EP2411227A1

EP2411227A1 - Method for producing panels comprising printed sheets

Info

Publication number: EP2411227A1
Application number: EP10711539A
Authority: EP
Inventors: Udo Tünte; Frank Petersen
Original assignee: Huelsta Werke Huels GmbH and Co KG
Current assignee: Huelsta Werke Huels GmbH and Co KG; Flooring Industries Ltd SARL
Priority date: 2009-03-24
Filing date: 2010-02-05
Publication date: 2012-02-01
Also published as: ES2398772T3; EP2233286B1; WO2010108569A1; EP2233286A1; PL2233286T3

Abstract

The invention relates to a method for producing panels (21) for use on floors, walls or ceilings or for furniture, said panel (21) having a base body (19) which is moulded together with a resin-impregnated, patterned printed sheet (18) consisting of printed paper and/or an intermediate resin layer. The paper is printed with a repeating pattern by means of a printing unit and the printed paper is divided into a plurality of printed sheets (18) prior to being moulded. Before the pattern is printed, artwork for the pattern is prepared and displayed as an RGB colour model on a computer display device. According to the invention, the printing device comprises at least one digital printing unit and at least one rotogravure unit that has an engraved printing cylinder for the rotogravure printing of patterns. To print the pattern, either the digital printing unit or the rotogravure printing unit is used, depending on the quantity of the paper to be printed.

Description

METHOD FOR PRODUCING PLATE BODIES WITH PRINTED PRINTED BROKES

The invention relates to a method for the production of panel bodies for use in the floor, wall or ceiling area, such as panels, as well as in the furniture sector, wherein the plate body has a base body with a resinated, a decor comprising printed sheet of printed printing paper and / or a compressed intermediate resin layer, wherein the printing paper is printed with the repeated on the printing paper decor of a printing device and the printing paper is divided into a plurality of signatures before pressing, prepared before the printing of the decor decor template and on a display device of a computer device displayed in the RGB color system. Furthermore, the present invention relates to a device for carrying out the aforementioned method as well as a plate body for use in the floor, wall or De kenbereich, such as a panel, as well as in the furniture sector.

Methods for the production of plate bodies have been known for a long time. In the production of plate bodies of the aforementioned type a distinction is made according to the type of printing, whether the printing is done in Dekortiefdruckverfahren or in the digital printing process. In decorative gravure printing, where a variety of colors and color mixtures are used, the printing form usually consists of several printing cylinders, each with a copper coating with one or more copper layers. The cylinders can have a width of several meters and a diameter of up to 1.6 m. In the outer copper layer, the printed image is engraved in the form of so-called wells. The outer copper layer can otherwise be chrome plated for better durability. This is mainly used in higher circulation areas. The type of engraving in gravure usually allows an exact and reliable repeatability of the print result. For the production of large quantities of printed printing paper, the Dekortiefdruckverfahren is currently the only economical printing process.

After gravure printing printed with the decor printing paper is usually burred and then cut into sheets. Subsequently, the

BESTATIGUNGSKOPIE Press sheets with prepared primitives pressed. For this purpose, usually short-cycle presses (KT presses) are used.

The creation of multi-colored decors, for example, of certain wood grains, with certain colors is extremely complex and associated with a variety of steps. First of all, usually a decorative template is prepared. This refers to the creation of a decorative image. For example, certain grains with different shades as well as corresponding branches or the like are shown in a particular wood decor. After creating the template, it will be scanned. It then takes a revision of the template on the computer. Once the design template is created on the computer, a proof is usually produced and presented to the customer who ordered the template. If the proof is approved by the customer, individual color channels for the gravure printing device are extracted from the RGB data of the RGB color system. This is called separation. Usually, the decor consists of three mixed colors, so that three color channels are created. Each color channel is assigned to a printing cylinder.

Since the engraving of production gravure cylinders is associated with a considerable effort, it is customary in print shops to first create the gravure result on a laboratory scale. Smaller gravure printing machines with laboratory cylinders are used for this purpose. The laboratory cylinders are considerably smaller than the production cylinders. After engraving the laboratory cylinders, the desired colors are selected for the individual color channels. Subsequently, a gravure on laboratory scale. From the print result, a piece of printing paper is cut out as a laboratory sheet, which is then doctored. After curing, the laboratory printing sheet is pressed onto a base body of a plate body with a laboratory press. Subsequently, the decor of the laboratory-produced plate body is compared with the original decorative template. The individual colors for each cylinder are adjusted in further steps until the compressed decor of the template comes as close as possible.

