WO2025248403A2

WO2025248403A2 - Tissue paper converting line

Info

Publication number: WO2025248403A2
Application number: PCT/IB2025/055357
Authority: WO
Inventors: Fabrizio Lorenzi
Original assignee: Valmet Tissue Converting SpA
Current assignee: Valmet Tissue Converting SpA
Priority date: 2024-05-29
Filing date: 2025-05-23
Publication date: 2025-12-04
Anticipated expiration: 2026-11-29
Also published as: WO2025248403A3

Abstract

A tissue paper converting line is disclosed, comprising a plurality of sequentially arranged operating units. A conveyor is provided between an upstream operating unit and a downstream operating, the conveyor comprising at least one endless belt configured to transfer a ply of tissue paper from the upstream operating unit to the downstream operating unit.

Description

TISSUE PAPER CONVERTING LINE

DESCRIPTION

TECHNICAL FIELD

[0001] The invention relates to the field of tissue paper. More specifically, the invention concerns tissue paper converting lines, for example for producing tissue paper rolls or packs of folded and/or interfolded tissue paper sheets.

BACKGROUND ART

[0002] Tissue paper is used for the production of a variety of sanitary and hygiene articles. In particular, tissue paper is for example used to produce rolls or stacks of sheets, folded and optionally interfolded.

[0003] Tissue paper is typically produced through wet methods. The production starts from the preparation of an aqueous suspension of cellulose fibers, containing other chemical or physical components to impart the desired characteristics to the final product. For example, the suspension may contain wet-strength resins, which provide the final product with greater mechanical resistance to humidity. The aqueous suspension contains a very low dry content (i.e., cellulose fibers), typically around 2- 5% by weight. A layer of aqueous suspension of cellulose fibers, or pulp, is laid on a forming fabric through headboxes. The forming fabric transfers the layer along a path where other endless members may be present, such as felts or fabrics, and along which means for the gradual removal of water from the aqueous suspension layer are arranged in order to increase the dry content. The water removal systems may comprise suction systems, pressure systems, thermal systems, etc.

[0004] Once the pulp layer has a sufficiently high solid content to ensure adequate mechanical strength, the layer is transferred to drying systems, for example comprising a Yankee cylinder, internally heated and surrounded by suction hoods. The heat provided by the Yankee cylinder to the pulp layer removes moisture down to a value (typically around 1-2% by weight of water), after which the pulp layer is wound into reels. The reels are then transferred to a converting line where the pulp layer, consisting of tissue paper, is converted into a finished product through a plurality of mechanical operations, which may vary depending on the desired end product. [0005] An important aspect in tissue paper production concerns the softness and thickness of the paper. Many techniques are used in the production process with the aim of obtaining a high thickness and high softness. In particular, in order to obtain a tissue paper ply of high bulk (high thickness), a technology has been developed for removing water from the pulp layer formed on the forming fabric, which avoids the use of pressure systems to squeeze water from the pulp layer. Indeed, pressure systems cause a reduction in thickness, and therefore in volume, of the final cellulose ply. This technology is known as TAD (Through Air Drying) and is based on the idea of removing water from the pulp layer by passing the layer around a porous cylinder (TAD cylinder), through which hot, dry air is forced to pass, coming from hoods surrounding the TAD cylinder, from the outside toward the inside. The hot air passes through the pulp layer driven around the TAD cylinder. The layer from which a large amount of water has been removed by the air flow is then transferred to the Yankee cylinder for final drying.

[0006] A creping blade detaches the layer from the cylindrical surface of the Yankee cylinder, imparting to the layer the typical creping of tissue paper.

[0007] While tissue paper produced with TAD technology offers high quality in terms of softness and strength, it involves high energy consumption, due to the need to heat large quantities of air.

[0008] The subsequent operations for converting the cellulose ply into finished product require mechanical handling of the cellulose ply, or of multiple cellulose plies in parallel, through a plurality of stations or operating units arranged sequentially along the converting line, until the finished and packaged product is obtained. In particular, the converting line comprises an initial portion where tissue paper reels are unwound by one or more unwinders. The ply or plies of tissue paper unwound from the reels are fed to a series of operating units, in which the first operating units convert the continuous plies, for example by calendering, embossing, bonding multiple plies. After an initial processing of the tissue paper plies in continuous form, the plies are converted into semi-finished final products, such as rolls or logs, or into folded and optionally interfolded sheets.

[0009] In the first portion of the converting line, where the cellulosic material is fed in the form of a continuous tissue paper ply, the ply itself must be guided around guide rollers toward and through the operating units, starting from the unwinder. This requires that the tissue paper ply be kept under a certain tension, otherwise it is not possible to guide it at the production speed of the converting lines, which may be several hundred meters per second, for example up to 1000 m/s.

[0010] The tensioning of the plies and their guidance around guide rollers causes degradation of the mechanical and physical properties of the tissue paper. In particular, a significant reduction in the thickness of the tissue paper ply can occur, as well as fiber loss from the plies with resulting dust formation that accumulates significantly in the converting line, with consequent loss of the advantages obtained during the production of the ply using costly and energy-intensive techniques such as TAD drying.

[0011] It would therefore be desirable to provide improvements in tissue paper converting lines that reduce these drawbacks, and in particular allow the reduction of the negative effects of mechanical stresses, particularly tension, to which the tissue paper plies are subjected in prior art converting lines.

SUMMARY OF THE INVENTION

[0012] To solve or to mitigate the problems of the prior art converting lines, various versions of a tissue paper converting line are described herein, which comprise a plurality of operating units arranged in sequence, wherein a first conveyor is arranged between an upstream operating unit and a downstream operating unit, the first conveyor comprising at least one endless belt configured to transfer a tissue paper ply from the upstream operating unit to the downstream operating unit.

[0013] Various embodiments and features of possible converting lines are described below and defined in the appended claims.

[0014] In practice, the use of endless belts for feeding the tissue paper plies makes it possible to reduce or to eliminate the tension to which the plies are subjected when moving forward along the line. In this way, the drawbacks of the prior art lines are avoided or reduced.

