PRINTING MACHINE WITH AT LEAST ONE PRINTING HEAD

Description

[0001] The invention relates to a printing machine with at least one print head according to the preamble of claim 1.

[0002] US 2017 / 0066232 A1 discloses a printing system for printing on curved surfaces of a plurality of objects, the printing system comprising: a support platform for supporting and moving the plurality of objects along a closed path, which are independently controlled with respect to their speed and position;a plurality of grippers mounted in spaced relationship along a length of the support platform, each of the plurality of grippers configured to hold and rotate a respective object at a predetermined working distance between the curved surface of the object and respective print head units disposed along a zone of the closed path, each of the plurality of grippers comprising a circular array of spaced-apart elongate members substantially parallel to a central axis of the gripper, and a lever mechanism configured to simultaneously move the elongate members toward and away from the central axis of the gripper, thereby varying the cross-sectional dimensions of the grippers to accommodate objects of different dimensions;and a control unit configured and operable to adjust the cross-sectional dimensions of the plurality of grippers to fit the plurality of objects, rotate the objects, and move the support platform along the closed path to print the plurality of objects simultaneously by the print head units;

[0003] US 2021 / 0276342 A1 discloses a print beam structure for a printing device for use in printing on an outer surface of an object, the object comprising at least one cylindrical portion, the print beam structure comprising: a body defining a print zone for receiving the object to be printed, the print zone having a central axis;and a plurality of radially spaced mounting formations provided adjacent to the print zone for mounting a plurality of print heads, the print heads being operatively arranged within the print zone to form an arc within the print zone for applying liquid from a liquid source to the object along a printing axis that is at least transverse to the central axis of the print zone, the print beam structure comprising a plurality of print banks, each print bank comprising mounting formations for one or more print heads, and each print bank extending along an axis that is oriented obliquely to the central axis, or the arc defined by the print heads extending along an axis that is oriented obliquely to the central axis;

[0004] US 2017 / 0203563 A1 discloses a liquid dispensing device comprising: a dispensing unit that dispenses liquid from nozzles to a medium; a rotation mechanism that relatively rotates the medium and the ejection unit about a rotation axis direction that crosses a ejection direction of the liquid; and a control unit that controls an ejection frequency of the liquid according to a relative moving distance between the medium and the ejection unit per unit time.

[0005] EP 3 909 780 A1 discloses a printing device comprising: n print heads arranged along a first direction, each print head being in fluid communication with at least two different inks; a print medium arranged opposite the print head, the print medium comprising s print areas divided along the first direction such that each print area is configured for printing by a print head, the print medium being configured to rotate about a rotation axis; a motion controller controlling the movement of the print heads and the movement of the print medium; and a print driver controlling the printing of the print heads, where s and n are positive integers greater than 1.

[0006] US 2016 / 0221361 A1 discloses a device for printing rotationally asymmetric containers, comprising: at least one print head; and a turntable configured to rotate at least one receptacle, mounted on the turntable, for a rotationally asymmetric container to be printed about a first axis of rotation, wherein the receptacle is arranged eccentrically to the first axis of rotation of the turntable and receives the container therein in such a way that an outermost portion of a surface to be printed of the container received in the receptacle is guided on a first circular path about the first axis of rotation.

[0007] WO 2015 / 186592 A1 discloses a transport unit that places and transports a recording medium on a conveying surface that has a curvature in a conveying direction of the recording medium. A nozzle surface, on which a nozzle opening for ejecting ink is arranged, is provided opposite the conveying surface. A recording head has a mounting element to which the recording head is mounted, with a plurality of mounting elements being provided at different positions in the conveying direction.

[0008] US 2017 / 0253024 A1 discloses an apparatus and method for printing an image on a non-cylindrical, circularly symmetrical surface of an object, wherein the printing is performed using a print head having inkjet nozzles with tips in a nozzle plane by rotating the object about the longitudinal axis of the surface, while a print engine controller drives the print head in space and controls the operation of the nozzle tips within a predetermined printing gap along the surface to print the image.

[0009] JP 2009184121 A discloses a three-dimensional printer that performs predetermined printing by ejecting ink from a print head onto a surface of an object to be printed. This printer includes a holding chuck that holds the object to be printed; first to third support members that support the holding chuck so as to be movable in space; a print head carriage that supports a front end that holds the print head so as to be linearly movable relative to the object to be printed held by the holding chuck; and a right-left oscillating drive device. The oscillating drive device rotates and moves the print head in a right-left direction, centering on an up-and-down rotation axis to perform the desired printing while ejecting ink from the print head.

