FIELD OF INVENTION
[0001] The present invention relates generally to a filter element for a smoking article
and to a smoking article including such a filter element.
BACKGROUND OF THE INVENTION
[0002] Filter elements for smoking articles are generally known in the art. Such filter
elements are basically used to screen out filterable materials in the smoke generated
during smoking.
[0003] The invention is mainly directed to filter elements for conventional smoking articles,
such as cigarettes. However, with respect to the present invention, the terms "smoking
article" and "smoking" are intended to include both conventional smoking articles,
such as cigarettes, where tobacco is combusted in order to generate inhalable smoke,
as well as electronic smoking or vaping devices, such as e-cigarettes or shishas,
where a respective liquid is vaporized or atomized in order to generate inhalable
vapor. Such vapor is also referred to as "smoke" below.
[0004] US 3,438,381 relates to a tobacco smoke filter having formed therein a plurality of longitudinal
tunnels each having a roughened wall structure. The tunnels are coated with a viscous
substance, such as honey, to trap noxious ingredients in the smoke.
[0005] TW 2011/32303 A discloses a charcoal filter characterized by comprising add-on charcoal on the surfaces
of charcoal-containing papers and folding inside the papers.
[0006] DE 34 44 991 A1 relates to filter cartridge for smokers' articles, such as tobacco pipes, cigarette
and cigar tips, consisting of a spirally-designed core of porous material and a casing
enclosing the latter. The multi-turn spiral body which forms the central core consists
of a porous adsorptive organic material composed of albumen-containing matter, to
which is added if necessary a proportion of active carbon particles, the spiral body
being coated on its surface with active carbon particles.
[0007] US 2005/133053 A1 and
WO 2004/080217 A1 disclose smoking articles which involve the use of a copper-exchanged molecular sieve
catalyst that is capable of removing NO and/or NO2 from mainstream smoke are provided.
The copper-exchanged molecular sieve catalyst comprises a microporous molecular sieve
substrate having pores with an average diameter of from about 3 AA to about 15 AA,
where at least some of the pores of the microporous molecular sieve substrate contain
Cu
+2 ions. Methods for making cigarette filters and smoking articles using the copper-exchanged
molecular sieve catalyst, as well as methods for smoking a cigarette comprising the
copper-exchanged molecular sieve catalyst, are also described in these documents.
[0008] Smoking sensation can be influenced by filter elements in various ways. It is an
object of the present invention to suggest a new filter element which provides both
effective filtering action and satisfying smoking sensation.
[0009] This object is solved by a filter element with the features of the independent claim.
Preferred embodiments and further developments are described with respect to the dependent
claims.
SUMMARY OF THE INVENTION
[0010] In accordance with one aspect of the present invention there is provided a filter
element for use in a smoking article. The filter element is formed from a conventional
filter material, such as cellulose acetate. The filter element includes a cavity that
is devoid of filter material, wherein a surface of the cavity is at least partially
provided with at least one adsorbent. According to a first variant, the respective
surface is partially or completely provided with one adsorbent.
[0011] According to an alternative second variant, the surface of the cavity may be provided
with a first adsorbent in a first area of the surface and with a second adsorbent
that is different from the first adsorbent in a second area of the surface, which
second area at least partially differs from the first area.
[0012] The adsorbent can be at least one of a group of adsorbents including activated carbon,
zeolites, alumina, silica, silica gel, ion exchange resins, polyester resins, sepiolite,
and carbon species, such as impregnated carbon, activated carbon fibres, or highly
activated carbon. Further suitable adsorbents and/or catalysts that are known in the
art for filtering smoke or removing components from smoke can be used.
[0013] The cavity forms a channel that completely extends through the filter element and
at least partially along a longitudinal direction of the filter element. Preferably,
the cavity or channel extends along a direction along which smoke is drawn during
operation of a smoking article including the filter element, i.e. when the user draws
or puffs on the smoking article. With respect to an arrangement of the filter element
in a smoking article, according to a first variant, the cavity or channel extends
into the filter element from a mouth side. According to an alternative second variant,
the channel or cavity may extend into the filter element from a rod side.
[0014] The cavity or channel devoid of filter material, during smoking, allows at least
a certain amount of smoke to proceed through the filter element without being filtered,
i.e. with original taste that is not altered by passing filter element material. Thereby,
smoking sensation can be enhanced.
