Spinning station of an air-jet spinning machine and method for cleaning a yarn forming element

Abstract

The invention relates to a cleaning device for a yarn-forming element of an air-jet spinning nozzle, a spinning station of an air-jet spinning machine, and a method for cleaning such a yarn-forming element. To provide a spinning station of an air-jet spinning machine and a method for cleaning a yarn-forming element of an air-jet spinning machine that enable long and trouble-free operation with consistent quality and strength of the produced yarn, the cleaning device comprises a cleaning ribbon and a storage unit for providing and retracting the cleaning ribbon, wherein a fixed end of the cleaning ribbon is fixed to the storage unit and a free end of the cleaning ribbon is available for cleaning and retractable after cleaning.In addition, the cleaning device has a cleaning tape guide for feeding the free end of the cleaning tape to the yarn forming element of the air spinning nozzle for mechanical cleaning.

Description

[0001] The invention relates to a spinning station of an air-jet spinning machine with a cleaning device for a yarn-forming element and a method for cleaning such a yarn-forming element.

[0002] In general, air-jet spinning involves drawing a sliver to a defined yarn count using a multi-roller drafting system, depending on the desired yarn count, and then feeding it to an air-jet spinneret. Within a swirl chamber of the air-jet spinneret, the outer fibers of the sliver are wound around an inner fiber core by means of a swirling air flow generated by air jets in the area of ​​an inlet opening of a yarn-forming element of the air-jet spinneret. This results in an air-jet-specific yarn structure with a parallel yarn core and wrapped fibers arranged at a specific angle. The wrapped fibers are crucial for the desired strength of the yarn. There are clear limits to the number of fibers required in the cross-section to achieve sufficient strength, which is why conventionally spun air-jet yarns typically have a count range of Ne 20–50.

[0003] The air-jet spinning process can generally be carried out with fibers made of various materials, including natural fibers such as cotton and / or animal wool, and synthetic fibers such as polyester, as well as blends of natural and synthetic fibers. In practice, spinning with a high proportion of polymer fibers, particularly polyester (PES) fibers, often results in deposits of polymer residues, polyester fiber fragments, and / or finishing agents on the surface of a spinning cone of the yarn-forming element. However, such deposits significantly disrupt the air-jet spinning process and significantly reduce the spinning result and thus the yarn quality. In particular, thread breakage can occur during the spinning process due to the increased friction between the surfaces of the air-jet spinneret and the fibers.In addition, the air jets and other components of the air spinneret can become clogged with deposits, resulting in lower yarn strength and quality. Such deposits also adversely limit the possible spinning range.

[0004] EP2767625A1 discloses a method for cleaning a yarn forming element of an air spinneret with an additive.

[0005] The invention is therefore based on the object of providing a spinning station of an air-jet spinning machine and a method for cleaning a yarn-forming element of an air-jet spinneret, which enable particularly long and trouble-free operation with consistent quality and strength of the yarn produced.

[0006] The object is achieved according to the invention by a spinning station of an air-jet spinning machine according to claim 1 and a method for cleaning a yarn-forming element of an air-jet spinneret according to claim 6. Advantageous developments of the invention are specified in the dependent claims.

[0007] The spinning station of an air-jet spinning machine according to the invention has a feed for a fiber sliver to an air-jet spinneret, the air-jet spinneret with a fiber sliver inlet for the inlet of the fed fiber sliver into the air-jet spinneret, a vortex chamber arranged inside the air-jet spinneret for generating a vortex air flow by means of at least one vortex air nozzle opening into the vortex chamber, at least one yarn-forming element arranged inside the vortex chamber for producing a yarn from the fiber sliver fed into the vortex chamber of the air-jet spinneret via an outlet of the fiber sliver inlet, a withdrawal channel extending through the yarn-forming element for withdrawing the air-jet spun yarn, and a cleaning device.

[0008] The cleaning device encompassed by the spinning station has a cleaning ribbon and a storage unit for providing and retracting the cleaning ribbon. A fixed end of the cleaning ribbon is secured to the storage unit, in particular detachably and fixably for replacing the cleaning ribbon, and a free end of the cleaning ribbon is provided for cleaning the yarn-forming element, in particular unrollable, and can be retracted again after cleaning, in particular rolled up. Furthermore, the cleaning device has a cleaning ribbon guide for feeding the free end of the cleaning ribbon for mechanically cleaning a surface of the yarn-forming element of the air spinneret.

