JP2023043686A - Heat-shrinking device - Google Patents

Abstract

To provide a heat-shrinking device for a heat-shrinkable film that can save energy.SOLUTION: A heat shrinking device (1) includes: a heating chamber (2) for heat shrinking a film covering a container (10); a conveyor (3) having a mounting surface (31a) for mounting the container (10) and conveying the container (10) within the heating chamber (2); a suction duct (42) for moving air in the heating chamber (2) out of the heating chamber (2) through an opening (31b) provided in the mounting surface (31a); and a return air supply (50) for returning the air moved from the heating chamber (2) back into the heating chamber (2).SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a heat-shrinking device for heat-shrinking a heat-shrinkable film.

The heat-shrinking device shrinks the heat-shrinkable film by heating it with hot air or water vapor and brings it into close contact with the article. When the film is attached to a light object such as an empty container, the object moves from its fixed position due to the speed of the hot air or the pressure of the steam. As a countermeasure, conventionally, for example, the technique disclosed in Patent Document 1 is used. Patent Literature 1 discloses a technique for attracting articles to a conveyor by sucking air from the bottom of the conveyor. As a result, since the articles are fixed to the conveyor, it is possible to prevent the articles from moving even if the articles are exposed to hot air or steam. In Patent Document 1, the sucked air is released to the outside of the building.

U.S. Pat. No. 5,605,217

However, when the conventional technique as described above is used in the heat shrinking device, the article is fixed to the conveyor by sucking air from the lower part of the conveyor in a heating chamber in which hot air or steam is applied to the article. In that case, the heat in the heating chamber is sucked together with the air in the heating chamber, and the heat in the heating chamber is discharged to the outside of the building together with the sucked air. As a result, the temperature in the heating chamber drops, and it becomes impossible to secure the temperature necessary for finishing the adhesion of the film to the article due to heat shrinkage. For this reason, it becomes necessary to control the temperature in the heating chamber to be high, which poses a problem in terms of energy saving.

SUMMARY OF THE INVENTION It is an object of one aspect of the present invention to provide a heat-shrinking apparatus for a heat-shrinkable film that can save energy.

In order to solve the above problems, a heat shrinking apparatus according to one aspect of the present invention includes a heating chamber for heat shrinking a heat shrinkable film covering an article, and a placement surface for placing the article. a conveying section for conveying the article in the heating chamber; an inside air moving section for moving the air in the heating chamber to the outside of the heating chamber through an opening provided in the mounting surface; an inside air return unit for returning the air moved from the heating chamber to the outside of the heating chamber into the heating chamber.

According to the above configuration, the air moved from the heating chamber to the outside of the heating chamber by the inside air moving section is returned into the heating chamber by the inside air returning section. As a result, the heat in the heating chamber, which is moved together with the air in the heating chamber, can be returned to the heating chamber by the internal air return section and used for the adhesion of the film to the article by heat shrinkage, thereby realizing energy saving.

The heat-shrinking device includes a first blowing section for blowing high-temperature air onto the article, and blowing the air moved from the heating chamber to the outside of the heating chamber onto the article whose film has been heat-shrunk by the first blowing section. You may have a 2nd blowing part.

According to the above configuration, the air moved from the heating chamber to the outside of the heating chamber can be blown onto the article in which the heat-shrinkable film is heat-shrunk. As a result, the heat-shrinkable film can be pre-shrunk, and it is possible to assist the finishing of adhesion of the film to the article by heat shrinkage. In addition, since the air moved from the heating chamber to the outside of the heating chamber is blown to the article near the exit of the heating chamber, the blowing functions as an air curtain to prevent hot air from escaping from the heating chamber. can.

In the heat shrinking apparatus, the heating chamber has an entrance for the article conveyed by the conveying section to enter the heating chamber, and an entrance for the article conveyed in the heating chamber by the conveying section to exit the heating chamber. and an outlet for the inside air return unit, and the inside air returning unit may return the air moved from the inside of the heating chamber to the outside of the heating chamber to an upper portion of at least one of the inlet and the outlet.

