Revolving flat card

Abstract

The invention relates to a method for operating a revolving flat card (1) and to a revolving flat card (1). The revolving flat card (1) has a controller (2) comprising an input module (3), a feed (6) and a cylinder (8) fitted with a cylinder clothing (9). A carding gap width (12) is formed between an outer surface (10) of the cylinder clothing (9) and a flat clothing (15). The revolving flat card (1) also has a carding gap width measurement arrangement (33) and an actuator (31) for adjusting the carding gap width (21) and a drive (42) for controlling a rotation speed of the cylinder (8). The input module (3) measures a process temperature, detects a target process temperature together with an associated maximum process temperature and detects a control range and a maximum value for the carding gap width (21), The controller (2) controls the target process temperature by adjusting the carding gap width (21) and / or the feed (6) and / or a rotation speed of the cylinder (8).

Description

[0001] OBJ-3594P 10.03.2023 REVOLVING-FLAT CARD The present invention relates to a method for operating a revolving-flat card and to a revolving-flat card. Revolving-flat cards are used in spinning preparation plants and contain various working elements for cleaning, sorting, opening, carding, etc., the fiber material to be processed. A wide variety of fiber types are processed, including cotton fibers or synthetic fibers or mixtures thereof. In the revolving-flat card, the revolving-flat unit, together with the drum, forms the main carding zone and has the function of breaking down fiber flocks into individual fibers, separating impurities and dust, eliminating very short fibers, breaking up neps, and parallelizing the fibers.Viewed in the direction of drum rotation, there is a pre-carding zone upstream of the revolving flat unit and a post-carding zone downstream of the revolving flat unit, both of which also feature cleaning and carding elements. Fiber guide elements are arranged on the outer surface of the drum between the cleaning elements or at the transition from one carding zone to the next. These guide the fibers transported by the drum. This holds the fibers on the drum, and the air entrained by the fibers is also subject to limited air exchange. During processing of the fiber material, heat is generated due to fiber friction, which is reflected in the process temperature.The temperature around the circumference of the drum is generally highest at the point where the fiber material leaves the main carding zone, since a carding gap formed in the main carding zone normally narrows continuously from inlet to outlet, increasing the carding work and thus also the heat generation. OBJ-3594P March 10, 2023 The permissible maximum process temperature depends, among other things, on the fiber material to be processed. The focus here is on synthetic fibers, also known as man-made fibers (MMF) or chemical fibers. Synthetic fibers include polyamide, polyester, polyacrylic, and elastane. The so-called glass transition temperature plays an important role in the properties of polymeric materials. It is one of the most important parameters of polymers and provides an indication of the dimensional stability of the plastic when exposed to heat.The glass transition temperature is the temperature at which fully or partially amorphous polymers transition from the highly viscous or rubber-elastic, flexible state to the glass-like or hard-elastic, brittle state. Therefore, it is also called the softening temperature. Every plastic has a specific glass transition temperature by which it can be characterized. There is no clear definition for the softening temperature. It is usually below the melting temperature. The softening range is recognizable by the fact that even small external stresses lead to permanent deformation. During fiber processing, for example in a revolving flat card, the softening range must under no circumstances be reached during fiber processing, as this has a negative impact on the subsequent use of the fibers, for example in a dyeing process.In contrast, however, a high quality card sliver can only be achieved with good carding. A compromise between carding strength and production output is necessary in order to keep the process temperature within an acceptable range. For this, it is necessary to know the temperatures prevailing during the carding process. Various approaches to operating a revolving flat card based on the prevailing temperatures in the revolving flat card are known from the prior art. For example, DE 102005 038401 A1 discloses a control of a carding gap width and thus the carding quality based on a measurement of the temperature of the drum surface and the side plates holding the drum and the revolving flat unit. OBJ-3594P 10.03.2023 Furthermore, EP 3431642 A1 discloses a control of a carding gap width and thus the carding quality based on a measurement of the temperature at a carding element.The carding gap width is controlled based on the measured temperature and a shape change model. In these known processes, the carding quality is controlled without taking into account the process temperature, i.e., the temperature prevailing in the fiber material. Based on the experience of the operating personnel, the production output is adjusted to the desired carding quality in such a way that the process temperature is within a range where no damage is caused to the fiber material. As a precautionary measure, a high level of safety is ensured by setting a low production output without knowing