EP2572887B1 - Container printing assembly - Google Patents

Description

The invention relates to a container printing system for applying a color print on containers, such as bottles, with a container conveyor, which is arranged so that a guided in the container conveyor container on a transfer drum of the container printing system with at least one attached to the circumference of the transfer drum transfer element can be brought into contact wherein at least one print head is provided for applying a negative image to the transfer element, wherein furthermore the transfer drum is rotatably mounted about a transfer drum rotation axis and the transfer element has a convexly shaped transfer element surface facing the container.

Various devices for printing bottles or similar containers on a container outer surface are known from the prior art.

For example, the WO 2009/052890 A1 a device for printing on bottles or similar containers on a container outer surface with at least one printing station at its printing area the containers are moved past a container conveyor, with at least one print head and with at least one transfer surface forming and provided on an auxiliary conveyor transfer element.

Among other things, the printing station comprises a transfer drum driven about its vertical axis in a specific direction, at the circular cylindrical peripheral surface thereof, offset at equal angular intervals around the drum axis, a plurality of transfer elements, d. H. in a corresponding embodiment, a total of three transfer elements, preferably interchangeable provided. Each transfer element is multi-layered, d. H. it consists, inter alia, of an adhesive layer external to the axis of the transfer drum, of a material suitable for transfer printing, of a rubber-elastic intermediate layer following the adhesive layer, for example a harder rubber or an elastomeric plastic and of a carrier layer adjoining the intermediate layer a metallic material or plastic, with which the respective transfer element is attached to the circumference of the transfer drum. Each transfer element, with its outer or transfer surface formed by the adhesive layer, is curved in the shape of a circle around an axis of the transfer star in the shape of a crescent, where it is elastically deformable like a pillow but wrinkle-free.

Also, other devices, for example from the WO 2004/009360 A1 , of the GB 2376920 A , of the US 6,684,770 B2 , of the US 2003/0121428 A1 , of the US 7,011,728 B2 , of the US 2003/0015105 A1 , of the US 6,920,822 B2 and the US 2005/0045053 A1 known.

A device according to the preamble of claim 1 is known from DE 10 2007 050 490 A1 known.

Although the known devices allow a printing of containers with relatively high quality, d. H. with a high-quality, in particular also sharp and distortion-free and / or defect-free imprint, but only if the containers to be printed have the smallest possible dimensional tolerances and have no or possibly no unevenness at their area to be printed.

However, it is the object of the invention to provide a device that allows bottles or similar containers at high power, d. H. many containers per unit of time to print with high quality. The inventive construction should make it possible to print even those bottles or similar containers that have relatively large dimensional tolerances and / or unevenness, with high quality and high performance directly on the container outer surface.

This object is achieved in that the transfer element is rotatably mounted about a spaced apart from the transfer drum rotation axis pivot axis. In this way, an eccentric storage can be realized. Each transfer element is then mounted on its outer or transfer surface eccentrically to the transfer drum rotation axis and curved around the pivot axis.

In this way, it is possible to print a particularly large number of containers per time unit and at the same time achieve a very good quality. Virtually no lubricating or distorting effects are recognizable.

Since the transfer element surface follows the shape of a circular arc around a circle center spaced apart from the transfer drum rotation axis, the efficiency is improved.

Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

Thus, it is advantageous if the transfer element surface has a greater curvature than the transfer drum surface. In this way, the transfer elements attach particularly well to the surface of the container, for example the bottles. The quality can be improved.

It is also expedient if the transfer element has a carrier layer constructed of plastic or metal, which is covered on the container side by a rubber-elastic intermediate layer, which in turn is prepared by one for receiving the negative image Adhesive layer is covered. The color application quality on the printed container can then be improved.

If several transfer elements are distributed at equal angular intervals on the circumference of the circular cylindrical peripheral surface of the transfer drum, then the throughput of containers to be printed per unit time can be further increased. Also, the transfer elements can be printed differently, so that multi-color prints are feasible.

An advantageous embodiment is also characterized in that each of the transfer elements without slip on each a single container is fed past. Blurring can be avoided.

If a side of the transfer element facing each container is pillow-like elastic but wrinkle-free deformable, a particularly good print quality is achieved.

It would also be conceivable that the surface of the transfer elements is such that, similar to a stamp, color-transferring areas are raised than non-color-transferring areas. The ink could thus be transferred to the raised areas of the transfer elements via inking rollers and finally transferred from the transfer elements to the bottles in the manner described above, similar to the high-pressure method. In particular, only one color is assigned to a transfer element in the case. In that case, the printhead is an inking roller.

