阅读说明：本技术 通过偏转而纺织长丝的方法和装置 (Method and device for spinning filaments by deflection ) 是由 S·济凯利 F·埃克 于 2019-06-10 设计创作，主要内容包括：本发明涉及通过偏转而纺织长丝的方法和装置,其中由纤维素流体制备固体纤维素长丝的方法包括以下步骤：将所述流体挤出通过多个挤出开口,由此形成流体长丝；以及在凝固浴中固化所述长丝,其中长丝在凝固浴中集束并以束的形式偏转,从而在凝固浴水平面上方从凝固浴中牵出,其中长丝束在偏转装置上占据如由公式所限定的偏转宽度L。(The invention relates to a method and a device for spinning filaments by deflection, wherein the method for producing solid cellulose filaments from a cellulose fluid comprises the following steps: extruding the fluid through a plurality of extrusion openings, thereby forming fluid filaments; and solidifying the filaments in a coagulation bath, wherein the filaments are bundled in the coagulation bath and deflected in the form of a bundle so as to be drawn out of the coagulation bath above the coagulation bath level, wherein the bundle of filaments occupies a deflection width L as defined by the formula on the deflection device.)

1. a process for preparing solid cellulose filaments from a cellulose fluid, the process comprising the steps of: extruding the fluid through a plurality of extrusion openings, thereby forming fluid filaments, preferably passing the fluid filaments through an air gap; and solidifying the filaments in a coagulation bath, wherein the filaments are bundled and deflected in the form of bundles in the coagulation bath so as to be drawn out of the coagulation bath above the coagulation bath level, characterized in that the bundle of filaments occupies a deflection width L on the deflection device, which deflection width L is controlled according to the following formula:

L>(2x LZ x cos(B/2)x v^2.5)/(10x c_cell ^0.5x Q)，

where L is the deflection width of the bundle in mm, LZ is the number of extrusion openings, B is the deflection angle calculated as 180 minus the wrap angle of the filaments around the deflection device, expressed in degrees, v is the drawing speed of the filaments in meters per second, c_cellQ is a dimensionless load number, where Q is 15 or less, for the cellulose concentration in mass% of the extruded fluid.

2. Apparatus for carrying out the method of claim 1, the apparatus comprising: an extrusion plate having a plurality of extrusion openings, a collection container for receiving a coagulation bath, preferably a gas gap arranged between the extrusion openings and the collection container, a deflection device arranged in the collection container for deflecting the fiber bundles from the collection container, and a bundling device which determines a deflection width L of the filament bundles on the deflection device, wherein the filament bundles on the deflection device occupy the deflection width L which satisfies the requirement of the following formula:

L>(2x LZ x cos(B/2)x v^2.5)/(10x c_cell ^0.5x Q)，

wherein L, LZ, B, v, c_cellAnd Q is as defined in claim 1, Q is 15 or less, and v is at least 35 m/min.

3. Method or device according to claim 1 or 2, characterized in that Q is 12 or less, preferably 8 or less or 5 or less, and/or Q is 2 or more, preferably 3 or more or 4, or 5 or more, wherein Q is 2 to 15 or more preferably 4 to 12 being particularly preferred.

4. Method or device according to any of claims 1 to 3, characterized in that the number LZ of extrusion openings is 2000 or more, preferably 5000 or more or 10000 or more, and/or the LZ is 500000 or less, preferably 100000 or less or 50000 or less.

5. Method or device according to any of claims 1 to 4, characterized in that the deflection angle B is an angle of 10 ° to 90 °, preferably 20 ° to 60 ° or 25 ° to 45 °.

6. Method or apparatus according to any of claims 1 to 5, characterised in that the drawing speed v is 36m/min or higher, preferably 40m/min or higher or 45m/min or 50m/min or higher and/or 200m/min or lower or 150m/min or lower.

7. A method or apparatus according to any of claims 1 to 6, characterised in that the cellulose concentration c of the extruded fluid_cellFrom 4% to 23%, preferably from 6% to 20%, in particular from 8% to 18% or from 10% to 16%, all percentages being by mass%, and/or wherein the extruded fluid contains cellulose, NMMO and water, or cellulose, an organic cationic solvent and water.

8. Method or device according to any of claims 1 to 7, characterized in that a gas flow is injected into the gas gap or for this purpose a blower is provided in the device, wherein the temperature of the gas flow is preferably 5 ℃ to 65 ℃, preferably 10 ℃ to 40 ℃.

9. Method or device according to any of claims 1 to 8, characterized in that the extrusion openings are arranged in a longitudinal form, preferably in the shape of a rectangle, a curve, a ring or a ring segment, wherein the longitudinal form preferably has an aspect ratio of 100:1 to 2:1, preferably 60:1 to 5:1 or 40:1 to 10: 1.

