Device for producing molded containers and for closing the molded containers in the correct position with closure elements

Abstract

Device for the cyclical production of packaging sections designed as shaped containers (1) from a continuous material strand (3), which has section designs, in particular imprints, for each packaging section to be produced, with a tool (4) for producing the shaped containers (1) and with a cutting device (11) for separating the shaped containers (1), which are each accommodated in a movement guide and are movable in the direction of movement of the material strand (3), characterized in that motor drives (9, 9') are assigned to the movement guides of the tool (4) and the cutting device (11), that at least one control device for the correct positional arrangement of the section designs on the material strand (3) is provided and that a device for changing the draw-off length of the material strand (3) is provided, wherein the control device, the device for changing the draw-off length and the motor drives (9,9') are interconnected via a controller (12).

Description

[0001] The invention relates to a device for the cyclical production of packaging sections from a continuous material strand, in particular of shaped containers, which has section designs, in particular imprints, for each packaging section to be produced,

[0002] Packaging is used to hold and package objects. It consists of various sections, such as a shaped container and a lidding film. Objects can be food items, such as slices of sausage or pieces of cheese, which are placed in shaped containers, for example, made of plastic, and sealed with a packaging section designed as a lidding film.

[0003] For such purposes, the molded containers typically feature sectioned designs, e.g., printing. Using a generic device, the actual molded containers, such as plastic trays, can be formed and sealed with lidding films after the product to be packaged has been inserted. Several molded containers are typically processed in a single work cycle; after the items have been inserted, they are covered with a common strand of lidding film. At a later point, the already sealed molded containers are separated from one another.

[0004] In known devices of the type mentioned above, tolerances arise during the regularly recurring printing of at least one material strand. This gives rise to the problem that the printing, for example on the lidding film, can no longer be applied precisely to the molded containers, resulting in unsightly print images and missing information for consumers of the packaged items. In the prior art, this is remedied by, for example, stretching the material strand of the closure elements in order to achieve congruent superimposition of the closure elements and molded containers. Even when printing molded containers, if the distances between the individual prints, for example, on the material for the molded containers, can result in the print running out of the molded containers.

[0005] However, the material of the forming strand for the lidding film and / or the forming container is often overstretched, which, for example, jeopardises the secure closure of the forming container.

[0006] The invention is based on the object of demonstrating a device of the type mentioned at the outset, with which a secure closing of the mold containers is possible, whereby a precise positional assignment of section design and mold container is ensured.

[0007] This object is achieved according to the invention in that at least one control device is provided for the correct positional arrangement of the section designs on the material strand, that the tool is accommodated in a movement guide and is movable in the direction of movement of the material strand and a device is provided for changing the withdrawal length of the material strand, wherein the control device, the movement guide of the tool and the device for changing the withdrawal length are interconnected via a control system.

[0008] With the device according to the invention, stretching a material strand is not necessary. Instead, the packaging sections are adapted to the specific design of the material strand. If a shift in the printing or other markings on a material strand occurs, the position of the packaging sections can be adjusted. To detect such a shift, the control device is provided for the correct positioning of the section design on the material strand. It can check whether the distances, for example, between the individual section designs are equal or whether deviations occur.

[0009] Such a deviation is transmitted to the tool's motion control system via the shared control system. According to the invention, the tool for molding is mounted movably and can be adjusted in the direction of the shifted printing. This ensures precise assignment of markings to molded containers or lidding films.

[0010] Since, for example, the molded containers are produced in a continuous material strand, the distance between the subsequent molded containers can be the same. When the first corrected molded container is introduced into a subsequent processing station, a correction is then made to the pull-off length of the material strand so that each molded container can enter the subsequent processing stations with an exact fit, for example in filling stations and in sealing stations for closing the containers with the closure elements.

[0011] If the inspection device detects a deviation between a section design on the material strand and the previous section design, an immediate adjustment should be made in response by changing the pull-off length of the material strand. However, this is not possible due to the cyclic processing of, for example, already formed molded containers, as these are still in a section between being formed and closed. A change in the pull-off length therefore only occurs once the detected deviation in the section designs has reached the next processing station. Until then, for each packaging section to be processed, the tool is shifted in its motion guide by an amount that corresponds to the detected error. In this way, a molded container or a lidding film is correctly assigned to the section designs.

[0012] The device according to the invention thus enables a delayed, continuous adjustment to errors in the section designs on continuous material strands. This prevents such errors from accumulating across multiple section designs. The change in the haul-off length takes place without stretching the material strands; it is done by eye, after previously manufactured molded containers or lidding films have been transferred to the next processing stage.

