EP3543385A1 - Sliver forming unit of a card - Google Patents

Abstract

The present invention relates to a device for guiding a nonwoven strip (18) in a strip forming unit (16) of a carding machine (1) with a guide hopper (24), with a double-walled hopper (26) and with a pair of platen rollers consisting of an upper platen roller (27). and a lower pressure roller (28). The guide funnel (24) is arranged in front of the end funnel (26) and the funnel (26) is located in front of the pair of printing rollers (27, 28). The final funnel has a compressed air supply (31). Between the guide hopper (24) and the end hopper (26) a funnel (25) is provided and a distance between the upper pressure roller (27) and the lower pressure roller (28) is adjustable.

Description

The present invention relates to a device for guiding a nonwoven tape in a tape forming unit of a carding machine.

The carding machine produces a card sliver from fed-in fiber material, which is subsequently processed into a yarn. In this case, a card is usually associated with a hopper which is supplied by a conveyor system with fibers from a blowroom. The fibers are cleaned by the card and parallelized. For this purpose, the fibers are guided over a card drum. From the card drum, the fibers are removed by a pickup in the form of a nonwoven fabric and fed to a band forming unit. The customer consists essentially of a take-off roll, a transfer roller and a pair of output rollers. The fiber fleece extends over the entire working width of the card. In the band forming unit, the nonwoven fabric is brought together into a card sliver. In this case, after leaving the pair of delivery rollers, the nonwoven fabric strikes a fiber-fleece guide element which effects a conveyance of the fiber fleece in the axial direction of the pair of delivery rollers. As a result, the fibers of the nonwoven fabric are brought together to form a nonwoven tape. In the case of cards with a larger working width, for example, two counter-rotating transverse bands working together are used as the non-woven guiding element. Subsequently, the nonwoven tape passes through various guides and funnels to a pair of pressure rollers which causes the final shaping of the card sliver.

From the prior art, for example, a device for guiding a nonwoven tape in a band forming unit of a card after the EP 3 153 607 A1 known. In this case, the fleece coming from the customer is brought together by a nonwoven guiding element to form a fleece band and fed to a Vorverdichterring. The nonwoven tape is then fed to a first and a subsequent second insertion device, wherein the second insertion device is provided with a compressed air supply. The first insertion device protrudes into the second insertion device. With the compressed air, an air flow with a swirl is generated in the space between the first insertion device and the second insertion device such that in the Result in the first insertion a negative pressure arises. This negative pressure pulls the nonwoven tape through the first insertion device. After the second insertion device, the nonwoven strip passes to a squeezing roller pair which form the nonwoven strip into a card sliver. The disadvantage here is the one-stage compression of the nonwoven tape. This leads at high belt speeds to damming the nonwoven tape in front of the final funnel. In this case, air is pressed out of the nonwoven strip in one go, which results in splitting off of fibers or parts of the nonwoven strip. The air contained in the nonwoven web in front of the first insertion device causes the nonwoven web to expand on the one hand in places without tight guidance (for example, between the precompressor ring and the first introduction device) and, on the other hand, a high force is necessary around the nonwoven web without active conveyance through a tapered end To suck guide such as the Vorverdichterring or the first insertion device. In order to achieve a cross-sectional reduction of the nonwoven tape, the air contained in the nonwoven tape must either be able to escape or be compressed accordingly, which is not guaranteed by the disclosed design of the nonwoven tape guide.

Next discloses the EP 0 298 507 A2 a device for automatically merging a textile nonwoven fabric into a sliver. In this case, the nonwoven fabric is combined via a funnel trough into a nonwoven belt and transferred into a funnel-shaped transport channel. At the end of this transport channel an annular gap nozzle is arranged, which generates a concentric flow in the transport direction. As a result, the nonwoven strip passes into a mouthpiece channel at the outlet of which a further annular gap nozzle is attached. As a result, the nonwoven web passes through another mouthpiece channel to a calender roll pair where it is formed into a sliver. By means of a swirl-shaped flow in the first annular-gap nozzle, a tapering of the non-woven band during its threading should be achieved in the event of a restart of the device. A disadvantage of the proposed banding unit, however, is that when an impingement of the nonwoven ribbon on the calender rolls this accumulates at the terminal point of the calender rolls, which leads to blockages. Further, it is disadvantageous that the nonwoven ribbon is passed through a plurality of transport channels, annular gap nozzles and mouthpiece channels, since each transition from a channel piece to a next can lead to buildup, fiber accumulation and disturbance of the currents.

