Fecha de publicación: -- Fuente: WIPO "tomato" A packaging machine for forming sealed packages comprises: a conveying device, configured to advance a packaging material web; an isolation chamber; a tube forming device configured to form a tube from the advancing packaging material web; a delimiting element arranged within the tube and designed to divide the tube in first and second spaces; a pressurizing device configured to direct a sterile gas flow into the second space for obtaining a second gas pressure within the second space; a sealing device; a filling device; a package forming unit configured to form and transversally seal the packages from the advancing tube; a tensioning device; a control unit configured to control the conveying device and/or the tensioning device and/or the package forming unit to vary an advancement speed of the tube and a release speed of the formed/sealed packages, and to control the pressurizing device to vary the second gas pressure.