EP3831726A1 - Packing machine and method with folding function - Google Patents

Abstract

The invention relates to a packaging machine (1) with a sealing station (6) which comprises a lower tool part (11) with at least one shell receptacle (10) and an upper tool part (12) with at least one sealing device (16), the sealing device (16) being a Sealing element (17) which is configured to seal a cover film (8) onto a tray edge (30) of a packaging tray (5) provided in the tray receptacle (10) and has a holding element (18), the holding element (18) at least a passage (22) for a cutting element (19) for cutting the cover film (8) to size, the holding element (18) along an inner contour (23) of the passage (22) having several projections (20) for bending over one to form the shell edge ( 30) provided edge region (33) of the packaging tray (5). The invention also relates to a method for attaching a cover film (8) to a shell rim (30).

Description

The present invention relates to a packaging machine according to claim 1 and a method according to independent claim 12.

Tray sealing machines, also called traysealers in the following, are being used more and more frequently to produce packaging from paper fiber-based materials. In particular, for the provision and processing, especially for the forming and sealing, of cardboard trays, new requirements are placed on the traysealer technology.

A particular challenge is to fold over a half-finished, almost upright cardboard edge on cardboard trays for a victory process so that a cover film can be sealed onto it. It can be particularly problematic that the essentially upright carton edge can be crushed by a conventional sealing plate which, coming from above, presses on it with an almost vertical force.

The EP 2 783 990 A1 discloses a tray closing machine and a method for closing trays which have a plurality of sealing planes inclined to one another with a cover film.

EP 1 747 995 A1 discloses an apparatus and a method for gas-tight packaging of objects with a film material which fits closely to the objects. In order to cut the film material to size, the film material is clamped between a cutting frame and a spacer plate positioned underneath, in order to hold the film material taut in front of a cutting knife positioned above it.

The object of the invention is to provide a packaging machine and a method with which a tray edge can be aligned for a sealing process by means of simple structural technical means on a preferably paper fiber-based, provided packaging tray in order to be able to better seal a cover film to it.

This object is achieved by means of a packaging machine with the technical features of claim 1. Furthermore, this object is achieved by means of a method with the technical features of independent claim 12.

Advantageous further developments of the invention are specified in the respective subclaims.

The packaging machine according to the invention has a sealing station which comprises a lower tool part and an upper tool part. The lower tool part has a tray receptacle and the upper tool part comprises at least one sealing device which has a sealing element which is configured to seal a cover film onto a tray edge of a packaging tray provided in the tray receptacle. Furthermore, the sealing device has a holding element that provides at least one passage for a cutting element for cutting the cover film to size.

According to the invention, the holding element has a plurality of projections along an inner contour of the opening for bending over an edge region of the packaging tray provided for forming the tray edge. In this way, the holding element can function as a hold-down device for folding the shell edge in the direction of the horizontal, to which the cover film can be sealed better.

Accordingly, it can be avoided that the edge area, especially if it protrudes steeply upward, is crushed by the sealing element used during the sealing process, since a perpendicular force from the sealing element on the edge area is prevented. In other words, the holding element can hurry ahead of the sealing element in order to bend the shell edge in such a way that the sealing element can then press the cover film onto a shell edge that is lying flat under the action of a small amount of force.

Among other things, the invention prevents the cover film from adhering to the packaging tray too early, i.e. already adhering to the edge area at a point in time before it is bent over. Due to a separate construction of the holding element and the sealing element, the bending over of the tray edge and the sealing of the lid foil on the bent tray edge can be carried out one after the other in a chronological order so that undesired sticking, i.e. pre-sealing of the lid foil to the packaging tray can be avoided.

The sealing device used on the packaging machine according to the invention forms a multifunctional tool assembly, with the holding element provided on it being able to turn the tray edge over from a steep alignment for the sealing process and the separately formed sealing element for sealing the cover film on the tray edge, which is then flatter to the horizontal. The holding element and the sealing element can perform their respective functions one after the other in a common work cycle, making them particularly suitable for a time-optimized manufacturing process. Furthermore, the sealing device, including the holding element mounted thereon and the sealing element mounted thereon, has a compact design.

