SPINNING FACILITY PREPARATION PLANT AND METHOD FOR DETECTING INTERFERENTIAL PARTICLES

Description

[0001] The invention relates to a spinning preparation plant and a method for detecting interfering particles, in particular trash parts, nits, shell nits, thick spots and / or foreign parts in a carded fiber nap.

[0002] According to current technology, it is known in the field of textile engineering to detect nits, contaminants, or dirt particles in a nonwoven fabric, fiber sliver, or yarn. The known methods differ in terms of the accuracy of the measured values ​​and the reliability in the daily operation of a spinning mill, as the components must function reliably under significant contamination and temperature stress. The detection of nits or fiber knots can be carried out in the spread fiber web or fiber sliver using various methods. More extensive measuring devices are necessary for detecting fiber slivers, as it is generally not possible to see inside the sliver from the outside. Consequently, it has become standard practice to perform the detection of nits or knots below or after the pickup.In this process, the absolute number of nits or knots is not counted, but only a portion of the fiber pile is detected and then the total production quantity is estimated based on a statistical analysis.

[0003] DE 19604499 B4 discloses a sensor for detecting nits and similar contaminants, which is arranged in a nonwoven guide profile and is movable back and forth across the working width of the carding machine. The concave surface of the nonwoven guide profile, which faces the discharge roller, has a wall that is at least partially transparent, through which the fibers are detected by a sensor. The nonwoven material removed by the take-off roller is guided continuously, but without contact, over this transparent wall, which leads to rapid contamination in practical operation, negatively impacting the measurement result. Short-term cleaning of the nonwoven guide element requires that the carding machine be completely switched off, i.e., that both the feed of fiber flakes be stopped and the rotational speed of the rotating components be set to zero. Only then can the nonwoven guide profile be cleaned.This interruption of the carding process is undesirable and reduces potential production output. Another disadvantage is the movable arrangement of the sensor within the nonwoven guide profile, which is very complex to manufacture and prone to malfunctions due to the cables dragged along during the process.

[0004] EP1057907 A1 discloses a spinning preparation plant with a cleaning or opening line and a subsequent carding machine. The carding machine has a sensor for detecting interfering particles, the sensor data being aggregated and evaluated in a control system.

[0005] WO99 / 50486 discloses a nonwoven guide element with a stationary integrated sensor that detects the fiber web on the take-off roller. For this purpose, the nonwoven guide element has a translucent window through which the sensor can detect the outer surface of the take-off roller.

[0006] Accordingly, the invention is based on the objective of designing a spinning preparation plant and a method in such a way that interfering particles, in particular trash parts, nits, shell nits, thick spots and / or foreign parts in a carded fiber nap can be detected in a short time.

[0007] The invention solves the stated problem by means of a spinning preparation plant and a method with the features specified in claims 1 and 8, respectively. Advantageous embodiments of the invention are defined in the dependent claims. The spinning preparation plant according to the invention comprises at least one cleaning or opening line with at least one controllable machine, e.g., a foreign matter separator, mixer, or cleaner, as well as at least two cards, each card having at least one sensor for detecting interfering particles, in particular trash particles, nits, shell nits, thick spots, and / or foreign matter in the carded fiber nap.

[0008] The invention is characterized in that the sensor data from the cards are aggregated and evaluated in a control unit, wherein at least one reference value for the fiber quality can be supplied to the control unit via an input module, and the control unit transmits at least one manipulated variable to a control unit of a machine in the cleaning and opening line. The machine in the cleaning and opening line can be, for example, a foreign matter separator, mixer, or cleaner. The transmitted manipulated variable can be, for example, the detection sensitivity of the foreign matter separator or the mixing ratio of different fibers in the mixer. By evaluating the data from the nonwoven guide element of a card in a control unit superior to the spinning preparation plant, the settings of individual machines in the spinning preparation plant can be influenced, thus creating a control loop.

