U.S. patent application number 14/240180 was filed with the patent office on 2014-06-19 for methods and apparatuses for manufacture of smoking article filters.
The applicant listed for this patent is Gary Fallon, Kie Seon Park, Robert Whiffen. Invention is credited to Gary Fallon, Kie Seon Park, Robert Whiffen.
Application Number | 20140171281 14/240180 |
Document ID | / |
Family ID | 44838921 |
Filed Date | 2014-06-19 |
United States Patent
Application |
20140171281 |
Kind Code |
A1 |
Park; Kie Seon ; et
al. |
June 19, 2014 |
Methods and Apparatuses for Manufacture of Smoking Article
Filters
Abstract
An apparatus for manufacturing a filter rod for a cigarette or
other smoking article having a pattern formed in relief on the
outer surface thereof. The apparatus comprises a passage including
a portion configured to receive and compress filter material to
form a filter rod and a belt extending along the passage to convey
filter material through the passage. The apparatus includes a
patterned relief surface configured to impress a relief pattern on
a surface of a filter rod as it is formed within the passage.
Inventors: |
Park; Kie Seon; (London,
GB) ; Fallon; Gary; (London, GB) ; Whiffen;
Robert; (London, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Park; Kie Seon
Fallon; Gary
Whiffen; Robert |
London
London
London |
|
GB
GB
GB |
|
|
Family ID: |
44838921 |
Appl. No.: |
14/240180 |
Filed: |
July 24, 2012 |
PCT Filed: |
July 24, 2012 |
PCT NO: |
PCT/EP2012/064474 |
371 Date: |
February 21, 2014 |
Current U.S.
Class: |
493/42 |
Current CPC
Class: |
A24D 3/0258 20130101;
A24D 3/0233 20130101 |
Class at
Publication: |
493/42 |
International
Class: |
A24D 3/02 20060101
A24D003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2011 |
GB |
GB1114956.4 |
Claims
1. An apparatus for manufacturing a filter rod for a cigarette or
other smoking article having a pattern formed in relief on the
outer surface thereof, the apparatus comprising: a passage
including a portion configured to receive and compress filter
material to form a filter rod; and a belt extending along the
passage to convey filter material through the passage; wherein the
apparatus includes a patterned relief surface configured to impress
a relief pattern on a surface of a filter rod as it is formed
within the passage.
2. An apparatus according to claim 1 wherein the relief surface is
formed on the belt such that the belt engages the filter material
and impresses the relief pattern on the surface of the filter rod
as it passes through the passage.
3. An apparatus according to claim 2 wherein the belt comprises a
plurality of plates hingedly coupled end-to-end.
4. An apparatus according to claim 3 wherein the front and rear
edges of each plate which are hingedly coupled to the adjacent
plates, are formed with a corresponding tessellating and/or
saw-tooth configuration.
5. An apparatus according to claim 3 or claim 4 wherein the hinged
connection between the plates comprises a flexible cord or a
plurality of hinge pins.
6. An apparatus according to any of claims 3-5 wherein the belt is
driven over a plurality of guide rollers, wherein at least one of
the guide rollers has a faceted outer surface and the belt is in
registration with the at least one guide roller such that the
plates of the endless belt lie flat on a facet of the at least one
guide roller as the belt passes over said guide roller.
7. An apparatus according to claim 2 wherein the belt comprises a
flexible band with a layer of resilient material formed thereon,
the patterned relief surface being provided in the resilient
material layer.
8. An apparatus according to claim 1 wherein the relief surface is
formed on an inner surface of the passage such that the filter
material engages the relief surface of the passage and the relief
pattern is impressed into the surface of the filter rod as the
filter rod passes through the passage.
9. An apparatus according to any preceding claim wherein the
passage is configured to heat the filter tow material as is passes
therethrough.
10. An apparatus according to claim 9 wherein the passage includes
at least one inlet tube to allow steam to be introduced into the
interior of the passage to heat the filter tow material.
11. An apparatus according to claim 9 or claim 10 wherein the
passage comprises a double wall structure along at least part of
its length, comprising an outer wall and an inner wall spaced from
the outer wall to define a cavity therebetween.
12. An apparatus according to any of claims 9-11 wherein the
passage includes at least one heating element to heat the filter
tow material within the passage, wherein the heating element(s) may
comprise electrical heating element(s).
13. An apparatus according to any preceding claim further
comprising a pressing member configured to impart an inward
pressing force on the belt and/or filter rod as the filter rod is
formed in the passage.
14. A method of manufacturing a filter rod for a cigarette or other
smoking article using a filter rod manufacturing apparatus as
defined in any preceding claim wherein the passage includes a first
open end for introduction of filter material and a second open end
for expulsion of a formed filter rod, the passage narrowing between
the first end and the second end so that as filter material is
conveyed through the passage, it is compressed to form a filter
rod, the method comprising: feeding loose filter tow material onto
the belt; conveying the filter tow material on the belt through the
passage from the first open end to the second open end and thereby
compressing the filter tow material to form a filter rod; and
impressing a relief pattern on a surface of the filter rod as it
passes through the passage.
15. A method according to claim 14 wherein the relief surface is
formed on the belt, the method further comprising the relief
pattern being impressed on the surface of the filter rod by the
patterned relief surface of the belt.
16. An apparatus according to claim 15 wherein an inner surface of
the passage includes a relief surface, the method further
comprising the relief pattern being impressed on the surface of the
filter rod by the patterned relief surface on the inner surface of
the passage.
Description
[0001] The present invention relates to a method and apparatus for
producing filters and filter rods for use in the manufacture of
smoking articles.
