FI119067B - Calender and method of calendering a fibrous web, in particular paper or board - Google Patents

Description

119067

The invention relates to a calender according to the preamble of claim 1. The invention relates to a calender according to the preamble of claim 1, and to a method of calendering a fibrous web, in particular paper or board.

The invention also relates to a method for calendering a fibrous web according to the preamble of claim 16.

As is known in the art, calendering refers to a process in which paper is pressed between two or more rolls, whereby, due to mechanical work and heat, the paper deforms both in the plane and in the thickness direction. For coated papers, calendering can often be divided into two steps, pre-calendering and final calendering.

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Calendering mechanisms can be divided into four modes of action: compression, copying, orientation, and transition. For the development of smoothness, compression is the most important factor, which is influenced by the perpendicular compression force and the plasticity of the paper as a whole. The significance of the transition to smoothness within its ♦ · ί # *. Ί 20 is less pronounced and is mainly influenced by planar forces and surface plasticity. Factors that affect gloss include copying, which is affected by • ·: perpendicular forces and surface plasticity, and orientation, i.e. the alignment of oblong and * ·: plate-like particles, which is affected by the target ··· ·. #. · Vertical forces and surface plasticity.

25 • * * * ·! · * Machine calendering is the oldest of the calendering methods. It presses paper between two or more hard rolls. Pre-Calender 2- • · · ,; · The crawler calender consists of a heated thermal roller and a deflection-compensated die-cast roll, both of which have scrapers. There are ·; ··· 30 spreader rolls before the nip. The temperature of the thermal roller is 80 - 120 ° and the line pressure is 80 - 100 kN / m *: · *: When running Newsprint.

2 119067

The difference between a soft calender and a machine calender is that at least one of the rolls forming the nip has a soft surface. The main mechanism of action is compression and copying. Most soft calenders are on-line in a paper or coating machine. The snare roller is scraped and there is a roller before the keys. The Ter-5 motel has a temperature of 100-250 ° and a line pressure of 50-350 kN / r.

Multi-roll calenders are soft nip calendars with a higher number of rolls than soft calendars, most commonly 6-12. The main mechanism of action in supercalendering is compression and copying, in addition rubbing 10 has a small effect. A conventional supercalender is a calender with 9 to 17, normally 12 rolls. The top and bottom rollers are deflection compensated molded rolls. Intermediate rolls are alternately die-cast, water-heated thermo rolls and paper rolls. To process both sides of the multi-roll calender, there are pivot-pi with two paper rolls facing each other. The transverse line pressures vary from 15 nip to one due to the different deflections of the rolls, and the distribution causes its own deviations. pin loads, forces acting on the ends of rollers, eg bearing housings and steam boxes. In fact, super-calendars were developed to produce * load loads. Stretchers, which were also able to slightly influence the line load distribution • »· * · · * *, from the upper nip to the lower nipple, thus reducing the weight of the track.

* · · • * · 20 * ♦,, Supercalendering has long been the only multi-roll calendering method. The development of soft calendars was strongly associated with the development of polymer coatings and the progressive use of polymer-coated rolls also began to occur in supercalenders. It was not until the mid-1990s that change took place; first methods purely based on polymer rolls; the so-called polymer superheroation (su • • · · ** · percalendering with polymer-coated rolls), which also led to the emergence of on- • * * ··· * line applications. Copying and compression can be considered as a calendering mechanism for polymer rolls based calendering. Due to the thinness of the coating, the planar forces have no effect on the calendering result.

30 • * «• · • * •» • · · • * »• · 3 119067

The so-called Janus calender concept based entirely on polymer rolls is known in the art. New features compared to polymer supercalenders are higher temperatures, higher line pressures, and generally inverted roll stiffness, i.e., upper and lower rolls are polymer coated deflection-compression rolls. The concept also includes two-body options. The spindles are no longer spindles because the coating thickness of the polymer rolls does not vary, as does the paper rolls in the supercalenders. The rollers are secured from their bearing housings, which are also combined with pin load relief. In designing the rolls, particular attention has been paid to minimizing the weight of the rolls in order to keep the line pressure difference between the upper and lower nip 10 as small as possible. This has also been achieved by splitting the rolls into two frames, which results in easier one-sided control and a lower structure, but with higher investment and operating costs. In the shared stack, the free export between the tracks also causes the track to dry excessively. The temperature of the thermal roll is 150 °.

15

Also known in the art is the so-called OptiLoad calender, which incorporates all of the above-mentioned features as well as a special load system. All intermediate rolls in the Op-tiLoad calender have the same characteristic deflection, allowing them to be fully relieved without suffering a transverse line pressure profile • · t * · "20. The OptiLoad equalizer rolls ensure a steady line pressure profile and * to compensate the weight of the entire roll • Complete track weight • · • ·

Blending means that the same line pressures * • · • · · M can be used on all nipples. The amount of relief can also influence the pressure difference between the upper and lower nip »·· • · and thus e.g. The loading system brings with it 25 by far the widest calendering windows compared to all other calendering methods * * • · ♦ ί.ϊ ί

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• a • · · »·

A calendering mechanism for long-nip calendering can be considered to be copying and orientation. Due to the low elasticity of the coating; · /, 30 the compression is very low. One of the prior art long- • ♦ • ·; The staple concept is a calendering concept marketed by the applicant under the trademark OptiDwell • • ♦ • · 4 119067. It consists of two different long-nip calendars: the OptiDwell Shoe ™ calender, which shoots with shoe press technology, and the OptiDwell Belt ™ calender, which is based on roller / belt technology. The shoe calender concept utilizes known shoe press technology for the press. The shoe roll is so called.