Furthermore, it is often the case that the decor color does not correspond to the original. Therefore, the individual color channels and the related colors be revised. After a corresponding change, the laboratory cylinder is again engraved, deep-drawn in the laboratory, resin-coated and pressed. Subsequently, the laboratory result is compared again with the original template.

Furthermore, it also happens that the printed decor can not be approximated to the original only by Farbangeleichung. If the decor template can not be achieved with the laboratory cylinder set despite the most accurate color matching of the individual cylinders, it is usually necessary that the laboratory cylinder must be revised in their engraving.

Since the change of the laboratory cylinder and the setting of the correct color channels usually takes a few days and the customer of the decor template and the printer are not usually located in one place, the correct decorator's position means a considerable expenditure of time and money. It should be noted that it is not uncommon that a change in the color selection and / or the engraving of the laboratory cylinder between five to ten and sometimes even more than ten times takes place until the desired decor is created.

Once the right décor of the engraving and color selection on the laboratory scale has been found, the laboratory data regarding the engraving and the color selection in production data are revised. Subsequently, the engraving of the production cylinder. Particular problems in this context prepares in particular the adjustment of the color cylinder position determined for the three channels or three production cylinders. Then you can start production.

It can be seen that the effort to create a decor and set up a production gravure printing device is associated with considerable effort.

In addition, there is the disadvantage with decorative gravure printing that when the color mixture of a paint channel of a production cylinder is used up, or when the decor has to be re-produced, it is difficult to recreate the correct color tone. The colors of the individual color channels used in the usual decors are not standardized colors, but rather Color mixtures. Since it is important to have reproducible printing results, especially in the field of wood decors, a production break of a few hours often occurs in production until the correct color selection is presented again.

Furthermore, from the practice of the use of digital printing devices for digital printing of decors for plate body of the aforementioned type is known. The printing of printing paper with decors in digital printing for use with plate bodies in digital printing offers over the Dekortiefdruckverfahren the significant advantage that a decorator position can be done much easier and faster than the Dekortiefdruck. The disadvantage, however, is that even when using high-performance printers, the digital printing takes much longer than the Dekortiefdruck. For this reason, digital printing basically only comes into question if only a small amount of printing sheets for pressing with basic bodies for the production of plate bodies is needed.

The object of the present invention is now essentially to provide a production method and a device for producing plate bodies which is optimized with regard to its work processes, in particular with regard to the printing of the printing paper.

To achieve the above object, it is provided in a method of the type mentioned that the printing device comprises at least one digital printing device for digital printing and at least one engraved druckzylin- derautweisende intaglio printing for Dekortiefdruck and that for printing the decor depending on the amount of printing paper to be printed either the digital printing device or the gravure printing device is used. In the invention, it is thus so that the printing device for the production of the printed printing paper not only a printing device but two alternatively usable printing devices, namely on the one hand a digital printing device and on the other hand, a gravure printing device. Both facilities are production printing facilities on which the production of the printing paper for the production of printed signatures can take place. In this case, the selection of the respective printing device takes place as a function of the quantity of the printing paper to be printed. In the context of the present invention, it has been found that, in principle, when less than 1000 kg of printing paper is to be printed, in particular less than 700 kg and preferably less than 500 kg, the digital printing device is used for printing. For printing paper quantities that exceed the aforementioned amounts, it is expedient to resort to the gravure printing process.

Incidentally, in the context of the present invention, it is appropriate that the RGB data be converted by a computer device into CMYK data of the CMYK color system, wherein the printing cylinders of the gravure device are engraved on the basis of the CMYK data.

Unlike the known intaglio printing method, where the RGB data is divided into individual channels or laboratory cylinders, the color space consisting of three (mixed) colors, in the case of the invention in connection with the intaglio method, the CMYK method is used. Color system is resorted to. The RGB data are converted into CMYK data for this purpose. Since a color system other than the known Dekonniefdruckverfahren is used, it is in principle even possible to dispense with laboratory scale experiments and the use of a laboratory gravure device, although it is of course also possible in the invention according to the principle of the invention in CMYK- To engrave data converted RGB data into corresponding laboratory cylinders. In principle, however, this is not absolutely necessary.

