JPH09192568A - Apparatus for supplying coating material to die coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to gather fine foams in a coating material together at one place and easily discharge the foams to the outside of a pipeline in order to prevent the accuracy in the coating thickness from lowering due to the pressure fluctuation in the pipeline between a pump and a die coater as a cause. SOLUTION: In a coating material-supplying apparatus 1 in which a coating material tank 2 and a die coater 3 are connected through a pipeline 5 and which supplies a coating material stored in the coating material tank 2 to the die coater 3 by a pump 7 installed in the middle of the pipeline 5, an accumulator 4 to gather foams in the coating material and discharge gas from discharging outlets 10, 11 capable of being closed or opened freely, and formed in the upper part is installed in the middle of the pipeline between the pump 7 and the die coater 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint supply device for a die coater, in which a paint tank and a die coater are connected by a pipe, and a paint provided in the paint tank is supplied to the die coater by a pump provided in the middle of the pipe.

[0002]

2. Description of the Related Art Conventionally, as a paint supply device for a die coater, the one shown in FIG. 7 has been generally used. In the paint supply device 30, the paint tank 2 containing the paint and the die coater 3 are connected by a pipe 5, a pump 7 and a filter 8 are provided in the middle of the pipe 5, and the pump 7 pumps the paint in the paint tank 2 to the die coater. It is applied to a base material W such as a glass substrate which is supplied to No. 3 and conveyed in the direction of arrow a with a constant coating film thickness.

When a gear pump or a volute pump is used as the pump 7, the paint sent out from the discharge side thereof contains a large number of fine bubbles having a diameter of about 0.1 mm, but if the inner diameter of the pipe 5 is about 5 mm. Even if the coating material is supplied to the die coater 3, it does not affect the accuracy of the coating film thickness.

[0004]

However, as shown in FIG. 8, in the pipe at a position relatively high due to the bending of the pipe, the minute bubbles 12 gather to form a large bubble 13 having a diameter of 1 mm or more. There is. The large bubbles 13 contract due to the supply pressure of the coating material, and are repeatedly deformed by the reaction to expand, and the vibration thereof causes pulsation in the pipe.
When the inner diameter of the pipe is as small as about 5 mm, the pressure inside the manifold of the die coater 3 fluctuates due to this pulsation, so that there is a problem that the accuracy of the coating film thickness decreases. Especially,
In a thin film coating having a coating film thickness of 10 μm or less, the pressure fluctuation becomes a serious problem when performing precision coating with a coating film thickness accuracy of ± 5% or less in a wet state.

Therefore, in order to solve such a problem, the present invention provides a coating material supply device for a die coater which collects minute bubbles generated in the coating material in a pipe at one place and easily discharges them out of the pipe. To aim.

[0006]

In order to achieve the above object, the present invention connects a paint tank and a die coater with a pipe, and supplies a paint contained in the paint tank to the die coater by a pump provided in the pipe. In the coating material supply device for a die coater, an accumulator for collecting bubbles in the coating material and discharging it from an openable / closable gas outlet formed in the upper portion is provided in the middle of the pipe between the pump and the die coater.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, in a paint supply device 1 for a die coater according to the present invention, a paint tank 2 and a die coater 3 are connected by a paint supply pipe 5 composed of a first pipe 51 and a second pipe 52. .
The first pipe 51 and the second pipe 52 are in communication with each other via the accumulator 4. The first pipe 51 is provided with a pump 7 and a filter 8 from the paint tank 2 side,
An opening / closing valve 9 is provided in the second pipe 52 near the die coater 3.

As shown in FIG. 2, the accumulator 4
Has a substantially conical shape, and a gas discharge port 10 is formed on the upper part thereof. The gas outlet 10 can be opened and closed by a manual or electromagnetic on-off valve 11. Further, in order to sufficiently mitigate the influence of the pressure fluctuation due to the contraction of the large bubbles accumulated in the gas discharge port 10, the accumulator 4
Is formed so that the volume of paint contained therein is sufficiently larger than the volume of the large bubbles. Further, the first pipe 51 extends near the upper end inside the accumulator 4, and the one second pipe 52 is connected to the bottom of the accumulator 4. With this piping structure, the micro bubbles 12 contained in the paint flowing from the first pipe 51 are easily accumulated in the gas outlet 10, and the paint containing the micro bubbles 12 is not sent to the second pipe 52. I am trying.

The shape of the accumulator 4 is not limited to the conical shape, but it is preferable that the cross-sectional area is small in the upper part so that the bubbles in the paint can be reliably collected in the gas discharge port 10. Further, the structure for connecting the pipe to the accumulator 4 may be any part that achieves the action of collecting bubbles. For example, as shown in FIG. 3, the first pipe 51 is connected to the accumulator 4
The second pipe 52 may be connected to the upper side surface of the lower side surface.

