JP2009539718A - Package sterilization method - Google Patents

Abstract

  The present invention relates to a method for sterilizing a package (10) molded at least in part in a packaging machine. The method divides at least the inner surface of the package (10) into at least two area portions to be sterilized, and one electron beam sterilization device (each of the two area portions is adapted to the characteristics of the respective area portion). 18) and between the package (10) and each of the two electron beam sterilizers (18), the sterilizer (18) sterilizes the respective one of the two area portions. Sterilizing two of the at least two area portions by providing respective relative movements adapted to

Description

  The present invention relates to a method for sterilizing a package which is at least partially molded in a packaging machine.

  In the food packaging industry, packages formed from packaging material blanks comprising different paper layers or paperboard layers, for example polymer liquid barriers, for example aluminum thin film gas barriers, have been used for many years. Blanks are pre-formed from a material web and are often provided with a crease pattern that facilitates molding and folding of the package. The web is cut into pieces that are individually sized and shaped to make one package. After cutting, each piece is folded to form a flat tubular blank with the longitudinal edges overlapped with each other. The longitudinal edges are then sealed by any suitable conventional sealing technique such as heat sealing. The result is a flat tubular blank. Blank formation from the web itself is well known and will not be described in further detail.

  In a packaging machine, a blank is raised and formed into a tube, which has a cross section that is usually square or rectangular, depending on the type of package. Thereafter, one end of the tube can be laterally sealed to form the bottom (or top) of the package, and the package is ready for filling with food, such as a beverage. This type of package is sold by the applicant under the name Tetra Rex.

  There is also a carton-bottle package made of a tubular sleeve of packaging material as described above and a plastic top that is closely attached to the sleeve. This top is either pre-made outside the packaging machine or injection molded directly on the sleeve inside the packaging machine. The top is equipped with a lid device. These types of packages can be filled before the bottom end of the sleeve is laterally sealed and final folded to form the bottom. These packages can also be filled through the spout of the lid device. Similar packages are sold by the applicant under the names Tetra Aptiva® and Tetra Top®.

  A partially molded package with an opening at one end for filling but the other end sealed to form the bottom or top is generally referred to as a filling ready package (RTF package). Hereinafter, this pre-filled package is represented by the word “package”.

  In order to extend the life of the packaged product, it is conventionally known to sterilize the package before the filling operation. Different sterilization levels are selected depending on how long a lifetime is desired and depending on whether the transport and storage is at refrigeration or atmospheric temperature. However, the term sterilization includes herein any level of cleaning and microbial killing operations.

  One sterilization method is to irradiate the interior of the package with electrons emitted from an electron beam unit. This method and an apparatus for carrying out this method are described in International Patent Publication WO2005 / 002973 by the present applicant, and the description is incorporated herein by reference.

A typical system for sterilizing packages by electron beam technology includes an electron beam sterilizer that emits an electron beam along the beam path. The device is coupled to an electron beam generator, which is connected to a high voltage power source and a filament current source. The latter converts the power from the high voltage power source into an input voltage suitable for the generator filament. The filament can be housed in a vacuum chamber. In operation, electrons e ⁻ from the filament are emitted toward the target A along the electron beam path. The grid around the filament is used to diffuse the electron beam into a more uniform beam and to focus the electron beam towards the target. Beam absorbers and magnetic fields can also be used to shape the electron beam. Electrons are emitted from the sterilizer through an electron exit window.

  However, during sterilization of the package, it has been found difficult to achieve a uniform electron beam dose across the entire package with a single electron beam sterilizer. This is because the shape of each physical part of the package is different. Corners, openings, lid device parts, bottle tops, bottoms, flat wall parts, etc. require sufficient sterilization, but are preferably not exposed excessively to irradiation. There is also a cost problem. It is preferable not to use excessive energy more than necessary.

  Accordingly, one object of the present invention is to provide an electron beam irradiation that allows a substantially uniform dose to all parts of the package within the packaging machine, i.e. the package to be exposed to a predetermined electron beam dose. It is to provide a method for sterilizing at least a partly molded package by electron beam irradiation which can achieve a predetermined sterilization level in all parts.

