EP3656566A1 - Method for printing longitudinal profile strips and profile strips - Google Patents

Abstract

Method for printing elongated profiled strips (100), in particular skirting boards, with a pattern (4), in particular a wood grain decor, wherein a haptic ink (3) is first applied to at least one of a haptic ink (3) by means of digital direct printing by means of a printhead arrangement (10) a partial area of a basic profile (1) of the profile strip (100) which is moved relative to the print head arrangement (10) is printed, and that a colored pattern (4) is then correctly positioned on the previously three-dimensionally structured surface by means of a further print head arrangement (12), also by means of digital direct printing is printed on.

Description

The invention relates to a method for printing elongated profile strips, in particular skirting boards, with a pattern, in particular a wood grain decor, whereby to form a three-dimensionally structured surface first by means of digital direct printing through a printhead arrangement, a haptic ink on at least a portion of a basic profile moved relative to the printhead arrangement is printed on the profile strip, and that a colored pattern is subsequently printed in the correct position on the previously three-dimensionally structured surface by means of a further printhead arrangement, also by means of digital direct printing.

In addition, the invention relates to a profile strip, in particular a skirting board, with a printed three-dimensionally structured pattern.

It is already known to print a pattern, in particular with a wood grain decor, on profile strips, in particular skirting boards, such as are used in the case of flooring on the edges ( AT 508 572 B1 ). In this prior art, the pattern is first printed on an application roller and then indirectly on the profile bar.

Out WO 2013/161846 A1 is known to print flat surfaces with haptic ink and then to print a pattern (e.g. a wood grain decor) with the aim of achieving a more realistic look. When printing profile strips, in contrast to flat workpieces such as panels for floors, there is the problem that the profile strips have spatially differently oriented partial areas, which are either sharp-edged or adjoin one another via a curved surface.

The object of the invention is to provide a method for printing profile strips, in which patterns, in particular wood grain reproductions, can be applied with high imaging accuracy and with a realistic appearance.
According to the invention, this is solved by a method according to the feature of claim 1.

In the method according to the invention, not only is a colored pattern applied, but also a three-dimensional surface structure is formed by digital direct printing. This enables a realistic appearance to be achieved, in particular the reproduction of wood that has natural elevations and depressions, i.e. a 3D structure. In order to print all the surfaces of the profile strip with a three-dimensional surface structure and / or a colored pattern, it is provided that the haptic ink and / or the colored pattern is printed on parts of the profile strip which are spatially differently oriented in such a way that the different printing regions are partially in an overlap zone overlap. These overlap zones generally lie along a longitudinal edge of the profile strip or along a transition from a flat area to a curved area.

By overlapping it can be ensured that when using specially aligned printheads no empty space is left for the individual partial areas, which is particularly important if the background - as preferably provided - is formed by a white haptic ink. Through the use of several separate, preferably swiveling printheads and the idea of overlapping adjacent print areas with different orientations, a consistently clean print image can also be achieved on the profile strips ("around the corner").

Of course, the position of the colored pattern must lie exactly in the correct position in relation to the three-dimensional haptic ink underneath. This can be achieved by printing both the haptic ink and the colored pattern with digital direct printing, i.e. without transfer foils or indirectly printed application rollers. For digital direct printing, an inkjet or laser printing process is particularly suitable, which apply the color or ink to the workpiece, in particular the profile strip, directly from print heads without contact. Although application in two different printing processes is also conceivable and possible, it is cheaper to apply the printing with the haptic ink on the one hand and with the colored pattern on the other in one and the same printing process, i.e. in one pass, driven by a transport device that uses one electronic control device is synchronized with the print heads.

Printing in one pass allows higher production speeds on the one hand and also enables the relative alignment, i.e. the correct position between haptic ink and colored pattern, to be realized.

The workpiece (base profile of the profile strip) is preferably driven and the print heads are essentially stationary during operation, at least as far as the alignment in the transport direction / longitudinal direction of the profile strip is concerned.

