Patent Application
20210292071
This application claims priority under 35 USC 119 of German Application No. DE 10 2020 107 324.0, filed on Mar. 17, 2020, the disclosure of which is herein incorporated by reference.
The invention is directed to a deep drawing sheet packaging with a packaging body comprising a shell and a cover film, wherein the cover film closes the shell, and the shell is formed from a deep drawing sheet.
Deep drawing sheet packaging of this kind is commonly used for the packaging of foods, medical products or the like. The packaged products are protected by the shell which is formed from a deep drawing sheet and can be presented to the user in an attractive manner. After the deep drawing sheet packaging is opened, it is possible to remove the products.
The shell and the cover film form a packaging body which is formed in such a way that a reliable closure is ensured and the final consumer can easily open the tear-open package. This is normally carried out by means of a closure seam which is formed to be correspondingly detachable, connects the shell and cover film to one another and securely closes the packaging body. In order to open the deep drawing sheet packaging, an unconnected portion arranged outside of the closure seam normally remains at one corner of the cover film. This portion can be grasped by the final consumer, and the cover film can be removed from the shell proceeding from this portion by detaching the closure seam. Such detachable seams are also known as peelable seams. In contrast, non-peelable seams can no longer be opened, and with deep drawing sheet packaging formed in this way it is only possible to remove the products packaged therein by destroying the cover film.
In generic deep drawing sheet packaging, the deep drawing sheet is formed appreciably stiffer than the cover film so that the shell of the deep drawing sheet packaging imparts a certain degree of stability, and the cover film lies flat or substantially flat on the shell and has only a two-dimensional structure. A laminate composite with an inner film of polyethylene (PE) and at least one outer film of polyethylene terephthalate (PET) is usually used as material for the cover film. The inner film of polyethylene has very good sealing properties so that the cover film can be sealed over the inner film with the shell by heat sealing. In heat sealing, a connection is carried out without an additional adhesive layer, the material of the shell and the material of the cover film both being slightly melted, and a bonding connection is made between the two layers.
Moreover, with a laminate composite of this kind, a print layer can be provided. This print layer is preferably arranged between the inner film and the outer film so that it is protected both inwardly and outwardly by the adjoining layers, and a high-quality visual appearance is accordingly ensured over a long time period. At least the outer film is transparent so that the print layer remains visible from the outside. The print layer can be printed both on the inner film and on the outer film. If necessary, the film to be printed can undergo a corona treatment beforehand so as to facilitate adhesion for the print layer. Beyond this, further film layers can also be provided in addition to the inner film and outer film.
Deep drawing sheet packaging of this kind is characterized by an especially high-quality visual appearance and excellent functional characteristics. However, due to the different variety of materials, plastics recycling is only possible to a very limited extent because a separation of the materials and, therefore, a single-stream material recycling is scarcely possible. By “material recycling” is meant recycling within a main class of plastics or preferably within a class of transparent polymers. In view of the foregoing, known deep drawing packagings as single-use articles cannot usually be recycled easily after use to yield useful materials and is usually consigned to garbage incineration so that at least thermal reclamation is still possible.
On the other hand, in single-stream form, the plastic waste can be materially recycled together, but the printing ink on the print layer which is often provided on the cover film then also interferes with or even prevents collective recycling because a transparent recyclate cannot be formed. For this reason, there is always an effort to provide a majority of packaging in single-stream, particularly with print only in a negligible area. But at the same time visually appealing packaging should be formed precisely for advertising purposes so that print cannot entirely be eliminated. In particular, the final consumer must be given information about the packaged product, any ingredients and storability data.
In view of the foregoing, it is the object of the present invention to improve the possibilities for the use and design of generic deep drawing sheet packaging and, in particular, to improve recyclability.
Therefore, the subject matter of the invention and the solution to the above-stated object is a deep drawing sheet packaging having a packaging body comprising a shell and a cover film, wherein the cover film closes the shell and the shell is formed from a deep drawing sheet, wherein a printed material portion is arranged on the packaging body and attached to the packaging body merely at a portion of a surrounding edge by an attachment seam.
