WO2020234149A1

WO2020234149A1 - Method for producing a decorative surface, in particular of a wood workpiece

Info

Publication number: WO2020234149A1
Application number: PCT/EP2020/063599
Authority: WO
Inventors: René Pankoke
Original assignee: Hymmen GmbH Maschinen- und Anlagenbau
Priority date: 2019-05-17
Filing date: 2020-05-15
Publication date: 2020-11-26
Also published as: CN112243411A; EP3758950A1; DE102019207277A1

Abstract

The invention relates to a method for producing a decorative surface on a workpiece (1), comprising the following steps: - feeding the workpiece (1), at least portions of the surface of which have wood or wood fibers, to a covering-substance application unit (10) and/or to a liquid application unit (20); - at least partially applying a covering substance (3) to the surface of the workpiece (1), the covering substance (3) being designed to at least partially seal the surface of the workpiece (1) at the locations at which the covering substance was applied, the covering substance (3) preferably being able to be digitally printed; and - applying a liquid (4) to the surface of the workpiece (1), the liquid (4) preferably being dyed and preferably containing dyes and/or pigments and/or having properties of a stain. The invention further relates to a device for carrying out the method.

Description

Method for producing a decorative surface, in particular one

Wooden workpiece

DESCRIPTION

The present invention relates to a method for producing a decorative surface of a workpiece and a device for performing the

Procedure.

State of the art:

According to the current state of the art, both solid wood floorboards and a so-called engineered floor, i.e. a multi-layer parquet or an artificial parquet, which is created by gluing a thin layer of wood, sometimes less than 1 mm, to a carrier board, become different colors through the application of pigmented Liquids ("stain") generated. These pickling liquids are brushed into the wood pores with so-called expeller rollers in order to also reach deeper points in the wood structure. According to the typical state of the art, pickling liquids are pigmented in such a way that they are at least partially transparent and the wood look underneath can still be seen. With this method, for example, a light-colored plank becomes a

so-called "smoked oak" made optically.

However, this manufacturing process only allows the entire surface of the workpiece to be treated. According to a further state of the art, there are high-quality floors that are laid as light real wood and with which certain patterns are then carried out on site

Pickling liquids are generated, e.g. Checkerboard pattern or something similar. With this technique, after the floor has been laid, the installer has to mask it off with adhesive tape (comparable to painter's tape) and leave certain areas open. The open areas are then soaked with pickling liquid, and the pickling is removed again after a certain exposure time.

This obviously very complex process then leads to certain patterns on the real wood that achieve a desired look in an interior. A similar manual procedure is also possible for furniture surfaces or table surfaces made of solid wood or a wood veneer or engineered wood (multi-layer parquet or multi-layer real wood, pressed wood). This wood stained in this way with the above-mentioned possible pattern is produced according to the current state of the art either over the full surface of the wood or with manual masking and a great deal of manual effort.

The idea behind the method according to the invention is therefore to use a very cheap wood, e.g. a birch veneer to create an optical "mahogany look veneer".

The object of the present invention or of the method according to the invention is to find a simple and industrially feasible possibility of nevertheless generating certain desired patterns on a real wood surface without manual masking and thereby significantly reducing the time and costs per square meter.

This object is achieved by the subjects of the independent claims. Advantageous further developments are the subject of the subclaims.

According to the invention, a method for producing a decorative surface on a workpiece is provided with the following steps: Feeding the workpiece, the surface of which has wood or wood fibers at least in some areas, to a

Cover substance application unit and / or to a liquid application unit;

at least partial application of a cover substance to the surface of the workpiece, the cover substance being designed to at least partially seal the surface of the workpiece at the points where it was applied, the cover substance preferably being digitally printable; and

Application of a liquid to the surface of the workpiece or to the covering substance, the liquid preferably being colored and

preferably contains dyes and / or color pigments and / or has the properties of a stain.

The interaction of the covering substance with the wood substrate is preferably limited to physical adhesion. The resulting attachment force of the

Cover substance on the surface of the workpiece is for the subsequent

Pickling process sufficient. The permeability of the liquid through the cover substance can preferably be controlled by the printed application amount of the cover substance. With a high application rate, the wood surface is almost completely sealed, with a lower application only partial masking; Wood pores,

Medullary rays and exposed areas are increasingly colored.

