PROCESS FOR CONTINUOUSLY PREPARING A BROKEN-UP CELLULOSE-CONTAINING STARTING MATERIAL

Abstract

A method for continuously providing a treated cellulose-comprising starting material (110), in particular as starting material for manufacturing a cellulosic molded body (102), is provided. The method comprises: i) supplying (10) a cellulose-comprising starting material (101), which in particular is a solid matter, with a predefined composition to a reactor device (105), ii) continuously treating (20) the starting material (101) in the reactor device (105), to obtain the treated cellulose-comprising starting material (110), and iii) discharging (30) the treated cellulose-comprising starting material (110) from the reactor device (105).

Claims

1-15. (canceled)

16. A method for continuously providing a treated cellulose-comprising starting material for manufacturing a cellulosic molded body, wherein the method comprises: supplying a cellulose-comprising starting material with a predefined composition to a reactor device; continuously treating the cellulose-comprising starting material in the reactor device, to obtain the treated cellulose-comprising starting material; and discharging the treated cellulose-comprising starting material from the reactor device.

17. The method according to claim 16, wherein the cellulose-comprising starting material entirely or partially comprises remains from a clothing manufacture or used clothes.

18. The method according to claim 16, further comprising: adjusting the predefined composition, wherein adjusting comprises: selectively enriching at least one composition component, or selectively depleting at least one composition component.

19. The method according to previous claim 16, wherein continuously treating further comprises: performing a continuous boiling process using an alkaline boiling solution.

20. The method according to claim 16, wherein the predefined composition comprises cellulosic fibers, and wherein the predefined composition of the cellulosic fibers comprises a fluctuation range of 2.5% or less.

21. The method according to claim 16, wherein the predefined composition comprises synthetic fibers, and wherein the predefined composition of the synthetic fibers comprises a fluctuation range of 2.5% or less.

22. The method according to claim 16, wherein the predefined composition comprises further synthetic fibers, and wherein the predefined composition of the further synthetic fibers comprises a fluctuation range of 0.5% or less; wherein the further synthetic fibers comprise at least one of the group consisting of polyamide, polyacrylic, and elastane.

23. The method according to claim 16, wherein the predefined composition comprises 60% or more, cellulosic fibers, or wherein the predefined composition comprises 30% or less, synthetic fibers.

24. The method according to claim 16, wherein the predefined composition comprises at least one of the following features: wherein the predefined composition comprises 4% or less polyamide; wherein the predefined composition comprises 1% or less polyacrylic; wherein the predefined composition comprises 5% or less elastane.

25. The method according to claim 16, wherein the reactor device comprises a continuous boiler, in particular a Pandia boiler.

26. The method according to claim 16, further comprising: performing a bleaching process after continuously discharging.

27. A method for manufacturing a regenerated, cellulosic molded body, the method comprising: providing a treated cellulose-comprising starting material according to claim 16; and forming the cellulosic molded body from the treated cellulose-comprising starting material.

28. The method according to claim 27, wherein forming the cellulosic molded body from the treated starting material comprises one of the group consisting of a lyocell method, a viscose method or a paper manufacturing method.

29. The method according to claim 27, wherein the regenerated, cellulosic molded body is selected from the group consisting of a filament, a fiber, a foil, a sponge, a microsphere, a bead, or a paper tissue.

30. Use of a continuous boiling aggregate for continuously treating a cellulose-comprising starting material being used textiles, with a predefined composition.

Description

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0081] FIG. 1 shows a flow diagram of a method for continuously providing a treated starting material according to an exemplary embodiment of the invention.

[0082] FIG. 2 shows a flow diagram of a method for manufacturing a regenerated cellulosic molded body from the treated starting material, according to an exemplary embodiment of the invention.

[0083] FIG. 3 shows a device for providing the treated starting material and for manufacturing a regenerated cellulosic molded body by a lyocell method from the treated starting material according to an exemplary embodiment of the invention.

[0084] FIG. 4 shows a cellulose fiber which is manufactured by a lyocell method.

[0085] FIG. 5 shows a cellulose fiber which is manufactured by a viscose method.

[0086] FIG. 6 shows a natural cellulose fiber from a cotton plant.

[0087] Same or similar components in different figures are provided with the same reference numbers.

[0088] Before exemplary embodiments are described with reference to the figures, some basic considerations shall be summarized, based on which exemplary embodiments of the invention are derived.

