[0001] The present invention relates to a filter for a smoking article and smoking articles
incorporating a filter element.
[0002] Smoking articles, and filters therefore, can vary significantly from one market to
another as a result of many different factors including consumer preference and tradition.
In certain markets there is a preference for a filter having a recess at the mouth
end, which may be used to lengthen the filter as a whole. The recess is achieved by
overwrapping the plug of filtration material with a plugwrap that extends beyond the
end of the plug of filtration material at the mouth end of the filter. In order to
minimise the susceptibility of the overhanging portion of the plugwrap to damage and
deformation, for example as may result from the packaging process or during handling
and smoking by a consumer, a plugwrap which is thicker than a conventional cigarette
plugwrap is used. Such a plugwrap has up to four times the base weight of a conventional
plugwrap and thus is significantly more resistant to deformation and adds a high level
of rigidity at the mouth end of the filter. However, the need for such a thick plugwrap
means that conventional (more economical) plugwrap s cannot be used on filters having
a recessed end and also add significant problems to the process of ventilating the
filter, and in particular to the process of online laser perforation of the filter,
thus not allowing high levels of ventilation to be attained.
[0004] GB 2,203,324 describes a ventilated tobacco smoke filter comprising an upstream core component
and a downstream core component which may be a tube. An adsorbent, e.g. active carbon,
may be located between spaced first and second core components.
[0005] The present invention provides a filter for a smoking article comprising a first
and a second section, the first section being at a mouth end of the filter and comprising
a cylindrical element having a hollow portion extending therethrough and being circumscribed
by a wrapper, and the second section being longitudinally aligned with and adjacent
to the first section and comprising a filtration material. The second section comprises
a particulate material in a circumferential region thereof, the particulate material
extending to the end of the second section immediately adjacent the first section.
[0006] The use of particulate materials, such as carbon or activated carbon, in tobacco
smoke filter elements to reduce vapour phase constituents of smoke has been known
for some while. A known way of including carbon or other additives in filters is to
adhere particles of the additive to a wrapper surrounding the filter element.
GB 2,260,477 and
GB 2,261,152 describe various configurations of additive adhesion. In some circumstances, particulate
carbon, when provided in a mouth end filter section, may be liable to fall out of
the end of the filter. This is highly undesirable as it is possible that particulate
carbon may become loose and enter the mouth of the consumer. The provision of a first
filter section at the mouth end of the filter having a hollow portion extending therethrough
helps to prevent the fall out of the particulate material whilst maintaining the appearance
of a recessed filter.
[0007] The particulate material may extend over the full longitudinal length of the second
section. The particulate material may also extend over the full width of the wrapper.
In this instance the particulate material may cover the entire surface of the wrapper,
although a seam may be left uncovered to allow adhesive to be applied and the wrapper
to be sealed about the filtration material. Alternatively, the particulate material
may extend over only a portion of the longitudinal length of the wrapper. Similarly,
the particulate material may extend over only a portion of the width of the wrapper.
[0008] The particulate material may extend over two or more portions of the second section.
The two or more portions are preferably spaced circumferentially from one another.
[0009] Alternatively, the two or more portions may comprise three, four, five, six, seven
or eight portions.
[0010] In some embodiments, the filtration material of the second section may further comprise
a particulate material interspersed in the filtration material.
[0011] The particulate material of the filtration material may be the same as the particulate
material provided at the circumferential region of the second section of the plugwrap.
Alternatively, the particulate material of the filtration material may be different
from the particulate material provided at the circumferential region of the second
section of the plugwrap.
[0012] In some embodiments, the wrapper may further comprise ventilation means. For example,
the ventilation means may comprise one or more ventilation holes provided in gaps
between the two or more portions.
[0013] The cylindrical element will generally have a thickness (in the radial direction)
sufficient to occlude at least part of the particulate material. In other words, the
cylindrical element acts as a physical barrier located at the mouth end of the particulate
material to prevent the particular material from escaping from the second section
of the filter. The thickness of the cylindrical element may be from 1-4mm, and is
preferably in the range 1-3mm.
[0014] Suitably the cylindrical element is circumscribed by a wrapper, which is preferably
a plugwrap. This plugwrap may have a base weight of less than 50g/m
2, less than 45 g/m
2, less than 40g/m
2, less than 35 g/m
2, less than 30 g/m
2. This plugwrap may have a base weight equivalent to a conventional plugwrap (wrapper),
namely approximately 23 to approximately 27g/m
2.
