Thermoforming packaging machine for shaping packaging material

Abstract

Thermoforming packaging machine (100) for forming packaging material (130), the thermoforming packaging machine comprising a receptacle (111) for receiving packaging material, a punch (121) movable in the receptacle in the direction of the packaging material to be formed, and a drive (241) for driving the punch (121), wherein the drive (241) is configured to superimpose a vibrational movement (250) of the punch in the direction of the movement (240) and against the direction of the movement (240) on a movement (240) of the punch during contact between the punch and the packaging material (130), wherein the vibrational movement has an amplitude (h) that is smaller than the distance (H) traveled by the punch (121) during the movement (240), and wherein the vibrational movement has a frequency (f) that is greater than the inverse of the duration (T) of the movement (240).

Description

[0001] The present invention relates to a thermoforming packaging machine for shaping packaging material according to independent claim 1 and to a method for shaping packaging material with a thermoforming packaging machine according to independent claim 9. State of the art

[0002] Thermoforming packaging machines for shaping packaging material are well known in the art. These typically include fixtures into which the packaging material to be shaped or thermoformed can be inserted, for example, as a film web or as individual pieces of packaging material. Subsequently, a punch is moved towards the packaging material to be shaped, pressing it into the fixture along with the punch, thus forming the packaging material into the package.

[0003] To ensure reliable deformation, it is known to heat the packaging material using a preheating station and then deform it using the stamp.

[0004] During subsequent forming with a die, uneven distribution of packaging material or damage to the packaging material can occur. This negatively impacts the quality of the thermoformed packaging, both in terms of appearance and the final forming result. Furthermore, it is difficult to achieve consistent wall thicknesses, especially with thin films.

[0005] From DE 10 2016 106 142 A1, packaging materials and methods for producing a three-dimensionally shaped packaging material by compression drawing from a flat, plastically deformable packaging material web (1) comprising at least one fibrous material are known, wherein a blank for the packaging material is connected to the packaging material web via at least one web during compression drawing and is otherwise separated from the packaging material web by at least one relief cut. The web is designed such that it remains in place until the packaging is completed, so that a composite in the form of a multi-pack is obtainable. The known forming, filling, and sealing machine has a cutting device which is designed and arranged such that it partially separates webs between the packaging material web and the packaging material in such a way that a composite in the form of a multi-pack is cut out of the packaging material web.

[0006] DE 10 2006 043 643 B3 shows a deep drawing device for metal parts with a deep drawing die and a hold-down device, each of which can be subjected to an oscillating force. Task

[0007] Based on the known state of the art, the technical problem to be solved is therefore to specify a thermoforming packaging machine and a method for forming packaging material, with which reliable forming of the packaging material is achieved while maintaining high quality of the packaging produced. Solution

[0008] This problem is solved according to the invention by the thermoforming packaging machine for shaping packaging material according to independent claim 1 and the method for shaping packaging material with a thermoforming packaging machine according to independent claim 8. Advantageous embodiments of the invention are covered in the dependent claims.

[0009] The thermoforming packaging machine according to the invention for deforming packaging material comprises a receptacle for receiving packaging material, a punch movable in the receptacle in the direction of the packaging material to be deformed, and a drive for driving the punch, wherein the drive is configured to superimpose a oscillating movement of the punch in the direction of the movement and against the direction of the movement on a movement of the punch during contact between the punch and the packaging material to be deformed, wherein the oscillating movement has an amplitude that is smaller than the distance traveled by the punch during the movement, and wherein the oscillating movement has a frequency that is greater than the inverse of the duration of the movement.

[0010] The movement of the stamp is preferably a one-dimensional movement, which can, for example, occur vertically or perpendicular to a base surface of the receptacle. The movement originates from above the packaging material to be deformed and proceeds towards the receptacle, so that the stamp presses the packaging material into the receptacle.

[0011] The movement, relative to which the frequency and amplitude of the oscillation are determined, is the section of the total movement of the punch during which the punch is in contact with the packaging material to be deformed.

[0012] By superimposing the movement of the punch with the vibration movement, at least a temporary detachment of the punch from the packaging material or a temporary reduction of the force exerted by the punch on the packaging material, in particular a frictional force between punch and packaging material, can be achieved, so that the packaging material can stretch more evenly during the vibration movement, leading to an advantageously more uniform distribution of the packaging material during deformation.

