EP3680373B1 - Fibre guide element for a spinning nozzle and spinning nozzle provided with same - Google Patents

Description

The present invention relates to a fiber guide element for a spinneret of an air-jet spinning machine, wherein the fiber guide element, when used as intended, serves to guide a fiber structure entering the spinneret in a predetermined transport direction, the fiber guide element having a fiber guide surface for guiding the fiber structure, and the fiber guide surface having an inlet area, a central area downstream of the infeed area in said transport direction and an outfeed area downstream of the central area in said transport direction.

Furthermore, a spinneret for an air-jet spinning machine with a fiber guide element for guiding a fiber assembly entering the spinneret is proposed.

Corresponding spinnerets are used to produce a yarn from an elongated fiber structure with the aid of a turbulent air flow generated by air nozzles within a turbulence chamber of the spinneret. The fiber structure is supplied by a drafting system that evens out the fiber structure before it enters the spinneret. The inlet opening of the spinneret is formed or delimited by a fiber guide element, which serves to guide the fibers of the fiber assembly entering the spinneret.

After entering the spinneret, the outer fibers of the fiber structure are wound around the inner fibers (core fibres) in the area of the inlet of a usually spindle-shaped yarn-forming element placed in the turbulence chamber, so that a yarn is formed as a result, which finally passes through a discharge channel of the yarn-forming element from the Swirl chamber and thus deducted from the spinneret and wound onto a sleeve using a winding device. Corresponding yarn formation elements are in the EP 3 243 942 A1 , the EP 1 335 050 A2 or the CN 103 924 333 B shown.

In order to prevent the rotation of the fiber structure from propagating counter to the direction of transport of the fiber structure outside the spinneret and here in particular into the area of the drafting system, various fiber guiding elements are already known. The aim of these fiber guide elements is usually to deflect or deflect the fiber structure transversely to the transport direction, with this deflection or deflection acting as a twist stop and preventing the twist of the fiber structure from propagating from the turbulence chamber to the outside of the spinneret. In this context, purely by way of example EP 2 009 151 B1 or the JP 2773670 B2 referred.

The object of the present invention is to propose a fiber guiding element which is characterized by a particularly good anti-twist effect while nevertheless guiding the fiber structure gently.

The object is achieved by a fiber guide element or a spinneret equipped therewith with the features of the independent patent claims.

In principle, the fiber guiding element according to the invention also has a fiber guiding surface for guiding a fiber structure. The fiber guide surface is composed of an inlet area, a central area arranged downstream of the inlet area in the transport direction mentioned, and an outlet area arranged downstream of the central area in the transport direction mentioned.

When the fiber guide element is used as intended (i.e. after it has been installed in a spinneret of an air-jet spinning machine), the areas mentioned are successively passed by the fiber structure in the direction of transport. The areas together form the mentioned fiber guiding surface of the fiber guiding element.

According to the invention, the geometry of the middle area differs from that of the inlet area and also the geometry of the outlet area in that only the middle area is rotated (at least in sections) about the longitudinal axis of the fiber guiding element. In contrast to this, both the inlet area and the outlet area are designed in a non-twisted manner in relation to the longitudinal axis of the fiber guiding element.

So while the fiber structure is guided along a twisted surface in the middle area and thus on a helical path, the path along which the fiber structure is guided in the inlet area and in the outlet area lies in one plane or on a convex or concave, preferably channel-shaped, surface (Depending on how the inlet area or the outlet area are designed geometrically).

In particular, it is advantageous if the inlet area, the middle area and/or the outlet area is formed at least in sections by a flat, concave, preferably channel-shaped, or convex surface. If the inlet area is a convex or concave surface, it is advantageous if the corresponding surface section has, at least in sections, a radius of curvature R that is 1 mm or greater. As a result, the fibers of the fiber structure are deflected transversely to the transport direction, as a result of which a twist-stopping effect is exerted on the fiber structure.

