EP2860119B1 - Deep draw packaging machine and method - Google Patents

Description

The invention relates to a thermoforming packaging machine according to the preamble of claim 1 and to a method according to the features of claim 11.

It is from the EP 0 569 933 A1 a thermoforming packaging machine with a print mark sensor for detecting a print mark of a lower film known. The print mark sensor is mounted in front of a forming station and communicates data to a controller which positions work stations such as forming station, sealing station and / or cutting station according to the distance between two successive print marks.

The EP 2 551 203 A1 discloses a method for cutting packages. In the process, packing troughs, which are formed into a film, are sealed with a cover film. It is described that in this sealing process, a reference element can be introduced. When separating the packs, the position of the sealing seams or of the reference element can be detected by a recognition device and the position of the cuts in the singulation can be adjusted accordingly.

Out WO 2012/116823 A1 is a packaging machine for the production of packaging from printed webs known. This is intended to ensure that a packaging tray formed in a web of material coincides with a printed image printed on the web. For this purpose, the position of a print mark is checked after each feed step. If this needs to be corrected, this is achieved by changing the role guidance by means of a so-called dancer. This changes the stretching of the web such that the print mark is located at the intended location. For non-stretchable webs, it changes the roller guide such that the position of the print mark iteratively approaches the intended position during the following advancing steps.

From the DE 24 37 127 A1 For example, a thermoforming packaging machine having a print mark sensor for detecting a print mark of a lid film is known. The print mark sensor is attached to the Folienabrolleinrichtung the lidding film and transmits data to a controller. Workstations such as forming station, sealing station and / or cutting station are motor-driven along a film transport direction and can be positioned according to the distance between two successive print marks. Another print mark sensor can be used between the sealing station and the cutting station may be provided to position the cutting station after the print mark.

The DE 101 52 39 A1 discloses a thermoforming machine with roller chains for transporting a film web. By means of sensors, the temperature of the roller chains is detected and moved a punching station horizontally with respect to their distance to a forming station by means of a control via a servomotor to compensate for the changing conditions caused by the operation of change of the transport steps of the roller chains can.

The EP 1 513 729 B1 discloses a thermoforming packaging machine having forming stations for lower and upper film webs, both films being shrink films.

In a thermoforming packaging machine, which has a forming station of a lid film in addition to the forming station of a lower film, and thereby both film webs have a printing and a print mark, it is particularly difficult to merge the molding of both film webs in the sealing station exactly in their desired position to each other and seal. For example, it is important in the production of a package in the form of a sphere or other geometric body by means of two half-shells, each having a circular shell edge, that the two half-shells or the sealing edges in the sealing station are superimposed on each other. If both film webs printed, it is often necessary that in addition the respective imprint on the film webs must be positioned in the molding of both half-shells, so that in turn in the sealing station both half-shells and their imprint are exactly in the desired position to each other.

Object of the present invention is to provide a thermoforming packaging machine available, which allows the most accurate possible merger of a hollow molding and a lid forming in the sealing station.

This object is achieved by a thermoforming packaging machine with the features of claim 1 or by a method for operating such a thermoforming packaging machine with the features of claim 11. Advantageous developments of the invention are specified in the subclaims.

The thermoforming packaging machine according to the invention comprises a controller, a first forming station arranged along a production direction for forming depressions in a lower film and a second, motor-adjustable forming station for forming caps in a top film, and a sealing station stationary in the production direction for sealing a plurality of Troughs with lids. Furthermore, the thermoforming packaging machine comprises at least one transport chain for transporting the lower film in the production direction. The thermoforming packaging machine is characterized in that a first detecting means is provided at or in the sealing station for detecting the mark of the lower film and transmitting the information thereon to the controller, the controller being configured to carry out a film feeding step of the transporting chain during transportation the troughs in the sealing station depending on the position of the marking of the lower film to regulate. In this case, the first detection device is configured to always detect that marking of the lower film which is associated with the troughs currently located in the sealing station in order to regulate the length of the current film advancing step to the exact target position in the sealing station.

