Device and method for decorating molded parts made of thermoplastic film with cutouts and a decorated molded part produced according to the method

Abstract

Device for decorating molded parts made of thermoplastic film with one- or multi-part die-cut or cut blanks in a thermoforming machine, wherein the device comprises a magazine (4) with magazine positions for storing stacks (5), a device for singulating blanks (6) with cutting positions and cutting grippers for singulating and transferring blanks from the stacks of blanks, a device for erecting blanks (7) for erecting blanks, a transfer unit (8) with transfer positions for transferring the erected blanks in the pitch of the cavities of a forming tool (10) or forming / punching tool (11) to a forming tool (10) or forming / punching tool (11), and a removal unit for removing the decorated molded parts from the forming tool (10) or forming / punching tool (11) of the thermoforming machine, characterized in that the stacks of blanks (5) contain at least two different types of blanks (1,9) comprising, wherein the blanks (1, 9) have different contours and wherein the blanks (1, 9) are each placed in the blank stacks (5) such that they form a stacking pattern parallel to the longitudinal axis of the blank stacks (5) and wherein the stacking pattern is an alternating sequence of the blanks (1, 9).

Description

[0001] The invention relates to a device and a method for decorating molded parts made of thermoplastic film with blanks and to a decorated molded part produced by the method. State of the art

[0002] US Patent No. 4,533,065 A discloses a container comprising a cardboard part and a plastic part. The cardboard part consists of a first part with a one-piece rim and first wall panels integrally connected to the rim, and a second part with a base panel and second wall panels. The first and second wall panels are arranged alternately next to each other to form a continuous wall.

[0003] JP S57-163 636 A discloses a container in which a cardboard box forming the entire upper edge surface of a container and a cardboard box forming the bottom of the container are manufactured separately and joined by gluing a plastic film to the inner surface of the container. This is intended to give the upper surface of the container a flat shape without a notch in the corners.

[0004] JP 2001-278246 A describes a paper container comprising a paper container main body made of a main blank and a sub-blank consisting primarily of paper, and an inner protective film layer made of a thermoplastic film that is tightly bonded to the inner surface of the paper container main body. The main blank consists of a frame-shaped flange and one or more pairs of opposite side surfaces of the main blank, each of which is connected by folds to the sides on the inside of the flange. The sub-blank consists of a bottom surface, side surfaces of the sub-blank, and overlay pieces, each of which is connected by folds to each of the side surfaces of the sub-blank. The paper container is manufactured by overlapping the overlay pieces on a portion of the flange of the main blank.

[0005] Patent DE 10 2012 005 915 B4 discloses a device and method for decorating molded parts made of heated thermoplastic film. In this process, blanks are separated from the stacks of blanks in a magazine for storing blank stacks and transferred to a device that erects several blanks and pushes the blanks together from the magazine's pitch to the pitch of the forming tool. The device transfers the erected blanks to a forming or forming / punching tool, where the plastic film is formed into labeled molded parts.Document EP 3693284 A discloses an article from the paper industry for producing an outer framework of a container, comprising an inner layer of thermoplastic material and having a bottom wall and a plurality of side walls, as well as an annular peripheral flange, the outer framework extending on the peripheral flange, on the side walls and on the bottom wall, the article comprising a continuous annular frame intended to form the outer framework of the container on the peripheral flange of the container, and a plurality of wings extending from the continuous annularly extending frame, each of the wings intended to form the outer framework on one of the side walls of the container and at least one of the wings also intended to form the outer framework on the bottom wall of the container.

