Air spinning device and method for treating the surface inside an air spinning device

Abstract

The invention relates to an air spinning device and a method for surface treatment within an air spinning device, comprising a yarn take-off channel traversing a spinning cone and having an outlet for discharged a yarn from the air spinning device, a spinning housing arranged at a distance from the spinning cone and enclosing the spinning cone, and a nozzle device pressurised with compressed air for generating an airflow circulating around the spinning cone in a gap between the spinning cone and the spinning housing. To provide a method for surface treatment within an air spinning device and an air spinning device that enables simple and rapid surface treatment within the air spinning device, a fluid introduction device is provided on the air spinning device. This device is designed to supply a fluid to the outlet side of the yarn take-off channel or to introduce a fluid into the outlet of the yarn take-off channel.

Description

[0001] The invention relates to an air spinning device and a method for surface treatment within an air spinning device with a spinning cone having a thread take-off channel, the thread take-off channel having an outlet for discharging a spinning thread from the air spinning device, a spinning housing arranged at a distance from the spinning cone and enclosing the spinning cone, and a nozzle device which can be pressurised with compressed air for generating an air flow circulating the spinning cone in an enveloping gap between the spinning cone and the spinning housing.

[0002] In the textile industry, various processes and spinning devices are known for the production of textile threads. Ring spinning machines and / or open-end rotor spinning machines, for example, have long been widely used and extremely proven. Furthermore, especially in connection with the processing of synthetic yarn material, air-jet spinning devices are also known. In these devices, a thread is formed from a previously drawn fiber sliver via the air flow circulating the hollow spinning cone. Within the air-jet spinning device, the outer fibers of the fiber sliver are placed around the spinning cone in a known manner with the help of the rotational flow generated by one or more air nozzles in the enveloping gap between the spinning cone and the spinning housing and are wound helically around the core fibers of the fiber sliver.This produces an air-spun thread with suitable strength properties, which is transported via an outlet of the thread take-off channel formed by the hollow space of the spinning cone to a winding device on which the air-spun thread is wound.

[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, particularly when spinning polymer fibers, especially polyester (PES) fibers, deposits of polymer residues, polyester fiber fragments, and finishing agents often occur on the surfaces of the air-jet spinning device. However, such deposits can significantly disrupt the air-jet spinning process and significantly reduce the spinning result and thus the thread quality. In particular, thread breakage can occur during the air-jet spinning process due to the resulting increased friction between the surfaces of the air-jet spinning device and the fibers.In addition, the air jets and other components of the air spinning device can become clogged with deposits, resulting in lower strength and quality of the resulting thread. Such deposits also adversely limit the possible spinning range.

[0004] To avoid such errors, it is necessary to clean the air spinning device at regular intervals, which requires not only an interruption of the spinning process but also an opening of the air spinning device, which leads to long downtimes of the air spinning device and associated production interruptions.

[0005] EP2955255A2 discloses a method for cleaning a spinneret of an air-jet spinning device. An additive is used.

[0006] Based on this, the object of the invention is to provide a method for surface treatment, in particular for cleaning and / or supplying an additive, of an air spinning device and an air spinning device which enables simple and rapid surface treatment, in particular cleaning and / or additive supply, of the air spinning device.

[0007] The invention solves this problem by a method for surface treatment, in particular for cleaning and / or for adding an additive, an air spinning device having the features of claim 1, and by an air spinning device having the features of claim 9. Advantageous developments of the method according to the invention are specified in dependent claims 2 to 8. Further embodiments of the air spinning device according to the invention are mentioned in dependent claims 10 to 12.

[0008] The method according to the invention is suitable for an air spinning device which a thread take-off channel passing through a spinning cone with an outlet for discharging a spinning thread from the air spinning device, a spinning housing, arranged in particular coaxially and at a distance from the spinning cone, enclosing the spinning cone, and a nozzle device which can be pressurised with compressed air for generating an air flow circulating the spinning cone in an enveloping gap between the spinning cone and the spinning housing has.

[0009] For the purposes of the present invention, a yarn withdrawal channel is understood to be a channel through which the air-spun yarn can be withdrawn or discharged from the spinning device. The yarn withdrawal channel can preferably be formed in one or more parts and, more preferably, coaxial with the spinning cone, thereby providing a greater degree of freedom in the design of the spinning cone and the air-spinning device.

