Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/34—Paper
  • G01N33/343—Paper pulp
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
  • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
  • G01N21/64—Fluorescence; Phosphorescence
  • G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
  • G01N2021/6439—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" with indicators, stains, dyes, tags, labels, marks

Definitions

• the invention relates to a method for the determination of hydrophobic organic particles in the filtrate of a paper stock.
• Impurity particles are mostly hydrophobic and sticky. They come z. B. from recycled waste paper and lead in the papermaking process to deposits in the machinery.
• metering fixer to the pulp. This ensures that the contaminants are bound to the cellulose fibers and deposits in the machines are largely avoided.
• the respectively required amount of fixer is then determined by means of an analysis of the paper stock or white water on Störstoffteilchen.
• a measuring method for determining the number and size of resin particles in a pulp wherein initially preparing a paper stock suspension, the resin particles separated by filtration, the resin particles marked with a fluorescent dye, then separated, for light emission stimulates, detects the light signals and evaluates the signals for counting and sizing of the resin particles.
• the fluorescent dye used is N- (n-butyl) -4- (n-butylamino) -naphthalic acid imide.
• a method for determining the size distribution of at least two particle types (A K ) of fluorescent particles (T 1) in a single sample the particles (T 1) in the sample being singulated and light is irradiated into the specimen along a predetermined irradiation direction, at least one scattered light intensity value (S (T,)) and at least one fluorescent light intensity value (F (T,)) of each particle (T,) is measured, the particles (T,) due to the position of their value pairs (S (T,), F (T,)) in a region (BK) in a three-dimensional space (R), which is calculated from the scattered light intensity values (S (T,)), the fluorescence light intensity values (F (T 1 )) and the frequency of the pairs of values (S (Ti) 1 F (T 1 )) are assigned, each of a particle (A K ) are assigned, each region (BK) at least one local maximum of the frequency of the value pairs (S (Ti )
• This method is used in particular for determining the particle size distribution of hydrophobic contaminant particles in the paper stock or in the white water of papermaking machines and used to control the metering of fixing agents to the paper stock by generating a control signal corresponding to the common relative particle size distribution and reducing the metering necessary Fixierffenmenge is made due to this control signal.
• WO 06/122921 discloses a method for determining the sizing concentration, the particle size and the particle size distribution of natural and / or synthetic sizing agents in a paper stock, wherein a sample, contains the sizing agent particles, stains with a fluorescent dye, which separates particles in the sample, irradiates light and detects the scattered light and / or fluorescent light emitted by the sample and evaluates the received signals.
• the method is used to determine the particle size distribution of reactive sizing agents in the stock or in the white water of paper machines during papermaking.
• the particles to be determined are always isolated.
• the single particle count is expensive.
• the invention has for its object to provide a different measurement method for the determination of the mass concentration of hydrophobic particles in a filtrate of a pulp available.
• the object is achieved according to the invention by a method for determining the concentration of hydrophobic organic particles in the filtrate of a paper stock, wherein the hydrophobic organic particles are marked with a fluorescent dye, then excited to emit light, the light emitted by the labeled particles is detected and the fluorescence intensity determines the mass concentration of the particles.
• Hydrophobic organic particles are, for example, the finely divided impurities present in a pulp, such as stickies, white pitch and resin, and sizing agents.
• the impurities consist essentially of dispersed hydrophobic materials, which are, for example, residues of binders of paper coating slips or adhesives.
• the particle size of the impurities is for example 0.5 to 100 microns.
• Suitable sizing agents are natural and / or synthetic sizing agents, for.
• the sizing agents are compounds which are dispersed in water and, for example, have particle sizes in the range of 0.5 to 100 ⁇ m, preferably 1 ⁇ m to 20 ⁇ m.
• alkyl diketenes (AKD) and alkenyl succinic anhydrides. They are used as engine sizing agents in the manufacture of paper, board and cardboard. These substances are essentially C 1 -C 22 -alkyldiketenes, such as stearyldiketene, palmityldiketene, behenyldicene, oleyldiketene and mixtures of diketenes. They are prepared, for example, by emulsification in water in the presence of cationic starch and an anionic dispersant under the action of shearing forces, cf. US 3,223,544 and US 3,130,118. Due to an excess of cationic starch over the anionic dispersants, the AKD dispersions thus prepared have a cationic charge.
• Alkyl diketenes can also be used together with other sizing agents.
• aqueous, anionically adjusted AKD dispersions are known, which are obtainable, for example, by dispersing AKD in water in the presence of anionic dispersants as the sole stabilizer, cf. WO 00/23651.
