Abstract: A liquid deinking composition comprising (a) a fatty acid mixture containing 40 to 90 weight % of saturated fatty acids having 12 to 14 carbon atoms and less than 60 weight % of saturated fatty acids having 16 to 18 carbon atoms, (b) a nonionic surfactant with HLB of 2 to 12 in a proportion of (a)/(b)=5/95 to 40/60 (weight ratio), and (c) 0 to 20 weight % (based on the composition) of water.No crystals of fatty acids are precipitated at ambient temperatures, and the separation, solidification or precipitation of crystals due to a temperature change is not caused. Further, the handling property is improved because of the liquid form.

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 method of bleaching recycled paper containing pulp wherein said pulp is contacted with ozone in an ozone stage (Z) treatment with a brightness stabilizing step during or at the end of said ozone stage (Z), said stabilizing step consisting of contacting a small amount of hydrogen peroxide with said pulp, the amount of hydrogen peroxide contacted with said pulp being small compared to the amount of hydrogen peroxide usually in an hydrogen peroxide stage, no washing step of the pulp being provided between the ozone contacting step with said pulp and the hydrogen peroxide contacting step. The pulp is first submitted to a test procedure to determine whether the pulp is more reactive to ozone in acidic or alkaline conditions, and if necessary the pH is accordingly adjusted.

Abstract: This invention provides an integrated system for recovering fibers from mixed grades of waste paper and simultaneously cleaning (deinking) waste fibers. The system comprises a mild alkaline pulping process with oxygen and hydrogen peroxide followed by rapid decompression of fibers and then by hot washing.

Abstract: The invention relates to a method for decolorizing paper pulp containing colored fibers. The paper is first pulped and subjected to fine screening. The screened pulp is then dispersed at a temperature in excess of 100.degree. C. and a pressure exceeding one atmosphere absolute pressure. Prior to the dispersing step a first agent (a reducing agent or oxidizing agent) is introduced to the pulp. A second agent is introduced to said pulp after introduction of the first agent. The second agent is an oxidizing agent when the first agent is a reducing agent, and a reducing agent when the first agent is an oxidizing agent. Finally, the dispersed pulp is recovered after the colored fibers are decolorized.

Abstract: A composition containing a persulfate and a carbonate, a bicarbonate or sesquicarbonate, which composition is suitable for oxidizing wet strength resin based broke used in wet strength paper. The combination decreases the time required for effectively repulping broke from such paper. Additionally, the combination is a single product capable of beaking down the wet strength resin and adjusting or maintaining pH at a predetermined value without additional chemical treatment.

Abstract: A process for using ejectors to combine high pressure steam and low pressure oxygen to produce a steam and oxygen enriched gas single phase gas mixture for introduction into various pulp treatments using oxygen with the benefit of low cost compression, low capital requirements and superior oxygen mixing.

Abstract: Paper and paperboard can be effectively repulped by a composition of nonchlorinated oxidizing agent (persulfates) and a buffer (carbonates) yielding a pH of 7-12. The repulping composition of the present invention is particularly useful in repulping paper containing wet strength resins.

Abstract: The present invention discloses a process for treating filter rods comprising cellulose acetate tow waste comprising the steps of:a. cutting said filter rods so that fiber of said cellulose acetate have a fiber length of less than about 4 inches; andb. treating said cut filter rods with an aqueous base until at least 5% of acetyl groups on said cellulose acetate has been hydrolyzed.Filter rods treated in this manner are suitable for use in various paper products. The process of the present invention may further include a step for repulping the cut filter rods to repulp any included plugwrap.Modified fiber comprising cellulose acetate wherein at least 5% of acetyl groups on said cellulose acetate have been hydrolyzed, said fiber having a length of less than about 4 inches, are also disclosed.Paper products comprising between about 5 and about 90% of the fiber of claim 21 and paper pulp are also disclosed.

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.

Abstract: Wastepaper containing printing ink is refined in the presence of the reaction products of epoxidized derivatives of C.sub.10 -C.sub.22 carboxylic acids with alkoxylated carbohydrate-derived polyols and the detached printing ink particles are subsequently removed from the paper stock suspensions by flotation or washing.

