can the number of packaging processes per unit time be increased, but also the apparatus can be reduced in size and energy can be saved.

  Furthermore, in the present invention, the superheated steam that is higher than 100 ° C. and lower than or equal to 300 ° C., preferably higher than 120 ° C., preferably higher than or equal to 120 ° C., based on 1 atm, is preferably used. As the second effect is more remarkably obtained and the heating temperature of the heat-shrinkable film is higher than 100 ° C., as a third effect of the present invention, water droplets adhere to the package and the heat-shrinkable film. Can be prevented. For this reason, this invention can be used suitably also when packaging the to-be-packaged object which dislikes a water | moisture content and humidity. Moreover, if it is superheated steam, there will be no bad influence on an environment and packaging of a to-be-packaged item can be performed safely. In the present invention, the superheated steam only needs to have a temperature of 1 atm higher than 100 ° C. and 300 ° C. or lower. When the atmospheric pressure is lower than 1 atm, the temperature of the superheated steam is higher than 100 ° C. Becomes smaller.

  Next, the heat shrinkable film heat shrinking device according to the present invention guides the superheated steam generated by the superheated steam generating device to the superheated steam injection nozzle through the superheated steam guide path, and heats it from the superheated steam injection nozzle. It is comprised so that it may inject toward the room | chamber of a contraction chamber. As a result, the heat-shrinkable film covering the object to be packaged can be heated and shrunk with superheated steam (particularly, superheated steam) as described above to stably package the object to be packaged.

  In addition, the heating and shrinking device of the present invention further includes a blower that forcibly sends the superheated steam toward the superheated steam injection nozzle, thereby allowing the superheated steam to smoothly flow to the superheated steam injection nozzle. The superheated steam can be stably injected from the superheated steam injection nozzle.

  In particular, in the present invention, the superheated steam generating device includes a superheater that superheats water vapor using a heating means, and a heating temperature adjusting means that adjusts the heating temperature of the heating means, thereby stabilizing the superheated steam. And the temperature of the superheated steam can be adjusted with high accuracy. This makes it possible to supply superheated steam at an appropriate temperature according to the nature and shape of the package, the material of the heat-shrinkable film, etc. Can be performed. In addition, the heat shrink device of the present invention has a flow control valve for adjusting the flow rate of the superheated steam downstream of the superheated portion, so that the flow rate of the superheated steam can be controlled, and the heat shrinkable film. It becomes possible to carry out heat shrink wrapping more appropriately.

  And the heat-shrink packaging apparatus provided with the heat-shrink apparatus which has the structure of this invention as mentioned above can heat-shrink the heat-shrinkable film which coat | covers the to-be packaged object with superheated steam (superheated steam). Therefore, the heat-shrinkable film is uniformly heat-shrinked and stably adhered to the package, and the package is easily packaged in a short time without attaching moisture to the package or heat-shrinkable film. It becomes a heat shrink wrapping apparatus that can be used.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiments described below, and various modifications are possible as long as they have substantially the same configuration as the present invention and have the same effects. Is possible. For example, in the present invention, a package supply means for supplying a package, a film supply means for supplying a heat-shrinkable film, and a film coating means for coating the heat-shrinkable film on the package include the following examples. It is not limited at all to this configuration, and can be changed as appropriate according to the nature, shape, etc. of the item to be packaged.

  FIG. 1 is a perspective view schematically showing the configuration of the heat shrink wrapping apparatus according to Embodiment 1 of the present invention. 2 and 3 are a vertical cross section of the heat-shrinking device shown by the line II-II in FIG. 1 and a cross-sectional view of the heat-shrinking device shown by the line III-III. FIG. It is the schematic diagram which showed the structure of the apparatus.

  The heat shrink wrapping apparatus 1 according to the first embodiment includes a package supply means 2 for supplying a package 7, a film supply means 3 for supplying a heat shrinkable film 8, and a heat shrinkable film on the package 7. A film covering means 4 for covering 8, a transport means 5 for transporting a package 7 coated with the heat-shrinkable film 8 by the film-covering means 4, and a heat-shrinking device 6 for heat-shrinking the heat-shrinkable film 8. I have. In Example 1, the packaged article supply means 2, the film supply means 3, the film coating means 4, and the transport means 5 are substantially the same as those described in Patent Document 1. The heat shrink wrapping device 1 is mainly characterized by the structure of the heat shrink device 6. Hereafter, each means and apparatus which comprise the heat shrink packaging apparatus 1 are demonstrated in detail.