The DE 101 45 733 A1 also discloses a tape forming unit for forming a sliver in a card. The fleece band is fed after leaving the transverse bands by a pile funnel a Kalanderwalzenpaar. One of the two calender rolls is spring-mounted. Due to the selection of the spring and thus the determination of the spring constant, a force matched to the fiber material to be processed can be adjusted to the nonwoven belt at the nip point of the calender roller pair. The possibility of a distance between the calender rolls is possible by the proposed device. The disadvantage here is that a default setting of the distance between the calender rolls in startup operation does not prevent thawing of the fibers before the terminal point. At a high production rate, the fibers begin to accumulate before the nip point before they can be detected by the calender roll pair.

Object of the present invention is therefore to provide a device for guiding a nonwoven tape in a band forming unit of a card, which ensures a trouble-free guidance of the nonwoven ribbon and prevents damming respectively evasion of the nonwoven ribbon from the guide. Further, it is the object of the invention to simplify threading the nonwoven ribbon into the ribbon forming unit.

The object is achieved by a device and a band forming unit or a card with the features of the independent claims.

Proposed is a device for guiding a fleece band in a band forming unit of a carding machine with a guide hopper, with a double-walled hopper and with a pressure roller pair consisting of an upper pressure roller and a lower pressure roller, wherein a distance between the upper pressure roller and the lower pressure roller is adjustable. The adjustment of the distance can be driven pneumatically or via a lever mechanism. This adjustment is helpful in a threading process. By increasing the distance between the upper and lower pressure roller during a Einfädelvorganges the resistance of an incoming nonwoven tape at the beginning of production and thus a damming of the nonwoven tape is prevented before the nip of the pressure rollers. After the Einfädelprozess the distance between the pressure rollers can be reset to the desired value, while the pressure rollers move to the already located between them fleece band. The nonwoven web is guided in a threading process through the nip of the pressure rollers, without resisting, whereby there is no risk of damming the nonwoven tape. In addition, an adjustment or regulation of the force with which the pressure rollers are pressed against each other can be provided. Due to the design of the end funnel as a double-walled cone can be dispensed with additional elements for conveying air such as annular gap nozzles. Likewise, the introduction of air through a double-walled hopper causes suction and transport of the non-woven belt without the flow of air being applied directly to the non-woven belt, as is the case with the delivery nozzle.

The guide funnel is arranged in front of the final funnel and the final funnel in front of the pair of pressure rollers. The final funnel has a compressed air supply. Between the guide funnel and the funnel a funnel is provided. Due to the arrangement of the Vortrichters between the guide funnel and the end funnel, there is the possibility to provide a finer gradation of the taper of the individual funnels respectively guide elements. The difference between the cross sections at the inlet and at the outlet of a guide element, for example, the Vortrichters or the guide funnel, can be made smaller. Also, the inlet cross-section of the final funnel can be made smaller, which must be done in the final funnel less compression of the nonwoven ribbon in his leadership to the pressure roller pair. Also, a part of the air contained in the nonwoven tape escape between the individual guide elements, which means that a lower compression in the subsequent guide element is necessary. In a further embodiment, a disposal of the exiting air can be provided by an active suction in the region of the guide elements.

