Packaging machine and method for vacuum cooling

Abstract

Packaging machine (100), which is in particular in the form of an intermittently operating thermoforming packaging machine (1), comprising at least one vacuum cooling device (3) with a plurality of vacuum cooling stations (16a, 16b) arranged one behind the other in the production direction (R) of the packaging machine (100), which are each configured to cool at least one product (P) received therein by generating a negative pressure, wherein the vacuum cooling device (3) has a lifting mechanism (17, 26) which is used jointly by the plurality of vacuum cooling stations (16a, 16b) for opening and closing them.

Description

[0001] The present invention relates to a packaging machine with a vacuum cooling device according to claim 1. Furthermore, the invention relates to a method for vacuum cooling products according to claim 15.

[0002] DE29607689U1 discloses a thermoforming packaging machine with a sealing station, which is followed in the transport direction by a mechanical cooling device which presses on sealed packages from above and below by means of cooling pads mounted thereon in order to cool them downstream of the sealing station after the sealing process.

[0003] JPS57-1021A discloses a thermoforming packaging machine with a forming station positioned at the beginning in the production direction for producing thermoforming trays, a sealing station for producing packaging and a vacuum station positioned between the forming station and the sealing station for removing moisture from products enclosed therein.

[0004] US2004 / 0105927A1 discloses a thermoforming packaging machine with a pasteurization station positioned upstream of a sealing station of the packaging machine in the production direction. Within the pasteurization station, incoming products can be heat-treated by applying steam. Optionally, a vacuum cooling process takes place following the pasteurization process.

[0005] EP4335759A2 discloses a thermoforming packaging machine with a vacuum cooling device positioned upstream of the sealing station along a filling line in the production direction. The machine cycle of such a thermoforming packaging machine, according to which work is carried out intermittently along the thermoforming packaging machine, is determined by the slowest process at a work station located thereon. Conventionally, the process taking place within the sealing station, which typically lasts 4 to 8 seconds, is used as the basis for determining the machine cycle.However, since vacuum cooling can take up to approximately 30 seconds in total to sufficiently cool hot products before the sealing process, it is necessary, taking into account the duration of a conventional machine cycle, to divide the vacuum cooling process into several stages so that the machine cycle of the thermoforming packaging machine, which usually starts from the sealing process, is not unnecessarily increased by the cooling process. The step-by-step implementation of the vacuum cooling process can be carried out using several consecutive vacuum cooling stations along the filling line of the thermoforming packaging machine. Typically, five to six consecutive vacuum cooling stations are required to cool a hot product in successive steps to a desired final temperature, assuming it only spends 4 to 8 seconds in each vacuum cooling station.However, the use of several vacuum cooling stations arranged in series increases the manufacturing costs due to the resulting structural complexity.

[0006] The object of the invention is to provide a packaging machine configured for vacuum cooling of products, which can be manufactured at reduced costs and in particular contributes to the reduction of packaging material, as well as a corresponding method.

[0007] This object is achieved by means of a packaging machine according to claim 1. Furthermore, this object is achieved by means of a method according to claim 15.

[0008] Advantageous further developments of the invention are given by the respective subclaims.

[0009] The invention relates to a packaging machine which is configured in particular in the form of an intermittently operating thermoforming packaging machine. The packaging machine according to the invention comprises at least one vacuum cooling device with a plurality of vacuum cooling stations arranged one behind the other in the production direction of the packaging machine, each of which is configured to cool at least one product accommodated therein by generating a negative pressure. According to the invention, the vacuum cooling device has a lifting mechanism which is used jointly by the plurality of vacuum cooling stations and for opening and closing them. The lifting mechanism thus forms a closing mechanism used by all vacuum cooling stations, by actuation of which the respective vacuum cooling stations can be opened and closed synchronously. This simplifies the design of the vacuum cooling device, thereby reducing manufacturing costs.