[0015] A second aspect of the present invention provides a smoking article comprising a
filter according to the invention.
[0016] Preferably the particulate material includes sorbents (e.g. selected from activated
carbon, charcoal, silica gel, sepiolite, alumina, ion exchange material etc.), pH
modifiers (e.g. alkaline materials such as Na
2CO
3, acidic materials), flavourants, other solid additives and mixtures thereof.
[0017] Advantageously the particulate material is selected from a group of relatively high
surface area materials capable of adsorbing smoke constituents without a high degree
of specificity. Suitable general adsorbents can be selected from the group consisting
of carbon, activated carbon, activated charcoal, activated coconut carbon, activated
coal-based carbon or charcoal, zeolite, silica gel, meerschaum, aluminium oxide (activated
or not), carbonaceous resin or combinations thereof.
[0018] An example of a suitable coal-based charcoal is one made from semi-anthracite coal
with a density about 50% greater than coconut-based charcoal (available from Calgon
Carbon, Pittsburgh, PA, WA).
[0019] An example of a suitable carbonaceous resin is one derived from the pyrolysis of
sulphonated styrene-divinyl benzene, such as Ambersorb 572 or Ambersorb 563 (available
from Rohm and Haas). To enhance the efficiency of the general adsorbent metal oxides
or other metal based complexes may optionally be included in or impregnated on the
general adsorbent section.
[0020] In one embodiment, preferably the particulate material used herein is carbon, for
instance activated carbon, or charcoal or other absorbent material. In one embodiment,
preferably the activated carbon is activated coconut carbon.
[0021] Any particulate material used may be a single substance or a mixture, and/or may
be in admixture with other material.
[0022] In one embodiment preferably the particulate material is disposed in two separate
regions spaced circumferentially from one another. Alternatively, the particulate
material may be disposed in 3, 4, 5, 6, 7 or 8 separate regions each spaced circumferentially
from one another. Further, a greater number of regions may be used if required.
[0023] Each separate region or portion of particulate material may be comprised of particulate
material which is the same as or different from the other separate regions. In one
embodiment preferably the particulate material in the separate regions is the same.
[0024] In one embodiment, suitably the particulate material may be applied to two or more
portions of the longitudinal inner face of the wrapper.
[0025] In one embodiment the particulate material is disposed around the inner circumference
of the wrapper such that the wrapper has an overlapping longitudinal edge which is
free of said particulate material and which provides a lapped and stuck seam holding
the wrapper around the core.
[0026] The particulate material may extend continuously over the full longitudinal length
of said wrapper. By continuously it is meant that the particulate material is applied
such that the loading at any one point on the longitudinal length of the wrapper is
the same (or substantially the same) as the loading at any other point on the same
longitudinal length of the wrapper. By continuously it is meant that at no point along
the longitudinal length of the wrapper is there a portion of the wrapper without particulate
material if the particulate material is present at another point along the same longitudinal
length of the wrapper. Preferably, the particulate material is applied longitudinally
to the wrapper (e.g. plugwrap) in a continuous manner. Preferably along the longitudinal
axis of the wrapper the particulate material is present as a continuous stream (i.e.
without breaks or spaces). In other words, the particulate material extends in a continuous
manner along the longitudinal axis of the wrapper.
[0027] The particulate material may extend continuously over the full width of said wrapper.
[0028] In some embodiments the particulate material may be present as patches.
[0029] The wrapper of the filter element is preferably a paper wrapper. Preferably the wrapper
is a conventional plugwrap.
[0030] In one embodiment the wrapper may be a conventional plugwrap which covers 360° of
the core, in which case the plugwrap has a lapped and stuck seam holding the wrapper
around the core.
[0031] In one embodiment, preferably the filter element according to the present invention
has a filtration material comprising particulate material interspersed with the filtration
material and has a plugwrap which covers 360° of the filtration material.
[0032] In another embodiment the wrapper (in particular plugwrap) preferably does not extend
360° around the filtration material. In other words, in one embodiment preferably
the wrapper is a split wrapper. A split wrapper is one which extends circumferentially
about the filtration material, but extends less than 360° around the circumference
of the filtration material. In such an embodiment, there is not lapped and stuck seam
holding the wrapper around the filtration material. Instead, the split wrapper may
be held in place by other known means, such as by bonding the wrapper directly to
the filtration material for instance.
