Packaging machine and method for producing sealed packages

A packaging machine for producing sealed packages of a pourable product from a web of packaging material;

• the packaging machine comprises:
• a conveying device for advancing the web of packaging material along a web advancement path at least to a tube forming station at which the web of packaging material is formed, in use, into a tube and for advancing the tube along a tube advancement path;
• a tube forming and sealing device configured to form the tube at the tube forming station and to longitudinally seal the tube;
• a tensioning device arranged upstream of the tube forming station along the web advancement path and configured to control at least the tension of the tube;
• and
• a control unit configured to control operation of the packaging machine;
• wherein the tensioning device comprises at least
• a main drive roller rotatable around a main rotation axis;
• a main drive motor configured to actuate rotation of the main drive roller around the main rotation axis;
• wherein the control unit is configured to control the main drive motor such that an angular speed and/or angular acceleration of the main drive roller is cyclically varied such to control the tension of the tube;
• wherein the control unit is configured to control the main drive motor such that the angular speed and/or the angular acceleration of the main drive roller is varied according to respectively a pre-defined and/or pre-determined speed profile and/or acceleration profile.