JP3907436B2 - Heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heating device for heating a film having heat shrinkability mounted on an object.
[0002]
[Prior art]
Conventionally, a heat-shrinkable film (hereinafter referred to as “shrink film”) formed of polyethylene, polypropylene, PVC, or the like has been used as a product packaging or a label wrapped around a product. The shrink film is heated in a state where it is attached to the product and is in close contact with the product by shrinking. As a result, it is possible to easily and firmly carry out product packaging and label attachment.
[0003]
As a method of heating the shrink film, there are a method of immersing a product equipped with the shrink film in hot water, a method of leaving the product in steam for a long time, a method of exposing to hot air, and the like.
[0004]
[Problems to be solved by the invention]
By the way, among these methods of heating the shrink film, the method of immersing the product in hot water can be used only for products that may be immersed in hot water. In addition, the method of leaving in the steam has a low heating efficiency of the shrink film, and it is necessary to leave the product in the steam for a long time. As a result, in order to incorporate a heating device for shrink film in a line through which goods flow, it is necessary to make the device very long. Furthermore, since it is necessary to fill the inside of the heating device with steam, there is a problem that the power consumed by the device also increases.
[0005]
The technique of exposing the shrink film to hot air has an advantage that the shrink film can be efficiently heated. However, it is difficult to uniformly heat the entire shrink film, and there is a problem that wrinkles are generated in the film after shrinkage or uneven shrinkage is likely to occur.
[0006]
Japanese Patent Application Laid-Open No. 8-183518 discloses a heating apparatus in which air in the apparatus is heated using a panel heater, and the heated air is ejected toward a product using an air distribution pipe. . In this heating device, a measure is taken to rotate the product on the conveyor in order to uniformly heat the entire shrink film. As a result, a special conveyor that complicates the apparatus structure is required, and the apparatus cost increases.
[0007]
This invention is made | formed in view of the said subject, and when heating a shrink film with a hot air, it aims at heating the whole film appropriately with a simple structure.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is a heating device for heating a heat-shrinkable film mounted on an object, supporting preheating means for preliminarily heating the object, and supporting the object A support means for conveying the object from the preheating means to the heating position and passing the heating position; and three or more sending means for sending hot air each, wherein the three or more sending means are the heating positions. Are arranged so as to surround a reference axis facing a predetermined direction, and each of the three or more sending means sends hot air in a direction inclined to the same side with respect to the direction toward the reference axis .
[0010]
According to a second aspect of the invention, a heating apparatus according to claim 1, wherein three or more of the delivery means are arranged at equal intervals around the reference axis.
[0011]
A third aspect of the present invention is the heating apparatus according to the first or second aspect , wherein each of the three or more delivery means is disposed at a substantially end portion of the object located at the heating position as viewed from the delivery means. The hot air is sent out.
[0012]
The invention described in claim 4 is the heating apparatus according to any one of claims 1 to 3, each of the three or more delivery means in a direction inclined 30 ° or less from the direction toward the reference axis Hot air is sent out.
[0013]
Invention of Claim 5 is a heating apparatus in any one of Claim 1 thru | or 4 , Comprising: Each of the said 3 or more sending means has a nozzle in which the delivery port from which a hot air is sent was formed. .
[0014]
A sixth aspect of the present invention is the heating apparatus according to the fifth aspect , further comprising an air supply means for supplying air to the three or more delivery means and a heating means for heating the air.
[0015]
The invention described in claim 7 is the heating apparatus according to any one of claims 1 to 6, a film having a tubular heat-shrinkable is attached to the object, the film is said in the heating position Located so as to surround the reference axis.
[0018]
Invention of Claim 8 is a heating apparatus which heats the film which has the heat-shrink property with which the target object was mounted | worn, Comprising: The conveyance means which conveys a target object along a predetermined | prescribed conveyance path, and the said conveyance path First heating means for preliminarily heating the object by sending hot air toward the object to be conveyed; and second heating means for performing main heating on the object to be conveyed on the conveyance path And the first heating means alternately forms a plurality of hot air velocity regions and low air velocity regions along the conveyance path.
