JPH05266A - Coating and / or printing coil metal plate baking apparatus and baking hardening method using the same - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] Excessive printing of paint or / and printing ink applied to the coil metal plate due to replacement of the coil metal plate, etc. (EN) Provided are a baking apparatus and a baking hardening method which prevent baking and prevent insufficient baking hardening. [Structure] A heating furnace 1 has a path 12 through which a coil metal plate 10 passes, and a high-frequency induction heating apparatus 1a is provided facing the path 12.
1b and the constant temperature hot air blowing device 13a in which the blowout ports 14a and 14b are located toward at least a part of the path
13b is provided, and the temperature control device 6 is added to the high frequency induction heating device. The baking method is to introduce the coil metal plate into the heating furnace in which the high-frequency induction heating device is operating and heat it, and when the coil metal plate stops moving, stop the operation of the high-frequency induction heating device and blow a constant temperature hot air. The coil metal plate is heated by the hot air from the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a baking apparatus for continuously drying and baking a coil metal plate used as a material for can making, for example, after coating and / or printing, and the apparatus. Paint on the coil metal plate or /
And a method for baking and curing printing ink.

[0002]

2. Description of the Related Art A long thin plate metal such as iron or aluminum is wound in a coil shape and is used as a so-called coil metal plate as a material for can manufacturing, for example. The coil metal plate set on the uncoiler is conveyed while being unwound by the conveyance drive device and advances, and the surface of the coil metal plate is continuously painted, printed with patterns and letters, and then dried and baked to cure. Then, it is cut into a predetermined size.

Conventionally, a hot air drying oven has been used to continuously heat the coil metal plate during the above-mentioned drying. That is, the coil metal plate that has been painted is heated by passing through a tunnel-type hot air drying furnace whose temperature is maintained within a predetermined temperature range, and the drying and baking of the paint and the like are completed. In heating using this hot air drying oven,
It takes some time for the temperature of the coil metal plate to reach a predetermined temperature because the temperature of the coil metal plate rises after the temperature inside the drying furnace rises due to the hot air and is warmed by the atmosphere. Therefore, it is necessary to pass through the hot air drying furnace for some time. However, slowing down the moving speed of the coil metal plate has its own limit in order to maintain consistency with the moving speed of the coating process. Therefore, the hot-air drying furnace is lengthened to increase the time for passing through the hot-air drying furnace heated to a constant temperature so that the coil metal plate is heated to a predetermined temperature.

On the other hand, as a method for heating a metal plate without using a hot air drying furnace, for example, Japanese Patent Laid-Open No. Sho 62-208591 discloses a high frequency induction heating method. Since this high-frequency induction heating method is a method of heating with an induction current flowing through a metal plate, it is a direct heating, a heating time is short, and it is not necessary to enlarge the heating furnace. It is also an advantage that the peripheral environment other than necessary is not heated.

By the way, as soon as the coating of one coil metal plate is finished, the next one coil metal plate is coated. Usually, the transport driving device is temporarily stopped just before the coating of one coil metal plate is finished, and the rear end part of the coil metal plate is joined to the front end part of the next coil metal plate set in another uncoiler. Then, the transport driving device is operated again. Due to this resetting, at present, the progress of the coil metal plate is stopped for about 1.5 minutes.

[0006]

The heating furnace 1 (see FIG. 1)
In order to heat the coil metal plate 10 which continuously advances by
While detecting the temperature of the coil metal plate 10 by the temperature sensor 2 provided near the outlet of the furnace 1, the temperature of the heat generated from the high-frequency induction heating devices 1a and 1b, which are heat sources, is controlled. In this way, the position measured by the temperature sensor 2 and the position heated by the heat source do not necessarily match. When the coil metal plate 10 is traveling at a substantially constant speed, the actual temperature of the position heated by the heat source and the actual temperature of the position measured by the temperature sensor 2 change in proportion to each other. Accurate control can be obtained by control. However, when the coil metal plate is stopped, the actual temperature of the position heated by the heat source rises, but the actual temperature of the position measured by the temperature sensor 2 does not rise, so that the temperature control is practically not performed. Will end up. If heating is continued without control in this way, overbaking will occur only in the stopped portion in the furnace 1.

In order to prevent such excessive seizure, the transport drive device is operated and stopped, that is, the coil metal plate is advanced,
It is conceivable to operate and stop the high frequency induction heating device according to the stop. However, the coil metal plate has dropped to room temperature or its vicinity during the stop time and has the heating temperature rising time constant (time delay) as the object to be heated, so the operation of the high frequency induction heating device is restarted. However, even if the operation output is maximized by the temperature controller, the temperature does not reach the predetermined temperature immediately. Therefore, the portion of the coil metal plate that has been stopped in the high-frequency induction heating furnace is insufficiently heated, that is, the coating film or the like is insufficiently baked and hardened.

The present invention has been made in view of the above circumstances. Even if the transport driving device is stopped due to replacement of the coil metal plate or due to some circumstances, or the advance of the coil metal plate is stopped due to an accident, the coil metal plate is stopped. When baking paint or / and printing ink applied to a metal plate,
(EN) A baking device that prevents excessive baking and does not cause insufficient baking and hardening, and a baking and hardening method using the baking device.

