EP1260617A1 - Process and apparatus for the production of multifilament yarns from thermoplastic polymers - Google Patents

Abstract

Melt spun filaments(2) emerging from a nozzle plate(1) are drawn off and cooled to solidify before passing through a fiber guide(5) to be formed into multi-filament yarn(6). Tension in the filaments or the multi-filament yarn is measured after the solidification point(4) and the distance between the fiber guide and the solidification point is varied in response to the measured tension. An Independent claim is also included for the process plant which includes a drive unit(10) for adjustment of the height of the fiber guide(5) relative to the filament solidification point(4), a sensor(8) to determine filament or multi-filament yarn tension and a open or closed loop control unit(18) for controlling the drive unit according to measured tension.

Description

Method and device for producing a Multifilament yarn made from a thermoplastic polymer

The invention relates to a method for producing a multifilament yarn made of a thermoplastic polymer by the Filaments produced by melt spinning from a nozzle plate, solidified under cooling, removed and wound up, the filaments being adjustable in height after the solidification point arranged thread guide, especially to the multifilament yarn. The invention also shows an apparatus for producing a multifilament yarn made of a thermoplastic polymer, with a nozzle plate for producing filaments from a thermoplastic polymer, at least one thread guide arranged at different heights, and a device for winding up the melt spinning Multifilament yarn. The invention can be in the Production of a multifilament yarn from individual filaments or use microfilaments produced by melt spinning and especially with a thread guide to a multifilament yarn be brought together. The invention can be used anywhere use where filaments are initially molten be, the transition between the molten phase and the at least partially solid phase of the filament as a solidification point referred to as. The multifilament yarns produced can be used for technical purposes, but also for textile processing be used. Unless one or more godets can be used, the multifilament yarn with less Orientation, partial orientation, or in full stretch Condition with a high value for the uniformity of the diameter generated over the length of the filaments (Uster value) become. The invention is independent of the type of cooling. It can be used in conjunction with cross-flow cooling, internal cooling or cooling by ambient air become. With the invention filaments or microfilaments can with a fineness of less than 1 dtex per filament. at The production of a multifilament yarn can take up to 200 Filaments and more are merged.

A method and an apparatus of the one described in the introduction Kind are known from EP 0 957 187 A2. There are the Filaments by melt spinning at a spinning speed generated from 2000 to 7000 m / min. The cooling of the filaments takes place through a central blowing system, i.e. from the inside a so-called blow candle. The tempered air comes from outside fed inwards and within the bundle of filaments for Brought out. The cooling unit from which the tempered Air escapes has a cooling length that changes distance, where it is considered essential the upper end of the cooling unit from the nozzle plate to be able to. The distance depends on the titer to a maximum of 35 mm set. The filaments are held with an annular thread guide individually guided and below the cooling device summarized another thread guide. This other thread guide is arranged variable in height. This change in The height of the thread guide is based on the geometry of the blow candle set. The relative position of the solidification point remains unaffected and depends on other sizes, for example of the temperature of the polymer in the range of Nozzle plate and in particular on the take-off or production speed and the effectiveness of the cooling device. The The location of the solidification point is also many other factors, including the type of polymer Admixtures, especially colors, the titer of the filaments, the Total titer of the multifilament yarn, the desired properties of yarn and spinning speed, to get just that essential influencing factors.

The invention is based, a method and a task Device of the type described in the introduction, which is also used for carrying out the method is suitable to show with which a simple and quick adjustment in the production of different Products possible and the production more constant even textile mechanical properties of the different Products is achievable.

According to the invention, this is the case of a method as described in the introduction Art achieved in that the thread tension of the filaments or the multifilament yarn after the consolidation point measured and the distance of the thread guide to the solidification point and thus to the nozzle plate as a function of the measured one Thread tension is changed.

