EP1747310A1

EP1747310A1 - Method for producing a yarn in a jet spinner

Info

Publication number: EP1747310A1
Application number: EP05714743A
Authority: EP
Inventors: Herbert Stalder; Peter Artzt; Heinz Müller; Kurt Ziegler
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2004-04-07
Filing date: 2005-04-07
Publication date: 2007-01-31
Also published as: CN1965115A; EP1584715A1; US20070277494A1; WO2005098103A1

Abstract

During a jet spinning method, the rotating fibre ends or the subsequent wound fibres of the spun yarn (70) cause a spinning tension FS. In tests, a direct correlation has been established between the spinning result and the spinning tension FS. The aim of the invention therefore is to provide a method for spinning yarn in a jet spinner that permits an ideal spinning tension FS despite high spinning speeds, thus achieving an optimal spinning result, in particular with regard to the yarn quality. According to the invention, a jet spinner is operated with a spinning tension FS < 20 cN by means of a configuration of spinning box elements.

Description

Method of making a yarn in an air spinning machine

The invention relates to a method for producing a yarn in an air spinning machine according to the preamble of claim 1.

The present invention relates to the field of air spinning machines. Air spinning machines have a large number of spinning positions. In each spinning station, a yarn is spun from a longitudinal fiber structure. The longitudinal fiber structure is first refined, which means that the amount of fibers per unit length is reduced by warping! Then the refined fiber structure is spun into a yarn in the spinning station. For this purpose, the spinning station has a fiber guide element which guides the fiber structure into a swirl chamber, where a yarn is produced on a spindle by the known vortex air spinning process.

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

For further explanation, reference is now made to FIG. 2. The spinning box 5 has a swirl chamber 10, in which the air flowing in through the air inlet opening 61 generates a swirl flow which turns edge fibers 62 located on the surface of the fiber assembly 1 and thereby spins the fiber assembly 1 into a yarn 70. The above-mentioned spinning tension Fs is mainly caused by the emergence of edge fibers 62 at the inlet mouth 9 of the spindle 7. These forces therefore have a special characteristic that is fundamentally different from the voltage characteristics of other processes, e.g. ring, rotor or two-nozzle spinning.

Confirmation opie Because in the air spinning process - an example of a corresponding machine can be found in the document EP 1 335 050 A2 [2] - essentially the rotating fiber ends or the later wrapping fibers of the spun yarn 70 cause the spinning tension F _s , there is a direct correlation between the spinning result - that means the yarn produced - and the effective, measurable spinning tension Fs. The properties of yarn quality and reliability of the spinning process are subsumed under the term spinning result. By reducing the spinning speed, the spinning tension can also be reduced to values that allow an improved spinning result. However, given the high spinning performance required with the required spinning speeds vι_> 300 m / min, this is not practical 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 approx. 45 ° around the Fasenterband 1 are spun into a yarn 70. Taking the air vortex into account, this angle is essentially determined by the spinning speed and this must therefore be in a normal range of around 300 m / min.

The present invention is therefore based on the object of specifying a method for spinning a yarn in an air spinning machine in which, despite high spinning speeds, an ideal spinning tension can be set, as a result of which 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.

The method parameter according to the invention, according to which the spinning tension Fs has a value range F _s <20 cN, creates a method which enables a spinning tension at high speeds, with which in particular high reliability is ensured, so that, for example, the risk of yarn breaks is greatly reduced , In order to achieve this target value range for the spinning tension F _s and thus optimize the spinning result, one or more of the following measures can be taken, for example: - Adjusting the spinning delay s between the drafting system outlet and the take-off rollers after the spinning box, so that s _v <1.0 , - Adjusting the compressed air pressure p of the air flowing into the swirl chamber to values from 3 to 6 bar, preferably from 4 to 5 bar. - Achievement of a strong suction effect by the air vortex generated in the vortex chamber to suck air from the gusset area after the outlet clamping line of the drafting system. There are various design options for this, which are described in the embodiments listed below. - Optimal design of the swirl chamber. There are also various constructive design options for this, which are also specified in the exemplary embodiments listed below.

Advantageous refinements of the invention are also specified in further dependent claims. , ; ^• : ^■ _ • '- ^{■' • ■}

The invention is explained in more detail below with reference to drawings, for example. Show:

Figure 1 Schematic representation of the components of an air spinning machine; Figure 2 Partial representation of a spinning box, in particular to explain the entry of a fiber structure in the spindle; Figure 3 fiber conveyor channel with a tunnel lining;

Figure 4 shows a more detailed representation of the paragraph of the tunnel lining and the air inlet opening in a first embodiment; Figure 5 shows a more detailed representation of the paragraph of the tunnel lining and the air inlet opening in a second embodiment; FIG. 6 shows a fiber guide surface having a deflection edge in a fiber guide channel;

FIG. 1 shows a schematic illustration of the components of an air spinning machine: With v _from ι and _a bz, the speeds occurring are shown, and with reference number 71 the location at which the process parameter spinning tension Fs relevant for this invention occurs.

