EP2743087B2 - Printing machine with cladding - Google Patents

Description

The invention relates to a printing machine which is provided with a casing within which a predetermined atmosphere can be generated.

State of the art

It is known to surround machines in production halls, especially when producing bottles, with protective walls, for example made of Plexiglas. On the one hand, this achieves a certain level of safety for the operator and minimizes the risk of accidents; on the other hand, this cladding also offers a certain protection of the products processed or manufactured in the machine inside this cladding against external influences during the manufacturing process. However, since these protective walls are in most cases not designed to be fully comprehensive and furthermore only have a certain height in order to ensure the requirements with regard to occupational safety, protection against undesirable environmental influences is not given.

Furthermore, for example, in the DE 10 2009 041 527 A1 discloses a printing machine which comprises individual capsules at each container station of the printing machine, which capsules can enclose a container received by the container station in order to reduce airflow during transport through the printing machine. For this purpose, appropriate ventilation systems can also be provided in the capsules. However, the individual capsules are extremely maintenance-intensive and error-prone and there is still a risk of injury to operating personnel, since the machine is freely accessible.

Technical problem

The invention is therefore based on the object of providing a cladding for printing machines which improves protection against undesirable environmental influences and at the same time meets the requirements of occupational safety.

solution

This object is achieved by the device according to claim 1 and the method according to claim 9. The subclaims contain expedient developments of the invention.

The printing machine for direct printing of containers, wherein the printing machine comprises a cladding which is designed so that it separates the printing machine located therein from the surrounding space, with at least one supply line to guide the containers in the space inside the cladding and one outlet option, in order to guide the containers out of this space, is characterized in that the cladding separates the printing machine from the surrounding space in such a way that a controlled atmosphere can be generated within the cladding. This cladding allows printing to take place in a well-defined atmosphere.

According to the invention, the printing press is characterized in that it comprises a ventilation system with at least one main flow in which an air filter is arranged. The ventilation system is optionally suitable for generating an overpressure in relation to the pressure prevailing outside within the casing. By generating a (slight) overpressure, the undesired penetration of outside air is effectively prevented or can at least partially be suppressed.

In a further embodiment, the printing machine is characterized in that the ventilation system comprises a heating device for heating up recirculated process air, the heating device being arranged in a secondary flow branched off after the air filter, which returns the recirculated process air to the main flow upstream of the air filter. Since warmer air can absorb moisture better than less warm air, for example, it is advantageous to attach a heating device after an appropriate air filter, since the cold air, which per se can store less moisture than warm air, is first filtered and then heated up again to be able to be fed to the main flow before the air filter.

In a further embodiment, the ventilation system of the printing press is suitable for generating a constant temperature within the printing press and / or maintaining a constant air humidity and / or suppressing air currents that can lead to pressure mist distributions. By setting a predetermined temperature and a constant air humidity as well as the suppression of undesired air currents, it is ensured that the printing can be carried out in the printing press with predetermined atmospheric values.

In a further embodiment, the printing press is characterized in that a heating device is provided in the main flow. Sufficient heating can be achieved with this heating device. In a further embodiment, the printing machine comprises a wet separation system with at least one cooling system that can suck out process air and washout water, the washout water being able to be cooled by the cooling system to such an extent that the moisture content of the process air can be kept constant as it flows through the wet separation system . Appropriate cooling minimizes the ability of the process air to absorb moisture and a desired moisture content can be maintained. Even subsequent heating of the process air can no longer increase it as long as no additional water or moisture is added becomes.

In a further embodiment, the printing press is characterized in that a fine filter is provided in the main flow. Especially when using printing machines, deposits of residues, such as the ink used during printing or the adhesive, can occur during printing. Cleaning the process air from these impurities by means of a fine filter can, on the one hand, prevent the accumulation of moisture on these impurities and, on the other hand, ensure that containers to be printed are not soiled before printing.

