DE3627057A1 - Method and apparatus for producing a tobacco strand - Google Patents

Abstract

The apparatus for producing a tobacco strand (16) in the tobacco-processing industry, especially a tobacco strand for the production of a cigarette strand, has a rotating strand conveyor (2) which passes through a strand build-up zone (Z), can be charged with fibres in the strand build-up zone to form a strand, and has a discharge end for discharging the fibre strand. Assigned to the strand conveyor 2 is a surplus removal device (19). Means (7, 19) for producing a cross-sectional contour of the fibre strand which at least approximately corresponds, at least along a peripheral section of the fibre strand (16), to the strand contour of the finished strand are provided in the region of the strand conveyor (2). <IMAGE>

Description

The invention relates to a method for producing a Fiber strands of the tobacco processing industry, in particular of a tobacco rod for the production of a ziga rescue strand, in which on a circulating strand Conveyor fibers applied in a strand building zone excess fibers are formed from the fiber strand thus formed be removed and the fiber strand finally for further processing is given off by the strand conveyor.

The invention also relates to a device for manufacturing provide a fiber strand of the tobacco processing In industry, in particular a tobacco rod for the manufacturer a cigarette rod, with a revolving one Strand conveyor which passes through a strand build-up zone, in the strand building zone for strand formation with fibers is loadable and a delivery end for delivering the fiber has strands and with an excess decrease device. In the manufacture of smokable items, especially of cigarettes, is first made from tobacco fibers, from tobacco substitutes or mixtures of both, the usual Lich fed loose in a tobacco shower a circumferential suction train a longitudinally moving endless tobacco rod formed. This tobacco rod is after removing excess on a wrapping material strips and wrapped in them. The educated one The rod of cigarettes is sold in single or multiple cigarettes cut, which are then processed. On this way, rod-shaped smoking articles like Ziga save, cigarillos, cigars and the like from tobacco or Tobacco substitutes are made.  

It is known to form a tobacco rod tobacco fibers on a flat at the bottom of a tobacco channel to watch the suction line conveyor. That not only has the disadvantage that the sides of the tobacco rod to statio nary channel walls slide, which despite the suction strand conveyor created suction easily to undesirable Slip between the suction line conveyor and the tobacco strand and deterioration of the end products can cause, but also that when breaking this Tobacco strands in the subsequent format part, in which the cross section is initially rectangular or square The tobacco rod is shaped into a round cigarette rod and wrapped in a strip of cigarette paper, one whole considerable deformation work must be done, which lead to obstructions in the infeed area of the format can.

Rotating is usually used for the decrease in excess Trimmer disks or circular knives used, their cutting circle at a predetermined height above the bottom of the tobacco touch the channel in the strand area. The cutting circles of the Trimmer circles run in one to the conveyor level of the Tobacco channel parallel plane, so that the tobacco rod at the decrease in excess is rectangular or square Cross-sectional contour receives the subsequent Enema in the format in the desired round shape of the Cigarette strands must be brought. That requires some deformation work and can cause interference in the Give rise to strand promotion.

The invention is therefore based on the object, a Ver drive and a device of the type described Kind of continue to improve, so the risk of interference is reduced during the wrapping of the fiber strand.  

This task is solved with a method of the beginning described type according to the invention in that already at the formation and promotion of the fiber strand at least a peripheral portion of the fiber strand at least one part of the desired strand contour of the finished Strands at least approximately corresponding cross-section contour generated and until delivery for further processing tion is obtained. Because already on the envelope strips of material passed for the cigarette rod A tobacco rod at least in part of the cross section contour of the finished cigarette rod corresponding Has cross-sectional contour, is when the tobacco enters strangs into the format the necessary Verfor reduced work. This eliminates the risk of Reductions in format infeed reduced. According to the Invention happen in particular that at Forming the fiber strand of it on the strand conveyor overlying peripheral portion of at least part of the desired strand contour is shaped accordingly. In Another embodiment of the invention provides that the strand conveyor at least approximates the desired strand contour of the finished strand transverse to Delivery direction is trough-shaped that at Strand formation for applying the fibers to the strand conveyor in a first section of the strand building zone initially only to one running in the conveying direction Median and in a downstream second Section also to those adjacent to the median Negative pressure to the side strips of the strand conveyor Creation of a suction draft created by the strand conveyor becomes. In this way, the tobacco rod already gets during the formation of strands by tobacco oozing fibers on its side facing the strand conveyor one the later cross section of the finished cigarette  strand contour adapted to the strand. Is through at the same time the suction draft control proposed according to the invention a safe and homogeneous along the strand build-up zone Filling the trough-shaped strand conveyor guaranteed because there is initially none in the strand construction area Suction is working towards the side edges of the conveyor a homogeneous filling down to the bottom of the trough that could.