In this case, the troughs, for example, a predetermined position for marking, which in turn is known to the controller and is entered by an operator or was already deposited in the production of the thermoforming packaging machine in the controller. This has the advantage that even existing inaccuracies, sluggishness or changes, for example due to temperature differences on the feed system, in particular on the feed chain, can be detected by the detection of the marking of the lower film at the first detection device and by means of the control, the transport of the lower film into the sealing station can take place in such a way that the depressions can be positioned exactly in their position to or in the sealing station. The first detection device is also configured to always detect the mark of the lower film, which is associated with the wells and thus the format, which are currently in the sealing station, and to control the film feed to the exact position. For this purpose, the first detection device z. B. have a camera and be arranged at a defined distance from the sealing station so that it detects during or directly after the destination of certain wells in the sealing station, the location of belonging to these wells marker to influence based on the positioning of the wells at the finish line or readjust. According to the invention, the first detection means is provided at or in the sealing station when it is positioned so that it can detect the position of a mark associated with those troughs (or a format, ie a related group of troughs) currently located in the sealing station are located, or the maximum of one power stroke (ie a feed length) before or after the sealing station.

Preferably, a second detecting means is provided between the first forming station and the first detecting means for detecting the mark of the lower film and transmitting the information thereon to the controller, the controller being configured to position the second forming station so that the the second mold station in the upper film shaped lid and the associated trough of the lower film in the sealing station in their mutually provided position are sealable. Thus, the exact position of the lid in the sealing station and thus the exact position can be achieved to the trough. Lid and wells can be positioned congruent to each other in the sealing station. This is particularly advantageous in the case of spherical or egg-shaped packages, which have, for example, a centrally located sealing plane or division, in order to be able to produce a shapely packaging.

The second forming station is preferably arranged a maximum of five, preferably a maximum of three film advance steps in front of the sealing station in order to minimize tolerances or changes in the film transport of the top film to the sealing station.

In a particularly advantageous embodiment, the marking is a print mark on the lower film and a third detection means is provided in front of the first forming station to detect the print mark of the lower film and the information about it to the controller wherein the controller is configured to position the first forming station in dependence on the print mark of the lower film.

In a further advantageous embodiment, a stretching device for the top film is provided to stretch a printed top film according to the transport direction, so that the printed image fits the later finished packaging.

In this case, the stretching device is preferably arranged in the transport direction of the top film upstream of the second forming station in order to stretch the printed image to the desired size even before forming into a lid.

Preferably, the stretching device has a print mark detection device, for example a print mark sensor, for the upper film in order to communicate the position of the print mark to the control. In addition, then the controller includes a print mark control, so that the controller in turn can control actuators such as clamping devices and / or drives of the stretching device such that a proposed stretching of the upper film can take place.

In a further advantageous embodiment of the thermoforming packaging machine, a fourth detection device is provided downstream of the sealing station for detecting the marking of the lower film or the print mark of the upper film and transmitting the information thereon to the controller, the controller being configured one located downstream of the sealing station Position the cutting station in dependence on the position of the marking of the lower film or the print mark of the upper film. Thus, the position of the cutting station can be aligned exactly to the packaging or the sealed seam, since the seal is predetermined in their position to the associated marking. Thus, the cutting can be carried out without the addition of tolerances and a particularly shapely packaging with the least possible protrusion of the sealing edge or the sealed seam can be produced.

At least one of the detection devices, preferably the first detection device, is preferably a camera in order to detect the position of the marking even during and above all at the end of the film advance step of the lower film until the film advance step has ended and the lower film has been transported exactly into the sealing station.

The marking is preferably provided as a marking on the lower film, which is applied by means of a printing device, or as a shaping, which is produced in the lower film in the forming station, or as a punch, in which the lower film by means of a Punching device is introduced. This allows the use of sub-films that have no prefabricated print marks, and the first forming station may be provided stationary on the machine frame.

• Formen von Mulden in der ersten Formstation in eine Unterfolie,
• Formen von Deckeln in eine Oberfolie mittels einer zweiten Formstation,
• Ausführen von Folienvorschubschritten zum Transport der Unterfolie in einer Produktionsrichtung,
• Erfassen einer Markierung der Unterfolie mittels einer ersten Erfassungseinrichtung an oder in der Siegelstation, sowie Übergeben dieser Information an die Steuerung,
• Mittels der Steuerung: Regeln des Folienvorschubschritts, bei dem die Mulden in die Siegelstation transportiert werden, in Abhängigkeit von der Position der Markierung der Unterfolie.

