PACKAGING MACHINE AND METHOD FOR PRODUCING EVACUATED AND/OR GASSED PACKAGINGS

Abstract

The invention relates to a packaging machine (1), comprising a deep-drawing station (2), which forms packaging wells in a material web (8), and a sealing station (19), which bonds a top material web to the material web, wherein before the bonded connection the packaging well is degassed and/or gassed, and a cutting unit, which separates the packagings thus produced from the material webs. The invention further relates to a method for producing a packaging, in which a material web is transported in cycles along a packaging machine, and during each cycle one or more packaging wells are formed in the material web and the packaging well is then filled with a product to be packaged, and then a cover film is sealed onto the packaging well, wherein before sealing a vacuum is drawn and/or a gas exchange is carried out in the packaging well.

Description

The present invention relates to a packaging machine, comprising a thermoforming station, which forms packaging wells in a material web, and a sealing station, which integrally bonds an upper material web to the material web, wherein, prior to the integral bond being made, the packaging well is degassed and/or gassed, and a cutting device, which separates the packagings thus produced from the material webs. Furthermore, the present invention relates to a method for producing a packaging, in which a material web is transported cyclically along a packaging machine and, during each cycle, one or more packaging wells is/are formed in the material web and the packaging well is then filled with a product to be packaged, and a cover film is then sealed onto the packaging well, wherein, prior to the sealing operation, a vacuum is drawn and/or a gas exchange is carried out in the packaging well.

In order to extend the shelf life of a packaged foodstuff, in particular a foodstuff containing protein, the packaging wells are often evacuated before being closed by a cover film, that is to say the air located in the packaging wells is removed and, where necessary, is replaced by an exchange gas. This exchange gas may be, for example, nitrogen, carbon dioxide, argon and/or oxygen or a mixture thereof or of other gases. Nowadays, ever-increasing demands with regard to efficiency, that is to say the number of packagings produced per minute, are placed on packaging machines and on packaging methods that can produce packagings which are evacuated or provided with an exchange gas in this way.

The object of the present invention was therefore to provide a packaging machine and a method for producing a packaging, in which an evacuation or a gas exchange in the packaging is possible, but in which very high cycle numbers can also be achieved.

The object is achieved by a packaging machine comprising a thermoforming station, which forms packaging wells in a material web, and a sealing station, which integrally bonds an upper material web to the material web, wherein, prior to the integral bond being made, the packaging well is degassed and/or gassed, and a cutting device, which separates the packagings thus produced from the material webs, wherein the packaging machine has a gas-storage and/or vacuum-storage volume provided in the region of the packaging machine.

The present invention relates to a packaging machine. This packaging machine is preferably what is known as an FFS packaging machine, that is to say what is known as a form-fill-seal packaging machine.

With a packaging machine of this type, a packaging well is formed in a material web, generally a plastic film web, for example by means of thermoforming, and, once the packaging well has been filled, is closed in a sealing station with an upper material web, which is generally likewise a plastic film web. Here, the upper material web is integrally bonded, in particular by means of sealing, to the lower material web. Prior to this connection being made, the packaging well is now degassed and/or gassed in accordance with the invention, wherein, in the case of the degassing process, a certain vacuum, than is to say a certain negative pressure, is generated in the packaging well. In the event of a gassing process, a gas exchange takes place in the packaging well, that is to say the packaging well is replaced at least in part by an exchange gas. This gas exchange may follow a degassing of the packaging well. The exchange gas may be, for example, nitrogen, carbon dioxide, argon and/or oxygen or a mixture thereof or of other gases.

Once the upper material web has been arranged in an integrally bonded manner on the lower material web, the packagings thus finished are then separated.

In accordance with the invention, a gas-storage and/or vacuum-storage volume is now located in the region of the packaging machine. This storage volume may be, for example, a tank and/or pipelines and/or pockets and/or cross-sectional extensions, matched appropriately to the desired volume, within the sealing tools. Since this gas-storage and/or vacuum-storages volume is provided in the region of the packaging machine, preferably in the direct vicinity of the packaging well to be degassed and/or gassed, the individual packaging wells can be degassed and/or gassed much more quickly than in the prior art. The number of cycles of the packaging machine can thus be increased.

