BACKGROUND OF THE INVENTION
Field of the Invention
[0001] Embodiments of the present invention relate to the formation of tobacco products,
such as smoking articles (e.g., cigarettes), and more particularly, to apparatuses
and associated methods for inserting an adsorbent material into a cigarette filter.
Description of Related Art
[0002] Popular smoking articles, such as cigarettes, have a substantially cylindrical rod
shaped structure and include a charge, roll or column of smokable material, such as
shredded tobacco (e.g., in cut filler form), surrounded by a paper wrapper, thereby
forming a so-called "smokable rod" or "tobacco rod." Normally, a cigarette has a cylindrical
filter element aligned in an end-to-end relationship with the tobacco rod. Typically,
a filter element comprises plasticized cellulose acetate tow circumscribed by a paper
material known as "plug wrap." Certain filter elements can incorporate polyhydric
alcohols. Typically, the filter element is attached to one end of the tobacco rod
using a circumscribing wrapping material known as "tipping paper." Descriptions of
cigarettes and the various components thereof are set forth in
Tobacco Production, Chemistry and Technology, Davis et al. (Eds.) (1999). A cigarette is employed by a smoker by lighting one end thereof and burning the
tobacco rod. The smoker then receives mainstream smoke into his/her mouth by drawing
on the opposite end (e.g., the filter end) of the cigarette.
[0003] Certain cigarettes incorporate filter elements having adsorbent materials dispersed
therein, such as activated carbon or charcoal materials (collectively, carbonaceous
materials) in particulate or granular form (i.e., powder). For example, an exemplary
cigarette filter can possess multiple segments, and at least one of those segments
can comprise particles of high carbon-content materials. Various types of filters
incorporating charcoal particles or activated carbon types of materials are set forth
in
U.S. Pat. Nos. 2,881,770 to Touey;
3,101,723 to Seligman et al.;
3,236,244 to Irby et al.;
3,311,519 to Touey et al.;
3,347,247 to Lloyd;
3,349,780 to Sublett et al.;
3,370,595 to Davis et al.;
3,413,982 to Sublett et al. ;
3,602,231 to Dock;
3,972,335 to Tigglebeck et al.;
5,360,023 to Blakley et al.; and
6,537,186 to Veluz;
U.S. Pat. Publication No. 2007/0056600 to Coleman, III et al. ;
PCT WO 2006/064371 to Banerjea et al. and
PCT WO 2006/051422 to Jupe et al..
[0004] As mentioned, such carbonaceous material types are typically in the form of particles
or granules when incorporated into the filter elements. For example, granules of carbonaceous
material can be incorporated into "dalmation" types of filter regions using the general
types of techniques used for traditional dalmation filter manufacture. Techniques
for production of dalmation filters are known, and representative dalmation filters
have been provided commercially by Filtrona Greensboro Inc. Alternatively, granules
of carbonaceous material can be incorporated into "cavity" types of filter regions
using the general types of techniques used for traditional "cavity" filter manufacture.
Alternatively, other known types of techniques and equipment for producing filter
segments incorporating granular materials can be suitably altered so as to introduce
carbonaceous material into the filter segments. However, such techniques often are
rudimentary in that the particulates or granules of carbonaceous material are roughly
inserted into the filter element as either a loose powder or a slurry, a process which
can be described as, for example, inconsistent, wasteful, and "messy."
[0005] As such, there exists a need for apparatuses and methods for inserting the adsorbent
material into the filter segments/elements of a smoking article in a manner facilitating
a cleaner and more efficient process. Such apparatuses and methods should desirably
be able to insert the adsorbent material in various forms into the filter element.
SUMMARY OF THE INVENTION
[0006] The above and other needs are met by embodiments of the present invention which,
according to various aspects, provide apparatuses, as defined by claims 1 to 5, and
methods, as defined by claims 6 to 13, for inserting an adsorbent material carried
by a carrier material into a filter rod member of a smoking article. Accordingly,
one aspect relates to an apparatus for forming filter rods used in the manufacture
of smoking articles, wherein each rod has an adsorbent material, carried by a carrier
material, inserted into the filter rod along its length such that, when the rod is
longitudinally subdivided into rod portions, each rod portion includes at least a
portion of the adsorbent material. The apparatus incorporates equipment for supplying
a continuous supply of filter material (e.g., a filter tow processing unit adapted
to supply filter tow to a continuous rod forming unit). A representative apparatus
may also include, for example, a hopper and rotating wheel arrangement such as disclosed
in U.S. Patent Application Publication No.
US 2007/0068540 A1 to Thomas et al., operably engaged with the filter supply equipment, for supplying the carrier material
carrying the adsorbent material to the filter material. Other arrangements for inserting
objects into the filter material are disclosed, for example, in
U.S. Patent No. 4,862,905 to
Green, Jr. et al. (i.e., insertion of individual strand portions); U.S. Patent Application Publication
No.
US 2007/0068540 A1 to Thomas et al. (i.e., insertion of capsules);
U.S. Patent Application No. 11/461,941 to Nelson et al. (i.e., insertion of continuous strands);
U.S. Patent Application No. 11/760,983 to Stokes et al. (i.e., insertion of continuous strands); and
U.S. Patent No. 7,074,170 to Lanier, Jr. et al..
[0007] The continuous supply of filter material is formed, for example, by a rod-forming
unit into a continuous cylindrical rod member. The carrier material carrying the adsorbent
material is inserted by an insertion unit into the rod member. In some aspects, the
continuous rod may then be subdivided at predetermined intervals by a rod-dividing
unit so as to form a plurality of filter rods or rod portions or filter elements such
that each rod portion includes at least a portion of the adsorbent material.
[0008] In some aspects, a method of forming a cigarette filter rod member comprises forming
a continuous supply of a filter material into a continuous cylindrical rod member,
and inserting an adsorbent material carried by a carrier material into the rod member
such that the adsorbent material is disposed within the rod member. Such a method
may further comprise dividing the rod member into a plurality of rod portions along
the longitudinal axis thereof such that each rod portion includes at least a portion
of the adsorbent material.
[0009] A cigarette filter can comprise at least one filter segment having one or more composite
fiber structures imbedded therein, the composite fiberstructure comprising a carrier
fiber and an adsorbent fiber (e.g., a carbonaceous fiber), the adsorbent fiber comprising
an adsorbent material. Exemplary carbonaceous fibers can be prepared by carbonization
of a precursor fiber, such as phenolic fibers, cellulosic fibers, rayon fibers, acrylic
fibers, and pitch fibers. In certain embodiments, the filter comprises one or more
segments of fibrous tow material, such as cellulose acetate tow.
[0010] The composite fiber structure can comprise multiple carrier fibers or multiple adsorbent
fibers. One or both of the carrier fiber and adsorbent fiber can be in the form of
a yarn. The entire composite fiber structure can also be in the form of a yarn. The
carrier fiber acts as a carrier for the adsorbent fiber, such as by enwrapping the
adsorbent fiber around the carrier fiber.
[0011] In another aspect, a cigarette filter can comprise at least one filter segment having
at least one degradable fiber imbedded therein, such as a biodegradable fiber. The
fiber can be any strand, thread, or yam that has any of a variety of cross-sections,
including a circular or a flattened cross-section. The fiber can provide a visual
difference or a textural/tactile difference to the filter element The fiber itself
could alter the character or nature of the smoke passing through the filter, or optionally
carry an additive capable of altering the character or nature of the smoke (e.g.,
such as one or more adsorbent materials, flavorants, deodorizing agents, or combinations
thereof). The additive can be carried by, or associated with, the degradable fiber
using a variety of techniques, such as by absorption of the additive into the fiber
structure, coating of the additive onto the fiber structure, adherence of a solid
additive onto the surface of the fiber, or wrapping of an additive in the form of
a fiber (e.g., a carbonaceous fiber) around the degradable fiber.
[0012] Exemplary biodegradable fibers include cellulosic fibers, polyvinyl alcohol, aliphatic
polyesters, aliphatic polyurethanes, cis-polyisoprene, cis-polybutadiene, polyhydroxy
alkanoates, polyanhydrides, and copolymers and blends thereof. In one embodiment,
the biodegradable fiber is a bamboo fiber or a polylactic acid fiber.
[0013] Smoking articles can incorporate a filter element as described herein, such as a
smoking article comprising a rod of smokable material circumscribed by a wrapping
material, the rod of smokable material being attached to a cigarette filter.
[0014] Embodiments of the present invention thus provide significant advantages as disclosed
herein in further detail.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to assist the understanding of embodiments of the invention, reference will
now be made to the appended drawings, which are not necessarily drawn to scale. The
drawings are exemplary only, and should not be construed as limiting the invention.
FIG. 1 is an exploded perspective view of a smoking article having the form of a cigarette,
showing the smokable material, the wrapping material components, and the filter element
of the cigarette;
FIG. 2 is a cross-sectional view of a filter element incorporating an adsorbent material
therein according to one embodiment of the present invention;
FIGS. 3A-3D are cross-sectional views of a smoking article having the form of a cigarette, showing
the smokable material, the wrapping material components, and the adsorbent material-containing
filter element of that cigarette;
FIG. 4 is a schematic of a rod-making apparatus including a portion of the filter tow processing
unit, a source of an adsorbent material carried by a carrier material, an insertion
unit, and a filter rod-forming unit, in accordance with one embodiment of the present
invention;
FIG. 5 is a cross-sectional view of a filter element incorporating a carbonaceous fiber
carried by a carrier fiber; and
FIG. 6 is a perspective view of a carbonaceous fiber carried by a carrier fiber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The present inventions now will be described more fully hereinafter with reference
to the accompanying drawing. The invention may be embodied in many different forms
and should not be construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will satisfy applicable legal
requirements. Like numbers refer to like elements throughout. As used in this specification
and the claims, the singular forms "a," "an," and "the" include plural referents unless
the context clearly dictates otherwise.
[0017] Referring to FIG.