  The purpose is to divide at least the inner surface of the package into at least two area parts to be sterilized, and each of the two area parts comprises one electron beam sterilizer adapted to the characteristics of the respective area part, At least two areas between the package and each of the two electron beam sterilizers are provided with respective relative movements adapted to sterilize the respective one of the two area parts by the sterilizer. It has been accomplished by a method comprising sterilizing two of the parts, and transferring the package to a filling station that fills the package with the product through an opening and then sealing the package.

  In this method, one suitable sterilizer can be selected for each area portion to be sterilized. In other words, the shape of each sterilizer can be adapted to the features such as the shape and dimensions of the corresponding surface portions, and sterilization can be performed in an optimum state. As well as adapting to the shape of the sterilizer, the relative movement between the package and the sterilizer is also adapted. Even if the sterilizer is adapted to one area portion, some area portions may require a longer exposure time or slower movement of the electron beam than others are sufficiently sterilized. The combination of the adapted sterilization device and the adapted relative movement makes it possible to perform the sterilization of the package very effectively with regard to energy consumption and consumption time. This combination also makes it possible to achieve a cost-effective sterilization system.

  In a presently preferred embodiment of the invention, the method further comprises the step of sterilizing the associated area portion by providing each area portion with an electron beam sterilization device each adapted to the characteristics of one area portion. . The package can be divided into several areas, and the packaging machine will have the same number of sterilizers. In this way, very careful package irradiation can be achieved.

  In another embodiment of the present invention, the method includes dividing at least the inner surface of the package so that the formed area portions at least slightly overlap each other. By doing this, it can be ensured that at least a part of the package is not left unsterilized. In some cases, one area portion will overlap each other more or less completely.

  Another embodiment includes providing one sterilization device coupled to the electron beam generator to sterilize one area portion. The electron beam generator can be housed in a sterilizer to form a small unit that is easy to move and handle.

  Yet another embodiment includes providing a plurality of sterilizers to sterilize multiple area portions, some of which are coupled to the same electron beam generator. If appropriate, multiple sterilizers are connected to the same electron beam generator. This saves space and is more cost effective than having one electron beam generator per sterilizer.

  In yet another embodiment, the method includes providing a plurality of sterilizers all connected to the same electron beam generator to sterilize the plurality of area portions.

  In an additional embodiment, the method includes a plurality of sterilizers each comprising at least one electron exit window for emitting at least a portion of the electron beam generated by the at least one electron beam generator. Including sterilizing a plurality of area portions. The electron beam exit window is used to emit electrons and is an important parameter for adapting the sterilizer to an area portion. Different window shapes give different illumination characteristics.

  In yet another embodiment, the method includes providing at least first and second processing stations in a sterilization chamber, each having at least one electron beam sterilizer disposed therein, and disposing a package in the first station, Sterilizing at least a first area portion of the interior of the package with an electron beam sterilizer in the first station; and disposing the package in the second station, and using the electron beam sterilizer in the second station. Sterilizing at least the second area portion inside.

  One embodiment includes placing the package in at least one additional station disposed in the sterilization chamber and having at least one electron beam sterilizer, and at least one area portion including a portion of the package outer surface near the opening. Further sterilizing. In this method, recontamination from the outside of the package to the inside of the package can be prevented.

  Ancillary embodiments include sterilizing two or more packages at each station. In this way, the capacity of the packaging machine can be increased.

  In the following, the presently preferred embodiment of the present invention will be described in greater detail with reference to the accompanying drawings, in which like reference numerals are used to designate like parts.

  For simplicity, similar features in the various embodiments are designated with the same reference numerals.

  FIG. 1 shows an embodiment of two partially molded packages indicated by reference numeral 10 which are sterilized by the method of the present invention. As explained at the beginning, a partially molded package typically has one end 12 closed and an opening 14 at the other end. The closed end 12 is formed as the bottom or top, and the opening 14 can form the open end of the package sleeve, which is then sealed or surrounded by the neck of the lid device The spout can be provided with a cap or the like thereafter. The package embodiment on the right side of the figure has a sealed bottom and a top opening in the shape of a spout surrounded by a threaded neck of the lid device. The package example on the left has an opening (bottom) and the other end is provided with a top and a sealed lid device.

