EP1607500B1 - Texturing device with disentangling stretching and braking - Google Patents

Description

The present invention relates to a device for increasing and regulating the thread tension, in particular a Entwirrstreckenbremse, on a Texturierspinnvorrichtung with at least one texturing device according to the preamble of claim 1.

State of the art

For BCF machines, air nozzles are predominantly used to texturize the yarn. In this case, the thread is drawn by means of an injector in the texturing, further heated by a heated propellant gas and then formed into a Garnpfropfen. The hot Garnpfropfen is deposited on a rotating screen drum. By means of a negative pressure applied inside the screening drum, which is used predominantly for cooling, and therefore also called the cooling drum, ambient air flows through the plug lying on the screen and cools it. By cooling to a sufficiently low temperature, the crimping produced in the grafting is fixed in the thread. The plug is then stretched out again into a yarn and guided by means of conveyor rollers to further treatment points on the machine.

There are two criteria that should be taken into account. The temperature of the plug when stretching must be below a certain value dependent on the polymer. If the plug is stretched out at too high a temperature, the thread immediately loses part of the curl again. One therefore tries to choose the cooling angle and thus the residence time of the plug on the screen drum as large as possible. The yarn, which has been pulled out again to form a thread, slides over a sliding angle on the sieve drum. In this case, a certain thread train is generated by friction on the screen. If one chooses the first angle, the cooling angle, as large as possible, the second angle, the slip angle, inevitably decreases.

For the reasons listed above, the threading after the screening drum is usually too low for a stable run on the subsequent conveyor rollers. At today In the prior art, the thread tension after the screening drum is correspondingly increased by the insertion of a thread brake. The thread brake is usually friction brakes. The term "Entwirrstreckenbremse" is a device to understand that tenses the drawn-out thread after dissolution of the plug for further processing.

Known friction brakes are for example from the publications DE 100 09 611 A1 and DE 195 44 202 A1 and the prior art cited therein. The principle of operation of the known thread brakes is based on the fact that the thread experiences a friction with thread guide elements. Known thread brakes can be controlled by adjustable thread guide elements.

A generic device is also off GB 1381 937 or DE 22 00 064 known.

Disadvantages of the prior art

At high yarn speeds, the yarn is again heated inadmissible at the friction points and can lose part of the crimp.

From the EP 0 488 939 A1 For example, a method and apparatus for graft resolution after texturing is known. In this prior art, a sufficient braking effect can not be generated. Another disadvantage is that an exact adjustment of the separation point of a screening drum is required, which does not lead to reproducible results in terms of control of the thread tension.

Object of the invention

The object of the invention is to provide a device and a method with which the mentioned disadvantage is avoided, the thread train after the texturing device, in particular after the cooling drum, as gently as possible and without mechanical friction points can be increased and controlled and the cooling of the thread is improved ,

Solution of the task

The object is achieved by a device with the features of claim 1 and a method according to claim 18. Further advantageous embodiments of the invention are defined in the subclaims.

The essence of the invention is that the thread is not braked by a friction with thread guide elements and thus placed in a tension, but by friction with a gaseous and / or fluid medium surrounding the thread. The medium may be a gas, eg air, a gas mixed with an aerosol, for example finely divided water vapor, a vapor or a liquid. It is essential that one of the texturing device 4 downstream thread running path 26 is present, on which the thread 7 at least once on a free thread length 24 of 0.5 m - 10 m, preferably 1 m to 5 m, in particular 2 m to 5 m, the Friction is exposed to a gaseous and / or fluid medium, wherein before the free thread length 24 of the thread is not braked by friction on thread guide elements. In other words, the free thread running path, over which the thread is not acted upon or deflected by any mechanical elements, connects directly to the texturing device 4 or its screening drum 6, without the thread having contact with such elements.

To ensure sufficient frictional force, the thread must be guided within the thread running distance, in which the braking takes place, on a free thread length of at least 0.5 m. Free thread length is to be understood as a length at which the thread does not come into contact with a thread guiding element. This length can be up to 10 meters long.

The thread running path has at least the length of a free thread length. On the thread running line, the thread can be guided back and forth several times and thus repeatedly pass through the corresponding free thread length.

Preferably, the thread is guided on the yarn path over at least two pulleys whose distance determines the free thread length.

The thread sets on the free thread length, the surrounding medium, such as air, in a movement. This train can act on parallel guided by pulleys more free thread lengths of the thread and thus increase the friction. Any resulting frictional heat is dissipated by the surrounding medium immediately, and it can not come to a friction-induced heating of the thread.