[0015] The configurations described herein are particularly useful and advantageous in converting lines in which TAD paper is fed and processed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention will be better understood from the following description and the attached drawings, which illustrate an exemplary and non-limiting embodiment of the invention. More particularly, in the drawings:

Fig. 1 shows a side view of a portion of a tissue paper converting line in one embodiment;

Figs. 2A, 2B, 2C: show enlarged views of three consecutive portions A, B, and C of the converting line in Fig. 1;

Fig. 2D shows an enlarged view of a detail of the line in Figs. 1, 2A, 2B, 2C in a modified embodiment;

Fig. 2E shows an enlarged view of a further detail of the line in Figs. 1, 2A, 2B, 2C in a modified embodiment;

Fig. 3 shows an enlarged view of a ply splicing unit of the line in Figs. 1, 2A, 2B, 2C;

Fig. 3D shows an enlarged view of a detail of the line in Figs. 3 A, 3B, 3C in a modified embodiment;

Figs. 4A, 4B, 4C show three consecutive portions, similar to those shown in Figs. 2A, 2B, 2C, in a further embodiment;

Fig. 4D shows an enlarged view of a detail of the line in Figs. 4A, 4B, 4C in a modified embodiment;

Figs. 5A, 5B, 5C show three consecutive portions, similar to those shown in Figs. 2A, 2B, 2C, in a further embodiment;

Fig. 5D shows an enlarged view of a detail of the line in Figs. 5A, 5B, 5C in a modified embodiment;

Figs. 6A, 6B, 6C show three consecutive portions, similar to those shown in Figs. 2A, 2B, 2C, in a further embodiment;

Fig. 6D shows an enlarged view of a detail of the line in Figs. 6A, 6B, 6C in a modified embodiment;

Fig. 7 is a side view of an unwinder in a further embodiment;

Fig. 8 is a side view of an unwinder in a further embodiment;

Fig. 9 is a side view of an unwinder in a further embodiment; Fig. 10 is a side view of an unwinder in a further embodiment;

Fig. 11 is a side view of a pair of unwinders in a further embodiment;

Figs. 12, 13, 14, 15, and 16 show a sequence of operating steps of a double station unwinder usable in a line according to the present description;

Figs. 17, 18, 19, 20, and 21 show a sequence of operating steps of a double station unwinder similar to the unwinder of Figs. 12 to 16;

Figs. 22, 23, and 24 show three variants of embodiments of a further double station unwinder usable in a line according to the present description;

Figs. 25, 26, and 27 show three variants of a further embodiment of a double station unwinder usable in a line according to the present description.

DETAILED DESCRIPTION

[0017] A first embodiment of a converting line is illustrated in Figs. 1 to 3. Fig. 1 shows the overall converting line 1, while Figs. 2A, 2B, 2C show in greater detail and enlarged the portions of the converting line 1 marked A, B, and C in Fig. 1.

[0018] It should be understood that the converting line 1 may actually comprise further units, stations, machinery, and processing paths downstream of what is illustrated in the attached drawings. For example, the converting line may include various roll sealing, roll storage or accumulation, roll cutting, and packaging stations. This further downstream portion of the converting line 1 is not relevant for the purposes of the present description and is therefore neither illustrated nor described.

[0019] In the embodiment of Figs. 1 to 4, the converting line 1 comprises a series of operating units arranged in sequence, through which two tissue paper plies VI and V2, coming from two reels, are fed and transformed into rolls or logs in the converting line 1. These are subsequently cut into smaller axial rolls for sale, for example toilet paper rolls, paper towel rolls, and the like. In lower-cost converting lines, it is possible to have only one tissue paper ply VI, unwound by a single unwinder as will be described below.

[0020] More specifically, the converting line 1 comprises a first operating unit consisting of a first unwinder 3 and, downstream thereof, a second operating unit consisting of a second unwinder 5. Downstream of the second unwinder 5, a ply bonding unit, designated 7, is provided. Downstream of the operating unit 7, a further operating unit 9 is provided, which in this embodiment comprises a rewinder.

[0021] The various operating units 3, 5, 7, and 9 are arranged in series, that is, sequentially, in the feed direction F of the cellulose material (tissue paper plies VI, V2) to be converted and, more specifically, along the path of each tissue paper ply VI, V2. Each pair of consecutive operating units thus generally consists of an upstream operating unit and a downstream operating unit.

[0022] In particular, the operating unit 7 constitutes the downstream operating unit of the (upstream) operating unit 5 and the upstream operating unit 3. At the same time, the operating unit 7 represents the upstream operating unit of the pair of consecutive operating units 7 and 9, of which the operating unit 9 is the downstream operating unit.

[0023] Characteristically, between an upstream operating unit and a downstream operating unit along a given path of the tissue paper ply V 1 and/or tissue paper ply V2, a conveyor is arranged comprising at least one endless belt configured to transfer one or more tissue paper plies from the upstream operating unit to the downstream operating unit. This general concept can be applied to any pair of operating units that are upstream and downstream with respect to each other and to each path of one or more tissue paper plies.

[0024] For example, and in particular, the first unwinder 3 and the bonding unit 7 form an upstream operating unit and a downstream operating unit, respectively, between which a conveyor is arranged comprising (at least) an endless belt which, as described in greater detail below, transfers the tissue paper ply VI from the unwinder 3 to the bonding unit 7.

[0025] Similarly, the second unwinder 5 and the bonding unit 7 form an upstream operating unit and a downstream operating unit, respectively, between which a conveyor is arranged comprising (at least) an endless belt which, as described in greater detail below, transfers the tissue paper ply V2 from the unwinder 5 to the bonding unit 7.

[0026] Similarly, the bonding unit 7 and the rewinder 9 form an upstream operating unit and a downstream operating unit, respectively, between which a conveyor is arranged comprising (in this embodiment) two endless belts in series, which convey a tissue paper ply formed by the coupled plies VI and V2.

[0027] In greater detail, by way of example in the embodiment of Figs. 1, 2A, 2B, 2C, and 3, the first unwinder 3 is an automatic unwinder having two unwinding stations 3 A, 3B for two reels Bl and B2, see in particular Fig. 2A.

[0028] In the automatic unwinder 3, one reel (for example the reel B2) is in standby, while the other (for example the reel Bl) is in operation, rotating and feeding the ply VI to the converting line. The numeral 11 generically indicates an automatic splicing device, which enables the tail edge of ply VI from the reel Bl to be joined to the leading edge of the ply VI from the standby reel B2, or vice versa, when the operating reel runs out.

[0029] The automatic splicing device is not shown and can be implemented in any suitable and known way, for example as described in EP 1601601, EP 1742860, EP3628615.

[0030] The automatic splicing can take place on-the-fly, i.e., without stopping feeding the ply VI coming from the operating reel, by accelerating the standby reel in rotation before performing the splicing. The splicing can be performed when the feed speed of the ply VI from the standby new reel B2 is approximately equal to the feed speed of the ply V 1 from the nearly empty reel B 1.

[0031] The first unwinder 3, which represents the upstream operating unit relative to the bonding unit 7 along the path of the first tissue paper ply VI, is associated with a first conveyor 13. In the illustrated example, the first conveyor 13 comprises a single endless belt 15, which extends from the unwinder 3 to the bonding unit 7. Between the splicing device 11 and the conveyor 13, a take-up roller 17 may be arranged, which controls and stabilizes the tension of the tissue paper ply VI. The take-up roller 17 may be configured and operate as described in EP1507726B1. Although not strictly necessary, the use of the take-up roller 17 is advantageous because the feed of the plies from the reels is often not at constant tension, due to the eccentricity of the reels.

[0032] By way of example in the embodiment of Figs. 1, 2A, 2B, 2C, and 3, the second unwinder 5 is also an automatic unwinder, having two unwinding stations 5A, 5B for two reels B3 and B4, see in particular Fig. 2B. [0033] In the automatic unwinder 5, one reel (for example the reel B4) is in standby, while the other (for example the reel B3) is in operation, rotating and feeding the ply V2 to the converting line. The numeral 18 generically indicates an automatic splicing device, which enables the tail edge of the ply V2 from the reel B3 to be coupled to the leading edge of the ply V2 from the standby reel B4, or vice versa, when the operating reel runs out.