Furthermore, it is provided that the inlet area is rotated relative to the outlet area by an angle γ with respect to the longitudinal axis, the amount of which is between 1° and 120°, preferably between 70° and 90°. The angle is the angle that a dividing line between the lead-in area and the middle area encloses with a dividing line between the middle area and the outlet area. The slope of the central area is preferably constant, as seen in the direction of transport.

Furthermore, it is advantageous if the central area and the outlet area are separated from one another by a dividing line, with the smallest distance A between the dividing line and the longitudinal axis of the fiber guiding element being between 0.5 mm and 1.5 mm. The distance between the outlet area following the central area and the longitudinal axis should, however, be less than the distance A. This creates an elevation in the area of the mentioned dividing line, over which the fiber strand is guided when it enters the vortex chamber. In particular, this elevation prevents the twist of the yarn inside the spinneret from being able to propagate outside of the spinneret counter to the transport direction.

It is also advantageous if the outlet area has a first outlet section adjoining the central area in the transport direction mentioned and a second outlet section adjoining the first outlet section in the transport direction mentioned. Both outlet sections are preferably flat. It would also be conceivable to design the first outlet section and/or the second outlet section as a concave or convex surface.

Furthermore, it is advantageous if the first outlet section encloses an angle β with the second outlet section, the amount of which is between 180° and 160°. While in the former case both outlet sections lie in a common plane or at least a common plane touch, the first outlet section is inclined in the second case compared to the second outlet section. Preferably, the inclination is such that in the region of the transition between the first outlet section and the second outlet section, an elevation, in particular an edge, is produced which is directed away from the longitudinal axis of the fiber guiding element. This increase must be passed by the fiber structure on its way into the vortex chamber, whereby the increase in turn acts as a twist stop.

In particular, there are advantages if the first outlet section and/or the second outlet section enclose an angle with the longitudinal axis of the fiber guiding element, the amount of which is between 5° and 25°, preferably between 10° and 20°. It is advantageous if the first outlet section and the second outlet section enclose the same angle with the longitudinal axis. However, it is also conceivable that the corresponding angles are different, so that the above-mentioned increase occurs. In this case, the angle between the longitudinal axis and the first outlet section could also be greater than 25°. In particular, amounts of up to 70° are possible.

There are also advantages if the outlet area or the first outlet section and/or the second outlet section are formed at least in sections by a flat surface. In this case, the fibers of the fiber structure are guided in a relatively straight line. In contrast to this, it is advantageous if the middle area does not have any flat sections.

It is also advantageous if the second outlet section is formed by a lateral flattening of an otherwise frustoconical end section of the fiber guide element. The flattening is preferably a flat surface. The end section of the fiber guide element is therefore designed in the form of a truncated cone in sections, with the remaining area of the end section being formed by the flattening. In particular the plane in which the flattening lies should intersect with its longitudinal axis outside of the fiber guiding element.

The partially frusto-conical end portion preferably has a top surface defined by a perimeter of the flat and a pitch circle. In particular, the top surface should run perpendicular to the longitudinal axis of the fiber guiding element. In addition, it is advantageous if the pitch circle has a diameter of between 1 mm and 3 mm. Furthermore, the partially frusto-conical end section should have a height of between 0.5 mm and 1.5 mm.

It is also advantageous if the partially frustoconical end section has a lateral surface which intersects the top surface of the fiber guide element at an angle α of between 10° and 50°, preferably between 20° and 40°. An angle of essentially 30° is preferred. Since the end section is arranged after the installation of the fiber guide element in a spinneret in the area of the air nozzles through which the compressed air required for yarn production is blown in, the angle mentioned has an influence on the rotation of the fibers of the fiber structure. In this case, the stated angular range has proven to be advantageous.

It is advantageous if the fiber guiding element has, at least in sections, an outer surface lying on an imaginary cylinder. In particular, the named outer surface is the respective rear side of the inlet area, the middle area and the outlet area. The imaginary cylinder has an axis of symmetry which preferably runs parallel or congruent with the longitudinal axis of the fiber guiding element. In addition, the axis of symmetry should pass through the top surface of the end section mentioned above. Finally, it is advantageous when the imaginary cylinder has an outside diameter the magnitude of which is between 3 mm and 6 mm, preferably between 4 mm and 5 mm.

