Abstract
A method for producing a cardboard-plastic composite shell (10), in particular an MAP cardboard-plastic composite shell for food products, includes at least the method steps (66, 68, 82, 88) providing a plastic foil (12), pre-forming the plastic foil (12) to form a shell shape (14), providing a cardboard blank (16), and connecting the cardboard blank (16) to the already pre-formed plastic foil (12) in order to form the cardboard-plastic composite shell (10). The cardboard blank (16) provided is not folded or incompletely folded directly before the connection to the pre-formed plastic foil (12). When the cardboard blank (16) is connected to the pre-formed plastic foil (16), the cardboard blank (16) is folded onto the plastic foil (12) by a stamp mechanism (24).
Claims
1. A method for producing a cardboard-plastic composite shell (10), comprising at least the method steps (66, 68, 82, 88): providing a plastic foil (12), pre-forming the plastic foil (12) to form a shell shape (14), providing a cardboard blank (16), connecting the cardboard blank (16) to the already pre-formed plastic foil (12) in order to form the cardboard-plastic composite shell (10), wherein the cardboard blank (16) provided is not folded or incompletely folded directly before the connection to the pre-formed plastic foil (12), wherein when the cardboard blank (16) is connected to the pre-formed plastic foil (16), the cardboard blank (16) is folded onto the plastic foil (12) by a stamp mechanism (24).
2. The method according to claim 1, wherein the cardboard blank (16) is connected to the plastic foil (12) in such a way that the plastic foil (12) and the cardboard blank (16) are separable manually.
3. The method according to claim 1, wherein the plastic foil (12) is connected to the cardboard blank (16) by lamination.
4. The method according to claim 3, wherein a dimensional stability of the cardboard-plastic composite shell (10) is created by the plastic foil (12) that is connected with the cardboard blank (16) by lamination.
5. The method according to claim 1, wherein in the pre-forming the plastic foil (12) is brought, in particular drawn, into a shape which at least substantially corresponds to an inner shape of the cardboard-plastic composite shell (10) that is to be attained.
6. The method according to claim 1, wherein the plastic foil (12) is heated during the pre-forming or directly before the pre-forming.
7. The method according to claim 1, wherein when the cardboard blank (16) is connected to the pre-formed plastic foil (12), a subregion (50) of the cardboard blank (16), which is configured to form a bottom (18) of the cardboard-plastic composite shell (10), is connected to the plastic foil (12) before a further subregion (52) of the cardboard blank (16) which is configured to form a sidewall (20) of the cardboard-plastic composite shell (10).
8. (canceled)
9. The method according to claim 1, wherein the cardboard blank (16) is folded in such a way that the folded cardboard blank (16) remains free of intersections and/or overlaps with itself and with further cardboard blanks.
10. The method according to claim 1, wherein when the cardboard blank (16) is folded, a sealing edge (28) is created which is planar and/or free of layer jumps, and which in particular runs around a shell opening (26) of the finished cardboard-plastic composite shell (10).
11. The method according to claim 1, wherein at least the connection of the cardboard blank (16) to the plastic foil (12) and/or at least a production of a box (30) from the cardboard blank (16) are/is realized completely free of an application of additional gluing materials.
12. A production device (32) for a production of cardboard-plastic composite shells (10) at least from respectively one plastic foil (12) and respectively one cardboard blank (16) by a method according to claim 1, comprising a pre-forming of the plastic foil (12) and a following connecting of the plastic foil (12) to the cardboard blank (16), the production device (32) comprising a foil pre-forming unit (34) and a pressing device (76) with a stamp mechanism (24), wherein the foil-preforming unit (34) comprises at least one stamping tool (36) having an outer contour which corresponds at least substantially to an inner contour of the finished cardboard-plastic composite shell (10) that is to be attained, wherein the stamp mechanism (24) comprises a further stamping tool (80), which is realized complementarily to the stamping tool (36) and is configured for folding and laminating in one common work step.
13. The production device (32) according to claim 12, wherein the foil pre-forming unit (34) comprises at least one heating device (28) for a heating of the plastic foil (12) before and/or during a pre-forming of the plastic foil (12).
