FI100003B - Device at an end of the off-machine cardboard treatment line, which lies against the reel - Google Patents

Abstract

When a new roll is changed in an off-machine coating line into the unwinder (1), problems are encountered in matching the tension of the web (16) received from the expiring roll (13) to that to be paid off from the new roll (12). Differences in web tension cause web breaks during roll change. According to the invention, the web is supported at the unwinder (1), and subsequently, at the following dryer cylinder group (2) by means of a support felt (3) serving to the end of equalizing differences in web tension. The web received from the first roll (13) is spliced to the tail of a second, full roll (12) by pressing the web (16) received from the first roll against the web of the second roll via a support felt (3) by means of a splicing roll. Next, the web is fed supported by the felt (3) to a dryer cylinder group (2) comprising VAC and steam cylinders (20, 21) where the damp web is dried for subsequent coating. <IMAGE>

Description

Arrangement at the unwinder end of the off-machine paper handling line.

The present invention relates to an arrangement 5 according to the preamble of claim 1 in an off-machine coating line or other paper finishing line for handling and guiding a web coming from an unwinder to a first coating station.

Paper machine paper is post-processed either by on-machine equipment connected directly to the paper machine, whereby the produced base paper is coated and treated with equipment having a width and speed corresponding to the production speed of the paper machine, or off-machine equipment, where there can be several post-processing systems for one paper machine. The advantages of on-machine systems are high productivity and the fact that the product is completed in one step. In off-machine devices, the properties of the final product can be modified more flexibly and often lead to better quality.

The configuration of the off-machine coating machine can vary greatly and is always designed according to the customer's needs. The line may include, for example, an unroller, coating stations, dryers and a calender. The last line is closed. - 2 0 roller.

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Paper handling with off-machine hardware is performed as follows. The base paper rolls made on the paper machine • · f «. ** · are brought to the finishing line and lifted to the unroller 0ΦΦ to wait for their processing turn. When the previous roll has been processed, it is replaced by m φ 25 full rolls of base paper. The roll change can be done either by stopping the line, # the end of the paper web of the new roll is passed at a slow speed through the line, and the speed Γν- is accelerated to normal. Since the change of the roller in this way is slow, the aim is to change the rollers φφφ -J · · now without stopping the equipment. In this case, when the diameter φ of the roll to be treated becomes sufficiently small, the travel speed is reduced somewhat if necessary, the hand roll is raised from the actual unrolling station to another position and a new roll is fed to the unrolling station. A double-sided tape or other adhesive fastener is attached to the end of the new roll track and its surface speed is accelerated to match the driving speed or 2 reduced driving speeds. The circumference of the new roll is pressed against the web of the previous roll, whereby the tape adheres to the web and the end of the new roll travels along the line with the web of the previous roll. Next, the path of the first treated roller is cut off and the speed of the processing line is accelerated to normal, if necessary.

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From the unwinder, the path passes to the first coating station, from there to the dryers, to the second coating station and further to the dryers and further alternately to the coating stations and dryers, depending on how many coating stations are in line and how many times the coated paper is produced. After coating, the paper can be calendered with either an in-line calender or a separate calender. At the end of the processing line, the paper is rolled back onto the roll with a take-up reel.

One problem with off-machine processing lines such as those described above is the replacement of the roll being processed. Although the roll can be changed, for example, as described above without stopping the line, the web is easily broken when the roll is changed. The main reason for track breaks is the tension difference between the track of the dismantled roller and the track of the new roller. To avoid interruptions, the roller is changed at reduced speeds from time to time. In the event of a track break, the end of the track has to be run through the entire line at a low head speed. Heading causes a production interruption, during which waste paper is generated, especially if heading through the entire line is not possible the first time. If the web is dry or the paper to be coated is thin, the probability of web breaks increases and breaks may occur even during normal driving.

• * φφφ φφ φ m φ φ φ φ .t. The object of the present invention is to provide an arrangement by means of which the roll change mm * φ 25 can be performed with off-machine equipment more reliably than before and at a higher speed r "- \.

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It is a further object of the invention to provide an arrangement by means of which paper with a higher initial moisture content can be treated in the off-machine unwinding of the apparatus.

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The invention is based on the fact that the web coming from the first, emptying roll is supported by a support felt and the web of the first roll is connected to the end of the second full roll web by pressing the web of the first roll supported by the felt with a connecting roller against the second roll.

More specifically, the arrangement according to the invention is characterized by what is set forth in the characterizing part of claim 1.

The invention provides considerable advantages.

