Sealing station for sealing a package

Abstract

Sealing station (100) for sealing a package, the sealing station (100) comprising a receptacle (111) for a packaging recess (130) and product (131) placed therein, a sealing tool (225) for sealing the packaging recess with a sealing film (232) and a vacuum unit (213) for pressurizing the interior of the packaging recess (130) before sealing, characterized in that the sealing station (100) comprises a lifting element (240) for raising the packaging recess (130) depending on a product height (h) of the product (131) placed therein in the direction of the sealing tool (225).

Description

The present invention relates to a sealing station for sealing a package according to claim 1 and to a method for sealing a package with a sealing station according to claim 8.Prior ArtSealing stations are known from the prior art. These usually comprise a lower tool and an upper tool, which can be moved relative to one another. In the lower tool, a packaging trough with product introduced therein can be arranged in a receptacle. Subsequently, in the sealing station, the sealing film can be applied to the packaging cavity and the interior of the sealing film can be evacuated. The sealing film is then connected to the packaging cavity, for example by heat input, in order to seal the packaging cavity.During evacuation of the interior of the packaging tray, a strong vacuum is applied. In brittle products such as large cheese-rolls, the pressure differential between the interior of the product and the interior of the evacuated packaging cavity can adversely affect the product such as, for example, cheese-rolls. This leads to breakage of the cheese slab. This can lead to a reduced product quality.The object is to provide a method for performing a processStarting from the known prior art, the technical problem to be solved is thus to obtain the product quality as far as possible during the evacuation of the packaging cavity and during the sealing.SolutionThis object is achieved according to the invention by the sealing station for sealing a package according to independent claim 1 and the method for sealing a package with a sealing station according to independent claim 8. Advantageous refinements of the invention are covered in the dependent claims.The sealing station according to the invention for sealing a packaging comprises a receptacle for a packaging cavity and product introduced therein, a sealing tool for sealing the packaging cavity with a sealing film and a vacuum unit for applying pressure to the interior of the packaging cavity before sealing, characterized in that the sealing station comprises a lifting element for lifting the packaging cavity depending on a product height of the introduced product in the direction of the sealing tool.If the product already abuts the sealing film, the lifting of the packaging trough can also merely comprise bringing about an increased pressure in the direction of the product by the lifting element, such that the pressure acting on the product between the sealing tool and the lifting element reaches or exceeds a minimum value or limit value. In any case, it is provided that the packaging trough with the product introduced therein is raised relative to the receptacle and / or an additional pressure can be exerted on the product by the lifting element.By raising the packaging cavity, the product can be pressed against the sealing tool and thus against the sealing film even in the event of a variability in the product height. This results in the product being supported during the evacuation, so that the dimensional stability of the product can be better ensured.With the sealing station according to the invention, a high product quality can also be ensured at a constant high throughput.In one embodiment, the lifting element comprises a contact surface which can be in contact with a support surface of the packaging tray during lifting, and wherein the shape and / or size of the contact surface substantially corresponds to the support surface.The bearing surface of the packaging trough is the surface of the packaging trough with which it at least partially rests on the contact surface of the lifting element. The fact that the contact surface substantially corresponds to the support surface can comprise the contact surface being of the same size (in terms of shape and / or size) as the support surface of the packaging cavity. It can also be provided that the contact surface has, for example, an area that is larger by up to 5% or up to 10% or has an area that is smaller by a percentage, for example up to 5% or up to 10%, than the contact surface. In particular, it can be provided that, independently of the size of the contact surface relative to the support surface, the shape of the contact surface is geometrically similar to the shape of the support surface of the packaging cavity. As a result, the packaging tray can be reliably raised.It can be provided that a lifting force of the lifting element can be controlled depending on the product height and / or a counter pressure acting on the product. By adjusting the lifting force, on the one hand, the movement of the lifting element in the direction of the packaging trough or in the direction of the sealing tool can be controlled and, on the other hand, for example, a pressure acting on the product can also be adjusted to a desired value. Controlling the lifting force as a function of the product height allows sealing of products of different heights