The invention is based on the knowledge that with a Change in the location of the solidification point of the filaments relative to the nozzle plate and relative to a thread guide too the thread tension changed, so that it is possible from a Change in thread tension inferences on the position of the Solidification point. By measuring the thread tension either the filaments before they are combined to form the multifilament yarn or the multifilament yarn after the merge a signal can be obtained from the filaments which is used for Control or regulation of the relative position of the thread guide, especially the first thread guide after the solidification point can be used. The knowledge is taken into account that in particular the textile mechanical properties of the multifilament yarn depend heavily on which one Distance between the solidification point and the first friction contact of single filaments or multifilament yarn a thread guide exists. This applies regardless of whether the Thread guide only for guidance or at the same time for preparation the filaments and / or the multifilament yarn is. The inventive method is used both during a Product change, which is usually without interruption of the Melt spinning process is carried out as well during the Manufacture and use of a specific product, in particular, the textile mechanical properties of the to keep the respective product as constant as possible. The investigation or measurement of the thread tension can be clocked, d. H. in definable or adjustable time intervals occur, also the control or regulation of the distance of the thread guide to the solidification point.

However, it is particularly advantageous if the thread tension measured continuously and the distance of the thread guide to the Solidification point depending on the measured thread tension is changed in cycles. The continuous measurement the thread tension can be recognized most quickly or immediately, if a change in textile mechanical properties entry. The cyclical control or setting of the relative distance to the solidification point leads to the fact that It also makes sense to have times when the thread guide is advantageously not moved, but stands still. A continuous up and down movement of the thread guide avoided and readjustment only takes place if this is useful to strive for constant conditions to reach.

It also makes sense if the thread tension is immediate after the first thread guide after the nozzle plate is measured.

The location of the thread tension measurement should be as close as possible the thread guide, which can be adjusted in height lie to the changes in the location of the solidification point as undisturbed as possible from others downstream Measure or determine influences. It appears even possible, the thread tension immediately before the first Measure the thread guide after the nozzle plate.

There is also the possibility that the thread tension on several places downstream of the first thread guide after the nozzle plate measured and the change in the distance of the thread guide changed after averaging the measured values becomes. The averaging can be arithmetic, but also with a weighting of the various measured values, the Signal from the sensor that is the closest distance to the solidification point is of particular importance. But it is signals from or between the arrangement are also quite possible win several godets and in the control or regulating signal for the drive of the thread guide.

When performing the procedure, it makes sense that the changes the thread tension due to the traversing during winding of the multifilament yarn by means of a large triangle be dampened in the upstream direction. Such a large installation triangle can be generated in that the traversing device upstream head thread guides a special has a large distance from the traversing device or in any case can be moved into such an operating position.

A device for making a multifilament yarn A thermoplastic polymer is characterized according to the invention in that a drive for a variable height Setting the thread guide relative to the solidification point the filaments is provided that at least one sensor for Determination of the thread tension of the filaments or the multifilament yarn is provided and that a control or regulating device for the drive depending on the determined Thread tension is provided by the sensor.

It is essential that the thread guide no longer by z. Legs To arrange the screw fastening on the device at different heights, but to provide a drive on which the thread guide is arranged and with the help of the thread guide stepless relative to the solidification point of the filaments and thus on the position of the nozzle plate in height during operation can be set variably. Such a drive leaves can be realized in a variety of ways, for example mechanical way through a motor-driven adjusting spindle, pneumatically or hydraulically through the application corresponding piston / cylinder units or the like. Furthermore, must at least one sensor is provided for determining the thread tension his. Such measuring heads with which the thread tension is determined are known per se. Such a sensor will however in the way of filaments or multifilament yarn introduced and advantageously moved together with the thread guide, so that the relative distance between thread guide and sensor does not change. Finally, a control or regulating device for the drive depending on the determined thread tension be provided by the sensor. Through this facility can be the signal delivered by the sensor or that of several Processed, processed and modulated signals delivered to the sensors Drive to be abandoned. To create a closed Control loop it is possible at the same time, even the actual one Path of the thread guide relative to the consolidation point monitor in this way one for each Product particularly favorable distance between solidification point and adjust or maintain thread guides.

