EP0281273B1 - Zellstoff - Google Patents

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Publication number
EP0281273B1
EP0281273B1 EP19880301311 EP88301311A EP0281273B1 EP 0281273 B1 EP0281273 B1 EP 0281273B1 EP 19880301311 EP19880301311 EP 19880301311 EP 88301311 A EP88301311 A EP 88301311A EP 0281273 B1 EP0281273 B1 EP 0281273B1
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EP
European Patent Office
Prior art keywords
pulp
paper
carbon dioxide
stream
gaseous carbon
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Expired - Lifetime
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EP19880301311
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English (en)
French (fr)
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EP0281273A1 (de
Inventor
George H. Hollerbach, Jr.
Walter Kleinberg
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Linde LLC
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BOC Group Inc
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Application filed by BOC Group Inc filed Critical BOC Group Inc
Priority to AT88301311T priority Critical patent/ATE91734T1/de
Publication of EP0281273A1 publication Critical patent/EP0281273A1/de
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/04—Addition to the pulp; After-treatment of added substances in the pulp
    • D21H23/06—Controlling the addition
    • D21H23/08—Controlling the addition by measuring pulp properties, e.g. zeta potential, pH
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/65—Acid compounds

Definitions

  • This invention relates to the preparation of cellulosic pulps, and more particularly to the chemical treatment of alkaline cellulosic pulp prior to processing in a paper making assembly.
  • the digestion of cellulosic materials is primarily carried out utilising either soda, sulphate, sulphite or neutral sulphite processes and is sometimes performed by batch methods, i.e., particulate cellulosic materials in relatively small pieces or chips and delignifying chemicals in aqueous solution are introduced into a pressure cooker or digester wherein the mixture is raised to delignifying temperatures and thereafter discharged as concentrated pulp and spent liquor for further processing operations.
  • Continuous methods are also known. Processing data for determining delignifying conditions, such as strength of the chemicals, time and temperature, are determined to a great extent from actual experience rather than from correlated laboratory data, since the severity of the chemical attack on the charged cellulosic materials varies considerably even within wood species.
  • the delignified cellulosic material from the digester is introduced into a blow tank for dilution with diluting liquors to a pumpable consistency of from 1.5 to 4 percent solids for the separation and recovery of the cooking chemicals and prior to refining and further treatment of the cellulosic pulp slurry for introduction to a paper making machine, such as a Fourdrinier machine.
  • sizing agents are employed to make papers resistant to penetration of certain liquids; clays and other pigments to improve brightness, opacity, and printing properties; starches and gums to improve fibre bonding and fibre distribution; various synthetic polymers to impart wet strength; dyes and coloured pigments to give desired colour; surface active agents to improve absorbency, combat self-sizing, and decrease foam and pitch troubles.
  • cellulosic pulp slurries are advantageously processed with such additives at a pH of from about 4.5 to 7.0.
  • Cellulosic pulps produced by alkaline pulping techniques are at a pH of from about 12.0 to 10.0 and require extensive chemical treatment, e.g., a first treatment with sulphuric acid, to bring the resulting cellulosic pulp into the appropriate pH range of from 9.5 to 7.5 for effective treatment with such hereinbefore described additives.
  • US-A-2 114 809 relates to the production of sized paper from a pulp stock which may be of the sulphite, soda or kraft kind.
  • the pulp has added to it a carbonate filler such as chalk and a sizing agent such as alum.
  • Reaction takes place in solution between the alum and the chalk to form carbon dioxide.