  The packaged article supply means 2 is constituted by a first belt conveyor 2 a arranged so as to pass through between film openings 13 (to be described later) of the film supply means 3, and the packaged article 7 is directed to the film coating means 4. Can be supplied continuously or intermittently.

  The film supply means 3 includes a film winding roll body 11 in which a wide heat-shrinkable film 8 is folded in two, a film feeding section 12 for feeding the heat-shrinkable film 8 from the film winding roll body 11, and a film A film opening 13 is provided that opens the folded two-fold heat-shrinkable film 8 fed from the feeding section 12 and feeds it along the transport direction of the article supply means 2. The film winding roll 11 and the film feeding unit 12 are arranged on the side of the packaged article supply means 2 so that the axial direction thereof is parallel to the transport direction of the packaged article supply means 2.

  The film opening 13 has an upper guide plate 14 disposed above the first belt conveyor 2a and a lower guide plate 15 disposed on the back side so that the package 7 can pass through them. In addition, the upper and lower guide plates 14 and 15 are installed in a state of sandwiching the first belt conveyor 2a with a predetermined interval therebetween. The upper and lower guide plates 14 and 15 are integrally connected by a pair of left and right support rods (not shown). Furthermore, the package introduction port 16 is opened obliquely on the opposite side of the film feeding portion 12 so that the widthwise dimensions of the upper and lower guide plates 14 and 15 gradually increase toward the downstream side of the first belt conveyor 2a. I am letting.

  That is, both the upper and lower guide plates 14 and 15 have a substantially right triangular shape having the same size, and the introduction side edge portion 17 of the package introduction port 16 is used as a hypotenuse opposite to the right angle portion. 18 is formed. Therefore, in the film opening portion 13, the upper surface side of the two-fold heat-shrinkable film 8 drawn from the film feeding portion 12 is brought into contact with the upper surface of the upper guide plate 14, and the lower surface side of the heat-shrinkable film 8 is set to the lower side. While being inserted under the guide plate 15, by folding back at the introduction side edges 17 and 18 of the guide plates 14 and 15, respectively, the two-fold heat-shrinkable film 8 is opened upside down at the package introduction port 16, and opened. And it can send out toward the film coating | coated means 4 in the opened state.

  The film covering means 4 has an L-type sealer 19 capable of fusing and welding the heat-shrinkable film 8 in two directions, the longitudinal direction and the width direction, with a fulcrum centered on the seal cradle 20. It is provided so that rotation is possible. The L-shaped sealer 19 is a frame material having two sides sandwiching one corner portion of the U-shaped base frame 19a (that is, the side on which the upstream frame material of the base frame 19a and the heat-shrinkable film 8 are open). An L-shaped heat bar is fixed to the lower surface of the frame material), and a sealing cutter blade made of a metal having good thermal conductivity protrudes downward from a substantially central portion in the width direction of the heat bar. .

  In addition, a cushion body made of silicon rubber is disposed on the upper surface of the seal cradle 20, and a concave groove is formed in the cushion body at a portion corresponding to the sealing cutter blade of the L-type sealer 19. Has been. Therefore, the film covering means 4 rotates the L-type sealer 19 so as to close the abutment against the seal cradle 20, so that the heat-shrinkable film 8 is moved in the longitudinal direction and width by the sealing cutter blade heated by the heat bar. It is possible to melt the heat-shrinkable film 8 at the melted portion while fusing in two directions.

  The transport means 5 receives the package 7 supplied from the package supply means 2 and introduced into the opening of the heat-shrinkable film 8 and transports the package 7 together with the heat-shrinkable film 8. It is comprised by the 2nd belt conveyor 5a. The second belt conveyor 5a temporarily stops the package 7 introduced into the opening of the heat-shrinkable film 8 to a predetermined position, and further stops the heat-shrinkable film 8 by the film coating means 4. The drive is controlled by a drive control device (not shown) so that the article to be packaged 7 is conveyed to the next heating / shrinking device 6 after the operation is performed.