[0009] Advantageously, the sensor data from at least two carding machines is summarized in a predetermined manner, for example, by summing, averaging, statistical analysis, classification, pattern analysis, or using artificial intelligence methods. Depending on the scope, an additional computer within the spinning preparation area can be used for this purpose, which can also communicate with the machines in the spinning preparation system that it controls. By summarizing the data from at least two carding machines, a larger amount of data can be collected in a shorter time than is possible with data from only one machine. The time required to evaluate fiber quality is significantly reduced. Here, too, a higher-level control system in the spinning preparation system uses statistical analysis to determine, for example, the nit number or to make a qualitative statement about the proportion of short fibers.By evaluating data from multiple carding machines, the number of measured values ​​increases, allowing the machine operator to receive a warning about defective production in a very short time, before the carded strip is processed in the next stage. Preferably, the control system is designed to display the aggregated and evaluated sensor data on a screen according to predefined criteria.

[0010] In a further embodiment, the higher-level control for summarizing and evaluating the data of the at least one card and for determining the control variables is integrated into the control of the machine to be controlled itself, wherein these individual data can be queried from the cards via corresponding data transmission channels from the cards or the nonwoven guiding elements according to the invention.

[0011] For this purpose, the control system is designed to output an optical, acoustic, or electrical signal in the event of a defective fiber layup, so that the next processing step, for example, drawing, combing, or the production of roving, is interrupted or does not even start. The inventive method for detecting interfering particles, in particular trash particles, nits, shell nits, thick spots, and / or foreign matter in a carded fiber layup, is carried out by means of sensors that detect the fiber layup in a nonwoven guide element facing the pickup of at least one card. The data from the sensors of the at least two cards are aggregated and evaluated in a control system of the spinning preparation plant and compared with a reference variable. The control system of the spinning preparation plant is designed to communicate with the control system of an upstream controllable machine.By capturing the interfering particles and jointly evaluating the data from several carding machines, a summed analysis of the data is performed, which can be based on various criteria. By appropriately selecting these criteria, it is possible to optimize the settings of at least one upstream controllable machine, resulting in improved quality of the carded strip. The controllable machine can be configured as a foreign matter separator, mixer, or cleaner. Controlling the foreign matter separator can increase or decrease the sensitivity of the particle removal rate, thus allowing production to be run with more or less waste. Controlling the mixer and / or cleaner can, for example, partially compensate for changes in the raw material due to altered mixing ratios or increased cleaning intensity.

[0012] A carding machine for use in the spinning preparation plant according to the invention comprises a device for detecting interfering particles, in particular trash particles, nits, shell nits, thick spots and / or foreign parts in a carded fiber web, wherein the device comprises at least one sensor which is fixedly arranged in a nonwoven guide element which is arranged in the transition from a take-up roller to a stripping roller, wherein the at least one sensor detects the fiber web on the take-up roller. Because the sensor detects the fiber web located in the teeth of the take-up roller assembly, there is less contamination of the area through which the sensor beams must penetrate. The fiber web thus only touches the approximately vertical front surface of the nonwoven guide element, which is therefore significantly less contaminated than the horizontal concave top surface.Due to this upright, nearly perpendicular orientation of the front surface relative to the sensor, fewer dirt particles accumulate on it during operation compared to conventional systems. The gap between the nonwoven guide element and the sensor is very narrow, so that the fiber pile partially touches the vertical front surface of the nonwoven guide element and is thus continuously cleaned by the constant material flow. This results in a longer service life before the nonwoven guide element, or any translucent element through which the sensor beams penetrate, needs cleaning. Instead of a single, movable sensor within the nonwoven guide element, at least one sensor is fixed in place. This eliminates the risk of malfunctions caused by broken trailing cables.

[0013] The nonwoven guide element has a front side facing the customer with at least one translucent element. This translucent element can be located only within the sensor's detection range, or alternatively, extend across the working width of the carding machine, for example, as a transparent wall on the front side of the nonwoven guide element.

