JP7622951B1 - Heat shrink equipment - Google Patents

Abstract

A heat shrink device capable of satisfactorily shrinking a packaging material is provided.
[Solution] A heat shrink device comprising a main body 1 capable of ejecting hot air between an entrance 1a and an exit 1b, and a pair of conveying members 5, 6 that convey a packaged item, in which an item to be packaged X is wrapped in packaging material Y, in a conveying direction from the entrance 1a to the exit 1b, and across which the packaged item is placed, configured to eject hot air toward the packaged item being conveyed in the conveying direction from the entrance 1a to the exit 1b, thereby shrinking the packaging material Y of the packaged item toward the item to be packaged X, and the pair of conveying members 5, 6 have a wide portion 30 with a wider gap therebetween and a narrow portion 31 with a narrower gap than the wide portion 30.
[Selected figure] Figure 3

Description

The present invention relates to a heat shrinking device for heat shrinkable packaging materials that transports packaged items wrapped in a heat shrinkable packaging material (e.g., shrink film) as a package and heat shrinks the packaging material during the transport process.

Patent Document 1 describes a film heat shrink device. This film heat shrink device is equipped with a freely running lower endless belt of a lower transport conveyor that transports packaged items in a received state in the device main body, and the article placement surface of the lower endless belt is formed in a mesh shape so that when a packaged item wrapped in heat shrink film (packaging material) is placed and transported, the film on the bottom side of the packaged item is also heated. In addition, an upper endless belt is wrapped around the device main body to form an upper belt conveyor, and the packaged item is transported while being sandwiched between the upper and lower endless belts.

The device body is provided with a heating tunnel for heating the packaged goods wrapped in heat-shrinkable film and shrinking the film over the required range of the goods conveying section from the upstream side to the downstream side of the lower endless belt. Inside this heating tunnel, air heated by a heater is blown out from multiple outlets, and the heated air is forcibly circulated by a fan, heating the sides and bottom of the packaged goods.

In the film heat shrink device, the transported packaged item is conveyed toward the entrance of the heating tunnel and is pressed by the item clamping surface of the upper endless belt facing the upstream inclined portion of the upper belt conveyor, and upstream of the entrance of the heating tunnel the packaged item is clamped between the upper and lower conveyors. In this state, the packaged item transported inside the heating tunnel has its top surface covered by the upper belt conveyor, so only its sides and bottom are heated by heated air, and the heat shrink film in the corresponding areas shrinks and adheres to the packaged item.

Japanese Patent Application Publication No. 11-001211

In the film heat shrinking device of Patent Document 1, the packaged item is conveyed while being sandwiched from above and below between an upper endless belt and a lower endless belt.

However, when the packaged goods are being transported, only the sides and bottom are heated by the heated air, and the heat shrink film in the corresponding areas shrinks and adheres closely to the packaged goods, making it difficult for the heated air to reach other areas. In other words, the same parts of the packaged goods are in contact with the upper and lower endless belts. For this reason, even if the heat shrink film shrinks toward the packaged goods, the heat shrink film is prone to shrinkage defects.

Therefore, the present invention aims to provide a heat shrink device that can effectively shrink packaging materials.

The present invention is a heat shrinking device that includes a heating device main body having an entrance and an exit and capable of discharging hot air between the entrance and the exit, and a conveying section that conveys a packaged item in which an object to be packaged is wrapped in a packaging material in a conveying direction from the entrance to the exit, and that causes the packaging material of the packaged item to shrink toward the object to be packaged by discharging hot air toward the packaged item being conveyed in the conveying direction from the entrance to the exit by the conveying section, and the conveying section includes a pair of conveying members that are spaced apart in the width direction, and the packaged item to be conveyed is placed across the pair of conveying members, and the pair of conveying members includes a wide portion where the gap is wider and a narrow portion where the gap is narrower than the wide portion.

