Combined UV-light and electron beam sterilization of a web of packaging material within a packaging machine

Abstract

The present invention relates to a method for, within a packaging machine configured to fill packages with a food product, sterilization of a web of packaging material comprising 3D structures. The method comprising: subjecting, at a first UV-light irradiation station, the 3D structures in the web for UV-light irradiation; and subjecting, at an electron beam irradiation station, both the 3D structures in the web and a surface of the web of packaging material for electron beam irradiation. A sterilization arrangement comprising a UV-light irradiation station and an electron beam irradiation station is also presented. Moreover, a packaging machine configured to fill packages with a food product, the packaging machine comprising the sterilization arrangement, is also presented.

Description

[0001] COMBINED UV-LIGHT AND ELECTRON BEAM STERILIZATION OF A WEB OF PACKAGING MATERIAL WITHIN A PACKAGING MACHINE

[0002] Technical field

[0003] The present invention relates to sterilization of a web of packaging material within a packaging machine for filling packages with food products, typically liquid food products. Especially, a sterilization based on a combined irradiation of the packaging material within UV-light and an electron beam. It is further to be noted that whenever sterilization is discussed herein, it also applies to disinfection, depending on the target for the irradiation using UV-light and an electron beam.

[0004] Background of the invention

[0005] Within the food industry today, the food package technology plays an important part. The food package has several important functions. Apart from branding of the product and presenting the customers with information, the food package also has an important role of ensuring food safety. The packaging materials used in the food package can be designed to provide strength and stability, so that the packages are not damaged during transportation. Furthermore, the packaging materials can form a protective environment for the food product so that it is protected from for example bacteria, germs, oxygen and sun light, thus prolonging shelf life. However, the packaging material is not the only thing that is important in the package. The package need to be subjected to sterilization before filling the package with food. This in order to increase shelf life of the food in the package and to ensure food safety.

[0006] Performing sterilization of packaging material may be challenging and a variety of sterilization methods, including thermal methods, such as steam sterilization and hot air sterilization, chemical methods, such as hydrogen peroxide (H2O2) sterilization and peracetic acid sterilization, and irradiation methods, such as gamma irradiation, electron beam irradiation and ultra violet, UV, light irradiation, have been implemented in the industry. Current sterilization methods of packaging material leave room for improvements, especially when it comes to sterilization of a web of packaging material comprising 3D structures, such as an opening device packaging material interface, a sealing strip or an opening device.

[0007] 2787-2482-2032, v. 2 Summary of the invention

[0008] The herein disclosed technology seeks to at least partly mitigate, alleviate or eliminate one or more of the above-mentioned deficiencies and disadvantages in the prior art. In particular, it is an object to provide efficient sterilization of a web of packaging material within a packaging machine, which web comprises 3D structures, such as an opening device packaging material interface, a sealing strip or an opening device. The inventors of the present inventive concept has realized a new and improved way of sterilizing such a web of packaging material, especially in connection with high speed filling in a packaging machine.

[0009] Various aspects and embodiments of the disclosed invention are defined below and in the accompanying independent and dependent claims.

[0010] According to a first aspect, a method for sterilization of a web of packaging material comprising 3D structures is provided. The method being performed in a packaging machine configured to fill packages with a food product. The method comprising: subjecting, at a first UV-light irradiation station, the 3D structures in the web for UV-light irradiation; and subjecting, at an electron beam irradiation station, both the 3D structures in the web and a surface of the web of packaging material for electron beam irradiation.

[0011] According to the present inventive concept UV light irradiation and electron beam irradiation is combined in order to achieve sterilization of the web of packaging material comprising 3D structures. Using a compact UV-LED based systems for the UV-light irradiation makes it easy to fit in a UV-light irradiation station in a packaging machine. The present invention allow for exploiting a synergetic effect that has been realized by the inventors, namely that irradiating the packaging material with both UV- light and an electron beam drastically increases the effectiveness of killing microorganism as compared with using UV-light and electron beam irradiation separately. Using this surprising effect allow for reducing the dose needed from the electron beam irradiation. Tests conducted by the inventors indicate that a preirradiation with UV-light may reduce the required electron beam dose dramatically. According to tests conducted by the inventors an exposure to 3 kGy electron beam irradiation does not result in any detectable inactivation of Clostridium Botulinum. Exposure to 8 mJ / cm2UV light exposure gives an inactivation of a log count reduction of 1.6. However, when exposing first to 8 mJ / cm2UV light, followed by exposure to 3 kGy electron beam irradiation, then the resulting log count reduction was 4.5, i.e. the combined effect of the two types of exposure resulted in three log count reduction

[0012] 2787-2482-2032, v. 2 higher inactivation than expected if the contributions from the respective exposures would be additive. These tests are summarized in connection with Table 1 to be found further down this text. Further, these tests are also to be compared with nominal process values for electron beam dosage that is typically 30 kGy in order to achieve log count reduction above 4. Using this result when sterilizing packaging material is allowing to downsize the electron beam irradiation station, extending the lifetime of the electron beam irradiation station and / or decreasing the power consumption. Further, by being able to reduce the dose from the electron beam irradiation station problems with off-taste and reduced sealability due to electron beam irradiation of the packaging material may be reduced. Moreover, a lifetime of the electron beam irradiation station may be prolonged. Furthermore, reducing the dose from the electron beam irradiation station allow for sterilizing more delicate packaging material, e.g. a packaging material with new barrier structures replacing the Aluminum foil. Additionally, the proposed method allow for achieving sterilization of “problematic” areas in the 3D structures and / or in an interface between the 3D structures and the packaging material that are hard to reach by the electron beam, e.g. due to shadowing. According to the present invention local UV-light irradiation is introduced to increase sterilization of such “problematic” areas. This since it is evident that inventive concept of combining UV light irradiation and electron beam irradiation enables sterilization by irradiation on complex 3D structures as the required UV light exposure and electron beam dose needed to obtain a target inactivation will be drastically reduced.