[0010] US 2013 / 0215196 A1 and US 2005 / 0243112 A1 each disclose a printing machine having a plurality of print heads, each printing a surface of an article using an inkjet printing process, wherein these print heads are arranged in a row along a longitudinal axis of the article to be printed, wherein a respective direction of the ink ejected by the respective print nozzles of these print heads and the longitudinal axis of the article to be printed are located in a same printing plane and the respective direction of the ink ejected by the respective print nozzles of these print heads is directed perpendicular to the surface of the article in question to be printed.

[0011] US 2015 / 0035897 A1 discloses a printing machine for printing an object, comprising: a chassis, at least four inkjet print heads, each adapted to direct ink jets onto the object in at least four printing directions, and a system for holding and moving the print heads, said system being attached to the chassis and adapted to move said print heads between a plurality of positions relative to the chassis, said system being configured such that in each of said positions the printing directions are different from one another and extend through a same central axis.

[0012] The invention is based on the object of creating a printing machine with at least one print head, in particular to print a conical article with a print image in good print quality.

[0013] The object is achieved according to the invention by the features of claim 1. The dependent claims relate to advantageous embodiments and / or further developments of the solution found.

[0014] The advantages achievable with the invention consist in particular in the fact that with the proposed printing machine, an article, in particular a glass article, which is designed as a rotary body but does not have an ideal cylindrical shape, but is rather conical and thus has the shape of a cone or a truncated cone, can be printed distortion-free and with precise registration. The distortion-free and precise printing of the outer surface of a conical rotary body is ensured by the fact that the at least one print head is arranged perpendicular to the surface of the article in question during the printing process and that a longitudinal sectional plane running through the print head in question intersects a rotation axis of the article in question. In geometry, a rotary body is a body whose surface is formed by rotating a generating curve around a rotation axis.

[0015] The solution found has proven to be particularly advantageous for printing on conical hollow bodies that rotate during the printing process in series production, in particular on hollow bodies of this type with a runout error of the order of e.g. ± 2 mm, which is a very large runout error compared to articles to be printed on a metallic material, a plastic material, or a fibrous material such as paper, and is almost impossible in practice for articles to be printed on a metallic material, a plastic material, or a fibrous material such as paper. However, this is a common, if not almost always, situation with hollow bodies that are each designed as a glass article. These glass articles are, for example,These are bottles, flacons, or glass packaging whose respective concentricity errors, due to the manufacturing process of these glass articles, are on the order of, for example, ± 2 mm. In a series of such articles to be printed, these concentricity errors are also subject to a wide range. Nevertheless, such hollow articles should also be provided with a high-quality print image on their surface by a printing machine in industrial series production.Until now, when printing on the surface of a conical hollow body, especially one with a concentricity error of the aforementioned magnitude, it was necessary to space the print head in question further from the surface of the hollow body in question than is desirable to produce good print quality in order to avoid a possible collision between the surface of the hollow body in question and the print head in question arranged in the printing machine during the printing process. This is because commercially available print heads for printing using an inkjet printing process are generally designed to be positioned at a very short distance of, for example, 1 mm from the surface to be printed.If the geometry of a hollow body to be printed on, possibly taking into account its associated tolerances, requires the print head to be spaced further than usual from the surface of the hollow body in question, this results in a greater firing distance for the ink droplets ejected by the print head, which generally leads to reduced print quality with regard to the resulting print image. This reduction in print quality is now avoided by the solution found.

[0016] As mentioned, the larger tolerances of hollow bodies made of glass to be printed on compared to other printing materials require a much greater spacing of the print head in question from the surface of the hollow body to be printed. The ink droplets ejected by the print head in question therefore have to travel a significantly longer distance. To achieve this, the ink droplets in question must be larger than when printing on other printing materials, i.e. when printing on hollow bodies made of glass, the ink droplets each contain a comparatively larger amount of ink. This means that these ink droplets must be subjected to greater kinetic energy in order to overcome the air resistance along their flight path.The increased energy requirement to be processed by the print head in question means that the print head in question can only be designed with a very limited print width, although this print width is typically 70 mm for currently commercially available print heads. A further difficulty in creating a print image with a print length exceeding this print width is that, due to the way they are enclosed in their housings, these print heads cannot be aligned in such a way that their respective print widths would seamlessly complement one another to create a print length exceeding the individual print width. Instead, it is necessary to arrange such print heads offset from one another in different printing planes. This requires tracking of the respective print position of the print head in question for distortion-free and precisely registered printing on the outer surface of a conical rotary body.

