JPH0634868Y2 - Die coating equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION The present invention is designed to extrude a coating liquid from a slit-shaped coating liquid discharge port onto a sheet-shaped coating object made of a plastic film, metal foil, paper or the like being conveyed. The present invention relates to improvement of a die coating apparatus that coats a coating liquid film on the surface of an object to be coated.

[0002]

2. Description of the Related Art As shown in FIG. 4, a die coating apparatus 1 comprises a die coating main body 2 and a coating liquid supply apparatus 3. The die-coating main body 2 has an object W to be coated between the two lips 4 and 5.
A long slit-shaped coating liquid discharge port 6 is formed along a direction (hereinafter, referred to as a “width direction”) that crosses the coating liquid, and the coating liquid discharge port 6 is communicated between the split die heads 7 and 8. The coating liquid spreading passage 9 is formed, and the coating liquid supply port 10 is opened on the upstream side of the coating liquid spreading passage 9. In the coating liquid supply device 3, the storage tank 11, the pump 12, and the filter 13 are connected by a pipe 14, and the pipe 14 extended from the filter 13 is connected to the coating liquid supply port 1 of the die coating main body 2.
It is connected to 0. The article to be coated W is conveyed while being supported by a support tool 15 composed of a backup roll or the like, and a coating gap G having an appropriate size is formed between the article W and the lips 4 and 5 of the die coating main body 2. .

The coating liquid C-1 is supplied from the coating liquid supply device 3 to the coating liquid supply port 10 of the die coating main body 2 under pressure, and passes through the coating liquid spreading passage 9. In the meantime, it is spread in the width direction, is extruded from the slit-shaped coating liquid discharge port 6 toward the coating object W, and is applied to the surface of the coating object W to form a coating film C-2. Become.

[0004]

By the way, the pressurized coating liquid C-1 supplied to the die coating main body 2 may contain very fine bubbles. These bubbles are discharged together with the coating liquid C-1 from the coating liquid discharge port 6 of the die coating main body 2 and remain in the coating film C-2 in an expanded state, resulting in coating defects D, D ... Cause. In order to solve the above problems, the present invention aims to provide a die coating apparatus that does not discharge bubbles from a coating liquid discharge port.

[0005]

[Means for Solving the Problems] Means adopted by a die coating apparatus according to the present invention (hereinafter, referred to as "the apparatus of the present invention") is to form a slit-shaped coating liquid discharge port, and to divide a die head between division types. In the die coating apparatus, a coating liquid spreading passage communicating with the coating liquid discharge port is formed, and a coating liquid supply port is opened on the upstream side of the coating liquid spreading passage. On the way from the liquid supply port to the coating liquid discharge port, a bubble reservoir recess facing the coating liquid spreading passage is formed in a region above the coating liquid spreading passage,
That is, the discharge passage is opened in the bubble reservoir recess. In the device of the present invention, a coating liquid supply device may be provided outside the die head, and the discharge passage may be connected to a coating liquid return portion of the coating liquid supply device. Further, in the device of the present invention, an exhaust device is provided outside the die head, and the exhaust device is connected to the exhaust passage, an exhaust on-off valve that communicates with a gas storage area of the accumulator, and a gas in the gas storage area. It may be configured with a gas amount detector that detects the amount and opens / closes the exhaust on-off valve.

[0006]

[Operation] When the coating liquid containing bubbles passes through the coating liquid spreading passage, the bubbles ascend in the bubble reservoir recesses and are collected above the bubble reservoir recesses. The collected bubbles are discharged to the outside from the discharge path. Therefore, the bubble-free coating liquid is guided to the coating liquid discharge port, and the bubble-free coating liquid is extruded from the coating liquid discharge port toward the object to be coated. When the discharge passage is connected to the coating liquid return part of the coating liquid supply device, the bubbles are returned to the coating liquid return part together with a small amount of the coating liquid. Furthermore, when the exhaust device is provided, the bubbles discharged from the discharge passage are accumulated in the gas accumulation area of the accumulator. When a certain amount of gas is accumulated in the gas accumulation area, it is discharged to the outside through the exhaust opening / closing valve that is opened by the gas amount detector.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of the present invention will be described below with reference to the embodiments shown in the drawings.

First Embodiment FIG. 1 shows a first embodiment of the device of the present invention. The improvement point in this embodiment is that the die coating main body 22 is provided with a coating liquid supply port 10 to a coating liquid discharge port 6 on the way.
A bubble reservoir recess 24 facing the coating liquid spreading passage 9 is formed above the coating liquid spreading passage 9, a discharge passage 25 is opened in the bubble storing recess 24, and the discharge passage 25 is supplied with the coating liquid. This is the point connected to the storage tank 11, which is the coating liquid return unit 29 of the apparatus 3. Portions other than this improved portion are substantially the same as those of the conventional die coating apparatus 1 shown in FIG. 4, and the same reference numerals are the same components.

