JP2010247483A - Letterpress for coating, and coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a letterpress for coating which can change the coating amount of a coating liquid to a to-be-coated base material for each area of the to-be-coated base material, and in addition, can suppress a marginal, and to provide a coating apparatus. <P>SOLUTION: This letterpress for coating has a protruding section 11, and applies the coating liquid to the to-be-coated base material by receiving the supply of the coating liquid from an anilox to the distal end surface of the protruding section, and bringing the distal end surface into contact with the to-be-coated base material. In the letterpress for coating, a plurality of recess sections in which the coating liquid fed from the anilox can flow are formed on the distal end surface of the protruding section. When the coating amount of the coating liquid is changed for each area of the to-be-coated base material, at least one of the dimension or the forming density of the recess section corresponding to each area is changed in response to the planned coating amount. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a letterpress for coating used in a coating apparatus such as a polishing agent coating apparatus or flexographic printing, and a coating apparatus, and in particular, an application capable of applying a coating liquid to a substrate to be coated. The present invention relates to a relief printing plate and a coating apparatus.

  A flexographic printing machine, which is a kind of coating apparatus, is suitably used for applications such as film printing, label / seal printing, and paper container printing. This flexographic printing machine is a rotary printing machine and a sheet-fed printing machine using letterpress. In general flexographic printing, a coating liquid such as ink is held on the surface of an anilox roll, and the surface of the anilox roll is brought into contact with a relief plate provided on the outer peripheral surface of the plate cylinder to supply the coating liquid. The coating liquid is applied (transferred) to the substrate to be coated by pressing the relief plate against the surface of the substrate to be coated (see, for example, Patent Document 1).

  The anilox roll rotates with the rotation of the plate cylinder in a state where a part of the outer peripheral surface is pressed against the relief plate of the plate cylinder. Innumerable depressions (concave portions) called cells are engraved on the entire outer peripheral surface of the anilox roll by a laser beam or the like. And the supply amount of the coating liquid with respect to a letterpress is determined according to the formation density (line number) of a cell. The unnecessary coating liquid on the surface of the anilox is scraped off by the doctor, so that the supply amount of the coating liquid to the relief printing plate is ensured with high accuracy.

  The relief printing plate is made of an elastic member such as resin or rubber, and a portion where the coating is performed on the substrate to be coated is higher than a portion where the coating is not performed. Then, the coating liquid is supplied from the anilox roll to the tip surface of the raised portion (convex portion), and the tip surface to which the coating solution is attached is pressed against the surface of the coating substrate. Apply the coating solution to Accordingly, the coating liquid is applied to the substrate to be coated following the shape (pattern) of the convex portion. Conventionally, the front end surface of the convex portion is a flat surface. The “flat surface” means a state in which no irregularities are artificially provided on the tip surface of the convex portion, and the irregularities of the material itself are not considered. The plate cylinder having the relief printing plate is disposed in a state where a part of the relief printing plate is in pressure contact with a pressure drum provided rotatably. Then, the substrate to be coated is nipped between the plate cylinder and the impression cylinder. In this nip state, the plate cylinder and the impression cylinder rotate, and the coating material is applied by the nip pressure while feeding the substrate to be coated.

Japanese Patent Laid-Open No. 11-20123

  FIG. 6 is a diagram illustrating a coating process for a substrate to be coated by a conventional flexographic printing machine. In the figure, for convenience, the relief plate 15 and the anilox roll 16 are shown as flat plates. First, the coating solution is held in the cell 17 of the anilox roll 16 as a coating solution. In this state, as shown in FIG. 6 (a), the outer peripheral surface of the anilox roll 16 is brought into pressure contact with the tip surface of the convex portion 18 of the relief plate 15, so that as shown in FIG. The coating solution is transferred to the tip surface. Then, as shown in FIG. 6C, the tip surface of the convex portion 18 is brought into pressure contact with the substrate to be coated such as paper in a state where the coating liquid is transferred. Thereby, as shown in FIG.6 (d), the coating liquid of the front end surface of the convex part 18 is apply | coated to the to-be-coated base material 19, and an application pattern is formed.

  Here, conventionally, since the tip end surface of the convex portion 18 is a flat surface, the coating amount of the coating liquid, that is, the thickness of the coated coating liquid is constant. However, the marginal described later is excluded. For this reason, when making the application quantity of the coating liquid with respect to the to-be-coated base material 19 differ for every site | part, prepare several anilox rolls from which the number of lines of the cell 17 differs, change an anilox roll, and divide into multiple times. The coating amount was changed by performing coating. As a result, the number of man-hours is increased, and the cost is increased due to the provision of a plurality of anilox rolls.

