EP2661374A1 - Machine for printing on containers - Google Patents

Abstract

The invention relates to a machine (1) for printing on containers, such as bottles or cans, comprising a plurality of treatment stations (7), on which printing heads (12) and possibly additional devices required for pre- and post-treating the containers (1) are provided, and comprising a carrier (3) for a plurality of containers (2), which are arranged next to each other on the carrier (3). The carrier (3) can be transported from one treatment station (7) to the next by means of a conveyor belt (6), a plurality of treatment stations (7) are arranged substantially transversely to the conveyor belt and next to each other in a row, the carrier (3) is arranged substantially transversely to the conveyor belt (6), and the treatment stations (7) and the carrier (3) can be moved relative to each other in a substantially vertical direction. A rotating device can also be provided instead of the conveyor belt (6).

Description

 Machine for printing on containers

The invention relates to a machine for printing on containers, such as bottles made of glass or plastic or cans, with a plurality of treatment stations, on which printheads and possibly further required for pre- and post-treatment of the container facilities are provided, and with a carrier for several Containers placed side by side on the carrier.

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 inkjet printers to allow for customizations that label printing does not allow. Such printing systems work monochrome and are limited to a few printing dots per line.

In order to apply a multicolor print directly to containers, a plurality of single-color printheads operating according to the ink-jet principle are successively and correspondingly offset so 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 practical for absorbent packaging materials, for other materials such as metals, glass or plastic, the ink must either be dried by heat or cured by UV or electron beams by cross-linking. the. This process is also to be applied at least as a so-called pinning, a "partial hardening", between the printing of successive printing inks, which increases the length of such machines In the device described in DE 10 2008 049 241 A1 for applying a multicolored print image to a container Several modules are connected in series, in which various treatment steps are carried out, such as pretreatment, printing, drying and checking.The containers are transferred from one module to the next, so that each one new positioning and adjustment is required.This affects the accuracy of the printed image and reduces the throughput speed.

WO 2004/009360 A1 discloses a device 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 industrial use of these plants 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 print head are transported on a rotating machine at a speed of approx. 1.5 m / s so that the drops of paint are exposed to an air flow which can impair the print quality. Object of the present invention is therefore to increase the printing quality in the printing of containers at high printing performance and reliable function. This object is achieved in a machine of the type mentioned above with the invention essentially in that the carrier is transportable via a conveyor belt from one treatment station to the next, that in each case a plurality of treatment stations are arranged substantially transversely to the conveyor belt in series next to each other, that the carrier is arranged substantially transversely to the conveyor belt and that the treatment stations and the carrier in a substantially vertical direction are movable relative to each other.

The machine according to the invention operates in the longitudinal stroke and always handles several containers simultaneously. Since the containers and the print heads do not rotate around the machine during printing on a longitudinal machine, unlike in the case of the above-described rotary travelers, the traveling wind impairing the print quality is eliminated, so that a more exact print image can be achieved.

In an alternative embodiment, the machine operates as a rotary-stroke, wherein the carrier is transportable via a rotating device from one treatment station to the next, wherein it rotates about a center of rotation. Several treatment stations are each arranged substantially radially to the center of rotation in a row next to each other. Also, the carrier is arranged substantially radially to the rotating device. The treatment stations and the carrier are movable in a substantially vertical direction relative to each other.

Both variants thus operate on the same principle, in which a plurality of containers are arranged side by side on the carrier and transported in groups from one treatment station to the next. In a preferred embodiment, the cross member can be lifted up from the conveyor belt, so that the stored on the cross member container are moved from below into the treatment stations. According to the invention, a plurality of, in particular 4 to 7, printheads are arranged in a ring around the container in a treatment station and are preferably arranged in an annular manner aligned with one another on a holding plate. This allows a quick change of print heads with a new plate and the adjustment of the print heads to each other on the plate can be made independently of the machine on a test stand. The maintenance times of the machine can be correspondingly reduced.

According to one embodiment of the invention, turntables for receiving the containers are provided on the carrier, so that the containers can be rotated about the center of the annularly provided around them printheads. The printheads themselves are silent when printing, which further increases the print quality.

