EP3088315B1 - Deep draw packaging machine with strip puncher - Google Patents

Description

The invention relates to a thermoforming packaging machine according to the preamble of claim 1.

In thermoforming packaging machines, a container or trough is usually formed into a lower film in a forming station, a product is inserted therein and the trough is hermetically sealed in a sealing station with a top film under vacuum and / or modified atmosphere. The packs produced in this way are bound together as a composite over the lower film and are transported through double-sided staple chains through the thermoforming packaging machine. For separating the packages from the composite of the lower and the upper film, a combination of a cross-cutting station and a subsequent longitudinal cutting station can be provided. In the cross-cutting station, the composite of the lower and the upper film is cut transversely to the transport direction or, if radii are necessary at the edges of the packaging, strip cuts are punched out.

Since normally the space for a means for collecting within the machine frame or for transporting out of the machine frame is not sufficiently available, the punching knife usually punches from below coming down the strip cuts up out of the film. These are pushed further upwards in a receptacle after each cut and can then be removed collected. In high-performance machines, the receptacles are very high, so they do not have to empty constantly. The strip cuts are pushed over a paragraph, which is located above a film transport plane, and on which the last cut strip cut partially rests with its edge. This prevents the strip strips stacked above from falling down into the cross cutting station or onto the packages to be cut. In the latter case, it would also interfere with the thermoforming packaging machine and downtime.

Especially with thinner or non-rigid strip cuts the risk is great that the weight of the stacked strip cuts can not be held by the lowest resting strip cut.

From the DE 10 2012 204 502 A1 a punching device for separating strip-shaped edge regions emerges from a packaging web. In this stamping device, two different punching units are arranged behind one another in the transport direction of the packaging web, which in turn each have an upper part and a lower part. Details of the drives of these punching units are not disclosed in this document.

The WO 2012/102682 A1 discloses a packaging machine with a cutting station, wherein at least one drive for a cutting means or an antidote of the cutting station is arranged above the film web to be punched out.

The EP 2 447 171 A1 discloses a solution for the safe disposal of cutting waste, which is discharged upward, namely above the film plane.

The object of the present invention is to provide a thermoforming packaging machine with an improved strip punch.

This object is achieved by a thermoforming packaging machine with the features of claim 1. Advantageous developments of the invention are specified in the subclaims.

The thermoforming packaging machine according to the invention comprises a film punch with a common lifting drive for a die and a punch, wherein the die and the punch from the common lifting drive orthogonal to a film transport plane to each other are movable. A first lifting mechanism transmits the drive movement of the lifting drive to the punch, while a second lifting mechanism transmits the drive movement of the lifting drive to a movement of the die. The lifting movements performed by the punch and the die are preferably always in opposite directions. The thermoforming packaging machine according to the invention is characterized in that the lifting drive is arranged above the film transport plane. Thus, separated film strips can fall directly into a container or on a discharge belt, without causing contamination or negative impairment of the linear actuator.

In a particularly advantageous embodiment, the lifting drive comprises an electric motor, preferably a servomotor, for example additionally with a brake. In a conventional linear actuator with pneumatic cylinder, a foil punch is at rest in an open position and in the event of a falling pressure in the pneumatic cylinder supply lines, there is a risk of injury to the operator due to unexpected movement of an upper tool of the foil punch down. An electric motor, however, can drive a self-locking lifting spindle or have a brake, so that no danger to the operating or maintenance personnel emanates in the rest position of the foil punch. In order to monitor or test the function of the brake, the control of the thermoforming packing mesh may operate the electric motor with a defined torque while the brake is closed, and check whether an inadmissible movement is taking place.

It is expedient if the first lifting mechanism is completely above the film transport plane, because the film punch is particularly simple in this way. The second lifting mechanism, however, can have guide rods which are located laterally outside the foil transported in the foil lance and by means of which a drive movement of the lifting drive can be transferred to the die located below the foil transport plane.

