EP2095949B1 - Method and device for printing objects - Google Patents

Abstract

The device has a printing unit comprising flexo printing works mounted on a carrier unit (8). The printing unit is provided with a raster roller and a pneumatic cylinder. An accommodating pin (1) accommodates an object, and a measurement mechanism measures a surface of the object accommodated by the accommodating pin and/or measures a surface of the accommodating pin. An adjusting piston (7) adjusts an inclination of the printing works regarding the accommodating pin and/or distance of the printing forms of the accommodating pin. An independent claim is also included for a method for printing of objects.

Description

The invention relates to an apparatus and a method for printing on objects, in particular cylindrical objects, in particular with a high-pressure process such as the flexographic printing process.

When printing objects such as glasses, bottles (made of plastic or glass) or tubes and, among other things, films and paper, the screen printing process is often used. This printing method has the advantage that the print quality is relatively independent of small variations in the distance between the screen printing fabric and the object to be printed, since the ink is pressed with a doctor blade through the flexible screen printing fabric on the object to be printed.

However, the screen printing method also has disadvantages compared with other known printing techniques. For example, it is possible to print finer structures with high-pressure processes, such as the flexographic printing process, which is particularly advantageous when images are to be printed with high resolution-possibly even multicolored.

However, in high and flat printing processes, the print quality is sensitive to accurate alignment of the printing cylinder with respect to the item to be printed. The distance between the printing cylinder and the object must be kept as constant as possible over the entire area to be printed. Already deviations of 0.01 - 0.02 mm lead to the fact that the quality of the printed image decreases strongly.

This poses no problem with sheetfed and web printing since there the sheet to be printed or the web to be printed is passed over an impression cylinder which is mounted at both ends.

When printing objects, in particular cylindrical objects, the object is often completely or partially closed on one side, for example glasses, bottles made of plastic or glass or tubes for cosmetics, which are printed before filling and closing and therefore a substantially cylindrical shape to have.

To be printed objects are taken before printing by a holding device and held during printing of this. Cylindrical objects For example, can be pushed onto a mandrel and held by this, for example, by a radial expansion of the mandrel. Such a receiving or expanding mandrel is in the German utility model DE 20 2004 019 382 U1 described.

In another possible holding device of the object to be printed is held by the generation of negative pressure within the holding device on this. It is also often mechanical clamping devices are used, which are placed on the cylindrical object and so hold the object during the printing process.

The holding device is mounted on one side. A storage on the opposite side is not possible because there the recorded object is often (partially) closed.

It is also not possible to support the holding device with a counter-pressure cylinder, since the holding device rotates during printing around an axis and thus the already printed surface of the object received by the holding device is in contact with the impression cylinder. As a result, the ink would reach the impression cylinder and smear on the object to be printed.

During printing, however, a force is exerted on the holding device via the printing cylinder. Due to unavoidable tolerances in the manufacture of the holding device and its storage, this leads to the fact that the holding device dodges slightly in the direction of the force exerted by the pressure cylinder force. This evasive movement is as in Fig. 3 shown for a mandrel, at the unsupported end of the mandrel greater than the stored end, so that the inclination of the mandrel changes with respect to the impression cylinder.

Furthermore, during the operation of the printing device whose temperature changes, resulting in length changes, which lead to a deviation of the position of the components of the holding and / or printing device relative to the initial position.

Finally, holding devices can be converted in order to adapt them to the respective print job. In this case, due to unavoidable manufacturing tolerances often can not be ensured that the position of the components of the holding device after the conversion exactly matches the position before the conversion.

For these reasons, the relative position of holding device and impression cylinder changed, resulting in no longer optimal printing of the recorded by the holding device subject.

Other reasons for print quality degradation may be a varying wall thickness of the articles to be printed, whereby the distance of the printing cylinder to the surface of the article either during printing of an object or between the printing operations on different objects varies.

Finally, even when using a rotary transfer system for printing, in which, for example, different colors are applied to different workstations, production-related tolerances can lead to a non-exact alignment between the printing units of the rotary transfer system and the transport device for the holding devices. As a result, the distance between the printing cylinder to the surface of the object to be printed between the individual workstations may vary, which also leads to a reduction in print quality.