The packaging machine according to the invention is particularly advantageous when cutting and sealing sensitive lidding films, since the lidding film remains largely unstressed until the sealing process is carried out and only comes into contact with the depressed shell edge, after which it can then be optimally sealed.

It is advantageous if the projections are configured to deform the edge area of the packaging tray held in the tray receptacle, which is provided for forming the tray edge, from a first orientation into a second orientation with a reduced inclination relative to a horizontal bearing plane compared to the first orientation, in order to align the shell edge for the sealing process with a reduced inclination relative to a sealing surface of the sealing element. In the second orientation, the shell edge can enclose an angle of less than 60 °, in particular less than 45 °, with the horizontal at its kink.

In particular, the projections can be designed to bend the edge area of the packaging tray provided into the second orientation before the cover film comes into contact with the tray edge, i.e. at the bent edge area of the packaging tray. Since the projections first bend the edge area before the cover film makes contact with it, pre-sealing, that is, undesired adhesion of the cover film to the packaging tray, can be avoided, which leads to better quality packaging results.

One variant provides that the cutting element is a knife with a geometry corresponding to the inner contour of the passage in the horizontal projection plane. In particular, the knife can alternately have both outer knife sections and inwardly directed knife sections in the horizontal projection plane corresponding to the inner contour of the passage.

The sealing element preferably forms a plurality of sealing webs which, during the sealing process, can at least partially be retracted along the inner contour of the passage into recesses left free between the projections in order to produce a sealing seam which is interrupted several times at the edge of the shell according to the number of projections. Such a sealing seam produced only in sections is particularly useful for closing cardboard trays with fruit or vegetables contained therein.

Viewed in the horizontal projection plane, the projections and the knife resting on them can run in such a way that they protrude into the interrupted sections of the sealing seam to be produced, so that the thus cut and sealed cover film provides a corrugated border on the shell edge.

One embodiment provides that the respective projections formed along the inner contour of the passage have a bevel, by means of which the edge area of the packaging tray held within the tray receptacle, provided for forming the tray edge, can be folded outwards in the direction of the horizontal storage plane. Because of the incline, the respective projections can immerse themselves perfectly in the packaging tray facing them, in order to reshape the tray edge to the horizontal bearing plane without applying great force to the outside. In other words, the incline and the edge area meet in such a way that the edge area gently drifts outwards along the incline due to the reduced application of force, in order to be folded over in the direction of the horizontal.

It is advantageous if the respective inclines in the vertical projection plane have an inclination between 10 ° and 60 °, in particular between 15 ° and 45 °, relative to the horizontal. The edge region, which protrudes in the original orientation, usually essentially perpendicularly on the packaging tray, can come into engagement at the bevels of the projections in order to fold the tray edge in such a way that only slight buckling forces act on it. In this way, crushing of the edge area can be effectively avoided. Furthermore, by gently folding over the edge area, a particularly neat bend can be produced at the transition to the side walls of the packaging tray.

The holding element is preferably designed in the form of a frame. The holding element can thus be produced particularly well in a lightweight construction. Because the holding element is in the form of a frame, both the cutting element and the sealing element can be passed through in a compact design within the frame in order to cut and seal the cover film. In addition, the tools that can be guided through within the frame enable the cover film to be cut and sealed precisely.

One embodiment provides that the holding element is made from a heat-insulating material, in particular from a heat-insulating plastic. This makes it possible to largely prevent heat transfer from the sealing element stored in the vicinity to the holding element. This has the advantage that the cover film, which is seated in some areas on the holding element, is not heated undesirably during the folding over of the edge region of the packaging tray and, after it has been cut to size, when it comes into contact with the folded over Shell edge adheres too early, before it is brought into a desired final orientation. If the holding element is made of plastic, the total weight of the sealing device can be reduced and the holding element can be manufactured inexpensively. In particular, this allows the heat transfer to the products to be packaged, for example fruit or vegetables, to be curbed to a greater extent. Another embodiment provides that the holding element is made of aluminum or steel. The holding element preferably assumes the temperature of the water-cooled, closed upper tool part.

