EP0799916A2 - Combing machine with a controlled draw frame - Google Patents

Abstract

The comber, to produce a sliver has an initial drawing stage (10) with several pairs of rollers (11,12,14) and a further drawing stage (40) with a control (35,50,48) to compensate for short wave mass swings. The signals from the monitor (32) control the drive of the second drawing stage (40). Also claimed is an operation where the fibre mass (8) is drawn under control and the drawn fibre masses are brought together to be measured. The measurement signals are passed to the control (35,52,21) for the first drawing stage (10) and the control (35,50,48) for the second drawing stage (40). The sliver material is drawn on leaving the monitor (32), and laid (53).

Description

The invention relates to a device or a method for forming a fiber sliver with a first regulated drafting system with a plurality of pairs of rollers for the controlled stretching of the fiber mass fed to the drafting system, the nonwoven fabric released by the drafting system being combined and fed to a measuring element, of which the The measured fiber material is then transferred to a second drafting system, the regulating device of the first drafting system regulatingly intervening in the drive of the first drafting system to compensate for mass fluctuations on the basis of the signals emitted by the measuring element, including a predetermined target value.

In a spinning line for processing fibers there are various machines in which a sliver is formed as the end product. Such machines are, for example, the card, the draw frame and the comber.

In order to improve the processing of the sliver formed for a subsequent machine that processes the sliver, it is advantageous if the sliver formed can be presented to the respective machine with a uniform mass and without interruption.

Various solutions can therefore be found in the prior art, regulating devices being used on the corresponding machines to regulate the sliver uniformity.

Such regulating devices are used in particular in the area of the line, as is known, for example, from EP-A2 176 661 and US Pat. No. 3,440,690. Also in the area of the combing machine it is known from EP-A1 376 002 and from JP-OS-53-86841 to provide a regulating device for the drafting system installed on the combing machine.

The ever increasing production rates inevitably result in an increase in the processing speed of the fiber material or the conveying speed of the end product formed (for example a sliver).

This means that the requirements for the regulating devices described have become ever greater. The requirements placed on the measuring elements for measuring the fiber masses, for example for detecting short- and long-wave mass fluctuations, have also been increased. This is due, on the one hand, to the higher conveying speeds already described and, on the other hand, to the increasing and increasing masses to be recorded, and also to the increased requirements with regard to the quality of the end product.

The slivers formed in the machines described are generally deposited in cans via a special depositing device, which can then be transported manually or automatically to a subsequent processing machine.

On the one hand there is a demand for the formation of a uniform sliver and on the other hand for the storage of an uninterrupted sliver. A sliver break in a can template leads to additional and undesirable downtimes in the subsequent processing process.

With the existing and known regulating devices on drafting systems, good results can sometimes be achieved with regard to the uniformity of the sliver formed, but these results are only partially sufficient in view of the increased requirements with regard to quality and a desired storage. In particular, the soldering points created in the combing machine during the tear-off and soldering process can only be compensated for with considerable effort and sometimes with several line passages after the combing machine.

The object of the invention is now to propose a device or a method for forming a sliver which is of high quality in terms of its uniformity and which ensures the storage of an uninterrupted sliver.

This object is achieved by the characterizing part of patent claim 1 and by the characterizing part of the method claim according to patent claim 12.

It is proposed that the second drafting system be provided with a control device to compensate for short-wave fluctuations in mass, which controls the drive of the second drafting system based on the signals emitted by the measuring element.

A reduced fiber mass for the measuring process is presented to the measuring element, which is arranged after the first drafting system. This makes it possible to also use measuring elements for detecting short-wave fluctuations in mass, for example for detecting soldering points in the combing machine, which can also scan the fiber mass with a non-mechanical device. This means that commercially available purely electronic or piezzoelectronic sensors can be used which, on the basis of the reduced fiber mass, can carry out a very precise detection of mass fluctuations that occur. The short-term fluctuations in mass can be better recorded after the first drafting system, since they are correspondingly shifted along the length by the first drafting process. An example of this is a mass fluctuation that occurs as a result of the soldering on the combing machine, which usually occurs every 30 mm. This means that if the drafting system works with a draft ratio of 5: 1, for example, this distance between the fluctuations in mass due to soldering is extended to 150 mm.

