Heat treatment device for heat shrinkable film

Abstract

In a heat treatment device (1) for a heat shrinkable film (F), a conveyance mechanism (10) is configured to convey goods (G) covered with a heat shrinkable film (F). A reheating device (50) is configured to heat a gas mixture (GM) of steam supplied from a steam supply unit (30) and air supplied from an air supply unit (60). A gas jetting unit (70) is configured to jet out the gas mixture (GM) heated by the reheating device (50) toward the heat shrinkable film (F) that is passing through a passage region (R) as a result of the goods (G) being conveyed by the conveyance mechanism (10). The gas jetting unit (70) includes an opposing surface part (71) and slits (72). The opposing surface part (71) is disposed so as to oppose the passage region (R). The slits (72) are formed in the opposing surface part (71). The gas mixture (GM) is jetted out to the passage region (R) by passing through the slits (72).

Description

Heat-shrinkable film heating treatment device

[0001] The present disclosure relates to a heat treatment apparatus for a heat-shrinkable film.

[0002] Patent Document 1 (WO 2020 / 031824) discloses a conventional heat-shrinkable film heat treatment device. In this heat-shrinkable film heat treatment device, superheated steam is ejected from a plurality of nozzles toward a space near a conveying path. Each of the plurality of nozzles faces the conveying path. The plurality of nozzles are arranged in a matrix. The reheating device generates superheated steam by reheating the mixed gas generated in the mixed gas generating unit. The mixed gas generating unit mixes the steam generated in the steam generating unit with the heated air generated in the heated air generating unit.

[0003] Patent Document 2 (JP 2008-150063 A) discloses a conventional heat-shrinking device for shrink film. This heat-shrinking device heats and shrinks a shrink film that covers part or all of an article. The heat-shrinking device for shrink film includes a heat treatment chamber that surrounds a transport path for the article, and a heating means for heating the interior of the heat treatment chamber. The heating means supplies superheated steam into the heat treatment chamber.

[0004] International Publication No. 2020 / 031824 Japanese Patent Application Laid-Open No. 2008-150063

[0005] In heat-treating devices for heat-shrinkable films, improvements in energy efficiency are desired. Specifically, it is desirable to shorten the transport path within the device to quickly shrink the heat-shrinkable film, and to reduce the amount of water vapor used and the energy required to heat the water vapor.

[0006] In order to solve the above problems, it has been considered to suppress the decrease in the temperature of the heated mixed gas from when the heated mixed gas is ejected until when the heated mixed gas reaches the heat-shrinkable film, for example, by locating multiple nozzles close to the heat-shrinkable film.

[0007] However, the closer the distance between the nozzle and the heat-shrinkable film, the more the mixed gas ejected from the nozzle reaches the heat-shrinkable film locally, resulting in both shrunk and unshrunk areas in the heat-shrinkable film, causing so-called uneven shrinkage in the heat-shrinkable film.

[0008] Alternatively, in conventional heat-shrinkable film heating treatment devices, when the film is heated with superheated steam, the superheated steam condenses. The condensed steam turns into droplets that adhere to the article covered with the film. However, if the flow rate of the superheated steam is reduced to reduce the amount of droplets that adhere, the superheated steam will stagnate in the treatment chamber before reaching the article. This causes color unevenness or streaks in the shrunken film, resulting in a poor finish of the shrunken film.

[0009] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a heat treatment device for a heat shrinkable film that can provide a good finish to the heat shrinkable film after shrinkage.

[0010] A heat-shrinkable film heat treatment device according to an aspect of the present disclosure includes a conveying mechanism, a water vapor supplying unit, an air supplying unit, a reheating device, and a gas ejecting unit. The conveying mechanism is configured to convey an article covered with a heat-shrinkable film. The reheating device is configured to heat a mixed gas of water vapor supplied from the water vapor supplying unit and air supplied from the air supplying unit. The gas ejecting unit is configured to eject the mixed gas heated by the reheating device toward the heat-shrinkable film that is passing through a passing region as the article is conveyed by the conveying mechanism. The gas ejecting unit includes an opposing surface and a slit. The opposing surface is arranged to face the passing region. The slit is formed in the opposing surface. The mixed gas is ejected into the passing region by passing through the slit.

[0011] A heat-shrinkable film heat treatment device according to another aspect of the present disclosure heats and shrinks the heat-shrinkable film, thereby covering part or all of an article with the heat-shrinkable film after shrinkage. The heat-shrinkable film heat treatment device includes a treatment chamber, a steam generator, a first path, a reheating device, and a compressed air supply unit. The treatment chamber holds an article covered with the heat-shrinkable film before shrinkage. The steam generator generates steam. One end of the first path is disposed within the treatment chamber. The other end of the first path is connected to the steam generator. The first path causes the steam generated by the steam generator to flow into the treatment chamber. The reheating device is provided in the first path. The reheating device further heats the steam flowing through the first path. The compressed air supply unit is connected to a portion of the first path between the steam generator and the reheating device. The compressed air supply unit supplies compressed air to the first path, thereby mixing air with the steam flowing through the first path.

[0012] According to the present disclosure, it is possible to provide a heat treatment device for a heat shrinkable film that can provide a good finish to the heat shrinkable film after shrinkage.

[0013] 15 is a diagram showing the overall configuration of a heat-shrinkable film heat treatment device according to the first embodiment of the present disclosure. FIG. 16 is a diagram showing a top view of a portion of the heat-shrinkable film heat treatment device according to the first embodiment of the present disclosure. FIG. 17 is a diagram showing a portion of the heat treatment device when the gas ejection section is viewed from the passage area. FIG. 18 is a partial cross-sectional view of the heat treatment device of FIG. 2 as viewed in the direction of the arrows line IV-IV. FIG. 19 is a partial cross-sectional view of the heat treatment device of FIG. 3 as viewed in the direction of the arrows line V-V. FIG. 20 is a partial cross-sectional view of the heat treatment device of FIG. 2 as viewed in the direction of the arrows line VI-VI. FIG. 19 is a partial cross-sectional view of the heat treatment device of FIG. 2 as viewed in the direction of the arrows line VII-VII. FIG. 19 is a cross-sectional view showing modified examples of a current plate and a first side wall section, etc. FIG. 19 is a cross-sectional view showing another modified example of the first side wall section. FIG. 19 is a cross-sectional view showing yet another modified example of the first side wall section. FIG. 19 is a cross-sectional view showing a modified example of a slit. FIG. 19 is a diagram showing a third opposing surface section according to a modified example as viewed from the opposing direction. FIG. 19 is a diagram showing a schematic view of a modified example of a first path and an air supply section. FIG. 19 is a diagram showing a schematic view of another modified example of a first path and an air supply section. FIG. 19 is a diagram showing the overall configuration of a heat treatment device according to a modified example. FIG. 19 is a perspective view partially showing the heat treatment device of FIG. 15. 23 is a diagram showing the overall configuration of a heat-shrinkable film heat treatment device according to embodiment 2. FIG. 24 is a perspective view showing a part of a heat-shrinkable film heat treatment device according to embodiment 2. FIG. 25 is a partial cross-sectional view of a heat treatment device according to embodiment 3 of the present disclosure. FIG. 26 is a partial cross-sectional view of a heat treatment device according to embodiment 4 of the present disclosure. FIG. 27 is a diagram showing an opposing surface portion of a heat treatment device according to another modified example. FIG. 28 is a partial cross-sectional view of a heat treatment device according to yet another modified example. FIG. 29 is a cross-sectional view of the heat treatment device of FIG. 22 as viewed in the direction of the arrows XXIII-XXIII line.

[0014] The heat-shrinkable film heating treatment device according to each embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

[0015] (Embodiment 1) Fig. 1 is a diagram showing the overall configuration of a heat-shrinkable film heat treatment device according to embodiment 1 of the present disclosure. Fig. 2 is a diagram showing a part of the heat-shrinkable film heat treatment device according to embodiment 1 of the present disclosure, viewed from above.

[0016] As shown in Figures 1 and 2, the heat-shrinkable film heat treatment device 1 according to the first embodiment of the present disclosure is an apparatus that uses water vapor (specifically, superheated steam) to heat and shrink a heat-shrinkable film F, thereby covering part or all of an article G with the shrunk heat-shrinkable film FS. In this embodiment, the heat-shrinkable film FS covers part of the article G. Note that in the heat-shrinkable film heat treatment device 1 according to the first embodiment of the present disclosure, the heat-shrinkable film F may be heated only by a mixed gas containing the water vapor. In other words, the heat-shrinkable film 1 does not need to include a preheating chamber for preheating the article G and the heat-shrinkable film F. The heat-shrinkable film 1 may further include the above-mentioned preheating chamber. Note that in the drawings, the mixed gas and the flow of the mixed gas are schematically indicated by the symbol "GM."

[0017] The article G and heat-shrinkable film F applicable to the heat-shrinkable film heating treatment device 1 according to this embodiment are not particularly limited. The article G is, for example, a self-supporting rigid container, and may be, for example, a glass bottle, a blow-molded resin bottle such as a PET bottle, or a metal can. However, the heat-shrinkable film FS after heat-shrinking in the heat-shrinkable film heating treatment device 1 according to this embodiment may be a full shrink label that covers the entire article G, or a shrink label that covers only the body of the article G.

[0018] The heat-shrinkable film F is, for example, a shrink label processed into a cylindrical shape. The heat-shrinkable film F is placed on the outer periphery of the article G and is placed in the heat treatment device 1 together with the article G.

[0019] Specifically, the heat-shrinkable film F is a cylindrical shrink label with a product name, a design, etc. printed on the inner surface. Typical materials for the heat-shrinkable film F include polyolefin resins, polyester resins, polystyrene resins, and mixed resins thereof. The heat-shrinkable film is a single-layer or multi-layer film with a thickness of 15 μm to 80 μm, which has a shrinkage rate of 30% to 80% when immersed in hot water at 90°C for 10 seconds in the circumferential direction of the cylindrical shape.

