Patents Examined by Steve Alvo
  • Patent number: 6602385
    Abstract: A method of improving the brightness of calcium carbonate filled paper. The filled paper is dried and then bleached with an aqueous solution of a bleaching agent. The process may be used on all grades of paper that contain filler and is particularly useful in the bleaching of low brightness grade papers that are produced from mechanical pulp that contain calcium carbonate.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: August 5, 2003
    Assignee: Minerals Technologies Inc.
    Inventor: Donald Kendall Drummond
  • Patent number: 6599390
    Abstract: For a process and an apparatus for loading fibers contained in a pulp suspension with calcium carbonate, a calcium oxide and/or a medium containing calcium hydroxide is fed to the pulp suspension, and the so treated pulp suspension is further charged in several reactors with pure carbon dioxide or a medium containing carbon dioxide. The reactors can be connected in series and/or in parallel. The reactor can produce different forms of calcium carbonate.
    Type: Grant
    Filed: July 12, 2001
    Date of Patent: July 29, 2003
    Assignee: Voith Paper Patent GmbH
    Inventors: Jörg Rheims, Klaus Doelle, Oliver Heise, Werner Witek
  • Patent number: 6589387
    Abstract: The invention relates to a process for improving the drainage or dewatering of cellulosic pulp suspensions in a paper making machine, a drying machine or the like assembly. The invention also relates to a process for producing a dried cellulosic product from said pulp suspension. The drainage of said pulp suspension is improved by treating it with carbon dioxide just prior to its entering a dewatering device such as the wire section of a paper machine.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: July 8, 2003
    Assignee: AGA Aktiebolag
    Inventors: Hannu Juhani Leino, Anna Linnea Holmberg
  • Patent number: 6579411
    Abstract: A method of bleaching cellulose pulp with ozone includes pumping cellulose pulp in form of a fiber suspension having a consistency range of 5 to 25% with a high-consistency pump to a fluidizing Mixture in which oxygen and ozone containing gas is introduced and mixed into the pulp so as to generate a foam whereby the pulp fibers and the ozone used as the bleaching agent are brought to contact with each other, bleached, and the pulp is discharged from the mixer to a reaction vessel.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: June 17, 2003
    Assignee: Andritz Oy
    Inventors: Kaj Henricson, Torolf Laxen, Juhani Peltonen
  • Patent number: 6579412
    Abstract: Provided is a process for bleaching pulp with ozone. The process involves preparing a slurry of cellulosic pulp having a consistency in fibers of from 1-5 weight %. Such a low consistency slurry is then mixed with ozone under high shear conditions. The ozone is then maintained in contact with the cellulosic fibers to effect bleaching of the fibers. The present process offers the advantages of bleaching using a low consistency slurry, with the added advantages of employing ozone.
    Type: Grant
    Filed: July 24, 2002
    Date of Patent: June 17, 2003
    Assignees: L'Air Liquide - Societe' Anonyme a' Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude, American Air Liquide LP
    Inventors: V. S. Meenakshi Sundaram, Derek Hornsey, Sebastien Corbeil
  • Patent number: 6576084
    Abstract: Chemical pulp is produced from a slurry of comminuted cellulosic fibrous material using a beneficial additive such as AQ, or polysulfide. In the first treatment zone the effective alkali concentration and temperature conditions are such so that substantially no alkali degradation of the cellulose occurs, but so that the material is effectively impregnated with the additive. Then the material is treated with an alkaline cooking liquor, at cooking temperature, to produce a chemical cellulose pulp with higher yield or strength than if the low temperature, low alkali, additive pretreatment was not practiced. Typical alkali and temperature conditions in the first zone are less than 10 g/l expressed as NaOH, and between about 80-130° C., e.g. about 80-110° C. The first zone is preferably a feed system (which may include a separate impregnation vessel) for a continuous digester, while cooking is in a continuous digester.
    Type: Grant
    Filed: September 12, 2000
    Date of Patent: June 10, 2003
    Assignee: Andritz Inc.
    Inventors: C. Bertil Stromberg, Joseph R. Phillips
  • Patent number: 6576086
    Abstract: Paper, board and cardboard are produced by draining paper stock containing interfering substances in the presence of fixing agents by a process in which the fixing agents used are reaction products which are obtainable by reacting amino- and/or ammonium-containing polymers selected from the group consisting of the polymers containing vinylamine units polyalkylene polyamines polyamidoamines ethyleneimine-grafted polyamidoamines which may be crosslinked, polydiallyldimethylammonium chlorides polymers containing dialkylaminoalkylacrylamide units or dialkylaminoalkylmethacrylamide units and polyallylamines and dicyandiamide and formaldehyde condensates with reactive sizes for paper in a weight ratio of polymer to reactive size of from 15,000:1 to 1:1, and the reaction products thus obtainable are used as fixing agents for water-soluble and for water-insoluble interfering substances in the production of paper, board and cardboard from paper stocks containing interfering substances.
