Abstract: A process of treating a lignocellulosic material includes a pre-extraction step in which hemicellulose is extracted from the lignocellulosic material. In one embodiment, the pre-extraction step involves contacting the lignocellulosic material with an aqueous solution under conditions that release acidic material from the lignocellulosic material into the aqueous solution, and the aqueous solution includes a basic material that at least partly neutralizes the acidic material so that the aqueous solution at the end of the pre-extraction step has a pH within a range of from 4.5 to 11. The process also includes a pulping step, after the pre-extraction step, in which the lignocellulosic material is separated into pulp. The process further includes an adsorption step, after the pulping step, in which hemicellulose is adsorbed on the pulp.
Type:
Application
Filed:
December 18, 2006
Publication date:
June 19, 2008
Inventors:
Adriaan Reinhard Pieter van Heiningen, Sung-Hoon Yoon, Haixuan Zou, Jianer Jiang, Gopal C. Goyal
Abstract: The method is for bleaching cellulose pulp in a bleach line that has at least two bleaching steps. The filtrate distribution is led up through the bleaching line counter-currently to the flow of cellulose pulp established in the bleaching line. A single joint main conduit is used for the bleaching steps. Wash filtrates obtained from the wash steps, used after or before the bleaching step, are led in conduits to branch locations on the main conduit that are positioned downstream of the branch location for drawing off of wash and/or dilution liquor for the wash step in question. All branch points in the joint main conduit are in fluid communication with one another along the main conduit.
Abstract: The present invention relates to a process for oxidising a hydroxyl group to form an aldehyde and/or carboxy group, the process comprising the step of reacting a substrate comprising at least one primary hydroxy group with a nitrosonium ion in the presence of an oxidase and hydrogen peroxide.
Type:
Application
Filed:
August 9, 2005
Publication date:
May 8, 2008
Applicant:
NEDERLANDSE ORGANISATIE VOOR TOEGEPAST-NATUURWETEN
Abstract: A method for bleaching cellulosic pulp is disclosed, with one embodiment revealing a three-step bleaching method for cellulosic pulp comprising an activating bleach step, an alkaline peroxide step, and a reductive bleach step. The cellulosic pulp treated according to the present invention may possess a greater GE brightness gain than if treated according to conventional methods, while not suffering a significant loss of lignin. The cellulosic pulp may comprise recycled fibers, including those with high groundwood content. The bleaching method may also decrease the pH of the pulp.
Type:
Application
Filed:
October 11, 2006
Publication date:
April 17, 2008
Applicant:
Fort James Corporation
Inventors:
Jeffrey A. Lee, Stephanie A. Keen, H. Charles Thomas, Daniel W. Sumnicht
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
Abstract: In general, the present disclosure is directed to compositions and processes to increase pulp yield, reduce extractives, and reduce scaling in a chemical pulping process. In one particular embodiment, for instance, the present disclosure is directed to a composition comprising a surface active agent, an alkaline mixture, at least one polymer, the polymer having a linear backbone segment having two ends, at least one phosphorus component, the phosphorus component chemically linked along the linear backbone segment of the polymer, and at least one end component, the end component chemically linked to one or both ends of the linear backbone segment of the polymer.
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.
Abstract: The present invention relates to a biopulping method, and more particularly to a biopulping method for non-woody fiber plants. A biopulping method for a non-woody fiber plant is provided. It includes steps of providing a culture solution, adding a non-woody fiber plant to the culture solution, adding a microorganism suspension to the culture solution, fermentatively culturing the culture solution for preparing a pulp solution, boiling the pulp solution, pulping the pulp solution, and screening the pulp solution for isolating the paper pulp from the pulp solution.
Abstract: A pulp product that has a low COD is comprised of an unbleached pulp that is soaked and washed in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 3.0 kg/1000 kg of dry pulp. The pulp is produced by repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. The pulp is soaked and washed for a total of at least 400 minutes at an elevated temperature to produce the pulp product that has a low COD.
Type:
Grant
Filed:
July 30, 2002
Date of Patent:
June 5, 2007
Assignee:
Weyehaeuser Company
Inventors:
Michael D. Vrbanac, Brian Wester, Brian E. Dennis, Peter K. Lau, Julie A. Reimer, David W. Bickell
Abstract: The method is for bleaching cellulose pulp in a bleach line that has at least two bleaching steps. The filtrate distribution is led up through the bleaching line counter-currently to the flow of cellulose pulp established in the bleaching line. A single joint main conduit is used for the bleaching steps. Wash filtrates obtained from the wash steps, used after or before the bleaching step, are led in conduits to branch locations on the train conduit that are positioned downstream of the branch location for drawing off of wash and/or dilution liquor for the wash step in question. All branch points in the joint main conduit are in fluid communication with one another along the main conduit.
