WO2009077643A1 - Calandre à bande métallique - Google Patents

Calandre à bande métallique Download PDF

Info

Publication number
WO2009077643A1
WO2009077643A1 PCT/FI2008/050566 FI2008050566W WO2009077643A1 WO 2009077643 A1 WO2009077643 A1 WO 2009077643A1 FI 2008050566 W FI2008050566 W FI 2008050566W WO 2009077643 A1 WO2009077643 A1 WO 2009077643A1
Authority
WO
WIPO (PCT)
Prior art keywords
roll
nip
belt
calender
establishing
Prior art date
Application number
PCT/FI2008/050566
Other languages
English (en)
Inventor
Stig Renvall
Original Assignee
Metso Paper, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Metso Paper, Inc. filed Critical Metso Paper, Inc.
Priority to AT0942808A priority Critical patent/AT508202B1/de
Priority to DE112008003333T priority patent/DE112008003333T5/de
Publication of WO2009077643A1 publication Critical patent/WO2009077643A1/fr

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
    • D21G1/00—Calenders; Smoothing apparatus
    • D21G1/006—Calenders; Smoothing apparatus with extended nips
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
    • D21G1/00—Calenders; Smoothing apparatus
    • D21G1/0066—Calenders; Smoothing apparatus using a special calendering belt

