EP3967494A1 - Device for generating a print on a printing material and method for controlling the volume of cavities on a printing form - Google Patents

Abstract

The invention relates to a device for generating a print on a printing material (30), the device comprising at least one printing forme, at least one device for dispensing a print medium, at least one device for data transmission and at least one device for control. The printing form has a printing body, a large number of actuators (45, 46, 150, 151), a separating layer (110) with a large number of perforations (111, 112) and a cover layer (42). According to the invention, at least one actuator (45, 46, 150, 151) is connected to the cover layer (42) by at least one perforation (111, 112) and each actuator (45, 46, 150, 151) is independent of the other actuators (45, 46, 150, 151) electrically addressable. The cover layer (42) is set up to form a large number of cavities (60, 61) for accommodating a print medium or has a large number of cavities (60, 61) for accommodating a print medium, each cavity (60, 61) having a suction volume for the print medium, which is controllable.

Description

field of invention

The invention relates to a device for generating a print on a printing material, the device comprising at least one printing forme, at least one device for dispensing a print medium, at least one device for data transmission and at least one device for control. The printing form has a printing body, a large number of actuators, a separating layer with a large number of perforations and a cover layer. According to the invention, at least one actuator is connected to the cover layer by at least one perforation, and each actuator can be electrically addressed independently of the other actuators. The cover layer is set up to form a multiplicity of cavities for accommodating a print medium or has a multiplicity of cavities for accommodating a print medium, with each cavity having a controllable scoop volume for the print medium.

description

There are a variety of technical solutions for the reproduction of print patterns or the duplication of print patterns. The term printing technology includes all processes for duplicating print samples, such as letterpress, offset printing, gravure printing, flexographic printing, screen printing and digital printing. Different methods are used in these printing techniques in order to transfer a printing medium, such as an ink, to a printing material. Each printing technique offers different advantages and is used accordingly in different areas of application.

The areas of application of printing technology are very diverse. For example, the printing of print media, wallpaper or the like is known. So-called decorative printing is used, for example, in the production of floor laminate or wall and ceiling paneling elements. Wood-based panels are often printed here. There are several approaches to decorating wood-based panels. In the past, wood-based panels were often coated with a decorative paper, with the variety of decorative papers with different patterns being unlimited. As an alternative to the use of decorative papers on wood-based panels, the possibility of direct printing on wood-based panels has developed, with printing on paper and its subsequent laminating or direct coating on the wood-based panels being omitted. The printing techniques mainly used here are gravure and intaglio digital printing process. For the use of this printing process, the print decor is available as a digital template that depicts the colors and color distribution of the print decor.

The gravure printing process is a printing technique in which the elements to be reproduced are present as cavities, i.e. indentations, in a static pressure body, e.g. a printing roller or a printing plate, which is provided with a printing medium, such as ink, before printing. The printing medium is primarily in the depressions and is transferred to the object to be printed, the printing substrate, due to the contact pressure of the printing form and adhesive forces. In gravure printing it is possible to print mixed colors and color gradients. The printing media used for gravure printing, in particular the pigment-containing liquids such as inks, are available in a wide range and are relatively inexpensive.

There are essentially two different ways of constructing the printing form for gravure printing, these are explained below using a printing roller as an example. In the case of the printing roller, a steel cylinder is encased in a 2mm thick layer of copper, which is called base copper. Either an engravable copper layer of about 100 µm is galvanized on this inner copper layer or a removable Ballard skin is applied. There is a separating layer between the Ballard skin and the base copper, which means that the Ballard skin can be removed after printing and replaced with a new one.

In gravure printing, the print pattern is broken down into tiny printing elements called cells, surrounded by non-printing elements called ridges. The print pattern is accordingly broken down into a grid in gravure printing. The cells are filled with the printing medium before printing and excess printing medium is usually wiped off with a squeegee. The squeegee consists of a steel ruler corresponding to the length of the printing cylinder. The print pattern is applied in the form of a grid to the copper layer that can be engraved or to the Ballard skin. This can be done by chemical etching, electromechanically or by means of a laser. In any case, a static printing form is created with an unchangeable arrangement of cells. If a multicolored print pattern is to be printed, a separation file is created at the beginning of the printing process, in which the print pattern is broken down into the primary colors to be printed. The arrangement of the cells on the printing form is different for each color to be printed, so in conventional gravure printing an associated Ballard skin must be made for each color. In the printing process, the individual primary colors are then printed one after the other on the substrate.

The Ballard skin of a print roller can be replaced. To do this, the Ballard skin must first be removed from the roller body, then the roller body is cleaned and provided with a new separating layer. A new Ballard skin can then be applied to the new release liner.

The disadvantage of gravure printing is that at least one Ballard skin has to be made for each print pattern, and the arrangement of the cells can no longer be changed. This makes gravure printing expensive in many respects. Not only must the Ballard skins be made separately for each print sample, but they must also be stored after the print is completed. In addition, changing the Ballard skins on the pressure bodies is complicated and time-consuming.

Furthermore, the width/length of the print pattern is limited to the size of the printing form. Either by the circumference and width of the printing roller or by the dimensions of the printing plate. The circumference of the print roller limits the print data length of the print pattern and the width of the print roller limits the print data width of the print pattern. The person skilled in the art understands print data length to mean the length of the finished printed print pattern and print data width to mean the width of the finished printed print pattern. If a larger print pattern is to be printed than the printing form allows, this must be done in parts. This procedure is very complex and error-prone, since the transitions between the individually printed parts of the print pattern must be maintained exactly in order to obtain a harmonious print result.

In addition, some printing tasks are printed in repeat. Repeat designates a constantly recurring same print pattern. In gravure printing, print rollers are used for printing with a repeat, with the repeat being determined by the circumference of the print roller. The maximum print data length of the print pattern that recurs in the repeat can be as long as the circumference of the roller. In this case, a repeat, i.e. the print pattern, is printed once with one revolution of the roller. If the print pattern is shorter, i.e. several repeats fit on one roll circumference, the print data length of the print pattern must be selected so that the circumference of the print roller is optimally used. This is the only way to ensure an economical way of working. In addition to many advantages, in particular with the possibility of displaying color gradients, using mixed colors and printing at high speed without loss of quality in the print resolution, gravure printing therefore also has the disadvantages mentioned.

Some of these disadvantages should be eliminated by using digital printing. With digital printing, the print pattern is transferred directly from a computer to a digital printer such as a laser printer or inkjet printer. In digital printing, therefore, the use of static printing forms and thus the limitations in the print data length and print data width of the print pattern are no longer necessary. Digital printing thus offers a high level of flexibility and variability with regard to the print motifs and does not entail any restrictions in the repeat.

From the prior art, digital printing is also known, for example, for printing wood-based panels. the EP 2 181 852 B1 for example, relates to a digital printing process for printing on flat wood-based panels. The flat panels are printed directly with a digital printer.

the EP 2 636 531 A1 also relates to a digital printing method for printing on a surface of a workpiece. In this case, a print roller is provided with a print pattern by a digital printer and this print pattern is then applied to the workpiece by the print roller.

The basic colors cyan, magenta, yellow and black (CMYK) are usually used in digital printing. The CMYK color model is a subtractive color model, with the abbreviation CMYK standing for the three color components cyan, magenta, yellow and the black component key as the color depth. With this color system, a color space (gamut) can be mapped that satisfies many requirements from a wide variety of areas. However, the representation of color gradients or mixed colors is not possible with digital printing.

With digital printing, the print medium is applied drop by drop to the substrate. As the drop exits the print head nozzle, it typically forms a ligament that, in the best case, is sucked into the drop. However, it also happens that the ligament atomizes and forms a fine mist. This spray fouls the nozzles of the print head and other elements of the printing device. Over time, this degrades the print quality and cleaning of the printer is necessary. This is time-consuming and therefore incurs costs. In addition, the spray mist accumulates in the surrounding air over time and poses a health risk to the workers who operate the machines.

Part of the ligament can also detach in the front part of the drop and then forms a so-called satellite on the substrate. This degrades the print image and thus the quality of the print.

Another problem is the condensation of water vapor on the print head, which can lead to poor print quality or even damage the print head.

Furthermore, air turbulence that occurs during the printing process can lead to a blurred print image. In addition, due to their technical design, digital printers are often prone to malfunctions in the print heads. If a print head fails, this is immediately recognizable as streaks in the print image on the substrate.

Digital printing can therefore eliminate some of the disadvantages of gravure printing, but it also has disadvantages in terms of print quality.

It would therefore be desirable to have a printing process that enables a high degree of flexibility and variability with regard to the print pattern, in particular with regard to its print data length, and at the same time is characterized by a robust printing technique that can be used economically. None of the methods from the prior art mentioned at the outset can meet these requirements.

The object of the present invention is therefore to overcome the disadvantages of the prior art and to provide a device and a method for producing a print on a substrate which combines the robust and economical gravure printing technology with great flexibility with regard to the printable Print patterns of digital printing combined.

• mindestens eine Druckform;
• mindestens eine Vorrichtung zur Abgabe eines Druckmediums;
• mindestens eine Vorrichtung zur Datenübertragung;
• mindestens eine Vorrichtung zur Steuerung;

dadurch gekennzeichnet, dass
die Druckform einen Druckkörper, eine Vielzahl von Aktoren, eine Trennschicht mit einer Vielzahl von Perforationen und eine Deckschicht aufweist;
mindestens ein Aktor mit der Deckschicht durch mindestens eine Perforation verbunden ist; und
jeder Aktor unabhängig von den weiteren Aktoren elektrisch ansprechbar ist;
wobei die Deckschicht dazu eingerichtet ist, eine Vielzahl von Kavitäten zur Aufnahme eines Druckmediums auszubilden oder wobei die Deckschicht eine Vielzahl von Kavitäten zur Aufnahme eines Druckmediums aufweist; und
wobei jede Kavität ein Schöpfvolumen für das Druckmedium aufweist, welches steuerbar ist.This object is achieved by the present invention in that a device for generating a print on a printing material is made available, comprising

• at least one printing form;
• at least one device for dispensing a print medium;
• at least one device for data transmission;
• at least one control device;

characterized in that
the printing forme has a printing body, a multiplicity of actuators, a separating layer with a multiplicity of perforations and a cover layer;
at least one actuator is connected to the cover layer by at least one perforation; and
each actuator is electrically addressable independently of the other actuators;
wherein the cover layer is set up to form a multiplicity of cavities for accommodating a print medium or wherein the cover layer has a multiplicity of cavities for accommodating a print medium; and
each cavity having a scoop volume for the pressure medium which is controllable.

• eine Spannung an jedem Aktor angelegt wird, an dessen Position eine Kavität an der Oberfläche der Druckform entstehen soll;
• durch die angelegte Spannung die Deckschicht verformt wird und dadurch an dieser Position eine Kavität an der Oberfläche der Druckform gebildet wird.

Furthermore, a method for producing a large number of cavities on a printing form by means of a device according to one of claims 1 to 3 is described, wherein each actuator can be electrically addressed independently of the other actuators via a controller and thereby acts on the cover layer,
characterized in that

• a voltage is applied to each actuator at the position of which a cavity is to be created on the surface of the printing form;
• the top layer is deformed by the applied voltage and a cavity is thereby formed on the surface of the printing form at this position.

• eine Spannung an mindestens einem Aktor angelegt wird;
• Druckgas aus dem Druckkörper durch den Kanal in die mit dem mindestens einen Aktor verbundene mindestens eine Kavität entweicht oder ein Medium in einen Hohlraum in der Deckschicht eingebracht wird oder das Sleeve durch Druck verformt wird;
• ein Druckmedium auf die Druckform aufgebracht wird;
• wobei das Schöpfvolumen der mindestens einen Kavität durch den Volumenstrom des ausströmenden Druckgases oder durch das Volumen des in den Hohlraum strömenden Mediums oder durch die Größe des Drucks mit dem das Sleeve verformt wird, gesteuert wird.

In addition, a method for controlling the scoop volume of cavities on a printing form by means of a device according to one of Claims 4 to 8 is made available, each actuator being electrically addressable independently of the other actuators via a controller , characterized in that

• a voltage is applied to at least one actuator;
• Compressed gas escapes from the pressure body through the channel into the at least one cavity connected to the at least one actuator, or a medium is introduced into a cavity in the cover layer, or the sleeve is deformed by pressure;
• a printing medium is applied to the printing form;
• wherein the scoop volume of the at least one cavity is controlled by the volume flow of the outflowing compressed gas or by the volume of the medium flowing into the cavity or by the magnitude of the pressure with which the sleeve is deformed.

• die Aktoren elektrisch angesteuert werden, so dass die Kavitäten Schöpfvolumen eines Druckmediums aufnehmen können, die dazu geeignet sind, das digitale Druckmuster auf einem Bedruckstoff abzubilden oder dass auf der Druckform Kavitäten mit Schöpfvolumen ausgebildet werden, die dazu geeignet sind, das digitale Druckmuster auf einem Bedruckstoff abzubilden;
• von der Druckform ein Druckmedium durch eine Vorrichtung zur Abgabe eines Druckmediums aufgenommen wird; und
• das digitale Druckmuster mit der Vorrichtung direkt oder indirekt auf den Bedruckstoff gedruckt wird.

Furthermore, a method for printing a printing material with a device according to one of claims 1 to 10 with a digital print pattern is described, characterized in that

• the actuators are controlled electrically, so that the cavities can hold a volume of a print medium that is suitable for imaging the digital print pattern on a printing substrate or that cavities with a volume that are suitable for imaging the digital print pattern on a printing substrate are formed on the printing form to depict;
• a print medium is picked up from the printing form by a device for dispensing a print medium; and
• the digital print pattern is printed directly or indirectly onto the substrate with the device.

The device according to the invention for generating a print on a printing material comprises at least one printing forme, at least one device for dispensing a print medium, at least one device for data transmission and at least one device for control.

The printing form of the present invention comprises a printing body, a multiplicity of actuators, a release layer with a multiplicity of perforations and a cover layer. According to the invention, the pressure body is a pressure body as is known from gravure printing. The pressure body is preferably a pressure roller or a pressure plate. In a preferred embodiment of the invention, the pressure body is a pressure roller. Steel cylinders, for example, are typical here. The pressure body can have all the usual dimensions in the field of printing.

According to the invention, the multiplicity of actuators is arranged within the pressure body in such a way that at least one actuator is adjacent to the separating layer. The separating layer is arranged on the surface of the printing hull and the covering layer in turn is arranged on the separating layer. In a preferred embodiment of the invention, all actuators are arranged in such a way that each actuator is adjacent to the separating layer.