In the heat shrink device configured as described above, the package is placed between the entrance and exit of the heating device body, straddling the pair of conveying members of the conveying section. When the package is conveyed in this state in the conveying direction, the contact position of the packaging member enclosing the package changes between the wide and narrow parts of the pair of conveying members of the conveying section, so that the hot air hits the entire packaging material.

In the present invention, the pair of conveying members may be configured to include at least one of an expanding width portion that gradually widens from the narrow width portion to the wide width portion from the entrance side to the exit side, and a reducing width portion that gradually narrows from the wide width portion to the narrow width portion from the entrance side to the exit side.

In the heat shrinking device of the above configuration, the pair of conveying members has at least one of a width expanding section and a width reducing section, so that the contact position of the packaging material with the pair of conveying members gradually changes while being conveyed by the pair of conveying members, and hot air can be applied to the entire packaging material while suppressing sudden changes in the position of the package during transport.

In the present invention, the pair of conveying members has a conveying surface on which the package is placed, and the package is configured by wrapping the cylindrical packaged object conveyed with its central axis aligned along the conveying direction in the sheet-like packaging member, and it is also possible to configure both the width-enlarging portion and the width-reducing portion to come into contact with the package within an opposing region that faces the conveying surface on the outer peripheral surface around the central axis of the package.

In a heat shrink device with the above configuration, the width expanding section and the width reducing section come into contact within the area of the packaging material that faces the conveying surface on the outer peripheral surface around the central axis of the packaged item, so the packaged item is firmly supported and conveyed while hot air is applied to the entire packaged item.

The present invention can also be configured to include a gap difference adjustment means that can adjust the gap difference between the gap between the wide portion and the narrow portion.

The heat shrinking device configured as described above is equipped with a gap difference adjustment means that can adjust the gap difference between the wide and narrow sections, making it possible to adjust the gap difference between the pair of conveying members and to apply hot air to the entire package while firmly supporting and conveying the package in accordance with the shape of the packaging member.

The heat shrinking device of the present invention prevents poor shrinkage of the packaging material because the contact position of the packaging material encasing the packaged item changes between the wide and narrow parts of the package and hot air hits the entire package.

1 is a schematic side view illustrating an overall configuration of a conveying device according to an embodiment of the present invention. FIG. FIG. FIG. 13 is a diagram showing how packages are supported at the entrance of the main body. FIG. 2 is a perspective view of a package at an entrance of the main body. FIG. 13 is a diagram showing how packages are supported at the outlet of the main body. FIG. 2 is a perspective view of a package at the outlet of the main body. FIG. 2 is an enlarged view showing a region of the film.

The heat shrink device according to one embodiment of the present invention will be described below with reference to Figures 1 to 8.

The heat shrinking device of this embodiment is disposed downstream of the packaging device. The packaging device includes a bag maker that wraps the packaged object (hereinafter referred to as object X as shown in Figs. 1 and 2) in a packaging material (hereinafter referred to as film Y as shown in Figs. 1 and 2), a vertical seal section that seals the joints of film Y together while object X is wrapped in film Y, and a horizontal seal section (end seal section) that is disposed between the vertical seal section and the heat shrinking device and welds film Y in the front-to-back direction of object X packaged in the vertical seal section and cuts the object X. The pillow-packaged package, i.e., the package cut by welding film Y in the front-to-back direction of object X by the horizontal seal section, is conveyed to the heat shrinking device.

In the following description, film Y and item X wrapped in film Y are defined as a package. In the following description, the direction horizontally perpendicular to the conveying direction is defined as the width direction of the heat shrink device.

Next, the configuration of the heat shrinking device will be described. As shown in FIG. 1, the heat shrinking device includes a main body 1 as the heat shrinking device main body, which is provided with an inlet 1a and an outlet 1b for the packaged object X to be packaged with a heat shrinkable film Y, a conveying section 2 that conveys the packaged object from the inlet 1a to the outlet 1b within the main body 1, heating means 3 (shown in FIG. 1 and FIG. 2, but including a heater and a fan not shown) that heat shrinks the film Y in the packaged object conveyed by the conveying section 2, and a driving means 4 that serves as the driving source for the conveying section 2.