The thread guide can be designed to form the multifilament yarn his. The sensor can also be used independently be arranged downstream of the thread guide. The spatial proximity of the Sensor to thread guide makes sense. It is understood by everyone Embodiments that also several thread guides adjustable in height can be provided adjustable, which is then appropriate are movable via a common drive. It makes sense but also when the thread guide and the sensor on the drive are arranged together adjustable in height. In this case only changes when the altitude changes the distance to the solidification point, but not the relative one Distance between thread guide and sensor.

There is also the possibility that the thread guide at the same time for the preparation of filaments and / or multifilament yarn is trained. It can therefore be a thread guide, that only guides the filaments. On the other hand, it can act as a thread guide that is only the multifilament yarn leads. Finally, there are also combined designs conceivable, for example, a spinning oil or other Preparation liquid is applied.

It also makes sense if the device is movable arranged head thread guide or a movable godet. This gives the opportunity to be a relatively large one Laying triangle to take during operation, so that Changes in thread tension caused by the traversing movement during Windings are generated, remain comparatively small or only damped against the direction of the multifilament yarn be given up so that they can determine the thread tension do not interfere with the sensor.

Fig. 1

eine schematische Darstellung der wesentlichen Elemente zur Herstellung eines Multifilament-Garns in einer ersten Ausführungsform,

Fig. 2

eine schematische Darstellung der wesentlichen Elemente zur Herstellung eines Multifilament-Garns in einer zweiten Ausführungsform,

Fig. 3

eine schematische Darstellung der wesentlichen Elemente zur Herstellung eines Multifilament-Garns in einer dritten Ausführungsform, und

Fig. 4

eine schematische Darstellung der wesentlichen Elemente zur Herstellung eines Multifilament-Garns in einer vierten Ausführungsform.

The invention is explained schematically using various exemplary embodiments. Show it:

Fig. 1

1 shows a schematic illustration of the essential elements for producing a multifilament yarn in a first embodiment,

Fig. 2

1 shows a schematic illustration of the essential elements for producing a multifilament yarn in a second embodiment,

Fig. 3

a schematic representation of the essential elements for the production of a multifilament yarn in a third embodiment, and

Fig. 4

is a schematic representation of the essential elements for producing a multifilament yarn in a fourth embodiment.

In Fig. 1, a nozzle plate 1 is highly schematic Spinning line illustrates from a variety of filaments 2 come out at a distance from each other in the liquid state. It can are a bundle of about 200 to 400 filaments. The emerging liquid or doughy filaments are on cooled down in some way. This is cross-flow cooling 3 schematically indicated, with the cool air from the outside through the Bundle of filaments 2 is blown. During the downward movement the filament 2 occurs at least a partial solidification in the Surface area. A solidification point 4 run through, for all filaments 2 at least approximately the same Distance from the nozzle plate 1 is formed. The single ones Filaments 2 become one with the help of a thread guide 5 Multifilament yarn 6 summarized, which is according to arrow 7 is moved downwards or is pulled in this direction. This creates a thread tension in the multifilament yarn 6. A sensor 8 is provided for measuring the thread tension. The withdrawn multifilament yarn 6 then runs through another thread guide 9, which is below or downstream of the sensor 8 is provided. The two thread guides 5 and 9 are common Provided variable in height, while the sensor 8 is stationary is arranged. For moving the thread guides 5 and 9 in the A drive 10 is provided at the height. The drive 10 has one Motor 11 on, over the two threaded spindles 12 and 13 rotated become. On a rising nut of the threaded spindle 12 is the Thread guide 5 attached so that when the motor rotates 11 or the threaded spindle 12 according to the double arrow 14 in height can be moved variably. Accordingly, the thread guide 9, which is coupled to the threaded spindle 13, according to Double arrow 15 changed in height. With this height mobility it is a matter of changing a distance 16 between the consolidation point 4 and the thread guide 5. The Screws 12 and 13 can also have different pitches have to adjust to the relative setting of the thread guide 5 and 9 to influence each other. Essentially comes but it on the adjustment of the distance 16 between the Solidification point 4 and the filaments 2 and a starting position of the thread guide 5.

