Method for automatically adjusting the draft in a textile machine
Patent Information
- Application Number
- PCT/EP2026/058336
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-24
- Filing Date
- 2026-03-24
- Publication Date
- 2026-10-01
Smart Images
Figure EP2026058336_01102026_PF_FP_ABST
Abstract
Description
[0001] Internal file number P249904WO1 2026002472 / 24.03.2026
[0002] Title: Method for automatic warpage adjustment in a textile machine
[0003] Description
[0004] The present invention relates to a method for automatic distortion adjustment in a textile machine, in particular a combing machine or a controlled section, such as a pre-drawing unit, with a motor-adjustable drafting unit for drawing pre-prepared fiber strips and a control system, comprising the steps of: providing an operating speed of a main drive motor of the textile machine for productive operation of the textile machine; operating the textile machine in productive operation with an actual speed of the main drive motor corresponding to the operating speed and with an actual distortion of the drafting unit corresponding to a target distortion of the drafting unit specified by the control system, wherein the drawn fiber strips are combined into a single fiber strip in a nonwoven guide downstream of the drafting unit and optionally subsequent strip forming units and deposited in a can.Furthermore, the present invention relates to a combing machine and a pre-stretching machine.
[0005] Currently, combing machines with a uniform eight combing heads are used in spinning preparation. The fibers to be combed are fed to these machines as cotton rolls approximately 30 cm wide. The productivity of the combing machine thus depends almost exclusively on the number of comb strokes achieved, which ranges from 350 to 550 comb strokes per minute in continuous operation. Increasing productivity in the combing process is therefore only possible with additional machines. Increasing the number of combing machines also necessitates a proportional increase in the number of winding machines, with approximately five combing machines currently being fed by one winding machine. This entails significant space and investment requirements. The next generation of combing machines will feature 10, 12, or 16 combing heads, thereby increasing productivity without increasing the number of comb strokes.
[0006] To integrate this new generation of combing machines into an existing spinning mill preparation system, the fiber slivers deposited in the can must still have a mass of approximately 5 to 10 ktex so that the subsequent machines can continue to operate with only minor adjustments. Due to the increased number of combing heads, the fiber sliver mass at the drafting unit before the can deposit increases by 25 to 100%, necessitating a higher draft rate. Simultaneously, the speed of the exiting fiber sliver deposited in the can increases. Internal reference P249904WO1 2026002472 / 24.03.2026
[0007] To this end, EP 3850131 B1 proposes various measures for adjusting the drafting process and modifying the drawing unit in order to continue delivering a fiber strip with a strip density of 5 to 10 ktex for a subsequent machine. Subsequently, the more than eight fiber strips are fed into a drawing unit that has a working width of more than 180 mm, preferably at least 200 mm, at the clamping line in the entry of the main drafting unit.
[0008] The increased number of fiber strands with an unchanged winding pattern per comb head increases the necessary draft in the drafting unit, resulting in a higher degree of parallel alignment of the fiber strands in the combing process. This leads to reduced strand adhesion, which can cause the fiber strands to tear in the subsequent process. This can be compensated for by a higher fiber impact velocity in the web guide during strand formation, achieved through the higher delivery speed of a 12-head combing machine (also called a 12-head combing machine) with the same number of comb passes.
[0009] The drafting unit of a textile machine, in particular a drafting or combing machine, serves in the prior art to actively compensate for process- and material-related thick spots in the fiber sliver. Such thick spots arise, among other things, from random fluctuations in the fiber mass distribution in the carding or combing process, and from variations in fiber length.
[0010] Fiber-fiber and fiber-metal friction, uncontrolled fiber movement, and systematic influences such as piecing or geometric-mechanical effects at the roller pairs all contribute to sliver inconsistencies. These deviations lead to locally increased sliver mass and are cited in the literature as a major cause of sliver irregularities, which would propagate into the yarn quality without correction. To compensate for these thick spots, the textile machine combines several pre-prepared fiber slivers before the drafting unit, thereby reducing random mass fluctuations through averaging (doubling effect). Furthermore, drafting in the drafting unit, similar to a 4-over-3 system, actively smooths the sliver mass by parallelizing fibers and eliminating local thick spots. Control systems additionally monitor mass fluctuations in real time and dynamically adjust the draft to compensate for remaining local and short-wave thick spots during operation.From DE 102022116504 A, a regulating line is known in which a motor-adjustable drafting unit with several roller combinations is provided. A main motor drives the drafting unit at a constant main speed, while a control motor superimposes the speed of another roller combination to adjust the draft. The control system enables the drafting of pre-loaded fiber strips and the guiding of the sliver through downstream unit(s) to the can discharge point. Further methods for regulating drafting are known, for example, from EP 0692560 B1. Internal file number P249904WO1 2026002472 / 24.03.2026.
[0011] Drafting units in regulated sections or combing machines are the proven method for compensating for local thick spots. However, it has been shown that the adhesion of the laid fiber slivers is poor at low delivery speeds. The inventors noticed that when the machine stops, but also at very low delivery speeds of, for example, 150 meters per minute, the laid fiber slivers become unstable and tear easily. This is because the fibers are in a high degree of parallel alignment at low speeds. In this case, for example, in an eight-head combing machine (also called an 8-head combing machine) or a twelve-head combing machine, the consolidation achieved at high speed occurs when the fibers impact the web guide. This means that every machine stoppage of the combing machine becomes traceable in the fiber sliver, as the strength is reduced during slow operation.The fiber strip section attributable to the machine stoppage is significantly reduced. In the production line, this can lead to deteriorated running behavior, e.g., in the form of strip breaks or distortions, particularly in downstream machines, such as when the fiber strips are drawn into a (regulating) section.
