US3078208A - Method for the production of neutral sulfite pulp - Google Patents

Method for the production of neutral sulfite pulp Download PDF

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Publication number
US3078208A
US3078208A US839071A US83907159A US3078208A US 3078208 A US3078208 A US 3078208A US 839071 A US839071 A US 839071A US 83907159 A US83907159 A US 83907159A US 3078208 A US3078208 A US 3078208A
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US
United States
Prior art keywords
pulp
impregnation
solution
brightness
chips
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Expired - Lifetime
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US839071A
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English (en)
Inventor
Cederquist Karl Nicolaus
Eftring Karl Esbjorn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Stora Enso Oyj
Original Assignee
Stora Kopparbergs Bergslags AB
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Publication of US3078208A publication Critical patent/US3078208A/en
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Classifications

    • 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
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
    • D21C3/06—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides sulfur dioxide; sulfurous acid; bisulfites sulfites

Definitions

  • Neutral sulfite pulp usually is produced in yields of 65 to 90% by digesting wood with a disodium sulfite solution buffered with soda at temperatures within the range of 160 to 180 C. and by subsequent mechanical defibra-.
  • a pure sodium sulfite solution has a pH of about 9.5 and is void of buffering capacity.
  • the digesting liquor generally is prepared by dissolving therein sodium sulfite and sodium carbonate or bicarbonate but in some cases it is prepared also by introducing S0 into a soda solution, until the desired proportion of sodium sulfite and sodium carbonate is obtained.
  • a steaming of the wood chips greatly facilitates the ice impregnation and the duration of the steaming is dependent upon the type of the wood, percentage dry weight, the size of the wood chips, etc. For chips made of various types of birchwood it has, for instance, been necessary to vary the steaming period between 5 and 10 minutes to obtain a satisfactory impregnation.
  • the duration of the impregnation is at least as important as the temperature to obtain a perfectly satisfactory impregnation. We have found that, to attain a satisfactory result with respect to impregnation, it is necessary that well steamed wood chips be contacted with the impregnation solution for at least 30 minutes and that the impregnation time frequently must be extended to 60 to 120 minutes.
  • the impregnation time may be substantially shortened. Tests have shown however, that the impregnation time cannot be made shorter than 3 to 10 minutes, if for instance birch wood pulp is to get a brightness of about 60 to 65 GE.
  • an impregnation liquor prepared by introducing $0 into a sodium hydroxide solution to a pH within the range of 9.5 to 6, preferably between about 7.5 to 6.5, is more suitable than any other sulfite solution for the production of neutral sulfite pulp of high brightness at a yield of between 80 and 90%.
  • the cooking must be carried out in such a manner that after' completed cooking the pH value resides between 4.5 and 6.5 and the cooking temperature between and C., which for the highest temperature corresponds to a cooking time of 15 to 20 minutes and for the lowest temperature to a cooking time of 60 to 70 minutes. It should be 3 strength at a high yield of 80 to 90% and of a brightness Quits su fici nt fo h p od ctio o wsp i and m azine paper.
  • the present invention has as an object the provision of a method for the production of semichemical neutral sultite pulp, said method being characterized by the steps of carefully impregnating wood chips, which have been steamed, with a solution of sodium sulfite and bisulfite having a pH of about 9.5 to 6 and void of free or combined carbonic acid, removing the excess of impregnation solution Without any free liquor, digesting the pulp at a temperature of 165 to 175 C and subsequently defibrating the pulp.
  • the wood chips are steamed, compressed and subsequently expanded in the impregnation liquor after having been maintained therein for at least 3 minutes, and preferably more than 10 minutes.
  • the pulp suspension is freed from waste liquor by compressing to increase the dry content Without adding any dilution water. Since according to the method described the digestion is effected without any free liquor, it may be necessary after the coarse defibration to add a minor quantity of liquor to facilitate the conveyance of the pulp. Then preferably undiluted waste liquor from the press should be used.
  • the compression is suitably effected in continuous presses such as screw presses or disc presses of a type common in the wood pu ind r Even through a compression to a dry content of 30% prior to the dilution with Water, there is obtained an increase of the brightness of about 2 GE.
  • the pulp is diluted with water to a concentration of 3 to 4%, refined, diluted, washed and formed to a paper web.
  • the determination of the brightness was performed with the paper thus obtained.
  • a method comprising preparing semichemical neutral snlfite pulp in a yield of at least about and to a brightness of at least 60 GE. by the steps of making an tmbutfered solution consisting of sodium sulfite and bisulfite and in a pH range of 9.5 to 6, thoroughly steaming Wood chips, subsequently impregnating said chips with said solution at a temperature no greater than about C., removing all free solution to provide a dry content of at least 30%, digesting the chips in steam in the absence of free solution at a temperature of from to C., and defibrating the resulting pulp.