In principle, however, it would also be possible to move the printheads in the longitudinal direction, since it is ultimately a question of the relative movement of the printheads to the workpiece (profile strip).

The invention also relates to a profile strip, preferably produced using the method described above. The profile strip according to the invention is characterized by the features of claim 12.

Further advantages and details of the invention are explained in more detail with reference to the following description of the figures.

Fig. 1a

ein Grundprofil des Ausführungsbeispiels einer erfindungsgemäßen Profilleiste,

Fig. 1b

dieses Grundprofil mit einer aufgebrachten Grundierung.

Fig. 1c

die Profilleiste mit einer auf die Grundierung aufgebrachten haptischen Tinte,

Fig. 1d

eine Profilleiste nach einem weiteren Arbeitsschritt, nämlich dem lagerichtigen Aufbringen eines farbigen Musters auf die dreidimensional strukturierte haptische Tinte.

Fig. 1e

die fertige Profilleiste nach dem Aufbringen einer dünnen Klarlackschickt,

Fig. 2

eine schematische Ansicht einer Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens anhand eines einfach dargestellten Ausführungsbeispiels,

Fig. 3

ein Ausführungsbeispiel einer Druckkopfanordnung zur Aufbringung eines farbigen Musters mit schwenkbaren Druckköpfen,

Fig. 4

in einer schematischen, perspektivischen Darstellung einer Profilleiste das Aufbringen eines farbigen Musters (hier streifenförmig) auf räumlich unterschiedlich ausgerichtete Teilbereiche der Profilleiste.

It shows:

Fig. 1a

a basic profile of the embodiment of a profile strip according to the invention,

Fig. 1b

this basic profile with an applied primer.

Fig. 1c

the profile strip with a haptic ink applied to the primer,

Fig. 1d

a profile bar after a further step, namely the correct application of a colored pattern to the three-dimensionally structured haptic ink.

Fig. 1e

sends the finished profile strip after applying a thin clear coat,

Fig. 2

2 shows a schematic view of a device for carrying out the method according to the invention using a simply illustrated exemplary embodiment,

Fig. 3

an embodiment of a printhead arrangement for applying a colored pattern with pivotable printheads,

Fig. 4

in a schematic, perspective representation of a profile strip, the application of a colored pattern (here strip-like) to spatially differently oriented partial areas of the profile strip.

This in Figure 1a illustrated basic profile 1 of a profile strip 100 has, for example, the dimensions of 16 x 60 mm. The basic profile 1 can consist of finger-jointed spruce wood, but also of any other material, in particular wood-based material, of plastic or a metal. Typical for basic profiles 1 is the fact that they have a front side 1a and a top side 1b, which are usually both to be printed, whereby Between the two flat sides 1a and 1b there is a curved surface 1c which is also to be printed in such a way that the surfaces 1a, 1b, 1c are printed continuously. In contrast to flat panels, such as those used for floors, it is necessary to print on the sub-areas 1a, 1b, 1c of the profile strip which have different spatial orientations. The rear side 1d is also profiled, but this is not critical since it is not printed on.

Providing the base profile 1 of the profile strip 100 with a primer 2, which has the same layer thickness everywhere, is relatively simple. This can be done either inline in a printing process above the transport device described later, or outside of an inline printing process. The purpose of the primer 2 is to achieve good adhesion of the haptic ink 3 applied later to the basic profile 1. For this purpose, it is also possible to sand the primer 2. Basically, water or UV lacquers (i.e. lacquers that harden under the influence of UV light) can be used. But other primers 2 are also conceivable and possible.

According to Figure 1c a haptic ink 3 is now printed on the primer 2, to be precise on the flat partial area 1a and 1b, and on the curved transition area (longitudinal edge) 1c. The haptic ink 3 then forms a three-dimensionally structured surface according to the invention, which simulates a wood grain in the present example. This makes it possible to create a realistic image of natural wood. Of course, not only wood designs can be "imitated", but also other three-dimensional surface structures.

