EP0807698B1 - Procédé et dispositif pour la préparation d'une structure fibrillaire à base de dérivés de cellulose - Google Patents

Procédé et dispositif pour la préparation d'une structure fibrillaire à base de dérivés de cellulose Download PDF

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Publication number
EP0807698B1
EP0807698B1 EP97106492A EP97106492A EP0807698B1 EP 0807698 B1 EP0807698 B1 EP 0807698B1 EP 97106492 A EP97106492 A EP 97106492A EP 97106492 A EP97106492 A EP 97106492A EP 0807698 B1 EP0807698 B1 EP 0807698B1
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Prior art keywords
dope
solvent
fibrets
process according
precipitation
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German (de)
English (en)
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EP0807698A3 (fr
EP0807698A2 (fr
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Heinz-Joachim Müller
Rüdiger Leibnitz
Udo Holzki
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Pall Filtersystems GmbH
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Seitz Schenk Filtersystems GmbH
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    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00—Formation of filaments, threads, or the like
    • D01D5/40—Formation of filaments, threads, or the like by applying a shearing force to a dispersion or solution of filament formable polymers, e.g. by stirring
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00—Formation of filaments, threads, or the like
    • D01D5/18—Formation of filaments, threads, or the like by means of rotating spinnerets
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
    • D01F2/24—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from cellulose derivatives

Definitions

  • the invention relates to a method for producing fibrets according to the Preamble of claim 1 and a device according to the Preamble of claim 21.
  • Fibrets are understood in the following as very fine fibers, which are characterized by very fine fiber diameters and thus by a very high mass-specific surface. Fibrets are typically produced by means of a precipitation process or by extrusion, in which case precipitation is usually integrated as a sub-process. Fibrets are partly present in the fiber composite or fiber network as a result of the production: the diameters of the individual fibers are generally less than 5 ⁇ m, mostly less than 1 ⁇ m.
  • the dimensions of the fiber networks which are referred to as agglomerates and which can be varied over a wide range by the conditions during production and by further processing steps, are up to 1 mm. However, agglomerate sizes of less than 200 ⁇ m are aimed for. With the dimensions mentioned, mass-specific surfaces of over 20 m 2 / g are achieved.
  • the fibrets are mainly used in depth filters Liquid filtration is provided, these filters also used to detect the achieved quality of the fibrets can be used.
  • Depth filtering is critical, small pore sizes with high porosity to realize. In terms of filtration technology, this results in high separation achieved low differential pressures.
  • Embedding the fibrets in Fiber networks have cut short of particulate material Staple fibers also have the advantage that the fibers in the filter are very firm are involved and thus detachments as far as possible during the filtration can be excluded.
  • the fiber structure in the agglomerate composite gives the filters a high strength with flexibility, what pleating is an advantage.
  • fibrets are not on depth filters for liquid filtration limited.
  • nonwovens for air filtration fibrets can, for example Replace glass fibers, their harmful effects when entering the Lung is known.
  • fibrets can be used as optical brighteners used in the paper industry. Small amounts remaining Solvents can cause the fibers to fuse during the process Carry out drying so that e.g. the strength is essential in nonwovens can be increased.
  • the Fibrets Due to the large specific surface, the Fibrets can be largely accessible to a medium flowing through advantageous for adsorption processes, including the Chromatography processes can be used. This effect can be achieved through the Introduction of surface-active substances or by a chemical Modification of the starting material before the fibret production or in subsequent production process are supported.
  • Fibrets can generally be made from a variety of materials. The only limits are set by the solvent and the viscosity of the solution. As a result of their advantages in the choice of the solvent, fibrets made of cellulose esters, in particular cellulose acetate, with mass-specific surfaces over 20 m 2 / g have mainly been presented in the literature. For use in depth filters for liquid filtration, fibrets made of cellulose acetate also have the advantage that, together with the pulp pulp that is used anyway, extensive material homogeneity is achieved. This ensures problem-free disposal. Compared to the currently preferred diatomaceous earth, perlites and / or metal oxides, the advantages of the very low ion emission and the complete biodegradability must be emphasized.
  • the production of fibrets from cellulose esters with solvents is basically e.g. from US 3,342,921, US 3,441,473, US 3,785,918, US 3,842,007, US 3,961,007, US 4,040,856, US 4,047,862, US 4,192,838, US 5,071,599 and US 5,175,276 known.
  • a solution (Dope) from a cellulose ester and a suitable solvent manufactured The non-solvent for the cellulose ester that comes with the Solvents that are completely miscible can be present in such proportions be that the dissolving behavior of the cellulose ester in the solvent is not significantly affect.