The control of the application amount of the covering substance is possible in terms of process technology. This can be done, for example, in a suitably designed

Cover substance application unit can be implemented. The

For this purpose, the cover substance application unit uses digital and / or analog printing technology.

The surface adhesion of the acidic liquid on the wood is preferably also based on physical adhesion. A characteristic of this is preferably the inadequate weathering resistance of dye stains, which is why the

Wood surface is usually still oiled or given a TopCoat. After the step of at least partially applying the covering substance, a step for drying and / or fixing the covering substance is preferably carried out. This is preferably done by supplying heat and / or by means of

Radiation hardening of the covering substance. The supply of heat to the cover substance can preferably take place by means of hot air and / or by means of infrared radiation. To

Radiation curing can preferably be radiated UV radiation onto the cover substance. The cover substance is preferably applied to the surface of the

Workpiece fixed. As a result of the fixation, the covering substance is connected to the surface of the workpiece, so that there is an increased adhesive force between the covering substance and the surface of the workpiece. The drying and / or fixing is preferably equivalent to a partial, particularly preferably a complete, hardening of the covering substance.

After the step of applying the liquid, a further step is preferably carried out in which the liquid is expelled by the liquid, preferably mechanically, particularly preferably with a

Expeller unit into which wood pores are distributed. This preferably improves the absorption of the liquid by the surface of the workpiece

guaranteed. The liquid is actively expelled into the wood pores, a portion of the liquid preferably being removed again from the surface of the workpiece. This portion is preferably not absorbable by the workpiece, since the workpiece is already saturated by absorbing the liquid. The expulsion takes place preferably by means of a brush, particularly preferably by means of a

Brush roller.

Preferably, after the step of applying the liquid and / or expelling the liquid, a further step is carried out by which the liquid is dried. The drying takes place preferably by means of supply of heat and / or radiation curing. The supply of heat to the liquid can preferably take place by means of hot air and / or by means of infrared radiation. For radiation curing, UV radiation can preferably be radiated onto the cover substance. A further step is preferably carried out in which the covering substance is removed again. This is preferably done by sanding the surface of the

Workpiece, particularly preferably also material of the workpiece is removed, whereby advantageously a uniformly treated surface of the

Workpiece is created.

The covering substance is preferably at least partially applied using an at least partially transparent ink. A highly transparent ink which does not contain any pigments is particularly preferably used for this purpose.

The at least partial application of the cover substance is preferably carried out according to a digital template. This is preferably done in such a way that after the liquid has been applied, it is only accepted in the unprinted areas of the underlying wooden surface of the workpiece or in the printed areas

Areas less strongly accepted than in the non-printed areas.

The covering substance advantageously acts as a seal between the surface of the workpiece and the liquid. The covering substance can accordingly

are advantageously applied in any pattern to the surface of the workpiece, so that the surface can be masked in any pattern. Subsequently, at least one unmasked, that is to say exposed, area of the surface of the workpiece can be brought into contact with the liquid, the liquid optically changing the surface of the workpiece in this area. Specifying a masking pattern using a digital template in particular has the advantage of being able to switch quickly between different patterns, so that a large number of different patterns or even completely individual, non-repetitive representations can be generated in a short time.

Preferably, the liquid at the points where the surface of the workpiece is not covered with the covering substance, the underlying substance

Wooden surface not completely covered in color. Instead, you can

preferably through a partially transparent layer of the liquid

Continue to recognize underlying wood pores, knotholes or other wood optics. The liquid preferably allows the wood grain to emerge more clearly on the entire surface of the workpiece, with the resulting

Color differences between open-pore and closed-pore parts of the wood surface in the masked areas are greater than in the non-masked areas.

The at least partial application of the covering substance and / or the application of the liquid to the surface of the workpiece are / is preferably carried out at least one more time. In this case, an optical influence or change in the surface of the workpiece can advantageously be achieved in that the liquid is applied several times at some points. The covering substance can also be applied in a second pass to previously unmasked areas of the surface of the workpiece, so that the masking is changed before the liquid is applied a second time. As a result, it is advantageously achieved that areas on the surface of the workpiece less often with the

Liquid come into contact than others, as these are now sealed by the later applied cover substance when the liquid is applied again. A further application could preferably also consist in coloring the wood or the wood fibers of the workpiece over the entire surface right at the beginning and then removing the excess, preferably then slightly sanding it if necessary. Only then does this take place on orders of the covering substance according to the

color the desired masking pattern and a second time. The overall color impression obtained is preferably a lower contrast between strong and less pronounced pigmentation.