The three-dimensionally structured haptic ink 3 has depressions 3a and elevations 3b. Overall, it is preferably provided that the thickness of the printed haptic ink 3 is at least in regions over 100 μm, preferably over 200 μm.

The variation in the thickness, that is to say the difference between the height of the depression 3a and the elevation 3b, is preferably more than 100 μm, preferably more than 200 μm, distributed over the surface in order to achieve a realistic 3D image.

According to Figure 1e a colored pattern is now printed in the correct position on this three-dimensionally structured surface according to the method according to the invention. This pattern bears the reference number 4. Figure 1 shows a (finished) profile strip 100.

The printed colored pattern 4 is adapted to the underlying haptic ink 3 with its 3D structure. This can be done by printing only partial areas 4a and leaving out partial areas 4b. Then the haptic ink 3 shines through with its color in these partial areas 4b. This is especially possible if it has a basic color that differs from the white color. However, it is preferably provided that the printing with the colored pattern 4 extends over the entire area to be printed, the different areas of the 3D structure (in particular elevations on the one hand and depressions on the other) being simply printed with different colors, but overall the layer thickness the color of the colored pattern 4 runs essentially the same everywhere on the three-dimensionally structured surface of the haptic ink 3.

According to a preferred embodiment, it is provided that a continuous clear lacquer layer 5 is finally applied over the colored pattern 4 in order to protect the underlying design. This clear lacquer layer should not be too thick so as not to cover up the three-dimensional feel previously produced.

An exemplary embodiment of a device for carrying out the method according to the invention which is shown in simplified form is shown in Figure 2 shown. The reference numeral 6 generally represents a transport device which The task is to hold the basic profile 1 of the profile bar 100 lying thereon and to move it in the transport direction 7, which coincides with the longitudinal direction of the profile bar 100. The holding device 8 is only shown schematically, it can work, for example, with negative pressure and can be both stationary and also moved. When holding devices 8 are also moved, clips can also be provided which hold the basic profile 1 exactly. In any case, the transport device 6 ensures that the basic profile 1 is moved through under the print head arrangements 10 and 12 described below. An electronic control device 9 controls, on the one hand, the transport and, on the other hand, the print head arrangements 10 and 12, and the curing and drying stations 11 and 13.

In the first printhead arrangement 10, a haptic ink 3 is applied to the basic profile 1 of the profile strip 100 in order to realize a three-dimensional surface structure. UV light is emitted in the curing station 11 in order to allow the UV-curable ink to cure at least partially before a colored pattern 4, in particular a wood decor, is applied in the correct position in the print head arrangement 12. This can also consist of a UV-curable paint, for which purpose a curing or drying station 13 is provided. As has been mentioned above, the printing of basic profiles 1 is a problem in particular because the area to be printed is generally subdivided into a number of subareas which are adjacent to one another but have different spatial orientations. At the in Figure 3 In the illustrated embodiment, a typical basic profile 1 is shown, which has a front side 1a, a cover side 1b and between them a curved transition area 1c. These three areas 1a, 1b, 1c are to be printed with a continuous pattern, in particular a wood grain decor.

To achieve this, a print head arrangement 12 can be used according to the method according to the invention, in which some print heads are arranged pivotably. This is indicated by an arrow 14. The The pivoting direction extends around an axis which is parallel to the transport direction 7, which coincides with the longitudinal direction of the profile strip 100. In general, a swivel range from 0 to 90 ° is sufficient. The pivoting can be carried out by one-time adjustment adapted to a particular type of profile strip, in such a way that the printing takes place as perpendicularly as possible to the area to be printed. In the case of a curved surface 1c, a compromise must be made here. In Figure 3 the curved surface 1c essentially undergoes a curvature of 90 °, which is why it will be advantageous for the print heads in the first (rear) area 12 ′ of the print head arrangement 12 to be approximately 45 ° in relation to the print heads in the second (front) area 12 ″ to arrange the print head assembly 12.