  Hereinafter, the concept of the electron beam generator 16, the electron beam sterilizer 18, and the electron beam sterilizer will be briefly described with reference to FIG. The electron beam generator 16 includes means for emitting an electron beam 20 along the radiation path, which means is coupled to a sterilizer 18 that distributes the beam 20 toward the package 10.

  Typically, the electron beam generator 16 is connected to a high voltage power supply 22 that is suitable for providing a voltage sufficient to drive the electron beam generator 16 of the desired application. The electron beam generator 16 is also connected to a filament current source 24 which converts the voltage from the high voltage power source 22 into a suitable input voltage for the filament 26 of the generator 16. In addition, the high voltage power supply 22 includes a grid controller 28 that controls the grid 30 of the electron beam generator 16.

  The electron beam generator used for sterilization of the package generally means a bottom voltage electron beam unit, which unit typically has a voltage of less than 300 kV. In the disclosed design, the acceleration voltage is within 70-90 kV. This voltage produces a kinetic (movement) energy of approximately 70-90 keV for each electron.

The filament 26 can be made of tungsten and can be housed in the vacuum chamber 32. Typically, the vacuum chamber can be kept secret. In operation, current is passed through the filament 26 and the electrical resistance of the filament heats the filament to a temperature of approximately 2000 ° C. This heating causes the filament 26 to emit a cloud of electrons e ⁻ . Those electrons are emitted along the electron beam path toward a target area portion, in this example, one area portion inside the package 10. The grid 30 disposed between the filament and the electron beam exit window has a large number of openings, and diffuses the electron beam 20 so as to make it a more uniform beam so that the electron beam 20 reaches a target area portion. Used to focus towards.

  In the illustrated embodiment, the electron beam generating means is housed in an electron beam sterilizer 18. The sterilizer 18 includes a vacuum chamber, which in this example is the same as the vacuum chamber 32 of the electron beam generator 16. The sterilizer 18 further includes an electronic exit window 34. The window 34 can be made of a metal foil such as titanium and has a thickness of about 4 to 12 μm. A support net made of aluminum or copper supports the foil from the inside of the electron beam generator 16. Electrons are emitted from the vacuum chamber 32 through the exit window 34.

  In this embodiment, the sterilizer 18 with the electron beam generator 16 therein has a substantially circular cross-sectional cylinder shape and the exit window 34 is located within the first end of the cylinder.

  In the alternative embodiment shown in FIG. 3, the electron beam generator 16 and the sterilizer 18 are of course coupled, but only the sterilizer 18 cooperates with the package 10, i.e. during the irradiation, the sterilizer 18. Are positioned or moved at least partially within or around the package 10. The vacuum chambers (not visible from the outside) are in communication with each other, and the sterilizer 18 serves as an extension or nozzle for the electron beam generator 16, i.e. used to reach the package part to be sterilized.

  A support (not shown) is provided to support the target or package 10 within the target area portion. This support can be, for example, a normal carrier of a conveyor that transports the package 10 through the sterilization chamber. While sterilizing a package 10 similar to the package on the left side of FIG. 1, the package 10 is placed upside down on the support (top is located on the lower side).

  Further, relative movement is provided between the package 10 and the sterilizer 18 during sterilization. The sterilizer 18 is lowered into or around the package 10, the package 10 is raised around the sterilizer 18, or each is moved toward each other. To achieve this, the support is either stationary or made movable in the approaching and separating directions with respect to the sterilizer 18.

  Within the second end of the sterilizer 18 that mates with the electron beam generator 16, means (not shown) are provided for attachment to preferred peripheral members. For example, such means may be means for suspending the sterilizer or electron beam generator from the inner top wall of the sterilization chamber with an electron beam exit window 34 directed downward toward the package 10. Alternatively, the second end comprises means (not shown) for providing a relative movement (see arrow) between the package 10 and the electron beam generator 16 so that the device 18 can be used for package processing. Is positioned or imparted to be positioned at least partially within or around the package 10.

  The relative movement can be given in many different ways. For example, it may include slowly lowering the sterilizer into the package, then stopping for a short time, and then quickly raising it out of the package. Alternatively, relative movement can include lowering and raising without stopping. In yet another alternative, the descent and ascent are very rapid, but are stopped for a short time many times along the way.

