Method for yarn inline processing, and system having processing unit therefor and control unit constituted so as to determine whether or not maintenance sequence is required

Abstract

To provide a system and a method for yarn inline processing so as to be used with a yarn consumption device.SOLUTION: A system comprises: a processing unit having at least first and second print heads (151a, 151b) constituted so as to dispense one or a plurality of coating substances at least onto one yarn during operation of them; and a control unit constituted so as to determine whether or not a maintenance sequence should be executed at least on the first print head (151a) and, if the maintenance sequence should be executed, schedule the maintenance sequence at least on the first print head (151a).SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to the technical field of thread consuming devices, in particular to a system comprising a processing unit for use in connection with such a thread consuming device. [Background technology]

[0002] It has been proposed to provide thread consuming devices, such as embroidery machines, with in-line devices designed to provide a specific treatment to the thread. Such in-line devices could be used, for example, to color the thread, whereby multiple color nozzles could replace the current use of multiple pre-colored threads when the embroidery machine is used to create a multi-color pattern. In prior art systems where different colored threads are used, one thread having a first designated color is used for some stitches and another thread having a second designated color is used for other stitches.

[0003] In order to eliminate the obvious drawback of the requirement for multiple yarns of different colors, the applicant has filed several patent applications relating to the technique of in-line coloring of yarns, such as US Pat. No. 5,399,433 and US Pat. No. 5,499,433. The proposed solutions offer improvements in terms of color quality and also reduce the complexity of the yarn consuming device.

[0004] However, to further improve the quality and efficiency of in-line yarn coloring, it would be advantageous if an in-line coloring apparatus could more efficiently perform maintenance of one or more nozzles of the in-line coloring apparatus. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2016 / 204687 Brochure [Patent Document 2] International Publication No. 2016 / 204686 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to provide a solution that overcomes the disadvantages of the prior art. More specifically, the present invention provides a solution in which a system for in-line processing of yarns is configured to determine when a maintenance sequence is necessary for one or more nozzles and to perform the maintenance sequence based on said determination. [Means for solving the problem]

[0007] In a first aspect, a system for in-line processing of yarns for use with a yarn consuming device is provided, the system comprising at least two printheads, each configured to dispense one or more coating substances onto at least one yarn upon operation, and a control unit configured to determine whether a maintenance sequence should be performed on at least a first printhead, and if so, to schedule said maintenance sequence on at least the first printhead.

[0008] The control unit may be configured to perform maintenance of the at least one print head without stopping the thread consumption of the thread consuming device. The ability to perform maintenance without stopping the thread consumption of the thread consuming device has several advantages, as it increases the effectiveness and reduces the need for an operator. Thus, the system provides the advantage of being able to perform maintenance without interfering with the thread consuming device.

[0009] The system can have one or more printheads placed in an operational mode while one or more printheads are placed in a maintenance mode. The control unit can be further configured to perform said maintenance at scheduled times.

[0010] The control unit is configured to receive a current operating speed of the yarn consuming device and determine, based at least on the current operating speed, whether to perform a maintenance sequence.

[0011] The control unit is further configured to receive a thread consumption of the thread consuming device and to determine, based at least on said thread consumption, whether to perform a maintenance sequence.

[0012] The control unit is further configured to determine, based at least on the predetermined operating pattern, whether to execute a maintenance sequence.

[0013] The control unit is further configured to determine whether a maintenance sequence should be performed based at least on the estimated consumption of the coating substance.

[0014] The control unit is further configured to determine a time interval for said maintenance and to decide, based at least on said time interval, whether to perform a maintenance sequence.

[0015] In one embodiment, the maintenance sequence is performed without stopping the thread consumption of the thread consuming device.

[0016] The control unit is further configured to perform a maintenance sequence of at least a first print head by moving the first print head from a first position to a second position, thereby deactivating the print head from dispensing coating substance onto the at least one yarn.

[0017] In one embodiment, at least a second printhead is disposed at a first location and the first printhead is disposed at a second location, the first location can be an operating location and the second location can be a maintenance location.

[0018] In one embodiment, each print head comprises a plurality of nozzles positioned at different positions relative to at least one yarn, said at least one yarn being in motion during use, and each nozzle is configured to dispense one or more coating substances onto the at least one yarn upon actuation.

[0019] The control unit may be further configured to vary the number of active nozzles based on an operation speed of the yarn consuming device and / or an operation speed of the processing unit. The control unit may be further configured to vary the number of active nozzles based on an action that is based on a characteristic of the coating material.

[0020] The nozzle may be an inkjet nozzle.

[0021] The system according to the first aspect may further comprise a yarn consuming device.

[0022] The thread consuming device may be an embroidery machine, a sewing machine, a knitting machine, a weaving machine, a tufting machine, a thread winding machine, or any combination thereof.

[0023] The system further comprises a thread buffer system disposed downstream of the at least two printheads.

[0024] The control unit may further be configured to fill the thread buffer system when it is determined that a maintenance sequence should be performed.

[0025] The system further comprises a thread feeder disposed upstream of said printhead, the control unit being configured to stop the thread feeder when the control unit determines that said maintenance sequence should be performed.

[0026] In one embodiment, during a maintenance sequence, a thread consuming device consumes thread from the buffer.

[0027] In a second aspect, a method for in-line treatment of at least one yarn is provided, the method comprising the steps of providing a treatment unit comprising at least a first and a second printhead, each configured to dispense one or more coating substances onto at least one yarn upon operation, and providing a control unit configured to determine whether a maintenance sequence should be performed on at least the first printhead, and if so, to schedule said maintenance sequence on at least the first printhead.

[0028] The method may further include the step of executing a scheduled maintenance sequence.

[0029] In a third aspect, a system for in-line treatment of a yarn for use in a yarn consuming device is provided, the system comprising at least one discharge device configured to dispense one or more coating substances onto at least one yarn upon operation, and a control unit configured to schedule maintenance of said at least one discharge device without stopping yarn consumption of the yarn consuming device. The system further comprises a yarn buffer system arranged downstream of the at least one discharge device and the control unit. The control unit is further configured to fill the buffer system when it is determined that a maintenance sequence should be performed.

