EP2479036A1 - Method and device for printing containers - Google Patents

Abstract

The device (10) has a printing station (30), which has two print heads (32) for printing on the container with multiple or different print colors. The print heads of each printing station are arranged one above the other or side by side. A handling unit is provided for horizontal positioning of the container during printing. An independent claim is also included for a method for printing of containers on their surfaces.

Description

The present invention relates to an apparatus and a method for printing on containers according to the features of the preambles of claims 1 and 11.

To the contents of containers, such as beverage bottles, PET bottles or similar. To mark, these are predominantly equipped by means of labels. For example, pre-printed labels are glued to the containers or bottles. Furthermore, shrink labels can be used in a shrink tunnel or similar. shrunk onto the containers. In addition, it is known to print the lateral surfaces of bottles and containers by means of adhesive inks or inks and thereby to identify. The application of a label by gluing or shrinking can thus be omitted.

A method of printing containers is disclosed, for example, in the publication DE 10 2007 050 490 A1 described. In this case, at least two printing heads operating according to the ink-jet printing principle are used. During printing, the containers are moved by a transport element in the transport direction, wherein the print heads of a printing unit are moved during a part of the at least one printing step with the transport element.

Furthermore, the shows EP 0 209 896 B1 a method and apparatus for decorating containers. In this case, individual color dots are applied to the wall of the container as a raster image along parallel circumferential lines in a program-controlled manner. The container is thereby rotated while the nozzles are arranged on a carriage, whereby the distance to the container can be adjusted.

If one chooses a suitable technology for printing, for example digital DOD inkjet printing, electrophotography or other suitable digital printing techniques, one obtains further advantages over the classically applied label. These consist in particular in the fact that no printing form is necessary, so that a quick change to variable content is possible. The creation of the print image is done by mouse click. Furthermore, the consumption of films, developers, chemicals, fixing tapes, etc. is eliminated that even small quantities are economically feasible. Digital printing techniques allow great flexibility in the desired design, for marketing etc.

In particular, the DOD (drop-on-demand) ink-jet technology has a number of advantages. The technology is one of the non-impact-printing processes in which there is no contact with the substrate. Furthermore, ink drops are produced only when needed. In addition, the use of UV-curable inks is possible.

The object of the invention is to provide a fast, continuously practicable method for printing on containers and to provide an apparatus for carrying out such a method.

The above object is achieved by an apparatus and a method comprising the features in claims 1 and 11.

The invention relates to a device for printing containers on their surfaces with the features of independent claim 1. Preferably, such a device is used to print on beverage containers, especially bottles, cans, etc. Such a device comprises at least one printing station which is associated with at least two print heads for printing on the containers. The at least two print heads are preferably equipped with different printing inks and arranged one above the other or side by side.

The device further comprises at least one handling device for approximately horizontal positioning of the containers during their printing. The device further comprises at least one handling device for variably positioning the containers in different vertical or horizontal levels. The differently adjustable levels correspond in each case with printheads of the printing station arranged at different heights or next to one another. Furthermore, at least one drying station and / or at least one pretreatment station can be arranged at different heights or next to each other to the print heads of the printing station and also correspond to the differently adjustable levels.

The device is preferably designed as a so-called pressure module with a peripheral transport device, wherein the handling device for holding and positioning the container in the region of an outer circumference of the Transport device is arranged, while the printing stations are preferably arranged closer to the axis of rotation at the periphery of the transport device and on the same.

According to a preferred embodiment, the printing module is designed as a rotating printing carousel with print stations distributed uniformly over the circumference. According to an alternative embodiment, the printing module is at least partially linear and has uniformly distributed over the circumference printing stations.

The print module is coupled to a container feed and a container discharge. These may be known transport stars, in particular an inlet star and an outlet star, an inlet or outlet screw or similar suitable systems for container feed and / or container removal.

The handling device for holding and positioning the container comprises a pivoting device for pivoting each container to be printed from a vertical position to an approximately horizontal position.

