Sterilization device, packaging machine having sterilization device, and sterilization method

Abstract

A sterilization apparatus (9) for sterilizing a web (4) of packaging material advancing along a web advance path (P) is described. The sterilization apparatus (9) comprises:-first sterilization means (10) configured to sterilize at least a first face (5) of a web (4) traveling through said first sterilization means (10); a second sterilization device (7); -a monitoring device (8) configured to monitor the operation of the first sterilization device (10); -a movement sensor (11) configured to monitor the advancement of the web (4) along the advancement path (P); and-a control unit (12) connected to the monitoring device (8) and to the movement sensor (11), the control unit (12) being configured to, upon detection of an abnormal operation of the first sterilization device (10):-interrupt advancement of the web (4); -identifying a travel distance (D) of the web (4) between the detection of the anomaly and the interruption of the travel; and-sterilizing at least a portion (P1, P2, P3) of the web (4) by means of a second sterilization device (7), said portion (P1, P2, P3) of said web being related to said travel distance (D).

Description

Technical Field

[0001] The present invention relates to an apparatus for sterilizing a web of packaging material, in particular a web of packaging material for the production of sealed packages for pourable products, especially pourable foods.

[0002] The present invention also relates to a packaging machine for producing sealed packages for pourable products, especially pourable foods, the packaging machine having a sterilization apparatus.

[0003] The present invention also relates to a method for sterilizing a web of packaging material, in particular a web of packaging material for the production of sealed packages for pourable products, especially pourable foods. Background Art

[0004] As is well known, many liquid or pourable foods, such as fruit juices, UHT (ultra-high temperature) milk, wines, tomato ketchup, etc., are sold in packages made of aseptic packaging materials.

[0005] A typical example is the parallelepiped package for liquid or pourable foods, called Tetra Brik Aseptic (registered trademark), which is made of a laminated strip of packaging material that is sealed and folded. The packaging material has a multi-layer structure, including a base layer (e.g., paper) that is covered on both sides with heat-sealable plastic layers (e.g., polyethylene). For aseptic packaging for long-term storage of products (e.g., UHT milk), the packaging material also includes a layer of oxygen-barrier material (oxygen-barrier layer), such as aluminum foil, which is superimposed on the heat-sealable plastic material layer and then covered with another heat-sealable plastic material to form the final food-contact inner surface of the package.

[0006] Such packages are typically produced by a fully automatic packaging machine that advances a web of packaging material from a magazine unit through a sterilization apparatus to sterilize the web of packaging material and then into an isolation chamber (a closed aseptic environment), where the sterilized web of packaging material is stored and advanced. As the web of packaging material travels through the isolation chamber, the web of packaging material is longitudinally folded and sealed to form a tube having a longitudinal seam portion, and the tube is further conveyed along the vertical travel direction.

[0007] To complete the forming operation, a sterilized or sterilized-treated pourable product, especially a pourable food, is loaded into the tube, and while advancing along the vertical forward direction, a transverse seal is made in a packaging forming unit of the packaging machine, and then cutting is performed along equally spaced cross-sections.

[0008] In this way, pillow-shaped packages are obtained in the packaging machine, each pillow-shaped package having a longitudinal seal band, a top transverse seal band, and a bottom transverse seal band.

[0009] In recent years, there have emerged some sterilization devices configured to sterilize a web of packaging material by applying physical radiation (especially electromagnetic radiation, more especially electron beam radiation). As an alternative, solutions for sterilization devices using hydrogen peroxide are known, where the web of packaging material is sterilized by introducing it into a hydrogen peroxide bath.

[0010] Although the known sterilization devices and the corresponding packaging machines have achieved good results, there is still a need to improve the performance of the sterilization devices.

[0011] There is a need to efficiently and promptly handle abnormal situations during the operation of the sterilization device, such as abnormal peroxide bath temperature during hydrogen peroxide sterilization, abnormal ultraviolet lamp radiation, and / or arc events during sterilization with an electron beam.

[0012] These abnormalities can cause a temporary interruption in production, which may last for several hours in some cases, resulting in economic losses and increasing the time-consuming for machine operators. Therefore, there is a need to provide solutions that help minimize machine downtime. In addition, there is a need to minimize downtime while improving sterilization performance.