If the thread tension of the multifilament yarn measured by sensor 8 6 changes, a change signal is formed, which via a line 17 to a control and regulating device 18 is given. There the signal can be processed modulated or otherwise processed. About the tax and Control device 18, the motor 11 is then activated in order to Requires the relative height of the thread guide 5 to the consolidation point 4 to change.

The multifilament yarn 6 runs through the second thread guide 9 in a first godet 19 and a second Galette 20, in which it is treated in the usual way, for example is stretched. Each godet 19, 20 has two roles. In addition, there is a vertically movable one below last roller 21 is provided, which is arranged on a carriage 22 is arranged and movable with this up and down is. To reach a change position, the roller 21 moved down, you are in the operating position comparatively above, so that a relatively large installation triangle 23 between the roller 21 and a traversing device 24 is formed. The multifilament yarn 6 is finally with With the help of a winder 25 with motor 26 wound into a coil. The laying triangle 23 is chosen to be as large as possible, thus from the traversing movement of the multifilament yarn 6 one minimal change in thread tension results and thus this thread tension change the determination of the thread tension influenced as little as possible by means of the sensor 8.

In principle, the device indicated in FIG. 2 agrees with the 1 over a wide range. At the Nozzle plate 1, however, is a blow candle 27 stationary attached. The blow candle 27 has a tube with openings which cooling air radially from the inside out through the bundle the filaments 2 flows. At the fixed end of the blow candle 27 there is a thread guide 28 on which the solidified Filaments 2 are guided. The thread guide 28 can serve as a preparation thread guide be trained. His distance from that Solidification point 4 cannot be set actively because the Blow candle 27 and thus the thread guide 28 are stationary.

Here, too, the filaments 2 are brought together on a thread guide 5. The thread guide 5 is here also with the drive 10 or the joint spindle 12 connected in a variable height. Right away The sensor 8 is located below the thread guide 5 Determination of the thread tension. This sensor 8 is also here movably arranged, d. H. coupled to the drive 10. The The distance between thread guide 5 and sensor 8 remains expedient constant. Here too, the thread guide 5 is changed the distance 16 to the solidification point 4 tracked. in the Run of the multifilament yarn 6 is a fixed thread guide 29 and subsequently another, but arranged in a fixed position Sensor 30 provided. A line 17 leads from the sensor 8 of the control and regulating device 18. From the sensor 30 leads a line 31 to the control and regulating device 18. Further Fixed sensors 32 and 33 are located in the area the godets 19, 20, 21 and themselves via lines 34 and 35 also connected to the control and regulating device 18. Another stationary sensor is arranged downstream of the roller 21 36 provided that via a line 37 to the control and Control device 18 is connected. That way the thread tension signals detected by the sensors 8, 30, 32, 33 and 36 processed in the control and regulating device 18 and a corresponding control or regulating signal on the Motor 11 of the drive 10 given, so that when determined Changes in thread tension change the height position the thread guide 5 and the sensor 8. The Distance 16 to solidification point 4 adjusted, adjusted or set. The location of the solidification point 4 can be changing production conditions also change. The downstream winder 25 is here with a pressure roller 38 fitted. In the control and regulating device 18, the incoming signals, preferably filtered and weighted, evaluated and the motor 11 controlled accordingly. The Detection of the thread tension can be continuous and the Readjustment of the height of the thread guide 5 and the sensor 8 cyclically or step by step.

In the embodiment according to FIG. 3, the blow candle 27 is not Arranged stationary on the nozzle plate 1, but sits variable in height on the threaded spindle 12. The lower end of the Blow candle 27 is also provided with a thread guide 39, whose distance varies in height from the solidification point 4 is controllable. A first sensor 8 and a second sensor 30 are fixed here. The thread guides 5 and 9 arranged in a fixed position. Otherwise the device is largely correct corresponds to the embodiment of FIG. 2. Instead of A blow candle 27 with a fixed effective length can also a blow candle 27 is provided with a variable effective length be, the upper end of which is connected to the nozzle plate.

