Method and device for producing a tubular wrapping

A folding method for forming a tubular wrapping about a substantially parallelepiped-shaped product, the method comprising the steps of:

• inserting the product (5), together with a sheet of wrapping material (4), inside a U-shaped pocket (16) having a longitudinal axis (17) and comprising a first and a second lateral wall (19, 18) parallel to said longitudinal axis (17), so as to fold said sheet of wrapping material (4) so that a first lateral portion (42) of the sheet of wrapping material is interposed between the product (5) and said first lateral wall (19), and a second lateral portion (47) of the sheet of wrapping material, opposite the first, is folded outside and beyond the pocket (16) and crosswise to the first lateral portion (42);
• moving said first lateral wall (19) from a closed position contacting the product (5), to an open position opening said pocket (16), while at the same time holding said first lateral portion (42) folded down on the product (5) by moving a contrast member (34) from a rest position outside said pocket (16), to a work position contacting the first lateral portion (42);
• subsequently folding said second lateral portion (47) onto the product (5), and so as to overlap the first lateral portion (42), by inserting an external folding member (40) into the pocket (16);
• returning said first lateral wall (19) to the closed position, and said contrast member (34) to said rest position;
• and
• withdrawing said external folding member (40) from the pocket (16).