Combing machine with simplified design

Abstract

The present invention relates to a combing machine (K) with several combing heads (1), wherein the combing heads (1) each have a gripper apparatus (2) through which a cotton strip (Wb) provided by a cotton roll (W) can be guided, further comprising a fixed (5) and a round comb (4) for combing out combed pieces from the cotton strip (Wb), a pair of tear-off rollers (6) for tearing off a fiber beard from the cotton strip (Wb) and for soldering the fiber beard to a fiber nap (Ff), wherein each combing head (1) is followed in the material flow direction by a take-off table (11), means for consolidating the fiber nap (Ff) into a nonwoven (V), and a belt funnel (41) for forming the nonwoven (V) into a fiber strip (F1 - F8). The invention is characterized in that each comb head (1) has a single pair of tear-off rollers (6), and that the take-off table (11) has a first rising section (12) onto which the fiber web (Ff) formed by the single pair of tear-off rollers (6) is guided to a continuously rotating pair of take-off rollers (8).

Description

[0001] The present invention relates to a combing machine with several combing heads, each combing head having a gripping device through which a cotton strip, supplied by a cotton roll, can be guided. Each combing head further comprises a fixed and a round comb for combing out combed fibers from the cotton strip, a pair of tear-off rollers for tearing off a fiber strand from the cotton strip and for soldering the fiber strand to a fiber web. Downstream of each combing head, in the direction of material flow, are a take-off table, means for consolidating the fiber web into a nonwoven, and a belt funnel for forming the nonwoven into a fiber strip.

[0002] The combing process using a combing machine comprises, in a known manner, the tearing of a fiber strand from a wadding strip or fiber strips at each combing head. This is followed by a combing process to remove the fiber strand, which ends at one end, and a subsequent so-called soldering process. In this process, the combed-out fiber strands, with lengths dependent on the stack, are overlapped like roof tiles in the direction of material flow in front of the tear-off rollers, creating an initially flat, continuous fiber pile. The wadding strips or fiber strips processed by the combing machine can include, for example, natural fibers such as cotton, cellulose, hemp, and the like, synthetic fibers, and blends of natural and synthetic fibers.

[0003] The fiber web typically exhibits a wavy structure with periodic irregularities, potentially resulting in soldering defects, thin spots, and other flaws. These defects are partially compensated for in subsequent processing steps on the combing machine. These steps may involve the eccentric take-off of the web from the take-off table and / or the doubling of several individual combing head bands into a single fiber band at a defined position, thus homogenizing the fiber band exiting the combing machine.

[0004] Furthermore, the machine operator can minimize the wavy structure during fiber pile formation by making optimal, material-specific settings. For example, the overlap length of the fiber strands can be adjusted depending on the fiber length. The fiber strands are laid on top of each other in such a way that the unevenness caused by the solder joints partially cancels each other out. Crucial to this is precise coordination between the tear-off point and the point at which the fiber strand protruding from the gripper reaches the clamping line of the first pair of tear-off rollers.

[0005] The take-off table following the tear-off rollers at each comb head ensures that the fiber web, which is fed out during the piling motion, can be continuously removed. The take-off table acts as a stabilizing zone and is crucial for the uniformity of the fiber web. Following the take-off table is typically a pair of take-off rollers, which consolidate the fiber web into the nonwoven fabric. The formation of individual fiber ribbons is achieved by means of a subsequent belt funnel.

[0006] The primary function of the tear-off roller pairs in nonwoven fabric formation is to separate a fiber strand from the winding wadding, transport the fiber strand through the fixed comb, solder it to the mat, and then consolidate it in the combing machine, which is usually accomplished by two pairs of tear-off rollers. The first pair of tear-off rollers performs more functions than the second pair, as it grips the fiber strand protruding from the gripper, tears it off, pulls the rear end of the strand through the fixed comb, and overlaps and solders the fiber strands.

[0007] Therefore, the essential functions of the tear-off roller pairs are taken over by the first pair and are essentially completed when the nonwoven reaches the second pair. The second pair of tear-off rollers typically performs a synchronous movement with the first, resulting in further compression of the fiber web. This rotational movement of both pairs of tear-off rollers is known as the "pilgrim step" motion and, due to the large periodic reversal accelerations, is very energy-intensive during operation, leading to increased wear of the gearbox and drives.

[0008] The use of two pairs of tear-off rollers offers advantages, particularly regarding nonwoven quality. This allows for the production of a more stable nonwoven fabric while avoiding distortion, resulting in improved nonwoven uniformity and, due to the greater stability of the fabric, higher production output with a higher number of comb cycles on the combing machine. Insufficient nonwoven consolidation often leads to a hairy nonwoven, which should be avoided and also complicates further processing.

[0009] From WO 2020 / 208454 A1, a combing machine is known with a combing head comprising a circular comb and a gripper assembly through which a nonwoven fabric, which can be supplied from a reel, can be guided and combed out with the circular comb. It is stated that at least one pair of tear-off rollers is provided, but it is not specified by what subsequent means the nonwoven fabric, which passes through the at least one pair of tear-off rollers, is further processed.