Abstract: Process for repulping wet strength paper containing at least one wet strength resin in which initial breakdown of the paper is conducted at a first pH and the substantial completion of the conversion to fibers is conducted at a second pH which is higher than the first pH.

Abstract: A method for bleaching pulp containing pulp from color dyed waste paper, wherein the method comprises bleaching the pulp with a bleaching chemical, especially sodium hydrosulfite, in the presence of a selected ethoxylated amine.

Abstract: Provided herewith is a process for reducing the fluorescence of pulp fibers. The process comprises contacting the pulp fibers with ozone in two or more stages, with an intermediate washing stage or bleaching stage preferably being conducted in between the ozone contacting stages. It has been discovered that splitting the total ozone charge into two or more stages provides a much more efficient and effective process for reducing fluorescence.

Abstract: An improved duplex linerboard is formed from old corrugated containers (OCC) by first repulping the OCC and screening it to provide a fine fraction and a coarse fraction. NaHSO.sub.3 or H.sub.2 O.sub.2 is applied to the fine fraction and the fine fraction produce a chemically treated fine fraction which is then refined. Coarse fraction is separately refined and the refined coarse fraction pulp is then used to form the bottom ply of a multi-ply board and the refined fine fraction pulp used to form the top ply of the multiply board.

Abstract: Waste lignocellulosic material, for example brown kraft grocery bag and corrugated paperboard, is treated in a multi-step process to produce a recycle brownstock pulp having a sufficiently low kappa number that it may be bleached according to conventional means such that its final optical and strength properties are comparable to that of virgin pulps bleached according to similar means; biological enzymes are used in conjunction with medium consistency pulping to separate fibers and loosen contaminants, such as wax and adhesives; low temperature soaking of waste lignocellulosic material in an alkaline peroxide liquid using long reaction times is used to minimize energy consumption, degrade contaminants, and to selectively remove lignin; loosened contaminants and poorly bonding lignocellulose debris are removed by screening and cleaning methods; high consistency peroxygen cooking is used to substantially delignify the pulp and to destroy contaminants in an energy efficient manner; liquid streams are treated an

Abstract: Waste cellulosic paper products, for example, old corrugated containers are recycled employing oxygen delingnification in the presence of an alkaline material to produce a recycled pulp of lower kappa number, while maintaining adequate strength in the pulp. The recycling process preferably employs an acid pretreatment in combination with the oxygen delignification, and exposure of the waste product to the alkaline material is preferably controlled so that at any point in the delignification the waste product is exposed to not more than 50%, by dry weight, of the alkaline material based on the weight of residual lignin in the waste paper product.

Abstract: A number of different, efficient treatments of slurries and liquid with gas can be provided. A slurry or liquid is introduced into a first end of a vortex. A gas--such as a chemically reactive gas--is introduced from exteriorly of the vortex into contact with the slurry or liquid in the vortex, so that a desired reaction between the slurry or liquid and the gas takes place. The treated slurry or liquid is removed from the second end of the vortex while any residual or carrier gas is removed from the first end of the vortex. Gas introduction is preferably accomplished through a porous surface of revolution (e.g. cylindrical or conical) wall surrounding the vortex, the gas being in minute bubble form when it enters the slurry or liquid.

Abstract: A process of recycling printed paper that contain a coating of a plastic olefin polymer by either (a) treating the deinked paper material with an oxidizing agent and reforming the deinked paper material into paper or (b) reforming the deinked paper material into paper and then treating the reformed paper with an oxidizing agent is described. The deinked paper material consists of fibers containing both cellulose and a plastic olefin polymer; fibers which are a mixture of cellulose fibers and fibers containing both cellulose and a plastic olefin polymer; fibers which are a mixture of cellulose fibers, fibers of a plastic olefin, and fibers containing both cellulose and a plastic olefin polymer; and fibers which are a mixture of fibers of a plastic olefin polymer and fibers containing both cellulose and a plastic olefin polymer.

Abstract: The invention relates to a method of bleaching waste paper pulp. The pulp is first treated to a reductive chemical followed by acidification and washing or dewatering. The pulp is then subjected to ozone and then to hydrogen peroxide. The reductive chemical used is either formamidine sulphinic acid or sodium hydrosulfite.