14. The production device (32) according to claim 13, wherein the heating device (28) is realized at least partially integrally with the stamping tool (36).
15. The method according to claim 1, wherein in the pre-forming the plastic foil (12) is drawn into a shape which at least substantially corresponds to an inner shape of the cardboard-plastic composite shell (10) that is to be attained.
16. The method according to claim 10, wherein the sealing edge (28) runs around a shell opening (26) of the finished cardboard-plastic composite shell (10).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Further advantages will become apparent from the following description of the drawings. In the drawings exemplary embodiments of the invention are illustrated. The drawings, the description and the claims contain a plurality of features in combination. Someone skilled in the art will purposefully also consider the features separately and will find further expedient combinations.
[0036] It is shown in:
[0037] FIG. 1 a schematic perspective view of a cardboard-plastic composite shell formed from a plastic foil and a cardboard blank,
[0038] FIG. 2 a schematic plan view onto the cardboard blank in a non-folded state,
[0039] FIG. 3 a schematic illustration of a production device for a production of the cardboard-plastic composite shell during a work step,
[0040] FIG. 4 a schematic illustration of the production device during a first further work step,
[0041] FIG. 5 a schematic illustration of the production device during a second further work step,
[0042] FIG. 6 a schematic illustration of the production device during a third further work step,
[0043] FIG. 7a a schematic illustration of the production device during a first partial work step of a fourth further work step,
[0044] FIG. 7b a schematic illustration of the production device during a second partial work step of the fourth further work step,
[0045] FIG. 8 a schematic illustration of the production device during an alternative fourth further work step, and
[0046] FIG. 9 a schematic flow chart of a method for producing the cardboard-plastic composite shell.
DETAILED DESCRIPTION
[0047] FIG. 1 shows a schematic perspective illustration of a cardboard-plastic composite shell 10. The cardboard-plastic composite shell 10 is embodied as an MAP cardboard-plastic composite shell for food products. The cardboard-plastic composite shell 10 comprises a plastic foil 12. The cardboard-plastic composite shell 10 comprises a cardboard blank 16 (see also FIG. 2). Preferably the cardboard-plastic composite shell 10 consists just of the cardboard blank 16 and the plastic foil 12, and in a closed state possibly of a cover foil (not shown). The cardboard blank 16 is folded to form a box 30. The box 30/the cardboard-plastic composite shell 10 forms a storage region 40 on an inner side 44. The box 30/the cardboard-plastic composite shell 10 is configured, for example, for receiving food products, like meat, cheese etc. Of course the storage region 40 may as well be configured for receiving other objects. Preferably the materials at least of the plastic foil 12 and/or of the cover foil, if applicable also of the cardboard blank 16, are adapted to the object that is to be received and to the respective storage requirements of the object. The plastic foil 12 provides the barrier properties required depending on the stored object and may hence be equipped with different adapted chemical-physical properties. The plastic foil 12 is expandable. The plastic foil 12 is sealable, such that the finished cardboard-plastic composite shell 10 can be closed with the cover foil. The inner side 44 of the box 30/the cardboard-plastic composite shell 10 forms the storage region 40. The storage region 40 is configured for receiving the object. The cardboard-plastic composite shell 10 has a shell opening 26. Objects can be brought into the cardboard-plastic composite shell 10 through the shell opening 26 and/or can be taken from the cardboard-plastic composite shell 10 through the shell opening 26. The storage region 40/the shell opening 26 can be sealed/closed all around (hermetically) by the cover foil.
[0048] The storage region 40 of the box 30 is completely lined with the plastic foil 12. The storage region 40 of the box 30 is lined with the plastic foil 12 in such a way that the plastic foil is connected face-to-face with the cardboard of the cardboard blank 16 folded to form the box 30. The plastic foil 12 and the cardboard of the cardboard blank 16 are connected with each other such that simple manual separation of plastic foil 12 and cardboard is enabled for a transfer of the plastic foil 12 and the cardboard to different recycling streams. The cardboard-plastic composite shell 10 has a gripping tab 48. The gripping tab 48 is realized integrally with the plastic foil 12. The gripping tab 48 implements a handling point of the plastic foil 12 for pulling the plastic foil 12 off the cardboard of the cardboard blank 16.