without or with reduced risk of damage.The lifting element can comprise at least two compensating elements for compensating a lifting movement depending on the product shape.With this embodiment, in particular in the case of a variable shape of the product, for example as viewed in the direction of the lifting element or in the direction of the sealing tool (here in particular non-planar surfaces of the product), compensation can take place, so that the pressure acting on the product between lifting element and sealing tool assumes a substantially equal value as far as possible over the entire surface of the product.It can be provided that the at least two compensating elements comprise a passive compensating element and / or an active compensating element.A passive compensating element is to be understood as a compensating element which sets an amplitude of the lifting movement, which is experienced by at least a part, for example, of a support of the lifting element on which the product rests, by a force, in particular a pressure, exerted on the passive compensating element, and a counterforce exerted thereon by the passive compensating element. A passive compensating element can be a spring or comprise a spring, for example. In this sense, the passive compensating element does not have a drive element assigned to it, with which a lifting movement could be actively brought about. An active compensating element is a compensating element which has a suitable drive element or is assigned to it such a drive element in order to bring about a lifting movement of at least one part, for example a bearing of the lifting element on which the product rests. The active balancing element may comprise, for example, a pneumatic element, such as a pneumatic cylinder. These compensating elements can achieve a reliable compensation of height differences or non-plane-parallel surfaces of the product.It can be provided that the lifting element comprises at least three compensating elements and the compensating elements are arranged at equal angular distances and / or equidistantly along a circumferential direction.The circumferential direction is basically to be understood as the outer edge of the lifting element, in particular a contact surface or support of the lifting element for making contact with the packaging trough. It does not therefore have to be a circle, but rather it can also define any other desired geometric shape, such as a rectangle or an ellipse or the outer boundary thereof. The three compensating elements can ensure that the product experiences the same movement and / or the same pressure substantially along its entire surface.In one embodiment, the lifting element comprises a pneumatic element, such as a pneumatic cylinder, for causing a lifting force and a proportional valve for pressurizing the pneumatic element depending on the lifting force to be caused. This embodiment can be controlled particularly easily as a function of pressure, so that the movement of the lifting element or the driving force acting on the lifting element can be reliably adjusted in the form of a control loop.According to the invention, a method for sealing a package with a sealing station is provided, the sealing station comprising a receptacle for a packaging cavity and product introduced therein, a sealing tool for sealing the packaging cavity with a sealing film and a vacuum unit for applying a negative pressure to the interior of the packaging cavity before the sealing, characterized in that the sealing station comprises a lifting element for lifting the packaging cavity depending on a product height of the introduced product in the direction of the sealing tool, wherein the method comprises lifting the packaging cavity at least during a period during which a negative pressure is applied to the interior of the packaging cavity, and subsequently sealing the packaging cavity.With this method, a constant product quality during sealing can be ensured.It can be provided that the lifting element comprises a contact surface which is in contact with a support surface of the packaging trough during lifting, and wherein the shape and / or size of the contact surface substantially corresponds to the support surface. A reliable supporting of the product and lifting of the product or of the packaging tray over its entire surface is thus ensured.In one embodiment, it is provided that a lifting force of the lifting element is controlled as a function of the product height and / or a counterpressure acting on the product. This embodiment prevents damage to the product during lifting.The lifting element may comprise at least two compensating elements for compensating a lifting movement depending on the product shape, wherein during the lifting of the package the lifting movement is compensated such that an upper surface of the product lies substantially at a predetermined height level. As a result, a pressure or lifting movement which is as constant as possible can be realized over the entire surface of the packaging trough or of the product.It can be provided that the at least two compensating elements comprise a passive compensating element and / or an active compensating element. The accuracy with which the compensation of different product shapes can be effected is hereby increased.In one embodiment, the lifting element comprises at least three compensating elements and the compensating elements are arranged at equal angular distances and / or equidistantly along a circumferential direction. This achieves a pressure that is as constant as possible over the entire surface of the packaging trough or of the product.The lifting element may comprise a pneumatic element, such as a pneumatic cylinder, for effecting a lifting force and a proportional valve for pressurizing the pneumatic element depending on the lifting force to be effected. This configuration can be easily controlled.All of the embodiments described herein may be combined with each other.Brief Description of the FiguresFIG. 