Due to the reduced mass presented to the measuring element, irregularities can also be detected better and more precisely in the inner region of the fiber mass presented. This makes it possible, based on the delivery of an exact measurement signal to a control device for a subsequent further drafting system, to provide precise values for controlling the fiber mass presented to the second drafting system, for example in the form of a fiber band. Since the fiber mass to be controlled in the second drafting system is relatively small, the control dynamics can be kept at a low value. This means that the control of a smaller fiber mass is easier to master or perform with regard to the dynamic control interventions than would be the case with a large fiber mass. In addition, with the proposed arrangement, only one measuring element is necessary in order to regulate the first drafting system on the one hand and to control the second drafting system on the other hand. This enables a compact and simple design.

It is further proposed that the pair of output rollers of the first drafting system be regulated. This makes it possible to compensate for or compensate for the transport fluctuations in the sliver that result from the control intervention by means of a corresponding coupling of the subsequent drives (second drafting device, depositing devices), without tracking the drives of the supply devices and without additional buffer storage.

The pair of output rollers of the second drafting system is preferably controlled on the basis of the output measurement signal.

Furthermore, it is proposed that the fiber sliver formed on the second drafting system be stored in a memory via a depositing device and that the drive of the depositing device and the drive of the pair of input rollers of the second drafting system are coupled in terms of drive with the drive of the pair of output rollers of the first drafting system.

This enables a simple device which enables the devices downstream of the first drafting system to be reliably tracked without a buffer store. Since only short-wave interventions take place in the second drafting system, no buffer is required between the second drafting system and the storage device.

In order to enable additional monitoring of the fiber sliver in relation to the fiber mass, it is proposed to provide a further measuring element in the area between the second drafting device and the laying device.

Furthermore, it is proposed that the regulating device be provided with a timing element, by means of which the drive of the drafting devices, the laying device and the supply devices for feeding the fiber mass is stopped, if the deviation of the mass determined by the first measuring element from a predetermined target value during a certain tolerance limit during of a time interval that is greater than a predetermined time period. This ensures that, for example, if a sliver fed to the first drafting system fails over a defined period of time, this failure can be compensated for by the regulating device. After a certain time or a predetermined time interval, this error of a reduced supply of fiber mass should be remedied. This means that the missing sliver should be replenished. If this is not the case, the timer is used to stop the machine, on the one hand to indicate an incorrect delivery to the operator and, on the other hand, to enable the missing sliver to be tracked.

If one or more fiber slivers fed to the first drafting system fail or if windings occur within the first drafting system, fluctuations in mass can occur which can no longer be compensated for by the subsequent regulating drafting system. Such faults are recognized by known monitoring devices in the drafting system or in the area of the feed devices and transmitted to a control device. This control device can then be used to actuate or actuate a device after the machine has stopped for deriving the fiber material discharged from the first drafting system from the normal conveying direction. The feed device upstream of the drafting system is started again with the first drafting system after the error or fault has been rectified. As a result, the section of the fiber material provided with a missing mass can be separated until the desired fiber mass is available again. During this separation process of the reduced fiber mass, the aggregates following the first drafting system (second drafting system, laying device, etc.) are stopped. This means that the end of the sliver fed to the regulating drafting system is not conveyed during the separation process and is available in sufficient length for the attachment of a new sliver end. As soon as a sliver of sufficient mass can be formed again, it is attached to the sliver that is running out and at a standstill, and the entire drives are then set in motion again.

It is therefore further proposed that the device for discharging the fiber material is followed by a device for attaching a new sliver end to the sliver end that is running out and that the drive of the further drafting system following the first drafting system and the depositing device is at least temporarily separated from the drive of the first drafting system. This can be done, for example, via a clutch in order to separate and shut down the drive devices following the first drafting system. When using individual electric motor drives, this shutdown takes place via signals correspondingly output by a control device. The tracking of the fiber mass to the first drafting system is monitored during the separation process, so that the point in time is recognized at which the normal fiber mass is again available to initiate normal operation.

It is further proposed that at least two fiber slivers are formed after the first drafting system, which are brought together to form a fiber sliver before entering the subsequent measuring element. The attachment device is designed so that each of the individual slivers can be attached offset with respect to the conveying direction. As a result, the two attachment points do not meet when the two slivers are brought together. This means that the thickness fluctuations in the area of the piecing that may occur during the piecing process are shifted against each other so that they cannot add up. The mass fluctuation that may occur during the piecing process is thus halved with respect to the merged sliver.

The use of individual electrical drives for the drafting systems or the depositing device enables simple separation of certain drive areas in order to separate a faulty fiber mass from the process.

The invention is also solved by the method steps according to the characterizing part of claim 12.