[0013] The packaging material can be, in particular, a plastic film or comprise one. It can also be provided that the packaging material is fed into a receiving tray as individual packaging material components.

[0014] The drive may include a first drive element, such as a first servo motor, an electric motor or a pneumatic cylinder, to effect the movement and a vibration generator to effect the vibrational movement.

[0015] The vibration generator can be, for example, an ultrasonic element, a piezoelectric element, or an electric motor equipped with an imbalance (vibrational motor) that can superimpose a higher-frequency vibration onto the actual movement of the punch. A servo motor or actuator can also be used. Using two separate elements to drive the punch allows for the decoupling of the control for the actual punch movement and the control for the vibration, thus simplifying the control of these separate movements.

[0016] The drive system can be designed to comprise exactly one drive element, such as a servo motor, an electric motor, or a pneumatic cylinder, which can effect both the movement and the vibration. This embodiment makes the thermoforming packaging machine more compact.

[0017] In one embodiment, the frequency is an integer multiple of the inverse of the duration of the movement. This design ensures that, for example, when the end of the path to be traveled during the deformation of the packaging material is reached, the punch is in its lowest position and the end of the deformation process is not adversely affected by a counter-movement of the punch due to the oscillating motion.

[0018] In one embodiment, the amplitude is less than 10%, less than 1%, or less than 0.1% of the stroke. These amplitudes ensure that the plunger reliably releases from the packaging material being deformed, allowing the material to follow the deformation process and achieve the most uniform material thickness possible. It is understood that the amplitude of the oscillating motion cannot be arbitrarily small. In particular, the amplitude in every embodiment is greater than 0% of the stroke, and preferably greater than 0.005% of the stroke.

[0019] The frequency can be lower than the inverse of the relaxation time of the packaging material. The relaxation time of the packaging material, in this context, refers to the time the packaging material to be deformed requires after the punch is released during the oscillating motion to achieve, or at least partially achieve, a uniform distribution of material in the area in contact with the punch. This time depends, among other things, on the overall material thickness, the material from which the packaging material to be deformed is made, and the temperature prevailing during the deformation process, at least within the packaging material being deformed.This embodiment ensures that, firstly, the packaging material to be deformed is deformed during the vibration movement as long as the stamp is in contact with the packaging material to be deformed, and secondly, that the packaging material to be deformed has enough time during the entire deformation process to follow this deformation as evenly as possible, which improves the quality of the manufactured packaging.

[0020] The thermoforming packaging machine may include a control unit, a heating element for heating the die during movement, and a temperature sensor configured to measure the temperature of the packaging material being formed during movement. The control unit is configured to control the frequency and / or amplitude of the oscillating motion depending on the measured temperature of the packaging material. For example, if the temperature of the packaging material is close to a certain threshold, the amplitude of the movement or the frequency can be increased to cause the die to detach from the packaging material more frequently. This reduces heat input and can prevent damage or tearing of the packaging material. If the measured temperature of the packaging material is, for example,Below a predetermined minimum temperature, the amplitude or frequency can be reduced, so that the stamp makes more frequent contact with the packaging material to be deformed, or this contact is maintained for a longer period. This can increase the temperature of the packaging material, which can favorably influence the deformation process.

[0021] In one embodiment, the control unit is configured to control the frequency and / or amplitude of the oscillation based on the measured temperature of the packaging material to be deformed, such that the temperature of the packaging material remains below a first limit and / or above a second limit during the movement. The first limit can, for example, specify a maximum temperature of the packaging material, while the second limit can, for example, represent the minimum temperature required for deformation. The temperature of the packaging material can thus be kept within a preferred temperature range for deformation, which, on the one hand, allows for reliable deformation of the packaging material and, on the other hand, prevents damage or tearing, especially in the case of thin packaging materials.

[0022] According to the invention, a method for deforming packaging material with a thermoforming packaging machine is provided, the thermoforming packaging machine comprising a receptacle for receiving packaging material, a punch movable in the receptacle in the direction of the packaging material to be deformed, and a drive for driving the punch, wherein the drive is configured to superimpose a vibrational movement of the punch in the direction of the movement and against the direction of the movement on a movement of the punch during contact between the punch and the packaging material to be deformed, wherein the vibrational movement has an amplitude that is smaller than the distance traveled by the punch during the movement, and wherein the vibrational movement has a frequency that is greater than the inverse of the duration of the movement, wherein the method comprises: - moving the stamp together with the packaging material during the deformation of the packaging material and - Superimposition of the motion with the oscillatory motion.

