JP2002186888A - Gravure coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly apply a coating agent by a small diameter gravure roll without delaying the feed speed of a sheet material. SOLUTION: A gravure coating apparatus is equipped with the gravure roll 2 with a diameter of 40-55 mm for applying the coating agent to the surface of the sheet material 1, the coating chamber 3 arranged along the peripheral surface of the gravure roll 2 and a coating agent supply means for supplying the coating agent into the coating agent sump 9 provided to the coating chamber 3. A doctor blade 11 is arranged so as to be opposed to the rotary direction of the gravure roll 2 and the arranging angle θ of the doctor blade 11 to the tangential line (a) of the gravure roll passing the contact point of the doctor blade 11 is set to 30-45 deg. and the interval W between the leading end of the doctor blade 11 and the leading end of the seal plate 12 provided to the coating chamber 3 is set to 20-30 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravure coating apparatus provided with a gravure roll for applying a coating agent to the surface of a sheet material made of a resin film or paper in a gravure printing machine or a coating machine. It is.

[0002]

2. Description of the Related Art Conventionally, as shown in Japanese Utility Model Publication No. 2-7663, the lower surface of a base material (sheet material) on a running continuum at a position where the upper surface is free. And a diameter of about 20mm ~
A gravure roll having a diameter of about 50 mm, and a doctor blade (doctor blade) for wiping excess coating agent from the surface of the gravure roll before application and supplying a fixed amount of coating agent to the coating unit are provided. 2. Description of the Related Art A fixed amount of a coating agent measured via a doctor blade is supplied to a coating unit, and the coating agent is uniformly applied by a small-diameter gravure roll.

[0003]

When a coating agent is applied to a sheet material using a gravure roll having a relatively small diameter as described above, the coating agent is supplied to the gravure roll. Since the space for installing the doctor blade formed between the coating material supply unit to be formed and the sheet material is narrow, the doctor blade 11 is arranged at a regular angle along the rotation direction of the gravure roll 2 as shown in FIG. Inevitably, the setting angle θ of the doctor blade with respect to the tangent a of the gravure roll 2 passing through the contact point of the doctor blade 11 is limited to about 30 °, and when the conveying speed of the sheet material 1 is increased, the doctor blade 11 Insufficient scraping action of the coating agent makes it impossible to apply the coating agent uniformly, and the coating agent flowing out from both ends of the sheet material adheres to the back side of the coating agent. Phenomenon is easy to occur There was a problem that.

That is, in order to apply an appropriate amount of coating agent to the sheet material 1 conveyed at high speed by the small-diameter gravure roll 2 as described above, the gravure roll 2
It is necessary to increase the rotation speed. When the doctor blade 11 is arranged at a regular angle along the rotation direction of the gravure roll 2 as described above, a large force acts in the direction in which the doctor blade 11 separates according to the rotation of the gravure roll 2. become. For this reason, the contact pressure of the doctor blade 11 against the gravure roll 2 is reduced, and the action of scraping the coating agent is likely to be insufficient. To prevent this, the conveying speed of the sheet material must be 100 m / min or less. There was a problem that it was necessary to keep the speed low.

In order to prevent the back-flow phenomenon of the coating agent from occurring even if the conveying speed of the sheet material 1 is increased as described above, the coating surface length (plate making dimension) of the gravure roll 2 must be reduced. It is necessary to make the width shorter than the width of the sheet material 1.
In the case of such a configuration, there is a problem that the coating surface length of the gravure roll 2 must be changed in accordance with the width dimension of the sheet material 1.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a gravure coating method in which a coating agent can be uniformly applied by a small-diameter gravure roll without reducing the conveying speed of a sheet material. It is intended to provide a device.

[0007]

According to the first aspect of the present invention,
40 mm to 55 mm for applying a coating agent on the surface of the sheet material
Gravure roll, a coating chamber installed along the peripheral surface of the gravure roll, and a coating agent supply means for supplying the coating agent into a coating agent reservoir provided in the coating chamber And a doctor blade for removing excess coating agent attached to the gravure roll while sealing the downstream side in the roll rotation direction of the coating agent pool,
A seal plate for sealing the upstream side of the coating agent pool in the roll rotation direction is provided in the coating chamber, and the doctor blade is installed so as to face the rotation direction of the gravure roll, and a contact point of the doctor blade is provided. Angle of the doctor blade to the tangent line of the gravure roll passing through
° to 45 °, and the distance between the tip of the doctor blade and the tip of the seal plate is 20 to 30 mm.
It is set within the range of mm.

