PLANT AND PROCESS FOR THE PRODUCTION OF PAPER ROLLS

Abstract

Process for the production of paper rolls, including a step of producing logs (L) of paper material by winding a predetermined amount of paper web (W) about a tubular core (C) oriented transversely with respect to a direction (PP) of entering of the paper web (W) in a rewinder (R) in which the winding is executed, and a step of transverse cutting of the logs (L) to obtain rolls (R) of predetermined length. The cores (C) are produced by a tube-forming machine (T) whose position is intercepted by the direction (PP) of the paper (W) entering the rewinder®.

Claims

1. A process for producing paper rolls, the process comprising: producing logs of paper material by winding a predetermined amount of paper web about at least one tubular core oriented transversely with respect to a direction of entering of the paper web in a rewinder (R) in which said winding is executed; and cutting the logs transversely to obtain rolls of predetermined length, said at least one tubular core being produced by a tube-forming machine having a position intercepted by the direction of the paper entering the rewinder.

2. A process according to claim 1, further comprising: transporting the logs from a rewinder that produces the logs toward a cutting-off machine that cuts the logs transversely and said transporting comprises handling the logs along a path comprising a lateral deviation, so that, as the logs advance, the logs are subjected to said lateral deviation.

3. A process according to claim 2, wherein in a plan view, the path comprises a S-shaped part.

4. A process according to claim 2, wherein said path comprises a part that passes beneath the tube-forming machine which produces the at least one tubular core.

5. A process according to claim 2, wherein the path comprises a part that passes over the tube-forming machine which produces the at least one tubular core.

6. A process Precess according to claim 2, further comprising: accumulating the logs in an accumulator for logs before their entry the logs enter into the cutting-off machine, so that the path is comprised between the rewinder and the accumulator of the logs and the fatter accumulator supplies the logs to the cutting-off machine.

7. A process according to claim 1, wherein the at least one tubular core is produced at a point located downstream of the rewinder.

8. A plant for producing paper rolls, the plant comprising: a rewinder producing logs of paper material wound around at least one tubular core oriented transversely with respect to a direction of entering of a paper web in the rewinder; a tube-forming machine that produces the at least one tubular core, the tube-forming machine being located at a position that is intercepted by the direction of the paper web entering in the rewinder.

9. A plant according to claim 8, further comprising: a cutting-off machine that cuts the logs transversely to obtain rolls of predefined length; and a transport unit adapted to move the logs from the rewinder toward the cutting-off machine, wherein the transport unit comprises an inlet section and an outlet section for the logs, the transport unit further comprising a part between the inlet section and the outlet section adapted to impose a lateral deviation to the logs while the logs advance towards the outlet section, the outlet section of the transport unit being laterally offset by a predetermined value with respect to the inlet section.

10. A plant according to claim 8, wherein, in a plan view, the transport unit comprises a S-shaped part.

11. A plant according to claim 8, wherein the transport unit comprises a part that passes beneath a tube-forming machine which produces the at least one tubular core.

12. A plant according to claim 8, wherein the transport unit comprises a part that passes over a tube-forming machine which produces the at least one tubular core.

13. A plant according to claim 9, further comprising: an accumulator for logs upstream of the cutting-off machine, so that said transport unit is positioned between the rewinder and the accumulator for logs and the accumulator supplies the logs to the cutting-off machine.

14. A plant according to claim 8, wherein the tube-forming machine is located downstream of the rewinder with respect to the direction followed by the paper web entering the rewinder.

15. A plant according to claim 8, wherein the tube-forming machine is positioned downstream of the rewinder and upstream of the cutting-off machine.