1, there is shown a smoking article
10 in the form of a cigarette and possessing certain representative components of a
smoking article produced or formed by the present invention. The cigarette
10 includes a generally cylindrical rod
12 of a charge or roll of smokable filler material contained in a circumscribing wrapping
material
16. The rod
12 is conventionally referred to as a "tobacco rod." The ends of the tobacco rod
12 are open to expose the smokable filler material. The cigarette
10 is shown as having one optional band
22 (e.g., a printed coating including a film-forming agent, such as starch, ethylcellulose,
or sodium alginate) applied to the wrapping material
16, and that band circumscribes the cigarette rod in a direction transverse to the longitudinal
axis of the cigarette. That is, the band
22 provides a cross-directional region relative to the longitudinal axis of the cigarette.
The band
22 can be printed on the inner surface of the wrapping material (i.e., facing the smokable
filler material), or less preferably, on the outer surface of the wrapping material.
Although the cigarette can possess a wrapping material having one optional band, the
cigarette also can possess wrapping material having further optional spaced bands
numbering two, three, or more.
[0018] At one end of the tobacco rod
12 is the lighting end
18, and at the mouth end 20 is positioned a filter element
26. The filter element
26 positioned adjacent one end of the tobacco rod
12 such that the filter element and tobacco rod are axially aligned in an end-to-end
relationship, preferably abutting one another. Filter element
26 may have a generally cylindrical shape, and the diameter thereof may be essentially
equal to the diameter of the tobacco rod. The ends of the filter element
26 permit the passage of air and smoke therethrough.
[0019] In some instances, the filter element
26 may be configured as shown in FIG.
2, wherein the filter includes a first filter segment
32 positioned adjacent one end of the tobacco rod
12. The first filter segment
32 includes filter material
40 (e.g., cellulose acetate tow impregnated with plasticizer, such as triacetin). In
other instances, the filter element
26 may not be divided into segments, such as shown in FIG.
3. With continuing reference to FIG. 2, within the filter material
40 of the first segment may be inserted an adsorbent material/particulate
50. Previously, such adsorbent material
50 had been roughly inserted into the filter material
40. That is, the adsorbent material
50 had been inserted while in a loose particulate form, such as a powder or slurry.
Further, within the filter material
40 of the first segment may also be optionally dispersed a plurality of particles
52 or otherwise breakable or rupturable capsules comprising a flavoring agent. In certain
embodiments where a carbonaceous material is used as the adsorbent material
50, at least a portion of the carbonaceous material, and typically virtually all of
the carbonaceous material, is in intimate contact with an effective amount of a mixture
of polyol ester (e.g., triacetin) and polyol (e.g., propylene glycol). If desired,
the filter element also can be incorporate other components that have the ability
to alter the properties of the mainstream smoke that passes throughout the filter
element. See, for example,
U.S. Pat. Application Publication Nos. 2004/0237984 to Figlar et al.;
2005/0268925 to Schluter et al.;
2006/0130861 to Luan et al.; and
2006/0174899 to Luan et al..
[0020] The filter element
26 may also possess a second filter segment
36 longitudinally disposed relative to the first segment
32 and positioned at the extreme mouth end of the cigarette 10. The second filter segment
36 includes filter material
48 (e.g., cellulose acetate tow impregnated with plasticizer, such as triacetin) that
is overwrapped along the longitudinally extending surface thereof with circumscribing
plug wrap material
28. The second filter segment
36 may be substantially free of adsorbent and breakable or rupturable capsules, meaning
that such additives are not visible when viewing the extreme mouth end of the filter
element
26.
[0021] The filter element
26 is circumscribed along its outer circumference or longitudinal periphery by a layer
of outer plug wrap
28. The outer plug wrap
28 overlies each of the first filter segment
32 and the second filter segment
36, so as to provide a combined, two-segment filter element.
[0022] The filter element
26 is attached to the tobacco rod
12 using tipping material
46 (e.g., essentially air impermeable tipping paper), that circumscribes both the entire
length of the filter element
26 and an adjacent region of the tobacco rod
12. The inner surface of the tipping material
46 is fixedly secured to the outer surface of the plug wrap
28 and the outer surface of the wrapping material
16 of the tobacco rod, using a suitable adhesive; and hence, the filter element and
the tobacco rod are connected to one another. See also the tipping materials and configurations
set forth in
U.S. Pat. Publication No. 2008/0029111 to Dube et al..
[0023] A ventilated or air diluted smoking article can be provided with an optional air
dilution mechanisms, such as a series of perforations
30, each of which extend through the tipping material and plug wrap. The optional perforations
30, shown in FIG.
1, can be made by various techniques known to those of ordinary skill In the art, such
as laser perforation techniques. Alternatively, so-called off-line air dilution techniques
can be used (e.g., through the use of porous paper plug wrap and pre-perforated tipping
paper). For cigarettes that are air diluted or ventilated, the amount or degree of
air dilution or ventilation can vary. Frequently, the amount of air dilution for an
air diluted cigarette is greater than about 10 percent, generally is greater than
about 20 percent, often is greater than about 30 percent, and sometimes is greater
than about 40 percent. Typically, the upper level for air dilution for an air diluted
cigarette is less than about 80 percent, and often is less than about 70 percent.
As used herein, the term "air dilution" is the ratio (expressed as a percentage) of
the volume of air drawn through the air dilution means to the total volume and air
and smoke drawn through the cigarette and exiting the extreme mouth end portion of
the cigarette.
[0024] During use, the smoker lights the lighting end
18 of the cigarette 10 using a match or cigarette lighter. As such, the smokable material
12 begins to burn. The mouth end
20 of the cigarette
10 is placed in the lips of the smoker. Thermal decomposition products (e.g., components
of tobacco smoke) generated by the burning smokable material
12 are drawn through the cigarette
10, through the filter element
26, and into the mouth of the smoker. During draw, certain amount of certain gaseouscomponentsofthe
mainstream smoke are removed from the mainstream smoke or neutralized by the adsorbent
material
50 within the filter element
26. Filters incorporating such adsorbent material
50, such as carbonaceous filter components (e.g., activated charcoal particles), have
the capability of capturing a wide range of mainstream tobacco smoke vapor phase components.
If desired, prior to, during or after the smoking experience, the smoker can optionally
squeeze the filter element. As a result, at least a portion of the optional breakable
capsules that remain unbroken can be broken, and hence release the particles
52 of flavoring agent contained therein.
[0025] Other filter element arrangements may be produced or formed without departing from
embodiments of the present invention. For example, the filter element
26 could include more than the two segments set forth in FIG.
2. Although less preferred, the filter element
26 could also include a cavity formed between two filter material segments, with the
adsorbent material
50 and the optional flavoring agent 52 mixed together therein. Although it is preferable
to avoid positioning the filter segment comprising the adsorbent material
50 and optional flavor agent
52 at the extreme mouth end of the filter, it is not necessary for the filter segment
comprising these additives to be located at the tobacco end of the filter. Instead,
the filter segment comprising the dispersed additives can be more centrally located
within the filter element
26 with one or more filter segments toward each end that do not contain the additives.
[0026] The dimensions of a representative cigarette
10 can vary. Preferred cigarettes are rod shaped, and can have diameters of about 7.5
mm (e.g., circumferences of about 20 mm to about 27 mm, often about 22.5 mm to about
25 mm); and can have total lengths of about 70 mm to about 120 mm, often about 80
mm to about 100 mm. The length of the filter element 30 can vary. Typical filter elements
can have total lengths of about 15 mm to about 40 mm, often about 20 mm to about 35
mm. For a typical dual-segment filter element, the downstream or mouth end filter
segment often has a length of about 10 mm to about 20 mm; and the upstream or tobacco
rod end filter segment often has a length of about 10 mm to about 20 mm.
[0027] If desired, suitable catalytic compounds, e.g., for the conversion of carbon monoxide
to carbon dioxide, can be incorporated into one or more segments of the filter element
26. Exemplary catalysts include noble metals (e.g., silver, gold, platinum), metal oxides,
ceramics, and mixtures thereof.
[0028] As illustrated in FIG.
2, one filter element
26 that may be formed in accordance with the present invention comprises multiple, longitudinally-extending
segments. Each segment can have varying properties and may include various materials
capable of filtration or adsorption of particulate matter and/or vapor phase compounds
from the mainstream smoke. Typically, the filter element of various aspects of the
invention includes 2 to 6 segments, frequently 2 to 4 segments. In some instances,
the filter element 26 may include a mouth end segment and a tobacco end segment, with
the tobacco end segment comprising the dispersed adsorbent material
50 and flavoring agent
52.
[0029] As shown in FIG.
2, the filter element may incorporate adsorbent material/particulate
50. Such adsorbent material
50 may be a material with relatively high surface area capable of adsorbing smoke constituents
without a high degree of specificity, or a material that adsorbs certain compounds
with a greater degree of specificity, such as an ion exchange resin. Exemplary types
of adsorbent material may include activated carbon, a molecular sieve (e.g., zeolites
and carbon molecular sieves), clay, an ion exchange resin, activated alumina, silica
gel, meerschaum, and combinations thereof. Any adsorbent material, or mixture of materials,
that has the ability to alter the character or nature of mainstream smoke passing
through the filter element may be used.
[0030] Exemplary ion exchange resins comprise a polymer backbone, such as styrenedivinylbenzene
(DVB) copolymers, acrylates, methacrylates, phenol formaldehyde condensates, and epichlorohydrin
amine condensates, and a plurality of eledrically charged functional groups attached
to the polymer backbone, and can be a weak base anion exchange resin or a strong base
anion exchange resin. Commercially available embodiments of such resins include DIAION®
ion-exchange resins available from Mitsubishi Chemical Corp. (e.g., WA30 and DCA11),
DUOLITE® ion exchange resins available from Rohm and Haas (e.g., DUOLTTE® A7), and
XOR-BEX resins available from Dalian Trico Chemical Co. of China.
