U.S. patent application number 10/815933 was filed with the patent office on 2004-11-25 for method and a continuous rod machine arrangement for producing nonwoven filters.
This patent application is currently assigned to HAUNI Maschinenbau AG. Invention is credited to Arnold, Peter-Franz, Buhl, Alexander, De Boer, Jann, Horn, Sonke, Maurer, Irene, Scherbarth, Thorsten, Wolff, Stephan.
Application Number | 20040235631 10/815933 |
Document ID | / |
Family ID | 33454320 |
Filed Date | 2004-11-25 |
United States Patent
Application |
20040235631 |
Kind Code |
A1 |
Buhl, Alexander ; et
al. |
November 25, 2004 |
Method and a continuous rod machine arrangement for producing
nonwoven filters
Abstract
The invention relates to a method for producing a nonwoven fiber
composite for the manufacture of filters in the tobacco industry,
wherein the method feeds separated fiber materials to a fluidized
bed and the separated filter material inside the fluidized bed are
transported to a rod-forming device, essentially by a transport air
flow flowing in the direction of the rod-forming device and the
filter material is compiled on the rod-forming device prior to
forming the compacted fiber filter elements.
Inventors: |
Buhl, Alexander;
(Robertsdorf, DE) ; De Boer, Jann; (Hamburg,
DE) ; Horn, Sonke; (Geesthacht, DE) ; Maurer,
Irene; (Hamburg, DE) ; Scherbarth, Thorsten;
(Geesthacht, DE) ; Wolff, Stephan; (Glinde,
DE) ; Arnold, Peter-Franz; (Hamburg, DE) |
Correspondence
Address: |
VENABLE, BAETJER, HOWARD AND CIVILETTI, LLP
P.O. BOX 34385
WASHINGTON
DC
20043-9998
US
|
Assignee: |
HAUNI Maschinenbau AG
Hamburg
DE
|
Family ID: |
33454320 |
Appl. No.: |
10/815933 |
Filed: |
April 2, 2004 |
Current U.S.
Class: |
493/39 ; 264/121;
425/82.1; 425/83.1; 493/42 |
Current CPC
Class: |
A24D 3/0208
20130101 |
Class at
Publication: |
493/039 ;
493/042; 264/121; 425/082.1; 425/083.1 |
International
Class: |
A24D 003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 2003 |
EP |
03 007 672.3 |
Jul 7, 2003 |
EP |
03 015 325.8 |
Claims
What is claimed is:
1. A method for producing a nonwoven fiber composite for the
manufacture of filters in the tobacco industry, the method
comprising: feeding separated fiber materials to a fluidized bed;
transporting the separated filter material inside the fluidized bed
to a rod-forming device essentially by a transport air flow flowing
in the direction of the rod-forming device; and compiling the
filter material on the rod-forming device.
2. The method according to claim 1, wherein the filter material
comprises fibers.
3. The method according to claim 3, further comprising providing
fibers of different compositions.
4. The method according to claim 1, wherein the fibers in the
fluidized bed further comprises at least one additive.
5. The method according to claim 1, wherein the separated fibers
have a length of from about 2 to about 100 mm.
6. The method according to claim 1, wherein the average fiber
diameter of the separated fibers is in the range of from about 10
to about 40 .mu.m.
7. The method according to claim 1, wherein the average fiber
diameter of the separated fibers is in the range of from about 20
to about 38 .mu.m.
8. The method according to claim 1, wherein the separated fibers
are synthetic fibers.
9. The method according to claim 8, wherein the fiber strength of
the synthetic fibers is from about 1 to about 20 dtex.
10. The method according to claim 8, wherein the fiber strength of
the synthetic fibers is from about 2 to about 6 dtex.
11. The method according to claim 1, further comprising
successively feeding separated fiber materials of differing
composition to the fluidized bed.
12. The method according to claim 1, wherein the feeding step
further comprises the separating of fibers.
13. The method according to claim 1, wherein the method further
comprises forming a continuous fiber filter rod from the compiled
fibers, and dividing the continuous rod into individual filter
sections.
14. An arrangement of a continuous rod machine for use in the
tobacco industry, comprising: at least one filter-material feeding
device comprising a metering element for dispensing metered amounts
of separated filter material; a continuous-rod forming device; and
a fluidized bed for transporting the filter material from the
filter material feeding device to the continuous rod-forming
device.
15. The continuous rod machine arrangement according to claim 14,
wherein the filter material feeding device further comprises at
least one conveying element.
16. The continuous rod machine arrangement according to claim 14,
wherein the at least one conveying element comprises at least one
roller.
17. The continuous rod machine arrangement according to claim 14,
wherein the filter material feeding device supplies the separated
fibers to the metering element.
18. The continuous rod machine arrangement according to claim 14,
wherein the fluidized bed comprises a filter material directing
channel.
19. The continuous rod machine arrangement according to claim 14,
wherein the fluidized bed is a filter material directing
channel.
20. The continuous rod machine arrangement according to claim 14,
wherein the fluidized bed comprises a curved portion, initially
transporting the fluidized filter material in a downward direction
then transitioning to a horizontal position before subsequently
directing the fluidized filter material in an upward direction.
21. The continuous rod machine arrangement according to claim 20,
wherein the curve comprises an elliptical shape increasing in
radius in the transporting direction.
22. The continuous rod machine arrangement according to claim 14,
wherein the filter material feeding device further comprises a
filter material separating device.
23. The continuous rod machine arrangement according to claim 22,
wherein the filter feeding device separating device comprises a
fiber crusher.
24. The continuous rod machine arrangement according to claim 23,
wherein the fiber crusher comprises an element selected from the
group consisting of at least one cutting drum and at least one
hammer crusher and combinations thereof.
25. The continuous rod machine arrangement according to claims 22,
wherein the filter material feeding device meters the filter
material to the separating device.
26. The continuous rod machine arrangement according to claim 14,
wherein the arrangement further comprises at least two filter
material feeding devices.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of European Patent
Application with Serial No. 03 007 672.3, filed on Apr. 3, 2003 and
European Patent Application with Serial No: 03 015 325.8 filed on
Jul. 7, 2003, the subject matter of which, together with each and
every U.S. and foreign patent and patent application mentioned
below, is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a method for producing nonwoven
fiber material for the manufacture of filters in the tobacco
industry. The invention furthermore relates to a continuous rod
machine for use in the tobacco industry, comprising at least one
filter-material feeding device that supplies metered amounts of
filter material and a continuous rod forming device in which the
filter material can be formed and in particular compiled into a
continuous rod.
[0003] A method for producing a nonwoven fiber composite and a
corresponding continuous rod machine for the manufacture of filters
in the tobacco industry is known from British patent document GB
718 332. According to this document, material cuttings are produced
with a tobacco cutter and these are fed to a continuous-rod
machine, such as cigarette rod machines. The cuttings are
impregnated with a chemical agent to prevent an undesirable taste
and to prevent them from falling out of the end pieces of the
respectively produced filters The cuttings are conveyed with a
roller to the operating range of a spiked feed roller and are then
moved with the spiked feed roller to a conveying belt, so that they
can subsequently be fed to a different spiked roller. The cuttings
are then knocked from this spiked feed roller by a different spiked
or beater roller and supplied to a format device where the
continuous filter rod is formed by wrapping a material web around
the fiber rod. The cuttings consist of paper, cellulose, textile,
synthetic materials and the like and have a texture that is similar
to cut tobacco.
[0004] The shape of the cuttings makes it very difficult to produce
filters with homogeneous characteristics. In addition, the options
of adjusting the filter characteristics are very limited.
SUMMARY OF THE INVENTION
[0005] In contrast, it is the object of the present invention to
provide a method for producing a nonwoven filter material for the
manufacture of filters in the tobacco industry, as well as a
generic continuous rod machine, by means of which extremely
homogeneous filters can be produced and a high variability of the
characteristics of the filter to be produced is possible.
[0006] This object is solved by using a fluidized bed for the
production of filters in the tobacco industry. The fluidized bed,
which can also be called a fluidized bed distributor, can be used
easily and purposely for conveying metered filter material, in
particular separated filter material, in the direction of a
continuous rod machine, wherein an extremely uniform conveying is
possible, thus producing filters with high homogeneity.