  As shown in FIGS. 2 and 3, the heating / shrinking device 6 has a heating / shrinking chamber 21 that heat-shrinks the heat-shrinkable film 8. The heating / shrinking chamber 21 includes a superheated steam generator 23. The superheated steam inlet 27 into which the superheated steam generated in step S2 flows in, the superheated steam injection nozzle 24 disposed on the inner wall surface of the heating shrinkage chamber 21, and the superheated steam from the superheated steam inlet 27 toward the superheated steam injection nozzle 24 are supplied. A superheated steam guide path 25 for guiding and a superheated steam discharge port 28 for discharging the superheated steam injected from the heat steam injection nozzle 24 are formed.

  In the first embodiment, the superheated steam inlet 27 is disposed on the side surface of the protruding portion 21 a that protrudes from the upper surface of the heating shrinkage chamber 21. In addition, an air blower 26 having a blower fan 26a and a drive part 26b for rotating the blower fan 26a is disposed on the protruding portion 21a. The superheated steam that has flowed from the superheated steam inlet 27 by the blower 26. Is blown toward the superheated steam injection nozzle 24 to smoothly distribute the superheated steam.

  A plurality of the superheated steam injection nozzles 24 are formed on the inner wall surface on the left and right sides of the heating shrinkage chamber 21 and the inner wall surface of the bottom. In the present invention, the position and number of the superheated steam injection nozzles 24 and the shape and dimensions of the superheated steam injection nozzles 24 are not particularly limited and can be appropriately changed.

  In addition, the heating and shrinking device 6 has an article transporting part 22 for placing the article 7 to be wrapped that has been transported by the second belt conveyor 5a and transporting the article so as to pass through the inside of the heat shrinking chamber 21. is doing. The packaged article transport unit 22 includes a third belt conveyor 22a in which a placement surface on which the packaged article 7 is placed is formed in a mesh shape.

  Furthermore, the superheated steam inlet 27 is connected to a superheated steam generator 23 that generates superheated steam. As shown in FIG. 4, the superheated steam generator 23 includes a superheater 32, an electromagnetic induction heating coil 33 disposed on the outer peripheral surface of the superheater 32, and an adjusting unit 34, and generates steam. Steam generated by heating water at the source 31 is introduced into the superheater 32 through the pipe 36, and the steam is further heated by the heating coil 33 in the superheater 32 to generate superheated steam. .

  In addition, the superheated steam generator 23 is provided with a flow control valve 35 on the downstream side of the superheater 32 so that the flow rate of the superheated steam can be adjusted when the generated superheated steam is supplied to the heat shrink chamber 21. Further, the adjusting means 34 is configured to be able to adjust the heating temperature of the heating coil 33 and the opening degree of the flow rate control valve 35, and controls the temperature and flow rate of superheated steam supplied to the heat shrink chamber 21. Yes. Note that the superheated steam generator in the present invention does not use a method of heating water vapor by the electromagnetic induction heating coil 33 as described above. For example, a method of heating water vapor by combustion of a burner or another heating method is used. It may be used to heat water vapor.

  Next, with respect to the heat shrink wrapping method for heat shrink wrapping the article to be packaged 7 by heat shrinking the heat shrinkable film 8 using the heat shrink wrapping apparatus 1 of the first embodiment as described above, FIG. This will be described with reference to FIG. In addition, in the present Example 1, the case where the whole peripheral surface of the to-be-packaged goods 7 is packaged with the heat-shrinkable film 8 like when packaging containers, such as a cup ramen, is demonstrated.

  First, the article 7 to be packaged is placed on the first belt conveyor 2a of the article supply means 2 and conveyed toward the film covering means 4, and the heat-shrinkable film 8 folded in half is fed to the film winding roll body 11. , And is opened at the film opening 13 and sent out toward the film covering means 4. At this time, since the first belt conveyor 2a is arranged so as to pass through between the upper and lower guide plates 14 and 15 of the film opening 13, when the article 7 is transported to the film covering means 4, the film The package 7 can be stably introduced into the heat-shrinkable film 8 opened at the opening 13. In the present invention, the material of the heat-shrinkable film 8 is not particularly limited, and heat-shrinkable films such as polyethylene, polypropylene, and polyester that are conventionally commercially available can be used.