The separating layer has a large number of perforations. These protrude through the separating layer in the form of channels that run from the pressure hull to the cover layer. The separating layer preferably has a material on which a stable perforation can be produced and which has sufficient flexibility to be applied to a printing cylinder. The separating layer therefore has a material from the group containing metals and plastics. In one embodiment of the present invention, the separating layer comprises copper, aluminum or stainless steel.

The perforations of the separating layer can all have the same cross-section or different cross-sections. In one embodiment of the invention, the perforations have a circular cross-section or a polygonal cross-section. In another embodiment of the invention, the cross section is irregularly shaped. According to the invention, the cross-sectional area of the perforation is not larger than the area with which an actuator borders the separating layer. The cross-sectional area of the perforation is preferably smaller than the area with which an actuator borders the separating layer.

In one embodiment of the invention, the separating layer has a thickness of between 10 μm and 500 μm, preferably between 20 μm and 100 μm, particularly preferably between 25 μm and 50 μm. The thickness of the separating layer describes its extent from the pressure hull to the top layer. The separating layer advantageously covers the surface of the entire pressure hull.

In a preferred embodiment of the invention, the actuator has at least one component selected from the group containing piezo actuators, valves, combinations of valves and valves with nozzles. In a further embodiment, the actuator also has a device that is suitable for opening and closing valves. In one embodiment of the invention, the actuator is a piezo actuator. In a further embodiment of the invention, the actuator is a valve.

In piezoelectric materials, pressure causes charges to build up on the surfaces of the material. Conversely, the inverse piezoelectric effect in these materials causes a change in length when an electrical voltage is applied. This actuator effect converts electrical energy into mechanical energy and is used in so-called piezo actuators. Piezo actuators, which are known from the prior art, enable adjustment paths between a few 10 μm and a few millimeters, depending on their structure. For example, longitudinal actuators, shear actuators, tube actuators, contractors and bending actuators are known to the person skilled in the art. While longitudinal actuators can achieve travels in the range from a few 10 µm to a few 100 µm, bending actuators are characterized by travels of up to a few millimeters.

In some designs, the piezo actuators have several layers of piezoelectric materials. The travel of the piezoelectric actuator can be increased by the formation of so-called stack actuators. In longitudinal piezo actuators, for example, the electric field is applied in a layer of piezoelectric material parallel to the direction of polarization. This causes an elongation or deflection in the direction of the polarization induced. Individual layers of a piezoelectric material provide relatively small deflections. However, due to the formation of stack actuators, the deflection of the individual layers adds up and the travel is increased.

Piezoelectric materials such as certain crystals, piezoelectric ceramics or plastics are known to those skilled in the art. Examples of piezoelectric crystals include quartz, lithium niobate, gallium orthophosphate, berlinite, minerals from the tourmaline group, Seignett salt and any ferroelectric such as barium titanate (BTO) or lead zirconate titanate (PZT). Known piezoelectric ceramics are, for example, barium titanate (BTO) and lead zirconate titanate (PZT) in polycrystalline form, lead magnesium niobates (PMN). Polyvinylidene fluoride (PVDF), for example, is a representative of the plastics that can exhibit piezoelectric properties.

The piezo actuators are arranged in the pressure body in such a way that each piezo actuator can be electrically addressed individually and independently of the other piezo actuators. A controllable voltage can be applied to each piezo actuator so that the piezo actuators can be deformed. The piezoelectric actuators are arranged in the pressure body in such a way that, when no voltage is applied, they are adjacent to the separating layer. According to the invention, the piezo actuators lie against the separating layer, but are not firmly connected to it.

In a further embodiment of the invention, the actuators have valves. According to the invention, valves are components with which the inflow, outflow and/or passage of media such as liquids or gases is controlled. This can be done, for example, by opening the valve. According to the present invention, the degree of opening of a valve is controllable by an applied voltage to a device for controlling the degree of opening of the valve. Suitable valves are known to those skilled in the art from the prior art. In one embodiment of the invention, the valve additionally has a nozzle through which the medium is conducted.

According to the invention, at least one actuator is connected to the cover layer by at least one perforation. In a preferred embodiment, each actuator is connected to the cover layer by at least one perforation. Each actuator is particularly preferably connected to the cover layer by a plurality of perforations in the separating layer.

In one embodiment of the present invention, the cover layer is set up to form a multiplicity of cavities for receiving a print medium, it being possible for each actuator to form at least one cavity.

If the actuators are in the form of piezo actuators, in one embodiment of the invention a voltage is applied to a piezo actuator, as a result of which the piezo actuator is deformed and a cavity is created between the piezo actuator and the separating layer. If the actuators have valves or valves with nozzles, the valves are designed in such a way that opening the valves also creates a cavity between the valve and the separating layer.

According to the invention, at least one perforation of the separating layer adjoins the cavity in such a way that the exchange of a gaseous or liquid medium between the cavity and the perforation is made possible. According to the invention, a medium that is located in the adjoining perforations of the separating layer can therefore penetrate into the cavity. This action reduces the pressure in the perforations, in a preferred embodiment this action creates a negative pressure in the cavity and in each perforation adjacent to the cavity. Due to the change in pressure, the cover layer lying above the cavity and the adjoining perforations is arched in the direction of the piezo actuator, with the result that a cavity is formed on the surface of the cover layer. If the actuators are controlled in such a way that the valve closes or the piezo actuator is no longer deformed, there is no longer any negative pressure and accordingly no cavity is formed on the surface of the cover layer. The cavities can therefore advantageously be formed in a variable location on the surface of the cover layer. This allows the cavities to be flexibly adapted to print templates.

In a further embodiment of the invention, there is at least one cavity in the cover layer, which cavity is connected to the actuator through at least one perforation in the separating layer. If the control of the actuators creates a cavity between the actuator and the separating layer, a medium that is in the at least one cavity in the cover layer can penetrate through the at least one perforation into the cavity between the actuator and the separating layer. This process reduces the pressure in the at least one cavity in the cover layer; in a preferred embodiment, this process generates a negative pressure in the at least one cavity in the cover layer. The change in pressure causes the cover layer to arch in the direction of the actuator above the at least one cavity in the cover layer, with the result that a cavity is formed on the surface of the cover layer. It is also possible for the cover layer to have a number of cavities which adjoin an actuator and are connected to it by a number of perforations.

In one embodiment of the invention, the perforations of the separating layer are filled with a gaseous or a liquid medium. The perforations are preferably filled with a medium that extends the service life and durability of the actuators. The perforations are particularly preferably filled with a gaseous medium, very particularly preferably with air. In one embodiment of the invention, the perforations are filled with a gaseous medium which is at atmospheric pressure when the actuators are adjacent to the perforations.

If the cover layer has at least one cavity which is connected to at least one actuator through at least one perforation, then the cavity and the perforations adjacent to it are filled with a liquid or gaseous medium. The at least one cavity in the cover layer and the at least one adjoining perforation are particularly preferably filled with a gaseous medium, very particularly preferably with air. In one embodiment of the invention, the at least one cavity in the cover layer and the at least one adjacent perforation are filled with a gaseous medium which is at atmospheric pressure when the actuators are adjacent to the at least one perforation.

Since each actuator can be controlled individually, a cavity is formed by applying a voltage to a precisely defined actuator, corresponding to a precisely defined position on the cover layer. The actuators are preferably distributed in the pressure body in such a way that cavities can be formed essentially on the entire surface of the pressure body. This has the advantage that the entire surface of the printing body can be used for printing on a printing material. According to the invention, each actuator is therefore able to form a cavity on the surface of the cover layer.

In a preferred embodiment of the invention, the cover layer is set up to form a multiplicity of cavities for receiving a print medium, with each actuator being able to form at least one cavity.

If the actuator experiences an expansion in the transverse direction, for example when using some piezoelectric actuators, this expansion in the transverse direction is buffered by the material of the pressure body. In this case, the material of the pressure body preferably has elastic properties in order to ensure this.

In a further embodiment of the invention, the actuator is embedded in a cylindrical channel in the pressure body. The cylindrical channel offers enough space to accommodate the expansion of the piezo actuator.

According to the invention, the cover layer has a material which can be deformed by external forces. In one embodiment of the invention, the cover layer has at least one elastomer. The cover layer can include, among other things, a permanently elastic film made of an elastomer or consist of such a film. In particular, the material can be deformed directly or indirectly by deforming a piezoelectric actuator. According to the invention, indentations in the form of cavities can thus be formed on the surface of the cover layer. The cavities represent depressions in the cover layer, which are designed in such a way that they can accommodate a print medium. The top layer has a height of between 30 μm and 150 μm, preferably between 40 μm and 120 μm, particularly preferably between 50 μm and 100 μm.

By controlling the voltage applied to the actuator, the strength of the mechanical deformation of the piezo actuator or the degree of opening of the valve is determined. The greater the voltage applied, the greater the mechanical deformation of the piezo actuator or the greater the degree of opening of the valve. This also determines the volume of the cavity that occurs between the actuator and the separating layer. The depth and thus also the volume of the cavities formed can therefore be influenced by controlling the voltage at the actuators. In this embodiment, the volume of a cavity formed is equal to the scoop volume of the cavity for a pressure medium. In general, the scoop volume of a cavity is the volume of printing medium that a cavity absorbs when a printing medium is applied to the printing form.

In a particularly preferred embodiment of the invention, the cavities are designed as cups, as are known from conventional gravure printing. The cups are also used to hold a print medium in a printing process.

According to the invention, the voltage applied to the actuators can be controlled. In principle, two states can be generated first. In the first state, the voltage applied to one or more actuators is zero, so no deformation of the piezo actuators is caused at these positions or the valves remain closed and the cover layer of the printing form is not deformed at these positions, i.e. no cavities are formed. In the second state, a voltage is applied to one or more actuators, causing the piezo actuators to deform at these positions or the valves are opened to a defined degree and the top layer is deformed accordingly. According to the invention, the deformation takes place in such a way that cavities are formed at the corresponding positions on the cover layer of the printing form. The strength of the applied voltage also controls the strength of the deformation of the piezo actuators or the degree of opening of the valves, so that deeper cavities are formed at higher voltages than at lower voltages. The volume of the cavities and thus their scoop volume can thus be controlled according to the invention by controlling the strength of the applied voltage.

In this way, the brightness values in a print pattern can advantageously be taken into account since, depending on the depth of the cavity, the scoop volume of the cavity can be varied and thus different amounts of print medium can be accommodated in the cavity. In conventional gravure printing, this is done in an analogous way by engraving cells with different depths. Advantageously, in the device according to the invention, the depth and thus the volume of each cavity can be changed between two printing processes without having to convert the printing form. This is not possible in conventional gravure printing due to the engraving of the printing form. Here a new Ballard skin with a modified engraving has to be laboriously applied to the pressure hull.

In one embodiment of the invention, the printing form is therefore set up so that the depth and thus the volume of the cavities can be adjusted via the voltage applied to the actuators.

In one embodiment of the invention, the cavities on the surface of the cover layer have a depth in the range from 2 μm to 100 μm, preferably in the range from 2 μm to 80 μm, particularly preferably in the range from 2 μm to 80 μm.

The cavities generally have a round shape on the surface of the cover layer and are cylindrical in depth. Cavities can be formed with a curved or even with a flat bottom. Since the shape of the cavities also affects their volume, cavities with different scoop volumes can be produced analogously to conventional gravure printing by controlling the depth and/or shape of the cavities. As already described, the scoop volume is the same as the volume of the cavity.

In the context of the present invention, the shape of the cavity describes both the shape of the cavity when the cover layer is viewed from above and the shape of the cavity when the cover layer is viewed in cross section.

In one embodiment of the invention, cavities with a variable shape and/or depth are formed in the cover layer.

In one embodiment, the cover layer has areas that are not directly connected to an actuator. These areas of the cover layer cannot be deformed, and consequently no cavities can be formed at these points. Those areas preferably serve as webs between the cavities that can be formed on the cover layer. Webs represent the non-printing areas of the printing form and are known from conventional gravure printing, where they also serve to delimit adjacent cavities. The bars can stabilize the top layer of the printing form and thus make it easier to remove excess ink with a squeegee. In one embodiment of the invention, the areas of the cover layer that serve as webs have a material that cannot be deformed. In a further embodiment of the invention, no actuators are arranged below the areas of the cover layer that serve as webs.

• die Deckschicht (42) eine Vielzahl von Kavitäten (60, 61) aufweist, wobei jede Kavität (60, 61) mindestens einen Kanal (120, 121) aufweist;
• mindestens eine Perforation (111, 112) der Trennschicht (110) an mindestens einen Kanal (120, 121) einer Kavität (60, 61) in der Deckschicht (42) angrenzt; und mindesten ein Aktor an die mindestens eine Perforation der Trennschicht angrenzt.

In a further embodiment, the device according to the invention is further characterized in that

• the cover layer (42) has a multiplicity of cavities (60, 61), each cavity (60, 61) having at least one channel (120, 121);
• at least one perforation (111, 112) of the separating layer (110) adjoins at least one channel (120, 121) of a cavity (60, 61) in the cover layer (42); and at least one actuator is adjacent to the at least one perforation of the separating layer.

In this embodiment of the invention, it is possible to control the scoop volume of cavities on a printing form and thus to enable printing on a printing material.

According to the invention, the cover layer in this embodiment has a large number of cavities, with the cavities being able to have any cell shape known from gravure printing and thus also any known suction volume. In one embodiment, all the cavities have the same shape; in another embodiment, the cavities can have different shapes. Each cavity of the cover layer has at least one channel, with at least one perforation of the separating layer being attached to at least one channel in such a way adjacent that the exchange of a gaseous or liquid medium between the at least one channel and the at least one perforation is made possible. In one embodiment, multiple perforations of the release liner are adjacent to a channel. In one embodiment of the invention, each cavity has more than one channel. The cavities can be engraved into the cover layer, for example. Individual cavities are advantageously separated from one another by webs. The cover layer in this embodiment may comprise a material or combination of materials known for Ballard gravure skins.

According to the invention, at least one actuator is also adjacent to the at least one perforation of the separating layer. It is also possible that the at least one actuator is adjacent to more than one perforation of the separating layer, these perforations in turn being adjacent to at least one channel of at least one cavity.