[0007] If the fluidized bed is arranged upstream of a continuous
rod machine, in conveying direction of the filter materials, and
the fluidized bed comprises a curved wall that guides the filter
materials, it is particularly easy to separate the used transport
air flow from the filter material. As a result, it is possible to
achieve extremely good continuous rod characteristics for the
compiled filter materials in the continuous rod forming device,
thus resulting in a homogeneous filter. It is advantageous if the
curved wall of the fluidized bed initially points downward, then
changes over to the horizontal position and finally is directed
upward.
[0008] The object is furthermore solved with a method for producing
a nonwoven fiber composite for the manufacture of filters in the
tobacco industry, wherein the method feeds separated fiber
materials to a fluidized bed and the separated filter material
inside the fluidized bed are transported to a rod-forming device,
essentially by a transport air flow flowing in the direction of the
rod-forming device and the filter material is compiled on the
rod-forming device prior to forming the compacted fiber filter
elements.
[0009] Particularly suitable as a continuous rod machine is a
continuous rod conveyor, which comprises an air-permeable conveying
medium, e.g. a conveying belt.
[0010] The method according to the invention makes it possible to
produce an extremely homogeneous nonwoven fiber composite for the
manufacture of filters in the tobacco industry. Thus, the filters
produced from this nonwoven fiber composite are also very
homogeneous. A high degree of variability of the filter
characteristics can furthermore be adjusted if the filter material
includes fibers.
[0011] Extremely homogeneous filter characteristics can be obtained
by using compiled, woven or nonwoven finite fiber material ("finite
fiber(s)") as filter material and by essentially completely
separating the fibers prior to forming a continuous rod from which
the individual filters are subsequently formed. The essentially
complete separation of the finite fibers, in particular, is
extremely important since only separated fibers, which are
subsequently reshaped into a nonwoven fiber composite, allow the
forming of a nonwoven filter with an essentially uniform and
homogeneous density.
[0012] The flow of separated finite fibers resembles the image of a
snow storm, meaning it is a flow of fibers with a homogeneous
static distribution of the fibers with respect to space and time.
In particular, the complete separation of the fibers means that
essentially there are no more connecting groups of fibers. A
composite fiber material, for example with a nonwoven fiber
structure, is created only after the fibers are separated. By
breaking up the fiber groups and separating the fibers into
individual fibers, a nonwoven fiber composite can be formed that
does not contain bridge-type connections and cavities.
[0013] If the separated fibers are transported at least in part by
means of an air flow, the separated fibers can be transported
without forming fiber groups. For one particularly preferred
embodiment of the method according to the invention, the fibers are
separated at least in part with the aid of an air flow, thus
resulting in an extremely high degree of separation. A large volume
of air is used to help separate the fibers. Excess air is then
removed at least partially from the fiber flow in the region of a
fluidized bed.
[0014] A high degree of separation is possible if the fibers are
separated at least in part while passing through the openings of a
device provided with a plurality of openings. Pre-separated fibers
remain essentially separated during the feeding operation if the
fibers are supplied at least in part with an air flow. The
separated fibers and also the fiber groups that are processed prior
to the essentially complete separation of the fibers are primarily
supplied only with transport air and/or an air flow.
[0015] A higher degree of fiber separation is achieved if at least
two separation steps are used. Finite composite fibers are
preferably pre-separated by using a hammer crusher or a bale
breaker. A hammer crusher is used to break up a fiber felt while a
bale breaker is used to break up a fiber bale.
[0016] At least one metering step is provided according to one
preferred modification of the method according to the invention, by
means of which the fiber amount, in particular, can be metered out.
A pre-metering and/or a primary metering can be provided for this.
A rough adjustment of the throughput rate of the fibers to be
processed is possible with the pre-metering, whereas a more precise
adjustment is possible with the primary metering.
[0017] A particularly efficient and quick process sequence is
possible if at least one metering step occurs at the same time as a
separation step.
[0018] Different types of fibers are preferably used, so that
filters with different filtering characteristics can be produced.
Cellulose acetate, cellulose, carbon fibers and multi-component
fibers, especially bi-component fibers, for example, can be
considered for the fiber materials. With respect to the components
in question, reference is made in particular to German patent
document DE 102 17 410.5 commonly owned by the assignee of this
application. DE 102 17 410.5 corresponds to US 2003/0213496 A1.
[0019] The different fiber types are advantageously mixed together,
wherein at least one additive can be mixed in. In particular, the
additive can be a bonding agent such as latex or a granulated
material that is particularly effective for binding cigarette-smoke
components, e.g. activated carbon granulate.
[0020] According to one particularly preferred embodiment of the
method according to the invention, a complete fiber separation
takes place along with or following a second or third metering
step, wherein the separation following a third metering step in
particular is possible with a pre-metering step.
[0021] It is particularly preferable if the fiber length is shorter
than the length of the filter to be produced. With respect to the
filter length, reference is also made German patent document DE 102
17 410.5 commonly owned by the assignee of the present application,
the content of which is incorporated herein by reference. It is
preferred that the fiber length be between 0.1 mm and 30 mm and, in
particular, between 0.2 mm and 10 mm. The filter to be produced has
a standard cigarette-filter length and/or filter segment length in
case of multi-segment cigarette filters. An extremely homogeneous
filter based on the processing according to the invention can be
produced if the average fiber diameter is additionally in the range
of 10 to 40 .mu.m, particularly 20 to 38 .mu.m and especially
preferred between 30 and 35 .mu.m.
[0022] It is preferable if a method for producing filters,
involving a process according to the invention for processing
filter material as described herein, is provided which additionally
is used for forming a continuous fiber rod and dividing the
continuous fiber rod into individual filter rods, such as used in
the tobacco industry.
[0023] According to the method for producing filters in the tobacco
industry, a nonwoven filter is preferably formed from the separated
finite fibers no later than during the forming of the continuous
rod. To form this continuous rod of finite fibers, the fibers are
transported in a continuous flow to a suction belt conveyor, thus
forming a nonwoven fiber composite on the surface of the suction
belt conveyor. The suction belt conveyor is specifically designed
to keep the finite fibers, e.g. with a relatively small diameter,
on the suction belt. Essentially, the continuous rod is formed in
the same way as a continuous tobacco rod. However, respective
measures and variations are introduced for turning the finite fiber
material, which differs in size and structure as compared to
tobacco fibers, into a homogeneous continuous rod. Reference is
made here in particular to European Patent Application No: EP 03
007 675.6, filed on Apr. 3, 2003 and entitled "VERFAHREN UND
EINRICHTUNG ZUR HERSTELLUNG EINES FILTERSTRANGS" [Method and
Machine for Producing a Continuous Filter Rod], commonly owned by
the assignee of the present application.
[0024] Different types of filter materials are preferably supplied
successively in the transport direction of the filter materials to
the fluidized bed, so that a homogeneous mixing is achieved. In
addition, this permits the feeding of many different types of
filter materials. According to one particularly preferred
embodiment of the method according to the invention, the filter
material is separated during the feeding process. In particular, a
transport air flow that flows through the fluidized bed is used for
this. This transport air flow can flow past an apparatus for
feeding filter material to the fluidized bed, which causes filter
material to be separated out of this conveying element and/or
feeding element. The filter material supplied by the feeding
element can be pre-separated completely or only partially ahead of
time, e.g. such as filter material broken or torn by a bale breaker
from the bale.
[0025] According to the invention, the method for producing filters
for use in the tobacco industry involves a method for producing a
nonwoven fiber composite, as described herein, wherein the nonwoven
composite is additionally changed into a continuous filter rod and
the rod is then divided into filter rod sections.
[0026] The object is furthermore solved with an arrangement of a
continuous rod machine for use in the tobacco industry, comprising
at least one filter-material feeding device which comprises a
metering element for dispensing metered amounts of separated filter
material, a continuous-rod forming device, and a fluidized bed for
transporting the filter material from the filter material feeding
device to the continuous rod-forming device.
[0027] The continuous rod machine according to the invention makes
it possible to produce filters with extremely homogeneous
characteristics. The continuous rod machine can produce homogeneous
filter rods without many involved separating devices if the filter
material feeding device is designed to supply filter material with
the aid of at least one conveying element, in particular a roller,
from a filter material supply to the fluidized bed. A transport air
flow and/or conveying air flow preferably serves to remove and
separate the filter materials supplied by the conveying element to
the fluidized bed. Thus, the filter material feeding device also
meets a separating function.
