An interfolding machine (1) is described, including folding rollers (3). Such a roller has a cylindrical sleeve (3C) having a rotation axis (3A), an outer surface (3X) and an inner surface (3Y) defining an inner axial cavity (23) of the cylindrical sleeve (3C). The cylindrical sleeve includes, furthermore, a plurality of suction holes (41, 43) which extend from the outer surface (3X) to the inner surface (3Y) of the cylindrical sleeve (3C). The suction holes are arranged depending on longitudinal alignments (42, 44), parallel to the rotation axis (3A) of the cylindrical sleeve (3C) and angularly staggered in relation to one another. Inside a suction chamber (23A) in the cylindrical sleeve (3C), shutters are stationarily arranged having closing surfaces (37A) cooperating with the inner surface (3Y) of the cylindrical sleeve (3C) to selectively close the suction holes.

The invention provides a fiber product folding and stacking system comprising at least one folding wheel, a plurality of suction channels, a plurality of valves and a plurality of passages. The folding wheel includes a plurality of protruding wheels and a plurality of recessing wheels. The protruding wheels and the recessing wheels are adjacent to each other, and suction channels are arranged within the protruding wheels. The passages are disposed in the folding wheel and are fluidly connected to the suction channel. The valves are disposed within the recessing wheels of the folding wheel, and include a connecting opening, a valve channel and a valve opening. When the folding wheel rotates, portion of the suction channels will be fluidly connected to the valve channel through the passage and the valve opening to generate a negative pressure thereon for absorbing the fiber product.

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).

A machine for folding, cutting, and stacking napkins is provided. The machine has a feeding station, at least one pair of folding rollers pivoting about horizontal rotational axes, a blade, and a pair of spacers having fingers configured to support the napkins stably downstream of the blade, with respect to a horizontal plane perpendicular to a direction of travel, the folding rollers being provided with circumferential slots for inserting the spacers.

A machine for folding, cutting, and stacking napkins is provided. The machine has a feeding station, at least one pair of folding rollers pivoting about horizontal rotational axes, a blade, and a pair of spacers having fingers configured to support the napkins stably downstream of the blade, with respect to a horizontal plane perpendicular to a direction of travel, the folding rollers being provided with circumferential slots for inserting the spacers.

A suction roll of a web, or sheet, of paper, includes a tubular body that rotates about a longitudinal rotation axis. External and internal lateral surfaces of the suction roll pneumatically communicate with each other through suction holes. The roll includes a suction chamber pneumatically connected to a vacuum generation device for generating a predetermined vacuum degree. A vacuum distribution device selectively puts into pneumatic communication the suction chamber with at least one row of suction holes, at determined angular positions of the tubular body and causes the processed sheet or web of paper to be sucked, and to adhere at a corresponding portion of the external lateral surface arranged between a catching point and a releasing point having determined angular positions. A displacement device moves the vacuum distribution device to change the angular position of the catching or releasing point of the web or sheet of paper.

A dispenser and a stack combination. A dispenser that contains a stack of sheet products and which defines a dispensing path from a product reservoir containing and holding the stack to a dispensing opening through which the sheet products are dispensed. A stack of interfolded webs wherein the lines of weakness of one web are offset from the lines of weakness of another web in a longitudinal direction.

A dispenser and a stack combination. A dispenser that contains a stack of sheet products and which defines a dispensing path from a product reservoir containing and holding the stack to a dispensing opening through which the sheet products are dispensed. A stack of interfolded webs wherein the lines of weakness of one web are offset from the lines of weakness of another web in a longitudinal direction.

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.