[0009] Furthermore, the fixed end is preferably mounted so as to be rotatable about an extension axis of the cleaning ribbon. This prevents undesirably strong twisting of the cleaning ribbon, which propagates as a result of the free end being guided multiple times around the yarn-forming element. The rotatably mounted fixed end therefore passively rotates with a delay as the twisting forces acting on the cleaning ribbon propagate. Alternatively or additionally, an active rotation of the fixed end about the extension axis of the cleaning ribbon can be provided by means of a rotary drive in order to enable a controlled, defined, in particular identical, co-rotation of the fixed end corresponding to the movement of the free end, whereby the twisting forces can be reduced as needed.

[0010] In the method according to the invention for cleaning a yarn forming element of an air spinneret, in particular a surface of a yarn forming element, first a free end of a cleaning ribbon is fed from a cleaning device through a withdrawal channel of a yarn forming element into the swirl chamber of the air spinneret, in particular to an outlet of a sliver inlet leading into the swirl chamber, via which outlet the sliver is introduced into the air spinneret and into the swirl chamber, and then a swirling air flow is generated in the swirl chamber by means of at least one swirling air nozzle opening into the swirl chamber in order to guide the cleaning ribbon, in particular multiple times, over a surface at least at the tip of the yarn forming element and / or over at least one nozzle opening of the swirling air nozzle and / or over a surface of the withdrawal channel in order to clean the corresponding areas.Finally, after the cleaning process, the cleaning ribbon is pulled back through the exhaust channel towards or to the cleaning device, preferably into the cleaning device.

[0011] By means of the proposed spinning station with the cleaning device and the proposed method, a mechanical cleaning of components inside the vortex chamber of an air spinneret can be carried out in a particularly simple manner, wherein it is particularly advantageous that it is not necessary to open the air spinneret, so that the cleaning can be carried out particularly quickly and without disruption.

[0012] An air-jet spinneret is understood to be any spinneret that uses at least one air stream to swirl fibers, particularly wrapped fibers, around an internal fiber core into a thread or yarn. The yarn formation process takes place in the region of a swirl chamber of the air-jet spinneret, in which at least one yarn-forming element is arranged. The air-jet spinneret is surrounded by a spinning station, with each spinning station serving to produce a yarn from a fiber sliver fed to the air-jet spinneret of the spinning station.

[0013] The air-jet spinneret has a feed and an inlet for the fiber sliver. Furthermore, the air-jet spinneret has an internal swirl chamber, one or more yarn-forming or spinning elements arranged at least partially within the swirl chamber, and an outlet for the air-jet spun yarn produced inside the swirl chamber. The outlet is preferably formed as a withdrawal channel that completely penetrates the yarn-forming element. The withdrawal channel is preferably arranged partially by the yarn-forming element and a yarn channel adjoining the yarn-forming element in the withdrawal direction of the air-jet spun yarn, or is formed exclusively by the yarn-forming element.

[0014] In addition, a plurality of vortex air nozzles opening into the vortex chamber are preferably arranged on the air spinneret, which are particularly preferably in fluid communication with at least one air supply line, wherein, during operation of the air spinning machine, compressed air provided by the air supply line flows into the vortex chamber via the air nozzles. The vortex air nozzle is or are arranged in a known manner to generate a vortex air flow within the vortex chamber for air spinning the fiber sliver into a yarn. In this case, the vortex chamber is located behind the fiber sliver inlet in the transport direction of the fiber sliver, or the fiber sliver inlet forms a feed opening or an outlet for the fiber sliver to be fed to the vortex chamber on a side facing the vortex chamber.

[0015] A yarn or thread within the meaning of the invention is a fiber strand in which at least some of the fibers are wound around an internal fiber core. A yarn can also be a roving or sliver for further processing, for example, using a ring spinning machine. The fiber strand and thus the yarn produced therefrom are preferably formed at least partially, particularly preferably entirely, from synthetic fibers or chemical fibers, for example, from polyester or polyethersulfone.

[0016] The sliver is essentially the fiber material fed into the air-jet spinning process, preferably provided as a coherent sliver or composite of fibers to be spun. All fibers can be made of the same material, or the sliver can contain chemically different fibers. However, the fibers in the sliver are generally not yet spun together.

