Patent Application
20240400329
The invention relates generally to unwinding of fiber webs and to unwinding sections for unwinding fiber webs from parent rolls. Especially the invention relates to an unwinding section and the joining ends of fiber webs in an unwinding section.
It is known that fiber webs, e.g. paper and board webs, are manufactured in machines which together constitute a fiber web production line which can be hundreds of meters long. As known from the prior art in fiber web producing lines typically comprise an assembly formed by a number of apparatuses arranged consecutively in the process line. A typical production and treatment line for fiber web comprises a head box, a wire section and a press section as well as a subsequent drying section and a reel-up. The production and treatment line can further comprise other sections and devices for treatment and/or finishing the fiber web, for example a sizer, a coating device, a calender. The production and treatment line also typically comprises at least one slitter-winder for forming customer rolls as well as a roll packaging apparatus.
In fiber web production lines, the manufacture of the fiber web takes place as a continuous process. A fiber web completing in the fiber web machine is reeled by a reel-up around a reeling shaft i.e. a reel spool into a parent roll the diameter of which can be more than 5 meters and the weight more than 160 tons. The purpose of reeling is to modify the fiber web manufactured as planar to a more easily processable form. On the reel-up located in the main machine line, the continuous process of the fiber web machine breaks for the first time and shifts into periodic operation. Reel-ups are used in fiber web production for reeling the fiber web coming from the fiber web production line, and also from a coating machine, a calender or a corresponding finishing device.
The fiber web wound onto the parent roll is full-width so it must be slit in longitudinal direction into partial fiber webs with suitable width and the partial fiber webs are wound to partial fiber web rolls (customer rolls) of suitable length or of suitable diameter for the customers. The slitting and winding take place as known from prior art in an appropriate separate machine i.e. in a slitter-winder. Slitter-winders employ winding devices of different types, for example multistation winders and two-drum winders. In the two-drum winders the partial webs are wound around winding cores supported by two winding drums to partial web rolls via a nip between the winding drums and the partial pulp web rolls being formed. In the two-drum winders also a belt arrangement i.e. a so-called set of belt rolls with belt loop or belt loops located around two guide rolls can be used as the winding drum. As known in the prior art, also winding with a shaft without cores or together with cores can be employed in the winding of a pulp web into customer rolls on a slitter-winder.
As known from the prior art, in the slitter-winder the parent roll is unwound in an unwinding section, the full-width fiber web is slit on the slitting section into several narrower partial fiber webs which are wound up on the winding section around winding cores or around winding shafts or around winding cores located on the shafts, such as spools, into customer rolls. When the customer rolls are completed, the slitter-winder is stopped and the rolls i.e. the so-called set is removed from the machine after which the process is continued with the winding of a next set. These stages are repeated periodically until paper runs out of the parent roll in the unwinding section, whereby a parent roll change is performed and the operation starts again as the unwinding of a next parent roll. In cases the unwinding section comprises only one unwinder the stages are repeated until the fiber web on the parent roll runs out from the reeling shaft, at which point the parent roll is replaced, the end of the fiber web from the running-out parent roll is joined to the beginning end of the fiber web from a next, new parent roll and the operation restarts with the unwinding of a next parent roll from the reeling shaft. The unwinding section may also comprise two unwinders. For example in patent publication FI 121007 B is disclosed an unwinding section comprising two unwinding positions, in which the unwinding of a full parent roll is first begun in a first unwinding position of the unwinding section and then transferring the partially unwound parent roll to a second unwinding position during unwinding in the unwinding section and the unwinding is finished in the second unwinding position. In the slitter winders comprising two unwinders the slitting and winding stages are repeated until the fiber web on the parent roll runs out from the reeling shaft in the first unwinder, at which point the run of the fiber web is changed to be from the parent roll in the second unwinder by joining the end of the fiber web from the running-out parent roll in the first unwinder to the beginning end of the fiber web from a next parent roll in the second unwinder and the operation restarts with the unwinding of the next parent roll from the reeling shaft in the second unwinder. When the parent roll in the second unwinder is running out the unwinding is again changed to be from the first unwinder and the end of the fiber web from the running-out parent roll in the second unwinder to the beginning end of the fiber web from a next parent roll in the first unwinder and the operation restarts with the unwinding of the next parent roll from the reeling shaft in the first unwinder.
