TEXTILE TOOL, TEXTILE TOOL COMBINATION, TEXTILE MACHINE AND METHOD FOR PRODUCE A TEXTILE SURFACE

Description

Technical field

[0001] The present invention relates to a textile tool, a textile tool assembly, a textile machine and a method for producing a textile fabric. Background of the invention

[0002] In the course of automated manufacturing of textile fabrics, textile machines are used that process a large number of individual textile threads together in sometimes different ways in order to produce a textile fabric.

[0003] In the technical field of textile processing, weaving, knitting, and warp knitting machines are known, whose operating principles for processing textile threads differ fundamentally. For example, processing on a weaving machine is achieved by interweaving the textile threads at an angle, with them running alternately over and under each other, whereas processing on a warp knitting machine is achieved by forming loops.

[0004] Notwithstanding these differences, in all thread-processing textile machines the individual textile threads are fed into a working area of ​​the textile machine in which the processing takes place through relative movements of several textile tools in contact with the textile threads.

[0005] During processing, textile tools are affected by the abrasive properties of the textile threads, friction, process forces, chemical substances, etc., leading to wear and tear or changes in the coefficient of friction in contact with the textile threads. This, in turn, affects the accuracy of the thread guidance on the textile tool and also leads to increasing damage to the textile threads, which negatively impacts the quality of the textile fabric. Beyond a certain degree of damage, the textile tools are ultimately unusable and must be replaced. Due to the large number of textile tools in a textile machine, this results in lengthy downtimes.

[0006] Against this background, to increase the durability of textile tools and thus their service life, they feature a coating, at least in the thread-guiding area, that can withstand the aforementioned stresses better than an underlying tool core. The different types of textile threads must also be considered, ranging from very robust threads that cause above-average wear on the textile tools to highly sensitive threads that can be damaged by even the slightest irregularities in contact with the textile tool.

[0007] The coatings applied to the core of textile tools typically comprise a variety of different material layers, the outermost of which is a wear-resistant layer that exhibits higher wear resistance, at least compared to the core material, particularly when paired with a textile thread. The wear-resistant layer should be selected so that it does not damage the textile thread it will later come into contact with and also allows the thread to glide smoothly.

[0008] In addition to the wear-resistant layer, further material layers are used between the tool core and the outermost wear-resistant layer, for example, to improve the adhesion of the coating to the tool core. A multitude of factors must be considered here, such as materials and the respective layer thicknesses, which affect the textile tool in different ways.

[0009] Such a textile tool, designed as a punch needle with several material layers, is known, for example, from DE 4 491 289 C2, in which three material layers are applied to a tool core made of steel, one of which is an outermost carbon layer, acting as a wear-resistant layer.

[0010] Such textile tools are associated with a time-consuming manufacturing process that requires the sequential application of numerous layers of material, each of which is usually intended to adjust a different property of the textile tool, be it mechanical, thermal, or chemical properties.

[0011] Although the large number of material layers improves the suitability of the textile tool for later use in the production of textile fabrics, it has been shown that these textile tools are rather susceptible to chipping or delamination of the coating during use, and also that the large number of material layers leads to a comparatively high reject rate in production.

[0012] Furthermore, a textile tool with a metal nitride coating, in which the nitrogen content in the coating varies, is known from JP S6 228 453 A. Further prior art is also known from EP 0 844 469 A1, which discloses a method for manufacturing mechanically stressed components with a substrate provided with a tribological coating, and from WO 2011 072 664 A1, which shows a coating system with an embedded solid lubricant structure. Summary of the invention

[0013] One object of the present invention is to provide a more economical and durable method for the machine production of textile fabrics compared to the prior art, with which a high product quality of the fabric to be produced can be maintained.

[0014] To solve this problem, a coated textile tool according to claim 1, a textile tool assembly according to claim 13, a textile machine for producing a textile fabric according to claim 14 and a method for producing a textile fabric according to claim 15 are provided.

[0015] The respective dependent claims relate to preferred embodiments, which can each be provided individually or in combination.

[0016] According to a first aspect of the invention, a textile tool for use in a textile machine is provided, comprising a working section for acting on a textile yarn during the production of a textile fabric. The textile tool includes a tool core made of a core material onto which, at least in the working section, a coating for wear protection is applied. The coating comprises a gradient layer composed of a material mixture of at least one first coating material and a wear-resistant material as a second coating material, wherein the concentration of the wear-resistant material varies at least in one thickness direction of the gradient layer. The second coating material is a different material than the first coating material.The core of the textile tool is designed such that the minimum radius of curvature of a surface in the working section of the textile tool is greater than or equal to 40 µm. A minimum radius of curvature of 50 µm is more preferred, and 70 µm is particularly preferred.