[0010] According to a preferred embodiment, the spinning cone can also be designed in one or more parts and, more preferably, at least partially or completely enclose the thread withdrawal channel. For example, the spinning cone can extend along the thread withdrawal channel, and thus along the thread running and thread withdrawal direction, such that the inlet opening of the spinning cone for receiving the thread simultaneously forms the inlet opening of the thread withdrawal channel. The outlet opening of the spinning cone for discharging the thread from the spinning cone can, more preferably, form the outlet of the thread withdrawal channel.In an alternative preferred embodiment, the outlet opening of the spinning cone adjoins a through-opening of the yarn withdrawal channel, wherein the yarn withdrawal channel is configured in at least two parts: a first yarn withdrawal channel section traversing the spinning cone and a second yarn withdrawal channel section adjoining the spinning cone in the yarn travel direction. The second yarn withdrawal channel section can furthermore preferably be formed by the spinning housing.

[0011] According to a further preferred embodiment, the thread withdrawal channel can be designed linearly along the thread travel direction, in particular axially rectilinearly, without deflection sections or alternatively with at least one deflection section deflecting the thread to be withdrawn from the thread travel direction. The thread travel direction corresponds to a straight connecting line running between the inlet opening and the outlet. The deflection section can be a bend in the thread withdrawal channel or a projection projecting into the thread withdrawal channel. By means of one or more deflection sections arranged along the thread travel direction, the thread can be deflected to influence its properties. For example, the design of a deflection section can influence the hairiness of the thread as required.If several deflection sections are to be provided, for example to form a spiral thread withdrawal channel section, the thread to be withdrawn can be subjected to a twist.

[0012] According to the present invention, the spinning housing encloses the spinning cone. This is understood to mean a configuration of the spinning housing that surrounds the spinning cone at least radially along the thread running direction. In a conventional configuration, the spinning housing has an inlet spaced from the spinning cone for receiving and feeding a fiber strand to the spinning cone. The spinning housing is preferably arranged coaxially to the spinning cone. The spinning housing preferably has a passage that forms the outlet, in which the outlet is arranged or through which a segment encompassing the outlet, for example of the spinning cone or the thread take-off channel, extends.

[0013] According to a preferred embodiment, the spin housing can be constructed in one part or, in a conventional design, in multiple parts. The multi-part design advantageously allows the air-jet spinning device to be opened to ensure easy access to the spin cone. For example, the multi-part spin housing can comprise two spin housing segments that are movable relative to one another, with one spin housing segment comprising an inlet for receiving and feeding a fiber strand to the spin cone, and the other spin housing segment supporting the spin cone.

[0014] In principle, according to a preferred embodiment, the spinning housing can have the inlet, an internal vortex chamber surrounding the enveloping gap, and preferably a plurality of vortex air nozzles opening into the vortex chamber, 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 or the enveloping gap via the vortex air nozzles. The vortex air nozzle(s) is(are) arranged in a known manner to generate a vortex air flow within the vortex chamber for air spinning the fiber strand into a thread. The vortex chamber is arranged downstream of the inlet along a transport direction of the fiber strand, which corresponds to a thread running direction.

[0015] Characteristic of the method according to the invention is that during a spinning process or during an interruption of the spinning process a fluid is supplied to the outlet on the outlet side or introduced into the outlet and an air flow circulating the spinning cone in the enveloping gap is generated by means of the nozzle device becomes.