the actual process temperature.The object of the present invention is to propose a method for operating a revolving flat card and a revolving flat card which enables operation adapted to the fiber material to be processed, whereby the highest possible productivity is achieved with the required product quality. This object is achieved by the features in the characterizing part of the independent patent claims. To achieve this object, a method for operating a revolving flat card is proposed, wherein the revolving flat card has a control system with an input module and a feed for supplying fiber material and a machine frame and a drum equipped in the machine frame with a drum assembly and held rotatably about a longitudinal axis. With the help of the drum assembly, the fiber material is taken from the feed and held on the drum surface.Furthermore, the revolving flat card has a revolving flat unit with a plurality of carding elements, wherein the carding elements each have a flat clothing and are held on at least one flexible arch OBJ-3594P 10.03.2023 on both sides of the drum in the direction of the longitudinal axis. As the drum rotates, the fiber material is guided past the carding elements of the revolving flat unit. A carding gap with a carding gap width is formed between an outer surface of the drum clothing and a plane of the flat clothing facing the drum clothing. The fiber material guided through this carding gap is cleaned by the flat clothing of the carding elements and the fibers are parallelized. The revolving flat card has a carding gap width measurement and an actuator for adjusting the carding gap width by adjusting the flexible arches.Various devices for measuring the carding gap width are known from the prior art. In each case, a measurement of contact between the flat clothing and the cylinder clothing is detected and then, starting from this zero point of the carding gap width, a predetermined carding gap width is set by the actuator system. The basis for setting the carding gap width is knowing when this is zero, i.e. when contact occurs between the opposing components. In this way, existing setting devices can be easily calibrated, taking into account the design conditions of individual components such as the flexible bend and carding element. By precisely detecting contact, the carding gap can be maintained precisely and, at the same time, damage to the components can be avoided.Contact measurements for detecting contact between the cover fitting and the drum fitting are known in various designs from the prior art. For example, DE 102006002812 A1 discloses a device in which the drum and the covers are electrically insulated from one another. As respective contact elements, the drum and the covers are connected to an electrical circuit in which a measuring element for contact detection is located. Furthermore, DE 3913996 A1 discloses sensors for measuring a distance between fittings, with capacitive, inductive, and optical sensors being mentioned here. A measurement by spark discharge is disclosed in OBJ-3594P 10.03.2023 WO 2008055367 A1. CH 695351 A5 discloses a measurement of structure-borne sound for detecting contact between the drum fitting and the cover fitting.It is also known that the flexible arches must be designed to be radially adjustable in order to ensure a carding gap that is constant over the entire length of the flexible arch or that can be varied according to requirements. Actuators of various designs are used for this purpose. For example, EP 1201797 discloses a device in which the flexible arch is supported on rotatably mounted rollers, the rollers being designed as rotatable, helical cams. The flexible arch is raised or lowered by rotating the cams. Furthermore, EP 2392703 A1 discloses a device in which the flexible arch is held on an eccentrically mounted bolt. EP 3 124657 A1 discloses a device in which the flexible arch is mounted on a bearing bolt that is connected to an adjusting lever and is provided with a spiral-shaped surface.The adjustment lever causes the bearing pin to rotate, which subsequently leads to a radial adjustment of the flexible bend. The actuator drives can be pneumatic, electric, or electro-pneumatic. The revolving flat card also has a drive for regulating the speed of the drum. The speed of the drum influences the carding intensity. At a high speed of the drum, a correspondingly high peripheral speed results on the surface of the drum that supports the drum clothing. The fiber material is guided past the carding elements at this peripheral speed. The higher the speed of the fibers, the more intensive the carding, with a correspondingly high development of heat at the carding point. Based on the required carding intensity, a drum speed is assigned to the amount of fiber supplied by the feed. OBJ-3594P 10.03.2023 For the method according to the invention, a process temperature is measured, wherein the process temperature corresponds to a temperature prevailing in the fiber material in the carding nip. A corresponding process temperature measurement is to be arranged in such a way that the measurement detects a process temperature prevailing in the fiber material or in an air layer surrounding the fiber material. The process temperature measurement is preferably arranged centrally along the longitudinal axis of the drum. In addition, a process temperature measurement can be provided at the respective ends of the drum for improved determination of the current process temperature. A process temperature measurement from an inner side of the drum is also possible. Viewed