[0010] Because several vacuum cooling stations positioned one behind the other in the direction of production can be opened and closed using a common lifting mechanism, i.e., a single lifting mechanism, the lifting mechanism can be used multifunctionally at separate workstations. According to the invention, the lifting mechanism is thus functionally integrated into several successively positioned work cycles that move intermittently in the direction of production. This enables functional integration of the lifting mechanism at the vacuum cooling stations, because the same lifting mechanism can be used to open and close several vacuum cooling stations that are used in successive steps for vacuum cooling.The respective work cycles can, for example, have a packaging format consisting of several packaging bases formed in and / or transversely to the production direction, which, after completion of a machine work cycle, move further along the packaging machine by their format length, i.e. intermittently pass through the work stations formed thereon.

[0011] Preferably, the vacuum cooling stations form vacuum cooling chambers arranged one behind the other in the production direction, in which at least one product-laden packaging base can be accommodated. In particular, the respective vacuum cooling chambers can accommodate several lanes of packaging bases formed transversely to the production direction, and more particularly, several rows of packaging bases formed side by side in the production direction. For example, it would be advantageous for each vacuum cooling chamber to accommodate a format of 2x2, 2x4, 4x2, or 4x4 packaging bases per machine cycle.

[0012] An advantageous variant provides for the vacuum cooling chamber of the vacuum cooling station and the vacuum cooling chamber of a vacuum cooling station positioned behind it in the direction of production to be separated from each other by a wall running transversely to the direction of production, which is used jointly by these two to form the adjacent vacuum cooling chambers. This wall thus serves as the boundary of the respective vacuum cooling chambers and is thus used at both vacuum cooling stations. The wall is thus multifunctional and can form multiple vacuum cooling chambers, resulting in a simplified overall design.Because in this variant the vacuum cooling chambers of the vacuum cooling stations, which are positioned one behind the other in the direction of production and used separately for each machine work cycle, are at least partially delimited by the same wall, it is possible to provide a reduced wall thickness for this wall compared to a solution in which adjacent vacuum cooling chambers are separated from each other by separate walls. This has the positive effect of resulting in a more cost-effective construction of the vacuum cooling stations than in vacuum cooling stations whose vacuum cooling chambers are each formed or separated from each other by separate walls. Furthermore, the multifunctional use (functional integration) of the wall formed in this variant enables the gap between the respective pack formats to be reduced.This enables an overall shortened structure of the packaging machine and leads to reduced material consumption on a thermoforming packaging machine.

[0013] Preferably, the wall is formed by an upper tool part and / or a lower tool part for producing the respective vacuum cooling chambers. A particularly simplified design provides for the respective vacuum cooling stations to have tool parts located exclusively above the products moving along the packaging machine, which can be joined to the packaging lower parts in such a way that the respective vacuum cooling chambers are present between them. The packaging lower parts, for example, packaging trays, themselves are used as walls to define the vacuum cooling chambers, while the vacuum cooling chambers thus formed are evacuated via the tool part positioned above them.

[0014] It would be advantageous if the vacuum cooling device for closing the vacuum process chambers had a plate-shaped upper tool part. This design allows the upper tool part to be manufactured cost-effectively.

[0015] A preferred variant provides for the vacuum cooling device to have two to eight, in particular three to six, vacuum cooling stations. This allows vacuum cooling to be carried out step by step and, above all, makes it possible to use the vacuum cooling device, i.e., its step-by-step sequence of cooling steps, on a packaging machine whose machine cycle is defined by the sealing process, for example, lasting only 4 to 8 seconds.

[0016] According to one embodiment, the vacuum cooling device comprises a vacuum pump that is connected to each of the plurality of vacuum cooling stations for operation. The vacuum pump can thus be used by all vacuum cooling stations. This multifunctional use of the vacuum pump at multiple vacuum cooling stations also leads to a cost-reduced design.

[0017] It would be conceivable for at least one of the vacuum cooling stations to have a valve unit that is adjustable for setting a cooling volume flow generated by the vacuum pump at the vacuum cooling station. Preferably, a proportional control valve is used at the respective vacuum cooling stations to regulate a flow volume flow or a flow rate of the water vapor evacuated during vacuum cooling at the respective vacuum cooling stations, in particular such that it remains essentially constant, at least temporarily, during the evacuation.