[0089] According to an exemplary embodiment, in the manufacture of a suitable used textile mixture (predefined composition), it is proceeded as follows, for example: from a raw (still untreated) used textile mixture with a high amount of cotton or cellulose fibers (e.g. viscose, lyocell) and synthetic polymer fiber amounts (e.g.: PP, PET, PA, PUR-TPE), by shredding, flotation, selectively solving, boiling, or other standard processes in large industrial scale, a treatment is performed, wherein a 100% removal of undesired constituents is very elaborate. Therefore, the following material mixture according to embodiments of the invention was determined: 1) the amount of non-textile additional materials from the list (buttons, rivets, clips, eyelets) is below 0.1%, the amount of polyamide is below 0.1%, the amount of PTFE is below 0.1%, the amount of polyester (PET) is below 30%, the amount of polyolefins (PE and preferably PP) is below 1%, the amount of TPE on basis of PEG-PUR is below 10%, the amount of polyacrylic nitrile (PAN) is below 1%, residual constituents are mainly cellulose-based textiles; or 2) more than 60% cellulose, below 10% PET, preferred below 5%, even more preferred below 2%, below 15% PUR-TPE with soft segments made of polyolefin ethers or aliphatic esters (elastane), below 5% PA, addition of more than 0.1% AO-stabilizer for preventing the oxidative integration of desired polymers to undesired oligomers (which would induce negative product properties, such as instable mechanical properties, brittleness, tendency to color change, etc.).

[0090] According to an exemplary embodiment, the following details in the manufacture of the substance mixture of the addition in the NMMO-solution are considered: used textiles which are available for recycling are selected due to the following characteristics and are treated and supplied, e.g. to the lyocell process, as constituents of the substance mixtures in a suitable form: a) reduction to the textile parts (therefore removal of buttons, rivets, zip fasteners, hook and loop fasteners, applications etc.); b) specific selection or amount determination for a subsequent proportional combination of the substance streams of the following fiber constituents: i) cellulosic fibers: these are desired, they differ from each other by molecular weights and therefore solubility in NMMO (viscosity), adjustment and adaption by an alkaline treatment. In the ideal case, these materials constitute 100% of the recyclate textiles. These materials encompass cotton, viscose, lyocell, linen, etc.; ii) polyamides: insoluble in NMMO, degradation by acidic hydrolysis. In typical raw used textile mixtures, cotton is contained by up to 80%, polyamides up to 25%, in certain tissues, which may be simply selected by sorting (sweater, “cotton character”). There is no real possibility for a removal by selectively solving. To these materials belong cotton, silk, synthetic polyamide PA6 and PA6.6 (nylon, perlon); iii) polyester: insoluble in NMMO, degradation by alkaline hydrolysis with recovery of the acidic portion, possibility for separation by selectively solving. Recycling amounts up to 30% in tissues. To these materials belong e.g. PET and elasto-polyester; iv) polyolefins: insoluble in NMMO, no possibility for degradation by hydrolysis, but separation by selectively solving. Low content in delivered recycling tissues (below 1%). To these materials belong e.g. PP as fiber and PE as hot melt adhesive in fleeces; v) others: PEG-PUR up to 5% soluble in NMMO, up to 10% in tissues, PAN insoluble in NMMO, both degradable by intensive (German: scharfe) acidic hydrolysis. PTFE: insoluble and not degradable. In most cases handable by sorting (e.g. anoraks). To these materials belong e.g. PEG-PUR (elastane, Lycra, spandex), polyacrylic nitrile (PAN), PTFE (Gore-Tex).

[0091] According to a further exemplary embodiment, residual polymers from starting materials are used as adhesion promoter among cellulose fibers or as thermoplastic property promoter within a lyocell molded body. They remain substantially inert until finishing a certain stage in the production process. In particular, a subsequent stiffening of a tissue by heat (analog to hot melt adhesive) may thus be achieved (e.g. non-iron shirts, pleating, etc.). For manufacturing tissues which have the property of a high dimensional stability (e.g. non-iron), an elaborate method is typically used. This may be the combination of very elaborate chemical methods, for example. It makes a shirt looking new for a long time. Also the so-called “humid cross-linking” is possible, wherein an elastic bridge is formed between the molecules of cotton cellulose. This bridge pulls the tissue in form again after washing.

