JP2023552581A - Spinning element of air spinning nozzle for air spinning machine - Google Patents

Abstract

The present invention relates to a spinning element of an air spinning nozzle for an air spinning machine that produces yarn from sliver using an air stream. Air spinning for air spinning machines allows for particularly inexpensive, low maintenance and easy operation of air spinning machines without compromising the quality and strength of the air spun yarn and without the need for frequent cleaning. In order to provide a spinning element of a nozzle and a corresponding air spinning nozzle, the spinning element has at least one surface for guiding fibers and/or fiber threads, and on the surface for guiding fibers and/or fiber threads. An anti-stick coating is located at least partially on the.

Description

The present invention relates to a spinning element of an air spinning nozzle for an air spinning machine that produces yarn from sliver using an air stream, and to an air spinning nozzle equipped with a spinning element.

Generally, during air spinning, the sliver is fed to the air spinning nozzle through a drafting device, and the outer fibers of the sliver are drawn into the air spinning nozzle by the swirling air flow formed by the air nozzle in the vortex chamber of the air spinning nozzle. In the area of the entrance opening of the yarn, it is wound around the inner fiber core, thereby ultimately forming a wrapped fiber, which is important for the desired strength of the yarn. In principle, this can be done with fibers made of different materials, both natural fibers such as cotton, synthetic fibers such as polyester, and mixtures of natural and synthetic fibers. I can do it.

However, when spinning polyester fibers with an air spinning machine, it is necessary in the prior art to apply additives either in the air spinning nozzle itself or on the polyester fibers to be spun. Because only with such additives it is possible to prevent the accumulation of polymer residues, polyester fiber fragments and/or finishing agents inside the air spinning nozzle and in particular on the surface of the spinning cone. It is. However, such deposits significantly interfere with the air spinning process and significantly reduce the spinning result and thus the yarn quality. Particularly during the spinning process, yarn breakage can occur due to the increased friction between the surface of the air spinning nozzle and the fibers. Furthermore, the air nozzle as well as other components of the air spinning nozzle are clogged with deposits, so that the yarn obtained has a relatively low yarn strength and yarn quality.

However, the use of additives also has a series of drawbacks. On the one hand, the use of additives increases production costs, and on the other hand, the additives remain on the air-spun yarn and have to be removed if necessary before further processing of the yarn. Moreover, due to the use of additives, the corresponding components of the air spinning machine must be cleaned regularly, so that excess additives that have accumulated on the components can be removed.

The problem underlying the present invention is therefore to provide an air-spun yarn that can be air-spun without compromising the quality and strength of the air-spun yarn and without creating the need for frequent cleaning of the air-spinning machine components and the air-spun yarn. The object of the present invention is to provide a spinning element of an air spinning nozzle for an air spinning machine as well as a corresponding air spinning nozzle with a spinning element, which allows a particularly inexpensive, low-maintenance and simple operation of the working unit of the spinning machine.

This object is achieved according to the invention by a spinning element of an air spinning nozzle for an air spinning machine according to claim 1 and a corresponding air spinning nozzle with a spinning element according to claim 11. Advantageous embodiments of the invention are defined in the dependent claims.

The spinning element according to the invention of an air spinning nozzle for an air spinning machine for producing fiber threads or threads from slivers by means of an air stream has at least one surface for guiding fibers and/or fiber threads, and has at least one surface for guiding fibers and/or fiber threads. An anti-adhesive coating is located at least partially on the surface guiding the fiber threads.

The air spinning nozzle according to the invention has at least one spinning element according to the invention arranged within the air spinning nozzle. In particular, several and/or different spinning elements according to the invention may also be arranged in and/or at the air spinning nozzle.

The inventor has provided that the effect of the additive is also achieved by a persistent anti-stick coating of at least a part of the air-spinning nozzle or of at least one section of the spinning element of the air-spinning nozzle, and that the additive is omitted in an advantageous manner. It has now been realized that the air spinning process can be carried out significantly more simply, inexpensively and with low cleaning requirements. Furthermore, the anti-stick coating reduces air consumption in an advantageous manner. This is because the same spinning results can be achieved with relatively lower air pressures. Furthermore, due to the relatively large winding fiber angles that can be achieved, higher yarn strengths are achieved in a simple manner. Finally, anti-stick coatings allow increased manufacturing speed.