[0034] The second unwinder 5, which represents the upstream operating unit relative to the bonding unit 7 along the path of the second tissue paper ply V2, is associated with a second conveyor 19. In the illustrated example, the second conveyor 19 comprises a single endless belt 21, which extends from the second unwinder 5 to the bonding unit 7 along the path of the tissue paper ply V2. Between the splicing device 18 and the conveyor 19, a take-up roller 23 may be arranged, which controls and stabilizes the tension of the tissue paper ply V2. Fig. 2B also shows an alternative path for the ply V2 from the reel B3, along which an additional take-up roller 24 is provided.

[0035] The second conveyor 19 is arranged above the first conveyor 13 for at least part of the path between the second unwinder 5 and the bonding unit 7.

[0036] In Figs. 1 and 2A, 2B, the ply VI rests on the upper branch of the endless belt 15, while the ply V2 adheres to the lower branch of the endless belt 21. For this purpose, as schematically indicated by the arrows shown in Figs. 2A and 2B, the endless belt 21 may be suction-type. It is also possible that also the endless belt 15 is suction-type, for better guidance and better control of the tissue paper ply VI.

[0037] Fig. 2D shows the detail D from Fig. 2B in a variant embodiment, in which the ply V2 rests on the upper branch of the conveyor belt 21. Both the embodiments are possible. In the embodiment of Fig. 2D, the conveyor belt 21 may also be a suction belt, to provide better control of the ply V2.

[0038] Fig. 2C shows, in greater detail and enlarged, the portion C of the converting line 1 from Fig. 1. In Fig. 2C, the bonding unit 7 and the rewinder 9 are particularly visible. In the embodiment shown in Fig. 2C, the bonding unit 7 comprises a first continuous bonding belt 25, which forms part of the first conveyor 13. The first continuous bonding belt 25 cooperates with a second continuous bonding belt 27, which forms part of the second conveyor 19. The first and second continuous bonding belts 25, 27 have respective active branches pressed against one another along a common path where the tissue paper ply VI and the tissue paper ply V2 advance. The numeral 29 indicates a pressing member, for example a pressing plate. The bonding unit 7 further comprises a dispenser for a functional fluid, for instance a glue. The dispenser is designated by 31 and is located upstream of the common path defined between the first and the second continuous bonding belts 25, 27. The fluid dispenser 31 is adapted to dispense the functional fluid onto at least one of the tissue paper plies VI and V2. In the illustrated example, the functional fluid is applied to the upper face of the ply VI, which faces the ply V2.

[0039] Fig. 2C shows how the ply V2 is transferred from the lower branch of the continuous conveyor belt 21 to the underside of the continuous bonding belt 27, which is a suction belt for holding and advancing the tissue paper ply V2. Fig. 2E shows the detail E of Fig. 2C, in a variant where the tissue paper ply V2 is in contact with the upper branch of the continuous conveyor belt 21.

[0040] In some embodiments, the continuous bonding belt 25 is suction-type for at least part of its length, and in particular along the zone where the functional fluid is applied, to provide better control of the tissue paper ply VI.

[0041] Fig. 3 shows an enlarged view of the bonding unit 7 in a variant embodiment, where the path of the tissue paper ply V2 is positioned at a higher level compared to what is shown in Fig. 2C.

[0042] Downstream of the bonding unit 7, between this unit and the rewinder 9, there is an additional conveyor 35, comprising a continuous conveyor belt 37, which extends to the inlet area of the rewinder 9. In the illustrated embodiment, the continuous conveyor belt 35 is a suction belt and has an ascending section and a horizontal section.

[0043] Figs. 4A, 4B, and 4C show three sequential portions of a converting line in a further embodiment. Identical numbers to those used in Figs. 1 to 2C indicate identical or equivalent parts, which will not be described again.

[0044] In this embodiment, the bonding unit 7 is replaced by an embossing unit 41, which is connected to the first unwinder 3 via the conveyor 13 transporting the tissue paper ply VI, and to the second unwinder 5 via the conveyor 19 transporting the tissue paper ply V2. As shown in Figs. 4B and 4C, the endless conveyor belt 15 of the conveyor 13 extends to the inlet of the embossing unit 41, while the ply V2 is brought to the inlet of the embossing unit 41 via an endless conveyor belt 43, which forms part of the conveyor 19 and is positioned in sequence with the conveyor belt 21.

[0045] In the illustrated embodiment, the endless conveyor belt 43 is a suction belt, for better control of the tissue paper ply V2.

[0046] As illustrated, the endless conveyor belt 43 has an inlet at a lower level and an outlet at a second, higher level. In practice, the endless conveyor belt thus lifts the tissue paper ply. This feature is also present in other embodiments described herein for one or more conveyors.

[0047] Lifting the tissue paper ply by means of the conveyor, that is, using one or more endless belts constituting, or forming part of, the conveyor, is particularly advantageous. Indeed, tissue paper converting lines typically have operating units at different levels, and the tissue paper ply is transferred across free spans to a high level. This can result in undesired displacement of the ply, for example due to air drafts, and even in ply breakage. To avoid or reduce undesired flapping of the ply, it is often necessary to apply a certain degree of tension, which increases the risk of tearing. By means of a continuous conveyor belt that supports the ply during the change in level, i.e., along a trajectory with an inlet and an outlet at different levels, typically an inlet at a lower level and an outlet at a higher level, these drawbacks are reduced.

[0048] In Figs. 4B and 4C, the tissue paper ply V2 is transported from the lower branch of the conveyor belt 21 to the conveyor belt 43. Fig. 4D shows the detail D of Fig. 4B in a modified embodiment, where the tissue paper ply V2 is transported on the upper branch of the conveyor belt 21.

[0049] The embossing unit 41 may have any structure suitable for embossing at least one of the two tissue paper plies VI, V2 and joining them by lamination, in a tip-to- tip, nested, DERL (Double Embossing Random Lamination), DESL (Double Embossing Synchronized Lamination), glue-embossing or other configuration. In the illustrated embodiment, by way of example, the embossing unit 41 comprises two embossing rollers 45, 47, co-acting with two pressure rollers 49, 51, and a laminating roller 53. The numeral 55 designates a dispenser for the glue or other functional fluid. [0050] From the embossing unit 41, the two tissue paper plies VI and V2, joined to form a double ply V1+V2, move toward the downstream operating unit, in this case consisting of a rewinder 9, via a conveyor 59 comprising an endless conveyor belt 61, preferably a suction belt.

[0051] Figs. 5A, 5B, and 5C show three sequential portions of a converting line in a further embodiment. Identical numbers to those used in Figs. 1 to 4C indicate identical or equivalent parts, which will not be described again.

[0052] In this embodiment, the bonding unit 7 using a functional fluid is replaced by a bonding unit that comprises a mechanical ply-bonding unit 63. From the mechanical ply -bonding unit 63, the composite tissue ply, formed by the plies VI and V2 bonded together, is transferred by a conveyor.