In principle, it would also be possible to change the swivel position of the print heads electronically controlled during the run in order to achieve an optimal print image. It will be cheaper and simpler, however, to adjust the swivel position of the print heads only to the profile type and then to adjust their alignment slightly during the printing process.

The problem of printing curved areas 1c by means of pivotable or differently aligned print heads can also be solved by printing overlapping zones between the individual areas to be printed. This is based on the Figure 4 explained in more detail.

In Figure 4 A simplified profile strip 100 is shown, which has a flat front side 1a, a flat cover side 1b and an intermediate curved region 1c along the longitudinal edge. The aim now is to print these three areas 1a, 1b, 1c exactly with a continuous decor, without leaving unprinted areas. For this purpose, swiveling printheads or other adjustable printheads can be used, as for example in Figure 3 are shown. In Figure 3 however, only two areas 12 ″ and 12 ′ are shown Figure 4 would consider a third area for printing on the cover side 1b. However, it is also possible for the first region 12 ′ of the printhead arrangement 12 to do this at once with the curved region 1c. In any case, it works Figure 4 from three areas of the printhead assemblies. First, the printheads in the first region 12 'of the printhead arrangement, which are oriented essentially perpendicular to the cover side 1b, could print on the region 14 which still extends in an overlap zone 14a into the region 1c, that is to say the subsequent curved region 1c of the longitudinal edge. The transition region 1c can then then be printed with at least one printhead pivoted essentially at 45 °. This pressure area is designated by 15 and has an overlap zone 15a and an overlap zone 15b. The overlap zone 15a is not absolutely necessary, it can be provided. However, it is also sufficient if the overlap zone 15a overlaps with the printing 15. The width of the overlap zone as a whole is designated B and is advantageously between 0.5 mm and 5 mm for profile strips 100.

When printing on the front side 1a, the idea is repeated with the printing beyond the transition edges 16, the print heads for the front side 1a are aligned essentially perpendicularly thereto and mainly print on the area 17, which in turn can have an overlap zone 17a.

Ultimately, by overlapping the print areas in differently oriented or curved partial areas of the basic profile 1 of the profile strip 100, a continuous, exact, clean print image is achieved without the layer underneath showing through. The print image is particularly accurate when the print head is aligned exactly perpendicular to the surface. In the case of curved surfaces, this is fundamentally not possible with a single print head or a single print head arrangement 12. But if two areas 12 'and 12 "of a printhead arrangement 12 interact with different swivel position, a good print image can be achieved even in an overlap area that is not exactly perpendicular to any of the print heads.

Controlled by suitable software, it can be achieved that the image, which does not hit the print heads exactly vertically, but hits curved surfaces, is distorted or corrected in such a way that it ultimately corresponds to the desired print image. In addition, this control via software can achieve that the ink application in the overlap zones (transition zones) is reduced compared to those zones where only a single application is carried out, so that - if these overlap zones are printed by two different print heads - not twice the ink application, but overall the correct paint application is done. In the overlap zones, two print heads each print reduced.

The above considerations apply in principle both to the application of the colored pattern and to the haptic ink 3, that is to say to the printhead arrangement 10 and 12.

As for the printhead assemblies 10 and 12 as a whole, as shown in Figs Figure 3 shown, consist of several individual print heads, which are designed for the application of different colors, in particular cyan, magenta, yellow and black.

The invention is not restricted to the exemplary embodiments shown. In particular, profiled strips with a different profile can also be used.