The film punch may have a frame which is stationarily arranged on a machine frame of the thermoforming packaging machine. As a component of the second lifting mechanism, a bearing plate may be present, which moves relative to the frame of the foil punch up and down during operation of the foil lance and the movement of the lifting movement of the located below the film plane die is coupled to the movement. In a first variant of the lifting drive is rigidly attached to the frame, so that the bearing plate moves relative to the frame. In a second embodiment, however, the motor is attached to the bearing plate, so that it moves alternately up and down during operation of the foil punch together with the bearing plate relative to the frame of the foil punch.

The stamp preferably comprises a punching knife.

The die preferably has a recess into which the punching knife can dip.

The recess is preferably produced by means of wire EDM and / or by means of grinding.

Preferably, the punch and the punching knife are each made of several parts, so that larger dimensions of the punch and punching knife are made possible and an adjustment of the individual parts to each other.

The die preferably has several troughs so as not to collide with the containers of the lower foil, since the die has webs for stabilization aligned in the working direction of the thermoforming packaging machine.

The troughs preferably have a height of up to 60 mm in the vertical direction and / or a depth of 30 mm to 40 mm in the horizontal direction, in order to be suitable also for the processing of containers with large thermoforming.

The film punch is preferably configured to use the punch and the die to cut out a foil strip from a film composite and to convey it down through the die in order not to lift up any accumulation of foil strips and, for example, to accumulate or stack them in containers.

Preferably, the punch for the punching process vertically down and the die are carried out vertically movable upward.

The foil punch is preferably configured to carry out the movement of the punch and the die as much as possible at the same time in order to minimize the cycle time of the foil punch and to simplify the construction with only one electric motor.

In an advantageous embodiment, a container is provided below the die or the foil punch to receive the film strips. In this case, the container may have a fill level monitoring, which is connected, for example, with the control of thermoforming packaging machine to the operator to display the information about a due or even pending change or emptying of the container.

Figur 1

eine schematische Ansicht einer erfindungsgemäßen Tiefziehverpackungsmaschine,

Figur 2

eine schematische Ansicht in Arbeitsrichtung einer Querschneidestation,

Figur 3

eine schematische Ansicht eines Stempels und einer Matrize und

Figur 4

eine Schnittansicht der Matrize.

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

FIG. 1

a schematic view of a thermoforming packaging machine according to the invention,

FIG. 2

a schematic view in the direction of a cross-cutting station,

FIG. 3

a schematic view of a punch and a die and

FIG. 4

a sectional view of the die.

Corresponding components are consistently provided in the figures with the same reference numerals.

FIG. 1 shows a schematic view of a packaging machine according to the invention in the form of a thermoforming packaging machine 1. The thermoforming packaging machine 1 has a forming station 2, a sealing station 3, a cross-cutting station 4 and a longitudinal cutting station 5, which are arranged in this order in a working direction R on a machine frame 6. On the input side is located on the machine frame 6, a feed roller 7, from which a lower film 8 is withdrawn. In the region of the sealing station 3, a material reservoir 9 is provided, from which a top film 10 is drawn off. On the output side, a discharge device 13 in the form of a conveyor belt is provided on the packaging machine, with the finished, isolated packaging 21 are transported away. Furthermore, the packaging machine 1, a feed device, not shown, which engages the lower film 8 and transported in a main working cycle in cycles in the direction of R. The feed device can be realized, for example, by laterally arranged transport chains and transport the lower film 8.

In the illustrated embodiment, the forming station 2 is formed as a thermoforming station in which containers 14 are formed in the lower film 8 by deep drawing. In this case, the forming station 2 may be formed such that in the direction perpendicular to the working direction R a plurality of containers 14 are formed side by side. In the working direction R behind the forming station 2, an insertion path 15 is provided, in which the containers 14 formed in the lower film 8 are filled with products 16.

The sealing station 3 has a closable chamber 17 in which the atmosphere in the container 14 can be replaced with a replacement gas or exchange gas mixture prior to sealing, for example, by gas purging.

The cross-cutting station 4 is designed as a foil punch or concretely as a strip punch, which cuts through the lower film 8 and the upper film 10 in a direction transverse to the working direction R between adjacent containers 14. In this case, the cross-cutting station 4 operates such that the lower film 8 is not separated over the entire width, but at least in an edge region and between two adjacent containers 14 is not severed. This allows a controlled onward transport of the container 14 by the feed device.