Furthermore, it is advantageous if the fiber guiding element has a longitudinal extent extending in the direction of the longitudinal axis, the amount of which is between 8 mm and 16 mm, preferably between 10 mm and 14 mm. While a short overall length of the fiber guide element is preferred for reasons of space in the entry area of the spinneret, a certain length is necessary in order to achieve the desired guidance of the fiber structure and the twist stopping effect associated therewith.

It is also advantageous if the inlet area has a longitudinal extent extending in the direction of the longitudinal axis, the amount of which is between 2 mm and 7 mm, preferably between 3 mm and 6 mm. The length mentioned should not be less than 2 mm, since the inlet area is intended to cause a gradual lateral deflection of the fiber structure, which would only be possible abruptly with a shorter length.

It is also advantageous if the central area has a longitudinal extent extending in the direction of the longitudinal axis, the amount of which is between 2 mm and 9 mm, preferably between 4 mm and 7 mm. An amount in the range mentioned is sufficient to allow the above-mentioned angle between the inlet area and the outlet area without the fibers of the fiber assembly being deflected in a helical manner too strongly.

It is also advantageous if the outlet area has a length extending in the direction of the longitudinal axis, the amount of which is between 1 mm and 4 mm, preferably between 2 mm and 3 mm. Preferably, the outlet area is seen in the transport direction in direction inclined along the longitudinal axis, so that the lateral deflection of the fiber structure in the area of the outlet area is reduced, viewed in the direction of transport. This reduction in the deflection should also take place gradually, with the mentioned longitudinal extension having proven itself to be positive.

Furthermore, a spinneret for an air-jet spinning machine is proposed, the spinneret comprising a fiber guide element, as is customary in the prior art. The fiber guide element is arranged in the area of the inlet of the spinneret and guides the fiber structure entering the spinneret.

In order to prevent the twist that is exerted on the fiber structure inside the turbulence chamber of the spinneret from propagating against the transport direction of the fiber structure to the outside of the spinneret, it is provided according to the invention that the fiber guide element is designed according to the previous or following description.

Of course, the spinneret includes the components or sections required for yarn production, such as in particular a yarn-forming element with a discharge channel and several air nozzles, via which compressed air can be introduced into the turbulence chamber during operation of the spinneret.

Furthermore, it is advantageous if the direction of rotation, in which the middle region is rotated about the longitudinal axis at least in sections, corresponds to the direction of rotation of the turbulent air flow, viewed in the transport direction. In other words: In relation to the longitudinal axis of the fiber guide element and seen in the transport direction of the fiber structure in the area of a fiber structure inlet of the spinneret, the central area of the fiber guide element has the same direction of rotation (clockwise or counterclockwise) as the turbulent air flow generated by the air nozzles within the turbulence chamber. The fiber structure is so when entering the spinneret through the Central section rotated about the longitudinal axis in a direction corresponding to the direction of rotation of the swirling air. The direction of rotation of the turbulent air is in turn determined by the alignment of the air nozzles.

Figur 1

einen Ausschnitt einer erfindungsgemäß Spinndüse, teilweise geschnitten,

Figuren 2 bis 5

verschiedene Ansichten eines erfindungsgemäßen Faserführungselements, und

Figur 6

einen ausgewählten Abschnitt eines weiteren erfindungsgemäßen Faserführungselements.

Further advantages of the invention are described in the following exemplary embodiments. They show, each schematically:

figure 1

a section of a spinneret according to the invention, partially sectioned,

Figures 2 to 5

different views of a fiber guide element according to the invention, and

figure 6

a selected section of a further fiber guiding element according to the invention.

figure 1 shows a section of a spinneret 2 of an air-jet spinning machine. Of the spinneret 2, only the inlet area for a fiber structure 3 that is relevant for understanding the present invention and part of the vortex chamber 16 that follows in the specified transport direction T of the fiber structure 3 are shown.