A preferred variant provides that the cutting element is coupled to the movement of the sealing element or is mounted adjustably by means of its own drive in order to cut the cover film to size. The coupled drive version in particular offers an expedient, cost-optimized solution. The separate, i.e. decoupled drive variant could be advantageous in order to carry out the cutting of the cover film in terms of time before the sealing element is lowered to seal the cut cover film, whereby the approach of the sealing element to the cover film can be delayed in order to avoid preheating of the cover film.

The packaging machine is preferably designed in the form of a traysealer for closing paper fiber-based packaging trays. For flexible use, the sealing device used on the traysealer can be available as an interchangeable kit, so that the traysealer can easily be converted to produce different packaging formats.

The invention also relates to a method for attaching a cover film to a tray edge of a packaging tray, for example a cardboard tray, provided in a tray receptacle within a sealing station. According to the invention it is provided that a holding element, which has at least one passage for a cutting element for cutting the cover film, bends over an edge region of the packaging tray provided for forming the tray edge by means of projections formed thereon along an inner contour of the passage for a sealing process.

The kinking of the tray edge and the sealing of the lid foil on it are carried out in procedural terms, in particular in separate, successive steps by means of the sealing device, whereby a tray edge is formed precisely when sealing cardboard trays and an undesired adhesion of the lid foil occurs at one point in time in which the shell edge is not yet aligned, can be avoided. When the invention In a method, the holding element on the sealing device can work as a leading tool relative to the sealing element, in order to first bend the shell edge into the flat orientation before the cover film is then sealed onto the shell edge.

In the method according to the invention, the projections formed on the holding element can come into engagement at the edge region of the packaging tray, which may be almost perpendicularly aligned, and fold this over to form the tray edge before the sealing element comes into contact with the cover film and / or with the edge region. The projections make it possible for the edge area to be folded over at least temporarily prior to the sealing of the cover film, preferably in completely separate work steps one after the other.

In the method according to the invention, because of their separate construction and operation, the holding element as a cold forming tool for bending the tray edge and the sealing element as a heat sealing tool for sealing the cover film on the tray edge can work together excellently without damaging the packaging materials or the products contained therein, for example fruit or vegetables Packaging process are influenced.

It is advantageous if the projections bend the edge area of the packaging tray provided in the tray receptacle, which is provided for forming the tray edge, from a first orientation into a second orientation with a reduced inclination relative to a horizontal bearing plane compared to the first orientation, in order to avoid the tray edge for the Orient the sealing process with a reduced tendency relative to a sealing surface of a sealing element. The pressing of the cover film by means of the sealing element is thereby possible on the prefabricated shell edge with reduced application of force, which leads to a better sealing quality.

In particular, the edge region can be folded over into the second orientation without engagement of the sealing element, i.e. exclusively using the holding element, in particular the projections formed thereon. This can prevent undesired pre-sealing of the cover film on the packaging tray. The sealing element can be used to completely fold the shell edge out of the second orientation, for example to press it into a horizontal orientation.

A preferred variant provides that the projections at least partially dip into an open area of the packaging tray facing them, whereby the for forming the Shell edge provided edge region of the packaging tray received within the tray receptacle along a slope formed on the respective projection outward, in the direction of the horizontal storage plane. The immersion of the projections in the open area of the packaging tray facing them, the initial abutment of the edge area on the respective inclines, as well as the sideways drifting of the edge area along the inclines resulting from further lowering of the holding element in order to fold the edge area further down towards the horizontal , takes place with little force on the edge area, even if it was originally shaped almost vertically.