[0053] Fig. 5D shows an enlargement of the detail D from Fig. 5C, where the path of the tissue paper ply V2 is modified and travels along the upper branch instead of the lower branch of the conveyor belt 21.

[0054] Figs. 6A, 6B, and 6C show three sequential portions of a converting line in a further embodiment. Identical numbers to those used in Figs. 1 to 5C indicate identical or equivalent parts, which will not be described again.

[0055] In this embodiment, the bonding unit comprises a mechanical ply-bonding unit 63, as in Figs. 5A-5C. However, the mechanical ply-bonding unit 63 is located in a different position.

[0056] In fact, the plies VI and V2 advance from the first unwinder 3 and the second unwinder 5 via the respective conveyors 13 and 19 to an endless conveyor belt 69, which transports the two tissue paper plies VI and V2, superimposed but not bonded, to the mechanical ply-bonding unit 63, which is located near the inlet of the rewinder 9. The endless conveyor belt 69, which is a continuation of both conveyors 13 and 19, is a suction belt to ensure better control of the two plies VI and V2 during the upward movement toward the bonding unit 63.

[0057] Fig. 6D shows an enlargement of the detail D from Fig. 6C, where the path of the tissue paper ply V2 is modified and travels along the upper branch instead of the lower branch of conveyor belt 21. [0058] Fig. 7 shows a further embodiment of the unwinder 3. Equal numerals indicate equal or equivalent parts to those illustrated in the previous figures, which will not be described again. In Fig. 7, each unwinding station 3A, 3B comprises a peripheral unwinding member, indicated with 71A for the unwinding station 3A and with 71B for the unwinding station 3B. A similar configuration of the peripheral unwinding members may be provided for the unwinder 5. Each peripheral unwinding member may comprise a respective continuous flexible member, indicated with 73A, 73B, which is driven around a plurality of guide rollers, at least one of which is motorized. The torque required to keep the reels Bl, B2 in rotation is transmitted, in this case, by the peripheral unwinding members 71 A, 71B through friction between the continuous flexible members 73 A, 73B and the substantially cylindrical lateral surface of the reels B1, B2.

[0059] Each unwinder may comprise, in addition to the peripheral unwinding members, also central unwinding members (not shown) which transmit torque directly to the central core or shaft on which the reels Bl, B2 are wound. The peripheral and central unwinding members may operate in combination or alternatively.

[0060] Fig. 7 also shows a modified embodiment of the automatic splicing device. In this case, it comprises a dispenser for a functional fluid, for example a glue, indicated with 11 A, positioned upstream of a splicing area of the plies coming from the two reels during the transition phase from the unwinding of the reel B 1 to the unwinding of the reel B2, or vice versa. The device 11A may be replaced by a device 11 of the type described with reference to Fig. 2A.

[0061] A further embodiment of the unwinder 3 is shown in Fig. 8. The same configuration may be used for the unwinder 5. Equal numerals indicate equal or equivalent parts to those of Figs. 2A and 7, which will not be described again. The unwinder 3 of Fig. 8 differs from that of Fig. 7 by the presence of central unwinding members, which operate in combination and in sequence with the peripheral unwinding members. The central unwinding members are indicated with 75A, 75B for the two unwinding stations 3 A, 3B, respectively. They comprise motorized tailstocks which engage the ends of the winding rod of the reels B 1, B2 and, by rotating, transmit the unwinding torque directly to the reel rod. [0062] In the embodiment of Fig. 8, each of the central unwinding members 75A, 75B is carried by a respective pair of arms 77A, 77B (one arm for each of the two tailstocks of the central unwinding members). The arms rotate around axes 79A, 79B to alternately take: a lower position for loading the reel, and an upper unwinding position. In Fig. 8 both positions are shown for each of the two central unwinding members. It is to be understood that the arms 77A will alternately be in one or the other of the two angular positions shown in Fig. 8. The same applies to the arms 77B.

[0063] In practice, the unwinder 3 of Fig. 8 operates as follows. The reel in the unwinding phase is initially in position Bl or B2 shown in Fig. 8. When the reel is nearly empty or its diameter has decreased (e.g., by 50% or more) from its original diameter, it is engaged by the two motorized tailstocks carried by the arms 77A or 77B and transferred, by translation around the axis 79A or 79B, to the position indicated with BIX or B2X. In this position, the reel finishes dispensing the tissue paper ply wound on it, while a new reel may be introduced into the now free lower position.

[0064] An unwinder of this type is disclosed, for example, in US 11254534.

[0065] When the unwinder 3 and/or the unwinder 5 comprises peripheral unwinding members comprising respective continuous flexible members, the latter may form an integral part of the respective conveyor which transfers the respective tissue paper ply VI or V2 to the downstream operating unit, for example a bonding unit and/or an embosser. One embodiment of this type is illustrated in Fig. 9. In this embodiment, two unwinders with dual unwinding stations are not provided, but rather a configuration with two unwinders combined into a single machine. In practice, in the configuration of Fig. 9, the first unwinder 3 and the second unwinder 5 are placed close to each other and each has a single unwinding station, where there are respectively a reel Bl, dispensing the tissue paper ply VI, and a reel B2, dispensing the tissue paper ply V2. The replacement of an empty reel with a new one is performed by stopping the converting line.

[0066] The unwinder 3 comprises a peripheral unwinding member 81 which in turn comprises a continuous flexible member. In this embodiment, the continuous flexible member of the peripheral unwinding member 81 is constituted by the continuous conveyor belt 15 of the conveyor 13. [0067] Similarly, the unwinder 5 comprises a peripheral unwinding member 83 which in turn comprises a continuous flexible member. In this embodiment, the continuous flexible member of the peripheral unwinding member 83 is constituted by the continuous conveyor belt 21 of the conveyor 19.

[0068] In practice, the peripheral unwinding members of the two unwinders 3, 5 in this case extend up to the downstream operating unit, for example a bonding unit or an embosser.

[0069] Each unwinder 3, 5 of Fig. 9 may have a take-up roller, indicated with 85 for the unwinder 3 and with 87 for the unwinder 5.

[0070] In the embodiment of Fig. 9, each unwinder 3, 5 comprises only peripheral unwinding members, but this is not binding. For example, Fig. 10 shows an embodiment similar to that of Fig. 9, in which, however, each unwinder 3, 5 comprises not only peripheral unwinding members, but also central unwinding members, similar to the embodiment of Fig. 8.

[0071] In Fig. 10, equal numerals indicate parts identical to those illustrated in Fig. 9 and previously described, and which will not be described again. Differently from Fig. 9, each of the unwinders 3 and 5 of Fig. 10 also comprises central unwinding members, constituted, for example, by motorized tailstocks carried by swinging arms similar to those described with reference to Fig. 8. In Fig. 10, the motorized tailstocks of the unwinder 3 are indicated with 91 and are carried by arms 92 rotating around an axis 96 to alternately assume a lower position for engaging a partially empty reel and an upper unwinding position. In Fig. 10 both positions are shown. The motorized tailstocks of the unwinder 5 are indicated with 93 and are carried by arms 94 rotating around an axis 98 to alternately assume a lower position for engaging the partially empty reel, and an upper unwinding position. In Fig. 10 both positions are shown.