As a result, the invention provides the very significant advantage that can be started much faster with the production in gravure after creating the decorative template on a display device of a computer in the RGB color system, if the amount to be printed is correspondingly large. The Farbausmusterung of the known method with three channels, are used over the three always reassembled mixed colors eliminated here completely. Ultimately, in the invention in each case, so regardless of whether it is printed in gravure printing or digital printing, resorted to a four-color printing, in which the color used in each case is constant or constant. It may happen that the brightest ink is printed first in the CMYK color system. Four printing cylinders are then used, in which the ink sequence Y (Yellow), C (Cyan), M (Magenta) and K (key black as color depth) is. The color sequence can also be K, C, M, Y, although other sequences are possible in principle.

Usually, a decor template, which is provided as a decoration for plate body, initially prepared manually and / or electronically. The term "preparation" can be understood as the result of all operations over which a decorative image can be made. This ranges from manual drawing, which is very expensive, to simply cutting out an existing image. For example, the decorative template can also be a corresponding section through a tree trunk. In order to be able to process the physically existing or prepared decorative template in electronic form, it is scanned.

An essential point of the processing is that during printing - regardless of whether it is printed in gravure printing or in digital printing - a so-called repeat results, so that a continuous, repeating decorative image is obtained. Accordingly, the data of the scanned decor template will be revised accordingly.

Before or after the reworking for the report, according to the method, a manual color pattern of the decor template displayed on the display device is made. The color pattern, which is ultimately made on the screen or the display device of the computer device, is based on the RGB color system. As soon as the desired decorative color has been reached, a proof of the decorative template displayed on the display device is created by means of the digital printing device. In the present case, the production digital printing device is used to print the proof. The proof is based on the CMYK color system whose color space is limited by the aforementioned four colors. Accordingly, the decoration color of the proof generally differs with the decor color displayed on the display unit via the RGB color system.

In order to achieve a rapid alignment between the decor color of the proof and the decor color displayed on the display device, an automatic calibration is performed. For this purpose, a calibration chart can be scanned, whereby the color data of the chart is automatically displayed with the RGB Color data are compared and then adjusted or adjusted accordingly via appropriate correction factors.

After calibration, it may be useful to create another chart, taking into account the calibrated CMYK data. This is then compared again with the decoration shown in the RGB color system on the display device. This process can then be repeated several times, if necessary, until the decorative color of the chart corresponds to the decorative color of the decoration displayed on the display device.

As a rule, the colors used in the CMYK color system are defined colors. Nevertheless, there may be differences in principle. Since in Dekortiefdruck a high color accuracy and authenticity is required especially for wood designs, it is particularly appropriate that the same Farbpig- elements and / or color compositions for the inks of the Proofdruckers and the printing ink of the printing cylinder of the gravure device are used. By the same color pigments and / or color compositions, even if the printing inks are different in terms of the application method in digital printing on the one hand and in gravure on the other hand, a high color fastness and repeatability of decorative colors guaranteed.

Furthermore, the present invention relates to a device for carrying out the aforementioned method, comprising a display device having a computer device for converting displayed in the RGB color RGBG RGB data in CMYK data of the CMYK color system and at least one digital printing device for digital printing and at least an engraved printing cylinder Dekortiefdruckeinrichtung Dekortiefdruck having printing device, wherein the computer device is coupled to both the digital printing device and with the gravure printing device or coupled. As a result, the device according to the invention thus ultimately has two production pressure devices, which are used depending on the application. As far as the gravure printing device is concerned, there is a difference from the prior art in that ultimately four engraved printing cylinders are provided, which are provided for gravure printing of the colors CMYK, wherein the ink sequence of the printing cylinder Y (yellow), C (cyan), M (magenta) and K (black as color depth). Since the device according to the invention has a digital printing device which is basically also suitable for printing a proof, it is possible to dispense with a separate proof digital printer. In any case, it is advantageous that the printing inks used in the digital printing device and the printing cylinders of the gravure printing device are identical, as far as the color pigments and / or color compositions of these colors are concerned.

Even if this may not be located at a single production site, the overall apparatus according to the invention also includes a holding device for holding the printed or printable paper, a cutting or cutting device for dividing or cutting the resinated printing paper into printed sheets and a Pressing device for pressing the signatures with the individual basic bodies.

Finally, the present invention also relates to plate body for use in the floor, wall or ceiling area, such as panels, as well as in the furniture sector, with a base body and a decor having printing sheet, which is pressed over a resin layer with the main body, wherein the pressure arc has been printed in Dekentiefdruckverfahren in CMYK color system. The plate body according to the invention thus differs from known plate bodies in the type of printing of the individual signatures, which, unlike in the art in Dekortiefdruckverfahren have been printed in the CMYK color system.