  • This reaction and subsequent processing steps take place in closed vessels so as to ensure that some of the carbon dioxide dissolves by virtue of a partial pressure of carbon dioxide in the ullage spaces of the vessels.
  • a sufficient quantity of carbon dioxide may also be introduced into the vessels from some outside source.
  • a process for manufacturing paper from alkaline cellulosic pulp produced by the delignification of cellulosic material wherein thus produced alkaline delignified cellulosic pulp is fibrilated in a refiner to form paper-forming pulp, and introducing gaseous carbon dioxide into said delignified pulp, characterised in that said gaseous carbon dioxide is introduced upstream of the fibrilation step in an amount to form a precursor paper-forming pulp stream having a pH of from 8.5 to 6.5, and the introduction of carbon dioxide is regulated in response to measurements of the pH of the precursor paper-forming pulp stream.
  • the invention also provides an apparatus for manufacturing paper wherein delignified cellulosic pulp is fibrilated in a refiner to form paper-making pulp, including means for injecting and dispersing gaseous carbon dioxide into a delignified cellulosic pulp stream, characterised in that said means is located upstream of said refiner so as to enable carbon dioxide to be injected in an amount to form a precursor paper-forming pulp stream having a pH of from 8.5 to 6.5 and the apparatus further includes means for sensing the pH of said paper-forming pulp stream and regulating the introduction of carbon dioxide in response to the sensed pH so as to maintain a desired pH.
  • the pH said pH is regulated to be in the range of from 6.5 to 8.5 since a pH of greater than about 8.5 provides minimal benefits and a pH of less than about 6.5 requires excessive carbon dioxide.
  • a pH in the range 8.5 to 7.5 is preferred.
  • gaseous carbon dioxide is also introduced into the refined pulp under conditions to adjust and maintain at from about 7.0 to 5.5 the pH of the pulp stream prior to introduction into a paper making assembly.
  • a pH in the range of 6.0 to 5.5 is more preferred.
  • the invention makes possible the manufacture of paper of improved physical properties.
  • the invention also makes possible better pulp drainage thereby permitting paper forming with reduced energy requirements, for drying.
  • Other advantages that may be derived from the use of the invention include improved operation of the paper making machine, a reduction an rejected paper, and reduced requirements for certain chemical additives (e.g. alum or aluminium sulphate).
  • a paper making machine such as a Fourdrinier machine, generally indicated as 10 and including a headbox 12 for distributing paper-forming pulp stock onto the moving screen 36 of the Fourdrinier machine 10.
  • Cellulosic pulp material produced by standard alkaline pulping techniques are introduced into a blow tank (not shown), washed and stored in a chest 14 and combined with white water in line 16 to a pumpable consistency of about 1.5 to 5.0 percent, generally about 4 percent solids, and passed in line 18 to the suction side of a pump 20.
  • a pulp slurry in line 22 from the discharge side of the pump 20 is contacted with gaseous carbon dioxide from line 21 by an injection assembly 25 to form a combined stream in line 26.
  • Gaseous carbon dioxide is added in an amount sufficient to provide a pH of from about 8.5 to about 6.5, in the combined pulp stream which is passed through a refiner 28 to fibrilate the cellulosic pulp material.
  • the line 30 downstream from the refiner 28 contains a second injecting assembly 60 for contacting the refined pulp stream with additional gaseous carbon dioxide from line 21.
  • Gaseous carbon dioxide is added in an amount sufficient to provide a combined stream in downstream line 62 having a pH in the range from about 7.0 to 5.5.
  • the pulp from line 62 is mixed with white water in line 46 to a solids consistency of about 0.4 percent and passed through pump 32 and line 34 to a headbox 12.
  • a sizing precursor such as alum
  • the alum may be introduced as a liquid into line 30, line 46 or directly into the headbox 12 (as shown).
  • the pulp in headbox 12 is distributed onto the endless woven-wire belt 36 of the Fourdrinier machine 10.