1 shows a sealing station according to an embodiment. FIG. 2 shows a receptacle with a packaging trough introduced therein in relation to the sealing tool according to one embodiment. FIG. 3 shows a lifting element with compensating elements according to one embodiment. FIGS. 4 and 5 show different embodiments of compensating elements.DETAILED DESCRIPTIONFIG. 1 shows a schematic view of a sealing station 100 according to an embodiment. The sealing station 100 comprises a lower tool 101 and an upper tool 102, which can be moved towards one another in accordance with the double arrow direction shown. It is not absolutely necessary for the entire upper tool 102 and / or the entire lower tool 101 to be moved. For sealing, it is sufficient that components of the lower tool or of the upper tool are moved.In the lower tool 101 a receptacle 111 is arranged for receiving a packaging trough 130 with filled product 131. If the packaging cavity 130 with the introduced product 131 is arranged in the receptacle 111, the sealing of the packaging cavity with a sealing film can take place, as is described in connection with FIG. 2.The sealing station 100 can be assigned a control unit 180, which can be designed, for example, as a central control unit of the sealing station and can comprise, for example, a computer with a suitable processor or processors and assigned memory.The sealing station 100 can be assigned a transport device or a feed conveyor 151, which is designed, for example, as a transport belt. Along a transport direction T, packaging troughs 130 with product 131 introduced therein can be transported in this transport device 151 and fed to the sealing station. The introduced product 131 can be in particular food and here in particular whole cheese milk or the like.The packaging troughs 130 are dimensioned accordingly. The packaging tray may be a packaging tray produced in a thermoform packaging machine and / or may have a shape substantially corresponding to that of the product 131. If the product is, for example, a cheese level with a substantially cylindrical shape, the packaging trough can likewise be of substantially cylindrical configuration. However, this is not obligatory and the packaging trough can also be designed, for example, as a cuboid into which the cheese milk is introduced. The invention is not limited in this respect.Furthermore, the sealing station 100 can be assigned an output conveyor 152 which can discharge sealed packages 132 from the sealing station 100. The discharge conveyor can likewise be designed as a transport belt.FIG. 2 shows a sectional view through the receptacle 111 of FIG. 1, according to one embodiment. In the embodiment shown here, a packaging trough 130, which is to be sealed with a sealing film 232, is arranged in the receptacle 111. A product 131 is arranged in the packaging trough 130. This product has a height h which extends from the lower tool 101 in the direction of the upper tool 102.It is provided that the sealing station 100 comprises a vacuum unit 213, which can be arranged, for example, in the lower tool 101 and can be connected to the interior of the packaging cavity 130 via a suitable line 214, wherein preferably the vacuum line 214 can project into the interior of the packaging cavity 130 between the packaging cavity 130 and the sealing film 232 at least partially resting on the packaging cavity 130 or can be connected to the latter for the purpose of evacuating the interior of the packaging cavity 130.In order to delimit the region in which the packaging cavity 130 or its interior is evacuated from the environment, one or more sealing elements 222 in the upper tool 102 and corresponding one or more sealing elements 212 in the lower tool 101 can be provided, which can be brought into contact with one another in order to separate a region in which the receptacle 111 and the sealing tool 225 seal the packaging cavity with the sealing film 232 from the environment in a gas-tight manner as possible. It can be provided that the sealing film 232 is clamped between the sealing elements 222 and 212 at least during the evacuation and / or during the sealing. This reduces, on the one hand, the space to be evacuated (to the space enclosed by the receptacle 111 and the packaging trough 130 and the sealing film 232) and, on the other hand, prevents the sealing film 232 from being positioned incorrectly in an undesirable manner.The upper tool 102 preferably comprises a sealing tool 225 or can constitute this. The sealing tool 225 comprises at least one sealing element 232 which can be brought into contact with the sealing film 232 in a region in which the sealing film also rests at least partially on the packaging trough 130. The sealing element 232 can then bring about a connection of the packaging cavity 130 to the sealing film 232, for example by the introduction of heat.It can be provided in particular that the sealing by the sealing element 223 takes place after the interior of the packaging cavity 130 has been evacuated. This