Circular knitting device and method for producing knitted goods

Abstract

The invention relates to a circular knitting device (100, 200, 300, 400, 500, 600) configured for knitting one or more yarns into a tubular knitted fabric (130), wherein one or more plasma sources (2, 150a-d, 250a-b, 350, 450ab, 550, 551) are provided for generating a plasma, in particular a plasma jet (26, 152, 252, 352, 452a-b, 552), which are configured to irradiate the knitted fabric (130) produced in the operation of the circular knitting device (100, 200, 300, 400, 500, 600) with the plasma, in particular with the plasma jet (26, 152, 252, 352, 452a-b, 552). The invention further relates to a system with such a circular knitting device (100, 200, 300, 400, 500, 600) and a method for producing a knitted fabric (130) in which one or more yarns (122) are knitted to form a tubular knitted fabric (130) and in which the knitted fabric is exposed to plasma, in particular a plasma jet (26, 152, 252, 352, 452a-b, 552).

Description

[0001] The present invention relates to a circular knitting device configured for knitting one or more yarns into a tubular knitted fabric. The present invention further relates to a method for producing a knitted fabric.

[0002] Circular knitting devices are used in the prior art to produce tubular knitted fabrics, which can, for example, be cut lengthwise in a further step to obtain a web-shaped knitted fabric.

[0003] Yarns used in circular knitting machines are typically treated with smoothing agents. These agents serve primarily to smooth the yarns, ensuring reliable processing in the circular knitting machine. Typical smoothing agents include, for example, starch, fatty acid polyglycol esters, glycol ether mixtures, fatty acid condensate products, dialkyl polyglycol ethers, oxalkylated fatty acid derivatives, phosphate esters, mineral oil, wax dispersions, and quaternary amines. Because these smoothing agents can interfere with further processing of the knitted fabric, the knitted fabrics are washed after production and usually dried before further processing. This increases the equipment and process complexity involved in the subsequent processing of the knitted fabrics.

[0004] After production, knitwear often undergoes further wet treatments, such as coating or dyeing, which also require subsequent drying. This further increases the equipment and process complexity involved in the further processing of the knitwear.

[0005] Against this background, the present invention aims to provide a circular knitting device and a method for the production of knitted goods that at least partially reduce or avoid the aforementioned disadvantages of the prior art.

[0006] The aforementioned problem is solved according to the invention by a circular knitting device, configured for knitting one or more yarns into a tubular knitted fabric, wherein one or more plasma sources, in particular plasma nozzles, are provided for generating a plasma, in particular a plasma jet, wherein the one or more plasma sources, in particular plasma nozzles, are configured to subject the knitted fabric produced in the operation of the circular knitting device to plasma, in particular to one or more plasma jets.

[0007] It has been found that by exposing knitted fabrics to plasma, in particular a plasma jet, the yarn can be cleaned, especially of hydrating agents, particularly starch. This eliminates the need for subsequent washing and drying of the knitted fabric.

[0008] Furthermore, by exposing the knitted fabric to plasma, particularly with a plasma jet, the surface of the yarns can be activated, resulting in better adhesion for subsequent dyeing or coating processes, such as impregnation. This improved adhesion of the yarn surface also enables the economical use of dry processes, such as dry dyeing, thus eliminating the need for wet processes that require subsequent energy-intensive drying.

[0009] The circular knitting machine is designed for knitting one or more yarns into a tubular knitted fabric. In particular, the circular knitting machine can be designed to knit a large number of yarns, for example approximately 90 yarns, into a tubular knitted fabric.

[0010] The design and operation of a circular knitting device for the production of a tubular knitted fabric is generally known from the prior art, for example from DE 195 10 373 A1.

[0011] The circular knitting device described here has one or more plasma sources, in particular plasma nozzles, for generating a plasma, in particular a plasma jet, wherein the plasma sources are configured to expose the knitted fabric produced during operation of the circular knitting device to the plasma, in particular to the respective plasma jet. The exposure therefore takes place at a point where the one or more yarns have already been knitted into a fabric. Preferably, the knitted fabric is exposed to the plasma, in particular the plasma jet, at a distance from the knitting area of ​​the circular knitting device. The knitting area of ​​the circular knitting device is understood to be the immediate area in which the yarns are knitted into the fabric by means of needles.In this way, the knitting area of ​​the circular knitting device, which is typically subject to greater mechanical stresses, is not affected by the plasma or by substances detached from the yarn by the plasma.

[0012] The mechanics of a circular knitting machine typically cause the tubular knitted fabric to rotate around its longitudinal axis during production. Integrating one or more plasma sources, particularly plasma nozzles, into a circular knitting machine is therefore especially advantageous because the rotational movement of the knitted fabric can be used to apply plasma over a large area, particularly the entire surface. Specifically, the one or more plasma sources, particularly plasma nozzles, can be arranged in a stationary position relative to the housing of the circular knitting machine. The rotational movement of the knitted fabric then moves it away from the plasma sources, particularly plasma nozzles, so that the knitted fabric can be applied plasma over a large area with only a few plasma sources and preferably without any traversing systems for the plasma sources.

[0013] In particular, the circular knitting device can have a ring rotatably driven about an axis, with a plurality of needles, especially tongue needles. The needles are, in particular, displaceable along their respective longitudinal axes and can thus knit the one or more yarns together to form the knitted fabric. The ring with the needles accordingly represents the knitting area of ​​the circular knitting device, in which the one or more yarns are knitted together to form the tubular knitted fabric.