[0016] According to the method according to the invention, at defined or definable times during the spinning process or during a planned or unscheduled interruption of the spinning process, for example as a result of a thread breakage or cut, maintenance, a bobbin change, a current / voltage drop, a detected deviation in the yarn quality, after a predetermined spinning or operating time, or the like, a fluid is presented on the output side of the outlet of the thread take-off channel or is introduced into the outlet of the thread take-off channel. A presentation in the sense of the present invention is understood to mean a fluid supply to the area in front of the outlet outside the thread take-off channel such that the supplied fluid can be sucked in via the negative pressure present in the thread take-off channel. The thread take-off channel extends, as described above by way of example, - viewed in the direction of thread travel - from the inlet or outlet.from the inlet opening of the spinning cone to the outlet of the air-jet spinning device, which is formed, for example, by the open end of the hollow spinning cone. The nozzle device, which is activated before, during, or after the start of the fluid introduction and preferably comprises the swirling air nozzles, generates a spinning pressure through the air flow circulating the spinning cone in the enveloping gap. This creates a negative pressure at the inlet of the spinning cone and consequently in the thread withdrawal channel. This negative pressure ensures that the fluid presented to the outlet on the outlet side or introduced into the outlet can be reliably guided out of the spinning cone on the inlet side of the air-jet spinning device.The spinning pressure then causes the fluid to be guided through the envelope gap at least over the circumferential surface of the spinning cone, so that a reliable application of both the inner surface of the thread take-off channel and the surface areas of the air spinning device forming the spinning cone and more preferably surrounding it is achieved.

[0017] The preferred method thus makes it possible to reliably supply the air spinning device with a fluid even in the closed, operational state in order to treat the surfaces of the air spinning device in a defined manner.

[0018] According to a preferred embodiment, the surface treatment can be cleaning, and according to a further embodiment, additive addition, by means of the former the surfaces of the air-jet spinning device can be treated or treated as needed, particularly during a spinning interruption, and by means of the latter the fibers of the thread and the surfaces of the air-jet spinning device can be treated or treated as needed, particularly during a spinning process. When deposited on the fibers of the thread, an additive addition has a beneficial effect, particularly on subsequent processing of the thread. Furthermore, the additive addition can be used to provide the surfaces of the air-jet spinning device with a layer or film, which can reduce deposits on the surface and consequently possible blockages as well as friction between the surfaces and the fibers.

[0019] The supply of a fluid for cleaning purposes and / or as an additive makes it possible to dispense with the time-consuming opening or dismantling of the air-jet spinning device, which leads to significantly shorter downtimes, particularly compared to the cleaning methods known from the prior art, which provide for opening or dismantling of the air-jet spinning device for cleaning it. Furthermore, the fluid can be supplied in an alternative, in particular space-saving, manner. This is because there is no longer any need for a conventional fluid supply in the region of a fiber strand introduction section or in an area of the open air-jet spinning device. For example, the distance between the output roller pair of the air-jet spinning device in the thread running direction orThe distance between the fluid supply processes in the upstream drafting device in the fiber strand feed direction can be kept to a minimum in order to ensure an almost seamless feed of the fiber strand from the drafting device to the air-jet spinning device. Furthermore, it is possible to dispense with the need for supplying an additive into the open area of the air-jet spinning device. The intervals between the fluid supply processes are preferably freely selectable, whereby, in particular due to short surface treatment times, such as short cleaning or additive supply times, more frequent surface treatments, such as preferably cleaning or additive supply, in an exclusive or combined manner, are possible compared to the known methods with corresponding downtimes, whereby a high level of production reliability can be ensured.

[0020] The selection of the fluid as well as the type of presentation of the fluid on the output side to the outlet and the introduction into the outlet can basically be carried out in any way, for example in such a way that the fluid is presented as a liquid stream on the output side to the outlet or introduced into the outlet. According to a preferred embodiment of the invention, the fluid is atomized before presentation or introduction. Atomization is understood to mean the division of the liquid into fine droplets as an aerosol in a gas, e.g. air. Presenting or introducing the fluid as an aerosol makes it possible to minimize the amount of fluid required for surface treatment, while at the same time ensuring good distribution of the fluid on the surfaces of the air spinning device to be treated.The preferred use of the atomized fluid, i.e. the aerosol, also enables particularly rapid drying of the surfaces of the air spinning device, which can additionally reduce downtimes of the air spinning device.

[0021] The configuration of the fluid supply on the output side to the outlet or the introduction of the fluid into the outlet of the thread withdrawal channel is also fundamentally freely selectable. According to a preferred embodiment of the invention, the fluid is introduced into the thread withdrawal channel via a feed line connectable to the outlet of the thread withdrawal channel.

