Packaging machine and method for vacuum cooling

Abstract

Packaging machine (100), 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 configured by generating a vacuum to cool at least one product (P) contained therein, wherein the vacuum cooling device (3) has a lifting mechanism (17, 26) used jointly by the plurality of vacuum cooling stations (16a, 16b).

Description

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

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

[0003] JPS57-1021A discloses a thermoforming packaging machine with a forming station positioned 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 to remove moisture from enclosed products.

[0004] US2004 / 0105927A1 discloses a thermoforming packaging machine with a pasteurization station positioned upstream of a sealing station in the production direction of the packaging machine. Products arriving at the pasteurization station can be heat-treated by means of 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 time of such a thermoforming packaging machine, according to which work is carried out intermittently along the machine, is determined by the slowest process of a workstation integrated into it. Conventionally, the process occurring within the sealing station, which typically lasts 4 to 8 seconds, is used as the basis for determining the machine cycle time.However, since vacuum cooling can take up to approximately 30 seconds to sufficiently cool hot products before the sealing process, it is necessary, considering the duration of a conventional machine cycle, to divide the vacuum cooling process into several stages. This prevents the machine cycle of the thermoforming packaging machine, which typically begins with the sealing process, from being unnecessarily increased by the cooling process. The stepwise execution of the vacuum cooling process can be achieved using several vacuum cooling stations in succession along the filling line of the thermoforming packaging machine. Typically, five to six consecutive vacuum cooling stations are required to cool a hot product to the desired final temperature in successive steps, assuming it remains in each vacuum cooling station for only 4 to 8 seconds.However, the use of several vacuum cooling stations in series increases manufacturing costs due to the associated design complexity.

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

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

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

[0009] The invention relates to a packaging machine, which is configured in particular as an intermittently operating thermoforming packaging machine. The packaging machine according to the invention comprises at least one vacuum cooling unit 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 contained therein by generating a vacuum. According to the invention, the vacuum cooling unit has a lifting mechanism used by the plurality of vacuum cooling stations for opening and closing them. The lifting mechanism thus forms a closing mechanism used by all vacuum cooling stations, by means of which the respective vacuum cooling stations can be opened and closed synchronously. This simplifies the design of the vacuum cooling unit, thereby reducing manufacturing costs.

[0010] Because several vacuum cooling stations positioned one after the other in the production direction 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 at several workstations positioned one after the other, which are used to process different work cycles that move intermittently in the production direction. 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 for vacuum cooling in successive steps.The respective work cycles can, for example, have a packaging format consisting of several packaging sub-parts formed in and / or across the production direction, which each move along the packaging machine by their format length after the completion of a machine work cycle, i.e., intermittently pass through the work stations formed on it.

[0011] Preferably, the vacuum cooling stations form vacuum cooling chambers one after the other in the production direction, in which at least one packaging base loaded with product can be accommodated. In particular, several tracks of packaging bases arranged transversely to the production direction, and furthermore, several rows of packaging bases arranged side by side in the production direction, can be accommodated in the respective vacuum cooling chambers. It would be advantageous, for example, if each vacuum cooling chamber could accommodate a format of 2x2, 2x4, 4x2, or 4x4 packaging bases per machine cycle.

[0012] One advantageous variant involves separating the vacuum cooling chamber of the vacuum cooling station and the vacuum cooling chamber of a vacuum cooling station positioned downstream in the production direction by a wall running perpendicular to the production direction. This wall is used by both stations to form the adjacent vacuum cooling chambers. It thus serves as the boundary for the respective vacuum cooling chambers and is therefore used in both vacuum cooling stations. The wall is thus multifunctional, creating multiple vacuum cooling chambers and resulting in a simplified overall design.In this variant, the vacuum cooling chambers of the vacuum cooling stations, positioned one behind the other in the production direction and used separately for each machine cycle, are at least partially bounded by the same wall. This allows for a reduced wall thickness compared to a solution where adjacent vacuum cooling chambers are separated by separate walls. This has the positive effect of resulting in a more cost-effective design for the vacuum cooling stations than in vacuum cooling stations where each vacuum cooling chamber is formed or separated by separate walls. Furthermore, the multifunctional use (functional integration) of the wall in this variant allows for a reduction in the gap between the respective packaging formats.This allows for an overall shorter design of the packaging machine and leads to reduced material consumption on a thermoforming packaging machine.

[0013] Preferably, the wall is formed by a tool upper part and / or a tool lower part, both of which can be used to produce the respective vacuum cooling chambers. A particularly simplified design provides that the respective vacuum cooling stations have tool parts located exclusively above the products moving along the packaging machine. These tool parts can be joined with the packaging lower parts in such a way that the respective vacuum cooling chambers are situated between them. The packaging lower parts, for example, packaging trays, themselves serve as the wall to define the boundaries of the vacuum cooling chambers, while evacuation of the vacuum cooling chambers thus formed occurs 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 section. In this design, the upper tool section can be manufactured cost-effectively.

