JP3314470B2 - Coating die and coating method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating die and a coating method using the same. In particular, the present invention relates to a coating die in which the paint can be easily changed during the coating operation.

[0002]

2. Description of the Related Art Die coating in which a belt-shaped object is continuously run and a coating is performed using a coating die is widely performed. Die coatings have various advantages over roll coatings and are expected to become more and more widely used in the future. As the coating die, one having a manifold for receiving paint from the outside and a flat and wide paint flow path from the manifold to the discharge end is used. By letting the discharge end of this coating die face the traveling strip, paint is supplied to the manifold by the metering pump, and flows out from the discharge end through the paint flow path.
The coating on the strip is performed. As another method, there is also known a method in which the discharge end of a coating die faces a coating roll, and the belt-shaped material is caused to travel in contact with the coating roll to perform coating. According to this method, the paint is discharged from the die onto a roll in the form of a thin film, and the paint on the roll is applied to the strip.

[0003]

Although die coating is an excellent coating method, improvements are still desired in some respects. One of them is that it takes time and effort to change the paint. Since various colors and physical properties are required for the coating film, the paint is often changed in the coating operation. Particularly in the era where recent high-mix low-volume production is required, it is necessary to frequently change the paint. In order to change the paint in the die coating, the supply of the paint must first be stopped, and the piping system from the coating die and the paint container to the paint die must be cleaned. Only after this preparatory work is completed, painting with a new paint is started. This preparation takes a lot of time and effort,
Coating equipment productivity is greatly reduced. Therefore, the present invention
An object of the present invention is to provide a coating die in which the paint can be easily changed during the coating operation.

[0004]

In the coating die according to the present invention, the manifold is divided into upper and lower parts by partition walls, each of which is provided with a paint receiving port, and the partition extends into the paint flow path. And this part is made of a flexible material. In the coating die according to the present invention, the partition wall extending into the paint flow path acts as a valve, and only paint from one of the upper and lower manifolds flows into the paint flow path.

For example, when a paint is supplied to a lower manifold (in this specification, the lower manifold and the upper manifold indicate a lower portion and an upper portion of a manifold divided up and down by a partition wall), a coating operation is performed. Due to its flexibility, the partition wall extending into the paint flow path is pushed upward by the pressure of the paint flowing out from the lower manifold, and comes into close contact with the upper surface of the paint flow path. Next, when the supply of the paint to the lower manifold is stopped and the paint is supplied to the upper manifold, the partition extending into the paint flow path is pushed down by the pressure of the paint flowing out of the upper manifold, and the lower surface of the paint flow path is lowered. Adhere to Therefore, the remaining paint in the lower manifold is prevented by the partition walls from flowing out into the paint flow path.

The present invention will be described in more detail with reference to the drawings. FIG. 1 schematically shows an example of a coating die according to the present invention and a paint supply piping system of the die. In the figure, reference numeral 1 denotes a coating die. The main part of the die includes an upper blade 2 and a lower blade 3. The upper blade 2 and the lower blade 3 are respectively formed with manifold recesses 4, 4 'and subsequent flat portions 5, 5' for paint flow passages. Reference numeral 6 denotes a partition wall which vertically divides the manifold formed by the manifold recesses 4 and 4 ', and extends into the paint flow path. The partition 6 is usually made of a thin metal or plastic plate, for example, having a thickness of 100
Aluminum plate of ~ 300μm and thickness of 200 ~ 500μ
Preferably, the manifold is made of a highly flexible material such as a Teflon sheet of m, but if desired, the portion that partitions the manifold up and down is a material of high rigidity, and the portion that extends into the paint channel that follows is It is also possible to manufacture each of the above-mentioned materials having high flexibility and combine them to integrate them. The length of the paint flow path in the coating die, that is, the length from the paint outflow end of the manifold to the paint discharge end at the tip of the die is usually 30 to 100 mm. Is enough. The depth of the paint flow path, that is, the distance between the upper blade and the lower blade is usually 200
４００400 μm. If desired, in the portion where the partition extends, the distance between the upper blade and the lower blade may be increased by the thickness of the partition.

As described above, during the coating operation, the partition must be brought into close contact with the flow path surface of the upper blade or the lower blade due to the pressure difference. Since it must be greatly deformed, the adhesion tends to be insufficient. Therefore, in order to ensure close contact at this portion, it is preferable that the side walls and the partition walls have different rigidities. For example, when an aluminum plate is used as the partition, it is preferable to form the side wall with a flexible material such as silicon rubber as shown in FIG. When a flexible plastic sheet such as a Teflon sheet is used as the partition wall, the side wall may be made of steel like the other parts of the die.

