Abstract: A method and a means for manufacturing cellulose pulp from ligno-cellulose fiber material wherein the fiber material is treated under steam pressure. The treatment is carried out in a mill (18, 32) or similar means under such conditions that substantially all the liquid present in the material and/or added thereto during the treatment is converted into gaseous form or steam. The gas or steam thus generated, plus any added gas, is used to convey the cellulose material at high velocity to at least one subsequent separating vessel (22, 36, 38, 40) wherein the fibers entrained with the gas or steam are given a trajectory of motion in the course of which the fiber material is sorted with respect to weight, surface area, or other distinguishing features.

Abstract: The invention relates to a method and apparatus for sorting out recycled paper pulp obtained from scrap material containing contaminants in the form of large pieces of foreign material such as plastics, adhesives, pieces of rope and the like.The invention avoids the need to disintegrate such large pieces of foreign material prior to their removal.The device of the invention comprises a drum (1) with an horizontal axis (2), an end wall (3) of the drum being fitted with a perforated plate (4) and an helical stirrer (5) having profiled blades rotating in a plane parallel to this plate at a short distance thereof, these blades having a transverse cross-section with a hydrodynamic profile adapted for generating a depression in front of the perforated plate, and a leading edge (6) forming a Bernouilli spiral with a constant angle of approximately 30.degree.

Abstract: The latency of mechanical pulp is removed in a quick and simple manner. After refining of comminuted cellulosic material to produce mechanical pulp, the pulp is diluted (if necessary) to a consistency of between about 8-25%, and the pulp is then merely pumped to a further treatment stage. Pumping is effected utilizing a centrifugal pump which fluidizes the pulp, the fluidization imparting sufficient energy to the pulp to remove the latent properties. The pulp may be pumped to a storage stage prior to passage to a screening stage, and can be pumped in a direct (non-return) path from the pump to the screening stage. If desired or necessary, a portion of the pumped pulp can be recirculated and pumped again to ensure that sufficient energy is imparted thereto to effect latency removal.

Abstract: An apparatus for treating a fibre suspension in a liquid to remove therefrom solid foreign particles. The apparatus has an inlet for receiving inflowing fibre suspension mixed with solid foreign particles; a first outlet for discharging part of the suspension liquid and said solid foreign particles; a screen positioned to define a filtering enclosure extending between said inlet and first outlet; a rotor disposed within said filtering enclosure for rotation therein to apply to the suspension fluidizing forces breaking up interlocked fibre flocs present therein and thereby fluidizing a part of said suspension to exit therefrom through said screen; and a second outlet communicating with the exterior of said screen to allow exit of fluidized suspension.

Abstract: A process for the deinking of xerographically printed wastepaper to produce reclaimed stock having high brightness and low dirt count. The process centers upon contact between a wastepaper pulp and an aqueous medium of alkaline pH containing a deinking agent consisting of a mixture of one or more C.sub.5 to C.sub.20 alkanols with nonionic surfactant to form a suspension of the ink in the aqueous medium. The deinking agent suitable for practice of the invention necessarily contains for every 10 parts by weight between 3 and 5 parts of alkanol and between 5 and 7 parts of nonionic surfactant, and is present in the aqueous medium in an amount between about 0.2 and 2.0 percent by weight, calculated on the dry weight of the pulp.

Abstract: A method and apparatus for deinking a fibre stock or slurry. In order to optimize the separation process the invention proposes to independently control the air injection phase, the mixing phase, and the separation phase by splitting them into separate steps.Thus, there is provided a separation cell which is fed with slurry from an inlet. Air is introduced into the slurry before entry into the separation cell and before entering a mixing section which mixes the air and slurry before entering the separation cell. The air is introduced under pressure by way of a porous sintered sleeve, while the mixing is achieved by the provision of three turbulence discs in the preferred embodiment. Alternative turbulent generating means may be employed.The mixing ensures contact of the ink with the air bubbles which separate out in the separation cell and rise to the surface as a foam. The foam is removed by suction, while the deinked fibre slurry is drawn off from the tank by means of a weir or stand pipe.