10. Method or device according to any of claims 1 to 9, characterized by the further step of: drawing the coagulated filaments from the coagulation bath, deflecting the filaments outside the coagulation bath with or without further bundling with other coagulated filaments, feeding the filaments onto a drawing device and/or a drawing device, subsequently conveying the filaments/extrudate to a filament receiving unit, washing and drying the filaments, wherein preferably the following further optional steps are provided: finishing, dyeing, crosslinking, ultrasonication, cutting and/or taking up the filaments/extrudates.

11. Method or device according to any of claims 1 to 10, characterized in that the diameter of the extrusion opening is 30 to 200 μ ι η, preferably 50 to 150 μ ι η or 60 to 100 μ ι η.

12. Method or device according to any of claims 1-11, wherein the extrusion opening is arranged within a length LL and the deflection width L is at least 80%, preferably at least 90%, of the length LL.

13. A process for preparing solid cellulose filaments from a cellulose fluid, the process comprising the steps of: extruding the fluid through a plurality of extrusion openings, thereby forming fluid filaments, preferably passing the fluid filaments through an air gap; and solidifying the filaments in a coagulation bath, wherein the filaments are bundled and deflected in bundles in the coagulation bath so as to be drawn out of the coagulation bath above the coagulation bath level, characterized in that the extrusion opening is arranged within a length LL and the bundle of filaments resting on the deflection means occupies a deflection width L, which is at least 80% of the length LL.

14. Apparatus for performing the method of claim 13, the apparatus comprising: an extrusion plate with a plurality of extrusion openings, a collection container for receiving a coagulation bath, preferably a gas gap arranged between the extrusion openings and the collection container, a deflection device arranged in the collection container for deflecting the fiber bundles from the collection container, and a bundling device which determines a deflection width L of the filament bundles on the deflection device, characterized in that the extrusion openings are arranged within a length LL and the filament bundles on the deflection device occupy a deflection width L which is at least 80% of the length LL.

15. Method or device according to one of claims 1 to 14, characterized in that the filament bundle occupies a deflection width L on a deflection device arranged outside the coagulation bath, preferably at least during a first deflection after the filaments emerge from the coagulation bath and/or at least during a deflection in the drawing-off device_{Exterior part}Controlling said deflection width L according to the following formula_{Exterior part}：

L_{Exterior part}>(2x LZ x cos(B/2)x v^2.5)/(10x c_cell ^0.5x Q)，

Wherein L is_{Exterior part}Is the deflection width of the strand in mm, LZ is the number of extrusion openings, B is the deflection angle calculated as 180 DEG minus the wrap angle of the filament around the deflection device, expressed in degrees, v is the velocity of the filament in meters per second, c_cellQ is a dimensionless load number, where Q is 300 or less, for the cellulose concentration in mass% of the extruded fluid.

Technical Field

The present invention relates to the formation and treatment of extruded and subsequently cured synthetic fibers.

Background

The cellulose can be dissolved in an aqueous solution of an amine oxide, in particular in a solution of N-methylmorpholine-N-oxide (NMMO), to produce spinning products, such as filaments, staple fibres, films and the like, from the resulting spinning solution. This is achieved by precipitating the extrudate in water or a dilute amine oxide solution after transferring the extrudate from the extruder into the precipitation bath via the gas gap. Typically, cellulose solutions in the range of 4% to 23% are used to prepare extruded products. In a further process, the precipitated extrudate in the form of a film or filament strand is conveyed onwards, wherein a suitable roll-drawing machine provides the required drawing force (in the air gap). This process is also referred to as the lyocell process, and the cellulose filaments thus obtained are correspondingly referred to as lyocell filaments.

Document US 4,416,698 relates to a process for extruding and spinning a cellulose solution to form cellulose filaments. In this process, a fluid spinning material (a solution of cellulose and NMMO (N-methylmorpholine-N-oxide) or other tertiary amine) is shaped by extrusion and then transferred to a precipitation bath for solidification and expansion.

Documents US 4,246,221 and DE 2913589 describe processes for the preparation of cellulose filaments or films, in which the cellulose is drawn in fluid form.

Document WO 94/28218 a1 describes a process for preparing cellulose filaments, in which a cellulose solution is shaped into a plurality of strands by means of a nozzle. The strands are then transferred into the precipitation bath through a gas circulation gap and the strands are continuously filtered off in the precipitation bath.

Document CA2057133a1 describes a process for preparing cellulose fibers in which a dope is extruded and introduced via an air gap into a cooled water bath containing NMMO.

Document WO 03/014432 a1 describes a precipitation bath with a central fiber discharge arranged below the cover plate.