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

[0016] According to one embodiment, the vacuum cooling system includes a vacuum pump that is connected to each of the multiple vacuum cooling stations for operation. The vacuum pump can thus be used by all vacuum cooling stations. This multifunctional use of the vacuum pump across several vacuum cooling stations also results in 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 to regulate the cooling volume flow generated by the vacuum pump at the vacuum cooling station. Preferably, a proportional control valve is used at each vacuum cooling station to regulate the flow rate of the water vapor evacuated during vacuum cooling, in particular such that this flow rate remains essentially constant, at least temporarily, during evacuation.

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

[0019] Preferably, the vacuum cooling system has at least one temperature measuring unit configured to measure product temperature. Such a temperature measuring unit can be structurally integrated, in particular, into the vacuum cooling station positioned first in the production direction, especially within its vacuum cooling chamber. Based on the product temperature measured at the inlet of 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 at the outlet of the vacuum cooling system.

[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. This additional unit would have several vacuum cooling stations and a lifting mechanism shared by these stations for opening and closing them. The design of this additional vacuum cooling unit could be identical to that of the upstream vacuum cooling unit. If necessary, the additional vacuum cooling unit could be attached to or detached from the packaging machine as a mobile add-on module to increase or decrease the number of cooling steps.

[0021] One advantageous variant provides for a variable division of the vacuum cooling unit along the production direction to accommodate the format of packaging components to be processed per machine cycle. In other words, this variant allows the capacity of the individual vacuum cooling chambers to 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 extended by installing additional modules.

[0022] It would be advantageous for the lifting mechanism to include a servo motor. This can be functionally connected to a control system on the packaging machine. Preferably, the servo motor is synchronously adjustable with other servo motors used for lifting movements on the packaging machine. For example, if the packaging machine is a thermoforming packaging machine, an upstream forming station for thermoforming packaging bases, several vacuum cooling stations positioned downstream in the production direction, and the sealing station further downstream can be opened and closed simultaneously by means of 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 making the lifting mechanism also usable for opening and closing a forming station and / or sealing station of the packaging machine.

[0024] An advantageous embodiment provides that the lifting mechanism has a lifting table on which the multiple vacuum cooling stations are mounted. In this variant, the lifting mechanism can even be used functionally for various different processes.

[0025] It would be conceivable to arrange the vacuum cooling stations directly one behind the other in the production direction. This results in a particularly compact design for the vacuum cooling unit, making it easier to integrate into packaging machines of varying sizes.

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

[0027] Furthermore, the invention 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 by means of a lifting mechanism used jointly by them. The lifting mechanism thus forms a multifunctional mechanism that is used jointly by the respective vacuum cooling stations to simplify the design of the packaging machine, in particular to reduce costly components.

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

[0029] The products can be cooled 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, particularly during vacuum cooling.

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

[0031] Identical components are consistently labelled with the same reference symbols in the figures.

[0032] Figure 1Figure 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 unit 3, a sealing station 4, a cross-cutting unit 5, and a longitudinal cutting unit 6, arranged in this order along a machine frame 7 in a production direction R. On the inlet side of the machine frame 7 is a feed roller from which a film web 8 is unwound as the bottom film. Furthermore, the thermoforming packaging machine 1 has a transport chain 9 that grips the film web 8 and transports it along the production direction R for each main work cycle.

[0033] In the illustrated embodiment, the forming station 2 is designed as a thermoforming station in which cavities M are formed in the film web 8 by thermoforming, for example, using compressed air and / or vacuum. The forming station 2 can be configured such that several cavities M are formed side by side in the direction perpendicular to the production direction R. Downstream of the forming station 2 in the production direction R, a filling section or insertion area 10 is provided, where the cavities M formed in the film web 8 are filled with products P. The filling of the cavities 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 placed into the cavities M.

[0034] The in Figure 1The 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 recesses M can be evacuated and / or replaced by gas purging with a replacement gas or with a gas mixture before sealing with a film web 13 dispensed from an upper film receiver 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 at least in one edge area remains intact. This allows for controlled onward transport through the conveyor chain 9.

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

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

[0038] According to Figure 1 The vacuum cooling unit 3 has two vacuum cooling stations 16a and 16b arranged one behind the other in the production direction R. The vacuum cooling stations 16a and 16b are made of Figure 1Each unit is configured to cool at least one product P contained within it by generating a vacuum V. This occurs because the generated vacuum V allows water vapor to be extracted from the respective product P, thus cooling it.

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

[0040] Figure 2 schematically shows the vacuum cooling device 3. Figure 1 isolated. Figure 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 Figure 2In the respective vacuum cooling chambers 18a, 18b, two troughs M formed one behind the other in the production direction are included.

[0042] Furthermore, it shows Figure 2 The vacuum cooling stations 16a and 16b have adjacent vacuum cooling chambers 18a and 18b in the production direction, sharing a common wall 20 that separates them. Because the wall 20 serves to delimit both vacuum cooling chamber 18a and vacuum cooling chamber 18b, which is positioned behind it in the production direction R, it is possible to make the wall thickness w of the wall 20 relatively thin. This allows for a relatively short distance a of the film material between the work cycle in vacuum cooling chamber 18a and the work cycle in vacuum cooling chamber 18b. This minimizes the consumption of film material.