Fig. 1

eine schematische Seitenansicht einer Kämmaschine mit der erfindungsgemäss vorgeschlagenen Anordnung,

Fig. 2

eine vergrösserte Teilansicht der Streckwerkseinrichtungen in Draufsicht gemäss Fig. 1,

Fig. 3

eine schematische Seitenansicht nach Fig. 2 mit einem Ausführungsbeispiel einer Antriebseinrichtung,

Fig. 4

ein Ausführungsbeispiel gemäss Fig. 2 mit einer Ableitvorrichtung für das Fasergut,

Fig. 5

ein weiteres Ausführungsbeispiel gemäss Fig. 2 mit einer Ableitvorrichtung für das Fasergut,

Fig. 6

ein Diagramm zur Darstellung der gelieferten Fasermasse und

Fig. 7

eine schematische Darstellung des Ansetzvorganges entsprechend dem Ausführungsbeispiel nach Fig. 5.

Further advantages of the invention are described and shown in more detail with reference to the following exemplary embodiments. Show it:

Fig. 1

2 shows a schematic side view of a combing machine with the arrangement proposed according to the invention,

Fig. 2

2 shows an enlarged partial view of the drafting device in plan view according to FIG. 1,

Fig. 3

2 shows a schematic side view according to FIG. 2 with an exemplary embodiment of a drive device,

Fig. 4

2 with a discharge device for the fiber material,

Fig. 5

2 another embodiment according to FIG. 2 with a deflecting device for the fiber material,

Fig. 6

a diagram showing the fiber mass delivered and

Fig. 7

5 shows a schematic illustration of the attachment process corresponding to the exemplary embodiment according to FIG. 5.

In Fig. 1, the longitudinal part 2 of a combing machine 1 is shown, on which bobbins 4 rest for unrolling and combing out by subsequent combing devices. As a rule, eight such coils are presented on a comber for unrolling. The slivers formed in the individual combing heads are combined via a conveyor table 6 on the longitudinal part 2 to form a sliver composite 8 and fed in the conveying direction F to a first drafting system 10. The slivers emitted by the individual combing heads generally have a number or sliver mass of 8 g / m, as a result of which the sliver composite 8 consists of eight slivers with a mass of 64 g / m. This fiber mass is subjected, for example, to a five-fold draft in the drafting system 10, as a result of which the fiber mass released from the drafting system 10 is reduced to approximately 12 g / m 2. The drafting system 10 is equipped with a known advance between the drafting roller pairs 11 and 12. The main draft occurs between the drafting roller pairs 12 and 14. The draft ratios (pre-drafting) between the drafting rollers 11 and 12 are fixed, while the main draft between the rollers 12 and 14 is regulated by a regulating device in accordance with the signal of a subsequent measuring element 32. The drafting rollers 11 and 12 are driven via a schematically illustrated drive train 16 by a gear 18 with fixed transmission ratios. The transmission 18 is connected to the drive train 19 with a Main gear 20 connected, which is driven by a motor 22. The motor 22 is controlled via a control unit 25. The output rollers 14 of the drafting system 10 are driven via the drive train 17 by a differential gear 21, which is connected to the gear 18 via the drive train 13. To carry out the control intervention (change in the main distortion), the differential gear, which is driven via the drive train 13 at a constant speed, can be overridden by a control motor 52. The control motor 52 receives its control impulses from a control unit 35, which is controlled on the basis of a predetermined target value in comparison with the actual value (fiber mass) determined by the measuring element 32. The nonwoven fabric 28 emerging from the first drafting system 10 is combined to form a fiber band 30 and fed to the measuring element 32. This can be seen in particular from the illustration in FIG. 2, with the formation of the fiber sliver 30 in front of the measuring element 32 by the condensation of the fiber fleece 28 via a guide element 29. The cross section of the sliver 30 formed can have a round, an oval or a rectangular shape, although other shapes would also be possible. The measuring element 32 can either be of mechanical construction (for example grooved rollers) or function on an electronic scanning basis. Such measuring elements can already be found in various design variants from the known prior art. The signal of the measuring element 32 is fed to the control unit 35 via a path 33, which is connected to the control unit 25 via a path 36. The control unit 35 could also be integrated directly in the control unit 25. The sliver 30 emitted by the measuring element 32 is fed to a drafting device 40, which is provided with a control device. The drafting system 40 consists of a pair of input rollers 42 which, with a pair of rollers 43, executes a pre-set position. These two pairs of rollers are driven by the differential gear 21 via a drive train 15, a clutch K and a drive train 23. For the sake of clarity, the detailed illustration of corresponding mechanical translations has been omitted. This drive connection ensures that the speed of the pair of output rollers 14 of the first drafting system 10 and Input roller pair 42 of the drafting system 40 are matched to one another, so that both roller pairs rotate approximately at the same peripheral speed. This means that there is a mechanical coupling between these two pairs of rollers 14 and 42 which ensures synchronism. There may be a certain tensioning delay between the two pairs of rollers 14 and 42. A differential gear 48 is driven by the gear 20 via a drive train 59, which in turn drives the pair of output rollers 44 of the drafting device 40 via a drive train 49. To carry out a control intervention, the differential gear 48 is connected via a drive train 47 to a control motor 50 which can intervene in a regulating or controlling manner in the drive of the differential gear 48. This means that the drive via the drive train 59 is corrected accordingly or overridden.

