FI122110B - Procedure in a paper or cardboard machine line - Google Patents

Description

Method in a paper or board machine line

The invention relates to a method according to the preamble of claim 1.

5

It is known in the art to provide jet lags in which means, such as belts, suction and / or blows, are provided at the periphery of the web in order to hold the web to an edge so as to eliminate the transverse shrinkage effect of web drying. Such debriefings are disclosed in SE Patent Specifications 440518, 10462171, 468217, 517689 and International Application Publication WO 90/14467.

These known arrangements are quite complex and one problem with them is that the force effect extends across the web across the web, whereby it is not possible to control the cross-shrink profile of the web in a targeted manner. The prior art arrangements thus have the effect of reducing the entire 15 shrinkage levels while aiming to straighten the profiles.

On the other hand, in the prior art reference may be made to the measurement and adjustment of the cross section, and to the measurement and adjustment solutions of the shrink profile and the strain profile or web, e.g. FI 990271, FI 20 992849, US 6200422, FI 20020068, US 5943906 and US 6343240. The problem with these known solutions is that these known methods cannot adequately modify the deformation (shrinkage / stretch profile) of the paper. ° On the other hand, variation in the shrinkage profile also degrades the result of multiple adjustments, so for this reason it should be possible to keep both the elongation profile and the shrinkage profile as constant as possible so that the process models used and the actual c measurement result. This gives the adjustment the best performance.

WO 97/49863 discloses a method and apparatus for drying and cooling the web by passing the web over the curved circumference of the blowing device,

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2 from which the blower is squeezed to the edge of the web and supporting support wire, and where the web is flush with the edges of the web and supporting support wire at each end thereof In the apparatus known from WO, the web is fixed at the edges by means of special suction edge wheels and the middle region of the web is dried by means of fixed foil nozzles below. Such an apparatus, located at the top of the drying section, allows wet spreading of the web 10 by means of suction wheels at the end of the space. The wheels suck the track and the outward tread of the wheels allows the track to be spread. The problem with this known solution is that the contactless support zone does not allow application of the application. Also, this disclosure does not disclose an arrangement for controlling or controlling the effect of the web support. It is an object of the invention to provide an improvement on this arrangement and to further develop it, thereby eliminating the above disadvantages.

Throughout the history of paper and board production, problems have been encountered in web edges where transverse shrinkage and stiffness properties have been worse than in the central web. The problem is particularly pronounced with single-wire driers and will be a significant factor in the manufacture of i-driers for high-speed machines where the uniformity of the aforementioned quality characteristics has a significant advantage.

25 o 25 One of the problem areas in paper making is therefore edge management.

c As single-wire dryer sections become more common, transverse to central

(Lf) the shrinkage and material properties have been made quite uniform, which results in the web having a very uniform quality except at the periphery. In certain cases, strong changes in quality and drying-shrinkage focus on the peripheral area

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3 may be so large that the paper properties become so weak that the edges of the web do not become a marketable product, which may result in rejection of customer rolls cut from the edges in the longitudinal section.

One problem with prior art arrangements when using CD control in shrinkage control is that variation in shrinkage will confuse the control operation. In this regard, reference may be made, for example, to John Shakespeare's Identification and Control of Cross-machine Profiles in Paper Machines: A Functional Penalty Approach, University of Technology Publications 352, 2001 (ISBN 952-15-10 0719-5, ISSN 0356-4940). .

As is known in the art, especially in single-wire dryer paper machine dryer sections, the web exhibits a centrally uniform shrinkage profile in the transverse direction which grows strongly in the peripheral regions. The sharp shrinkage profile 15 at the edges causes that, for example in the case of paperboard, the edges cannot be used in further processing, but the edges are usually cut off. This causes loss of production and reduces machine efficiency.

One problem in the prior art solutions is to relate the fiber orientation of the web 20 to the runnability. The runnability most advantageous is a web in which the fiber orientation is machine direction, wherein the fiber orientation distribution ellipse is very oval in the machine direction. On the other hand, further transverse fiber orientation is required to ensure dimensional stability cu, whereby the distributional ellipse becomes rounder. Different paper types require a different 0 25 distribution ellipse: for example, sack paper requires good strength in all directions, 1 fine paper requires good dimensional stability, and newsprint requires good fiber orientation, requiring a different fiber orientation. In the machine direction, the ellipse oo o fiber orientation distribution ellipse implies greater transverse shrinkage, o o cu 4 because there are fewer fibers in the transverse direction of the web that would prevent shrinkage in that direction.

