[0053]Figure 1a to 1c A first embodiment according to the invention is shown.
[0054]inFigure 1a The workpiece 1 is shown in a side view, which is here configured as a plate-shaped workpiece 1. The workpiece 1 contains solid wood or wood fibers at least in a partial area of the surface.
[0055]A covering 3 is applied to the upwardly facing surface of the workpiece 1. The covering 3 is applied in such a way that at least some parts of the surface of the workpiece 1 are covered by the covering 3. The result of this application isFigure 1b Shown in. The cover 3 is used for sealing on the surface of the workpiece 1 so that the area on the surface of the workpiece 1 where the cover 3 is applied is sealed. Therefore, the surface is covered for the next step, that is, part of the surface of the workpiece 1 is no longer exposed as before.
[0056]In another step, the liquid 4 is applied to the surface of the covered workpiece 1. The liquid 4 here only contacts the exposed (ie uncovered) area of the surface of the workpiece 1. However, the area of the surface of the workpiece 1 sealed by the cover 3 does not come into contact with the liquid 4. This result isFigure 1c Shown in.
[0057]In an alternative embodiment, the cover 3 does not provide complete coverage ("open holes") to the surface of the workpiece 1, so that the liquid 4 can partially penetrate in the covered position, but compared to the uncovered area , The amount of penetration is reduced.
[0058]The liquid 4 is designed here to visually change the surface of the workpiece 1 when in contact, in particular in interaction with solid wood or wood fibers on the surface. This interaction or visual change only occurs in the liquid action area 2, which extends from the area where the surface of the workpiece 1 is in contact with the liquid 4 to the interior of the workpiece 1. In this way, a visual change of the workpiece 1 can be achieved.
[0059]In an alternative embodiment, the interaction with the liquid 4 can also occur in other areas of the surface (not on the liquid action area 2), but the degree of interaction is relatively reduced compared to the area 2.
[0060]In a specific embodiment, the cover 3 also partially penetrates the workpiece 1.
[0061]Figure 2a to 2c Shows the implementation inFigure 1a to 1c Alternatives to the intermediate results shown in.
[0062]In the illustrated embodiment, the cover 3 is applied in the form of a droplet 3a, which is here identified by a dashed border. For example, this can be performed using digital printing technology (eg, digital print head 11). Therefore, it is possible to actively influence the droplet output, especially in terms of the output volume of the droplet 3a. The feature by covering the surface of the workpiece 1 is the high variability of the covering pattern. The cover 3 is designed as, for example, digitally printable ink or digitally printable lacquer.
[0063]Alternatively or additionally, the cover 3 can also be applied by a device that simulates printing technology, as inFigure 2b Shown in. For example, the cover 3 may be applied as ink or lacquer to the surface of the workpiece 1 by the application roller 12. The application roller 12 rolls on the surface of the workpiece 1 and leaves the cover 3 on the surface to cover the surface.
[0064]In short, the covering can therefore preferably be applied using printing technology equipment. Ideally, but not necessarily, digital printing technology equipment is used for more complex covering structures.
[0065]The liquid 4 can be applied, for example, over a large area or over the entire surface. Here atFigure 2c Illustrated therein is a pouring device 21 which produces a curtain formed by the liquid 4 through which the workpiece 1 covered by the cover 3 is transported and passed through. The pouring device 21 has a storage in which the liquid 4 is stored, and the liquid 4 is transported from the storage to the surface of the workpiece 1 by a pump or a transport roller as shown in the figure.
[0066]Another possible way of applying the liquid 4 (not shown) can be achieved by an immersion bath, in which the workpiece 1 is immersed at least with a covered surface.
[0067]In another embodiment (not shown), the liquid 4 is applied to the covered surface by a roller application method.
[0068]image 3 Shows a functional block diagram of the basic equipment for performing the method according to the present invention.
[0069]The figure shows a cover applying unit 10, which is configured to apply a cover 3 to a workpiece 1, such asFigure 1a to 2c Shown. To this end, the cover applying unit 10 has, for example,Figure 2a Digital print head 11 shown in orFigure 2b Application roller 12 shown in.
[0070]A liquid application unit 20 is provided downstream of the cover application unit 10, and the liquid application unit is configured to apply the liquid 4 to the surface of the work 1. To this end, the liquid application unit 20 has, for example, a pouring device 21 (Figure 2c Shown) or dip tank or roll application unit.
[0071]In addition, a fixing unit 40 is shown, which is provided between the cover applying unit 10 and the liquid applying unit 20. The fixing unit 40 is configured to dry the cover 3 before applying the liquid 4. To this end, the fixing unit 40 has, for example, a nozzle channel that allows hot air to flow onto the surface of the workpiece 1 or the covering 3. Alternatively or additionally, a heat source in the form of an infrared radiation source or a heat source in the form of a heating device can also be provided in order to dry the cover 3. The fixing unit 40 may also have a UV radiation source in order to cure the cover or fix the cover on the surface of the workpiece 1.
