EP0778809A1

EP0778809A1 - Method and device for continuously winding up a continuous paper web

Info

Publication number: EP0778809A1
Application number: EP96923944A
Authority: EP
Inventors: Hans-Peter Dr. Sollinger; Rudolf Beisswanger; Ulrich Schettler; Karl-Josef BÖCK; Zygmunt Madrzak; Karl Rück
Original assignee: Voith Sulzer Papiermaschinen GmbH
Current assignee: Voith Patent GmbH
Priority date: 1995-06-28
Filing date: 1996-06-26
Publication date: 1997-06-18
Anticipated expiration: 2016-06-26
Also published as: ATE186277T1; KR970705507A; DE59603559D1; CA2198608A1; WO1997001502A1; US5848756A; EP0778809B1; BR9606556A; JPH10505314A

Abstract

PCT No. PCT/EP96/02797 Sec. 371 Date Jun. 9, 1997 Sec. 102(e) Date Jun. 9, 1997 PCT Filed Jun. 26, 1996 PCT Pub. No. WO97/01502 PCT Pub. Date Jan. 16, 1997A method and device for the winding up of a moving web of paper (9) on a reel spool (11), as large a part as possible of the developing wound roll (12) having a high degree of winding hardness (WH), characterized by the fact that a relatively soft intermediate layer is formed between the wound roll (12) of high winding hardness and the winding core (11). This is achieved in the manner that, during a short initial phase of the winding process, it is ensured that the winding hardness (WH) is relatively slight in the innermost layers of the wound roll (12), whereupon an immediate transition to a relatively high winding hardness (WH) is effected which is being substantially maintained during the rest of the winding-up process. Alternately, the relatively soft intermediate layer can also be created in the manner that the reel spool (11A-11D) has a soft covering (41, 42, 43, 44, 45, 46, 47) on a metal reel spool body (40).

Description

Method and device for continuously winding a running web

description

The invention relates to a method for the continuous winding of a running web in a winding machine, according to the preamble of claim 1. The invention also relates to a device (winding machine) which is suitable for carrying out the method. Such a winding machine can either be a pure winding machine for machine-wide webs or part of a slitter winder.

A winder is e.g. from DE PS 40 07 329 C2 and DE 44 01 959 AI become known. Another constructive solution is a winding machine as described in the European patent application EP 04 83 092 AI. Such winding machines generally form the end section of a paper-making machine or else an off-line coating machine in order to bring the paper web obtained there into the form of a winding roll. In this process, the full width of the paper web is wound onto a spool. This is a roller-shaped winding core, the diameter of which can be over 0.6 m in modern wide paper machines. To support the winding roll that is created on the reel, the reel has bearing pins at both ends, with which it can be attached to e.g. horizontal rails resting.

In other winding machines, which are usually part of a roll cutting machine (see DE 38 32 601 and DE 32 21 929), longitudinally cut partial paper webs are wound onto sleeves. The length of each sleeve corresponds to the width of the paper web in question. The resulting winding rolls are supported by at least one support roller; e.g. is a

ORIGINAL DOCUMENTS provided from two support rollers winding bed provided or there are two winding beds formed from three support rollers. In addition, guide blocks can be present, with a clamping head engaging the respective sleeve on each guide block.

The winding process is of very great importance in paper production because there is sometimes the danger that paper which has been produced perfectly up to now can be impaired during winding in such a way that parts of a winding roll are not for sale. Wrapping defects include the so-called gloss spots, folds and bursts; They are mainly caused by the fact that one wants to form winding rolls with the largest possible diameter and correspondingly high weight.

These winding errors presumably come about as follows: If the paper web is wound on a spool and the winding roll has reached about 60-90% of its finished diameter, the high weight forces cause relative displacements of some paper layers against each other, so that due to the sliding friction between them the paper layers comes to the defects. Such defects occur mainly in the core area of the winding roll, that is to say in the area of up to 25% of the winding support on the reel. If a full winding roll is later unwound and these defects become visible, the remaining paper web is cut off and fed to the reject. For this reason, there is always an undesirable loss through rejects.