Prior art problems associated with profile control combined with drying shrinkage of edges 5 will be accentuated by increasing machine speeds and higher machine direction pulls used, since the web edges have a weaker ability to withstand the increasing force forces, thus stretching and consequently tensioning the web adversely affect paper quality properties. As the speeds have increased, the first 10 drying groups have to be shortened in order to obtain machine-drawn tension in the rather wet web at the beginning of the drying by always running the latter drying groups faster than the previous one.

It is an object of the invention to control the transverse properties and the quality profiles of the paper or board web and to control the transverse force effect relative to the web direction of the web caused to repair them taking into account the overall situation.

It is an object of the invention to provide a method for controlling and controlling the transverse quality profiles of a paper combined with controlling the shrinkage of the edges.

cm In order to achieve the above and later objects, the method according to the invention is essentially characterized by what is disclosed in the characterizing part of claim 1.

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In the method according to the invention, the transverse dimensions of the paper are changed / adjusted in a controlled manner as desired. The basic principle of the invention is that the transverse dimension of the track after application is greater than before the application

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Thus, at the just before the holding area of the force applying device, preferably the roll and the device, one half separated by the center line of the web is smaller than either side after the roll and the center line continues in parallel through the application process of the force device.

5

The method of the invention is also preferably connected to wet end actuators and, according to a preferred embodiment, as the web moves from the wet end to the dry end, both the dry end and wet end devices are used in the web management method. At the wet end, actuators for cross-section control 10, for example, the system used to control the dilution water of the dilution headbox, may be used in connection with the method of the invention. A change in the wet end actuator causes a change in the process, the effect of which is observed as a change in the web. The effect of the change of the actuator on the profile measured from the web is important for process control, since the control, in particular the adjustment or optimization of the cross section, uses response patterns that illustrate this effect. For example, the dilution valves in the dilution headbox control the basis weight cross-section in a manner known per se. In particular, it is to be noted in connection with the invention that an actuator is capable of generating an excitation signal for controlling the expansion and contraction of the web. The use of such an excitation signal 20 is known per se, as well as detecting the change caused by it and determining the shrinkage profile and targeting the actuators to the measurement profile. i- In this way, the known width section can be removed from the web, since the quality characteristics of the cm edge of the web are not sufficient for further processing.

In the method of the invention, wet end c measurement can also be used to measure the profile before the application roll. In this case, a second measurement is performed after the LO roller to determine the changed profile, oo oo o o o o

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In the application device of the invention, the web is held in the manner described in the invention, at least in the middle by the holding device, but also, if desired, by the whole time or in a manner determined by the control. In connection with the holding device, there is a device for spreading the left edge of the web, which holds the left edge of the web in accordance with the invention to effect application. The length of application is determined either manually or based on the optimization instruction provided by the control system of the invention. Similarly, the application angle (pitch) to be used is already predetermined or controlled manually or by the optimizer. A device for spreading the right edge of the web is also attached to the holding device, which functions similarly to the device applying to the left.

Typically, the web shrinks before the dry end measuring apparatus is located on the dry end, whereby the application of the invention is aimed at eliminating the effect of shrinkage, that is, in order to obtain a shrinkage profile in a straight or at least well-established form. The dry end measuring apparatus measures the properties of the paper, such as basis weight, moisture, etc. The measurement of the web can also be performed immediately after the application device, whereby application can also be controlled based on this measurement. The setpoint for spreading may then come from the dry end control unit, either set by the operator or determined by an automatic control operation such as feedback control or optimization.

It is also possible to use both measurements at the same time and to weight the measurements in a manner known per se, for example, by immediately following the · · measurement to protect the web from excessive local application and to allow the final shrinkage / application profile to deviate. This type of control o can be implemented by technology known per se or, for example, by the operator o by reasoning.

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LO In addition, the width of the web and the effect of the oo o excitation signal generated by the wet end actuator can be measured. The invention may also be provided with individual "M-o control devices which control the self-handling equipment in a manner determined by the upper-level control system 7. Such a single control device may also be a function embedded in the device. for example, adjusting the basis weight cross-section based on the basis weight measurement after drying by controlling either the headbox lip profile, e.g. also uses humidity control or tension control or a combination thereof the shrinkage profile, the basis weight profile, the moisture profile, the tension profile, and one or more of the latter three together with the shrinkage profile can be controlled using methods known per se for adjusting the profiles. Particularly central to the invention is the joint adjustment and / or optimization of the tension and shrink profile. The invention also utilizes software which provides an excitation signal for defining shrinkage in a manner known per se. In connection with the invention, it is novel and inventive, inter alia, to use this excitation signal to control contraction. The invention also utilizes software that calculates the observed shrinkage profile of the web by utilizing wet end actuator excitation signal and measurement data provided by 20 wet end measurement equipment, at least spreading information, and dry end measurement spreading information and the effect of excitation signal in the measurement profile. Thus, in the context of the invention, a focused measurement profile is formed from which the effect of spreading and shrinkage of the cm is eliminated for the control of the wet head actuator, which is preferably sought to be made as fast as possible. Another key signal used in connection with the invention is the calculation of the shrinkage profile, wherein the shrinkage profile c comprises both the effect of the application apparatus and the drying shrinkage, whereby the shrinkage profile is simultaneously controlled and used to align the measurement profiles.