In a further embodiment, the wet separation system comprises a circulating pump and / or a Venturi scrubber which contains at least one Venturi nozzle. This ensures a particularly good separation of the wash water from the recirculated process air.

Using this device, for example, a direct printing process of containers can be implemented, a controlled atmosphere being generated within the cladding. Direct printing under specified atmospheric conditions can lead to better and, in particular, always reproducible results, which can improve the quality of the products produced.

According to the invention, a ventilation system with at least one main flow, in which an air filter is arranged, is used to generate an overpressure with respect to the pressure prevailing outside the printing press inside the printing press. This suppresses or partially prevents the ingress of possibly contaminated outside air.

In one embodiment, the direct printing method is characterized in that recirculated process air is heated by a heating device, which is arranged in a bypass flow in the flow direction of the recirculated process air behind the air filter, and is passed through the bypass flow into the main flow in front of the air filter. Since the recirculated process air is only heated after it has passed through the air filter, the undesired absorption of humidity is prevented before it passes through the air filter, which means that it is less stressed and has a longer running time.

In a further embodiment, the ventilation system within the printing press maintains a constant temperature and / or maintains constant air humidity and / or suppresses air currents that can lead to pressure mist distribution. This ensures that printing is always carried out with a constant atmosphere within the framework of process-related fluctuations.

In one embodiment, the recirculated process air passes through a heating device provided in the main stream while it is flowing through it. This enables targeted and complete heating of the recirculated process air, so that it can always be brought to the required process temperature.

In a further embodiment, the direct printing process is characterized in that the process air is sucked out of the printing machine together with washout water by a wet separation system and the washout water is cooled by the wet separation system to such an extent that the moisture content of the extracted process air when flowing through the wet Separation system remains constant. This ensures that a certain value of the moisture contained in the process air is maintained and that this value is maintained even with subsequent heating of the recirculated process air, provided that no additional source of air moisture follows.

In one embodiment, the recirculated process air passes through a fine filter while the main flow is flowing through it. In this, for example, dirt that cannot be removed by the air filter can be filtered out. For example, dirt and impurities in the process air that have arisen from particles released during printing can be cleaned up here.

Brief description of the figures

Fig. 1:

Schematic representation of a machine in a fairing.

Fig. 2:

Schematic representation of the supply and discharge options.

Fig. 3:

Schematic representation of the ventilation system.

Detailed description

Fig. 1 shows a system 100. This system 100 consists of a machine 102 which can be used to manufacture or process containers. In particular, the machine 102 is a printing machine for printing containers 120. The printing machine can be operated cyclically, but it can also be a continuously rotating machine to increase performance. These containers can, for example, be any type of packaging and in particular bottles. The system 100 further comprises a casing 101 which separates the machine 102 located therein from the surrounding space 160. A space 170 is thereby created within the cladding 101. The separation of the space 170 from the surrounding space 160 by the cladding 101 takes place in such a way that at least one feed line 103 for feeding the containers 120 is provided, for example by means of a conveyor belt 106, and furthermore a diversion option 104 for diverting the processed containers 120 ', for example likewise by means of a conveyor belt 105, is provided. The space 170 “generated” within the cladding 101 is therefore not a closed or closed system in the physical sense. However, it is preferred that the inlet possibility 103 and outlet possibility 104 are selected to be as small as possible, preferably so small that only the corresponding conveying devices 106 and 105 and the containers 120 or even only the containers 120 and 120 'can be guided through these openings. Thus, the exchange of air from the outer space 160 with air from the inner space 170 is minimized as much as possible, or a (slight) overpressure can be generated within the cladding 101, with air then escaping to the outside through the inlet 103 and the outlet 104.

Furthermore, a ventilation system 107 is provided, which can control the indoor air or the atmosphere within the cladding 101 in the room 170. For this purpose, it is preferably equipped with means for monitoring and controlling the temperature, the air humidity and, if necessary, with devices for controlling air flows within the room 170. These means can in particular be sensors for determining the temperature and / or humidity in the ambient air. The ventilation system 107 is only used here as a collective term. A detailed description of the ventilation system and its use is given in Fig. 3 respectively.

