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

Abstract

A sealing device (20) for sealing packages (2) filled with pourable product within a packaging machine (1) is described. The sealing device (20) has at least one ultrasonic generator (21) comprising at least one ultrasonic generator head (23) and a vibration control unit (25) connected to the ultrasonic generator head (23) and configured to drive the ultrasonic generator head (23) into ultrasonic vibrations. The vibration control unit (25) comprises one or more piezoelectric transducer devices (35) configured to generate ultrasonic vibrations coupled into the ultrasonic generator head (23) and one or more temperature sensors (36) configured to measure a temperature of the one or more piezoelectric transducer devices (35) for determining and / or monitoring a respective operating state of the one or more piezoelectric transducer devices (35).

Description

Technical Field

[0001] This invention relates to a sealing device for sealing (particularly lateral sealing) packages (particularly composite packages) within a packaging machine for packaging pourable products (particularly pourable food).

[0002] Advantageously, the invention also relates to a packaging machine for packaging pourable products (especially pourable food) into packages (especially composite packages), and the packaging machine has at least one sealing device for sealing the packages.

[0003] Furthermore, the present invention also relates to a method for operating a sealing device within a packaging machine for packaging pourable products (especially pourable food products) into packages (especially composite packages). Background Technology

[0004] As is well known, many liquid or pourable foods, such as fruit juice, UHT (ultra-high temperature) milk, wine, ketchup, etc., are sold in packages (especially sealed packages) made of sterilized packaging materials.

[0005] A typical example is the parallelepiped-shaped packaging for pourable foods, called Tetra BrikAseptic (registered trademark), which is made by sealing and folding laminated strip packaging material. The packaging material has a multi-layered structure, including a cardboard box and / or paper base layer, with heat-sealable plastic material layers, such as polyethylene, covering both sides. For aseptic packaging of products intended for long-term storage, the packaging material also includes an oxygen barrier material, such as aluminum foil, which is stacked on top of a heat-sealable plastic material, and then sequentially covered with another heat-sealable plastic material to form the inner surface of the packaging that ultimately contacts the food.

[0006] This type of packaging is typically produced on fully automated packaging machines, where a roll of packaging material is fed through a sterilization unit to sterilize it during use. The sterilized roll is then held and advanced within an isolation chamber, where it is longitudinally folded and sealed to form a tube that advances further. The tube is then filled with a pourable product and, during its advancement, is laterally sealed and cut along equally spaced transverse cross-sections within the packaging forming unit of the packaging machine.

[0007] More specifically, the packaging forming apparatus includes multiple forming and sealing assemblies, each of which shapes the tube and laterally seals and cuts it during use to obtain individual packages.

[0008] Each molding and sealing assembly includes a corresponding sealing device for the transverse sealing tube, so as to obtain a corresponding transverse seal by locally compressing the tube and heating a corresponding portion of the heat-sealing plastic material layer. Heating can occur, for example, by a sealing device that generates ultrasonic vibrations.

[0009] The sealing device heated by ultrasonic vibration includes an ultrasonic generator configured to generate ultrasonic vibrations and an anvil designed to cooperate with the ultrasonic generator to locally compress the tube.

[0010] A typical ultrasonic generator includes an ultrasonic generator head having a sealed surface extending along a longitudinal axis and a vibration control unit connected to the ultrasonic generator head and configured to actuate the ultrasonic vibration of the ultrasonic generator head.

[0011] More specifically, the vibration control unit includes a housing and one or more piezoelectric transducers arranged within the housing and configured to generate ultrasonic vibrations coupled to an ultrasonic generator head.

[0012] It is known that piezoelectric transducers have a limited lifespan due to aging; therefore, the ultrasonic generator must be replaced entirely or at least the piezoelectric transducer must be replaced according to a pre-established maintenance protocol.

[0013] Despite the fact that known sealing devices operate with high quality and reliability, there is still a desire in the field to further improve known sealing devices.

[0014] In particular, it is desirable to operate the corresponding ultrasonic generator for as long as possible and avoid any unintended malfunctions. Summary of the Invention

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

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

[0017] In addition, 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 claimed in the claims directly or indirectly dependent on claim 1.

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

[0021] In addition, according to the present invention, the method according to claim 12 is also provided.