FIG. 2 shows a spin box 5 in a detailed representation as it corresponds to the prior art and has already been explained in the introduction to the description.

FIG. 3 shows a first design within a spinning box 5, so that the desired spinning tension Fs is achieved. The spin box 5 has a fiber guide element 3 and then a spindle 7 with a yarn guide channel 8. The fiber guide element 3 is surrounded by a hollow cylindrical tunnel lining 17. The tunnel lining 17 can be made in one or more pieces. The fiber feed channel 4 is encased by the tunnel lining 17. The tunnel lining 17 is shaped such that a shoulder 18 to the swirl chamber housing 15 is formed at the end of the fiber conveying channel 4. The end face of the shoulder 18 serves as a guide surface for the fluid - normally - air emerging from the jet nozzles 13.1. The outlet openings of the jet nozzles for the fluid into the swirl 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 is also shown in the following FIGS. 4 and 5, the swirl chamber housing 15 does not necessarily have to include the fiber guide element 3 and its tunnel lining 17. The latter two elements can also have their own housing, which adjoins the swirl chamber housing 15 (see FIG. 5). A total of 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 angle of inclination is in the range of 45 ° to 88 °. In this first embodiment, the angle of inclination of the end face of the shoulder 18 to the material flow direction has the same amount. It is not difficult recognizable how the end face 20 of the fiber guiding element 3 adjoining the swirl chamber 14.1 has the same angle of inclination to the material flow direction 19 as the bores of the jet nozzles 13.1.

Figures 4 and 5 show two further embodiments for the sale of the tunnel lining, so that the desired spinning tension Fs is achieved. The swirl chamber housing 15 connects to a housing 32 for the fiber guide element 3 and the tunnel lining. The embodiment shown in FIG. 4 has a tunnel lining 26 which is shaped in such a way that at the end of the fiber conveyor channel 4, the shoulder 29 is formed with an angle of inclination β. The tunnel lining 26 preferably has a thickness a which lies in a range of values from 0.1 to 3 mm. The bore of the jet nozzle 13.1 is arranged in the swirl chamber housing 15 in the immediate vicinity of the end face of the shoulder 29. The shoulder 29 is arranged so close to the opening of the jet nozzle 13.1 that its front side serves as a guide surface for the emerging flow. The shoulder 29 is arranged in alignment with the bore, which in turn is arranged in alignment with the inner surface or lateral surface of the swirl chamber 14.1, so that the bore 13.1 runs "tangentially aligned" into the inside of the swirl chamber housing 15, or tangentially into the swirl chamber 14.1. However, angles of inclination α to the direction of material flow which lie in a value range from 60 ° to 70 ° are preferred. The angle of inclination β of the end face of the shoulder 29 can have a different value than the angle of inclination α. The most suitable angle of inclination ß can best be determined empirically for the specific application. Tests have shown that in most cases an angle of inclination β is suitable which has the same value as the angle of inclination. A configuration with a ≠ ß 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 is in a range of values from 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 according to the invention of the spinning tension F _s <20 cN. The fiber guide element 3c shown has a fiber guide tion 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, the intersection of which forms the deflection point 72. As a result of this configuration of the fiber guide surface 16, the fibers of the fiber structure 1 (not shown in FIG. 6) are guided in an essentially flat arrangement next to one another. A contribution to this flat arrangement is also made by the fiber delivery edge 6. The deflection point 72 is dimensioned such that the fibers of the fiber structure 1 are deflected in such a way 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 as well as the rear fiber ends, particularly those fibers that are on the surface of the fiber structure 1 or immediately below, are lifted off. Both the front and rear fiber ends are lifted off at the deflection point 72. By lifting fiber ends at the deflection point 72, the number of free fiber ends in the fiber structure increases. “Free fiber ends” are to be understood as those ends that are not within the staple fiber structure or are not connected to other fibers and can therefore be caught by the vortex flow. Increasing the number of free fiber ends increases the number of wrapping fibers in the yarn and the quality of the spinning process itself. This design of the fiber guiding surface surprisingly has a further advantage over the prior art. The reduction in cross section A of the fiber conveying channel 4: ^» within one area has shown that the air volume V flowing through was surprisingly increased. The increased amount of air V can significantly improve the fiber guidance between the outlet rollers and the entrance of the fiber guidance element 3c, that is to say in front of the fiber guidance element 3c. The number of interruptions in production caused by tearing of the fiber belt immediately after the outfeed rollers can thereby be reduced. A measurable improvement in yarn quality was also found. Tests have shown that particularly good results are achieved if the cross section A of the fiber conveyor channel 4 remains constant up to the deflection point 72 and the following cross section B of the fiber conveyor channel increases from the deflection point or additional edge 72. The area of the cross section A of the fiber conveying channel 4 to the deflection point 72 is preferably in a range of values from 0.5mm ² to 10 mm ² . Table 1 contains dimensions for the sizes C, D, E and F contained in FIG. 6, which enable a spinning tension Fs <20 cN.