in one operating direction of the drum, a process temperature measurement with an optical measurement or a temperature sensor is advantageously provided downstream of the revolving flat unit.A suitable temperature sensor, for example, is a resistance thermometer in a Pt100 sensor version. The measurement technology is based on a platinum precision resistor, which changes its electrical resistance depending on the temperature. The measuring resistor can be designed as a thin-film element or as a wire resistor. The platinum material makes it very stable over the long term. The Pt100 measuring resistor has a nominal resistance of 100 ohms at a temperature of 0 °C. Pt100 resistance thermometers are based on a resistor whose electrical resistance value increases with rising temperature. They deliver precise results over wide measuring ranges and are also very stable over the long term. The measuring resistor is installed in the temperature sensor as close to the fiber material as possible. The input module also records a target process temperature and a corresponding maximum process temperature.The maximum process temperature results from the characteristic properties of the fiber material to be processed and is derived from the glass transition temperatures of the materials used for the fibers. For example, the glass transition temperature of polyester ranges from 68°C to 80°C, depending on the fiber manufacturing process. OBJ-3594P 10.03.2023 In this case, the maximum process temperature would be set a few degrees below the current glass transition temperature of the fibers to be processed. Accordingly, the target process temperature should be set a few degrees below the maximum process temperature to prevent the maximum process temperature from being reached immediately if the target process temperature is exceeded due to control inertia.For example, if the glass transition temperature of the fiber material currently being processed is 75°C and the selected maximum process temperature is 72°C and the target process temperature is 68°C, there is an upper control range of 7°C before the glass transition temperature is reached. The input module also records a control range for the carding gap width and a maximum value for the carding gap width. During the carding process, the flat clothing engages the fiber material transported by the drum, thereby cleaning and parallelizing the fibers. The deeper the flat clothing engages, the more intensive the carding and the higher the quality of the processed fiber material. Depending on the fiber material and the required quality, the control range is selected, for example, to be 0.2 mm, with the maximum value set at 0.4 mm. Using these exemplary values, the control subsequently adjusts the carding gap width between 0.2 mm and 0.4 mm, whereby the maximum value of the carding gap width, in this case 0.4 mm, is not exceeded to maintain product quality. The control system regulates the process temperature by adjusting the carding gap width and / or the feed and / or the speed of the drum. When controlling using the carding gap width, the carding gap width is adjusted within the specified range. If the current process temperature is below the target process temperature, the carding gap width is reduced accordingly, whereby the specified range is not exceeded. Especially during the start-up phase of the revolving flat card, a certain amount of time is necessary to reach the process temperature. Is the current OBJ-3594P 10.03.2023 If the process temperature is above the target process temperature, the carding gap width is increased accordingly, which reduces carding intensity and, due to a correspondingly lower heat development, also reduces the process temperature. With control using the feed, the amount of fiber material fed in is adjusted. If the current process temperature is below the target process temperature, the feed of fiber material is increased and thus the amount of fiber material fed through the carding gap is increased. If the current process temperature is above the target process temperature, the feed of fiber material is reduced. With control using the drum speed, the drum speed is increased to reduce the process temperature and vice versa. A complementary combination of the different control systems can also be used to solve the task.Through this operation of the revolving flat card, the greatest possible productivity can be achieved with a specified product quality without exceeding the glass transition temperature. Alternatively, instead of directly recording the target process temperature and the associated maximum process temperature, an identifier for the fiber material is entered in the input module. Based on the identifier of the fiber material, the control system can access data stored in the control system for the fiber material corresponding to the identifier. The identifier can be present as a number, a name, or a code, for example, and can be recorded accordingly by the input module. Alternatively, instead of directly recording the control range of the carding gap width and the maximum value of the carding gap width, a quality specification for the processed fiber material is entered in the input module.Based on the quality specification, the control system can access data stored in the control system for the quality specification. The quality specification can be present, for example, as a quality level or as a code and can be recorded accordingly by the input module. OBJ-3594P March 10, 2023 In a further development of the process, the quality specification is