JPH07116588A - Coating method by roller curtain coater - Google Patents

Abstract

PURPOSE:To minimize the defective coating on starting coating and on finishing coating and to improve the yield of products by adjusting the timing of starting and finishing of leveling according to the position of a thick film part of a material to be coated. CONSTITUTION:A coating material receiving pan 3 is retreated on starting coating to change a coating curtain 7 from a cutoff state to a falling state. At this time, since there is the lag time between the coating material receiving pan 3 starting to retreat and a coating material in the shape of a thick film falling actually onto a material to be coated 6, the pan is synchronized with the transfer velocity of the material to be coated 6 by a controller 31 and a shutter 21 is retreated when the material is moved by a prescribed distance. After that, a leveling roll 11 is lowered to bring it into contact with the material to be coated 6. On finishing coating, since there is the lag time between the coating receiving pan 3 starting to advance and a coating material in the shape of a thick film finishing falling actually onto the material to be coated 6, the pan is synchronized with the transfer velocity of the material to be coated 6 and the leveling roll 11 is raised when the material is moved by a prescribed distance. After that, the shutter 21 is advanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating a roller curtain coater having a leveling device for thinly averaging the thick film portion of a belt-shaped object to be coated.

[0002]

2. Description of the Related Art FIG. 4 shows an outline of equipment of a roller curtain coater apparatus according to a conventional roll leveling method. In FIG. 4, the paint stored between the coating roll 1a and the doctor roll 1b is discharged downward along the surface of the coating roll 1a from the gap between the coating roll 1a and the doctor roll 1b by the rotation of the coating roll 1a. . The discharged coating material is scraped off from the surface of the coating roll 1a by the blade 2 to form a coating material curtain 7 and is flown down, so that the coating material curtain 7 freely falls from above the steel plate which is the traveling object 6 to be coated. Then, the surface of the steel sheet is painted. A paint receiving pan 3 having a paint receiving pan forward / backward moving mechanism 4 is arranged between the blade 2 and a steel plate which is the object to be coated 6. Further, a roll leveling device is arranged in the traveling direction of the article to be coated 6. The roll leveling device includes a leveling roll driving device including a leveling roll 11 and a leveling roll elevating mechanism 12, and a coating leveling prevention device 11 for preventing paint from falling from the leveling roll 11 including a shutter 21 and a shutter forward / backward moving mechanism 22. It is composed of devices. Before coating is started, that is, while the paint curtain 7 is shut off, the paint curtain 7 is received by the paint receiving pan 3 advanced by the paint receiving pan forward / backward moving mechanism 4, and the paint in the paint receiving pan 3 is The paint is discharged from the lower part of the pan 3 by being connected to the paint discharge port 5,
It is designed so as not to fall onto the article 6 to be coated. Further, the leveling roll 11 is retracted to the upper portion by the leveling roll elevating mechanism 12, and a shutter 21 is advanced between the leveling roll 11 and the object 6 by a shutter forward / backward moving mechanism 22. The paint that has adhered to the leveling roll 11 is prevented from falling onto the article 6 to be coated. When the coating is started, the paint receiving pan 3 is moved backward (moved in the opposite direction of the paint curtain 7) using the paint receiving pan forward / backward moving mechanism 4 to change the paint curtain 7 from the shut-off state to the flow-down state. At this time, the tip of the paint receiving pan 3 (paint curtain 7
Side) drags the paint curtain 7, and when the viscosity of the paint is low, the paint curtain 7 is torn off from the center of the dragged portion and falls in a thick film state. Further, with a highly viscous coating material, the coating material curtain 7 is further dragged, and the coating material in the thick film state separated from the tip of the coating material receiving pan 3 falls on the object 6 to be coated to form the thick film portion 9. Before the thick film portion 9 reaches the position of the leveling roll 11, the shutter 21 is retracted by the shutter forward / backward moving mechanism 22, the leveling roll 11 is lowered by the leveling roll elevating mechanism 12, and the object to be coated 6 Is in contact with. When the thick film portion 9 reaches the leveling roll 11,
After being leveled between the leveling roll 11 and the object 6 to be coated, an armpit is generated by drying / baking in an oven, or a thin film is averaged to a film thickness that does not cause unbaking, and then the leveling roll 11 comes out. Go. After that, the leveling roll 11 is moved upward by the leveling roll elevating mechanism 12 and retracted, and the shutter 2 is provided between the leveling roll 11 and the object to be coated 6.
1 is advanced by the shutter forward / backward moving mechanism 22, and the paint that has adhered to the leveling roll 11 does not fall onto the article 6 to be coated.