Abstract: Waste paper is defiberized within a container or receptacle in a thick stock range at a low water level. Thereafter, by further infeeding water, the obtained slurry or the like is diluted to a consistency of less than 7% while continuing the defiberizing operation. Finally, the obtained stock suspension is withdrawn through a sieve or screen located at the floor of a defiberizing container. The defiberizing container or receptacle used for performing the method possesses a lower region having a smaller diameter, above which there is located an upper region having a larger diameter.

Abstract: For the purpose of separating coarse particles from a liquid such as water, e.g. in the cellulose industry, laundries etc., a vertical container is used in which a nozzle receives liquid from a pump and sprays the liquid in the form of a conical liquid jet up against the underside of a screening cloth. Above this cloth there is an outlet for the liquid, coarse particles impinging against the cloth and falling back to the bottom of the container. In accordance with the invention the total flow from the pump and jet is led off via the screening cloth and outlet above said cloth, the liquid level in the container being disposed between the nozzle and the screening cloth so that the liquid jet is sprayed through a layer of the liquid in the container before reaching the screening cloth.

Abstract: An improved inorganic fiber mat containing mineral wool, preferably a composite mat of mineral wool and fiberglass, is prepared by:(a) forming an aqueous slurry of the inorganic fiber raw material containing non-fibrous, particulate contaminants;(b) agitating the slurry to separate heavier contaminant materials;(c) passing the slurry through a unique cleaning apparatus whereby the moving slurry is cascaded and subjected to air induced hydraulic turbulence to separate any remaining contaminant materials; and(d) thereafter transferring the fibrous material, preferably as an admixture of cleaned mineral wool fibers and glass fibers, to a mat forming device.

Abstract: Process and apparatus are provided for cleaning chemical pulp by screening, in which the rejects from a first screening stage are rescreened in a second screening stage; the accepts from the second screening stage are separated in a hydrocyclone, and the clean fraction recycled to the first screening stage; the rejects from the second screening stage are beaten in a refiner and screened before or after the refiner; the suspension from the refiner is taken to the screen before the refiner, and the rejects from the screen after the refiner are recycled to the refiner.

Abstract: A two-stage chemical treatment process is disclosed for increasing the density, strength and brightness properties of mechanical wood pulp. The method comprises the steps of: applying an aqueous solution of sodium sulfite in the range of about 1%-10% sodium sulfite based on bone dry weight of wood to wood particles, the solution having a pH in the range of about 4.5-11; heating the sodium sulfite treated wood particles to a temperature in the range of about 100.degree.-160.degree. C.

Abstract: A wire machine, especially for washing stock suspensions, contains one or a number of dewatering cylinders about which there is trained an endless wire or filter band. There is provided at least one stock infeed device which infeeds a substantially flat jet of the suspension which is to be dewatered into a substantially wedge-shaped space or throat located between the wire band and the dewatering cylinder. The dewatering cylinder has a longitudinal axis which is essentially vertically arranged. There are possible different arrangements of the dewatering cylinder or cylinders, the stock infeed devices and material removal devices for removing from the rotatable dewatering cylinder solid constituents or the like contained in the stock suspension. Also there are possible different arrangements and uses of guide rolls for guiding the wire or wire band.

Abstract: Apparatus and method for use in making non-woven fabrics by wet-laying an aqueous dispersion. The apparatus and method screens, separates and remover fiber defects and foreign matter above a prescribed size from other dispersion fibers. The apparatus includes a housing having an inlet and several outlets, an accelerator within the housing for creating relative movement between the dispersion fluid and fibers to axially align at least some of the fibers in the direction of dispersion flow to disperse those fibers in the dispersion and a separator within the housing for separating bundles and lumps above a prescribed size from other dispersion fibers. The housing discharges the bundles and lumps above the prescribed size from the process at one outlet, and passes the other dispersion fibers through to another outlet for use in the wet-laying process.

Abstract: A process is provided for the removal from paper pulp of impurities, the pulp being contained in a pulping machine. Some of the pulp is periodically transferred into an enclosed chamber annexed to the pulping machine, the chamber having a volume which is small compared to the volume of the pulping machine. The pulp in the chamber is stirred and separated by a rotor, and fibre suspension is returned to the pulping machine, dilution water being introduced into this chamber. The chamber is emptied and impurities thereafter discharged.