already included in the fiber material identifier, and separate recording of the quality specification is not necessary if the fiber material identifier is present. For this purpose, the fiber material identifier contains the control range of the carding gap width and a maximum value of the carding gap width for the quality specifications corresponding to the fiber material. This eliminates the need for separate recording of the control range of the carding gap width and the maximum value of the carding gap width.Advantageously, the fiber feed is reduced when the maximum carding gap width and the maximum process temperature are reached simultaneously. If the process temperature rises to the maximum process temperature despite the carding gap width being set to the maximum, the fiber feed is reduced so that the current process temperature returns to the target process temperature. This prevents a loss of quality due to excessive productivity. Advantageously, at least one of the following temperatures is measured and taken into account by the control system as a correction factor when regulating the target process temperature: drum temperature, machine frame temperature, carding element temperature, flexible sheet temperature.The temperatures of the devices surrounding the carding process, such as the drum, the machine frame, the flexible sheets, or the carding elements, influence the process temperature by dissipating or supplying heat to the carding process. The temperature of the flexible sheets, the drum, and also the machine frame also influence the carding gap width. These temperatures are used to correct the control of the target process temperature in the control system by evaluating a control deviation between the target and actual process temperature and correcting the resulting required adjustment of the carding gap width or slowing or accelerating the control system's response. OBJ-3594P March 10, 2023 Advantageously, an ambient temperature is measured and taken into account by the control system as a correction factor in the control of the target process temperature.The temperature of the air surrounding the carding process, for example in the area around the revolving flat unit, influences the temperature development in the carding process through a cooling effect. Preferably, the temperatures are measured separately on both sides of the revolving flat card, viewed in the direction of the longitudinal axis. This makes it possible to determine any asymmetry in a temperature profile and, as a result, to avoid exceeding the maximum process temperature across the entire working range of the revolving flat card. The asymmetry of the temperature profile can be caused by an inclination of the carding gap viewed in the direction of the longitudinal axis. An inclination of the temperature profile can also arise due to the usually one-sided arrangement of a revolving flat card drive.By arranging separate process temperature measurements on both sides of the drum, any occasional exceedance of the glass transition temperature of the fiber material being processed is also avoided. Preferably, if the maximum carding gap width is not reached, the fiber feed is increased. If the maximum carding gap width is not reached, productivity can be increased without loss of quality by increasing the fiber feed. In an alternative embodiment of the method, the control range of the carding gap width comprises a single value corresponding to the maximum carding gap width, with the target process temperature being controlled via the fiber feed.As the feed rate increases, the amount of fiber material fed to the drum increases, which increases the carding intensity due to the greater loading of the drum with fiber material, or an increase in the drum speed and thus OBJ-3594P 10.03.2023 an increase in the speed at which the fiber material is passed past the carding elements. As the carding intensity increases, the process temperature also increases. This alternative procedure enables the process temperature to be controlled using a revolving flat card, which has a simple actuator system for adjusting the carding gap width that is not suitable for automatic adjustment of the carding gap width. Furthermore, a revolving flat card for processing fiber material with a control system with an input module is proposed.The revolving flat card has a feed system for feeding the fiber material, a machine frame, and a drum fitted with a drum clothing in the machine frame and mounted so as to rotate about a longitudinal axis. Furthermore, the revolving flat card has a revolving flat unit with a plurality of carding elements, each carding element having a flat clothing and being held on at least one flexible bend on either side of the drum in the direction of the longitudinal axis. A carding gap with a carding gap width is formed between an outer surface of the drum clothing and a plane of the flat clothing facing the drum clothing. The revolving flat card has a carding gap width measurement device, an actuator for adjusting the carding gap width by adjusting the flexible bends, and a drive for regulating the speed of the drum.Furthermore, a process temperature measurement is provided, whereby the process temperature corresponds to a temperature prevailing in the fiber material in the carding gap. The carding gap width measurements and process temperature measurements are described above. The actuator for adjusting the carding gap width can be a mechanical, manually operated or fully automated adjustment device. Furthermore, the revolving flat card has a detection