The control motor 50 receives its control impulses via the path 51 from the control unit 35, via which the processing of the measurement signal of the measurement device 32 already described takes place. An attempt is made to compensate for the short-wave fluctuations in mass (eg solder joints) and to compensate for the deviations from a specified tolerance range. This means that the aim is to produce a uniform sliver. The control interventions take place when the peaks of the short-wave mass fluctuation determined exceed the predetermined tolerance range. The control signal is then output via path 51 from controller 35 to control motor 50. The sliver 53 removed from the drafting device 40 is guided through a measuring element 55, which is connected to the control unit 25 via a path 56. The fiber mass of the sliver is monitored again in this measuring element and the machine is switched off if there is a deviation from a desired value. Such measuring elements are also known and can be found in the prior art. The sliver 53 is then transferred to a depositing device and deposited in a can 64 by means of appropriate units. These units are, for example, a pair of calender rolls 66 which deliver the sliver to a funnel wheel 68. The sliver enters the can 64 from the funnel wheel and is deposited there in a loop-like manner. The A pair of calender rolls 66, the hopper wheel 68 and a can drive actuator 69 are driven via the drive trains 71 and 72 by an intermediate gear 75. The intermediate gear 75 is connected to the gear 21 via the drive trains 23, 15 and 17 and via the clutch K. Due to this drive connection, the drive of the depositing device 66, 68, 69 follows the variable speed of the differential gear 21. This enables the sliver to be deposited continuously without the need for expensive and susceptible buffers.

As already described above, the sliver formed after the drafting system 10 has a fiber mass of approximately 12 g / m. The draft in the subsequent regulating drafting device 40 is designed such that the fiber sliver deposited in the can 64 has a mass of approximately 5 g / m.

FIG. 3 shows a side view corresponding to the embodiment according to FIG. 2, but the drive system has been changed compared to the embodiment according to FIG. 2. The drafting system 10 is driven by the electric motors M1 and M2 via the drive trains 41, 61, a fixed transmission between the individual roller pairs 11 and 12 being present in the drive train 41 by interposing a transmission gear (not shown). The motor M1, which runs at a constant speed, receives its control pulses from a controller 95 which is connected to the central control unit 25 via the path 70. The motor M2 is designed as a control motor and is controlled by the control unit 95 via the path 87 using a target / actual comparison with the measurement signal of the measuring element 32. The measuring element 32 is connected to the control unit 95 via the path 33 and determines the mass of the fiber material supplied. The measurement signal output to the control unit 95 also shows the short-wave deviations with respect to the band equality, which, as already described, are compensated for by the second drafting arrangement 40. In the second drafting system 40, the two input roller pairs 42 and 43 are driven with an appropriate gear ratio (not shown) via the drive train 65 by an electric motor M3, which generates its control pulses receives via line 88 from the control unit 95. A speed adjustment, in particular between motors M2 and M3, is carried out via control unit 95 in order to match the peripheral speeds of output roller pair 14 with the peripheral speeds of input roller pair 42. The motor M4 is designed as a regulating motor and acts on the output rollers 44 via the drive train 67. On the basis of the signal supplied by the measuring element 32 via the path 33 in conjunction with a predetermined tolerance range, a corresponding control signal is emitted via the path 85 for actuating the regulating motor M4. As a result, the main distortion between the roller pairs 43 and 44 can be changed accordingly and the leveling of the sliver mass can be achieved. As is known, the respective motors M1-M4 can be equipped with sensor devices (not shown) for tapping the rotary movement of the motor shaft in order to ensure that the speeds are coordinated between the motors. In addition, an electromotive single drive M5 is also provided for the storage devices 66, 68 and 69, which is controlled via the path 84 via the control unit 95. The speed of the motor M5 can also be adjusted or adjusted to the regulated speed of the motor M2 via the control unit 95.