  • a liquid (hereinabove referred to as "white water”) is drained from the cellulosic pulp sheet being formed, and the pulp sheet is dried and passed to further processing steps in the formation of finished paper, generally in the form of a roll.
  • the white water 40 drained from the cellulosic pulp-during distribution on the endless woven-wire belt 36 is collected in a sump 38 of the Fourdrinier machine 10 and is passed to a mixing tank 42, called a wire pit, to which are added by line 44 other additive chemicals as required for manufacturing a specific paper product.
  • a purge stream of the white water is generally continually withdrawn through line 45 to maintain chemicals, such as sulphate ions, at certain predetermined levels in the recycling white water stream in line 46.
  • the gaseous carbon dioxide in line 21 is at a pressure of about 377 kPa to 1380 kPa (about 40 to 200 psig), and is preferably at a pressure of from 69 to 138 kPa (10 to 20 psi) greater than the pressure of the cellulosic pulp in line 22.
  • the gaseous carbon dioxide injection assembly 25 is a porous metal sparger, preferably, in combination with a static mixer which provides good gas dispersion and maximum transfer efficiency. Suitable spargers and static mixers are commercially available from a number of manufacturers.
  • Proper addition of the gaseous carbon dioxide permits rapid and intimate mixing in the cellulosic pulp such that a uniform, predetermined resulting pH level is readily attained in line 26 at a point downstream of the discharge side of the pump 20 and prior to introduction into a subsequent unit operation, e.g., the refiner 28.
  • the pH of the treated pulp slurry is measured with a meter assembly 50 having a pH probe 52 in line 26.
  • a meter output is used to generate a feedback control signal to operate a valve 56 in line 21 to regulate the flow of carbon dioxide in line 24 to achieve the desired pH level in the pulp stream.
  • Line 24 also contains a check valve 27.
  • the second gaseous carbon dioxide injecting assembly 60 is a porous metal sparger; adequate mixing may be obtained without a second static mixer.
  • a second meter assembly 64 having a pH probe 66 in line 62 measures the pH and provides a control signal to operate a second valve 68 connected in line 70 between carbon dioxide line 21 and the second injecting assembly 60.
  • Line 70 also contains a check valve 72.
  • the pressure of carbon dioxide in line 21 is preferably at a pressure of from about 170 to 24 kPa (about 10 to 20 psig) greater than the pressure of the refined pulp stream in line 30.
  • a concentrated pulp stream of a pH of 11.0 and a density of 15 percent solids produced by kraft processing of soft wood is diluted with white water to a consistency of 4 to 5 percent solids and a resulting pH of 10.5.
  • the diluted pulp stream is introduced into and passed (with trim dilution, as required) to the suction side of a pulp pump 20 at a rate of 132 litres per second (2100 GPM (gallons per minute)).
  • Alum is added to the refined pulp stream at a rate of 0.79 kg per second (10.4 pounds per minute).
  • the thus treated refined pulp stream is thereupon further diluted with white water to a solids content of 0.4 percent and a pH of about 4.5 before introduction into the headbox 12 of the Fourdrinier machine 10 for processing into paper.
  • the controlled introduction of carbon dioxide before the refining step results in stronger paper as a result of improved refining when compared to the introduction of sulphuric acid to adjust pH prior to the refining step.
  • dilute pulp streams of a solids content of about 4 to 5 percent solids are produced by kraft pulp processing from hard and soft woods.
  • a dilute soft wood pulp stream and a dilute hard wood pulp are combined to form a primary line pulp stream to be refined to form the dilute pulp stream to be diluted by white water to a solids content of about 0.4 percent for introduction into the primary headbox of the paper machine.
  • the dilute soft wood pulp stream having a solids content of 4 to 5 percent and a pH of 10.5 is passed (including trim white water) to the suction side of a pulp pump at a rate of 189 litres per second (3000 GPM).
  • a pulp pump to the dilute pulp stream (solids content 4 percent) in the downstream conduit from the pulp pump, there is added 4.71 kg (10.4 pounds) per minute of gaseous carbon dioxide.