[0014] The rotational movement of the ring with the needles also rotates the continuously formed tubular knitted fabric around its longitudinal axis, preferably at a rotational speed in the range of 20–60 m / min. Due to the rotation of the tube, it is unnecessary to rotate the one or more plasma sources, in particular plasma nozzles, around the longitudinal axis of the ring or the tubular knitted fabric.

[0015] Preferably, several plasma sources, in particular plasma nozzles, are provided, one or more of which are arranged on the outside of the knitted fabric produced in the process, and one or more of which are arranged on the inside of the knitted fabric produced in the process. In this way, the knitted fabric can be treated with plasma on both sides. The one or more plasma sources, in particular plasma nozzles, on the inside are preferably arranged offset from the plasma sources, in particular plasma nozzles, on the outside. In this way, the plasma sources, in particular plasma nozzles, are not directly opposite each other, so that the respective plasma, in particular the plasma jets, can penetrate the knitted fabric more effectively.

[0016] For example, two to four plasma nozzles may be provided, with one or two located on the inside and one or two on the outside of the knitted fabric produced in the factory.

[0017] The aforementioned problem is further solved according to the invention by a method for producing a knitted fabric, preferably carried out with the previously described circular knitting device or an embodiment thereof, in which one or more yarns are knitted to form a tubular knitted fabric and in which the knitted fabric is exposed to plasma, in particular a plasma jet. For generating the plasma, in particular the plasma jet, a plasma source, in particular a plasma nozzle, is preferably used which is configured to generate a plasma, in particular a plasma jet. The knitted fabric can also be exposed to several plasma jets. For this purpose, several plasma nozzles are preferably used, each of which is configured to generate a plasma jet.

[0018] The yarns can be coated with a finishing agent, particularly starch, before knitting. As previously described, the finishing agent can be removed with plasma, especially a plasma jet, making the present process particularly advantageous when using finishing agents. The finishing agent can be, in particular, starch, fatty acid polyglycol esters, glycol ether mixtures, fatty acid condensate products, dialkyl polyglycol ethers, oxalkylated fatty acid derivatives, phosphoric acid esters, mineral oil, wax dispersions, or quaternary amines.

[0019] The following describes various embodiments of the circular knitting device and the method, with each embodiment applying independently to the circular knitting device and the method. Furthermore, the individual embodiments can be combined with one another as desired.

[0020] In one embodiment, the plasma, in particular the one or more plasma jets, is atmospheric plasma, specifically one or more atmospheric plasma jets. This eliminates the need for low-pressure environments. Atmospheric plasma, in particular plasma jet, is understood to be plasma, in particular plasma jet, that operates in the atmospheric pressure range, i.e., especially when applied to the knitted fabric and / or exiting the plasma nozzle, for example, under slight overpressure, entering an environment at atmospheric pressure.

[0021] The atmospheric plasma, in particular the atmospheric plasma jet, can in particular have a pressure in the range of + / - 300 mbar around the surrounding atmospheric pressure, preferably in the range of + / - 200 mbar around the surrounding atmospheric pressure.

[0022] In one embodiment, the one or more plasma sources are provided in the form of one or more plasma nozzles, each with a nozzle opening from which a plasma jet emerges during operation. In particular, each of the one or more plasma sources can be designed as such a plasma nozzle for generating a plasma jet. The plasma nozzles can be configured with a static nozzle opening or as nozzles with a rotating nozzle opening, for example, with a rotating nozzle head. A rotating nozzle opening allows a larger area of ​​the knitted fabric to be exposed to the plasma jet independently of the movement of the knitted fabric towards the plasma nozzle, thus increasing the operating speed of the circular knitting machine.

[0023] In one embodiment, the one or more plasma nozzles are configured to generate the respective plasma jet by means of electrical discharges in a working gas stream, preferably by means of high-frequency, high-voltage discharge, particularly between at least two electrodes of the plasma nozzle. More preferably, the one or more plasma nozzles are configured to generate the respective plasma jet by means of a high-frequency, arc-like electrical discharge in a working gas stream. In a corresponding embodiment of the method, the one or more plasma jets are each generated by means of electrical discharges in a working gas stream, preferably by means of high-frequency, high-voltage discharge, particularly between at least two electrodes. More preferably, the one or more plasma jets are each generated by means of a high-frequency, arc-like electrical discharge in a working gas stream.In this way, a plasma jet is generated that can be focused well and is well suited for the treatment, especially cleaning or activation, of yarns of a knitted fabric.

[0024] To generate the arc-like electrical discharge, at least two electrodes are provided, as well as a voltage source to apply a high-frequency high voltage to the electrodes. The high-frequency high voltage for generating a high-frequency arc-like discharge has a voltage level in the range of 1–100 kV, preferably 1–50 kV, more preferably 10–50 kV, and a frequency of 1–300 kHz, particularly 1–100 kHz, more preferably 10–100 kHz, more preferably 10–50 kHz.

[0025] In one embodiment, particularly the circular knitting device, the device includes a merging device, especially with a roller, designed to flatten the knitted fabric produced during operation. In a corresponding embodiment, particularly the method, the knitted fabric is flattened after being treated with plasma. This facilitates subsequent storage or further processing of the knitted fabric.