[0017] The terms "for wear protection", "wear-resistant" or the like are to be understood in relation to the coating in the context of the invention as meaning that the coating has a higher resistance to material removal and / or a higher strength and / or a higher hardness than the underlying core material from which the tool core is made, usually steel or another metal alloy.

[0018] A coating is understood to be any composite material applied to the existing tool core, particularly one composed of materials different from the core material. This can involve single or multiple layers, which can be applied in any sequence.

[0019] The term "textile fabric" encompasses any textile product, regardless of the specific manufacturing process. Examples include woven fabrics, knitted fabrics, felts, carpets, tufted carpets, nonwovens, bobbins, nets, braids, nonwovens, multi-textiles, and knitted fabrics.

[0020] To produce the textile fabric, a large number of textile threads are processed by the textile tools arranged in a working area of ​​the textile machine (in the case of a knitting machine, for example, by knitting tools such as needles and slide needles), which move relative to each other in the working area, in particular by means of appropriate drives and gears, in order to interlace, link, weave, knit or the like the large number of textile threads together.

[0021] By using the coating that includes the gradient layer, a textile tool with a long service life can be provided.

[0022] The gradient layer thus breaks with the conventional concept of multiple layers applied one on top of the other on the tool core, for example, in the form of an adhesion promoter layer, an indicator layer, or a corrosion protection layer and a wear protection layer applied on top of that, and provides a single layer that combines the advantageous mechanical, physical, or chemical properties of the first coating material with the wear-reducing properties of the wear protection material in a single layer. Examples of the advantageous properties of the first coating material could be the adhesion-enhancing properties of an adhesion promoter material, the chemical resistance-enhancing properties of a corrosion protection material, or an indicator material that facilitates wear detection.

[0023] Every transition between two materials, or between two layers of different materials, represents an interface where the material change causes abrupt changes in various parameters, such as strength and coefficient of thermal expansion. This, in turn, leads to areas where comparatively high mechanical stresses, particularly stress peaks, occur as a result of thermal or mechanical loading of the textile tool. These stresses and stress peaks place considerable strain on the material in these areas, making them prone to failure, for example, in the form of plastic deformation, spalling of individual layers, or cracking.

[0024] In contrast to the example above with adhesion promoter / indicator / corrosion protection layer and separate wear protection layer, the gradient layer provides a coating on the tool core that has one less of the interfaces described above and therefore also fewer areas with increased stresses or stress peaks.

[0025] This results in significantly more uniform stresses occurring in the textile tool due to thermal or mechanical loads (for example, due to different coefficients of thermal expansion), which in turn has a positive effect on the durability of the textile tool.

[0026] This in turn ensures a long service life for the textile tools and thus reduces downtime as well as maintenance costs of the textile machine, since the textile tools now need to be replaced less frequently.

[0027] Furthermore, in contrast to the prior art variant with two separate layers, the gradient layer is only a single layer, which reduces manufacturing times and also the reject rate in production, which in turn saves costs.

[0028] By varying the concentration of the wear protection material in the thickness direction, a particularly uniform transition can be achieved between the properties improved by the first coating material (e.g., adhesion, corrosion protection, indicator) and the wear-reducing properties of the gradient layer.

[0029] The term concentration is to be understood as synonymous with a proportion or mass fraction of a component of the material mixture and can be expressed, for example, in ppm or mass %.

[0030] The thickness direction can be understood as the normal direction running orthogonally to a surface of the gradient layer or to the surface of the underlying tool core at a specific point on the textile tool. Depending on the contour of the textile tool, the thickness directions of different points can be parallel or perpendicular to each other.

[0031] The term "material mixture" is understood to mean that each volume element of the material mixture, or of the gradient layer formed from it, contains both the wear-resistant material and the first coating material. However, this does not preclude the possibility that the concentration of the wear-resistant material may reach a maximum value of 100% by mass or a minimum value of 0% by mass as one approaches the end of the coating, particularly in the thickness direction.

[0032] The concentration varying in the thickness direction is to be understood as meaning that there is at least one point on the gradient layer with respect to which the concentration varies along the associated thickness direction, which corresponds to the point-specific thickness direction through the said point, across the thickness of the gradient layer.

[0033] Accordingly, the concentration of the wear protection material is not constant over the entire thickness of the gradient layer, but is variable and can be specified, for example, via a concentration function as a function of, for example, the absolute or percentage layer thickness in the thickness direction of the gradient layer.