Fig. 2 shows schematic representations of embodiments of the supply line options and exit options 203 and 204, respectively Fig. 2a again an overall view of the system 200. In addition to the in Fig. 1 recognizable openings in the cladding, there is also the possibility of providing the inlet possibility 203 and outlet possibility 204 in the cladding 201 in the form of extended locks. These are then not just openings in the cladding 201 but components with special functions. As boundary conditions, however, these must be able to guarantee the transport of the containers 220 or the processed containers 220 'after leaving the machine 202, which is why their dimensions must be selected so that the containers 220 can be conveyed to the machine 202 and the processed containers 220' can be discharged. can be done by the machine 202. Particularly preferably, this takes place without undesirable delays, such as the formation of jams in containers before the infeed option 203 or after passing through the machine 202 and before passing the diversion option 204 of a conveyor belt through them and / or which, if possible, only have simple means of separating the interior 270 from the exterior 260. Doors or permanently open openings are particularly preferred because they require little maintenance and are also easy to dimension.

Figure 2b shows one possible embodiment of a diversion option 204. The following figures only explicitly describe embodiments for the diversion option 204. It should be noted, however, that these can also be used in a non-modified form for the feed line option 203.

In Figure 2b the diversion option 204 is implemented by means of a sluice in which a permanent opening 210 is provided at the entrance, which preferably has the shape of the container 220 to be processed. In this context, the shape of the container 220 is to be understood as meaning that the opening 210 corresponds to an imaginary cross section of the container 220 as it is to be guided through the lock with the aid of the conveyor system 206. The profile of a bottle was used here as an example. However, a different profile for the opening 210 can also be selected according to the container 220 to be processed. Embodiments of the invention 210 are particularly preferred such that they are only slightly larger than the objects 220 to be processed if these are arranged on the conveyor system with appropriate accuracy. Particularly preferred are openings 210 that allow a clearance of 1 mm or 2 mm, preferably 5 mm, particularly preferably 1 cm in each direction, so that even a slight slipping of the container 220 to be processed can be compensated for and not against the opening 210 or the adjacent part of the cladding 201 abuts. It can also be preferred that the opening is designed as a rectangle, the dimensions of which in the direction perpendicular to the conveying plane 206 are selected such that they are slightly larger than the dimensions of the container 220 to be processed in this direction. Particularly preferred are dimensions that are 1 mm to 2 mm, but at most 5 mm larger than the object 220 to be processed. In addition to this opening 210, a further opening 210 'is provided at the opposite end of the lock through which the object to be processed from space 270 within the cladding 201. This opening can be the same as the first opening 210 in shape and size, but can also be designed according to one of the further embodiments described, if expedient.

Figure 2c shows a further embodiment of the lock or the feed line option 204, in which the opening 210 is designed as a gate. This gate can be designed, for example, by means of two sliding or hinged doors, as shown here, which can be moved along the directions of the arrows. However, it is also possible, instead of the two doors, to provide only one door or a gate that can be moved upwards or to the side or opened in order to to enable the container 220 to be processed to be moved in. If there is no container 220 in the vicinity of the opening 210, this can be permanently closed in this embodiment, so that no exchange of air or atmosphere present in the surrounding space 260 with the atmosphere present in the interior space 270 takes place. Here, too, a second opening 210 'is provided, which can be designed in accordance with the opening 210 or in accordance with another embodiment.

Further possibilities for realizing the supply possibilities and diversion possibilities are also conceivable. In particular, it can be advantageous to close the openings according to embodiment 2b with attached doors either behind or in front of the openings, so that when these doors are opened, there is still only one opening in the cladding 201 that is just large enough for the container 220 can get into the interior space 270 or can be diverted from it.

