JPH0734955U - Roll coater type coating equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a roll coater type coating device which has a simple structure and can stably prevent the occurrence of coating defects on the front and back surfaces of a steel strip. [Structure] Applicator rolls 3a and 3b, which are arranged in proximity to pickup rolls 2a and 2b whose lower part is dipped in the paint in paint pans 9a and 9b with a required gap,
In the coating device configured to come into contact with the continuously running steel strip S wound around the backup roll 1, the steel strip S
Immediately after transferring the paint to the applicator roll 3a
Polishing rolls 7a and 7b were provided in contact with the outer peripheral surface of 3b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a roll coater type coating device for applying paint or resin to the front and back surfaces of a continuously running steel strip.

[0002]

[Prior art]

 In recent years, there has been an increasing demand for coated steel sheets that are excellent in rust prevention, lubrication, decoration, etc. for construction or household electric appliances, and roll coater type coating equipment is generally used for continuous coating of steel sheets. There is.

The roll coater type coating apparatus described above is proposed in, for example, Japanese Patent Publication No. 60-56552. As shown in FIG. 2, this coating apparatus winds a backup roll 1 around an applicator roll 3 whose lower portion is located in close proximity to a pickup roll 2 dipped in the paint in a paint pan 9 with a required gap. It is configured so that it touches the hung steel strip S, for example, and backs up the paint in the paint pan 9 attached to the rotating pickup roll 2 via the applicator roll 3 rotating at a constant speed ratio with respect to the pickup roll 2. It is to adhere to the steel strip S wound around the roll 1. In this coating apparatus, the thickness of the coating material adhered to the steel strip S is adjusted by changing the pressing pressure and the rotation speed ratio of the pickup roll 2 and the applicator roll 3.

FIG. 3 shows the coating apparatus disclosed on page 347 of the latest coating technology (enlarged version) (supervised by Yuji Harasaki, General Technology Center). This coating apparatus includes a back-up roll 1, a dual-purpose roll 8 that also functions as a pickup roll and an applicator roll, a doctor roll 5 that adjusts the thickness of the paint that adheres to the dual-use roll 8, and a doctor roll 5 It is provided with a blade 6 for scraping off the paint adhering to, and the paint in the paint pan 9 is adhered to the dual-purpose roll 8 and supplied to the surface of the steel strip S.

In the coating device of Japanese Patent Publication No. 60-56552, the pick-up roll and the applicator roll make so-called natural rotation, that is, both rolls rotate in opposite directions, Since both surfaces are moving in the same direction at the positions where the surfaces meet, cavitation and filamentation occur in the area on the exit side of the roll gap between the two rolls, causing bubbles and threading due to air inclusion. The elephant happens. Then, due to this stringing phenomenon, streak-like unevenness, that is, buildup occurs in the paint adhered to the surface of the applicator roll. Not all of the paint that adhered to the applicator roll surface was transferred to the steel strip, but the remaining paint solidified with streaky unevenness on the applicator roll surface over time, causing streaky unevenness. This will transfer some paint to the surface of the steel strip, causing paint failure.

Further, in the coating device described in the above-mentioned document, the pickup roll and the dual-purpose roll rotate in opposite directions to each other. Streaky unevenness occurs, causing uneven paint transfer to the surface of the steel strip and causing coating failure.

Therefore, Japanese Patent Publication No. 3-76188 proposes a coating device which prevents deterioration of the smoothness of the coating film surface in these coating devices and improves the pick-up property of the coating material.

[0008]

[Problems to be solved by the device]

 As shown in FIG. 4, this coating apparatus includes a transfer roll 4 that is close to the applicator roll 3 with a required gap and a doctor roll 5 that is close to the transfer roll 4 with a required gap. With respect to the rotating direction of the trolls 3, they are arranged on the downstream side of the pick-up rolls 2, respectively, and the doctor rolls 5 are provided with the blades 6 in contact with the blades. The backup rolls 1, the applicator rolls 3, The transfer roll 4 and the doctor roll 5 are all driven to rotate in the same direction, and the pickup roll 2 is driven to rotate in the opposite direction to these rolls.

In this coating apparatus, since each roll rotates in the same direction, unevenness of the coating surface is reduced and it is effective in preventing coating failure. However, on the other hand, increasing the number of rolls complicates the device structure. However, there is a problem that the cost becomes expensive.

When coating the front and back surfaces of a steel strip with a paint or a resin using an S-type roll coater type coating device, the build-up described above is particularly performed with an applicator roll arranged on the back side of the steel strip. There is a problem that the up phenomenon is likely to occur. It is considered that this is because the paint or resin flows to the applicator roll under the influence of gravity.

The present invention has been made in view of the above-mentioned problems, and provides a roll coater type coating device capable of stably preventing coating defects on the front and back surfaces of a steel strip with a simple configuration. That is.

