EP1634982A1 - Ceramic nozzle and apparatus for stuffer-box crimping of a synthetic multifilament yarn - Google Patents

Abstract

In a process to convert straight synthetic multifilament fibres to wrinkled fibres by curling action in a jet, the multifilament fibres are fed to a jet (2) with two formed ceramic parts (1). The ceramic parts consist of two flat plates with precisely formed interlocking parts (5, 26, 8, 29). The two ceramic parts form a jet tip within the fibre feed duct. Each half (1) of the ceramic jet has circular drill holes that receive matching locating pins passing through both halves. Each half of the ceramic plate has a semi-circular groove that on assembly forms part of the fibre duct.

Description

The invention relates to a device for upsetting crimping of a synthetic multifilament yarn with a ceramic nozzle.

For stuffer box crimping of a multifilament thread, known devices have a delivery nozzle and a stuffer box arranged downstream of the delivery nozzle. Here, the thread is conveyed by means of the delivery nozzle in the stuffer box, compressed to a yarn plug and thereby crimped. The delivery nozzle is supplied with a conveying medium, preferably a hot gas, which conveys the thread within a thread channel to the stuffer box. Within the stuffer box, the thread plug is formed. Here, the multifilament lies in loops on the surface of the yarn plug and is compacted by the pumped medium, which can escape from the stuffer box above the yarn plug. For this purpose, the chamber wall of the stuffer box has at the periphery a plurality of slot-shaped openings through which the fluid can escape. In order to obtain a uniform crimping of the thread, the plug formation takes place in the stuffer box with very high uniformity. The frictional forces resulting from the relative movement of the yarn plug in the stuffer box have a significant influence on the texturing process. There is an equilibrium of forces between the conveying action or the dynamic pressure effect of the conveying medium flowing out of the thread channel of the conveying nozzle and the braking effects on the thread stop caused by the frictional forces. By adjusting a delivery pressure or by setting an additional suction of the pumped medium, the conveying effect can be influenced or regulated. In contrast, that is due to the friction between the yarn plug and the chamber wall generated braking effect essentially dependent on the nature of the chamber wall.

EP 1 060 302 shows a device for treating yarn with a detachable screw connection. A two-part constructed treatment body consists of at least one ceramic part, wherein the two parts are positioned to each other during assembly with dowel pins. The treatment body is then clamped with a screw penetrating it against a machine part. In particular, the device relates to texturing nozzles which can be made relatively small.

EP 1 116 806 shows a known device for compression crimping. It is assumed that a texturing nozzle for the treatment of a thread-like material in a between at least two superposed, basic bodies shaped treatment channel. The device further comprises at least one nozzle body for supplying a gaseous treatment medium and at least one venting part in the treatment channel. There, it is proposed that the treatment channel is formed at least in some areas with a resistant material as the metallic base body. For this purpose, various one-piece ceramic inserts are positioned in the region of the nozzle channel. It is known that the coefficient of thermal expansion is very different between ceramic and metallic material. Since the compression crimping high temperatures and temperature fluctuations occur during operation can vary greatly thermal stresses on the device for Stauchkräuseln occur that may lead to positional shifts of the parts of the device and thus a faulty yarn plug formation.

Another device for Stauchkräuseln is for example known from WO 03/004743. As a particularly preferred embodiment of the device is described there that the gas-permeable chamber wall on the side facing the yarn plug inside a friction surface made of wear-resistant material, in particular comprising a ceramic material having. In addition to the wear protection effect, the provision of such a material in this area also means that the gas-permeable wall is corrosion resistant and less susceptible to contamination. In particular, deposits of preparation residues can be avoided.

In addition, an embodiment of a delivery nozzle is described in WO 03/004743. The delivery nozzle comprises a base body and a plurality of spaced-apart guide inserts, which may advantageously be made of a ceramic material or provided with a corresponding coating. This ensures that the heavily loaded by the thread contact points and friction points are made of a wear-resistant material, so that a stable and uniform thread guidance and yarn delivery is achieved. In addition, the coefficients of friction between the thread and the contact points or friction points are considerably reduced.

The known device has been well proven, however, in connection with the objective of simply constructed devices that on the one hand have a long life and enable a uniform production of the yarn plug, more technical problems have emerged. As already can be seen from WO 03/004743, there was already the need to produce each of the areas of the devices contacted by the thread of a full ceramic. This is especially true for the delivery nozzle. The problem in this context is that the ceramic components of the device are joined together with other parts of the device. The cause of the technical problems is essentially the different thermal expansion behavior of ceramic and metal. The connection of ceramic components and metallic components thus presents a problem especially where large temperature fluctuations occur. In the present case, this applies in particular in the region of the delivery nozzle. In this area of the device, temperature fluctuations in the range of room temperature to about 300 ° C occur. At the same time a particularly high precision of the thread conveying or thread guide is required here, so that the position of the individual components to each other must be maintained exactly as far as possible during operation.