Abstract: The present invention relates to an environment friendly, safe, and efficient four-step method of bio-bleaching Kraft pulp using bacterial strains of accession no. MTCC 5096, MTCC 5094, MTCC 5095, and MTCC 5098, a microbial consortium comprising a synergistic mixture of ligninolytic bacterial isolates of accession no. MTCC 5094, MTCC 5095, and MTCC 5098, bacterial strains of accession Nos. MTCC 5096, MTCC 5094, MTCC 5095, and MTCC 5098, and a process of preparing an inoculum of the bacterial isolate of accession no. MTCC 5096, further, a process for the preparation of a consortium comprising the ligninolytic bacterial isolates of accession nos. MTCC 5094, MTCC 5095, and MTCC 5098, in addition, a process for the preparation of pulp suspension for the bio-bleaching.
Type:
Grant
Filed:
March 21, 2003
Date of Patent:
March 28, 2006
Assignee:
Council of Scientific and Industrial Research
Abstract: In accordance with the present invention, lyocell products can be made with unbleached pulps resulting in products with high amounts of hemicellulose and high amounts of lignin as compared to conventional lyocell products. The lyocell products of the present invention are advantageously less expensive to produce but retain the desirable strength of conventional lyocell products.
Abstract: The use of low specific gravity wood from thinning operations, for example, will produce a lower brownstock viscosity for a given kappa number target. A differential of 200-cP falling ball pulp viscosity has been detected from Kraft cooks of low and high specific gravity wood. Using low specific gravity wood can reduce the bleach stage temperature and the chemical dose needed in the bleach plant to produce lyocell pulp specifications. Low specific gravity wood also increases the ability to reduce pulp viscosity to very low levels without increasing the copper number of the pulp or the concentration of carbonyl in the pulp above acceptable levels.
Type:
Grant
Filed:
January 2, 2003
Date of Patent:
September 28, 2004
Assignee:
Weyerhaeuser Company
Inventors:
James E. Sealey, II, W. Harvey Persinger, Jr., Kent Robarge, Mengkui Luo
Abstract: In accordance with the present invention, lyocell products can be made with unbleached pulps resulting in products with high amounts of hemicellulose and high amounts of lignin as compared to conventional lyocell products. The lyocell products of the present invention are advantageously less expensive to produce but retain the desirable strength of conventional lyocell products.
Abstract: A method for the bleaching and brightness stabilization of lignocellulosic materials is described. The method involves the treatment of lignocellulosic materials, in particular, (a) wood pulps such as thermomechanical pulps (TMP) and chemithermomechanical pulps (CTMP), and (b) papers made from wood pulps, with a water-soluble phosphine or a phosphonium compound preferably containing at least one phosphorus hydroxyalkyl bond/linkage, for example a phosphorus hydroxymethyl bond/linkage (P—CH2OH). One example of such a water-soluble phosphine is the commercially available, tris(hydroxymethyl)phosphine (THP), P(CH2OH)3. One example of such a phosphonium compound is the commercially available, tetrakis(hydroxymethyl)phosphonium chloride (THPC), [P(CH2OH)4]Cl.
Type:
Application
Filed:
February 4, 2004
Publication date:
September 9, 2004
Inventors:
Thomas Qiuxiong Hu, Brian R. James, Dominggus Yawalata, Maria B. Ezhova
Abstract: The present invention relates to a method of treating chemical pulp in order to optimize the consumption of bleaching chemicals and to improve the quality of the pulp. Especially the invention relates to a method according to which filtrate obtained from a suitable stage of the washing of brown stock preferably cooked by an alkaline cooking method is treated with an oxidizing chemical prior to the oxygen stage following the brown stock washing.
Type:
Grant
Filed:
May 15, 2001
Date of Patent:
May 11, 2004
Assignee:
Andritz Oy
Inventors:
Kaj Henricson, Eero Kontturi, Olavi Pikka, Janne Vehmaa
Abstract: A method to enhance brightness in Chemical and Mechanical bleached pulps comprising adding an organic sulfide chelant to the Chemical and Mechanical pulp.