[0009]

A baking apparatus for painting or / and printing coil metal plate of the present invention, which has been made to achieve the above object, will be described with reference to FIG. 1 corresponding to an embodiment.

As shown in FIG. 1, the printing apparatus of the present invention comprises:
An apparatus for baking paint or (and) printing ink applied to the coil metal plate (10), which has a path (12) through which the coil metal plate (10) passes in the heating furnace (1) and which is opposed to the path (12) and is subjected to high frequency induction heating. The constant temperature hot air blowing devices 13a and 13b, in which the blowing ports 14a and 14b are located toward at least a part of the devices 1a and 1b and the path 12, are provided. A temperature control device 6 is added to the high frequency induction heating devices 1a and 1b.

The bake-hardening method of the present invention made to achieve the above-mentioned object uses the baking apparatus of the present invention. The coil metal plate 10 coated with paint or / and printing ink is Constant temperature hot air blowing device 13a ・ 1
3b and high-frequency induction heating devices 1a and 1b to which a temperature control device 6 is added are introduced into the operating heating furnace 1 to heat the same, and when the coil metal plate 10 stops moving, the high-frequency induction heating devices 1a and 1b operate. And the coil metal plate 10 is heated by the hot air from the constant temperature hot air blowing devices 13a and 13b.

The temperature of the constant temperature hot air to be blown is preferably the lower limit of the cross-linking curing temperature of the paint or printing ink applied to the coil metal plate 10 or slightly higher than that.

[0013]

According to the bake-hardening method of the present invention using the above-described baking apparatus of the present invention, the high frequency induction heating apparatus 1a, 1b and the hot air blowing apparatus 13a.
13b are operating together. High frequency induction heating device 1
While the induction current flows through the coil metal plate 10 by a. 1b and is heated directly, the hot air blowing device 13a, 13b
To some extent indirectly through hot air.
Since the heating rate of the former is much faster than that of the latter, the coil metal plate 10 is heated mainly by high-frequency induction during its progress. When the heating temperature fluctuates due to some disturbance or the like, the operation of the temperature control device 6 controls the high frequency induction heating devices 1a and 1b to keep the temperature constant. While the coil metal plate 10 is stopped, the operations of the high frequency induction heating devices 1a and 1b are stopped, so that excessive baking does not occur. On the other hand, the constant temperature hot air blowing device 13a is also in operation during the stop.
・ Coil metal plate 10 because hot air is continuously blown from 13b
Is heated to a constant temperature. Although hot air heating takes time to heat, since the coil metal plate 10 is stopped, it takes time to heat it to a constant temperature without difficulty.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram showing an embodiment of a printing or / and printing coil metal plate printing apparatus to which the present invention is applied.

Reference numeral 10 in FIG. 1 denotes a painted coil metal plate, which advances in the direction of arrow X at a predetermined speed. Reference numeral 1 denotes a heating furnace, which has a path 12 through which the coil metal plate 10 passes in the central portion. 1a and 1b are coil metal plates 1 in a heating furnace 1.
It is a high-frequency induction heating device comprising induction heating coils arranged in pairs with a 0 path 12 interposed therebetween. 2 is heating furnace 1
A temperature sensor 3 composed of a radiation thermometer provided to face the coil metal plate 10 in the vicinity of the outlet of 3 is a converter for converting a signal from the temperature sensor 2. Reference numeral 4 is a speed measurement sensor for measuring the traveling speed of the coil metal plate 10, and 5 is a converter for converting a signal from the speed measurement sensor 4. 6 receives the signals from the signal converter 3 and the signal converter 5,
This is a temperature controller that controls linear velocity by control (proportional control, integral control, differential control). An analog-digital converter 7 converts an analog signal into a digital signal and vice versa. Reference numeral 8 is a control circuit which receives the digital signal from the analog-digital converter 7 and processes it based on a set program. Reference numeral 9 is a high-frequency oscillator that operates by linear velocity control from the controller 6 that receives the processing signal that is output from the control circuit 8 and that has been analog-converted by the analog-digital converter 7 and that outputs it to the high-frequency induction heating devices 1a and 1b. is there. 13a and 13
Reference numeral b is a hot air blowing device arranged in the heating furnace 1, and blowout ports 14a
14b is located.

The bake-hardening method is carried out by the apparatus of the above embodiment as follows.

The coil metal plate 10 is provided with a path 12 in the direction of arrow X at a predetermined speed from the coating process by a driving means (not shown).
To proceed continuously. Before starting the heating work, the material of the coil metal plate 10, the moving speed of the coil metal plate 10, the temperature of the coil metal plate 10 before heating, the plate thickness of the coil metal plate 10, and the paint used for coating, etc. The heating temperature suitable for the drying temperature is input to the control circuit 8. The control circuit 8 converts these data into parameters for temperature setting. This parameter is converted to analog by the analog-digital converter 7 and input to the PID controller 6 as an initial temperature setting value. Based on the initial setting values, the PID controller 6 instructs the high-frequency oscillator 9 to the proper frequency and current by controlling the linear velocity. The high-frequency oscillator 9 supplies a current to the high-frequency induction heating devices 1a and 1b based on the instruction. An induced current flows through the coil metal plate 10, and after the rising time, the coil metal plate 10 is heated to the initial set temperature. If the temperature of the coil metal plate 10 detected by the temperature sensor 2 deviates from the set temperature due to some reason (for example, the temperature change of the coil metal plate before heating due to the temperature change of the outside air), the high-frequency oscillator is controlled by the PID controller 6. The frequency and current corrected by 9 are passed through the high frequency induction heating devices 1a and 1b. Then, the coil metal plate 10 is corrected to the set temperature.