In a preferred embodiment of the invention, means are provided which set the gaseous and / or fluid medium along the free thread length in a directed movement, preferably against or transverse to the thread running direction. By an externally driven movement of the medium surrounding the thread, an additional braking effect on the thread can be achieved. In addition, it is possible to exchange the medium by the movement and add cooled medium, which increases the cooling effect. The means which set the medium in motion may be, for example, a fan, a pump, a supply of the medium in the vicinity of the free thread length or a removal possibility of the medium.

For a supply of media with different properties from the ambient air, it is advantageous to encapsulate the yarn path through a chamber. The medium can be brought so targeted in the vicinity of at least one free thread length.

The chamber is to be designed so that the thread can be passed conveniently and the gaseous and / or fluid medium can be brought into motion within the chamber. For this purpose, the chamber preferably has a movable lid, which serves to insert the thread, the chamber is advantageously provided with openings for the entry or exit of the thread, the chamber preferably has openings for a supply and a discharge of the gaseous and / or fluid medium.

As an alternative to or in addition to a chamber, it may be provided that the thread runs on one or more sections of the free thread length within one or more tubular elements. The tubular elements serve to guide, in particular, when the thread is not in the running state or the thread is weakening due to other reasons. In the running state of the thread usually does not touch the tubular elements.

Advantageously, the at least one tubular element is provided with a preferably closable longitudinal slot for insertion of the thread, and one or more supply channels for the supply of the gaseous and / or fluid medium.

The effectiveness of the device according to the invention can be further improved if it comprises a control device, with which the thread train to be achieved can be regulated. By the control device, for example, the free thread length can be varied, but it can also be the speed of the directed movement, the composition, the amount or the temperature of the gaseous and / or fluid medium can be regulated.

In a preferred embodiment, the control device comprises a control loop, which ensures a constant value of the thread train. For this purpose, the control device has a device for detecting the thread train.

Further advantageous embodiments will become apparent from the following description and the claims.

drawings

Figur 1

eine schematische Darstellung einer Ausführung der Entwirrstreckenbremse gemäß dem Stand der Technik;

Figur 2

eine schematische Darstellung eines erstes Ausführungsbeispiels einer erfindungsgemässen Entwirrstreckenbremse;

Figur 3

eine schematische Darstellung eines weiteren Ausführungsbeispiels einer erfindungsgemässen Entwirrstreckenbremse mit forcierter Kühlung;

Figur 4

eine schematische Darstellung eines weiteren Ausführungsbeispiels einer erfindungsgemässen Entwirrstreckenbremse mit einer pneumatischer Bremsung des Fadens;

Figur 5

eine schematische Darstellung eines weiteren Ausführungsbeispiels einer erfindungsgemässen Entwirrstreckenbremse mit pneumatischer Bremsung des Fadens und Regelung der Fadenzugkraft.

Show it:

FIG. 1

a schematic representation of an embodiment of the Entwirrstreckenbremse according to the prior art;

FIG. 2

a schematic representation of a first embodiment of an inventive Entwirrstreckenbremse;

FIG. 3

a schematic representation of another embodiment of an inventive Entwirrstreckenbremse with forced cooling;

FIG. 4

a schematic representation of another embodiment of an inventive Entwirrstreckenbremse with a pneumatic braking of the thread;

FIG. 5

a schematic representation of another embodiment of an inventive Entwirrstreckenbremse with pneumatic braking of the thread and control of the thread tension.

Description of the embodiments

FIG. 1 shows a section of a texturing spinning device 1 according to the prior art. The yarn 7 to be processed is first stretched over a pair of draw rolls 2 and then fed into a texturing device 4. There arises a plug 5, which is placed on a rotating screen drum 6 after leaving the texturing device 4. It remains above the cooling angle K on the screen drum 6. After passing through the cooling angle K, the plug at the end A of the cooling angle K is pulled out again to a thread 7. The extended thread 7 then slides within the angle R on the screen drum 6. The friction between the thread 7 and the screen drum 6 generates a thread train, so that the thread 7 leaves the screen drum 6 with the corresponding thread train. As already mentioned, this string is usually too deep for the next, not shown in the figure, process stages. It is therefore increased by means of a yarn brake 3. The thread brake 3 comprises a plurality of thread guide elements E, at which the thread 7 experiences a friction. When entering the next process stage, the yarn 7 has a yarn tension of a higher value than before the yarn brake.

With increasing process speeds, the size of the angle R and the associated rubbing action on the yarn 7 has a negative impact on yarn quality, e.g. increases with increasing angle R the number of filament breaks. This problem is exacerbated by the trend towards yarns with a finer single filament denier.