[0018] According to one embodiment, it is provided that the valve unit(s) can be dynamically adjusted depending on a detected and / or preset duration of a machine working cycle of the packaging machine such that the products transported along the vacuum cooling device leave the vacuum cooling station of the vacuum cooling device, which is positioned last in the direction of production, with a desired core temperature.

[0019] The vacuum cooling device preferably has at least one temperature measuring unit configured to measure a product temperature. Such a temperature measuring unit can be structurally integrated, in particular, into the vacuum cooling station positioned first in the direction of production, particularly in its vacuum cooling chamber. Based on the product temperature thus detected at the inlet to the vacuum cooling station, the respective vacuum cooling processes of the vacuum cooling stations can be controlled so that products are cooled to a desired temperature level upon exiting the vacuum cooling device.

[0020] It would be possible for the packaging machine to have at least one additional vacuum cooling unit downstream of the vacuum cooling unit in the production direction, with multiple vacuum cooling stations and a lifting mechanism shared by all of them for opening and closing the vacuum cooling stations. The design of this vacuum cooling unit can be identical to the upstream vacuum cooling unit. If necessary, the additional vacuum cooling unit can be installed or removed from the packaging machine in the form of a mobile add-on module to increase or decrease the number of cooling steps.

[0021] An advantageous variant provides for a variable division of the vacuum cooling device along the production direction to adapt to the packaging base format to be processed per machine cycle. In other words, according to this variant, the storage volume of the respective vacuum cooling chambers can be varied. This can be achieved, for example, by means of an expansion kit available for the respective vacuum cooling stations, which allows the walls of the vacuum cooling chambers running in the production direction to be expanded by installing additional modules.

[0022] It would be expedient for the lifting mechanism to include a servomotor. This can be functionally connected to a control system on the packaging machine. The servomotor is preferably adjustable synchronously with other servomotors used for lifting movements on the packaging machine. For example, along the packaging machine, if the packaging machine is in the form of a thermoforming packaging machine, a forming station located at the input for thermoforming packaging bases, several vacuum cooling stations positioned downstream in the production direction, and the sealing station positioned further downstream can be opened and closed simultaneously using their respective lifting mechanisms.

[0023] According to an advantageous embodiment, the degree of functional integration of the lifting mechanism according to the invention could be increased by further using the lifting mechanism for opening and closing a forming station and / or sealing station of the packaging machine.

[0024] An advantageous embodiment provides for the lifting mechanism to have a lifting table on which the plurality of vacuum cooling stations are mounted. In this variant, the lifting mechanism is even functionally used for a variety of processes.

[0025] It would be conceivable for the vacuum cooling stations to be positioned directly behind one another in the direction of production. This would result in a particularly compact design for the vacuum cooling system, allowing it to be integrated structurally, especially into packaging machine types manufactured in different sizes.

[0026] It would be conceivable for the vacuum cooling device according to the invention to be integrated into the production process as an add-on module on various machine types, i.e., on different machine series. In particular, the vacuum cooling device can have a standardized design for use on different machine types.

[0027] The invention further relates to a method for vacuum cooling products along a packaging machine. According to the method according to the invention, several vacuum cooling stations arranged one after the other along the packaging machine in the production direction are opened and closed using a lifting mechanism shared by them. The lifting mechanism thus forms a multifunctional mechanism shared by the respective vacuum cooling stations to simplify the design of the packaging machine, in particular to reduce the number of cost-intensive components.

[0028] The products, in particular baked goods, preferably have a core temperature of less than 35°C after vacuum cooling, in particular between 18°C ​​and 25°C. Preferably, the product or baked good has a core temperature of at least 70°C, preferably at least 78°C, and more preferably at least 85°C, at the start of vacuum cooling in the vacuum cooling chamber.