In the joining of the end of the parent roll to the beginning end of the next parent roll it has been difficult to find a functional joining method. For example using of adhesive tapes has proven disadvantageous, as the tapes may peel of fibers from the surface of the fiber webs. At the present most promising joining method has turned out to be a form fitting joint, in which the ends of the fiber webs are joined to providing to the overlapping ends of the fiber webs form fitting attachment by a joining device, typically comprising a tool element and its counter element, between of which the overlapping ends are located for creating the joint. In connection with joining devices for joining the ends of the fiber webs for the parent roll change in the unwinder for a slitter-winder the preparation of the end of the new fiber web and removal of the broke fiber web is performed before joining the ends of the fiber webs. Typically, this has been done manually by the operators, which increases the work safety risks. It is also known to use a separate suction roll for collecting the broke fiber web for removal as a separate operation after the joining of the fiber webs.
In FI patent publication 129673 is disclosed a method and a device for joining ends of fiber webs in a parent roll change of an unwinder. The method is configured to be performed by a device comprising a tool element, a gripping device and a traversing punching device, whereby at a stage, in which a parent roll in the unwinder is almost empty, the run of the fiber web from the running-out parent roll is moved to a joining position at the tool element and the trailing end of the fiber web from the running-out parent roll is cut upstream from the joining position and the fiber web is attached to the tool element by means of gripping effect created by the gripping device, at a next stage a beginning end of a new fiber web from a new parent roll is guided to contact with and to an overlapping position with the trailing end of the fiber web from the running-out parent roll and the rotating movement of the new parent roll in the unwinder is stopped, at a next stage the traversing punching device is moved across the width direction of the fiber webs and is configured to make at least one joint cut to the overlapping ends of the fiber webs and to join the ends of the fiber webs to each other, the beginning end of the new fiber web from the new parent roll in the unwinder is cut downstream from the joint for removing the beginning end simultaneously or after making the at least one joint cut, and at a next control of tension of the joined fiber webs is turned on and the joint joining the ends of the fiber webs is ready. In this patent publication 129673 disclosed method at the stage in which the new parent roll has been transferred to the unwinder, the new parent roll in the unwinder is rotated and the end of the new fiber web is guided to a pulper, in which the end of the fiber web is tensioned and straightened by an element of the pulper for the joining of the ends of the fiber webs and the rotating movement of the new parent roll in the unwinder is stopped. These elements arranged in the pulper for tensioning and straightening the end of the fiber web are typically water showers and like and in some cases these types of elements of the pulper have proven not effective enough for secure operation, especially in cases where the pulper opening is remotely located in respect of the joining location.
In known systems it has been difficult to find a well functional way to handle broke fiber web generated in connection of joining the ends of the running-out parent roll and the new parent roll. In particular relating to handling of the end of the fiber web from the running-out parent roll and the end of the fiber web from the next parent roll to be unwound after joining of the fiber webs such, that the broke guided to desired broke handling and the new fiber web is tight and straight enough for the joining.
Another object of the invention is to create an unwinding section for fiber webs and a method of joining ends of fiber webs in an unwinding section, in which the problems of from prior art known arrangements and methos are eliminated or at least minimized.
Another object of the invention is to create an unwinding section for fiber webs and a method of joining ends of fiber webs in an unwinding section, in which the problems relating to removal of the beginning end of the fiber web joined are eliminated or at least minimized.
A further object of the invention is to create an unwinding section for fiber webs and a method of joining ends of fiber webs in an unwinding section, in which savings are achieved in operator work.
An object of the invention is to create an unwinding section for fiber webs and a method of joining ends of fiber webs in an unwinding section, in which the disadvantages of known systems and methods relating to safety risks relating to manual operations are eliminated or at least minimized.
According to the invention the unwinding section for unwinding a fiber web from a parent roll comprises at least one unwinder for unwinding a fiber web from a parent roll and a joining device configured to join a trailing end of a running-out parent roll to a beginning end of a next, new parent roll to be unwound in a parent roll change, and which unwinding section comprises or is located in vicinity of a broke handling device configured to handle broke, wherein the unwinding section comprises a tensioning device located between the joining and the broke handling and the tensioning device is configured to tension and straighten the fiber web to be joined between the tensioning device and the joining device before joining of the end of the fiber web from the running-out parent roll and the end of the fiber web from the next parent roll to be unwound. Advantageously the tensioning device is located between the joining device and the broke handling device.
According to an advantageous feature of the invention the unwinding section is located on located on a maintenance level comprising an opening for removal of broke fiber web to the broke handling device and the tensioning device is located above the opening and downstream in running direction of the fiber web running from the next parent roll to be unwound from the joining device.
According to the invention the tensioning device is configured to guide the cut beginning end of the fiber web from the next parent roll to be unwound after the joining of the ends of the fiber webs in the parent roll change to the broke handling device.
According to an advantageous feature of the invention the tensioning device is configured to guide the beginning end of the fiber web from the next parent roll to be unwound towards the opening and the broke handling device.