One embodiment provides that, during the sealing process, several sealing bars move at least partially into recesses left free between the projections, i.e. indentations along the inner contour of the passage, in order to produce a corresponding number of projections interrupted multiple times on the shell edge. In the horizontal projection plane, the sealing webs formed on the sealing element can alternate with the projections formed on the holding element, whereby a sealing seam with interruptions is produced on the edge of the tray, which is useful, for example, for packing fruit and vegetables.

Fig. 1

eine Verpackungsmaschine, die in Form eines Traysealers vorliegt,

Fig. 2A

eine schematische Darstellung einer Siegeleinrichtung,

Fig. 2B

eine perspektivische Darstellung der in Figur 2A gezeigten Siegeleinrichtung,

Fig. 2C

eine weitere perspektivische Darstellung der in Figur 2A gezeigten Siegeleinrichtung,

Fig. 3

eine Schnittdarstellung in horizontaler Projektionsebene der Siegeleinrichtung,

Fig. 4

ein hergestelltes Verpackungsprodukt mit unterbrochener Siegelnaht, und

Fig. 5A bis 5F

die Arbeitsweise der Siegeleinrichtung in schematischer Darstellung.

Embodiments of the invention are explained in more detail with reference to the following figures. Show it

Fig. 1

a packaging machine in the form of a traysealer,

Figure 2A

a schematic representation of a sealing device,

Figure 2B

a perspective view of the in Figure 2A sealing device shown,

Figure 2C

a further perspective view of the in Figure 2A sealing device shown,

Fig. 3

a sectional view in the horizontal projection plane of the sealing device,

Fig. 4

a manufactured packaging product with an interrupted sealing seam, and

Figures 5A through 5F

the operation of the sealing device in a schematic representation.

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

Figure 1 shows a packaging machine 1. The packaging machine 1 is designed in the form of a traysealer 2. The traysealer 2 comprises a machine frame 3 and a feed belt 4, which is arranged on the input side on the machine frame 3 and which is configured to provide packaging trays 5 for a sealing station 6 provided on the traysealer 2. The sealing station 6 is in Figure 1 associated with a gripper 7 which is designed to pick up packaging trays 5 from the feed belt 4 and to transport them into the sealing station 6. The packaging trays 5 are here as cardboard trays.

By means of a sealing process S carried out in the sealing station 6, a web of material 8, for example a cover film, can be at least partially sealed within the sealing station 6 with the packaging trays 5 received therein. The web of material 8 is fed to the sealing station 6 by means of an unwinding device 9.

To accommodate the packaging trays 5 within the sealing station 6, a tray holder 10 is provided. The shell receptacle 10 belongs to a lower tool part 11 of the sealing station 6. Furthermore, the sealing station 6 has an upper tool part 12 which is mounted such that it can be brought together with the lower tool part 11 in order to provide its sealing chamber 40, which is preferably hermetically sealed, for the sealing process (see Fig Figure 5C ) to include.

Following a sealing process S carried out within the sealing station 6, the then sealed packaging trays 5 can be transported by means of the gripper 7 out of the tray receptacle 5 onto a discharge belt 13 located downstream in the production direction R. To control the in Figure 1 A control module 15 is attached to a machine structure 14 with the traysealer 2 shown, with which an operator can control the manufacturing process on the traysealer 2.

Figure 2A shows a schematic side view of a sealing device 16. The sealing device 16 comprises a sealing element 17 and a holding element 18 positioned below it. A cutting element 19 is arranged around the sealing element 16. Also shows Figure 2A that the holding element 18 has a plurality of projections 20.

Figure 2B shows the sealing device 16 from Figure 2A in a different perspective. Figure 2B illustrates that the holding element 18 is in the form of a frame 21. The projections 20 of the holding element 18 protrude in regions into a passage 22 formed on the frame 21. The passage 22 has an inner contour 23 which enables both the sealing element 17 and the cutting element 19 to be moved through the passage 22 first to cut the cover sheet 8 and then to seal the cover sheet 8 to the packaging tray 5.