Definitions

  • the present invention relates to a metal belt calender, comprising a metal belt adapted to extend around guiding rolls, outside said belt being disposed at least one counter-roll in a way to establish between the belt and the counter-roll a fibrous web treatment zone, the fibrous web to be treated being passed therethrough.
  • Calendering is a process, in which the surface properties and the thickness profile of various grades of paper and board are worked on to match the requirements of a printing method and further processing, such as e.g. a coating process, by compressing the paper between two or more compression elements, whereby the paper, due to mechanical working and heat, undergoes a deformation both in horizontal and vertical directions.
  • Coated grades are typically pre-calendered prior to a coating process and post-calendered after the coating process.
  • Calendering is the final operation in a paper making process, which can be used for making a major difference in the properties of paper.
  • calendering can be often broken down into two operations, pre-calendering prior to and final calendering after the coating process.
  • Paper and board grades are available in a wide variety and can be divided according to basis weight into two categories: papers with a single ply and a basis weight of 25-300 g/m 2 and boards made in multi-ply technique and with a basis weight of 100-600 g/m 2 .
  • the borderline between paper and board is flexible as board grades with lightest basis weights are lighter than the heaviest paper grades.
  • paper is used for printing and board for packaging.
  • the subsequently presented descriptions are examples of currently applied values for fibrous webs, and there may be considerable fluctuations from the disclosed values. The descriptions are mainly based on the source publication Papermaking Science and Technology, section Papermaking Part 3, Finishing, edited by Jokio, M., published by Fapet Oy, Jyvaskyla 1999, 361 pages.
  • Mechanical-pulp based, i.e. wood-containing printing papers include newsprint, uncoated magazine and coated magazine paper.
  • Newsprint is composed either completely of mechanical pulp or may contain some bleached softwood pulp (0-15%) and/or recycled fiber to replace some of the mechanical pulp.
  • General values for newsprint can probably be regarded as follows: basis weight 40-48.8 g/m 2 , ash content (SCAN-P 5:63) 0-20%, PPS SlO roughness (SCAN-P 76-95) 3.0-4.5 ⁇ m, Bendtsen roughness (SCAN-P21:67) 100-200 ml/min, density 600-750 kg/m 3 , brightness (ISO 2470:1999) 57-63% and opacity (ISO 2470:1998) 90-96%.
  • Uncoated magazine paper usually contains mechanical pulp to 50-70%, bleached softwood pulp to 10-25%, and fillers to 15-30%.
  • Typical values for calendered SC paper include basis weight 40-60 g/m 2 , ash content (SCAN-P 5:63) 0-35%, Hunter gloss (ISO/DIS 8254/1) ⁇ 20-50%, PPS SlO roughness (SCAN-P 76:95) 1.0-2.5 ⁇ m, density 700-1250 kg/m 3 , brightness (ISO 2470:1999) 62-70% ja opacity (ISO 2470:1998) 90-95%.
  • HWC can be coated even more than twice.
  • Chemical-pulp produced, woodfree printing papers or fine papers include uncoated - and coated - chemical-pulp based printing papers, in which the portion of mechanical pulp is less than 10%.
  • Uncoated chemical-pulp based printing papers contain bleached birchwood pulp to 55-80%, bleached softwood pulp to 0-30%, and fillers to 10-30%.
  • the values with WFU vary widely: basis weight 50-90 g/m 2 (up to 240 g/m 2 ), Bendtsen roughness 250-400 ml/min, brightness 86-92%, and opacity 83-98%.
  • coated chemical-pulp based printing papers WFC
  • the amounts of coating vary widely according to requirements and intended application.
  • Release papers have a basis weight within the range of 25-150 g/m 2 .
  • Other papers include, among others, sackkraft papers, tissues, and wallpaper bases.
  • Board grades make up a reasonably heterogeneous group, comprising high basis weight grades, the basis weight of which can be as high as 600 g/m 2 , and low basis weight grades, the basis weight of which is about 120 g/m 2 , the grades possibly ranging from one based on primary fiber to one based by up to 100% on recycled pulp and from an uncoated grade to those with multiple coats.
  • the board grades will be subsequently divided into coated and uncoated ones, because the coating has a major effect on the calendering process.
  • the coated grades involve the use of both pre- calendering upstream of a coating device and a final calender downstream of the coating device.
  • the uncoated grades are only subjected to final calendering.
  • Uncoated board -based on primary fiber (kraft liner, white top liner, liquid packaging board) -based on recycled fiber (test liner)
  • Calenders are broken down into machine calenders, soft calenders, and multi-roll calenders.
  • the machine calender has typically 1-2 nips and both rolls of the nip are hard rolls.
  • the soft calender has generally 1-4 nips and at least one of the rolls making up a nip is coated with a soft coating.
  • the multi-roll calender has usually 5-11 nips.
  • the array of rolls in a multi-roll calender comprises both heated rolls and soft surface rolls.
  • Special calenders include, among others, a wet stack calender, a breaker stack, and long-nip calenders.
  • the wet stack calender is roughly identical to the multi-roll calender, but the calendering process is totally different.
  • the wet stack calender makes efficient use of a moisture gradient, the moisture of a web arriving at the calender being only about 1-2%.
  • the wet stack calender has water boxes for forming a water film on the web surface upstream of the nip, said film being pressed to the web surface in the nip. Accordingly, the web only becomes moist on the surface, thus calendering more at the surface than in the overdried interior.
  • the wet stack calender is used as a pre-calender prior to a coating process for many board grades, such as e.g. solid bleached board (SBS).
  • SBS solid bleached board
  • the intermediate calender is a machine calender, which is located in the dryer section of a paper machine.
  • the long-nip calenders include a shoe calender, which has a soft shell around the shoe roll and which has a nip length typically of 50-400 mm, as well as belt calenders.
  • the traditional belt calender consists of a soft calender's thermo roll, belt circle, and a counter-roll inside the belt circle which can be a hard or soft roll. The belt runs around by way of the counter- roll and guide/tension rolls.
  • a special application of the belt calender is a metal belt calender, in which the calendering belt comprises a metal belt which extends around guide rolls and, together with a counter-element, which is typically a roll, establishes a long nip zone whose length can be even more than 5000 mm. Inside the belt circle can be further provided a press element, e.g. a deflection-compensated roll, which enables a higher compression pressure nip point to be provided in the middle of the long nip.