According to the above construction, the doctor blade is installed at a predetermined angle so as to face the rotation direction of the gravure roll. Therefore, even if the rotation speed of the gravure roll is increased, the doctor blade does not separate. The coating agent supplied to the coating agent pool of the coating chamber by the coating agent supply means,
After the coating agent adheres to the peripheral surface of the gravure roll according to the rotation of the gravure roll and the excess coating agent is effectively removed from the gravure roll by the doctor blade, an appropriate amount of the coating remaining on the peripheral surface of the gravure roll is removed. An agent will be applied to the surface of the sheet material.

According to a second aspect of the present invention, in the gravure coating apparatus according to the first aspect, a coating chamber is disposed so as to face one side surface of the gravure roll, and an installation position of the coating chamber is provided. On the other side of the gravure roll, the sheet material is conveyed in the vertical direction so as to contact the other side surface of the gravure roll.

According to the above configuration, when the coating chamber is installed so as to face one side surface of the gravure roll, the installation space can be reduced, and
The coating chamber can be easily installed in an existing gravure printing machine or coating machine.

According to a third aspect of the present invention, there is provided the gravure coating apparatus according to the first or second aspect, wherein the gravure roll and the coating chamber and a first member for guiding a sheet material introduced into a gravure roll installation portion are provided. The coating unit is configured by attaching a guide roll and a second guide roll that guides the sheet material led out from the installation portion of the gravure roll to a common mounting plate.

According to the above configuration, the coating unit formed by mounting the above members on the common mounting plate can be easily installed on the gravure printing machine or the coating machine.

[0013]

1 and 2 show an embodiment of a gravure coating apparatus according to the present invention. The gravure coating apparatus is provided with a gravure roll 2 for coating a coating material such as a coating agent or a printing ink on a surface of a sheet material 1, and a gravure roll 2 facing one side surface of the gravure roll 2. The first and second guides that guide the coated coating chamber 3 and the other side of the gravure roll 2 while guiding the sheet material 1 conveyed upward from below on the opposite side of the coating chamber 3 Rolls 4 and 5 and coating agent supply means 6 for supplying a coating agent to the coating chamber 3 are provided. The gravure roll 2, the coating chamber 3, and the first and second guide rolls 4 and 5 are mounted on a common mounting plate 7, so that the surface of the sheet material 1 conveyed upward from below is coated. A coating unit 8 for coating the agent is configured.

The gravure roll 2 comprises a plate cylinder of a gravure printing machine or a coating roll of a coating machine, and has a diameter D set to about 40 mm to 55 mm. The gravure roll 2 is configured to rotate in a direction opposite to the conveying direction of the sheet material 1 by being driven in a counterclockwise direction in the drawing.

As shown in FIG. 2, the coating chamber 3 has a chamber main body 10 in which a coating material reservoir 9 formed of a space opened to face the peripheral surface of the gravure roll 2 is formed. A doctor blade 11 made of a stainless steel plate or the like attached to the upper end of the front surface of the chamber body 10, that is, the downstream side in the rotation direction of the gravure roll 2,
A seal plate 12 made of a steel plate or a plastic plate is provided at the lower end of the front surface of the chamber body 10, that is, at the upstream side in the rotation direction of the gravure roll 2. A regulating member 13 for regulating the flow of the coating agent in the coating agent reservoir 9 is provided inside the coating chamber 3.

When the distal ends of the doctor blade 11 and the seal plate 12 are pressed against the peripheral surface of the gravure roll 2, the upper and lower portions of the front surface of the coating material reservoir 9 are vertically aligned with the doctor blade 11 and the seal plate. The coating agent pool 9 is sealed by the gravure roll 2 and the excess coating agent attached to the peripheral surface thereof is removed by the doctor blade 11 in accordance with the rotation of the gravure roll 2. It is designed to be scraped.

The doctor blade 11 is a gravure roll 2
And the installation angle θ of the doctor blade 11 with respect to the tangent a of the gravure roll 2 passing through the contact point of the doctor blade 11 is 30 ° to 45 °.
° is set in the range. The doctor blade 11
W between the tip of the seal plate 12 and the tip of the seal plate 12
However, the installation position and the size of the doctor blade 11 and the seal plate 12 are set so that the distance is within a range of 20 mm to 30 mm.