Reference symbol list:

1

Basic profile

1a

flat surface (front)

1b

flat surface (top side)

1c

curved surface

2nd

primer

3rd

haptic ink

4th

template

5

Clear coat

6

Transport device

7

Direction of transport

8th

Holding device

9

electronic control device

10th

Printhead arrangement (for haptic tine)

11

Hardening and drying station

12

Print head arrangement (for colored pattern)

12 '

first (rear) area

12 "

second (front) area

13

Hardening and drying station

14

Area

14a

Overlap zone

15

Oppression

15a

Overlap zone

15b

Overlap zone

B

Overlap width

16

Transition edges

17th

Area

17a

Overlap zone

100

Profile bar

Claims (15)

Method for printing elongated profiled strips (100), in particular skirting boards, with a pattern (4), in particular a wood grain decor, wherein a haptic ink (3) is first applied to at least one of a haptic ink (3) by means of digital direct printing by means of a printhead arrangement (10) a partial area of a basic profile (1) of the profile strip (100) which is moved relative to the print head arrangement (10) is printed, and that a colored pattern (4) is then correctly positioned on the previously three-dimensionally structured surface by means of a further print head arrangement (12), also by means of digital direct printing is printed, characterized in that the haptic ink (3) and / or the colored pattern (4) on spatially differently oriented partial areas of the profile strip (100) in different, partially overlapping in an overlap zone (14a, 15a, 15b, 17a) Pressure areas - preferably along an L. longitudinal edge of the profile strip (100) or along a transition from a flat (1a, 1b) to a curved area (1c) - are / will be printed overlapping. A method according to claim 1, characterized in that the printed portion of the profile bar (100) comprises a curved surface (1c) or a longitudinal edge of the profile bar (100). A method according to claim 1 or 2, characterized in that the printed portion of the profile strip (100) further comprises at least one flat surface (1a, 1b) of the profile strip (100), which adjoins the curved surface (1c) or the longitudinal edge. Method according to one of claims 1 to 3, characterized in that for printing spatially differently oriented partial areas the profile strip (100) within the printhead arrangement (10) for the haptic ink (3) spatially differently oriented, preferably pivotably mounted printheads are used. Method according to one of claims 1 to 4, characterized in that for printing on spatially differently oriented partial areas of the profile strip (100) within the printhead arrangement (12) for the colored pattern (4) spatially differently oriented, preferably pivotably mounted printheads are used. Method according to one of Claims 1 to 5, characterized in that the haptic ink (3) is printed one after the other on subregions of the profiled strip (100) with different spatial orientations by means of separate print heads. Method according to one of claims 1 to 6, characterized in that the colored pattern (4) is successively printed on partial regions of the profiled strip (100) which have different spatial orientations by means of separate print heads. Method according to one of claims 1 to 7, characterized in that the overlap zone (14a, 15a, 15b, 17a) has a width of 0.5 mm to 5 mm. Method according to one of Claims 1 to 8, characterized in that the profile strip (100) is applied with a primer (2) - preferably with the same layer thickness everywhere - before the haptic ink (3) is printed on. Method according to one of claims 1 to 9, characterized in that the profile strip (100) after printing on the colored pattern (4) is applied with a clear lacquer layer (5) - preferably with the same layer thickness everywhere. Method according to one of claims 1 to 10, characterized in that an ink jet printing and / or laser printing is used as digital direct printing. Profile strip (100), in particular skirting board, with a printed pattern (4), in particular produced by a method of claims 1 to 11, characterized in that the profile strip (100) has: - a basic profile (1), preferably made of a wooden material, metal or plastic, - A regionally printed haptic ink (3), which forms a three-dimensional, structured surface on the preferably substantially smooth surface of the base profile (1), and - A colored pattern (4) printed on the haptic ink (3) in the correct position, preferably with a uniform layer thickness. Profile strip according to claim 12, characterized in that the printed haptic ink (3) and / or the printed colored pattern (4) overlaps adjacent, spatially differently oriented partial areas in overlapping zones (14a, 15a, 15b, 17a). Profile strip according to one of claims 12 or 13, characterized in that the thickness of the printed haptic ink (3) is at least in regions over 100 µm, preferably over 200 µm. Profile strip according to one of claims 12 to 14, characterized in that the thickness of the printed haptic ink (3) Varies over the printed area by more than 100 µm, preferably by more than 200 µm.

Images