WO1987005954A1 - Procede de traitement de cellulose de bois - Google Patents

Procede de traitement de cellulose de bois Download PDF

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Publication number
WO1987005954A1
WO1987005954A1 PCT/SE1987/000124 SE8700124W WO8705954A1 WO 1987005954 A1 WO1987005954 A1 WO 1987005954A1 SE 8700124 W SE8700124 W SE 8700124W WO 8705954 A1 WO8705954 A1 WO 8705954A1
Authority
WO
WIPO (PCT)
Prior art keywords
fraction
reject
pulp
reject fraction
steam
Prior art date
Application number
PCT/SE1987/000124
Other languages
English (en)
Inventor
K. Ove Danielsson
Bo G. S. Falk
Original Assignee
Sunds Defibrator Aktiebolag
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 Sunds Defibrator Aktiebolag filed Critical Sunds Defibrator Aktiebolag
Publication of WO1987005954A1 publication Critical patent/WO1987005954A1/fr
Priority to NO875001A priority Critical patent/NO875001L/no

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
    • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/02—Pretreatment of the raw materials by chemical or physical means
    • D21B1/021—Pretreatment of the raw materials by chemical or physical means by chemical means
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
    • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
    • D21B1/14—Disintegrating in mills
    • D21B1/16—Disintegrating in mills in the presence of chemical agents
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/001—Modification of pulp properties
    • D21C9/002—Modification of pulp properties by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives
    • D21C9/004—Modification of pulp properties by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives inorganic compounds