Figure 2B further shows that the projections 20 each have a slope 24. The holding element 18, in particular its projections 20, including the respective bevels 24 formed thereon, can be used to deform the packaging tray 5. This is explained in more detail below in connection with the Figures 5A to 5F described.

Figure 2B shows that in the radial direction, in a sequence from the inside to the outside, the sealing element 17, the cutting element 19 and the holding element 18 are designed to interlock at least in some areas, which favors a compact design of the sealing device 16. This interlocking geometry of the respective tools used on the sealing device 16 is shown in FIG Figure 2C further illustrated.

Figure 2C shows the sealing device 16 in a perspective from below. Along the inner contour 23 of the frame 21, a plurality of projections 20 alternate with recesses 25 in between, which are formed in the form of indentations on the frame 21. The sealing element 17 forms a plurality of sealing webs 26 protruding downward. Also shows Figure 2C that the cutting element 19 is present as an endless knife 27. The knife 27 essentially has a corresponding extension with respect to the inner contour 23 of the holding element 18 designed as a frame 21.

In Figure 2C it can be seen that the respective sealing webs 26 as well as sections of the knife 27 adjoining them in the radial viewing direction are assigned to the respective recesses 25 of the frame 21. This makes it possible to have an interrupted sealing seam 29 (see FIG Fig. 4 ) to produce.

The Figures 2A to 2C also show that the sealing element 17 essentially has a frame shape 28. In particular, however, illustrate the Figures 2A to 2C that the sealing device 16 in a compact design forms several tools, namely the sealing element 17, the holding element 18 and the cutting element 19 lying close to one another and interlocking in a radial extension.

Figure 3 shows a horizontal sectional view of the sealing device 23. The sealing webs 26 of the sealing element 17 are arranged in the respective recesses 25 of the holding element 18. The one further in Figure 3 For a better understanding of the mode of operation of the sealing device 23, the shell edge 30 of the packaging shell 5 shown only partially pressing sealing webs generate the interrupted sealing seam 29 on the shell edge 30 of the packaging shell 5 (see also Fig. 4 ).

Next shows Figure 3 that the knife 27 lies adjacent to the inner contour 23 of the frame 21, that is to say closely adjacent, but possibly without contact. The projections 20 and adjoining sections of the knife 27 extend between the respective sealing webs 26 immersed in the recesses 25. Preferably, the sealing element 17, including the sealing webs 28, and the knife 27 are coupled into and out of the passage 22 of the holding element 18 moved out in order to cut the cover sheet 8 to size and to seal it in sections to the shell edge 30 of the packaging shell 5. In preparation for this, the bending of the shell edge 30 on the packaging shell 5 is carried out by means of the projections 20, in particular by means of the bevels 24 formed thereon.

Figure 4 shows a plan view of a schematic packaging geometry, as it is based on the sealing device 16 from Figure 3 can be produced.

The interrupted sealing seam 29, which can be produced by means of the sealing webs 26 formed on the sealing element 17, is produced on the shell edge 30. Figure 4 thus shows that the cover film 8 adheres in a heat-sealed manner to the shell edge 30 of the packaging shell 5 only in some areas. Such a packaging geometry is suitable, for example, for packaging fruit and vegetables, in particular when the packaging tray 5 is made from a paper fiber-based material.

In Figure 4 it can also be seen that a border 31 of the cover film 8 has a wave shape, which relates to the geometry of the knife 27 Figure 3 is traceable.

The Figures 5A to 5F show, in a schematic sequence, the mode of operation of the sealing station 6 when forming the tray edge 30, when cutting the cover sheet 8 and when sealing the cut cover sheet 8 to the bent tray edge 30.

In the Figures 5A to 5F the tray receptacle 10 has a base 50, the packaging tray 5 being seated on the base 50 with a packaging base formed thereon.

