JP2009154037A - Coating method of sheet-like building material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method of a sheet-like building material which uses an aqueous ink to impart high image quality and can solve considerations such as ink feathering and ink dripping. <P>SOLUTION: This coating method of a sheet-like building material employs a coating unit 40 to fulfill the inkjet coating process, and the coating unit 40 is configured of a color ink head 70 equipped with an ink discharge nozzle 71 which discharges an aqueous color ink to the sheet-like building material 1 fed by a conveyor, a clear ink head 80 equipped with an ink discharge nozzle 81 for discharging a clear ink of ultraviolet curing type and an ultraviolet light 90 which cures the clear ink under exposure to ultraviolet rays output, arranged in that order. After discharging the clear ink onto the color ink impacting on the surface of the sheet-like building material to cover the latter, the ultraviolet light is shone on the clear ink to cure it. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for coating a plate-shaped building material, in which the surface of the plate-shaped building material is inkjet-coated.

Conventionally, various technologies for color printing on a recording medium by ink jet printing have been proposed. In recent years, ultraviolet curable ink that cures when irradiated with ultraviolet rays is used to prevent bleeding of the landed color ink. The thing which aimed at image quality improvement is known.
For example, Patent Document 1 below describes an ink jet printer that includes a recording head that ejects ultraviolet curable ink and an ultraviolet light (ultraviolet light source) for curing and fixing the ultraviolet curable ink that has landed on the recording medium. The irradiation condition of ultraviolet rays on the recording medium can be changed according to at least one of the color of the ink that is ejected and landed on the recording medium and the amount of the droplet per ink that is landed on the recording medium. The point comprised by is disclosed.
According to this, since the irradiation condition of the ultraviolet rays changes according to the color of the ink and the amount of droplets per ink landing on the recording medium, the diameter of the droplets cured and fixed on the recording medium becomes non-uniform. In addition, it is said that the ink can be prevented from being discolored due to bleeding and the image quality can be improved.

Also, in Patent Document 2 below, photocurable colored ink is ejected, and after the colored ink is cured by an ultraviolet light (light irradiation device), the photocurable transparent ink is ejected and the light irradiation device is used to clear the transparent ink. An ink jet recording apparatus that controls to cure the ink is disclosed.
According to this, since the arrangement of the light irradiation device is controlled so that the curing of the colored ink and the curing of the transparent ink are performed separately, it is possible to prevent the mixing of the colored ink and the transparent ink, It is said that an increase in dot diameter can be suppressed and high image quality can be achieved.
JP 2003-145725 A JP 2005-153507 A

However, it has been pointed out that ultraviolet curable inks are cured relatively instantaneously when irradiated with ultraviolet light from an ultraviolet light, so that the ejection stability is lacking. In order to prevent bleeding of ink as in the above-mentioned Patent Documents 1 and 2, when an ultraviolet light is provided in the vicinity of the ink head, not only the discharged ultraviolet curable ink is cured, but also the tip of the ink head It is conceivable that the ultraviolet curable ink adhering to the ink discharge port is also cured by being irradiated with ultraviolet rays, which causes clogging of the ink discharge port.
In addition, the ultraviolet curable ink used in References 1 and 2 can prevent ink bleeding, but it is difficult for ink droplets to mix. Therefore, each droplet is present independently, and is finer than water-based ink. It is said that it is unsuitable for making a proper expression.

By the way, in recent years, a printing technique based on the ink jet method as described above is used for painting a building material, and it has become known as a method for painting a building material. According to this, local pattern formation and pattern patterns can be easily painted, and ink droplets can be ejected in a non-contact state to the building material to be coated, so it is also beautifully painted even on somewhat uneven building materials It can be performed. In addition, since a plate is not required unlike conventional gravure printing, it has been attracting attention as being able to respond to a market demanding high-mix low-volume production.
However, when printing building materials, unlike printing media such as office or household paper, the problem is that the environment for painting is often bad, so problems specific to painting building materials have been pointed out. . For example, since it is not easy to turn the building material upside down and paint the lower surface after painting the surface of the building material, a coating device may be arranged below the building material and ink jet painting may be performed from below the building material.
In such a case, even if UV curing ink that cures quickly is used, absorption and drying on the painted surface of the building material are not in time, ink drops droop due to gravity drop, and ink adheres to the ink discharge ports of the ink head, There was a problem that obstructed continuous ink ejection.

