Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/36—Coatings with pigments
  • D21H19/38—Coatings with pigments characterised by the pigments
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/63—Inorganic compounds
  • D21H17/70—Inorganic compounds forming new compounds in situ, e.g. within the pulp or paper, by chemical reaction with other substances added separately
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/63—Inorganic compounds
  • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
  • D21H17/675—Oxides, hydroxides or carbonates

Definitions

• the invention relates to a method for the preparation of fibers contained in a fiber suspension and / or for the preparation of coating color for coated papers.
• PCC precipitated calcium carbonate
• GCC ground calcium carbonate
• PCC or GCC fillers are mass-produced goods that are produced in special manufacturing companies that can be assigned to a paper mill as a satellite system.
• online production of PCC has never been considered in the paper industry due to the particular process properties required to produce PCC. Instead, PCC or GCC is transported to the paper mills in bulk or in the form of a suspension.
• PCC and GCC fillers are used as coating pigments in sizes of 0.3 m and above. Since the small particles of GCC fillers do not have the required optical properties, Ti0 2 is added.
• Ti0 2 can be achieved, which, however, is a very expensive and abrasive pigment that is up to 10 times as expensive as the PCC or GCC pigments can be. Since the optical properties of the currently used GCC and PCC pigments are limited due to the manufacturing process, Ti0 2 has been used to improve these properties.
• Fiber Loading with an additive e.g. Filler
• an additive e.g. Filler
• a chemical precipitation reaction i.e. in particular by means of a so-called "Fiber Loading TM” process, as described, inter alia, in US Pat. No. 5,223,090.
• at least one additive, in particular filler is embedded on the wetted fiber surfaces of the fiber material.
• the fibers can be loaded with calcium carbonate, for example.
• calcium oxide and / or calcium hydroxide is added to the moist, disintegrated fiber material in such a way that at least a part thereof is associated with the water present in the fiber material.
• the fiber material treated in this way is then subjected to carbon dioxide.
• the calcium hydroxide medium When the calcium oxide and / or the calcium hydroxide medium is added to the fiber suspension, a chemical reaction with an exothermic property takes place, the calcium hydroxide preferably being added in liquid form (milk of lime). This means that the water which is possibly stored in or on the fibers of the fiber suspension is not absolutely necessary for the start and completion of the chemical reaction.
• the aim of the invention is to provide an improved method of the type mentioned in the introduction.
• At least one of the following devices and / or means can be used for the online process: cleaning device, in particular HC cleaner, co-cleaning device, in particular static mixer, lime quenching device, press, in particular screw press or belt press, compensating reactor, crystallizer, further mixing device, in particular static Mixer, C0 2 supply device or additional C0 2 recovery device, optional C ⁇ 2 heater, optional chemical bleach additive, pressurized water tank.
• cleaning device in particular HC cleaner, co-cleaning device, in particular static mixer, lime quenching device, press, in particular screw press or belt press, compensating reactor, crystallizer, further mixing device, in particular static Mixer, C0 2 supply device or additional C0 2 recovery device, optional C ⁇ 2 heater, optional chemical bleach additive, pressurized water tank.
• crystalline precipitation product particles has the advantage, among other things, that, if necessary, higher gloss values can be achieved for the end product.
• the coating color is usually not ground, but it can be ground. In general, this depends on the respective definition, but also on the respective crystallization process. If CaCO crystals are produced in the coating kitchen, there are no fibers in the suspension, which means that the pump crystallizer only works as a highly efficient chemical reactor or mixer. Of course, you could also see a grinding component in the mixing and reaction process, especially due to the friction of the particles in the suspension, supported by the rotor and the stator.
• the first mixing device is preferably used for mixing the milk of lime into the fiber suspension.
• the cleaning device is used to prevent contamination by heavier materials such as, in particular, sand, stones and pieces of metal occurring during the process.
• At least part of the required CO 2 is provided by a CO 2 recovery system.
• a CO 2 recovery system can be recovered from the flue gas from boilers or the flue gas from power plants.
• milk of lime the calcium hydroxide preferably being added in liquid form
• fall product particles of a rhombohedral shape with a respective cube size in a range from approximately 0.05 to approximately 2 ⁇ m can be produced.
• the solids concentration of the fiber suspension provided is selected in a range from approximately 5 to approximately 60% and preferably in a range from approximately 10 to approximately 35%.
• calcium carbonate (CaC0 3 ) can be stored on the wetted fiber surfaces by using the moist fiber material calcium oxide (CaO) and / or calcium hydroxide (Ca (OH) 2 ) is added, at least a part of which can be associated with the water of the amount of fiber.
• the fiber material treated in this way can then be subjected to carbon dioxide (C0 2 ).
• dry fiber surfaces can encompass all wetted surfaces of the individual fibers.
• the case is also included in which the fibers are loaded with calcium carbonate or any other precipitation product both on their outer surface and in their interior (lumen).