A development of the invention is that for Generation of the desired strand contour of the finished one Strands at least approximately corresponding cross-section contour of the fiber strand, the excess fibers at least approximately along one of these cross-sectional contours running circumferential line can be removed from the fiber strand. A variant of the proposed Ver driving is that a peripheral portion of the Fiber strands in the excess decrease by mechanical Force applied according to the desired cross section contour is deformed. According to the invention is also the decrease in excess at which excess tobacco is removed from the tobacco rod formed, for this purpose used, the fiber strand one of the contour of the finished Corresponding cross-sectional contour to cigarette rod give.

In continuation of the invention, it is for effectiveness of the proposed measures are particularly favorable if the preformed fiber strand directly on a corresponding Hand over the preformed longitudinal wrapping material strips becomes.

In a device of the type described in the introduction the object is achieved in that  in the area of the strand conveyor means for molding little least one peripheral portion of the fiber strand for generation at least a part of the strand contour of the finished strands at least approximately corresponding Cross-sectional contour are provided. According to further training extension of the device according to the invention is provided that the strand conveyor as a means of shaping the fiber strands in the area of the strand building zone transverse to the conveyor towards at least part of the desired strand contour is at least approximately shaped accordingly and that means for applying suction in a first Section of the strand building zone only along a middle streak and in a downstream on the first following second section of the strand building zone in addition to the Side stripe of the suction strand encompassing the fiber strand are provided. This training the Vorrich tion ensures on the one hand that the tobacco rod already during the formation in the strand building zone one of the Cross-sectional contour of the finished cigarette rod ent receives speaking form and that at the same time Strand of homogeneous structure is created. As a strand According to the invention, the conveyor is in a fiber channel air-permeable sliver with a curved bottom intended. The fiber channel is in a first section the strand building zone only in the area of the median strip of the sliver leading domed bottom and in one downstream second section of the strand building zone additionally in the area of the side stripes of the fiber with leading sidewalls through suction air openings connected to at least one vacuum chamber. Herewith is the invention also in modern cigarette machines settable, in which the fiber strand peeled from below and is conveyed hanging on the lower run of the sliver. With a further embodiment of the invention  Suction air routing adapted to the line structure by in conveyor direction from the first section of the strand building zone on both sides of the sliver leading the median strip Raised areas of the ground leading to the hard shoulder the side walls of the fiber channel via suction air openings connected to the vacuum chamber in the channel walls until in the second section of the strand building zone the arched median strip and both side strips of the Sliver are connected to the vacuum chamber. This will correspond to the growth of the fiber strand in the line build-up zone from the median strip of the suction line continuously further page areas Placed negative pressure. This way is an optimal one String construction possible. To compress the To prevent fiber strands towards the median strip according to the invention the suction through the median of the suction line conveyor following the first Section of the strand building zone are reduced.

In a further development of those proposed according to the invention Device is provided that as a means for shaping the Fiber strand provided the excess removal device is and that the excess takeoff means has at least a part of the fiber strand the desired strand contour of the finished strand is little give the approximate cross-sectional contour. The fiber strand thus also receives the fiber sliver on it facing away one of the desired contour of the finished String contour adapted to the cigarette rod. That makes it easier the introduction of the fiber strand into the wrapping strip, and there will be damage to the wrapping strip due to hard tobacco that protrudes from the extruded profile avoided particles.  

