WO2007025535A2

WO2007025535A2 - Drafting system for fabricating fibrous material

Info

Publication number: WO2007025535A2
Application number: PCT/DE2006/001535
Authority: WO
Inventors: Reinhard KÖNIG; Georg KÖNIG
Original assignee: Koenig Reinhard; Koenig Georg
Priority date: 2005-08-30
Filing date: 2006-08-30
Publication date: 2007-03-08
Also published as: EP1920091A2; DE112005003744A5; WO2007025490A1; WO2007025535A3; PL1920091T3; EP1920091B8; ES2529177T3; EP1920091B1

Abstract

The invention relates to a drafting system, particularly a high-capacity drafting system for fabricating staple fibers. In order to keep clean and prevent unwanted linters, filler pieces (17, 18) are provided preferably between all upper and lower rollers (3a to 6a; 3b to 6b), these filler pieces forming a conveying channel (17a, 18a) the shields the fibrous material (2). In addition, a flow channel (10, 11) is effectively assigned to the upper and lower rollers (3a to 6a; 3b to 6b), and an air flow, which is parallel to the fibrous material (2) and preferably directed counter to the direction of conveyance (1) of the fibrous material (2) is led through the flow channel in order to lead away a somewhat resulting fiber/air mixture.

Description

Drafting system for processing fiber material

The invention relates to a drafting system of the preamble of claim 1 specified genus.

Drafting systems for processing fiber material are generally designed as 3- or 4-roller drafting systems that work with straps in the main draft zones. They can od with various components such as compressors, mechanical twist tubes od in the draft zones. Like. Be provided, the straps can be connected for the purpose of compaction to suction sources. The lower rollers of the drafting systems are usually provided with straight or oblique corrugations, which ensure good clamping of the fiber material in the nips of the pairs of rollers, while the upper rollers usually have rubber pads.

To avoid the flight, d. H. the pollution and clogging of the drafting system by emerging from the fiber material fibers, and the re-entry of these fibers in the fiber material, cleaning or cleaning devices are known which have blowing and suction devices, which are movable and at intervals blowing or suction currents to the Rolling the drafting systems bring.

At this level of the drafting technique, various criticisms arise.

In the development of faster-moving, classic and unconventional spinning processes, the focus was first on the function of yarn formation. One believed to be able to get along with the classic drafting systems.

The working speeds experienced a huge increase. While the classic ring spinning process with delivery speeds of the output roller pair runs around 20 m / min, the delivery speed is around 80 m / min for centrifugal spinning, around 250 m / min for spinning / knitting, around 500 m / min for air-spinning and for friction spinning up to 700 m / min. This increase in the delivery speed, which has to provide a drafting, can not be achieved solely by the fact that without accompanying measures simply the speed of the various pairs of rollers is increased. So-called "dirt effects" grow with increasing operating speed to serious problems that can make an industrial use impossible. Among such "dirt effects", which may also be referred to as 2nd order effects, the following phenomena are understood:

The Verflugung increases very strongly, because accumulate at the different parts of fibers, which then wander uncontrollably in the drafting system, connect with the normal flowing flow of material and thus sporadically lead to severe delays.

The air flow inside and around a drafting system is not clearly defined, i. H. There are dead angles, edges, screws, etc., which lead to winding formations.

The air movement in the immediate vicinity of the stretch

Works organs such as rollers and aprons lead at high operating speeds to splitting of material or to uncontrollably stirred up fibers and fluff or the like, which are also referred to as "braids", "pilots" and "bales".

The known cleaning devices in the form of blowing and suction devices are only a poorly matched system, which also does not work constantly (Wanderbläser) or consumes too much energy and thus makes the overall process more expensive. This also applies to a known drafting arrangement of the type described in the beginning [Patent Abstracts of Japan, Vol. 007, No. 225 (C-189), October 6, 1983], in which all existing pairs of rolls are enveloped by a substantially closed housing. The housing has in each case an entrance slit and an exit slit for the fiber material to be processed and an exit to a suction source. Ie connected connection piece on. Within the housing a number of nozzles corresponding to the number of nozzles is arranged, wherein each nozzle of a lower or upper roller is associated with a small distance so that it emits an air stream which is perpendicular to the formed by the nips of the pairs of rollers conveyor track for the Fiber material is directed and perpendicular to the

Peripheral surface of the respective roller impinges. A resulting problem is that uncontrolled air currents arise and these fibers can easily get back into the fiber stream and / or one of the nips, resulting in fiber clumping and thick areas in the fiber material, an irregular distortion of the fiber material and a stoppage of the drafting system can cause due to blockages.

Drawbars of this type are therefore not suitable for high-performance drafting, as z. B. for the processing of short staple fibers at the highest distortion and operating speeds and z. B. for the above centrifuges, air,

Friction and spinning / knitting process are needed, which work without exceptions with working speeds far above the ring spinning.

Based on this, the invention has the task of the drafting of the type described initially in such a way that it allows a controlled air flow to the drafting around an accumulation of fibers, fluff, flakes od. Like. (= Approachers and Batzen) largely avoids thereby performing a faulty delay work and can be used not only as a slow-running drafting system on a ring spinning machine, but in particular as a high-performance drafting for the purposes specified above.

To solve this problem, the characterizing features of claim 1.