  The present invention has been made in view of the above circumstances, and provides a coating method for a plate-shaped building material that solves the problems of ink bleeding and ink dripping while using water-based ink capable of improving image quality. It is aimed.

In order to achieve the above object, a method for painting a plate-like building material according to the present invention is a method for painting a plate-like building material to be inkjet-coated using a painting unit, and the painting unit has been transported with water-based color ink. A color ink head with an ink discharge port that discharges to a plate-shaped building material, a clear ink head with an ink discharge port that discharges UV-curable clear ink, and an ultraviolet light that outputs UV light and cures the clear ink are arranged in order. After the clear ink is ejected onto the color ink landed on the surface of the plate-shaped building material to cover the color ink, the ultraviolet light is irradiated to cure the clear ink. Features.
Further, in the method for painting a plate-shaped building material according to the present invention, the coating unit is disposed below the plate-shaped building material, and the bottom surface of the plate-shaped building material is downward and the ink discharge ports are directed upward. Thus, inkjet coating with the color ink head, the clear ink head, and ultraviolet irradiation with the ultraviolet light can be sequentially performed.
Furthermore, in the method for coating a plate-shaped building material according to the present invention, the coating unit is configured by arranging the color ink head, the clear ink head, and the ultraviolet light in order from the upstream side in the conveyance direction of the plate-shaped building material. The inkjet coating and the ultraviolet irradiation may be performed with the coating unit fixed.
In the method for coating a plate-shaped building material according to the present invention, the coating unit is configured by arranging the color ink head, the clear ink head, and the ultraviolet light in order in the width direction of the plate-shaped building material. Can reciprocate between the start and end points in the width direction to perform the ink jet coating and the ultraviolet irradiation.

According to the coating method of the plate-shaped building material according to claim 1, after covering the color ink by discharging the clear ink on the color ink landed on the surface of the plate-shaped building material, irradiating with ultraviolet light, Since the clear ink is cured, the color ink that has landed on the surface of the plate-shaped building material is in a state of being covered and solidified by the clear ink. Therefore, since there is no need to place a drying device in the vicinity of the ink head that discharges color ink, the ink discharge port is not clogged by drying, and smooth continuous discharge is possible. Further, by covering the color ink with the clear ink, it is possible to prevent bleeding of the color ink and to further improve the image quality by taking advantage of the characteristics of the original water-based color ink. Further, since the color ink can be an aqueous ink instead of an ultraviolet curable ink, the cost can be reduced.
According to the method for coating a plate-shaped building material according to claim 2, even if ink-jet coating is performed from below the plate-shaped building material, the color ink is covered and hardened by the clear ink, so that ink dripping is prevented. Can do. Therefore, the color ink ejected from below does not sag due to gravity drop, adheres to each ink ejection port, and does not hinder continuous ejection of color ink.
According to the coating method of the plate-shaped building material of Claim 3, inkjet coating and ultraviolet irradiation can be performed in the state which fixed the coating unit. Therefore, since the inkjet coating can be performed satisfactorily even if the conveying speed of the plate-shaped building material is high, it can contribute to the productivity improvement.
According to the method for coating a plate-shaped building material according to claim 4, the coating unit reciprocates between the starting point and the end point in the width direction of the plate-shaped building material being conveyed, and performs inkjet coating and ultraviolet irradiation. Can do. Therefore, painting can be performed in a state in which the number of installed color ink heads, clear ink heads, and ultraviolet light is small, and the capital investment cost can be reduced.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 (a) and 1 (b) are explanatory views for explaining an embodiment of a plate-shaped building material coating method according to the present invention. FIG. 1 (a) is a schematic plan view, and FIG. 1 (b). FIG. 4 is a diagram schematically showing the configuration of a painting unit. FIG. 2 is a view similar to FIG. 1, and is a view schematically showing the coating state of the surface of the plate-shaped building material. FIG. 3 is a block diagram illustrating an example of a coating apparatus that executes the plate-shaped building material coating method according to the embodiment. 4A and 4B are explanatory views for explaining another example of the embodiment, in which FIG. 4A is a schematic plan view, and FIG. 4B is a diagram schematically showing a configuration of a coating unit. FIG. 5 is an explanatory view for explaining another embodiment of the method for coating a plate-shaped building material according to the present invention, and is a schematic vertical sectional view of an essential part. In the figure, the pattern painted on the plate-shaped building material is made of wood grain, but is not limited to this.

