Heating device and method for producing can body

Abstract

Provided is a heating device for heating a can body by hot air, said heating device comprising: a heating unit for generating hot air; a first heating part for heating and increasing the temperature of the can body by using the hot air; and a second heating part for heating the can body which has been heated and had the temperature thereof increased. At least one of the first heating part and the second heating part may have a plurality of heating sections which have different heating conditions for the can body.

Description

Heating device and method for manufacturing can body

[0001] The present invention relates to a heating device and a method for manufacturing a can body.

[0002] Non-Patent Document 1 discloses a "DI can dryer oven using a clean heating source." [Prior art documents] [Non-Patent documents] Non-Patent Document 1: Japanese Utility Model Application Publication No. 07-032487 General disclosure

[0003] (Problem to be solved) To provide a heating device for a can body with excellent energy efficiency. (Means for solving the problem)

[0004] In a first aspect of the present invention, there is provided a heating device for heating a can body with hot air, the heating device including a heating unit that generates hot air, a first heating section that heats the can body to a higher temperature with the hot air, and a second heating section that heats the can body that has been heated to a higher temperature. At least one of the first heating section and the second heating section may have a plurality of heating sections with different heating conditions for the can body.

[0005] In the heating device, the second heating section may heat the heated can body and maintain the temperature at a predetermined level.

[0006] In any of the heating devices described above, the heating unit may be an electric heater for generating the hot air.

[0007] In any of the heating devices described above, the heating device may include a plurality of heating units that generate the hot air, and each of the plurality of heating sections may be provided with at least one of the plurality of heating units.

[0008] In any of the heating devices described above, at least one heating section of the plurality of heating sections may be provided with two or more of the heating units.

[0009] In any of the heating devices described above, the temperature of at least one heating section of the first heating section may be higher than the temperature of the heating section of the second heating section.

[0010] In any of the heating devices described above, the amount of air supplied from the heating unit in the first heating section may be greater than the amount of air supplied from the heating unit in the second heating section.

[0011] Any of the heating devices described above may include a plurality of exhaust units provided corresponding to the plurality of heating sections for exhausting the hot air, and the plurality of exhaust units may adjust the exhaust volume for each of the plurality of heating sections provided with the plurality of exhaust units.

[0012] In any of the heating devices described above, the exhaust volume of the last heating section of the plurality of heating sections of the first heating section may be larger than the exhaust volume of the first heating section of the plurality of heating sections of the first heating section.

[0013] In any of the heating devices described above, an exhaust volume of a first heating section among the plurality of heating sections of the second heating section may be larger than an exhaust volume of a last heating section among the plurality of heating sections of the second heating section.

[0014] In any of the heating devices described above, the plurality of heating sections may each have a circulation path that recovers the hot air that has heated the can body, reheats the hot air in the heating unit, and circulates the reheated hot air.

[0015] In any of the above heating devices, at least one of the plurality of heating sections may have a circulation path that reheats the hot air that has heated the can body in the heating unit and circulates it without exhausting the hot air.

[0016] In any of the heating devices described above, at least one of the plurality of heating sections may have a removal device for removing volatile components from the can body.

[0017] In any of the heating devices described above, the removal device may be provided in a first heating zone of the plurality of heating zones of the second heating section.

[0018] Any of the heating devices described above may further include a cooling section provided downstream of the second heating section for cooling the can body.

[0019] In any of the above heating devices, at least one heating section of the plurality of heating sections of the first heating section and / or at least one heating section of the second heating section may be capable of being assembled separately from the other heating sections.

[0020] In a second aspect of the present invention, there is provided a method for manufacturing a can body, the method including the steps of generating hot air for heating the can body, heating the can body to a temperature in a first heating section using the hot air, and heating the heated can body in a second heating section. At least one of the first heating section and the second heating section may have a plurality of heating sections with different heating conditions for the can body.

[0021] The method for manufacturing a can body may further include forming the can body from a resin-coated metal plate, and the first heating section and the second heating section may heat a resin-coated can in which the can body is coated with resin.

[0022] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions.

[0023] 1 shows an overview of the configuration of a manufacturing system 200. 2 shows an overview of the configuration of a heating device 100. 3 shows an example of the configuration of a heating device 100. 4 shows an example of a cross section of the heating device 100. 5 shows an example of a cross section of the heating device 100. 6 shows an example of a cross section of the heating device 100. 7 shows specific examples of an upper plate 91 and a lower plate 92.