Table 1: Dimensions for the embodiment according to FIG. 6

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

In a further embodiment of the present invention, a spinning delay S <1.0. Spinning delay Sv is defined using the following quotients: Sv: = gbz Vausl- where: v _az revolving speed of the take-off rollers; Vausi rotation speed of the outlet rollers.

The condition S <1.0 means that the peripheral speed of the take-off rollers 64 must at most be the same size as that of the outlet rollers 2 of the drafting device 69. It is therefore possible to obtain this condition because when spinning the fibers, the fiber structure easily loses length. Sv is preferably in the range from 0.96 to 1.0.

Another preferred embodiment of the invention has resulted from numerous spinning tests. In these spinning tests under different operating conditions (such as different spinning speeds and fineness of yarn), optimizing the elements of the spinning device and analyzes of the spun yarn quality, it was also surprisingly possible to find a relationship which, based on the operating conditions of spinning speed and fineness of yarn, specifies an optimal spinning tension Fs, ₀ ptimai:

where: F _{s> optimal} - optimal spinning tension in [cΝ] Νm = yarn count in metric number [m / g] v _L = yarn delivery speed in [rh / min]

This relationship is not a physical formula that inevitably results from the operation of the spinning station. Rather, this formula specifies the optimal spinning tension, which, due to the operating conditions, yarn delivery speed at the exit of the spinning machine and desired yarn fineness (so-called “metric number” of the spun yarn, in [m / g]) must be achieved by adapting various elements on the spinning machine In other words, you operate a spinning machine with a certain yarn delivery speed and you order an if the yarn count is correct (e.g. by adjusting the drafting system), this does not mean that this automatically results in a spinning tension in accordance with the above-mentioned relationship. So there will be a completely different effective spinning tension. F _s result. The yarn quality will also not be optimal. So what has to be done is to change the effective, measurable spinning tension Fs by various measures described in the previous pages so that their value corresponds to the amount of the optimal spinning tension F _s , _o pti _¬ m _a l calculated by the above formula , This results in a yarn of optimal quality.

The following table 2 contains in the middle column the optimal spinning tension Fs calculated from the metric number and spinning speed, optimal! The scatter values defined by ± 20% are given in the first two columns.

The teaching according to the invention can be implemented by freely combining and adapting the configuration of the spin box 5 and its spin box elements explained above in FIGS. 3 to 6, such as fiber leading edge 31, fiber delivery edge 29 or deflection point 72, as well as freely with the aforementioned operating parameters of pressure and spinning delay. By adapting the elements mentioned in the foregoing description and claimed below, it is possible to bring measurable spinning tension Fs to a value Fs <20 cN. In a preferred embodiment of the invention even includes the effective measurable spinning tension Fs to a value which _s, corresponds to the amount according to the above mentioned formula for F _o ptima _l.

List of reference numerals used in Figures 1 to 6

1 fiber, fiber dressing, staple fiber dressing

2 pair of outlet rollers; delivery rollers

3, 3c fiber guide element

4 fiber guide channel, fiber feed channel

5 spin box

7 spindle

8 yarn guide channel

9 Inlet mouth of the spindle 7

10 swirl chamber

11 inflowing air

12 drafting system

13 fluid device

13.1 Jet nozzles

14 room

14.1 vortex chamber

15 swirl chamber housing

16 fiber guide surface, flat fiber guide surface

17 tunnel lining

17.1 Half-shell of the tunnel lining 8 paragraph 9 material flow direction, transport direction 0 end face of the fiber guide element 3 in the swirl chamber 3 center line of the yarn guide channel 6 tunnel lining 8 tunnel lining 9 paragraph with inclination angle ß 1 paragraph 2 housing for fiber guide element and tunnel lining 0 spinning station 1 inlet opening air flow 2 edge fibers 3 take-off 4 take-off rollers 5 friction roller