[0033] The wrapper for use in the filter element may be porous or non-porous.
[0034] The wrapper for use in the filter element may be ventilated or unventilated.
[0035] Advantageously the filtration material of the second section may comprise (or consist
of) conventional fibrous cellulose acetate, polypropylene or polyethylene material
or gathered paper material.
[0036] Preferably the filtration material comprises cellulose acetate.
[0037] In one embodiment, the filtration material of the second section is a Dalmatian-type
filter material.
[0038] The particulate material may be interspersed throughout the filtration material.
Alternatively, the particulate material may be interspersed in some parts (but not
all) of the filtration material. The parts may be evenly or unevenly distributed.
[0039] The particulate material adhered to the wrapper may be homogenous - in the sense
that it is made up of substantially the same component (for some embodiments, preferably
all of the same). Alternatively, the particulate material adhered to the wrapper may
be heterogeneous - in the sense that it is made up of two or more different components.
The particulate material adhered to the wrapper may be in contact with the filtration
material. Preferably, some or all of the particulate material adhered to the wrapper
is in contact with the filtration material. For some embodiments, preferably substantially
all of the particulate material adhered to the wrapper is in contact with the filtration
material.
[0040] The filter is preferably interattached with a smokable filler (e.g. tobacco) rod
by way of a tipping wrapper. Advantageously the tipping wrapper is a paper.
[0041] In one embodiment the filter may comprise additional filter section(s). The additional
filter section(s) will be at the tobacco rod end of the filter. Suitably, one, two,
three or more additional filter sections may be provided in the filter. The additional
filter section(s) may be any type of filter section known to those skilled in the
art. Suitably the filter sections are arranged longitudinally of one another with
the end of each filter element abutting the next.
[0042] Suitably the wrapper surrounding the second section of the filter is preferably pre-coated
with the particulate material.
[0043] The particulate material may be adhered to the wrapper by hot melt adhesive (e.g.
various polyester adhesives), high m.p. polyethylene glycol, or emulsion-type adhesive
such as PVA.
[0044] The particulate material may be directly or indirectly adhered to the wrapper. An
example of direct adherance is wherein the particulate material is affixed to the
wrapper (such as the inner surface thereof) by means of a suitable adhesive. An example
of indirect adherance is wherein the particulate material is affixed to an intermediate
layer (which may be made of paper or other suitable support matrix - such as a textile
material - or combinations thereof) by means of a suitable adhesive and wherein the
intermediate layer is affixed to the wrapper (such as the inner surface thereof) by
means of a suitable adhesive.
[0045] Suitably the additional filter section(s) of the filter may be comprised of conventional
fibrous cellulose acetate, polypropylene or polyethylene material or gathered paper
material. The additional filter section(s) may optionally comprise one or more additives,
for instance disposed upon or within the material of the filter element may be further
flavouring materials, as described above, which are released or eluted from the filter
element during use.
[0046] The cylindrical element of the first section at the mouth end may be made from a
variety of materials, for example, cellulose acetate tow, cellulose, paper, cotton,
polypropylene web, polypropylene tow, polyester web, polyester tow or combinations
thereof. It is preferred that the element comprises cellulose acetate.
[0047] In addition, the pressure drop and/or mechanical filtration efficiency of the filter
sections can be selected to achieve the desired smoking mechanics and filtration characteristics
as may be required with the specific product design desired.
[0048] A part of the filter may comprise a catalyst. Advantageously the catalyst facilitates
the conversion of carbon monoxide (CO) to carbon dioxide (CO
2) in the vapour phase of the smoke. It is much by preference that the catalyst is
highly selective for carbon monoxide. Suitably the catalyst may be one of the group
consisting of transition metal oxides, silica, alumina, zeolites, impregnated carbon,
for example, carbon impregnated with metals.
[0049] Suitably the filter and/or smoking article according to the present invention may
comprise ventilation means. For example, the ventilation means may comprise one or
more holes in the wrapper engaged around the filtration material of the second section.
The holes may advantageously be positioned in regions of the wrapper to which the
particulate material is not adhered. Ventilation holes are often formed in filter
wrappers by laser piercing. Carbon granules in the region where ventilation is required
can cause the laser to produce sparks when the holes are being made. Positioning the
ventilation holes in gaps between the portions of particulate material addresses this
problem.