The main body 1 has a tunnel-shaped transport space 1A for packaged items so that the heat generated by the heater of the heating means 3 is retained inside using a fan.

The conveying section 2 includes a first conveying member 5 and a second conveying member 6, as shown in Figs. 4 and 6. The first conveying member 5 and the second conveying member 6 are arranged in parallel with a predetermined distance d1, d2 between them in a direction perpendicular or substantially perpendicular to the conveying direction of the packages, i.e., in the width direction as shown in Figs. 2 and 3, and rotate endlessly at the same speed or substantially the same speed along the conveying direction of the packages. Such first conveying member 5 and second conveying member 6 correspond to a pair of conveying members in the width direction.

As shown in Figs. 3, 4, and 6, the package is placed across the first conveying member 5 and the second conveying member 6 and conveyed. In other words, the first conveying member 5 and the second conveying member 6 have a double belt conveying portion, and the first conveying member 5 and the second conveying member 6 arranged side by side and spaced apart form a long conveying path for the package. In Figs. 1 and 3, the uppermost end surface of the first conveying member 5 is represented as the conveying surface 5b, and the uppermost end surface of the second conveying member 6 is represented as the conveying surface 6b.

As shown in FIG. 1, the conveying unit 2 further includes a first support portion 7 and a second support portion 8. The first support portion 7 is configured to support the inner peripheral surface side of the first conveying member 5 so that the first conveying member 5 and the second conveying member 6 rotate endlessly along the conveying direction of the package. The second support portion 8 is configured to support the inner peripheral surface side of the second conveying member 6.

The first support section 7 includes guide sections 9a, 9b, a first direction change member 10, and a second direction change member 11 shown in FIG. 1. As shown in FIG. 4, the guide sections 9a, 9b are arranged along the package transport path and are held at a constant interval in the width direction, and are configured to guide the first transport member 5 along the transport path. The guide sections 9a, 9b are arranged in pairs on one side in the width direction, and the first transport member 5 is wound around them. A horizontal support member 26 is provided between the guide sections 9a, 9b to keep the first transport member 5 horizontal.

The guides 9a and 9b are connected to the top of the base 27. The base 27 is formed in a plate shape, and both ends in the width direction are fixed to the main body 1. As described below, the base 27 is formed as a common base 27 with the guides 18a and 18b arranged as a pair on the other side of the second conveying member 6 in the width direction, and therefore the guides 9a and 9b and the guides 18a and 18b are connected to the top of the base 27. The base 27 is located below the guides 9a and 9b (guide parts 18a and 18b), is arranged in a horizontal state, and is formed larger than the width dimension of the package. The guides 9a and 9b and the guides 18a and 18b are provided on the base 27 formed in this way across the carry-in entrance 1a and the carry-out exit 1b of the main body 1.

The first direction-changing member 10 (here, a driving pulley) is rotatable around a driving shaft 28, is arranged at the upstream end of the package conveying path, and is configured to receive a driving force from the driving means 4. The second direction-changing member 11 (here, a driven pulley) is rotatable around a driven shaft 29, and is arranged at the downstream end of the package conveying path. The first direction-changing member 10 and the second direction-changing member 11 are configured to be rotatable around an axis that is parallel to the package conveying path and perpendicular to the conveying direction.

As shown in FIG. 4, the first support portion 7 further includes a regulating portion 12 that regulates the displacement of the first conveying member 5 in a direction substantially perpendicular to the conveying direction of the package. The regulating portion 12 includes protrusions 13, 13 and grooves 14, 14. The protrusions 13, 13 are provided on the inner peripheral surface side of the first conveying member 5, and two are formed in the width direction. The grooves 14, 14 are provided between the guide portions 9a, 9b of the first support portion 7 and the horizontal support member 26, and two are formed so that the protrusions 13, 13 of the first conveying member 5 can be inserted therein.

