JPH05212333A - Painting apparatus of painted steel plate - Google Patents

Abstract

PURPOSE:To produce a painted steel plate of high quality by sufficiently stirring the painting solution on a roll coater regarless of the kind of paint by providing a direct-acting stirring device in the pan tray of the roll coater in the axial direction of rolls. CONSTITUTION:A painting apparatus is constituted of a roll coator wherein three rolls of a pickup roll 12, an applicator roll 14 applying paint to a steel plate 1 to be painted and a metering roll 13 are arranged in a pan tray 11. The painting solution supplied from a ciurculating tank 17 flows in one direction to pass under the pickup roll 12 to return to the circulating tank 17 finally through piping 16. At this time, the painting solution approaching the lower part of the pickup roll 12 in a direct-acting stirring device 30 is stirred by the stirring rod provided to the leading end of the stirring device 30 so as to generate flows in both directions and, therefore, stagnation causing coating irregularity is eliminated. As a result, the stirred painting solution is transferred to the applicator roll 14 to obtain a painted steel plate free from irregularity.

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] It relates to coating equipment for coated steel sheets.

[0002]

2. Description of the Related Art Painted steel sheets have high demands for resource saving and energy saving such as paint use efficiency, baking energy efficiency, etc., because the user can omit chemical conversion treatment, painting, baking process, etc. ..

FIG. 4 shows a manufacturing process of a general coated steel sheet of this type. An original plate such as a cold-rolled steel plate or a galvanized steel plate is used as a steel plate 1 from an uncoiler 2 through a joining device 3, an accumulator 4, a cleaning device 5, a chemical conversion treatment device 6, a primer coating device 7, and a curing device 8. After curing, the top coater 9 applies the top coat. Then, it is hardened by the hardening device 10, passed through the accumulator 4, and wound up or sheared by the coiler 11 to obtain a coated steel plate product.

A roll coater is generally used as a coating device used in the coating method of the primer coating device 7 and the top coating device 9 in the above steps. As shown in FIG. 5, the roll coater generally transfers the coating liquid with three rolls of a pickup roll 12, a metering roll 13, and an applicator roll 14 in the pan 11 to coat the surface of the steel plate 1.

Generally, the coating liquid is circulated and used by a coating liquid supply device. The return liquid is returned from the return port 11a at the bottom of the pan 11 through the pipe 16 to the circulation tank 17 by the return liquid pump 15b. Then, it is purified from here by the filter 18 and is circulated and supplied as the supply liquid to the pan 11 by the supply liquid pump 15a. In this case, the coating liquid that is insufficient due to painting is in the circulation tank 17,
It is replenished from the replenishment tank 19 by the replenishment liquid pump 15c.

A partition plate 20 is provided on the pan 11 to adjust the flow of the coating liquid. However, in recent years, with the expansion of applications such as cans as coated steel sheets and home appliances, there is a strong demand for improvement in quality performance, which makes the coating composition of resin components, auxiliaries, solvents, etc. complicated, and further Since various additives are used in combination, the coating system tends to be more complicated.

In such a coating system, when used as a coating liquid, a phenomenon in which a specific component in the coating material aggregates, separates, or precipitates with time and is directly coated on a steel plate by a roll coater, It causes various defects.
As an example of measures against such a defect, Japanese Patent Publication No. Sho 62-2158.
No. 2 publication proposes a can body material coating device.

FIG. 6 is a view showing the whole apparatus showing an example thereof, and FIG. 7 is a sectional view of a container equipped with the stirring unit shown in FIG. A supply device 29 for forcibly supplying the coating liquid of the can body material coating material, a roll coater 22 for coating and forming the coating material on the can body material, and a supply device 29 for passing the coating liquid supplied to the roll coater 22. 5-2
The can body material coating device is composed of a stirring unit 23 made of a porous material 24 having through holes having a fine gap of 5μ. The surplus of the coating liquid supplied to the pan 11 is supplied from the receiver 26 to the circulation device 27 by the coating liquid supply tank 28.
Have been sent to. 25 is a coarse plate.

[0009]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 62-2158
The coating device shown in Japanese Patent Publication No. 2 can be expected to have some effects, but has the following problems. Since the stirring unit is installed outside the roll coater, the stirring effect tends to be insufficient with respect to the stagnation of the coating liquid in the pan plate forming the roll coater. Since the agitation unit is made of a porous material having pores with a fine gap of 0.5 to 25 μm, depending on the coating liquid, clogging is likely to occur and pressure loss is generated. However, the running cost will also increase. Since the stirring unit uses a special porous material, it is costly. When the type of coating liquid changes, it is difficult to change to a corresponding porous material each time, so the applicability decreases.

The present invention is intended to solve the above problems, and provides a coating equipment for a coated steel sheet having a simple structure capable of sufficiently agitating the coating liquid of a roll coater regardless of the type of coating material. The purpose is to

[0011]

In order to achieve the above object, the present invention provides a coating liquid circulating and supplying device, and at least two rolls of a pick-up roll and an applicator roll for coating and forming a coating on a base plate to be coated. In the coating equipment of the coated steel sheet consisting of the roll coater installed in
A coating equipment for coated steel sheets is provided in which a direct-acting type stirring device is provided in the coating liquid of the pan in the axial direction of the roll in the vicinity of the lower portion of the pickup roll of the roll coater.