[0013] For example, when an arc occurs in the electron beam emitter, the operation of the packaging machine must be interrupted. The operator then manually cuts and removes the lower part of the packaging material, connects a cleaning tube for cleaning the filling device, cleans the sterilization device, and repositions the packaging material to the correct position. Then, further sterilization is carried out before resuming the normal operation of the packaging machine. Such operations are time-consuming and the downtime can be up to several hours. Summary of the Invention

[0014] Therefore, an object of the present invention is to provide a sterilization device in order to overcome at least one of the above disadvantages in a simple and low-cost manner.

[0015] Specifically, an object of the present invention is to provide a sterilization device capable of quickly and efficiently reacting to abnormal operations.

[0016] Another object of the present invention is to provide a packaging machine capable of overcoming at least one of the above disadvantages in a simple and low-cost manner. Another object of the present invention is to provide a sterilization method capable of overcoming at least one of the above disadvantages in a simple and low-cost manner.

[0017] According to the present invention, there is provided a sterilization device as described in claim 1.

[0018] According to the present invention, there is also provided a packaging machine according to claim 12.

[0019] According to the present invention, there is also provided a sterilization method according to claim 15.

[0020] The preferred embodiments are described in the dependent claims. Description of the Drawings

[0021] Hereinafter, non - limiting embodiments of the present invention will be described by way of example in conjunction with the drawings, wherein:

[0022] Figure 1 is a schematic view of a packaging machine having a sterilization device according to one or more embodiments. For clarity, some components have been removed from the figure;

[0023] Figure 2 is a schematic view of a sterilization device according to one or more embodiments. For clarity, some components have been removed from the figure; and

[0024] Figure 3 and Figure 4 are schematic views of the sterilization device 9 when an abnormality is detected and after the advancement of the web is interrupted, respectively. Detailed Description of the Invention

[0025] The numeral 1 denotes an overall packaging machine for producing sealed packages 2 of pourable products (in particular pourable foods such as pasteurized milk, fruit juices, wines, tomato ketchup, etc.) from a tube 3 formed from a web of packaging material 4. Specifically, in use, the tube 3 extends along a longitudinal axis, specifically having a vertical direction.

[0026] The web 4 comprises at least one layer of fibrous material (in particular paper), which is covered on both sides with layers of heat - sealable plastic material, such as polyethylene.

[0027] Preferably, the web 4 further comprises a gas - and light - barrier material layer, such as an aluminum foil or an ethylene - vinyl alcohol (EVOH) film, and at least a first and a second layer of heat - sealable plastic material. The gas - and light - barrier material layer is superimposed on the first layer of heat - sealable plastic material and is in turn covered by the second layer of heat - sealable plastic material. The second layer of heat - sealable plastic material forms the final inner surface of the package 2 that comes into contact with the filled pourable food.

[0028] More specifically, the web 4 comprises a first face or surface 5 and a second face or surface 6. Specifically, the first (front) surface 5 is the face of the web 4 that forms the final inner surface of the formed package 2 that comes into contact with the filled pourable food.

[0029] Typical packages 2 obtained by the packaging machine 1 include a longitudinal seam portion and a pair of transverse seal bands, specifically a transverse top seal band and a transverse bottom seal band.

[0030] With particular reference to Figure 1 , the packaging machine 1 is configured to advance the web 4 along a web advancement path P to sterilize the web 4 during its travel along the path P, to form the tube 3 from the web 4, to fill the tube 3, and to form individual packages 2 from the filled tube 3.

[0031] Preferably, the packaging machine 1 comprises: - a sterilization device 9, which comprises a first sterilization means 10 configured to sterilize at least a first (front) surface 5 of the web 4, and preferably also a second (front) surface 6 of the web 4; - an isolation chamber 14, which separates an internal environment 15 (in particular an internal sterile environment) from an external environment 16; - a tube forming device 17, which is at least partly (preferably completely) arranged within the isolation chamber 14 and configured to form a tube 3 from the web 4 which advances during use and has been sterilized; - a sealing device 19, which is at least partly arranged within the isolation chamber 14 and is configured to longitudinally seal the tube 3 formed by the tube forming device 17, thereby forming a longitudinal seam portion of the tube 3; - a filling unit 20, which is configured to fill the tube 3 with a fillable product (in particular a fillable food product); - a packaging forming unit 21, which is configured to at least form and transversely seal the tube 3, in particular the tube 3 advancing during use, to form a package 2; and - a plurality of conveyors, which are configured to advance the web 4 along a path P in a known manner and to advance the tube 3 along a tube advance path Q.

