JP2000262957A - Coating pan for roll coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating pan for a roll coater which is capable of surely discharging the mass of bubbles generated by excess coating material squeezed down between rolls and removing bubbles brought from a coating material feed port in the coating material. SOLUTION: The coating pan for roll coater structured so as to dip a part of a pickup roll 2 in contact while rolling with an applicator roll 3 to scrape the coating material is provided with a coating material storage part 11, in which the pickup roll 2 is dipped, an overflow weir 12, which is formed in the falling down side of the excess coating material squeezed from the pickup roll 2 in the coating material storage part 11 and has lower height than the other part and a partition wall 9, which is for supplying the coating material to the opposite side to the overflow weir 12 across the pickup roll 2 in the coating material storage part 11, in which the upper end exists on the liquid surface and the lower part is opened, between the coating material feed part and the pickup roll dipping part and a coating material recovery part 13 successively provided through the overflow weir 12 is provided in the coating material storage part 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint pan used for a roll coater for continuously coating an object such as a steel strip.

[0002]

2. Description of the Related Art Roll coaters are widely used for continuous coating of objects to be coated such as steel strips. Briefly describing the two-roll coater, as shown in FIG.
By immersing a part of the pickup roll 2 that is rotated and driven in the paint pan 1 in which the paint is stored, the paint is scraped up by the pickup roll 2, and the applicator roll 3 is rolled and contacted with the pickup roll 2.
The paint applied to the applicator roll 3 is applied to the work 4 by applying a paint to the applicator roll 3 and passing a work 4 such as a steel strip between the applicator roll 3 and the backup roll 5. I am trying to transfer it.

The paint is supplied to the paint pan 1 by pumping the paint from a circulation tank 6 by a pump 7 so that the paint overflows at a certain level or more in the paint pan 1 and returns to the circulation tank 6. I have.

Recently, additives such as surfactants are often included in paints for the purpose of improving the leveling property of the coated surface, the stain resistance and the slipperiness. In such a paint, bubbles are easily generated and hardly disappear in a liquid state. Therefore, as shown in FIG. 5, the excess paint is squeezed out at the position where the pickup roll 2 and the applicator roll 3 are in contact with each other, and this drops on the paint liquid surface to generate a large amount of bubbles. Lump A
Is formed.

[0005] In order to suppress the formation of such a lump of air bubbles, Japanese Patent Laid-Open Publication No. Hei 10-180174 discloses an overflow wall in which a paint pan is formed on a paint storage section and on a drop position side of surplus paint to be squeezed and dropped from a pickup roll. It is described that the paint collection section is connected via a, and that a lump of bubbles generated when the paint squeezed out by the applicator roll and the pickup roll dropped into the paint pan after being picked up by the pickup roll is described. Have been.

[0006]

The bubbles are generated when the excess paint squeezed and dropped at the rolling contact position between the pickup roll 2 and the applicator roll 3 falls on the paint liquid surface (bubble A in FIG. 5). In addition, bubbles generated in the circulation tank 6 or the pump 7 are sent to the paint pan 1 or generated when the fed paint falls from the paint supply port to the paint pan 1 (bubble B in FIG. 5). ).

However, Japanese Patent Application Laid-Open No.
No. 74 does not consider bubbles generated in a circulation tank fed from a paint supply port or by a pump, or bubbles generated by falling of paint from a supply port.

In the case where the paint contains a high specific gravity such as aggregate or aluminum powder, when the paint flows from the paint storage section to the paint collection section beyond the overflow wall, the heavy specific gravity is located just before the overflow wall. The additive sinks and stays, and in the case of long-time coating with the same paint, there is also a problem that the color tone and the appearance are changed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and, of course, reliably discharges a lump of air bubbles generated by excess paint squeezed between rolls. It is another object of the present invention to provide a paint pan for a roll coater capable of removing air bubbles in paint brought in from a paint supply port. Also, the present invention
It is an object of the present invention to provide a paint pan for a roll coater in which a change in color tone and appearance with the passage of time in a painting operation is small.

[0010]

Means of the present invention for achieving the above object are as follows.

