EP1318219A2 - Method and apparatus for spinning stable textile fibres using Spinnrotors - Google Patents

Abstract

In a spinning process fibre runs at high-speed through a rotor housing maintained at low pressure and closed by a cap. The incoming staple fibres collect within the rotor groove, combine and twist in the binding-in-zone, and discharge as a yarn section (44) extending between the rotor groove and thread withdrawal jet. The yarn section is subject esp. to a pneumatic force (F) opposite to its direction of rotation (U). <??>The curved yarn section (44) is exposed to numerous surrounding array of tangential incoming air jets applying a twist force at an angle of between 10 and 30 to the yarn section (44). The yarn section (44) rotates at a distance of 0.5 to 1.5 mm from the surrounding air jets. Also claimed is a commensurate open-end spinning assembly.

Description

The invention relates to a method for spinning textiles Staple fibers according to the preamble of claim 1 and one Device for performing the method according to claim 6.

As known and described in numerous patents, open-ended rotor spinning, individual fibers are separated by a so-called opening roller combed out of a sliver were, via a fiber guide channel on the fiber slide surface of a spinning rotor rotating at high speed. The single fibers under the influence of centrifugal force are pressed against the rotor wall, slide over the Fiber slide surface into the rotor groove, where it is duplicated form a fiber ring.

This fiber ring is one by one through the thread end Thread take-off nozzle broken open thread and the in the area of a so-called integration zone under the Influence of rotor rotation forming new thread over the Thread take-off nozzle drawn off at a constant speed.

This means that during the production of a spun thread, a thread leg is formed between the so-called binding zone and the thread take-off nozzle and rotates in the direction of rotation of the rotor at approximately the rotor speed.
The yarn leg has a thread pulling force that decreases with increasing rotor radius. In order to make sure that the thread in the binding zone already has so much strength, that is to say twist, that it does not tear off when it is drawn off, additional false wire is placed on the thread, preferably via the thread withdrawal nozzle.

The size of the false wire must, however, be dosed precisely, since if the false wire is too high there is a risk that the thread will be overturned in the area of the binding zone.
In addition, a high false wire increases the risk of spinning wrapping fibers with a low pitch angle up to abdominal bandages without a pitch.

In the case of open-end rotor spinning devices which are customary today, the yarn leg has a largely linear course in the region of the rotor groove during its rotation between the thread take-off nozzle and the binding zone.
The twine leg only bends relatively sharply in the direction of rotor rotation at the so-called separation point, which is immediately in front of the binding zone.
This means that the radius of curvature in the area of the deflection point is relatively small.
However, such a small radius of curvature has the disadvantage that it at least severely hinders the spreading of the false wire introduced via the thread draw-off nozzle into the binding zone.

Various attempts have been made to to influence the geometry of the yarn leg, in particular around the radius of curvature in the area of the deflection point enlarge.

From JP-AS 46-33 740, for example, an open-end spinning device is known which has a relatively large-area thread draw-off nozzle. In this known spinning device, the yarn leg slides on the surface of the yarn withdrawal nozzle during the yarn take-off and is thereby braked mechanically, which leads to a bulging of the yarn leg against its direction of rotation.
With this bulge, the critical radius of curvature of the yarn leg in the area of the deflection point can be mitigated, but it is disadvantageous with such a device that, due to the large-area support of the thread on the surface of the thread take-off nozzle, a very high false wire is placed on the yarn leg, with which already highly negative consequences described above.

A comparable spinning device, in which the yarn leg is mechanically acted on, is also described on page 10 of the magazine "Textilbetrieb" (edition: November 1976).
The OE rotor spinning device described in this article has a rotatably mounted spinning chamber with a flat spinning chamber base and a friction disk that can be rotated in the opposite direction.
Between these two friction elements, the fiber material fed rotates.

Furthermore, an old open-end spinning process is described in AT-PS 268 942, in which, among other things, the geometry of the yarn leg is to be influenced by appropriate adjustment of the thread tension.
The known method is, however, rotor spinning machines High who work for today with rotor speeds of well over 100,000 min ^-1, hardly suitable and could not prevail in practice.

Based on the aforementioned prior art, the Invention based on the object, a method and a Develop device through which, among other things, a Quality improvement of yarns, for example through Reduction in the proportion of wrapping fibers can be achieved can.

According to the invention, this object is achieved by a method as described in claim 1, or by a device according to claim 6.

Advantageous embodiments of the method according to the invention are the subject of subclaims 2 to 5.
Preferred developments of the device according to the invention are described in claims 7 to 12.

The method according to the invention, that is to say the pneumatic bulging of a twine leg rotating at high speed in the opposite direction of its rotation has the particular advantage that the figuration of the twine leg in the area in front of the so-called separation point could be sustainably improved by increasing the radius of curvature in the sense of better initiation of rotation, without increasing the risk that the yarn receives additional lower thirds.
In addition, the bulging of the yarn leg means that the yarn in the area of the rotor groove, that is to say in the binding zone, has a higher yarn tensile force, which has a positive effect on the yarn formation.