[0002] Filter materials are formed into rods during manufacture and
such rods may be cut into smaller units for the application of
filter tips to smoking articles. Existing methods and apparatuses
of producing filter rods can produce filter rods with relief
patterns, such as grooves, on their outer surface and include
forming a filter rod and subsequently forming a pattern/grooves
into the outer surface of the filter rod using a post-processing
technique. An alternative existing method of forming filter rods
with a relief pattern in their outer surface includes creating the
desired pattern in a plug wrap and then wrapping the filter
material in the shaped plug wrap so that the filter material
conforms to the applied shape of the outer plug wrap. In all cases,
the filter rods are formed using existing an method and apparatus,
and the patterned shape for the filter is performed in a separate
earlier or later step.
[0003] In accordance with various embodiments of the invention,
there is provided an apparatus for manufacturing a filter rod for a
cigarette or other smoking article having a pattern formed in
relief on the outer surface thereof, the apparatus comprising, a
passage including a portion configured to receive and compress
filter material to form a filter rod and a belt extending along the
passage to convey filter material through the passage, wherein the
apparatus includes a patterned relief surface configured to impress
the relief pattern on a surface of a filter rod as it is formed
within the passage.
[0004] The relief surface may be formed on the belt such that the
belt engages the filter material and impresses the relief pattern
on the surface of the filter rod as it passes through the passage.
The belt may comprise a plurality of plates hingedly coupled
end-to-end, and at least one of the plates may be metallic.
Furthermore, at least one of the plates may include a
wear-resistant and/or non-stick coating.
[0005] The front and rear edges of each plate which are hingedly
coupled to the adjacent plates, may be formed with a corresponding
tessellating and/or saw-tooth configuration. The hinged connection
between the plates may comprise a flexible cord or a plurality of
hinge pins.
[0006] The belt may comprise a plurality of plates having
respective patterned relief surfaces which are spaced
intermittently between plates without a patterned relief surface
such that the resulting filter rod includes an impressed relief
pattern on its outer surface at spaced intervals along its
length.
[0007] The belt may be driven over a plurality of guide rollers,
wherein at least one of the guide rollers may have a faceted outer
surface and the belt may be in registration with the at least one
guide roller such that the plates of the endless belt lie flat on a
facet of the at least one guide roller as the belt passes over said
guide roller.
[0008] The facets of the at least one guide roller may include a
surface relief pattern corresponding to the patterned relief
surface of the plates of the belt such that the patterned relief
surface of the plates of the belt cooperate with the surface relief
pattern on the facets of the at least one guide roller as the belt
passes over said guide roller.
[0009] The belt may comprise a flexible band with a layer of
resilient material formed thereon, and the patterned relief surface
may be provided in the resilient material layer. The resilient
material layer may be made of at least one of rubber or
plastic.
[0010] In an alternative embodiment, the relief surface may be
formed on an inner surface of the passage such that the filter
material engages the relief surface and the relief pattern is
impressed into the filter rod as the filter rod passes through the
passage. Such relief surface may comprise one or more projections
on an inner wall of the passage. Such projection(s) may be elongate
rib(s) extending substantially longitudinally along at least part
of the length of the passage. Alternatively, the or each projection
may comprise nodes on an inner wall of the passage, for example,
convex, pointed, pyramidal, square or frusto-conical/pyramidal
protrusions.
[0011] The passage may be configured to heat the filter tow
material as is passes therethrough. For example, the passage may
include at least one inlet tube to allow steam to be introduced
into the interior of the passage. Such inlet tube(s) may be formed
in the side wall of the passage between distal first and second
ends thereof. Alternatively, or in addition, the passage may
include one or more heating elements formed integrally with the
passage or provided on the passage. Such heating element(s) may
comprise electrical heating element(s).
[0012] The passage may comprise a double wall structure along at
least part of its length. The double wall structure may comprise an
outer wall and an inner wall spaced from the outer wall to define a
cavity therebetween. The inner wall may be perforated. The outer
wall may include at least one inlet tube to allow steam to be
introduced into the cavity between the outer and inner walls and,
in an embodiment where the inner wall is perforated, to allow steam
into interior of the passage. Alternatively, the inner wall may
omit any perforations.
[0013] The apparatus may be configured such that the belt is formed
into a tolled up state as it passes through the passage, such that
the lateral edges of the belt are disposed proximate each other.
The belt edges may be close to but spaced from each other, in
abutment, or may overlap each other in said rolled up configuration
of the belt. The passage may include a pressing member configured
to impart an inward pressing force on the belt and/or filter rod as
the filter rod is formed in the passage. Such a member may comprise
a mechanism, which may include a sprung arm, and/or a roller biased
inwardly towards the centre of the passage. The member/mechanism
may be formed on in inside wall of the passage and may be provided
at the top centre of the passage.
[0014] The belt or the passage may include a patterned relief
surface configured to impress a grooved pattern on the outer
surface of the filter rod as it is formed in the passage.
[0015] Also provided is a method of manufacturing a filter rod for
a cigarette or other smoking article using a filter rod
manufacturing apparatus as defined above wherein the passage
includes a first open end for introduction of filter material and a
second open end for expulsion of a formed filter rod, the passage
narrowing between the first end and the second end so that as
filter material is conveyed through the passage, it is compressed
to form a filter rod, the method comprising feeding loose filter
tow material onto the belt, conveying the filter tow material on
the belt through the passage from the first open end to the second
open end and thereby compressing the filter tow material to form a
filter rod, and impressing a relief pattern on a surface of the
filter rod as it passes through the passage.