The drafting system according to the invention is z. B. to a 4-roller drafting system for strip processing without compaction with three delay zones, which - viewed in material direction - as Vorverzugszone, Anspannverzugszone and Main delay zone can be called. The fillers located in the interstices of the lower and upper rolls of at least selected pairs of rolls shield the fiber material from flying fibers, fluff or the like. In addition, flow channels are preferably provided above and below the corresponding upper or lower rollers, which lead to a steady, parallel to the conveyor track and preferably directed against the material direction of air flow, are useful with respect to the environment under a slight negative pressure and serve the purpose od od flying fibers or the like.

On the input side, a protective tube, also called a trocar, preferably leads the fiber material to the input rollers. Thus, the material flow is sufficiently shielded on the input side of the air currents.

In the Anspannverzugszone is expediently an open compressor, which compresses the material flow to about 10 mm when conventional tapes are presented. In the main draft zone, there may be another open compressor which slightly further densifies the fiber stream of 10 mm width coming from the tension draft zone.

The finished stretched fiber material passes through the output rollers z. B. to an associated spinning system.

In addition, the output lower roller may be associated with a conventional, technologically induced suction.

The three top rollers, seen in the material direction, are located on a common pressure arm. The output top roller is preferably mounted separately and axially iridescent.

In the main draft zone, a turbulence brake can be located on each of the upper and / or lower rollers. It is a knife-like structure that at the roller in question or is set to the narrowest gap.

The drafting system according to the invention can also be designed as a drafting system for strip processing with compaction. In this case, preferably there is a 5-roller drafting system with an additional compaction zone. In this case, the compaction can be effected by a spinning nozzle with spinning tube. In the spinneret of the known type, an air vortex is spun, which spins the material into a "temporary yarn". At the end of the spinning tube and immediately before the subsequent pair of rolls, the rotations of the temporary yarn dissolve because of the false-twist effect, and only parallel but perfectly compacted fibers enter the clamping region. The output rollers can now follow a spinning device of known type.

When processing very short-staple belts, the drafting system is modified, regardless of the number of pairs of rollers present, in a particular embodiment, at the input top roller of the main drafting zone. The input upper roller carries for this purpose a Riemchenkäfig, which carries a circumferential, air-permeable straps known type. The strap is placed around rotatably mounted pins od. Like. And is covered by an internal suction box. The suction box preferably has an opening which tapers in the material running direction from about 10 mm to about 5 mm. This modification is mainly not for compacting, but for improving the shrinkage of short fibers into the exit rollers by increasing the retention force. If an effective compaction take place, then a z. B. formed by a spin tube compaction zone, as described above, appended.

The strap expediently has a gap to a cover located above it, which just touches the flow of material without squeezing it.

Further advantageous features of the invention will become apparent from the dependent claims.

The invention will be described below in conjunction with the attached chen standards held drawings of exemplary embodiments explained in more detail. Show it:

1 shows a longitudinal section through an inventive drafting system with four pairs of rollers for the processing of strip material.

Figures 2 and 3 are sections along the lines II-II and HI-III of Fig. 1;

FIG. 4 shows a section corresponding to FIG. 2 through a drafting system which is suitable especially for spinning / knitting machines; FIG.

5 shows a perspective view of a compressor suitable for the drafting systems according to FIGS. 1 to 4;

6 shows a schematic cross section through a turbulence brake suitable for the drafting systems according to FIGS. 1 to 4;

7 is a schematic cross-section through a main drafting zone for the drafting systems according to FIGS. 1 to 4 intended for processing extremely short-staple fiber material;

8 shows a section through the main drafting zone along the line VIII-VIII of Fig. 7.

Figure 9 is a longitudinal section through a drafting system with five pairs of rollers and a compacting device having a spinneret and an adjoining spinning tube. and

10 to 12 Details of the spinneret of FIG. 9 in a respective longitudinal section, a front view and a longitudinal section corresponding to FIG. 10, but after rotation of the spinneret by 90 ° about its longitudinal axis. Fig. 1 shows first a conventional 4-roller drafting system, through which a band-shaped fiber material 2 is passed in a direction indicated by arrows 1 conveying direction. The drafting system has four in the conveying direction 1 one behind the other, usually driven at different peripheral speeds pairs of rollers, each having a lower roller 3a, 4a, 5a and 6a and a top roller 3b, 4b, 5b and 6b. The rollers 3a, 3b form a first or pair of input rollers and the rollers 6a, 6b a fourth or pair of output rollers, while the rollers 4a, 4b and 5a, 5b form middle roller pairs or a second and third roller pair.

All pairs of rollers define customary clamping lines between them. In addition, the roller pairs 3a, 3b and 4a, 4b form a Vorverzugszone VV, wherein the peripheral speeds of the rollers are selected so that a comparatively low distortion of the fiber material 2 is obtained. Further, the pairs of rollers 4a, 4b and 5a, 5b operated at such peripheral speeds that between them a Anspann- delay zone AV arises, in which the delay is just sufficient to keep the fiber material 2 stretched. Finally, between the rollers 5a, 5b and 6a, 6b, a main draft zone HV is provided, which is why the peripheral speeds of these rollers are chosen so that an extension of the fiber material 2 z. B. by 50 times or more.