[0023] This process allows even very thin packaging material to be reliably deformed, thus saving material for packaging and making its production more environmentally friendly.

[0024] The drive system can be configured to include a first drive element, such as a first servo motor, an electric motor, or a pneumatic cylinder, which effects the motion, and a vibration generator, which effects the vibration. Alternatively, the drive system can be configured to include exactly one drive element, such as a servo motor, an electric motor, or a pneumatic cylinder, which effects both the motion and the vibration. This ensures reliable initiation of both the motion and the vibration superimposed on the motion.

[0025] The frequency can be an integer multiple of the inverse of the duration of the movement. This embodiment ensures that, particularly when the end of the movement is reached, the stamp is located at one of the reversal points of the oscillation and thus is not moved relative to the packaging material.

[0026] The amplitude can be less than 10%, less than 1%, or less than 0.1% of the distance traveled.

[0027] With this embodiment, a vibrational movement with the highest possible frequency can be superimposed on the actual movement of the stamp, enabling the packaging material to follow the deformation over as much of the area of ​​the packaging material to be deformed as possible.

[0028] The frequency can be lower than the inverse of the relaxation time of the packaging material. This design ensures that the material deformation is as uniform as possible.

[0029] In one embodiment, the thermoforming packaging machine comprises a control unit, a heating element that heats the die during movement, and a temperature sensor, wherein the temperature sensor measures the temperature of the packaging material to be formed during movement, and wherein the control unit controls the frequency and / or amplitude of the oscillating motion depending on the measured temperature of the packaging material to be formed. This embodiment allows the oscillating motion to be controlled depending on parameters that can influence the forming of the packaging material.

[0030] In one embodiment, the control unit can regulate the frequency and / or amplitude of the vibration motion based on the measured temperature of the packaging material to be deformed, such that the temperature of the packaging material remains below a first limit and / or above a second limit during the movement. This preferably keeps the temperature of the packaging material within a range that allows for reliable deformation without damage, even of thin materials such as thin film webs.

[0031] All embodiments described here can be combined with each other. Brief description of the characters Fig. Figure 1 shows a schematic view of a thermoforming packaging machine according to one embodiment. Fig. Figure 2 shows a photograph with packaging material and a stamp according to one embodiment. Fig. 3, Fig. 4 to Fig. Figure 5 shows different sequences of the movement of the stamp with a superimposed oscillating movement according to one embodiment. Fig. Figure 6 shows a flowchart of a method for adjusting amplitude and frequency according to one embodiment. Detailed description

[0032] Fig. Figure 1 shows a thermoforming packaging machine 100 according to one embodiment. The thermoforming packaging machine 100 is shown here as comprising a lower tool 101 and an upper tool 102, which can be moved relative to each other. The lower tool can have at least one or a series of receptacles 111, the number, shape, and exact positioning of which within the lower tool are not specified. It is only provided that punches 121 corresponding to the receptacles 111 are arranged in the upper tool and can be moved relative to the receptacles 111. The movement of the punches 121 can be independent of the movement of the upper tool 102. The movement of the punches 121 can be caused at least partially or completely by the movement of the upper tool 102 in the direction of the lower tool 101. The upper tool and lower tool can also both be arranged to be movable relative to each other.

[0033] Furthermore, a control unit 180 is provided in this embodiment, which can control at least one function of the thermoforming packaging machine 100, such as the supply of heat and / or the movement of the punch 121.

[0034] While in the embodiment shown here six receptacles 111 and six corresponding punches 121 are arranged in the thermoforming packaging machine, it is understood that the invention is not limited in this respect. More or fewer, in particular any number of receptacles 111 and corresponding punches 121 can also be provided.

[0035] The thermoforming packaging machine is designed for forming or thermoforming packaging material, such as plastic or plastic films.

[0036] A feeder 151 can be assigned to the thermoforming packaging machine, which feeds packaging material 130 along a transport direction T of the thermoforming packaging machine. Such feeders are well known from the prior art. Devices for transferring the packaging material to the receiving units 111 are also known from the prior art. The fed packaging material 130 can, in particular, be in the form of a continuous film web or already provided as individual film pieces, which are then fed to the receiving units 111.