[0072] The reference numbers 85 and 87 indicate take-up rollers for the tissue paper plies VI and V2.

[0073] In this embodiment, when the reel being unwound is supported and rotated by the motorized tailstocks rather than by the peripheral unwinding members, the latter still remain in motion, as they are required to transfer the tissue paper plies VI and V2 to the downstream operating unit. However, this condition is not mandatory, and it is possible to implement unwinders in which, when the reel is engaged by the tailstocks, the peripheral unwinding members may be stopped.

[0074] One embodiment of this type is illustrated in Fig. 11. In this embodiment, two unwinders 3 and 5 are shown, each housing a reel Bl and B4, respectively, for dispensing tissue paper plies VI and V2. The unwinder 3 has a peripheral unwinding member 101 comprising a continuous flexible member 103 extending up to the continuous conveyor belt 15 forming part of the conveyor 13. Similarly, the unwinder 5 has a peripheral unwinding member 105 comprising a continuous flexible member 107 extending up to the continuous conveyor belt 21 forming part of the conveyor 19.

[0075] Within the path of the continuous flexible member 103 a suction box 109 may be provided, to which the portion of the continuous flexible member 103 extending towards the conveyor belt 15 adheres. Similarly, within the path of the continuous flexible member 107, a suction box 111 may be provided, to which the portion of the continuous flexible member 107 extending towards the conveyor belt 21 adheres.

[0076] In practice, in the embodiment of Fig. 11, the conveyor 13 transferring the tissue paper ply VI to the downstream operating unit comprises the conveyor belt constituted by the continuous flexible member 103 and the conveyor belt 15. The conveyor 19 transferring the tissue paper ply V2 to the downstream operating unit comprises the conveyor belt constituted by the continuous flexible member 107 and the conveyor belt 21.

[0077] Downstream of each of the unwinders illustrated in Figs. 7 to 11, operating units, illustrated in any of Figs. 1 to 6C, may be provided.

[0078] In all embodiments, beneath the converting line 1 a collecting tank may extend for cellulose residues that may fall from the converting line 1. The tank is designated with 110 and may contain water which can be kept in motion by a flow, for example in the direction FA (Fig.l). The water may be conveyed to a treatment station, not shown, or, if present in the production plant, to a liquid treatment station of a continuous machine.

[0079] In one or more of the above-described embodiments, the converting line may comprise, in one or more points, a measuring device associated with at least one of the continuous conveyor belts. The measuring device is adapted to detect an accumulation of the respective tissue paper ply on the conveyor belt or upstream thereof. Preferably, the measuring device is a contactless measuring device, so as not to interfere with the tissue paper ply. In some embodiments, the measuring device comprises a laser sensor member, or a capacitive sensor or other proximity sensor. It is also possible to use a video camera as the sensing member, which captures an image of the tissue paper ply and, through an appropriate image processing software, is capable of detecting the formation of an accumulation.

[0080] By way of example only, a measuring device of the type mentioned above is schematically represented by 112 in Figs. 2C, 4C, 5C, and 6C. In these figures, the measuring device is shown in the ply bonding area, but it should be understood that one or more measuring devices can be positioned in other areas of the converting line, and more precisely in any position where tissue paper accumulations may occur, caused by a too low speed of the downstream members or, conversely, tensioning of the tissue paper ply caused by a too high speed of the members downstream of the measuring point.

[0081] Advantageously, the measuring device, or each measuring device, can be functionally connected to an alarm system, which can signal an abnormal operating condition to an operator supervising the line.

[0082] In other embodiments, the measuring device, or each measuring device, can be connected to a control unit schematically indicated with 114, which can be configured to adjust a feed speed of at least one of the conveyor belts to eliminate a tissue paper accumulation and to avoid excessive tension in the transported paper ply or plies. This function is schematically represented with a functional connection to a motor 116 associated with one of the continuous conveyor belts. It should be understood that this measuring concept can be used at multiple points of the line and can be implemented by acting on one or more motors or actuators of the conveyors transporting the tissue paper plies VI, V2.

[0083] For example, the measuring device can detect the distance from the paper ply. If the distance increases, it means that more paper is being fed to the downstream operating units or conveyor than is being supplied from upstream, which causes tensioning of the tissue paper ply. Conversely, if the distance decreases, it means that the paper fed by one conveyor is greater than the amount taken by the downstream operating unit or conveyor, creating loops or accumulations. In this way, it is possible to convey the paper plies in a controlled manner with very low or even zero tension.

[0084] In the described embodiments, it is possible to provide systems for stabilizing the tension of the continuous belts forming part of the conveyors. For example, the continuous conveyor belts may be driven around guide rollers, of which at least one is motorized, see for example the motor 116. At least one of the guide rollers of one or more continuous conveyor belts can be movable so as to lengthen or to shorten the path of the conveyor belt and maintain constant tension in the conveyor belt itself. A roller configuration of this type is indicated with 20 in Fig. 2C.

[0085] Moreover, in the described embodiments, systems can be used to facilitate the passage of the paper ply between two consecutive continuous conveyor belts. For example, in the configurations equivalent to those shown in Fig. 4D, air systems such as air-foils can be used to connect one continuous conveyor belt with the next one. These devices facilitate the passage of the paper plies in the areas, albeit very short and limited, where the ply cannot be directly supported by a continuous conveyor belt. For example, the systems for facilitating the passage of the paper ply may comprise a sliding surface, or a sliding surface and an air nozzle, preferably a Coanda-effect nozzle, in order to create a laminar airflow directed in the feed direction of the paper ply, on which the ply can slide. This system is particularly advantageous when the downstream conveyor belt is a suction conveyor belt. This is because the laminar airflow supporting the paper ply is drawn by the suction of the downstream conveyor belt, creating continuity between: upstream continuous conveyor belt, system for facilitating the passage of the paper ply, and downstream conveyor belt.

[0086] The use of conveyor belts to transfer tissue paper webs can be useful for implementing particular unwinding systems, which may also be made automatic or semi-automatic as regards the replacement of an empty parent reel with a standby parent reel.

[0087] One embodiment of a double-station unwinder, which may allow for automatic replacement of an empty reel with a new reel, possibly without stopping the feed of the tissue paper ply, is illustrated in Figs. 12 to 16, which show an operating sequence for replacing an empty reel B2 with a new reel Bl in standby. V2 and VI respectively indicate the tissue paper plies coming from the nearly empty reel B2 and the standby reel B 1.

[0088] In this embodiment, two unwinders are shown, also referred to as unwinding stations, designated with 3 and 5. Contrary to the embodiment of Fig. 11, in Figs. 12 to 16 the unwinding stations 3, 5 are arranged symmetrically with respect to a vertical plane. The unwinder or unwinding station 3 has a peripheral unwinding member 101 comprising a continuous flexible member 103 extending at a higher level relative to a continuous conveyor belt 150 forming part of a conveyor 130. Similarly, the unwinder or unwinding station 5 has a peripheral unwinding member 105 comprising a continuous flexible member 107 at a higher level relative to the underlying continuous conveyor belt 150.