16. A plant according to claim 8, wherein the tube-forming machine is positioned upstream of the rewinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the drawings:

[0010] FIG. 1 is a schematic top view of a plant in accordance with the present invention;

[0011] FIG. 2 is a schematic side view of the plant shown in FIG. 1;

[0012] FIG. 3 is a view similar to that of FIG. 2 but it refers to a further embodiment of the plant;

[0013] FIG. 4 is a view showing the path of the cores and the logs in the area between the rewinder and the tube-forming machine;

[0014] FIG. 5 is a diagram showing the movements of the cores in the area between the rewinder and the tube forming machine;

[0015] FIG. 6 is a view showing the path of the logs and the cut rolls in the area between the accumulator for the logs and the cutting-off machine;

[0016] FIG. 7 is a schematic view representing a part of the logs transport unit (LT);

[0017] FIG. 8 is a schematic view representing a part of the logs transport unit (LT);

[0018] FIG. 9 is a schematic view representing a part of the logs transport unit (LT); and

[0019] FIG. 10 is an enlarged detail view of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Reduced to its basic structure and with reference to the attached drawings, a plant for the production of paper rolls (for example, rolls of toilet paper or rolls of kitchen paper) in accordance with the present invention typically comprises: [0021] a paper unwinding station (UP) with one or more unwinders (in the example, the unwinders are two in number and are indicated by references “U1” and “U2”) that support a corresponding number of paper reels (R1, R2) from each of which a paper ply (V1, V2) unwounds; [0022] a unit (EG) for coupling of the paper plies coming from the unwinding station (UP), an embossing in which said plies can be embossed and joined together by gluing to form a two-plies paper web (W); [0023] a rewinder (R) which on side receives the paper web (W) and on another side receives the tubular cores on which the paper web is wound to form the logs (L); [0024] a tube-forming machine (T) that produces the tubular cores; [0025] a first accumulator (CS), which receives and accumulates the cores produced by the tube- forming machine (T) and feeds the rewinder (R); [0026] a second accumulator (LS) which receives the logs produced by the rewinder (R); [0027] a transport unit (LT) which receives the logs outgoing from the rewinder (R) and transports them to the second accumulator (LS); [0028] a cutting-off machine (CM) which receives the logs coming from the second accumulator (LS) and subdivides them into rolls of lesser length.

[0029] The unwinders (U1, U2) allow the unwinding of the plies (VI, V2) from the reels (B1, B2). Said plies are embossed and glued in the station (EG) that produces the web (W) formed by the embossed and glued plies. The web feeds the rewinder (R) that provides for winding a predetermined amount thereof on each core (C) coming from the first accumulator (CS) and produced by the tube-forming machine (T). The core (C) allows the winding of the web (W) around an axis defined by the longitudinal axis of the same core (C). The logs thus produced in the rewinder (R) reach the conveyor (LT) which conveys them up to the second accumulator (LS). The latter feeds the cutting-off machine (CM) that cuts the logs to obtain rolls of the desired length.

[0030] The tube-forming machine (T) and the cutting-off machine (CM) are oriented transversely to the path (PP) followed by the paper web. Therefore, the cores produced by the tube-forming machine (T) and exiting from the latter move along a direction substantially perpendicular to said path (PP) and the rolls produced by the cutting-off machine (CM) go out from the latter also in a direction substantially perpendicular to said path (PP).

[0031] The first accumulator (CS) receives the cores produced by the tube-forming machine (T) by means of a vertical conveyor (VC).

[0032] The unwinders (U1, U2), the embossing and sizing unit, the rewinder, the accumulator for the cores, the accumulator for the logs, the tube-forming machine, the means for transferring the cores from the tube-forming machine to the first accumulator, the means for transferring the logs from the second accumulator to the cutting-off machine, and the cutting-off machine can be of the type normally used for the production of paper rolls. EP0454633 and U.S. Pat. No. 6,715,709 disclose rewinders, the entire contents of EP0454633 and U.S. Pat. No. 6,715,709 are herein incorporated by reference; WO2011/089634 discloses an accumulator for tubular cardboard cores, the entire contents of WO2011/089634 are herein incorporated by reference; WO2004/014641 discloses a tube-forming machine, the entire contents of WO2004/014641 are herein incorporated by reference; U.S. Pat. No. 3,926,299 and U.S. Pat. No. 3,762,582 disclose devices for handling and storage of paper logs, the entire contents of U.S. Pat. No. 3,926,299 and U.S. Pat. No. 3,762,582 are herein incorporated by reference.