On this basis, it is an object of the present invention to provide means which at least partially solve the technical problems described with reference to the prior art or alleviate their disadvantages. In particular, components of a ceramic nozzle for the production of yarn plugs are to be proposed, which can be permanently and with high precision attached to metallic components, even if significant temperature fluctuations occur in the immediate vicinity. In addition, a device for Stauchkräuseln a synthetic multifilament yarn with improved wear protection with respect. The thread-guiding components should be specified.

These objects are achieved with a device for Stauchkräuseln a synthetic multifilament yarn having the features of claim 1 and of claim 17. Further advantageous embodiments of the invention are described in the respective dependent formulated claims. It should be noted that the features listed individually in the claims can be combined with each other in any technologically meaningful manner and lead to further embodiments of the invention.

The crimping apparatus of a synthetic multifilament yarn has a housing comprising metallic material. Furthermore, the device has formed at least one ceramic nozzle with at least two molded parts. At a Planar surface of each molded part is provided at least one recess for forming a nozzle channel. According to the invention, separate means for fixing to the housing are provided for each molded part, wherein the means comprise a positive fastening and an axial guide in a plane parallel to the plane surface:

By "housing" is meant in particular the adjacent to the ceramic nozzle or the moldings arranged component of such a device. This may be a one-piece embodiment of the housing may be provided, but preferably the housing is constructed in several parts, so that each housing receptacle is in contact with only one of the two moldings. The housing contacts the molded parts directly or via fastening means such as screws, pins, bolts, stop surfaces, etc. In particular, there is a spatial fixation or positioning of the molded parts with respect to this housing. The proposed fixation uses two different methods, on the one hand a positive fastening and on the other hand a guide along an axis. The form-liquid attachment ensures that close to this attachment point a relative movement between the housing and molded parts (with the exception of possibly a rotation) can take place to an insignificant extent, is preferably prevented. In contrast, the guide point with the axial guide to the fact that here a relative displacement of the housing relative to the molded part is allowed, so it can take place. In other words, this means that the positive fastening can be regarded as a reference point, which remains substantially unchanged during the operation of such a device, while the axial guide at least partially allows different distances to the positive fastening.

According to a particularly advantageous embodiment, the ceramic molded parts are joined together by pass means, such that both the Garnzuführkanal near an inlet of the ceramic nozzle and the adjoining nozzle channel in the assembled state have the highest possible precision. The exact position of the two ceramic molded parts in the housing, which comprises the ceramic molded parts and is formed at least partially from metallic material, is preferably also defined with the fitting means.

The molding for a ceramic nozzle has a peripheral surface and a flat surface, at least two holes are provided, which extend toward the peripheral surface. At least one recess for forming a nozzle channel is provided on the plane surface. The molding is made of ceramic material, preferably integrally formed. The production of the molding can be done, for example, with at least one of the production processes of pressing, sintering, grinding. By "molded part" is meant in particular one half of a ceramic nozzle, wherein the planar surface is to be regarded as the contact surface of the two molded parts.

By "peripheral surface" is meant, in particular, the other regions of the surface of the molded part which are not to be assigned to the planar surface, that is to say the surface which serves to abut a further ceramic molded article. The peripheral surface may have any contours, but preferably the peripheral surface is formed with substantially flat surfaces. Most preferably, the molded part substantially has a rectangular structure, wherein one of the two largest surfaces represents the planar surface. However, the molding may be equipped with special abutment surfaces, grooves, abutment edges, etc., to facilitate positioning relative to adjacent components.

According to an advantageous development of the device, at least one bore of the molded part with a rotationally asymmetric cross section is provided for the axial guidance. The holes listed here allow in particular a simple measure attachment of the ceramic molding to metallic components. With a first of the two holes, the position of the molding, in particular punctiform, fixed. Now, however, a second possibility for fixing the molding must be created, which prevents free rotation around the first bore. For this purpose, it is now proposed to provide a second bore which has a rotationally asymmetric cross section. This means, in particular, that the bore has a cross-section which has a greater extent in one direction than one or all deviating directions. With such a configuration of the second bore a kind of guidance is formed by the larger extent. If now a fastener positioned through this hole, it may, for example, due to the thermal expansion behavior, translationally move in the rotationally asymmetric cross section. This represents a particularly preferred possibility of designing a molded part in order to substantially alleviate the technical problems mentioned at the outset.

It should also be noted that the bores in certain embodiments can be designed as so-called "blind hole" holes, so extend only from the peripheral surface to the inner areas of the molding. However, preferred is the embodiment in which the bores extend from the peripheral surface to the plane surface. This makes it possible to make fixation of the molding on other components of the plane surface, whereby the assembly activity is significantly simplified.