According to the above configuration, the air moved from the heating chamber to the outside of the heating chamber flows from the upper portion to the lower portion of at least one of the inlet and the outlet, so hot air can be prevented from exiting from the inlet or the outlet of the conveying portion in the heating chamber. . As a result, the heat can be retained in the heating chamber, so that the heat utilization efficiency of the heating chamber can be improved.

In the heat shrinking device, the inside air returning section may return the air moved from the heating chamber to the outside of the heating chamber to the upper portion of the heating chamber.

According to the above configuration, by returning the air moved from the heating chamber to the outside of the heating chamber to the upper part of the heating chamber, the high-temperature air remaining in the upper part of the heating chamber is heated by the air moved from the heating chamber to the outside of the heating chamber. It can be moved to the bottom of the chamber. Thereby, the temperature in the heating chamber can be stabilized.

In the heat shrinking apparatus, the heating chamber includes a blowing portion that surrounds the article conveyed in the heating chamber by the conveying portion and blows high-temperature air, and a blowing portion that is provided above the heating chamber and is surrounded by the blowing portion. A circulation blower that circulates the air inside and outside the heating space by sucking up the air in the heating space to the outside of the heating space and sending the sucked air into the heating space, and heating the air circulated by the circulation blower. and a heating member, wherein the inside air returning unit may return the air, which has been moved from the heating chamber to the outside of the heating chamber, from the upper portion of the heating chamber to the outside of the heating space.

According to the above configuration, the air in the heating chamber is sucked up from the heating space surrounding the article to the outside of the heating space by the circulation blower, and is circulated through the circulation path sent into the heating space from the outside of the heating space. Further, the circulated air in the heating chamber is heated by the heating member on the circulation path. Air moved from the heating chamber to the outside of the heating chamber by the internal air return unit is returned from the upper part of the heating chamber to the outside of the heating space, and moves from the heating chamber to the outside of the heating chamber on the circulation path of the air in the heating chamber by the circulation blower. It can return the air that has been let in. Thereby, the circulation efficiency of the air in the heating chamber can be improved.

According to one aspect of the present invention, it is possible to provide a heat-shrinking apparatus for a heat-shrinkable film that can save energy.

1 is a partial cross-sectional view showing the configuration of a heat shrinking device according to an embodiment of the present invention; FIG. FIG. 4 is a vertical cross-sectional view showing the internal structure of a heating chamber of the heat shrinking device; FIG. 3 is a schematic diagram showing a schematic configuration of a circulation section in the heat shrinking device; FIG. 4 is a path diagram of the suction side of the circulation section of the heat shrinking device. FIG. 2 is a path diagram of the discharge side of the circulation unit of the heat shrinking device. It is a schematic diagram which shows schematic structure of the conventional heat-shrinking apparatus.

[Embodiment]
An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 6. FIG. In the following description, the conveyer 3 side of the heat shrinking device 1 is referred to as the lower part, and the circulation blower 12 side is referred to as the upper part.

[Overview of Heat Shrink Device]
FIG. 1 is a partial cross-sectional view showing the configuration of a heat shrinking device 1 according to an embodiment of the present invention, and the section of the heat shrinking device 1 below the broken line D in FIG. The heat-shrinking apparatus 1 is a device that applies steam or hot air to a container 10 (article) coated with a heat-shrinkable label 101 (film) to heat-shrink the label 101 and adhere the label 101 to the container 10 . be. As shown in FIG. 1, the heat shrinking apparatus 1 includes a heating chamber 2, a conveyor 3 (conveying section), and a circulation section 40 (see FIG. 3).