[0017] The yarn-forming element can be a standalone component, a section of a structural unit, or a functional unit directly involved in the air-jet spinning process. The yarn-forming element can be formed in one piece or in multiple pieces. The yarn-forming element preferably comprises a spinning cone or part of a spinning cone. Most preferably, the yarn-forming element forms the spinning cone. During the air-jet spinning process, the yarn-forming element comes into direct contact, at least in sections, with the fibers to be spun to produce the yarn, as well as with the spun yarn.

[0018] A cleaning device is basically any device by means of which a yarn-forming element of an air-jet spinneret of an air-jet spinning machine can be mechanically cleaned. The mechanical cleaning preferably involves mechanically rubbing the surface to be cleaned inside the air-jet spinneret using the cleaning ribbon. However, the mechanical cleaning can also be additionally supported by a chemical cleaning medium, preferably a cleaning fluid, and particularly preferably an aqueous cleaning solution, on the cleaning ribbon. It is also conceivable to introduce a suitable chemical cleaning medium, in particular a cleaning fluid, into the vortex chamber and, in particular, onto the surfaces to be cleaned to support the mechanical cleaning by the cleaning ribbon.

[0019] The cleaning ribbon can, in principle, have any length, any diameter, and any chemical composition, as long as the cleaning ribbon can still be guided to the surface of the air spinneret to be cleaned and is suitable for cleaning. The cleaning ribbon is preferably at least 10%, particularly preferably at least 50%, very particularly preferably at least 100%, and especially preferably at least 200% longer than the distance between the storage unit of the cleaning device and the furthest surface to be cleaned, so that even if the cleaning ribbon becomes worn, particularly in the area of ​​the tip of the cleaning ribbon, complete cleaning is still possible.

[0020] The cleaning ribbon is preferably formed from a fiber material and / or has a rough surface to assist mechanical cleaning. Furthermore, the cleaning ribbon is flexible enough that the end of the cleaning ribbon inserted into the air spinneret for cleaning can be moved, in particular repeatedly, over the surfaces of the air spinneret to be cleaned, in particular the yarn-forming element and / or a nozzle orifice of the swirling air nozzle, due to the swirling air flow. Particularly preferably, the cleaning ribbon is formed such that it can be guided, in particular repeatedly, over a spinning cone tip, over at least one nozzle orifice of the swirling air nozzle, and / or over a surface of a discharge channel by means of the swirling air flow.

[0021] Furthermore, the free end of the cleaning ribbon preferably forms a fiber bundle, particularly upon or after exposure to fluidized air and / or moisture. This allows the free end to be fanned out with several individual fiber ends in the fluidized chamber, enabling effective cleaning. The moisture required for fanning can be supplied, for example, via the fluidized air nozzle. The individualizable fiber ends can be twisted or glued together before being fed into the fluidized chamber, whereby the holding forces for fanning out can be dissolved by the fluidized air and / or moisture.

[0022] The storage unit is initially any component or assembly for storing the drawn-in cleaning ribbon during operation of the spinning station or the air-jet spinning machine outside of a cleaning process. The storage unit can have a closed housing and / or be a self-contained unit. In principle, however, the storage unit can also be integrated into another device or unit of the air-jet spinning machine and in particular the spinning station. In this case, the cleaning ribbon is preferably stored in a rolled-up state. Although it is also conceivable in principle for several cleaning ribbons to be stored in one storage unit, it is preferred that each storage unit contain exactly one cleaning ribbon.

[0023] To enable cleaning, the cleaning ribbon is provided from the storage unit and subsequently retracted. In particular, the provision can take place actively by means of a drive device or, preferably, passively by grasping and pulling on one end of the cleaning ribbon by means of another device at the spinning station, at the air-jet spinning machine or at a service unit serving the spinning station and / or by means of a targeted air stream. For cleaning, the cleaning ribbon is preferably pulled out or moved at least as far as the surface to be cleaned that is furthest away from the storage unit of the cleaning device. The retraction can also preferably take place actively by means of a drive device or, in particular, by means of a spring that is tensioned during provision. However, passive retraction due to gravity or an externally applied air stream is also conceivable.However, active retraction is preferred.

[0024] The storage unit can, in particular, be equipped with a device for connecting the separated fiber ends of the free end during the drawing-in process. For example, a twisting device can be provided, which twists the fiber bundle and thus restores a compact free end made up of individual fiber ends connected to one another by holding forces, allowing for easy re-insertion into the withdrawal channel. Alternatively or additionally, the device can comprise a means for moistening the separated fiber ends and a means for compacting the moistened individual fiber ends into the compact free end.