Abstract: Deinked paper/wood pulps are improvedly bleached to high levels of whiteness by conjointly treating such pulps with a sulfite bleaching agent, e.g., Na.sub.2 SO.sub.3, NaHSO.sub.3 or mixture thereof, or SO.sub.2 and NaOH, and a reducing agent more electronegative than the sulfite ion, e.g., thiourea dioxide, sodium borohydride or sodium dithionite, in a reaction medium having an initial pH ranging from 6 to 12, advantageously followed by washing sulfite and reducing agent values from the bleached pulp and then treating the washed pulp with hydrogen peroxide in an aqueous alkaline medium.

Abstract: A process for repulping wet-strength paper containing at least one wet-strength resin in which a hydroperoxide alone or in combination with a non-alkali, non-alkaline earth metal salt or chelate is used to separate the resin from the wet-strength paper.

Abstract: A method for deinking of repulped xerographic paper comprising adding an organic polymeric particulate and a substantially water insoluble organic ester to a repulped aqueous slurry containing xerographic toner particles in an amount sufficient to at least partially agglomerate the xerographic toner particles within the slurry to larger particle sizes; and removing the xerographic toner particles from the slurry by one or more liquid/solid separation techniques.

Abstract: A method for deinking of repulped xerographic paper comprising adding an organic polymeric particulate and a substantially water insoluble organic ester to a repulped aqueous slurry containing xerographic toner particles in an amount sufficient to at least partially agglomerate the xerographic toner particles within the slurry to larger particle sizes; and removing the xerographic toner particles from the slurry by one or more liquid/solid separation techniques.

Abstract: Method for the treatment of cellulosic pulp in which pulp is distributed upward through a vertical reactor using a unique conical distributor and is discharged using a unique dilution method to eliminate plugging. The system is particularly useful for delignifying virgin wood pulps or decolorizing pulps made from waste paper materials.

Abstract: A method of deinking printed waste paper for recycle which comprises converting a printed waste paper to a fibrous pulp in an aqueous medium to form a fibrous pulp slurry; contacting the slurry with a soybean peroxidase and a peroxide to deink the pulp; separating the deinked pulp from the aqueous medium; and recovering the deinked pulp.

Abstract: Disclosed is a method of deinking cellulosic materials comprising, shredding or chopping the cellulosic materials to create uniform paper shreds, immersing the paper shreds into a nonaqueous organic solvent while agitating the paper shreds, removing the organic solvent, bleaching the paper shreds to form a pulp, diluting said pulp to form a fiber suspension and submitting the suspension to high speed, high shear dispersion to form a pulp ready for papermaking.

Abstract: Waste cellulosic paper products, for example, old corrugated container are recycled employing oxygen delignification in the presence of an alkaline material to produce a recycled pulp of lower kappa number, while maintaining adequate strength in the pulp. The recycling process preferably employs an acid pretreatment in combination with the oxygen delignification, and exposure of the waste product to the alkaline material is preferably controlled so that at any point in the delignification the waste product is exposed to not more than 50%, by dry weight, of the alkaline material based on the weight of residual lignin in the waste paper product.

Abstract: A method is disclosed for the detackification of stickies in the production of recycled paper products containing secondary fibers. Oxygen is used to reduce the tackiness of stickies in secondary pulps, and optionally is used with alkali and/or detackification agents for optimum stickies control.

Abstract: Color is removed from secondary pulps with non-chlorine based bleaching agents in treating sequences using oxygen with combinations of peroxide, ozone, and/or hydrosulfite at/controlled pH conditions. Acid treatment prior to bleaching steps improves color removal and protects fibers from damage at more severe bleaching conditions.

Abstract: A process for the production of a papermaking filler product from the fiber fines/clay fraction of a pulp, paper, paperboard, or deinking mill waste solids such process comprising the reaction of said solids with sufficient acid to lower and maintain a pH of less than 5.0. Such process yields improvement in the drainage characteristics of the material. Bleach can be added or the pH raised back to neutral to further improve the specific resistance and/or brightness of the material.

Abstract: Color is removed from secondary pulps with non-chlorine based bleaching agents in treating sequences using oxygen with combinations of peroxide, ozone, and/or hydrosulfite at/controlled pH conditions. Acid treatment prior to bleaching steps improves color removal and protects fibers from damage at more severe bleaching conditions.