The first conveying member 5 has a plurality of openings formed in the widthwise center 5a so that hot air from the heating means 3 can pass through. Specifically, the widthwise center 5a of the first conveying member 5 is formed in a mesh shape so that hot air from the heating means 3 blown out from the widthwise center of the guide parts 9a, 9b of the long first support part 7 extending in the conveying direction can pass through. More specifically, the first conveying member 5 is formed by processing the mesh belt so that both ends in the width direction are reinforced.

The first conveying member 5 rotates by receiving the driving force of the driving means 4 from the first direction changing member 10 of the first support section 7. Specifically, the first conveying member 5 is pressed against a transmission member (not shown) provided on the first direction changing member 10 of the first support section 7. The transmission member is also made of a material (here, rubber) that has a frictional force that prevents the contact area with the first conveying member 5 from being displaced.

The second conveying member 6 has a basic configuration similar to that of the first conveying member 5, and the second support portion 8 has a basic configuration similar to that of the first support portion 7.

The second support section 8 includes guide sections 18a and 18b shown in FIG. 4, a first direction change member 19 shown in FIG. 1, and a second direction change member 20. As shown in FIG. 4, the guide sections 18a and 18b are arranged along the transport path for the packages and are held at a constant interval in the width direction, and are configured to guide the second transport member 6 along the transport path. The second transport member 6 is wound around the guide sections 18a and 18b. A horizontal support member 26 is provided between the guide sections 18a and 18b to keep the second transport member 6 horizontal.

The second support portion 8 further includes a regulating portion 21 that regulates the displacement of the second conveying member 6 in a direction perpendicular or substantially perpendicular to the conveying direction of the package. The regulating portion 21 includes protrusions 22, 22 and grooves 23, 23. The protrusions 22, 22 are provided on the inner peripheral surface side of the second conveying member 6, and two are formed in the width direction. The grooves 23, 23 are provided on the guide portions 18a, 18b of the second support portion 8 and the horizontal support member 26, and two are formed so that the protrusions 22, 22 of the second conveying member 6 can be inserted into them.

The second conveying member 6 has a plurality of openings formed in its widthwise central portion 6a so that hot air from the heating means 3 can pass through. The second conveying member 6 rotates by receiving the driving force of the driving means 4 from the first direction-changing member 19 of the second support portion 8. Specifically, the second conveying member 6 is pressed against a transmission member (not shown) provided on the first direction-changing member 19 of the second support portion 8, and the force is transmitted to the second conveying member 6.

The first direction changing members 10, 19 of the first support section 7 and the second support section 8 are horizontally arranged members, but as described below, the first conveying member 5 and the second conveying member 6 are different members because they extend from the inlet 1a to the outlet 1b of the main body 1. However, the first direction changing members 10, 19 are configured to be rotatable in synchronization with each other by the driving means 4. Specifically, the first direction changing members 10, 19 are arranged at a slight incline with respect to the conveying direction of the package so that the first conveying member 5 and the second conveying member 6 extend from the inlet 1a to the outlet 1b of the main body 1.

The second direction changing members 11, 20 of the first support section 7 and the second support section 8 are arranged horizontally, but as described below, the first conveying member 5 and the second conveying member 6 are different members because they extend from the inlet 1a to the outlet 1b of the main body 1. However, the second direction changing members 11, 20 are configured to be rotatable in synchronization with each other. Specifically, the second direction changing members 11, 20 are arranged at a slight incline with respect to the conveying direction of the package so that the first conveying member 5 and the second conveying member 6 extend from the inlet 1a to the outlet 1b of the main body 1.