[0022] According to this preferred embodiment of the invention, a feed line carrying the fluid is connected to the outlet of the thread take-off channel to introduce the fluid into the thread take-off channel, whereby the fluid is subsequently introduced directly into the thread take-off channel as a liquid stream or in atomized form as an aerosol. This preferred embodiment of the invention ensures, in a particularly reliable manner, complete feeding of the fluid into the thread take-off channel, so that at the same time it can be prevented that the fluid reaches areas in the vicinity of the air spinning device that are not intended for this purpose. The feed line is preferably adapted to the design of the outlet of the thread take-off channel in order to ensure leak-free introduction of the fluid into the thread take-off channel.

[0023] According to a further preferred embodiment of the invention, the fluid is fed to the yarn take-off channel via a feed line ending adjacent to the outlet of the yarn take-off channel. According to this preferred embodiment of the invention, the fluid is presented to the outlet of the yarn take-off channel outside the air-jet spinning device, adjacent to the outlet of the yarn take-off channel, in the yarn travel direction. This can be achieved, for example, by a feed line whose end is arranged in such a fixed position relative to the outlet of the yarn take-off channel that it is arranged outside the yarn path during the spinning process and thus has no influence on the operation of the air-jet spinning device during the spinning process. The feed line is aligned such that the escaping fluid is presented or fed to the outlet of the yarn take-off channel.There is therefore no need to connect the feed line to the outlet of the air spinning device, particularly after an interruption of a spinning process, which can further reduce downtimes.

[0024] According to a further preferred embodiment of the invention, the fluid is discharged via an expansion chamber adjacent to the enveloping gap along the thread travel direction and a discharge channel of the air-jet spinning device connected to the expansion chamber. Due to the spinning pressure generated by the nozzle device, the fluid passes from the inlet of the thread take-off channel into the enveloping gap between the spinning cone and the spinning housing and subsequently into an expansion chamber adjacent to the enveloping gap. The fluid can then be reliably discharged from the air-jet spinning device via a discharge channel fluidically connected to the expansion chamber, together with, in particular, the deposits and contaminants removed by the fluid. The fluid can subsequently be collected in a controlled manner and, if necessary, subjected to further processing, e.g., filtering and reuse.

[0025] According to a further preferred embodiment of the invention, it is provided that the fluid is introduced in the region of a thread preparation unit which adjoins the outlet of the thread take-off channel of the air spinning device in the thread take-off direction.

[0026] If the spinning process is interrupted, for example due to a break in the fed fiber structure or because the spun thread was separated by a controlled cut in a thread clearer, the subsequent piecing process used to remedy the spinning interruption involves first retrieving the thread end of the already spun thread, which is usually wound up on an associated winding package, and transporting it through the air spinning device to at least the entrance to the spinning cone or into the area of the drafting system. For this purpose, it is already known to use a thread preparation unit which, for example, has a thread deflection unit and a thread guide channel arranged thereon, wherein the thread end drawn from the winding package, for examplea cross-wound bobbin, the thread taken up is freed from its thread twist and loose fibers and is fed via the outlet of the thread guide channel of the air spinning device to the spinning cone against the direction of thread travel for piecing.

[0027] According to the preferred development of the invention, it is provided that the fluid is introduced during an interruption of the spinning process, i.e. at the beginning of the interruption or after the beginning, within the thread preparation unit, for example into the thread guide channel, from where it then reaches the air spinning device via the outlet of the thread take-off channel due to the spinning pressure.This preferred embodiment of the invention ensures a particularly uniform and reliable introduction of the fluid into the air spinning device, wherein, in addition, the thread preparation unit optionally arranged downstream of the air spinning device is also cleaned of impurities, so that deposits in the area of the thread path between the air spinning device and the winding package are removed of impurities in a particularly reliable manner and, optionally, the surfaces of the thread preparation unit can additionally be provided with a layer or film as described above by way of example.

[0028] According to a preferred embodiment of the invention, the dynamic pressure is generated by activating the nozzle device, which generates an air flow in the enveloping gap, before or beginning with the introduction of the fluid. This preferred embodiment of the invention ensures that sufficient dynamic pressure is already present at the time the fluid is introduced, allowing the fluid to reliably enter the air-jet spinning device via the inlet of the spinning cone, where it can be used to treat the surfaces of the air-jet spinning device.

[0029] According to a further preferred embodiment of the invention, the air flow in the enveloping gap is maintained at least temporarily, i.e., for a defined or definable period of time, beyond the termination of the fluid introduction. This preferred embodiment of the invention ensures that, after the fluid introduction has already been terminated, the treated surfaces are dried via the air flow still present, thereby particularly effectively preventing liquid residues such as drops or the like, which could potentially impair the spinning process.