[0020] The heat-treating apparatus 1 for heat-shrinkable film F according to embodiment 1 of the present disclosure includes a conveying mechanism 10, a processing chamber 20, a water vapor supply section 30, a first path 40, a reheating device 50, an air supply section 60, a gas ejection section 70, and a second gas ejection section 80.

[0021] The conveying mechanism 10 is configured to convey articles G covered with a heat-shrinkable film F. The conveying mechanism 10 conveys a plurality of articles G placed on the conveying mechanism 10 in one direction (conveying direction DT). In this embodiment, the conveying direction DT is a linear direction that is perpendicular to the up-down direction. In each drawing, the upper side is indicated by the symbol "U" and the lower side is indicated by the symbol "D".

[0022] In the process of conveying the article G provided with the heat-shrinkable film F in the conveying direction DT in the conveying mechanism 10, the heat-shrinkable film F shrinks, and the shrunk heat-shrinkable film FS covers a portion of the article G. The conveying mechanism 10 is a so-called top chain conveyor, but may also be a belt conveyor.

[0023] An object G covered with a heat-shrinkable film F before shrinking is placed in the processing chamber 20. Specifically, a transport mechanism 10 is located in the processing chamber 20. In the processing chamber 20, the object G is placed on the transport mechanism 10. The heat-shrinkable film F covering the object G is also placed on the transport mechanism 10.

[0024] The processing chamber 20 includes an outer wall 21 and an exhaust section 22. The outer wall 21 generally covers the object G on the transfer mechanism 10 within the processing chamber 20. However, the interior of the outer wall 21 does not have to be an airtight space. The outer wall 21 may be provided with a load entrance 211 and an unload entrance 212. A portion of the transfer mechanism 10 opposite to the end portion in the transfer direction DT may extend from the load entrance 211 to the outside of the processing chamber 20. A portion of the transfer mechanism 10 at the end of the transfer direction DT may extend from the unload entrance 212 to the outside of the processing chamber 20.

[0025] The exhaust unit 22 is provided on the outer wall 21 above the transfer mechanism 10 inside the processing chamber 20. The exhaust unit 22 is configured to be able to suck in and exhaust gas inside the outer wall 21.

[0026] The water vapor supply unit 30 typically supplies water vapor generated by heating water. The water vapor supply unit 30 may be a device that generates water vapor, such as a boiler. The water vapor supply unit 30 preferably supplies saturated water vapor. However, the water vapor supply unit 30 may also supply heated air containing water vapor with a significantly high relative humidity, but not 100% RH. The water vapor supply unit 30 is disposed outside the processing chamber 20. The water vapor supply unit 30 may also be a supply member to which a large boiler different from the heat processing apparatus 1 is connected. The supply member includes, for example, a pipe. In this case, the above-mentioned water vapor generated by the large boiler is supplied through the pipe (water vapor supply unit).

[0027] One end of the first path 40 is disposed within the processing chamber 20. The other end of the first path 40 is connected to the water vapor supply unit 30. The first path 40 allows the water vapor supplied from the water vapor supply unit 30 to flow into the processing chamber 20. More specifically, the first path 40 allows a mixed gas of water vapor and heated air to flow into the processing chamber 20.

[0028] The first path 40 includes a first side wall portion 41 , a second side wall portion 42 , a branch portion 43 , an insertion pipe 45 , a straight portion 46 , an elbow portion 47 , a steam introduction pipe 48 , and a valve 49 .

[0029] The first side wall 41 is horizontally adjacent to a passage region R, which is a region within the processing chamber 20 through which the heat-shrinkable film F passes as the article G is transported by the transport mechanism 10. The first side wall 41 and the passage region R are adjacent to each other in a direction perpendicular to the transport direction DT. The first side wall 41 extends approximately parallel to the transport direction DT. The interior of the first side wall 41 is hollow. Water vapor, specifically the above-mentioned mixed gas, flows through the interior of the first side wall 41.

[0030] The first side wall portion 41 is incorporated into the gas ejection portion 70. The first side wall portion 41 may be configured to be included in the gas ejection portion 70. Details of the configuration of the first side wall portion 41 will be described together with the gas ejection portion 70.

[0031] The second side wall 42 is adjacent to the passage region R in the horizontal direction within the processing chamber 20. The second side wall 42 and the passage region R are adjacent to each other in a direction perpendicular to the transport direction DT. The second side wall 42 extends parallel to the transport direction DT. The interior of the second side wall 42 is hollow. Water vapor, specifically the above-mentioned mixed gas, flows through the interior of the second side wall 42. The second side wall 42 is located on the opposite side of the passage region R from the first side wall 41.

[0032] The second side wall portion 42 is incorporated into the second gas ejection portion 80. The second side wall portion 42 may be configured to be included in the second gas ejection portion 80.

[0033] When the heat-shrinkable film F is heat-shrunk in the heat treatment device 1, the maximum temperature between the first side wall portion 41 and the second side wall portion 42 may be, for example, about 70° C. or higher. In addition, at this time, the maximum relative humidity between the first side wall portion 41 and the second side wall portion 42 is preferably 100% RH.

[0034] The temperature of the internal space of the first side wall portion 41 and the second side wall portion 42 may be, for example, 150°C or higher and 500°C or lower, preferably 150°C or higher and 400°C or lower, and more preferably 150°C or higher and 300°C or lower.

[0035] The branching portion 43 is connected to the first hole 412 of the first side wall portion 41, the second hole 422 of the second side wall portion 42, and the insertion pipe 45. The water vapor in the insertion pipe 45, specifically the mixed gas, flows into the first side wall portion 41 and the second side wall portion 42 via the branching portion 43, the first hole 412, and the second hole 422. In the present embodiment, the first hole 412 and the second hole 422 are provided on the upper side of the first side wall portion 41 and the second side wall portion 42, respectively.

[0036] The insertion pipe 45 is connected to the branch portion 43 and the straight portion 46. The insertion pipe 45 is inserted into the processing chamber 20 from the external space of the processing chamber 20.

[0037] The straight portion 46 is a pipe that extends linearly. In this embodiment, the straight portion 46 extends vertically. The insertion pipe 45 is connected to the upper end of the straight portion 46. The elbow portion 47 is connected to the lower end of the straight portion 46.

[0038] The elbow portion 47 is a pipe connected to the straight portion 46 between the straight portion 46 and the steam supply portion 30. The elbow portion 47 is bent.

[0039] The steam inlet pipe 48 is connected to the elbow portion 47 and the steam supply unit 30. The steam supply unit 30 causes steam to flow from the steam inlet pipe 48 into the first path 40. That is, the steam supplied from the steam supply unit 30 flows through the steam inlet pipe 48, the elbow portion 47, the straight portion 46, the insertion pipe 45, the branch portion 43, and the first side wall portion 41 and the second side wall portion 42, in this order.

[0040] The valve 49 is provided on the steam introduction pipe 48. By adjusting the opening of the valve 49, the amount of steam flowing into the processing chamber 20 can be adjusted.

[0041] The reheating device 50 is configured to heat a mixed gas GM of steam supplied from the steam supply unit 30 and air supplied from the air supply unit 60. The reheating device 50 is provided in the first path 40. Specifically, the reheating device 50 is provided in the straight section 46. The reheating device 50 further heats the steam flowing through the first path 40, specifically the mixed gas GM.

[0042] The reheating device 50 is not particularly limited as long as it is a device capable of heating the water vapor (gas mixture) flowing through the straight section 46 of the first path 40. The reheating device 50 may be, for example, a superheater of an electromagnetic induction heating type. The reheating device 50, which is a superheater, includes a coil 51 and a heating element 52. The coil 51 is provided outside the straight section 46. The heating element 52 is provided inside the straight section 46. The heating element 52 includes, for example, multiple stainless steel plates stacked on top of each other. When a current is passed through the coil 51, an eddy current is generated in the heating element 52, causing the heating element 52 to generate heat. When the gas flowing through the straight section 46 comes into thermal contact with the heating element 52, the temperature of the gas increases.

[0043] The temperature of the water vapor (gas mixture) immediately after being heated by the reheating device 50 may be, for example, 180° C. or higher and 450° C. or lower. The temperature of the water vapor (gas mixture) immediately after being heated by the reheating device 50 is preferably 200° C. or higher, and more preferably 250° C. or higher.

[0044] The air supply unit 60 is connected to a portion of the first path 40 between the steam supply unit 30 and the reheating device 50. Specifically, the air supply unit 60 is connected to the elbow portion 47. The air supply unit 60 supplies compressed air to the first path 40, thereby mixing the air with the steam flowing through the first path 40.

[0045] The air supply unit 60 includes a compressor 61, a second path 62, and a regulator 63. In this embodiment, the compressor 61 generates compressed air by compressing air. The compressor 61 is only required to generate compressed air at 0.1 MPa or higher. Therefore, in this embodiment, the compressor 61 is different from a so-called single fan or single blower. The specific type of the compressor 61 is not particularly limited. The compressor 61 may be a positive displacement compressor or a turbo compressor. However, the air supply unit 60 may supply uncompressed air. The air supply unit 60 may include an air delivery device such as a single fan or a single blower instead of the compressor 61. Note that when a fan or blower that does not provide high compression is used, the air pressure may be 0.005 MPa or higher.

[0046] The second path 62 is connected to the compressor 61 and the first path 40. Specifically, the second path 62 is connected to the elbow portion 47 of the first path 40. The second path 62 causes the compressed air generated by the compressor 61 to flow to the first path 40 (elbow portion 47).

[0047] A portion 621 of the second path 62 connected to the elbow portion 47 overlaps the internal space of the straight portion 46 when viewed from the direction of extension of the straight portion 46 and extends along the direction of extension. The portion 621 is made of a synthetic material such as metal or resin, and is specifically a substantially cylindrical connector. The central axis of the portion 621 extends along the direction of extension.

[0048] The regulator 63 is provided in the second path 62. The regulator 63 adjusts the gauge pressure of the compressed air on the secondary side to 0.1 MPa or higher relative to the high-pressure compressed air on the primary side. The regulator 63 may adjust the gauge pressure of the compressed air on the secondary side to less than 0.6 MPa (less than 0.3 MPa is particularly preferable). The type of regulator 63 is not particularly limited. The regulator 63 may be a regulator with an air filter or a regulator without an air filter.