[0030] The system may further comprise a thread feeder arranged upstream of the discharge device, the control unit being configured to determine that a maintenance sequence should be performed and to stop the thread feeder when the control unit determines that the maintenance sequence should be performed.

[0031] During a maintenance sequence, the thread consuming device may consume thread from the buffer.

[0032] (definition) In this context, a "yarn consuming device" is any machine that consumes yarn when in use, such as an embroidery machine, a weaving machine, a sewing machine, a knitting machine, a weaving machine, a tufting machine, a yarn winding machine, or any other yarn consuming machine that can benefit from a surface treatment or coating, or other process that involves exposing the yarn to a substance, such as dyeing.

[0033] In this context, "treatment" is any process designed to modify the properties of the yarn, including, but not limited to, coloring, wetting, lubricating, washing, fixing, heating, curing, dyeing, etc.

[0034] In this context, a "yarn" is a flexible, elongated member or substrate that is thin in width and height and has a longitudinal extension that is much longer than the longitudinal extension of any part of the system described herein and much longer than its width and height dimensions. Typically, a "yarn" may be composed of multiple plies twisted together. Thus, the term "yarn" includes yarns, wires, strands, filaments, etc., made from a variety of different materials, such as fiberglass, wool, cotton, synthetic materials such as polymers, metals, polyester, viscose, or mixtures of, for example, wool, cotton, polymers, or metals, or any combination thereof.

[0035] All references herein to "upstream" and / or "downstream" should be interpreted as relative positions during normal operation of the yarn consuming device, i.e. when the device is operating to process an elongated substrate such as a yarn that moves continuously through the device in a normal direction of operation. Thus, the upstream component is positioned such that a particular portion of the yarn passes through the upstream component before passing through the downstream component.

[0036] Embodiments of the present invention are described in the following description of the invention with reference to the accompanying drawings which show non-limiting examples of how the inventive concepts can be put into practice. [Brief description of the drawings]

[0037] [Figure 1a] FIG. 1 is a schematic diagram of a system for in-line processing of yarn according to one embodiment. [Figure 1b] FIG. 1 is a perspective view of a system having a yarn consuming device and a processing unit according to one embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a processing unit for use with a system according to one embodiment. [Diagram 3] FIG. 2 is a schematic diagram of an ejection device forming part of the processing unit; [Figure 4a] FIG. 2 is a schematic top view of a portion of a discharge device according to one embodiment. [Figure 4b] FIG. 2 is a schematic top view of a portion of a discharge device according to one embodiment. [Figure 5a] FIG. 2 is a schematic diagram of a portion of a processing unit according to one embodiment. [Figure 5b] 1 is a schematic diagram of a method according to one embodiment. [Figure 6] FIG. 2 is a schematic diagram of a processing unit with multiple drive units according to one embodiment. [Figure 7] FIG. 2 is a schematic diagram of a processing unit with a drive unit according to an embodiment. [Figure 8] FIG. 2 is a schematic diagram of a processing unit with multiple drive units having one common motor according to one embodiment. [Figure 9a] FIG. 1 is a schematic diagram of a system according to one embodiment. [Figure 9b] FIG. 1 is a schematic diagram of a system according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] The idea of ​​the present invention is to provide a system and method for distributing a coating substance to a thread in a controlled manner for use in connection with a thread consuming device. Starting from FIG. 1a, a schematic diagram of a system 10 for in-line processing of threads is shown. The system 10 comprises a processing unit 100 for distributing one or more coating substances to at least one thread. The system 10 further comprises at least one thread consuming device 15, which may be in the form of, for example, one or more embroidery machines, weaving machines, sewing machines, knitting machines, tufting machines, thread winding machines, etc. The system thereby forms a thread consuming unit comprising at least one thread consuming device 15 and the processing unit 100. It should be noted that in the thread consuming device, multiple threads can be used.

[0039] It should be noted that several aspects of the system are described herein that do not require the inclusion of a yarn consuming device 15. As will be further understood below, in all embodiments, the system for in-line processing of yarn requires a processing unit 100 to be used in conjunction with a yarn consuming device 15.

[0040] Turning now to Fig. lb, the thread consuming device 15 is exemplified as an embroidery machine, here shown as a single-head embroidery machine with a processing unit 100. The embroidery machine comprises a movable stage 2b which carries the fabric to be embroidered. During operation, the movable stage 2b is controlled to rapidly change its position in the X and Y directions (i.e. in the horizontal plane in this case, but could also be, for example, in the vertical plane).

[0041] The processing unit 100 enables the embroidery machine 15 to operate without providing a unique pre-colored thread, as is required in conventional embroidery machines. Instead, the processing unit 100 provides in-line coloring of the thread 20 according to a predetermined coloring pattern so that colored embroidery can be produced. Thus, the processing unit 100 replaces individual thread reels, as exist in prior art systems.

[0042] As shown in Figure 1b, the only connections between the processing unit 100 and the embroidery machine 15 are the thread 20 and also the electrical connections (not shown). Thus, the processing unit 100 is provided as a stand-alone unit with no mechanical connection to the moveable stage 2b.

[0043] In an optional embodiment, the stand-alone processing unit 100 is mounted to the yarn consuming device 15 via a suspension arrangement to reduce the transmission of vibrations to the processing unit 100 .

[0044] The thread consuming device 15 is arranged to apply a stitch to the substrate. In this context, a stitch can be, for example, one turn of thread, one loop of thread, one turn of yarn, or one loop of yarn. The stitch can be applied, for example, using sewing, knitting, embroidery, crochet, and / or needle lace making. The substrate is preferably a textile, fabric or cloth. In one embodiment, the substrate has a fixed set of properties, for example a specific thickness and elastic constant.