[0012] The invention is based on the objective of providing a method for automatic distortion adjustment in a textile machine, which ensures that the produced or laid-down fiber tape maintains a consistent quality in tape adhesion even at low delivery speeds below 200 meters per minute and especially when the machine is stopped.
[0013] exhibits tape strength. Furthermore, it is an object of the invention to provide a combing machine or a line which, even at low delivery speeds below 200 meters per minute and especially during a machine stoppage, the produced or deposited fiber tape exhibits a consistent quality in tape adhesion or tape strength.
[0014] The solution is achieved by a method of the type mentioned above, in that the method further comprises: operating the textile machine in a special operation controlled by the control system, in which the actual speed is reduced to a target speed below the operating speed and the target delay is reduced depending on the actual speed and / or the target speed of the main drive motor.
[0015] The mass of the formed fiber sliver is selectively altered by changing the warpage in the drafting unit as soon as the speed of the main drive motor of the combing machine is outside its operating speed or within a range of a predetermined warpage adjustment. By increasing the mass of the sliver due to the controlled reduction of warpage in the drafting unit, the mass of the fiber sliver is locally increased. This increases the stability of the fiber sliver. This differs from typical local thickening in the fiber sliver, which is achieved through doubling and warpage adjustment by controlled [Internal File Number P249904WO1 2026002472 / 24.03.2026]
[0016] To compensate for the limitations of the drawing units, a section of the strip with increased mass is deliberately created by intentionally reducing distortion. Particularly good results have been achieved with section lengths of at least 50 centimeters up to several meters, for example, one, two, three, four, or five meters. It has been shown that this deliberately thickened strip section leads to fewer strip breaks during insertion in the machine following the textile machine, such as a regulating unit, and that the thickened strip section can be adjusted again during drawing in the regulating unit. As a result, the weak points in the fiber strip, which can sometimes be exacerbated by reducing the actual rotational speed to the point of the drawing unit or textile machine coming to a standstill (i.e., the main drive speed n = 0), are eliminated.
[0017] Delivery speeds that are zero, resulting from the absence or reduction of consolidation in the nonwoven guide, are compensated for or reduced by the production of a higher strip mass. The reduction in distortion in the drafting unit increases the number of fibers in the strip cross-section, thereby increasing strip adhesion, e.g., due to higher fiber-to-fiber friction.
[0018] The operating speed is defined as the determinable continuous rotational speed of the main drive of the textile machine at a set, planned production quantity or during productive operation. This speed can correspond, for example, to a target number of passes per hed of 300, 400, 500, or 600 nips / min, or a target delivery speed of 250, 300, 350, 400, 450, 500, 550, 600, etc., 1000, or more than 1000 m / min. The actual speed is the rotational speed of the main drive of the textile machine at a defined point in time. The target speed is a rotational speed of the main drive of the textile machine that differs from the actual speed and is to be achieved by changing the rotational speed of the main drive.
[0019] In one possible embodiment of the method, the control system can initiate a special operation when a start condition is met. This special operation thus differs from the regular production operation and can, for example, cover a can change, a malfunction, maintenance, etc.
[0020] The starting condition can be met, for example, when the actual speed falls below a predefined speed threshold or leaves a tolerance range around the operating speed. The starting condition can be the actual speed of the main drive falling below a defined speed threshold. The speed threshold can be defined by the lower limit of a tolerance range representing the range of speed fluctuations of the main drive during trouble-free production operation. The change in the drafting unit can be delayed if, for example, the production speed is already 10% or 20% below the operating speed. This reduces the length of the strip, which results in a higher internal file reference P249904WO1 2026002472 / 24.03.2026
[0021] The strip mass is affected. For this change in distortion, distortion adjustment ranges can be entered or stored in the control system, which delay the distortion change in the drawing unit when the rotational speed changes. For example, the tolerance range can be set directly below the productive speed, meaning the productive speed can form the upper limit of the tolerance range, and / or a lower limit of the tolerance range can be determined and stored in the control system, for example, by a fixed speed threshold or by a percentage value calculated from the productive speed (e.g., 95% of the productive speed, or 90%, 85%, 70%, etc.). Furthermore, the distortion reduction can be delayed after the start condition is met.The start condition and / or the dead time can be stored in a control unit and / or can be entered into the control unit by an operator.
[0022] Furthermore, the start condition can be met, for example, when the control system receives a stop signal. This can be triggered, for instance, by a malfunction, such as a manual intervention by the machine operator, a detected winder, a can change, etc.
[0023] In one possible embodiment of the method, the control system can initiate a controlled machine stop of the drafting unit, and in particular of the textile machine, during special operation. During this stop, the actual speed of the main drive motor is reduced along a predetermined target speed curve to speed n = 0, and the warpage is reduced during this speed reduction. The target speed curve can be a stop-target speed curve. Preferably, the minimum warpage of the drafting unit, and thus the maximum strip mass of the fiber strip, is reached before a machine stop at speed n = 0, i.e., standstill. For example, the warpage is reduced to a predetermined minimum warpage during the reduction of the actual speed and maintained as long as a non-zero actual speed, or n > 0, is present. It is understood that the warpage is only zero at speed n = 0, but is greater than zero at every other speed.at least corresponds to the minimum delay stored in the control system.