[0092] By the specific control of the amount of residual polymers (e.g. polyurethane from elastane of mixed textiles) according to an embodiment, a certain thermoplasticity may nevertheless be achieved in a lyocell fiber, which guides the corresponding amount of residual polymers from a starting material via the depleting process, according to an embodiment, via a lyocell method back into a lyocell molded body again.

[0093] According to an exemplary embodiment, by the pre-treatment of the used textile mixture, a subsequent depletion of foreign matters is minimized and/or the adjustment of the desired residual concentrations is facilitated. In textile recyclates already present inorganic residual constituents are e.g. metal compounds (predominantly metal oxides, in particular TiO.sub.2, Al.sub.2O.sub.3, MgO, SiO.sub.2, CeO.sub.2, Mg(OH).sub.2, Al(OH).sub.3, ZnO). The functionalization of these oxides is suitable e.g. for a manifestation of different properties at the manufactured molded body (e.g. flame protection, antireflection, biocide, etc.).

[0094] According to an exemplary embodiment, it has further turned out, that the following substances are suitable AOs: HALS stabilizers, polyvalent phenols, in particular alkalized bi- and tri-phenols, tocopherol, oligomer lignins, and gallates. They have the advantage, that they are already approved in use as stabilizers for masking heavy metals (complexing) in NMMO-dope and their process handling in large industrial scale is unproblematic. It has now surprisingly turned out, that these AOs in NMMO, which is acting as oxidant due to its structure (N-oxide), nevertheless prevent the oxidative degradation of polymers, in particular that of elastane, which is necessary for compatibilization in the mixture.

[0095] According to an exemplary embodiment, the circumstance is considered, that certain cellulose-foreign matters may be incorporated in a certain amount in a lyocell molded body. Surprisingly, it has turned out, that certain residual materials which are not based on cellulose may be considered as desired auxiliary substances, which facilitate to incorporate other residual materials which are not based on cellulose into a lyocell molded body to a larger extent. Such a substance group, which is both non-cellulosic secondary constituent and incorporation promoter, are TPE-type plastics (e.g. elastanes). This mentioned incorporation effect operates to such an extent, that low amounts (below 2%) of polyamides (PA) and polyesters (PET below 2%) may be co-processed. In the recyclate-treatment process, this is a significant advantage, since the almost complete removal of the mentioned polymers is disproportionally elaborate and the possible acceptance of low residual amounts massively facilitates the recyclate treatment, since precisely these polymers are very frequently and commonly contained in textile recyclates. This behavior is explained by the compatibility effect of elastane between PA-PET and cellulose. The PUR-amount of elastane is responsible for this, since PUR is a polyester and a polyamide at the same time (R1.NH.CO.O.R2). The polyalkyleneoxide amount in TPEs; such as elastane, is moreover responsible, due to its typical ether structure, for the homogenization/mixture with the glycan ether compounds of the cellulose. According to embodiments of the invention, this multiple effect is also utilized in this multiple manner: i) by the process temperatures of the lyocell process, the elastane is connected in a suitable manner with the cellulose by hydrogen bonds; ii) the polyamide similarities of these TPEs enable to incorporate typical fiber polyamides (PA6 or PA6.6 or PA6.10) from used materials; iii) the ether structure leads to a high homogenization of the dope prior to the spinning process and thereby to a very good mixing (in particular also on a chemical level, since the relationship of the ether structure of the TPEs is very similar to the ether structure of the cellulose; and iv) the polyester similarities of these TPEs enable to incorporate typical fiber polyesters from used textiles. In particular, by mixing different used textile compositions, a suitable recyclate quality may be adjusted and thus the subsequent utilization may be specifically controlled.

[0096] FIG. 1 shows a flow diagram of a method for continuously providing (see reference sign 50) a treated starting material 110 according to an exemplary embodiment of the invention. At first, a cellulose-containing starting material 101 is provided 1, which is a mixture of used textiles (used clothes and/or remains from a clothing manufacture). It may be delivered from different sources (pre-/post-consumer) and may be very inhomogenous. The used textiles 101 do not only comprise cellulose, but also partially high contents of synthetic fibers (e.g. polyester). In a first stage of providing (see block 1), at first, mechanically comminuting 1 the used textiles 101 by shredding may be performed. Thereby, mainly large non-cellulosic disturbing matters may be removed from the starting material 101, for example buttons, seams, and prints of the used clothes which are at least partially used for generating the starting material 101. By mechanically comminuting, the starting material 101 may be separated into single fibers, for example.