[0006] Document EP 3489005 B1 discloses a method and a forming tool for producing packaging, comprising the following steps: providing a pre-punched material sheet from which a partial surface is incompletely punched out, such that the partial surface is connected to a remaining surface of the material sheet via a plurality of retaining lugs; positioning the pre-punched material sheet over a forming die of a forming tool such that the partial surface of the material sheet at least partially covers an opening of a forming cavity of the forming die; clamping the remaining surface of the material sheet against a contact surface of the forming die; sucking the partial surface of the material sheet by means of negative pressure onto an insert that is height-adjustable in the forming cavity of the forming die in a starting position of the height-adjustable insert;and moving the height-adjustable insert from the starting position along a travel direction further into the mold cavity, wherein the partial surface of the material sheet is drawn into the mold cavity and thus formed into a packaging tray.;

[0007] If cardboard is used as the material for blanks to reduce the thickness of the plastic used, the design of the blank results in gaps and interruptions in the area of ​​the flange of the molded part. This leads to leaks when sealing the decorated molded part with reduced plastic in packaging machines.

[0008] Containers manufactured using the so-called PaperSeal process are sometimes made from flat cardboard blanks. The cardboard blanks are equipped with cutting and creasing lines so that the cardboard blanks are erected in an erecting unit to create a virtually closed cardboard sleeve with a limited depth. This outer cardboard sleeve is then lined with a plastic film on the inside to prevent oxygen ingress. The arrangement of the cutting lines enables a closed seal edge. The geometry of the erected containers is limited because the walls are erected from the inside of the blanks, thus producing only relatively flat containers. Task

[0009] The invention is based on the object of improving the known device and the known method for decorating molded parts with blanks and of providing an improved decorated molded part.

[0010] This object is achieved according to the invention by the features specified in claim 1 and in the subordinate claims 14 and 20. Further preferred embodiments of the invention emerge from the remaining features specified in the respective subclaims. Example

[0011] A device for decorating molded parts 2 made of thermoplastic film with blanks 1, 9 is proposed, the device comprising a magazine 4 for storing stacks of blanks 5, a device 6 for separating blanks 1, 9 from the stacks of blanks 5, a device 7 for erecting blanks 1, 9, which erects the blanks 1, 9 and, if necessary, pushes them together from the gauge of the magazine 4 to the gauge of the forming tool 10 or forming / punching tool 11, and a transfer unit 8 for transferring the labeled molded parts 17 to a forming tool 10 or forming / punching tool 11. In an advantageous further development, the invention provides for the device to be integrated into a thermoforming machine 3 or to be connected downstream of a thermoforming machine 3. Furthermore, it is provided that the blanks 1, 9 are designed as punched or cut flat blanks.The magazine 4 advantageously has interchangeable, modular magazine format parts 12 for storing stacks of blanks 5. The device 7 for erecting the blanks 1, 9 is installed in each receiving device for the blanks 1, 9 in the device that pushes the blanks 1, 9 together from the pitch of the magazine 4 to the pitch of the forming tool 10 or forming / punching tool 11. The transfer unit 8 is equipped with suction mandrels 14 for gripping the erected blanks 1, 9. With favorable dimensions of the blanks 1, 9, the pushing of the blanks 1, 9 together from the pitch of the magazine 4 to the pitch of the forming tool 10 or forming / punching tool 11 can be omitted. It is provided that the device has a handling 16 for removing the decorated molded parts 17 from the transfer unit 8. The decorated molded parts 17 are stacked on a conveyor belt to form molded part stacks.Further details of the invention are described in more detail below with reference to the schematic drawings. They show:

[0012] The Fig. 1 - 6 show the sequence of the method according to the independent claim 9. Fig. Figure 1 shows the first substep of the method for decorating molded parts with blanks 1, 9. Blanks 1, 9 are provided in blank stacks 5 in the magazine 4. The device 6 for separating blanks 1, 9 removes the top two blanks 1, 9 from the blank stacks 5. The first and second holding devices 38, 39 hold the first and second blanks 1, 9. Fig. Figure 2 shows the second substep of the process. The device 6 for separating blanks 1, 9 transfers the blanks 1, 9 to the device 7 for erecting the blanks 1, 9. The device 7 receives the blanks 1, 9 in preform shells 40 and at least partially erects the flat blanks 1, 9. This shortens the extension of the blanks 1, 9 compared to the extension of the blanks 1, 9 in the flat, non-erected state. With favorable blanks, the complete erection of the blanks 1, 9 can also take place in a single step. Fig. Figure 3 shows the third sub-step of the process. The erecting device 7 pushes the erected blanks 1, 9 from the gauge of the magazine 4 to the gauge of the forming tool 10 or the forming / punching tool 11 and transfers the erected blanks 1, 9 to the transfer unit 8. If the dimensions of the blanks 1, 9 are favorable, pushing the blanks 1, 9 together from the gauge of the magazine 4 to the gauge of the forming tool 10 or the forming / punching tool 11 can be omitted. The transfer unit 8 receives the erected blanks 1, 9 using suction mandrels for blanks 14. Fig. Figure 4 shows the fourth sub-step of the process. The transfer unit 8 transfers the fully erected blanks to a forming tool 10 or forming / punching tool 11. In the forming tool 10 or forming / punching tool 11, the heated plastic film is brought into contact with the blanks 1, 9 and bonded to the blanks 1, 9, thus producing the decorated molded parts 17. Fig. 5 The transfer unit 8 removes the decorated molded parts 17 from the molding tool 10 or mold / punching tool 11. A handling unit 16 removes the labeled molded parts 17 from the transfer unit 8 and places them on a conveyor belt (not shown), thus forming molded part stacks (not shown). A not shown alternative to Fig. 5 allows, according to this method, if the dimensions of the blanks 1, 9 allow it, that the blanks 1, 9 are transferred with a transfer unit 8 into a forming tool 10 or forming / punching tool 11, transported further connected to the film strip, subsequently separated and finally transported out. Fig. Figure 6 shows two exemplary blanks 1, 9. The blanks 1, 9 have cutting lines 25 and folding lines 24. They also have base surfaces 34, side surfaces 35, and contact surfaces 27. The cutting lines 25 delimit the blanks 1, 9. During the erection process, the blanks 1, 9 are bent at the folding lines 24, usually around 90°. The blanks 1, 9 are joined together at the contact surfaces 27. The blank 1 has a flange 26, which is placed under the upper edge 20 of the decorated molded part 17. Fig. 7 shows a magazine plate 30 with the blanks 1, 9, wherein the blanks 1, 9 are held in position by side pins 28 and corner pins 29. Fig. 8 shows a stripper plate 33 which, when stripping blanks 1, 9 by means of corner strippers 31 and side strippers 32, prevents more than one blank 1, 9 of each type from being stripped. Fig. 9 shows a decorated molded part 17. The joined blanks 1, 9 enclose the molded part 17 and support the upper edge 20 of the molded part 17 with the circumferential flange 26 of the first blank 1. Fig. 10 shows the joined blanks 1, 9. The blanks 1, 9 are joined at the joining surfaces 27. Fig. Figure 11 shows an exemplary blank according to the prior art. A blank with five sections has miter cuts 21 that are intended to butt against each other when erected, thus entailing the risk of gaps occurring between two edges of the miter cuts 21. If gaps occur, there is a risk of leaks if the molded part is sealed with a lid material. Fig. 12 shows a decorated molded part 17 according to the inventive concept, in which cutouts 37 are introduced into the blanks 1, 9. During the molding and decorating process, the thermoplastic film is formed through the cutouts 37 onto a wall of a molding tool, thus forming a raised portion 36. After molding, the raised portion 36 thus forms an undercut relative to the cutouts 37, thus creating a positive connection between the molded part 17 and the blanks 1, 9, so that no adhesive bonding is required to permanently bond the blanks 1, 9 to the molded part 17. Fig. 13 shows a variant of a pair of blanks in which the blanks are connected via a perforation 13. During erection, the blanks are separated from each other via the perforation 13 and positioned so that they together form a tray. Fig.14 shows a further variant of a pair of blanks, in which the right blank has all the side surfaces 35 which, in the erected state, form the essential parts of the shell, while the left blank has only joining surfaces 27 so that the side surfaces 35 are connected to the flange 26.