[0029] The products can be cooled in particular during vacuum cooling by at least 5°C, preferably at least 10°C, preferably at least 15°C, preferably at least 20°C, preferably at least 25°C, preferably at least 30°C, preferably at least 35°C.

[0030] Embodiments of the invention are explained in more detail with reference to the following figures. They show: Fig. 1 a packaging machine in the form of a thermoforming packaging machine with a vacuum cooling device in a schematic side view, Fig. 2 the vacuum cooling device Fig. 1 in isolated, schematic representation, Fig. 3 a packaging machine in the form of a thermoforming packaging machine with a further vacuum cooling device in a schematic side view, and Fig. 4 a vacuum cooling device not according to the invention.

[0031] Identical components are provided with the same reference numerals throughout the figures.

[0032] Fig. 1 shows a schematic side view of a packaging machine 100 configured as an intermittently operating thermoforming packaging machine 1. This thermoforming packaging machine 1 has a forming station 2, a vacuum cooling device 3, a sealing station 4, a cross-cutting device 5, and a longitudinal cutting device 6, which are arranged in this order in a production direction R on a machine frame 7. On the input side, a feed roll is located on the machine frame 7, from which a film web 8 is pulled off as a bottom film. Furthermore, the thermoforming packaging machine 1 has a transport chain 9, which grips the film web 8 and transports it further in the production direction R for each main work cycle.

[0033] In the illustrated embodiment, the forming station 2 is designed as a deep-drawing station in which troughs M are formed in the film web 8 by deep drawing, for example by means of compressed air and / or vacuum. The forming station 2 can be designed such that a plurality of troughs M are formed next to one another in the direction perpendicular to the production direction R. In the production direction R behind the forming station 2, a filling section or an insertion area 10 is provided, at which the troughs M formed in the film web 8 are filled with products P. The filling of the troughs M with products P can be carried out by a picker 11 or by means of a conveyor belt. In particular, hot products P, for example baked dough products, can be inserted into the troughs M.

[0034] The Fig. 1 Sealing station 4 positioned downstream of the vacuum cooling device 3 in the production direction R has a hermetically sealable chamber 4a in which the atmosphere in the troughs M can be evacuated, for example, and / or replaced by gas purging with a replacement gas or with a gas mixture before sealing with a film web 13 delivered from an upper film holder 12.

[0035] The cross-cutting device 5 can be designed as a punch that cuts the sealed film webs 8, 13 in a direction transverse to the production direction R between adjacent troughs M. The cross-cutting device 5 operates in such a way that the film web 8 is not cut across its entire width, but rather remains uncut at least in one edge area. This enables controlled further transport through the transport chain 9.

[0036] The longitudinal cutting device 6 can be designed as a knife device with which the sealed film webs 8, 13 are severed in the production direction R between adjacent troughs M and at the lateral edge of the film web 8 formed as the bottom film, so that individual packages X are present behind the longitudinal cutting device 6.

[0037] The thermoforming packaging machine 1 also has a control device 14. Its task is to control and monitor the processes taking place in the thermoforming packaging machine 1. A display device 15 serves to visualize or influence the processes in the thermoforming packaging machine 1 for or by an operator.

[0038] According to Fig. 1, the vacuum cooling device 3 has two vacuum cooling stations 16a, 16b arranged one behind the other in the production direction R. The vacuum cooling stations 16a, 16b from Fig. 1 are each configured to cool at least one product P contained therein by creating a vacuum V. This is achieved by removing water vapor from the respective product P through the created vacuum V, thereby cooling it.

[0039] According to Fig. 1, the vacuum cooling device 3 and the sealing station 4 are designed as separate stations.

[0040] Fig. 2 shows a schematic representation of the vacuum cooling device 3 from Fig. 1 isolated. Fig. 2 shows that the vacuum cooling device 3 has a lifting mechanism 17 which is used jointly by the two vacuum cooling stations 16a, 16b for opening and closing them.