The driving means 4 is configured to rotate the first conveying member 5 and the second conveying member 6. Specifically, as shown in FIG. 1, the driving means 4 is configured so that the driving force from the driving source 4a (here, a motor) is transmitted via a transmission member 4b to a common rotating shaft to which the first direction changing members 10, 19 of the first support portion 7 and the second support portion 8 are attached.

The driving means 4 is also configured to be able to adjust the rotation speed of the first conveying member 5 and the second conveying member 6. Specifically, the driving means 4 includes a speed adjustment means 4c (here, an inverter) that changes the rotation speed of the drive shaft of the motor, which is the driving source 4a, and a drive control unit (not shown) that controls the speed adjustment means 4c.

As described above, the first conveying member 5 and the second conveying member 6 are arranged in parallel with a predetermined distance d1, d2 in the direction substantially perpendicular to the conveying direction of the package, i.e., in the width direction (see FIG. 3). The predetermined distances d1, d2 will now be described. That is, the first conveying member 5 and the second conveying member 6 are relatively widened in the width direction from the entrance 1a to the exit 1b of the main body 1. Specifically, by widening the guide portions 9a, 9b and the guide portions 18a, 18b with respect to the platform portion 27, the distance between the first conveying member 5 and the second conveying member 6 is widened from the start at the entrance 1a to the end at the exit 1b.

In other words, the guides 9a, 9b and horizontal support member 26, and the guides 18a, 18b and horizontal support member 26 are arranged on the platform 27 so as to spread relatively from the entrance 1a of the main body 1 toward the exit 1b, thereby causing the first conveying member 5 and the second conveying member 6 to spread from the entrance 1a toward the exit 1b. In this case, the first conveying member 5 and the second conveying member 6 spread in the width direction at a constant inclination with respect to the center of the width of the main body 1. In other words, the pair of first conveying members 5 and second conveying members 6 have a wide portion 30 that is a predetermined distance wider, and a narrow portion 31 that is a predetermined distance narrower than the wide portion 30, as shown in FIG. 3.

To be more specific, the length in the conveying direction from the entrance 1a to the exit 1b of the main body 1 is 2400 mm, the narrow portion 31 is 40 mm (spacing d1), the wide portion 30 is 50 mm (spacing d2), and the width is increased by 10 mm from the entrance 1a to the exit 1b of the main body 1. Note that the 10 mm dimension from the entrance 1a to the exit 1b is the conveying direction length from the entrance 1a to the exit 1b of the main body 1, and since the distance between the second direction change members 11, 20 and the first direction change members 10, 19 is longer than the conveying direction length of the main body 1 as shown in FIG. 1, the distance between the second direction change members 11, 20 and the first direction change members 10, 19 is set slightly wider than the 10 mm dimension capacity.

As such, the pair of first conveying members 5 and second conveying members 6 are configured with width expanding sections 32, 32 that gradually widen from a narrow section 31 to a wide section 30 from the entrance 1a side of the main body 1 toward the exit 1b side, as shown in FIG. 3.

The above is an explanation of the configuration of the heat shrink device for heat shrinkable packaging materials according to this embodiment. Next, the operation of the heat shrink device for heat shrinkable packaging materials according to this embodiment will be explained.

Here, as shown in Figs. 1 to 5, a case will be described in which the article X has a conical columnar shape (e.g., a cup container for instant noodles) whose diameter gradually decreases. That is, as shown in Fig. 8, the article X is transported with its central axis P aligned along the transport direction. Figs. 5, 7, and 8 show the state in which the article X has a conical columnar shape whose diameter gradually decreases and is wrapped in a film Y (shrink film), i.e., a package. In the film Y in Fig. 5, Ya is a vertical seal formed by the vertical seal section, and Yb is a horizontal seal formed by the horizontal seal section. Note that the article X does not have to be conical columnar, and the heat shrink device according to this embodiment can be used even if the article X has a cylindrical shape (e.g., a dry cell or an article made of a bundle of dry cells).