The upper rollers 3b, 4b and 5b are rotatably mounted as shown in FIG. 1 on a schematically indicated pressure arm 7, the od with a bearing shaft 8 to a stationary frame. Like. Is pivotally mounted and in the direction of a double arrow v by means of a force, for. As a spring force, can be biased to press the upper rollers 3b, 4b and 5b against the associated lower rollers 3a, 4a and 5a.

The storage and the drive of the rollers 3a, 3b to 5a, 5b can be carried out in the usual way. This z. B. the lower rollers 3a, 4a and 5a driven by means of mounted on their shafts drive gears, while the upper rollers 3b, 4b and 5b are taken by friction of the associated lower rollers 3a, 4a and 5a. In a preferred exemplary embodiment, furthermore, the upper roller 6b of the pair of output rollers is mounted separately and pivotably and alternately in the axial direction, as indicated schematically in FIG. 1 by a bearing 9 and arrows w and x. Due to the iridescent storage, a preservation of the rubber supports and extension of the service life of this particularly heavy-wearing roller 6b are achieved. To further extend the service life of the output top roller 6b may be given a much larger diameter than the other rollers.

Draw frames of the type described are generally known and therefore need not be explained in greater detail to the person skilled in the art.

According to the invention, the drafting system according to FIG. 1 has a device which serves for keeping clean and for avoiding unwanted fiber fly in the region of at least one selected roller pair. The selected pair of rollers is preferably that pair of rollers whose rollers are driven at the greatest peripheral speed and therefore contribute particularly strongly to the formation of fiber fly and the like, as is the case in Figure 1 for the pair of outfeed rollers with rollers 6a and 6b. According to a presently considered best embodiment, this device is designed as follows.

On both sides of the conveyor track on which the fiber material 2 is passed through the drafting system, at least one respective flow channel 10 and 11 is provided which is parallel to the conveyor track or to the conveying direction 1 and which is on the side facing away from the conveyor track, ie outwardly, by covers 12 and 14 is limited. In this case, the covers 12 on the side of the lower rollers 3a to 6a are suitably fixed to a stationary part of the drafting system, while the covers 14 on the side of the upper rollers 3b to 6b are preferably connected to the pressure arm 7 so as to be pivoted outwardly therewith can. Inwards, ie towards the conveyor track, the flow channels 10, 11 extend to the lower and upper rollers 3a to 6a and 3b to 6b, respectively. Each flow channel 10, 11 is associated with at least one, only schematically indicated blowing nozzle 15, 16, the so is arranged to generate an air flow which flows through the flow channels 10, 11 substantially parallel to the conveyor track and tangential to the rollers 6a, 6b at least of the selected pair of rollers.

In the exemplary embodiment, the flow channels 10, 11 with particular advantage of the output rollers 6a, 6b extends to the input rollers 3a, 3b, so that all existing rollers 3 a to 6b are detected by the air streams. In this case, the blowing nozzles 14, 15 are each arranged on a downstream in the conveying direction behind the pair of output rollers 6a, 6b in the region of inlet sections to the flow channels 10, 11, while in the conveying direction 1 in front of the inlet rollers 3a, 3b outlet sections of the flow channels 10, 11 at an indicated by an arrow y suction or vacuum source are connected. This has proven to be the best solution, since the air flows in this way substantially parallel and opposite to the conveying direction 1 through the flow channels 10, 11 flow, without vortex and thereby be deflected in the direction of the conveyor track. In addition, it has proved to be particularly advantageous to arrange the blowing nozzles 15, 16 so that the air streams at locations on outer peripheral surfaces of at least the rolls of the selected pair, d. H. Here, the rollers 6a, 6b impinge, which are below outer vertexes 6Sl and 6S2, d. H. lie between them and the conveyor track, as Fig. 1 clearly shows.

In order that the fibers entrained by the air streams and the like. Virtually no way to get back into the transported in the conveying direction 1 fiber material 2, the flow channels 10, 11 in the previously held for best embodiment on its inner, the conveyor track facing sides through limited to the lower and upper rollers 3a to 6b patches or covers 17 and 18. The patches 17, 18 have an arbitrary shape in themselves, but are provided in the embodiment on their rollers 3a to 6b facing sides with adapted to their peripheral surfaces, concave curved portions. This results between the rollers 3a to 6b and the filler pieces 17, 18 narrow column 19, which carried a reentry of in the air streams Make fibers in the Faseπnaterial 2 practically impossible. In addition, the patches extend 17, 18 perpendicular to the conveyor track to such a height, they, as shown in FIG. 1, together with the outer peripheral surfaces of the rollers 3a to 6b form almost a plane and therefore no cause for turbulence or other disorders in to provide the air streams. The air currents therefore pass practically only tangentially the circumferential surfaces of the various rollers that project only slightly into the flow channels 10, 11.

The air streams are preferably at an overpressure of z. B. generates about 150 mm of water to the environment, while at the same time the suction source (arrow y) ensures that in the flow channels 10, 11 creates a slight negative pressure to the environment. Overall, the air flows and the negative pressure are preferably chosen so that flows out of the nozzles 15, 16 air at high speed and low air flow to the resulting fiber / air mixture quickly and effectively from the rollers 3a to 6b, in particular the fast-running output rollers 6a, 6b lead away. An overpressure of about 150 mm of WS has proven to be sufficient for this purpose.