[0010] From EP 1 774 073 B1, a combing machine with a combing head is known, comprising a circular comb and a gripper assembly through which a nonwoven fabric, supplied from a reel, can be guided and combed with the circular comb. A pair of tear-off rollers following the gripper assembly and a pair of guide rollers following the tear-off rollers are shown. It is also stated that once the tear-off or soldering process is complete, the gripper assembly is moved back to a rear position in which it is closed, presenting the fiber tail protruding from the gripper to a comb segment of the circular comb for combing. Before the gripper assembly returns to its forward position, the take-off rollers and the guide rollers perform a reversing movement, thereby retracting the rear end of the fiber nonwoven fabric by a certain amount. This is necessary to achieve the required overlap for the soldering process.Unfortunately, both pairs of tear-off rollers are subjected to high accelerations by the pilgrim stepping motion, resulting in a considerable energy demand and causing the drive and the pairs of tear-off rollers to be subject to heavy wear.

[0011] EP 1 774 072 B1 describes an alternative solution without the use of a tear-off roller pair, proposing that the device consists of a circulating means which is provided on its periphery around its circumference with openings for an air passage and at least a part of the interior of the means is connected to a negative pressure source and wherein a casing is provided which forms a space sealed off from the environment between the extraction device and the periphery of the circulating means, wherein a part of the sealed space is formed by the periphery of the means and by the extraction device, whereby high accelerations of a pilgrim stepping motion are avoided, but results in greater structural complexity.

[0012] The object of the present invention is to further develop a combing machine in such a way that, while maintaining a required ribbon quality of the fiber ribbon resulting from the nonwoven fabric, the combing machine can be operated as energy-efficiently and with minimal wear as possible.

[0013] This problem is solved, starting from a combing machine of the type mentioned above, by providing each combing head with a single pair of tear-off rollers, and by providing the take-off table with a first rising section onto which the fiber web formed by the single pair of tear-off rollers is guided to a continuously rotating pair of take-off rollers. Advantageous embodiments of the invention are specified in the dependent claims.

[0014] Each combing head has exactly one pair of stripping rollers into which the combed-out fiber fuzz from the gripping apparatus is fed, soldered, and compacted. A take-off table is located downstream of each pair of stripping rollers on each combing head, where the fiber fuzz is guided or deposited.

[0015] This makes it possible to reduce the first and second pairs of tear-off rollers, which are generally known in the prior art to be arranged one after the other in the direction of movement of the nonwoven fabric, to just a single pair of tear-off rollers per combing head. This achieves the advantage that the mass to be accelerated by the piling motion is limited to the upper and lower rollers of the single pair of tear-off rollers. This reduces the machine and operating costs of the combing machine, and results in less wear, since, for example, a gearbox for driving only one pair of tear-off rollers can be designed more simply than for two pairs. The overlap of the fiber strands occurs between the gripper unit and the pair of tear-off rollers. The nonwoven fabric is consolidated in the clamping line of the single pair of tear-off rollers and then guided from the pair of tear-off rollers to the take-off table.The take-off table serves as a settling zone for the fiber web exiting the single pair of tear-off rollers. The take-off table has a first rising section onto which the fiber web formed by the single pair of tear-off rollers is guided to a continuously rotating pair of take-off rollers. It has been advantageously shown that this first rising section forms an impact surface, i.e., serves as an impact element against which the web is guided. The function of the second pair of tear-off rollers can thus be taken over by subsequent components of the combing machine, which follow the first pair of tear-off rollers and involve rollers or other components that do not perform the stepping motion with its known high rotational accelerations.

[0016] Each pair of tear-off rollers preferably has only one driven lower roller and one non-driven, rotating upper roller. The fiber strip from the gripper apparatus is soldered onto the fiber web returned by the pair of tear-off rollers and transported towards the take-off table.

[0017] After the take-off table, the function of the saved second pair of tear-off rollers can be replaced by continuously rotating pairs of rollers, whereby alternative possibilities for further pressing and post-treatment of the fiber web are also possible in order to achieve a required nonwoven quality, as can also be achieved with two pairs of tear-off rollers arranged directly behind one another, each of which must perform the pilgrim step movement.

[0018] The single pair of tear-off rollers produces a more delicate fiber web than if a second pair of tear-off rollers were to follow the first pair.

[0019] Advantageously, a pressure control device can be used to precisely control the pressure of the upper roll against the lower roll of one of the tear-off roll pairs, thus improving the compression of the fiber beards. This, in turn, improves the quality of the subsequent nonwoven fabric. A pressure control device can be provided that allows the contact pressure of the upper roll against the lower roll of the tear-off roll pair to be adjusted and / or even regulated. For example, a detection device can be incorporated to monitor the nonwoven fabric quality, and a control device can be provided that forms an active control loop with the detection device and the pressure control device, ensuring the nonwoven fabric quality by applying the appropriate contact pressure.