[0013] The invention provides for the device for decorating molded parts made of thermoplastic film with single-part or multi-part punched or cut blanks in a thermoforming machine, wherein the device has a magazine 4 with magazine locations for storing stacks 5, a device for separating blanks 6 with blank locations and blank grippers for separating and transferring blanks from the blank stacks, an erecting device 7 for erecting blanks, a transfer unit 8 with transfer locations for transferring the erected blanks in the pitch of the cavities of a molding tool 10 or molding / punching tool 11 to a molding tool 10 or molding / punching tool 11 and a removal unit for removing the decorated molded parts from the molding tool 10 or molding / punching tool 11 of the thermoforming machine,that the blank stacks 5 comprise at least two different types of blanks 1, 9, wherein the blanks 1, 9 have different contours and wherein the blanks 1, 9 are each placed in the blank stacks 5 such that they have a stacking pattern parallel to the longitudinal axis of the blank stacks 5, and wherein the stacking pattern represents an alternating sequence of the blanks 1, 9. The blanks 1, 9 in the blank stacks 5 are advantageously connected to one another. In another embodiment, the blanks 1, 9 in the blank stacks 5 are connected to one another by a tearable perforation. The magazine positions are provided with replaceable,modular magazine format parts 12. The erecting device 7 also undertakes any necessary shifting of erected blanks from the gauge of the magazine to the gauge of the cavities of the forming tool 10 or forming / punching tool 11. The device advantageously has a removal unit for removing the decorated molded parts from the forming tool 10 or forming / punching tool 11 of the thermoforming machine. The magazine 4 has a magazine plate 30 which, for fixing the blanks 1, 9, comprises both side pins 28 which have a contact surface to the blanks 1, 9, and corner pins 29 which have two contact surfaces to the blanks 1, 9. In a further development, the magazine 4 has a magazine plate 30 which, for fixing the blanks 1, 9, comprises exclusively side pins 28 which have a contact surface to the blanks 1, 9. The magazine 4 comprises a stripper plate 33,which, for stripping blanks 1, 9 that are not being sucked onto the workpieces, has both side strippers 32, which have one stripping surface opposite the workpieces 1, 9, and corner strippers 31, which have two stripping surfaces opposite the workpieces 1, 9. The magazine 4 comprises a stripper plate 33, which, for stripping blanks 1, 9 that are not being sucked onto the workpieces, has only side strippers 32, which have one stripping surface opposite the workpieces 1, 9. The device advantageously has first holding devices 38 for receiving and transporting first workpieces 1 and second holding devices 39 for receiving and transporting second workpieces 9. The holding devices 38, 39 are designed to be displaceable relative to one another. The erecting device 7 has third holding devices 23 for erecting and holding the erected workpieces 1,9. The device has 7 preform shells 40 for erecting the blanks 1, 9. It is further provided according to the invention that the method for operating a device for decorating molded parts formed or formed and punched in a thermoforming machine from thermoplastic film, wherein the device separates blanks 1, 9 from the