Rotating circular knives can be provided as removal means of the excess removal device, which are mounted inclined at a predetermined angle α against the vertical central plane of the strand conveyor. According to another embodiment, rotating circular knives are provided as removal means, the circumferential surface profile of which has a cutting circle and, starting from this cutting circle in the axial direction, has an at least approximately shaped circumferential surface section corresponding to the desired strand contour of the finished strand. With these imple mentation forms of the device according to the invention, the shaping of the fiber strand can be realized in a simple manner with the decrease in excess. In order to save a possibility for the formation of head reinforcements in the cut Ziga saving with the greatest possible protection of the tobacco fibers, the invention provides that means for clocked pneumatic compression of the fiber strand are provided in the area of the excess decrease device.

There is already a surplus take-off facility slanted knife axes known (DE-OS 25 21 414), in which, however, the fiber strand along a molding wheel a curved path is promoted. The knives of the known excess decrease device are as pot knives educated. By combining these features achieved that the tobacco flow conveyed on the form wheel from the cutting edges of the knives in the cutting area only is captured from the sides to cross-sectional changes of the fiber strand during the conveyance for cutting to exclude the excess withdrawal facility. A professional possibly reached with this knife arrangement the top of the fiber strand is transferred of the fiber strand to a flat suction strand conveyor which the fiber strand is held with suction,  canceled. When entering the format, it points out so derte fiber strand at least none of the desired cross cut the finished cigarette rod accordingly Cross-sectional contour more.

The invention has the advantage that the tobacco rod already during its formation in the strand building zone Excitation of loose tobacco fibers one of the strand contours largely adapted to the finished cigarette rod Cross-sectional contour receives the excess decrease is still being completed. So that's when the format runs and when wrapping the fiber strand with the sheath strips of material require less deformation work, which benefits the smooth wrapping process. The consistent suction air provided according to the invention guidance in the course of the desired strand contour of the finished cigarette rod matched fiber channel and Suction line conveyor in the area of the line build-up zone enables a largely homogeneous strand structure. The Acting on the desired strand contour curved suction line conveyor in the median with negative pressure and the sequential connection of Negative pressure on the adjacent side strips of the suction strand conveyor in the following sections of the strand construction zone lead to a uniform density throughout Strand cross-section. In addition, the risk of stoppers in Fiber channel is largely prevented because of the fiber strand not only at the bottom of the fiber channel, but also is guided on the sides by the suction line conveyor and therefore no friction between the fiber channel and the Fiber strand occurs. The entrainment of the fiber strand on the suction line conveyor is slip-free. Because of the missing Friction between the fiber channel walls and the fiber strand is also the density distribution in the axial direction of the  Strands more homogeneous. Even with the preformed fiber strand is a head end reinforcement on simple and effective Way possible by according to the invention in the field the decrease in excess at predetermined intervals amplifier suction is applied to the tobacco band. Total together, the invention leads to increased product quality.  

The invention will now be described with reference to the drawing explained. Show it:

Fig. 1 is a schematic side view of a device according to the invention,

Fig. 2A to 2D show various cross sections through the apparatus of Fig. 1,

Fig. 3 is a developed view of the tobacco channel,

Fig. 4 shows an embodiment of an excess removal device according to the invention,

Fig. 5 shows another embodiment of an excess of take-off means,

Fig. 6 shows a further embodiment of an excess of take-off means,

Fig. 7 is an enlarged view of an A device for generating compressed strand portions in a longitudinal section;

Fig. 8 is a section along VIII-VIII of Fig. 7 and

Fig. 9 is a view of the device of FIG. 7 from below.

Fig. 1 shows an embodiment of a device according to the invention in a schematic side view. 1 designates a suction line conveyor of a cigarette rod machine, which is otherwise not shown. An air-permeable tobacco belt 2 is provided as a suction line conveyor, e.g. B. a perforated tape or an air-permeable fabric tape that rotates around a front and a rear deflection roller 3 a or 3 b and around guide rollers 4 . The lower run 2 a of the tobacco band 2 is guided in a tobacco duct 6 with a curved air-permeable bottom 7 corresponding to the desired contour of the finished term strand. The tobacco channel 6 runs in a straight line in a guide body 8 (see FIGS . 2A to 2D). The tobacco band 2 guided in the tobacco channel 6 is assigned a vacuum chamber 9 on the back, which is connected to a vacuum source 11 and acts through the air-permeable channel bottom 7 and through the air-permeable tobacco band 2 a suction. The tobacco band 2 runs in the direction of an arrow 12 .