[0028] Separated fibers or essentially separated fibers can
preferably be supplied to the fiber material supply, so that no
further separating step for feeding the filter material is
required. In addition, the feeding of separated fibers results in
the production of an extremely homogeneous filter rod with good
filter characteristics. According to one preferred embodiment of
the invention, a channel is installed upstream of the continuous
rod device and follows the fluidized bed downstream in filter
material conveying direction. As a result of this design of the
continuous filter rod machine, the supplied filter material
essentially does not lose its homogeneity and/or no final mixing of
the different filter materials occurs in conveying the material
after the fluidized bed.
[0029] It is preferable if the fluidized bed, at least in part,
takes the form of a channel. A very simple and effective control of
the amount of conveyed composite material in the fluidized bed can
be achieved if the fluidized bed is curved in the conveying
direction of the filter material, such that the fluidized bed
initially points downward, then levels off to become horizontal and
finally points in upward direction. In this case, only the amount
of transport air and/or the strength of the transport air needs to
be adjusted and/or controlled. Preferably, the fluidized bed has an
elliptical shape, for which the curvature increases in the
downstream transporting direction. In general, the fluidized bed
can be a fluidized bed such as the one described in German patent
document DE 33 01 031 C2, the contents of which are hereby
incorporated by reference.
[0030] For a particularly preferred embodiment of the continuous
rod machine according to the invention, the filter material feeding
device comprises a separating device that separates a nonwoven of a
starting material into individual fibers. In that case, cellulose
fibers can easily be used for the filter production. The separating
device advantageously uses a fiber crusher that comprises a cutting
drum or a hammer crusher. A fiber crusher of this type is produced,
for example, by the company Diatec.
[0031] The filter material is preferably metered via the filter
material feed to the separating device. For this, the filter
material is initially present in the form of a nonwoven composite
or mass. In this instance, the advance of the nonwoven material to
the separating device controls the metering of the filter material
which is supplied to the fluidized bed.
[0032] According to one particularly preferred embodiment of the
invention, at least two filter material feeding devices are
provided, which require two different filter material feeding
devices, wherein one device comprises a fiber crusher, for example,
and the other one a conveying element that conveys fibers from a
fiber supply, containing essentially separated fibers, to a
fluidized bed. Additional fiber material feeding devices can also
be provided, e.g. for feeding granulate and particularly activated
carbon granulate to the fluidized bed. With respect to the fiber
crusher, U.S. Pat. No. 4,673,136 A, describes a fiber crusher of
suitable type.
[0033] The object is furthermore solved with an arrangement for
processing filter material for use in the manufacture of filters in
the tobacco industry, wherein the arrangement comprises at least
one device for separating the filter material and at least one
metering device. At least one means for supplying the filter
material from the at least one metering device to the at least one
separating device is also provided, wherein the processing
arrangement is modified for processing filter material with finite
fibers and wherein the at least one device for separating the
finite fibers permits an essentially complete separation.
[0034] A filter having extremely homogeneous characteristics can be
realized with the arrangement according to the invention and
correspondingly processed filter material.
[0035] The feeding means preferably comprise an air flow, which
makes it possible to produce an even more homogeneous filter.
[0036] One particularly preferred embodiment of the arrangement
according to the invention for processing fibers requires an air
flow through and/or in the arrangement for separating the fibers,
which results in a high degree of separation. The separating device
of a particularly effective processing arrangement is provided with
a plurality of openings through which the separated fibers can
individually exit the device.
[0037] A particularly easy to realize metering device comprises a
drop chute from which a rotating roller removes the fibers. If a
pair of feed rollers are provided in the lower region of the
metering device, the filter material can be metered out in a
careful manner.
[0038] A particularly good and homogeneous separation occurs if the
separating device separates the fibers through a joint operation of
at least one rotating element, at least one element provided with
passages and an air flow. The metering device and/or the at least
one metering device preferably also has a separating function,
which can further increase the degree of separation of the complete
processing arrangement. Different materials and also different
fibers can be processed if a mixing device is preferably provided,
wherein the fibers can be cellulose fibers, fibers of a
thermoplastic strength, flax fibers, hemp fibers, linseed fibers,
sheep's wool fibers and cotton fibers or can be multi-component
fibers, as previously shown in the above. The mixing device
preferably permits an additional separation and/or metering of the
fibers, thus making possible an extremely compact arrangement
design. The arrangement for one particularly preferred embodiment
of the invention is designed such that finite fibers with a length
shorter than that of the filter to be produced can be processed.
The arrangement is furthermore designed for processing natural
finite fibers with an average fiber diameter in the range of 10 to
40 .mu.m, in particular 20 to 38 .mu.m, wherein a particularly
preferred diameter is in the range of 30 to 35 .mu.m. The fiber
strength of synthetic fibers is between 1 and 20 dtex, in
particular between 2 to 6 dtex.
[0039] According to the invention, a filter production machine
comprises a processing arrangement as described in the above.
[0040] A filter according to the invention is produced with one of
the above-described methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The invention is described in the following by referring to
the drawings, to which we otherwise refer with respect to all
details not mentioned specifically in the text. Shown are in:
[0042] FIG. 1 is a schematic block diagram of the several sequences
for processing filter material;
[0043] FIG. 2 is a schematic cross-sectional side view
representation of one arrangement for the separation of filter
material from a mass of filter material;
[0044] FIG. 3 is a schematic cross-sectional side view
representation of one embodiment of a pre-metering device for the
controlled metering of material;
[0045] FIG. 4 is a schematic cross-sectional side view
representation of one embodiment of a primary metering device for
the controlled metering of material;
[0046] FIG. 5 is a three-dimensional schematic representation of a
mixing device for the mixing of different filter materials;
[0047] FIG. 6 is a schematic cross-sectional side view
representation of one arrangement of a metering device containing a
filter material separating device;
[0048] FIG. 7 is a schematic cross-sectional side view
representation of one arrangement of a primary metering device
containing another embodiment of a filter material separating
device;
[0049] FIG. 8 is a schematic cross-sectional side view
representation of one arrangement of a primary metering device
containing another embodiment of a filter material separating
device;
[0050] FIG. 9 is a three-dimensional schematic representation of
another embodiment of a filter material separating device;
[0051] FIG. 10 is a side perspective view of one arrangement of a
continuous filter rod making apparatus;
[0052] FIG. 11 is a top down perspective view of the continuous
filter rod making machine apparatus of FIG. 10 as viewed from the
`A` location;
[0053] FIG. 12 is a end on schematic perspective view of the
continuous filter rod making machine apparatus of FIG. 10 as viewed
from the `B` location;
[0054] FIG. 13 is a schematic three-dimensional view of yet another
embodiment of a filter material separating device;
[0055] FIG. 14 is a schematic cross-sectional side view of a
different embodiment of a filter material separating device
separating device;
[0056] FIG. 15 is a schematic representation of the separating
device of FIG. 14, additionally showing a granulate feed
station;
[0057] FIG. 16 is a schematic representation of the separating
device of FIG. 15, showing the granulate feed station at an
alternate location;
[0058] FIG. 17 is a schematic side view of an arrangement of a
continuous rod machine for making a continuous of filter
material;
[0059] FIG. 18 is a schematic top down view of the continuous rod
machine arrangement of FIG. 17;
[0060] FIG. 19 is a schematic three-dimensional representation of
another exemplary embodiment of a continuous rod machine
arrangement;
[0061] FIG. 20 is a schematic side view representation of another
exemplary embodiment of a continuous rod machine arrangement;
[0062] FIG. 21 is a schematic enlarged detail side view of the
section `A` of the arrangement of FIG. 20; and
[0063] FIG. 22 is a schematic detail side view of an embodiment of
a metering and separating arrangement.
DETAILED DESCRIPTION OF THE DRAWINGS
[0064] FIG. 1 is a block diagram of the method steps, ranging from
a fiber processing to a continuous rod production, for producing a
filter for use in the tobacco industry. A variable process sequence
is possible owing to the different types of process sequences that
can be used. The example in FIG. 1 shows initially a fiber
preparation step 1, during which above all the fiber materials that
are delivered in a solidly compressed form are changed to an
airy-cottony state. Individual fibers can also be generated in
addition to these fiber groups. The fiber preparation 1 is
realized, for example, with an arrangement as shown in FIG. 2,
which is known per se. The forms that solidly compressed fiber 10
may be delivered include, for example, fiber bales and fiber mats
as well as fiber felt. Fiber bales are normally opened with a bale
breaker and fiber mats and/or fiber felt are opened with a hammer
crusher.