[0025] A cleaning ribbon guide is understood to mean any means and device that helps the cleaning ribbon reach or be fed from the storage unit or after leaving the storage unit to the air-jet spinneret and in particular into the interior of the air-jet spinneret. The cleaning ribbon guide can be formed as a single component or as a multi-piece assembly. The cleaning ribbon guide can also be formed by further components of an air-jet spinning machine, in particular by further components of a spinning station of an air-jet spinning machine, or by components of the service unit serving the spinning station. Furthermore, the cleaning ribbon guide can also be understood functionally and thus be any means for guiding the cleaning ribbon with a free end to the yarn formation element to be cleaned.

[0026] A service unit is understood to mean any conventional device or apparatus which can move along the plurality of spinning stations, in particular those arranged in series, of at least one air-jet spinning machine in order to carry out supporting thread handling and / or maintenance or service activities at a respective spinning station if required.

[0027] In a preferred embodiment of the cleaning device, the storage unit has a storage reel for unwinding and rewinding the cleaning ribbon. The fixed end of the cleaning ribbon is preferably secured to the storage reel, allowing the cleaning ribbon to be wound and unwound particularly easily and without the risk of knots or loops forming. Furthermore, the storage reel, with a cleaning ribbon located thereon, is preferably removable from the storage unit, allowing the cleaning ribbon to be easily replaced and / or replaced.

[0028] According to an advantageous development of the cleaning device, the storage unit and in particular the storage coil are connected to an automatic and / or motorized drive unit for the controlled provision and / or retraction of the free end of the cleaning ribbon, thereby enabling active control in a particularly simple manner. The drive unit can be operated electrically and / or pneumatically. The drive unit is preferably a motor, although direct drive by means of at least one air stream is also conceivable.

[0029] Although the cleaning device can in principle be arranged at any position of a spinning station, an air-jet spinning machine, or a service unit, the cleaning device is arranged outside the vortex chamber and preferably outside the area of ​​the air-jet spinneret, so that the air-jet spinning process can be carried out without disruption by the cleaning device. The cleaning device is particularly preferably arranged in a thread take-off direction of the air-jet spun yarn downstream of the yarn-forming element and / or downstream of the take-off channel and / or in the area of ​​a thread preparation unit, in particular on the thread preparation unit.

[0030] An arrangement in the region of a yarn preparation unit is particularly advantageous because the yarn preparation unit, which is otherwise intended to receive the end of a spun yarn, can also receive the free end of the cleaning ribbon in a particularly simple manner and can guide or pull this in the same way as a yarn end into the interior of the air spinneret, in particular into the vortex chamber, in particular up to the outlet of the sliver inlet. Accordingly, it is also preferred that the feeding of the free end of the cleaning ribbon, in particular up to the outlet of the sliver inlet, takes place by means of a fiber guide element. In order to guide the free end of the cleaning ribbon into the vortex chamber orto the exit of the fiber sliver inlet within the vortex chamber, the yarn preparation, in particular a yarn preparation unit, can be switched accordingly, whereby both a direct control of the yarn preparation for gripping the end of the cleaning ribbon is possible, as well as a movement of the storage unit and / or the free end of the cleaning ribbon into the yarn preparation area, so that during regular operation of the yarn preparation the cleaning ribbon is now gripped instead of the yarn.

[0031] Many prior art methods for cleaning a yarn-forming element have the disadvantage that the air-jet spinneret must be opened. Although cleaning a yarn-forming element using a cleaning ribbon with an open spinneret would also be conceivable, a preferred embodiment of the method provides that cleaning always takes place in the closed spinneret or with the vortex chamber closed. Furthermore, it is preferred that cleaning takes place during an interruption of the air-jet spinning operation, so that no spun yarn or fiber sliver to be spun is in the vortex chamber and the cleaning ribbon can be inserted and removed from the vortex chamber unhindered, particularly through the discharge channel.

[0032] A preferred development of the method for cleaning a yarn forming element provides that the drawing-in takes place with a vortex air flow switched on in order to remove deposits and / or to better clean the surface of the extraction channel, since with a vortex air flow switched on, a movement and / or swirling of the cleaning ribbon also occurs during drawing-in.

