EP1861526B1 - Method and entanglement nozzle for producing knotted yarn - Google Patents

Abstract

The invention relates to an entanglement nozzle and to a method for producing fine knotted yarn with highly regular knots by means of air jets comprising a yarn treatment channel. According to said method, air is blown transversally to the yarn treatment channel. Said blown air forms a respective double swirl both in the yarn transport direction and against the yarn transport direction for creating the knots. According to the invention, upon entry into the yarn treatment channel, the blown air is converted into two intense, stationary eddy currents that are not disrupted by filament bundles, in an air swirling chamber that only extends for a short distance in the longitudinal direction of the yarn channel. The regularity of the knots can be significantly improved, despite the tiny dimensions of the air swirling chamber, which projects beyond the longitudinal wall of the yarn channel for a maximum 0.5 mm or for 5% to 22% of the width (B) of said channel. It is also possible to create hard or soft knots that can be subsequently undone.

Description

Technical area

The invention relates to a method for the production of knotted yarn or twist yarn of DTY (Draw Twist Yarn) and / or smooth yarns with high regularity of knots by means of air nozzles with a Gambehandlungskanal and blowing air, which is injected transversely to the Gambehandlungskanal, the blast air in Garnförderrichtung and against the Garnförderrichtung ever a double vortex for generating the node forms. The invention further relates to a Verwirbelungsdüse for the production of knot yarn with high regularity of the nodes with a continuous Gambehandlungskanal and a Blasluftzufuhrkanal, wherein the Blasluftzufuhrkanal is directed to the longitudinal center axis of the Garnbehandlungskanales.

State of the art

In the recent past, increasingly finer filaments have been produced. These are called microfilaments when the denier per filament (dpf) is between 0.5 and about 1.2. The game made of it is called Microfilamentgame. One speaks of Supermikrofilamentgamen, if the dpf <0.5 lies. When microfilaments are subsequently referred to, supermicrofilaments are included unless otherwise noted. Already yarns with a dpf over 1.2 require gentle processing, so that neither single filaments nor the whole yarn breaks. To an even greater extent, this applies to the microfilament games. In the case of microfilament yarns, the combination of all filaments has an important meaning. It must be ensured that do not stand out individual filaments and thus give a risk of breakage. DTY-Game means "Draw Twist Yam", in English: false twist texture yarns.

• Knotenstabilität,
• Knotenzahl pro Meter,
• Regelmässigkeit der Knotenbildung

für den jeweiligen Anwendungsfall zu finden. Bei gröberen Filamenten dpf 1.2- 4 wird eine Knotenzahl von bis zu 110 und bei Microfilamentgarnen bis zu 200 pro Meter Garn gewünscht. Der Luftdruck liegt für Microfilamente etwa bei 0,5 bis 1,5 bar. Die Voreilung liegt bei 3 % - 6 %. Bei feinen Filamenten werden im Stand der Technik 140 Punkte bzw. Knoten pro Meter Garnlänge erzeugt. Erwünscht ist dabei eine höchstmögliche Regelmässigkeit der Knotenfolge. Es soll verhindert werden, dass knotenfreie Garnstrücke entstehen, in denen ein oder mehrere Knoten hintereinander fehlen. Das Mass der Stabilität sagt aus, unter welchen Zugkräften sich die Knoten wieder auflösen. Bei der einfachsten Art, dies zu prüfen, wird das Garn zwischen zwei Händen gehalten und langsam oder ruckartig gespannt.There are used in the market in relatively large amounts swirled yarns with the so-called air turbulence. There are two trends in the market. In many applications, well trained, strong and stable knots are required in all filament finenesses due to air turbulence. The air nozzle must be designed with respect to all parameters. The situation is different with fine, in particular with Microfilamentgamen. These yarns are used to produce fine fabrics that have to be very supple and silky when touched. This shows that the formation of very stable and almost indissoluble nodes are disadvantageous can, undesirably, be seen as a kind of rastering, especially on the finest, uncolored tissue. Within the yarn processing knots are desired; but these should later disappear completely when processing the fine game into fabrics or other fabrics. The so-called knotted yarn is produced with the swirling in swirling nozzles. The knots ensure the local integration of all filaments and short knot sequences over the whole yarn run. The aim of the turbulence is a high number of knots per meter with regular spacing between the nodes. The device conditions are given with a Garnbe-treatment channel with a Blasluftzufuhr transverse to the Gamkanal. The blowing air flows on both sides of the yarn channel and forms by the approximately central blowing in the Gamtransportrichtung and against the Gamtransportrichtung ever a so-called double vortex. By performing the game through the corresponding vortex zone, a kind of alternating air movement results, which is ultimately responsible for a repetitive formation of nodes with short breaks between the nodes. The art is now, with targeted design of all dimensions of the yarn channel of a Verwirbelungsdüse and the type of air supply, the air pressure, the tradition and the Gamtransportgeschwindigkeit an optimum between the three Gamqualitätskriterien,

• Node stability,
• Number of knots per meter,
• Regularity of knot formation

to find for the respective application. For coarser filaments dpf 1.2- 4 a number of knots of up to 110 and for microfilament yarns up to 200 per meter of yarn is desired. The air pressure for microfilaments is approximately 0.5 to 1.5 bar. The lead is 3% - 6%. With fine filaments 140 points or knots per meter of yarn length are produced in the prior art. Desirable is a highest possible regularity of the node sequence. It is to be prevented that node-free yarn pieces arise in which one or more nodes are missing in succession. The measure of stability states under what tensile forces the nodes dissolve again. In the simplest way to test this, the yarn is held between two hands and stretched slowly or jerkily.