Advantageously, the funnel is provided with a compressed air supply and double-walled. This results in the possibility to support the leadership of the nonwoven tape with an active promotion. This helps with a threading process at the beginning of production or resumption of interrupted production. The fleece band is supported in its course by the guide elements using the compressed air. The compressed air is fed into the cavity of the double-walled Vortrichters and placed in this cavity in the direction of movement of the nonwoven tape, where the compressed air exits through an annular gap in the conveying direction. As a side effect, on the one hand, the fleece band is compressed by the outflowing compressed air and moved by the hopper against the end hopper and on the other hand arises in the hopper in suction, which sucks the fleece band from the upstream guide hopper.

Advantageously, a control of the compressed air connection of the Vortrichters is coupled with the adjustment of the distance between the upper pressure roller and the lower pressure roller. Particularly preferred is also a coupling with the compressed air connection of the final funnel. As a result, the controller has the opportunity to coordinate optimal conditions and active promotion of the nonwoven web in case of disturbances in the nonwoven guide or even when starting the card.

Preferably, the compressed air supply to the funnel is opened in a starting operation. When starting (or restarting) the card, the incoming nonwoven ribbon must be conveyed through the guide elements. In this case, the active promotion of the pressure roller pair is missing until the time when the nonwoven tape actually reaches the pressure roller pair. To take this fact into account, the compressed air supply to the funnel is opened for a certain duration, whereby the nonwoven ribbon is supported on its way to the pressure roller pair. The threading process is triggered by a manual command to the controller.

Preferably, the pressure rollers are adjusted to a maximum distance during at least a first part of the time of the opening of the air supply to the funnel. As soon as the end of the fleece band through the funnel and the subsequent End funnel is promoted, this can happen unhindered due to the adjustment of the distance of the pressure roller pair. Only when the end of the nonwoven tape has left the pressure roller pair behind, the pressure rollers are moved together again and thus set the specific distance for production.

Further, a tape forming unit for a card with a device for guiding a nonwoven tape as described above is proposed, wherein the tape forming unit is provided with two transverse bands for merging the nonwoven fabric. The use of moving transverse bands has the advantage over static nonwoven guiding elements that there is no friction between the guiding element and the fibers to be moved. A combination of wide non-woven fabrics in high-performance cards is fiber-friendly through the use of transverse bands.

Preferably, fleece band guides are provided between the transverse bands. As a result of the nonwoven ribbon guide as a further guide element, the nonwoven strip leaving the transverse strips is bounded on all sides and introduced into the guide funnel with a predetermined cross section.

Also, a card with a band forming unit is proposed, wherein in the band forming unit two transverse bands and a device for guiding the nonwoven band are provided.

• Beginnen mit der Faservlies-Produktion der Karde
• Öffnen der Druckluftzuführung zum Vortrichter und Vergrössern eines Abstandes zwischen der oberen Druckwalze und der unteren Druckwalze
• Öffnen der Druckluftzuführung zum Endtrichter
• Zusammenführung des Faservlieses durch die Querbänder zu einem Vliesband
• Führung des Vliesbandes durch den Einführtrichter
• Schliessen der Druckluftzuführung zum Vortrichter und Verkleinern des Abstandes zwischen der oberen Druckwalze und der unteren Druckwalze nach Erreichen des Druckwalzenpaares durch das Vliesband.

By the device for threading the nonwoven tape in a tape forming unit of a carding machine, the following procedure is possible at a production start:

• Starting with the nonwoven production of the card
• Opening the compressed air supply to the funnel and increasing a distance between the upper pressure roller and the lower pressure roller
• Opening the compressed air supply to the final funnel
• Merging of the fiber web through the transverse bands to a nonwoven band
• Guide the fleece band through the insertion funnel
• Close the compressed air supply to the funnel and reduce the distance between the upper pressure roller and the lower pressure roller after reaching the pressure roller pair through the nonwoven tape.

The fleece band is visually recognized before reaching the guide funnel and manually triggered according to the process according to which the opening of the compressed air supply to the funnel is made by the controller at this time.