[0097] In a further stage, the composition of the used textiles is determined (see block 2). Optionally, this stage may also be performed before comminuting. Determining the composition may be continuously performed at a (recycling) stream of used textiles. For this purpose, different automatic measurement techniques (e.g. optical and/or spectroscopic methods) may be used. Alternatively, also a skilled operator may determine the composition. Furthermore, the composition may be at least partially pre-known (e.g. in case of clothing remains from the production). The determined composition (actual value) may subsequently be compared with a target value of the predefined composition.

[0098] Corresponding to the deviation from the target value, selectively enriching (see block 4) and/or selectively depleting (see block 6) may be performed. The starting material 101 is a used textile mixture with cellulose fibers and synthetic fibers. To achieve a predefined composition, charges with known compositions (known amounts of composition components) are mixed, such that the mixture finally comprises the predefined composition. Especially suitable are the above described (cutting waste) remains from the clothing production, which comprise a substantially known composition. Moreover, used textiles with a known composition, e.g. a very high cotton content, may be added, to increase the cellulose content. Furthermore, also composition components with at least partially known composition may be removed from the starting material 101. For example; specifically sportswear may be removed, which comprises an especially high amount of polyester. Moreover, mechanically separating, e.g. a density separation, in particular by a flotation method, may be performed, to selectively deplete e.g. polyester and/or polypropylene from the cellulose. Fiber constituents may be suspended in a liquid (aqueous) medium. Separating the non-cellulosic fibers from the cellulosic fibers is successfully performed due to different physical properties in the liquid medium, in particular different gravitational, centrifugal force-related, floating, and/or electrostatic properties.

[0099] The starting material 101 with the predefined composition is then continuously supplied (see block 10) to the reaction device 150. The starting material is comminuted/shredded and may be directly supplied to the reactor 150 as solid matter or by an additional solvent. The reactor device 105 comprises a continuous boiler (digester) which operates a continuous boiling process for treating (stage 20) the starting material. The boiling process is acidic (e.g. sulfite method) or alkaline (e.g. sulfate/kraft-method or direct application of caustic soda). The starting material and the boiling solution may be supplied to the reactor device 105 initially in a separated manner, and may then be mixed. However, also previously mixing may be performed, such that the starting material 101 is supplied to the reactor device 105 in a manner at least partially solved in the boiling solution. Under application of a high temperature (e.g. 90° C. to 185° C.) and/or a high pressure (e.g. 1 to 21 bar), the treatment (see block 20) of the starting material 101 is performed. The reactor device 105 may comprise a conveyor screw, to continuously transport the starting material 101 through the boiler. During the boiling process, an at least a partial degradation of plastics (e.g. polyester saponification) takes place. In this way, plastic-depleted cellulose; but also highly pure cellulose may be provided. Downstream of the boiler, a cleaning stage may be performed. Subsequently, continuously discharging (see block 30) the treated starting material 110 follows. The treated starting material 110 is present as concentrated cellulose (in comparison with the starting material), which optionally still comprises residues of plastics.

[0100] The treated starting material 101 may undergo further (continuous) treatment stages (see block 40). These encompass e.g. a further cleaning stage and a bleaching process. The correspondingly purified cellulose-comprising starting material 110, as illustrated in block 80, is subsequently supplied to a method for manufacturing a cellulosic molded body 102. An example for such a method is a lyocell method which is described in detail with respect to the FIGS. 2 and 3 (see below). The obtained molded body 102 (e.g. as fiber in a lyocell textile or also a paper fiber) may be again recycled after use (illustrated with reference sign 90) and may be added to the cellulose-containing starting material 101 again.

[0101] FIG. 2 shows a flow diagram 80 of a method for manufacturing a regenerated cellulosic molded body 102 (compare FIG. 3) from the treated starting material 110 according to an exemplary embodiment of the invention.

[0102] The starting material 110 is provided by a continuous treatment process (see block 50, compare FIG. 1). As illustrated with block 50, a such manufactured treated starting material 110 may be used for a subsequent lyocell- or viscose method, wherein the former is described in more detail in the following.