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The most important advantage of the invention is the reduction of track breaks during roll change. The downtime of the paving line is clearly reduced as the line breaks are reduced. The roll can be changed at a higher speed than before and at the speeds currently in use, even at the highest speed of the processing line, so that the equipment always operates at the highest possible efficiency. Because the initial moisture content of the paper can be increased, the probability of track breaks is further reduced because wetter paper is less susceptible to breakage due to interference than dry paper. The proportion of sulphate pulp in the base paper can be reduced, which reduces its price and improves the opacity. The basis weight of the base paper can be reduced, i.e. a thinner '2 0 base paper can be used, so that more • * * φ * · coating can be used for the same basis weight of the finished paper. With a larger amount of coating, better weight properties are achieved.

Keks sel sel + φφφ φ φ φ «· φ φ φ φ ..T * The invention will be explained in more detail below with the aid of the accompanying drawings.

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Fig. 1 is an overview of an off-machine coating line in connection with which an arrangement according to the invention is traced in connection with an open winder * · sTs.

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Figure 2 is a detail of Figure 1.

Figure 3 is a detail of Figures 1 and 2.

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Figure 1 shows a coating line with two on-call stations 4, 7. The first line has an unroller 1. The paper web to be treated from the unroller 1 is guided by a felt 3 to a first dry cylinder group 2. The dry cylinder 2 dries the wet web to a suitable moisture for coating. After drying, the web 5 is led to the first coating station 4. After coating, the wetted web and the coating are dried with dryers 5. The assembly of Figure 1 has first three dryers and then a second group of dry cylinders 6 consisting of three steam cylinders and three vacuum or VAC cylinders. supported by a felt. After the second dryer cylinder group 6 there is a second coating station 7, two dryers 8 and a third dryer cylinder group 9 consisting of VAC and steam cylinders 9. After this cylinder group 9 the web is rewound on a roll by a winder 10. In case of line breaks the system may include three pulpers 11 at the end of the dryer cylinder groups 2, 6, 9. In the event of a track break or other disturbance, the track is cut after 15 groups of dryer cylinders with an edge band cutter and directed to pass to the pulper 11. The edge band remaining at the edge of the track is conveyed through a rope nipple formed by guide ropes. When the fault has been rectified, the blade of the edge band cutter is moved transversely to the direction of travel of the track, whereby the track spreads to its normal width.

• 20. The above is only an example of a modern paper finishing line,. ··· ;. which includes an arrangement according to the invention. It is clear that the number and type of coating stations, • 5 ·· · · · dryers and other line equipment are selected according to the requirements of the paper mill · »* · ·· ·· and the quality of the paper to be produced.

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Figure 2 shows in more detail the unwinding roller 1 and the associated dryer unit 2. The unwinding roller 1 consists of a body part 14, on the upper surface of which there are roll feed rails, at the end of which the actual unwinding station, i.e. the primary station. The first full roll marked with the reference number «I« «* t« · * · 12 is in the primary position. Adjacent to the body 14 are 30 transfer roller transfer arms 15, to the locking jaws 27 of which are attached an end roller 13. At the opposite end of the arms 15 they are attached to the transfer arm body by a joint 26. On the right side of the open roller 1 there is a dry cylinder group 2 consisting of three vacuum -, i.e. from the VAC cylinder 20 and the three steam cylinders 21. The paper web passes through the dryer cylinder group under the control of the support felt 3.

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The support felt 3 runs in the apparatus as follows. A first folding roll 17 and a connecting roll 18 are arranged in connection with the secondary station of the unfolding roller 1. The felt 3 first enters the folding roll 17, where it is turned to run downwards parallel to the paper path 16 coming from the roll 13. Beneath the unwinder 1 there is a second folding roll 19 by which the felt 10 is turned to pass to the dryer cylinder group 2. In this cylinder group 2 there is first a VAC roll 20. The VAC roll is a roll with a vacuum inside and because the roll surface is porous or has small holes, the vacuum sucks the roll 3 circulating the roll 20 and the paper web 16 on the felt onto the roll. The purpose of the VAC cylinder is to ensure that the web remains attached to the felt 3 and, in addition, the vacuum 15 ensures that the felt 3 runs smoothly when rotated by the cylinder group 2 and does not slide too much on the rollers.

From the VAC cylinder 20, the felt 3 and the web pass to the steam cylinder 21. In the steam cylinder 21, the paper web 16 is pressed against the surface of the cylinder 21 by the felt 3. The steam-heated hot cylinder 21 now efficiently transfers heat to the web and dries it under the influence of the heat. Next, the felt and paper pass to the next

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For VAC cylinder, steam cylinder and one more VAC cylinder and steam cylinder «· * · ·» »·. The free sector part of the steam cylinders 21, which in this case is below the cylindrical blades, has cleaning scrapers 22, the function of which is to remove any coating which may adhere to the surface of the steam cylinders 21.