So that the containers do not fall over during transport, they are preferably held by negative pressure on the turntables. Alternatively, a jamming is possible, but for example, in PET bottles because of the required pressure can lead to undesirable deformations.

An exact positioning of the container is inventively achieved by a preferably rotatable centering, which is placed on the container and this holds by its own weight.

In a further development of this inventive concept, centering arrangements with rotary drives assigned to the containers are provided at the treatment stations above the carrier, which rotary drives are provided when lifting the carrier by means of rotary drives arranged containers are raised along its longitudinal axis. Due to the overlying weight, the rotation of the drive is reliably transmitted to the container, so that its circumference can be defined guided past the printheads.

After printing, the ink is usually cured by UV rays or electron beam guns (e-beam). When using electron beam guns, cheaper ink can be used because of better cross-linking. However, this z. B. generated X-rays, which may not be released to the environment. According to the invention, for example, a lead-insulated cover which is generally closed and only open at the bottom is provided at the treatment station provided for the aftertreatment, which cover can be closed by lifting the support either by the support itself or by the turntables. If the cross member is lifted with the containers, the box is sealed tightly from below, so that the UV or e-beam treatment can be performed without unwanted radiation escaping.

In order to ensure a defined positioning during printing, according to the invention the cross member is centered alternatively and / or in addition to being pressed by the lifting cylinder relative to the treatment station and / or additionally mechanically clamped. This can be done in a particularly simple manner by means of a Exzenterklemme, but also pneumatically, hydraulically or magnetically. Due to the tension of the cross member, all containers arranged thereon are simultaneously positioned in their respective treatment stations.

The capacity of the machine can be further increased by placing several, in particular two to four, rows of similar treatment stations behind it. are arranged one another and the timing of the machine moves the cross member respectively by two to four steps accordingly.

In order to further reduce vibration during printing, the treatment stations can be attached to the ground separately from the transport system according to the invention. Thus, the transport movements when inserting new containers and removing the finished printed containers are not transferred to the treatment station printing. According to the invention, the processing stations for preparing the printing, the printing process and the color curing can then be followed by stations for filling and closing the containers within the same machine. Thus, the existing container receptacle, the centering of the container, the transport device, the supply and delivery is not necessary a second time and achieved a low-cost system with multiple benefits.

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. Show it:

1 shows schematically a side view of a machine according to the invention according to a first, working in the longitudinal stroke embodiment, 2 shows schematically a plan view of the longitudinal machine with only partially illustrated cross members,

Fig. 3A

and FIG. 3B schematically shows a partial section through the machine with the support lowered or raised,

4 schematically shows a perspective view of a machine according to the invention according to a second embodiment operating in a rotary cycle,

In the longitudinal machine 1 shown schematically in FIGS. 1 and 2 for printing on containers 2, such as bottles made of glass or plastic, cans or the like., Several, shown here in bottle form container 2 on a designed as a transport beam carrier (cross member). 3 arranged side by side in series and treated in parallel.

Each cross member 3 has a defined number, preferably eight or twelve, each rotatable about an axis turntable 4. The container 2 are held on the turntables 4 by negative pressure. For this purpose, 4 not shown suction holes are provided in the turntables, is sucked by the. Preferably, the vacuum extraction takes place centrally, for example by a vacuum channel 15 along one or both sides of the machine. 1 The vacuum channel 15 has guides 16, in which lateral end plates 17 of the cross member 3 slide to avoid additional tubes during longitudinal transport as well as the lifting movement. The vacuum channels 15 are sealed to the lateral end plates 17 of the cross member 3 as well as the turntable 4, for example. About brush strips or seals. During the lifting movement run over and under the end plates 17 slide 18, which close the gaps resulting from the stroke. The stability of the container 2 on the turntables 4 can da- be further improved by the turntable 4 are adapted by means of interchangeable format parts 10 of the bottom contour of the bottle. When placing the container 2 on the turntable 4, the turntable 4 is then preferably rotated with low torque, so that the container contour can engage in the negative mold of the format part 10 on the turntable 4 and thereby z. B. the rotation stops.