[0013] The electron beam irradiation may be performed after the UV-light irradiation. It has been realized that this order of irradiation is especially effective.

[0014] The 3D structures in the web may be a type of structure selected from the group of structures consisting of: an opening device packaging material interface, a sealing strip and an opening device.

[0015] The first UV-light irradiation station and the electron beam irradiation station may be stationary stations. The method may further comprise feeding the web of packaging material through the first UV-light irradiation station and the electron beam irradiation station. The feeding is preferably continuous. The feeding is performed while subjecting the 3D structures in the web for UV-light irradiation and subjecting both the 3D structures in the web and a surface of the web of packaging material for electron beam irradiation.

[0016] The method may further comprise turning the first UV-light irradiation station on while a 3D structure in the web passes through the first UV-light irradiation station and

[0017] 2787-2482-2032, v. 2 turning the first UV-light irradiation station off while no 3D structure in the web passes through the first UV-light irradiation station.

[0018] The first UV-light irradiation station may comprise a first plurality of UV-LED units arranged along a feeding direction of the web of packaging material. The method may further comprise individually turning the first plurality of UV-LED units on / off as a 3D structure in the web passes through the first UV-light irradiation station.

[0019] The method may further comprise subjecting, at a second UV-light irradiation station, the surface of the web of packaging material for UV-light irradiation. The UV- light irradiation at the second UV-light irradiation station may be performed before the electron beam irradiation.

[0020] A full width of the web of packaging material may be irradiated in the second UV-light irradiation station and in the electron beam irradiation station, respectively.

[0021] Both sides of the web of packaging material may subjected for the UV-light irradiation and the electron beam irradiation, respectively.

[0022] The present invention relates to a method combining UV-light and electron beam irradiation for sterilization. This approach takes advantage of the differing sensitivities of microorganisms to UV and electron beam treatments, resulting in a synergistic effect that enhances sterilization efficacy while allowing for reduced treatment intensities. This synergy enables effective microbial inactivation while minimizing material degradation and operational costs.

[0023] The present invention relates to a method and arrangement for sterilizing packaging material within a packaging machine by sequentially subjecting the same surface of the packaging material to ultraviolet (UV) light irradiation followed by electron beam irradiation. These irradiation steps are performed at dedicated, stationary UV- light and electron beam irradiation stations integrated within the packaging machine, through which the packaging material, typically provided as a continuous web, is fed.

[0024] This combined sequential irradiation provides a synergistic sterilization effect that significantly enhances the inactivation of microorganisms compared to using either UV-light or electron beam irradiation alone. As a result, the required electron beam dose can be substantially reduced. This reduction leads to several important advantages, including lower power consumption, decreased wear on the electron beam equipment, and importantly, minimized risk of off-taste development in the packaged food product.

[0025] “Off-taste” refers to undesirable changes in flavour or odour of the food product caused by chemical or physical alterations in the packaging material due to high doses

[0026] 2787-2482-2032, v. 2 of electron beam irradiation. By lowering the electron beam dose through the synergistic effect with UV-light, the present invention helps preserve the original taste and quality of the food.

[0027] The integration of these irradiation stations allows for efficient sterilization compatible with high-speed packaging operations, ensuring food safety and prolonging product shelf life without compromising packaging material integrity.

[0028] In the present inventive concept, ultraviolet light-emitting diodes (UV-LEDs) are used as the preferred source for UV-light irradiation in the UV-light irradiation station. UV-LEDs provide a compact and energy-efficient light source that facilitates easy integration within the packaging machine, which often has limited space and requires high-speed and precise operation. The UV-LEDs have long operational lifetimes and allow for rapid and accurate control of UV-light exposure, enabling optimal microbial inactivation.

[0029] The UV-LEDs are configured to emit UV-light with a peak wavelength in the range of 260-275 nm, preferably between 265-275 nm, which is especially effective for inactivating microorganisms. Without being bound by theories this wavelength range may contribute to the synergistic sterilization effect achieved by sequentially subjecting the packaging material to UV-light irradiation other factors, such as the timing between irradiations and sample handling, may also influence the synergy. Regardless of the exact cause, the combined treatment results in significantly enhanced microorganism inactivation compared to either irradiation alone.

[0030] By employing UV-LEDs, the UV-light irradiation station can be positioned in close vicinity to the electron beam irradiation station within the packaging machine, minimizing the risk of recontamination of the packaging material between irradiation steps. This arrangement enables a compact and efficient sterilization solution well suited for high-speed packaging operations.

[0031] The sequential configuration of the irradiation systems results in a synergistic effect, wherein the overall performance exceeds the sum of the effects produced by the individual systems operating separately. This indicates that the sequential arrangement enables emergent properties or cooperative interactions that are not achievable through independent use.

[0032] According to a second aspect a sterilization arrangement for sterilization of a web of packaging material comprising 3D structures is provided. The sterilization arrangement is configured to be arranged in a packaging machine configured to fill packages with food product. The packaging machine being feed with the web of

[0033] 2787-2482-2032, v. 2 packaging material. The sterilization arrangement comprising the following stations: a first UV-light irradiation station configured to subject the 3D structures in the web for UV-light irradiation; and an electron beam irradiation station configured to subject both the 3D structures in the web and a surface of the web for electron beam irradiation.