[0026] A cutting device can be provided to cut the tubular knitted fabric lengthwise, resulting in a sheet-like knitted fabric. In a corresponding embodiment of the method, the tubular knitted fabric is cut open to create a sheet-like knitted fabric.

[0027] In one embodiment, the one or more plasma sources, in particular plasma nozzles, are configured to expose the knitted fabric produced in the operation of the circular knitting machine to the plasma, in particular to the one or more plasma jets, before it is brought together with the bringing device. In a corresponding embodiment of the method, the knitted fabric is exposed to the plasma, in particular to the one or more plasma jets, before being folded flat together. In this way, the tubular knitted fabric can be exposed to plasma, especially from the inside. Furthermore, the rotation of the tubular knitted fabric can be used for plasma exposure in this way.

[0028] In one embodiment, the one or more plasma sources are arranged within the tubular knitted fabric produced during the manufacturing process. This enables a compact design and a structurally simple utilization of the rotation of the tubular knitted fabric for plasma application.

[0029] In one embodiment, several plasma sources are provided, wherein the plasma sources, in particular plasma nozzles, are configured to impart a plasma jet to the tubular knitted fabric at different angles to its surface. In a corresponding embodiment of the method, the knitted fabric is imparted with several plasma jets at different angles to its surface.

[0030] The angle of the plasma jet to the surface of the knitted fabric at the point of application influences the penetration depth and intensity of the plasma treatment. At an angle of 90°, i.e., with the plasma jet directed perpendicularly to the knitted fabric, the plasma jet penetrates very deeply. At an oblique angle, for example in the range of 30°–45°, the plasma jet has to travel a longer path through the knitted fabric, which can reduce the penetration depth. At the same time, the intensity of the treatment, particularly on the exposed side of the knitted fabric, can be increased. By providing plasma sources, especially plasma nozzles, with different angles to the surface of the knitted fabric, the plasma nozzles with the appropriate angles for the specific application can be selected as needed.Furthermore, plasma nozzles can be operated simultaneously at different angles to achieve good depth penetration and intensive treatment of the affected side of the knitted fabric.

[0031] In one embodiment, a suction device is provided, arranged such that the knitted fabric produced during operation of the circular knitting machine is guided between at least one of the one or more plasma sources, in particular plasma nozzles, and the suction device. In a corresponding embodiment of the method, the plasma applied to the knitted fabric, in particular the plasma jet directed at the knitted fabric, is drawn in from the opposite side of the knitted fabric. By drawing in the plasma from the side opposite the plasma source, the depth of penetration of the plasma, in particular the plasma jet, in the knitted fabric can be improved. In particular, plasma applied to the knitted fabric from one side can be guided deep through the one or more yarns by drawing in the plasma from the opposite side.

[0032] In one embodiment, two half-shells are provided, arranged on opposite sides of the knitted fabric being produced in the process, with one or more plasma sources configured to introduce plasma into the half-shells. In this way, the knitted fabric can be passed through a space filled with plasma on both sides, enabling intensive plasma treatment of the yarns on both sides. Preferably, in this embodiment, the plasma, and in particular the plasma jet, is generated using nitrogen as the working gas. This allows the reactive species of the plasma, distributed within the half-shells, to remain reactive for a longer period.

[0033] In one embodiment, particularly the circular knitting device, a precursor feed is provided which is configured to introduce a precursor into the plasma of at least one of the one or more plasma sources, in particular plasma nozzles. In a corresponding embodiment, particularly the method, a precursor is introduced into the plasma, in particular into at least one of the one or more plasma jets. In this way, the one or more yarns of the knitted fabric can be coated directly in the circular knitting device after knitting.

[0034] In particular, a coating can be created in this way to reduce the surface energy of the yarns, thus resulting in a water-repellent surface. For this purpose, a silicon-organic compound can be used as a precursor. It has been found that the yarns can be impregnated in this way, eliminating the need for fluorinated compounds, especially PEFAS, which are commonly used for impregnation.

[0035] Furthermore, the yarns of the knitted fabric can be provided with a germicidal and / or microbiologically effective coating, in particular an antimicrobial coating. For this purpose, a titanium-organic compound can be used as a precursor.

[0036] Furthermore, the yarns of the knitted fabric can be coated with an adhesive layer. For this purpose, a silicon-organic compound can be used as a precursor.

[0037] In one embodiment, particularly the circular knitting device, a water supply is provided which is configured to introduce water, especially liquid water, into the plasma of at least one of the one or more plasma sources, especially plasma nozzles. In a corresponding embodiment, water, especially liquid water, is introduced into the plasma, especially into the one or more plasma jets. By introducing water into the plasma, especially the plasma jet, the cleaning effect can be increased, particularly for removing rinsing agents. The water can, for example, be introduced into the plasma or the plasma jet at the front end of a nozzle head of a plasma nozzle.

[0038] The aforementioned problem is further solved according to the invention by a system comprising the previously described circular knitting device for producing tubular knitted fabric or one of the previously or subsequently described embodiments thereof, and a dry treatment device configured to dry-treat the knitted fabric produced by the circular knitting device during operation, in particular to dry-dye and / or coat it. In a corresponding embodiment, particularly of the method, the knitted fabric is dry-treated after being exposed to plasma, in particular dyed and / or coated.

