EP4275796B1 - Packaging machine with device for crushing strip-shaped material and method for its operation - Google Patents

Description

The invention relates to a packaging machine according to the preamble of claim 1. Furthermore, the invention relates to a method according to independent claim 11.

State of the art

In thermoforming packaging machines, a film, the so-called bottom film, is usually pulled off in webs from a first roll and is then conveyed through the packaging machine by means of transport means, preferably clamp chains. Film is understood here to be a material suitable for packaging foodstuffs, in particular this can be a composite film made of several plastic layers, a fiber-based material, a combination of plastic and fiber-based material or the like. On its way through the thermoforming packaging machine, the bottom film is processed by various stations of the thermoforming packaging machine. Usually, one or more troughs are formed in the bottom film in a forming station and a product is then placed in them. Another film, the so-called top film, is fed into the packaging process from a second roll. This is placed on the troughs and sealed in a sealing station or sealed airtight under vacuum and/or modified atmosphere. The packages produced in this way are connected as a composite via the bottom film. To separate the packaging from the composite of the lower and upper film, a combination of a cross-cutting station with a subsequent longitudinal cutting station can be provided. In the cross-cutting station, the composite of the lower and upper film is cut transversely to the direction of transport. The area of the film composite that is held by the clamp chains is usually not severed. In the longitudinal cutting station, the packaging is then cut in the direction of transport. The now separated packaging falls onto a designated conveyor belt and is transported away. So-called edge strips initially remain in the clamp chains, which must be disposed of as waste products. Since the edge strips are not severed transversely to the direction of transport, they are essentially endless strips. These edge strips are specifically guided out of the clamp chains into a clamp chain deflection, which is located in the end area of the thermoforming packaging machine. The edge strips are usually wound up using a winding device or fed to a waste container using a suction device. However, both devices have the disadvantage that they have to be emptied frequently by the operator because the edge strips are difficult to wind or lay and the waste material therefore takes up a large volume in a short space of time. During the emptying process, the packaging machine usually has to be stopped, which significantly reduces the productivity of the system.

From the EN 10 2008 039 841 A1 and the DE 299 07 834 U1 There are shredding devices that use knives to cut the edge strips into small pieces before they are fed into a waste container. This offers the advantage that the volume of the waste is significantly reduced and the emptying intervals can be increased.

The requirements for packaging materials have increased steadily in recent years. There are special packaging materials that have been developed specifically for different foods. In addition, the proportion of sustainable components in food packaging is increasing. All of this means that there are a large number of different packaging materials with different properties. The requirements for a packaging machine to be able to process all of the different packaging materials are also increasing. Depending on the type of packaging material, it can be a tough or brittle material. In order to be able to process packaging material with different properties with a shredding device such as the one mentioned above, different blades are required. If a packaging machine changes from one packaging material to another, for example because a different product is to be packaged, this means that it may be necessary to change the blades of the shredding device. Furthermore, plastic packaging films that contain fiber-based material or packaging material made of fiber-based material are very abrasive, which leads to increased wear on the blades of the shredding device. This means that the blades have to be replaced at shorter intervals.

Changing knives is time-consuming because the shredding device has to be opened, the old knives dismantled and the new knives installed and precisely adjusted. This in turn leads to unwanted downtimes of the packaging machine and thus to a loss of productivity.

EN 33 40 136 A1 , CN 103 657 808 A and EN 10 2013 200164 A1 reveal shredders or mixers, which are used in particular for shredding garden waste.

Task

Based on this prior art, it is the object of the present invention to provide a comminution device which reduces the frequency of time-consuming changeovers and to provide a method for operating the device.