[0034] The first UV-light irradiation station may be arranged before the electron beam irradiation station in a feeding direction of the web of packaging material.

[0035] The first UV-light irradiation station may comprise a second plurality of UV-LED units arranged to illuminate the 3D structures from different angles relative the surface of the web of packaging material. This allow for better reaching areas of the 3D structures and / or the web being shadowed by the 3D structures. All UV-LED units arranged along a line transverse the feeding direction of the web may be turned on at the same time treating a 3D structure from different angles.

[0036] The sterilization arrangement may further comprise an additional station in the form of a second UV-light irradiation station configured to subject the surface of the web of packaging material for UV-light irradiation. The second UV-light irradiation station may be arranged before the electron beam irradiation station in a feeding direction of the web of packaging material.

[0037] The electron beam irradiation station may be located in vicinity of the first and / or second UV-light irradiation stations as seen along a traveling direction of the web of packaging material being subjected for the sterilization in the sterilization arrangement. In this context, in vicinity refer to a distance in the order of 0 meter to 10 meters.

[0038] The second UV-light irradiation station and the electron beam irradiation station may be configured to irradiate a full width of the web of packaging material, respectively. The first UV-light irradiation station, the second UV-light irradiation station and the electron beam irradiation station may be configured to irradiate both sides of the web of packaging material / 3D structures, respectively.

[0039] The above mentioned features of the first aspect, when applicable, apply to this second aspect as well. In order to avoid undue repetition, reference is made to the above.

[0040] According to a third aspect a packaging machine configured to fill packages with a food product is provided. The packaging machine comprising: a sterilization arrangement according to the second aspect, wherein the stations of the sterilization arrangement are stationary stations; and a feed unit configured to feed the web of packaging material through the sterilization arrangement. The feeding preferably

[0041] 2787-2482-2032, v. 2 continuous. The packaging machine may be configured to form the web of packaging material into the filled packages.

[0042] The sterilization arrangement may comprise a control circuitry configured to turn the first UV-light irradiation station on while a 3D structure in the web passes through the first UV-light irradiation station and turn the first UV-light irradiation station off while no 3D structure in the web passes through the first UV-light irradiation station.

[0043] The first UV-light irradiation station may comprise a first plurality of UV-LED units arranged along a feeding direction of the web, wherein the control circuitry is configured to individually turn the first plurality of UV-LED units on / off as a 3D structure in the web passes through the first UV-light irradiation station.

[0044] The packaging machine may further comprise a filling station configured to fill the packages with the food product.

[0045] The packaging machine may be configured to fill at least 4000 packages per hour per packaging line.

[0046] The above mentioned features of the first aspect, when applicable, apply to this third aspect as well. In order to avoid undue repetition, reference is made to the above.

[0047] A further scope of applicability of the present disclosure will become apparent from the detailed description given below. However, it should be understood that the detailed description and specific examples, while indicating preferred variants of the present inventive concept, are given by way of illustration only, since various changes and modifications within the scope of the inventive concept will become apparent to those skilled in the art from this detailed description.

[0048] Brief description of the drawings

[0049] The above and other aspects of the present inventive concept will now be described in more detail, with reference to appended drawings showing variants of the present inventive concept. The figures should not be considered limiting the invention to the specific variant; instead, they are used for explaining and understanding the inventive concept.

[0050] As illustrated in the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of variants of the present inventive concept. Like reference numerals refer to like elements throughout.

[0051] Fig. 1 schematically illustrates a packaging machine configured to fill packages with a liquid food product, the packaging machine being equipped with a packaging

[0052] 2787-2482-2032, v. 2 sterilization arrangement comprising both UV-light irradiation stations and an electron beam irradiation station.

[0053] Fig. 2 schematically illustrates a UV-light irradiation station configured to subjecting 3D structures on a web of packaging material for UV-light irradiation.

[0054] Fig. 3 is a block diagram of a method for sterilization of a web of packaging material comprising 3D structures within a packaging machine configured to fill packages with a food product, the sterilization being based on subjecting the web and the 3D structures for both UV-light and electron beam irradiation.

[0055] Detailed description

[0056] The present inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred variants of the inventive concept are shown. This inventive concept may, however, be implemented in many different forms and should not be construed as limited to the variants set forth herein; rather, these variants are provided for thoroughness and completeness, and fully convey the scope of the present inventive concept to the skilled person.

[0057] It will also be appreciated that when the present disclosure is described in terms of a method, it may also be embodied in an apparatus or device comprising one or more processors, one or more memories coupled to the one or more processors, where computer code is loaded to implement the method. For example, the one or more memories may store one or more computer programs that perform the steps, services and functions disclosed herein when executed by the one or more processors.

[0058] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context clearly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may refer to more than one unit in some contexts, and the like. Furthermore, the words "comprising", "including", "containing" do not exclude other elements or steps. It should be emphasized that the term “comprises / comprising” when used in this specification is taken to specify the presence of stated features, integers, steps, or components. It does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof. The term “and / or” is to be interpreted as meaning “both” as well and each as an alternative. The term “obtaining”

[0059] 2787-2482-2032, v. 2 is herein to be interpreted broadly and encompasses receiving, retrieving, collecting, acquiring, and so forth.