[0017] In printing terms, registration - also called color register - refers to the matching and / or overlapping of individual printing colors in multi-color printing. Register therefore describes accurate printing over several consecutive print runs. In four-color printing, the four process colors, cyan, magenta, yellow and black, are usually printed one after the other in the correct positions and at least partially on top of each other. The printing colors printed one after the other and partially on top of each other then, when viewed as a whole, result in the printed image. If these printing colors are not in exactly the right position relative to each other, the printed image will appear distorted, i.e. blurry, out of focus or with color shifts, which in any case reduces the quality of the printed image.

[0018] The term "article to be printed" refers here to a real three-dimensional object that occupies a space and has interfaces and a mass. The article to be printed is—as mentioned—preferably a hollow body, in particular a glass article. The article to be printed has a center of mass and a longitudinal extension or longitudinal axis, with which its axis of rotation corresponds during the printing process.

[0019] A three-dimensional orthogonal coordinate system anchored at the center of mass of the item to be printed or at the center of mass of the respective print head has three orthogonal axes: a longitudinal axis, a transverse axis, and a vertical axis. Rotational movement around the respective longitudinal axis is referred to as roll, rotational movement around the respective transverse axis is referred to as pitch, and rotational movement around the respective vertical axis is referred to as yaw.

[0020] The following is based on an industrial printing process in which, in a printing press, at least one print head printing using an inkjet printing process, preferably several print heads each printing using an inkjet printing process, prints a surface of the article in question. Each of these print heads has, enclosed in a housing and at a distance of a few millimeters, e.g., between 1 mm and less than 8 mm, from the surface of the article in question to be printed, at least one row of adjacently arranged print nozzles, wherein each of these print nozzles is designed to eject an ink, and wherein a length of the respective row of print nozzles defines the print width of the respective print head.The print width of each of the print heads printing this article using an inkjet printing process is arranged along the longitudinal axis of the article to be printed and extends over a section of this article to be printed. Since the longitudinal extent of the article to be printed, and thus the length of the print image to be created, is often greater than the print width of the respective print head, the proposed printing machine comprises several print heads with their respective print widths arranged in a row along the longitudinal axis of the article to be printed.The respective direction of the ink ejected from the respective print nozzles by the possibly several print heads arranged in a row along the longitudinal axis of the article to be printed and the longitudinal axis of the article to be printed are located in the same plane, which is also referred to as the printing plane, wherein the respective direction of the ink ejected from the respective print nozzles is directed perpendicular to the printable surface of the article in question in order to produce a high-quality, in particular distortion-free print image. In particular, to create a multi-colored print image, several different printing planes are provided with respect to the surface of the article in question to be printed, wherein the print nozzles arranged in the different printing planes each eject different colored inks, e.g. inks in the process colors cyan, magenta, yellow and black.Since these printing planes each intersect the longitudinal axis of the article to be printed, immediately adjacent printing planes form a V-shaped formation. In the particularly preferred embodiment of the invention, a series of several articles with identical geometries is printed in the printing press, with their geometries exhibiting a wide range within the respective tolerances.

[0021] An embodiment of the invention is illustrated in the drawings and is described in more detail below.

[0022] They show: Fig. 1 shows an arrangement of several print heads jointly printing an article; Fig. 2 shows a first exemplary embodiment of a holder that changes the position of the print heads in space; Fig. 3 shows a second exemplary embodiment of the holder that changes the position of the print heads in space.

[0023] Fig. 1 shows, in a perspective view, a schematic and highly simplified example of an arrangement of several, e.g., four preferably identical print heads 01, each printing using an inkjet printing process, which jointly print at least part of the surface of a conically shaped rotating body 02. This arrangement of print heads 01 is located in a printing press not explained in detail here, the structure and mode of operation of which are known to those skilled in the art. During the printing process, the rotating body 02 to be printed rotates about its rotational axis 03, with a longitudinal axis X2 of the rotating body 02 to be printed forming this rotational axis 03.Each of these print heads 01 is arranged with respect to the surface of the rotary body 02 to be printed such that, at least during the printing process, it is arranged perpendicular to the surface of this rotary body 02 to be printed and that a longitudinal section plane 04 passing through the respective print head 01 intersects the rotation axis 03 of the rotary body 02 to be printed. The respective longitudinal section plane 04 of the respective print head 01 also forms its printing plane 04.