[0050] The ventilation means may comprise perforation holes in the tipping wrapper used
to interattach the filter and the rod of wrapped smokable filler (e.g. tobacco) material.
[0051] Alternatively the ventilation means may be provided by the use of a porous tipping
wrapper used in conjunction with a perforated plugwrap. The porous tipping wrapper
may be porous over its full extent or over only a localised extent, which extent is
in registration with the underlying perforated plugwrap.
[0052] The ventilation means may further be provided at or close to the end of the rod of
wrapped smokable filler (e.g. tobacco) material. The ventilation means may be provided
in the tipping wrapper or in the cigarette paper wrapper enwrapping the smokable filler
(e.g. tobacco) material.
[0053] Suitably, the filter may be attached to a wrapped smokable filler material rod (i.e.
a wrapped tobacco rod for instance) by conventional tipping overwrap to form a smoking
article. The tipping overwrap may be ventilating or non-ventilating overwrap.
[0054] The length of the smoking material rod is advantageously at least 60 mm and the rod
should preferably yield not less than six puffs, and more preferably not less than
seven puffs when smoked under standard machine smoking conditions. The rod is preferably
of uniform cross-sectional shape and dimensions throughout the length of the rod.
[0055] The wrapper enwrapping the smoking article may comprise a burn additive, such as
sodium and/or potassium citrate, for example. Other suitable burn additives, such
as sodium or potassium salts, such as acetate and tartrate; mono-ammonium phosphate,
and di-sodium hydrogen phosphate, for example, will be known to the skilled man. The
burn additive may be present in the range of 0.5-2.5% by weight of the wrapper. The
wrapper may also have a base weight in the range of 20-40g/m
2.
[0056] The wrapper of the smoking article may alternatively or in addition be a non-paper
wrapper, such as the wrappers described in International Patent Applications, Publications
Nos.
WO 96/07336 and
WO 01/41590. Such wrappers assist in the reduction of sidestream smoke components, but still
provide a smoking article which has burning and ashing characteristics similar to
conventional products, i.e. the wrappers allow the smoking article to burn down and
ash in a similar way to conventional products.
[0057] Suitably, the smokable filler material may be tobacco-containing material or a tobacco
substitute material. Preferably the smokable material is a tobacco material. Suitably
the tobacco material comprises one or more of stem, lamina, tobacco dust and reconstituted
tobacco. It is preferred that the tobacco material comprises one or more of the following
types: Virginia or fluecured tobacco, Burley tobacco, Oriental tobacco, reconstituted
tobacco. It is much by preference that the smokable material comprises a blend of
tobacco material. Advantageously the smokable material comprises 10-80% Virginia tobacco,
10-60% Burley tobacco, 0-20% Oriental tobacco, 0-120% reconstituted tobacco and 0-30%
expanded tobacco.
[0058] The term 'carbon' as used herein can be taken to cover a material which is substantially
solely carbon and any carbon precursors, such as carbonaceous material. As used herein
the term carbonaceous includes material which has been pyrolysed, which material preferably
contains carbon, although some incomplete combustion products may still be present.
Ready pyrolysed coconut fibre may, for example, be the carbonaceous material from
which carbon is derived.
[0059] As used herein, the term 'smoking material' or 'smokable filler material' means any
material which can be used in a smoking article. It does not necessarily mean that
the material itself will necessarily sustain combustion.
[0060] As used herein, the term 'smoking article' means any product that is used in the
tobacco industry and includes smokable products or similar products for delivering
an aerosol to the consumer. Smoking articles include cigarettes, cigars, cigarillos
and similar articles.
[0061] In order that the present invention may be clearly understood and readily carried
into effect reference will now be made, by way of example, to the accompanying drawings
in which:
Figure 1 shows a longitudinal cross-sectional view of a filter having a recess at
the mouth end according to the prior art;
Figure 2 shows a longitudinal cross-sectional view of a filter according to one embodiment
of the present disclosure;
Figure 3 shows an end view from the mouth end of a filter according to one embodiment
of the present disclosure;
Figure 4 shows a longitudinal cross-sectional view of a filter according to a further
embodiment of the present invention; and
Figure 5 shows a longitudinal cross-sectional view of a filter according to an alternative
arrangement of the present invention.