66 thread monitors

67 Thread laying device 8 thread spool

69 drafting system

70 yarn

71 Place where the spinning tension occurs and is measurable

72 deflection point

List of reference numerals used in Figure 7

20 nozzle block 21 jet nozzles

22 whirl chamber vent channel

Direction of air intake

Fiber conveying channel

Fiber conveying element

Fiber guide surface

Fiber delivery edge

face

Fiber take-up edge

spindle

Cone of fiber conveying element 27

Support element for fiber conveying element 27

Center line of jet nozzles 21 and blowing direction

Fiber conveying roller

yarn guide

center line

List of symbols used

Vabz rotation speed of the take-off rollers

Vausi rotation speed of the outlet rollers α angle of inclination of the jet nozzles to the fiber or material transport direction ß angle of inclination of the shoulder 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 the deflection point

B Cross section after the deflection point C Distance parallel to the center line 23 from the deflection point 72 to the fiber delivery edge 6

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

E Distance parallel to the center line 23 from the fiber delivery edge 72 to the inlet mouth 9 of the spindle 7

Fs spinning tension in [cN]

Fs.optimai optimal spinning tension in [cN], according to the formula

F distance vertically to the center line 23 from the fiber delivery karite 72 to the center line 23 of the thread guide channel 8 G width of the reduced fiber delivery edge 6

Nm metric number in [m / g], length per mass; Hit in [1] p pressure in [bar]

S _v spinning delay _v spinning speeds in m / min List of abbreviations used

ISO International Standard Organization

List of units used Bar pressure; ISO Unit

N, cN Newton, Centi-Newton; ISO unit of measurement m meters; ISO unit of measure min minute

literature sources

[1] Expertise clothing, 5th edition ISBN 3-8085-6205-6; 1998 Verlag 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

claims

1. A method for producing a yarn (70) from a fiber structure (1) in an air spinning machine, which contains: - a pair of outlet rollers (2); - A spin box (5) following the pair of outlet rollers (2) for spinning a yarn (70) in the spinning direction, the spin box (5) containing: a swirl chamber (14.1) containing a spindle (7) and containing at least one air inlet opening (13.1, 61) ; - a subsequent take-off roller (64) containing take-off (63) for taking away the yarn (70), a spinning tension Fs being exerted by the taking away on the yarn (70); g e ke n e i ch n et d u rch e n pro cedure s p a ra m eter: - the spinning tension Fs has the following range of values: Fs <20 cN.

2. The method according to claim 1, characterized by the further process parameter: - The spinning speeds v__ has the following range of values: VL> 300 m / min.

3. The method according to claim 1 or 2, characterized in that a fiber conveyor channel (4) with a fiber guide surface (16) is provided as a spin box element, which is located in front of the swirl chamber and which has a deflection point (72) which deflects the fiber structure ( 1) caused.

, Method according to one of Claims 1 to 3, characterized in that a fiber guide channel (4) with a tunnel lining (17, 26, 28) is placed in front as a spin box element in such a way that 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.

5. The method according to claim 4, characterized in that the end face (20) is inclined by an angle of inclination β relative to the spinning direction (19).

6. The method according to claim 4 or 5, characterized in that the axis of the air inlet opening is inclined by an angle of inclination α with respect to the spinning direction (19).

7. The 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 °.

8. The method according to any 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 range of values: 0.1 mm <= a <= 3 mm.

9. The method according to any one of claims 1 to 8, characterized in that as a spin box element, a fiber guide channel (4) of the swirl chamber (22) is arranged in front, which has a fiber delivery edge (29) at its end, over the fibers in a substantially flat side-by-side formation against the inlet mouth of the yarn guide channel (45) located in the spindle (7).

10. The method according to claim 9, characterized in that the air inlet openings are set so that the resulting vortex rear free fiber ends, the front ends of which are already in the yarn guide channel of the spindle, detected and rotated around the fiber belt.

11. The method according to any one of claims 1 to 10, characterized in that the spinning delay Sv between the pair of discharge rollers and the take-off has the following range of values: S _v <1.0.

12. The method according to any one of claims 1 to 11, characterized in that the air flowing through the air inlet openings (13.1) into the swirl chamber (22) is supplied at a pressure p, the pressure p having the following range of values: 3 bar <p < 6 bar, preferably 4 bar <p <5 bar.

3. The method according to any one of claims 1 to 12, characterized in that the effective spinning tension Fs has a value which amounts ± 20% of the optimal spinning tension F _s , opti _m al according to the following formula corresponds to F _{s optimal} = 6.6 cN + 0.05? ^ A - {100 - - Nm) + 0.0096 ^ - {v _L - 350 -) ^{, μ} mgm mm where Nm is the metric number in [m / g] of the yarn to be spun (70) and v _{L represents} the spinning speed in [m / min].