FIG. 2 shows by way of example a first embodiment of the invention. After leaving the screening drum 6, the thread 7 is guided over an inventive Entwirrstreckenbremse 23. This consists of a yarn path 26, on which the thread over guide rollers 10 and 11 is guided, so that the yarn. 7 three times a free thread length 24 passes, which corresponds approximately to the distance 27 of the guide rollers 10 and 11. The resulting above all at high yarn speeds air friction is sufficient to achieve the desired thread train after the Entwirrstreckenbremse 23. The thread guide 9 only serves to determine the position of the thread at the inlet point on the subsequent conveyor roller 8.

The length of the thread running path 26 and thus the free thread length 24 is adjusted to the thread speed and the desired thread tension. It can be between 0.5 m and 10 m, preferably between 1 m and 5 m. In contrast to the yarn brake according to the prior art, the yarn 7 is further cooled on the inventive Entwirrstreckenbremse 23 and not reheated by the mechanically generated frictional heat to the yarn brake. The aerodynamically generated braking effect is very gentle on the thread and is not influenced by the contamination and / or the wear of thread-contacting surfaces as in the thread brake according to the prior art. The braking effect therefore remains stable and does not change over time.

The laying of the thread in a device according to the invention is very simple, there must be no tight thread guide elements are passed with a landing gun.

FIG. 3 shows a schematic representation of another embodiment of an inventive Entwirrstreckenbremse 23 with forced cooling. All or part of the yarn path 26 is placed in a chamber 12. This chamber 12 has a movable lid, not shown in the figure, on the front side, which can be opened for insertion of the thread 7. The chamber 12 is also provided with openings 19 for the entry or exit of the thread 7. Furthermore, the chamber 12 has openings 13 for the supply and openings 14 for the discharge of a gaseous and / or fluid medium. As a medium z. B. cooled air can be used. The thread 7 is still cooled by this medium in addition to the braking effect. This can be advantageous for polymers with a low glass transition temperature, such as

Polypropylene. Another advantage of using a cooled or cooling medium is that one can eliminate the influence of room temperature on the final temperature of the filament 7 after texturing. It is thus possible to achieve a more constant yarn quality even in the case of an insufficiently or insufficiently conditioned environment around the machine.

A gaseous medium may be aerosolized, e.g. Water mist, to be enriched.

FIG. 4 shows a schematic representation of another embodiment of an inventive Entwirrstreckenbremse 23 with a pneumatic braking of the thread. On the yarn path 26, which is downstream of the screen drum 6, the thread 7 is guided on one or more sections of the free thread length 24 by tubular elements 15. in the FIG. 4 For example, only one element 15 is shown, but it is easy to understand that when guiding the thread as in FIG. 2 and 3 shown, several elements 15 can be used. The elements 15 are provided with a lockable longitudinal slot not shown in the figure for inserting the thread 7. They have one or more supply channels 16 for the supply of a gaseous and / or fluid medium, hereinafter referred to as fluid. The arrangement of these supply channels 16 is selected so that they produce an injector effect and thus a flow in the longitudinal direction through the element 15 by means of the supplied fluid. It is also possible to attach two or more injectors 17 over the lands of the element 15. Exemplary is in FIG. 4 a second arrangement of injectors 17 is shown. By means of these injectors 17, a high, easily influenced flow velocity of the fluid in the longitudinal direction, counter to the thread running direction 25, can be generated by the elements 15.

FIG. 5 shows a schematic representation of another embodiment of an inventive Entwirrstreckenbremse 23 with pneumatic braking of the thread 7 and control of the thread tension. With the measure of the flow velocity of the fluid in the elements 15, the braking effect on the thread 7 can be easily Taxes. The amount of fluid supplied at 16 and 17, respectively, is changed by a controller 21 in this case.

It is also readily conceivable to use these means for controlling the fluid velocity and thus the braking effect in the elements 15 to build up a control loop with which the thread tension can be kept constant, for example. A sensor 18 detects the thread tension before entering the next treatment stage, in other words a measure of the longitudinal force in the thread 7. The measured thread tension is compared in a controller 20 with the desired value 22. If the thread tension deviates from the predetermined value, the controller 20 delivers a corresponding signal to the control device 21, which in turn changes the quantity of fluid supplied to the element 15 such that the thread train again assumes the predetermined value.