In a second application, the liquid is preferably exchanged for another liquid with a different composition with regard to dyes and / or color pigments and / or stain properties.

The application of the liquid to the surface of the workpiece is preferably carried out at least one more time, the liquid being applied each time is identical to the previous application at least with regard to the dyes and / or color pigments contained, the application being carried out several times at least at one point on the surface of the workpiece. In this way, a more intensive optical change of the workpiece surface can be achieved.

It is particularly preferable for the workpiece or the liquid to be dried between two application steps.

The step of applying the liquid is preferably carried out at least once before the at least partial application of the covering substance. In this way, the surface of the workpiece can already be applied before the

Cover substance can be changed in parts or over the whole area by the liquid.

Before applying the liquid, a step is preferably carried out in which the surface of the workpiece is roughened at least partially, preferably over the entire area, the roughening preferably being carried out mechanically and / or chemically. The mechanical roughening is preferably carried out with a rubbing and / or grinding device. The chemical roughening is preferably done with a

Chemical that is designed to remove components of the wood fibers or even whole wood fibers from the workpiece. This is done, for example, by means of etching. The roughening has the advantageous effect that the capacity of the workpiece, at least on its surface, for the liquid is increased, so that the liquid or components contained therein, e.g. Color pigments, can more easily penetrate the workpiece.

The covering substance is preferably at least partially applied by means of digital printing technology and / or by means of analog printing technology. Digital printing technology is preferably to be understood as meaning inkjet or digital print heads which, particularly preferably, can be arranged over the entire width of the workpiece in order to be able to reach the entire surface of the workpiece as far as possible. Analogous printing technology is preferably to be understood as a printing roller which is designed to apply the covering substance by rolling it onto the surface of the workpiece according to a specific pattern. The underlying cover substance is preferably applied between 1 g / m ² and 10 g / m ² , particularly preferably between 3 g / m ² and 8 g / m ² . A further step is preferably carried out in which at least the liquid and / or the covering substance is removed from the surface of the workpiece. The removed liquid is preferably excess liquid which can no longer be absorbed by the workpiece, since it is already saturated. The liquid and / or the covering substance can preferably be actively removed. Active removal can in particular be understood to mean mechanical removal of the covering substance and / or the liquid with a brush and / or with a plane and / or with a grinding device. Particularly preferably, the material of the workpiece is also removed. A heating and / or evaporation of the covering substance and / or the

Fluid can be understood. A heat source such as e.g. a heater and / or a fan, which is designed to deliver hot air, and / or an infrared radiator can be used.

The liquid is preferably applied to the surface of the

Workpiece over the entire surface.

According to the invention, a device for performing the method according to one of the preceding claims is also provided, comprising:

- A cover substance application unit which is designed to provide a

To apply cover substance at least partially to the surface of the workpiece, the cover substance being designed to seal the surface of the workpiece at the points where it was applied;

a liquid application unit which is designed to apply a liquid to the surface of the workpiece, the liquid preferably being colored and preferably containing dyes and / or color pigments and / or having the properties of a stain; a control unit which is designed to control the device accordingly in order to carry out the method as described above.

The device preferably also has a fixing unit which is designed to dry the cover substance and / or the liquid, the fixing unit preferably having a fan and / or a heat source and / or a UV radiation source for this purpose.

The device preferably also has a preparation unit which is designed to prepare, in particular roughen the surface of the workpiece, the preparation unit preferably having a roughening roller and / or a grinding device and / or a dispensing device for dispensing a roughening substance, such as a grinding paste . It can also be a

Sandblasting device or the like can be provided.

The device preferably also has a distributor unit which is designed to distribute the liquid on the surface of the workpiece, the distributor unit preferably having a brush for this purpose.