[0024] In one possible embodiment, upon receiving a start signal, the control system can initiate a controlled machine start of the drafting unit and, in particular, the combing machine. During this start, the actual speed of the main drive motor is increased along a predefined target speed curve to the operating speed. During this speed increase, the draft is increased until it reaches the target draft, in order to resume productive operation of the textile machine once the operating speed is reached. The target speed curve can be a start-up target speed curve. When the textile machine is ramped up to the operating speed, the same draft adjustment ranges can apply, in which the draft is increased again. Alternatively, it is also possible to use the ranges of the Internal File Number P249904WO1 2026002472 / 24.03.2026
[0025] The warpage adjustment for starting the textile machine up to operating speed and for slowing it down from operating speed must be designed differently. Thus, when the speed of the main drive motor is reduced if it deviates from the operating speed of the textile machine, or when the starting condition is met, the warpage in the drafting unit is reduced, increasing the mass of the fiber strip. Conversely, when starting the textile machine with an increase in the speed of the main drive motor, the warpage in the drafting unit is increased, decreasing the mass of the fiber strip. The process can be completed once the operating speed is reached again, i.e., when the textile machine is back in production operation.
[0026] Preferably, the adjustment or adaptation of the draft to the operating speed of the textile machine can be achieved via the machine's control system. With an optional measuring device for determining the strip mass, this system can simultaneously monitor the strip mass of the fiber strip before the can deposition and / or the strip mass of the fiber strips entering the drafting unit. For example, take-off rollers can be designed as measuring rollers with a sensor for detecting the strip mass, or the strip mass can be determined by a sensor in the nonwoven hopper or strip hopper. During production, the actual draft can thus be controlled to keep the strip mass at least largely constant. If the textile machine does not have strip mass control or if this control is deactivated, the actual draft during production can remain constant and correspond to the target draft.
[0027] The change, i.e., reduction or increase, of the warpage in the drafting unit can be linear, abrupt, or follow a curve stored in the textile machine's control system. These curves allow for consideration of the specific characteristics of the fiber quality being processed, the process conditions during strip production, and the subsequent yarn production.
[0028] In one possible embodiment, the distortion adjustment can be achieved by changing a preliminary distortion, a main distortion or both distortion zones in the drawing unit, wherein at least one of the distortion zones has an independently controllable control motor.
[0029] For example, the pre-drawing roller pairs can be driven by the main drive motor, and at least one pair of pre-drawing rollers can be driven by the control motor, which is independent of the main drive motor. By controlling the speed of the control motor, or, if the speed of the main drive motor changes, by controlling the speed of both motors, the control system can adjust the draft of the drawing unit. Other drive concepts that enable automatic draft adjustment in the drawing unit are also known and possible. Internal file number P249904WO1 2026002472 / 24.03.2026
[0030] In one possible embodiment, the change in distortion can be influenced by the climate in the combing mill and / or by the fibers being processed and / or by the stability of the fiber sliver on a subsequent machine, which in turn depends on the settings of the textile machine. For example, increasing humidity can increase sliver adhesion, so that the change in distortion can be reduced by changing the rotational speed.
[0031] An advantageous improvement to increase the stability of the fiber tape can be achieved by reducing the parallel alignment of the fibers in the tape through the introduction of compressed air in the nonwoven guide. The introduction of compressed air causes the fibers to swirl together, thereby disrupting their parallel alignment.
[0032] By introducing compressed air, a twist is created, at least on the surface of the fiber tape, thereby reducing the parallel alignment of the outer fibers on the tape's surface. This improves tape adhesion.
[0033] Preferably, the pressure of the introduced compressed air can be increased or decreased by changing the speed of the main drive motor of the textile machine. This provides a complement to the distortion adjustment, so that with a smaller change, the process of the downstream processing machines can run more stably with fewer adjustments to the control system.
[0034] Another advantageous embodiment for increasing the stability of the fiber tape can be achieved by deflecting the fibers of the tapes in the nonwoven guide using random layer elements. This also reduces the need to adjust the tape mass by changing the distortion. This technical solution can be used in addition to changing the tape mass and / or introducing compressed air laterally into the nonwoven guide.
[0035] Furthermore, the process may provide for the textile machine to be designed as a combing machine or as a drawing machine.
[0036] Another solution to the aforementioned problem is a combing machine, and yet another solution is a conveyor belt. The combing machine and conveyor belt according to the invention offer the same advantages as those described in connection with the method according to the invention, so reference is made here, for the sake of brevity, to the description above. It is understood that all the aforementioned embodiments of the method are transferable to the combing machine and the conveyor belt, and vice versa.
[0037] The combing machine has several combing heads, each combing head being designed by means of at least one winding or by means of at least one fiber strip made of cans. Internal file number P249904WO1 2026002472 / 24.03.2026
[0038] The combed fibers are fed into a separate fiber band for each combing head and transported to a discharge table. The individual fiber bands are fed to a drafting unit and, by means of a nonwoven guide, a subsequent nonwoven hopper, and a subsequent belt hopper, are drawn into a single fiber band and deposited in a can. In a first embodiment, the combing machine has a control system configured to control the drafting unit as a function of the rotational speed of the main drive motor of the combing machine by controlling at least one regulating motor of the drafting unit to increase or decrease its rotational speed.
[0039] The combing machine can have a measuring device in front of a can holder, designed to determine the mass of the fiber strip and send a measurement signal to the combing machine's control system. This allows the produced strip mass to be monitored online and the distortion in the drawing unit to be regulated depending on the speed of the combing machine.
[0040] Changes in warpage can be made depending on the running behavior of downstream machines. As soon as strip breaks occur at the creel of the downstream machine, the fiber strip exhibits insufficient strength, and the strip mass must be increased by reducing the warpage. As long as no production disruptions occur, the warpage can remain unchanged or be reduced only slightly. Monitoring the running behavior and implementing the change can be done manually by the machine operator or by networking the controls of the fiber strip-producing spinning preparation machines with the downstream textile machines.