[0030] The invention further achieves the object by an air-jet spinning device with a spinning cone having a thread take-off channel, wherein the thread take-off channel has an outlet for discharging a spun thread from the air-jet spinning device, a spinning housing arranged, in particular coaxially, at a distance from the spinning cone and enclosing the spinning cone, and a nozzle device pressurized with compressed air for generating an air flow circulating the spinning cone in an enveloping gap between the spinning cone and the spinning housing. According to the invention, the air-jet spinning device has a fluid introduction device designed to supply a fluid on the outlet side to the outlet of the thread take-off channel or to introduce a fluid into the outlet of the thread take-off channel.

[0031] The air spinning device may have a design according to one of the embodiments described above.

[0032] The air-jet spinning device is characterized by the fluid introduction device, which is used - in particular at least during a spinning process or an interruption of the spinning process - to present a fluid to the outlet or to introduce it into the outlet of the thread take-off channel, whereby a surface treatment can take place within the air-jet spinning device without prior dismantling or opening of the air-jet spinning device. The fluid introduction device is preferably designed such that the fluid, e.g. conveyed from a suitable reservoir, can be presented to the outlet of the thread take-off channel via it, where it then passes into the air-jet spinning device via the outlet of the thread take-off channel due to a spinning pressure following activation of the nozzle device and effects a treatment of the surfaces of the air-jet spinning device. Alternatively, the air-jet spinning device is preferably designed toconveyed from a suitable reservoir, into the outlet of the thread withdrawal channel.

[0033] The air-jet spinning device thus enables the removal of deposits and contaminants within the air-jet spinning device in a particularly simple and convenient manner without the need to open or disassemble the device, thereby achieving particularly short downtimes for cleaning. Alternatively, the surfaces can be coated with a layer or film as described above.

[0034] The air spinning device is preferably designed to carry out a method according to one of the preferred embodiments described above.

[0035] The design of the fluid introduction device for supplying or introducing the fluid is fundamentally freely selectable. According to a preferred embodiment of the invention, the fluid introduction device has a feed line that can be connected, in particular in a liquid-tight manner, to the outlet of the thread withdrawal channel and / or arranged adjacent to the outlet of the thread withdrawal channel. According to this preferred embodiment of the invention, the fluid introduction device has a feed line that is connected, for example, to a fluid reservoir and via whose outlet the fluid is supplied to the outlet of the thread withdrawal channel. For this purpose, the feed line can preferably be designed to be connected directly to the thread withdrawal channel or is arranged in a stationary manner adjacent to the outlet of the thread withdrawal channel in such a way that the fluid emerging from the feed line reliably reaches the outlet of the thread withdrawal channel.

[0036] According to a further preferred embodiment of the invention, the fluid introduction device is designed to atomize the fluid. According to this preferred embodiment of the invention, the fluid can be introduced as an aerosol into the outlet of the thread withdrawal channel by means of the fluid introduction device, thereby achieving a particularly good distribution of the fluid within the air spinning device while reducing the amount of fluid required for surface treatment.

[0037] According to a further preferred embodiment of the invention, the feed line is connected to a yarn preparation unit arranged downstream of the outlet of the yarn take-off channel in the yarn travel direction. According to this preferred embodiment of the invention, the fluid is fed into the air-jet spinning device by introducing the fluid into a yarn preparation unit arranged downstream of the yarn take-off channel. This unit serves, after an interruption of the spinning process, e.g., due to a break in the fed fiber strand or because the spun yarn was separated by a controlled cut of a yarn cleaner, to retrieve the yarn end, which has usually run onto an associated winding package, and to feed it to the air-jet spinning device, where a piecing process and a subsequent spinning process then take place within the air-jet spinning device.

[0038] Depending on the intended use, the fluid is either a cleaning fluid with a cleaning effect on the surfaces within the air-jet spinning device or an additive with an effect that directly or indirectly influences the fiber or thread properties as needed through contact with the surfaces within the air-jet spinning device. The composition of such cleaning fluids, which may in particular comprise water or an air-water mixture or another composition, as well as additives, e.g., previously known from EP 2 730 695 A1, are well known from the prior art and are not the subject of the present invention, which is why a detailed description of a corresponding composition is omitted.