The position of the accumulator 4 is such that the pipe between the pump and the die coater has a bent portion when the accumulator 4 is not provided, and when the pipe extends upward from the pump or when the pipe extends laterally from the pump. When first bent upward, it is preferable to arrange the pipe next to or near the bent portion where the pipe bends horizontally or downward, and vice versa. When bending, it is preferable to arrange the accumulator at or near the first bent portion. The reason is that bubbles are most likely to be accumulated in the pipe at such a bent portion or in the vicinity thereof.

The position of the accumulator 4 will be specifically described. The positional relationship between the pump 7 and the die coater 3 is as follows.
Generally, there are three cases where the die coater 3 is at a high position or a low position with respect to the pump 7 when both are at the same height.

When the two are at the same height and are connected to each other by a pipe 5 extending linearly laterally as shown in FIG. 4 (a), the accumulator 4 may be located at any position. As shown in FIG. 4B, when the pipes 5 having a plurality of bent portions are connected for reasons such as avoidance of obstacles, the pipes 5 that extend linearly laterally from the pump 7 first The accumulator 4 is arranged at or near the bent portion 5a where the pipe bends upward and then the pipe bends in the horizontal direction.

The same applies when the die coater 3 is higher than the pump 7, and as shown in FIGS. 5 (a), 5 (b) and 5 (c), the accumulator 4 is provided at or near the bent portion 5a.
Place.

On the other hand, when the die coater 3 is lower than the pump 7, as shown in FIG. 6 (a), the accumulator is formed at the first bent portion 5a where the pipe 5 linearly extending laterally from the pump 7 bends downward. Place 4 In contrast, FIG.
As shown in (b), when the pipe 5 extending from the pump 7 is once bent upward for reasons such as obstacle avoidance, the pipe 5 is bent horizontally as described above. The accumulator 4 is arranged at or near the portion 5a.

In the coating material supply device 1 for a die coater having the above-described structure, as shown in FIGS. 1 and 2, first, the open / close valve 9 is set to the open state, the open / close valve 11 is set to the closed state, and the pump 7 is set. The interior of the first pipe 51, the accumulator 4 and the second pipe 52 is driven to prepare the coating by coating the interior of the first pipe 51, the accumulator 4 and the second pipe 52. Open and close.

Thereafter, the pump 7 is continuously driven to perform the coating work. The paint flowing into the accumulator 4 from the pump 7 through the filter 8 contains micro bubbles 12 as shown in FIG. When the micro bubbles 12 exit the first pipe 51, the micro bubbles 12 float in the coating material due to the buoyancy thereof and gather, and eventually large bubbles 13 are formed at the gas discharge port 10. The large air bubbles 13 are discharged by being pushed out by the paint by periodically opening the open / close valve 11. On the other hand, the paint from which the micro bubbles have been almost removed in this way is sent to the second pipe 52 by the paint supply pressure. At this time, since the accumulator 4 has the effect of reducing the pulsation of the paint flowing in from the first pipe 51 by increasing the volume, the paint is sent out at a more stable pressure. Then, the coating material supplied to the die coater 3 is applied to the base material W.

Although the substrate has been described as the member to be coated, it goes without saying that the member to be coated is not limited to a single plate such as a substrate but may be a strip-shaped member that is continuously coated.

[0018]

As is apparent from the above description, in the coating material supplying device for the die coater according to the present invention, the accumulator can collect the minute bubbles in the coating material at one place and easily discharge them out of the piping. Large bubbles will not accumulate in. In addition, since the volume of large bubbles temporarily formed at the gas outlet is sufficiently smaller than the volume of the paint inside the accumulator, even if the large bubbles contract due to the paint supply pressure, the pressure fluctuation of the paint in the pipe does not change. It hardly happens. Therefore, according to the present invention, the paint can be supplied to the die coater at a stable pressure, the pressure distribution in the manifold of the die coater can be made uniform, and as a result, precise coating can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a die coater paint supply device according to the present invention.

FIG. 2 is an enlarged cross-sectional view of an accumulator used in the die coater paint supply device of FIG.

FIG. 3 is a diagram showing another form of the pipe connection structure to the accumulator.

4A and 4B are views for explaining the position of the accumulator when the pump and the die coater are at the same height.

5 (a), (b) and (c) are views for explaining the position of the accumulator when the die coater is higher than the pump.

6 (a) and 6 (b) are views for explaining the position of the accumulator when the die coater is lower than the pump.

FIG. 7 is a schematic configuration diagram of a conventional die coater paint supply device.

FIG. 8 is a diagram showing a state in which large bubbles are accumulated in the pipe of the bent portion.

[Explanation of symbols]

1 ... Paint supply device, 2 ... Paint tank, 3 ... Die coater,
4 ... Accumulator, 5 ... Piping, 7 ... Pump, 10 ... Gas discharge port, 11 ... Open / close valve.

Claims (1)

[Claims] 1. A paint supply device for a die coater in which a paint tank and a die coater are connected by a pipe, and a paint provided in the paint tank is supplied to the die coater by a pump provided in the middle of the pipe, thereby collecting bubbles in the paint. An apparatus for supplying paint to a die coater, characterized in that an accumulator that discharges from an openable / closable gas discharge port formed in the upper part is provided in the middle of the pipe between the pump and the die coater.