Preferably, the device also has a post-processing unit which is designed to post-process the workpiece at least after the application of the covering substance and / or the liquid, the post-processing unit preferably having a grinding and / or planing device for this purpose.

Preferably, the device also has a coating unit which is designed to coat the surface of the workpiece. The coating can take place, for example, with a sealing lacquer layer, which is preferably applied to the workpiece in a last working step. For this purpose, the coating unit preferably has a casting device which is designed to form a lacquer curtain through which the workpiece is guided. Alternatively or additionally, the coating unit has an application roller which rolls off the surface of the workpiece and applies the paint there. Alternatively or In addition, the coating unit has an immersion basin, the workpiece being at least partially immersed in this immersion basin for coating with paint. As an alternative or in addition, the coating unit has digital printing technology which is designed to seal the workpiece by applying lacquer.

The device preferably also has a transport unit which is designed to feed the workpiece to at least some of the individual units, as described above. The transport unit has this

preferably a conveyor belt.

The transport unit is preferably designed to feed the workpiece at least one more time to at least one of the individual units described above. In this way, method steps can be carried out several times with a single unit without the need for a further unit for the same

Process step must be provided.

The device preferably has at least one of those described above

Units one more time. In this way it is possible to carry out a process step by providing a further unit at a later point in time

Carry out the procedure one more time.

The invention is explained in more detail below with reference to the accompanying drawings. They show: FIGS. 1a to 1c an embodiment of the method according to the invention,

2a to 2c possibilities of applying the covering substance or the liquid, and FIG. 3 shows a basic device for carrying out the

method according to the invention. 1a to 1c show a first embodiment of the method according to the invention.

In FIG. 1 a, a workpiece 1 is shown in side view, which is designed here as a plate-shaped workpiece 1. The workpiece 1 contains real wood or wood fibers at least in partial areas of the surface.

A covering substance 3 is applied to the upwardly facing surface of this workpiece 1. The covering substance 3 is applied in such a way that at least parts of the surface of the workpiece 1 are covered by the covering substance 3. The

The result of this application is shown in FIG. 1b. The covering substance 3 acts as a seal on the surface of the workpiece 1, so that the surface of the workpiece 1 is sealed in the areas to which the covering substance 3 was applied. The surface is thus masked for the next work step, i.e. parts of the surface of the workpiece 1 are still exposed.

In a further step, a liquid 4 is now on the surface of the

masked workpiece 1 applied. The liquid 4 only comes into contact with the exposed, ie unmasked, areas of the surface of the workpiece 1. The areas of the surface of the workpiece 1 sealed by the covering substance 3, however, do not come into contact with the liquid 4. This result is shown in Fig. 1c.

In an alternative embodiment, the masking of the surface of the

Workpiece 1 is not completely given by the cover substance 3 (“open pores”), so that the liquid 4 can partially penetrate the masked areas, but the amount is reduced compared to the unmasked areas.

The liquid 4 is designed to change the surface of the workpiece 1, especially in interaction with the real wood or with the wood fibers of the surface, at least visually upon contact. This interaction or optical change occurs only in the liquid effective areas 2, which, starting from the areas of the surface of the workpiece 1, which are connected to the liquid 4 in Contact are, extend into the workpiece 1. In this way, an optical change of the workpiece 1 as such can be achieved here.

In an alternative embodiment, an interaction with the liquid 4 can also take place in the other areas of the surface (not in the liquid active areas 2), but in a relative manner. the places 2 reduced dimensions.

In a special embodiment, the cover substance 3 also partially penetrates into the workpiece 1.

2a to 2c show alternative possibilities of achieving the intermediate results shown in FIGS. 1a to 1c.

In the embodiment shown, the application of the cover substance 3 takes place in the form of droplets 3a, which are marked here with a dashed border. This can be done, for example, using digital printing technology, such as a digital print head 11. In this way, the droplet release, in particular with regard to the release volume of the droplets 3a, can be actively influenced. The

Masking of the surface of the workpiece 1 by the cover substance is thus characterized by a high degree of variability in the masking pattern. The

Cover substance 3 is designed, for example, as a digitally printable ink or digitally printable paint.