  • a press element e.g. a deflection-compensated roll
  • European folding board is typically manufactured by using a Yankee cylinder, which provides smoothness on the top surface of a sheet.
  • the web must be delivered into and out of a Yankee cylinder at a certain web surface moisture for optimal final smoothness and runnability. This implies that a fixed diameter of the dryer imposes a limit on the range of speed at which the web can be run around a Yankee cylinder.
  • the range of basis weight, which can be efficiently run on the machine, is quite narrow, and modern high machine speeds would require unrealistically large diameters for Yankee cylinders.
  • Hard-nip calenders are used in new coated board machines for smoothing the web prior to coating without compromising efficiency and with a maximal output capacity.
  • a sustainable smoothness cannot be achieved to the extent of what is accomplished by wet stack calenders or a Yankee cylinder.
  • a higher roll temperature provides better smoothness with lower nip loads, and bulk as well as stiffness can be spared.
  • a high roll temperature softens fibers of the actual surface, giving considerable smoothness to the basic sheet.
  • the water originating from coating penetrates deeper into the sheet, resulting in the swelling of fibers and renewed roughening of the basic sheet's surface.
  • a smoothening effect continuing throughout the coating process is achieved, provided that the web is surface-moistened prior to the treatment in a hot nip.
  • a steam generator can be used for this purpose, but that functions by condensing the vapor for a film of water on the surface of a low-temperature web and calls for cooling of the web.
  • a more effective tool is to employ an air-atomized micro-drop moistening device. Positioning the unit is critical as the dwell time has an effect on the water penetration depth in the web. A more permanent smoothening result is obtained by having a long dwell time and a large amount of water.
  • a hard nip as established either between two rollers or by using a metal belt, provides a good large-scale smoothness, whereas a soft nip provides a good small-scale smoothness.
  • the softest nip is obtained by means of an OptiDwell shoe calender, in which the reduction of bulk, as well as stiffness, is highly marginal. What can be anticipated in addition to a small-scale smoothness is a highly uniform absorption of the coating agent, as well as absorption during the printing period, and the result is a printed product without gloss mottles.
  • a viable option to the shoe calender is soft calendering, which is implemented by using roll coatings of a relatively soft material.
  • a moistening device hot soft-nip and hard-nip technologies provides a large-scale smoothness which competes with wet stack and Yankee cylinders while resulting in a better small-scale smoothness with 4-7% higher bulk and density.
  • a metal belt calender has been found to provide paper and board with desired properties which have been earlier obtained by said calender technologies, with the exception of a small-scale smoothness. Paper and board webs, which are difficult to calender, such as board webs made from North American softwood species, do not create a sufficient small-scale smoothness in a metal belt calender.
  • a metal belt calender according to the invention is characterized in that the calender comprises a first nip roll, disposed outside the belt, establishing a soft nip with the counter-roll and set in a location upstream of the treatment zone in the running direction of a web, said nip roll applying a compression effect on one side of the fibrous web; a second nip roll, disposed likewise outside the belt, establishing a soft nip with the belt circle guiding roll and set in a location downstream of the treatment zone in the running direction of the web, said nip roll applying a compression effect on the other, opposite side of the fibrous web; and a third hard-surface nip roll, which is disposed in an intermediate location between said
  • the apparatus according to the invention expands an application range for the successful use of metal belt technology. In some cases, moistening may be needed for softening the fibrous web upstream of the apparatus for improving the smoothness result even further.
  • the apparatus of the invention combines the attainment of a good small-scale smoothness offered by a soft nip with a large-scale smoothness obtainable by means of a hard nip on both sides of a web. It is prior known that a soft nip produces a good small-scale smoothness (PPS slO roughness (SCAN-P 76-95)), but does not a major effect on large-scale smoothness (Bendtsen roughness (SCAN-
  • a hard nip or a metal belt calender produces a reverse outcome, i.e. a good large-scale smoothness, but the small-scale smoothness falls short of what is obtained by a soft nip.
  • the metal belt calender according to the invention lends itself particularly well to board making, which is currently practiced by using wet stack calenders or Yankee cylinders.
  • the solution according to the invention enables improving stiffness by about 5% with respect to the prior art methods, while the other board properties remain the same or become better.
  • the wet stack calender offers a good smoothness prior to coating and an adequate absorption resistance for the coating.
  • the web undergoes a substantial compaction with a reduction of bulk and stiffness.
  • web breaks are commonplace in wet stack calenders. The machine's production capacity suffers, because the web must be subjected to drying upstream of the set of rolls, and the added water must also be drained.
  • the metal belt calender comprises a metal belt 3, which is adapted to extend around heated belt guiding rolls 2 and which establishes a long calendering zone PN with a counter-roll 8 disposed outside the belt circle.
  • the counter-roll 8 is preferably a heated roll.
  • a fibrous web W is adapted to travel through said long nip.
  • the nip roll 5b is set in register with the heated guide roll 2 inside the belt circle, establishing a soft nip therewith.
  • the fibrous web W is guided by means of a deflection roll 7 away from the latter soft nip.
  • the apparatus of fig. 1 further comprises a hard-surface nip roll 4 inside the belt circle 3 for establishing a hard nip at an intermediate location between said soft nips 5a, 8 and 5b, 2 in the calendering zone PN.
  • a hard-nip establishing nip roll can also conceivably be placed outside the belt circle, in which case it can be positioned against e.g. the same guide roll 2 as the latter soft-nip establishing nip roll 5b, upstream of said nip roll 5b as regarded in the web running direction.
  • the solution according to the invention is capable of providing both a good large-scale and small-scale bilateral smoothness for a fibrous web.
  • the metal belt 3 has its temperature preferably adapted to be substantially equal to that of its counter-roll 8, whereby the roll 8 and the belt 3 can be heated or cooled.

