Abstract: A densifying agent is applied to fibers in order to improve the densification properties of the fibers. The fibers have hydrogen bonding functional groups. The densifying agent are denser than the fibers to which the densifying agent is applied. The densifying agent can be organic or inorganic. The improved densification properties are observed without the presence of particles bound to the fibers or in the presence of particles that are not bound to the fibers. Softening agents can also be applied to the fibers in order to soften the fibers and articles including such fibers. Softening agents may be selected from the group of densifying agents.

Abstract: A pulp bleaching line has an initial stage using gaseous bleaching reagent followed by its subsequent stages without intervening washing or pumping steps. The pulp is transported from the initial stage through a mixer in which the pulp is heated and/or dosed with bleaching chemicals and through the subsequent stage by retained gas pressure developed in the initial stage. A portion of the retained gas may be separated and purged from the mixer through a pressure regulating device to optimize pressure for processes which follow the mixer/heater. This permits elimination of a washer and pump normally provided between the initial reactor and subsequent bleaching stage.

Abstract: A method and an apparatus for wetting fibrous material, such as coarsely shredded waste paper. Fibrous material and wetting fluid is introduced into a wetting enclosure. Pressure is decreased within the wetting enclosure for a short period of time for sucking out air from the fibrous material. Pressure is allowed to increase rapidly, whereby wetting fluid is sucked into cavities within the fibrous material and the material is efficiently wetted.

Abstract: Measurement device for quantitatively detecting constituents of a pulp/fluid mixture for paper and/or cardboard production. The device includes at least one radiation source for irradiating the mixture in a number of definite, different wavelength ranges. The device also includes at least one sensor for measuring the intensity of radiation that has been influenced by the mixture, and at least one set of measurement electronics. Each sensor detects only one of the definite, different wavelength ranges of the radiation at a particular time.

Abstract: A method in connection with the pretreatment of comminuted fibrous material intended for chemical cellulose pulp production. The fibrous material is fed through a low pressure system that has a gas phase part followed by a liquid phase part. The liquid phase part includes a low pressure circulation where a circulating liquid is withdrawn from the fibrous material and recirculated back to the fibrous material in an upstream position. The fibrous material is sluiced into a high pressure system that has a liquid phase transfer part operatively connected to a digester. A hot process liquid and/or the circulating liquid are evaporatively cooled by being allowed to flash within the low pressure system.

Abstract: A method in connection with continuous cooking of chips, comprising impregnation of the chips with impregnation liquid in an impregnation vessel (3) and cooking of the impregnated chips in a digester (4), the impregnation vessel and the digester being connected to each other by means of a transfer circulation, which partly, via a feed line (25), feeds the chips from an outlet end (27) of the impregnation vessel to the top of the digester for separation of free liquid in a separator (28), and partly, via a return line (26), feeds separated liquid from the top of the digester to the outlet end of the impregnation vessel for use as transfer liquid for the impregnated chips, besides which cooking liquid is added to the chips in the top of the digester. According to the invention, as a first part, less than 100%, preferably less than 95% and more preferred less than 90% of the liquid which is separated from the chips in the transfer circulation, is recirculated to be used as transfer liquid.

Abstract: A new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy and at the same time achieve very good pulp properties. The digesting process includes a top separator that separates the transport liquid from the fiber material and permits the fiber material to be exposed to the cooking liquid.

Abstract: A method of processing recycled waste paper includes pulping waste paper in a first drum pulper. White fibers are separated from the waste paper in a first screen drum. The white fibers are then processed by screening, cleaning, deinking and bleaching. The remaining waste paper is pulped within a second drum pulper. The brown fibers are separated from the waste paper in a second screen drum. The brown fibers are processed by screening, cleaning and bleaching.

Abstract: An electrochemical process is provided for treatment of molten kraft smelt produced from black liquor in a kraft recovery boiler. Treated smelt can be contacted with water to produce white liquor which can be re-used or recycled in the kraft process.

Abstract: Process and measurement device for quantitatively detecting constituents of a pulp/fluid mixture for paper and/or cardboard production. The device includes at least one radiation source for irradiating the mixture in a number of definite, different wavelength ranges. The device also includes at least one sensor for measuring the intensity of radiation that has been influenced by the mixture, and at least one set of measurement electronics. Each sensor detects only one of the definite, different wavelength ranges of the radiation at a particular time. The process includes irradiating the mixture with at least one radiation source, the irradiation occurring in a number of definite, different wavelength ranges; and measuring the intensity of radiation that has been influenced by the mixture by at least one sensor. Each sensor detects only one of the definite, different wavelength ranges of the radiation at a particular time.