[0031] A preferred adsorbent is a carbonaceous material, which is a material that is composed
primarily of carbon, and preferred carbonaceous materials are composed of virtually
all carbon. Typically carbonaceous materials comprise carbon in amounts of more than
about 85 percent, generally more than about 90 percent, often more than about 95 percent,
and frequently more than about 98 percent, by weight. The carbonaceous material can
have the form of charcoal, but most preferably is an activated carbon material. Activated
carbon materials are high surface area materials. Exemplary activated carbon materials
have surface areas of more than about 200 m
2/g, often more than about 1000 m
2/g, and frequently more than about 1500 m
2/g, as determined using the Brunaver, Emmet and Teller (BET) method described in
J. Amer. Chem. Soc., Vol. 60(2), pp. 309-319 (1938). Suitable examples of such carbonaceous materials are disclosed, for example, in
WO 2007/104908 to White et al.;
WO 2007/093757 to Awty et al.;
WO 2007/010249 to Fiebelkorn;
WO 2007/028957 to Lee;
WO 2006/136950 to Nunziata et al.;
WO 2006/103404 to Cashmore et al. ;
WO 2005/118133 to Branton et al.;
WO 2005/112670 to Bhattacharyya et al.;
WO 2005/082180 to Sampson et al.;
WO 2005/023026 to Branton et al.;
WO 2004/095957 to Bray et al.;
WO 2004/014161 to Grzonka;
WO 2003/092416 to Dittrich et al.;
WO 2003/034847 to Abhulimen et al.;
WO 2003/051144 to Schlüter et al.;
WO 2003/034848 to Abhulimen et al.;
WO 2001/041590 to Bushby et al.; and
US Pat. No. 7,370,657 to Zhuang et al.
[0032] The filter element
26 may incorporate an effective amountof adsorbent material
50, such as an effective amount of activated carbon. The effective amount is an amount
that, when incorporated into the filter element
26, provides some desired degree of alteration of the mainstream smoke of a cigarette
incorporating that filter element
26. For example, a cigarette filter element incorporating activated carbon particles
or granules can act to lower the yield of certain gas phase components of the mainstream
smoke passing through that filter element Typically, the amount of carbonaceous material
or other adsorbent within the filter element is at least about 20 mg, often at least
about 30 mg, and frequently at least about 40 mg, on a dryweight basis. Typically,
the amount of carbonaceous material or other adsorbent material 50 within the filter
element does not exceed about 500 mg, generally does not exceed about 400 mg, often
does not exceed about 300 mg, and frequently does not exceed about 200 mg, on a dry
weight basis.
[0033] The carbonaceous materials can be derived from synthetic or natural sources. Materials
such as rayon or nylon can be carbonized, followed by treatment with oxygen to provide
activated carbonaceous materials. Materials such as wood and coconut shells can be
carbonized, followed by treatment with oxygen to provide activated carbonaceous materials.
The level of activity of the carbon may vary. Typically, the carbon has an activity
of about 60 to about 150 Carbon Tetrachloride Activity (i.e., weight percent pickup
of carbon tetrachloride). Preferred carbonaceous materials are provided by carbonizing
or pyrolyzing bituminous coal, tobacco material, softwood pulp, hardwood pulp, coconut
shells, almond shells, grape seeds, walnut shells, macadamia shells, kapok fibers,
cotton fibers, cotton linters, and the like. Examples of suitable carbonaceous materials
are activated coconut hull based carbons available from Calgon Corp. as PCB and GRC-11
or from PICA as G277, coalbased carbons available from Calgon Corp. as S-Sorb, Sorbite,
BPL, CRC-11F, FCA and SGL, wood-based carbons available from Westvaco as WV-B, SA-20
and BSA-20, carbonaceous materials available from Calgon Corp. as HMC, ASC/GR- 1 and
SC II, Witco Carbon No. 637, AMBERSORB 572 or AMBERSORB 563 resins available from
Rohm and Haas, and various activated carbon materials available from Prominent Systems,
Inc. Other carbonaceous materials are described in U.S. Pat. Nos.
4,771,795 to White, et al. and
5,027,837 to Clearman, et al.; and European Patent Application Nos.
236,922;
419,733 and
419,981.
[0034] Preferred carbonaceous materials are coconut shell types of activated carbons available
from sources such as Calgon Carbon Corporation, Gowrishankar Chemicals, Carbon Activated
Corp. and General Carbon Corp. See, also, for example,
Activated Carbon Compendium, Marsh (Ed.) (2001), which is incorporated herein by reference.
[0035] Certain carbonaceous materials can be impregnated with substances, such as transition
metals (e.g., silver, gold, copper, platinum, and palladium), nanoparticles, potassium
bicarbonate, tobacco extracts, polyethyleneimine, manganese dioxide, eugenol, and
4-ketononanoic acid. The carbon composition may also include one or more fillers,
such as semolina. Grape seed extracts may also be incorporated into the filter element
20 as a free radical scavenger. Sintered or foamed carbon materials (see, e.g.,
US Pat. No. 7,049,382 to Haftka et al.) or gathered webs (see, e.g., US Pat. Appl. Pub. Nos.
US 2008/0092912 to Robinson et al. and
US 2007/0056600 to Coleman, III et al.) may be other options for incorporating an adsorbent material
50 into a filter element
20.
[0036] Various types of charcoals and activated carbon materials suitable for incorporation
into cigarette filters, various other filter element component materials, various
types of cigarette filter element configurations and formats, and various manners
and methods for incorporating carbonaceous materials into cigarette filter elements,
are set forth in
U.S. Pat Nos. 3,217,715 to Berger et al.;
3,648,711 to Berger et al.;
3,957,563 to Sexstone;
4,174,720 to Hall;
4,201,234 to Neukomm;
4,223,597 to Lebert;
5,137,034 to Perfetti et al.;
5,360,023 to Blakley et al.;
5,568,819 to Gentry et al.;
5,622,190 to Arterbery et al.;
6,537,186 to Veluz;
6,584,979 to Xue et al.;
6,761,174 to Jupe et al.;
6,789,547 to Paine III; and
6,789,548 to Bereman;
US Pat. Appl. Pub. Nos. 2002/0166563 to Jupe et al.;
2002/0020420 to Xue et al.;
2003/0200973 to Xue et al. ;
2003/0154993 to Paine et al.;
2003/0168070 to Xue et al.;
2004/0194792 to Zhuang et al.;
2004/0226569 to Yang et al.;
2004/0237984 to Figlar et al.;
2005/0133051 to Luan etal.;
2005/0049128 to Buhl et al.;
2005/0066984 to Crooks et al.;
2006/0144410 to Luan et al.;
2006/0180164 to Paine, III et al.; and
2007/0056600 to Coleman, III etal.; European Pat. Appl.
579410 to White; and
PCT WO 2006/064371 to Banerjea et al.. Representative types of cigarettes possessing filter elements incorporating carbonaceous
materials have been available as "Benson & Hedges Multifilter" by Philip Morris Inc.,
in the State of Florida during 2005 as a Philip Morris Inc. test market brand known
as "Marlboro Ultra Smooth," and as "Mild Seven" by Japan Tobacco Inc.
[0037] In light of the aforementioned issues associated with insertion of loose particulates
or granules of carbonaceous material into the filter element as either a loose powder
or a slurry, which may be inconsistent, wasteful, inefficient, and/or "messy," one
aspect of the present disclosure, as shown, for example, in FIGS.
3A-3D, involves engaging the adsorbent material
50 with a carrier material
55 prior to insertion of the resulting assembly into the filter element
26 (or a continuous filter rod before longitudinal severance thereof to form multiple
filter elements
26). Selection of a suitable carrier material
55 may facilitate, for example, improved production by more effectively and efficiently
inserting the now "captive" adsorbent material
50 into the filter element
26. That is, the adsorbent material
50 is carried by the carrier material
55 upon insertion thereof into the filter element
26. In some embodiments, the carrier material
55 may be in the form of, for example, a pellet (FIG.
3A), a capsule (FIG.
3B), a tube (FIG.
3C), a continuous elongate structure, a continuous strip, a strand or the like capable
of receiving and "holding captive" the adsorbent material
50 (FIG.
3D) so as to facilitate insertion thereof into the filter element
26 in a cleaner, more effective manner In some embodiments, individual or multiple forms
of the carrier material
55 may be inserted into the filter element
26. For example, individual or multiple capsules, tubes, pellets, etc. or combinations
thereof may be inserted into the filter element
26 in accordance with various aspects.
[0038] In some instances, the carrier material
55 may comprise a matrix material, such as, for example, a polymer material, which may
be impregnated with the adsorbent material
50 (i.e., the adsorbent material
50 may be suspended in or otherwise held by the matrix material) such that the adsorbent
material
50 may be carried with and by the matrix material into the filter element
26. For example, in some embodiments, the matrix material may comprise a high-density
or low-density polymer material, such as, for example, polyethylene or polypropylene,
impregnated with the adsorbent material
50 or otherwise having the adsorbent material
50, such as, for example, a carbonaceous material (e.g., activated carbon, charcoal)
dispersed therein. Preferably, the adsorbent material
50 is relatively evenly dispersed, but such even dispersion may not be absolutely necessary.
In embodiments where the carrier material
55 is formed as a tubular or capsular member, the adsorbent material
50 may be inserted into the tubular or capsular member so as to be contained thereby
upon insertion into the filter element
26. In embodiments where the carrier material 55 is formed as a continuous elongate
structure, the adsorbent material
50 may engage, contact, or otherwise interact with the continuous elongate structure
such that the adsorbent material
50 can be carried into the filter element
26 thereby. In embodiments where the carrier material
55 is formed as a continuous strip, the continuous strip may be lengthwise wrapped around
the adsorbent material
50 so as to contain the adsorbent material
50 therein (i.e., similar to a "tube") for insertion into the filter element
26.
