JPS6232982B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a raw metal plate for cans, which is coated on both the inner and outer surfaces or on one side of a metal plate such as a tin plated steel plate, a chromium-treated steel plate, or an aluminum plate used for cans consisting of various can bodies and can lids. Concerning continuous coating method and device.

This type of conventional coating method for both the inside and outside surfaces of blank metal sheets for cans includes, for example, a feeding step a in which metal sheets are sequentially supplied one by one from a sheet feeder on the x line, as shown in FIG. External painting process (b) in which the outer surface of the supplied metal blank is coated with an external base coat in a coater, dry baking process (c) in which the painted surface is dried and baked in an oven, and the externally painted metal blank is deposited in a bailani. After finishing the external surface painting through the deposition step d, in order to further perform the internal surface painting, the externally painted blank metal plate is transported to the line y by appropriate means, and the inner surface of the metal blank is coated from the sheet feeder hoist to the top surface. A supply step e in which each metal sheet is supplied one by one, an inner surface coating step f in which a coater applies anti-corrosion thermosetting resin paint to the inner surface of the metal blanks that are sequentially supplied, and the coated surface is dried and baked in an oven. The process sequentially goes through a drying and baking process (g), followed by a deposition process (h) in which metal coated plates coated on both the inside and outside are piled up using a pile arch.

Also, in a painting method that repeats the internal painting twice, such as internal surface base painting and internal surface finish painting, a total of two lines are required, one line each for the internal surface base painting process and the internal finishing process, as described above. .

As described above, the conventional coating method for metal can blanks consists of a process of painting both the inside and outside surfaces, or multiple processes for the inside surface, in which the inside surface painting is repeated twice.
Both methods lack continuity in time and space and are independent and separated painting methods in two rows, so the first
As shown in the figure, separate painting lines consisting of sheet coating, coating, coating, and coating are required, and as the equipment becomes larger, the installation space increases.
Problems such as a decline in production efficiency were unavoidable.

The method of the present invention changes from the conventional method of painting, which is independent and separated in time and space over two-line work, to painting consistently and continuously without interruption with continuity in time and space. This is a continuous coating method for metal can blanks.

Next, the method of the present invention will be explained.

As shown in FIG. 2, the first embodiment of the method of the present invention includes a supplying process A in which metal blanks are sequentially fed one by one from a sheet feeder 1 with the outer surface facing upward, and a first step in which metal blanks are sequentially fed with their outer surfaces facing upward. The first coating process B involves applying thermosetting resin paint over the entire exterior surface using coater 2, and then applying high-speed hot air (e.g., temperature 200°C to 400°C, wind speed 20 to 70 m/min).
sec) is circulated in a short bake sheet oven 3 with a total length of 20 m or less, for example, 60~
A semi-baked drying process C in which the metal element is passed through at a speed of 180 m/min and baked to a degree that does not cause damage to the painted surface during transportation in the subsequent process or by a coater, etc.; A reversal step D in which the plate is rotated 180 degrees with a turnwheel 4 so that the inner surface faces upward, and a second coater 5 coats the entire inner surface of the reversed metal plate with a thermosetting resin paint for corrosion protection. A conventional baking oven 6 with a total length of 30 m or more is used to ensure the second painting process E and the complete adhesion of the coating on both the inside and outside of the metal blank.
A main baking drying step F in which baking drying is carried out stably by
The stacking process G in which the coated plates after drying and baking are stacked one by one using a sheet piler 7 is carried out step by step to provide continuity in time.