blank stacks 5 from a magazine 4 for storing blank stacks 5 by means of a transfer unit 8 with blank grippers and transfers them to a device for erecting 7, which erects the blanks 1, 9, transfers them to a transfer unit 8, which transfers the erected blanks 1, 31 to a forming tool 10 or forming / punching tool 11 and a removal unit removes the decorated molded parts 17 from the forming tool 10 or forming / punching tool 11, is designed in such a way that the device for separating blanks 6 has at least two different Cuts 1,9 are separated from the blank stacks 5 in one work cycle and transferred to a device for erecting 7, which erects the at least two blanks 1, 9 with a device for erecting 7, to a transfer unit 8, which transfers the at least two erected blanks 1, 9 to a forming tool 10 or forming / punching tool 11. The device for erecting 7 pushes the blanks 1, 9 together from the pitch of the magazine 4 to the pitch of the forming tool 10 or forming / punching tool 11. A removal unit removes the decorated molded parts 17 from the forming tool 10 or forming / punching tool 11. First and second holding devices 38, 39 are spaced apart from one another and, in interaction with a movement of the device for separating blanks 6, erect the first and second blanks 1, 9. Further holding devices 23 on the erecting devices 7 align the first and second blanks 1,9. The device for separating blanks 6 transfers the first and second blanks 1, 9 to the devices for erecting 7 in preform shells 40, in which the first and second blanks 1, 9 are at least partially erected. Finally, the invention provides for the decorated molded part, consisting of a molded part 2 thermoformed from heated thermoplastic film with an edge 20 and a decorative portion, to be designed such that the decorative portion consists of at least two blanks 1, 9, wherein the first blank 1 is attached below the edge 20 and has a gapless section below the edge 20, and wherein the first blank 1 is connected to the second blank 9 below the flange 26. It is advantageouswhen the first blank 1 is connected to the second blank 9 by means of a perforation 13, at least in the blank stack 5. In an advantageous embodiment, the first blank 1 is separated from the second blank 9 at the perforation 13 outside the blank stack 5. The blanks 1, 9 are permanently connected to the molded part 2, with elevations 36 on the surfaces of the walls of the molded part 2 penetrating cutouts 37, which are introduced into the blanks 1, 9 in such a way that, after the plastic film of the molded part 2 has been formed, undercuts of the elevations 36 are produced relative to the cutouts 37. List of reference symbols 1 First cut 2 molded part 3 Thermoforming machine 4 Magazine 5 cutting stacks 6 devices for separating blanks 7 Device for erecting 8 Transfer unit 9 Second cut 10 mold tool 11 Form / punching tool 12 magazine format parts 13 Perforation 14 suction mandrels for cutting 15 suction cups for decorated molded parts 16 Handling 17 Decorated molding 18 Distancing facility 19 restraint devices 20 Rand 21 Miter cut 22 Device for forming stacks of molded parts 23 Third holding device 24 fold line 25 Cutting line 26 Flange 27 Joining surface 28 side pins 29 corner pins 30 magazine plate 31 corner wipers 32 side scrapers 33 scraper plate 34 floor area 35 side surface 36 Survey 37 Excerpt 38 First holding device 39 Second holding device 40 preform shell