[0039] Accordingly, the carrier material
55 may have a form that can be generally characterized as a containment or capturing
vehicle for the adsorbent material
50 that hold the same in a relatively secure manner such that the adsorbent material
50 can be delivered into the filter element/rod
26 via the carrier material
55 in a captive manner, as compared to the ioose powdered, granuiar, or particulate
form of the adsorbent material
50 inserted within filter element
26 of smoking articles in some prior art processes. As such, the insertion or incorporation
of the carrier material
55 carrying the adsorbent material
50 into the filter element
26 may be accomplished in a "cleaner" and more consistent and efficient manner (i.e.,
since the adsorbent material
50 is held "captive"), as compared to directing a loose powdered adsorbent material
50, or slurry form thereof, into the filter elements
26 (i.e., less dust, spillage, overflow, contamination, cross-contamination, etc.).
Such benefits may, in turn, translate into, for instance, less maintenance, a faster
process, higher efficiency and/or more consistent delivery of the adsorbent material
50, and increased safety. Further, the carrier material
55 may be readily configured in any manner suitable for facilitating insertion thereof
into individual filter elements
26. Other advantages may include a consistent measured size and/or amount of an adsorbent
material introduced into, partially disposed in, deposited in, intimately placed with,
centrally located in, disposed within, extending substantially all the way through,
or otherwise engaged with the filter material of the filter element of the smoking
article. In some instances, a matrix material such as a gel-type substance or otherwise
suitable substance may contain, though not necessarily through impregnation, the adsorbent
material
50 in a form capable of being incorporated within an individual filter element
26. In other instances, the carrier material
55 carrying the adsorbent material
50 may comprise a strand, strip, or otherwise elongate structure that is severed to
form individual portions capable of being inserted into the filter rod and/or filter
element
26.
[0040] In some instances, the carrier material
55 may be in the form of a pellet. In such instances, the pellets may be produced using
devices such as the FL-M Series granulator equipment (e.g., FL-M-3) from Vector Corporation
and as WP 120V and WP 200VN from Alexanderwerk, Inc. Exemplary compaction devices,
such as compaction presses, are available as Colton 2216 and Colton 2247 from Vector
Corporation and as 1200i, 2200i, 3200, 2090, 3090 and 4090 from Fette Compacting.
Devices for providing outer coating layers to compacted pelletized formulations are
available as CompuLab 24, CompuLab 36, Accela-Cota 48 and Accela-Cota 60 from Thomas
Engineering.
[0041] The pellets may be manufactured using a wide variety of extrusion techniques. For
example, such pellets may be manufactured using co-extrusion techniques (e.g., using
a twin screw extruder). In such a situation, successive wet or dry components or component
mixtures can be placed within separate extrusion hoppers. Steam, gases (e.g., ammonia,
air, carbon dioxide, and the like), and humectants (e.g., glycerin or propylene glycol)
can be injected into the extruder barrel as each dry mix is propelled, plasticized,
and cooked. As such, the various components are processed so as to be very well mixed,
and hence, come in complete contact with each other. For example, the contact of components
is such that individual components (e.g., adsorbent material or flavoring agents)
may be well embedded in the extrusion matrix or extrudate. See, for example,
US Pat. No. 4,821,749 to Toft et al..
[0042] The carrier material
55 carrying the adsorbent material
50 may be incorporated within a segment of a cavity filter (e.g., as pellets within
the central cavity region of a three-segment or stage filter element). Alternatively,
the carrier material
55 carrying the adsorbent material
50 may be dispersed within a fibrous filter material (e.g., as pellets dispersed throughout
a filter tow or gathered non-woven web material) as a segment of longitudinally multi-segmented
filter element (e.g., a two-segment filter element).
[0043] According to another aspect of the present invention, after insertion of the carrier
material
55 / adsorbent material
50 assembly into the filter element
26 (or the continuous filter rod), the adsorbent material
50 may be released from the carrier material
55 and into the filter material. For example, carrier material 55 may be dissolved,
disintegrated, degraded, or otherwise destroyed
in situ so as to release and/or disperse or otherwise effectively expose the adsorbent material
50 into the filter element
26 such that the adsorbent material
50 can have the desired effect on the mainstream smoke drawn through the filter element
26. Accordingly, a representative cigarette filter element 26 may possess the adsorbent
material
50 within at least one component or segment of the filter element in a manner sufficient
to affect the mainstream smoke gas phase removal within the filter element
26.
[0044] In instances, where the adsorbent material
50 comprises a carbonaceous material, the moisture content of the carbonaceous material
(or any other suitable adsorbent) can vary. Typically, the moisture content of the
carbonaceous material or other adsorbent within the filter element, prior to use of
the cigarette incorporating that filter element, is less than about 30 percent, often
less than about 25 percent, and frequently less than about 20 percent, based on the
combined weight of the carbonaceous material and moisture. Typically, the moisture
content of the carbonaceous material or other adsorbent within the filter element,
prior to use of the cigarette incorporating that filter element, is greater than about
3 percent, often greater than about 5 percent, and frequently greater than about 8
percent, based on the combined weightof the carbonaceous material and moisture.
[0045] In some instances, an optional flavoring agent may also be impregnated or otherwise
suspended or included within or on the carrier material
55, in addition to the adsorbent material
50. That is, the carrier material
55 may carry both the adsorbent material
50 and an optional flavoring agent into the filter element
26. As such, the complexity of the formation process for the filter element
26 and/or smoking article may be reduced. For example, in some embodiments, the carrier
material
55 may comprise a polymer matrix material impregnated with the adsorbent material
50, such as, for example, a carbonaceous material, and an optional flavoring agent. Accordingly,
a single insertion device/step may only be needed to insert the adsorbent material
50 and the optional flavoring agent, rather than using multiple insertion devices/ steps
to insert the adsorbent material
50 and the optional flavoring agent (i.e., in the form of a rupturable capsule) into
the filter element
26.
[0046] In other embodiments of the present invention, the adsorbent material 50 may be formed
as a sphere, pellet, capsule, tube or other structured object, with or without the
carrier material 55. For example, the pellets may be manufactured using a wide variety
of extrusion techniques. For instance, such pellets may be manufactured using co-extrusion
techniques (e.g., using a twin screw extruder). For example, a spherical carbon object
may be formed so as to be more easily inserted into the filter material (e.g., cellulose
acetate tow). In some instances, the as-formed adsorbent material 50 may be provided
with a carrier material
55 in the form of an "outer shell" through the application of, for example, food grade
shellac, ethyl cellulose, any suitable hydrophobic coating, or an electrostatically-applied
material, to the adsorbent material object. Such a resulting object may be inserted
with an object-insertion device, as commonly known in the art, such as those used
to insert rupturable capsules containing flavoring agents. As such, one skilled in
the art will appreciate that spheres, capsules, or other forms of the adsorbent material
50 may be inserted in a similar manner (as well as embodiments wherein the carrier material
55 carries the adsorbent material 50). In such em bodiments, for example, one or more
spherical carbon objects may be disposed within the filter material of the smoking
article. Such objects formed as a sphere, pellet, tube, etc. may provide a concentrated
form of the adsorbent material
50 into the filter material. As such, the particles comprising the object may have to
be released and/or dispersed into or otherwise exposed to the filter element
26 to have the desired effect. For example, a force (physical, sound wave, or otherwise)
may be employed while the object is disposed
in situ within the filter element
26 to rupture, crack, or otherwise break, degrade, or disintegrate the adsorbent material
50 and/or carrier material
55 comprising the object so as to disperse or otherwise release the adsorbent material
50 into the filter element
26. This step may occur at any point after which the object has been inserted into the
filter material. That is, this step could be employed late in the manufacturing process,
such as after fabrication of the entire smoking article. In other instances, the step
may occur directly after insertion of the object into the filter rod.
[0047] The size and weight of a capsule may vary. Certain types of capsules are generally
spherical in shape. However, suitable capsules may have other types of shapes, such
as generally rectilinear, oblong, elliptical, or oval shapes. Exemplary generally
spherical capsules have diameters of less than about 3.5 m m, generally less than
about 1.5 mm, often less than about 1 mm, and frequently less than about 0.5 mm. For
example, several capsules can be employed, and those capsules can be in the range
of about 0.25 mm to about 2 mm in diameter. A plurality of very small capsules, commonly
referred to as "microcapsules," can also be incorporated within the filter element
(see, e.g., various microencapsulation options available from Euracli, which protect
the active ingredient (from oxidation, humidity, etc.) and allows the active ingredient
to be released at the desired moment either by rupture of the membrane when subjected
to a precise mechanical action or via a protracted diffusion through the membrane
for an extended effect), wherein such microcapsules may, in some instances, be held
together in a cohesive manner by an appropriate binder material. The total weight
of the capsules contained within the filter may vary, but is typically greater than
about 10 mg, often greater than about 20 mg, and can be greater than about 30 mg.
The total weight of the capsules is typically less than about 200 mg, often less than
about 100 mg, and can be less than 50 mg.
[0048] The number of capsules incorporated into the filter element can vary, depending upon
factors such as the size of the capsules, the character or nature of the payload (i.e.,
adsorbent material, optional flavoring agent or both), the positioning of the capsules
within the filter element, and the like. The number of capsules incorporated within
the relevant region of the filter element can exceed about 5, can exceed about 10,
can exceed about 20, can exceed about 40, and can even exceed about 100. In certain
embodiments, the number of capsules can be greater than about 500, and even greater
than about 1,000. Larger numbers of capsules in certain embodiments can be advantageous
because it can provide the smoker with increased control over the smoke-affecting
properties of the payload.