An air spinning machine is firstly understood to be any spinning machine that uses at least one air stream to wind fibers, in particular wrapped fibers, around an internally located fiber core to form a fiber thread or yarn. be done. The process of yarn formation takes place in the area of an air spinning nozzle, which is formed from one or more spinning elements. A pneumatic spinning machine preferably has at least one working unit or spinning unit which includes a pneumatic spinning nozzle. Each spinning unit works to produce yarn from the sliver fed to the air spinning nozzle. The air spinning nozzle is formed with an inlet for the sliver, a swirling chamber located inside, one or more yarn forming or spinning elements arranged at least partially within the swirling chamber, and an inside of the swirling chamber. and an outlet for the thread. Furthermore, the air spinning nozzle preferably has a plurality of air nozzles opening into the swirling chamber. These air nozzles are particularly preferably fluidly connected to at least one air supply line. During operation of the air spinning machine, compressed air provided from the air supply line flows into the vortex chamber through the air nozzle, thereby creating a vortex for air spinning the sliver in the vortex chamber to form yarn. Air flow can be formed.

A thread or a fiber thread in the sense of the invention is a fiber bundle in which at least some of the fibers are wound around an internally located fiber core. The yarn may be a roving for subsequent processing, for example on a ring spinning machine. The sliver, and thus the thread produced from this sliver, is preferably at least partially, particularly preferably completely, made of synthetic or chemical fibers, for example polyester.

The spinning element can be an independent component, part of a structural unit or a functional unit, which functional unit is preferably directly involved in the air spinning process. . The spinning element may be formed in one piece or in multiple parts. According to the invention, the spinning element is part of or is an air spinning nozzle. Furthermore, preferably, the spinning elements are at least partially in direct contact with the fibers to be spun and/or with the yarn that has just been spun within the framework of the air spinning process. The spinning element may in particular be a constituent part of the swirling chamber and may at least partially form the inner wall of the swirling chamber. Alternatively or additionally, the spinning element may be part of the spinning cone and in this case even part of the outer surface of the spinning cone and/or a drawer inside the spinning cone. It may be at least a part of the passage.

According to the invention, the spinning element has at least one surface for guiding fibers and/or fiber threads. The surface guiding the fibers and/or fiber yarns may initially contact the unspun fiber material and/or the fiber material already spun to form the yarn before, during or after the air spinning process. Any surface of the spinning element where possible. Preferably, the surface guiding the fibers and/or fiber threads is arranged entirely within the air spinning nozzle. Particularly preferably, the fiber and/or yarn guiding surface is arranged at least partially and very particularly preferably completely within the vortex chamber of the air spinning nozzle. Within the swirling chamber, unspun fibers are swirled to form yarn.

A sliver is basically a fibrous material that is fed into an air spinning process, which fibrous material is preferably provided as one coherent band or composite of fibers to be spun. All fibers may be formed from the same material, or the sliver may contain fibers that are chemically different from each other. But basically the fibers within the sliver are not yet spun together.

An anti-adhesion coating is primarily a coating of a surface to reduce the static and/or sliding friction between the coated surface or the surface of the coating and the yarn or individual fibers. The anti-adhesion coating preferably has a continuous and/or closed surface. More preferably, the surface of the anti-adhesion coating is smooth. The anti-adhesive coating may be formed from essentially any material, and the anti-adhesive coating is preferably formed from at least one polymer. Particularly preferably, the anti-adhesive coating comprises a thermoplastic polymer, and very particularly preferably, the anti-adhesive coating is substantially formed from a thermoplastic polymer.

In addition to reducing the stiction and/or sliding friction, the anti-adhesion coating preferably also provides a hydrophobic and/or oleophobicized surface, which prevents the adhesion of water- and/or oil-soluble substances. be done. Preferably, the anti-adhesive coating has an anti-static effect, so that the coated surface and the fibers or air-spun yarns to be spun do not accumulate on the surface of the spinning element due to friction. This accumulation may lead to deterioration in spinning results.

