EP1629143B1 - Nozzle core for a device used for producing loop yarn, and method for the production of a nozzle core - Google Patents

Abstract

The invention relates to a ceramic nozzle core and a method for producing a ceramic nozzle core which is part of a device used for producing loop yarn. The inventive ceramic nozzle core is embodied with an approximately constant wall thickness and a reduced size so as to perform the central functions of the yarn processing duct comprising air injection and a yarn outlet for forming loops while being produced in a molding process. In a particularly preferred method, the ceramic nozzle core is injection-molded with high precision. The inventive ceramic nozzle core can be configured in a miniaturized fashion and as part of a two-piece nozzle core, the ceramic nozzle core being inserted into an outer nozzle core jacket. The two-piece nozzle core can be incorporated into a housing known in prior art, for example, as a replaceable nozzle core.

Description

Technical area

The invention relates to a method for producing a ceramic nozzle core as part of a Vorichtung for the production of loop yarn and a nozzle core for a device for the production of loop yarn.

State of the art

The term "texturing" is partly understood to mean the refinement of spun filament bundles or the corresponding continuous yarns with the aim of giving the yarn a textile character. In the following description, the term "texturing" is understood to mean the production of a large number of loops on individual filaments or the production of loop yarn. An older solution for texturing is in the EP 0 088 254 described. The continuous filament yarn is fed to the yarn guide channel at the entrance end of a texturing nozzle and texturized at a trumpet-shaped exit end by the impact forces of a supersonic flow. The yarn guide channel is cylindrical with a constant cross section. The entry is slightly rounded for easy insertion of the untreated yarn. At the trumpet-shaped outlet end is a guide body, which takes place between the trumpet shape and the guide body looping. The yarn is supplied to the texturing nozzle with a great deal of tradition. The tradition is needed for loop formation on each individual filament, resulting in a titer increase at the exit end.

The EP 0 088 254 was based on a device for texturing at least one, consisting of a plurality of filaments continuous yarn. The nozzle includes a Garnführungskanal and at least one in the radial direction in the channel opening feed for the pressure medium. The generic nozzle had an outwardly flared outlet opening of the channel and a in the Outlet opening projecting, with the same an annular gap forming spherical or hemispherical guide body. It has been recognized that with textured yarns, maintaining yarn properties during and after the finishing process is an important criterion for the utility of such yarns. Further, the blending of two or more yarns and the individual filaments of the textured yarns is also essential for achieving a uniform appearance of the goods. Stability is used as a concept of quality.

To determine the instability I of the yarn yarn strands are formed with four turns of one meter circumference on a reel, as explained by means of a multifilament yarn on polyester with a titer 167f68 dtex. These strands are then loaded for one minute with 25 cN, and then the length X is determined. This is followed by a load of 1250 cN for one minute. After relieving the strand is again loaded with 25 cN after one minute and then determines the length γ after another minute. This gives the value of instability: $$\mathrm{l}\mathrm{=}\frac{\mathrm{Y}\mathrm{\cdot }\mathrm{X}}{\mathrm{X}}\mathrm{\cdot }\mathrm{100}\mathrm{\%}$$

The instability indicates what percentage of permanent strain is caused by the applied load. Of the EP 0 088 254 It was the object to provide an improved device of the type described, with which an optimal texturing effect can be achieved, which ensures a high stability of the yarn and a high degree of mixing of the individual filaments. As a solution, it has been proposed that the optimum outer diameter of the convexly curved outlet opening of the channel should be at least equal to 4 times the diameter of the channel and at least 0.5 times the diameter of the spherical or hemispherical guide body ( 5). oduktionsgeschwindigkeiten in a range of 100 to over 600 m / min. found. Interestingly enough, the notifying party succeeded in successfully marketing appropriate nozzles over a period of more than 15 years. The quality of the yarn produced with it was judged to be very good over a period of 1 ½ decades. Increasingly, however, the desire for an increase in performance was expressed. The Applicant succeeded with the solution according to EP 0 880 611 a massive performance increase to well over 1000 m / min. Yarn transport speed. The core idea for the increase in output was to intensify the flow conditions in the expanding supersonic channel, ie in the zone in the looping takes place. As a special test criterion, the yarn tension was recognized at the exit from the texturing nozzle. Many series of tests revealed that according to the solution EP 0 088 254 the yarn tension after about 600 m / min. Yarn transport speed drops sharply. This is ultimately the explanation for the power limitation of these nozzle types. The proposal of EP 0 880 611 with the intensification of the flow in the supersonic channel gave an unexpected increase in the yarn tension, which allowed the transport speed to over 1000 m / min. to increase. The quality of the yarn processed at that time was initially judged to be the same, if not better, even at the highest transport speeds. However, the practice subsequently showed surprises in that in many applications the yarn quality did not meet the desired requirements.