[0049] Filter elements of the present invention can be incorporated within the types of
cigarettes set forth in
US Pat. Nos. 4,756,318 to Clearman et al.;
4,714,082 to Banerjea et al.;
4,771,795 to White et al.;
4,793,365 to Sensabaugh et al.;
4,989,619 to Clearman et al.;
4,917,128 to Clearman et al.;
4,961,438 to Korte;
4,966,171 to Serrano et al.;
4,969,476 to Bale et al.;
4,991,606 to Serrano et al.;
5,020,548 to Farrier et al.;
5,027,836 to Shannon etal.;
5,033,483 to Clearman et al.;
5,040,551 to Schlatter et al.;
5,050,621 to Creighton et al.;
5,052,413 to Baker et al.;
5,065,776 to Lawson;
5,076,296 to Nystrom et al. ;
5,076,297 to Farrier et al.;
5,099,861 to Clearman et al. ;
5,105,835 to Drewett et al.;
5,105,837 to Barnes et al.;
5,115,820 to Hauser et al.;
5,148,821 to Best et al.;
5,159,940 to Hayward et al.;
5,178,167 to Riggs et al.;
5,183,062 to Clearman et al.;
5,211,684 to Shannon et al.;
5,240,014 to Deevi et al.;
5,240,016 to Nichols et al. ;
5,345,955 to Clearman et al.;
5,396,911 to Casey, III et al.;
5,551,451 to
Riggs et al.;
5,595,577 to Bensalem et al.;
5,727,571 to Meiring et al.;
5,819,751 to Barnes et al.;
6,089,857 to Matsuura et al.;
6,095,152 to Beven et al; and
6,578,584 Beven; and US Pat. Appl. Serial Nos.
US 2007/0215167 to Crooks et al. and
US 2008/00092912 to Robinson et al.. For example, filter elements of the present invention can be incorporated within
the types of cigarettes that have been commercially marketed under the brand names
"Premier" and "Eclipse" by R. J. Reynolds Tobacco Company. See, for example, those
types of cigarettes described in
Chemical and Biological Studies on New Cigarette Prototypes that Heat Instead of Bum
Tobacco, R. J. Reynolds Tobacco Company Monograph (1988) and
Inhalation Toxicology, 12:5, p. 1-58 (2000).
[0050] Cigarette rods typically are manufactured using a cigarette making machine, such
as a conventional automated cigarette rod making machine. Exemplary cigarette rod
making machines are of the type commercially available from Molins PLC or Hauni-Werke
Korber & Co. KG. For example, cigarette rod making machines of the type known as MkX
(commercially available from Molins PLC) or PROTOS (commercially available from Hauni-Werke
Korber & Co. KG) can be employed. A description of a PROTOS cigarette making machine
is provided in
U.S. Patent No. 4,474,190 to Brand, at col. 5, line 48 through col. 8, line 3. ypes of equipment suitable for
the manufacture of cigarettes also are set forth in
U.S. Patent Nos. 4,781,203 to La Hue;
4,844,100 to Holznagel;
5,131,416 to Gentry;
5,156,169 to Holmes et al.;
5,191,906 to Myracle, Jr. et al.;
6,647,870 to Blau et al.;
6,848,449 to Kitao et al.; and
6,904,917 to Kitao et al.; and
U.S. Patent Application Publication Nos. 2003/0145866 to Hartman;
2004/0129281 to Hancock et al.;
2005/0039764 to Barnes et al.; and
2005/0076929 to Fitzgerald et al..
[0051] The components and operation of conventional automated cigarette making machines
will be readily apparent to those skilled in the art of cigarette making machinery
design and operation. For example, descriptions of the components and operation of
several types of chimneys, tobacco filler supply equipment, suction conveyor systems
and garniture systems are set forth in
U.S. Patent Nos. 3,288,147 to Molins et al.;
3,915,176 to Heitmann et al.;
4,291,713 to Frank;
4,574,816 to Rudszinat;
4,736,754 to Heitmann et al. 4,878,506 to Pinck et al.;
5,060,665 to Heitmann;
5,012,823 to Keritsis et al. and
6,360,751 to Fagg etal.; and
U.S. Patent Publication No. 2003/0136419 to Muller. The automated cigarette making machines of the type set forth herein provide a formed
continuous cigarette rod or smokable rod that can be subdivided into formed smokable
rodsof desired lengths.
[0052] Various types of cigarette components, including tobacco types, tobacco blends, top
dressing and casing materials, blend packing densities and types of paper wrapping
materials for tobacco rods, can be employed. See, for example, the various representative
types of cigarette components, as well as the various cigarette designs, formats,
configurations and characteristics, that are set forth in
Johnson, Development of Cigarette Components to Meet Industry Needs, 52nd T.S.R.C.
(Sept., 1998);
U.S. Patent Nos. 5,101,839 to Jakob et al.;
5,159,944 to Arzonico et al.;
5,220,930 to Gentry and
6,779,530 to Kraker;
U.S. Patent Publication Nos. 2005/0016556 to Ashcraftet al.;
2005/0066986 to Nestor et al.;
2005/0076929 to Fitzgerald et al.; and
2007/0056600 to Coleman, III et al.; U.S. Patent Application Serial Nos.
11/375,700, filed March 14, 2006, to Thomas et al. and
11/408,625, filed April 21, 2006, to Oglesby. Most preferably, the entire smokable rod is composed of smokable material (e.g.,
tobacco cut filler) and a layer of circumscribing outer wrapping material.
[0053] As such, another aspect of the present invention comprises an apparatus suitably
configured for incorporating the adsorbent material 50 with the carrier material
55, and, in some instances, an optional flavoring agent
52, forming the filter element of the smoking article by incorporating the carrier material
55 carrying the adsorbent material
50, and/or for forming the smoking article itself having such a filter element incorporating
the carrier material
55 / adsorbent material
50. To that end, apparatuses have been developed for providing filter rods for use in
the manufacture of smoking articles, wherein each rod has one or more forms of the
carrier material
55 (e.g., pellets, capsules, strands, or combinations thereof) carrying the adsorbent
material 50, disposed along the length of the rod, such that, when the rod is subdivided
into rod portions, each rod portion includes at least one form of the carrier material
55 carrying the adsorbent material 50. See, for example,
U.S. Patent No. 7,115,085 to Deal. Such apparatuses can incorporate equipment for supplying a continuous supply of
filter material (e.g., a filter tow processing unit adapted to supply filter tow to
a continuous rod forming unit). A representative apparatus may also include, for example,
an object delivery device such as a hopper and rotating wheel arrangement disclosed
in U.S. Patent Application Publication No.
US 2007/0068540 A1 to Thomas et al., for supplying certain forms of the carrier material
55 carrying the adsorbent material 50 into the filter material. In still other instances,
multiple forms of the carrier material
55 (i.e., pellets and/or strands, or at least one of a pellet or strand in combination
with at least one other of the pellet or strand) can be inserted into the filter material
by an object-insertion unit. Arrangements for inserting such strands/objects into
the filter material are disclosed, for example, in
U.S. Patent Application No. 11/461,941 to Nelson et al. (
US 2008/0029118 A1) and
U.S. Patent Application No. 11/760,983 to Stokes et al..
[0054] A rod-making apparatus
210 as illustrated in FIG.
4, in some instances, may include a forming unit
450 configured to engage the adsorbent material
50 with the carrier material
55 in an on-line or off-line manner to form an insertion object. For example, the forming
unit
450 may be configured to insert the adsorbent material
50 into a tubular or capsular member comprising the carrier material
55, to suspend the adsorbent material
50 in a matrix material comprising the carrier material
55, to engage the adsorbent material
50 with a continuous elongate member comprising the carrier material 55, and/or to wrap a
continuous strip member comprising the carrier material
55 about the adsorbent material
50. Once the insertion object is formed, the insertion object can be delivered from
the forming unit
450 to an insertion unit/ device
214 configured to insert the carrier material
55 carrying the adsorbent material
50 into the filter material. In some instances, the forming unit may be in cooperation
with or otherwise linked to such an insertion unit/device
214 (i.e., on-line vs off-line). Still in other embodiments, the forming unit
450 and the insertion unit/device
214 may be a single unit configured to perform both functions of forming the carrier
material
55 carrying the adsorbent material
50, and inserting the carrier material
55 carrying the adsorbent material
50 into the filter material.
[0055] During the manufacturing process, the filter material may be formed into a continuous
rod having the carrier material
55 carrying the adsorbent material
50 disposed therein and extending along the longitudinal axis thereof. The continuous
rod then may be subdivided at predetermined intervals so as to form a plurality of
filter rods or rod portions such that each rod portion includes at least a portion
of the adsorbent material 50 therein. In instances of the carrier material
55 comprising, for example, a pellet and a strand, the pellets may be disposed at predetermined
positions within and along the filter rod or filter element, while the strand, if
any, extends through the filter rod or filter element.
[0056] As shown in FIG.
4, an exemplary rod-making apparatus
210 may include a rod-forming unit
212 (e.g., a KDF-2 unit available from Hauni-Werke Korber & Co. KG) and an object-insertion
unit
214 suitably adapted to provide for placement of the insertion object(s) along a continuous
length of filter material
40. The continuous length or web of filter material may be supplied from a source (not
shown) such as a storage bale, bobbin, spool or the like. Generally, the filter material
40 may be processed using a filter material processing unit
218. The continuous length of filter material has the carrier material
55 carrying the adsorbent material
50 incorporated therein by the object insertion unit
214, and is then passed through the rod-forming unit
212 to thereby forming a continuous rod 220. The continuous rod 220 can be subdivided
using a rod cutting assembly 222 into a plurality of rod portions 205 each having
at least a portion of the adsorbent material
50 disposed therein. The succession or plurality of rod portions
205 may be collected for use in collection device
226 which may be a tray, a rotary collection drum, conveying system, or the like. If
desired, the rod portions can be transported directly to a cigarette making machine.
[0057] The filter material
40 can vary, and can be any material of the type that can be employed for providing
a tobacco smoke filter for cigarettes. Preferably a traditional cigarette filter material
is used, such as cellulose acetate tow, gathered cellulose acetate web, polypropylene
tow, gathered cellulose acetate web, gathered paper, strands of reconstituted tobacco,
or the like. Especially preferred is filamentary tow such as cellulose acetate, polyolefins
such as polypropylene, or the like. One highly preferred filter material that can
provide a suitable filter rod is cellulose acetate tow having 3 denier per filament
and 40,000 total denier. As another example, cellulose acetate tow having 3 denier
per filament and 35,000 total denier can provide a suitable filter rod. As another
example, cellulose acetate tow having 8 denier per filament and 40,000 total denier
can provide a suitable filter rod. For further examples, see the types of filter materials
set forth in
US Pat. Nos. 3,424,172 to Neurath;
4,811,745 to Cohen et al.;
4,925,602 to Hill et al.;
5,225,277 to Takegawa et al. and
5,271,419 to Arzonico et al.