Solution

This object is achieved by a packaging machine with the features of claim 1 or by a method for its operation according to independent claim 11. Advantageous developments of the invention are specified in the subclaims.
The device according to the invention for shredding strip-shaped material, in particular packaging material, comprises a housing with at least one feed opening for the strip-shaped material and a discharge opening for the material resulting therefrom, ie from the strip-shaped Material, shredded material, a knife holder which is mounted within the housing so as to be rotatable about an axis, at least one knife which is fastened to the knife holder, in particular detachably, and at least one counter knife which is fastened to the housing, in particular detachably, and a drive which is designed to rotate the knife holder. The device according to the invention is characterized in that a first direction of rotation and a second direction of rotation of the knife holder, opposite to the first direction of rotation, about the axis can be specified using the drive. In other words, this means that the drive can rotate the knife holder either clockwise or counterclockwise in order to shred the strip-shaped material fed to the device. The knife holder is configured to shred the strip-shaped material regardless of its direction of rotation, which makes it more suitable for versatile, in particular long-term use.

In an advantageous development of the device according to the invention, a cutting edge of the at least one knife forms a cutting plane that is perpendicular to the axis by rotating the knife holder about the axis. The cutting edge is understood to be the sharp part of the knife from which the cutting effect of the knife emanates.

It is advantageous if a cutting gap between the at least one knife and the at least one counter knife can be varied, in particular by adjusting the knife holder along the axis. The cutting gap refers to the minimum distance between the cutting edge of the knife and a cutting edge of the counter knife when they make the cut together. In order to cut reliably, it is important that the cutting gap is set correctly. Manufacturing inaccuracies in both the knives and counter knives as well as in the knife holder and other parts of the device can ensure that the cutting gap can be set correctly. In addition, extremely thin or extremely thick packaging materials can require a different cutting gap for an optimal cutting result.

It may be expedient for the knife and/or the counter knife to each have at least two cutting edges, preferably on opposite sides. It is irrelevant whether the knife and/or counter knife each have two cutting edges or whether two knives and/or two counter knives, each with one cutting edge, are attached in such a way that they correspond to one knife and/or counter knife with two cutting edges.

It is particularly advantageous if the cutting edge is at least partially straight, serrated, concave and/or convex. Different packaging materials can sometimes only be cut more reliably with different designs of the cutting edges. For example, a serrated or wavy cutting edge is particularly suitable for cutting thin and tough packaging materials. For example, brittle or thicker packaging materials can be cut optimally with straight cutting edges.

In a further development of the device according to the invention, the first cutting edge and the second cutting edge can be designed differently or identically.

It is particularly advantageous if two counter knives are arranged on the circumference of the at least one feed opening, in particular essentially symmetrically to an imaginary center line which divides the feed opening into two areas of equal area. The imaginary center line goes through the center of the feed opening, which corresponds to the geometric center of gravity of the feed opening, regardless of its geometry. The counter knives are arranged on the at least one feed opening in such a way that the cutting edge of the first counter knife engages with the first cutting edge of the at least one knife in order to be able to carry out a cutting process when the knife holder rotates in the first direction of rotation. And when the knife holder rotates in the second direction of rotation opposite to the first, the cutting edge of the second counter knife engages with the second cutting edge of the at least one knife in such a way that a cutting process can be carried out.

It is advantageous if the cutting edges of the counter knives are designed differently or the same. For example, but not restrictively, the knives and counter knives can be designed the same. This has the advantage of using identical parts and thus higher quantities and lower costs. If one cutting edge of a knife and counter knife is designed, for example, as a straight cutting edge and the other cutting edge as a serrated or wavy cutting edge, the knives and counter knives can be arranged in such a way that when the knife holder rotates in the first direction of rotation, the respective straight cutting edges of the knives and counter knives make a cut with each other and when the first direction of rotation is reversed in the second direction of rotation, the respective serrated or wavy cutting edges of the knives and counter knives make a cut with each other. This means that different packaging materials can be cut by reversing the direction of rotation. Time-consuming changeover work when changing from one packaging material to another packaging material can therefore be eliminated. If, however, a packaging machine only processes packaging materials that are processed with the same cutting edge design, the cutting edges of all knives and counter knives can be designed the same. If knives or counter knives become blunt, the direction of rotation can be reversed and the device can work again with a "fresh" set of cutting edges. This means that the maintenance interval for the knives can be doubled. which in turn leads to less downtime of the packaging machine and thus to improved productivity.

