Method for producing a decorated profile body

Abstract

The invention relates to a method for producing a decorated profile body (1), said method comprising the steps of: providing a substrate (2); providing a decorative base (4); and applying a decorative enhancement (6) in the form of ink droplets (100) onto the decorative base (4, 5) using a digital printing process. According to the invention, the decorative base (4) is in the form of an adhesion-promoting primer layer between the substrate (2) and the decorative enhancement (6), and at the same time forms a coloured base coat of the decorated profile body (1). The invention also relates to a correspondingly decorated profile body (1).

Description

[0001] Method for producing a decorated profile body

[0002] The invention relates to a method for producing a decorated profile body comprising the steps:

[0003] - Providing a substrate;

[0004] - Providing a decorative base and

[0005] - Application of a decorative finish in the form of ink droplets onto the decorative base using digital printing.

[0006] Such a process is known, for example, from EP 2 247 451 B1. This document deals with the production of digitally printed polymer-based edgebands for the narrow-side coating of furniture panels. Here, a primer layer is first applied to a polymeric, e.g., extruded substrate made of PP. This primer layer serves as an adhesion promoter between the non-polar polymer material and the print with polar properties. The decorative base is then applied to the primer layer as a color layer. This color layer provides the edgeband with basic color and serves as the base layer for the digital printing.

[0007] Digitally printed edgebands often also feature a base layer for digital (usually CMYK) printing, as well as a digital printing primer layer. The solvent-based base layer is necessary to brighten the plastic carrier layer (usually PP), and the generally transparent primer layer is required to control the digital print dot formation. When using conventional printing techniques, the solvent-based base layer plus DD primer is applied once or twice, depending on the opacity, via roller printing units in the indirect gravure printing process. The base layer is dried with hot air, depending on the required opacity. The primer layer is usually curable using UV radiation. In summary, the current technology involves both a decorative primer and the separate application of a primer layer.The large number of printing units results in significant cleaning, setup, and adjustment times when switching from one print job to the next, which involves a different design. This creates the risk of malfunctions in the individual printing units. Furthermore, the thickening or manual dilution of the solvent-based ink by the operator can lead to undesirable process fluctuations. Furthermore, the combination of solvent and UV primer can lead to undesirable fluctuations in production quality over time.

[0008] Against this background, the object of the invention is to provide a method with the features described above, which provides a simplified and at the same time reliable method for producing a digitally printed profile body.

[0009] According to the invention, this object is achieved in that the decorative base is formed as an adhesion-promoting primer layer between the substrate and the decorative finish, while simultaneously forming a colored primer for the decorated profile body. The invention is based on the finding that the decorative base can both ensure optimal print dot formation for digital printing and simultaneously provide a basic color for the decorated profile body. This can significantly reduce setup and adjustment times when changing decor. Furthermore, printing units can be eliminated, thus lowering the investment costs of corresponding continuously operated systems. The teaching of the invention also makes it possible to shorten the required line length for such systems, since fewer process steps need to be performed. The production-related printing process is more stable and therefore more precise.This improves overall production quality while simultaneously reducing operating costs for e.g. energy, etc. and also offers ecological advantages, since preferably no solvents need to be used. It is within the scope of the invention that, when preparing the decorative base, a colorant is added to a digital printing primer, which ensures the simultaneous color priming by the decorative base according to the invention. The decorative base according to the invention establishes adhesion to the substrate and allows embedding of ink droplets therein. The layer thickness of the decorative base is expediently 2 to 30 μm, in particular 5 to 25 μm, e.g. 10 to 20 μm. The decorative base can contain, in particular crosslinkable, acrylates, e.g. PU acrylates and / or polyester acrylates and / or epoxy acrylates, in particular in the form of acrylate monomers and acrylate oligomers, e.g. with a weight fraction of at least 10%, in particular at least 20% or at least 30%, e.g.at least 50%. The acrylate content is expediently a maximum of 90% by weight, e.g. a maximum of 80% by weight. The decorative base can be designed as a one-component (1K) coating or alternatively as a two-component (2K) coating. In the latter case, the materials mentioned can be used as the first component. Isocyanate-based crosslinkers can be used for the second component. The 2K application is particularly suitable when there are high demands on moisture resistance (e.g. for kitchen or bathroom furniture) and for improving adhesion on critical substrates (possibly with polyolefin plastics as the substrate material). The pigment content in the decorative base can be at least 5% by weight, e.g. at least 10 or at least 15% by weight, e.g. at least 20% by weight, whereby titanium dioxide, for example, can be used as the pigment.The decorative base is preferably constructed in a single layer, although this does not preclude a multi-layer structure. Overall, the inventive teaching simplifies the layered structure of the profile body.

