Sealing device for packaging machine, packaging machine having a sealing device, and method of operating the sealing device

Abstract

A sealing apparatus (20) for sealing packages (2) filled with a pourable product in a packaging machine (1) is described. The sealing apparatus (20) comprises one or more sonotrodes (21), the sonotrode (21) comprising a sonotrode head (23) and a vibration control unit (25) connected to the sonotrode head (23) and configured to activate ultrasonic vibrations of the sonotrode head (23). The vibration control unit (25) comprises one or more piezoelectric transducing devices (35) configured to generate ultrasonic vibrations coupled to the sonotrode head (23) and one or more temperature sensors (36) configured to measure the temperature of the one or more piezoelectric transducing devices (35) to determine and / or monitor a respective operating condition of the one or more piezoelectric transducing devices (35).

Description

TECHNICAL FIELD

[0001] The present invention relates to a sealing device for sealing, in particular transversely sealing, packages, in particular composite packages, in a packaging machine for packaging pourable products, in particular pourable food products.

[0002] Advantageously, the present invention also relates to a packaging machine for packaging pourable products, in particular pourable food products, into packages, in particular composite packages, said packaging machine having at least one sealing device for sealing the packages.

[0003] Furthermore, the present invention also relates to a method for operating a sealing device in a packaging machine for packaging pourable products, in particular pourable food products, into packages, in particular composite packages.

BACKGROUND ART

[0004] As is well known, many liquid or pourable food products, such as fruit juices, UHT (ultra-high temperature processed) milk, wine, tomato sauce and the like, are sold in packages made of sterilized packaging material, in particular hermetically sealed packages.

[0005] A typical example is the pourable parallelepiped-shaped package known as Tetra Brik Aseptic (registered trademark), which is produced by sealing and folding a laminated strip-shaped packaging material. This packaging material has a multilayer structure comprising a base layer of carton and / or paper, with both sides covered by layers of heat-sealable plastic material, for example polyethylene. In the case of aseptic packages for long-shelf-life products, the packaging material comprises a layer of oxygen barrier material, for example aluminum foil, which is superimposed on a layer of heat-sealable plastic material and further covered by another layer of heat-sealable plastic material, which ultimately forms the inner face of the package that comes into contact with the food product.

[0006] This type of packaging is typically manufactured using a fully automated packaging machine, which sterilizes the web of packaging material during use by advancing it through the machine's sterilization unit. The sterilized web of packaging material is then maintained within an isolation chamber and advances, where it is folded longitudinally and sealed to form a tube, which then advances further. The tube is then filled with a pourable product and, as the tube advances, is sealed laterally along equally spaced transverse sections within the packaging machine's packaging forming unit and cut.

[0007] More specifically, the package molding apparatus comprises multiple molding and sealing assemblies, each assembly molding, laterally sealing, and cutting a tube to obtain a single package when in use.

[0008] Each molding and sealing assembly is equipped with a sealing device for lateral sealing the tube to obtain its respective lateral seal portion by locally compressing the tube and heating each portion of the layer of heat-sealable plastic material. Heating may be performed, for example, using a sealing device that generates ultrasonic vibrations.

[0009] An ultrasonic vibration-heating sealing device comprises a sonotrode configured to generate ultrasonic vibrations and an anvil designed to cooperate with the sonotrode to locally compress a tube.

[0010] A typical sonotrode comprises a sonotrode head having a sealing surface extending along its longitudinal axis, and a vibration control unit connected to the sonotrode head and configured to actuate the ultrasonic vibrations of the sonotrode head.

[0011] More specifically, the vibration control unit comprises a housing shell and one or more piezoelectric converters located within the housing shell and configured to generate ultrasonic vibrations, which are coupled to a sonotrode head.

[0012] Piezoelectric converters are known to have a shortened lifespan due to aging, and the entire sonotrode, or at least the piezoelectric converter, must be replaced according to pre-established maintenance procedures.

[0013] Despite the fact that known sealing devices operate with high quality and reliability, there is a demand in this field for further improvements to known sealing devices.

[0014] In particular, there seems to be a desire to use each sonotrode for as long as possible and avoid undesirable malfunctions. [Overview of the project] [Problems that the invention aims to solve]

[0015] Therefore, an object of the present invention is to provide an improved sealing device that is simple and low-cost.

[0016] A further object of the present invention is to provide a packaging machine having an improved sealing device in a simple and low-cost manner.