[0032] Specifically, the sterilization device 9 can receive the web 4 of packaging material from a main station (not visible in the figure).

[0033] For example, the plurality of conveyors can be configured to advance the web 4 of packaging material from the main station to the sterilization device 9 and / or from the sterilization device 9 to the tube forming device 17. For example, the plurality of conveyors can be configured to advance the tube 3 from the tube forming device 17 to the sealing device 19 and / or from the sealing device 19 to the filling unit 20 and / or from the filling unit 20 to the packaging forming unit 21.

[0034] Preferably, the plurality of conveyors are adapted to advance the tube 3 and any intermediates thereof along the path Q in a known manner, in particular from the tube forming device 17 towards the packaging forming unit 21 and at least partly through the packaging forming unit 21.

[0035] In one or more embodiments, the plurality of conveyors comprise a first conveyor 22, which is located (immediately) upstream of the sterilization device 9. Specifically, the first conveyor 22 can be positioned upstream of the entrance 90 of the sterilization device 9.

[0036] Preferably, the packaging machine 1 further comprises a pressure control device, which is configured to control the pressure in at least the isolation chamber 14 and at least part of the sterilization device 9 .

[0037] The sterilizing device 9 may be arranged upstream of the tube forming station 17 , relative to the coil advancement path P.

[0038] The sterilization device 9 may include an outlet 92. The outlet 92 may be located downstream relative to the first sterilization device 10 along the web advancement path P. The sterilized web 4 may be advanced toward the isolation chamber 14 through the outlet 92.

[0039] The isolation chamber 14 may comprise an inlet 140 , wherein the inlet 140 of the isolation chamber 14 may be connected to the outlet 92 of the sterilization device 9 .

[0040] The isolation chamber 14 may comprise an outlet 142 , wherein the tube 3 filled with the pourable product may leave the isolation chamber 14 from the outlet 142 .

[0041] The package forming unit 21 may be arranged along the path Q downstream of the isolation chamber 14 and the tube forming device 17 .

[0042] In one or more embodiments, Figure 3 and Figure 4 As shown, the sterilization device 9 includes: a first sterilization device 10, which is configured to sterilize the web 4 passing through the first sterilization device 10 to The first (surface) surface 5 is sterilized, and preferably the second (surface) surface 6 is also sterilized; - a second sterilizing device 7; - a monitoring device 8 configured to monitor the operation of the first sterilization device 10; a movement sensor 11 configured to monitor the progress of the web 4 along the advancement path P; and a control unit 12 connected to the monitoring device 8 and the movement sensor 11, wherein the control unit 12 is configured to, if an abnormal operation of the first sterilization device 10 is detected (e.g. a deviation from standard operation, such as an arc event), then: - interrupting the advancement of the coil 4; - identifying the distance D travelled by the web 4 between detection of the anomaly and interruption of advancement; and - sterilizing at least a portion P1 , P2 , P3 of the web 4 , which portion P1 , P2 , P3 is related to (eg substantially corresponds to) the travel distance D, using a second sterilizing device 7 .

[0043] The first sterilization device 10 may include an irradiation device configured to sterilize at least a first side 5 (and optionally a second side 6) of the advancing web 4 by directing sterilizing radiation onto at least the first side 5 (preferably also the second side 6).

[0044] Such a typical sterilization device includes an irradiation device which typically has a pair of electron beam emitters spaced apart from each other. The advancing channel through which the web 4 of packaging material travels during use is located between the electron beam emitters. Each electron beam emitter is configured to direct a respective electron beam onto a respective surface of the web of packaging material traveling through the advancing channel.