5 SYMBELT ™ Roller. The shoe roll consists of a shoe, loading elements, lubricating oil system and strap. In the shoe roll, the belt change has been made simple; you do not need to remove the roll from the machine. Teim roll is a known technology in soft calendars. It may be a water, steam, oil or induction heated roll.

10 The width of the nip is determined by the width of the shoe. The length of the shoe can be up to 275 mm. The shoe nip allows the nip width to be stabilized regardless of load, roll diameters and belt characteristics. This allows the calendars to optimize dwell time and nip pressure completely independently of each other.

15

The belt calender consists of a standard soft calender thermo roll, a belt roll and a counter roll, which can be either hard or soft. The strap wraps the counter roll and. , via the steering / tensioning rollers. The simple design of the belt loop also enables the modernization of old machine and soft calendars into belt calendars.

! 20 Without belt, the calender can be used as a regular machine or soft calender. . depending on the model.

• · »» »i • m · • · • · · * · ·

In belt calendering, the nip time (nip length) and nip pressure depend on the line load • · * «* ·· and the belt elasticity (hardness) as well as the soft calender. 25 on the hook. In the belt caliper, the nip varies in length from about 10 to 40 mm and the nip pressure is 5 - * * · * ”* 20 MPa. In the soft calender, the corresponding values are about 5 to 15 mm and 5 to 50 MPa depending on the coating * * · and line load.

··· •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• The calender includes guide and / or belt tensioning rollers, which are rotated around a metal belt. The length of the nip is determined by the positioning of the guide rollers and / or the counter 119067, while the nip is subjected to a contact pressure that can be adjusted from 0 MPa to about 70 MPa. The nip can have a length of 10 mm to 3000 mm and a temperature in the nip of about 50 ° to 400 ° and a metal belt thickness of 0.1 to 3 mm.

In fibrous webs, the boundary between paper and paperboard is sliding and can be divided into two classes by basis weight: single-ply papers with a basis weight of 25-300 g / m2 and cartons made with a multilayer technology and 150-600 g / m2. As noted, the boundary between paper and board is sliding because the lightest board is lighter 10 than the heaviest paper. Usually paper is used for printing and cardboard for packaging.

The following descriptions are examples of current values for fiber webs and may exhibit considerable variations in the values given.

Mechanical pulp or wood-containing printing papers are newsprint,. , Uncoated Magazine Paper and Coated Magazine Paper.

• Newsprint consists either entirely of mechanical pulp or may contain low levels of bleached softwood pulp (0-15%) and / or recycled fiber. ·; ** t * replace mechanical pulp. General values for newsprint should be as follows: 40 to 48.8 g / m 2, 0 to 20% ash content, PPS S10 «* · ** roughness 3.0 to 4.5 µm, Brendtsen roughness 100 to 200 ml / min, density 600-750 25 kg / m3, lightness 57-63% and opacity 90-96%.

Uncovered magazine paper (SC = supercalendered) usually contains ί **: mechanical pulp 50-70%, bleached softwood pulp 10-25% and fillers; ** *; 15-30%. Typical values for calendered SC paper (including, inter alia, SC-C, 30 SC-B and SC-A / A +) are 40-60 g / m2 basis weight, ash content 0 -35%, Hunter- Φ Φ φ φ t φ Φ Φ * ··· Φ 6 119067 gloss <20 - 50%, PPS S10 roughness 1.0 - 2.5 μιη, density 700 - 1250 kg / m3, brightness 62 - 70% and opacity 90 - 95%.

Lightweight coated magazine paper (LWC) contains mechanical pulp 40-60%, bleached softwood pulp 25-40% and filler and coating agents 20-35%. The general values for LWC paper are as follows: basis weight 40 -70 g / m2, Hunter gloss 50-65%, PPS S10 roughness 0.8-1.5 pm (offset) and 0.6-1.0 pm (roto), density 1100-1250 kg / m3, brightness 70-75% and opacity 89-94%.

10

General values for machine finished coated MFO paper may be as follows: basis weight 50-70 g / m2, Hunter gloss 25-70%, PPS S10 roughness 2.2-2.8 pm, density 900-950 kg / m3, brightness 70-75% and opacity 91-95%.

Generic values for FCO (film coated offset) paper may be as follows: basis weight 40-70 g / m2, Hunter gloss 45-55%, PPS S10 roughness 1.5-2.0 pm, density 1000-1050 kg / m3, brightness 70-75% and opacity 91-95%.