It is also advantageous if multiple printheads are provided, which are designed for the simultaneous or sequential application of liquid, such as paint or paint, to a particular transfer element. As a result, particularly high-quality prints, in particular multi-color prints and prints protected with lacquer, can be achieved. It is also advantageous if one or more aftertreatment stations are present, in particular those which by energy input and / or -eintrag, for example by infrared radiation, UV radiation, microwave energy, hot air or the like, drying, setting and / or baking of the print image applied directly to the container.

It is advantageous if the container is mounted in the container conveyor such that the containers, in particular bottles, can be printed around their axis of rotation during the rotation of the container.

The invention also relates to a bottle filling device with a container printing system, as explained above.

Fig. 1

einen schematischen Aufbau einer Behälterbedruckungsanlage,

Fig. 2

die Behälterbedruckungsanlage aus Fig. 1 im in einer Flaschenbefüllvorrichtung eingebundenen Zustand mit einer Vielzahl an Nachbehandlungsstationen, wobei mehrere Behälterbedruckungsanlagen eingesetzt sind,

Fig. 3

der Beginn des Aufbringens einer Bedruckung auf einen Behälter in denen in Fig. 1 und 2 dargestellten Behälterbedruckungsanlagen,

Fig. 4

eine Darstellung des Aufbringens der Bedruckung auf dem Behälter im letztmöglichen Bedruckungszeitpunkt,

Fig. 5

eine Ansicht von oben auf ein Transferelement und

Fig. 6

einen Querschnitt durch das Transferelement aus Fig. 5 entlang der Linie VI, wie es in der in den Fig. 1 bis 4 dargestellten Behälterbedruckungsanlage eingesetzt ist.

A container printing system according to the invention and a transfer device contained therein is explained in the following drawing. Show it:

Fig. 1

a schematic structure of a container printing system,

Fig. 2

the container printing system off Fig. 1 in the state enclosed in a bottle filling device with a plurality of aftertreatment stations, wherein a plurality of container printing systems are used,

Fig. 3

the beginning of applying a print to a container in which Fig. 1 and 2 illustrated container printing systems,

Fig. 4

a representation of the application of the printing on the container in the last possible printing time,

Fig. 5

a top view of a transfer element and

Fig. 6

a cross section through the transfer element Fig. 5 along the line VI, as in the in the Fig. 1 to 4 shown container printing system is used.

The figures are merely schematic in nature and are only for the understanding of the invention. The same elements are provided with the same reference numerals.

In Fig. 1 a first container printing system 1 according to the invention is shown. The container printing system is provided for applying a color print to a container 2. The container 2 is formed as a bottle. The container 2 can also be designed as a can or cup.

With a container conveyor, the in Fig. 2 is visualized and provided there with the reference numeral 3, container 2 of the container printing system 1 are supplied. The container conveyor 3 may be designed as a star conveyor and also use endless conveyor.

The container printing system 1 also has a transfer drum 4. The transfer drum 4 has a circular cross section. The transfer drum 4 has a circular cylindrical peripheral surface 5. On the transfer drum 4 and transfer elements 6 are attached. The transfer elements 6 are shown in their initial position, wherein a transfer element 6 is shown in its end position 7, ie after the transfer of a paint or varnish layer 8 to a container surface 9 of the container 2.

Four paint applicators 10 are provided, each having a printhead 11. About the print head 11 color and / or paint can be spent on a transfer element surface 12.

On the transfer element surface 12, a negative image is applied by means of one or more print heads 11.

The transfer drum 4 is rotatably mounted about a transfer drum rotation axis 13.

Each transfer element 6 has a transfer element surface 12 facing the respective container 2 to be printed, which is convexly shaped.

The transfer element surface 12 follows the shape of a circular arc 14. The circular arc 14 is in Fig. 1 to recognize well in a representation from above. The circular arc 14 is part of a circle, not shown, about a circle center, wherein the circle center is located in a pivot axis 15, and wherein the pivot axis 15 is the axis about which the transfer elements 6 are each rotatably mounted. In other words, each transfer element 6 is connected pivotably or rotatably about its own pivoting drum 4 about its own pivot axis 15.

The transfer elements 6 are individually or jointly drivable.

In Fig. 2 the conveying and conveying away of the container 2 is shown by means of a container conveyor 3, which has a buffer device 16. There are a plurality of aftertreatment stations 17, which are arranged adjacent to each of a container printing system 1 according to the invention.