[0024] In the Fig. 1 Several, e.g., two different printing levels 04 are shown, wherein two print heads 01 of the illustrated arrangement arranged in the same printing level 04 are not seamlessly joined to one another, but are arranged in a row in the respective printing level 04, spaced from one another by a mounting gap 06. The two printing levels 04 each intersect the longitudinal axis X2 of the rotating body 02 to be printed, and thus the two rows of print heads 01 form a V-formation in this arrangement.

[0025] The print heads 01 arranged in the two printing planes 04 are preferably arranged in rows offset from one another. Each of these print heads 01 has, on its side facing the surface of the rotating body 02 to be printed, at least one row, preferably several parallel rows of adjacently arranged print nozzles 07, wherein each of these print nozzles 07 is designed to eject an ink and wherein a length of the respective row of print nozzles 07 defines a print width 08 of the respective print head 01. The print width 08 of the respective print head 01 is smaller than a length L02 of the rotating body 02 to be printed, so that with the print width 08 of each print head 01, only a section on the surface of the rotating body 02 to be printed can be printed. The print width 08 of the respective print head 01 is, for example,in a range between 50 mm and 100 mm, preferably 70 mm, whereas the length L02 of the rotary body 02 to be printed and usually also of the print image to be printed on its outer surface is, for example, in a range between 200 mm and 300 mm. The respective rows of adjacently arranged print nozzles 07 of print heads 01 arranged in offset rows in the various printing planes 04 are arranged to complement one another to form a continuous printing line, wherein this printing line is a surface line lying in the respective longitudinal sectional plane 04 running through the respective print heads 01 on the surface of the rotary body 02 to be printed. The at least one print head 01 is or all print heads 01 of this arrangement are arranged at a distance of between 1 mm and less than 8 mm from the surface of the rotary body 02 to be printed on.

[0026] It is provided that a three-dimensional orthogonal coordinate system fixed to the print head, with its origin at a center of mass 09 of the print head 01 in question, has a longitudinal axis X1, a transverse axis Y1, and a vertical axis Z1, wherein the longitudinal axis X1 of the print head 01 in question extends parallel to the print width 08 of this print head 01. A holder 12 holding the print head 01 in question is preferably designed such that the print head 01 in question executes a rotational movement at least about its vertical axis Z1. In addition, this holder 12 of the print head 01 in question is preferably designed to be movable such that the print head 01 in question executes a rotational movement about its transverse axis Y1 and / or about its longitudinal axis X1 in addition to its vertical axis Z1.The rotational mobility of the relevant print head 01 about its vertical axis Z1 and a controlled tracking of the printing position of the relevant print head 01 ensure that at least one print head 01 is always arranged perpendicular to the printing surface of the relevant conically shaped article 02 during the printing process, even if this article 02 has a runout error on the order of magnitude of, for example, ± 2 mm and / or the tolerances of its geometry have a wide range. Thanks to the solution found, the relevant print head 01 can always be positioned in space with reference to the surface of the relevant article 02 thanks to its three-dimensional positionability in such a way that a longitudinal section plane 04 running through the relevant print head 01 intersects a rotation axis 03 of the relevant article 02, whereby the rotation axis 03 of the relevant article 02 is also its longitudinal axis X2.

[0027] According to the invention, a plurality of print heads 01 are provided, each printing the surface of the article 02 in question using an inkjet printing process, wherein these print heads 01 are arranged in a row along the longitudinal axis X2 of the article 02 to be printed, wherein a respective direction of the ink ejected by the respective print nozzles 07 of these print heads 01 and the longitudinal axis X2 of the article 02 to be printed are located in a same printing plane 04 and the respective direction of the ink ejected by the respective print nozzles 07 of these print heads 01 is directed perpendicular to the surface of the article 02 to be printed.With reference to the surface of the article 02 in question to be printed, a plurality of different printing levels 04 are provided, wherein the printing nozzles 07 arranged in the different printing levels 04 each eject the same inks or inks of different colors, wherein immediately adjacent printing levels 04 form a V-formation.