[0045] The various components of the processing unit 100 are shown in FIG. 2. As can be seen in FIG. 2, most of the components are located inside the housing 105. Immediately downstream of the thread reel 120, a thread feeder 130 may be located, configured to pull the thread forward through the processing unit 100. The thread feeder 130 will not be described further herein, but for a more general understanding, the thread feeder 130 receives and advances the thread 20. To this end, the thread feeder 130 may be controlled by a control unit 190, which is further described below. The thread feeder 130 is also preferably configured to control the thread tension, for example by a driven roller, an encoder wheel, and one or more thread guides. After passing through the thread feeder 130, the thread 20 engages a thread guiding device 140.

[0046] The yarn guiding device 140 may be in the form of, for example, one or more guide rollers 142, 144 or other suitable means to ensure that the yarn 20 is aligned with one or more processing nozzles forming part of at least one discharge device 150.

[0047] The discharge device 150 is configured to discharge a treatment substance, such as a coloring substance, onto the yarn 20 as the substance passes through the discharge device 150. To this end, the nozzles are preferably arranged in the longitudinal direction of the yarn 20, as will be further described in relation to Figures 3 and 4.

[0048] The discharge device 150, or parts of the discharge device 150, such as the print heads 151a-d, may be movable by a drive unit (see Figures 5 and 6). Having a drive unit makes it possible to place the discharge device 150 or parts of the discharge device 150 in different operating states to perform different tasks, e.g. a first state for dispensing a coating substance onto the yarn and a second state for performing a cleaning session or other maintenance or idling.

[0049] Downstream of the discharge device 150, another yarn guiding device 160 is provided. The second yarn guiding device 160 cooperates with the first yarn guiding device 140 to ensure that the yarn 20 is correctly positioned during its movement along the discharge device 150. The second yarn guiding device 160 may, for example, be in the form of one or more guide rollers 162, 164, which may also be designed to induce a rotation of the yarn 20 along its longitudinal axis. This additional function may provide advantages in coloring, as will be explained below.

[0050] The system 10 may further include a yarn speed sensor (not shown) configured to measure the speed of the yarn 20 passing through the system 10 .

[0051] Additionally, an optical detection system (not shown) may be positioned downstream of the discharge device 150 along the direction of travel of the at least one yarn 20. The optical detection system is configured to illuminate the yarn 20 to receive light reflected from the yarn 20 when the yarn 20 is illuminated. Information gathered from the optical detection signals may be used, for example, to determine the position of the yarn relative to the nozzles 152a-f, the width of the yarn, and / or the characteristics of the yarn. This information may be used, for example, to detect nozzles in need of maintenance, the need to reposition the nozzles, and / or to detect variations in the coating material. Additionally or alternatively, the optical detection system may be used to determine different characteristics of yarns to which one or more coating materials have been applied.

[0052] The yarn 20 is then fed forward through one or more fixation units 170 that are provided to fix the treatment substance to the yarn 20. The fixation units 170 preferably comprise heating means, such as hot air supplying elements or heating elements, or UV light sources to cure or fix the treatment substance, e.g., coloring substance, to the yarn 20. As shown in Figure 2, the fixation units 170 can be positioned either horizontally, vertically, or at an angle between horizontal and vertical.

[0053] Before exiting the housing 105, the yarn 20 may pass through a cleaning unit 180, such as an ultrasonic bath, which removes unwanted particles from the yarn 20. Once the treatment substance is fixed to the yarn 20, the cleaning unit 180 leaves the treatment substance unaffected.

[0054] The processing unit 100 may further comprise a lubrication unit 185 disposed inside the housing 105. Additional yarn buffers and yarn feeders (not shown) may also be included in the processing unit 100, located at various positions in the yarn path.

[0055] The thread 20 preferably exits the processing unit 100 through an opening or the like, which routes the thread 20 to an associated thread consuming device, such as an embroidery machine 15, as shown in Figures 1a and 1b.

[0056] The thread feeder 130 and other components that engage the thread 20 during operation are preferably configured so that the force required to pull the thread 20 from the processing unit 100, i.e., the pulling force applied by the downstream embroidery machine 15, is approximately the same as if the processing unit 100 were replaced with a prior art thread reel.

[0057] A control unit 190 with associated electronics such as power electronics, communication modules, memory, etc. is also provided. The control unit 190 is connected to the yarn feeder 130, the discharge device 150, and the fixing unit 170, allowing for control of the operation of these components. Furthermore, the control unit 190 is configured to control the operation of the entire processing unit 100, including the cleaning unit 180, the lubrication unit 185, the splitting of the yarn 20, the yarn speed at various positions along the processing unit 100, the yarn buffer, etc. The control unit 190 may also be configured to receive control signals from one or more components of the processing unit 100, e.g., control signals for triggering certain controls, or other information related to, e.g., yarn consumption by the embroidery machine 15.

[0058] The control unit 190 may be implemented by any commercially available CPU ("Central Processing Unit"), DSP ("Digital Signal Processor") or any other electronic programmable logic device, or a combination of such processors or other electronic programmable logic devices. The control unit 190 may be implemented using instructions enabling the hardware functions, for example, by using computer program instructions executable on a general-purpose or special-purpose processor, which may be stored on a computer-readable storage medium 192 (disk, memory, etc.) that is executed by such a processor. The storage medium 192 is preferably in operative communication with the control unit 190.

[0059] In one embodiment, a user interface is also provided via a display 195, preferably located at the front end of the housing 105. The display 195 allows a user to interact with the control unit 190 and is therefore connected thereto, so that control parameters of the yarn feeder 130, discharge device 150, fixation unit 170 etc. can be set depending on the process specifications. The display 195 may also preferably be used to alert the user of critical situations, whereby the display 195 may be used by the control unit 190 to issue alarms etc.

[0060] It should be noted that the above components may not necessarily be included in a stand-alone processing unit 100, but instead the components of the processing unit 100 may be separated into several units, at least one of which is a stand-alone unit. Preferably, a stand-alone unit includes at least one ejection device 150.

