Control method for electron beam sterilizing device and device performing said method

An electron beam sterilizing device for sterilizing packages or a packaging laminate for forming packages, the electron beam sterilizing device comprising:

• a housing in which is located a vacuum chamber, the housing comprising an exit window;
• a filament positioned in the vacuum chamber of the housing;
• a power supply connected to the filament to drive current through the filament and generate electrons to sterilize the packages or the packaging laminate;
• a voltage supply configured to create a voltage potential between the filament and the exit window to accelerate the electrons generated by the filament, with the accelerated electrons passing out of the housing through the exit window to effect sterilization of the packages or the packaging laminate;
• and
• control means for controlling operation of the electron beam sterilizing device to operate the electron beam sterilizing device in at least three operational states, the three operational states comprising:
• a first state in which drive current is not delivered to the filament from the power supply;
• a second state in which drive current is delivered to the filament from the power source to maintain the filament at a temperature above an emission temperature at which the filament generates electrons;
• and
• a third state, between the first state and the second state, in which drive current is delivered to the filament from the power source to maintain the filament at a temperature below the emission temperature;
• wherein the control means controls the electron beam sterilizing device to operate in the third state during stand still periods.