[0012]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the roll coater type coating apparatus of the present invention has an applicator roll which is arranged in the vicinity of a pickup roll whose lower part is immersed in the paint in a paint pan with a required gap. In a coating device configured to come into contact with a continuously running steel strip wound around a backup roll, a roll surface polishing device that comes into contact with the outer peripheral surface of the applicator roll immediately after the paint is transferred to the steel strip is provided. It was.

[0013]

[Action]

 The roll coater type coating device of the present invention has a lower portion of the applicator roll, which is placed in close proximity to the pick-up roll immersed in the paint in the paint pan, with a required gap, and is wound around a backup roll for continuous running. In the coating device configured to come into contact with the steel strip, the roll surface polishing device that comes into contact with the outer peripheral surface of the applicator roll immediately after the paint is transferred to the steel strip is installed, so the outer peripheral surface of the applicator roll is always smooth. To form a smooth surface.

[0014]

【Example】

 Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing the construction of a roll coater type coating apparatus of the present invention.

In the drawings, reference numeral 1 is a backup roll around which a steel strip S to be coated is wound. In order to attach the paint to the surface of the steel strip S wound around the backup roll 1, the backup roll 1 is in contact with the surface of the steel strip S. The applicator roll 3a arranged in the above is closely arranged with the pickup roll 2a whose lower part is immersed in the paint in the paint pan 9a with a required gap. Further, on the downstream side of the backup roll 1, a pickup roll 2b for adhering paint to the back surface of the steel strip S, an applicator roll 3b, and a paint pan 9b are arranged in the same manner as described above. 7a and 7b are, for example, buffing rolls arranged so that the respective applicator rolls 3a and 3b are in contact with the outer peripheral surface immediately after the paint is transferred onto the surface of the steel strip S. The outer peripheral surfaces of the applicator rolls 3a and 3b immediately after the transfer are constantly polished. In addition, 10 is a support roll.

The roll coater type coating apparatus of the present invention is configured as described above, and the paint in the paint pan 9a is attached to the surface of the steel strip S via the pickup roll 2a and the applicator roll 3a. . At this time, the coating material having streaky unevenness due to the build-up phenomenon remains on the outer peripheral surface of the applicator roll 3a, but the polishing roller 7a always removes the remaining coating material and the outer periphery of the applicator roll 3a. Since the surface maintains a smooth surface, it is possible to prevent the transfer of the paint with streaky unevenness to the surface of the steel strip S. Similarly, with respect to the applicator roll 3b arranged on the downstream side of the backup roll 1, it is possible to prevent transfer of the coating material having streaky unevenness to the back surface of the steel strip S.

By the way, a roll coater type coating apparatus under the following conditions was equipped with a polishing roll for buffing with a roll diameter of φ100 mm, and the surface roughness of the applicator roll was constantly polished to 1 μm to obtain a steel plate with a thickness of 1 μm. According to the roll coater type coating apparatus of the present invention shown in FIG. 1 which is adapted to coat the front and back surfaces of the belt, 15% of coating defects occur in the roll coater type coating apparatus shown in FIG. However, it has been reduced to 5%.

The conditions of each part are as follows: pickup roll: roll diameter φ300 mm, rotation speed 50 rpm, applicator roll: roll diameter φ270 mm, rotation speed 160 rpm, backup roll: roll diameter φ1000 mm, peripheral speed line synchronization, pickup roll and applicator The roll gap is 0.4 mm, and the paint is an acrylic resin coating.

[0019]

[Effect of device]

 As described above, the roll coater type coating device of the present invention is always equipped with the roll surface polishing device which is in contact with the outer peripheral surface immediately after the applicator roll has transferred the coating material to the steel strip. Since the paint remaining on the outer peripheral surface of the steel is removed and a smooth surface is maintained, the paint with uneven streaks on the surface of the steel strip does not transfer when the paint with residual unevenness solidifies. It can be prevented. Therefore, a beautiful coated steel sheet can be stably manufactured, and the yield rate of the product is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a roll coater type coating apparatus of the present invention.

FIG. 2 is a diagram showing a configuration of a first conventional roll coater type coating apparatus.

FIG. 3 is a diagram showing a configuration of a second conventional roll coater type coating apparatus.

FIG. 4 is a diagram showing a configuration of a third conventional roll coater type coating apparatus.

[Explanation of symbols]

 1 Backup Roll 2a Pickup Roll 2b Pickup Roll 3a Applicator Roll 3b Applicator Roll 7a Polishing Roll 7b Polishing Roll 9a Paint Pan 9b Paint Pan S Steel Strip

Claims (1)

[Scope of utility model registration request] 1. An applicator roll, the lower part of which is placed in close proximity to a pick-up roll immersed in the paint in a paint pan with a required gap, is brought into contact with a continuously running steel strip wound around a backup roll. A roll coater type coating apparatus, characterized in that, in the coating apparatus configured as described above, a roll surface polishing apparatus that is in contact with the outer peripheral surface of the applicator roll immediately after the coating material is transferred to the steel strip is provided.