Document EP 1900860 a1 describes a two-stage coagulation bath of a spinning apparatus, wherein the baths may have different H₂SO₄A composition is provided.

Document WO 97/33020 a1 relates to a process for producing cellulose fibres, in which a solution of cellulose in a tertiary amine oxide is extruded through the spinning orifices of a spinning nozzle, the extruded filaments are guided through an air gap, a precipitation bath and through a drawing device which draws the filaments, and the drawn filaments are then treated to form cellulose fibres, wherein during the treatment the drawn filaments are subjected to a tensile load of not more than 5.5cN/tex in the longitudinal direction.

Document DE 10200405 a1 describes a lyocell device with a blowing device arranged in the gas gap. Mention is made therein of a precipitation bath device in which a curtain of filaments is immersed in the precipitation bath, deflected in the precipitation bath and leaves the precipitation bath in an obliquely upward direction, so as to be transferred to a bundling device. Since a single strand bundling is used here, a strong bundling can be expected during deflection.

Document WO 02/12600 describes a spinning method in which the most economical spinning speed can be calculated based on the fibre titer, the number of spinning holes and variable operating parameters using a formula.

Document WO 02/12599 describes a spinning process in which a curtain of filaments is deflected in a coagulation bath and subsequently combined in a punctiform manner.

Document WO 96/20300 describes the deflection angle of the filaments in the lyocell process calculated according to the formula.

The problem of filament damage during drawing is addressed in WO2008/019411a1 and solved by means of a mechanical drawing device arranged in the spinning bath, wherein said drawing device should also provide a partial drawing force that is active during operation. In addition to the structural complexity, another noteworthy drawback is that the very thin individual filaments can become entangled in the mechanical structure and thus can functionally impair both the spinning process and the mechanical device itself.

Document WO2014/057022 describes a series of spinning baths comprising different media.

Disclosure of Invention

In the currently applied lyocell process, all individual filaments (individual extrudates) directly adjoining a deflection means (e.g. a rod) are pressed against the deflection means by a normal force generated by the tensile force of the entire bundle. This can lead to tearing and filament breakage due to frictional resistance. In particular in the case of intensive bundling, the high normal forces resulting from the total drawing force are exerted only on a few individual filaments which are in direct contact with the deflection device. These few individual filaments are severely damaged by high frictional loads, especially at high draw speeds. This is exacerbated by the fact that: the filaments swell in the coagulation bath and may still be at high temperatures, which reduces their mechanical strength.

It is therefore an object of the present invention to minimize the frictional load exerted on each individual filament at the deflection point, thereby contributing to higher production rates and higher spinning speeds. Such friction occurs in the spinning bath where the medium used requires the use of: rigid deflection means or deflection means with a driven or freely rotating roller, for example in a filament drawing device.

The invention allows: evaluating the system according to a calculation in terms of the frictional load exerted on the filaments; and determining appropriate measures to adjust the system in such a way that the frictional load exerted on all filaments in direct contact with the deflection means can be kept at a minimum level.

Another object of the invention is to ensure manual manageability of the filament curtain and accessibility to deflection points in the treatment zone between the spinning nozzle and the drawing device without the need to use highly complex and delicate splicing aids or drawing devices.

The present invention provides a process for preparing solid cellulose filaments from a cellulose fluid, the process comprising the steps of: extruding the fluid through a plurality of extrusion openings, thereby forming fluid filaments, preferably passing the fluid filaments through an air gap; and solidifying the filaments in a coagulation bath, wherein the filaments are bundled and deflected in the form of a bundle in the coagulation bath so as to be drawn out of the coagulation bath above the coagulation bath level, wherein the bundle of filaments occupies a deflection width L on the deflection device, the deflection width L being controlled according to formula 1:

L>(2x LZ x cos(B/2)x v^2.5)/(10x c_cell ^0.5x Q), the formula 1,

where L is the deflection width of the bundle in mm, LZ is the number of extrusion openings, B is the deflection angle (calculated as 180 minus the wrap angle of the filaments around the deflection device in degrees), v is the draw speed of the filaments in meters per second, c_cellIs the cellulose concentration in mass% of the extruded fluid, and Q is a dimensionless load number, wherein Q is 15 or less. In the formula 1, ">"has the meaning of" greater than, "x" is the multiplication symbol, and "cos" refers to the cosine.

The invention further relates to a device suitable for carrying out the method, comprising: an extrusion plate with a plurality of extrusion openings, a collection container for receiving a coagulation bath, preferably a gas gap arranged between the extrusion openings and the collection container, a deflection device arranged in the collection container for deflecting the filament bundle from the collection container, and a bundling device for determining a deflection width L of the filament bundle on the deflection device, wherein the filament bundle on the deflection device occupies a deflection width L corresponding to the above-mentioned formula 1, wherein L, LZ, B, v, c_cellAnd Q is as defined above, Q is 15 or less, v is at least 35m/min, thereby making the device suitable for use.