[0014] By arranging at least three, preferably at least five, and particularly preferably at least nine sensors in a fixed position within the nonwoven guide element, the accuracy and evaluation time can be influenced by a larger amount of data. Depending on customer requirements, the number of sensors allows for a compromise between particle detection accuracy and device cost.

[0015] In a preferred embodiment, each sensor comprises a sensor board with an image acquisition sensor and a lens, wherein a computer, a mounting plate, and an illumination unit are arranged between the sensor board and the polarizing filter. This sensor design achieves the greatest possible distance between the sensor board and the fiber array, which in this small installation space would only be possible with a mirror to deflect the sensor beams.

[0016] The sensor's lens penetrates a plate containing the computer, the mounting plate, and the illumination unit. This implements a reversed sensor design, as known in the prior art, with the sensor positioned at the greatest possible distance from the object to be detected within this small installation space.

[0017] Preferably, the mounting plate is designed to protect the computer and the sensor board from electromagnetic radiation. This eliminates the need for separate encapsulation of the computer and the sensor board. For this purpose, the mounting plate is made of a metal, for example.

[0018] The computer is trained to analyze the image data from the image acquisition sensor using algorithms. The detected contaminants are classified and counted, or recorded in statistics. This classification can include not only the type of contaminant (nits, shell nits, trash particles, foreign matter) and its specific characteristics, but also other properties such as size, contour, structure, color, and surface texture. Furthermore, it is possible to determine characteristic values ​​of the fibers or fiber composite based on the image data, such as cloudiness, thin spots, thick spots, structure, fiber orientation, and short fiber content. This information can be used automatically by a higher-level control system to optimize, for example, carding machines or cleaning equipment—such as foreign matter separators—to reduce the contaminant content or optimize fiber characteristics.The nonwoven guide element according to the invention thus becomes the measuring element of a control loop for regulating or optimizing the operating parameters of the carding machine itself or the feeding machines. The machines thereby automatically adapt to changing raw materials or to altered boundary or processing conditions, so that a constant quality of the raw material for the carding machine is achieved.

[0019] Gathering the information needed to optimize the machines is time-consuming. Firstly, the calculation algorithms are time-intensive; secondly, determining the content of foreign particles requires evaluating significantly more individual images than is necessary for identifying, for example, nits, shell nits, or trash particles.

[0020] Preferably, each sensor of a nonwoven guide profile is assigned its own computer, which sums or summarizes the results of the individual sensors. The use of at least two sensors enables parallel acquisition and evaluation of the sensor data. By summarizing the results of all sensors within the nonwoven guide profile according to the invention, the impurity content or fiber properties can be determined significantly faster. The summarization of the sensor results is performed in a predetermined manner, e.g., by summation, averaging, statistical evaluation, classification, pattern analysis, or using artificial intelligence methods. Depending on the scope, an additional computer within the nonwoven guide profile can be used for this purpose, which can also handle communication between the nonwoven guide element and the carding machine or other machines in the spinning mill.

[0021] 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.

[0022] They show: Fig. 1 a schematic side view of a spinning preparation machine in the form of a carding machine; Fig. 2 an enlarged view of a built-in nonwoven guide element; Fig. 2a a detailed view of the nonwoven guide element; Fig. 3 a side view of the sensor in the nonwoven guide element; Fig. 4 a first embodiment of a sensor arrangement in a nonwoven guide element; Fig. 4a a second embodiment of a sensor arrangement in a nonwoven guide element; Fig. 5 a spinning preparation system with an arrangement of several cards with a device for summarizing and evaluating data.

[0023] Identical features in the drawing are each identified by the same reference symbol. It should be understood that the drawing is simplified and, in particular, not to scale.