The conveyor 3 conveys the container 10 covered with the heat-shrinkable label 101 in a predetermined direction. The conveyor 3 is, for example, a belt conveyor, and has a conveyor belt 31 , a drive shaft 32 , a conveyor motor 33 (see FIG. 3), and a driven shaft 34 . The conveyor belt 31 is formed in a ring shape, and on the inner surface of the conveyor belt 31, a drive shaft 32 and a driven shaft 34 arranged substantially parallel are arranged at both ends. In other words, the conveyor belt 31 is wound around the drive shaft 32 and the driven shaft 34 . Thereby, a space 35 is formed on the inner surface side of the conveyor belt 31 . A conveyor motor 33 is connected to the drive shaft 32 . Rotation of the conveyor motor 33 is transmitted to the drive shaft 32 , and the conveyor belt 31 moves along with the rotation of the conveyor motor 33 . The driven shaft 34 rotates as the conveyor belt 31 rotates.

The conveyor belt 31 has a mounting surface 31a on which the container 10 is mounted. A plurality of openings 31b are formed at predetermined intervals on the mounting surface 31a. The opening 31b is formed so as to penetrate between the mounting surface 31a of the conveyor belt 31 and the inner surface. The conveyor 3 moves the heating chamber 2 while the container 10 is placed on the placement surface 31a so as to close the opening 31b. In the space 35 on the inner surface side of the conveyor belt 31, the suction ducts 42 of the circulation section 40 (see FIG. 3) are arranged at the same intervals as the openings 31b.

The circulation unit 40 (see FIG. 3) sucks the air in the heating chamber 2 from below the opening 31b to the outside of the heating chamber 2, and also removes the sucked air (the air moved from the heating chamber 2) from the heating chamber 2. Air is circulated back into the heating chamber 2 . The suction duct 42 is provided as a pipe for sucking air from the heating chamber 2, as shown in FIG. The suction duct 42 extends from the bottom to the top of the space 35 to the vicinity of the inner surface of the conveyor belt 31 located at the top, and the upper end 42a that is one end of the suction duct 42 is the inner surface of the conveyor belt 31 located at the top. opened nearby. The other end of the suction duct 42 is connected to the suction blower 41 (see FIG. 3).

In the heating chamber 2 , hot air or steam is applied to the label 101 when the label 101 is adhered to the container 10 . At that time, if the container 10 is not fixed to the conveyor belt 31, the container 10 will move from its fixed position due to the wind velocity of the hot air or the pressure of the steam, and the hot air or steam will not hit a desired portion of the container 10. - 特許庁Therefore, in the heat-shrinking device 1 , the container 10 is fixed to the conveyor 3 using the circulation unit 40 . Specifically, the moving conveyor belt 31 stops when the position of the opening 31b substantially coincides with the position of the opening of the upper end 42a of the suction duct 42 . Then, when heating starts in the heating chamber 2, the suction blower 41 sucks the air in the heating chamber 2 through the suction duct 42 from below the opening 31b. As a result, the space below the bottom surface of the container 10 is put into a negative pressure state, and the container 10 placed on the opening 31b is fixed to the conveyor 3 . Details of the circulation unit 40 will be described later.

The container 10 is, for example, a polyester PET bottle formed by blow molding. However, the object covered with the label 101 is not limited to the container 10, and may be any article that is used with the label 101 wrapped around it.

The label 101 is formed of a heat-shrinkable film (shrink film) made of polyethylene, polypropylene, PVC, or the like. The label 101 is formed in a cylindrical shape by joining both ends thereof, then wound into a roll, and cut into a predetermined length while unrolling the roll. The label 101 is opened in a cylindrical shape by an opening device (not shown) and attached so as to cover the container 10 .

The heating chamber 2 forms a space for heating the label 101 covering the container 10 conveyed by the conveyor 3 . The heating chamber 2 heats and shrinks the label 101 covering the container 10 to bring it into close contact with the container 10 . The temperature for heat shrinking the label 101 is, for example, 160° C. or higher and 220° C. or lower.

[Details of heating chamber]
Next, the internal structure of the heating chamber 2 will be described with reference to FIGS. 1 and 2. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, which is a vertical cross-sectional view showing the internal structure of the heating chamber 2 of the heat shrinking device 1. FIG. As shown in FIG. 2 , the heating chamber 2 has an outer shell 11 , a circulation blower 12 , a heater 13 (heating member), and an air guide section 14 .