[0103] In the following, it is described, how molded bodies 102 made of cellulose may be manufactured on basis of the cellulose-comprising starting material 110, according to an embodiment of the invention. For this purpose, the starting material 110 is supplied to a device (100, see FIG. 3) for performing a lyocell method. At first, optionally preparing (stage 62) the treated starting material 110 is performed, e.g. cleaning or comminuting. It is also possible (see block 64) to commonly utilize the cellulose-comprising starting material 110 with other cellulose-comprising materials for the subsequent lyocell method. Thus, the starting material 110 may be mixed with a further starting material, which comprises cellulose and at least one synthetic plastic, see block 64. This supplied further starting material comprises an amount of synthetic plastics, which is different from the amount of synthetic plastic in the starting material 110. Generating the regenerated cellulosic molded body may now be executed based on the starting material 110 and the further starting material, such that the regenerated cellulosic molded body 102 contains a predetermined amount of synthetic plastic. Alternatively or additionally, the further starting material may also comprise remains from a clothing manufacture, for example.

[0104] Directly after preparing 62 and/or directly after mixing 64, directly solving 68 the (pure and/or mixed) starting material 110 in a further solvent 116 (for example tertiary amine oxides, such as N-methylmorpholine-N-oxide (NMMO), for example) may be performed, advantageously without chemical pretreatment. In more detail, the mechanically comminuted (and optionally mixed) starting material 110 may be directly transferred into solution, in particular without a chemical cleaning and without an adjustment of the viscosity. In this way, the manufacturing- and/or recycling method may be performed exceptionally simple and rapid and ecological.

[0105] Alternatively, the method may comprise optionally chemically cleaning 66 the starting material 110 after preparing 62 (or after mixing 64) and prior to solving 68. Such an optional cleaning 66 may comprise at least partially removing colorants by bleaching, for example. It is thereby possible to entirely or partially discolor the starting material 110 prior to subsequently solving 68 the starting material 110 in a solvent 116, for example to manufacture white or grey molded bodies 102. Alternatively or additionally, it is also possible, that in the context of optionally chemically cleaning 66, the starting material 110 (prior or after its solving 68) is at least partially freed from cross-linkers which are cross-linking the fibers of the starting material 110. In applications, in which such cross-linkers are present between the fibers of the starting material 110, the starting material 110, for example by an alkaline or an acidic pretreatment, may be entirely or partially freed from these cross-linkers. This additionally improves the solubility of the starting material 110. By cleaning 66, at least a part of synthetic plastic may be optionally removed, if desired. For example, in this way, the amount of synthetic plastic in the molded body 102 to be manufactured may be adjusted and/or influenced.

[0106] After solving 68 the starting material 110 in the solvent (preferably NMMO), the obtained lyocell spinning solution 104 may be pressed through one or more spinning nozzles, whereby threads and/or filaments of a honey-like viscosity are generated (see block 70 which relates to spinning).

[0107] During and/or after the fall of these threads and/or filaments, they are brought in operational connection with an aqueous milieu and are thereby thinned. The concentration of the solvent 116 of the threads and/or filaments is thereby reduced in an aqueous fog and/or an aqueous liquid bath to such an extent, that the lyocell spinning solution is transferred into a solid phase made of cellulose-filaments. In other words, a precipitating, precipitation, or coagulating of the cellulose-filaments occurs, see reference sign 72. Thereby, a preform of the molded body 102 is obtained.

[0108] Furthermore, the method may comprise postprocessing 74 the precipitated lyocell-cellulose for obtaining the molded body 102 from the preform of the molded body 110. Such a posttreatment may encompass drying, impregnating and/or reshaping the obtained filaments to the final molded body 102, for example. For example, the molded body 102 may be processed by the described manufacturing method to fibers, a foil, a tissue, a fleece, a sphere, a porous sponge, or beads and may then be supplied to a further use (compare reference sign 76).

[0109] Advantageously, after the use of the molded body 102, its cellulose and optional synthetical plastics may be recovered again by performing a further method corresponding to the method stages between the reference signs 50 and 74 (see block 90). Alternatively, the cellulose and the optional further synthetical plastic of the molded body 102 may be recovered in another method, for example a viscose method.

[0110] FIG. 3 shows a device 100 for continuously providing a treated cellulose-comprising starting material 110 and for manufacturing a regenerated cellulosic molded body 102 by a lyocell method on basis of the starting material 110, according to an exemplary embodiment of the invention, which is described with reference to the FIGS. 1 and 2.