[0034] Preferably, the gradient layer has a surface section with respect to which the concentration varies for each thickness direction of the points located in the surface section. Alternatively, the varying concentration can also be understood as the average value over all points of the surface section. Preferably, said surface section comprises 10 to 100% of the surface area of ​​the gradient layer.

[0035] The tool core of the textile tool is designed such that the radii of curvature of a surface in the working section of the textile tool are greater than or equal to 40 µm, more preferably greater than or equal to 50 µm and particularly preferably greater than or equal to 70 µm.

[0036] In other words, the minimum permissible radius of curvature in the working section is 40 µm, 50 µm, or 70 µm.

[0037] This reduces compressive residual stresses in the coating at the curved areas, which in turn further reduces the risk of the coating chipping.

[0038] The wear protection material serves to protect against wear and has a higher wear resistance than the core material, especially than the core material and the first coating material.

[0039] Wear resistance can be specified via a measurable wear index for resistance to abrasive wear in a material pairing (here with a textile thread). The wear index of the wear-resistant material is higher than the wear index of the core material and, in particular, higher than the wear index of the first coating material.

[0040] The wear indicator can be, for example, a wear rate or a ratio of wear rates.

[0041] The wear rate describes the magnitude of wear per test unit, where the test unit is defined, for example, by test duration (time) or sliding distance. The magnitude of wear for a material pairing can be measured as the volume or mass removed.

[0042] When pairing a material with a textile thread, for example, a test setup can be chosen in which a certain length of textile thread is pulled across a solid coated with the material to be measured using a defined force. The geometry of the solid, the force, and the length of the textile thread should be kept constant for comparability of tests. A measure of the wear resistance of the material being measured is the amount of wear that occurs or the wear rate. The lower the wear or the wear rate, the greater the wear resistance.

[0043] The wear parameter can be the wear measured during the test or the measured wear rate; however, a dimensionless wear parameter in the form of a quotient of the wear of a reference material, in particular hard chrome, to the wear of the material being measured is preferably suitable. A quotient greater than 1 means that the material being measured is more wear-resistant than the reference material, for example, chrome.

[0044] The first coating material is a different material than the wear protection material and can, in particular, be an adhesion promoter material, an indicator material, or a corrosion protection material, as long as it offers improved properties in a selected functional area compared to the core material and / or the wear protection material, e.g., improved adhesion, improved corrosion protection, improved detection, etc.

[0045] If the first coating material is an adhesion promoter, it serves to improve the adhesion of the coating to the tool core and exhibits better adhesion to the core material than the wear-resistant material. This improved adhesion reduces the risk of the coating detaching or chipping.

[0046] Adhesion can be specified via a measurable adhesion value for resistance to layer flaking in a material pairing. The adhesion value of the bonding agent material in relation to the core material is higher than the adhesion value of the wear-resistant material in relation to the core material.

[0047] The adhesion parameter can, for example, be an adhesive strength or a ratio of adhesive strengths.

[0048] The adhesion strength of a coating material to a core material can be determined, for example, using a method according to DIN 4856:2018-02 or a scratch test according to DIN EN 1071-3. The greater the adhesion strength, the better the bond. For the sake of comparability between two coating materials, the same core material is used, in particular the core material of the textile tool.

[0049] The adhesive strength measured in the test can be used as an adhesion parameter. However, a dimensionless adhesion parameter in the form of a quotient of the adhesive strength of the measured material to the adhesive strength of a reference material, especially hard chrome, is preferable. A quotient greater than 1 means that the measured material exhibits better adhesion than the reference material, e.g., chrome.

[0050] If the first coating material is a corrosion protection material, it serves to improve the corrosion protection of the coating and has a higher corrosion resistance than the wear protection material and / or the core material.

[0051] Corrosion resistance can be determined, for example, by means of corrosion resistance measurements, in which the material to be tested is exposed as an object to a corrosion atmosphere (e.g. salt spray, immersion in corrosion solutions, sulfur dioxide environment, specified climatic conditions, water vapor condensate, etc.) and subsequently a corrosion fraction of the entire object is determined.

[0052] If the first coating material is an indicator material, it serves to improve wear detection of the coating. For example, it could be an indicator material for optical wear detection or for electrical wear detection.

[0053] In the case of optical wear detection, the indicator material has a different color than the wear protection material and, in particular, also a different color than the core material, preferably in such a way that the different colors are recognizable with the naked eye.

[0054] Preferably, the concentration of the indicator material varies in the thickness direction of the gradient layer, so that the relative wear state can be inferred or at least estimated from the color gradations in the thickness direction of the gradient layer, i.e., what percentage of the gradient layer has already been worn away in the thickness direction.

