FIBER FILTER PRODUCTION

Abstract

Method and device for producing filter rods of the tobacco-processing industry. The method includes combining and mixing fibers of finite length of two different fiber types, and separating the combined and mixed fibers. The combining and mixing occurs directly before the separating.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:

FIG. 1 is a diagrammatic sectional representation of a device according to the invention;

FIG. 2 is a diagrammatic sectional representation of a device according to the invention in another embodiment;

FIG. 3 illustrates a section from a device according to the invention in another embodiment in diagrammatic representation; and

FIG. 4 illustrates a section from a device according to the invention in yet another embodiment in diagrammatic representation.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.

FIG. 1 shows a sectional representation through a device according to a first exemplary embodiment of the invention. In a fiber processing device 10, fibers 12 of a first fiber type and fibers 13 of a second fiber type are respectfully fed through a first feed pipe 14 and a second feed pipe 15 into a first retaining duct 11 and a second retaining duct 11′, respectively, by, e.g., transport air. First fiber type 12 can be, e.g., a multiple-component fiber, in particular bi-component fiber, and second fiber type 13 can be fibers of cellulose acetate, cellulose or carbon fibers. Diverse fiber materials that have a finite length can be provided. With regard to the different fiber materials reference is made to the commonly owned German Patent Application No. DE 102 17 410.5, the disclosure of which is expressly incorporated by reference herein in its entirety. The length of the fibers can preferably be smaller than the length of the filter rod to be produced. Accordingly, this can be between 0.1 mm and 60 mm and, in particular, preferably between 0.2 mm and 10 mm. With fibers produced synthetically, the fiber thickness should be 1 to 20 dtex, preferably 2 to 6 dtex. The average fiber diameter can be in the range of preferably 10 to 40 μm, in particular, 20 to 38 μm and, in particular, preferably between 30 and 35 μm. The fibers are preferably curled, in particular, zigzag shaped, and have 10 arches per 10 mm.

Fibers 12 or 13 are removed from the accumulation area of the fibers of the retaining ducts 11 and 11′ by intake rolls 16 and 16′ and beaten out with a beater roll 17 or 17′ and transferred into first fiber feed duct 19 or second fiber feed duct 19′. The different fiber types 12 or 13 are combined to form a fiber mixture 32 in a combining region 20. Fiber mixture 32 reaches a conveyor duct 21 and can accumulate shortly before intake roll 22 of a carding device or a part of a carding device.

The metering of fiber types 12 and 13 takes place through, e.g., the control of the removal speeds of the fibers by intake rolls 16, 16′ and/or beater roll 17, 17′. Intake rolls 16, 16′ can be embodied to run slowly, such that they convey the fibers against a spring-mounted groove (not shown). The fibers are hereby drawn in and compressed into a thin compact fiber cake (not shown).

The fiber cake conveyed downwards between intake rolls 16, 16′ and groove is subsequently trimmed off or beaten out at the lower end of the groove by respectively one rapidly running beater roll 17, 17′. The fibers are thereby loosened, separated and carried into ducts 19, 19′. A supporting air flow can be used hereby, which is not shown in FIG. 1. At the end of the conveyor duct 21, the fiber mixture is gathered by intake roll 22 and conveyed against groove 23 and subsequently a leaf-spring battery 24. Groove 23 is spring-mounted. A thin, compact fiber cake is produced (not shown) and conveyed between intake roll 22, groove 23 and leaf-spring battery 24 and compacted.

If the fiber cake leaves the effective range of leaf-spring battery 24, it is gathered and taken on by rapidly running roll 25. Rolls 25, 26 and 27 are embodied as or with a teasel or equipped with sawtooth assemblies or trapezoid-tooth assemblies. The roll speeds increase from roll 25 to roll 27.

After the fibers of fiber mixture 32 have been held in the assembly of roll 25 for a rotation of approx. 180°, fibers 32 are transferred tangentially to counter-rotating roll 26. Since roll 26 rotates more quickly than roll 25 and in particular has a finer teasel structure or a finer sawtooth assembly or trapezoid-tooth assembly, a longitudinal alignment, parallelization and separation of the fibers takes place during the transfer.

After fibers 32 have been held on the circumference in the assembly of roll 26 for approx. 180°, fibers 32 are transferred tangentially in turn to counter-rotating roll 27. Since roll 27 rotates more quickly than roll 26 and has, in particular, a finer teasel-like structure or a finer sawtooth assembly or trapezoid-tooth assembly, a longitudinal alignment, parallelization and separation of the fibers again takes place during the transfer. After fibers 32 have been held in the assembly of roll 27 for 180°, fibers 32 are transferred tangentially upwards into an air flow 44 of the channel or suction duct 28. Subsequently, fiber mixture 32 reaches a suction belt 29 of a suction rod conveyor 30. Air flow 44 can additionally be separated from the fiber mixture or fiber/granulate mixture via a lateral suctioning 45 (or 45′ in FIG. 4) before suction rod conveyor 30.

