EP1584715A1 - Method of manufacturing a yarn in an air-vortex spinning machine - Google Patents

Abstract

In a textile spinning process to produce yarn the spinning tension is less than 20 cN. The process is effected in a spinning machine with outlet rollers from a spinning box. The spinning box has a spindle has an air inlet with a vortex chamber. The yarn is surrendered to rollers under predefined tension value and at a speed V(L greater than 300 m/min. The spinning box incorporates a fibre feed passage with a fibre thread surface guide upstream from the vortex chamber.

Description

The invention relates to a method for producing a yarn in one Air-jet spinning machine according to the preamble of patent claim 1.

The present invention relates to the field of air spinning machines. Air-jet spinning machines have a multiplicity of spinning stations. In each spinning station will a yarn spun from a fed fiber longitudinal structure. This is the fiber longitudinal structure first refined, that is, the amount of fiber per unit length is reduced by delay. Then the refined fiber structure in the spinning station spun by twisting into a yarn. For this purpose, the spinning station Fiber guide element, which leads the fiber structure in a vortex chamber, where made a yarn on a spindle by the known vortex air spinning process becomes.

Investigations have shown that there is a direct correlation between the spinning tension and the spinning result. FIG. 1 shows a schematic representation of the components of an air-jet spinning machine. As explained above, the fiber longitudinal structure 1 is refined in a drafting system 69, spun in the spinning box 5 into a yarn 70 and fed by means of withdrawal rollers 64 via a yarn laying device 67 to a yarn package 68. The term spinning tension F _S is now understood to mean the force F _S to be indicated in the units [N] or [cN] which acts on the yarn between spin box 5 and take-off 63.

For further explanation, reference is now made to FIG. The spin box 5 has a swirl chamber 10, in which the air flowing in through the air inlet opening 61 generates a swirling flow which rotates around the surface of the fiber structure 1 located edge fibers 62 and thereby spun the fiber strand 1 into a yarn 70. The above-mentioned spinning tension F _s is mainly caused by the running-up of edge fibers 62 at the inlet mouth 9 of the spindle 7. Thus, these forces have a special characteristic, which is fundamentally different from the voltage characteristics of other methods, such as in ring, rotor or two-nozzle spinning.

Because in the air spinning process - an example of a corresponding machine is to be found in the document EP 1 335 050 A2 [2] - essentially cause the rotating fiber ends or the later Umwindefasern the spun yarn 70, the spinning tension F _S , there is a direct correlation between spin result - That is, the yarn produced - and the spinning tension F _S. The term "spinning result" subsumes the properties of yarn quality and reliability of the spinning process. By reducing the spinning speed, the spinning tension can also be reduced to values that allow an improved spinning result. However, this is not practical for the required high spinning performance with required spinning speeds v _L > 300 m / min on the one hand and on the other hand this leads to an impairment of the spinning result for the following reason: The edge fibers should ideally be at an angle of about 45 ° the fiber strand 1 to a yarn 70 are spun. This angle is now essentially determined by the spinning speed, taking into account the swirling of the air, and this must therefore be within a normal range of around 300 m / min.

The present invention is therefore based on the object, a method for Specify spinning a yarn in an air-spinning machine, in spite of high Spinning speeds an ideal spinning tension is adjustable, whereby an optimal Spinning result is achieved in particular with regard to the yarn quality.

This object is achieved by the method specified in claim 1.

As a result of the process parameter according to the invention, according to which the spinning tension F _{S has} a value range F _S <20 cN, a method is provided which enables a spinning tension at high speeds, which in particular ensures high reliability, so that, for example, the risk of yarn breaks is greatly reduced is.

• Anpassen des Spinnverzuges s_v zwischen dem Streckwerkauslauf und den Abzugswalzen nach der Spinnbox, so dass s_v ≤ 1.0.
• Anpassen des Pressluftdruckes p der Luft, welche in die Wirbelkammer einströmt, auf Werte von 3 bis 6 bar, vorzugsweise von 4 bis 5 bar.
• Erzielung einer starken Saugwirkung durch den in der Wirbelkammer erzeugten Luftwirbel, um Luft aus dem Zwickelbereich nach der Auslaufklemmlinie des Streckwerkes anzusaugen. Dazu gibt es verschiedene konstruktive Gestaltungsmöglichkeiten, welche in den nachfolgend aufgeführten Ausführungsformen beschrieben werden.
• Optimale Gestaltung der Wirbelkammer. Auch hierzu existieren verschiedene konstruktive Gestaltungsmöglichkeiten, welche ebenfalls in den nachfolgend aufgeführten Ausführungsbeispielen angegeben werden.