According to the invention, there is generally a large deflection width L; accordingly, the present invention also relates to a process for preparing solid cellulose filaments from a cellulose fluid, said process comprising the steps of: extruding the fluid through a plurality of extrusion openings, thereby forming fluid filaments, preferably passing the fluid filaments through an air gap; and solidifying the filaments in a coagulation bath, wherein the filaments are bundled and deflected in the form of bundles in the coagulation bath so as to be drawn out of the coagulation bath above the coagulation bath level, wherein the extrusion opening is arranged within a length LL and the bundle of filaments occupies a deflection width L on the deflection device, the deflection width L being at least 70% of the length LL. Similarly, the invention also relates to a device suitable for carrying out said method, said device comprising: an extrusion plate with a plurality of extrusion openings, a collection container for receiving a coagulation bath, preferably a gas gap arranged between the extrusion openings and the collection container, a deflection device arranged in the collection container for deflecting the filament bundles from the collection container, and a bundling device which determines a deflection width L of the filament bundles on the deflection device, wherein the extrusion openings are arranged within a length LL and the filament bundles on the deflection device occupy a deflection width L which is at least 70% of the length LL.

The following detailed description relates to apparatuses and methods in equivalent measure, i.e. the preferred method features also correspond to the characteristics or suitability of the apparatus and/or its individual components, and the preferred apparatus features also correspond to the apparatus employed in the method according to the invention. All preferred features may be combined unless explicitly stated otherwise. All method features including the above method features may be combined. All device features including those described above may be combined.

Drawings

Fig. 1 shows a liquid treatment zone in the form of a spinning funnel 6.

Fig. 2a shows a spinning slot system in combination with a rectangular spinning nozzle arrangement.

Fig. 2b shows a spinning slot system in combination with an annular spinning nozzle arrangement 5 and a straight deflection device 2.

Fig. 2c shows a spinning channel system in combination with an annular spinning nozzle arrangement, wherein an annular extrudate curtain is deflected at a deflection angle B' via an annular deflection device and the deflected extrudate curtain is drawn off from the spinning bath in a vertically upward direction along the central axis of the annular nozzle arrangement.

Fig. 3a shows a trough system for deflection and bundling. The spinning curtain having a width L and a deflection angle B is deflected at the collecting device.

Fig. 3b shows a trough system with two deflection devices, wherein (in contrast to fig. 3 a) no bundling is performed at the second deflection device. The spinning curtain having a width L and a deflection angle B is deflected at the second deflection device.

Fig. 3c shows a slot system with three spinning curtains deflected at a common deflector located in the slot and at separate deflectors located at the slot edges, where the three bundles are drawn out as indicated by the arrows.

Fig. 4a and 4b show the deflection device in the drawing frame in a top view (left) and a side view (right), with the drive roller indicated by "M". It may be provided that all rollers are driven (fig. 4a) or that some rollers are driven (fig. 4 b). The arrows indicate the transport of the bundle of filaments. The beam is deflected at the roller at an angle B (0 ° to 150 °). "L" represents the width of the filament bundle at the roll.

Detailed Description

The invention relates to the deflection of a filament curtain or of a bundle of filaments bundled at least on one side. Deflection is effected in the coagulation bath, so that the filaments are conveyed out of the bath. During deflection, the filaments merge perpendicularly to the deflection axis, so that the filaments in a first layer rest on the deflection device, while the filaments in the other layers rest on each other in layers. As already mentioned, this puts a certain stress on the material, especially at high speeds. According to the invention, the deflection width is enlarged so that the filaments can be drawn at an arbitrary speed (i.e. a high speed of, for example, 35m/min or more).

In the deflection process according to the invention, the thread is guided in a wide band. Thus, the term "bundle of filaments" includes a band of co-guided filaments having a cross-sectional width and height with the width being greater than the height.