• eine Spannung an mindestens einem Aktor angelegt wird;
• Druckgas aus dem Druckkörper in die mit dem mindestens einen Aktor verbundene mindestens eine Kavität (60, 61) entweicht;
• ein Druckmedium (100) auf die Druckform aufgebracht wird; und
• das Schöpfvolumen der mindestens einen Kavität (60, 61) durch den Volumenstrom des ausströmenden Druckgases gesteuert wird.

In one embodiment, the pressure body can also have a compressed gas, with the device being set up such that

• a voltage is applied to at least one actuator;
• Compressed gas escapes from the pressure body into the at least one cavity (60, 61) connected to the at least one actuator;
• a printing medium (100) is applied to the printing form; and
• the scoop volume of the at least one cavity (60, 61) is controlled by the volume flow of the outflowing compressed gas.

According to the invention, the pressure body in this embodiment has a compressed gas. This is arranged inside the pressure hull and is routed to the multiplicity of actuators via suitable lines. In one embodiment of the invention, the compressed gas is located in one or more suitable reservoirs. The compressed gas is advantageously refilled through a supply line into the pressure hull, so that losses of the compressed gas in the pressure hull can be compensated.

If piezo actuators are used as actuators, the lines of the compressed gas are arranged in such a way that compressed gas can escape into the cavity that is created between the piezo actuator and the separating layer when a piezo actuator is deformed by the application of a voltage. According to the invention, at least one compressed gas line opens out at each resulting cavity. In a further embodiment, several compressed gas lines open out at each resulting cavity.

If a voltage is now applied to a piezo actuator, it deforms and forms a cavity between the piezo actuator and the separating layer. A compressed gas flows into this cavity through the at least one compressed gas line that opens into the cavity. Since the hollow space is connected to at least one channel of a cavity by at least one perforation, the compressed gas flows through the at least one perforation and the at least one channel into the cavity.

According to the invention, the volume flow of the outflowing compressed gas can be controlled in several ways.

On the one hand, the compressed gas lines can be arranged in such a way that several compressed gas lines open out at a piezo actuator. The compressed gas lines can then be arranged along the piezoelectric actuator in such a way that as the deformation of the piezoelectric actuator increases, more compressed gas lines can release compressed gas into the cavity which is becoming larger. Thus, with increasing deformation of the piezo actuator, more compressed gas gets into the cavity, which leads to an increase in the volume flow through the channel into the cavity. Since the magnitude of the deformation of the piezo actuator can be controlled by the applied voltage, the volume flow through the channel into the cavity can also be controlled by the applied voltage in this case.

• eine Spannung an mindestens einem Aktor angelegt wird;
• Druckgas aus dem Druckkörper in die mit dem mindestens einen Aktor verbundene mindestens eine Kavität (60, 61) entweicht;
• ein Druckmedium (100) auf die Druckform aufgebracht wird; und
• das Schöpfvolumen der mindestens einen Kavität (60, 61) durch den Volumenstrom des ausströmenden Druckgases gesteuert wird.

In one embodiment, the pressure body can also have a compressed gas and at least one compressed gas line (130, 131, 132), the device being set up such that

• a voltage is applied to at least one actuator;
• Compressed gas escapes from the pressure body into the at least one cavity (60, 61) connected to the at least one actuator;
• a printing medium (100) is applied to the printing form; and
• the scoop volume of the at least one cavity (60, 61) is controlled by the volume flow of the outflowing compressed gas.

It is also possible for a cavity to have multiple channels and for these channels to be assigned to different piezo actuators through different perforations in the separating layer. According to the invention, the piezo actuators can all be electrically controlled independently of one another. It can thus be controlled through how many channels of a cavity compressed gas escapes, which in turn leads to a control of the gas volume flow into a cavity.

According to the invention, the volume flow of the compressed gas into a cavity can be controlled by one of the options described or by a combination of these.

If the actuators have valves, the lines are arranged such that pressurized gas can escape into at least one adjacent perforation of the separating layer when the valve is open. The compressed gas enters the cavity via the perforation and the adjacent channel. The volume flow of the compressed gas can be controlled by controlling the degree of opening of the valve. As already described, the degree of opening of the valve can be controlled by the applied voltage.

In a further embodiment of the invention, a uniform, constant overpressure is present in the pressure body. For this purpose, the pressure body is at least partially filled with a gas, such as air, which has overpressure. The actuators are arranged in such a way that applying a voltage to an actuator creates a cavity between the actuator and the separating layer, into which the gas can escape from the pressure hull. The gas is advantageously refilled through a feed line into the pressure hull, so that losses of gas in the pressure hull can be compensated and the overpressure can be maintained constantly.

The device is also set up so that a printing medium is applied to the printing form. Each cavity of the cover layer has a defined volume, which represents the maximum volume of the cavity. According to the invention, the scoop volume of a cavity can be controlled by the volume flow of the outflowing compressed gas. This means that the more compressed gas flows into the cavity while the pressure medium is being applied to the printing form, the less pressure medium can be accommodated by the cavity and the smaller the scoop volume of this cavity. The outflowing compressed gas displaces the pressure medium when it is applied. According to the invention, it is possible for the volume flow of the compressed gas to be so great that no pressure medium at all is received by a cavity when the pressure medium is applied to the printing form. By controlling the volume flow of the compressed gas in a cavity, it is thus possible to control its scoop volume. The limits here are a scoop volume of zero, at which no pressure medium is taken up into the cavity, and the maximum scoop volume, which corresponds to the volume of the cavity. A cavity can absorb the maximum scoop volume if such a voltage is applied to each actuator connected to this cavity that no compressed gas flows into the cavity.

Since, according to the invention, each actuator can be addressed electrically independently of all other actuators, it is possible to control the scoop volume of each cavity independently of the other cavities of the printing form.

In this embodiment of the invention, the compressed gas is preferably a gas or a gas mixture. The compressed gas is particularly preferably a gas which has no health risk potential. In a preferred embodiment, the compressed gas is air.

After the print medium has been picked up, excess print medium is removed with a squeegee, during which time the control of the individual piezo actuators remains unchanged for the control during the application of the print medium. This prevents unwanted quantities of pressure medium from penetrating into the cavities. During the application of the printing medium to a printing material, the tension on all actuators is then controlled in such a way that no more compressed gas gets into the cavities. The compressed gas thus does not affect the application of the printing medium to a printing material.

• die Deckschicht (42) eine Vielzahl von Kavitäten (60, 61) aufweist, wobei jede Kavität (60, 61) mindestens einen Kanal (120, 121) aufweist;
• mindestens eine Perforation (111, 112) der Trennschicht (110) an mindestens einen Kanal (120, 121) einer Kavität (60, 61) in der Deckschicht (42) angrenzt;
• mindesten ein Aktor an die mindestens eine Perforation der Trennschicht angrenzt;
• und das die Vorrichtung weiterhin ein Sleeve aufweist, welches auf der Deckschicht angeordnet ist.

In a further embodiment, the device according to the invention is further characterized in that

• the cover layer (42) has a multiplicity of cavities (60, 61), each cavity (60, 61) having at least one channel (120, 121);
• at least one perforation (111, 112) of the separating layer (110) adjoins at least one channel (120, 121) of a cavity (60, 61) in the cover layer (42);
• at least one actuator is adjacent to the at least one perforation of the separating layer;
• and that the device further comprises a sleeve which is arranged on the cover layer.

In this embodiment, the device has a sleeve which is arranged on the cover layer and completely covers it. According to the invention, the sleeve thus also covers the cavities that are present in the cover layer. Furthermore, the sleeve preferably has a material from the group containing plastics, natural latex, natural rubber and smart materials, with the material being elastically deformable. Smart materials are materials that have one or more properties that can be controlled by external stimuli. Such stimuli can be, for example, electric or magnetic fields, pH, temperature or pressure. According to the invention, the sleeve has a height of between 1 μm and 100 μm, preferably between 2 μm and 30 μm, particularly preferably between 3 μm and 10 μm.

If the actuator is designed as a piezo actuator and this is adjacent to the separating layer, ie is not deformed, the at least one adjacent cavity, each adjacent channel and the adjacent perforations form a closed space. The same applies if the actuator has a valve and this is closed. A gaseous or a liquid medium can be located in this closed space. According to the invention, the medium in the space has a suitable pressure in order to shape the sleeve in such a way that the underlying cavity is covered in such a way that no pressure medium can be accommodated at this position.

If the actuators are in the form of piezo actuators and if a voltage is applied to a piezo actuator, the piezo actuator deforms as a result and a cavity is created between the piezo actuator and the separating layer. If the actuators have valves or valves with nozzles, the valves are designed in such a way that opening the valves also creates a cavity between the valve and the separating layer.

According to the invention, at least one perforation of the separating layer adjoins the cavity in such a way that the exchange of a gaseous or liquid medium between the cavity and the perforation is made possible. According to the invention, a medium that is located in the adjacent perforations of the separating layer, the adjacent channels and the adjacent cavity can therefore penetrate into the cavity. The pressure in the cavity is reduced as a result of this process; in a preferred embodiment, a negative pressure is generated in the cavity as a result of this process. Due to the change in pressure, the sleeve lying over the cavity is deformed towards the actuator. If the negative pressure is high enough, the sleeve forms the cavity underneath completely and the cavity with the sleeve as the surface can absorb the maximum volume of a print medium. By controlling the strength of the negative pressure, the strength of the deformation of the sleeve over a cavity can be controlled and thus the suction volume of the cavity with the sleeve as the surface.

If the actuators are controlled in such a way that the valve closes or the piezo actuator is no longer deformed, there is no longer any negative pressure, the sleeve is not deformed and completely covers the cavity. This can then take up no pressure medium accordingly. This allows flexible adjustment of the scoop volume of the cavities to print templates.

The magnitude of the negative pressure is controlled by the voltage applied to the actuators, which controls either the degree of deformation of the piezo actuator or the degree of opening of the valve. Both have an effect on the volume of the resulting cavity between the separating layer and the actuator and thus directly on the size of the resulting negative pressure.

In a further embodiment of the invention, the cover layer has a multiplicity of cavities, the cover layer also having at least one cavity which is connected to at least one actuator through the perforations of the separating layer and the at least one actuator being arranged in such a way that the actuator Scoop volume controls at least one cavity.

The at least one cavity in the cover layer is arranged below a cavity and can accommodate a gaseous or liquid medium. If there is no medium in the cavity, it is compressed by the overlying cover layer in such a way that a cavity is present at this position on the cover layer. In one embodiment of the present invention, there is a cavity below each cavity in the top layer.

The actuator is connected to the cavity in the cover layer via at least one perforation in the separating layer. In this embodiment, the actuator has at least one valve and a reservoir for a liquid or gaseous medium. Suitable media are e.g. gases such as air, gas mixtures, liquids or oils. Furthermore, the actuator has a suitable device which can press the medium through the at least one valve into the adjoining perforations of the separating layer or which sucks the medium out of the cavity and the perforation back into the reservoir. The device preferably has a controller that can be controlled by an applied voltage. The device is preferably controlled together with the at least one valve. Such a device can be, for example, a piston running in a cylinder, with part of the cylinder representing the reservoir for the gaseous or liquid medium.

When the valve is open, the medium is pressed into the cavity in the top layer that borders the perforations. As a result, the cover layer above the cavity is deformed in such a way that the suction volume of the cavity located above the cavity is reduced. When the cavity is filled to its maximum, the suction volume of the cavity above is zero. The degree of filling of the cavity is controlled by controlling the degree of opening and the opening time of the valve in the actuator and by controlling the device certainly. This makes it possible to flexibly adjust the degree of filling of the cavity and thus also the scoop volume of the cavities.

Conversely, with appropriate control, the piston can be moved in such a way that the medium is sucked out of the cavity into the reservoir. In this case, as already described, the cavity is compressed by the overlying cover layer and the cavity on the surface of the cover layer assumes the greatest possible volume.

In all of the described embodiments of the invention, the suction volume of the cavities on the cover layer can thus be controlled. In this way, the brightness values in a print pattern can advantageously be taken into account, since the quantities of the print medium that is accommodated in a cavity can be controlled depending on the scoop volume of the cavity. In conventional gravure printing, this is done in an analogous way by engraving cells with different depths. Advantageously, in the device according to the invention, the scoop volume of each cavity can be changed between two printing processes without having to convert the printing form. This is not possible in conventional gravure printing due to the engraving of the printing form. Here a new Ballard skin with a modified engraving has to be laboriously applied to the pressure hull.

For example, when printing an image, the scoop volume is determined by the gray levels in the color separation data. The larger the scoop volume, the more printing medium is applied to the substrate. In one embodiment, the scoop volume of the individual cavities required for the printing process is therefore determined as a function of the gray levels of a print pattern or the separation data created from the print pattern. The suction volume of the cavities is then adjusted as described via the voltage applied to the actuators.

The present invention advantageously provides a printing form which has the same resolution of cavities as is possible in conventional gravure printing by engraving small cells.

A typical roller used in conventional gravure printing has a screen with a screen width of 60 lpi, ie 60 lines per cm. For example, this results in 8,400 cavities in width and 7,800 cavities in circumference for a device according to the invention with a roller with a width of 140 cm and a circumference of 130 cm as the pressure body. That is, according to the invention are on the entire cover layer of the roll either 8,400 ^* 7,800=65,520,000 cavities are formed or can be formed according to the invention. As a result, the actuators are distributed in such a way that 65,520,000 grid points are available that can be controlled individually. If a roller with a width of 60 cm and a circumference of 40 cm is used at 60 lpi, this results in 3,600 cavities in width and 2,400 cavities in circumference. In this case, according to the invention, 3,600 ^* 2,400=8,640,000 cavities are formed on the entire cover layer of the roll or can be formed according to the invention. The actuators are distributed in such a way that 8,640,000 grid points are available, which can be controlled individually.

In one embodiment of the invention, the device is set up to form cavities with a grid width in the range from 10 lpi to 80 lpi, preferably in the range from 30 lpi to 70 lpi, particularly preferably with 60 lpi, or has cavities with the stated grid widths.

In one embodiment of the present invention, the printing form also has a sensor. The sensor is capable of accurately determining a position of the circumference of the roll. With the help of the sensor, it is advantageously possible to determine precisely at which point on the circumference of the roller it is currently printing.

The device according to the invention also has a device for dispensing a pressure medium. The device for dispensing a print medium preferably has a container with a squeegee or lines for transporting the print medium.

