FI113792B - Shoe roll for calender, e.g. multi-roll calender, for fibrous web, e.g. paper and board web, comprises shell and internal shell-loading shoes - Google Patents

Abstract

A shoe roll (1, 4, 6, 10) comprises a shell (11, 41, 61, 101) of a composite material; and internal shell-loading shoes (12, 42, 43, 62, 63, 103) for profiling the shell, nip (YN, PN1, KN, PN2, AN), and/or fibrous web (W) and for controlling contact in the nip.

Description

113792

multi-roll calender

Flervalskalander 5

The present invention relates to the calendering of a fibrous web, such as paper and board. More particularly, the present invention relates to a shoe roll for a multi-roll calender according to the preamble of claim 1.

Calendering is a method generally used to improve the properties of a web-like material, such as a paper web, in particular thickness profile, smoothness, gloss, surface porosity and translucency. In calendering, the paper web is guided into a nip formed between press rolls pressed against each other, where the paper web is deformed by temperature, humidity and nip pressure, whereby the physical properties of the paper web can be affected by adjusting the above parameters and action time. The good physical properties of calendering result in a better print quality and thus give the paper manufacturer a competitive advantage.

Shoe and / or long nip calendering is calendering in a calender unit in which the nip shape-20 provides a flexible-diaphragm roll having, for example, polyurethane, and a rigid-diaper and t-shirt; between a press roller or a shoe roller with an inner load shoe made of metal: such as steel.

• * »iti • * v 'As is known in the art, shoe rollers are hydraulically deflection compensated zone adjustable track; : 25 and in which the diaper is supported by a non-rotatable roll center shaft by means of a hydrostatic loading arrangement, such as a row of loading shoes, which transmits the nipple force exerted on the diaphragm rotating about the center shaft to the central shaft. The load element is also »» '·' divided into zones, whereby the load pressure can be adjusted to the profile need. 'kaally. The zone division in such a zone adjustable shoe roll may be subdivided into individual elements of the loading arrangement, whereby the number of zones may rise in the roll and load; · More than 60 pads - examples include shoe rolls marketed by the applicant's trademarks SymCD ™ and: SymCDS ™, or a set of load-bearing elements, with 2,113,792 rolls and loads typically having eight zones - examples include the applicant's trademarks SymZ ™, SymZ ™, and Shoe Rolls marketed by SymZLC ™.

Shoe and / or long nip calendering has generally been found to be advantageous for low-gloss, i. Calendering to achieve less than 40 Hunter gloss% paper grades. However, when a higher gloss is required, nip pressure is not sufficient to produce the gloss. With running speeds steadily increasing, calendering is becoming a bottleneck in the papermaking process, and current machine calender units are not delivering sufficient quality. The drawbacks of the present papermaking process 10 are also that the loss of the sweat increases with the improvement of gloss, which requires the use of heavily coated Tainas and / or the use of off-line calendering, particularly multi-nip calendering and soft calendering.

15

Calendering technology is increasingly moving towards on-line solutions, including when it comes to producing higher quality printing papers such as SC and gloss coated papers. Figure 1 illustrates how different types of printing paper are calendered today, and in particular the direction in which calendering can be seen. ·. 20 technology is on its way in the near future.

* · • · • · ·. ·. a. Machine calendering is a calendering unit in which nipples are formed between non-rigid overlapping smooth-rolled metal rolls. In a machine calender, the * nip is typically very small in width and the nip pressure in the nip is relatively large: 25 µm.

