JP2010022938A - Coater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coater which enables a uniform and good coating by producing little displacement due to a bend of a coating roll in the coater provided with the coating roll having a relatively small roll diameter and an axial direction length, and a doctor blade abutting-acting to the coating roll. <P>SOLUTION: The coater has a liquid bath 1 housing a coating liquid 2, a coating roll 3 arranged so as to immerse a part thereof in the coating liquid 2 and forming a coating film 2a to a web 5 running while contacting the coating liquid 2 adhered to the outer peripheral surface with the upper part side, and a doctor blade 7 carrying out a first abutting action to the outer peripheral surface of the coating roll 3. A plurality of doctor blades 7, 8 are provided and include a doctor blade 8 abutting-acting upward at the downward side from the shaft center of the coating roll 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coating roll type coating apparatus provided with a doctor blade for adjusting the amount of coating liquid adhering to an outer peripheral surface.

  For example, as a coating apparatus used for gravure printing or the like, a coating roll having a doctor blade for adjusting the amount of coating liquid adhering to the outer peripheral surface is used, and the coating adhering to the outer peripheral surface by immersion in the coating liquid is used. 2. Description of the Related Art A coating roll type coating apparatus is known in which the amount of a working liquid is adjusted by a doctor blade and then transferred onto the surface of a web traveling in the opposite direction to the roll to form a coating film.

The coating roll of such a coating apparatus varies depending on the type and purpose of the web to be coated. However, the roll width clogging axial length is 2 m or more and the roll diameter is relatively large up to 100 mm. Small rolls may be used. Such a coating roll is relatively small in diameter and long in the axial direction. As shown in FIG. 4, in the state where it is supported by being supported at both ends as shown in FIG. It is inevitable that the so-called bend is generated due to the displacement in the lower side. The displacement b due to this bend may exceed 200 microns, and therefore there is a risk of affecting the coating state, for example, the thickness of the coating film formed on the surface of the web by the coating roll 3 becomes uneven. .
JP-A-5-96218

  The present invention solves the above-mentioned problems by providing a coating apparatus comprising a coating roll having a relatively small roll diameter and a long axial length, and a doctor blade that abuts against the coating roll. It is an object of the present invention to provide a coating apparatus that can perform uniform and satisfactory coating while hardly causing displacement due to bending of a work roll.

  A liquid tank that contains the coating liquid, and a web that is disposed so as to be partially immersed in the coating liquid in the liquid tank, and that travels by sliding the coating liquid adhered to the outer peripheral surface to the upper side. In a coating apparatus comprising a coating roll that forms a coating film and a doctor blade that abuts against the outer peripheral surface of the coating roll, as the doctor blade, the upper side below the axis of the coating roll It is characterized by comprising a doctor blade that abuts against the direction.

  In the coating apparatus, as a doctor blade that abuts against the coating roll, the abutting action is performed in order to adjust the coating liquid adhesion amount of the coating roll at a position above the coating roll axis. The first doctor blade and the second doctor blade that abuts upward on the lower side of the axis of the coating roll can be provided.

  The said coating apparatus WHEREIN: The doctor blade which contact | abuts upwards with respect to the outer peripheral surface of the said coating roll shall be provided by being immersed in the coating liquid in a liquid tank.

  In each of the above-described coating apparatuses, it is preferable that the doctor blade that is in contact with the upward direction is provided so as to be in contact with the axial center of the coating roll in a substantially vertical direction. Further, it is preferable that the coating roll rotates in a direction opposite to the traveling direction of the web of the object to be coated.

  According to the coating apparatus of the present invention, even when the roll diameter is 100 mm or less and the roll width, that is, the elongated coating roll having an axial length of 2 m or more, the upward contact of the doctor blade is upward. Due to the supporting effect by the action, the displacement of the coating roll due to its own weight, that is, the generation of a bend can be suppressed. As a result, the thickness of the coating film by the coating roll can be made uniform as a whole, and a good coating can be applied.

  Next, embodiments of the present invention will be described based on examples shown in the drawings.