[0060] Fig. 1 generally illustrates, a packaging machine 100 configured to fill packages with a food product, according to some examples a liquid food product. The packaging machine 100 is a roll-fed packaging machine used for producing packages. That is, the packaging machine 100 is feed with a web 102 of packaging material to be formed into filled packages. The web 102 of packaging material is typically flat. More specifically, the packaging machine 100 may be used for packaging food products in carton-based packages. Already in the 1940s this type of packaging machines was introduced by Tetra Pak® and it is today a well-known approach for packaging milk and other food products in a safe and cost-efficient manner. The packaging material typically comprises a carton layer and at least one plastic layer. The packaging material is often printed and prepared in packaging material production centers, also referred to as converting factories, and shipped to a site where the packaging machine 100 is placed, e.g. a dairy. For a roll-fed packaging machine 100 the packaging material is loaded onto a reel before being transported. After arriving at the site, the reel is placed in the packaging machine 100, and a web 102 of packaging material is fed in the packaging machine 100 by a feed unit 110. The feeding of the web 102 of packaging material is typically continuous.

[0061] The web 102 of packaging material is typically a flat web, i.e. the web is in the form of a 2D structure. However, for some applications, in the process of forming packaging material into filled packages, structures having a 3D extension is applied to the flat web. Examples of such 3D structures 103 are an opening device (e.g. a cap to be used to later on open the package), an opening device packaging material interface at which an opening device later on is to be applied, and a sealing strip to be used to form a seal between two surfaces of the packaging material when forming the packages. The such 3D structures 103 may be applied to the web 102 of packaging material within the packaging machine 100. According to one example, 3D structures 103 in the form of opening devices are injection molded onto the flat web 102 of packaging material. According to another example, 3D structures 103 in the form of sealing strip are applied to the flat web 102 of packaging material. Hence, the 2D geometry of portions of the flat web 102 is now replaced with a 3D geometry that extends out of the plane introducing areas that may be more difficult to treat during a sterilization before the package being filled. An example of areas that may be more difficult to treat during a sterilization are areas being, as seen from a sterilization

[0062] 2787-2482-2032, v. 2 treatment point (e.g. using an electron beam or UV-light for sterilization), shaded by the 3D structure 103. Such shades regions may introduce a problem in sterilization. The present invention is directed towards introducing means for improving sterilization of a web 102 of packaging material comprising 3D structures 103 as discussed above.

[0063] It has been realized by the inventors that an improved sterilization of a web 102 of packaging material comprising 3D structures 103 can be achieved by combining irradiation with UV-light and irradiation with an electron beam. According to the present invention the 3D structures 103 in the web 102 are locally treated by UV-light. Further, the full web 102 and the 3D structures 103 in the web are treated by an electron beam. The combined irradiation with UV-light and irradiation with an electron beam is provided by a sterilization arrangement 120 comprised in the packaging machine 100. The sterilization arrangement 120 is configured to sterilize the web 102 of packaging material comprising 3D structures 103. Especially, the sterilization arrangement 120 is configured to sterilize the web 102 of packaging material comprising 3D structures 103 before a respective package is formed and filled with the food product. More, specifically the packaging sterilization arrangement 120 may be configured to sterilize both sides of the web 102 of packaging material before the respective package is formed and filled with the food product.

[0064] The sterilization arrangement 120 will now be discussed in more detail. The sterilization arrangement 120 is designed based on an insight made by the inventors, namely that irradiating with both ultra violet, UV, light and a beam of electrons is resulting in an increased killing of microorganisms as compared with only performing a separate UV-light irradiation or only performing a separate irradiation with a beam of electrons. Table 1 below is a summary of experimental results illustrating the combined effect of using UV-light and a beam of electrons.

[0065] Table 1. Inactivation of Clostridium Botulinum of strain 33A for different combinations of UV-light and eBeam irradiation.

[0066] 2787-2482-2032, v. 2 The found combined effect of using UV-light and a beam of electrons (eBeam) allows for downsizing the sterilization arrangement, extending the lifetime of the sterilization arrangement and / or decreasing the power consumption. Further, by irradiation of the 3D structures 103 with both UV-light and an electron beam sterilization of shaded areas in connection with the 3D structures may be improved due to the combined effect of UV and electron beam irradiation. Hence, sterilization of 3D structures otherwise not feasible may be enabled. Moreover, by the combined irradiation with both UV-light and electron beam also a downsizing of the 3D structures, i.e. opening devises may be made possible.

[0067] Hence, the sterilization arrangement 120 has been designed to comprise both a first UV-light irradiation station 122 and an electron beam irradiation station 124. Preferably, just as in the in Fig. 1 illustrated example, the electron beam irradiation station 124 is located downstream of the first UV-light irradiation station 122 along a feeding direction of the web 102 of packaging material being fed through the packaging machine 100 by the feed unit 110. The feed unit 110 may be configured to feed the web 102 continuously through the packaging machine 110. Further, the electron beam irradiation station 124 is preferably located in vicinity of the first UV-light irradiation station 122 as seen along a traveling direction of the web 102 of packaging material with 3D structures 103 being subjected for the sterilization in the sterilization arrangement 120. In this context, in vicinity refer to a distance in the order of 0 meter to 10 meters. Preferably, the UV-light irradiation station 122 is to be located as close to the electron beam irradiation station 124 as possible. There is no minimum distance required from the process perspective. It is more a matter of physical integration of the stations 122, 124. The maximum distance between the stations 122, 124 is not a fixed limit either. The principle should be to minimize the distance to minimize the risk of recontamination between exposures at the different stations 122, 124.

[0068] Both the first UV-light irradiation station 122 and the electron beam irradiation station 124 are typically stationary stations within the packaging machine 100.