In the method according to the invention for operating a thermoforming packaging machine with a controller, a first forming station, a sealing station and a first detecting device, the following steps are provided:

• Forming cavities in the first molding station in a lower film,
• Forming lids in a top film by means of a second forming station,
• Carrying out film feed steps for transporting the lower film in a production direction,
• Detecting a marking of the lower film by means of a first detection device at or in the sealing station, as well as passing this information to the controller,
• By means of the control: controlling the film advancing step, in which the troughs are transported into the sealing station, depending on the position of the marking of the lower film.

In this case, the first detection device is configured to always detect that marking of the lower film which is associated with the troughs currently located in the sealing station in order to regulate the length of the current film advancing step to the exact target position in the sealing station.

The troughs have a fixed relative position to the mark. This has the advantage that even existing inaccuracies, sluggishness or changes, for example due to temperature differences on the feed system, in particular on the feed chain, by detecting the marking of the lower film at the first detection means can be detected and by means of the control of the transport of the lower film in the sealing station can be made such that the wells can be positioned exactly in their desired position to the sealing station. The first detection device is also able to detect the marking of the lower film, which is assigned to the troughs that are currently located in the sealing station, and to control the film feed to the exact position. For this purpose, the first detection device z. B. have a camera and be arranged at a defined distance to the sealing station so that they during or directly after the destination entrance certain Troughs in the sealing station detects the position of the mark associated with these troughs in order to influence or readjust the positioning of the troughs at the destination entrance based thereon.

In one possible embodiment, the marking is a marking which is applied by means of a printing device on the lower film, or a molding which is introduced into the lower film in the forming station, or a punch, which is punched into the lower film by means of a punching device.

In a particularly advantageous alternative embodiment, the marking is a print mark on the lower film and a third detection device detects the print mark of the lower film in front of the first forming station and transfers this information to the controller to position the first mold station according to the detected print mark, wherein the first mold station is adjustable by motor.

Preferably, by means of a second forming station, a lid is formed into an upper foil in order to be able to produce a packaging which has two formations, one shaping being the depression in the lower foil and a further shaping of the lids in the upper foil. This is a ball-shaped and centrally divided or zusammengesiegelte, shapely and thus attractive packaging produced.

Preferably, a second detection device, which is arranged between the first forming station and the sealing station, detects the marking of the lower film and transfers this information to the controller. In this case, the second forming station is preferably positioned along the transport direction of the top film by means of the controller as a function of the position of the marking of the bottom film which was detected by the second recording device.

In an advantageous embodiment of the method, a cutting station is positioned along the production direction by means of the control in dependence on the position of the marking of the lower film, which was detected by the first detection device, in order to achieve an improved position of the cutting to the packaging or sealed seam.

In an alternative embodiment, a fourth detection device is provided at or in the cutting station; and the cutting station is positioned along the production direction by means of the control depending on the position of the mark of the lower film or the mark of the upper film detected by the fourth detecting means. In this case, an exact position of the cut to the packaging or sealed seam can be achieved, since any tolerances and inaccuracies in the film feed can be compensated during and until the end of each foil advancing step.

Fig. 1

eine erfindungsgemäße Tiefziehverpackungsmaschine in einer schematischen Seitenansicht, und

Fig. 2

einen Vertikalschnitt durch die erste Formstation.

In the following, an advantageous embodiment of the invention is explained in detail with reference to a drawing. In detail show:

Fig. 1

a thermoforming packaging machine according to the invention in a schematic side view, and

Fig. 2

a vertical section through the first forming station.

The same components are provided throughout the figures with the same reference numerals.

Fig. 1 shows an inventive, cyclically working thermoforming packaging machine 1 with a machine frame 2, which is aligned along a production direction R. At the right in the Fig. 1 shown beginning of the thermoforming packaging machine 1, a first unwinding device 3 is provided for a lower film 4. The lower film 4 is by means of two driven by a servo motor M feed chains or transport chains 30 (s. Fig. 2 ) with a feed length V per cycle in the production direction R of a first forming station 5, wherein the first forming station 5 is generated by deep drawing in the film 4 wells 8 and is designed to be motorically movable in the production direction R. Furthermore, an insertion path 6 for inserting a product 7 into molded hollows 8 downstream of the first forming station 5 is shown. In the further course of production, a sealing station 9 for closing the troughs 8 filled with product 7 with a top film 10 and a first cutting station 11, which is designed as a cross-cut. A second cutting device 12, which is arranged downstream after the first cutting device 11, is designed as a longitudinal cutting and separates the packages 13. The first cutting station 11 can also be designed as a complete cutting station, which is motor-movable in the production direction R, then the second cutting station 12 omitted. About a conveyor belt 14, the isolated packaging 13 are transported out of the thermoforming packaging machine 1.

