EP2605909B1 - Apparatus and process to print containers - Google Patents

Description

The invention relates to an apparatus and a method for printing on containers, preferably by means of ink jet printing, on a preferably continuously rotating machine with treatment stations, which have the necessary for printing the container printheads.

Containers, such as bottles and packages, are usually labeled so that consumer information can be attached. It is also known to apply markers or other information to the package with ink jet printers to allow for customizations that label printing does not allow. Such printing systems are monochrome and limited to a few printing dots per line.

To apply a multi-color printing by means of inkjet printers on containers, several monochrome printheads are successively and correspondingly offset so arranged that, depending on the number of colors, an always uniform distance between the individual pressure points is achieved. This is possible with an adjustment to a machine with several printheads arranged one after the other. The packaging material and the print heads are guided past each other at a constant speed. The performance of such a machine is therefore dependent on the printing speed of a respective printhead. Although this is practicable for absorbent packaging materials, for other materials such as metals, glass or plastic, on the other hand, the ink must either be dried by heat or hardened by crosslinking by means of UV or electron beams. This procedure is to be applied after the printing of each ink layer, which increases the length of such machines. If you want to increase the power, so Either several printing systems must be connected in parallel or a different arrangement must be selected.

When in the DE 10 2008 049 241 A1 In the case of a device for applying a multicolored print image to a container, several modules are connected in series, in which different treatment steps, such as pretreatment, printing, drying and checking, are carried out.The containers are transferred from one module to the next, so that each time a new positioning and adjustment is required This affects the accuracy of the printed image and reduces the throughput speed.

From the WO 2004/009360 A1 a device is known in which the containers are each arranged on a mandrel serving as a container carrier during printing. With several printheads distributed around the mandrel, a colored print image consisting of several color sets is applied to the containers while rotating the mandrel. The mandrels are provided on a circumferentially driven transport element, with which the containers are moved during printing on a transport path formed between a container inlet and a container outlet.

The DE 10 2007 050 490 A1 describes an apparatus and a method for printing containers with a plurality of print heads operating according to the principle of ink-jet printing, for producing partial print images of the print image to be applied to the container outer surface. The containers are moved during printing by means of a transport element designed as a carousel, wherein the printing units arranged on the carousel are also moved. In order to apply the partial printing images with the individual printheads of a printing unit to the containers, the printheads for a printhead change are switched on and switched off in such a way that a printhead located in a printing position on the relevant container exits from the printing position out and another printhead is movable into the printing position. The movement of the printheads takes place in the same horizontal plane in which the carousel rotates.

The industrial use of all previously discussed systems should be carried out at high capacities, for example in bottling plants with up to 36,000 bottles per hour. Here, the bottles and thus also the printhead are transported at a speed of about 1.5 m / s, so that the drops of paint are exposed to an air flow, which can affect the print quality.

Object of the present invention is therefore to achieve a high printing performance in the printing of containers on a rotating machine with reliable function and high print quality.

This object is achieved in a device of the type mentioned above with the present invention essentially in that the printheads and optionally further required for pre- and post-treatment of the devices substantially one above the other in a transport plane preferably to the container by about 90 ° inclined path are arranged, and that the machine has transport elements for moving the container along the inclined path.

Unlike the one from the DE 10 2008 049 241 A1 known plant is the multicolor printing of the container in each case in a single treatment station, so that a transfer and re-centering between the individual stations is not required. In addition, the bottle always remains in its printing position and the angle of rotation is always known during the printing process. As a result, the printing precision can be increased significantly, especially with multi-color printing.

Unlike the one from the DE 10 2007 050 490 A1 known system, the containers are moved for printing in a direction substantially perpendicular to the transport direction of the rotating machine. Again, the assignment of container position and print head is much easier, since only the vertical displacement is taken into account. In addition, the printing units can be made narrower so that much more printing units can be arranged on the rotating machine and the throughput of the system can be increased.