[0045] One disadvantage of this type of sterilization device 10 is that arc events may occur. During operation of the electron beam emitters, a discharge, i.e. an arc, may occur which can change the irradiation dose towards side 5 and / or side 6. That is to say, anomalies may include arc events. The control unit 12 may be configured to detect whether there is a change in the irradiation dose directed onto the first side 5 (and optionally the second side 6) of the web 4.

[0046] In the drawings, the first sterilization device 10 is depicted as an irradiation device as described above, but it will be understood that different types of first sterilization devices 10 may also be employed, such as a hydrogen peroxide bath. In this case, anomalies may include, for example, a change in the temperature of the hydrogen peroxide bath.

[0047] When an anomaly occurs in the operation of the first sterilization device 10, the control unit 12 may be configured to interrupt the operation of the packaging machine 1. Specifically, the control unit 12 may interrupt the operation of the first sterilization device 10, the tube forming device 17, the sealing device 19, the filling unit 20, the packaging forming unit 21 and / or the plurality of conveyors, preferably simultaneously.

[0048] According to one or more embodiments, the travel distance D is less than the distance D1 between the first sterilization device 10 and the outlet 92. That is to say, the travel distance D may be less than the travel distance D1 of the web 4 between the first sterilization device 10 and the outlet 92 during normal operation.

[0049] For example, portions P1, P2, P3 associated with (e.g., substantially corresponding to) the travel distance D may include the portion of the web 4 that passes (e.g., through) the first sterilization device 10 between detection of the anomaly and interruption of travel. For example, portions P1, P2, P3 may include a first portion P1 - P2 of the web 4 that exits the first sterilization device 10 between detection of the anomaly and interruption of travel, and a second portion P2 - P3 of the web 4 that is present within (e.g., in) the first sterilization device 10 when the travel of the web is interrupted.

[0050] Thus, the step of sterilizing at least portions P1, P2, P3 related to the travel distance D may include: at the first sterilization device 10, during an interruption of the web advancement, sterilizing at least a first portion P1 - P2 substantially corresponding to the distance D, and / or sterilizing a second portion P2 - P3.

[0051] Advantageously, the advancement of the web 4 can be interrupted before the first portion P1 - P2 of the web 4 reaches the outlet 92 of the sterilization device 9. In this way, the first portion P1 - P2 does not enter the isolation chamber 14.

[0052] Therefore, advantageously, the control unit 12 can be configured to (accurately and efficiently) identify the portions P1, P2, P3 passing through the device 10 when detecting that the first sterilization device 10 deviates from its normal operation. In this way, the portions P1, P2, P3 of the web 4 of packaging material that may be affected by the anomaly can be (accurately and precisely) identified.

[0053] For example, the movement sensor 11 can transmit a first sensor signal, such as indicating the speed and / or position and / or distance of travel of the web 4 of packaging material.

[0054] Advantageously, the web 4 of packaging material and the tube 3 present in the isolation chamber 14 and the sterilization device 9 when an anomaly is detected can be present in (i.e., remain in) the packaging machine 1 before, during, and after sterilization by the second sterilization device 7.

[0055] Advantageously, due to the identification of the travel distance D and / or the affected portions P1, P2, P3, the downtime due to such anomalies can be significantly reduced. The subsequent sterilization can be limited to the affected area and, optionally, to adjacent areas.

[0056] Figure 3 Depicts the state of the sterilization device 9 according to one or more embodiments in case of an anomaly.

[0057] The control unit 12 can be configured to receive a second sensor signal from the monitoring device 8, such as indicating a sterilization signal of the web 4 of packaging material.

[0058] The control unit 12 can be configured to detect an anomaly when the second sensor signal reaches (and optionally exceeds) a predetermined threshold. For example, if the monitoring device includes an irradiation sensor, the second sensor signal can indicate the radiation dose emitted by the first sterilization device 10. The control unit 12 can be configured to detect an anomaly if the emitted radiation dose reaches (e.g., is below) a threshold (e.g., a lower radiation dose value).