[0016] The relief surface may be formed on the belt, and the method
may further comprise the relief pattern being impressed on the
surface of the filter rod by the patterned relief surface of the
belt.
[0017] Alternatively, an inner surface of the passage may include
the relief surface, and the method may further comprise the relief
pattern being impressed on the surface of the filter rod by the
patterned relief surface on in the inner surface of the
passage.
[0018] The method may comprise feeding a plug wrap onto the belt
and feeding the loose filter tow material onto the plug wrap, such
that the formed filter rod is circumscribed by the plug wrap and
the impressed relief pattern is formed on the filter rod through
the plug wrap. Alternatively, the method may comprise
circumscribing a plug wrap around the formed filter rod after it
has exited from the passage. Yet further, the method may comprise
feeding the filter tow material directly onto the belt such that
the impressed pattern in the resulting filter rod is formed
directly on the filter tow material without any plug wrap around
the outer surface thereof.
[0019] A plasticiser may be entrained with the filter tow material,
and the method may further comprise introducing heat and/or steam
to the passage in order to activate and/or accelerate the reaction
of the plasticiser with the filter tow material. The plasticiser
may be entrained with the filter tow material in a ratio of at
least 8% by weight to dry weight of filter tow material, and may be
between 8-18%, and may be between 12-18%.
[0020] Embodiments of the invention are shown, by way of example
only, in FIGS. 2 to 14 of the accompanying drawings, in which:
[0021] FIG. 1 shows an existing filter rod forming apparatus;
[0022] FIG. 2 shows a filter rod forming apparatus according to a
first embodiment of the invention;
[0023] FIG. 3 shows an enlarged view of a section of the garniture
belt of the apparatus of FIG. 2;
[0024] FIG. 4 shows a cross-section of the garniture belt of the
apparatus of FIG. 2, in a rolled-up state;
[0025] FIG. 5 shows an enlarged view of a section of garniture belt
of a filter rod forming apparatus according to a second embodiment
of the invention;
[0026] FIG. 6 shows an enlarged view of a section of garniture belt
of a filter rod forming apparatus according to a third embodiment
of the invention;
[0027] FIG. 7 shows an enlarged view of a section of garniture belt
of a filter rod forming apparatus according to a fourth embodiment
of the invention;
[0028] FIG. 8 shows a filter rod forming apparatus according to a
fifth embodiment of the invention;
[0029] FIG. 9A shows a cross-sectional view of the apparatus of
FIG. 8 along the line X-X;
[0030] FIG. 9B shows a cross-sectional view of the apparatus of
FIG. 8 along the line Y-Y;
[0031] FIG. 10 shows a filter rod forming apparatus according to a
sixth embodiment of the invention;
[0032] FIG. 11 shows a filter rod forming apparatus according to a
seventh embodiment of the invention;
[0033] FIG. 12 shows a cross-sectional view of the apparatus of
FIG. 11 along the line Z-Z;
[0034] FIG. 13 shows a filter rod forming apparatus according to an
eighth embodiment of the invention; and
[0035] FIG. 14 shows a cross-sectional view of the apparatus of
FIG. 13 along the line W-W;
[0036] Referring now to FIG. 1, an existing apparatus 10 for
producing a filter rod is shown and comprises a `garniture` 11 and
a guide funnel 12. The garniture 11 is a passage in the form of a
duct or tube, having a wide entrance opening 11a and a narrow exit
opening 11b. The garniture 11 narrows between the wide entrance
opening 11a and the narrow exit opening 11b at a `tow guide`
portion 11c. The rear section 11d of the garniture 11 between the
tow guide 11c and the narrow exit opening 11b is substantially
constant in cross-section along its length (as shown in FIG. 1),
but in some apparatuses may continue to taper but more gently than
the tow guide section 11c. The tow guide section 11c transitions to
the rear section 11d at a portion known as a `tongue`. The tongue
may include a section of reduced taper than the tow guide portion.
The garniture 11 is generally circular in cross-section. A
continuous `garniture belt` 13 extends through the garniture 11 and
over a plurality of guide rollers 14 and is driven to be conveyed
around the rollers 14 in the direction shown by arrows `A`. A plug
wrap `P` may be fed from a spool 15 onto the upper surface of the
garniture belt 13 and is conveyed through the garniture 11 by the
moving garniture belt 13. As the plug wrap P travels though the
garniture 11, the shape of the tapered tow guide 11c (and tongue)
deforms the garniture belt 13 and plug wrap P thereon such that, in
cross-section, the plug wrap P goes from being flat (as it is on
the spool 15) when it enters the wide entrance opening 11a of the
garniture 11, to a closed circle as it leaves the narrow exit
opening 11b of the garniture 11, completely surrounding the formed
filter rod. As the plug wrap P is wrapped around the filter
material, the edges meet to form a seam at an upper portion of the
garniture 11. This seam may then be glued (or the plug wrap may be
pre-glued where the seam is to be formed).
[0037] A section of the upper portion of the garniture 11 may
comprise a heating bar (not shown) to heat and activate the glue at
the seam of the plug wrap to adhere the plug wrap in place around
the filter material. Such a heater bar may be curved and sit in a
correspondingly shaped recess in the garniture 11 to form a
continuous outer wall thereof. Furthermore, in some existing
apparatuses, hot melt glue is applied to the plug wrap which needs
to be cooled to set and adhere the seam together. In such cases,
the heater bar would not be present and a cooling bar may be
provided instead.