According to a further embodiment of the molding, the at least one recess extends between two end faces of the molding and thus spaced apart the at least two holes. This means, in particular, that the recess extends over the entire length of the plane surface or of the molded part and thus divides it into two halves. According to this embodiment is now the first hole on one half and the second hole with rotationally asymmetric cross-section provided on the other half. In this way, the source of the occurring temperatures, namely the nozzle channel formed with the recess, positioned within the fixation or storage, whereby a more accurate positioning of the nozzle outlet is ensured even at high temperatures or large temperature fluctuations.

According to a further embodiment of the molded part, at least one chamber is provided on the plan side with a recess towards the at least one recess, wherein the one bore with rotationally asymmetrical cross section is arranged farther away from the chamber than the other bore. The chamber is advantageously also a connection between the flat surface and the peripheral surface and serves in particular the supply of the hot medium, such as steam or gas. In view of the fact that a fluid is to be supplied to the recess via this chamber, an exact connection of the chamber to the fluid-supplying components is required. With the embodiment proposed here, wherein the oblong hole bore is provided far away from the chamber, it is ensured that the smallest possible material displacements in the region of the chamber take place due to the thermal expansion. This ensures a relatively tight transition to the fluid-supplying components.

It is also proposed that the at least two bores comprise a borehole designed as a round hole and a borehole embodied as a slot. By "round hole" is meant essentially a cylindrical configuration of the wellbore. It serves for example for receiving a dowel pin, which also has a cylindrical shape. The bore preferably has a shape tolerance of less than 0.15 mm. By "slot" are meant such holes, which in each case have a semicircular shape in two opposite edge regions However, in the intermediate areas, however, have a substantially straight course. It is also possible in principle, instead of selecting semicircular end portions of other section shapes, for example, straight stop edges, oval shapes, etc. The advantage of an embodiment of the second hole as a slot is that here a guide for exactly one direction is specified. As a result, the behavior of the molded part during thermal cycling can be more accurately predicted or limited.

Furthermore, it is also proposed that the at least one recess has a center axis, and that a bore with the rotationally asymmetric cross section is designed as a slot hole having an extension axis, the center axis and the extension axis being parallel to one another. This has the particular effect that the slot hole allows different thermal expansion behavior of the adjacent component relative to the molded part in the direction of the nozzle channel. This has the advantage that the nozzle channel also in this case still opens flush in the downstream stuffer box and such consistent qualities with respect to the yarn plug over a wide temperature range is ensured near the ceramic nozzle.

Further, it is advantageous that the at least one ceramic nozzle is designed with two similar shaped parts, which lie with the flat surfaces so that the recesses form both mold parts together a nozzle channel with an inlet on a first end side and an outlet on a second end side. The nozzle channel is preferably formed in the direction of an axis, wherein this may have varying channel cross-sections. In particular, the nozzle channel has a larger channel cross-section near the outlet than in inner regions of the ceramic nozzle. In order to ensure the most uniform possible stress on both moldings, the recesses are designed so that the nozzle channel wall formed in equal parts by one molding each becomes. It is particularly preferred that the mold parts are arranged symmetrically with respect to a central axis, which corresponds in particular to the center axis, all recesses. This makes it possible that the variety of parts for the production of such ceramic nozzles can be significantly reduced, because so can always be the same moldings joined together.

Furthermore, it is also proposed that the shaped parts of the at least one ceramic nozzle each have two chambers with recesses toward the recesses, wherein together with one chamber each of a molded part a cavity and together with a recess of a molded part, a feed channel is formed. The cavity serves as a settling volume for an incoming conveying fluid, in particular a gas. The connections for the supply of the conveying fluid are advantageously provided only on one side of the ceramic nozzle, the other side of the recesses can be closed by adjacent components. Starting from the cavities, the delivery fluid flows via the supply channels into the nozzle channel, wherein in the region of the merging of supply channels and nozzle channel advantageously a widening of the channel cross-section or the nozzle channel is provided. The feed channels run at an acute angle to the nozzle channel, so that the inflowing conveying fluid already has a large velocity component in the direction of the center axis of the nozzle channel. In this way it is prevented that unwanted flow vortices are avoided in the deflection in the flow channel, which would lead to an uncontrolled delivery of the thread.

In this context, it is particularly advantageous that the form-fitting attachment each comprises a bore executed as a round hole, which extends at least partially into the molded part or in the housing, which are aligned with each other so that a dowel pin at least partially into both holes extends into it. The dowel pin has a substantial in this case cylindrical shape and lies with the vast majority of its peripheral surface in the holes on the material of the molding and the housing. Preferably, this dowel pin extends to near the flat surface of the molding, so that it is easy to remove if necessary.

According to a further embodiment, it is proposed that the axial guide comprises a hole executed as a slot in at least the molded part or the housing, which extends at least partially into the molded part or the housing, wherein a guide pin at least partially into the executed as a slot bore extends. Preference is given to the embodiment that in the molded part designed as a slot hole is provided, while the housing also has a hole running as a round hole. This has the consequence that the guide pin is arranged immovably to the housing but displaceable to the ceramic nozzle or the respective molded part. If it now comes to a thermal expansion of the housing made of metal, which is greater than the thermal expansion of the ceramic molding, the guide pin is guided in the hole running as a slot. Thus, a degree of freedom of movement for the connection housing / molded part is ensured, so that during operation, the different thermal expansion behavior can be compensated without jeopardizing the functionality of the ceramic nozzle or the device.

