Chlorine Containing Patents (Class 162/87)
  • Patent number: 11643777
    Abstract: The present application relates to a method for preparing dissolving pulp by TCF bleaching of poplar KP, including: preparing poplar KP by pre-hydrolysis kraft process with poplar as a raw material, and OZQP bleaching of the poplar KP to obtain dissolving pulp, wherein O denotes oxygen delignification, Z denotes ozone bleaching, Q denotes chelating treatment, and P denotes hydrogen peroxide bleaching. The dissolving pulp prepared by the same exhibits that all indexes can meet the requirements of excellent products in dissolving pulp industry standard (QB/T4898-2015), and most of the indexes are far superior to those of excellent products, and thus it can completely replace imported dissolving pulp.
    Type: Grant
    Filed: August 26, 2020
    Date of Patent: May 9, 2023
    Assignee: Qilu University of Technology
    Inventors: Xingxiang Ji, Zhongjian Tian, Guihua Yang, Gaojin Lv, Wei Wei, Jiachuan Chen
  • Patent number: 9932709
    Abstract: Compositions and methods that preserve and enhance the brightness of pulp, and also improve the color of pulp or paper, when applied during different stages of a papermaking process, are disclosed. The compositions and methods maintain or enhance brightness, prevent yellowing, and enhance the performance of paper products. The compositions can include a mixture of reducing agents and can also include optical brighteners, chelants, polycarboxylates, or other additives. The mixture of reducing agents can include a borohydride, such as sodium borohydride, and any other reducing agent, such as a sulfite or bisulfite.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: April 3, 2018
    Assignee: ECOLAB USA INC.
    Inventors: Prasad Y. Duggirala, Sergey M. Shevchenko
  • Patent number: 8940133
    Abstract: An omnibus process of pulping and bleaching lignocellulosic materials in which a charge of a lignocellulosic material is biopulped and/or water extracted prior to pulping and bleaching. The lignocellulosic material may be mechanically pulped and bleached in the presence of an enzyme that breaks lignin-carbohydrate complexes. The aqueous extract in embodiments including a water extract step is separated into acetic acid and hemicellulose sugar aqueous solutions.
    Type: Grant
    Filed: March 6, 2014
    Date of Patent: January 27, 2015
    Assignee: The Research Foundation for The State University of New York
    Inventors: Thomas E. Amidon, Raymond Francis, Gary M. Scott, Jeremy Bartholomew, Bandaru V. Ramarao, Christopher D. Wood
  • Patent number: 8900408
    Abstract: Provided is a process for producing bleached pulp, including subjecting unbleached pulp, which is obtained by cooking a lignocellulose substance, to alkali-oxygen bleaching treatment and then subjecting the alkali-oxygen bleached pulp to chlorine-free bleaching treatment including chlorine dioxide treatment, wherein in at least one chlorine dioxide treatment stage in which the chlorine dioxide treatment is performed, monopersulfuric acid is used in combination. The amount of chlorine dioxide to be used is reduced and the color reversion resistance of the bleached pulp is improved by this process.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: December 2, 2014
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Kiyoshi Yoshida, Tetsuo Koshitsuka, Eiko Kuwabara, Takashi Ishii
  • Publication number: 20140318725
    Abstract: A bleached softwood kraft pulp fiber with high alpha cellulose content and increased brightness and whiteness is provided. Methods for making the kraft fiber and products made from it are also described.
    Type: Application
    Filed: May 18, 2012
    Publication date: October 30, 2014
    Applicant: GP CELLULOSE GMBH
    Inventors: Arthur J. Nonni, Charles E. Courchene, Philip R. Campbell, Steven C. Dowdle, Joel M. Engle, Christopher M. Slone
  • Publication number: 20140305603
    Abstract: A process for making pulp includes providing plant fiber raw material. The plant fiber raw material can be wood fiber or gramineae plant fiber. The plat fiber raw material is cooked to make a pulp. A TEMPO catalytic oxidation system is added to the pulp to oxidize the pulp fiber. The oxidized pulp fiber is then bleached.