There are many theories about how to get a flawless winding roll. One theory says, for example, that the winding hardness should drop from a high initial value to a lower final value (eg DE 40 07 329 C2). The intention with this method is to wind the core area of the winding roll tightly from the start on the drum so that it is stiffened by the paper layers and that this avoids the error points resulting, for example, from the bending of the drum. However, this has the consequence that the web can possibly be overstretched, maybe even burst and thus become unusable. Attempts have also been made to solve the problem by using very rigid reels (with a particularly large diameter), but often without success.

According to JP-A-4-89746, a relatively low winding hardness is initially generated; thereafter it gradually rises to a maximum value, with which the winding is finally completed.

There are two parameters available to influence the winding hardness:

1. The web tension, that is the longitudinal tension with which a paper web runs onto the winding roll.

2. The line force, that is the force that prevails during the winding process in the nip which is located between a roller and the winding roll and through which the paper web runs.

The web tension is generated in a different way depending on the winding machine design. In the case of a winding machine with a carrying drum, a drive for the carrying drum mostly runs slightly faster than the drives of the web guide rollers located in front of the carrying drum. As a result, the web tension is built up, which is then (at least largely) retained due to the static friction on the carrying drum right into the winding roll.

If a web is wound up without the involvement of a carrying drum, the web tension is built up by introducing a torque into the drum ("center drive") by a slightly higher winding peripheral speed compared to the web speed. A combination of the above-mentioned methods or a train structure alone between the carrying drum drive and the center drum drive is also conceivable.

When a line force described above is applied, the winding roll radius at the press point (“nip”) is locally smaller than outside the press point. As a result, the paper web experiences a longitudinal tension when it leaves the press point, which increases the winding hardness. Combinations with the parameters described above are of course also conceivable here.

The invention has for its object to develop a method for the continuous winding of a running web according to the preamble of claim 1, in which the proportion of unsellable paper, cardboard, film or the like resulting from errors in winding is smaller than in known methods .

This object is achieved by the characterizing features of claim 1.

It has been shown that with a further increase in the winding hardness, the problem of the above-mentioned defects cannot be remedied. According to the invention, a completely different approach is taken to solve the problem: a relatively thin, soft intermediate layer is formed - either in the area of the innermost layers of the winding roll being formed or on the casing of the winding core (preferably a reel), and that as large a part of the winding roll as possible with the highest possible winding hardness is formed directly on or at the smallest possible radial distance from the soft intermediate layer. This principle of solution can be implemented in different ways:

A) The formation of a soft intermediate layer "in the area of the innermost layers of the winding roll" means in other words: A deliberate weak point is formed in the core of the winding roll, in which relative movements between adjacent paper layers can take place unhindered

(Claim 2). Surprisingly, the following was found: if only the innermost layers of the winding roll, e.g. The web layers that arise directly on the winding core (drum, winding tube or the like) (comprising a maximum of about 5% of the total layer thickness) are wound relatively softly and then immediately and as quickly as possible further wound with the previously usual high winding hardness, then "core" arises in the core -Gleitstel¬ len ", by means of which further sliding points and thus further defects in the increasingly larger winding roll are avoided. As a result, a significantly larger proportion of salable web material is available than before.

B) An identical or at least similarly good result is obtained if, by using a winding core provided with a soft cover (preferably drum), care is taken to ensure that relative movements between an overall hard winding roll and the hard metallic body of the drum can take place (claim 10). In this case, the "soft intermediate layer" is an integral part of the winding core, preferably the spool.

According to US Pat. No. 5,265,812, attempts have already been made to solve the problem described above by providing the drum with a rubber or a polyurethane cover (with no further details regarding the properties of the cover) or with the tamper has a double jacket, the outer jacket being connected to the inner jacket only at the so-called Bessel points (this construction causes unusually high production costs). The accompanying drawings show various exemplary embodiments of the invention.

1 shows a schematic side view of a carrier drum winding machine (a so-called Pope-Roller).