The longitudinal cutting station 5 is formed in the illustrated embodiment as a knife assembly, with which the lower film 8 and the upper film 10 between adjacent Containers 14 and at the lateral edge of the lower film 8 are severed, so that behind the longitudinal cutting station 5 individualized packages 21 are present. Under the cross-cutting device 4, a movable container 33 is provided for receiving punching waste.

The packaging machine 1 also has a controller 18. It has the task of controlling and monitoring the processes taking place in the packaging machine 1. A display device 19 with operating elements 20 serves to visualize or influence the process sequences in the thermoforming packaging machine 1 for or by an operator.

The general mode of operation of the packaging machine 1 will be briefly described below.

The lower film 8 is withdrawn from the feed roller 7 and transported by the feed device into the forming station 2. In the forming station 2 containers 14 are formed by deep drawing in the lower film 8. The containers 14 are transported along with the surrounding area of the lower film 8 in a main working cycle to the insertion path 15 in which they are filled with product 16.

Subsequently, the filled containers 14 are transported along with the surrounding area of the lower film 8 in the main working cycle by the feed device in the sealing station 3. The top film 10 is transported on to the lower film 8 with the advancing movement of the lower film 8 after a sealing operation. In this case, the upper film 10 is withdrawn from the material storage 9. By sealing the upper film 10 to the container 14, sealed packages 21 are formed.

FIG. 2 shows the cross-cutting station 4 in the form of a film punch, by means of an electric motor Hubantriebs 22, preferably a servo drive or servomotor, a punch 23 down against the lower film 8 and the upper film 10, which together represent a composite film, while a film strip 32 from the In this case, the punch 23 cooperates with a die 24, which is simultaneously moved by means of the lifting drive 22 in opposite directions to the punch 23 from below against the lower film 8 and the upper film 10. The lifting drive 22 is configured, via a first lifting mechanism 25a, which is realized here in the form of a bent push rod 26, a plate 27 with the attached thereto Stamp 23 to move down. The motor 22 is mounted on a bearing plate 28. At the same time causes the motor 22 by its drive power, a relative movement of the bearing plate 28 relative to a frame 29 of the cross cutting station 4 upwards, wherein the frame 29 is stationarily arranged on the machine frame 6.

Via at least two guide rods 30, which are arranged in the drawing on the right and left side, a lifting plate 31 with the die 24 mounted thereon is rigidly connected to the bearing plate 28, so that the movement of the die 24 corresponds to the movement of the bearing plate 28. The bearing plate 28, the at least two guide rods 30 and the lifting plate 31 together form a second lifting mechanism 25b, by means of which the drive movement of the lifting drive 22 is transferred into a lifting movement of the die 24. Thus, the lifting drive 22 provides for a common mutual movement of the punch 23 and the die 24 for removing the film strip 32 and again for a moving apart of the punch 23 and the die 24 to allow a next slide preference.

After the separation of the film strip 32, it is pressed down by the die 23 through the die 24 and can fall down into the mobile container 33 provided with wheels 33a under the cross-cutting device 4. The container 33 is sensed by the controller 18 sensory whether this is in its predefined working position under the cross-cutting device 4, as he also for security reasons intervention of an operator in the cross cutter 4 from below through the machine frame 6 through during operation of the thermoforming packaging machine 1 should prevent.

Also conceivable is an alternative embodiment without such a container 33 and instead with a conveyor belt, which transports the film strips laterally to the working direction R from the thermoforming packaging machine 1 to the outside and a disposal device supplies.

A film transport plane E is defined by the film composite of the lower film 8 and the upper film 10 and by the alignment in the working direction R. Both the lifting drive 22 and the first lifting mechanism 25a are located completely above the film transport plane E.

Fig. 3 shows the punch 23 and the die 24. The die 24 has a recess 35 which is congruent with the contour of a punch blade 34 of the punch 23. The separated from the film composite film strip 32 can fall through the recess 35 of the die 24 down or pressed by the punching blade 34 down into the recess 35. The punch 23 and the punching blade 34 are formed in several parts from a plurality of interconnected parts A, B and C.