The packaging machine according to the invention generally has a frame, on which the forming station, the sealing station and/or the separating station is/are mounted, preferably displaceably, for example. The gas-storage volume and/or vacuum-storage volume is/are preferably provided within the frame of the packaging machine, such that the path between this volume and the sealing station, within which the vacuum is generally drawn or the gas exchange is carried out, is as short as possible. The flow resistance in the line between the volume and the degassing and/or gassing point is particularly preferably also low. The desired negative pressure in the packaging well and/or the gas exchange can be implemented very quickly by means of one or more of these measures.

The machine is preferably a machine that operates cyclically. With a machine of this type operating cyclically, a packaging well or a pattern consisting of a plurality of packaging wells is transported intermittently along the packaging machine from one processing station to the next. During the actual processing steps, that is to say for example during the forming of the packaging well in the lower material web, the filling of the packaging well, the degassing and/or gassing of the packaging well, and/or the sealing of the upper material web onto the lower material web, the respective packaging wells are stationary. The gas-storage and/or vacuum-storage volume is/are now preferably dimensioned, at least in terms of volume, such that it has, respectively, a gas volume or vacuum volume required for one cycle. This volume is then available at very short notice for the degassing and/or gassing, such that the degassing and/or gassing of the packaging well can take place substantially more quickly than in packaging machines according to the prior art.

In a preferred embodiment, the packaging machine has a gassing means and/or a degassing means. These means may be, for example, a nozzle, by means of which air is removed from the packaging wells and/or the exchange gas is blown into the packaging wells.

The gassing means and the degassing means preferably constitute one structural unit.

In a further preferred embodiment of the present invention, the packaging machine has controller, by means of which the quantity of the fed gas and/or the extent of the vacuum, that is to say of the negative pressure, in the packaging well can be controlled. Should this negative pressure be insufficient for example, air thus continues to be drawn until this negative pressure is reached.

The present invention further relates to a method for producing a packaging, in which a material web is transported cyclically along a packaging machine and, during each cycle, one or more packaging wells is/are formed in the material web and the packaging well is then filled with a product to be packaged, and an upper material web is then sealed onto the packaging well, wherein, prior to the sealing operation, a vacuum is drawn and/or a gas exchange is carried out in the packaging well and the vacuum required for one cycle is established, at least substantially, before the packaging well is degassed.

The statements made with regard to the packaging machine according to the invention apply equally to the method according to the invention, and vice versa.

In accordance with the invention, the volume required for one cycle is then established, at least substantially, before the packaging well is degassed. For example, in the vicinity of the packaging machine, a certain negative pressure can be applied to a container having a certain volume before the packaging well is actually degassed. This container is then opened suddenly, for example by means of a valve, and sucks in a predefined quantity of gas until the desired pressure has been established in the packaging well. In contrast to a packaging machine in which the degassing process is carried out only by a vacuum pump, this procedure according to the invention is much quicker.

The packaging well can be filled with an exchange gas at the same time or subsequently. As soon as the evacuation of the packaging well is complete, a negative pressure is then again applied to this container, wherein the connection between the container and the degassing means, for example the degassing nozzle, is then closed. This connection is then opened again at the earliest when the intended negative pressure is present in the container.

In accordance with a further or a preferred aspect of the method according to the invention, at least, the majority of the gas and/or vacuum volume required for one cycle is already provided in the region of the packaging machine during the sealing and/or during the transport of the material web. The number of cycles of the method according to the invention is thus likewise increased, because the required gas volume and/or vacuum volume is/are already available when the next packaging well or the next pattern is to be evacuated and/or gassed.

The quantity of gas that is to be filled into a packaging well or the negative pressure that is to be achieved in a packaging well is preferably controlled. This control process is preferably carried out in accordance with the filling capacity of the packaging well.

The inventions will be explained hereinafter with reference to FIGS. 1 to 5. These explanations are merely exemplary and do not limit the general concept of the invention. The explanations apply equally to all aspects of the present invention.

FIG. 1 shows the packaging machine according to the invention.

FIG. 2 shows a first arrangement of the degassing and/or gassing means.

FIG. 3 shows a second arrangement of the degassing and/or gassing means.