The above formula 1, in which Q is 15 or less, relates in particular to a deflection process carried out in a coagulation bath, wherein the filaments are particularly susceptible to the frictional forces mentioned in the summary of the invention (which are caused by temperature and swelling). The coagulation bath represents a partial treatment zone for the extruded filaments. According to the lyocell process, the filaments have not yet acquired their final structure and stability at this point. Initially, the structure and stability changed due to stretching (especially in the gas gap) and solvent exchange (especially in the coagulation bath). The material may still change after withdrawal from the coagulation bath such that the path covered by the filaments/extrudates (including the drawing equipment) between the exit from the spinning nozzle and the step of washing off the solvent from the filaments/extrudates is referred to as the treatment zone. Since the extruded filaments have not yet attained their final form, they are referred to as "extrudates" while still in the treatment zone. The drawing device is a device that provides the deforming forces required for filament formation, as well as the frictional forces acting on the filaments/extrudate during transport from the spinning nozzle to the drawing device. Since hydrodynamic conditions prevail in coagulation baths, there is a very high risk of entanglement when using driven or freely rotating deflection means, so that preferably fixed deflection means are used in coagulation baths. However, outside the coagulation bath, fixed deflection means should be possible to provide only a slight deflection, or freely rotating deflection means and/or driven deflection means should be used. By using a freely rotating deflection device and/or a driven deflection device, the filament/extrudate will not be susceptible to friction effects, so that a smaller deflection width L as calculated according to equation 1 may also be employed. However, a certain width will still be maintained, in particular for the deflection process at the drawing device, since here too friction effects occur. Depending on the throughput (per extrusion opening), the drafting equipment ensures that the required drafting speed is provided. The drawing apparatus imparts a drawing speed to the filaments/extrudates by means of a driven deflection device or devices, such as a spool or roller. In this case, the deflection force of the reel is first transferred to the inner filament/extrudate (in direct contact with the reel/roller) and then the force is transferred to the outer filament/extrudate (not in direct contact with the reel/roller). Thus, the strain on the inner filament/extrudate is greater than the strain on the outer filament/extrudate. According to the invention, this imbalance is minimized by: the deflection width is maintained to the extent that the inner filaments/extrudates are only covered by a limited number of outer filaments/extrudates, thereby maintaining fast and efficient operation. The extrusion openings may be holes or orifices and capillaries provided in the extrusion plate. For all these cases, the number of extrusion openings is referred to as the hole number. The drawing-off process can be carried out in a gas compartment into which the filaments are introduced on leaving the coagulation bath.

According to the invention, the deflection device is a machine component which can change the direction of the individual extrudates, extrudate curtains or extrudate bundles, wherein the deflection width L of the deflected curtain itself is preferably not influenced by the deflection device.

In principle, such a deflection device can also be implemented as a rigid deflection device or as a rotary deflection device. The rotary deflection means may be driven or non-driven. The rotating deflection means provides the advantage of reducing the friction between the extrudate and the deflection means, so that the deflection can be performed in a very gentle manner when transferring forces from the deflection means to the filaments/extrudate, except in the case of deflection in a drawing apparatus. However, a disadvantage of the rotary deflection device is that the individual extrudates may stick to the rotary deflection device due to their stickiness, thus possibly leading to tangling, tearing and other failures. The use of rotating deflection devices in liquids (in coagulation baths) is also problematic, since hydrodynamic vortices in the surface region of the deflection device cause a high risk of dragging individual extrudates along the circumference of the deflection device, again possibly leading to tangling, tearing and other failures.

In the case of spinning bath liquids and viscous, wetting or other coherent extrudate curtains or bundles, it is preferred to use rigid deflection means, for example in the form of rods, bobbins, cage deflection means or any other suitable form of rigid deflection means.

Any material having the lowest possible sliding friction value may be considered as a material for the rigid deflection means. Besides metals (coated or uncoated), textile ceramics or synthetic materials are also conceivable.

Preferably, a deflector is used in the coagulation bath. It is also possible to provide two or more deflection devices in the coagulation bath, thereby increasing the number of options for a (larger) deflection angle B per deflection device. According to the invention, the requirements according to equation 1 are met by a first deflection device, preferably also a second deflection device or each deflection device, in the coagulation bath. In this context, "first", "second", etc. refer to the respective procedural proximity with respect to the extrusion process and the order in which the filaments/extrudates pass through the deflection means.

Furthermore, in the treatment zone after the coagulation bath, the filaments/extrudates are kept in the form of a band with a certain deflection width; also at this time, particularly in drafting equipment, frictional forces are generated which may lead to damage during deflection. However, the deflection width after the coagulation bath can be kept narrower than in the coagulation bath itself, since the negative influence on the filament stability caused by temperature and swelling is not too pronounced here. According to the invention, the deflection process outside the coagulation bath is preferably at least as wide as the deflectionDegree L_{Exterior part}Is carried out by deflecting the width L_{Exterior part}Corresponds to the division of L by 30, preferably by 20, preferably by 10, particularly preferably by 5, according to formula 1 (Q.ltoreq.15) and/or the filament bundle is preferably held at the width L_{Exterior part}(also between deflection processes) -at least until the drafting device and/or the cleaning device is entered. Alternatively, L may be calculated according to equation 1_{Exterior part}Where Q may have a higher value, for example, Q ═ at most 300 or at most 250, e.g., 10 to 300 or 40 to 250. In the cleaning device, the filament bundle is generally spread more widely, thereby facilitating the cleaning process. For example during cleaning, L_{Exterior part}But may also be at least L according to equation 1(Q is at most 15).