According to a preferred embodiment of the invention, the treatment stations in the various levels on printheads, means for crosslinking the ink by means of auxiliary power and / or a plasma torch or the like for the surface pre-treatment before printing on. Thus, the desired multicolor print image can be completely applied in a treatment station.

If the inlet and outlet of the treatment stations lie in one plane, the transfer between the individual treatment stations and the overall structure of the machine can be simplified.

In a further development of the invention, a turntable for receiving the containers and their rotation is provided within the treatment stations, which is driven in particular via a servo motor or a stepper motor. The arranged on the turntable container can be guided past the fixed print head, when the print image is applied over the entire or a partial circumference of the container.

In a further development of this concept of the invention, it is provided that the turntable with the container standing thereon, for example by means of a linear motor slidable along the inclined path. Thus, the container only needs to be positioned and aligned once on the turntable.

For this purpose, according to a preferred embodiment of the invention, a centering is provided which fixes the container when lifting immovable in its position. The centering is preferably placed on the container and is held on this by its own weight. This simple design ensures accurate alignment of the container with the printheads throughout the printing process.

According to a further preferred embodiment of the invention, a cover is provided within which the processing stations arranged in the different treatment levels are arranged, wherein the centering with the container is preferably guided and displaceable within the cover along the inclined path. This prevents the wind during rotation of the machine impairs the printing process and the application of the drops of paint on the container.

In order to prevent the ink from curing on the printheads during UV curing, an aperture is provided according to the invention with which the cover can be closed. The bezel is opened for the supply and removal of the containers and closed during the UV treatment, so that the print heads are shielded.

The invention also extends to methods for printing on containers, preferably by means of ink-jet printing, during the rotation of the preferably continuously rotating machine, in particular using the device described above. According to the invention, treatment stations are provided on the rotating machine, which are essentially one above the other the printheads necessary for printing and optionally further facilities required for pre- and post-treatment of the containers in a preferably inclined by about 90 ° to the transport plane of the container web, wherein the containers are guided by moving along the inclined path to different treatment stations.

Preferably, after being guided to one of the treatment stations, the containers remain there for treatment and are moved to the next position only after completion of the treatment. This simplifies the assignment and control of the print heads, since during the printing process only the rotation of the containers induced via the turntable has to be taken into account. There is enough time during the rotation of the rotating machine to complete the treatment of the containers at the various treatment stations.

The position to be approached by the container is given electronically depending on the container design and design of the surface to be printed and is thus individually and flexibly adjustable.

To increase the pixel density of the printing within a plane intermediate positions are approached in the invention. The printing process is then offset a second time in the same plane and, if appropriate, carried out with a modified or correspondingly adapted image.

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and the drawings. All described and / or illustrated features alone or in any combination form the subject matter of the invention, regardless of their combination in the claims or their dependency.

Fig. 1

schematisch eine Draufsicht auf eine Vorrichtung gemäß einer ersten Ausführungsform der Erfindung,

Fig. 2A-2F

schematisch den zu bedruckenden Behälter an verschiedenen Positionen einer Behandlungsstation,

Fig. 3A

schematisch eine Seitenansicht einer Behandlungsstation gemäß einer zweiten Ausführungsform mit in einer Ebene vorgesehenen Druckköpfen,

Fig. 3B

die Behandlungsstation gemäß Fig. 3A von vorne,

Fig. 3C

schematisch eine Draufsicht auf die Behandlungsstation mit geöffneter Blende,

Fig. 3D

schematisch einen Schnitt entlang der Linie D-D in Fig. 3B,

Fig. 4A-C

schematisch die Bearbeitungsfolge in einer Behandlungsstation gemäß Fig. 3,

Fig. 5

schematisch eine Draufsicht auf eine Vorrichtung gemäß einer abgewandelten Ausführungsform.