[0019]
A ninth aspect of the present invention is the heating apparatus according to the eighth aspect , wherein the first heating means is disposed along the transport path and blows hot air from an opening member in which a large number of openings are formed. The opening member is alternately provided with a region having a large opening area per unit area and a region having a small opening area along the transport path.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front view of a heating apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a left side view. In the following description, X, Y, and Z directions shown in the drawings are referred to as appropriate.
[0021]
The heating device 1 has a configuration in which a conveyor 12, a preheating unit 13, and a main heating unit 14 are arranged on a frame 11. As shown in FIG. 1, the conveyor 12 rotates the two rollers 121 and 122 so that the upper part of the belt 123 moves in the (+ X) direction. Thereby, the product 9 (the plastic bottle is illustrated in FIG. 1) to which the shrink film 91 having heat shrinkability is attached is conveyed in the (+ X) direction while being supported by the belt 123 from below.
[0022]
The preheating unit 13 and the main heating unit 14 are provided so as to cover the conveyance path of the conveyor 12, and the product 9 to be conveyed is sequentially guided into the preheating unit 13 and the main heating unit 14. In FIGS. 1 and 2, illustration of a cover that covers the periphery of the frame 11 and the conveyor 12 is omitted, and a cover 15 that covers the preheating unit 13 and the main heating unit 14 is indicated by a two-dot chain line.
[0023]
Inside the frame 11, a fan 131 that supplies air to the preheating unit 13 and a fan 141 that supplies air to the main heating unit 14 are arranged. As shown in FIG. 2, a heater 132 is connected to the fan 131, and air heated by the heater 132 is supplied to the preheating unit 13 through supply pipes 133 and 134. On the other hand, air from the fan 141 shown in FIG. 1 is supplied to the main heating unit 14 via the supply pipe 142. The air to the main heating unit 14 is also heated by the heater above the main heating unit 14, and details will be described later. The two fans 131 and 141 receive air flowing from below the preheating unit 13 and the main heating unit 14 to the lower side of the conveyor 12.
[0024]
Further, a control unit 16 for controlling the operation of the conveyor 12 and heating by the preheating unit 13 and the main heating unit 14 is also arranged in the frame 11.
[0025]
FIG. 3 is a diagram illustrating a state in which the shrink film 91 before shrinkage is attached to the product 9. As shown in FIG. 3, the shrink film 91 is generally cylindrical and is mounted so as to surround the side surface of the product 9. And the goods 9 with which the shrink film 91 was mounted | worn are handled in the heating apparatus 1 as a heating target object.
[0026]
When the product 9 is transferred from the upstream device to the conveyor 12 of the heating device 1, the product 9 is conveyed into the preheating unit 13 and preliminarily heated until the temperature immediately before the shrink film 91 starts to shrink. The That is, the shrink film 91 is heated to the vicinity of the shrinkage start temperature by the preheating unit 13. Thereafter, the product 9 is conveyed from the preheating unit 13 to the main heating unit 14 by the conveyor 12, and further heating is performed by the main heating unit 14 so that the shrink film 91 is contracted. As shown in FIG. It adheres to the side surface of 9. The heated product 9 is unloaded from the main heating unit 14 by the conveyor 12 and unloaded toward the downstream apparatus.
[0027]
FIG. 5 is a view showing a cross section of the preheating portion 13 taken along the YZ plane. Inside the cover 21 of the preheating part 13, an air blowing part 22 that is long in the X direction is arranged across the conveyor 12, and the product 9 is conveyed between the two air blowing parts 22. A supply pipe 134 is connected to the upper part of the blower unit 22, and an opening plate 221 having a large number of openings is attached to the surface of the blower unit 22 on the product 9 side. Therefore, when the air heated by the fan 131 and the heater 132 shown in FIG. 2 is supplied into the blower 22 through the supply pipe 134, the product 9 (particularly, the shrink film 91) is opened from the opening of the opening plate 221. Hot air is sent out.