The shell 11 forms the shell of the heating chamber 2 . The outer shell 11 has a top wall 11a and side walls 11b extending downward from both side ends of the top wall 11a, and has an open bottom end. The heating chamber 2 is covered by the conveyor 3 , and the outer shell 11 has an inlet 21 for the containers 10 conveyed by the conveyor 3 to enter the heating chamber 2 , and an inlet 21 for conveying the containers 10 conveyed in the heating chamber 2 by the conveyor 3 . An outlet 22 is formed for the heated container 10 to exit the heating chamber 2 .

The circulation blower 12 is provided in the upper part of the heating chamber 2 and circulates the air heated by the heater 13 in the heating chamber 2 by sucking up the air in the heating chamber 2 and blowing it out sideways. In other words, the circulation blower 12 sucks up the air in the heating zone 19 surrounded by the nozzle wall 17 described later to the outside of the heating zone 19, blows the sucked air out of the heating zone 19, and feeds it into the heating zone 19. , to circulate the air inside and outside the heating zone 19 . The circulation blower 12 has a blower motor 12a, blades 12b, and a casing 12c. The blower motor 12a is mounted on the upper wall 11a of the shell 11. As shown in FIG. The blades 12b rotate via the drive shaft of the blower motor 12a. The blades 12b are provided inside a casing 12c arranged near the inner surface of the upper wall 11a of the outer shell 11 . The air sucked from below the casing 12c by the rotation of the blades 12b is blown out in the diametrical direction of the blades 12b from the outlet of the casing 12c provided on the side of the blades 12b.

The heater 13 is a heating element such as a sheathed heater and has a circular shape. The heater 13 is attached to the inner surface of the upper wall 11a of the shell 11 so as to be arranged around the casing 12c. The heater 13 heats the air blown out from the outlet of the casing 12c. In other words, the heater 13 is attached to the side of the circulation blower 12 and heats the air that circulates in the heating chamber 2 and is blown sideways by the circulation blower 12 .

The air guide section 14 has a fixed wall 16 and two nozzle walls 17 (first spray section).

The fixed wall 16 has an upper surface portion and side surface portions extending downward from both side ends of the upper surface portion, and has an open lower end. The upper surface portion is connected to the casing 12c and has a through hole that allows the casing 12c and the air guide portion 14 to communicate with each other. The position of the lower end of the side portion is the same as the position of the lower end of the side wall 11 b of the outer shell 11 . The fixed wall 16 is formed smaller than the outer shell 11, and is arranged at a position such that the outer surface of the side portion of the fixed wall 16 is spaced from the inner surface of the side wall 11b of the outer shell 11 by a predetermined distance. Thereby, a circulation space 18 is formed between the inner surface of the side wall 11 b of the outer shell 11 and the outer surface of the side surface of the fixed wall 16 .

The nozzle wall 17 is fitted to two side surfaces of the fixed wall 16 so as to face each other. The nozzle wall 17 has many nozzle holes 17a. The nozzle holes 17a are arranged in a matrix and formed to penetrate the nozzle wall 17 in the horizontal direction. The nozzle wall 17 blows hot air to the container 10 through nozzle holes 17a. The container 10 passes through a heating zone 19 (heating space), which is the space formed between opposing nozzle walls 17 . In other words, the nozzle wall 17 surrounds the container 10 conveyed in the heating chamber 2 by the conveyor 3 and blows hot air onto the container 10 . The shape of the nozzle hole 17a is not limited to the shape shown in FIG. 2, and can be set as appropriate.

[Air circulation in the heating chamber]
In the heating chamber 2 configured as described above, the air in the heating zone 19 inside the fixed wall 16 is sucked up by the circulation blower 12, blown to the side of the heater 13 by the blades 12b, and heated by the heater 13. . The heated air passes through the circulation space 18 and is blown out from each nozzle hole 17a of the nozzle wall 17 to the heating zone 19, heats the label 101 coated on the container 10, and is sucked up by the circulation blower 12 again.