Depending on the selected variant of embodiment, the handling device further comprises a vertical conveying device for variably positioning the containers in different vertical levels, which respectively correspond to the printing heads of the printing station arranged at different heights. In this variant, the container by means of the feeder, eg. The transfer star, transferred to the printing carousel, placed there in a horizontal position and moved to printing in the vertical direction up and down to the respective printed container to the arranged at different heights print heads introduce. The printheads are each mounted on top of each other so that they eject their ink in a horizontal direction and print the container in this way. The printheads are fixed to the carousel and rotate with it.

According to an alternative embodiment, the handling device comprises a horizontal conveying device for variably positioning the containers in different horizontal levels, which respectively correspond to the printing heads of the printing station arranged side by side. In this case, the containers are not moved up and down, but brought in the same amount to the various printheads, which in this case, if necessary, their ink can eject from top to bottom, which may have advantages in terms of printing precision.

According to a further embodiment, in each case two print heads are arranged opposite one another in a printing station. The container to be printed is placed between the two print heads. As a result, the container can be printed successively or simultaneously from both opposite sides. During printing, the containers can each be rotated by a defined angle about their longitudinal axis or else rotate continuously about the same at a defined speed.

According to a further embodiment, at least two print heads are arranged in a star shape in a printing station. The container to be printed is in this case immersed in the printing station or the printing station is moved in the direction of the container longitudinal axis, that the printing station with the star-shaped printheads surrounding the container to be printed. During printing, the containers can each be rotated by a defined angle about their longitudinal axis or else rotate continuously about the same at a defined speed.

The printing station may further comprise at least one drying station for drying taking place immediately after printing, for example pre-drying or final drying of the containers. Furthermore, the printing station can be assigned at least one pre-treatment station, which subjects the containers, for example, to a corona or plasma treatment in which the surface energy of the material to be printed is increased, thereby improving the wettability of the surface to be printed. Additionally or alternatively, for example, cleaning methods or other preparation methods (heating or the like) may be used.

Furthermore, the printing station may comprise a monitoring device with corresponding sensors. The sensors may include, for example, camera systems, image recognition systems, or other suitable systems for monitoring the printing process, for properly positioning the containers with respect to the printheads, and / or for controlling the printing result. By way of example, the sensor system may be coupled to a suitable device which rejects incorrectly printed containers so that they are not fed to a downstream processing device.

The printing stations can continue to use covers to protect the printing units or to facilitate access to the printing units for cleaning purposes. be equipped.

For each batch to be processed of containers to be printed, a defined distance between the containers and the printing units is preferably preset, which is then no longer changed during the treatment of the same container of a batch. The distance between containers and printheads can be variable and is generally between 0.5mm to 0.8mm. The distance between the container to be printed and the print heads can preferably be further reduced, but also increased, preferably to ≦ 3 mm and in particular to ≦ 10 mm. The distance between the container to be printed and the printheads is particularly dependent on the architecture, the structure and the arrangement of the printheads, which can be variably selected.

When containers with a different diameter or perimeter are printed in a new batch, the position of the printheads at a defined distance from the handling device is readjusted in order to again obtain the optimum distance between the surface to be printed and the printhead.

Furthermore, the print heads are preferably modular and easy to replace, so that they can be easily replaced if errors occur, dehydration, in another desired color pattern, etc.

The invention further relates to a method for printing containers on their surfaces by means of printing stations, which are each associated with at least two printheads for printing the container with multiple and / or different inks. The print heads can be arranged one above the other or side by side.

The containers to be printed are first positioned approximately horizontally within a printing station. Subsequently, a variable positioning of the containers in different vertical or horizontal levels corresponding to the different heights or juxtaposed printheads.

While the container passes through the different levels of the printing station, the container and the printing station is continuously moved by the rotating transport device in the direction of container removal. With the method and the device, therefore, a continuous printing with a plurality of colors, an optional pre-treatment and / or an optional aftertreatment, in particular a drying, are possible.

In the method according to the invention and the device according to the invention, it is advantageous to "rest" the printing stations relative to the containers. The movement on the revolving transport device takes place synchronously with the movement of the handling device in which the containers to be printed are positioned. A movement of the printheads against the containers is deliberately avoided. In this invention, the printheads preferably remain stationary, instead the containers to be printed are moved by rotation about their longitudinal axis relative to the printheads.