Figur 1

eine schematische Seitenansicht einer Karde nach dem Stand der Technik,

Figur 2

eine schematische Seitenansicht einer Bandbildungseinheit mit einer erfindungsgemässen Vorrichtung und

Figur 3

eine schematische Draufsicht in Richtung X der Bandbildungseinheit nach der Figur 2,

Further advantages of the invention are described in the following exemplary embodiments. Show it:

FIG. 1

a schematic side view of a card according to the prior art,

FIG. 2

a schematic side view of a band forming unit with an inventive device and

FIG. 3

a schematic plan view in the direction X of the band-forming unit after the FIG. 2 .

FIG. 1 shows a carding machine 1 equipped with a hopper 2, a Füllschachtaustrag 5 and a feed channel 3. Fiber flakes 4 arrive after they have passed through the various stages of a blowroom in the hopper 2. The fiber flakes 4 are through the Füllschachtaustrag 5, comprising a feed roller 6 and an opening roller 7 and an air supply 8, passed to the feed channel 3. In Füllschachtaustrag 5 an air supply 8 is provided for the support of the flock transfer to the feed channel 3 and to ensure a cotton compaction in front of a feed device 10 of the carding machine 1. The air supply 8 blows air tangentially to the opening roller 7 along in the feed channel 3 and thereby compresses the fiber flakes into a cotton wool with a necessary for further processing in the carding 1 high cotton weight. A feeding device 10 following the feeding channel 3 feeds the fiber flakes, now in the form of a homogeneous wadding template 11, to the licker-in module 12 of the carding machine 1. The fiber flakes discharged from the feeder 10 from the wadding 11 are further opened by the lickerin contained in the licker-in module 12 and at the same time freed from a portion of the impurities contained therein. The last licker-in roller of the licker-in module 12 finally passes the fibers to the card drum 13, which completely dissolves and parallelizes the fibers. The carding drum 13 cooperates with the cover unit 14. After the fibers have in part carried out several revolutions on the card drum 13, they are removed from the card drum 13 by a take-off unit 15 in the form of a non-woven fabric 17 and fed to a ribbon-forming unit 16 by an output roller pair 9. By the band forming unit 16 formed by the card pulley 13 nonwoven fabric 17 is converted into a card sliver 19. The card sliver 19 is then placed in a jug for further transport (not shown).

FIG. 2 shows a schematic side view of a band forming unit 16 with an inventive device and FIG. 3 a schematic plan view in the direction X of the band forming unit 16 after the FIG. 2 , The fiber web 17 arriving in the belt formation unit 16 in the direction of movement 23 is detected by a pair of delivery rollers 9 and forwarded to paired transverse belts 20. By the transverse bands 20 with their opposite direction of movement 29, the nonwoven fabric 17 is summarized in the direction of the longitudinal axis of the output roller pair 9 to a nonwoven 18. In this case, the nonwoven fabric 17 is guided transversely to its direction of movement 23 in the output roller pair 9 between the two transverse bands 20. As a result of this movement 29 of the transverse bands 20, the fiber fleece 17 extended over the length of the delivery roller pair 9 is brought together by the transverse bands 20 to form the fleece band 18. So that the fibers do not dodge transversely to the direction of movement 29 of the transverse bands 20 during the merging, the transverse bands 20 can be provided on their surfaces with limiting profiles 22.

To support the guidance of the nonwoven web 18 between the transverse bands 20, nonwoven ribbon guides 21 are shown by way of example. By the non-woven band guide 21, which define the space between the transverse bands 20 and the output roller pair 9 and the guide hopper 24 and are arranged above and below the boundary profiles 22, an improved guidance of the nonwoven ribbon 18 can be achieved. However, due to the volume of the nonwoven ribbon 18 is a sufficient leadership of Nonwoven tape 18 by the transverse bands 20 possible, can be dispensed with the nonwoven ribbon 21.

