JPH04338261A - Continuous applicator for belt-like material and continuous coating method - Google Patents

Abstract

PURPOSE:To control the coating film thickness of a product with excellent accuracy and exactly and to surely obtain a continuous coating means to a belt-like material obtaining a superior coating film surface quality. CONSTITUTION:In a roll coater controlling the coating film thickness of the product by adjusting a gap between a pickup roll 1 and an applicator roll 2 or a pressurizing force, a knife edge 7 by which the total amount of a coating material 5 passing through between the pickup roll 1 and the applicator roll 2 is transferred is provided while coming into contact with the prescribed pickup roll. Also by using relevant applicator the measured value of the film thickness of the product with a film thickness detector and a set film thickness value are compared with each other and also the gap between the prescribed both rolls or the pressurized force is adjusted based on the relation which is found preliminarily to the gap between the pickup roll and the applicator roll or the pressurizing force and the coating film thickness of the product.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention provides good coating thickness accuracy,
The present invention relates to a continuous coating device and continuous coating method for strip-shaped materials that provide surface quality.

0002

BACKGROUND OF THE INVENTION Conventionally, a roll coater as shown in FIG. 6 has generally been used for continuous coating of strip-shaped materials such as metal strips. That is, this roll coater usually has a pickup roll 1 and an applicator roll 2.
(Generally, an elastic material such as rubber is layered on the surface)
and a backup roll 3, and the strip material is coated in the following steps.

First, the paint 5 contained in the paint pan 4 is lifted by the rotation of the pick-up roll 1 immersed in the paint, forms a layer on its surface, and rotates with it. The paint lifted by the pick-up roll 1 then passes between the applicator roll 2, which has a positive gap or is pressed against the pick-up roll surface. In addition, pick-up roll 1 and application case
The flow rate of the paint passing between the two rolls is
It is controlled by adjusting the gap between the holes or the pressing force.

[0004] Pickup roll 1 and applicator roll
The paint that has passed between the roller 2 and the pickup roller
It is separated into the applicator roll 1 side and the applicator roll 2 side, and a film is formed on the surface of each roll. And the pickup row
The paint film on the pan 1 returns to the paint pan 4 while the applicator
The paint film on the tar roll 2 is transferred onto the surface of the strip-shaped material 6 which is supported by the backup roll 3 and runs. At this time, since the applicator roll 2 is pressed against the strip material 6 and rotates in the opposite direction to the traveling direction of the strip material 6, almost all of the paint on the applicator roll 2 is is transferred to the strip material 6.

However, it has been pointed out that the above-mentioned coating using the roll coater has a problem in that it is difficult to predict the thickness of the product coating and it is extremely difficult to precisely control the coating thickness. In other words, the thickness of the "paint film transferred to the strip material" that becomes the product depends on the thickness of the paint film on the surface of the applicator roll. The lifted paint layer passes between the applicator roll 2 and the pick-up roll 1, and the flow rate is controlled so that it is immediately peeled off between the pick-up roll side and the applicator roll side. Separate into Therefore, it is extremely difficult to accurately predict the thickness of the paint that will be separated and transferred to the applicator roll. On top of that,
The peripheral speed ratio between the pick-up roll 1 and the applicator roll 2 also greatly affects the thickness of the paint transferred to the applicator roll, so it is even more important to accurately control the product coating thickness. It was difficult.

Moreover, when the paint that has passed between the pick-up roll 1 and the applicator roll 2 separates onto the surface of each roll, the paint film surface as shown in FIG. There is also a problem that this disturbance is transferred to the product coating film and deteriorates the quality.

[0007] Based on the above, an object of the present invention is to be able to precisely control the coating film thickness of a product, and to
The objective was to establish a continuous coating method for strip-shaped materials that would provide excellent coating surface quality.

[0008]

[Means for Solving the Problems] Therefore, the inventors of the present invention conducted research from various viewpoints in order to achieve the above object, and as a result, they were able to obtain the following knowledge.

(a) In the continuous coating of strip materials using a roll coater, the major cause of deterioration in the controllability of product film thickness and the quality of the film surface is ``the gap between the pick-up roll and the applicator roll. However, in order to improve the controllability of the product coating thickness and the quality of the coating surface, it is necessary to aim for the separation of the coating layers. It is essential that

(b) In order to prevent the paint passing between the applicator roll and the pickup roll from separating, the pickup roll is provided with a knife edge in contact with its surface, and the knife edge It is effective to prevent the transfer of paint to the pick-up roll side and transfer the entire amount to the applicator roll side, and by taking such measures, the transfer to the applicator roll side is effective. There is no disturbance on the surface of the paint film, and since the entire amount of paint that has passed through the gap between the applicator roll and pickup roll is transferred to the applicator roll, there is no image of the "transferring paint". The quality is gone and the “transferring paint film thickness”
It is also very easy to predict

(c) Furthermore, as mentioned above, a knife edge is provided on the pickup roll so that the entire amount of "paint that has passed between the applicator roll and the pickup roll" is directed toward the applicator roll. When the transition is made, the relationship between the "gap or pressing force between the pick-up roll and the applicator roll" and the "product coating thickness" becomes more regular, and this "pick-up roll and applicator roll" By determining the relationship between the gap or pressing force and the product coating thickness in advance, you can compare the set value of the product coating thickness with the actual value of the product coating thickness during painting and perform the ``pickup roll''. By adjusting the gap or pressing force between the applicator roll and the applicator roll, it is possible to control the product coating thickness with extremely high precision.