According to an advantageous development, the invention is characterized in that the at least one counter knife on the housing is height-adjustable and/or tiltable. This ensures, on the one hand, that even in the event of manufacturing inaccuracies, the cutting edges of the counter knives can always be aligned parallel to the cutting edges of the knives and, on the other hand, that the cutting gap is adjustable. It is conceivable that the set cutting gap between the knives and counter knives that engage when the knife holder rotates in the first direction of rotation is different from the cutting gap of the knives and counter knives that engage when the knife holder rotates in the second direction of rotation. Different cutting gaps can thus be set for different packaging materials by reversing the direction of rotation of the knife holder. This means that there is no need to readjust the knives and counter knives to one another when the packaging machine is converted from one packaging material to another packaging material that requires a different cutting gap for reliable processing. The conversion process on the device according to the invention can be carried out simply by selecting the direction of rotation. This increases the productivity of the packaging machine as downtime is avoided.

It is particularly advantageous if a negative pressure can be applied to the discharge opening. The negative pressure can be generated by a negative pressure generating device, for example a suction unit. The negative pressure and the resulting volume flow can feed the strip-shaped material through the feed opening into the housing and the shredded packaging material can be reliably discharged from the housing and fed into a waste container. In addition, the volume flow keeps the strip-shaped material "under tension", which improves the cutting result.

The invention also relates to a method for operating a device for shredding strip-shaped material, in particular packaging material. According to the invention, at least one knife holder is used for shredding the strip-shaped material, which is mounted so as to be rotatable in a first direction of rotation as well as in a second direction of rotation opposite to the first direction of rotation. In the invention, the strip-shaped material is shredded by means of a knife holder, regardless of whether it rotates in the first or in the second direction of rotation. With a rotating knife holder, which can cut the material fed to it in both the first and the opposite second direction of rotation, If strip-shaped material is shredded, this results in reduced service intervals for the shredding device, which means that the shredding process as a whole can be more sustainable and, in particular, more economical for the operation of a packaging machine.

A further development of the method according to the invention is characterized in that the rotation speed is changed by means of a control to adjust the size of the shredded material. The choice of the optimal rotation speed and thus also the optimal cutting speed can vary from packaging material to packaging material. The optimal rotation speed can therefore be selected for each packaging material. In addition, the size of the shredded material can be adjusted by selecting the rotation speed. The faster the rotation speed, the smaller the shredded material becomes. A highly shredded material has the advantage of low packing density, which means that more shredded material can be accommodated in a waste container because there are fewer hollow spaces between the individual pieces of material. This means that the interval at which the waste container has to be emptied can be increased, which leads to less downtime for the packaging machine and thus to higher productivity. If, on the other hand, the rotation speed is reduced, fewer cuts are made in the same time interval. This leads to less wear on the blades and thus to fewer maintenance intervals and less consumption of wearing parts and therefore to lower costs.

It is particularly advantageous if the control system stores operating parameters of the device, preferably the direction of rotation and/or the speed of rotation, in a data storage device, in particular in the control system. Operating parameters can be understood as all parameters that are necessary for operating the device. All operating parameters of the packaging machine or the food processing line, including those of the device, that are necessary for producing a specific product are stored in a recipe.

Packaging machines or food processing lines can be designed to produce different products. If the operator wants to switch from producing one product to another, he can change the recipe in the control system, i.e. by activating the recipe in the control system, and assign the necessary operating parameters to the entire packaging machine or food processing line, in particular specifying the direction of rotation for the knife holder on the shredding device. He therefore does not have to make the settings for each individual station or device of a packaging machine or food processing line separately, but can do this collectively.

