Device and method for sterilizing packaging containers by electron beam

Abstract

A sterilization device for sterilizing open packaging containers with electron beams includes a chamber having at least one electron beam emitter adapted for sterilization of at least an interior surface of the packaging container through an opening of the packaging container, and a sensor configured to measure a dose parameter of the at least one electron beam emitter. A method of sterilizing open packaging containers with electron beams includes sterilizing at least an interior of the packaging container, through an opening of the packaging container, with an electron beam emitter arranged in a chamber, and measuring a dose parameter of the at least one electron beam emitter by a sensor.

1 . A sterilization device for sterilizing open packaging containers with electron beams, said sterilization device comprising:
 a chamber comprising at least one electron beam emitter adapted for sterilization of at least an interior surface of the packaging container through an opening of the packaging container; and   a sensor configured to measure a dose parameter of the at least one electron beam emitter.   
     
     
         2 . The sterilization device of  claim 1 , wherein
 the electron beam emitter and the packaging container are adapted to perform a mutual relative movement, during which movement a portion of the electron beam emitter is temporarily inserted through the opening of the packaging container, such that interior sterilization of the packaging container takes place, and   a dose rate of the at least one electron beam emitter is adjusted based on speed of the mutual relative movement and the measured dose parameter.   
     
     
         3 . The sterilization device of  claim 2 , wherein the mutual relative movement is such that the packaging container is moved with a first velocity from a first position to a second position, and with a second velocity from the second position back to the first position, said second velocity being lower than the first velocity. 
     
     
         4 . The sterilization device of  claim 1 , further comprising
 at least one second electron beam emitter adapted for sterilization of at least a portion of an exterior surface of said packaging container, wherein   said chamber has an entry region towards a second chamber, through which entry region a packaging container portion, comprising said opening, is adapted to be passed for entrance into the second chamber,   said at least one second electron beam emitter being arranged such that its electron exit window is at least substantially facing said entry region, said second electron beam emitter thereby being adapted to sterilize at least any exterior surface of the packaging container portion being passed through the entry region, and   said at least one electron beam emitter being arranged to sterilize the interior surface before or at the same time as said packaging container portion is entered into the second chamber.   
     
     
         5 . The sterilization device of  claim 4 , wherein the at least one second electron beam emitter is positioned such that an electron cloud emitted from the at least one second electron beam emitter, during operation of the sterilization device, is adapted to form an irradiation barrier at least covering the entry region, and wherein an electron cloud emitted from the at least one electron beam emitter is adapted to temporarily meet and partly overlap the electron cloud emitted from the at least one second electron beam emitter, said electron clouds together forming a combined electron cloud, and wherein the opening of the packaging container portion is at least temporarily positioned within the combined cloud. 
     
     
         6 . The sterilization device of  claim 4 , wherein the electron cloud of the at least one second electron beam emitter is elongate and defines the entry region, and wherein the entry region is being inclined in relation to a feeding direction of the packaging containers and in relation to a longitudinal direction of the packaging containers, such that a greater exterior surface area of the packaging containers passing through the entry region are sterilized. 
     
     
         7 . The sterilization device of  claim 6 , wherein the at least one second electron beam emitter is arranged such that a longitudinal axis thereof and of the electron exit window is inclined in relation to a horizontal direction, and that the packaging container is moved along said horizontal direction, with a longitudinal center axis of the packaging container directed perpendicular to the horizontal direction, in such a way that a portion of the packaging container, comprising the opening, is gradually leaving the entry region and entering the second chamber. 
     
     
         8 . The sterilization device of  claim 4 , wherein the second chamber has a bottom wall provided with a slot, and wherein the packaging containers are transported in the second chamber along the slot having the sterilized packaging container portion positioned above said bottom wall, and the rest of the packaging container positioned below said bottom wall, and wherein a sterile gas flow is provided, during operation, from the second chamber and in a direction towards the slot. 
     
