Abstract: Process for dissolving used paper including adjusting a content of solid particles of used paper to a range between about 15 and 35%, kneading the used paper with a specific work of at least about 10 kWh/t, diluting the kneaded used paper to a content of solid particles below about 6%, separating non-fibrous contaminants with wet screening, adjusting a solid material content to less than about 3%, and separating heavy particles with at least one hydrocyclone.

Abstract: A process and apparatus for the preparation of improved cellulose pulps is provided, in which defibered pulp is screened for removal of shives, and fibers with low bonding ability are removed in hydrocyclones, and rejects from the hydrocyclones are treated in refiner. In the process a specific combination of characteristics for the hydrocyclones and the volumetric flow is used in order to prepare pulps which give products of improved qualities, such as higher tensile strength, tear strength, light-scattering, surface smoothness, and especially low shive content.

Abstract: The disclosure relates to a process for the treatment of old paper without the use of biocides and chlorine compounds as well as with the virtual avoidance of hydrogen peroxide and/or peracetic acid with a total germ count of less than 1000 CFU/g and/or a surface germ count of less than 20 CFU/dm2, comprising the following process steps: a treatment of the pre-sorted, optionally pre-shredded, old-paper starting material in an environment containing water in order to activate the microorganism spores, a germination of the spores, a further processing of the old-paper starting material containing germinated spores, preferably in at least one separation stage in a generally known manner at temperatures above room temperature (20° C. to 70° C. [68° F. to 158° F.

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.

Abstract: A method of making sanitary paper products from coarse fibers. The method includes the steps of: (a) pulping coarse fibers in water with agitation to produce a pulp slurry, the pulp from the coarse fibers having an average fines content of greater than about 40%; (b) using an effective amount of pulp washing to reduce the fines content and increase the Canadian Standard Freeness; (c) introducing the pulp at a papermaking consistency into the headbox of a paper making machine; and (d) utilizing the pulp in a paper making process to produce sanitary paper products.

Abstract: A process for controlling/reducing the deposition of stickies from paper stock suspensions in papermaking involving the steps of: (a) providing a paper stock suspension containing stickies; and (b) contacting the stickies in the paper stock suspension with a copolymer of about 75-95 wt % acrylamide and about 5-25 wt % vinyl acetate.

Abstract: The invention relates to a process for obtaining fibers integral with calcium carbonate particles, in which the fibers to be treated are contacted with carbon dioxide generator means and at least one composition comprising Ca++ ions capable of reacting with the carbon dioxide so as to give “in fine” a precipitation of calcium carbonate “in situ” on the fibers. Preferably, the carbon dioxide generator used is calcium bicarbonate.

Abstract: The release of malodorous TRS-containing gases from a comminuted cellulosic fibrous material feed system for a digester is minimized utilizing a particular arrangement associated with a pressure isolation device. Material is fed through the pressure isolation device and the pressure of the material increases from the inlet to the outlet, and the material is discharged from the pressure isolation device into a treatment vessel, such as a horizontal steaming vessel. Malodorous gases from the pressure isolation device are discharged substantially independently of the material discharged from the isolation device, and at least some of the malodorous gases discharged from the pressure isolation device are pressurized (e.g. in an eductor or thermocompressor) and reintroduced into the flow of cellulosic material downstream of the pressure isolation device (for example into the horizontal steaming vessel or a vessel downstream of it).

Abstract: A process of recovering a useful population of fibers and fines from the waste stream of fiber processing facility is disclosed. Steam explosion of the fiber-containing waste stream is used to increase the separation efficiency of the fibers from the ash. The steam explosion also enhances the quality of the recovered fibers and fines, providing a population of recovered fibers which can be incorporated into the fiber component of a tissue or absorbent paper product.

Abstract: Processes are disclosed for extracting sugar rich liquor from sugar cane. The sugar cane is first treated by pulping it in two tub type pulpers having a rotating impeller. The contents of the first pulper are extracted through the bedplate of the extractor and are forwarded onto the second pulper. The contents of the second pulper are extracted through the bedplate of the extractor and are forwarded to form a mat on a moving belt countercurrent extractor of the type having a foraminous belt. Negative pressure is applied below the belt to assist the extraction of a sugar rich liquid component through the belt. The material passes through several separation zones as it travels on the belt with liquid applied to the mat from a region above the belt. The extracted liquid component is collected for further processing.