[0020] Another additional or alternative option is for the upper and / or lower rollers of the tear-off roller pair to have a surface coating or covering. This coating or covering can be more flexible than metal or plastic, so the surface of the upper and / or lower rollers, in particular, can be rubberized. The rubber coating can be selected to be relatively hard, allowing a high pressure to be exerted on the nonwoven fabric with just one pair of tear-off rollers; for example, the rubber coating can have a hardness of 60 to 90 Shore A.

[0021] A further advantage is that, viewed in the direction of fiber movement, at least one pair of take-off rollers follows the arrangement of the take-off table. Here, too, a pressure control device can be provided, allowing the two take-off rollers to be pressed against each other in an adjustable and, in particular, controllable manner, in order to achieve a corresponding effect on the fiber web as it passes between the take-off rollers and is compacted into a web. Thus, the combing machine can have at least two pressure control devices, the first being connected to the pair of tear-off rollers, and the second being connected, for example, to the pair of take-off rollers.

[0022] Furthermore, in the direction of movement of the nonwoven fabric, at least one table calender roller pair can follow the arrangement of the take-off roller pair, whereby the contact pressure between the two rollers of the table calender roller pair can also be designed to be adjustable. The adjustability can, for example, be manual, and a pressure control device can also be provided in conjunction with the table calender roller pair.

[0023] The table calender rolls can be arranged in pairs so that they form a specific angle with the tape feeder. For example, the table calender roll pair can be aligned so that the fiber tape undergoes at least one, or preferably two, 90° deflections. Of course, it is also conceivable that the table calender roll pair is arranged so that the resulting fiber tape can enter the tape feeder between the rolls of the table calender roll pair and the tape feeder without deflection, whereby one or more deflections of the fiber tape can have a smoothing effect on the tape. Depending on the positioning of the tape feeder, the nonwoven fabric is deflected between the output roll pair. Any arrangement between 0° and 90° is conceivable, both with regard to the positioning of the tape feeder relative to the take-off rolls and the positioning of the table calender rolls relative to the tape feeder.

[0024] It is also conceivable that, viewed in the direction of movement of the nonwoven fabric, at least one parallel belt system follows the arrangement of the take-off roller pair, whereby the nonwoven fabric can be guided between an upper belt and a lower belt. The two upper and lower belts can be pressed together with a defined pressure, so that the nonwoven fabric is not only compressed in line contact between two rotating rollers, but especially via surface contact between the two upper and lower belts.

[0025] A space formed in the take-off table for guiding the fiber web is generally defined on the underside by a first section, which serves as an impact element, and on the upper side by a cover. According to a further embodiment, the first section and / or the cover can be inclined relative to an infeed direction of the nonwoven fabric. In operation of the combing head, the infeed direction of the fiber web is defined, for example, by a horizontal line. The take-off table also has an inclination to the horizontal and can point diagonally upwards, so that the fiber web initially enters the take-off table horizontally and, upon contact with the first section, rises against gravity, forming a wave.

[0026] By geometrically optimizing the take-off table, particularly with regard to the inclination of the first section and / or the cover, the fiber web entering the take-off table from the single pair of tear-off rollers can be conveyed gently and efficiently until it is compacted into a web by the take-off rollers. The wave formation of the moving fiber web within the take-off table has a significant impact on the web quality, and this wave formation can be minimized by adjusting the inclination of the cover and / or the first section relative to the infeed direction from the tear-off roller pair. A homogeneous wave is essential for a good, uniform web.

[0027] The inclination of the first section and the cover can be set to the same angle. They can also have different inclinations, creating, for example, constrictions or widenings that deliberately shape the wave. In addition to changing the inclination of the cover and / or the first section, the distance between the cover and the first section can also be altered, so that the resulting channel can limit the wave's height.

[0028] The wave pattern can be influenced, in particular, by shifting the upper cover parallel to the first section, whereby the fiber strand from the tear-off roller pair initially comes into contact with the first section. The resulting fiber strand then forms a wave and subsequently comes into contact with the cover. Optimizing the distance between the first section and the cover can therefore also optimize the wave pattern of the fiber strand. An adjustment range of 10–25 mm can be technologically advantageous.

[0029] Various geometries are conceivable for the cover, for example flat straight covers or circular or curved covers.

[0030] Regardless of the tilt setting of the first section, its position relative to the cleat of the tear-off roller pair remains unchanged, thus constituting a fixed pivot point. Changes in tilt are compensated for, for example, by a second pivot point on the first section and by a change in length between the first and second sections. The adjustment angle when setting the tilt of the first section and the cover can be, for example, + / - 20 degrees.

[0031] The surface of the take-off table is preferably designed in such a way that the fiber pile can be guided with low friction and no fiber adhesion occurs.