In connection with the invention, it is also essential that the actuator be optimized, which itself consists of known components. In this context, use is made of backlink control methods known per se, or cost function optimizations, or fuzzy control inference rules / calculations, or neural network model control controls. According to the invention, the transverse profile correction is performed either once optimally or sequentially. Physical models of paper structure and behavior are known per se or can be determined by process tests and the mathematics required are also known per se. Typically, the control is made slower than the CD direction, but the arrangement of the invention also allows for 10 quick adjustments.

In a preferred embodiment of the method according to the invention, the actual web expansion is monitored in order to adjust the determination of possible application slip and the desired optimum conditions in different driving situations. According to a preferred embodiment, the width of the web is measured before and after the force application by a suitable arrangement, for example, on the underside of adjacent rolls at both edges of the adjacent rolls to determine the actual web expansion at various cross positions and web position changes. In this way it is possible to verify that the desired application has taken place at least to one edge from the centerline. According to some preferred features 20, the measurement can also be made from the top surface of the roll by camera technology or by monitoring any changes in the pattern of the suction roll through infrared or wire marking etc. The measuring frame used in the invention may be placed e.g. to determine whether the process of the invention has applied as desired

I do not continue to adjust the application in the desired direction. Thus, in the method according to the invention, it is possible, if necessary, to monitor the desired changes in the quality profile, e.g. elastic modulus and / or tensile stiffness, transverse elongation. The elongation sr § can be observed, for example, from a change in the wire marking pattern in the drying section

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After 9. In an arrangement according to the invention, advantageous quality profiles can be achieved with a slight application but with a suitable time-dependent application impulse. In the invention, the improvement of the quality profiles and the adjustment profiles takes place especially in the peripheral regions of the web, whereby the alignment of these measured profiles to the web is improved due to less shrinkage.

By applying the invention, the web shrinkage profile is uniform, making actuator targeting easier and more accurate (mapping). In this way, the effect of the actuators at different points on the machine becomes similar. 10 The improvements achieved in the cross-machine control of the paper machine are e.g. following. Fewer parameters are needed to characterize a process, process identification is easier, faster, and more accurate, complexity is reduced when analyzing controls and problem solving, so it is better to adjust the process.

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The invention allows for a smoother, better tensile-resistant web and thus a higher speed and fewer breaks. On the other hand, the smoother web properties ensure a smoother quality of paper and thus better recyclable paper, thus improving the customer's perceived paper quality.

20

The invention also allows for an increase in production because of the ability to increase the speed, -1-, thereby achieving greater production and more uniform paper over the entire width o w of the web.

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In the method according to the invention, a transverse LO force of a desired magnitude, e.g. application, is applied to the desired transverse position of the web starting from the edges of the web, whereby the properties of the web are modified by at least 0 o. In addition, there may be an area between the edge portions of the web which is not subject to force.

10

In accordance with a further advantageous feature of the invention, the amount of application, i.e. the degree of spreading of the application means, preferably the retaining wheels, is adjusted synchronously on both sides or, if necessary, independently on both sides.

In accordance with the invention, the force effect is achieved by the application means in accordance with a preferred embodiment. According to a preferred embodiment, the force effect is achieved by the spreading effect of the independently operated traction sheaves mounted on the suction roll neck and by the suction effect area, action time, rake angle and zone 10 suction / blow roll of adjustable inflatable traction sheaves. The traction sheaves may also be idlely articulated on the roll axis. According to a further advantageous feature, the pitch of the traction sheaves is adjustable in both directions simultaneously and equally, or separately if necessary. It is possible to arrange the spreading of the traction wheels mechanically / hydraulically / pneumatically / electrically or separately.