[0089] Within the path of the continuous flexible member 103, a suction box 109 may be provided, to which the portion of the continuous flexible member 103 extending in the feed direction adheres. Similarly, within the path of the continuous flexible member 107, a suction box 111 may be provided, to which the portion of the continuous flexible member 107 extending toward the unwinding station 3 adheres. In practice, the two suction boxes 109 and 111 are located inside the closed paths of the continuous flexible unwinding members 103 and 107, and respective sections of the continuous flexible unwinding members 103 and 107 slide over the box suction surfaces, facing each other symmetrically with respect to the vertical symmetry plane. Between the two suction boxes 109 and 111, guide rollers 103.1 and 107.1 of the continuous flexible unwinding members 103 and 107 are arranged, and between the two guide rollers 103.1 and 107.1, a space is defined through which the ply VI or V2 being dispensed is transferred by gravity onto the continuous conveyor belt 150. Advantageously, the flexible members 103 and 107 may have suction holes to pneumatically connect the respective suction boxes 109 and 111 with the transported ply.

[0090] Mechanical ply-bonding rollers or discs 161 and 163 are positioned below the guide rollers 103.1 and 107.1 and have the function of mechanically ply-bonding the two plies VI and V2 during the step of replacement of an exhausted reel B2 with a new reel B 1.

[0091] A cutting member 165 is provided to cut the tissue paper ply coming from an exhausted reel (in this example, reel B2) to switch to dispensing the ply from the other reel in standby.

[0092] The sequence of Figs. 12 to 16 shows the step of automatic replacement of the nearly exhausted reel B2 with the new reel Bl in standby. In Fig. 12, the reel B2 is dispensing the ply V2 onto the continuous conveyor belt 150, and the reel Bl is stationary. In Fig. 13, the reel Bl starts rotating, dispensing the ply VI toward the continuous conveyor belt 150. In Fig. 14, the bonding rollers 161 and 163 are pressed against each other with the plies VI and V2 interposed between them. The pressure between the rollers 161 and 163 causes the mechanical splicing of the plies VI and V2, either without glue or assisted by a glue or another functional fluid. In Fig. 15, the cutting member 165 cuts the ply V2 coming from the exhausted reel B2. In Fig. 16, the replacement of the exhausted reel B2 with the new reel Bl is complete, and the ply VI. Coming from the reel Bl, is fed to the converting line. The above-described steps can occur automatically, allowing the replacement of the exhausted reel with the new one without interrupting the tissue paper ply feed. The splicing of the plies VI and V2 can be achieved by slowing down the ply V2 and accelerating the ply VI until they reach approximately the same feed speed before performing the mutual splicing. An accumulation area or device for accumulating the tissue paper ply unwound from the new reel during the replacement step may be provided. The accumulation area or device can advantageously be placed between the bonding rollers 161 and 163 and the continuous conveyor belt 150. The accumulation area or device may include a cutting device to cut the tissue paper ply accumulated during the replacement step once the ply from the new reel has been spliced to the ply from the exhausted reel. For the sake of simplicity, the accumulation area or device is not shown.

[0093] Figures 17, 18, 19, 20, and 21 show a variant of embodiment of the doublestation unwinder from Figs. 12 to 16 in an operational sequence for replacing an exhausted reel B2 with a new reel B 1. The structure and operation are substantially the same as described with reference to Figs. 12 to 16, except for the arrangement of the bonding rollers 161 and 163, which in this embodiment are located along or downstream of the continuous conveyor belt 150. This configuration allows easier acceleration of the standby reel (Bl) before splicing. For example, it is possible to replace the exhausted reel B2 with the new reel Bl at a higher feed speed. This is because the standby reel B 1 can accelerate from zero to a peripheral speed as close as possible to the feed speed of the ply V2, discharging the initial part of the ply V2 onto the continuous conveyor belt 150. In this case, the previously described accumulation area or device can be omitted, as the conveyor belt 150 also functions as an accumulation area or device.

[0094] Fig. 22 is a schematic view of another double-station unwinder. The unwinding stations are indicated by the numbers 3 and 5, comprising respectively a peripheral unwinding device 101, comprising a continuous flexible member 103, and a peripheral unwinding device 105, comprising a continuous flexible member 107. A continuous conveyor belt 150 is shown, being part of a conveyor 130.

[0095] In Fig. 22, the ply VI is being fed from the reel Bl. The ply VI unwound from the unwinding station 103 rests on the continuous conveyor belt 150 and is fed by it toward the downstream processing station, for example a printing machine, an embosser, a rewinder, or other. At the point where the ply VI rests on the conveyor belt, a smooth or rough-surfaced idle or motorized guide roller may be provided to facilitate and to stabilize the passage of the ply VI or V2 on the continuous conveyor belt 150. The reel B2 is in standby. The leading edge of the ply V2 from the reel B2 is held by a pair of rollers 203. A collection system 207 is provided below the rollers 203. The unwinding station 3 is provided with analogous components 201 and 205, mirroring the components 203 and 207.

[0096] The numerals 209 and 213 designate cutting members for the ply VI; the numerals 211 and 215 designate symmetrical cutting members for the ply V2.

[0097] The numerals 231 and 233 indicate splicing members, such as pressure rollers for mechanical bonding of the plies VI and V2.

[0098] The continuous flexible members 103 and 107 are driven around guide rollers and contain suction boxes. More in particular, the numeral 109 indicates a suction box within the closed path defined by continuous flexible member 103, and the numeral 111 indicates a suction box within the closed path defined by continuous flexible member 107. 217 and 218 indicate guide rollers of the continuous flexible member 103, and 219 and 220 indicate the symmetrical guide rollers for the continuous flexible member 107. In this case again, the continuous flexible members 103 and 107 may advantageously have suction holes.

[0099] The operation of the double-station unwinder is substantially similar to that described in EP 1601601 and is briefly summarized below. Unlike the known unwinder, in this case, the feeding ply (V 1 or V2) is laid onto the continuous conveyor belt 150 to be transferred without mechanical pulling stress toward the downstream stations. Moreover, innovatively, each unwinding station comprises suction boxes 109 and 111 within the continuous flexible unwinding member 103, 107. The operation during the step of replacing an exhausted reel with a new standby reel is as follows. The feeding ply (e.g., the ply VI) is transferred by gravity onto the conveyor belt 150 and is fed downstream. When the dispensing reel (Bl) is nearly exhausted, the standby reel (e.g., B2) is accelerated from zero to a speed close to or equal to the normal dispensing speed. Simultaneously, the nearly exhausted reel may be decelerated. During the acceleration step, the ply V2 from the standby reel accumulates in the accumulation area or system 207. This system may comprise a chute, as schematically shown, or a winding mandrel, or other.

[0100] When the linear speeds of the plies VI and V2 are substantially equal, the plies VI and V2 are spliced together by the cutting members 213, 215 and the splicing members 231 and 233, the tail edge pf the ply VI is cut by the cutting member 209, and the leading edge of the ply V2, accumulated during the acceleration, is cut by the cutting member 215.