In order to achieve this desired value range for the spinning tension F _S and thus to optimize the spinning result, one or more of the following measures can be taken, for example:

• Adjusting the spinning warp s _v between the drafting outlet and the take-off rolls after the spinning box, so that s _v ≤ 1.0.
• Adjusting the compressed air pressure p of the air, which flows into the vortex chamber, to values of 3 to 6 bar, preferably from 4 to 5 bar.
• Achieving a strong suction by the vortex generated in the vortex chamber air vortex to suck air from the gusset area after the outlet clamping line of the drafting system. For this purpose, there are various design options, which are described in the embodiments listed below.
• Optimal design of the vortex chamber. Also for this purpose, there are various structural design options, which are also indicated in the embodiments listed below.

Advantageous embodiments of the invention are also in dependent other Claims specified.

Figur 1

Schematische Darstellung der Komponenten einer Luftspinnmaschine;

Figur 2

Partielle Darstellung einer Spinnbox, insbesondere zur Erläuterung des Eintritts eines Faserverbandes in die Spindel;

Figur 3

Faserförderkanal mit einer Tunnelauskleidung;

Figur 4

Detailliertere Darstellung des Absatzes der Tunnelauskleidung und der Lufteintrittsöffnung in einer ersten Ausführungsform;

Figur 5

Detailliertere Darstellung des Absatzes der Tunnelauskleidung und der Lufteintrittsöffnung in einer zweiten Ausführungsform;

Figur 6

Darstellung einer eine Umlenkkante aufweisende Faserführungsfläche in einem Faserführungskanal;

The invention will be explained in more detail with reference to drawings, for example. Showing:

FIG. 1

Schematic representation of the components of an air-spinning machine;

FIG. 2

Partial representation of a spinning box, in particular for explaining the entry of a fiber structure into the spindle;

FIG. 3

Fiber conveying channel with a tunnel lining;

FIG. 4

More detailed representation of the paragraph of the tunnel lining and the air inlet opening in a first embodiment;

FIG. 5

More detailed representation of the paragraph of the tunnel lining and the air inlet opening in a second embodiment;

FIG. 6

Representation of a deflecting edge having fiber guide surface in a fiber guide channel;

1 shows a schematic representation of the components of an air- _{jet spinning machine} : With v _ausl and v _abz the speeds occurring and shown by the reference numeral 71, the location at which the relevant process parameter spinning tension F _S occurs for this invention.

In Figure 2, a spinning box 5 is shown in a detailed representation as they State of the art corresponds and already explained in the introduction to the description has been.

FIG. 3 shows a first embodiment within a spinning box 5, so that the desired spinning tension F _{S is} achieved. The spin box 5 has a fiber guide element 3 and then a spindle 7 with yarn guide channel 8. The fiber guide element 3 is surrounded by a hollow cylindrical tunnel lining 17. The tunnel lining 17 may be made in one or more pieces. The fiber conveying channel 4 is encased by the tunnel lining 17. The tunnel lining 17 is shaped in such a way that a shoulder 18 for the swirl chamber housing 15 is formed at the end of the fiber conveying channel 4. The end face of the shoulder 18 serves for the emerging from the jet nozzles 13.1 fluid - usually - air as a guide surface. The outlet openings of the jet nozzles for the fluid in the vortex chamber 14.1 have an elliptical shape. The fiber guide element 3 and the associated tunnel lining 17 are installed in the swirl chamber housing 15. As will be shown in the following FIGS. 4 and 5, the swirl chamber housing 15 does not necessarily also comprise the fiber guide element 3 and its tunnel lining 17. The two last-mentioned elements can also have their own housing, which adjoins the swirl chamber housing 15 (see FIG. 5). In total, four individual jet nozzles 13.1 are provided. The jet nozzles 13.1 have an angle of inclination α to the fiber transport direction 19. The inclination angle α is in a value range of 45 ° to 88 °. The angle of inclination of the end face of the shoulder 18 to the material flow direction has the same amount in this first embodiment. It is easy to see how the vortex chamber 14.1 adjacent end face 20 of the fiber guide element 3 has the same inclination angle to the material flow direction 19 as the holes of the jet nozzles 13.1.