[0065] Non-compressed fiber materials that are densely packaged are
also loosened up during the fiber preparation stage and puffed up
to form an airy, cottony state. A bale breaker for fiber materials
can be purchased, for example, from the company Trutzschler GmbH,
Germany and a hammer crusher for fiber materials can be purchased
from the company Kamas.
[0066] A pre-metering step 2, which can optionally be used with
this exemplary embodiment, can represent a second step. The
arrangement according to FIG. 3 permits a pre-metering step 2,
wherein the pre-metering functions to roughly batch the fiber
material and further separate it, such that the groups and/or the
densely packed fibers are further loosened up, wherein additional
separated fibers can develop at this point as well. In place of the
pre-metering step 2, it is also possible to realize a primary
metering and/or metering step 4 by itself. The condition of the
material received from the fiber preparation 1 determines whether a
pre-metering 2 step is required. The goal of the metering 4 and/or
the pre-metering 2 is to realize a defined, stable and uniform mass
flow of fibers and additionally, in part, also a pre-separation.
The metering step 4 leads to a further separation of the fiber
groups. Prior to the metering step 4, a mixing and/or metering step
3 can also be provided. During this step 3, several filter
materials, as indicated in FIG. 1 with the paths from two or more
fiber processors 1 leading to the box 3, and if necessary an
additive, such as a bonding agent or activated carbon granulate,
can also be mixed in.
[0067] The method can furthermore be realized with differently
configured and/or identically configured in parallel processing and
metering lines, so that several different types of fiber materials
can be processed and metered in parallel. The goal of the mixing
operation is to achieve a homogeneous mixing of the individual
fiber components and the different additives. A device as shown in
FIG. 5 can be used for the mixing and/or metering. A primary
metering step, for example, can be realized with a device as shown
in FIG. 4.
[0068] During the mixing and/or metering step, the different fiber
materials can be mixed continuously or discontinuously. A
continuous mixing device 111, for example, is shown in FIG. 5,
wherein the mixing device 111 also functions as intermediate
storage for fiber materials. Not only is it possible to mix
different fibers during this mixing and/or metering step, but
additives can also be mixed in. These additives serve to bond
together the fibers and/or to influence the filtration
characteristics of the fiber filter.
[0069] The discharge from the mixing device 111 is defined, which
results in a metering function. It may be possible to omit the
primary metering 4 by using a mixing and/or metering 5. Following
the metering 4 stage or the mixing and/or metering 5 stage, the
fiber material is fed to a separating step 6. The goal for the
separating is a total break-up of the remaining fiber groups into
individual fibers, so that the fibers can be regrouped in a
following continuous rod production step 7, such that an optimum
nonwoven fiber structure without bridge-type connections and
cavities can develop. It is important in this connection that an
individual fiber can fit itself against other fibers to form a
nonwoven structure. Thus, according to FIG. 1, it is possible to
use up to three metering steps. Additional metering stages can also
precede the initial separation process 1.
[0070] The fiber flow leaving the separating device(s) consists of
individual fibers carried along by air and/or in an air flow. The
appearance of the air flow carrying along fibers or a fiber-loaded
air flow resembles a snow storm. For producing a continuous rod
from the separated fibers, the fibers can be supplied, for example
with a fluidized bed, to a suction belt of a special suction-belt
conveyor. During the forming of the continuous rod 7, a continuous
rod with constant cross section is created, wherein the cross
section in particular has a constant square shape and a uniform
density is created at the same time. The fibers are present in a
nonwoven form at least up to the rod formation. The finished fiber
filter rod has sufficient hardness, tensile resistance, weight
consistency, retention and further processing ability.
[0071] FIG. 2 shows a fiber preparation arrangement 114. A fiber
felt 10 is conveyed with feed rollers 11 to the operating range of
a hammer crusher 13 with hammers 12. The hammers 12 of this hammer
crusher 13 are located inside a housing 14. The hammers 12 hammer
the fiber felt in the tear-off region 15, thus forming the fiber
groups 16. The fiber groups 16 are transported further with an air
flow 17 inside a pipe 18. An air flow 19 loaded with fiber groups
is created. Individual fibers, not shown, can also be generated at
this location. The hammers 12 of the hammer crusher 13 rotate in a
downward direction so that the fibers are ejected in the direction
of rotation of the crusher 13 and tangentially from housing 14.
[0072] A pre-metering device 113 is shown schematically in FIG. 3.
An air flow loaded with fiber material 41 is supplied to a
separator 20, which separates the fiber material 41 from the air
flow so that the fiber material 42 drops through an chute 21 into a
storage container 22. The lower part of the storage container 22
houses two spiked feed rollers 23. The spiked feed rollers 23
rotate slowly and deliver the fiber material to a third spiked feed
roller 24. The third spiked feed roller 24 rotates quickly and
tears fiber groups from the fiber material. These fiber groups
travel to a funnel 25 by sliding downward. A rotary vane feeder 26
is arranged at the lower end of the funnel 25. The fiber groups
slide into the cells of the rotary vane feeder 26 and are moved
into the channel 27. An air flow 28 flows inside a channel 27 and
carries along the fibers and/or fiber groups delivered to the
channel 27. The air flow 28 also carries along individual fibers
returned from the process, which are then supplied along with the
fiber groups. The air flow 28 is loaded with fibers and fiber
groups. A fiber/fiber group mixture 29 is transported with the aid
of the air flow. The mass throughput can be adjusted by varying the
speed of the rotating members, namely the spiked feed rollers 23
and 24 as well as that of the rotary vane feeder 26, so that a
pre-metering can be realized.
[0073] FIG. 4 shows a schematic representation of a metering device
112 for realizing a primary metering operation. The fiber/fiber
group mixture 29 is transported with an air flow to a separator 30,
e.g. a rotary separator. There, the fiber/fiber group 31 is
separated from the air flow, not shown. The separated out fiber
material 31 travels to an accumulation chute 32 and drops downward
through this chute to feed rollers 34. Several roller pairs or a
pair of feed belts, not shown, and/or several feed belt pairs, not
shown, can also be provided. Vibration elements 33 are provided for
one section of the accumulation chute 32, which permit a continuous
feeding of the fiber/fiber groups mixture 31 to the feed rollers
34.
[0074] The feed rollers 34 convey the fiber material 31 between the
strippers 35 and into the metering channel 36 formed by the
strippers. A rotating roller 37, e.g. a spiked feed roller, tears
the fibers from the fiber material 31 and delivers these to a
channel 38. An air flow 39 is present in the channel 38, which
picks up the fibers and/or the fiber material 40 and
correspondingly transports it in the direction of air flow 39. The
fiber mass 31 flow, into the metering channel 36, is preset by the
speed of the feed rollers 34.
[0075] FIG. 5 shows a three-dimensional, schematic representation
of a mixing device 111. Different fiber materials 43 and 44 as well
as additional fiber materials or additives 45 in liquid or solid
phase are fed into a mixing chamber 46. The fiber materials can be
cellulose fibers, fibers with a thermoplastic coating, flax fibers,
hemp fibers, linseed fibers, sheep's wool fibers, cotton fibers or
multi-component and in particular bi-component fibers, having a
length shorter than the length of the filter to be produced and a
thickness, for example, in the range of 25 to 30 .mu.m. Cellulose
fibers of the type "stora fluff EF untreated" by the company Stora
Enso Pulp AB can be used, for example, which have an average cross
section of 30 .mu.m and a length of between 0.4 and 7.2 mm. For the
synthetic fibers such as the bi-component fiber, it is possible to
use fibers with a length of 6 mm of the type Trevira 255 3.0 dtex
HM by the company Trevira GmbH. These fibers have a diameter of 25
.mu.m. Cellulose acetate fibers, polypropylene fibers, polyethylene
fibers and polyethylene terephthalat fibers can also be used for
the synthetic fibers. Materials that influence the taste and/or
smoke can furthermore be used as additives, such as activated
carbon granulate or flavoring agents, as well as bonding agents
that make the fibers stick together.