A timing element 54 is schematically indicated in the control unit 95, which is connected to the control unit 25 via the path 57. If the mass deviation exceeds a certain value of the actual value measured by the sensor 32 at a predetermined target value over a certain time interval, the machine is stopped by the control unit 25 in order to eliminate the fault. There is a signal for the operator.

FIG. 4 shows an embodiment variant of the exemplary embodiment according to FIG. 2, the guide element 29 being provided with two pivotable plates 26 and 27, which are designed to be pivotable about the pivot axes 37 and 38, following the drafting system 10 or the output roller pair 14. On the representation of a Actuating device for carrying out the pivoting movement has been omitted for reasons of clarity. In addition, a displaceable guide plate 34 is arranged in this arrangement, which in the position shown in FIG. 4 with the plates 26 and 27 enables the nonwoven fabric 28 discharged from the drafting device 10 to be discharged transversely into a container 39. A guide plate 24 is attached below the plates 26, 27. This device allows the section of the nonwoven fabric 28 to be separated from the normal processing process, which is provided with a reduced mass MF. This is shown schematically in the diagram according to FIG. 6, a mass reduction occurring for example at time t1. This reduction in mass can result from the failure of one or more slivers. After the mass reduction has been detected, this can also be done, for example, with the feed device, the machine is stopped and the fault is eliminated. The feed device to the drafting system 10 including the drafting system 10 can then be restarted. The faulty section between the times t1 and t2 is now removed via the guide element 29 in the position shown in FIG. 4. During this removal process, the drafting system 40 and the subsequent depositing devices are stopped, as a result of which the rear end of the fiber sliver 30 is ready to stand still in an attachment device 58. In this case, the clutch K is opened, which is connected to the control unit 25 via the path 31, as a result of which the drive of the drafting system 40 and the depositing device 66, 68 and 69 is prevented. At time t2, at which the desired fiber mass is again present (target), the plates 26, 27 and 34 are pivoted back into the position shown in dash-dot lines and a fiber sliver is thereby fed into the measuring element 32 and the attachment device 58. As soon as the attachment process of the front sliver end with the rear sliver end 30 has been carried out manually or automatically, the drafting device 40 and the subsequent devices are put into operation again by closing the coupling K, which again ensures a normal working process.

5 shows a further exemplary embodiment corresponding to FIG. 4 in order to derive a reduced mass of fiber material from the normal conveying direction F. The fiber material fed to the drafting system 10 is fed in the form of two fiber sliver groups 8a and 8b. Each of the fiber band groups has four fiber bands lying side by side. The fiber sliver groups 8a and 8b are drawn in the drafting system 10 and released as fiber fleeces 28a and 28b lying next to one another. These nonwoven fabrics are combined into separate fiber tapes 30a and 30b via guide plates 24a and 24b with the aid of lateral guide plates 26a, 27a and 26b, 27b. Via a further guide plate 89 and under the action of side plates 82 and 83, the two slivers 30a and 30b are combined to form a sliver 30 before entering a subsequent measuring element 32. The sliver 30 emerging from the measuring element is transferred to the subsequent drafting system 40.

In the conveying path of the individual slivers 30a and 30b, an attachment device 58a and 58b is attached. With this attachment device, a newly adjusted fiber sliver is attached in the event of an interruption. The two attaching devices 58a and 58b are arranged offset with respect to the conveying direction F by the dimension X. As a result, as shown schematically in particular in FIG. 7, the attachment points A1 and A2 are also shifted by the dimension X with respect to the conveying direction F. As a result, any fluctuation in thickness with respect to the fiber sliver 30 that may have occurred during the attachment process at the attachment point A1 or A2 is partially compensated. This means that a poor piecer has only a half disadvantage in relation to the sliver 30.

In the exemplary embodiment according to FIG. 5, in contrast to the exemplary embodiment of FIG. 4, the fiber material to be removed is not discharged laterally but downward into a can 39. The guide plates 24a and 24b, including the lateral guide plates, are pivoted downward about the axis of rotation D. This pivoting can be done automatically by a device, not shown, the pivoting movement is capped. This means that as soon as the guide plates are in their lower position, the fiber material discharged from the drafting system 10 is discharged into the can 39. In the area of the respective attachment device 58a and 58b, the outgoing ends of the fiber tapes 30a and 30b are ready for an attachment process. As soon as the supplied mass of the fiber material has again reached M target, the guide plates 24a and 24b are pivoted back into their upper, approximately horizontal position, as a result of which the attachment process to the fiber band ends of the fiber bands 30a and 30b can then be carried out. The drive of the second drafting unit 40 and the laying device 66, 68 and 69 is put into operation again by closing the clutch K.