Furthermore, as shown in FIG. 3, the second embodiment of the method of the present invention includes a supply step A in which the metal blanks are sequentially supplied one by one from the sheet feeder 1, and a first coater is applied to the inner surface of the metal blanks that are sequentially supplied. The first step is to apply a base coat of thermosetting resin paint and treat the inner surface with a base coat.
Next painting process B and high speed hot air (e.g. temperature 200℃~
400℃, wind speed 20-70m/sec) total length of 20m
The metal blank is passed through the following short bake sheet oven 3 at a speed of, for example, 60 to 180 m/min, and baked and dried to the extent that the coated surface will not be damaged during transport or by a coater in the subsequent process. A semi-baking drying step C, and a second painting step E in which a corrosion-resistant thermosetting resin paint is layered and applied on the same inner surface using a second coater 5 to perform an inner surface top coat treatment,
The final baking and drying process F involves stable baking and drying using a conventional baking open 6 with a total length of 30m or more so that the internal coating film applied twice on the metal plate is completely adhered, and after baking and drying, the coated plate is turned into a sheet. The deposition step G in which the layers are piled up one after another by a piler 7 is sequentially and stepwise to provide continuity in time.

As mentioned above, the first embodiment of the method of the present invention is a coating method that covers the inner and outer surfaces, and requires the reversal step D so that the inner and outer surfaces of the metal blank sequentially become upper surfaces, but in the case of the second embodiment, Since the inner surface is coated twice, the reversal step D can be omitted, but the purpose of the method of the present invention is the same.

Therefore, the method of the present invention basically consists of feeding step A, the first
The next painting process B, the semi-baking drying process C, the second painting process E, the main baking drying process F and the deposition process G are carried out step by step, but with continuity in time. There is no problem even if a reversing process D is interposed between the semi-baking drying process C and the second painting process E.

In addition, the method of the present invention uses a short bake sheet oven 3 in which high-speed hot air is circulated after the first coating step B.
By introducing a semi-baking drying process C in which the coated surface is semi-baked and dried to an extent that avoids various problems caused by post-processes, the conventional deposition process d and supply process e shown in Fig. 1 are omitted. This is a continuous coating method for metal can blanks that saves time and provides continuity.

Next, a continuous coating apparatus for metal blanks for cans to which the first embodiment of the method of the present invention is applied will be described.

As shown in FIG. 4, the continuous coating device X of the present invention has a first half line
and the second half line X2 are connected to each other by a turnwheel 4, and the first half line X1 is a sheet feeder 1 that feeds the metal blank α one by one onto the first belt conveyor 8 with the outer surface facing upward. , sequentially 1
Metal blank α being conveyed on belt conveyor 8
The first step is to apply thermosetting resin paint to the outside surface of the
Coater 2 and high-speed hot air (e.g. temperature 200℃~400℃)
℃, wind speed 20 to 70 m/sec),
The high-speed hot air is circulated to the second belt conveyor 9.
A short bake sheet oven 3 is used to semi-bake and dry the coating film of the metal blank α whose outer surface has been painted, which is transported thereon, to the extent that it will not be damaged during transport or by a coater, etc. in the subsequent process. A first belt conveyor 8 is arranged in a row between the sheet feeder 1 and the first coater 2, and a second belt conveyor 9 is provided between the first coater 2 and the turnwheel 4 with a short bake sheet oven 3 interposed therebetween. On the other hand, the first
The belt conveyor 8 and the turnwheel 4, which rotates a blank metal plate α whose outer surface is semi-baked and painted by 180 degrees so that its inner surface is the upper surface, are each driven synchronously by a main motor 10 consisting of a VS motor.

Furthermore, the second half line X2 is reversed by the turn wheel 4, transferred onto the start end of the third belt conveyor 11, and is conveyed by a second coater 5, which applies a thermosetting resin paint for corrosion protection to the inner surface of the metal blank α. A conventional scale with a total length of 30 m or more is used to bake and dry the metal blank α, which is transferred from the second coater 5 to the start end of the fourth belt conveyor 12 and conveyed, so that the coating on both the inside and outside surfaces is completely adhered. A baking oven 6 and a sheet piler 7 for sequentially stacking painted boards after baking and drying are arranged in sequence, and a third belt conveyor 11 is provided between the turnwheel 4 and the second coater 5, and a third belt conveyor 11 is installed between the turnwheel 4 and the second coater 5. a fourth belt conveyor 12 between the baking oven 6 and the baking oven 6; and a fourth belt conveyor 12 between the baking oven 6 and the sheet piler 7;
The main motor 10 and the slave motor 14 are driven by a slave motor 14 consisting of a DC motor, and the main motor 10 and the slave motor 14 can be operated synchronously at the same speed. The first half line X1, the second half line X2 and the turnwheel 4 constituting the drive device SD are constructed in a continuous line so as to be capable of synchronous operation.