According to a first aspect of the present invention, there is provided a paint pan of a roll coater in which a part of a pick-up roll contacting with an applicator roll is immersed in a stored paint so that the paint can be scraped up. And an overflow wall having a height lower than the other portion formed on the fall position side of the excess paint squeezed and dropped from the pickup roll of the paint storage section, and the overflow weir sandwiching the pickup roll of the paint storage section. The paint is supplied to the opposite side, and a partition wall having an upper end above the liquid level and a lower part opened between the paint supply section and the pickup roll dipping section is provided, and the paint storage section is provided through the overflow wall. A paint roll for a two-roll coater, comprising a paint collection part connected to the paint roll.

In a second aspect of the present invention, the pickup roll is dipped in a paint pan of a roll coater in which a part of a pick-up roll which is in contact with a militoring roll and an applicator roll is dipped into a stored paint so that the paint can be scraped up. A paint storage section, an overflow wall having a height lower than that of another part formed on the drop position side of the excess paint to be squeezed from the pick-up roll of the paint storage section by a milling roll, and the pickup roll of the paint storage section And a partition wall having an upper end above the liquid surface and a lower end opened between the paint supply section and the pickup roll dipping section, and the paint storage section. A paint collecting section connected to the section via the overflow wall. Is a paint pan over.

According to a third aspect of the present invention, there is provided the paint pan for a roll coater according to the first or second aspect, wherein the bottom surface of the paint storage portion is smoothly raised toward the upper edge of the overflow wall.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a roll coater device (two rolls) to which the present invention is applied, and FIG. 2 is a diagram showing a paint pan arranged in the roll coater device of FIG.

The roll coater apparatus includes a paint pan 1 for a roll coater according to the present invention and a pickup roll 2 partially immersed in the paint pan 1 for the roll coater.
An applicator roll 3 that rolls in contact with the pick-up roll 2 at the upper portion of the paint discharge port; a backup roll 5 that rolls in through an object 4 such as a steel strip that is continuously supplied to the applicator roll 3; The paint tank 1 is provided with a circulation tank 6 for collecting and storing the paint overflowed in the coater paint pan 1, and a pump 7 for pressure-feeding the paint in the circulation tank 6 to the roll coater paint pan 1.

The paint pan 1 for a roll coater includes front and rear side walls 10a and 10b facing each other at a predetermined interval, left and right side walls 10c and 10d connected to the front and rear side walls, and the side wall 1a.
A paint storage portion 11 formed in a rectangular box shape with a bottom plate 10e for closing the bottoms of 0a to 10d, and a left and right side wall 10c, 10d on the paint supply side formed in parallel with the front and rear side walls 10a, 10b. A partition weir 9 that is on the liquid surface and has a lower part that is open, that is, a lower part, that connects the paint supply unit and the pickup roll 2 immersion part, and a side on which the paint that is squeezed by the pickup roll 2 and the applicator roll 3 of the paint storage unit 11 falls. Between the left and right side walls 10c, 10d
An overflow wall 12 formed in parallel with 0b and having a lower height than the other portion;
And a paint collection unit 13 which is continuously provided through the nip.
A paint outlet 14 is formed at an appropriate position on the bottom of the paint reservoir 11.

In the paint pan 1 for a roll coater having the above-described configuration, the pickup roll is extended in the left-right direction at a substantially central portion of a region sandwiched between the partition wall 9 and the overflow wall 12 of the paint reservoir 11. 2 is immersed in the paint, and the overflow wall 12
Is located at a position where a surplus paint dropped by the pickup roll 2 and the applicator roll 3 falls.

A paint supply pipe 21 communicating with the discharge side of the pump 7 is provided in a region sandwiched between the side wall 10b and the partition weir 9.
The discharge end is connected to be lower than the paint liquid level, and the paint return port 17 of the paint recovery unit 13 is disposed at a position lower than the paint pan 1 for the roll coater via the paint discharge pipe 22. The paint outlet 14 of the paint reservoir 11 is connected to the paint discharge pipe 22 via a paint discharge pipe 24 having an opening / closing valve 23 inserted in the middle thereof.