As an alternative or in addition, the application of the cover substance 3 can also take place by means of an analog printing technique, as shown in FIG. 2b. The covering substance 3 can be applied to the surface of the workpiece 1 by means of an application roller 12, for example as an ink or lacquer. The application roller 12 rolls on the surface of the workpiece 1 and leaves the covering substance 3 on the

Surface to mask them. In summary, the covering substance can preferably be applied using printing techniques. Ideally, but not necessarily, it will be used for

more complex masking uses digital printing technology. The liquid 4 can, for example, be applied over a large or full area. In FIG. 2c, a pouring device 21 is shown by way of example, which produces a curtain consisting of the liquid 4, through which the workpiece 1 masked with the cover substance 3 is conveyed. The pouring device 21 has a reservoir in which the liquid 4 is stored and from which it is conveyed onto the surface of the workpiece 1, for example by means of a pump or, as shown, by means of a conveyor roller.

Another possibility (not shown) of applying the liquid 4 can be realized by an immersion basin into which the workpiece 1 is immersed at least with the masked surface.

In a further embodiment (not shown), the liquid 4 is applied to the masked surface by a roller application method.

3 shows a basic device for performing the method according to the invention.

A cover substance application unit 10 is shown which is designed to apply the cover substance 3 to a workpiece 1, as shown in FIGS. 1 a to 2 c.

to raise. For this purpose, the cover substance application unit 10 has, for example, a digital print head 11, as shown in FIG. 2a, or an application roller 12, as shown in FIG. 2b. Downstream of the cover substance application unit 10 is a

Liquid application unit 20 is provided, which is designed to the

To apply liquid 4 to the surface of the workpiece 1. For this purpose, the liquid application unit 20 has, for example, a pouring device 21, as shown in FIG. 2c, or an immersion basin, or a roller application unit.

Furthermore, a fixing unit 40 is shown, which between the

Cover substance application unit 10 and the liquid application unit 20 is provided. The fixing unit 40 is designed to allow drying of the Carry out cover substance 3 before the liquid 4 is applied. For this purpose, the fixing unit 40 has, for example, a nozzle channel which allows hot air to flow onto the surface of the workpiece 1 or onto the cover substance 3. As an alternative or in addition, a heat source in the form of an infrared radiation source or a heater can also be provided in order to dry the cover substance 3. The

Fixing unit 40 can also have a UV radiation source, around the

Curing the covering substance or fixing it on the surface of the workpiece 1.

In front of the cover substance application unit 10, a preparation unit 50 is provided, which is designed to prepare the surface of the workpiece 1 for the further process steps. For example, a

Roughening roller or a grinding device can be provided, which are designed to mechanically roughen the surface of the workpiece 1. Alternatively or in addition, a dispensing device can also be provided here, which is designed to apply a cleaning agent, for example a chemical substance such as an acid, to the surface of the workpiece 1. For example, in interaction of the cleaning agent with the wood fibers of the workpiece 1, it is achieved that these change accordingly, that the surface of the workpiece 1 becomes rougher, so that in particular absorption of the liquid 4 is facilitated.

The liquid application unit 20 is followed by a distributor unit 60 which is designed to distribute the liquid 4 on the surface of the workpiece 1 or to work it into the surface of the workpiece 1. The

Distributor unit 60 can do this mechanically, for example. For this purpose, the distributor unit 60 has, for example, a brush or roller brush that comes into contact with the surface of the workpiece 1 and moves relative to it

Liquid 4 distributes or incorporates. The dispenser unit 60 can also be in the form of multiple rotary brushes (with an axis perpendicular to the surface of the

Workpiece). Further alternative embodiments are also conceivable.

After the distributor unit 60, a post-processing unit 70 is provided, which is designed to post-process the surface of the workpiece. This can for example done mechanically. For this purpose, a grinding device can be provided which is designed to remove the surface of the workpiece 1, in particular the covering substance 3 and / or liquid 4 located thereon. In this case, material of the workpiece 1 itself is preferably also removed in order to avoid the optical

Change in the workpiece 1, which has set in by the liquid 4 in deeper layers, to be exposed.