[0024] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0025] 1 shows an overview of the configuration of a manufacturing system 200. The manufacturing system 200 has a can body production line 110 for producing can bodies 300. The can body production line 110 has a can body forming process 111, a pre-printing heating process 112, a printing process 113, a post-printing heating process 114, a neck forming process 115, and a packaging process 116. Note that, although the can body 300 in this example is a cylindrical metal can, the shape and material of the can body 300 are not particularly limited.

[0026] In the can body forming process 111, the can body structure of the can body 300 is formed from a plate-shaped preliminary material. The can body forming process 111 may include a step of forming the can body 300 from a resin-coated metal plate. In this example, the can body forming process 111 includes a cupping press process (CP), a body maker process (BM), and a trimmer process (TR).

[0027] In the cupping press process (CP), a circular blank is punched out of a sheet metal preform unwound from a coil to form a cup shape. The preform may be laminated with a resin film. In the body maker process (BM), the cup-shaped blank C1 is drawn and ironed to form a thin can body, and then the can bottom is formed to form a can body C2. Note that the can body C2 may have an unnecessary upper end portion cut off in the trimmer process (TR).

[0028] The pre-printing heating step 112 includes a first heat setting step (HS1) for heating the can body 300. In the pre-printing heating step 112, the can body 300 may be heated using a heating device 100 described below.

[0029] The printing process 113 includes a printing process (PR) in which a predetermined image is printed on the can body 300. The image may be a symbol, a sign, a letter, a number, a figure, a color, or a combination of these, or a design formed by combining these. The content printed in the printing process (PR) is not particularly limited. In the printing process (PR), painting and printing may be performed on the can body of the can body C2.

[0030] The post-printing heating step 114 includes a second heat setting step (HS2) for heating the can body 300. The second heat setting step (HS2) may be a step of baking the printed ink onto the can body 300. The post-printing heating step 114 may heat the can body 300 using a heating device 100, which will be described later. The heating method of the post-printing heating step 114 may be the same as or different from the heating method of the pre-printing heating step 112. The heating conditions of the post-printing heating step 114 may be the same as or different from the heating conditions of the pre-printing heating step 112.

[0031] The neck forming step 115 includes a necking step (Ne), in which a mold is pressed against the upper part of the can body 300 to reduce the diameter of the upper part of the can body 300.

[0032] The packaging process 116 packages the manufactured can bodies 300. The packaging process 116 may include a palletizing process (Pa) in which the can bodies 300 are loaded onto pallets.

[0033] The manufacturing system 200 may include a filling process for filling a predetermined filling material into the can body 300. The filling process may include a process for attaching a lid to the can body 300 filled with the filling material.

[0034] 2 shows an outline of the configuration of the heating device 100. The heating device 100 includes a first heating section 10, a second heating section 20, a cooling section 30, and a heating unit 40.

[0035] The heating device 100 heats the can body 300 with hot air. The heating device 100 of this example heats the can body 300 by transporting it through the first heating section 10 and the second heating section 20 in that order. The heating device 100 may heat the can body 300 in the first heating section 10 and the second heating section 20, and then cool it in the cooling section 30.

[0036] The first heating section 10 uses hot air to heat the can body 300. The first heating section 10 may heat the can body 300 transported from the can body forming process 111, or may heat the can body 300 transported from the pre-printing heating process 112. The first heating section 10 may heat the can body 300 to raise the temperature of the can body 300 from room temperature to a predetermined temperature.

[0037] The second heating unit 20 heats the can body 300 that has been heated by the first heating unit 10. The second heating unit 20 may heat the can body 300 that has been heated and maintain a predetermined temperature. The second heating unit 20 may maintain the temperature of the can body 300 so that the temperature of the can body 300 falls within a predetermined temperature range. The second heating unit 20 may maintain the temperature of the can body 300 so that it does not fall below a predetermined temperature. For example, the second heating unit 20 maintains the temperature of the can body 300 so that it does not fall below the temperature of the can body 300 at the time of transport to the second heating unit 20. In this way, maintaining a predetermined temperature may include not only a case where the temperature of the can body 300 is constant, but also a case where the temperature of the can body 300 increases or decreases.

[0038] At least one of the first heating section 10 and the second heating section 20 may have multiple heating sections S with different heating conditions for the can body 300. In this example, the first heating section 10 and the second heating section 20 each have multiple heating sections S. In this specification, the term "heating section S" may refer to any one or more heating sections that the heating device 100 has.