It was at the EP 0 880 611 recognized that the first key to the yarn tension quality is after the texturing die. Only if it is possible to increase the yarn tension, the quality can be improved. The breakthrough was made possible, as the flow of blast air jet was increased over the Mach 2 area. Many test series confirmed that not only improves the quality, but that the quality is negatively affected by an increase in production speed in a remarkably small amount. Even a slight increase in Mach number over 2 has already yielded significant results. The best explanation for the corresponding intensification of the Texturierporzesses is seen in the fact that the speed difference is increased immediately before and after the impact front, which directly affects the corresponding attack forces of the air on the filaments. The increased forces in the area of the impact front cause an increase in the yarn tension. By increasing the Mach number, the events on the shock front are directly increased. According to the invention, the law was recognized: higher Mach number = stronger impact = more intensive texturing. The intensified supersonic flow covers the individual filaments of the open yarn on a wider front and much more intensively, so that no slings can escape laterally beyond the impact zone of the impact front. Since the generation of supersonic flow in the acceleration channel based on the expansion, obtained by a higher Machbereich, so z.Bsp. instead Mach 1.5 Mach 2.5, also an increase or nearly a doubling of the effective outlet cross-section. Various surprising observations could be made and confirmed in combination with the new invention:

The comparative experiments, state of the texturing according to EP 0 088 254 and solution in the context of EP 0 880 611 The texturing quality is at least equal to or better than the texturing quality at lower production speed with a supersonic channel designed for the lower Mach range at a higher production speed. The texturing process is at air velocities in the front of over Mach 2, so z.Bsp. Mach 2.5 to Mach 5, so intense that almost all snares are recorded and integrated into the yarn, even at highest yarn throughfeed speeds. The generation of an air velocity in the high Machbereich within the acceleration channel causes the texturing to collapse up to the highest speeds no longer. Second, the whole filament composite is guided evenly and directly into the impact front zone within clear outer channel boundaries.

In the acceleration channel, the yarn is pulled in by the accelerating air jet over the corresponding path, further opened and transferred to the directly subsequent texturing zone. The blown air jet is then passed to the acceleration channel without deflection through a discontinuous and strongly expanding section. One or more yarn threads with the same or different overfeed can be introduced and with a production speed of 400 to over 1200 m / min. textured. The compressed air jet in the supersonic channel is accelerated to 2.0 to 6 Mach, preferably to 2.5 to 4 Mach. The best results are achieved when the exit end of the yarn channel is limited by a baffle. The textured yarn is discharged approximately at right angles to the Garnkanalachse through a gap.

The total theoretically effective expansion angle of the supersonic channel should be from the smallest to the largest diameter above 10 °, but below 40 °, preferably within 15 ° to 30 °. According to the currently available roughness values, an upper limit angle (total angle) of 35 ° to 36 ° has resulted with respect to the production of sera. In a conical acceleration channel, the compressed air is accelerated substantially steadily. The nozzle channel section directly in front of the supersonic channel is preferably made approximately cylindrical, with the delivery component being blown into the cylindrical section in the direction of the acceleration channel. The pull-in force on the yarn is increased with the length of the acceleration channel. The nozzle extension or the increase of the Mach number gives the intensity of the texturing. The acceleration channel should have at least a cross-sectional widening range of 1: 2.0, preferably 1: 2.5 or greater. It is further proposed that the length of the acceleration channel is 3 to 15 times, preferably 4 to 12 times larger than the diameter of the yarn channel at the beginning of the acceleration channel. The acceleration channel can be designed to be continuously widened in whole or in part, have conical sections and / or have a slightly spherical shape. However, the acceleration channel can also be formed finely graduated and have different acceleration zones, with at least one zone with high acceleration and at least one zone with small acceleration of the compressed air jet. If the aforementioned boundary conditions were observed for the acceleration channel, then the said variations of the acceleration channel proved to be nearly equivalent or at least equivalent. The yarn channel subsequently has a strongly convex yarn channel mouth, preferably a trumpet shape widened by more than 40 °, following the supersonic channel, the transition from the supersonic channel into the yarn channel mouth preferably being discontinuous. A decisive factor was also found that with a baffle especially the pressure conditions in the texturing can be positively influenced and kept stable. A further preferred embodiment of the texturing nozzle is characterized in that it has a continuous yarn channel with a central cylindrical portion into which the air supply opens.

• das Öffnen des Garnes und
• das Texturieren des Garnes

With all previous investigations it could only be confirmed, that with texturing nozzles with radial air blowing into the yarn channel according to EP 0 088 254 determined data is the optimal injection angle for the treatment air at 48 °. As a complete surprise, it was found in the most recent experiments that the enlargement of the injection angle with nozzles according to EP 0 880 611 already brought an unexpected increase in the quality of the textured yarn in the first series of tests. The inventors subsequently recognized that the two process zones,

• opening the yarn and
• the texturing of the yarn

Key features are and must be optimally coordinated with each other. Repeatedly repeated experiments showed that in the solution according to EP 0 088 254 the limitation in the texturing zone and therefore an increase in the yarn opening brings only disadvantages.