[0059] Preferably, the control unit 12 may be configured to detect an anomaly when the second sensor signal reaches (or exceeds) a predetermined threshold for a predetermined period of time. The predetermined period of time may be between 50 milliseconds and 120 milliseconds, preferably between 70 milliseconds and 110 milliseconds, more preferably between 80 milliseconds and 100 milliseconds. The predetermined period of time may depend on the traveling speed of the packaging material web 4. For example, the predetermined period of time may be inversely proportional to the traveling speed, i.e., if the traveling speed decreases, the predetermined period of time may increase.

[0060] More preferably, the control unit 12 may be configured to detect an anomaly when the second sensor signal continuously reaches (or exceeds) a predetermined threshold within a predetermined period of time. That is, the second sensor signal reaches (or exceeds) the threshold throughout the predetermined period of time. Advantageously, the predetermined period of time may help to detect a true anomaly and filter out false anomalies, such as fluctuations in the sensor signal due to electrical interference.

[0061] The control unit 12 may be configured to start identifying (e.g., calculating) the distance D at the start of the predetermined period of time. The control unit 12 may be configured to interrupt the advancement of the web 4 at the end of the predetermined period of time.

[0062] Figure 4 Depicts the state of the sterilization device 9 according to one or more embodiments during an interruption in the operation of the sterilization device 9 (and the packaging machine 1). The first part P1 - P2 may (substantially) correspond to the traveling distance D. The second part P2 - P3 may include the part present at the first sterilization device 10 (e.g., within the first sterilization device 10) during the interruption of the advancement.

[0063] In one or more embodiments, the second sterilization device 7 may include a hydrogen peroxide injection tank 70 configured to spray vaporized hydrogen peroxide at least at the portions P1, P2, P3 of the web 4 that are related to the traveling distance D between the detection of the anomaly and the interruption.

[0064] As shown, the injection tank 70 may be connected to a pipe 72 configured to convey vaporized hydrogen peroxide at the first sterilization device 10. Specifically, the pipe 72 is configured to convey vaporized hydrogen peroxide at its outlet relative to the advancement path P of the web.

[0065] The injection tank 70 may be configured to sterilize the P1 - P3 portion of the web 4 using the pipe 72. The air (e.g., air flow) coming out of the pipe 72 may pass through the first sterilization device 10 and be collected through a pipe 74 (only partially shown). Thus, such air may flow along the advancement path P of the web in a direction opposite to the advancement direction of the web through the first sterilization device.

[0066] The second sterilization device 7 can be configured to sterilize parts P1, P2, P3 of the web 4 and the first sterilization device 10 and / or generally the sterilization equipment 9.

[0067] As a further precautionary measure, the second sterilization device 7 can be configured to sterilize the isolation chamber 14.

[0068] The injection tank 70 can be connected to another pipe 76, which is configured to convey vaporized hydrogen peroxide at the isolation chamber 14. Specifically, the pipe 76 can terminate downstream of the pipe forming device 17.

[0069] The injection tank 70 can be configured to sterilize the isolation chamber 14 using another pipe 76. The air (e.g., air flow) flowing out of the other pipe 76 can pass through the isolation chamber 14, the first sterilization device 10, and can be collected through the pipe 74.

[0070] In other words, when the web advancement is interrupted, the second sterilization device 7 can be configured to inject sterilizing air containing hydrogen peroxide into the first sterilization device 10, and preferably through the isolation chamber 14.

[0071] The second sterilization device 7 can be activated only when the web advancement is interrupted and / or the first sterilization device 10 is out of service.

[0072] According to one or more embodiments, the movement sensor 11 can include a rotary encoder, for example integrated within one of the plurality of conveyors configured to advance the web 4, preferably located upstream of the sterilization equipment 9. Preferably, the first conveyor 22 can include the movement sensor 11. However, any conveyor upstream of the sterilization equipment 9 can include the movement sensor 11.

[0073] The conveyor containing the movement sensor 11 can be unaffected by the driving force. In other words, the conveyor can include a free roller that rotates only due to the movement of the web 4. No external force is applied to the conveyor to affect its rotation. Thus, in an example, if the web 4 advances, the first conveyor 22 rotates in a first direction, e.g., counterclockwise in the figure; if the web 4 retreats, the first conveyor 22 rotates in a second direction opposite to the first direction, e.g., clockwise.