[0039] Plasma treatment of the knitted fabric eliminates the need for washing to remove the finishing agent. Preferably, the knitted fabric, which is dry after production, is then further treated dry, thus avoiding complex drying steps. It has also been found that the activation of the yarn surface caused by plasma treatment has a beneficial effect on subsequent dry treatments, particularly dry dyeing, as coating agents, such as dyes, adhere better to the surface-activated yarns.

[0040] The system or an embodiment thereof can be used in particular to carry out the previously described method or an embodiment thereof.

[0041] Further features and advantages of the circular knitting device, the method and the system will become apparent from the following description of exemplary embodiments, with reference to the attached drawing.

[0042] The drawing shows Fig. 1 a plasma source for generating an atmospheric plasma jet by means of a high-frequency arc-like discharge, Fig. 2a-b an embodiment of the circular knitting device and the method, Fig. 3 an alternative configuration of the plasma nozzles of the circular knitting device in a further embodiment of the circular knitting device and the method, Fig. 4 an alternative configuration of the plasma nozzles of the circular knitting device in a further embodiment of the circular knitting device and the method, Fig. 5 an alternative configuration of the plasma nozzles of the circular knitting device in a further embodiment of the circular knitting device and the method, Fig. 6 an alternative configuration of the plasma nozzles of the circular knitting device in a further embodiment of the circular knitting device and the method and Fig. 7 an embodiment of the plant and a further embodiment of the method.

[0043] Fig. Figure 1 shows a schematic sectional view of a plasma source in the form of a plasma nozzle 2 for generating an atmospheric plasma jet 26 by means of a high-frequency arc-like discharge,

[0044] The plasma nozzle 2 has a metal nozzle tube 4 that tapers conically to a nozzle tube opening 5. At the end opposite the nozzle tube opening 5, the nozzle tube 4 has a swirl device 8 with an inlet 10 for a gas flow, in particular a working gas, for example air or nitrogen.

[0045] An intermediate wall 12 of the swirl device 8 has a ring of circumferentially inclined bores 14 through which the gas flow is swirled. The downstream, conically tapered section of the nozzle tube is therefore permeated by the gas flow in the form of a vortex 16, the core of which runs along the longitudinal axis of the nozzle tube. An internal electrode 18 is arranged centrally on the underside of the intermediate wall 12, projecting coaxially into the nozzle tube in the direction of the tapered section. The electrode 18 is electrically connected to the intermediate wall 12 and the other parts of the swirl device 8. The swirl device 8 is electrically insulated from the nozzle tube 4 by a ceramic or quartz glass tube 20. A high-frequency high voltage, generated by a transformer 22, is applied to the electrode 18 via the swirl device 8.The inlet 10 is connected via a hose (not shown) to a working gas source, upstream of which the plasma nozzle 2 is supplied with a working gas flow 23 during operation. The nozzle tube 4 is grounded. The applied voltage generates a high-frequency discharge in the form of an arc 24 between the electrode 18 and the nozzle tube 4.

[0046] The terms "arc," "arc discharge," and "arc-like discharge" are used here as a phenomenological description of the discharge, since the discharge occurs in the form of an arc. The term "arc" is also used elsewhere to describe the discharge type in DC discharges with essentially constant voltage values. However, in this case, we are dealing with a high-frequency discharge in the form of an arc, i.e., a high-frequency, arc-like discharge.

[0047] However, due to the swirling flow of the working gas, this arc is channeled in the vortex core on the axis of the nozzle tube 4, so that it only branches out towards the wall of the nozzle tube 4 in the area of ​​the nozzle tube opening 5.

[0048] The working gas, which rotates at high flow velocity in the region of the vortex core and thus in the immediate vicinity of the arc 24, comes into close contact with the arc 24 and is thereby partially converted into a plasma state. This causes a plasma jet 26, operating at near atmospheric pressure, for example in the pressure range of 800–1300 mbar, to pass through the nozzle tube opening 5 into an outlet nozzle 25 with a nozzle orifice 6 adjacent to the nozzle tube opening. In this case, the outlet nozzle 25 is formed as a single unit with the nozzle tube 4; however, multi-part designs are also conceivable, allowing, for example, the replacement of the outlet nozzle 25. Optionally, a metal grid can be arranged between the outlet nozzle 25 and the conically tapered section of the nozzle tube 4 (at reference numeral 5) to prevent the arc 24 from entering the area of ​​the outlet nozzle 25 or even from exiting it.

[0049] The plasma jet 26 then emerges from the plasma nozzle 2 through the nozzle opening 6 of the outlet nozzle 25.

[0050] The plasma nozzle 2 can optionally be equipped for coating by introducing a precursor into the plasma jet 26.

[0051] In particular, a precursor 28 can be introduced into the plasma jet 26 by a precursor feeder 30 arranged upstream of the outlet of the plasma nozzle 2. Alternatively, it is also conceivable to introduce the precursor 28 into the plasma jet 26 within the plasma nozzle 2, for example, by a precursor feeder 32 inserted into the wall of the plasma nozzle 2 in the region of the outlet nozzle 25, a precursor feeder 34 inserted into the wall of the plasma nozzle 2 in the region of the discharge chamber, or together (see arrow 36) with the working gas 23 through the inlet 10. The respective precursor feeder 30, 32, or 34 can be configured, in particular, to inject, spray, or atomize the precursor 28 in liquid form. It is also conceivable to vaporize the precursor or to use a gaseous precursor.