The mouth of a tobacco shaft 13 through which loosened tobacco fibers are fed from a distributor (not shown) in the direction of the arrows 14 defines a strand build-up zone Z in which the tobacco rod 16 is expanded up to its full height.

The formation of the fiber channel or tobacco channel 6, which guide the lower run 2a of the sliver or tobacco band 2 and the arrangement of the required suction effecting vacuum chambers 9, FIGS. 2A to 2D and 3. The bottom 7 is of the tobacco channel 6 U-shaped arched so that the lower run 2 a of the tobacco band 2 assumes that the desired shape of the finished strand is fitted. As shown in FIGS. 2A to 2D show that represent different cross-sections through the device of FIG. 1, the vacuum chamber, the entire length of 9 extends over almost the tobacco channel 6 and is associated with the tobacco channel 6 only the domed bottom 7. It is dimensioned in its width so that it causes suction only through a median strip M of the lower run 2 a of the tobacco band 2 . The side stripes S of the lower run 2 a adjoining the median stripe M are not struck by the vacuum chamber 9 with suction. These side stripes S are assigned separate vacuum chambers 17 , which start downstream of a first section Z 1 of the strand build-up zone Z and extend from there almost to the discharge end of the tobacco channel 6 . This can be seen in FIGS. 28 to 2D, which represent sections along the lines BB , CC and DD of FIG. 1. At the end of the first section Z 1 of the strand build-up zone Z, the vacuum chambers 17 on both sides act on a narrow region of the side strips S of the tobacco band 2 adjacent to the central strip M with negative pressure ( FIG. 2B), which becomes continuously wider in the conveying direction until a second Section Z 2 of the strand building zone, both side strips S are completely subjected to negative pressure ( FIG. 2C). By the end of delivery 21 of the tobacco band, both the central strip M and the side strips S are then subjected to suction ( FIG. 2D).

Fig. 3 shows in a not to scale view of a development of the channel bottom 7 and the side walls of the tobacco channel, insofar as they serve to guide the tobacco band 2. In the first section Z 1 of the strand building zone Z , suction air openings 18 are provided only in the central region leading the median strip M of the tobacco band 2 . The suction air openings shown do not show their actual size and arrangement in the channel floor, but only symbolize their overall cross section in the corresponding section or strip of the channel floor 7 . In the second section Z 2 of the strand building zone Z , suction air openings 18 are provided both in the channel strip 7 leading the median strip M and in the side strips S of the lower run 2 a leading side walls of the tobacco channel, as well as downstream of this section until the discharge end of the tobacco band. Here, suction is due to the entire width of the tobacco band. Between the first and the second section of the strand build-up zone, the regions of the side strips S , on which a suction train acts via the vacuum chambers 17 , become continuously wider in the conveying direction. However, it is also possible to further expand the first section Z 1 in the conveying direction and the second section Z 2 against the conveying direction, so that they adjoin one another.

The described arrangement of the vacuum chambers 9 and 17 , the suction air openings 18 in the channel floor 7 and in the channel walls and the suction draft guide thereby brought about ensures that the tobacco fibers first fed in the first section Z 1 safely reach the bottom of the tobacco channel 6 ( FIG. 2A, which shows a section AA of FIG. 1) and not intercepted beforehand by suction pull acting approximately on the side strips and already held onto the side strips S of the tobacco band 2 , as a result of which undesirable cavities could be formed in the tobacco rod 16 . Downstream of the first section Z 1 , in accordance with the further build-up of strands in the build-up zone Z, suction is applied to increasing areas of the side strips S ( FIG. 2B) until in the second section Z 2 the entire tobacco band is under vacuum upon completion of the build-up ( FIG. 2C and 2D). As a result, a very homogeneous strand structure of uniform density is achieved, while at the same time the tobacco rod encompassing the tobacco rod 16 produces a tobacco rod contour which at least approximates the finished cigarette rod and the friction between the channel walls and the tobacco rod is at least reduced. A further improvement in the strand production results in a reduction in the suction train through the median strip M of the lower run 2 a of the tobacco band 2 in the second section Z 2 of the strand building zone, which can be achieved by reducing the cross section of the suction air openings 18 in the channel floor, as shown in FIG. 3 shows.

Downstream of the strand build-up zone Z , an excess decrease device 19 is arranged, which decreases excess tobacco 16 a from the tobacco rod 16 .

