CZ230596A3 - Spinning apparatus - Google Patents

Abstract

A container (1') holds fluid for a spinning bath in which a dry-wet spinning process takes place. Here there is in the container a direction changing agent (2') for the extruded filaments and their gathering together. This agent can be swung in the vertical plane. Also claimed are (A) the process which entails the extrusion of a polymer dope through a spinneret (7') with high perforation density into a gaseous medium to form an array of filaments which are then drawn into the bath fluid, gathered in a bundle and led via the direction changing agent, where the distance of the direction changing agent from the spinneret is such that the angle between the outermost filaments of the array and the vertical through the spinneret does not exceed 20 degrees ; and (B) the application of the container to the process where a plastic soln. of cellulose in aq. tertiary amino oxide is spun.

Description

The dry / wet spinning technique is quite generally based on the spinning mass being extruded.

through a forming tool, such as a spinneret, into a non-shrinking medium, such as air or an inert gas, and when a spinneret is used, filaments are formed which are stretched in the medium during consolidation and subsequently fed into the spinning liquor (precipitation bath; in which the filaments coagulate.

An amine oxide process for forming cellulose-shaped tertiary amine oxide. In doing so, from a tertiary amine oxide. and forming tool and guided generally, bodies are understood to include those in the composition.

welded in which cellulose dissolves water, the solution is an aqueous precipitation bath, r

* · Ί

Λ = e cellulose precipitates. N-methylmorpholine-N-oxide (ΝΙΊΜΟ) is primarily used as the amine oxide. Other amine oxides are described, for example, in EP-A-0 553 070. A method for producing ductile cellulose solutions is known, for example, from the specification. EP-A

- 0 35O 419.

The operation of the amine oxide process according to the dry / wet spinning process is known, for example, from the specification

DE-A-29 13 5S9.

WO 93/19230 and WO 95/04173 disclose a preferred embodiment of the amine oxide process and the cellulose fiber production apparatus according to which the cellulose solution is shaped in a warm tertiary amine oxide and the shaped solution is fed through a gaseous medium (air) into a precipitating bath to precipitate the cellulose contained therein, wherein the warm, shaped solution is cooled before being fed into the precipitating bath. The cooling is carried out immediately after shaping and consists essentially in the horizontal air blowing of the cellulosic molding body. The method of the invention allows spinning of a high fiber density cellulose solution without sticking the spun fibers after exiting the spinneret.

it also relates to the process of both cellulose amine oxide fibers. Also by spinning into air

L with spinneret.

bath, when strengthening the bath. In BD-A

DD / A-218 121 of dry / wet spinning in the manufacture of cellulosic solutions in tertiary of this method is a cellulose solution gap, which is the distance between and the surface of the spinning liquid stretched and led to an aqueous precipitator.

21S 121 is mentioned that the air gap can be shortened without disadvantageous spinning safety if polyalkylene ether is added to the cellulose solution prior to spinning. A small air gap is preferred because the risk of sticking of freshly extruded films is reduced.

EP-A-0 574 870 describes a dry / wet spinning process for treating cellulose solutions in a tertiary amine oxide and points out the advantage of a small air gap. In this spinning process, it is possible, according to the description in this specification, to spin at a small air gap and with a large number of spin holes per unit area. Despite these data, the spinning process should not adhere to the filaments. It is recommended to contact the spiked filaments with the spin bath liquid in the spinner funnel. In a uniform flow with the filaments, the liquid for the spinning bath is guided through the spinning funnel. The axis of the spinneret is substantially perpendicular to the plane of the spinneret, and the flow of liquid for the spinning bath is directed from top to bottom, the flow generally being generated by the free fall of liquid for the spinning bath.

According to EP-A-0 574 870, the elongation or stretching during consolidation of the freshly extruded filaments is achieved in such a way that ⁴ filaments are accelerated to their draw-off velocity by the spinning liquid flowing through the spinning funnel.

This previously known spinning apparatus has the fact that the spinning funnel tube, by virtue of its small diameter, imposes a disadvantage to the bundle to be formed, reliately outside the filaments.