[0028]
FIG. 6 is a diagram showing a state when one blower 22 is viewed from the opening plate 221 side. The opening plate 221 has openings 221a arranged in the Z direction and openings 221b arranged in the Z direction, and these openings 221a and 221b are alternately formed in the X direction. The opening 221a has a relatively larger diameter than the opening 221b, and when heated air is supplied from the supply pipe 134, hot air having a higher wind speed than the vicinity of the opening 221b is generated in the vicinity of the opening 221a. As a result, a plurality of regions where the hot air velocity is high and regions where the hot air velocity is low are alternately formed along the conveyance path on the conveyance path of the product 9.
[0029]
As described above, the openings 221a and 221b having two kinds of sizes are alternately formed, so that when the product 9 is conveyed on the conveyor 12, the wind speed of the hot air applied to the shrink film 91 is changed. Thereby, the direction of the airflow on the surface of the shrink film 91 can be changed, and it is realized that the entire shrink film 91 is uniformly heated (preheated) as compared with the case where a certain amount of hot air is applied to the shrink film 91. . Moreover, since the magnitude | size and direction of the wind pressure given to the shrink film 91 change, it suppresses carrying in to the main heating part 14 with the shrink film 91 mounted in the state biased with respect to the goods 9. Is also realized.
[0030]
FIG. 7 is a plan view showing the structure of the main heating unit 14, and FIG. 8 is a front view. Two heaters 32 are provided above the cover 31 of the main heating unit 14, and as shown in FIG. 8, a supply pipe 143 is connected to the heater 32 to supply air from the fan 141 (see FIG. 1). . The air heated by the heater 32 is guided to the four nozzles 34 through the piping 33 as shown in FIG. That is, each of the two pipes 33 from the heater 32 is separated into two paths so as to sandwich the conveyor 12, passes through the cover 31, and is connected to the four nozzles 34. In FIG. 8, only the two front nozzles 34 are shown.
[0031]
7 and 8 is supported by the conveyor 12 at a position where the shrink film 91 is heated most efficiently by the four nozzles 34 (hereinafter referred to as “heating position”). It shows a state. At this time, assuming a virtual axis (hereinafter referred to as “reference axis”) 8 passing through the center of the product 9 in the Z direction at the heating position, the four nozzles 34 surround the circumference of the reference axis 8, etc. It arrange | positions at a space | interval (equal space | interval with respect to the circumferential direction of the reference shaft 8), and the shrink film 91 is located so that the reference shaft 8 may be enclosed in a heating position.
[0032]
FIG. 9 is a view showing a state when the nozzle 34 is viewed from the air outlet 341 side. The vertical direction in FIG. 9 corresponds to the Z direction in FIGS. FIG. 10 is a sectional view of the nozzle 34 at the position indicated by the arrow AA in FIG. As shown in FIG. 10, the air from the pipe 33 is once guided to the space 342 behind the delivery port 341. A rectifying plate 343 having a plurality of openings 3431 is disposed between the delivery port 341 and the space 342. As shown in FIG. 9, the plurality of openings 3431 of the rectifying plate 343 are gradually reduced downward, whereby hot air is uniformly sent from the slit-shaped outlet 341 that is long in the vertical direction.
[0033]
The length of the outlet 341 is set to be longer than the length of the shrink film 91 in the Z direction, so that hot air is sufficiently applied to the upper and lower portions of the shrink film 91 (see FIG. 8).
[0034]
FIG. 11 is a diagram for explaining the relationship between the orientation of the nozzle 34 and the product 9 located at the heating position. As shown in FIG. 11, each nozzle 34 does not send hot air toward the center of the commodity 9 located at the heating position, but sends hot air toward the inclined direction. Specifically, assuming the reference shaft 8 facing the Z direction at the heating position where the product 9 is located, each nozzle 34 sends hot air in a direction inclined to the same side with respect to the direction toward the reference shaft 8. FIG. 11 shows a state in which hot air is sent in a direction inclined by an angle θ in the XY plane with respect to the direction toward the reference axis 8.