[0039] The heating conditions may be at least one of the temperature, air volume, and heating time in the heating section S. The heating conditions may include the amount of air intake taken in from outside the circulation path 60, which will be described later, and may include the amount of exhaust air exiting the circulation path 60. The heating conditions may include the presence or absence of a device to be installed, such as the presence or absence of a removal device 70, which will be described later.

[0040] The first heating section 10 may have one or more heating sections Sa with different heating conditions for the can body 300. In this specification, the term "heating section Sa" may refer to any one or more heating sections possessed by the first heating section 10. In this example, the first heating section 10 has m heating sections Sa, namely heating section Sa(1) to heating section Sa(m), where m is an integer equal to or greater than 1. The first heating section 10 may have multiple heating sections Sa, and the temperature setting of the heating unit 40 may be changed for each heating section Sa depending on the temperature of the can body 300.

[0041] In this example, the first heating section 10 can shorten the temperature rise time by setting the temperature of the heating section Sa to be equal to or higher than the final temperature reached in the first heating section 10. Furthermore, shortening the temperature rise time can shorten the length of the first heating section 10. The first heating section 10 can suppress can temperature overshoot by setting the temperature of the latter heating section Sa of the multiple heating sections Sa lower than the temperature of the former heating section Sa.

[0042] The second heating unit 20 may have one or more heating sections Sb with different heating conditions for the can body 300. In this specification, the term "heating section Sb" may refer to any one or more heating sections that the second heating unit 20 has. In this example, the second heating unit 20 has n heating sections Sb, from heating section Sb(1) to heating section Sb(n), where n is an integer greater than or equal to 1. The number n of heating sections Sb in the second heating unit 20 may be the same as or different from the number m of heating sections Sa in the first heating unit 10. The number n of heating sections Sb in the second heating unit 20 may be smaller or larger than the number m of heating sections Sa in the first heating unit 10.

[0043] The cooling unit 30 is provided downstream of the second heating unit 20 and cools the can body 300. The cooling unit 30 may air-cool the can body 300, or may cool the can body 300 by a method other than air-cooling. The cooling unit 30 may cool the can body 300 so that the can body 300 reaches a predetermined temperature or lower within a predetermined time. For example, the cooling unit 30 may cool the can body 300 so that the can body 300 reaches a temperature of 80°C or lower within 20 seconds. Note that slow cooling of a resin-coated can may cause the resin to become brittle, but cooling the can body 300 in the cooling unit 30 can prevent a decrease in the strength of the can body 300. The cooling conditions may be changed depending on the material of the resin coating the can body 300.

[0044] The heating unit 40 generates hot air for heating the can body 300. The heating unit 40 may be an electric heater for generating hot air. By using an electric heater as the heating unit 40, it becomes easier to divide the heating device 100 into multiple heating sections S compared to a gas-type combustion device. When an electric heater is used as the heating unit 40, water is not generated by combustion as in a combustion device, so the can body 300 is more likely to dry.

[0045] The heating device 100 may include multiple heating units 40. At least one of the multiple heating units 40 may be provided in each of the multiple heating zones S. Furthermore, one heating unit 40 may be provided for multiple heating zones S with the same temperature. The heating device 100 of this example includes heating units 40a(1) to 40a(m) for blowing hot air to the first heating section 10 and heating units 40b(1) to 40b(n) for blowing hot air to the second heating section 20. In this specification, the term "heating unit 40a" may refer to one or more heating units 40 for blowing hot air to the first heating section 10. In this specification, the term "heating unit 40b" may refer to one or more heating units 40 for blowing hot air to the second heating section 20.

[0046] Heating units 40a(1) to 40a(m) are provided to correspond to heating sections Sa(1) to Sa(m), respectively, of first heating section 10. The volumes of hot air generated by heating units 40a(1) to 40a(m) may be the same or different.

[0047] Heating units 40b(1) to 40b(n) are provided to correspond to heating sections Sb(1) to Sb(n), respectively, of second heating section 20. The volumes of hot air generated by heating units 40b(1) to 40b(n) may be the same or different.

[0048] The heating device 100 may change the heating conditions of the heating sections S. The heating device 100 may change the heating conditions of the heating sections Sa of the first heating section 10, and may change the heating conditions of the heating sections Sb of the second heating section 20. By adjusting the heating conditions of the heating sections S according to the temperature of the can body 300, it is possible to improve energy efficiency.