[0022] Preferred embodiments of the method are claimed in the claims directly or indirectly dependent on claim 12. Attached Figure Description

[0023] Non-limiting embodiments of the invention will be described by way of example with reference to the accompanying drawings, wherein:

[0024] Figure 1 This is a schematic diagram of a packaging machine having at least one sealing device according to the invention; some parts have been omitted for clarity.

[0025] Figure 2 yes Figure 1 A schematic diagram of the packaging machine, including portions of the sealing device according to the invention, with some parts omitted for clarity;

[0026] Figure 3 yes Figure 2 A side view of a portion of the sealing device, with some parts removed for clarity;

[0027] Figure 4 yes Figure 3 This is a magnified perspective view of a portion of the document; some parts have been removed for clarity.

[0028] Figure 5 According to one or more embodiments Figure 2 A side view of a portion of the sealing device, with some parts removed for clarity. Detailed Implementation

[0029] The number 1 generally refers to a packaging machine used for producing sealed packages of pourable products (especially pourable foods, such as (pasteurized) milk, juice, wine, ketchup, salt, sugar, etc.).

[0030] More specifically, the packaging machine 1 can be configured to produce composite packaging 2 from composite multilayer packaging materials.

[0031] More specifically, the packaging material may include at least one layer of fibrous material (e.g., paper or cardboard) and at least two layers of heat-sealable plastic material (e.g., polyethylene), with the fibrous material layer inserted between the heat-sealable material layers. One of the two heat-sealable plastic materials defines the inner surface of the body 2 that contacts the pourable product.

[0032] In addition, the packaging material may also include gas barrier and light barrier material layers, such as aluminum foil or ethylene vinyl alcohol (EVOH) film, particularly disposed between one of the heat-sealable plastic material layers and the fiber material layer. Preferably, the packaging material may also include another heat-sealable plastic material layer interposed between the gas barrier and light barrier material layer and the fiber material layer.

[0033] More specifically, the packaging material can be provided in the form of rolls 3.

[0034] Furthermore, the packaging machine 1 can be configured to produce packaging 2 by means of a roll 3 forming tube 4, a longitudinal sealing tube 4, a pourable product filling tube 4, and a transverse sealing and cutting tube 4.

[0035] A typical package 2 obtained by the packaging machine 1 includes a longitudinal seam portion 5 and a pair of corresponding first transverse sealing strips and corresponding second transverse sealing strips, specifically arranged on opposite sides of the package 2. In particular, the first transverse sealing strip may define a transverse top sealing strip, and the second transverse sealing strip may define a transverse bottom sealing strip.

[0036] Special Reference Figure 1 Packaging machine 1 may include: - Conveying device 7, which is used to advance the roll 3 along the roll advance path P (in a known manner) to In use, the roll material 3 is formed into a tube 4 at the forming station 8; -Isolation room 9, which has an internal environment, particularly an internal sterile environment containing sterile gases, and is separated from the (hostile) external environment; - Tube forming and sealing device 10, which is configured to be propelled by a roll within its internal environment during use. Material 3 forms tube 4 and longitudinally seals tube 4 within its internal environment; - Filling device 11, which is used to continuously fill tube 4 with pourable product; and - Packaging forming equipment 12, which is configured to form, laterally seal and laterally cut the forward tube 4 for forming the package 2 in use.

[0037] In addition, the packaging machine 1 may also include a disinfection unit configured to disinfect the advancing roll 3 in use at a disinfection station, particularly a disinfection station arranged upstream of the forming station 8 along the roll advance path P.

[0038] More specifically, the conveying device 7 can be configured to advance the tube 4 and any intermediate parts of the tube 4 along the tube advance path Q, particularly from the forming station 9 to the packaging forming unit 16. Specifically, any configuration of the roll 3 below the intermediate parts of the tube 4 refers to the process before obtaining the tube structure and after the folding of the roll 3 begins by the tube forming and sealing device 10. In other words, the intermediate parts of the tube 4 are the result of gradually folding the roll 3 to obtain the tube 4, particularly by overlapping the edges of the roll 3 with each other.

[0039] Preferably, the tube forming and sealing device 10 can be arranged such that the tube 4 can be vertically oriented.