[0069] The first UV-light irradiation station 122 is configured to subject the 3D structures 103 in the web 102 for UV-light irradiation. The first UV-light irradiation station 122 is configured to subject the 3D structures in the web 102 for UV-light irradiation while the web 102 is feed through the first UV-light irradiation station 122. The first UV-light irradiation station 122 may be configured to turn the first UV-light irradiation station 122 on while a 3D structure 103 in the web 102 passes through the first UV-light irradiation station 122. Further, first UV-light irradiation station 122 may be

[0070] 2787-2482-2032, v. 2 configured to turn the first UV-light irradiation station 122 off while no 3D structure 103 in the web 102 passes through the first UV-light irradiation station 122. This allow for treating a specific area of the web 102, i.e. the 3D structures 103, that occurs repetitively on the web 102. This will allow for reduced need of cooling the first UV-light irradiation station 122. Further, the energy may be saved and a lifetime of the first UV- light irradiation station 122 may be increased. The first UV-light irradiation station 122 may be configured to irradiate the 3D structures 103 from both a first side of the web 102 of packaging material and a second side of the web 102 of packaging material. That is the first UV-light irradiation station 122 may be configured to irradiate the 3D structures 103 from a side of the web 102 of packaging material that will constitute an inside and from a side of the web 102 of packaging material that will constitute an outside of the packages 104 being produced within the packaging machine 100. Accordingly, the first UV-light irradiation station 122 may be configured to irradiate both an inside and an outside of the 3D structures 103.

[0071] In connection with Fig. 2 a more detailed embodiment of the first UV-light irradiation station 122 will be discussed. The first UV-light irradiation station 122 may comprise an array of UV-LED units 210 arranged in a tunnel 200. Each such UV-LED unit 210 may comprise one or more UV-LEDs. There may be first plurality of UV-LED units 210 arranged along a feeding direction D of the web 102 of packaging material. The first plurality of UV-LED units 210 may be controlled to be individually turned on / off as a 3D structure 103 in the web 102 passes through the first UV-light irradiation station 122. Hence, stationary UV-LED units 210 arranged along a line parallel with the feeding direction D of the web 102 of packaging material may be turned on one after the other as a 3D structure 103 passes by and turned off when the 3D structure 103 has passed. This allow for treating a specific area of the web 102, i.e. the 3D structures 103, that occurs repetitively on the web 102. This will allow for reduced need of cooling the UV-LEDs 210. Further, the energy may be saved and a lifetime of the UV-LEDs of the first UV-light irradiation station 122 may be increased. All the above may be achieved while being able to irradiate the 3D structures with a high enough UV-light intensity. Further, having the first plurality of UV-LED units 210 arranged along a feeding direction D of the web 102 of packaging material allow for having a throughput of 3D structures, e.g. in the form of opening devices and hence packages, of 4000 or more per hour while achieving high enough UV-light intensity. There may be second plurality of UV-LED units 210 arranged transvers the feeding direction D of the web 102 of packaging material. Preferably, the different UV-LED units 210 of the second

[0072] 2787-2482-2032, v. 2 plurality of LIV-LED units 210 are arranged to illuminate the 3D structures 103 from different angles relative the surface of the web 102 of packaging material. This allow for better reaching areas of the 3D structures 103 and / or the web 102 being shadowed by the 3D structures 103. All LED units 210 arranged along a line transverse the feeding direction D may be turned on at the same time treating a 3D structure 103 from different angles. Above, UV-light sources in the form of UV-LEDs have been discussed, it is however readily understood that other types of UV-light emitting light sources may be used.

[0073] The electron beam irradiation station 124 is configured to subject a surface of the web 102 of packaging material for an electron beam irradiation while the web 102 is feed through the electron beam irradiation station 124. Typically, the electron beam irradiation station 124 is configured to irradiate a full width of the web 102 of packaging material. In addition, the electron beam irradiation station 124 is also configured to irradiate the 3D structures 103 in the web 102.

[0074] In more detail, the electron beam irradiation station 124, also referred to as an eBeam station, is configured to emit a beam of electrons, or in short an eBeam. An eBeam is a stream of electrons used for various applications, including disinfection of packaging materials. The technology leverages the properties of high-energy electrons to effectively kill microorganisms and sterilize surfaces. Typically, eBeam systems for disinfection operate at energies of 10ths of keV up to 10 MeV. An electron beam is produced by an electron gun, which typically consists of a heated filament that emits electrons when a voltage is applied. The emitted electrons are accelerated using an electric field. This acceleration gives the electrons the energy needed for effectively kill microorganisms. The accelerated electrons may be focused into a narrow beam using magnetic or electrostatic lenses. Such a beam is then scanned across the target area, which in this case is the packaging material. This scanning ensures uniform exposure to the electron beam. Alternatively, the beam is a non-focused beam configured to irradiate the full width of the web of packaging material as the web passes the beam. The penetration depth of the electron beam depends on its energy. As mentioned above, eBeam systems for disinfection typically operate at energies of 10ths of keV up to 10 MeV. Higher energy beams penetrate deeper into materials, which is useful for ensuring that microorganisms embedded within the material are also killed. When the high-energy electrons from the eBeam collide with microorganisms on the surface of the packaging material, they cause ionization and excitation of the molecules within these organisms. This interaction damages the DNA and other critical cellular

[0075] 2787-2482-2032, v. 2 components of the microorganisms, effectively killing them or rendering them unable to reproduce. The process is very rapid making it suitable for high-throughput industrial applications. eBeam disinfection is a non-thermal process, meaning it does not rely on heat. This is advantageous for packaging materials that might be sensitive to high temperatures. The technology does not require the use of chemicals, making it environmentally friendly and reducing the risk of chemical residues on the packaging material. eBeam can be used on a variety of packaging materials, including cartoon, plastics, glass, and composites, without causing significant changes to their properties. Monitoring systems may be in place to ensure that a correct dose of radiation is administered. Sensors and feedback mechanisms may adjust the beam parameters to maintain optimal sterilization levels. eBeam facilities incorporate shielding and safety interlocks to protect operators from radiation exposure. Only the target material is exposed to the electron beam within a controlled environment.