The conveying direction is indicated by an arrow 18. The direction of rotation of the transfer drum 4 is indicated by an arrow 19.

It should be noted that it is conceivable to detect a container contour, an embossing, an emblem or a mark via a camera 23 before the printing process. The required correction rotation of the container, ie the container 2 for the subsequent printing process, via a corresponding turntable control and the SERVO motor on a bottle table. This can be called pre-alignment. During the pre-alignment, the pressure seam on the container side wall, which is of particular value in the case of glass and PET bottles, can also be recognized and accordingly adapted / taken into account in the subsequent printing process. The print image position can also be adjusted / taken into account.

In the FIGS. 3 and 4 the slip-free rolling of the transfer element surface 12 of the transfer elements 6 is shown.

While in Fig. 3 the initial state of the transfer elements 6 when applying the paint or varnish to the container 2 is shown in FIG Fig. 4 the end position 7 of the transfer element 6 after the application of the paint or varnish layer 8 to the container 2 is shown.

In the FIGS. 5 and 6 the transfer element 6 is shown in a singular representation from above. As can be seen there as well, the transfer element 6 has at least three layers. Namely, one of the pivot axis 5 nearest plastic or metal constructed carrier layer 20, a rubber elastic intermediate layer 21 and an outer adhesive layer 22nd

The container printing system 1 includes, among other things, a transfer star driven about its vertical axis in the direction of the arrow 19, which is also referred to as a transfer drum 4. Offset at uniform angular intervals about the transfer drum rotation axis 13, a plurality of transfer elements 6, preferably six or eight replaceable transfer elements 6 are provided. Each transfer element 6 is, as already explained, formed in multiple layers. On the outer adhesive layer 14, a transfer printing can be applied. The intermediate layer 21 is constructed of a harder rubber or an elastomeric plastic.

The printheads 11, which are part of a printing station, are not arranged co-rotating. Through them is the complete, applied to a bottle print image in a negative or mirror image form, d. H. as a negative print image or negative image, applied to the transfer surface 12 serving as a transfer surface. The transfer elements 6 can also be referred to as pallets, in particular as transfer pallets. They move past the print head 11. The printhead 11 is preferably an electronic printhead 11 and comprises for multicolor printing a plurality of electronically controllable individual printheads, which are provided in succession in the direction of rotation 19, for example a single printhead for black and a plurality of individual printheads for different color sets of a multicolor print.

The individual print heads are preferably those which are known as "drop on demand" and which each have a plurality of nozzle openings in a row which are parallel or substantially parallel to the axis about which the transfer elements 6 pivot, ie the pivot axis 15. are oriented. Each nozzle opening is associated with an electrode. The individual print heads or their electrodes are driven by a print image electronically generating control device, in such a way that at the nozzle openings when a change in the potential of the associated electrode with respect to the potential of the nozzle opening ink is applied to the formation of a pixel on the transfer element surface 12 of the transfer elements 6. Alternatively, in a simple case, a screen printing unit such as a rotary screen printing unit is used. Further, it is conceivable that instead of a printhead 11 up to four printheads 11 are mounted in order to be able to print a four-color print or the print motif divided into four zones.

Furthermore, it is conceivable that a printhead 11 in the direction of rotation at the periphery of the transfer axis and not co-rotating with a cleaning station or cleaning position is provided at the moving past the pivot axis 15 of the transfer elements 6 pallets before applying the new negative-image print image on her Transfer element surface 12 cleaned, d. H. be freed of existing residual and printing ink. The cleaning station is formed in the simplest case of one or more scrapers.

Each provided in the negative pressure image on the transfer element surface 12 transfer element 6 passes with the rotating transfer drum 4 to a printing area, if there is a standing on a bottle table, d. H. with its axis oriented in the vertical direction bottle, is moved past.

The container conveyor 3, which is also referred to as a container conveyor is in the illustrated embodiment, a synchronous about a vertical machine axis with the transfer drum 4 rotatably driven turntable or rotor with a plurality of plate-shaped container carriers, offset at equal angular intervals about the vertical machine axis of the rotor its circumference are provided and controlled about its vertical axis via a motor, such as a SERVO motor, are rotatable. With the respective container carrier an upper end is exactly fixed by an unillustrated element, for example by a centering bell, as well as a lower area by a bottle plate with centering.