As shown in FIG. 1, the coating agent supply means 6 includes a coating agent tank 14 containing a coating agent made of printing ink or the like, and a coating agent in the coating agent tank 14. A coating agent supply pipe 16 provided with a feed pump 15 for sucking the agent and feeding it to the lower portion of the chamber body 10, and a coating agent in the coating agent reservoir 9 discharged from the upper portion of the chamber body 10 And a return pipe 17 for returning to the coating agent tank 14 (see FIG. 1).

By operating the feed pump 15 of the coating agent supply means 6 in the above configuration, the coating agent tank 14
The gravure roll 2 is rotationally driven at a predetermined speed while supplying the coating agent accommodated therein into the coating agent pool 9 of the coating chamber 3. As a result, the coating agent supplied into the coating agent reservoir 9 of the coating chamber 3 comes into contact with and adheres to the peripheral surface of the gravure roll 2 in a sealed state, and adheres to the peripheral surface of the gravure roll 2. The surplus coating agent thus removed is removed by the doctor blade 11. And
The coating agent adhering to the peripheral surface of the gravure roll 2 is conveyed to the contact portion between the sheet material 1 and the gravure roll 2 according to the rotation of the gravure roll 2, and is applied to the surface of the sheet material 1.

As described above, the gravure roll 2 having a diameter D of 40 mm to 55 mm for coating the surface of the sheet material 1 with the coating agent, and the coating chamber 3 installed along the peripheral surface of the gravure roll 2 And a coating agent supply means 6 for supplying a coating agent into a coating agent reservoir 9 provided in the coating chamber 3. The coating agent reservoir 9 is sealed on the downstream side in the roll rotation direction. In addition, a doctor blade 11 for removing excess coating agent adhering to the gravure roll 2 and a seal plate 12 for sealing the upstream side of the coating agent pool 9 in the roll rotation direction are provided in the coating chamber 3. Provided,
The doctor blade 11 is installed (reversely arranged) so as to face the rotation direction of the gravure roll 2, and the installation angle θ of the doctor blade 11 with respect to the tangent a of the gravure roll 2 passing through the contact point of the doctor blade 11 is set to 30. And the distance W between the distal end of the doctor blade 11 and the distal end of the seal plate 12 is set to 20 mm to 30 m.
m, the rotation speed of the gravure roll 2 can be rotated at a high speed of 1000 rpm or more. Can be coated.

That is, the diameter D of the gravure roll 2
If it is less than 40 mm, its rigidity is low and it is easy to bend, so that the doctor blade 11 causes poor scraping of the coating agent. If the diameter D of the gravure roll 2 is larger than 55 mm, the contact width between the sheet material 1 and the gravure roll 2 becomes too large, and the coating surface of the coating material on the sheet material 1 becomes rough.
Must be set within the range of 40 mm to 55 mm.

For example, by changing the diameter D of the gravure roll 2 to various values within a range of 30 mm to 60 mm,
An experiment was conducted to determine whether or not the coating blade had failed to be scraped off by the doctor blade 11 and to check the state of the coated surface of the sheet material 1. As a result, data as shown in Table 1 below was obtained. Was done. In the above experimental example,
Using the gravure roll 2 having a coating surface length of 700 mm, setting the conveying speed of the sheet material 1 to 250 m / min, and setting the doctor blade 11 with respect to the tangent a of the gravure roll 2 passing through the contact point of the doctor blade 11 Angle θ
Was set to 35 °, respectively.

[0023]

[Table 1]

From the data shown in Table 1 above, 30 mm, 3 mm
When a gravure roll 2 having a diameter D of 5 mm is used, poor scraping of the coating agent by the doctor blade 11 occurs, and when a gravure roll 2 having a diameter D of 60 mm is used, poor coating occurs. It was confirmed that this would occur. Also from this experimental example, in order to prevent the occurrence of defective scraping of the coating agent by the doctor blade 11 and to prevent the coating surface of the coating agent on the sheet material 1 from becoming rough, the gravure roll 2 Diameter D of 40 mm to 5
It was verified that it was necessary to set within the range of 5 mm.

When the installation angle θ of the doctor blade 11 with respect to the tangent line a of the gravure roll 2 passing through the contact point of the doctor blade 11 is less than 30 °, the scraping angle of the doctor blade 11 with respect to the gravure roll 2 becomes too sharp. Defective scraping of the coating agent occurs. The doctor blade 1
If the installation angle θ of the first blade 1 is larger than 45 °, the doctor blade 11 vibrates to form a pattern on the peripheral surface of the gravure roll 2 and coating failure occurs. It is necessary to set the installation angle θ of the doctor blade 11 with respect to the tangent line a in the range of 30 ° to 45 °.