Claims

[1] A device for decorating molded parts made of thermoplastic film with single-part or multi-part punched or cut blanks in a thermoforming machine, the device comprising a magazine (4) with magazine locations for storing stacks (5), a device for separating blanks (6) with blank locations and blank grippers for separating and transferring blanks from the blank stacks, an erecting device (7) for erecting blanks, a transfer unit (8) with transfer locations for transferring the erected blanks in the pitch of the cavities of a molding tool (10) or molding / punching tool (11) to a molding tool (10) or molding / punching tool (11), and a removal unit for removing the decorated molded parts from the molding tool (10) or molding / punching tool (11) of the thermoforming machine, characterized bythat the blank stacks (5) comprise at least two different types of blanks (1, 9), wherein the blanks (1, 9) have different contours and wherein the blanks (1, 9) are each placed in the blank stacks (5) such that they have a stacking pattern parallel to the longitudinal axis of the blank stacks (5) and wherein the stacking pattern represents an alternating sequence of the blanks (1, 9). [2] Device according to claim 1, characterized by that the blanks (1, 9) in the blank stacks (5) are connected to each other. [3] Device according to claim 2, characterized by that the blanks (1, 9) in the blank stacks (5) are connected to one another by a tearable perforation. [4] Device according to claim 1, characterized by that the magazine locations are equipped with interchangeable, modular magazine format parts (12). [5] Device according to claim 1, characterized bythat the erecting device (7) also assumes the task of shifting erected blanks from the pitch of the magazine to the pitch of the cavities of the forming tool (10) or forming / punching tool (11). [6] Device according to claim 1, characterized by in that the magazine (4) has a magazine plate (30) which, for fixing the blanks (1, 9), comprises both side pins (28) which have one contact surface with the blanks (1, 9), and corner pins (29) which have two contact surfaces with the blanks (1, 9). [7] Device according to claim 1, characterized by that the magazine (4) has a magazine plate (30) which, for fixing the blanks (1, 9), comprises exclusively side pins (28) which have a contact surface with the blanks (1, 9). [8] Device according to claim 1, characterized byin that the magazine (4) comprises a stripper plate (33) which, for stripping blanks (1, 9) which are not sucked in, has both side strippers (32) which have one stripper surface opposite the blanks (1, 9) and corner strippers (31) which have two stripper surfaces opposite the blanks (1, 9). [9] Device according to claim 1, characterized by that the magazine (4) comprises a stripper plate (33) which, for stripping blanks (1, 9) which are not sucked in, has exclusively side strippers (32) which have a stripping surface opposite the blanks (1, 9). [10] Device according to claim 1, characterized by that the device has first holding devices (38) for receiving and transporting first blanks (1) and second holding devices (39) for receiving and transporting second blanks (9). [11] Device according to claim 10, characterized bythat the holding devices (38, 39) are designed to be displaceable relative to one another. [12] Device according to claim 1, characterized by that the erecting device (7) has third holding devices (23) on the erecting devices (7) for erecting and holding the erected blanks (1, 9). [13] Device according to claim 1, characterized by that the erecting device (7) has preform shells (40) for erecting the blanks (1, 9). [14] Method for operating a device for decorating molded parts formed or formed and punched in a thermoforming machine from thermoplastic film, wherein the device separates blanks (1, 9) from the blank stacks (5) from a magazine (4) for storing blank stacks (5) and erects the blanks (1, 9), transfers them to a transfer unit (8) which transfers the erected blanks (1, 31) to a molding tool (10) or molding / punching tool (11) and a removal unit removes the decorated molded parts (17) from the molding tool (10) or molding / punching tool (11), characterized bythat the device for separating blanks (6) separates at least two different blanks (1, 9) from the blank stacks (5) in one work cycle and transfers them to a device for erecting (7), which erects the at least two blanks (1, 9), to a transfer unit (8), which transfers the at least two erected blanks (1, 9) to a forming tool (10) or forming / punching tool (11). [15] Method according to claim 14, characterized by that the erecting device (7) pushes the blanks (1, 9) together from the gauge of the magazine (4) to the gauge of the forming tool (10) or forming / punching tool (11). [16] Method according to claim 14, characterized by that a removal unit removes the decorated molded parts (17) from the molding tool (10) or molding / punching tool (11). [17] Method according to claim 14, characterized bythat first and second holding devices (38, 39) are spaced apart from one another and, in interaction with a movement of the device for separating blanks (6), erect the first and second blanks (1, 9). [18] Method according to claim 14, characterized by that further holding devices (23) on the erecting devices (7) erect the first and second blanks (1, 9). [19] Method according to claim 14, characterized by that the device for separating blanks (6) transfers the first and second blanks (1, 9) to the devices for erecting (7) in preform shells (40) in which the first and second blanks (1, 9) are at least partially erected. [20] Decorated molded part, produced by a process according to claims 14 to 19, consisting of a molded part (2) thermoformed from heated thermoplastic film with an edge (20) and a decorative portion, characterized byin that the decorative part consists of at least two blanks (1, 9), the first blank (1) being attached below the edge (20) and having a gap-free section below the edge (20), the first blank (1) being connected to the second blank (9) below the flange (26), and the blanks (1, 9) being permanently connected to the molded part (2), elevations (36) on the surfaces of the walls of the molded part (2) penetrating cutouts (37) which are made in the blanks (1, 9) in such a way that, after the plastic film of the molded part (2) has been formed, undercuts of the elevations (36) are produced relative to the cutouts (37). [21] Decorated molding according to claim 20, characterized by that the first blank (1) is connected to the second blank (9) by means of a perforation (13) at least in the blank stack (5).

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