In the printing apparatus according to the US 2005/0081725 A1 The above problems are avoided by holding the object to be printed on two sides during the printing process. The holder of the object to be printed allows adjustment of the register between different printing stations.

In the printing apparatus according to the DE 37 43 676 A1 the object to be printed is held on one side on a spindle. Again, an adjustment of the position of the printed image with respect to the circumferential direction of the article is possible.

It is therefore an object of the present invention to provide a device for printing cylindrical objects, which allows a high-quality printing of the objects even with a high-pressure unit, even if the distance between the object and impression cylinder varies.

This object is achieved by a device for printing objects with the features of claim 1.

An article printing apparatus according to the present invention comprises a printing unit having a printing unit mounted on a support unit. The printing unit has at least one anilox roller for picking up the ink and a printing cylinder to which the ink is at least partially transferred from the anilox roller. The printing unit can also have additional intermediate rollers for transferring the color.

On the printing cylinder, a printing plate or sleeve may be attached according to the printing method with which the device of the invention is to be used, for example a planographic printing plate (for example for offset printing) or a high-pressure plate (for example for flexographic printing).

A device according to the invention further comprises a holding device, from which an object to be printed, such as a glass, a bottle or a tube can be received. Preferably, the holding device is a receiving mandrel having an outer diameter which is only slightly smaller than the inner diameter of the articles to be printed. An object to be printed can then be easily pushed onto the arbor.

One possible embodiment of the holding device provides that compressed air is conducted into the receiving mandrel, whereby elastic elements in the interior of the receiving mandrel expand and metal strips which form the surface of the receiving mandrel press outward. Characterized the object to be printed is held firmly on the mandrel and can be rotated by a rotation of the mandrel about its own longitudinal axis, so that the object are printed circumferentially with the pressure plate mounted on the printing plate.

In another possible holding device of the object to be printed is held by the generation of negative pressure within the holding device on this. Another embodiment uses mechanical clamping device.

If the article to be printed on the inside is not cylindrical, the holding device can also be adapted to the inner shape of the object to be printed.

A device according to the invention further comprises a measuring device with which the surface of an object received by the holding device can be measured. Another possibility is to measure the surface of the holding device. Preferably, the surveying device is mounted in a known orientation to a main body of the device according to the invention and can be a measurement of the surface of a received by the holding device object or the surface of the holding device at one or more points either fixed holding device or during rotation of the holding device to a Perform axis. By measuring the surface of the object or the holding device, it is understood that the position of points on the surface relative to a known point is determined, for example, by a main body of the device.

It is thereby possible to carry out a measurement of the circumferential profile of the article or the holding device to be printed at one or more points along its length.

However, it is not always necessary to measure the surface completely. For example, to determine the inclination of the holding device, it is sufficient to determine at two points the distance from the surface of an object received on the holding device or the holding device to the measuring device.

By means of such a measurement, it is possible to determine which orientation an object or holding device received by the holding device or the holding device has, for example, the inclination of the holding device. In addition, it can be determined whether during a rotation of the holding device about an axis, the distance from the surface of an object received by the holding device to the measuring device is constant or fluctuates, ie. whether the material thickness of the article is constant.

It can also be determined whether the material thickness of all objects to be printed is the same size, or whether different objects have different material thicknesses.

Finally, a device according to the invention further comprises a control device with which the inclination of the printing unit with respect to the holding device and / or the distance of the printing unit and in particular of the printing cylinder from the holding device can be adjusted, based on the measurement of the surface of the object or the holding device. Preferably, the inclination and / or the distance of the printing unit is adjusted so that an optimum printing result is achieved on the previously measured with the surveying object.

In a preferred embodiment of the device according to the invention, the control device has at least one adjusting element for adjusting the inclination of the printing unit in relation to the holding device and / or the distance of the printing unit from the holding device. In a particularly preferred embodiment, the adjusting element is a setting cylinder which is fastened to the carrier unit at a first end and which is fastened to the base body of the device according to the invention at a second end.

This makes it possible to change the orientation of the carrier unit and thus the pressure unit mounted thereon with respect to the base body. Preferably, the control device has two actuating cylinders which are each fastened to the carrier unit at a first end and which are each fastened at a second end to the main body of the device according to the invention. In this case, the first actuating cylinder is preferably arranged above the first end face of the printing cylinder and the second actuating cylinder is preferably arranged above the second end face of the printing cylinder. The adjusting cylinders can also be arranged below the printing cylinder. The drive of the actuating cylinder is preferably carried out with a linear or servo motor.