[0032] On the path of the nonwoven fabric after exiting the last element of the take-off roller pair and / or before entering the table calender roller pair, at least one nonwoven guide element can be installed, which, in contact with the nonwoven fabric, can generate movement within the fabric. This minimizes or avoids unfavorable friction areas between the nonwoven fabric and other guide elements, particularly if the guide element can be actively operated, for example, when the nonwoven material is deflected towards a belt feeder. Furthermore, weak areas within the nonwoven fabric, such as its edges, can be stabilized by guide elements.

[0033] Furthermore, in addition to the arrangement of the take-off rollers and / or the table calender roller pair, at least one additional roller pair can be provided to further process the web as a replacement for the second take-off roller pair, in particular to compact or press it. This additional roller pair can be arranged between the take-off roller pair and the table calender roller pair, or even following the table calender roller pair. However, no additional roller pair is arranged between the single take-off roller pair and the subsequent take-off table.

[0034] 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: Fig. 1 A schematic view of a combing machine, here with eight comb heads as an example, Fig. 2 a partial representation of a comb head of a combing machine according to the state of the art, Fig. 3 a schematic view of a combing head of a combing machine according to an embodiment of the invention, wherein the respective combing head has exactly a single pair of tear-off rollers, Fig. 4 the representation according to Fig. 3 with an additional pair of rollers, Fig. 5 the representation according to Fig. 3 with a parallel belt system arranged after the take-off roller pair, Fig. 6 a schematic representation of a first embodiment of a modified extraction table, Fig. 7 a schematic representation of a second embodiment of a modified extraction table, Fig. 8 a schematic representation of a third embodiment of a modified extraction table, Fig. 9 a schematic representation of a fourth embodiment of a modified extraction table, Fig. 10 a schematic view of a passive nonwoven guide element, Fig. 11 a schematic view of an active nonwoven guide element with an end-side belt funnel, and Fig. 12 a schematic view of two active nonwoven guide elements with a belt funnel arranged between them.

[0035] The in Fig. The combing machine K shown in Figure 1 has, by way of example, eight combing heads 1, each of which, according to the prior art, is provided with two pairs of tear-off rollers. Each combing head 1 is fed by a wadding roll W with a width of, for example, 300 mm. Each wadding roll W has a length of approximately 300 m of wadding strip Wb. The combing heads 1 each produce a combed fiber fleece from the combed wadding strip Wb, which is consolidated into a nonwoven fabric V and each is combined by a belt funnel 41 into a combed fiber strip F1 to F8. The belt funnels 41 can be designed as measuring funnels through which the initial strip mass at each combing head 1 can be determined. Of the components shown in the Fig. Of the eight fiber strips shown here as an example, only those from the two outermost combing heads 1 are designated F1 and F8 for clarity. Fiber strips F1 to F8 enter the discharge table 28 and pass through a drafting unit 40 to a further belt hopper 42, which combines all fiber strips F1 to F8 into a single fiber strip F, which can also be called the combed strip, and deposits it in a container 43. The belt hopper 42 can be designed as a measuring hopper through which the initial strip mass is determined at the combing machine K. Alternatively, a stepped roller with an associated sensor for determining the strip mass can be arranged after the belt hopper 42.

[0036] The in Fig. The part of the combing head 1 of the combing machine K shown in Figure 2 is one of typically eight combing heads, each fed by a cotton coil W or at least one fiber tape. This embodiment describes the prior art and, for clarity, is shown and described using only one of the combing heads 1, with the details shown being installed on each of these combing heads 1 except for the common drive units and the tape storage. The combing head 1 includes (not shown) feeding devices for interconnected fibers, for example, a cotton coil W or, alternatively, at least one fiber tape fed from a can.

[0037] The interconnected fibers are transferred to a feed cylinder 3 of a gripper assembly 2. The gripper assembly 2 can be moved back and forth via levers and driven by a shaft connected to a gearbox. In the illustrated example, the gripper assembly 2 is in a closed position and the circular comb is active. During the transfer or soldering process, the gripper assembly 2 is in a forward position relative to the first pair of tear-off rollers and is open. A circular comb 4 is rotatably mounted below the gripper assembly 2. Its comb segment combs out the fiber bundle presented by the closed gripper. The circular comb 4 is also driven by a gearbox. A ratchet wheel (not shown) is mounted on the feed cylinder 3. The ratchet wheel is rotated incrementally by the back-and-forth movement of the gripper assembly 2 via a pawl (also not shown), thereby feeding the fibers to the gripper jaws for combing.The fibers are fed via the feed cylinder 3 to the gripper jaws of the gripper unit 2 for combing and then discharged to the front tear-off rollers 6. The beginning of the fiber strand is combed out by the circular comb 4. During the tearing and transport of the soldered fiber web, the end of the fiber strand is combed out by the fixed comb 5. The soldered fiber web is transported by the tear-off rollers 6 and 7 into the take-off table 11.