Type:
Grant
Filed:
May 1, 2001
Date of Patent:
March 9, 2004
Assignee:
Ondeo Nalco Company
Inventors:
Prasad Y. Duggirala, Sergey M. Shevchenko, Kristine S. Salmen
Abstract: This invention relates to an improved process for manufacturing bleached thermomechanical aspen pulp having reduced yellow after treatment with aluminum based chemicals such as alum which are used in paper making processes. In this improved process the pulp is washed prior to, after or between the bleaching stages or a combination of the foregoing.
Type:
Application
Filed:
August 31, 2002
Publication date:
March 4, 2004
Inventors:
Robin R. Kilgannon, Robert J. Kane, Eileen M. Joy, Anil K. Dewan
Abstract: A method is provided for bleaching a non-cotton cellulosic fiber, yarn or fabric by contacting said fiber, yarn or fabric with a hemicellulase enzyme for a time and under conditions suitable to produce a whitening of said fiber, yarn or fabric.
Type:
Grant
Filed:
April 4, 2000
Date of Patent:
February 3, 2004
Assignee:
Genencor International, Inc.
Inventors:
Anthony G. Day, Scott D. Power, Doreen Victoria, Deborah S. Winetzky
Abstract: Stabilized bromine solutions are prepared by combining a bromine source and a stabilizer to form a mixture, and then adding an oxidizer to the mixture.
Type:
Grant
Filed:
August 1, 2001
Date of Patent:
December 30, 2003
Assignee:
Ondeo Nalco Company
Inventors:
Shunong Yang, Donald A. Johnson, Robert L. Wetegrove, George J. Collias
Abstract: An anionic cellulose ether obtainable by a process comprising reacting an alkali metal cellulose with one or more reagents A selected from the group consisting of haloacetic acids, alkali metal haloacetates, alkali metal vinyl sulfonates, vinyl sulfonic acid, and precursors thereof, and one or more reagents B having the formula R1—(OCH2CH(R2))n-P, wherein R2 represents hydrogen or a methyl group; n is 0-2; P represents a glycidyl ether group, a 1,2-epoxy group or a precursor thereof, if P represents a glycidyl ether group, R1 represents a linear C3-C5 alkyl group, optionally containing an oxygen atom, a phenyl group, or a benzyl group, and if P represents a 1,2-epoxy group, R1 represents a linear C3-C5 alkyl group, optionally containing an oxygen atom. Preferably, reagent A is chloroacetic acid and reagent B is n-butyl glycidyl ether. The invention also relates to the use of said anionic cellulose ether as an associative thickener, rheology modifier or stabilizer.
Abstract: The use of fatty acid oxidizing enzymes in the manufacture of paper materials, such as paper, linerboard, corrugated paperboard, tissue, towels, corrugated containers and boxes. Examples of fatty acid oxidizing enzymes are oxygenases classified as EC 1.13.11. including any of the sub-classes thereof, such as lipoxygenase, EC 1.13.11.12. The effect of these enzymes is that the deposition of pitch is reduced, and bleaching and de-inking effects are also observed on the paper pulp and the resulting paper material. The fatty acid oxidizing enzyme can be used in combination with a substrate, with proteases, lipases, xylanases, cutinases, oxidoreductases, cellulases, endoglucanases amylases, mannanases, steryl esterases, and/or cholesterol esterases; or with surfactants and other adjuvants.
Type:
Application
Filed:
October 18, 2002
Publication date:
July 3, 2003
Applicant:
Novozymes A/S
Inventors:
Kim Borch, Neal Franks, Henrik Lund, Hui Xu, Jing Luo
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
Abstract: Pulps or papers, especially chemimechanical or thermomechanical pulps or papers, which still contain lignin, have enhanced resistance to yellowing when they contain an effective stabilizing amount of a hindered amine compound which preferably is a nitroxide, a hydroxylamine or an ammonium salt thereof. This performance is often further enhanced by the presence of one or more coadditives selected from the group consisting of the UV absorbers, the polymeric inhibitors, the nitrones, the fluorescent whitening agents, metal chelating agents, sulfur containing stabilizers, metal salts and diene compounds. Combinations of nitroxides, hydroxylamines or their salts, benzotriazole or benzophenone UV absorbers and a metal chelating agent are particularly effective. Selected derivatives of 1-oxyl-2,2,6,6-tetramethyl-piperidin-4-ol and selected hydroxylamine salts are novel compounds and are surprisingly effective for this purpose.