In a further particularly preferred embodiment of the device according to the invention the actuating cylinder is rotatably mounted at its first end about an axis perpendicular to the direction of adjustment to the carrier unit and at its second end about an axis perpendicular to the direction of adjustment rotatably mounted on the base body.

Thus, the inclination of the printing unit with respect to the holding device and / or the distance of the printing unit and in particular of the printing cylinder can be adjusted by the holding device so that an optimum printing result is achieved on the object.

In a device according to the invention, the control device of which has only a single control element (for example only one actuating cylinder), it is not possible to adjust the distance of the printing mechanism and in particular of the pressure cylinder from the holding device. However, it can be adjusted with respect to the holding device, the inclination of the printing unit. Preferably, the single actuating cylinder is arranged above one of the two end faces of the printing cylinder, while the carrier unit is rotatably attached to the main body above the other of the two end faces of the printing cylinder.

According to the invention, a single actuator can be used, which allows the adjustment of both the inclination of the printing unit with respect to the holding device and the distance of the printing unit and in particular of the printing cylinder of the holding device.

In a further particularly preferred embodiment of the device according to the invention, the measuring device has at least one sensing device for mechanical scanning the surface of the recorded on the mandrel cylindrical object or the surface of the holding device.

Such a sensing device consists for example of a probe, which is guided partially displaceable in a housing. The housing of the sensing device is connected to the Grundköper the device according to the invention and the probe is applied during the measurement of the surface to be measured. In this case, the orientation of the probe is preferably substantially perpendicular to the surface of the article in the point where the probe rests against the mandrel or the object. By changing the inclination of the holding device or the wall thickness of the object to be printed, the probe is moved with respect to the housing of the sensing device. This displacement can be measured and from this information on the arrangement of the surface can be obtained. Such a probe is offered for example by the company Heidenhain under the name "ST 3077".

However, the measuring device can also work with optical or acoustic methods in order to measure the respective surface.

In a further particularly preferred embodiment of the device according to the invention, the device is a rotary transfer machine with a plurality of work stations, between which an object to be printed can be transported with a holding device. In this case, the measuring device is installed at a first work station and the printing unit, with which the object is printed, and the control device are installed at a second workstation. Preferably, in this case also at the first work station, a printing unit is installed, with which the printing process can be simulated to determine the change in the inclination of the holding device when the impression cylinder presses against the object received by the holding device.

Typically, rotary transfer machines are used in printing cylindrical objects when several steps are required during printing. Work steps can be, for example, printing with one color in each case in order to obtain a multicolored imprint on the object as a result. Another possible operation is, for example, pre-treating the surface of the article to be printed in order to improve the adhesion of the colors on the surface. Such a process is known under the name UVitro and is described in the European patent EP 1 148 036 B1 described. Also, as another possible operation, treating the article before or after printing with a varnish is possible.

According to the invention, the measurement of the surface of an object to be printed picked up by a holding device is now also provided as a working step on a rotary indexing machine.

This is particularly advantageous if the measurement of the surface of the object to be printed or the holding device should not only take place in one or more points with a fixed holding device, but if the surface of the object to be printed or the holding device during a full revolution of the Holding device should be made. Since the measurement of the surface can not take place simultaneously at the point that is being printed, the measuring device must be arranged offset to the printing unit. For example, the measuring device can be arranged relative to the printing unit with respect to the holding device.

This then leads to the fact that the holding device has to perform only half a revolution before the measured part of the surface of the object to be printed comes to the printing unit and can be printed there. Thus, in order to obtain a circumferential imprint on the cylindrical article, it is necessary for the holding device to make one and a half revolutions, thereby significantly reducing the throughput of the rotary transfer machine.

It is therefore advantageous to arrange the measuring device on an otherwise free workstation of the rotary transfer machine, so that an object to be printed or the holding device can be measured at this workstation with a full rotation of the holding device, while at the workstation with the first printing unit nor a previous object is printed. As a result, printing of the object is made possible with only one full turn of the holding device and thus saves half a turn.