Abstract: A method of obtaining an excellent recycled pulp from waste pressure-sensitive adhesive paper which has previously been discarded. This method being characterized in that the waste paper is defiberized, then a defiberized suspension thereof is diluted, the diluted suspension is coarse screened by a screen having a slit width of below 0.5 mm, the pulp suspension after coarse screening is dewatered so as to have a solid matter consistency of 15 to 40% by weight, the dewatered stuff is mechanically agitated, the difference between the temperature of the stuff before the agitation and the temperature thereof after the agitation being below 12.degree. C., the obtained stuff is being diluted again, the diluted suspension is fine screened by a screen having a slit width of below 0.

Abstract: Waste cellulosic paper products, for example, old corrugated containers are recycled employing oxygen delignification in the presence of an alkaline material to produce a recycled pulp of lower kappa number, while maintaining adequate strength in the pulp. The recycling process preferably employs an acid pretreatment in combination with the oxygen delignification, and exposure of the waste product to the alkaline material is preferably controlled so that at any point in the delignification the waste product is exposed to not more than 50%, by dry weight, of the alkaline material based on the weight of residual lignin in the waste paper product.

Abstract: Process for producing pulp suitable as raw material for paper, board or fiberboards and similar products. A pumpable alkaline slurry of fibrous raw material is conducted through a pressurized tube system by the use of pulp pumps, the pressure increasing in steps from the beginning of the process to the end of the process. On its way the slurry is repeatedly dewatered and rediluted with process liquid. An apparatus suitable for being used in carrying out the process comprises a dewatering tube (64) and a dewatering and venting tube (67) arranged centrally and axially within the tube (64) which may be provided with a perforated part (66). The tube (67) is provided with perforations (68) through which gas and liquid from fiber-containing slurry introduced into the outer tube (64) can escape. At the opposite end from the inlet end of the outer tube (64) there is an outlet (72, 65) for thickened fiber-containing slurry.

Abstract: Process for color stripping and bleaching of colored waste paper by treatment by means of monoperoxysulphuric acid or of one of its salts, according to which the treatment is performed in the presence of a halide ion.

Abstract: A method for the deinking of recycled fibers, in which the macerated fibers are slurried with water; introduced to a deinking cell which has a central anode and a perimetal cathode; subjected to a direct current electric field applied between the anode and the cathode, causing the ink to be attracted away from the fibers and to electrocoagulate the ink then floating to the surface of the slurry with the aid of gas bubbles generated during the application of the electric field; and washed to recover a cleaner, brighter pulp of recycled fibers.

Abstract: Secondary pulp is deinked and bleached by contacting the pulp simultaneously with oxygen, alkali, and a surfactant in a reaction zone followed by washing to recover a secondary fiber product. Simultaneous contacting with oxygen and surfactant yields higher pulp brightness than sequential contacting in oxygen bleaching and washing stages, and enhances bleachability in further bleaching stages.

Abstract: A process for the recovery of fibers by means of flotation de-inking of waste paper which bears ink applied by flexographic printing or xerography, by reducing the paper to fibers in an aqueous medium with the addition of bleaching chemicals and auxiliaries containing peroxide, fatty acids, complexing agent, sodium hydroxide, and an additive based on polyglycol and a phosphoric ester mixture, produces fibers which are free from ink, which are useful as a recyclable material.

Abstract: The invention therefore relates to a process for the deinking of wastepaper stocks which comprises:a) converting the wastepaper to a pulp and contacting said pulp with an aqueous medium of alkaline pH containing a surface active deinking agent, andb) subjecting the resulting pulp-containing medium to one or more flotation steps wherein said final flotation step is carried out at a pH of less than about 7 to remove suspended ink therefrom and to condition said pulp-containing medium for subsequent addition to a paper machine.

Abstract: The invention relates to a process for the deinking of wastepaper stocks comprising converting the wastepaper to a pulp and contacting said pulp with an aqueous medium having a pH of about 7 or less containing a surface active deinking agent, and thereafter subjecting the resulting pulp-containing medium to one or more wash and/or flotation steps which is carried out at a pH of about 7 or less to remove suspended ink therefrom and to condition said pulp-containing medium for subsequent addition to a paper machine.