Application of the anti-adhesive coating can likewise be carried out in any manner. For example, the anti-stick coating may be sprayed and/or fused onto the surface of the spinning element. Particularly preferably, the material of the anti-adhesive coating is applied as a powder or dispersion to the surface to be coated and then particularly preferably melted together with or on this surface. The deposition of the anti-adhesive layer on the surface of the spinning element can also take place by chemical bonding and/or purely physically. Furthermore, binders and/or adhesives can be used for this purpose.

According to the invention, at least one section of the surface guiding the fibers and/or fiber threads is coated with an anti-adhesive coating. Disconnected sections of the surface guiding the fibers and/or fiber threads can also each have an anti-adhesion coating. Furthermore, several components of the air spinning nozzle may have an anti-adhesive coating, preferably partially on the entire inner surface within the swirling chamber.

A preferred configuration of the spinning element according to the invention provides that the anti-adhesive coating has a lower coefficient of friction than the material of the spinning element located below the anti-adhesive coating, which provides advantages. On the one hand, it is prevented that the additives present on the fibers and/or fibers or threads remain stuck, and on the other hand, an improved sliding of the fibers on the surface of the spinning element is achieved. In particular, if the spinning cone is a surface-coated spinning element, advantageously higher rotational speeds of the fibers on the spinning cone can be achieved. Preferably, the surface of the anti-adhesive coating has a coefficient of friction that is at least 10%, particularly preferably 25% and very particularly preferably 50% lower than the material of the spinning element, in particular in the area below the anti-adhesive coating. have.

In order to ensure particularly low static and/or sliding friction between the spinning elements and the fibers or yarns, the coefficient of friction of the surface guiding the fibers and/or fiber yarns, which preferably has an anti-adhesive coating, is It is less than 0.4, preferably less than 0.35, particularly preferably less than 0.3.

According to an advantageous development of the spinning element according to the invention, the anti-adhesive coating is made of a fluorinated hydrocarbon or fluorinated hydrocarbon polymer, in particular polytetrafluoroethylene (Teflon, PTFE) and/or a perfluoroalkoxyalkane polymer. or from perfluoroalkoxy polymers (PFA) and/or from fluoroethylene-propylene polymers or tetrafluoroethylene-hexafluoropropylene copolymers (FEP). The anti-adhesion coating preferably has a proportion of PTFE, FEP and/or PFA of more than 50% and is particularly preferably formed from PTFE, FEP and/or PFA to at least 90%. In addition to PTFE, FEP and/or PFA, the anti-adhesion coating may also contain further polymers and/or auxiliaries, preferably in an amount of 5% with respect to the total weight of the applied anti-adhesion coating. It cannot be surpassed. Preferably, the anti-adhesive coating has PTFE as a main component, and particularly preferably consists essentially of PTFE. This is because PTFE typically has a coefficient of friction of about 0.25 and a friction value of less than 0.05. PFA, which is somewhat mechanically softer, typically has a somewhat lower coefficient of friction of about 0.2 to 0.25, and FRP has higher strength than PTFE, but also has a slightly higher coefficient of friction. ing.

In a preferred embodiment of the spinning element according to the invention, the surface for guiding the fibers and/or fiber threads is a surface section of at least one of the spinning cone and/or needle and/or tweezers of the air spinning nozzle, whereby the Fiber deposition, preparative deposition and/or polymer deposition can be avoided. Particularly preferably, the spinning elements are spinning cones and/or needles and/or tweezers of air spinning nozzles. It is likewise preferred that the entire surface guiding the fibers and/or fiber threads or the surfaces of the spinning cones and/or needles and/or tweezers that can come into contact with the fibers and/or threads are coated with an anti-adhesive coating. has been done. Particularly preferably, however, at least the tip of the spinning cone, on which the fibers are wound to form the air-spun yarn, is coated with an anti-adhesive coating.