[0033] Furthermore, the swirling air flow in the swirl chamber is preferably generated with or after the free end of the cleaning ribbon exits the discharge channel, or with or after the free end enters the swirl chamber. This ensures effective and reliable cleaning of the area around the discharge channel opening of the yarn-forming element within the swirl chamber. Furthermore, this allows for reliable guidance of the free end of the cleaning ribbon within the swirl chamber along the surface of the yarn-forming element.

[0034] In principle, the cleaning ribbon can be used repeatedly for any length of time and as often as desired. However, due to increasing contamination and / or wear, particularly in the area of ​​the free end of the cleaning ribbon, it is advantageous to regularly cut off and discard the tip of the free end of the cleaning ribbon, particularly using the thread cutting means specific to the spinning station, air-jet spinning machine, or service unit. This can be done after each cleaning, after a specified number of cleaning cycles, or depending on the degree of contamination or wear. The thread cutting means can particularly preferably be a component of the thread preparation, by means of which a thread end can also preferably be suitably prepared for a piecing process in a known manner after a spinning interruption.Furthermore, regular replacement of the cleaning ribbon after a specified number of cleaning cycles or depending on the degree of soiling or wear is also conceivable. Furthermore, the cleaning ribbon can be cleaned during or after retraction into the cleaning device to at least partially clean the cleaning ribbon and extend its service life.

[0035] In principle, cleaning can take place at any time and can be repeated as often as desired. A preferred embodiment of the method for cleaning a yarn formation element provides for cleaning a yarn formation element during a spinning interruption, for example after at least one or each thread break, after at least one or each yarn cut, during removal of a package wound up using the air-jet spun yarn and / or during a change of a spinning can from which the fiber sliver is fed to the spinning station. Cleaning after a thread break makes it possible, in particular, for contamination as a possible cause of thread break to be removed before the air-jet spinning process is resumed. Cleaning after a yarn cut, during removal of the package orInserting a new empty tube into the winding device and during a spinning can change, like cleaning after a thread break, ensures consistently high yarn quality and strength. Alternatively or additionally, cleaning can also be performed periodically at defined intervals, either the same or different from each other, in particular based on the operating time of the spinning station, the number of thread breaks, the number of yarn cuts, the number of bobbin removals or the number of empty tubes inserted, the number of spinning can changes, and generally the number of spinning interruptions or stops, in order to ensure regular cleaning or to avoid longer periods without cleaning.Alternatively or additionally, cleaning can be performed before the spinning station is put into operation after a defined downtime and / or before the spinning station is shut down in preparation for a defined downtime. This also ensures that these disruptive deposits in the air-jet spinneret are minimized or eliminated as far as possible when the air-jet spinning process is resumed.

[0036] According to a further aspect of the present invention, the spinning station can be comprised of a work station of the air-jet spinning machine. A work station is understood to be any position on the air-jet spinning machine at which an air-spun spun thread or a yarn is produced by means of the spinning station from a fiber sliver fed to the spinning station and is wound onto a package, in particular a cross-wound bobbin, via a winding device downstream of the spinning station in the thread path. The fiber sliver can be fed in via a central fiber sliver storage device assigned to the air-jet spinning machine or via a fiber sliver storage device assigned to the individual spinning station, such as in particular a sliver can, in which a defined amount of fiber sliver is deposited so that it can be removed from the sliver can. The work station can comprise further fiber sliver or thread treatment devices for the defined and needs-based treatment of the fiber sliver or yarn.of the thread. The workstation can thus have sensors for monitoring the sliver feed and / or the sliver parameters and, alternatively, for monitoring the thread take-off, the thread feed to the winding device, the yarn parameters, for cleaning yarn defects and / or for piecing after a sliver or thread break or after a sliver can change or a package removal. Furthermore, the workstation can be assigned sensors or other devices in the area of ​​a drafting system comprising the sliver feed, by means of which the sliver can be defined and drawn as required and / or provided with additional fibers, in particular made of a different fiber material, a so-called core yarn.

[0037] An embodiment of a spinning station according to the invention for an air-jet spinning machine is explained in more detail below with reference to the drawings. The figures show: Fig. 1 a schematic view of an air spinneret of an air spinning machine during the spinning process, Fig. 2 a schematic view of the Figure 1 shown air spinneret with a cleaning device before cleaning a yarn forming element of the air spinneret, and Fig. 3 a schematic view of the in Figure 1 shown air spinneret with a cleaning device during cleaning of the yarn forming element.