Furthermore, a coating unit 80 can be provided, which is designed to coat the surface of the workpiece 1. This can be done, for example, with a varnish that is applied over the entire surface, whereby a final sealing of the workpiece 1 is preferably carried out, so that the optical

changed surface of the workpiece 1 is protected. The lacquer for sealing is therefore at least partially transparent. Acrylate-containing UV-curing lacquers as well as oils or waxes can be used as sealing materials. Also water-based paint systems with subsequent thermal

Drying are conceivable.

All of the units 10, 20, 30, 40, 50, 60, 70, 80 listed here are connected to one another by a transport unit 90 in such a way that the workpiece 1 can be transported to the individual units. For this purpose, the transport unit 90 has, for example, a transport belt, the units 10, 20, 30, 40, 50, 60, 70, 80 being arranged on the transport belt.

The device also has a control unit 30 in order to control the individual units 10, 20, 30, 40, 50, 60, 70, 80 and the transport unit 90 so that the method according to the invention can be carried out with the device. For this purpose, the control unit 30 has, for example, a control means in the form of a control device which is designed by means of program code to carry out the method according to the invention.

The fixing unit 40, the preparation unit 50, the distribution unit 60, the post-processing unit 70, the coating unit 80 and the transport unit 90 are only to be understood here as optional units that are also omitted can be. The device thus obtained then only has the

Cover substance application unit 10, the liquid application unit 20 and the control unit 30. The process steps essential to the invention can also be carried out with such a device.

Feeding the workpiece 1 to the individual units 10, 20, 30, 40, 50, 60, 70, 80 by the transport unit 90 is also not absolutely necessary, since the units 10, 20, 30, 40, 50, 60, 70, 80 can be designed to move towards workpiece 1, for example.

The sequence shown for the units 10, 20, 30, 40, 50, 60, 70, 80 is also not absolutely necessary. Rather, other arrangements can also be provided here. The fixing unit 40 can, for example, behind the

Liquid application unit 20 may be provided. It is thus able to fix not only the covering substance 3 but also the liquid 4, or even just the liquid 4, as already explained above.

In front of the cover substance application unit 10, a

Liquid application unit 20 can be provided in order to also apply the liquid 4 to the unmasked surface of the workpiece 1.

The trigger for the present invention was the surprising finding that ink, which was applied to partial areas of a workpiece made of real wood, then acts as a covering substance against a liquid, here a stain or a pigmented liquid. In particular, a surprisingly positive effect of the printed ink was that the fiber structure of the wood surface underneath was not completely lost. In other words, even in the areas of the surface masked by the ink, the wood structure was more clearly visible due to partial penetration of the stain than before the stain was applied. Thus, despite the partial masking of the surface as a whole, the wood structure became much clearer, which was a very desirable effect. Therefore, for a more detailed understanding of the invention, specific embodiments of the invention will finally be described with reference to those explained above

Drawings that can be assigned to this special application. In a special embodiment of the invention, a workpiece 1, the surface of which is at least partially made of real wood, is fed to a printing station, in which the surface of the workpiece 1 is completely or partially printed with a cover substance 3 in the form of a digitally printable ink. A pigmented liquid 4 is then applied to this printed surface, the pigmented liquid 4 coming into contact in particular with areas that are not printed with the cover substance 3. Between the first printing with the

Cover substance 3 and the application of the pigmented liquid 4 can be a

Drying takes place by means of hot air, infrared and / or radiation curing. The applied after the possible drying pigmented liquid 4 is with a

Expeller brush mechanically into the pores of the real wood on the surface of the

Workpiece 1 introduced. The pigmented liquid 4 applied in this way, which preferably has caustic properties, can then be dried. In a further step, the surface of the workpiece 1 produced in this way can be sanded in such a way that the printed cover substance 3 is removed again and only the color pigments that have penetrated deeper into the wood structure are retained, thus creating a printed image.

In a further embodiment, a second application of a liquid 4 can also take place using a liquid 4 in the form of a highly transparent ink without any pigments. In a further embodiment, the pigmented liquid 4 can only partially cover the underlying wood surface at the points where the wood surface is not applied with the covering substance 3, so that the wood pores, knotholes and other wood optics remain recognizable through a transparent layer. The process steps for dye and liquid application are repeated several times, but at least twice, with the pigmented liquid 4 being exchanged in the second application step for another pigmented liquid 4 with other colored pigments so that a multicolored or at least two-colored image is created.