[0040] More specifically, the tube forming and sealing device 10 may include at least two forming ring assemblies 16, particularly arranged within the isolation chamber 9, which are configured to cooperate with another roll 3 and gradually fold into the tube 4, particularly by overlapping the edges of the roll 3 with each other. Thus, in use, a seam portion 5 is formed in the tube 3.

[0041] Additionally, the tube forming and sealing device 10 may include a sealing head 17, particularly arranged within the isolation chamber 9 and configured to longitudinally seal the tube 4, particularly along the joint portion 5.

[0042] In addition, the tube forming and sealing device 10 may also include a pressurizing assembly configured to apply mechanical force to the joint portion 5 to ensure that the tube 4 is sealed along the joint portion 5.

[0043] Additionally, the filling device 11 may include a filling tube 18 configured to guide pourable product into the tube 4 during use. Specifically, the filling tube 18 may be at least partially placed inside the tube 4 during use to supply product into the tube 4.

[0044] Special Reference Figure 1 and Figure 2 The packaging forming device 12 may include: - Multiple molding and sealing components 19 (in) Figure 2 (Only a partial extent shown is required for understanding the invention), each molding and sealing assembly 19 is configured to at least mold (shape) tube 4, lateral sealing tube 4, and in particular also laterally cut tube 4; and - A conveying unit (not shown but known in itself) is used to advance the forming and sealing assembly 19.

[0045] Specifically, the packaging forming device 12 is configured to control the forming and sealing assembly 19 and the conveying unit to laterally seal and cut the tube 4 along equally spaced transverse cross sections.

[0046] More specifically, each molding and sealing assembly 19 may include: - A molded shell (not shown and known in itself) configured to at least partially define the shape of package 2; as well as - Sealing device 20, which is configured to at least laterally compress, particularly flatten and squeeze, and laterally seal tube 4, especially during the tube's movement along path Q and between two corresponding packages 2.

[0047] In addition, each forming and sealing assembly 19 may include a cutting device (not shown) for laterally cutting the tube 4.

[0048] Specifically, each sealing device 20 is configured to form a main sealing strip, and a corresponding cutting device is configured to laterally cut through the main sealing strip. Even more specifically, each main sealing strip combines a corresponding first lateral sealing strip of the front package 2 and a corresponding second lateral sealing strip of the subsequent package 2.

[0049] More specifically, each molded shell may include at least a first half-shell (not shown but known in itself) and a second half-shell (not shown but known in itself), which are configured to at least partially jointly define the shape of the package 2. Specifically, the first half-shell and the second half-shell are configured to contact the tube 4 from opposite sides of the tube 4.

[0050] 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 portions of the heat-sealing plastic material layer.

[0051] Furthermore, each sealing device 20 may include at least: - An ultrasonic generator 21 for generating ultrasonic vibrations, particularly for heating / melting heat-sealing plastics. The corresponding part of the material layer; and - Anvil 22, which is used in conjunction with the ultrasonic generator 21 tube 4 for compression, especially local flattening and squeezing.

[0052] More specifically, each cutting device includes at least one movable blade for laterally cutting tube 4.

[0053] Furthermore, each ultrasonic generator 21 is associated with a corresponding first half-shell, specifically defining a first operating portion of the corresponding molding and sealing assembly 19, and each anvil 22 is associated with a corresponding second half-shell, specifically defining a second operating portion of the corresponding molding and sealing assembly 19.

[0054] Furthermore, the corresponding blade of the corresponding cutting device is associated with either the corresponding ultrasonic generator 21 or the corresponding anvil 22, in certain cases associated with the corresponding anvil 22. In other words, each cutting device is associated either with a corresponding first operating part or a corresponding second operating part, which is shown as the corresponding second operating part in specific cases.

[0055] Furthermore, the transmission unit can be configured to cause the corresponding first operating part to advance along the first path and the corresponding second operating part to advance along the second path.

[0056] Furthermore, each first operating part and the corresponding second operating part can be configured to cooperate with each other to form package 2 as the respective operating parts of the first path and the second path advance.

[0057] For details, please refer to the following: Figure 3 and Figure 4 Each ultrasonic generator 21 includes at least: - Ultrasonic generator head 23, particularly having a sealing surface 24 extending along the longitudinal axis A; and - Vibration control unit 25, which is connected to ultrasonic generator head 23 and configured to actuate ultrasonic vibration of ultrasonic generator head 23.