[0076] The fiber material 43 and 44 and/or the respective additives
45 that are fed into the mixing chamber 46 are supplied to rollers
50-52, which rotate with suitable speeds during the filling and the
mixing operation. It is preferable if the position of rollers 50-52
can be adjusted in a horizontal as well as a vertical direction. As
a result, the axial spacing, not shown, of the rollers can be
adjusted relative to each other, wherein several rollers can
furthermore be arranged on different levels. The components to be
mixed are picked up by the rollers 50-52, are accelerated and
churned up inside the mixing chamber 46. The churning causes the
mixing of the components. The amount of time the mixing components
spend inside the mixing chamber 46 can be adjusted with the
geometric structure of a screen 47. In addition, the dwell time for
the components to be mixed inside the mixing chamber 46 can be
determined with a closing shutter (not shown) for closing the
openings of the screen 47 partially or completely.
[0077] The fiber mixture and/or the fiber/additive mixture 53 is
conveyed through openings of the screen 47 into a chamber 54, which
can take place continuously or at intervals. An air flow 55 flows
through the chamber 54, which preferably can pivot. The air flow 55
picks up the mixture 53 and pulls it along. The loaded air flow 56
leaves the chamber 54 and conveys the mixture 53 further.
[0078] FIG. 6 shows a schematic representation of a separating
device 115 in connection with a metering device 112. The metering
device 112 essentially corresponds to the metering device shown in
FIG. 4. However, the vibration elements 33 are shown as separate
sections of the drop chute 32 and the strippers 35 differ slightly
from those shown in FIG. 4. The fiber material, not shown, pulled
from the metering channel 36 by the rotating roller 37 is fed
directly to a separating chamber 61. The mass throughput in the
metering channel 36 is determined by the speed of the feed rollers
34. Air flows through the complete separating device. This air flow
133 and 68 is generated by a reduced pressure caused on the one
hand by an air flow 72 inside an exhaust pipe 71 and, on the other
hand, by the flow in a suction belt conveyor that is arranged at a
fluidized bed end 69 and is not shown in this Figure. The air flows
133 and 68 may also be augmented by an additional in-put of
air.
[0079] Inside the separating chamber 61, the fibers and/or the
fiber groups move under the effect of gravity and the influence of
air flow 133 and/or the intake of air 63 through ventilation
openings 62 to the region of rollers 60. The individual rollers 60
are aligned in the row and pick up the non-separated fibers (and of
course also the partially separated fibers that are present),
accelerate these fibers and beat these against a screen 64 of the
separating chamber 61. Perforated sheets or round bar grids can
also be used in place of a screen with exit surfaces. 21.
[0080] As a result of mechanical stress, the fiber groups are
separated into individual fibers and finally pass through the
screen 64. Following a sufficient separation, the fibers are picked
up by the flow 133 through the screen and are guided and/or
suctioned through the screen 64. The speed of rollers 60 and the
area of openings 64 as well as the intensity of the flow 133
determine the mass throughput of the separating chamber 61.
[0081] The separated fibers 65 travel to a fluidized bed 66 where
they are picked up by an air flow 68 that can be augmented from an
air nozzle, designed as a nozzle lip 67, and are moved along the
fluidized bed 66. Several nozzle lips 67 can also be provided. The
low pressure at the fluidized bed end 69 primarily ensures a
sufficient flow 133 and 68 for transporting the separated fibers
within chamber 61 and toward the fluidized bed end 69. At the
fluidized bed end 69, the air flow 68 is, in part, separated from
the fiber flow by a flow divider 70 and travels to the exhaust pipe
71. The flows 133 and 68, created by the low pressure and the
nozzle lip 67, remove air from the separating chamber 61. Fresh air
63 flows through the ventilation openings 62 into the separating
chamber 61.
[0082] The separated fibers, not shown, are transported in the
fluidized bed region with the air flow 68, which includes air flow
133 previously used for the separation. This air flow moves in
nearly a vertical direction until the fluidized bed is reached and
subsequently moves along the fluidized bed. The flow 68 can be
supplemented with additional air flows and/or air flow from one or
more nozzles 67.
[0083] A suction belt conveyor follows the fluidized bed 66, but is
not shown in this Figure (see also in particular FIGS. 10 and 12).
The separated fibers are compiled on the suction belt, wherein two
or more suction belts can also be used.
[0084] FIG. 7 shows a different embodiment of a separating device
according to the invention. In contrast to the embodiment according
to FIG. 6, only one roller 60 is provided for this exemplary
embodiment. In addition, several air flows 74 are provided inside
the separating chamber 61, which are generated with air nozzles 73.
Several air nozzles 73 can also be used, as shown in FIG. 7. These
not only can be arranged on the outside surface of the chamber, but
can also be distributed in the separation chamber 61. The air flows
guide the fibers to the roller 60, wherein several rollers can also
be used in place of the one roller. The function of roller 60
and/or the several rollers 60 corresponds to the function described
in FIG. 6. The air flows 74 cause an increased swirling inside the
separation chamber 61, thus improving the separation of the fibers
as compared to the embodiment shown in FIG. 6. The separated fibers
65 correspondingly travel through the screen 64 as shown in FIG.
6.
[0085] FIG. 8 shows a different embodiment of a separating device
115 according to the invention. The air flow in this case is
generated by the low pressure at the end of the fluidized bed 69
and the air flow 68 flowing from the nozzle lip 67, wherein several
nozzle lips can also be used. The main air flow starts above the
screen 64 and passes by the rows of stirring mechanisms 82 and 83,
as well as the screen 64. Following this, the main air flow travels
to the fluidized bed region 66 and passes through the fluidized bed
66 to its end 69.
[0086] The essentially non-separated fiber material and/or the
fiber/fiber group mixture 31 enters the partially shown housing
above the screen 64. Instead of the position shown in FIG. 8, this
housing can also be inclined at an angle, e.g. at 45.degree. to the
horizontal line. As a result of gravity as well as the main air
flow, not shown, the fiber/fiber group mixture 31 travels to the
region of stirring mechanisms 82 and 83. Stirring mechanisms 82 and
83 are arranged in rows (not shown) and that consist of
successively arranged stirring rods that drive a suitable stirring
mechanism. The stirring mechanisms are displaced at an angle of
90.degree. relative to each other, wherein other displacement
angles can be provided as well. The non-separated fiber groups are
torn apart by the rotating stirring mechanisms, are then
accelerated and tossed against the screen 64 of the housing. A
perforated sheet or a round bar grid can also be used in place of
the screen 64. The fiber groups and/or the fiber group mixtures 31
are tossed against the screen 64 until they have been separated
into individual fibers and with the main air flow have passed
through the screen 64. Subsequently, fibers 75 travel along the
fluidized bed 66, as for the previous exemplary embodiments, and to
a suction belt conveyor that is also not shown in FIG. 8. The
separating device shown in FIG. 8 is known, at least with respect
to the rows of stirring mechanisms 82 and 83, from European Patent
Document EP 0 616 056 B1 owned by M+J Fibretech A/S, Denmark, the
contents of which are incorporated fully into the present patent
application.
[0087] A different exemplary embodiment of the separating device
115 according to the invention is shown in a schematic,
three-dimensional representation in FIG. 9. The essentially
non-separated fiber material and/or fiber/fiber group mixture, not
shown, is transported by air flows 76 to screening drums 78, via
openings 77 on the side of housing 79. The fiber material is blown
in the direction of the longitudinal axes into the screening drums
78. A circular flow 80 is generated by blowing the fiber material
from both sides in counter-clockwise direction into the drum. This
circular flow 80 is superimposed by a normal flow, not shown,
and/or a flow that is essentially perpendicular thereto and is
caused by a low pressure at the fluidized bed end 69 and an air
flow 68. The low pressure at the fluidized bed end 69 is generated
by a low pressure in a suction belt conveyor, not shown herein,
which is arranged at the fluidized bed end 69, as well as by an air
flow 72 flowing through the exhaust pipe 71. The normal flow starts
above the screening drums 78 and passes through the screening drums
78 via the drum sleeve openings. The normal flow then travels to
the fluidized bed region 66 and passes through this region to the
end 69 where a portion of the normal flow is separated from the
fibers at the wedge 70.