[0061] FIG 3 shows the discharge device 150 which, as described above, forms part of the processing unit 100. The direction of movement of the yarn 20 during use is indicated by solid arrows in FIG 3. As will be explained in more detail shortly, the discharge device 150 comprises a number of nozzles 152a-f arranged at different longitudinal positions (e.g. spaced a distance d1 apart) along the yarn 20 which passes through the processing unit 100 during use.

[0062] Each nozzle 152a-f is positioned to dispense a coating substance, such as ink, onto yarn 20 when the nozzle is actuated. The coating substance is absorbed by yarn 20, for example, at different circumferential positions of yarn 20, as yarn 20 twists about its longitudinal axis. The relative positions of two adjacently dispensed droplets of coating substance can be selected such that the droplets overlap.

[0063] The processing unit 100 comprises one or more ejection devices 150. Each ejection device 150 is preferably formed as a series of inkjet printheads 151a-d, each printhead 151a-d having one or more nozzle arrays. Each nozzle array typically comprises hundreds or thousands of nozzles. For illustrative purposes, only six nozzles 152a-f are shown for one printhead 151a-d. However, it should be understood that each nozzle array may comprise several thousand nozzles 152 each. By way of example, each printhead 151a-d may be associated with a single color. In the example shown, the ejection device 150 has four printheads 151a-d, each printhead 151a-d being associated with a particular color according to the CMYK standard. However, other coloration models may also be used.

[0064] The exact configuration of the processing unit 100 may vary. For example, the processing unit 100 may comprise a single ejection device 150 having multiple printheads 151a-d, each of which in turn comprises multiple nozzles 152a-f.

[0065] In another embodiment, the processing unit 100 comprises several discharge devices 150 arranged either in series or in parallel. Each discharge device 150 then comprises several printheads 151a-d. When arranged in series, the upstream discharge device 150 may have printheads 151a-d associated with one or more colors of a particular color standard, while the downstream discharge device 150 has printheads 151a-d associated with other colors of the same color standard. When arranged in parallel, each discharge device 150 may have printheads 151a-d associated with all colors of a particular color standard, but associated with different yarns 20. In such an embodiment, two separate yarns 20 can be treated simultaneously and in parallel. Of course, combinations of parallel / series configurations are also possible.

[0066] In yet another embodiment, the discharge device 150 has only a single print head 151a-d. In that case, dynamic coloring of the yarn 20 would require several discharge devices 150 of the processing unit 100.

[0067] Each nozzle 152a-f is capable of dispensing a coating substance having a color according to the CMYK color model, in which the primary colors are cyan, magenta, yellow, and black. It may therefore be possible to dispense a wide variety of colors onto the yarn by activating the nozzles 152a-f, such that the total colorant of a particular length of yarn 20 is a mixture of the colorants dispensed by the nozzles 152a-f. As explained above, this is preferably achieved by arranging several printheads 151a-d in series, whereby the nozzles 152a-f of a particular printhead 151a-d are dedicated to a single color.

[0068] In another embodiment, each nozzle 152a-f dispenses a coating material having a color that includes a mixture of two or more primary colors of the CMYK color model.

[0069] The control unit 190 is configured to control the operation of the nozzles 152a-f such that the coating substance is discharged onto the thread 20 as it passes through the processing unit 100, and in particular as it passes through the discharge device 150. Such an arrangement allows for very precise coloring of the thread 20, and the coloring provided by the processing unit 100 can provide, for example, highly visually sophisticated embroidery patterns.

[0070] For coloring operations, the control unit 190 receives one or more input signals specifying the desired color and / or coloring effect. The color input preferably includes information regarding the exact color and the longitudinal start and stop positions of the yarn 20 of that particular color. If the yarn speed is determined, the longitudinal start and stop positions can be expressed in terms of specific time values.

[0071] 4a-b show a top view of each of the print heads 151a. The print head 151a has a plane in which the nozzles 152 are arranged. As mentioned above, the total number of nozzles 152 of a single print head can be up to several thousand when provided on a print head 151a with a size of a few centimeters. In the example shown, a much smaller number of nozzles 152 is shown. The nozzles 152 can be distributed in one or more nozzle arrays 153. In FIG. 4a, the nozzles 152 are distributed in two parallel arrays 153. The arrays 153 are aligned with each other such that the nozzles 152 of one array 153 are arranged adjacent to the nozzles 152 of the other array 153.

[0072] FIG. 4b shows a similar example, but with a vertical offset between the two arrays 153.

[0073] In an exemplary embodiment, the system 10 includes an ejection device 150 having four different color devices and is connected to a thread consuming device 15, such as an embroidery machine. In this embodiment, green is mixed as a combination of cyan and yellow, while black and magenta are not currently being used. Green is scheduled to be used at 8000 stitches, and after the green sequence, the system switches to coloring the thread brown. Thus, in this example, black and magenta will not be used for 10 minutes if the system 10 is running at a speed of 800 RPM.

[0074] It is undesirable to stop the embroidery machine 15 to perform a cleaning routine on the nozzles 152a-f, as this would typically require an operator to manually start the embroidery machine 15, which would have a negative impact on productivity. Therefore, it is desirable to perform the necessary maintenance on colors that are not currently being used so that they will be available for use as soon as their turn comes.

[0075] The inventors of the present invention, after some insightful reasoning, have realised that it would be beneficial to be able to perform maintenance of one or more discharge devices 150 and / or one or more printheads 151a-d without stopping the yarn consumption of the yarn consuming device 15. For example, by knowing a given pattern to be created on a substrate, it is possible to estimate the time when one or more nozzles 152a-f will be used or not. This information can then be used to perform maintenance of nozzles that are not currently being used and are not scheduled to be used in a given time interval.