The invention relates to a packaging machine, in particular a thermoforming packaging machine, which has the device according to the invention and to a packaging machine, in particular a thermoforming packaging machine, which is designed to carry out the method according to the above explanations.

The application also relates to a food processing line as described above.

Short description of the characters

Fig. 1

eine schematische Ansicht einer Tiefziehverpackungsmaschine;

Fig. 2

eine Schnittdarstellung einer Ausführungsform einer Vorrichtung zum Zerkleinern von streifenförmigem Material,

Fig.3

eine Schnittdarstellung der Ausführungsform der Vorrichtung,

Fig.4

eine Schnittdarstellung in Detailansicht der Ausführungsform der Vorrichtung,

Fig. 5

eine perspektivische Schnittdarstellung der Ausführungsform der Vorrichtung,

Fig. 6

eine perspektivische Schnittdarstellung der Ausführungsform der Vorrichtung, und

Fig. 7

eine schematische Darstellung einer Lebensmittelverarbeitungslinie.

An advantageous embodiment of the invention is described in more detail below with reference to a drawing. In detail:

Fig.1

a schematic view of a thermoforming packaging machine;

Fig. 2

a sectional view of an embodiment of a device for shredding strip-shaped material,

Fig.3

a sectional view of the embodiment of the device,

Fig.4

a sectional view in detail of the embodiment of the device,

Fig.5

a perspective sectional view of the embodiment of the device,

Fig.6

a perspective sectional view of the embodiment of the device, and

Fig.7

a schematic representation of a food processing line.

Detailed description

Figure 1 shows schematically an embodiment of a thermoforming packaging machine 100. The thermoforming packaging machine 100 has a forming station 101, a sealing station 102, a cross-cutting station 103 and a longitudinal cutting station 104, as well as a device 1 for shredding strip-shaped material 2. These are arranged in the named order in a transport direction T on a machine frame 105.

On the input side, a feed roller 106 is provided on the machine frame 105, from which a first film 107, the so-called bottom film, is pulled off. In the area of the sealing station 102, a second roller 108 is provided, from which a second film 109, the so-called top film, is pulled off. On the output side, a conveyor belt 110 is provided on the thermoforming packaging machine 100, with which finished, separated packages 111 are transported away. The thermoforming packaging machine 100 also has a feed device (not shown) which can grasp the bottom film 107 and, preferably in a main work cycle, transport it further intermittently in the transport direction T. The feed device can be implemented, for example, by laterally arranged transport chains, preferably clamp chains.

As shown in the embodiment shown, the forming station 101 is designed as a deep-drawing station. In this station, one or more packaging cavities 113 are formed in the first film 107 by deep-drawing.

The forming station 101 can be designed in such a way that several packaging troughs 113 can be formed next to one another in a direction perpendicular to the transport direction T. An insertion section 112 is provided behind the forming station 101 in the transport direction T. There, the packaging troughs 113 formed in the bottom film 107 are filled with products (not shown).

In the sealing station 102, an atmosphere in the packaging cavities 113 can be removed before sealing, for example by vacuuming and/or replaced by gas flushing with a replacement gas or with a replacement gas mixture. Or the sealing station 102 simply closes the packaging cavities 113 with the top film 109 without changing the atmosphere inside the packaging cavities 113.

The cross-cutting station 103 is designed to cut the bottom film 107 and the top film 109 in a direction transverse to the transport direction T between adjacent packaging troughs 113. The cross-cutting station 103 is configured such that the bottom film 107 is not divided over the entire width, but is not cut at least in one edge area. This enables a controlled further transport of the film composite by the feed device.

The longitudinal cutting station 104 is, as in the embodiment shown, designed as a rotating circular knife arrangement with which the bottom film 107 and the top film 109 are severed between adjacent packaging troughs 113 and at the lateral edge of the bottom film 107, whereby individual packages 111 are present behind the longitudinal cutting station 104. Initially, only so-called edge strips remain in the feed device, which are present as strip-shaped material 2. They are conveyed out of the feed device in the end region of the thermoforming packaging machine 100 and fed to the device 1.