If it is known that the objects to be printed have a sufficiently constant wall thickness, and only the manufacturing tolerances of the mandrel are to be compensated, it is sufficient to measure all mandrels only once before the beginning of the printing process and then the individual printing units to the respective Adjust mandrel.

In a preferred embodiment of the device according to the invention, the device has a memory device for storing the data measured by the measuring device of the surface of the receiving mandrel or of the cylindrical object accommodated on the receiving mandrel.

The storage of the data of the surface can be done, for example, at a first workstation of a rotary transfer machine. When printing the article to other workstations of the rotary transfer machine can then be accessed on the stored data.

An inventive device for printing cylindrical objects can be used with all printing methods in which a printing plate o.ä. mounted on a printing cylinder.

In a particularly preferred embodiment of the device according to the invention, the printing unit is a flexographic printing unit.

The present invention also relates to a method of printing objects with a device as described above. This device comprises a printing unit with a printing unit mounted on a carrier unit, which has an anilox roller and a printing cylinder, and a holding device for receiving the object to be printed.

In one step of the method according to the invention, the surface of the cylindrical object or holding device received by the holding device is measured. The measuring mandrel or article may be measured at one or more points either when the holding device is stationary or during rotation of the holding device about an axis.

It is not necessary to measure the surface completely. For example, to determine the inclination of the holding device, it is sufficient to determine the distance from the surface at two points.

By means of such a measurement, it is possible to determine which orientation an object or holding device received by the holding device or the holding device has, for example, the inclination of the holding device. In addition, it can be determined whether during a rotation of the holding device about an axis, the distance from the surface of an object received by the holding device to the measuring device is constant or fluctuates, ie. whether the material thickness of the article is constant.

It can also be determined whether the material thickness of all objects to be printed is the same size, or whether different objects have different material thicknesses.

In a further step of the method according to the invention, the inclination of the printing unit in relation to the holding device and / or the distance of the printing unit from the holding device is adjusted. For this, the data obtained in the step of measuring the surface of the object are used. This makes it possible to optimally adjust the inclination and / or distance of the printing unit to the object to be printed.

In a further step of the method according to the invention, the object received by the holding device is printed with the printing unit. Due to the optimal alignment of the

Printing unit with respect to the holding device and thus the object to be printed can achieve an optimal printing result.

In a preferred embodiment of the method according to the invention, each of the mentioned method steps is completely completed before the next step is started. This means that initially the surface of the object to be printed or the holding device is measured to the desired extent. For example, the inclination of the holding device can be determined while the impression cylinder exerts a force on the object received by the holding device, by determining the distance of the surface of the object from a measuring device.

Only then is the inclination of the printing unit in relation to the holding device and / or the distance of the printing unit set by the holding device. This setting is then maintained while the item is being printed on the printer. Fluctuation of the wall thickness of the cylinder-shaped article to be printed can not be compensated for in this serial execution of the process steps, but it is possible to reduce tolerances in the components, e.g. to compensate for the storage of the holding device.

In this embodiment of the method, the step of measuring the surface is preferably performed on a first work station of a rotary transfer machine, and the two steps of adjusting the inclination and / or distance of the printing unit and the printing of the object are preferably performed on a second workstation of the rotary transfer machine. Thereby, it is possible to carry out the step of measuring the surface of a first object simultaneously with the steps of adjusting the inclination and / or distance of the printing unit and the printing of a second object.

In a further preferred embodiment of the method according to the invention, the steps of adjusting the inclination and / or distance of the printing unit and printing on the cylindrical object are carried out simultaneously, i. the inclination of the printing unit relative to the arbor and / or the distance of the printing unit from the arbor are adjusted continuously during one rotation of the arbor. In addition to compensating for tolerances in the components, this also makes it possible to compensate for fluctuations in the wall thickness of the cylindrical object to be printed.

In a further preferred embodiment of the method according to the invention, the step of measuring the surface is at least partially concurrent with the step of adjusting the inclination of the printing unit with respect to the holding means and / or the distance of the printing unit from the holding means and / or the printing step of the object received by the holding device.

For this purpose, the measuring device and the printing cylinder of the printing unit are arranged offset around the holding device. Preferably, the measuring device and the printing cylinder of the printing unit are arranged opposite one another. It is then possible to measure the surface and use the data obtained to adjust the inclination and / or distance of the printing unit when the holding device has made half a turn.