[0076] During operation of the electron beam irradiation station 124, the electron beam irradiation station 124 is configured to irradiate the surface of the web 102 of packaging material with a beam of electrons. Further, the electron beam irradiation station 124 is configured to irradiate the 3D structures 103. A minimum dose required for electron beam irradiation will be dependent on the geometry of the 3D structure 103 as well as the preceding UV-light exposure. By irradiation of the 3D structures 103 with both UV- light and an electron beam, improved sterilization of the 3D structures 103 may be achieved due to the combined effect of UV and electron beam irradiation.

[0077] The electron beam irradiation station 124 may be configured to irradiate both the first side of the web 102 of packaging material, being the side of the web 102 of packaging material that will constitute the inside of the packages 104 being produced within the packaging machine 100, and the second side of the web 102 of packaging material, being the side of the web 102 of packaging material that will constitute the outside of the packages 104 being produced within the packaging machine 100. Accordingly, the electron beam irradiation station 124 may be configured to irradiate both sides of the web 102 of packaging material. The electron beam irradiation station 124 may further be configured to irradiate the 3D structures 103 from both the first side of the web 102 of packaging material and the second side of the web 102 of packaging material. That is the electron beam irradiation station 124 may be configured to irradiate the 3D structures 103 from a side of the web 102 of packaging material that will constitute an inside and from a side of the web 102 of packaging material that will constitute an outside of the packages 104 being produced within the packaging

[0078] 2787-2482-2032, v. 2 machine 100. Accordingly, the electron beam irradiation station 124 may be configured to irradiate both an inside and an outside of the 3D structures 103.

[0079] The sterilization arrangement 120 may further comprise a second UV-light irradiation station 123. The second UV-light irradiation station 123 is configured to subject the surface of the web 102 of packaging material for UV-light irradiation while the web 102 is feed through the second UV-light irradiation station 123. Typically, the second UV-light irradiation station 123 is configured to irradiate a full width of the web 102 of packaging material. The second UV-light irradiation station 123 comprises a plurality of UV-LEDs. The plurality of UV-LEDs are typically arranged along a line transvers the feeding direction of the web 102. During operation of the second UV-light irradiation station 123, the UV-LEDs are configured to emit UV-light towards the surface of the web 102 of packaging material. The second UV-light irradiation station 123 is configured to irradiate the surface of the web 102 of packaging material with UV- light . The second UV-light irradiation station 123 may comprise one set of UV-LEDs configured to irradiate a first side of the web 102 of packaging material and another set of UV-LEDs configured to irradiate a second side of the web 102 of packaging material. The first side of the web 102 of packaging material being the side of the web 102 of packaging material that will constitute an inside of the packages 104 being produced within the packaging machine 100. The second side of the web 102 of packaging material being the side of the web 102 of packaging material that will constitute an outside of the packages 104 being produced within the packaging machine 100. Accordingly, the second UV-light irradiation station 123 may be configured to irradiate both sides of the web 102 of packaging material.

[0080] In Fig. 1 the second UV-light irradiation station 123 is illustrated as being located downstream of the first UV-light irradiation station 122. However, the order of the first and second irradiation stations 122, 123 may be reversed so that the first UV- light irradiation station 122 is located downstream of the second UV-light irradiation station 123.

[0081] As been illustrated in table 1 , the combined effect of both UV-light and electron beam irradiation is apparent and strong at relatively low exposures and the effect is shown to be maintained also at higher exposures. The actual exposure of UV-light and electron beam required will depend on the application and the physical integration in the filling machine. Hence, an optimal distribution between UV-light exposure and electron Beam exposure is to be determined by considering different constraints and factors that needs to be taken into account when designing the sterilization

[0082] 2787-2482-2032, v. 2 arrangement 120. Further, to determine which setting and alarm limits to use will require considerations not only on whether it is an aseptic application or a chilled application but also on e.g. dose monitoring limitations for both the UV-light irradiation station 122 and the electron beam irradiation station 124, variation in UV light output, variation in electron beam output, limitations in physical space, and / or if there are other pathogens we need to consider in the dimensioning of the process apart Clostridium Botulinum

[0083] After having been sterilized, by means of the sterilization arrangement 120, the packaging material is formed into packages 104 and filled with the food product at a filling station 130. Alternatively, the packaging material is formed into a tube which is filled with the food product and thereafter being formed into packages 104. The filled packages 104 are then transported away from the packaging machine by a conveyor system 140.

[0084] In connection with Fig. 3, a method 300 for sterilization of a web 102 of packaging material comprising 3D structures 103 will be discussed. The method is performed within a packaging machine configured to fill packages with a food product. As discussed above, the packaging material may be carton based. As also discussed above, the packaging material is the form of a flat web 102. Below, the different steps of the method 300 are described in more detail. The steps of the method 300 is performed within the packaging machine, e.g. the packaging machine 100 discussed in connection with Fig. 1. Some of the steps, or even all steps, of the method 300 may be executed by a control unit of the packaging machine.