[0024] Fig. 1Figure 1 shows a carding machine 100 in which fiber flakes are guided via a chute to a feeding roller 1, a feeding table 2, and several pre-tears 3a, 3b, 3c, to the drum 4 or the tambour. On the drum 4, the fibers of the fiber flakes are parallelized and cleaned by means of stationary carding elements 13, suction hoods, and reject knives, and by means of rotating carding elements arranged on a traveling cover system 17, which are designed as cover bars 14. The resulting fiber web 16 is subsequently conveyed via a take-up roller 5, a stripping roller 6, and several crushing rollers 7, 8 to a web guide 9, which forms the fiber web into a fiber ribbon with a web funnel 10. This ribbon is then transferred via take-up rollers 11, 12 to a downstream processing machine or a can 15.The adjustment of the cover bars 14 and the carding elements 13 to the drum 4 (carding gap) is carried out via sliding bars not shown here, which may have wedge-shaped elements aligned against each other.

[0025] In Figure 2 and 2aThe arrangement of the nonwoven guide element 20 between the take-up roller 5, the scraper roller 6, and a squeeze roller 7 is shown, in which the fiber web 16 is taken from the take-up roller 5 by the scraper roller 6 and guided along a concave upper surface 20c of the nonwoven guide element 20 to the web funnel 10. The nonwoven guide element 20 is essentially formed by four sides 20a, 20c, 20d, 20e, which enclose a cavity 20f. The front surface 20a has at least a partially translucent element 20b, which is designed to allow the detection area or field of view of a sensor 30 located in the cavity 20f to be directed onto the fiber web 16 in the assembly 5a of the take-up roller 5. The translucent element 20b can only be arranged in the area of ​​the viewing angle of a sensor 30, or extend as a continuous translucent element 20b at least partially or completely over the working width of the card 100.The front surface 20a of the nonwoven guide element 20 is thus aligned at a small distance from the surface of the receiver 5. The concave upper surface 20c of the nonwoven guide element 20 guides the fiber web 16 from the wiper roller 6 to the squeeze rollers 7, 8. The sensor 30 detects the fiber web 16, which is still located in the teeth of the receiver assembly 5a. The fiber web 16 thus passes over the nearly vertically oriented front surface 20a of the nonwoven guide element 20 and therefore also continuously over the translucent element 20b, which consequently becomes significantly less soiled than the horizontally oriented concave upper surface 20c. Soiling could accumulate on a translucent element located in the horizontally oriented concave upper surface 20c, which was not fully contacted by the fiber web 16. This results in a longer service life before the fleece guiding element 20 or the translucent element 20b needs to be cleaned.Within the nonwoven guide element 20, a single sensor 30 is no longer movable; instead, at least one sensor 30 is stationary. When several stationary sensors 30 are arranged within the nonwoven guide element, they are positioned at regular intervals. The translucent element 20b can be a glass or plastic disc, behind which a polarizing filter 31 is arranged. The polarizing filter 31 is thus positioned between the translucent element 20b and the sensor 30. The polarizing filter 31 is designed for circular polarization, which blocks the reflected rays of the sensor 30 that are reflected from a glossy surface, such as the metallic trim. However, the reflection of the rays from the matte fibers and interfering particles remains visible to the sensor 30.The sensor 30 thus detects only the fibers and any interfering particles contained within the fiber pile 16 and can identify thickened areas or knots, nits, shell nits, or foreign parts via image analysis. For this purpose, white light is generated, which, in combination with the polarizing filter, can be used to mask the fiber assembly 5a. Within the nonwoven guide element 20, the polarizing filter 31 is framed by a reference film 32, which allows for white balance adjustment. The representation of the sensor 30 in the figure... Figure 2a This is only a schematic representation. The structure of sensor 30 is shown in Figure 3 described in detail.