According to an alternative embodiment, the printheads may be controlled via a sensor. In particular, the sensor recognizes the bottle contour and the print heads are moved accordingly laterally due to the data obtained from it in order to set the optimal distance between the container and the print head and thus to achieve the optimum printing result. Thus, in this embodiment, the position of the printheads is not fixed but is dynamically controlled depending on the containers to be printed.

According to a further embodiment, the printheads, depending on the type of bottle to be printed, can be "scanned" over a previously defined profile / program, whereby the necessary dynamic movement or adjustment can likewise be generated. In this embodiment, no sensor for distance measurement and adjustment is necessary.

As described by two examples, the positioning of the printheads during the printing process can be adapted, which is particularly advantageous when printing on containers with an oval diameter, since the distance between the container and printhead changes continuously as the container rotates about its longitudinal axis.

By way of example, the sensor may be a picture-recognizing system which forwards the ascertained data, in particular the contour, height and width of the container to be printed, to a computing unit. Based on the transmitted data, the optimal distance between the container and the printhead is calculated. The arithmetic unit then controls the appropriate positioning of the printhead or printheads.

With the present invention, the container once clamped in a handling device can be completely treated. An alignment or a complex synchronization with other printing stations is thus eliminated. Since all movements are controlled by the movement of the containers, no calibration is necessary during the process, since the distance of the printheads is previously known or defined preset or can be controlled dynamically, no error-prone referencing must be performed.

The device can be built as a so-called. Rotary. This is advantageous due to a continuous inlet and outlet of the containers and a continuous carousel rotation.

With the device it is also possible to provide the containers with special markings. If the containers are arranged, for example, between opposite printheads, different printed images can be produced on the opposite sides of the containers.

The method and the device are used in particular for direct printing on the lateral surface of containers. Alternatively, it is also possible to print on the container located labels or coatings or wraps.

• Figur 1 zeigt eine schematische Darstellung einer Vorrichtung zum Bedrucken von Flaschen.
• Figur 2 zeigt eine erste Ausführungsform einer Druckstation zum Bedrucken von Flaschen.
• Figur 3 zeigt zweite Ausführungsform einer Druckstation zum Bedrucken von Flaschen.

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions of the individual elements to one another in the figures do not always correspond to the actual size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration.

• FIG. 1 shows a schematic representation of an apparatus for printing on bottles.
• FIG. 2 shows a first embodiment of a printing station for printing on bottles.
• FIG. 3 shows second embodiment of a printing station for printing on bottles.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are merely examples of how the device or method of the invention may be configured and are not an exhaustive limitation.

FIG. 1 shows a schematic representation of an apparatus 10 for printing on bottles 20. In particular, the apparatus 10 comprises a printing module 12 having a plurality of printing stations 30.

The bottles 20 to be printed are fed to the printing module 12 via an inlet star 2. The device 10 is designed so that it allows a continuous bottle transport at the transfer point between inlet star 2 and pressure module 12.

In the exemplary embodiment shown, the printing module 12 comprises a continuously rotating carousel, in particular a continuously rotating transport star 14, to which at least one, preferably a plurality of printing stations 30 are assigned. Each printing station 30 comprises a bottle holder 40 on the transport star 14. The bottles 20 are here - as in FIG. 2 shown - preferably clamped between the mouthpiece 22 and bottle bottom 24 and centered. In the exemplary embodiment shown, the printing stations 30 are each arranged in a stationary manner on the printing module 12 and rotate with it.

The bottle receptacle 40 includes means 42 for pivoting or tilting the bottle 20 from the incoming vertical layer Lv to a substantially horizontal position Lh. Furthermore, the bottles 20 can be pivoted by means of this pivoting device 42 to the transport star 14 to the outside or inwards or be turned upside down.

The bottle receptacle 40 further comprises means 44 to move the bottles 20 about its longitudinal axis X, in particular to rotate, and means 46 for changing the vertical position of the bottles 20, so that they can be moved relative to the transport star 14. In the exemplary embodiment shown, these means are designed as vertical conveying devices 46, which serve to vertically change the position of the bottles 20 and to position them in accordance with the printing heads 32 arranged in different vertical levels N1... N6 (cf. FIG. 2 ).