As further shown in FIG. 1, one of the two flow channels, in this case the flow channel 11, crosses the conveying path at a location in the conveying direction 1 in front of the pair of inlet rollers. In order to protect the fiber material 2 at this point from the air flow in the flow channel 11, it is preferably supplied by means of a respective flow channel 11 projecting through, also referred to as a trocar protective tube 20, which can extend into the gusset between the input rollers 3a, 3b , To avoid disturbances in the air flow should

Protective tube 20 also has a streamlined shape, z. B. have a smooth, streamlined cross-section. Alternatively, it would of course also be possible to connect the flow channel 11 to a separate suction source, so that he does not have to cross the fiber flow. The fibrous material 2 is protected in this case by lateral coverings of the flow channels 10, 11 from the air streams and the fibers entrained therein. In a corresponding modification of the exemplary embodiment according to FIG. 1, it is possible to expose only the rolls of a selected pair of rolls to the air streams, for. B. the fastest-running pair of output rollers 6a and 6b. In this case, the flow channels 10, 11 could end at points located between the rollers 5a, 6a and 5b, 6b and be led outwards. Other air ducts are possible, for. For example, those that only detect the two fastest-running pairs of rollers 5a, 5b and 6a, 6b. In this case as well, the rolls which have flowed first are expediently flown in each case below the vertexes, as indicated in FIG. 1 by the vertices 6S1 and 6S2. The number of pairs of rollers to be detected in each case by the flow channels depends largely on the respective conditions.

As shown in Fig. 2, drafting systems are often designed in tandem construction and provided with at least two adjacent drafting sections and conveyor tracks for conveying two juxtaposed fiber streams. As shown in Fig. 2 in cross-section, two of the conveyor paths are formed inter alia by two laterally adjacent, provided with corrugated Unifangsflächen bottom rollers 4al, 4a2 and top rollers 4b 1, 4b2, the two bottom rollers 4al, 4a2 mostly on a single, 4, while the upper rollers 4b 1, 4b2 are arranged individually and axially spaced from each other, but connected together by an axle 21 to which the pressure arm 7 is fixed. For the remaining, not visible in Fig. 2 lower and upper rollers a corresponding arrangement is provided. In this case, it is expedient according to the invention to provide each of the two drafting unit sections with the above-described flow channels and blowing nozzles. Therefore, the one stretched plant section z. B. flow channels 10a and IIa, the other drafting section, however, flow channels 10b and IIb. These flow channels 10a, 10b and IIa, 11b are preferably produced by attaching or being attached to the continuously formed outer covers 12 and 14, each transverse to the conveyor tracks and arranged at the two end faces of the respective rollers partitions 22 and 23 respectively which reach close to the relevant conveyor tracks. chen. In this case, the partitions 22 are suitably stationary, the partitions 23, however, attached to the covers 14 and together with these or separately therefrom on the pressure arm 7 and pivotally mounted therewith. Through the partition walls 22, 23 arise between the adjacent rollers 4a 1, 4a2 and 4b 1, 4b2 Freiräu- me 24 a and 24 b, the z. B. according to FIG. 2 facilitate the attachment of the pressure arm 7 and are not traversed by compressed air. The covers 12, 14 and the partitions 22, 23 are preferably streamlined as in the case of Fig. 1 and formed so that they have no corners and projections on which fibers, flakes od. Like. Adhere and can accumulate. In addition, on the side of the top rollers 4bl, 4b2 several covers 14 may be present, between which the pressure arm 7 is arranged, as Fig. 2 reveals.

Laterally next to the pairs of rollers 4al, 4bl and 4a2, 4b2, as in conventional drafting systems for spinning machines, more tandem roller pairs formed in tandem construction can be provided. This is indicated in Fig. 2 by pairs of rollers 4cl, 4dl and 4c2, 4d2, which are associated with corresponding flow channels. The different pairs of rollers follow each other at pitches T, whereby od between the various tandem arrangements sufficiently large spaces for required yarn packages. The like. Arise.

Fig. 3 shows the drafting arrangement according to FIGS. 1 and 2 in a section placed through the filling pieces 17 and 18 (section line III-III of FIG. 1). It can be seen that both the filling pieces 17 belonging to the lower rolls and the filler pieces 18 belonging to the upper rolls are brought close to the conveying path for the fiber material 2 to be processed. As a result, the patches 17, 18 cover the