Definitions

  • This invention relates to a method of processing mechanical pulp intended for the manufacture of printing paper.
  • the mechanical pulp consists of groundwood pulp or thermomechanical pulp (TMP).
  • Groundwood pulp is manufactured by pressing wood material against a rotating grindstone or grinding disc for exposing the fibres. Owing to the grinding treatment the resulting groundwood contains a relatively great proportion of fibres not entirely defibrated, of shives and more or less torn and cut-off fibres and of fines.
  • the advantages of the groundwood are, besides high wood yield, relatively low energy consumption at the manufacture and high light scattering.
  • the short mean fibre length of the groundwood and the high content of fines bring about a smooth surface and a high opacity of the paper made of the groundwood.
  • the shives content, however, and the relatively low strength of the groundwood constitute a serious disadvantage.
  • Tnermomechanical pulp is manufactured by preheating wood chips and refining between two opposite refining discs.
  • the resulting pulp contains a relatively low proportion of not defibrated fibres and shives, a high proportion of whole fibres and, compared with groundwood, a low proportion of fines.
  • the thermomechanical pulp has a higher strength than groundwood, but a lower light scattering.
  • the disadvantage of this pulp, especially at the manufacture of printing paper finer than newsprint, such as uncoated paper for rotogravure and coated light-weight papers (LWC) is the high stiffness of the long fibre fraction and the poor flexibility of these fibres.
  • the present invention relates to a method of processing groundwood and thermomechanical pulp in such a manner, that the aforesaid disadvantages of the high shives content of the groundwood and the stiff fibres of the thermomechanical pulp are reduced to such a degree, that an uppgraded mechanical pulp is obtained, i.e. a pulp of higher quality and, consequently, greater usefulness.
  • the system according to the embodiment shown comprises a screen 1, which also can consist of a combination of several screens and vortex cleaner.
  • An accept conduit 2 and a reject conduit 3 extend from said screen 1.
  • the reject conduit 3 leads to a dewatering device 4, preferably in the form of a press, and a subsequent mixing device in combination with a compressing screw feeder 5, which also comprises means for a certain mechanical processing of the fibre material.
  • a preheater 6 is provided which is connected to a disc refiner 7.
  • This refiner is provided with a refiner casing, which can be pressurized.
  • a steam separator 8 preferably a cyclone, is located, to which an outlet conduit 9 for pulp is coupled which is connected to a screen 10 via a tank 11 for so-called latency-removal.
  • a second accept conduit 12 extends which is connected to the accept conduit 2, and a second reject conduit 13 extending from the screen 10 leads to the dewatering device 4.
  • the steam outlet conduit 1. is connected to the mixing device 5. It is also possible to pass the entire processed reject fraction from the tank 11 directly to the accept conduit 2.
  • the refined reject fraction possibly can be returned to the pulp before the screen 1 or the combination of screens represented in the flow chart by this screen.
  • the incoming mechanical pulp is divided by screening in the screen 1 into an accept fraction 2 and a reject fraction
  • the screening can be carried out in several steps in order thereby to increase the shives and long fibre content in the reject.
  • the reject fraction shall constitute 10-40% of the incoming pulp and substantially comprise the entire shives and long fibre content of the pulp.
  • the reject fraction thereafter is dewatered to a concentration above 30% dry solids content, whereafter it is transferred to the mixing device 5, which preferably consists of a combined mixing and processing device of the kind shown in the International Patent Application PCT/SE85/ 00-441.
  • the mixing device is charged with 10-50 kg, preferably 15-40 kg of sodium sulphite per ton of dry matter.
  • the reject fraction thus, is impregnated at a high material concentration, and as simultaneously the mechanical processing is carried out the impregnation agent is kneaded into the fibre material.
  • the heating to desired preheating temperature, 105-170oC, preferably 105-135oC takes place in the mixing device by steam supply.
  • the kneading balances the chemical and temperature profile in the fibre material and simultaneously a certain defibration takes place.
  • the energy input here shall be 35-100 kWh per ton of dry matter.
  • the pulp is fed from the mixing device 5 into the preheater ⁇ where the temperature 105-170°C, preferably 105-135°C, is maintained.
  • the staying time shall be 1-30 minutes, preferably 5-10 minutes, so that the impregnation agent admixed in the mixing device 5 is allowed to diffuse into the fibre wall and react.
  • the material after the preheating is fed into the disc refiner 7 to be refined at overpressure and at a temperature exceeding the temperature in the preheater.
  • the temperature in the inlet to the refiner shall be 105-145oC, preferably 105-135°C. This implies that the feed from the preheater 6 to the refiner 7 in certain cases must be made air-tight.
  • Such a pressure sluice preferably is obtained by a conical screw-feeder, which transfers the material in the form of an air-tight plug.
  • the refining is carried out with an energy charge of 300-1000, preferably 600-900 kWh per ton dry matter to a freeness lower than 250, preferably 150 at maximum.
  • the refined pulp is blown from the refiner casing of the refiner to a pressure cyclone 8 for separating steam and pulp under pressure.
  • the pulp is discharged through the conduit 9 , diluted to 3-5% concentration and passed to a tank for latency-removal, which takes place at 60-80oC while the pulp is being agitated for 30-60 minutes.
  • the pulp is screened in the screen 10, and a second reject fraction is returned through the conduit 13 to the dewatering device 4 while a second accept fraction is passed to the main accept conduit 2.
  • This second reject fraction constitutes 10-30% of the refined reject fraction and contains substantially the residual shives fraction.
  • the steam from the pressure cyclone 8 is discharged through the conduit 14. This steam is recycled to the mixing device 5 and to the preheater 6 for heating the reject fraction prior to the refining as described above. This steam is sufficient for bringing about the desired heating to 107-170oC.
  • the system hereby is self-supporting in respect of heating steam.
  • Column I shows data for only one reject fraction of groundwood processed according to the invention
  • Column II shows data for the entire groundwood inclusive of the reject fraction according to Column I
  • Column III shows data for the reject fraction of groundwood, which only was refined at high concentration
  • Column IV shows data for the entire groundwood inclusive of the reject fraction according to Column III. I II III IV
  • thermomechanical pulp we have found that the shives content could be reduced and the density of the entire pulp, especially of the long fibre fraction, has increased. The number of stiff fibres of the pulp also was reduced without considerably deteriorating the light scattering of the pulp.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Inorganic Chemistry (AREA)
  • Paper (AREA)

Abstract

Le traitement décrit comprend une opération de tamisage, destinée à diviser la cellulose en une partie acceptée et en une partie rejetée, la partie rejetée constituant de 10 à 40% de l'ensemble. La partie rejetée est déshydratée, impregnée par du sulphite de sodium et préchauffée à la vapeur. Un raffinage est ensuite effectué sous pression et par traitement à la vapeur. On n'utilise que cette vapeur pour préchauffer la partie rejetée. Après raffinage, un traitement dit latent est effectué, la partie rejetée venant ensuite rejoindre la cellulose de bois, éventuellement par l'intermédiaire d'une opération de tamisage supplémentaire.
PCT/SE1987/000124 1986-04-02 1987-03-12 Procede de traitement de cellulose de bois WO1987005954A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
NO875001A NO875001L (no) 1986-04-02 1987-12-01 Fremgangsmÿte for fremstilling av mekanisk masse.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8601477-6 1986-04-02
SE8601477A SE8601477L (sv) 1986-04-02 1986-04-02 Sett for behandling av mekanisk massa

Publications (1)

Publication Number Publication Date
WO1987005954A1 true WO1987005954A1 (fr) 1987-10-08

Family

ID=20364022

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1987/000124 WO1987005954A1 (fr) 1986-04-02 1987-03-12 Procede de traitement de cellulose de bois