Fig. 2d shows another embodiment of a lock. In this case, an additional ventilation 250 is provided within the inlet or outlet possibility 204, which can suck in air. Both air from the interior space 270 inside the cladding 201 and outside air 260 from the space outside the cladding 201 are sucked in. This additional ventilation 250 is preferably designed in such a way that there is little or no transfer of outside air from the outside space 260 into the inside space 270 within the cladding 201. This additionally supports the effect of the cladding, so that the atmosphere within the cladding 201 in the room 270 remains set according to well-defined parameters. This additional ventilation can also help to prevent pressure mist from escaping from the device by providing appropriate suction for the pressure mist escaping from the device through the supply and / or discharge possibility 204.

Even if the Figures 2a-2d The machine shown only has a supply and a discharge option and an interior space 270, it is also conceivable to arrange further interior spaces in this interior 270, i.e. to provide further areas separated from one another by cladding, which in turn are preferably provided by corresponding supply and output options can be connected to each other. Additional machines, for example printing machines, which print the containers with different colors in pairs, can then also be provided in these further interior spaces. It is particularly advantageous here if the air is sucked off directly at the pressure modules, so that the interior space required can preferably be minimal.

Fig. 3 shows an embodiment of the in Fig. 1 Ventilation system shown only schematically. Overall, this ventilation system 390, which is shown here in the dashed area, is used to create an atmosphere within the cladding 301 in the interior 370 that meets certain requirements, in particular certain parameters. It is particularly preferred if the ventilation device 390 is able to build up a pressure within the cladding 301 that is slightly higher than the external pressure prevailing in the outer space 360. As a result of this slight overpressure, an undesired entry of outside air from the space 360 into the interior space 370 can preferably be completely prevented, even when the inlet or outlet option is opened. However, since it is technically difficult to completely prevent the entry of outside air from the outside 360 into the inside 370, the ventilation device 390 preferably has additional devices, the recirculated process air from the inside 370, which may be contaminated or with air the surrounding space 360 is mixed, can clean. In order to keep the influence of the ambient air penetrating from the surrounding space 360 into the interior space 370 within the cladding 301 low, an overpressure in the interior space 370 is preferred which is 1 hPa, preferably 2 hPa, particularly preferably 5 to 10 hPa above normal pressure or the current external pressure. In principle, pressure differences from the external pressure of 0.1 to 1 hPa, in particular 0.1 to 0.5 hPa, are also possible. The pressure in the inner space 370 and in the outer space 360 can be measured, for example, by means of sensors and the measured values can be evaluated by a control unit and the ventilation system can be controlled accordingly, so that the pressure difference remains constant as possible at all times.

When using locks for the supply or discharge option, the generation of the overpressure can either be dispensed with or it can be very low in the range between 0.1 and 0.2 hPa.

The ventilation system comprises a main flow with an air filter. This main flow is designed in such a way that it continuously sucks process air out of the interior space 370 and can clean it via the air filter 316 and then feed it back into the interior space 370. This can be seen with the aid of the arrow directions shown.

If the printing machine is of a type in which the print heads and / or the containers rotate at a speed that is sufficient to generate a wind that could deflect the pressure drops, the inlets for the process air can also be arranged in such a way that that it blows against this through the movement of the print heads and / or the container - preferably against the transport direction of the container.

It is also preferred that a secondary flow 319 ′, which comprises a heating device 315, is arranged after the air filter 316. When the recirculated process air passes through the air filter 316, it is not just direct passed into the interior 370 but also passes through the bypass flow 319 'to the heating device 315, where it is heated. Since it has already been cleaned, it can then be reintegrated into the main flow 319 in order to heat the recirculated process air. A desired temperature in the interior 370 can thus be achieved. It is particularly preferred that the heating device 315 can be regulated so that the heating of the recirculated process air can be controlled in order to achieve a predetermined value, for example.