Fiber material in located between the roller pairs areas optimally against the flow channels 10a, 10b and IIa, IIb. To provide the patches 17, 18 as shown in FIG. 3 on their sides facing each other in the conveying direction recesses, grooves od. Like., To thereby even better against the flow channels 10 a to II b shielded transport channel 17 a, 18 a for to create the fiber material 2. 4 shows a drafting system which also has more than two adjacent conveyor tracks and is preferably used, for example, in spinning / knitting machines (eg PCT WO 2004/079068). A bottom roller shaft (eg 4) common to all drafting sections along which a plurality of bottom rollers 4cl, 4al, 4a2, 4c2, etc. are arranged as shown in Fig. 2 is a plurality of top rollers 4dl connected in tandem construction , 4b 1, 4b2 and 4d2 assigned, so that together with the other, not visible in Fig. 4 and correspondingly formed lower and upper rollers a plurality of conveyor tracks formed. Two upper rollers each (eg 4b 1 and 4b2) form, analogously to FIG. 2, a pair of upper rollers, wherein an axial distance A between the various upper roller pairs is considerably less slanted than in FIG. 2 in order to reduce the required installation space. Due to the lack of yarn packages od. Like. This distance A can be kept very small, in contrast to other purposes serving drafting. As a result, here it is possible to provide individual flow channels 10c and 10d, etc., on the side of the lower rollers, which are formed as in FIG. 2 by the cover 12 and partitions 22, but extend axially over regions which each consist of two facing upper rollers adjacent pairs of rollers and the two associated lower rollers are taken. This is z. B. the flow channel 10c associated with the lower rollers 4cl and 4al. Accordingly, on the side of the associated upper rollers 4dl and 4bl or 4b2, 4d2 z. B. each flow channels 11c, Hd, etc. may be provided, which, as shown in Fig. 2 on both sides of pressure arms 7a, 7b, 7c, etc. by the transverse to the conveyor tracks extending partitions 23, on the other hand by parallel to the conveyor tracks extending covers 14a, 14b , 14c, 14d, etc. are limited. In each case, two covers (eg 14a and 14b), which are fastened to adjacent pressure arms (eg 7a, 7b) and are separated by narrow gaps (eg 14a and 14b), are involved in the formation of such a flow channel (eg llc) to allow independent pivoting of the different pressure arms 7a to 7c,

Overall, it is achieved by the construction of Fig. 4, that between the individual tandem arrangements pitch distances t <^ T can be provided. Moreover, it is expedient in the embodiments of FIGS. 2 to 4, the flow channels 10a, IIa, etc. of the output rollers to the input rollers continuously form to od side connecting piece for the suction sources. Like. To avoid space reasons.

Further preferred details of the drafting arrangements described are explained in more detail below with reference to FIGS. 5 to 12.

Fig. 5 shows an open compressor 26, which in a delay zone formed between two pairs of rollers, in particular z. B. in the Anspannverzugszone AV (Fig. 1) may be arranged. The compressor 26 is traversed by the indicated in Fig. 5 by an arrow fiber material 2 and has at its output the narrowest point with a jaw width of z. B. about 10 mm. A corresponding compressor 26 can be arranged in the main drafting zone HV (FIG. 1) in order to further densify the fiber material 2, and at its narrowest point have for example a jaw width between 5 mm and 10 mm.

Fig. 6 shows a turbulence brake 27, the z. B. in the immediate vicinity of the output rollers 6a, 6b at the end of the main drafting zone HV is arranged. The task of the turbulence brake 27 is to protect the nip gaps formed between the roller pairs before the entry of circulating air flows and in these entrained fibers. The turbulence brake 27 has z. B. the rollers 6a, 6b associated, arranged on the sides of the associated filler pieces 17, 18 cover elements 28a and 28b with ends 29a and 29b, the peripheral surfaces of these rollers 6a, 6b abradingly abut on the inlet side to the nip (roller 6b) or this with a small distance (roller 6a) are opposite. The rollers 6a, 6b provided with the cover elements 28a, 28b preferably have smooth surfaces. This avoids sparking and noise that would be unavoidable in combination with corrugated rolls. Other rollers of the drafting system can be provided with such turbulence brakes 27. In Fig. 1, the turbulence brakes 27, which are indicated by thick black lines, in Arranged portion of the output roller pair, because the output rollers 6a, 6b z. B. can rotate at speeds up to 7000 rpm. The resulting high circumferential velocities make it useful to use the described turbulence brakes 27, as these prevent in particular that generated by the rolling surfaces, circumferential, counter-rotating air flows in the gusset of the respective pair of rollers and laterally flow under strong turbulence from the gusset. These strong turbulences would possibly entrain fibers from the main material flow and lead to a deterioration of the quality of the process and ultimately of the fiber composite emerging from the drafting system.

Alternatively, it would be possible to combine the turbulence brakes 27 with the filler pieces 17, 18 and to form their ends facing the rolls corresponding to FIG. 6.

Another preferred feature of the drafting systems according to the invention consists of a in Fig. 7 and 8 shown Riemchenkäfig 30, the z. B. the top roller 5b is assigned, which is located at the entrance to the main drafting zone HV. The Riemchenkäfig 30 includes a strap 31, on the one hand on the upper roller 5b, on the other hand to reduce the friction on a rotatably mounted, a comparatively small diameter shaft 32 runs, which is close to the Eingangszwickel the output roller pair 6a, 6b. The apron 31 is permeable to air and guided between the rollers 5b, 6b via a suction box 33, which is close to the fiber material 2 and lies at a suction source. As shown in FIG. 7, the suction box 33 has an opening 34 which is overflowed by the fiber stream 2 and has a width b (FIG. 8) which decreases in the conveying direction. B. 5 mm. As a result, although a certain compaction of the fiber material 2 is achieved. Above all, however, especially when processing fiber materials 2 with a high proportion of short fibers, it is ensured that the short fibers are retained by the apron 31 and are not unintentionally entrained by the following pair of rollers (here 6a, 6b), which would prevent a uniform distortion , To achieve only this effect, the opening 34 could also be a round, four- have square or otherwise shaped peripheral contour. If a correct compaction is to be achieved, a compacting device described below is preferably provided.