  • This solution is mostly under the influence of Shear forces in a non-solvent or precipitant for the Cellulose ester precipitated, which is completely miscible with the solvent.
  • the fibrets produced dampen the turbulence to a great extent, since the distance between the extrusion opening and the wall of 1.6 mm is only insignificantly larger than the maximum agglomerate size of 1 mm, so that solids contents exceeding 1% by mass ( % By weight) cannot therefore be exceeded after the precipitation. Since the turbulence is increasingly dependent on the solids content, the stirring arrangement has poor part-load behavior. Furthermore, the exit velocity of the dope is influenced by the centrifugal forces because the extrusion nozzles are arranged in the rotating disk. This also affects the precipitation conditions.
  • Two-component nozzle systems such as those in US 4,192,838, US 5,071,599 and U.S. 5,175,276 and the T-pipe systems described e.g. in the US 3,961,007, implement a similar principle.
  • the Precipitation occurs with regard to the flow directions of dope and precipitation medium with two-component nozzles in direct current, with T-pipe systems in contrast in Countercurrent realized.
  • the Nozzle diameters - usually> 2.5 mm - are designed to be as large as one Avoid solution failure at the nozzle opening.
  • the Nozzle diameter is 20,000 times larger than the required Fiber diameter.
  • the countercurrent process in the T-pipe systems is regarding Vortex formation and thus the shear field formation is the more effective variant.
  • the precipitation bath flow is braked very strongly, so that the Precipitation conditions vary widely.
  • the meet the aforementioned requirements is the formation of coarser fibers, especially with solids contents after the precipitation of approx. 1 Ma%, not too avoid.
  • a disadvantage of the known manufacturing process is that large quantities Solvents must be circulated.
  • Solvents For example in US 5,071,599 and US 5,175,276 for the production of 1 kg Fibrets called 8 kg of solvent, e.g. acetone.
  • solvent e.g. acetone.
  • US 3,842,007 and US 3,961,007 are for example for 1 kg of fibrets between 20 and 80 kg or 33 kg of solvent, such as acetone, 1,4-dioxane or methyl acetate is required.
  • the amount of solvent remaining in the fibrets is too high for further processing in most applications.
  • the fibret surface is not fully hardened due to the solvent contained in the solution.
  • the network structure is partially lost when pressure is applied, which leads to clumping at high pressures. For this reason, it is usually filtered under the action of shear forces, with solids contents of at most 4% by mass being achieved with specific surfaces of over 20 m 2 / g.
  • fibrets to solvent are in a ratio of about 1: 1, otherwise the solvent predominates.
  • a device for producing fibrils is known from US Pat. No. 4,237,081 Known olefins, which works on the rotor-stator principle.
  • the polymer solution is heated to temperatures above 100 ° C and central to the dispersion device fed.
  • the fiber is produced by cooling the polymer solution in a shear field, for which a coolant is off-center at several points between is fed to the sprockets.
  • the object of the invention is a method and an apparatus to provide an economical production of the fibrets Cellulose derivatives with better quality allowed.
  • the invention is based on the knowledge that a workup of the Fibrets separated components of the precipitation bath only make sense and is economical if the precipitating agent used for the precipitation bath is one may have the highest possible proportion of solvent and if one at the same time, the separated solvent fraction allows for the batch of the dope is reused, still have a non-solvent content can.
  • too high a proportion of non-solvent can a premature precipitation and on the other hand too high a viscosity of the Lead dope.
  • Dispersing device can be carried out according to the rotor / stator principle, if dope and precipitant are fed centrally into the dispersing device become.
  • Such dispersing devices are e.g. from the company Ystral under the name “dispersing machine” and from the company IKA Mechanical engineering sold under the name “Dispax-Reaktor".
  • This Devices usually contain two to six shaving rims, which are preferred alternately designed as stators and rotors. Reach the rotors Speeds up to 12000 revolutions per minute, so that in the precipitation bath Base flow speeds of up to preferably 100 m / sec can be achieved can.
  • the suspension formed from dope and precipitant at least in the shear field accelerated once, preferably at least twice alternately and is delayed, there is a high medium degree of turbulence over a long distance maintained so that a high viscosity dope can be processed.
  • the suspension is alternately preferably a radial and Subject to cross flow.
  • the dope is preferably introduced into the precipitant through stationary nozzles initiated, in front of their outlet openings means for generating a flow be moved past.