A spindle-shaped yarn-forming element 13, which is known in principle from the prior art, protrudes into the vortex chamber 16. Air nozzles 14 are also shown, via which compressed air is introduced into the spinneret 2 when the spinneret 2 is in operation, the air nozzles 14 being arranged in such a way that a turbulent air flow is produced in the region of the yarn-forming element 13 . Due to the turbulent air flow, the outer fibers of the fiber structure 3 entering the spinneret 2 are wound around the inner fibers, so that a yarn 17 is formed in the area of the yarn-forming element 13, which can finally be drawn off from the spinneret 2 via the draw-off channel 15.

In order to prevent the rotation of the yarn 17 from propagating outwards of the spinneret 2 counter to the transport direction T, the spinneret 2 has a fiber guide element 1 designed according to the invention, which can be fixed in the spinneret 2, for example by positive or non-positive locking.

The fiber guide element 1 itself is in the Figures 2 to 5 shown in more detail, where figure 5 represents a plan view of the fiber guide element 1 (based on figure 2 i.e. with a view from above).

As can be seen from the figures, the fiber guide element 1 has a fiber guide surface along which the fiber structure 3 is guided when it enters the spinneret 2 .

According to the present invention, this fiber guide surface is made up of three areas. In particular, the fiber guide element 1 has an inlet area 4 with which the fiber structure 3 first comes into contact when it is introduced into the spinneret 2 in the intended transport direction T. There is also a central area 5 which follows the inlet area 4 in the transport direction T and finally merges into an outlet area 6 through which the fiber structure 3 passes before it reaches the vortex chamber 16 .

In this context, the invention also provides that only the central area 5 is formed by a surface that is twisted in relation to the longitudinal axis L of the fiber guiding element 1 . The fibers are thereby guided along the central area 5 on a substantially helical or spiral path. In contrast to this, the inlet area 4 and the outlet area 6 , which is separated from the central area 5 by a dividing line 7 , are formed by individual surface sections which are either flat or convex in the direction of the fiber structure 3 are. The smallest distance between said dividing line 7 and the longitudinal axis L of the fiber guide element 1 is identified by the reference symbol A.

While the outlet area 6 can be formed by a single surface, it is particularly advantageous if it is composed of a first outlet section 8 and a second outlet section 9 following in the transport direction T. While the first outlet section 8 can be formed by a cut surface of a basically cylindrical base body of the fiber guide element 1, it is advantageous if the second outlet section 9 is formed as a flattened area 10 of an otherwise frustoconical end section 11 of the fiber guide element 1.

With regard to the inlet area 4, it is advantageous if this is not formed by a flat surface but by a surface curved convexly in the direction of the fiber structure 3, the radius of curvature being identified by the reference symbol R.

In particular, the fiber guide element 1 can be manufactured from an originally cylindrical base body, with individual sections of the base body being removed in such a way that the final shape with the named areas 4, 5 and 6 of the fiber guide surface and the partially frustoconical end section 11 is created. Correspondingly, the fiber guiding element 1 can have an outer surface 12 lying on an imaginary cylinder with a diameter D2, which adjoins the individual regions 4, 5 and 6 mentioned in the circumferential direction.

The axis of symmetry of the imaginary cylinder also runs congruently with the above-mentioned longitudinal axis L of the fiber guide element 1.

The frustoconical end section 11 also has a top surface 18 which preferably runs perpendicular to a longitudinal axis L of the fiber guide element 1 .

The above dimensions and angles can moreover in particular figures 2 and 5 refer, since for reasons of clarity they are not identified in all figures.

Thus, the fiber guiding element 1 has a longitudinal extent I extending in the direction of the longitudinal axis L, which in principle corresponds to the overall length of the fiber guiding element 1 .

Likewise, the inlet area 4 has a defined longitudinal extent II. The longitudinal extension of the central area 5 is provided with the reference symbol III. Finally, the outlet area 6 also has a certain longitudinal extension, identified by the reference symbol IV.

The above-mentioned end section 11 of the fiber guide element 1, which is in the form of a laterally flattened truncated cone, has a height indicated by the letter H, while the top surface 18 of the end section 11 has a diameter D1.