Abstract: A process for dewatering lime mud in a kraft pulping process is described. The process includes an improvement which comprises adding an effective amount of an alkyleneamine to the lime mud prior to filtration. The preferred alkyleneamine is ethyleneamine, that is, an amine having at least one —(CR2—CR2—NH—)— unit wherein each R independently is H or an alkyl (straight, branched or cyclic) group of from about 1 to about 10 carbon atoms. Ethyleneamines include ethylenediamine, diethylenetriamine, triethylenediamine, triethylenetetramine, tetraethylenepentamine, piperazine, aminoethylpiperazine, and ethyleneamine mixtures such as mixtures of ethyleneamine oligomers having an average molecular weight of about 200-500.

Abstract: There is provided a deinking process carried out using white water according to which an excellent whiteness and an excellent areal ratio of residual ink fines can be secured while maintaining a proper pulp yield. In the deinking process comprising a flotation step wherein use is made of treatment water containing white water, at least part of the flotation step is effected in the presence of at least one compound selected from the group consisting of cationic compounds, amine compounds, acid salts of amine compounds, and ampholytic compounds.

Abstract: Provided by the present invention is a process for making wet-layed metal fiber nonwoven sheet. The process comprises dispersing a mixture of metal fibers, wood pulp and a fibrillated material into an aqueous dispensing fluid. The amount of metal fibers dispersed generally ranges from 60 to 80 weight percent, based on the weight of solids, with the amount of wood pulp ranging from 15 to 30 weight percent and the amount of fibrillated material ranging from about 5 to 10 weight percent. The dispersed mixture in the aqueous dispensing fluid is then applied to a screen, with the aqueous dispensing fluid being removed to thereby form a metal fiber sheet.

Abstract: A nonionic surfactant having cyclic 1,3-dioxane and/or 1,3-dioxolane functionality which is irreversibly splittable by lowering the pH of its aqueous solution is useful in various processes requiring the removal of emulsified hydrophobic contaminants or other hydrophobic materials from an aqueous stream. After splitting of the surfactant into its component aldehyde and polyol, the hydrophobic components phase-separate and can be removed from the aqueous stream by routine means.

Abstract: Steam (preferably clean steam) having less noncondensible gases than steam produced by conventional black liquor flashing is produced from hot black liquor from a digester of a pulp mill. A heat exchanger is utilized and the hot black liquor is passed through the heat exchanger in heat exchange contact with an evaporable liquid, preferably clean water. After the water is heated in the heat exchanger it is flashed in at least one flash tank where the heat exchanger is a liquid-to-liquid heat exchanger. The heat exchanger may alternatively include an evaporator (such as a falling film evaporator) in which case the black liquor is passed through an inductor before it enters the evaporator. Alternatively, the heat exchanger may be one or more boilers, such as kettle boilers, in which case the black liquor preferably passes through a cooler after the boilers. Heat energy and turpentine recovery are also maximized.

Abstract: A process for removing capsule oils from carbonless copy paper involving: (a) providing carbonless copy paper containing capsule oils; and (b) disintegrating the carbonless copy paper in the presence of an alkoxylated C12-14 alcohol to form a stock suspension.

Abstract: A process for producing a pulp suitable for papermaking from a nonwood fiber source material. Representative nonwood fiber source materials include corn stover and wheat straw. The process includes the steps of providing a nonwood fiber source material; digesting the nonwood fiber source material with an alkaline pulping solution at at least about atmospheric pressure; reducing the pH of the nonwood fiber source material to an acidic pH with an acid solution; treating the nonwood fiber source material having an acidic pH with ozone; and treating the nonwood fiber source material with a bleaching solution to form a papermaking pulp.

Abstract: There is provided a stock of paper nuggets for manufacturing composite building materials, wherein the stock of paper nuggets comprises a large portion of paper nuggets each having a thick mass, a twisted core and a tailed configuration. This stock of paper nuggets is advantageous for being composed of cohesive entities which can be manipulated on a construction site or sold to the public in bags, for use in backyard projects. The paper nuggets have good mold-filling and interlacing properties for manufacturing paper-based products having an homogenous structure and good mechanical properties. There are also provided a method and apparatus using one or more spherical rotors for penetrating a wet paper mulch, for pulling paper nuggets out of this wet paper mulch and for imparting in these paper nuggets their interlacing properties.

Abstract: A paper-making machine includes at least one roll for carrying a fiber web or a belt. At least one of the rolls includes a shell formed from a composite material; a journal comprised of metal; and a head interposed between and interconnecting the shell and the journal. The head is also formed from a composite material.

Abstract: The present invention provides methods for reducing fluorescence in a paper-containing sample. Methods for destroying fluorescent whitening agents in a paper-containing sample are also provided.