    Type: Application
    Filed: December 12, 2013
    Publication date: October 16, 2014
    Applicant: Goldeast Paper (Jiangsu) Co., Ltd
    Inventors: PU MA, XIANG-FEI LIU, YUNGCHANG F. CHIN, REN-RONG WANG
  • Patent number: 8808500
    Abstract: Microbial growth in an aqueous system containing borohydride residues is controlled by adding an aldehyde or aldehyde source, followed by adding an active halogen biocide. The active halogen biocide is preferably stabilized by an N-hydrogen compound.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: August 19, 2014
    Assignee: Lonza Inc.
    Inventor: Kevin Janak
  • Patent number: 8568558
    Abstract: The delignification and bleaching of chemical pulp by a bleaching stage, in which the chemical pulp is reacted first with chlorine dioxide and, after reaction of the chlorine dioxide, is further reacted without intermediate washing with hydrogen peroxide in the presence of a molybdate or tungstate, permits the production of chemical pulp having a whiteness of at least 89.5%, having improved stability to yellowing and reduced oxidative damage.
    Type: Grant
    Filed: January 16, 2011
    Date of Patent: October 29, 2013
    Assignee: Evonik Degussa GmbH
    Inventor: Thomas Dietz
  • Publication number: 20130209573
    Abstract: Methods, kits, cartridges and compounds related to generating chlorine dioxide by exposing ClO2? to at least one of a manganese porphyrin catalyst or a manganese porphyrazine catalyst are described.
    Type: Application
    Filed: August 19, 2011
    Publication date: August 15, 2013
    Applicant: THE TRUSTEES OF PRINCETON UNIVERSITY
    Inventor: John T. Groves
  • Patent number: 8470132
    Abstract: Final chlorine dioxide bleaching of lignocellulosic materials is most effective at a near-neutral pH but present industrial practice typically targets a final pH of between 3.5 and 4.0 because of the difficulty in achieving and maintaining near-neutral pH cost effectively. The in situ formation of bicarbonate before the addition of chlorine dioxide provides a way of maintaining the required near-neutral pH. Near-neutral final chlorine dioxide bleaching also produces a bleached pulp that is in a state that responds more effectively to fluorescent whitening or optical brightening agents.
    Type: Grant
    Filed: February 12, 2007
    Date of Patent: June 25, 2013
    Assignee: FPInnovations
    Inventors: Zhi-Hua Jiang, Richard McKinnon Berry
  • Publication number: 20130102984
    Abstract: A method of producing a modified pulp for use in paper or paper web products, the method comprising treating wood chips in an extraction process to remove hemicellose to form treated wood chips; and subjecting said treated wood chips to chemical or semichemical pulping to form a modified Kraft pulp wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 5 to about 10% by dry weight of the modified pulp.
    Type: Application
    Filed: December 11, 2012
    Publication date: April 25, 2013
    Applicant: INTERNATIONAL PAPER COMPANY
    Inventor: International Paper Company
  • Patent number: 8317975
    Abstract: An omnibus process of pulping and bleaching lignocellulosic materials in which a charge of a lignocellulosic material is biopulped and/or water extracted prior to pulping and bleaching. The lignocellulosic material may be mechanically pulped and bleached in the presence of an enzyme that breaks lignin-carbohydrate complexes. The aqueous extract in embodiments including a water extract step is separated into acetic acid and hemicellulose sugar aqueous solutions.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: November 27, 2012
    Assignee: The Research Foundation of the State University of New York
    Inventors: Thomas E. Amidon, Raymond Francis, Gary M. Scott, Jeremy Bartholomew, Bandaru V. Ramarao, Christopher D. Wood
  • Patent number: 8287691
    Abstract: The disclosure provides a process of modifying a seed based fiber (SBF) to form an enhanced fiber additive (EFA). The process includes an acid treatment step and optionally at least one fiber modification step. Preferred EFA products and uses are described.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: October 16, 2012
    Assignee: Cargill, Incorporated
    Inventors: Jagannadh V. Satyavolu, David E. Garlie, Kevin R. Anderson, John T. McDonald, Paula R. Krogmann
  • Patent number: 8262856
    Abstract: Process for bleaching of pulps following cooking of the lignocellulosic material with soda and anthraquinone. The process may produce a whiteness on par with the bleaching of kraft pulp when using a similar bleaching sequence. In some instances, the bleaching sequence may be O-A-Do-Eop-D, O-A-ZDo-Eop-D, A-Do, or A-ZDo.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: September 11, 2012
    Assignee: Andritz Inc.