[0074] Advantageously, this can read the distance D more accurately because the possible backward movement of the packaging material web 4 is also taken into account.

[0075] The second conveyor can contact the web 4 at the conveyor containing the movement sensor 11, which is on the other side of the web 4 relative to the conveyor containing the movement sensor 11. Thus, the packaging material web 4 does not slide on the conveyor, enabling a more accurate reading.

[0076] According to one or more embodiments, one or more conveyors (e.g., located (immediately) upstream of the sterilization device 9) may include an actuator configured to control the braking speed of the advancing web 4. Advantageously, this can reduce the travel distance D of the web 4 before interruption.

[0077] Additionally or alternatively, the actuator may be configured to control the tension of the advancing web 4. Advantageously, in this way, when the packaging machine 1 stops, the web 4 of the packaging material also remains tensioned, which helps with sterilization and reduces the risk of damage to the web 4.

[0078] In one or more embodiments, the first conveyor 22 may include a movement sensor 11 and an actuator. Additionally or alternatively, other conveyors (immediately) upstream of the first conveyor 22, for example, may include an actuator.

[0079] The control unit 12 may be configured to resume the advancement of the web 4 of the packaging material after the sterilization step is completed using the second sterilization device 7. That is, before, during, and after the anomaly detection, the web 4 of the packaging material remains within the packaging machine 1.

[0080] During the step of sterilizing using the second sterilization device 7, at least the package 2 formed by the packaging material within the sterilization device 9 and the isolation chamber 14 may be discarded.

[0081] According to one or more embodiments, the control unit 12 may be configured to send an alarm signal to, for example, the user interface if the travel distance D is greater than a predetermined distance (e.g., the distance D1 between the first sterilization device 10 and the outlet 92 of the sterilization device 9). Then, the isolation chamber 14, the filling unit 20, and the sterilization device 9 are cleaned and re-sterilized.

[0082] One or more embodiments may relate to a method of sterilizing a web 4 of packaging material using a sterilization device 9 according to one or more embodiments. The method may include: - advancing the web 4 of the packaging material along a web advancement path P; - sterilizing at least a first side 5 of the advancing web 4 using a first sterilization device 10, preferably also sterilizing a second side 6; - monitoring the operation of the first sterilization device 10; - monitoring the advancement of the web 4 along the advancement path P; and - if an abnormal operation of the first sterilization device 10 is detected, then: - interrupt the advancement of the web 4; - identify the travel distance D of the web 4 between the detection of the anomaly and the interruption of the advancement; and - Sterilize at least a part P1, P2, P3 of the web 4 by means of the second sterilization device 7, the parts P1, P2, P3 of the web being related to the travel distance D.

[0083] The advantages of the sterilization device 9 according to the invention will be apparent from the foregoing description. Specifically, relative to the prior art, the sterilization device 9 can minimize the downtime of the packaging machine 1. More specifically, the downtime can be reduced from several hours to several tens of minutes.

[0084] Obviously, the sterilization device 9 described herein can be modified without departing from the scope of protection defined by the appended claims.

Claims

1. A sterilization device (9) for sterilizing a web of packaging material (4) advancing along an advancing path (P), the sterilization device (9) comprising: - A first sterilization device (10) configured to sterilize at least a first face (5) of the web (4) advancing through the first sterilization device (10); - A second sterilization device (7); - A monitoring device (8) configured to monitor the operation of the first sterilization device (10); - A movement sensor (11) configured to monitor the advancement of the web (4) along the advancing path (P); And - A control unit (12) connected to the monitoring device (8) and the movement sensor (11), the control unit (12) being configured to, when an abnormal operation of the first sterilization device (10) is detected: - Interrupt the advancement of the web (4); - Identify the travel distance (D) of the web (4) between the detection of the abnormality and the interruption of the advancement, and - Sterilize at least a portion (P1, P2, P3) of the web (4) using the second sterilization device (7), the portion (P1, P2, P3) of the web being related to the travel distance (D).

2. The sterilization device (9) according to claim 1, comprising an outlet (92), and wherein the travel distance (D) is less than the distance (D1) between the first sterilization device (10) and the outlet (92).