[0037] After the packaging material has been deep-drawn or formed by the deep-drawing packaging machine 100, a conveyor 152 can be provided to remove the formed packaging units 131 from the deep-drawing packaging machine. The formed packaging units 131 can, for example, be in the form of packaging trays into which a product, such as food, can subsequently be filled. The formed packaging material 131 can be either as separate, formed packaging parts or as a substantially continuous, formed packaging material 131 in which formed areas 131 have been created. The invention is not limited in this respect.

[0038] Fig. Figure 2 shows a view of a recording 111, regarding which packaging material 130 has already been placed according to the description. Fig. 1 was introduced.

[0039] In the embodiment shown here, a temperature sensor 270 is further assigned to the receptacle 111. This temperature sensor is preferably arranged or designed such that it can measure the temperature of the packaging material 130 arranged in the receptacle 111 as much as possible during the entire deformation process or at least during part of the deformation process.

[0040] According to the invention, the punch 121, together with the packaging material to be deformed, performs a movement 240. This movement essentially corresponds to a movement of the punch 121 towards the receptacle 111 and comprises the portion of the overall movement of the punch 121 from above the packaging material to the final position in the receptacle, in which the punch 121 is preferably in contact with the packaging material 130. This is shown here only schematically. At the beginning of this movement segment, in which the punch pushes the packaging material 130 towards the receptacle 111, the distance between the punch, or rather the surface of the punch facing the receptacle, and the packaging material 130 is zero, i.e., the punch and packaging material are in contact.

[0041] The movement 240 of the punch 121 towards the receptacle 111 until its final position, in which the packaging material 130 has preferably assumed the desired shape, extends over a distance H and takes a duration T. The punch does not have to move at a constant speed during the distance H and the duration T, but can also accelerate or decelerate during its movement.

[0042] This movement can be effected by a drive 241. This drive can be designed, for example, as a servo motor, electric motor, or pneumatic cylinder and be connected to the control unit 180 in such a way that the control unit 180 can control the drive or a first drive element of the drive 241 to effect a movement of the punch. It can be provided, for example, that the movement 240 of the punch 121 is also determined or controlled by the control unit depending on the temperature of the packaging material 230 measured by the temperature sensor 270.

[0043] The control unit 180 can include a memory in which information about the movement sequence of the stamp is stored, which may depend, for example, on the packaging material to be processed or on the shape of the packaging to be formed.

[0044] While in the embodiment shown here the receptacle 111 has a substantially trapezoidal cross-sectional area, with the longer of the two parallel side faces forming the opening of the receptacle into which the packaging material is inserted, the receptacle 111 is not limited with regard to its shape. Thus, the receptacle 111 can also have a cuboid shape, a cylindrical shape, a truncated cone shape, or any other irregular shape.

[0045] The stamp 121 has a corresponding surface, so that the insertion of the stamp into the receptacle 111 can lead to a deformation of the packaging material 130 into the desired shape.

[0046] A suction system 280 is shown schematically here, connected via one or more openings 281 to the interior of the receptacle 111, into which the packaging material is formed. The suction system 280 can further comprise a pump 282, in particular a vacuum pump, which can draw in the packaging material or the air located between the surface of the receptacle and the packaging material, thus advantageously influencing the forming of the packaging material. Alternatively or additionally, compressed air can also be supplied from above the packaging material. This can also prevent the packaging material from shrinking back.

[0047] The stamp 121 can further include a heating element 290 with which the stamp 121 can be heated to a desired temperature in order to achieve deformation of the packaging material.

[0048] The control unit 180 can be connected to the heating element 290 to control the heating element, for example to control its heating power and thus the temperature of the stamp 121 based on a measured temperature of the packaging material 130.

[0049] According to the invention, a vibrational movement 250 can be superimposed on the movement 240 of the punch 121. This vibrational movement essentially comprises a movement of the punch 121 towards and away from the receptacle 111 during its movement 240. This vibrational movement can be caused by the drive 241. Alternatively, the drive can comprise a first drive element that causes the movement of the punch by the distance H, and a second drive element or vibration generator 251 (for example, a servo motor, an actuator, or a pneumatic element) that can cause the vibrational movement superimposed on the movement 240. According to the invention, the vibrational movement 250 comprises an amplitude h that is smaller than the distance H and a frequency f that is greater than the inverse of the duration T of the movement.