[0058] More specifically, each sealing surface 24 may be designed as a contact tube 4 and establish an operational connection with a portion of the heat-sealed plastic material layer.

[0059] In addition, each sealing surface 24 may include a first portion 26 and a second portion 27 that are offset from each other and parallel to each other.

[0060] Furthermore, each ultrasonic generator head 23 may include a recess 28, specifically, the recess 28 being inserted between a corresponding first portion 26 and a corresponding second portion 27. Specifically, each recess 28 is designed to receive a portion of the corresponding blade during transverse cutting of the tube 4.

[0061] Special Reference Figures 2 to 4 Each vibration control unit 25 may include one or more piezoelectric transducer devices 35. Figure 3 and Figure 4 As shown in the diagram, it is configured to generate ultrasonic vibrations coupled to the corresponding ultrasonic generator head 23. In the specific case shown, the vibration control unit 25 includes three piezoelectric transducer devices 35; however, this number can vary depending on the format of the package 2; that is, depending on the form of the package 2, the extension of the sealing surface 24 can be larger or shorter; specifically, a shorter sealing surface 24 may require fewer piezoelectric transducer devices 35 than a larger sealing surface.

[0062] Additionally, each vibration control unit 25 may include one or more temperature sensors 36 configured to (directly or indirectly) measure the temperature of the piezoelectric transducer 35 for determining and / or controlling the corresponding operating state of the piezoelectric transducer 35.

[0063] Specifically, the applicant has observed that the temperature of each piezoelectric transducer device 35 indicates the operating characteristics of the piezoelectric transducer device 35 and / or the aging and / or remaining lifespan of the piezoelectric transducer device 35. For example, the applicant has found that each piezoelectric transducer device 35 degrades over time due to its operation, resulting in increased heat dissipation during use.

[0064] Preferably, the temperature sensor 36 is configured to continuously and / or in real time measure the temperature of the piezoelectric transducer 35. Specifically, this is to continuously and / or in real time determine and / or monitor the operating status of the piezoelectric transducer 35.

[0065] According to the specific example shown, at least one temperature sensor 36 is associated with each piezoelectric transducer device 35 to measure the corresponding temperature and to allow determination and / or monitoring of the operating status of the corresponding piezoelectric transducer device 35.

[0066] According to some possible embodiments, each temperature sensor 36 is connected to a corresponding piezoelectric transducer device 35 in order to (directly) measure the corresponding temperature.

[0067] Alternatively, each temperature sensor 36 can determine the corresponding temperature in a non-contact mode.

[0068] According to some possible alternative embodiments, the temperature of the piezoelectric transducer 35 can also be determined by the average temperature of the corresponding piezoelectric transducer device 35 of the corresponding sealing device 20.

[0069] More specifically, each temperature sensor 35 can be a thermistor; that is, the temperature determined by the temperature sensor 35 is generated by the change in resistance of the temperature sensor 36.

[0070] More specifically, each temperature sensor 35 can be a negative temperature coefficient (NTC) thermistor (i.e., the resistance decreases as the temperature increases) or a positive temperature coefficient (PTC) thermistor (i.e., the resistance increases as the temperature increases).

[0071] It should be noted that this type of temperature sensor 35 has an accuracy of 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 and PTC thermistors, is sufficient to determine and / or monitor the operating status of the piezoelectric transducer device 35. Therefore, by relying on thermistors, particularly NTC and PTC thermistors, a more economical solution can be obtained compared to other types of temperature sensors, although it is more expensive, yet still reliably determines the operating status of the piezoelectric transducer device 35.

[0072] Special Reference Figure 4 Each piezoelectric transducer device 35 may include a plurality of piezoelectric (ceramic) elements 37, which are stacked on top of each other. More specifically, each piezoelectric transducer device 35 may also include a plurality of conductive metal sheets, particularly formed together with the piezoelectric elements 37 in alternating stacks of piezoelectric elements 37 and conductive metal sheets. Preferably, a corresponding temperature sensor 36 may be configured to measure the temperature of the corresponding piezoelectric element 37.