Figures 4 and 5 show two further embodiments for the heel of the tunnel lining, so that the desired spinning tension F _{S is} achieved. The vortex chamber housing 15 adjoins a housing 32 for the fiber guide element 3 and the tunnel lining. The embodiment shown according to FIG. 4 has a tunnel lining 26, which is shaped in such a way that the shoulder 29 with an inclination angle β is formed at the end of the fiber conveying channel 4. Preferably, the tunnel lining 26 has a thickness a, which lies in a value range of 0.1 to 3 mm. In the immediate vicinity of the front side of the shoulder 29, the bore of the jet nozzle 13.1 is arranged in the swirl chamber housing 15. The shoulder 29 is arranged so close to the opening of the jet nozzle 13.1, that its end face serves as a guide surface for the exiting flow. The paragraph 29 is arranged in alignment with the bore, which in turn is arranged flush with the inner surface or lateral surface of the vortex chamber 14.1, so that the bore 13.1 «tangentially aligned» enters the inside of the vortex chamber housing 15, or tangentially into the vortex chamber 14.1. However, preference is given to angles of inclination α to the material flow direction, which lie in a value range of 60 ° to 70 °. The inclination angle β of the front side of the shoulder 29 may have a value other than the inclination angle α. The most suitable angle of inclination β can best be determined empirically for the specific application. Experiments have shown that in most cases, an inclination angle β is suitable, which has the same value as the inclination angle α. However, an embodiment with α ≠ β is also possible. In FIG. 5, the bore 13. 1 is arranged at a distance d from the shoulder 31 of the tunnel lining 28. The distance d lies in a value range of 0.5 mm to 2 mm, preferably 0.9 mm to 1.3 mm, preferably 1.1 mm.

FIG. 6 shows a cross section through a spinning box 5 in another embodiment in order to achieve the process parameter value of the spinning tension F _S <20 cN according to the invention. The fiber guide element 3c shown has a fiber guide surface 16 with a deflection point 72. The deflection point 72 is formed by the fiber guide surface 16: The fiber guide surface 16 consists of two flat surfaces whose common cutting line forms the deflection point 72. As a result of this design of the fiber guiding surface 16, the fibers of the fiber structure 1 (not shown in FIG. 6) are guided in a substantially flat arrangement lying next to one another. A contribution to this flat arrangement also provides the fiber discharge edge 6. The deflection point 72 is dimensioned so that the fibers of the fiber structure 1 are deflected such that the free fiber ends of the fibers, which are located in the fiber structure, can lift off. At the deflection point 72, the front and the rear fiber ends are lifted above all those fibers which are located on the surface of the fiber structure 1 or immediately below. At the deflection point 72, both front and rear fiber ends are lifted. The lifting of fiber ends at the deflection point 72 increases the number of free fiber ends in the fiber structure. By "free fiber ends" is meant those ends which are not within the staple fiber strand or are not connected to other fibers and thereby can be trapped by the vortex flow. By increasing the number of free fiber ends increases the number of Umwindefasern in the yarn and the quality of the spinning process itself. This design of the fiber guide surface has surprisingly a further advantage over the prior art. The reduction of the cross section A of the fiber conveying channel 4 within a range has shown that the amount of air V flowing through was surprisingly increased. Due to the increased amount of air V, the fiber guide between the outlet rollers and the input of the fiber guide element 3c, ie before the fiber guide element 3c, can be substantially improved. The number of production interruptions, caused by breaks of the fiber structure immediately after the discharge rollers can be reduced thereby. Likewise a measurable improvement of the yarn quality could be determined. Experiments have shown that particularly good results are achieved when the cross section A of the fiber conveying channel 4 remains constant up to the deflection point 72 and from the deflection point or additional edge 72 the following cross-section B of the fiber conveying channel increases. The area of the cross section A of the fiber conveying channel 4 up to the deflection point 72 is preferably in a value range of 0.5 mm ² to 10 mm ² . Table 1 contains measures of the quantities C, D, E and F contained in FIG. 6, which permit a spinning tension F _S > 20 cN. Measurements of the embodiment according to FIG. 6 description Symbol unit value range preferred value range horizontal distance between the deflection point 72 and the fiber delivery edge 6 C
[Mm] 1 .. 4 1.5 .. 2.5 vertical distance between the deflection point 72 and the fiber delivery edge 6 D
[Mm] 0.2 .. 1 0.4 .. 0.7 horizontal distance between fiber delivery edge 6 and inlet mouth 9 e
[Mm] 0.1 .. 1 0.3 .. 0.7 vertical distance F between the fiber delivery edge 6 and the center line of the yarn guide channel 8 F
[in% diameter of yarn guide channel] 10 .. 40

In order to enable the desired spinning tension F _s > 20 cN, the air (fluid) to be supplied preferably has a pressure p which lies in the following value range: 3 bar <p <6 bar.