Furthermore, a fine filter 317 can be arranged before or after the air filter 316, but preferably after the air filter 316, in order to remove small particles from the recirculated process air that may not have been removed by the air filter 316. In order to ensure the permanent overpressure in the inner space 370 compared to the outer space 360, a suction device can preferably be provided for sucking in outside air, which is then fed into the main flow 319 before passing through the air filter 316 and the possibly provided fine filter 317. It is then processed, optionally heated, and can thus be used in the interior 370. It can be useful here to heat the sucked-in air by means of a heat exchanger. For this purpose, the air in the machine can be led past a heat exchanger as soon as it re-enters the main flow. It gives off heat to them and also becomes drier because it can absorb less moisture. At the same time, the sucked in process air is led past another area of the heat exchanger and can thus absorb the heat absorbed by it.

It can also be advantageous if the ventilation system is designed in such a way that it sterilizes the process air or that only sterilized air is passed into the interior. This means that the containers can be sterilized at the same time. To generate the sterile air, a HEPA filter can be arranged in the flow direction of the process air to be recirculated before or after the air filters 316 and 317, which sterilizes the process air passed through it. In this way, conditions such as those in a clean room can also be met; the atmosphere in the interior of the machine can then be a clean room atmosphere. An additional sterilization of the container in the interior can take place by means of UV lamps, which are aimed at certain parts of the container or at the entire container.

It can also be advantageous to provide a cleaning system in the ventilation system in order to flush the ventilation system through and thus to clean it. In this way, particles of, for example, printing ink that adhere to surfaces can be removed. The cleaning system can work in a similar way to a CIP system, to the extent that a closed circuit for the cleaning liquid is established in a cleaning cycle. For example, sealing and / or connecting elements that can be advanced for this purpose could be provided in the area of the supply and / or discharge option, which can be advanced via drives in the cleaning cycle. For example, an outlet could be connected to an inlet for the air. If both are next to each other, the element could be a simple cap that is placed over both openings in a sealing manner.

Print heads of the printing machine could also be included in CIP cleaning.

It is advantageous here if additional optical sensors are arranged in the interior. These can be assigned to specific areas or parts of the printing press or the ventilation system and are preferably designed in such a way that they can recognize color deposits at the points to which they are assigned. If the color deposits exceed a certain limit value, a cleaning cycle can then be started automatically or a notification can be sent to the operator, who can then carry out the cleaning cycle, for example, in the next shutdown phase or maintenance phase.

A wet separation system can also be provided. If wash-out water occurs in the process that is carried out in machine 302, a correspondingly provided cooling device can be provided for cooling this wash-out water 314, with which process air sucked out can be cooled at the same time. The extracted process air then has a lower humidity after cooling because, due to the lower temperature, it can only absorb a smaller part of water vapor. This cooled air can then either be integrated into the main flow 319 in order to be further purified and then optionally heated, or it can be introduced directly into the interior 370. The wash water can also be processed accordingly by means of the ventilation device 390. The wet separation system preferably comprises a storage tank into which the wash water can be pumped. It can then be fed back into the wet separation system from this storage tank. By cooling the process air to be recirculated with the aid of cooling for the wash-out water, an additional cooling device in the ventilation device 390 can be dispensed with and at the same time it is achieved that the process air that was sucked out of the interior 370 is freed from excess humidity before it is reintroduced so that the recirculated process air has a predetermined humidity content.

Since there is preferably an overpressure compared to the outside air in the outside space 360 in the device, in particular in the cladding 301, the spread of secondary pressure distributions is effectively prevented, since outside air from the outside space 360 can penetrate into the inside space 370 with the help of the supply and discharge options on the one hand, and in particular by providing the overpressure, can be prevented can. By providing an additional ventilation device according to Figure 2D this effect is further supported.