[0076] The frequency with which a nozzle requires maintenance depends on several factors. Maintenance can depend, for example, on the time the nozzle is exposed to air, whether the nozzle that dispenses the coating material is activated or not, the frequency of dispensing, the temperature and / or humidity. In most cases, the most important factor is the time the nozzle is exposed to air, i.e., the time the nozzle can be exposed to air without drying out (partially or completely), which is related to the frequency of dispensing.

[0077] (Decision on maintenance) Therefore, it is beneficial to have a system 10 configured to determine whether a maintenance sequence should be performed on at least the first printhead 151a, and to perform said maintenance without stopping the thread consumption of the thread consuming device 15. The maintenance sequence should be performed when one or more printheads 151a-d require maintenance and / or when it is an appropriate time to perform maintenance on one or more printheads 151a-d.

[0078] The control unit 190 may determine whether a maintenance sequence should be performed based on one or more factors, as seen in Fig. 5a. Such factors may be the predefined pattern 70 to be created on the substrate, the current operating speed 50 of the yarn consuming device 15, the estimated consumption of coating substance 80, the estimated current yarn consumption 60, the estimated future yarn consumption 60, and / or a time interval. The following factors will now be described in more detail.

[0079] The control unit 190 may be further configured to receive a predetermined pattern to be created on the substrate. The predetermined pattern may include information regarding the number of stitches, stitch length, stitch pattern, color scheme of the pattern, etc.

[0080] The control unit 190 may further be configured to analyze the current operating speed (eg, RPM) of the yarn consuming unit 15 .

[0081] The control unit 190 may be further configured to analyze the estimated consumption of the coating substance.

[0082] The control unit 190 may further be configured to analyze current and / or upcoming thread consumption to determine when a next event occurs. The event may be, for example, a color change. The thread consumption may be based on the operational data and at least one parameter related to one or more thread consumption parameters. In one embodiment, the control unit 190 is configured to use at least one parameter related to one or more thread consumption parameters to evaluate the thread consumption. The thread consumption parameters include material-related parameters or stitch-related parameters. The substrate parameters may be related to different parameters of the substrate, for example. For example, the substrate parameters may be related to a thickness of the substrate, an elasticity of the substrate, and / or a placement of the substrate within the thread consuming device 15, or any combination thereof. The stitch parameters may be related to a tension of the substrate 20, an angle at which the substrate 20 is applied to the substrate, an angle of at least the last stitch, a feature related to the underlying stitch, or any combination thereof.

[0083] The method for assessing current and / or future yarn consumption will now be described in more detail with reference to Fig. 5b. The control unit 190 is configured to receive or generate 310 operational data and to receive or generate 320 at least one parameter related to the one or more yarn consumption parameters 40. Based on the operational data and the at least one parameter related to the one or more yarn consumption parameters 40, the control unit 190 is configured to assess 330 the yarn consumption of the yarn consuming device 15.

[0084] The control unit 190 may be further configured to perform 340 a simulation of yarn consumption and to evaluate the yarn consumption using the simulation data in order to improve the accuracy of the operational data and / or one or more yarn consumptions and / or to improve the accuracy of the evaluation of the yarn consumption.

[0085] In one embodiment, the control unit 190 is further configured to use 350 the stored data to further refine the accuracy of the simulation data and / or to further refine the accuracy of the operational data and / or one or more yarn consumption parameters.

[0086] In one embodiment, the control unit 190 is configured to determine whether to perform a maintenance sequence based on the current operating speed and a predefined pattern to be created on the substrate. In a preferred embodiment, the determination is also based on the current and / or future yarn consumption of the yarn consuming device 15. However, any combination of different factors may be used to determine whether to perform a maintenance sequence.

[0087] The control unit 190 may further be configured to determine whether a maintenance sequence should be performed based on a material cue. The material cue, which may for example be a color cue, is activated and includes an upcoming material to be applied to the at least one yarn 20. Based on the material cue, it is possible to schedule maintenance at the most appropriate opportunity possible.

[0088] The control unit 190 may be further configured to modify the number of active nozzles 152a-f based on the operation of the yarn consuming device 15 and / or the operation of the processing unit 100. Due to slower operating speeds and lighter color creation, using fewer nozzles may be preferable. Dispensing coating material less frequently results in longer periods of time when nozzles are not in use, increasing the need for maintenance. Dispensing coating material more frequently therefore requires less maintenance (and more specifically, less spitting, as will be explained in more detail below). In one exemplary embodiment, when the operating speed drops below a threshold, the number of nozzles is reduced from 236 to 96.

[0089] In one embodiment, control unit 190 is configured to determine whether there are suitable time slots in the color queue so that a maintenance sequence can be performed on one or more nozzles.

[0090] The control unit 190 is configured to determine whether there is a time slot large enough to allow the desired maintenance sequence to be performed. Additionally or alternatively, the control unit 190 is configured to determine whether there is a time slot long enough to allow the nozzles (and their printhead) to be placed in a capping position (i.e., a position in which the nozzles are not dispensing coating and are placed in a position sealed off from contaminants and drying, as described in more detail below). The nozzles can be placed in a maintenance sequence before or after being placed in the capping position.

[0091] When the system 10 identifies that a maintenance sequence is to be performed on one or more printheads 151a-d, the system schedules such a sequence and then initiates the sequence either directly or after the nozzles are placed in a capping position.

[0092] (separate movements) In a system including at least two ejection devices 150, system 10 may be configured to control movement of the individual ejection devices 150 such that one or more of the ejection devices 150 are placed in a maintenance position. A system 10 including at least two printheads 151a-d may additionally or alternatively be configured to control movement of the individual printheads 151a-d such that one or more of the printheads 151a-d are placed in a maintenance position.

[0093] 6 shows a part of a processing unit 100 having three printheads 151a-c movably arranged between an operating position (first position) and a maintenance position (second position). In this example, movement, and therefore maintenance, is performed on at least one of the printheads 151a-c. However, the following description also applies to the situation in which the entire discharge device is moved.

