Patent Application
20200277095
This Application claims priority to German Patent Application No. 102019202755.5 filed on Feb. 28, 2019 to Peter Buchberger and Thomas Pfalzer, currently pending, the entire disclosure of which is incorporated herein by reference.
The invention relates to the field of packaging machines for packaging products.
Known packaging machines, such as thermoforming packaging machines or tray sealers, comprise work stations for carrying out processing steps for the production of a product packaging. For example, a sealing station can be provided which seals filled packaging trays or filled packaging trays thermoformed into a lower film web by sealing on a top film. The sealing station can comprise a heatable sealing tool for sealing the top film on by exertion of heat and pressure. Another example of a work station of a packaging machine is a forming station that forms packaging trays to be filled into a base film web by thermoforming.
Heating elements, for example in the form of a resistance heater, can be integrated into a tool of a work station for heating the tool. In order to keep the temperature of the tool in a suitable range during operation, a temperature sensor can also be provided in the tool, based on the sensor output of which the heating elements are operated according to a control procedure. It is known from practice that the heating elements are controlled by a central machine control device of the packaging machine. Corresponding switching elements for suitably supplying the heating elements with electric current, such as relays, can be provided in a control cabinet of the packaging machine.
It is known from DE 10 2016 125 132 A1 to provide a bus node arrangement at the individual work stations, such as a sealing station or a forming station, of a packaging machine, in which electronics is disposed that would have been disposed in the central control cabinet in conventional machines. The space requirement in the central control cabinet is thus reduced. The bus node arrangement is arranged on the outer side of the wall of the work station for easy access for maintenance purposes. Provided on a board of the bus node arrangement are, inter alia, electrical or electronic control elements for actuating a heating element of a tool of the work station. When the tool is installed in the work station, a connection of the tool, via which, for example, the heating elements are supplied with electrical current, is linked to a connection of the bus node arrangement.
DE 10 2016 117 834 A1 describes a sealing member that can be heated using heating conductors for the production of packagings made of thermoplastic materials such as plastic films. The sealing member comprises a housing that is formed to be attached to a packaging machine. Control electronics and/or a power electronics is to be arranged within the housing, so that the sealing member can be used autonomously, so the packaging machine itself does not have to effect the control or regulation function of the sealing member, because this is accomplished by the sealing member itself. The packaging machine only needs to provide the general energy supply and possibly the definition of certain target variables required for the sealing process, such as the target temperature.
The drawback in the operation of known packaging machines is that, at the start of production, a heating-up time of the heatable tools in the work stations must first be observed. Such a delay is particularly disadvantageous when resuming production after a tool changeover. Heating up the newly installed tool in the respective work station can indeed take some time and thereby delay resumption of production.
It is an object of the invention to provide a method for operating a packaging machine which allows rapid resumption of production by simple means after a tool changeover.
The invention specifies a method for operating a packaging machine comprising a work station with an exchangeable tool. The method comprising the steps of providing a control device that may be integrated into the tool. Wherein, when the tool is in a state installed into the work station, the control device may regulate a temperature of the tool based on an operating temperature target specification by suitably supplying a heating device integrated into the tool with electrical power. Further, wherein, when the tool is in a state removed from the work station, the tool may be connected to an external power supply, and the control device may regulate the temperature of the tool based on a preheating temperature target specification by suitably supplying the heating device with electrical power provided by the external power supply.
The invention allows first preheating the tool in the state removed from the work station by connecting it to the external power supply by way of the control device based on the preheating temperature target specification. If the preheated tool is then installed into the work station, then packaging operation can optimally commence directly or at least faster than with a non-preheated tool since the tool temperature required during operation may already be available or at least reached faster. This may avoid or reduce any delay in the commencement of operation when the packaging machine is restarted or when the tool is exchanged. The installation of the preheated tool may require handling the hot tool. However, safe handling of the hot tool may be possible if appropriate protective measures are taken and the tool is adequately designed and staff is sufficiently trained.
It is particularly advantageous to have the temperature of the tool in the work station be regulated based on the operating temperature target specification (during packaging operation of the packaging machine) as well as the temperature of the tool in the removed state of the tool be regulated based on the preheating temperature target specification by the control device integrated into the tool. It may therefore not be necessary to provide a pre-heater with its own control device for preheating the tool outside the work station. It may instead be sufficient if the tool in the state removed from the work station may simply be connected to an external power supply which may provide electrical power for the operation of the heating device and electrical power for the operation of the control device of the tool.
Since the control device may be integrated into the tool itself, it may also be possible to operate tools that require differently configured control devices in the same work station and to connect them to the same external power supply. The configuration of the control device integrated into the tool can be respectively adapted to the properties of the tool, for example to the number, sizing and positioning of the heating devices in the tool.