Type:
Grant
Filed:
May 18, 2000
Date of Patent:
December 31, 2002
Assignee:
Ciba Specialty Chemicals Corporation
Inventors:
Raymond R. Seltzer, Jean-Pierre Wolf, Cyril Heitner, John A. Schmidt, Peter F. McGarry, Glen T. Cunkle, Randall B. Nelson
Abstract: Pulps or papers, especially chemimechanical or thermomechanical pulps or papers, which still contain lignin, have enhanced resistance to yellowing when they contain an effective stabilizing amount of a hindered amine compound which preferably is a nitroxide, a hydroxylamine or an ammonium salt thereof. This performance is often further enhanced by the presence of one or more coadditives selected from the group consisting of the UV absorbers, the polymeric inhibitors, the nitrones, the fluorescent whitening agents, metal chelating agents, sulfur containing stabilizers, metal salts and diene compounds. Combinations of nitroxides, hydroxylamines or their salts, benzotriazole or benzophenone UV absorbers and a metal chelating agent are particularly effective. Selected derivatives of 1-oxyl-2,2,6,6-tetramethylpiperidin-4-ol and selected hydroxylamine salts are novel compounds and are surprisingly effective for this purpose.
Type:
Grant
Filed:
October 10, 2001
Date of Patent:
September 10, 2002
Assignee:
Ciba Specialty Chemicals Corporation
Inventors:
Raymond R. Seltzer, Jean-Pierre Wolf, Cyril Heitner, John A. Schmidt, Peter F. McGarry, Glen T. Cunkle, Randall B. Nelson
Abstract: The present inventors have discovered that the solution rheology of cellulose ethers prepared from cellulose pulp is altered by mercerizing and recovering cellulose pulp before preparing the cellulose ethers. For example, the solution viscosity of carboxymethyl cellulose (CMC) produced from mercerized and recovered cellulose pulp is significantly greater than that produced from non-mercerized cellulose pulp. The present invention provides a method of preparing cellulose ethers comprising the steps of (a) obtaining mercerized and recovered cellulose pulp, and (b) converting the mercerized and recovered cellulose pulp into the cellulose ethers. According to one embodiment, the cellulose pulp is southern softwood kraft and the mercerized cellulose pulp has a TAPPI 230 om-89 viscosity of at most 12 cP. This method, however, may be applied to all cellulose pulps, regardless of their viscosities, including those which, when mercerized, have a viscosity greater than 12 cP.
Type:
Application
Filed:
October 31, 2001
Publication date:
August 1, 2002
Applicant:
BKI HOLDING CORPORATION
Inventors:
Roger Bruce Harding, Susan L. H. Crenshaw, Paul Eugene Gregory, Denise Hartnett Broughton
Abstract: A method of treating solid containing material derived from effluent or sludge from a plant for de-inking paper, the material containing calcium in the form of one or more insoluble calcium compounds, the method including the steps of treating the material with an acid to cause dissolution of the calcium thereby forming a calcium ion-containing solution in which insoluble solids are suspended, separating the solution from the insoluble solids and incinerating the separated solids. The solution containing calcium ions may be treated by adding one or more reagents to form a calcium compound precipitate, eg calcium carbonate. The particulate solids produced following the incineration step and following the precipitate formation may be employed as pigments or fillers in paper making or paper coating.
Abstract: The invention concerns a method for producing a paper web. According to the method a stock is produced from the fibrous raw material and the stock is formed to a web which is dried on a paper machine. According to the invention the stock is formed from a mechanical pulp prepared from wood material of the Populus family and from bleached chemical spruce pulp, whereby the amount of the mechanical pulp is 20 to 70 weight-% and the amount of the bleached chemical softwood pulp is 80 to 30 weight-% of the dry matter of the stock. It is preferred to use an aspen pulp, over 70% of the fiber fractions of which comprise fiber fractions +100, +200 and −200, and the proportion of the −200 fraction is 45% or less. A coated fine paper can be produced from the paper web whose properties are better than those of a traditional fine paper having the corresponding bulk and grammage, on the same capacity level the paper produced by the invention will give a yield gain of up to more than 20%.