     
         9 . The sterilization device of  claim 4 , wherein the at least one second electron beam emitter comprises two second electron beam emitters, arranged opposite each other with their electron exit windows facing each other and the entry region, in such a way that the packaging containers can pass in between them. 
     
     
         10 . The sterilization device of  claim 4 , further comprising a packaging container conveying system comprising a packaging container conveyor comprising holders adapted to hold the packaging containers, and wherein said packaging container conveyor is used for transporting packaging containers both in the chamber, the entry region and the second chamber. 
     
     
         11 . The sterilization device of  claim 10 , wherein the packaging container conveying system comprises a rotatable guide wheel adapted to cooperate with a carrier wheel carrying a plurality of said electron beam emitters and the packaging container conveyor such that each packaging container is adapted to be aligned with a corresponding one of said plurality of said electron beam emitters, and which guide wheel is provided with packaging container grippers adapted to displace each packaging container in relation to the electron beam emitter with which the packaging container is aligned between a first position in which the packaging container and the electron beam emitter with which the packaging container is aligned are not engaged with each other and a second position in which the electron beam emitter with which the packaging container is aligned is fully inserted into the packaging container. 
     
     
         12 . The sterilization device of  claim 11 , wherein the packaging container grippers are adapted to lift each packaging container from a corresponding one of said holders to the second position, in which the packaging container is released from said corresponding one of said holders, and then to retract the packaging container to the first position and back into said corresponding one of said holders. 
     
     
         13 . The sterilization device of  claim 1 , wherein the sensor is disposed in front of an electron exit window of the at least one electron beam emitter as the at least one electron beam emitter passes the sensor. 
     
     
         14 . A method of sterilizing open packaging containers with electron beams, said method comprising
 sterilizing at least an interior of the packaging container, through an opening of the packaging container, with an electron beam emitter arranged in a chamber; and   measuring a dose parameter of the at least one electron beam emitter by a sensor.   
     
     
         15 . The method of  claim 14 , further comprising
 performing mutual relative movement between the electron beam emitter and the packaging container during which movement the sterilizing of the interior of the packaging container takes place, and during which movement a portion of the electron beam emitter is temporarily inserted through the opening of the packaging container; and   adjusting a dose rate of the at least one electron beam emitter based on speed of the mutual relative movement and the measured dose parameter.   
     
     
         16 . The method of  claim 15 , wherein the mutual relative movement is performed such that the packaging container is moved with a first velocity from a first position to a second position, and with a second velocity from the second position back to the first position, said second velocity being lower than the first velocity. 
     
     
         17 . The method of  claim 14 , further comprising sterilizing at least a portion of an exterior of the packaging container with at least one second electron beam emitter, wherein
 said at least one second electron beam emitter is arranged such that its electron exit window is at least substantially facing an entry region, said entry region forming an entrance to a second chamber from the chamber,   the sterilizing of at least a portion of the exterior of the packaging container is performed in said entry region by passing a portion of the packaging container, said portion comprising said opening, through the entry region, and   the sterilizing of the interior of the packaging container is performed before or at the same time as said packaging container portion is entered into the second chamber.   
     
     
         18 . The method of  claim 17 , further comprising forming an irradiation barrier at least covering the entry region during operation of the sterilizing device, said irradiation barrier being formed by an electron cloud emitted from the at least one second electron beam emitter, and forming a combined electron cloud by temporarily letting an electron cloud emitted from the at least one electron beam emitter meet and partly overlap the electron cloud emitted from the at least one second electron beam emitter, and temporarily positioning the opening of the packaging container within the combined electron cloud. 
     
     
         19 . The method of  claim 17 , wherein the sterilizing of at least the interior of the packaging container and the sterilizing of at least a portion of the exterior of the packaging container are performed in a filling machine, and further comprising filling content into the sterilized packaging container, and sealing the opening after filling. 
     
     
         20 . The method of  claim 14 , further comprising passing the at least one electron beam transmitter by the sensor such the sensor is disposed in front of an electron exit window of the at least one electron beam emitter.