For example, by changing the installation angle θ of the doctor blade 11 with respect to the tangent line a of the gravure roll 2 passing through the contact point of the doctor blade 11 to various values within the range of 25 ° to 50 °, An experiment was conducted to confirm whether or not the coating material scraping defect occurred due to the above, and to confirm the state of the coated surface of the sheet material 1. As a result, data as shown in Table 2 below was obtained. In the above experimental example, the coating surface length of 700 mm, 40 mm and 55 mm
The gravure roll 2 having a diameter D of mm was used, and the conveying speed of the sheet material 1 was set to 250 m / min.

[0027]

[Table 2]

From the data shown in Table 2 above, when the setting angle θ of the doctor blade is set to 25 °, the doctor blade 11
It was confirmed that poor scraping of the coating agent occurred due to the above, and coating failure occurred when the installation angle θ of the doctor blade 11 was set to 50 °. From this experimental example, sheet material 1
In order to ensure that the coating agent can be properly applied to the surface of the sheet material 1 without causing the above-mentioned coating agent to be scraped poorly even when the conveying speed is set to high speed, The doctor blade 11 is arranged in an opposite angle so as to face the rotation direction of the gravure roll 2, and the installation angle θ of the doctor blade 11 with respect to a tangent line a of the gravure roll 2 passing through the contact point of the doctor blade 11 is 30 ° or more. It was verified that it was necessary to set a range of 45 °.

Further, if the distance W between the distal end of the doctor blade 11 and the distal end of the seal plate 12 is less than 20 mm, the coating material is applied to the sheet material 1 and then the installation portion of the coating chamber 3 is again set. And the time during which the gravure roll 2 is immersed in the coating liquid reservoir 9 of the coating liquid chamber 3 becomes shorter, so that the coating liquid remaining on the plate surface of the gravure roll 2 becomes shorter. Clogging due to drying of the gravure roll 2 is likely to occur, and the gravure roll 2 needs to be washed at an early stage. In addition, the above interval is 30 mm
If it is larger, the balance between the size of the gravure roll 2 and the size of the coating agent chamber 3 becomes poor, and the distance S between the sheet material 1 conveyed along the gravure roll 2 and the coating agent chamber 3 is reduced. Since the workability is deteriorated due to the narrowing, the interval W between the distal end of the doctor blade 11 and the distal end of the seal plate 12 needs to be set within a range of 20 mm to 30 mm.

For example, the distance W between the distal end of the doctor blade 11 and the distal end of the seal plate 12 is 15 mm to 35 mm.
gravure roll 2
In addition to measuring the printing distance required to clean the sheet material, that is, the transport distance of the sheet material 1, an experiment was performed to confirm how the distance S between the sheet material 1 and the coating agent chamber 3 changed. As a result, data as shown in Table 3 below was obtained. In the above experimental example, a gravure roll 2 having a coating surface length of 700 mm and diameters D of 40 mm and 55 mm was used, and it was determined whether or not the clogging was likely to occur. The conveying speed of the sheet material 1 is set to a relatively low speed of about 50 m / min, and the installation angle θ of the doctor blade 11 is 35 °.
Set to.

[0031]

[Table 3]

From the data shown in Table 3 above, the doctor blade 1
In the case where the distance W between the leading end of No. 1 and the leading end of the seal plate 12 is set to 15 mm, clogging of the gravure roll 2 occurs when the printing distance becomes 1000 m, and the gravure roll 2 is washed at an early stage. It was confirmed that we had to do. When the distance W between the distal end of the doctor blade 11 and the distal end of the seal plate 12 is set to 35 mm, the distance S between the sheet material 1 and the coating material chamber 3 is reduced.
Was too narrow, about 1 mm or 1.5 mm. From this experimental example as well, in order to effectively prevent clogging of the plate surface of the gravure roll 2 and to prevent the gap S between the sheet material 1 and the coating material chamber 3 from becoming too narrow. Is the distance W between the tip of the doctor blade 11 and the tip of the seal plate 12.
Has been verified to be set within the range of 20 mm to 30 mm.