[0073] Additionally, each sealing device 20, particularly the corresponding vibration control unit 25, may include one or more generators (not shown and known per se) operatively connected to the piezoelectric transducer 35, particularly the piezoelectric element 37, to actuate and control the ultrasonic vibration of the piezoelectric transducer 35.

[0074] Furthermore, each piezoelectric transducer device 35 may include at least one metal connector 38, specifically connected to a corresponding conductive metal plate, designed to establish an electrical connection with at least one generator. Specifically, each vibration control unit 25 includes one or more cables 39, each cable 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.

[0075] Advantageously, each temperature sensor 36 contacts a corresponding metal connector 38 of the corresponding piezoelectric transducer device 35 (in order to establish contact with the corresponding piezoelectric transducer device 35).

[0076] Preferably, each metal connector 38 may comprise copper, and in particular, be composed of copper. Because copper has very good thermal properties, this ensures that the temperature determined by the corresponding temperature sensor 36 corresponds to one of the corresponding piezoelectric transducer devices 35, and in particular, the corresponding piezoelectric element 37.

[0077] According to some possible non-limiting embodiments, the packaging machine 1, particularly the packaging forming device 12, may include at least one analysis unit 40, which is operatively coupled to a temperature sensor 36 and configured to monitor and / or determine the operating status of the piezoelectric transducer device 35 based on the temperature determined by the temperature sensor 36.

[0078] According to some possible non-limiting embodiments, each sealing device 20 includes a corresponding portion of an analysis unit 40 operatively connected to a corresponding temperature sensor 36 to measure the temperature of the corresponding piezoelectric transducer device 35. In particular, the corresponding portion of the analysis unit 40 is configured to monitor and / or determine the operating status of the piezoelectric transducer device 35 based on the temperature determined by the temperature sensor 36.

[0079] Furthermore, analysis unit 40 and / or portions thereof can be configured to plan maintenance activities based on the operating status of the piezoelectric transducer device 35. Specifically, analysis unit 40 and / or portions thereof can be configured to plan maintenance activities based on the remaining lifespan and / or aging of the piezoelectric transducer device 35. In this way, the use of the piezoelectric transducer device 35 can be optimized.

[0080] For example, each analysis unit 40 and / or a portion of analysis unit 40 can signal the remaining lifespan of the piezoelectric transducer device 35 and signal that maintenance should be performed within a specific time frame.

[0081] Furthermore, the analysis unit 40 and / or portions thereof can be configured to assess the likelihood of abnormal operating conditions based on the temperature measured by the temperature sensor 36. Additionally, the analysis unit 40 and / or portions thereof can be configured to warn of the risk of abnormal operating conditions, for example, through prompts and / or audio messages and / or similar electronic messages on the (packaging machine 1) human-machine interface.

[0082] Additionally, each vibration control unit 25 may also include at least one housing 41 having an internal space 42 (e.g., Figure 3 (As shown; transparency is for illustrative purposes). Specifically, the housing 41 contacts the corresponding ultrasonic generator head 23 to seal the internal space 42 and isolate it from the external space.

[0083] Preferably, each piezoelectric transducer device 35 and each temperature sensor 36 are arranged within a corresponding internal space 42. Specifically, the corresponding generator can also be arranged within a corresponding internal space 42.

[0084] Furthermore, each vibration control unit 25 may include a coupling portion 43 that contacts the corresponding ultrasonic generator head 23 along a corresponding contact surface. Additionally, each piezoelectric transducer device 35 may be placed within a corresponding seat 44 of the corresponding coupling portion 43 (see, in particular). Figure 3 It also contacts the coupling part 43 so as to allow the generated ultrasonic vibrations to be transmitted to the corresponding ultrasonic generator head 23.

[0085] In use, packaging machine 1 produces packaging 2 filled with pourable products.

[0086] More specifically, the conveying device 7 advances the roll 3 along the roll advance path P to the forming station 8. The tube forming and sealing device 10 forms a tube 4 from the advancing roll 3 and seals the tube 4 longitudinally. In addition, the filling device 11 fills the tube 4 with a tiltable product, and the packaging forming unit 12 forms, seals laterally, and cuts the tube 4 laterally to obtain the package 2.