[0111] FIG. 3 shows a device 100 according to an exemplary embodiment of the invention for manufacturing a cellulose-comprising molded body 102 which may be manufactured in form of a fleece (nonwoven) as a fiber, a foil, a sphere, a textile tissue, a sponge, or in form of beads or flakes. According to FIG. 3, the molded body 102 may be manufactured directly from a spinning solution 104. The latter is converted by a coagulation fluid 106 (in particular made of air humidity) and/or a coagulation bath 191 (for example a water bath which optionally comprises tertiary amine oxides, such as N-methylmorpholine-N-oxide (NMMO)) into cellulose fibers 108 as molded body 102. By the device 100, a lyocell method may be performed. In this way, as molded body 102, for example substantially endless filaments or fibers 108 or mixtures of substantially endless filaments and fibers 108 of a discrete length may be manufactured. A plurality of nozzles which respectively have one or more openings 126 (which may also be denoted as spinning holes) are provided, to eject the lyocell spinning solution 104.

[0112] As can be taken from FIG. 3, a cellulose-based starting material 110 may be supplied to a storage reservoir 114 via a dosing unit 113 to the lyocell method 80. The starting material 110 is a treated starting material 110 which was obtained in a continuous treatment process 50 (see FIG. 1 above). For this purpose, a cellulose-comprising starting material 101, namely used textiles, are continuously supplied (see 10) with a predefined composition to a reactor device 105. In the reactor device 105, the cellulose-comprising starting material 101 is continuously treated (see 20), to obtain the treated cellulose-comprising starting material 110. Subsequently, the treated cellulose-comprising starting material 110 is continuously discharged from the reactor device 105. Furthermore, the treated cellulose-comprising starting material 110 undergoes a continuous bleaching process (see 40).

[0113] According to an embodiment, a water introduction into the cellulose-based starting material 110 may be performed by a solvent 116 which is described in more detail below (in particular NMMO). Also the cellulose-based starting material 110 itself may already contain a certain residual humidity (dry pulp frequently has a residual humidity of 5 weight percent to 8 weight percent, for example). In particular, according to the described embodiment, the starting material 110 may be directly given into a mixture of water and solvent 116 without a premoistening. An optional water container 112 which is shown in FIG. 3 may then be omitted.

[0114] According to an alternative embodiment, the cellulose-comprising starting material 110 may be additionally moistened, to thereby provide humid cellulose. For this purpose, water from an optional water container 112 may be supplied to the storage reservoir 114 via the dosing unit 113. Therefore, the dosing unit 113, controlled by a control unit 140, may supply adjustable relative amounts of water and starting material 110 to the storage reservoir 114.

[0115] A suitable solvent 116, preferably tertiary amine oxides, such as N-methylmorpholine-N-oxide (NMMO), respectively an aqueous mixture of the solvent 116, for example a 76% solution of NMMO in water, is contained in a solvent container. The concentration of the solvent 116 may be adjusted in a concentration unit 118 either by adding pure solvent or water. The solvent 116 may then be mixed with the starting material 110 with definable relative amounts in a mixing unit 119. Also the mixing unit 119 may be controlled by the control unit 140. Thereby, the cellulose-comprising starting material 110 is solved in the concentrated solvent 116 in a solving unit 120 with adjustable relative amounts, whereby the lyocell spinning solution 104 is obtained. The relative concentration ranges (also denoted as spinning window) of the components starting material 110, water, and solvent 116 in the spinning solution 104 for manufacturing cellulosic regenerate molded bodies according to the lyocell method may be adjusted in a suitable manner, as known to a skilled person.

[0116] The lyocell spinning solution 104 is supplied to a fiber generation unit 124 (which may be formed with a number of spinning bars or jets 122).

[0117] When the lyocell spinning solution 104 is guided through the openings 126 of the jets 122, it is separated into a plurality of parallel threads made of lyocell spinning solution 104. The described process control transforms the lyocell spinning solution 104 into increasingly long and thin threads, whose properties may be adjusted by a corresponding adjustment of the process conditions, controlled by the control unit 140. Optionally, a gas flow may accelerate the lyocell spinning solution 104 on its way from the openings 126 to a fiber receiving unit 132.

[0118] After the lyocell spinning solution 104 has moved through the jets 122 and further downwards, the long and thin threads of the lyocell spinning solution 104 interact with the coagulation fluid 106.