The sheet feeder 1 has several suction cups 15 that suck up and feed out the metal blanks α one by one, a rotary pump that generates vacuum, and a rapid lifting device 16 when loading the metal blank α, and Even if the loading amount of the metal blank α decreases due to the feeding of α, the loading top surface is automatically kept constant at all times. Furthermore, both devices include a device for separating loaded metal blanks α from each other using a permanent magnet and a blow nozzle (not shown), and a device for automatically taking out the metal blanks α by preventing two-sheet feeding using a double detector.

The first coater 2 and the second coater 5 are
As shown in FIG. 5, the paint supplied between the distributor roller 17 and the fountain roller 18 is transferred to a coating roller 19 made of glue or synthetic rubber, and a specified amount is applied to the painted surface of the metal blank α. Transferred, applied. The specified amount is adjusted by adjusting the gap between each roller and controlling the viscosity.

In the figure, 20 is a coating pan, 21 is a scraper roller, 22 is a moisture roller,
23 is a scraper blade.

As shown in FIGS. 6 to 8, the short bake sheet oven 3 has a second belt in which the metal blank α coated by the first coater 2 runs in parallel with a plurality of belt gaps. It has a total length of 20 m, with the conveyor 9 in between, straddling the bases 24 and 25 installed on both sides, and having heat-insulating walls with a thickness of 75 to 100 mm.
A hot air supply device 27 is suspended above the bake tunnel 26 below, and a supply fan 28 and a combustion chamber 29 are installed above the bake tunnel 26, while a first duct is installed between the combustion chamber 29 and the supply fan 28. A second duct 31 is provided between the supply fan 28 and the hot air supplier 27 through the ceiling of the bake tunnel 26, and a third duct 31 is provided from the ceiling of the bake tunnel 26 to the combustion chamber 29. 3
2, the heat obtained by the combustor 33 in the combustion chamber 29 is sucked into the supply fan 28 and becomes high-speed hot air β.
From the hot air blowing nozzle openings 34 opened at equal intervals on the lower surface of the hot air supply device 27 and in a direction perpendicular to the running direction of the second belt conveyor 9, the metal blank α being transported on the second belt conveyor 9 is heated. The hot air is blown at a speed of, for example, about 20 to 70 m/sec, and then the hot air is returned to the combustion chamber 29.
Note that there is no problem in opening the hot air blowing nozzle opening 34 in a direction oblique to the traveling direction of the second belt conveyor 9.

In this case, it will be more effective if a hot air supplier (not shown) is provided below the second belt conveyor 9 along with the hot air supplier 27, and the hot air is auxiliary blown from the upward hot air blowing nozzle port 35 as shown in FIG. be.

Note that the high-speed hot air from the short bake sheet oven 3 reaches temperatures of 200°C to 400°C, but if the temperature of the conveyor belt becomes high, cold air is blown onto the return side of the belt from an air cooler (not shown) to cool it. Therefore, it can be used even if the conveyor belt has a heat resistance temperature of 200°C to 300°C.

For example, as shown in FIG. 9, the drive device SD has timing cams 36 and 37 of the same size fixed to the shafts of the main motor 10 and the slave motor 14, respectively, and sensors located close to the timing cams 36 and 37, respectively. 38 and 39 are presently located,
Take out the main detection signal S1 and the sub-detection signal S2,
The signal is input to a comparator 40 composed of an electric circuit and the like. Main/slave detection signal S input to comparator 40
1 and S2 are compared with each other, and a timing correction signal S3 is generated as needed, which is inputted to the controller 41 provided in the slave motor 14 to constantly control the main and slave motors 10,
14, and the first half line X1 and the second half line X
2 and turnwheel 4 are operated synchronously.