[0094] In one embodiment, the system 10 is configured to move one print head 151c between a first position and a second position. The first position 41 can be one or more operating positions where the discharge device 150 is configured to dispense one or more coating substances onto at least one yarn 20. In one embodiment, this position corresponds to when the nozzles 152a-f are aligned over at least one yarn 20.

[0095] The second position 42 may be one or more positions where the discharge device 150 is configured to no longer dispense one or more coating substances onto the at least one yarn 20. This position 42 is therefore used during maintenance (cleaning, servicing, etc.).

[0096] When the system 10 identifies that a maintenance sequence should be performed on one or more printheads 151a-d, the system initiates said sequence by moving the printhead 151c to be cleaned to a second position. This movement is preferably performed by the drive unit 32, as will be explained in more detail with reference to FIG. 6. While the printhead 151c is in the second position, a maintenance sequence is performed on said printhead. During the maintenance sequence, the printhead 151c moved to the second position is deactivated with respect to dispensing coating substance onto the at least one yarn 20. The deactivation is preferably performed as soon as the printhead 151c moves from the operating position towards the second position.

[0097] Printheads 151a-c are movable relative to one another so that, to perform maintenance, one or more printheads 151c may be positioned at a second position and one or more printheads 151a-b may be positioned at a first position to dispense one or more coating substances onto yarn 20. Once a maintenance sequence has been performed on printhead 151c, printhead 151c is returned to the first position.

[0098] In one embodiment, if the print heads 151a-d comprise more than one nozzle array 153, the control unit 190 is configured to change the active nozzle array 153 of the print heads 151a-d. Thus, if the control unit 190 determines that a nozzle array 153 requires maintenance, it moves the print head so that said nozzle array 153 can be cleaned, while other nozzle rows of the same print heads 151a-d are active. Thus, the nozzle array 153 of the print heads 151a-d can be cleaned while another nozzle array 153 of the same print heads 151a-d is dispensing a coating substance to one or more threads. Thus, the print heads 151a-d may comprise active and passive nozzle arrays 153, where a maintenance sequence is performed on the passive nozzle array, which is in an operative position and dispenses the coating substance. In one embodiment, the maintenance sequence includes a spit step, in which the nozzles 152a-f are forced to dispense the substance for short time intervals. Because the dispensing process does not require any other components, it can be performed in a very quick and efficient process, which is beneficial since this is the type of maintenance most frequently required for the dispensing system 10.

[0099] It should be noted that one or more printheads can be in an operating position while one or more printheads are parked in a capped position, such as an intermediate position where no maintenance sequence is performed.

[0100] (Drive unit) Movement of the print heads 151a-c can be achieved by a drive unit 32, as already briefly described above. An example embodiment of the drive unit 32 is shown in Figure 7. However, other types of drive units are possible. For example, the drive unit can be a structure comprising a thread rod arranged with a nut or ball screw configured to move the print heads between a first position and a second position.

[0101] Turning now to Fig. 7, which shows an exemplary embodiment of the drive unit 32 of the processing unit 100. The drive unit 32 is configured to move the discharge device 150 and its associated print heads 151a-d between a first position 41 and a second position 42 relative to the at least one yarn 20. This movement is preferably along a movement axis of the drive unit 32. This can be performed by a mechanism 40, also called transmission 40, which has different transmission ratios during the movement from the first position 41 towards the second position 42.

[0102] As can be seen in FIG. 6, the drive unit 32 is connected to the ejection device 150, e.g., to the print heads 151a-d, by the actuator 34 and the crank 37. Together, the actuator 34 and the crank 37 form the transmission mechanism 40. The crank 37 is in the form of a lever arm, one end of which is connected to the rotation axis R1 of the electric motor 36 of the drive unit 32, and the other end of which is pivotally connected to the actuator 34 at the rotation axis R2. The actuator 34 has an opposite end, which is in turn pivotally connected to the ejection device 150 at the rotation axis R3. In the embodiment shown in FIG. 5, the transmission ratio can be seen as the correlation between the rotational movement of the crank 37 or the electric motor 36 of the drive unit 32, and the linear movement of the ejection device 150. The transmission ratio is the ratio of the input rotation to the output linear translation of the ejection device 150. Thus, a low transmission ratio means that a certain rotational movement input from the drive unit 32 or the crank 37 results in a small linear movement of the ejection device 150, and vice versa for a high transmission ratio.

[0103] The actuator 34 connects the crank 37 of the motor 36 to the discharge device 150. The actuator 34 may comprise a connecting rod having a curved portion 34a and a straight portion 34b. The curved portion 34a connects to the crank 37 and the straight portion 34b connects to the discharge device 150. The transmission 40 is configured to convert the rotational movement of the crank 37 into a linear movement of the discharge device 150. The actuator 34 is designed such that the transmission ratio during the movement between the idle position 41 and the working position 42 is lower near the end position than between these positions. This is advantageous for a very precise movement, thus allowing a high precision of the movement when aligning the discharge device 150 to the yarn 20. This allows for an improved resolution of the movement.

[0104] The motor 36 may be, for example, a step motor or a DC motor. In an embodiment in which the motor 36 is a DC motor, it may be advantageous if the drive unit 32 further comprises a position sensor 38. The position sensor 38 is configured to determine a position of the drive unit 32. The position sensor 38 is preferably in communication with the control unit 190. Regardless of the type of motor 36 used, the position sensor 38 may be configured to determine the position of the drive unit 32 to improve the accuracy of the system 10, in particular to determine the position of the ejection device 150. For example, a particular angular position of the motor may be correlated with a particular linear position of the ejection device 150.

[0105] The components to be moved, i.e. print heads 151a-d, are preferably movable along a movement axis perpendicular to the movement of the thread 20. To guide this movement, the drive unit 32 may further comprise a guide member 39. The guide member 39 may for example be a guide rail or a groove. The first position 41 and / or the second position 42 may be arranged at the extreme ends of the movement axis A.