[0049] The box 30 folded from the cardboard blank 16 is free of gaps in corner regions 42 of the box 30. The box 30 folded from the cardboard blank 16 is free of gaps, except for the shell opening 26 of the cardboard-plastic composite shell 10.
[0050] The cardboard blank 16 that has been folded to form the box 30 is free of intersections and/or overlaps with itself. The cardboard blank 16 that has been folded to form the box 30 is free of intersections and/or overlaps with parts of further cardboard blanks 16. The cardboard blank 16 that has been folded to form the box 30 comprises a sealing edge 28. The sealing edge 28 is configured for a fastening of the cover foil. The sealing edge 28 is realized so as to run completely around an opening of the box 30/around the shell opening 26. The sealing edge 28, like the inner side 44 of the box 30, is completely covered by the plastic foil 12. The cardboard blank 16 that has been folded to form the box 30 has an outer side 46. The outer side 46 of the cardboard blank 16 folded to form the box 30 is situated opposite the inner side 44. The outer side 46 of the cardboard blank 16 folded to form the box 30 is situated opposite the storage region 40. The outer side 46 is free of a covering by the plastic foil 12 or by a further plastic foil 12. A dimensional stability of the cardboard-plastic composite shell 10 is created at least mostly by the plastic foil 12 that is connected with the cardboard blank 16 by lamination. The cardboard of the cardboard blank 16 serves mostly for a reinforcement of an impact protection/a mechanical protection of the cardboard-plastic composite shell 10 and/or for a reduction of a requirement for synthetic material of the cardboard-plastic composite shell 10.
[0051] FIG. 2 shows the cardboard blank 16 in a non-folded state. The cardboard blank 16 has a subregion 50 which is configured to form a bottom 18 of the box 30/the cardboard-plastic composite shell 10. The cardboard blank 16 has further subregions 52 which are configured to form sidewalls 20 of the box 30/the cardboard-plastic composite shell 10. When the box 30 is folded from the cardboard blank 16, the further subregions 52 are folded (upwards) out of the plane of the subregion 50. The sidewalls 20 of the box 30/the cardboard-plastic composite shell 10 are situated obliquely or perpendicularly to the bottom 18 of the box 30. An angle 64 included by a sidewall 20 of the box 30 and the bottom 18 of the box 30 is less than 150?, preferably less than 120?. The subregions 52, which are configured to form the sidewalls 20 of the box 30/the cardboard-plastic composite shell 10, have side edges 54, 56. The side edges 54, 56 of the subregions 52 that form the sidewalls 20 are free of gluing tabs. Opposite-situated side edges 54, 56 of the subregions 52 that form the sidewalls 20 contact each other in a state when the cardboard blank 16 has been folded to form the box 30. The opposite-situated side edges 54, 56 of the subregions 52 that form the sidewalls 20 contact each other, in the state when the cardboard blank 16 has been folded to form the box 30, without overlapping each other. The cardboard blank 16 comprises additional further subregions 58, which are configured to form the sealing edge 28 of the box 30/the cardboard-plastic composite shell 10. The subregions 58, which are configured to form portions of the sealing edge 28 of the box 30/the cardboard-plastic composite shell 10, have side edges 60, 62. The side edges 60, 62 of the subregions 58 that form the sealing edge 28 are free of gluing tabs. Opposite-situated side edges 60, 62 of the subregions 58 that form the sealing edge 28 contact each other in a state when the cardboard blank 16 has been folded to form the box 30. The opposite-situated side edges 60, 62 of the subregions 58 that form the sealing edge 28 contact each other, in the state when the cardboard blank 16 has been folded to form the box 30, without overlapping each other. When the cardboard blank 16 is folded to form the box 30, the subregions 58 that form the sealing edge 28 are folded away from the sidewalls 20. In the state when the cardboard blank 16 has been folded to form the box 30, the subregions 58 that form the sealing edge 28 are situated in a common plane. The plane, in which the subregions 58 of the cardboard blank 16 folded to form the box 30, which form the sealing edge 28, are situated, extends parallel to the subregion 50 of the cardboard blank 16 which forms the bottom 18 of the box 30.