  • the dope is preferably prepared with cellulose esters or cellulose ethers.
  • Preferred are cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, Cellulose acetate propionate, benzyl cellulose or ethyl cellulose and others suitable cellulose derivatives or mixtures of these materials.
  • the proportion of cellulose derivatives in the dope is preferably 3 - 20% by mass. Lower concentrations are usually not economically attractive, larger proportions result in too high a viscosity.
  • Acetone can be used as the solvent.
  • Acetic acid methyl acetate, methyl ethyl ketone, 1,4-dioxane, acetaldehyde.
  • Ethyl acetate, tetrahydrofuran or methyl isopropyl ketone or mixtures of the solvents mentioned become.
  • the solvent acetone is particularly preferred.
  • the maximum non-solvent content based on the ratio Solvent for cellulose derivative depends on the precipitation point. The The higher the non-solvent content, the faster the precipitation point is reached is in the dope. The maximum salary is determined by the Precipitation point, which among other things is temperature-dependent. A is preferred Non-solvent content of 2 - 20% by mass below the concentration of the non-solvent at the respective precipitation point. In contrast to are in US 5,071,599 and US 5,175,276, the two-fluid nozzle systems describe, only up to 20% by weight of non-solvent permitted in the dope, see above that this proportion in the system cellulose acetate, acetone and water between 8.5% and 21% below the precipitation point.
  • the ratio of solvent to cellulose derivative can be minimized.
  • the ratio can be a minimum of 4.4.
  • lower Conditions usually cause the viscosity of the dope to be too high in the known methods have a negative effect on the fibret fineness. triggers for example, cellulose diacetate in acetone in a mass ratio of 1: 3, you get a gel-like consistency.
  • the viscosity can, however can be reduced by adding water as a non-solvent. In this regard, it is desirable to add water to just below to realize the precipitation point.
  • the prior art methods are for the production of fibrets with an acetone: water mass ratio of, for example, 2.8 and one Non-solvent content up to 2% by mass below the precipitation point in Dope unable.
  • the viscosity is still despite the addition of water too high.
  • the main advantage of the process is that higher viscosities of the Dopes can be processed with satisfactory results.
  • the temperature of the dope is largely uncritical for the process. It good results have been obtained at room temperature.
  • To reduce the Viscosity of the solution can be chosen up to a higher temperature for precipitation at overpressure and temperatures above 100 ° C. is preferred however, the ambient temperature as the most economical option.
  • the two or three components of the dope will be used appropriately mixed until a homogeneous solution is obtained. This solution is then fed to the dispersing device via a filter.
  • the volume flow of the precipitant in the precipitation bath is preferably so set that the fibret content in the precipitation bath is between 0.1 and 2.5% by mass. Differences in fibret quality could not be found even with a high proportion of fibret be determined. At concentrations between 2.5 and 3.5% by mass Another precipitation without clogging of the extrusion nozzles is realized however, accept compromises in fibret fineness and fibrethomogeneity. A range of 1-2.5% by mass is preferred for economic reasons.
  • the method according to the invention is thus significantly better than the methods according to the state of the art, according to which the precipitation occurs only at concentrations between 0.1 and 1% by mass are possible.
  • the longer solidification times of the fibrets also contribute to finer fibrillation and associated with a higher surface area because during the entire solidification time attack shear forces affecting the fibrillation intensify.
  • cellulose diacetate - water - acetone Acetone levels of up to 25% by mass are possible in the precipitation bath.
  • the device for producing the fibrets provides that the feed line for the precipitant opens centrally into the dispersing device, and that the Feed line for the dope at least one nozzle within the Has dispersing device.
  • Precipitation bath and dope are used to achieve the precipitation in the Dispersing device combined.
  • the precipitation bath flows, as from Homogenisierund Dispersing tasks is known through the dispersing machine.
  • the feed line for the precipitant preferably encloses the feed line for the dope.
  • the nozzle is preferably radially outward on the innermost ring gear aligned. In a preferred embodiment, this is in the direction of flow of the precipitation bath first Spider part of the rotor, followed by a spider of a stator, etc.
  • the distance between the ring gear and the nozzle is small to choose the actual one Precipitation in the zone of the shear field to be carried out by the before Nozzle opening as teeth are generated. The distance can be between 0.01 and 5 mm, preferably 0.01-0.1 mm. It is also possible with the first ring gear in the direction of flow of the precipitation bath Equip nozzles for adding the dope.
  • the nozzle diameter can be selected in large ranges because of these parameters has little influence on the quality of the fibrets in the intended area.