[0049] For example, the air volume supplied from heating unit 40a in first heating section 10 is set to be larger than the air volume supplied from heating unit 40b in second heating section 20. By increasing the air volume supplied from heating unit 40a in first heating section 10, the temperature rise time of can bodies 300 can be shortened. When the number of can bodies 300 present in heating section S varies due to differences in the length of heating section S, for example, the air volume supplied from heating unit 40 may be compared using the air volume per can, i.e., the value obtained by dividing the air volume supplied to heating section S by the number of can bodies 300 present in that heating section S.

[0050] In this example, the air volumes supplied from the heating unit 40 were compared, but the comparison may also be made based on the air speed blown onto the can body 300, or on the circulation volume per can circulating through the circulation path 60 described below. The maximum air volume among the multiple heating sections Sa of the first heating section 10 may be greater than the minimum air volume among the multiple heating sections Sb of the second heating section 20. Furthermore, the minimum air volume among the multiple heating sections Sa of the first heating section 10 may be greater than the maximum air volume among the multiple heating sections Sb of the second heating section 20.

[0051] In the heating device 100 of this example, by providing a heating unit 40 for each heating section S, it is possible to set the temperature for each heating section S. The heating device 100 may set the temperature of at least one heating section Sa of the first heating section 10 higher than the temperature of the heating section Sb of the second heating section 20. Furthermore, by dividing the first heating section 10 into multiple heating sections Sa, the heating device 100 can set the air volume of the first heating section 10 to be greater than the air volume required to maintain the temperature in the second heating section 20. This allows the temperature rise time of the can body 300 to be shortened.

[0052] The heating device 100 may have a temperature sensor for measuring the temperature of the can body 300 for each heating section S. Alternatively, a thermocouple may be attached to the can body 300 to measure the temperature change of the can body 300. The heating device 100 may adjust the heating conditions of the can body 300 for each heating section S according to the measured temperature.

[0053] 3 shows an example of the configuration of the heating device 100. In this example, the first heating section 10, the second heating section 20, and the cooling section 30 are arranged side by side in the X-axis direction, and the can bodies 300 are transported in the X-axis direction. The can bodies 300 in this example are arranged at any intervals in the X-axis direction. Multiple can bodies 300 may also be arranged side by side in the Y-axis direction.

[0054] In this example, the first heating section 10 has four heating sections Sa, namely, heating section Sa(1) to heating section Sa(4). That is, the number m of heating sections Sa in the first heating section 10 is 4. The heating times of the heating sections Sa(1) to Sa(4) may be the same. That is, the lengths of the heating sections Sa(1) to Sa(4) in the traveling direction of the can body 300 may be the same. However, the heating times of the heating sections Sa(1) to Sa(4) may be different.

[0055] In this example, the second heating unit 20 has two heating sections Sb: heating section Sb(1) and heating section Sb(2). That is, the number n of heating sections Sb in the second heating unit 20 is 2. The heating times of the heating sections Sb(1) and Sb(2) may be the same or different. Note that the number of heating sections S in the first heating unit 10 and the second heating unit 20 is not limited to this example.

[0056] The can body 300 may be a resin-coated can coated with resin. The first heating section 10 and the second heating section 20 may heat the resin-coated can in which the can body 300 is coated with resin. Here, distortion may occur in the resin film coating the can body 300. The distortion caused in the resin film may be removed by heating with the heating device 100. Note that when the heating device 100 is used in the post-printing heating process 114, the can body 300 may be a printed can on which a predetermined image is printed.

[0057] The conveyor 80 transports the can bodies 300 in the order of the first heating section 10, the second heating section 20, and the cooling section 30. The can bodies 300 may be placed on the conveyor 80. The spacing between the can bodies 300 in the X-axis direction may be adjusted by utilizing the speed difference between the supply speed at which the can bodies 300 are supplied to the heating device 100 and the transport speed of the conveyor 80 of the heating device 100. The spacing between the can bodies 300 in the Y-axis direction may be controlled using an arbitrary sorting device to prevent the can bodies 300 from contacting each other.

[0058] The upper plate 91 is provided above the can body 300. The upper plate 91 may be provided in each of the first heating section 10, the second heating section 20, and the cooling section 30. The upper plate 91 will be described later.