The DE 197 00 817 shows a special form of a Verwirbelungsdüse for carpet yarn, so for very rough BCF game. It was assumed that a process for the continuous production of spun-textured filament yarns in a continuous yarn channel or vortex channel of a vortex nozzle. The filament yarn is directed through a transversely directed into the vortex nozzle and forward and backward from the Whirled yarn channel outflow blowing air flow and discharged the exhaust air of the backward vortex approximately in the opposite direction to the Blasluftzuführung from the Garneinführbereich. As a solution, it is proposed that two unevenly acting vortices be produced in the swirling channel, wherein the forward swirl is designed to be more effective than the backward swirl.

The DE 37 11 759 Starting from finer to medium yarns and trying to improve the processability of the game in subsequent processing, such as weaving, knitting, knitting and tufting machines. The inventor started out from a swirling device for swirling multifilament yarns which has at least one yarn channel, wherein yarn guides are arranged at intervals from the inlet and outlet mouth of the yarn channel and the filaments of a respective multifilament yarn can be swirled in the yarn channel by means of a blowing nozzle. The yarn undergoes a change in direction of less than 90 ° when entering and leaving the yarn channel, and the blowing angle of the blowing nozzle is less than 90 °. As a new solution, it is proposed that the yarn guides are arranged so that the yarn is applied to the Gamkanal with the compressed air supply off so that it extends in the yarn channel parallel to its longitudinal direction and thereby rests against the outlet mouth of the at least one tuyere. The distance of the Gamführer is from the Gamkanalmündungen adjacent to them a maximum of 30 mm. The length of the yarn channel is a maximum of 40 mm for uncrimped multfilament yarns and a maximum of 30 mm for crimped multifilament yarns. Of the DE 37 11 759 At least the merit of having carried the knowledge of the positive effect of a short yarn can for the production of Knotengam in a broader professional world. Specifically, a yarn channel length is proposed for textured or crimped yarns of 10-28 mm. In particular, the range of 10 mm yarn channel length is understood to be short.

Recent experience shows that the very widespread use of air nozzle for the production of Knotengam in very fine, especially microfilaments, not satisfied. With regard to fine yarns, especially in the case of microfilament yarns, the highest regularity of the knot sequence is required in each case, but in some cases only weak, temporarily constant, but reversible knots, that is to say, knit yarn loops again. The knots must not be visible in the finished fabric. It has been tried many times to operate nozzles of the prior art, for example, with lower pressures of the feed air. It is known that at lower atmospheric pressures weaker nodes arise, but with the disadvantage of a Often unacceptable irregularity, both the node strength and node stability as well as the distances between the nodes.
Most recently, the market has a very strong tendency towards the use of so-called microfilament yarns. The question of the regularity of the nodes as well as at least sufficient stability of the nodes for further processing is of central importance in many applications. It is required in most cases that the number of nodes may not fall noticeably below the currently achievable 140 knots / m, and that the required pressure for the blown air can be reduced with regard to the energy requirement.

• Druckreduktion für die Blasluft,
• Knotenzahl pro Meter > 140/m für dpf < 1.2,
• einstellbare Knoten- Stabilität,
• hohe Regelmässigkeit der Knotenfolge.

The invention has now the object of finding a method and a Verwirbelungsdüse with which even at high yarn transport speeds the aforementioned quality criteria in the production of fine, especially microfilament yarns, can be achieved, with the four goal:

• Pressure reduction for the blown air,
• Number of knots per meter> 140 / m for dpf <1.2,
• adjustable knot stability,
• high regularity of the node sequence.

Presentation of the invention

The method according to the invention is characterized in that the blown air in the entry region into the yarn treatment channel in an air swirl chamber is displaced into two strong stationary air swirl flows, which are almost undisturbed by filament bundles.

The swirling nozzle according to the invention is characterized in that a blown air duct extension is formed in the mouth region of the blown air supply duct in the yarn treatment duct to form an air swirl chamber for two counter-rotating stationary air swirl flows, whereby the blown air duct extension exceeds less than 22% but more than 5% of the yarn duct width.

• Erstens sind es Verwirbelungsdüsen mit durchgehenden Gamkanälen, wie z.B. in der einleitend erwähnten DE 37 11 759 beschrieben wird. Das typische ist dabei ein gleichmässiger durchgehender Garnkanal.
• Zweitens sind es Verwirbelungsdüsen mit einer Gam-Verwirbelungskammer in dem Bereich der Blasluftzufuhr in den Garnkanal. Man ging dabei von dem Modell aus, dass die geöffneten Einzelfilamente des Games gleichsam eine zusätzliche Kammer brauchen, um auf die Seite auszuschwingen, und so verbesserte Knotenstabilität erzeugt werden.

In the prior art, with respect to the new invention, two swirl nozzles are known:

• First, there are swirl nozzles with continuous Gamkanälen, such as in the introductory mentioned DE 37 11 759 is described. The typical is a uniform continuous yarn channel.
• Second, there are swirl nozzles with a Gam swirling chamber in the area of the blast air feed into the yarn channel. It was based on the model that the open individual filaments of the game as an additional Chamber need to swing out to the side, and so improved node stability can be generated.

It is interesting that in the former case a high number of nodes is achieved. The disadvantage, however, is that the stability of the nodes and the regularity of the node sequence is noticeably deteriorated even with a slight reduction of the pressure of the blowing air. In the second case, although the node stability is sufficient, but the number of nodes for many applications is not enough.