[0026] Integrating a cost-effective sensor for image processing requires a minimum distance between the sensor and the object being monitored. If this distance is not achievable due to limited installation space, deflecting mirrors are used, but this has the disadvantage of uncontrolled contamination and necessitates precise mirror adjustment. For this reason, the sensor 30 used here has been reconfigured and originates from a carrier plate 33, to which the other components are attached at a distance. The carrier plate 33 is fixedly positioned within the nonwoven guide element 20, for example, at unspecified steps or grooves on the top surface 20c and bottom surface 20e. Extending from the carrier plate 33 to the translucent element 20b is a lighting unit 34, which can be designed as an LED board.The illumination unit 34 is also designed as a plate-shaped component on which the LEDs or other light elements are arranged. The LEDs can optionally be combined with additional lenses or lens arrays not shown here. The illumination unit 34 is arranged parallel to the carrier plate 33. Behind the carrier plate 33, a computer 35 is arranged on a plate, which can immediately evaluate the acquired data. The configuration of each sensor 30 with its own computer 35 enables parallel processing of the acquired data, so that the determined values ​​are available more quickly. The sensor board 36 is arranged behind the plate with the computer 35, extending from the carrier plate 33, thus achieving the maximum distance in this installation space to the fibers to be detected. The sensor board 36 can, for example, be designed as a CCD or CMOS sensor with which individual images can be acquired.

[0027] To enable the sensor board 36 to be arranged with a lens 37 in this small installation space, the computer plate 35, the support plate 33, and the illumination unit 34 each have an opening (not further specified) aligned in a single plane, through which the lens 37 protrudes. All components (34, 35, 36) are aligned parallel to the support plate 33 and attached to it by means of bolts or spacers. Because the lens 37 penetrates the computer plate 35, the support plate 33, and the illumination unit 34, the sensor board 36 can be positioned in this installation space at a maximum distance from the fibers to be detected without the use of a mirror. Advantageously, the support plate 33 is designed to protect the computer 35 and the sensor board 36 from excessively high levels of electromagnetic radiation.During image capture, the lighting unit 34 will operate briefly in flash mode with a very high current, thereby shielding the resulting electromagnetic radiation from the computer 35 and the sensor board 36 by, for example, a metallic carrier plate 33.

[0028] In Figure 4Within the nonwoven guide element 20, for example, five sensors 30 are preferably evenly distributed at intervals a across the working width A of the carding machine. With a drum width 4 of, for example, 1280 mm, this results in a working width A of approximately 1180 mm, which is detected by five sensors, each with a detection width of 20 to 30 mm. In the evaluation of the carding machine's control system, this results in a separate track being detected for each sensor. With stationary sensors 30, a minimum of three sensors 30 within the nonwoven guide profile 20 has proven advantageous for a drum width 4 of 1000 mm, enabling a sufficiently accurate determination of the nit count. Considering the cost of the sensors 30 and the width of the drum 4, an arrangement of five sensors 30 has proven optimal, allowing for a very high accuracy determination of the nit count.The five sensors 30 are preferably arranged at equal intervals a across the working width A of the carding machine within the nonwoven guide element 20. To detect the nits, approximately 10,000 images must be acquired and evaluated by the sensors for each measurement. For example, in a carding production of 80 kg / h, a measurement is defined as a 100-meter length of fiber fleece 16 passing through the take-up unit 5, from which approximately 10,000 images are acquired. In the case of an uneven width distribution, an average nit count can be determined from the number of tracks, in this case using five sensors 30, with an error of 3%. When using only three sensors 30, the error of the average nit count increases to 12%. When using nine sensors ( Figure 4aBy using sensors 30 arranged at a distance b from each other, the error of the mean nit measurement is reduced to 1%. Using a large number of sensors 30 not only increases the accuracy in determining the nits but also reduces the time required to determine the measurement, as more images are captured simultaneously and processed in parallel by the computers 35. For example, the measurement time is approximately 40 seconds with three sensors 30, approximately 30 seconds with five sensors 30, and approximately 15 seconds with nine sensors 30. Due to the limited installation space within the nonwoven guide element 20 with a drum width of 1000 mm to 1500 mm, the arrangement of three to nine stationary sensors for determining the nits has proven to be optimal.Firstly, the working width A provides sufficient installation space for the distribution of the sensors 30, secondly, sufficient accuracy is ensured in combination with a measuring speed, and finally, the costs remain within an affordable range.