[0049] The air taken in by the compressor 61 is ambient air at room temperature around the compressor 61. Furthermore, the heat treatment device 1 according to this embodiment does not include a heat generating device for heating the gas flowing through the second path 62. Therefore, the compressed air is at room temperature immediately before being supplied to the first path 40 by the air supply unit 60.

[0050] The "room temperature" which is the temperature of the compressed air immediately before it is supplied to the first path 40 by the air supply unit 60 is, for example, preferably 70°C or less, more preferably 50°C or less, and even more preferably 40°C or less. The temperature of the compressed air immediately before it is supplied to the first path 40 by the air supply unit 60 is room temperature, and is therefore lower than the temperature of the water vapor generated by the water vapor supply unit 30. Note that when air is supplied by the fan or blower instead of compressed air, air at a moderate temperature, not limited to room temperature, or air mixed with water vapor may be supplied, or air heated to 100°C or higher, for example, about 150°C, may be supplied.

[0051] Fig. 3 is a diagram partially showing the heat treatment device when the gas ejection section is viewed from the passing region. Fig. 4 is a partial cross-sectional view of the heat treatment device of Fig. 2 when viewed in the direction of the arrows IV-IV. As shown in Figs. 1 to 4, the gas ejection section 70 is configured to eject the mixed gas GM heated by the reheating device 50 toward the heat-shrinkable film F that is passing through the passing region R as the article G is conveyed by the conveying mechanism 10.

[0052] The gas ejection part 70 includes a plurality of facing surface parts 71 , a plurality of slits 72 , a plurality of lower gas ejection holes 73 , and a flow regulating plate 75 .

[0053] The multiple opposing surface portions 71 include one or more first opposing surface portions 71A, one or more second opposing surface portions 71B, and one or more third opposing surface portions 71C. The one or more first opposing surface portions 71A are adjacent to one another in the conveying direction DT. The one or more third opposing surface portions 71C are adjacent to one another in the conveying direction DT. The one or more second opposing surface portions 71B are located between the one or more first opposing surface portions 71A and the one or more third opposing surface portions 71C in the conveying direction DT. The one or more third opposing surface portions 71C are arranged on the most upstream side of the multiple opposing surface portions 71 in the conveying direction DT.

[0054] The opposing surface portion 71 is disposed so as to face the passage region R. The multiple opposing surface portions 71 are positioned so as to cover the multiple first openings 415 that open in the first side wall portion 41 toward the passage region R. The opposing surface portions 71 are attached to the first side wall portion 41 so that their positions relative to the first side wall portion 41 can be changed. The thickness of the opposing surface portion 71, i.e., the dimension of the opposing surface portion 71 in the facing direction DO1, is 3 mm to 30 mm, and preferably 5 mm to 20 mm.

[0055] Fig. 5 is a partial cross-sectional view of the heat treatment apparatus of Fig. 3, as viewed in the direction of the arrow VV line. As shown in Figs. 1 to 5, the facing surface portion 71 includes a facing surface 711 and an opposite surface 712.

[0056] The facing surface 711 faces the passage region R. The opposite surface 712 is located opposite the facing surface 711. The facing surface 711 and the opposite surface 712 extend parallel to the conveying direction DT. The facing surface 711 and the opposite surface 712 extend in the up-down direction. As described above, in this embodiment, the facing surface portion 71 is a plate-shaped member.

[0057] The plurality of slits 72 are formed in each of the plurality of opposing surface portions 71. The mixed gas GM passes through the slits 72 and is ejected into the passage region R. Specifically, the plurality of slits 72 are formed in each of one or more first opposing surface portions 71A and one or more second opposing surface portions 71B. In this embodiment, the plurality of slits 72 are not provided in one or more third opposing surface portions 71C.

[0058] Each of the plurality of slits 72 extends in the vertical direction. This allows the mixed gas GM to be applied relatively uniformly to the articles G and the heat-shrinkable film F moving in the conveyance direction DT, which is perpendicular to the vertical direction.

[0059] The lower end of each of the slits 72 is aligned in the facing direction DO1 with the placement surface on which the multiple articles G are placed in the conveying mechanism 10, or is located below the placement surface (see FIG. 4). The facing direction DO1 is the direction in which the facing surface portion 71 faces the passage region R. The upper and lower end positions of each of the multiple slits 72 may be adjusted based on the shape of the articles G, the vertical length of the heat-shrinkable film F, and the attachment position relative to the articles G. For this reason, some of the facing surface portions 71A may be replaced with ones of a different shape.

[0060] In each of the one or more first opposing surface portions 71A, the upper ends of the plurality of slits 72 are provided so as to be positioned above the plurality of articles G and the heat-shrinkable film F (see FIG. 3). In each of the one or more first opposing surface portions 71A, the upper ends of the plurality of slits 72 are aligned with each other in the horizontal direction.

[0061] In the second opposing surface portion 71B, the upper end of one of the plurality of slits 72 may be located lower than the upper ends of the other slits 72 located further from the slit 72 in the transport direction DT.

[0062] The positions of the plurality of slits 72 can be easily changed by changing the relative position of the facing surface portion 71 with respect to the first side wall portion 41. The plurality of slits 72 are preferably located inside the first opening 415 when viewed from the facing direction DO1 (see FIG. 3).

[0063] The slit 72 includes a first guide surface 721 and a second guide surface 722 (see FIG. 5 ). The first guide surface 721 connects the opposing surface 711 and the opposite surface 712. The second guide surface 722 connects the opposing surface 711 and the opposite surface 712. The second guide surface 722 faces the first guide surface 721 in the conveying direction DT, which is the direction in which the conveying mechanism 10 conveys the article G.

[0064] The first guide surface 721 and the second guide surface 722 are inclined toward the conveying direction DT from the opposite surface 712 toward the opposing surface 711. The first guide surface 721 and the second guide surface 722 preferably partially overlap when viewed from the opposing direction DO1. This makes it easier for the mixed gas GM to be ejected along the surface direction of the first guide surface 721 and the second guide surface 722. When viewed from above, the ejection direction of the mixed gas GM is preferably inclined at an angle of 30 to 60 degrees with respect to the conveying direction DT, and most preferably at an angle of substantially 45 degrees.

[0065] The first guide surface 721 includes a parallel surface 725 and a notched surface 726. The parallel surface 725 extends from the opposite surface 712. The parallel surface 725 extends parallel to the second guide surface 722. The notched surface 726 extends from the opposing surface 711 and is connected to the parallel surface 725. The notched surface 726 is formed such that the opposing direction DO1 side of the parallel surface 725 is notched when viewed from the top-bottom direction. This prevents the mixed gas GM ejected along the parallel surface 725 from spreading as if pulled from the parallel surface 725 along the opposing surface 711. The angle a of a corner 727, which is the portion where the parallel surface 725 and the notched surface 726 are connected, when viewed from the top-bottom direction is preferably 100 degrees or less, and more preferably 90 degrees or less.

[0066] The slit width of the slit 72 is, for example, 1 mm or more and 10 mm or less. The slit width is preferably 2 mm or more and 8 mm or less. Specifically, the slit width is the distance between the first guide surface 721 and the second guide surface 722. The vertical length of the slit 72 is, for example, 10 mm or more and 200 mm or less. The vertical length of the slit 72 is preferably, for example, 20 mm or more. The vertical length of the slit 72 is preferably 150 mm or less.

[0067] The first guide surface 721 and the second guide surface 722 do not necessarily have to be inclined in the conveying direction DT from the opposite surface 712 toward the opposing surface 711. The first guide surface 721 and the second guide surface 722 may be inclined in the opposite direction of the conveying direction DT from the opposite surface 712 toward the opposing surface 711. It is preferable that the slits 72 including the first guide surface 721 and the second guide surface 722 inclined in the opposite direction be arranged in a part of the multiple slits 72 other than the first slit on the upstream side in the conveying direction DT.

[0068] Fig. 6 is a partial cross-sectional view of the heat treatment device of Fig. 2, as viewed in the direction of the arrows VI-VI. As shown in Figs. 1 to 3 and 6, the lower gas ejection holes 73 are located in the opposite direction from the conveying direction DT, which is the direction in which the conveying mechanism 10 conveys the articles G, as viewed from the slit 72.

[0069] The plurality of lower gas ejection holes 73 are provided in each of the one or more third opposing surface portions 71C (see FIG. 3). In each of the one or more third opposing surface portions 71C, the plurality of lower gas ejection holes 73 are arranged adjacent to one another in the transport direction DT. In each of the one or more third opposing surface portions 71C, the plurality of lower gas ejection holes 73 are positioned so as to overlap with the first openings 415 in the opposing direction DO1.

[0070] The lower gas ejection holes 73 face the passage region R and are inclined downward D so that the mixed gas GM passes through the lower gas ejection holes 73 and is ejected toward the downward direction D of the passage region R (see FIG. 6 ). Specifically, the lower gas ejection holes 73 are inclined downward D from the opposite surface 712 of each of the one or more third opposing surface portions 71C toward the opposing surface 711. In this embodiment, the placement surface of the articles G in the conveying mechanism 10 is located on an imaginary extension line of the lower gas ejection holes 73 from the opposite surface 712 toward the opposing surface 711. This allows the mixed gas GM ejected from the lower gas ejection holes 73 to more reliably collide with the underside of the articles G and the heat-shrinkable film F along the placement surface of the conveying mechanism 10.

[0071] The diameter of the lower gas ejection holes 73 is, for example, 1 mm or more and 10 mm or less. The diameter of the lower gas ejection holes 73 is preferably 2 mm or more. The diameter of the lower gas ejection holes 73 is preferably 8 mm or less. Each of the multiple lower gas ejection holes 73 is a circular hole, but is not limited to this and may be an elongated hole (an oval or short slit-shaped hole) that is long in the transport direction DT. When the lower gas ejection holes 73 are circular holes, an imaginary extension line of the lower gas ejection holes 73 extending from the opposite surface 712 toward the facing surface 711 may be inclined downstream in the transport direction DT.