The new invention has been solved by the so-called "vortex chamber". As Vortexchamber is understood a relatively large extension of the yarn channel before and after the area of the Lufteinblasstelle. The goal was to give the yarn or individual filaments the opportunity to oscillate within the vortex chamber. The new invention, however, seeks an improvement on the air side. It is proposed an air-twist-chamber or Microwirbelkammer for the air. It is true that the node stability could be increased with the vortex chamber. However, this is at the expense of the number of nodes. There are fewer knots per meter of yarn produced. The individual nodes are longer. Quite surprisingly, in laboratory experiments with the new solution according to the invention, a hitherto unattained nodal stability with uniform nodules could be achieved with almost no loss in terms of the number of nodules. The micro-vortex for the air alone is possible because the local air flow is in the sonic and supersonic range and the phenomena of supersonic flow are used in the locally constrained two strong stationary air swirling currents are enforced.

It has also been recognized by the inventor that in the previous methods an insufficient model of knot formation was assumed. The counter-rotating vortices in each outflow direction are stable as long as there is no yarn in the yarn channel. The presence of the game causes a back and forth of the vortex. Investigations by the applicant showed that the very short-term oscillation of the two opposing vertebrae is at the center of knot formation. A combination between the two large vertebrae and an indeterminable number of small vertebrae causes the tearing and knotting of the individual filaments. The fact is, the complete instability of the opposing vortices, when yarn is transported through the gas channel. In contrast, they limited themselves to the model of the prior art on the double vortex formation. It overlooked the resulting contradiction. It has now been recognized by the inventor that the situation in the treatment of fine yarns can be noticeably improved if instead of a continuous, uniform yarn channel or a yarn vortex chamber an air swirl chamber is mounted in the inlet region of the blowing air in the yarn treatment channel, so that the air flow is placed at the relevant point in two strong undisturbed swirling flows. The air swirl chamber is a miniature blast air duct extension and forms a transition between a completely stable swirl flow in the area of the air injection and the subsequent just as completely unstable vortex zone to the exit from the yarn channel. Thus, a sharp whirling approach in both Garntransportrichtung as well as against the Gamtransportrichtung is specified. The air currents take place at sound and supersonic speeds, so that the corresponding phenomena can be used additionally.

The invention allows a number of advantageous embodiments. It is assumed that the model that in the air swirl chamber, a short region is generated with a stable swirl flow, which is then followed in both Gamtransportrichtung as well as against the Garntransportrichtung a swirl zone. Below is a tabular overview of the different types of yarn with the corresponding filament fineness: Endless Filament Game: subdivision of common yarn and filament fineness Denier per filament (dpf) yarn type DTY-Game (false twist) Straight game BCF Game (Bulk Continuous Filament) yarn count Fine medium Rough Fine medium Rough Fine medium Rough Titre (denier) 20-75 75 -150 > 150 40 -300 300 -1000 > 1000 500 -1000 1000-3000 3000 - 7000 Filament fineness Supermicro 0.2-0.5 0.2 - 0.5 0.2 - 0.5 S - M S - M Micro 0.5 - 1.2 0.5 - 1.2 0.5 - 1.2 0.5 - 1.2 S-HD S-HD M - HD Fine 1.2-2 1.2-2 1.2-2 1-2 5-10 5-10 5-10 M-HD M-HD medium 2-4 2-4 2-5 2-5 10-20 10-20 HD HD Rough 2-6 2 - 6 5-10 5-20 20-30 20-30 HD HD Interlace Stability: S = soft M = medium HD = hard

Larger test series with the solution according to the invention have shown that compressed air of more than 0.5 bar, but less than 3 bar, can be used for the blowing air and a knot yarn with high stability of the knots can be produced. Yarns smaller than 2 to 5 dpf, especially smaller than 1 dpf, were treated. The Garnkanalquerschnitt is preferably formed semicircular or U-shaped, wherein the yarn channel width (B) is greater than the Garnkanaltiefe (T). The Luftdrallkrammer represents a dome-like air duct extension in the yarn duct. The air swirl chamber is formed at least approximately symmetrical and protrudes on both sides less than 0.5 mm on the side Garnkanalwandungen. A very important point of the new solution is that the air swirl chamber is designed miniaturized such that the yarn bundle can not completely penetrate into the lateral extension of the air swirl chamber. The air swirl chamber protrudes only a fraction of a millimeter, the Garnkanalwand. For example, for a 1.6 mm wide yarn channel a maximum width of the air chamber of 2.2 mm proposed. It was initially completely surprising to all those involved that such a small measure could be used to achieve correspondingly large effects. However, the explanation lies in the targeted design of the supersonic air flow.

The new invention could be examined with large series of tests with DTY yarns (false twist yarns). The results were good for fine, medium and coarse yarns. The results were most surprising in fine yarns, especially microfilament yarns. First attempts with plain yarns were positive, although the result was less pronounced in relation to DTY-Gamen. At least on the basis of theoretical considerations, the new invention can also be used in BCF yarns, in the BCF-Gamen due to the much larger yarn channel widths of up to 8 mm, the air swirl chamber is to survive at most 22%, at least 5% of Gamkanalbreite.

The new invention also allows for a number of advantageous embodiments of the yarn swirling nozzle. It is proposed to form the Gambehandlungsquerschnitt half round or U-shaped and with a flat baffle.