[0041] Furthermore, a preliminary line is proposed to solve the problem, whereby the above description is equally applicable to the preliminary line and vice versa.
[0042] Further measures improving the invention are described in more detail below, together with a description of a preferred embodiment of the invention, with reference to the figures. The figures show:
[0043] Figure 1 shows a top view of a 12-head combing machine;
[0044] Figure 2 shows a perspective view of the components between the last drafting roller and the top of the can tray;
[0045] Figure 3 shows a flowchart of a process that can be carried out with the combing machine from Figure 1;
[0046] Figure 4 shows a diagram illustrating the progression of the delay adjustment to the rotational speed over time; Internal reference P249904WO1 2026002472 / 24.03.2026
[0047] Figure 5 shows another diagram with a preferred curve for the delay adjustment to the rotational speed over time;
[0048] Figure 6 shows an embodiment of a nonwoven guide;
[0049] Figure 7 shows another embodiment of the nonwoven guide; and
[0050] Figure 8 shows yet another embodiment of the fleece guide.
[0051] Figure 1 shows a combing machine 1 with, here only as an example, twelve combing heads K1-K12. Naturally, the abbreviated notation K1-K12 stands for K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12. The same applies to analogous abbreviations, such as for fiber tapes, reels, etc. Each combing head K1-K12 is fed its own reel W1-W12, which can have a width of approximately 300 mm and, for example, a winding fineness of 80 ktex. During the combing process, fibers are combed out from the unwound reels, torn off, and soldered back onto the previously combed fibers. The combed fibers are then bundled into separate fiber tapes F1-F12, each with, for example, 11.25 ktex, and deflected by approximately 90 degrees to a delivery table 5. From the storage table 5, a total of twelve fiber tapes F1 - F12 with a total tape weight of 135 ktex are transported to a drawing unit 10, which may be preceded by an inlet funnel 6.The fiber tape guided on the delivery table 5 can be pre-compacted by the inlet funnel 6 and reduced to a working width corresponding to the clamping line of the pre-drawing section. The twelve fiber tapes F1–F12 enter the drafting unit 10, which can be configured, for example, as a three-over-three, four-over-three, or four-over-four drafting unit. Here, they are drawn and doubled, and deposited as a single fiber tape FB into a can by means of a can tray 20. In this example, the twelve fiber tapes F1–F12 enter the drafting unit 10 with a total tape weight of approximately 135 ktex, can be drawn and doubled by a factor of 27, and deposited into a can with a weight of approximately 5 ktex by means of a can tray 20. With this fiber tape weight, the fiber tape runs through the drawing unit 10 at a higher speed of around 350 m / min than with an 8-head combing machine.In order not to unnecessarily shorten the can filling times of the depositing can, the fiber ribbon can be deposited in cans with a diameter of preferably at least 1,000 mm according to the combing machine according to the invention.
[0052] The drafting unit 10 is a motor-adjustable drafting unit for automatically adjusting the draft. Here, drafting unit 10 is shown as an example of a four-over-three drafting unit with three driven drafting rollers 10.1, 10.2, 10.3, comprising a pre-drafting section 8 and a main drafting section 9. The drafting rollers 10.1, 10.2, which effect the pre-drafting of the fiber strips F1 - F12, are driven by a main drive motor 16, which can also, for example, drive input rollers 7. [Internal file number P249904WO1 2026002472 / 24.03.2026]
[0053] The downstream pre-drawing section 8 and the drafting roller 10.3 effect the main drawing of the fiber strips F1–F12 in the main drawing section 9 and can be driven by a control motor 17 independent of the main drive motor 16. The two motors 7 and 16 are coupled to a control unit 18, which can, among other things, control the speeds of the motors 7 and 16. Other drive concepts that allow for drawing adjustment are also possible.
[0054] Figure 2 shows a perspective view of the area of the combing machine 1 between the drafting unit 10 and the canning unit 20. The last upper roller of the drafting unit 10 is visible; this is designed as a deflecting roller 11 in a manner known per se, and from this roller the drawn fiber strips F1 - F12 enter a web guide 12. In the web hopper 12d and the subsequent ribbon hopper 13, the twelve fiber strips F1 - F12 are formed into a single fiber strip FB, which enters the canning unit 20. Two take-off rollers 14 are arranged between the ribbon hopper 13 and the canning unit 20; these can serve as a measuring device 15 for determining the strip mass. Sensors can be provided for this purpose to determine the strip mass of the fiber strip FB. Such a measuring device could be, for example, the system known as "Disc Monitor" from Trützschler, or additionally or alternatively to the "Disc Monitor" the system called "Disc Leveller" upstream of the drawing machine.
[0055] During fiber sliver formation after the deflection roller 11 of the combing machine 1, the stretched fiber slivers F1–F12 are merged into a single fiber sliver FB in the web guide 12. The impact on the web guide 12 creates a tangled arrangement of the fibers, which increases sliver adhesion. Particularly due to the higher impact velocity of the fibers on the web guide 12 in a 12-head combing machine, the geometry of the web guide 12 is of special importance for fiber sliver formation and for increasing sliver adhesion. Following the web guide 12, the fiber sliver FB can be guided, as shown here, through the web hopper 12d and the sliver hopper 13, through take-off rollers 14 and a discharge tube into the can discharge tray 20.
[0056] Each machine stoppage at the combing machine leads to a change in the fiber guidance situation through the web guide 12. The impact of the fibers on the web guide 12 temporarily ceases, and a web triangle forms with a further increased parallel alignment of the fibers, as shown in Figure 2. These weak points in the web, in particular, frequently lead to production disruptions and quality losses in subsequent processes (unclean layer separation when the fiber web FB is pulled from the can, fraying of the fiber web FB after pulling from the can, misalignment and web breaks during guidance to the drafting unit of the following section).