  Next, the article 7 to be packaged introduced into the heat-shrinkable film 8 at the film opening 13 is transferred from the first belt conveyor 2a to the second belt conveyor 5a of the conveying means 5, and this second belt conveyor 5a. Thus, the package 7 is conveyed to a predetermined position where the heat-shrinkable film 8 can be melted and welded by the film covering means 4 and stopped at that position.

  After the package 7 covered with the heat-shrinkable film 8 stops at a predetermined position, the L-type sealer 19 of the film covering means 4 is rotated downward so that the L-type sealer 19 contacts the seal cradle 20. Make contact. At this time, both the upper and lower surfaces of the heat-shrinkable film 8 are melted in the longitudinal direction and the width direction by the heated sealing cutter blade provided in the L-type sealer 19, and the heat-shrinkable film is blown. The upper and lower fusing edges of 8 can be welded together and sealed. As a result, the entire peripheral surface of the package 7 is covered with the heat-shrinkable film 8. After the heat-shrinkable film 8 is melted and welded by the film covering means 4, the second belt conveyor 5 a is driven again, and the packaged material 7 is conveyed toward the heat shrinking device 6. On the other hand, the cut piece 8 ′ of the heat-shrinkable film 8 that has been cut off by fusing the heat-shrinkable film 8 as described above is taken up by the take-up roller 9.

  Subsequently, the article 7 to be packaged conveyed to the heating / shrinking device 6 is transferred from the second belt conveyor 5a to the third belt conveyor 22a, and further conveyed into the heating / shrinking chamber 21 by the third belt conveyor 22a. The heating / shrinking device 6 continuously generates superheated steam by the superheated steam generation device 23, causes the generated superheated steam to flow from the superheated steam inlet 27, and rotates the blower fan 26a. Thus, the superheated steam is circulated through the superheated steam guide path 25 toward the plurality of superheated steam injection nozzles 24 arranged on the inner wall surface of the heating shrinkage chamber 21, and from each superheated steam injection nozzle 24 to the heating shrinkage chamber. Superheated steam is jetted into 21 rooms.

  At this time, the superheated steam generator 23 generates superheated steam that is higher than 100 ° C. and lower than or equal to 300 ° C. by adjusting the heating temperature of the heating coil 33 with the adjusting means 34. In addition, this invention is not limited to this, Depending on the material of the heat-shrinkable film 8, for example, superheated steam higher than 300 ° C., superheated steam having a temperature of less than 100 ° C. by reducing the entire inside of the heat shrink device 6, Alternatively, other superheated steam obtained by evaporating a liquid other than water can be generated by the superheated steam generator 23 and used.

  And the to-be-packaged object 7 coated with the heat-shrinkable film 8 is conveyed by the third belt conveyor 22a, and the inside of the heat-shrinking chamber 21 in which superheated steam is jetted from the superheated steam jet nozzle 24 is packed. As a result, the heat-shrinkable film 8 is heated and contracted by superheated steam during the passage. Thereby, the heat-shrinkable film 8 can be closely attached to the peripheral surface of the article to be packaged 7, and the article to be packaged 7 can be packaged by the heat-shrinkable film 7. Thereafter, the packaged product 7 ′ wrapped with the heat-shrinkable film 8 is unloaded from the heat-shrink packaging device 1 and the operation is completed.

  Since the heat-shrinkable film 8 can be heated and shrunk by superheated steam by wrapping the package 7 using the heat-shrink packaging device 1 of the first embodiment as described above, the amount of heat per unit volume can be reduced. The heat-shrinkable film 8 can be heated and shrunk at a temperature higher than 100 ° C. As a result, the heat-shrinkable film 8 can be heated and shrunk uniformly and with a sufficient shrinkage stress, so that the heat-shrinkable film 8 does not cause uneven shrinkage or bag breakage and greatly improves the aesthetics of the packaged product 7 '. It becomes possible to make it. Further, since the shrinkage unevenness does not occur in the heat-shrinkable film 8, the heat-shrinkable packaging 8 can be easily and easily distorted without causing distortion in the heat-shrinkable film 8 even without the high-precision adjustment technology of the superheated steam spray nozzle 24. Can be done. Therefore, for example, even when printing is performed on the heat-shrinkable film 8 itself to wrap the package 7, it is possible to reliably prevent printing from being distorted.