[0052] FIGS. 3 to 8 show schematically and step-wise a method for producing the cardboard-plastic composite shell 10 using a production device 32. The production device 32 is configured for carrying out the method according to the invention. For a production of the cardboard-plastic composite shells 10 from respectively one plastic foil 12 and respectively one cardboard blank 16, a method is carried out by the production device 32, which comprises at least one pre-forming step 66 in which the plastic foil 12 is pre-formed, and at least one connecting step 68 in which, following the pre-forming step 66, the plastic foil 12 is connected to the cardboard blank 16. FIG. 1 shows the cardboard-plastic composite shell 10 fully manufactured by means of the production device 32. The production device 32 comprises a foil pre-forming unit 34 (see especially FIGS. 4 and 5). The foil pre-forming unit 34 is configured to pre-form a foil web, firstly provided in planar fashion (see FIG. 3), such that a pre-form of the plastic foil 12 is obtained which corresponds approximately to an inner contour of the finished cardboard-plastic composite shell 10 that is to be achieved. For this purpose, the foil pre-forming unit 34 comprises a stamping tool 36. The stamping tool 36 is realized as a lower punch. The stamping tool 36 has an outer contour corresponding at least substantially to an inner contour of the finished cardboard-plastic composite shell 10 that is to be achieved. The foil pre-forming unit 34 comprises a frame 70, in particular a stamping frame. The frame 70 is configured for clamping a portion of the foil web of the plastic foil 12 in a fixed planar manner before an implementation of the pre-forming step 66. The stamping tool 36 is configured to create, by pressing the plastic foil 12 clamped in the frame 70, a pre-form which roughly corresponds to the inner contour of the finished cardboard-plastic composite shell 10 that is to be achieved.
[0053] The foil pre-forming unit 34 comprises at least one heating device 38. The heating device 38 is configured for a heating of the plastic foil 12 before the pre-forming of the plastic foil 12 (see FIG. 4) and/or during the pre-forming of the plastic foil 12 (see FIG. 5). The heating device 38 comprises a first heating unit 72 (see FIG. 4). The first heating unit 72 is embodied as a heating unit 72 that is realized separately from the stamping tool 36. The first heating unit 72 is at least configured for heating the plastic foil 12 before the pre-forming. Alternatively or additionally, the first heating unit 72 may be configured for heating the plastic foil 12 during the pre-forming. The first heating unit 72 comprises a heating fan or a heating radiator. The first heating unit 72 is configured to apply a heated airflow or a heat radiation onto the foil. Alternatively or additionally, the first heating unit 72 may also be configured for heating the stamping tool 36, in particular a surface of the stamping tool 36. The heating device 38 comprises a second heating unit 74 (see FIG. 5). The second heating unit 74 is realized at least partially integrally with the stamping tool 36. The stamping tool 36 comprises an internal heating source, for example a heating coil. The second heating unit 74 is at least configured for heating the plastic foil 12 during the pre-forming. The second heating unit 74 is configured for heating the stamping tool 36, in particular a surface of the stamping tool 36. It is conceivable that the heating device 38 comprises only the first heating unit 72 or only the second heating unit 74. In FIGS. 5 to 8 the further production steps are shown, by way of example, using only the second heating unit 74. Alternatively or additionally, the first heating unit 72 could also be used in the production steps of FIGS. 5 to 8.
