JPH0724393A - Method and device for feeding coating material to dye coater - Google Patents

Abstract

PURPOSE:To maintain a suction end pressure of a quantitative pump constant, carry out the dye coating with a high accuracy and obtain an excellent film by complying with the extraction of a coating material out of a coating material container and inclining or lifting the coating container. CONSTITUTION:When a coating material is fed, first a plurality of valves are opened and closed as the prime work, and a feeding pump 6 is operated to circulate the coating material in a coating material container 1 and feed the coating material to a quantitative pump 2. Then the quantitative pump 2 is actuated as the coating work, and the material is fed into a dye coater quantitatively through a filter device 19. In that case, when a coating material liquid level in the coating material container 1 is lowered with the progress of the coating, the lowering is sensed as the back pressure change of the quantitative pump 2 by a pressure gauge 18. An inclination mechanism 15 is so operated as to restore the sensed value of back pressure to the reference value and the material container 1 is moved inclinedly. That is, a container placing bed 16 is made to pivot along a guide rail 17 to move inclinedly the coating material container 1 and compensate the lowering of the coating material liquid level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying paint to a die coater. In particular, the present invention relates to a coating material supply method capable of quantitatively supplying a coating material with high accuracy and preventing bubbles from being generated in the coating material by a pump.

[0002]

2. Description of the Related Art Conventionally, a die coater has been mainly used for thick film coating or high viscosity coating due to restrictions such as die manufacturing accuracy and control technology. The paint supplied to the die coater is usually contained in a simple container such as a drum, and a pipe or hose is inserted from the upper part of the container to pump up the paint. Therefore, as a paint supply device to the die coater, a simple one is mainly used in which a die coater and a paint container are connected by piping, and a supply pump such as a gear pump and a filter are installed in the middle thereof. .

[0003]

Recently, a die coater for precision coating is being developed. However, since the supply of the paint to such a die coater requires high quantitativeness, it is necessary to use a regular gear pump or the like. A conventional paint supply device using a pump having a low property cannot be used. As a solution to this point, a Zenith pump or the like with a low self-priming but highly quantitative pump and a low-quantitative but self-priming supply pump, such as a diaphragm pump, a snake pump, or a gear pump, are used together. There is a paint supply device. An example thereof is shown in FIG. 2, and the suction side supply pipe 3 from the paint container 1 to the suction end of the metering pump 2 installed at a position lower than the paint liquid level of the paint container 1 and the discharge of the metering pump 2 Discharge side supply pipe 5 from the end to the die coater 4, suction side work pipe 7 branched from the suction side supply pipe 3 to the suction end of the supply pump 6,
A discharge side work pipe 8 from the discharge end of the supply pump 6 to the paint container 1 and a communication pipe 9 for connecting the discharge side supply pipe 5 and the discharge side work pipe 8 are provided. 10, 11 and 1
Reference numeral 2 is a valve installed in each pipe. In addition,
In addition to the above, a supply pipe 14 that branches from the suction side work pipe to the supply paint container 13 is provided, and the valve 1
It is preferable to provide No. 9 because the paint replenishment work can be performed in parallel with the painting work. The operation of the paint supply device will be described. First, as the prime work, the valves 10, 1
The supply pump 6 is operated with the valves 1 and 12 open and the valve 19 closed. Then, the paint in the paint container 1 is supplied to the suction side supply pipe 3, the suction side work pipe 7 and the discharge side work pipe 8.
And is circulated to the paint container 1 via a pipe, but a part of it circulates through the suction side supply pipe and the communication pipe 9 downstream from the branch point with the suction side work pipe.
And the discharge side supply side pipe 5. When the paint is filled up to the suction end of the metering pump 2, the supply pump 6 is stopped. Next, when the valves 10 and 11 are closed and the metering pump is operated, the paint reaches the suction end of the metering pump 2 from the paint container 1 through the suction side supply pipe by the siphon action, and is delivered by the metering pump 2 and supplied on the discharge side. It flows through the pipe 5 and is supplied to the die coater 4.

According to this method, although the supply of the paint can be controlled with high accuracy, there is a problem that the paint level in the paint container 1 decreases as the painting work progresses, and thus the back pressure of the metering pump 2 decreases. . In general, the difference in height between the paint container 1 and the metering pump 2 is not so large due to work restrictions, so a decrease in back pressure causes cavitation, which may cause bubbles in the paint. When die coating is performed with a paint containing air bubbles, defects occur in the coating film, so the air bubbles must be avoided.

The present invention maintains the high accuracy of the metering pump,
Moreover, it is an object of the present invention to provide a paint supply method capable of reliably avoiding generation of bubbles.