In one embodiment of the invention, the device for dispensing a print medium has a container with a squeegee. In this case, the container contains the printing medium and the printing form dips into the printing medium in the container, so that the cavities on the cover layer of the printing medium are completely flooded with the printing medium. The squeegee then removes the excess printing medium so that there is only printing medium in the cavities, but the cover layer between the cavities is free of printing medium. The use of a container with a squeegee is particularly advantageous if the pressure body is a cylinder. Embodiments of squeegees are known from the prior art, for example, the squeegee can be designed in the form of a steel ruler. However, squeegees made of elastic or soft materials that are suitable for scraping off powder are also known. Suitable elastic materials are, for example, felt, rubber or other plastics.

In a further embodiment, the device for dispensing a pressure medium has a container with an air curtain. In this case, the container contains the printing medium and the printing form dips into the printing medium in the container, so that the cavities on the cover layer of the printing medium are completely flooded with the printing medium. The excess pressure medium is then removed by the air curtain.

The embodiments in which the device for dispensing a printing medium has a container with a squeegee or a container with an air curtain are particularly advantageous if the printing forme has a pressure roller as the pressure body.

In a further embodiment, the device for dispensing a print medium has at least one application roller and one doctor blade. The print medium is applied to the printing form with the at least one applicator roller and the excess print medium is then removed with the aid of the at least one doctor blade. This embodiment is particularly advantageous if the printing form has a printing plate as the printing body.

In a further embodiment of the invention, the device for delivering a pressure medium has lines for transporting the pressure medium. The lines advantageously run through the printing body and end in the cover layer of the printing form in the areas in which cavities can be formed. The lines are positioned so that each cavity formed on the cover layer can be filled with pressure medium. In this embodiment, the cavities can advantageously be filled from the inside of the pressure body. The lines are connected to respective reservoirs containing print media. The cavities can be filled in a targeted manner using suitable pumping and control devices. These devices and their use are known to those skilled in the art.

According to the invention, the printing medium has at least one pigment-containing liquid or at least one functional material.

Advantageously, the present invention makes it possible to use all print media used in conventional gravure printing. Thus, in one embodiment, print media may be pigment-containing inks suitable for gravure printing. This also includes special colors and mixed colors. According to the invention, pigment-containing liquids can also be pigment-containing lacquers, for example acrylic lacquers or PU lacquers.

In a further embodiment of the invention, the print medium can have functional materials.

In one embodiment of the invention, powder or fibers can serve as the functional material. These can be used, for example, to create 3D structures on a substrate. All materials used in conventional 3D printing can be used. These are known to those skilled in the art.

In a further embodiment of the invention, the functional materials can be incorporated into a liquid, for example into an ink. In one embodiment, the liquid only serves to distribute the functional materials more homogeneously and evaporates after application or can be removed after application.

In one embodiment of the invention, the print medium has functional materials that are conductive. These functional materials can be selected from the group containing soot, carbon fibers, metal powder, salts, alloys, nanoparticles, in particular carbon nanotubes and conductive polymers such as polypyrroles. Combinations of these substances can also be used.

In one embodiment of the invention, the print medium has functional materials in the form of organic and/or inorganic coloring pigments, the pigments containing at least one substance or at least one composition of substances whose color can be changed by changing a physical variable acting on the pigments. Such substances or substance compositions can be hydrochromic, piezochromic, photochromic, thermochromic or phosphorescent dyes. In this way, it is possible to change the color of the print on the printing material and the elements produced from it, for example for floor coverings, wall and/or ceiling coverings, by changing the moisture content, the temperature or the pressure.

The printing medium can also have a binder as a functional material, in which case the binder can be either an inorganic or an organic agent or a mixture thereof. Binders containing synthetic resin are often used.

In one embodiment of the invention, the print medium has functional materials that are suitable for printing electronic components. Both organic and inorganic materials are used for printed electronics. These materials lie preferably in liquid form, ie as a solution, dispersion or suspension. This applies in particular to many organic functional materials that are used as conductors, semiconductors or insulators. As a rule, the inorganic materials are dispersions of metallic micro- or nanoparticles. Suitable nanoparticles can, for example, have a conductive coating on a non-conductive core. The most common materials used in printed electronics are the conductive polymers poly-3,4-ethylenedioxythiophene doped with polystyrene sulfonate, polypyrrole and polyaniline. Both polymers are commercially available in various formulations. Alternatively, silver, gold and/or copper nanoparticles are used. In addition to polymer and metallic materials, this technology is also focusing on carbon as a robust material for printed electronic applications. Numerous polymer semiconductors are processed in inkjet printing. Examples of polymeric semiconductors are polythiophenes such as poly(3-hexylthiophene) and poly-9,9-dioctylfluorencobithiophene. Printable organic and inorganic insulators or dielectrics exist in large numbers.

Furthermore, the print medium can have functional materials in the form of phase change materials. Phase change materials are materials whose latent heat of fusion, solution or absorption is significantly greater than the heat they can store due to their normal specific heat capacity, i.e. without the phase change effect. Among other things, these materials are suitable for generating latent heat storage devices.

In a further embodiment, the print medium can have luminous pigments in the form of electroluminophores or luminescent substances as the functional material. Electroluminophores are pigments that can be excited to luminescence by an alternating electric field. A suitable electroluminophore is, for example, zinc sulfide doped with various metals such as manganese (ZnS:Mn), gold, silver, copper or gallium. Fluorescent and/or phosphorescent substances on an inorganic or organic basis, in particular zinc sulfide and alkaline earth metal aluminates, are also preferably used as luminescent substances.

The print medium can have monocrystalline materials as the functional material, which can serve as piezoelectric sensors. Monocrystalline materials such as quartz, tourmaline and gallium phosphate are preferred.

Furthermore, the print medium can have abrasion-resistant particles, natural fibers, synthetic fibers and/or flame retardants as functional material. In one embodiment, resins such as melamine-formaldehyde resin or urea-formaldehyde resin, acrylate and polyurethane resins can be used as suitable binders. These types of functional materials are suitable for applying a protective layer to a substrate. In one embodiment, the functional materials can be pigment-containing or pigment-free paints that are preferably cured by means of high-energy radiation, e.g. by UV or electron beam curing. In a further embodiment of the present invention, the functional material has or consists of a resin.

The abrasion-resistant particles are preferably selected from the group containing aluminum oxides, corundum, boron carbides, silicon dioxides, silicon carbides and glass particles. In particular, fibers selected from the group containing wood fibers, cellulose fibers, wool fibers, hemp fibers and organic or inorganic polymer fibers are used as natural and/or synthetic fibers. For example, a mixture of conventional silanized corundums with different grain sizes is used as the corundum.

Phosphates, borates, in particular ammonium polyphosphate, tris(tribromoneopentyl)phosphate, zinc borate or boric acid complexes of polyhydric alcohols are preferably used as flame retardants.

According to the invention, the device has at least one device for control. In one embodiment of the invention, the at least one control device is a PC, a tablet or another data-processing device. The control device is set up in such a way that it controls the voltage at the actuators. The print pattern to be printed on the substrate is stored on the PC, tablet or data processing device and the voltage on the actuators is controlled depending on the color values of the print pattern. In one embodiment, depending on the voltage at the actuators, cavities with a controlled scoop volume are formed on the top layer of the printing form in such a way that the print pattern can be imaged on the printing material. In a further embodiment, the suction volume of the cavities on the cover layer is controlled by volume flows of a compressed gas depending on the voltage at the actuators in such a way that the print pattern can be imaged on the printing material.

If a multicolored print pattern is printed, the control device is preferably able to generate a digital separation file for the different colors of the to create a print pattern. The voltage on the actuators is then controlled accordingly in such a way that the cavities on the top layer have a volume that is suitable for imaging the print pattern in accordance with the separation files.

If the device for discharging a printing medium has lines for transporting the printing medium, the data for discharging the printing medium are also transmitted from the device for controlling the device for discharging a printing medium. Thus, it is possible to control the amount and type of print medium that is delivered to the respective cavities.

The device according to the invention also has at least one device for data transmission. In one embodiment of the invention, the device for data transmission has at least two transmitter/receiver devices that are set up to transmit data without contact. Suitable transmitter/receiver devices are set up to both send and receive data in a contactless manner. According to the invention, a transmitter/receiver device is connected to the control device, and another transmitter/receiver device is located on the printing form. It is thus possible to transmit information from the control device to the actuators and vice versa. Contactless data transmission is possible, for example, using WLAN, Bluetooth or similar methods. According to the invention, contactless data transmission also includes contactless optical data transmission. This is possible, for example, via optical fibers. Contactless data transmission has the advantage that data transmission can be guaranteed without any problems even at high speeds and that this type of data transmission is largely characterized by being wear-free.

In a further embodiment of the invention, the device for data transmission has at least one contact. In a preferred embodiment, this contact is a slip ring transmitter. Slip ring transmitters are already known from the prior art and are used to transmit information on rotating elements. A slip ring transmitter is preferably used when the pressure body is a cylinder. The slip ring transmitter is then positioned in such a way that it can transmit information from the control device to the printing form and vice versa.

Irrespective of the form of data transmission, all actuators are networked for the purpose of data transmission. Some of the actuators are each connected to a central network via an intermediate network. The crosslinking takes place according to the invention electronic connections such as lines, printed circuit boards and/or conductor foils. The central network ends in at least one contact or in at least one transmitter/receiver device.

If the device for delivering a print medium has lines for transporting the print medium, in one embodiment of the invention there is also a transmitter/receiver device on the device for delivering a print medium. It is thus possible to transmit information from the control device to the device for dispensing a print medium and vice versa. In a further embodiment of the invention, the device for dispensing a print medium is connected to the device for control via a data cable.

In a further embodiment of the invention, the device according to the invention has a number of contacts or a number of transmitter/receiver devices. In this case the printing form has, for example, two, three or four contacts or transmitter/receiver devices. In this way it can be ensured that the data transmission can also be carried out with an increased data volume.

In one embodiment of the invention, the device for data transmission has at least two transmitter/receiver devices that are set up to transmit data without contact and/or the device for data transmission has at least one contact. A combination of the devices for data transmission is possible according to the invention.

The device according to the invention provides a printing form in which the scoop volume of the cavities of the cover layer can be controlled. This makes it possible to change the arrangement of printing (cavities with a suction volume not equal to zero) and non-printing areas (cavities with a suction volume of zero) without changing the top layer of the printing form. In comparison to conventional gravure printing, the production of at least one engraved static printing form for each printing pattern, as well as their changing and storage in the printing process, is advantageously omitted. The device according to the invention therefore enables the use of one printing form for any number of printing patterns.

In addition, it is possible to change the scooping volume of the cavities in the device according to the invention immediately after a printing process has been carried out. For this purpose, according to the invention, the printing form has a sensor that is suitable for precisely determining a position of the to determine the circumference of the roll. With the help of the sensor, it is possible to determine exactly at which point on the circumference of the roller it is currently printing. In this way, the scooping volume of the cavities can be changed after a printing process has taken place on the roller. As the printing process progresses, the cavities can therefore continuously map other print points in the print pattern.

The present invention therefore makes it possible to print digital print patterns on printing materials that have a longer print data length than the circumference of the roller. Compared to conventional gravure printing, this offers the advantage that the circumference of a printing roller can be selected independently of the length of the print data or the length of a repeat of a print pattern. This means that it is no longer necessary to provide rollers with different circumferences in production in order to print print samples with different print data lengths. Conversely, the print data length that can be printed is no longer dependent on the existing rollers. Any length of print data can be printed with one roller with the present invention. This offers an enormous economic advantage and an enormously increased flexibility compared to conventional gravure printing devices.

The features of the device according to the invention also apply to the methods according to the invention described below and vice versa.

• eine Spannung an jedem Aktor angelegt wird, an dessen Position eine Kavität an der Oberfläche der Druckform entstehen soll; und
• durch die angelegte Spannung die Deckschicht verformt wird und dadurch an dieser Position eine Kavität an der Oberfläche der Druckform gebildet wird.

Furthermore, a method for producing a multiplicity of cavities on a printing form by means of a device according to one of claims 1 to 3 is the subject matter of the present invention. The printing form comprises a printing body, a large number of actuators, a separating layer with a large number of perforations and a cover layer. Each actuator can be electrically addressed independently of the other actuators via a controller. The method is characterized in that

• a voltage is applied to each actuator at the position of which a cavity is to be created on the surface of the printing form; and
• the top layer is deformed by the applied voltage and a cavity is thereby formed on the surface of the printing form at this position.

In one embodiment of the invention, the depth and thus the scoop volume of a cavity is controlled by the strength of the voltage applied to the associated actuator. The applied voltage controls the volume of the cavity that is created between the actuator and the separating layer and thus the size of the negative pressure and the strength of the deformation the top layer. The depth and thus the volume of the cavity formed is also influenced accordingly.

In one embodiment of the invention, as described, the method according to the invention allows cavities of different depths and different shapes to be formed on the cover layer. If the cavities are designed as cells for gravure printing, it is in principle possible to design all cell shapes and cell depths that are known from conventional gravure printing.

In one embodiment of the invention, cavities are formed in the form of cups, which are preferably circular, with a diameter of 0.05 to 0.15 mm, particularly preferably with a diameter of 0.1 mm. Circular in this context refers to the shape of the cells when the top layer is viewed from above. The shape of the cells, viewed in cross section of the cover layer, can be of any design.

In one embodiment of the invention, the cover layer has webs that influence the shape of the cavities. Since the webs are not deformable, their shape can influence the shape of the cavities that are formed.

• eine Spannung an mindestens einem Aktor angelegt wird;
• Druckgas aus dem Druckkörper durch den Kanal in die mit dem mindestens einen Aktor verbundene mindestens eine Kavität entweicht oder ein Medium in einen Hohlraum in der Deckschicht eingebracht wird oder das Sleeve durch Druck verformt wird;
• ein Druckmedium auf die Druckform aufgebracht wird;
• wobei das Schöpfvolumen der mindestens einen Kavität durch den Volumenstrom des ausströmenden Druckgases oder durch das Volumen des in den Hohlraum strömenden Mediums oder durch die Größe des Drucks mit dem das Sleeve verformt wird, gesteuert wird.

The invention also includes a method for controlling the scoop volume of cavities on a printing form by means of a device according to one of Claims 4 to 8, wherein each actuator can be electrically addressed independently of the other actuators via a controller, characterized in that

• a voltage is applied to at least one actuator;
• Compressed gas escapes from the pressure body through the channel into the at least one cavity connected to the at least one actuator, or a medium is introduced into a cavity in the cover layer, or the sleeve is deformed by pressure;
• a printing medium is applied to the printing form;
• wherein the scoop volume of the at least one cavity is controlled by the volume flow of the outflowing compressed gas or by the volume of the medium flowing into the cavity or by the magnitude of the pressure with which the sleeve is deformed.