  • the resulting pulp stream at a pH of 7.0 is introduced into a primary refiner prior to being combined in a secondary refiner with a dilute hard wood pulp stream pH of 7.0.
  • the dilute hard wood pulp stream having a solids content of 4 to 5 percent and a pH of 10.5 is passed (including trim white water) to the suction side of a pulp pump at a rate of 57 litres per second (900 GPM).
  • a pulp pump at a rate of 57 litres per second (900 GPM).
  • 0.24 kg per second (3.1 pounds per minute) of gaseous carbon dioxide to form the dilute hard wood pulp stream at a pH of 7.0 introduced into the secondary refiner.
  • the combined pulp stream is further diluted with white water (recovered from the wire pit of the paper machine and acidified with sulphuric acid) to a solids content of 0.4 percent and a pH of about 4.5 before introduction into a primary headbox.
  • To the primary headbox there is added 1.03 kg of alumn per second (13.5 pounds of alum per minute).
  • the top sheet for the paper board is produced from a dilute soft wood pulp stream of a solids content of 4 to 5 percent which is introduced (together with trim white water) into the suction side of a pulp pump at a rate of 40 litres per second (650 GPM) to form a dilute pulp stream having a solids content of 4 percent in the discharge conduit therefrom.
  • a pulp pump at a rate of 40 litres per second (650 GPM) to form a dilute pulp stream having a solids content of 4 percent in the discharge conduit therefrom.
  • the thus refined pulp stream (pH 7.0) is withdrawn from the secondary refiner and mixed with white water (recovered from the wire pit of the paper machine and acidified with sulphuric acid) for dilution to a further diluted pulp stream of a solids content of 0.4 percent and a pH of about 4.5 before introduction into the primary headbox together with alum at the rate of 0.95 kg (2.1 pounds) per minute.
  • a concentrated pulp stream of pH of 11.0 and a density of 15 percent solids produced by kraft processing of soft wood and hard wood is diluted to a consistency of 4 to 5 percent solids and a resulting pH of 10.5.
  • the diluted pulp stream is introduced into and passed (with trim dilution, as required) to the suction side of a pulp pump 20 at a rate of 126 litres per second (2000 GPM).
  • gaseous carbon dioxide is added to the dilute pulp stream in the downstream pipe 26 from the pulp pump.
  • Additional gaseous carbon dioxide is added at a rate of 0.11 kg per second (1.4 pounds per minute) to the refined pulp in line 30 downstream from the refiner to form a combined stream in pipe 62 having a pH of 5.5.
  • Alum is added to the refined pulp stream at a rate of 0.51 kg per second (6.7 pounds per minute).
  • the thus treated refined pulp stream is thereupon further diluted with white water to a solids content of 0.4 percent and a pH of about 5.0 before introduction into the headbox 12 of the Fourdrinier machine 10 for processing into paper.
  • No sulphuric acid is used.
  • the use of sulphuric acid is eliminated, and the amounts of gaseous carbon dioxide introduced into the raw and refined pulp stream are individually selected to obtain optimum operation of the refiner 28 and the paper making machine 10.
  • the pH of the pulp stream in line 26 before the refiner is preferably in the range from about 8.5 to about 7.5.
  • the pH of the white water 40 in the wire pit 42 of a paper making assembly is usually in the range 7.0 to 4.5, typically between 5.5 and 4.5,
  • the pH of the pulp stream in line 62 following the refiner is preferably in the range from about 6.0 to about 5.5.
  • the use of carbon dioxide to lower the pH of a combined stream to a value less than about 5.5 is usually uneconomical because increasing amounts of carbon dioxide are required.
  • gaseous carbon dioxide significantly reduces the build up of barium sulphate (barium is present in the cellulosic raw material) and concomitant scaling of the paper making assembly therewith, thereby reducing the frequency of "boil-out" protocols which temporarily shut down the paper-making line.
  • gaseous carbon dioxide in processing of recycled paper products has significantly improved the operation of the paper machines and associated equipment.