General values for MWC (medium weight coated) paper may be as follows: • 20 · 70 g / m2, Hunter gloss 65 - 75%, PPS S10- roughness 0.6 - 1.0 pm,. density 1150-1250 kg / m3, brightness 70-75% and opacity 89-94%.

* HWC (Heavy Weight Coated) has a basis weight of 100-135 g / m 2 and can even be used more than twice.

25 * ♦ * * * •• j: Pulp wood-free printing papers, ie fine papers, are coated • • * ··· * non-coated and coated cellulose-based printing papers with a mechanical pulp content of less than 10%.

• Unbleached pulp-based printing paper (WFU) has bleached birch • ·; pulp 55-80%, bleached softwood pulp 0-30% and fillers 10-30%.

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• ♦ 7 119067 WFU values range from 50 to 90 g / m2 (up to 240 g / m2), Bendtsen roughness 250 to 400 ml / min, lightness 86 to 92% and opacity 83 to 98%.

In coated pulp-based printing papers (WFCs), the coating amounts vary widely depending on the requirements and the application. The following are typical values for single and double coated pulp based paper: 90 g / m2 coated once, Hunter gloss 65-80%, PPS S10 roughness 0.75-2.2 pm, brightness 80-88% and opacity 91-94% once coated, 130 g / m 2, Hunter gloss 70-80%, PPS S10 roughness 10 0.65-0.95 µm, brightness 83-90%, and opacity 95-97%.

For release papers, the basis weight ranges from 25 to 150 g / m2.

Other fine papers include: packaging papers (Sackkraft), tissue papers (Tis-15 Sue) and wallpaper (Wallpaper).

The board is made of pulp, mechanical pulp and / or recycled. . weather. The cartons can be divided into e.g. to the following main categories • · «! *. by. Corrugated cardboard with a liner and a fluting board; • «* • * · * ^ 20 cardboard boxes, which are used to make boxes, boxes, etc. liquid packaging boards • · Ä # (FBB, WLC, SBS); graphic boards, e.g. cards, maps, folders, covers, cover * · · • * · *** / net; Wallpaper base.

BACKGROUND OF THE INVENTION Zone adjustable rollers are known in the art, comprising a fixed central axis 25 and a rotatable jacket supported by hydraulic loading elements embedded in it. holes drilled in the center axis. Zone adjustable rolls for calendering • · * ··· * applications usually have either • cast iron or polymer coated cast iron. The sleeve rotates the bearing support:: Mana, which bearings can attach the sleeve to the shaft position, or the sleeve: V. 30 may be self-loading, whereby the sheath may move freely in the nip direction. One such prior art zone adjustable roller is a trademark of the applicant. • ♦♦ • «8 119067 kg SymZ marketed zone adjustable roller, which mainly uses piston-mounted hydrostatic bearings and has one oil pressure coupling field element. In this application, the loading pressure also provides hydrostatic bearing lubrication. In some applications, self-loading rollers are used to connect the zone-adjustable rollers, thereby eliminating the external load cylinders and thus simplifying the construction. In such rollers, the bearing is mounted with a load ring which can move freely in the nip direction, and the load elements are located between the movable ring and the stationary shaft. Also known in the art are zone-adjustable corresponding rolls 10, which are shaped so that their load is profiled in the transverse direction of the web travel, i.e. so-called deflection compensated rolls, which differ from conventional zone-adjustable rolls in that each equipped with its own öl-rail feed system.

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Reference may also be made, in the prior art, to European Patent Publication No. 698684, which discloses a shoe-loaded deflection compensated roll comprising a stationary roll shaft with a rotatably tubular roll casing mounted on its roll bearings by end bearings. The roll sheath of the deflection compensated roll described in this publication is made of a fiber reinforced composite material with a good circumferential stiffness of the roll sheath and a low stiffness between the roll sheath and the shaft. · · Ί ·! : nipple-plated hydraulic load-bearing shoes acting on the inner surface of the roll shell and supported on the roll shaft by a hydraulic roller pressurized with roller pressure medium, which adjusts the pressure of the applied fluid medium to the nip pressure in the axial direction of the roll. .

• · «* *« * · '· *: As is known in the art, paper thickness variation has been adjusted for calendering • ·; ***; • · * 30 influence on the elimination of paper machine fluctuations other than finished • * *. *. making the rollers used as rigid as possible. This has led to state of the art solutions in the prior art. * 9 119067, that, depending on the quality of the rolls, the thickness variation in the web has changed, depending on how well the rolls have been made and how the rolls have been handled.

5 The so-called modern calenders known in the art, in which the cross-directional adjustment of the machine is implemented with a deflection-compensated roll, have a speed of adjustment that allows the roller pressures to be actively adjusted, even at roller rotation or even higher frequency. However, one disadvantage of these known solutions has been that the large mass of the jacket 10 used causes a significant dynamic delay and the actuator requires a high power.

One problem in prior art multi-roll calenders, i.e. calenders, in which a calender roll or rolls consist of a plurality of commonly-piercing rolls, wherein the calender has a plurality of overlapping calendering nips in at least one roll stack, has been associated with only the top and bottom of the roll stack. . the roll nipple are closed. This method of driving is called the so-called matt mode.