The die 24 is integral and made of stainless steel or other hardened steel and the recess 35 made, for example by means of wire EDM. The die 24 has four recesses 36, which serve as an exemption of the die 24 for the packages 21 and the containers 14. A height H of the troughs 36 is provided up to 60 mm and a depth T in the horizontal direction of 30 to 40 mm, to entice the die 24 a high stability. The recess 35 has a width B of 5 to 10 mm in the region of the smallest width. There is provided a cutting gap between the punching blade 34 of the punch 23 and the recess 35 of the die 24 of preferably 3 to 5 microns.

Fig. 4 shows the die 24 in a cross-sectional view transverse to the working direction R of the thermoforming packaging machine 1 in the center of the die 24. The recess 35 has in the upper part of a flat punching surface 37, which is parallel to the direction of movement of the punch 23 and die 24. The punching surface 37 has a width Z of at least 3 mm. Below this punching surface 37, the recess on an exemption 38, to facilitate falling of foil strips 32.

Claims (15)

1. A thermoform packaging machine (1) comprising a film punch unit (4) including a die (24) and a punch (23), characterized in that the die (24) and the punch (23), making use of a joint stroke drive (22), are movable orthogonally to a film conveying plane (E) towards and away from each other, a first stroke mechanism (25a) being provided for transmitting a movement from the stroke drive (22) to the punch (23) and a second stroke mechanism (25b) being provided for transmitting a movement of the stroke drive (22) to a movement of the die (24), and wherein the stroke drive (22) is arranged above the film conveying plane (E).
2. The thermoform packaging machine according to claim 1, characterized in that the stroke drive (22) comprises an electric motor, preferably a servo motor.
3. The thermoform packaging machine according to claim 2, characterized in that the stroke drive (22) drives a self-locking lifting spindle or comprises a brake.
4. The thermoform packaging machine according to one of the preceding claims, characterized in that the first stroke mechanism (25a) is arranged fully above the film conveying plane (E).
5. The thermoform packaging machine according to one of the preceding claims, characterized in that the film punch unit (4) comprises a frame (29), and that the stroke drive (22) is mounted on a bearing plate (28) that moves relative to the frame (29) when the film punch unit (4) is in operation.
6. The thermoform packaging machine according to claim 5, characterized in that a lifting plate (31) with the die (24) mounted thereon is rigidly connected with the bearing plate (28) via at least two guiding rods (30).
7. The thermoform packaging machine according to claim 4, characterized in that the second stroke mechanism (25b) comprises guiding rods (30) which are arranged laterally outside of the film transported in the film punch unit (4) and by means of which a driving motion of the stroke drive (22) is transferrable onto the die (24) which is arranged below the film conveying plane (E).
8. The thermoform packaging machine according to one of the preceding claims, characterized in that the punch (23) comprises a punching knife (34).
9. The thermoform packaging machine according to one of the preceding claims, characterized in that the die (24) comprises an opening (35).
10. The thermoform packaging machine according to claim 6, characterized in that the opening (35) is produced by means of wire eroding and/or by means of grinding.
11. The thermoform packaging machine according to one of the preceding claims, characterized in that the punch (23) and the punching knife (34) are each configured as a multi-part component.
12. The thermoform packaging machine according to one of the preceding claims, characterized in that the film punch unit (4) is configured for separating a film strip (32) from a composite film by means of the punch (23) and the die (24), and for conveying it downwards through the die (24).
13. The thermoform packaging machine according to one of the preceding claims, characterized in that the punch (23) is configured such that it is movable vertically downwards and the die (24) such that it is movable vertically upwards, for executing the punching process.
14. The thermoform packaging machine according to claim 13, characterized in that the film punch unit (4) is configured for executing the movement of the punch (23) and of the die (24) simultaneously to the greatest possible extent.
15. The thermoform packaging machine according to one of the preceding claims, characterized in that a container (33) is provided below the die (24) for receiving therein the film strips (32).

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