Abstract: Rejects such as knots, shives, slivers, chops, and uncooked and partially cooked wood chips are separated from a pulp slurry and treated to produce a bleachable grade pulp. The rejects are dewatered to a 10-15% consistency, mechanically fiberized, and then delignified at the same 10-15% consistency in the presence of oxygen and alkaline pulping chemicals. The delignification is carried out at 80.degree.-140.degree. C. for 5-120 minutes. The process has low external power requirements, requires no expensive dewatering machinery, and proceeds at a rapid rate to yield a bleachable grade pulp which can be used alone or mixed with other pulp.

Abstract: The operation of a centrifugal pump which pumps a liquid or suspension (e.g. 8-12 percent consistency) containing gas is controlled to minimize pump power consumption, or to vary the pump flow rate. The suspension is rotated within the pump so that a gas bubble is created at a central part of the pump, and gas is discharged from the gas bubble, at a gas discharge pressure. The differential pressure between the suspension inlet and the gas discharge is determined, and the head and/or discharge flow rate of the pump are controlled by controlling the differential pressure so determined. The discharge flow rate may be maintained constant utilizing a control valve and flow meter in the pump discharge line, in which case controlling the discharge of gas from the gas bubble controls the head, and minimizes power consumption for a given flow rate. Alternatively the flow rate is controlled by controlling the gas discharge, with no control valve in the pump discharge line being provided.

Abstract: Gas is removed from a fibre suspension of high consistency by means of an apparatus having a rotor chamber and a rotor disposed for rotation in the rotor chamber. The rotor has blades adapted to fluidize the fibre suspension and to cause a centrally located core of gas surrounded by a cylindrical layer of fibre suspension to form. The rotor has a plate located in the portion of the rotor opposite to the inlet of the rotor chamber which has an opening or openings close to the rotor axis. The gas is removed from the rotor chamber through the openings in the plate to a gas discharge and the fibre suspension essentially free of gas is discharged through an outlet. The operation of the apparatus is controlled by maintaining the pressure difference between the inlet and the gas discharge at a predetermined level.

Abstract: To fractionate fiber stock there is used a sieve device which can be constructed in the manner of a secondary stock pulper or fiberizer, yet contains a sieve having a hole size in a range of about 0.8 to 2.4 millimeters diameter. The fiberizer contains a rotor driven by a drive motor and equipped with arms movable around the sieve. At the side of the sieve confronting the rotor there is located a closed long fiber chamber with which merges the infeed line for a cleaned fiber stock suspension which is obtained from waste paper. At the same time a long fiber line leads out of this long fiber chamber into a long fiber vat or container. Behind the sieve there is located a short fiber chamber from which leads a short fiber line to a short fiber vat or container. In at least one of the lines there is arranged a throttle element which is actuated as a function of a signal received from a power measuring device.

Abstract: In an upward gas stream sifter for separating sheet-like pieces of paper and plastic in a wetted mixture, the gas is heated to at least 60.degree. C. in order to dry surface moisture on the plastic. The temperature of the gas is not so high that the plastic shrivels. This increases the difference in density between the pieces of plastic and wet paper, thus assisting the separation.Optionally some gas may enter the mixture feed duct through a gas permeable part of its wall, to prevent accumulation of mixture on the wall.If the mixture is derived from household rubbish and the plastic is mostly polyethylene the gas may enter the sifter at 120.degree. C. and leave it at about 70.degree. C.

Abstract: A method and apparatus for filtering contaminating particles from a liquid/particle mixture. A hollow tank is provided having a peripheral side wall and top and bottom ends. An inlet opening is in the wall adjacent the top adapted to be connected to a source of the liquid/particle mixture. An outlet opening is in the side wall spaced from the inlet opening and intermediate the top and bottom of the tank. A sealable drainage opening is at the lower end of the tank. A filter is mounted in the tank essentially perpendicular to the inlet opening and around a substantial portion of the periphery of the tank. The mounted filter is open at both ends and has filtering apertures in its side. The inlet opening is positioned so that the mixture is introduced in one open end of the filter. Filtered liquid from the mixture passes through the apertures in the side and through the outlet opening and collected portions can be dumped from the outer end through the drainage opening when it is unsealed.

