Method in reeling, and a reel-up

Abstract: The invention relates to a method in reeling in which a web (W) to be reeled up passes over a reeling cylinder (15) onto a reeling drum, driven by a centre drive (44, 54) and placed on rails (10) and on which a machine roll (20) is being formed, and in which, when the machine roll (20) becomes full, a new reeling drum (22) is brought into a stand-by position to take over the web from the reeling cylinder. Before the web (W) is taken over by the new reeling drum (22) a press roll (35) is brought into contact with the machine roll (20) to produce an additional nip to prevent access of air into the machine roll (20). The invention also relates to a reel-up to be used for the method.

Description: The invention concerns a method in reeling, as well as a reel-up suitable for use at the method according to the invention. A method and apparatus for reeling of web is known from prior art as described in EP-A-0330 169 in which a web to be reeled up passes over a reeling cylinder onto a reeling drum and, when the roll is full and the web should be transferred to a new reeling drum, this new reeling drum is pre-accelerated to the web speed. The new reeling drum is then placed in contact with the reeling cylinder and the web is transferred onto the new reeling drum before the "old" reeling drum with its roll is removed along the rails. The new reeling drum is then lowered onto the rails. This change of position and change of nip is disadvantageous. A similar machine is known from the document US-A-3 258 217 but in this machine the new reeling drum is not pre-accelerated, it does not have a centre drive and only obtains its speed from contact with the web. The document DE-B-1 101 938 discloses a method and apparatus for the reeling up of web in which a new reeling drum is provided with its own centre drive. In all of these documents there is a disadvantageous change of position of the new reeling drum after the web has been transferred to it. The document WO 90/000513 relates to another kind of reel-up. According to this document the web roll core, i.e. the web roll, that is being formed, rests during the reeling up on two supporting rollers and is supported onto guide means from the roll core. While guided by the guide means, the centre of the growing web roll can rise higher when the reeling up makes progress. One of the supporting rollers is supported by lever arms by which said roller can be moved apart from the surface of the formed web roll for carrying out the change of a web roll core. Hence, the teachings of WO 90/000513 do not disclose anything about bringing a roller into contact with a full web roll, but, on the contrary, teaches moving a roller apart from the formed web roll. In reeling, for example in Pope-typing reeling, the exchange from the primary forks onto the secondary forks causes discontinuity in the reeling of the web, with resulting broke in the paper roll bottom, for which reason the situation of exchange ought to be eliminated and especially the initial stage in the reeling should take place in a standardized situation. The main roblems in the exchange in reeling has been solved by the invention defined in EP-A-0 483 092 (our European patent application No. 91850260.0), from which the present application has been divided. The object of the invention is to further improve the structure of the roll. When a full machine roll is separated from the face of the reeling cylinder, there is no nip contact. In such case, air tends to enter into the machine roll through the gap between the full machine roll and the arriving web, causing possible deterioration of the quality of the machine roll. In the solution in accordance with the invention, this can be prevented by, before the transfer of the machine roll, fitting an additional nip, which is placed at the point at which the arriving web meets the mantle of the machine roll, said nip preventing access of air into the machine roll. In the following, the reel-up in accordance with the invention will be described in more detail with reference to the figures in the accompanying drawing, the invention being, however, not supposed to be confined strictly to the illustrations in said figures. Fig. 1 is a schematic illustration of the stage in the reeling arrangement of the invention in which the new reeling drum is brought into the stand-by position. Fig. 2 is a schematic illustration of the stage in the reeling arrangement of the invention in which the new reeling drum is accelerated to the web speed. Fig. 3 is a schematic illustration of the stage in the reeling arrangement of the invention in which the full machine roll is transferred to the exchange position. Fig. 4 is a schematic illustration of the stage in the reeling arrangement of the invention in which the new reeling drum is connected to the reeling. Fig. 5 is a schematic illustration of the stage in the reeling arrangement of the invention in which the full machine roll is slowed down and the transfer device and the centre drive are shifted to the new reeling drum. In the stage shown in fig. 1, the first roll, i.e. the reeling cylinder 15, revolves in the direction indicated by the arrow SI, and the web W is reeled onto the second roll, i.e. the reeling drum 20. The web W is reeled onto the reeling drum 20 by the intermediate of the reeling cylinder 15 through the nip N. The reeling drum revolves in the direction indicated by the arrow S2. The reeling drum 20 is mounted on rails 10, and it is connected to a centre drive 44 and to the reeling-drum transfer device 45. By means of a support device 40 and a cylinder 41, it is ensured that the reeling drum is not detached and that the reeling drum 20 does not vibrate during reeling. The machine roll 20 is almost full and, by means of the transfer members 32, a new reeling drum 22 has been brought to the stand-by position. A press roll 35 is in a stand-by position at the proximity of the machine roll 20. In the stage shown in fig. 2, the machine roll 20 formed on the rails 10 is almost full. When the machine roll 20 becomes full, the new reeling drum 22 is brought, by means of auxiliary forks or equivalent transfer members 32, to the stand-by position, and the new reeling drum 22 is accelerated to the web speed. The press roll 35 has been brought into contact with the machine roll 20 to produce an additional nip soas to prevent access of air into the machine roll 20. The press roll 35 is brought into contact before the machine roll 20 is separated from the reeling cylinder 15. As is shown in fig. 3, the reeling-drum 20 transfer device 45, which is mounted on the rails 10 and synchronized between the operating side and the driving side, transfers the machine roll 20, which is connected to the centre drive 44, to the exchange position. The necessary tension of the web is produced by means of a torque M at the roll centre. The support device 40 with its cylinder 41 is separated from the engagement with the machine roll 20 and is returned to its position ready to receive a new reeling drum 22, which is transferred onto the rails 10 by means of transfer members, e. g. auxiliary forks 32. As shown in fig. 4, the new, pre-accelerated reeling drum 22 is lowered onto the rails 10, and the exchange is carried out by means of normal prior-art methods. The new reeling drum 22 has been brought into contact with the cylinder 15, and the new reeling drum revolves at the web speed in the direction indicated by the arrow S3. The support device 40 and the cylinder 41 are in contact with the new reeling drum 22. The full machine roll continues to revolve in its exchange position inthedirection indicated by the arrow S2, in engagement with the centre drive 44 and the transfer device 45. By means of the cylinder 41 or equivalent, the reeling drum 22 is pressed/locked with such a force that the reeling drum 22 is not detached, and the friction force between the rolls 48, 47 or friction faces or equivalent and the face of the reeling drum 22 prevents vibrations of the reeling drum 22 during reeling. As is shown in fig. 5, the full machine roll 20 is slowed down and the reeling-drum transfer device 45 is brought to the new reeling drum 22, and the centre drive 44 is transferred to the new reeling drum 22. The auxiliary forks 32, i.e. the transfer members, have been returned to their initial position, and the reeling takes place onto the new reeling drum 22. The transfer device 45 and the centre drive 44 are returned to the new reeling drum 22 for the next exchange. In the stages shown in figs. 2 to 4, the press roll 35 has been employed to prevent access of air into the machine roll 20. By means of the press roll 35, it is also possible to act upon the structure of the machine roll 20. The press roll 35 is brought into contact with the machine roll before the machine roll 20 is detached from the reeling cylinder 15. Above, the invention has been described with reference to some of its preferred exemplifying embodiments alone. This is, however, not supposed to confine the invention to these embodiments alone, but many variations and modifications are possible within the scope of the invention idea defined in the following claims.