b. Multi-roll Calendering with known applications of Super Calendering and: In particular to achieve SC-A and LWC grades, a multi-roll On-Line or I * · 1 Off-Line Calender that achieves virtually the best quality in off-line operation is: calendering in a calender unit in which the nips are formed by a smooth »»: "': roll of 30-surface metal or die-cast rolls and a roll coated with a flexible coating, such as a paper or polymer roll, to form a wide nip. • · Flexibility *: vapintainen roll conforms to the surface of paper and presses the paper forms counterpart • · 3 113792 evenly against the smooth-surface metal roll. Due to the flexible roll, the calendering time is also longer, which is why the paper machine now needs to be equipped with up to three multi-roll calendars to ensure sufficient capacity. The multi roll calender nowadays typically has one to two rolls and 10 to 12 nips. The Super-5 calender has a so-called "handle" to process the sides of the web. swivel nipple with two flexible rolls facing each other. Line pressure increases in the multi-roll calender from the upper nip to the lower nip due to the gravitational pull. By using roller relief, this increase in pressure can be compensated for. Such roller roller calender is a roller calender marketed by the applicant under the trademark OptiLoad ™.

10 c. Soft calendering is calendering in a calender unit where nipples are formed in the same way as in a multi-roll or supercalender between a smooth-rolled metal roll and a roll coated with a flexible coating to form a wide nip. In the soft calender, each nip is formed by separate pairs of rollers, whereby the nip pressure of the individual nips can be adjusted per nip, or between the pairs of rolls of separate tracks, whereby the nip pressure can be individually adjusted. The Soft Calender can be used as an On-Line Calender and can replace paper machine machine calendars. To process both sides of the web in the calender, the order of the pairs of rolls or rolls forming consecutive nipes with respect to the web is inverted so that the flexible surface roll or the flexible surface rolls is exposed to the web. 1. ·. 20 on each surface.

The primary object of the present invention is to eliminate or at least minimize the weaknesses and drawbacks associated with current; 1 · multi roll calendering, and to provide a new intermediate and / or roll to improve the profiling of a fiber web: · 25 roll roll calenders, such as Line or Off-Line calendars, super calendars and / or soft calendars.

This object is achieved in accordance with the invention by a shoe roll such as those mentioned above, Y: the main features of which are set forth in the characterizing * 1 ": 30 parts of the appended independent claim.

> »4 113792

Thus, the invention is based on the novel and inventive idea that the shoe roll loading and profiling shoe rows are stiffened in the direction of the shoe roll nipples, and that the shoe roll sheath is a composite material whose properties are selected by fiber orientation such that the sheath is circumferentially stiff.

5

Among the advantages of the invention, it can be mentioned that individual shoes or a set of shoes that load the shoe roll diaper and are spaced circumferentially apart can change the nip load, i.e. increase and / or lighten the nip load, thereby providing successive nipples that similarly profile and enhance the calender-10's output. The invention also makes it possible for the shoe roll to now make profiling nips of all the nipples of the multi-roll calender, and for the top and / or bottom roll of a multi-roll calender, such as a super-calender, to now be profiled top and / or bottom.

According to a particularly preferred embodiment of the invention, the composite material is preferably selected from the group consisting of: continuous fiber reinforced plastic; glass fiber; carbon fiber / epoxy composite.

In order to make the diaper stiffer in the circumferential direction than in the axial direction, in a preferred embodiment of the invention, the fiber orientation of the composite material is implemented so as to be ·. ·. The more advanced portion of the fibers is wound with respect to the roll axis to an angle greater than 45 °. Preferably, this? *: Winding angle is between 70 ° and 90 °.

• · • ·

For other advantages and structural details of the invention, reference is made to: the dependent claim of the appended claims.

: 25

The invention will now be described, with reference to a preferred embodiment thereof, with reference to Figure 2 of the patent drawing, which shows a schematic cross-sectional view of a multi-roll calender.

* »* • · • ·: ...: 30 In the multi-roll calender of Figure 2, the flow of the fiberizable fiber web is as follows.