[0035]
Thereby, the hot air flow F1 sent out from the four nozzles 34 forms a vortex while interfering with each other, and the hot air flows along the surface of the shrink film 91 attached to the product 9. As a result, the entire surface of the shrink film 91 is heated quickly and uniformly, and the occurrence of wrinkles and uneven shrinkage is prevented.
[0036]
Even if the angle θ is small, an airflow along the periphery of the shrink film 91 can be generated. However, it is preferable that the hot air is sent out toward almost the end of the product 9 located at the heating position as seen from each nozzle 34. If the direction of the nozzle 34 is specified by the angle θ, it is preferable that the hot air is sent within a range where the angle θ is 30 ° or less, depending on the shape and size of the product 9. Of course, since the hot air from the nozzle 34 is guided to the product 9 while spreading, the angle θ is only an index indicating the center of the direction of the hot air.
[0037]
The air that forms a vortex around the shrink film 91 of the product 9 is guided downward from the side of the conveyor 12 and taken into the fan 141 again. In this way, the air from the nozzle 34 is guided downward (or upward), so that the vortex formation state can be improved.
[0038]
In addition, since the conveyor 12 passes the heating position while supporting the product 9 as shown in FIG. 7, the time during which the heated air vortex is formed around the shrink film 91 is short. And the efficient and uniform heating using a vortex is performed with respect to the shrink film 91 in this short time, and shrinkage | contraction of the appropriate shrink film 91 is implement | achieved.
[0039]
Moreover, since the shrink film 91 can be shrunk in a short time in the heating device 1 as compared with the conventional method using steam, the length of the heating device 1 is increased even if the heating device 1 is incorporated in the conveyance line of the product 9. The length can be kept short. Specifically, it is possible to reduce the length of the heating device 1 to half or less as compared with the case of using steam.
[0040]
Further, the main heating unit 14 does not heat the entire interior, but only the air blown to the product 9 by the heater 32 is heated, so that it is possible to reduce energy consumption.
[0041]
In the main heating unit 14 of the heating apparatus 1 described above, the shrink film 91 is efficiently heated by generating hot air vortex around the product 9. Note that the hot air vortex refers to an airflow that flows along the surface of the object to be heated, and whether or not such hot air vortex is generated is determined by using yarn or smoke near the surface of the object to be heated. When the direction is detected, it can be confirmed that the direction of the airflow is in a certain direction around the reference axis 8. Of course, the hot air blown onto the product 9 will eventually leave the surface of the product 9, so the hot air vortex does not have to be clearly recognizable as a vortex that makes one or more revolutions around the product 9. For example, the airflow sent from one nozzle 34 may flow so as to move away from the surface of the product 9 after being blown only about 1/4 of the surface of the product 9.
[0042]
Further, although the hot air is vigorously sent from the nozzle 34 in the main heating unit 14, the hot air vortex is formed by any method as long as the hot air vortex can be generated around the product 9. May be. That is, hot air does not need to be sent out from the nozzle, and air heated by an individual heater does not need to be sent out through the piping.
[0043]
FIG. 12 is a diagram showing another form of the main heating unit that generates a vortex of hot air. In the main heating unit 14a shown in FIG. 12, the entire air in the main heating unit 14a is heated by the heater 32a. And the air in this heating part 14a is sent toward the goods 9 with the four fans 34a. The center of the airflow F2 from the fan 34a is set so as to be directed in the direction inclined to the same side by a predetermined angle θ with respect to the reference axis 8 as in the main heating unit 14 of FIG. Thereby, a vortex is formed around the product 9 while the airflows F2 interfere with each other. As described above, any method may be used as long as a hot air vortex can be generated in the main heating unit.