[0057] The weaknesses that arise when operating the main drive motor 16 below an operating speed, sometimes even causing the textile machine 1 or the drafting unit to come to a standstill. Internal file number P249904WO1 2026002472 / 24.03.2026
[0058] The distortions that arise in the drawing unit 10 are compensated for or reduced by producing a higher strip mass. This is achieved by reducing the distortion in the drawing unit 10, so that the increased parallel alignment of the fibers can be compensated for with a higher strip mass. By reducing distortion in the drawing unit 10, the number of fibers in the strip cross-section is increased, thus increasing the strip adhesion, e.g., due to the higher fiber-to-fiber friction.
[0059] Figure 3 shows the method according to the invention in simplified form using a flowchart. In a first process step V10, an operating speed n_B of the main drive motor 16 of the combing machine 1, corresponding to a predetermined number of comb cycles – for example, 600 nips / min – is determined for production operation. This can be done, for example, by inputting a value into the controller 18, by retrieving a value stored in the controller 18, or by specification from the controller 18 or a higher-level controller. Furthermore, a target offset V_S for production operation can be determined.
[0060] In a subsequent process step V20, the combing machine 1 is operated in production mode at the actual speed of the main drive motor 16, which corresponds to the operating speed n_B. The combing machine 1 has several combing heads K1 - K12, each combing head being designed to be fed by at least one spool W1 - W12 or by at least one fiber tape from cans, with the combed fibers being gathered into separate fiber tapes F1 - F12 per combing head and transported to the discharge table 5. The individual fiber tapes F1 - F12 are fed to the drafting unit 10, where they are drawn with an actual draft V of the drafting unit 10. The actual draft V corresponds to the target draft V_S of the drafting unit specified by the control system 18.The drawn fiber strips F1–F12 are then combined into a single fiber strip FB in a nonwoven guide 12 downstream of the drawing unit 10 and optionally in further strip forming units 12d, 13, and deposited in a can. The actual draft V is constant during production operation, but can also be regulated if the measuring device 15 is present to control the desired production strip mass. However, production operation will usually begin with the target draft V_S and then be regulated.
[0061] In a subsequent process step V30, textile machine 1 is operated in special mode controlled by control unit 18, in which the actual speed n is reduced to the target speed n_S below the operating speed n_B, and the target delay is reduced depending on the actual speed n and / or the target speed n_S of the main drive motor 16. Internal file number P249904WO1 2026002472 / 24.03.2026
[0062] In a further process step V40, the actual speed n of the main drive motor 16 is increased to a changed target speed n_S, here again to the operating speed n_B, and the actual delay V is increased to the target delay n_S for productive operation.
[0063] Figure 4 shows a diagram illustrating the change in distortion V as a function of rotational speed n over time t. The left ordinate represents the rotational speed n of the combing machine 1, which in this embodiment can reach up to a combing rate of 600 nips / min. The horizontal range corresponds to the operating speed n_B, at which the textile machine 1 is intended to run continuously during production. In the following description, the actual rotational speed n of the main drive motor(s) 16 is assumed to be proportional to the combing rate nips / min, since the combing heads K1–K12 are connected to the main drive motor 16 via a gearbox. For multiple control motors 17, it is assumed that they are operated synchronously, allowing them to be controlled as a single main drive motor 16. The right ordinate shows the corresponding distortion V of the drafting unit 10. At operating speed n_B, the target delay V_S is, for example, a factor of 22.The abscissa of the diagram indicates the time course t.
[0064] Below a rotational speed of 600 nips / min, a horizontal area is shown hatched, which is referred to as the tolerance range T, in which the rotational speed can vary without affecting the distortion V, for example 5 nips / min, where the tolerance range T can also cover more or less, in particular 1, 2, 3, 4, 6, 7, 8, 9, 10 nips / min.
[0065] In principle, the tolerance range T could also be zero, allowing for immediate responses to fluctuations. This tolerance range T is intended to cover the range of fluctuations in the actual speed of the main drive motor 16 or in the number of passes during normal production, without the controller 18 specifying speed-related distortion changes. If the textile machine 1 leaves production operation, for example due to a malfunction, maintenance, a can change, etc., and the controller 18 reduces the target speed n below the operating speed n_B, the controller 18 initiates a special operation if a start condition is met, for example, if the actual speed n falls below the tolerance range T. The diagram shows two vertically hatched areas 21 and 22, which represent distortion adjustment ranges in which the drafting unit 10 reduces (area 21) or increases (area 22) the distortion V in special operation.Between the two areas 21 and 22 of the delay adjustment, an area 23 is shown, which represents a machine stop. This machine stop area 23 can be very short, non-existent, or very long if the machine is undergoing maintenance. The special operation only ends when the operating speed n_B is reached again. Internal file number P249904WO1 2026002472 / 24.03.2026.
[0066] For example, the continuous horizontal line L1 shows the operating speed n_B or comb count of 600 nips / min at the target draft of V = 22. When the textile machine 1 is slowed down to a stop with n = 0, the control unit 18 specifies the target speed, which here is defined, for example, by the linear line n_S. The draft V is reduced from the target draft V_S to a predetermined minimum draft V_min = 16 in the first stage 21 of the draft adjustment. When the machine is at a standstill, the actual draft V = 0, since no fiber strips F1 - F12 are being transported through the drafting unit 10. Different curves are shown to illustrate that the change in the target delay V can be made according to a curve stored in the control 18, where the curve can be linear, abrupt or characteristic curve-based.In the first section 21, the delay V follows, for example, the delay line L1 linearly or the delay line L2 abruptly from V_S = 22 to V_min = 16. After the machine stops, the delay V increases with the increasing speed n of the main drive motor 16, for example, linearly along the delay line L3 or abruptly along the delay line L4 from V_min = 16 to V_S = 22, whereby the target delay V can be reached, for example, upon reaching the operating speed n_B, whereby the change in delay V depends on a function stored in or specified by the control system 18. The change in delay can occur along any curve, which can, for example, also be concave or convex. The procedure for changing the delay of the stretching system 10 is valid for all arbitrary ramps for ascending and descending, where a reduction in speed until standstill or an increase in speed until the operating speed is reached takes place.