[0058] Filamentary tow, such as cellulose acetate, may be processed using a conventional
filter tow processing unit 218 such as a commercially available E-60 supplied by Arjay
Equipment Corp., Winston-Salem, N.C. Other types of commercially available tow processing
equipment, as are known to those of ordinary skill in the art, may similarly be used.
Normally a plasticizer such as triacetin or carbowax is applied to the filamentary
tow in traditional amounts using known techniques. In one embodiment, the plasticizer
component of the filter material comprises triacetin and carbowax in a 1:1 ratio by
weight. The total amount of plasticizer is generally about 4 to about 20 percent by
weight, preferably about 6 to about 12 percent by weight. Other suitable materials
or additives used in connection with the construction of the filter element will be
readily apparent to those skilled in the art of cigarette filter design and manufacture.
See, for example,
U.S. Patent No. 5,387,285 to Rivers.
[0059] The continuous length of filter material 40 may be pulled through a block 230 by
the action of the rod-forming unit 212, and the carrier material 55 carrying the adsorbent
material 50 may be inserted along the length of and within the web of filter material.
However, the carrier material 55 carrying the adsorbent material 50 may also be introduced
into the filter material at other points in the process, and this exemplary embodiment
is not intended to be limiting in that regard. The filter material may be further
directed into a gathering region
232 of the rod-forming unit
212. The gathering region can have a tongue and horn configuration, a gathering funnel
configuration, stufferor transport jet configuration, or other suitable type of gathering
device. The tongue
232 provides for further gathering, compaction, conversion or formation of the cylindrical
composite from block
230 into an essentially cylindrical (i.e., rod-like) shape whereby the continuously extending
strands or filaments of the filter material extend essentially along the longitudinal
axis of the cylinder so formed. In some instances, the carrier material
55 carrying the adsorbent material 50 may also be placed into the filter material in
the gathering region
232, as appropriate.
[0060] The filter material
40, which has been compressed into a cylindrical composite, is received further into
the rod-forming unit
212. The cylindrical composite is fed into wrapping mechanism
234, which includes endless garniture conveyer belt
236 or other garniture device. The garniture conveyer belt
236 is continuously and longitudinally advanced using advancing mechanism
238 such as a ribbon wheel or cooperating drum so as to transport the cylindrical composite
through wrapping mechanism
234. The wrapping mechanism provides a strip of wrapping material
28 (e.g., non-porous paper plug wrap) to the outer surface of the cylindrical composite
in order to produce the continuous wrapped rod
220. In some instances, the carrier material
55 carrying the adsorbent material
50 may also be engaged with the filter material in the wrapping or garniture region
232, as appropriate. For example, the elongate member, as otherwise disclosed herein,
may be in the form of a wrapping material
28 having the carrier material
55 carrying the adsorbent material
50 attached thereto or otherwise engaged therewith.
[0061] Generally, the strip or web of wrapping material
28 may provided from rotatable bobbin
242. The wrapping material may be drawn from the bobbin, trained over a series of guide
rollers, passed under block
230, and enter the wrapping mechanism
234 of the rod-forming unit. The endless garniture conveyer belt
236 transports both the strip of wrapping material and the cylindrical composite in a
longitudinally extending manner through the wrapping mechanism
234 while draping or enveloping the wrapping material about the cylindrical composite.
[0062] The seam formed by an overlapping marginal portion of wrapping material has adhesive
(e.g., hot melt adhesive) applied thereto at applicator region
244 in order that the wrapping material can form a tubular container for the filter material.
Alternatively, the hot melt adhesive may be applied directly upstream of the wrapping
material's entry into the garniture of the wrapping mechanism
234 or block
230, as the case may be. The adhesive can be cooled using chill bar
246 in order to cause rapid setting of the adhesive. It is understood that various other
sealing devices and other types of adhesives can be employed in providing the continuous
wrapped rod.
[0063] The continuous wrapped rod
220 passes from the sealing device and is subdivided (e.g., severed) at regular intervals
at the desired, predetermined length using cutting assembly
222 which includes as a rotary cutter, a highly sharpened knife, or other suitable rod
cutting or subdividing device. It is particularly desirable that the cutting assembly
does not flatten or otherwise adversely affect the shape of the rod. The rate at which
the cutting assembly severs the continuous rod at the desired points is controlled
via an adjustable mechanical gear train (not shown), or other suitable device. The
rate at which the carrier material
55 carrying the adsorbent material
50 is inserted into the continuous web of filter material may be in a direct relationship
to the speed of operation of the rod-making machine. The insertion unit can be geared
in a direct drive relationship to the drive assembly of the rod-making apparatus.
Alternatively, the insertion unit
214 can have a direct drive motor synchronized with the drive assembly of the rod-forming
unit. In some instances, the insertion unit
214 may be configured to be in communication with an inspection/detection system
247, for example, in the form of a feedback loop, whereby some defects detected by the
inspection/detection system
247 may be eliminated by adjusting the upstream insertion unit
214. In light of the relationship of the rate of object insertion and the rod-making machine,
embodiments of the present invention are also directed to maintaining or increasing
the production rate of the rod-making machine, without adversely affecting the placement
of the carrier material
55 carrying the adsorbent material
50 within the filter material.
[0064] The insertion unit
214 may include a rotatable insertion member
248 having the shape of a wheel, which may be positioned so as to rotate in a vertical
plane. The insertion unit
214 may also include a hopper assembly
252 and/or other transfer device for feeding or otherwise providing transfer of various
forms of the carrier material
55 (such as, for example, pellets) to insertion member
248. As the insertion member
248 rotates, the carrier material
55 on the peripheral face of the wheel is brought into contact with the filter material
40 within the block
230, where the carrier material 55 is ejected from the pockets into the gathered filter
material
40. Details of such an object-insertion arrangement are further detailed, for example,
in
U.S. Patent No. 7,115,085 to Deal;
U.S. Patent No. 4,862,905 to Green, Jr. et al. (i.e., insertion of individual strand portions); U.S. Patent Application Publication
No.
US 2007/0068540 A1 to Thomas et al. (i.e., insertion of capsules);
U.S. Patent Application No. 11/461,941 to Nelson et al. (i.e., insertion of continuous strands); and
U.S. Patent Application No. 111760,983 to Stokes et al. (i.e., insertion of continuous strands).
[0065] Such object-insertion apparatuses may include, for example, a tongue or tongue portion
configured to gather the supply of filter material into a continuous rod and/or an
insertion unit for inserting a tubular member having the adsorbent material
50 therein into the filter material. In some instances, various forms of the carrier
material
55 may be serially attached or otherwise serially engaged with each other so as to form
a continuous chain, wherein the insertion unit
214 may be configured to place the continuous chain into the filter material. Certain
forms of the carrier material
55 may also be attached or otherwise engaged with an elongate member, wherein the elongate
member may comprise, for example, a strand, and the carrier material
55 is thus strung together by the strand. Multiple forms of the carrier material
55 (i.e., pellets and/or strands) or at least one of a pellet or strand in combination
with at least one other of the pellet or strand may be inserted into the filter material
by the insertion unit
214. One arrangement for inserting a strand into the filter material is disclosed, for
example, in
U.S. Patent Application No. 11/461,941 to Nelson et al.. another example, the elongate member may also be configured to extend laterally
(i.e., as a two dimensional sheet). As such, the rod-forming apparatus
210 may include a garniture device configured to wrap the elongate member having the
adsorbent material
50 attached thereto about the filter material such that the elongate member forms a
wrap encompassing the filter material and the adsorbent material
50 such as disclosed in
U.S. Patent Application No. 11/760,983 to Stokes et al., which is incorporated herein by reference.
[0066] After insertion of the carrier material
55 carrying the adsorbent material
50 into the continuous rod of filter material, the adsorbent material may be released
from the carrier material and into the filter material. For example, the carrier material
55 may be dissolved, disintegrated, degraded, or otherwise destroyed so as to release
and/or disperse the adsorbent material
50 into the filter material so as to allow the adsorbent material 50 to have the desired
effect on the mainstream smoke drawn through the filter element. The release of the
adsorbent material into the filter material may occur before or after the continuous
rod has been severed into filter segments (e.g., filter element 26). Such release
can occur during the manufacturing process. In some embodiments, an adsorbent material
releasing unit
400 may be provided downstream in the production line from the insertion unit
214, wherein the adsorbent material releasing unit
400 may be configured to interact with the carrier material 55
in situ within the filter element so as to release the adsorbent material
50 into the filter material using, for example, a thermal process, an ultrasonic process,
or any other suitable mechanism for releasing the adsorbent material
50 from the carrier material
55.
[0067] More particularly, the adsorbent material
50 may be, for example, plasticized (i.e., moistened to form a "paste") such that the
resulting object is resilient, flexible, and/or otherwise capable of being handled
(see, e.g.,
US Pat. No. 4,862,905 to Green, Jr. et al.). Once the object is inserted into the filter material, the adsorbent material 50
can then be processed into a releasable form, for instance, by a heating and/or drying
procedure applied to the filter element having the object therein. That is, the heating/drying
process may cause the plasticizer to be removed from the object, which then becomes
brittle or otherwise breakable. The filter element can then be mechanically processed,
for example, through opposed rollers, through an "impact" process (i.e., sonic vibration,
heating/cooling cycles, etc.), and/or through an irradiation procedure (i.e., microwave
energy causing the expansion of liquid/gas associated with the object, leading to
the breakdown of the object structure).