The thermoforming packaging machine 100 also contains a controller 14, which has a data memory 15. The controller 14 is configured to control and/or monitor the processes taking place in the thermoforming packaging machine 100. In addition, a display and operating device 114 is preferably provided with operating elements (not shown) and is designed to visualize or influence process sequences in the packaging machine 100 for or by an operator.

In Figure 2 an embodiment of the device 1 according to the invention is shown in a sectional view in plan view. In the center of a housing 3 there is a rotatably mounted knife holder 7, which in this embodiment is equipped with two knives 9. The first direction of rotation r1 or the second direction of rotation r2, which is opposite to the first, can be specified. The knives 9 each have two Cutting edges 9a, 9b. The cutting edges 9a, 9b are aligned such that the cutting edges 9a are directed in the first rotation direction r1 and the cutting edges 9b are directed in the second rotation direction r2. In addition, the device 1 has a total of four counter knives 10, two of which are placed at each feed opening 4. The counter knives 10 are arranged at the feed opening 4 such that they are each symmetrical to a center line 12 which extends through a center point M of the feed opening 4. In the embodiment shown, the counter knives 10 have only one cutting edge 10a, 10b. A counter knife 10 with cutting edge 10a and a counter knife 10 with cutting edge 10b are placed at each feed opening 4. And arranged such that a strip-shaped material 2 (in Figure 5 shown) can be fed through the feed opening 4 and is crushed by the cutting edges 9a, 10a when the first rotation direction r1 is selected and is crushed by the cutting edges 9b, 10b when the second rotation direction r2 is selected.

In Figure 3 an embodiment of the device 1 according to the invention is shown in a sectional side view. The knife holder 7, which is mounted so as to be rotatable about an axis 8, is driven by a drive 11. The housing 3 has two feed openings 4 and one discharge opening 5.

In Figure 4 a detailed view of an area of the knives 9 and counter knives 10 of an embodiment of the device according to the invention is shown. A cutting plane 13 runs perpendicular to the axis 8 and through the cutting edges 9a, 9b of the knives 9. A cutting gap d is formed between the cutting plane 13 and the cutting edges 10a of the counter knives 10. The cutting gap d between the cutting edges 9a, 10a can differ from a cutting gap d' of the cutting edges 9b, 10b.

In Figure 5 is a sectional view of an embodiment of the device 1 according to the invention in a perspective view. Strip-shaped material 2 is fed through the feed opening 4 by means of negative pressure which is applied to the discharge opening 5. The strip-shaped material 2 is still held by the feed device and with each main work cycle of the thermoforming packaging machine a corresponding length of the strip-shaped material 2 is released. By rotating the knife holder 7 about the axis 8, the strip-shaped material 2 is cut into shredded material 6 by means of a cutting process using the knives 9 and the counter knives 10. The shredded material 6 is conveyed out through the discharge opening 5 by the negative pressure applied.

In Figure 6 is a sectional view of an embodiment of the device according to the invention. In this embodiment, the cutting edges 9a, 10a are designed as straight cutting edges and the cutting edges 9b, 10b as serrated cutting edges. When the knife holder 7 rotates in the first rotation direction r1, the cutting process is carried out by The cutting process is carried out by the interaction of the cutting edges 9a and the cutting edges 10a when the knife holder 7 rotates in the second rotation direction r2. The cutting process is carried out by the interaction of the cutting edges 9b and the cutting edges 10b. The cutting edges 9b, 10b in a serrated design are usually particularly suitable for cutting thin and tough packaging material, and the cutting edges 9a, 10a in a straight design are particularly suitable for cutting thick and brittle packaging material.

Figure 7 shows a schematic representation of an embodiment of a food processing line 600. It consists of a food slicing machine 200, a transport system 300, the thermoforming packaging machine 100, handling modules 400 and a final packaging system 500.

