Method of opening an outer bag of a pre-filled double-bag and an opening device therefore

An opening system for opening an outer bag of a pre-filled double-bag comprising a bag content, the double-bag comprising an outer bag separated from an inner bag with the inner bag being arranged inside the outer bag, wherein a wall of the outer bag comprises a cellulose-based material and a wall of the inner bag comprises a plastic-based material enclosing an inner compartment (42) comprising a bag content (6), the opening system is configured for proving an opening operation wherein at least a first part of the outer bag is separated from a second part of the outer bag by a perforation such that the inner bag is exposed, the opening system comprises

• a laser arrangement comprising one or more laser units emitting laser light comprising having wavelengths in the range of 7-13 um,
• a displacement arrangement for displacing at least one of the one or more laser units and/or the double-bag to expose a wall area of the outer bag to the emitted laser light;
• and
• a control system adapted to received information of thickness of the wall of the outer bag wall and/or bag type to be processed and to control an emitted power from the laser arrangement to the wall area based on the received information of the thickness of the wall of the outer bag wall and/or a bag type to be processed, so as to at least provide a perforation of the outer bag in the said exposed wall area.