• · * • · ® I *. However, this method of driving is not suitable for all types of multi-roll calendars, because the nipples used • · · * * 20 must be at least mutually separate and • · · ...

φ φ puma compared to the deflection of the deflection compensated roll has been too oral * In multi-roll calenders known in the art, another problem may also have been that under roller loading in applications where nip load is realized by high frictional frictional cylindrical friction on the lower roller guides and the intermediate roller joints, whereby the line load distributions of the nipples have been difficult to control so the web profiles are not always achieved the desired • · · ϊ *: level.

On the other hand, one problem with calendering has been a deflection compensated roller; weaknesses in profiling ability, particularly in the peripheral regions of the web. Poor web profile • · · * f ίο 119067 causes wreckage and runnability problems with post-calender actuators such as reel and winder. One problem with controlling the edge areas of the web has been that the web is generally not transverse when coming from the pre-calender papermaking step, but the edge 5 areas have been thicker or drier.

One problem with calendering has been that when calendering webs of different widths, for example, soft calendars have had to cool the surface of the soft roll of the soft calender so that it is not damaged when the web has been larger than roll width. the roll surface too much in areas where the web cannot reach.

One problem with prior art multi-roll calendars is also their high price because when the multi-roll calender is equipped with, for example, 6-12 15 rolls and calendar rolls usually use three different roll types: deflection compensated rolls as top and bottom rolls, thermo rolls and polymer rolls many different types of rolls were needed, and so many were required. . different spare rolls.

The calender may have been subjected to uneven loading due to variations in web thickness. . break the roll surface. For example, one micrometer throw at the web thickness • · * • · «" V causes a load of 5 kN (0.5 MPa). If the paper remains rotated around the roll, it * * * produces a roll profile of up to 50 µm, resulting in roll damage. »*** which has had to replace the roller or rebuild the coating. As a result, these costs may have been high because, for example, the downtime of an online calendar • * # · causes a downtime for the whole line, which can easily increase up to« · * · '' € 200,000 per day.

Fiji One problem with prior art super-calendars 30 has been that, as paper machine speeds increase, the super-calender is often *. ·. : formed as a bottleneck in the process, which has either slowed down the speed or has not achieved the desired quality at too high speed «* · u 119067. As a result, efforts have been made to increase the speed of the papermaking machine by modernizing and improving process calendars, while also improving the quality of the end product. On the other hand, the high speed of paper machines may also have caused the fish-5 blade to vibrate, thereby damaging the surface of the soft rollers used in the super-calender, resulting in increased roll replacements, which has reduced calender capacity and naturally increased roll maintenance costs.

One problem with calendering is nipple vibration, the so-called 10 barring phenomenon, which causes caliper wear on the roller surfaces and sometimes limits the calender's running speed and causes noise. One way to solve this problem has been to change the relative position of the contact between the rollers. That is, for example, the calender intermediate roll has been moved horizontally so that the point of contact between the rolls changes significantly with respect to the wavelength of vibration. However, this is inconvenient because, in the case of deflection compensated rolls, the roll moving mechanism becomes heavy and expensive, and furthermore, it can reduce the rigidity of the roll support and thus cause additional vibration.

It is an object of the invention to provide a calender and a method for sharpening a fish web of fiber, which eliminates, or at least minimizes, the prior art disadvantages described above.

• · • 1 · • · · ··· 1 ···

In order to achieve the foregoing and further objects, the calender according to the invention is essentially characterized by what is stated in the characterizing part of claim 1.

· »» • • • · ·· ♦ • · • m \; The method according to the invention, in turn, is essentially characterized by what is stated in the characterizing part of claim 16.

30 ♦ · · 12 119067

The invention is applicable to many different types of calendars, such as soft calendars, multi-roll calendars, and single and double roll calendars, which usually have at least two calendering nips per roll. Furthermore, the invention is also applicable for use with metal belt calendars. The invention is applicable to all grades of paper and board. The invention is particularly suitable for a speed range of 400-3500 m / min. The invention can be applied generally in both known philosophies of calendering, i.e. in that the calender provides a uniform treatment, whereby profiling of the web is achieved by a headbox. On the other hand, the invention is also suitable for web profiling with a calender, although this requires 10 slightly more complex controls, but profiling even with headbox accuracy is possible when calendering according to the invention.

According to the invention, the composite shell roll is able to follow the shape of the counter roll on its outer surface, whereby the composite shell roll has a ratio of allowable deflection 15 to the length of the roll greater than 0.20 mm / m. According to the invention, the weight of the sheath of the composite roll varies with diameter and length; the weight of the composite roll shell is about 200 to 1000 kg and the roll roll body weight is about 2000 to 40000. # kg, wherein the weight ratio of the sheath to the weight of the roll body ranges from about 1/10 to 1/40 (0.1-0.025).