[0010] The decorative base is expediently applied to the entire substrate, so that the decorative base, together with the decorative finish, forms the decoration of the decorated profile body. This means, in particular, that the appearance of the decoration is determined solely by the decorative base and the decorative finish. Alternatively, it is also within the scope of the invention to apply the decorative base only to certain areas of the substrate. In this case, the appearance of the substrate also expediently contributes to the overall appearance of the decorated profile body.

[0011] The decorative base can be applied, e.g., as a layer of paint, to the already produced substrate. Within the scope of the invention, it is fundamentally possible for the decorative base to be applied by roller application, e.g., using at least one anilox roller. However, it is also within the scope of the invention for the decorative base to be coextruded with the substrate, and in this context, the decorative base can, in particular, be formed as a polymer layer.

[0012] The surface tension of the decorative base is expediently adjusted by irradiation before the application of the decorative finish, in particular in the form of UV irradiation, e.g. using LED lights. The UV irradiation can be carried out with a wavelength of 200 to 450 nm, e.g. 300 to 450 nm or 350 to 450 nm, in particular 380 to 420 nm. This ensures optimal print dot formation in the digital printing, i.e. the ink droplets applied in digital printing stand cleanly on the decorative base and can harden in this state, thus ensuring a clean printed image. According to a preferred embodiment of the invention, UV irradiation and thus deep hardening of the decorative base is carried out first in order to improve its bond to the substrate. The decorative base is then UV irradiated with at least one, preferably two, UV emitters (e.g.[Hg]) in order to harden it and to adjust its surface tension for the pressure point formation.

[0013] To provide the colored primer, the decorative base can contain color pigments. According to a preferred embodiment of the invention, the decorative base is colored white to provide the colored primer for the decorated profile body. The color used here can be, for example, RAL 9003, RAL 9010, or RAL 9016. Titanium dioxide, in particular, can be used as the color pigment. As color pigments, alternatives or additions to white pigments such as titanium dioxide (Color Index (CI): PW 6) but also black pigments such as lamp black (CI: PBk 7) and / or colored pigments such as yellow (CI: PY 42, PY 83, PY 110, PY 128, PY 138, PY 184) and / or orange (CI: PO 64, PO 73) and / or brown (CI: PBr 24) and / or red (CI: PR 48:4, PR 101, PR 122, PR 149, PR 254) and / or blue (CI: PB 15:3, PB 29) and / or green (PG 7) can be used.It goes without saying that one of the aforementioned pigments can be used as the color pigment, or a combination of at least two of the aforementioned pigments.

[0014] Conveniently, only the decorative base is applied as an intermediate layer between the substrate and the decorative finish. The decorative finish can be provided with a transparent, especially translucent, lacquer layer, preferably forming the outer surface of the decorated profile body. This lacquer layer is preferably cured by UV radiation after application to the decorative finish, e.g., using appropriate LED lights. The lacquer layer can be translucent, e.g., to achieve a desired matte appearance. However, it is also within the scope of the invention, in particular, for the lacquer layer to be transparent.