[0003]

In the above-mentioned conventional coating method, an operator relies on the operation of the leveling device, and the operation at the start of coating has an unpainted portion before the coating start point. The leveling roll 11 may be lowered to the unpainted part in advance, and the leveling roll 11 may be lifted after the thick film part has passed. At the end of coating, the coating end point can be visually checked in advance. Since it cannot be confirmed, it is necessary to lower the leveling roll 11 to the coating portion and set it in a leveled state earlier. For this reason, the leveling distance of the coating part becomes long, and in reality, there is a large variation in the leveling distance depending on the skill of the operator. Therefore, the product yield is lowered. The present invention has been made to solve the above problems, and in a coating method of a roller curtain coater having a leveling device for thinly averaging the thick film portion of the object to be coated, coating at the start and end of coating. An object of the present invention is to provide a coating method for a roller curtain coater that minimizes defective parts and improves product yield.

[0004]

The present invention advantageously solves the problems of the prior art, and as a result of the inventors' ingenuity to achieve the above object, the start and end of coating By minimizing the leveling distance of the object to be coated at the time, it is possible to minimize the defective coating portion and improve the product yield, which is the gist of the invention.
(1) In a coating method for a roller curtain coater having a leveling device for thinly averaging the thick film portion of the object to be coated, the thick film portion of the object to be coated 6 is leveled at the start and end of coating. The method for coating a roller curtain coater is characterized by adjusting the start and end timings of. Further, at the start and end of coating, the position of the thick film portion of the object to be coated 6 is tracked in synchronization with the moving speed of the object to be coated 6, and the start and end timings of leveling are adjusted. The coating method of the roller curtain coater of 1) may be used. Further, at the start and end of coating, the position of the thick film portion of the coating object 6 is tracked by synchronizing with the moving speed of the coating object 6, and when the thick film portion reaches the measurement position of the coating film thickness measuring device, The coating method for a roller curtain coater according to the above (1) may be characterized in that the film thickness is measured, the necessity of leveling is determined from the coating film thickness, and the start and end timing of leveling are adjusted. .

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation and embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows claims 1 and 2.
2 is an embodiment of the method of the invention. With the start of painting,
The paint pan 3 is used to move the paint pan 3 forward and backward.
The paint curtain 7 is retracted (opposite direction to the paint curtain 7) to change the paint curtain 7 from the shut-off state to the downflow state. At this time, there is a delay time to from the timing at which the paint receiving pan 3 starts to move backward by the paint receiving pan forward / backward mechanism 4 until the paint in the thick film state actually drops on the object 6 to be coated. The distance D1 shown by the following equation from the timing of the backward command of the receiving pan 3 is D1 = LA− (to−t1−t2) · V where L: the distance from the coating start position of the curtain coater to the leveling roll A : Smoothing distance of unpainted part t1: Shutter retreat time (forward limit to backward limit) t2: Falling time of flattening roll (upward limit to lower limit) The control device 31 controls the moving speed V of the workpiece 6. When the object 6 to be coated is synchronized and tracked and moved by D1, the shutter 21 is retracted by the shutter forward / rearward movement mechanism 22, and then lowered by the leveling roll 11 by the leveling roll elevating / lowering mechanism 12 to be coated. Contacting the object 6. Similarly, at the end of painting, the paint pan pan forward / backward movement mechanism 4
Since there is a delay time tc from the timing when the paint receiving pan 3 starts to move forward until the paint in the thick film state actually drops onto the object 6, the following formula is calculated from the timing of the forward command of the paint receiving pan 3 The distance D2 shown is: D2 = LB + (tc-t1-t2) * V where B is the leveling distance of the coating section The control unit 31 synchronizes with the moving speed V of the object 6 to be tracked, When the article 6 to be coated moves by D2, the shutter 21 is moved backward by the shutter forward / backward movement mechanism 22, and then the leveling roll 11 is lowered by the leveling roll elevating / lowering mechanism 12 to contact the object 6 to be coated.