The thus fixed bottle is rotated in the printing area about its axis, in such a way that this bottle with the area to be printed, for example, the bottle side wall, without slip on the passing transfer element 6 and the local transfer element surface 12 rolls and thus the negative print image of the respective transfer element 6 is applied as a positive pressure to the relevant bottle.

Each bottle printed in this way will continue with the associated container carrier, for example, in the bottle plate or bottle table, standing up with the container conveyor moves and passes inter alia to a station, which is referred to as aftertreatment station 17. There is achieved by energy or energy input, for example by infrared radiation, UV radiation, microwave energy, hot air or the like, a drying, setting and / or baking of the applied directly to the bottle print image, preferably while continuing to the bottle axis with the Container turntable turned bottle.

A special feature of the printing station is that on each transfer surface or each transfer element 6 when moving past the print head in each case in negative form, the complete, applied to the bottles print image is generated. In order to achieve a high-quality, especially clean, Verdragstellenfreies and sharp print image, while it is necessary that a precisely prescribed distance between the transfer surface and the print head or the individual print heads is complied with, this is easily possible with the present invention.

Furthermore, at least one or more printing stations can be applied circumferentially distributed from the bottle table, either to increase the performance or to increase the number of colors and / or to apply a protective coating.

Furthermore, it is conceivable to perform a pretreatment by corona or similar radiation before the first printing unit at the bottle table or in the machine inlet. Likewise, after the last printing station, the quality of the printed image can be checked via a camera device with subsequent removal of incorrectly produced objects, and defective printed containers 2 can be eliminated.

By the elastic intermediate layer 21 ensures that even with dimensional tolerances, eg. B. tolerances in the diameter of the bottles, these tolerances may well be in the range between 0.5 to 0.7 mm, but also in the case of bumps the required for the transfer of the printed image from the transfer element 6 to the respective bottle dense concerns the transfer surface the bottle area to be printed is guaranteed.

Overall, therefore, the appropriate arrangement of the printing stations has the advantage that a high-quality printing in compliance with the necessary very critical distance between the print head 11 and the transfer surfaces is possible, despite considerable dimensional tolerances of the bottles, these tolerances u.a. by the elastic formation of the transfer elements, d. H. in the elastic intermediate layers, be compensated.

Claims (8)

1. Container printing unit (1) for applying a colour print to containers (2), such as bottles, having a container conveying device (3) which is arranged in such a way that a container (2) conveyed in the container conveying device (3) can be brought into contact at a transfer drum (4) of the container printing unit (1) with at least one transfer element (6) attached to the periphery of the transfer drum (4), wherein there is at least one print head (11) for applying a negative image to the transfer element (6), wherein in addition the transfer drum (4) is pivot-mounted about a transfer drum rotational axis (13) and the transfer element (6) has a convex transfer element surface (12) facing the container (2), wherein the transfer element (6) is movably attached to the transfer drum (4), and wherein the transfer element surface (12) follows the shape of an arc of a circle (14) about a centre of a circle spaced apart from the transfer drum rotational axis (13), characterised in that the transfer element (6) is pivot-mounted about a pivot axis (15) spaced apart from the transfer drum rotational axis (13).
2. Container printing unit (1) according to Claim 1, characterised in that the transfer element surface (12) has a greater curvature than the transfer drum surface.
3. Container printing unit (1) according to either of Claims 1 and 2, characterised in that the transfer element (6) has a base layer (20) composed of plastic or metal and the container side is covered by a rubbery-elastic intermediate layer (21) which itself is covered by an adhesive layer (22) prepared to receive the negative image.
4. Container printing unit (1) according to any one of Claims 1 to 3, characterised in that a plurality of transfer elements (6) are distributed at uniform angular distances on the periphery of the circular cylindrical peripheral surface (5) of the transfer drum (4).
5. Container printing unit (1) according to any one of Claims 1 to 4, characterised in that each of the transfer elements (6) can be conveyed past each individual container (2) slip-free.
6. Container printing unit (1) according to any one of Claims 1 to 5, characterised in that one side of the transfer element (6) facing the container (2) can be flexibly deformed like a cushion but free from creases.
7. Container printing unit (1) according to any one of Claims 1 to 6, characterised in that there are a plurality of print heads (11) which are designed to apply liquid, such as paint or lacquer, to a particular transfer element (6) simultaneously or sequentially and/or there is/are one or more post-treatment stations (17).
8. Bottle filling apparatus having a container printing unit (1) according to any one of the preceding claims.

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