[0017] Furthermore, an object of the present invention is to provide an improved method for operating a sealing device in a simple and low-cost manner.

[0018] According to the present invention, a sealing device as described in independent claim 1 is provided.

[0019] Preferred embodiments of the sealing device are described in the claims directly or indirectly dependent on claim 1.

[0020] According to the present invention, the packaging machine described in claim 11 is also provided.

[0021] Furthermore, the present invention also provides the method described in claim 12.

[0022] Preferred embodiments of the present method are recited in the claims directly or indirectly dependent on claim 12. [MEANS FOR SOLVING THE PROBLEMS]

[0023] Hereinafter, embodiments of the present invention will be described by way of example with reference to the accompanying drawings. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0024] [Figure 1] This is a schematic view of a packaging machine having at least one sealing device according to the present invention, with parts removed for clarity. [Figure 2] This is a schematic view showing details of the packaging machine of Figure 1 including a portion of the sealing device according to the present invention, with parts removed for clarity. [Figure 3] This is a side view of a portion of the sealing device of Figure 2, with parts removed for clarity. [Figure 4] This is an enlarged perspective view of a portion of Figure 3, with parts removed for clarity. [Figure 5] This is a side view of a portion of the sealing device of Figure 2 according to one or more embodiments, with parts removed for clarity. [MODES FOR CARRYING OUT THE INVENTION]

[0025] Reference numeral 1 generally denotes the entire packaging machine for producing sealed packages 2 of pourable products, in particular pourable food products such as (pasteurized) milk, fruit juice, wine, tomato sauce, salt, sugar and the like.

[0026] More specifically, the packaging machine 1 may be configured to produce the composite packages 2 from a composite multilayer packaging material.

[0027] More specifically, the packaging material may comprise, for example, at least one layer of fibrous material such as paper or cardboard, and at least two layers of heat-sealable plastic material, such as polyethylene, with the fibrous material layers interposed between them. One of these two layers of heat-sealable plastic material defines the inner surface of the body 2 that comes into contact with the pourable product.

[0028] Furthermore, the packaging material may include a layer of gas barrier and light barrier material, such as aluminum foil or ethylene vinyl alcohol (EVOH) film, which is interposed between one of the heat-sealable plastic material layers and a fibrous material layer. Preferably, the packaging material may include a further layer of heat-sealable plastic material interposed between the gas barrier and light barrier material layer and the fibrous material layer.

[0029] More specifically, the packaging material may be provided in the form of a web 3.

[0030] Furthermore, the packaging machine 1 may be configured to produce the package 2 by forming a tube 4 from the web 3, sealing the tube 4 longitudinally, filling the tube 4 with a pourable product, sealing the tube 4 transversely, and cutting it.

[0031] A typical package 2 produced by the packaging machine 1 comprises a longitudinal seam 5 and, in particular, pairs of first transverse sealing bands and second transverse sealing bands positioned on opposing sides of the package 2. Specifically, the first transverse sealing band may define a transverse upper sealing band, and the second transverse sealing band may define a transverse bottom sealing band.

[0032] Referring to Figure 1, the packaging machine 1 is - A conveying device 7 that advances the web 3 along the web advance path P to the molding station 8 (in a known manner), - An isolation chamber 9 having an internal environment, particularly an internal sterile environment containing sterile gases, and separated from the (hostile) external environment, - A tube forming and sealing device 10 is configured to form a tube 4 from a web 3 that advances within an internal environment during use, and to seal the tube 4 longitudinally within the internal environment. - A filling device 11 for continuously filling a tube 4 with a pourable product, - A package forming apparatus 12 configured to form a forward tube 4 for forming package 2, seal it laterally, and cut it laterally, It may be provided.

[0033] Furthermore, the packaging machine 1 may also include a sterilization unit configured in the sterilization station to sterilize the advancing web 3 during use, and in particular, the sterilization station may be located upstream of the molding station 8 along the web advancement path P.

[0034] More specifically, the conveying device 7 may be configured to advance the tube 4 and any intermediates of the tube 4 along the tube advance path Q from the molding station 9 to the package molding device 16. In particular, below the intermediates of the tube 4 means any configuration of the web 3 before obtaining the tube structure and after the folding of the web 3 by the tube molding sealing device 10 has begun. In other words, the intermediate portion of the tube 4 is the result of gradually folding the web 3 to obtain the tube 4, in particular by overlapping the ends of the web 3 with each other.