Thus, the circulation blower 12 generates an air flow that circulates the air heated by the heater 13 inside the heating chamber 2 . Thereby, the heated air circulates in the heating chamber 2 .

The heat-shrinking device 1 has a control section (not shown). The controller controls the heat generation temperature of the heater 13 so that the temperature of the air detected by a temperature sensor (not shown) arranged in the circulation space 18 reaches a predetermined temperature.

The nozzle wall 17 may be provided so that the nozzle hole 17a can be opened and closed. As a result, the hot air can be blown out to desired locations of the container 10 .

[Circulation part]
The circulation unit 40 will be described with reference to FIGS. 1 to 5. FIG. FIG. 3 is a schematic diagram showing a schematic configuration of the circulation section 40 in the heat shrinking device 1. As shown in FIG. A two-dot chain line in FIG. 3 is a virtual line and indicates the heating chamber 2 . FIG. 4 is a partial cross-sectional view taken along line BB in FIG. 3, and is a path diagram of the suction side of the circulation unit 40 of the heat shrinking device 1. As shown in FIG. FIG. 5 is another part of the cross-sectional view taken along line BB in FIG. 5 is a side view of the heating chamber 2 viewed from the conveyor motor 33 side.

As shown in FIGS. 1 and 3 to 5, the circulation unit 40 sucks the air in the heating chamber 2 out of the heating chamber 2 through the opening 31b. Also, the circulation unit 40 blows suction air through the return air supply unit 50 to the container 10 in which the label 101 is heated and shrunk. A detailed description is given below.

As shown in FIG. 3, the circulation unit 40 includes a suction blower 41 (inside air moving unit, inside air returning unit), a suction duct 42 (inside air moving unit), a return air duct 43 (inside air returning unit), and a return air supply unit. and a section 50 (shy air return section). The suction blower 41 sucks air from the suction port and discharges the sucked air from the discharge port.

(Suction side of circulation unit (internal air moving unit))
The suction side of the circulation part 40 moves the air in the heating chamber 2 out of the heating chamber 2 through the opening 31b provided in the mounting surface 31a. As shown in FIGS. 1, 3 and 4, the circulation section 40 has a suction duct 42 on the suction side of the suction blower 41 . One end of the suction duct 42 is connected to the suction port of the suction blower 41, and the other end of the suction duct 42 extends from the bottom to the top of the space 35 in the space 35 inside the conveyor 3, and the conveyor belt located at the top. It is open near the inner surface of 31 . The suction ducts 42 are raised at the same intervals as the openings 31b are arranged, and the suction ducts 42 branched so as to be raised in the space 35 are merged and connected to the suction blower 41. there is

When heating starts in the heating chamber 2, the suction blower 41 starts sucking, and the suction blower 41 sucks the heated air in the heating chamber 2 from below the opening 31b. As a result, the heated air in the heating chamber 2 is sucked to the outside of the heating chamber 2 as indicated by the arrows in FIGS. 3 and 4 . The suction force by the suction blower 41 can be manually set and can be changed according to the container 10 . After setting the suction force, the suction blower 41 is driven with a constant suction force, and the suction force is not changed while the heat shrinking apparatus 1 is in operation. In this embodiment, the suction blower 41 sucks the air in the heating chamber 2 and moves it out of the heating chamber 2, but the method of moving the air in the heating chamber 2 out of the heating chamber 2 is not limited to the above. Any method may be used as long as the air in the heating chamber 2 can be moved to the outside of the heating chamber 2 .

(Discharge side of circulation unit (internal air return unit))
The discharge side of the circulation unit 40 returns the air moved from the inside of the heating chamber 2 to the outside of the heating chamber 2 into the heating chamber 2 . As shown in FIGS. 1 , 3 and 5 , the circulation section 40 has a return air duct 43 and a return air supply section 50 on the discharge side of the suction blower 41 . The return air duct 43 has one end connected to the discharge port of the suction duct 42 and the other end connected to the return air supply section 50 .