FIG. 3 shows a paint receiving pan 3 and a shutter 2 after the start of coating in the method according to the first and second aspects of the invention.
FIG. 3 is an operation diagram of 1 and the leveling roll 11. When the object 6 to be coated moves by D1 from the timing of the backward command of the paint receiving pan 3, the shutter 21 is first retracted, and when the shutter 21 reaches the backward limit, the leveling roll 11 is lowered. This is to prevent the shutter 21 and the leveling roll 11 from colliding. After the object 6 to be coated is moved and leveled by a distance of (A + B), the leveling roll 11 is raised and the shutter 21 is advanced at the limit of the leveling of the leveling roll 11.
This is also to prevent the collision between the shutter 21 and the leveling roll 11. As a result, regardless of the moving speed of the object 6 to be coated, it is possible to always level the object 6 at a constant leveling distance.
2 and the variation of the operation time of the leveling roll elevating mechanism 12 and the tracking accuracy of the thick film portion,
It became possible to set the leveling distance to the minimum.

FIG. 2 shows an embodiment of the method of the invention of claim 3. Depending on the physical properties of the coating material and the thickness of the coating material curtain, the coating film thickness of the thick film portion 9 formed at the start and end of coating may vary by about 20 to 100 μm.
It has been found that if the coating thickness is about 40 μm or less, no line trouble occurs after the oven. Claim 2
In the case of the method of the invention, since the smoothing is always performed at the start and the end of coating, there is a possibility that unnecessary smoothing is performed. Therefore, when the thick film portion 9 reaches the measurement position of the coating film thickness measuring device 32, the coating film thickness measuring device 32 directly
The coating film thickness is measured, and only when the coating film thickness of the thick film portion 9 is equal to or more than the coating film thickness which causes line trouble after the oven, the thick film portion 9 is thinned and averaged. As a result, it is possible to eliminate unnecessary leveling when the coating thickness of the thick film portion 9 is equal to or less than the coating thickness that does not cause line trouble after the oven, and it is possible to further improve the product yield.

Although the embodiment described above is the case of the roll leveling method, the present invention can be similarly applied to the blade leveling method.

[0009]

As described above, according to the present invention,
In a roller curtain coater having a leveling device, by minimizing the leveling distance of the object to be coated 6 at the start and end of coating, it is possible to minimize defective coating and contribute to improving product yield, You can get great results.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional side view showing an outline of a roller curtain coater device for tracking a thick film portion of an object to be coated according to the present invention.

FIG. 2 is a partial vertical cross-sectional side view showing an outline of a roller curtain coater device for tracking a thick film portion of an object to be coated and measuring a coating film thickness according to the present invention.

FIG. 3 is an operation diagram of a paint receiving pan, a shutter, and a leveling roll after the start of coating by tracking the thick film portion of the object to be coated in the present invention.

FIG. 4 is a partially longitudinal side view showing an outline of a roller curtain coater device according to a conventional roll leveling method.

[Explanation of symbols]

 1a Coating roll 1b Doctor roll 2 Blade 3 Paint receiving pan 4 Paint receiving pan forward / backward movement mechanism 5 Paint receiving pan Paint discharge port 7 Painted object 7 Paint curtain 8 Paint reservoir 9 Paint thick film part 11 Leveling roll 12 Leveling roll lifting Mechanism 21 Shutter 22 Shutter forward / backward mechanism 31 Control device 32 Coating film thickness measuring instrument

Claims (3)

[Claims] 1. A method for coating a roller curtain coater having a leveling device for thinly averaging the thick film portion of an object to be coated, in accordance with the position of the thick film portion of the object to be coated 6 at the start and end of coating. A method for coating a roller curtain coater, characterized by adjusting the start and end timings of leveling. 2. At the start and end of coating, the position of the thick film portion of the object to be coated 6 is tracked in synchronization with the moving speed of the object to be coated 6, and the start and end timings of leveling are adjusted. The method for coating a roller curtain coater according to claim 1. 3. At the start and end of coating, the position of the thick film portion of the coating object 6 is tracked in synchronization with the moving speed of the coating object 6, and the thick film portion reaches the measurement position of the coating film thickness measuring device. The coating method for a roller curtain coater according to claim 1, wherein the coating film thickness is measured at that time, the necessity of leveling is determined from the film thickness, and the start and end timings of leveling are adjusted.