The heat shrinking device places the object X, which has been transported from a previous process facility (packaging device) located upstream, in a packaged state wrapped in film Y, across a first transport member 5 and a second transport member 6 that are arranged side by side and spaced apart in a direction approximately perpendicular to the transport direction. Specifically, the first transport member 5 and the second transport member 6 hold (hook) the package, which has a circular cross section, at their opposing ends 5c, 6c, and the package is partially fitted between the first transport member 5 and the second transport member 6 depending on the weight of the object X.

Therefore, even if the package attempts to swing in the width direction, a portion of the package is fitted into the first conveying member 5 and the second conveying member 6, so the first conveying member 5 and the second conveying member 6, at the position where they hold the package, prevent the package from swinging left and right in the conveying direction.

The package is then heated by the heating means 3 (including a heater and a fan) while being transported by the first transport member 5 and the second transport member 6 from the entrance 1a to the exit 1b, causing the film Y to thermally shrink toward the object X, so that the film Y takes on a shape that conforms to the object X.

Here, the positions of the first conveying member 5 and the second conveying member 6 for holding the package will be described. Also, as shown in FIG. 8, in the package inside the main body 1, the area below the item X, that is, the area of the film Y facing the lower area on the outer circumferential surface around the central axis P of the item X, is the facing area 33, the area of the film Y facing the upper area on the outer circumferential surface around the central axis P of the item X is the upward area 34, and the left and right areas disposed between the facing area 33 and the upward area 34 are the widthwise areas 35. In this embodiment, the facing area 33 is set at θ45° from the central axis P of the item X to the outer circumferential surface in the left-right direction. This facing area 33 is the area that comes into contact with the first conveying member 5 and the second conveying member 6.

The first conveying member 5 and the second conveying member 6 are spaced apart in the width direction at a constant incline from the inlet 1a of the main body 1 as shown in Figs. 3 and 4 to the outlet 1b as shown in Figs. 3 and 6. The first conveying member 5 and the second conveying member 6 are also spaced apart by width expansion sections 32, 32.

With this configuration, as the package is transported from the entrance 1a to the exit 1b, the width expansion sections 32, 32 gradually change the holding position of the package in its fitted state, but the positions at which the package is held by the first transport member 5 and the second transport member 6 are the ends 5c, 6c of the first transport member 5 and the second transport member 6 that face each other.

The positions of the ends 5c and 6c, when associated with the package, are within the area of the film Y that faces the conveying surface on the outer peripheral surface around the central axis P of the article X, that is, the facing area 33 of the film Y. In other words, the package is conveyed within the facing area 33 that corresponds to the ends 5c and 6c.

As the package moves in the conveying direction, the state in which the film Y is embedded gradually changes due to the weight of the item X, and the embedded amount gradually increases, and the hot air from the fan of the heating means 3 hits the package evenly as the embedded amount increases.

As a result, as shown in Figure 7, the film Y of the package can be shrunk well while the package is being transported while being firmly supported, so that the film Y forms a package that conforms to the shape of the object X, and the object X wrapped in the film Y, i.e., the package, has a good appearance.

The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. The same applies to the specific configuration of each part.

In the above embodiment, the pair of first conveying members 5 and second conveying members 6 are configured with width expanding sections 32, 32 that gradually widen from narrow to wide from the entrance 1a side of the main body 1 toward the exit 1b side. However, it is also possible to have a width reducing section that gradually narrows from wide to narrow from the entrance 1a side toward the exit 1b side. Even with this configuration, the hot air from the fan by the heating means 3 narrows the position where it hits the package (the position where it hits changes), contrary to the above embodiment, and the hot air hits even the original position, so that the hot air hits the package (film Y) evenly.