From the field of Garnverwirbelung, which is not the subject of the present application, it is known that the Garnöffnungseffekt is greatest at a Einblaswinkel of 90 °. The goal of swirling is to form regular knots in the yarn. As an example of the turbulence will be on the DE 195 80 019 directed. On the other hand, textured yarns should not be knotted under any circumstances. There is a borderline for the injection angle for the two fundamentally different methods of knot formation and looping. The various functions for achieving the highest yarn qualities, even at the highest yarn transport speeds, achieved an unexpected increase, as will be explained below. At least from the point of view of the applicant, it was perceived as a great disadvantage that elaborate production processes were necessary for the production of the so-called nozzle cores. All attempts with more economical processes, such as pressing or injection molding, failed. It was not possible within the scope of the specifications to produce usable blanks, be it by compression molding or injection molding. The reason was the peculiarity of the material ceramic. Ceramic is still one of the best materials in terms of wear and durability.

The new invention has now been based on the object, on the one hand to ensure all identified advantages of the nozzle cores described and on the other hand to develop new production processes, which allows a low-cost production of the nozzle cores.

Presentation of the invention

The inventive method is characterized in that the ceramic nozzle core is formed with approximately constant wall thickness and reduced in size is made on the central functions of the Garnbehandlungskanals with air injection and yarn outlet for the loop formation and in the molding process.

A particularly advantageous embodiment is characterized in that the ceramic nozzle core is injected in a high-precision process.

The nozzle core according to the invention is characterized in that it is designed as a ceramic nozzle core with an approximately constant wall thickness and reduced in size to the central functions of the yarn treatment channel with air injection and yarn outlet for loop formation and can be produced in the molding process.

The Applicant previously assumed that for each new development is an important criterion is to form the nozzle core as a removable core, such that a nozzle core with other internal dimensions and air inlet angles can be used. This makes it possible, e.g. To replace an existing nozzle core of the prior art with a few manipulations and to take full advantage of the new development. Only now has the inventor recognized that this positive demand for the past developments was taken too literally and severely hampered further development. The result was that each new nozzle core was designed in its external dimensions identical to the old nozzle cores. The result was that blanks for the nozzle core were increasingly no longer be produced in the casting or pressing process, and always unfavorable conditions were created for a production in the molding process. The new invention has freed itself from the literal compulsion to design the ceramic nozzle core as a removable core. Rather, the design is consistently aligned with the inner central functions. The whole shape can now be determined according to casting requirements and e.g. be formed by a bipartite miniaturized ceramic nozzle core with outer nozzle ceramic jacket. Only the outer jacket, the dimensions of the nozzle cores of the prior art will be given, which also takes over the function of the removable core.

The new invention allows a number of particularly advantageous embodiments, for which reference is made to the claims 4 to 10. A particularly advantageous embodiment is characterized in that the Garnbehandlungskanal has at least one cylindrical portion and an extension portion, wherein the injection within the cylindrical portion, preferably approximately in the central region of the longitudinal side of the ceramic nozzle core, is arranged. The extension section may be according to EP 0 088 254 be completely trumpet-shaped or according to EP 0 880 611 have a conical and a trumpet-shaped section. The yarn channel has a central, preferably cylindrical portion, which is transferred in the transport direction without jumping in the conical enlargement, wherein the compressed air is injected with a sufficient distance to the conically expanded supersonic channel in the cylindrical portion. The experiments in connection with the new invention brought different new insights:

For texturing nozzles with intensified supersonic flow according to EP 0 880 611 At each yarn titer a quality improvement could be achieved, if the Einblaswinkel was increased over 48 °. The increase in quality begins with a marked increase in an increase in the angle over 50 °. With injection angles greater than 52 °, sometimes up to 60 ° and even 65 °, the yarn quality remains surprisingly constant. However, the optimum blowing angle is also dependent on the yarn titer.

Preferably, the compressed air is blown over three circumferentially offset by 120 ° holes in the yarn channel. It is crucial in any case that the yarn opening intensified by blowing the compressed air into the yarn channel, but a knot formation is avoided in the yarn. The opening of the yarn on the one hand and the texturing of the yarn on the other hand must be optimized for each. In order to optimize the two totally different functions, they have to be carried out spatially separated, but in quick succession, such that the opening follows immediately the texturing, or that the termination of the yarn opening process passes directly into the texturing. All central texturing functions for the production of a loop yarn can now be realized within a miniaturized ceramic nozzle core. The new ceramic nozzle core may be part of a device which has a ball-shaped impact body which can be lowered into the extension section, wherein the trumpet-shaped section has a radius which is in relation to the diameter of the impact body. Preferably forms according to the EP 0 088 254 , the impact body having the trumpet-shaped portion an annular gap, wherein the outer diameter of the convexly curved outlet opening of the channel is at least equal to 4 times the diameter of the channel and at least equal to 0.5 times the diameter of the ball or hemispherical conductor body.