[0035] Preferably, the tube forming and sealing device 10 may be positioned so that the tube 4 is oriented vertically.

[0036] More specifically, the tube forming and sealing device 10 may include at least two forming ring assemblies 16 located within the isolation chamber 9, which may be configured to cooperate with each other to gradually fold the web 3 into the tube 4 by overlapping the edges of the web 3 with each other. This forms a seam 5 of the tube 3 when in use.

[0037] Furthermore, the tube forming and sealing apparatus 10 may include a sealing head 17, which is located within the isolation chamber 9 and is configured to seal the tube 4 longitudinally along the seam portion 5.

[0038] Furthermore, the tube forming and sealing device 10 may include a pressing assembly configured to apply mechanical force to the seam portion 5 to ensure that the tube 4 is sealed along the seam portion 5.

[0039] Furthermore, the filling device 11 may include a filling pipe 18 configured to guide the pourable product into the tube 4 during use. In particular, the filling pipe 18 may be at least partially located inside the tube 4 to supply the pourable product into the tube 4 during use.

[0040] Referring to Figures 1 and 2, the package molding apparatus 12 is - Multiple molding and sealing assemblies 19 (shown only partially in Figure 2 to the extent necessary for understanding the present invention), each molding and sealing assembly is configured to at least mold a tube 4, seal the tube 4 laterally, and in particular cut the tube 4 laterally as well. - A transport unit (not shown, known) for advancing the molding and sealing assembly 19, It may be provided.

[0041] In particular, the package molding apparatus 12 is configured to control the molding and sealing assembly 19 and the transport unit to seal and cut the tubes 4 laterally along the lateral cross-sections which are arranged at equal intervals.

[0042] More specifically, each molding and sealing assembly 19 is: - A molded shell (not shown, known) configured to define at least partially the shape of package 2, -A sealing device 20 configured to compress at least laterally, and in particular to squeeze it flat, thereby sealing the tube 4 laterally, It may be provided.

[0043] Furthermore, each molding and sealing assembly 19 may be equipped with a cutting device (not shown) for cutting the tube 4 laterally.

[0044] In particular, each sealing device 20 is configured to form a main sealing band, and each cutting device is configured to cut the main sealing band laterally. More specifically, each main sealing band connects the respective first lateral sealing band of the preceding package 2 and the respective second lateral sealing band of the following package 2.

[0045] More specifically, each molded shell may comprise at least a first half-shell (not shown, known) and a second half-shell (not shown, known) configured to cooperate at least partially to define the shape of the package 2. In particular, the first half-shell and the second half-shell are configured to contact the tube 4 from both sides.

[0046] More specifically, each sealing device 20 is of the ultrasonic type. That is, the sealing device 20 is configured to generate ultrasonic vibrations suitable for heating a portion of the layer of heat-sealable plastic material.

[0047] Furthermore, each sealing device 20 has at least, - A sonotrode 21 for generating ultrasonic vibrations, in particular for heating / melting each portion of the layer of heat-seal plastic material, -In cooperation with the sonotrode 21 and tube 4, the anvil 22 for compression, in particular for locally flattening and squeezing, It may be provided.

[0048] More specifically, each cutting device is equipped with at least one movable blade for cutting the tube 4 laterally.

[0049] Furthermore, each sonotrode 21 is associated with its respective first half-shell, and in particular defines a first operating section of each molding and sealing assembly 19, and each anvil 22 is associated with its respective second half-shell, and in particular defines a second operating section of each molding and sealing assembly 19.

[0050] Furthermore, each blade of each cutting device is associated with each sonotrode 21 or each anvil 22 (specifically, each anvil 22). In other words, each cutting device is associated with each first operating unit or each second operating unit, specifically each second operating unit.

[0051] Furthermore, the transport unit may be configured to advance each first operating section along a first path and each second operating section along a second path.

[0052] Furthermore, each first operating section and each second operating section may be configured to cooperate with each other to form package 2 as they move along the respective operating sections of the first and second paths.

[0053] Referring to Figures 3 and 4, each sonotorode 21 is at least, - In particular, a sonotrode head 23 having a sealing surface 24 extending along the longitudinal axis A, - A vibration control unit 25 connected to the sonotrode head 23 and configured to activate the ultrasonic vibrations of the sonotrode head 23, It is equipped with.