As stated in claim 2, is in advantageous training provided that a pneumatic force that comes from a variety of Individual air flows exist. By dividing the pneumatic force in a variety of individual air flows is an even and gentle treatment of the rotating thread leg guaranteed.

In a preferred embodiment, the individual air flows emerge from the swirl air bores of a so-called swirl ring, as described in claim 3.
The swirl ring is arranged in the area of the thread take-off nozzle and completely surrounds it.
Since the swirl air bores are connected to one another via a so-called ring channel, it is ensured that all individual air flows always have an almost equal strength. The strength of the individual air streams can also be adjustable if required.

The swirl air bores of the swirl ring are advantageously arranged in such a way that the individual air streams act on the rotating yarn leg at a predetermined, optimal righting angle α.
It has been found to be particularly advantageous if the righting angle α of the individual air streams, based on the plane of rotation of the yarn leg, is between 10 ° and 30 ° (claim 4).

Furthermore, it was found that ideal geometrical relationships exist when the distance a of the rotating yarn leg from the mouths of the swirl air bores is between 0.5 and 1.5 mm, as set out in claim 5.
At such a distance a, not only is there sufficient arching of the yarn leg during its rotation, but also effective use of the amount of air used is ensured.

As set out in claim 6, the device according to the invention is characterized in that a fiber duct plate closing the rotor housing is present and in that a plurality of swirl air bores are arranged in the region of the fiber duct plate and surround the thread take-off nozzle in a ring shape.
Such a design has the particular advantage that the swirl air bores are positioned close to the thread take-off nozzle and thus approximately half the length of the yarn leg.
Pneumatic loading of the yarn leg in this area leads to a sufficiently large bulge of the yarn leg even with small amounts of air and thus to an increased introduction of yarn twists into the binding zone.

As set out in claims 8 to 10, the mouths of the swirl air bores are directed both against the direction of rotation of the yarn leg and with respect to the plane of rotation of the yarn leg at an erection angle α which is between 10 ° and 30 °.
About 20 to 40 swirl air bores are preferably provided per swirl ring, each having a diameter between 0.2 and 1.0 mm.
Such an advantageous embodiment of a swirl ring ensures, on the one hand, an undisturbed rotation of a bulging yarn leg, and on the other hand, the additionally required energy input is minimal.

As described in claim 11, the swirl air bores are supplied with compressed air, preferably via a separate compressed air source.
This means that the ring channel connecting the swirl air bores is connected to a separate compressed air source via a pneumatic line.
Such a compressed air source then simultaneously supplies all of the swirl rings of the open-end spinning machine with the necessary pneumatic energy.

In an alternative embodiment, however, it can also be provided that the swirl air bores are connected to the atmosphere on the inlet side (claim 12).
In this case, the negative pressure prevailing within the rotor housing in the area of the swirl air bores generates individual air flows which bulge the rotating yarn leg against its direction of rotation.

As stated in claim 7, the swirl air bores each form a swirl ring which surrounds a thread take-off nozzle arranged in an exchangeable duct plate adapter.
Such training has the advantage, for example, that if necessary, the swirl ring can also be exchanged by simply replacing the channel plate adapter, and thus the influence of the pneumatic energy on the rotating yarn leg can be adapted according to the given yarn parameters and, if necessary, easily changed.

Further details of the invention are as follows exemplary embodiment explained with reference to the drawings removable.

Fig. 1

schematisch und in Seitenansicht eine OffenendRotorspinnvorrichtung mit der erfindungsgemäßen Vorrichtung zum Auswölben eines Garnschenkels,

Fig. 2

in einem größeren Maßstab, einen in einem Rotorgehäuse angeordneten Spinnrotor, wobei das Rotorgehäuse durch eine Faserkanalplatte abgedeckt ist, deren Kanalplattenadapter einen erfindungsgemäßen Drallkranz aufweist,

Fig. 3

den in den Spinnrotor reichenden Kanalplattenadapter mit Drallkranz in einem größeren Maßstab, im Schnitt,

Fig. 4

eine Draufsicht des am Kanalplattenadapter angeordneten Drallkranzes,

Fig. 5

eine Prinzipskizze des erfindungsgemäßen Verfahrens,

Fig. 6

eine Prinzipskizze des bislang üblichen, den Stand der Technik darstellenden Verfahrens,

Fig. 7

eine Seitenansicht des Drallkranzes gemäß Schnitt VII-VII der Fig.4.