Claims (21)

1. A device for increasing and regulating filament tension, in particular a braking device (23) for disentangling the filament at a texturing spinning device comprising at least one texturing device (4) that preferably comprises a screen drum (6), wherein a filament traveling path (26), along which the filament is not deflected or guided by any mechanical elements, directly adjoins the texturing device (4) or the screen drum (6) thereof, without the filament being in contact with such elements,
   characterized in that
   within the filament traveling path (26), in which braking occurs, the filament is guided at least once over a free filament length (24) of at least 0.5 m and is subjected to friction with a gaseous and/or fluid medium.
2. The device of claim 1, characterized in that the free filament length (24) is from 0.5 m - 10 m, preferably 1 m to 5 m, in particular 2 m to 5 m.
3. The device of claim 1 or 2, characterized in that the filament traveling path (26) is provided downstream of the texturing device (4), along which path the filament (7) is subjected to friction with a gaseous and/or fluid medium several times along the free filament length (24) of from 0.5 m - 10 m, preferably 1 m to 5 m, in particular 2 m to 5 m, wherein, upstream of the free filament length (24), the filament is not braked by friction with filament guiding elements.
4. The device of at least of one of the preceding claims, characterized in that means are provided which impart a directed movement to the gaseous and/or fluid medium along the free filament length (24), preferably in a direction opposite to transverse to filament traveling direction (25).
5. The device of at least of one of the preceding claims, characterized in that the free filament length (24) is between 1 m and 5 m.
6. The device of at least of one of the preceding claims, characterized in that at least two guide rollers (10, 11) are provided along the filament traveling path (26), the distance (27) between the rollers defining the free filament length (24).
7. The device of at least of one of the preceding claims, characterized in that the filament traveling path (26) is enclosed in a chamber (12).
8. The device of at least of one of the preceding claims, characterized in that the chamber (12) has a movable cover serving to insert the filament.
9. The device of at least one of claims 7 or 8, characterized in that the chamber (12) is provided with openings (19) for filament (7) to enter and to exit.
10. The device of at least one of claims 7 to 9, characterized in that the chamber (12) has openings (13, 14) for the supply and the discharge of the gaseous and/or fluid medium.
11. The device of at least of one of the preceding claims, characterized in that at least one tubular element (15) is provided along the filament traveling path (26) to guide the filament (7) along at least a portion of the free filament length (24).
12. The device of the preceding claim, characterized in that the at least one tubular element (15) is provided with a longitudinal slot for the insertion of the filament (7), the slot preferably being closable.
13. The device of at least one of claims 11 or 12, characterized in that the at least one tubular element (15) has one or a plurality of supply channels (16, 17) for the supply of gaseous and/or fluid medium.
14. The device of at least of one of the preceding claims, characterized in that the gaseous and/or fluid medium contains an aerosol, in particular water spray, to increase the cooling effect.
15. The device of at least of one of the preceding claims, characterized in that the device includes a control device (21) by means of which the filament tension to be achieved can be regulated.
16. The device of at least of one of the preceding claims, characterized in that the device includes a control device (21) by means of which the speed of the directed movement of the gaseous and/or fluid medium can be regulated.
17. The device of at least one of claims 15 or 16, characterized in that the control means (21) includes a control circuit ensuring a constant value of filament tension.
18. A method for increasing and regulating the filament tension, in particular by means of a braking device (23) for disentangling the filament, wherein a filament is guided through at least one texturing device (4) of a texturing spinning device, preferably via a screen drum (6), wherein after exiting from the actual texturing device (4), preferably after traveling off a screen drum (6), the filament runs through at least one free filament traveling path immediately downstream of the texturing device (4) or the screen drum (6) thereof and without contact with mechanical elements, the filament not being acted upon or guided by such elements along the free filament traveling path,
    characterized in that
    within the filament traveling path (26), in which a braking occurs, the filament is guided at least once over a free filament length (24) of at least 0.5 m and is subjected to friction with a gaseous and/or fluid medium.
19. The method of claim 18, characterized in that within the texturing device (4) of the texturing spinning device (1), the filament travels through a downstream filament traveling path (26) in which the filament (7) is subjected to friction with a gaseous and/or fluid medium once or several times along a free filament length (24) of 0.5 m - 10 m, preferably 1 m to 5 m, in particular 2 m to 5 m.
20. The method of one of the preceding method claims, characterized in that in an additional method step, a directed movement is imparted to the gaseous and/or fluid medium along the free filament length (24), preferably opposite or transverse to the filament traveling direction (25).
21. The method of one of the preceding claims, characterized in that in an additional method step, the speed of the directed movement of the gaseous and/or fluid medium, and thus the filament tension, is regulated by means of a control means (21).

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