[0067] The reduction of distortion can be achieved by decreasing the distortion V in the main distortion section 9 of the drafting unit 10, in the area of the pre-distortion section 8, or by adjusting the distortion V in both areas of the drafting unit 10. In the embodiment shown here, the distortion adjustment is achieved by coupling the drafting unit roller 10.3 with the control motor 17, thereby regulating the speed of the drafting unit roller 10.3 and thus changing the distortion of the main distortion section. However, it is also possible for the drafting unit 10 to have a separately controllable control motor for both the pre-distortion and the main distortion sections.
[0068] In the downfeed ramp, this involves reducing the warpage down to the warpage value, here the minimum warpage V_min, at which the desired strip mass is achieved. This is achieved by an input to the control unit 18, where the minimum warpage value can be entered. Alternatively, in a preferred embodiment, the strip mass FB of the fiber strip can be detected online, for example, by the take-up rollers 14 with an integrated sensor behind the drafting unit 10, and transmitted to the control unit of the combing machine. After the combing machine 1 has come to a standstill in the upfeed ramp 23, the warpage is reduced by the Internal file number P249904WO1 2026002472 / 24.03.2026
[0069] The specified minimum value V_min is increased again until the production strip fineness or production delay V_S is reached again. This occurs as soon as the operating speed n_B is reached again, or until the limit of a predefined range for delay adjustment, which can be set, is reached.
[0070] Furthermore, it is possible that the reduction of the delay only begins after reaching a specific reduced speed value, which can be determined by the set value. The increase of the delay to the maximum value can also be completed at a specific speed value.
[0071] In the control unit 18 of combing machine 1, the amount of sliver mass added can be adjusted and stored variably, for example, for different cotton varieties, since their varying fiber lengths directly influence sliver adhesion. Similarly, the further processing of the fiber slivers FB in a subsequent machine can be stored in the control unit 18, as combing machine 1 is part of an overall process for processing fibers into finished yarn. If sliver breaks occur in the downstream machine, the distortion V can be further reduced. This can be done manually by an operator or automatically by a networked control system that collects data from all machines in the spinning mill and controls them accordingly. The control unit 18 of combing machine 1 can also take into account climatic conditions such as humidity in the spinning mill, since higher humidity tends to increase sliver adhesion and thus reduce the risk of sliver breakage.
[0072] As a result of the change in distortion when the speed of the combing machine 1 is changed, different strip masses are achieved, with which the strip adhesion values or
[0073] Strength levels in the areas of previous weaknesses can be changed.
[0074] Adjusting the mass of the fiber tape FB by changing the warp in the drafting unit 10 when changing the speed of the combing machine can be used on all combing machines regardless of the number of combing heads (8-head, 10-head, 12-head, 16-head). The goal remains a constant fiber tape with a mass of, for example, 5 ktex, independent of the number of combing heads, so that minimal adjustments are required on subsequent machines. A temporary increase in tape mass, for example, by 30% when leaving the operating speed to increase tape adhesion values to 6.5 ktex, is possible and can be useful if tape breaks are increased on subsequent machines. Otherwise, the tape mass is only increased when necessary.
[0075] Figure 5 shows another diagram depicting the change in distortion V as a function of rotational speed n over time t. The rotational speed n of combing machine 1 is shown on the left ordinate. Internal file number P249904WO1 2026002472 / 24.03.2026
[0076] In this embodiment, without specifying a particular value, the warpage can be up to the operating speed n_B with a combing cycle count of, for example, 600 nips / min. The corresponding warpage V of the drafting unit 10 is assigned to the right ordinate. The abscissa indicates the time course t. For the commonalities, reference is made to the preceding explanations. In the example shown here, the special operation starts when the tolerance range T is undershot, whereby the warpage adjustment only takes place when the range 21, defined by a speed range nv, is reached. In the control 18 of the combing machine 1, for example, a start and end point for the adjustment can be entered. In this range 21, the warpage V is reduced from the target warpage V_S along the curve L5 by a predefined differential warpage AV. Instead of a differential warpage AV, the minimum warpage V_min can also be specified.This range is defined by a start and end point for the distortion reduction. However, curves can also be stored in the control unit 18 of the combing machine 1 that represent this delayed distortion range. Depending on the set start and end points for the distortion reduction range, a certain strip length with the maximum strip mass is produced, for example, after reaching the maximum distortion change. This occurs, for instance, by the maximum distortion reduction being present at 10% or 20% before the machine comes to a standstill. In this embodiment, the distortion change only begins after a speed reduction of approximately 20%. The end of the distortion adjustment range 21 occurs at about 20% of the target speed n_S. The range in between is shown as the speed range nv in Figure 5. The delay in the start of the distortion adjustment results in a reduction of the length of the fiber strip FB, which has a higher strip mass.Ending the warpage adjustment before reaching standstill results in a greater length of fiber strip being produced with minimal warpage and thus maximum strip mass. This ensures that the fiber strip is strengthened to its maximum strength for a longer period in the most critical area. During ramp-up, the same limits and the same speed range nv apply, within which the warpage V is increased again. Alternatively, different speed ranges can be specified for the ramp-up and ramp-down of the warpage.