Abstract: Unbleached sulphae fibres are chemically separated from other fibres by the use of high molecular polyalkylene oxides, preferably polyethylene oxide. The polyalkylene oxides are added to aqueous suspensions of fibre mixtures and hereby flocculates unbleached sulphate fibres in a selective manner and the flocks can be separated by known methods such as sedimentation, flotation, filtration etc. Use of polyalkylene oxides for selective flocculation of unbleached sulphate fibres gives the possibility of upgrading for example recovered fibres, broke and secondary fibre raw materials.

Abstract: A method for re-claiming fibers from peanut shells is disclosed wherein the shells are first flattened, the flattened shells are milled to produce a fraction containing fibers and a residue fraction and then the fiber fraction is separated from the residue. The fibers obtained are relatively long staple length fibers and can be used as an absorptive medium, in the form of continuous webs and the like.

Abstract: A seperator, for example, for use in paper production, of the kind having a rotationally symmetrical strainer through which the suspension flows, enclosed in a housing which has an inlet for the suspension to be cleaned and outlets both for cleaned suspension and for impurities held back by the strainer, and having blades revolving in front of the strainer which are divided into part-blades along the axis of rotation, that is, by planes perpendicular to the axis of rotation, and are offset relative to each other in the circumferential direction is disclosed. Several rows of part-blades are arranged over the strainer basket, these part-blades being of such a length and staggered over the circumference in such a way that substantially at every height level, relative to the height of the strainer basket, part-blades from several rows pass by the strainer basket. A separator free of troublesome pressure pulsations is thereby provided.

Abstract: A method and an apparatus for determining the fibre length distribution by weight of a pulp and a method and apparatus for determining absolute consistency are disclosed.The fibre length distribution is obtained by dividing the flow of a pulp sample into two separate flows, fractionating each of the flows by a screen into a retained and a through fraction, the screens being of different mesh sizes, measuring the amounts of each of a selected one of said retained or through fractions and determining, based on the cumulative normal distribution relationship of cumulative retained fraction in % of feed to fibre length, the fibre length distribution of the pulp sample.

Abstract: Apparatus for processing low-grade collected waste paper. Short, so-called zero fibers, which form up to 30 percent of the whole material, and which substantially reduce the quality of paper manufactured therewith are removed, and the bonding properties of the long fiber fraction are removed. It is possible by use of the apparatus to process to paper of good quality from collected low-grade waste paper without previous manual separation of different kinds of waste paper.

Abstract: The disclosure concerns a process and an apparatus for recovering fiber suspension from a mixture of different types of waste paper. The waste paper is disintegrated in a pulper to form a fiber suspension comprised of individual fibers. After perhaps passing a presorting device, the fiber suspension passes through a sorting device which separates the fibers into a long-fiber fraction and a short-fiber fraction. The two fractions are subsequently treated in different ways, generally for the purpose of cleaning the fiber fractions. Various treatment techniques are disclosed, including separating impurities from the long-fiber fraction by flotation and/or bleaching the long-fiber fraction and washing the short-fiber fraction and/or treating it by flotation for de-inking the short-fiber fraction and perhaps thereafter sorting the short-fiber fraction to remove impurities.

Abstract: The method removes a contaminant, such as adhesive or ink particles, from wastepaper pulp. The method includes the steps of dispersing a monomer in the pulp so as to form droplets or beads which take up the particles e.g. by a process in which the particles are coated, absorbed or dissolved by, or adhere to the droplets or beads of monomer. The monomer is then polymerized to increase the rigidity of the droplets or beads, and the droplets or beads are separated from the pulp, e.g. by screening. The monomer or a mixtures of monomers are dispersed in the pulp by strong mechanical agitation and the agitation can be controlled to provide droplets or beads of monomer within a certain size range. Suitable monomers includes styrene, vinyl acetate, methyl methacrylate or mixtures of the same. The viscosity of the monomer phase may be increased by dissolving a homopolymer in the monomer to reduce the effect of shear forces caused by agitation. Benzoyl peroxide may be added to initiate polymerization.