• the fibers may e.g. are loaded with the filler calcium carbonate, the attachment to the wetted fiber surfaces being carried out by a so-called "Fiber Loading TM" process as described as such in US Pat. No. 5,223,090.
• this "Fiber Loading TM” process e.g. the carbon dioxide with the calcium hydroxide to water and calcium carbonate.
• the calcium hydroxide can be added to the fiber suspension in liquid form or in dry form.
• the carbon dioxide is added to the fiber suspension at a temperature in a range from approximately -15 to approximately 120 ° C. and preferably in a range from approximately 20 to approximately 90 ° C.
• the paper produced can therefore contain fillers in a range from about 0.05 to about 5 ⁇ , which increases the optical properties of the end product.
• the filler can in particular be calcium carbonate, which occurs in nature, for example, as caicit or calcite, aragonite and in the rarer form fatherite.
• the filler can mainly consist of the form of caicit, of which over 300 different crystal forms are said to exist.
• the shape of the filler particles used can be, for example, rhombohedral with a respective cube size in a range from about 0.05 to about 2 ⁇ m or for example, be scalenohedral with a respective length in a range from approximately 0.05 to approximately 2 ⁇ m and a respective diameter in a range from approximately 0.01 to approximately 0.05 m, depending on the type of paper to be produced in each case.
• the filler is well distributed on, around and within the fibers, which means that there is no agglomeration of crystals in bundles.
• the respective filler particle namely the crystal, is individually spaced or isolated on the fiber.
• the filler particle covers the fiber by being attached to the fiber, which improves the optical properties of the end product.
• the particle size is therefore essential for achieving optimal opacity. A high opacity is achieved when the color spectrum of the visible light is well scattered. If the color spectrum is absorbed, the color is black. If the size of the filler particles falls below 0.2 to 0.5 ⁇ m, there is a tendency towards transparency and higher gloss.
• the manufacturing process in question for producing the filler crystals can be designed, for example, as follows and have the following variables:
• the fiber suspension previously mixed with Ca (OH) 2 is placed in a fluffer, refiner, disperser or the like at a consistency or solids concentration in a range from about 5 to about 60%, preferably in a range from about 10 to about 35%.
• the Ca (OH) 2 can be added in liquid or dry form.
• the fiber suspension is loaded with C0 2 .
• the C0 2 can e.g. B. at temperatures in a range between about - 15 and about 120 ° C and preferably at temperatures in a range between about 20 and about 90 ° C.
• the fibrous suspension enters the gas zone, where each individual fiber is exposed to a gas atmosphere, followed by the precipitation reaction, which immediately results in the CaC0 3 .
• the shape of the CaC0 3 crystals can be, for example, rhombohedral, scalenohedral or spherical, the amount of crystal in particular being dependent on the temperature range selected for the fiber suspension and on the C0 2 and the Ca (OH) 2 content in the fiber suspension.
• a shear distribution occurs which brings about a size distribution of the crystals of about 0.05 to about 0.5 ⁇ m and preferably from about 0.3 to about 2.5 ⁇ m.
• the shape of the filler particles used is, for example, rhombohedral with a respective cube size in a range from about 0.05 to about 2 / ⁇ m or scalenohedral with a respective length in a range from about 0.05 to about 2 ⁇ m and a respective diameter in one Range from about 0.01 to about 0.5 ⁇ m, depending on the type of paper to be made.
• the concentration of the fibrous suspension passing through the rotor disk is about 0.1 to about 50% and preferably about 35 to about 50% ,
• the pressure acting on the CO 2 supply line is in particular in a range from approximately 0.1 to approximately 6 bar, and preferably in a range from approximately 0.5 to approximately 3 bar, in order to provide a constant CO 2 supply to the gas ring for the desired one to ensure chemical reaction.
• the pressure must be increased when there is a high water requirement in order to pump more through the hose.
• the C0 2 is a compressible gas, the amount required can also be increased to ensure a complete reaction.
• the C0 2 supply and thus the CaC0 3 producing precipitation reaction can be controlled and / or regulated via the pH.
• pH values in a range from 6.0 to approximately 10.0 pH, preferably in a range from approximately 7.0 to approximately 8.5 pH, can be envisaged for the final reaction of the CaCO 3 crystals.
• the energy used for this process can in particular be in a range between approximately 0.3 and approximately 8 kWh / t and preferably in a range between approximately 0.5 and approximately 4 kWh / t.
• Dilution water can be added and mixed with the pulp suspension to obtain a final dilution in which the pulp suspension produced with filler has a consistency or solids concentration in a range from, for example, about 0.1 to about 16%, preferably in a range from about 2 to owns about 6%.
• the pulp suspension is then exposed to the atmosphere in a machine, a container or the next process machine.
• the rotational speed of the rotor disk can be on the outside diameter, in particular in a range from approximately 20 to 100 m / s and preferably in a range from approximately 40 to approximately 60 m / s.
• the gap between the rotor and the stator is, for example, approximately 0.5 to approximately 100 mm and preferably approximately 25 to approximately 75 mm.
• the diameter of the rotor and the stator can in particular be in a range from approximately 0.5 to approximately 2 m.