Furthermore, it is also proposed that the hole embodied as a slot has a maximum extent in the direction of an extension axis, wherein the maximum extent is at least 0.2 mm greater than a dimension of the guide pin. In particular, this maximum extent is dimensioned such that at the maximum temperature which can be reached during operation, there is still a play in the range of at least 0.05 mm. Basically, the maximum extent is selected with reference to the allowable displacement paths. Prefers is the hole designed as a hole at maximum temperature load in use (about 300 ° C) in the direction perpendicular to the maximum extent by at least 0.01 mm greater than the dimension of the guide pin in order not to hinder the relative movement by friction.

According to yet another embodiment of the device, at least the dowel pin or the guide pin comprises metallic material. Preferably, both the dowel pin and the guide pin are metallic. This ensures that they have a similar expansion behavior as the housing and thus fixed the position to the housing is invariably, a loosening of the attachment to the housing is thus avoided.

It is also advantageous that the housing is designed so that it presses the at least two molded parts of a ceramic nozzle with their flat surfaces sealingly against each other. This means, in particular, that the plane surfaces come to lie against one another in such a way that the fluids conveyed in the ceramic nozzle can not leave the nozzle channel and / or other cavities formed with the molded parts. Most preferably, the contact is made airtight, especially even if the prevailing overpressure operating in the nozzle channel. In this case, the mold parts for forming a ceramic nozzle are advantageously not directly inseparably or detachably connected to each other, but are pressed against each other during use only with their plane surfaces. Thus, in particular non-positive screw for clamping the two mold parts are no longer required. The shaped parts are preferably formed as flat plates. At the same time complex and time-consuming Feinstbearbeitungen the flat surfaces can be avoided in the production of moldings.

The channels, cavities, etc. located in the interior of the ceramic nozzle are preferably formed in equal parts in each case with the molded parts. Thus, the plane surface preferably also represents a contact surface during operation, wherein the two plane surfaces abut predominantly on each other.

According to a further embodiment of the device, at least one ceramic nozzle is positively positioned with its outlet to a thread entry of a downstream in the direction of thread compression box. In other words, this means that a positive stop or contact is provided in the axial direction or in the direction of the nozzle or plug channel. The positive connection is preferably provided by self-centering mold elements of the ceramic nozzle and the stuffer box, such as conical or conical shapes of outlet and / or thread entry. To ensure a permanent positive connection, the ceramic nozzle and stuffer box can be clamped with connection means outside the area with positive locking.

It is preferred that the thread entry comprises at least in the region of the positive contact ceramic material. This is e.g. ensures that the plug always comes into contact only with very resistant, wear-resistant material, which significantly extends the service life and ensures good yarn quality over a long period of time.

In addition, it is also proposed that the outlet is formed with a nozzle tip having a first mating surface and the thread inlet having an input portion having a second mating surface, wherein the first mating surface contacts the second mating surface. The first mating surfaces are preferably formed with two moldings. The first and the second mating surfaces are formed, for example, in a section in the manner of a cone, so that the nozzle tip or the nozzle channel is centered during assembly of the device for Stauchkräuseln and opens in alignment with the thread inlet.

The nozzle channel of the ceramic nozzle preferably passes directly into the plug channel of the stuffer box. By "direct" is meant that there is no substantial offset or gap between the two treatment channels, but an immediate transition is created.

According to a further aspect of the invention, there is proposed an apparatus for upset crimping of a synthetic multifilament yarn, which is designed with a split ceramic nozzle (as a delivery nozzle) and a downstream stuffer box. In this case, the ceramic nozzle has at least one Garnzufiihrkanal and at least one Düsenauslasskanal. The device is characterized in that the ceramic nozzle comprises a divided nozzle body with two mold parts, which are formed as flat plates.

By "Garnzuführkanal" is the part of a nozzle channel to understand in which the filaments are not subjected to any thread treatment within the ceramic or delivery nozzle. The area of the nozzle channel within which the filaments are treated up to the outlet is described here as "nozzle outlet channel". The "nozzle body" describes in particular two joined moldings, so that the channels are limited by these. With a "plate-shaped" structure is superficially meant that these are not performed with half cylinders, but the flat surfaces in substantially flat and preferably also (nearly) opposite circumferential surfaces. "Flat" are the plate-shaped moldings, especially if they have a height of less than 10 mm, preferably the height is in a range of 6.0 mm [millimeter] to 4.0 mm.