[0039] Embodiments of the invention are explained below with reference to the drawings. In the drawings: Fig. 1 is a schematic representation of a first embodiment of an air-jet spinning device with an upstream drafting system; Fig. 2 is a schematic representation of a second embodiment of an air-jet spinning device with an upstream drafting system; and Fig. 3 is a schematic representation of a thread preparation unit arranged downstream of an air-jet spinning device in the direction of thread travel.

[0040] In Figure 1For a general understanding of the functioning of an air-jet spinning device 2, the basic structure of a drafting system 1 with a downstream air-jet spinning device 2 is shown. A fiber strand drawn off from a fiber strand source (not shown here) is drawn in by an input roller pair formed by an input top roller 26 and an input bottom roller 27. The fiber strand is then drawn in a defined manner between the second drafting system top roller 28 and the second drafting system bottom roller 29 as well as the third drafting system top roller 24 and the third drafting system bottom roller 25 and the subsequent output roller pair consisting of the output top roller 22 and the output bottom roller 23.The drawn fiber strand then enters the air-jet spinning device 2 via an inlet region 12 of a fiber strand introduction unit and downstream nozzle device 6, where it is formed into a thread using a spinning cone 5 and the nozzle device 6 of the air-jet spinning device 2. The air-jet spinning device 2 has a multi-part spinning housing 13 with a first spinning housing segment comprising the inlet region 12 and the nozzle device 6, and a second spinning housing segment supporting the spinning cone 5. The first and second spinning housing segments are designed to move relative to one another along the thread travel direction to open the air-jet spinning device 2, whereby the spinning cone 5 is exposed in the open state of the air-jet spinning device 2 or the spinning housing 13 and is accessible from outside the spinning housing 13.

[0041] The nozzle device 6 has nozzles 7, 8, which are connected to a compressed air source 10 via lines 9. The air flowing out of the nozzles 7, 8 generates a swirling air flow, which is applied to the drawn fiber strand. The air flow flows around the spinning cone 5 in an enveloping gap 15 between the spinning cone 5 and the spinning housing 13, which is arranged coaxially to the spinning cone 5 and encloses the spinning cone 5, and thus applies pressure to the drawn fiber strand. In the air-jet spinning device 2, the outer wrapping fibers of the fiber strand are wound around the inner core fibers of the fiber strand due to the swirling air flow prevailing in the enveloping gap 15 within the air-jet spinning device 2, thereby ensuring the desired strength of the thread.The thread thus formed is then drawn off from the air spinning device 2 via an outlet 17 of the thread take-off channel 3, which extends in the thread running direction R from an inlet 4 of the spinning cone 5 to its outlet 17.

[0042] For the treatment of surfaces within the air spinning device 2 in the closed state, the Figure 1The air-spinning device 2 shown has a fluid introduction device 11a, by means of which, for example, during a spinning process or in the event of a spinning interruption, a fluid, for example a cleaning liquid or an additive, is presented as an aerosol via a feed line 14 and a nozzle 16 to the outlet 17 of the thread guide channel 3. To introduce the fluid into the air-spinning device 2, the nozzle device 6 is activated before or during the application of the fluid at the outlet 17, whereby a spinning pressure is applied within the air-spinning device 2. As a result of this, a negative pressure is applied at the inlet 4 of the spinning cone 5 due to the air flow circulating in the envelope gap 15 between the spinning cone 5 and the spinning housing 13, so that the fluid is guided via the outlet 17 through the thread guide channel 3 to the inlet of the spinning cone 5 and from there into an expansion chamber 19. With this flow, the fluid effects a treatment orExposure to the surfaces within the air spinning device 2, whereby the fluid reaches the expansion chamber 19 due to the spinning pressure, from where it can be discharged via the discharge channel 20 with, for example, impurities detached from the surfaces.

[0043] Activation of the nozzle device 6 beyond the end of the introduction of the fluid causes drying of the surfaces treated with the fluid within the air spinning device 2.