Figure 2 shows schematically a slitter.

FIG. 3 is a diagram which shows, by way of example, the desired course of the winding hardness WH over the web layer thickness SD wound on a winding core.

FIGS. 4 to 7 show different drum constructions.

FIGS. 8 to 10 show possible modifications of the winding machine shown in FIG. 1.

According to FIG. 1, the incoming paper web 9 first runs through a drawing press 8, then partially wraps around a carrying drum 10 and is then wound onto a drum 11. The resulting winding roll is designated by 12. Longitudinal rails 13 serve to support the reel 11 with the winding roller 12. With the aid of levers 7 and a lifting device 7a, the reel with the winding roller can be pressed onto the carrying drum 10. An adjustable line force is generated between the carrying drum and the winding roll. A control device 6 determines (via a control line 6a) the level of the line force, also via control lines 6b, 6c and 6d, the drives M for the pulling press 8 and / or the carrying drum 10 and / or the drum 11. The control takes place, among other things. depending on the increasing weight or the increasing diameter of the winding roll 12, e.g. by means of a measuring line 6e.

The device described in FIG. 1 makes it possible to vary the line force prevailing between the carrying drum 10 and the winding roller 12, which increases in size, such that it is relatively low in a relatively short initial phase of the winding process and is then increased rapidly. Additionally or alternatively, the so-called web tension can be varied, this is the web tension set in the paper web 9 with the aid of the drives in the web running direction. A specific web tension can be set, for example, by a small speed difference between the carrying drum 10 and the tension press 8 or another web guiding device (not shown) (eg dryer section or smoothing unit). If the drum 11 is provided with a so-called center drive, as shown, a small speed difference can also be set between the winding roller 12 and the carrying drum 10. In all cases there is the possibility of briefly adjusting the web tension to a relatively low value in the initial phase of each new winding process, after which it is increased rapidly. In this initial phase (even during the so-called reel change), the new reel 110 is preferably already on the rails 13. For this purpose, the almost full winding roll 12 is somewhat removed from the carrying drum 10; the levers 7 are immediately applied to the new drum 110 in order to be able to begin with the described control of the line force from the beginning.

With the aid of the previously described variation of the line force and / or the web tension, it can be ensured that the winding hardness WH in each newly created winding roll according to FIG. 3 is relatively low in a short initial phase of the winding process, but then very quickly a relatively high value is increased. Thereafter, the winding hardness WH can be gradually reduced somewhat with increasing web layer thickness SD or kept substantially constant or gradually increased further, depending on the requirements of the individual case or the type of paper.

A similar course of the winding hardness can be achieved when winding up a paper web 9 in a roll cutting machine according to FIG. 2. There the paper web 9 is unwound from an existing winding roll 12a with reel Ila; while she runs via guide rollers 23, 24 and through a slitter 25 to a first support roller 1, which is equipped with a second support roller 2 for the new winding rollers 12 ^! form a changing bed.