L_{Exterior part}(deflection width or bandwidth outside the coagulation bath) can also be defined independently of L according to equation 1. L is_{Exterior part}Preferably selected so that the filament density per mm deflection width achieved at a given drawing speed is not more than 7000dtex/mm, preferably not more than 6000dtex/mm, not more than 5000dtex/mm, particularly preferably not more than 4000 dtex/mm.

The deflection width or band width L outside the coagulation bath is preferably maintained during the deflection process immediately after the withdrawal of the filaments/extrudates from the coagulation bath, in which case the filaments/extrudates are still very soft_{Exterior part}And/or maintaining a deflection width or bandwidth L outside the coagulation bath in a drawing device, in which the filaments/extrudates are particularly stressed by force transmission_{Exterior part}. The bundle of filaments preferably always maintains a minimum width L upon leaving the coagulation bath and during passage through the entire treatment zone or during the entire processing of the filaments/extrudates_{Exterior part}Until the final product is cut and/or rolled. The processing typically includes the following steps: spinning in a coagulation bath (as described above), drawing off from the coagulation bath, drawing off by means of a drawing device, washing, drying, winding up and/or cutting the filaments as end product.

The spinning process comprising processing may alternatively or additionally comprise the steps of: extruding the filaments/extrudates through a spinning nozzle, guiding the filaments/extrudates through a gas gap (preferably into which a gas stream is injected, see above) and into a coagulation bath (precipitation bath), deflecting the filaments/extrudates in the precipitation bath (preferably by means of a deflection device arranged opposite the spinning nozzle), withdrawing the coagulated filaments/extrudates from the coagulation bath, deflecting the filaments/extrudates outside the coagulation bath and further optionally bundling the filaments/extrudates which have not coagulated with one another, feeding the filaments/extrudates onto a drawing apparatus (also referred to as drawing equipment or drawing device) and/or a drawing device, subsequently conveying the filaments/extrudates to a filament receiving unit and/or drawing gear, cleaning, drying and optionally further steps (as required). The device according to the invention is provided with corresponding equipment. In another embodiment, the method may comprise the steps of: extruding the filaments/extrudates through a spinning nozzle, guiding the filaments/extrudates through a gas gap (preferably into which a gas stream is injected, see above) and into a coagulation bath, deflecting the filaments/extrudates outside the coagulation bath, subsequently bundling or combining them with other filaments/extrudates, feeding the filaments/extrudates onto one or more drawing devices, washing, drying and optionally further steps and/or devices, as required.

Some steps may be combined; for example, the washing step may be performed in a drawing device. Embodiments as detailed or preferred herein may be used in each step. It is also possible to combine a driven roller or reel and a non-driven roller or reel in one drafting device, as described for example in document CN 105887226 (a). Heat treatment (e.g. drying) as described in, for example, CN 205133803U may also be carried out in the drawing equipment. In the start-up phase of the method, a splicing aid as described in, for example, CN 205258674U may be used; however, this is only an auxiliary step and is not necessary.

Other steps or means may be provided which are suitable for the purpose according to the invention. For example, a drying step may be carried out after the washing step, or a drying device may be provided downstream of the washing device, wherein one or more further treatment steps (e.g. finishing the filaments/extrudates) may be carried out before the drying process or upstream of the drying device, or a corresponding finishing device may be provided. Furthermore, other processing steps such as dyeing, crosslinking, ultrasound treatment can be carried out before the drying step, i.e. appropriate devices can be provided.

At any point prior to the drying step in the process, it may be preferable to insert a cutting device (for cutting) or a take-up device (for taking up) to produce staple fibers or continuous yarns from continuous fibers.

Preferably, a stretching force of less than or equal to 3cN/dtex, preferably less than or equal to 2cN/dtex or less than or equal to 1.5cN/dtex is exerted on the filaments/extrudates in the drawing equipment.

The filament bundles of multiple spinning points may be combined to form a combined bundle. Typically, this combination is performed (immediately) upon exiting the coagulation bath, thereby enabling downstream equipment components (e.g., drafting devices or cleaning devices) to process the combined bundle. Herein, the width L or L_{Exterior part}Given primarily with reference to one spinning point, and increase accordingly when combined. For example, L per spinning point_{Exterior part}May be at least 8mm, for example 8mm to 100mm, preferably 12mm to 70 mm.