Most preferably, the nozzle core is formed in two parts and has an outer nozzle body, in which the ceramic nozzle core is used, wherein the outer nozzle body is made in plastic. The outer plastic body now has the function of a removable body in the previous understanding with the required mounting dimensions and fasteners. The plastic body also has a protective function for the ceramic nozzle core. Preferably, a clamping point is arranged between the outer nozzle body and the ceramic nozzle core for fastening the ceramic nozzle core in the outer nozzle body. Furthermore, an annular compressed-air channel is arranged between the ceramic nozzle core and the nozzle body in the region of the cylindrical section, via which the air injection takes place by means of the injection bores. The annular Compressed air channel has in each of the two end regions of the cylindrical portion a sealing point for sealing the compressed air.

According to a further embodiment, the nozzle core is designed as a quick-change element within the device, so that it can be quickly installed and removed together with the ceramic nozzle core from the device. The nozzle core can be formed in two parts, with an inner ceramic nozzle core and an outer nozzle body, both parts are a device with rotary drive and the nozzle body with the built-ceramic core is driven.

In the two-part solution, the ceramic nozzle core and the outer nozzle body in the assembled state at the Garnaustrittsende form an approximately flat surface. According to an important requirement for the new solution, shape and thickness variations should be compensated with the design of the nozzle body. The structural requirements with regard to assembly and installation in a machine can be intercepted in this way via the outer nozzle body. The ceramic nozzle core can be optimally designed with respect to the production of ceramic blanks. Most preferably, the nozzle body is produced as a plastic injection-molded part and formed in the outer dimensions as a removable part with respect to corresponding solutions of the prior art.

The new invention is based on the type of texturing nozzles on the radial principle. The blown air is guided in the radial direction of the supply point in a cylindrical portion of the yarn channel immediately in an axial direction at an approximately constant speed up to the acceleration channel. As in the prior art of EP 0 880 611 can be textured with the new solution one or more yarn threads with a variety of traditions.

Brief description of the invention

die Figur 1

den Garnkanal in dem Bereich der Garnöffnungs- und Texturierzone;

die Figur 2

einen Düsenkern mit eingesetztem Keramik-Düsenkern sowie einem Prallkörper am Austrittsende des Garnkanales;

die Figur 3

einem zweiteiligen Düsenkern, eingebaut in eine Vorrichtung zur Erzeugung von Schlingengarn;

die Figuren 4a, 4b und 4c

eine Lösung gemäss Stand der Technik ( EP 0 088 254 ) mit einem Düsenkern, wobei die Figur 4c eine Ansicht gemäss Pfeil A ist;

die Figur 5

ein Vergleich von texturiertem Garn mit unterschiedlichen Ausgestaltungen des Düsenkernes;

die Figuren 6a und 6b

den "Rahmen" für die Kernfunktionen der Erzeugung von Schlingengarn;

die Figur 7

eine Lösung mit drehbar angetriebenem Düsenkern;

die Figur 8

eine 3-D-Darstellung mit einem geteilten bzw. zweiteiligen Düsenkern, mit einem äusseren Düsenkernmantel sowie einem Keramik-Düsenkern;

die Figur 9

einen Schnitt durch einen zweiteiligen Düsenkern entsprechend den Figuren 6a und 8;

die Figur 10

einen Schnitt eines zweiteiligen Düsenkernes entsprechend der Figur 6b und 8.

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

the figure 1

the yarn channel in the area of the yarn opening and texturing zone;

the figure 2

a nozzle core with inserted ceramic nozzle core and a baffle at the outlet end of the yarn channel;

the figure 3

a two-piece nozzle core, built into a device for Production of loop yarn;

Figures 4a, 4b and 4c

a solution according to the prior art ( EP 0 088 254 ) with a nozzle core, wherein the Figure 4c is a view according to arrow A;

the figure 5

a comparison of textured yarn with different configurations of the nozzle core;

Figures 6a and 6b

the "framework" for the core functions of looping yarn production;

the figure 7

a solution with rotatably driven nozzle core;

the figure 8

a 3-D representation with a divided or two-part nozzle core, with an outer nozzle core shell and a ceramic nozzle core;

FIG. 9

a section through a two-piece nozzle core according to the FIGS. 6a and 8th ;

the figure 10

a section of a two-piece nozzle core according to the FIG. 6b and 8th ,

Ways and execution of the invention

$$\frac{\mathrm{DAE}}{\mathrm{d}}\mathrm{\sim }\mathrm{2.5}\mathrm{\to }{\mathrm{M}}_{\mathrm{DE}}\mathrm{=}\mathrm{Mach}\mathrm{3.2}$$