On the other hand, from the hot air blowing devices 13a and 13b, hot air at a temperature slightly higher than the lower limit of the cross-linking curing temperature is blown out through the blowing ports 14a and 14b all the time. When the coil metal plate 10 is continuously advancing, the temperature sensor 2 detects the temperature obtained by both the heating by the hot air and the heating by the high frequency induction, and the PID controller 6 performs the control operation. A constant temperature can be maintained, and the paint on the coil metal plate 10 is dried and baked and cured.

When the drying and bake-hardening of one coil metal plate is completed in this way, the transport driving device is temporarily stopped for joining with the next coil metal plate.
At this time, the operation of the high frequency induction heating devices 1a and 1b is also stopped. On the other hand, since the hot air is continuously blown from the constant temperature hot air blowing devices 13a and 13b, the coil metal plate 10 is heated to a constant temperature. Although heating with hot air takes a long time to heat, since the coil metal plate 10 is stopped, it takes time to heat it to a constant temperature without difficulty. When the next coil metal plate is set again, the operation of the transport drive device is restarted. At the same time, the operation of the high frequency induction heating devices 1a and 1b is restarted. While the coil metal plate 10 is stopped, the part where the coating material has not been completely hardened by heating with hot air is further hardened by the heating of the high-frequency induction heating devices 1a and 1b as the coil metal plate 10 is restarted, and is then placed in the furnace. Complete the curing of the paint on all parts that were,
Proceeds outside the furnace.

The following experiment was attempted according to the above-mentioned embodiment.

Epoxy paint was applied at 60 mg / dm ^{2 on} a coil aluminum plate having a plate thickness of 0.25 mm, and the paint was dried in an induction heating furnace having a length of 0.4 m at a speed of 30 m / min. From the hot air outlets 14a and 14b, hot air of 140 ° C. was constantly blown out at a speed of about 2 m / sec.
The coil aluminum plate, which advances through the heating furnace 2 at a speed of 30 m / min, has a curing temperature of epoxy-based paint of 1
The coating material is heated to a temperature slightly above 40 ° C., curing of the coating material is completed while proceeding in the heating furnace, the solvent is removed, and a predetermined dry state is obtained. Until the processing of one coil aluminum plate is completed and the next coil aluminum plate is set, the progress of the coil aluminum plate is stopped for about 1.5 minutes, during which the high-frequency induction heating devices 1a and 1b are also operated. Stop. However, the portion of the coil aluminum plate located inside the heating furnace 1 is subsequently heated only by hot air having a temperature near the lower limit of the curing temperature of the coating material to complete the curing. The cured state of the coating film was just enough and good performance was obtained. The coil aluminum plate set next was treated in the same manner to obtain a coating film in a good cured state.

[0023]

As described above in detail, according to the baking apparatus of the present invention and the baking hardening method using the apparatus, the coil metal plate which is continuously advancing is applied to the coil metal plate even when stopped. The coating material and / or the printing ink can be prevented from being excessively baked, and conversely, insufficient baking and curing will not occur. It is possible to obtain a coating film in a very good cured state.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of a baking apparatus for painting or / and printing coil metal plate to which the present invention is applied.

[Explanation of symbols]

1 is a heating furnace, 1a and 1b are high-frequency induction heating devices, 2 is a temperature sensor, 3 is a converter, 4 is a speed measurement sensor, 5 is a converter, 6 is a temperature control device, 7 is an analog-digital converter, 8 Is a control circuit, 9 is a high frequency oscillator, 10 is a coil metal plate, 12 is a coil metal plate passage, and 13a and 13a.
Reference numeral b is a hot air blowing device, and 14a and 14b are outlets thereof.

Claims (2)

[Claims] 1. A paint applied to a coil metal plate or /
And a device for printing printing ink, which has a path through which a coil metal plate passes in a heating furnace, and a high-frequency induction heating device with a temperature control device added to face the path, and at least a part of the path A constant temperature hot air blowing device having a blowout port located toward the front is disposed, and a coil metal plate baking device is characterized. 2. A coil metal plate coated with a paint or / and a printing ink is introduced into a heating furnace in which a high-frequency induction heating device equipped with a constant-temperature hot-air blowing device and a temperature control device is operating, and is heated. A coating material and / or a printing ink on the coil metal plate, characterized in that the operation of the high frequency induction heating device is stopped when the progress of the coil metal plate is stopped, and the coil metal plate is heated by the hot air from the constant temperature hot air blowing device. Bake hardening method.