  • a nozzle diameter between 5 and 10 mm is preferred. lower However, nozzle diameters are possible. Because during the use of the Disperser no clogging of the nozzles occur, is also the Use of larger nozzles, although possible from the point of view of fibret quality, is not required.
  • Distribution of the dope flow over several nozzles makes sense. Are preferred these nozzles are arranged symmetrically within the innermost ring gear. If, for example, three nozzles are provided, they are star-shaped arranged.
  • the supply line to the nozzles is in this case preferably in the center of the dispersing device.
  • the precipitant is also introduced centrally into the dispersing device. This is ensured by the fact that the feed line of the precipitant preferably encloses the supply line of the dope.
  • the fibers act despite the soft inner core in the process according to the prior art in to such an extent that it prevents turbulence from breaking up is more possible.
  • a disperser it is possible by means of the high shear effect applied by the rotors To split fibers with a soft inner core and therefore the fineness of the fibrets to increase.
  • the dispersing device according to the invention also has a positive effect regarding the agglomerate size of the fibrets.
  • agglomerate size of the fibrets Depending on the choice of rotor-stator geometries and the rotor speed can also Agglomerate sizes up to 1 mm can be achieved. However, are preferred such arrangements and speeds, the agglomerate sizes below 200 microns result. These dimensions are achieved in that End area of the shear field in contrast to the arrangements according to the state the technology still have sufficient shear forces available, the size of the Can minimize fibra agglomerates.
  • FIG. 1 shows the plant for the production of fibrets.
  • the Raw material for example cellulose diacetate
  • a dope preparation tank 2 supplied to the solvent via line 31 is fed from the processing plant 26.
  • a disperser 40 where the precipitation is carried out.
  • the precipitant is in a precipitation bath 8 set in the non-solvent 26 via line 27 from the processing plant, preferably water is supplied.
  • a Precipitation bath feed line 9 the precipitant used in the Disperser 40 initiated where the precipitant with the dope is merged. This is explained in connection with FIG. 2 become.
  • the precipitation bath suspension with the fibrets produced is transferred via the Precipitation bath drain 13 fed to the distillation plant 12.
  • Over a Steam feed line 15 is fed to the distillation plant 12, and via the solvent return line 17 becomes the separated solvent first fed to the treatment plant 26 via a heat exchanger 16, where the treatment of the solvent takes place in such a way that it afterwards can be used again in the dope preparation tank 2 or the precipitation bath preparation tank 8 can.
  • the discharge line 19 is fed to a high-pressure homogenizer 20. From there the fibrets pass into a stacking tank 22 and further into a drum filter 24, where the fibrets are concentrated to the desired final concentration, the precipitation bath also via the return line 25 Processing plant 26 is supplied. The fibrets prepared in this way are fed to further processing via the fibreta lead 23. Of the Processing plant 26 becomes the treated solvent, the one can contain a certain proportion of non-solvent and the non-solvent, which in turn can contain a portion of solvent the lines 27 and 31 introduced into the tanks 2 and 8.
  • the dispersing device 40 is shown in vertical section. About the curved feed line 9, the precipitant is in the interior of the Dispersing device 40 supplied.
  • the double line 3 is located within the feed line 9 and is enclosed by this, so that both the Dope and the precipitant centrally into the dispersing device 40 can be initiated.
  • the branches out within the housing 41 Double line 3 and passes into the nozzles 46 and 47, which together with the Nozzles 48 and 49, which is shown in Figure 3, arranged in a star shape are.
  • the nozzles extend radially outwards and end in a short distance in front of the innermost ring gear 50, which is part of the rotor 44 is.
  • This rotor 44 is driven by a drive shaft 65, which is extends down from the housing 41 and by a motor (not shown) is driven.
  • the seal to the housing 41 takes place via a mechanical seal 64.
  • the rotor 44 which has a base plate 10, comprises, in addition to the first ring gear 50, at a distance from it another one Sprocket (third sprocket) 52. Between the two sprockets 50 and 52 is the second ring gear 51, which belongs to the stator 43.
  • the Stator 43 which has an annular base plate 11, is above the Nozzles 46-49 arranged so that the second ring gear 51 is down extends, and is attached to the housing 41.
  • Below the rotor is a Another stator 45 is arranged, the outer or fourth ring gear 53rd having.
  • the precipitation bath feed line 9 Since the precipitation bath feed line 9 is sealed against the stator 43, this becomes Precipitant fed centrally and flows around the nozzles 46 to 49.