According to an advantageous feature of the invention the unwinding section comprises a counter roll for the tensioning device, and the counter roll is configured to provide a tensioning effect with the tensioning device and the fiber web from the next parent roll to be unwound is configured to be guided between the counter roll and the tensioning device.
According to an advantageous feature of the invention the tensioning device is movable between a resting position and a tensioning position.
According to an advantageous feature of the invention the tensioning device comprises a continuous belt loop running and supported by two or more rolls located inside the belt loop.
According to an advantageous feature of the invention the unwinding section comprises two unwinders and that the joining device comprises a movable tool element and a stationary counter element. Alternatively, according to an advantageous feature of the invention the unwinding section comprises only one unwinder and the joining device comprises a stationary tool element and a movable counter element.
According to an advantageous feature of the invention the unwinding section is an unwinding section of a slitter-winder.
According to the invention in the method for joining ends of fiber webs in a parent roll change of an unwinding section located in vicinity of or comprising a broke handling device configured to handle broke, the ends of the fiber webs are configured to be joined by a joining device, wherein the fiber web running from a next parent roll to be unwound is tensioned and straightened by a tensioning device before joining of the end of the fiber web from the running-out parent roll and the end of the fiber web from the next parent roll to be unwound, by the tensioning device located between the joining and the broke handling the cut beginning end of the fiber web from the next parent roll to be unwound after the joining of the ends of the fiber webs in the parent roll change is guided to the broke handling device.
According to an advantageous feature of the invention in the method the fiber web running from the next parent roll to be unwound is tensioned and straightened by the tensioning device above a maintenance level.
According to an advantageous feature of the invention in the method the fiber web running from a next parent roll to be unwound is further tensioned and straightened by a tensioning device simultaneously and after joining of the end of the fiber web from the running-out parent roll and the end of the fiber web from the next parent roll to be unwound.
According to an advantageous feature of the invention in method the ends of the fiber webs are configured to be joined by a joining device comprising a tool element and a counter element and the trailing end of the fiber web from the running-out parent roll and the beginning end of a new fiber web from the next parent roll are guided to an overlapping position between the tool element and the counter element for joining and the beginning end of the fiber web running from the next parent roll to be unwound is tensioned between the joining device and the tensioning device.
According to an advantageous feature of the invention in the method the unwinding section is run at a crawling speed during the joining of the ends of the fiber webs.
According to an advantageous aspect of the invention the unwinding section comprises the tensioning device and the end of the fiber web from the next, new parent roll is guided to the broke handling device, for example to the pulper, such, that the fiber web to be joined coming from the new parent roll is located between the tensioning device and the joining device. The fiber web to be joined is tensioned and straightened between the tensioning device and the joining device before joining of the end of the fiber web from the running-out parent roll and the end from the next parent roll to be unwound. After the joining and the cutting of the fiber web, the cut end of the fiber web, i.e. the broke end of the fiber web continues its travel to the broke handling device assisted by the tensioning device.
The invention is utilizable in unwinding sections comprising one or two unwinders, in particular in unwinding sections of slitter-winders, in which the ends of the fiber webs in the parent roll change are joined by a joining device advantageously comprising a tool element and a counter element for creating a form fitting joint.
By the invention and its advantageous features several advantages are achieved: The end of the fiber web to be joined is securely tensioned and straightened before the joining and the broke fiber web is handled in connection with the joining operation. Thus, no broke fiber web remains to be handled after the joining. Also, the end cutting does not need special accuracy as the cut end is guided to the broke handling and the finalizing end cutting is performed in connection with the joining One of the main advantages is also, that no manual removal of the broke end is needed. Additionally, savings are achieved in operator work. The safety and ergonomics of the operator are also provided due to decreased need of manual work operations. The invention provides an improved and well-functioning way of handling broke fiber web generated in connection of joining the fiber web ends. Also, effectivity is increased as the fiber web is tightened and straightened before the joining in the location before broke handling. Further, manual operations are improved, as the tensioning device is located in a well reachable location.
Aspects of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of some example embodiments when read in connection with the accompanying drawings and in the following the invention is described in more detail referring to the accompanying drawing, in which
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In the method the unwinding section 10 is run at a crawling speed during the joining of the ends of the fiber webs W1, W2 i.e. during the stages described above in connection with
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In the description in the foregoing, although some functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments or examples, those features may also be present in other embodiments or examples whether described or not. Above the invention has been described by referring to some advantageous examples only to which the invention is not to be narrowly limited. Many modifications and alterations are possible within the invention as defined in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20235600 | May 2023 | FI | national |