The return air supply unit 50 is a substantially rectangular parallelepiped box. A pair of return air supply units 50 are provided on both sides near the exit of the heating chamber 2 , and the conveyor belt 31 passes between the return air supply units 50 . That is, the container 10 with the label 101 adhered thereto by heat shrinkage passes between the return air supply units 50 arranged on both sides of the heat shrinkage device 1 . The return air supply unit 50 has a return air nozzle wall 51 (second blowing unit) that blows suction air onto the container 10 in which the label 101 is heated and shrunk in the heating chamber 2 . Specifically, a return air nozzle wall 51 is formed on the side surface of the return air supply unit 50 on the side through which the conveyor belt 31 passes. The return air nozzle wall 51 has a large number of return air nozzle holes 50a. The return air nozzle holes 50a are arranged in a matrix and are formed so as to penetrate the return air nozzle wall 51 of the return air supply section 50 in the horizontal direction. The shape of the return air nozzle hole 50a is not limited to the shape shown in FIG. 5, and can be set as appropriate.

The suctioned air sucked by the suction blower 41 passes through the return air duct 43 as indicated by the arrow in FIG. is sprayed onto the container 10. By further blowing suction air onto the container 10, the label 101 can be pre-shrunk, and the finish of the heat shrinkage of the label 101 can be assisted. The air blown onto the container 10 is circulated again in the heating chamber 2 by the air circulation in the heating chamber 2 described above.

Here, since the suction blower 41 is located outside the heating chamber 2, the air sucked from the heating chamber 2 comes out of the heating chamber 2 once. do not have. Therefore, the time required for temperature rise of the circulating air in the heating chamber 2 is shorter than when fresh air is taken into the heating chamber 2 from the outside and circulated, and the thermal efficiency of the heat shrinking device 1 is improved.

It is desirable that the velocity of the air blown onto the container 10 from the return air nozzle hole 50a is faster. This can prevent the heat of the heating chamber 2 from leaking to the outside through the outlet of the heating chamber 2 . Even if the wind speed is slow, it does not affect the shrinkage of the label 101 .

[effect]
FIG. 6 is a schematic diagram showing a schematic configuration of a heat shrinking device 100, which is an example of a conventional heat shrinking device. A two-dot chain line in FIG. 6 is a virtual line and indicates the heating chamber 2 . As shown in FIG. 6, in the conventional heat shrinking device 100, the heated air in the heating chamber 2 sucked from the opening 31b of the conveyor belt 31 is exhausted into the room in which the heat shrinking device 100 is installed. was Therefore, the indoor environment of the room where the heat shrinking device 100 is installed is affected, such as the temperature and humidity of the room where the heat shrinking device 100 is installed and the air pressure in the room fluctuates. In order to solve such a problem, it is sufficient to discharge the sucked air to the outside of the building like the technique disclosed in the above-mentioned Patent Document 1, but there is another problem that requires an exhaust structure to the outside of the building. be.

Further, in the heat shrinking apparatus 100 and the heat shrinking apparatus adopting the technology of Patent Document 1, the heat in the heating chamber 2 is also discharged to the outside of the heating chamber 2 together with the air in the heating chamber 2 . As a result, the temperature in the heating chamber 2 decreases, and the temperature required for finishing the heat shrinkage to bring the label 101 into close contact with the container 10 cannot be ensured. In such a state, the temperature detected by the temperature sensor provided in the circulation space 18 decreases, so the control unit adjusts the temperature in the heating chamber 2 necessary for finishing the adhesion of the label 101 to the container 10 by heat shrinkage. In order to ensure this, the heat generation temperature of the heater 13 had to be increased. For example, it is necessary to increase the heating temperature (finished temperature) of the heater 13 to about 250.degree.