[0072] Fig. 7 is a partial cross-sectional view of the heat treatment apparatus of Fig. 2 as viewed in the direction of the arrows VII-VII. As shown in Figs. 4, 6, and 7, the current plate 75 is located on the opposite side of the facing surface portion 71 from the passage region R. The current plate 75 overlaps with the plurality of slits 72 and the plurality of lower gas ejection holes 73 in the facing direction DO1.

[0073] The rectifying vane 75 is provided inside the first side wall portion 41. The rectifying vane 75 is provided so as to block the shortest path between the first hole portion 412 and the plurality of first openings 415. Specifically, the rectifying vane 75 extends from the upper end to the lower end inside the first side wall portion 41. The first side wall portion 41 extends so as to be inclined with respect to the up-down direction.

[0074] The rectifying plate 75 has one or more cutout portions 751 formed therein. Each of the one or more cutout portions 751 is formed on the lower edge of the rectifying plate 75. The mixed gas GM passes through the one or more cutout portions 751, thereby being able to flow from the first hole portion 412 to the plurality of first openings 415 (see FIG. 4 , etc.).

[0075] Furthermore, each of the one or more cutouts 751 extends in the transport direction DT (see FIG. 7). When viewed from the facing direction DO1, each of the one or more cutouts 751 is arranged so as not to be aligned with the first hole 412 in the up-down direction. This allows the mixed gas GM that flows into the first side wall 41 from the first hole 412 to be diffused more uniformly in the transport direction DT and the opposite direction thereto.

[0076] In the present embodiment, due to the above-described configuration, the mixed gas GM is ejected toward the passage region R from the side opposite the opposing surface portion 71 as seen from the rectifying plate 75, by bypassing the rectifying plate 75 and passing through the slits 72. However, the configuration of the rectifying plate 75 is not limited to the above.

[0077] The second gas ejection part 80 and the second side wall part 42 can have the same configuration as the gas ejection part 70 and the first side wall part 41, respectively, except that the opposing direction of the opposing surfaces is the second opposing direction DO2. The second opposing direction DO2 is the opposite direction to the opposing direction DO1.

[0078] As described above, the heat treatment device 1 for a heat shrinkable film F according to the first embodiment of the present disclosure includes a conveying mechanism 10, a water vapor supply unit 30, an air supply unit 60, a reheating device 50, and a gas ejection unit 70. The conveying mechanism 10 is configured to convey an article G covered with a heat shrinkable film F. The reheating device 50 is configured to heat a mixed gas GM of water vapor supplied from the water vapor supply unit 30 and air supplied from the air supply unit 60. The gas ejection unit 70 is configured to eject the mixed gas GM heated by the reheating device 50 toward the heat shrinkable film F that is passing through the passage region R as the article G is conveyed by the conveying mechanism 10. The gas ejection unit 70 includes an opposing surface 71 and a slit 72. The opposing surface 71 is disposed to face the passage region R. The slit 72 is formed in the opposing surface 71. The mixed gas GM is ejected into the passage region R by passing through the slit 72.

[0079] According to the above configuration, compared to when the mixed gas GM is sprayed from a plurality of round holes or a plurality of scattered nozzles, when the mixed gas GM passes through the slit 72 and reaches the passage region R of the heat-shrinkable film F, it is sprayed from the entire vertical direction of the slit 72 without diffusing significantly in the width direction of the slit 72. As a result, the mixed gas GM hits the heat-shrinkable film F with force in the vertical direction, thereby suppressing the occurrence of uneven shrinkage.

[0080] Moreover, in this embodiment, the gas ejection part 70 further includes a rectifying plate 75. The rectifying plate 75 is located on the opposite side of the facing surface part 71 from the passage region R. The rectifying plate 75 overlaps with the slits 72 in the facing direction DO1 in which the facing surface part 71 faces the passage region R. The mixed gas GM is ejected toward the passage region R from the opposite side of the facing surface part 71 from the rectifying plate 75, by bypassing the rectifying plate 75 and passing through the slits 72.

[0081] According to the above configuration, the rectifying plate 75 can prevent the mixed gas GM from being locally ejected from a portion of the slit 72 that is close to the portion where the mixed gas GM is supplied to the gas ejection portion 70. Furthermore, the mixed gas GM is dispersed toward the entire slit 72 and ejected from the entire slit 72 toward the heat-shrinkable film, thereby further preventing uneven shrinkage of the heat-shrinkable film F.

[0082] In this embodiment, the opposing surface portion 71 includes an opposing surface 711 and an opposite surface 712. The opposing surface 711 faces the passage region R. The opposite surface 712 is located opposite the opposing surface 711. The slit 72 includes a first guide surface 721 and a second guide surface 722. The first guide surface 721 connects the opposing surface 711 and the opposite surface 712. The second guide surface 722 connects the opposing surface 711 and the opposite surface 712. The second guide surface 722 faces the first guide surface 721 in the conveying direction DT, which is the direction in which the conveying mechanism 10 conveys the item G. The first guide surface 721 and the second guide surface 722 are inclined in the conveying direction DT from the opposite surface 712 toward the opposing surface 711.

[0083] According to the above configuration, the mixed gas GM can also be applied to the rear side of the heat-shrinkable film F in the conveying direction DT, further suppressing uneven shrinkage of the heat-shrinkable film F. Furthermore, the ejection direction of the mixed gas GM is controlled by the shape of the slit 72 without attaching a blade member extending obliquely toward the conveying direction DT to the gas ejection unit 70, so the gas ejection unit 70 can be positioned close to the passing region R. Consequently, the temperature drop of the ejected mixed gas GM until it reaches the heat-shrinkable film F can be suppressed. Furthermore, the mixed gas GM only hits the front side (the conveying direction DT side) of the heat-shrinkable film F on the upstream side in the conveying direction DT, suppressing early shrinkage of the front side of the heat-shrinkable film F. Typically, the heat treatment device 1 may be designed so that the front and rear sides of the heat-shrinkable film F shrink at substantially the same time by strongly blowing the mixed gas GM and heating it in a short time.

[0084] Moreover, in this embodiment, the gas ejection unit 70 further includes lower gas ejection holes 73. The lower gas ejection holes 73 are located in the opposite direction from the conveying direction DT, which is the direction in which the conveying mechanism 10 conveys the articles G, as viewed from the slit 72. The lower gas ejection holes 73 face the passage region R and are inclined downward D so that the mixed gas GM passes through the lower gas ejection holes 73 and is ejected toward the downward direction D of the passage region R.

[0085] According to the above configuration, before the mixed gas GM is ejected from the slit 72, the lower side of the heat-shrinkable film F passing through the passage region R is heated in advance, so that only the lower side can be heat-shrunk first. For example, if the article G has a curved lower end side surface G5 (see FIG. 6), the heat-shrinkable film F can be wrapped around the lower end side surface G5 more reliably. Consequently, the heat-shrinkable film F can be heat-shrunk by the mixed gas GM ejected from the slit 72 while suppressing misalignment of the heat-shrinkable film F with respect to the article G.

[0086] Furthermore, it is particularly preferable that the lower gas ejection holes 73 are inclined downward D so that the mixed gas GM passes through the lower gas ejection holes 73 and is ejected toward the placement surface of the articles G in the conveying mechanism 10. This prevents the mixed gas GM passing through the lower gas ejection holes 73 from directly hitting the heat-shrinkable film F, allowing the lowermost part of the heat-shrinkable film F to be heated evenly.

[0087] (Modifications) Modifications of the first embodiment of the present disclosure will now be described. Fig. 8 is a cross-sectional view showing a modification of the rectifying plate and the first side wall portion, etc. Fig. 8 shows a cross-sectional view corresponding to Fig. 4 of the above embodiment. As shown in Fig. 8, the first hole portion 412a may be provided on the lower side of the first side wall portion 41. In this case, one or more notches 751a are formed on the upper edge of the rectifying plate 75.

[0088] Fig. 9 is a cross-sectional view showing another modified example of the first side wall portion. Fig. 9 shows a cross-sectional view corresponding to Fig. 4 of the above embodiment. As shown in Fig. 9, the first hole portion 412b may be provided so as to face the plurality of first openings 415 in the facing direction DO1.

[0089] Fig. 10 is a cross-sectional view showing yet another modified example of the first side wall portion. Fig. 10 shows a cross-sectional view corresponding to Fig. 7 of the above embodiment. As shown in Fig. 10, the first hole portion 412c may be provided on the side surface of the first side wall portion 41 facing the conveying direction DT. The first hole portion 412c may be provided on the side surface of the first side wall portion 41 facing the opposite direction to the conveying direction DT.

[0090] FIG. 11 is a cross-sectional view showing a modified example of the slit. FIG. 11 shows a cross-sectional view corresponding to FIG. 5 of the above embodiment. As shown in FIG. 11, the first guide surface 721a and the second guide surface 722a may extend along the facing direction DO1. The gas ejection unit 70 may further include a blade member 77. The blade member 77 extends from the facing surface 711 so as to incline toward the conveying direction DT as it moves toward the facing direction DO1. This allows the mixed gas GM to be applied to the rear side of the heat-shrinkable film F in the conveying direction DT. However, because the blade member 77 is provided, it is more difficult to arrange multiple facing surface portions 71 near the passing region R than in the above embodiment.

[0091] 12 is a view of a third opposing surface portion according to a modified example, viewed from the opposing direction. As shown in FIG. 12, a plurality of slits 72b may be provided above the plurality of lower gas ejection holes 73. The plurality of slits 72b may have the same configuration as the plurality of slits 72 in the first opposing surface portion 71A.

[0092] 13 is a diagram schematically illustrating a modified example of the first path and the air supply unit. As shown in FIG. 13, the steam inlet pipe 48a may be connected to extend obliquely downward from the lower end of the straight section 46. The second path 62a may be connected to extend obliquely downward from the connection between the steam inlet pipe 48a and the straight section 46.

[0093] 14 is a diagram schematically illustrating another modified example of the first path and the air supply unit. As shown in FIG. 14, the straight section 46b extends horizontally (perpendicular to the up-down direction). The steam inlet pipe 48b extends downward from the elbow section 47. The second path 62b extends diagonally downward from the steam inlet pipe 48b.