[0052] It is also conceivable that the plasma nozzle 2 has several precursor feeds with which different precursors can be introduced into the plasma jet 26. The multiple precursor feeds can be arranged at different positions, for example, like the precursor feeds 30 and 32 described above. The precursor feeds can also be introduced into the plasma nozzle 2 at essentially identical positions. For this purpose, for example, two precursor feeds arranged side by side or opposite each other can be provided, like the precursor feeds 32 and 36 in [reference missing]. Fig. 1.

[0053] The Fig. Figures 2a-b show a schematic representation of an embodiment of the circular knitting device and the method. Fig. 2a shows a schematic partial sectional view and Fig. 2b a cross-sectional view according to the one in Fig. 2a, the cutting plane labelled “IIb”.

[0054] The circular knitting device 100 comprises a frame 102 and a circular knitting unit 106 comprising needles 104, which is rotatably mounted on the frame 102 about a central axis 108. Fig. In Figure 2a, the needles 104 are shown exaggeratedly large for illustrative purposes, and for clarity, only a very small number of needles 104 are depicted. In reality, a circular knitting unit 100 typically has a large number of thin needles arranged side by side in the circumferential direction. Below the circular knitting unit 106, a merging device 110 with a deflecting roller 112 and a take-off device 114 with a take-off roller 116 driven by a motor are arranged. The merging device 110 and the take-off roller 116 are rigidly connected to the circular knitting unit 106.

[0055] Furthermore, holders 118 are provided for yarn spindles 120, from which yarn 122 is guided to a respective yarn feed point 124, which is stationary relative to the frame 102, for the circular knitting unit 106. The holders 118 can, for example, be mounted laterally (as in Fig. 2a) and / or be located above the circular knitting unit 106.

[0056] The circular knitting unit 106 comprises a ring 126 in the circumferential direction of which a plurality of needles 104 are arranged transversely to the circumferential direction, in particular parallel to the central axis 108 of the circular knitting unit 106, and are slidably arranged. The circular knitting unit 106 has a mechanism that successively moves the needles 104 back and forth when the circular knitting unit 106 is rotated about the central axis 108, namely out of the ring 126 and back into the ring 126, while the needles 104 pass the area around one of the yarn feed points 124. The needles 104 are designed as tongue needles with a hook 127 and a movable tongue 128.

[0057] In operation, the circular knitting unit 106 is rotated around the central axis 108 by a drive 107, in particular a motor. The yarn 122 is fed from the yarn spindles 120 to the respective yarn feed points 124, where it is picked up by the hooks 127 of the needles 104 extending from the ring 126 and carried along by the needles 104 in the direction of rotation of the circular knitting unit 106. The successive back-and-forth movement of the needles 104 causes each needle 104 to form a stitch at the next yarn feed point 124 when it next picks up the yarn 122. This occurs as the previously picked section of yarn 122 is guided over the outside of the tongue 128 and over the section of yarn 122 newly picked up by the hook 127.

[0058] In this way, the yarns 122 are continuously knitted (interwoven) by the circular knitting unit 106 during operation into a tubular knitted fabric 130, which rotates around the central axis 108 with the circular knitting unit 106.

[0059] The tubular knitted fabric 130 is guided over the deflecting roller 112, which rotates with the circular knitting unit 106, at the merging device 110, so that the tubular knitted fabric 130 is folded flat. The folded knitted fabric 130 is then taken off the merging device 110 by the driven take-off roller 116 and wound up by the take-off device 114.

[0060] The circular knitting device 100 can, for example, be operated with a knitting speed (extension of the tubular knitted fabric 130) of up to 1 m / min. and, for example, with a throughput of up to 20 kg of yarn per hour.

[0061] Between the circular knitting unit 106, in particular the ring 126, and the joining device 110, several plasma sources 150a-d in the form of plasma nozzles are provided to apply a plasma jet 152 to the knitted fabric 130 produced in the process. In the present example, the plasma nozzles 150a-d are arranged such that two plasma nozzles 150a-b are located on the outside 154 and two plasma nozzles 150c-d are located on the inside 156 of the tubular knitted fabric 130 produced in the process.

[0062] The plasma nozzles 150a-d are fixed in position relative to the frame 102. As the knitted fabric 130 rotates around the central axis 108 during production (arrow 109), the surface of the knitted fabric 130 is moved past the nozzle openings 151 of the plasma nozzles 150a-d, so that the entire surface of the knitted fabric 130 on the outside 154 and inside 156 is successively exposed to a plasma jet 152.

[0063] Depending on the thickness of the knitted fabric and the operating mode of the plasma nozzles 150a-d, the plasma jet 152 penetrates the knitted fabric 130 to a certain depth or passes completely through it. Applying the plasma from both the outside 154 and the inside 156 results in a more uniform plasma treatment of the knitted fabric 130. The plasma treatment removes any finish present on the yarn 122 of the knitted fabric 130, thus eliminating the need for subsequent washing and drying of the knitted fabric 130 before further treatment, such as dyeing or waterproofing. Furthermore, the plasma jet 152 plasma-activates the surface of the yarn 122, allowing subsequently applied agents, such as dyes or waterproofing agents, to adhere better to the surface.