On the other hand, in the present embodiment, the heat of the heating chamber 2 sucked together with the air in the heating chamber 2 is returned to the heating chamber 2 by the circulation unit 40. Therefore, in the conventional case of introducing new air into the heating chamber 2 from the outside, energy saving can be achieved. Specifically, in the conventional case, the finish temperature required for the label 101 to adhere to the container 10 was about 150°C, whereas according to the present invention, the finish temperature is lowered to about 125°C. be able to. That is, about 17% of energy saving can be realized about finishing temperature. In addition, in the conventional case, the wind speed of the air blown onto the container 10 through the nozzle hole 17a was about 55 m/s, but according to the present invention, the wind speed can be reduced to about 45 m/s. . That is, about 18% of energy saving can be realized about wind speed. Furthermore, since the heat of the heating chamber 2 that is sucked can be reused, waste heat can be reduced.

In addition, since the sucked air in the heating chamber 2 is blown out near the outlet 22 of the heating chamber 2, the heat of the heating chamber 2 can be prevented from leaking to the outside from the outlet 22 of the heating chamber 2. - 特許庁

Also, with such a configuration, it is possible to reduce exhaust heat and lower the finish temperature required for the film to adhere to the article due to heat shrinkage. This will contribute to achieving Goal 7 of the Sustainable Development Goals (SDGs), "Affordable and clean energy".

[Modification]
Modifications of the present invention will be described below. For convenience of description, members having the same functions as those of the members described in the above embodiments are denoted by the same reference numerals, and description thereof will not be repeated.

In the above embodiment, the heated air in the heating chamber 2 sucked by the suction blower 41 is blown against the container 10 by the return air supply unit 50, but the present invention is not limited to the above. The circulation unit 40 may return the heated air in the heating chamber 2 sucked by the suction blower 41 to, for example, above at least one of the inlet 21 and the outlet 22 in the heating chamber 2 shown in FIG. This can prevent the heat of the heating chamber 2 from leaking to the outside through at least one of the inlet 21 and the outlet 22 of the heating chamber 2 .

Furthermore, the circulation unit 40 may return the heated air in the heating chamber 2 sucked by the suction blower 41 into the heating chamber 2 from the upper part of the heating chamber 2 . Specifically, as shown in FIG. 2 , a blower outlet 60 may be arranged above the heating zone 19 , and the circulation unit 40 may blow the suction air from the blower outlet 60 toward the lower part of the heating zone 19 . As a tendency, heat tends to accumulate in the upper portion of the heating zone 19, and the heat in the lower portion of the heating zone 19 decreases. Therefore, the heat accumulated in the upper part of the heating zone 19 can be sent to the lower part of the heating zone 19 by blowing out the sucked air toward the lower part of the heating zone 19 from the outlet 60 arranged in the upper part of the heating zone 19. can. As a result, the heat in the heating zone 19 can be made uniform, and the finish of the label 101 can be made uniform.

Also, the heated air in the heating chamber 2 sucked by the suction blower 41 may be returned from the upper portion of the heating chamber 2 to the inside of the heating chamber 2 and outside the heating zone 19 . Specifically, as shown in FIG. 2, a blowout port 70 may be formed in the upper surface wall 11a of the outer shell 11, and the circulation unit 40 may blow the sucked air from the blowout port 70 toward the lower part of the heating chamber 2. . In this way, by returning the sucked air to the circulation path of the air in the heating chamber 2 by the circulation blower 12, the efficiency of circulating the air in the heating chamber 2 can be improved. Further, although not shown, an outlet may be formed in the upper portion of the side wall 11b of the outer shell 11. FIG. The outlet is formed so as to slope downward from the outer surface to the inner surface of the side wall 11b. The circulation unit 40 may blow the suction air obliquely downward into the heating chamber 2 from such a blowout port.