[0054] The production device 32 comprises a pressing device 76 (see FIGS. 7a to 8). The pressing device 76 is configured for pressing the cardboard blank 16 onto the pre-formed plastic foil 12. The stamping tool 36 forms a counterpiece as a counterholder against a pressing force of the pressing device 76. The pressing device 76 is first pressed onto the stamping tool 36 from a direction that is opposed to a stamping movement of the stamping tool 46, with the plastic foil 12 and the still non-folded or only partially folded cardboard blank 16 being arranged between the stamping tool 36 and the pressing device 76. By the cardboard blank 16 being pressed onto the plastic foil 12 and, if applicable, simultaneous heating of the plastic foil 12, the plastic foil 12 is laminated onto the cardboard blank 16. During the pressing process of the pressing device 76 the stamping tool 36 remains immobile. In the exemplary embodiment of FIGS. 7a and 7b, at first the bottom 18 of the cardboard blank 16 is laminated and then the sidewalls 20. In the alternative exemplary embodiment of FIG. 8, the bottom 18 and the sidewalls 20 of the cardboard blank 16 are laminated at the same time.
[0055] The production device 32 illustrated in FIGS. 7a and 7b comprises a pressing device 76 with a folding mechanism 22. The folding mechanism 22 is configured for folding the cardboard blank 16. The folding mechanism 22 is configured for folding the cardboard blank 16 for a formation and lamination of the sidewalls 20. The folding mechanism 22 presses the subregions 52 of the cardboard blank 16, which form the sidewalls 20, onto the pre-formed plastic foil 12. In addition, it is conceivable that the stamping tool 36 comprises a suction mechanism 78 which is configured to suction the plastic foil 12 to the stamping tool 36, at least in the regions of sidewalls 20 that are to be formed. This advantageously allows optimizing a lamination of the sidewalls 20, in particular as it is possible to prevent a formation of air bubbles or the like between the plastic foil 12 and the stamping tool 36.
[0056] The production device 32 illustrated in FIG. 8 comprises a pressing device 76 with a stamp mechanism 24 (instead of the folding mechanism 22 of FIGS. 7a and 7b). The stamp mechanism 24 comprises a further stamping tool 80, which is realized complementarily to the stamping tool 36. The further stamping tool 80 is embodied as an upper punch. The further stamping tool 80 is pressed onto the cardboard blank 16 that has been laid upon the pre-formed plastic foil 12 from a direction that is opposed to a direction in which the stamping tool 36 is moved during the pre-forming of the plastic foil 12. The further stamping tool 80 folds and laminates in one common work step.
[0057] FIG. 9 shows a schematic flowchart of a method for producing the cardboard-plastic composite shell 10. FIG. 1 shows the cardboard-plastic composite shell 10 that has been fully manufactured by the method described. In at least one method step 82, a foil web of the plastic foil 12 is spread, e. g. rolled out, in a planar fashion. In the method step 82 the plastic foil 12 is provided. In at least one further method step 84, a section of the foil web of the plastic foil 12 is clamped into the frame 70 (see also FIG. 3). In at least one (optional) further method step 86, at least the section of the plastic foil 12 that is clamped in the frame 70 is heated, for example by means of the first heating unit 72. In the method step 86 the plastic foil 12 is heated directly before the pre-forming. In the pre-forming step 66 the stamping tool 36 is pressed into the frame 70 (see also FIGS. 4 and 5). Herein the plastic foil 12 is pre-formed. The stamping tool 36 may herein be heated, for example by the second heating unit 74. In the pre-forming step 66 the plastic foil 12 is heated during the pre-forming. It is however also conceivable, depending on the chemical-physical properties of the plastic foil 12, that the heating may be completely dispensed with during the pre-forming. In the pre-forming step 66 the plastic foil 12 is pre-formed into the shell shape 14, which preferably already has a strong similarity to the shape of the inner side 44 of the cardboard-plastic composite shell 10. Optionally the plastic foil 12 is already in the pre-forming step 66 suctioned sideways to the stamping tool 36 (see also FIG. 7a). In the pre-forming step 66 the plastic foil 12 is pre-formed in order to form the shell shape 14.