[0055] In the case of electrical wear detection, the indicator material may have a different electrical conductivity than the core and / or the wear protection material, in particular a significantly higher or lower conductivity compared to these. A removal of the gradient layer thus leads to comparatively large changes in the conductivity properties, so that a wear condition can be detected by measuring these changes.

[0056] Preferably, the material mixture of the gradient layer comprises a third coating material, which is in particular an adhesion promoter material, an indicator material or a corrosion protection material.

[0057] In this way, the gradient layer can be extended to include two functions, such that, for example, the first coating material is an adhesion promoter material and the third coating material is an indicator material, or the first coating material is an adhesion promoter material and the third coating material is a corrosion protection material, or the first coating material is an indicator material and the third coating material is a corrosion protection material.

[0058] Preferably, the textile tool is a knitting tool, i.e., a textile tool for use in a knitting machine. In particular, but not limited to, this may be a punch needle, a slide needle, a tongue needle, or a knitting plate (see also Figs. 1A to 1C ), but also a slide plate, a piercing comb, a knock-off comb plate or a thread comb lamella.

[0059] Although the coating should be applied at least in the working section, it can also be applied in areas that do not inherently come into contact with the textile yarn. Textile tools typically have a holding section for clamping in the textile machine, with the coating preferably only being omitted in the holding section, thus covering all other areas of the tool core.

[0060] Preferably, the thickness of the gradient layer varies in the working section, so that, for example, stronger wear protection can be implemented at the particularly stressed areas than at less stressed areas.

[0061] The gradient layer in question is preferably produced using a PVD process (physical vapor deposition, or PVD process for short). In this process, the body to be coated, for example, the tool core, is placed in a work chamber, and the materials to be applied—at least the first coating material and the wear-resistant material—are provided in their respective material sources. The materials to be applied are transferred from these sources into the gas phase, unless they are already in gaseous form. By simultaneously transferring the first coating material and the wear-resistant material, a hybrid layer, or a layer consisting of a material mixture, can be deposited on the body to be coated.The ratio of the power supplied to the sources or other gas quantity of a material, which determines the process parameters of the PVD process, allows the ratio of the wear protection material and the first coating material in the gas phase to be set and varied over time in order to achieve the concentration varying in the thickness direction.

[0062] In a preferred embodiment, the concentration of the wear protection material increases in the thickness direction from a tool core-side end of the gradient layer in the thickness direction to a textile thread-side end of the gradient layer on average.

[0063] In this context, "on average" means that an average concentration of the wear protection material over the thickness of the gradient layer, e.g. an integral mean, is greater than a concentration of the wear protection material at the tool core-side end of the gradient layer.

[0064] This increases the wear resistance across the thickness and is on average greater at the textile thread-side end, in order to create the necessary conditions for wear-resistant contact with a textile thread.

[0065] In a preferred embodiment, the concentration of the wear protection material increases monotonically, and in particular strictly monotonically, from the end on the tool core side in the thickness direction to the end on the textile thread side of the gradient layer.

[0066] This results in a particularly smooth transition between the two properties of adhesion and wear resistance across the gradient layer, so that internal stress within the gradient layer itself can also be significantly reduced.

[0067] In a preferred embodiment, in which the first coating material is an adhesion promoter material, the concentration of the adhesion promoter material is maximal at the tool core-side end of the gradient layer.

[0068] In a preferred embodiment, the concentration of the wear protection material is maximal at the textile thread-side end of the gradient layer.

[0069] By maximizing the concentrations of the respective materials, the primary properties of the gradient layer, namely adhesion and wear resistance, are also maximized at the aforementioned points.

[0070] In a preferred embodiment, the concentration of the wear-resistant material at the textile-thread-side end of the gradient layer is between 50 and 100 wt%, particularly between 75 and 100 wt%, and most preferably between 90 wt% and 100 wt%. In particular, the concentration can be 95 wt%, 99 wt%, 99.9 wt%, 99.99 wt%, or 99.999 wt%.

[0071] As a result, the gradient layer at the textile thread-side end predominantly contains the wear-resistant material in the material mixture, thus offering increased wear resistance there.

[0072] Preferably, the concentration of the adhesion promoter material at the textile thread-side end of the gradient layer is between 0 wt% and 50 wt%, more preferably between 0 wt% and 25 wt%, and particularly preferably between 0 wt% and 10 wt%. In particular, the concentration can be 5 wt%, 1 wt%, 0.1 wt%, 0.01 wt% or 0.001 wt%.