  FIG. 4 shows a sterilization chamber 36 through which the package 10 is transported in the direction of the horizontal arrow and sterilized. It is known in the art to sterilize the package prior to the filling operation in order to extend the life of the packaged product. Different sterilization levels can be chosen depending on how long a lifetime is desired and whether delivery and storage is done at refrigerated or atmospheric temperatures. With respect to atmospheric temperature, the level expressed as sterilization from a commercial standpoint is preferred. However, the term sterilization includes herein any level of cleaning and microbial kill.

  This figure also shows the filling device 38. The package 10 is sterilized in the sterilization chamber 36 and then sent to the filling device 38. The filling device 38 comprises at least one filling station 40 for filling the product through the opening of the package 10. As already explained, this opening may be the end of the package that is still open, or it may be a part of the lid device that is not yet sealed, for example a spout surrounded by a neck.

  The filling station 40 can form part of any suitable type of package filling system. For example, a linear filling system or a rotary filling system can be used. The filling system will not be described in further detail.

  The sterilization method according to the present invention includes the step of dividing at least the inner surface of the package 10 into at least two area portions to be sterilized. Each area portion is sterilized by a respective sterilizer 18. By using multiple sterilization devices 18 and processing one area portion of the package 10 at a time, each sterilization device 18 can be adapted to features such as the geometry of the area portion to be sterilized. This is adapted to form an electron beam 20 or part thereof in a beam path that can be substantially optimized for the area of each sterilizer 18 that is irradiated, i.e. suitable for the particular area of sterilization. Means that. For this purpose, the sterilization chamber 36 comprises at least two electron beam sterilizers 18 for at least two area portions.

  An area portion is defined herein as one or more package surfaces to which a sterilizer is adapted. The division into a plurality of area portions is performed by any appropriate method. For example, one area portion can be in the shape of the bottom portion of the package. The other area portion may have a shape of the inner surface of the cylindrical body of the package. Still other area portions can be in the shape of a lid device or package top. However, this division need not be bounded by the physical part of the package. For example, one area portion can be formed by a part of the bottom part and a part of the lower part of the inner surface of the cylindrical body. Other area portions can be formed, for example, at the top of the lid device and package. Still other parts can be formed, for example, on the cylindrical surface and the bottom of the package. The portions and surfaces of the package included in one area portion need not be continuous or connected, and may be completely separated from each other. The number of different sterilizers required depends on the number of different area portions present in the package.

  These area portions are at least slightly overlapped with each other to ensure that no part of the package is under-exposed. In some examples, one area portion is somewhat overlapped with each other. A sterilization device adapted to sterilize the top area of the package is described below. However, the amount of radiation covering the area of the lid device at the top needs to be increased by other sterilization devices so that sufficient sterilization is performed. Therefore, the second area portion is completely overlapped with the first area portion.

  Each sterilizer 18 is shaped so that it can optimally irradiate the area portion assigned to irradiate. The characteristics of the electron beam sterilizer 18 that can be modified to obtain different illumination characteristics required for different areas include, for example, the shape and dimensions of the sterilizer 18, the number of electron exit windows 34 and their arrangement and shape. It is. To further change the nature of the electron beam 20, the filament 26 and the control grid 30 can be modified.

  Furthermore, the relative movement between the package 10 and the sterilizer 18 is schematically shown in FIG. 4 by a vertically oriented arrow, but is determined so that optimum irradiation is performed with the sterilizer 18. .

  In the exemplary embodiment shown in FIG. 4, the sterilization chamber 36 comprises first and second processing stations I, II. After this, an additional, in this case a third station III, is also provided in the sterilization chamber 36.

  The first station I is a station for sterilizing the first area portion of the package 10, and the second station II is a station for sterilizing the second area portion of the package 10. The stations I and II each include one electron beam sterilizer 18 for sterilizing the respective area portion.

  The sterilizer 18 in the station of FIG. 4 can be a separate sterilizer, each connected to an electron beam generator. Therefore, the electron beam generator 16 can be accommodated in the vacuum chamber 32 of the sterilizer 18. Instead, the sterilizer 18 is connected to a common electron beam generator 16 as shown in FIG. However, it should be noted that for the sake of clarity, the station of FIG. 3 is shown with other sterilization devices other than the sterilization device shown in FIG.