In this embodiment, the plate-shaped building material 1 to be painted by the coating apparatus A has a substantially rectangular parallelepiped shape, and the base material used for the plate-shaped building material 1 is wood such as laminated wood, plywood, particle board, wood fiber board, etc. In addition to the system material, a resin material such as melanin resin or a plate material made of a metal material can be used.
The pretreatment method prior to inkjet coating is not particularly limited, but a white ink receiving layer (not shown) for fixing the ink discharged from the ink discharge port of the coating apparatus A may be formed. Good.

As shown in FIGS. 1A and 3, the coating apparatus A stores a CPU 20a for controlling each means, an operation means 20b for performing various operations, a control program, or pattern data of a wood grain pattern to be painted. It has a control unit 20 with means 20c.
The control unit 20 controls the discharge operation of the color ink head 70 and the clear ink head 80 which will be described later, and also performs on / off and control of the irradiation of the ultraviolet light 90.
The coating apparatus A includes a transport unit 60 that transports the placed base material 12 and a coating unit 40. The coating unit 40 includes a color ink head 70 on which color ink is mounted, a clear ink head 80 on which an ultraviolet curable clear ink is mounted, and an ultraviolet light 90 that outputs ultraviolet light.
The plate-shaped building material 1 to be coated is transported in the direction indicated by the arrow d by a transport means 60 such as a roller conveyor 2 configured on the base 3, and the transport means 60 discharges ink droplets by the coating unit 40. And interlocked control. Then, predetermined pattern data is applied to the surface 1a of the plate-shaped building material 1 by ejecting ink droplets of color ink from the color ink discharge port 71 of the color ink head 70 disposed above the painted surface of the plate-shaped building material 1. The pattern is applied based on The driving method of the color ink head 70 and the clear ink head 80 is not particularly limited, and a known method can be applied as appropriate, and examples thereof include a piezo method and a valve method.

In FIG. 1A, 30 is an apparatus main body provided adjacent to the base 3, 50 is connected to the apparatus main body 30, and the coating unit 40 (color ink head 70, clear ink head 80, ultraviolet light 90) is connected. It is a nozzle arm to support.
The color ink head 70 is equipped with water-based color ink in which a main agent is a water-based solvent and a dye is dissolved therein, and includes four ink nozzles 72 that eject the color ink. Each ink nozzle 72 contains color inks of different colors, and ink droplets of black, yellow, magenta, and cyan are ejected from the ink discharge ports 71, respectively. The ink droplets ejected from the ink ejection port 71 are landed on the surface 1a of the plate-shaped building material 1, and a desired pattern is expressed by a set of minute dots formed by the landed ink droplets.
The clear ink head 80 is composed of one ink nozzle 82 from which an ultraviolet curable clear ink is ejected. When the clear ink head 80 is irradiated with ultraviolet rays emitted from the ultraviolet light 90, transparent ink droplets that are cured are ejected.
The ultraviolet light 90 includes a light source that outputs ultraviolet light, is provided to cure the clear ink 80a discharged to the surface 1a of the plate-shaped building material 1, and is controlled by the control unit 20 (see FIG. 2).