[0087] More specifically, during the operation of the packaging forming unit 12, the forming and sealing assembly 19 forms, laterally seals, and particularly laterally cuts the tube 4 to obtain the corresponding filled package 2.

[0088] Thus, molding is achieved through the cooperation of the corresponding molded shells, particularly the corresponding first half-shell and second half-shell.

[0089] In addition, lateral sealing occurs through the corresponding sealing device 20.

[0090] In addition, transverse cutting is performed using a corresponding cutting device.

[0091] More specifically, the operation of each sealing device 20 includes at least the following main steps: - Compression (especially when flat and squeezed) is achieved through the cooperation of the corresponding anvil 22 and the corresponding ultrasonic generator 21. (Pressure) pipe 4; and -Ultrasonic vibrations are generated by ultrasonic generator 21 to heat parts of the heat-sealed plastic material layer.

[0092] More specifically, the operation of each sealing device 20 also includes the following steps: a) The ultrasonic vibration of the corresponding ultrasonic generator head 23 is excited by the operation of the vibration control unit 25 and the corresponding piezoelectric transducer 35; b) Measure the temperature of the corresponding piezoelectric transducer 35; and c) Based on the temperature obtained in step b), the operating state of the corresponding piezoelectric transducer 35 is determined specifically by analysis unit 40 and / or the corresponding part of analysis unit 40.

[0093] More specifically, during each step b), the temperature of each piezoelectric transducer device 35 can be measured by a corresponding temperature sensor 36, and during step c), the operating state of each piezoelectric transducer device 35 can be determined based on the temperature determined during the corresponding step b).

[0094] Preferably, steps b) and c) can be performed consecutively.

[0095] In addition, the operation of each sealing device 20 may also include a transmission step, during which the measurement results of the temperature sensor 36 may be transmitted to the analysis unit 40 and / or a corresponding part of the analysis unit 40.

[0096] More specifically, during step c), the remaining lifespan and / or aging of the piezoelectric transducer 35 can be estimated.

[0097] Additionally, the operation of each sealing device 20 may include a d) planning step, during which maintenance is planned based on the operating status of one or more piezoelectric transducers 35. In particular, in this way, maintenance can be planned based on the effective remaining lifespan and / or aging of the piezoelectric transducers 35.

[0098] In addition, the operation of each sealing device 20 may also include an alarm step during which a risk signal of abnormal operating conditions may be issued, for example, through prompts and / or audio messages and / or similar electronic messages on a human-machine interface.

[0099] The advantages of the sealing device 20 and / or packaging machine and / or method according to the invention will become clear from the foregoing description.

[0100] Specifically, by providing a temperature sensor 36, the temperature of the piezoelectric transducer device 35 can be measured, and the operating status of the piezoelectric transducer device 35 can be monitored and / or determined based on the measured temperature. In this way, it is possible to monitor whether the piezoelectric transducer device 35 is operating correctly and / or determine the remaining lifespan and / or aging of the piezoelectric transducer. This again allows for determining whether to perform maintenance activities based on the actual aging of the piezoelectric transducer device 35 rather than according to a predetermined schedule. This also ensures the avoidance of unexpected failures and unnecessary maintenance activities.

[0101] A further advantage is that real-time data on the operating status of the piezoelectric transducer device 35 can be obtained, thereby allowing for rapid action and further mitigating the risk of operational anomalies that could impede the proper operation of the sealing device 20.

[0102] Another advantage is that the temperature sensor 36 is connected to the corresponding metal connector 38, which is used to connect the piezoelectric transducer device 35, and in particular the piezoelectric element 37, to the corresponding generator via the corresponding cable 39. In this way, space requirements can be optimized.

[0103] Another advantage is the use of thermistors as temperature sensors.36 This is relatively inexpensive and easy to install. Similarly, their accuracy is sufficient for specific applications.

[0104] Obviously, changes can be made to the sealing device 20 and / or packaging machine 1 and / or method described herein without departing from the scope of protection defined by the appended claims.

[0105] Therefore, one or more embodiments may 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 in Figure 5 As shown in the image. It should be understood that, with reference to... Figure 5 The reference numerals used are the same as those used in the other figures previously referred to, have the same meaning, and refer to the same features.