Type:
Grant
Filed:
September 16, 1998
Date of Patent:
May 21, 2002
Assignee:
M-real Oyj
Inventors:
Stina Nygård, Markku Leskelä, Maija Pitkänen
Abstract: A method for the shrink-proof treatment of a cellulosic fiber textile comprising the steps of treating a cellulosic fiber textile with liquid ammonia and subsequently treating it with steam.
Abstract: A paper bulking promoter containing a compound represented by the following formula (1) with which a highly bulky sheet can be obtained without impairing paper strength:
RO(EO)m(PO)nH (1)
wherein R represents a linear or branched alkyl or alkenyl group having 6 to 22 carbon atoms or an alkylaryl group in which the alkyl group has 4 to 20 carbon atoms; E represents an ethylene group; P represents a propylene group; m indicates the average number of moles added in the range of 0≦m≦20; and n is a number in the range of 0≦n≦50; provided that the EO and PO groups may have any of block and random arrangements and may begin with any of EO and PO.
Type:
Grant
Filed:
November 25, 1998
Date of Patent:
August 14, 2001
Assignee:
Kao Corporation
Inventors:
Yasushi Ikeda, Hiromichi Takahashi, Toshiki Sowa, Koji Hamaguchi
Abstract: Pulps or papers, especially chemimechanical or thermomechanical pulps or papers, which still contain lignin, have enhanced resistance to yellowing when they contain an effective stabilizing amount of a hindered amine compound which preferably is a nitroxide, a hydroxylamine or an ammonium salt thereof. This performance is often further enhanced by the presence of one or more coadditives selected from the group consisting of the UV absorbers, the polymeric inhibitors, the nitrones, the fluorescent whitening agents, metal chelating agents, sulfur containing stabilizers, metal salts and diene compounds. Combinations of nitroxides, hydroxylamines or their salts, benzotriazole or benzophenone UV absorbers and a metal chelating agent are particularly effective. Selected derivatives of 1-oxyl-2,2,6,6-tetramethyl-piperidin-4-ol and selected hydroxylamine salts are novel compounds and are surprisingly effective for this purpose.
Type:
Grant
Filed:
July 20, 1998
Date of Patent:
July 3, 2001
Assignee:
Ciba Specialty Chemicals Corporation
Inventors:
Raymond R. Seltzer, Jean-Pierre Wolf, Cyril Heitner, John A. Schmidt, Peter F. McGarry, Glen T. Cunkle, Randall B. Nelson
Abstract: Cellulose microfibrils, in particular for use as a reinforcing filler or structuring agent in composite materials, a method for making same, and composite materials containing said microfibrils, are disclosed. Specifically, said microfibrils are surface-modified cellulose microfibrils with an L/D ratio higher than 20, preferably higher than 100, and an average diameter of 1-50 nm, where L is the length of the microfibril and D is its average diameter. At least 25% by number of the hydroxyl functions on the surface of the microfibrils are esterified by at least one organic compound including at least one function capable of reacting with the hydroxyl groups of the cellulose. As a result, when the organic compound is a compound that includes acetyl groups such as acetic acid, said microfibrils are used as a reinforcing filler in a material comprising cellulose acetate as the polymeric matrix. The filled composite material may be shaped to provide films, moldings, fibers or yarns.
Type:
Grant
Filed:
July 9, 1998
Date of Patent:
September 12, 2000
Assignee:
Rhodia Chimie
Inventors:
Jean-Yves Cavaille, Henri Chanzy, Etienne Fleury, Jean-Fran.cedilla.ois Sassi
Abstract: A method for adjusting the alkalinity of a pulp slurry in a broke pulper, and more particularly, to adjusting the pH of the pulp slurry using carbon dioxide.
Type:
Grant
Filed:
October 24, 1997
Date of Patent:
July 11, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
David John Plaskon, Richard Joseph Piazza
Abstract: A process is disclosed for bleaching of a substrate which includes adding a molecular oxygen activating system to an aqueous wash liquor and bleaching the substrate with the molecular oxygen activating system in the aqueous wash liquor. Significant substrate cleaning results can be obtained by molecular oxygen obtained from air even in the absence of any usually applied active oxygen ingredients such as perborate or percarbonate.
Abstract: A purified novel cellulase composition is provided which may be isolated from a fermentation culture of Trichoderma longibrachiatum and has a molecular weight of about 95-105 kD as approximated on SDS-PAGE (see FIG. 1), a pl of about 5.6-6.8 as estimated on an IEF gel and a pH optimum of about 5.0 on RBB-CMC when measured at 65.degree. C. and pH 4 or lower at temperatures of 40.degree. C. and 50.degree. C.