Other features, advantages and applications of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawings and the drawing itself. All described and / or illustrated features alone and in any combination form the subject of the present invention, regardless of their Summary in the claims or their dependency.

It shows

1 is a schematic representation of the method according to the invention, Fig. 2 is a schematic representation of a Dekortiefdruckeinrichtung invention and

Fig. 3 is a schematic representation of a plate body according to the invention.

In Fig. 1, the inventive method is shown schematically with the individual process steps. First, a decorative template is prepared in method step A. This can be done manually and / or electronically. The decor of the original is usually a specific wood grain.

After creating the template, it will be scanned in step B. It should be pointed out that in principle it is also possible for the original to be created electronically, that is to say on a computer, so that the scanning can be dispensed with.

Subsequently, in step C, the template is revised at a computer device.

In step D, the created design is then revised to the effect that a rapport results, with the result that the design is repeated almost constantly. It should be pointed out, however, that step D is not absolutely necessary, as there are decors that do not have to be printed indefinitely, so a repeat is not necessarily necessary.

After the design has been revised to a display device of the computer device and the design is displayed in the desired form by the display device in the RGB color system, in step E, the computer device converts the RGB data into CMYK data of the CMYK data. color system. During conversion, the RGB data is automatically converted by the computing device into CMYK data.

Subsequently, in step F, a proof, that is to say a color print, is produced on a digital printing device. This device is ultimately to a production digital printing device, ie one that is designed for production operation.

Since the design shown in the RGB color system usually deviates from the design shown in the CMYK color system, calibration is performed in step G. This is an automatic adjustment of the colors of the design shown on the display device according to the RGB color system and the proof printed design according to the CMYK color system. For this purpose, the design and / or the colors of a calibration chart can be scanned so that the individual colors can be compared directly via the computer device. Compensation factors for color correction are calculated. Based on the calibration result, the CMYK data is then adjusted accordingly. This process can be repeated several times.

In principle, since the CMYK color system is based on standardized colors, it is even possible for the conversion of the data in step E to take into account already determined or predetermined calibration factors which already reflect the deviations of the colors of the proof printed in the CMYK color system considered in advance with the colors shown in the RGB color system of the design shown on the display device.

Depending on the amount of printing paper to be printed, it is then decided whether printing on the digital printing device or the gravure printing device is used. In any case, in an amount of more than 1000 kg, the printing of the printing paper is done by gravure printing. For this purpose, in step H the engraving of the individual printing cylinders takes place on the basis of the CMYK data which has been calculated by the computer device taking into account the calibration factor (s).

After the engraving can be started with the printing of the printing paper in step I in the gravure printing method. It then results in a quasi-infinite printing paper with on the printing paper according repeating decoration. If, on the other hand, only a small amount of printing paper is to be printed, the printing takes place in the digital printing method by means of the digital printing device. This is then correspondingly coupled to the computer device, which takes over the CMYK data, which may have been calibrated. In this case, step H. is omitted.

After printing, the printed printing paper is doctored in step J. For this purpose, the usually located on a roll printed printing paper is unrolled, passes through a resin bath and is rolled up again after drying.

In step K, the printing paper is cut into a plurality of signatures. In any case, the printing paper is divided longitudinally, usually also transversely, so that the individual signatures result whose surface dimensions correspond to the surface dimensions of the base bodies of the plate bodies.

The basic bodies may be bodies made of wood or wood-based panels, in particular HDF, MDF, chipboard or OSB panels, but also gypsum plasterboard or gypsum fiberboard or also plastic panels. Other materials are readily possible. On the preparation of these plates will not be discussed in detail. Their preparation is basically known in the art.

In step L, the signatures are pressed with the basic bodies, for example in a KT pressing device. At the same time, a protective layer located above the printed sheet can be pressed with it.

FIG. 2 shows a Dekortiefdruckeinrichtung 1 of a device according to the invention. The gravure printing device 1 has four engraved printing cylinders 2, 3, 4, 5. Each printing cylinder 2, 3, 4, 5 is an ungravierter counter pressure cylinder 6, 7, 8, 9 assigned. Incidentally, each of the impression cylinders 2, 3, 4, 5 immersed in a paint container 10, 11, 12, 13 a. The color container is yellow (Y), the color container 11 is cyan (C), the color container 12 is magenta (M), and the color container is black (K). An unwinding device 14 is connected upstream of the printing cylinders 2, 3, 4, 5, and a take-up device 15 is connected downstream of the unwinding device 14 Unprinted printing paper 16 unwound, which is then printed in the gravure printing by the printing cylinder 2, 3, 4, 5. Subsequently, the printed printing paper 17 is wound up again.