[0073] In a preferred embodiment, the concentration of the wear-resistant material at the tool core-side end of the gradient layer is between 0 and 50 wt%, particularly between 0 and 25 wt%, and most preferably between 90 wt% and 100 wt%. In particular, the concentration can be 5 wt%, 1 wt%, 0.1 wt%, 0.01 wt% or 0.001 wt%.

[0074] Preferably, the concentration of the adhesion promoter material at the tool core-side end of the gradient layer is between 50 wt% and 100 wt%, more preferably between 75 wt% and 100 wt%, and particularly preferably between 90 wt% and 100 wt%. In particular, the concentration can be 95 wt%, 99 wt%, 99.9 wt%, 99.99 wt% or 99.999 wt%.

[0075] As a result, the gradient layer at the end facing the tool core predominantly contains the adhesion promoter material in the material mixture, thus providing increased adhesion there.

[0076] In a preferred embodiment, the thickness of the gradient layer is between 0.1 and 20 µm, more preferably between 0.5 and 10 µm.

[0077] In this way, the gradient layer is thick enough to adequately protect the underlying tool core, while at the same time not being so thick as to increase the risk of chipping.

[0078] In a preferred embodiment, the coating contains only the gradient layer, and this is applied directly to the tool core.

[0079] In this way, for the entire tool, with regard to materials that differ from region to region, there is only one interface which could act as a possible source of stress concentrations.

[0080] In a preferred embodiment, the adhesion promoter material is an element or a chemical compound with a cubic crystal system and is in particular selected from the group Cr, CrN, Ti, TiAlN.

[0081] In a preferred embodiment, the adhesion promoter material is an element or chemical compound with a hexagonal crystal system and is in particular selected from the group Ti and AlN.

[0082] These materials are relatively inexpensive and have a particularly good effect on reducing internal stresses at the interface between the tool core and the coating, while also offering good adhesion.

[0083] In a preferred embodiment, the wear protection material is a chemical compound of nitrogen and / or carbon with one or more elements from groups 4, 5, 6, 13 and 14 of the periodic table of elements and is in particular selected from the group AlN, AlTiCrN, CrAlN, Cr 1-x Al x N, CrN, TiN, TiAlN, TiAlCN, TiAlSiN and Al 2 O 3.

[0084] Chromium-containing wear protection materials, such as CrAlN, Cr 1-x Al x N, CrN, are particularly preferred because they allow for high strength and at the same time particularly smooth sliding of textile threads without damaging them.

[0085] Furthermore, tungsten carbide (WC), DLC (diamond-like carbon) or tungsten-doped DLC, abbreviated W-DLC, can preferably be used as a wear protection material.

[0086] W-DLC itself has a high strength compared to the core material and also has smoothing properties to reduce surface roughness, so that a textile thread running over it is less damaged by the roughness.

[0087] Tetrahedrally amorphous carbon (abbreviated: ta-C) can also be used.

[0088] According to a second aspect of the invention, a textile tool assembly is provided, comprising a plurality of textile tools and a holding element. The textile tools are designed according to the first aspect or one of its preferred embodiments and are attached side by side to the holding element.

[0089] In this way, the textile tools for use on the textile machine are provided in composite form, so that several textile tools can be mounted in the textile machine by just one assembly operation, namely the mounting of the holding element in the textile machine, which in turn reduces downtime.

[0090] The holding element can be understood as a kind of holder for the textile tools.

[0091] The textile tools are attached in or to the holding element in a way that is parallel to each other along a first direction with a space provided between them, whereby the attachment can be form-fitting and / or force-fitting and / or material-fitting between the holding element and the respective holding sections of the textile tools.

[0092] The textile tools are preferably attached by immersing them in the liquid material of the holding element and then allowing it to solidify. Alternatively, they can be attached by adhesive bonding, for example with an epoxy resin.

[0093] The retaining element is preferably made of a plastic, in particular a thermoplastic, or a light metal alloy. Lead or zinc can also be used, as these materials have a comparatively low melting point.

[0094] The holding element is designed in such a way as to be received into a corresponding receptacle of the textile tools, for example into receiving sections of a bar of a knitting machine.

[0095] The arrangement density of the textile tools in the first direction ranges from 1 to 100 textile tools, in particular needles, per inch (corresponding to 2.54 cm), depending on the shape of the surface to be produced. Preferably, the arrangement density is between 6 and 70 textile tools, in particular needles, per inch, and particularly preferably between 18 and 50 textile tools, in particular needles, per inch.

[0096] The length of the retaining element in the first direction can be between 0.5 and 50 inches, preferably 0.5, 1, 2, 3, 4, 8, or 16 inches.