Particularly preferably, the spinning element is a spinning cone, the surface of which guides the fibers and/or the fiber threads, at least in the region of the tip, preferably in the direction of yarn withdrawal of the spinning cone. Particularly preferably over at least 10% of the extending length, particularly preferably over at least 25%, very particularly preferably over at least 50% and even more preferably over at least 10% along the circumferential direction of the spinning cone. has an anti-stick coating over at least 25%. Furthermore, the spinning cone may have an anti-adhesion coating on the surface guiding the fibers and/or fiber yarns or over the entire length of the spinning cone in the yarn draw-off direction and/or in the circumferential direction.

The surfaces guiding the fibers and/or the fiber yarns may be arranged arbitrarily relative to the yarn or sliver passing through the air spinning nozzle; the surfaces guiding the fibers and/or the fiber yarns can be According to an advantageous refinement, it is a surface surrounding the thread and/or sliver. Surrounding in this context means that the yarns and/or slivers are at least partially surrounded by a surface guiding the fibers and/or fiber yarns in the interior of the air spinning nozzle; or the fiber thread-guiding surface preferably surrounds the thread and/or sliver by at least 90°, particularly preferably at least 180°, very particularly preferably at least 270°, particularly preferably completely surrounding the thread and/or sliver. There is.

Particularly preferably, the surface surrounding the yarn and/or sliver is the inner wall of the air-spinning nozzle, in particular the inner wall of the swirling chamber, whereby advantageously the deposition on the inner wall is particularly advantageous in the region of the nozzle hole opening leading into the swirling chamber. is prevented, thereby maintaining the air flow rate for forming the air spun yarn. In principle, only part of the inner wall of the air spinning nozzle, in particular the swirling chamber, may be coated, preferably at least one part of the inner wall with the nozzle hole opening, particularly preferably the inner wall. The whole has an anti-stick coating.

In principle, the anti-adhesive coating of the spinning element may have any thickness and any structure. Preferably, however, the anti-adhesion coating has a layer thickness of 2 μm to 2 mm, preferably 5 μm to 500 μm, particularly preferably 10 μm to 200 μm, very particularly preferably 10 μm to 150 μm; On the one hand, the surface properties can be positively influenced, and on the other hand no changes in the geometry within the air-spinning nozzle occur due to the anti-adhesive coating. Furthermore, the anti-adhesion coating preferably has a homogeneous structure throughout the layer thickness.

Besides reducing stiction and sliding friction, the anti-stick coating may also have any other functions. Particularly preferably, the anti-adhesive coating has an anti-static surface, so that the spinning element is particularly suitable for polymer fibers and plastic fibers, especially polyester fibers. This is because the fibers do not become electrostatically charged on the plastic surface and/or do not remain attached to the plastic surface.

An embodiment of the spinning element according to the invention will be explained in detail below with reference to the drawings.

1 is a schematic perspective view of the components of an air spinning nozzle including a spinning element with an anti-stick coating; FIG.

In the air spinning nozzle 2 of the air spinning machine, which is diagrammatically illustrated in FIG. The fibers located at can be swirled around the fiber core to form a thread 3 in the process.

For this purpose, the air spinning nozzle 2 has a plurality of spinning elements 1 . These spinning elements 1 each have a surface 5 for guiding the fibers or fiber threads. One of the spinning elements 1 is a needle 9 having a fiber-guiding surface and arranged in the region of the fiber inlet opening of the air spinning nozzle 2, while another spinning element 1 A spinning cone 8 which, in the region of its tip, has a surface 5 for guiding the fibers and fiber threads.

In order to reduce the static and sliding friction between the spinning elements 1 and thus obtain a higher winding fiber angle and therefore higher yarn strength, at least the tips of the spinning cones 8 are provided with an anti-adhesive coating 6. This anti-adhesion coating 6 is a polytetrafluoroethylene (Teflon, PTFE) coating. This polytetrafluoroethylene coating, according to this preferred embodiment, is applied planar and with a smooth surface onto the material 7 of the spinning cone 8 and in this case the material 7 of the spinning cone 8. It has a significantly lower coefficient of friction than 7. As an alternative to the Teflon coating, the coating is made, according to another preferred embodiment, for example from a perfluoroalkoxyalkane polymer or a perfluoroalkoxy polymer (PFA), or from a fluoroethylene-propylene polymer or a tetrafluoroethylene-hexafluoro It may be formed from propylene copolymer (FEP) or from a mixture of the above-mentioned coatings.