A first detection device 16 in the form of a camera or a print mark sensor for the sealing station 9 is arranged upstream of the sealing station 9 in the production direction R. A second detection device 17 in the form of a camera or a print mark sensor for a second molding station 18, which forms cover 24 in the upper film 10, is arranged between the first molding station 5 and the first detection device 16. An optionally provided third detection device 15 in the form of a camera or a Print mark sensor for the first forming station 5 is arranged in the production direction R upstream of the first forming station 5.

The top film 10 is unwound from a second unwinding device 19 and fed to a stretching device 20, which is arranged in a transport direction T of the top film 10 in front of the second forming station 18. The stretching device 20 has a print mark sensor 21, which transfers the position of print marks 10a of the upper film 10 to a controller 22, so that the controller 22 by means of at least one actuator 23, the upper film 10 is stretched, so that a predetermined distance of two adjacent print marks 10a of the top film 10 is generated.

It can be arranged in the production direction R troughs 8 in the lower film 4, which are transported as a format with, for example, three adjacent troughs 8 (ie as a three-lane format) by one trough 8 in one cycle intermittently downstream. However, it is also conceivable that the forming station 5 forms per cycle several consecutive rows of wells 8 and each of these formats of wells 8, which are formed in a working cycle in the forming station 5 in the lower film 4, cyclically in the direction of production R is transported , A power stroke also includes a film advance step with feed V.

In the following, the operation of the shown thermoforming packaging machine 1 will be explained in more detail. The lower film 4 unrolled by the first unwinding device 3 is detected on both sides by the feed chains 30 and fed to the forming station 5. In the forming station 5, one or more depressions 8 are formed in the lower film 4 and in a defined position relative to a marking 4a of the lower film 4. In order to always achieve this defined position, the position of the marking 4a is determined by the third detection device 15 and the forming station 5 is adjusted or positioned in the direction R before each molding process if necessary. The marking 4a is already present as a print mark on the lower film 4. Alternatively, the first forming station 5 is statically attached to the machine frame 2 and the mark 4a is first generated in the forming station 5. For example, the marking 4a is a forming in the lower film 4, which can be produced by a forming die 31, or a punching which is produced by means of a punching device 32 in, in front of or directly after the forming station 5 and thus obtains a defined position with respect to the recess 8. It would also be conceivable to print the marking 4a in the form of a marking by a printing device 33 on the lower film 4.

In the next working cycle, the lower film 4 with the shaped recesses 8 is transported intermittently along the insertion path 6. The troughs 8 are filled manually or automatically, for example by means of pickers with products 7. During the film advancement step, in which the filled trough 8 is transported into the sealing station 9, during the positioning, the marking 4a is detected by the first detection device 16, which is designed as a camera, and the current position of the marking 4a is transmitted to the control 22, to regulate the length of the current film advancing step to the exact target position in the sealing station 9. The distance X of the third detection means 15 to the forming station 5 and thus to the wells 8 corresponds to the distance X 'of the first detection means 16 to the sealing station 9 and thus to the wells 8. This negative influences such as tolerances in the feed chain 30, feed chain elongation due to temperature differences or Stress by different sub-films 4, which are transported laterally biased, can be eliminated. The always congruent position of the sealed seam opposite the trough 8 makes it possible to minimize the width of the sealed seam to a level necessary for the respective packaging 13. In this case, the wells 8 have a minimum possible distance from each other, which in turn leads to a reduction in the consumption of the film material of the lower film 4 and upper film 10 and improves the appearance of the package 13 itself.