FIG. 4 shows a schematic view of a further embodiment of the packaging machine according to the invention.

FIG. 5 shows a further schematic illustration of the packaging machine according to the invention.

FIG. 1 shows the packaging machine 1 according to the invention, which has a thermoforming station 2, a filling station 7, and also a sealing station 19. A material web 8, in this case a plastic film web 8, or what is known as the lower web, is drawn off from a supply roll and is transported along the packaging machine according to the invention from right to left, preferably cyclically. During one cycle, the material web 8 is transported over a pattern length. For this purpose, the packaging machine has two transport means, in the present case two endless chains, which are arranged to the right and left of the film web. Both at the start and at the end of the packaging machine, at least one gearwheel is provided for each chain, about which the respective chain is returned. At least one of these gearwheels is driven. The gearwheels in the entry region and/or in the exit region can be interconnected, preferably by means of a rigid shaft. Each transport means normally has a multiplicity of clamping means, which clamp the material web 3 in the intake region and transmit the movement of the transport means onto the lower film 8. In the discharge region of the packaging machine, the clamped connection between the transport means and the material web 8 is released again. In the thermoforming station 2, which has an upper tool 3 and a lower tool 4, which has the shape of the packaging well to be produced, the packaging wells 6 are formed in the film web 8. The lower tool 4 is arranged on a lift table 5, which, as indicated by a double-headed arrow, is vertically adjustable. The lower tool 4 is lowered before the film is advanced, and is then raised again. In the further course of the packaging machine, the packaging wells are then filled in the filling station 7 with the product to be packaged 16. In the adjoining sealing station 19, which likewise consists of an upper tool 12 and a vertically adjustable lower tool 11, an upper film 14 is integrally bonded to the material web 8, preferably by means of sealing. In the sealing station too, the upper tool and/or the lower tool are lowered and raised before and after each transport phase of the film respectively. Before the upper film 14 is sealed to the lower film 8, a certain negative pressure is generated in the filled packaging well and/or a gas exchange is carried out. The generation of the negative pressure and/or the gas exchange is preferably implemented whilst the respective packaging well is located within the sealing station, preferably immediately prior to the sealing tools 11, 12 being pressed against one another. The upper film 14 can be guided in transport means or transported by transport chains, wherein these transport means then extend only from the sealing station and downstream where necessary. Otherwise, the statements made regarding the transport means of the lower film are applicable. In the further course of the packaging machine, the finished packagings are separated, which occurs in the present case by means of the transverse cutter 25 and the longitudinal cutter 23. The transverse cutter 25 can likewise be lifted and lowered in the present case by means of a lifting device 9.

FIG. 2 shows the sealing station of the packaging machine according to the invention, in which an upper film web is sealed onto the filled packaging wells 6. The packaging wells not yet closed by a cover film are provided with the reference sign 6, and the packaging wells already closed are provided with the reference sign 6′. It can likewise be inferred from the illustration according to FIG. 2 that this packaging machine operates cyclically, wherein, during each cycle, a pattern 15, which in the present case consists of three rows and three columns of packaging wells, is transported further by a certain amount, in particular along the length of the pattern 15. The direction of transport is indicated by an arrow. Before the respective packaging well is closed by the cover film, air is sucked from the packaging wells in accordance with the invention. This is achieved in the present case by means of a degassing means 17, which is arranged transverse to the direction of transport of the film web, which is illustrated by the arrow. This degassing means 17 is designed in the present case such that a gassing means 13 is also provided in the same structural unit and blows an exchange gas into the packaging wells once the air is removed from the packaging wells or as the air is being removed from the packaging wells. In the present case, all packaging wells within a pattern are degassed and/or gassed simultaneously.

FIG. 3 basically shows the embodiment according to FIG. 2, wherein, in the present case, the degassing means 17 and/or the gassing means 13 is/are arranged parallel to the frame 10 of the packaging machine and/or parallel to the direction of movement of the film web 8 and are each provided as separate units. In particular in the present case, air can be removed from the packaging wells by means of the degassing means 17 and an exchange gas can then be fed to the packaging wells thereafter and/or simultaneously by means of the gassing nozzle 13.