[0050] According to the invention, the macroscopic movement 240 of the punch along the path H, in which the punch carries the packaging material 130 to be deformed towards the receiving 111, is superimposed by a microscopic (i.e. smaller) oscillating movement, in which the punch is at least briefly detached from the packaging material (in particular moved away from the receiving 111) and then moved again towards the receiving.

[0051] When the packaging material 130 is carried along, the superimposition of the movement 240 with the oscillating movement 250 ensures in particular that the packaging material can cool down temporarily during the release of the stamp 121 from the packaging material and / or can better follow the deformation of the packaging material sought by the stamp 121.

[0052] It can be provided that the frequency f is less than the inverse of the relaxation time of the packaging material 130. The relaxation time of the packaging material is the time that the packaging material, at least in certain areas, requires to follow the deformation imposed on the packaging material 130 by the punch during its movement 240, such that a material distribution, in particular material thickness, is achieved that is as uniform as possible. If the frequency is chosen to be less than the inverse of this relaxation time, the period of the vibration is greater than this relaxation time, so that the material has sufficient time during one period of the vibration 250 superimposed on the movement 240 to follow the deformation caused by the punch 121.Subsequently, the punch is moved further towards the receiving area according to movement 240, and a new period of oscillation can follow, so that the deformation of the packaging material caused by the further movement of the punch 121 during the period in which the punch is detached from the packaging material can also be followed.

[0053] Since the stamp 121 is not in contact with the packaging material for, e.g., only half of the period of the vibration movement, it can be particularly preferably provided that the frequency is less than 0.5Tr−1 can be, where T rThe relaxation time is specified. Therefore, the period is twice as long as the relaxation time. Thus, during half the period, when the stamp is not in contact with the packaging material, it is in contact for at least a time equal to the relaxation time, allowing the technical effect discussed above to be achieved.

[0054] Both the amplitude h and the frequency f of the oscillating motion 250 can be selected by the control unit 180, for example, depending on the distance H and / or the duration T, or depending on the motion parameters of the stamp. For instance, it can be specified that during a first time period Δt1, which is a subset of the duration T, the amplitude h and the frequency f assume the values ​​h1 and f1, respectively. During a second fraction Δt2 of the duration T, the amplitude h and the frequency f can assume the values ​​h2 and f2, where h1 and h2 as well as f1 and f2 do not have to be identical. For example, h1 could also be equal to h2, and only the frequencies f1 and f2 could differ, or vice versa. This allows the deformation process and the resulting forces acting on the packaging material to be taken into account.

[0055] For example, the frequency can be chosen to be higher in a section of the movement 240, in which the stamp 121 is already very close to its lowest point of movement in the direction of the recording 111, than at the beginning of the movement 240, in which the stamp 121 is just touching the packaging material 130.

[0056] The Fig. 3, Fig. 4 to Fig. Figure 5 schematically shows the movement sequence and behavior of the packaging material 130.

[0057] In Fig. Figure 3 shows a situation in which the packaging material 130 has already been compared with the representation in the stamp 121. Fig. 2 was moved in the direction of recording 111.

[0058] In this process, the packaging material 130 moves at least partially with the punch 121 and thereby undergoes a deformation, which can include, for example, a partial stretching and / or compression of the packaging material depending on the surface of the punch 121 and the direction of movement of the punch relative to the surface of the packaging material to be deformed.

[0059] This allows, as in Fig. Figure 3 schematically indicates that areas 331 and 332 of different thicknesses are formed in the packaging material 130 to be deformed. Since the punch 121 essentially carries the packaging material 130 with it during its movement 240 towards the receptacle 111, leveling or compensating for these areas 331 and 332 of different thicknesses in the packaging material is difficult without the oscillating movement 250 superimposed on the movement 240.

[0060] In Fig. 4. During its oscillating movement 250 with amplitude h and frequency f, the punch 121 is briefly lifted from the packaging material 130. This at least reduces the force exerted on the packaging material 130 by the punch 121 in the direction of the receptacle 111 or causes the punch 121 to detach from the packaging material 130. As a result, the packaging material previously moved by the punch 121, or at least subjected to a force, can adapt to the deformation imprinted by the punch in areas 331 and 332, such that the material thickness of the packaging material becomes uniform in the different areas 331 and 332. This is achieved in particular by the ability of, for example, plastic materials to flow when sufficient heat is applied.