Further, it is also proposed that each of the two mold parts is installed in two housing halves, wherein superimposed flat surfaces of the molded parts form sealing surfaces. In this case, it is particularly preferred that the two molded parts are joined together by means of a pass agent, in particular also inserted into the housing halves. By "pass means" is meant in particular the above-described means for positive fastening and for axial guidance in a plane parallel to the plane surface.

Moreover, it is particularly advantageous that the two mold parts are formed substantially symmetrical, each half having at least one Garnzuführkanal, at least one air supply duct and at least one Düsenauslasskanal, which are embedded in corresponding planar surfaces of the moldings, wherein the plane surfaces in the assembled state, the channels airtight limit , With "air supply channel" is particularly described a channel through which a fluid is introduced into the Garnzuführkanal, which ultimately also serves to treat the filaments. Usually, the mouth of the air feed channel into the nozzle channel is a delimitation of Garnzuführkanal and Düsenauslasskanal. Preferably, two air supply channels, which lead with an acute angle in the nozzle channel.

By way of clarification, it should be understood that the two aspects of the invention, individually or in combination with each other, provide significant improvements in the device with respect to the production of yarn plugs with high precision, even if significant temperature fluctuations occur in the vicinity of the delivery nozzle. Furthermore, the embodiments of the devices for Stauchkräuseln a synthetic multifilament yarn on a significantly improved wear protection with respect to the thread-guiding components.

Figur 1

einen Teil einer erfindungsgemäßen Vorrichtung in Explosionsdarstellung;

Figur 2

ein weiteres Ausführungsbeispiel eines Teils einer erfindungsgemäßen Vorrichtung,

Figur 3

einen Schnitt durch ein anderes Ausführungsbeispiel der erfindungsgemäßen Vorrichtung,

Figur 4

schematisch den Aufbau einer Vorrichtung zum Stauchkräuseln eines multifilen Fadens mit einer Variante der Keramikdüse, und

Figur 5

eine Variante einer Keramikdüse mit einer Stauchkammer, und

Figur 6

ein Detail der in Figur 5 gezeigten Stauchkammer.

The invention will be explained below with reference to the figures together with the technical environment. The figures show particularly preferred embodiments of the invention, but this is not limited thereto. Show it:

FIG. 1

a part of a device according to the invention in an exploded view;

FIG. 2

a further embodiment of a part of a device according to the invention,

FIG. 3

a section through another embodiment of the device according to the invention,

FIG. 4

schematically the structure of a device for upsetting crimping a multifilament yarn with a variant of the ceramic nozzle, and

FIG. 5

a variant of a ceramic nozzle with a stuffer box, and

FIG. 6

a detail of the stuffer box shown in Figure 5.

The figures comprise a schematic and not detailed representation of the embodiments of the invention, so that in particular conclusions about the dimensions are not readily derivable.

Figure 1 shows schematically, in perspective and in an exploded view, a ceramic molding 1 with an associated housing 22 and the necessary means for fixing the molding. 1

The ceramic molded part 1 has a peripheral surface 3, a flat surface 4 and two end surfaces 9 (which are assigned to the peripheral surface 3) as a surface. For each molded part 1 at least two holes 5 are provided, each extending to a peripheral surface 3. In the flat surface 4 holes 5, chambers 10, recesses 11 and recesses 6 are formed. The arrangement of the chambers 10 and recesses 11 is symmetrical to the recess 6, wherein the chambers 10 are designed as a passage through the molded part 1. The recess 6 extends along a center axis 12 between the two end faces 9, wherein in each case a chamber 10 and a recess 11 are arranged mirror-symmetrically to the center axis 12.

Furthermore, the molded part 1 has two holes 5, wherein one is designed as a round hole and has a diameter 27, while another hole 5 as (exaggerated drawn) slot has an asymmetrical cross section 8 and an extension axis 13. These two holes 5 also extend through the molded part 1, so that the fastening means can be inserted therethrough. The hole 5 shown in Figure 1 at the top right, which is designed as a round hole, serves to receive the dowel pin 26 with the thickness 28, which corresponds at least to the diameter 27 of the bore 5.

The oblong bore shown exaggerated at the bottom left serves to receive a guide pin 29 with its dimension 31. This bore 5 with the rotationally asymmetric cross section 8 has an extension 30 in the direction of the extension axis 13, which is significantly larger than the dimension 31 of the guide pin 29.

In this way, two different means for fixing the molded part 1 are indicated on the housing 22, namely on the one hand a positive fastening and on the other hand an axial guide.

The dowel pin 26 and the guide pin 29 extends through the molded part 1 and is fastened in corresponding bores 5 of the housing 22 designed as a round hole. In addition, the housing 22 in sections forms receptacles that (relatively loosely) come close to the peripheral surface 3 of the molded part 1 to the plant.