can ensure that no air remains in the interior of the packaging cavity, so that the product quality can also remain ensured over a longer time.The sealing tool 225 may comprise a counter-pressure element 224 which, together with the sealing element 223, can be moved in the direction of the receptacle 111 for sealing purposes and / or the receptacle 111 with the packaging trough 130 arranged therein can be moved towards the latter.If the height h of the product 131 in the packaging cavity 130 corresponds to a distance between the lower surface of the receptacle 111 (the surface on which the packaging cavity rests) and the surface of the counterpressure element 224 in the sealing position pointing in the direction of the receptacle 111, the product 131 is clamped and / or fixed between the receptacle 111 and the counterpressure element 224 and damage to the product does not occur or these are less likely even when the interior space of the packaging cavity 130 is evacuated.However, due to variations in the shape and / or size of products 131, it may occur that the product has a height lower than the required height h, which is why the product is not contacted by the surface of the receptacle and the surface of the counter-pressure element 224 in the sealing position. As a result, the product is not fixed and undesired adverse effects on the product quality can occur on account of the pressure gradient which occurs during the evacuation of the packaging cavity.According to the invention, it is therefore provided that the sealing station 100 further comprises a lifting element 240 which is arranged and configured to lift the packaging trough 130 with the product 131 introduced therein in the direction of the sealing tool 225 and here for example in the direction of the counterpressure element 224, such that any height difference between a setpoint height h of the product 131 and its actual height can be compensated and / or the product can be fixed and / or clamped between the sealing tool and the receptacle or the lifting element.For this purpose, the lifting element 240 can comprise a movably arranged support 241 having a contact surface 245 which can come into contact with the packaging trough 130. Furthermore, a drive element 242 can be assigned to the lifting element, which can be designed, for example, as a pneumatic element, in particular as a pneumatic cylinder. The pneumatic element can be connected, for example, to a compressed air supply 244 which can supply compressed air to the pneumatic cylinder via a controllable proportional valve 243. This embodiment is, however, to be understood as merely exemplary. The drive element of the lifting element 240 can also be designed, for example, as an actuating drive or as a servomotor.In particular, it can be provided that the lifting element 240 and here in particular the drive element 242 is connected to the control unit 180 in such a way that the lifting of the packaging trough 130 by the lifting element 240 can be controlled as a function of a product height and / or a pressure acting on the product, in particular a counterpressure by the counterpressure surface 224, in such a way that the product is preferably held securely between the sealing tool 245 and the receptacle 111 during the evacuation.For this purpose, a sensor 281 may be arranged in the sealing station 100, which may measure the product height and / or a pressure acting on the lifting element 240 and / or the counter-pressure element 224. Depending on the measured product height h and / or the pressure exerted by the product on the lifting element 240 and / or the counter-pressure element 224 or the sealing tool 225, the drive element 242 of the lifting element can then be controlled by the control unit 180 in such a way that either the height difference of the product (deviation of the height h from a desired height) is compensated by lifting the product and / or the product is lifted to such an extent that a required pressure exerted by the product on the lifting element and / or the counter-pressure element 224 or the sealing tool 245 is achieved.This ensures that the product, such as a cheese level, is not damaged even when a strong vacuum is applied and thus a large pressure difference is applied between the interior of the packaging cavity and the interior of the product itself. In this connection, the clamping of the product between the sealing tool 245 and the receptacle 111 or lifting element 240 has a stabilizing effect on the product 131, so that, if possible, air can escape from the product without any breakage or damage occurring within the product and thus a reduced quality of the product.It can be provided that the lifting element lifts the product already before the evacuation of the interior of the packaging cavity 130 is effected by the vacuum unit. The lifting of the product can then take place until at least the evacuation of the interior space is concluded and / or until the sealing of the packaging cavity with the sealing film 232 which follows the evacuation of the interior space of the packaging cavity is concluded. Alternatively or additionally, the lifting of the product can also be carried out until a ventilation process of the interior of the sealing station has been carried out at least partially or completely after the evacuation. Alternatively, it can also be provided that the evacuation of the packaging trough initially begins without the packaging trough 130 already being lifted by the lifting element 240. The