• · «'* 20 *

According to the invention, the calender may use a bent roll, the roll casing being flexible, allowing the roll to be bent on the profiling side with less pressure on the corresponding shoes and, if the width of the web being produced is constant, * * * ·· · * Load shoe distribution can be selected accordingly. Thereby, at the ends of the roll, at a certain distance there are at least one means for implementing the bending. The means are preferably located on the opposite side of the profiling members. There may be * ... * more bending means at a given angle relative to each other, for example at an angle of 30 °. The invention thus enables the peripheral area of the roll to be protected when manufacturing the roll • •; ***; • narrower web, since the desired clearance between the roll and its counter roll can be made in the peripheral areas, so that the calendering nip rolls do not touch ♦ «in the peripheral areas and the hot roller thus damages the soft roll surface. · * • * 13 119067, whereby variable web widths can be driven by adjusting the play to the edge length of the roll required by the web width being driven.

The invention also provides the advantage that the problems occurring at the web edges have been resolved, since the loading pressure can be transmitted in the shoes so as to obtain the desired load, whereby problems caused by the bearing of the roller bearings can be solved by loading the load differences caused by the bearing support can be compensated.

10

The invention makes it possible to profile the calendering in the transverse direction of the web, or exactly the same load across the web. When used as a roll in a calendar, a composite diaper roller can be loaded on the composite diaper longitudinally with each load shoe at a desired pressure such that a desired load profile is obtained. This also provides a better web thickness profile as the transverse thickness variation is reduced. In this way, the wreckage is reduced by up to 30-50% with a more even roll quality variation,. evening out.

In the invention, the calendering load that is profiled across the web also improves the soft coating resistance of the oncoming nipple roll, since 1 can be used to eliminate both calender errors and the web. · ··· 1 errors that may have occurred.

According to a preferred embodiment of the invention, the elimination of the machine-directed packing of the web is achieved by actively adjusting the calender roll strain ** pressure based on the web thickness profile measurements. The web thickness · "· 1 profile is measured, for example, with a movable transducer, whereby the measurement also includes a · · 1" · machine direction component and this machine direction component is separated from the · · 30 measurement data by synchronization and signal processing. I saw the machine direction * 1 *. 1, on the basis of the thickness variation information, the zone roll of the invention can be modulated with a suitable amplitude and at a suitable stage, for example, by a sine wave opposite to the thickness variation for the load control. This modulation can be accomplished either by valve on roller loading shoes or by running the same wave on all valves.

5

In a preferred embodiment of the invention, a roll is provided which has two different modes of operation, both fixed and movable, wherein the roll casing is either fixed or movable. In this case, lighter rolls can be used, resulting in lower frictional forces. In addition, the profiling result, and at the same time the quality, improves, resulting in cost savings. The calendar can then be closed with the entire roller when the belt roller according to the invention placed in the lower position is in a fixed mode, i.e. its mantle is not moving, and the belt roller in the upper position is in a movable mode. In solid form, the bearing forces can be measured from the plain bearing pressures.

In this embodiment, the calendering nips are closed by raising the lower lifting cylinder 15 upwards as long as each nip closes from the bottom up. The movement of the Alanos Tos cylinders is stopped against the mechanical stop, whereupon the upper zone coil jacket has risen some distance upwards, and as the nipples are thus closed,. , load the nipples by pressurizing the zones of the upper and lower belt rollers to pressures corresponding to the desired • · * f · · '* line load. The correct level of the lower nipple line load is controllable by measuring the lower roller bearing pressures, by adjusting the pressures in the zone roller, •, to change the measured bearing pressure to the calculated values. This application also allows partial nipple driving, for example matt driving, the loading of the upper and lower nip takes place in the same manner as known per se from the state of the art by using a fixed belt roller 25 with a movable jacket against the counter roll.

The following is a summary of some of the benefits that will be achieved. through the invention. In the context of the invention, the use of a composite jacketed belt roll as a calender roll reduces broke because the composite jacketed belt; V. When calendering with a 30 coil roller, the thickness profile of the paper becomes better than with conventional rolls, especially edge control, whereby the web does not need to cut the edge band or at least the cutting width. can be reduced. At its best, the edge rolls are made into commercial paper. In addition, the improved web thickness profile achieved by the invention removes / reduces the wreckage caused by paper old age and rolls.

5

Due to the flexibility of the composite jacketed roll roll used in the invention, after production breaks and stoppages, production is faster, since there are no deformations due to temperature and the temperature profile of the roll is stabilized more quickly. Due to the improved roll profiling capability, the 10 roll roll grinding intervals can be extended, which increases the calender efficiency as the time required to roll roll changes is reduced. In the invention, the caliper nip provided with a composite jacketed belt roller has a better local overloading time than conventional rolls because the jacket resists a thicker local area while maintaining a local constant nip pressure, thereby avoiding coating degradation and wear, resulting in longer grinding intervals. The improved profiling made possible by the invention can better counteract the errors of the counter roll and also extend the grinding intervals of the counter roll. In addition. . the vibration damping properties of the composite sheath are better than the casting

• · I

l *. with an iron jacket for less peripheral oscillation • * ·· I 20, reducing the risk of barring occurrence. Vibrations and damping of the diaper and. , between the coating in a roller according to the invention is better than with a casting roller and a coating • · ·! ", *.