  Furthermore, by performing heat shrink wrapping as in Example 1, heat shrinkage of the heat shrinkable film 8 can be performed quickly and reliably in a short time. Not only can the number be increased, but the apparatus can also be reduced in size and energy can be saved. In particular, in Example 1, since the heat-shrinkable film 8 is heated and shrunk by superheated steam higher than 100 ° C., water droplets do not adhere to the packaged goods and heat-shrinkable film, and moisture and moisture. It can also be suitably used when packaging an object to be disliked.

  Next, the heat shrink packaging according to the second embodiment of the present invention will be described with reference to the drawings. Here, FIGS. 5 and 6 are cross-sectional views schematically showing a longitudinal section and a transverse section of the heat-shrinking apparatus of the second embodiment. In the second embodiment, for example, a heat shrinkable film is manually coated on a peripheral surface of an object to be packaged having a shape elongated in a height direction (vertical direction) such as a PET bottle or a single bottle bottle. Then, the case where a heat-shrinkable film is heat-shrinked using the heat-shrinking apparatus according to the present invention to package an article to be packaged will be described. However, the present invention is not limited to this, and the work of covering the heat-shrinkable film on the vertically long packaged object is not performed manually, but automatically, for example, as in the apparatus of the first embodiment. It is also possible to coat the article to be packaged with a heat-shrinkable film.

  The heat-shrink device 40 of the second embodiment includes a heat-shrink chamber 41 that introduces a vertically long packaged article 49 covered with the heat-shrinkable film 50 into the room, heat-shrinks the heat-shrinkable film 50, There is a packaging material transport section 42 on which the packaging material 49 is placed and transported so that the packaging material 49 passes through the heating shrinkage chamber 41, and a superheated steam generation device (not shown) that generates superheated steam. is doing. The heating / shrinking chamber 41 has a superheated steam inlet 47 through which superheated steam generated by the superheated steam generator flows, and superheated steam that flows from the superheated steam inlet 47 into the heating / shrinking chamber 41. A steam guide path 45, a plurality of superheated steam injection nozzles 44 arranged on the inner wall surface of the heating shrinkage chamber 41, and a superheated steam discharge port 48 for discharging superheated steam injected from the thermal steam injection nozzle 44 are formed. Yes. Further, an air blower 46 having a blower fan 46 a and a drive unit 46 b that rotates the blower fan 46 a is disposed upstream of the superheated steam guide path 45, and the superheated steam is smoothly directed toward the superheated steam injection nozzle 44. It encourages its distribution to flow into

  In the second embodiment, the to-be-packaged article transport section 42 is configured by a belt conveyor as in the first embodiment. Further, for the superheated steam generator (not shown), the same apparatus as the superheated steam generator 23 (see FIG. 4) used in the first embodiment is connected to the superheated steam inlet 47, and the heat shrink chamber The temperature and flow rate of superheated steam supplied to 41 are controlled. On the other hand, the superheated steam injection nozzle of the second embodiment is formed only on the left and right inner wall surfaces of the heating shrinkage chamber 41, and each nozzle tip is guided through a superheated steam guide path 45. It has a structure in which the superheated steam is sprayed so as to diffuse into the heat shrink chamber 41.

In the second embodiment, the package 49 can be packaged with the heat-shrinkable film 50 as follows by using the heat-shrink packaging device 40 as described above.
That is, first, the heat-shrinkable film 50 is manually coated on the peripheral surface of the vertically long packaged object 49, and the packaged article 49 of the heat-shrinking device 40 is coated with the package 49 covered with the heat-shrinkable film 50. 42. At this time, the material of the heat-shrinkable film 50 that covers the package 49 is not particularly limited. In Example 2, the film ends are joined to form a cylinder, or the cylinder The heat-shrinkable film is used, and examples of the material of the heat-shrinkable film include polyethylene terephthalate and polystyrene.