In view of its overall cross-section, the upper limit is still set to an unsatisfactorily low level for a highly technical embodiment of the process. Thus, according to the applicant's experience, the present application is at a diameter of 6 mm, as stated in EP-A-0 574 870, it is only possible that the filament bundle consisting of a maximum of 100 filaments can be guided through the funnel, since the spinning liquid must also be transported through the funnel. This in turn means that when using such a spinning funnel, only a spinning nozzle with a maximum of 100 coolant holes can be used.

If, on the other hand, a wide spinnerette is used with thousands of coolant orifices, as described in the applicant's Austrian patent AT-B 397.392, for example, the funnel tube must be correspondingly larger, which in turn must drain and circulate much more spinner liquor. This large amount of spin bath liquid leads to turbulent flows in the spin bath, which disrupts the dry / wet spinning process.

GB-A ~ 1,017,855 discloses a dry / wet spinning apparatus for synthetic polymers. Here too, it is recommended to use a spinning funnel through which the spin bath liquid flows in a uniform stream with the extruded fibers. The spinnerette is located approximately 0.5 cm above the surface of the spin bath.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a spinning device which allows the amine oxide process according to the dry / wet spinning process to be machine-friendly yet practicable with good spinnability (high spinning safety), while good spinnability is understood as possible high, maximum attainable end-take (= least possible titer) before fiber breakage- Another measure of wettability is the time during which it can be spinning without any spinning error requiring technical assistance. The use of high density hole wound nozzles alone avoids the sticking of freshly extruded filaments in the air gap and achieves as constant a titer as possible (slight titer variations).

The essence of the invention

Spinning device for carrying out the amine oxide process.

according to the dry / wet spinning method

- a spinnerette having spinning holes for extruding the filaments,

- a blower - device by which the extruded filaments can be cooled immediately after leaving the spinning holes,

- spinning liquid tank,

- a bundling element which is intended to bundle the extruded filaments in the spin bath liquid, and

- the air gap, which is defined as the distance of the spinneret from the surface of the spin bath liquid, is characterized by:

-that the bundling element is located relative to the spinneret at a distance such that an angle <00, which produce the filaments to the normal to the surface of the spinning bath liquid is at most 45 ^6, and

- that the relation íh-l> is fulfilled

0.1 + 0.005 1 <= 0.7.da.

where da is the distance (mm) between the spinning orifice and its always adjacent spinning orifice on the spinneret, h is the distance (mm) of the spinner from the spinneret, and 1 is the air gap, wherein

0.4 mm < = d < = 2 mm, and mm < 1 < 60 mm.

It has been shown that the object of the invention can be solved if the spinning device used is designed in such a way that the above two criteria are met (maximum angle of 45 ° as well as the above-mentioned unevenness). however, the cooling of the extruded filaments immediately after leaving the winding nozzles is known to the person skilled in the art (see, for example, WO 95/04173 of the applicant).

A preferred embodiment of the winding device according to the invention is characterized in that the bundling element is designed as a return element on which the filaments are not only bundled but also turned.

It has proven advantageous to design the return element so that it does not rotate when the filaments are turned. According to this embodiment, neither the roller nor the roller is considered as a return element. As a result, the interrupted filaments are not wound on the return element. This facilitates the implementation of the amine oxide process.

Another preferred embodiment of the winding device according to the invention is characterized in that the angle c <does not exceed 20 ^e .

It has been shown that for the safety of spinning in the dry / wet spinning process,

Even if the angle of penetration of the .alpha. In the air gap is as small as possible and in particular does not exceed 20 ^DEG . Thereby, the risk of sticking the filaments in the space between the spinneret and the surface of the spin bath can be minimized and the spinning safety increased.

The invention also relates to a spinning apparatus for carrying out the amine oxide process according to the dry / wet spinning method

- a spinnerette having spinning holes for extruding filaments,

- a blower with which the extruded filaments can be cooled immediately after they have left

- spinning holes,.,. .. .. ... .. .. .. .. ......

- spinning liquid tank,

- a return element, which in the spin bath liquid is intended to bundle and invert the extruded filaments, and

An air gap defined as the distance of the spinneret from the spin bath liquid, characterized in that the return element is formed such that it does not rotate when the filaments are turned.