At the side of the conveyor track facing away from the suction box 33, the apron cage 30 preferably has a plate 35 which can simultaneously form one of the filling pieces 17 (FIG. 1) and which is tightly opposite the fiber material 2 or lies on or contacts the fiber material 2, without squeezing it. As a result, the efficiency of the suction box 33 operated with a suitable negative pressure is increased.

The suction box 33 and the plate 35 may, analogously to FIG. 6, also be designed simultaneously as turbulence brakes, as indicated in FIG. 7 by their ends 33a, 35a corresponding to the ends 29a, 29b of the cover elements 28a, 28b in FIG ,

FIGS. 9 to 12 show details of a compacting device which extends the drafting device described with reference to FIG. 1 about a compaction zone K arranged in the conveying direction 1 behind the pair of output rollers 6a, 6b. In this case, the same reference numerals as in Fig. 1 are provided in Fig. 9 with the same parts. While the delays in the zones VV, AV and HV are in the usual order of magnitude, the delay within the compaction zone K is set to zero or virtually zero.

According to FIG. 9, in the compaction zone K there is a spinning device 36 with a spinneret 36a and a spinning tube 36b adjoining it. The spinneret 36a sucks the fiber material 2 exiting from the exit rollers 6a, 6b and forms from it a temporary ring yarn which extends to the end of the spinning tube 36b. The entire system is a false twist device, which is why in a following on the spinning tube 36b, consist of rollers 37a, 37b pair of rollers only parallel fibers and the rotations between the end of the spinning tube 36b and the rollers 37a, 37b are completely degraded. The from the However, fiber material 2 formed material flow is perfectly compacted. The rollers 37a, 37b may be followed by a spinning system of known type.

A preferred exemplary embodiment of the spinneret 36a is shown in FIGS. 10 to 12. Thereafter, the spinneret 36a is formed on its input side as a funnel having a substantially oval or flat oval inlet opening 38a and a z. B. circular outlet opening 38b has. The inlet opening 38a is preferably arranged in the output gusset of the output roller pair 6a, 6b and has a width B (FIG. 11) which preferably corresponds at least to the width of the fiber material 2 exiting from this pair of output rollers 6a, 6b so that no fibers can escape laterally therefrom , H. no fiber loss occurs and all fibers occurring are incorporated into the temporary yarn. By contrast, the height of the inlet opening 38a measured perpendicular to the width B can be comparatively small in accordance with the usual thickness of a sliver. Finally, the exit orifice 38b has a diameter D (Figure 11) such that the ratio B: D z. B. 5: 1 and the fiber material 2 is already compacted through the hopper. In particular, the dimension D z. B. about 2 mm and the dimension B z. B. be about 5 mm to 10 mm.

Otherwise, the spinneret 36a z. B. provided with at least one nozzle 36 c, which at an angle of z. B. is arranged at 90 ° to the conveying direction and Spinnrohrachse, serves in a known manner to produce air vortices and are connected to a compressed air source, not shown, the compressed air with an overpressure of z. B. 0.2 bar to 0.4 bar supplies. The compressed air draws the fiber material 2 exiting the output roller pair 6a, 6b into the spinneret 36a and at the same time conveys it through the subsequent spinning tube 36b in the direction of the roller pair 37a and 37b (FIG. 9). As a result, on the one hand the fiber material in the spinning tube 36a is given a multiplicity of revolutions, as indicated schematically in FIG. 12 by a wavy line 40. On the other hand, a high compaction is achieved, which also in the area between the spinning tube 36b and the subsequent pair of rollers 37a and 37b, in which the rotations completely dissolve again (False-twist effect), essentially preserved. The thus-compressed fiber material 2 can then be fed to a spinning machine, a spinning / knitting machine or the like.

Moreover, the rollers 37a, 37b are provided with particular advantage analogous to FIGS. 1 and 5 with turbulence brakes 27. The top roller 37b is attached as usual to a pressure arm 41 and preferably mounted axially iridescent. It is also particularly advantageous if the flow channels 10 and 11 described with reference to FIG. 1 as shown in FIG. 9 are extended to the rollers 37a, 37b of the further pair of rollers. In this case, the fast-rotating pair of rollers 37a, 37b is preferably also a selected pair of rollers, to which are associated with the blowing nozzles 15, 16 analogue nozzles 42a, 42b. Moreover, the drafting device is designed as in Fig. 1, which is why the same parts are provided with the same reference numerals.

The loads of the upper rollers 3b to 6b and 37b move in the usual orders of magnitude. However, the top rollers 5b and 6b can also be loaded much less than is usual in ring spinning, which extends the service life. This is especially true when the spinning tension of the subsequent spinning system caused by true rotations does not exceed 0.2 N (eg in air spinning or spinning / knitting).