All experiments have clearly shown that the actual critical mass of the air swirl chamber is the lateral protrusion and the longitudinal dimensions. The air swirl chamber is laterally shaped as a miniaturized dome with respect to the Gambehandlungskanat cross section, wherein the air swirl chamber on both sides of the Gambehandlungskanales protrudes less than 0.5 mm. The Überstehmass of smaller 0.5 mm could be confirmed with yarns up to 500 denier, so with Gamkanalbreiten up to 3 mm. Comparative experiments: Influence of the vortex chamber Channel width B (mm) Whirl chamber depth (% of B) Swirl chamber length (mm) test result 2.4 25% 4.21 State of the art 2:35 17.0% 2.17 good *** according to the invention 1.6 0% 0 State of the art 1.6 08.18% 1:51 good ***, reference according to invention 1.6 08.18% 1.81 Well ** 1.6 08.18% 2.11 bad * 1.6 08.18% 2:51 bad * 1.6 08.18% 3:01 bad * * = Loss of knots, stability and regularity
** = Slight loss of knots, easier gain in stability
*** = optimum result with solution according to the invention

For larger yarn channel widths over 3 mm, an overfeed pass of less than 22% and more than 5% of the yarn channel width is required. Preferably, the Überstehmass is between 10% and 20% of the yarn channel width. The air swirl chamber further preferably has an approximately circularly symmetrical outer contour and forms a continuation of the center axis of the Blasluftzufuhrkanales. Most preferably, the width of the Gamkanalquerschnittes is greater than the Garnkanaltiefe formed in the direction of Blasluftzufuhr to intensify the lateral vortex formation. In this case, the treatment channel can be formed as a wide channel with a width of preferably 0.6 to 3 mm, particularly preferably with a ratio of yarn channel width (B) to yarn channel depth (T) of 1.2 to 2.5. According to tests, the length of the air swirl chamber was preferably smaller than 1.3 of the yarn channel width. Advantageously, the length of the air swirl chamber is about 0.7 to 1.6, preferably 0.8 to 1.2 with respect to the width of the Gamkanales, which is substantially below the L / B ratio of about 1.75 of the prior art Technology is.

According to a further preferred embodiment, the blown air supply channel is round or oval or oval with a triangular character or Y-shaped, wherein the side dimension of the Blasluftzufuhrkanales is at most equal to or less than the corresponding Gamkanalbreite. The yarn channel width (B) is made larger than the Luftzufuhrkanalbrefte d, preferably in a ratio B / d of 1.1 to 3.

According to a further very advantageous solution, it is proposed that the yarn channel is formed by a plane displaceable baffle plate and a nozzle plate with the blown air supply. In this case, the yarn channel is preferably formed by a nozzle plate and a slidable slab (as a so-called SlideJet) with an open position of the yarn channel for threading the game and a closed position of the yarn channel for the production of a Knotengames. The nozzle plate is formed as a plate-like ceramic disc, such that the ceramic disc together with a sliding part in the Verwirbelungsdüse and / or that the ceramic disc in the sliding part as removable disc and is removable.

Brief description of the invention

die Figuren 1a - 1f

die Ausgestaltung des Gambehandlungskanals des Standes der Technik mit den neuen Erkenntnissen der gegenläufigen Wirbel auf beiden Abströmseiten;

die Figuren 2a - 2d

die erfindungsgemässe Lösung mit einer Luftdrallkammer;

die Figuren 3a - 3c

verschiedene Querschnittsformen des Blasluftzufuhrkanales;

die Figur 4a

das Ergebnis eines Berechnungsmodelles für die starken stationären Drallströmungen im Bereich der Luftdrallkammer,

die Figur 4b

die instationären Wirbel, welche im Berechnungsmodell ohne die Präsenz des Games stationär sind;

die Figur 4c

ein schematisches Modell für die stationären Drallströmungen im Bereich der Luftdrallkammer sowie der instationären Wirbel in beiden Abströmrichtungen der Behandlungsluft;

die Figuren 5a bis 5e

verschiedene Details einer Düsenplatten mit daran angebrachten Luftkrallkammern;

die Figuren 6a bis 6d

eine komplette Verwirbelungsdüse vom Typus SlideJet in offener und geschlossener Stellung sowie mit ausgebauter Düsenplatte (Figur 6c bzw. 6d);

die Figuren 7a bis 7f

die wichtigsten Folgeschritte für den Ausbau der Schiebeplatte bzw. der Düsenplatte;

die Figuren 8a bis 8d

den Ein- bzw. Ausbau einer Düsenplatte in ein Schiebeteil der Verwirbelungsdüse;

die Figur 9a

schematisch ein unbehandeltes Glattgarn;

die Figur 9b

ein Knotengam mit weichen Knoten;

die Figur 9c

ein Knotengam mit harten Knoten (dunkle Striche);

die Figur 9d

ein Knotengarn des Standes der Technik mit sehr unregelmässiger Knotenbildung;

die Figuren 10a bis 10c

zeigen im Unterschied zu den Figuren 9c bis 9d Unregelmässigkeiten der Knotenfolge, zum Teil mit unterschiedlichen Abständen, zum Teil mit fehlenden Knoten;

die Figur 11

zeigt eine Gegenüberstellung von harten, beinahe nicht mehr auflösbaren Knoten, welche mit Druckluft von 1,5 bis 3 bar erzeugt werden. Rechts im Bild sind weiche Knoten, welche mit Druckluft von 0,5 bis 1,5 bar erzeugt werden und sich im Laufe der Garnverarbeitung meistens wieder auflösen;