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  • Paper (AREA)
  • Treating Waste Gases (AREA)
  • Carbon And Carbon Compounds (AREA)

Claims (11)

  1. Verfahren zur Herstellung von Papier aus alkalischer Zellulosepulpe, hergestellt durch Ligninentfernung aus zelluloseartigem Material, wobei die so hergestellte, alkalische, von Lignin befreite Zellulosepulpe in einem Refiner unter Bildung von papierbildender Pulpe zerfasert wird, und gasförmiges Kohlendioxid in diese von Lignin befreite Pulpe eingeführt wird, dadurch gekennzeichnet, daß dieses gasförmige Kohlendioxid strömungsaufwärts von der Zerfaserungsstufe in einer Menge, um einen Vorläufer der papierbildenden Pulpenströmung mit einem pH von 8,5 bis 6,5 zu bilden, eingeführt wird, und die Einführung von Kohlendioxid ansprechend auf die Messungen des pH des Vorläufers der papierbildenden Pulpenströmung reguliert wird.
  2. Verfahren nach Anspruch 1, worin Kohlendioxid in einer Menge zugesetzt wird, um den pH eines Vorläufers der papierbildenden Pulpenströmung auf einen Wert von 8,5 bis 7,5 zu einzustellen.
  3. Verfahren nach Anspruch 1 oder Anspruch 2, worin eine aus einem Papierherstellungsvorgang erhaltene flüssige Strömung mit dieser von Lignin befreiten Zellulosepulpe vermischt wird, um diese papierbildende Pulpe zu bilden, die mit dem gasförmigen Kohlendioxid in Kontakt zu bringen ist.
  4. Verfahren nach Anspruch 3, worin diese flüssige Strömung mit dieser von Lignin befreiten Zellulosepulpe vermischt wird und in eine Ansaugseite einer Pulpenpumpe eingeführt wird, und worin gasförmiges Kohlendioxid in diese aus dieser Pulpenpumpe abgegebene papierbildende Pulpe eingeführt wird.
  5. Verfahren nach einem der vorhergehenden Ansprüche, weiter dadurch gekennzeichnet, daß in die zerfaserte Pulpe gasförmiges Kohlendioxid in einer Menge eingeführt wird, um einen Vorläufer der papierbildenden Pulpenströmung mit einem pH von 7,0 bis 5,5 zu bilden.
  6. Verfahren nach Anspruch 5, worin das gasförmige Kohlendioxid zu der zerfaserten Pulpe in einer Menge zugesetzt wird, um den pH dieses Vorläufers der papierbildenden Pulpenströmung auf einen Wert in dem Bereich von 6,0 bis 5,5 einzustellen.
  7. Verfahren nach einem der vorhergehenden Ansprüche, weiter umfassend das Mischen der aus einem Papierherstellungsvorgang erhaltenen, flüssigen Strömung mit der Strömung von zerfaserter Pulpe, nachdem sie mit dem gasförmigen Kohlendioxid in Kontakt gebracht worden ist.
  8. Verfahren nach einem der vorhergehenden Ansprüche, bei welchem keine Schwefelsäure zu der alkalischen Zellulosepulpe zugesetzt wird.
  9. Vorrichtung zur Herstellung von Papier, bei welchem von Lignin befreite Zellulosepulpe in einem Refiner (28) zur Bildung von papierbildender Puple zerfasert wird, einschließend Einrichtungen (25) zum Injizieren und Dispergieren von gasförmigem Kohlendioxid in eine von Lignin befreite Zellulosepulpenströmung, dadurch gekennzeichnet, daß diese Einrichtung strömungsaufwärts von diesem Refiner (28) angeordnet ist, so daß Kohlendioxid in einer Menge injiziert werden kann, um einen Vorläufer einer papierbildenden Pulpenströmung mit einem pH von 8,5 bis 6,5 zu bilden, und die Vorrichtung weiter Einrichtungen (52, 50, 56) einschließt, um den pH dieser papierbildenden Pulpenströmung abzutasten und die Einführung von Kohlendioxid ansprechend auf den abgetasteten pH einzuregulieren, so daß der gewünschte pH aufrecht erhalten wird.
  10. Vorrichtung nach Anspruch 9, weiter einschließend Einrichtungen (60) zum Injizieren und Dispergieren von gasförmigem Kohlendioxid in eine zerfaserte Zellulosepulpenströmung in einer Menge zur Bildung eines Vorläufers von papierbildender Pulpenströmung, der einen pH von 7,0 bis 5,5 aufweist, strömungsabwärts von dem Refiner (28).
  11. Vorrichtung nach Anspruch 10, weiter einschließend Einrichtungen (66, 64, 68) zum Abtasten des pH dieses Vorläufers von papierbildender Pulpenströmung strömungsabwärts von dem Refiner (28) und zur Regulierung der Einführung von Kohlendioxid im Ansprechen hierauf, so daß ein gewünschter pH strömungsabwärts von dem Refiner (28) aufrecht erhalten wird.
EP19880301311 1987-02-27 1988-02-17 Zellstoff Expired - Lifetime EP0281273B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88301311T ATE91734T1 (de) 1987-02-27 1988-02-17 Zellstoff.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US1983187A 1987-02-27 1987-02-27
US19831 1987-02-27
US14675188A 1988-01-21 1988-01-21
US146751 1988-02-04

Publications (2)

Publication Number Publication Date
EP0281273A1 EP0281273A1 (de) 1988-09-07
EP0281273B1 true EP0281273B1 (de) 1993-07-21

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ID=26692661

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880301311 Expired - Lifetime EP0281273B1 (de) 1987-02-27 1988-02-17 Zellstoff

Country Status (6)

Country Link
EP (1) EP0281273B1 (de)
JP (1) JP2582838B2 (de)
AU (1) AU1175188A (de)
DE (1) DE3882395T2 (de)
FI (1) FI880918A (de)
NO (1) NO880763L (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7175759B2 (en) 2001-12-12 2007-02-13 Linde Aktiengesellschaft Apparatus and a method for controlling the alkalinity and pH of an industrial process

