Abstract: There is described a forming unti (1) for producing sealed packages (2) from a tube (3) of sheet packaging material fed along a feed path (A) and filled with a pourable food product. The unit (1) has jaw means (6, 6?) acting cyclically on the tube (3) to grip and seal it at equally spaced cross sections defining opposite sealing bands (15) of the packages (2); interacting means (23; 16) interacting with the tube (3) and fitted movably to the jaw means (6, 6?); and actuating means (27; 40) for operating the interacting means (23; 16) and mounted entirely on the jaw means (6, 6?).

Abstract: A decoration correction method for a form-and-seal unit (1) for producing sealed packages of a pourable food product from a tube (2) of packaging material fed along a feed path, and having two pairs of jaws (7) movable along the feed path and opened and closed so as to travel, cyclically and alternately with each other, along a form-and-seal portion along which the pairs of jaws (7) are closed and travel integrally with the tube, and along a repositioning portion along which the pairs of jaws open and move with respect to the tube (2). To make a decoration correction, a nominal trajectory (P) of the jaws (7) is modified along the repositioning portion on the basis of a position error of the tube (2) with respect to a nominal position. A first solution provides for correcting the travel of the jaws by selectively modifying the amplitude of the trajectory; and a second solution provides for correcting the phase of the jaw trajectory.