[0072]A pretreatment unit 50 is provided upstream of the cover applying unit 10, and the pretreatment unit is configured to pretreat the surface of the workpiece 1 for subsequent method steps. For example, a roughening roller or a polishing device may be provided here, which is configured to mechanically roughen the surface of the workpiece 1. Alternatively or in addition, an output device (Abgabevorrichtung) can also be provided here, which is configured to apply a roughening agent (for example, a chemical substance, such as an acid) to the surface of the workpiece 1. For example, in the interaction between the roughening agent and the wood fiber of the work piece 1, the latter changes accordingly, making the surface of the work piece 1 rougher, which is particularly beneficial to the absorption of the liquid 4.
[0073]Downstream of the liquid application unit 20 is a distribution unit 60 configured to distribute the liquid 4 on the surface of the workpiece 1 or introduce the liquid 4 into the surface of the workpiece 1. For example, the distribution unit 60 may perform this operation in a mechanical manner. For this purpose, the distribution unit 60 has, for example, a brush or brush roller, which comes into contact with the surface of the workpiece 1 and distributes or introduces the liquid 4 in a relative movement with the surface of the workpiece. The distribution unit 60 may also be configured in the form of a plurality of rotating brushes (having an axis perpendicular to the surface of the workpiece). Other alternative embodiments are also conceivable.
[0074]A post-processing unit 70 is provided downstream of the distribution unit 60, and the post-processing unit is configured to perform post-processing on the surface of the workpiece. For example, this can be performed mechanically. To this end, a grinding device may be provided, which is configured to remove the surface of the workpiece 1, in particular the covering 3 and/or the liquid 4 located on the surface. In this case, it is preferable to also remove the material of the workpiece 1 itself in order to expose the visual changes in the workpiece 1 that occur in deeper layers due to the liquid 4.
[0075]In addition, a coating unit 80 may also be provided, which is configured to coat the surface of the workpiece 1. For example, this can be done by applying lacquer on the entire surface, whereby the final sealing of the workpiece 1 is preferably performed, thereby protecting the visually changed surface of the workpiece 1. Therefore, the lacquer used for sealing is at least partially transparent. Acrylic-containing UV-curing paint, oil or wax can be used as sealing materials. Water-based coating systems and subsequent thermal drying are also conceivable.
[0076]All the units 10, 20, 30, 40, 50, 60, 70, 80 listed here are coupled to each other by a conveying unit 90, so that the workpiece 1 can be conveyed to each of the units. To this end, the conveying unit 90 has, for example, a conveyor belt, on which the units 10, 20, 30, 40, 50, 60, 70, 80 are arranged.
[0077]The device also has a control unit 30 to control the respective units 10, 20, 30, 40, 50, 60, 70, 80 and the conveying unit 90, so that the device can be used to perform the method according to the present invention. For this purpose, the control unit has a control device, for example in the form of a controller, which is configured to execute the method according to the invention by means of program code.
[0078]The fixing unit 40, the pretreatment unit 50, the distribution unit 60, the post-treatment unit 70, the coating unit 80, and the conveying unit 90 should only be understood as optional units here, and these units may also be omitted. The device thus obtained has only the cover applying unit 10, the liquid applying unit 20, and the control unit 30. The main steps of the method according to the present invention can also be executed with this equipment.
[0079]Similarly, it is not absolutely necessary to supply the workpiece 1 to each unit 10, 20, 30, 40, 50, 60, 70, 80 through the conveying unit 90, because the unit 10, 20, 30, 40, 50, 60, 70, 80 It may be configured to move toward the workpiece 1, for example.
[0080]The order of the units 10, 20, 30, 40, 50, 60, 70, 80 shown here is not absolutely necessary. On the contrary, other arrangements can also be set here. For example, the fixing unit 40 may be provided downstream of the liquid application unit 20. Thereby, the fixing device can fix not only the cover 3 but also the liquid 4, or only the liquid 4, as described above.
[0081]The liquid application unit 20 may also be arranged upstream of the cover application unit 10 in order to also apply the liquid 4 to the uncovered surface of the workpiece 1.
[0082]The origin of the present invention is such that it was unexpectedly discovered that the ink that has been applied to a partial area of the work piece made of solid wood then acts as a covering with respect to the liquid, here a dye or dyed liquid. In particular, the printed ink has an unexpected positive effect, that is, the fiber structure of the wood surface underneath will not be completely lost. That is, compared to before the application of the coloring agent, the wood structure can also be clearly visible due to the partially infiltrated coloring liquid in the area masked by the ink on the surface. Therefore, despite the partial coverage, the wooden structure is clearer on the overall surface, which is a very desirable effect.