• die Aktoren elektrisch angesteuert werden, so dass die Kavitäten Schöpfvolumen eines Druckmediums aufnehmen können, die dazu geeignet sind, das digitale Druckmuster auf einem Bedruckstoff abzubilden oder dass auf der Druckform Kavitäten mit Schöpfvolumen ausgebildet werden, die dazu geeignet sind, das digitale Druckmuster auf einem Bedruckstoff abzubilden;
• von der Druckform ein Druckmedium durch eine Vorrichtung zur Abgabe eines Druckmediums aufgenommen wird; und
• das digitale Druckmuster mit der Vorrichtung direkt oder indirekt auf den Bedruckstoff gedruckt wird.

The invention also includes a method for printing a printing material with a device according to one of claims 1 to 10 with a digital print pattern, characterized in that

• the actuators are controlled electrically, so that the cavities can hold a volume of a print medium that is suitable for imaging the digital print pattern on a printing substrate or that cavities with a volume that are suitable for imaging the digital print pattern on a printing substrate are formed on the printing form to depict;
• a print medium is picked up from the printing form by a device for dispensing a print medium; and
• the digital print pattern is printed directly or indirectly onto the substrate with the device.

According to the method for printing a printing material with a device according to the invention, the actuators are first controlled electrically, so that the cavities can accommodate suction volumes of a printing medium that are suitable for imaging the digital print pattern on a printing material or that cavities with suction volumes are formed on the printing form , which are suitable for mapping the digital print pattern on a substrate. For this purpose, the necessary data are transmitted via the device for data transmission to the printing form via the device for control and the voltage at the individual piezo actuators is thus controlled.

The digital print pattern can have a maximum print data width that is as wide as the printing form used. However, a digital print sample with a smaller print data width can also be printed. In one embodiment, in this case, cavities are only formed at the points on the printing form that are necessary for printing the digital print pattern. In a further embodiment, the scoop volume of all cavities that are arranged on the printing form outside of the area required for printing the digital print pattern is controlled in such a way that their scoop volume is zero. This means that these cavities do not contribute to the pressure.

A printing medium is then picked up from the printing form by a device for dispensing a printing medium, ie the cavities formed on the top surface of the printing form are filled with a printing medium. The device according to the invention can therefore also be used more flexibly in this respect than conventional printing devices.

The digital print pattern is then printed directly or indirectly onto a substrate. With direct printing, the print medium is transferred directly from the printing form to a substrate. The method for direct printing is carried out analogously to direct printing in the conventional gravure printing process. In general, in the printing process, a contact pressure is exerted on the printing material by a so-called impression roller, so that the transfer of the printing medium can take place in the printing process. These methods are known to those skilled in the art.

Alternatively, the digital print pattern can also be transferred indirectly to a printing material. Methods for indirect printing are also known from conventional gravure printing and can be used in the present invention. In particular, indirect printing can be carried out using a rubber roller as the transmitter. In this case, the print pattern is transferred to a rubber roller by the device according to the invention and applied to a printing material by the rubber roller.

In a further embodiment of the invention, the print pattern is printed indirectly onto a structured surface. The print pattern is applied to a flexible transfer element by the device according to the invention. The flexible transfer element is guided over a deflection roller and then the print pattern is transferred to the printing material. For this purpose, the flexible transfer element is pressed onto the printing material with a movable counter-pressure roller. The movable counter-pressure roller can adapt to the structuring of the printing material in such a way that a sufficiently large contact pressure prevails at all times during the transfer of the printing medium to the printing material. The contact pressure is sufficient if error-free transfer of the print medium is guaranteed. The movable counter-pressure roller also has an elastic coating such that the flexible transfer element is pressed at least partially into structures on the surface of the printing material, so that error-free transfer of the print medium is ensured. Suitable flexible transfer elements have such an elasticity that they can adapt to structures on the surface of the printing material. By way of example, the flexible transmission element can have a material included in a group comprising foam, rubber, elastomers and textiles.

The screen angling according to DIN 16 547, which is known from the prior art, can also be implemented with the present invention. With screen angles, the primary colors of the CMYK color space are printed one above the other at different screen angles.

The angles of the primary colors are defined in DIN 16 547. The screen angle avoids conspicuously disturbing patterns such as moiré effects or reduces their conciseness.

In one embodiment of the invention, the scoop volume of the cavities on the printing form is changed after the print pattern has been transferred to the printing material. In one embodiment of the invention, this is done by changing the arrangement and/or the volume of the cavities formed. In a further embodiment of the invention, this is done by changing the volume flow of the compressed gas into the cavities. By changing the scoop volume of the cavities, the arrangement of the printing and non-printing areas of the top layer can be changed in every embodiment of the invention. At the same time, the volume of the printing medium is changed, which is taken up by a cavity and thus released onto a printing material. The brightness values in a print pattern can thus advantageously be taken into account

In one embodiment of the invention, the scoop volume of the cavities on the printing form is changed immediately after the printing medium has been transferred to the printing material. In this case, the scoop volume of the cavities and thus the arrangement of the printing and non-printing areas of the top layer can already be changed before the complete print pattern has been printed. This is particularly advantageous when using a roller as a pressure body. In this embodiment, the printing form advantageously also has a sensor with which it can be determined exactly at which position on the circumference of the roller the printing form is currently printing. In this way, the cavities on the cover layer that have already printed can be changed in a targeted manner and those that have not yet printed are left unchanged.

This embodiment is particularly advantageous when using a roller as the printing form, since according to the invention the repeat length of a print pattern is no longer limited to the circumference of the roller or has to be matched to it. The present invention therefore makes it possible to print a much wider range of print patterns than is possible with conventional gravure printing, in which the dimensions of a print pattern are limited by the roll circumference.

According to the invention, therefore, all print patterns that can also be processed with the conventional gravure printing method can serve as digital print patterns. However, the present invention can also be used to print print patterns whose print data length is greater than the roll circumference of the printing form if a roll is used as the print body.

In a preferred embodiment of the invention, the digital print pattern is, for example, a decorative template that is used in the decorative design of laminates for floor, wall and/or ceiling coverings. Any wood, tile, stone, fancy decor or parquet imitations are applied to substrates, particularly in the case of floor laminates. Templates from nature are often used to produce these decors, which are applied to a printing material after digitization or after additional digital processing with software.

• Latentwärmespeicher mit Phasenwechselmaterialien,
• eine Fussbodenheizung auf Basis einer Widerstandsheizung,
• eine Beleuchtung auf Basis von Elektrolumineszenz, wie z.B. zinksulfidische Luminophore,
• Einbruchssensor auf Basis piezoelektrischer Elemente,
• Farbanpassung auf Basis thermochromer Pigmente,
• Unfall-/Einbruchsmelder auf Basis piezochromer Pigmente,
• Feuermelder auf Basis Widerstandsänderung,
• Bindemittel zur Fixierung einer bereits aufgetragenen gedruckten Schicht, das Bindemittel kann dabei vollflächig oder auch nur an bestimmten Stellen des Bedruckstoffes aufgetragen werden,
• Funktionsschichten, die der Datenübertragung bzw. Datenweiterleitung dienen, diese Funktionsschichten können beispielsweise an ein vorhandenes Computernetzwerk angebunden werden.

In a further embodiment, the digital print pattern can also represent one or more functional layers. Functional layers are layers that are applied to a substrate and that primarily bring a functional benefit. Functional layers according to the present invention include, for example

• Latent heat storage with phase change materials,
• underfloor heating based on resistance heating,
• lighting based on electroluminescence, such as zinc sulfide luminophores,
• Intruder sensor based on piezoelectric elements,
• color matching based on thermochromic pigments,
• Accident/intrusion detectors based on piezochromic pigments,
• Fire alarm based on resistance change,
• Binding agent for fixing an already applied printed layer, the binding agent can be applied over the entire surface or only at certain points of the printing material,
• Functional layers that are used for data transmission or data forwarding, these functional layers can be connected to an existing computer network, for example.

Among other things, the known processes for the production of printed electronics are used here. Printed electronics refers to electronic components, assemblies and applications that are completely or partially manufactured using printing processes. Instead of printing inks, electronic functional materials that are in liquid or pasty form are printed. Suitable functional materials have already been described at the outset.

The materials required for producing the functional layer can be incorporated into a liquid. But it is also possible that the ink used for printing itself represents the functional layer. Another possibility is that the liquid only serves to distribute the functional layer more homogeneously and evaporates or can be removed after application.

The design of such functional layers is known to the person skilled in the art and has already been described in the literature.

In principle, any material that is suitable for applying a printing medium is suitable as a printing material. The printing material can have a smooth or a rough surface to which the printing medium is applied. In one embodiment of the invention, the printing material according to the present invention is selected from a group containing paper, glass, metal, foils, wood-based materials, in particular MDF or HDF boards, WPC boards, veneers, lacquer layers, plastic boards, fiber-reinforced plastic, laminated paper and inorganic support plates.

In a preferred embodiment, the printing material has at least one flat shape that can be printed with the printing forms according to the invention. Suitable substrates can therefore be, for example, laminates, furniture boards, furniture fronts, worktops, door fronts, wallpaper, paper and glass surfaces. The printing material can have a smooth surface or else a structured surface. If the printing material has a structured surface, the printing material is preferably printed indirectly. This procedure has already been described at the outset.

In one embodiment of the invention, paper is used as the printing material. Paper suitable as print base paper is preferably white and has a weight of 60 to 90 g/m ² , preferably 65 to 80 g/m ² , particularly preferably 70 g/m ² . Before printing, the paper is primed to prime it. Suitable agents that can be used as primers are known to those skilled in the art.

Printed decors are used, for example, in the production of floor laminate or in the form of wall and ceiling paneling elements. In this case, the printing material is preferably a wooden board. In one embodiment of the present invention, the printing material is a wood-based panel.

In one embodiment of the present method, in particular when using wood-based material boards, at least one primer layer is applied to the side of the wood-based material board to be printed before printing with the digital print pattern applied at least one resin and / or at least one paint, which is then dried and / or partially cured.

The side of the wood-based panel to be printed is preferably sanded before the primer is applied.

In one embodiment of the invention, paper is used as the printing material. Paper suitable as print base paper is preferably white and has a weight of 60 to 90 g/m ² , preferably 65 to 80 g/m ² , particularly preferably 70 g/m ² . Before printing, the paper is primed to prime it. Suitable agents that can be used as primers are known to those skilled in the art.

Printed decors are used, for example, in the production of floor laminate or in the form of wall and ceiling paneling elements. In this case, the printing material is preferably a wooden board. In one embodiment of the present invention, the printing material is a wood-based panel.

In particular when using wood-based panels, in one embodiment of the present method, at least one primer layer comprising at least one resin and/or at least one lacquer is applied to the side of the wood-based panel to be printed before printing with the digital print pattern, which is then partially dried and/or partially cured .

The side of the wood-based panel to be printed is preferably sanded before the primer is applied.

For priming, an aqueous resin solution and/or a radiation-curable filler can be applied to the side of the carrier material to be printed. For example, aqueous resin solutions such as melamine-formaldehyde resin, urea-formaldehyde resin or melamine-urea-formaldehyde resin can be used as primers. It is also possible to pre-coat or prime the carrier material with 1K/2K acrylate, UV and/or ESH putty and then to cure this primer layer accordingly.

An aqueous resin solution is preferably used for the pre-coating or priming of the wood-based panel, which is an aqueous resin solution, in particular an aqueous Solution of a melamine-formaldehyde resin, urea-formaldehyde resin or melamine-urea-formaldehyde resin.

The amount of liquid resin solution applied for priming can be between 10 and 80 g/m ² , preferably 20 and 50 g/m ² . The solids content of the aqueous resin solution is between 30 and 80%, preferably 40 and 60%, particularly preferably 55%. The liquid resin can additionally contain suitable wetting agents, hardeners, release agents and defoamers.

After application of the aqueous resin solution to the wood-based panel for precoating or priming the same, the liquid resin is dried to a moisture content of 10%, preferably 6%, e.g. in a convection oven or near-infrared oven.

In another embodiment of the present method, the wooden board can be precoated or primed with 1K/2K acrylate and/or ESH filler. A UV filler consists advantageously essentially of UV-curable paint components, pigments, reactive diluents and free-radical generators as chain initiators.

In this case, the amount of filler applied can be 50 to 150 g/m ² , preferably 50 to 100 g/m ² . The amounts given refer to a 100% filler.

It is also possible that the filler used for priming is pigmented, which means that the printing result can be varied or improved.

Particularly preferred according to the invention is the pre-coating of the wood-based panel with a transparent primer.

In a further embodiment of the present method, at least one layer of a pigmented primer, which is preferably water-based, is applied to the side of the wood-based panel to be printed before the at least one side of the wood-based panel is printed. The pigmented primer can either be applied directly to the untreated surface of the material panel or to the previous, preferably transparent, primer.

The water-based pigmented primer can also be applied in more than one layer (e.g. 3 to 10 layers, preferably 5 to 8 layers, particularly preferably 7 layers), the pigmented primer being dried after each layer application, for example in a convection dryer or a near-infrared dryer. The water-based pigmented primer preferably contains at least one pigment of a light color, more preferably at least one white pigment.

White pigments are achromatic inorganic pigments with a high refractive index (greater than 1.8), which are mainly used to create optical whiteness in paints or as fillers in e.g. B. plastics can be used. White pigments according to the invention can be selected from the group comprising titanium dioxide, lithopone, barium sulphate, zinc oxide, zinc sulphide and calcium sulphate. Lithopone is a white pigment containing barium sulfate and zinc sulfide. According to the invention, titanium dioxide is preferably used as the white pigment in the water-based pigmented primer, since titanium dioxide has the highest refractive index and thus the highest hiding power among the known white pigments.

The substrate can therefore be primed before printing and one or more protective layers can optionally be applied after printing. A production line that includes the device according to the invention can be used for this purpose.

A production line for printing a printing material with the present invention comprises means for producing a primer, the inventive device for printing the printing material and, in a further variant, at least one means for applying a protective layer to the printing material provided with the respective print. This means or this device for applying a protective layer is preferably arranged downstream of the printing line.

In a preferred embodiment, the production line has at least one short-cycle press for pressing the printing material provided with the print pattern and the protective layer arranged thereon.