The present invention has been made based on the above-mentioned knowledge, etc., and is based on the above-mentioned findings.As shown in FIG. In the roll coater that controls the product coating thickness,
A knife edge 7 for transferring the entire amount of paint 5 passing between the pickup roll 1 and the applicator roll 2 to the applicator roll 2 is disposed in contact with the pickup roll, or is attached to the knife edge 7. In addition, as shown in FIG. 2, a film thickness detector 8 detects the product coating film thickness, and the measured value by the film thickness detector 8 is compared with the set film thickness value to determine whether the pickup roll or applicator roll a gap control section 9 that calculates the adjustment amount of the gap or pressing force between the rolls; and an adjustment that adjusts the gap or pressing force between the pickup roll and the applicator roll based on the signal from the gap control section 9. By attaching the devices 10 and 11 to constitute a continuous coating device for strip material,
Its major feature is that it is able to stably produce coated products with excellent coating thickness accuracy and surface quality.
When continuously coating a strip material with a roll coater,
A knife edge is arranged in contact with the pickup roll to transfer the entire amount of paint passing between the pickup roll and the applicator roll to the applicator roll,
While comparing the set value of the product coating film thickness with the actual value, the pickup roll is determined based on "the relationship between the gap or pressing force between the pickup roll and the applicator roll determined in advance and the product coating thickness". By adjusting the gap or pressing force between the applicator roll and the applicator roll, it is possible to significantly improve the coating thickness accuracy and surface quality of coated products. In the figure, reference numeral 12 indicates a pedestal, 13 and 14 each a roll pedestal, and 15 a pedestal drive cylinder.

[0013]

[Function] Now, in the continuous coating apparatus for strip material according to the present invention, as shown in FIG. 1, the knife edge 7 is disposed in contact with the pickup roll 1 of the roll coater. The paint that has been lifted from the paint pan 4 by the roll 1 and passed through the gap between the pick-up roll 1 and the applicator roll 2 is separated from the pick-up roll 1 surface by the knife edge 7, and almost the entire amount is removed. Move to the applicator roll 2 side.

[0014] Therefore, the flow rate of the "paint that has passed between the two rolls" whose flow rate is regulated by the gap or pressing force between the pick-up roll 1 and the applicator roll 2 is not separated and is regulated. Since the entire amount is transferred to the applicator roll 2 and transferred to the 6 sides of the strip material, unpredictable fluctuations in the coating thickness on the 6 sides of the strip material are prevented as much as possible. The conventional concern that ``disturbances on the paint surface that occur when the paint is separated'' will be transferred and deteriorate the surface quality will also be eliminated.

Moreover, as shown in FIG. 2, the device includes a film thickness detector 8, a gap control section 9, and an adjustment device 10 for adjusting the gap or pressing force between the pickup roll and the applicator roll. 11 is attached, the film thickness is measured by the film thickness detector 8, the signal is sent to the gap control section 9, and the gap control section 9 compares the measured value of the film thickness with the target value. Based on "the relationship between the gap or pressing force between the pickup roll and the applicator roll and the product coating thickness determined in advance", The adjustment amount of "pressure" is calculated, and the adjustment devices 10 and 11 are controlled accordingly to "pick up load".
By adjusting the gap or pressing force between the applicator roll and the applicator roll, it becomes possible to control the product coating thickness with even greater accuracy and precision. To start and finish painting the strip material 6, the pedestal 12 is moved to the pedestal drive cylinder 1.
5 to bring the applicator roll 2 into contact with the strip material 6 or to separate it from it.

[0016] Here, the "relationship (change situation) between the gap or pressing force between the pick-up roll and the applicator roll and the product coating film thickness (coating film thickness on the strip material)" is as follows. can be determined in advance. That is, in a roll coater with the roll arrangement shown in FIG.
What is necessary is to investigate the change in the coating film thickness [t] on the strip material 6 with respect to the gap [δ] between the applicator roll 2 and the applicator roll 2.

[0017]

Note that the results of this investigation usually show a regular relationship as shown in FIG. By quantifying and taking into account the effect of speed on coating thickness, it is possible to obtain a more accurate relationship that is more in line with the actual situation, and it is also possible to accurately achieve the desired product coating thickness by setting operating conditions in advance. become.