[0068] In some instances, various forms of the adsorbent material 50 (i.e., strands, beads,
pellets, capsules, or combinations thereof) may be disposed in a closed cell foam
as the carrier material
55, wherein, once inserted into a filter element
20, may be irradiated or heated to break down the foam and release the adsorbent material
therefrom. Alternately, the carrier material
55 may comprise an open cell foam, wherein, for example, air and/or physical force may
be used to release the adsorbent material
50 once the object is inserted into the filter element
20.
[0069] In other instances, the carrier material
55 may be provided, for example, in the form of a breakable capsule, a "capsule-in-capsule,"
or a strand, formed of a water-or other liquid-soluble polymer and configured to carry
the adsorbent material 50. Such a soluble polymer may comprise, for example, polylactic
acid, polyvinyl alcohol (PVA), starches and/or starch-based polymers, carrageenans,
polyvinyl acetate, hydroxypropylcellulose, pullulan, carboxymethylcellulose and its
salts (i.e., alkali metal salts), alginates and their salts, gelatin, and/or any other
suitable polymers or combinations thereof. Because the releasable form of the carrier
material 55 causes the dispersion of the adsorbent material, thereby allowing the
mainstream smoke to pass through the filter element and interact with the adsorbent
material, the object can be relatively larger than previous "solid state" objects
inserted into filter elements (i.e., relatively larger than between about 2 mm and
about 3.5 mm).
[0070] In controlling this process, a control system may include appropriate control hardware
and/or software. An exemplary control system
290 can incorporate, for example, a Siemens 315-2DP Processor, a Siemens FM352-5 Boolean
Processor and a 16 input bit/16 output bit module. Such a system can utilize a system
display
293, such as a Siemens MP370 display. An exemplary rod-making unit
212 may include controls configured, for a rod of desired length, to adjust the speed
of the knife of the severing unit to be timed relative to the speed of continuous
rod formation. In such instances, a first encoder
296, by way of connection with the drive belt of the rod-making unit, and the control
unit
299 of the insertion unit, may provide a reference of the knife position of the cutting
assembly relative to the wheel position of the insertion unit. Thus, the first encoder
296 may provide one manner of controlling the speed of rotation of the wheel of the insertion
unit relative to the speed at which continuous web of filter tow passes through the
rod-making unit. An exemplary first encoder
296 is available as a Heidenhain Absolute 2048 encoder.
[0071] In one embodiment of the invention, the adsorbent material 50 and the carrier material
55 are both in the form of a fiber, with the adsorbent material fiber comprising or
incorporating an adsorbent material as defined herein. The fibers can comprise conventional
staple fiber as well as substantially continuous structures, such as continuous filaments.
The fibers of the invention can be hollow or solid, and can have a substantially round
or circular cross section or non-circular cross sections (e.g., oval, square, rectangular,
multi-lobed, and the like). The fibers can be in the form of a single thread or filament
or in the form of a multiple thread or filament structure, such as in the form of
a yarn or other structure wherein multiple filaments are bonded, twisted, or entangled
together. Where the fibers are twisted, bonded, or entangled together, the fibers
can be adapted for unraveling after insertion into a filter so as to increase the
available surface area of the adsorbent fiber. The fibers can be formed by any fiber-forming
process known in the art, including extrusion, melt-spinning, solution spinning, and
the like. The color of each fiber can vary, but the adsorbent fiber will often appear
black where the adsorbent fiber is a carbonaceous fiber as described herein.
[0072] The fibers used for the adsorbent material 50 or the carrier material 55 can be constructed
of natural or synthetic materials. Exemplary natural fibers include cotton, linen,
jute, hemp, cotton, wool, and wood pulp. Exemplary synthetic polymers that can be
used to form the fibers include polyamides, polyamines, polyimides, polyacrylics,
polycarbonates, polydienes, polyepoxides, polyesters, polyethers, polyfluorocarbons,
polyolefins, polyphenylenes, silicon containing polymers, polyurethanes, polyvinyls,
polyacetals, polyarylates, modified cellulosic fibers (e.g., cellulose acetate), copolymers
thereof, terpolymers thereof, and mixtures thereof. Non-limiting examples of specific
polymeric materials useful as the fiber material according to the present invention
include the following: Nylon 6, Nylon 6/6, Nylon 12, polyaspartic acid, polyglutamic
acid, polyacrylamide, polyacrylonitrile, esters of methacrylic acid and acrylic acid,
polybisphenol A carbonate, polypropylene carbonate, polybutadiene, polyisoprene, polynorbonene,
polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate,
polycaprolactone, polyglycolide, polylactide, polyhydroxybutyrate, polyhydroxyvalerate,
polyethylene adipate, polybutylene adipate, polypropylene succinate, polyethylene
glycol, polybutylene glycol, polypropylene oxide, polyoxymethylene, polytetramethylene
ether, polytetrahydrofuran, polyepichlorohydrin, urea-formaldehyde, melamine-formaldehyde,
phenol formaldehyde, polyethylene, polypropylene, polybutylene, polybutene, polyoctene,
polyphenylene oxide, polyphenylene sulfide, polyether sulfone, polyphenylene ether
sulfone, polydimethyl siloxane, polycarbomethyl silane, polyvinyl butyral, polyvinyl
alcohol, esters and ethers of polyvinyl alcohol, polyvinyl acetate, polystyrene, polymethylstyrene,
polyvinyl chloride, polyvinyl pyrrolidone, polymethyl vinyl ether, polyethyl vinyl
ether, polyvinyl methyl ketone, polyethylene-co-vinyl acetate, polyethylene-co-acrylic
acid, polybutylene terephthalate-co-polyethylene terephthalate, and polylauryllactam-block-polytetrahydrofuran.
[0073] The adsorbent material
50 can be incorporated into the adsorbent fiber in any manner known in the art, including
by adhering adsorbent particles to the fiber, by imbedding or suspending adsorbent
particles within the fiber, or by forming a fiber and then chemically altering the
fiber such that an adsorbent material is formed (e.g., carbonization of a fiber).
In one embodiment, the adsorbent fiber is constructed of a carbonaceous material (i.e.,
a carbon fiber).
[0074] Carbon fibers can be described as fibers obtained by the controlled pyrolysis of
a precursor fiber. Since carbon is typically difficult to shape into fiber form, commercial
carbon fibers are often made by extrusion of a precursor material into filaments,
which is followed by carbonization, usually athigh temperature. Common precursors
for carbon fibers include rayon, acrylic fibers (such as polyacrylonitrile or PAN),
and pitch (which can include isotropic pitch and anisotropic mesophase pitch, as well
as meltblown pitch fibers). Other precursors, such as cellulose, may also be converted
to carbon fibers. KYNOL™ novoloid fibers (available from American Kynol, Inc., Pleasantville,
NY), are high-performance phenolic fibers that are transformed into activated carbon
by a one-step process combining both carbonization and activation. Forming carbon
fibers from rayon or acrylics generally consists of stabilization, carbonization,
and graphitization, each taking place at successively higher temperatures, to sufficiently
remove non-carbon species, such as oxygen, nitrogen, and hydrogen. Preparation of
fibers using pitch also typically includes stabilization and carbonization; however,
pitch is typically spun as part of the carbon fiber forming process, whereas pre-formed
fibers from rayon or acrylics can be used directly. Activation can sometimes add yet
further production steps. Sources of carbon fibers include Toray Industries. Toho
Tenax, Mitsubishi, Sumitomo Corporation, Hexcel Corp., Cytec Industries, Zoltek Companies,
and SGL Group.
[0075] Carbon fibers are often classified in three separate ways. First, they can be classified
based on modulus and strength. Examples include ultra high modulus (UHM) fibers (modulus
>450 Gpa); high modulus (HM) fibers (modulus between 350 and 450 Gpa); intermediate
modulus (IM) fibers (modulus between 200 and 350 Gpa); low modulus, high tensile (HT)
fibers (modulus <100 Gpa and tensile strength >3.0 Gpa); and super high tensile (SHT)
fibers (tensile strength >4.5 Gpa). Second, carbon fibers can be classified based
on the precursor material used to prepare the fiber(e.g., PAN, rayon, pitch, mesophase
pitch, isotropic pitch, or gas phase grown fibers). Third, carbon fibers can be classified
based on the final heat treatment temperature. Examples include Type-I, high heat
treatment (HTT) fibers (final heat treatment temperature above 2,000 °C), Type-II,
intermediate heat treatment (IHT) fibers (final heat treatment temperature around
1,500 °C), and Type-III low heat treatment (LHT) fibers (final heat treatment not
greater than 1,000 °C). Any of the above classifications of carbon fibers could be
used in the present invention.
[0076] Examples of starting materials, methods of preparing carbon-containing fibers, and
types of carbon-containing fibers are disclosed in
U.S. Patent Nos. 3,319,629 to Chamberlain;
3,413,982 to Sublett et al.;
3,904,577 to Buisson;
4,281,671 to Bynre et al.;
4,876,078 to Arakawa et al.;
4,947,874 to Brooks et al.;
5,230,960 to lizuka;
5,268,158 to Paul, Jr.;
5,338,605 to Noland et al.;
5,446,005 to Endo;
5,482,773 to Bair;
5,536,486 to Nagata et al.;
5,622,190 to Arterbery et al. ; and
7,223,376 to Panter et al.; and
U.S. Pat. Publication Nos. 2006/0201524 to Zhang et al. and
2006/023111 to Newbery et al.. Disclosure around PAN-based carbon fibers particularly (including manufacturers
thereof) is provided in the report to congress entitled "Polyacryionitrile (PAN) Carbon
Fibers Industrial Capability Assessment: OUSD(AT&L) Industrial Policy" (October 2005),
available on-line at http://www.acq.osd.mil/ip/docs/ pan_ carbon_fiber_report_to_congress_10-2005.pdf
[0077] The size of the carrier fiber and the adsorbent fiber (e.g., the carbon fiber) can
vary without departing from the invention. Typically, fiber sizes vary from about
0.5 denier to about 20 denier. The size of the adsorbent fiber will often depend,
at least in part, on the desired amount of adsorbent in the filter element. For example,
the size of the adsorbent fiber can be determined based on the desired weight of adsorbent
in the filter, such as the weight ranges for carbonaceous materials set forth herein.