While the dowel pin 26 and the guide pin 29 provide a fixation of the molding 1 with respect to the housing 22 in a plane 25 parallel to the planar surface 4, to prevent the lifting of the molded part 1 from the housing 22 further fastening means for fixing in the Z direction, ie perpendicular to the described level 25, provided. These are realized by means of metallic screws 32 which are retractable in the flat surface 4 of the molded part 1. The holes required for this purpose are significantly larger than the screw shaft formed, so that these screws 32 perceive no guidance or fixation in the plane 25 parallel to the plane surface 4. Only the contact formation of the screw head with a shoulder in the bore ensures the fixation in the Z direction.

Figure 2 shows schematically and in perspective the joined state of a housing 22 and a molded part 1. This is in particular also half of a ceramic nozzle 2. The recesses 6 then form together with the nozzle channel 7, an inlet 15 near a first end face 17 and a Outlet 16 near a second end face 18 has. The nozzle channel 7 comprises a Garnzuführkanal 58 and a nozzle outlet channel 59, which are delimited by the mouth of the two air supply channels 62. The recess 6 spaced in the illustrated embodiment, the positive fastening 23 and the axial guide 24, which ensure a fixation of the molded part 1 with respect to the housing 22 in a plane 25 parallel to planar surface 4. Vertical to ensure screws 32 for the required contact pressure of the molded part 1 on the housing 22 at least during the cold state of the ceramic nozzle 2 and / or repair measures or the removed state. During operation, it is preferred that the metallic screws 32 behave such that they have a negligible contact with the molding 1. The fixation in the Z direction then takes place via the other, pressed-on molding 1.

In the embodiment variant shown here, the axial guide 24 is in turn shown with a bore 5 (shown clearly exaggerated) as a slot. The bore 5 has a maximum extent 30 in the direction of the extension axis 13.

FIG. 3 shows a part of a device for producing a crimping thread, wherein a plurality of ceramic nozzles 22 are held next to one another in a nozzle plate 33. The ceramic nozzle 2 is formed with two housing halves 60 or receptacles of a housing 22 and two molded parts 1. The moldings 1 are each designed as a flat plate with a height 63 in a range of about 4.0 to 6.0 mm. The moldings 1 rest against one another on their plane surface 4, thereby defining a plane 25 and a sealing surface 61 which effects an airtight limitation of the nozzle channel 7. The required contact pressure is realized via the housing halves 60 of the housing 22, which do not touch each other in order to ensure a uniform contact pressure of the two molded parts 1. In the center of the ceramic nozzle 2, the nozzle channel 7 can be seen.

Figure 4 shows schematically an embodiment of the device 21 according to the invention for Stauchkräuseln a synthetic multifilament yarn in cross section. The device consists of a ceramic nozzle 2 and a stuffer box 37 downstream of the ceramic nozzle 2. The ceramic nozzle 2 contains a nozzle channel 7 which forms an inlet 15 at one end and an outlet 16 at the opposite end. The ceramic nozzle 2 is connected by a line 38 to a pressure source 4 (not shown here). By feed channels 20 and cavities 19, the line 38 is connected to the nozzle channel 7. The entry of the hot, pressurized conveying fluid is realized by a plurality of cavities 19, so that the conveying fluid in the yarn running direction, which is indicated by the arrows, the nozzle channel 7 is supplied. With the outlet 16 of the nozzle channel 7 opens into a plug channel 40 of the stuffer box 37th

The ceramic nozzle 2 now receives near the inlet 15 a thread 14, which is moved along the nozzle channel 7. For fixing the molded part 1 to a housing (not shown), a form-liquid attachment and an axial guide are formed by correspondingly shaped bores 5.

The stuffer box 37 is formed by a ceramic nozzle 2 facing first portion 35 with a thread inlet 39 and a first portion 35 downstream second portion 36 with a stopper outlet 46. In the first section 35, a plug channel 40 is formed by a gas-permeable chamber wall having a friction surface 43. The gas-permeable chamber wall contains a multiplicity of lamellae 44, which are annularly arranged at a small distance from one another. The lamellae 44 are held by a holder 34 provided for this purpose at the upper end of the first section 35 and by a further holder 34 at the lower end of the first section 35. The fins 44 and the brackets 34 are disposed within an enclosure formed with a wall 41, wherein the wall 41 is closed to the outside and is connected only through an opening 42 with a suction (not shown).

On the side facing the thread plug 45, the lamellae 44 each have a friction surface 43. The lamellae 44 are preferably made of a ceramic material, so that the friction surfaces 43 are made of a low-lube material.

Below the gas-permeable chamber wall, a closed wall 41 is provided which forms a plug channel 40. The plug channel 40 in the second section 36 is made larger in diameter than the plug channel 40 inside the first portion 35 with the gas-permeable chamber wall. The plug channel 40 in the second section 36 forms the plug outlet 46 at its end.