raising or increasing of the pressure acting on the product 131 can then take place successively during the evacuation.It can be provided that the distance between the product and the sealing tool and / or the pressure exerted by the product on the lifting element and / or the sealing tool is measured continuously (for example at a distance of a few milliseconds) with the sensor 281 and is controlled in dependence thereon by the control unit of the lifting element 240 in order to lift the packaging trough 130 with the product 131 arranged therein. This can be advantageous in order to take into account air escaping from the product, for example during the evacuation, and to continue to ensure product stability.In the cross-sectional view shown here, the lifting element and in particular the support 241 extends only over part of the extent of the packaging trough 131. This is to be understood as merely exemplary. It can be provided in particular that the shape and / or size of the contact surface 245 corresponds to the shape and / or size of the packaging trough 130 or is identical thereto. It is particularly preferred if the contact surface 245 is geometrically similar to the support surface of the packaging trough 130, wherein it can be larger or smaller than the support surface of the packaging trough 130. Embodiments are particularly preferred in which the support surface 245 has at least the same shape and size as the product 131, so that a reliable movement of the entire product can be ensured. It can be provided that the contact surface 245 has the same shape as the packaging cavity 130, but is larger than the packaging cavity 130, in particular has a larger surface area (for example up to % or up to 10% larger surface area. In this way, minor malpositions of the packaging trough 130 in the receptacle 111 can be compensated for and a complete lifting of the packaging trough can nevertheless be achieved.Furthermore, it can also be provided that the support surface or the support 241 can be the entire lower surface of the receptacle 111, so that the receptacle 111 is delimited by immovable side surfaces and the support 241, which is movable with respect to these side surfaces.FIG. 3 shows a further embodiment of a lifting element 240. In this embodiment, the lifting element 240 comprises, in addition to a possibly provided drive element 242 (see FIG. 2 ), at least two compensating elements 351, 352 and 353 which are connected to the support 241.In the embodiment shown here, the drive element 242 is connected to the support 241 at the center M of the support. The support 241 is shown here as substantially circular, so that the center point coincides with the center of gravity of the support 241. Alternatively (for example if the support 241 is configured with a different shape), it can be provided that the drive element is connected to the support at the center of gravity of the support, wherein the center of gravity does not have to coincide with the geometric center. As a result, the torques acting on the support are kept as low as possible during the lifting by means of the drive element 242.In addition, in this embodiment, compensating elements 351, 352 and 353 are provided, which in the embodiment shown here are arranged, measured at the same angular distance α to one another, in each case to the center M and at a distance to the center M. The compensating elements can be provided in order to compensate for an active or passive compensation of the lifting movement of the product depending on the product shape, in particular with regard to deviations of the product shape in a direction parallel to movement directions of the lifting element 240.While the compensating elements are arranged here at an identical angular distance α from one another, it can alternatively or additionally also be provided that they are arranged equidistantly from one another, for example along an imaginary circumferential direction r of the support 241. The circumferential direction r may be defined by the outer shape of the support 241 and need not represent a circle. If the support 241 is designed, for example, as a rectangle, it can be provided, for example, that the circumferential direction follows the outer boundary edge of this rectangle or is parallel thereto. The distance of the compensating elements 351 to 353 from one another can then be measured, for example, along a direction which runs parallel to this outer boundary edge, and can be the same for all compensating elements 351 to 353.It is understood that the number of balancing elements is not limited. Thus, in one embodiment, it can be provided that only two compensating elements are provided, which can be arranged approximately on opposite sides of the drive element 242, such that the points at which the compensating elements are connected to the support 241 and the point at which the drive element 242 is connected to the support 241 lie on a common straight line. Three compensating elements (as shown here) can also be provided. It is also possible for more than three compensating elements, for example four, five or six compensating elements, to be provided, which can then be arranged equidistantly with respect to one another and / or at the same angular distance as described above.FIG. 3 likewise shows the basic function of the compensating elements using the example of the compensating elements 351 and 352. In the embodiment shown here, a base surface of the product 131 is not parallel to a top surface of the