Accordingly, proceeding from a deep drawing sheet packaging of the type described in the introduction, a printed material portion is arranged on the packaging body and attached to the packaging body merely at a portion of a surrounding edge by an attachment seam. The term “attachment seam” does not refer to any specific construction. Rather, any planar fastening, e.g., heat-seal seams or adhesive seams, may be designated as attachment seam.
The surrounding edge refers to a portion of the printed material portion. Since, accordingly, a fastening can only be carried out at the surrounding edge, regions between the edge rest unattached on the packaging body. These unattached portions lie flat on the packaging body and do not form a functional space, e.g., for receiving objects of some kind. Rather, the attachment seam extends only over a small percentage of the surface area of the printed material portion so that the printed material portion can be removed as completely and as easily as possible.
The attachment seam preferably extends over less than 20 percent, particularly preferably less than 15 percent, of the area of the unprinted material portion. Accordingly, the invention differs from label solutions in which labels of high-density polyethylene (HDPE), for example, are fastened to the packaging body via an adhesive area covering the entire back surface of the label.
By means of the printed material portion, the print can preferably be arranged entirely on the additional material portion which then contains all essential information, e.g., about the packaging contents, the ingredients of the packaged products, storability data, advertising information, or the like. Therefore, it is not absolutely necessary that the packaging body also have print, and the packaging body can be recycled in a simple manner and with a high yield of recovered material.
A comparable solution is known, e.g., from EP 3 594 144 A1. But, in contrast to the present invention, an additional printed material portion is provided on a film packaging which does not provide any separation of the individual front walls from one another compared to a deep drawing sheet packaging. Thus the packaging body described in the above-cited reference already forms a structural unit in which the material portion is also preferably fixedly and non-peelably connected to the front walls so that perforations are provided for a removal of this material portion. In contrast, as already mentioned in the introduction, a deep drawing sheet packaging is preferably provided with a peelable connection between the cover film and the shell so that, when arranged on the cover film, the printed material portion is arranged on a component part of the packaging body which is removed from the shell in any case in the process of opening. Accordingly, the invention consciously takes into account the fact that when the individual attachment seams and closure seams are not carefully designed an unintentional tearing of the deep drawing sheet packaging can take place in order, in return, to substantially simplify recycling of the packaging.
Since the attachment seam does not extend along the entire surrounding edge, the material portion can also be gripped from behind in a simple manner so that it is possible to remove the material portion easily from the packaging body. To this end, the attachment seam is preferably formed such that it can be separated relatively easily. A peelable fastening of this kind can be adjusted, for example, by precisely selected parameters, whereby the material portion is fastened so firmly to the packaging body on the one hand that an unwanted separation is prevented as far as possible and, on the other hand, the material portion can be detached without great effort by purposely grasping it from behind. This can be made possible, for example, by the type of attachment as well as by the quantity of attachment points. Accordingly, it is provided that the attachment seam can be formed either continuously or discontinuously from a plurality of attachment points.
Alternatively, the material portion can also be attached to the packaging body with a non-detachable or non-peelable attachment seam, and the printed material portion then preferably has weakened material, e.g., in the form of perforations, adjacent to the attachment seam so that the material portion can then also be removed to a great extent.
According to a preferred embodiment, the attachment seam extends over between 5 percent and 80 percent, preferably between 10 percent to 60 percent, particularly preferably between 15 percent and 50 percent, of the surrounding edge. Correspondingly, the edge has an unconnected portion of between 20 percent and 95 percent, preferably between 40 percent and 90 percent, particularly preferably between 50 percent and 85 percent, so that the printed material portion can be grasped from behind along the unconnected portion of the surrounding edge and removed.
A preferred embodiment of the invention provides that the printed material portion is arranged on the cover film, and the material portion only covers between 30 percent and 80 percent, preferably between 40 percent and 70 percent, of the cover film. It will be appreciated that it also lies within the scope of the invention that the printed material portion rests on the shell or on side walls of the shell. However, arranging on the cover film allows a considerably more attractive visual appearance because the material portion then lies flat and the information printed on it is more visible. Further, deep drawing sheet packagings are generally stacked one on top of another on a shelf, so that the cover film faces upward, and the printed material portion is accordingly directly visible from the outside and the information printed thereon can be read. However, insofar as the printed material portion is arranged on the deep drawing sheet of the shell, the indicated values relate to a projected surface area of the shell which usually corresponds to the surface area of the cover film.