The discharge end 21 of the tobacco band 2 or the tobacco channel 6 located above the paper inlet of a garniture 22 in which the tobacco rod with a g 23 a in Pfeilrichtun supplied wrapping material, eg. B. a cigarette paper strip 23 is wrapped. A circumferential format tape 24 conveys the cigarette paper strip 23 and the tobacco rod 16 placed on it under an inlet finger 26 into the format 22 , the contour pre-shaped by the curved bottom 7 of the tobacco channel 6 making the strand inlet easier in the format 22 and the wrapping , because only lower deformation forces have to be applied.

The excess removal device 19 consists, in a known manner, of two rotating circular knives 28 , the cutting circles of which touch in the strand area to reduce excess. The circular knife 28 are designed or arranged so that they take the fiber strand in the excess excess at least a part of the desired strand contour of the finished strand at least approximately corresponding cross-sectional contour. FIGS. 4 to 6 show suitable for this purpose embodiments of the excess decrease means 19. For the sake of simplicity, only the tobacco duct 6 is shown in these figures, with the tobacco band running around the lower run 2 a of the tobacco belt provided as a suction line conveyor. In order to obtain the desired strand contour, the circular knives 28 a of the excess removal device 19 are arranged at an angle α to the strand as shown in FIG. 4. In this way, the excess fibers are removed at least approximately along one of the desired cross-sectional contour of the finished cigarette strand extending circumferential line from the fiber strand. The fiber strand receives an approximately roof-like contour on its upper side facing away from the tobacco band, which is approximated to the round peripheral contour of the finished strand. According to FIG. 5, circular knives 28 b are provided with a narrow cutting circle 29 and a groove 31 shaped according to the desired strand contour. Through the grooves 31 , the strand is shaped in the case of excess excess by mechanical force according to the desired cross-sectional contour. The flutes press the fiber strand into the desired shape, so that this deformation work no longer has to be carried out when the strand enters the 22 format, as was previously the case. The strand thus already receives a contour largely adapted to the desired strand contour during the decrease in excess, as can also be seen in FIG. 2D, which represents a section along the line DD of FIG. 1 through the tobacco rod 16 after the excess decrease. Referring to FIG. 6 wide circular knives 28 are provided c, the peripheral surface 32 obliquely to the cutting circle 29 passes through. These knives also give the tobacco rod 16 a shape which approximates the desired shape of the finished cigarette rod.

Instead of the illustrated in FIGS. 4 to 6 tobacco channel 6 with curved bottom 7, a tobacco channel having a contour may be provided with a flat bottom, so that the fiber strand 16 then page only on its side facing the tobacco band upper facing away from the finished cigarette rod is matched cross-sectional contour receives, which already brings about a considerable improvement in the conditions for the strand entering the 22 format.

The fiber strand 16 after the excess decrease in the inlet area of the format 22 is advantageously placed on an already formed into a trough wrapping material strip, so that its cross-sectional contour, which it received during the excess decrease, is largely preserved and the inlet into the format by reducing the size Deforming work to be facilitated.

The vacuum chamber 9 is interrupted in the area of the excess removal device 19 . At this point, a compression means 33 is arranged in a housing 34 which pneumatically compresses the tobacco strand 16 at predetermined intervals before and during the decrease in excess.

For example, compacted strand sections for head reinforcements can be produced while protecting the tobacco fibers as much as possible. The details of the sealant Ver 33 are shown in FIGS. 7-9.

This compression means 33 , which is shown in Fig. 7 in a longitudinal section and in Fig. 8 in a section along the line VIII-VIII of Fig. 7, consists of a rotating control disc 36 which in a cylin drical receptacle 35 in the housing 34th is rotatably mounted. The outer peripheral surface of the control disk 36 slides sealingly on the inner peripheral surface of the receptacle 35 in the housing 34 .