In the episode will now be on the FIG. 1 Referenced. The texturing 1 has a yarn channel 4 with a cylindrical portion 2, which also corresponds to the narrowest cross-section 3 with a diameter d at the same time. From the narrowest cross section 3 of the yarn channel 4 passes without jump in cross section in an acceleration channel 11 and is then expanded in a trumpet shape, the trumpet shape can be defined with a radius R. Due to the adjusting supersonic flow, a corresponding shock front diameter DA _E can be determined. Due to the impact front diameter DA _E , the detachment or tear-off point A ₁ , A ₂ , A ₃ or A ₄ can be determined relatively accurately. For the effect of the shock front is on the EP 0 880 611 directed. The acceleration range of the air can also be defined by the length ℓ ₂ from the point of the narrowest cross-section 3 and the tear-off point A. Since it is a true supersonic flow, it can be calculated about the air velocity. The FIG. 1 shows a conical configuration of the acceleration channel 11, which corresponds to the length ℓ ₂ . The opening angle α ₂ is given as 20 °. The Ablössstelle A ₂ is located at the end of the supersonic channel, where the yarn channel in a discontinuous, strongly conical or trumpet-shaped extension 12 merges with a Öffnunswinkel ∂> 40 °. Due to the geometry results in a shock front diameter D _AE . As an example, the following conditions result: $$\mathrm{L}\mathrm{2}\mathrm{/}\mathrm{d}\mathrm{=}\mathrm{4.2}\mathrm{;}\mathrm{vd}\mathrm{=}\mathrm{330}\mathrm{m}\mathrm{/}\sec \mathrm{,}\left(\mathrm{<figure-callout\; id="1"\; label="Mach"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">Mach</figure-callout>}1\right);$$

$$\frac{\mathrm{DAE}}{\mathrm{d}}\mathrm{~}\mathrm{2.5}\mathrm{\to }{\mathrm{M}}_{\mathrm{DE}}\mathrm{=}\mathrm{Mach}\mathrm{3.2}$$

An extension of the acceleration channel 11 with a corresponding opening angle causes an increase in the shock front diameter D _AE . Immediately in the area of the shock front formation, the greatest possible compression shock front 13 with subsequent abrupt pressure increase zone 14 is formed. The actual texturing takes place in the area of the compression shock front 13. The air moves about 50 times faster than the yarn. Through many experiments it could be determined that the release point A ₃ , A _{4 can} also migrate into the acceleration channel 11, namely, when the feed pressure is lowered. In practice, it is now necessary to determine the optimum feed pressure for each yarn, the length (ℓ2) of the acceleration channel being designed for the unfavorable case, that is to say rather a little too long. With M _B , the center line of the injection bore 15 and M _GK the Mlttellinie the Garnkanales 4 and the intersection of M _GK and M _B denoted by SM. Pd is the location of the narrowest cross section at the beginning of the acceleration channel 11, 11 is the distance from SM and Pd, ℓ2 is the distance from Pd to the end of the acceleration channel (A4). Löff denotes approximately the length of the yarn opening zone, Ltex approximately the length of the yarn texturing zone. The larger the angle β, the more the yarn opening zone is increased in the backward direction.

In the episode will now be on the FIG. 2 Reference is made, which shows a preferred embodiment of a whole nozzle core 5 in cross section. The outer fitting shape is preferably adapted exactly to the nozzle cores of the prior art. This applies above all to the critical installation mass, the bore diameter B _D , the total length L, the nozzle head height K _H and the distance L _A for the compressed air connections PP '. The experiments have shown that an injection angle β greater than 48 ° is optimal. The distance X of the respective compressed air holes 15 is critical with respect to the acceleration channel. The nozzle core 5 has a yarn introduction cone 6 in the inlet region of the yarn, arrow 16. The measure "X" ( FIG. 6 ) indicates that the compressed air bore 15 is preferably set back at least approximately by the size of the diameter d from the narrowest cross section 3. Seen in the transport direction (arrow 16), the texturing 1 and the nozzle core 5 has a Garneinführkonus 6, a cylindrical central portion 7, a cone 8, which simultaneously corresponds to the acceleration channel 11, and an extended texturing 9. The texturing becomes transverse to the flow bounded by a trumpet 12, which may also be designed as an open conical funnel.

The FIG. 2 shows in multiple enlargement compared to the actual size of a two-part nozzle core 5, consisting of a ceramic nozzle core 24 and an outer nozzle core jacket 25 with a baffle or impact body 10. The new nozzle core 5 can be designed as a replacement core for a nozzle core of the prior art. In particular, the dimensions B _d , E _L as installation length, L _A + K _H and K _H are therefore preferably not only the same, but also produced with the same tolerances. Furthermore, the trumpet shape in the outer exit region is preferably also produced in the same way as in the prior art, with a corresponding radius R. The impact body 10 can have any shape: spherical, spherical, flat or even in the form of a dome. The exact position of the impact body in the exit region is maintained by maintaining the outer mass, corresponding to a same take-off gap S _p1 . The texturing 18 is limited backwards through the acceleration channel 11. The texturing space can also be enlarged into the acceleration channel, depending on the height of the selected air pressure. The ceramic nozzle core 24, as in the prior art, as a whole made of a high quality material, such as ceramic and is the actually expensive part of a texturing. Important in the new nozzle is that the conical cylindrical wall surface 17 as well as the wall surface 19 in the region of the acceleration channel further has the discharge point of the compressed air holes 15 in the yarn channel highest quality.