[0077] Advantageously, the distortion can be reduced immediately after leaving the operating speed n_B, in order to have the maximum strip mass in the fiber strip FB only for a certain time in the low speed range, so that the fiber strip FB is particularly strengthened here.
[0078] The reduction or increase of the distortion V can be linear, as shown here with line L5, or abrupt, or along any curve stored in the control system, as shown, for example, in Figure 5, by a combination of an initially linear progression until the differential distortion AV is reached, and then a constant progression until the rotational speed n = 0 is reached, at which point the actual distortion V consequently becomes zero. Internal file reference P249904WO1 2026002472 / 24.03.2026
[0079] The above statements can also be applied analogously to a track with the previously described motor-adjustable track system 10.
[0080] Figure 6 shows a nonwoven guide 12 with an impact surface 12a, onto which the fiber strands F1-F12 from the drafting unit 10 impact and are formed into the single fiber strand FB by the nonwoven funnel 12d. The impact surface 12a is concave and tapers continuously from both sides towards the discharge opening 12b. The illustration in Figure 6 shows the impact of the fiber strands F1-F12 onto the impact surface 12a during normal or productive operation of the combing machine 1 or drafting unit, in which the parallel alignment of the fibers to each other is largely avoided. When the rotational speed of the combing machine or line is reduced and the speed of the fiber strips F1-F12 through the drawing unit 10 is reduced, the fiber strips tend to exit the drawing unit 10 without impacting the impact surface 12a and go directly to the discharge opening 12b, as indicated in Figure 2.
[0081] By introducing compressed air and selectively applying compressed air to the fiber material, preferably with a swirl nozzle arranged in the discharge opening 12b, the parallel alignment of the fibers can be reduced and the tape adhesion of the fiber tape FB increased. This is one way to further increase tape adhesion in addition to the previously described automatic warpage adjustment.
[0082] Preferably, the valve connection 12c can be arranged off-center above the nonwoven hopper 12d at the discharge opening 12b, so that a swirl is generated by the incoming air, at least on the outer circumference of the fiber ribbon FB. Alternatively or additionally, a swirl nozzle (not shown) can be arranged within the discharge opening 12b, the air channels of which vary in number, size, or by being arranged off-center and / or inclined, thus generating a swirl on the fiber ribbon FB and reducing the parallel alignment of the fibers. The swirl nozzle can be interchangeable, so that different effects on the swirling of the fibers can be achieved by changing the nozzle geometry. This allows different swirl nozzles to be adapted and used according to the fiber qualities employed.
[0083] By varying the nozzle pressure, e.g., from 1.0 to 2.5 bar, different degrees of consolidation can be achieved. The applied pressure can be adjusted depending on the delivery speed; for example, the turbulence can be intensified as the number of comb passes or the delivery speed of the drafting unit decreases. The advantageous embodiment allows for at least partial compensation of process-related weaknesses or even an improvement in strip adhesion in this area. Depending on the fiber quality, the nozzle type of the swirl nozzle can be selected and adapted to the material. The advantageous embodiment (Internal file number P249904WO1 2026002472 / 24.03.2026)
[0084] is easy to implement, since the drafting unit 10 on the last upper rollers is at least temporarily supplied with compressed air to prevent fiber accumulation.
[0085] The reduction of the parallel alignment of the fibers and the associated higher tape adhesion by the lateral injection of air into the air nozzle 12c of the nonwoven guide 12 can complement the change in distortion of the drawing unit.
[0086] Figure 7 shows another embodiment of the nonwoven guide 12, in which tangled layer elements 12f are arranged within the concave impact surface 12a. The number, arrangement, height, and extent of these elements can vary. The tangled layer elements 12f divide the mass flow of the individual fiber strands F1–F12 after the drafting unit 10 during the formation of the fiber strand FB. The drawn fiber strands are guided centrally through the discharge opening 12b into the nonwoven funnel 12d and then via the outlet opening 12e into the strand funnel 13. The fiber flow from the externally impacting fiber strands is deflected by the tangled layer elements 12f. This effect can be enhanced by an aggressive impact edge (not shown) to increase strand adhesion. This measure can also reduce the parallel alignment of the fibers and thus achieve higher strand adhesion, in addition to the change in distortion of the drafting unit.By optimally orienting the fibers in the nonwoven fabric, the nonwoven guide tension, which is generated by the roller 11 of the drafting unit 10 and the take-off rollers 14, can be kept to a minimum.
[0087] The design of the tangled layer elements on the concave impact surface 12a is such that no areas for fiber accumulation are present. The width of the nonwoven guide 12 with its impact surface 12a is adapted to the width of the supplied fiber strips, which depends on the number of comb heads or the number of doublings in the drafting unit 10.