The illustrated in the figure 1 embodiment of the device according to the invention is shown with a threadline to illustrate the function of the device. In this case, the yarn 14 is conveyed through the ceramic nozzle 2 into the nozzle channel 7 by a delivery fluid supplied via the supply channels 20. The thread 14 enters via the inlet 15 in the nozzle channel 7 a. The conveying fluid used is preferably hot air or a hot gas. Due to the high-speed fluid flowing the Fadem 14 is conveyed at high speed to the stuffer box 37. In this case, a thread plug 45 is formed in the plug channel 40. The thread 14, which consists of a plurality of filaments, is deposited on the surface of the yarn plug 45, so that the filaments form loops and bows. The conveying fluid is sucked through between the fins 44 through the opening 42. The thread stopper 45 forming in the stopper channel 40 bears against the friction surfaces 43 of the lamellae 44. The frictional forces and the delivery pressure of the delivery fluid acting on the thread stopper 45 are substantially in equilibrium, so that the yarn end diameter inside the stopper channel 40 remains essentially the same. Since the lamellae 44 are formed of a ceramic material, the force equilibrium acting on the yarn stopper 45 is maintained essentially by keeping the pressure of the delivery fluid constant. The yarn plug 45 now enters the second portion 36 of the stuffer box 37, which is formed by a closed wall 41. The closed wall 41 in the second section 36, which may be formed, for example, as a tube, serves only to guide the yarn plug 45 and to a downstream, not shown, cooling device. Here, the plug channel 40 is formed larger in the region of the second portion 36 than the plug channel 40 in the region of the first portion 35, so that only slight frictional forces act on the thread plug 45 in the second section 36. Wear protection is therefore unnecessary.

FIG. 5 shows schematically at the top a variant of the ceramic nozzle 2 and below the stuffer box 37 with the upper part of the first section 35.

FIG. 5 shows the bipartite nature of the ceramic nozzle 2 with the plane surfaces 4 and the fitting means (round bore 5 and dowel pin 26 and bore with unsymmetrical cross section 8 and guide pin 29), via which in particular the two ceramic molded parts 1 are exactly parallel to the housing (not shown) ) are aligned and fixed.

The ceramic nozzle 2 is positively positioned with its outlet 16 to a thread inlet 39 of a downstream in the direction of thread flow 57 stuffer box 37. So that the center axes 12 of the ceramic nozzle 2 and the stuffer box 37 in the assembled state coincide and no interruption of the ceramic friction between the nozzle channel 7 and the plug channel 40 is formed, both moldings 1 on a common nozzle tip 50, which is inserted into an input section 51. Such an input section 51 may be formed, for example, in a holder 34 of the stuffer box 37. Corresponding first fitting surfaces 52 on the nozzle tip 50 and second fitting surfaces 53 on the input section 51 center the ceramic nozzle 2 with respect to the stuffer box 37. The first and second connecting surfaces 54, 55 position the ceramic nozzle 2 exactly with respect to the stuffer box 37. The nozzle channel 7 the ceramic nozzle 2 passes directly into the stopper channel 40 of the stuffer box 37, which is designed with lamellae 44 (see detail in Fig. 6).

In FIG. 5, the ceramic parts are highlighted in double diagonal hatching. Via connecting means 56, the housing 22 of the ceramic nozzle 2 is attached to the stuffer box wall. However, it is also possible to attach the ceramic nozzle 2 with special connecting means 56, such as a bayonet lock, to the stuffer box 37.

The new invention proposes a ceramic nozzle for a device for crimping a synthetic multifilament yarn. The ceramic nozzle 2 has a divided nozzle body, consisting of two ceramic moldings. The ceramic moldings are preferably formed as two flat plates and assembled precisely over fitting. The ceramic moldings abut each other over their two planar surfaces and together form a nozzle tip, which projects into the plug channel and together delimit the entire channel with ceramic. A particular advantage of each enclosed in a metal housing half flat ceramic plate is also in an optimal protection against mechanical damage.

LIST OF REFERENCE NUMBERS

1

molding

2

ceramic nozzle

3

peripheral surface

4

plane surface

5

drilling

6

recess

7

nozzle channel

8th

cross-section

9

face

10

chamber

11

deepening

12

central axis

13

extension axis

14

thread

fifteen

inlet

16

outlet

17

First front page

18

Second front side

19

cavity

20

feed

21

contraption

22

casing

23

attachment

24

axial guidance

25

level

26

dowel

27

diameter

28

thickness

29

guide pin

30

expansion

31

dimension

32

screw

33

nozzle plate

34

bracket

35

first section

36

second part

37

stuffer

3 8

management

39

thread entry

40

plug channel

41

wall

42

opening

43

friction surface

44

lamella

45

yarn plug

46

plug outlet

50

nozzle tip

51

input section

52

first mating surface

53

second mating surface

54

first connection surface

55

second interface

56

connecting means

57

Thread running direction

58

yarn feed

59

nozzle outlet

60

housing half

61

sealing surface

62

air supply duct

63

height

Claims (20)