[0038] The fiber web is transported by means of a pair of take-up rollers 8 through a take-up table 11 and further consolidated into a web. Following the take-up rollers 8, the web is gathered into a fiber ribbon F1 and fed, together with the fiber ribbons F2-F8 also formed at the other comb heads 1, to a drafting unit 40, as shown in the Fig. 1 shown.

[0039] The take-off table 11 can have a first and a second section 12, 13, which are preferably arranged at an angle to each other. The sections 12, 13 can be sheet metal parts or a single, continuous sheet metal part. In this embodiment, the first section 12 rises upwards from the rear tear-off rollers 7 and, together with a cover 9, which can be another sheet metal part, forms a channel 10 from which the soldered fiber strands are pulled off as fiber mat (not shown). The longer second section 13 is inclined slightly downwards towards the take-off rollers 8, over which the fiber mat is pulled off in the pull-off direction A. The take-off table 11 is bounded laterally by a side guide 14 on each side, which guides the fiber mat. A channel (not shown) is preferably arranged below the take-off table 11, which can be connected to the suction system below the combing head, so that a slight negative pressure is present here.

[0040] Fig. Figure 3 schematically shows a combing head 1 of the combing machine K according to one embodiment of the invention. The combing machine K can have a plurality of combing heads 1 in a manner known per se, for example six, eight, or twelve, wherein the combing machine K can fundamentally have between four and sixteen or more combing heads 1. A cotton strip Wb is supplied to the respective combing head 1 via a respective cotton roll W, which is combed out step by step by means of a round comb 4.

[0041] In contrast to the prior art, only a single pair of tear-off rollers 6 picks up the combed-out fiber strand and solders it to the already generated further fiber pile Ff. The overlap of the fiber strands occurs between the gripper unit 2 and the single pair of tear-off rollers 6, whereby the resulting fiber pile Ff is consolidated for the first time in the clamping line of the pair of tear-off rollers 6. In this embodiment, the single pair of tear-off rollers 6 is also referred to as the front pair of tear-off rollers, since it has the same position relative to the gripper unit 2 and also performs the same function as in the prior art. The rear pair of tear-off rollers 7 is deliberately omitted, and the take-off table 11 is arranged closer to the front pair of tear-off rollers 6.The channel 10 of the take-off table 11 connects to the arrangement of the single pair of tear-off rollers 6. The fiber web Ff is gently fed into this channel and can form a wave that is bounded by the cover 9. The take-off table 11 calms and homogenizes the fiber web Ff, which is produced discontinuously in the pilger step process. The first section 12 of the take-off table 11 is responsible for the quality of the resulting fiber web Ff. This first section 12 acts as an impact edge against which the fiber web Ff strikes. This first section 12 has a maximum angle α ≤ 70 degrees to the horizontal. If the angle α becomes larger, and thus the first section 12 steeper, the fiber web Ff can accumulate and is not pushed upwards over the first section 12. The cover 9 positioned above it limits the wave in the fiber web Ff.The geometric design of the take-off table 11 allows at least part of the function of the second pair of tear-off rollers 7 to be compensated for without further compaction of the superimposed fiber strands. Finally, the fiber strand Ff runs from the take-off table 11 into a pair of take-off rollers 8, followed by the belt funnel 41 to form the fiber ribbon F8.

[0042] The illustration further shows a first pressure control device 20 in conjunction with the single tear-off roller pair 6 and a further pressure control device 21 in conjunction with the take-off rollers 8. The pressure control device 20 enables an adjustable and, in particular, controllable contact force of the upper tear-off roller 6a against the lower tear-off roller 6b in order to compact the fiber strands. Since only a single tear-off roller pair 6 is provided, and the effect of a further tear-off roller pair on the fiber strand Ff immediately following the single tear-off roller pair 6 is omitted, the lack of effect of the missing tear-off roller pair can be at least partially compensated for by a controlled force exerted by the upper roller 6a against the lower roller 6b and thus on the fiber strand Ff.The same applies to the setup of the pressure control device 21 in conjunction with the take-off rollers 8, so that the fiber pile Ff can also be treated with a controlled force application even after passing over the take-off table 11.

[0043] The first pair of table calender rollers 22 shown has the same arrangement as the belt feeder 41, so that the fiber web Ff, consolidated after the take-off rollers 8, enters the belt feeder 41 as a web V and can enter the rollers of the table calender 22 as a fiber ribbon Fb without further deflection. An example of another pair of table calender rollers 22' is shown, which requires a deflection of the fiber ribbon Fb by 90°, and if the fiber ribbon Fb continues horizontally, a further deflection of 90° may be necessary. These deflections of the fiber ribbon Fb can result in a more uniform structure of the fiber ribbon Fb, and an arrangement of the table calender rollers 22, 22' at an angle of inclination, for example 45°, is also conceivable.