In the above embodiment, the coating chamber 3 is disposed so as to face one side of the gravure roll 2, and the sheet material 1 is placed in the vertical direction on the opposite side of the installation position of the coating chamber 3. The gravure roll 2 is configured to be brought into contact with the other side surface by transporting the gravure roll 2, so that the installation space is secured as in the case where the coating chamber 3 is disposed along the sheet material 1 transported in the horizontal direction. Therefore, the installation space can be made compact without causing a problem such as an increase in the size of the apparatus, and the coating chamber 3 can be easily installed on an existing printing machine or coating machine. There is an advantage.

Further, as shown in the above embodiment, the gravure roll 2 and the coating chamber 3, the first guide roll 4 for guiding the sheet material 1 introduced into the installation portion of the gravure roll 2, and the gravure roll 2 By attaching a second guide roll 5 for guiding the sheet material 1 led out from the installation portion to a common mounting plate 7, a coating unit 8 is provided.
Is advantageous in that the coating unit 8 can be very easily installed on a gravure printing machine or a coating machine.

[0035]

As described above, according to the present invention, a gravure roll having a diameter of 40 mm to 55 mm for applying a coating agent on the surface of a sheet material, and the gravure roll is provided along the peripheral surface of the gravure roll. A coating chamber, and coating agent supply means for supplying a coating agent into a coating agent reservoir provided in the coating chamber, and sealing a downstream side of the coating agent reservoir in a roll rotation direction. In addition, a doctor blade for removing excess coating agent adhering to the gravure roll and a seal plate for sealing the upstream side of the coating agent pool in the roll rotation direction are provided in the coating chamber, and the rotation of the gravure roll is provided. The doctor blade is installed so as to face the direction, and the installation angle of the doctor blade with respect to the tangent line of the gravure roll passing through the contact point of the doctor blade is 30 ° to 4 °.
By setting the angle in the range of 5 ° and the distance between the tip of the doctor blade and the tip of the seal plate in the range of 20 mm to 30 mm, the gravure roll can be rotated at a high speed, and the sheet material can be conveyed. There is an advantage that the coating agent can be uniformly applied by the small-diameter gravure roll without reducing the speed, and the occurrence of the back-flow phenomenon of the coating liquid can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a gravure coating apparatus according to the present invention.

FIG. 2 is a side sectional view showing a specific configuration of a coating chamber.

FIG. 3 is an explanatory view showing a conventional example of a gravure coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet material 2 Gravure roll 3 Coating chamber 4 First guide roll 5 Second guide roll 6 Coating agent supply means 7 Mounting plate 8 Coating unit 9 Coating agent pool 11 Doctor blade

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Takahiro Mizuno 2-7-1, Hachimotomatsu Iida, Higashihiroshima-shi, Hiroshima F-term (reference) in Fuji Machine Industry Co., Ltd. Hachimotomatsu Plant 4D075 AC25 AC34 AC93 DA04 DB31 4F040 AA22 BA12 CB06 CB34

Claims (3)

[Claims] 1. A method of applying a coating agent on the surface of a sheet material.
a gravure roll having a diameter of 55 mm to 55 mm, a coating chamber provided along the peripheral surface of the gravure roll, and a coating agent for supplying a coating agent into a coating agent reservoir provided in the coating chamber. With an agent supply means, while sealing the downstream side in the roll rotation direction of the coating agent pool,
A doctor blade for removing excess coating agent adhering to the gravure roll, and a seal plate for sealing the upstream side of the coating agent pool in the roll rotation direction are provided in the coating chamber, and in the rotation direction of the gravure roll, While installing the doctor blade so as to face, the installation angle of the doctor blade with respect to the tangent line of the gravure roll passing through the contact point of this doctor blade is set in the range of 30 ° to 45 °, and the tip of the doctor blade A gravure coating apparatus, wherein a distance between the seal plate and a tip portion is set within a range of 20 mm to 30 mm. 2. The gravure coating apparatus according to claim 1, wherein a coating chamber is disposed so as to face one side of the gravure roll, and a sheet material is placed on the opposite side of the installation position of the coating chamber. A gravure coating apparatus characterized in that the gravure roll is configured to be brought into contact with the other side of the gravure roll by being transported in a vertical direction. 3. The gravure coating apparatus according to claim 1, wherein the gravure roll and the coating chamber, a first guide roll for guiding a sheet material introduced into an installation portion of the gravure roll, and a gravure roll. A gravure coating apparatus, wherein a coating unit is configured by attaching a second guide roll for guiding a sheet material derived from an installation section to a common mounting plate.