The advantages described above obtain an advantage in production either by improving the machine,. 25 time efficiency (less downtime) or improving production efficiency • * · * '*. * (More paper for sale). In addition, the improved thickness profile obtained by the invention also improves other web properties, e.g.

·· · • *. · Gloss, etc. In addition, accelerating the reduced ··· mass of the roll used in the invention to driving speed requires less maximum power from drives, 30 After use, the composite jacket can be further utilized by reusing it, such as a felt guide roll.

• * 16 119067

Many different types of advantages are achieved by implementing different calendering concepts according to the invention. In soft calenders, the thickness profile can be corrected with a single nip and a better profiling ability when used as a second roll of the nip in the zone roll of the invention. In hard calendars, the composite diaper hard-5 can be coated, whereby one nip provided with a roll according to the invention provides a thickness profile correction and better profiling capability. In metal belt tantrums a better profiling capability is achieved. When used in multi-roll calendars, the composite diaper roll is used to top the calender as a top roll roller, and profiling is achieved in the first nip, after which other calendering features can be focused on other calendering properties, such as gloss. For super-calender applications, using a composite jacketed roll roller as a top roller, profiling in the first nip can be accomplished, and then focus on other calendering features such as gloss enhancement. The invention can also be used in calendars by placing a composite jacketed zone roller between two thermal rollers, which results in better profiling and thus cost savings by using cheaper rollers compared to prior art arrangements of two belt rolls # #. replaced by one.

The invention will now be described in detail with reference to the accompanying drawings. However, the details of the invention are not intended to be limited in any way. Some preferred embodiments of the invention are schematically illustrated in the figures.

• · • · ··· ,. Figures 1-6 schematically illustrate some embodiments of the invention as calender rolls • 2 · * 1 ·,, ** · 2.

7 illustrates schematically an embodiment of the invention using: 3: a flexible roller.

30 »· t • ♦ • · · • · 2 ♦ ·· 3 • · 17 119067

Fig. 8 schematically illustrates one bearing arrangement for use in connection with the invention.

1-6 schematically illustrate some applications for calender rolls 5, wherein roll roll stack 10 comprises at least one composite jacketed zone roll 15. In Figures 1-6, roll roll thermo rolls are designated by reference numeral 13 and possible polymer rolls by reference numeral 17 and the figures show only one roll stack 10 in each embodiment, the calender may, of course, comprise multiple roll stacks, and the number of nips 10 may differ from the embodiments shown in the figures. In the figures, the calendering nip is denoted by N and the web is denoted by W. The nip is denoted by NK. The composite jacketed belt roll 15 comprises a shaft 11, a load shoe 14, and a composite jacket 16 which is carbon fiber reinforced epoxy and provided with a metallic coating. The composite-15 jacketed belt roll 15 is preferably of the type disclosed in EP-A-698684.

. , Fig. 1 is a diagrammatic representation of an application that has been upgraded from twelve rolls to eleven rolls or ten rolls. In the pattern, * * ♦ ··· * * 20a shows either the first or last nip N of the track 10, one of which or • *,. both are modernized by arranging commands for the • • · I · I ...

* * *, * Positive Sheathed polymeric roller belt roller 15, whereby the cast iron sheathed bending compensated roller and paper roll, which are thus replaced by 25 composite belted belt rollers, can be dispensed with with the former construction. Thus, the first * · * · * ·· · and / or the last calendering nips N of the calender roller 10 are formed into a composite diaper • · ** ·· * profile roller nips 15, thus providing the technology: * J-level profiling plus a nip N has a calendering power of: ***: significantly better than a prior art solution.

SV. 30 ♦ • • · ♦ 18 · · 18 11 18 119067

In the calender roll stack 10 shown in Figure 2, two different roll types are used: terra rolls 13 and composite jacketed zone rolls 15. This application achieves a good calendering profiling capability and a low cost calender due to the smaller number of rolls. The application utilizes composite-belted roll rolls or deflection compensated rolls 15 with a carbon fiber composite, which provides excellent profiling capabilities. With the calender shown in the figure, it is also possible to drive a partial nip in either the top or bottom nip or in the second and third nip. Each shoe row 14 of roll 15 is individually profilable, so that all nips N are profiled as needed. The shoes 14 of one roll may also be overlapped with the other row (not shown).

Figures 3 and 4 show a six-roll calender roll stack 10 in which the swivel nipple NK can also be used in place of the second zone roll 15 (Figure 3), or the swivel nipple NK can be implemented by inserting the third and fourth rolls into thermo-15 rolls FIG. 4. This provides a cost-effective calender with excellent profiling capability and a wide variety of sub-nip driving modes. Profiling is at its best in the first nip, so in a cost-effective manner, the second nip may use a roll which is not profiled in the cross-machine direction, but which is, for example, 1 to 8 zones • · · * *. Alternatively, the second composite roller can be made completely 1-8 belts, as the elastic sheath itself allows for a steady line load! ·· * · to the second, third and fourth nipples. This results in additional cost savings due to fewer valves and associated controls.