Reference numerals 7, 7 'designate paint inlets for supplying paint to the upper and lower manifolds, respectively. In a preferred embodiment of the coating die according to the present invention, a paint receiving port is provided on one side of the die, and a cleaning liquid outlet is provided on the other side. This cleaning liquid outlet is closed during the coating operation, but is used as a discharging port for the cleaning liquid from the manifold when the coating operation is completed and the inside of the system is cleaned. Reference numeral 8 denotes a first paint supply system pipe, 9 denotes a pump provided in the pipe system, and 10 denotes a paint container. Similarly, reference numeral 8 'denotes a second paint supply system pipe, 9' denotes a pump provided in the second paint supply system pipe, and 10 'denotes a second paint container.

[0009] One of the methods of performing coating using the apparatus of FIG.
To explain the example, first, the pump 9 is operated and the first
The paint in the paint container 10 is supplied to the upper manifold through the piping system. The paint flows out of the discharge end through the paint flow path, and forms a coating film on the traveling strip 11. Next, when the pump 9 is stopped and the pump 9 'is operated, the paint in the paint container 10' is supplied to the lower manifold, and flows out of the discharge end through the paint flow path to form a coating film on the traveling strip. . At this time, a large amount of paint remains in the upper manifold, but does not flow out because it is hindered by the partition walls.
Also, the paint in the paint container 10 remains in the paint flow path, but the amount is small, and the paint is pushed out by the paint in the paint container 10 'and quickly removed. Therefore, the switching of the paint is completed in a short time.

It is preferable that the first piping system and the upper manifold be cleaned while the second piping system is operating, so as to be ready for the next paint change. For cleaning, first, the suction end of the first piping system is moved from the paint container 10 to a thinner container (not shown), and the cleaning liquid outlet of the manifold is opened, and this is returned to the thinner container (shown in FIG. )). Next, when the pump 9 is operated,
The thinner circulates from the thinner container to the thinner container via the first piping system and the upper manifold, and the inside of the system is cleaned. At this time, if the pressure in the upper manifold is maintained lower than the pressure in the lower manifold by, for example, 3 to 5 kg / cm ^{2, the} partition wall adheres to the upper surface of the paint flow path due to this pressure difference, and the thinner flows into the paint flow path. I won't do it.

[0011]

According to the present invention, the paint can be switched very easily during the painting operation, so that the reduction in productivity can be minimized even in the production of many kinds and small quantities.

[Brief description of the drawings]

FIG. 1 is an example of a coating facility using a coating die according to the present invention.

FIG. 2 is a perspective view of a lower blade in one example of a coating die according to the present invention, in which a part of a side wall (hatched part) is made of silicone rubber to improve adhesion to a partition wall. ing.

FIG. 3 is a view showing a state where a partition is placed on a lower blade of FIG. 2; A die is formed when the upper blade is placed thereon and the whole is integrated.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coating die 2 die upper blade 3 die lower blade 4 manifold concave portion 5 paint flow passage flat portion 6 partition wall 7 paint receiving port 8 paint supply system piping 9 pump 10 paint container 11 strip 12 cleaning liquid outlet

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B05C 5/02 B05D 1/26

Claims (3)

(57) [Claims] 1. A coating die having a manifold having a paint receiving port and a flat and wide paint flow path from the manifold to a discharge end, for receiving paint from the outside into the manifold and flowing out from the discharge end. In, the manifold is vertically divided by a partition wall, each has a paint receiving port, this partition wall extends into the paint flow path, and at least a portion of the partition wall that extends into the paint flow path is A coating die formed of a flexible material. 2. A paint tank comprising a manifold divided vertically by partition walls, each having a paint receiving port, and a flat and wide paint flow path from the manifold to the discharge end, wherein the partition wall is formed in the paint flow path. A coating die that receives paint from the outside into each manifold and flows out from the discharge end.The die has a manifold recess and a paint passage flat portion on each inner surface. A coating die having a structure in which an upper blade and a lower blade that are formed are opposed to each other with a flexible flake serving as a partition therebetween. 3. A method for performing coating using the coating die according to claim 1 or 2, wherein the coating is performed by externally supplying a coating to one of the manifolds divided up and down by a partition. Next, after the supply of the paint is stopped, a paint different from the paint is supplied to the other manifold to perform the painting.