In the embodiment of the device according to FIG. 4, this is Bundle of filaments 2 from a ring-shaped cooling device 40 enclosed, with the cooling air radially from the outside is blown inwards through the bundle of filaments 2. In Relation to the solidification point 4 becomes the thread guide 5 performed, the height 10 adjusted via the drive can be. The drive 10 has at least one here Piston / cylinder unit 41, with which the thread guide 5 is adjustable in height can be moved. From a fixed sensor 8 a corresponding signal of the thread tension reaches the Control and regulating device 18. This device is missing the godets. Instead, it is in a straight line from the top to the top a head thread guide 42 is provided below, which is from the carriage 22 is worn and in this respect for enlargement or reduction of the triangle 23 is vertically movable. A winder 25 and a traversing device 24 complete this Investment. A control or regulation signal is from the control and Control device 18 via a line 43 to the piston / cylinder unit 41 modulated. The thread guide 5 can also be used here Preparation thread guide to be trained.

LIST OF REFERENCE NUMBERS

1 -

nozzle plate

2 -

filament

3 -

Cross-flow cooling

4 -

solidifying point

5 -

thread guides

6 -

Multifilament yarn

7 -

arrow

8th -

sensor

9 -

thread guides

10 -

drive

11 -

engine

12 -

screw

13 -

screw

14 -

double arrow

15 -

double arrow

16 -

distance

17 -

management

18 -

Control and regulating device

19 -

Galette

20 -

Galette

21 -

role

22 -

carriage

23 -

laying triangle

24 -

Traversing device

25 -

winders

26 -

engine

27 -

blow candle

28 -

thread guides

29 -

thread guides

30 -

sensor

31 -

management

32 -

sensor

33 -

sensor

34 -

management

35 -

management

36 -

sensor

37 -

management

38 -

pressure roller

39 -

thread guides

40 -

cooling device

41 -

Piston / cylinder unit

42 -

Yarn guide

43 -

management

Claims (10)

Process for producing a multifilament yarn from a thermoplastic polymer by producing the filaments by melt spinning from a nozzle plate, solidifying them under cooling, pulling them off and winding them up, the filaments being guided in a thread guide arranged at different heights after the solidification point, in particular to the multifilament yarn are brought together, characterized in that the thread tension of the filaments or multifilament yarn is measured after the solidification point and the distance of the thread guide to the solidification point and thus to the nozzle plate is changed as a function of the measured thread tension. A method according to claim 1, characterized in that the thread tension is measured continuously and the distance of the thread guide to the consolidation point is changed in cycles depending on the measured thread tension. Method according to claim 1 or 2, characterized in that the thread tension is measured immediately after the first thread guide after the nozzle plate. Method according to claim 1, characterized in that the thread tension is measured at several points downstream of the first thread guide after the nozzle plate and the change in the distance of the thread guide is changed after averaging of the measured values. Method according to Claim 1, characterized in that the changes in the thread tension are damped in the upstream direction by means of a traversing during winding of the multifilament yarn by means of a large laying triangle. Device for producing a multifilament yarn (6) from a thermoplastic polymer, with a nozzle plate (1) for producing filaments (2) from a thermoplastic polymer, at least one thread guide arranged at different heights, and a device for winding up the multifilament produced by melt spinning Yarn, characterized in that a drive (10) for adjusting the height of the thread guide (5; 5, 9; 39) relative to the solidification point (4) of the filaments (2) is provided, that at least one sensor (8) for determining the thread tension of the filaments (2) or the multifilament yarn (6) is provided and that a control or regulating device (18) for the drive (10) is provided as a function of the determined thread tension by the sensor (8). Apparatus according to claim 6, characterized in that . the thread guide (5) is designed to form the multifilament yarn (6) and the sensor (8) is arranged immediately downstream of the thread guide (5). Apparatus according to claim 6 or 7, characterized in that the thread guide (5) and the sensor (8) are arranged to be adjustable in height together via the drive (10). Device according to one or more of claims 6 to 8, characterized in that the thread guide (5; 39) is at the same time designed for the preparation of the filaments (2) and / or the multifilament yarn (6). Device according to one or more of claims 6 to 9, characterized in that the device has a movably arranged head thread guide (42) or a movable godet (21).

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