An embodiment in which the cover film or deep drawing sheet is not covered over the entire surface is expedient particularly when the cover film and/or the deep drawing sheet are formed transparent according to a further development. In this case, it is ensured in spite of the use of an additional printed material portion that it is possible to see into the deep drawing sheet packaging so that, for example, the final consumer can immediately identify the type of packaged product in question and not rely exclusively on the information on the printed material portion. Although both shell and cover film are formed transparent according to a preferred embodiment, it is generally sufficient that only the cover film or the deep drawing sheet is formed transparent. Further, the printed material portion can also be formed transparent outside of the print.
According to an alternative embodiment form, the printed material portion is likewise arranged on the cover film and covers the entire surface thereof, and the printed material portion has print which covers only between 30 percent and 80 percent, preferably between 40 percent and 70 percent, of the material portion. An embodiment of this kind is also particularly useful when at least the cover film and the printed material portion are formed transparent, where as regards the printed material portion this relates only to the unprinted portions. Accordingly, it is still possible to see into the deep drawing sheet packaging even with full surface area arrangement.
According to a preferred further development of the invention, the deep drawing sheet and/or the cover film are formed to be heat-sealable at an outer side of the packaging so that the attachment seam can be formed as a heat-seal seam, preferably as a detachable heat-seal seam. However, the deep drawing sheet and the cover film are preferably configured to be heat-sealable at least at one inner side of the packaging, and the shell and cover film can then be connected to one another via a closure seam running along a surrounding side edge of the packaging body, which closure seam is also formed as heat-seal seam.
In such a case, both the attachment seam and the closure seam can be formed in only one sealing process when closing the deep drawing sheet packaging, so that the process steps for producing the deep drawing sheet packaging are substantially reduced in particular. However, it must be taken into account in this regard that in such a case the cover film, the deep drawing sheet and the printed material portion are at least partially produced from a sealable material, or at least the film layers adjoining the heat-seal seams are produced from such sealable material. In this connection, polyolefins, e.g., polyethylene (PE) or polypropylene (PP), are particularly suitable. However, such sealable materials generally have only a poor printability so that the printed surface of the material portion must either be formed from another material or must be subjected to a so-called corona treatment which substantially increases printability. However, a corona treatment of this kind must be omitted in the region of the heat-seal seams because while printability is enhanced, sealability is reduced at the same time.
According to an alternative embodiment, the attachment seam can also be formed as an adhesive seam so that the printed material portion is then attached to the packaging body, particularly to the cover film, by incorporating an adhesive layer. This has the advantage that materials which are not capable of heat sealing can also be attached to the packaging body. The packaging body itself is nevertheless still preferably formed to be heat-sealable so that the closure seam can be formed as heat-seal seam and the fastening can be formed as adhesive seam.
Regarding the configuration of the closure seam, a detachable or peelable closure seam or heat-seal seam is particularly suitable and, according to a particularly preferred embodiment form, the closure seam has a safety portion in which the closure seam is formed permanent, and the closure seam is formed detachable outside of the safety portion. In this way, the deep drawing sheet packaging can be opened easily by means of the detachable portion, while the safety portion simultaneously ensures that the cover film continues to adhere to the shell even in an opened state. Accordingly, the entire packaging body can be materially recycled together, which is particularly useful especially in a single-stream-configured packaging body. Therefore, according to an advantageous embodiment, the attachment seam is formed so as to be completely detachable and the closure seam is formed to be at least partially detachable.
The circumferential side edge preferably extends at least partially along a circumferential side edge of the packaging body, and the attachment seam is formed at least partially congruent with the closure seam. As already mentioned, this has the particular advantage that the closure seam and the attachment seam can be formed together as heat-seal seam. However, when the attachment seam is formed as adhesive seam, it is also ensured that the attachment seam is provided at a location at which the deep drawing sheet packaging is formed particularly stable.
According to a particularly preferred embodiment form, the packaging body has a rectangular shape, and the circumferential side edge is formed from two opposing first edge portions and two opposing second edge portions, and the attachment seam is arranged only at the first edge portions.