[0088] In Figure 8, the impact surface 12a is formed as a flattened triangle by the dashed line. The dotted line shows an impact surface 12a that is approximately cup-shaped and tapers towards the outlet opening. Both embodiments of Figures 7 and 8 can be combined with air turbulence by means of a laterally arranged air nozzle 12c, preferably with a swirl nozzle arranged in the exhaust opening 12b. Internal file number P249904WO1 2026002472 / 24.03.2026 Reference number
[0089] 1 Combing machine t time course 5 Delivery table T tolerance range 6 Infeed hopper V distortion drawing unit 7 Infeed rollers AV distortion range 8 Pre-distortion field W1 - W12 winding
[0090] 9 Main delay field
[0091] 10 Stretching machine
[0092] 10.1, 10.2, 10.3 Stretcher roller
[0093] 11 Deflection roller
[0094] 12 nonwoven guides
[0095] 12a Impact area
[0096] 12b Extraction opening
[0097] 12c valve connection
[0098] 12d fleece funnel
[0099] 12e Exit opening
[0100] 12f Irrrlagenelement
[0101] 13 belt funnels
[0102] 14 take-up rollers
[0103] 15 Measuring device
[0104] 16 Main drive motor
[0105] 17 Control motor
[0106] 18 Control
[0107] 20 can holders
[0108] Areas 21, 22, 23
[0109] FB Fiber Tape
[0110] F1 - F12 Fiber tape
[0111] K1 - K12 Comb head
[0112] L1; L2, L3, L4; L5 Delay curves
[0113] n rotational speed
[0114] n_B Operating speed
[0115] n_S Target speed
[0116] n v Speed range
Claims
Internal file number P249904WO1 2026002472 / 24.03.2026 Patent claims 1. Method for automatic distortion adjustment in a textile machine (1), in particular a combing machine or a drawing machine, with a motor-adjustable drawing unit (10) for drawing pre-prepared fiber strips (F1 - F12) and a control system (18), comprising the steps: (V10) Providing an operating speed (n_B) of a main drive motor (16) of the textile machine (1) for productive operation of the textile machine (1); (V20) Operating the textile machine (1) in production mode with an actual speed (n) of the main drive motor (16) corresponding to the operating speed (n_B) and with an actual draft (V) of the drafting unit (10) corresponding to a target draft (V_S) of the drafting unit (10) specified by the control (18), wherein the drawn fiber strips (F1 - F12) are combined into a single fiber strip (FB) by means of a nonwoven guide (12) downstream of the drafting unit (10) and deposited in a can, characterized in that the method further comprises: (V30) Operating the textile machine (1) in a special operation controlled by the control system in which the actual speed (n) is reduced to a target speed (n_S) below the operating speed (n_B) and the target delay (V_S) is reduced depending on the actual speed (n) and / or the target speed (n_S) of the main drive motor (16).
2. Method according to claim 1, characterized in that the control system starts the special operation when a start condition is met, for example when the actual speed (n) falls below a predetermined speed threshold or leaves a tolerance range (T) around the operating speed (n_B) or the control system receives a stop signal.
3. Method according to claim 2, characterized in that the reduction of delay occurs with a time delay after the starting condition has been fulfilled.
4. Method according to one of claims 1 to 3, characterized in that the control in special operation initiates a controlled machine stop of the drawing unit (10) and in particular of the textile machine (1), in which the actual speed (n) of the main drive motor (16) is reduced along a predetermined target speed curve (n_S) to the speed n = 0 and during this speed reduction the delay (V) is reduced.
5. Method according to one of claims 1 to 4, characterized in that the delay (V) during the reduction of the actual rotational speed is reduced to a predetermined minimum delay. Internal file number P249904WO1 2026002472 / 24.03.2026 (V_min) is reduced and maintained as long as a non-zero value is reached. The actual rotational speed, or n > 0, is present.
6. Method according to one of claims 1 to 5, characterized in that the control system, upon receiving a start signal, initiates a controlled machine start of the drafting unit (10) and in particular the combing machine (1), in which the The actual speed (n) of the main drive motor (16) is increased along a predetermined target speed curve (n_S) to the operating speed (n_B) and during this speed increase the delay (V) is increased to the target delay (V) in order to operate the textile machine (1) in productive operation again when the operating speed (n_B) is reached.
7. Method according to one of claims 1 to 6, characterized in that the change of the target delay (V_S) is carried out according to a curve stored in a control (18) of the textile machine (1), wherein the curve can be linear, step-by-step or characteristic curve-based.
8. Method according to one of claims 1 to 7, characterized in that the delay adjustment is carried out by changing a preliminary delay, a main delay or both delay zones in the drawing machine (10), wherein at least one of the delay zones has an independently controllable control motor.
9. Method according to one of claims 1 to 8, characterized in that in production operation the actual delay either corresponds constantly to the target delay (V_S) or, if the control (18) is connected with a measuring device (15) for determining a strip mass of the fiber strips (F1 - F12) and / or the fiber strip (FB), is regulated in order to keep the strip mass at least as constant as possible in production operation.
10. Method according to one of claims 1 to 9, characterized in that the textile machine (1) is designed as a combing machine (1) with several combing heads (K1 - K12), wherein the combed fibers are combined into a separate fiber ribbon (F1 - F12) per combing head (K1 - K12) and transported to a depositing table (5), fed to the drawing unit (10) and drawn to the single fiber ribbon (FB) by means of the nonwoven guide (12) and optionally subsequent ribbon forming units (12d, 13) and deposited in the can.
11. Combing machine (1) with several combing heads (K1 - K12), a lay-up table (5), a motor-adjustable drawing unit (10), a nonwoven guide (12) and optionally subsequent strip forming units (12d, 13) and a control unit (18), characterized in that the control unit (18) is used to carry out a process according to an Internal file number P249904WO1 2026002472 / 24.03.2026 of claims 1 to 10, wherein the control (18) controls at least one control motor of the drafting unit (10) to reduce or increase the roller speed of the driven drafting unit rollers.
12. Stretching unit (1), in particular pre-stretching unit, with a motor-adjustable drafting unit (10), a nonwoven guide (12) and optionally subsequent strip forming units (12d, 13) and a control unit (18), characterized in that the control unit (18) is designed to carry out a method according to one of claims 1 to 10, wherein the control unit (18) controls at least one control motor of the drafting unit (10) to reduce or increase the roll speed of the driven drafting unit rolls.