The interfolding machine includes a first interfolding roller rotating around a first rotation axis and a second interfolding roller rotating around a second rotation axis parallel to the first rotation axis; wherein the first interfolding roller and the second interfolding roller form an interfolding nip therebetween. The interfolding machine further includes a first set of separation fingers associated with the first interfolding roller and arranged for reciprocatingly pivoting around a first pivoting axis parallel to the first rotation axis. The reciprocating pivoting movement of the first set of separation fingers is controlled by a first actuation mechanism including a first desmodromic cam. The interfolding machine also includes a second set of separation fingers associated with the second interfolding roller and arranged for reciprocatingly pivoting around a second pivoting axis parallel to the second rotation axis. The reciprocating pivoting movement of the second set of separation fingers is controlled by a second actuation mechanism including a second desmodromic.

A conveying unit includes a rotatable roller having a first through-hole between the inside and the outside of the roller. A cylindrical member inside the roller has an opening and defines an annular chamber between the member and the roller. An insert borne by the roller inserted in the first through-hole thereof and contacting an external surface of the cylindrical member has a second through-hole in communication with the outside of the roller and extending through the first through-hole and the annular chamber. The first through-hole of the opening is configured such that, when the roller rotates, the insert transits at the opening, temporarily placing the outside of the roller in fluid communication with the annular chamber via the second through-hole, so that a sheet outside the roller and at the first through-hole is pulled against the roller by aspirating means and is conveyed.

A conveying unit includes a rotatable roller having a first through-hole between the inside and the outside of the roller. A cylindrical member inside the roller has an opening and defines an annular chamber between the member and the roller. An insert borne by the roller inserted in the first through-hole thereof and contacting an external surface of the cylindrical member has a second through-hole in communication with the outside of the roller and extending through the first through-hole and the annular chamber. The first through-hole of the opening is configured such that, when the roller rotates, the insert transits at the opening, temporarily placing the outside of the roller in fluid communication with the annular chamber via the second through-hole, so that a sheet outside the roller and at the first through-hole is pulled against the roller by aspirating means and is conveyed.

Folding or interfolding unit of a web, or sheet, of paper, comprising a first and a second folding or interfolding roll, of a web, or sheet, of paper, configured to fold or interfold, the web or sheet of paper according to a predetermined folding or interfolding configuration, at a folding or interfolding zone arranged between the first and the second folding or interfolding roll. The folding or interfolding unit comprise, furthermore, a first and a second plurality of detaching fingers configured to cause the web or sheet of paper to be detached from the external surface of the respective folding or interfolding roll.

Folding or interfolding unit of a web, or sheet, of paper, comprising a first and a second folding or interfolding roll, of a web, or sheet, of paper, configured to fold or interfold, the web or sheet of paper according to a predetermined folding or interfolding configuration, at a folding or interfolding zone arranged between the first and the second folding or interfolding roll. The folding or interfolding unit comprise, furthermore, a first and a second plurality of detaching fingers configured to cause the web or sheet of paper to be detached from the external surface of the respective folding or interfolding roll.

A plurality of interleaved insulated foil sheets including a plurality of insulated foil sheets, each including a foil layer, an adhesive layer disposed on the foil layer, and a paper layer disposed on the foil layer; wherein a first insulated foil sheet is folded to create a first crease dividing the first insulated sheet into a first upper leaf and a first lower leaf and a second insulated foil sheet is folded to create a second crease dividing the second insulated sheet into a second upper leaf and a second lower leaf; and wherein the first upper leaf of the first insulated foil sheet is disposed between the second upper leaf and the second lower leaf of the second insulated sheet and the second lower leaf of the second insulated foil sheet is disposed between the first upper leaf and the first lower leaf of the first insulated sheet.

A conveying unit (100) of a web, or sheet, of paper, or similar products, arranged to transfer along a transfer direction the web, or sheet, of paper, having a support (41) having a lateral surface (42) provided with at least one peripheral suction groove (43). A suction belt (45) is arranged to move along a closed trajectory (46) comprising the suction portion (44). The suction belt (45) is configured to air-tightly engage the suction portion and provides at least one through hole (47) arranged to be positioned at a respective suction portion (43) in order to cause a suction effect on the web, or sheet, and to transfer it from a first point P1 to a second point P2 of a production line of paper products. It is, furthermore, provided a driving device (60) configured to move the suction belt (45) with respect to the support (41).

A conveying unit (100) of a web, or sheet, of paper, or similar products, arranged to transfer along a transfer direction the web, or sheet, of paper, having a support (41) having a lateral surface (42) provided with at least one peripheral suction groove (43). A suction belt (45) is arranged to move along a closed trajectory (46) comprising the suction portion (44). The suction belt (45) is configured to air-tightly engage the suction portion and provides at least one through hole (47) arranged to be positioned at a respective suction portion (43) in order to cause a suction effect on the web, or sheet, and to transfer it from a first point P1 to a second point P2 of a production line of paper products. It is, furthermore, provided a driving device (60) configured to move the suction belt (45) with respect to the support (41).

Suction roller structure for the pneumatic transport of sheets inside an interfolding unit, comprising a suction source, an external roller (3) rotating with respect to the cylinder (1) and provided with longitudinal rows of bores (4) angularly spaced and selectively communicating with said internal cavity (2) during the angular rotation of the roller (3), a distribution of pneumatic valves (5) that are normally closed, inserted between said internal cavity (2) and at least one bore (4), cam means (6) operatively associated with the rotation of the roller (3) and arranged to open one or more of said valves (5) at one or more angular positions taken by the roller (3).

Suction roller structure for the pneumatic transport of sheets inside an interfolding unit, comprising a suction source, an external roller (3) rotating with respect to the cylinder (1) and provided with longitudinal rows of bores (4) angularly spaced and selectively communicating with said internal cavity (2) during the angular rotation of the roller (3), a distribution of pneumatic valves (5) that are normally closed, inserted between said internal cavity (2) and at least one bore (4), cam means (6) operatively associated with the rotation of the roller (3) and arranged to open one or more of said valves (5) at one or more angular positions taken by the roller (3).