The first edge portions can be long sides or short sides of the packaging body, for example. The packaging body can also have a square shape so that all of the edge portions have the same length, and the attachment seam is always formed from two opposing portions.
In a particularly advantageous manner, the present invention can be used when the deep drawing sheet and the cover film are formed to be single-stream. As was already mentioned, a single-stream configuration exists when the deep drawing sheet and the cover film are made from the same material or materials which can be disposed of together. The material recyclability can be further improved in that the packaging body is substantially unprinted. As meant within the framework of the invention, “unprinted” means that the packaging body has no print over at least more than 90 percent, preferably more than 95 percent, particularly preferably more than 99 percent, of the surface area. Minimal print can consist, for example, in registration marks for production, batch numbers or, for example, storability specifications. However, the printed surface portions can be selected small enough that a collective material recycling is possible in spite of the print.
In order that the packaging body can contain certain information even without print, the shell can have an imprint, particularly an information imprint. An information imprint of this kind can contain the brand name of the packaged product, for example, or can contain other information which will remain present even after removal of the printed material portion. The imprint can be formed, for example, by the use of stamp tools or also by means of a vacuum process in which the still molten, or at least soft, material of the deep drawing sheet is shaped by incorporating local vacuum zones with imprints in the course of forming the shell.
According to a preferred embodiment of the invention, the printed material portion preferably comprises a material selected from the group which includes film, nonwoven, coated paper and multi-layer laminate. In a particularly preferred embodiment, the material for the shell, the cover film and the unprinted material portion are identical, and the entire film packaging is accordingly formed to be single-stream with respect to material. Then, only the print of the printed material portion remains an impediment to materials recycling. An embodiment of this kind has the advantage that it is also possible to use non-detachable attachment seams. According to an embodiment of this kind, the area in the attachment seam is then correspondingly unprinted. In an embodiment of this kind, the material portion can then be removed along the attachment seams, for which purpose an area of weakened material, e.g., in the form of perforation lines, preferably directly adjoins the attachment seams. Accordingly, portions of the unprinted material portion remain on the packaging body but can then be materially recycled together with the latter because of the unprinted configuration.
As regards the use of individual sheets or films, an embodiment in which the deep drawing sheet has a thickness of between 50 μm and 500 μm, particularly between 100 μm and 350 μm, has proven particularly advantageous. The cover film and/or the printed material portion preferably have a thickness of between 20 μm and 150 μm, particularly between 60 μm and 100 μm, and may be formed identically or differently with respect to thickness as well as with respect to the specific configuration.
The cover film and/or the printed material portion and/or the deep drawing sheet are preferably formed of multiple layers and can have at least one, but preferably two, outer layers of a polyolefin, particularly polyethylene or polypropylene. These layers are particularly well suited for sealing so that both the attachment seam and the closure seam can be formed as heat-seal seams. Moreover, the outer layers can be peelable.
The multi-layer films are preferably formed as co-extruded film. In particular, the multi-layer films are formed by blow extrusion or by flat film extrusion or cast extrusion. The printed material portion can be, for example, an undrawn, multi-layer, e.g., three-layer, cast film, wherein all layers are preferably formed on a polypropylene basis. Homopolymers and copolymers in particular are used as polypropylene. The polypropylene used in the outer layers preferably has a lower melting point than that used in the inner layers.
Alternatively, instead of a coextrusion, the individual layers can also be welded or laminated together, in particular adhesively laminated. In adhesive lamination, a two-component adhesive based on polyurethane is used in particular.
Further, the cover film and/or the printed material portion and/or the deep drawing sheet can have a barrier layer. This barrier layer is preferably arranged between an outer layer and an inner layer. The barrier layer can be provided, for example, directly as coextrusion layer, e.g., comprising ethylene vinyl alcohol copolymer (EVOH), and then preferably has a thickness of between 0.5 μm and 20 μm, preferably between 1 μm and 10 μm.