[0061] Subsequently, the punch 121 can be moved again towards the packaging material and the movement 240 can continue towards the receiving 111, so that the packaging material 130 is formed. The oscillating movement 250 can superimpose itself on the actual movement 240 of the punch in such a way that the punch is moved further towards the receiving than the distance d(t) traveled at a given time t during movement 240, so that at time t, for example, the punch has traveled the distance d(t)+h / 2.

[0062] This ultimately leads to a movement of the stamp, which in Fig. 5 is shown schematically. Fig. Figure 5 shows a graph where the elapsed time t is shown on the horizontal axis and the distance traveled d(t) of the stamp is shown on the vertical axis as a function of the elapsed time t. In the embodiment shown here, the movement 240 of the stamp (the macroscopic movement, which is not yet superimposed with the oscillatory movement) is represented as a solid line running at an angle to the time axis. This movement 240 essentially corresponds to a movement with constant velocity, where the change Δd in the distance traveled, divided by the time δt required for this, yields the velocity v of the stamp. However, other, particularly non-linear, relationships d(t) are also conceivable, whereby preferably, at least during the duration of the movement T, which takes place between times t0 and t1, the function d(t) is monotonically increasing, such that the time derivative ∂d(t)∂t≥0 for all t within the interval t0 and t1.

[0063] As described, this movement is superimposed with an oscillatory movement 250, which is in the Fig. Figure 5 is essentially shown as a sequence of step functions. It is understood that the change in the position of the piston (the value d) corresponding to the superimposed oscillatory motion 250 cannot be changed instantaneously over a specific period of time. The representation therefore serves only as an illustration.

[0064] The oscillatory motion 250, superimposed on the motion 240, can be defined as its period by a time difference Δt between a first point and a subsequent point with the same properties (in particular, reversal points of the oscillatory motion where the velocity of the piston mediated by the oscillatory motion is 0). The frequency f = 1 / Δt.

[0065] The amplitude h is defined as the difference between the two turning points of the oscillatory motion in the direction of motion. Since the oscillatory motion 250 is superimposed on the motion 240, the dashed line is adapted to the course of the motion 240. It is understood that the oscillatory motion 250 itself can, however, be approximately defined as a sequence of step functions, in particular sequences of Heaviside functions, whose domains each comprise piecewise intervals of size Δt.

[0066] By superimposing this oscillatory motion onto the motion 240, the dashed line depicting the motion of the stamp is achieved, which during its motion, over the duration T, sometimes moves towards the recording and sometimes away from the recording.

[0067] It can be provided that the frequency f is an integer multiple of the inverse of the motion duration T, i.e., T = n · Δt, n ∈ ℕ. This ensures that, with respect to the oscillatory motion superimposed on motion 240, the punch occupies the same position in the sequence of the oscillatory motion at the beginning of the motion duration T (at time t0) as at time t1. In particular, it can be provided that the punch is in a state of oscillatory motion at both time t0 and time t1 in which the punch is moved in the direction of the receiving area, so that the packaging material to be deformed is deformed in the direction of the receiving area.

[0068] In the representation shown here of the Fig. Figure 5 shows the amplitude h in relation to the displacement H only as an example. Preferably, the amplitude h is much smaller than the displacement H, in particular less than 1%, preferably less than 0.1% of the displacement H. However, embodiments are also included in which the amplitude h is less than or equal to 10% of the displacement H. The determination of the amplitude h of the oscillating motion 250 can, for example, be chosen to be larger or smaller based on the necessary removal of the punch from the packaging material. If, for the reliable demolding of the packaging material, it is only necessary that the force acting on the packaging material be reduced, then the amplitude h can be small, e.g., 0.1% or less of the displacement H.If, for reliable shaping of the packaging material, it is necessary to at least temporarily remove or detach the punch 121 from the packaging material 130 to be deformed, the amplitude h can be chosen to be larger, e.g. 1% or up to 10% of the distance H.

[0069] Accordingly, the period Δt can also be (see above the explanations regarding Fig. 2, Fig. 3 to Fig. 4) depending on the properties of the packaging material.

[0070] Furthermore, the amplitude h and the frequency f of the oscillation (or the period Δt) can be controlled by the control unit 180 depending on a measured temperature of the packaging material and, for example, taking into account one or more limit values ​​(see Fig. 2) be controlled.