[0088] The non-separated fiber material inside the drums 78 is
deposited on the inside sleeve surfaces of drums 78. The drums 78
rotate in a clockwise direction 81 as viewed in FIG. 9. The
essentially non-separated fiber material deposited on the drum
sleeve surfaces is then fed by the rotating drums to separating
rollers 85. The separating rollers 85 rotate counter-clockwise in
the direction 84 as viewed in FIG. 9. Alternatively, they could
also rotate in the clockwise direction. The separating rollers 85
and/or the needle rollers pick up the non-separated fiber groups
and tear these apart as well as accelerate them. The fiber groups
are tossed against the inside drum sleeve surface of drums 78 until
they have separated into individual fibers and have passed through
the drum sleeve openings, meaning until they have been picked up by
the air flow (the normal flow) and are guided and/or sucked through
the screening drum 78. A drum with perforated sheets or round bar
grids can also be used in place of the screening drum 78.
[0089] The fibers and/or separated fibers are picked up by an air
flow and guided and/or sucked through the radial openings in the
drum. The air flow 76 conveys the fibers in downward direction to
the fluidized bed. As soon as the fiber-loaded flow arrives at the
fluidized bed, it is deflected and guided along the curved
fluidized bed. As a result of the gravitational forces acting upon
the fibers, the fibers move toward the curved guide wall and flow
to the suction belt conveyor. The air flowing along above the
fibers is separated at the wedge and/or separator 70 and discharged
via the exhaust pipe 71.
[0090] The respective fiber flows 75 are shown schematically in
FIG. 9. Separated fibers are picked up by an air flow 68 that exits
at the nozzle lip 67 and are also supplied to the fluidized bed end
with the air flow 68, in the same way as the separated fibers that
are fed to the fluidized bed 66. Several nozzle lips can also be
provided.
[0091] Fiber groups that are not separated or not completely
separated during a single passage through the drums 78 are supplied
via the circular flow 80 to the respectively parallel drum 78. For
the separation, the fibers will flow through the openings 132 of
the screening drums 78, wherein essentially only separated fibers
can pass through the openings 132. The openings 132 are thus
designed such that only separated fibers can pass through.
[0092] The separating device shown in FIG. 9 corresponds at least
in part to the one disclosed in International Patent Publication WO
01/54873 A1 and U.S. Pat. No. 4,640,810 A. assigned to Scanweb of
Denmark and/or the United States. The content disclosed in the
above-referenced patent documents are incorporated fully into the
disclosure of the present patent application.
[0093] FIG. 10 shows a schematic representation of a continuous rod
machine 110. FIG. 11 shows a portion of a continuous rod machine
110, in a view from above and along the arrow A. FIG. 12 shows a
view from the side of the continuous rod machine 110 according to
FIG. 10 in the direction of arrow B.
[0094] With reference to FIGS. 10-12, a non-separated fiber
material travels via the accumulation chute 32 to the metering
device 34, which in this example is represented by a pair of feed
rollers 34 with a rotating roller 37. In FIG. 11, the direction of
the material feed-in 100 is downward in the drawing plane, as shown
schematically therein. The non-separated fiber material is
separated in the separating chamber 61. The air flow at the
fluidized bed 66, which is generated by the air flow in the exhaust
pipe 71 and the air flow 72' at the suction belt conveyor 89,
conveys the separated fibers 65 (FIG. 12). According to FIG. 11,
the direction of the air flow 72 in the exhaust pipe 71 is upward
and out of the drawing plane. The air flow 72 also removes excess
fibers. The air flow 72' functions to hold in place the fibers 65
that are compiled on the suction belt 89 (FIGS. 10 and 12).
[0095] The separated fibers 65 move on the fluidized bed 66 in the
direction toward the fluidized bed end 69 where a suction belt
conveyor 89 is arranged, as shown in the FIGS. 10-12. As a result
of the continuous suctioning out of air, a low pressure is present
at the suction belt conveyor 89. The suctioning out of air is shown
schematically with the air flow 72'. The low pressure pulls the
separated fibers 65 against the air-permeable suction belt of
suction belt conveyor 89 and keeps them there.
[0096] The separated fibers 65 are correspondingly compiled on the
air-permeable suction belt of the suction belt conveyor 89. The
suction belt 116 moves in the direction of the continuous rod
machine 110, meaning to the left in FIG. 10. A fiber cake and/or
fiber flow 86, FIG. 10, forms on the suction belt, which increases
nearly linearly in size in the direction toward the continuous rod
machine 110. The compiled fiber flow 86 varies in thickness and is
trimmed with a trimming device 88 to reach a uniform size. The
trimming device 88 can be a mechanical device, e.g. trimming disks
or plates, or a pneumatic device such as air nozzles. The
mechanical trimming is known per se from continuous cigarette rod
machines. For the pneumatic trimming, a nozzle that discharges an
air flow is arranged horizontally at the end of the fiber flow 86
and tears out a portion of the fiber flow 86, so that excess fibers
87 are removed, wherein a pointed nozzle or a flat nozzle can be
used as well.
[0097] Following the trimming operation, the fiber flow 86 is
divided into a trimmed continuous fiber rod 90 and a rod of excess
fibers 87. A nozzle jet, not shown, can also be used to pick up and
tear off all fibers below a trimming dimension. The excess fibers
are returned to the fiber preparation process and are later on used
to form another continuous fiber rod.
[0098] The trimmed fiber rod 90 is held against the suction belt
116 and is moved in the direction of the continuous rod machine
110. The trimmed fiber rod 90 is a loose nonwoven fiber composite
which is compacted with the aid of a compacting belt 92. However, a
roller can also be used in place of the compacting belt 92, or
several belts and/or rollers can be used. As shown in FIG. 11, the
fiber cake is furthermore also compacted on the side, wherein FIG.
11 shows the compacting belts 101 moving toward each other at a
conical angle while operated at the speed of the suction belt with
the fiber cake. The serrated or toothed shape of the compacting
belts 101 creates zones of varying density in the compacted fiber
cake. The filter rod 91 is later on cut in the zones with higher
density. The higher fiber density in the filter end region ensures
a more compact consistency of the fibers in this sensitive zone
and, additionally, makes it easier to process the filter rods. A
compacting belt 92 is provided for the compacting in the vertical
direction, wherein rollers can also be provided in place of the
compacting belt 92.
[0099] The trimmed and compacted fiber rod 91 is transferred to the
continuous rod machine 110. For the transfer, the compacted fiber
rod 91 is lifted off the suction belt 116 and the rod 91 is then
deposited on a format belt of the continuous rod machine 110,
wherein the format belt is not shown in the Figures. The format
belt can be a standard format belt, such as the ones used for a
standard continuous filter rod machine and/or continuous cigarette
rod machine. The transfer is aided by a nozzle 93, which directs an
air flow 94 from the top onto the compacted fiber rod 91.
[0100] A continuous fiber filter rod 95 is formed in the continuous
rod machine 110, wherein a bobbin 98 wraps a wrapping material web
99 in the standard way around the fiber material. A certain
internal pressure builds up in the fiber filter rod 95 as a result
of volume reduction and the shaping of the compacted fiber rod 91
into a circular and/or oval form during the wrapping with the
wrapping material web 99. In a curing device 96, bonding components
contained in the fiber mixture are heated on the surface and
slightly melted. The outer layers of bi-component fibers can
correspondingly be melted, so that a bond is created between the
fibers. For this, we point in particular to German Patent
Application DE 102 17 410.5, commonly owned by the assignee of the
present application. The curing device 96 can also be a microwave
heater, a laser heater, heating plates and/or sliding contacts. As
a result of heating up the bonding components, the individual
fibers in the fiber rod will bond and melt together on the surface.
During the cooling of the fiber rod, the melted regions harden once
more and the resulting grid structure imparts stability and
hardness to the continuous fiber rod. Following this, the cured
fiber filter rod 95 is cut into individual rod sections 97. The
curing of the fiber filter can also take place following the
cutting into fiber filter rod sections 97.
[0101] The air flow 102 shown in FIG. 12 also functions to
transport the fiber materials, in the same way as the air flows in
previous examples.
[0102] FIG. 13 shows a three-dimensional representation of a fifth
embodiment of the separating device according to the invention,
which is similar to the one shown in FIG. 9. A granulate metering
device 120 is provided in addition to the embodiment shown in FIG.