In a further embodiment of the present invention, a spinning distortion S _V ≥ 1.0. The spinning delay S _{V is} defined by the following quotient: S V : = v abz / v foreign ,

v_abz Umlaufgeschwindigkeit der Abzugwalzen;

v_ausl Umlaufgeschwindigkeit der Auslaufwalzen.

Where:

v _abz rotational speed of the withdrawal rollers;

v _{Out of} circulation speed of the exit rollers.

The condition S _V ≦ 1.0 means that the peripheral speed of the take-off rollers 64 has to be at most equal to that of the run-out rollers 2 of the drafting system 69. In this case, S _{V is} preferably in the range of 0.96 to 1.0.

F _S = Spinnspannung in [cN]

Nm = Garnfeinheit in metrischer Nummer [m/g]

ν _L = Garnliefergeschwindigkeit in [m/min]

On the basis of tests it could be shown that the resulting spinning tension can be determined on the basis of a given metric number of the spun yarn 1 (yarn count) and a spinning speed to be achieved according to the following formula and thereby the operating parameters on a spinning machine have to be predetermined and regulated accordingly: F S = 6.6 + 0.05 * (100 - nm ) + 0.0096 · (ν L - 350) in which:

F _S = spinning tension in [cN]

Nm = yarn count in metric number [m / g]

ν _L = yarn delivery speed in [m / min]

The following Table 2 contains in the middle column the calculated from metric number and spinning speed spinning tension F _S ; The first two columns show the scatter values defined by ± 20%. Value table with calculated spinning tension F _S Spincasting F _S lower limit (-20%) in [cN] Spincasting F _S upper limit (+ 20%) in [cN] Spinning tension F _S [cN] metric number mN [g / m] Spinning speed v _L [m / min] 7.664 11.496 9,580 50 400 7.110 10,666 8,888 60 380 6,480 9,720 8,100 70 350 5,696 8.544 7,120 80 300

The teaching of the invention can be achieved by a free combination of the above in the Figures 3 to 6 explained embodiment of the spin box 5 and its spin box elements such as. Fiber entrance edge 31, fiber discharge edge 29 or deflection point 72 as well can be realized freely with the aforementioned operating parameters pressure and spinning delay.

List of reference numbers used in FIGS. 1 to 6

1

Fiber, fiber strand, staple fiber strand

2

Pair of delivery rollers; delivery rollers

3, 3c

Fiber guide element

4

Fiber guide channel, fiber conveying channel

5

spinning box

7

spindle

8th

yarn guide

9

Inlet mouth of the spindle 7

10

swirl chamber

11

incoming air

12

drafting system

13

fluid means

13.1

jets

14

room

14.1

swirl chamber

15

Eddy chamber housing

16

Fiber guide surface, flat fiber guide surface

17

tunnel lining

17.1

Half shell of the tunnel lining

18

paragraph

19

Material flow direction, transport direction

20

End face of the fiber guide element 3 in the vortex chamber

23

Center line of the yarn guide channel

26

tunnel lining

28

tunnel lining

29

Heel with angle of inclination β

31

paragraph

32

Housing for fiber guide element and tunnel lining

60

spinning unit

61

Inlet opening airflow

62

edge fibers

63

deduction

64

off rolls

65

friction roller

66

thread monitor

67

Cross-winding device

68

bobbin

69

drafting system

70

yarn

71

Place where the spinning tension occurs and is measurable

72

deflection

List of reference numerals used in FIG

20

nozzle block

21

jets

22

swirl chamber

23

vent channel

25

Conveying direction of the sucked air

26

Fiber conveying channel

27

Fiber conveying element

28

Fiber guide surface

29

Fiber delivery edge

30

face

31

Fiber take-up edge

32

spindle

36

Cone of fiber conveying element 27

37

Support element for fiber conveying element 27

38

Center line of jet nozzles 21 and blowing direction

39

Fiber conveying roller

45

yarn guide

47

center line

List of used symbols

v _abz

Circulation speed of the withdrawal rollers

v _ausl

Circulation speed of the exit rollers

α

Inclination angle of the jet nozzles to the fiber or material transport direction

β

Inclination angle of the heel to the material flow direction 19

a

Thickness of the tunnel lining 26

d

Distance between jet nozzles 13.1 and paragraph 31

A

Cross section before deflection

B

Cross section after deflection

C

Distance parallel to the center line 23 of the deflection point 72 to the Fiber delivery edge 6