A bundling means is a machine component that narrows the deflection width of the extrudate curtain according to the geometry of the bundling means, so that an extrudate bundle is formed from a planar or tubular or circular or other shaped extrudate curtain. Optionally, the bundling means also forces a change of direction of the formed extrudate bundle. Therefore, the bundling means may also mean a deflecting device according to the rules and preferred embodiments of the present invention. Similar to the description of the deflection device, the bundling means can be embodied as rigid means or as rotary means. The same material may be used. For use in spinning bath liquids, and in the presence of a curtain or bundle of viscous, wetting or cohesive extrudate, rigid bundling means in the form of rods, bobbins, cage deflection means, hooks, loops, U-shaped guides, or any other suitably designed means will preferably be used.

The load factor Q is an empirical measurement of filaments stacked on top of each other at the deflection device. The lower Q, the gentler the process, and the larger L must be chosen. In the coagulation bath, Q should be 15 or less, preferably Q is 12 or less, preferably 8 or less or 5 or moreIs small. In this connection, Q is 2 or higher, preferably 3 or higher or 4 or 5 or higher, with Q of 2 to 15 or more preferably 4 to 12 being particularly preferred. Possible values for Q are 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or any other value in between. As already mentioned above, Q may be higher outside the bath. In this case, L is changed to L_{Exterior part}Wherein Q is at most 300. Unless specifically stated otherwise, Q relates to the deflection process that takes place in the coagulation bath.

The number of extrusion openings (also called the number of holes, abbreviated to "LZ") determines the number of filaments that must be deflected. In particular, the specifications of the process according to the invention are suitable for large industrial scale. The number LZ of extrusion openings is preferably 2000 or more, preferably 5000 or more or 10000 or more. Independently or in combination, the LZ may be 500000 or less, preferably 200000 or less, 100000 or less or 50000 or less. If it is desired to produce a greater number of products simultaneously and therefore a greater number of filaments, it is possible to use a plurality of extrusion devices according to the invention to produce a plurality of parallel filament bundles or curtains, optionally in a coagulation bath used together or even in the case of one deflection device used together. The above-mentioned hole numbers relate to co-deflected and bundled filament bundles or groups.

The deflection angle B is determined by the angle at which the filaments transferred to the deflection device and the deflected filaments are wrapped (see figure). A sharper angle will result in stronger shear and friction forces acting on the filaments. The sharper the angle, the more L must be increased (while the other parameters of equation 1 remain unchanged). Preferably, the deflection angle B is an angle of 10 ° to 90 °, preferably 20 ° to 60 ° or 25 ° to 45 °. Angle B relates to the deflection process that takes place in the coagulation bath, unless explicitly stated otherwise. Outside the coagulation bath, for example in the drawing-off device and/or the cleaning apparatus, the deflection angle can be 0 ° to 150 °, in particular any angle within the stated range (as already indicated), for example for angles in the coagulation bath.

According to the invention, a large deflection width L allows high drafting speeds. The filaments are usually drawn through a coagulation bath by means of a drawing device. The drawing-off device itself is usually arranged outside the coagulation bath, downstream of the deflection device and optionally downstream of the bundling device. The corresponding deflection width L is selected according to the drafting speed. Preferably, the drafting speed (at the deflection means) is at least 35 m/min. The drawing speed v may be 36m/min or more, preferably 40m/min or more or 45m/min or 50m/min or more. Independently or in combination, the drawing speed v may be 200m/min or less or 150m/min or less.

In the process according to the invention, an extrusion medium in fluid form is used. The fluid is preferably a solution or mixture of cellulose and other media components (e.g., solvents). The cellulose concentration is chosen as is usual for the lyocell process. Thus, the cellulose concentration c of the extruded fluid_cellIt may be from 4% to 23%, preferably from 6% to 20%, in particular from 8% to 18% or from 10% to 16% (all percentages referring to mass%). The extrusion medium usually used in the lyocell process is a cellulose solution or melt with NMMO (N-methylmorpholine-N-oxide) and water, as described in the introduction. Other solutions of cellulose, in particular ionic solvents of cellulose, may also be used. Ionic solvents are described, for example, in document WO 2006/000197 a1 and preferably contain an organic cation, for example an ammonium, pyrimidine or imidazolium cation, preferably a1, 3-dialkylimidazolium halide. Also in this case, water is preferably used as solvent additive. Particularly preferred are solutions of cellulose with butyl-3-methylimidazolium (BMIM), which for example has chloride as counter ion (BMIMCl), or 1-ethyl-3-methylimidazolium, also preferably in the form of the chloride, and water.

The step of passing the fluid filaments through the gas gap in the process according to the invention or the setting of the gas gap of the device according to the invention is optional, i.e. the gas gap may be set or not. This step/measure distinguishes between wet spinning processes and dry-wet spinning processes. In the case of wet spinning, the filaments are introduced directly into a coagulation bath. In the case of dry-wet spinning, a gas gap is provided and the filaments are passed through the gas gap before being introduced into the coagulation bath.