[0033] According to the example shown in FIG. 2, the tube-forming machine (T) is placed downstream of the rewinding machine (R) and is positioned on a platform (1) under which is arranged the transport unit for the logs (LT). The cutting-off machine (CM) is placed downstream of the second accumulator (LS). Since the transport unit (LT) imposes a lateral deviation to the logs while they move towards the second accumulator (LS), the cutting-off machine (CM) may be positioned within the outline “A” of the production line, that is, within line formed by the unwinders, the embossing-sizing unit, the rewinder, the first accumulator and the tube-forming machine. In the example, the transport unit (LT) determines a deviation (LD) of the logs to the left while the logs advance along the path comprised between the rewinder (R) and the second accumulator (LS). Thanks to the lateral deviation imposed to the logs that move towards the second accumulator (LS), the cutting-off machine (CM) can be arranged as described above and this reduces the overall width of the overall production line compared to the traditional plants that provide for a straight advancement of the logs between the rewinder and the accumulator for the logs. When seen from above, according to the example shown in the drawings, the transport unit for the logs (LT) is “S” -shaped. It is understood that, if required, when seen from above the transport unit of the logs (LT) can comprise a first rectilinear section, a second “S”-shaped section, and a third straight section. Otherwise, when seen from above the transport unit for the logs (LT) may include a “S”-shaped section preceded or followed by a straight section. Again, when seen from above the transport unit for the logs is rectilinear, oriented with a predetermined angle with respect to the above-mentioned path (PP). In any case, the output section of the transport unit for the logs (LT) is laterally displaced with respect to the centerline of the rewinder of a predetermined amount “B”.

[0034] It is observed that with the current production requirements, characterized by high operating speeds (production rate of at least 60 logs per minute), the lateral displacement of the logs (not combined with the advancement) would require a conveyor surface with an extremely high friction coefficient which, however, implies damages to the surface of the logs. In the past, such a solution has been adopted but for lower production rates (about 20 logs per minute). The combination of the advancement and the lateral displacement of the logs implies a lower speed lateral component without imposing any reduction of operating speeds.

[0035] Referring to the diagram in FIG. 1, in an experimental facility built by the applicant the dimension “A” was about 12.00 (twelve) meters and the dimension “B” was 2.265 (two-point-two-hundred-sixty-five) meters. The experimental plant was intended to produce logs having a maximum size of 2850 mm.

[0036] With reference to the example shown in FIG. 3, the machines arrangement (in particular, the arrangement of the unwinders, the embossing-sizing unit, the rewinder, the accumulators and the cutting-off machine) is the same as in the previous case but the tube-forming machine (T) is on the same base of the other machines and the transport unit (LT) has an ascending section for passing over the tube-forming machine (T). Also in this case, the transport unit (LT) obliges the logs to deviate sideways while advancing towards the second accumulator (LS).

[0037] In FIG. 4 and FIG. 6, where the constructive details of the individual machines (in particular, the constructive details of the rewinder and the first and second accumulator) are not illustrated, it is shown the path of the cores (C) and the logs (L) in the area between the rewinder (R) and the tube-forming machine (T).

[0038] In particular, FIG. 4 shows: a first horizontal translation (1C) of the cores leaving the tube-forming machine above the transport unit (LT); a second horizontal translation (2C) of the cores (C) when entering the first accumulator (CS), the second translation (2C) being orthogonal to the first (1C); a third ascending vertical movement (3C) of cores (C) in a stage prior to their exit from the first accumulator (CS) ; a fourth descending vertical movement (4C) of cores (C) when leaving the first accumulator; a fifth horizontal translation (5C) of cores (C) in the direction opposite to the first (1C); a sixth horizontal translation (6C) of cores (C) when they enter the rewinder (R); the transport unit (LT) that determines the advancement and the simultaneous lateral deviation of the logs (L). FIG. 5 shows the overall path followed by cores (C).

[0039] The translation (1C) is determined by the tube-forming machine (T) that, while producing the cores (C), advances them, that is, forces them to move as shown in FIG. 4 (arrow “1C”). The translation (2C) is determined by the inlet section of the first accumulator (CS) which is normally provided with an input section that picks up the cores from the tube-forming machine (T). Within the first accumulator (CS), the cores are supported by shaped bars that move along a trajectory consisting of a succession of vertical and horizontal sections. The translation (3C) is the last run of the cores (C) within the first accumulator (CS). The translation (4C) takes place at the exit of the cores (C) from the first accumulator (CS) and ends with the deposition of the same cores on a belt conveyor (CW) that receives and transports the cores determining the fifth translation (5C). The sixth translation (6C) is determined by the fact that the conveyor (CW) is provided, in a per se known manner, of inclined cylindrical rollers (CR) that determine the sliding of the cores (C) towards the rewinder: in fact movements 5C and 6C are combined even if in the drawings they are represented as separated movements for the sake of clarity.