    Inventors: Pam O'Leary, Namhee Shin, C. Bertil Stromberg
  • Publication number: 20120031575
    Abstract: A method of treating lignocellulosic pulp in which an aqueous pulp mixture is treated with a bleaching agent and then subjected to an alkaline extraction at a reduced pH with a combination of alkaline agents comprising caustic soda and soda ash and using caustic soda for pH control.
    Type: Application
    Filed: April 27, 2011
    Publication date: February 9, 2012
    Applicants: SAVAGE SERVICES CORPORATION, FMC WYOMING CORPORATION
    Inventors: Bimal Khandelwal, Adrienne S. Nadeau, John T. Wolanski
  • Patent number: 8007636
    Abstract: The present invention relates to methods of modifying cellulose fibers and of producing paper which methods include providing a pulp suspension of cellulose fibers and adding a cellulose derivative during the bleaching of the cellulose fibers in an acidic bleaching stage.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: August 30, 2011
    Assignee: Akzo Nobel N.V.
    Inventors: Thomas Christopher Greschik, Jan Nordin, Hans-Ake Baltsen
  • Patent number: 7824556
    Abstract: Chlorous acid is generated from a chlorite salt precursor, a chlorate salt precursor, or a combination of both by ion exchange. The ion exchange material facilitates the generation of chlorous acid by simultaneously removing unwanted cations from solution and adding hydrogen ion to solution. Chlorine dioxide is generated in a controlled manner from chlorous acid by catalysis. Chlorine dioxide can be generated either subsequent to the generation of chlorous acid or simultaneously with the generation of chlorous acid. For catalysis of chlorous acid to chlorine dioxide, the chlorous acid may be generated by ion exchange or in a conventional manner. Ion exchange materials are also used to purify the chlorous acid and chlorine dioxide solutions, without causing degradation of said solutions, to exchange undesirable ions in the chlorous acid and chlorine dioxide solutions with desirable ions, such as stabilizing ions, and to adjust the pH of chlorous acid and chlorine dioxide solutions.
    Type: Grant
    Filed: October 18, 2005
    Date of Patent: November 2, 2010
    Inventors: Allison H. Sampson, Richard L. Sampson
  • Publication number: 20100263816
    Abstract: Steam stripper off gas from chemical pulp mills, for example kraft or sulphite pulp mills is rich in methanol and totally reduced sulphur (TRS) compounds. This gaseous stream is usually burned to avoid further handling of this TRS-rich, odorous stream. We found that once this gaseous stream is condensed, it can be used as a reducing agent in the chlorine dioxide generator, in place of purchased methanol. Surprisingly, we found that, in addition to the methanol component, the TRS components act as reducing agents during the production of chlorine dioxide or, at the very least, do not consume chlorine dioxide. The use of this stream in the ClO2 generator will allow pulp mills to reduce or eliminate the consumption of purchased methanol while providing a new approach to deal with TRS compounds in the chlorine dioxide generator rather than employing a dedicated TRS incinerator or any other combustion device.
    Type: Application
    Filed: November 12, 2008
    Publication date: October 21, 2010
    Inventors: Naceur Jemaa, Michael Paleogou, George Sacciadis, Richard M. Berry
  • Publication number: 20100252213
    Abstract: The present invention relates to a method of increasing the brightness of pulp, pulp made from such methods and methods of using such pulp.
