FI117832B - Paper mill glazing assembly has glazing station drums with hard gap and soft gap - Google Patents

Abstract

A paper mill has a multi-stage glazing station (100) for a paper or carton web (W). The glazing station has two or more drums (10, 20). The first glazing station The first glazing station has two separate and glazing gaps (N11, N13). One gap is a hard gap and the other is a soft gap. To achieve a glossy finish the web is glazed by passage thru the first and second stations (10, 20). To achieve a matt finish the web is glazed in one station and circumvents the second. Also claimed is a commensurate process.

Description

117832

Method in multi-roll calender and multi-roll calender

The present invention relates to paper and board machines, more particularly to calenders. More particularly, the present invention relates to a method according to the preamble of claim 1 in a multi-roll calender and to a multi-roll calender according to the preamble of claim 7.

Calendering generally aims to improve the properties such as smoothness and glossiness of a web material such as a paper or board web. In calendering, the web is guided to a nip formed between rolls to be pressed against each other, i.e. a calendering nip, in which the web is deformed by the action of temperature, humidity and nip pressure. In the calender, the nipples are formed between a smooth-faced press roll, such as a metal roll, and a roll coated with a flexible coating, such as a polymer-15 roll. The flexible surface roll conforms to the surface contours of the web and presses the web evenly against the smooth opposing surface of press rolls. In this context, calender rolls mean rolls forming the calendering nip, top roll means the top roll of the roll stack, top nipple means the top calendering nip formed between the top roll and the calender roll below the top roll, lower roll · * · «! 20 denotes the lowest roll of the roll stack and the lower nip means the lowest fish • * · * [sharpening nipple of the roll stack formed by the color of the lower roll and the calender roll above the lower roll. , line. Intermediate nipples mean the calendering nips formed between the upper nip of the calender and the nip by the calender rolls j «« * '*. *.

In the prior art reference is made to U. S. Patent No. 96334, which discloses a method for calendering paper or similar web material in a calender. Me- φ · · • · ». ···. in the system, the web material to be calendered is passed through nips formed by a deflection compensated upper roller and a deflection compensated lower roller and between the upper and lower rollers. The rolls are substantially sequenced into a vertical roll stack. Intermediate rolls are rolls of which the natural deflection line of • · ·:. * Own weight is substantially the same.

* · · 'V

• · | · 2 117832 Mannish. The nip pile load caused by the masses of the intermediate rollers and associated auxiliaries is substantially alleviated in the method and the adjustable load is applied to the calendering tin pins by deflection compensated external or upper / lower torsional load.

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Typically, compression is accomplished in a multi-roll calender by securing the top or bottom roll of the roll stack and squeezing the stack of rolls against a fixed roll which may be a top roll, a lower roll, or one of some of the spacers. Alternatively, both the upper and lower rollers are pressed against each other 10 either so that none of the intermediate rolls are locked in place or at least one of the intermediate rolls is locked in place. The deflections of the rolls can generally be compensated by deflection compensating devices on the upper and lower rolls, for example, so that the calendering nipples take a linear shape.

15 Calendering technology is increasingly switching to on-line calendering as the speeds required by paper machines increase. Multi-nip on-line calendering is calendering in a calender unit in which the nips are alternately formed between successive smooth-faced press rolls, such as a metal roll, and a roll coated with a flexible coating, such as a polymer roll. Line load-20 increases in multi-nip calendars from top nip to bottom nip due to • l | * '] of power if roller relief systems are not used. Downwardly rising viii. . to eliminate traction, control roll deflection, and also for quick release of the roller, the current multi-nip calendars use cylindrical and • t · * * · '' 'lever pull mechanism to compensate for the ground's pulling force. the roller lightening system is used in the multi roller calendars known by the applicant's trademarks ^ OptiLoad and TwinLine.

BACKGROUND OF THE INVENTION Multi-roll calenders are known in the art, having a set of two rolls, each having at least two fish rolls.

As the speed of paper machines increases and the need for online calendering grows, the calender also requires the ability to perform various types of calendering with the calender, which can be accomplished by, for example, known nipple driving. take the position where the paper web is passed through the calender so that during calendering only a portion of the possible nipples of the calender are calendered.

Various soft calenders are known in the art, which generally calender a web in two successive nipples. Each nip consists, for example, of a matte-coated thermo-roller with a soft polymer-coated roll. Two-nip soft calenders in which all rolls are polymer-coated are also known.

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It is also known in the art to have a separate soft nip in connection with the multi-roll calender, in which both rolls are polymer-coated.