[0012]

According to the present invention, since the linear motion type stirring device as described above is installed in the pan plate of the roll coater, the coating liquid sufficiently stirred in the pan plate of the roll coater is picked up by the pickup roll and the applicator roll. , Transfer coating onto the original plate to be coated. Since a direct-acting type stirring device is used here, stirring can be adjusted depending on the type of coating liquid and the number of strokes of the stirring device.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention.
(A), (b) is a figure which shows the linear-motion type stirring device of the principal part of FIG. 1, (a) is the schematic diagram of the whole, (b) is the AA sectional view of (a). It is a figure which shows the shape of a stirring rod.
In the figure, 30 is a direct-acting type stirring device. The same parts as those in FIG. 5 are represented by the same symbols, and the description thereof will be omitted.

In FIG. 1, the coating equipment of the present invention comprises a circulation supply device as shown in FIG. 5 described above, and a pick-up roll 12, an applicator roll 14, and a metering roll 13 for coating and forming a coating material on the original plate 1 to be coated. In a coating facility consisting of a roll coater 11 in which a roll of a book is installed in a pan pan 11, in the coating liquid of the pan pan 11, a direct-acting type in the axial direction of the pick-up roll 12 is provided close to the lower part of the pick-up roll 12. A stirring device 30 is provided. 21 is a backup roll.

As the original plate to be coated, as described above, a cold rolled steel plate, a zinc plated steel plate or the like is used. If the stagnation occurrence point changes in the direct acting stirring device 30 depending on the flow direction of the coating liquid in the pan, a plurality of direct acting stirring devices 30 may be additionally provided.

In FIG. 2 (a), a direct-acting type agitator 30.
16 stirring rods 33 are provided on the rod-shaped base 31 at intervals.
Is stuck. Both ends of the base 31 are rotatably supported by bearings 32, and one end of the base 31 is connected to a crank mechanism 34 by an air motor so as to be capable of reciprocating linear motion. As shown in FIG. 3B, the stirring bar 33 is used for the base 3
A round bar 33a is fixed to the side of 1, and a stirring plate 33b is attached to the lower part of the round bar 33a. The number and shape of the stirring rods 33 are not limited to this, and can be appropriately selected.

The case of producing a coated steel sheet using the coating equipment of the present invention will be described. The steel sheet 1 is pretreated by the process shown in FIG. 4 and transferred to the roll coater of the top coater. Here, the coating liquid is circulated and supplied to the pan plate 11 from the paint circulation supply device including the circulation tank 17 and the like. That is, the coating liquid is supplied from the top of the pan 11 and the coating liquid circulating tank 17 is supplied from the return port 11a at the bottom thereof.
And is purified by the filter 18 and circulated to supply the coating liquid from the upper part of the pan pan 11.

3 (a) and 3 (b) are views showing the flow of the coating liquid in the pan, (a) is a view showing the state of the present invention, and (b) is a view showing the conventional state. Is.

As shown in FIG. 3A, in the present invention, the pan 11 is sufficiently agitated by the direct-acting agitator 30. That is, the coating liquid on the pan 11 has a flow indicated by a one-directional arrow, passes under the pickup roll 12, and finally flows from the return port 11a to the circulation device. In this case, the direct-acting stirrer 30 causes the coating liquid in the vicinity of the lower part of the pickup roll 12 to be sufficiently agitated by the 16 stirring rods of the direct-acting stirrer 30 to generate a flow as indicated by a double-headed arrow. However, there was no stagnation that caused uneven coating. This agitated coating liquid is picked up by the roll 12
Is transferred to the applicator roll 14 and transferred from the applicator roll 14 to the steel strip 1 for coating.

Here, the metering roll 13
The coating is adjusted. The stirring rate is adjusted by the number of strokes of the direct-acting stirring device 30. Here, the stroke is 30 mm, and the number of strokes is set as the stirring speed in the range of 0 to 475 times / minute.

FIG. 3B shows the flow of the coating liquid in the conventional pan 11 which does not use the direct-acting type stirring device 30. Since only the flow indicated by the unidirectional arrow is shown here, the stagnation point was generated at the place surrounded by the dotted line.

Using the coating equipment according to the present invention, the stroke is set to 30 mm and the speed is set to 100 to 100 by an air motor.
When a high-grade precoated steel sheet made of a polyester coating containing beads, containing metal powder, containing a matting agent, etc. was produced at 200 strokes / minute, in all cases there was no coating unevenness due to the roll coater. Although a continuous steel plate has been described in the above embodiment, the same effect can be expected when the steel plate is a cut plate.

[0023]

EFFECTS OF THE INVENTION According to the present invention, coating equipment having a simple structure in which a stirrer is provided in a pan can prevent coating unevenness caused by a roll coater. The required coated steel sheet can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a direct-acting type stirring device of a main part of FIG.

FIG. 3 is a diagram showing a flow state of a coating liquid in a pan according to the present invention.

FIG. 4 is a diagram showing steps of a general coated steel sheet.

FIG. 5 is a diagram showing an example of a roll coater in a conventional coating process.

FIG. 6 is a diagram showing an example of a conventional can body material coating device.

7 is a diagram showing an example of a stirring unit of FIG.

[Explanation of symbols]

 11 Bread Plate 12 Pickup Roll 13 Metering Roll 14 Applicator Roll 16 Piping 17 Circulation Tank 18 Filter 19 Replenishment Tank 20 Partition Plate 21 Backup Roll 30 Direct Acting Stirrer 31 Base 32 Bearing 33 Stirring Bar 34 Crank Mechanism

Claims (1)

[Claims] 1. A coating equipment for a coated steel sheet comprising a coating liquid circulating and supplying device, a roll coater in which at least two rolls of a pick-up roll and an applicator roll for coating and forming a coating on an original plate to be coated are installed in a pan. A coating equipment for coated steel sheet, characterized in that a direct-acting stirring device is provided in the coating liquid of a pan in the axial direction of the roll in the vicinity of the lower part of the roll of the roll coater.