JP2628159B2 - Metering roll cleaning device for reverse roll coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) [Field of Industrial Application] The present invention relates to a metering roll cleaning device that holds a constant amount of a coating agent on an applicator roll during reverse roll coating.

[Prior Art] Conventionally, a cleaning doctor blade of a metalling roll used for reverse roll coating has been constituted by a single thin steel plate having a tip with a blade and having a thickness of about 0.1 mm to 0.3 mm.

[Problems to be Solved by the Invention] In the above-described conventional technology, when hard foreign matter or pigment enters between the metalling roll surface and the cleaning doctor blade, a streak is generated on the metalling roll surface, and the coating is performed. Not only did the article become defective, but the metering roll itself became unusable. Furthermore, when a coating agent having a high pigment / resin content ratio is coated, a single cleaning doctor blade cannot wipe off the coating agent cleanly, resulting in vertical stripes and the like on the coating, resulting in a failure. There was a problem.

In order to solve the above-mentioned problems, researches have been conducted to form a cleaning doctor blade using a material other than a steel plate.

However, simply replacing the steel plate with a resin plate with low hardness does not provide the necessary stiffness as a doctor blade,
There is a problem that the scraping ability of the coating agent is reduced.

Therefore, the present invention provides a cleaning device having a high-strength cleaning doctor blade that has a high scraping ability of a coating agent on a metalling roll surface and is excellent in preventing scratches, and aims to obtain a coated product of good quality. Things.

(Constitution of the Invention) [Means for Solving the Problems] According to the present invention, the first cleaning is made of a material that is soft enough not to damage the surface of the metalling roll in contact with the metalling roll. A doctor blade and a second cleaning doctor blade made of a material having a scraping effect of a coating agent, each of which is independently and axially supported so as to be capable of adjusting the pressure on the metering roll at intervals, and installed. In addition, a metering roll cleaning apparatus for reverse roll coating, comprising a solvent dropper provided between the first cleaning doctor blade and the second cleaning doctor blade, and an air sprayer provided behind the second cleaning doctor blade. It has become.

[Operation] The coating agent on the surface of the metering roll is first scraped off by the first cleaning doctor blade, and the remaining coating agent is prevented from solidifying by the dripping solvent, and the second cleaning doctor blade is used. The blade is scraped again. Further, the solvent remaining on the roll surface is completely evaporated by blowing air.

[Example] An example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic explanatory view showing one embodiment of a reverse roll coating machine according to the present invention, wherein a metering roll cleaning device for reverse roll coating is provided around a metering roll 6 and a first cleaning doctor blade 1 is provided. And a second cleaning doctor blade 2 located behind and behind (in the direction of rotation of the metering roll 6) an interval, and the first cleaning doctor blade 1 and the second cleaning doctor blade 2 are supported on independent shafts, respectively. Have been.

The first cleaning doctor blade 1 is made of a material that is soft enough not to damage the metering roll 6, for example, a resin having excellent wear resistance such as polyester, polyamide, ultrahigh molecular weight polyethylene, and fluororesin. Also,
Since it is supported on an independent shaft, the doctor pressure of the first cleaning doctor blade 1
The pressure can be made slightly lower than a predetermined pressure so as not to damage the surface.

The second cleaning doctor blade 2 may be made of any material having an effect of scraping the coating agent, and usually a steel doctor is used.

A cotton cloth 3 is provided around the metalling roll 6 between the first cleaning doctor blade 1 and the second cleaning doctor blade 2 so as to lightly contact the metalling roll 6. Further, a solvent dropper 8 is arranged between the first cleaning doctor blade 1 and the second cleaning doctor blade 2. The solvent dropper 8 includes a solvent pipe 4 and a solvent tank 5. One end of the solvent pipe 4 is opened on the cotton cloth 3, and the other end is connected to the solvent tank 5. The dropping of the solvent is performed by a switch as appropriate.

An air blower 7 is disposed behind the second cleaning doctor blade 2 (that is, in the rotation direction of the metering roll 6). The air blowing direction of the air blowing device 7 is preferably configured to be blown in the opposite direction to the rotation direction of the metering roll 6, but as shown in the drawing, from just above the surface of the metering roll 6. You may make it spray. In short, what is necessary is just to comprise so that the coating agent surface on the applicator roll 9 may not be affected. The air temperature may be above room temperature, but usually room temperature is sufficient.

Next, the operation of the reverse roll coating metering roll cleaning apparatus thus configured will be described.