[0094] Fig. 15 is a diagram showing the overall configuration of a heat treatment apparatus according to a modified example, and Fig. 16 is a perspective view showing a part of the heat treatment apparatus of Fig. 15.

[0095] As shown in Figures 15 and 16, the article G to which the heat-shrinkable film F is attached in the heat treatment device 1x according to the modified example has a body G1, a shoulder G2, and a mouth G3. The body G1 is a portion that mainly contains the contents. A paper label P may be provided on the body G1. The shoulder G2 extends from the body G1 while reducing in diameter. The mouth G3 is provided on the opposite side of the shoulder G2 from the body G1. The mouth G3 is provided with a spout through which the contents of the article G can be poured out.

[0096] In this modification, the heat-shrinkable film FS after heat shrinkage functions as a so-called cap seal for the article G. The heat-shrinkable film F before shrinkage is placed on the mouth G3 and is engaged with a part of the mouth G3. The heat-shrinkable film FS shrunk by the heat treatment device 1x deforms to fit the outer surface of the mouth G3 (see FIG. 16 ). Therefore, the passage area R of the heat-shrinkable film F is located above and away from the conveying mechanism 10.

[0097] In this modification, the gas ejection part 70 further includes a guide plate 78. The guide plate 78 extends from the facing surface part 71x in the facing direction DO1 below the plurality of lower gas ejection holes 73 (see FIG. 16 ). This allows the mixed gas GM ejected from the lower gas ejection holes 73 to more reliably collide with the lower side (lowermost part) of the heat-shrinkable film F along the guide plate 78, even when the passing region R is spaced upward from the conveying mechanism 10.

[0098] In this modified example, the opposing surface portion 71x is formed integrally with the first side wall portion 41. The plurality of slits 72x correspond to the plurality of slit-shaped first nozzles 411 formed directly in the first side wall portion 41.

[0099] (Embodiment 2) Next, a heat treatment device for a heat shrinkable film according to embodiment 2 of the present disclosure will be described. In the following description of the embodiment, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and description thereof will not be repeated.

[0100] FIG. 17 is a diagram showing the overall configuration of a heat-shrinkable film heat treatment device according to embodiment 2. FIG. 18 is a perspective view showing a portion of the heat-shrinkable film heat treatment device according to embodiment 2. As shown in FIGS. 17 and 18 , the heat-shrinkable film heat treatment device 1s according to embodiment 2 of the present disclosure is an apparatus that uses superheated steam to heat and shrink a heat-shrinkable film F, thereby covering a portion or all of an article G with the shrunk heat-shrinkable film FS. In this embodiment, the heat-shrinkable film FS covers a portion of the article G. Note that in the heat-shrinkable film heat treatment device 1s according to embodiment 2 of the present disclosure, the heat-shrinkable film F may be heated only by a gas mixture containing the superheated steam. In other words, the heat treatment device 1s does not need to include a preheating treatment chamber for preheating the article G and the heat-shrinkable film F. The heat treatment device 1s may further include the preheating treatment chamber.

[0101] The article G and heat-shrinkable film F applicable to the heat-shrinkable film heating treatment device 1s according to this embodiment are not particularly limited. The article G is, for example, a self-supporting rigid container, such as a bottle or a plastic bottle. In this embodiment, the heat-shrinkable film FS after heat shrinkage functions as a so-called cap seal for the article G. However, the heat-shrinkable film FS after heat shrinkage in the heat-shrinkable film heating treatment device 1s according to this embodiment may be a full shrink label that covers the entire article G, or a shrink label that covers only the body of the article G.

[0102] The article G according to this embodiment has a body G1, a shoulder G2, and a mouth G3. The body G1 is the portion that mainly contains the contents. A paper label P may be provided on the body G1. The shoulder G2 extends from the body G1 while reducing in diameter. The mouth G3 is provided on the opposite side of the shoulder G2 from the body G1. The mouth G3 is provided with a spout through which the contents of the article G can be poured out.

[0103] The heat-shrinkable film F before shrinking is, for example, cylindrical. The heat-shrinkable film F is placed on the outer periphery of the mouth G3 and placed in the heat treatment device 1s together with the item G. Specifically, the heat-shrinkable film F placed on the mouth G3 before shrinking may be cylindrical. In this embodiment, the heat-shrinkable film F is engaged with a portion of the mouth G3. The heat-shrinkable film FS shrunk by the heat treatment device 1s deforms to fit the outer surface of the mouth G3 (see FIG. 18 ). At this time, it is preferable that water droplets do not adhere to the body G1 and shoulder G2. By preventing water droplets from adhering to the body G1 and shoulder G2, water absorption by the paper label P can be prevented.

[0104] The heat-shrinkable film F before shrinking is specifically a label on which a product name and the like are printed. The material of the heat-shrinkable film F before shrinking is not particularly limited as long as it has heat-shrinkability. Typical materials for the heat-shrinkable film F include polyolefin resins, polyester resins, polystyrene resins, and mixed resins thereof.

[0105] The heat-shrinkable film heat treatment device 1s includes a conveying mechanism 10s, a treatment chamber 20s, a steam generator 30s, a first path 40s, a reheating device 50s, and a compressed air supply unit 60s which is an air supply unit.

[0106] The transport mechanism 10s transports multiple articles G arranged on the transport mechanism 10s in one direction. The transport mechanism 10s includes a linear transport section 11s. The transport direction of the articles G by the linear transport section 11s is a linear direction, which is indicated by the transport direction DT in the drawings. The transport direction DT is parallel to the horizontal direction.

[0107] As the article G provided with the heat-shrinkable film F is conveyed in the conveying direction DT on the linear conveying portion 11s of the conveying mechanism 10s, the heat-shrinkable film F shrinks, and the shrunk heat-shrinkable film FS covers a portion of the article G. The conveying mechanism 10s is a so-called top chain conveyor, but may also be a belt conveyor.

[0108] An object G covered with a heat-shrinkable film F before shrinking is placed in the processing chamber 20s. Specifically, a linear transport section 11s of the transport mechanism 10s is located in the processing chamber 20s. In the processing chamber 20s, the object G is placed on the linear transport section 11s.

[0109] The processing chamber 20s includes an outer wall 21s and an exhaust section 22s. The outer wall 21s generally covers the linear transport section 11s and the article G on the linear transport section 11s. However, the interior of the outer wall 21s does not have to be an airtight space. The outer wall 21s may be provided with an inlet 211s and an outlet (not shown). A portion of the transport mechanism 10s opposite the portion in the transport direction may extend from the inlet 211s to the outside of the processing chamber 20s. A portion of the transport mechanism 10s in the transport direction may extend from the outlet to the outside of the processing chamber 20s.

[0110] The exhaust section 22s is provided on the outer wall section 21s above the linear transport section 11s. The exhaust section 22s is configured to be able to suck in and exhaust gas inside the outer wall section 21s.

[0111] The steam generator 30s typically generates steam by heating water. The steam generator 30s is, for example, a boiler. The steam generator 30s preferably generates saturated steam. However, the steam generator 30s may also generate heated air containing steam with a significantly high relative humidity, but not 100% RH. The steam generator 30s is disposed outside the processing chamber 20s.

[0112] One end of the first path 40s is disposed within the processing chamber 20s. The other end of the first path 40s is connected to the steam generator 30s. The first path 40s allows the steam generated by the steam generator 30s to flow into the processing chamber 20s. More specifically, the first path 40s allows a mixture of superheated steam and heated air to flow into the processing chamber 20s.

[0113] The first path 40s includes a first side wall portion 41s, a second side wall portion 42s, a branch portion 43s, a top plate portion 44s, an insertion pipe 45s, a straight portion 46s, an elbow portion 47s, a steam introduction pipe 48s, and a valve 49s.

[0114] The first side wall 41s is disposed approximately above the linear transport portion 11s of the transport mechanism 10s. The first side wall 41s and the transport mechanism 10s are spaced apart. The first side wall 41s extends approximately parallel to the transport direction DT. The interior of the first side wall 41s is hollow. Water vapor, specifically the above-mentioned mixed gas, flows through the interior of the first side wall 41s.

[0115] The first side wall 41s has a plurality of first nozzles 411s and a first hole 412s. The internal space of the first side wall 41s is connected to the external space via the plurality of first nozzles 411s. The water vapor, specifically the mixed gas, ejected from the plurality of first nozzles 411s collides with the heat-shrinkable film F provided on the article G being transported on the linear transport section 11s.

[0116] The multiple first nozzles 411s are formed on a surface of the first sidewall portion 41s that faces perpendicular to the conveying direction DT and parallel to the horizontal direction. The multiple first nozzles 411s are aligned in the conveying direction DT. Each of the multiple first nozzles 411s has a slit-like outer shape. This allows the temperature of the mixed gas containing water vapor ejected from the multiple first nozzles 411s to be higher than that ejected from a round-hole nozzle. Each of the multiple first nozzles 411s extends in the vertical direction. The vertical positions of the multiple first nozzles 411s are appropriately changed depending on the vertical height of the heat-shrinkable film F provided on the article G on the conveying mechanism 10s. In this embodiment, the lower ends of the multiple first nozzles 411s in the vertical direction are positioned below the lower end of the heat-shrinkable film F provided on the article G on the linear conveying portion 11s.

[0117] The lengths of the first nozzles 411s in the vertical direction may be the same or different from one another. In this embodiment, the heights of the lower ends of the first nozzles 411s in the vertical direction are the same.

[0118] The first nozzles 411s include a plurality of first short nozzles 411As and a plurality of first long nozzles 411Bs. Each of the first short nozzles 411As has a length in the up-down direction shorter than that of each of the first long nozzles 411Bs.

[0119] The multiple first short nozzles 411As are aligned in the conveying direction DT without any first long nozzles 411Bs sandwiched between them. The upper ends of the multiple first short nozzles 411As are positioned below the upper end of the heat-shrinkable film F applied to the article G on the linear conveyance portion 11s. The multiple first short nozzles 411As are positioned in the opposite direction to the conveying direction DT as viewed from the multiple first long nozzles 411Bs. This allows the heat-shrinkable film F to start shrinking from its lower portion while the article G is being conveyed in the conveying direction DT. This in turn prevents the heat-shrinkable film F from sliding downward relative to the article G during the shrinking process.