[0038] In use, loose filter tow material (not shown), such as loose
cellulose acetate fibre, is fed into the funnel 12 as shown by
arrow `B` and is guided into the tow guide 11c of the garniture 11
by a `transport jet` of compressed air from a jet nozzle (not
shown). The filter tow material is conveyed through the tapering
tow guide 11c on the plug wrap P so that the loose filter tow
material is formed into a more compacted rod as it emerges from the
distal narrow end 11b. The transport jet and guide funnel 12 serve
to guide the loose filter tow material into the wide entrance
opening 11a, and the transport jet provides a continuous blast of
compressed air which gathers the loose filter tow material into a
lightly compressed state and propels the lightly compressed filter
tow material into the garniture 11.
[0039] As the filter tow material travels through the garniture 11
and is compressed, the plug wrap P is folded around the outside of
the compressed cylinder of filter tow material and glue is applied
to the over-lapping seam and heated to activate the glue, such that
when the filter tow material exits though the narrow exit opening
11b of the garniture 11, the filter tow material is formed into a
compressed cylindrical filter rod 16 enveloped by an outer plug
wrap. This existing process produces filter rods with a smooth
outer surface. If a relief pattern such as grooves are to be formed
in the filter rods, these must either be formed in a separate
second process requiring further machinery and production
time/complexity, or the plug wrap P must first be shaped (e.g.
crimped) prior to being fed into the garniture 11 so that the
filter tow material conforms to the shape of the plug wrap P,
again, involving further machinery and production
time/complexity.
[0040] A method and apparatus 110 according to a first embodiment
of the invention, for producing filter rods having a relief pattern
on an outer surface thereof, is shown in FIGS. 2-4 and, as with the
existing method/apparatus described above, comprises a guide duct
or `garniture` 111 having a wide entrance 111a and narrower exit
111b, and a guide funnel 112, the features of which are the same
and/or function similarly as those described above in reference to
FIG. 1. The apparatus 110 also includes a continuous belt or
`garniture belt` 113 which extends over a plurality of guide
rollers 114 and is driven to be conveyed around the rollers 114 in
the direction shown by arrows `C` in FIG. 2. Also as with the
existing filter rod producing apparatus, plug wrap `P` is fed from
a spool 115 onto the upper surface of the garniture belt 113 which
conveys it through the garniture 111 which deforms the garniture
belt 113 and plug wrap P thereon such that, in cross-section, the
plug wrap P goes from being flat (as it is on the spool 115) when
it enters the wide entrance opening 111a of the garniture 111, to a
closed circle as it leaves the narrow exit opening 111b of the
garniture 111, completely surrounding the formed filter rod.
[0041] The apparatus 110 of the first embodiment of the present
invention differs from the existing apparatus 10 described above in
the construction of the garniture belt 113 and the form of the
guide rollers 114. In an existing apparatus 10, the garniture belt
13 is a continuous flexible belt of material such as canvas or
other woven fibre. In the apparatus 110 of the first embodiment of
the invention however, the garniture belt 113 is formed of a
plurality of plates 117 hingedly connected to each other
end-to-end. The construction of the garniture belt 113 can be seen
more clearly in the enlarged portion of FIG. 2 and in FIG. 3, which
shows the plates 117 are formed with a series of parallel ridges
118 and saw-toothed front and rear edges 119, 120. The plates 117
are connected together with saw-toothed front edge 119 tessellating
with the saw-tooth rear edge 120 of the preceding plate 117, and a
flexible connecting element 121 extending through apertures formed
transversely through the saw-tooth sections 119, 120. The
connecting element can be a flexible thread such as, but not
limited to, plastic thread, metal wire, or fabric thread.
[0042] In order for the plates 117 to pass through the garniture
111, the plates 117 are elastically deformable from their flat
state (shown in FIG. 3) to a rolled-up state (see FIG. 4) in which
they are rolled about their longitudinal front/rear axis. In order
for this deformation to occur, the connecting element 121 may be
flexible to also deform between a straight configuration when the
plates 117 are in their flat state to a curved configuration when
the plates 117 are in their rolled-up state.
[0043] In order to minimise the stress on the plates 117 as they
are continuously conveyed around the belt path of the garniture
111, the rollers 114 do not have a rounded/continuously curved
outer surface as in an existing apparatus 10, but instead may have
a series of flat faces 122 which are the same length as that of the
plates 117. The garniture belt 113 length, position and dimensions
of the rollers 114 and dimensions of the flat faces 122 thereof are
configured such that as the garniture belt 113 passes over each
roller 114, each plate 117 lies on a flat face 122 of the roller
with the connecting element 121 aligned with the edge formed
between adjacent flat faces 122. Therefore, the plates 117 are not
forced to deform by curving about an axis transverse to their
front/rear direction, as they would if they were to pass over
round-faced rollers.
[0044] In use, as with an existing filter-rod forming apparatus,
loose filter tow material (not shown), such as cellulose acetate,
is fed into the funnel 112 as shown by arrow `D` and is guided into
the garniture 111 by a jet of compressed air from a jet nozzle (not
shown). As the garniture belt 113 enters and is conveyed through
the garniture 111, the plates 117 are deformed from their flat
state to their rolled-up state shown in FIG. 4, and the filter tow
material is conveyed through the tapered garniture 111 on the plug
wrap P. By the time the garniture belt 113 reaches the narrow end
111b of the garniture 111, the flat plates 117 form a closed circle
in cross-section, and the loose filter tow material is formed into
a compact rod 116 circumscribed by the plug wrap P.