[0101] The symmetrical members are activated when the ply V2 needs to be replaced with the ply V 1.

[0102] During unwinding, the suction boxes 109, 111 facilitate the advancement of the plies VI and V2. Moreover, they enable the easy introduction of the leading edges of the plies V 1 and V2 when their respective reel Bl or B2 is loaded into the unwinder, and the ply leading edge shall be guided toward the splicing area, arranged between the two unwinding stations 3 and 5.

[0103] Fig. 23 shows a variant of the double-station unwinder from Fig. 22. The difference lies in the different paths of the continuous flexible members 103, 105. The different arrangement of the guide rollers 218, 220, and 217, 219 facilitates the guidance and introduction of the plies VI and V2 up to the above of the splicing area, simplifying and enabling the automation of the leading edge introduction. Fig. 24 shows a condition where the positions of the rollers 231, 233 has been modified to further facilitate the step of introduction of the leading edges of the respective plies VI, V2.

[0104] Fig. 25, 26, and 27 show three variants of a further embodiment of a doublestation unwinder similar to that of Fig. 11. Equal numbers in Fig. 25, 26, and 27 indicate parts equal or equivalent to those illustrated in Fig. 11 and previously described. 150 designates a continuous conveyor belt, forming part of the conveyor 130. In the variant of Fig. 25, the ply VI from the reel Bl is transferred from the continuous flexible unwinding member 103 directly onto the continuous conveyor belt 150, as the upper branch of the latter is at the level of the active exit branch of the continuous flexible member 103, which, as shown in Fig. 11 and in Figs. 12 to 24, constitutes part of the conveyor 130. The numeral 303 designates an auxiliary conveyor belt extending from the flexible continuous member 107 to a device for splicing the plies VI, V2, for example a pair of mechanical splicing rollers. The splicing device is indicated with 301 and is arranged near the outlet of the conveyor belt 150.

[0105] With this arrangement, it is possible to simultaneously feed the plies VI, V2 during the transition step from feeding one of the plies VI, V2 to feeding the other of the two plies VI, V2 when the first one is exhausted.

[0106] To perform splicing without stopping the feed of the tissue paper ply, the splicing device 301 may be combined with cutting members 307, 309 and accumulation members 311, 313. The arrangement operates as follows. Assuming that the reel Bl is nearly exhausted and the reel B2 is on standby, when the ply VI shall be replaced with the ply V2, the reel B2 is accelerated. The leading edge of the ply V2, previously inserted into the accumulation member 313, begins to be wound around the accumulation member 313, for example a winding mandrel, to allow the increase of the feed speed of the ply V2. At the same time, the ply VI may be decelerated, if appropriate. When the ply VI and the ply V2 have reached the same speed, the two plies are spliced by closing and pressing together the splicing rollers of the device 301. The cutting member 309 cuts the leading edge of the ply V2 that was accumulated during the acceleration phase.

[0107] A symmetrical sequence is carried out when the ply V2 is nearly exhausted and must be replaced with the ply VI. The tail edge of the exhausted ply may be suitably cut by other cutting members or completely unwound from the respective reel.

[0108] The embodiment of Fig. 26 is substantially the same as Fig. 25, except that the continuous conveyor belt 150 extends to the rear of the unwinding station 3. Moreover, in Fig. 26, each continuous flexible member 103, 107 comprises within its path a second suction box 109A, 111A, respectively. The arrangement allows the reels Bl, B2 to be unwound in either clockwise or counterclockwise directions.

[0109] A further variant of embodiment is illustrated in Fig. 27, where identical reference numbers indicate parts identical to those described above with reference to Figs. 25 and 26. The main difference between Fig. 27 and Figs. 25, 26 lies in the different method of splicing the plies, for example using a glue. The gluing device is designated by 302, 304 and may be realized as described with reference to Fig. 3. The reference numbers 321 and 323 indicate cutting members for cutting the tail edge of the tissue paper ply (VI or V2) that is nearly exhausted.

[0110] In the embodiments of Figs. 12 to 27, each peripheral unwinding member, comprising a continuous belt-shaped member, constitutes a continuous conveyor belt of a conveyor transferring the respective tissue paper ply outside of the unwinder toward a downstream station or operating unit.

[oni] The conveying of the ply outside of the unwinder is facilitated by the presence of the respective suction box, but it is also possible to omit the suction box, for example in less high-performance embodiments.

[0112] Whilst the peripheral unwinding members of the prior art unwinders are constituted of two belts with a width much smaller than the width of the unwound ply, i.e., the axial dimension of the reels, according to the embodiments described herein, for better control of the ply, the continuous flexible members forming the peripheral unwinding member preferably have a width at least equal to the width of the ply to be unwound and therefore to the axial length of the respective reel. For example, the width of each continuous belt-shaped member may be at least equal to 70%, or at least equal to 80%, or at least equal to 85% or 90% of the axial dimension of the reel to be unwound. Preferably, the continuous belt-shaped member unwinding a single reel is constituted by a single belt, but it is also possible that it is constituted by two or more adjacent belts. In other cases, the continuous flexible members forming the peripheral unwinding member or the conveyor belts transporting the ply or plies from an upstream unit to a downstream unit may have a width greater than the width of the ply to be unwound, in order to provide greater safety and control during the ply transport.

[0113] As described above, in advantageous embodiments, the unwinder is of the double type, i.e., it comprises two unwinders or unwinding stations, which in some cases may be arranged symmetrically to each other relative to a plane along which the ply path extends. The double-station unwinder may comprise a splicing device adapted to perform the splicing of a ply coming from an exhausted reel and a ply coming from a reel on standby. An exhausted reel is not necessarily a reel whose web is nearly depleted but may be a reel that shall be replaced due to changes in the production parameters, for example, the type of tissue paper ply to be unwound and processed, or in other cases a reel that is excessively defective.

[0114] As described above, the double-station unwinders may comprise cutting devices or members. Typically, a first cutting member may be provided to cut the tissue paper ply from one of the two stations, and a second cutting member or cutting device to cut the tissue paper ply from the other station.

[0115] In some embodiments, the double-station unwinder may comprise an accumulation area with accumulation members to accumulate the tissue paper ply unwound during a transition phase in which a new reel is accelerated to deliver the web material at a speed equal to or substantially equal to the feed speed of the web material unwound from the other reel.

[0116] When an accumulation area or accumulation member for the web material or tissue paper ply unwound from each unwinding station is provided, four cutting devices may be provided: two for cutting the web material along a path between the splicing device and the accumulation area, and two for cutting the web material upstream of the splicing device.

[0117] In some embodiments of double-station unwinders, it is possible to provide a first path for the ply or web material unwound from the first unwinding station and a second path for the ply or web material unwound from the second unwinding station, the first and second paths being at least partially overlapping. See, for example, Figs. 25, 26 and 27.

[0118] In some embodiments, the double-station unwinder may comprise a conveyor belt between the cutting device(s) and the splicing device, as shown for example in Figs. 17, 18 and 19.