    Type: Application
    Filed: November 19, 2009
    Publication date: October 7, 2010
    Applicant: INTERNATIONAL PAPER COMPANY
    Inventor: Xuan Troung Nguyen
  • Publication number: 20090264036
    Abstract: Provided is a nanofiber sheet that sufficiently refined by fibrillation and has high crystallinity of cellulose fiber and can realize a fiber-reinforced composite material exhibiting high transparency, a high elastic modulus, a low coefficient of linear thermal expansion, and high heat resistance and being high in flatness and smoothness. This nanofiber sheet includes crystalline cellulose as the main component and a lignin in an amount of from 10 ppm to 10 wt %. When a fiber/resin composite material obtained by impregnating the nanofiber sheet with tricyclodecane dimethacrylate, subjecting the impregnated product to UV-curing at 20 J/cm2, and heating the cured product in vacuum at 160° C. for two hours includes 60 wt % of the cured tricyclodecane dimethacrylate and 40 wt % of nanofiber, the following physical characteristics (i) to (iii) are satisfied: (i) the parallel light transmittance of light of a wavelength of 600 nm at a sheet thickness of 100 ?m is 70% or more; (ii) the Young's modulus is 5.
    Type: Application
    Filed: July 13, 2007
    Publication date: October 22, 2009
    Applicants: Nippon Telegraph and Telephone Corporation, Pioneer Corporation, Hitachi, Ltd., Mitsubishi Chemical Corporation, Rohm Co., Ltd.
    Inventors: Hiroyuki Yano, Masaya Nogi, Shinsuke Ifuku, Kentarou Abe, Keishin Handa
  • Patent number: 7585387
    Abstract: An oxidative solution (Ox-B, a solution of no less than 5:1 sodium hypochlorite: hydrogen peroxide) was found to remove both lignin and hemicellulose from sugarcane bagasse. After treatment the cellulosic residue readily separated from the lignin and hemicellulose by sedimentation. The residue (the pulp) contained up to 80% by weight cellulose, and was easily degradable by cellulase enzyme. A treatment of oxidation with low concentrations of Ox-B, followed by a caustic wash, produced a cellulose residue that was able to be almost completely hydrolyzed to simple sugars by cellulase. Due to the low amount chemical used and the efficiency of the degradation, this process has commercial potential.
    Type: Grant
    Filed: March 8, 2006
    Date of Patent: September 8, 2009
    Assignee: Board of Supervisors of Louisiana State University And Agricultural and Mechanical College
    Inventors: Donal F. Day, Chang-Ho Chung
  • Publication number: 20090145562
    Abstract: A process for bleaching mechanical wood pulp is provided comprising subjecting the wood pulp to at least one bleaching stage with one or more bleaching agents in the presence of one or more optical brightening agent, wherein the bleaching agents are selected from the group consisting of oxidative bleaching agents other than chlorine based bleaching agents such as chlorine dioxide, elemental chlorine or a combination thereof, reductive bleaching agents or any combination of two or more thereof.
    Type: Application
    Filed: November 26, 2008
    Publication date: June 11, 2009
    Inventor: Xuan Truong Nguyen
  • Publication number: 20090032208
    Abstract: Process for bleaching of pulps following cooking of the lignocellulosic material with soda and anthraquinone. The process may produce a whiteness on par with the bleaching of kraft pulp when using a similar bleaching sequence. In some instances, the bleaching sequence may be O-A-Do-Eop-D, O-A-ZDo-Eop-D, A-Do, or A-ZDO.
    Type: Application
    Filed: June 5, 2008
    Publication date: February 5, 2009
    Applicant: ANDRITZ INC.
    Inventors: Pam O'Leary, Namhee Shin, C. Bertil Stromberg
  • Patent number: 7377993
    Abstract: Methods for reducing, and in some cases eliminating, fluorescence in pulp and paper, as well as the resulting articles, are provided. The methods destroy fluorescent activity of agents (e.g., whitening agents) which may be present in the pulp during processing. The methods are particularly applicable to recycling processes that use paper that includes fluorescent whitening agents. The methods may be used to produce recycled pulp and paper that, for example, may be suitably used in food grade applications which require no, or minimal, amount of fluorescence. In some cases, the methods also advantageously enable production of recycled pulp and paper that has reduced amounts of phosphorescence.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: May 27, 2008
    Inventor: Tanya Smith Richardson
  • Publication number: 20080017337
    Abstract: Oxidative compositions and processes that preserve and enhance the brightness and improve color of pulp or paper when applied during different stages of the papermaking process are identified. The oxidative composition and method maintains and/or enhances brightness, prevents yellowing, and enhances the performance of paper products. Used in combination with optical brighteners and/or chelants the oxidative agents produce a synergistic effect not previously identified in the paper process.