[0044] In Fig. Figure 4 shows another illustration of one of the comb heads 1 of a combing machine K according to a further embodiment of the invention, wherein identical or structurally equivalent components are provided with the same reference numerals as in Fig. 3, so that the description of the Fig. 3 is referenced. The illustration shows a different version from Fig. 3 a pair of additional rollers 27, which is arranged following the take-off roller pair 8 and serves to further consolidate the nonwoven fabric V before the belt funnel 41 follows to form the fiber strip F8.

[0045] During operation of the combing head 1, only the tear-off roller pair 6 performs the stepping motion. The roller pairs 8, 22, and 27 run continuously in the take-off direction A of the nonwoven fabric V, thus significantly reducing the energy required to operate the combing head 1, as no second roller pair needs to be driven by the stepping motion. This results in a simpler design, lower energy consumption, and reduced wear. Furthermore, the drive system for powering only one tear-off roller pair 6 does not need to be as robust, since the periodically accelerated rotating masses are smaller.Advantageously, the tasks of the second pair of tear-off rollers usually used, namely the consolidation of the fiber web Ff after the first pair of tear-off rollers 6, can be shifted to the subsequent pairs of rollers 8, 22 and / or 27, so that finally a strip of at least almost the same quality can be produced as a strip from a combing head 1 with two pairs of tear-off rollers 6, 7 according to the prior art.

[0046] Fig. Figure 5 shows an alternative of the combing head 10 of the combing machine 1 with a parallel belt system 23 into which the nonwoven fabric V can be fed after it has left the take-off roller pair 8. The parallel belt system 23 has an upper belt 24 and a lower belt 25, the two belts being pressed against each other along their entire length, thus also consolidating the nonwoven fabric V. The advantage of the parallel belt system 23 is that the nonwoven fabric V is not merely consolidated across its width by means of line contact, but rather by surface contact with the upper and lower belts 24 and 25. For further details regarding the other elements described, please refer to the description of the Fig. 3 referred.

[0047] In the Fig. 6, Fig. 7, Fig. 8 to Fig. Figure 9 shows various embodiments of a modified extraction table 11. In contrast to the one shown in the Fig. 2, Fig. 3, Fig. 4 to Fig. The modified extraction tables 11 shown in the 5 extractor tables 11 are adjustable, or rather adjustable in their geometry.

[0048] Fig. Figure 6 schematically shows the extraction table 11 according to a first embodiment with a first section 12, which is designed as a lower impact element. An upper cover 9, which is associated with the first section 12, creates a channel 10, which is additionally limited by side guides 14. The upper cover 9 is designed to pivot about a fixed first pivot axis 15 and can limit the channel 10 at the top.

[0049] The first section 12 is designed to pivot about a fixed second pivot axis 16, so that the inclination of the components 9, 12 can be adjusted, but at most up to an angle α ≤ 70° to the horizontal or angle β ≤ 70° to the horizontal.

[0050] The adjustment of the first section 12 controls the guidance of the fiber pile Ff through the channel 10. The first section 12, which acts as an impact element, is designed to rise in the direction of material flow for the fiber pile Ff to be formed, together with the upper cover 9. This allows the wave pattern in the fiber pile Ff to be influenced. Fig. Figure 6 shows, by way of example, the limits of a pivoting range of the first section 12 and the cover 9 in dashed lines. If the fiber web Ff runs from the tear-off roller pair 6 into the take-off table 11, a particular influence on the shaft of the fiber web Ff can occur (see Figure 6). Fig. 3, Fig. 4 to Fig. 5) because the inclination of the first section 12 or the cover 9 has a direct influence on the design of the wave of the fiber web Ff, which in turn influences the quality of the fiber web Ff. Following the first section 12, the second section 13 of the take-off table 11 is inclined downwards in the direction of material flow for the fiber web Ff. After passing over the take-off table 11, the fiber web Ff finally enters the take-off roller pair 8, between which the fiber web Ff is consolidated into a nonwoven fabric V.

[0051] Fig. Figure 7 shows a second embodiment of the take-off table 11 between the tear-off roller pair 6 and the take-off roller 8. The view shows a cover 9 that can be moved parallel to the first section 12, thus also influencing the shape of the fiber web's wave. The distance between the first section 12 and the cover 9 is therefore variably adjustable. Preferably, the height of the channel 10 between the first section 12 and the cover 9 can have a value of 5 mm to 30 mm, more preferably 10 mm to 30 mm, and particularly preferably 15 mm to 25 mm. The first section 12, on the other hand, can be adjusted about the pivot axis 16.

[0052] The steepness of the first section 12 of the take-off table 11, which serves as an impact edge, can influence the resulting quality of the fiber nap Ff, which depends on the fiber length and thickness of the fiber nap Ff (overlap geometry of the fiber strands). The distance of the first section 12 from the cover 9, which can be of a variable design, also depends on this. The finer the quality of the fiber nap Ff, the narrower the channel 10 can be set.