Particularly preferably, a control device is provided which can control at least the ventilation device 390 in order to achieve certain predetermined operating parameters. This can control the output of the heater and, preferably, the setting of the overpressure. If, for example, it is necessary to carry out a certain printing process at a certain humidity F1 and another printing process at a certain humidity F2, the control unit can measure humidity and temperature by evaluating sensors provided in the interior 370 and then measuring these by controlling the ventilation system 390 set so that the necessary conditions are met. In addition to the additional ventilation 250 out Figure 2D In particular, an additional blower can be provided in the supply line, which dries the supplied containers, should they have an undesirable film of moisture, for example.

Claims (13)

1. Printing machine (102) for the direct printing of containers (120), the printing machine (102) comprising a cladding (101) which is designed such that it separates the printing machine (102) contained therein from the surrounding space (160), at least one infeed option (103) being provided to guide the containers (120) into the space (170) within the cladding (101), and an outfeed option (104) to guide the containers (120) out of said space (170), the printing machine being designed as a cyclically or continuously rotating printing machine, characterized in that the cladding (101) separates the printing machine (102) from the surrounding space (160) such that a controlled atmosphere can be produced in the space (170) within the cladding (101), wherein the printing machine (102) comprises a ventilation system (107), with at least one main stream (319) in which an air filter (316) is arranged, which is optionally suited to produce an overpressure relative to the externally prevailing pressure within the cladding (101).
2. Printing machine (102) according to claim 1, characterized in that the ventilation system (107) comprises a heating device (315) for heating up recirculated process air, wherein the heating device (315) is arranged in a secondary stream (319') which is branched off after the air filter (316) and which can return the recirculated process air into the main stream (319) in front of the air filter.
3. Printing machine (102) according to claim 1 or 2, characterized in that the ventilation system (107) is suited to produce a constant temperature within the cladding (101) and/or to maintain a constant humidity and/or to suppress air flows which may lead to pressure mist distributions.
4. Printing machine (102) according to any one of claims 1 to 3, characterized in that a heating device is provided in the main stream.
5. Printing machine (102) according to any one of claims 1 to 4, characterized in that the printing machine (102) comprises a wet separation system with at least one cooling system (314) which can suck off process air and washout water, wherein the washout water can be cooled by the cooling system (314) to such an extent that the humidity content of the process air while flowing through the wet separation system can be kept constant.
6. Printing machine (102) according to any one of claims 1 to 5, characterized in that a fine filter (317) is provided in the main stream (319).
7. Printing machine (102) according to claim 5, characterized in that the wet separation system comprises a circulating pump and/or a venturi scrubber which includes at least one venturi nozzle.
8. Direct printing method for the printing of containers by means of a cyclically or continuously rotating printing machine (102) which comprises a cladding (101) enclosing the printing machine (102), the containers being guided into the space within the cladding and the containers being guided out of the space after printing, characterized in that a controlled atmosphere is produced within the cladding (101), wherein, by way of a ventilation system (107), with at least one main stream (319) in which an air filter (316) is arranged, an overpressure relative to the pressure prevailing outside the printing machine (101) is produced within the printing machine.
9. Direct printing method according to claim 8, characterized in that recirculated process air is heated by a heating device (315) arranged in a secondary stream (319') in flow direction of the recirculated process air after the air filter (316), and is guided through the secondary stream (319') into the main stream (319) in front of the air filter (316).
10. Direct printing method according to any one of claims 8 or 9, characterized in that by way of the ventilation system (107) a constant temperature is kept within the printing machine (102) and/or a constant humidity is kept and/or air flows which may lead to pressure mist distributions are suppressed.
11. Direct printing method according to any one of claims 8 to 10, characterized in that the recirculated process air while flowing through the main stream (319) passes by a heating device provided therein.
12. Direct printing method according to any one of claims 8 to 11, characterized in that the process air together with washout water is sucked off by a wet separation system out of the printing machine (102) and the washout water is cooled by the wet separation system to such an extent that the humidity content of the sucked-off process air while flowing through the wet separation system remains constant.
13. Direct printing method according to any one of claims 8 to 12, characterized in that the recirculated process air while flowing through the main stream (319) passes by a fine filter (317).

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