  • the dope which is fed through the double line 3, exits in the radial direction Nozzles 46 to 49 out and into the shear field. that is through the sprockets 50 - 53 extends into the outer region 14.
  • Dope and precipitant will be first gripped by the ring gear 50 and accelerated. Due to the radial flow direction of dope and precipitant, which the Cross flow is superimposed. leaves the dope or the nascent Fibrets located through the gaps 54 between the teeth 55 of the first Sprocket 50 in the radial direction, the zone 60, where dope and Precipitating agents are delayed.
  • the one for fibrin production required degree of turbulence is reached just behind the nozzles, and falls then exponentially, so that only a relatively short distance for the Fibrin production is available.
  • the shear field according to the invention extends at one Dispersing device according to Figures 2 and 3 over about 14 mm (distance Sprocket 50 to sprocket 53), the after the exit from the nozzle the minimum degree of turbulence required for fibrin production is exceeded and remains constant. Curve II only falls when the outside area is reached (see Figure 2) 14 steeply. While according to US 4,047,863 Circumferential speeds of approx. 30 m / sec Rotation speed of the rotor of the dispersing device in this Example at 41 m / sec.
  • 480 g of a cellulose diacetate (CA) from Eastman Chemical Company (type CA 398-3) are dissolved in 3840 g of acetone and 480 g of water.
  • the resulting dope thus contains 10 Ma% CA, 10 Ma% water and 80 Ma% acetone.
  • the ratio of acetone to water is 8.
  • the dope is passed into the precipitation bath at ambient temperature with a mass flow of 3 kg / min through a four-jet nozzle, each with a diameter of 5 mm and the ends of which are 0.10 mm from the inner rotor directed. Water is also used as the precipitation medium at ambient temperature and enters the precipitation chamber with a mass flow of 34.5 kg / min.
  • the mass flows of precipitation bath and dope are in a ratio of 11.5 to 1.
  • the dispersing machine is equipped with four sprockets of the "fine" specification (see Table 1).
  • the precipitation takes place at a speed of 12,000 min -1 .
  • CA fibrets are present with a concentration of 0.8% by mass.
  • Acetone is 6.5% by weight.
  • the values mentioned and the values for the following tests are compared in Table 2.
  • the acetone is removed by open distillation at ambient pressure. After the acetone has been removed, the fibrets are homogenized in one stage using a high-pressure homogenizer from APV GAULIN, type LAB 60, at a pressure of 150 bar.
  • the fibrets are concentrated with a suction filter for storage. A filter cake with a solids concentration of 8.6% by mass is formed.
  • this variant is in the range of the Technology, only the precipitation was carried out with the dispersing machine according to the Invention was carried out and the filtration was carried out after the precipitation waived.
  • the experiment was carried out analogously to experiment 1, except that the precipitation bath mass flow was reduced to 22 kg / min. There was a ratio of the mass flows of precipitation bath to dope of 7.3 and a concentration of the fibrets after precipitation of 1.2 mass% (at 9.6 mass% acetone). High-pressure homogenization was dispensed with.
  • Dope composition in g CA 480 480 480 480 480 480 480 480 480 acetone 3840 3840 3840 2400 1680 2400 2400 1680 water 480 480 480 480 550 510 550 550 550 840 Dope composition in% CA 10 10 10 10 14 18 14 14 14 16 acetone 80 80 80 80 70 63 70 70 70 56 water 10 10 10 16 19 16 16 16 28 relationship Acetone: CA.
  • the experiment was carried out analogously to experiment 1, except that the precipitation bath mass flow reduced to 15.75 kg / min. There was a ratio of the mass flows Precipitation bath to dope of 5.25 and a concentration of the fibrets after the precipitation of 1.6 Ma% (at 12.8 Ma% acetone). On high pressure homogenization was waived.
  • the experiment was carried out analogously to experiment 1, except that the precipitation bath mass flow reduced to 12 kg / min. There was a ratio of the mass flows Precipitation bath to dope of 4.0 and a concentration of the fibrets after the precipitation of 2.0 mass% (at 16.0 mass% acetone). On high pressure homogenization was waived.
  • the experiment was carried out in the same way as experiment 1, except that it was a mass ratio Acetone adjusted to CA of 5. With a mass flow ratio precipitation bath too Dope of 7.2 after precipitation is 1.7 Ma% fibrets with 8.5 Ma% acetone in front.
  • the experiment was carried out in the same way as experiment 1, except that it was a mass ratio Acetone adjusted to CA from 3.5. With a mass flow ratio precipitation bath too Dope of 9.9 after precipitation 1.65 Ma% Fibrets at 5.80 Ma% Acetone before.