In a further embodiment, the process steps for coloring and liquid application are repeated several times, but at least twice, the pigmented liquid 4 containing the same color pigments as those of the preceding process steps and so other colors can be achieved in some places by double application.

In a specific embodiment, the liquid 4 as a pickle has a vapor pressure at 20 ° C. of 23 hPA, a density at 20 ° C. of 1.01 g / cm ³ , a kinematic one

Viscosity at 20 ° C of 12 s (according to DIN 53211/4). It also contains 1.8% organic solvents, 92.7% water and the solids content is 5.4%.

In a specific embodiment, the cover substance 3 is designed as Himalia03 ™ ink.

This has a density at 20 ° C. of 1.09 g / cm ³ , a surface tension of 16 to 39 dynes / cm, a kinematic viscosity at 20 ° C. of 16 s (according to DIN 53211/4). The nominal volume of the droplets 3a from this cover substance 3 is 6 to 42 pL (using a Xaar GS6 ™ print head). Depending on the working window, this volume can be increased to 8 to 56 pL.

The main components are: <40 wt% 2- (2-ethoxyethoxy) ethylene acrylate, <40 wt%

Trimethylolpropane, ethoxylated, esterified with acrylic acid, <40 wt%

Dipentaerythritol hexaacrylate. Furthermore, it contains no organic solvents, no water, no pigment or dye. Using digital printing technology, the covering substance 3 (density 1.09 g / L at 20 ° C) of 1.3 g / m ² (LeveM) to 8.9 g / m ² (Level7) can be applied. The

In this case, level information relates to the control of print heads in a digital application device.

In a special embodiment, the covering substance 3 also penetrates the wood substrate due to the low viscosity (kinematic viscosity 16 s, DIN 5321 1/4, 20 ° C.) and the pronounced capillary action of the wood fibers.

The initial boiling point of the covering substance 3 in is 101 ° C. and, according to the standard, does not hold any UV initiators. The covering substance 3, however, is compatible for addition of a UV initiator and capable of photopolymerization. In the case of a completely cross-linked covering substance, the scratch hardness is not greater than 3 N.

REFERENCE LIST

1 workpiece

2 Effective range of fluids

3 covering substance

3a droplets

4 liquid

10 Cover substance application unit

11 digital print head

12 Order roll

20 liquid application unit

21 pouring device

30 control unit

40 fixation unit

50 preparation unit

60 distributor unit

70 post-processing unit

80 coating unit

90 transport unit

Claims

EXPECTATIONS

1. A method for producing a decorative surface on a workpiece (1) with the following steps:

Feeding the workpiece (1), the surface of which at least in

Has partial areas of wood or wood fibers to one

Cover substance application unit (10) and / or to a

Liquid application unit (20);

at least partial application of a cover substance (3) to the surface of the workpiece (1), the cover substance (3) being designed to at least partially seal the surface of the workpiece (1) at the points where it was applied, the Cover substance (3) is preferably designed to be digitally printable; and

Applying a liquid (4) to the surface of the workpiece (1), the liquid (4) preferably being colored and preferably containing dyes and / or color pigments and / or having the properties of a stain.

2. The method of claim 1, wherein

after the step of at least partially applying the covering substance (3), a step of drying the covering substance (3) is carried out, preferably by means of supplying heat and / or radiation curing of the covering substance (3).

3. The method according to any one of the above claims, wherein

after the step of applying the liquid (4), a further step is carried out in which the liquid (4) is expelled by distributing the liquid (4), preferably mechanically, into the wood pores with a expeller unit (60) and this ensures better absorption of the liquid (4) through the surface of the workpiece (1).

4. The method according to any one of the above claims, wherein

after the step of applying the liquid (4) and / or expelling the liquid (4) according to claim 3, a further step is carried out by means of which the liquid (4) is dried, preferably by means of supply of heat and / or radiation curing.

5. The method according to any one of the above claims, wherein

a further step is carried out in which the covering substance (3),

is removed again preferably by grinding the surface of the workpiece (1).

6. The method according to any one of the above claims, wherein

the at least partial application of the cover substance (3) is carried out using an at least partially transparent ink, preferably using a highly transparent ink that does not contain any pigments.