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CA2069713C (en) * 1992-05-27 2003-05-13 Derek Hornsey Carbon dioxide in neutral and alkaline sizing processes
JP3485685B2 (ja) * 1995-08-04 2004-01-13 オリンパス株式会社 屈折率分布型単レンズ
US6200416B1 (en) * 1997-06-10 2001-03-13 Praxair Technology, Inc. Recycled paper production process which incorporates carbon dioxide
FI102911B (fi) * 1997-06-13 1999-03-15 Aga Ab Menetelmä massasuspension pH:n stabiloimiseksi ja paperin tuottamiseks i stabiloidusta massasta
FI104503B (fi) 1997-11-05 2000-02-15 Aga Ab Menetelmä selluloosamassojen suotautuvuuden parantamiseksi
FI103520B1 (fi) 1998-03-03 1999-07-15 Aga Ab Parannetut paperinvalmistusmenetelmät
FI104003B1 (fi) 1999-02-08 1999-10-29 Aga Ab Stabiloitu täyteaine, sen valmistus ja käyttö
FI991241A (fi) * 1999-06-01 2000-12-02 Aga Ab Ligniinin valkaisu ja menetelmä paperin valmistamiseksi
FR2795753B1 (fr) * 1999-07-01 2001-09-14 Carboxyque Francaise Perfectionnement aux procedes de fabrication de produits papetiers en vue de l'incorporation dans lesdits produits de dechets papetiers necessitant un traitement basique
FI20000806A (fi) * 2000-04-05 2001-10-06 Aga Ab Menetelmä lignoselluloosamassan valkaisemiseksi
FR2836938B1 (fr) * 2002-03-07 2004-08-06 Air Liquide Perfectionnement aux procedes de fabrication de produits papetiers par amelioration du comportement physico-chimique de la pate a papier
US7056419B2 (en) 2002-09-30 2006-06-06 American Air Liquide, Inc. Methods for modifying electrical properties of papermaking compositions using carbon dioxide
CN100396849C (zh) * 2003-06-18 2008-06-25 液体空气乔治洛德方法利用和研究的具有监督和管理委员会的有限公司 Co2在造纸工艺湿部中的受控添加
US20040256069A1 (en) * 2003-06-18 2004-12-23 Saucedo Victor M. Estimation and control in the wet end using CO2
FI20060670A0 (fi) * 2006-07-10 2006-07-10 Mikko Kaira Menetelmä kuitutuotteen bulkin lisäämiseksi ja muodostettu kuitutuote
FI20065727A0 (fi) 2006-11-15 2006-11-15 Linde Ag Menetelmä kerrostuman muodostumisen vähentämiseksi sellu- ja paperiteollisuudessa
FI20075638A0 (fi) * 2007-09-13 2007-09-13 Linde Ag Tarttuvan pihkan poistaminen massasuspensiosta, rejektin kalsiumyhdisteiden vähentäminen ja hiilidioksidin käyttö paperinvalmistuksessa
FI20085797L (fi) * 2008-08-27 2010-02-28 Linde Ag Menetelmä puskuriliuoksen valmistamiseksi paperinvalmistusprosessissa
CN110093800A (zh) * 2018-01-30 2019-08-06 广西科开成林科技有限公司 一种湿态机械活化高浓磨浆的方法
NL2025251B1 (nl) * 2020-03-31 2021-02-18 Eska B V Werkwijze voor het in een kartonvervaardigingsinrichting vervaardigen van gekleurd karton, alsmede gekleurd karton vervaardigd door middel van een dergelijke werkwijze.

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DE235821C (de) * 1910-10-11
US1993265A (en) * 1933-02-28 1935-03-05 Merrimac Chemical Co Inc Manufacture of paper embodying alkaline earth metal carbonate fillers
US2114809A (en) * 1934-07-06 1938-04-19 West Virginia Pulp & Paper Com Method of producing sized papers
US3112242A (en) * 1960-05-10 1963-11-26 Int Paper Co Treating a wood pulp slurry with a water-soluble acid prior to addition of sizing materials thereto
JPS4930605A (de) * 1972-07-20 1974-03-19

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7175759B2 (en) 2001-12-12 2007-02-13 Linde Aktiengesellschaft Apparatus and a method for controlling the alkalinity and pH of an industrial process

Also Published As

Publication number Publication date
FI880918A (fi) 1988-08-28
JP2582838B2 (ja) 1997-02-19
JPS6445887A (en) 1989-02-20
FI880918A0 (fi) 1988-02-26
NO880763L (no) 1988-08-29
NO880763D0 (no) 1988-02-22
DE3882395T2 (de) 1993-12-02
AU1175188A (en) 1988-09-01
DE3882395D1 (de) 1993-08-26
EP0281273A1 (de) 1988-09-07

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