  In the embodiment of FIG. 4, the first station I is used for sterilization of the area including the top inner surface and the inner surface of the closed lid device. The second station II is used for sterilization of the area portion having the shape of the inner surface of the package cylinder.

  The sterilizer 18 of the first station I will be described in further detail hereinafter with reference to FIG. 6a. The sterilizer includes a flat exit window that forms a wide circular beam suitable for irradiating, for example, an area of the dome-shaped package top. The sterilizer 18 of the second station II, which will be described in more detail below with reference to FIG. 6b, is arranged to form a circular beam suitable for use, for example, for irradiation of the circular cylindrical surface of the package 10. A number of electron beam exit windows are provided.

  As already mentioned, the sterilization chamber 36 also includes an additional third station III that sterilizes at least a portion of the package inner surface near the opening prior to filling the package 10. This sterilizer 18 will be described in further detail hereinafter with reference to FIG. 6f.

  The package 10 arranged upside down enters the sterilization chamber 36 on the left side of FIG. 4 and is sent to the first station I. Within the first station I, the first sterilizer 18 is lowered a suitable distance into the package 10 from the illustrated raised position and irradiates the first area portion of the package 10. This area is exposed to the irradiation beam for a predetermined time. This time is adjusted by the relative movement between the package 10 and the sterilizer 18. After a predetermined time has elapsed, the sterilizer 18 is raised again, and the package 10 is sent to the second station II, where a second area portion is irradiated by the sterilizer 18 in the station II. The sterilizer 18 is lowered and raised in the same way. The relative movement, and thus the irradiation exposure time, can be the same as or different from the case of the first station.

  After the second station II, the package is sent to the third station III, where at least part of the shaped area of the outer surface of the package 10 near the open end is sterilized to prevent recontamination of the inner surface of the package. To do. Similarly, the sterilizer 18 is lowered around the open end 12 of the package 10 and sterilized for a predetermined time. The sterilizer 18 is then raised and the sterilization of the package 10 is finished. This prepares the package 10 for advancement to the next chamber, the filling device 38 for filling. After filling, the package 10 is sealed. In this example, the open end 12 of the package sleeve is squeezed and the package 10 is sealed laterally with heat in the usual manner.

  Referring to the package on the right side of FIG. 1, in another embodiment in which the package is sterilized and filled through the spout at the top of the package, the sealing process includes a membrane on the neck around the spout and / or, for example, a screw cap Including a cap.

  FIG. 5 shows a second embodiment of the sterilization chamber 36 of FIG. The second embodiment includes a plurality of processing stations, each processing station including one or more similar electron beam sterilizers 18. In this way, it is possible to sterilize one or more packages at each station simultaneously. The sterilizer 18 is preferably connectable to a common electron generator as shown in FIG. This packaging machine requires a double indexing of the package, ie the package 10 located in the first sterilizer 18 of the first station I is sent directly to the first sterilizer 18 of the second station II.

  In the following, a number of sterilizers 18 having different electron beam characteristics, for example by having various shapes and window structures, will be described.

  The first sterilizer 18 shown in FIG. 6a has a circular cylinder 42 with dimensions corresponding to the dimensions of the package having a circular cross section. The cylinder 42 surrounds the electron beam generator 44 and the generator filament and grid are shown schematically in the figure. An electron beam exit window 46 is provided inside one end of the cylindrical body in the axial direction. In this embodiment, the window 46 has a flat circular shape with dimensions that are substantially equal to the circular end of the cylinder 42. The filament may be ring-shaped or linear. The grid diffuses the electron beam 20 into a more uniform beam and directs the electron beam 20 to the exit window 46 so that electrons are emitted substantially through the entire surface of the window or through selected portions. It is made to concentrate towards. This structure is suitable for use, for example, for illuminating a flat bottom shaped area portion of a package. The sterilizer 18 is then lowered into the package from the top of the package opening or the package is raised around the sterilizer. Alternatively, the sterilizer 18 can be used to irradiate an area portion that is cylindrically symmetric or shaped like a dome-shaped package top. The sterilizer 18 is then lowered into the package from the bottom open end of the package or the package is raised around the sterilizer 18. Instead, an area portion is formed on both the bottom of the package and the inner surface of the cylindrical body. In this way, relative movement includes both a gradual lowering of the sterilizer and a brief stop near the bottom of the package.