[0059] The lower plate 92 is provided below the can body 300. The lower plate 92 may be provided below the conveyor 80 on which the can body 300 is placed. The lower plate 92 may be provided in each of the first heating section 10, the second heating section 20, and the cooling section 30. The lower plate 92 will be described later.

[0060] Here, the first heating unit 10, the second heating unit 20, and the cooling unit 30 may be assemblable separately from one another. At least one heating unit Sa of the multiple heating units Sa of the first heating unit 10 and / or at least one heating unit Sb of the heating units Sb of the second heating unit 20 may be assemblable separately from the other heating units S. That is, at least one of the multiple heating units Sa may be assemblable separately from the other heating units Sa. Similarly, at least one of the multiple heating units Sb may be assemblable separately from the other heating units Sb.

[0061] The ability to separate and assemble the heating device 100 improves transportation efficiency and facilitates installation of the device. Providing multiple heating units 40 reduces the size of each individual unit, improving transportation efficiency.

[0062] 4A shows an example of a cross section of the heating device 100. The heating device 100 of this example includes a heating unit 40 and an exhaust section 50 in the circulation path 60 of an arbitrary heating section S. This figure shows a YZ cross section of the heating device 100. Multiple can bodies 300 may be arranged at arbitrary intervals in the Y-axis direction as well. The intervals between the can bodies 300 may be controlled using an arbitrary sorting device so that the can bodies 300 do not come into contact with each other.

[0063] The circulation path 60 is provided in the heating section S and circulates the hot air generated by the heating unit 40. The circulation path 60 recovers the hot air that has heated the can body 300, reheats the hot air in the heating unit 40, and circulates it. In this example, the circulation path 60 blows the hot air generated in the heating unit 40 to the can body 300 via a supply port 61 and recovers the hot air that has heated the can body 300 via an exhaust port 62. The circulation path 60 may be provided in each of the multiple heating sections S. By providing the circulation path 60, the hot air that has heated the can body 300 can be reused without providing a heat exchanger.

[0064] The heating unit 40 is provided in the circulation path 60 and blows hot air from above the can body 300. The heating unit 40 may be provided on a side surface of the heating section S. That is, the heating unit 40a may be provided on a side surface of the first heating section 10, and the heating unit 40b may be provided on a side surface of the second heating section 20.

[0065] In this example, the can body 300 is placed in an inverted state on the conveyor 80 with the bottom of the can body 300 facing up. In this way, with the bottom, which has a higher weight ratio, facing up, hot air from the heating unit 40 is applied from above, thereby enabling the can body 300 to be heated efficiently. Furthermore, by transporting the can body 300 in an inverted state, the top of the can body 300, which has a larger diameter than the bottom, comes into contact with the conveyor 80. This increases the contact diameter with the conveyor 80, making the can body 300 less likely to tip over.

[0066] The exhaust section 50 is provided corresponding to the heating section S and exhausts hot air. The heating device 100 may include a plurality of exhaust sections 50 provided corresponding to a plurality of heating sections S. The plurality of exhaust sections 50 may adjust the exhaust volume for each of the plurality of heating sections S in which the plurality of exhaust sections 50 are provided. The exhaust section 50 may take in air from the outside and supply it to the circulation path 60. The heating unit 40 may take in air supplied from the outside in addition to the air circulating through the circulation path 60.

[0067] The exhaust section 50 may be provided at any position in the circulation path 60. In this example, the exhaust section 50 is provided between the heating unit 40 and the can body 300 in the circulation path 60. In this example, the exhaust section 50 is provided on the side of the heating section S, but is not limited to this.

[0068] Here, the can body 300 may contain volatile components such as wax that volatilize when heated. When the components volatilized by heating circulate through the circulation path 60, the concentration of the volatile components may increase. The heating device 100 of this example is provided with the exhaust unit 50, which allows the concentration of the volatile components to be adjusted.

[0069] The exhaust unit 50 may determine the exhaust volume according to the amount of volatilization of volatile components caused by heating the can body 300. The exhaust unit 50 may set the exhaust volume of the heating section S in which a larger amount of volatilization occurs from the can body 300 to be larger than the exhaust volume of the heating section S in which a smaller amount of volatilization occurs from the can body 300. The exhaust volume of the last heating section Sa(m) of the multiple heating sections Sa of the first heating section 10 may be larger than the exhaust volume of the first heating section Sa(1) of the multiple heating sections Sa of the first heating section 10. In addition, the exhaust volume of the first heating section Sb(1) of the multiple heating sections Sb of the second heating section 20 may be larger than the exhaust volume of the last heating section Sb(n) of the multiple heating sections Sb of the second heating section 20.