• Polymer sizing agents are described, for example, in JP-A 58/1 15 196, EP-B 0 257 412 and EP-B 0 276 770. These are essentially aqueous dispersions of copolymers prepared in the presence of starch or degraded starch become. Suitable copolymers are, for example, copolymers of styrene and / or acrylonitrile and acrylic acid esters.
• Alkenyl succinic anhydrides are also used in the manufacture of paper and paper products as engine sizing agents in the art.
• sizing agents are the isomeric 4-, 5-, 6-, 7- and 8-hexadecenylsuccinic anhydrides, decenylsuccinic anhydride, octenylsuccinic anhydride, dodecenylsuccinic anhydride and n-hexadecenylsuccinic anhydride, cf. also C.E. Farley and R.B. Wasser, The Sizing of Paper, Second Edition, (3), Sizing With Alkenyl Succinic Anhydride, TAPPI PRESS, 1989, ISBN 0-89852-051-7.
• Suitable natural sizing agents are rosin size and chemically modified resin finishes, cf. E. Strazdins, Chapter 1, “Chemistry and Application of Rosin Size” in WF Reynolds (Ed.), “The Sizing of Paper,” Second Edition, Tappi Press (Atlanta, USA), 1989, pp. 1-31 (ISBN 0 -89852-051-7).
• the measurements for the integral quantitative determination of hydrophobic particles are carried out, for example, in a fluorescence spectrophotometer.
• a fluorescence spectrophotometer from Hitachi was used (Hitachi F4010).
• Clear samples with low intrinsic extinction are preferably measured in a 90 ° arrangement in which the excitation light is incident perpendicular to the wall of the cuvette in which the sample to be examined is located. The emitted light is measured at an angle of 90 ° to the excitation light.
• the excitation light strikes the cuvette at an angle of, for example, 45 ° and the reflection light is radiated from the sample at an angle of 90 ° to the excitation light and analyzed. The reflection light is hidden.
• the samples containing contaminants and / or a sizing agent are stained with at least one fluorescent dye.
• Suitable dyes include:
• N- (n-butyl) -4- (n-butylamino) -naphthalic acid imide (Fluorol 7GA), Color Index dye (Cl.) Number 40662 (Celluflor), dye of Cl. Number 45400 (eosin B), 3,3-ethyloxydicarbocyanine iodide,
• a particularly preferred fluorescent dye is N- (n-butyl) -4- (n-butylamino) -naphthalic acid imide.
• the filtrate of a pulp also contains cellulose fibers and optionally inorganic pigments. These substances are not stained by the fluorescent dyes, so they do not interfere with the measurement.
• it takes an exposure time of, for example, 2 to 14 minutes, preferably 2 to 5 minutes.
• it is advantageous to set a specific reaction time for the dyeing time, for example 5 minutes.
• a solution of at least one fluorescent dye in ethanol In order to color the samples to be examined, it is preferable to use a solution of at least one fluorescent dye in ethanol.
• concentration of fluorescent dye dissolved in ethanol is, for example, 10 to 40 mg / L.
• concentration of impurities and / or sizing agents is for example 0 to 20 mg / l.
• the measuring method according to the invention is particularly suitable for rapid tests in order to determine the effectiveness of process chemicals.
• the method of measurement is therefore used to determine the total concentration of hydrophobic organic particles in the filtrate of a paper stock dewatered on a sieve. It is particularly suitable as an online measuring method in the papermaking process.
• a well-known contaminant control agent is z.
• the impurities are bound, for example, by the added teilhydrolystechnischylfomamid to the cellulose fibers.
• a Sticky system of 8 g / l TMP groundwood and 0.16 g / l Styronal ® D718 (aqueous dispersion of a binder based on styrene and butadiene) was prepared by placing 500 ml of this mixture in a beaker, and 5 ml of a hydrolyzed polyvinylformamide having a degree of hydrolysis of 83% and a K value of 61 as a fixing agent added.
• the K value was determined according to H. Fikentscher, Cellulose-Chemie, Vol. 13, 58-64 and 71-74 (1932) in 5% aqueous common salt solution at a temperature of 25 ° C.
• the irradiated light had a wavelength of 442 nm, the fluorescence intensity was measured at 500 nm.
• the evaluation was carried out on the basis of a previously recorded calibration curve for the corresponding Sticky system for concentrations of 0 to 0.05 g / l ® Styronal D718. As sticky content in the filtrate a concentration of 0.01 g / l Styronal D718 was determined. This value corresponds to a retention of Styronal D718 ® to TMP-pulp of 93.7%.

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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
• Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
• Paper (AREA)

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• 2008
  • 2008-02-28 EP EP08717202A patent/EP2126561B1/de not_active Revoked
  • 2008-02-28 CN CN200880006638A patent/CN101622536A/zh active Pending
  • 2008-02-28 AT AT08717202T patent/ATE553375T1/de active
  • 2008-02-28 PT PT08717202T patent/PT2126561E/pt unknown
  • 2008-02-28 PL PL08717202T patent/PL2126561T3/pl unknown
  • 2008-02-28 CA CA002679179A patent/CA2679179A1/en not_active Abandoned
  • 2008-02-28 ES ES08717202T patent/ES2384667T3/es active Active
  • 2008-02-28 JP JP2009551203A patent/JP2010520444A/ja active Pending
  • 2008-02-28 WO PCT/EP2008/052400 patent/WO2008104576A1/de not_active Ceased
  • 2008-02-28 US US12/527,509 patent/US20100012284A1/en not_active Abandoned

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