    Type: Application
    Filed: July 21, 2006
    Publication date: January 24, 2008
    Inventors: Prasad Y. Duggirala, Sergey M. Shevchenko, Katherine M. Broadus
  • Patent number: 7264690
    Abstract: A catalyzer for clean pulping includes sodium salicylate, anion silicate softener, cooking aids, liquid(gaseous) chlorine and water. A process for using the catalyzer for clean pulping includes the following steps: 1, cutting and impurities removing for the raw material, 2, feed preparation and impurities removing, 3, dividing into fibers by refining, 4, catalysis copolymerization, 5, refining, 6, concentration and separation, 7, pulp bleaching, 8, pulp washing and 9, finished pulp. The present invention realizes the clean production; it does not need to digest and does not produce black liquor; the process is simple and is performed at normal temperature; the resource of crops is fully used; the effect of water conservation is remarkable; it is very easy to control each stage separately and/or simultaneously.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: September 4, 2007
    Inventor: Xiang Wu Cheng
  • Patent number: 6902649
    Abstract: The disclosure provides a process of modifying a seed based fiber (SBF) to form an enhanced fiber additive (EFA). The process includes an acid treatment step and optionally at least one fiber modification step. Preferred EFA products and uses are described.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: June 7, 2005
    Assignee: Cargill, Incorporated
    Inventors: Jagannadh V. Satyavolu, David E. Garlie, Kevin R. Anderson, John T. McDonald, Paula R. Krogmann
  • Patent number: 6777103
    Abstract: A fiber cement composite material providing improved rot resistance and durability, the composite material incorporating biocide treated fibrous pulps to resist microorganism attacks. The biocide treated fibers have biocides attached to inner and outer surfaces of individualized fibers to protect the fibers from fungi, bacteria, mold and algae attacks. The biocides selected have strong affinity to cellulose and do not interfere with cement hydration reactions. This invention also discloses the formulation, the method of manufacturing and the final fiber cement products using the biocide treated fibers.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: August 17, 2004
    Assignee: James Hardie Research Pty Limited
    Inventors: Donald J. Merkley, Caidian Luo
  • Publication number: 20040129394
    Abstract: This invention provides a process for treating chemical woodpulp, or chemical cellulose including cotton linter, including the step of applying an electron processing technology (EPT) step to chemical woodpulp, or chemical cellulose, as the case may be, on an in-line basis to provide control of pulp viscosity or degree of polymerisation (DP). The invention also provides a method of process control in treating the aforementioned woodpulp or cellulose, including the step of using radiation dose-viscosity relationship curve for applying an EPT step on an in-line basis. The in-line EPT step may, in one form of the invention, replace and hence eliminate a chemical DP reduction step.
    Type: Application
    Filed: February 20, 2004
    Publication date: July 8, 2004
    Inventors: Ian Graveson, Heinzhorst Mobius, Derek Andrew Weightman
  • Publication number: 20040084161
    Abstract: In a method for the production of fiber pulp for subsequent use in the production of a fiber web, especially a paper or cardboard web, the fiber pulp that was produced in a pulp production process is first loaded with an additive by way of a chemical precipitation reaction. The loaded pulp is then dried and available for subsequent utilization or formulated into a suitable form for shipment.