[0070] The heating device 100 of this example can improve energy efficiency by circulating the hot air that has heated the can body 300 using the circulation path 60. The heating device 100 may select whether or not to provide an exhaust unit 50 depending on the concentration of volatile components in each heating section S, and may adjust the exhaust volume of the exhaust unit 50 depending on the concentration of volatile components in each heating section S. The heating device 100 may omit the exhaust unit 50 or reduce the exhaust volume in heating sections S where the temperature of the can body 300 is relatively low, such as the first heating section Sa(1) of the first heating section 10. The heating device 100 can improve energy efficiency by adjusting the exhaust volume for each heating section S.

[0071] 4B shows an example of a cross section of the heating device 100. The heating device 100 of this example includes a heating unit 40 and a removal device 70 provided in the circulation path 60 of any heating section S.

[0072] In this example, the circulation path 60 does not exhaust the hot air that has heated the can body 300, but reheats the hot air in the heating unit 40 and circulates it. The circulation path 60 that does not exhaust air, as in this example, may be provided in at least one heating section S among the multiple heating sections S. The circulation path 60 that does not exhaust air may be provided in the heating section Sa of the first heating section 10 or in the heating section Sb of the second heating section 20.

[0073] The removal device 70 removes volatile components from the can body 300. The removal device 70 may be provided in at least one heating section S among the plurality of heating sections S. By providing the removal device 70, it is possible to suppress an increase in the concentration of volatile components even when exhaust is not performed in the circulation path 60. However, the removal device 70 may also be provided in the circulation path 60 in which the exhaust section 50 is provided.

[0074] The heating device 100 may be provided with the removal device 70 in some of the heating sections S among the plurality of heating sections S, or may be provided with the removal device 70 in all of the plurality of heating sections S. The heating device 100 of this example can effectively remove volatile components from the can body 300 while reducing the cost of installing the removal device 70 by preferentially arranging the removal device 70 in the heating section S from which it is most desirable to remove volatile components. For example, the removal device 70 is provided in the first heating section Sb(1) among the plurality of heating sections Sb of the second heating section 20. The removal device 70 may also be provided in the last heating section Sa(m) of the first heating section 10.

[0075] 4C shows an example of a cross section of the heating device 100. The heating device 100 of this example has multiple circulation paths 60 in any heating section S. The heating device 100 of this example has two circulation paths 60, a circulation path 60x and a circulation path 60y.

[0076] At least one heating section S among the plurality of heating sections S may be provided with two or more heating units 40. The heating device 100 of this example heats the can body 300 in the heating section S using hot air from the plurality of heating units 40, including heating unit 40x and heating unit 40y. The heating device 100 may include a plurality of heating units 40 arranged in parallel on the circulation path 60, such as heating unit 40x and heating unit 40y. By using electric heaters as the heating units 40, it becomes easier to arrange a plurality of heating units 40 for a single heating section S.

[0077] The heating unit 40x is provided in the circulation path 60x. The circulation path 60x blows hot air generated by the heating unit 40x to the can body 300 via a supply port 61x, and collects the hot air that has heated the can body 300 via a discharge port 62x.

[0078] The heating unit 40y is provided in the circulation path 60y. The circulation path 60y blows hot air generated by the heating unit 40y to the can body 300 via a supply port 61y, and collects the hot air that has heated the can body 300 via a discharge port 62y.

[0079] The heating device 100 of this example uses multiple heating units 40 for a single heating section S, thereby suppressing temperature unevenness within the heating section S. The heating device 100 may be provided with multiple heating units 40 for each of the multiple heating sections S, or multiple heating units 40 for some of the multiple heating sections S. In FIG. 4C , two exhaust sections 50x, 50y are provided for a single heating section S, but these may be combined into a single exhaust section 50, which may branch off and be connected to the multiple heating units 40x, 40y.

[0080] 5 shows specific examples of the upper plate 91 and the lower plate 92. The upper plate 91 may have a plate portion 191 and an opening 291. The lower plate 92 may have a plate portion 192 and an opening 292.

[0081] Plate portion 191 and plate portion 192 may be plates made of metal such as iron. Opening 291 is provided in plate portion 191 to allow the hot air generated by heating unit 40 to pass through. By providing opening 291 in upper plate 91, the hot air can be blown more uniformly to can body 300. Opening 292 is provided in plate portion 192 to allow the hot air that has heated can body 300 to pass through.