It shows:

Fig. 1

schematically and in side view an open-end rotor spinning device with the device according to the invention for arching a yarn leg,

Fig. 2

on a larger scale, a spinning rotor arranged in a rotor housing, the rotor housing being covered by a fiber channel plate, the channel plate adapter of which has a swirl ring according to the invention,

Fig. 3

the duct plate adapter with swirl ring, which extends into the spinning rotor, on a larger scale, in section,

Fig. 4

a plan view of the swirl ring arranged on the duct plate adapter,

Fig. 5

a schematic diagram of the method according to the invention,

Fig. 6

1 shows a schematic diagram of the process which has been customary to date and represents the prior art,

Fig. 7

a side view of the swirl ring according to section VII-VII of Figure 4.

The open-end spinning device shown in FIG. 1 bears the overall reference number 1. As is known, the spinning device has a rotor housing 2, in which the spinning cup of a spinning rotor 3 rotates at high speed.
The spinning rotor 3 is supported with its rotor shaft 4 in the bearing gusset of a support disk bearing 5 and is acted upon by a machine-long tangential belt 6, which is started by a pressure roller 7.
The rotor shaft 4 is axially fixed, for example, by means of a permanent magnetic axial bearing 18.

As usual, the rotor housing 2, which is open towards the front, is closed during the spinning operation by a pivotably mounted cover element 8, into which a channel plate 26, which is not shown in FIG. 1 and has a circumferential lip seal 9, is inserted.
The rotor housing 2 is also connected via a corresponding suction line 10 to a vacuum source 11, which generates the spinning vacuum required in the rotor housing 2.

In a receptacle 28 of the channel plate 26, a channel plate adapter 12 is interchangeably arranged, which has a thread draw-off nozzle 13, the (not shown) mouth area of a fiber guide channel 14 and a swirl ring 37 according to the invention.
As indicated in the drawings, a thread take-off tube 15 connects to the thread take-off nozzle 13.

In addition, an opening roller housing 17 is fixed on the cover element 8, which is rotatably supported to a limited extent about a pivot axis 16.
The cover element 8 furthermore has bearing brackets 19, 20 on the back for mounting an opening roller 21 or a sliver feed cylinder 22.
The opening roller 21 is driven in the region of its whorl 23 by a circumferential, machine-long tangential belt 24, while the (not shown) drive of the sliver feed cylinder 22 is preferably carried out via a worm gear arrangement which is connected to a machine-long drive shaft 25.

FIG. 2 shows 1 on a larger scale and in section a partial view of the open-end spinning device shown schematically in FIG.
As indicated, the rotor housing 2, which is open at the front, is closed during operation by a fiber channel plate 26 of the cover element 8.
The fiber channel plate 26 is either attached to the cover element 8 as a separate component or integrated directly into the cover element 8.
The fiber channel plate 26 has an annular recess 27 in which the lip sealing element 9 is mounted.
In addition, the fiber channel plate 26 has a receptacle 28 which is open in the direction of the rotor housing 2 and whose lateral contact surface 29 is designed in the manner of a cone.

In the receptacle 28, a channel plate adapter 12 is aligned with its bearing body 30 at an exact angle and is easily detachable. The attachment takes place, for example, by means of a magnetic coupling 31.
The channel plate adapter 12 has a central bore for a thread take-off nozzle 13. A swirl ring 37 is also positioned in the area of the thread take-off nozzle 13 and has a multiplicity of swirl air bores 38.
The channel plate adapter 12 has on its side opposite the thread take-off nozzle 13 a connection means 32 which is designed as a ferromagnetic, annular disk. The connection means 32 is firmly pressed into the channel plate adapter 12 made, for example, of aluminum or plastic.

The magnetic coupling 31 further consists of two arranged symmetrically in the base of the receptacle 28, disc-shaped permanent magnets 33 which have a in the Recording 28 fixed bearing plate 34 on the Fiber channel plate 26 are set.

In addition, one is attached to the connection means 32 and through a rear opening of the fiber channel plate 26 partially outwardly projecting ejector 36 is present, which it in If necessary, simply loosen the duct plate adapter 12 enabled by the fiber channel plate 26.

As can be seen in particular from FIGS. 3 and 4, the thread take-off nozzle 13 embedded in the channel plate adapter 12 is surrounded by a swirl ring 37. This swirl ring 37, which surrounds the thread take-off nozzle 13 in a circular manner, has numerous swirl air bores 38 pointing counter to the direction of rotation R of the spinning rotor 3.
The individual swirl air bores 38 are connected via an annular channel 39, which is either connected to an overpressure source 41 via an air supply line 40 or connected to the atmosphere.
In the latter case, the air flow at the swirl air bores 38 is generated via the spinning vacuum generated by the vacuum source 11.