[0015] The substrate is expediently made of a polymeric material, in particular PP, ABS, PMMA, or PVC. The substrate can be formed, in particular, as an extruded or calendered profile, preferably as an edgeband or wall connection profile, or as a film, for example, with a layer thickness of less than 0.5 mm, in particular less than 0.3 mm.

[0016] The invention also relates to a decorated profile body with the described structure according to the invention. The invention is explained in detail below with reference to a drawing that represents only one exemplary embodiment. The drawings show schematically:

[0017] Fig. 1 shows a layer structure of a decorated profile body according to the prior art, Fig. 2 shows a structure of a decorated profile body according to the invention and

[0018] Fig. 3 shows a method for producing the profile body shown in Fig. 2.

[0019] Fig. 1 shows a layer structure of a decorated profile body 10, as described in the prior art according to EP 2 247451 B1. The profile body 10 comprises as a base a polymeric substrate 20 with a bottom side 210 and a top side 220. A primer layer 30 is applied to the top side 220 of this substrate 20, which primer layer ensures good chemical bonding of a universal base layer 40 arranged thereover to the substrate 20. An individual base layer 50 is applied to the universal base layer 40, which together with the universal base layer 40 forms a decorative base of the profile body 20. The individual base layer 50 has depressions 510 and elevations 520. A decorative finish 60 is introduced into the depressions 510 using a digital printing process, which decorative finish 60, together with the decorative base, forms the decoration of the profile body 10. A protective clear coat layer 70 is provided on the outside.

[0020] In the production of a decorated profile body 1 according to the invention as shown in Fig. 2, a substrate 2 and a decorative base 4 are also provided. A decorative finish 6 is applied to the decorative base 4 in the form of ink droplets 100 (see Fig. 3) using a digital printing process. According to the invention, the decorative base 4 is now formed as an adhesion-promoting primer layer between the substrate 2 and the decorative finish 6 and, at the same time, forms a colored primer for the decorated profile body 1. The decorative base 4 was applied to the entire surface of the substrate 2, so that the decorative base 4, together with the decorative finish 6, forms the decoration of the decorated profile body 1. Alternatively, however, only partially covering the substrate 2 with the decorative base 4 is also within the scope of the invention (not shown). In the exemplary embodiment, the decorative base 4 was applied to the already produced polymeric substrate 2, which, for example,made of PP, ABS, PMMA, or PVC. The surface tension of the decorative base 4 was specifically adjusted prior to the application of the decorative finish 6 by means of UV irradiation with LED lights. This ensures optimal print dot formation for the digital printing, i.e., the ink droplets 100 of the decorative finish 6 applied during digital printing rest neatly on the decorative base 4 and can harden in this state, ensuring a clean print image. In this example, the UV irradiation occurs at a wavelength of 395 nm.

[0021] The decorative base 6 was colored white to prime the decorated profile body 1, e.g., the decorative base has the color RAL 9016 ("traffic white"). It can also be seen that only the decorative base 4 is applied as an intermediate layer between the substrate 2 and the decorative finish 6. Furthermore, the decorative finish 6 was provided with a transparent, in particular translucent, lacquer layer 7 forming the outer surface of the decorated profile body. In the exemplary embodiment, this lacquer layer was cured by UV radiation after being applied to the decorative finish 6. The substrate 2 according to Fig. 2 is designed as an extruded or calendered edge band profile for coating the narrow sides of a furniture panel. The layer thicknesses of the individual layers 2, 4 and 7 are, for example, each: substrate 2: 0.3 - 5 mm, in particular 0.3 to 2 mm, decorative base: 2 to 30 pm, in particular 5 to 20 pm, lacquer layer 5 to 25 pm, in particular 10 to 20 pm.