[0043] Figure 2Figure 3 further shows, schematically, that the vacuum cooling device 3 has a vacuum pump 21, which is connected to each of the two vacuum cooling stations 16a and 16b for operation, i.e., it 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 to regulate the cooling volume flow generated at the vacuum cooling station 16a by the vacuum pump 21. The valve unit 22 can, in particular, be an integral part 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 Figure 2The vacuum cooling unit 3 has several temperature sensing units 24 configured to measure a product temperature T. Based on this, dynamic control of the respective valve units 22, 23 and / or the operation of the vacuum pump 21 could be carried out to generate a desired pressure level within the respective vacuum cooling chambers 18a, 18b.

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

[0046] According to Figure 2 The vacuum cooling stations 16a and 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 cycle of the thermoforming packaging machine 1. Figure 1height adjustment is required to open and close the vacuum cooling chambers 18a and 18b together.

[0047] Figure 3 Figure 1 shows a thermoforming packaging machine 1 in which the vacuum cooling unit 3 and the sealing station 4 are positioned directly one behind the other. The schematic representation is shown in... Figure 3 shown 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 that is used jointly for opening and closing them.

[0048] Furthermore, it shows Figure 3 In a schematic representation, 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 and 18b. Here too, a reduced wall thickness can be used for the wall 27 in order to minimize the format division of successive work cycles according to the distance a.

[0049] Figure 4 Figure 1 shows a non-inventive design of a vacuum cooling device 3'. 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' are made of Figure 4 no plate-shaped tool upper part in integral construction according to Figure 2 , but rather separate tool tops. This results in Figure 4 compared to the construction method Figure 2 a more complex construction method that requires energy-intensive operation.

[0050] With the structure made of Figure 4 , i.e., because of the separate construction of the respective walls 32, 33, it follows that one wall thickness w' is thicker than the wall thickness w from Figure 2, so that between the packaging formats F of the work cycles recorded in the vacuum cooling stations 16a', 16b' there is a greater distance a' than the distance a from Figure 2 This is necessary. This leads to an increased consumption of packaging material.

Claims

1. Packaging machine (100), 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 configured by generating a vacuum to cool at least one product (P) contained therein, characterized by the fact that the vacuum cooling device (3) has a lifting mechanism (17) for opening and closing the plurality of vacuum cooling stations (16a, 16b) used jointly by these.

2. Packaging machine according to claim 1, characterized by the fact that The vacuum cooling stations (16a, 16b) form vacuum cooling chambers (18a, 18b) in the production direction (R) in succession, in which at least one packaging base (19) loaded with product (P) can be accommodated.

3. Packaging machine according to claim 2, characterized by the fact thatThe vacuum cooling chambers (18a, 18b) formed adjacent to the vacuum cooling stations (16a, 16b) are separated from each other by a wall (20) running transversely to the production direction (R) which is used jointly by them to form the adjacent vacuum cooling chambers (18a, 18b).

4. Packaging machine according to claim 2 or 3, characterized by the fact 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 the fact that the vacuum cooling device (3) comprises 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 the fact that the vacuum cooling device (3) comprises a vacuum pump (21) which is connected to each of the plurality of vacuum cooling stations (16a, 16b) for the operation of these.

7. Packaging machine according to claim 6, characterized by the fact thatat least one of the vacuum cooling stations (16a, 16b) has a valve unit (22) which is adjustable to set a cooling volume flow generated by the vacuum pump (21) at the vacuum cooling station (16a, 16b).

8. Packaging machine according to claim 7, characterized by the fact that The valve unit (22) is dynamically adjustable as a function of a detectable duration of a machine work 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 at the last position in the production direction (R), at a desired product temperature.

9. Packaging machine according to one of the preceding claims, characterized by the fact that the vacuum cooling device (3) has at least one temperature measuring unit (24) configured to measure a product temperature (T).

10. Packaging machine according to one of the preceding claims, characterized by the fact that the packaging machine (100) in the production direction (R) has at least one further vacuum cooling device (3) downstream of the vacuum cooling device (3) with several 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 the fact that The division of the vacuum cooling device (3) along the production direction (R) can be varied to adapt 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 the fact that the lifting mechanism (17) includes a servo motor.

13. Packaging machine according to one of the preceding claims, characterized by the fact thatthe lifting mechanism (17) has a lifting table (25) on which the multitude of vacuum cooling stations (16a, 16b) are mounted.

14. Packaging machine according to one of the preceding claims, characterized by the fact that the vacuum cooling stations (16a, 16b) are stored directly one behind the other in the production direction (R).

15. Method for cooling products along a packaging machine, characterized by the fact that Several vacuum cooling stations (16a, 16b) arranged one behind the other along the packaging machine (100) in the production direction (R) can be opened and closed by means of a lifting mechanism (17) used jointly by them.

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