[0085] The method 300 comprises subjecting S302, at a first UV-light irradiation station 122, the 3D structures 103 in the web 102 for UV-light irradiation. The method 300 further comprise subjecting S304, at an electron beam irradiation station 124, both the 3D structures 103 in the web 102 and a surface of the web 102 for electron beam irradiation. The method 300 may further comprise, at a second UV-light irradiation station 123, subjecting S303 the surface of the web 102 for UV-light irradiation. The first UV-light irradiation station 122, the second UV-light irradiation station 123 and the electron beam irradiation station 124 are discussed in more detail above, in order to avoid undue repletion reference is made to that discussion.

[0086] During the step of subjecting S302, at the first UV-light irradiation station 122, the 3D structures 103 in the web 102 for UV-light irradiation, the first UV-light irradiation station 122 may be turned on while a 3D structure 103 in the web 102 passes through the first UV-light irradiation station 122. Moreover, the first UV-light irradiation station

[0087] 2787-2482-2032, v. 2 122 may be turned off while no 3D structure 103 in the web 102 passes through the first UV-light irradiation station 122.

[0088] Moreover, in case the first UV-light irradiation station 122 comprises a first plurality of UV-LED units 210 arranged along a feeding direction D of the web 102 of packaging material, during the step of subjecting S302, at the first UV-light irradiation station 122, the 3D structures 103 in the web 102 for UV-light irradiation, the first plurality of UV-LED units 210 may be individually turned on / off as a 3D structure 103 in the web 102 passes through the first UV-light irradiation station 122.

[0089] In the steps of subjecting S303 the surface of the web 102 of packaging material for UV-light irradiation and subjecting S304 the surface of web 102 of packaging material for electron beam irradiation it is a same portion of a the surface of the web 102 of packaging material that is subjected for the respective irradiation. The same portion is typically a portion of the web 102 of packaging material being feed through the packaging machine 100. However, the same portion is normally not subjected for the UV-light irradiation and the electron beam irradiation simultaneously. Instead, a portion of the packaging material is first subjected S303 for UV-light irradiation and at a later time subjected S304 for electron beam irradiation, or in some situations vice versa. The time between UV-light irradiation and electron beam irradiation of a same portion of the packaging material depend on the speed of feeding the web 102 of packaging material through the packaging machine 100 and on a distance between the second UV-light irradiation station 123 and the electron beam irradiation station 124. The time between UV-light irradiation and electron beam irradiation of a same portion of the web 102 of packaging material may be in a range of 0-10 seconds. In principle the time between UV-light irradiation and electron beam irradiation is to be minimized, this in order to protect the target surface from recontamination between the two irradiations. According to one specific embodiment, the irradiation of a same target surface with UV-light from the UV-light irradiation station 122 and the electron beam from the electron beam irradiation station 124 may be made simultaneously.

[0090] Further, as discussed above, a full width of the web 102 of packaging material is typically subjected for both the UV-light irradiation and the electron beam irradiation. Moreover, as also discussed above, both sides of the web 102 of packaging material may be subjected for the UV-light irradiation and the electron beam irradiation. As a result, while being feed thought the packaging machine 100 the complete surface area of the packaging material will be subjected for both the UV-light irradiation and the

[0091] 2787-2482-2032, v. 2 electron beam irradiation. Particularly, subjecting S303 and S304 the complete surface area of the packaging material for the UV-light irradiation and the electron beam irradiation is made prior to filling the packages. Subjecting S303 and S304 the complete surface area of the packaging material for the UV-light irradiation and the electron beam irradiation may further be made prior to forming the packaging material into the packages.

[0092] As being illustrated in connection with Fig. 3, subjecting S304 the surface of the packaging material for electron beam irradiation may be performed after subjecting S303 the surface of the packaging material for UV-light irradiation. It has been found by the inventors that such order of subjecting the surface of the packaging material for UV-light and electron beam irradiation provide for an increased killing effect of microorganisms as compared with first subjecting the surface of the web 102 packaging material for electron beam irradiation and thereafter subjecting the surface of the web 102 of packaging material for UV-light irradiation. It is however, to be realized that for some applications subjecting S304 the surface of the packaging material for electron beam irradiation may be performed before subjecting S303 the surface of the packaging material for UV-light irradiation.

[0093] As discussed above in connection with Fig. 1 and the discussion of the packaging machine 100 and the sterilization arrangement 120, the stations 122, 123, 134 of the sterilization arrangement 120 may be stationary stations. The method may further comprise feeding S301 the web of packaging material through the stations of the sterilization arrangement 120. Such feeding S301 of the web 102 of packaging material through the stations 122, 123, 124 of the sterilization arrangement 120 may be made continuously.

[0094] The person skilled in the art realizes that the present invention by no means is limited to what is explicitly described above. On the contrary, many modifications and variations are possible within the scope of the appended claims.

[0095] For example, one option for implementation of the present inventive concept of combined UV-light and electron beam irradiation is to expose a surface portion of the packaging material at which later on a 3D structure, e.g. a cap, is to be molded to UV- light before injection molding of the 3D structure. After the injection molding the packaging material and the molded 3D structure is exposed to electron beam irradiation. In this way any shaded interface area, would receive the UV-light exposure without any shading effect allowing for the electron beam irradiation to be relatively lowered to achieve a full inactivation.