[0120] The first long nozzles 411Bs are positioned on the conveying direction DT side as viewed from the first short nozzles 411As. The number of the first long nozzles 411Bs is greater than the number of the first short nozzles 411As. The upper ends of the first long nozzles 411Bs are positioned higher in the horizontal direction than the upper end of the heat-shrinkable film F attached to the article G on the linear conveyance section 11s. This prevents uneven shrinkage of the heat-shrinkable film F due to the ejection of mixed gas from the first long nozzles 411Bs.

[0121] The first hole 412s is connected to the branch portion 43s. The internal space of the first side wall 41s communicates with the internal space of the branch portion 43s via the first hole 412s. The position where the first hole 412s is formed is not particularly limited. In the present embodiment, the first hole 412s is formed on the upper side of the first side wall 41s.

[0122] The second side wall 42s is disposed approximately above the linear transport portion 11s of the transport mechanism 10s. The second side wall 42s extends parallel to the first side wall 41s. The second side wall 42s is spaced apart from the first side wall 41s. The second side wall 42s faces the first side wall 41s in a direction perpendicular to the transport direction DT and parallel to the horizontal direction. The interior of the second side wall 42s is hollow. Water vapor, specifically the above-mentioned mixed gas, flows through the interior of the second side wall 42s.

[0123] The second side wall 42s has a plurality of second nozzles 421s and second holes 422s formed therein. The interior space of the second side wall 42s is connected to the exterior space via the plurality of second nozzles 421s. The water vapor, specifically the mixed gas, ejected from the plurality of second nozzles 421s collides with the heat-shrinkable film F provided on the article G being transported on the linear transport section 11s.

[0124] The second nozzles 421s are formed on the surface of the second side wall 42s facing the first side wall 41s. The second nozzles 421s are aligned in the transport direction DT. The second nozzles 421s are aligned in a direction perpendicular to the transport direction DT so as to correspond one-to-one to the first nozzles 411s.

[0125] Each of the second nozzles 421s has a slit-like outer shape. Each of the second nozzles 421s extends in the vertical direction. The lower end of each of the second nozzles 421s is aligned with the lower ends of the first nozzles 411s aligned in the perpendicular direction. The upper end of each of the second nozzles 421s is aligned with the upper ends of the first nozzles 411s aligned in the perpendicular direction.

[0126] The second nozzles 421s include a plurality of second short nozzles 421As and a plurality of second long nozzles 421Bs that face the first short nozzles 411As and the first long nozzles 411Bs, respectively, in the orthogonal direction.

[0127] The second hole 422s is connected to the branch portion 43s. The internal space of the second side wall 42s is in communication with the internal space of the branch portion 43s via the second hole 422s. The position at which the second hole 422s is formed is not particularly limited. In the present embodiment, the second hole 422s is formed on the upper side of the second side wall 42s.

[0128] When the heat-shrinkable film F is heat-shrunk in the heat treatment device 1s, the maximum temperature between the first side wall portion 41s and the second side wall portion 42s may be, for example, about 50°C or higher, and may be about 70°C or higher. At this time, the maximum value of the relative humidity between the first side wall portion 41s and the second side wall portion 42s is preferably 100% RH. Furthermore, at this time, the maximum value of the absolute humidity between the first side wall portion 41s and the second side wall portion 42s is preferably, for example, 100 g / m ３ It may be more than that.

[0129] The temperature of the internal space of the first side wall portion 41s and the second side wall portion 42s may be, for example, 150° C. or higher and 500° C. or lower, preferably 150° C. or higher and 400° C. or lower, and more preferably 150° C. or higher and 300° C. or lower. From the viewpoint of suppressing adhesion of water droplets to the article G, particularly the paper label P, the temperature of the internal space of the first side wall portion 41s and the second side wall portion 42s is preferably 170° C. or higher, and more preferably 200° C. or higher.

[0130] The branching portion 43s is connected to the first hole 412s in the first side wall portion 41s, the second hole 422s in the second side wall portion 42s, and the insertion pipe 45s. The water vapor in the insertion pipe 45s, specifically the mixed gas, flows into the first side wall portion 41s and the second side wall portion 42s through the branching portion 43s, the first hole 412s, and the second hole 422s.

[0131] The top plate portion 44s extends from the first side wall portion 41s to the second side wall portion 42s. The top plate portion 44s is located above the multiple first nozzles 411s and the multiple second nozzles 421s. This allows the mixed gas ejected from the multiple first nozzles 411s and the multiple second nozzles 421s to remain to a certain extent near the heat-shrinkable film F. This prevents unevenness in the finished heat-shrinkable film FS after shrinkage. It is preferable that the top plate portion 44s is located only above the multiple first long nozzles 411Bs and the multiple second long nozzles 421Bs, and not above the multiple first short nozzles 411As and the multiple first long nozzles 411Bs. The top plate portion 44s may be located only above some of the multiple first long nozzles 411Bs and some of the multiple second long nozzles 421Bs.

[0132] The insertion pipe 45s is connected to the branch portion 43s and the straight portion 46s. The insertion pipe 45s is inserted into the processing chamber 20s from the external space of the processing chamber 20s.

[0133] The straight portion 46s is a pipe that extends linearly. In this embodiment, the straight portion 46s extends vertically. The insertion pipe 45s is connected to the upper end of the straight portion 46s. The elbow portion 47s is connected to the lower end of the straight portion 46s.

[0134] The elbow portion 47s is a pipe connected to the straight portion 46s between the straight portion 46s and the steam generator 30s. The elbow portion 47s is bent.

[0135] The steam inlet pipe 48s is connected to the elbow portion 47s and the steam generator 30s. The steam generator 30s causes steam to flow from the steam inlet pipe 48s into the first path 40s. That is, the steam generated by the steam generator 30s flows through the steam inlet pipe 48s, the elbow portion 47s, the straight portion 46s, the insertion pipe 45s, the branch portion 43s, and the first and second side walls 41s, 42s, in this order.

[0136] The valve 49s is provided on the water vapor introduction pipe 48s. By adjusting the opening of the valve 49s, the amount of water vapor flowing into the processing chamber 20s can be adjusted.

[0137] The reheating device 50s is provided in the first path 40s. Specifically, the reheating device 50s is provided in the straight section 46s. The reheating device 50s further heats the steam flowing through the first path 40s, specifically the mixed gas.

[0138] The reheating device 50s is not particularly limited as long as it is a device capable of heating the steam (gas mixture) flowing through the straight section 46s of the first path 40s. The reheating device 50s may be, for example, a superheater using an electromagnetic induction heating method. The reheating device 50s, which is a superheater, includes a coil 51s and a heating element 52s. The coil 51s is provided outside the straight section 46s. The heating element 52s is provided inside the straight section 46s. The heating element 52s includes, for example, multiple stainless steel plates stacked on top of each other. When a current is passed through the coil 51s, an eddy current is generated in the heating element 52s, causing the heating element 52s to generate heat. When the gas flowing through the straight section 46s comes into thermal contact with the heating element 52s, the temperature of the gas increases.

[0139] The temperature of the water vapor (gas mixture) immediately after being heated by the reheating device 50s may be, for example, 180° C. or higher and 450° C. or lower. The temperature of the water vapor (gas mixture) immediately after being heated by the reheating device 50s is preferably 200° C. or higher, and more preferably 250° C. or higher.

[0140] The compressed air supply unit 60s is connected to a portion of the first path 40s between the steam generator 30s and the reheating device 50s. Specifically, the compressed air supply unit 60s is connected to the elbow portion 47s. The compressed air supply unit 60s supplies compressed air to the first path 40s, thereby mixing the air with the steam flowing through the first path 40s.

[0141] The compressed air supply unit 60s includes a compressor 61s, a second path 62s, and a regulator 63s. The compressor 61s generates compressed air by compressing air. The compressor 61s is only required to generate compressed air of 0.1 MPa or higher. The pressure of the compressed air is not limited to 0.1 MPa or higher and may be lower than 0.1 MPa. The compressor 61s is different from a so-called single fan or a single blower. The specific type of the compressor 61s is not particularly limited. The compressor 61s may be a positive displacement compressor or a turbo compressor.

[0142] The second path 62s is connected to the compressor 61s and the first path 40s. Specifically, the second path 62s is connected to the elbow portion 47s of the first path 40s. The second path 62s allows compressed air generated by the compressor 61s to flow to the first path 40s (elbow portion 47s).

[0143] A portion 621s of the second path 62s connected to the elbow portion 47s overlaps with the internal space of the straight portion 46s when viewed from the direction of extension of the straight portion 46s and extends along the direction of extension. The portion 621s is made of a synthetic material such as metal or resin and is specifically a substantially cylindrical connector. The central axis of the portion 621s extends along the direction of extension.

[0144] The regulator 63s is provided in the second path 62s. The regulator 63s adjusts the gauge pressure of the compressed air on the secondary side to 0.1 MPa or higher relative to the high-pressure compressed air on the primary side. The regulator 63s only needs to adjust the gauge pressure of the compressed air on the secondary side to less than 0.6 MPa. The type of the regulator 63s is not particularly limited. The regulator 63s may be a regulator with an air filter or a regulator without an air filter.

[0145] The air taken in by the compressor 61s is ambient air at room temperature around the compressor 61s. Furthermore, the heat treatment device 1s according to this embodiment does not include a heat generating device for heating the gas flowing through the second path 62s. Therefore, the compressed air is at room temperature immediately before being supplied to the first path 40s by the compressed air supply unit 60s.

[0146] The "room temperature" which is the temperature of the compressed air immediately before it is supplied to the first path 40s by the compressed air supply unit 60s is, for example, preferably 70° C. or less, more preferably 50° C. or less, and even more preferably 40° C. or less. The temperature of the compressed air immediately before it is supplied to the first path 40s by the compressed air supply unit 60s is room temperature, and is therefore lower than the temperature of the steam generated by the steam generator 30s.