In a further preferred embodiment of the method according to the invention, the measurement of the surface of the object to be printed or the surface of the holding device with a sensing device takes place. Such a sensing device consists for example of a probe, which is guided partially displaceable in a housing. The housing of the sensing device is connected to the basic body of the device according to the invention and the probe abuts the surface during the measurement. The orientation of the probe is preferably substantially perpendicular to the surface in the point where the probe rests against the object or the holding device. By changing the inclination of the holding device or the wall thickness of the object to be printed, the probe is moved with respect to the housing of the sensing device. This displacement can be measured and from this information about the arrangement of the surface of the recorded by the holding device to be printed object or the holding device can be obtained.

In a further preferred embodiment of the method according to the invention, the data obtained when measuring the surface are stored in a memory device. In a particularly preferred embodiment, then the adjustment of the inclination of the printing unit in relation to the holding device and / or the distance of the printing unit from the holding device based on the data stored in the storage device. It is thus also possible to optimally set several printing units (for example for different colors) at different workstations of a rotary transfer machine for the object being printed.

The storage of the data of the surface can be done, for example, at a first workstation of a rotary transfer machine. When printing the article to other workstations of the rotary transfer machine can then be accessed on the stored data.

The inventive method for printing cylindrical objects can be used with all printing methods in which a printing plate o.ä. mounted on a printing cylinder.

In a further preferred embodiment of the method according to the invention, the printing on the cylindrical mandrel received on the mandrel is effected with a flexographic printing unit in a flexographic printing process.

The device according to the invention and the method according to the invention are suitable for printing both substantially cylindrical objects and objects, whose outer shape deviates from a cylinder. For objects whose outer shape deviates from a cylinder, this deviation is compensated during the rotation of the holding device by the at least one adjusting element of the device according to the invention. For example, can be printed with a device according to the invention objects whose cross-section is perpendicular to a longitudinal axis oval or egg-shaped. It is also possible to print flat objects such as foils or paper.

• Fig. 1 eine räumliche Darstellung einer erfindungsgemäßen Vorrichtung zum Bedrucken zylinderförmiger Gegenstände in einer Rundtaktanlage;
• Fig. 2 eine schematische Darstellung der Flexodruckeinheit der Vorrichtung aus Fig. 1;
• Fig. 3 eine Seitenansicht eines Aufnahmedorns (Halteeinrichtung) der Vorrichtung aus Fig.1;
• Fig. 4 eine schematische Seitenansicht der Flexodruckeinheit aus Fig. 2; und
• Fig. 5 eine bevorzugte Ausführungsform einer Flexodruckeinheit mit einer Steuerungseinrichtung zum Einstellen von Abstand und/oder Neigung des Druckwerks.

Reference to the drawing, the invention is explained in detail below. It shows:

• Fig. 1 a spatial representation of an apparatus according to the invention for printing cylindrical objects in a rotary transfer system;
• Fig. 2 a schematic representation of the flexographic printing unit of the device Fig. 1 ;
• Fig. 3 a side view of a receiving mandrel (holding device) of the device Fig.1 ;
• Fig. 4 a schematic side view of the flexographic printing from Fig. 2 ; and
• Fig. 5 a preferred embodiment of a flexographic printing unit with a control device for adjusting the distance and / or inclination of the printing unit.

In Fig. 1 an inventive device for printing objects is shown, which can be installed on a workstation of a rotary transfer system. A simplified, schematic representation of the printing unit and the mandrel of the device is in Fig. 2 to see.

On a receiving mandrel (1), which receives and fixes the printing medium (ie, the cylindrical object to be printed) acts an imaging pressure cylinder (2) on which a flexographic printing plate is fixed, which transfers the ink from the anilox roller (3) on the printing medium , The regulation of the ink supply of the anilox roller (3) is effected by a chamber doctor blade system (4). In this, the excess ink is stripped by a doctor blade from the anilox roller. The amount of ink volume to be transferred is done by selecting from anilox rollers with different rulings, so different dense and different deep engravings on the surface of the anilox roller (3).