[0028] Furthermore, in addition to the rotatable holder 12 for the respective print head 01, it is preferably provided that the article 02 to be printed is held by a holding device belonging to the printing press and different from the holder 12 holding the respective print head 01. This holding device is designed, for example, as a clamping device which holds the article 02 to be printed by applying a force in opposite directions to its two end faces. Alternatively, this holding device can be designed, for example, as a mandrel holding the article 02 to be printed by means of a negative pressure or as a clamping mandrel. Also, an article-fixed three-dimensional orthogonal coordinate system arranged with its origin in a center of mass 11 of the respective article 02 has the longitudinal axis X2 of the respective article 02 and a transverse axis Y2 and a vertical axis Z2, wherein the longitudinal axis X2 of the respective article 02 is usuallyextends parallel to the rotation axis 03 of this article 02. It is advantageously provided that the holding device of the article 02 in question is designed to be movable in such a way that the article 02 in question executes a rotational movement about its transverse axis Y2 and / or about its vertical axis Z2.

[0029] Fig. 2 shows, in a perspective view, schematically and in a highly simplified manner, a first exemplary embodiment of the holder holding the print head 01 in question, which holder is designed, for example, in such a way that the print head 01 in question executes at least one rotational movement about its vertical axis Z1. In this first exemplary embodiment, a rigid plate 12 rigidly connected to the print head 01 in question is arranged in the printing plane 04 of the print head 01 in question. In the case of a plurality of print heads 01 arranged in the same printing plane 04, these print heads 01, which are preferably arranged in a row, are rigidly connected to the same rigid plate 12. In the case of an arrangement of print heads 01 arranged in a plurality of different printing planes 04, a rigid plate 12 is arranged in each of these printing planes 04, wherein the print heads 01 in question in a specific printing plane 04 are rigidly connected to the rigid plate 12 arranged in this printing plane 04.Three, for example, identical, preferably electrically operated or at least operable actuators 13 are provided, which act on the respective rigid plate 12 at three mutually different points of action A; B; C, for example, each via a ball joint 14 or a coupling 16, and upon their respective actuation change the position of the respective rigid plate 12 and thus the position of the respective at least one print head 01 in space. The respective coupling 16 has, for example, a ball 17 or a cylinder 18 at its respective connection point with the respective rigid plate 12 and / or with the respective actuator 13. The actuators 13 are each designed, for example, as a linear motor, wherein each of these actuators 13 is designed to execute a particularly bidirectional travel path. The three actuators 13 of this first embodiment are controlled by a control unit that, for example, controls the printing process.This control unit is designed in such a way that, in an ongoing printing process, it tracks or at least can track the respective printing position of the relevant print head 01 in accordance with the geometric requirements of the article 02 to be printed, i.e. depending on its surface geometry.

[0030] Fig. 3shows, in a perspective view, schematically and in a highly simplified manner, a second exemplary embodiment of the holder holding the print head 01 in question, which holder is designed, for example, such that the print head 01 in question executes at least one rotary movement about its vertical axis Z1. In this second exemplary embodiment, this holder has a first actuator 21, with which the at least one print head 01 can be moved preferably bidirectionally along its transverse axis Y1. This holder also has a second actuator 22, with which the at least one print head 01 can be rotated preferably bidirectionally about its vertical axis Z1. In addition, this holder has a third actuator 23, with which the at least one print head 01 can be rotated preferably bidirectionally about its longitudinal axis X1.In the case of several print heads 01 arranged in the same printing plane 04, these print heads 01, which are preferably arranged in a row, can each be moved jointly by the respective actuators 21; 22; 23 along their respective transverse axis Y1 and / or rotated about their respective longitudinal axis X1 and / or about their respective vertical axis Z1. These actuators 21; 22; 23, which change the spatial position of the respective print head 01, are preferably electrically actuated or at least actuable and are controlled by a control unit which, for example, controls the printing process. In this second exemplary embodiment, the control unit is also designed such that, during an ongoing printing process, it tracks or at least can track the respective printing position of the respective print head 01 in accordance with the geometric requirements of the article 02 to be printed, i.e. depending on its surface geometry. List of reference symbols

[0031] 01Print head 02Rotation body; article 03Rotation axis 04Longitudinal section plane; printing plane 05- 06Mounting gap 07Print nozzle 08Print width 09Center of mass 10- 11Center of mass 12Plate 13Actuator 14Ball joint 15- 16Coupling 17Ball 18Cylinder 19- 20- 21Actuator 22Actuator 23Actuator APoint of action BPoint of action CPoint of action L02Length X1Longitudinal axis Y1Transverse axis Z1Vertical axis X2Longitudinal axis Y2Transverse axis Z2Vertical axis