[0097] Preferably, it is a needle punch assembly for use in a knitting machine, in which a large number of needle punch assemblies can in turn be attached to a bar of the knitting machine in order to equip it with the needle punches.

[0098] According to a third aspect of the invention, a textile machine for producing textile fabrics is provided, comprising a plurality of textile tools and a working area in which the textile machine processes a plurality of textile threads into a textile fabric by means of the plurality of textile tools. At least one of the textile tools (preferably several and particularly preferably all) is a textile tool according to the first aspect or one of its preferred embodiments.

[0099] In this way, a textile machine is provided that enables the automated production of textile fabrics and offers the advantages described above when using the textile tool according to the invention.

[0100] The textile machine according to the invention is characterized, among other things, by particularly long operating times, since the textile tools themselves have a long service life, as well as by a consistently high manufacturing quality, since damage to the textile threads during processing is kept to a minimum.

[0101] Preferably, the textile machine is a knitting machine (or warp knitting machine) in which the working area is a knitting area in which the textile fabric is produced as knitted material.

[0102] Preferably, the textile machine is a knitting machine in which the working area is a knitting area in which the textile fabric is produced as knitted material.

[0103] According to a fourth aspect of the invention, a method for producing a textile fabric is provided, comprising at least providing a textile machine according to the third aspect or one of its preferred embodiments and processing a plurality of textile threads in the working area of ​​the provided textile machine to form a textile fabric by means of the plurality of textile tools of the textile machine.

[0104] The processing typically involves moving individual textile tools relative to each other in the working area, in particular by means of appropriate drives and gears, in order to interlace, link, weave, knit or the like the multitude of textile threads.

[0105] By using the textile machine with the durable textile tools according to the invention, a large quantity of textile fabrics can be produced before the textile tools need to be replaced.

[0106] Flaking of the coating on textile tools or increased wear typically leads to damage to the guided textile threads, which in turn negatively affects the quality of the resulting fabric. The coating of the textile tool according to the invention significantly reduces the risk of coating flaking while still providing high wear resistance, thus enabling the production of high-quality textile fabrics (without damaged textile threads) over a long operating period.

[0107] Further aspects and their advantages, as well as more specific examples of the aforementioned aspects and features, are described below with the aid of the drawings shown in the attached figures. Figs. 1A to 1C show various embodiments of the textile tool according to the invention in the form of a slide needle, a hole needle and a knitting board. Fig. 2 shows a cross-section through the exemplary embodiment Fig. 1B with a depiction of a coating. Figs. 3A to 3F show exemplary trends in the concentration of the wear protection material in the gradient layer. Detailed character description

[0108] Figs. 1A to 1C show various embodiments of the textile tool according to the invention in the form of a slide needle 1a ( Fig. 1A ), a punch needle 1b ( Fig. 1B ) and a circuit board 1c ( Fig. 1C ).

[0109] All exemplary textile tools 1a, 1b, 1c have a working section 10 for acting on a textile thread and a holding section 20 for clamping in a textile machine.

[0110] The work sections 10 and the holding sections 20 are indicated by the sections marked with dashed lines and are only examples. In particular, the work section 10 of the individual textile tools 1a, 1b, 1c may be larger or smaller than shown.

[0111] The textile tools 1a, 1b, and 1c all have a coating 200 applied to their respective tool cores, which is intended to protect the textile tools 1a, 1b, and 1c from wear. The coating 200 is indicated by the hatched area.

[0112] The coating 200 is applied at least in work section 10 of the respective textile tool 1a, 1b, 1c, but can also extend beyond this, as is the case, for example, in the Fig. 1A and 1B as indicated.

[0113] According to the invention, the coating 200 comprises a gradient layer composed of a material mixture of at least one first coating material, for example an adhesion promoter material, and a wear-resistant material as a second coating material, wherein the concentration of the wear-resistant material varies in a thickness direction of the gradient layer (see also Fig. 2 ).

[0114] Fig. 2 shows a cross-section AA through the embodiment from Fig. 1B in work section 10 there, with a depiction of a coating.

[0115] The coating 200 comprises a gradient layer 210, which is formed from a material mixture of a first coating material, for example an adhesion promoter material, and a wear protection material.

[0116] By using the gradient layer 210, the number of layer interfaces in the textile tool can be reduced compared to the conventional design with separate layers, thereby reducing the number of stress sources and enabling a particularly steady distribution of internal stresses without stress peaks, which significantly reduces the risk of flaking of the coating 200.

[0117] In the third embodiment shown, the concentration of the wear-resistant material is at its maximum at the textile-thread-side end 202 of the gradient layer 210, and the concentration of the first coating material, for example an adhesion promoter material, is at its maximum at the tool-core-side end 201 of the gradient layer 210. However, the concentration profile can also be configured differently.