Alternatively, the barrier layer can also be applied as a coating to at least one of the outer layers. Materials suitable for this purpose are silicon dioxide (SiOx) or aluminum dioxide (AlOx), the coating preferably having a thickness of less than 120 nm, preferably less than 100 nm, particularly preferably less than 80 nm. It is further possible to apply a solvent-based coating of polyvinyl alcohol (PVOH) to at least one of the outer layers. The coating of polyvinyl alcohol preferably has a basis weight of 0.2 to 2.8 g/m2. The basis weight is particularly preferably less than 1.5 g/m2, particularly less than 1 g/m2. Further, a metallic layer can also be used as a barrier layer. In this case, at least one of the outer layers is metallized, and the barrier layer preferably has a thickness of less than 220 nm, preferably less than 200 nm, preferably less than 180 nm. However, a metallic layer of this kind has the disadvantage that it can compromise the visual appearance, since the barrier layer is preferably transparent. However, this is impossible with a metallized barrier layer.
In principle, the barrier layers can be formed very thin so that they make up only a small portion of impurities in the corresponding film composite.
Further, particularly in a configuration with polypropylene in the outer layers, a barrier layer of ethylene vinyl alcohol copolymer with a percentage of ethylene of less than 35 percent by weight, preferably less than 30 percent by weight and particularly preferably less than 27 percent by weight, is used. The percentage of polypropylene can be more than 90 percent by weight, preferably more than 95 percent by weight, with respect to the total deep drawing sheet packaging.
The printed material portion preferably has a coating with a sealing lacquer. This may be arranged over the entire surface of the material portion. Alternatively, a coating which is only partial, e.g., strip-shaped, is also sufficient. A coating is then carried out at the locations where sealing is required.
Insofar as the printed material portion is attached to the packaging body via an adhesive seam, an adhesive layer is additionally provided between the cover film or the deep drawing sheet and the printed material portion, the adhesive layer preferably comprising an adhesive based on polyurethane (PU), particularly a two-component polyurethane.
The invention will be described in more detail in the following referring to an exemplary embodiment. The drawings show:
The shell 2 and the cover film 3 are joined together via a closure seam 5. The closure seam 5 is formed as a heat-seal seam and ensures a gas-tight and liquid-tight closure of the packaging body 1.
In the depicted example, neither the shell 2 nor the cover film 3 and, therefore, neither the entire packaging body 1 has print. However, it lies within the scope of the invention in principle that minimal print, e.g., batch numbers, storability data or registration marks, are printed on the packaging body 1. In principle, however, all of the essential printed information is arranged on an additional printed material portion 6 which lies flat on the cover film 3 and is connected to the latter via an attachment seam 7. It will be seen that the attachment seam 7 extends merely along a portion of the surrounding edge of the printed material portion 6 and is divided into two attachment seam portions 7a, 7b. These attachment seam portions 7a, 7b extend along portions of a circumferential side edge of the packaging body 1 and are congruent with the closure seam 5 at least in some areas.
The packaging body 1 has a rectangular shape, and the circumferential side edge is formed from two opposing first edge portions 8 and two opposing second edge portions 9. The attachment seam portions 7a, 7b are arranged only at the first edge portions 8. The first edge portions 8 form the short side, and the second edge portions 9 form the long side of the deep drawing sheet packaging or packaging body 1. With respect to the length of the first edge portions 8, the attachment seam portions 7a, 7b extend over 30 percent to 60 percent so that a relatively large surface region of the cover film 3 is accordingly not covered by the printed material portion 6 and is therefore visible from the outside. An embodiment of this kind is particularly advisable because the cover film 3 is formed transparent and the product 4 is therefore visible through the cover film 3. Accordingly, the final consumer can identify the product 4 without looking at the print on the printed material portion 6.
The exact construction of the deep drawing sheet packaging will be apparent from
The exact construction of the deep-drawing packaging will be apparent from Table 1. Accordingly, the printed material portion 6 and the cover film 3 are both made from the same material which comprises a layer of a biaxially oriented polypropylene (BOPP) and a sealing layer which are laminated together via a two-component polyurethane adhesive (2K-PUR). The sealing layer is a co-extruded layer (PP-EVOH), a comparatively thin layer of ethylene vinyl alcohol copolymer (EVOH) being arranged between two layers of polypropylene (PP). The layer of ethylene vinyl alcohol copolymer (EVOH) forms a gas barrier layer which at least makes it more difficult for oxygen to penetrate, so that, e.g., the storability of foodstuffs can be prolonged. An adhesion promotor (HV) is arranged between the individual layers of co-extruded film in order to improve the adhesion effect.