[0062] Figure 1 shows a known filter 1 attached to a tobacco rod 2 (only a portion of which
is shown) to form a cigarette. Filter 1 consists of a plug of cellulose acetate 3
(filtation material) circumscribed by a plugwrap 4. The plugwrap 4 is longer than
the plug of cellulose acetate 3 and overhangs the plug of cellulose acetate at the
mouth end of the filter 1 to create a recess having a depth typically of approximately
5mm. The length of overhang of the plugwrap 4 is designated in Figure 1 by the reference
character x. The filter 1 is attached to the tobacco rod by a tipping wrapper 5 in
the conventional manner. The plugwrap 4 is typically a wrapper having a high base
weight, for example 100g/m
2 to provide rigidity to the filter 1.
[0063] Figure 2 shows a filter 1 in accordance with the present disclosure in which a first
section at the mouth end of the filter 1 comprises a tubular plug of cellulose acetate
6 having a hollow central core, designated by reference numeral 7 in Figure 2. The
filter 1 also consists of a second section at the tobacco rod end of the filter 1
and adjacent the first section. The second section comprises a plug of cellulose acetate
filtration material 3 circumscribed by a plugwrap 4, which plugwrap 4 may also circumscribe
the cellulose acetate plug 6 of the first section. Alternatively the plugs 3, 6 may
each be circumscribed by a respective individual plugwrap. The filter 1 is attached
to a tobacco rod 2 to form a cigarette by a standard tipping wrapper 5. The plugwrap
4 and/or the tipping wrapper 5 may be ventilated (not shown) at any point over their
surface and to a varying amount dependent on the particular product. The plug of cellulose
acetate 6 of the first filter section may for instance be 7mm in length and provides
rigidity to the mouth end of the filter 1 and allows a conventional plugwrap 4 to
be used without reducing strength.
[0064] Figure 3 shows the filter of Figure 2 in end view from the mouth end thereof. The
cylindrical plug of cellulose acetate 6 defines a hollow core 7 longitudinally along
the centre of the plug 6. The plug of cellulose acetate filtration material 3 of the
second section can be seen at the far end of the hollow core 7. The thickness of the
cylindrical plug of cellulose acetate 6 is defined by the outer surface of the plug
9 and by the inner surface of the plug 8. This thickness, designated by reference
character z in Figure 3, may vary depending on the desired size of the recess at the
mouth end of the filter 1. The cylindrical plug of cellulose acetate 6 is circumscribed
by a plugwrap (not shown) and is surrounded by a tipping wrapper (not shown) to join
the filter 1 to a tobacco rod in a formed cigarette. The inner-surface of the plug
of the first filter section may be of any desired shape and thus serve to create a
recognizable shape for the hollow core 7.
[0065] The filter 1 of Figure 4 comprises all of the features of Figure 2, and same reference
numerals are used to denote equivalent features, with the addition of a particulate
activated carbon 10 adhered to the inner surface of the plugwrap 4 circumscribing
the plug of cellulose acetate 3 of the second filter section. The carbon 10 extends
the entire longitudinal length of the second section, being for instance 20mm in length.
The thickness of the wall of the plug of cellulose acetate of the first filter section
is sufficient to cover the carbon at the position of abutment between the first and
second filter sections and prevent any carbon 10 becoming loose and escaping into
the first filter section or beyond the mouth end of the filter 1.
[0066] Figure 5 shows a filter 1 which comprises all of the features of Figure 4, with the
alteration in the length of the layer of carbon 10. Particulate activated carbon 10
extends over only a portion of the plugwrap 4 which circumscribes the plug of cellulose
acetate 3 of the second filter section. The carbon 10 extends from the end of the
plug of cellulose acetate 3 nearest the mouth end of the filter 1 to a position part
way along the plug 3 towards the tobacco rod 2.
[0067] Various modifications and variations of the described methods and system of the present
invention will be apparent to those skilled in the art without departing from the
scope of the present invention. Although the present invention has been described
in connection with specific preferred embodiments, it should be understood that the
invention as claimed should not be unduly limited to such specific embodiments. Indeed,
various modifications of the described modes for carrying out the invention which
are obvious to those skilled in the art are intended to be within the scope of the
following claims.