In a further embodiment of the invention, the printing material has a structure. With the aid of the indirect printing method already described, such a printing material can be printed with the device according to the invention or with the method according to the invention. In one embodiment of the invention, a printing material that has a structure is printed with the device according to the invention or with the method according to the invention in such a way that the print pattern is synchronous with the structure on the printing material. In this embodiment, for example, a printing material that has a wood-like structure has to be printed with a wood decor in such a way that the wood decor and the underlying structure are synchronous with one another. This means that where there is a knothole in the wood decor, there is also a corresponding structure. This creates an optimal interplay of structure and decor for a user. This embodiment is therefore very popular with customers and is therefore characterized by high economic potential.

In a further embodiment of the present invention, the device according to the invention can be used for the metered application of production materials. Production materials are, for example, corundum and/or glass. Since the cavities on the surface of the cover layer are formed according to the invention with a defined scoop volume, the cavities can accordingly accommodate a desired volume of a pressure medium. This makes it possible to apply a desired quantity of a production material to a printing material.

In one embodiment of the invention, the device can be used to print a 3D structure. For this purpose, powder or fibers are preferably used as the pressure medium. According to the invention, cavities are formed on the printing form, in which the printing medium is received. Switching off the voltage at the actuators causes their deformations to recede and thus also the deformations (cavities) of the cover layer. The printing medium is then delivered to the printing material. The print medium is then dried and/or cured.

• Es gibt keine Beschränkungen der Druckmuster hinsichtlich deren Rapportlänge oder deren Druckdatenlänge.
• Es können digitale Druckmuster gedruckt werden, die eine geringere Druckdatenbreite als die Druckform aufweisen. In diesem Fall weist die Deckschicht nur an den Stellen der Druckform Kavitäten mit einem Schöpfvolumen ungleich Null auf, die für das Drucken des digitalen Druckmusters notwendig sind.
• Farbverläufe und Mischfarben können in der Qualität des Tiefdrucks abgebildet werden.
• Es können alle für das Aufbringen eines Druckmediums geeigneten Bedruckstoffe verwendet werden. Die Bedruckstoffe können glatte als auch raue Oberflächen aufweisen, auf die das Druckmedium aufgebracht wird.
• Während der Produktion können Veränderungen im Druckmuster vorgenommen werden, die sich unmittelbar in der Druckform umsetzten lassen.
• Die Anfertigung von unveränderlichen statischen Druckformen abgestimmt auf jedes Druckmuster, wie im herkömmlichen Tiefdruck genutzt, entfällt, ebenso deren Wechsel oder Einlagerung.
• Es können alle Druckmedien verwendet werden, die aus dem Tiefdruck bekannt sind und preisgünstiger sind als Druckmedien für den Digitaldruck.
• Es kann mit den gleichen Geschwindigkeiten wie im konventionellen Tiefdruck gedruckt werden, ohne dass Qualitätsverluste in der Druckauflösung auftreten.
• Qualitätsprobleme des Digitaldruck (Sprühnebel, Kondensatbildung, Satellitenausbildung, Einfluss von Luftverwirbelungen, Streifenbildung durch Druckkopfausfälle) treten nicht auf.
• Die vorliegende Erfindung ist einfach in bestehende analoge Druckanlagen implementierbar.

The present invention offers numerous advantages over the prior art, including:

• There are no restrictions on the print pattern in terms of repeat length or print data length.
• Digital print samples can be printed that have a smaller print data width than the print form. In this case, the top layer has cavities with a suction volume not equal to zero only at those points on the printing form that are necessary for printing the digital print pattern.
• Color gradients and mixed colors can be reproduced in the quality of gravure printing.
• All printing materials suitable for applying a printing medium can be used. The substrates can have smooth as well as rough surfaces to which the printing medium is applied.
• Changes in the print pattern can be made during production, which can be implemented directly in the printing form.
• The production of unchangeable static printing forms tailored to each print pattern, as used in conventional gravure printing, is no longer necessary, nor is their replacement or storage.
• All print media that are known from gravure printing and are cheaper than print media for digital printing can be used.
• It can be printed at the same speeds as in conventional gravure printing without any loss of quality in print resolution.
• Quality problems in digital printing (spray, condensation, formation of satellites, influence of air turbulence, streaking due to print head failure) do not occur.
• The present invention is easy to implement in existing analog printing systems.

Figur 1

(A) und (B) stellen Verfahren im Digitaldruck aus dem Stand der Technik dar;

Figur 2

(A) zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung, bei der Kavitäten in der Deckschicht ausgebildet werden; (B) zeigt eine weitere Ausführungsform der Vorrichtung mit Aktoren, die Ventile aufweisen;

Figur 3

(A) zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung, bei der das Schöpfvolumen der Kavitäten der Deckschicht durch einen Volumenstrom eines Druckgases gesteuert wird; (B) zeigt eine weitere Ausführungsform der Vorrichtung mit Aktoren, die Ventile aufweisen;

Figur 4

zeigt eine weitere Ausführungsform der erfindungsgemäßen Vorrichtung, bei der das Schöpfvolumen der Kavitäten der Deckschicht durch einen Volumenstrom eines Druckgases gesteuert wird;

Figur 5

zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung, bei der der Druckkörper eine Druckplatte ist;

Figur 6

zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit einem Hohlraum in der Deckschicht;

Figur 7

zeigt Ausführungsform der erfindungsgemäßen Vorrichtung mit einem Sleeve über der Deckschicht;

Figur 8

zeigt eine Deckschicht einer Druckform;

Figur 9

(A) und (C) zeigen verschiedene Formen von Kavitäten im Querschnitt durch die Deckschicht betrachtet und (B) in der Aufsicht auf die Deckschicht;

Figur 10

(A) bis (C) stellen drei verschiedene Druckformen dar;

Figur 11

zeigt eine Ausführungsform eines Druckvorganges;

Figur 12

zeigt eine Ausführungsform der Erfindung mit einer Vorrichtung zur Datenübertragung mit einem Kontakt;

Figur 13

zeigt eine weitere Ausführungsform der Erfindung mit einer Vorrichtung zur Datenübertragung mit zwei Sender-/Empfängervorrichtungen;

Figur 14

(A) und (B) stellen zwei Ausführungsformen der Erfindung mit Vorrichtungen zur Abgabe eines Druckmediums dar;

Figur 15

(A) stellt eine erste Ausführungsform der Erfindung mit einer Ausführungsform für die Vorrichtung zur Abgabe eines Druckmediums über Tintenleitungen dar; (B) stellt eine zweite Ausführungsform der Erfindung mit einer Vorrichtung zur Abgabe eines Druckmediums über Tintenleitungen dar;

Figur 16

(A) zeigt eine Ausführungsform der Erfindung zum indirekten Bedrucken, (B) zeigt eine Ausführungsform der Erfindung zum direkten Bedrucken und (C) zeigt eine Ausführungsform der Erfindung zum indirekten Bedrucken von strukturierten Bedruckstoffen;

Figur 17

zeigt eine Ausführungsform der Erfindung zum direkten Bedrucken.

The invention is explained in more detail below with reference to 17 figures and 14 exemplary embodiments.

figure 1

(A) and (B) represent prior art methods of digital printing;

figure 2

(A) shows an embodiment of the device according to the invention, in which cavities are formed in the cover layer; (B) shows another embodiment of the device with actuators having valves;

figure 3

(A) shows an embodiment of the device according to the invention, in which the suction volume of the cavities of the cover layer is controlled by a volume flow of a compressed gas; (B) shows another embodiment of the device with actuators having valves;

figure 4

shows a further embodiment of the device according to the invention, in which the suction volume of the cavities of the cover layer is controlled by a volume flow of a compressed gas;

figure 5

shows an embodiment of the device according to the invention, in which the pressure body is a pressure plate;

figure 6

shows an embodiment of the device according to the invention with a cavity in the cover layer;

figure 7

shows embodiment of the device according to the invention with a sleeve over the cover layer;

figure 8

shows a top layer of a printing form;

figure 9

(A) and (C) show different shapes of cavities viewed in cross-section through the cover layer and (B) in plan view of the cover layer;

figure 10

(A) to (C) represent three different printing forms;

figure 11

shows an embodiment of a printing process;

figure 12

shows an embodiment of the invention with a device for data transmission with a contact;

figure 13

shows a further embodiment of the invention with a device for data transmission with two transmitter/receiver devices;

figure 14

(A) and (B) illustrate two embodiments of the invention having means for dispensing a print medium;

figure 15

(A) shows a first embodiment of the invention with an embodiment for the device for discharging a print medium via ink lines; (B) illustrates a second embodiment of the invention having an apparatus for dispensing a print medium through ink ducts;

figure 16

(A) shows an embodiment of the invention for indirect printing, (B) shows an embodiment of the invention for direct printing, and (C) shows an embodiment of the invention for indirect printing on textured substrates;

figure 17

Figure 12 shows an embodiment of the invention for direct printing.

Figure 1 (A) shows a method for indirect digital printing, which is known from the prior art. In this case, a print medium 100 is applied to a roller 20 via a digital printer 10 . The roller then transfers the printing medium 100 to the printing material 30. Figure 1 (B) FIG. 1 shows a method for directly printing a printing material 30 with a printing medium 100 using a digital printer 10. Both methods have the disadvantages of the prior art described at the outset, which are known to the person skilled in the art for digital printing.

Figure 2 (A) FIG. 12 shows an embodiment of the device according to the invention, in which cavities 60 are formed in the cover layer 42. FIG. The device has a pressure roller 20 as the pressure body. The separating layer 110, which has a large number of perforations 111, is located on the printing roller. Piezo actuators 45 , 46 are arranged in the pressure roller 20 in such a way that the piezo actuators 45 , 46 adjoin the separating layer 110 . Above the separating layer 110 is the cover layer 42, which has webs 65 in the illustrated embodiment. A voltage is applied to the piezo actuator 46, as a result of which it undergoes mechanical deformation. A cavity 49 is then formed between the piezoelectric actuator 46 and the separating layer 110. The perforations 111 of the separating layer are filled with a medium filled with air, for example, which flows through the perforations 111 adjoining the cavity 49 into the cavity 49 . As a result, a negative pressure is generated, as a result of which the cover layer 42 above the cavity 49 is arched in the direction of the piezoelectric actuator 46 . As a result, the cavity 60 is formed. The greater the voltage applied to the piezoelectric actuator 46, the more it is mechanically deformed and the greater the resulting negative pressure, as a result of which the cover layer is arched to a greater extent. The volume of the cavity 60 formed can thus be controlled by the strength of the voltage applied to the piezoelectric actuator 46 . No voltage is applied to the piezoelectric actuator 45, as a result of which this piezoelectric actuator is not mechanically deformed. Therefore, no cavity is formed in the cover layer 42 at this position. The voltage across the piezo actuators 45, 46 is controlled by the computer 50.

Figure 2 (B) FIG. 14 illustrates another embodiment of the present invention in which cavities 60 are formed in the cover layer 42. FIG. The structure is similar to the structure of the device Figure 2 (A) . In this embodiment, however, the actuators have valves 150 , 151 and cavities 140 are located in the cover layer 42 and are arranged on the separating layer 110 . The cavities 140 are connected to the valves 150, 151 via perforations 111 in the separating layer 110. FIG.

If a valve 150 is opened by the controller, a cavity 49 is created according to the invention between valve 150 and separating layer 110, so a medium that is in cavities 140 in cover layer 42 can flow through adjacent perforations 111 into cavity 49 between valve 150 and release layer 110 penetrate. This process reduces the pressure in the cavities 140 of the cover layer 42 and creates a negative pressure. Due to the change in pressure, the cover layer 42 is arched over the cavities 140 in the cover layer 42 in the direction of the valve 150, with the result that a cavity 60 is formed on the surface of the cover layer 42. In this embodiment, the cover layer 42 can have one or more cavities 140 . If the valve 151 is closed, no cavity 49 is formed between the valve 151 and the separating layer 110, there is no negative pressure and, accordingly, no cavity 60 is formed on the surface of the cover layer 42.

Figure 3 (A) represents a further embodiment of the device according to the invention. In this embodiment, the cover layer 42 has a multiplicity of cavities 60, 61, with each cavity 60, 61 having at least one channel 120, 121. The channels 120, 121 connect the cavities 60, 61 to the perforations 111, 112 of the separating layer 110. Below the separating layer 110, the piezoelectric actuators 45, 46 are arranged, which adjoin the separating layer 110. Within the pressure body, which in this embodiment has a pressure roller 20 compressed gas lines 130, 131 run. The compressed gas lines 130, 131 end at the piezo actuators 45, 46. A voltage is applied to the piezo actuator 46, so that it is mechanically deformed and the cavity 49 between the piezo actuator 46 and the separating layer 110 is formed. Channel 131 terminates at cavity 49 and directs pressurized gas into it. The compressed gas escapes through the perforation 112 and the channel 121 into the cavity 61. The scoop volume is reduced by the compressed gas escaping into the cavity 61.

No voltage is applied to the piezoelectric actuator 45, so that it does not experience any mechanical deformation. The compressed gas in the compressed gas line 130 is blocked by the piezoelectric actuator 45 and cannot escape into the perforation 111 of the separating layer 110 . Thus, no compressed gas escapes into the cavity 60 and the suction volume of the cavity 60 thus corresponds to the volume of the cavity 60. The voltage at the piezoelectric actuators 45, 46 is controlled by the computer 50.

Figure 3 (B) represents a further embodiment of the device according to the invention. In this embodiment, the cover layer 42 has a multiplicity of cavities 60, 61, with each cavity 60, 61 having at least one channel 120, 121. The channels 120, 121 connect the cavities 60, 61 with the perforations 111, 112 of the separating layer 110. Below the separating layer 110, the valves 150, 151 are arranged, which adjoin the separating layer 110. The pressure hull 20 is partially filled with a gas which has excess pressure. By opening the valve 150, gas can flow from the interior of the pressure body through the perforations 111 of the separating layer 110 into the channel 121 and thus into the cavity 61. A pressure medium that is applied is displaced by the volume flow of the escaping gas, and the scoop volume of the cavity 61 is thus reduced.