Show it:

Fig. 1

1 is a schematic plan view of a device according to a first embodiment of the invention;

Fig. 2A-2F

schematically the container to be printed at different positions of a treatment station,

Fig. 3A

1 is a schematic side view of a treatment station according to a second embodiment with in-plane printheads;

Fig. 3B

the treatment station according to Fig. 3A from the front,

Fig. 3C

schematically a plan view of the treatment station with open aperture,

Fig. 3D

schematically a section along the line DD in Fig. 3B .

Fig. 4A-C

schematically the processing sequence in a treatment station according to Fig. 3 .

Fig. 5

schematically a plan view of a device according to a modified embodiment.

In the Fig. 1 illustrated apparatus for printing on containers has a carousel 21, which preferably circulates continuously and are fed via an inlet star 20, the containers to be printed. On one not shown rotational base of the carousel 21 is a plurality of, for example, fifty treatment stations 23 arranged side by side.

The treatment stations 23 rotate at the same speed as the carousel 21. After circulating in the direction of rotation indicated by the arrow R, the containers are removed again from the carousel 21 via an outlet star 22 and supplied for further processing. Of course, it is possible to provide over the circumference of the carousel 21 a plurality of mutually associated inlet and outlet stars 20, 22, as far as between them a sufficient distance for performing all printing and treatment steps is given in the treatment stations 23.

As in Fig. 2 is shown, a container 1, in particular a bottle, arranged in the treatment stations 23 on a turntable 2, which can be rotated via a drive unit 3, in particular a servo motor or a stepping motor. The turntable 2 is with the container thereon 1, for example, via a linear motor 13 along a direction inclined to the transport direction R of the carousel 21, in Fig. 2 shifted by a corresponding arrow indicated path B. Usually, and so also in the illustrated embodiment, this web B is offset by 90 ° to the transport direction R of the carousel 21, so that the container 1 are vertically displaced relative to the rotating in the horizontal direction carousel 21. However, it is within the scope of the invention that the web B is inclined at a different angle to the direction of rotation R of the carousel 21, for example by 45 or 60 °, as long as provided in the individual treatment stations 23, explained in more detail below devices arranged substantially one above the other are.

The container 1 is held on the turntable 2 by means of a centering 10, which fixes the container 1 during lifting immovable in its position. The Centering 10 can be placed on the container 1 and lies on this by its own weight.

The turntable 2 is mounted with its drive unit 3 via a mounting 12 on a transport element, in particular a linear motor 13 and can thus with the arranged on it container 1 vertically moved up and down and the superposed printing and treatment positions are supplied. The drive system provides an electronic feedback to the plant control, so that an exact positioning of the container 1 at the treatment facilities 5 to 9 is allowed. In this case, the position to be approached is determined by the shape of the container 1 and the design of the surface 4 to be printed and predetermined by the system controller. The printed image can be flexibly changed during operation, so that, for example, on each container 1 another image can be printed.

In the vertical movement of the container 1 is automatically centered on the turntable 2 via the centering 10, wherein the centering 10 rests solely by its own weight on the container 1. The vertical movement of the container 1 and arranged on it centering 10 is guided over a longitudinal guide, not shown, within a trained example as a protective cover 14. The driven by the rotating container 1 with rotatable centering 10 is connected via a pivot bearing 11 with the longitudinal guide, not shown. The cover 14 protects the printing process against the wind generated during the rotation of the carousel 21, and is open in the area of the container change, so that the container 1 can be easily inserted into the treatment station 23 and removed therefrom.

After the transfer of the container 1 from the inlet star 20 in the in Fig. 2A shown container change position A, the container 1 is first by means of the linear motor 13 vertically to a position B ( Fig. 2B ), in which By means of one or more plasma torches (s) 5 an activation and cleaning of the container surface takes place in the area 4 to be printed. The container 1 is in this case rotated by means of the turntable 2 at least once about its axis, so that the entire circumference of the container 1 can be treated. The position of the plasma torch 5 depends on the container shape and the image to be printed and is electronically adjusted by suitable software based on the image information.