[0038] In order to spin a yarn 14 by means of a spinning station 9 of an air spinning machine from a fiber band 11 stretched by means of a drafting device, a Figure 1The fiber sliver 11 is fed into the purely schematically illustrated air-jet spinneret 12 in the region of a feed 10. The fiber sliver 11 passes through an outlet 13 of a fiber sliver inlet 16 into a vortex chamber inside the air-jet spinneret 12 and is spun there into a yarn 14 by means of a vortex air flow on a yarn-forming element 2 formed as a spinning cone. The outer fibers of the fiber sliver 11 are wound around an inner fiber core by means of the vortex air flow generated by the vortex air nozzles, resulting in an air-yarn-specific yarn structure with a parallel yarn core and wrapped fibers arranged at a specific angle. Finally, the spun yarn 14 is drawn off from the air-jet spinneret 12 through a take-off channel 15 in order to be fed to a downstream thread handling device, such as a winding device, for forming a package.

[0039] If a fiber sliver 11 made of synthetic fibers, in particular polyester fibers, is used in air spinning, deposits of fiber fragments and finishing agents may occur on the surface of the yarn forming element 2 or on the surfaces of the walls of the vortex chamber of the air spinning nozzle 12 surrounding the yarn forming element 2 during the air spinning process, which in the long term lead to a deterioration of the spinning result and thus to reduced yarn strength and quality.

[0040] In order to clean this surface, a cleaning device 1 is arranged in the yarn take-off direction behind the take-off channel 15 and in the area of ​​a thread preparation unit of the spinning station 9. Inside a storage unit 4 of the cleaning device 1, a cleaning ribbon 3 is wound onto a storage spool 8.

[0041] The cleaning ribbon 3 is attached to the storage reel 8 by a fixed end 5, allowing it to be repeatedly removed and fixed. The free end 6 of the cleaning ribbon 3 can be removed from and retracted from the storage unit 4 by unwinding and rewinding the storage reel 8. The cleaning ribbon 3 is made of a fiber material and has a rough surface.

[0042] In order to be able to feed the cleaning ribbon 3 to the air spinneret 12 after it has been rolled out of the storage unit 4, the cleaning device 1 finally has a cleaning ribbon guide 7, which is formed by further components of the spinning station 9, in particular a thread preparation unit.

[0043] In order to be able to clean the surface of the yarn forming element 2, the air spinning process is interrupted and then, with the air spinning nozzle 12 still closed, the free end 6 of the cleaning ribbon 3 is guided by means of the cleaning ribbon guide 7 into the area of ​​the outer opening of the discharge channel 15 (see Figure 2 ).

[0044] Subsequently, the free end 6 of the cleaning ribbon 3 is guided into the take-off channel 15 by means of the thread preparation and from there advanced into the interior of the vortex chamber in the direction of the outlet 13 of the fiber sliver inlet 16. By activating the vortex air flow inside the vortex chamber, the free end 6 of the cleaning ribbon 3 is moved repeatedly against and around the surface of the yarn-forming element 2, which is formed as a spinning cone. By further feeding the cleaning ribbon 3 to the vortex chamber, the free end 6 of the cleaning ribbon 3 can also be guided past the nozzle openings of the vortex air nozzles, with particular cleaning taking place in the area of ​​the tip of the yarn-forming element 2 and in the area of ​​the nozzle openings.The movement of the free end 6 caused by the swirling air flow continues along the cleaning ribbon 3 in the direction of the fixed end 5 in such a way that the surface of the discharge channel 15 within the yarn-forming element 2 is also cleaned. The fixed end 5 of the cleaning ribbon 3 is rotatably mounted about the extension axis of the cleaning ribbon 3 in such a way that an undesirably strong twisting of the cleaning ribbon 3 can be avoided by propagating the movement of the free end 6 in the direction of the fixed end 5.