A particularly significant advantage of the drafting devices according to the invention described is that the material streams formed from the fiber material 2 are largely separated from the flow channels 10, 11 serving the detuning, in particular if additionally the filling pieces 17, 18 used and the walls of the

Flow channels are consistently smooth and formed so that no dead zones od. Like. Result. A preferred streamlined, ie streamlined or a small flow resistance formation of the inner walls of the flow channels 10, 11 also ensures that can settle on the fiber material 2 no disturbing Anflieger and batzen. In the knitting process generated, disadvantageous fiber fly can thus not get back into the main material flow and adversely affect the quality and uniformity of the entire process and especially the emerging from the drafting fiber composite. As a result, otherwise possible turbulences remain controllable, in particular in the draft zones HV and K, so that very high operating speeds can be achieved with the described drafting systems. This applies in particular when the air streams flow in opposite directions to the conveying direction 1 (FIG. 1) because they then flow past the surfaces in the direction of rotation of the rollers and are therefore particularly uniform.

The invention is not limited to the described Ausführangsbeispiele, which can be modified in many ways. This applies, inter alia, to the dimensions given by way of example only. The intended in each case form and construction of the flow channels 10, 11 may vary within wide limits. Furthermore, the number of existing pairs of rollers can be different than described depending on the individual desired delay. In this case, the term "drafting rollers" used is intended to encompass all conventional types of drafting device elements, in particular also the various strap constructions (eg FIGS. 7 and 8). Apart from that, the drafting with other, usually existing facilities, eg. B. a technical suction 43 (Fig. 1 and 9) are provided. In addition, it is clear that more than one tuyere can be assigned to each flow channel and each pair of rolls can be treated as a selected pair of rolls, as explained in detail above with reference to the pair of rolls 6a, 6b. Surprisingly, it has also been found that the device for keeping clean and avoid unwanted fiber fly, at least in individual cases, even from the filler and the limited by this transport channels can exist. In this case, on both sides of the conveyor track, at least between the lower and upper rollers (eg 6a, 6b) of the selected roller pair and the lower and upper rollers (eg 5a, 5b) of at least one preceding and / or following roller pair such filling elements 17 , 18 provided. A particularly good protection of the fiber material 2 is of course achieved if, as in Fig. 1 between all pairs of rollers patches are present, because the fiber material 2 in this case in a continuous, almost closed transport channel is guided. The removal of flying fibers can be done with known blow and / or suction devices. Finally, it is understood that the various features may be applied in combinations other than those described and illustrated.

Claims

claims

1. drafting device for processing fiber material (2) having a plurality of successively arranged, one lower roller (3a to 6a) and one upper roller (3b to 6b) having pairs of rollers for conveying the fiber material (2) along at least one conveyor track in a preselected conveying direction (1) and with a device which serves to keep clean and avoid unwanted fiber fly in the range of at least one selected pair of rollers, characterized in that this device contains filler pieces (17, 18) provided on both sides of the conveyor track and spaces between the lower and upper rollers (For example, 6a, 6b) of the selected pair of rollers and the lower and upper rollers (eg 5a, 5b) at least one preceding and / or following roller pair in the conveying direction are assigned such that they a transport channel which shields the fiber material (2) to the outside (17a, 18a) form.

2. drafting arrangement according to claim 1, characterized in that between the lower and upper rollers (3a to 6a, 3b to 6b) of all pairs of rollers such filler pieces (17, 18) are provided.

3. Drafting system according to one of claims 1 or 2, characterized in that the device further on both sides of the conveyor track each one to the lower or upper roller (eg 6a, 6b) of the selected pair of rollers and the filling pieces associated therewith (17, 18) approaching, for the removal of fiber fly certain flow channel (10, 11).

4. drafting arrangement according to claim 3, characterized in that the flow channels are parallel to the conveyor track.

5. drafting arrangement according to one of claims 3 or 4, characterized in that the flow channels are connected to a suction source (y).

6. Drafting system according to one of claims 3 to 5, characterized in that the device further comprises blowing nozzles (15, 16) which are arranged so that air flows generated by them substantially parallel to the conveying path and tangential to the rollers of the selected pair of rollers the flow channels (10, 11) flow.

7. drafting arrangement according to claim 6, characterized in that the blowing nozzles (15, 16) are arranged so that the air streams opposite to the conveying direction (1) of the fiber material (2) through the flow channels (10, 11) flow.

Drawframe according to one of Claims 1 to 7, characterized in that the covers (14) located on the side of the upper roller of the selected pair are fastened to a pressure arm (7) for the upper roller.

Drawframe according to one of Claims 6 to 8, characterized in that the blast nozzles (15, 16) are arranged so that the air streams impinge on points on outer peripheral surfaces of the rollers (6a, 6b) of the selected pair of rollers between outer vertices (6Sl, 6S2) of these rollers (6a, 6b) and the conveyor track are.

10. drafting system according to one of claims 1 to 9, characterized in that the rollers (3a to 6a; 3b to 6b) with in the conveying direction (1) of the fiber material (2) different peripheral speeds can be driven and at least one roller pair whose rollers (6a , 6b) are drivable at the greatest peripheral speed, which forms selected roller pair.

11. Drafting system according to claim 10, characterized in that it comprises at least one conveyor track with at least three pairs of rollers, namely an input roller pair (3a, 3b), a middle roller pair (4a, 4b, 5a, 5b) and a pair of output rollers (6a, 6b) and the pair of output rollers (6a, 6b) forms the selected roller pair.