die Figuren 12a und 12b

zeigen eine Sonderform des Blasluftzufuhrkanals mit einem Y-förmigen Querschnitt;

die Figur 12c

zeigt ein weiteres Beispiel für die Ausgestaltung einer erfindungsgemässen Luftdrallkammer 11';

die Figuren 13a bis 13d

zeigen eine Lösung der Anmelderin des Standes der Technik mit übergrossem Gamverwirbelungskanal;

die Figur 14a

zeigt eine erfindungsgemässe Lösung und

die Figuren 14b und 14c

Lösungen des Standes der Technik als Vergleich zu Figur 14a;

die Figuren 15a bis 15c

einen Vergleich der Ergebnisse mit Lösungen des Standes der Technik (Figuren 15a und 15b) sowie der neuen Lösung (Figur 15c);

die Figuren 16a und 16b

wichtige Qualitätsunterschiede aus Laborvergleichsuntersuchungen mit Lösungen des Standes der Technik sowie mit der neuen Erfindung;

die Figur 17

die Versuchsergebnisse mit einem Vergleich mit und ohne Air Twist Chamber mit Glattgarn (flat yam, "fully drawn") bei unterschiedlichen Luftdrücken der Speiseluft.

The invention will now be explained with reference to some embodiments with further details. Show it:

Figures 1a - 1f

the design of the Gambehandlungskanals of the prior art with the new knowledge of the opposite vortex on both downstream sides;

Figures 2a - 2d

the inventive solution with an air swirl chamber;

Figures 3a - 3c

various cross-sectional shapes of the Blasluftzufuhrkanales;

the figure 4a

the result of a calculation model for the strong stationary swirl flows in the area of the air swirl chamber,

Figure 4b

the unsteady vortices that are stationary in the calculation model without the presence of the game;

Figure 4c

a schematic model of the stationary swirl flows in the area of the air swirl chamber and the transient vortex in both outflow directions of the treatment air;

Figures 5a to 5e

various details of a nozzle plate with attached Luftkrallkammern;

FIGS. 6a to 6d

a complete swirl nozzle of the type SlideJet in open and closed position as well as with dismantled nozzle plate ( FIG. 6c or 6d);

FIGS. 7a to 7f

the most important subsequent steps for the removal of the sliding plate or the nozzle plate;

FIGS. 8a to 8d

the installation or removal of a nozzle plate in a sliding part of the Verwirbelungsdüse;

Figure 9a

schematically an untreated plain yarn;

Figure 9b

a Knotengam with soft knots;

Figure 9c

a Knotengam with hard knots (dark lines);

Figure 9d

Knotted yarn of the prior art with very irregular knotting;

FIGS. 10a to 10c

show in contrast to the FIGS. 9c to 9d Irregularities of the node sequence, in part with different distances, partly with missing nodes;

the figure 11

shows a comparison of hard, almost indissoluble nodes, which are generated with compressed air from 1.5 to 3 bar. On the right in the picture are soft knots, which are produced with compressed air of 0.5 to 1.5 bar and usually dissolve again in the course of yarn processing;

Figures 12a and 12b

show a special form of Blasluftzufuhrkanals with a Y-shaped cross section;

the figure 12c

shows a further example of the embodiment of an inventive air swirl chamber 11 ';

FIGS. 13a to 13d

show a solution of the Applicant of the prior art with oversized Gamverwirbelungskanal;

Figure 14a

shows a solution according to the invention and

Figures 14b and 14c

Solutions of the prior art as a comparison to Figure 14a ;

FIGS. 15a to 15c

a comparison of the results with solutions of the prior art ( FIGS. 15a and 15b ) and the new solution ( FIG. 15c );

Figures 16a and 16b

important quality differences from laboratory comparative studies with solutions of the prior art as well as with the new invention;

the figure 17

the test results with a comparison with and without Air Twist Chamber with plain yarn (flat yam, "fully drawn") at different air pressures of the feed air.

Ways and execution of the invention

Figures -1a to 1f show the classical model for the production of a knotted yarn 2 'by means of a swirl nozzle 1. In this case, knots K are formed from an untwisted smooth yarn 2 in a yarn treatment channel 3 by the action of blown air BL with the individual filaments Understanding of a double vortex formation of the blown air, both in Garntransportrichtung 7 as well as against the Gamtransportrichtung within the Gambehandlungskanales 3 are generated. The blowing air BL enters via a blast air duct 4 in the direction of arrow 5 and generates, as from the Figures 1b and 1d can be seen, the typical double vortex 6. The knot yarn 2 'leaves according to arrow 8, the swirl nozzle 1. The Gambehandlungskanal 3 has FIGS. 1a and 1b a round cross section. The same applies to the blast air duct 4. The solution according to the Figures 1c and 1d also corresponds to the known prior art and thus represents an improved solution in that the yarn channel 3 is formed by a semicircular shape in a nozzle plate 9 and a flat cover plate 10. Due to this specific shape significantly more pronounced double vortex 6, as with the Figure 1d is expressed.