[0029] Even though this embodiment only shows a uniform distance a, b between the sensors 30, this distance can also be uneven. In that case, the data evaluation algorithm may need to be adjusted. It is therefore advantageous to arrange the sensors 30 at a greater or lesser distance from the center of the fiber pile 16, since the detection of certain nits, thick spots, or foreign particles may occur more frequently in the edge area (due to lateral flight) or in the center of the fiber pile 16 (due to differences in carding gap across the drum width) due to the specific carding drum design.

[0030] If the sensors 30 are also to be used to detect foreign matter, all sensors 30 together must acquire approximately 25,000,000 images. Therefore, when using five sensors 30 in a nonwoven guide element 20, each sensor must generate 5,000,000 images before a reliable determination of the presence of foreign matter is possible. A corresponding amount of fiber mat must be detected, which extends the measurement and evaluation process to approximately 18 hours. Using nine sensors 30 results in a measurement and evaluation time of still 10 hours, meaning that carding production is at least in the processing stage of a roving and must be discarded if a serious defect occurs.

[0031] To shorten this process, the invention proposes to combine and jointly evaluate the data from the sensors 30 from the nonwoven guide elements 20 of at least one card 100 in a controller 43. Figure 5Figure 40 shows a bale opener that opens a batch of fiber bales and feeds individual fiber flakes to a cleaning unit 41. Inside the cleaning unit 41, the fiber flakes are broken down, the fibers undergo initial cleaning and mixing, and foreign matter (plastic, packaging material, stems, metal, etc.) is removed by a foreign matter separator 42. The fiber flakes are then fed to the carding machines 100 via fiber transport lines (not shown). A higher-level control unit 43 sums up the individual data from the sensors 30 in the nonwoven guide elements 20 of the individual carding machines 100 and evaluates them according to various criteria. The evaluation can relate to the proportion of short fibers, foreign matter, the number of nits or knots, or characteristic values ​​such as cloudiness, thin / thick areas, or fiber orientation. A display is provided to show different fiber types, as well as, for example, foreign matter, nits, or dirt particles.A predefined waste quantity or rejection rate can be entered via an input module 44, allowing the data to be optimized within the control unit 43. The control unit 43 transmits the new specifications with the optimized data to the control unit 42a of the foreign matter separator 42, which can then be adjusted to be finer or coarser depending on the quality requirements and the starting material. The aim is to optimize the setting so that the required quality of the starting material (fiber fleece) for the carding machine is achieved and maintained. However, the sensitivity setting of the foreign matter separator 42 must not be set so high that an unnecessarily large amount of waste is generated without any benefit.For this purpose, it is necessary to modify only the sensitivity setting parameters required to detect precisely those foreign particles that are currently still being detected by the sensors 30 in the nonwoven guide elements 20 after the foreign particle separator 42 in the carding machine. This is achieved by the fact that the data compiled by the controller 43 includes not only the number of foreign particles but also their properties such as color, size, contour, structure, type, or surface finish. The controller 42a of the foreign particle separator 42 can then selectively optimize the required parameters. For example, if the controller 43 detects many red foreign particles but hardly any green ones, the sensitivity parameters for the detection of the color red will be optimized in the controller 42a, while the parameter for the color green will remain unchanged or, if necessary, be adjusted.It can even be operated with a less sensitive setting so that the overall elimination rate and thus the total amount of waste remains within the target values.

[0032] The aggregation of data from sensors 30 on the nonwoven guide elements of several cards 100 in the controller 43 shortens the time required to acquire the necessary number of images and reduces the time required to process the data. As a result, defects in the fiber web can be detected via foreign matter detection after 3 hours with 3 sensors per nonwoven guide element and card, after 2 hours with 5 sensors per nonwoven guide element and card, and after 1 hour with 9 sensors per nonwoven guide element and card. This allows potentially defective carding to be stopped at an early stage, before further processing begins in the downstream spinning mill.