After the nonwoven tape 18 has passed through the bottleneck between the transverse bands 20 this is taken over by a guide funnel 24. The guide hopper 24 serves to reduce the nonwoven web 18 in its extent and pass it on to the funnel 25. The funnel 25 is provided with a compressed air supply 30. In this case, the funnel 25 is double-walled, so that the compressed air supplied in the funnel 25, seen in the direction of movement of the nonwoven ribbon 18, brought to the end of the Vortrichters 25 and distributed over its cross-section emerges. This creates in the funnel 25 a suction which supports the nonwoven band 18 in its movement.

From the hopper 25, the nonwoven web 18 passes into a final hopper 26 and in succession in a pair of pressure rollers consisting of an upper pressure roller 27 and a lower pressure roller 28. By the pressure roller pair, the nonwoven tape 18 is formed into a card sliver 19. Another function of the pressure roller pair is to pull the nonwoven web 18 through the hoppers 24, 25 and 26.

The end hopper 26 is provided with a compressed air supply 31. In this case, the end hopper 26 is double-walled, so that the supplied compressed air in the end hopper 26, seen in the direction of movement of the nonwoven web 18, brought to the end of the end hopper 26 and distributed over its cross-section emerges. Advantageously, the air duct in the end hopper 26 is designed such that the air flowing through is provided with a swirl. This results in the funnel 25 on the one hand, a suction which supports the nonwoven web 18 in its movement and on the other hand is achieved by the twist that the nonwoven web 18 is slightly twisted and thus more compact. The end hopper 26 can be extended as shown by a cylindrical extension between the upper and lower pressure rollers 27 and 28, so that the nonwoven belt 18 is guided as close to the clamping point of the pair of pressure rollers.

The present invention is not limited to the illustrated and described embodiments. Variations within the scope of the claims are as well possible as a combination of features, even if they are shown and described in different embodiments.

LIST OF REFERENCE NUMBERS

1

teasel

2

hopper

3

feeding channel

4

fiber flocks

5

Füllschachtaustrag

6

feed roll

7

opening roller

8th

air supply

9

Roller pair

10

feeder

11

Watt template

12

Vorreissermodul

13

carding drum

14

flat unit

15

customer

16

Banding unit

17

non-woven fabric

18

sliver

19

Kardenband

20

transverse

21

Fleece band leader

22

limiting profile

23

Direction of movement fiber fleece and fleece band

24

guide funnel

25

Vortrichter

26

terminal hoppers

27

Upper pressure roller

28

Lower pressure roller

29

Direction of movement Cross strap

30

Compressed air supply to pre-funnel

31

Compressed air supply to final funnel

Claims (8)

Device for guiding a fleece band (18) in a band forming unit (16) of a carding machine (1) with a guide hopper (24), with a double-walled hopper (26) and with a pair of pressure rollers consisting of an upper platen (27) and a lower platen ( 28), wherein the guide funnel (24) in front of the end hopper (26) and the end hopper (26) in front of the pair of pressure rollers (27, 28) is arranged and the end hopper has a compressed air supply (31), characterized in that between the guide hopper (24 ) and the hopper (26) a Vortrichter (25) and a distance between the upper pressure roller (27) and the lower pressure roller (28) is adjustable. Apparatus according to claim 1, characterized in that the Vortrichter (24) provided with a compressed air supply (30) and is double-walled. Apparatus according to claim 2, characterized in that a control of the compressed air connection (30) of the Vortrichters (25) with the adjustment of the distance between the upper pressure roller (27) and the lower pressure roller (28) is coupled. Device according to one of claims 2 or 3, characterized in that the compressed air supply (30) to the hopper (25) is opened in a starting operation. Apparatus according to claim 4, characterized in that the pressure rollers are adjusted to a maximum distance during at least a first part of the time of opening the air supply (30) to the funnel (25). Tape forming unit (16) for a carding machine (1) having a device for guiding a nonwoven tape (18) according to one of the preceding claims, characterized in that the tape forming unit (16) is provided with two transverse bands (20) for bringing together a nonwoven fabric (17) , Banding unit (16) according to claim 6, characterized in that between the transverse bands (20) fleece band leader (21) are provided. Carding machine (1) with a band forming unit (16) according to one of claims 6 or 7.

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