7. The method according to any one of the above claims, wherein

the at least partial application of the cover substance (3) takes place according to a digital template, preferably in such a way that, after the application of the liquid (4), it is only in the unprinted areas of the underlying

Wood surface of the workpiece (1) is accepted, or is accepted less strongly in the printed areas than in the non-printed areas.

8. The method according to any one of the above claims, wherein

the liquid (4) at the points where the surface of the workpiece (1) is not covered with the covering substance (3) does not completely cover the underlying wood surface in color

9. The method according to any one of the above claims, wherein

the liquid (4) on the entire surface of the workpiece (1) allows the wood grain to emerge more clearly, the resulting

Color differences between the open-pore and closed-pore parts of the wood surface (1) are greater in the masked areas than in the non-masked areas.

10. The method according to any one of the above claims, wherein the at least partial application of the covering substance (3) and / or the application of the liquid (4) to the surface of the workpiece (1) are / is carried out at least one more time, with the liquid (4) preferably being applied against a another liquid with another

Composition in terms of dyes and / or color pigments is exchanged.

11. The method according to any one of the above claims, wherein

the application of the liquid (4) to the surface of the workpiece (1) is carried out at least one more time, and the liquid (4) is identical to the previous application each time, at least in terms of the dyes and / or color pigments it contains, the application takes place several times at least at one point on the surface of the workpiece (1).

12. The method according to any one of the above claims, wherein

the step of applying the liquid (4) is also carried out at least once before the at least partial application of the covering substance (3).

13. The method according to any one of the above claims, wherein

before the liquid (4) is applied, a step is carried out which roughen the surface of the workpiece (1) at least partially, preferably over the entire area, the roughening preferably taking place mechanically and / or chemically.

14. The method according to any one of the above claims, wherein

the at least partial application of the covering substance (3) by means of

Digital printing technology and / or by means of analog printing technology takes place.

15. The method according to any one of the above claims, wherein

a further step is carried out in which the liquid (4) and / or the covering substance (3) is removed from the surface of the workpiece (1).

16. The method according to any one of the above claims, wherein

the liquid (4) is applied over the entire surface of the workpiece (1).

17. Device for performing the method according to one of the

preceding claims, comprising:

- A covering substance application unit (10) which is designed to apply a covering substance (3) at least partially to the surface of the workpiece (1), the covering substance (3) being designed to apply the surface of the workpiece (1) to the locations to which it was applied to seal;

- A liquid application unit (20) which is designed to apply a liquid (4) to the surface of the workpiece (1), wherein the

Liquid (4) is preferably colored and preferably contains dyes and / or color pigments and / or has the properties of a stain;

- A control unit (30) which is designed to control the device

to be controlled accordingly in order to effect the implementation of the method according to one of claims 1 to 15.

18. The apparatus of claim 17, further comprising:

- A fixing unit (40) which is designed to dry the covering substance (3) and / or the liquid (4), the fixing unit (40) preferably being a fan and / or a heat source and / or a UV radiation source for this purpose having; and or

- A preparation unit (50) which is designed to prepare the surface of the workpiece (1), in particular to roughen it, wherein the

For this purpose, the preparation unit (50) preferably has a roughening roller and / or a grinding device and / or a dispensing device for dispensing a roughening substance; and or

- A distributor unit (60) which is designed to distribute the liquid (4) on the surface of the workpiece (1), the distributor unit (60) preferably having a brush for this purpose; and or

- A post-processing unit (70) which is designed to post-process the workpiece (1) at least after application of the cover substance (3) and / or the liquid (4), the post-processing unit (70) preferably being a grinding and / or planing device for this purpose having; and or - A coating unit (80) which is designed to coat the surface of the workpiece (1); and or

- A transport unit (90) which is designed to feed the workpiece (1) to the individual units (10, 20, 30, 40, 50, 60, 70, 80), the

Transport unit (90) preferably has a transport belt for this purpose.

19. The apparatus of claim 18, wherein

the transport unit (90) is designed to feed the workpiece (1) to at least one of the individual units (10, 20, 30, 40, 50, 60, 70, 80) at least one more time.

20. Device according to one of claims 17 to 19, wherein

the device has at least one of the units (10, 20, 30, 40, 50, 60, 70, 80) one more time.