The rotating direction of the pick-up roll 2 and the applicator roll 3 and the conveying direction of the object 4 are such that the pick-up roll 2 is driven to rotate clockwise in FIG. 1 and the applicator roll 3 is driven to rotate counterclockwise. A so-called reverse coater system in which the object 4 is conveyed in a direction opposite to the rotation direction of the applicator roll 3 is employed.

Next, the operation of the above embodiment will be described.
First, the opening / closing valve 23 is closed, and the paint discharge port 14 in the paint storage unit 11 of the paint pan 1 for roll coater is closed. In this state, the paint stored in the circulation tank 6 is pumped by the pump 7. A predetermined amount of paint is supplied to the paint storage unit 11 of the bread 1, and the paint supplied to the paint storage unit 11 constantly overflows the overflow wall 12 to collect a predetermined amount of paint in the paint collection unit 13. The coating liquid level of the section 11 is maintained at a constant value.

In this state, the pickup roll 2 and the applicator roll 3 are driven to rotate in the clockwise and counterclockwise directions in FIG. 1, respectively, and the workpiece 4 is moved in the direction opposite to the rotation direction of the applicator roll 3. By being conveyed, the paint is scraped up by the pickup roll 2, which is sequentially applied to the applicator roll 3, and the paint on the applicator roll 3 is continuously transferred to the work 4.

At this time, since the reverse coater method is employed, the uniformity of the coating film can be improved and a beautiful coating film can be obtained. During this continuous coating, the excess paint scraped up by the pick-up roll 2 is squeezed and dropped at the position where the pick-up roll 2 and the applicator roll 3 are brought into contact with each other, and this drops on the coating liquid surface to generate bubbles. However, when the paint contains an additive such as a surfactant, a large amount of air bubbles that are hard to disappear are generated.

However, since a large amount of these bubbles are generated near the liquid surface near the overflow wall 12, they are discharged to the paint collecting section 13 together with the paint overflowing the overflow wall 12. It does not flow to the position where the paint is picked up by the pick-up roll 2, thereby preventing the occurrence of a coating defect due to the generated bubbles. At this time, the rotation direction of the pickup roll 2 is clockwise in FIG. 1 and a liquid flow for sending the paint toward the overflow wall 12 is formed, so that the bubbles can be more reliably discharged.

The paint containing a large amount of air bubbles flowing out of the paint collecting section 13 through the overflow wall 12 returns to the circulation tank 6 from the paint return port 17 through the paint discharge pipe 22.

Further, the air bubbles returned to the circulation tank 6 cannot be completely eliminated in the circulation tank 6 and are returned to the paint storage section 11 again.
About the bubbles generated when being brought into the pump or being supplied to the pump 7 and the paint storage unit 11, most of the bubbles are removed by being retained by the partition weir 9 by floating up on the liquid surface, and The paint containing no air bubbles is supplied to the immersion portion of the pickup roll 2 from the lower communication portion.

When the coating operation is completed, the operation of the pump 7 is stopped, and then the open / close valve 23 is opened, so that all the paint in the paint reservoir 11 can be returned to the circulation tank 6.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment mainly requires a refrigerator, which is particularly required to have a beautiful coating film surface in place of the case where the present invention is applied to the two-roll type roll coater device in the first embodiment. The present invention is applied to a three-roll type roll coater device used when manufacturing a coated steel sheet for household appliances such as an outer panel of a washing machine or a washing machine.

In the second embodiment, as shown in FIG. 3, the arrangement of the overflow wall 12 and the partition weir 9 of the paint pan 1 for a roll coater is different from that of the paint pan 1 for a roll coater shown in FIG. Left and right are arranged in opposite directions, and a mitering roll 8 is additionally provided. In this apparatus, a pickup roll 2 dipped in a paint pan 1 for a roll coater is used.
Is changed in the counterclockwise direction, and a surplus of the paint scraped up by the pickup roll 2 is squeezed and dropped by a milling roll 8 which comes into contact with an upper portion of the pickup roll 2 on the paint outlet side. Except that the excess paint squeezed out by the roll 8 is allowed to fall near the overflow wall 12, it has the same configuration as that of FIG. 1 described above, and the same reference numerals as those in FIG. 1 denote the same parts. The detailed description is omitted.