Type:
Grant
Filed:
October 9, 1996
Date of Patent:
January 25, 2000
Assignee:
Genencor International, Inc.
Inventors:
Benjamin S. Bower, Kathleen A. Clarkson, Katherine D. Collier, James T. Kellis, Moira B. Kelly, Edmund A. Larenas
Abstract: A process for dissolving a binder off a fiber web bonded therewith includes treating the fiber web, which is bonded with a polymeric binder having carboxylate groups crosslinked via alkaline earth metal cations, with an aqueous solution of an alkali metal salt to form a sparingly soluble salt or complex between the anion of the alkali metal salt and the alkaline earth metal cations, and then removing the fiber freed of the binder.
Type:
Grant
Filed:
May 6, 1997
Date of Patent:
December 21, 1999
Assignee:
BASF Aktiengesellschaft
Inventors:
Karl-Heinz Schumacher, Rainer Hummerich, Howard Peter Kirsch
Abstract: Enzyme compositions containing thermostabile xylanases of Chaetomium thermophilum, purified enzyme preparations of such xylanases, and the use of such compositions and preparations in the bleaching of plant pulp and in feed and baking applications are described.
Type:
Grant
Filed:
December 17, 1996
Date of Patent:
July 13, 1999
Assignee:
Rohm Enzyme Finland OY
Inventors:
Richard B. Fagerstrom, Marja Paloheimo, Raija Lantto, Tarja Lahtinen, Pirkko Suominen
Abstract: This invention relates to an environmentally preferred process for the delignification of a cellulosic biomass comprising pulp. The process uses the oxidative properties of nascent oxygen to complete pulping and bleaching operations. The process may be used in a pulping stage, a bleaching stage or can be used for both the pulping and bleaching stages of a delignification process. The process does not rely on large volumes of environmentally offensive chemicals such as caustic soda, sulfur, and chlorine to achieve delignification of the pulp.
Abstract: A process for the bleaching of kraft pulps with non-chlorine chemicals, employing a sequential reaction of oxidative enzymes and hydrogen peroxide. The kraft pulp can be from conventional or extended pulping, or from an oxygen delignification step. The enzyme reaction is monitored by methanol release which results from the demethylation of lignin. The process essentially comprises three steps. The first step is the oxidation of kraft pulp either with manganese peroxidase enzyme in the presence of Mn(II) salts, hydrogen peroxide and chelator, or with laccase enzyme preferably in the presence of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), or a combination of both enzymes in a crude mixture as typically produced by certain fungi. The Mn(II) salts and chelator may already be present in sufficient amount in the pulp. This first step is performed at an acidic pH, and moderate temperatures for a period of time between 30 and 240 minutes.
Type:
Grant
Filed:
June 23, 1994
Date of Patent:
November 25, 1997
Assignee:
Pulp and Paper Research Institute of Canada
Inventors:
Michael Geoffrey Paice, Robert Ernest Bourbonnais
Abstract: The invention is concerned with a process for the production of a suspension of cellulose in a liquid, aqueous tertiary amine-oxide, wherein shredded cellulose is mixed with the liquid, aqueous tertiary amine-oxide, said process comprising:(A) contacting the shredded cellulose with the liquid, aqueous tertiary amine-oxide, a first mixture being prepared, and(B) spreading this first mixture mechanically as a layer on a surface and transporting it along this surface while intensively being mixed, until a homogeneous suspension is produced which is removed from the surface, wherein(C) measures (A) and (B) are carried out continuously.
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
Abstract: A plant for the production of cellulose films and fibers includes at least one pulping device for producing a first suspension of pulp in an aqueous amine-oxide solution and a first thin-film treatment apparatus for receiving the first pulp suspension and producing a concentrated pulp suspension. The plant also includes a second thin-film treatment apparatus wherein the concentrated pulp suspension is transformed into a mouldable solution of cellulose and a spinning device connected to the second thin-film treatment apparatus, wherein the mouldable cellulose solution is processed into cellulose films and fibers. A process for the production of cellulose films and fibers according to an amine-oxide process includes the steps of suspending pulp in an aqueous amine-oxide solution to produce a first suspension, concentrating the first suspension, producing a mouldable cellulose solution by heating, and processing the solution to form cellulose films and fibers.