Mt * »• · M · 25 Figure 5 shows a calender solution that has achieved a good prototype for the calender. The calender roll stack 10 has a hard roll band 17 as its top roll 17. Good profiling can be achieved right from the first nip because * · * · *. it has a composite jacketed roll roll 15. The other nip provides a pack • ·. · **. the nose profile so the other nip increases the gloss of the web with a steady line ··· 30 load. The elastic jacket of the composite jacketed belt roll 15 allows a uniform line load of «·» *, \ nip, since the elastic jacket follows the shapes of the reel-shaped thermal roller 13 and thus the force in each shoe is transmitted to the nip N. the fact that a good profiling capability can also be realized in a conventional super-calender roll action calender. In the calender roll stack 10 of Figure 5, after the first thermal roll 13, two polymer rolls 12 follow each side of the turning nip NK, followed by a thermal roll 13 below which a polymer roll 12 is located, and a bottom roll roll strip roll 17.

In the embodiment shown in Fig. 6, the roll stack 10 has thermal rollers 13 positioned above and below the composite jacket 10 belt roller 15 and the corresponding roll arrangement is implemented after the pivoting nip NK.

7 illustrates an embodiment of a composite jacketed belt roll 15 in longitudinal cross-section, which shows in FIG. 7 the structure of roll 15 in this embodiment reduced. The sheath 16 of the roll 15 is composite, so it is flexible, with a bending side T positioned above it and a profiling side P below. The roll 15 ends at a certain distance carry out the bending. . at least one means (not shown), preferably means for performing the bending, is · · 1 2 * positioned on the opposite side of the profiling member. There may be • ψ · * · · * 20 more bending members at a given angle relative to each other, for example 30 °. , placed in the ground. In this case, the calender may be run webs of different widths by bending • • 1 · 1 · Ia edge regions of the diffractive side by T kalanteroimrsnipistä out of the way, • • · · · ♦ that the roll 15 has to select the clearance between the nip contact area kuomutus- m • *** "shoes 14, so that when bending on the profiling side P, the corresponding pressure of the corresponding t 25 pressure is lower.

Fig. 8 is a schematic representation of a roller bearing arrangement, with a sliding bearing 2 · • added to the bearing 21 to eliminate the barring effect, along with the roller * 1 ·. an actuator 22 for moving the diaper 16 horizontally. In the figure, the jacket * 30 16 has moved to the extreme position, whereby a nip displacement of the nipple N • occurs in the nip N. In this connection, the counter-bearing of the bearing can be implemented, for example, with a 50mm stroke, and the arrangement can be implemented in new equipment and in connection with the modernization of calendars. In the embodiment shown in the figure, the bearing is formed in connection with a sliding bearing 5 of a deflection-compensated self-loading roll by changing the order of the vertical and horizontal bearings. The vertical bearing is a plain bearings with a normal shock-free roller, and the horizontal bearings are a 50mm stroke-bearing slide bearing with position control. Horizontal bearings are used to move the sheath of the roller during stroke or during stroke change. Thus, the relative nip contact point of the rolls 10 is displaced, for example, by about 20mm, which is sufficient to eliminate or at least significantly reduce nip vibration. In the embodiment shown in the figure, horizontal bearings have been added to the bearing, whereby the stroke of the vertical bearing of the roller may have been reduced, and thus the strength of the roller shaft obtained. Only two pieces per head are needed for the balance stroke. The nipple-facing laa-15 wheelbase is adjusted to accommodate the roll diaper so that it is sufficient for the set horizontal stroke.

. , The invention has been described above only in some advantageous application examples. however, the details of which are not intended to be narrowly limited by the invention.

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Claims (23)