The calenderable fibrous web W enters into the upper nip YN, 5 113792, between the upper roller 1 of the multi-roll calender and the upper rigid jacket: a press roll 2 having a smooth-faced metal or champer jacket 21, from which the fibrous web W to the upper profiling nip PN1 between the intermediate or center roll 4, which is a shoe roll having a composite material jacket 41, whereupon the fibrous web W wraps around the guide member 5 (e.g., guide roll) of the upper central roll 4 of the invention and the shoe roll. to a pivot node KN between a lower intermediate or center roll 6, which is a shoe roll, which also has a composite casing 61, whereupon the fibrous web W rotates about a guide member 7 (e.g. a guide roll) with the lower lower roll 6 according to the invention; a lower stiff-clamping roller 8 with is a smooth surface metal or chill sheath 81 to a lower profiling nip PN2 between 10, after which the fibrous web W rotates the guide member 9 (e.g. around the guide roller) into the lower nip AN between the lower rigid sheath press roll 8 and the calender lower roll 10.

The upper middle or shoe roll 4 according to the invention has a composite diaper 41 and an upper fibrous web upper profile nip PN1, a fibrous web twisting nipple KN and a lower ribbing 43 which overlap and profilate the composite diaper PN1 and the pivot nip KN. The lower middle or shoe roll 6 is substantially identical to the upper shoe roll 4. So in the lower one

the middle or shoe roll 6 according to the invention has a composite diaper 61 and a pivot nipple KN

·, «. 20 and with the profile nip PN2 aligned with the fiber web pivoting nip KN, lower • ·, ·. : upper profile shoe is loaded and profiled by PN2 profiling nip and composite diaper 61. . 62 and the lower shoe row 63.

* '·': In order to provide successive profiling nips that similarly profile and enhance the result of calendering t '25, the rotary nip KN is preceded by at least one profiling nip PN1 (as shown in Fig. 2) facing the upper rigid: a metal or chill sheath 21 and a composite sheath 41 of the upper middle / · 'shoe or shoe roll 4 according to the invention; At least one profiling nip PN2 (as shown in FIG.

• I

30 sa 2) with a composite of a lower middle or shoe roll 6 according to the invention; 1 1 ti sheath 61 and metal or chill sheath 81 of lower rigid sheath press roll 8.

i 1 · »• t 6 113792

According to the invention, the properties of the composite material are selected by fiber orientation such that the composite sheath 41, 61 is substantially stiffer in circumferential direction than in the axial direction, thereby changing the loading of shoe rows 42, 43, 62, 63 by changing the composite sheath 41,61, profiling nip NP1, NP2 and / or the profile can be changed. In this case 5 is possible e.g. nip control of the profiling nip PN1, PN2 and / or pivot nip KN, and correcting profile errors caused by different deflection of the rollers defining the nip by changing the profile of the roll sheath or rolls.

In order to make all calendering nipples profiling and profiling the fibrous web W, in the embodiment according to fig. 101 is made of a composite material, which is preferably the same composite material as the composite material of the diapers of the center rolls 4, 6. When the upper and lower rollers 1, 10 are additionally provided with an inner diaper loading shoe row 12, 103, the profile of the composite diaper 11, 101, the upper nip 15 YN and / or the sub nip AN can be changed by changing the loading of the shoe rows 12, 103. This makes it possible for e.g. nipples YN, PN1, KN, PN2, AN

control, and correcting for a profile error due to differential deflection of the upper and lower rollers defining the nip by changing the profile of the roll shell.

According to a particularly preferred embodiment of the invention, the composite material is. . 20 selected from the group consisting preferably of: continuous fiber reinforced plastic; glass fiber; carbon fibers; tu / epoxy composite.

In order to be more rigid in the circumferential direction than in the axial direction, in a preferred embodiment of the invention, the fiber orientation of the composite material is implemented such that the greater part of the fibers of the mouth T: 25 is wound on the roll 1, 4, 6, 10 relative to the axis at an angle greater than 45 °. Preferably, this winding angle is between 70 ° and 90 °.

• I · • ·

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* The shoe roller 1, 4, 6, 10 according to the invention is preferably a hydraulically zone-adjustable roller, a roller, an intermediate roll, a central roller or a lower roller with a composite jacket 11, 41, 61, 101 supported by ... from the central axis by a hydrostatic loading arrangement 12; 42, 43; 62, 63; 103, such as a row of load-bearing shoes that move a com- ponent rotating about the center axis. for carrying the center axis of the nip force exerted on the positive sheath.