According to a further advantageous feature of the invention, the holding wheels are also movable according to the trim, i.e. the width of the web, to the desired position. According to a further advantageous feature of the invention, it is also possible to use a speed difference between the traction sheaves, whereby the web may be prevented from being twisted and the web can be driven by a roll.

cu According to a further advantageous feature, the suction zones o of the suction roller can be provided with a blow option for adjusting the force effect by zones o 25 in both the transverse and the machine direction. In the invention, the desired transverse dimension of the web c is also affected by adjusting the suction LO of the suction sectors of the suction roll in synchronized fashion with respect to both edges or, if necessary, independently oo § from each edge. In accordance with this advantageous feature, it is also possible to adjust the width and / or the length of the suction area of the center of the roll, e.g. in the transverse zones.

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11 and / or the position of the suction area relative to the centerline of the web. Preferably, in this connection, the intensity of the suction is adjusted at the same time and, if necessary, transverse zones. Thus, in the context of the invention, the edge spreading is adjusted to the desired web width at an adjustable spreading speed in synchronized fashion on both edges or, if necessary, independently on both sides.

According to a further feature of the invention, the action areas of the traction sheaves consist of separate suction sectors of at least two and independently controllable. This allows continuous application to the desired sector. Episode 10 may also be implemented by sequencing e.g. two sectors of spreading and then one sector of absorbent, i.e. non-spreading, and further two sectors of spreading, and finally there may be non-absorbent sectors again.

The action time of the force application device used in connection with the invention consists of the running speed of the 15 machines, the usable roll dimensions and through the above sectors.

According to a preferred embodiment of the invention, the web application is performed at an optimum transverse application speed and at an application rate such that the profile of the transverse material properties of the web 20 is as desired, typically as uniform as possible.

o cm With the arrangement according to the invention, the application time 0-5 s, co ...

o ideally 0.1 to 2 seconds at machine speeds of 100 to 2500 m / min.

The application rate to be achieved by the force application device is preferably 0-5%, most preferably x £ 0.2-3.0% of the web width.

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In a preferred arrangement according to the invention, the force of application is most strongly applied in the desired region, whereby the shrinkage or CD stiffness profile is obtained as desired. If desired, the invention can also be used, for example, to increase the overall level of CD stiffness.

5

According to a preferred aspect of the invention, the transverse stiffness of the desired transverse portions of the web, in particular the peripheral portions, is controlled by applying them at a dry solids content of 15 to 95%, preferably 30 to 75%. This, combined with the management of the web edge portions, provides an excellent ability to control the properties of the desired transverse portions of the web during drying / post-drying, particularly the edge portions. Alternatively, in the invention, an alternative, inexpensive, additional application may be used to straighten the web and, at the same time, lightly apply it during wetting and / or coating, for example in the after treatment area.

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The invention can be used in connection with web straightening, for example after a surface sizing unit, provided that the edges can be left unglued or uncoated.

The process of the invention also provides an advantage to the printing and further processing processes due to improved runnability. As the elongation profile becomes more uniform, even the printed product becomes less variable in dimensions, with the benefit of e.g. better print, less wrinkles, etc.

However, the arrangements according to the invention provide for the control of the desired transverse points of the quality profiles, in particular the non-linearity of the edges, e.g.

g adjustment. The system according to the invention provides / improves the transverse properties without adversely affecting the longitudinal web o

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13 properties, since the transverse application of the web in the above dry solids region improves and smoothes, for example: elastic modulus, CD stiffness, smoothness, indirect formation, and absorption profile.

Significant improvements in strength and quality are also achieved with the apparatus according to the invention, because the non-machine direction fibers are straightened without significant recovery.

In the method and apparatus of the invention for changing the properties of a web from the edge, up to the desired web cross-position is applied to the desired amount of application and modification of the web properties by at least one force generating device. According to the invention, by improving the quality profiles of the web, savings can be made in the use of the raw material and / or the runnability potential of the paper is increased without affecting the properties of the paper.

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It is an advantage of the invention that the elastic modulus ellipse generated by the fiber orientation orientation of the fiber region, in particular, can be made more circular by the method and apparatus of the invention. In spite of the strong machine orientation, transverse stiffness can be added, whereby a web with a strongly machine-oriented fiber orientation can be driven at the beginning of the paper or board machine, and later the transverse stiffness can be modified as desired.

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The invention also makes it possible to connect the application process to, for example, a s / v ratio, which illustrates the difference in velocity of the lipstick and the wire, that is, tapping the fibers into the wire or g drawing the wire against the fibers better formatting. The invention thus o attenuates the generation of unfavorable structural properties and breaks o functional dependencies.

