Abstract: In a single-vessel system for continuous cooking of kraft pulp, chips and liquor are conveyed from a high pressure feeder in a transfer line to a first end of a digester. A part of the liquor is separated from the chips that are withdrawn from an outlet defined in an upper part of the digester and conveyed in a return line to the high pressure feeder. A constituent flow of liquor is led from the return line and heated and fed via one or more inlets into the digester at a location that is downstream of the outlet for the return line.

Abstract: Apparatus and process in a machine for at least one of producing and processing the fibrous web. The apparatus includes an essentially water-free traveling surface adapted to guide the fibrous web, and a measuring device positioned and adapted to detect moisture content of the fibrous web while the fibrous web is supported by the essentially water-free traveling surface. The process includes guiding the fibrous web on the essentially water-free traveling surface, and detecting a moisture content of the fibrous web while the fibrous web is supported by the essentially water-free traveling surface.

Abstract: The method of the invention involves treating cellulosic vegetable matter (the “Feed Stocks”) for the selective recovery of lignin (when present in the feed-stock), cellulose and hemi-celluloses by: (1) reducing the material to be processed to an appropriate size; (2) adjusting the moisture content of the ligno-cellulosic feed stock to 15 percent to 30 percent water; (3) impregnating the ligno-cellulosic feed stock with an extraction liquor containing a glycol and an organic or Lewis acid; (4) rapid heating of said impregnated feed stock to a temperature of about 118° C. to about 145° C.; (5) maintaining the desired temperature for about 1 minute to about 6 minutes to solubilize the lignin therefrom (a period of about 2 minutes to about 5 minutes is preferred); (6) stopping the reaction immediately by lowering the temperature to <100° C.

Abstract: An apparatus for obtaining watermarks or patterns in paper or cardboard while being formed on a formation tape or table in a paper or cardboard manufacturing plant, comprising: a primary fibrous mix source for storing a primary fibrous mix; at least one manifold, which can be arranged proximate to the formation table; at least one jet nozzle which can be fed by the at least one manifold and is arranged above the formation table so that it can be angularly adjusted with respect thereto; a feeding duct for a secondary fibrous mix and a return duct from the at least one manifold; and a secondary fibrous mix source arranged to supply the feeding duct and to receive material discharged from the feeding duct for return from the at least one manifold.

Abstract: A deinking method comprising the steps of liberating ink from waste paper as a raw material and removing the liberated ink from a flotation system, wherein a nonionic surfactant, e.g., a reaction product obtained by adding an alkylene oxide to a mixture of an oil & fat and an alcohol, an alkylene oxide adduct of a fatty acid, or an alkylene oxide adduct of a higher alcohol, is used for the liberation of ink, and the flotation step is effected in the presence of a cationic compound, an amine, an acid salt of an amine or an amphoteric compound at a pH of from 4 to 9, provides a high quality deinked pulp having a high whiteness and a little residual ink spots.

Abstract: Cellulosic fines and cellulosic fibers are separated from a suspension containing the fines, the fibers and hydrophobic materials by screening the suspension to remove the fibers, and then subjecting the resultant filtrate to dispersed air flotation in the presence of calcium and generally a separation aid to form an upper Reject fraction in which the hydrophobic material is concentrated and a lower Accept fraction in which the cellulosic fines are concentrated.

Abstract: Chemical cellulose pulp (e.g. kraft pulp) is produced with enhanced strength and/or yield using a strength or yield enhancing additive such as polysulfide or anthraquinone or its equivalents or derivatives, and in a manner that allows effective recovery/reuse of the additive so as to make the process more economical. In a continuous digester a low temperature and relatively low alkalinity protecting zone is provided at the top of the digester terminating with a first screen, and a second screen is provided below the first screen. Between the first and second screens, prior to bulk delignification, a first counter-current zone is provided, and additive-containing liquid from the first screen is recirculated to the slurry at or near the digester inlet to enhance yield or strength.