  • Experiment 10 was carried out analogously to experiment 6, except that the dope was additional Water was added up to a content of 28% by mass. Were in the precipitation bath 5% by weight acetone present. The fibrets showed one after the precipitation Concentration of 1.5 Ma% at an acetone concentration of 9.8 Ma%.
  • Each of the samples had specific surfaces above 20 m 2 / g and individual fiber dimensions, preferably below 1 ⁇ m. However, further parameters such as homogeneity, accessibility of the fiber networks for the flow etc. are decisive for the filtration.
  • the quality of the fibrets produced was therefore assessed using a filter layer.
  • the following composition was selected for the filter layer: 25% CA fibrets 35% microcrystalline cellulose with a modal particle size distribution at 28 ⁇ m 30% Long fiber pulp, unground 10% Long fiber pulp, ground to 80 ° SR.
  • the layers had a basis weight of 1350 g / m 2 .
  • the layers were tested with a test suspension of 0.5% by weight of raw raw cane sugar in water.
  • the test area was 100 cm 2 .
  • the throughput was determined after 30 min at a differential pressure of 1 bar. After a filtration period of 15 minutes, the turbidity measurement was sampled to determine the separation effect.
  • the initial turbidity for all layers in the test series carried out in parallel was approximately 2.40 TE / F.
  • Each of the filter layers produced with the described fibrets was tested in three runs. Table 3 shows the mean values.
  • the fibrets of sample 9 are positive.
  • the addition of acetone the precipitation medium has a better fibrillation effect here.
  • On the other hand has the geometry of the sprockets used in the examined area no significant influence on the quality of the fibrets.
  • Figure 5 clearly shows the advantages of the invention, which consist in that the Cellulose acetate content can be chosen much larger (see expanded area according to the invention) and that the water content can be significantly higher, which, as described above, has decisive advantages in the Litigation (elimination of the filtration level) and the process costs (Preparation with less effort).

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Dispersion Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Artificial Filaments (AREA)
  • Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

Claims (29)

  1. Procédé de préparation de fibrets, selon lequel un bain de filage est amené de manière centrale dans un dispositif de dispersion fonctionnant selon le principe du rotor/stator et introduit dans un milieu de précipitation, et la suspension formée à partir du bain de filage et du milieu de précipitation est alternativement accélérée et ralentie au moins une fois dans le champ de cisaillement du dispositif de dispersion, ce qui entraíne la précipitation du bain de filage et la formation des fibrets, puis on sépare les fibrets, le solvant et le milieu de précipitation, caractérisé en ce que l'on utilise comme bain de filage un dérivé de cellulose, comme un ester de cellulose ou un éther de cellulose, et un solvant approprié à cet effet, et en ce que le milieu de précipitation est introduit de manière centrale dans le dispositif de dispersion.
  2. Procédé selon la revendication 1, caractérisé en ce que la suspension est alternativement accélérée et ralentie au moins deux fois.
  3. Procédé selon la revendication 2, caractérisé en ce que la suspension est soumise alternativement à un courant radial et à un courant transversal.
  4. Procédé selon l'une des revendications 1 à 3, caractérisé en ce que le bain de filage est introduit dans le milieu de précipitation par des buses fixes (46-49) devant l'ouverture de sortie desquelles sont agités des systèmes de production d'un courant.
  5. Procédé selon l'une des revendications 1 à 4, caractérisé en ce que l'on utilise pour la charge de bain de filage du diacétate de cellulose, du triacétate de cellulose, de l'acétate et butyrate de cellulose, de l'acétate et propionate de cellulose, de la benzylcellulose ou de l'éthylcellulose ou des mélanges de ces matériaux.
  6. Procédé selon la revendication 5, caractérisé en ce que l'on utilise un diacétate de cellulose ayant une valeur d'acétyle comprise entre 54 et 56 %.
  7. Procédé selon l'une des revendications 1 à 6, caractérisé en ce que la fraction de dérivé de cellulose dans le bain de filage est comprise entre 3 et 20 %.
  8. Procédé selon l'une des revendications 1 à 7, caractérisé en ce que l'on règle le rapport du solvant au dérivé de cellulose dans le bain de filage à 2,8 - 4,4.
  9. Procédé selon l'une des revendications 1 à 8, caractérisé en ce que l'on utilise comme solvant de l'acétone, de l'acide acétique, de l'acétate de méthyle, de la méthyléthylcétone, du 1,4-dioxane, de l'acétaldéhyde, de l'acétate d'éthyle, du tétrahydrofurane ou de la méthylisopropylcétone ou des mélanges de ces solvants.