In the Figure 5A the sealing station 6 is in an open state 32. The packaging tray 5 is positioned within the tray receptacle 10 of the lower tool part 11. On the packaging tray 5, an edge region 33 is formed which is oriented steeply, almost vertically upwards. In Figure 5A the cover film 8 is positioned above the holding element 18. The sealing element 17 and the cutting element 19 are located above the cover film 8.

A bending edge 34 is formed on the tray receptacle 10 adjacent to the edge region 33 of the packaging tray 5. At the bending edge 34, the originally almost vertically aligned edge area 33 can be folded over, which is shown in the following Figure 5B is explained in more detail.

Figure 5B now shows the upper tool part 12, including the sealing device 16 stored therein, in a position displaced further downwards. The projections 20 dip into an open area 38 of the packaging tray 5, as a result of which they grip the edge area 33 of the packaging tray 5 and bend it outwards towards the horizontal storage plane L. The bending edge 34 supports the bending process and ensures, in particular, that the edge region 33 can be bent over properly in the direction of the horizontal bearing plane L, that is to say that a straight kink is produced.

Figure 5C shows the sealing station 6 in a closed state 35. In comparison to FIG Figure 5A , in which the edge region 33 of the packaging tray 5 was still in a first orientation 36 is now shown in FIG Figure 5C the edge region 33 is bent over by means of the projections 20 in such a way that it is in a second orientation 37 in which it is present with a reduced inclination α relative to the horizontal bearing plane L. In the second orientation 37, the edge region 33 is now present as a half-finished, already fairly flat shell edge 30, so that the sealing process S is better possible.

Figure 5D shows the cutting of the cover sheet 8. The cutting element 19 is now out of its in Figure 5C The position shown is adjusted further down, whereby it dips into the tensioned cover sheet 8 and cuts it.

Figure 5E now shows how the already folded edge area 33 is bent down further out of its second orientation 37, which is done by the sealing element 17. In Figure 5E the sealing element 17 is in a further downwardly displaced position compared to Figure 5D as a result of which it presses from above onto the shell edge 30, ie the edge region 33 present in the second orientation 37, by means of the sealing webs 26 formed thereon. A further lowering of the sealing element 17 has the effect that the shell edge 30 is pressed down onto the bending edge 34, which Figure 5F shows.

Figure 5F shows the sealing of the cut-to-size cover film 8 on the shell edge 30 by means of the sealing webs 26 pressing on the shell receptacle 10. The sealing webs 26 have pressed the edge area 33, which is in its second orientation 37, against the bevels 28, further down until the shell edge 30 rests comes on the bending edge 34.

The 36 in Figure 5A The edge region 33 of the packaging tray 5, which is shown almost vertically upwards, is moved into the according to FIG Figure 5C The second alignment 37 shown is folded over so that the lowered sealing element 17, which then comes from above, no longer presses the edge area 33 with a vertical force, but instead presses it out Figure 5E because of its flat orientation, it bends more gently downwards.

The figures described above therefore make it clear that the holding element 18 is configured to fold the originally unbent edge area 33 of the packaging tray 5 prior to the sealing process S so that it is in a second orientation 37 for the sealing process S that is flat relative to the horizontal storage plane L so that the sealing element 17 coming from above can press it down further with little force to avoid squeezing the shell edge. The principle according to the invention also makes it possible that, due to the bending process preceding the sealing process S, by means of the holding element 18, a pre-sealing of the cover film 8 on the packaging tray 5 can be avoided.