Fig. 3 shows a side view of the mandrel (1), to which a force F, which comes about, for example, by the pressure cylinder not shown in this figure, acts. The one-sided storage (6) of the mandrel (1), which is inevitable due to the pressure medium in many cases, since the body to be printed on one side of the cylinder is already closed (partially), justified tolerances with respect to the synchronization and the positional stability. These cause the mandrel (1) under the influence of the force acting on it F on the non-stored side dodges down.

Fig. 4 shows the side view of a flexographic printing unit, as well as to be regulated degrees of freedom of the roller assembly.

The vertical distance between the anilox roller (3) and the impression cylinder (2) refers to the entire length of the anilox roller (3). This degree of freedom is independent of any tolerances of the mandrel (1) or variations in the wall thickness of the pressure medium. It is thus sufficient to adjust this degree of freedom once after the attachment of the printing plate on the printing cylinder (2).

The distance between the pressure roller (2) and the receiving mandrel (3) is a degree of freedom that can be adjusted with a device according to the invention. A regulation with respect to this degree of freedom relates equally to the printing cylinder (2) and to the anilox roller (3), since these are mounted together on a carrier unit.

Another degree of freedom which can be set with a device according to the invention is the parallelism of pressure cylinder (2) and receiving mandrel (1). A change in position within this degree of freedom relates both to the printing cylinder (2) and to the anilox roller (3), since these are mounted together on a carrier unit. By changing the inclination of this carrier unit, the parallelism between the impression cylinder (2) and mandrel (1) can be adjusted.

Finally, another degree of freedom is the longitudinal position of the print image on the print medium located on the pickup mandrel (1). This degree of freedom relates to the printing cylinder (2) as well as to the anilox roller (3), since these are mounted together on a carrier unit. Also, this degree of freedom is independent of any tolerances of the mandrel (1) or variations in the wall thickness of the pressure medium. It is thus sufficient to adjust this degree of freedom once after the attachment of the printing plate on the printing cylinder (2).

So there remain the arrows in Fig. 4 indicated degrees of freedom of the distance between the impression cylinder (2) and mandrel (1) (or the object held on the mandrel (1)), which must be set before printing a print medium on the mandrel (1) or tracked during printing.

Also in Fig. 4 schematically illustrated are two sensors (5), with which the distance between the surface of a recorded on the mandrel (1) recorded pressure medium or the surface of the receiving mandrel and the sensors can be measured. From these two distances, the inclination of the receiving mandrel (1) can be determined when a force acts on it by the pressure cylinder (2). The two sensors are sensing devices that consist of a probe that is slidably guided partially in a housing. The housing of the sensing device is connected to the base body (not shown) of the printing device and the probe abuts the surface during the measurement. Changes in the distance between the surface and the sensor housings therefore lead to a displacement of the probe relative to the housing and can thus be measured. Fig. 5 shows a preferred embodiment of a flexographic printing unit with a control device for adjusting the inclination of the printing unit (2, 3, 4) with respect to the mandrel (1) and / or the distance between the printing unit (2, 3, 4) and mandrel (1). The printing unit is mounted on a carrier unit (8).

By changing the length of the two actuating pistons (7), one end of which is fastened to the carrier unit (8) and whose other end is fastened to a base body (9), the inclination and / or spacing of the printing unit (2, 3, 4) can be adjusted. be set.

The deviation of the parallelism between the receiving mandrel (1) and the impression cylinder (2) determined via the sensors (5) can be compensated by means of the two adjusting pistons (7). This is done by the two adjusting pistons (7) correct the adjustment angle between the pressure cylinder (2) and the mandrel (1). For example, the length of one of the two actuating pistons (7) can be changed while the length of the other remains unchanged, or it can be extended an actuating piston and simultaneously shortened the other.

To compensate for the manufacturing tolerances of the wall thickness of the cylinder to be printed, which is located on the mandrel (1), a vertical adjustment of the position of the carrier unit (8) is made with the printing unit mounted thereon by the two adjusting pistons (7) parallel Change the position of the impression cylinder (2). For example, the length of both control pistons (7) can be extended or shortened to the same extent.

Both settings can also be controlled simultaneously, for example, by extending both control pistons (7), but one more than the other. This then leads to a change in the inclination angle of the printing unit while reducing the distance between the impression cylinder (2) and the mandrel (1).