In the die head 8 below the die coating main body 22, as shown in the plan view of FIG. 2, a passage forming surface 8a forming a coating liquid spreading passage 9 is recessed in an appropriate shape such as a hanger shape. The coating liquid supply port 10 is opened at the center of the front side 8a-1 of the passage forming surface 8a. The bubble reservoir recess 24 is
As shown in FIG. 1, the upper die head 27 is recessed. The ceiling 24b of the bubble reservoir recess 24 is inclined upward toward the discharge port 25a of the discharge path 25, and collects the bubbles B, B ... At the discharge port 25a. The discharge port 25a of the discharge path 25 is provided at one place or a plurality of places according to the width dimension of the bubble storage recess 24. The opening 24 of the bubble reservoir recess 24
As indicated by the chain double-dashed line in FIG. 2, a is opened so as to cover the entire width direction of the coating liquid spreading passage 9, and the front side 8a-1 of the lower die head 8 on which the passage is formed. It is provided to face the right place.

As shown in FIG. 1, the upper die head 2
7, the discharge passage 25 is appropriately extended to the outside of the die head 27 by a piping tool, and its end 25b is connected to the coating liquid return unit 29 provided in the storage tank 11 or the like of the coating liquid supply device 3. ing. The discharge passage 25 is provided with a throttle valve 28 at an appropriate place as needed so that the flow rate of the RETAN coating liquid passing through the discharge passage 25 can be adjusted.

Next, the operation mode of this embodiment will be described. The coating liquid C-1 supplied from the coating liquid supply device 3 to the die coating main body 22 under pressure is spread in the width direction while passing through the coating liquid spreading passage 9, It is extruded from the slit-shaped coating liquid discharge port 6 toward the object W to be coated, and is applied to the surface of the object W to be coated as a coating film C-2. When the bubbles B contained in the coating liquid C-1 pass through the coating liquid spreading passage 9, they rise in the bubble reservoir recess 24 facing the coating liquid spreading passage 9 to rise. Collected above 24. The collected air bubbles B, B, ...
5 is discharged to the outside and returned to the coating liquid return unit 29 of the coating liquid supply device 3. Therefore, the die coating main body 22 is
The coating liquid C-1 having no bubbles is guided to the coating liquid discharge port 6, and the coating film C-2 having no bubbles can be applied to the object W to be coated.

Second Embodiment FIG. 3 shows a second embodiment of the device of the present invention. This embodiment is different from the first embodiment in that an exhaust device 30 is provided outside the die coating main body 22. The exhaust device 30 includes an accumulator 31 connected to the exhaust passage 25, an exhaust on-off valve 32 that communicates with a gas reservoir 31a of the accumulator 31, and an exhaust on-off valve that detects the amount of gas in the gas reservoir 31a. And a gas amount detector 33 for opening and closing 32.

Next, the operation mode of this embodiment will be described. The bubbles B collected above the bubble reservoir recess 24 are lifted by buoyancy and guided from the discharge path 25 to the accumulator 31 of the exhaust device 30. The bubbles B guided to the accumulator 31 accumulate in the gas accumulation area 31a as gas. The exhaust on-off valve 32 receives the detection signal of the gas amount detector 33 and opens when the predetermined amount of gas is accumulated in the gas accumulation region 31a, and discharges the gas to the outside.

Other Embodiments Incidentally, the detailed configuration and shape of the device of the present invention can be appropriately changed according to the embodiment without departing from the gist thereof. Therefore, for example, although illustration is omitted, for example, a proper place of the discharge passage 25 is narrowed, the bubbles guided to the discharge passage 25 are discharged to the outside together with a small amount of the coating liquid C-1, and the discharged coating liquid is discarded. It may be configured as follows.

[0015]

As described above in detail, since the apparatus of the present invention extrudes the bubble-free coating liquid from the coating liquid discharge port, it is possible to apply a bubble-free coating film to an object to be coated. Has a practical effect.

[Brief description of drawings]

FIG. 1 is a side view of a die head in section and a schematic view of a coating liquid supply device, showing a first embodiment of the device of the present invention.

FIG. 2 is a plan view of a lower die head in the embodiment.

FIG. 3 shows a second embodiment of the device of the present invention and is a side view in which a die head is sectioned.

FIG. 4 is a side view showing a cross section of a die head and a schematic view of a coating liquid supply device, showing a conventional die coating device.

[Explanation of symbols]

4, 5 ... Lip 6 ... Coating liquid discharge port 8, 27 ... Die head 9 ... Coating liquid spreading passage 10 ... Coating liquid supply port 24
... Bubble reservoir recess 25 ... Discharge path 3 ... Coating liquid supply device 29 ... Coating liquid return unit

Claims (3)

[Scope of utility model registration request] 1. A slit-shaped coating liquid discharge port is formed, and a coating liquid spreading passage communicating with the coating liquid discharge port is formed between split-type die heads to spread the coating liquid. In a die coating apparatus in which a coating liquid supply port is opened on the upstream side of a coating liquid passage, a bubble reservoir recess facing the coating liquid spreading passage on the way from the coating liquid supply port to the coating liquid discharge port. Is formed above the coating liquid spreading passage, and a discharge passage is opened in the bubble reservoir recess. 2. The die coating apparatus according to claim 1, wherein a coating liquid supply device is provided outside the die head, and the discharge passage is connected to a coating liquid return section of the coating liquid supply device. 3. An exhaust device is provided outside the die head, the exhaust device connects the accumulator to the exhaust passage, an exhaust opening / closing valve that communicates with a gas reservoir of the accumulator, and a gas amount in the gas reservoir. The die coating apparatus according to claim 1, wherein the die coating apparatus is configured to detect a gas and a gas amount detector that opens and closes the exhaust on-off valve.