[0045] As the filter tow material travels through the garniture
111, the ridges 118 in the plates 117 impress a grooved pattern on
the outer surface of the filter rod 116 so that when the filter rod
116 exits though the narrow exit opening 111b of the garniture 111,
it has a series of longitudinal grooves formed around the entire
perimeter of its outer surface. In order for the grooved pattern to
remain set in the filter rod, the garniture 111 includes a heating
means which accelerates the reaction of a plasticiser that is mixed
with the cellulose acetate fibres to set the fibres in the shape
formed by the plates 117 so that the shape remains in the resulting
filter rod 116 once it emerges from the narrow exit opening 111b of
the garniture 111. It will be appreciated that in the existing
filter rod forming apparatus, it is less crucial that the filter
shape is set so quickly--i.e. so that it sets when the filter rod
16 emerges from the garniture 11--since no pattern is formed in the
surface of the filter rod which may be lost if the filter material
is not set and is free to expand after exiting the garniture
11.
[0046] In the first embodiment of the invention shown in FIG. 2,
the heating means comprises inlet ducts 124 along the length of the
garniture 111 through which steam can be injected, as shown by
arrows CS'. In order that the heat of the steam can be most
efficiently applied to the cellulose acetate and plasticiser mix,
the garniture belt 113 is preferably porous to allow steam
therethrough. In the embodiment shown, the steam can pass through
the garniture belt 113 at the gaps where the individual plates 117
are joined. However, it is also intended within the scope of the
invention that further means may be provided to increase the
porosity of the garniture belt, such as perforations formed in the
plates 117 themselves.
[0047] The tapering of the garniture 111 from the wide open end
111a to the narrow exit end 111b also creates an inward pressure on
the filter tow material as it passes therethrough which squeezes it
and also helps the shaped pattern remain impressed on the resulting
filter rod 116. In order for the shape to more effectively be
retained in the filter rod 116, it may also be preferable for an
increased amount of plasticiser to be mixed with the cellulose
acetate fibres than would be used in existing rod manufacture.
Around 4-8% of plasticiser by weight to dry weight of cellulose
acetate tow may be used in existing processes, although in the
filter rod manufacturing process of the invention, preferably an
increased amount of plasticiser may be used, such as between 8-18%
by weight to dry weight of cellulose acetate tow, and preferably
between 12-18% by weight to dry weight of cellulose acetate
tow.
[0048] FIG. 5 shows an enlarged close up view of a garniture belt
213, similar to the view of FIG. 3, of an apparatus 210 of a second
embodiment of the present invention. The apparatus 210 differs from
the apparatus 110 of the first embodiment in the configuration of
the garniture belt 213, and all remaining features are the same as
described previously and retain the same reference numerals. The
garniture belt 213 comprises a plurality of linked plates 117
formed with a series of parallel ridges 118 and saw-toothed front
and rear edges 119, 120, and the plates 117 are hingedly connected
to each other end to end. However, unlike the apparatus 110 of the
first-described embodiment, the plates 117 are not connected by a
single flexible connecting element 121 but instead a plurality of
connecting pins 221 link adjacent plates 117, one connecting pin
221 on each angled face of the saw-tooth sections 119, 120
connecting to the adjacent angled face of the saw-tooth section
119, 120 of the adjacent plate 117. The connecting pins 221 can be
metal or plastic pins. Such connecting pins 221 may comprise ball
and socket joints to allow flexibility of movement between
individual pins. Alternatively, the pins 221 may include a pivot
connector along their length between each plate to provide the
garniture belt 213 with the required flexibility.
[0049] Operation of the apparatus of the second embodiment of the
invention is the same as that described above for the first
embodiment of the invention such that a formed filter rod 116 exits
though the narrow exit opening 111b of the garniture 111 with a
series of longitudinal grooves formed around the entire perimeter
of its outer surface. However, in this embodiment, as the garniture
belt 213 passes through the garniture 111 and the plates 117 are
deformed from their flat configuration to their rolled-up state,
the joins between the plates 117 are allowed to deform due to the
plurality of individual connecting pins 221 being discrete items
from one another, rather than the single connecting element 121
being a flexible component, as in the first embodiment of the
invention.
[0050] FIG. 6 shows an enlarged close up view of a garniture belt
313, similar to the view of FIGS. 3 and 5, of an apparatus 310 of a
third embodiment of the present invention. The apparatus 310
differs from the apparatuses 110, 210 of the first and second
embodiments in the configuration of the garniture belt 313, and all
remaining features are the same as described previously and retain
the same reference numerals. Instead of comprising a plurality of
linked plates as with the first and second embodiments of the
invention, the garniture belt 313 comprises a continuous flexible
belt 317a which has a flexible but resilient coating 317b formed on
one side thereof which has a series of parallel ridges 318
extending in a longitudinal direction of the garniture belt 313.
The coating 317b may be of a suitable resilient but preferably
heat-resistant material such as plastic and/or rubber, and can be
formed as a separate component and subsequently bonded to the
underlying flexible belt 317a, or may be moulded onto the flexible
belt 317a and set thereon with the desired surface relief pattern.
The coating 317b is sufficiently flexible to enable the garniture
belt 313 to deform into a rolled up state, similar to that shown in
FIG. 4. In addition to the above, as the garniture belt 313 of the
third embodiment of the invention is not made up of discrete plates
joined together, the apparatus 310 may include existing curved-face
rollers 14 instead of flat faceted rollers 114 of the first and
second embodiments of the invention.
[0051] Operation of the apparatus 310 of the third embodiment of
the invention is the same as that described above for the first
embodiment of the invention such that a formed filter rod 116 exits
though the narrow exit opening 111b of the garniture 111 with a
series of longitudinal grooves formed around the entire perimeter
of its outer surface. However, it is the ridges 318 in the
resilient coating 317b which form the grooves/patterns in the
filter rod as it passes through the garniture 111.