Another advantageous embodiment of the winding device according to the invention consists in that the spinnerette is provided;

- a nozzle body which is substantially rotationally symmetrical and has a cooling gas inlet at its center,

- inlet for cellulose solution,

- a circular spinner with welder holes, ®

an impingement plate for controlling the flow of cooling gas to the filaments which are extruded from the puff holes so that the flow of cooling gas extends substantially perpendicular to the

J filaments.

In this way, it can be spun with an even greater density of holes and at the same time it can effectively prevent freshly extruded filaments from sticking together in the air gap. Cooling the annular filament system by blowing with cooling air is known from WO 95/04173 of the applicant.

Another advantageous embodiment of the inventive winding device is that the reservoir containing the spinning bath liquid is in conjunction with a lifting device by means of which the reservoir can be moved vertically back and forth with respect to the spinneret, thereby changing the distance 1, and that the bundle element is arranged such that the distance h remains constant despite this movement.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention is further elucidated with reference to the accompanying drawings which show, in FIGS. 1, 2 and 3, the general dry / wet spinning, lubrication methods and quantities important for the relationship of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In Fig. 1, the spinning bath liquid reservoir is indicated by 1, the surface of the spin bath liquid being denoted by Xa. In the spinning process, the spinning mass is extruded through the spinneret 2 and the extruded filaments 4, 5 are

I are drawn through the air gap X into the spin bath liquid in which they coagulate. On the return element 2, which is a non-rotatable, cylindrical rod, the coagulated filaments are bundled, inverted and angled upwards. The air gap X is defined as the distance of the underside of the spinneret 2 from the surface X1 of the spin bath liquid. The angle defined above by the filaments relative to the perpendicular to the surface of the spin bath liquid is denoted by C. '' '”

Reference numeral 4 denotes a filament that originates from a winding orifice located at the outer edge of the annulus formed by the winding orifices in the spinneret 2. dL ± is the radius (mm) of the circle that outwardly delimits the annulus formed by the winding orifices. "Le" denotes the distance of this winding orifice to its adjacent winding orifice, wherein the distance between respective centers of two adjacent winding orifices, h, is the distance of the return element 2 from the spinneret 2, and L is the air gap.

According to the embodiment described in FIG. 1, the reservoir is on a lifting device (not shown here) which can move the reservoir X vertically and thus the size of the air gap X can be easily changed.

It has proven to be particularly advantageous that the return element is not fixed to the receptacle X, but is considered such that the receptacle X can be moved while the distance 4 remains constant. In this simple manner, the air gap can be varied while keeping the distance t1 constant

L. znamenáο means a substantial simplification in setting up the ¹ spinner according to the invention. Giant. 2 and 3 show embodiments of such a type of spinning device according to the invention.

Ϊ

Giant. 2 essentially shows the spinning apparatus of FIG. 1, wherein the same parts have been designated with the same reference numerals. The non-rotatable return element 2 is connected via a rigid arms 6 to a fixed element Z which is not connected to the reservoir, so that when the reservoir 1 is raised or lowered, the element Z does not move therewith. For example, the element Z may be a wall. 2 shows two positions of the reservoir 1, the lower position being indicated by dashed lines. Devices for lifting and lowering the reservoir 1 are not shown. It is clear from Fig. 2 that by lifting and lowering the reservoir 1, the air gap can be shortened or extended, while at the same time the distance h remains the same.

Giant. 3 shows a further embodiment of the spinning apparatus according to the invention. In this embodiment, the return element 2 is anchored by means of a rigid arm 2 on the floor S. The arm protrudes through a corresponding opening IX, which is considered in the container 1. In order not to lose any liquid from the reservoir 1, a casing which is simply clamped is provided for sealing, even if the reservoir 1 is lowered by means of a device (not shown).

The following Examples 1, 2, 3 and 4 illustrate the invention in more detail, with Examples 1 and 2 illustrating the effect of the angle α on the wettability of cellulose solutions. Example 4 illustrates the advantageous effect of the non-rotatable return element on wettability.

Example 11; A spinning apparatus substantially corresponding to FIG. 1 was used, but a spinning funnel according to EP-A-0 574 S70 was used as the bundling element.

The spinnerette used was that described in WO 95/04173, the disclosure of which is incorporated herein by reference.