1. a) Es trifft zu, dass mit dem Blasluftstrahl BL in dem Garnbehandlungskanal ein Doppelwirbel erzeugt wird (Figuren 1b und 1d).
2. b) Der Doppelwirbel wird jedoch gemäss Figuren 1c und 1f völlig gestört, wenn ein Filamentgarn 2 in den Gambehandlungskanal 3 eintritt. Innert Millisekunden werden die stabilen Doppelwirbel bei Eintritt des Games zerstört. Es baut sich in der einen Gambehandlungskanalhälfte ein einseitiger Wirbel 6* auf, während der Wirbel 6** zusammenbricht. Die Folge ist die, dass alle Filamente in dem Gambehandlungskanal 3 auf die rechte Seite schwingen. Die Sammlung aller Filamente auf der rechten Seite zerstört jedoch sofort diesen Doppelwirbel, so dass sich nahezu ohne Verzug ein entsprechend grosser Wirbel 6*** auf der linken Seite einstellt (Figur 1b). Diese Pendelbewegung ist bei Vorhandensein der Blasluft sowie des Filamentgames ein völlig unsteter Dauerzustand und letztlich die Ursache der Knotenbildung.

Only recent studies have shown that knowledge of knot formation was very incomplete. In fact, knot formation does not simply arise from the two stable double whirls 6. A basic requirement for knot formation is the following fact:

1. a) It is true that with the blown air jet BL in the Garnbehandlungskanal a double vortex is generated ( Figures 1b and 1d ).
2. b) The double vortex is, however, according to Figures 1c and 1f completely disturbed when a filament yarn 2 enters the Gambehandlungskanal 3. Within a few milliseconds, the stable double whirlwinds are destroyed when the game starts. It builds up in one Gambehandlungskanalhälfte a one-sided vortex 6 *, while the vortex 6 ** collapses. The result is that all the filaments in the Gambehandlungskanal 3 swing to the right side. However, the collection of all filaments on the right-hand side immediately destroys this double-whirl, so that a correspondingly large swirl on the left side occurs almost without delay ( FIG. 1b ). This pendulum movement is in the presence of blown air and the filament game a completely unsteady steady state and ultimately the cause of node formation.

The FIGS. 2a to 2d show a solution according to the invention. Unlike the FIGS. 1c to 1f the Gambehandlungskanal 3 additionally an air swirl chamber 11, which represents an immediate continuation of the Bläsluftzufuhrkanales 4 in the Gambehandlungkanal 3. The Gambehandlungskanal 3 is dome-like widened at the location of the Blasluftzufuhrkanales 4, as from a corresponding dome 12 in FIG. 2b is recognizable. It arises in a section II, II of the FIG. 4 an additional swirl flow, corresponding to the two arrows 13, 13 'in FIG. 2a , The dome-like expansion allows a locally stationary swirl flow without a negative influence of unsteady vortex movement in the subsequent part of the Gambehandlungskanales 3. The locally stationary swirl flow is rather directly into the transient turbulent flow, corresponding to the two Figures 2c and 2d , The FIG. 2b shows a nozzle plate 9 designed according to the invention. The same reference numerals have been used for the same features as for the same features FIGS. 1 and 2 selected. Clearly visible is the miniature training of the air swirl chamber, which is only so large that the filament bundle can not move in it.

The FIGS. 3a to 3c show three different cross-sectional shapes for the Blasluftzufuhrkanal; the FIG. 3a with circular shape 4 ', FIG. 3b with a half oval 4 "as well as the Figure 3c with an oval shape 4 "'.

The FIGS. 4a and 4b each show the result of a CFD flow calculation. In the FIG. 4a You can see very clearly the Blasluftzuführung BL from bottom to top. The upper level is denoted by E and represents the impact surface of the blast air flow BL on the baffle plate 10. The air swirl chamber 11 results from the two small Kalottenausnehmungen 12. It can be seen in the FIG. 4a clearly the two swirling flows 14, which give a very stable flow in the longitudinal direction in a range of less than 1 to 2 mm. In the FIG. 4a can be seen on the basis of the same invoice model (without the presence of yarn) in the middle of the stationary swirl flow 14 and the top of the picture, the two double swirls 6. Die Figure 4c is a drawing which schematically illustrates the two flow forms.

The FIGS. 5a to 5e show the inventive solution of FIGS. 2 to 4 mounted in a concrete nozzle plate 9 for a SlideJet nozzle.

The Figures 6a and 6b show a whole swirling nozzle 1, which is designed as a SlideJet. The FIG. 6b shows the open or threading position, the FIG. 6a the closed operating position. A nozzle plate 9 is installed in the swirling nozzle 1, wherein a sliding part 23 on the lower leg of a yoke 25 back and forth can slide. The sliding movement is effected by a sliding lever 26, which converts the rotational movement in the linear movement via a corresponding mechanism. The rotational movement of the shift lever 26 is thereby converted into a pure sliding movement according to arrow 27. Very important for the turbulence is a baffle plate 10, which under spring pressure permanently on the upper flat surface of the nozzle plate. 9 is pressed. The flat, flat surface with high surface fineness allows the movement with simultaneous sealing function, for which purpose the baffle plate 10 in ceramic and a nozzle plate 9 in ceramic are particularly well suited. The Gamkanal 3 and an air supply duct are mounted in the nozzle plate 9. For the operating position of the air supply channel with a compressed air source 22 is connectable. The yarn channel 3 is in the operating position by the in FIG. 6a visible part and the lower planar surface of the baffle plate 10 is determined. The FIG. 6c shows a nozzle plate 9. The FIG. 6d shows a whole sliding part 23 with inserted nozzle plate 9. With the FIG. 6d should also be shown that the attachment of the nozzle plate 9 in the sliding part 23 leaves many possible solutions. The nozzle plate 9 can be poured, for example by an injection molding, directly into the sliding part 23, so that ceramic disc and sliding part 23 form an inseparable component. Furthermore, it would be possible to glue the ceramic disk in the sliding part.