product 131, such that a height difference Δh is established between two points along the surface of the product 131, which is schematically illustrated here. If the support 241 is moved by the drive element 242 along the arrow direction shown and the product comes into contact with the counterpressure element of the sealing tool (see FIG. 2 ), this leads either to squeezing of the product 131 on the higher side or to incomplete pressing of the product against the counterpressure element of the sealing tool on the side lower by Δh.In order to compensate for this, the support 241 can be rotatably connected to the drive element 242, for example via a ball bearing 355. Thus, the support can be pivoted with respect to the drive element 242 along the illustrated curved double arrow direction. The angle of the support 241 (for example measured relative to a desired height level 360) can be actively or passively influenced here by the compensating elements 351 and 352 on which the support 241 likewise rests in such a way that the height difference Δh is compensated by tilting the support 241 and the contact surface of the product 131 corresponds to the predefined orientation 360 or a predefined height level by raising one side of the support 241 and / or lowering another side of the support 241.The compensating elements of FIG. 3 can either be fixedly connected to the support 241 (here, for example, likewise via ball bearings or similar rotatable connections). Or the compensating elements 351 to 353 cannot be firmly connected to the support 241, but the support can rest on these compensating elements and otherwise be configured to be freely movable with respect to the compensating elements 351 to 353. Since, when the support 241 is raised, the support 241 aligns itself relative to the drive element 242 via the ball bearing in such a way that the surface of the product becomes equal to the desired height level 360, the support 241 rotates as a result, so that it comes into contact with the compensating elements 351 to 353. The compensating elements can then control a further rotation of the support (for example by building up a counter pressure by one or more compensating elements).FIGS. 4 and 5 show various embodiments of a compensating element 351.In FIG. 4, the compensating element 351 is designed as a passive compensating element. It may comprise a frame 452, opposite which a connecting element 453, which is either fixedly connected to the support 241 or may be in contact therewith, may be moved. A spring member 454 is disposed in the frame 452 so as to be configured to cause a spring force toward the connecting member 453.The spring force can be set such that the receptacle 241 is lowered in the event of too great a pressure acting on the product (i.e. the spring is compressed). If the pressure acting on the product is too low, the spring element 454 can cause the receptacle 241 to be raised via the connecting element 453. For this purpose, the passive compensating elements 351 are preferably moved with the receptacle at least partially, or are raised with the latter via the drive element 242, so that the spring element 454 is not stretched too far or is moved out of an initial position.Instead of a spring or a spring element, the passive compensating element 351 can also comprise a pneumatically actuatable element 454. A pressure may be applied within the frame 452 corresponding to the desired pressure acting on the product. If the pressure actually acting on the product is too low, this can be transferred into a movement of the support 241. If the pressure is too high, the gas volume in the interior of the frame 452 is further compressed by deeper penetration of the connecting element 453, and the pressure increases so that a reduction in the pressure acting on the product can be achieved.Alternatively, it may also be provided that the compensating element comprises a pair of repulsive magnets, wherein one of the magnets is firmly connected to the frame 452 and the other magnet is connected to the connecting element 453. If the pressure acting on the product increases through the counterpressure element or sealing tool, the connecting element 453 can be moved in the direction of the frame 452, so that the support is lowered. This takes place against the magnetic force caused by the repulsive magnets, so that the pressure acting on the product can be adjusted depending on the magnetic force acting.FIG. 5 shows an alternative embodiment of a compensating element 351 to that of FIG. 4. In this embodiment, a drive element 455 (for example an actuating drive) is arranged in the frame 452, which is operatively connected to the connecting element 453, such that a movement of the connecting element 453 is effected and the receptacle 241 can be raised or lowered. This embodiment represents an active compensating element.The drive element 455 can be connected, for example, to the control unit (see FIG. 1 ) and the control unit can control the drive element 455 in such a way that the movement of the connecting element 453 and the movement of the support 241 effected therewith can bring about a change in the position of the support 241 or of the product and / or a change in the pressure acting on the product. The drive element 455 can be controlled or regulated (for example in combination with a measurement of the pressure acting on the product with the sensor 281, as described in FIG. 2 ) such that the pressure acting on the product always corresponds to a desired value.