9. The granulate metering device 120 pours granulate across the
complete width of the separating device 115 into the separating
device 115 between the screening drums 78. In the region of
screening drums 78, the poured-in granulate 121 mixes with the
fibers leaving the screening drums 78. A flowing mixture of
separated fibers and granulate 75 is thus created, which is
conveyed by the air flow on the fluidized bed to the suction belt
conveyor, arranged in the conveying direction behind the suction
belt end 69.
[0103] FIG. 14 shows a schematic cross sectional representation of
a different separating device 115 according to the invention. The
air flow is improved in this embodiment, so that more uniform air
flows 75 and 75' are created. An air flow 122 enters the
arrangement in the upper region of the screening drum 78. The
separated fibers leaving the screening drums 78 travel to the
channels 123 and 124 and are moved downward with the respective air
flow to the region of fluidized bed 66. The fiber flows 75 are
combined to form a fiber flow 75' in the lower region of the
fluidized bed. In this region, a large portion of the transport air
is separated from the fiber flow, which is shown with the air flow
122'. For this, an exhaust pipe 125 is provided in the rolling area
126 of the fluidized bed 66. Once the two fiber flows 75 are
combined, the fiber flow 75' flows into a channel formed by the
fluidized bed 66 and the separator 127. At this location, a
nonwoven fiber composite may already have formed, depending on the
process sequence, or the fibers may still be separated. The fiber
flow 75' is subsequently transported with the aid of the low
pressure at the suction belt conveyor 89 to the fluidized bed end
69 and the suction belt conveyor 89.
[0104] The schematic sectional representation in FIG. 15 is similar
to the one shown in FIG. 14. However, a granulate metering device
120 is arranged above the screening drums 78 in a modification as
compared to the embodiment shown in FIG. 14. Granulate 121 is
supplied with two pipes to the respective screening drums 78. The
resulting fiber/granulate flows 128, which are transported in the
channels 123 and 124, are combined in the lower region of fluidized
bed 66 to form a fiber/granulate flow 128'.
[0105] FIG. 16 represents a different embodiment according to the
invention of a separating device 115. In this case, the granulate
121 from the granulate metering device 120 is supplied near the
fluidized bed end 69. The granulate 121 reaches an acceleration
element 129, which can be a roller, a brush or a nozzle. The
accelerated granulate 121 travels through the line 130 to the
fluidized bed, meaning to a vertical fluidized bed section 131.
[0106] FIG. 17 schematically shows an arrangement of continuous
filter rod making machine according to one embodiment of the
invention in a view from the side. The method to be realized with
this machine is used for the manufacture of cigarette filters of
suitable fibrous materials of biological and/or synthetic origin,
as well as other materials such as granulates. The fiber materials
can be the same ones described above. In particular, we reference
European application EP 03 004 594.2 entitled "ZIGARETTENFILTER UND
VERFAHREN ZUR HERSTELLUNG DESSELBEN" [Cigarette Filter and Method
for Producing Same], commonly owned by the assignee of the present
application. Filters can be produced from the fibers of a single
type of material as well as from an optional mixture of fibers
composed of different materials or compositions. Filters produced
from the fibers of a single type of material require only one
filter-material feeding device 201 and/or 209 for the continuous
filter rod machine as shown in FIG. 17, however more than one
feeding device may be employed if desired. The produced filters,
which can also be called fiber filters, are in part biodegradable,
depending on the fiber mixture. The goal is to have a round or oval
filter rod shape and/or the filter rod form at the end of the
production process.
[0107] The device shown in FIG. 17 processes two different types of
fibers, which are fed at two metering locations to the fluidized
bed 216 from two filter material feeding devices, namely a metered
opener 209 and a fiber crusher 201. The first metering location is
at the transition between fiber crusher 201 and a fiber channel
215, not shown, after which directly follows downstream the
fluidized bed 216. The base material is a raw cellulose material
such as cellulose acetate fibers in the form of a nonwoven fiber
composite 223, wound around a bobbin 202. The nonwoven fiber
composite 223 is fed via a feed roller pair 204, driven by a motor
203, to the fiber crusher 201. A rotating cutting drum 207, driven
by a motor 205, disrupts or ruptures the cellulose sheets or
nonwoven cellulose composite 223 at high speed. The cutting drum
207 is provided with a plurality of cutting disks. The plurality of
cutting disks on cutting drum 207 can be seen more clearly in FIG.
18, which provides a schematic view from above the arrangement of
equipment shown in FIG. 17. The cellulose fibers are fed via
separator sheets 208 to a strong transport air flow 206.
[0108] The second metering location is placed at location 214 in
the region of the fiber channel 215 where the output for the
metered opener 209 is located. FIG. 19 shows that a bale opener 226
is installed in front of the metered opener 209. A respective bale
opener can be purchased, for example, from the company Trutzschler
GmbH, Germany. The fiber material in the form of bales or stacks is
separated or essentially separated in the bale opener 226. The
fiber material can comprise, for example, bi-component fibers. The
separated and/or pre-separated fibers are fed via transport air and
a pipeline 210 to the metered opener 209. In the metered opener
209, the fibers are separated by the screen 228 from the transport
air and fall into a reservoir chute 211.
[0109] The reservoir and/or the reservoir chute 211 into which the
fibers are discharged and/or drop serves to balance out fluctuating
conveying amounts of the bale openers that may result when a bale
is changed. The reservoir 211 is thus preferred to make possible a
continuous metering of fibers in a production process. Rotating
needle transport rollers 212 move the fibers to the needle metering
roller 213, wherein the mass throughput can be adjusted by varying
the speed of the rotating elements. At one separation point 214,
the fibers are combed out of the needles by the transport air flow
206 and are completely separated. This can also be supported by
respective separator sheets, which are not shown herein. The fibers
are subsequently conveyed in fiber channel 215 and moved to a
fluidized bed 216.
[0110] The mass throughput of the fiber crusher 201 is controlled
by controlling the advance of the material in the form of the
nonwoven cellulose 223 to the fiber crusher 201.
[0111] Additional metering locations for supplying additional
fibers and/or solid materials such as powders or granulates to the
fluidized bed can also be provided, but are not shown in this
representation.
[0112] The transport air flow 206 flows through the two feed
channels 229 and 230, shown in FIG. 17, so that initially different
filter materials are conveyed in each feed channel. The feed
channels are separated by a dividing wall 231. The two feed
channels 229 and 230 are combined at location 232 to form fiber
channel 215, which is preferably rectangular in shape. Starting at
this point, the fiber channel is called a fluidized bed 216. The at
least two fiber materials combine in the fluidized bed 216 to form
a homogeneous fiber mixture.
[0113] The fluidized bed 216 describes a uniform curve function
that is tangentially adapted to the fiber channel 215. Above the
lowest or bottom location 217 up to the vertical intake wall of the
suction belt channel 218, the curve describes a quarter of an
ellipse. The sharpest curvature is at the end of the fluidized bed
216 where the fluidized bed turns into the suction belt channel
218. As a result of the curve radius becoming increasingly more
narrow in connection with the fiber speed, the fibers are
increasingly deposited on the lower sheet metal wall or fluidized
bed wall 227 owing to centrifugal force. In the region of the
sharpest curvature 219 the fibers encounter the highest centrifugal
force. Directly adjacent to this location 219, the fluidized bed
216 again separates into two channels. The lower, fiber-carrying
channel empties into the suction channel 218.
[0114] The upper channel, which in the ideal case does not contain
fibers, is used for discharging the large transport air flow from
the system. Fibers that have not been discharged can be separated
in a separator, not shown, and can be reused. The transport air
flow 206 in part is generated by a ventilator connected to the
suction belt conveyor 221, which creates a low pressure in the
suction belt conveyor and the fluidized bed. The necessary air flow
206 for operating the fiber crusher 201 and/or the metered opener
209 is not generated solely by the suction belt ventilator.
Additionally required transport air flow 206 can be generated by a
second ventilator connected to the fluidized bed separator 220, if
desired.
[0115] The ratio of suctioned-off air volume at the separation
location 219 is influenced by the desired air speeds and the
cross-sectional capacity. The air volume flowing in both lines can
also be adjusted by regulating the ventilators following the
separation.