Claims

1. Printing machine comprising at least one print head (01), wherein the relevant print head (01) is configured to print, in an inkjet printing process, a surface of an article (02) that rotates during the printing process, wherein a printing width (08) of the relevant print head (01) in each case extends over a section of a length (L02) of the article (02) to be printed, wherein the relevant section in each case extends longitudinally in relation to a longitudinal axis (X2) of the article (02) to be printed, wherein a three-dimensional orthogonal coordinate system, the origin of which is arranged in a center of mass (09) of the relevant print head (01) and which is fixed in terms of the print head, has a longitudinal axis (X1) and a transverse axis (Y1) and a vertical axis (Z1), wherein the longitudinal axis (X1) of the relevant print head (01) extends parallel to the printing width (08) of this print head (01), wherein a plurality of print heads (01) that each print the surface of the relevant article (02) in an inkjet printing process are provided, wherein these print heads (01) are arranged in a row longitudinally in relation to the longitudinal axis (X2) of the article (02) to be printed, wherein a respective direction of the ink ejected by the respective printing nozzles (07) of these print heads (01) and the longitudinal axis (X2) of the article (02) to be printed are situated in the same printing plane (04) and the respective direction of the ink ejected by the respective printing nozzles (07) of these print heads (01) is in each case oriented perpendicularly to the surface of the relevant article (02) to be printed, wherein a plurality of different printing planes (04) are provided with respect to the surface of the relevant article (02) to be printed, wherein directly adjacent printing planes (04) create a V formation, wherein a control unit is provided, wherein this control unit is designed so as to track, or at least be able to track, a respective printing position of the relevant print head (01) during an ongoing printing process based on a surface geometry of the article (02) to be printed, and wherein a mount holding the relevant print head (01) is provided, characterized in that the mount of the relevant print head (01) is designed so as to be movable in such a way that the relevant print head (01) carries out a rotational movement at least about its vertical axis (Z1), wherein the mount that changes the position of the relevant print head (01) in space comprises a first positioning drive (21), by way of which the at least one print head (01) can be displaced along its transverse axis (Y1), wherein this mount comprises a second positioning drive (22), by way of which the at least one print head (01) can be rotated about its vertical axis (Z1), and wherein this mount comprises a third positioning drive (23), by way of which the at least one print head (01) can be rotated about its longitudinal axis (X1).

2. Printing machine according to claim 1, characterized in that the mount of the relevant print head (01) is designed so as to be movable in such a way that the relevant print head (01) not only carries out a rotational movement about its vertical axis (Z1), but also about its transverse axis (Y1) and / or about its longitudinal axis (X1).

3. Printing machine according to claim 1 or 2, characterized in that each of the print heads (01), during the printing process, is arranged perpendicularly to the surface of the relevant article (02) to be printed, wherein a longitudinal section plane (04) extending through the relevant print head (01) intersects an axis of rotation (03) of the relevant article (02), and wherein the axis of rotation (03) of the relevant article (02) is its longitudinal axis (X2).

4. Printing machine according to claim 1 or 2 or 3, characterized in that each of the print heads (01) is in each case arranged at a distance of between 1 mm and less than 8 mm from the surface of the relevant article (02) to be printed.

5. Printing machine according to claim 1 or 2 or 3 or 4, characterized in that each of the print heads (01) comprises at least one row of printing nozzles (07) arranged next to one another, wherein a length of the relevant row of printing nozzles (07) defines the printing width (08) of the relevant print head (01).

6. Printing machine according to claim 1 or 2 or 3 or 4 or 5, characterized in that the article (02) to be printed is held in a holding device belonging to the printing machine, wherein a three-dimensional orthogonal coordinate system, the origin of which is arranged in a center of mass (11) of the relevant article (02) and which is fixed in terms of the article, comprises the longitudinal axis (X2) of the relevant article (02) and a transverse axis (Y2) and a vertical axis (Z2), and wherein the holding device of the relevant article (02) is designed so as to be movable in such a way that the relevant article (02) in each case carries out a rotational movement about its transverse axis (Y2) and / or about its vertical axis (Z2).

7. Printing machine according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized in that print heads (01) arranged in the same printing plane (04) can in each case be jointly displaced along their respective transverse axis (Y1) and / or rotated about their respective longitudinal axis (X1) and / or their respective vertical axis (Z1) by the relevant positioning drives (21; 22; 23).

8. Printing machine according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7, characterized in that the positioning drives (21; 22; 23) that change the position of the relevant print head (01) in space are, or at least are able to be, electrically actuated.

9. Printing machine according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8, characterized in that the positioning drives (21; 22; 23) that change the position of the relevant print head (01) in space are controlled by the control unit.