[0054] More specifically, each sealing surface 24 may be designed to contact the tube 4 and establish an operational connection with a portion of the heat-seal plastic layer.

[0055] Furthermore, each sealing surface 24 may include a first portion 26 and a second portion 27 that are spaced apart from each other and arranged parallel to each other.

[0056] Furthermore, each sonotorode head 23 may include a groove 28 interposed between each first portion 26 and each second portion 27. In particular, each groove 28 is designed to receive a portion of each blade when cutting the tube 4 laterally.

[0057] Referring to Figures 2 to 4, each vibration control unit 25 may include one or more piezoelectric converters 35 (shown in Figures 3 and 4) configured to generate ultrasonic vibrations coupled to their respective sonotrode heads 23. In the illustrated example, the vibration control unit 25 includes three piezoelectric converters 35, but the number may vary depending on the type of package 2. That is, depending on the type of package 2, the extended portion of the sealing surface 24 may be large or short. In particular, when the sealing surface 24 is short, fewer piezoelectric converters 35 are required than when it is large.

[0058] Furthermore, each vibration control unit 25 may include one or more temperature sensors 36 configured to measure (directly or indirectly) the temperature of the piezoelectric transducer 35 in order to determine and / or control the operating state of each of the piezoelectric conversion devices 35.

[0059] In particular, the applicant observed that the temperature of each piezoelectric converter 35 indicates the operating characteristics of the piezoelectric converter 35, and / or the degradation of the piezoelectric converter 35 over time, and / or the remaining lifespan of the piezoelectric converter 35. For example, the applicant found that each piezoelectric converter 35 degrades over time as a result of its operation, leading to increased heat dissipation during use.

[0060] Preferably, the temperature sensor 36 is configured to continuously and / or in real time measure the temperature of the piezoelectric converter 35, and in particular to continuously and / or in real time determine and / or monitor the operating state of the piezoelectric converter 35.

[0061] In the illustrated example, at least one temperature sensor 36 is associated with each piezoelectric converter 35 to measure its temperature and determine and / or monitor the operating state of each piezoelectric converter 35.

[0062] According to some possible embodiments, each temperature sensor 36 is connected to its respective piezoelectric converter 35 to (directly) measure its respective temperature.

[0063] Alternatively, each temperature sensor 36 can determine its own temperature in non-contact mode.

[0064] According to several possible alternative embodiments, it is also possible to determine the temperature of the piezoelectric converter 35 by the average temperature of each piezoelectric converter 35 of each sealing device 20.

[0065] More specifically, each temperature sensor 36 may be a thermistor. That is, the temperature determined by the temperature sensor 36 arises from the change in the resistance value of the temperature sensor 36.

[0066] More specifically, each temperature sensor 36 may be a negative temperature coefficient (NTC) thermistor (i.e., its resistance decreases as the temperature rises) or a positive temperature coefficient (PTC) thermistor (i.e., its resistance increases as the temperature rises).

[0067] It should be noted that the accuracy of this type of temperature sensor 36 is approximately + / - 0.5°C. Therefore, this accuracy is limited compared to other types of temperature sensors. However, the applicant has found that the accuracy provided by thermistors, particularly NTC thermistors and PTC thermistors, is sufficient to determine and / or monitor the operating state of the piezoelectric conversion device 35. Thus, by using thermistors, particularly NTC thermistors and PTC thermistors, a more economical solution can be obtained compared to other types of temperature sensors, which are more expensive but reliably determine the operating state of the piezoelectric conversion device 35.

[0068] Referring to Figure 4, each piezoelectric conversion device 35 may comprise a plurality of piezoelectric (ceramic) elements 37 stacked on top of each other. More specifically, each piezoelectric conversion device 35 may comprise a plurality of conductive metal sheets, and in particular, a laminate may be formed by alternately stacking piezoelectric elements 37 and conductive metal sheets together with the piezoelectric elements 37. Preferably, each temperature sensor 36 may be configured to measure the temperature of each piezoelectric element 37.

[0069] Furthermore, each sealing device 20, in particular each vibration control unit 25, may include one or more generators (not shown, known) operably connected to the piezoelectric converter 35, in particular the piezoelectric element 37, in order to operate and control the ultrasonic vibrations of the piezoelectric converter 35.