Next, a method for coating the plate-shaped building material 1 will be described in detail with reference to FIGS.
As shown in FIG. 1B, the coating unit 40 is configured by arranging the color ink head 70, the clear ink head 80, and the ultraviolet light 90 in order from the upstream side in the transport direction (direction indicated by the arrow d) of the plate-shaped building material 1. ing.
First, when a detection sensor (not shown) or the like detects that the plate-shaped building material 1 that has been subjected to the pretreatment process as described above has arrived at a predetermined position by the transport means 60, it is stored in the storage means 20 c of the control unit 20. Based on the grain pattern data, color ink is ejected from the ink ejection port 71 of the color ink head 70. As a result, a high-quality wood grain pattern is formed on the surface 1a of the plate-shaped building material 1 using the aqueous color ink. Next, the clear ink 80a is ejected onto the color ink 70a that has landed on the surface 1a of the plate-shaped building material 1 (see FIG. 2). Then, the color ink 70a that has landed on the surface 1a of the plate-shaped building material 1 is covered with the clear ink 80a. Since the ultraviolet light 90 is irradiated in this state, the clear ink 80a is immediately cured. At this time, since the clear ink 80a does not contain a colorant, it is instantaneously cured by irradiation with ultraviolet rays. Further, since it is possible to prevent the dot diameter of the ink droplets that have landed on the surface 1a of the plate-shaped building material 1 from being widened, it is possible to further improve the image quality.
Then, after that, as a post-processing step, the upper surface is covered with a surface layer (not shown) made of a transparent urethane resin or the like, and dried to obtain a plate-shaped building material 1 that is inkjet-coated.
In addition, it does not specifically limit about a pre-processing process and a post-processing process, A well-known process is employ | adopted.

According to this, after the color ink 70a that has landed on the surface 1a of the plate-shaped building material 1 has landed, it is covered and solidified by the clear ink 80a that is ejected immediately. Therefore, there is no need to place a drying device in the vicinity of the color ink head 70 that discharges the color ink 70a, so that the ink discharge port 71 can be coated without being clogged by drying, and smooth continuous discharge is possible. . In addition, it is possible to prevent ink bleeding and improve the image quality by utilizing the characteristics of the original water-based ink. Further, since the color ink can be an aqueous ink, not an ultraviolet curable ink, the cost can be reduced.
And according to the said coating method, since the inkjet coating and ultraviolet irradiation can be performed in the state which fixed the coating unit 40, even if the conveyance speed of the plate-shaped building material 1 is high, inkjet coating can be performed favorably and production It can contribute to improvement of the property.

Next, FIG. 4 is an explanatory diagram for explaining another example of the embodiment, in which (a) is a schematic plan view and (b) is a diagram schematically showing the configuration of the coating unit 40.
In this example, the coating method is the same as that in the above-described example, except that the coating unit 40 is mounted on the carriage 10 and reciprocates in the width direction of the plate-shaped building material 1 to perform inkjet coating and ultraviolet irradiation.
As shown in the figure, the coating unit 40 is configured by arranging a color ink head 70, a clear ink head 80, and an ultraviolet light 90 in order in the width direction of the plate-shaped building material 1, and is mounted on the carriage 10.
The carriage 10 reciprocates between the start point S and the end point E in the width direction of the plate-shaped building material 1 (in the direction indicated by white arrows). In addition, the conveyance direction of the plate-shaped building material 1 is a d arrow direction similarly to the above-mentioned example.
Here, the carriage 10 reciprocates, but ink jet coating and ultraviolet irradiation are performed while moving from the start point S to the end point E, and only moving while returning from the end point E to the start point S. Absent.
Therefore, first, after the clear ink 80a is ejected onto the color ink 70a landed on the surface 1a of the plate-shaped building material 1 to cover the color ink 70a, the ultraviolet light 90 is irradiated to cure the clear ink 80a. The same coating method as in the example can be performed.
Further, according to this, since the coating unit 40 mounted on the carriage 10 can be coated with a small number of color ink heads 70, clear ink heads 80, and ultraviolet light 90 installed, capital investment costs can be reduced. Can be reduced.

FIG. 5 is an explanatory view for explaining another embodiment of the method for coating a plate-shaped building material according to the present invention, and is a schematic vertical sectional view of an essential part. Points common to the above-described embodiment are denoted by common reference numerals, and description of common points is omitted.
In this embodiment, the coating unit 40 is disposed below the plate-shaped building material 1, and the coating unit 40 is configured by arranging the color ink head 70, the clear ink head 80, and the ultraviolet light 90 in order from the upstream side in the transport direction. ing.
By configuring the coating unit 40 in this way, the plate-shaped building material 1 can be applied even when ink-jet coating is performed with the lower surface 1b of the plate-shaped building material 1 facing downward from the lower side of the ink discharge ports 71 and 81. The same coating method as in the above-described embodiment, in which clear ink is discharged onto the color ink landed on the lower surface 1b (lower surface) to cover the color ink and then irradiated with ultraviolet light 90 to cure the clear ink. Can be performed sequentially.
In order to perform inkjet coating without turning the plate-shaped building material 1 itself upside down, the base 3 is partially provided with an opening 3a, and the plate-shaped building material 1 conveyed by the conveying means passes through the opening 3a. Painting is done at the timing.
Here, the illustrated example shows the color ink head 70, the clear ink head 80, and the ultraviolet light 90 that are arranged obliquely. According to this, it is possible to make it difficult for ink mist generated when ejecting color ink and clear ink to adhere to the ink discharge ports 71 and 81.