As has already been stated above, the printed printing paper 17 is doctored after printing and then cut so that printed sheets 18 result, one of which is shown schematically in FIG. The printed sheet 18 is pressed with the base body 19 and a protective layer 20 to a plate body 21, which can then be used, for example, as panels in the floor, wall or ceiling area or as a furniture part in the furniture sector.

LIST OF REFERENCE NUMBERS

1 gravure device

2 pressure cylinders

3 pressure cylinders

4 impression cylinders

5 impression cylinders

6 impression cylinders

7 impression cylinder

8 impression cylinders

9 impression cylinders

10 paint containers

11 paint containers

12 paint tanks

13 paint containers

14 unwinding device

15 Aurwickeleinrichtung

16 unprinted printing paper

17 printed printing paper

18 printed sheet

19 basic body

20 protective layer

21 plate body

A preparation

B scanning

C revision

D rapport

E transformation

F color proofing

G calibration

H engraving

I pressure

J catching

K cutting

L presses

Claims

Claims:

1. A method for the production of plate bodies (21) for use in the floor, wall or ceiling area, such as panels, as well as in the furniture sector, wherein the plate body (21) has a base body (19) having a resinated, a decor having printed sheet (18) is pressed from printed printing paper and / or an intermediate resin layer, wherein the printing paper is printed with the decoration repeating many times on the printing paper by a printing device and the printing paper is divided into a large number of printed sheets (18) before being pressed, wherein before the printing of the decor prepares a decorative template and displayed on a display device of a computer device in the RGB color system,

characterized,

that the printing device comprises at least one digital printing device for digital printing and at least one engraved printing cylinder (2, 3, 4, 5) gravure printing device (1) for Dekortiefdruck and that for printing the decor depending on the amount of the printing paper to be printed either the digital printing device or the gravure device (1) is used.

2. The method according to claim 1, characterized in that at less than 1000 kg of printing paper to be printed, in particular less than 700 kg and preferably less than 500 kg, the digital printing device is used for printing.

3. Method according to claim 1 or 2, characterized in that the RGB data are converted by the computer device into CMYK data of the CMYK color system and that the printing cylinders (2, 3, 4, 5) of the gravure printing device (1) engraved on the basis of the converted CMYK data.

4. The method according to any one of the preceding claims, characterized in that the prepared decor template is scanned and that, preferably, the data of the scanned decor template for reworking be revised.

5. The method according to any one of the preceding claims, characterized in that a color pattern of the display displayed on the display device is made.

6. The method according to any one of the preceding claims, characterized in that a proof of the displayed on the display device decor is created by means of the digital printing device.

7. The method according to any one of the preceding claims, characterized in that the colors and / or the design of a calibration chart for the calibration of the computer device converted CMYK data are used.

8. The method according to any one of the preceding claims, characterized in that after calibration, another Kalibrschschart is created due to calibrated CMYK data.

9. The method according to any one of the preceding claims, characterized gekenη- characterized in that the same color pigments and / or color composition for the

Printing inks of the digital printing device and the printing cylinder (2, 3, 4, 5) of the gravure printing device.

10. Apparatus for carrying out the aforementioned method, comprising a display device having computer means for converting in

RGB color system displayed RGB data in CMYK data of the CMYK color system, with a at least one digital printing device for digital printing and at least one engraved printing cylinder (2, 3, 4, 5) gravure device (1) for Dekortiefdruck having printing device, wherein the computer device is coupled or coupled with both the digital printing device and with the engraver of the gravure printing device.

11. The device according to claim 10, characterized in that a Behar- Zungseinrichtung is provided for the bonding of the printed or printable printing paper.

12. The apparatus of claim 10 or 11, characterized in that a dividing device is provided for dividing the resinated printing paper in printing sheets.

13. Device according to one of claims 13 to 15, characterized in that a pressing device for pressing of printed sheets (18) is provided with basic bodies (19).

14. plate body (21) for use in the floor, wall or ceiling area, such as a panel, and in the furniture sector, with a base body (19) and a decor having printing sheet (18), which via a resin layer with the base body (19 ), wherein the printed sheet (18) has been printed by the Dekortiefdruckverfahren in CMYK color system.

15. Plate body according to claim 14, characterized in that on the printing sheet (18) a protective layer (20) is applied.