  Further, due to the pressure when the convex portion 18 is pressed against the substrate 19 to be coated, a part of the coating liquid protrudes from between the convex portion 18 and the substrate 19 to be coated. As shown in FIG. 6 (d), there is a problem that the protruding portion rises and becomes thick while the inner portion becomes thinner. The part that protrudes and rises is called marginal. When this margin occurs, there is a problem that the contour of the coating pattern becomes larger than the pattern of the convex portion on the relief plate side, and the contour portion of the pattern becomes darker than the inner portion of the pattern. In addition, when the distance between adjacent patterns is small, the patterns may be connected.

  This invention is made | formed in view of such a situation, The objective can make the application quantity of the coating liquid with respect to a to-be-coated base material differ for every site | part of a to-be-coated base material, An object of the present invention is to provide a coating relief plate and a coating apparatus capable of suppressing marginal.

The present invention has been proposed in order to achieve the above object, and the one according to claim 1 has a convex portion, and receives a supply of a coating liquid from anilox on the tip surface of the convex portion, In the letterpress for coating that applies the coating liquid to the substrate to be coated by bringing the tip surface into contact with the substrate to be coated,
Forming a plurality of recesses into which the coating liquid supplied from the anilox can flow into the tip surface of the convex part,
In the case where the coating amount of the coating liquid is made different for each part of the substrate to be coated, at least one of the size or the formation density of the recess corresponding to each part is made different according to the planned coating amount. It is a letterpress for coating.

  According to the second aspect of the present invention, the larger the planned application amount, the deeper the dimension of the recess or the higher the formation density, while the smaller the planned application amount, the shallower the dimension of the recess or the formation density. The relief printing plate according to claim 1, wherein the relief printing plate is made lower.

The invention according to claim 3 comprises: a plate cylinder having a coating relief plate on the outer periphery; and anilox that supplies a coating solution to the coating relief plate,
The coating relief plate has a convex portion on the surface, and receives the supply of the coating liquid from the anilox to the tip surface of the convex portion, and applies the tip surface to the substrate to be coated so as to be applied to the substrate to be coated. In a coating apparatus for applying a liquid,
Forming a plurality of recesses into which the coating liquid supplied from the anilox can flow into the tip surface of the convex part,
In the case where the coating concentration of the coating liquid is made different for each part of the substrate to be coated, at least one of the dimension or the forming density of the recess is made different according to the planned coating concentration of each part. It is.

According to the present invention, the following excellent effects can be obtained.
According to the invention described in claim 1 and claim 3, since at least one of the dimension of the recess or the formation density is made different for each part according to the planned application amount for each part of the substrate to be coated. The coating amount of the coating liquid, that is, the thickness of the coating liquid can be varied for each part of the coating substrate. This eliminates the need to replace a plurality of anilox rolls having different cell line numbers or the like and perform application in multiple steps as in the prior art, and the application amount can be controlled in a single application step. Thereby, man-hours can be reduced, and it is not necessary to prepare a plurality of anilox rolls, so that the cost can be reduced.

  Moreover, since the coating liquid can flow into the recess when the convex portion of the relief plate is pressed against the substrate to be coated, the marginal can be suppressed. Thereby, the reproducibility of the coating pattern with respect to a to-be-coated base material becomes favorable. Moreover, even when the distance between adjacent patterns is small, it is possible to prevent the patterns from being connected.

It is a figure explaining schematic structure of a polish agent application device. It is an expanded sectional view explaining the structure of a letterpress. (A) is an enlarged plan view of a convex part, (b) is the sectional view on the AA line in (a). It is an expanded sectional view explaining the structure of the letterpress in 2nd Embodiment. (A)-(d) is a schematic diagram explaining an application | coating process. (A)-(d) is a schematic diagram explaining the conventional application | coating process.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following description, a polish application device will be described as an example of the application device of the present invention.

FIG. 1 is a schematic diagram showing a schematic configuration of a polish application device, and FIG. 2 is a partial cross-sectional view illustrating a configuration of a relief plate 7.
The illustrated polishing agent coating apparatus functions as a coater that applies a photocurable resin (UV resin) 6 as a coating liquid to a sheet-like substrate 5 such as paper. This polish agent coating apparatus is generally composed of an anilox roll 1, a doctor blade 2, a plate cylinder 3, and an impression cylinder 4. The anilox roll 1 can be brought into contact with or separated from the plate cylinder 3 by a driving mechanism (not shown). When the anilox roll 1 is in contact with the plate cylinder 3, the contacted outer peripheral portions are advanced in the same direction (see FIG. 1 is configured to rotate in the direction indicated by the arrow in FIG. A plurality of cells 8 (refer to FIG. 5) formed of fine concave portions are formed on the entire outer peripheral surface of the anilox roll 1. The supply amount of the coating liquid (UV resin 6) to the relief plate 7 is determined according to the size of the cell 8 or the number of lines (number of cells per inch). Further, the amount of coating can be controlled by a slight difference in rotational speed (relative slippage between the outer peripheral surfaces that come into contact with each other). For example, with the contact portion between the anilox roll 1 and the plate cylinder 3 moving at the same peripheral speed without slipping as a standard, the anilox roll 1 is rotated so that the peripheral speed is higher than that of the plate cylinder 3 to form a deep recess. Supply more coating liquid than the standard, or conversely supply slower coating liquid than the standard.