of a target process temperature with a corresponding maximum process temperature via the input module, as well as a detection of a control range for the carding gap width and a maximum value for the carding gap width via the input module. The control system OBJ-3594P 10.03.2023 provides for regulation of the target process temperature by adjusting the carding gap width and / or the feed and / or the drum speed.A revolving flat card equipped in this way has the advantage that high productivity can be achieved while operating as close as possible to the maximum process temperature, without any loss of quality. The input module is advantageously designed as a keyboard or a reader. The keyboard can be installed directly into the control system of the revolving flat card. State-of-the-art readers for recognizing machine-readable codes, such as QR or bar codes, can be provided as the reader. The reader can be wired to the control system or built directly into the front of the control system. The input module is preferably equipped with remote access. Remote access allows a smartphone or tablet, for example, to be used as an input module. An input module equipped with voice recognition is also conceivable.A central database can also be provided as an input module via remote access. Advantageously, the control system is assigned corresponding data for a target process temperature and a maximum process temperature to the fiber material identifier. It is also advantageous if the control system is assigned corresponding data for a control range and a maximum value for the carding gap width to the quality specification. By storing the corresponding data records in the control system, input and recording of the necessary data is simplified and errors can be avoided. Further advantages of the invention are described in the following exemplary embodiments. They show: Figure 1 a schematic representation of a side view of a revolving flat card; OBJ-3594P 10.03.2023 Figure 2 is an enlarged view of area X according to Figure 1; Figure 3 is a schematic view of a cross section of an embodiment of the revolving flat card; Figure 4 is a schematic view of a cross section of a further embodiment of the revolving flat card; and Figure 5 is a schematic view of a detail of a revolving flat card of a further embodiment. Figure 1 is a side view of a schematic representation of a revolving flat card 1 according to the prior art. The revolving flat card 1 has a machine frame 22 and a control system 2. An input module 3 is provided in the control system 2. The fiber material 4 to be carded, which can consist of chemical fibers or mixtures of chemical fibers with natural fibers, is filled into a filling chute 5 in the form of roughly cleaned and dissolved fiber flakes.From the filling chute 5, the fiber material 4 is fed to a feed 6 and taken over in the form of a batt of fiber flakes by a licker-in or licker-in 7. The licker-in 7 can be formed from a single or multiple licker-in rollers. From the licker-in 7, the fiber flakes are transferred to a spool or drum 8. The fiber flakes are separated into individual fibers on the drum 8, parallelized, and cleaned. The drum 8 is equipped with a drum assembly 9 on its outer circumference. The fiber material carried by the drum assembly 9 passes through the drum 8, which rotates in an operating direction 11 about a longitudinal axis 12, into the area of ​​a main carding zone, which is formed in cooperation with a revolving flat unit 13 arranged above the drum 8. The revolving flat unit 13 is provided with schematically shown, rotating carding elements 14, which are equipped with flat clothings 15.A carding nip 20 is formed between the drum clothing 9 and the flat clothings 15, through which the fiber material passes. The individual carding elements 14 are connected to one another and assembled to form an endlessly circulating chain 17. The chain 17 is moved endlessly in a working direction 19 OBJ-3594P 10.03.2023 in the revolving flat unit 13 via deflection rollers 18 by a drive (not shown). The working direction 19 of the carding elements 14 is usually opposite to the operating direction 11 of the drum 8. The carding elements 14 are guided along the drum 8 with a flexible bend 29. The drum 8 is rotatably mounted in a machine frame 22 of the revolving flat card 1 along the longitudinal axis 12 and via bearings (not shown). The longitudinal axis 12 is connected to a drive of the revolving flat card 1, which is not shown in detail.Following the revolving flat unit 13, the carded fiber material reaches the area of ​​a rotatably mounted doffer 23, which transfers the fiber material removed from the drum 8 to a rotatably mounted doffer roller 24. The doffer roller 24 conveys the fiber material removed by the doffer 23 via guide devices (not shown in detail) to a downstream pair of press rollers 25, which delivers the fiber material to a fleece funnel 26 via further guide means (not shown) (e.g., a cross conveyor belt). The fiber material formed in the fleece funnel 26 is calendered in the form of a card sliver 28 by a downstream pair of calender rollers 27 and transferred to a sliver depositor (not shown). Figure 2 shows an enlarged view of area X according to Figure 1. Two carding elements 14 are arranged on the chain 17, shown in detail. The carding elements 14 are each equipped with a flat clothing 15 on one side associated with the drum 8.The flat clothing 15 is formed from a plurality of pointed wire hooks, which form a plane 16. The drum 8, arranged opposite the carding elements 14, is provided with a drum clothing 