Landscapes

  • Paper (AREA)

Abstract

L'invention porte sur une calandre à bande métallique (1), comprenant une bande métallique (3) apte à s'étendre autour de rouleaux de guidage (2). À l'extérieur de la bande est disposé au moins un contre-rouleau (8) de façon à établir entre la bande (3) et le contre-rouleau (8) une zone de traitement de nappe fibreuse (PN), la nappe fibreuse à traiter étant amenée à passer à travers celle-ci. La calandre comprend un premier rouleau de pincement (5a), disposé à l'extérieur de la courroie (3), établissant un pincement doux avec le contre-rouleau (8), et situé en un emplacement en amont de la zone de traitement (PN) dans la direction de déplacement d'une nappe (W). Le rouleau de pincement (5a) applique une action de pressage à un côté de la nappe fibreuse. À l'extérieur de la bande (3) est encore disposé un deuxième rouleau de pincement (5), situé dans un emplacement en aval de la zone de traitement (PN) dans la direction de déplacement de la nappe (W) de façon à établir un pincement doux avec le rouleau de guidage de cercle de bande (2), ledit rouleau de pincement appliquant une action de pressage sur l'autre côté opposée de la nappe fibreuse (W). Dans un emplacement intermédiaire entre lesdits premier (5a) et deuxième (5b) rouleaux de pincement établissant un pincement doux est disposé un troisième rouleau de pincement à surface dure (4), qui établit un pincement dur avec le contre-rouleau (8) ou avec le rouleau de guidage de bande (2).
PCT/FI2008/050566 2007-12-17 2008-10-09 Calandre à bande métallique WO2009077643A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AT0942808A AT508202B1 (de) 2007-12-17 2008-10-09 Metallriemenkalander
DE112008003333T DE112008003333T5 (de) 2007-12-17 2008-10-09 Metallriemenkalander

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20075919A FI20075919L (fi) 2007-12-17 2007-12-17 Metallihihnakalanteri
FI20075919 2007-12-17

Publications (1)

Publication Number Publication Date
WO2009077643A1 true WO2009077643A1 (fr) 2009-06-25

Family

ID=38951614

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2008/050566 WO2009077643A1 (fr) 2007-12-17 2008-10-09 Calandre à bande métallique

Country Status (4)

Country Link
AT (1) AT508202B1 (fr)
DE (1) DE112008003333T5 (fr)
FI (1) FI20075919L (fr)
WO (1) WO2009077643A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009028857A1 (de) 2009-08-25 2011-03-03 Voith Patent Gmbh Kalander
EP2492394A1 (fr) 2011-02-25 2012-08-29 Voith Patent GmbH Calendre
WO2013186135A1 (fr) * 2012-06-11 2013-12-19 Voith Patent Gmbh Calandre
DE102015200380A1 (de) 2015-01-14 2016-07-14 Voith Patent Gmbh Band für eine Glättvorrichtung, Glättvorrichtung und Verfahren zur Glättung

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050251976A1 (en) * 2002-01-29 2005-11-17 Juha Lipponen Processing device and method of operating the device for processing a coated or uncoated fibrous web
FI117446B (fi) * 2004-02-13 2006-10-13 Metso Paper Inc Menetelmä ja sovitelma kalanteroidun paperin tai kartongin valmistamiseksi sekä menetelmä saumauksen tekemiseksi monitelahihnakalanterilla