    Type: Grant
    Filed: November 2, 1999
    Date of Patent: June 10, 2003
    Assignee: BASF Aktiengesellschaft
    Inventors: Roland Ettl, Hubert Meixner, Anton Esser, Rainer Scholz, Norbert Mahr, Ulrich Steuerle, Matthias Höne, Klaus Lorenz
  • Patent number: 6569284
    Abstract: The specification discloses an improved bleaching sequence which provides significant reduction in filtrate volumes and amounts of absorbable organic halide (AOX), color, and chemical oxygen demand (COD) in the effluent. These reductions are achieved without adversely affecting the brightness and viscosity properties of the bleached pulp and without a high capital cost and operating cost penalty or impact on existing mill processes. The bleaching sequence according to the invention for reducing filtrate volumes is an EOD1EOPD2 or EOPD1EOPD2 bleaching sequence wherein substantially all of the filtrates from the later bleaching stages are recycled to earlier bleaching stages and eventually treated in the initial EO or EOP stage prior to discharge from the plant.
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: May 27, 2003
    Assignee: International Paper Company
    Inventors: Caifang Yin, Jasper H. Field
  • Patent number: 6569286
    Abstract: Wood and non-wood pulp is bleached by: a) adding an aliquot of agglomerate from a bulk solids dispensing means, advantageously a hopper, to a dilute solution of hydrogen peroxide which is desirably agitated to keep the agglomerate in suspension, the agglomerate comprising: a bleach activator, advantageously tetraacetyl ethylene diamine (TAED); a peroxide soluble binder, preferably polyvinyl alcohol (PVOH); a dispersing system comprising a wetting agent which is a low foaming and does not discolour on exposure to temperatures of up to 120° C. and optionally a salt, preferably sodium acetate, which is highly soluble in hydrogen peroxide; and sequestrant which may additionally or alternatively be added directly to the hydrogen peroxide; b) allowing the TAED to substantially completely react with the hydrogen peroxide; c) adjusting the pH of the bleach solution by adding alkali, preferably caustic soda; and d) bleaching the pulp by contacting it with the bleaching solution under alkaline conditions.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: May 27, 2003
    Assignee: Warwick International Group Limited
    Inventors: John David Withenshaw, Jane Williams, Mark Ardern Chadwick, Neil Anthony Turner
  • Patent number: 6562191
    Abstract: A process based on formic acid cooking for producing pulp from herbaceous plants and deciduous trees by using acetic acid as an additional cooking chemical. The obtained pulp can be used in fine paper and board production as short-fibered material, for instance. The invention also relates to a process for adjusting the hemicellulose content of the pulp in connection with the formic acid cooking by using acetic acid as an additional cooking chemical.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: May 13, 2003
    Assignee: Chempolis Oy
    Inventors: Pasi Rousu, Päivi Rousu, Esa Rousu
  • Patent number: 6554958
    Abstract: A process for the delignification and bleaching of chemical paper pulps comprising one or more stage(s) of treatment with hydrogen peroxide, at a temperature greater than 100° C. and under high pressure, in the presence of a polymer and of a compound A chosen from potassium hydroxide, sodium hydroxide and alkali metal or alkaline-earth metal carbonates.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: April 29, 2003
    Assignee: Atofina
    Inventor: Michel Devic
  • Patent number: 6551451
    Abstract: A rapid method is provided for the on-line spectroscopic determination of lignin content and/or kappa number in wood pulps. Unlike currently available commercial instrumentation, the method enables one to measure lignin content independently of species variations and pulp consistency.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: April 22, 2003
    Assignee: Pulp and Paper Research Institute of Canada
    Inventors: Thanh P. Trung, Denys Leclerc
  • Patent number: 6547923
    Abstract: A method of bleaching cellulose pulp with ozone includes pumping cellulose pulp in form of a fiber suspension having a consistency range of 5 to 25% with a high-consistency pump to a fluidizing mixture in which oxygen and ozone containing gas is introduced and mixed into the pulp so as to generate a foam whereby the pulp fibers and the ozone used as the bleaching agent are brought to contact with each other, bleached, and the pulp is discharged from the mixer to a reaction vessel.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: April 15, 2003
    Assignee: Andritz Oy
    Inventors: Kaj Henricson, Torolf Laxen, Juhani Peltonen
  • Patent number: 6540872
    Abstract: Methods for bleaching chemical pulps are disclosed including a final bleaching sequence of bleaching with chlorine dioxide, treating with a chelating agent, in which the bleaching and treating steps are carried out in sequence without an intermediate washing step, washing the bleached pulp, and bleaching with hydrogen peroxide.