[0082] The conveyor 80 may be a mesh conveyor. By using a mesh conveyor as the conveyor 80, the hot air from the heating unit 40 can circulate more easily. The conveyor 80 may be a resin net with holes in the resin, or a metal mesh. By constructing the conveyor 80 from a material with a low heat capacity, it is possible to reduce the energy loss when the conveyor 80 is cooled outside the heating unit and then heated again in the heating unit. By gluing the seams of the resin net, the step at the seams can be reduced, and the can body 300 can be placed on the seams.

[0083] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0084] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0085] 10...first heating section, 20...second heating section, 30...cooling section, 40...heating unit, 50...exhaust section, 60...circulation path, 61...supply port, 62...discharge port, 70...removal device, 80...conveyor, 91...upper plate, 92...lower plate, 100...heating device, 110...can body production line, 111...can body forming process, 112...pre-printing heating process, 113...printing process, 114...post-printing heating process, 115...neck forming process, 116...packaging process, 191...plate section, 192...plate section, 200...manufacturing system, 291...opening, 292...opening, 300...can body

Claims

1. A heating device for heating a can body with hot air, comprising: a heating unit that generates hot air; a first heating section for heating the can body to a higher temperature with the hot air; and a second heating section for heating the can body that has been heated to a higher temperature, wherein at least one of the first heating section or the second heating section has a plurality of heating sections with different heating conditions for the can body.

2. The heating device according to claim 1, wherein the second heating section heats the heated can body and maintains the body at a predetermined temperature.

3. The heating device according to claim 1, wherein the heating unit is an electric heater for generating the hot air.

4. The heating device according to claim 1, comprising a plurality of heating units which generate the hot air, and each of the plurality of heating sections is provided with at least one of the plurality of heating units.

5. The heating device according to claim 1, wherein at least one of the plurality of heating sections is provided with two or more of the heating units.

6. The heating device according to claim 1, wherein the temperature of at least one heating section of the first heating section is higher than the temperature of the heating section of the second heating section.

7. The heating device according to claim 1, wherein the amount of air supplied from the heating unit in the first heating section is greater than the amount of air supplied from the heating unit in the second heating section.

8. The heating device according to claim 1, further comprising a plurality of exhaust sections provided corresponding to the plurality of heating sections for exhausting the hot air, the plurality of exhaust sections adjusting the exhaust volume for each of the plurality of heating sections in which the plurality of exhaust sections are provided.

9. The heating device according to claim 8, wherein the exhaust volume of the last heating section among the plurality of heating sections of the first heating section is greater than the exhaust volume of the first heating section among the plurality of heating sections of the first heating section.

10. The heating device according to claim 8, wherein the exhaust volume of the first heating section among the plurality of heating sections of the second heating section is greater than the exhaust volume of the last heating section among the plurality of heating sections of the second heating section.

11. A heating device as claimed in any one of claims 1 to 10, wherein each of the multiple heating sections has a circulation path that recovers the hot air that has heated the can body, reheats the hot air in the heating unit, and circulates it.

12. A heating device according to any one of claims 1 to 10, wherein at least one of the plurality of heating sections has a circulation path that reheats the hot air that has heated the can body in the heating unit and circulates the reheated hot air without exhausting the hot air.

13. A heating device according to any one of claims 1 to 10, wherein at least one of the plurality of heating sections has a removal device for removing volatile components from the can body.

14. The heating device according to claim 13, wherein the removal device is provided in a first heating zone of the plurality of heating zones of the second heating section.

15. The heating device according to any one of claims 1 to 10, further comprising a cooling section provided downstream of the second heating section for cooling the can body.

16. A heating device according to any one of claims 1 to 10, wherein at least one heating section of the plurality of heating sections of the first heating section and / or at least one heating section of the second heating section can be assembled separately from other heating sections.

17. A method for manufacturing a can body, comprising: a step of generating hot air for heating a can body; a step of heating the can body to a higher temperature in a first heating section using the hot air; and a step of heating the heated can body in a second heating section, wherein at least one of the first heating section or the second heating section has a plurality of heating sections with different heating conditions for the can body.

18. A method for manufacturing a can body as described in claim 17, further comprising a step of forming the can body from a metal plate coated with resin, and the first heating section and the second heating section heat the resin-coated can in which the can body is coated with resin.

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