Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H45/00—Folding thin material
  • B65H45/12—Folding articles or webs with application of pressure to define or form crease lines
  • B65H45/16—Rotary folders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H45/00—Folding thin material
  • B65H45/12—Folding articles or webs with application of pressure to define or form crease lines
  • B65H45/28—Folding in combination with cutting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H45/00—Folding thin material
  • B65H45/12—Folding articles or webs with application of pressure to define or form crease lines
  • B65H45/16—Rotary folders
  • B65H45/162—Rotary folders with folding jaw cylinders
  • B65H45/165—Details of sheet gripping means therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2406/00—Means using fluid
  • B65H2406/30—Suction means
  • B65H2406/33—Rotary suction means, e.g. roller, cylinder or drum
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2406/00—Means using fluid
  • B65H2406/30—Suction means
  • B65H2406/36—Means for producing, distributing or controlling suction
  • B65H2406/361—Means for producing, distributing or controlling suction distributing vacuum from stationary element to movable element
  • B65H2406/3612—Means for producing, distributing or controlling suction distributing vacuum from stationary element to movable element involving a shoe in sliding contact with flanges of a rotating element
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2406/00—Means using fluid
  • B65H2406/30—Suction means
  • B65H2406/36—Means for producing, distributing or controlling suction
  • B65H2406/363—Means for producing, distributing or controlling suction adjusting or controlling distribution of vacuum for a plurality of suction means