[0118] As a result, the gradient layer 210 exhibits its maximum wear resistance in contact with the textile thread 2, and at the same time a particularly good adhesion is achieved in the remaining interface to the tool core 100.

[0119] It should be noted that in general, further layers may be arranged between the gradient layer 210 and the tool core 100, for example a pure adhesion promoter layer made of the already used or another adhesion promoter material or an indicator layer.

[0120] Such an indicator layer can be used to detect wear. If the gradient layer 210 is completely worn away, the indicator layer is exposed, which differs from the gradient layer, for example, in color, so that a localized complete wear of the gradient layer 210 can be easily detected visually.

[0121] Alternatively, the indicator layer can be implemented as a conductive layer. If this layer is completely removed after the gradient layer and subsequently after the removal of the conductive layer itself, this can be easily detected by the associated changes in the electrical properties of the textile tool.

[0122] Figs. 3A to 3F The figures show exemplary concentration profiles of the wear protection material in the gradient layer 210 in the thickness direction (arrow direction) at point P. Fig. 2 .

[0123] Point P is chosen arbitrarily and can also be located at a different point in work section 10.

[0124] In the diagrams shown, d denotes the coordinate in the thickness direction starting from the tool core-side end 201 of the gradient layer to the textile thread-side end 202 of the gradient layer 210, where a total thickness at point P is denoted by d*.

[0125] The concentration of the wear-resistant material in the gradient layer 210, which varies in thickness direction, is denoted by Kv and given as a function of the coordinate d. The concentration at the textile-thread-side end 202 is denoted by K*. The concentrations given can be understood as mass percent.

[0126] Fig. 3A shows a linear progression, where the concentration increases linearly from 0 mass-% across the thickness coordinate d to the maximum K* at d=d*.

[0127] Fig. 3Bshows a higher-order polynomial profile, in which the concentration starts from 0 mass-% and increases with a gradient. ∂ K V ∂ d d = 0 = 0 The gradient increases over the thickness d up to the maximum K*. The selected gradient ensures a particularly smooth transition at the interface on the tool core end 201, further reducing the internal stresses occurring there.

[0128] The gradient layer 210 can also be formed with a gradient that disappears at the end 201 on the tool core side with respect to the thickness direction, regardless of whether the concentration of the wear protection material there is 0 mass-% or not.

[0129] Fig. 3CThe diagram shows a section-defined profile in which an initially linear profile transitions to a constant concentration K* and maintains this concentration until the textile-side end 202. In this way, an area with a constant concentration of the wear-resistant material is provided at the textile-side end 202.

[0130] Fig. 3D shows how also Fig. 3A a linear progression in which the concentration at the tool core-side end 201 is not 0 mass-%, but K 0 with 0< K 0 < K*.

[0131] Fig. 3E shows a curve where the concentration starts from 0 mass-% and increases with a gradient. ∂ K V ∂ d d = 0 = 0 increases over the thickness d up to the maximum K* and this also with a gradient ∂ K V ∂ d d = d * = 0 The selected gradients ensure a particularly smooth transition at the interface on the tool core end 201 and also provide an area with at least a section-by-section nearly constant concentration of the wear protection material at the textile thread end. The maximum slope of the concentration profile as a function of thickness d is reached approximately in the middle of the gradient layer 210.

[0132] The gradient layer 210 can also be formed with a gradient that disappears at the textile thread-side end 202 with respect to the thickness direction, even with any other concentration profile.

[0133] Fig. 3F shows one Fig. 3Equalitatively different concentration profile, in which the slope of the concentration profile as a function of the thickness d is greater in the edge areas towards the tool core or textile thread side than in the middle of the gradient layer 210.

[0134] The concentration profiles shown are all implemented continuously in order to ensure a constant progression of internal stresses and thus an improved bond within the coating, in order to prevent, for example, the risk of flaking.

[0135] However, the concentration curve should not be understood as being limited to the curves shown.

[0136] The concentration profiles shown could also represent a concentration profile averaged over the two remaining dimensions of a section of the gradient layer or over the entire gradient layer. In other words, the concentration profiles can also be understood as surface-level, average concentration profiles.

[0137] Above, exemplary embodiments of the present invention and their advantages have been described in detail with reference to the accompanying figures.