The swirl air bores 38 arranged in the swirl ring 37 each have a relatively small diameter, preferably between 0.2 and 1.0 mm.
In addition, the swirl air bores 38, as can be seen, for example, from FIG. 7, are arranged at an angle to the plane of rotation RE of the yarn leg 44, that is to say the air streams ELS emerging from the swirl air bores act on the rotating yarn leg at a so-called righting angle α, which is between 10 degrees and 30 degrees is.

In particular, the small diameters of the swirl air bores 38 have the advantage that, with a sufficiently high air flow speed, only a relatively small amount of air is required to bulge the rotating yarn leg 44.
It is thereby reliably prevented that the suction flow effective in the area of the spinning rotor edge is adversely affected and the economy of the spinning device is thus deteriorated.

Function of the method according to the invention or corresponding device:

As is known, open-ended rotor spinning works with both real wire and false wire, both types of twist being applied to the rotating yarn leg.
The real wire is produced by the spinning rotor 3 rotating at high speed, while the false wire is essentially introduced via the thread draw-off nozzle 13. The twists applied to the yarn legs 44 propagate into the rotor groove 46 of the spinning rotor 3 and collect the individual fibers fed in via a fiber guide channel 14 in the so-called binding zone 45.
The new yarn is then drawn off via the take-off rollers 43 and runs, for example, via a torque stop 42.

As indicated in FIG. 6, in the spinning processes known from the prior art, the rotating yarn leg 44 usually has an almost straight course.
That is, the yarn leg 44 only kinks relatively sharply immediately in front of the binding zone 45 lying in the rotor groove 46. This sharp kink greatly impedes the spreading of sufficient rotations into the area of the rotor groove 46, that is to say, specifically into the integration zone 45.
In addition, since the yarn tensile force before the kink is relatively low, there is also the risk that double twists, so-called cylinder coils, are generated there.

With the method according to the invention, which is based on FIG the aforementioned disadvantages are avoided. That is, by a pneumatic force F, which is contrary to the Circulation direction U on the between the thread take-off nozzle 13 and Rotating groove 44 extending, rotating yarn leg 44th is applied, this is against its direction of rotation U bulged.

As can be seen, this radius of curvature significantly increases the radius of curvature between the yarn leg 44 and the binding zone 45, thereby facilitating the spreading of the yarn twist from the yarn leg 44 into the binding zone 45.
Pneumatic bulging also produces a somewhat greater yarn tensile force in this area and correspondingly a greater yarn tensile force counter moment.
This larger yarn tensile force counter moment limits the size of the false wire to such an extent that the method according to the invention leads to an improvement in the quality of the yarn produced, both with regard to the structure, the tenacity, the elongation at break and the working capacity.

Claims (12)

Process for spinning textile staple fibers by means of a spinning rotor, which rotates at high speed in a rotor housing which can be pressurized by a fiber channel plate, the staple fibers fed into the spinning rotor being collected in a rotor groove, twisted together in a binding zone to form a yarn and then forming a yarn leg, which extends between the rotor groove and a thread take-off nozzle,
characterized in that a pneumatic force (F) is applied to the yarn leg (44), which bulges the yarn leg (44) against its direction of rotation (U). Method according to claim 1, characterized in that a plurality of individual air streams (ELS) act on the yarn leg (44). Method according to claim 2, characterized in that the individual air flows (ELS) emerge from swirl air bores (38) of a swirl ring (37) surrounding the thread take-off nozzle (13). Method according to claim 3, characterized in that the individual air flows (ELS) act on the yarn leg (44) at an uprighting angle (α) of between 10 degrees and 30 degrees. Method according to claim 3, characterized in that the yarn leg (44) rotates at a distance (a) between 0.5 and 1.5 mm in front of the swirl air bores (38). Device for carrying out the method according to claim 1, characterized in that there is a fiber channel plate (26) closing the rotor housing (2) of the open-end spinning device (1) and that in the area of the fiber channel plate (26) there are a large number of counter-rotating (U ) of the twine leg (44) directed swirl air bores (38) are arranged, which surround the thread take-off nozzle (13) in a ring shape. Apparatus according to claim 6, characterized in that the swirl air bores (38) are arranged on a duct plate adapter (12) which can be fixed interchangeably in a receptacle (28) in the fiber duct plate (26). Apparatus according to claim 6, characterized in that the swirl air bores (38) form a swirl ring (37), between 20 and 40 swirl air bores (38) being provided in each case. Device according to claim 6, characterized in that the swirl air bores (38) each have a diameter between 0.2 and 1.0 mm. Apparatus according to claim 6, characterized in that the swirl air bores (38) run at an uprighting angle (α) between 10 degrees and 30 degrees to the plane of rotation (RE) of the yarn leg (44). Apparatus according to claim 6, characterized in that the swirl air bores (38) are connected on the input side to a positive pressure source (41). Device according to claim 6, characterized in that an additional negative pressure can be applied to the rotor housing (2) and the swirl air bores (38) are connected to the atmosphere on the inlet side.

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