    Type: Application
    Filed: October 22, 2003
    Publication date: May 6, 2004
    Inventor: Helmut Heinzmann
  • Patent number: 6660128
    Abstract: A method for selectively delignifying lignocellulosic materials and bleaching of pulp and dyes using a combination of an oxidative enzyme and a metal complex. More specifically, the process involves the oxidation of a transition metal redox complex by a phenol oxidizing enzyme such as laccase or peroxidase to mediate the catalytic delignification of chemical pulp and bleaching of textile dye. This process is unique in that only a catalytic amount of metal complex mediator is required on softwood or hardwood kraft pulp, and that recycling or regeneration of the mediator for further pulp delignification is possible. The redox mediator is characterized in that it contains a transition metal ion coordinated with molecules or ions in such a way that the complexes have a formal redox potential between 0.5 and 1.2 volt measured against a normal hydrogen electrode.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: December 9, 2003
    Assignees: Pulp and Paper Research Institute of Canada, Universié de Montréal
    Inventors: Robert Bourbonnais, Dominic Rochefort, Michael G. Paice, Sylvie Renaud, Dónal Leech
  • Publication number: 20030168190
    Abstract: The invention relates to a process for the bleaching of an aqueous lignocellulosic pulp under acidic conditions in the bleaching plant of a pulp mill. The bleached pulp is used for the production of paper or pulp. The selectivity of the bleaching agent towards primary reactions with lignin is enhanced by the use of a carbon dioxide providing medium in the pulp.
    Type: Application
    Filed: March 26, 2003
    Publication date: September 11, 2003
    Inventors: Petri Juhana Jokinen, Jarmo Tapio Kahala, Hannu Sakari Sonni
  • Publication number: 20030155086
    Abstract: The invention relates to improvements in the bleaching of a lignocellulosic pulp by adding carbon dioxide to provide a beneficial pH profile in the chlorine dioxide bleaching or delignification. The resulting bleached pulp is used in the production of paper or pulp. The invention also relates to the use of carbon dioxide for providing a desired pH profile in a chlorine dioxide bleaching stage.
    Type: Application
    Filed: March 3, 2003
    Publication date: August 21, 2003
    Inventors: Krister Sjoblom, Malena Rennel
  • Publication number: 20030006017
    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: Application
    Filed: July 24, 2002
    Publication date: January 9, 2003
    Inventors: V.S. Meenakshi Sundaram, Derek Hornsey, Sebastien Corbeil, Steven A. Fisher
  • Patent number: 6398908
    Abstract: A process for delignification and bleaching of chemically digested lignocellulose-containing pulp. In a first embodiment, the pulp is acid treated at a pH of between about 1 and about 6, whereupon a water-soluble compound containing an alkaline earth metal is added at a pH of between about 1 and about 7 before the pulp is treated with a chlorine-free bleaching agent. In a second embodiment, the acid and alkaline earth metal treatments are carried out in a single step. The chlorine-free bleaching agent includes peroxide compounds, ozone, oxygen and sodium dithionite in an optional sequence or mixture. After the treatment according to the invention, the pulp may be finally bleached to the desired brightness, suitably with a chlorine-free bleaching agent, such as ozone, to completely avoid formation and discharge of AOX.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: June 4, 2002
    Assignee: Eka Nobel AB
    Inventors: Wenche Elisabeth Hermansson, Lennart Andersson, Magnus Linsten, Jiri Basta, Lillemor Holtinger
  • Publication number: 20010020521
    Abstract: In the treatment of cellulose pulp in connection with bleaching, the pulp is first cooked and, if necessary, oxygen delignified in order to reduce the Kappa number below 24, preferably below 14, and after that the pulp is treated in an acid stage at a pH of 2-5 and at a temperature range of 75-130° C. in order to reduce the Kappa number by 2-9 units. To prevent essential weakening of the strength properties of the pulp in the acid stage treatment tower, the retention time, t min, is 30 to 300 minutes and the treatment temperature, T° C.
    Type: Application
    Filed: February 27, 2001
    Publication date: September 13, 2001
    Applicant: Andritz-Ahlstrom Inc.
    Inventor: Kaj O. Henricson
  • Patent number: 6273994
    Abstract: The present invention relates to a device and method for measuring the bleach requirement and bleachability of pulp in a pulp mill. The invention enables pulp mill operators to better control bleach plants. In one aspect, the invention comprises a system and method for rapid bleaching of the pulp, and measuring the rapid bleached brightness and lignin content of the pulp. In another aspect, the invention comprises an optical system for use in practicing embodiments of this invention.