Country Status (4)

Country Link
JP (1) JPH01501953A (fr)
AU (1) AU7201887A (fr)
SE (1) SE8601477L (fr)
WO (1) WO1987005954A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5108909A (en) * 1985-03-22 1992-04-28 Chiron Corporation Expression of TPA in mammalian cells
US5423993A (en) * 1993-08-06 1995-06-13 John A. Boney Fiber recovery system and process
WO2000053844A1 (fr) * 1999-03-08 2000-09-14 Holmen Aktiebolag Procede de fabrication de pulpe mecanique et chimiothermomecanique blanchie
WO2008153565A1 (fr) * 2007-06-12 2008-12-18 Meadwestvaco Corporation Mélange de fibres présentant un rendement élevé et des performances de pâte améliorées, et son procédé de fabrication
US8877007B2 (en) 2012-08-21 2014-11-04 University Of New Brunswick System and method for reclaiming rejects in sulfite pulping
WO2017204723A1 (fr) * 2016-05-23 2017-11-30 Holmen Ab Procédé de fourniture d'une composition de fibres de papier
US10060075B2 (en) 2007-06-12 2018-08-28 Westrock Mwv, Llc Fiber blend having high yield and enhanced pulp performance and method for making same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5729095B2 (ja) * 2011-03-31 2015-06-03 日本製紙株式会社 広葉樹機械パルプの製造方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4270976A (en) * 1976-11-23 1981-06-02 Defibrator Ab Method of producing peroxide bleached pulp
SE422088B (sv) * 1978-11-24 1982-02-15 Mo Och Domsjoe Ab Forfarande for framstellning av slipmassa av lignocellolusahaltiga material
EP0096548A1 (fr) * 1982-06-04 1983-12-21 Macmillan Bloedel Limited Traitement chimique en deux étapes d'une pâte de bois mécanique

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4270976A (en) * 1976-11-23 1981-06-02 Defibrator Ab Method of producing peroxide bleached pulp
SE422088B (sv) * 1978-11-24 1982-02-15 Mo Och Domsjoe Ab Forfarande for framstellning av slipmassa av lignocellolusahaltiga material
EP0096548A1 (fr) * 1982-06-04 1983-12-21 Macmillan Bloedel Limited Traitement chimique en deux étapes d'une pâte de bois mécanique

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Canadian Pulp and Paper Association Preprints 68 B, January 1982, A.C. SHAW, "The Opco Process Applied to TMP Screened Rejects". *
Pulp and Paper International, Vol. 22, December 1980, p. 54-56, GAVELIN, "A Single TMP Furnish - The Monopulp Process". *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5108909A (en) * 1985-03-22 1992-04-28 Chiron Corporation Expression of TPA in mammalian cells
US5423993A (en) * 1993-08-06 1995-06-13 John A. Boney Fiber recovery system and process
WO2000053844A1 (fr) * 1999-03-08 2000-09-14 Holmen Aktiebolag Procede de fabrication de pulpe mecanique et chimiothermomecanique blanchie
US7736463B1 (en) 1999-03-08 2010-06-15 Holmen Aktiebolag Method for manufacturing bleached mechanical and chemithermomechanical pulp
WO2008153565A1 (fr) * 2007-06-12 2008-12-18 Meadwestvaco Corporation Mélange de fibres présentant un rendement élevé et des performances de pâte améliorées, et son procédé de fabrication
WO2008154073A1 (fr) * 2007-06-12 2008-12-18 Meadwestvaco Corporation Fibre présentant un rendement élevé et des performances améliorées
EP2672005A1 (fr) * 2007-06-12 2013-12-11 MeadWestvaco Corporation Fibre présentant un rendement éléve et des performances améliorées
EP2672004A1 (fr) * 2007-06-12 2013-12-11 MeadWestvaco Corporation Fibre présentant un rendement élévé et des performances améliorées
US10000889B2 (en) 2007-06-12 2018-06-19 Westrock Mwv, Llc High yield and enhanced performance fiber
US10060075B2 (en) 2007-06-12 2018-08-28 Westrock Mwv, Llc Fiber blend having high yield and enhanced pulp performance and method for making same
US8877007B2 (en) 2012-08-21 2014-11-04 University Of New Brunswick System and method for reclaiming rejects in sulfite pulping
WO2017204723A1 (fr) * 2016-05-23 2017-11-30 Holmen Ab Procédé de fourniture d'une composition de fibres de papier

Also Published As

Publication number Publication date
AU7201887A (en) 1987-10-20
SE8601477L (sv) 1987-10-03
JPH01501953A (ja) 1989-07-06
SE8601477D0 (sv) 1986-04-02

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