For a package 13 having a molded lid 24 formed into the top film 10 by deep drawing in the second forming station 18, the second forming station 18 is positionable by the controller 22 in conjunction with an electromotive drive, preferably a servomotor or linear drive in order to adapt the shaping of the lid 24 at a distance Y to the sealing station 9 and thus to the troughs 8. The designated second detection means 17 for the marking 4a of the lower film 4 is arranged at a distance Y 'in front of the sealing station 9 along the insertion path 6 and the distance Y' corresponds to the distance Y. The position of the marking 4a is from the second detection means 17 at transmits the controller 22, which positions the second forming station 18, so that the lid 24 can be exactly merged with the associated trough 8, the position of which was detected via the marking 4a, in the sealing station 9 in order to produce a very attractive packaging 13 can. Especially with two hemispherical half-shells, the invention has a very positive effect.

If the cover 24 has an associated printed image, which is applied to the top film 10, the top film 10 is stretched in front of the second forming station 18, since the repeating Print images and print marks 10a on the top film 10 have a minimally shorter distance from one another than the distance that the cover 24 after molding in the transport direction T to each other and should correspond to the spacing of the wells 8 in the production direction R. The stretching process, also known as print mark control, can proceed as follows. The print mark sensor 21 detects the print marks 10a of the upper film 10 during the advancing movement of the upper film 10 in the transport direction T, which is produced by sealing the upper film 10 to the lower film 4 in the sealing station 9 and transporting the film as well as the lower film 4 the upper film 10 unwinds from the second unwinding device 19. The signal of the print mark sensor 21 is transmitted to the controller 22. The controller 22 compares the determined distance between two successive print marks 10 a with the distance required in the sealing station 9. The controller 22 controls the actuator 23, which may be implemented as one or more pneumatic cylinders, to clamp the top film 10 between the second unwinding device 19 and the print mark sensor 21 at the end of the current film advancing step and to stretch the top film 10 to a certain extent , in which the clamping takes place shortly before the end of the film advancing step. Alternatively, a servomotor not shown is provided on a clamp to stretch the top film 10 by a linear or rotary movement of the clamp. Thus, tolerances with respect to the printed image can be corrected and compensated so that the size and position of the printed image when forming in the second mold station 18 are in a suitable form.

In order to be able to carry out the cutting process exactly, a fourth detection device 25 is provided for detecting the marking 4a of the lower film 4, which is, for example, a complete cutting station 11 and is motor-driven along the production direction R by means of the control 22. The fourth detection device 25 has a distance X ", which corresponds to the distance X and X ', upstream of the complete cutting station 11 or the troughs 8. Thus, a cut seam produced in the sealing station 9 and a cut running directly outside the seal seam can be carried out since positional tolerances of the recess 8 for cutting, namely the cutting blade, are minimized and thus an excess of the cutting against the sealing seam is not necessary, resulting in a further improved appearance of the package 13. The detecting means 15, 16, 17 and 25 can be implemented as a camera, in particular as a CCD or line scan camera.

In the execution of thermoforming packaging machine 1 of Fig. 1 the second forming station 18 is arranged two film feeding steps of the sealing station 9 upstream along the transport direction T of the top film 10 above the lower film 4.

In one embodiment, in which the marking 4a of the lower film 4 is a print mark already present on the lower film 4, the first forming station 5 is designed to be motor-adjustable in order to position the forming station 5 in accordance with the print mark 4a by means of the controller 22. In this case, the print mark 4 a is detected by the third detection device 15 in front of the first forming station 5 and this information is transferred to the controller 22.

Claims (15)