[0106] The sealing device 20 has at least one ultrasonic generator 21, which includes at least an ultrasonic generator head 23 and a vibration control unit 25 connected to the ultrasonic generator head 23 and configured to actuate the ultrasonic vibration of the ultrasonic generator head 23.

[0107] like Figure 5 As shown, the vibration control unit 25 may include: - One or more piezoelectric transducer devices 35, which are configured to generate ultrasonic vibrations coupled to an ultrasonic generator head 23; One or more cables 39, configured to supply power to one or more corresponding piezoelectric transducer devices 35 (e.g., providing electrical connection and power to one or more corresponding piezoelectric transducer devices 35), the one or more cables 39 being connected via a first end 39b to the corresponding one or more piezoelectric transducer devices 35. Electric transducer device 35; and - One or more temperature sensors 36 are configured to measure (e.g., directly or indirectly) the temperature of one or more piezoelectric transducer devices 35 to determine and / or monitor the corresponding operating status of one or more piezoelectric transducer devices 35 by measuring the temperature at the first end 39b of one or more cables 39.

[0108] In other words, the temperature sensor 36 can be configured to measure the temperature at the first end 39b of the cable 39, which indicates the temperature of the corresponding piezoelectric transducer device 35. This allows for reliable, accurate, and robust measurement of the temperature of the piezoelectric transducer device 35 without direct contact. Specifically, the temperature at the first end of the cable 39 closest to the piezoelectric transducer device 35 is extremely similar to the temperature of the piezoelectric transducer device 35, and therefore, a precise measurement of the temperature of the piezoelectric transducer device 35 can be obtained. Figure 5 The embodiments depicted may be advantageous because they can be particularly robust to vibrations of the piezoelectric transducer device 35.

[0109] One or more temperature sensors 36 may be located at the first end 39b of one or more corresponding cables 39.

[0110] Each cable 39 may include a wire and a protective sheath 39a surrounding the wire. For example... Figure 5 As shown, one or more temperature sensors 36 may be positioned, for example, at the first end 39b, between the protective sleeve 39a and the wires of one or more corresponding cables 39.

[0111] For example, one or more temperature sensors 36 may be completely or partially covered by the protective sheath 39a of the corresponding one or more cables 39. For example, the temperature sensor 36 may be pressed onto and / or kept in contact with the wire by the sheath 39a. For example, the cable 360 ​​supplying power to the temperature sensor 36 may be similarly positioned between the protective sheath 39a and the wire of the corresponding one or more cables 39, for example, completely or partially covered by the protective sheath 39a.

[0112] More specifically, each cable 39 can be connected to at least one generator and at a first end 39b to at least one metal connector 38 of the piezoelectric transducer device 35 to establish an electrical connection between the generator and the metal connector. A temperature sensor 36 can be configured to measure the temperature at the first end 39b, which indicates the temperature at both the piezoelectric transducer device 35 and the metal connector 38. Thus, instead of measuring the temperature of the metal connector 38, the temperature at the first end of the cable 39 can be measured, still obtaining a reliable, robust, and accurate measurement of the temperature of the piezoelectric transducer device 35.

[0113] Therefore, the temperature measurement obtained by the temperature sensor 36 at the first end 39b of the cable 39 can indicate the temperature of the corresponding one or more piezoelectric transducer devices 35. The analysis unit 40 can be configured as follows: - Receive one or more temperatures measured at the first end 39b of one or more cables 39, and - Calculate the temperature of one or more piezoelectric transducer devices 35 based on the measured temperature and a preferred correction factor (e.g., a linear correction factor).

[0114] To avoid any doubt, each piezoelectric transducer device 35 has a corresponding cable 39 for powering it. Furthermore, each temperature sensor 26 can be positioned at the end 39b of the corresponding cable 39. That is, each temperature sensor 36 is associated (e.g., in contact with or close proximity to) a single cable 39 and a single piezoelectric transducer device 35.