The operating temperature target specification and/or the preheating temperature target specification can be temperature target values. However, it would also be conceivable to regulate the temperature of the tool not to a certain value, but to a certain range. The operating temperature target specification and/or the preheating temperature target specification could therefore also be formed as a target temperature range.
In one embodiment, the external power supply may provide the tool with electrical heating power, but not provide control or regulating signals. Controlling preheating can be taken care of entirely by the control device integrated into the tool. In addition to the electrical heating power, the external power supply can provide the tool with electrical power to operate the control device. For example, the external power supply can comprise a power cable, with or without a mains supply unit, for connecting to the tool and to a power outlet. However, it would also be conceivable to have the external power supply comprise a docking station into which the tool can be inserted or to which the tool can be docked.
According to one embodiment, the preheating temperature target specification of the control device may be determined by a machine control device of the packaging machine. The machine control device of the packaging machine can in particular transmit the preheating temperature target specification to the tool prior to the removal of the tool from the work station. If the tool is preheated prior to being reinstalled in the work station, this can be done based on the preheating temperature target specification previously transmitted by the machine control device of the packaging machine. In this way, the preheating temperature target specification can be adapted in a simple manner to the configuration of the packaging machine. In addition, it is possible without a great additional effort in time that the preheating temperature target specification may be specified to the tool based on user input at the packaging machine via the machine control device of the packaging machine.
It would also be conceivable that the preheating temperature target specification may be available to the control device as a preset specification, in particular “ex factory.” The preheating temperature target specification could be permanently stored in the tool itself. Combinations could also be conceivable in such a way that a standard value for the preheating temperature target specification may be initially available as a preset specification, but that it can be changed by the machine control device of the packaging machine in the state of the tool installed in the work station.
The control device may comprise a memory in which the preheating temperature target specification may be stored (for example as a preset specification or after transmission by the machine control device of the packaging machine).
According to one embodiment, the control device may be put into a preheating mode, in particular by the machine control device of the packaging machine, prior to the removal of the tool from the work station. After connection to the external power supply, the control device removed from the tool may recognize that it is in the preheating mode and may begin with regulating the temperature of the tool based on the preheating temperature target specification. When the tool is reinstalled into the work station, it can exit the preheating mode and be put into a packaging operating mode by the machine control device of the packaging machine in which it can regulate the temperature of the tool based on the operating temperature target specification. The control device can already be present in the preheating mode prior to a first installation in the work station (i.e. quasi “ex factory”).
It is conceivable that the control device, after connecting to the external power supply, may detect that there is no communication connection to a machine control device of the packaging machine, and may then start regulating the temperature of the tool based on the preheating temperature target specification. The preheating mode could therefore be recognized by detecting a lack of a communication connection to the machine control. It may then not be necessary for the machine control device to actively set the tool to the preheating mode. If the tool is reinstalled into the work station and a communication connection to the machine control device is established, then the control device could switch back to regulating the temperature of the tool based on the preheating temperature target specification.
The operating temperature target specification can be specified to the control device by the machine control device of the packaging machine. However, since the tool itself may comprise the control device, no further requirements are absolutely necessary on the part of the packaging machine except for a power supply and optionally specifying the operating temperature target specification. Specifying the operating temperature target specification by the machine control device of the packaging machine may allow for an adjustment of the temperature of the tool based on the respective operating situation of the packaging machine, possibly also during operation. Alternatively, however, it would also be conceivable that the operating temperature target specification may be already pre-stored in the control device.
In the state of the tool installed in the work station, the control device can be in communication connection with the machine control device of the packaging machine. For example, the preheating temperature target specification and/or the operating temperature target specification can be transmitted to the control device via this communication connection. However, it is also conceivable that the control device or other devices integrated into the tool could send data to the packaging machine via the communication connection. For example, transferring a tool ID would be conceivable. The communication connection between the control device and the machine control device of the packaging machine may be effected by way of a communication bus system. A corresponding bus node may be integrated into the tool.
In principle, the work station can be any work station of the packaging machine that comprises a tool to be heated. The work station may be a sealing station of the packaging machine, and the tool may be a heatable sealing tool for sealing a filled packaging, in particular by sealing on a top film. The work station could also be, for example, a forming station of the packaging machine and the tool could be a heating plate for heating a lower film web. The tool could in particular be a heatable form punch.
The invention may be applied to a packaging machine that is a thermoforming packaging machine or a tray sealer. However, it would also be conceivable to apply the invention to other packaging machines, for example a bag forming, filling and sealing machine.