It is also known in the multi-roll calender to replace the lowest thermal roll, e.g., 15, with a polymer roll in place of the calender roll above the lower roll, and to drive the paper only from the polymer roll rolls. In addition, there is known a multi-roll calender such as the one described above, in which a polymer roll is replaced in place of the lowest thermal roll and in which a roll is locked to a fixed rotatable position. Hereby, a lockable roller can be arranged to open some of the nipples and pass the web through only 20 soft polymer roller nipples.

* · »• * · * / The so-called all-on-line paper and cardboard coatings known in the art are ♦ · · ***. ' toner machine lines using a variety of calendering concepts that allow calendering of both shiny and matte species. The soft and multi-roller * · • · 25 lantern calender concept is expensive due to different roll types and also requires more machine-directional hall space than, for example, multi-rollers. mangle. Only calender concepts based on soft calendars, which can also ♦ · list the production of high-gloss fiber webs, are even more expensive and also require more machine-directional hall space than the concept described above.

30 ** ·•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 177852

One drawback in prior art overlay all-on-line fiber web line calender concepts is that the calender roller may become soiled due to coating failures, requiring the calendering to be interrupted during roller cleaning, thereby reducing the production cost of the entire fiber web.

One disadvantage of the known solutions is that in some cases the multi-roll calendars are driven with line loads that cause a very small load, even so-called, on the roller bearings of the calender roll. zero load. This is very problematic for the roller bearings because, in a zero-load condition, the rolling elements of the rolling bearings are substantially slidable relative to the bearings instead of rolling, resulting in a rather rapid breakage of the bearing. Advantageously, in the case of a zero bearing load of a rolling bearing, the point of contact between the rolling bearing rolling elements and the bearing surfaces is indefinite and variable because the rolling elements are not regularly compressed by the rolling elements in any direction with sufficient force.

It is an object of the present invention to prevent the above-mentioned problems and disadvantages, or at least to reduce the above-mentioned drawbacks.

*: 1 ·: 20 • · ·! It is an object of the invention to provide a method and a multi-roll calender for producing a glossy and matte fiber web.

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• 1 m • · · ··· ·

The object of the present invention is to eliminate the above-mentioned problems and drawbacks, or at least to reduce the above-mentioned drawbacks.

* 1 ·

In order to achieve the objects set forth above and hereinafter, the method of the invention is essentially characterized by what is stated in the characterizing part of claim 1.

♦ 1 · 30 ♦ · 1 • · • · ♦ · • ♦ · · · 5 117832

The multi-roll calender according to the invention, in turn, is essentially characterized by what is stated in the characterizing part of claim 7.

In the method according to the invention, which according to a preferred embodiment is applied in a multi-roll calender comprising at least two rolls and wherein the first roll preferably comprises two deflection-compensated rolls and two thermo rolls arranged so as to form two separate hard / soft nips the web is calendered on both sides, and wherein the second roll preferably comprises at least three rolls with the intermediate roll (s) being / are twin nip rolls, and the web is calendered on both sides. In applying the method of the invention, calendering of the shiny nonwoven webs is accomplished by using at least the first and second rolls simultaneously. During the possible cleaning of the roll surfaces or during roll replacement, the method according to the invention makes it possible to bypass the rollers so that at least one roller is used for calendering matte grades.

In accordance with the invention, preferably for single nip driving of the first roller, the thermal rollers are placed on deflection compensated rolls, whereby the roll diameter is not increased and the weight of the thermal roller can be utilized in the nip load.

·: ··: 20 · »» V · The calendering nip formed by the deflection compensated roller and the thermal roller is • 1 according to an advantageous additional feature positioned at an angle to the vertical, • · «1» · ' Preferably, in accordance with the invention, the deflection-compensated rolls and thermo-rolls are firmly supported on the body, and the opening and closing of the calendering nip takes place by means of a diaphragm load. with a deflection compensated roll.

The method and the multi-roll calender according to the invention can be modified later, by making the calender a two-roll calender with a mo | each half is calendered separately on the different tracks. In this case, the deflection roll of the first roller is attached to the top of the calender body and the top deflection of the second roller is likewise secured to the top of the calender body. In this connection, also the second rolls are provided with mating surfaces for hanging the thermo roll and the polymer roll in a manner known per se to a person skilled in the art. In addition, one polymer roll from the second roll is transferred to the first roll, whereby each roll receives the same number of rolls with the existing roll scope (the number of rolls delivered in the first step, which does not therefore need to be added at the change).