[0052] FIG. 7 shows an enlarged close up view of a garniture belt
413, similar to the view of FIGS. 3, 5 and 6, of an apparatus 410
of a fourth embodiment of the present invention. Depending on the
implementation, the apparatus 410 may be similar or identical to
that of the third embodiment of the invention except that instead
of the resilient coating 317b being provided along the entire
length of the flexible belt 317a, such a resilient coating 417b
with a surface relief pattern in the form of ridges 418 is provided
intermittently along the flexible belt 417a, such that a
grooved/shaped pattern is only imparted onto the resulting filter
rod intermittently or in any desired spacing.
[0053] As with the third embodiment of the invention, the coating
417b may be of a suitably resilient and preferably heat-resistant
material such as rubber and/or plastic, and may be formed as a
separate component and subsequently bonded to the underlying
flexible belt 417a, or may be moulded onto the flexible belt 417a
and set thereon with the desired surface relief pattern. Also, the
coating 417b is sufficiently flexible to enable the garniture belt
413 to deform into a rolled up state, similar to that shown in FIG.
4, and the apparatus 410 may include existing curved-face rollers
14 instead of flat faceted rollers 114 of the first and second
embodiments of the invention.
[0054] Operation of the apparatus 410 of the fourth embodiment of
the invention may be similar to or the same as that described above
for the third embodiment of the invention such that a formed filter
rod 116 exits though the narrow exit opening 111b of the garniture
111 with a series of longitudinal grooves formed around the entire
perimeter of its outer surface. However, in some implementations,
the grooved pattern is only imparted onto the resulting filter rod
intermittently.
[0055] In all of the garniture belts 213, 313, 413 of the second to
fourth embodiments of the invention, additional means may be
provided to increase the porosity of the garniture belts to improve
the heat transfer of the steam to the cellulose acetate/plasticiser
mix, such as perforations in the belt/plates.
[0056] A filter rod producing apparatus 510 of a fifth embodiment
of the invention is shown in FIGS. 8, 9A and 9B, which is similar
to the first embodiment shown in FIG. 2 and like features retain
the same reference numerals. However, the apparatus 510 of the
fifth embodiment of the invention has a differing configuration of
the garniture 511. More specifically, the garniture 511 comprises a
double-walled structure with a solid outer wall 511a and a
perforated inner wall 511b, defining a cavity 512 therebetween.
This is shown more clearly in FIGS. 9A and 9B which are
cross-sectional views along the lines X-X and Y-Y of FIG. 8
respectively. The garniture 511 includes inlet ducts 124 to allow
steam `S` to be fed into the cavity 512 between the walls 511a,
511b of the garniture 511. The steam is then able to fill the
cavity 512 and from there pass through the perforations 513 in the
inner wall 511b to the garniture belt 113 within the garniture 511.
As discussed above, the garniture belt 113 is preferably porous to
as to allow the heat of the steam to more effectively transfer to
the cellulose acetate and entrained plasticiser to effect the
accelerated reaction and setting of the filter rod 116.
[0057] It will be appreciated that an advantage of the apparatus
510 of the fifth embodiment of the invention is that by having a
double-walled garniture 511 and the cavity 512 therein, the steam
is able to more effectively surround the garniture belt 113 and the
filter rod 116 therein as it passes through the garniture 511,
which enables a quicker and more efficient heat transfer to the
filter rod material, improving the process of setting the shape
formed in the surface of the filter rod 116. It is intended within
the scope of the invention that the apparatus of the fifth
embodiment of the invention may include a perforated garniture belt
as described above, in order to further improve the heat transfer
of the steam to the filter tow material and entrained
plasticiser.
[0058] A filter rod producing apparatus 610 of a sixth embodiment
of the invention is shown in FIG. 10, which is similar to the first
embodiment shown in FIG. 2 and like features retain the same
reference numerals. However, the apparatus 610 of the sixth
embodiment of the invention includes a different configuration of
the garniture 611. More specifically, the garniture 611 comprises
heating elements 612 along its length. In this embodiment, no inlet
ducts are provided for the introduction of steam into the garniture
611. Instead, the heat required to activate and accelerate the
reaction of the plasticiser and the cellulose acetate of the filter
material is provided directly by conduction from the heating
element 612 through the wall of the garniture 611.
[0059] An advantage of the apparatus 610 of the sixth embodiment of
the invention is that there is no requirement for any steam source
to provide the heat for the plasticiser/cellulose acetate reaction.
It will also be appreciated that as heat is transferred to the
filter rod material by conduction, it is not necessary to provide a
perforated/porous garniture belt 113. However, for optimum
effectiveness of the apparatus 610 of the sixth embodiment of the
invention, the material of the garniture belt 113 should preferably
be a good conductor of heat, such as a metallic material, so that a
quicker and more efficient heat transfer to the filter rod material
can be achieved, improving the process of setting the shape formed
in the surface of the filter rod 116.
[0060] The heating element 612 may be provided on an outer surface
of the garniture 611, as shown in FIG. 10, or alternatively, may be
formed integrally within the walls of the garniture 611. The
heating element may preferably be an electric heating element.