The Figure 7a shows the closed operating position. The sliding lever 26 is in the lowered position of the yarn channel 3 for the passage of the game for an air treatment, for which compressed air via a port or a compressed air hole can be fed. By the upward flaps of the shift lever 26, the sliding part 23 is pushed forward ( FIG. 7c ) and simultaneously shut off the air supply, which is accomplished by the displacement of the two Druckluftzuführbohrungen to the dimension G. By pressing a release lever according to arrow K, the spring pressure force on the baffle plate 10 is released and released the engagement of a sliding axis in an engagement groove, so that the sliding part 23 can be pushed forward freely ( FIG. 7b ). The sliding part 23 can now be removed from the device ( Figure 7f ) and the ceramic disk are removed in the opposite direction to the sliding part 23. The replacement takes place in the opposite direction to the FIGS. 7a to 7f ,

With the FIGS. 8a to 8c is shown a very particularly advantageous connection. The FIG. 8a shows the first step for the installation of the nozzle plate 9. The nozzle plate 9 is placed transversely to the sliding direction according to arrow 41 on the sliding part 23. In this case, a negative and a positive part 42, 43 help to set the nozzle plate 9 by hand precisely as with FIG. 8b is shown in perspective view. In the FIG. 8d the nozzle plate 9 is completely deposited on the sliding part 23, wherein the rotational movement of the nozzle plate 9 is already recognizable according to the arrow. The nozzle plate 9 has a cam on both sides and the sliding part 23 has a matching round sliding guide. The nozzle plate 9 has on both sides with respect to a center of rotation Circular segments which fit into the corresponding circular guides of the sliding part 23 with little play. After completing the rotation accordingly FIG. 8d there is a latching point, which engages on light spring pressure from below and fixed the nozzle plate 9 in the operating position.

The FIG. 9a shows untwisted yarn 2. However, this can be both smooth and FZ textured. With the straight lines the individual filaments 45 are indicated. The FIG. 9b shows a soft swirled yarn. Typical are the rather shorter nodes K, where the nodes are symbolized by thin straight lines. The FIG. 9c shows hard, relatively long knots K between the swirled open spots. The hard knots are symbolized by thicker lines. The FIG. 9d shows a typical knot yarn of the prior art with very irregular knots.

The FIGS. 10a to 10c show some examples with irregular knotting.

The FIG. 11 is a juxtaposition of hard and soft knots that are producible with the new invention. The FIG. 11 shows a typical associated area of using compressed air of 1.5 to 3 bar or 0.5 to 1.5 bar. Depending on the market and especially the type of processing hard knots or soft knots are required.

The Figures 12a and 12b show the possibility of using a Y-shaped blast air duct cross-section with corresponding main air duct H and secondary air duct N. Die FIG. 12c shows a further example of the embodiment of an inventive air swirl chamber 11 '.

The FIGS. 13a to 13c show a solution of the prior art, as it has already been produced by the applicant for over 20 years. Here is typical a long Garnverwirbelungskammer with relatively large width and length. Behind this solution stuck the model that the yarn can swing as far as possible in the yarn vortex chamber.

The Figure 14a shows a solution according to the invention and as a comparison ( FIGS. 14b, 14c ) Two solutions of the prior art. All previous investigations have shown that there is a critical measure for the survival of the air swirl chamber. This is about 0.5 mm. In all chamber configurations, where the chamber laterally protrudes by more than 0.5 mm, a noticeable reduction in quality is found. The Previous experiments have shown that the lateral protrusion of the chamber on the Gambehandlungskanal 3 is to be judged as critical. It has been found that the chamber in the Gamkanallängsrichtung is advantageously less than 1.3 x yarn channel width (B) long.

The Figures 15a, 15b and 15c show a juxtaposition of knot formation: The FIG. 15a according to a solution according to FIGS. 13a to 13c , the FIG. 15b according to a solution without swirl chamber according to Figures 1 and 1a and the FIG. 15c the inventive solution. For all three solutions, yarns of eg 80 f 72, 80 f 108, 72 f 72 and 80 f 34 are used. Depending on the mode of operation or the pressure of the blast air, soft or hard knots are created.

The two FIGS. 16a and 16b show results with comparative experiments that FIG. 16a with coarse and the FIG. 16b with fine yarn. The left figure shows the number of knots per meter, the middle figure the scatter of the knots and the right figure the stability or the loss of knots under tension. There were consistently used nozzles with no chamber or roundish chambers (with dome widths K of 2.2, 2.4, 2.6, 2.8 mm). The chamber was designed in a dome-like shape. It can be clearly seen that the best result was achieved with the inventive calotte width K of 2.2 mm with a true air swirl chamber according to the invention. The yarn channel width was 1.6 mm in all tests, the yarn channel depth was 1.0 mm and the air injection hole was 1.1 mm. The inventive advantages are also visible when in addition Elasthan Game are embedded in the nozzle and combined with the filament yarns mentioned above.