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The paper web 16 is separated from the felt 3 after the last steam cylinder. The felt 3 is guided above the roller group via folding rollers to a tension roller 25 from which the felt passes. to the first folding roll 17 and the web of the felt closes into an endless loop.

30 The paper web, in turn, is pulled from the steam cylinder 21 via the draw nip 24 to the first coating station 4. The draw nip 24 is necessary in this case to make the paper web 6 separate from the felt and because the distance between the first coating station 4 and the dry cylinder group 2 is large. In addition, the traction nip 24 equalizes the track tension. Between the last steam cylinder 21 and the traction roller nip 24 there is an edge band cutter 23 with which, in the event of a track break, the track is cut to pass to the pulp-5 11.

Figure 3 shows in more detail the unroller 1 and its parts related to the roll change. It should be noted that not all the details of Figure 3 are shown in Figures 1 and 2 for reasons of scale. At the other end of the transfer arms 15 there are fastening jaws 10 27 to which the final roll 13 is fastened during the change of roll. As already mentioned, the support felt 3 enters the unwinding roller 1 and is turned to run parallel to the path 16 coming from the end roll 13 by a folding roller 17. In the direction of travel of the felt web 3, a connecting roller 18 is next arranged. The connecting roller 18 is mounted on an articulated arm 30 and the roller 18 is moved by an air bellar 31 with a connecting arm 15 to the arm 30. In Fig. 3, the connecting roller 18 is in the position where the track of the new roller 12 is attached to the trailing roller track 16. In addition to these members, the opening roller 1 also has a cutting blade 29. The cutting blade 29 is arranged above the support felt 3 on the folding roller 17, that the break point of the track 16 enters the secondary position for the part between the lifting roller 13 and the first folding roll 17. Along the cutting blade 29, a support roller 28 is arranged, which tightens the track 16 coming from the secondary station so that it can be easily cut by hitting with a curved cutting blade 29.

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Paper rolls and webs are processed with equipment such as that described above as follows: ♦ · «« ♦ · * ·. • .n :. way.

······ • · 25 ;; · * · ♦. In Fig. 2, the resting roller 13 is raised on the transfer arms 15 to the secondary station and the next roller 12 has entered the primary station. In this figure, the roller 12 of the primary station still rotates freely. Double-sided tapes are attached to the surface of the roller 12 of the primary station and its speed is accelerated to correspond to the speed of the track coming from the roller 13 in the secondary station 16:30. The track 16 coming from the secondary station hits the support felt 3 with the first folding roller 17 and then passes supported by the felt 3. When the diameter of the roller 13 in the secondary station 7 is disassembled sufficiently small and the roller in the primary station is accelerated to a sufficiently high speed, the track 16 of the secondary station roller 13 is attached to the surface layer of the primary station roller 12 by double-sided tape. The attachment takes place in such a way that the position of the end of the tape is indicated, for example, by a photocell which instructs the actuator 31 of the connecting roller 18 to press the path 16 from the secondary station onto the surface of the roller 12 rotating at the primary station. Shortly after clamping, the curved cutting blade 29 strikes the track 16 from the secondary station by rapidly turning behind the support roller 28 to strike the track 16. The paper path then comes from the roller 12 from the primary station.

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Line breaks in the phase described above have been the most common of the line breaks on paving lines. The main reason for the track breaks has been the large tension difference between the track 16 from the secondary station and the roller 12 at the primary station, which has caused a tearing jerk on the new track as the track tightens after the joint. Now, however, in the solution according to the invention the path travels supported by the felt 3, whereby the path cannot be tightened too fast, because it has to travel with the felt 3 and the speed of the felt 3 does not change during and after the connection. In the most preferred embodiment of the invention, described above, the traction of the track is ensured by VAC cylinders 20 which suck the track into the support felt 3. The support felt 3 can reduce the probability of track breaks so much that the roll can be changed at full speed if desired.

* t · * · • M · • · · · • * · ♦ • M i; *. · '··. When the roller 12 in the primary station is disassembled, its diameter decreases and the support felt * · · • «* ·: \ rv; the folding 17 and the connecting rollers 18 must be moved in the direction of the roller 12 so that the path coming from the roller 12 4 «25 does not become detached from the support felt 3. To make this transfer possible, a tension roller 25 is traced on the felt 3 • V **. loosen. By means of the movement of the tensioning roller 25, the subject of the fastening movement of the connecting roller 18 is also received. * *; , uttama felt 3 track change.

3 0 When the diameter of the roller 12 in the primary station decreases to a certain setpoint, it 4! t "| is raised by the transfer arms 15 to the secondary position and the first folding roll 17 and the connecting roll 18 δ are moved backwards so far that the next roll fits into the primary position. The actual roll change takes place again as described above.