[0147] As described above, the heat-shrinkable film heating treatment device 1s according to the second embodiment of the present disclosure heats and shrinks the heat-shrinkable film F, thereby covering part or all of the article G with the shrunk heat-shrinkable film FS. The heat-shrinkable film heating treatment device 1s includes a treatment chamber 20s, a steam generator 30s, a first path 40s, a reheating device 50s, and a compressed air supply unit 60s. The treatment chamber 20s holds the article G covered with the unshrunk heat-shrinkable film F. The steam generator 30s generates steam. One end of the first path 40s is disposed within the treatment chamber 20s. The other end of the first path 40s is connected to the steam generator 30s. The first path 40s flows the steam generated by the steam generator 30s into the treatment chamber 20s. The reheating device 50s is provided in the first path 40s. The reheating device 50s further heats the steam flowing through the first path 40s. The compressed air supply unit 60s is connected to a portion of the first path 40s between the steam generator 30s and the reheating device 50s. The compressed air supply unit 60s supplies compressed air to the first path 40s, thereby mixing air with the steam flowing through the first path 40s.

[0148] According to the above configuration, the air mixed with the water vapor in the first path 40s is heated by the reheating device 50s. This reheating generates a mixed gas in which the superheated water vapor and the heated air are well mixed. Although the heat capacities of the superheated water vapor and the heated air are significantly different, when this well-mixed mixed gas reaches the heat-shrinkable film F, the temperature unevenness of the mixed gas on the heat-shrinkable film F can be relatively small. Consequently, the heat-shrinkable film F can be shrunk without color unevenness or streaks. Furthermore, by supplying compressed air to the first path 40s, the flow rate of the gas in the first path 40s can be increased even if the amount of water vapor supplied from the water vapor generator 30s is restricted, for example, by the valve 49s, to prevent water droplet adhesion. Consequently, the retention of superheated water vapor in areas of the processing chamber 20s far from the article G (in this embodiment, near the multiple first nozzles 411s and multiple second nozzles 421s) can be suppressed. This allows the heat-shrinkable film FS to have a good finish after shrinkage.

[0149] Therefore, in the heat-shrinkable film heating treatment device 1s of this embodiment, it is possible to prevent water droplets from adhering to the article G covered with the heat-shrinkable film FS after shrinkage, while ensuring a good finish to the heat-shrinkable film FS after shrinkage.

[0150] The compressed air supply unit 60s includes a compressor 61s, a second path 62s, and a regulator 63s. The compressor 61s generates compressed air by compressing air. The second path 62s is connected to the compressor 61s and the first path 40s. The second path 62s allows the compressed air generated by the compressor 61s to flow into the first path 40s. The regulator 63s is provided in the second path 62s. The regulator 63s adjusts the gauge pressure of the compressed air to 0.1 MPa or higher.

[0151] According to the above configuration, compressed air with a sufficiently high pressure can be sent into the first path 40s. This more reliably increases the flow rate of the gas in the first path 40s, thereby improving the finish of the heat-shrinkable film FS after shrinkage. Note that, although the above example shows a case where the pressure of the compressed air is 0.1 MPa or more, it may also be less than 0.1 MPa.

[0152] The compressed air is at room temperature immediately before being supplied to the first path 40s by the compressed air supply unit 60s.

[0153] According to the above configuration, the temperature of the air in the first path 40s is significantly increased by the reheating device 50s. This allows the superheated steam and heated air to be agitated and mixed by utilizing the expansion of the volumes of both the steam and the air in the first path 40s. This ultimately improves the finish of the heat-shrinkable film FS after shrinkage. Furthermore, because the reheating device 50s can increase the temperature of both the steam and the air, the overall configuration of the heat treatment device 1s can be simplified.

[0154] In another aspect of the present disclosure, the first path 40s includes a straight portion 46s and an elbow portion 47s. The straight portion 46s is provided with a reheating device 50s. The straight portion 46s extends linearly. The elbow portion 47s is connected to the straight portion 46s between the straight portion 46s and the steam generator 30s. The elbow portion 47s is bent. The compressed air supply unit 60s includes a compressor 61s and a second path 62s. The compressor 61s generates compressed air by compressing air. The second path 62s is connected to the compressor 61s and the elbow portion 47s. The second path 62s flows the compressed air generated by the compressor 61s to the first path 40s. The portion of the second path 62s connected to the elbow portion 47s overlaps with the internal space of the straight portion 46s when viewed from the extending direction of the straight portion 46s, and extends along the extending direction.

[0155] If the configuration were such that compressed air was likely to collide with the straight section 46s, turbulence would occur at the point where the air collided with the straight section 46s, hindering the flow of water vapor and making the water vapor more likely to condense and form condensation. However, the above configuration can prevent compressed air flowing in from the second path 62s from colliding with the straight section 46s. Consequently, condensation can be prevented from forming in the straight section 46s.

[0156] The above description of the second embodiment of the present disclosure also substantially describes a method for heat-treating a heat-shrinkable film. That is, the method for heat-treating a heat-shrinkable film according to this embodiment includes: injecting compressed air into water vapor to generate a first gas mixture containing water vapor and air; reheating the first gas mixture to generate a second gas mixture containing superheated water vapor and heated air; and heating the unshrunk heat-shrinkable film F that is applied to an article G with the second gas mixture, thereby covering part or all of the article G with the shrunk heat-shrinkable film FS.

[0157] The heat treatment device 1s for heat-shrinkable film F according to the second embodiment of the present disclosure has the same configuration as the heat treatment device 1 for heat-shrinkable film F according to the first embodiment of the present disclosure. That is, the heat treatment device 1s includes a conveying mechanism 10s, a water vapor supply unit (see the water vapor generating device 30s), an air supply unit 60s, a reheating device 50s, and a gas ejection unit (see the first side wall 41s or the second side wall 42s). The conveying mechanism 10s is configured to convey an article G covered with a heat-shrinkable film F. The reheating device 50s is configured to heat a mixed gas GM of water vapor supplied from the water vapor supply unit and air supplied from the air supply unit 60s. The gas ejection unit is configured to eject the mixed gas GM heated by the reheating device 50s toward the heat-shrinkable film F passing through a passage area as the article G is conveyed by the conveying mechanism 10s (see FIGS. 17 and 18 ). The gas ejection portion includes an opposing surface portion and a slit (see FIG. 18). The opposing surface portion is disposed so as to face the passage region (see the first side wall portion 41s or the second side wall portion 42s in FIG. 18). The slit is formed in the opposing surface portion (see the first nozzle 411s or 421s in FIG. 18). The mixed gas GM passes through the slit and is ejected into the passage region R (see FIG. 17, etc.).

[0158] (Embodiment 3) Next, a heat treatment device according to embodiment 3 of the present disclosure will be described. The heat treatment device according to embodiment 3 differs from the above-described embodiments and modifications in the configuration of the gas ejection unit and the second gas ejection unit, etc. Note that in the following description, the same configurations and effects as those of any of the above-described embodiments or modifications may not be repeated.

[0159] Fig. 19 is a partial cross-sectional view of a heat treatment apparatus according to a third embodiment of the present disclosure. Fig. 19 shows a cross-sectional view corresponding to Fig. 4 in the first embodiment. As shown in Fig. 19, in the third embodiment of the present disclosure, the gas ejection unit 70t and the first side wall 41t are configured to be able to adjust their relative positions with respect to the conveying mechanism 10 in the opposing direction in which the opposing surface 71t faces the passage region R. This configuration makes it easy to adjust the distance between the multiple slits 72 from which the mixed gas GM is ejected and the articles G located in the passage region R. Consequently, it is easier to adjust the state of the mixed gas GM, such as the temperature of the mixed gas GM when it reaches the articles G.

[0160] 19, the position of the gas ejection unit 70t after adjustment is shown by a dashed line as an example. As shown in FIG. 19, the gas ejection unit 70t, which was not positioned above the conveying mechanism 10, can be adjusted so that it is positioned partially above the conveying mechanism 10. In this way, the opposing surface portion 71t and the multiple slits 72 can be brought even closer to the article G.

[0161] 19 , in this embodiment, the distance between the gas ejection part 70t and the second gas ejection part 80t and the distance between the first side wall part 41t and the second side wall part 42t can be adjusted to be narrower than the width of the transport mechanism 10 (the dimension in the facing direction DO1).

[0162] Specifically, by changing the fastening position of the first side wall portion 41t and the second side wall portion 42t with the branch portion 43, it is possible to adjust the relative positions of the first side wall portion 41t and the second side wall portion 42t (gas ejection portion 70t and second gas ejection portion 80t) and the transport mechanism 10, respectively.

[0163] (Embodiment 4) Next, a heat treatment device according to embodiment 4 of the present disclosure will be described. The heat treatment device according to embodiment 4 has a different guide plate configuration compared to the above-described embodiments and modifications. Note that in the following description, the same configurations and effects as those of any of the above-described embodiments or modifications may not be described repeatedly.

[0164] FIG. 20 is a partial cross-sectional view of a heat treatment apparatus according to a fourth embodiment of the present disclosure. FIG. 20 illustrates a cross-sectional view corresponding to a portion of FIG. 15 in a modified example of the first embodiment. As shown in FIG. 20 , in the fourth embodiment of the present disclosure, a guide plate 78f extends in the facing direction DO1 below the facing surface portion 71xf. The guide plate 78f is configured to be adjustable in its position relative to the facing surface portion 71xf in the facing direction DO1. This configuration facilitates bringing the guide plate 78f closer to the multiple articles G and heat-shrinkable film F on the conveying mechanism 10. Furthermore, when the position of the facing surface portion 71xf relative to the conveying mechanism 10 is adjusted to move in the facing direction DO1 (see the third embodiment), the guide plate 78f can be adjusted to move (retract) in the opposite direction from the facing direction DO1 relative to the facing surface portion 71xf, thereby preventing the guide plate 78f from contacting the multiple articles G and the heat-shrinkable film F.