    Type: Grant
    Filed: February 25, 1997
    Date of Patent: April 1, 2003
    Assignee: Velmet Fibertech Aktiebolag
    Inventor: Mårten Dahl
  • Patent number: 6540870
    Abstract: The invention relates to papermaking processes wherein calcium carbonate is included in a pulp suspension. The dissolution of the calcium carbonate in the papermaking system is prevented or substantially retarded by the introduction of carbon dioxide to said pulp suspension in connection with subjecting said calcium carbonate in said papermaking system to pH conditions of about 8 or lower. The invention also provides processes for the production of paper or board in papermaking systems wherein solid calcium carbonate is present as a filler and/or pigment.
    Type: Grant
    Filed: January 3, 2000
    Date of Patent: April 1, 2003
    Assignees: AGA Aktiebolag, UPM-Kymmene Corp.
    Inventors: Auli Laurila-Lumme, Heikki Pakarinen, Hannu Juhani Leino
  • Patent number: 6533896
    Abstract: A method for preparing pulp from lignin-containing cellulosic material is disclosed, including a step for acid cleaning of the lignocellulosic material, followed by alkaline delignification. The acidic step removes undesired components such as metal ions and side groups of polysaccharides, which may have adverse effects on the process especially when extensive recycling of liquors is employed within the plant.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: March 18, 2003
    Assignee: Metso Chemical Pulping Oy
    Inventors: Panu Tikka, Mikael Svedman, Thomas Fant
  • Patent number: 6524442
    Abstract: An apparatus for fiberizing bales of pulp into substantially dry fibers and fiber aggregates. One embodiment includes: a bale support member for supporting a bale of pulp, the bale support member defining two openings; two rotatable fiberizing assemblies having disrupting elements protruding through the openings an adjustable distance above the bale support member to contact a surface layer of the bale of pulp, the surface layer having a dimension parallel to the longitudinal axis of the fiberizing assembly, a transportation assembly for moving the bale of pulp back and forth along the bale support member and over the openings so that the disrupting elements contact a surface layer in the bale, an adjustable reciprocating assembly permitting adjustment of the frequency by which the transportation assembly moves back and forth over the opening.
    Type: Grant
    Filed: December 26, 2000
    Date of Patent: February 25, 2003
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventors: James Jay Tanner, Harold Jay Koller
  • Patent number: 6524437
    Abstract: A process for peroxide bleaching of pulp using magnesium oxide or magnesium hydroxide as a substitute for caustic soda wherein the pulp is bleached in the presence of hydrogen peroxide characterized in that the concentration of ion present in the magnesium oxide or magnesium hydroxide and the pulp is maintained less than 20 ppm and/or the concentration of manganese is maintained less than 10 ppm.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: February 25, 2003
    Assignee: Orica Australia Pty. Ltd.
    Inventors: Adam Hayden Vincent, Ian Alexander McLean
  • Patent number: 6521084
    Abstract: In a process for extracting cellulose from fibrous materials such as wood, the fibrous materials are reacted with a chemical disintegration solution in the presence of organosilicic compounds.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: February 18, 2003
    Assignee: Wacker-Chemie GmbH
    Inventors: Willibald Burger, Outi Neubig, Kimmo Lappalainen, Hannu Wahlberg
  • Patent number: 6514380
    Abstract: Chemical pulp is produced by cooking comminuted cellulosic fibrous material (e.g. wood chips) in a continuous digester or batch digesters or produce brown stock, and washing the brown stock in a brown stock washer to produce chemical pulp, oxygen delignifying the chemical pulp at medium consistency, and then screening the oxygen delignified pulp to produce an accept fraction and a shive-containing reject fraction. Drawbacks inherent in the prior art are overcome by directly transporting (i.e. without refining or accessory oxygen delignification) the shive-containing rejects fraction to the main fiber line before oxygen delignification (e.g. to just before a mixer for the oxygen delignification stage, to between the brown stock washer and mixer, to a coarse screen between the digester and the brown stock washer, and/or to a washer for the coarse rejects from the coarse screen).
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: February 4, 2003
    Assignee: Andritz Oy
    Inventors: Antero Laine, Olavi Pikka