The invention provides significant advantages over prior art solutions, and among these benefits, the following may be mentioned. By means of the invention, the efficiency of the fiber web machine line is increased, because during coating interruptions or roll changes, a calendered matte web can be produced on both sides bypassing the first or second roller. Glossy webs are made using both rollers. Due to the advantageous roll arrangement of the first roller according to the invention, it is possible to utilize rolls dimensioned for double nip run of the second roller in a single nip drive and achieve the desired single load of 100 kN / m line load. (One-sided line loading, in other words, single-nip driving requires a larger diameter than a roll designed for double nip driving. In single-nip * 1 · · '20 speed driving, the nip opposite support is missing, requiring the roll to be stiffer • «· **], thus requiring a larger diameter • 1.. More costs.) The investment cost of the calender according to the invention I 1 t • · ♦ "V is significantly lower than the prior art calender cones due to the smaller number of spare rolls and smaller roll diameters. smaller diameter rollers for double nip drive and less spare rolls due to the fact that only • · · ^ * 1 1, ···. single roll diameters are used.

• e • 1 · «« t • · · • 1 • · • · · · · ♦ ·································································. · '117832

The invention will now be described with reference to the accompanying principal figure, which illustrates the method and the multi-roll calender according to the invention, without, however, limiting the invention to that shown in the figure.

The figure schematically shows an embodiment of a calender according to the invention.

The figure schematically illustrates a multi-roll calender 100 having two rollers 10, 20. In a multi-roll calender, the fiber web to be calendered is designated by the reference numeral 10 W. In the figures, the body of the multi-roll calender is designated 30.

The first roll 10 has two deflection compensated rolls 12, 14 and two thermo rolls 11, 13 which are arranged to form two separate hard / soft nipples Nil, N13 in which the web W is calendered on both sides.

The calendering nip Nil, N13 formed by the deflection compensated roll 12, 14 and the thermal roller 11, 13 is disposed at an angle α with respect to the vertical, in order to avoid zero loading of the rolling roller bearing of the thermal roller 11, 13. The angle α is from 5 ° to 30 °, preferably from 10 ° to 25 °.

· * ·· # · • · • · · · · '. 20 The second track 20 has a top roll 21 and a bottom roll 26, and four between the top roll and the bottom roll • · * · · * ·. . a tracked intermediate roll 22, 23, 24 and 25, wherein the upper, lower and intermediate rolls form • · · • * · | * V a continuous second roll 20 comprising calender rolls 21-26. The intermediate rolls are • * · dual nip rolls, forming a calendering nip with both the top and bottom rollers. In the embodiment shown in the figure, upper roll 21 and lower roll 26; 25 are deflection compensated rolls. The upper and lower rollers 22, 25 of the intermediate rolls are • • *. ·· ♦. the rolls and the middle intermediate rolls 23, 24 are polymer rolls. In the second track 20 • · · *. the web W is calendered on both sides. In the other track, adjacent tiles ·····. 1 • · hub rolls 11.12; 12.13; 13.14; 14,15 and 15,16 form the calender roll pairs, * · "* in which the calender rolls may in each case form a fiber web for calendering * · * * * ·” 30 nip N1, N2, N3, N4 and N5. ** ·· * the second set of tracks 20 is illustrated using an example of a six-roll and five-nip 8 117832 tracks, but another number of tracks and nips on the track may equally well be provided that the other track has at least three rolls.

In applying the method of the invention, calendering of the shiny nonwoven webs is accomplished by using the first and second rollers 10, 20 simultaneously and the passage of the web W is depicted in the figure by a solid line. The method according to the invention enables rollers 10; 20 passes so that only one Telas-to-10; 20 is used to calibrate matte grades. The passage of the web W in the situation where the first roller 10 is bypassed is indicated in the figure by the dashed line 10 W1. The passage of the web to pass the second track 20 is shown in the figure by the dashed line W2.

As shown in the figure, the thermo rolls 11,13 of the first set of rollers 10 are disposed on the deflection compensated rolls 12, 14, which allows the first set of set of rollers 10 to be used in single-nip operation as well. In this case, too, the roll diameter does not grow large and the weight of the thermal roll can be utilized in a nip load.

The multi-roll calender shown in the figure is a further feature of the invention. The calender can later be changed to make the calender a dual roll • · ... 20 calender, where both sides of the web are calendered separately in the rollers.

• · 1 2 3 • · · *. In this case, the deflection compensated roll of the first roller is attached to the calender ····· '* ·. . the upper body and the upper deflection of the second roller are likewise secured to the upper part of the body of the calender. The second roller is also provided with mounting surfaces for the thermal roller and polymer roll in a manner known per se to the skilled roller. the first track so that each track has the same number of rolls.