After the transfer of the bottle 20 to the respective bottle holder 40, the bottle 20 is pivoted in a preferably horizontal working position. In the exemplary embodiment shown, the bottle 20 is pivoted toward the center of the transport star 14 into a printing station 30. The printing station 30 is arranged so that a defined distance from the bottle 20 is maintained.

For the pretreatment of the bottles 20 to be printed, a pre-treatment station 50, for example a cleaning device, in particular a blow-off or drying station, can be arranged upstream of the inlet star 2 of the device 10.

For the aftertreatment of the printed bottles 20, an after-treatment station 52, for example a device for final drying, in particular a drying tunnel, in particular a UV tunnel, can be arranged downstream of the outlet star 4.

A printing station 30 is in FIG. 2 It may, for example, be a module for gas flame, corona or plasma treatment in which the surface energy of the material to be printed is increased, whereby the wettability of the surface to be printed is improved. Additionally or alternatively, for example, cleaning methods or other preparation methods (heating or the like) may be used.

The printing station 30 further comprises at least two printing heads 32, which are preferably each provided with different printing inks.

Furthermore, the printing station 30 comprises a drying station 34 for drying or curing the printed colors.

The pre-treatment station 36, the printheads 32 and the drying station 34 are each horizontally aligned and arranged one above the other at different vertical levels N1... N6, the printheads 32 preferably being arranged between the pretreatment station 36 and the drying station 34. The drying station may in particular be a UV lamp or the like. act suitable drying agent.

According to another embodiment, an arrangement is also possible in which N1 is a pretreatment, N2 a print head, N3 an intermediate drying, N4 a print head and N5 a final drying. Other deviating arrangements are also conceivable.

In addition, a printing station 30 may comprise at least one monitoring device (not shown) with corresponding sensors, camera systems, etc., which monitor the printing process and / or the printing result.

Furthermore, sensors (not shown) may be provided which detect the contour of the bottles 20 to be printed and regulate the optimum distance between the bottles to be printed and the print heads 32 of the printing station 30.

Preferably, two mutually opposite pretreatment stations 36, print heads 32 and drying stations 34 are arranged within a printing station 30, so that the bottle 20 to be printed can be positioned between them and simultaneously treated or printed from two sides.

The bottles 20 are now moved by means of a vertical conveyor 46 via a vertical relative movement vB in the various working positions to the corresponding treatment station 32, 34, 36 in the different vertical levels N1 ... N6 of the printing station 30. According to a first embodiment it can be provided that the bottles 20 rest at the individual treatment stations 32, 34, 36 for a defined time and are treated there. According to an alternative embodiment, the bottles 20 are continuously moved past the treatment stations 32, 34, 36 and thereby printed or treated.

While the bottle 20 passes through the individual treatment stations 32, 34, 36, the transport device 14 and with it the bottle 20 and the printing station 30 continue to move.

After the bottle 20 has passed through the treatment stations 32, 34, 36, it is moved back into the starting position or transfer position, swung back into the vertical position Lv and to an outlet star 4 (see. FIG. 1 ) to hand over.

FIG. 3 shows second embodiment of a printing station 30 for printing on bottles 20. Here, the treatment stations 32, 34, 36 are arranged horizontally adjacent to each other, so that the bottle 20 must perform a relative movement in a horizontal plane to the various treatment stations 32, 34, 36 to get.

The bottles 20 are in turn clamped in a bottle receptacle 40 and can rotate therein at least partially about its longitudinal axis X.

The horizontal movement of the bottles 20 between the treatment stations 32, 34, 36 is carried out in particular by means of a horizontal conveyor 48, wherein the bottle 20 is moved, for example, by a servo motor (not shown) along a servo-linear axis S.

The invention has been described with reference to a preferred embodiment. However, it will be apparent to those skilled in the art that modifications or changes may be made to the invention without departing from the scope of the following claims.