  The second sterilization device 18 shown in FIG. 6b is substantially similar to the first sterilization device, but the cylindrical body 42 is provided with a thin circular nozzle 50. The electron beam exit window 46 is disposed in one end in the axial direction and has a flat circular shape. The sterilizer 18 can be used to illuminate a package, such as a bottle having a narrow open end, requiring the sterilizer to be lowered and raised through the open end of the package. Similar shapes can be used to enhance the electron beam 20 in specific area portions, such as aperture devices, lid devices, and other irregularly shaped small area portions. It should be understood that the nozzle shape can be other than circular, for example, square, rectangular, triangular, elliptical, or any other different shape.

  The third sterilization device 18 shown in FIG. 6 c is substantially similar in basic design to the first sterilization device, but with a cone so that the dose is increased toward each exit window 46 to form a wide circular beam 20. A number of exit windows 46 arranged in a shape are provided. If four windows 46 are arranged as shown, the sterilizer 18 is suitable for irradiation of a symmetrical square package with corners. In order to give a uniform dose to the inner surface of the package, the window is preferably arranged so as to face the corner. This shape is also suitable for irradiation of the inner surface of the circular cylinder. Compared to the shape of the first sterilizer, this shape can be made faster when the cylindrical surface of the cylindrical package is sterilized. This is because the average length of the electron movement path is shortened.

  The fourth sterilization device 18 shown in FIG. 6d is substantially similar to the conventional sterilization device and also includes a plurality of windows. The window 46 is disposed on the cylindrical surface of the circular cylindrical body 42. A window 46 can be provided at the end of the body. The formed electron beam 20 extends downward and laterally, and the sterilizer 18 is suitable for use in irradiating an area including the substantially flat package bottom and the inner cylindrical surface of the package.

  The fifth sterilizer 18 shown in FIG. 6e is substantially similar to the first sterilizer, but includes an axial square and flat electron beam exit window 46. FIG. The size of the exit window 46 is larger than the cross section of the circular body 42. Thus, the end of the exit window 46 is provided with a flange 52. The end of the flange 52 connected to the circular cylinder 42 is circular, and the end with the exit window 46 is square. The grid is adapted to focus the electron beam 20 towards the exit window 46 such that the electron beam 20 is emitted through substantially the entire surface or selected portion of the exit window 46. This structure is suitable for use in illuminating an area portion such as the bottom of the package square or the inner surface of the package square. Alternatively, the window 46 has a cross-sectional shape suitable for irradiation in other shapes, such as an oval or package shape.

  The sixth sterilization apparatus 18 shown in FIG. 6f is substantially similar to the conventional sterilization apparatus, but has a difference that it can be suitably used for irradiation of a shape that is not flat. A funnel-shaped portion 54 is provided at one end of the circular cylindrical body 42. The width of the funnel-shaped portion 54 increases in the direction away from the cylindrical body 42. A plurality of electron exit windows 46 are arranged in a conical shape 56 inside the funnel-shaped portion 54. This allows the exit window 46 to move closer to the package surface, even when the surface has a bulging shape or has a protruding lid device. The area of the outer surface of the bottle top of the package can be illuminated by this device. Furthermore, the cup can also be irradiated.

  In the method of the present invention, for example, at least first and second sterilizers can be used to sterilize a package similar to the package on the left side of FIG. The first sterilizer sterilizes the area portion including the top surface and the second sterilizer provides additional enhancement to the shaped area portion of the inner surface of the lid device. A sixth sterilization device can be added to sterilize an area portion including a portion of the package outer surface near the opening 14. Relative motion is applied to each area portion.

  Although the invention has been described in terms of the presently preferred embodiments, it should be understood that various changes and modifications can be made without departing from the scope of the invention as set forth in the claims.