According to this, even if ink-jet coating is performed from below the plate-shaped building material 1, the color ink is covered and hardened by the clear ink and cured, so that ink dripping can be prevented. Therefore, the color ink discharged from below does not sag due to gravity drop, adhere to the ink discharge ports 71 and 81, and does not prevent continuous discharge of color ink.
Here, the example in which the color ink head 70, the clear ink head 80, and the ultraviolet light 90 are respectively inclined and described has been described. However, the present invention is not limited to this example. It may be desirable for the ink discharge ports 71 and 81 to be parallel to the painted surface of the plate-shaped building material 1 (in this case, the lower surface 1b).

  The plate-shaped building material 1 coated with inkjet as described above can be used for exterior materials such as outer walls and fences, and interior materials such as doors, floors, stairs, railings, shelves, kitchen panels, and ceilings. Further, the coating apparatus A, the conveying means 60 and the like are not limited to those shown in the drawings.

(A) And (b) is explanatory drawing for demonstrating one Embodiment of the coating method of the plate-shaped building material which concerns on this invention, (a) is a schematic plan view, (b) is the structure of a coating unit. It is the figure shown typically. It is the same figure as FIG. 1, and is the figure which showed typically the coating state of the surface of a plate-shaped building material. It is a block diagram which shows an example of the coating device which performs the coating method of the plate-shaped building material which concerns on the embodiment. It is explanatory drawing for demonstrating the other example of the embodiment, (a) is a schematic plan view, (b) is the figure which showed typically the structure of the coating unit. It is explanatory drawing for demonstrating another embodiment of the coating method of the plate-shaped building material which concerns on this invention, and is a schematic principal part longitudinal cross-sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate-shaped building material 1a Surface 1b Bottom surface A Coating apparatus 40 Coating unit 70 Color ink head 71 Ink discharge port 80 Clear ink head 81 Ink discharge port 90 Ultraviolet light

Claims (4)

In the painting method of plate-shaped building materials to be inkjet-painted using the painting unit,
The coating unit includes a color ink head having an ink discharge port for discharging water-based color ink to a plate-shaped building material that has been transported, a clear ink head having an ink discharge port for discharging an ultraviolet curable clear ink, and an ultraviolet ray. Are arranged and arranged in order with UV light that cures clear ink.
A plate-like material characterized in that after the clear ink is ejected onto the color ink landed on the surface of the plate-like building material to cover the color ink, the ultraviolet light is irradiated to cure the clear ink. How to paint building materials. In claim 1,
The coating unit is arranged below the plate-shaped building material,
The color ink head, inkjet coating with the clear ink head, and ultraviolet irradiation with the ultraviolet light are sequentially performed with the lower surface of the plate-shaped building material facing downward and the ink discharge ports facing upward. How to paint plate-shaped building materials. In claim 1 or claim 2,
The coating unit is configured by arranging the color ink head, the clear ink head, and the ultraviolet light in order from the upstream side in the conveyance direction of the plate-shaped building material,
A method for coating a plate-shaped building material, wherein the inkjet coating and the ultraviolet irradiation are performed in a state where the coating unit is fixed. In claim 1 or claim 2,
The coating unit is configured by arranging the color ink head, the clear ink head, and the ultraviolet light in order in the width direction of the plate-shaped building material,
The said coating unit reciprocates between the start point and the end point of the said width direction, and performs the said inkjet coating and the said ultraviolet irradiation, The coating method of the plate-shaped building material characterized by the above-mentioned.

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