Claims (24)

1. Method for production of fine, in particular of microfilament knotted yarn or twisted yarn of DTY yarns and/or flat yarns with a high regularity of the knots by means of air nozzles, with a yarn treatment channel and with blast air which is blown in transversely to the yarn treatment channel, the blast air forming in the yarn-conveying direction and opposite to the yarn-conveying direction in each case a double vortex for generating the knots, characterized in that, in the inlet region into the yarn treatment channel, the blast air is set, in an air swirl chamber, into two strong contradirectional stationary swirl flows virtually undisturbed by the filament bundle, the air swirl chamber being formed as a blast-air supply channel widening of less than 22% but more than 5% of the yarn-channel width, or in the case of yarn-channel widths of up to 3 mm, the widening projecting beyond the yarn-channel width on both sides to a maximum of 0.5 mm.
2. Method according to Claim 1, characterized in that a short region with a stable swirl flow is generated in the air swirl chamber and is subsequently followed both in the yarn transport direction and opposite to the yarn transport direction by a reciprocal vortex zone.
3. Method according to Claim 1 or 2, characterized in that a pressure of 0.5 to 1.5 bar is used for the blast air, in order to produce soft knots which come loose again during further processing.
4. Method according to Claim 1 or 2, characterized in that compressed air of more than 1.5 bar is used for the blast air in order to produce hard knots which do not come loose during further processing.
5. Method according to one of Claims 1 to 4, characterized in that yarns of less than 10 to 15 dpf, preferably of less than 2 dpf, are treated.
6. Method according to one of Claims 1 to 5, characterized in that the yarn-channel cross section is of semi-circular or U-shaped design, the yarn-channel width (B) being greater than the yarn-channel depth (T) .
7. Method according to one of Claims 1 to 6, characterized in that the air swirl chamber constitutes a cap-like air-channel widening in the yarn channel, and the flow runs in a similar form through the yarn channel with respect to a cross section.
8. Method according to one of Claims 1 to 6, characterized in that the air swirl chamber is designed to be at least approximately symmetrical to the yarn channel centre axis and projects beyond the lateral yarn-channel walls on both sides for the production of DTY yarn by less than 0.5 mm or between 5% and 22% of the yarn-channel width.
9. Method according to Claims 1 to 8, characterized in that the length of the air swirl chamber is about 0.7 to 1.6 with respect to the width of the yarn treatment channel.
10. Method according to one of Claims 1 to 8, characterized in that the air swirl chamber is designed to be miniaturized in such a way that the filament bundle cannot penetrate into the lateral widening of the air swirl chamber.
11. Twisting nozzle for the production of fine, in particular of microfilament knotted yarn with a high regularity of the knots, with a continuous yarn treatment channel and with a blast-air supply channel, the blast-air supply channel being directed on to the longitudinal centre axis of the yarn treatment channel, characterized in that a blast-air channel widening is formed in the mouth region of the blast-air supply channel in the yarn treatment channel, in order to form an air swirl chamber for two contradirectional stationary swirl flows, the blast-air supply channel widening projecting to less than 22% but more than 5% of the yarn-channel width, or in the case of yarn-channel widths of up to 3 mm, the widening projecting beyond the yarn-channel width on both sides to a maximum of 0.5 mm.
12. Twisting nozzle according to Claim 11, characterized in that the yarn treatment cross section is designed so as to be semi-circular or U-shaped and with a plane baffle ceiling.
13. Twisting nozzle according to Claim 11 or 12, characterized in that the air swirl chamber is designed laterally in a similar form to a miniaturized cap with respect to the yarn treatment channel cross section.
14. Twisting nozzle according to one of Claims 11 to 13, characterized in that the air swirl chamber projects by less than 0.5 mm on both sides of the yarn treatment channel.
15. Twisting nozzle according to one of Claims 11 to 14, characterized in that the air swirl chamber is less than 1.3 x the yarn-channel width (B) long in the yarn-channel longitudinal direction.
16. Twisting nozzle according to one of Claims 11 to 15, characterized in that the air swirl chamber has an at least approximately circular-symmetrical outer contour and preferably forms a continuation of the centre axis of the blast-air supply channel.
17. Twisting nozzle according to one of Claims 11 to 16, characterized in that, to intensify the lateral air vortex formation, the width of the yarn-channel cross section is greater than the yarn-channel depth in the direction of the blast-air supply.
18. Twisting nozzle according to Claim 17, characterized in that the treatment channel is designed as a wide channel with a width of preferably 0.6 to 3 mm, particularly preferably with a ratio of yarn-channel width (B) to yarn-channel depth (T) of 1.1 to 2.5.
19. Twisting nozzle according to one of Claims 11 to 18, characterized in that the blast-air supply channel is designed to be round or oval or oval with a triangular character or Y-shaped, the lateral dimension of the blast-air supply channel being at most equal to or less than the corresponding yarn-channel width.
20. Twisting nozzle according to Claim 17 or 19, characterized in that the yarn-channel width (B) is greater than the air supply channel width d, preferably in a ratio B/d of 1.2 to 3.
21. Twisting nozzle according to one of Claims 11 to 20, characterized in that the yarn channel is formed by a plane displaceable baffle plate and a nozzle plate with the blast-air supply.
22. Twisting nozzle according to one of Claims 11 to 21, characterized in that the yarn channel is formed by a nozzle plate and by a baffle plate displaceable with respect to the latter and as what is known as a SlideJet, with an open position of the yarn channel for threading in the yarn and with a closed position of the yarn channel for producing a knotted yarn.
23. Twisting nozzle according to one of Claims 11 to 22, characterized in that the nozzle plate is designed as a plate-like ceramic disc, and the ceramic disc can be mounted and demounted together with a sliding part in the twisting nozzle, and/or in that the ceramic disc can be mounted and demounted as an interchangeable plate in the sliding part.
24. Use of the twisting nozzle according o one of Claims 11 to 23 for producing knotted yarn of BCF yarns.

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