LIST OF REFERENCE NUMBERS

2

feed star

4

outlet star

10

Device for printing on bottles

12

print module

14

transport star

20

bottle

22

mouthpiece

24

bottle bottom

30

printing station

32

printhead

34

drying station

36

pretreatment station

40

bottle storage

42

swivel device

44

rotation means

46

Vertical conveyor

48

Horizontal conveyor

50

pretreatment station

52

post-treatment station

lv

vertical position

lh

horizontal position

N1 - NX

vertical level

R

rotational motion

S

Servo linear axis

vB

vertical relative movement

X

longitudinal axis

Claims (15)

Apparatus (10) for printing on containers (20) on their surfaces, having at least one printing station (30) associated with at least two printing heads (32) for printing the containers (20) with a plurality of and / or with different inks, wherein the Printheads (32) of each printing station (30) are arranged one above the other or side by side, with at least one handling device (40) for approximately horizontal positioning of the containers (20) during printing and at least one handling device (46, 48) for the variable positioning of the containers ( 20) at different levels (N1-Nx), wherein the differently adjustable levels (N1-Nx) each correspond to printheads (32) of the printing station (30) arranged at different heights and / or next to one another. Device according to claim 1, wherein at least one differently adjustable level (N1-Nx) corresponds in each case to at least one drying station and / or pretreatment station arranged at different heights and / or next to each other. Device (10) according to claim 1 or 2, wherein the device (10) is a printing module (12) with a circulating transport device (14). Device (10) according to claim 3, wherein at least two printing stations (30) are arranged on the circulating printing module (12), which is coupled to a container feed and a container discharge. Device (10) according to claim 3 or 4, wherein the printing module comprises a rotating printing carousel (14) with uniformly distributed over the circumference printing stations (30) or wherein the printing module (12) at least partially linearly formed transport device and evenly distributed over the circumference printing stations (30). Apparatus (10) according to claim 4 or 5, wherein the container feeder an inlet star (2) and the container discharge is an outlet star (4). Device (10) according to one of the preceding claims, wherein the handling device (40) comprises a pivoting device (42) for pivoting the container (20) to be printed from a vertical position (Lv) into an approximately horizontal position (Lh) Apparatus (10) according to any one of claims 1 to 7, wherein the handling means for variably positioning the containers (20) at different vertical levels (N1-Nx) is a vertical conveyor (46), the different vertical levels (N1-Nx) respectively with the arranged at different heights print heads (32) of the printing station (30) correspond. Apparatus (10) according to any one of claims 1 to 7, wherein the handling means for variably positioning the containers (20) at different horizontal levels (N1-Nx) is a horizontal conveyor (48), the different horizontal levels (N1-Nx) respectively correspond with the same height next to each other arranged printheads (32) of the printing station (30). Device (10) according to one of the preceding claims, wherein in each case two print heads (32) are arranged opposite to each other and wherein the container to be printed (20) between the two print heads (32) is arranged. Method for printing containers (20) on their surfaces by means of printing stations (30), which are each assigned at least two print heads (32) for printing the containers (20) with a plurality of and / or with different inks, the method comprising at least the following method steps includes: • approximately horizontal positioning of the containers (20) before printing; Variable positioning of the containers (20) in different vertical or horizontal levels (N1-Nx) corresponding to the different heights and / or juxtaposed print heads (32) of the printing station (30). A method according to claim 11, wherein the containers (20) in continuous conveying pass through the printing stations (32) arranged on a circulating printing module (30), the circulating printing module (30) being designed as a rotary printing carousel with printing stations distributed uniformly around the circumference, or wherein the printing module (30) is formed at least partially linear and uniformly distributed over the circumference printing stations (32). Method according to one of claims 11 or 12, wherein the printing of each container (20) in the respective printing station (30) by means of a plurality of print heads (32) each having different printing inks in each case different levels (N1 - Nx). Method according to one of claims 11 to 13, wherein the containers (20) are each printed by one or simultaneously or successively from both opposite sides. Method according to one of claims 11 to 14, wherein prior to printing within the printing station (30), a pretreatment and / or after printing within the printing station (30), a post-treatment, in particular a drying takes place.

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