[0061] A filter rod producing apparatus 710 of a seventh embodiment
of the invention is shown in FIGS. 11 and 12, and is similar to the
first embodiment shown in FIG. 2, with like features retaining the
same reference numerals. However, the apparatus 710 of the seventh
embodiment of the invention includes a different configuration of
the garniture 711. More specifically, the garniture 711 comprises a
pressure roller 712 in the interior of the garniture 711 at an
upper portion thereof. This is shown more clearly in FIG. 12 which
is a cross-sectional view along the line Z-Z of FIG. 11. The
pressure roller 712 is positioned and configured to guide the
lateral edges of the garniture belt 113 together as the garniture
belt 113 is deflected into the rolled up configuration to surround
the filter rod 116 being formed therein. The pressure roller 712
also serves to exert an inwards force on the garniture belt 113
where the two lateral edges meet, corresponding to the seam of the
filter rod, in order to ensure the relief pattern is fully
impressed on the filter rod 116 all the way around its
circumference and to avoid a less pronounced pattern being formed
at the point at which the lateral edges of the garniture belt 113
meet. It is intended within the scope of the invention that one or
more pressure rollers may be provided and may be fixed within the
garniture, or alternatively may be moveable and inwardly biased
relative to the garniture passage. Furthermore, the or each toilet
712 may be formed as part of the heater (or cooling) bar (not
shown) which may be present at an upper portion of the garniture
711, as described above.
[0062] A filter rod producing apparatus 810 of an eighth embodiment
of the invention is shown in FIGS. 13 and 14 and, similarly to
previously-described embodiments of the invention, is configured to
form filter rods from loose filter tow material which include a
grooved relief pattern formed on an outer surface thereof. The
apparatus 810 comprises a garniture 811 having a wide entrance 811a
and narrower exit 811b with a tapered `tow guide` portion 811c
therebetween, and a guide funnel 812 and transport jet, and a
continuous garniture belt 813 which extends through the garniture
811 and over a plurality of guide rollers 814 and is driven to be
conveyed around the rollers 114 in the direction shown by arrows
`V` in FIG. 13. As with the existing filter rod producing apparatus
10, plug wrap `P` may be fed from a spool 815 onto the upper
surface of the garniture belt 813 which conveys it through the
garniture 811 such that it deforms into a rolled up configuration
surrounding a compressed cellulose acetate filter rod, as described
previously.
[0063] The apparatus 810 of the eighth embodiment of the invention
differs from the previously-described embodiments at least in that
the garniture belt 813 is not provided with any surface relief
pattern to be impressed onto the filter rod as the garniture belt
813 and filter tow material are conveyed through the garniture 811.
Instead, the garniture belt 813 is a thin continuous flexible belt
of material. Furthermore, the inner wall of the garniture 811 is
provided with a plurality of ribs 817 projecting inwardly and
extending longitudinally towards the narrow exit opening 811b of
the garniture 811. This can be seen more clearly in FIG. 14 which
is a cross-sectional view of the garniture 811 taken along the line
W-W in FIG. 13.
[0064] In use, loose filter tow material (not shown), such as
cellulose acetate, is fed into the funnel 812 as shown by arrow `E`
and is guided into the garniture 811 by a transport jet of
compressed air from a jet nozzle (not shown). As the garniture belt
813 enters and is conveyed through the garniture 811, the filter
tow material is compressed by the inwardly tapering section and the
plug wrap P is folded around the outside of the compressed cylinder
of filter tow material, such that and when the filter tow material
it exits though the narrow exit opening 811b of the garniture 811,
the filter tow material is formed into a compressed cylindrical
filter rod 816 enveloped by an outer plug wrap P.
[0065] As the filter tow material travels through the garniture
811, the ribs 817 on inner surface of the garniture wall impress a
grooved pattern on the outer surface of the filter rod 816 so that
when the filter rod 816 exits though the narrow exit opening 811b
of the garniture 811, it has a series of longitudinal grooves
formed around its outer surface. The ribs are preferably provided
only in the narrow portion of the garniture 811 so that the grooves
are only formed on the filter rod 816 once the filter tow material
is substantially fully compressed and circumscribed with the plug
wrap P. It will be appreciated that in this embodiment of the
invention, the garniture belt 813 is sufficiently thin and flexible
that the grooved shape can be effectively imparted onto the filter
rod 816 by the ribs 817 though the thickness of the garniture belt
813.
[0066] In order for the grooved pattern to remain set in the filter
rod, the garniture 811 includes a heating means which accelerates
the reaction of a plasticiser that is mixed with the cellulose
acetate fibres to set the fibres in the desired shape. In the
embodiment shown in FIG. 13, the heating means comprises inlet
ducts 824 along the length of the garniture 811 through which steam
can be injected, as shown by arrows `S`, as described previously in
respect of the first embodiment of the invention. Accordingly, as
also described previously, in order that the heat of the steam can
be most efficiently applied to the cellulose acetate and
plasticiser mix, the garniture belt 813 may be porous to allow
steam therethrough, for example, the material of the garniture belt
813 itself may be porous, or the garniture belt 813 may include
means to increase the porosity of the garniture belt, such as
perforations. For example, the garniture belt may be formed from a
perforated metal which is resiliently deformable to pass over the
rollers 814 and roll up within the garniture 811 and deform to the
shape of the interior wall of the garniture 811. Such a metallic
perforated garniture belt would exhibit the advantages of being
porous to allow steam to pass therethrough, and also conductive to
allow heat to be efficiently transferred from the heating means to
the filter rod 816.
[0067] It is also intended within the scope of the invention that
double wall structure described above with reference to the fifth
embodiment of the invention, and the alternative heating means
described above with reference to the sixth embodiment of the
invention, could be applied to the alternative garniture 811 of the
apparatus 810 of the eighth embodiment of the invention.