After surface treatment in position B, the container 1 is moved to position D (FIG. Fig. 2D ), in which, again during at least one rotation of the container 1, one or two colors are applied via corresponding inkjet printheads 7.

Subsequently, the container 2 is moved to the position C (FIG. Fig. 2C ) is lowered, in which by means of a UV treatment 6 or other suitable auxiliary energy hardening and crosslinking of the printing inks or pinning (partial drying of the ink) is achieved.

If printing with other colors is desired, the container 1 is moved to the position E (if required). Fig. 2E ), in which by means of the print heads 8 more colors are applied to the printing area 4. After printing, in turn curing or pinning of the printing inks takes place by UV irradiation at position C in the device 6. If further colors are required, the container 1 is then moved by means of the linear motor 13 into the position F (FIG. Fig. 2F ) method, in which 9 further colors are applied by means of printheads. Subsequently, a UV curing takes place again in the device 6.

The arranged in the protective cover 14 printhead stations 7, 8 and 9 are each a in Fig. 3 closer aperture 15, in particular a sliding panel, sealed, which opens during the movement of the turntable 2 in the corresponding printing position. This prevents accidental curing of the ink on the printheads 7-9 by the UV irradiation, since in the activation of the UV treatment 6 at position C, all printheads 7-9 are shielded.

By a slight displacement of the turntable 2 by means of the linear motor 13 and re-printing by means of the print heads 7, the pixel density can be selectively increased at the positions D, E and / or F.

From the above description it follows that adjacent stations do not necessarily have to be approached in succession and not all treatment stations. Rather, the order can be specified by the system control as needed.

The order of arrangement of the individual levels can also vary in order to achieve the shortest possible sum of the travel paths or to obtain better accessibility to components.

Finally, the turntable 2 is returned to the container 1 again in the container exchange position A and can be removed after a round about the carousel 21 via the outlet star 22 from the machine.

When lowering the container 1 in the container exchange position A, the container 1 is automatically released from the centering 10 and can be removed through the outlet star 22. The container exchange position A is in the same plane for the inlet and the outlet.

In Fig. 3 the construction of a printing station is shown in more detail, wherein a plurality of print heads 7a, 7b, 7c are arranged in a plane. Same as above described an arrangement in several, substantially superimposed planes possible.

The printing station is held on guide rods 16, which also the vertical displacement of the turntable 2 and arranged thereon, in Fig. 3 lead container 1, not shown. In the illustrated embodiment, the centering 10 with a above the printing station arranged weight 17, which is connected to the pivot bearing 11 via a rod 18, weighted. The protective cover 14 has at its lower end in particular designed as a sliding panel aperture 15, with which the protective cover 14 can be closed. During rotation, the protective cover 14 provides protection against drafts and serves as a housing for the extraction of aerosols. At the same time, the printheads 7a, 7b, 7c are protected from the UV radiation when the curing takes place in the UV irradiation unit 6.

In the embodiment according to Fig. 3 For example, the UV radiator 19 of the UV irradiation unit 6 and the plasma torch 5 are arranged in one plane. Again, as described above, an arrangement in several levels is possible.

Fig. 4 schematically shows the processing sequence when using a treatment station, as in Fig. 3 is shown.

First, with lowered turntable 2, the container 1 (bottle) is inserted and sucked by means of negative pressure on the turntable 2 ( Fig. 4A ). The container 1 is first lifted into the centering and then rotates with the turntable 2 and is pretreated with plasma. Subsequently, the turntable 2 is raised with the container 1 in the protective cover 14, rotated there and printed by means of the print heads 7a, 7b, 7c ( Fig. 4B ). Here, the slide shutter 15 is open. Subsequently, the turntable 2 is lowered and the aperture 15 is closed ( Fig. 4C ). The container 1 is rotated and the color is cured by means of the UV radiator 19 or subjected to pinning when applying further colors. The operation open aperture, lift container (either in the same level as before or in another level not shown), further printing, lowering to UV level would then repeat as often as programmed. Finally, after the last UV treatment, the container 1 is lowered to the discharge level, removed and the shutter 15 is opened for the next cycle.