Claims

1. A sealing device (20) for sealing a package (2) filled with a pourable product inside a packaging machine (1); The sealing device (20) has at least one ultrasonic generator (21), the ultrasonic generator comprising at least: - Ultrasonic generator head (23); and - A vibration control unit (25) is connected to the ultrasonic generator head (23) and configured to drive ultrasonic vibrations of the ultrasonic generator head (23); The vibration control unit (25) includes: - One or more piezoelectric transducer devices (35) configured to generate ultrasonic vibrations coupled to the ultrasonic generator head (23); and - One or more temperature sensors (36) configured to measure the temperature of the one or more piezoelectric transducer devices (35) for determining and / or monitoring the corresponding operating status of the one or more piezoelectric transducer devices (35); The vibration control unit (25) further includes at least one housing (41) having an internal space (42); Each piezoelectric transducer device (35) and each temperature sensor (36) are arranged within the internal space (42).

2. The sealing device according to claim 1, wherein, The one or more temperature sensors (36) are operatively coupled to and / or coupled to an analysis unit (40) configured to monitor and / or determine the operating status of the one or more piezoelectric transducer devices (35) that depend on the temperature measured by the one or more temperature sensors (36).

3. The sealing device according to claim 1 or 2, wherein, At least one temperature sensor (36) is associated with each piezoelectric transducer device (35) to measure the temperature of the corresponding piezoelectric transducer device (35) for determining and / or monitoring the operating status of the corresponding piezoelectric transducer device (35).

4. The sealing device according to claim 3, wherein each temperature sensor (36) is in contact with the corresponding piezoelectric transducer device (35).

5. The sealing device according to claim 3, wherein each piezoelectric transducer device (35) includes a metal connector (38) designed to establish an electrical connection with the generator of the sealing device (20); Each temperature sensor (36) is in contact with the metal connector (38) of the corresponding piezoelectric transducer device (35).

6. The sealing device according to claim 5, wherein, The metal connector (38) comprises copper.

7. The sealing device according to claim 1 or 2, wherein: The vibration control unit (25) includes one or more cables (39) configured to supply power to the corresponding one or more piezoelectric transducer devices (35), the one or more cables (39) being connected to the corresponding one or more piezoelectric transducer devices (35) via a first end (39b) of the cable (39), and - The one or more temperature sensors (36) are configured to measure the temperature of the one or more piezoelectric transducer devices (35) by measuring the temperature at the first end (39b) of the one or more cables (39).

8. The sealing device according to claim 7, wherein, The one or more temperature sensors (36) are positioned at the first end (39b) of the respective one or more cables (39).

9. The sealing device according to claim 7, wherein each cable (39) includes a wire and a protective sleeve (39a) surrounding the wire, and wherein one or more temperature sensors (36) are positioned between the protective sleeve (39a) and the wire of the respective one or more cables (39).

10. The sealing device according to any one of claims 1, 2, 4, 5, 6, 8 or 9, wherein each temperature sensor (36) is a thermistor.

11. The sealing device according to claim 10, wherein each temperature sensor (36) is a negative temperature coefficient thermistor or a positive temperature coefficient thermistor.

12. The sealing device according to any one of claims 1, 2, 4, 5, 6, 8, 9, or 11, wherein, The operating state of the one or more piezoelectric transducer devices (35) is the corresponding lifespan and / or the corresponding aging and / or operating characteristics of the one or more piezoelectric transducer devices (35).

13. A packaging machine (1) for packaging a pourable product into a package (2), said packaging machine (1) comprising at least one sealing device (20) according to any one of claims 1 to 12.

14. A method of operating the sealing device (20) according to any one of claims 1 to 12, the method comprising at least the following steps: a) To excite ultrasonic vibrations in the ultrasonic generator head (23) by operating the one or more piezoelectric transducer devices (35); b) Measure the temperature of the one or more piezoelectric transducer devices (35); and c) Determine the operating status of the one or more piezoelectric transducer devices (35) based on the temperature obtained in step b).

15. The method according to claim 14, wherein, During step b), the temperature of each piezoelectric transducer device (35) is measured by a corresponding temperature sensor (36), and during step c), the operating state of each piezoelectric transducer device (35) is determined based on the corresponding temperature determined during step b).

16. The method according to claim 14 or 15, wherein, During step c), the remaining lifespan and / or aging of the one or more piezoelectric transducer devices (35) are estimated.

17. The method according to claim 14 or 15, further comprising a d) planning step, during which maintenance is planned based on the operating status of the one or more piezoelectric transducer devices (35).

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