If the valve 151 is closed, no gas can escape from the interior of the pressure body into the cavity 60 adjacent to the valve, and this therefore has the maximum scoop volume.

figure 4 FIG. 12 illustrates a further embodiment of the device in which the cover layer 110 has a plurality of cavities 60, each cavity having at least one channel 120. FIG. The channel 120 connects the cavity 60 to the cavity 49 via the perforation 112 in the separating layer 110. The cavity 49 is formed by the mechanical deformation of the piezoelectric actuator 46. FIG. Numerous compressed gas lines 130, 131, 132, which end at the piezoelectric actuator 46, run in the pressure body. The compressed gas lines 130, 131, 132 are arranged on the piezoelectric actuator 46 in such a way that more and more compressed gas lines 130, 131, 132 release compressed gas into the cavity 49 that is formed as the deformation of the piezoelectric actuator increases be able. When the voltage applied is low and the mechanical deformation of the piezoelectric actuator 46 is therefore only small, initially only the compressed gas line 130 opens into the resulting cavity 49. If the applied voltage is increased, the piezoelectric actuator also deforms more and the cavity 49 becomes larger. As a result, the compressed gas line 130 and 132 now border on the cavity 49 and direct compressed gas into it. If the voltage applied to the piezoelectric actuator 46 is increased even further, the cavity 49 is finally so large that all three compressed gas lines 130, 131, 132 end in the cavity and introduce compressed gas into it. The more compressed gas lines 130, 131, 312 introduce compressed gas into the cavity, the greater the volume flow of the compressed gas that flows through the at least one channel into the cavity 60. The greater the volume flow of the compressed gas into the cavity 60, the smaller the scoop volume of the cavity 60, since a pressure medium is displaced by the outflowing compressed gas during application.

figure 5 represents a further embodiment of the invention. In this embodiment, the pressure body is a pressure plate 26. The device functions in the same way as in figure 2 device shown.

figure 6 12 illustrates another embodiment of the present invention in which the cover layer 42 has a plurality of cavities 60. FIG. Furthermore, the cover layer 42 has a cavity 141 which adjoins the separating layer 110 and is connected to the valve 150, 151 via the perforations 111. The cavity 141 is arranged below a cavity 60 and can accommodate a gaseous or liquid medium. If there is no medium in the cavity 141, it is compressed by the overlying cover layer 42 in such a way that a cavity 60 is present on the cover layer 42 at this position.

In this embodiment, the actuator 200, 201 has at least one valve and a reservoir for a liquid or gaseous medium. Furthermore, the actuator 200, 201 has a suitable device which can press the medium through the at least one valve into the adjacent perforations 111 of the separating layer 110 or which sucks the medium out of the cavity 414 and the adjacent perforations 111 back into the reservoir. For the sake of clarity, the individual components of the actuator 200, 201 are not shown.

The device preferably has a controller that can be controlled by an applied voltage. The device is preferably controlled together with the at least one valve. Such a device can, for example, be in a cylinder extending piston, with part of the cylinder representing the reservoir for the gaseous or liquid medium.

Medium can be pressed into the cavity 141 of the cover layer 42 by opening the at least one valve of the actuator 151 . As a result, the cover layer 42 above the cavity 141 is deformed in such a way that the suction volume of the cavity located above the cavity is reduced or becomes zero. At the maximum filling level of the cavity, as shown in the figure, the suction volume of the cavity above is zero.

Conversely, with appropriate control, the medium can be sucked out of the cavity 141 into the reservoir. In this case, as already described, the cavity 141 is compressed by the overlying cover layer 42 and the cavity 60 on the surface of the cover layer 42 assumes the greatest possible volume.

figure 7 FIG. 14 illustrates an embodiment in which the device includes a sleeve 160 that is disposed on top of cover sheet 42 and completely covers it. According to the invention, the sleeve 160 thus also covers the cavities 60, 6 that are present in the cover layer 42.

The actuator has a valve 150 , 151 which is adjacent to the separating layer 110 . In the closed state of the valve 150, 151, the adjacent cavity 60, 61, each adjacent channel 120, 121 and the adjacent perforations 111 form a closed space. A gaseous or a liquid medium can be located in this closed space. According to the invention, the medium in the space has a suitable pressure in order to shape the sleeve 160 in such a way that the underlying cavity 60, 61 is covered in such a way that no pressure medium can be accommodated at this position.

Opening valve 151 creates a cavity 49 between valve 151 and separating layer 110 . According to the invention, at least one perforation 112 of the separating layer 110 adjoins the cavity 49 in such a way that the exchange of a gaseous or liquid medium between the cavity 49 and the perforation 112 is made possible. According to the invention, a medium that is located in the adjacent perforations 112 of the separating layer 110, the adjacent channel 121 and the adjacent cavity 61 can therefore penetrate into the cavity 49. The pressure in the cavity 61 is reduced by this process; in a preferred embodiment, a negative pressure is generated in the cavity 61 49 by this process. Due to the change in pressure, this becomes above the cavity 61 lying sleeve 160 is deformed towards the valve 151 and the scoop volume of the cavity 61 is increased.

If the valve 150 is closed, the entire medium is pressed into the perforations 111 and the channel 120 and the cavity 60 adjacent to the valve 150 . The sleeve 160 thus covers the cavity 60 in such a way that no print medium 100 can be accommodated by the cavity 60 .

figure 8 shows the cover layer 42 in a plan view. A large number of cavities 60 are shown, which in this view have a circular outline.

Figure 9 (A) shows three different shapes of cavities 60 formed in a cover layer 42. FIG. The cover layer 42 is shown in cross section. As shown, cavities 60 of various shapes can be formed or formed in the cap layer with the present invention. It is therefore possible to adapt the shape of the cavities to the desired application. The present invention thus offers great flexibility when printing on substrates 30. Figure 9 (B) Figure 12 illustrates the shape of cavities 60 when top layer 42 is viewed from above. All cavities 60 have a circular shape in this view. Figure 9(C) shows other shapes of cavities listed in the table below. The cover layer 42 is shown in cross-section. figure shape of the cavity a pointed pyramid b truncated pyramid c Truncated pyramid with steep flanks i.e pointed cap e normal calotte f U-shape with steep sides and a wide base

Figure 10 (A) to (C) represent three different printing forms, each with a roller 20 serves as a pressure body. The rollers 20 have different diameters. In conventional gravure printing, the roller circumference determines the maximum print data length or the repeat that can be printed with, since the cells are fixed to the print body. With the present invention, however, it is possible to change the scoop volume of the cavities 60 and thus also the arrangement of the printing and non-printing areas of the cover layer during a printing process. Therefor the printing form according to the invention has a sensor which is suitable for exactly determining a position of the circumference of the roller. With the help of the sensor, it is then possible to determine exactly at which point on the circumference of the roller it is currently printing. That is, the scoop volume of the cavities 60 can be changed after they have been printed.

The present invention therefore makes it possible to print digital print patterns on printing materials that have a longer print data length than the circumference of the roller. Compared to conventional gravure printing, this offers the advantage that the circumference of a printing roller can be selected independently of the length of the print data or the length of a repeat of a print pattern. This means that it is no longer necessary to provide rollers with different circumferences in production in order to print print samples with different print data lengths. Conversely, the print data length that can be printed is no longer dependent on the existing rollers. Any length of print data can be printed with one roller with the present invention. This offers an enormous economic advantage and an enormously increased flexibility compared to conventional gravure printing devices and processes.

The printing form Figure 10 (C) can map the same print data length in seven circulations as the print form in Figure 10 (B) in two rounds. Both printing forms form the same print data length as the printing form in Figure 10 (A) . After the end of the printing process, in all three cases there are printing materials that have the same print pattern with the same print data length.

figure 11 represents an example for the execution of a printing process with the present invention. The four printing forms have the rollers 20, 21, 22, 23 as pressure bodies. A different print medium is assigned to each roller. Digital separation data is created from a digital print pattern by a control device 50 in the form of a computer. The digital separation data are then transmitted to the rollers 20, 21, 22, 23 and the scoop volume of the cavities on the cover layers of the rollers 20, 21, 22, 23 is controlled accordingly. The calculation of separation data is based on methods known to those skilled in the art.

figure 12 shows an embodiment of the invention with a device for data transmission. All actuators are networked 70 for data transmission. Some of the actuators are each connected via an intermediate network 71 to a central network with a contact 72 . The contact can be a slip ring transmitter, for example. About a connection to a control device, for example in the form of a computer 50, can be established via the contact. This arrangement makes it possible to exchange data between the control device and the actuators and thus to control the scoop volumes of the cavities 60 . Networking takes place via electronic connections such as cables, circuit boards and/or conductor foils. A roller 20 is shown in two views as the pressure body.

figure 13 represents another embodiment of the invention with a device for data transmission. Exactly as in FIG figure 10 the actuators are networked 70, with an intermediate network 71 leading to a central network with a transmitter/receiver device 73 which is suitable for transmitting data without contact. A control device, for example in the form of a computer 50, also has a transmitter/receiver device 74 which is suitable for transmitting data in a contactless manner. This arrangement makes it possible to exchange data between the control device and the actuators and thus to control the scoop volumes of the cavities 60 . A roller 20 is shown in two views as the pressure body.

Figure 14 (A) shows an embodiment of the invention with a device for dispensing a print medium 100. The print medium 100 is picked up from a container 91 by the roller 20 of the printing form dipping into the container 91 and the cavities 60 on the cover layer 42 are completely flooded with print medium. The squeegee 25 then removes the excess printing medium 100, so that there is only printing medium 100 in the cavities 60, but the cover layer between the cavities 60 is free of the printing medium. The print medium 100 is transferred to the rubber roller 80 and from there to the printing material 30. The control of the printing process is symbolized by a control device in the form of a computer 50.

Figure 14 (B) shows a further embodiment of the invention with a device for dispensing a print medium 100. Here the print medium 100 is placed on the printing form from above, the printing form comprising a roller 20. FIG. The excess printing medium 100 is removed by the squeegee 25. The print medium 100 is then transferred to the rubber roller 80 and from there to the printing material 30. The control of the printing process is symbolized by a control device in the form of a computer 50.

Figure 15 (A) Fig. 13 shows another embodiment of the invention with an apparatus for dispensing a print medium 100, the ink ducts 90 within the print hull includes. The ink lines 90 advantageously run through the printing body and end in the cover layer 42 of the printing form. The ink ducts 90 are positioned so that each cavity 60 present on the cover layer 42 can be filled with print medium 100. In this embodiment, the cavities 60 are filled from the inside of the pressure hull. Ink lines 90 are connected to respective reservoirs containing print media 100 . The cavities 60 can be filled in a targeted manner using suitable pumping and control devices. The containers with the print media 100 and the pumping devices are not shown for the sake of clarity. A computer 50 is shown symbolically as the control device. The print medium is transferred from the printing form to a rubber roller 80 and from there to the printing material 30.

Figure 15 (B) shows the same structure of a printing form with ink lines 90. In this embodiment, however, the printing material 30 is printed directly from the printing form with the printing medium 100.

Figure 16 (A) to (C) shows different transfer paths of the print medium 100 to a printing material 30 in the printing process using the method according to the invention. Figure 16 (A) shows an indirect transfer of the printing medium 100 from the printing form via a rubber roller 80 to the printing material 30.

Figure 16 (B) represents a direct printing method using the method according to the invention. The printing medium 100 is transferred directly to the printing material 30 by the printing form.

The method according to the invention is also suitable for printing structured printing materials. Figure 16 (C) shows a printing method with a printing forme that has a roller 20 as a pressure body. A print medium 100 is applied to the printing form, and the print medium 100 is applied to a flexible transmission element 83 . The flexible transfer element 83 is guided over a deflection roller 81 and then the print pattern is transferred to the printing material 30 . For this purpose, the flexible transfer element 83 is pressed against the printing material 100 with a movable counter-pressure roller 82 . The movable counter-pressure roller 82 can adapt to the structuring of the printing material 30 in such a way that during the transfer of the printing medium 100 to the printing material 30 there is a sufficiently large contact pressure at all times. The contact pressure is sufficiently high if error-free transfer of the print medium 100 is ensured. The movable counter-pressure roller 82 also has an elastic coating such that the flexible transmission element 83 at least partially in structures on the Surface of the printing material 30 is pressed in, so that error-free transmission of the printing medium 100 is ensured.

figure 17 shows the printing of a printing material 30 with a device according to the invention. The device includes a pressure plate 26 as a pressure body. An impression roller 95 presses the printing material 30 onto the device according to the invention, so that a transfer of the printing medium 100 to the printing material 30 can take place.

Exemplary embodiment 1 - wood -based panel

The digital separation data were transferred from a digital print pattern, which represents a print decor, to four printing forms, with each printing form receiving a separate printing color. Each printing form had a roller 20, 21, 22, 23 as the printing body. The printing forms had a large number of cavities 60 , 61 on the cover layer 42 . The scoop volume of the cavities 60, 61 was controlled via the volume flow of a compressed gas flowing into the cavities 60, 61 according to the present invention in such a way that the scoop volume of the cavities 60, 61 was controlled according to the digital separation data. Air was used as the compressed gas. The cavities 60, 61 of the rollers 20, 21, 22, 23 were each filled with paint via a container and the top layer 42 was then cleaned with a squeegee 25. The voltage at all actuators was then controlled in such a way that compressed gas could no longer flow into the cavities 60, 61. The colors were printed one after the other directly onto a pre-primed wood-based panel.

Exemplary embodiment 2 - wood -based panel

The digital separation data were transferred from a digital print pattern, which represents a print decor, to four printing forms, with each printing form receiving a separate printing color. Each printing form had a roller 20, 21, 22, 23 as the printing body. The cavities 60 were formed on the cover layer 42 of the rollers 20, 21, 22, 23 in accordance with the digital separation data. The cavities 60 of the rollers 20, 21, 22, 23 were each filled with paint via a container and the top layer 42 was then cleaned with a squeegee 25. The colors were printed one after the other directly onto a pre-primed wood-based panel.

Exemplary embodiment 3 - wood -based panel

The digital separation data were transferred from a digital print pattern, which represents a print decor, to four printing forms, with each printing form receiving a separate printing color. Each printing form had a roller 20, 21, 22, 23 as the printing body. The printing forms had a large number of cavities 60 , 61 on the cover layer 42 . The The scoop volume of the cavities 60, 61 was controlled via the volume flow of a compressed gas flowing into the cavities 60, 61 according to the present invention in such a way that the scoop volume of the cavities 60, 61 was controlled according to the digital separation data. Air was used as the compressed gas. The cavities 60, 61 of the rollers 20, 21, 22, 23 were each filled with paint via a container and the top layer 42 was then cleaned with a squeegee 25. The voltage at all actuators was then controlled in such a way that compressed gas could no longer flow into the cavities 60, 61. The color was transferred from the printing form to a rubber roller 80 and printed by it onto a preprimed wood-based panel. All the colors were applied one after the other in this way.