Claims (15)

Packaging machine (1) with a sealing station (6) which comprises a lower tool part (11) with at least one shell receptacle (10) and an upper tool part (12) with at least one sealing device (16), the sealing device (16) having a sealing element (17) , which is configured to seal a cover film (8) onto a tray edge (30) of a packaging tray (5) provided in the tray receptacle (10) and has a holding element (18), the holding element (18) having at least one passage (22 ) provides for a cutting element (19) for cutting the cover film (8) to size, characterized in that the holding element (18) along an inner contour (23) of the passage (22) provides a plurality of projections (20) for bending over one to form the shell edge (30 ) provided edge region (33) of the packaging tray (5). Packaging machine according to Claim 1, characterized in that the projections (20) are configured to move the edge region (33) of the packaging tray (5) held in the tray receptacle (10), which is provided for forming the tray edge (30), from a first orientation (36). out into a second orientation (37) with a reduced inclination (a) relative to a horizontal bearing plane (L) in comparison to the first orientation (36) in order to deform the tray edge (30) for the sealing process (S) with a reduced inclination ( a) to be aligned relative to a sealing surface of the sealing element (17). Packaging machine according to claim 1 or 2, characterized in that the cutting element (19) is a knife (27) with a geometry corresponding to the inner contour (23) of the passage (22) in the horizontal projection plane. Packaging machine according to one of the preceding claims, characterized in that the sealing element (17) has several sealing webs (26) which, during the sealing process (S), are at least partially in recesses (25) left free between the projections (20) along the inner contour (23) of the Passage (22) can be retracted in order to produce a sealing seam (29) which is interrupted several times according to the number of projections (20) on the shell edge (30). Packaging machine according to one of the preceding claims, characterized in that the respective projections (20) formed along the inner contour (23) of the passage (22) have a slope (24) by means of which the for forming the Shell edge (30) provided edge region (33) of the packaging tray (5) held within the tray receptacle (10) can be folded outwards in the direction of the horizontal storage plane (L). Packaging machine according to Claim 5, characterized in that the respective inclines (24) in the vertical projection plane have an inclination between 10 ° and 60 °, in particular between 15 ° and 45 °, relative to the horizontal. Packaging machine according to one of the preceding claims, characterized in that the holding element (18) is designed in the form of a frame (21). Packaging machine according to one of the preceding claims, characterized in that the holding element (18) is made from a heat-insulating material. Packaging machine according to one of the preceding claims, characterized in that the cutting element (19) is coupled to the movement of the sealing element (17) or is mounted adjustably by means of its own drive in order to cut the cover film (8). Packaging machine according to one of the preceding claims, characterized in that the packaging machine (1) is designed in the form of a traysealer (2) for closing paper fiber-based packaging trays (5). Packaging machine according to one of the preceding claims, characterized in that the sealing element (17) and the cutting element (19) are available as an exchangeable, interchangeable kit. Method for attaching a cover film (8) to a tray edge (30) of a packaging tray (5) provided within a sealing station (6) in a tray receptacle (10), characterized in that a holding element (18), which has at least one passage (22) for a cutting element (19) for cutting the cover film (8) to size, by means of projections (20) formed thereon along an inner contour (23) of the passage (22) for a sealing process (S) an edge region (30) provided for forming the shell edge (30). 33) of the packaging tray (5). The method according to claim 12, characterized in that the projections (20) move the edge region (33) of the packaging tray (5) held in the tray receptacle (10) provided for forming the tray edge (30) from a first orientation (36) into a second Bend alignment (37) with a reduced inclination (a) relative to a horizontal bearing plane (L) compared to the first alignment (36) in order to bend the tray edge (30) for the sealing process (S) with a reduced inclination (a) relative to a Align the sealing surface of a sealing element (17). Method according to claim 12 or 13, characterized in that the projections (20) at least partially dip into an open area (38) of the packaging tray (5) facing them, whereby the edge area (33) provided for forming the tray edge (30) becomes the inside the tray receptacle (10) received packaging tray (5) along a slope (24) formed on the respective projection (20) outwards, in the direction of the horizontal storage plane (L). Method according to one of the preceding claims 12 to 14, characterized in that several sealing webs (26) move at least partially into recesses (25) left between the projections (20) along the inner contour (23) of the passage (22) during the sealing process (S) in order to produce a sealing seam (29) which is interrupted several times according to the number of projections (20) on the shell edge (30).

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