2i 119067 A calender comprising at least two calender rolls forming a calendering nip (N) between them, one of which being a heated calender roll, i.e. a snare roll (13), of which at least one of at least two rolls of the calender (10) is a zone-adjustable calender roll ), the jacket (16) of which is a composite material, the zone-adjustable roll (15) comprising a roll body comprising 10 loading shoes (14) disposed in parallel along the shaft and the shaft (11) in at least one row parallel to the shaft (11); a diaper having an adjustable diaper position through the load of each load shoe at a speed of 400-3500 m / min, characterized in that the calender has a weight ratio of the diaper (16) to the roll body of the calender and that in the calender 15) is a stiffener-15 workable bending roller equipped with a bending roll in order to provide clearance to the peripheral areas of the calendering nip (N), outside the end areas to be calendered (W) to control the peripheral regions. • * • ♦ * • · · • · •: / · '20 Calender according to Claim 1, characterized in that the calender is a multi roll roll calender, in which a composite-diaphragm zone-adjustable roll (15) is disposed in the lower position of the roll stack formed by at least two rolls. and having in its upper position a zone-adjustable roll (15) of composite diaphragm (*) with movable mantle. Calender according to Claim 1 or 2, characterized in that the zones of the zone adjustable ♦ · rollers are pressurized by the loading members to load the fish blade (1). 14) is fitted ··· • «to be pressurized to the desired pressure. ·: ··: 30 * l 22 119067 Calender according to Claim 1, characterized in that the calender has been modernized to a multi-roll calender by providing a composite-jacketed zone-adjustable roll (15) of the calender roll (15) which has replaced two previous roll rolls when the calender is modernized. 5 Calender according to Claim 1, characterized in that the calender has one or more calendering nipples (N) and that the second roll of each calendering nip is a composite-jacketed zone-adjustable roll (15) such that each loading shoe (14) of the roll is adjustable in load. , so that all calendering nips are profiling. Calender according to Claim 1 or 4, characterized in that the bending at the ends of the roll at a certain distance is carried out by one of the means, preferably on the opposite side of the profiling member, wherein the transverse width of the calendering nip is adjustable. Calender according to Claim 6, characterized in that a plurality of bending means are provided at an angle to each other. • · · ♦ · ® • a Calender according to Claim 1, characterized in that the medicament of the roller • · *: · *: comprises a plain bearing and a scales mounted in connection therewith; to eliminate the barring effect of fish fishing. • · • ♦ · • · · ··· «• a a Calender according to one of Claims 1 to 8, characterized in that the composite diaper roll (15) of the calender comprises separately controllable loading members for longitudinal profiling such that the calender nip (N) ) to adjust the thickness profile of the web (W) passing through the web (W) in the transverse direction. ♦ · * • · * t ·· * a •: ··: 30 Calender according to one of Claims 1 to 4, characterized in that, in the calender, measuring means for adjusting the profiling on the basis of the measurement results provided by the measuring means are provided in connection with the composite jacket roll (15). Calender according to one of the preceding claims, characterized in that, in the calender, a composite diaper belt roll (15) is arranged as a roll forming the first calendering nip (N) of the calender roll stack (10). Calender according to one of the preceding claims, characterized in that the composite diaper roll (15) of the calender is disposed as a roll forming the last nip (N) of the calender roll stack (10). Calender according to one of the preceding claims, characterized in that the composite diaper roll (15) of the calender is arranged as a roll forming a pivoting nip 15 (NK). Calender according to one of the preceding claims, characterized in that the composite diaper roll (15) of the calender is arranged in a Y modem dial to replace the two previous rolls of the roll stack. 20 Calender according to Claim 1 or 2, characterized in that an actuator for restricting the movement of the nipples is provided along the roll stack of the fishes: • m · when closing the nipples from the bottom to the top. ··· • · • · ♦ ·· A method for calendering a fibrous web in a calender comprising: · (10) a calendering of a fibrous web (W), in particular of paper or paperboard, · · · *. ·. * In at least one calendering nip (N) formed between two rolls the calendars being heated by a calender roll or thermo roll (t: (13), wherein in the method of calendering nip 30 (N) calendering the web (W), at least one of the at least two rolls is a zone-adjustable calender roll) 15) having a flexible casing and a composite material having a belt 119067 24 summerable roller (15) comprising a roller body comprising an axis and wherein the calendering nip loading is achieved by means of roller tracks arranged parallel to the shaft in at least one row, (15) the position 5 of the diaper is adjusted through the loading of each load shoe (14) at speeds of from 400 to 3500 m / min, characterized in that in the method the weight ratio of the sheath of at least one roll (15) calendering the web to the roll body is 0.1 to 0.025 and that in the method the calender roll (15) is bent by to provide clearance to the peripheral areas of the 10 calendering nips to the outside areas of the web to be calendered to control the peripheral areas. Method according to claim 16, characterized in that in the method the web (W) is calendered in a multi-roll calender in which a zone-adjustable roll (15) with a fixed sheath and a zone-adjustable roll (15) is positioned in the lower position of at least 15 rolls of two rolls. the jacket of which is movable. A method according to claim 16 or 17, characterized in that: * *: * ·, · In a method for loading the calender, they are placed in the upper and lower positions · *: * ·; The zones of non-adjustable rollers are pressurized by pressurizing Ϊ t: *: the load elements (14) at the desired pressure. • · • · · • · · ··· · · ···: ... ϊ A method according to any one of claims 16 to 18, characterized in that the method comprises modernizing the calender into a multi-roll calender by following a composite diaper zone adjusting roll (15) with a calender roll (15) two previous rolls of the roll stack are replaced. • • · · * · · ··· · ϊ,., Ϊ A method according to any one of claims 16 to 19, characterized in that the composite shell adjustable roll (15) in each calendering nip is loaded through 25 g of each load shoe 119067 to provide a web (W). ) transverse profiling. Method according to one of Claims 16 to 20, characterized in that the cross-sectional width of the calendering nip is adjusted by means of a bending means. A method according to any one of claims 16 to 21, characterized in that the loading elements leaving the composite diaper roll (15) separately by the calender perform longitudinal profiling to adjust the thickness profile of the web (W) guided through the calendering nip (N). Method according to one of Claims 16 to 22, characterized in that the profiling is adjusted on the basis of the measurement results provided by the measuring means. • »• • • 1 · • • • • • • • • • • • ••••••••••••••••••••••••••••••••••• · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·