9. The tips of the drum clothing 9 form the outer surface 10 of the drum clothing 9. A carding gap 20 with a carding gap width 21 is formed between the plane 16 of the flat clothing 14 and the surface 10 of the drum clothing 9. During operation, the drum 8 is moved in an operating direction 11 and the chain 17 in a working direction 19. OBJ-3594P 10.03.2023 Figure 3 shows a schematic representation of a cross section of an embodiment of the revolving flat card 1 with a drum 8 and a carding element 14. The drum 8 is driven by a drive 42 and is provided on its outer circumference with a drum set 9, the tips of which form the outer surface 10.The drum 8 is mounted with its longitudinal axis 12 in a machine frame 22. The carding element 14 is equipped with a flat clothing 15 on a side facing the drum 8, the tips of which form the plane 16. The carding gap 20 with the carding gap width 21 is formed between the surface 10 and the plane 16. The carding element 14 is mounted and guided on both sides of the drum 8 on a first flexible arch 29 and a second flexible arch 30, respectively. An actuator 31 is provided between the machine frame 22 and the flexible arches 29 and 30, with which a distance between the plane 16 and the surface 10 can be adjusted. On the longitudinal axis 12, a structure-borne sound sensor 32 is shown as an example, which is connected to a carding gap width measurement 33 containing an evaluation. In the area of ​​the carding gap 20, a process temperature measurement 34 is shown.Figure 4 shows a schematic representation of a cross-section of a further embodiment of the revolving flat card 1 with a drum 8 and a carding element 14. The drum 8 is provided on its outer circumference with a drum clothing 9, the tips of which form the outer surface 10. The drum 8 is mounted with its longitudinal axis 12 in a machine frame 22. The carding element 14 is equipped with a flat clothing 15 on a side facing the drum 8, the tips of which form the plane 16. The carding gap 20 with the carding gap width 21 is formed between the surface 10 and the plane 16. The carding element 14 is mounted and guided on both sides of the drum 8 on a first flexible arch 29 and a second flexible arch 30, respectively. Between the machine frame 22 and the flexible arches 29 and 30, an actuator 31 is provided with which a distance between the plane 16 and the surface 10 is adjusted OBJ-3594P 10.03.2023 can be. In the illustration shown, an inclination of the carding element 14 with respect to the longitudinal axis 12 is shown. Such an inclination can arise due to manufacturing tolerances or different temperature-related expansion of the individual components. To measure the carding gap width 21, a current sensor 36 is provided between the carding element 14 and the drum 8, for example, which is connected to a carding gap width measurement 33 containing an evaluation. The carding element 14 and the drum 8 are electrically insulated from one another via an insulation 35, so that a current flow can only be detected by the current sensor 36 or the evaluation when the flat clothing 15 and the drum clothing 9 are in contact. In the embodiment shown, a process temperature measurement 34 is provided on both sides of the drum 8, as seen along the longitudinal axis 12.Figure 5 shows a schematic representation of a detail of a view of a revolving flat card 1 of a further embodiment. The revolving flat card 1 has a controller 2. An input module 3 is connected to the controller 2. Fiber material reaches a licker-in 7 via a feed 6 and is transferred from the licker-in 7 to a drum 8 rotatable about a longitudinal axis 12. The drum 8 is driven by a drive 42 in an operating direction 11. Arranged above the drum 8 is a revolving flat unit 13. The revolving flat unit 13 is provided with schematically shown, rotating carding elements 14. A carding nip 20 is formed between an outer surface 10 of the drum and a plane 16 of the carding elements 14. The carding elements 14 are guided along the drum 8 by a flexible bend 29.Following the revolving flat unit 13, the carded fiber material reaches the area of ​​a rotatably mounted doffer 23, which removes the carded fiber material from the drum 8. Between a machine frame 22 and the flexible bend 29, an actuator 31 is provided, with which a distance between the plane 16 and the OBJ-3594P 10.03.2023 surface 10 can be adjusted. On the longitudinal axis 12, a structure-borne sound sensor 32 is shown, which is connected to a carding gap width measurement 33 containing an evaluation. The carding gap width measurement 33 is connected to the controller 2. In the area of ​​the carding gap 20, a process temperature measurement 34 is shown, which is also connected to the controller 2. Furthermore, the feed 6, the drive 42 and the actuator 31 are particularly connected to the controller 2.With the controller 2, the carding gap width 21 (see Figure 2) can be controlled via the actuator 31, the speed of the drum 8 can be controlled via the drive 42, and the amount of fiber material fed to the drum 8 can be controlled via the feed 6. In the illustrated embodiment, possible installation locations for measuring the drum temperature 37, the flexible sheet temperature 38, the machine frame temperature 39, the carding element temperature 40, and the ambient temperature 41 are shown. A connection of the measurements 37 to 41 to the controller 2 is not shown in Figure 5. The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are just as possible as a combination of the features, even if these are illustrated and described in different embodiments.