The metering roll 6 is moved in the direction opposite to the applicator roll 9 (in the direction of arrow B) so as to hold the coating agent 10 supplied from the supply unit 13 at a constant thickness on the applicator roll 9 rotating in the direction of arrow A. By rotating, the excess coating agent 10 on the applicator roll 9 is deposited on the surface of the metering roll 6. The coating agent 10 on the surface of the metering roll 6 is first scraped off by the first cleaning doctor blade 1. However, the coating agent 10 remaining on the surface of the metering roll 6 without being completely scraped off due to the weakness of the first cleaning doctor blade 1 is scraped off by the second cleaning doctor blade 2. At this time, if the coating speed is slow and the evaporation rate of the solvent is fast,
The coating agent scraped off by the first cleaning doctor blade 1 loses solvent and solidifies. The solidified coating agent not only reduces the scraping ability of the second cleaning doctor blade 2 but also damages the surface of the metering roll 6 by this doctor pressure. For this reason, a solvent is dropped between the first cleaning doctor blade 1 and the second cleaning doctor blade 2, and the coating agent that has been scraped off by the first cleaning doctor blade 1 is redissolved, whereby the second cleaning doctor blade 2 is removed. Maintain the scraping properties of At this time, it is preferable to provide a cotton cloth 3 that holds the solvent between the first cleaning doctor blade 1 and the second cleaning doctor blade 2 and acts to remove the coating agent. This is because when the pigment contained in the coating agent is hard, the coating agent scraped off by the first cleaning doctor blade 1 damages the second cleaning doctor blade 2 and eventually renders the coating defective. The cotton cloth 3 between the first cleaning doctor blade 1 and the second cleaning doctor blade 2 gently wipes the metering roll 6 to reliably remove the pigment of the coating agent. The durability of the second cleaning doctor blade 2 is improved, and the cotton cloth 3 can hold the solvent dropped from the solvent dropper 8.

Further, the air blowing device 7 disposed behind the second cleaning doctor blade 2 is operated to blow air onto the surface of the metering roll 6. This is because the second cleaning doctor blade 2 removes the applicator roll 9
If the solvent left unscrewed by the second cleaning doctor blade 2 does not completely evaporate within the time to reach, the coating agent on the applicator roll 9 is adversely affected by the solvent on the metering roll 6, and Becomes defective. To prevent this, air is blown to accelerate the evaporation of the solvent.

In the drawings, reference numeral 11 denotes a backup roll, and reference numeral 12 denotes an object to be coated (web).

Polyester doctor blade (Esterram E500, 0.55
Thickness), using a Swedish steel doctor blade (a doctor blade with a blade manufactured by Tokyo Seisakusho, 0.15 mm thick) as the second cleaning doctor blade 2, and using a reverse roll coating machine of the present invention, a conventional single cleaning doctor blade When a coating agent containing a hard pigment having a pigment content / resin content of 75/25 (weight ratio), which could not be coated by the method described above, was applied, a coating having good quality could be obtained.

Also, there was no scratch on the metalling roll surface, and the roll showed about 10 times the durability.

[Effect of the Invention] The use of the metalling roll cleaning device of the present invention has the following effects.

(1). In the reverse roll coating, hard foreign matter entering between the metering roll surface and the cleaning doctor blade, or preventing scratches on the metalling roll surface caused by the pigment, improving the durability of the metalling roll, and improving the durability. A quality coating can be obtained.

(2). Good quality coatings can be obtained even by coating with a coating agent having a high pigment / resin ratio, which was impossible with the prior art.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a reverse roll coating machine provided with a metering roll cleaning device of the present invention. DESCRIPTION OF SYMBOLS 1 ... 1st cleaning doctor blade, 2 ... 2nd cleaning doctor blade, 3 ... cotton cloth, 4 ... solvent pipe, 6 ... metering roll, 7 ... air sprayer, 8 ... solvent dropper , 9 ... applicator roll, 10 ... coating agent, 11 ... backup roll, 12 ... web.

Claims (1)

(57) [Claims] 1. A first cleaning doctor blade made of a material that is soft enough not to damage a surface of a metalling roll in contact with the metalling roll, and a material having an effect of scraping a coating agent around the metalling roll. And a second cleaning doctor blade which is independently supported so as to be able to adjust the pressure on the metering roll at an interval, and wherein the first cleaning doctor blade and the second cleaning doctor blade Wherein a solvent dripping device is provided between the second cleaning doctor blade and an air spray device behind the second cleaning doctor blade.