Abstract: Defectively made absorbent articles (e.g., disposable diapers) are shredded for reclamation, and their fluff fillers, mixed with undesired scraps, are fed downwardly towards a forwardly moving horizontal stretch of a conveyor screen. Fluff fibres are forced into a collecting chamber under said screen stretch by maintaining a subatmospheric pressure therein to generate a downward air flow through the screen. Above the stretch are a succession of separating chambers. Under the screen stretch, near the front of each such chamber, is an air outlet from which air is blown upward to lift material off of the screen. Near the front of each chamber, above the screen, is a paddle wheel rotor that propels lifted material rearwardly in the chamber, thus maintaining agitated circulation of material in each separating chamber. When one separating chamber is overloaded, excess material is carried on the screen into the next forward one.

Abstract: Process for producing a mechanical pulp of improved linting properties by screening the pulp to provide a through and a retained fraction, fractionating the through fraction by means of a hydrocyclone into at least two fractions one fraction having an average specific surface less than a predetermined value between 1.2 and 4 m.sup.2 /g and the second fraction having an average specific surface greater than the first fraction and subjecting the first fraction to mechanical processing thereby to form a processed fraction having an average specific surface of 4 to 10 m.sup.2 /g and recombining said process fraction and said second fraction into a combined pulp.

Abstract: An installation for processing waste paper containing a stock pulper or slusher equipped with a rotor and two sieves or screens having different size holes or openings. By means of the sieve having the larger size openings there is conducted the obtained stock suspension through a primary line system which, for instance, leads to a papermaking machine. Cooperating with the sieve having the larger size openings or holes is an auxiliary circulation circuit containing a device for the removal of contaminants or rejects. There is preferably arranged at the auxiliary circulation circuit or system a separator for heavy contaminants or rejects, a pump, a secondary stock pulper or fiberizer and a sieve or filtering device.

Abstract: The toners used for printing in the electrophotography processes such as xerography or laser printing are removed from copy paper. In the process, the paper is pulped to form an aqueous slurry. The toner is removed from the paper with a dual system of a collector and a collecting chemical.The best collectors have solubility parameters similar to the toners so that the softened toner is slightly soluble in the collector. These include polystyrene, polyvinyl chloride and polyacrylates, e.g., polymethyl methacrylates. Other collectors which are operable but less satisfactory are polyurethane and polypropylene. The collector is in the form of prills, beads or sheets. The specific collector will depend upon the specific chemicals in the toner.There are a number of requirements for the collecting chemical. It should be substantially insoluble in water. It should have a melting point that is at or below the approximate softening point of the toner or collector.

Abstract: The specific surface distribution of a pulp may be obtained by fractionating the pulp in a hydrocyclone means into an overflow and an underflow fraction and measuring the specific surface of each of the fractions and the amount of each of the fractions and based on a cumulative normal distribution relationship of cumulative weight fraction as a percent of feed to specific surface, determining the specific surface distribution for said pulp.Also disclosed is a method and apparatus for determining the specific surface of a pulp sample by measuring the light scattering characteristics to obtain a turbidity measurement of the pulp sample, measuring the consistency of the sample and determining the specific surface of said pulp based on the relationship of specific surface to the turbidity measurement for the measured consistency of the pulp.

Abstract: A method and apparatus for providing a cleaned stock issuing directly from a hydrocyclone cleaning system at a consistency of at least 1%, comprising injecting pulp to said hydrocyclone means at a consistency of at least 1%, said hydrocyclone having a tangential inlet for stock, a base outlet for an accepted fraction an apex outlet for a rejected fraction, and at least one dilution water tangential inlet adjacent to said apex outlet for dilution water, adding dilution water to said cyclone means through said dilution water inlet adjacent the apex outlet, rejecting a reject fraction through said apex oulet, and ejecting an accept fraction through said base outlet at a consistency substantially equal to said feed consistency.

Abstract: The disclosure relates to the production of a mineral fiber product for example to replace asbestos fibers in different products. In the method of production, at most 7% by weight of mineral fibers is dispersed in water which contains a wetting agent, undispersible material being then separated and the dispersion being then mechanically dewatered to a dry content of from 30 to 70% by weight and a fiber density of from 200 to 400 kg/m.sup.3. In a subsequent, separate stage, the fibers are redispersed in water substantially without the addition of wetting agent, are provided with possible additives such as cellulose fibers, are shaped, dewatered and dried.