[0106] Further, in one embodiment, the multiple drive units 32 share a common motor 36. This is shown in FIG. 8. The motor 36 can be of the same type as described above. The single motor 36 is configured to control the operation of the multiple drive units 32. By using only one motor, it is possible to perform maintenance of one or more heads synchronously. In one embodiment, the maintenance is designed such that maintenance routines can be performed on one or more printheads at the same time. Any combination of printheads is possible. In one embodiment, one motor is used to control two drive units (and therefore two printheads 151a-d).

[0107] (Maintenance sequence) A maintenance sequence may include several steps and processes, and the following description of a maintenance sequence should not be considered limiting, but merely a few examples, since different types of maintenance steps are known to those skilled in the art. A cleaning cycle may include, for example, one or more of spitting, purging, air ejection, wiping, and the like. In one exemplary sequence, the steps include driving to home mode, capping, opening the vent valve, aspirating ink from the nozzles, closing the vent valve, aspirating ink from the capping, pumping ink with the ink supply pump, wiping, aspirating ink from the capping, wiping, spitting, and finally aspirating ink from the capping. It should be noted that the sequence performed may be predetermined or may be changed depending on how the previous step or set of steps in the sequence has progressed. Furthermore, the time between each action may be fixed or may be changed during the process.

[0108] The buffer system (described below) or any similar system providing a buffering effect is filled with an appropriate amount of treated yarn, which allows the yarn to be stopped and the discharge device 150 (or a part thereof) to stop dispensing the coating.

[0109] Once cleaning and / or servicing of a printhead is decided and the thread stops, the printhead moves to a maintenance or capping position. The capping position consists of a capping system that seals the nozzles from contaminants and drying. The capping system may further comprise a pump unit that draws a vacuum on the printhead. When a printhead is moving towards the capping position, its vaults can open the caps belonging to that head. Only the vaults of the printheads selected for the maintenance routine are opened. Thus, the vaults belonging to the heads that are in the printing, operating position remain closed. This prevents air leaks and ensures that all heads included in the current maintenance routine are properly cleaned. The same motors as above, or dedicated actuators, are used to open the vaults for cleaning one or more printheads.

[0110] The maintenance sequence may include one or more cleaning steps. The maintenance sequence may include a spitting step in which the nozzles 152a-f are forced to dispense a substance at short time intervals. Thus, during spitting, a few drops of coating substance, such as ink, are dispensed through each of the nozzles in question. This activates the nozzles 152a-f and thus prevents them from drying out, clogging, jetting, and / or dispensing the coating at an undesirable angle due to lack of cleaning.

[0111] Additionally or alternatively, the maintenance sequence includes a wiping step. The wiping step may comprise a wiper that wipes the surface of the printhead to remove ink residue and dust or other debris that has collected on the printhead. The wiper may be an elastomeric material, such as nitrile rubber, ethylene polypropylene diene monomer (EPDM) elastomer, or other types of rubber-like materials known to those skilled in the art. The wiping action is typically accomplished by moving the printhead across the wiper, or by moving the wiper across a stationary printhead. The same motor as above, or a dedicated motor, is used to move the wiper to clean one or more printheads.

[0112] (Buffer System) System 10 may further include a buffer system, which may be used in conjunction with the decision steps when performing maintenance sequences and / or in conjunction with the movement of the individual printheads and / or ejection devices 15. However, the buffer system may also be used in conjunction with system 10 where these features are not present.

[0113] The buffer system comprises at least one thread buffer unit. The thread buffer unit may be in the form of a buffer arm having one end along which the thread is guided. The opposite end may be pivotally mounted on a support so that the position of the thread guiding end can be adjusted. The force applied to the buffer arm consequently determines the tension in the thread.

[0114] The yarn buffer unit allows the coated yarn to be buffered under tension. The force applied to the yarn by the yarn buffer unit determines the tension of the yarn, which in most cases varies along the yarn path. Thus, the exact structure of the yarn buffer may provide different tensions at different positions along the yarn. In an alternative embodiment, the yarn buffer unit is constructed such that the force applied to the yarn is determined by gravity, a spring, a combination of gravity and a spring, or any other device capable of controlling the yarn tension. The yarn tension is controlled by adjusting the force in the yarn buffer unit that pulls the yarn through the processing unit, as described above.

[0115] The thread buffer unit is preferably arranged downstream of at least one discharge device 150. In one embodiment, the buffer is filled just before the cleaning or maintenance process starts, after which the thread is stopped by the thread feeder 130. Furthermore, in one embodiment, the thread buffer strives to be fully filled at all times. The thread feeder 130 is preferably arranged upstream of the discharge device 150. Thus, it stops the thread arranged in conjunction with the discharge device 150. While the thread is stopped, the discharge device 150, or one or more of its print heads 151a-d, is cleaned. During this cleaning process, the thread consuming device 15 uses the thread from the buffer when the thread is stationary. When the cleaning process is finished, the thread starts moving again.

[0116] The amount of yarn in the buffer may be adjusted based on the expected yarn consumption during a planned cleaning process, which may preferably take into account increases in the speed of the system 10.

[0117] Although the present invention has been described primarily with reference to a system comprising one processing unit 100 and one yarn consuming device 15, it should be understood by those skilled in the art that the features of the present invention are also applicable to other systems. Figures 8a-b show two examples of such alternative systems.

[0118] In Fig. 8a, the system 10 comprises a first and a second processing unit 100a, 100b and a first and a second yarn consuming device 15a-b. Each processing unit 100a, 100b controls and executes operations on each yarn consuming device 15a-b. It should be noted that the first and the second processing units 100a may be separate but share one or more components. In one embodiment, the control unit 190 is arranged as a separate unit from the first and the second processing units 100a, 100b, such that one control unit 190 is configured to control the operation of both processing units 100a, 100b and correspondingly both yarn consuming devices 15a-b.