As can be inferred in particular from FIG. 4, a gas-storage tank 18 and/or a vacuum-storage volume 20 is/are provided in the region of the packaging machine, in particular within the frame 10 of the packaging machine. These volumes are connected by means of a short path to the degassing and/or gassing nozzle 13, 17. A shut-off member, for example a valve, is provided at this juncture in each case. The vacuum-storage volume 20 is connected in the present case to a vacuum means, in this case a vacuum pump 21, which is operated such that approximately the required volume with regard to the required negative pressure and/or the required quantity is available before the actual degassing of the respective packaging well or pattern of packaging wells. For this purpose, a vacuum in the vacuum-storage volume 20 is drawn, in particular before air is sucked from the packaging wells. The gas-storage volume 20 preferably has a volume that is exactly the same as or greater than the volume that is required for the gas exchange of the respective pattern of packaging wells during one cycle. To this end, this storage volume 18 is filled for example from a gas source, in this case a gas supply tank 22, before the packaging wells are actually gassed.

FIG. 5 basically shows the embodiment in FIG. 4, wherein, in the present case, separate gassing and degassing nozzles 13, 17 are provided and are each connected separately to the respective storage volume 18, 20.

LIST OF REFERENCE SIGNS

• 1 packaging machine
• 2 thermoforming station
• 3 upper tool of the thermoforming station
• 4 lower tool of the thermoforming station
• 5 lift table, support of a tool of the sealing station, thermoforming station and/or of the cutting device
• 6, 6′ packaging well
• 7 filling station
• 8 lower material web, lower film web
• 9 lifting direction
• 10 frame
• 11 lower tool of the sealing station
• 12 upper tool of the sealing station
• 13 gassing means, gassing nozzle
• 14 upper material web, upper film web, cover film
• 15 pattern
• 16 product to be packaged
• 17 degassing means
• 18 gas-storage volume, gas-storage tank
• 19 sealing station
• 20 vacuum-storage volume, vacuum-storage tank
• 21 vacuum pump
• 22 gas source, gas supply tank
• 23 -
• 24 intake region
• 25 cutting device

Claims

1. A packaging machine, comprising: a thermoforming station, which forms packaging wells in a material web, anda sealing station, which integrally bonds an upper material web to the material web,wherein, prior to the integral bond being made, the packaging well is degassed and gassed, and a cutting device, which separates the packagings thus produced from the material webs,wherein the packaging machine operates cyclically,wherein the packaging machine has a gas-storage and/or vacuum-storage volume provided in the region of the packaging machine, in which at least the vacuum volume required for one cycle is provided.

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. The packaging machine as claimed in claim 1, wherein the packaging machine has a gassing means and/or a degassing means.

11. The packaging machine as claimed in claim 10, wherein the gassing means and the degassing means are provided in one unit.

12. The packaging machine as claimed in claim 1, wherein the packaging machine has a controller, which controls the fed gas and/or the vacuum.

13. The packaging machine as claimed in claim 10, wherein the packaging machine has a controller, which controls the fed gas and/or the vacuum.

14. The packaging machine as claimed in claim 11, wherein the packaging machine has a controller, which controls the fed gas and/or the vacuum.

15. A method for producing a packaging, in which a material web is transported cyclically along a packaging machine and, during each cycle, one or more packaging wells is/are formed in the material web and the packaging well is then filled with a product to be packaged, and a cover film is then sealed onto the packaging well, wherein, prior to the sealing operation, a vacuum is drawn and/or a gas exchange is carried out in the packaging well,wherein at least the majority of the vacuum volume required for one cycle is provided in the region of the packaging machine during the sealing and/or during the transport of the material web.

16. The method as claimed in claim 15, wherein the vacuum required for one cycle is established, at least substantially, before the packaging well is degassed.

17. The method as claimed in claim 15, wherein the quantity of gas and/or the negative pressure is/are controlled.

18. The method as claimed in claim 18, wherein the quantity of gas and/or the negative pressure is/are controlled.

19. The method as claimed in claim 17, wherein they are controlled in accordance with the filling capacity of the packaging well.

20. The method as claimed in claim 18, wherein they are controlled in accordance with the filling capacity of the packaging well.