[0070] Furthermore, each piezoelectric converter 35 may include at least one metal connector 38, in particular connected to one conductive metal sheet, designed to establish an electrical connection with at least one generator. Specifically, each vibration control unit 25 includes one or more electrical cables 39 connected to at least one generator and at least one metal connector 38 to establish an electrical connection between the generator and the metal connector 38.

[0071] Advantageously, each temperature sensor 36 makes contact with the respective metal connector 38 of the respective piezoelectric converter 35 (to establish contact with the respective piezoelectric converter 35).

[0072] Preferably, each metal connector 38 may be made of copper in particular. Because copper has excellent thermal properties, this ensures that the temperature determined by each temperature sensor 36 corresponds to the temperature of each piezoelectric conversion device 35, in particular, each piezoelectric element 37.

[0073] According to some possible non-limiting embodiments, the packaging machine 1, in particular the package molding machine 12, may include at least one analysis unit 40 operably coupled to a temperature sensor 36 and configured to monitor and / or determine the operating state of a piezoelectric converter 35 in accordance with the temperature determined by the temperature sensor 36.

[0074] According to some possible non-limiting embodiments, each sealing device 20 comprises a portion of an analysis unit 40 operably connected to a respective temperature sensor 36 to determine the temperature of the respective piezoelectric converter 35, and in particular, each portion of the analysis unit 40 is configured to monitor and / or determine the operating state of the piezoelectric converter 35 in accordance with the temperature determined by the temperature sensor 36.

[0075] Furthermore, the analysis unit 40 and / or parts of the analysis unit 40 may be configured to plan maintenance activities based on the operating state of the piezoelectric converter 35. In particular, the analysis unit 40 and / or parts of the analysis unit 40 may be configured to plan maintenance activities as a function of the remaining lifespan and / or aging degradation of the piezoelectric converter 35. In this way, the use of the piezoelectric converter 35 can be optimized.

[0076] For example, each analysis unit 40 and / or part of the analysis unit 40 may signal the remaining lifespan of the piezoelectric converter device 35 and indicate that maintenance should be performed within a specific time frame.

[0077] Furthermore, the analysis unit 40 and / or parts of the analysis unit 40 may be configured to assess the likelihood of an abnormal operating condition occurring based on the temperature measured by the temperature sensor 36. Furthermore, the analysis unit 40 and / or parts of the analysis unit 40 may be configured to warn of the risk of an abnormal operating condition, for example, by prompts and / or audible messages and / or similar electronic messages on the human-machine interface (of the packaging machine 1).

[0078] Furthermore, each vibration control unit 25 may include at least a housing shell 41 (shown in Figure 3; the transparent display is for illustrative purposes only) having an internal space 42. In particular, the housing shell 41 is in contact with each sonotrode head 23 so as to seal the internal space 42 from the external space.

[0079] Preferably, each piezoelectric conversion device 35 and each temperature sensor 36 are arranged within their respective internal spaces 42. In particular, each generator may also be arranged within its respective internal space 42.

[0080] Furthermore, each vibration control unit 25 may include a coupling portion 43 that contacts each sonotrode head 23 along its respective contact surface. Additionally, each piezoelectric conversion device 35 may be positioned within each sheet 44 (see Figure 3 in particular) of each coupling portion 43 and in contact with the coupling portion 43 so as to transmit the generated ultrasonic vibrations to each sonotrode head 23.

[0081] During use, packaging machine 1 produces packages 2 filled with a pourable product.

[0082] More specifically, the conveying device 7 advances the web 3 along the web advance path P to the forming station 8. The tube forming and sealing device 10 forms the tube 4 from the advancing web 3 and seals the tube 4 longitudinally. Furthermore, the filling device 11 fills the tube 4 with a pourable product, and the packaging device 12 forms the tube 4, seals it laterally, and cuts it laterally to obtain the package 2.

[0083] More specifically, while the package molding unit 12 is in operation, the molding and sealing assembly 19 molds, seals laterally, and cuts the tubes 4 in particular laterally in order to obtain each filled package 2.

[0084] Thus, the molding is carried out by each molding shell, in particular by the cooperation of each first half shell and the second half shell.

[0085] Furthermore, lateral sealing is performed by each sealing device 20.

[0086] Furthermore, lateral cutting is performed by each individual cutting device.

