System and method for forming and fanfolding a sheet material

A system (1) for forming and fanfolding a sheet material from a continuous web (M) of indefinite length having a bottom side (S1), a top side (S2) and longitudinal side edges (B), the system (1) comprising:

• a frame (3′, 3″) defining a vertical center plane (π);
• a feeding device having means for guiding the continuous web (M) in a longitudinal direction (L);
• a creasing device (2) located downstream of said feeding device to form transverse creases (C1, C2) on the continuous web (M) spaced apart at a constant longitudinal pitch (K) and defining adjacent partitions (P);
• a folding device (14) located downstream of said creasing device (2) for progressively and alternately fanfolding the adjacent partitions (P) along the creases (C1, C2);
• wherein said folding device (14) comprises at least one first group (15) of thrust tools (17) acting on the creases (C1) formed on the bottom side (S1) of the continuous web (M) and at least one second group (16) of thrust tools (18) acting on the creases (C2) formed on the top side (S2) of the continuous web (M), the thrust tools (17, 18) of each group (15, 16) being mechanically connected to and operably dependent on each other so that all the tools (17, 18) of the same group (15, 16) are forced to follow the same trajectory (T1, T2), the thrust tools (17, 18) of the same group (15, 16) being supported at the free ends of first series (27) and second series of articulated arms (28).