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The invention provides several significant advantages. By improving the web quality profiles, the device helps the paper manufacturer save raw material usage and / or increase runnability without compromising paper properties. The arrangement according to the invention makes it possible to reduce the machine direction / transverse strength ratio, i.e. to increase the transverse strength property. In addition, the web can be driven on the wire section at a higher s / v ratio, thereby improving machine strength / runnability. Further, the paper quality, i.e. the web formation, improves when run at a higher s / v ratio. In addition, the transverse shrinkage profile is significantly improved.

The invention will now be described in more detail with reference to the figures in the accompanying drawings, in which details the invention is not, however, intended to be narrowly limited.

Figure 1 shows a solution known in the art.

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Figure 2 shows schematically a roll used in connection with the invention.

Figure 3 is a schematic view of the roll used in connection with the invention in longitudinal cross-section.

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Figure 4 is a schematic end view of a roll according to the invention. Fig. 5 schematically shows an arrangement for implementing the method i o of the invention in a paper machine, g 25 c Fig. 6 schematically shows the jet wire ratio as compared to the longitudinal / transverse tensile strength ratio.

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Figures 7A and 7B show a schematic example of a shrinkage profile (FIG. 7B) after the prior art drying section (FIG. 7A).

Figure 8 schematically illustrates an approach according to the invention for eliminating shrinkage.

Figure 9 is a schematic representation of shrinkage elimination according to the invention.

Fig. 10 is a diagrammatic representation of a wet end to end 10 dry end papermaking and web management apparatus in accordance with one embodiment of the invention.

The prior art device shown in Figure 1 is a drum 10 'or the like. A drying gas P'jn is introduced into the drum 10 ', which is blown from a sleeve provided with the sleeve 15 of the drum to the surface of a web of material to be dried, e.g. In this prior art arrangement, the web is guided over the periphery of the blower drum 10 'or the like. In the method, the web to be dried is supported from the peripheral areas by a rotating edge support 22 'spaced apart at each end of the blower drum 10' and in method 20, the support zone is sealed in the outward direction of the web through peripheral and / or frictional surfaces. The blow drum 10 'is fixedly fixed via the gutter structures 23'. As indicated by the arrow P'out, the extract air is removed from the cm support zone and the arrows P'a indicate the vacuum effect in the region i o of the edge supports. The edge supports 22 'rotate about the axis 27' and at the same time the air system is sealed. For the threading of the web, a groove 22U 'is provided at the edge support 22' of the other end c for the threading ropes. Shaft 27 '

A suction P'a is provided through Ln through which the grip of the web provided by the edge supports 22 'is increased.

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In Figures 2-4 the same reference numerals are used for like parts.

In a preferred embodiment of the invention shown in Figure 2, the device 10 according to the invention comprises a force application 5 acting on the edge areas of the web W 20A, 20B. As shown in the figure, to achieve a spreading effect, the spreading members 20A, 20B are rotated at an opening angle relative to the running direction S of the web W, thereby applying the desired spreading effect to the peripheral areas of the web W. The edge area of the web W directed to the application effect is designated by the reference numeral WS. The application means 20A and 20B comprise actuators 25 and 10 positioning means 14A, 14B, to which the force exerting the education is transmitted and by means of which the amount of application is controlled.

As shown in Figure 3, the device 10 has a rotatable or fixed drum 13 within a substantially region of suction zones 11A, 11B, 11C, 11D, which drum 13 is attached to shafts 12A, 12B at each end. In the arrangement illustrated, different large inlets can be provided in each of the transverse zones 11A, if necessary.

1 IB, 11C and 1 ID, but a more general driving pattern may be provided in central zones 1 IA

and 1 IB corresponding to suction and to marginal zones 11C and 11D with little or no suction or even blowing as needed. Naturally, traction can only be provided in 20 selected zones. The spreading members, i.e. the holding wheels 20A, 20B, are mounted in the bearing housing 27 and provide a local force effect.

· - by spreading when they are turned at an angle W in the direction of travel S of the web

o cm. The spreading members 20A, 20B are provided with pivoting mechanisms 28A, 28B through which their opening angle can be adjusted to provide a desired spreading effect o 25 to the desired transverse web region starting from the edges, g. curved toroidal surfaces.

These curved abutment surfaces are formed in this embodiment into advantageous annular bodies having a space usage o o C \ 17 when viewed in the axial direction. Further, these inner counter surfaces 28AA, 28BB are supported separately from the shafts 12A, 12B in the frame structures. Correspondingly, the guiding surfaces may be formed into curved, circumferential, circumferential bodies formed by one or more pieces to form a pivoting mechanism.