At the in Fig. 5 illustrated, modified embodiment, the UV lamps 19 are provided in one or more fixed, not co-rotating UV irradiation unit (s) 6 on the circumference of the carousel 21. Also in this variant, the diaphragms 15 are provided at the printing stations to prevent hardening of the ink at the nozzles of the print heads.

LIST OF REFERENCE NUMBERS

1

container

2

turntable

3

drive unit

4

pressure range

5

plasma torch

6

UV irradiation unit

7

printhead

7a, 7b, 7c

printheads

8th

printhead

9

printhead

10

centering

11

pivot bearing

12

attachment

13

linear motor

14

protective cover

15

cover

16

guide rods

17

Weight

18

pole

19

UV lamps

20

feed star

21

carousel

22

outlet star

23

treatment station

R

Direction of rotation of the device

B

Path of the treatment unit

Claims (14)

1. A device for printing containers (1), preferably by means of inkjet printing, on a rotation machine with treatment stations (23), which comprise the printing heads (7-9) necessary for printing the containers (1), characterized in that the printing heads (7-9) and if required further devices (5, 6) required for pre-treatment and post-treatment of the containers (1) are arranged substantially on top of one another in a path (B) that is inclined preferably by approximately 90 degrees to the transport plane of the containers (1), and in that the machine comprises transport elements for displacing the containers (1) along the inclined path (B).
2. The device according to Claim 1, characterized in that the treatment stations (23) in the different planes comprise printing heads (7-9), devices (6) for cross-linking the ink by means of auxiliary energy and/or a plasma burner (5) or the like for the surface pre-treatment prior to the printing.
3. The device according to Claim 1 or 2, characterized in that the inlet and outlet of the treatment stations (23) are located in one plane.
4. The device according to any one of the preceding claims, characterized by a turntable (2) provided with a drive unit (3), in particular a servomotor or a stepping motor, for receiving the containers (1) and their rotation within the treatment stations (23).
5. The device according to Claim 4, characterized in that the turntable (2) with the containers (3) standing thereon can be displaced for example by means of a linear motor (13) along the inclined path (B).
6. The device according to any one of the preceding claims, characterized by a centering device (10) which fixes the container (1) in its position during lifting.
7. The device according to Claim 6, characterized in that the centering device (10) can be fitted onto the container (1) and fixes the latter in its position through its own weight and/or an additional weight (17).
8. The device according to any one of the preceding claims, characterized by a covering (14), which covers the treatment stations (23) arranged in the different treatment planes.
9. The device according to Claim 8, characterized by a screen (15) with which the covering (14) can be closed off.
10. The device according to any one of the Claims 6 to 9, characterized in that the centering device (10) with the container (1) can be displaced within the covering (14) along the inclined path (B).
11. A method for printing containers, preferably by means of inkjet printing, during the rotation of a preferably continuously running rotating machine, characterized in that on the rotating machine treatment stations are arranged, which substantially on top of one another comprise the printing heads necessary for printing and if required further devices required for the pre-treatment and post-treatment of the containers in a path that is inclined to the transport plane of the containers preferably by approximately 90 degrees and in that the containers are guided to different treatment stations through displacing along the inclined path.
12. The method according to Claim 11, characterized in that the containers after they were guided to one of the treatment stations, remain there for the treatment and are moved into the next position only after completion of the treatment.
13. The method according to Claim 11 or 12, characterized in that the position to be accessed is electronically predetermined depending on container design and design of the area to be printed.
14. The method according to any one of the Claims 11 to 13, characterized in that for increasing the pixel density of the printing, intermediate positions are accessed within a plane and the printing process carried out in the same plane a second time offset with changed or suitably adapted image if required.

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