The deep drawing sheet of the shell 2 is formed as co-extruded film (PP-EVOH) which was produced in particular by blown film extrusion. In blown film extrusion, a tube-shaped preform is formed. This preform is formed from a layer of ethylene vinyl alcohol copolymer (EVOH) and two layers of polypropylene (PP), and the layers of polypropylene enclose the layer of ethylene vinyl alcohol copolymer. The tubular preform is subsequently laid flat, and the layers of polypropylene lying one top of the other are interlocked together resulting in a doubled layer thickness, and the barrier layer can be divided between two layers. The thickness tolerances of the individual layers can be improved in this way. In view of the foregoing, the layer construction of the deep drawing sheet indicated in Table 1 relates to the preform. On the other hand, the indicated thickness of the deep drawing sheet corresponds to the actual film thickness or thickness of the flattened preform with doubled layer construction. Alternatively, the deep drawing sheet can also be produced by cast film extrusion.
The attachment seam 6 is formed at a layer of biaxially oriented polypropylene (BOPP) and at a co-extruded layer (PP-EVOH). The closure seam 5 is correspondingly formed at two layers of polypropylene (PP). The sealing layers can be combined in a known manner so as to reduce the sealing seam strength and allow it to be easily detached.
Viewed in conjunction with
An alternative embodiment form is shown in
The exact construction will be apparent in particular from
Regardless of the specific embodiment, the attachment seam 7 extends only along a portion of the surrounding edge of the printed material portion 6, and the attachment seam 7 is formed in such a way that the printed material portion 6 can be removed relatively easily by grasping it from behind so that it can be recycled separately from the packaging body 1. Accordingly, the attachment seams 7 are formed detachable. Alternatively, it is also possible to form them non-detachable, but at least one perforation should then be provided so that the printed material portion 6 outside of the attachment seams 7 can be removed. In such a case, however, at least the regions of the printed material portion 6 at which the attachment seam portions 7a, 7b extend should be unprinted so that they can be recycled together with the shell 2 and the cover film 3 in a single stream.
The closure seam 5 is also formed detachable in the depicted examples, and at least one portion of this closure seam 5 is formed as safety portion and cannot be detached in this region. This ensures that the cover film 3 remains on the shell 2 even after the packaging body 1 is opened and can accordingly be disposed of and recycled collectively.
In a sealing step, the cover film 3 is sealed with the shell 2 and the printed material portion 6 is sealed with the cover film 3 in a sealing station 12, wherein the closure seam 5 and the attachment seam 7 with the attachment seam portions 7a, 7b are formed. As a result of the joint sealing, the attachment seam portions 7a, 7b extend congruent with the closure seam 5 in the region of the first edge portions 8 which extend in a transverse direction CD in a process of this kind. The second edge portions 9 correspondingly run in machine direction MD.
In a final step, the packaging bodies 1 are separated from one another by cutting through the cover film 3 and the printed material portion 6. The corners of the deep drawing sheet packaging can also be trimmed at the same time. In a trimming process of this kind, between 10 μm and 20 μm can be removed from the edge portions 8, 9 in order to compensate for possible misalignments between the cover film 3 and shell 2. Trimming is preferably carried out only on the second edge portions 9 in order to avoid excessive loss of material. Further, the corners between the first edge portions 8 and second edge portions 9 can also be punched out in a rounded manner.
The adhesive layer 13 has been applied only to the first edge portions 8. The first edge portions 8 now extend in machine direction MD in the form of two strips. Further, the cover film is dimensioned such that the latter covers the cover film 3 over the entire surface thereof. An attachment seam 7 then forms between the cover film 3 and the printed material portion 6 via the adhesive layer 13, and the attachment seam portions 7a, 7b extend in machine direction MD.
The cover film 3 is subsequently sealed with the shell 2 in a sealing station 12 so that a closure seam 5 is formed along the circumferential side edge.
Finally, the individual deep drawing sheet packagings are also separated and the circumferential side edges are trimmed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 107 324.0 | Mar 2020 | DE | national |