Optionally, a gas stream can be injected into the gas gap (and preferably, in particular, in large industrial-scale plants), for which purpose a blower is provided in the apparatus. The temperature of the injected gas stream is preferably 5 ℃ to 65 ℃, preferably 10 ℃ to 40 ℃. The fluid material may be extruded at a temperature of 75 ℃ to 160 ℃. Preferably, the gas gap is maintained at a lower temperature than the extruded fluid material. In particular, the gas flow in the gas gap is maintained at a lower temperature than the extruded fluid material.

The gas gap itself (i.e. the distance between the extrusion opening and the coagulation bath) and/or a container suitable for this purpose (e.g. a tank) may preferably have a length of between 10mm and 200mm, in particular between 15mm and 100mm or between 20mm and 80 mm. Preferably, the length is at least 15 mm. The gas present in the gas gap is preferably air. The gas flow is preferably an air flow, however other inert gases may be used. The term "inert gas" refers to a gas that does not chemically react with the fluid filaments in the gas gap, and preferably does not chemically react with the coagulation medium (e.g., water or dilute aqueous NMMO solution) nor with other solvent components, depending on the extrusion medium used.

In the wet spinning process, the treatment zone essentially consists of a liquid container, a liquid funnel or a liquid channel. The extrudate emerging from the spinning nozzle is introduced directly into the spinning bath liquid for precipitation and/or cooling. The wet (precipitated and/or cooled) extrudate is then transferred to a cleaning bath and/or to a drawing device (via a gas compartment or an air compartment).

In the dry-wet spinning process, the treatment zone essentially consists of a gas gap or air gap and a downstream liquid container, liquid funnel or liquid channel. The extrudate emerging from the extrusion opening passes through a gas gap and, in the further course, through a coagulation bath (which is also referred to as spinning bath). The wet (precipitated and/or cooled) extrudate is transferred to the drawing equipment through one or more cleaning baths and/or through a gas compartment or an air compartment.

Wet or dry wet spinning processes are characterized by the generation of turbulence and vortices due to displacement and drag interactions between the coagulation bath liquid and the extrudate at relatively high velocities. In case a deflection point with a rigid deflection means is used, there is an additional risk of drying out at the contact point between the extrudate and the deflection means. The risk of drying increases proportionally with the drawing speed and the amount of pressure exerted on the curtain or bundle of extrudates, which presses it against the deflection means.

The extrusion openings are preferably arranged in a longitudinal shape, so that the extruded filaments are formed into a geometry that facilitates deflection and bundling during deflection. The longitudinal arrangement of the extrusion openings therefore preferably also corresponds to the longitudinal direction of the deflection device. Thus, said longitudinal direction of the deflection means preferably corresponds to the deflection axis (or, in case curved deflection means are used, follows a plurality of deflection axes). The extrusion openings may be arranged in a rectangular, curved, annular or ring-segment-shaped manner. The aspect ratio of the longitudinal form may be from 100:1 to 2:1, preferably from 60:1 to 5:1 or from 40:1 to 10: 1.

The extrusion openings preferably have a diameter of 30 μm to 200 μm, preferably 50 μm to 150 μm or 60 μm to 100 μm, and are therefore advantageous for the production of filaments suitable for use in (woven and non-woven) textile products.

The extrusion throughput is preferably adjusted to give a linear density of the individual fibers obtained of 1.3 dtex. + -. 50%, preferably. + -. 25% or. + -. 10%, at a given drawing speed. The extrusion throughput can be adjusted by adjusting the pressure of the extrusion material (i.e. the cellulose solution). Examples of possible pressures are 5 to 100 bar or preferably 8 to 40 bar.

Particularly preferred is an overall larger deflection width L, which is also in the sense of a separate main feature of the invention and independent of equation 1. Whether dependent on equation 1 or independent of equation 1, the extrusion openings may be arranged along the length LL, wherein according to this feature of the invention the deflection width L is at least 70%, preferably at least 80% or at least 90% of the length LL. The deflection width may also be equal to the length LL or even greater, for example 110% or greater of the length LL. L is_{Exterior part}Preferably at least 1%, at least 3%, preferably at least 5% or at least 10% of the length of LL. Based on the purpose of bundling, L_{Exterior part}Preferably minimum length LL50% of the total. All method parameters and associated device settings according to the invention can be combined. For example, a particularly preferred combination is a drawing speed v of 40 to 150m/min and a load factor Q of 4 to 13 or 5 to 12. All values described herein within or outside these ranges are of course also possible.