  The package 49 covered with the heat-shrinkable film 50 is placed on the package transport unit 42 and then transported into the heat shrink chamber 41 by the package transport unit 42. Pass through. At this time, the heating / shrinking device 40 of the second embodiment continuously generates superheated steam that is higher than 100 ° C. and lower than or equal to 300 ° C. in the superheated steam generator, and the generated superheated steam is used for each superheated steam injection nozzle 44. Is sprayed toward the inside of the heating shrinkage chamber 41. Therefore, since the heat shrinkable film 50 is heated and shrunk by the superheated steam when the package 49 passes through the heat shrink chamber 21, the heat shrinkable film 50 is brought into close contact with the peripheral surface of the package 49, The package 49 can be packaged with the heat-shrinkable film 50.

  As a result, similarly to Example 1, the heat-shrinkable film 50 can be heated and shrunk uniformly and with a sufficient shrinkage stress. Can be greatly improved. Moreover, even if it is a case where the heat shrinkable film 50 itself is printed and the to-be packaged object 49 is packaged, it is possible to reliably prevent printing from being distorted.

  Furthermore, since heat shrinkage of the heat-shrinkable film 50 can be performed quickly and reliably in a short time, not only can the number of treatments of the package 49 per unit time be increased, but also the size of the apparatus can be reduced. It is also possible to save energy, and in addition, water drops do not adhere to the package 49 or the heat-shrinkable film 50, and the package 49 is preferably used even if it hate water and moisture. be able to.

  In addition, in the second embodiment, the following remarkable effects can be obtained. That is, in the past, when a packaged object whose cross-sectional area of the cut surface differs greatly depending on the part, such as a single bottle, for example, as described above with reference to FIG. It was necessary to heat-shrink each heat-shrinkable film 50 after covering the body portion 49a and the cap portion 49b of the package 49 with the heat-shrinkable film 50.

  On the other hand, as in Example 2, the heat shrinkage of the heat-shrinkable film 50 is performed by using the superheated steam having a large amount of heat per unit volume and a temperature higher than 100 ° C. Since the shrinkable film 50 can be reliably shrunk in a short time with a large shrinkage stress, as shown in FIG. Even if covered, the heat-shrinkable film 50 can be stably adhered to the entire peripheral surface of the package 49, and the package 49 can be packaged in good form. As a result, the packaging work can be simplified and the working time can be shortened as compared with the conventional case, and the entire peripheral surface of the packaged product 49 'can be printed, greatly improving the design of the packaging. Can be expanded.

It is the perspective view which showed typically the structure of the heat shrink packaging apparatus which concerns on Example 1. FIG. It is a longitudinal cross-section of the heat contraction apparatus shown by the II-II line in FIG. It is a cross section of the heat contraction apparatus shown by the III-III line in FIG. It is the schematic diagram which showed typically the structure of the superheated steam production | generation apparatus. It is sectional drawing which showed typically the longitudinal cross-section of the heat contraction apparatus which concerns on Example 2. FIG. It is sectional drawing which showed the cross section of the same heating shrinkage | contraction apparatus typically. (A) is explanatory drawing explaining the heat-shrink packaging of the 1 bottle bottle by the heat shrink packaging method of Example 2, (b) is explanatory drawing explaining the heat shrink packaging of the 1 bottle bottle by the conventional packaging method. It is sectional drawing which showed typically the longitudinal cross-section of the heat-shrink apparatus of the heat-shrinkable film with a hot air. It is sectional drawing which showed the cross section of the same heating shrinkage | contraction apparatus typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat-shrink packaging apparatus 2 Package supply means 2a 1st belt conveyor 3 Film supply means 4 Film coating means 5 Conveyance means 5a 2nd belt conveyor 6 Heat shrink apparatus 7 Package 7 'Package 8 Heat-shrinkable film 8 'Cut piece 9 Winding roller 11 Film roll body 12 Film feeding part 13 Film opening part 14 Upper guide plate 15 Lower guide plate 16 Package introduction port 17, 18 Introduction side edge 19 L-type sealer 19a Base frame 20 Seal cradle 21 Heating shrinkage chamber 21a Protruding part 22 Packaged article transporting part 22a Third belt conveyor 23 Superheated steam generator 24 Superheated steam injection nozzle 25 Superheated steam guide path 26 Blower 26a Blower fan 26b Drive part 27 Superheated steam inlet 28 Superheated steam outlet 31 Steam generation source 32 Superheated part 33 Heating coil 34 Adjustment Means 35 Flow rate control valve 36 Piping 40 Heating shrinkage device 41 Heating shrinkage chamber 42 Packaged article transporting part 44 Superheated steam injection nozzle 45 Superheated steam guideway 46 Blower 46a Blower fan 46b Drive part 47 Superheated steam inlet 48 Superheated steam outlet 49 Packaged Items 49 'Packaged Product 49a Body 49b Cap Unit 50 Heat Shrinkable Film 51 Heat Shrink Device 52 Heat Shrink Chamber 53 Belt Conveyor 54 Blowing Means 55 Heating Heater 56 Hot Air Jet Nozzle 57 Outlet 58 Packaged Items 59 Heat Shrink Sex film