By the way, in Japanese Unexamined Patent Application Publication No. 2-9471, a roll coater is described in which a scraper 16 is disposed oppositely on an applicator roll 2 as shown in FIG. This is done by controlling the distance between the scraper 16 and the applicator roll 2 when the thickness of the paint film on the applicator roll 2 varies in the circumferential direction or in the width direction. Although the aim is to make the thickness uniform, in this case, it is necessary to understand the fluctuations in the paint film thickness in detail and make sophisticated adjustments to the scraper, which poses considerable problems as a practical device. I must say that I am.

[0020] The above-mentioned variation in paint film thickness, especially variation in the circumferential direction, is due to the above-mentioned ``paint layer passing between the pick-up roll and the applicator roll forming on the surface of each roll. This is due to the instability of the separating part when separating upwardly.

In contrast, in the device according to the present invention,
By simply placing a knife edge in contact with the pickup roll to transfer the entire amount of paint passing between the pickup roll and the applicator roll to the applicator roll, variations in paint film thickness can be prevented. It completely eliminates the factor called "instability of the paint layer separation part" which is the root cause of deterioration of the surface quality, and it is possible to control the paint film thickness by using JP-A-2-947.
There is no need for complicated and delicate control as in the first publication. Therefore, in the apparatus according to the present invention, the product coating thickness can be determined simply by controlling the amount of paint passing between the applicator roll and the pickup roll. Control is much simpler than the device described in Japanese Patent No. -9471.

[0022]

[Example] When continuously coating a steel strip with resin paint using a continuous coating device as shown in Fig. 2, A)
When knife edge 7 is not installed (case A), B
) When knife edge 7 is installed (case B), C
) When the knife edge 7 was installed and the inter-roll gap was controlled based on the signal from the film thickness detector 8 (Case C), coating tests were conducted under the conditions shown in Table 2. .

(Note) The gap between rolls in case C is a control setting value.

The temporal fluctuations (longitudinal direction fluctuations) in the product coating thickness revealed by the above test are as shown in FIG. As can be seen from FIG. 5, it is clear that according to the present invention, the thickness of the coating film on the steel strip sheet can be easily and precisely controlled.

[Summary of Effects] As explained above, according to the present invention, the product coating thickness can be easily and highly accurately controlled in continuous coating of strip-shaped materials, and an excellent painted surface can be ensured. This brings about extremely useful effects industrially.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a continuous coating apparatus according to the present invention.

FIG. 2 is an explanatory diagram of another example of the continuous coating apparatus according to the present invention.

FIG. 3 is an explanatory diagram regarding how to determine "the relationship between the gap or pressing force between the pick-up roll and the applicator roll and the product coating thickness."

FIG. 4 is a graph showing the "relationship between the gap between the pick-up roll and the applicator roll and the product coating thickness" in the continuous coating apparatus according to the present invention.

FIG. 5 is a graph showing measurement results of product coating film thickness fluctuations in Examples.

FIG. 6 is an explanatory diagram of a conventional roll coater.

FIG. 7 is an explanatory diagram of the state of paint separation during coating with a roll coater.

FIG. 8 is an explanatory diagram of a conventionally proposed roll coater.

[Explanation of symbols]

1 Pickup roll 2 Applicator roll 3 Backup role 4 Paint pan 5 Paint 6　Strip material 7 Knife edge 8 Film thickness detector 9 Gap control section 10 Adjustment device 11 Adjustment device 12 Mount 13 Roll mount 14 Roll mount 15 Mount drive cylinder 16 Scraper

Claims (3)

[Claims] Claim 1: In a roll coater that controls the product coating thickness by adjusting the gap or pressing force between the pickup roll and the applicator roll, 1. A continuous coating device for a strip-shaped material, characterized in that a knife edge is disposed in contact with the pick-up roll for transferring the entire amount of paint passing through the applicator roll to an applicator roll. [Claim 2] A film thickness detector for detecting product coating film thickness;
a gap control unit that compares the measured value by the film thickness detector with a set film thickness value and calculates the amount of adjustment of the gap or pressing force between the pickup roll and the applicator roll; Pickup roll and application based on the signal of
2. The continuous coating apparatus for strip-shaped materials according to claim 1, further comprising an adjusting device for adjusting the gap between the rolls or the pressing force. Claim 3: When continuously coating a strip material with a roll coater, a knife edge is placed in contact with the pick-up roll and passes between the pick-up roll and the applicator roll. While transferring the entire amount of paint to the applicator roll, we compare the set value of the product coating film thickness with the actual value and transfer the ``predetermined pickup roll and applicator roll.
A continuous coating method for a strip-shaped material, characterized by adjusting the gap or pressing force between a pick-up roll and an applicator roll based on the relationship between the gap or pressing force between the rolls and the product coating thickness. .