[0071] As already mentioned in reference to Fig. As described in section 2, the device can include a temperature sensor 270 that can determine the temperature of the packaging material. Depending on this, the control unit 180 can, for example, control the heating power of the heating element 290. Alternatively or additionally, it can also be provided that the amplitude and / or frequency of the oscillating motion 250 superimposed on the movement 240 is controlled in order to either increase or decrease the time during which the punch 121 is in contact with the packaging material to be deformed, thus ensuring that the packaging material cools down.

[0072] This shows Fig. 6 an exemplary embodiment of a corresponding method in the form of a flowchart.

[0073] The process 400 begins in step 401 with the start of the deformation process at time t0 (see Fig.5), i.e., the point in time at which the stamp 121 comes into contact with the packaging material.

[0074] In step 402, the temperature of the packaging material is measured, which can also heat up due to contact with the heated stamp 121.

[0075] In step 403, it is determined, for example, whether the measured temperature of the packaging material is below a first limit value. The first limit value can be a maximum temperature intended for the packaging material, which can be, for example, the melting point of the packaging material or be below the melting point of the packaging material. If, during this comparison, it is determined that the temperature is below the limit value (404), the procedure can be continued as described below.

[0076] If, instead, it is determined that the temperature of the packaging material is above the limit value 405, the control unit 180 can adjust the amplitude and / or frequency of the vibration in step 451 to different values. The deformation process is then continued with these newly set values ​​for the amplitude and / or frequency of the vibration, and the temperature of the packaging material is measured again. This adjustment can be repeated repeatedly over very short periods. For example, the temperature of the packaging material can be measured continuously at intervals of a few milliseconds, e.g., 2 ms or 10 ms, and the control unit can then perform step 403 to determine whether adjustment of the vibration is necessary.

[0077] If step 404 determines that the temperature of the packaging material is below the first limit value, step 406 may optionally include a comparison of the measured temperature of the packaging material to be deformed with a second limit value. The second limit value is preferably lower than the first limit value and may, for example, define a minimum temperature for deforming the packaging material.

[0078] If, in step 406, it is determined that the temperature is above the second limit value (408), then the temperature of the packaging material is between the first and second limit values ​​and thus within a permissible range defined by the limit values. In step 481, the deformation process can then be continued without changing the amplitude and / or frequency of the vibration, so that a new measurement of the packaging material's temperature can follow in step 402, and the entire process can then be repeated.

[0079] If, in step 406, it is determined that the temperature is not above the second limit value (407), the control unit can determine that the temperature of the packaging material to be deformed is too low. In step 471, the control unit can then change the amplitude and / or frequency of the vibration (for example, decrease the amplitude while keeping the frequency constant), so that, for example, the contact time between the punch and the packaging material is increased, which leads to increased heat input and can raise the temperature of the packaging material.

[0080] The deformation process is then continued with these new values ​​for the amplitude and / or frequency of the vibration motion, and it can be determined by measuring the temperature of the packaging material again in accordance with step 402 whether the packaging material has now reached the necessary temperature.

[0081] As mentioned previously, step 406, and therefore steps 407, 408, and 471, are optional. The procedure may simply involve comparing the measured temperature of the packaging material with the first limit value according to step 403. If the temperature of the packaging material is below the first limit value (404), the deformation process can continue with the original parameters for amplitude and / or frequency of the vibration according to step 481. If, instead, the comparison reveals that the temperature is above the limit value (405), step 451 can follow.

[0082] Alternatively, it may be stipulated that only steps 406, 407, 408, and 471 are performed, i.e., that the vibration is controlled based on a measurement of whether the temperature of the packaging material being deformed is above the second limit value. If so, the deformation process continues according to step 481 with the vibration amplitude and frequency unchanged. Otherwise, the amplitude and / or frequency can be readjusted.

[0083] Alternatively, steps 406 and 403 can be swapped, meaning that first it is determined whether the temperature of the packaging material is above the second limit value, and then it is determined whether the temperature is below the first limit value. Subsequently, the amplitude and / or frequency can be adjusted according to steps 451 and / or 471.