[0078] The carrier fiber and the adsorbent fiber (e.g., the carbon fiber) can be connected
or associated with each other for purposes of insertion into a cigarette filter material
using any of a variety of methods, including wrapping, intertwining or weaving the
two fiber types together, bonding the fiber types together using an adhesive or binder,
co-extruding the fibers, or tying the fiber types together using a separate connecting
element, such as a separate thread or clip. Each composite fiber structure (i.e.,
combination of a carrier fiber and an adsorbent fiber) can include one or multiple
fibers of each type, meaning each fiber structure can include, for example, I to about
20 carrier fibers and 1 to about 20 adsorbent fibers.
[0079] In another embodiment of the invention, the filter material incorporates a fiber
material that is degradable, meaning the fiber is capable of undergoing degradation
or decomposition, for example through chemical reaction that breaks down the fiber
into decomposition products, under environmental conditions associated with disposal
of the fiber material. One exemplary type of degradation is biodegradation. As used
herein, the term "biodegradable fiber" refers to a polymeric fiber material that degrades
under aerobic and/or anaerobic conditions in the presence of bacteria, fungi, algae,
and other microorganisms to carbon dioxide/methane, water and biomass, although materials
containing heteroatomscan also yield other products such as ammonia or sulfur dioxide.
"Biomass" generally refers to the portion of the metabolized materials incorporated
into the cellular structure of the organisms present or converted to humus fractions
indistinguishable from material of biological origin. Exemplary biodegradable fibers
include, without limitation, cellulosic or other organic plant-derived fibers (e.g.,
cotton, wool, cedar, hemp, bamboo, kapok, or flax), polyvinyl alcohol, aliphatic polyesters,
aliphatic polyurethanes, cis-polyisoprene, cis-polybutadiene, polyhydroxy alkanoates,
polyanhydrides, and copolymers and blends thereof. The term "aliphatic polyester"
refers to polymers having the structure -[C(O)-R-O]
n-, wherein n is an integer representing the number of monomer units in the polymer
chain and R is an aliphatic hydrocarbon, preferably a C1-C10 alkylene, more preferably
a C1-C6 alkylene (e.g., methylene, ethylene, propylene, isopropylene, butylene, isobutylene,
and the like), wherein the alkylene group can be a straight chain or branched. Exemplary
aliphatic polyesters include polyglycolic acid (PGA), polylactic acid (PLA) (e.g.,
poly(L-lactic acid) or poly(DL-lactic acid)), polyhydroxy butyrate (PHB), polyhydroxy
valerate (PHV), polycaprolactone (PCL), and copolymers thereof.
[0080] In certain embodiments, the biodegradable fiber is a bamboo fiber or a PLA fiber.
Suitable bamboo fibers are described, for example, in
U.S. Pat. No. 7,313,906 to Zhou et al., which is incorporated by reference herein. Bamboo fibers are commercially available
from China Bambro Textile Co., Ltd. PLA fibers can be derived from corn or made synthetically.
Suitable PLA fibers are described in
U.S. Pat. No. 7,445,841 to Kaijiyama et al., and are commercially available from Nature-Works LLC.
[0081] The degradable fiber can be utilized in the form of a single strand or as part of
a multi-strand yarn structure. In certain embodiments, the fibrous material can be
used in the form of a sheet. The degradable fiber can be used in combinations containing
multiple fiber types, such as degradable fiber materials of different types woven
together or otherwise combined into a unitary structure or combinations of degradable
fibers with non-degradable fibers and/or adsorbent fibers woven together or otherwise
combined into a unitary structure (e.g., combining bamboo fibers, cotton fibers, and
carbon fibers into a single fiber structure such as a single yarn structure). Alternatively,
multiple fiber types could be combined or mixed within a single fiber strand.
[0082] Where the fiber is described as comprising a particular type of fiber material, thefiberoften
will be comprised primarily of the given fiber material (e.g., above about 50% by
weight based on the total weight of the fiber) or consist essentially of the fiber
material (e.g., above about 90% by weight) or consist virtually entirely of the fiber
material (e.g., above about 98% by weight or about 100% by weight). For example, a
fiber described as a "bamboo fiber" can incorporate relatively minor amounts of bamboo
fibrous material (e.g., in combination with other types of fibrous materials or in
combination with additives), or be comprised primarily of bamboo fibrous material,
or consist essentially of bamboo fibrous material, or consist virtually entirely of
bamboo fibrous material.
[0083] The degradable fibers can act as a carrier fiber for an adsorbent material (e.g.,
a carbon fiber) as described herein, or as a carrier for other additives adapted to
alter the flavor or aroma of a smoking article, or as a carrier for both an adsorbent
material and a flavor/aroma additive. Alternatively, the inherent properties of the
degradable fiber itself may alter the character or nature of the smoke passing through
the filter. Exemplary flavoring agents or aroma agents include any solid or liquid
composition that can be incorporated into a fiber structure by, for example, absorption,
adhesion, or physical entanglement within a fibrous structure. The additives can be
any composition capable of altering the character or nature of the smoke passing through
the filter material, such as by action of a flavorant or a deodorizing agent. Exemplary
additives include natural or synthetic flavorants that can alter the flavor and/or
aroma of mainstream smoke, and the character of the flavors imparted thereby may be
described, without limitation, as fresh, sweet, herbal, confectionary, floral, fruity
or spice. Specific types of flavors or aromas include, but are not limited to, vanilla,
coffee, chocolate/cocoa, cream, mint, spearmint, menthol, peppermint, wintergreen,
eucalyptus, lavender, cardamon, nutmeg, cinnamon, dove, cascarilla, sandalwood, honey,
jasmine, ginger, anise, sage, licorice, lemon, orange, apple, peach, time, cherry,
strawberry, and any combinations thereof. See also,
Leffingwell et al., Tobacco Flavoring for Smoking Products, R. J. Reynolds Tobacco
Company (1972). Flavorings also may include components that are considered moistening, cooling
or smoothening agents, such as eucalyptus. These flavors may be provided neat (i.e.,
alone) or in a composite (e.g., spearmint and menthol, or orange and cinnamon). Exemplary
deodorizing agents include any composition adapted to mask or remove tobacco smoke
aroma. One exemplary composition comprises inorganic salts and odor adsorbents such
as described in
U.S. Pat. No. 7,407,922 to Leskowitz. Another deodorizing composition contains a mandarin orange essential oil fraction
such as described in
U.S. Pat. No. 7,434,586 to Higashi et al...
[0084] The degradable fiber can be incorporated into a filter material in the same manner
as described herein for the carrier fiber/adsorbent material embodiments. For example,
the degradable fiber could be utilized as the carrier fiber in the composite fiber
structures set forth in FIGS. 5 and 6. Alternatively, the degradable fiber can be
imbedded in a filter material without a second fiber structure. For example, a degradable
fiber comprising a flavoring agent could be added to a filter material. In yet another
embodiment, the degradable fiber, with or without additives as described herein, can
be incorporated into any of the wrapping materials utilized in a smoking article filter,
such as in the plug wrap or tipping material.
[0085] In another embodiment, the degradable fiber can be replaced with a non-degradable
fiber, such as any of the numerous synthetic fiber materials described herein that
are not typically viewed as degradable in nature (e.g., polyethylene terephthalate
or polypropylene). The non-degradable fiber can be used in any of the applications
described herein for degradable fibers. Both the degradable fibers and the non-degradable
fibers can be derived from natural materials, synthetic materials, or materials of
a natural origin that have been chemically modified.
[0086] The number of degradable or non-degradable fibers imbedded within a filter element
can vary. Typical ranges of the number of fiber insertions within a filter element
segment include 1 to about 500 fiber insertions, more typically 1 to about 100, and
often 1 to about 50.
[0087] FIG. 5 illustrates one example of a composite fiber structure 60 imbedded within
a filter segment 32. Although multiple composite fiber structures 60 are set forth
in FIG. 5, the number of composite fiber structures can vary. An exemplary range of
the numberof composite fiber structures 60 incorporated into a filter 26 is 1 to about
500, more typically 1 to about 100, and often 1 to about 50. The composite fiber structures
60 can be included in a single segment 32 of a multi-segment filter 26 as shown in
FIG. 5, or the composite fiber structures can be imbedded within a filter element
comprising only a single segment or can extend throughout multiple sections of a multi-segment
filter. The composite fiber structures 60 can extend linearly in the longitudinal
direction of the cigarette filter as shown in FIG. 5, or can extend transverse to
the longitudinal axis of the filter element or can be randomly dispersed at various
angles throughout the filter segment. As shown in FIG. 6, the composite fiber structure
60 can include at least one carrier fiber 62 and at least one adsorbent fiber 64.
[0088] As shown in FIGS. 5 and 6, one method of connecting the two fiber types is to wrap
the adsorbent fiber
64 around the carrier fiber
62. The number of wraps of the adsorbent fiber
64 per unit of length of the carrier fiber
62 can vary, and will depend on a number of factors including the desired amount of
adsorbent material in the filter element. An exemplary range of wrappings of the adsorbent
fiber
64 around the carrier fiber
62 is 1 to about 50 circumferential wrappings of the adsorbent fiber per inch of carrier
fiber.
[0089] Many modifications and other embodiments of the invention will come to mind to one
skilled in the art to which this invention pertains having the benefit of the teachings
presented in the foregoing description; and it will be apparent to those skilled in
the art that variations and modifications of the present invention can be made without
departing from the scope of the invention. Therefore, it is to be understood that
the invention is not to be limited to the specific embodiments disclosed and that
modifications and other embodiments are intended to be included within the scope of
the appended claims. Although specific terms are employed herein, they are used in
a generic and descriptive sense only and not for purposes of limitation.