At least one temperature sensor may be integrated into the tool, and the control device may use a value provided by the temperature sensor for regulating the temperature of the tool. In this way, regulating the temperature of the tool can be carried out particularly precisely. In addition, all components required for regulating may be integrated into the tool.
The temperature sensor and the control device can be integrated into the heating device as a joint module. This may reduce the manufacturing effort for the tool. Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures.
In the following, an advantageous embodiment of the present invention will be explained in more detail making reference to a drawing, in which the individual figures show:
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.
The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled.
The invention relates to a method for operating a packaging machine 1. According to an exemplary embodiment shown in
The invention is also applicable to packaging machines 1 of other types. Shown as an example of this in
Sealing station 9 of the tray sealer or sealing station 9 or the forming station 21 of the thermoforming packaging machine, respectively, are examples of work stations that perform a specific function in the respective packaging process.
Tool 31 can be heated in order to be able to process the packaging appropriately. For this purpose, a heating device 35 is integrated into tool 31. In the variant shown in
In addition, a bus node module 39 is integrated into tool 31 and in the state of tool 31 installed in the work station is in communication via a communication bus 41 of packaging machine 1 with machine control device 17 of packaging machine 1. In the installed state of tool 31, bus node module 39 is additionally supplied with electrical power by packaging machine 1 via an electrical connection 43.
When installing tool 31 in work station 9, 21, or when starting up work station 9, 21 with tool 31 installed, control device 45 is put into a packaging operating mode by machine control device 17 of packaging machine 1, if it is not already in the packaging operating mode. In the packaging operating mode, control device 45 regulates a temperature of tool 31 based on an operating temperature target specification by suitably supplying heating device 35 with electrical power (by appropriately controlling switching elements 53). This ensures that the temperature of tool 31 is maintained in a range suitable for processing the packagings. The operating temperature target specification can specify a temperature target value or a temperature target range. The operating temperature target specification of control device 45 is preferably transmitted via communication bus 41 by machine control device 17 of packaging machine 1. The operating temperature target specification can be determined automatically by machine control device 17 based on stored values and/or operating parameters of packaging machine 1 or can be set by user input. The operating temperature target specification can be stored at least temporarily in memory 51 of control device 45.
In order to avoid or reduce delays caused by the initial heating up of tool 31 when starting up the packaging machine or upon resumption of the packaging operation after tool 31 has been exchanged (for example due to a change of format), tool 31 is preheated according to the invention already outside work station 9, 21. For this purpose, tool 31 in the state removed from work station 9, 21 is connected to an external power supply 57.
Controlling the temperature of tool 31 during preheating is likewise effected by control device 45 integrated into tool 31. Control device 45 is put into a preheating mode by machine control device 17 of packaging machine 1 prior to the removal of tool 31 from work station 9, 21 or is in the preheating mode once the connection to machine control device 17 via the communication bus 41 is lost. Control device 45 can also be in the preheating mode ex factory. If tool 31 is connected to external power supply 57 while control device 45 is in the preheating mode, or without an active communication connection to machine control device 17, respectively, control device 45 recognizes that it is in preheating mode and regulates the temperature of tool 31 by suitably supplying heating device 35 with electrical power provided by external power supply 57 based on of a preheating temperature target specification. The preheating temperature target specification can be stored in memory 51 of control device 45. The preheating temperature target specification can be present in memory 51 in particular as a preset specification. However, it is also conceivable that the preheating temperature target specification of control device 45 was previously transmitted in the state of tool 31 installed into work station 9, 21 by machine control device 17 of packaging machine 1 and stored in memory 51. The preheating temperature target specification could be determined automatically by machine control device 17 of packaging machine 1 based on stored data and/or an operating condition of packaging machine 1 or be determined based on user input.
Tool 31 preferably comprises a signal device 59 which is controlled by control device 45 to output a signal that indicates a termination of the preheating process. For example, signal device 59 could be an LED that flashes during the preheating process and illuminates continuously once the preheating process has been completed.
After the preheating process has terminated, tool 31 is disconnected from external power supply 57 and installed into work station 9, 21. Tool 31 is then connected to power supply 43 and communication bus 41 of packaging machine 1 by way of connecting suitable plug-in devices. Machine control device 17 of packaging machine 1 then puts control device 45 via communication bus 41 from the preheating mode back into the packaging operating mode in which the temperature of tool 31 is regulated based on the operating temperature target specification.
Due to the fact that tool 31 was preheated before the installation into work station 9, 21, the operation of packaging machine 1 can ideally start immediately after tool 31 has been installed.
From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting.
The constructions and methods described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention.
As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required.” Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102019202755.5 | Feb 2019 | DE | national |