The circumferential surface of the control disk 36 is provided in a first cross-sectional plane with an annular groove 37 which is interrupted only in a short circumferential section 38 . In this peripheral portion 38 opens in a second cross-sectional plane, a radial bore 39 which is connected to the inside of the control disc 36 with an axial bore 41 . A vacuum from a vacuum source 42 is applied to the bore 39 via the axial bore 41 . The negative pressure of the negative pressure source 42 is greater than that of the negative pressure source 11 , which supplies the negative pressure chambers 9 and 17 with negative pressure. While in the negative pressure chambers 9 and 17 there is a negative pressure of, for example, about 800 mm water column or 80 mbar, lies on the bore 39 z. B. a negative pressure of about 3000 mm water column or 0.3 bar, the z. B. can be generated by means of a commercially available side channel compressor.

In the guide body 8 , in which the tobacco channel 6 runs ver, separate vacuum chambers 43 are provided in the region of the excess take-off device 19 in the conveying direction, into which two bores 44 and 44 a each open transversely to the conveying direction, leading to the cylindrical receptacle 35 in the housing 34 to lead. The arrangement of the vacuum chambers 43 and the bores 44 and 44 a is shown in Fig. 9 Darge, which shows a view of the area of the excess acquisition device according to FIGS . 7 and 8 from below.

The bores 44 lie in a common cross-sectional plane with the annular groove 37 which rotates with the control disk 36 . The bores 44 a are located in a common cross-sectional plane with the circumferential radial bore 39 in the control disk 36 . Two additional bores 47 and 47 a connecting the Unterdruckkam ahead of and behind the area of the excess decrease in numbers means 19 9 rotates in the cross sectional plane of the annular groove 37 to the receiving space 35, in which the control disc 36th The control disk 36 is driven in a fixed speed relationship to the conveying speed of the tobacco belt 2 .

As long as the annular disk 37 is in contact with the bores 44 of the housing 34 during the circulation of the control disk 36 , the assembled tobacco rod 16 is also held in the area of the excess take-off device 19 with the negative pressure prevailing in the negative pressure chambers 9 on the tobacco band, since the negative pressure prevailing in the negative pressure chambers 9 Via the bores 47 and 47 a , the annular groove 37 and the bores 44 also acts in the vacuum chambers 43 on the tobacco band 2 . At regular intervals depending on the conveying speed of the tobacco band, the negative pressure transmitted via the annular groove 37 from the vacuum chambers 9 is interrupted, however, as soon as the circumferential section 38 abuts the bores 44 without an annular groove. At this moment, however, the increased negative pressure is simultaneously applied to the parallel bores 44 a via the umlau fende bore 39 and acts through the lower run 2 a of the tobacco band 2 on the tobacco rod. As a result, the tobacco rod is more strongly drawn towards the tobacco band and compressed, so that the circular knives 28 of the excess removal device 19 remove less tobacco from the rod. Through the bore 39 in the rotating control disk 36 , the bores 44 a in the direction of conveyance are connected in succession to the stronger vacuum source 42 , so that the compressed section of the tobacco rod is conveyed through the line speed under the excess removal device 19 . Following this compression, the annular groove 37 comes again to the openings of the bores 44 so that they are connected again with the normal vacuum from the vacuum chambers 9 and the circular knife 28 of the excess decrease device again remove the normal excess from the strand.

Claims (15)