[0044]
8 shows a case where hot air is blown onto the product 9 from the horizontal direction, the hot air does not need to be sent in a direction perpendicular to the reference axis 8 (a direction perpendicular to the twist). As shown in FIG. 13, the delivery port of the nozzle 34 may be inclined downward (that is, the exhaust side of the main heating unit 14). Thereby, the downward vortex by the airflow F3 can be formed on the surface of the shrink film 91 attached to the product 9, and the hot air can be efficiently circulated.
[0045]
Furthermore, the reference axis 8 serving as a reference in the formation of the vortex does not need to face the vertical direction, and may be inclined with respect to the direction of the central axis of the cylindrical shrink film 91. Of course, in order to efficiently heat the cylindrical shrink film 91, it is preferable that the shrink film 91 surrounds the reference shaft 8 at the heating position. Further, the reference axis 8 itself does not need to be oriented in the vertical direction, and may be oriented in the horizontal direction.
[0046]
FIG. 14 is a diagram illustrating the main heating unit 14b in which the reference axis 8 faces the horizontal direction. In addition, the same code | symbol is attached | subjected to the structure similar to this heating part 14 shown in FIG. In the main heating unit 14b, the product 9 moves so as to roll while slowly rotating on the slope 12b. As shown in FIG. 15, the slope 12 b has two rails so as not to contact the shrink film 91 attached to the product 9. Two nozzles 34 are arranged above and below the slope 12b, and form a vortex of hot air around the reference axis 8 facing in the horizontal direction. Therefore, when the product 9 rolling on the slope 12b passes through the vortex of hot air, the shrink film 91 is efficiently and uniformly heated and contracts.
[0047]
As mentioned above, although embodiment which concerns on this invention has been described, this invention is not limited to the said embodiment, A various deformation | transformation is possible.
[0048]
The product to be heated and the shrink film may be any shape, and may have any shape. The shrink film may be longer than the length of the product. In this case, the shrink film is mainly used for packaging. Furthermore, a shrink film is not limited to a cylindrical thing, A bag shape may be sufficient.
[0049]
In the above embodiment, it has been described that only one hot air vortex is formed in the heating device 1, but a plurality of heating units are arranged along the conveyance path according to the size of the heating target and the output of the heater 32. Also good.
[0050]
The main heating unit in the above embodiment can also be used in a heating device that supports a product without conveying it. Moreover, the support of goods is not limited to the support from the lower side, and may be supported from the upper side or the side.
[0051]
In the main heating unit in the above embodiment, four nozzles 34 and four fans 34a are provided. However, in order to generate hot air vortices, there may be three or more mechanisms for sending hot air such as the nozzles 34 and the fan 34a.
[0052]
Further, the nozzle 34 may be a nozzle of another form. For example, the delivery port 341 of the nozzle 34 may be square or circular. Furthermore, a plurality of delivery ports may be arranged in one nozzle.
[0053]
In addition, air is supplied to the nozzle 34 by the fan 141, and the supplied air is heated by the heater 32. However, a compressor may be used instead of the fan 141, and the heater 32 uses various types of heaters. Is possible.
[0054]
In the preheating unit 13 in the above embodiment, openings 221a and 221b having different sizes are formed in the opening plate 221, but regions where the hot air velocity is high and regions where the wind velocity is low are alternately formed along the conveyance path. If possible, the aperture plate 221 may be arbitrarily modified.
[0055]
For example, by increasing the pitch of the openings formed in the aperture plate 221 in the conveyance direction, even if only openings having the same diameter are formed in the aperture plate 221, the hot air speed is high along the conveyance path. Regions and regions with low wind speed can be formed alternately. Also, regions having different wind speeds can be formed along the transport path by changing the density of the number of openings along the transport direction. Furthermore, regions having different wind speeds can be formed by alternately arranging ventilation plates and filters having different fluid resistances along the conveyance path. That is, by disposing a member in which a region having a large opening area per unit area and a region having a small opening area are alternately provided along the conveyance path, a region where the wind speed of hot air is high along with the conveyance path Low regions can be formed alternately.