Also, the circulation unit 40 may supply suction air to a space other than the heating chamber 2 where the label 101 is heated, such as a preheating chamber, in the same manner as the heating chamber 2 . The preheating chamber heats the label 101 at a temperature lower than the temperature of the heating chamber 2 so as to shrink the label 101 to some extent before heating by the heating chamber 2 . The air in the heating chamber 2 sucked by the circulation part 40 is supplied to the preheating chamber through a duct connected between the heating chamber 2 and the preheating chamber. When the temperature of the suctioned air supplied to the preheating chamber drops due to the influence of the outside air temperature while passing through the duct, the heater in the preheating chamber heats the suctioned air to an appropriate temperature. By supplying the air sucked from the heating chamber 2 to the preheating chamber in this way, the thermal efficiency in the preheating chamber can be improved.

Also, the suctioned air may be returned to the circulation space 18 by the circulation unit 40 . Specifically, for example, as shown in FIG. 5, the wall surface of the return air supply unit 50 on the nozzle wall 17 side is provided with a hole 50b from the top to the bottom, and the suction air is returned to the circulation space 18 side through the hole 50b. good. As a result, the opening area of the return air supply unit 50 is increased, and the suction force of the air inside the heating chamber 2 of the circulation unit 40 can be increased. In addition, the effect of preventing hot air from exiting from the outlet 22 of the heating chamber 2 by the holes 50a can be further enhanced. Furthermore, as shown in FIG. 5 , the upper surface of the return air supply unit 50 may be provided with holes 50c through which the suctioned air is returned to the circulation space 18 . As a result, the sucked air can be returned to a location near the circulation blower 12 .

[Additional notes]
The present invention is not limited to the above-described embodiments, and can be modified in various ways within the scope of the claims. included in the technical scope of

1 Heat Shrink Device 2 Heating Chamber 3 Conveyor (Conveyor)
10 container (goods)
12 circulation blower 13 heater (heating member)
17 Nozzle wall (first spraying part, spraying part)
19 heating zone (heating space)
21 inlet 22 outlet 31a placement surface 31b opening 41 suction blower (internal air moving unit, internal air returning unit)
42 Suction duct (inside air moving part)
43 return air duct (inside air return part)
50 return air supply unit (inside air return unit)
51 return air nozzle wall (second blowing part)
101 label (film)

Claims (5)

a heating chamber for heat-shrinking the heat-shrinkable film covering the article;
a transport unit having a placement surface for placing the article, and for transporting the article in the heating chamber;
an inside air moving part for moving the air in the heating chamber to the outside of the heating chamber through an opening provided in the mounting surface;
and an internal air returning unit for returning air moved from the heating chamber to the outside of the heating chamber into the heating chamber. a first blowing section for blowing hot air onto the article;
2. The apparatus according to claim 1, further comprising a second blowing section for blowing air moved from the heating chamber to the outside of the heating chamber onto the article whose film has been heat-shrunk by the first blowing section. A heat shrink device as described. The heating chamber has an entrance through which the article conveyed by the conveying unit enters the heating chamber, and an exit through which the article conveyed in the heating chamber by the conveying unit exits the heating chamber. have
3. The heat shrinking apparatus according to claim 1, wherein the inside air returning unit returns the air moved from the heating chamber to the outside of the heating chamber to an upper portion of at least one of the inlet and the outlet. 4. The heat shrinking apparatus according to any one of claims 1 to 3, wherein the inside air returning unit returns the air moved from the heating chamber to the outside of the heating chamber to an upper portion of the heating chamber. The heating chamber surrounds the article conveyed in the heating chamber by the conveying unit, and a blowing unit for blowing high-temperature air;
The air in the heating space, which is provided in the upper part of the heating chamber and surrounded by the blowing part, is sucked up to the outside of the heating space, and the sucked air is sent into the heating space, thereby circulating the air inside and outside the heating space. a circulation blower;
a heating member that heats the air circulated by the circulation blower;
5. The inside air return unit according to any one of claims 1 to 4, wherein the air that has been moved from the heating chamber to the outside of the heating chamber is returned from an upper portion of the heating chamber to the outside of the heating space. Heat shrink device.

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