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 configured to control the tension of the web of packaging material and/or of the tube;
• and
• a control unit configured to control operation of packaging machine;
• wherein the tensioning device comprises at least one tensioning assembly arranged upstream of the tube forming station along the web advancement path and having at least:
• a first drive roller rotatable around a first rotation axis;
• a second drive roller rotatable around a second rotation axis;
• a first drive motor connected to the first drive roller and configured to actuate rotation of the first drive roller around the first rotation axis;
• and
• a second drive motor connected to the second drive roller and configured to actuate rotation of the second drive roller around the second rotation axis;
• wherein the control unit is configured to control the first drive motor and the second drive motor such that a free loop of the web of packaging material expands and/or advances, in use, between the first drive roller and the second drive roller;
• wherein the first drive roller is arranged upstream of the second drive roller along the web advancement path;
• wherein the control unit is configured to control the second drive motor such that an angular speed and/or an angular acceleration of the second drive roller is controlled and/or varied such to control the tension of the web of packaging material and/or of the tube;
• and
• wherein the control unit is configured to control the second drive motor such that the angular speed and/or the angular acceleration of the second drive roller is varied according to respectively a pre-defined and/or pre-determined speed profile and/or acceleration profile.