Also indicated schematically are a belt guide 26 as a web pull-in aid and a compressed air box 27 with a blower 28 for forming a compressed air cushion between the support rollers 1, 2 and the winding roll 12 '. This compressed air cushion serves to reduce the contact forces of the winding roll on the support rollers when the diameter of the winding roll 12 'exceeds a certain value. In addition, a load roller 37 can be seen, with which the still small winding roller (by means of a pressure device 38) can be pressed against the support rollers 1, 2. A control device 20 receives signals from a setpoint generator 29 regarding the level of the desired working speed and via line 35 a measured value of the instantaneous diameter of the winding roll 12 '. The control device 20 controls the working speeds of the unwinding station (winding roller 12a), the guide rollers 23, 24 and the support rollers 1, 2 via the lines 30 to 34, and also via the line 36 the height of the load roller 37 onto the winding roller 12 'exerted force. To achieve the winding hardness curve according to FIG. 3, at the beginning of each winding process either the braking torque at the unwinding station (winding roller 9a) is briefly reduced and / or the driving torque on the support rollers 1, 2 is briefly reduced relative to the other drives, in order to influence the train. Alternatively or additionally, the pressing force (at 38) can be briefly reduced at the start of the winding process. Likewise, additionally or alternatively, a braking torque or a relief force can be temporarily introduced into the sleeves 11 '. This follows via clamping heads (not shown) which engage in the sleeves and are part of a guide device. The winding roll 12a of the unwinding station, as long as its diameter is very large, is expediently supported by means of a weight relief device 39. As an alternative to the measures described so far, the result of which is shown in FIG. 3, or in addition to these measures, the reels 11 of the winding machine shown in FIG. 1 can be designed according to one of FIGS. 4 to 7. 4, the drum 11A is provided with a relatively thick and soft covering 41, which is firmly connected over its entire length to the metallic body 40 of the drum. Another possibility is shown in FIG. 5. There, instead of a covering, a thin additional outer jacket 42 is provided, which is connected only at its two ends to the jacket surface of the drum 11B, so that an annular space 43 is formed, which can be pressurized with a pressure medium. The pressure can be varied, for example by varying the drive M of a pressure increase pump 44. It is advantageous to increase the pressure as a function of the increasing weight of the winding roll 12 (FIG. 1). 6 shows a detail from a drum IIC. There, a soft rubber layer 45 is applied to a metallic roller body 40 and a hard rubber layer 46 is applied to this. The latter can also be replaced by a thin metal jacket. According to FIG. 7, the soft rubber layer can be replaced by a hose 47 wound spirally onto the roller body 40A, the interior of which is pressurized.

If necessary, you can counteract the increasing weight of the winding roll by means of a flat relief device in each winding process - in addition to the measure specified in claim 1 - at least in the second half of the winding process. Various known devices can be used for this; see e.g. DE 44 22 877.2 or EP 0 384 533 B1. Further possibilities are shown in FIGS. 8 to 10.

The essential parts of the winding device shown in FIG. 8 are:

9 incoming paper web 10 carrying drum 1 11 drum

12 winding roll (the paper web wound on the reel)

13 longitudinal rails for supporting the reel with the winding roller

14 Endless belt for direct support of the winding roll 15, 16, 17 belt guide rollers; One of them (15) is rigidly supported and drivable, the others rest on swivel levers (18); the guide roller (16) is displaceable on the pivoting lever for the purpose of tensioning the belt.

19 lifting device for lifting the pivoting lever and thus for pressing the band 14 onto the winding roller 12 from below.

When it is full, it is removed from the carrying drum 10 on the longitudinal rails 13 (to the right); for this purpose pivot levers 18 and guide roller 16 are pivoted away. If desired, the band 14 comes into contact with the winding roll 12 only when the latter has reached a certain size.

In FIG. 9, the carrying drum 10 takes over the function of the drivable belt guide roller 15 from FIG. 8. An additional tension roller 19 for the belt 14 can be moved approximately vertically.

FIG. 10 is a variant of FIG. 8. The belt guide roller 16 can be pivoted far upwards, so that the belt 14 supports the winding 12 from the beginning, if necessary, and presses the winding onto the carrying drum 10.

These exemplary embodiments have in common that a flat relief force is exerted on the winding roll by means of a single machine-wide endless belt rotating around guide rolls. As a result of this measure, it can be expected that an even higher percentage is available from a winding roll as salable paper than with the measures according to claim 1 alone.

Claims

claims

Method for winding up a running web of paper (9), cardboard, film or the like, on a winding core (11), preferably on a reel, in which method a large part of the winding roll (12) that is produced has a high one Has winding hardness, characterized gekennzeich¬ net that a relatively soft intermediate layer is formed between the winding roll (12) of high winding hardness and the winding core (11).

A method according to claim 1, characterized in that in a short initial phase of the winding process in the innermost layers of the winding roll (12), a relatively low winding hardness is provided, after which a relatively high winding hardness is adopted, which is achieved during the further winding process essentially maintained (Fig. 3).