[0068] In the first to seventh embodiments of the invention shown
and described above, the garniture belts 113, 213, 313, 413, 513,
613, 713 include longitudinal grooves formed thereon to impart a
corresponding shape to the outer surface of the resulting filter
rod. However, the invention is not intended to be limited to a
method and apparatus for forming grooved filter rods, and it is
intended within the scope of the invention that other shapes could
be formed on filter rods by correspondingly shaped relief patterns
being formed on the garniture belts, such as helical grooved,
circumferential grooves, discrete depressions or any other
combination/pattern of recesses/protrusions. Also, with regard to
embodiments of the invention which include a garniture belt of
connected plates, not every plate of the garniture belt necessarily
includes a shaped/grooved pattern thereon to impart a corresponding
shape to the filter rod. Instead, such a pattern could be provided
on every other plate only, or every third plate, or any other
variation, such that the grooved/shaped pattern is only imparted
onto the resulting filter rod intermittently or in any desired
spacing, as per the order of the shaped/non-shaped garniture belt
plates. In such an embodiment, those plates which do not include a
relief pattern thereon to impart a shape to the filter rod may not
necessarily be formed of the same material as the shaped plates.
For example, the sections of garniture belt between the shaped
plates may be of existing woven belt construction. Yet further, the
plates of the garniture belt shown and described above are of
metallic construction although they maybe of other suitable
material that is sufficiently rigid to impart the shaped pattern on
the filter rod within the garniture, but is also elastically
deformable to be able to roll up on itself to fit into the
garniture. Such materials could include plastic or rubber. However,
metal plates, such as copper or aluminium, or even gold, provide
the additional advantage of good heat conductivity to allow the
heat from the steam or other heat source to quickly pass to the
filter tow material and entrained plasticiser to effect the shaping
and setting of the filter rod. It is also intended within the scope
of the invention that the plates of the garniture belt may be
coated with a coating which may improve wear resistance and/or be a
non-stick coating such as PTFE, titanium or a carbonised coating.
The lateral edges of the garniture belts of the invention are
intended to at least meet in the fully rolled up configuration with
in the garniture, although they may also overlap in the most rolled
up configuration, within the scope of the invention.
[0069] It is intended that the various embodiments of the invention
described above may comprise a garniture belt formed of a single
band with the intended relief pattern to be imparted on the filter
rod, formed on the surface thereof, instead of the garniture belt
comprising a plurality or articulated plates. Such a band could be
made of sufficiently deformable material to enable it to pass over
rollers of the apparatus, and deflect into a rolled up
configuration within the garniture, but also be resilient enough
that the relief pattern thereon can be impressed into the surface
of the filter rod being formed. Such a garniture belt may
preferably be made of a conductive material such as metal,
preferably aluminium, to efficiently conduct heat from a heat means
to the filter rod being formed. Furthermore, the garniture belt may
include perforations to enable steam in embodiments of the
invention where steam is used as a heating source, of more
effectively be transferred to the filter rod being formed to
transfer heat thereto.
[0070] All embodiments of the invention shown and described above
include a plug wrap P being fed into the garniture and onto which
the loose filter tow material is directed, such that the resulting
filter rod 116 comprises filter material wrapped in the plug wrap.
However, it is intended within the scope of the invention that the
plug wrap may be omitted and instead, the filter tow material may
be fed directly onto the garniture belt which conveys the filter
material through the garniture, compresses it into a filter rod and
forms the desired relief pattern on the outer surface thereof. In
such an embodiment of the invention, the filter rod produced would
remain in the desired rod form with the surface pattern thereon
purely due to the compression exerted by the garniture belt within
the garniture and the activation of the plasticiser entrained in
the filter material. As a further alternative intended to fall
within the scope of the invention, a plug wrap-coated filter rod
may be produced but instead of the plug wrap P being introduced
together with the loose filter tow material into the garniture, the
filter rod with surface relief pattern may be formed in the
garniture without a plug wrap, as described above, and the plug
wrap may be subsequently wrapped around the formed filter rod once
it has exited the garniture. Such an embodiment is shown as an in
dashed lines in FIG. 2 as an alternative configuration of the first
embodiment of the invention, in which a plug wrap P' is fed from a
spool 115' and is wrapped around the filter rod 116 after it is has
been formed in, and exited from, the garniture 111. The plug wrap
P' may be wrapped around the filter rod such that the plug wrap P'
conforms to the relief pattern formed on the surface of the filter
rod 116, so that the finished filter rod with outer plug wrap P'
exhibits the desired surface relief pattern on its outer surface.
Although shown in FIG. 2 as an alternative configuration of the
apparatus of the first embodiment of the invention, it is intended
that this alternative arrangement of plug wrap application could be
used in any of the other embodiments of the invention described
above.
[0071] In the embodiments of the invention shown and described
above which include a garniture belt made of a plurality of
articulated plates, the rollers around which the garniture belt
passes is described as being faceted to correspond to the
individual plates of the garniture belt. However, the invention is
not limited to such roller configuration and instead, other rollers
may be used, for example rollers with a deformable outer surface,
such as rubber or plastic/polymer, to provide a softer surface
against which the garniture belt may lie and which may deform to
hold the shape of the garniture belt/plates. Alternatively, the
rollers may include a plurality of recesses corresponding to the
individual plates of the garniture belt, and which receive each
garniture belt plate as the garniture belt passes over the roller.
Yet further, the rollers may be of an increased diameter so that
the garniture belt plates are less deformed on the large curved
roller surface.
[0072] Embodiments of the invention shown and described above are
examples only and the invention is not intended to be limited to
these specific examples. Furthermore, it is intended that the
present invention may include any combination of non-mutually
exclusive features described above, and is as defined by the scope
of the claims hereafter.
* * * * *