    Type: Grant
    Filed: January 30, 1998
    Date of Patent: August 14, 2001
    Assignee: Iogen Corporation
    Inventors: Brian Creber, Brian Foody, Patrick J. Foody, Jeffrey S. Tolan
  • Patent number: 6235154
    Abstract: A method which enhances the effectiveness of chlorine dioxide bleaching of lignocellulosic materials. It is effected by adding to the chlorine dioxide bleaching stage an aldehyde compound at a concentration of from about 0.01% to about 20%, by weight of the oven-dried lignocellulosic material.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: May 22, 2001
    Assignee: Pulp and Paper Research Institute of Canada
    Inventors: Zhi-Hua Jiang, Barbara van Lierop, Richard McK. Berry
  • Patent number: 6228213
    Abstract: This process involves feeding cellulose into an extruder with an acid solution. The extruder is comprised of a screw and a barrel. The screw is rotated so as to pressurize the cellulose, and the cellulose undergoes acid hydrolysis and forms microcrystalline cellulose. The invented process can be accomplished by using pure cellulose or a lignocellulosic material as the starting material. If a lignocellulosic material is used, then a basic solution is added to it and the lignocellulosic material is fed through an extruder so as to obtain a mixture comprising lignin, hemicellulose and cellulose. The lignin and hemicellulose are extracted and the remaining cellulose is processed, as discussed previously, to form microcrystalline cellulose.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: May 8, 2001
    Assignee: University of Nebraska-Lincoln
    Inventors: Milford Hanna, Gerald Biby, Vesselin Miladinov
  • Patent number: 5900113
    Abstract: The present invention provides a method of monitoring a papermaking system and unit operations contained therein to optimize the overall papermaking process. The method comprises employing a fluorescent tracer that is selectively carried through the entire papermaking system or in a specific unit operation and is sufficiently inert and sufficiently stable under the environmental and chemical conditions of the system from its addition point to the sampling point. A sample is withdrawn from the papermaking environment (either via `grab` or on-line side stream sampling) and the withdrawn sample subjected to analysis. The analysis comprises comparing the tracer concentration to a standard to determine the concentration of tracer in the sample and/or determining the time of first appearance of said tracer from addition point to the sampling point and/or subsequent decay of said tracer concentration at the sampling point.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: May 4, 1999
    Assignee: Nalco Chemical Company
    Inventor: Karen R. Tubergen
  • Patent number: 5662773
    Abstract: The present invention discloses a process for treating filter rods comprising cellulose acetate tow waste comprising the steps of:a. cutting said filter rods so that fiber of said cellulose acetate have a fiber length of less than about 4 inches; andb. treating said cut filter rods with an aqueous base until at least 5% of acetyl groups on said cellulose acetate has been hydrolyzed.Filter rods treated in this manner are suitable for use in various paper products. The process of the present invention may further include a step for repulping the cut filter rods to repulp any included plugwrap.Modified fiber comprising cellulose acetate wherein at least 5% of acetyl groups on said cellulose acetate have been hydrolyzed, said fiber having a length of less than about 4 inches, are also disclosed.Paper products comprising between about 5 and about 90% of the fiber of claim 21 and paper pulp are also disclosed.
    Type: Grant
    Filed: January 19, 1995
    Date of Patent: September 2, 1997
    Assignee: Eastman Chemical Company
    Inventors: Tim J. Frederick, Melvin G. Mitchell, Lee R. Partin
  • Patent number: 5618385
    Abstract: Chlorine dioxide is used to stabilize hydrogen peroxide in bleach liquor at alkaline pH. This is thought to be aided by the destruction of enzymes (especially catalase) produced by bacteria. The method is useful for the reprocessing of pulps, especially when a de-inking stage is involved.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: April 8, 1997
    Assignee: Albright & Wilson Limited
    Inventors: Trevor E. Jones, Stephen Crelling, Robert E. Talbot
  • Patent number: 5574088
    Abstract: A composition for increasing the resistance of polyamide fibers or polyester fibers to oxidizing agents comprising an organosiloxane modified with amino groups, melamine formaldehyde resin, a catalyst for complexing the melamine formaldehyde resin and water. The composition is used by applying it to the fibers so the fibers absorb the composition, and then drying and curing the composition on the fibers. The composition is employed to treat a polyester or polyamide felt employed to convey wood pulp which is to be bleached, prior to paper making operations, treatment of the felt with the composition significantly lengthens the useful life of the felt, exposed to bleaching chemicals.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: November 12, 1996
    Assignee: Tichromatic Carpet Inc.