[0041] The vacuum cooling stations 16a, 16b form vacuum cooling chambers 18a, 18b one after the other in the production direction R, in each of which at least one packaging base 19 loaded with product P can be received in the form of a trough M. According to Fig. 2, two troughs M formed one behind the other in the direction of production are accommodated in the respective vacuum cooling chambers 18a, 18b.

[0042] Furthermore, Fig. 2, that at the vacuum cooling stations 16a, 16b, the vacuum cooling chambers 18a, 18b arranged adjacent to one another in the production direction have a common wall 20 by which they are separated from one another. Because the wall 20 serves both to delimit the vacuum cooling chamber 18a and to delimit the vacuum cooling chamber 18b positioned behind it in the production direction R, it is possible to make the wall thickness w of the wall 20 relatively thin, whereby a distance a of the film material between the work cycle recorded in the vacuum cooling chamber 18a and the work cycle recorded in the vacuum cooling chamber 18b can be made relatively short. This allows the consumption of film material to be kept low.

[0043] Fig. 2 further shows, in a schematic representation, that the vacuum cooling device 3 has a vacuum pump 21, which is connected to each of the two vacuum cooling stations 16a, 16b for operation, i.e., is used by both as a vacuum source. A valve unit 22 is arranged between the vacuum pump 21 and the vacuum cooling chamber 18a, which is adjustable for setting a cooling volume flow generated by the vacuum pump 21 at the vacuum cooling station 16a. The valve unit 22 can, in particular, be an integral component of a dynamic control device. A functionally comparable valve unit 23 is provided between the vacuum pump 21 and the vacuum cooling chamber 18b of the vacuum cooling station 16b.

[0044] According to Fig. 2, the vacuum cooling device 3 has a plurality of temperature detection units 24 configured to measure a product temperature T. Based on this, a dynamic control of the respective valve units 22, 23 and / or the operation of the vacuum pump 21 could be carried out in order to generate a desired pressure level within the respective vacuum cooling chambers 18a, 18b.

[0045] According to Fig. 2, the vacuum cooling device 3 is configured for a package format F consisting of two packaging bases 19 arranged one behind the other in the production direction R. However, the package format F and thus also the division of the vacuum cooling device 3 can vary.

[0046] According to Fig. 2, the vacuum cooling stations 16a, 16b are mounted on a common lifting table 25. This lifting table 25 can be moved by the lifting mechanism 17, taking into account a machine work cycle of the thermoforming packaging machine 1 from Fig. 1 can be adjusted in height in order to open and close the vacuum cooling chambers 18a, 18b together.

[0047] Fig. Figure 3 shows a thermoforming packaging machine 1 in which the vacuum cooling device 3 and the sealing station 4 are positioned directly behind one another. In a schematic representation, Fig. 3 shows that both the vacuum cooling device 3, i.e. the two vacuum cooling stations 16a, 16b provided thereon, and the sealing station 4 have a lifting mechanism 26 which is used jointly for opening and closing.

[0048] Further shows Fig. 3 schematically shows that the vacuum cooling chamber 18b of the vacuum cooling station 16b is separated from the sealing chamber 4a by a wall 27 shared by both chambers 4a, 18b. Here, too, a reduced wall thickness can be formed for the wall 27 in order to minimize the format separation of successive work cycles according to the distance a.

[0049] Fig. 4 shows a construction of a vacuum cooling device 3' not according to the invention. In this vacuum cooling device 3', the respective vacuum cooling stations 16a', 16b' each have separate lifting mechanisms 28, 29 as well as separately designed lifting tables 30, 31 and also separately designed chamber walls 32, 33 for forming the respective vacuum cooling chambers 18a', 18b'. Furthermore, the vacuum cooling stations 16a', 16b' comprise Fig. 4 no plate-shaped tool upper part in integral construction according to Fig. 2, but separate tool upper parts. This results in Fig. 4 compared to the construction of Fig. 2 a structurally more complex design that requires energy-intensive operation.