  The doctor blade 2 is disposed in a state where the tip portion is in contact with the outer peripheral surface of the anilox roll 1 along the axial direction of the anilox roll 1. When the anilox roll 1 rotates, the doctor blade 2 scrapes off the excess coating liquid adhering to the outer peripheral surface of the anilox roll 1.

  The plate cylinder 3 has an application relief plate 7 (flexographic plate) according to the present invention on its outer peripheral surface, and is rotatably arranged in contact with the anilox roll 1 and the impression cylinder 4. The relief plate 7 is made of, for example, an elastic material such as resin or rubber. As shown in FIG. 2, the base portion 10 that covers the outer periphery of the plate cylinder 3, and the opposite side from the base portion 10 to the plate cylinder 3 side. It is comprised from the convex part 11 which protruded. In the contact portion between the plate cylinder 3 and the anilox roll 1, the coating liquid on the outer peripheral surface of the anilox roll 1 is transferred to the tip surface of the convex portion 11. The characteristic part of this letterpress 7 will be described later.

  The impression cylinder 4 is disposed so as to be in pressure contact with the plate cylinder 3, and is configured such that the outer peripheral surfaces that are in pressure contact with the rotation of the plate cylinder 3 rotate in a direction that advances in the same direction. A coated substrate 5 is nipped between the plate cylinder 3 and the impression cylinder 4. Then, by rotating the plate cylinder 3 and the impression cylinder 4 in this nip state, the coating liquid adhered to the front end surface of the convex portion 11 in the plate cylinder 3 is fed while feeding the substrate 5 to be coated. It is configured to be applied (transferred).

Next, the characteristic part of the relief printing plate 7 will be described.
FIG. 3 is an enlarged view of the convex portion 11, (a) is a plan view of the convex portion 11, and (b) is a cross-sectional view taken along line AA in (a). As shown in the figure, the relief plate 7 according to the present invention is characterized in that a plurality of depressions 12 into which the coating liquid supplied from the anilox roll 1 can flow are distributedly formed on the tip surface of the projection 11. have. In the present embodiment, the recess 12 has a square opening shape in plan view, and is configured by a reverse trapezoidal shape or a V-shaped recess in which the opening shape decreases toward the bottom. Each recess 12 is formed when the relief plate 7 is made. Note that the shape of the recess 12 is not limited to that illustrated in FIG. 3, and a circular shape, a hexagonal shape, an oblique linear shape (groove-shaped recess), or the like may be employed in plan view. In the present embodiment, the number of lines of the depressions 12 on the front end surface of the projection 11, that is, the number of formations per inch is set to 80 to 150, for example.

  And when changing the application quantity of a coating liquid for every site | part of the to-be-coated base material 5, the application quantity of the coating liquid with respect to the to-be-coated base material 5 can be adjusted according to the dimension of the recessed part 12, and the number of lines. For example, in the present embodiment, the depth D (see FIG. 3B) of the recess 12 corresponding to each part is changed according to the planned application amount for each part of the substrate 5 to be coated. That is, as shown in FIG. 2, the depth of the recess 12b corresponding to a portion where the planned application amount is larger than the reference application amount is made larger than the depth of the recess 12a corresponding to a predetermined reference application amount. The depth of the recess 12c corresponding to a portion where the planned application amount is smaller than the reference application amount is made shallower. Thereby, since the volume of each recessed part 12 changes, the quantity of the coating liquid which can be hold | maintained in a recessed part also differs. That is, in the recess 12b having a deeper depth, the amount of coating liquid that can be retained is increased than in the recess 12a corresponding to the reference application amount, and in the recess 12c having a shallower depth, the recess 12b is retained than in the recess 12a. The amount of possible coating liquid is reduced. The depth D of the recess 12 is set within a range of several μm to several tens of μm. Of course, it is not restricted to the depth of the recessed part 12, The quantity of the coating liquid which can be hold | maintained can also be changed by varying dimensions other than the depth of the recessed part 12. FIG. In this case, the dimension can be set within a range in which adjacent recesses do not interfere with each other.