    Inventor: Yassin Elgarhy
  • Patent number: 5554535
    Abstract: The white rot fungus Scytinostroma galactinum strain F361 and mutants thereof are particularly effective in selectively grading the lignin component of lignin-containing materials, particularly processed wood pulps including chemical pulps, and also particularly effective in degrading lignin degradation products such as chlorinated degraded lignin by-products as found, for example, in E-1 effluents, and also in degrading chlorine-containing aromatic compounds generally as found in aqueous waste streams containing the same.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: September 10, 1996
    Assignee: Clariant Finance (BVI) Limited
    Inventors: Robert A. Blanchette, Theresa S. Brush, Roberta L. Farrell, Keith A. Krisa, Chittra Mishra
  • Patent number: 5358864
    Abstract: Methods and expression constructs are provided for the cloning and overexpression of xylanases of fungai origin in a selected microbial host cell. Xylanases of fungal origin generally have lower pH optima and remain stable over a broader pH range than do xylanases of bacterial origin. The present invention provides for the high level production of fungal xylanases which are may be used in a variety of industrial applications requiring xylanase activity at a low pH.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: October 25, 1994
    Assignee: Gist-Brocades, N.V.
    Inventors: Henriette C. van den Broeck, Leendert H. de Graaff, Jan D. R. Hille, Albert J. J. van Ooyen, Jacob Visser, Abraham Harder
  • Patent number: 5330620
    Abstract: A process for bleaching pulp which employs chloric acid as the oxidizing agent, in the absence of a transition metal catalyst.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: July 19, 1994
    Assignee: Pulp and Paper Research Institute of Canada
    Inventors: Richard M. Berry, Michael Paleologou, Norman Liebergott
  • Patent number: 5273625
    Abstract: Method for treating chemically treated cellulosic pulp that contains sodium ions wherein the pulp is subjected to an ion exchange with a cation (preferably calcium) having a higher valence than the sodium followed by washing of the sodium cations from the pulp and then forming the pulp containing the cations in an amount equivalent to at least 700 ppm of calcium ions into a sheet thereby to facilitate water removal and increase the production rate of the sheet forming machine.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: December 28, 1993
    Assignee: MacMillan Bloedel Limited
    Inventor: Edi Antolovich
  • Patent number: 5139613
    Abstract: A process for souring chemical or mechanical cellulosic pulp using carbon dioxide to obtain proper acidification of the pulp slurry. The souring is performed after a single or a multistage bleaching sequence ending with sodium hypochlorite, calcium hypochlorite or hydrogen peroxide or the like in a common process for the preparation of paper pulp. The use of CO.sub.2 permits bleaching to continue because CO.sub.2 does not destroy the bleaching residuals remaining from the single or last bleaching stages.
    Type: Grant
    Filed: January 21, 1988
    Date of Patent: August 18, 1992
    Assignee: Canadian Liquid Air Limited
    Inventor: Raymond C. Lachapelle
  • Patent number: 5013404
    Abstract: A process for alkaline hydrogen peroxide bleaching of mechanical wood pulp which employs a quaternary amine compound, such as (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride, in the stabilized bleach solution. The brightness of the final paper product made from such bleached pulp shows marked improvement over that in which only chelating agents are employed to improve the brightness according to the known art. The process is useful in both silicate and silicate-free bleach solutions.
    Type: Grant
    Filed: November 15, 1989
    Date of Patent: May 7, 1991
    Assignee: The Dow Chemical Company
    Inventors: Steven H. Christiansen, Teresa Littleton, Robert T. Patton
  • Patent number: 4956048
    Abstract: In the method of chemical pulping of wood including a chlorination stage pulp bleaching step followed by alkaline extraction, a method of reducing the amount of dioxins and furans produced thereby is disclosed wherein the brownstock pulp is first washed with alcohol prior to bleaching.
    Type: Grant
    Filed: April 17, 1989
    Date of Patent: September 11, 1990
    Assignee: Westvaco Corporation
    Inventor: Ronnie G. Hise