Therefore, when adjusting the coating, main motor 1
0 and the slave motor 14 can be operated independently, and as a result, the first half line X1 and the second half line X2 are individually operated and adjusted.
can be operated synchronously.

Incidentally, the timing cams 36 and 37 may be attached to other rotating shafts whose rotational speed is most easily detected and synchronously adjusted.

Thus, the present invention has remarkable effects such as shortening the working time of the painting process and improving production efficiency, and furthermore, reducing equipment costs due to equipment savings and greatly reducing the installation space.

[Brief explanation of the drawing]

Fig. 1 is a process flowchart showing a conventional coating method and a block diagram of the line, Figs. 2 and 3 are process flowcharts showing a block diagram of the coating method and equipment of the present invention, and Fig. 4 is a process flowchart of the present invention. Schematic side view of continuous coating line, fifth
The figure is an explanatory drawing of the coating of the coater, Figure 6 is a schematic configuration diagram of the short bake sheet oven, Figure 7 is an enlarged plan view of the hot air blowing state of the hot air blowing nozzle opening, and Figure 8 is the hot air of the same and other examples. A side view of the blowing state, FIG. 9 is a system diagram of the drive device. A... Supply process, B... Primary painting process, C... Semi-baking drying process, D... Reversing process, E... Secondary painting process, F... Main baking drying process, G... Deposition process, X... Continuous coating device , X1...first half line, X2...second half line, SD...drive device, S1...main detection signal, S
2...Sub detection signal, S3...Timing correction signal, α
...Metal blank, β...High speed hot air, 1...Sheet feeder, 2...First coater, 3...Short baking sheet oven, 4...Turn wheel, 5...Second coater, 6...Baking oven, 7...Sheet piler , 8...First belt conveyor, 9...Second belt conveyor, 10...Main motor, 11...Third belt conveyor, 12...Fourth belt conveyor, 13...Fifth belt conveyor, 14...Slave motor, 26...Bake tunnel , 27... Hot air supply device, 28... Supply fan, 29... Combustion chamber, 30... First duct, 3
1...Second duct, 32...Third duct, 34...Hot air blowing nozzle port, 36, 37...Timing cam, 3
8, 39...Sensor, 40...Comparator, 41...Controller.

Claims (1)

[Claims] 1. A supply step of sequentially supplying metal blanks one by one;
The first painting process involves applying thermosetting resin paint to the metal base plate, and the semi-baking drying process involves passing it through high-speed hot air and baking it to a degree that does not cause damage to the coated surface of the metal base plate in the subsequent process. This book describes the process, the reversing process of reversing the metal base plate, the secondary painting process of applying thermosetting resin paint to the metal base plate, and baking drying so that the coated surface of the metal base plate is completely adhered. A continuous coating method for metal blanks for cans, in which a baking-drying process and a stacking process of sequentially stacking the painted plates after the baking-drying are carried out step by step. 2. A sheet feeder that sequentially supplies metal blanks one by one, a first coater that applies thermosetting resin paint to the metal blank, and a second coater that runs through a bake tunnel.
Hot air blowing nozzle openings are opened in a direction perpendicular or oblique to the conveying direction of the second belt conveyor at equal intervals on the lower surface of the hot air supply device extending directly above the belt conveyor, and a combustion chamber is provided outside the bake tunnel. and the hot air supply device are connected via a supply fan midway through a duct, and appropriate locations on the ceiling of the baking tunnel are connected to the combustion chamber through ducts to generate high-speed hot air, which is blown and circulated to cause damage to the painted surface in the subsequent process. The first half line includes a short bake sheet oven that semi-bakes and dries the metal blank to a degree that does not cause any damage, and a second coater that applies thermosetting resin paint to the metal blank. A conventional baking oven and a second half line, which has a sheet piler that gradually stacks painted boards after baking and drying are interposed in a series of conveyor rows, are connected by a turnwheel that flips the metal blank 180 degrees. . A continuous coating apparatus for metal blanks for cans, comprising a drive device that can operate the first half line and the second half line separately and independently and at the same speed and synchronize with each other.