[0044] In Figure 2 a further embodiment of an air spinning device 2 is shown, which differs from the one shown in Figure 1differs from the air spinning device 2 shown in that the fluid introduction device 11b has a, in particular flexible, feed line 14, at the free end of which a connecting element 18 is arranged, by means of which the feed line 14 can be connected directly in a liquid-tight manner to the outlet 17 of the thread take-off channel 3. A fluid, for example a cleaning liquid or an additive, can then be introduced directly into the thread take-off channel 3 via the connecting element 18. For the liquid-tight arrangement, the connecting element 18 according to this preferred embodiment has a conical shape, which comes into operative connection with a conical receptacle formed in or on the outlet 17, for example in the form of a sealing lip.

[0045] Figure 3shows, in a schematic representation, a thread deflection unit 30 which is optionally arranged downstream of the air-jet spinning device 2 and which is connected to a thread preparation unit 31 via a thread guide channel 32 connected to its output 33. The air-jet spinning device 2, the thread deflection unit 30 and the thread preparation unit 31 with its thread guide channel 32 are components of a spinning station (not shown here) of an air-jet spinning machine, in which, during the spinning process, a thread emerging from the air-jet spinning device 2 is wound onto a take-up package (not shown here).

[0046] During the normal spinning process, the yarn produced in the air-jet spinning device 2 is drawn off and guided via the yarn deflection unit 30, the yarn guide channel 32, and the yarn preparation unit 31 to a take-up bobbin, onto which the yarn is wound. If spinning is interrupted, e.g., due to a yarn breakage or a controlled cut of an already spun yarn, a piecing process must first be performed before the spinning process can be restarted. To perform a piecing process, the end of the already finished yarn, usually located on the take-up bobbin, must be repositioned within the fiber strand area of the air-jet spinning device 2.

[0047] For this purpose, the thread end of the already produced thread is usually retrieved from the take-up package via a thread transfer device (not shown here) and transferred to the thread preparation unit 31, which is equipped with a holding and release tube 34 and arranged downstream of the air spinning device 2 in the thread travel direction R, in order to free the thread end as far as possible of any twists and loose fibers while clamping the thread in the holding and release tube 34. For this purpose, an injection nozzle (not shown) is arranged upstream of the holding and release tube 34 in the thread travel direction R, via which injection nozzle compressed air can be supplied to the thread guide channel 32 and a vortex air flow directed counter to the thread travel direction R can be generated in the region of the holding and release tube 34 to open the thread end.The dissolved and prepared thread is reliably fed to the outlet 17 of the air spinning device 2 via a through-channel 35 when compressed air is applied in the thread guide channel 32.

[0048] To introduce a fluid into the outlet 17 of the air-jet spinning device 2, the thread guide channel 32 of the thread preparation unit 31 is connected to a fluid introduction device 11c, by means of which the fluid, for example a cleaning liquid or an additive, can be introduced into the thread guide channel 32 of the thread preparation unit 31 via a feed line 14 and a nozzle 16 in, for example, atomized form. After an interruption of the spinning process, with compressed air applied in the thread guide channel 32 and with spinning pressure applied in the air-jet spinning device 2, the compressed air flow prevailing in the thread guide channel 32 entrains the fluid, and the negative pressure present in the thread take-off channel 3 introduces the fluid into the outlet 17 of the thread take-off channel 3, where it treats the internal surfaces of the air-jet spinning device 2 in the manner described above. List of reference symbols 1 drafting system 19 Expansion space 2 Air spinning device 20 drainage channel 3 Thread take-off channel 22 Output top roller 4 Spinning cone entrance 23 Output bottom roller 5 spinning cone 24 third drafting system top roller 6 Nozzle device 25 third drafting system bottom roller 7 nozzle 26 Input top roller 8 nozzle 27 Input bottom roller 9 Line 28 second drafting system top roller 10 Compressed air source 29 second drafting system bottom roller 11a, 11b, 11c Fluid introduction device 30 Thread deflection unit 31 Thread preparation unit 12 Entrance area 32 Thread guide channel 13 Spinning housing 33 Exit 14 feed line 34 Holding and release tubes 15 Envelope gap 35 Through channel 16 nozzle 17 Exit R Thread direction 18 connecting element