[0053] Both variants of Fig. 6 and Fig. The seven components could also be combined in principle, with component 9 being designed to pivot about the pivot axis 15 and with the pivot axis 15 not being fixed in position, but rather its distance relative to component 12 being adjustable. This provides another possibility to achieve optimal fiber pile quality Ff depending on fiber quality and combing productivity, and at the same time to influence the size and intensity of the resulting wave.

[0054] Fig. Figure 8 shows a third embodiment of the extraction table 11, in which, unlike the embodiment according to the Fig. 6. The relative arrangement of the first and second sections 12, 13 to each other is fixed. The geometry of the extraction table 11 can only be changed by parallel displacement of the cover 9.

[0055] In addition to the geometric design of the take-off table 11, its length is also important. The length must be sufficient to continuously unwind the fiber web Ff formed in the piling step process. Particularly at high production speeds, the take-off table 11 must be short enough to quickly consolidate the resulting fiber web Ff into a nonwoven. Preferably, the length of the take-off table is between 200 mm and 400 mm, more preferably between 250 mm and 350 mm. This length comprises the plane of the first and second sections 12, 13 over which the fiber web Ff slides. The length changes depending on the... Fig. 6, Fig. 7 to Fig. The embodiments shown in section 8 do not change with the angle of inclination α. ​​However, a change in length is possible in the embodiment shown in section 8. Fig. 9 shown.

[0056] Fig. Figure 9 shows a third embodiment of the extraction table 11, which is similar to the first embodiment according to Fig. Figure 6 shows a pivotable arrangement of components 9 and 12. It differs in that the pivot axis 16 is not arranged between components 12 and 13, as in the Fig. 6, but at the end of component 12 facing the tear-off roller pair 6, analogous to the arrangement of the pivot axis 15 on component 9. To allow adjustment of the first section 12, a pivot connection 19 is formed between components 12 and 13. The second section 13 comprises two shaped parts, in particular sheet metal parts, 17 and 18, which together form the second section 13. The two shaped parts 17 and 18 overlap along an overlap area, which is illustrated by a double arrow and reference numeral x. The shaped part 17 is connected to the first section 12 via the pivot connection 19. The second shaped part 18 is pivotably held along a fixed third pivot axis 29 at the end of the second section 13 furthest from the pivot connection 19. The first molded part 17 lies partially overlapping on the second molded part 18, so that the fiber pile Ff can be gently guided over the second section 13 towards the take-off roller pair 8.By adjusting the first section 12 about the pivot axis 16 (angle α) a change in length of the second section 13 results, so that the degree of overlap or the overlapped length x changes.

[0057] The maximum tilt angle of α ≤ 70° or β ≤ 70° as well as the horizontal and vertical orientation of the extraction table 11 applies to all embodiments of the Fig. 6, Fig. 7, Fig. 8 to Fig. 9 likewise. Likewise, the adjustment angle when setting the inclination of the first section can be 12 + / - 20°.

[0058] Fig. Figure 10 represents a nonwoven guide element 26 against which the nonwoven fabric V comes into contact when, for example, it leaves the take-off rollers 8. The nonwoven guide element 26 is shown in the illustration as a passive element, and the nonwoven fabric V only comes into contact with the guide element 26, which is oriented obliquely to the direction of travel of the take-off rollers 8, so that the nonwoven fabric V can ultimately enter the belt hopper 41. The guide element 26 can have different geometries, for example, a round or rectangular cross-section. This allows the edges of the fiber pile Ff to be influenced.

[0059] The Fig. 11 and Fig. Figure 12 shows an alternative design of the nonwoven guide element 26, which is designed as an active element. For example, the nonwoven guide element 26 can comprise a driven belt against which the nonwoven V is brought into contact and can be fed to the belt funnel 41 without friction and, in particular, without relative movement to the belt of the nonwoven guide element 26. Fig. Figure 11 shows an end-arranged belt funnel 41, and Fig. Figure 12 shows a belt hopper 41 to which the nonwoven fabric V is fed from both sides with respective nonwoven fabric guide elements 26. At least one further pair of rollers can be arranged before or after the belt hopper 41, for example the table calender rollers 22 or the auxiliary rollers 27. The discharge table 11 can also have means for transporting the fiber web Ff, for example driven rollers.

[0060] The invention is not limited in its implementation to the preferred embodiment described above. Rather, a number of variants are conceivable, which utilize the solution presented even in fundamentally different designs. All features and / or advantages arising from the claims, the description, or the drawings, including design details or spatial arrangements, can be essential to the invention, both individually and in various combinations. Reference sign 1 comb head 2 forceps apparatus 3 feed cylinders 4 round comb 5 fixed comb 6 pairs of tear-off rollers 6a upper tear-off roller 6b lower tear-off roller 7 tear-off roller pairs 8 take-up rollers 9 Cover 10-channel 11 Extractor table 12 first section 13 second section 14 Side guide 15 swivel axis 16 swivel axes 17 sheets 18 sheets 19 Swivel connection 20 Pressure control device 21 Pressure control device 22 table calender rollers 23 parallel conveyor system 24 Upper band 25 Lower band 26 Fleece guide element 27 additional rollers 28 Discharge table 29 Swivel axis 40 stretching machine 41 belt funnels 42 belt funnels 43 cans A Deduction direction F, F1-F8 Fiber tape Ff fiber pile K combing machine V fleece W cotton wraps WB Wattenband α, β Angle of inclination x adjustment range QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] WO 2020 / 208454 A1