[0116] A fiber cake and/or a nonwoven fiber composite forms on the
suction belt conveyor 221, which is continuously conveyed further
by the suction belt to a continuous filter rod machine 222, as
shown in FIGS. 18 and 19. The filter is subsequently produced in
the standard manner, e.g. on the machine called KDF, which is
described in European Patent Application 03 007 675.5 and entitled
"VERFAHREN UND EINRICHTUNG ZUR HERSTELLUNG EINES FILTERSTRANGS"
[Method and Arrangement for Producing a Continuous Filter Rod], and
commonly owned by the assignee of the present application. The
contents of this German patent application is incorporated in its
entirety into the present patent application.
[0117] To produce filters from finite fibers comprising at least
two different types of fibers, one of which is preferably a
bi-component fiber, the different fiber types are supplied via
different metering systems to different locations in the feed
channel of a fluidized bed or directly to a fluidized bed. The
transport air for the fibers can be generated with a ventilator for
the suction belt conveyor connected to the fluidized bed or a
ventilator at the fluidized bed separator, or both.
[0118] FIG. 18 shows a continuous filter rod 225 that is produced
by the rod making machine and is conveyed in the direction
indicated by the arrow.
[0119] FIG. 19 shows one embodiment of an arrangement of machines
to be used for a continuous rod machine. The fluidized bed 216 is
followed by a continuous filter rod machine 222, which has a
similar design as a cigarette machine, but which has been adapted
to handle the different characteristics of the filter materials
(different types of fiber materials and/or granulate or powder) as
compared to tobacco fibers.
[0120] FIG. 20 schematically shows yet another embodiment of a
continuous rod apparatus. In this configuration, the bonding
fibers, e.g. the bi-component fibers, are fed at a first location
to the filter production process, whereas filler fibers such as
cellulose fibers from a fiber mat or nonwoven fibers 303 are
supplied from a bobbin 302 to the bonding fiber flow at a fiber
crusher rotor and/or a cutting drum 307 where they are mixed
together with the aid of the cutting drum 307.
[0121] The mode of operation is as follows: In a metering and
processing device 309, bonding fibers are metered and processed.
The metering and processing device 309 is arranged upstream of a
fiber crusher 301. The metering and processing device 309 releases
bonding fibers 323, FIG. 21, from the roller 328 to an air flow
306. The bonding fibers can be multi-component fibers, in
particular bi-component fibers. For this, we refer to German patent
DE 102 17 410.5, commonly owned by the assignee of the present
application.
[0122] As shown in FIG. 21, the air flow 306 in the channel 326 and
also in the fluidized bed channel 316 is generated either
completely or essentially by the rotation of cutting drum 307 in
the channel region 325 of channel 326. The air flow 306 is
furthermore aided and removed from the process by the ventilator
and/or suction air blower on the suction belt conveyor 321 and the
ventilator and/or circulation fan that suctions air from the
fluidized bed separator 320. The blower and/or ventilator 329
optionally supports the air flow 306.
[0123] The air flow 306 that is loaded with bonding fibers 323
travels to the channel region 325 of the cutting drum 307. The feed
rollers 304 convey a fiber mat and/or a nonwoven fiber composite or
structure 303 from the bobbin 302 to the cutting drum 307. The
cutting drum 307 separates the nonwoven fiber composite 303 into
individual fibers 324. The individual fibers 324 are thrown from
the cutting drum 307 into the channel region 325 of the channel 326
where they mixed with the bonding fibers 323. This fiber mixture
327 is transported with the aid of the air flow 306 in the channel
326 to the fluidized bed channel 316. In this exemplary
arrangement, it is possible to add a granulate material to the
fiber mixture 327 by means of a feed chute 330 that is installed
between the channel 326 and the fluidized bed channel 316.
[0124] The bonding fibers 323 can also consist of a mixture of
different fibers, e.g. a mixture of polypropylene fibers and
bi-component fibers. The metering and processing device 309 is
suitable for mixing and metering these fibers.
[0125] FIG. 21 shows an enlarged schematic detailed view of
location A of the arrangement shown in FIG. 20, wherein the housing
around the fiber crusher 301 has been removed. The mixing of the
bi-component fibers 323 and/or the bonding fibers 323 and the
individual fibers 324 with the aid of the cutting drum 307 is shown
particularly well. The conveying direction 323' of the bonding
fibers 323 and the conveying direction 327' of the fiber mixture
327 is also shown. In addition, the conveying direction 310 of the
nonwoven mat 303 is shown.
[0126] The bonding fibers 323 and, alternatively, other optional
fiber mixtures such as a mixture of bi-component bonding fibers and
filler fibers of polypropylene are filled into the chute 331.
Another embodiment of a metering and processing device 309 is shown
schematically and in further detail in FIG. 22.
[0127] Fibers 323 move downward inside the chute 331. At the lower
end of the chute 331, the fibers 323 are gripped by the slowly
moving feed roller 332. The feed roller 332 conveys the fibers 323
against an indentation 333 that is positioned resiliently. In the
process, the fibers 323 are drawn in and compacted to form a thin
fiber cake, not shown herein.
[0128] The fiber cake that is conveyed downward between feed roller
332 and indentation 333 is subsequently cut off at the lower end of
the indentation 333 by the fast-rotating beater roller 334. In the
process, the fibers 323 are loosened up, are separated and are fed
with the air flow 339 into the chute 335.
[0129] The ventilator 338 generates a circular air flow 339. The
air flow 339 is guided inside the channel 340 and subsequently past
the feed roller 332. In the process, the air flow 339 cleans the
feed roller 332. Subsequently, the air flow 339 picks up fibers 323
and transports these downward inside the chute 335.
[0130] Following the redirecting of the chute 335 in the horizontal
direction. The chute 335 is designed in the region 336 in such a
way that the chute walls on the top and on the bottom have a
comb-type shape. That is to say, these walls contains recesses
through which the air can flow. The air flow 339 in this region 336
is separated via the combs, which are not shown in FIG. 22, from
the fibers 323. The air flow 339 in the comb-type region 336 is
suctioned out by the ventilator 338 via the pipes 337, thus closing
the air flow 339 cycle.
[0131] The fibers separated from the air flow 339 are picked up at
the end of chute 335, namely behind the comb-type region 336 by a
slowly rotating feed roller 343 and are conveyed in the direction
of the indentation 341 and subsequently against a leaf-spring
accumulator 342. The indentation 341 is positioned so as to
elastically flex. A thin, compact fiber cake is thus created, which
is not shown, and is conveyed and compacted between the feed roller
343, the indentation 341 and the leaf-spring accumulator 342.
[0132] As the fiber cake leaves the operating region of the
leaf-spring accumulator 342, it is gripped and taken over by a
fast-moving roller 344. The rollers 344, 345 and 328 are provided
with saw-tooth or trapezoidal tooth coverings. The roller speeds
increase from roller 344 to roller 328.
[0133] The fibers 323 are held in the roller 344 covering during
one rotation of approximately 180.degree.. Subsequently, the fibers
323 are transferred tangentially to the roller 345 that rotates in
a counter-clockwise direction. Since roller 345 rotates faster than
roller 344 and, in particular, is provided with a fmer saw-tooth or
trapezoidal tooth covering, the fibers are oriented longitudinally
parallel to each other during the transfer.
[0134] After the fibers 323 have been held in the covering of
roller 345 for an approximately 180.degree. rotation, the fibers
323 are transferred tangentially to roller 328 that also rotates in
a counter-clockwise direction. Since roller 328 rotates faster than
roller 345 and, in particular, is provided with a finer saw-tooth
or trapezoidal tooth covering, the fibers are oriented in parallel
and in the longitudinal direction during the transfer. After the
fibers 323 are held in the covering of roller 328 for an
approximate rotation of 180.degree., the fibers 323 are discharged
tangentially upward into the air flow 306 in the channel 326.
[0135] The embodiments illustrated and discussed in this
specification are intended only to teach those skilled in the art
the best way known to the inventors to make and use the invention.
Nothing in this specification should be considered as limiting the
scope of the present invention. All examples presented are
representative and non-limiting. The above-described embodiments of
the invention may be modified or varied, without departing from the
invention, as appreciated by those skilled in the art in light of
the above teachings. It is therefore to be understood that, within
the scope of the claims and their equivalents, the invention may be
practiced otherwise than as specifically described.
* * * * *