Abstract: A process and plant for treating waste paper in which a beater is employed for rough-pulping the waste paper followed by a first sorting stage from which the separated-out foreign matter is processed further in a subsidiary circuit which includes a vibratory sorter for lightweight foreign matter and a hydrocyclone for heavy foreign matter, the fibers separated out during this further processing being returned again to the treatment process. In the first sorting stage, a sufficiently rigorous separation process is carried out to remove the greater part of the foreign matter, together with unpulped lumps of fibers, which is then passed to the subsidiary circuit in which it and half-stuffs still containing foreign matter, which have been sorted in the hydro-cyclone and in the vibratory sorter, are subjected together to a multi-stage further sorting and speck-removing process.

Abstract: Knots separated from sulphite cellulose produced by a sulphite cellulose cooking process are converted to unbleached sulphite cellulose by first separating and defibrating the sulphite knots and then treating the defibrated sulphite knots with oxygen under pressure in an alkaline milieu at an elevated temperature. The resultant cellulose may be bleached by itself, or mixed with sulphite cellulose produced from knot-free cellulose pulp for bleaching therewith.

Abstract: A sorting apparatus for a stock suspension obtained from waste paper, comprising a separation container having a free liquid surface for the separation of heavy weight particles and floating particles. Arranged after the separation container is a segregating or separator container for the separation of large surface particles floating in the stock suspension. The removal of the particles can be accomplished by rake devices provided with tines or prongs or the like. There also can be subsequently arranged removal devices containing coarse-mesh and fine-mesh sieves.

Abstract: Method and apparatus for pulping and grading waste paper in which stock is introduced through a central inlet in one end wall of a cylindrical chamber and accepts are discharged through a perforate screen in the opposite end wall. An impeller in the chamber adjacent the perforate screen provides for pulping and pumping of the stock as well as provides rotational movement of the stock within the chamber. Light rejects are continuously removed through an outlet adjacent the wall containing the perforate screen while heavy rejects are removed through an outlet adjacent the inlet wall.

Abstract: A method and apparatus for the delignification of cellulosic fiber material to minimize the amount of reject material in the final pulp produced. The fiber material is digested, washed, oxygen delignified, and passed through a screening stage to provide a main pulp stream, and a reject stream from the separation stage. The flow and consistency of the separated reject material is determined, the reject material is refined, and sufficient chemical is added to the separated reject material, based upon the flow and consistency thereof, so that subsequent delignification of the reject material may be effected. This may be accomplished either by passing the reject material through a separate oxygen delignification stage and then returning it to the main pulp stream, or adding caustic to it and soaking it in a soak tank for predetermined period of time, and then returning it to the main pulp stream before the oxygen delignification stage therein.

Abstract: A method and apparatus for treating waste paper by pulping or defibering the paper in a stock pulper or slusher while infeeding water, wherein there are removed in succession, externally of the stock pulper, heavy weight particles, floatable substances and plastic foils. Thereafter, paper constituents which have incompletely defiberized are removed and further defibered in a special apparatus. The already defibered fibers are directly infed for further processing. The removal of the contaminants can be accomplished at a suspension density in the order of 1%, whereas the defibering or pulping of the waste paper in the stock pulper occurs at about 4%. The employed sorting apparatus is connected with the stock pulper, while dispensing with the use of a sieve or screen.

Abstract: A process is provided for preparing groundwood pulp from debarked pulpwood logs which comprises grinding the logs under a superatmospheric pressure of a gas selected from the group consisting of steam, air and steam and air, while continuously supplying thereto process white water and water separated in thickening groundwood pulp suspension at a temperature within the range from about 75.degree. to about 100.degree. C.

Abstract: A process is provided for preparing groundwood pulp from debarked pulpwood logs, which comprises grinding the logs under a superatmospheric pressure of a gas selected from the group consisting of steam, air, and steam and air, while continuously supplying thereto water comprising spent bleaching liquor at a temperature of at least 70.degree. C. and forming a pulp suspension in the resulting aqueous liquor; centrifugally separating steam from the pulp suspension and using the separated hot steam to heat spent bleaching liquor supplied for the grinding; thickening the pulp suspension to a concentration within the range from about 5 to about 40% and supplying water separated therefrom to the grinding; diluting the pulp suspension to a concentration within the range from about 0.5 to about 4.