1. A filter (1) for a smoking article comprising:
a first (6) and a second section, the first section (6) being at a mouth end of the
filter and comprising a cylindrical element having a hollow portion (7) extending
therethrough and being circumscribed by a wrapper, and the second section being longitudinally
aligned with and adjacent to the first section and comprising a filtration material
(3),
wherein the second section comprises a particulate material in a circumferential region
thereof, the particulate material extending to an end of the second section immediately
adjacent the cylindrical element of the first section,
wherein the cylindrical element covers the particulate material at the position of
abutment between the first and second sections,
wherein a wrapper (4) surrounds the second section and the particulate material (10)
is adhered to an inner surface of the wrapper.
2. A filter according to Claim 1, wherein the particulate material (10) extends over
a full longitudinal length of the second section.
3. A filter according to Claim 1 or 2, wherein two or more portions of the circumferential
region of the second section comprise particulate material (10).
4. A filter according to Claim 3, wherein the two or more portions are spaced circumferentially
from one another.
5. A filter according to Claim 4, wherein the two or more portions are arranged symmetrically
around the second section.
6. A filter according to any preceding Claim, wherein the particulate material (10) is
an adsorbent.
7. A filter according to Claim 6, wherein the particulate material (10) is activated
carbon.
8. A filter according to any preceding Claim, wherein the second section further comprises
a particulate material (10) interspersed in the filtration material (3).
9. A filter according to any preceding Claim, wherein the cylindrical element has a wall
defined by the outer surface of the element and the hollow portion (7) extending therethorough,
the wall being of a thickness to at least partly occlude the particulate material
in a circumferential region of the second section at the point of abutment of the
first and second sections.
10. A filter according to any preceding Claim, wherein the wrapper circumscribing the
first section (6) is a plugwrap.
11. A filter according to Claim 10, wherein the plugwrap has a base weight of less than
50g/m2.
12. A filter according to any preceding Claim, wherein the cylindrical element of the
first section comprises cellulose acetate.
13. A filter according to any preceding Claim, further comprising at least one additional
filter section at the tobacco rod end of the filter.
14. A smoking article comprising a filter according to any one of claims 1-13.
1. Ein Filter (1) für einen Rauchartikel, bestehend aus:
einem ersten (6) und einem zweiten Abschnitt, wobei sich der erste Abschnitt (6) am
Mundende des Filters befindet und aus einem zylindrischen Element mit einem sich durch
dieses erstreckenden und durch eine Hülle umgebenen hohlen Teil (7) besteht, und der
zweite Abschnitt in Längsrichtung am ersten Abschnitt ausgerichtet ist, sich angrenzend
an den ersten Abschnitt befindet und aus einem Filtermaterial (3) besteht,
in welchem der zweite Abschnitt aus Partikelmaterial in einem zirkumferenziellen Bereich
desselben besteht, wobei sich das Partikelmaterial bis zu einem unmittelbar neben
dem zylindrischen Element des ersten Abschnitts befindlichen Ende des zweiten Abschnitts
erstreckt,
in welchem das zylindrische Element das Partikelmaterial an der Position des Anschlags
zwischen dem ersten Abschnitt und dem zweiten Abschnitt bedeckt,
in welchem eine Hülle (4) den zweiten Abschnitt umgibt und das Partikelmaterial (10)
an einer inneren Oberfläche der Hülle anhaftet.
2. Ein Filter nach Anspruch 1, in welchem sich das Partikelmaterial (10) über die volle
Länge des zweiten Abschnitts in Längsrichtung erstreckt.
3. Ein Filter nach Anspruch 1 oder 2, in welchem zwei oder mehr Teile des zirkumferenziellen
Bereichs des zweiten Abschnitts aus Partikelmaterial (10) bestehen.
4. Ein Filter nach Anspruch 3, in welchem zwei oder mehr Teile zirkumferenziell mit Abständen
zueinander versehen sind.
5. Ein Filter nach Anspruch 4, in welchem zwei oder mehr Teile symmetrisch um den zweiten
Abschnitt herum angeordnet sind.
6. Ein Filter nach einem beliebigen vorhergehenden Anspruch, in welchem das Partikelmaterial
(10) ein Adsorptionsmittel ist.
7. Ein Filter nach Anspruch 6, in welchem das Partikelmaterial (10) Aktivkohle ist.
8. Ein Filter nach einem beliebigen vorhergehenden Anspruch, in welchem der zweite Abschnitt
darüber hinaus aus in das Filtermaterial (3) eingestreutem Partikelmaterial (10) besteht.