[0138] Finally, it is emphasized again that the present invention is in no way limited to the embodiments and features described above. The invention further encompasses modifications of these embodiments, in particular those resulting from modifications and / or combinations of individual or multiple features of the described embodiments within the scope of protection of the independent claims. List of reference symbols

[0139] 1a Slider needle 1b Punching needle 1c Knitting plate 2 Textile thread 10 Working section 20 Holding section 100 Tool core 200 Coating 201 Tool core end 202 Textile thread end 210 Gradient layer

Claims

1. Textile tool (1a, 1b, 1c) for use in a textile machine, which has a working section (10) for acting on a textile thread (2) in the course of producing a textile fabric, wherein the textile tool (1a, 1b, 1c) comprises a tool core (100) made of a core material, to which a coating (200) for wear protection is applied at least in the working section (10), wherein the coating (200) comprises a gradient layer (210), which is constructed from a material mixture of at least a first coating material and a wear protection material as a second coating material, which is a different material than the first coating material, wherein a concentration of the wear protection material varies in a thickness direction of the gradient layer (210), characterized in that the tool core (100) of the textile tool (1a, 1b, 1c) is configured in such a way that a minimum radius of curvature of a surface in the working section of the textile tool (1a, 1b, 1c) is greater than or equal to 40 µm.

2. Textile tool (1a, 1b, 1c) according to Claim 1, wherein the concentration of the wear protection material increases on average in the thickness direction starting from a tool core-side end (201) of the gradient layer in the thickness direction as far as a textile thread-side end (202) of the gradient layer (210).

3. Textile tool (1a, 1b, 1c) according to Claim 2, wherein the concentration of the wear protection material increases monotonically, in particular strictly monotonically, starting from the tool core-side end (201) in the thickness direction as far as the textile thread-side end (202) of the gradient layer (210).

4. Textile tool (1a, 1b, 1c) according to at least one of Claims 1 to 3, wherein the concentration of the wear protection material at the textile thread-side end (202) of the gradient layer (210) is between 50 and 100% by mass, in particular between 75 and 100% by mass.

5. Textile tool (1a, 1b, 1c) according to at least one of Claims 1 to 4, wherein the concentration of the wear protection material at the tool core-side end (202) of the gradient layer (210) is between 0 and 50% by mass.

6. Textile tool (1a, 1b, 1c) according to Claim 5, wherein the concentration of the wear protection material at the tool core-side end (202) of the gradient layer (210) is between 0 and 25% by mass.

7. Textile tool (1a, 1b, 1c) according to at least one of Claims 1 to 6, wherein a thickness of the gradient layer is between 0.1 and 20 µm.

8. Textile tool (1a, 1b, 1c) according to at least one of Claims 1 to 7, wherein the coating (200) contains only the gradient layer (210) and this is applied directly to the tool core (100).

9. Textile tool (1a, 1b, 1c) according to at least one of Claims 1 to 8, wherein the first coating material is an adhesion-promoting material.

10. Textile tool (1a, 1b, 1c) according to Claim 9, wherein a concentration of the adhesion-promoting material at the tool core-side end (201) of the gradient layer (210) is at a maximum and / or the concentration of the wear protection material at the textile thread-side end (201) of the gradient layer (210) is at a maximum.

11. Textile tool (1a, 1b, 1c) according to either of Claims 9 and 10, wherein the adhesion-promoting material is an element or a chemical compound having a cubic crystal system and is selected in particular from the group Cr, CrN, Ti, TiAlN, or wherein the adhesion-promoting material is an element or a chemical compound having a hexagonal crystal system and is selected in particular from the group Ti and AlN.

12. Textile tool (1a, 1b, 1c) according to at least one of Claims 1 to 11, wherein the wear protection material is a chemical compound of nitrogen and / or carbon with one or more elements from groups 4, 5, 6, 13 and 14 of the Periodic Table of the Elements and is selected in particular from the group AIN, AlTiCrN, CrAlN, Cr1-xAlxN, CrN, TiN, TiAlN, TiAlCN, TiAlSiN and Al2O3 .

13. Textile tool assembly, comprising: - a multiplicity of textile tools (1a, 1b, 1c) according to one of Claims 1 to 12; and - a holding element, to which the textile tools (1a, 1b, 1c) are fastened next to one another.

14. Textile machine for producing textile fabrics, at least comprising: - a multiplicity of textile tools (1a, 1b, 1c) according to one of Claims 1 to 12; and - a working region, in which the textile machine processes a multiplicity of textile threads by means of the multiplicity of textile tools (1a, 1b, 1c) to form a textile fabric.

15. Method for producing a textile fabric, comprising: - providing a textile machine according to Claim 14; - processing a multiplicity of textile threads in the working region of the textile machine to form a textile fabric by means of the multiplicity of textile tools (1a, 1b, 1c) of the textile machine.