3. The sterilization device (9) according to claim 1 or 2, wherein, The step of detecting an abnormal operation of the first sterilization device (10) comprises: - Receiving a sensor signal from the monitoring device (8), and - Checking whether the sensor signal reaches a predetermined threshold within a predetermined time period, preferably whether it continuously reaches the predetermined threshold.

4. The sterilization device (9) according to any one of the preceding claims, wherein, The first sterilization device (10) comprises an irradiation device configured to sterilize at least the first face (5) of the advancing web (4) by directing sterilizing radiation onto the first face (5), and wherein the abnormality is an arc event.

5. The sterilization device (9) according to claim 4, wherein, The monitoring device (8) comprises an irradiation sensor configured to detect the radiation dose emitted by the first sterilization device (10), and wherein the control unit (12) is configured to detect an abnormality when the emitted radiation dose reaches a predetermined threshold.

6. The sterilization device (9) according to any one of the preceding claims, wherein, The second sterilization device (7) comprises a hydrogen peroxide spray tank (70) configured to spray vaporized hydrogen peroxide at least at the portion (P1, P2, P3) of the web (4).

7. The sterilization device (9) according to any one of the preceding claims, wherein, The movement sensor (11) comprises an encoder integrated within a conveyor (22) configured to advance the web (4).

8. The sterilization device (9) according to claim 7, wherein, The conveyor (22) is not affected by a driving force.

9. The sterilization device (9) according to any one of the preceding claims, wherein, The control unit (12) is configured to emit an alarm signal when the travel distance (D) is greater than a predetermined distance, wherein, preferably, the predetermined distance corresponds to the distance (D1) between the first sterilization device (10) and the outlet (92) of the sterilization device (9).

10. The sterilization device (9) according to any one of the preceding claims, wherein, The control unit (12) is configured to resume the advancement of the packaging material web (4) after completion of the step of sterilization using the second sterilization device (7).

11. The sterilization device (9) according to any one of the preceding claims, wherein, The second sterilization device (7) is configured to sterilize the portions (P1, P2, P3) of the web (4) and the first sterilization device (10).

12. A packaging machine (1) for producing sealed packages (2) of pourable products from a packaging material web (4), the packaging machine (1) comprising at least: - a sterilization device (9) according to any one of the preceding claims; - an isolation chamber (14) connected to the sterilization device (9) and separating an internal environment (15) from an external environment (16); - a tube forming device (17) at least partially disposed within the isolation chamber (14) and configured to form a tube (3) from the packaging material web (4); - a sealing device (19) at least partially disposed within the isolation chamber (14) and configured to longitudinally seal the tube (3) formed by the tube forming device (17); - a filling unit (20) configured to fill the tube (3) with the pourable product; - a package forming unit (21) configured to form and transversely seal the tube (3) to form the package (2); and - a plurality of conveyors (22, 23) configured to advance the packaging material web (4) along a web advancement path (P) and to advance the tube (3) along a tube advancement path (Q).

13. The wrapping machine (1) according to claim 12, comprising a conveyor (22) located upstream of the sterilization device (9), wherein, The movement sensor (11) includes an encoder integrated within the conveyor (22).

14. The packaging machine (1) according to claim 12 or 13, wherein, The plurality of conveyors includes at least one conveyor located upstream of the sterilization device (9), the conveyor including an actuator configured to control the braking speed of the advancing web (4) and / or to control the tension of the advancing web (4).

15. A method for sterilizing a packaging material web (4), comprising the steps of: - advancing the packaging material web (4) along a web advancement path (P); - sterilizing at least a first face (5) of the advancing web (6) using a first sterilization device (10); - monitoring the operation of the first sterilization device (10); - monitoring the advancement of the web (4) along the advancement path; and - if an abnormal operation of the first sterilization device (10) is detected, then: - interrupting the advancement of the web (4); - identifying the advancement distance (D) of the web (4) between detection of the abnormality and interruption of the advancement, and - sterilizing at least a portion (P1, P2, P3) of the web (4) using the second sterilization device (7), the portion (P1, P2, P3) of the web being related to the advancement distance (D).

Images