9. Ein Filter nach einem beliebigen vorhergehenden Anspruch, in welchem das zylindrische
Element eine Wand besitzt, die durch die äußere Oberfläche des Elements und durch
den sich durch dieses erstreckenden hohlen Teil (7) begrenzt wird, wobei die Wand
eine Stärke aufweist, die zumindest zum Teil das in einem zirkumferenziellen Bereich
des zweiten Abschnitts am Punkt des Anschlags des ersten und zweiten Abschnitts befindliche
Partikelmaterial verdeckt.
10. Ein Filter nach einem beliebigen vorhergehenden Anspruch, in welchem die den ersten
Abschnitt (6) umgebende Hülle ein Filterumhüllungspapier ist.
11. Ein Filter nach Anspruch 10, in welchem das Filterumhüllungspapier ein Basisgewicht
von weniger als 50g/m2 aufweist.
12. Ein Filter nach einem beliebigen vorhergehenden Anspruch, in welchem das zylindrische
Element des ersten Abschnitts aus Celluloseacetat besteht.
13. Ein Filter nach einem beliebigen vorhergehenden Anspruch, ferner bestehend aus mindestens
einem zusätzlichen Filterabschnitt am Tabakende des Filters.
14. Ein Rauchartikel, umfassend einen Filter nach einem beliebigen der Ansprüche 1 - 13.
1. Filtre (1) pour un article à fumer comprenant :
un première (6) et une seconde section, la première section (6) se trouvant à une
extrémité buccale du filtre et comprenant un élément cylindrique comportant une partie
creuse (7) le traversant et entourée par un papier d'enveloppe, et la seconde section
étant alignée longitudinalement avec la première section et jointive avec celle-ci
et comprenant une matière de filtration (3),
dans lequel la seconde section comprend une matière particulaire dans une région circonférentielle
de celle-ci, la matière particulaire s'étendant jusqu'à une extrémité de la seconde
section immédiatement jointive avec l'élément cylindrique de la première section,
dans lequel l'élément cylindrique couvre la matière particulaire à la position de
butée entre les première et seconde sections,
dans lequel un papier d'enveloppe (4) entoure la seconde section et la matière particulaire
(10) est collée à une surface interne du papier d'enveloppe.
2. Filtre selon la revendication 1, dans lequel la matière particulaire (10) s'étend
par-dessus une longueur longitudinale maximale de la seconde section.
3. Filtre selon la revendication 1 ou 2, dans lequel deux ou plusieurs parties de la
région circonférentielle de la seconde section comprennent la matière particulaire
(10).
4. Filtre selon la revendication 3, dans lequel les deux ou plusieurs parties sont espacées
circonférentiellement les unes des autres.
5. Filtre selon la revendication 4, dans lequel les deux ou plusieurs parties sont agencées
symétriquement autour de la seconde section.
6. Filtre selon l'une quelconque des revendications précédentes, dans lequel la matière
particulaire (10) est un adsorbant.
7. Filtre selon la revendication 6, dans lequel la matière particulaire (10) est du charbon
actif.
8. Filtre selon l'une quelconque des revendications précédentes, dans lequel la seconde
section comprend en outre une matière particulaire (10) intercalée dans la matière
de filtration (3).
9. Filtre selon l'une quelconque des revendications précédentes, dans lequel l'élément
cylindrique comporte une paroi définie par la surface externe de l'élément et la partie
creuse (7) le traversant, la paroi étant d'une épaisseur servant à occlure au moins
partiellement la matière particulaire dans une région circonférentielle de la seconde
section au point de butée des première et seconde sections.
10. Filtre selon l'une quelconque des revendications précédentes, dans lequel le papier
d'enveloppe entourant la première section (6) est un papier filtre.
11. Filtre selon la revendication 10, dans lequel le papier filtre a un poids de base
de moins de 50g/m2.
12. Filtre selon l'une quelconque des revendications précédentes, dans lequel l'élément
cylindrique de la première section comprend de l'acétate de cellulose.
13. Filtre selon l'une quelconque des revendications précédentes, comprenant en outre
au moins une section de filtre supplémentaire, à l'extrémité du filtre en contact
avec le bâtonnet de tabac.
14. Article à fumer comprenant un filtre selon l'une quelconque des revendications 1 à
13.