Claims

[1] Thermoforming packaging machine (100) for forming packaging material (130), the thermoforming packaging machine comprising a receptacle (111) for receiving packaging material, a punch (121) movable in the receptacle in the direction of the packaging material to be formed, and a drive (241) for driving the punch (121), wherein the drive (241) is configured to superimpose a vibrational movement (250) of the punch in the direction of the movement (240) and against the direction of the movement (240) on a movement (240) of the punch during contact between the punch and the packaging material (130), wherein the vibrational movement has an amplitude (h) that is smaller than the distance (H) traveled by the punch (121) during the movement (240), and wherein the vibrational movement has a frequency (f) that is greater than the inverse of the duration (T) of the movement (240). [2] Thermoforming packaging machine (100) according to claim 1, wherein the drive (241) comprises a first drive element (241), such as a first servo motor, an electric motor or a pneumatic cylinder, for effecting the movement (240) and a vibration generator (251) for effecting the vibration movement (250). [3] Thermoforming packaging machine (100) according to claim 1, wherein the drive (241) comprises exactly one drive element, such as a servo motor, an electric motor or a pneumatic cylinder, which can effect the movement (240) and the vibration movement (250). [4] Thermoforming packaging machine (100) according to one of claims 1 to 3, wherein the frequency (f) is an integer multiple of the inverse of the duration (T) of the movement. [5] Thermoforming packaging machine (100) according to any one of claims 1 to 4, wherein the amplitude (h) is less than 10% or less than 1% or less than 0.1% of the path distance (H). [6] Thermoforming packaging machine (100) according to one of claims 1 to 5, wherein the frequency (f) is less than the inverse of a relaxation time of the packaging material (130). [7] Thermoforming packaging machine (100) according to any one of claims 1 to 6, wherein the thermoforming packaging machine (100) comprises a control unit (180), a heating element (290) for heating the punch (121) during the movement (240), and a temperature sensor (270) configured to measure the temperature of the packaging material (130) to be formed during the movement (240), wherein the control unit (180) is configured to control the frequency (f) and / or the amplitude (h) of the oscillating movement (250) depending on the measured temperature of the packaging material (130) to be formed. [8] Thermoforming packaging machine (100) according to claim 7, wherein the control unit (180) is configured to control the frequency (f) and / or the amplitude (h) of the oscillating movement (250) depending on the measured temperature of the packaging material (130) to be deformed, such that the temperature of the packaging material to be deformed during the movement is below a first limit and / or above a second limit. [9] Method for forming packaging material (130) with a thermoforming packaging machine (100), the thermoforming packaging machine (100) comprising a receptacle (111) for receiving packaging material (130), a punch (121) movable in the receptacle in the direction of the packaging material to be formed, and a drive (241) for driving the punch (121), wherein the drive is configured to superimpose a vibrational movement (250) of the punch (121) in the direction of the movement (240) and against the direction of the movement (240) on a movement (240) of the punch (121) during contact between the punch and the packaging material (130), wherein the vibrational movement (250) has an amplitude (h) that is smaller than the distance (H) traveled by the punch during the movement (240), and wherein the vibrational movement (250) has a frequency (f) that is greater is the inverse of the duration (T) of the movement (240),the procedure includes: - a movement of the stamp (121) together with the packaging material (130) during the deformation of the packaging material and - Superimposing the motion (240) with the oscillatory motion (250). [10] Method according to claim 9, wherein the drive (241) comprises a first drive element (241), such as a first servo motor, an electric motor or a pneumatic cylinder, which causes the movement, and a vibration generator (251) which causes the vibration movement (250); or wherein the drive (241) comprises exactly one drive element, such as a servo motor, an electric motor or a pneumatic cylinder, which causes the movement (240) and the vibration movement (250). [11] Method according to claim 9 or 10, wherein the frequency (f) is an integer multiple of the inverse of the duration (T) of the motion. [12] Method according to any one of claims 9 to 11, wherein the amplitude (h) is less than 10% or less than 1% or less than 0.1% of the distance (H). [13] Method according to any one of claims 9 to 12, wherein the frequency (f) is less than the inverse of a relaxation time of the packaging material (130). [14] Method according to any one of claims 9 to 13, wherein the thermoforming packaging machine (100) comprises a control unit (180), a heating element (290) which heats the punch (121) during the movement (240), and a temperature sensor (270), wherein the temperature sensor measures a temperature of the packaging material (130) to be formed during the movement (240), wherein the control unit (180) controls the frequency (f) and / or the amplitude (h) of the oscillating movement (250) depending on the measured temperature of the packaging material (130) to be formed. [15] Method according to claim 14, wherein the control unit (180) controls the frequency (f) and / or the amplitude (h) of the vibrational movement (250) depending on the measured temperature of the packaging material (130) to be deformed such that the temperature of the packaging material (130) to be deformed during the movement (240) is below a first limit and / or above a second limit.

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