1. A method for producing a fiber strand of the tobacco processing industry, in particular a tobacco rod for the production of a cigarette rod, in which fibers are applied to a rotating strand conveyor in a strand build-up zone, excess fibers are removed from the fiber strand formed in this way and the fiber strand is finally used for further processing Strand conveyor is delivered, characterized in that at least a portion of the desired strand contour of the finished strand at least approximately corresponding cross-sectional contour is generated and obtained until delivery for further processing already at the formation and promotion of the fiber strand at least on a peripheral portion of the fiber strand. 2. The method according to claim 1, characterized in that that in the formation of the fiber strand of which on the At least the peripheral conveyor overlying section corresponding to a part of the desired strand contour is formed. 3. The method according to claim 1 or 2, characterized net that the strand conveyor ent at least approximately speaking of the desired strand contour of the finished one Strand is shaped trough-like transverse to the conveying direction, that in the strand formation to apply the fibers the strand conveyor in a first section of the strand construction zone initially only to one in the conveying direction running median and in a downstream one second section also on the median strips adjacent side strips of the conveyor a sub pressure to generate a suction draft through the  Strand conveyor is created. 4. The method according to any one of claims 1 to 3, characterized characterized in that to generate the desired Strand contour of the finished strand at least approximated corresponding cross-sectional contour of the fiber strand Excess fibers at least approximately along one of these Cross-sectional contour circumferential line from the fiber be removed. 5. The method according to any one of claims 1 to 4, characterized characterized in that a peripheral portion of the fiber strand when excess is removed by mechanical force kung according to the desired cross-sectional contour is deformed. 6. The method according to any one of claims 1 to 5, characterized characterized in that the preformed fiber strand immediately bar on an appropriately preformed longitudinal Wrapping material strip is passed. 7. Device for producing a fiber strand of the tobacco processing industry, in particular a tobacco rod for the production of a cigarette rod, with a rotating strand conveyor which passes through a strand building zone, can be loaded with fibers in the strand building zone for strand formation and has a discharge end for dispensing the fiber strand , and with an excess take-off device, in particular for carrying out the method according to one of claims 1 to 6, characterized in that in the region of the strand conveyor ( 2 ) means ( 7 , 19 ) for forming at least one peripheral portion of the fiber strand ( 16 ) for production a least at least a part of the strand contour of the finished strand at least approximately corresponding cross-sectional contour are provided. 8. The device according to claim 7, characterized in that the strand conveyor ( 2 ) as a means for shaping the fiber strand ( 16 ) in the region of the strand building zone (Z) transversely to the conveying direction of at least part of the desired th strand contour is at least approximately shaped accordingly and that means ( 9 , 11 , 17 , 18 ) for applying a suction in a first section (Z 1 ) of the strand building zone (Z) only along a median strip (M) and in a downstream second section ( Z 2 ) of the strand building zone (Z) in addition to the fiber strand encompassing side strips (S) of the suction strand conveyor ( 2 , 2 a) are provided. 9. Apparatus according to claim 7 or 8, characterized in that as a strand conveyor in a fiber channel ( 6 ) with a curved bottom ( 7 ) guided, air-permeable sliver ( 2 , 2 a) is provided and that the fiber channel ( 6 ) in one first section ( Z 1 ) of the strand building zone (Z) only in the area of the median strip (M) of the sliver leading curved bottom ( 7 ) and in a downstream second section ( Z 2 ) of the strand building zone (Z) additionally in the area of the Side strips (S) of the sliver leading side walls ( 6 a) through suction air openings ( 18 ) with at least one vacuum chamber ( 9 , 17 ) is connected. 10. Device according to one of claims 7 to 9, characterized in that in the direction of conveyance from the first section (Z 1 ) of the strand building zone (Z) on both sides of the strip (M) of the sliver ( 2 , 2 a) leading bottom ( 7 ) increasing areas of the side strips (S) leading side walls ( 6 a) of the fiber channel ( 6 ) via Saugluftöff openings ( 8 ) in the channel walls with the vacuum chamber ( 9 , 17 ) are connected until in the second section ( Z 2 ) of the strand building zone (Z) the curved central strip (M) and both side strips (S) of the sliver are connected to the vacuum chamber ( 9 , 17 ). 11. The device according to one of claims 7 to 10, characterized in that the suction strip through the middle strip (M) of the suction strand conveyor ( 2 , 2 a) following the first section (Z 1 ) of the strand building zone (Z) is reduced. 12. Device according to one of claims 7 to 11, characterized in that the means for forming the fiber strand (16), the excess removal means (19) is pre-see and that the excess removal means (19) take-off means (28, 28 a to c) comprises which give the fiber strand ( 16 ) an at least part of the desired strand contour of the finished strand at least approximately corresponding cross-sectional contour. 13. The apparatus according to claim 12, characterized in that the removal means rotating circular knives ( 28 a) are provided, which are mounted inclined at a predetermined angle α against the vertical central plane (N) of the strand conveyor. 14. The apparatus according to claim 12, characterized in that as a removal means rotating circular knives ( 28 b , 28 c ) are provided, the circumferential surface profile of a cutting circle ( 29 ) and starting from this cutting circle in the axial direction an at least approximately the desired strand contour of the finished strand has correspondingly shaped peripheral surface portion ( 31 , 32 ). 15. The device according to one of claims 7 to 14, characterized in that means ( 33 ) for clocked pneumatic compression of the fiber strand ( 16 ) are provided in the area of the excess take-off device ( 19 ).