  10. Procédé selon l'une des revendications 1 à 9, caractérisé en ce que l'on ajoute en outre un non-solvant au bain de filage.
  11. Procédé selon la revendication 10, caractérisé en ce que l'on ajoute comme non-solvant de l'eau, de l'éthanol ou du méthanol.
  12. Procédé selon l'une des revendications 10 ou 11, caractérisé en ce que la fraction de non-solvant est inférieure d'au moins 2 % à la fraction de non-solvant à laquelle le mélange de dérivé de cellulose et de solvant commence à précipiter (fraction limite de précipitation).
  13. Procédé selon la revendication 12, caractérisé en ce que la fraction de non-solvant est inférieure de 2 à 20 % à la fraction limite de précipitation.
  14. Procédé selon l'une des revendications 10 à 13, caractérisé en ce que le non-solvant représente jusqu'à 40 % du bain de filage.
  15. Procédé selon l'une des revendications 1 à 14, caractérisé en ce que l'on produit dans le bain de précipitation des vitesses d'écoulement de base allant jusqu'à 100 m/s.
  16. Procédé selon l'une des revendications 1 à 15, caractérisé en ce que l'on établit le courant volumique du milieu de précipitation de manière que la fraction de fibrets dans le bain de précipitation soit comprise entre 1 et 2,5 % en masse.
  17. Procédé selon l'une des revendications 1 à 16, caractérisé en ce que l'on établit les courants volumiques du bain de précipitation et du bain de filage à un rapport compris entre 10:1 et 2,5:1.
  18. Procédé selon l'une des revendications 1 à 17, caractérisé en ce que, après la précipitation, le bain de précipitation contient jusqu'à 25 % en masse de solvant.
  19. Procédé selon l'une des revendications 1 à 18, caractérisé en ce que, après la précipitation, la fraction de solvant dans le bain de précipitation est comprise entre 15 et 25 % en masse.
  20. Procédé selon l'une des revendications 1 à 19, caractérisé en ce que, après l'élimination du solvant, les fibrets sont homogénéisés sans filtration préalable.
  21. Dispositif pour la préparation de fibrets, comportant un dispositif de préparation d'un bain de filage à partir de dérivés de cellulose et de solvants comprenant un dispositif de dispersion (40) fonctionnant selon le principe du rotor et du stator, qui comprend au moins deux couronnes dentées (50) à (53), dont au moins une couronne dentée (50) est un constituant du rotor (44) du dispositif de dispersion (40), et comportant une conduite d'amenée centrale pour le bain de filage et une conduite d'amenée pour un milieu de précipitation, et un dispositif de séparation des fibrets du solvant et du milieu de précipitation, caractérisé en ce que la conduite d'amenée (9) du milieu de précipitation débouche de manière centrale dans le dispositif de dispersion (40), et en ce que la conduite d'amenée (3) du bain de filage comporte au moins une buse (46 à 49) à l'intérieur du dispositif de dispersion (40).
  22. Dispositif selon la revendication 21, caractérisé en ce que les buses (46-49) sont dirigées de façon radiale vers l'extérieur sur la première couronne dentée (50).
  23. Dispositif selon la revendication 21 ou 22, caractérisé en ce que la première couronne dentée (50) est un constituant du rotor (44) du dispositif de dispersion (40).
  24. Dispositif selon l'une des revendications 21 à 23, caractérisé en ce que la distance entre la buse et la couronne dentée est comprise entre 0,01 et 5 mm.
  25. Dispositif selon la revendication 24, caractérisé en ce que la distance entre la buse et la couronne dentée est comprise entre 0,01 et 1 mm.
  26. Dispositif selon l'une des revendications 21 à 25, caractérisé en ce que le diamètre des buses est de 5 à 10 mm.
  27. Dispositif selon l'une des revendications 21 à 26, caractérisé en ce qu'au moins deux buses (46, 47, 48, 49) sont disposées symétriquement à l'intérieur de la première couronne dentée (50).
  28. Dispositif selon l'une des revendications 21 à 27, caractérisé en ce que la conduite d'amenée de milieu de précipitation (9) pour le milieu de précipitation entoure la conduite de bain de filage (3).
  29. Dispositif selon l'une des revendications 21 à 28, caractérisé en ce qu'au moins une buse (46-49) est disposée à l'extérieur des couronnes dentées (50-53) du dispositif de dispersion (40) et est orientée de manière radiale vers l'intérieur sur la couronne dentée la plus extérieure.