Claims

Sealing station (100) for sealing a package, the sealing station (100) comprising a receptacle (111) for a packaging trough (130) and product (131) introduced therein, a sealing tool (225) for sealing the packaging trough with a sealing film (232), and a vacuum unit (213) for acting on the interior space of the packaging trough (130) before sealing, characterized in that the sealing station (100) comprises a lifting element (240) for lifting the packaging trough (130) depending on a product height (h) of the introduced product (131) in the direction of the sealing tool (225).The sealing station (100) according to claim 1, wherein the lifting element (240) comprises a contact surface (241) that can be in contact with a support surface of the packaging tray (130) during lifting, and wherein the shape and / or size of the contact surface (241) substantially corresponds to the support surface.Sealing station (100) according to claim 1 or 2, wherein a lifting force of the lifting element (240) can be controlled depending on the product height (h) and / or a counter pressure acting on the product (131).Sealing station (100) according to any of claims 1 to 3, wherein the lifting element (240) comprises at least two compensating elements (351, 352, 353) for compensating a lifting movement depending on the product shape.Sealing station (100) according to claim 4, wherein the at least two balancing elements (351, 352, 353) comprise a passive balancing element and / or an active balancing element.Sealing station (100) according to one of claims 4 or 5, wherein the lifting element (240) comprises at least three compensating elements (351, 352, 353) and the compensating elements are arranged at equal angular distances and / or equidistantly along a circumferential direction.Sealing station (100) according to any of claims 1 to 6, wherein the lifting element (240) comprises a pneumatic element (242), such as a pneumatic cylinder, for causing a lifting force and a proportional valve (243) for applying pressure to the pneumatic element (242) depending on the lifting force to be caused.Method for sealing a package with a sealing station (100), the sealing station (100) comprising a receptacle (111) for a packaging trough (130) and product (131) introduced therein, a sealing tool (225) for sealing the packaging trough (130) with a sealing film and a vacuum unit (213) for applying a negative pressure to the interior of the packaging trough before sealing, characterized in that the sealing station (100) comprises a lifting element (240) for lifting the packaging trough (130) depending on a product height (h) of the introduced product (130) in the direction of the sealing tool (225), wherein the method comprises lifting the packaging trough (130) at least during a period during which the vacuum unit (213) is applied with a negative pressure to the interior of the packaging trough (130), and subsequently sealing the packaging trough (130).The method of claim 8, wherein the lifting element (240) comprises a contact surface (241) that is in contact with a support surface of the packaging tray (130) during lifting, and wherein the shape and / or size of the contact surface (241) substantially corresponds to the support surface.Method according to claim 8 or 9, wherein a lifting force of the lifting element (240) is controlled depending on the product height (h) and / or a counter pressure acting on the product (131).Method according to any of claims 8 to 10, wherein the lifting element (240) comprises at least two compensating elements (351, 352, 353) for compensating a lifting movement depending on the product shape, wherein during the lifting of the packaging trough the lifting movement is compensated such that an upper surface of the product (131) lies substantially at a predetermined height level (360).The method of claim 11, wherein the at least two balancing elements (351, 352, 353) comprise a passive balancing element and / or an active balancing element.Method according to claim 11 or 12, wherein the lifting element (240) comprises at least three compensating elements (351, 352, 353) and the compensating elements (351, 352, 353) are arranged at equal angular distances and / or equidistantly along a circumferential direction.Method according to any of claims 8 to 13, wherein the lifting element (240) comprises a pneumatic element (242), such as a pneumatic cylinder, for causing a lifting force and a proportional valve (243) for pressurizing the pneumatic element depending on the lifting force to be caused.

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