  In the accompanying embodiment, two processing stations are combined. For example, the first and second stations are provided at the same location to sterilize the package initially with the first station electron beam sterilizer and then with the second station electron beam sterilizer. The package is not sent anywhere during both irradiations; instead, both sterilizers are shifted once or provided together during package shutdown. In the embodiment of FIG. 4, in order to actually form two stations, for example, the first station can be provided with two sterilizers. The first sterilization device is designed to sterilize the area portion of the inner surface of the lid device, and the second sterilization device is designed to sterilize the top-shaped area portion, that is, the area portion around the lid device. The Similarly, for example, a second station and an additional third station can be combined. Therefore, for example, the other sterilizer can be arranged around one sterilizer.

  Further, the package is described as having an inner cylindrical surface, and the drawings show that the package has a circular cross section. However, it should be understood that the term “package inner cylinder surface” should be interpreted as an inner wall surface or a plurality of package wall surfaces regardless of the cross-sectional shape of the package. The package cross-section can have almost any shape, such as a circle, square, rectangle, ellipse, triangle, rectangle, or other shape.

2 schematically shows two partially molded packages to be sterilized by the method of the present invention. A typical system for performing this method is schematically shown. 1 schematically shows the appearance of a number of sterilizers connected to a common electron beam generator. 1 schematically shows the appearance of a partial cross section of a sterilization chamber and a filling chamber comprising three processing stations each equipped with one sterilizer. Fig. 5 schematically shows an appearance similar to Fig. 4 but with two sterilizers at each processing station. 6a to 6f schematically show examples of different sterilizers, each sterilizer being viewed from the outside, a partially sectioned view, and an axial end with an exit window structure It is shown schematically in the view seen from.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Package 12 Closed end part 14 Opening 16 Electron beam generator 18 Electron beam sterilizer 20 Electron beam 22 High voltage power supply 24 Filament current supply source 26 Filament 28 Grid control device 30 Grid 34 Electron exit window 36 Sterilization room 38 Filling device 40 Filling Station 42 Tube 44 Electron beam generator 46 Exit window 50 Nozzle 52 Flange 54 Funnel-shaped portion 56 Conical

Claims (10)

A method of sterilizing at least a part of a package (10) designed in a packaging machine by electron beam irradiation,
Dividing at least the inner surface of the package (10) into at least two area portions to be sterilized;
Each of the two area portions is provided with one electron beam sterilizer (18) adapted to the characteristics of the respective area portion, and between the package (10) and each of the two electron beam sterilizers (18). Sterilizing two of the at least two area portions by providing respective relative movements adapted to sterilize each related one of the two area portions by the sterilization device (18);
Sealing the package (10) after transferring the package (10) to a filling station (40) for filling the package (10) with the product through the opening (14).   2. For each additional area portion, including the step of sterilizing each area portion by providing each area portion with one electron beam sterilization device (18) adapted to the characteristics of each area portion. The method described in.   3. A method according to claim 1 and claim 2, comprising the step of dividing at least the inner surface of the package (10) such that the formed area portions at least partially overlap each other.   4. A method as claimed in any one of the preceding claims, comprising the step of providing a sterilization device (18) connected to one electron beam generator (16) for sterilization of the area portion.   4. The method according to claim 1, comprising providing several sterilization devices (18) connected to the same electron beam generator (16) for sterilization of the area portion. Method.   4. The method according to claim 1, further comprising providing a plurality of sterilization devices (18) all connected to the same electron beam generator (16) for sterilization of the area portion. 5. Way.   By the sterilization device (18), each sterilization of the area portion is provided with at least one electron exit window 46 for emitting at least part of the electron beam (20) generated by the at least one electron beam generator (16). The method according to any one of claims 1 to 6, wherein the method is performed. Providing in the sterilization chamber (36) at least first and second processing stations (I, II), each disposed with at least one electron beam sterilizer (18);
Disposing the package (10) in the first station (I), and sterilizing at least the first area inside the package (10) with the electron beam sterilizer (18) in the first station (I); When,
Disposing the package (10) in the second station (II) and sterilizing at least the second area inside the package (10) with the electron beam sterilizer (18) in the second station (II); The method according to any one of claims 1 to 7, further comprising:   Placing the package (10) in at least one additional station (III) disposed in the sterilization chamber (36) and provided with at least one electron beam sterilizer (18); 9. The method of claim 8, further comprising: sterilizing at least one area portion including a portion of the outer surface of the package (10). The method according to claim 8 and 9, further comprising the step of sterilizing two or more packages (10) at each station.

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