Finally, with regard to the angles mentioned in the general description figures 2 and 5 referred. These show the angle α between the lateral surface of the partially frustoconical end section 11 and the top surface 18 of the fiber guide element 1, the angle β between the first outlet section 8 and the second outlet section 9, the angle δ between the longitudinal axis L and the first outlet section 8 or the second outlet section 9 and the angle γ between the inlet area 4 and the outlet area 6, which arises from the twisting of the central area 5.

With regard to the amounts of the stated dimensions and angles, reference is made to the general description.

It should also be pointed out that the first outlet section 8 can be tilted at an angle of between 0° and 20° relative to the second outlet section 9, so that the sections 8, 9 mentioned do not have to lie in a common plane.

Finally shows figure 6 the outlet area of a further embodiment of a fiber guiding element 1 according to the invention (partially cut off at the bottom). As can be seen from this figure, the outlet area 6 can be formed at least in sections by a concave surface, which is channel-shaped in the example shown. Of course, this shape can also be implemented in the inlet area 4 or middle area 5 in addition or as an alternative.

The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the claims are also possible, as is any combination of the features described.

Reference List

1

fiber guiding element

2

spinneret

3

fiber bandage

4

Inlet area of the fiber guide surface

5

Central area of the fiber guide surface

6

Exit area of the fiber guide surface

7

Separation line between the middle area and the outlet area

8th

first outlet section

9

second outlet section

10

flattening

11

partially frusto-conical end portion

12

outer surface lying on a cylinder

13

yarn forming element

14

air nozzle

15

culvert

16

vortex chamber

17

yarn

18

top surface

I

longitudinal extent of the fiber guide element extending in the direction of the longitudinal axis

II

Longitudinal extent of the inlet area extending in the direction of the longitudinal axis

III

longitudinal extension of the middle region extending in the direction of the longitudinal axis

IV

longitudinal extent of the outlet area extending in the direction of the longitudinal axis

A

smallest distance between the dividing line delimiting the central area from the outlet area and the longitudinal axis of the fiber guiding element

D1

Diameter of the top surface of the end section of the fiber guiding element

D2

Outer diameter of the cylinder on which at least part of the outer surface of the fiber guiding element lies

H

Height of the partially frusto-conical end portion of the fiber guiding element

L

longitudinal axis

T

Transport direction of the fiber structure

R

Radius of curvature of the inlet area

a

Angle between the lateral surface of the partially frustoconical end section and the top surface of the fiber guide element

β

Angle between the first run-out section and the second run-out section

δ

Angle between the longitudinal axis and the first run-out section and/or the second run-out section

g

Angle between inlet area and outlet area

Claims (15)

1. A fiber guide element (1) for a spinning nozzle (2) of an air-jet spinning machine, the fiber guide element (1) in the intended usage being used to guide a fiber strand (3) entering the spinning nozzle (2) in a prescribed transport direction (T),

   - the fiber guide element (1) comprising a fiber guide surface for guiding the fiber strand (3), and

   - the fiber guide surface comprising an entry region (4), a middle region (5) disposed downstream of the entry region (4) in said transport direction (T) and a discharge region (6) disposed downstream of the middle region (5) in said transport direction (T), the entry region (4) and the discharge region (6) each being implemented to be untwisted with respect to a longitudinal axis (L) of the fiber guide element (1), while the middle region (5) is rotated at least in segments about the longitudinal axis (L)