  FIG. 1 is a schematic explanatory view of the main part of the coating apparatus of the present invention, FIG. 2 is an enlarged cross-sectional view of the main part, and FIG. 3 is a cross-sectional view of the main part showing another embodiment.

  In the figure, reference numeral 1 denotes a liquid tank for storing a coating liquid 2 such as printing ink for gravure printing, and reference numeral 3 denotes an applicator in which a lower side portion is immersed in the coating liquid 2 in the liquid tank 1 and rotates. It is a coating roll as a roll, and is provided so that the coating liquid 2 adheres to the outer peripheral surface by the rotation of the coating roll 3 and is fed to the upper side. The coating roll 3 is a roll made of metal such as stainless steel or iron, and varies depending on the type and width of the web to be coated, which will be described later, but mainly has a roll diameter of 100 mm or less, a roll width, that is, an axial length. It consists of a relatively long roll body having a length of 2 m or more. The coating roll 3 is supported by bearings (not shown) at shaft portions at both ends of the roll, and a roll portion below the shaft portion is immersed in the coating liquid 2 and supported so as to be rotationally driven.

  Reference numeral 5 denotes a synthetic resin film or paper as a substrate to be coated, or a web as a metal foil or other base material, and an upper portion of the coating roll 3 by a backup roll or guide roll 6 paired with the coating roll 3. It is provided so as to slide in contact with the side peripheral surface and run in the direction opposite to the rotation direction of the coating roll 3, and the outer periphery by rotation of the coating roll 3 at the sliding contact portion with the coating roll 3. The coating liquid 2 adhered and fed to the surface is applied to the surface (lower surface) on the sliding side of the web 5 to form a coating film 2a.

  In the coating roll 3, the coating liquid 2 adhering surface side is brought into contact with the outer peripheral surface of the roll before reaching the sliding contact portion of the web 5. A metal first doctor blade 7 is provided to limit and adjust the amount and position of the coating liquid 2 to be deposited by scraping the liquid 2, thereby forming the coating film 2 a on the web 5. The position, film thickness, etc. can be adjusted and set.

  In the case of the present invention, separately from the first doctor blade 7 which performs a normal function, a metal made of abutting action on the lower side of the axis of the coating roll 3 including the diagonally upper side. A second doctor blade 8 is disposed, and a plurality of doctor blades are provided as a whole. The second doctor blade 8 adheres to the outer peripheral surface of the roll by abutting upward on the outer peripheral surface of the coating roll 3 on the coating liquid adhesion side, as in the case of a normal doctor blade. The coating liquid 2 is scraped off and provided to play a role of suppressing bending deformation, that is, bend, in the axial central portion due to the weight of the coating roll 3.

  The second doctor blade 8 may be located at a position below the axis of the coating roll 3, but in practice, from the standpoint of the effect of supporting the bending of the coating roll 3, the outer circumference of the roll It is desirable to provide the lower half of the surface so as to abut on a position 30 ° or more below the horizontal plane including the axis. Further, the second doctor blade 8 is provided so as to contact the coating liquid adhering side of the coating roll 3 above the liquid surface of the coating liquid 2 as shown in FIG. As described above, the coating liquid 2 in the liquid tank 1 can be provided so as to abut on the coating roll 3 in the upward direction.

  The second doctor blade 8 is provided so as to come into contact with the non-adhering side of the coating liquid on the outer peripheral surface of the coating roll 3 because of the scraping action of the coating liquid as a doctor blade. In addition, the metal doctor blade such as blade steel and the coating roll are in contact with each other without interposing the coating liquid, resulting in problems such as damage to the coating roll 3. It is not preferable.

  Further, although not shown, the first doctor blade 7 and the second doctor blade 8 can be implemented by arranging either one or a plurality of both in parallel. Further, one or a plurality of second doctor blades 8 provided below the axis of the coating roll 3 may also serve as the first doctor blade.

  In any case, the eighth doctor blade 8 abuts in a direction substantially perpendicular to the axis of the coating roll 3 (including a direction slightly deviated from the axis). It is particularly preferable to provide the coating roll 3 in terms of the effect of suppressing the bend of the coating roll 3.