[0009] EP 1 774 073 B1

[0010] EP 1 774 072 B1

[0011]

Claims

Combing machine (K) with several combing heads (1), wherein the combing heads (1) each have a gripper apparatus (2) through which a cotton strip (Wb) provided by a cotton roll (W) can be guided, further comprising a round comb (4) and a fixed comb (5) for combing out combed fibers from the cotton strip (Wb), a pair of tear-off rollers (6) for tearing off a fiber fiber from the cotton strip (Wb) and for soldering the fiber fiber to a fiber web (Ff), wherein each combing head (1) is followed in the material flow direction by a take-off table (11), means for consolidating the fiber web (Ff) into a nonwoven (V) and a belt funnel (41) for forming the nonwoven (V) into a fiber strip (F1 - F8), characterized in that each combing head (1) has a single pair of tear-off rollers (6), and that the trigger table (11) has a first rising section (12),the fiber web (Ff) formed by the single tear-off roller pair (6) is guided to a continuously rotating pair of take-off rollers (8). Combing machine (K) according to claim 1, characterized in that each combing head (1) has a first pressure control device (20) with which the pressure of an upper tear-off roller (6a) against a driven lower tear-off roller (6b) of the tear-off roller pair (6) can be adjusted and / or controlled. Combing machine (K) according to one of claims 1 to 2, characterized in that the pair of take-off rollers (8) has a second pressure control device (21) with which the contact pressure between the two rollers of the take-off rollers (8) can be adjusted and / or controlled. Combing machine (K) according to one of claims 1 to 3, characterized in that, in each combing head (1) viewed in the direction of movement of the fiber strip (F1-F8), at least one pair of table calender rollers (22, 22') follows the arrangement of the take-off roller pair (8), wherein the contact pressure between the two rollers of the table calender roller pair (22, 22') is at least adjustable. Combing machine (K) according to claim 4, characterized in that the table calender roller pair (22) is arranged relative to the belt funnel (41) such that the direction of passage of the fiber strip (F1-F8) through the table calender roller pair (22) corresponds to the direction of passage of the fiber strip (F1-F8) through the delivery roller pair (20), or that the table calender roller pair (22') is arranged relative to the take-off rollers (8) such that the direction of passage of the fiber strip (F1-F8) through the table calender roller pair (22') is perpendicular to the direction of passage of the fiber strip (F1-F8) through the belt funnel (41). Combing machine (K) according to one of claims 1 to 5, characterized in that, viewed in the direction of movement of the nonwoven fabric (V), at least one parallel belt system (23) follows the arrangement of the take-off rollers (8), wherein the nonwoven fabric (V) is guided between an upper belt (24) and a lower belt (25), at least one of which is driven. Combing machine (K) according to one of the preceding claims, characterized in that a space formed in the take-off table (11) for guiding the fiber pile (Ff) is limited on the underside by a first section (12) and on the upper side by a cover (9), wherein the first section (12) and / or the cover (9) is adjustable in an inclination (α) relative to the horizontal or an inlet direction of the fiber pile (F1-F8). Combing machine (K) according to claim 7, characterized in that the angle of inclination (α) of the first section (12) is a maximum of 70°. Combing machine (K) according to claim 7, characterized in that the distance of the cover (9) to the first section (12) is adjustable, in particular by means of a parallel displacement of the cover (9) relative to the first section (12). Combing machine (K) according to claims 7 to 9, characterized in that the distance of the cover (9) to the first section (12) has a value of 5mm to 30mm and preferably of 10mm to 30mm and particularly preferably of 15mm to 25mm Combing machine (K) according to one of the preceding claims, characterized in that the length of the take-off table (11) has a value of 20 cm to 40 cm, preferably 25 cm to 35 cm, wherein the length is composed of the plane of the first and a second section (12, 13). Combing machine (K) according to one of the aforementioned claims 1 to 11, characterized in that the position of the first section (12) of the take-off table (11) is fixed relative to the gusset of the tear-off rollers (6). Combing machine (K) according to claim 12, characterized in that the second section (13) of the take-off table (11) is adjustable in length. Combing machine (K) according to one of the preceding claims, characterized in that the nonwoven fabric (V) is guided into the belt funnel (41) after the take-off rollers (8) by at least one nonwoven fabric guide element (26). Combing machine (K) according to claim 1, characterized in that at least one pair of additional rollers (27) are arranged behind the take-off rollers (8). Combing machine (K) according to claim 7, characterized in that the adjustment angle of the first section (12) and the cover (9) is + / - 20°.

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