In addition to at least one surface section of the spinning cone 8 , the part of the needle 9 that comes into contact with the sliver 4 may also have an anti-adhesive coating 6 . This anti-adhesion coating 6 is likewise preferably made from a fluorinated hydrocarbon or fluorinated hydrocarbon polymer, in particular polytetrafluoroethylene (Teflon, PTFE) and/or from a perfluoroalkoxyalkane polymer or perfluoroalkoxypolymer (PFA). , and/or formed from fluoroethylene-propylene polymer or tetrafluoroethylene-hexafluoropropylene copolymer (FEP).

In addition to the fiber and/or fiber thread guiding surfaces 5 mentioned above, the surfaces surrounding the sliver 4 and/or the threads 3, in particular at least a part of the inner wall of the air spinning nozzle 2, and particularly preferably, The inner wall of the swirling chamber can likewise have an anti-adhesive coating 6, which very preferably has the same chemical composition as the anti-adhesive coating 6 of the spinning element(s) 1. There is.

1 Spinning element 2 Air spinning nozzle 3 Yarn 4 Sliver 5 Surface guiding the fibers and/or fiber threads 6 Anti-stick coating 7 Material 8 Spinning cone 9 Needle 10 Feeding roller pair

Claims (11)

A spinning element (1) of an air spinning nozzle (2) for an air spinning machine producing yarn (3) from a sliver (4) using an air stream, comprising:
- with at least one surface (5) for guiding fibers and/or fiber threads;
- a spinning element (1) whose surface (5) guiding the fibers and/or fiber threads has at least partially an anti-stick coating (6); Spinning according to claim 1, characterized in that the anti-adhesive coating (6) has a lower coefficient of friction than the material (7) of the spinning element (1) located below the anti-adhesive coating (6). Element (1). Spinning element (1) according to claim 1 or 2, wherein the thread and/or fiber thread guiding surface (5) provided with the anti-adhesion coating (6) has a coefficient of friction of less than 0.3. 4. Textile according to claim 1, wherein the anti-adhesive coating (6) is formed from polytetrafluoroethylene or from a perfluoroalkoxy polymer or from a tetrafluoroethylene-hexafluoropropylene copolymer. Element (1). Claim in which the fiber and/or fiber thread guiding surface (5) is a surface section of at least one of the spinning cone (8) and/or needle (9) and/or tweezers of the air spinning nozzle (2). Spinning element (1) according to any one of items 1 to 4. Said spinning element (1) is a spinning cone (8), the surface of said spinning cone (8), in particular for guiding fibers and/or fiber threads, at least in the region of the tip, of said spinning cone (8). an anti-adhesive coating (6) over at least 25% of its length in the direction of yarn withdrawal and along at least 25% along the circumferential direction of said spinning cone (8); Spinning element (1) according to any one of claims 1 to 5, wherein the spinning element (1) has an inlet opening for accommodating the spun yarn in a withdrawal channel defining the yarn withdrawal direction. Spinning element according to any one of claims 1 to 6, wherein the fiber and/or fiber thread guiding surface (5) is a surface surrounding the thread (3) and/or the sliver (4). (1). Spinning element (1) according to claim 7, wherein the surface surrounding the yarn (3) and/or the sliver (4) is an inner wall of an air spinning nozzle (2), in particular an inner wall of a swirling chamber. Spinning element (1) according to any of the preceding claims, wherein the anti-adhesive coating (6) has a layer thickness of 10 μm to 200 μm. Spinning element (1) according to any one of claims 1 to 9, wherein the anti-adhesive coating (6) has an anti-static surface. An air spinning nozzle (2) for an air spinning machine, comprising at least one spinning element (1) according to one of claims 1 to 10, arranged in the air spinning nozzle (2). It is equipped with an air spinning nozzle (2).

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