[0064] Another embodiment of the circular knitting device is shown using the Fig. Figure 3 illustrates the circular knitting device 200, which has a similar structure and function to the circular knitting device 100. Fig. 2a-b, so that in this respect reference can be made to the above description of the Fig. 2a-b is referred to.

[0065] The circular knitting device 200 differs from the circular knitting device 100 only in the... Fig. 3 shown configurations of the plasma nozzles. Fig. Figure 3 shows a section of one of the Fig. 2b corresponding sectional view.

[0066] In the circular knitting device 200, two half-shells 202, 204 are arranged opposite each other such that the knitted fabric 130 produced during operation is guided through a gap 206 between the half-shells 202, 204. Plasma nozzles 250a-b are connected to the half-shells 202, 204, so that the plasma jet 252 exiting the plasma nozzles 250a-b during operation enters the half-shells 202, 204. The respective volumes 208, 210 of the half-shells 202, 204 are thus filled with plasma. The knitted fabric 130 is moved through the gap by its rotation (arrow 109) about the central axis, so that the surface of the knitted fabric 130 gradually comes into contact with the volumes 208, 210 and thus with the plasma contained therein on both sides. In this way, an effective plasma treatment of the yarn 122 of the knitted fabric 130 is achieved.

[0067] The plasma nozzles 250a-b can each be used like the plasma nozzle 2. Fig. 1. Be trained.

[0068] In addition to the pair of half-shells 212 with the half-shells 202, 204, one or more further pairs of half-shells can be arranged at other locations in the circumferential direction of the knitted fabric 130, for example on the side opposite the pair of half-shells 212 according to the position of the plasma nozzle 150d. Fig. 2b.

[0069] Another embodiment of the circular knitting device is shown using the Fig. Figure 4 illustrates the circular knitting device 300, which has a similar structure and function to the circular knitting device 100. Fig. 2a-b, so that in this respect reference can be made to the above description of the Fig. 2a-b is referred to.

[0070] The circular knitting device 300 differs from the circular knitting device 100 only in the... Fig. 4 plasma nozzle configurations shown. Fig. Figure 4 shows a section of one of the Fig. 2b corresponding sectional view.

[0071] In the circular knitting device 300, a plasma nozzle 350 and a suction device 302 are arranged opposite each other such that the knitted fabric 130 produced during operation is passed between the plasma nozzle 350 and the suction device 302. The suction device has a suction head 304 to which a blower 306 is connected to generate a vacuum at the suction head 304. The plasma jet 352 exiting the plasma nozzle 350 is directed at the knitted fabric 130 and is drawn through it by the suction device 302. In this way, the penetration depth of the plasma jet 352 through the knitted fabric 130 can be increased.

[0072] The Plasma Nozzle 350 can be used like the Plasma Nozzle 2. Fig. 1. Be trained.

[0073] In the present embodiment, the plasma nozzle 350 and the suction device 302 are arranged such that the plasma nozzle 350 is located on the inside and the suction device 302 on the outside of the knitted fabric 130 produced in the process. A reversed arrangement is also conceivable. It is also conceivable that one or more further pairs of a plasma nozzle 350 and a suction device 302, optionally with a reversed arrangement, are arranged at other locations in the circumferential direction of the knitted fabric 130, for example on the opposite side corresponding to the position of the plasma nozzle 150d. Fig. 2b.

[0074] Another embodiment of the circular knitting device is shown using the Fig. Figure 5 illustrates the circular knitting device 400, which has a similar structure and function to the circular knitting device 100. Fig. 2a-b, so that in this respect reference can be made to the above description of the Fig. 2a-b is referred to.

[0075] The circular knitting device 400 differs from the circular knitting device 100 only in the... Fig. 5 shown configurations of plasma nozzles. Fig. Figure 5 shows a section of one of the Fig. 2b corresponding sectional view.

[0076] In the circular knitting device 400, two plasma nozzles 450a, 450b are arranged such that the plasma jets 452a, 452b emerging from the plasma nozzles 450a-b are directed at different angles 454a-b onto the surface of the knitted fabric 130 produced in the process. A steeper angle 454a of the plasma jet 452a to the surface of the knitted fabric 130, for example 90° in the present embodiment, results in a greater penetration depth of the plasma jet 452a into the knitted fabric 130. A shallower angle 454b of the plasma jet 452b to the surface of the knitted fabric 130, for example 45° in the present embodiment, results in a more intensive plasma treatment of the exposed side of the knitted fabric 130.

[0077] The plasma nozzles 450a-b can each be used like the plasma nozzle 2. Fig. 1. Be trained.

[0078] In addition to the plasma nozzles 450a-b, further plasma nozzles can also be provided, for example, at other locations around the circumference of the knitted fabric 130. These additional plasma nozzles can, for instance, be arranged so that they apply the plasma jet to the knitted fabric 130 from the outside. Particularly with plasma nozzles that apply the plasma jet to the knitted fabric 130 at a shallow angle, an arrangement on both sides of the knitted fabric 130 is advantageous to ensure uniform plasma treatment of both sides.

[0079] Another embodiment of the circular knitting device is shown using the Fig. Figure 6 illustrates the circular knitting device 500, which has a similar structure and function to the circular knitting device 100. Fig. 2a-b, so that in this respect reference can be made to the above description of the Fig. 2a-b is referred to.