Apparatus (21) for crimping a synthetic multifilament yarn (14) comprising a housing (22) comprising metallic material and at least one ceramic nozzle (2) formed with at least two moldings (1), wherein on a plane surface (4) of each molding (1) at least one recess (6) for forming a nozzle channel (7) is provided, characterized in that separate means for fixing to the housing (22) are provided for each molded part (1), wherein the means a positive fastening (23 ) and an axial guide (24) in a plane (25) parallel to the plane surface (4). The apparatus (21) according to claim 1, characterized in that the molding (1) is provided with a rotationally asymmetric cross section (8) provided for the axial guidance (24) at least one drilling (5). Device (21) according to claim 1 or 2, characterized in that extending the at least one recess (6) between two end faces (9) of the molding (1) and the at least two holes (5) of the molding (1) spaced from each other. Device (21) according to claim 2 or 3, characterized in that on the plane surface (4) of the molded part (1) at least one chamber (10) is provided with a recess (11) towards the at least one recess (6), wherein the one bore (5) with the rotationally asymmetric cross section (8) further away from the chamber (10) than the other bore (5). Device (21) according to one of claims 2 to 4, characterized in that the at least one recess (6) of the molded part (1) has a center axis (12) and the one bore (5) with the rotationally asymmetric cross section (8) as a slot Bore having an extension axis (13) is executed, wherein the center axis (12) and the extension axis (13) are parallel to each other. Device (21) according to any one of the preceding claims, characterized in that the at least one ceramic nozzle (2) is designed with two similar shaped parts (7) which abut with the plane surfaces (4) such that the recesses (6) form a nozzle channel (7). 7) with an inlet (15) on a first end face (17) and an outlet (16) on a second end face (18). Device (21) according to claim 6, characterized in that the shaped parts (1) of the at least one ceramic nozzle (2) each have two chambers (10) with recesses (11) to the recesses (6), wherein together with one chamber (10) of a molded part (1), a cavity (19) and together with a respective recess (11) of a molded part (1), a feed channel (20) is formed. Device (21) according to any one of the preceding claims, characterized in that the positive fastening (23) each comprise a hole (5) designed as a round hole, which extends at least partially into the molded part (1) or into the housing (22), these are so to each other are aligned, that a dowel pin (26) extends at least partially into both holes (5). The apparatus (21) according to one of the preceding claims, characterized in that the axial guide (24) the mold part (1) or the housing (22) comprises a running as an elongated hole bore (5) in at least extending at least partially into the shaped part ( 1) or the housing (22) extends, wherein a guide pin (29) extends at least partially into the elongated hole running hole (5). Device (21) according to claim 9, characterized in that the bore (5) designed as a slot has a maximum extent (30) in the direction of an extension axis (13), wherein the maximum extent (30) is at least 0.2 mm larger than a dimension (31) of the guide pin (29). Device (21) according to one of claims 8 to 10, characterized in that at least the dowel pin (26) or the guide pin (29) comprises metallic material. Device (21) according to any one of the preceding claims, characterized in that the housing (22) is designed so that this presses the at least two mold parts (1) of a ceramic nozzle (2) with their flat surfaces (4) sealingly together. Device (21) according to any one of the preceding claims, characterized in that at least one ceramic nozzle (2) with its outlet (16) to a thread inlet (39) of a downstream in the thread running direction (57) compression chamber (37) is positively positioned. Device (21) according to claim 13, characterized in that the thread entry (39) comprises at least in the region of the positive contact ceramic material. Device (21) according to claim 13 or 14, characterized in that the outlet (16) with a nozzle tip (50) having a first mating surface (52) and the thread inlet (39) having an input portion (51) having a second mating surface (53 ), wherein the first fitting surface (52) contacts the second fitting surface (53). Device (21) according to any one of claims 13 to 14, characterized in that the nozzle channel (7) of the ceramic nozzle (2) passes directly into the plug channel (40) of the stuffer box (37). Means (21) for stuffer box crimping a synthetic multifilament yarn (14) with a divided ceramic nozzle (2) and a downstream compression chamber (37), wherein the ceramic nozzle (2) at least (58) and at least one nozzle outlet (59) having a yarn feed characterized characterized in that the ceramic nozzle (2) comprises a divided nozzle body with two mold parts (1), which are formed as flat plates. Apparatus (21) according to claim 17, characterized in that each of the two mold parts (1) are installed in two housing halves (60), wherein the superimposed flat surfaces (4) of the molded parts (1) form sealing surfaces (61). Device (21) according to claim 17 or 18, characterized in that the two molded parts (1) are joined together by means of a pass-through means (5, 26, 29; 23, 24), in particular also in the housing halves (60). Apparatus (21) according to any one of claims 17 to 19, characterized in that the two mold parts (1) are formed substantially symmetrical, each halve at least one Garnzuführkanal (58), at least one air supply duct (62) and at least one Düsenauslasskanal (59). have, which are embedded in corresponding planar surfaces (4) of the molded parts (1), wherein in the assembled state, the flat surfaces (4), the channels (58, 59, 62) airtight limit.

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