  According to the coating apparatus of the above-described embodiment, the synthetic resin film that is the object to be coated, the web 5 as a paper or other base material is caused to slide in contact with the upper part of the coating roll 3, and at the same time the liquid tank Coating is performed by rotating the coating roll 3 in which the lower part is immersed in the coating liquid 2 in 1. That is, by the rotation of the coating roll 3, the coating liquid 2 adheres to the outer peripheral surface of the roll and is lifted, and is fed to the upper side where the web 5 is slidably running. By the scraping action by the second doctor blade 8 and the first doctor blade 7 which are in contact with the outer peripheral surface of the coating roll 3, in particular, the adhesion side portion of the coating liquid 2, The excess coating liquid 2 adhering to the surface is scraped off, and a necessary amount of the coating liquid 2 is fed to the portion where the web 5 is slidably traveling, and slidably travels to the coating roll 3. The coating liquid 2 is transferred to the web 5 being formed to form a coating film 2a.

  And in the coating apparatus of this invention, since it is equipped with the doctor blade which contact | abuts the upper direction below the axial center of the said coating roll 3, ie, the said 2nd doctor blade 8, this doctor blade 8 can suppress the bending of the coating roll 3 pivotally supported at both ends by bending under its own weight, and the bend displacement is extremely small, and the coating film has a uniform film thickness. Can be formed.

  For example, when a coating roll 3 having a roll diameter of 62 mm and an axial length of 1500 mm is pivotally supported at both ends, the conventional coating apparatus is displaced by a bend of 250 microns at the center due to its own weight. However, in the case of the present invention provided with the second doctor blade 8 that abuts against the coating roll 3 in the upward direction, the displacement of the bend is 10 microns or less, and a vent is almost generated. It became nothing. In particular, the above-described effect becomes more remarkable as the second doctor blade 8 is arranged on the lower side of the coating roll 3.

  The coating apparatus of the present invention is not limited to a coating apparatus for gravure printing, for example, but a coating apparatus including other doctor blades, in particular, a roll diameter of 100 mm or less and a roll width, that is, an axial length of 2 m or more. It can be suitably used when a coating roll having a holding length is used.

It is a schematic explanatory drawing of the principal part of the coating apparatus of this invention. It is an expanded sectional view of the principal part. It is sectional drawing of the principal part which shows the other Example of this invention. It is explanatory drawing of the vent phenomenon of a coating roll.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid tank, 2 ... Coating liquid, 2a ... Coating film, 3 ... Coating roll, 5 ... Web, 6 ... Guide roll, 7 ... 1st doctor blade, 8 ... 2nd doctor blade.

Claims (5)

  A liquid tank that contains the coating liquid, and a web that is disposed so as to be partially immersed in the coating liquid in the liquid tank, and that travels by sliding the coating liquid adhered to the outer peripheral surface to the upper side. In a coating apparatus comprising a coating roll that forms a coating film and a doctor blade that abuts against the outer peripheral surface of the coating roll, as the doctor blade, the upper side below the axis of the coating roll A coating apparatus comprising a doctor blade that abuts against a direction.   A first doctor blade acting as an abutting action for adjusting the coating liquid adhesion amount of the coating roll at a position above the coating roll axis, as the doctor blade acting as an abutting action on the coating roll; The coating apparatus according to claim 1, further comprising a second doctor blade that abuts upwardly on a lower side than the axis of the coating roll.   The coating device according to claim 1 or 2, wherein a doctor blade that abuts upward on the outer peripheral surface of the coating roll is provided by being immersed in a coating solution in a liquid tank.   The coating device according to any one of claims 1 to 3, wherein the doctor blade that abuts upward is provided so as to abut in a direction substantially perpendicular to the axis of the coating roll. .   The coating apparatus according to any one of claims 1 to 4, wherein the coating roll is configured to rotate in a direction opposite to a traveling direction of a web of an object to be coated.

Images