[0087] More specifically, the operation of each sealing device 20 is as follows: - Through the cooperation of each anvil 22 and each sonotrode 21, the tube 4 is compressed, in particular, in the step of squeezing it to make it flat, - A step of generating ultrasonic vibrations with Sonotrode 21 to heat a portion of the heat-seal plastic layer, It must have at least the following:

[0088] More specifically, the operation of each sealing device 20 is as follows: a) The vibration control unit 25 and the respective piezoelectric conversion devices 35 are operated to excite ultrasonic vibrations in each sonotrode head 23, b) A step of measuring the temperature of each piezoelectric conversion device 35, c) In particular, the analysis unit 40 and / or each part of the analysis unit 40 determine the operating state of each piezoelectric converter 35 based on the temperature obtained in step b), To further prepare.

[0089] More specifically, during each step b), the temperature of each piezoelectric converter 35 may be measured by its respective temperature sensor 36, and during step c), the operating state of each piezoelectric converter 35 may be determined according to the respective temperature determined during each step b).

[0090] Preferably, steps b) and c) may be performed consecutively.

[0091] Furthermore, the operation of each sealing device 20 may further include a transfer step in which the measurement results of the temperature sensor 36 are transferred to the analysis unit 40 and / or to each part of the analysis unit 40.

[0092] More specifically, in step c), the remaining lifespan and / or degradation over time of the piezoelectric conversion device 35 may be estimated.

[0093] Furthermore, the operation of each sealing device 20 may further include the step of d) planning maintenance based on the operating status of one or more piezoelectric converters 35. In particular, in this way, maintenance can be planned based on the effective remaining life and / or deterioration over time of the piezoelectric converters 35.

[0094] Furthermore, the operation of each sealing device 20 may include a warning step during which the hazard of an abnormal working condition may be communicated, for example, by a prompt on a human-machine interface and / or an audible message and / or a similar electronic message.

[0095] The advantages of the sealing device 20 and / or the packaging machine 1 and / or the method according to the present invention will be apparent from the above description.

[0096] In particular, by providing a temperature sensor 36, it is possible to measure the temperature of the piezoelectric converter 35 and monitor and / or determine the operating state of the piezoelectric converter 35 according to the measured temperature. In this way, it is possible to monitor whether the piezoelectric converter 35 is operating correctly and / or determine the remaining lifespan and / or degradation of the piezoelectric converter. This makes it possible to decide whether or not to perform maintenance activities based on the actual degradation of the piezoelectric converter 35, without having to follow a predetermined schedule. This ensures that undesirable failures and unnecessary maintenance activities can be avoided.

[0097] A further advantage lies in the possibility of obtaining real-time data on the operating status of the piezoelectric conversion device 35, which enables a rapid response and further reduces the risk of malfunctions that are presumed to interfere with the proper operation of the sealing device 20.

[0098] Another advantage is that the temperature sensor 36 is connected to its respective metal connector 38, which is already used to connect the piezoelectric converter device 35, in particular the piezoelectric element 37, to its respective generator via its respective electrical cable 39. In this way, space requirements are optimized.

[0099] A further advantage lies in using a thermistor as the temperature sensor 36. Thermistors are relatively inexpensive and easy to install. Furthermore, their accuracy is sufficient for specific applications.

[0100] However, without departing from the scope of protection defined in the appended claims, modifications can obviously be made to the sealing device 20 and / or the packaging machine 1 and / or method as described herein.

[0101] Accordingly, one or more embodiments relate to a sealing device 20 for sealing a package 2 filled with a pourable product within a packaging machine 1, a portion of which is shown in Figure 5. Reference numerals used in reference to Figure 5 have the same meaning and refer to the same features as reference numerals used previously in reference to the remaining figures.

[0102] The sealing device 20 has at least one sonotrode 21, which consists of at least a sonotrode head 23 and a vibration control unit 25 connected to the sonotrode head 23 and configured to actuate the ultrasonic vibration of the sonotrode head 23.

[0103] As shown in Figure 5, the vibration control unit 25 is - One or more piezoelectric converters 35 configured to generate ultrasonic vibrations coupled to the sonotrode head 23, -One or more electrical cables 39 configured to supply power (e.g., electrical connection and power supply) to each of the one or more piezoelectric converter devices 35, and one or more electrical cables 39 connected to each of the one or more piezoelectric transducer devices 35 via a first end 39b, -One or more temperature sensors 36 configured to measure the temperature of one or more piezoelectric converters 35 (e.g., directly or indirectly) in order to determine and / or monitor the operating state of one or more piezoelectric converters 35 by measuring the temperature of the first end 39b of one or more electrical cables 39, It may be provided.