[0119] In Fig. 8b, the system 10 comprises one processing unit 100a and a first and a second yarn consuming device 15a-b. In this embodiment, the one processing unit 100a is configured to control and execute the operation of the two yarn consuming devices 15a-b.

[0120] It should be noted that although FIG. 8a shows only two processing units and two yarn consuming devices, and FIG. 8b shows only one processing unit and two yarn consuming devices, it should be understood that any reasonable number of processing units and / or yarn consuming devices may be present in the system 10.

[0121] In addition or as an alternative to having a buffer system, the system 10 can include a duplicate set of printheads (and possibly a duplicate set of ejection devices 150). By having a duplicate set of printheads, the system 10 can alternate between the two sets. This can eliminate the need for a buffer, since the yarn 20 never needs to be stationary. Thus, the control unit 190 is arranged to switch between the operation of the two sets of printheads. When it determines that a maintenance sequence should be performed on at least one printhead of the first set, the control unit 190 is configured to switch to perform the maintenance sequence on that printhead, and possibly all printheads of the first set, while activating the second set of printheads to dispense a coating on the yarn 20. Although the present invention has been described above with reference to certain embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the present invention is limited only by the scope of the appended claims.

[0122] In the claims, the term "comprises / comprising" does not exclude the presence of other elements or steps. Moreover, although individual features may be included in different claims, these may possibly be combined advantageously and their inclusion in different claims does not imply that a combination of features is not feasible and / or advantageous. Moreover, a singular reference does not exclude a plurality. The terms "a", "an", "first", "second", etc. do not exclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be interpreted as limiting the scope of the claims in any way.

Claims

1. A system (10) for in-line processing of a yarn (20) for use with a yarn consuming device (15), comprising: a processing unit (100) comprising at least first and second printheads (151a, 151b), each configured to dispense one or more coating substances onto at least one yarn (20) upon actuation; a control unit (190) configured to determine whether a maintenance sequence should be performed on at least the first printhead (151 a) and, if so, to schedule the maintenance sequence on at least the first printhead (151 a); A system (10) comprising:

2. The control unit (190) receiving a current operating speed of the yarn consuming device (15); determining whether to perform a maintenance sequence based at least on the current operating speed; The system (10) of claim 1, comprising:

3. The control unit (190) receiving a yarn consumption of the yarn consuming device (15); determining whether to perform a maintenance sequence based at least on said yarn consumption; The system (10) of claim 1 or 2 further comprising:

4. 4. The system of claim 1, wherein the control unit is further configured to control one or more printheads placed in an operational mode at the same time that one or more printheads are placed in a maintenance mode.

5. The system (10) of any one of claims 1 to 4, wherein the control unit (190) is further configured to determine whether a maintenance sequence should be performed based on at least a predetermined operating pattern.

6. The system (10) of any one of claims 1 to 5, wherein the control unit (190) is further configured to determine whether a maintenance sequence should be performed based on at least an estimated consumption of coating substance.

7. The system (10) of any one of claims 1 to 6, wherein the control unit (190) is further configured to determine a time interval for the maintenance and to determine whether a maintenance sequence should be performed based on at least the time interval.

8. The system (10) according to any one of the preceding claims, wherein the maintenance sequence is performed without stopping the yarn consumption of the yarn consuming device (15).

9. 9. The system (10) of any one of claims 1 to 8, wherein the control unit (190) is configured to perform a maintenance sequence of at least the first print head (151 a) by moving the first print head (151 a) from a first position (41) to a second position (42), thereby deactivating the first print head (151 a) from dispensing coating substance onto at least one yarn (20).

10. 10. The system (10) of claim 9, wherein at least the second printhead (151b) is disposed at the first location (41) and the first printhead (151a) is disposed at the second location (42).

11. The system (10) of claim 9 or 10, wherein the first position (41) is an operating position and the second position (42) is a maintenance position.

12. 12. The system (10) of any one of claims 1 to 11, wherein each print head (151a-d) comprises a plurality of nozzles (152a-f) arranged at different positions relative to at least one yarn (20), the at least one yarn (20) being in motion during use, and each nozzle (152a-f) is configured, upon actuation, to dispense one or more coating substances onto the at least one yarn.

13. The system (10) of claim 12, wherein the control unit (190) is further configured to vary a number of active nozzles (152a-f) based on a current required flow rate of the one or more coating substances.

14. The system (10) of claim 12 or 13, wherein the control unit (190) is further configured to vary a number of active nozzles (152a-f) based on a desired visual appearance of the yarn (20).

15. The system (10) of any one of claims 12 to 14, wherein the nozzles (152a-f) are inkjet nozzles.

16. The system (10) according to any one of the preceding claims, further comprising a thread consuming device (15).

17. 17. The system (10) of claim 16, wherein the thread consuming device (15) is an embroidery machine, a sewing machine, a knitting machine, a weaving machine, a tufting machine, a thread winding machine, or any combination thereof.

18. The system (10) according to any one of the preceding claims, further comprising a thread buffer system arranged downstream of the at least two printheads (151a-d).

19. 20. The system (10) of claim 18, wherein the control unit (190) is further configured to fill the thread buffer system when it determines that a maintenance sequence should be performed.

20. 20. The system (10) of claim 18 or 19, further comprising a thread feeder (130) arranged upstream of the print heads (151a-d), and wherein the control unit (190) is configured to stop the thread feeder (130) when the control unit determines that the maintenance sequence should be performed.

21. The system (10) according to any one of claims 18 to 20, wherein during the maintenance sequence, the thread consuming device (15) consumes thread (20) from the buffer.

22. A method for in-line treatment of at least one yarn (20), comprising: providing a processing unit (100) comprising at least first and second print heads (151 a, 151 b), each configured to dispense one or more coating substances onto at least one yarn (20) upon actuation; providing a control unit (190) configured to determine whether a maintenance sequence should be performed on at least the first printhead (151 a) and, if so, to schedule the maintenance sequence on at least the first printhead (151 a); A method comprising:

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