In the second embodiment, too, the excess paint squeezed by the milling roll 8 falls near the overflow wall 12 to generate a large amount of air bubbles. The paint is reliably discharged to the paint collecting section 13 together with the paint overflowing the overflow wall 12. Even if these bubbles are circulated again from the circulation tank 6 to the paint storage section 11, most of the bubbles are removed by the partition weir 9 and a more beautiful coating film can be formed.

In the paint pan 1 for a roll coater used in the apparatus shown in FIGS.
1 has an overflow wall 12 as shown in FIG.
Is desirably raised smoothly in the shape of a broken line or an arc toward the upper edge.

Recently used paints may contain aluminum powder or aggregate for the purpose of improving the surface design or abrasion. Since the above additive, which has a higher specific gravity than the paint, sinks with time, the overflow wall 12
Is disposed upright with respect to the bottom of the paint storage section, the additive is accumulated at the intersection of the paint storage section 11 and the overflow wall 12. With the structure as shown in FIG. 4, additives having a high specific gravity do not accumulate in front of the overflow wall 12, and it is possible to minimize a change in metallic feeling, color tone, or appearance over time with coating. .

In each of the above embodiments, the case where the state of communication with the circulation tank 6 is switched by opening and closing the paint discharge port 14 of the paint storage unit 11 with the open / close valve 23 has been described. However, the opening / closing valve 23 may be omitted, and the paint discharge port 14 may be opened / closed with a simple rubber stopper or the like instead. Further, in each of the above-described embodiments, the case where the present invention is applied to the roll coater device using the backup roll 5 has been described. However, the present invention is not limited to this. The present invention can also be applied to an offset coating apparatus using the same.

[0033]

As described above, according to the present invention, 2
In the roll or three-roll coating method, it is possible to remove bubbles generated by dropping excess paint squeezed between the rolls and to remove bubbles supplied to the paint pan, thereby forming a beautiful coating film.

Further, even in a coating system containing an additive such as aluminum powder or aggregate, a coating film with little change in color tone and appearance with time can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a case where a paint pan for a roll coater according to an embodiment of the present invention is applied to a two-roll type roll coater device.

FIG. 2 is a perspective view showing a paint pan for a roll coater according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a case where a paint pan for a roll coater according to an embodiment of the present invention is applied to a three-roll type roll coater device.

FIG. 4 is a perspective view showing a paint pan for a roll coater according to another embodiment of the present invention.

FIG. 5 is a schematic view showing an example of a conventional roll coater device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paint pan for roll coater 2 pickup roll 3 applicator roll 4 object to be coated 5 backup roll 6 circulation tank 7 pump 8 militaring roll 9 partition weir 11 paint storage unit 12 overflow weir 13 paint recovery unit 14 paint outlet 17 paint outlet

Claims (3)

[Claims] 1. A paint pan of a roll coater in which a part of a pick-up roll contacting with an applicator roll is immersed in a stored paint so that the paint can be scraped up. An overflow wall having a lower height than the other portion formed on the drop position side of the excess paint squeezed and dropped from the pickup roll of the paint storage section, on the opposite side of the overflow weir across the pickup roll of the paint storage section. A paint is supplied, and between the paint supply unit and the pick-up roll dipping unit, a partition wall having an upper end on a liquid surface and a lower part opened is provided, and is connected to the paint storage unit via the overflow wall. A paint roll for a two-roll coater, comprising a paint recovery unit. 2. A paint pan of a roll coater in which a part of a pick-up roll which is in contact with a milling roll and an applicator roll is immersed in a stored paint so that the paint can be scraped up. Part, an overflow wall having a height lower than the other part formed on the drop position side of the excess paint squeezed by the milling roll from the pickup roll of the paint storage part, and the pickup roll of the paint storage part sandwiched therebetween. The overflow weir supplies the paint to the opposite side, and has a partition wall whose upper end is above the liquid surface and whose lower part is open between the paint supply unit and the pickup roll dipping unit, and the paint storage unit has the above-mentioned partition wall. A paint roll for a three-roll coater, comprising a paint collection part connected via an overflow wall. N. 3. The paint pan for a roll coater according to claim 1, wherein a bottom surface of the paint storage portion is smoothly raised toward an upper edge of the overflow wall.