Abstract: Waste paper is fed into a horizontal drum and therein treated with suitable liquids to form pulp. A magnetic device is disposed adjacent one side of the drum to produce a magnetic field along one arcuate section and extending from the upper portion toward the bottom thereof. Magnetic particles mixed with the paper are carried by said arcuate section of the drum by virtue of the influence of the magnetic field until they reach the top where they leave the field and then fall downwardly into an inclined trough from which they gravitate to the exterior of the drum. Pulp is concurrently discharged from the drum.

Abstract: Paperstock pieces coated with a thermoplastic resin are introduced into and agitated together in a pool of hot, saturated vapors of a liquid, halogenated hydrocarbon capable of wetting the resin. The vapors condense on the resin surface and the resin is loosened and removed by the combined actions of the agitation and of the vapors and condensate.

Abstract: A method for recovering cellulosic fibres from thermoplastic-fibreboard laminates such as fruit juice and milk cartons. The method involves heating the laminate in a pulping liquor to a temperature equal to or greater than the softening point of the thermoplastic material. This is followed by cooling to a temperature below the softening point and defibration by mechanical or explosive means. The method results in a mixture of thermoplastic fragments and cellulosic fibres which can be readily separated by conventional means. Pressure may be applied to the laminate/liquor system to accelerate the process.

Abstract: In the recovery of cellulosic fibre of papermaking quality from foil laminated papers and boards, the laminate is heated and pressurized in the presence of an aqueous liquor, subjected to rapid discharge to a lower pressure environment under reduced pressure and optionally subjected to mechanical agitation. This treatment provides a product stream which can be separated into cellulosic fibre suitable for the further manufacture of fibrous cellulosic articles and a metallic foil suitable for subsequent manufacture of metallic articles.

Abstract: A method and a system for cleaning and classifying fibrous suspensions whereby the suspension, by screening, is divided into a first stream of accepted stock and a second stream of rejected stock. The latter is then screened once more and thereby divided into a third stream of accepted stock and a fourth stream of rejected stock. The third stream is added to the first stream, whereas only the fourth stream is subjected to a fibre flake break-up process followed by a further screening process resulting in a stock finally rejected and an accepted stock added to the fibrous suspension upstream of the means for carrying out the first screening.

Abstract: The waste water obtained from a papermaking process is purified to remove the last traces of fibers suspended in the water by mixing the waste water with those contaminating materials that are separated from the paper pulp suspension before it is fed to the papermaking machine. These contaminants act as a filter aid and make it possible to separate the fibers remaining in the water phase after the water from the papermaking machine has been subjected to a flocculating process, filtering and screening.

Abstract: Cellulosic fibers are removed from seed hulls such as cottonseed hulls by a process including (a) in the absence of mechanical action sufficient to cause degradation of fiber properties, contacting the seed hulls which comprise both cellulosic fibers (linters and hull fibers) and non-fibrous hull components with an alkaline solution and an oxygen-containing gas until the cellulosic fibers are substantially free of the non-fibrous hull components, and (b) recovering the cellulosic fibers from the non-fibrous hull components so as to produce readily washable cellulosic fibers having substantially unimpaired mechanical properties. The cellulosic fibers may then be washed and separated according to known fiber fractionation procedures. The cellulosic fibers produced according to this improved process have substantially unimpaired mechanical properties and contain substantially no polyphenolic materials or extraneous color components.

Abstract: Apparatus and method for use in making non-woven fabrics by wet-laying an aqueous dispersion. The apparatus and method screens, separates and remover fiber defects and foreign matter above a prescribed size from other dispersion fibers. The apparatus includes a housing having an inlet and several outlets, an accelerator within the housing for creating relative movement between the dispersion fluid and fibers to axially align at least some of the fibers in the direction of dispersion flow to disperse those fibers in the dispersion and a separator within the housing for separating bundles and lumps above a prescribed size from other dispersion fibers. The housing discharges the bundles and lumps above the prescribed size from the process at one outlet, and passes the other dispersion fibers through to another outlet for use in the wet-laying process.