[0002] OBJ-3594P 10.03.2023 LIST OF REFERENCE SYMBOLS 1 Revolving flat card 2 Control system 3 Input module 4 Fiber material 5 Feed chute 6 Feed 7 Licker-in 8 Drum 9 Drum clothing 10 Surface of drum clothing 11 Operating direction of drum 12 Longitudinal axis 13 Revolving flat unit 14 Carding element 15 Flat clothing 16 Flat clothing plane 17 Chain 18 Deflection roller 19 Working direction 20 Carding gap 21 Carding gap width 22 Machine frame 23 Doffer 24 Doffer roller 25 Press roller pair 26 Fleece former 27 Calender roller pair 28 Card sliver 29 First flexible bend OBJ-3594P 10.03.2023 30 Second flexible bend 31 Actuator 32 Structure-borne sound sensor 33 Carding gap measurement 34 Process temperature measurement 35 Insulation 36 Current sensor 37 Drum temperature 38 Flexible sheet temperature 39 Machine frame temperature 40 Carding element temperature 41 Ambient temperature 42 Drum drive

Claims

OBJ-3594P 10.03.2023 CLAIMS 1. Method for operating a revolving flat card (1), wherein the revolving flat card (1) has a control system (2) with an input module (3) and a feed system (6) for supplying fiber material (4), a machine frame (22), a drum (8) equipped with a drum assembly (9) in the machine frame (22) and rotatably held about a longitudinal axis (12), and a revolving flat unit (13) having a plurality of carding elements (14), wherein the carding elements (14) each have a flat assembly (15) and are held on at least one flexible sheet (29, 30) on both sides of the drum (8) in the direction of the longitudinal axis (12),and wherein a carding gap (20) with a carding gap width (21) is formed between an outer surface (10) of the drum clothing (9) and a plane (16) of the flat clothings (15) facing the drum clothing (9), and the revolving flat card (1) has a carding gap width measurement (33) and an actuator (31) for adjusting the carding gap width (21) by adjusting the flexible sheets (29, 30) and a drive (42) for controlling a speed of the drum (8), characterized by the method steps - measuring a process temperature,wherein the process temperature corresponds to a temperature prevailing in the fiber material (4) in the carding gap (20); - a target process temperature and an associated maximum process temperature are detected by the input module (3); - a control range of the carding gap width (21) and a maximum value of the carding gap width (21) are detected by the input module (3); - the process temperature is regulated by the controller (2) by adjusting the carding gap width (21) and / or the feed (6) and / or the speed of the drum (8). OBJ-3594P March 10, 2023 2. Method according to claim 1, characterized in that the detection of the target process temperature and the associated maximum process temperature takes place by entering an identifier of the fiber material (4) in the input module (3).