Exemplary embodiment 4 - wood -based panel

The digital separation data were transferred from a digital print pattern, which represents a print decor, to four printing forms, with each printing form receiving a separate printing color. Each printing form had a roller 20, 21, 22, 23 as the printing body. The cavities 60 were formed on the cover layer 42 of the rollers 20, 21, 22, 23 in accordance with the digital separation data. The cavities 60 of the rollers 20, 21, 22, 23 were each filled with paint via a container and the top layer 42 was then cleaned with a squeegee 25. The color was transferred from the printing form to a rubber roller 80 and printed by it onto a preprimed wood-based panel. All the colors were applied one after the other in this way.

Exemplary embodiment 5 - wood -based panel

The digital separation data were transferred from a digital print pattern, which represents a print decor, to four printing forms, with each printing form receiving a separate printing color. Each printing form had a plate 26 as the printing body. The cavities 60 were formed in accordance with the separation file and filled with ink using an applicator roller, and the surface of the cover layer 42 was then cleaned with a squeegee 25 . The print pattern was printed directly onto a pre-primed wood-based panel.

Example 6 - Paper

A primer was applied to a print base paper with a weight of 70 g/m ² and then the print base paper was printed with a digital print pattern in the form of a decoration according to exemplary embodiment 1 and then further processed as follows:
The decorated paper layers were impregnated with aqueous melamine resin. After drying, the paper layers were cut and stacked to form a laminate for pressing. Various layers were stacked up to produce a laminate, as described below. A resin-impregnated paper layer was first applied as a counteract to the underside of a carrier board, which in this exemplary embodiment was a chipboard. The impregnated, decorated paper layer was applied to the upper side of the carrier board and then a so-called overlay. A resin-impregnated transparent paper layer equipped with hard material particles was used as an overlay. The stack was moved into a short-cycle press and pressed to form a laminate under the action of heat and pressure. A structured press plate was used on the top side in the short-cycle press, so that a structure was created on the surface of the laminate. The structure produced is at least partially synchronous with the decor of the paper layer.

Example 7 - structured surface

The digital separation data were transferred from a digital print pattern, which represents a print decor, to four printing forms, with each printing form receiving a separate printing color. Each printing form had a roller 20, 21, 22, 23 as the printing body. The scoop volume of the cavities 60, 61 were controlled on the cover layer 42 of the rollers 20, 21, 22, 23 according to the digital separation data. The cavities 60, 61 of the rollers 20, 21, 22, 23 were each filled with paint via a container and the top layer 42 was then cleaned with a squeegee 25. The ink was transferred from the printing form to a flexible transfer element 83 . The flexible transmission element 83 was deflected via a deflection roller 81 and then the flexible transmission element 83 was pressed against a structured, pre-primed wood-based material board by a movable counter-pressure roller 82 . This printing process was carried out sequentially for all colors. The pre-primed wood-based panel was thereby provided with the printed decor in such a way that the printed decor is essentially synchronous with the structure of the wood-based panel.

Example 8 - Finishing

After applying a primer, wood-based panels (HDF) were printed according to exemplary embodiments 1 to 4 and further processed as follows:
The printed HDF boards were separated in front of the production line and transported through the downstream production plant at a speed of 40 m/min.

In a first roller application unit, about 70 g melamine resin fl. (solids content: 55% by weight) containing the usual auxiliaries (hardener, wetting agent, etc.) are applied to the board surface. A melamine resin is also applied to the underside of the board using the first roller application unit (amount applied: 60 g resin fl./m ² , solids content: approx. 55% by weight).

Thereafter, 14 g of corundum/m ² (F 200) are sprinkled onto the surface using a scattering apparatus. A melamine resin layer (solids content: 55% by weight) is then applied in an amount of 25 g/m ² . This also contains the usual excipients. A melamine resin is also applied to the underside of the board using a roller application unit (amount applied: 50 g resin fl./m ² , solids content: approx. 55% by weight). The plate is dried in a circulating air dryer.

A melamine resin, which also contains glass beads, is then applied to the surface of the board. These have a diameter of 60 - 80 µm. The amount of resin applied is around 20 g melamine resin fl./m ² (solids content: 61.5% by weight). In addition to the hardener and the wetting agent, the formulation also contains a release agent. The amount of glass beads applied is approx. 3 g/m ² . A melamine resin is also applied to the underside of the board using a roller application unit (amount applied: 40 g resin fl./m ² , solids content: approx. 55% by weight). The board is again dried in a circulating air dryer and then coated again with a melamine resin containing glass beads. Another component is cellulose (Vivapur 302). Approx. 20 g melamine resin fl./m ² (solids content: 61.6% by weight) are again applied. Approx. 3 g glass beads and 0.25 g cellulose/m ² are applied again. In addition to the hardener and the wetting agent, the formulations also contain a release agent. A melamine resin is also applied to the underside of the board using a roller application unit (amount applied: 30 g resin fl./m ² , solids content: approx. 55% by weight). The resin is again dried in a circulating air dryer and then the board is pressed in a short-cycle press at 200° C. and a pressure of 400 N/cm ² . The pressing time was 10 seconds. A pressed sheet metal with a wooden structure was used as a structuring agent.

The amount of resin varies per roll application in the range from 5 g/m ² to about 100 g/m ² ; the solids content of the resin can also vary in the range from 50% by weight to about 80% by weight. The amount of corundum varies between 2 g/m ² and 30 g/m ² . The additives glass and corundum also vary in their respective amounts.

Exemplary embodiment 9 - functional material

• Vereinzelung der HDF-Platten von einem Lagerstapel,
• Anschliff der HDF-Platten auf der Oberseite,
• Auftragen einer transparenten Grundierung bestehend aus Melaminharz,
• Trocknung der Grundierung,
• Auftrag einer mit Titandioxid pigmentierten Grundierung mit Zwischentrocknung (bis zu 7x),
• direktes Aufbringen einer dünnen Schicht einer Tinte mit Kohlenstoffnanopartikeln mittels einer der erfindungsgemäßen Vorrichtung zur Ausbildung einer Fußbodenheizung als Funktionsschicht (Auftragsmenge: 3 - 50 g Pigment/m²), flächig oder streifenförmig,
• Trocknung der Funktionsschicht,
• Digitaldruck eines Fliesendekors,
• Trocknung,
• Auftrag eines Transportschutzes bestehend aus Melaminharz,
• Trocknung

In production, a batch of HDF boards is processed, which is to be provided with a functional layer designed as underfloor heating. The procedure is as follows:

• Separation of the HDF panels from a storage stack,
• Polishing of the HDF panels on the upper side,
• Application of a transparent primer consisting of melamine resin,
• drying of the primer,
• Application of a primer pigmented with titanium dioxide with intermediate drying (up to 7x),
• Direct application of a thin layer of an ink with carbon nanoparticles using one of the devices according to the invention for the formation of underfloor heating as a functional layer (amount applied: 3-50 g pigment/m ² ), areally or in strips,
• drying of the functional layer,
• digital printing of a tile decor,
• drying,
• Application of a transport protection consisting of melamine resin,
• drying

Embodiment 10 - Print Data Length

The digital separation data were transferred from a digital print pattern, which represents a print decor, to four printing forms, with each printing form receiving a separate printing color. Each printing form had a roller 20, 21, 22, 23 as the printing body. The scoop volume of the cavities 60, 61 on the cover layer 42 of the rollers 20, 21, 22, 23 was controlled according to the digital separation data. The cavities 60, 61 of the rollers 20, 21, 22, 23 were each filled with paint via a container 81 and the top layer 42 was then cleaned with a squeegee 25. The colors were printed one after the other directly onto a pre-primed wood-based panel.

The circumference of the rollers 20, 21, 22, 23 of the printing forms was 70 cm, but the print data length of the print pattern was 140 cm. During the printing process, the scoop volume of the cavities 60, 61 of each roller 20, 21, 22, 23, which had already printed, was changed immediately after the printing process. The scoop volume was changed in such a way that the entire print pattern could be printed with two revolutions of the rollers 20, 21, 22, 23.

Embodiment 11 - Computer Chips/PCBs

Base bodies made of electrically insulating material, such as fiber-reinforced plastic or laminated paper, are used as the substrate. Ink or powder with electrically conductive particles is used as the printing medium. By means of the device according to the invention, a functional layer is applied to the printing material as an electrically conductive form, for which purpose the base bodies are laid out in rows. The application quantity of the print medium is in the range of 3-50g pigment per m ² . The functional layer is then dried and/or cured.

Working example 12 - 3D printing

By means of the device according to the invention, a powder or fibers are taken up as the pressure medium. By switching off the applied voltage, the cavities form back and release the powder or fibers onto the printing material. The printed layer is then dried and/or cured.

Example 13 - printed structure

A UV varnish is picked up by means of the device according to the invention and applied to a printing material. The application of the UV coating is carried out on the printing material at positions where a structural formation is desired, for example in areas where a decoration is shown on the printing material, which, among other things, represents wood pores. The structure printed by the device according to the invention is essentially congruent with the pore structure.

Example 14 - order production material

A production material such as corundum or glass is accommodated as a pressure medium by the device according to the invention. A precisely defined amount of the pressure medium is taken up, which is determined by the scoop volume of the cavities. This makes it possible to dose the application quantity of a print medium and to carry out a fully automatic adjustment to recipes for the application quantity of production materials.

Reference List

10

digital printer

20, 21, 22, 23

roller

25

squeegee

26

printing plate

30

substrate

42

top layer

45, 46

piezo actuator

48, 49

cavity

50

computer

60, 61

cavity

65

web

70

networking of the cavities

71

interconnection

72

Central networking with contact

73

Central networking with transmitter/receiver device

74

transmitter/receiver device

80

rubber roller

81

deflection roller

82

backing roller

83

flexible transmission element

90

ink line

91

container

95

impressioner

100

print media

110

release layer

111, 112

perforation

120, 121

channel

130, 131, 132

compressed gas line

140, 141

cavity in top layer

150, 151

Valve

160

Sleeve

200, 201

actuator

Claims (15)

Device for generating a print on a printing material (30) comprising • at least one printing form; • at least one device for dispensing a print medium (100); • at least one device for data transmission; • at least one control device; characterized in that
the printing form has a printing body, a multiplicity of actuators, a separating layer (110) with a multiplicity of perforations (111, 112) and a cover layer (42); at least one actuator is connected to the cover layer (42) by at least one perforation (111, 112); and
each actuator is electrically addressable independently of the other actuators;
wherein the cover layer (42) is set up to form a multiplicity of cavities (60, 61) for accommodating a print medium (100) or wherein the cover layer (42) has a multiplicity of cavities (60, 61) for accommodating a print medium (100) having; and
each cavity (60, 61) having a scoop volume for the print medium (100) which is controllable. Device according to Claim 1, characterized in that the cover layer (42) is designed to form a large number of cavities (60, 61) for receiving a print medium (100), each actuator being able to form at least one cavity (60, 61). Device according to one of the preceding claims, characterized in that the device is set up to form cavities (60, 61) with variable shape and/or depth in the cover layer (42). Device according to Claim 1, characterized in that the cover layer (42) has a multiplicity of cavities (60, 61), each cavity (60, 61) having at least one channel (120, 121);
at least one perforation (111, 112) of the separating layer (110) adjoins at least one channel (120, 121) of a cavity (60, 61) in the cover layer (42); and at least one actuator is adjacent to the at least one perforation of the separating layer. Device according to claim 4, characterized in that the pressure body comprises a compressed gas; and
the device is set up so that • a voltage is applied to at least one actuator; • Compressed gas escapes from the pressure body into the at least one cavity (60, 61) connected to the at least one actuator; • a printing medium (100) is applied to the printing form; and • the scoop volume of the at least one cavity (60, 61) is controlled by the volume flow of the outflowing compressed gas. Device according to claim 5, characterized in that the compressed gas is air. Device according to claim 4, characterized in that the device further comprises a sleeve (160) which is arranged on the cover layer (42). Device according to Claim 1, characterized in that the cover layer (42) has a multiplicity of cavities (60, 61), the cover layer (42) further having at least one cavity which is connected to at least one actuator through the perforations of the separating layer; and
wherein the at least one actuator is arranged in such a way that the actuator controls the scoop volume of the at least one cavity (60, 61). Device according to one of the preceding claims, characterized in that the actuator has at least one component from the group containing piezo actuators, valves, a combination of valves and valves with nozzles. Device according to one of the preceding claims, characterized in that the printing medium (100) has at least one pigment-containing liquid or at least one functional material. Method for producing a multiplicity of cavities (60) on a printing form by means of a device according to one of claims 1 to 3, wherein each actuator can be electrically addressed independently of the other actuators via a controller and thereby acts on the cover layer (42),
characterized in that a voltage is applied to each actuator at whose position a cavity (60) is to be formed on the surface of the printing form; the cover layer (42) is deformed by the applied voltage and a cavity (60) is thereby formed on the surface of the printing form at this position. Method according to Claim 11, characterized in that the depth and thus the scoop volume of the cavity (60) is controlled by the strength of the voltage applied to the associated actuator. Method for controlling the scoop volume of cavities (60, 61) on a printing form by means of a device according to one of Claims 4 to 8, each actuator being electrically addressable independently of the other actuators via a controller , characterized in that a voltage is applied to at least one actuator; Compressed gas escapes from the pressure body through the channel (120, 121) into the at least one cavity (60, 61) connected to the at least one actuator, or a medium is introduced into a cavity in the cover layer, or the sleeve (160) is deformed by pressure ; a printing medium (100) is applied to the printing form; wherein the scoop volume of the at least one cavity (60, 61) is controlled by the volume flow of the outflowing compressed gas or by the volume of the medium flowing into the cavity or by the magnitude of the pressure with which the sleeve (160) is deformed. Method for printing a printing material (30) with a device according to one of claims 1 to 10 with a digital print pattern, characterized in that
the actuators are controlled electrically, so that the cavities (60, 61) can accommodate a suction volume of a printing medium (100) that is suitable for imaging the digital print pattern on a printing material (30) or that cavities (60) with a suction volume are on the printing form are formed, which are suitable for imaging the digital print pattern on a printing material (30);
a print medium (100) is received from the printing form by a device for dispensing a print medium (100); and
the digital print pattern is printed directly or indirectly onto the printing material (30) using the device. Method according to Claim 14, characterized in that the printing material (30) is selected from a group containing paper, glass, metal, foils, wood-based materials, in particular MDF or HDF boards, WPC boards, veneers, lacquer layers, Plastic panels, fiber-reinforced plastic, laminated paper and inorganic carrier panels.

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