Fig. 4 is a schematic end view of a device according to the invention showing that suction boxes divided into sectors Z1 ... Z% are formed on the retaining wheels or spreading members 20A, 20B, each having its own suction connection 291 ... 29s; Holds under vacuum when causing a transverse force effect on the web. The grooves of such sectorized Z 1 ... Z% end pieces 20A, 20B differ from the circumferential directions shown in Fig. 2 by the shaft 12A; 12B or at an angle to the axis such that the suction of the suction boxes in the adjacent sectors Z \ ... Z§ do not act in the circumferential direction in the region of the adjacent sectors through the grooves. The circumferential grooves shown in Figure 2 15 are suitable, for example, for an application without separate suction sectors. In addition to grooving, prior art solutions for drilling a suction roll, i.e. providing the end piece with drilled sleeves, which may not open into the surface grooves, may be used to apply a gripping suction from the end piece to the web. 20 Transverse grooves, or especially suction holes, also achieve better suction power when the suction does not escape down the grooves.

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In one embodiment of the invention shown in Figures 2-4, starting from the edges of the web W i

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o a transverse force of the desired size is applied to the desired web cross position by the application means 20A, 20B, whereby the properties of the web can be modified g. There may be an unadjusted area between the edge portions WS of the web W

LO power effects. Preferably, the spreading means are axed to shafts 12A, 12B

oo o independently used by drives 25A, 25B, whereby the force effect is controlled o o

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18 in the suction action area, the action time, the pitch angle, and by means of the zone suction / blow roll 10, which is subjected to a force action up to the suction zone of the roll. The retaining wheels 20A, 20B may also be idlely articulated via the pivots 28A, 28B to the shaft 27. If desired, the suction zones 13 of the suction roll 10 may be provided with a blow option for adjusting the force effects. The grip of the web W in the area of the application members 20A, 20B is effected by frictional forces. The plowing angle, i.e. the opening angle of the spreading members, can be adjusted in both directions simultaneously or separately to the desired amount and can be implemented mechanically, hydraulically, pneumatically or by an electric actuator.

10

As shown in Fig. 5, a control and control system 80 is provided in connection with the paper machine PK, which can take into account the effect of applying a force on the edge of the web. System 80 provides improved spread control and stress / length control. The roll 15 as shown in Figs. Fig. 5 shows a steam box 81, humidity measuring points 82A, 82B and web tension measuring point 84. and control information about the base weight 88C is transmitted to headbox control 86.

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o Figure 6 shows the longitudinal / transverse tensile strength and β -formation of the MD / CD, or?

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£ tensile strength curve a. The horizontal axis has a jet wire ratio or S / V ratio.

g As shown in Fig. 6, when the roll according to the invention is installed at 1 Ο, the transverse strength increases, whereby the longitudinal / transverse o

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19 ratio decreases. Because of the higher CD strength, the jet wire ratio can be increased to achieve the same tensile strength ratio as at point A, but the machine directional strength and runnability are improved due to greater orientation and the formation is improved (reduced). The X-axis has a starting position marked at 5 in Xi for a given jet wire ratio, yielding a tensile strength ratio A and a formation B. When installed, the roll according to the invention also better in printing press and 10 better quality or β -formation at point B '. The invention provides control ranges for draws, jet wire ratios, etc. that become wider, allowing for more flexible end product properties and raw material choices.

The shrinkage profile example shown in Figures 7A-7B illustrates a non-linear

15 shrinkage profiles FIG. 7B, which has been observed in FIG. 7A applying a single-wire thread

after the drying section. Fig. 7B shows the shrinkage in the vertical axis and the distance from the front edge of the web in the horizontal axis. As shown in Figure 7B, the shrinkage is more pronounced in the peripheral regions of the web. For paper making and further processing, it is most advantageous for the shrinkage profile to be as flat as possible, i.e. the shrinkage profile is almost straight and in the same position on the vertical axis. The object of the invention is therefore to modify the shrinkage profile as desired. Most often, according to the invention, the shrinkage profile is most preferably repaired at the beginning of the drying section, because the shrinkage occurs on the drying section according to the preferred embodiment of the invention.

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o is applied from the shrinkage areas of the web in the region of the drying section, respectively, 25 g. Figure 8 illustrates a conventional shrinkage profile of graph 100 and follows the elimination of shrinkage at points A1, A2, A3, A4. These points have a shrinkage of 00 co o o o

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20 (N + y)% as a function of position X (i.e. as a function of CD position). According to the invention, stepwise stretching is carried out, for example, in the following way:

Step 1: Stretch the web while holding positions A1 and A2 so that A2 remains in place and A1 moves outward so that the final shrinkage changes to B1 -A2, graph 101.

Step 2: Stretch the web to hold positions B1 and A3 such that A3 remains stationary and B1 moves outward so that the final shrinkage changes to B210-A3, graph 102.