The cross members 3 are transported by the machine 1 to the individual treatment stations 7 via a conveyor belt 6, in which the cross members 3 engage via centering pins 19 or the like. The conveyor belt 6 is moved in cycles. This can be at a first station z. B. eight containers 2 are pushed onto the individual turntable 4 and fixed by the negative pressure from the lateral vacuum channels 15. The cross member 3 are moved with their fixed containers 2 by the conveyor belt 6 intermittently. They thus arrive at a first treatment station 7, in which the cross member 3 with all centered and thus fixed containers 2 is lifted off the conveyor belt 6. The lifting of the cross member 3 via pneumatic cylinder 8. Alternatively, the cross member 3 remain on the conveyor belt 6 and the treatment stations 7 are lowered accordingly and then lifted again.

Above the turntable 4 7 centering 5 are provided at the treatment stations, so that the container 2 align its axis perpendicular. These centers are driven by rotary drives or motors 9, for example servomotors or stepper motors, and transmit the rotational movement via the centering 5 to the containers 2. In this case, use is made of the containers 2 lifting the centering 5 and the motors 9 by the lifting movement and whose own weight generates the necessary friction or positive locking in order to to transfer agile torque. If necessary, the weight is supported by another force

The cross members 3 are preferably fixed in their upper position by a plurality of electromagnets or mechanical locks, for example. An eccentric clamp, to prevent vibrations and possible bending. In this case, alternatively, the Behälterzentrierungen 5 can be lifted at its top in a coupling, not shown, which is connected to a rotary drive 9 per station.

In the machine 1, the cross member 3 with the containers 2 are first transported to a pretreatment station 7a and treated after lifting in the station by a plasma jet on its surface to be printed to z. As grease or activate the surface. The containers can be centered in this station by the centering 5 and rotated.

After the plasma treatment, the containers 2 are lowered together with the cross member 3 in the cross beam centering on the conveyor belt 6 and further transported to the printing station 7b. There, the cross member 3 are raised again with the containers 2 and thereby in the Behälterzentrierungen 5, which is connected in each case one designed as a servomotor or stepper motor rotary drive or motor 9 out. The containers 2 are now rotated and the pressure begins, as soon as a constant speed is reached, preferably at all print heads 12 of a station 7b simultaneously. Each container 2 is printed in its own printing station 7b, the print heads 12 of which are arranged in a circle on a holding plate 13 on a diameter which corresponds to the maximum diameter of the container 2 plus a predefined distance (see FIG. For non-cylindrical containers 2, the arrangement of the print heads 12 of the contour of the container 2 is adjusted. The container 2 is fed below the holding plate 13 of the print heads 12 and through a simple lifting device 8 raised so far that the container 2 is positioned with its surface to be printed in the ring of the print heads 12. If you want to have a wider print area than the printhead width, the hub is instead of pneumatic cylinder 8 by a servo axis, which is able to bring the container so in a second stroke position that a continuation of the pressure can be done without a hitch. The holding plates 13 with the print heads 12 are designed to be removable in their fixation down, without the orientation of the heads 12 is lost among themselves. Thus, the printheads 12 can be changed quickly by attaching a new support plate 13, wherein the setting of the annular printheads 12 can be made with each other on the support plate 13 independently of the machine 1 on a test stand, not shown.

After the end of the rotation (at a simple pressure after a rotation, at a higher resolution pressure after two rotations, then an offset is generated after the first rotation so that the subsequent pressure points can be applied between the pressure points of the first rotation), the cross beams become 3 lowered again with the containers 2 and further transported to the next (post-treatment) station 7c. There, they are raised again and put back by coupling the container centering to a respective rotary drive 9 in rotation. In this case, the container 2 moves this time in a well-closed and only downwardly open cover 14. The cover can be performed either individually per station or as a box over about the length and width of the carrier. The downward opening is sealed either by the turntable 4 or the carrier 3 by the turntable 4 or the carrier 3 at the end of the lifting operation there rests or drives in a labyrinth seal. At this station 7c, the ink is cured by means of UV rays 20 or electron beams (e-beam) 20, or partially cured (pinning), if other colors to be printed follow. Thus, no rays can escape through the formation of the cover 14 and a Safe container handling for the environment. Alternatively, a common drive for rotation can be installed at this station for all containers, the z. B. via a friction belt all Behälterzentrierungen 5 drives. After the end of the curing process, the carrier 3 with the containers 2 is lowered again and moved to the last station, the discharge station, from which it leaves the system.