12. Drawframe according to claim 11, characterized in that the flow channels (10, 11) in each case from the rollers (6a, 6b) of the pair of output rollers to the rollers (3a, 3b) of the input roller pair are extended.

13. Drafting system according to one of claims 6 to 12, characterized in that the arrangement is made such that the air streams with an overpressure to the environment of about 150 mm water column can be generated.

14. Drafting system according to one of claims 5 to 13, characterized in that the suction source (y) for generating a low negative pressure to the environment in the

Flow channels (10, 11) is set up.

15. Drawframe according to one of claims 1 to 14, characterized in that it comprises at least two laterally juxtaposed drafting sections each having a plurality of successively arranged, each having a lower roller (4al, 4a2) and a top roller (4b 1, 4b2) having pairs of rollers which form a corresponding plurality of conveying paths intended for conveying fiber material (2), and in that each drafting section comprises filling pieces (17, 18) and / or flow channels (10a, 10b; IIa, IIb) and / or blowing nozzles (15, 16) is provided according to one of claims 1 to 14.

16. drafting system according to claim 15, characterized in that the lower rollers (4al, 4a2) of the adjacent drafting sections each individual, juxtaposed flow channels (10a, 10b) are assigned, which extended through common outer covers (12) and transversely to the conveyor tracks , with the covers (12) connected partitions (22) are limited.

17. Drawframe according to claim 15 or 16, characterized in that the upper rollers (4bl, 4b2) of the adjacent drafting sections are attached to pressure arms (7) and these top rollers (4bl, 4b2) each individual, adjacent flow channels (IIa, IIb) are assigned by outer covers (14) and transverse to the conveyor tracks extending partitions (23) are limited, wherein the covers (14) and the partitions (23) on the pressure arms (7) are attached.

18. Drafting system according to one of claims 1 to 17, characterized in that the device further comprises a arranged at an input of the drafting, for shielding the fiber material (2) during its supply specific protective tube (trocar) (20).

19. Drafting system according to claim 18, characterized in that at least one of the two lower and upper rollers (3a to 6a; 3b to 6b) associated flow channels (10, 11) in a conveying direction (1) in front of the pair of input rollers (3a, 3b ) crossing the conveyor track and that the protective tube (20) extends through this flow channel (11) and ends in a gusset of the input roller pair (3a, 3b).

20. Drawframe according to one of claims 1 to 19, characterized in that in the pairs of rollers (4a, 4b; 5a, 5b, 6a, 6b) formed delay zones (AV, HV) open compressors (26) are provided.

21. Drawframe according to one of claims 1 to 20, characterized in that in the pairs of rollers (5a, 5b, 6a, 6b) formed delay zones (HV) turbulence brakes (27) are provided, between the roller pairs (5a, 5b, 6a 6b) shield the clamping gaps before the entry of circulating air currents.

22. Drawframe according to claim 21, characterized in that the turbulence brakes (27) with cover elements (28a, 28b) are provided, which at the inlet side to at least one, of associated rollers (6a, 6b) formed clamping gap at a small distance the peripheral surfaces of this Rollers (6a, 6b) are opposite (29a) or sliding against these abutment (29b).

23. Drawframe according to claim 22, characterized in that with the covering Rolling elements (6a, 6b) are provided with smooth surfaces of elements (28a, 28b) provided.

24. Drawframe according to one of claims 11 to 23, characterized in that the upper roller (6b) of the output roller pair is arranged axially iridescent.

25. Drafting system according to one of claims 11 to 24, characterized in that it comprises two, a delay zone (HV) forming roller pairs (5a, 5b, 6a, 6b) and between the upper rollers (5b, 6b) a Riemchenkäfig (30) an air-permeable belt (31) running over a suction box (33) is arranged.

26. Drafting system according to claim 25, characterized in that the suction box (33) has a tapered in the conveying direction opening (34).

27. Drawframe according to claim 25 or 26, characterized in that on the side facing away from the Riemchenkäfig (30) side of the conveyor track a fiber material (2) contacting, but not crushing plate (35) is arranged.

28. Drawframe according to one of claims 25 to 27, characterized in that the suction box (33) is simultaneously formed as a turbulence brake, the

Upper roller (6b) of the in the conveying direction (1) trailing pair of rollers associated and according to one of claims 16 to 18 is formed.

29. Drawframe according to one of claims 25 to 28, characterized in that the plate (35) is simultaneously formed as a turbulence brake, the lower roller (6 a) in the conveying direction (1) trailing pair of rollers associated and according to one of claims 16 to 18 is trained.

30. Drawframe according to one of claims 1 to 29, characterized in that in the conveying direction (1) behind its last pair of rollers (6a, 6b) as a spinning device (36) formed compacting device is provided.

31. Drafting system according to claim 30, characterized in that the spinning device (36) comprises a spinneret (36a) which is formed on its input side as an up to an outlet gap of the last pair of rollers (6a, 6b) reaching hopper having a flat, elongated inlet opening (38a) having a width (B) which corresponds at least to the width of the exiting from the exit slit fiber material (2).

32. drafting system according to claim 31, characterized in that the funnel has a circular outlet opening (38b) having such a diameter (D) that the ratio B: D is about 5: 1.

33. drafting system according to claim 31 or 32, characterized in that on the spinneret (36 a) a spinning tube (36 b) follows.