The FIG. 3 shows a whole nozzle head 21 with a two-part nozzle core 5 and a baffle 10 which is anchored via an arm 22 adjustable in a known housing 20. For the threading of the baffle body 10 is pulled away with the arm 22 in a known manner according to arrows 23 from the working area of the texturing or swung away. The compressed air is supplied from a housing chamber 27 via the compressed-air bores 15. The nozzle core 5 is clamped to the housing 20 via a clamping strap 26. Instead of a spherical shape, the impact body may also have a dome shape.

The Figures 4a, 4b and 4c show a solution of the prior art accordingly EP 0 088 254 with a long yarn guide channel 29 through which the yarn 30 to be textured passes. The Garnführungskanal 29 is supplied by a radial compressed air bore 15 with compressed air. The injection hole 15 closes with the axis of Garnführungskanales 29 an angle α of about 48 °. The diameter of the injection hole 15 is 1.1 mm. The yarn guide channel 29 has a diameter d ₁ of 1.5 mm and has an outwardly flared, convexly curved outlet opening. The convex curvature has the form of a Circular arc with a radius R of 6.5 mm, to which the end face 34 of the texturing 1 forms a tangential plane, wherein the points of contact of the curvature arc with the tangent plane lie on a circle with the diameter D. The diameter D corresponds to the formula D = d ₁ + 2 R and is therefore 14.5 mm. The baffle body 10, whose diameter d _{2 is} 12.5 mm, protrudes partially into the channel outlet opening 35 and forms an annular gap 31 with the inner wall of the latter. The yarn 30 * emerging from the nozzle is drawn off over the edge of the outlet opening.

As in the FIGS. 4a and 4b 2, a carrier 33 is attached to the nozzle-carrying housing 20 with an axis 32 around which an arm 22 fixedly connected to the baffle 10 is pivotable. By pivoting the arm 22, the annular gap 31 can be adjusted or the guide body can be lifted for threading. The smooth yarn 30 is fed via a delivery mechanism 36 of the texturing 1 and withdrawn as a textured yarn 30 * via a delivery mechanism 37.

The FIG. 5 shows bottom left purely schematically the texturing of the prior art according to EP 0 088 254 , In this case, two main parameters are highlighted: an opening zone Oe-Z ₁ and a shock front diameter DAs, starting from a diameter d, corresponding to a nozzle, as in the EP 0 088 254 is described. In contrast, the upper right texturing according to EP 0 880 611 shown. It is clearly recognizable that the values Oe-Z ₂ and D _{AE are} larger. The yarn opening zone Oe-Z ₂ begins shortly before the acceleration channel in the region of the compressed air supply P and is already significantly larger with respect to the relatively short yarn opening zone Oe-Z _{1 of} the solution according to EP 0 088 254 , The essential statement of the FIG. 5 lies in the diagrammatic comparison of the yarn tension according to the prior art (curve T 311) with Mach <2 and a texturing according to the invention (curve S 315) with Mach> 2 and the new nozzle. In the vertical of the diagram, the yarn tension is in CN. In the horizontal, the production speed Pgeschw. in m / min. shown. The curve T 311 permits the significant collapse of the yarn tension over a production speed of 500 m / min. detect. Above about 650 m / min. broke the texturing with the nozzle accordingly EP 0 088 254 together. In contrast, the curve S 315 with the corresponding nozzle from the EP 0 880 611 in that the yarn tension is not only much higher, but in the range of 400 to 700 m / min. is almost constant and also decreases slowly in the higher production area. The increase in the Mach number is one of the most important parameters for the intensification of the texturing. The enlargement of the injection angle is one the most important parameter for quality of texturing, as shown with the new nozzle as the third example in the upper left corner. As an example, the injection angle is given in the range of 50 ° to 60 °. The yarn opening zone Oe-Z3 is larger than in the solution top right (according to EP 0 880 611 ) and significantly larger than in the solution bottom left (according to EP 0 088 254 ). The other procedural process parameters are the same for all three solutions. In addition to the different injection angle of the range 45 ° to 48 ° and now over 45 °, the surprisingly positive effect in the first section of the yarn opening zone, such as OZ ₁ and OZ ₂ or as is marked in the corresponding circle. The external difference lies only in the change of the injection angle. The marked increase of the thread tension starts at an angle of more than 48 ° and can only be understood with a combinatorial effect. At least as far as the surprisingly positive effect is understood at the time, 48 ° Einblaswinkel means a threshold, especially in texturing according to EP 0 880 611 , This texture nozzle type has a sufficient power reserve, so that even a slight intensification of the yarn opening is converted into an increase in yarn quality.