Next, with reference to FIG. 5, the application | coating process by the said polish agent coating device is demonstrated.
First, the coating solution is held in the cell 8 of the anilox roll 1 as a coating solution. In this state, as shown in FIG. 5A, the outer peripheral surface of the anilox roll 1 is brought into pressure contact with the tip surface of the convex portion 11 of the relief plate 7 in the plate cylinder 3, as shown in FIG. The coating liquid is transferred to the tip surface of the convex portion 11. At this time, a part of the transferred coating liquid flows into each recess 12 and is held. And as shown in FIG.5 (c), the front end surface of the convex part 11 is press-contacted to the to-be-coated base materials 5, such as paper, in the state which the coating liquid adhered. Thereby, as shown in FIG.5 (d), the coating liquid hold | maintained at the front end surface of the convex part 11, and each recessed part 12 is transcribe | transferred to the to-be-coated base material 5, and a coating pattern is formed. In this embodiment, since the UV resin is applied as the coating liquid, after the application to the substrate 5 to be applied, the UV resin is coated on the UV resin on another stage, and the light is passed through the film with an ultraviolet lamp or the like. The film is peeled off and the glossy surface of the film is transferred to the UV resin.

  As described above, the depth of the recess 12 corresponding to each part is changed according to the planned application amount for each part of the substrate 5 to be coated. The coating amount of the liquid, that is, the thickness of the coating liquid can be varied. This eliminates the need to replace a plurality of anilox rolls having different cell line numbers or the like and perform application in multiple steps as in the prior art, and the application amount can be controlled in a single application step. Thereby, the number of man-hours can be reduced, and it is not necessary to prepare a plurality of anilox rolls 1, so that the cost can be reduced.

  Further, when the convex portion 11 of the relief plate 7 is pressed against the substrate 5 to be coated, the coating liquid can flow into (escape from) the concave portion 12, so that marginal can be suppressed. Thereby, the reproducibility of the coating pattern with respect to the to-be-coated base material 5 becomes favorable. Moreover, even when the distance between adjacent patterns is small, it is possible to prevent the patterns from being connected.

By the way, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the description of the scope of claims.
For example, in the said embodiment, although the structure which varies the application quantity of a coating liquid for every site | part of the to-be-coated base material 5 by varying the depth of the recessed part 12 was illustrated, for example, the 2nd shown in FIG. As in the embodiment, the formation density (number of lines) of the recesses 12 may be varied. In the second embodiment, the number of lines of the recess 12b corresponding to the part where the planned application amount is larger than the reference application amount is larger than the number of lines of the recess 12a corresponding to the part where the planned application amount is the reference application amount. In addition, the number of depressions 12c corresponding to a portion where the planned application amount is smaller than the reference application amount is reduced. That is, the higher the density of the depressions 12, the more the amount of coating liquid that can be held, and the more the density of the depressions 12, the smaller the amount of coating liquid that can be held.
Further, by changing both the depth of the recess 12 and the formation density, the coating amount can be controlled more finely.
Furthermore, the base material 5 to be coated is not limited to a continuous sheet-like base material, and may be, for example, a sheet of paper.

  Note that the present invention is not limited to the illustrated polishing agent coating apparatus as long as the coating liquid is applied to the substrate to be coated using a relief printing plate, for example, a rotary printing machine such as a flexographic printing machine or a flat printing machine. The present invention can also be applied to a pressure relief printing machine.

  DESCRIPTION OF SYMBOLS 1 ... Anilox roll, 2 ... Doctor blade, 3 ... Plate cylinder, 4 ... Impression cylinder, 5 ... Substrate to be coated, 6 ... Coating material, 7 ... Letter plate, 11 ... Convex part, 12 ... Concave part

Claims (3)

In the relief printing plate for applying the coating liquid to the substrate to be coated by receiving the supply of the coating liquid from the anilox on the tip surface of the convex part and bringing the tip surface into contact with the substrate to be coated.
Forming a plurality of recesses into which the coating liquid supplied from the anilox can flow into the tip surface of the convex part,
In the case where the coating amount of the coating liquid is made different for each part of the substrate to be coated, at least one of the size or the formation density of the recess corresponding to each part is made different according to the planned coating amount. Letterpress for coating.   The larger the planned application amount, the deeper the dimension of the recess or the higher the formation density, while the smaller the planned application amount, the shallower the dimension or the formation density becomes lower. Item 4. The letterpress for coating according to Item 1. A plate cylinder having a coating relief plate on the outer periphery, and anilox supplying a coating solution to the coating relief plate,
The coating relief plate has a convex portion on the surface, and receives the supply of the coating liquid from the anilox to the tip surface of the convex portion, and applies the tip surface to the substrate to be coated so as to be applied to the substrate to be coated. In a coating apparatus for applying a liquid,
Forming a plurality of recesses into which the coating liquid supplied from the anilox can flow into the tip surface of the convex part,
In the case where the coating concentration of the coating liquid is made different for each part of the substrate to be coated, at least one of the dimension or the forming density of the recess is made different according to the planned coating concentration of each part. .

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