[0033] The aggregation of data from sensors 30 of the nonwoven guide elements 20 from at least two carding machines in the control unit 43 offers a further advantage. If the control unit 43 detects that the data from the nonwoven guide elements 20 change simultaneously or in the same way in all carding machines, it can be assumed that this has a common cause, such as a change in the raw material, a change in one or more machines or cleaning lines, or a common change in processing conditions such as temperature or humidity in the spinning preparation area. If, on the other hand, the change is observed in only one carding machine, the cause is more likely to be found in the carding machine itself. The comparison of data from at least two carding machines in the control unit 43 can therefore serve to determine more precisely which machine needs to be adjusted to achieve the desired quality. Reference sign

[0034] 100 cards 1feed roller 2feed table 3a, 3b, 3clicker-in 4drum 5doffer 5aset 6squeegee roller 7, 8squeezing roller 9fleece guide element 10pile funnel 11, 12take-off rollers 13carding element 14lid bar 15can 16fiber pile 17moving lid system 20 Fleece guiding element 20a Front 20b Element 20c Top 20d Back 20e Bottom 20f Cavity 30 Sensor 31 Polarizing filter 32 Reference film 33 Carrier plate 34 Illumination unit 35 Computer 36 Sensor board 37 Lens 40 Bale opener 41 Cleaning line 42 Foreign part separator 42a Control unit 43 Control unit 44 Input module AWorking width aDistance bDistance

Claims

1. A spinning mill preparation, comprising at least one blow room (41) or opening line with at least one controllable machine, as well as at least two cards (100), wherein the respective card (100) includes at least one sensor (30) for capturing interfering particles, in particular trash parts, neps, shell neps, thick spots and / or foreign parts in the carded fibre web (16), characterized in that the sensor data are combined and evaluated in a control (43), wherein at least one reference variable for the fibre quality can be input to the control (43) via an input module (44), and the control (43) transmits a modified variable to the control (42a) of the controllable machine.

2.

2. The spinning mill preparation according to claim 1, characterized in that the controllable machine is formed as a foreign parts separator (42) or a blender or a cleaner.

3. The spinning mill preparation according to claim 1, characterized in that the control (43) is formed for issuing a visual, acoustic or electric signal for faulty fibre web.

4. The spinning mill preparation according to any of claims 1 to 3, characterized in that the cards (100) each comprise a device for recognizing interfering particles, in particular trash parts, neps, shell neps, thick spots and / or foreign parts in a carded fibre web (16), wherein the device comprises at least three sensors (30), preferably at least five sensors (30), particularly preferred at least nine sensors (30), which are stationarily disposed within a web guiding element (20), which is disposed at the transition from a doffer (5) to a stripper roll (6), wherein the sensors (30) detect the fibre web (16) on the doffer (5), wherein the web guiding element (20) has a front side (20a), which is disposed towards the doffer (5), with at least one light-transmissible element (20b).

5. The spinning mill preparation according to any of claims 1 to 4, characterized in that each sensor (30) includes a sensor board (36) with a lens (37), wherein a computer, a carrier board (33) and an illumination unit (34) are disposed between the sensor board (36) and the polarizing filter (31).

6. The spinning mill preparation according to claim 5, characterized in that the lens (37) penetrates a board with the computer (35), the carrier board (33) and the illumination unit (34).

7. The spinning mill preparation according to claim 5 or 6, characterized in that the carrier board (33) is formed for protecting the computer (35) and the sensor board (36) from electromagnetic radiation.

8. A method of capturing interfering particles, in particular trash parts, neps, shell neps, thick spots and / or foreign parts in a carded fibre web by means of sensors (30), wherein the data of the sensors (30) of the cards are combined and evaluated in a control (43) of the spinning mill preparation according to any of claims 1 to 7 and compared to a reference variable, wherein the control (43) is formed for communicating with the control (42a) of an upstream controllable machine (42).

9. The method according to claim 8, characterized in that the controllable machine is formed as a foreign parts separator (42) or a blender or a cleaner.