The empty cross member 3 are guided in a rail 1 1 driven over the return strand of the transport device back to the beginning. Due to the leadership in the rail 1 1, the cross member 3 can not fall out of its centering.

The treatment stations 7 are preferably staggered on the ground, separate from the transport device 6, in order to avoid that vibrations caused by mechanical processes other than the printing itself are transmitted to the printheads 12.

The invention ensures in a simple manner an optimal print image without being influenced by tolerances. For this purpose, the pressure with z. B. up to seven colors in a single station 7b and performed in a single position at a time to which no mechanical transports or movements other than the container rotation take place and thus the pressure takes place in complete peace. Partial curing (pinning) can also take place in this position.

In an alternative embodiment, two to four rows of the respective carrier 3 are arranged one behind the other and the conveyor belt 6 in Doppelbzw. Driven three or four steps to achieve a correspondingly increased performance.

It is also possible to approach several printing stations in succession and to provide a row between them for intermediate curing. Preferably For this purpose, the turntable 4 of the container 2 is provided on the cross member 3 with an angle coding, so you can clearly identify the zero point. This results in the following treatment sequence: surface activation by z. Eg plasma

 Printing of color set 1

 Hardening of color set 1

 Print of color set 2

 Hardening of color set 2

According to the invention, stations for filling and closing the containers within the same machine 1 can subsequently be connected downstream of the treatment stations 7 for preparing the printing, the printing process and the color curing. Thus, the existing container receptacle, the centering of the container, the transport device, the supply and delivery is not necessary a second time and achieved a low-cost system with multiple benefits.

In the second embodiment shown in FIG. 4, the machine 30 operates in a rotary cycle, wherein a plurality of treatment stations 32 are arranged in a star shape around a rotation center 31.

A rotating device 33 has a plurality of carriers 34, which are also arranged in a star shape around the center of rotation 31 below the treatment stations 32.

At a feed station 32a, a plurality of containers 2 arranged on a feed belt 35 or the like are gripped by a radially extendable gripping device 36a and deposited on a carrier 34 on which the containers 2 are held in the same way as in the first embodiment described above. be. Subsequently, the carriers 34 are rotated by means of the rotator 33 and positioned below the next treatment station 32b. At this treatment is carried out analogously to the pretreatment 7a in the first embodiment. Subsequently, the containers 2 with the carrier 34 are rotationally displaced to the next treatment station 32c and after the treatment there takes place to further treatment stations 32d to 32g, before they again radially at a removal station 32h, which is similar to the Aufgabestation 32a, via a gripping device 36h again lifted out of the machine and placed on a removal belt 37.

The treatment and mounting of the containers in the individual treatment stations is carried out in the rotary transfer machine 30 in the same manner as has been explained above with respect to the longitudinal clock machine 1. The difference between the embodiments is essentially only the way of transport between the individual treatment stations.

The advantage of the machines 1, 30 according to the invention over the conventional continuous rotary machines is the greater utilization of the printing heads 12, since all the printing heads 12 have no waiting time except when exchanging the containers. In addition, in the longitudinal-stroke machine, the engine 1 becomes smaller because there are no "empty spaces" in the center of the carousel (s).

Stationary printheads 12 do not produce centrifugal force affecting print quality and any stationary ink supply can be used. Special rotary feedthroughs are eliminated. Another advantage is the pressure at standstill. So there can be no vibrations through the barrel that can affect the print image. LIST OF REFERENCE NUMBERS

1 machine (longitudinal cycle)

2 containers

 3 cross members

 4 turntables

 5 centering

 6 conveyor belt

 7 treatment station 7a pretreatment

 7b print station

 7c post-treatment

8 lifting cylinders

 9 rotary drive

 10 format part

 1 1 rail

 12 printhead

 13 retaining plate

 14 cover

 15 vacuum channel

16 leadership

 17 end plate

 18 slides

 19 centering bolts

 20 UV lamps or e-beam

30 machine (rotary cycle)