Definitions

• the present invention concerns the field of apparatuses for the production of paper products such as tissue paper, napkins or other products in general with high speed folding machines operating with a vacuum system.
• Such machines normally comprise two or more mutually cooperating folding cylinders, according to the type of product to be made.
• Work speed, and consequently productivity limitations substantially depend upon the system for holding the material to be folded over the cylinders along the direction that is transverse with respect to the advancing direction.
• the most critical step is that in which the paper segments pass from a first cylinder, which normally provides also for a transversal cut of the paper, to a second cylinder so as to indeed execute the first transversal folding line. It is in this step that at the high speed at which such machines operate, there is the difficulty of ensuring a correct movement of the product from the condition in which it adheres to the first cylinder to that in which it adheres to the second cylinder. In order to minimise the risk of defects or malfunctioning it is necessary for the work speed to not exceed a set limit.
• the object of the present invention is to provide a system that solves such a problem, by providing a cross-wise folding unit for folding the product that makes it possible to increase production speed beyond the current production limits, obtaining at the same time a high quality product, i.e. without the defects caused today by the passage of the product through the folding cylinders.
• FIG. 1 is a schematic side view of a folding unit according to the invention, with parts that have been removed for the sake of clarity;
• FIG. 1 is a side view of a first folding cylinder
• - fig. 3 is a sectional view of the first cylinder according to the arrows III of figure 2;
• FIG. 4 and 5 are a side view and a sectional view according to the arrows V- V, respectively, of a first sequential valve, which is arranged on a first side (left side according to the view of figure 3) of the first folding cylinder;
• FIG. 6 and 7 are a side view and a sectional view according to the arrows VII-VII, respectively, of a second sequential valve that is arranged on a second side
• FIG. 8 and 9 are a side view and a sectional view according to the arrows IX- IX, respectively, of a single sequential valve that, according to an embodiment that is different from those of figures 4 to 7, is arranged on one side of the first folding cylinder.
• a folding unit according to the present invention can advantageously provide for one or more adjacent channels which operate in parallel and it is fed with continuous bands of paper 1 , having one or more layers (plies), with or without longitudinal folds with respect to the advancing direction.
• the unit according to the present invention comprises, as known, a cutting cylinder 2 which cooperates with a first folding cylinder 3 so as to provide for cutting the product into segments with two blades 16 that are diametrically opposite one another (on the cutting cylinder 2) and two corresponding anvil grooves or counter- blades 17 (on the first folding cylinder 3), starting from a single band of paper 1. Subsequently, the same first folding cylinder 3 and a second folding cylinder 4 that counter-rotates with respect to the first cooperate in a tangential manner, at a pinch point in which the material is held by the second cylinder, so as to provide for folding the paper S obtained from the band 1 by means of cutting.
• the first folding cylinder 3 comprises suction channels 5, 5' which extend axially near to the work surface 3a, for the passage of a vacuum that is suitable for keeping the band or segments of paper over such a surface.
• the channels 5, 5 ! continuously cover the entire circumferential development of the cylinder, opening up on the surface 3a through holes 6, 6'.
• the band of paper 1 is held in this way during cutting and thereafter the cut segment S is also held up to a release point from the first cylinder 3, with a vacuum of a sufficient strength, which is regulated through two sequential valves 7, 13 (not represented/visible in figure 1 but shown isolated in figures 4 to 7) that are alongside one another and in contact on respective axial ends (or sides) of the aforementioned first cylinder.
• Each valve is in practice a full fixed disc that blocks the ends of the channels 5 except for at suitably designated slots 9, 11 , 14, which will be described in greater detail hereafter, which over certain set arcs of rotation make it possible for the vacuum flow to pass, said flow being generated and supplied by vacuum-generating devices that are arranged outside and are not represented.
• slots 9, 11 , 14 which will be described in greater detail hereafter, which over certain set arcs of rotation make it possible for the vacuum flow to pass, said flow being generated and supplied by vacuum-generating devices that are arranged outside and are not represented.
• the suction channels extensively involve the work surface 3a, since they are spaced apart with a suitable density with respect to the evolution of the circumference.
• the majority of the channels, indicated with reference numeral 5, are open on the end side facing the first sequential valve 7 and are closed on the opposite side, so that the pneumatic circulation inside the aforementioned channels 5 is only determined by the first valve.
• Some channels, on the other hand, in particular two channels 5' that are diametrically opposite one another in an immediately adjacent position with respect to the counter-blades 17 (upstream considering the rotation direction of the first cylinder) are open on the end side facing the second sequential valve 13 and are closed on the side of the first valve, so that the pneumatic circulation inside the (two) channels 5' is determined only by the interference with the second valve 13.
• the tangential cooperation point between the first and the second folding cylinder is that in which the segment S of paper is released from the first cylinder 3, through gripping of the second cylinder 4 along a transversal intermediate line; consequently the paper becomes folded along such a line on the second cylinder 4.
• sets of axial channels 20 and holes 21 which open radially on the work surface 4a of the cylinder, which are capable of providing for gripping or pinching the sheet through suction.
• the first sequential valve 7 has two consecutive slots 9, 11 , which are separated by an interruption, i.e. by a solid separating wall 10, that overall extend for an arc of rotation of around 270°.
• a first slot 9 occupies around 180° of rotation and, in it, through the intake 8, a high vacuum is generated, which results through the channels 5 and the holes 6 in a suction by the work surface 3a on the paper S.
• slot 14 is provided, for the generation of high vacuum that is transmitted through the two channels 5' and relative holes 6'.
• This slot 14 extends by covering the same 180° of the first slot 9 of the first valve, and further on develops over a substantial part of the 90° of the second slot 11.
• the slot 14 ends with an advance of a certain angle (typically between 15° and 30°, thus corresponding to a rotation angle downstream of the release point comprised between 60° and 75°).
• the functions of the second sequential valve can be integrated on a single valve 107 thorough a double array of slots, which are radially offset to a greater or lesser extent.
• the slots 109 and 11 with the relative suction intakes, correspond to the previous slots 9 and 11 of the first embodiment, whereas a double slot 114a, 114b operationally corresponds to the slot 14 of the first example.
• Two consecutive and separated segments 114a, 114b are used in this case for a possible differentiation of suction (higher or lower vacuum) in two respective advancing steps upstream and downstream of the release/pinch point, respectively, also in connection with the hold at the front edge.
• Such a differentiation which can be useful according to the type of material being treated, can also be obtained in the first embodiment by separating the groove 4 into two distinct segments.
• the structure of the first folding cylinder (not shown) must be correspondingly adapted, since in this case the two channels corresponding to the channels 5' of the first embodiment, i.e. the channels that are suitable for holding the front edge of the segment and for communicating with the slots 114a, 114b, are made in a position that is radially more centred with respect to the other normal peripheral channels which correspond to the channels 5 of the first embodiment and in which there is the pneumatic opening/closing action of the slots 109 and 111.
• high vacuum in the present description, it is meant a high vacuum, ultra high vacuum or extremely high vacuum according to the definitions that are commonly and conventionally used in the field.

Landscapes

• Folding Of Thin Sheet-Like Materials, Special Discharging Devices, And Others (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49683846

Family Applications (1)

Country Status (7)

Citations (2)

Family Cites Families (10)

• 2013
  • 2013-10-10 IT IT000235A patent/ITFI20130235A1/it unknown
• 2014
  • 2014-10-01 CN CN201480056046.3A patent/CN105745169B/zh not_active Expired - Fee Related
  • 2014-10-01 US US15/027,764 patent/US20160251193A1/en not_active Abandoned
  • 2014-10-01 WO PCT/IB2014/064993 patent/WO2015052619A1/en active Application Filing
  • 2014-10-01 EP EP14796549.5A patent/EP3055241B1/en active Active
  • 2014-10-01 CA CA2924776A patent/CA2924776A1/en not_active Abandoned
  • 2014-10-01 RU RU2016117908A patent/RU2663975C2/ru not_active IP Right Cessation

Patent Citations (2)

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