Abstract: This invention pertains to security paper and methods of making such security paper. The invention comprises a light-colored base paper having a non-protection area of a first thickness, and a protection area of a second thickness on at least one major surface of the base paper wherein the first thickness is greater than the second thickness. The base paper comprises colorant whereby the protection area exhibits a translucence when viewed using transmitted light, and exhibits the colorant as a darker color indication, relative to the non-protection area, when viewed using reflected light. Transmission of light through a combination of paper fibers and the colorant of the invention, both being disposed at the protection area, is discernibly different from transmission of light through the non-protection areas of the base paper, when viewed with a human eye.

Abstract: In the feeding of a slurry of comminuted cellulosic fibrous material to a digester (continuous or batch) in the production of chemical pulp, one of the tanks used in the feed system (which preferably includes a high pressure feeder) may be eliminated without consequent loss of its function by providing a single tank with the combined functions of controlling the level of liquid in a slurrying conduit which supplies slurry to a slurry pump, and storing and substantially continuously supplying liquid to a make-up liquid pump connected to the digester. The single tank preferably surrounds the slurrying conduit and is substantially concentric, and in liquid communication, with it. A gap of 3-48 inches may be provided between the bottom of the conduit and a connection to the slurry pump. A screen or strainer may be provided in the gap, which is substantially surrounded by the tank.

Abstract: An arrangement for adjusting the width of a fibre web in an apparatus comprising two filter wires permeable to water, the filter wires having the same direction of travel, and a conduit for placing pulp suspension between the wires. The arrangement comprises channel for feeding water between the wires and to the edges thereof.

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: Processes are disclosed for processing low consistency newsprint pulp including refining the pulp in a first refiner to a consistency of greater than 2%, screening the processed pulp with a slotted screen basket with a slot width of from 0.05 to 0.15 mm, with the withdrawal of the primary reject portion being greater than 50%, withdrawing the accept portion for further processing, dewatering the reject portion to provide a high consistency pulp, refining the high consistency pulp in a second refiner, screening the processed high width consistency pulp with a slotted screen basket having a slot of less than 0.15 mm, and combining the two accept portions for the further processing steps.

Abstract: A paper composition comprising: at least one cationic thermosetting resin comprising the reaction product of (i) at least one polyamide having secondary amine groups made from reactants comprising at least one polyalkylene polyamine, an acid component comprising succinic acid and optionally at least one dicarboxylic acid (other than succinic acid), and (ii) epihalohydrin. The paper is capable of being repulped substantially faster than paper that is substantially the same except that it contains conventional wet strngth resin.

Abstract: Provided by the present invention is a wet-layed, nonwoven sheet which is comprised of metal fiber and metal powder. Generally, the amount of metal fiber comprises from 20 to 95% by weight and the amount of metal comprises from 5 to 80% by weight of the sheet. Such a wet-layed nonwoven sheet is economically preferable to a sheet comprised totally of metal fiber, since the metal powder is much less expensive. Among other factors, the present invention is based upon the recognition that by using various process techniques, the combination of metal fiber and metal powder can be wet-layed to obtain a structure of sufficient strength for subsequent handling and sintering.

Abstract: By the utilization of a jet ejector (such as a thermocompresser) in a cellulose chemical pulp mill, it is possible to effectively increase the utilization of steam. The volume of steam from a flash tank which flashes black liquor from a pulp digester may be increased (e.g. at least about 10%), while the volume and temperature of the liquor discharged from the flash tank are decreased and its concentration increased, by operatively connecting the jet ejector to the steam discharge from a flash tank. The jet ejector is supplied with higher pressure steam from another source which can result in a low pressure or partial vacuum condition in the flash tank. The flash tank may be a single flash tank or one of a series of flash tanks, and an ejector can be associated with at least another flash tank in the series.

Abstract: Kraft pulp of increased strength and bleachability may be produced with decreased consumption of effective alkali, and at a lower H factor, by keeping the dissolved organic material (DOM) concentration low substantially through the entire kraft cook, including by extracting high DOM liquid from at least one part of a continuous digester and replacing it with much lower level DOM liquid. Existing pulp mills having two-vessel hydraulic, one-vessel hydraulic, or other systems may be retrofit to provide for extractions and additions of low DOM dilution liquor (including substantially DOM-free white liquor). Also, commercial size batch digesters (8 tons per day of pulp or more) can be operated with low DOM liquor to produce increased strength pulp. Using dilution with low DOM liquor also results in reduced H factor and effective alkali consumption, and increased bleachability.

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.