[0050] With the structure of Fig. 4, ie because of the separate design of the respective walls 32, 33, it is accompanied by a wall thickness w' being thicker than the wall thickness w from Fig. 2, so that between the pack formats F of the work cycles recorded in the vacuum cooling stations 16a', 16b' there is a larger distance a' than the distance a from Fig. 2 is necessary. This leads to increased consumption of packaging material.

Claims

[1] Packaging machine (100), which is in particular in the form of an intermittently operating thermoforming packaging machine (1), comprising at least one vacuum cooling device (3) with a plurality of vacuum cooling stations (16a, 16b) arranged one behind the other in the production direction (R) of the packaging machine (100), each of which is configured by generating a negative pressure for cooling at least one product (P) accommodated therein, characterized by that the vacuum cooling device (3) has a lifting mechanism (17) used jointly by the plurality of vacuum cooling stations (16a, 16b) for opening and closing them. [2] Packaging machine according to claim 1, characterized by that the vacuum cooling stations (16a, 16b) form vacuum cooling chambers (18a, 18b) one behind the other in the production direction (R), in which at least one packaging base (19) loaded with product (P) can be accommodated. [3] Packaging machine according to claim 2, characterized bythat adjacent vacuum cooling chambers (18a, 18b) at the vacuum cooling stations (16a, 16b) are separated from one another by a wall (20) which is used jointly to form the adjacent vacuum cooling chambers (18a, 18b) and which runs transversely to the production direction (R). [4] Packaging machine according to claim 2 or 3, characterized by that the vacuum cooling device (3) for closing the vacuum cooling chambers (18, 18b) has a plate-shaped tool upper part (35). [5] Packaging machine according to one of the preceding claims, characterized by that the vacuum cooling device (3) has two to eight, in particular three to six, vacuum cooling stations (16a, 16b). [6] Packaging machine according to one of the preceding claims, characterized by that the vacuum cooling device (3) has a vacuum pump (21) which is connected to the plurality of vacuum cooling stations (16a, 16b) for operating them. [7] Packaging machine according to claim 6, characterized by that at least one of the vacuum cooling stations (16a, 16b) has a valve unit (22) which is adjustable for setting a cooling volume flow generated by means of the vacuum pump (21) at the vacuum cooling station (16a, 16b). [8] Packaging machine according to claim 7, characterized by that the valve unit (22) is dynamically adjustable depending on a detectable duration of a machine working cycle of the packaging machine (100) such that the products (P) transported along the vacuum cooling device (3) leave the vacuum cooling station (16b) of the vacuum cooling device (3), which is positioned last in the production direction (R), with a desired product temperature. [9] Packaging machine according to one of the preceding claims, characterized by that the vacuum cooling device (3) has at least one temperature measuring unit (24) which is configured to measure a product temperature (T). [10] Packaging machine according to one of the preceding claims, characterized by that the packaging machine (100) has at least one further vacuum cooling device (3) arranged downstream of the vacuum cooling device (3) in the production direction (R), with a plurality of vacuum cooling stations (16a, 16b) and a lifting mechanism (17) used jointly by the vacuum cooling stations (16a, 16b) for opening and closing them. [11] Packaging machine according to one of the preceding claims, characterized by that a division of the vacuum cooling device (3) along the production direction (R) can be varied in adaptation to a format (F) of packaging bases (19) to be processed per machine work cycle. [12] Packaging machine according to one of the preceding claims, characterized by that the lifting mechanism (17) comprises a servo motor. [13] Packaging machine according to one of the preceding claims, characterized bythat the lifting mechanism (17) has a lifting table (25) on which the plurality of vacuum cooling stations (16a, 16b) are mounted. [14] Packaging machine according to one of the preceding claims, characterized by that the vacuum cooling stations (16a, 16b) are arranged directly one behind the other in the production direction (R). [15] Method for cooling products along a packaging machine, characterized by that several vacuum cooling stations (16a, 16b) arranged one behind the other along the packaging machine (100) in the production direction (R) are opened and closed by means of a lifting mechanism (17) used jointly by them.

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