List of reference symbols

1

device

2

strip-shaped material

3

Housing

4

Feed opening

5

Discharge opening

6

shredded material

7

Knife holder

8

axis

9

Knife

9a, 9b

Cutting edge knives

10

Counter knife

10a, 10b

Cutting edges counter knife

11

drive

12

Centerline

13

Cutting plane

14

steering

15

Data storage

100

Thermoforming packaging machine

101

Forming station

102

Sealing station

103

Cross cutting station

104

Longitudinal cutting station

105

Machine frame

106

Feed roller

107

Bottom film

108

second role

109

Top film

110

Conveyor belt

111

Packaging

112

Insertion distance

113

Packaging tray

114

Display unit

d, d`

Cutting gap

r1

first rotation direction

r2

second direction of rotation

Claims (14)

1. Packaging machine, in particular deep-drawing packaging machine (100), comprising a device (1) for shredding strip-shaped material (2), in particular packaging material, wherein the device (1) comprises a housing (3) with at least one feed opening (4) for said strip-shaped material (2) and a discharge opening (5) for said material (6) shredded therefrom, a blade holder (7) which is mounted to be rotatable about an axis (8) within said housing (3), at least one blade (9) which is attached to said blade holder (7), in particular in a releasable manner, and at least one counter blade (10) which is attached to said housing (3), in particular in a releasable manner, as well as a drive (11) which is configured to rotate said blade holder (7) characterized in that a first direction of rotation (r1) and a second direction of rotation (r2), opposite to said first one, of said blade holder (7) about said axis (8) can be determined by way of the drive (11).
2. Packaging machine according to claim 1, characterized in that a cutting edge (9a, 9b) of said at least one blade (9) forms a cutting plane (13), which is disposed perpendicular to said axis (8), by a rotation of said blade holder (7) about said axis (8).
3. Packaging machine according to claim 1 or 2, characterized in that a cutting gap (d) between said at least one blade (9) and said at least one counter blade (10) is variable.
4. Packaging machine according to one of the preceding claims, characterized in that said blade (9) and/or said counter blade (10) each dispose of at least two cutting edges (9a, 9b, 10a, 10b), preferably on opposite sides.
5. Packaging machine according to claim 4, characterized in that said cutting edge (9a, 9b, 10a, 10b) is formed to be straight, serrated, concave, and/or convex, at least in sections.
6. Packaging machine according to claim 4 or 5, characterized in that said first cutting edge (9a, 10a) and said second cutting edge (9b, 10b) are configured to be different or identical.
7. Packaging machine according to one of the preceding claims, characterized in that two counter blades (10) are arranged on the circumference of said at least one feed opening (4), in particular substantially symmetrical to an imaginary center line (16) which divides said feed opening (4) into two regions of equal size.
8. Packaging machine according to claim 7, characterized in that said cutting edges 10a, 10b) of said counter blade (10) are configured to be different or identical.
9. Packaging machine according to one of the preceding claims, characterized in that said at least one counter blade (10) is attached to said housing to be adjustable in height and/or tiltable.
10. Packaging machine according to one of the preceding claims, characterized in that negative pressure is applicable to said discharge opening (5).
11. Method performed by a packaging machine, in particular deep-drawing packaging machine (100), for operating a device (1) for shredding strip-shaped material (2), in particular packaging material, characterized in that at least one blade holder (7) mounted to be rotatable in a first direction of rotation (r1) as well as in a second direction of rotation (r1) opposite to said first direction of rotation (r1) is employed by said device (1) for shredding said strip-shaped material (2).
12. Method according to claim 11, characterized in that the speed of rotation is changed by way of a control device (14) for adjusting the size of a shredded material (6).
13. Method according to claim 11 or 12, characterized in that said control device (14) stores operating parameters of said device (1), preferably said direction of rotation (r1, r2) and/or the speed of rotation, in a data memory (15), in particular of said control device (14).
14. Food processing line (600) comprising a packaging machine according to claim 1.

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