Step 3: Stretch the web by holding at positions B2 and A4 so that A4 remains stationary and B2 moves outward so that the final shrinkage changes to B3 -A4, graph 103.

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Figure 8 illustrates one example of how stretching can be done in accordance with the invention. The order and number of steps, as well as the position of the middle positions except the border, are freely selectable. It should also be noted that stretching from only one point may in some cases be sufficient.

20

Fig. 9 illustrates, respectively, the passage of the web over the apparatus 10 used in connection with the invention. The edge of the web is fixed to the spreader roll 10 at position PII, whereby the cm spacing is directed to the web width x1. As the web passes to position P12, the resulting width x1 has changed to width x2 due to spreading. Corresponds to the first? 25 steps of Figure 8, i.e. the conversion of AI-A2 to B1-A2. In the next step, the grip g P12 is released, whereby the grip is directed to position P21, and the portion to be applied is now x3, which, respectively, widens to x4 as the web advances to position P22. This can be repeated oo g as needed, as in the figure, for example, twice more. In Figure 9, the application is M 0

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21 progressed in order from the edge of the web. Optional according to the invention to provide the desired structure of the paper.

Figures 8 and 9 illustrate the potential for stepwise application with only one device 5, but it is equally possible to use multiple application rollers and also to distribute the steps among them. This can take advantage of the web drying progress in selecting the location of the devices, since the edges of the paper tend to dry slightly earlier, so that the latter roller roller can more effectively correct the shrinkage further from the edge.

10

Fig. 10 shows the web propagation from a wet end to a dry end and web control devices.

Wet End Actuators 111 are actuator controls for cross-section control, for example, a system used to control the dilution water of 15 dilution headboxes, which typically control valves at intervals of 60 mm and which provide a Gaussian curve change to the web. the effect of one actuator extends almost 100 mm to each side of the center. The actuators control a particular property of the web, such as the dilution valves of the dilution headbox 20, in a manner known per se. In particular, it should be noted that the actuator can provide an excitation signal for controlling track widening and contraction. This use of the excitation signal is known per se, as well as detecting the change caused by it and determining the shrinkage profile and targeting the actuator responses to the measurement profile.

g 25 Typically, the track spread and / or shrink before the Wet end measurement 112 equipment is low. However, the known width can be removed from the web,

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because the edge quality is not sufficient for further processing.

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The measurement of the Wet End Measurement 112 may be prior to the application roll 10, for example a cross-section measuring apparatus known per se at the beginning of the drying section. Here, a track is detected before application. The entire profile can be measured and accessed with information, or the locations of the edges of the fault / excitation signal can be measured to determine the correct width of track 5 prior to application. The spreading and / or shrinkage of the web prior to the application apparatus 10 is negligible.

The CDWS (Cross Direction Wet Straining) Roll 13 or holding device 10 is held by the device, or drum 13, in the manner described in the invention to hold the track at least 10 in the middle, but also elsewhere according to the invention.

The Cross Direction Wet Straining Left (CDWSLe) 20A is a left-spreading device 10 that holds the left edge of the web in accordance with invention 15. The application length is determined either by manual layout or by CDWS Optimizer 115. Similarly, the application angle (pitch) is controlled either manually or by CDWS Optimizer 115.

The CDWSRi (Cross Direction Wet Straining Right) 20B is a right-spreading device 20, respectively, of the spreading apparatus 20A.

activities as described above.

cu Typically, the web shrinks before the Dry end measurement equipment. The application o is intended to eliminate the effect of shrinkage, i.e. to obtain a shrinkage profile o 25 in a straight or at least well-established form.

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lo Dry end measurement 113 measures paper properties such as basis weight, oo o humidity, etc. In addition, measuring device 113 measures track width, and measures the effect of the excitation signal generated by the Wet end § actuator apparatus 111, cu 23

The Actuator handler 114 has a plurality of devices and controls the self-handling equipment 10 in a manner determined by a higher level control system. The actuator handler 114 may also be a function built into the device 10 in which case it is invisible in the description herein. In addition, there is a headbox control device, 5 actuator handler 114, in the wet end.

Other CD Control 116 is a regulator for adjusting the basis weight of the cross section, which is based on the basis weight measurement after drying either by controlling the lip profile of the headbox (lip opening in the CD direction) or by controlling the dilution ratio and thereby the dilution valves. This can also be known to be based on the basis weight measurement prior to the drying section, or both, in a manner known per se. Other CD control 116 may also mean controlling humidity or tension, or a combination thereof, in a manner known per se.