[0022] Fig. 3 shows a continuous process for producing a decorated profile body 1 according to Fig. 2. It can be seen that the decorative base 4 is applied to the web-shaped polymeric substrate 2, which moves continuously at the speed v in the web direction, using a conventional roller arrangement 50. The applied decorative base 4 is cured by means of an LED UV lamp arrangement 300, thereby specifically adjusting the surface tension of the still liquid decorative base 4. The lamp arrangement consists of a UV lamp (395 nm wavelength) for the deep curing of the decorative base 4, which ensures a good bond between the decorative base 4 and the substrate 2, and at least one (e.g. two) downstream UV lamps for the general curing of the decorative base 4 and the control of the printing dot formation. Then, by means of digital print heads 200, e.g.In CMYK printing, ink droplets 100 are applied to the decorative base 4, forming the decorative finish 6. Due to the specifically adjusted surface tension of the decorative base 4, a very clean application of the decorative finish is possible using the ink droplets 100. After application, the ink droplets 100 can be cured, for example, using UV radiation (not shown in detail). The decorative base 4, as already described, is designed as an adhesion-promoting primer layer and simultaneously forms a colored base coat for the decorated profile body 1.

[0023] For this purpose, color particles are added to the liquid 5, which is applied to the substrate 2 to form the decorative base. The decorative finish 6 is then provided with a clear coat 7, which is also applied using a roller arrangement 50'. After being applied to the decorative finish 6, the corresponding clear coat liquid 5' is cured using a UV lamp 400. It is within the scope of the invention that the decorative base 4 and / or the clear coat 7 can also be applied using digital printing as an alternative to roller application.

[0024] Patent claims

Claims

Patent claims 1. A method for producing a decorated profile body (1) comprising the steps: - providing a substrate (2); - Providing a decorative base (4); - applying a decorative finish (6) in the form of ink droplets (100) to the decorative base (4) using a digital printing process, characterized in that the decorative base (4) is formed as an adhesion-promoting primer layer between the substrate (2) and the decorative finish (6) and at the same time forms a colored primer of the decorated profile body (1).

2. Method according to claim 1, characterized in that the decorative base (4) contains, preferably crosslinkable, acrylates.

3. Method according to claim 1 or 2, characterized in that the decorative base (4) is applied to the substrate (2) in a fully covering manner, so that the decorative base (4) together with the decorative finish (6) forms the decoration of the decorated profile body (1).

4. Method according to one of claims 1 to 3, characterized in that the decorative base (4) is applied to the already produced substrate (2) or is coextruded with the substrate (2).

5. Method according to one of claims 1 to 4, characterized in that the surface tension of the decorative base (2) is adjusted by means of irradiation, in particular in the form of UV irradiation, before the application of the decorative finish (6).

6. The method according to claim 5, characterized in that the UV irradiation takes place with a wavelength of 200 to 450 nm, e.g. 350 to 450 nm, in particular 380 to 420 nm.

7. Method according to one of claims 1 to 6, characterized in that the decorative base (6) is colored white for the colored priming of the decorated profile body (1).

8. Method according to one of claims 1 to 7, characterized in that only the decorative base (4) is applied as an intermediate layer between the substrate (2) and the decorative finish (6).

9. Method according to one of claims 1 to 8, characterized in that the decorative finish (6) is provided with a transparent lacquer layer (7), preferably forming the outer surface of the decorated profile body (1), which is preferably cured by means of UV irradiation after its application to the decorative finish (6).

10. Method according to one of claims 1 to 9, characterized in that the substrate (2) is made of a polymeric material, in particular PP, ABS, PMMA or PVC.

11. Method according to one of claims 1 to 10, characterized in that the substrate (2) is formed as an extruded or calendered profile, preferably as an edge band or wall connection profile, or as a film, for example with a layer thickness of less than 0.5 mm, in particular less than 0.3 mm.

12. Decorated profile body (1) with - a substrate (2), - a decorative base (4) and - a decorative finish (6) applied to the decorative base (4), characterized in that the decorative base (4) is designed as an adhesion-promoting primer layer between the substrate (2) and the decorative finish (6) and at the same time forms a colored primer of the decorated profile body (1).

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