7, 113792

The invention has been described above by way of example only, with reference to a preferred embodiment thereof. Of course, this is not intended to limit the invention and, as will be apparent to one skilled in the art, various alternative solutions and variations are possible within the scope of the inventive idea and the scope defined by the appended claims. Particularly noteworthy is the wide utility of the present invention with the exception of pure machine calendering in almost all kinds of calendering applications.

The composite diaper shoe roll according to the invention enables the calender to be run and operated by various nip combinations. Some of the nipples can be kept open. For example, in the case of Fig. 2, the nips AN and PN2 may be left open, whereby the web W is introduced directly from the nip KN to the winding. In this case, the calender of FIG. 2 can be traced to a double nip by applying pressure on roller 4 only to the shoe 43 and leaving the shoe 42 unpressurized. Thus, a calender is provided which has two successive nips on the same side of the web W profi-15. When at the same time the upper and lower shoes 12 and the nip 43 is pressed or reduced may be accomplished sequentially in the same way, two profiling nip the web W, thus enhancing the final result.

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Claims (8)

Multiple roll calender comprising a plurality of rollers (1,2, 4, 6, 8, 10) defining at least one profiling nip (PN1, KN, PN2) profiling a fiber web (W) calendered, wherein an at least one intermediate roll existing between an Upper roll (1) and a lower roll (10) in the calender is a shoe roll (4, 6) which defines a profiling nip along with another calender roll, said eating at least one shoe roll (4, 6) comprises a stationary center shaft, a sheath (41, 61) rotating around the center shaft and at least one row of loading shoes (42, 43, 62, 63) affecting the inner surface of the sheath, a row 10 being arranged in the direction of said at least one profiling nip (PN1, KN, PN2), characterized in that at least two intermediate rollers are shoe rollers (4, 6), whose sheath (41, 61) is fiber-reinforced composite material, the properties of which have been selected by fiber orientation so that the men are stiffer in perimeter than in axial r and which sheath (41, 61) is movable in calender function with respect to the center shaft to release said two superposed shoe rollers (4, 6) from nip contact (PN1, KN, PN2) with another calender roll (2, 8 ) or another shoe roll (4.6). 2. A calender according to claim 1, characterized in that said at least two intermediate rollers (4, 6) comprise two loading grooves (42, 43, 62, 63), whereby [20 at the shoe lines are arranged at regular intervals with relating to each other in the mantle; / (41.61) perimeter. 3. A calender according to claims 1 or 2, characterized in that the upper roller (1) of the calender is a shoe roller, the sheath of which is fiber-reinforced composite material, whose properties have been selected by fiber orientation so that the men are stiffer in the circumferential direction than in :. axial direction. ... 4. A calender according to any one of claims 1-3, characterized in that the lower roll is a shoe roll, the sheath of which is of fiber-reinforced composite material, whose properties have been selected by means of fiber orientation such that men are stiffer in the circumferential direction than in the axial direction. I I> I · * * 113792 π 5. Calendar according to any of claims 1-4, characterized in that the composite material is reinforced plastic with continuous fibers or composite of epoxy and carbon fiber. 6. A calender according to any one of claims 1-5, characterized in that, in order to achieve the rigid dimension of the shoe roll (1, 4, 6, 10) in the circumferential direction of the shoe roll, the fiber orientation in the composite material has been realized in such manner, that the greater part of the fibers have been wound with respect to the axis of the roller (1.4, 6.10) in a winch that is above 45 °. Calender according to claim 6, characterized in that the winch is advantageously between 70 ° and 90 °. Calender according to any one of claims 1-7, characterized in that the shoe roller (4, 6) is a hydraulically zone adjustable roller. 15 I I • · * I ·: i · * «| »T» I · • »» I * ·>> ·