[0080] The circular knitting device 500 differs from the circular knitting device 100 only in the... Fig. 6 shown configurations of plasma nozzles. Fig. Figure 6 shows a section of one of the Fig. 2b corresponding sectional view.

[0081] The circular knitting device 500 has a plasma nozzle 550, the plasma jet 552 of which is directed at the knitted fabric 130 produced in the operation. The plasma nozzle 550 can be made of the same material as the plasma nozzle 2. Fig. 1. Furthermore, a precursor feeder 502 is provided, with which a precursor 504 - as with the precursor feeder 30 in Fig. 1 - can be introduced into the plasma jet 552 exiting the plasma nozzle 550.

[0082] By using a suitable precursor 504, the knitted fabric can be directly plasma-coated in this way, for example with an adhesion promoter layer or impregnation layer or with dyes.

[0083] The precursor feeder 502 can alternatively also be used - like one of the precursor feeders 32, 34 or 36 in Fig. 1 - can be integrated into the plasma nozzle 550. Alternatively, the precursor 504 can also be introduced into the plasma nozzle 550 with the process gas - as shown in Fig. 1 represented by arrow 36.

[0084] A further plasma nozzle 551 may be provided, for example above or - as in Fig. 6 shown with a dashed line - against the direction of rotation (arrow 109) in front of the plasma nozzle 550, with which the knitted fabric 130 is only exposed to a plasma jet in order to pretreat the yarn 122 before plasma coating, in particular to remove hydrating agents and / or to activate the surface of the yarn 122.

[0085] Instead of the precursor feed 502, a water feed for introducing liquid water into the plasma jet 552 can also be provided. The water feed can be arranged upstream of the plasma nozzle 550, like the precursor feed 502, or alternatively – like one of the precursor feeds 32, 34 or 36 in Fig. 1 - to be integrated into the plasma nozzle. By introducing water into the plasma jet 552, a particularly good cleaning effect can be achieved, especially for removing hydration agents from the yarn 122.

[0086] Fig. Figure 7 shows an embodiment of the system and another embodiment of the method. The system 601 comprises a circular knitting device 600 for producing knitted fabric 130. The circular knitting device 600 can, for example, be like one of the ones described in the Fig. 2a - 6 described circular knitting device 100, 200, 300, 400 or 500.

[0087] The system 601 further comprises a dry treatment unit 602, which is configured to dry-treat the knitted fabric 130 produced by the circular knitting machine 600 in operation, in particular to dry-dye and / or coat it. The dry treatment unit 602 may include an unwinding device for the take-off roller 116. In this way, the circular knitting machine 600 can be operated in a first step to produce knitted fabric 130 and wind it onto the take-off roller 116. Subsequently, in a second step, the take-off roller 116 with the knitted fabric 130 can be inserted into the unwinding device of the dry treatment unit 602, so that the knitted fabric can be unwound from the take-off roller 116 and dry-treated.

[0088] Between the production of the knitted fabric 130 with the circular knitting device 600 and the treatment in the dry treatment device 602, the knitted fabric 130 can be cut lengthwise if necessary, so that a web-shaped knitted fabric is obtained before the knitted fabric 130 is dry treated.

[0089] Since the hydrating agent applied to the yarn 122 for knitting is removed by the plasma treatment in the circular knitting machine 600, washing and subsequent drying of the knitted fabric 130 prior to dry treatment in the dry treatment unit 602 can be omitted, thus saving effort and energy. Furthermore, the plasma treatment can improve the treatability of the knitted yarn 122. For example, dry dyes or impregnating agents can adhere better to the yarn through plasma activation or through an adhesion promoter applied by means of plasma coating. These improved properties of the plasma-treated yarn make some treatment processes possible or economical only as dry processes, thus saving further effort on more complex wet and dry processes. Reference symbol list: 2, 150a-d, 250a-b, 350, 450a-b, 550, 551 plasma source (plasma nozzle) 4 nozzle tubes 5 nozzle pipe openings 6, 151 Nozzle opening 8 Swirl device 10 Admission 12 Partition wall 14 holes 16 vertebrae 18 Internal electrode 20 quartz glass tubes 22 Transformer 23 Working gas flow 24 arcs 25 exhaust nozzle 26, 152, 252, 352, 452a-b, 552 plasma jet 28,504 Precursor or Water 30, 32, 34, 502 Precursor or water supply 36 Arrow 100, 200, 300, 400, 500, 600 circular knitting machine 102 scaffolding 104 needles 106 circular knitting units 107 Drive 108 Central axis 109 Arrow (Rotation of knitwear around the central axis) 110 Merging device 112 Deflection roller 114 Extraction device 116 Take-off roller 118 brackets 120 yarn spindles 122 yarns 124 Yarn feed point 126 wreath 127 hooks 128 Tongue 130 Knitwear 154 Outer surface of the knitwear 156 Inside of the knitwear 202, 204 Half-shell 206 gap 208, 210 volume 212 pairs of half-shells 302 Intake device 304 Intake head 306 blowers 454a-b angle 601 Plant 602 Dry treatment facility QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 195 10 373 A1

[0010]

