A fluid ejection system comprising a cartridge, an ejector and, optionally, a fill station for filling the cartridge with a fluid, such as a vaccine. Adhesion between the bags and ultimate separation of the bags may be flexibly controlled with an interfolding of the bags and control of an orifice which applies drag to the bags and compression as they are removed. To counteract this change in metacentric height, the columns are so adapted that the moment of area inertia of the waterline area of the columns decreases on downward heave motion and increases on upward heave motion. The irradiation unit irradiates the light-curing material supplied into the slit area with laser light through the pressing mechanism and the film.