[0056]
【The invention's effect】
According to the first to seventh aspects of the invention, the film having heat shrinkability can be efficiently and uniformly heated using hot air, and the heating device for conveying the object can be shortened.
[0057]
In the invention of claim 6 , energy consumption can be suppressed.
[0058]
In the inventions of claims 8 and 9 , preheating can be appropriately performed.
[Brief description of the drawings]
FIG. 1 is a front view of a heating device.
FIG. 2 is a side view of a heating device.
FIG. 3 is a diagram illustrating a shrink film before shrinkage.
FIG. 4 is a diagram illustrating a shrink film after shrinkage.
FIG. 5 is a cross-sectional view of a preheating portion.
FIG. 6 is a view showing an aperture plate.
FIG. 7 is a plan view of the main heating unit.
FIG. 8 is a front view of the main heating unit.
FIG. 9 is a diagram illustrating a nozzle.
FIG. 10 is a cross-sectional view of a nozzle.
FIG. 11 is a diagram for explaining the arrangement of nozzles and the state of airflow generation.
FIG. 12 is a diagram showing another example of the main heating unit.
FIG. 13 is a diagram showing still another example of the main heating unit.
FIG. 14 is a diagram showing still another example of the heating unit.
FIG. 15 is a diagram showing products on a slope.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heating apparatus 8 Reference | standard axis | shaft 9 Goods 12 Conveyor 12b Slope 13 Preheating part 32 Heater 32a Heater 34 Nozzle 34a Fan 91 Shrink film 141 Fan 221 Opening plate 221a, 221b Opening 341 Outlet

Claims (9)

A heating device for heating a heat-shrinkable film attached to an object,
A preheating means for preliminarily heating the object;
Supporting means for transporting the object from the preheating means to the heating position while passing the heating position while supporting the object ;
Three or more delivery means each delivering hot air;
With
The three or more delivery means are arranged so as to surround a reference axis facing a predetermined direction at the heating position,
Each heating apparatus characterized by delivering hot air in a direction inclined on the same side with respect to a direction toward the reference axis of the three or more delivery means. The heating device according to claim 1 ,
The heating apparatus, wherein the three or more delivery means are arranged at equal intervals around the reference axis. The heating device according to claim 1 or 2 ,
Each of the three or more delivery means delivers hot air toward substantially the end of the object located at the heating position as seen from the delivery means. The heating device according to any one of claims 1 to 3 ,
Each of the three or more delivery means delivers hot air in a direction inclined by 30 ° or less from a direction toward the reference axis. The heating device according to any one of claims 1 to 4 ,
Each of the three or more delivery means has a nozzle having a delivery port through which hot air is delivered. The heating device according to claim 5 ,
Air supply means for supplying air to the three or more delivery means;
Heating means for heating the air;
The heating apparatus further comprising: The heating device according to any one of claims 1 to 6 ,
A film having a cylindrical heat-shrink property is attached to the object,
The heating apparatus, wherein the film is positioned so as to surround the reference axis at the heating position. A heating device for heating a heat-shrinkable film attached to an object,
Conveying means for conveying an object along a predetermined conveying path;
First heating means for preliminarily heating the object by sending hot air toward the object to be conveyed along the conveyance path;
A second heating means for performing main heating on the object conveyed through the conveyance path;
With
The heating apparatus, wherein the first heating unit alternately forms a plurality of regions where the hot air velocity is high and regions where the wind velocity is low along the conveyance path. A heating device according to claim 8 ,
The first heating means is arranged along the transport path and sends hot air from an opening member in which a large number of openings are formed,
The heating apparatus, wherein the opening member is provided with a region having a large opening area per unit area and a region having a small opening area alternately along the conveyance path.

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