One feature substantially related to the invention is a traction roll nip 24. This nip consists of two rollers, one of which is a traction roll and the other a support roll, and a release scraper. In the embodiment shown in the figures, the draw roll nip 24 is located after the drying cylinder group 2 and its position in the direction of travel is always chosen so that it is separated from the support felt 3 and before the first coating station 4. Between the draw roll nip 24 and felt 3 and the paper web separation point. there is an additional 10 edge band cutter 23. The traction nipple 24 and the edge band cutter 23 have several functions in the arrangement. Since the web comes from the unroller 1 supported by the support felt 3, it does not tighten to the normal web tension in the same way as an unsupported web pulled directly from the roll by traction rollers. For this reason, the tension of the track is equalized by means of a traction roller nip in order to make the track travel at the correct tension to the next processing steps. The traction roller nip 24 also ensures that the track is clearly different from the support felt 3. The edge band cutter 23 has the function of cutting the track if there is a disturbance in the coating line. The web is cut with a blade running transverse to its direction of travel so that the blade runs close to the edge of the web and stops before it cuts. . completely across the track. In this position, the blade cuts a narrow edge band from the track, "V. 20 which is guided in a line by means of a string nipple. The main part of the track now passes through the pulp; ' and the rotation of the truncated track around the traction roller is prevented by a separation scraper.

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Once the cause of the fault has been eliminated, the blade of the edge band cutter 23 is moved to the other edge of the track: *. 1 ·%. ·, Whereby the track spreads to its full width from the string nipple. In this way * * *** ... '.'Vs. ·. fast head removal after breaks, and shorter downtime due to track breaks and other disturbances.

• · · • · ♦ ♦ • · ·

In addition to the above, the present invention has other embodiments.

In its simplest form, the invention comprises only a support felt 3, 30, a first folding roll 17, a connecting roll 18, means 25 for tightening the felt, and folding rollers for controlling the passage of the felt 3. In principle, the first folding roller is not • 1. · · • · · · 1 ♦ 9 required, but the blanket can be guided directly to the connecting roller 18. In this case, the track should be guided directly without a traction nipple to the first coating station or other processing equipment. This arrangement could be suitable for feeding the web directly from the unwinder to some type of calender, whereby the calender would form a drawing nip 5 separating the paper web from the felt 3. In practice, the apparatus usually includes a drawing roll nip 24 and at least one pair of cylinders. These cylinders are most preferably VAC cylinders and dryer cylinders, whereby the web can be dried before its actual treatment with a coating station or other device. The number and type of cylinders can be selected according to the required drying power and the desired mechanical solution. It is clear that the control, tightening and mechanical structure of the felt can be implemented in many different ways.

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Claims (6)

An arrangement in a paper finishing line, the line comprising at least a 5-continuous unroller (1) comprising at least a primary station where the paper is unloaded from the roll (12) and a secondary station to which the unloaded roll can be moved after reducing its diameter, the new roll being introduced into the primary station, the paper therein connects to the paper web (16) coming from the secondary station and the paper web (16) coming from the secondary station is cut off, - one finishing device (4), and - a support roll (10) 15 - a support felt (3) supporting the open web (16),. . - of the rollers (17 to 21, 25) through which the support felt (3) is arranged as an endless loop of the * * V 20 ground so that • «·. * ·.% - one of the rollers is a movable roll (18) which is arranged in connection with the track (16) coming from the secondary station of the carriage (1) «· · so that this track (16) runs on the support felt at the roll (18) ·· · · · · ·: 25 and which roll (18) is movable towards the roller (12) at the primary station • to press the track (16) from the secondary station: against the surface of the roller (12) at the primary station via a felt (3), and: - at least one of the rollers is movable by a tensioning roller, which 3. allows the tension of the felt to be adjusted. Arrangement according to Claim 1, characterized in that at least one of the rollers is arranged as a folding roll (17) in connection with the track (16) coming from the secondary station so that the point of contact between the felt (3) passing through the roll (17) and the felt . 5 Arrangement according to Claim 1 or 2, characterized in that at least one of the rollers is a vacuum cylinder (20). An arrangement according to claim 2, characterized in that at least one of the rollers 10 is a heated dryer cylinder (21). Arrangement according to one of the preceding claims, characterized by a traction roller nip (24) arranged in connection with an endless loop formed by the support felt (3) and through which the paper web 15 from the unroller (1) supported by the felt (3) can be adapted to separate the web from the felt (3) . An arrangement according to claim 5, characterized by an edge band cutter (23) arranged between the support felt (3) and the separation point of the paper web and the drawing roll nip (24). 20 • · • · • «« 1 1 · · · • · · • «·« • 1 · • · · «• ·« ·