This previously known spinning nozzle (number of holes: 3960, hole diameter 100 µm, outer diameter of nozzle (outer row of holes) d ± 145 mm) has a nozzle body formed substantially rotationally symmetrical and having a nozzle diameter. at its center a cooling gas inlet, a cellulose solution inlet (13, 57, cellulose, temperature 120 ° C), a circular, deep-drawn spinning stainless steel spinneret, which spinneret is tubular in cross-section; and an impingement plate for controlling the flow of cooling gas to the cellulosic filaments which are extruded from the spinning holes (discharge: 0.025 g / min) so that the flow of cooling gas (24 m ³ / h) extends substantially perpendicular to the extruded cellulosic filaments. the openings have a substantially uniform spacing between them (hole-to-hole distance da: 1000 µm) The air gap 1 was 15 mm long The air in the air gap had a temperature of 24.5 ° C and a water content of 4.5 g water / kg of air.

Several winding experiments were carried out, and with the same air gap L, the distance h. Of the funnel bunching point (transition, from the cylindrical tube to the funnel) to the spinneret surface was varied so that the relationship (h-1)

0.1 + 0. ¹ <= h 0,7.da .--

(Ξ 1 = 15 and d® = 1000). The next attempt was measured max available final tow, that is maximal odtahová speed of filaments at fiber breakage. Results are known Table 1: Table 1 h (mm) angle U. < ⁰ ) final exhaust (m / min) 240 16, S 43 190 20.9 42 140 27.4 42 90 38, S 41 70 46.0 29 40 • 61.1 0

From table 1 it can be seen that up to an angle of about 40 ⁶ can not be observed any reduction in the terminal draw-off speed, and thus no impairment zviáknovatelnosti. However, from an angle of 45 °, the maximum end draw speed decreases markedly. At an angle of about 61 °, the solution is no longer wettable.

Example 2

A spinning device corresponding to Fig. 2 was used and again the one described schematically in WO 95/04173 (number of holes 28.392, diameter of holes 100 µm, outer diameter of nozzle (outer row of holes)) was used as spinning nozzle di: 155 pm, hole-to-hole spacing (d.®: 500 pm).

The cellulose solution used contained 13.5%. cellulose and had a temperature of 120 ° C. The discharge was 0.025 g / min. The air gap L was 20 mm long. The air in the air gap had a temperature of 12 ° C and a water content of 5 g water / kg air.

The filaments were turned on a cylindrical non-rotating rod Z and pulled at an angle up from the spin bath.

At the same air gap i. The distance b was varied and analogously to Example 1 the maximum final draw-off speed and angle 5 ° were determined.

h (mm)

345

165

115 angle * (°)

..... 46

Table 2 final exhaust (m / min)

........... 4 .....

As shown in "Table 2 that does not change when úhluoť from 13 ⁰ to 34 ⁰ no reduction in the maximum delivery speed limit. However, if the angle ¢ (increased to 46 °), the end draw-off speed, i.e. the wettability, is drastically reduced. If the distance is further reduced and thus the angle α is increased, the solution can no longer be wound up).

Example 3

The same winding device was used as described in Example 2, but the air gap 1 was.

Constantly set to 30 mm.

Again, the distance b was varied. Based on the occurrence of spinning errors (tearing of the filaments, extreme bonding of the filaments together), the safety of spinning of the solution was characterized under predetermined conditions.

High spinability is given if virtually no spinning error occurs in a time interval of more than 15 minutes. If, during a time interval of minutes or before, more winding errors occur, then spinning on a technical scale is only possible with a permanent technical assistance measure.

Furthermore, spinning is characterized by a time stamp, wherein in the following Table 3,> 15 min indicates that good spinning has been given (virtually no spinning errors within 15 minutes). For example, an indication of < 10 · min means that even before 10 minutes after the start of spinning, large spinning errors have occurred which necessitate interruption of the spinning.