   characterized in that
   the entry region (4) is rotated relative to the discharge region (6) with respect to the longitudinal axis (L) by an angle γ, the amount of which is between 1° and 120°.
2. The fiber guide element (1) according to the preceding claim, characterized in that the entry region (4) is rotated relative to the discharge region (6) with respect to the longitudinal axis (L) by an angle γ, the amount of which is between 70° and 90°.
3. The fiber guide element (1) according to any one of the preceding claims, characterized in that the entry region (4), the middle region (5) and/or the discharge region (6) is formed at least in segments by a flat, concave, preferably trough-shaped, or convexly curved surface, wherein the entry region (4) in the second case preferably and at least in segments has a radius of curvature R, the amount of which is 1 mm or greater.
4. The fiber guide element (1) according to any one of the preceding claims, characterized in that the middle region (5) and the discharge region (6) are delimited from one another by a dividing line (7), wherein the smallest distance A between the dividing line (7) and the longitudinal axis (L) of the fiber guide element (1), the amount of which is between 0.5 mm and 1.5 mm.
5. The fiber guide element (1) according to any one of the preceding claims, characterized in that the discharge region (6) comprises a first discharge section (8) connected to the middle region (5) in said transport direction (T) and a second discharge section (9) connected to the first discharge section (8) in said transport direction (T), wherein the first discharge section (8) with the second discharge section (9) encloses an angle β, the amount of which is between 180° and 160°.
6. The fiber guide element (1) according to the preceding claim, characterized in that the first discharge section (8) and/or the second discharge section (9) enclose an angle δ with the longitudinal axis (L) of the fiber guide element (1), the amount of which is between 5° and 25°, preferably between 10° and 20°.
7. The fiber guide element (1) according to any one of the preceding claims, characterized in that the discharge region (6) or the first discharge section (8) and/or the second discharge section (9) are formed at least in segments by a flat surface.
8. The fiber guide element (1) according to any one of the preceding claims 5 to 7, characterized in that the second discharge section (9) is formed by a lateral flattening (10) of an otherwise frustoconical end section (11) of the fiber guide element (1), wherein the otherwise frustoconical end section (11) preferably comprises a cover surface (18) which is bounded by a boundary line of the flattening (10) and a pitch circle, wherein the pitch circle has a diameter D1, the amount of which is between 1 mm and 3 mm, and/or the otherwise frustoconical end section (11) has a height H, the amount of which is between 0.5 mm and 1.5 mm.
9. The fiber guide element (1) according to the preceding claim, characterized in that the otherwise frustoconical end section (11) comprises a shell surface which intersects the cover surface (18) of the fiber guide element (1) at an angle α, the amount of which is between 10° and 50°, preferably between 20° and 40°.
10. The fiber guide element (1) according to any one of the preceding claims, characterized in that the fiber guide element (1) comprises at least in segments an outer surface (12) lying on a cylinder, wherein the axis of symmetry of the cylinder runs parallel or congruent with the longitudinal axis (L) of the fiber guide element (1), wherein the cylinder preferably has an outer diameter D2, the amount of which is between 3 mm and 6 mm, preferably between 4 mm and 5 mm.
11. The fiber guide element (1) according to any one of the preceding claims, characterized in that the fiber guide element (1) has a longitudinal extension I extending in the direction of the longitudinal axis (L), the amount of which is between 8 mm and 16 mm, preferably between 10 mm and 14 mm.
12. The fiber guide element (1) according to any one of the preceding claims, characterized in that the entry region (4) has a longitudinal extension II extending in the direction of the longitudinal axis (L), the amount of which is between 2 mm and 7 mm, preferably between 3 mm and 6 mm.
13. The fiber guide element (1) according to any one of the preceding claims, characterized in that the middle region (5) has a longitudinal extension III extending in the direction of the longitudinal axis (L), the amount of which is between 2 mm and 9 mm, preferably between 4 mm and 7 mm.
14. The fiber guide element (1) according to any one of the preceding claims, characterized in that the discharge region (6) has a longitudinal extension IV extending in the direction of the longitudinal axis (L), the amount of which is between 1 mm and 4 mm, preferably between 2 mm and 3 mm.
15. A spinning nozzle (2) for an air-jet spinning machine comprising a fiber guide element (1) for guiding a fiber strand (3) entering the spinning nozzle (2) in a transport direction (T), and comprising air nozzles (14) for generating a turbulent air flow within the spinning nozzle (2), characterized in that the fiber guide element (1) is implemented according to any one of the preceding claims, wherein the direction of rotation in which the middle region (5) is rotated at least in segments about the longitudinal axis (L), when viewed in the transport direction (T), preferably corresponds to the direction of rotation of the turbulent air flow.

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