Abstract: A process for the production of a cellulose moulded body, particularly cellulose fibres, characterized by the combination of the measures offeeding a cellulose-containing material into an aqueous solution of a tertiary amine-oxide in order to suspend said cellulose-containing material,removing water from the suspension while intensively mixing it and providing elevated temperature and reduced pressure, until a solution of cellulose is produced andmoulding said solution by means of a moulding device, particularly a spinneret, and introducing it into a precipitation bath in order to precipitate the dissolved cellulose,provided that as said cellulose-containing material, basically shredded waste paper, shredded cellulose-containing fibre assemblies and/or shredded, mechanically and/or chemically broken up annual plants are used.
Type:
Grant
Filed:
June 6, 1995
Date of Patent:
February 11, 1997
Assignee:
Lenzing Aktiengesellschaft
Inventors:
Heinrich Firgo, Dieter Eichinger, Markus Eibl
Abstract: Anti-falsification paper characterized in that thin fragments having brightness, which are obtained by fragmenting nacreous pigment coated paper coated with a nacreous pigment coating solution mainly comprising a nacreous pigment and a binder insoluble in cold water but soluble in hot water, are allowed to exist near the surface of a substrate sheet. Even when falsification is attempted by reproduction using a color copying machine, the colors of the thin fragments having brightness, which are mixed in paper, cannot be reproduced. Therefore, a genuine (original) can be easily distinguished from a forgery (copy). The thin fragments are firmly bonded to paper by the action of the binder, and fall-off of the thin fragments does not occur at the time of printing. Even when anti-falsification paper becomes spoilage or waste paper, thin fragment with brightness does not adversely affect recovery of the pulp.
Abstract: Fungi which grow white/colorless and reduce pitch are used to protect structural wood before or after cutting from logs against color staining by staining fungi.
Type:
Grant
Filed:
May 20, 1994
Date of Patent:
July 2, 1996
Assignee:
Sandoz Ltd.
Inventors:
Robert A. Blanchette, Roberta L. Farrell, Chad J. Behrendt
Abstract: A process and apparatus for the shrinkage of prepared bonded fiber color printed cellulosic type currency where in the process the prepared bonded fiber color printed cellulosic type currency is substantially free (known as oven dry and/or bone dry) before starting the procedure, then is immersed in anhydrous ammonia solution at low temperature, withdrawn and dried by different techniques. The process of immersing and drying is repeated 1 to 8 times. The apparatus to accomplish this provides for a closed loop and/or stainless steel rack and/or stainless steel tong with a thermally controlled vessel. All apparatus to be immersed and all apparatus to be used to contain the anhydrous ammonia solution should be made from a non-corrosive material (i.e. stainless steel and/or glass) to anhydrous ammonia. The color printing to the shrunken prepared bonded fiber color printed cellulosic type currency is not removed.
Abstract: The invention relates to reinforcing and/or process fibers based on plant fibers, obtainable thereby that plant fibers from which the wood components have been removed by ultrasonic treatment are treated with an aqueous solution of at least one metal compound selected among metal oxides, hydroxides, carbonates, sulfates, thiosulfates, sulfites, silicates or phosphates, subsequently washed and treated with an inorganic or organic binding agent or the fibers which have not been washed are neutralized with a mineral acid or that plant fibers from which the wood components have been removed are treated with an oxidation agent or that non-pretreated plant fibers are treated at 250.degree. to 350.degree. C. with the controlled addition of air so that carbonization of the fibers takes place.
Abstract: Polyglycerol esters have been found to be effective antifoam agents in aqueous systems employed in paper processing. Adjunct antifoam agents are not required. Best results are obtained with polyglycerol esters having a degree of glycerine polymerization in the range of 3 to 6 and an esterification range of 15 to 85%.
Type:
Grant
Filed:
November 12, 1993
Date of Patent:
July 4, 1995
Assignee:
Lonza Inc.
Inventors:
Nancy M. Morlino, Philip G. Sweeny, Brian D. Curham
Abstract: A method is disclosed of forming a premix which is suitable for conversion into a cellulosic dope which can be used to produce cellulosic products. The method involves introducing into a mixing chamber predetermined quantities of shredded cellulosic material and a solution of amine oxide at an elevated temperature and stirring the mixture for a period of time by rotating mixer blades within the mixing chamber at a speed of between 40 and 80 r.p.m..