31 shooting center

32 treatment station 32a feeding station bg treatment station Removal station Rotary device Carrier

 Feed belt, h Gripper Removal belt

Claims

claims: 1 . Machine (1) for printing on containers, such as bottles or cans, with a plurality of treatment stations (7) to which printheads (12) and possibly further equipment required for pre- and post-treatment of the containers (1) are provided, with a support ( 3) for a plurality of containers (2), which are arranged side by side on the carrier (3), characterized in that the carrier (3) via a conveyor belt (6) from one treatment station (7) to the next is transportable, that in each case a plurality of treatment stations (7) are arranged substantially in a row next to one another transversely to the conveyor belt (6), that the carrier (3) is arranged essentially transversely to the conveyor belt (6) and that the treatment stations (7) and the carrier (3) are substantially vertical Direction are relatively movable. 2. Machine (30) for printing on containers, such as bottles or cans, with a plurality of treatment stations (32) to which printheads (12) and possibly further for pre- and post-treatment of the container (1) required facilities are provided with a Carrier (34) for a plurality of containers (2) arranged side by side on the carrier (34), characterized in that the carrier (34) can be transported via a turning device (33) from one treatment station (32) to the next, wherein it rotates about a center of rotation (31), that in each case a plurality of treatment stations (32) are arranged substantially radially to the center of rotation (31) in series side by side, that the carrier (34) is arranged substantially radially to the center of rotation (31) and that Treatment stations (32) and the carrier (34) are movable in a substantially vertical direction relative to each other. 3. Machine according to claim 1 or 2, characterized in that the carrier (3, 34) upwards from the conveyor belt (6) or the rotary device (33) can be lifted. 4. Machine according to one of the preceding claims, characterized in that a plurality, in particular 4 to 7 print heads (12) in a treatment station (7 b, 32) are arranged annularly around the container (2). 5. Machine according to claim 4, characterized in that the print heads (12) are aligned with each other annularly aligned on a holding plate (13) are mounted. 6. Machine according to one of the preceding claims, characterized in that on the support (3, 34) turntable (4) for receiving the container (2) are provided, wherein the container (2) preferably by vacuum on the turntables (4) being held. 7. Machine according to one of the preceding claims, characterized in that along the machine (1) has a fixed vacuum channel (15) or a plurality of fixed vacuum channels (15) is arranged / from which / which the negative pressure for sucking the container (2) is fed. 8. Machine according to one of the preceding claims, characterized in that the carrier (3, 34) with the turntables (4) for receiving the container (2) is hollow and a negative pressure on laterally arranged in guides (16) of the vacuum channel (15) running end plates 17 from the one fixed vacuum channel (15) or the plurality of fixed vacuum channels 15 on the carrier (3, 34) is transmitted. 9. Machine according to one of the preceding claims, characterized in that a centering (5), which in particular on the container (2) can be placed, raised, lowered and / or rotatable and possibly by means of a motor or rotary drive (9) driven can be. 10. Machine according to one of the preceding claims, characterized in that above the support (3, 34) at the treatment stations (7, 32) the containers (2) associated with motors or rotary drives (9) are provided, which during lifting of the carrier ( 3) are raised by the arranged on this container (2) along its longitudinal axis, by their own weight, the container (2) center and thus transmit the rotational drive force to the container (2). 1 1. Machine according to one of the preceding claims, characterized in that at least one row of treatment stations (7c, 32) has one or more cover (s) (14), which optionally can be closed by the turntables (4). 12. Machine according to one of the preceding claims, characterized in that at least one row or a plurality of rows of treatment stations (7c, 32) has a common cover (14), which by the one or more carriers (3) can be closed. 13. Machine according to one of the preceding claims, characterized in that the carrier (3, 34), for example, by an eccentric clamp against the treatment station (7, 32) is mechanically clamped. 14. Machine according to one of the preceding claims, characterized in that a plurality, in particular two to four rows of similar treatment stations (7, 32) are arranged one behind the other. 15. Machine according to one of the preceding claims, characterized in that the treatment stations (7, 32) are mounted separately from the transport system (6, 33) on the ground.