[0104] In other words, the temperature sensor 36 may be configured to measure the temperature of the first end 39b of the electrical cable 39, which indicates the temperature of each piezoelectric converter 35. In this way, a reliable, accurate, and secure measurement of the temperature of the piezoelectric converter 35 can be obtained without direct contact with the piezoelectric converter 35. In particular, the temperature at the first end of the electrical cable 39 closest to the piezoelectric converter 35 is very similar to the temperature of the piezoelectric converter 35, and therefore it is possible to obtain an accurate measurement of the temperature of the piezoelectric converter 35. The embodiment shown in Figure 5 may be advantageous in that it is particularly robust when considering vibrations of the piezoelectric converter 35.

[0105] One or more temperature sensors 36 may be placed at the first end 39b of each of the one or more electrical cables 39.

[0106] Each electrical cable 39 may comprise a wire and a protective sheath 39a surrounding the wire. As shown in Figure 5, one or more temperature sensors 36 may be positioned, for example, at the first end 39b, between the protective sheath 39a and the electrical wire of each of the one or more electrical cables 39.

[0107] For example, one or more temperature sensors 36 may be completely or partially covered by the protective sheath 39a of each of the one or more electrical cables 39. For example, the temperature sensor 36 may be pressed against the electrical wiring by the sheath 39a and / or kept in contact with the electrical wiring. Similarly, for example, the electrical cable 360 ​​supplying power to the temperature sensor 36 may be positioned between the protective sheath 39a and the wires of each of the one or more electrical cables 39, and may be completely or partially covered by the protective sheath 39a.

[0108] More specifically, each electrical cable 39 is connected to at least one generator to establish an electrical connection between the generator and the metal connector 38, and at its first end 39b, it may be connected to at least one metal connector 38 of the piezoelectric converter 35. A temperature sensor 36 may be configured to measure the temperature of the first end 39b, such a temperature indicating the temperatures of the piezoelectric converter 35 and the metal connector 38. In this way, it is possible to measure the temperature of the first end of the electrical cable 39 instead of measuring the temperature of the metal connector 38, and a reliable, robust, and accurate measurement of the temperature of the piezoelectric converter 35 can be obtained.

[0109] The temperature measurement obtained by the temperature sensor 36 of the first end 39b of the electrical cable 39 may indicate the temperature of each of the one or more piezoelectric converters 35. The analysis unit 40, -Receive one or more temperatures measured at the first end 39b of one or more electrical cables 39, -The system may be configured to calculate the temperature of one or more piezoelectric converters 35 as a function of one or more measured temperatures and, preferably, a correction factor, such as a linear correction factor.

[0110] To avoid misunderstanding, it should be noted that each piezoelectric converter 35 has its own electrical cable 39 that supplies power to it. Furthermore, each temperature sensor 26 may be located at the end 39b of its respective electrical cable 39. That is, each temperature sensor 36 is associated (e.g., in contact with or in close proximity to) a single electrical cable 39 and a single piezoelectric converter 35.

Claims

1. A sealing device (20) for sealing a package (2) filled with a product that can be poured into a packaging machine (1), The sealing device (20) has at least one sonotrode (21), The aforementioned sonotrode is, Sonotorohead (23) and, A vibration control unit (25) connected to the sonotrode head (23) and configured to activate the ultrasonic vibration of the sonotrode head (23), Equipped with, The vibration control unit (25) is One or more piezoelectric converters (35) configured to generate ultrasonic vibrations are coupled to the sonotrode head (23), In order to determine and / or monitor the operating state of each of the one or more piezoelectric conversion devices (35), one or more temperature sensors (36) are configured to measure the temperature of the one or more piezoelectric conversion devices (35), Equipped with, The vibration control unit (25) further comprises at least a housing shell (41) having an internal space (42), Each piezoelectric conversion device (35) and each temperature sensor (36) is arranged within the internal space (42). Sealing device (20).

2. The one or more temperature sensors (36) are operably connected to and / or coupled to an analysis unit (40) configured to monitor and / or determine the operating state of the one or more piezoelectric conversion devices (35) according to the temperature measured by the one or more temperature sensors (36). The sealing device according to claim 1.