A conventional rod-forming device, such as, e.g., according to FIG. 10 of European Patent Application No. EP 1 464 241 A1, is connected to the suction rod conveyor, which is not shown in the figure. In this regard, the disclosure of EP 1 464 241 A1 is incorporated by reference herein in its entirety. After a fiber cake has been produced on suction belt 29 of suction rod conveyor 30, the fiber cake is usually trimmed, fed to a forming device in order to produce a fiber rod with the desired cross-sectional geometry from the fibers forming from which the fiber cake or fiber web is formed and optionally to wrap the fiber rod with a wrapping material in order subsequently to be cut to length in filter rods.

Instead of a direct injection of fibers 32 into suction duct 28, fibers 32 can be dropped first onto an endless apron and subsequently suctioned into a suction duct according to EP 1 584 248 A1, such that, preferably, one roll more or one roll less is then used in the carding device.

FIG. 2 shows another embodiment according to the invention of a device for producing filter rods, such that, compared to FIG. 1, a ventilator 31 is provided directly following combining area 20. Ventilator 31 generates a transport air flow 42 in conveyor duct 21. Measures can be provided to ensure a closed circulation of the transport air flow such that, e.g., in the lower area of conveyor duct 21 transport air openings are provided, which ensure that transport air is removed from conveyor duct 21 without carrying along fibers, in order then to be fed to the ventilator again.

In FIG. 2, furthermore, a drive belt 36 is provided, which, e.g., indicates a drive of roll 25. Rolls 25 through 27 as well as the other rolls used, however, can also be driven with a direct drive by one motor each.

In contrast to the exemplary embodiment according to FIG. 1, FIG. 2 depicts yet another option, namely feeding a granulate 43 to the fiber mixture. This takes place shortly before the filter material is poured onto a suction belt of a suction rod conveyor 30 in suction duct 28.

To this end, granulate 43 is fed from a granulate container 33 to a drop duct with a metering roll 34. The drop duct ends in a chamber with an accelerating roll 35 that flings the granulate tangentially in the direction of suction rod conveyor 30 into suction duct 28. A good intermixing of the granulate with the fibers thus occurs. A fiber web 41 or a filter material web 41 then forms on a suction belt of the suction rod conveyor 30.

In order to render possible a higher production speed or a higher throughput of material and to increase the number of filter rods per unit of time, it is possible to provide two suction belts 29, 29′, as indicated in FIG. 3 and FIG. 4.

To this end, as indicated in FIG. 3, a suction duct 28 can be divided into two partial ducts 39 and 39′, which are arranged to run essentially parallel each other shortly before suction belts 29, 29′ of suction rod conveyor 30. In FIG. 3, furthermore, injection area 37 for granulate is provided.

According to FIG. 4, two complete suction ducts 28, 28′ are provided that are slightly tilted with respect to one another, in this case at an angle of approx. 3°. Suction ducts 28 and 28′ can be embodied such that they are arranged one behind the other perpendicular to the drawing plane relative to the drawing plane of FIG. 4 so that respectively half the depth or width of rolls 27 or 35 are provided to respectively supply conveyor ducts 28 or 28′ with filter material. Injection area 37 is then provided with a relatively short granulate duct 40 for front conveyor duct 28 relative to the drawing plane of FIG. 4 and with rear conveyor duct 28′ relative to the drawing plane of FIG. 4 with a somewhat longer granulate duct 40′. Accelerator roll 35 can be embodied as a type of brush roll. The granulate is flung into the respective suction duct by centrifugal force and mixes with the fiber stream. It is preferred if the speeds of the mass stream and the granulate fed in are different relative to one another. A good mixture is hereby produced.

Through the structure according to the invention the size of the rod-maker (rod-making machine) for filter production is considerably reduced, since a suction rod conveyor can be arranged directly at the separating device. Moreover, the air consumption is reduced, since the transport stream and mixing process in an otherwise conventional long channel are omitted.

It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.