3. Method according to claim 1 or 2, characterized in that the detection of the control range of the carding gap width (21) and a maximum value of the carding gap width (21) takes place by entering a quality specification in the input module (3).

4. Method according to claim 1 or 2, characterized in that the identifier of the fiber material (4) includes the control range of the carding gap width (21) and the maximum value of the carding gap width (21).

5. Method according to one or more of the preceding claims, characterized in that upon reaching the maximum value of the carding gap width (21) and the maximum process temperature, the feed (6) of fiber material (4) is reduced. 6.Method according to one or more of the preceding claims, characterized in that at least one of the following temperatures is measured and taken into account by the controller (2) as a correction factor in the regulation of the target process temperature: drum temperature (37), machine frame temperature (39), carding element temperature (40), flexible sheet temperature (38).

7. Method according to one or more of the preceding claims, characterized in that an ambient temperature (41) is measured and taken into account by the controller (2) as a correction factor in the regulation of the target process temperature. OBJ-3594P 10.03.2023 8. Method according to one or more of the preceding claims, characterized in that, viewed in the direction of the longitudinal axis (12), the temperatures are measured separately on both sides of the revolving flat card (1).

9. Method according to one or more of the preceding claims, characterized in that if the maximum value of the carding gap width (21) is not reached, the feed (6) of fiber material (4) is increased.

10. Method according to one or more of the preceding claims, characterized in that the control range comprises a single value,which corresponds to the maximum value of the carding gap width (20), and that the target process temperature is controlled via the feed (6) of fiber material (4).

11. A revolving flat card (1) for processing fiber material (4), comprising a control system (2) with an input module (3) and a feed (6) for feeding the fiber material (4), a machine frame (22), a drum (8) equipped with a drum assembly (9) in the machine frame (22) and rotatably mounted about a longitudinal axis (12), and a revolving flat unit (13) comprising a plurality of carding elements (14), wherein the carding elements (14) each comprise a flat assembly (15) and are held on at least one flexible sheet (29, 30) on both sides of the drum (8) in the direction of the longitudinal axis (12),and wherein a carding gap (20) with a carding gap width (21) is formed between an outer surface (10) of the drum clothing (9) and a plane (16) of the flat clothings (15) facing the drum clothing (9), and with a carding gap width measurement (33) and with an actuator (31) for adjusting the carding gap width (21) via an adjustment of the flexible, OBJ-3594P 10.03.2023 sheet (29, 30), and with a drive (42) for regulating a speed of the drum (8), characterized in that a process temperature measurement (34) is provided, wherein the process temperature corresponds to a temperature prevailing in the fiber material (4) in the carding gap (20), and that a detection of a target process temperature with an associated maximum process temperature is provided by the input module (3), and that a detection of a control range and a maximum value of the carding gap width (21) is provided by the input module (3), and that a control of the target process temperature by adjusting the carding gap width (21) and / or the feed (6) and / or the speed of the drum (8) is provided by the controller (2).

12. Revolving flat card (1) according to claim 11, characterized in that the input module (3) is designed as a keyboard or a reading device. 13.Revolving flat card (1) according to claim 11 or 12, characterized in that the input module (3) is equipped with remote access.

14. Revolving flat card (1) according to one or more of claims 11 to 13, characterized in that in the controller (2) corresponding data for a target process temperature and for a maximum process temperature are assigned to an identifier of the fiber material (4), and detection of the target process temperature and the associated maximum process temperature is provided by inputting an identifier of the fiber material (4).

15. Revolving flat card (1) according to one or more of claims 11 to 14, characterized in that in the controller (2) corresponding data for a control range and a quality specification. OBJ-3594P 10.03.2023 Maximum value of the carding gap width (21) are assigned and a detection of a control range and a maximum value of the carding gap width (21) is provided by the detection of the quality specification.

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