Claims: Method in reeling in which a web (W) to be reeled up passes over a reeling cylinder (15) onto a reeling drum, driven by a centre drive (44, 54) and placed on rails (10) and on which a machine roll (20) is being formed, and in which, when the machine roll (20) becomes full, a new reeling drum (22) is brought into a stand-by position to take over the web from the reeling cylinder, characterized in that , before the web (W) is taken over by the new reeling drum (22), a press roll (35) is brought into contact with the machine roll (20) for producing an additional nip, wherein during the transfer of the machine roll (20) to the exchange position the press roll (35) is kept in contact with the machine roll (20) at a point at which the arriving web (W) substantially meets the mantle of the machine roll (20), so that the necessary tension of the web is produced by means of a torque (M) at the centre of the machine roll (20). Method as claimed in claim 1, characterized in that the press roll (35) is brought into contact with the machine roll (20) to produce the additional nip to prevent access of air into the machine roll (20). Method as claimed in claim 1 or 2, characterized in that the press roll (35) is brought into contact with the machine roll (20) before the machine roll is separated from the reeling cylinder (15). Method as claimed in any preceding claim, characterized in that the press roll (35) is brought into contact with the machine roll (20) with a pressure to act upon the structure of the machine roll (20). Reel-up, comprising a reeling cylinder (15) and a reeling drum (22), and in which a web (W) is being reeled, by the intermediate of the reeling cylinder (15), onto the reeling drum through a nip (N) and thus forming a machine roll (20), characterized in that a press roll (35) is arranged to be brought into contact with the machine roll (20) for producing an additional nip before the web (W) is taken over by the new reeling drum (22), wherein during the transfer of the machine roll (20) to the exchange position the press roll (35) is kept in contact with the machine roll (20) at a point at which the arriving web (W) substantially meets the mantle of the machine roll (20), so that the necessary tension of the web is produced by means of a torque (M) at the centre of the machine roll (20).

Inventors: KYYTSOENEN MARKKU, KYYTSOENEN, MARKKU, Kyytsönen, Markku
Applicants: VALMET CORP, VALMET CORPORATION
Application year: 1991
Main classification: B65H19
IPC codes: B65H18, B65H19