Table 3

h- (mm) angle οί (°) zviákňovatelnost 345 13 > 15 min 165 25 , * 1 u (B i n 115 34 > 15 min 100 ALIGN! 38 10-15 min 85 42 <10 min

It can be seen from Table 3 that up to a distance t11 of 115 mm, good spinability is given. However, if h is chosen even less, the relationship established according to the invention is no longer met, and the spinability deteriorates drastically. This is the case with both last attempts. In this case, this deterioration of the winding behavior already occurs at an angle well below 45 [deg.].

in

Example 4

In a pilot plant for the production of cellulose fibers according to the amine oxide process, the method of turning the filaments in a spin bath was also investigated in numerous individual experiments with the spinning device according to the invention.

Rotationally symmetrical rotary reversing elements of different designs (glass rod rollers having a smooth or ribbed surface) were tested. In these experiments, it was always found that, once the return element was rotated about the axial axis, the filaments of the reversing / weaving filament were wound in a short time. It is obvious that it is on or on. In the spinning bath, there is sometimes a uniform fidelity to the tearing of the fibers, which are picked up by the rotating return roller itself, are guided together from the return roller and the coiling of other filaments leads to an increasing winding. In this case, the spinning filaments are damaged, since the filaments wound on the deflection roller must be removed by mechanical intervention, which leads to a deterioration of the final product.

It has been shown that the spinning procedure must be interrupted in less than 30 minutes in order to remove the fibers wound on the spinning roller when using a rotating deflection roller.

If, while retaining the other parameters, the rotation of the return element is prevented, by virtue of the fact that it is fixed, for example, there is practically no winding. It has been shown that in this way the continuous spinning process can be maintained for more than a few hours. The use of rotatable return elements should therefore be avoided. In order to allow trouble-free operation, it is necessary that all elements are designed as non-rotatable as possible.

Claims (6)

PATENT CLAIMS A spinning apparatus for carrying out an amine oxide process according to a dry / wet spinning process - a spinnerette having spinning holes for extruding filaments, - a blower with which the extruded filaments can be cooled immediately after they have left the spinning holes, - a fluid wound bath, ./ - a bundling element which is intended to bundle the extruded filaments in the spin bath liquid, and - an air gap, which is defined as the distance of the spinneret from the surface of the spin bath liquid, - that the bundling element ( 2) located relative to the spinneret ( (3) at a distance such that the angle (<s0) produced by the filaments relative to the perpendicular to the surface (1a) i v i r t µ of the fluid for the wavelet coater is at most 45, and - that the relationship (h-1) is met 0.1 + 00, 005 1 <= 0.7. d® .------, h > wherein (d®) is the distance (mm) between the spinneret and its always adjacent spinneret on the spinneret (3), (h) is the distance (mm) of the spinner (2) from the spinneret (3), and ( 1) is an air gap, wherein 1S 0.4 mm <= d < = 2 mm, a 0 mm <1 <60mm. The spinning device according to claim 1, characterized in that (2) is designed as a return element (2), the filaments (4, 5) are not only bundled but a bundle of the forging element on which they are also turned. Spinning device according to claim 2, characterized in that the return element (2) is designed such that when the filaments are turned <4, 5) does not rotate. A spinning apparatus according to any one of claims 1 to 3, characterized in that the angle (rev) is at most 20 ^° . Spinning apparatus for carrying out the amine oxide process According to the dry / wet spinning process - a spinnerette having spinning holes for extruding the filaments, - a blower with which the extruded filaments can be cooled immediately after leaving the spinning holes, - reservoir, with spinning liquid, - a return element which is intended in the spin bath liquid to bundle and invert the extruded filaments, and - an air gap, defined as the distance of the spinneret from the liquid for the spinning bath, characterized by (2) being formed such that 5) does not rotate the device according to any one of claims 1 to 5, characterized in that the spinnerette is provided with: a nozzle body formed in a substantially rotationally symmetrical manner and having an inlet for it at its center - refrigeration _{, m} pl yn - inlet for cellulose solution, a circular spinneret with spinneret holes, and an impact plate for controlling the flow of cooling gas to the filaments which are extruded from the spinning holes, so that the flow of cooling gas extends substantially perpendicular to the filaments. 7. A spinning apparatus according to any one of claims 1 to 6, characterized in that the tank containing the spinning bath liquid is in connection with a lifting device by means of which the tank can be moved vertically back and forth to the spinning nozzle, thereby changing it. distance (1), and that the bundle element is arranged such that distance (h) remains constant despite this movement.