In the above embodiment, the spacing between the wide portions 30 and the narrow portions 31 is constant. However, a spacing difference adjustment means can be provided that can adjust the spacing difference between the wide portions 30 and the narrow portions 31. For example, the first direction change members 10, 19 can be configured to be relatively movable toward and away from each other in the horizontal direction. The second direction change members 11, 20 can also be configured to be relatively movable toward and away from each other in the horizontal direction. Alternatively, the first direction change members 10, 19 and the second direction change members 11, 20 can be configured to be relatively movable toward and away from each other in the horizontal direction.

Furthermore, it is possible to make the wide portion 30 wider or narrower than the narrow portion 31. Conversely, it is also possible to make the narrow portion 31 wider or narrower than the wide portion 30.

The heat shrink device equipped with this gap difference adjustment means makes it possible to adjust the gap difference, so that when the package is transported by the first transport member 5 and the second transport member 6, the state in which the package is fitted changes, allowing hot air to be applied evenly to the package in accordance with its shape.

In the above embodiment, an example was given in which the first conveying member 5 and the second conveying member 6 expand in the width direction at a constant inclination with respect to the center of the width direction of the main body 1. However, it is also possible to incline either the first conveying member 5 or the second conveying member 6.

In the above embodiment, an example was given in which the first and second conveying members 5 and 6 have a double belt conveying portion and are arranged side by side at a distance to form a long conveying path for packages. However, the first and second conveying members 5 and 6 can also be formed in the order of wide to narrow and narrow to wide from the entrance 1a to the exit 1b. In this case, the portion from the wide to narrow portion is the reduced width portion, and the portion from the narrow to wide portion is the expanded width portion.

Furthermore, the first conveying member 5 and the second conveying member 6 can be parallel members with only a narrow portion and parallel members with only a wide portion, and the narrow and wide portions between them can be connected by an expanded or contracted portion.

1...Main body, 1A...Transport space, 1a...Inlet, 1b...Outlet, 2...Transport section, 3...Heating means, 4...Driving means, 5...First transport member, 5b...Transport surface, 6...Second transport member, 6a...Center, 6b...Transport surface, 9a, 9b...Guide section, 18a, 18b...Guide section, 27...Platform, 30...Wide section, 31...Narrow section, 32, 32...Width expansion section, 33...Facing area, P...Central axis, X...Item, Y...Film, d1, d2...Predetermined interval

Claims (4)

The heating device includes a heating device main body having an entrance and an exit and capable of discharging hot air between the entrance and the exit, and a conveying unit that conveys a packaged product in which an object to be packaged is packaged with a packaging material in a conveying direction from the entrance to the exit,
A heat shrinking device that blows hot air onto the package conveyed by the conveying unit in a conveying direction from the carry-in entrance to the carry-out exit, thereby shrinking the packaging material of the package toward the packaged object,
The conveying section includes a pair of conveying members that are arranged at an interval in the width direction, and the package to be conveyed is placed across the pair of conveying members,
The pair of conveying members are
a narrow portion where the interval is narrower than a predetermined interval;
a wide portion provided on the outlet side in the conveying direction with respect to the narrow portion, the wide portion being wider than a predetermined distance ;
a width expanding portion in which the interval gradually increases from the narrow portion to the wide portion;
A heat shrinking apparatus comprising: 2. The heat shrinking device according to claim 1, wherein the pair of conveying members includes a width reducing portion in which the gap between the pair of conveying members gradually narrows from the narrow portion toward the inlet or from the wide portion toward the outlet. The pair of conveying members each have a conveying surface on which the package is placed,
The package is configured by wrapping the cylindrical packaged object, which is transported with its central axis aligned along a transport direction, in the sheet-like packaging material,
3. The heat shrink device according to claim 2, wherein the width expanding portion and the width reducing portion contact the package within an opposing region that faces the conveying surface on an outer peripheral surface of the package around the central axis. The heat shrinking device according to any one of claims 1 to 3, further comprising a gap difference adjustment means capable of adjusting the gap difference between the wide portion and the narrow portion.