Claims (7)

At least a part of the package (7, 49) is covered with a heat-shrinkable film (8, 50), and the heat-shrinkable film (8, 50) is heated and shrunk to form the package (7, 49). A heat shrink wrapping method for wrapping the article to be wrapped (7, 49) with the heat shrinkable film (8, 50)
Heat shrinkability characterized by heating and shrinking the heat shrinkable film (8, 50) by injecting superheated steam onto the heat shrinkable film (8, 50) coated with the package (7, 49). Heat shrink wrapping method with film (8,50).   The heat-shrink packaging method according to claim 1, wherein superheated steam that is higher than 100 ° C and lower than or equal to 300 ° C when 1 atm is used as the superheated steam. A heat-shrinkable chamber (21, 41) for heat-shrinking a heat-shrinkable film (8, 50) covering at least a part of the article to be packaged (7, 49) introduced into the room;
A to-be-packaged article transport section (22, 42) that passes through the heating shrinkage chamber (21, 41) and transports the to-be-packaged article (7, 49);
A superheated steam generator (23) for generating superheated steam that heat-shrinks the heat-shrinkable film (8, 50);
A superheated steam guide path (25, 45) for guiding the superheated steam generated by the superheated steam generator (23) into the heating shrinkage chamber (21, 41);
The superheated steam disposed on the inner wall surface of the heating shrinkage chamber (21, 41) and guided by the superheated steam guide path (25, 45) is jetted toward the heating shrinkage chamber (21, 41). Superheated steam injection nozzle (24,44),
A heat shrinkable apparatus for heat shrinkable film (8, 50) comprising:   The heat according to claim 3, further comprising a blower (26, 46) forcibly sending the superheated steam toward the superheated steam injection nozzle (24, 44) in the superheated steam guide path (25, 45). Heat shrinkage device for shrinkable film (8,50). The superheated steam is superheated steam;
The superheated steam generator (23) is disposed between a steam generation source (31) and the superheated steam guide path (25, 45), and a superheater (32) that superheats steam using heating means, A heating temperature adjusting means (34) for adjusting the heating temperature of the heating means (33),
The heat-shrink device for a heat-shrinkable film (8, 50) according to claim 3 or 4.   The heat shrinkable film (8, 50) heating and shrinking device according to claim 4, wherein a flow rate control valve (35) for adjusting the flow rate of the generated superheated steam is disposed downstream of the superheated portion (32). . Packaged article supply means (2) for continuously or intermittently supplying the packaged articles (7, 49);
Film supply means (3) for supplying a heat-shrinkable film (8, 50) in accordance with the supply of the packaged items (7, 49);
Film coating means (4) for coating the heat-shrinkable film (8, 50) on the supplied article (7, 49);
Conveying means (5) for conveying the packaged article (7, 49) coated with the heat-shrinkable film (8, 50) by the film covering means (4),
The heat-shrinking device (6, 40) according to any one of claims 3 to 6, which heat-shrinks the heat-shrinkable film (8, 50) coated on the package (7, 49),
A heat shrink wrapping apparatus for wrapping the packaged object (7, 49) with the heat shrinkable film (8, 50).

Images