This ensures that the pressure cylinder (2) and the pressure medium located on the mandrel (1) contact each other in an optimum manner for the printing process and this process is monitored and regulated reliably.

LIST OF REFERENCE NUMBERS

1

Mandrel (holding device)

2

pressure cylinder

3

anilox roller

4

Chambered doctor blade system

5

sensors

6

Storage of the mandrel

7

actuating piston

8th

support unit

9

body

Claims (16)

1. Apparatus for the printing of objects, comprising

   (a) a printing unit with a printing mechanism mounted on a support unit (8), the printing mechanism comprising an anilox roll (3) and a printing cylinder (2),

   (b) a holding device (1) for receiving an object, and

   (c) a control device (7) for adjusting the incline of the printing mechanism (2, 3, 4) with respect to the holding device (1) and/or the distance of the printing mechanism (2, 3, 4) from the holding device (1),
   characterized by

   (d) a measuring device (5) for measuring the surface of the object received by the holding device (1) or for measuring the surface of the holding device,

   (e) wherein adjusting the incline and/or the distance of the printing mechanism (2, 3, 4) with respect to the holding device (1) is based on the measurement of the surface of the object or the holding device (1).
2. Apparatus according to claim 1, wherein the control device comprises at least one adjusting element (7) for adjusting the incline of the printing mechanism (2, 3, 4) with respect to the holding device (1) and/or the distance of the printing mechanism (2, 3, 4) from the holding device (1).
3. Apparatus according to claim 2, wherein the adjusting element is a setting piston (7), on a first end being mounted to the support unit (8) and on a second end being mounted to a base body (9).
4. Apparatus according to claim 3, wherein the setting piston (7) on its first end is mounted to the support unit (8) rotatable around an axis perpendicular to the adjusting direction and on its second end is mounted to the base body (9) rotatable around an axis perpendicular to the adjusting direction.
5. Apparatus according to one of the previous claims, wherein the measuring device comprises at least one sensing device (5) for the mechanical, optical and/or acoustical scanning of the surface of the object received by the holding device (1) or the surface of the holding device (1).
6. Apparatus according to one of the previous claims, wherein the apparatus is a rotary transfer machine with several workstations, wherein the measuring device (5) is installed at a first workstation and wherein the printing unit (2, 3, 4) and the control device (7) are installed at a second workstation.
7. Apparatus according to one of the previous claims, wherein the apparatus comprises a memory device for storing the surface data measured by the measuring device (5).
8. Apparatus according to one of the previous claims, wherein the printing mechanism is a flexo printing unit (2, 3, 4).
9. Method for printing of objects with an apparatus for printing of objects, comprising a printing unit with a printing mechanism mounted on a support unit (8), the printing mechanism comprising an anilox roll (3) and a printing cylinder (2), and the apparatus comprising a holding device (1) for receiving an object, wherein the method comprises the following steps:

   (a) measuring the surface of the object received by the holding device (1) or the surface of the holding device,

   (b) adjusting the incline of the printing mechanism (2, 3, 4) with respect to the holding device (1) and/or the distance of the printing mechanism (2, 3, 4) from the holding device (1) based on measuring the surface of the object or the holding device,

   (c) printing the object received by the holding device (1) with the printing mechanism (2, 3, 4).
10. Method according to claim 9, wherein every step is fully completed before starting the next step.
11. Method according to claim 9, wherein the adjusting of incline and distance of the printing mechanism (2, 3, 4) occurs continuously during the printing of the object received by the holding device (1).
12. Method according to claim 9 or 11, wherein measuring the surface occurs at least partially simultaneously with adjusting the incline and/or the distance of printing mechanism (2, 3, 4) and/or with printing of the object received by the holding device (1).
13. Method according to one of claims 9-12, wherein measuring of the surface occurs by mechanical, optical and/or acoustical scanning of the surface with a sensing device (5).
14. Method according to one of claims 9-13, wherein the data obtained from measuring the surface are stored in a memory device.
15. Method according to claim 14, wherein adjusting the incline and/or the distance of the printing mechanism (2, 3, 4) occurs by means of the data stored in the memory device.
16. Method according to one of claims 9 - 15, wherein printing the object received by the holding device (1) is carried out with a flexo printing unit (2, 3, 4).

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