Claims

1. Method for surface treatment within an air-jet spinning device (2), which comprises - a yarn take-off channel (3) traversing a spinning cone (5) and having an outlet (17) for withdrawing a spinning yarn from the air-jet spinning device (2), - a spinning housing (13) arranged at a distance from the spinning cone (5) and enclosing the spinning cone (5), and - a nozzle device (6) which can be supplied with compressed air for generating an air flow circulating the spinning cone (5) in an envelope gap (15) between the spinning cone (5) and the spinning housing (13), characterised in that, during a spinning process or an interruption of the spinning process, - a fluid is supplied to the outlet (17) on the outlet side or introduced into the outlet (17), the fluid being a cleaning fluid with an effect of cleaning the surfaces inside the air-jet spinning device (2) or being an additive with an effect of influencing the fibre or the fibre or yarn property, directly or indirectly via an effect that influences the surfaces inside the air-jet spinning device (2) as needed, and - temporally before, during or after the presentation or introduction of the fluid by means of the nozzle device (6), an air flow is generated that circulates around the spinning cone (5) in the envelope gap (15), whereby the fluid supplied to or introduced into the outlet (17) passes via the outlet (17) of the yarn take-off channel (3) into the air-jet spinning device (2) in order to effect a treatment of the surface of the air-jet spinning device (2).

2. The method according to claim 1, characterised in that the fluid is atomised before being fed in front of or into the yarn take-off channel (3).

3. Method according to claim 1 or 2, characterised in that the fluid is introduced into the yarn take-off channel (3) via a feed line (14) which can be connected to an outlet (17) of the yarn take-off channel (3).

4. Method according to one or more of the preceding claims, characterised in that the fluid is supplied to the yarn take-off channel (3) via a feed line (14) ending adjacent to the outlet (17) of the yarn take-off channel (3).

5. Method according to one or more of the preceding claims, characterized in that the fluid is discharged via an expansion space (19) adjacent to the enveloping gap (15) and a drainage channel (20) connected to the expansion space (19).

6. Method according to one or more of the preceding claims, characterised in that the fluid is introduced in the region of a yarn preparation unit (21) arranged downstream of the outlet (17) of the yarn take-off channel (3) in the yarn take-off direction (R).

7. Method according to one or more of the preceding claims, characterized in that before or starting with the introduction of the fluid, the air flow is generated in the enveloping gap (15).

8. Method according to one or more of the preceding claims, characterized in that beyond the termination of the introduction of the fluid, the air flow in the enveloping gap (15) is maintained at least temporarily.

9. Air-jet spinning device (2) with - a yarn take-off channel (3) traversing a spinning cone (5) and having an outlet (17) for withdrawing a spinning yarn from the air-jet spinning device (2), - a spinning housing (13) arranged at a distance from the spinning cone (5) and enclosing the spinning cone (5) and - a nozzle device (6) which can be supplied with compressed air for generating an air flow circulating the spinning cone (5) in an envelope gap (15) between the spinning cone (5) and the spinning housing (13), characterised by a fluid introduction device (11a, 11b, 11c) adapted to feed a fluid downstream to the outlet (17) or to introduce a fluid into the outlet (17), where wherein the fluid is a cleaning fluid having a surface-cleaning effect within the air-jet spinning device (2) or an additive having a fibre-modifying effect directly or indirectly via contact with the surfaces within the air-jet spinning device (2), wherein the air-jet spinning device (2) is configured to generate a spinning pressure in response to activation of the nozzle device (6), whereby the fluid supplied to the outlet (17) or introduced into the outlet (17) passes via the outlet (17) of the yarn take-off channel (3) into the air-jet spinning device (2) in order to effect a treatment of the surface of the air-jet spinning device (2).

10. Air-jet spinning device (2) according to claim 9, characterised in that the fluid introduction device has a feed line (14) which can be connected to the outlet (17) of the yarn take-off channel (3) and / or arranged adjacent to the outlet (17) of the yarn take-off channel (3).

11. Air-jet spinning device (2) according to claim 9 or 10, characterised in that the fluid introduction device (11a, 11b, 11c) is designed to atomise the fluid.

12. Air-jet spinning device according to one or more of claims 9 to 11, characterised in that the feed line (14) is connected to a yarn guide channel of a yarn preparation unit (31) which is arranged downstream of the outlet (17) of the yarn take-off channel (3) in the yarn running direction.

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