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BRPI0307269B1 (pt) 2002-01-29 2015-09-29 Metso Paper Inc "dispositivo de calandra para calandra uma textura fibrosa revestida e método para calandrar uma textura fribosa revestida ou não revestida com um dispositivo calandra"
DE102005005788A1 (de) * 2004-02-13 2005-09-01 Metso Paper, Inc. Verfahren und Vorrichtung zur Herstellung von kalandriertem Papier oder Karton

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050251976A1 (en) * 2002-01-29 2005-11-17 Juha Lipponen Processing device and method of operating the device for processing a coated or uncoated fibrous web
FI117446B (fi) * 2004-02-13 2006-10-13 Metso Paper Inc Menetelmä ja sovitelma kalanteroidun paperin tai kartongin valmistamiseksi sekä menetelmä saumauksen tekemiseksi monitelahihnakalanterilla

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009028857A1 (de) 2009-08-25 2011-03-03 Voith Patent Gmbh Kalander
EP2295632A1 (fr) 2009-08-25 2011-03-16 Voith Patent GmbH Calendre
EP2492394A1 (fr) 2011-02-25 2012-08-29 Voith Patent GmbH Calendre
DE102011004730A1 (de) 2011-02-25 2012-08-30 Voith Patent Gmbh Kalander
WO2013186135A1 (fr) * 2012-06-11 2013-12-19 Voith Patent Gmbh Calandre
DE102015200380A1 (de) 2015-01-14 2016-07-14 Voith Patent Gmbh Band für eine Glättvorrichtung, Glättvorrichtung und Verfahren zur Glättung

Also Published As

Publication number Publication date
FI20075919L (fi) 2009-06-18
AT508202B1 (de) 2012-01-15
DE112008003333T5 (de) 2010-11-04
AT508202A2 (de) 2010-11-15
FI20075919A0 (fi) 2007-12-17
AT508202A3 (de) 2011-10-15

Similar Documents

Publication Publication Date Title
KR101020163B1 (ko) 처리장치와 코팅 또는 미코팅 섬유웨브를 처리하기 위한 장치를 작동하는 방법
CN100371529C (zh) 用于处理涂布的或未涂布的纤维纸幅的处理设备
US9322135B2 (en) Method for producing fiber webs and production line for producing fiber webs
US20060060322A1 (en) Processing device for processing a coated or uncoated fibrous web
US6869505B2 (en) Method for calendering a board web
EP1238155A1 (fr) Procede et dispositif permettant de produire du papier ou du carton calandre
WO2009077643A1 (fr) Calandre à bande métallique
US6758135B2 (en) Method and device for moisturization of a paper or board web in calendering
EP3012371A1 (fr) Procédé de traitement d'une bande de matière fibreuse et calandre de pour traiter une bande de matière fibreuse
US7943010B2 (en) Method of making surface-sized paper/board
EP2725136A1 (fr) Procédé et chaîne de production et production de toiles de fibre
EP1208266B1 (fr) Procede et dispositif destines au traitement de surface d'une bande de papier et/ou d'une bande de carton
US6886454B1 (en) Calendering arrangement for a paper machine
WO2009147285A1 (fr) Procede de manipulation d’une bande fibreuse dans une calandre a courroie metallique et dispositif permettant la mise en œuvre de ce procede
WO2005031064A1 (fr) Procede pour reguler les caracteristiques structurelles et fonctionnelles d'une bande de matiere fibreuse dans un dispositif de traitement pour bande de matiere fibreuse
WO2004097109A1 (fr) Appareil et procede de fabrication de papier ou de carton et papier ou carton ainsi fabrique
EP2682521A1 (fr) Procédé et dispositif pour le traitement d'une feuille fibreuse
WO2012059635A2 (fr) Procédé et appareil de collage en surface de bande fibreuse

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08862947

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 1120080033331

Country of ref document: DE

ENP Entry into the national phase

Ref document number: 94282008

Country of ref document: AT

Kind code of ref document: A

RET De translation (de og part 6b)

Ref document number: 112008003333

Country of ref document: DE

Date of ref document: 20101104

Kind code of ref document: P

122 Ep: pct application non-entry in european phase

Ref document number: 08862947

Country of ref document: EP

Kind code of ref document: A1