With the device proposed according to the invention, a device is obtained which ensures the production of a high-quality sliver and, on the other hand, avoids an interruption in the sliver which is stored in the can 64.

Claims (12)

Device for forming a sliver with a first, regulated drafting device (10) with a plurality of pairs of rollers (11, 12, 14) for the controlled stretching of the fiber mass (8) fed to the drawing device, the nonwoven fabric (28) released by the drawing device being combined and a measuring element (32) is supplied, from which the measured fiber material is then transferred to a second drafting device (40), the regulating device (35, 52, 21) of the first drawing device (10) to compensate for mass fluctuations on the basis of that emitted by the measuring element (32) Signals intervening in a regulating manner, including a predetermined setpoint, in the drive of the first drafting system (40), characterized in that the second drafting system (40) is provided with a control device (35, 50, 48) for compensating for short-wave mass fluctuations, which are based on the Measuring element (32) emits signals in the drive of the second drafting system (40). Device for forming a sliver according to claim 1, characterized in that the speed of the pair of output rollers (14) of the first drafting device (10) is regulated. Device according to one of claims 1 or 2, characterized in that the pair of output rollers (44) of the second drafting system (46) is controlled. Device according to claim 3, characterized in that the sliver (53) formed on the second drafting device (40) is deposited in a memory (64) via a depositing device (66, 68, 69) and the drive (75) of the depositing device (66 , 68, 69) and the drive of the pair of input rollers (42) of the second drafting system (40) is coupled in terms of drive with the drive (21) of the pair of output rollers (14) of the first drafting system (10). Apparatus according to claim 4, characterized in that between the pair of output rollers (44) of the second drafting device (40) and the depositing device (66,68,69) there is a further measuring element (55) for monitoring the sliver (2) delivered by the second drafting device (40). 53) is arranged. Device according to one of claims 1 to 5, characterized in that the regulating device (35, 50, 48) for the first drafting system (10) is provided with a timing element (54), via which the drive of the drafting systems (10, 40) is provided. the laying device (66, 68, 69) and the supply devices (2) for feeding the fiber mass is stopped when the deviation of the mass determined by the measuring element (32) compared to a predetermined target value exceeds a certain tolerance limit during a predetermined time interval. Device according to one of claims 1 to 6, characterized in that between the first drafting device (10) and the second drafting device (40) is a device (29,26,27,34) for deriving the fiber material discharged from the first drafting device (10) (28) from the normal conveying direction (F) is provided. Device according to claim 7, characterized in that between the measuring element (32) and the device (29, 26, 27, 34) for discharging the fiber material (28) there is a device (58, 58a, 58b) for attaching a new fiber sliver end to it outgoing sliver end (30) is arranged downstream. Apparatus according to claim 8, characterized in that the drive of the feed device and the first drafting device (10) can be separated at least temporarily via a device (K) from the drive of the second drafting device (40) and the depositing device (66,68,69). Device according to one of claims 8 or 9, characterized in that from the fiber mass fed to the first drafting device (10) after the Stretching process at least two slivers (30a, 30b) are formed, which are combined in the measuring element (32) and delivered to the subsequent drafting unit (40) and the attachment device (58a, 58b) is arranged in the region of the individual slivers formed so that the The attachment points (A1, A2) of both slivers produced during the attachment process do not meet when they are combined. Device according to one of claims 4 to 11, characterized in that at least one drafting device (10, 40) and / or the depositing device are equipped with electronic individual drives (M1-M5) which are at least partially coupled to one another in terms of drive via a control unit (95) . Method for forming a sliver with two drafting devices (10, 40) arranged one behind the other, a measuring element (32) for the fiber material discharged from the first drafting device (10) being arranged between the drafting devices, characterized by the following method steps - controlled stretching of the supplied fiber mass (8) - summarizing the stretched fiber mass (28) - measuring the total fiber mass (30) - Transfer of the measurement signal to the regulating device (35, 52, 21) of the first drafting device (10) and to the control device (35, 50, 48) of the second drafting device (40) - Controlled stretching of the sliver (30) delivered by the measuring element (32) - Placing the sliver (53).

Images