The invention has been described above by way of example with reference to the figures in the accompanying drawings. However, the invention is not limited to the description and description.

9 117832, but different embodiments of the invention may vary within the scope of the inventive idea defined in the appended claims.

• · 1 2 3 · · * · * 1 · *** ··· • · · * ·>. ' • · * · • · t • 1 1 * ··· • 1 «• 1 1 • · 1 •« · • * * * * 1 * ··.

• 1 * · • · · * • »• 1 · ♦ t * · · * 1 • · • · * * · · * · · ♦« • · 2 * 1 «3 • ·

Claims (12)

117832 ίο [ A method in a multi-roll calender wherein the fiber web, in particular paper or board web (W) is calendered in a multi-roll calender 5 (100) comprising at least two rolls (10, 20), characterized in that the fiber web (W) is calendered in the multi-roll , the first roll (10) comprising two separate hard / soft fishtering nipples (N11, N13), i.e. two separate calendering units which are separate from one another so that the calendering units are not in nip contact with each other, in a second roller (10, 20) and that in order to calender the matte-coated fiber web types, the fiber web is calendered in at least one roller (10; 20) and at least one roller (20; 10) is bypassed. 15 Method according to Claim 1, characterized in that both sides of the fiber web (W) are calendered in the first roll (10) of the multi-roll calender in two separate thermo rolls (11, 13) * ···· *> # 1 2 3 12, 14) in the calendering nipple ♦ 1 · vi 20 (Nil, N13). ·· 1 ·· • · • e ··· ··· '' ·· • · · ·. "1.1 Method according to claim 1 or 2, characterized in that the method t1 '# in the second roller (20) of the multi-roll calender calenders the fiber. ♦ «· both sides of turain (W) in at least two calendering nips which. ·. 25 is formed between at least one twin nip roll and a second roll. • · • · ♦ ♦ A method according to any one of claims 1 to 3, characterized in that the fiber web (W) is calendered in the second 2 • · • roller of the multi-roll calender with at least five calendering nips (N1-N5) formed by at least four double nip rolls (22, 23, 24) and a roll of compensated roll disposed on the upper roller (25) and lower roller (26) of the blade (20). Method according to one of Claims 1 to 4, characterized in that in the method 5, the fibrous web (W) is calendered in a calendering nip (Nil, N13) formed by a deflection compensated roll (12, 14) and a thermal roll (11, 13) of the first roll (10). at an angle (a) to the vertical. Method according to one of Claims 1 to 5, characterized in that during the cleaning and / or replacement of the second roll, the fiber web is calendered only in one roll (10; 20) and the other roll (20; 10) is bypassed. Multi-roll calender for calendering a fibrous web (W) comprising at least two rolls (10, 20), characterized in that the first roll (10) of the multi-roll calender (100) comprises two separate hard / soft calendering nips (Nil, N13) a separate calendering unit which is separate from one another so that the calendering units • · * * · '] are not in nip contact with each other. The multi-roll calender according to claim 7, characterized in that • * · ·· *. ··! the first roll (10) of the multi-roll calender (100) comprises two separate ···. · ···. ' calender nips (Nil, N13) between the thermal roll (11, 13) and the deflection compensated roll (12, 14). The multi-roll calender according to claim 7 or 8, characterized in that one of the rolls (20) of the multi-roll calendar comprises at least three rolls (21-# ·). 26. and that at least one intermediate roll (22-25) is a twin-nip roll. •: 30 * · · · ♦ · · ·: 12 117832 Multi-roll calender according to one of Claims 7 to 9, characterized in that the second roll (20) of the roll roll calender comprises at least five calendering nips (N1-N5) formed by at least four double nip rolls (22, 23, 24) and a roll ( 20) via a deflection compensated roll located in the upper roll (25) and the lower roll (26). Multi-roll calender according to one of Claims 7 to 10, characterized in that the calendering nipples (N11, N13) of the first roller (10) of the multi-roll calender are located at an angle (a) with the vertical plane. 10 Multi-roll calender according to one of Claims 7 to 11, characterized in that, in the calendering nip of the first roll (10) of the multi-roll calender, the thermal roll (11, 13) is disposed on a deflection compensated roll (12, 14). 15 • »♦ 1 2 3 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · each · each · to · to · * ···. '• · · · · * * · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · room Bg • · · · • · · '• · ♦ · ♦ ·· · • · 2 • · φ · · * · • ♦ 3 117832 π Patenlkrav