In practice, the textured yarn runs after the second delivery plant via a quality sensor, z.Bsp. with the market name HemaQuality, called ATQ, in which the tensile force of the yarn is measured 30 * (in cN) and the deviation of the instantaneous tensile force (sigma%). The measuring signals are fed to a computer unit. The appropriate quality measurement is a prerequisite for the optimal monitoring of production. The values are also an indicator of yarn quality. In the airblast texturing process, the quality determination is made more difficult in that there is no defined loop size. It is much easier to determine the deviation from the quality that the customer finds to be good. This is possible with the ATQ system because the yarn structure and its deviation can be detected, evaluated and displayed by a single characteristic, the AT value, via a yarn tension sensor. A yarn tension sensor detects, in particular, the thread tension force after the texturing nozzle as an analogue electrical signal. From this, the AT value is continuously calculated from the mean value and the variance of the yarn tension measured values. The size of the AT value depends on the structure of the yarn and is determined by the user according to his own quality requirements. If the thread tension or the variance (regularity) of the thread tension changes during production, the AT value also changes. Where the upper and lower limits are concerned, it can be determined with yarn mirrors, knit or fabric samples. They are different depending on the quality requirements. The advantage of ATQ measurement that different disturbances from the process are detected simultaneously, eg. Uniformity of texturing, thread wetting, filament breaks, nozzle contamination, impact ball distance, hot pin temperature, air pressure differences, POY insertion zone, yarn pattern, etc.

In the consequence becomes on the Figures 6a and 6b Referenced. The two figures show the "framework" for the core function in the production of loop yarn. The FIG. 6a is based on the solutions according to the FIGS. 4a to 4c , The FIG. 6b starts from the solution according to FIGS. 1, 2 and 3 out. The corresponding parts of the two figures are designated by the same reference numerals. The two Figures 6a and 6b show, for example, the size proportions of the individual areas for the core functions.

The FIG. 6a clearly shows that the cylindrical portion (cylinder A) is about twice as long as the extension portion (EA). Three radial injection holes 15 are set back by a distance ö.A, the opening portion, opposite to the extension portion (EA), and are located in the central portion of the cylindrical portion, as indicated in accordance with the blowing portion (ins. A.). In the extension section (EA), the diameter D and the radius R are of great importance. The cylindrical portion has a diameter Gd. Another special feature of the solution according to FIG. 6a is the angle α, which has an angle of about 48 ° in the transport direction of the yarn according to arrow 16. An insertion cone EK is only as long as required for threading, but is only very short. The diameter Bd is dimmed in accordance with the prior art. A comparison of FIGS. 4a and Fig. 6a clearly shows that the cylindrical section (cylinder A) of the new solution is less than half as long, relative to the solution of the prior art FIG. 4a , This is an important feature in the concrete embodiment of a ceramic nozzle core according to the invention. Viewed from the texturing function of the prior art, the length of Garnführungskanales is designed unnecessarily long. The yarn guide channel GA was in the prior art according to the thickness dimension of the housing 20, as shown in FIG. 4b is clearly visible.

The FIG. 6b shows against the FIG. 6a two special features. The solution according to FIG. 6b has a first conical section (Kon A.) and a trumpet-shaped texturing section TA * instead of a trumpet-shaped section EA, corresponding to the solution of FIG EP-PS 0 880 611 , A comparison of Figures 6a and 6b shows that the cylindrical portion (cyl. A *) in the FIG. 6b is formed shortened, according to the specifications X1 and X2. As a profit, the opening section öA * at the FIG. 6b enlarged trained. The conical section is preferably formed with an opening angle χ of 12 ° to 40 °. The second special feature lies in the arrangement of the radial injection bore 15, with an angle β of preferably 50 ° to 70 °, which increases the stability of the texturing to a very high level and allows best texturing qualities.

The FIG. 7 shows a further particularly advantageous embodiment, which of the EP-PS 1 022 366 emanates. Practice shows that air-jet texturing nozzles for the production of loop yarn must be cleaned in relatively short time intervals. The EP-PS 1 022 366 now proposes to set the nozzle core continuously or alternately in rotation. This made it possible to extend the cleaning interval massively. The FIG. 7 shows how the new invention can be used in a rotating driven nozzle core. It is proposed to use a two-part nozzle core, approximately according to FIG. 2 , The FIG. 7 shows as an example the simultaneous joining and texturing of two yarns, a yarn A and a yarn B, which in each case via a yarn guide 40, respectively. 41 are guided in the yarn introduction cone 6. The nozzle core consisting of a ceramic nozzle core 24 and an outer nozzle core jacket 25 is arranged in a rotatably mounted rotary sleeve 42 which is mounted in the drive housing 44 via ball bearings 43. The compressed air is supplied via a compressed air chamber 45 and a compressed air connection 46, wherein a plurality of seals 47 prevents escape of compressed air. A worm wheel 48 is held in the drive housing 44 via a collar 49 and a cover 50. The drive takes place via a drive shaft 51, a Übertriebsrad 52 and a worm wheel 48th

The FIG. 8 shows in a 3D representation of a two-part nozzle core, according to the FIG. 6a and the Figures 3 and 7 , The FIG. 8 shows the assembly of a ceramic nozzle core 24 with an outer nozzle core shell 25. The ceramic nozzle core 24, as in the FIG. 8 is indicated, are inserted into the nozzle core casing 24 by hand, with the last insertion movement a snap-like locking 60 of the ceramic nozzle core 24 is held exactly in position. Outwardly, a flat surface 34 forms accordingly FIG. 2 , Between the ceramic nozzle body 24 and the outer nozzle core shell, a cylindrical compressed air chamber 61 is formed, which is closed to the outside by seals 62, so that the compressed air can flow only through the radial injection holes 15 in the yarn channel 4.