[0119] In some embodiments of double-station unwinders, a conveyor belt may be arranged beneath at least one of the two unwinding stations. In some embodiments, particularly that of Fig. 26, a conveyor belt is arranged beneath both unwinding stations. This configuration may also be provided in the embodiments from Fig. 12 to Fig. 21 by extending the continuous conveyor belt 150 beneath both stations and unwinding the tissue paper ply VI in a clockwise direction, for example, by using an unwinding station 3 of Fig. 26.

Claims

1. A tissue paper converting line, wherein the converting line includes a plurality of sequentially arranged operating units, and wherein a first conveyor is provided between an upstream operating unit and a downstream operating, the conveyor including at least one endless belt configured to transfer a ply of tissue paper from the upstream operating unit to the downstream operating unit.

2. The line of claim 1, wherein the first conveyor includes two sequentially arranged endless belts.

3. The line of claim 1 or 2, wherein the upstream operating unit is selected from the group including: an unwinder; a ply bonding unit; an embossing unit.

4. The line of claim 1 or 2, wherein the upstream operating unit comprises an unwinder; wherein the unwinder includes an unwinding device adapted to transmit a rotational torque to a reel arranged in the unwinder; wherein the unwinding device includes: a central unwinding member adapted to transmit a rotational torque to a core, around which the reel is wound; or a peripheral unwinding member, adapted to transmit a rotational torque to the reel by friction between the endless unwinding member and a side surface of the reel; or a combination of a central unwinding member and a peripheral unwinding member.

5. The line of claim 4, wherein the peripheral unwinding member includes an endless motorized flexible member, which constitutes the endless belt of the first conveyor.

6. The line of any one of the preceding claims, wherein the downstream operating unit is selected from the group including: a ply bonding unit, an embossing unit, a rewinder; an interfolding machine; a folding machine.

7 The line of claim 1 or 2, wherein the upstream operating unit includes a first unwinder; wherein the line includes a second unwinder; wherein a second conveyor is provided between the second unwinder and the downstream operating unit, the second conveyor including at least a second endless belt configured to transfer a second ply of tissue paper from the second unwinder to the downstream operating unit; wherein the first conveyor and the second conveyor are overlapping in at least a section of a feed path toward the downstream operating unit.

8. The line of claim 7, wherein the second conveyor includes an additional second belt, the second belt and the additional second belt being arranged sequentially; and wherein the first conveyor and the second conveyor are overlapping at least in an area of transition from the first second belt to the additional second belt.

9. The line of claim 7 or 8, wherein the downstream operating unit is selected from the group including: an embossing unit and a ply bonding unit; and wherein the first conveyor and the second conveyor are adapted to convey the tissue paper ply and the second tissue paper ply to the downstream operating unit, which is adapted to bond the tissue paper ply and the second tissue paper ply together.

10 The line of claim 9, wherein the bonding unit comprises: a first endless bonding belt, forming part of the first conveyor; a second endless bonding belt, forming part of the second conveyor; wherein the first bonding belt and the second bonding belt are pressed against each other along a common path where the tissue paper ply and the second tissue paper ply move forward; a functional fluid dispensing device, provided upstream of the common path and adapted to dispense functional fluid to at least one of the tissue paper plies.

1 1. The line of claim 9 or 10, further comprising an additional operating unit provided following the downstream operating unit in the line forward direction; and wherein a subsequent conveyor extends from the downstream operating unit to the additional operating unit provided following the downstream operating unit, the subsequent conveyor including at least one subsequent endless belt.

12. The line of claim 11, wherein the second operating unit comprises: a rewinder; an interfolding machine; a folding machine.

13. The line of any one of claims 7 to 12, wherein the first unwinder includes a first endless unwinding member adapted to transmit a rotational torque to a reel arranged in the first unwinder by friction between the first endless unwinding member and a side surface of the reel; wherein the first endless unwinding member constitutes the endless belt of the first conveyor that extends from the first unwinder to the downstream operating unit; wherein the second unwinder includes a second endless unwinding member adapted to transmit a rotational torque to a reel arranged in the second unwinder by friction between the second endless unwinding member and a side surface of the reel; and wherein the second endless unwinding member constitutes the second endless belt of the second conveyor that extends from the second unwinder to the downstream operating unit.

14. The line of any one of the preceding claims, wherein at least one of the endless belts includes at least one suction portion.

15 The line of any one of the preceding claims, including at least one measurement device associated with at least one of endless belts, wherein the measurement device is adapted to detect an accumulation of a respective tissue paper ply on, or upstream of, the endless belt.

16. The line of claim 15, wherein the measurement device is a non-contact measurement device.

17. The line of claim 16, wherein the measurement device includes a sensor member selected from the group including: a laser measurement device; a video camera; a capacitive sensor; a proximity sensor; a roller with a motion detector.

18. The line of any one of claims 15 to 17, wherein the measurement device is functionally connected to a control unit adapted to adjust a feed speed of at least one of the endless belts in order to eliminate an accumulation of tissue paper.

The line of any one of the preceding claims, wherein the first conveyor extends from the upstream operating unit to the downstream operating unit.

2.0. The line of any one of the preceding claims, wherein the conveyor belt has an inlet at a first level and an outlet at a second level higher than the first level.

2.1. An unwinder for unwinding reels of web material, comprising: a first unwinding station; and in the unwinding station, a first peripheral unwinding member comprising a first continuous flexible member defining a first closed path; wherein the first continuous flexible member constitutes a first endless conveyor belt configured to transfer a web material toward the outside of the first unwinding station.

22. The unwinder of claim 21, further comprising: a second unwinding station; and in said second unwinding station, a second peripheral unwinding member comprising a second continuous flexible member defining a second closed path; wherein the second continuous flexible member constitutes a second endless conveyor belt configured to transfer a web material toward the outside of the second unwinding station.

23 The unwinder of claim 22, further comprising a splicing device for splicing together a web material from a reel arranged in the first unwinding station and a web material from a reel arranged in the second unwinding station.

24. The unwinder of claim 22 or 23, further comprising a first cutting device to cut a web material coming from a reel arranged in the first unwinding station and a second cutting device to cut a web material coming from the second unwinding station.

25 The unwinder of claim 22, 23 or 24, where the first unwinding station and the second unwinding station are positioned symmetrically with respect to each other.

26. The unwinder of any one of claims 22 to 24, further comprising an accumulation member to accumulate the web material unwound during an exchange step, in which a waiting reel, placed in one of the first and second unwinding stations, is accelerated to feed the web material at a speed equal to, or substantially equal to, the speed of feeding a web material unwound from a nearly exhausted reel placed in the other of the first and second unwinding stations.

2.7. The unwinder of any one of claims 22 to 25, comprising a first path for a web material unwound from the first unwinding station, and a second path for the web material unwound from the second unwinding station; wherein the first path and the second path are at least partially overlapping.

28 The unwinder of any one of claims 22 to 27, comprising a suction box within a closed path defined by each unwinding member.

29 A converting line according to one or more of claims 1 to 20, comprising an unwinder according to one or more of claims 21 to 28.