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  • Paper (AREA)
US839071A 1958-09-11 1959-09-10 Method for the production of neutral sulfite pulp Expired - Lifetime US3078208A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE865658 1958-09-11
SE768259 1959-08-18

Publications (1)

Publication Number Publication Date
US3078208A true US3078208A (en) 1963-02-19

Family

ID=26654793

Family Applications (1)

Application Number Title Priority Date Filing Date
US839071A Expired - Lifetime US3078208A (en) 1958-09-11 1959-09-10 Method for the production of neutral sulfite pulp

Country Status (7)

Country Link
US (1) US3078208A (xx)
BE (1) BE582569A (xx)
CH (1) CH379256A (xx)
DE (1) DE1262754B (xx)
FI (1) FI40601B (xx)
FR (1) FR1236223A (xx)
GB (1) GB885605A (xx)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3383277A (en) * 1967-02-06 1968-05-14 Scott Paper Co Two-stage pulping process with an isothermal first stage
US3533906A (en) * 1967-10-11 1970-10-13 Haigh M Reiniger Permanently reacted lignocellulose products and process for making the same
US3769152A (en) * 1970-05-13 1973-10-30 Mo Och Domsjoe Ab Digestion of wood with oxygen in the presence of alkali
US4116758A (en) * 1976-05-14 1978-09-26 Canadian International Paper Co. Method of producing high yield chemimechanical pulps
WO2007140837A3 (de) * 2006-06-08 2008-04-03 Voith Patent Gmbh Verfahren zum herstellen von faserstoff
WO2008077450A1 (de) * 2006-12-23 2008-07-03 Voith Patent Gmbh Verfahren zur herstellung von tissuepapier
WO2009015699A1 (de) * 2007-07-31 2009-02-05 Voith Patent Gmbh Lignocellulosischer faserstoff aus einjahrespflanzen

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007008955A1 (de) * 2007-02-21 2008-08-28 Voith Patent Gmbh Verfahren zum Herstellen von Faserstoff aus Holz

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US215728A (en) * 1879-05-27 Improvement in the manufacture of paper-pulp from wood
US2640774A (en) * 1953-01-27 1953-06-02 Pulp And Papen Res Inst Of Can Production of cellulose pulp
US2858213A (en) * 1956-04-20 1958-10-28 Condi Engineering Corp Wood chip digestion
US2862813A (en) * 1952-12-23 1958-12-02 Process Evaluation Devel Semi-chemical pulping process
US2975096A (en) * 1957-11-18 1961-03-14 Bauer Bros Co Impregnation of wood chips

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2809111A (en) * 1956-02-13 1957-10-08 Condi Engineering Corp Apparatus for wood chip digestion

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US215728A (en) * 1879-05-27 Improvement in the manufacture of paper-pulp from wood
US2862813A (en) * 1952-12-23 1958-12-02 Process Evaluation Devel Semi-chemical pulping process
US2640774A (en) * 1953-01-27 1953-06-02 Pulp And Papen Res Inst Of Can Production of cellulose pulp
US2858213A (en) * 1956-04-20 1958-10-28 Condi Engineering Corp Wood chip digestion
US2975096A (en) * 1957-11-18 1961-03-14 Bauer Bros Co Impregnation of wood chips

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3383277A (en) * 1967-02-06 1968-05-14 Scott Paper Co Two-stage pulping process with an isothermal first stage
US3533906A (en) * 1967-10-11 1970-10-13 Haigh M Reiniger Permanently reacted lignocellulose products and process for making the same
US3769152A (en) * 1970-05-13 1973-10-30 Mo Och Domsjoe Ab Digestion of wood with oxygen in the presence of alkali
US4116758A (en) * 1976-05-14 1978-09-26 Canadian International Paper Co. Method of producing high yield chemimechanical pulps
WO2007140837A3 (de) * 2006-06-08 2008-04-03 Voith Patent Gmbh Verfahren zum herstellen von faserstoff
US20090314443A1 (en) * 2006-06-08 2009-12-24 Esa-Matti Aalto Method for producing fibrous material
WO2008077450A1 (de) * 2006-12-23 2008-07-03 Voith Patent Gmbh Verfahren zur herstellung von tissuepapier
US20090266500A1 (en) * 2006-12-23 2009-10-29 Hans-Ludwig Schubert Process for producing tissue paper
WO2009015699A1 (de) * 2007-07-31 2009-02-05 Voith Patent Gmbh Lignocellulosischer faserstoff aus einjahrespflanzen

Also Published As

Publication number Publication date
DE1262754B (de) 1968-03-07
FI40601B (xx) 1968-11-30
GB885605A (en) 1961-12-28
CH379256A (de) 1964-06-30
BE582569A (fr) 1959-12-31
FR1236223A (fr) 1960-07-15

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