LIST OF REFERENCE NUMBERS

• • 10 Fiber processing device
  • 11, 11′ Retaining duct
  • 12 First fiber type
  • 13 Second fiber type
  • 14 First feed pipe
  • 15 Second feed pipe
  • 16, 16′ Intake roll
  • 17, 17′ Beater roll
  • 19 First fiber feed duct
  • 19′ Second fiber feed duct
  • 20 Combining area
  • 21 Conveyor duct
  • 22 Intake roll
  • 23 Groove
  • 24 Leaf-spring battery
  • 25 Roll
  • 26 Roll
  • 27 Roll
  • 28, 28′ Suction duct
  • 29, 29′ Suction belt
  • 30 Suction rod conveyor
  • 31 Ventilator
  • 32 Fiber mixture
  • 33 Granulate container
  • 34 Metering roll
  • 35 Accelerator roll
  • 36 Drive belt
  • 37 Injection area
  • 38 Forking
  • 39, 39′ Partial duct
  • 40, 40′ Granulate duct
  • 41 Fiber web
  • 42 Transport air
  • 43 Granulate
  • 44 Conveying direction
  • 45, 45′ Suctioning

Claims

1. A method for producing filter rods of the tobacco-processing industry, comprising: combining and mixing fibers of finite length of two different fiber types; andseparating the combined and mixed fibers,wherein the combining and mixing occurs directly before the separating.

2. The method in accordance with claim 1, wherein the mixing occurs with the combining.

3. The method in accordance with claim 1, wherein, after the separating, the method further comprises forming a fiber web.

4. The method in accordance with claim 1, wherein the separation comprises accelerating the fibers.

5. The method in accordance with claim 4, wherein the accelerating of fibers occurs in or by a teasel.

6. The method in accordance with claim 1, wherein the fibers of two different fiber types are unmixed before the combining and mixing.

7. The method in accordance with claim 6, further comprising accumulating the unmixed fibers before the combining and mixing.

8. The method in accordance with claim 1, further comprising conveying the combined fibers to a separating device by a transport air flow.

9. The method in accordance with claim 8, wherein the separating device comprises several rolls arranged one behind the other, and wherein rotational speeds of the several rolls increase in the fiber conveying direction.

10. The method in accordance with claim 1, wherein the combining and mixing comprises forming a compact fiber cake at an entrance to a separating device.

11. The method in accordance with claim 10, wherein the separating comprises loosening the fibers of the compact fiber cake.

12. A method for producing filter rods of the tobacco-processing industry comprising: accumulating fibers of finite length of at least one fiber type;separating the fibers in a separating device,wherein the separated fibers exiting the separating device have a motion component in a direction toward a conveyor.

13. The method in accordance with claim 12, wherein the motion component is against gravity.

14. The method in accordance with claim 12, wherein the conveyor is a suction rod conveyor.

15. The method in accordance with claim 12, further comprising flinging the separated fibers into a suction duct directly from the separating device.

16. The method in accordance with claim 15, wherein the conveyor is connected to the suction duct.

17. The method in accordance with claim 12, wherein, in a conveying direction downstream of the separating device, the method further comprises mixing fibers with another filter material having a motion component in the direction toward the conveyor.

18. The method in accordance with claim 17, wherein the motion component is against gravity.

19. The method in accordance with claim 15, wherein the suction duct comprises one of two suction ducts arranged next to one another or a division forming two partial suction ducts arranged next to one another.

20. A device for producing filter rods of the tobacco-processing industry, comprising: at least two fiber feed ducts opening into a mixing duct;a separating device connected to the mixing duct; anda conveyor structured and arranged to receive separated fibers of finite length.

21. The device in accordance with claim 20, wherein the conveyor is structured and arranged to receive separated fibers to be poured from the separating device.

22. The device in accordance with claim 20, further comprising a device for generating an air flow in the mixing duct.

23. The device in accordance with claim 20, further comprising retaining ducts arranged upstream of the at least two fiber feed ducts.

24. The device in accordance with claim 20, wherein the at least two fiber feed ducts form retaining ducts.

25. The device in accordance with claim 20, wherein the mixing duct is embodied as a retaining duct.

26. The device in accordance with claim 20, further comprising a ventilator structured and arranged to drive the fibers through the mixing duct.

27. The device in accordance with claim 20, wherein the separating device comprises several rolls arranged one behind the other, and wherein rotational speeds of the several rolls increase in the fiber conveying direction.

28. The device in accordance with claim 27, wherein at least one of the several rolls is embodied in a teasel-like manner.

29. The device in accordance with claim 20, wherein the conveyor is a suction rod conveyor.

30. The device in accordance with claim 29, further comprising a suction duct connected directly to the separating device, wherein the suction duct is aligned essentially vertically and terminates with the conveyor.

31. The device in accordance with claim 30, wherein the suction rod conveyor is arranged at an upper end of the suction duct.

32. The device in accordance with claim 29, wherein the suction rod conveyor comprises one of: two suction rod conveyors or two suction belts.

33. The device in accordance with claim 32, further comprising two suction ducts.

34. The device in accordance with claim 32, further comprising a suction duct divided into two ducts in a fiber conveying direction upstream of the one of the two suction rod conveyors or the two suction belts.