[0013] The position of a material strand is monitored by the device; a camera in the control unit can be used for this purpose. The motion guide is preferably a sliding guide, which allows the tool to be moved to produce the mold containers. A motor drive connected to a control system of the device is preferably assigned to the motion guide. Positional differences in a material strand recorded by the camera are processed by the control system and converted into a correction of the tool position for forming the mold containers.

[0014] After filling and closing the mold containers, they are separated from the material strand. A cutting device for separating the containers is preferably housed in a motion guide and can be moved toward the first material strand. This motion guide can also be a sliding guide with a motor drive associated with it, whereby this motor drive is also connected to the device's control system.

[0015] An embodiment of the invention, from which further inventive features emerge, is illustrated in the drawing. The sole figure of the drawing shows a schematic side view of an apparatus according to the invention for producing molded containers.

[0016] In the device according to the invention, shaped containers 1 are produced closed with a lidding film 2, the shaped containers 1 and the lidding film 2 forming packaging sections.

[0017] The mold containers 1 are deep-drawn from a first material strand 3 using a tool 4. The material strand 3 is, for example, a stable film, which can be provided with section designs, for example, printed ones. The prints are arranged on the material strand 3 such that one print is assigned to a mold container 1, preferably within its sloping walls in the area of ​​the bottom of the mold container 1.

[0018] During the production of the material strand 3, the manufacturer ensured that the section designs, i.e., the prints, were applied at equal spacing to the material strand 3, so that a section design can be successfully assigned to a mold container 1. A camera 10 checks whether the sections of the individual section designs are actually identical to one another. Any deviations detected are transmitted to a controller 12.

[0019] The controller 12 is connected to a motor drive for the tool 4. The tool 4 is the lower tool for a thermoforming device 5. It can be moved by the motor drive 9 along the double arrow 8 within a certain range in the direction of the conveyance of the first material strand 3.

[0020] If a deviation in the section design of the first material strand is detected, the motor drive 9 adjusts the tool 4 to this deviation. The draw-off length of the material strand 3 remains unchanged; however, for subsequent molded containers 1 to be produced, the tool 4 is moved again by the same amount in order to adapt the containers now being produced to the changed arrangement of the section designs. This continues until the first corrected molded container is placed in another tool, namely a sealing station 7. Only then is the draw-off length of the first material strand changed; the tool 4 remains in its current position.

[0021] A corresponding correction option can also be assigned to the cover films 2, namely a second material strand 6 for these cover films 2.

[0022] The second material strand 6 for lidding films 2 can, for example, be paper webs, particularly when medical products are to be packaged. A paper web cannot be stretched; in this case, only adjusting the position of the lidding film areas to the specific prints present on the second material strand 6 prevents such prints from leaking out of the correct position on the lidding films 2.

[0023] The mold containers 1, provided with closure elements 2, are separated from each other and from the first material strand 3 using a cutting device 11. A motor drive 9' is again assigned to the cutting device 11; the mobility of this cutting device 11 in the conveying direction of the first material strand 3 is indicated by the double arrow 8'. Like the tool 4, the cutting device must also be cyclically adjusted to the existing spacing of the mold containers 1. The cutting device 11 can only remain in its position after the arrival of the mold container 1 with the new spacing.

[0024] The device has a control system 12, with which the components drive 9, 9', camera 10 and a conveyor belt 13 for the first material strand 3 are connected.

Claims

[1] Device for the cyclical production of packaging sections designed as shaped containers (1) from a continuous material strand (3), which has section designs, in particular imprints, for each packaging section to be produced, with a tool (4) for producing the shaped containers (1) and with a cutting device (11) for separating the shaped containers (1), which are each accommodated in a movement guide and are movable in the direction of movement of the material strand (3), characterized bythat motor drives (9, 9') are assigned to the movement guides of the tool (4) and the cutting device (11), that at least one control device is provided for the correct positional arrangement of the section designs on the material strand (3), and that a device is provided for changing the pull-off length of the material strand (3), wherein the control device, the device for changing the pull-off length, and the motor drives (9, 9') are interconnected via a controller (12). [2] Device according to claim 1, characterized by that the control device for the correct positional arrangement comprises at least one camera (10). [3] Device according to claim 1 or 2, characterized by that the movement guide for the cutting device (11) is a sliding guide.

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