D

Distance vertical to the center line 23 from the deflection point 72 to Fiber delivery edge 6

e

Distance parallel to the center line 23 from the fiber discharge edge 72 to the Inlet mouth 9 of the spindle 7

F _S

Spinning tension in [cN]

F

Distance vertical to the centerline 23 from the fiber delivery edge 72 to the Center line 23 of the Garnführungskanals 8

G

Width of the reduced fiber delivery edge 6

nm

metric number in [m / g], length per mass; Site in [1]

p

Pressure in [bar]

S _V

spinning draft

v _L

Spinning speeds in m / min

List of abbreviations used

ISO

International Standard Organization

List of used units

bar

Print; ISO Unit

N, cN

Newton, Centi-Newton; ISO Unit

m

Meter; ISO Unit

min

minute

literature sources

[1] Expertise Clothing, 5th edition ISBN 3-8085-6205-6; 1998 Publisher Europa-Lehrmittel, Nourney, Vollmer GmbH & Co., 42781 Haan-Gruiten

[2] EP 1 335 050 A2 textile processing machine with a fiber conveying channel and a fiber guide surface; Maschinenfabrik Rieter AG, 8406 Winterthur.

Claims (13)

A method of making a yarn (70) from a fiber strand (1) in an air-spinning machine comprising: an outlet roller pair (2); a spinning box (5) for spinning a yarn (70) following in the spinning direction the pair of outfeed rollers (2), the spinning box (5) comprising: a swirl chamber (14.1) containing a spindle (7) having at least one air inlet opening (13.1, 61); a draw-off (63) containing a subsequent take-off roll (64) for carrying away the yarn (70), wherein a spinning tension F _{S is} exerted by the guiding away on the yarn (70); characterized by the process parameter: the spinning tension F _S has the following value range: F _S <20 cN. Method according to claim 1,
characterized by the further process parameter: the spinning speeds v _L have the following value range: v _L > 300 m / min. Method according to claim 1 or 2,
characterized in that
as a spin box element, a fiber conveying channel (4) with a fiber guiding surface (16) is provided, which is upstream of the vortex chamber and which has a deflection point (72), which causes a deflection of the fiber structure (1). Method according to one of claims 1 to 3,
characterized in that
as a spin box element, a fiber guide channel (4) with a tunnel lining (17, 26, 28) is preceded so that at the end of the fiber guide channel (4) a shoulder (18, 29, 31) is formed with an end face (20), so that the end face (20) serves as a guide surface for the air flowing in from the air inlet openings. Method according to claim 4,
characterized in that
the end face (20) is inclined by an angle of inclination β with respect to the spinning direction (19). Method according to claim 4 or 5,
characterized in that
the axis of the air inlet opening is inclined by an inclination angle α with respect to the spinning direction (19). Method according to claim 5 or 6,
characterized in that
the inclination angles α and β each have the following value ranges: 48 ° <= α <= 88 ° and 48 ° <= β <= 75 °. Method according to one of claims 4 to 7,
characterized in that
the tunnel lining (17, 26, 28) in the fiber guide channel (4) has a thickness a which lies in the following value range: 0.1 mm <= a <= 3 mm. Method according to one of claims 1 to 8,
characterized in that
as a spinning box element a fiber guide channel (4) is upstream of the vortex chamber (22) having at its end a Faserabgabekante (29), over the fibers in a substantially flat adjacent formation against the inlet mouth of the spindle (7) located Garnführungskanals (45). Method according to claim 9,
characterized in that
the air inlet openings are set so that the resulting vortex rear free fiber ends whose front ends are already in the yarn guide channel of the spindle, detected and rotated around the fiber structure. Method according to one of claims 1 to 10,
characterized in that
the spinning distortion S _V between outlet roller pair and take-off has the following value range: S V ≤ 1.0. Method according to one of claims 1 to 11,
characterized in that
the air flowing through the air inlet openings (13.1) into the vortex chamber (22) is supplied at a pressure p, the pressure p having the following value range:
3 bar <p <6 bar, preferably 4 bar <p <5 bar. Method according to one of claims 1 to 12,
characterized in that
the spinning tension F _{S is determined} according to the following formula: F S = 6.6 cN + 0.05 cN g m · (100 m G - nm + 0,0096 cN min m · ( v L - 350 m min ) in which
Nm is the metric number in [m / g] of the yarn to be spun (70) and v _{L is} the spinning speed in [m / min] and the spinning tension F _{S has} a range of ± 20%.

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