Abstract: The present invention relates to methods for deinking and decolorizing a printed paper, comprising: (a) pulping the printed paper to obtain a pulp slurry; (b) dislodging an ink from the pulp slurry with one or more enzymes; (c) decolorizing the dye contained in the pulp slurry with one or more laccases in the presence of oxygen and optionally one or more chemical mediators; (d) separating the released ink from the pulp slurry; and (e) recovering the decolorized pulp. The present invention also relates to decolorized pulps prepared by such methods and to methods for producing recycled paper.

Abstract: A composite is provided for forming a sealing strip for use in a suction roll of a papermaking machine or other device for maintaining a seal when brought into contact with a surface and that has extended usability and wear. The composite is a blend of a nitrile rubber, graphite, carbon black, and at least one of a silicone oil or polytetrafluoroethylene as a lubricating agent, optionally with a phenolic resin. The sealing strip has silicone oil and/or polytetrafluoroethylene evenly distributed over the contact surface, and when installed into a suction roll or other device, provides a reduced frictional surface.

Abstract: A single plant for making corrugated sheets out of recycled paper and a method for making the same. The plant includes a recycling pulper a board machine and a corrugator.

Abstract: A method and apparatus for measuring thickness of a fiber material during manufacture of the fiber material, especially paper in a paper-making machine, comprises a gamma radiation transceiver in communication with a processing/control system. The gamma radiation transceiver is placed at a points along the production path of the web of paper being produced and liberates gamma radiation towards the fiber material. Backscatter of gamma radiation is received by the gamma transceiver also which generates corresponding signals that are received by the processing/control system. The processing/control system processes the signals to determine a thickness profile along a cross-section of the web. The processing/control system may be in communication with or considered a subset of a main processing/control system for the paper-making machine. A gamma radiation shield may be used with the gamma transceiver and is mounted on the side of the paper web opposite the gamma transceiver.

Abstract: A record sheet for use in an electro-coagulation printing method, which comprises a base sheet and a layer provided thereon composed of at least one filler selected from the group consisting of alumina sol, boemite, pseudo boemite, synthetic amorphous silica, silica sol and colloidal silica and a binder, wherein said record sheet satisfies the following properties; (i) a wet time of the record sheet obtained from a liquid absorption curve of pure water measured by a dynamic scanning absorptometer being not more than 15 milliseconds, (ii) an absorption coefficient of the record sheet obtained from a liquid absorption curve of pure water measured by a dynamic scanning absorptometer being at least 10 ml/m2s−½, and (iii) a contact ratio of the record sheet with the coagulated colloids measured by a specular reflection smoothness tester under a pressure of 40 kg/cm2 with a ray having a wavelength of 0.

Abstract: A doctor blade structural support has the form of a hollow structural member of roughly triangular cross-section, one side of the triangular cross-section being substantially tangent to the surface of the dryer roll. A quantity of water is disposed within the hollow structural member and resides on the inside surface of the structural member adjacent to the heated dryer roll surface. The interior of the doctor support structure is sealed from the atmosphere and is evacuated so that the interior of the structure contains only water and water vapor. Heat radiating from the dryer roll surface to the doctor support structure causes water disposed on the inside surface adjacent to the dryer roll to evaporate, thus raising the internal vapor pressure in the sealed interior of the doctor support structure. The water vapor continuously condenses on the inside surfaces of the support structure which are not exposed to radiant heating from the dryer roll.

Abstract: The invention refers to a method for black liquor gasification in recovery boilers, of the type having a lower portion, referred to as a lower furnace and an upper portion, referred to as an upper furnace, black liquor sprayers for introduction of black liquor provided in the boiler above the lower furnace, and a number of combustion air levels, whereby the invention incorporates adding oxygen enriched air to the combustion air or directly into the lower furnace at at least one air level underneath the liquor sprayers for the purpose of creating the best possible reducing conditions in the lower furnace, redistributing from the lower furnace combustion air not needed therein following the addition of oxygen enriched air, thereby significantly reducing upward gas velocity underneath the black liquor sprayers, and introducing the redistributed combustion air in the upper furnace, thereby creating the reducing conditions and a controlled temperature in the lower furnace for emission control.