[0040] In FIG. 6, where the constructive details of the individual machines (in particular, the constructive details of the rewinder, the second accumulator and the cutting-off machine) are not illustrated, it is shown the path of the logs (L) in the area between the rewinder (R) and the cutting-off machine (CM).

[0041] In particular, FIG. 6 shows, downstream of the transport unit (LT) that, as mentioned above, moves the log (L) along an advancing path comprising a lateral deviation: a first ascending vertical translation (1L) of logs (L) when entering the second accumulator (LS); a second descending vertical movement (2L) of logs (L) in a stage prior to their exit from the second accumulator (LS); a third horizontal translation (3L) of the logs (L) when exiting from the second accumulator (LS); a fourth horizontal translation (4L), orthogonal to the third (3L), of the logs in a step of advancing towards the blade of the cutting-off machine (CM). In FIG. 6 the rolls produced by the cutting of the log (L) by means of the cutting-off machine (CM) are denoted by reference “RO”. Inside the second accumulator (LS), the logs (L) are supported by shaped bars that move along a trajectory consisting of a succession of vertical and horizontal sections. In its terminal part (part facing the cutting-off machine), the second accumulator (LS), that can be of the known type comprising a series of log-supporting bars (PL) moved by chains, is extended horizontally above the channels (CT) on which the logs normally slide when entering the cutting-off machine. Between the log-supporting bars (PL) and the channels (CT) are interposed corresponding so-called pre-load channels (CC) that receive the logs from the log-supporting bars of the accumulator (LS) and discharge them onto the channels (CT) of the cutting-off machine in synchronism with the pushers acting on the logs in the cutting-off machine according to a process known per se.

[0042] The transport unit for the logs (LT) that makes the logs to deviate laterally while they advance towards the cutting-off machine (CM) allows to make use of conventional machines for making the plant and, at the same time, allows the positioning of the cutting-off machine (CM) and the tube-forming (T) within the outline of the production line arranged upstream and comprising the rewinder (R), the embossing-sizing unit (EG) and the unwinding unit (UP).

[0043] The transport unit for the logs (LT) consists, for example, of three motor-driven loop chains constituted by meshes (MC) joined together by ball joints (SM), contained in guides (GC) having the desired orientation and equipped, at regular intervals, with blades (PC) that in operation are destined to be in contact with the back of the logs.

[0044] In practice, the transport unit (LT) forms a flow diverter for the logs (L), in the sense that it makes possible to divert the flow of logs exiting from the rewinder and place the cutting-off machine (CM) with its feeding channels (CT) also in an offset position with respect to the rewinder.

[0045] As shown in the drawings, the tube-forming machine (T) is located within the outline of the production line formed by the unwinders, the embossing-sizing unit and the rewinder.

[0046] Compared to a conventional plant, in which the tube-forming machine (T) is external to the production line formed by the unwinders, the embossing-sizing unit and the rewinder, there is a considerable saving of ground area in manufacturing the logs production plant. For example, for equal maximum size of the logs (logs length equal to 2850.00 mm) and hence the same machines used, in a traditional system the dimension “A” previously mentioned assumes a value of about 20 meters. By contrast, as mentioned earlier, positioning the tube (T) as in the diagram of FIG. 1, that is, by placing the tube-forming machine (T) such that it is intercepted by the direction (PP) that represents the path of the paper (W) from the unwinders to the rewinder, the dimension “A” has a value almost halved.

[0047] It is understood that, where the accumulation of the logs (L) upstream of the cutting-off machine (CM) is not required, the transport unit (LT) directly connects the rewinder (R) with the cutting-off machine (CM).

[0048] The tube-forming machine (T) can be placed downstream of the rewinder and upstream of the cutting-off machine, or upstream of the rewinder.

[0049] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.