The Mapping Generator 117 software produces the excitation signal needed to determine the contraction in a manner known per se.

The software mapping calculator 118 calculates the observed shrinkage profile of the track using the excitation signal from the Wet end actuator 111, the measurement data provided by the Wet end measurement apparatus 20 112, at least the width information and the dry end measurement width information and effect of the excitation signal in the measurement profile.

° This creates a focused measurement profile (from which the effect of spreading and shrinkage o is eliminated) for wet end actuator control (Other CD control), o 25 This adjustment is made to be as quick as possible.

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lq Another key signal is to calculate the shrinkage profile. Shrinkage Pro Brick oo o includes both the effect of the application equipment and the effect of the drying shrinkage.

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24 CDWS Optimizer 115 is the core of the arrangement of the invention. Although this portion consists of pieces known per se, the combination constitutes an inventive whole. The optimizer 115 utilizes conventional feedback control methods or cost function based optimizations or 5 fuzzy control inference rules / calculations or neural network based control rules, which are known per se. Correction of the CD profile, typically application is made either once optimally or sequentially as shown in Figures 8 and 9. Physical models of paper structure and behavior are known or can be determined by process tests. 10 The necessary mathematics is in itself known. Control is typically slower than CD control, but the invention also allows rapid control.

The invention has been described above with reference only to some preferred embodiments thereof, the details of which, however, are not to be construed as being limited in any way.

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Claims (16)

A method in a paper or cardboard machine line after a wire portion in which a web (W) is treated, under which dewatering the web width is transverse in relation to the running direction of the web (W), characterized in that in the process a transverse force effect is exerted by desired size starting from the rabbit all the way to a desired transverse transverse position on the web (W) for modifying the properties of the web (W) with at least one device (20A, 20B) providing power while the web (W) runs supported by a tissue, a drying wire or the like, and that in the method 10 the device which achieves power is controlled on the basis of measurement results from the paper or cardboard web given by the paper or cardboard machine automatically either independently or together with other devices. 2. A method according to claim 1, characterized in that the web (W) for achieving the power effect in the method is stretched across a desired transverse sub-region with a width stretching means (20A, 20B). Method according to Claim 1 or 2, characterized in that in the method at least one half of the center line splitting the web is smaller at a holding area of the device for exerting power than the corresponding half after the device for exerting power when the center line continues in the same T-direction through the rolling width stretching process. o (M o Method according to any one of claims 1-3, characterized in that the web is stretched in the process in the proportion 0-5%, most preferably 0.2-3.0% of the entire web width or locally 0-10%. CL LO 00 § 5. A method according to any of claims 1-4, characterized in that in the procedure § a change of the stiffness ratio CVJ 29 is achieved by measuring a dry web and a smoothing of the drying shrinkage and / or a smoothing of the weighting profile. Method according to any of claims 1-5, characterized in that the method 5 is applied to at least one place in the paper or cardboard machine line along the wire portion. Process according to any of claims 1-6, characterized in that the method is applied when the dry matter content of the web is 10-95%, most preferably 30-75%. 10 Method according to any of claims 1-7, characterized in that the web (W) is subjected to the power action in the book by a drying section in the paper or cardboard machine line. Method according to any of claims 1-8, characterized in that the web (W) in the method is subjected to force action at one or more stages. 10. A method according to any of claims 1-9, characterized in that the stages of the power action in the process are carried out sequentially from the channel of the web (W). 20 11. A method according to any one of claims 1-10, characterized in that t power is controlled in the method together with function and measuring devices in the wet end by means of an impulse signal for control of the width stretching with a function device in the wet end. and / or shrinkage 0 of the web (W). a CL lq 12. A method according to any of claims 1-11, characterized in that the o power force is achieved in the method by constantly holding the web (W) or on the basis of instructions given by optimization control (115). CM 30 Method according to any one of claims 1-12, characterized in that in the method the shrinkage profile, the surface weight profile, the moisture profile and the tension profile or the shrinkage profile and the surface weight profile or the humidity profile or the tension profile of the male (W) are controlled by the width-stretching pavement roller. Method according to any of claims 1-13, characterized in that the stress and shrinkage profile are controlled together or optimized in the method. 10 15. A method according to any one of claims 1-14, characterized in that in the process the width-stretching profile and the actual shape-change profile as the creeping effect is measured, whereby the shrinkage profile can be determined eliminating the influence of the width-stretching and shrinkage. 15 16. A method according to any one of claims 1 to 15, characterized in that the set value of the power profile is controlled in the method for eliminating the effect of the shrinkage profile during drying. δ (M i CD O and o x cc CL m oo oo o ^ r o o CM