[0165] The second gas ejection part 80 may further include a second guide plate 88f corresponding to the guide plate 78f of the gas ejection part 70. In the present embodiment, the second guide plate 88f of the second gas ejection part 80 may have a configuration similar to that of the guide plate 78f of the gas ejection part 70, except that the extension direction of the second guide plate 88f is the second opposing direction DO2.

[0166] (Other Modifications) Further, other modifications that can be combined with the above-described Embodiments 1 to 4 and their modifications will be described. Fig. 21 is a diagram showing the opposing surface portion of a heat treatment apparatus according to another modification. As shown in Fig. 21, in the multiple opposing surface portions 71 (specifically, the third opposing surface portion 71C), the multiple slits 72bm located above the multiple lower gas ejection holes 73 may extend to between adjacent lower gas ejection holes 73.

[0167] (Further Other Modifications) A further modification that can be combined with Embodiments 1 to 4 and the modifications will now be described. FIG. 22 is a partial cross-sectional view showing a heat treatment apparatus according to a further modification. FIG. 23 is a cross-sectional view of the heat treatment apparatus of FIG. 22 as viewed in the direction of the arrows XXIII-XXIII. As shown in FIGS. 22 and 23 , in this modification, the first hole 412n is provided on the opposite side of the first side wall 41 (gas ejection part 70) facing in the opposite direction from the facing direction DO1. The first hole 412n is provided in approximately the center of the first side wall 41 in the up-down direction. The center of the first hole 412n in the up-down direction is located above the center of the first side wall 41 in the up-down direction.

[0168] The rectifying plate 75n is bent. The rectifying plate 75n includes a bent portion 752n. The bent portion 752n is formed in a V-shape (a "L" shape in hiragana) when viewed from the conveying direction DT, and the bent portion 752n is the portion where the rectifying plate 75n is bent when viewed from the conveying direction DT. The bent portion 752n is the part of the rectifying plate 75n that is furthest from the opposing surface portion 71 and the slit 72. The bent portion 752n is located above the center of the first side wall portion 41 in the up-down direction. The bent portion 752n faces the first hole portion 412n. As a result, the flow of the mixed gas GM that flows in from the first hole portion 412n collides with the bent portion 752n and is then dispersed upward and downward. However, the shape of the bent portion 752n is not limited to a V-shape (the shape of the character "L" in hiragana) as long as it can disperse the flow of the mixed gas GM upward and downward as described above.

[0169] The rectifying plate 75n has a plurality of communication portions 753n. The communication portions 753n allow the mixed gas GM to pass between the space opposite the facing direction DO1 as viewed from the rectifying plate 75n and the space in the facing direction DO1 as viewed from the rectifying plate 75n. Specifically, the communication portions 753n are a plurality of through holes, but they may also be a plurality of notches. The communication portions 753n are provided above the bent portions 752n and below the bent portions 752n. This allows the mixed gas GM, whose flow is dispersed vertically, to reach the slit 72 and be ejected from the slit 72 as is. The communication portions 753n are also aligned in the transport direction DT. As viewed from the facing direction DO1, the communication portions 753n are positioned closer to the transport direction DT than the first holes 412n and also positioned in the opposite direction of the transport direction DT than the first holes 412n. The distance between the communication portions 753n in the transport direction DT decreases with increasing distance from the first hole portion 412n.

[0170] In this modification, a plurality of first side wall portions 41 (for example, two or three first side wall portions 41) may be arranged in series in the transport direction DT. In this case, the shapes of the slits 72 in the plurality of first side wall portions 41 may be different from each other. Furthermore, the temperatures and air volumes of the mixed gas GM ejected from the slits 72 in the plurality of first side wall portions 41 may be different from each other.

[0171] In the above-described embodiments and modifications, configurations that can be combined may be combined with each other.

[0172] The embodiments and modifications disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0173] 1, 1x, 1s Heat treatment device, 10, 10s Transfer mechanism, 11s Linear transfer section, 20, 20s Treatment chamber, 21, 21s Outer wall section, 22, 22s Exhaust section, 30 Steam supply section, 30s Steam generator, 40, 40s First path, 41, 41s, 41t First side wall section, 42, 42s, 42t Second side wall section, 43, 43s Branch section, 44s Top plate section, 45, 45s Insertion pipe, 46, 46b, 46s Straight section, 47, 47s Elbow section, 48, 48a, 48b, 48s Steam introduction pipe, 49, 49s Valve, 50, 50s Reheating device, 51, 51s Coil, 52, 52s Heating element, 60 Air supply section, 60s Compressed air supply unit, 61, 61s Compressor, 62, 62a, 62b, 62s Second path, 63, 63s Regulator, 70, 70t Gas jetting unit, 71, 71x, 71t, 71xf Opposing surface, 71A First opposing surface, 71B Second opposing surface, 71C Third opposing surface, 72, 72b, 72x, 72bm Slit, 73 Lower gas jetting hole, 75, 75n Straightening plate, 77 Blade member, 78, 78f Guide plate, 80, 80t Second gas jetting unit, 88f Second guide plate, 211, 211s Carry-in entrance, 212 Carry-out exit, 411, 411s First nozzle, 411As First short nozzle, 411Bs First long nozzle, 412, 412a, 412b, 412c, 412s, 412n First hole portion, 415 First opening portion, 421s Second nozzle, 421As Second short nozzle, 421Bs Second long nozzle, 422, 422s Second hole portion, 621, 621s Portion, 711 Opposing surface, 712 Opposite surface, 721, 721a First guide surface, 722, 722a Second guide surface, 725 Parallel surface, 726 Notched surface, 727 Corner portion, 751, 751a Notched portion, 752n Bent portion, 753n Communication portion, DO1 Opposing direction, DO2 Second opposing direction, DT Conveying direction, F, FS Heat shrinkable film, G Article, G1 Body portion, G2 Shoulder portion, G3 Mouth, G5 Bottom side, GM Mixed gas, P Paper label, R Passage area.

Claims

1. A heat-treating apparatus for heat-treating a heat-treating film, comprising: a conveying mechanism, a steam supplying unit, an air supplying unit, a reheating device, and a gas ejecting unit, wherein the conveying mechanism is configured to convey an article covered with a heat-treating film, the reheating device is configured to heat a mixed gas of steam supplied from the steam supplying unit and air supplied from the air supplying unit, and the gas ejecting unit is configured to eject the mixed gas heated by the reheating device toward the heat-treating film that is passing through a passing area as the article is conveyed by the conveying mechanism, and the gas ejecting unit includes an opposing surface and a slit, the opposing surface is arranged to face the passing area, and the slit is formed in the opposing surface, and the mixed gas is ejected into the passing area by passing through the slit.

2. A heat treatment device for heat-shrinkable films as described in claim 1, wherein the gas ejection section further includes a straightening plate, the straightening plate being located on the opposite side of the opposing surface section from the passing area, the straightening plate overlapping the slit in the opposing direction in which the opposing surface section faces the passing area, and the mixed gas is ejected toward the passing area from the opposite side of the opposing surface section from the straightening plate by bypassing the straightening plate and passing through the slit.

3. A heat treatment device for heat-shrinkable film according to claim 1 or claim 2, wherein the opposing surface portion includes an opposing surface and an opposite surface, the opposing surface facing the passage area, and the opposite surface being located opposite the opposing surface, the slit includes a first guide surface and a second guide surface, the first guide surface connecting the opposing surface and the opposite surface, the second guide surface connecting the opposing surface and the opposite surface, the second guide surface facing the first guide surface in a conveying direction in which the conveying mechanism conveys the article, and the first guide surface and the second guide surface incline in the conveying direction from the opposite surface towards the opposing surface.

4. A heat treatment device for heat-shrinkable films as described in claim 1 or claim 2, wherein the gas ejection section further includes a lower gas ejection hole, which is located in the opposite direction from the conveying direction in which the conveying mechanism conveys the article, as viewed from the slit, and the lower gas ejection hole faces the passing area and is inclined downward so that the mixed gas passes through the lower gas ejection hole and is ejected toward below the passing area.

5. A heat-shrinkable film heating treatment device as described in claim 1 or claim 2, wherein the gas ejection section is configured to be able to adjust its relative position with respect to the conveying mechanism in the opposing direction in which the opposing surface section faces the passing area.

6. A heat treatment device for heat-shrinkable films as described in claim 1 or claim 2, wherein the gas ejection section further includes a guide plate, the guide plate extending below the opposing surface section in an opposing direction in which the opposing surface section faces the passing area, and the guide plate is configured to be able to adjust its position relative to the opposing surface section in the opposing direction.

7. A heat-shrinkable film heat treatment device as described in claim 1 or claim 2, further comprising: a treatment chamber; a first path; and a compressed air supply unit, wherein the treatment chamber holds the item covered with the heat-shrinkable film before shrinking; one end of the first path is placed within the treatment chamber and the other end is connected to the water vapor supply unit, and is configured to flow water vapor supplied from the water vapor supply unit into the treatment chamber; the reheating device is provided on the first path; and the compressed air supply unit is connected to a portion of the first path between the water vapor supply unit and the reheating device, and supplies compressed air to the first path to mix the air with the water vapor flowing through the first path.

8. A heat-shrinkable film heat treatment device that heats and shrinks a heat-shrinkable film, thereby covering part or all of an article with the heat-shrinkable film after shrinkage, comprising: a treatment chamber in which the article covered with the heat-shrinkable film before shrinkage is placed; a water vapor generator that generates water vapor; a first path having one end placed in the treatment chamber and the other end connected to the water vapor generator, and through which the water vapor generated by the water vapor generator flows into the treatment chamber; a reheating device that is provided in the first path and further heats the water vapor flowing through the first path; and a compressed air supply unit that is connected to a portion of the first path between the water vapor generator and the reheating device and that supplies compressed air to the first path, thereby mixing air with the water vapor flowing through the first path.

9. A heat-treating apparatus for heat-shrinkable films as described in claim 8, wherein the compressed air supply unit includes: a compressor that generates compressed air by compressing air; a second path connected to the compressor and the first path and for causing the compressed air generated by the compressor to flow into the first path; and a regulator provided in the second path, wherein the regulator adjusts the gauge pressure of the compressed air to 0.1 MPa or more.

Images