Method according to Claim 2, for a winding machine, the at least one support roller (or “carrier drum” 10) and a controllable device (7) for pressing a machine-wide winding roll (12) formed on a reel (11) against which has at least one support roller, so that the line force can be varied, characterized in that the lower winding hardness desired in the innermost layers of the winding roll is set by means of only an initially brief, relatively low line force, after which the line force is rapidly increased .

Method according to Claim 2, for a winding machine with at least one center drive M which acts on a drum (11) and which can introduce a controllable torque into the machine-wide winding roll (12), so that the web tension can be varied, characterized in that the lower winding hardness desired in the innermost layers of the winding roll (12) is set by only an initial, brief, low torque, after which the torque (and thereby the web tension) is increased rapidly.

5. The method according to the preamble of claim 3, characterized in that the lower winding hardness is set by an initial brief reduction in the web tension by means of controlling the drive torque of the support roller (10).

6. The method according to claim 2, characterized in that the lower winding hardness is set by applying any combination of the measures of claims 3 and 4, 3 and 5, 4 and 5 or 3, 4 and 5.

7. The method according to claim 2, for a winding machine belonging to a reel-cutting machine, in which the web is unwound in a roll-off station, cut longitudinally into partial webs and the latter - with the support of at least one support roller - is wound onto sleeves, characterized in that sets the desired lower winding hardness in the innermost layers of each winding roll (12 ') by briefly reducing the braking torque at the unwind station and / or the driving torque on the support roller (s) (1, 2) and / or briefly introducing a braking torque directly into the sleeves (11 ') and / or by briefly reducing the contact pressure (38) of a loading roller (37) (which briefly reduces the line force between the winding rollers and the supporting roller (s)) .

8. The method according to claim 7, in which a clamping head is inserted in each end of each sleeve, characterized in that a brief relief force is introduced via the clamping heads into the winding rolls.

9. A device for performing the method according to claim 2, comprising a winding machine and a Steuereinrich¬ device (6) for influencing the winding hardness, characterized by such a design of the control device that it in a short initial phase of the winding process in the innermost layers of the Winding roll triggers the development of a relatively low winding hardness and immediately afterwards the development of a relatively high winding hardness.

10. The device for performing the method according to claim 1, comprising a winding machine with a winding core, preferably a spool, on which the web is wound, and a device for setting a high winding hardness, characterized in that the spool has a soft cover (Fig . 4-7).

11. The device according to claim 10, characterized in that the soft cover (41) is substantially connected to the entire circumferential surface of the reel (11A), and that the cover (41) has a high degree of compliance, corresponding to a rubber hardness of 50 -200 P&J, preferably from 100-150 P&J.

12. The apparatus according to claim 10, characterized in that the cover (42) is connected only in the regions of its two ends with the outer surface of the drum (11B).

13. The apparatus according to claim 12, characterized in that the intermediate space (43) located between the outer surface of the drum (11B) and the cover (42) can be acted upon by a pressure medium.

14. The apparatus according to claim 13, characterized in that the pressure of the pressure medium is variable, e.g. can be increased depending on the increasing weight of the winding roll.

15. Device according to one of claims 12 to 14, characterized in that the cover (42) is formed from a metallic material.

16. The apparatus according to claim 10, characterized in that the soft cover (45) of the drum (IIC) is encased by a hard jacket (46).

17. The apparatus according to claim 16, characterized in that the soft cover (47) of the reel (HD) is formed by a spiral wound and pressurizable hose.

18. Device according to one of claims 9 to 17, characterized in that a device for exerting a flat relief force (z. B. by means of a band 14 or a pressure pad 50) is provided on the winding roll (12).

19. The apparatus according to claim 18, characterized by a control device which triggers the variation of the relief force as a function of the increasing weight of the winding roll.

20. The apparatus according to claim 19, characterized in that the control device controls the amount of the relieving force such that a relative sliding back and forth of adjacent web positions in the winding roll, resulting from vertical shear stresses resulting from the self-weight the winding roll predominantly occur in the area of the horizontal central drum plane and the direction of which reverses with every half drum revolution, at least largely avoided.