[0045] Finally, the cleaning ribbon 3 is withdrawn again from the interior of the air spinneret 12 via the withdrawal channel 15, whereby the surface of the withdrawal channel 15 is repeatedly cleaned. In order to be able to store the cleaning ribbon 3 without knots and loops, the cleaning ribbon 3 is again wound onto the storage spool 8 inside the storage unit 4. List of reference symbols

[0046] 1Cleaning device 2Yarn forming element 3Cleaning ribbon 4Storage unit 5Fixed end 6Free end 7Cleaning ribbon guide 8Storage bobbin 9Spinning station 10Feeder 11Sliver 12Air spinneret 13Outlet 14Yarn 15Take-off channel 16Sliver inlet

Claims

1. Spinning station (9) of an air-jet spinning machine, comprising - a feed (10) for a sliver (11) to an air spinneret (12), - an air spinneret (12) having a sliver inlet (16) for the introduction of the supplied sliver (11) into the air spinneret (12), - a vortex chamber arranged inside the air spinneret (12) for generating a vortex airflow by means of at least one vortex air nozzle that opens into the vortex chamber, - a yarn-forming element (2) arranged within the vortex chamber for producing a yarn (14) from the sliver (11) fed into the vortex chamber via an outlet (13) of the sliver inlet (16), and - a draw-off channel (15) extending through the yarn-forming element (2) for drawing off the air-spun yarn (14), characterized in that the spinning station (9) has a cleaning device (1), the cleaning device (1) comprising - a cleaning ribbon (3), - a cleaning ribbon guide (7) for feeding a free end (6) of the cleaning ribbon (3) to the yarn-forming element (2) in order to mechanically clean a surface of the yarn-forming element (2), and - a storage unit (4) for providing and retracting the cleaning ribbon (3), - a fixed end (5) of the cleaning ribbon (3) being fixed to the storage unit (4) and a free end (6) of the cleaning ribbon (3) being able to be provided for cleaning the yarn-forming element (2) and being retractable again after cleaning, - the storage unit (4) being designed to store, outside the cleaning process, the cleaning ribbon (3) in the retracted state during operation of a spinning station (9) which has the air spinneret (12), the cleaning device (1) being arranged outside the vortex chamber in such a way that an air-jet spinning process can be carried out undisturbed by the cleaning device (1).

2. Spinning station (9) of an air-jet spinning machine according to claim 1, characterized in that the cleaning device (1) is arranged outside the air spinneret (12).

3. Spinning station (9) of an air-jet spinning machine according to claim 1 or 2, characterized in that the cleaning device (1) is arranged downstream of the yarn-forming element (2) in the thread draw-off direction of the air-spun yarn (14) and / or in the region of a thread preparation unit.

4. Spinning station (9) of an air-jet spinning machine according to any of the preceding claims, characterized in that the storage unit (4) has a storage reel (8) for unwinding and winding the cleaning ribbon (3), the fixed end (5) of the cleaning ribbon (3) being fixed to the storage reel (8).

5. Spinning station (9) of an air-jet spinning machine according to any of the preceding claims, characterized in that the storage unit (4) is connected to an electric and / or pneumatic drive unit for the controlled provision and retraction of the free end (6) of the cleaning ribbon (3).

6. Method for cleaning a yarn-forming element (2) of an air spinneret (12), characterized by the steps of: - feeding a free end (6) of a cleaning ribbon (3) from a cleaning device (1) through a draw-off channel (15) of a yarn-forming element (2) into a vortex chamber of the air spinneret (12), - generating a vortex airflow in the vortex chamber by means of at least one vortex air nozzle that opens into the vortex chamber, in order to guide the cleaning ribbon (3) over a surface of the yarn-forming element (2) and / or over at least one nozzle opening of the vortex air nozzle, and subsequently - retracting the cleaning ribbon (3) through the draw-off channel (15) to the cleaning device (1).

7. Method for cleaning a yarn-forming element (2) according to claim 6, characterized in that the vortex airflow in the vortex chamber is generated as or after the free end (6) of the cleaning ribbon (3) emerges from the draw-off channel (15) or as or after the free end (6) enters the vortex chamber.

8. Method for cleaning a yarn-forming element (2) according to claim 6 or 7, characterized in that the feeding of the free end (6) of the cleaning ribbon (3) is operated via a thread preparation unit.

9. Method for cleaning a yarn-forming element (2) according to at least one of claims 6 to 8, characterized in that the cleaning takes place when the air-jet spinning operation is interrupted with the air spinneret (12) closed.

10. Method for cleaning a yarn-forming element (2) according to at least one of claims 6 to 9, characterized in that the retraction of the free end (6) takes place with the vortex airflow switched on.

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