[0058] In a further method step 88, the cardboard blank 16 is laid upon the pre-formed plastic foil 12. In the method step 88 the cardboard blank 16 is provided. The cardboard blank 16 provided in the method step 88 is non-folded or incompletely folded directly before being connected to the pre-formed plastic foil 12. The cardboard blank 16 is herein laid onto the plastic foil 12 on a side of the plastic foil 12 that is situated opposite the stamping tool 36 (see also FIG. 6). In the following connecting step 68, the plastic foil 12 is laminated to the cardboard blank 16. In the connecting step 68, the cardboard blank 16 is connected to the already pre-formed plastic foil 12 in order to form the cardboard-plastic composite shell 10. In the connecting step 68, the cardboard blank 16 is connected to the plastic foil 12 in such a way that the plastic foil 12 and the cardboard blank 16 can be separated manually. In the connecting step 68, the cardboard blank 16 is connected to the plastic foil 12 in such a way that the plastic foil 12 and the cardboard blank 16 can be separated in a manner suitable for recycling. The connection of the cardboard blank 16 to the plastic foil 12, in particular the connecting step 68, is realized completely without gluing materials, i. e. in particular completely free of an application of an additional gluing material.
[0059] If the connecting step 68 is carried out with the folding mechanism 22 shown in FIGS. 7a and 7b, when connecting the cardboard blank 16 to the pre-formed plastic foil 12, the subregion 50 of the cardboard blank 16, which is intended to form the bottom 18 of the cardboard-plastic composite shell 10, is realized in a first partial connecting step 90 which lies temporally before a second partial connecting step 92, in which the further subregions 52 of the cardboard blank 16, intended to form the sidewalls 20 of the cardboard-plastic composite shell 10, are connected to the plastic foil 12. In the connecting step 68, in this case the cardboard blank 16 is folded onto the plastic foil 12 by means of the folding mechanism 22. Herein the cardboard blank 16 is folded in such a way that the folded cardboard blank 16 remains free of intersections and/or overlaps with itself and with further cardboard blanks. Furthermore, in the connecting step 68, in particular in the second partial connecting step 92, the cardboard blank 16 is folded so as to create the planar and layer-jump-free sealing edge 28 which runs around the shell opening 26 of the finished cardboard-plastic composite shell 10. In the folding of the cardboard blank 16 in the connecting step 68, the box 30 is created from the cardboard blank 16. The production of the box 30 from the cardboard blank 16 is realized completely without gluing materials. The production of the box 30 from the cardboard blank 16 is realized completely without using/applying additional gluing materials.
[0060] As an alternative, an alternative connecting step 94, requiring no folding mechanism 22, may be carried out instead of the connecting step 68 in which the folding mechanism 22 is used. In the alternative connecting step 94, when the cardboard blank 16 is connected to the pre-formed plastic foil 12, the cardboard blank 16 is folded onto the plastic foil 12/folded to form the box 30 by means of the stamp mechanism 24, and is at the same time connected to the plastic foil 12 in the same work step (see also FIG. 8). In the alternative connecting step 94 the plastic foils 12 and the cardboard blanks 16, which are arranged layer-wise above one another, are pressed with each other between two complementary stamping tools 36, 80, wherein the plastic foil 12 was already pre-formed temporally before the pressing with the cardboard blank 16, and preferably the stamping tool 36 that adjoins the plastic foil 12 is heated.
[0061] In at least one further method step 96, the fully formed cardboard-plastic composite shell 10 is taken from the production device 32. The non-closed cardboard-plastic composite shell 10 is stackable with further non-closed cardboard-plastic composite shells 10. In at least one further method step 98, the fully formed cardboard-plastic composite shells 10 are fed to a filling line, where the storage region 40 of the cardboard-plastic composite shells 10 is filled with objects. In at least one further method step 100, the filled cardboard-plastic composite shells 10 are fed to a closing line, where the storage region 40 of the filled cardboard-plastic composite shells 10 is closed, in particular gas-tightly closed, by the cover foil. Before a closing of the filled cardboard-plastic composite shells 10, the air remaining in the cardboard-plastic composite shells 10 may be replaced by a gas, in particular an inert gas/shielding gas like nitrogen or the like.