Abstract: An aqueous slurry containing dissolved solids and a high concentration of suspended solids is positioned as a mat between a pair of porous endless belts to provide a composite structure. The composite structure is moved through a treating zone and subjected to alternate stages of compression and relaxation. In a preferred mode, the compression and relaxation are achieved by passing the composite structure over a series of spaced rolls in a manner such that a first belt of the pair is in direct contact with one of the rolls and a second belt of the pair is in contact with the next adjacent roll. A liquid stream containing a high concentration of dissolved solids is cascaded over the mat in a countercurrent fashion, with the result that dissolved solids of the liquid stream are dissolved in the aqueous phase of the mat when the mat is subject to relaxation. The mat containing the increased concentration of dissolved solids and suspended solids can then be compacted and the solid residue can be landfilled.

Abstract: A method of de-inking cellulosic fibrous materials comprising: a. admixing an alkaline reagent selected from the group consisting of ammonium hydroxide and hydrogen peroxide and mixtures thereof with an aqueous suspension of inked cellulosic fibrous material such that they react at the ink particle/cellulosic fiber interfaces to dislodge ink particles from the cellulosic materials; and b. removing the dislodged ink particles from the aqueous suspension.

Abstract: The present invention relates to a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, and to the use of a thus obtained pigment slurry for the preparation of a coating compound for the paper industry or in the paper stock for papermaking. An essential element of the invention is a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, characterized in that the residual water sludges containing the fillers and coating pigments are subjected to mixing and then milling together with fresh pigments or fresh fillers in the form of powders, fresh-pigment containing slurries and/or fresh-filler containing slurries to yield a pigment slurry.

Abstract: A method in connection with continuous cooking of chips that comprises impregnating the chips with a impregnation liquid in an impregnation vessel and cooking the impregnated chips in a digester. The impregnation vessel and digester are connected to one another by means of a transfer circulation, which partly, via a feed line feeds the chips from an outlet end of the impregnation vessel to the top of the digester for separation of a free liquid in a separator. The separated liquid from the top of the digester is, partly, via a return line fed to the outlet end of the impregnation vessel for use as a transfer liqid for the impregnated chips to which cooking liquid is added to the chips at the top of the digester. Less than 100%, preferably less than 95%, and more preferred less than 90% of the liquid that is separated from the chips in the transfer circulation is recirculated to the used as transfer liquid.

Abstract: The invention relates to a process and apparatus for pretreating pulp raw material, to be subsequently prepared in a chemical pulping process, and for preparing cellulose pulp from a fibrous starting material. According to the process the starting material is delignified to yield a chemical cellulose pulp, and the obtained pulp is bleached when desirable. According to the invention the starting material is crushed in cooking liquor prior to delignification in order to open its fiber structure. The apparatus of the invention comprises a frame (21), to which to adjacent first rolls (12; 22, 23) have been fitted, which form a first pair of rolls with the rolls arranged to distance from each other in such a manner that a gap clearance is formed between their outer mantles. The rolls are caused to rotate by a means of power transmission, which causes the raw material to be crushed inside the gap between the rolls where a liquid pocket is formed, from which liquid is absorbed into the fiber material being treated.

Abstract: The invention relates to a method for inhibiting and eliminating adhesive impurities, so-called stickies, from waste paper preparations or paper pulp containing prepared waste paper in the paper industry by using classic sorting- and dispersion equipment and a flotation unit consisting of one or more flotation stages containing deinking froth. In the course of preparing the waste paper for making a paper pulp which is fed to a paper machine, a hydrophobized synthetic or natural mineral is added to the pulp before or during its introduction into the paper machine, causing the microstickies to be adsorbed by the added hydrophobized mineral and removed by same from the flotation unit via the deinking froth.