[0119] In the interaction with the coagulation fluid 106 (for example water), the solvent concentration of the lyocell spinning solution 104 is reduced, such that the cellulose of the starting material 110 coagulates and/or precipitates at least partially as long and thin cellulose fibers 108 (which may still contain residues of solvent and water).

[0120] During or after the initial formation of the individual cellulose fibers 108 made of the extruded lyocell spinning solution 104, the cellulose fibers 108 are received at the fiber receiving unit 132. The cellulose fibers 108 may immerse into the coagulation bath 191 which is illustrated in FIG. 3 (for example a water bath, optionally comprising a solvent, such as NMMO) and may complete their precipitation in the interaction with the liquid of the coagulation bath 191. Depending on the process adjustment of the coagulation, the cellulose may form cellulose fibers 108 (as shown, wherein the cellulose fibers 108 are made of one substance and/or are integrally merged with each other (“merging”), or may be present as separate cellulose fibers 108), or at the fiber receiving unit 132, a foil and/or a film made of cellulose may form (not illustrated in FIG. 3).

[0121] Thus, the cellulose fibers 108 are extruded out of the spinning nozzles of the jets 122 and are guided through the spinning bath and/or coagulation bath 191 (for example containing water and NMMO in low concentration for precipitation/coagulation), wherein the cellulose fibers 108 are guided around a respective redirecting roller 193 in the coagulation bath 191 and are supplied to a withdrawal galette (German: Abzugsgalette) 195 outside of the coagulation bath 191. The withdrawal galette 195 serves for a further transport and post-stretching of the cellulose fibers 108, to achieve a desired titer. Downstream of the withdrawal galette 195, the fiber bundle made of the cellulose fibers 108 is washed in a washing unit 180, if necessary scrooped (German: aviviert) and finally cut (not shown).

[0122] Although not illustrated in FIG. 3, a solvent 116 of the lyocell-spinning solution 104, which is removed from the cellulose fibers 108 during coagulation and a subsequent washing in the washing unit 180, may be at least partially recovered and/or recycled, and may be transferred into the storage container 114 again in a subsequent cycle.

[0123] During the transport along the fiber receiving unit 132, the molded body 102 (here in form of the cellulose fibers 108) may be washed by the washing unit 180, by the latter supplying a washing liquid for removing solvent residues. Subsequently, the molded body 102 may be dried.

[0124] Moreover, the molded body 102 may be subjected to a posttreatment, see the schematically illustrated posttreatment unit 134. For example, such a posttreatment may comprise a hydroentanglement, a needling, an impregnation, a steam treatment with a steam which is supplied under pressure, and/or a calendaring, etc.

[0125] The fiber receiving unit 132 may supply the molded body 102 to a winding unit 136, at which the molded body 102 may be wound up. The molded body 102 may then be supplied as rolling freight to an entity which manufactures products, such as wipes or textiles, on basis of the molded body 102.

[0126] FIG. 4 shows a cellulose fiber 200 in cross-section which is manufactured by a lyocell-method. The cellulose fiber 200 which is manufactured by a lyocell-method has a smooth round outer surface 202 and is homogenous and free of microscopic holes filled with cellulose material. Thus, it may be distinctly differentiated by a person skilled in the art from cellulose fibers which are manufactured by a viscose method (see reference sign 204 in FIG. 5) and from cellulose fibers made of cotton plants (see reference sign 206 in FIG. 6).

[0127] FIG. 5 shows a cellulose fiber 204 in cross-section which is manufactured by a viscose-method. The cellulose fiber 204 is cloud-shaped and comprises a plurality of arc-shaped structures 208 along its outer circumference.

[0128] FIG. 6 shows a natural cellulose fiber 206 of a cotton plant in cross-section. The cellulose fiber 206 is kidney-shaped and comprises a lumen 210 which is free of material as fully circumferentially enclosed hollow in its interior.

[0129] By means of the significant geometrical and/or structural, differences of the fibers according to FIG. 4 to FIG. 6, it is possible for a person skilled in the art, for example by a microscope, to unambiguously determine, if a cellulose fiber is formed by the lyocell-method, by the viscose-method, or is naturally formed in a cotton plant.

[0130] Supplementary, it is to be noted, that “comprising” does not exclude other elements or steps, and “a” or “an” does not exclude a plurality. Furthermore, it is noted, that features or steps, which are described with reference to one of the above embodiments, may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims shall not be construed as limitation.