EP97106492A 1996-04-23 1997-04-18 Procédé et dispositif pour la préparation d'une structure fibrillaire à base de dérivés de cellulose Expired - Lifetime EP0807698B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19616010A DE19616010C2 (de) 1996-04-23 1996-04-23 Verfahren und Vorrichtung zur Herstellung von Fibrets (Fibriden) aus Zellulosederivaten
DE19616010 1996-04-23

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EP0807698A2 EP0807698A2 (fr) 1997-11-19
EP0807698A3 EP0807698A3 (fr) 1998-04-08
EP0807698B1 true EP0807698B1 (fr) 2002-11-06

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WO2009008146A2 (fr) * 2007-07-11 2009-01-15 Panasonic Corporation Procédé servant à fabriquer du polymère en poudre fine et appareil de fabrication de polymère en poudre fine
CZ2009835A3 (cs) 2009-12-11 2011-06-22 Contipro C A.S. Zpusob prípravy derivátu kyseliny hyaluronové oxidovaného v poloze 6 glukosaminové cásti polysacharidu selektivne na aldehyd a zpusob jeho modifikace
CZ302504B6 (cs) 2009-12-11 2011-06-22 Contipro C A.S. Derivát kyseliny hyaluronové oxidovaný v poloze 6 glukosaminové cásti polysacharidu selektivne na aldehyd, zpusob jeho prípravy a zpusob jeho modifikace
CZ2012136A3 (cs) 2012-02-28 2013-06-05 Contipro Biotech S.R.O. Deriváty na bázi kyseliny hyaluronové schopné tvorit hydrogely, zpusob jejich prípravy, hydrogely na bázi techto derivátu, zpusob jejich prípravy a pouzití
CZ304651B6 (cs) 2012-05-11 2014-08-20 Contipro Biotech S.R.O. Způsob přípravy mikrovláken, způsob výroby krytů ran, kryty ran a zařízení pro přípravu polysacharidových vláken
CZ304512B6 (cs) 2012-08-08 2014-06-11 Contipro Biotech S.R.O. Derivát kyseliny hyaluronové, způsob jeho přípravy, způsob jeho modifikace a použití
CZ2012842A3 (cs) 2012-11-27 2014-08-20 Contipro Biotech S.R.O. Nanomicelární kompozice na bázi C6-C18-acylovaného hyaluronanu, způsob přípravy C6-C18-acylovaného hyaluronanu, způsob přípravy nanomicelární kompozice a stabilizované nanomicelární kompozice a použití
CZ305153B6 (cs) 2014-03-11 2015-05-20 Contipro Biotech S.R.O. Konjugáty oligomeru kyseliny hyaluronové nebo její soli, způsob jejich přípravy a použití
CZ2014451A3 (cs) 2014-06-30 2016-01-13 Contipro Pharma A.S. Protinádorová kompozice na bázi kyseliny hyaluronové a anorganických nanočástic, způsob její přípravy a použití
CZ309295B6 (cs) 2015-03-09 2022-08-10 Contipro A.S. Samonosný, biodegradabilní film na bázi hydrofobizované kyseliny hyaluronové, způsob jeho přípravy a použití
CZ306479B6 (cs) 2015-06-15 2017-02-08 Contipro A.S. Způsob síťování polysacharidů s využitím fotolabilních chránicích skupin
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CZ308106B6 (cs) 2016-06-27 2020-01-08 Contipro A.S. Nenasycené deriváty polysacharidů, způsob jejich přípravy a jejich použití
WO2024206272A2 (fr) * 2023-03-29 2024-10-03 Eastman Chemical Company Procédés de fabrication de microbilles d'ester de cellulose avec récupération et recyclage de solvant
WO2024206270A2 (fr) * 2023-03-29 2024-10-03 Eastman Chemical Company Procédés de fabrication de microbilles d'ester de cellulose avec un solvant contenant de l'eau
CN119710953A (zh) * 2024-11-28 2025-03-28 浙江理工大学 一种用于生产并列型复合微纳米纤维的离心纺喷丝器

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Publication number Publication date
DE59708645D1 (de) 2002-12-12
AU757068B2 (en) 2003-01-30
DE19616010C2 (de) 1998-07-09
EP0807698A3 (fr) 1998-04-08
AU1907897A (en) 1997-10-30
US5868973A (en) 1999-02-09
EP0807698A2 (fr) 1997-11-19
DE19616010A1 (de) 1997-11-06

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