[0096] 2787-2482-2032, v. 2 Further, the UV-LEDs may be arranged to emit UV-light having a peak wavelength in the range of 260-275 nm, more preferably in the range of 265-275 nm. Two examples of suitable UV-LEDs that can be used are OSRAM OSLON® UV 6060, SU CZHEF1.VC and OSRAM OSLON® UV 3535, SU CULEP1.VC. As understood by the skilled person, other UV-LEDs may of course be used. Further, as also understood by the skilled person, in the future UV-LEDs with higher power than available today will be developed. The plurality of UV-LEDs may all be of a same type having a same peak wavelength. Having, all UV-LEDs with the same peak wavelength will provide as high exposure as possible at that peak wavelength. Alternatively, the plurality of UV-LEDs may comprise two or more different types of UV-LEDs having different peak wavelengths. Having different peak wavelengths may be beneficial since different microorganism may have a different sensibility for different wavelengths.

[0097] Furthermore, the packaging machine 100 may comprise a clean air system 150. The clean air system 150 being arranged to enclosed the sterilization arrangement 120 and a portion of the feed unit 110 set to feed the packaging material between the first UV-light irradiation station 122 and the electron beam irradiation station 124 (or vice versa if the electron beam irradiation is to be performed before the UV-light irradiation). The clean air system 150 may further enclose the filling station 130. As readily understood by the skilled person, alternative to a clean-air system 150 other means of creating an environment protecting the surface from recontamination between UV-light and electron beam irradiation may be used.

[0098] Additionally, variations can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0099] 2787-2482-2032, v. 2

Claims

CLAIMS1. A method for, within a packaging machine (100) configured to fill packages with a food product, sterilization of a web (102) of packaging material comprising 3D structures (103), the method comprising: subjecting (S302), at a first UV-light irradiation station (122), the 3D structures (103) in the web for UV-light irradiation; and subjecting (S304), at an electron beam irradiation station (124), both the 3D structures (103) in the web and a surface of the web (102) of packaging material for electron beam irradiation.

2. The method according to claim 1 , wherein the 3D structures (103) in the web (102) is a type of structure selected from the group of structures consisting of: an opening device packaging material interface, a sealing strip and an opening device.

3. The method according to claim 1 or 2, wherein the first UV-light irradiation station (122) and the electron irradiation station (124) are stationary stations, wherein the method further comprises continuously feeding (S201) the web (102) of packaging material comprising the 3D structures (103) through the first UV-light irradiation station (122) and the electron irradiation station (124).

4. The method according to claim 3, further comprising turning the first UV-light irradiation station (122) on while a 3D structure (103) in the web (102) passes through the first UV-light irradiation station (122) and turning the first UV-light irradiation station (122) off while no 3D structure (103) in the web (102) passes through the first UV-light irradiation station (122).

5. The method according to claim 4, wherein the first UV-light irradiation station (122) comprises a first plurality of UV-LED units (210) arranged along a feeding direction (D) of the web (102) of packaging material, wherein the method further comprises individually turning the first plurality of UV-LED units (210) on / off as a 3D structure (103) in the web (102) passes through the first UV-light irradiation station (122).2787-2482-2032, v.

26. The method according to any one of claims 1-5, further comprising subjecting (S303), at a second UV-light irradiation station (123), the surface of the web (102) of packaging material for UV-light irradiation.

7. The method according to claim 6, wherein the UV-light irradiation at the second UV- light irradiation station (123) is performed before the electron beam irradiation.

8. A sterilization arrangement (120) for, within a packaging machine (100) configured to fill packages (104) with a food product, sterilization of a web (102) of packaging material comprising 3D structures (103), the sterilization arrangement (120) comprising the following stations: a first UV-light irradiation station (122) configured to subject the 3D structures (103) in the web (102) for UV-light irradiation; and an electron beam irradiation station (124) configured to subject both the 3D structures (103) in the web (102) and a surface of the web (102) for electron beam irradiation.

9. The sterilization arrangement (102) according to claim 8, wherein the first UV-light irradiation station (122) is arranged before the electron beam irradiation station (124) in a feeding direction of the web (102) of packaging material.

10. The sterilization arrangement (120) according to claim 8 or 9, wherein the first UV- light irradiation station (122) comprises a second plurality of UV-LED units (210) arranged to illuminate the 3D structures (103) from different angles relative the surface of the web of packaging material.

11. The sterilization arrangement according to any one of claims 8-10, further comprising an additional station in the form of a second UV-light irradiation station(123) configured to subject the surface of the web (102) of packaging material for UV- light irradiation.

12. The sterilization arrangement (120) according to claim 11, wherein the second UV- light irradiation station (123) is arranged before the electron beam irradiation station(124) in a feeding direction of the web (102) of packaging material.2787-2482-2032, v.

213. A packaging machine (100) configured to fill packages (104) with a food product, the packaging machine (100) comprising: a sterilization arrangement (120) according to any one of claims 8-12, wherein the stations of the sterilization arrangement (120) are stationary stations; and a feed unit (110) configured to continuously feed the web (102) of packaging material through the stations of the sterilization arrangement (120).

14. The packaging machine (100) according to claim 13, wherein the sterilization arrangement (120) comprises a control circuitry configured to turn the first UV-light irradiation station (122) on while a 3D structure (103) in the web (102) passes through the first UV-light irradiation station (122) and turn the first UV-light irradiation station (122) off while no 3D structure (103) in the web (102) passes through the first UV-light irradiation station (122).

15. The packaging machine (100) according to claim 14, wherein the first UV-light irradiation station (122) comprises a first plurality of UV-LED units (210) arranged along a feeding direction of the web (102), wherein the control circuitry is configured to individually turn the first plurality of UV-LED units (210) on / off as a 3D structure (103) in the web (102) passes through the first UV-light irradiation station (122).2787-2482-2032, v. 2

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