Claims

[1] Circular knitting device (100, 200, 300, 400, 500, 600), set up for knitting one or more yarns into a tubular knitted fabric (130), characterized by , - that one or more plasma sources, in particular plasma nozzles (2, 150a-d, 250a-b, 350, 450a-b, 550, 551), are provided for generating a plasma, in particular a plasma jet (26, 152, 252, 352, 452a-b, 552), wherein the one or more plasma sources, in particular plasma nozzles (2, 150a-d, 250a-b, 350, 450a-b, 550, 551), are configured to treat the knitted fabric (130) produced in the operation of the circular knitting device (100, 200, 300, 400, 500, 600) with plasma, in particular with one or more plasma jets (26, 152, 252, 352, 452a-b, 552). [2] Circular knitting device according to claim 1, characterized by , that the plasma is atmospheric plasma, in particular one or more atmospheric plasma jets (26, 152, 252, 352, 452a-b, 552). [3] Circular knitting device according to claim 1 or 2, characterized by , that the one or more plasma nozzles (2, 150a-d, 250a-b, 350, 450a-b, 550, 551) are configured to generate the respective plasma jet (26, 152, 252, 352, 452a-b, 552) by means of electrical discharges, in particular by means of arc discharges, in a working gas stream (23). [4] Circular knitting device according to one of claims 1 to 3, characterized by , that the circular knitting device (100, 200, 300, 400, 500, 600) has a ring (126) rotatably driven about an axis (108) with a plurality of needles (104), in particular tongue needles. [5] Circular knitting device according to one of claims 1 to 4, characterized by, that the circular knitting device (100, 200, 300, 400, 500, 600) has a merging device (110), in particular with a roller (112), which is designed to flatten the knitted material (130) produced in the operation of the circular knitting device (100, 200, 300, 400, 500, 600). [6] Circular knitting device according to claim 5, characterized by , that the one or more plasma sources, in particular plasma nozzles (2, 150a-d, 250a-b, 350, 450a-b, 550, 551), are configured to apply plasma, in particular the one or more plasma jets (26, 152, 252, 352, 452a-b, 552), to the knitted fabric (130) produced in the operation of the circular knitting device (100, 200, 300, 400, 500, 600) before it is joined with the joining device (110). [7] Circular knitting device according to any one of claims 1 to 6, characterized by, that the one or more plasma sources (2, 150a-d, 250a-b, 350, 450a-b, 550, 551) are arranged within the tubular knitted fabric (130) produced in the factory. [8] Circular knitting device according to any one of claims 1 to 7, characterized by , that several plasma sources (2, 150a-d, 250a-b, 350, 450a-b, 550, 551) are provided, wherein the plasma sources (2, 150a-d, 250a-b, 350, 450a-b, 550, 551) are configured to act upon the tubular knitted fabric (130) at different angles (454a-b) to the surface of the knitted fabric (130) with a plasma jet (26, 152, 252, 352, 452a-b, 552). [9] Circular knitting device according to any one of claims 1 to 8, characterized by, that an intake device (302) is provided which is arranged such that the knitted material (130) produced in the operation of the circular knitting device (100, 200, 300, 400, 500) is guided between at least one of the one or more plasma sources, in particular plasma nozzles (2, 150a-d, 250a-b, 350, 450a-b, 550, 551), and the intake device (302). [10] Circular knitting device according to any one of claims 1 to 9, characterized by , that two half-shells (202, 204) are provided, which are arranged on different sides (154, 156) of the knitted fabric (130) produced in the factory, wherein the one or more plasma sources (2, 150a-d, 250a-b, 350, 450a-b, 550, 551) are configured to introduce plasma (26, 152, 252, 352, 452a-b, 552) into the half-shells (202, 204). [11] Circular knitting device according to any one of claims 1 to 10, characterized by, that a precursor feed (30, 32, 34, 502) is provided which is designed to introduce a precursor (28, 504) into the plasma, in particular plasma jet (26, 152, 252, 352, 452a-b, 552), at least one of the one or more plasma sources (2, 150a-d, 250a-b, 350, 450a-b, 550, 551). [12] Annex (601), - with a circular knitting device (100, 200, 300, 400, 500, 600) for producing a tubular knitted fabric (130) according to one of claims 1 to 11 and - with a dry treatment device (602) which is equipped to dry treat the knitted fabric (130) produced by the circular knitting device (100, 200, 300, 400, 500, 600) in operation, in particular to dry dye and / or coat. [13] Method for producing a knitted fabric (130), preferably carried out with a circular knitting device (100, 200, 300, 400, 500, 600) according to one of claims 1 to 11 or a system according to claim 12, - in which one or more yarns (122) are knitted into a tubular knitted fabric (130) and - in which the knitted fabric (130) is exposed to plasma, in particular to one or more plasma jets (26, 152, 252, 352, 452a-b, 552). [14] Method according to claim 13, characterized by , that a precursor is introduced into the plasma, in particular the plasma jet (26, 152, 252, 352, 452a-b, 552). [15] Method according to claim 13 or 14, characterized by that the one or more yarns (122) are coated with a finishing agent, in particular starch, before being knitted into the knitted fabric (130). [16] Method according to any one of claims 13 to 15, characterized by, that the knitted fabric (130) is laid flat and / or cut lengthwise into a web-shaped knitted fabric after being treated with plasma (26, 152, 252, 352, 452a-b, 552). [17] Method according to any one of claims 13 to 16, characterized by , that the knitted fabric (130) is dry treated after being exposed to plasma (26, 152, 252, 352, 452a-b, 552), in particular dyed and / or coated.

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