[0006]

According to the present invention, it is possible to prevent the coating liquid level of the coating container from decreasing as the coating work progresses.
Compensate by tilting or lifting the paint container,
Maintain a constant level of paint level. As a result, the back pressure of the metering pump 2 is also kept constant, and it is possible to prevent bubbles from being generated in the paint. In order to keep the coating liquid level constant, it is preferable to tilt the coating container rather than lifting it with a jack or the like. Because the distance between the metering pump and the paint container changes over time with the method of lifting with a jack etc., a long flexible pipe must be used, and the flow rate due to siphon action is small due to pressure loss in the pipe. Become. Using thick pipes to reduce pressure loss has problems in cleaning and handling. Further, since the position of the paint container becomes higher, various inconveniences occur in the work.

The present invention will be described in more detail with reference to the drawings. FIG. 1 is a modification of the apparatus shown in FIG. 2 to conform to the present invention. In FIG. 1, the paint container 1 is fixedly mounted on the tilting mechanism 15. The tilting mechanism has a container mounting table 16 that can be rotated right and left around a rotation axis, and an arc-shaped guide rail 17. When the container mounting table 16 is rotated along the guide rail, the paint container 1 mounted on it tilts, and it is possible to compensate for the decrease in the liquid level of the paint due to the withdrawal of the paint. The operation of the apparatus shown in FIG. 1 will be described. After performing the prime work as described above, the supply pump 6 is stopped and the metering pump 2 is operated to perform the painting work.
Since the liquid level of the paint in the paint container 1 decreases as the painting work progresses, this is detected by the pressure gauge 18 as a change in the back pressure of the metering pump 2, and the tilting mechanism 15 is operated so that the back pressure returns to the reference value. Then, the paint container 1 is tilted. This operation can be performed manually, but it is preferable to adopt an automatic control system in which a signal from the pressure gauge 18 is received and the drive motor of the tilting mechanism is operated based on the signal. The tilting mechanism includes
It is safe to provide a limit switch that regulates the upper limit of tilt so that the paint container does not tilt more than a certain angle. Further, when the tilting angle of the tilting mechanism reaches a certain value, it is preferable that the supply pump 6 is automatically operated to replenish the paint from the replenishing paint container. When the paint flows into the paint container 1, the pressure detected by the pressure gauge 18 increases, so that the tilting mechanism is driven in the opposite direction to return the paint container 1 to the initial upright position. When this paint is automatically replenished, a limit switch is provided to regulate the lower limit of tilting so that the paint does not flow in even after the paint container stands upright, and the feed pump is supplied when tilting returns to this lower limit. Is preferably stopped automatically. If this tilting mechanism is used, the suction side supply pipe can be made into a fixed pipe only by making the outlet portion of the paint container flexible. Therefore, since the pressure loss of the pipe is small, a large flow rate can be secured by the siphon action even with a thin pipe, and the pipe can be easily washed.

[0008]

According to the present invention, die coating can be performed with extremely high precision, and an excellent coating film can be formed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of one example of a device suitable for practicing the present invention. The omitted parts are the same as those in FIG.

FIG. 2 is an example of a device on which the present invention is based.

[Explanation of symbols]

 1 paint container 2 metering pump 3 suction side supply pipe 4 die coater 5 discharge side supply pipe 6 supply pump 7 suction side work pipe 8 discharge side work pipe 9 communication pipe 10 valve 11 valve 12 valve 13 replenishment paint container 14 replenishment pipe 15 Tilt mechanism 16 Container mounting table 17 Guide rail 18 Pressure gauge 19 Filtration device

Claims (3)

[Claims] 1. A paint container, a metering pump installed at a position lower than the paint liquid level of the paint container, a suction side supply pipe connecting the suction end of the metering pump and the paint container, and a discharge end of the metering pump. Discharge side supply pipe connecting with a die coater, in a method for quantitatively supplying paint to a die coater using a paint supply device provided, by inclining or raising the paint container according to extraction of the paint from the paint container,
A method characterized in that the suction end pressure of a metering pump is maintained constant. 2. A paint container, a tilting mechanism for mounting and tilting the paint container, a metering pump installed at a position lower than the paint liquid level of the paint container, and connecting the suction end of the metering pump and the paint container. A paint supply device for a die coater, comprising: a suction side supply pipe; a discharge side supply pipe connecting a discharge end of a metering pump and a die coater; and a tilting mechanism control means. 3. The tilting mechanism control means detects the pressure at the suction end of the metering pump, and tilts the tilting mechanism so as to maintain the pressure constant. Supply device.