3. The one or more temperature sensors (36) are associated with each piezoelectric converter (35) to measure the temperature of each piezoelectric converter (35) in order to determine and / or monitor the operating state of each piezoelectric converter (35). The sealing device according to claim 1.

4. Each temperature sensor (36) is in contact with the respective piezoelectric conversion device (35). The sealing device according to claim 3.

5. Each of the piezoelectric conversion devices (35) is equipped with a metal connector (38) designed to establish an electrical connection with the generator of the sealing device (20), Each of the temperature sensors (36) contacts the metal connector (38) of the respective piezoelectric conversion device (35). The sealing device according to claim 3.

6. The metal connector (38) contains copper. The sealing device according to claim 5.

7. The vibration control unit (25) includes one or more electrical cables (39) configured to supply power to one or more piezoelectric conversion devices (35), The one or more electrical cables (39) are connected to the respective piezoelectric converters (35) via the first ends (39b) of the electrical cables (39). The one or more temperature sensors (36) are configured to measure the temperature of the one or more piezoelectric converters (35) by measuring the temperature of the first end (39b) of the one or more electrical cables (39). The sealing device according to claim 1.

8. The one or more temperature sensors (36) are located at the first end (39b) of each of the one or more electrical cables (39). The sealing device according to claim 7.

9. Each electrical cable (39) comprises an electrical wire and a protective sheath (39a) surrounding the electrical wire, and one or more temperature sensors (36) are positioned between the protective sheath (39a) and the electrical wire of each of the one or more electrical cables (39). The sealing device according to claim 7.

10. Each temperature sensor (36) is a thermistor. The sealing device according to claim 1.

11. Each of the temperature sensors (36) is either a negative temperature coefficient thermistor or a positive temperature coefficient thermistor. The sealing device according to claim 10.

12. The operating state of the one or more piezoelectric conversion devices (35) is the lifespan and / or aging degradation and / or operating characteristics of each of the one or more piezoelectric conversion devices (35). The sealing device according to claim 1.

13. A packaging machine (1) for packaging a pourable product into a package (2), comprising at least one sealing device (20) as described in claim 1.

14. A method for operating the sealing device (20) according to claim 1, a) The step of exciting ultrasonic vibrations of the sonotrode head (23) by the operation of one or more piezoelectric conversion devices (35), b) A step of measuring the temperature of one or more piezoelectric conversion devices (35), c) A step of determining the operating state of one or more piezoelectric conversion devices (35) based on the temperature obtained in step b), A method that includes at least the following.

15. During step b), the temperature of each piezoelectric conversion device (35) is measured by its respective temperature sensor (36). During step c), the operating state of each piezoelectric conversion device (35) is determined according to the respective temperature determined during step b). The method according to claim 14.

16. During step c), the remaining lifespan and / or degradation over time of one or more piezoelectric conversion devices (35) is estimated. The method according to claim 14.

17. d) further includes the step of planning maintenance based on the operating state of one or more piezoelectric conversion devices (35), The method according to claim 14.

18. A sealing device (20) for sealing a package (2) filled with a product that can be poured into a packaging machine (1), The sealing device (20) has at least one sonotrode (21), The aforementioned sonotrode is, Sonotorohead (23) and, A vibration control unit (25) connected to the sonotrode head (23) and configured to activate the ultrasonic vibration of the sonotrode head (23), Equipped with, The vibration control unit (25) is A first piezoelectric converter (35) and a second piezoelectric converter (35) are configured to generate ultrasonic vibrations coupled to the sonotrode head (23), A first temperature sensor (36) is configured to measure the temperature of the first piezoelectric converter (35) in order to determine and / or monitor the operating state of the first piezoelectric converter (35), A second temperature sensor (36) is configured to measure the temperature of the second piezoelectric converter (35) in order to determine and / or monitor the operating state of the second piezoelectric converter (35), Equipped with, The first piezoelectric converter (35) and the second piezoelectric converter (35) each comprise a plurality of piezoelectric elements (37) stacked on top of each other. Sealing device (20).

19. The sonotrode head (23) has a sealing surface (24) extending along the longitudinal axis (A), and the sealing surface (24) comprises a first portion (26) and a second portion (27) that are spaced apart from each other and arranged parallel to each other. The sonotrode head (23) further comprises a groove (28) interposed between the first portion (26) and the second portion (27), the groove (28) being designed to receive a portion of the blade when cutting the tube (4) laterally. The sealing device according to claim 18.

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