Abstract: According to the invention, wastepaper is refined in the presence of alkoxylation products obtainable by reaction of alkylene oxides with C.sub.10-22 carboxylic acid derivatives and/or C.sub.10-22 carboxylic acids containing carboxylic acid residues with at least one OH group in the 9, 10, 13 and/or 14 position and the detached printing ink particles are subsequently removed from the paper stock suspensions by flotation or washing.

Abstract: A method is disclosed for the detackification of stickies in the production of recycled paper products containing secondary fibers. Oxygen is used to reduce the tackiness of stickies in secondary pulps, and optionally is used with alkali and/or detackification agents for optimum stickies control. The preferred alkali source is fully oxidized white liquor.

Abstract: Color from dyes is removed from secondary pulps with non-chlorine based bleaching agents in treating sequences using oxygen with combinations of peroxide, ozone, and/or hydrosulfite at controlled pH conditions (less than 8 or greater than 10). Acid treatment prior to bleaching steps improves color removal and protects fibers from damage at more severe bleaching conditions.

Abstract: In apparatus and methods for preparing deinked paper making stock, the initially pulped and cleaned stock is fractionated by filtering through a continuously moving mesh belt of a predetermined mesh size which will retain substantially all of the fibers of greater than a predetermined length as a first suspension fraction and a second suspension fraction comprising the majority of the liquid component of the feed suspension along with small contaminant particles and the remaining fines. These two fractions are then treated separately by bleaching the first fraction and recovering the fines from the second fraction, after which the fines and the first fraction are recombined for further treatment and use.

Abstract: The present invention relates to a method of removing ink from secondary fiber by contacting a pulp of said secondary fiber with an aqueous medium in the presence of a polymeric material having a glass transition temperature in the range of from about 20.degree. C. to about 70.degree. C. and a substituted polyethylene oxide to agglomerate the ink into discrete masses and separating the agglomerated ink from the pulp-containing aqueous medium.

Abstract: A process for the production of chlorine dioxide by reacting in a reaction vessel an alkali metal chlorate, mineral acid and a reducing agent in such proportions that chlorine dioxide is produced in a reaction medium which is maintained at a temperature of from about 50.degree. C. to about 100.degree. C. and at an acidity within a range of from about 2 to about 5N. The reaction medium is subjected to subatmospheric pressure sufficient for evaporating water, a mixture of chlorine dioxide, oxygen and water vapor being withdrawn from an evaporation zone in the reaction vessel, and alkali metal sulfate being precipitated in a crystallization zone in the reaction vessel. As the reducing agent hydrogen peroxide is used.

Abstract: A process for the production of chlorine dioxide by reacting in a reaction vessel an alkali metal chlorate, mineral acid and a reducing agent in such proportions that chlorine dioxide is produced in a reaction medium which is maintained at a temperature of from about 50.degree. C. to about 100.degree. C. and at an acidity within a range of from about 5N to about 11N. The reaction medium is subjected to subatmospheric pressure sufficient for evaporating water, a mixture of chlorine dioxide, oxgen and water vapour being withdrawn from an evaporation zone in the reaction vessel, and alkali metal sulfate being precipitated in a crystallization zone in the reaction vessel. As the reducing agent hydrogen peroxide is used.

Abstract: A process is described in which, by the addition of formamidinesulfinic acid in association with an ozone or ozone/oxygen treatment, the viscosity and strength of wood pulps are stabilized at the level that is obtained with use of conventional, chlorine-containing bleaching processes.

Abstract: The bleaching chemicals are added to the pulp immediately after heating of the raw pulp thickened to more than 20% by weight and immediately prior to a dispersing process. This is carried out in a high-speed, high-efficiency disperser, where the heated, thickened pulp is forced through a plurality of narrow slits in a disperser lining and is exposed to strong shearing, impact and kneading stresses. In this way, the dispersing process is reduced to a time period less than 3 seconds, preferably about 1 second or less. As a result, the total time required for reductive bleaching is reduced to less than 15 seconds and no further measures are required for displacing and excluding air from the system. The method can also be advantageously used with oxidative bleaching at reduced reaction time requirements. A high dispersing temperature in the region of 40.degree. C. to 110.degree. C., preferably about 95.degree. C.