1. Thermo-forming packaging machine (1) comprising a controller (22), a first forming station (5) disposed along a direction of production (R) for forming trays (8) into a base film (4) and a second adjustable forming station (18) for forming lids (24) into a top film (10), and a sealing station (9) for sealing trays (8) with lids (24), and at least one conveyor chain (30) for transporting said base film (4) in said direction of production, (R), characterized in that a first detection device (16) is provided in or on said sealing station (9) for detecting the position of a marking (4a) of said base film (4) and transmitting this information to said controller (22), where said controller (22) is configured to control a film advance step of said conveyor chain (30) in dependence of the position of said marking (4a) of said base film (4) during transport of said trays (8) into said sealing station (9), and wherein the first detection device (16) is configured to always detect the marking (4a) of the base film (4) which is associated with the trays (8) that are currently located in the sealing station (9) in order to control the length of the current film advance step to the exact target position in the sealing station (9).
2. Thermo-forming packaging machine according to claim 1, characterized in that a second detection device (17) is provided between said first forming station (5) and said first detection device (16) for detecting the position of said marking (4a) of said base film (4) and transmitting this information to said controller (22), where said controller (22) is configured to position said second forming station (18) such that said lid (24) and said associated tray (8) are sealable in said sealing station (9) to each other in their intended position.
3. Thermo-forming packaging machine according to one of the preceding claims, characterized in that said second forming station (18) is disposed a maximum of five, preferably three film advance steps upstream of said sealing station (9).
4. Thermo-forming packaging machine according to one of the preceding claims, characterized in that said marking (4a) is a print mark on said base film (4), and a third detection device (15) is provided upstream of said first forming station (5) for detecting said marking (4a) of said base film (4) and transmitting this information to said controller (22), where said controller (22) is configured to position said first forming station (5) in dependence on the position of said marking (4a) of said base film (4), where said first forming station (5) is adjustable in a motorized manner.
5. Thermo-forming packaging machine according to one of the preceding claims, characterized in that said a stretching device (20) is provided for said top film (10).
6. Thermo-forming packaging machine according to claim 5, characterized in that said stretching device (20) in disposed in the direction of transport (T) of said top film (10) upstream of said second forming station (18).
7. Thermo-forming packaging machine according to claim 5 or 6, characterized in that said stretching device (20) comprises a print mark detection device (21) for said top film (10).
8. Thermo-forming packaging machine according to one of the preceding claims, characterized in that a fourth detection device (25) is disposed downstream of said sealing station (9) for detecting said marking (4a) of said base film (4) or said print mark (10a) of said top film (10) and transmitting this information to said controller (22), where said controller (22) is configured to position a cutting station (11) disposed downstream of said sealing station (9) in dependence on the position of said marking (4a) of said base film (4) or said print mark (10a) of said top film (10).
9. Thermo-forming packaging machine according to one of the preceding claims, characterized in that at least one of said detection devices (15, 16, 17, 25) comprises a camera.
10. Thermo-forming packaging machine according to one of the preceding claims 1 through 3 and 5 through 9, characterized in that said marking (4a) is provided as an identification mark (33) creatable by a printing device (33) on said base film (4), as a molding into said base film (4) in said forming station (5), or as a punch into said base film (4) by use of a punching device (32).
11. Method for operating a thermo-forming packaging machine (1) with a controller (22), a first forming station (5), a sealing station (9), and a first detection device (16), comprising the steps of:

    - forming trays (8) into a base film (4) in said first forming station (5),

    - forming lids (24) into a top film (10) using a second forming station (18),

    - performing film advance steps for transporting said base film (4) in a direction of production (R),

    - detecting the position of a marking (4a) of said base film (4) by use of said first detection device (16) in or on said sealing station (9), and passing this position information to said controller (22),

    - using said controller (22): controlling said film advance step in which said trays (8) are transported into said sealing station (9) in dependence of the position of said marking (4a) of said base film (4);

    wherein the first detection device (16) is configured to always detect the marking (4a) of the base film (4) which is associated with the trays (8) that are currently located in the sealing station (9) in order to control the length of the current film advance step to the exact target position in the sealing station (9)..
12. Method according to claim 11, characterized in that said marking (4a) is an identification mark that is applied by a printing device (33) on said base film (4), or a formed feature that is introduced into said base film (4) in said forming station (5), or a punch that is created in said base film (4) by use of a punching device (32).
13. Method according to claim 11, characterized in that said marking (4a) is a print mark on said base film (4) and a third detection device (15) detects the position of said print mark (4a) in said base film (4) upstream of said first forming station (5) and passes this information to said controller (22) for positioning said first forming station (5) according to said detected print mark (4a), where said first forming station (5) is adjustable in a motorized manner.
14. Method according to one of the claims 11 through 13, characterized in that a second detection device (17) being disposed between said first forming station (5) and said sealing station (9) detects the position of said marking (4a) of said base film (4) and passes this information to said controller (22).
15. Method according to claims 11 and 15, characterized in that said second forming station (18) is positioned along the direction of transport (T) of said top film (10) by said controller (22) in dependence of the position of said marking (4a) of said base film (4) that was detected by said second detection device (17).

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