• the reaction time is preferably in a range from approximately 0.001 to 1 min, preferably in a range from approximately 0.1 to approximately 10 seconds.
• the method described above enables individual particles to be produced which are equally spaced apart and attached to the fibers, covering the fibers in the manner required to meet the requirements for the desired high level of white or glossy paper.
• the particle size is preferably in a range from about 0.05 to about 5 ⁇ m, the preferred size for the rhombohedral shape of a cube in one Range from about 0.05 to about 2 ⁇ m or for a scalenohedral shape with respect to the length in a range from about 0.05 to about 2 ⁇ m and with respect to the diameter in a range from about 0.01 to about 0.5 ⁇ m lies.
• the particle size should expediently be below 0.2 to 0.5 ⁇ m.
• a new way of storing pigments is created in order to achieve the desired optical properties and the desired printability in and on the paper sheet directly during the paper production and not during the coating process.
• the coating process can therefore only be provided for fine adjustment of the properties of the paper surface.
• a corresponding influencing in the coating process is also conceivable.
• Ti0 2 can be reduced after a higher degree of whiteness and better optical properties can be achieved.
• the method according to the invention can also be used in particular for coating color for coated papers.
• PCC production can be part of the coating process, and the crystal forms mentioned can be formed again.
• the wear in the coating device and in the paper machine is reduced if there is an online deletion. Accordingly, the method according to the invention can in particular also be used in combination in a coating machine and a paper machine.
• Wood-containing or wood-free coated printing and writing papers - Uncoated wood-containing or wood-free printing and writing papers.
• Types of paper determined by wood pulp or cellulose are known in the art.
• woody paper with wood or pulp in a range from 25% to 100%.
• Chemical pulp is added to increase the strength and runnability of coating and paper machines, etc.
• TMP Thermomechanical Pulp
• SC paper This is a type of paper that is determined by the use of chemical pulp and can have a filler content of up to 30%.
• Chemical pulp types - These contain mechanical pulp up to 10%. Both hardwood and softwood chemical pulps are used.
• This consists of up to 90 to 100% of new chemical pulp fibers, but can contain recycled fibers up to 100%, whereby a filler content up to about 30% can be provided.
• Cardboard types - These contain a top layer made from a mixture of bleached
• Hardwood up to 90%
• bleached softwood up to 30%
• the middle layer contains, for example, a mixture of waste and production waste
• the base layer can contain unbleached softwood and production waste as well as OCC.
• the method according to the invention can be implemented, for example, in a "Fiber Loading TM" system of the type shown in the single figure of the drawing.
• cleaning device 10 in particular HC cleaner (high consistency cleaner), mixing device 12, in particular static mixer, lime quenching device 14, press 16, in particular screw press or belt press, compensating reactor 18, crystallizer 20, further mixing device 22, in particular static mixer, CO 2 supply device 24 or additional CO 2 recovery device, optional CO 2 heater 26, optional chemical bleach additives, pressurized water tank 28.
• the cleaning device 10 or an equivalent device preferably equipped with at least one mechanism that effects a protective function.
• the mixing device 10 and the further mixing device 22 can also be designed in accordance with the devices for mixing suspended fibrous material disclosed in German Offenlegungsschrift DE 41 25 513 A1.
• a device comprises an introduction line for a suspended fibrous material ("thick material") which opens into the wall of a pipe section, in particular a curved one, which carries a thin material.
• the outflow velocity of the thick matter from the inlet line is preferably at least three times the velocity of the thin matter flowing in the mouth area.
• the inlet line preferably opens into the central area of the pipe section.
• the mixing device 10 and / or the further mixing device 22 can be equipped with or without a known indwelling chest.
• control valve 28 provided in a line to the cleaning device 10, one between the lime quenching device 14 and the
• the first mixing device 12 provided lime pump 30, a press water pump 32 provided between the press water tank 28 and the crystallizer 20, a mixing tank 34 as well as a C0 2 pump 36 provided between the C0 2 supply 24 and the C0 2 heater 26.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Paper (AREA)
• Inorganic Fibers (AREA)
• Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

Priority Applications (7)

Applications Claiming Priority (4)

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Publications (1)

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Cited By (2)

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Citations (7)

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• 2003
  • 2003-02-03 EP EP03737300A patent/EP1474568A1/de not_active Withdrawn
  • 2003-02-03 AU AU2003244495A patent/AU2003244495A1/en not_active Abandoned
  • 2003-02-03 EA EA200401018A patent/EA006451B1/ru not_active IP Right Cessation
  • 2003-02-03 CN CNB038030357A patent/CN100363554C/zh not_active Expired - Fee Related
  • 2003-02-03 WO PCT/EP2003/001019 patent/WO2003066962A1/de active Application Filing
  • 2003-02-03 CA CA002474933A patent/CA2474933A1/en not_active Abandoned
  • 2003-02-03 JP JP2003566299A patent/JP2005517100A/ja active Pending
  • 2003-02-03 MX MXPA04007332A patent/MXPA04007332A/es unknown
• 2004
  • 2004-08-02 US US10/909,618 patent/US20050000665A1/en not_active Abandoned

Patent Citations (8)

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