The example according to FIG. 8 shows very clearly another, very important feature of the new solution, namely the requirement of approximately constant wall thickness of the ceramic nozzle core 24, wherein at three points, WSt1, WSt2, WSt3 each with a dimension arrow, the wall thickness is displayed. For the requirements of the installation, three different thicknesses are given for the outer nozzle core casing 25 with the dimension darts D1, D2, D3. Since the outer nozzle core can be made eg in plastic, even large variations in thickness have no harmful effect. By contrast, the inner ceramic nozzle core can be produced optimally in accordance with the requirements for the production of ceramic blanks by the pressing method, in particular by injection molding.

The FIG. 9 illustrates on average the solution according to FIG. 6a and 8th ,

The FIG. 10 shows on average the FIGS. 6b and 8th , In both figures, the ceramic nozzle core 24 is installed in the outer nozzle core casing 25. According to another embodiment, not shown, the ceramic nozzle core 24 directly into a housing 20 approximately as FIG. 4b to be built in. In this case, the housing 20 must have fitting openings corresponding to the miniaturized ceramic nozzle core 24.

Claims (9)

1. Method for producing a nozzle core as part of an apparatus for producing loop yarn, characterized in that the nozzle core is formed in two parts and has an outer nozzle body into which a ceramic nozzle core is inserted, and in that the ceramic nozzle core is formed with an approximately constant wall thickness and is reduced in size to the central functions of the yarn treatment duct with air blow-in and yarn outlet for loop formation, and is produced in a moulding method.
2. Method according to Claim 1, characterized in that the ceramic nozzle core is injection-moulded in a high-precision method.
3. Nozzle core for an apparatus for producing loop yarn, characterized in that the nozzle core is formed in two parts and has an outer nozzle body into which a ceramic nozzle core is insertable, and in that the ceramic nozzle core is formed with an approximately constant wall thickness and is reduced in size to the central functions of the yarn treatment duct with air blow-in and yarn outlet for loop formation, and is producible in a moulding method.
4. Nozzle core according to Claim 3, characterized in that the yarn treatment duct has at least one cylindrical section (cyl. A.) and a widening section (EA), wherein the blow-in (blow-in) is arranged within the cylindrical section, preferably approximately in the central region of the longitudinal side of the nozzle core, wherein the widening section is formed preferably entirely in a trumpet-shaped manner or has a conical section and a trumpet-shaped section, wherein, in the case of a conical section, this has an opening angle of at least 12°.
5. Nozzle core according to either of Claims 3 and 4, characterized in that the air blow-in of the ceramic nozzle core has one or more, preferably three, blow-in holes which are arranged in a manner inclined at an angle of at least 48°, in particular in the range of 52° to 65°, to the transport direction.
6. Nozzle core according to one of Claims 3 to 5, characterized in that it is part of an apparatus which has a spherical baffle body which is lowerable into the widening section, wherein the outside diameter of the convexly curved outlet opening of the duct is at least equal to 4 times the diameter of the duct and at least equal to 0.5 times the diameter of the spherical or hemispherical guiding body (5).
7. Nozzle core according to Claim 3, characterized in that between the outer nozzle body and the ceramic nozzle core there is arranged a clamping point for fastening the ceramic nozzle core in the outer nozzle body, wherein an annular compressed air duct is arranged preferably between the ceramic nozzle core and the nozzle body in the region of the cylindrical section, the air blow-in taking place via said compressed air duct by means of the blow-in holes and the annular compressed air duct having a respective sealing point, particularly preferably in the two end regions of the cylindrical section, for sealing off the compressed air.
8. Nozzle core according to one of Claims 3 to 7, characterized in that the nozzle core is formed as a quick-change element inside the apparatus and can be installed in and uninstalled from the apparatus quickly together with the ceramic nozzle core, wherein it is formed preferably in two parts having an inner ceramic nozzle core and an outer nozzle body and the two are part of an apparatus having a rotary drive, wherein the nozzle body is drivable by way of the installed ceramic nozzle core.
9. Nozzle core according to one of Claims 3 to 8, characterized in that it is formed in two parts having a ceramic nozzle core and an outer nozzle body, wherein, in the assembled state, the yarn outlet end forms an approximately planar surface and variations in shape and thickness can be compensated by way of the design of the nozzle body, wherein the nozzle body is produced as an injection-moulded plastics part and is formed in its external dimensions as a replacement part with respect to corresponding solutions in the prior art.

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