[0015] On the other hand, due to the provision of the adsorbent on the inner surface of
the filter element facing the cavity, still a certain filtering or retention effect
can be provided with respect to the portion of the smoke that passes through the cavity
or channel, and not through the filter material surrounding the cavity or channel.
Still further, providing the adsorbent on the inner surface of the cavity, and not
embedded into the filter material results in a lower pressure drop compared to a solution
in which the adsorbent is embedded into the filter material.
[0016] Form and dimension of the cavity or channel can vary. Needless to say that the above
mentioned effect of the cavity or channel increases with proportional to the size
or volume of the cavity in relation to the size or volume of the filter element, i.e.
the filter material surrounding the cavity or channel. It is also possible to provide
more than one cavity or channel. Thereby, in particular the area of active surface,
i.e. surface that is provided with the adsorbent, can be increased, which raises the
retention effect of the adsorbent.
[0017] One or more channels may e.g. extend in parallel along a longitudinal direction of
the filter element, which generally has a circular-cylindrical form. Also the channel
or channels can have a circular-cylindrical form, and can partially, in the form of
a blind hole, or completely, in the form of a through hole, extend into/through the
filter element.
[0018] According to a first embodiment, which is not part of the invention, the cavity or
channel is formed directly in the filter element, i.e. the surface of the filter element
facing the cavity is formed by filter material. With respect to this embodiment, the
adsorbent is directly applied to the inner surface of the cavity, i.e. to the filter
material in this area.
[0019] According to a second embodiment, which is part of the invention, the cavity or channel
is a tube that is formed from a preferably self-supporting, sheet-like tube material.
According to this embodiment, the cavity or channel has a wall separate from the filter
material of the filter element. In general, a tube material differs form the filter
material. However, the tube can also be formed by the same material, such as cellulose
acetate. Providing such a tube in advance may serve to simplify the production of
the inventive filter element. The tube is formed as a single central or inner core
of the filter element, which central core, in the finished filter element, is surrounded
by filter material.
[0020] Suitable tube materials are e.g. paper materials or polymeric materials known in
the art. The tube material can include one or a plurality of layers, e.g. two to three
paper layers. Specifically, according to the invention, at least the inner surface
of the tube material facing the cavity of the tube is at least partially provided
with the adsorbent. The adsorbent can be applied to the respective surface by any
suitable application technology.
[0021] According to a variant, the tube material may already include the adsorbent. In particular,
charcoal paper may be used as tube material or as a layer of a multilayered tube material.
In case the tube material includes multiple layers, at least the innermost layer of
the multiple layers, i.e. the layer that faces the cavity of the tube, includes the
adsorbent.
[0022] According to a third embodiment, a cavity or channel directly formed in the filter
element can partially be lined with a lining material corresponding to the tube material.
The adsorbent may be applied to or integrated into the lining material as described
above with respect to the tube material.
[0023] According to a further embodiment, it is possible to color or print the tube material
or lining material, at least on the surface facing the cavity, in order to achieve
visual differentiation and recognizability.
[0024] An inventive smoking article includes an above described filter element.
[0025] According to a preferred embodiment, the smoking article, in the form of a conventional
cigarette, includes a wrapped tobacco rod and a filter. The filter consists of or
includes at least one of the inventive filter elements. The wrapped tobacco rod and
the filter are connected by a tipping paper which overwraps the filter and a part
of the wrapped tobacco rod.
[0026] According to a preferred embodiment, the filter includes at least a first filter
element and a second filter element of the above described type, wherein a surface
of the first filter element facing the cavity of the first filter element is provided
with a first adsorbent, and wherein a surface of the second filter element facing
the cavity of the second filter element is provided with a second adsorbent that is
different from the first adsorbent.
[0027] The characteristics, features and advantages of this invention and the manner in
which they are obtained as described above, will become more apparent and be more
clearly understood in connection with the following description of exemplary embodiments,
which are explained with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In the drawings, same element numbers indicate same elements in each of the views:
- Figure 1A
- is a schematic cross-sectional illustration of an exemplary filter element;
- Figure 1B
- shows the filter element of Fig. 1A in front view;
- Figure 2
- is a schematic cross-sectional illustration of an exemplary filter element;
- Figure 3A
- is a schematic cross-sectional illustration of an exemplary filter element according
to a first variant of a third embodiment;
- Figure 3B
- is a schematic cross-sectional illustration of an exemplary filter element according
to a second variant of the third embodiment;
- Figure 4
- is a schematic cross-sectional illustration of an exemplary filter element according
to the invention;
- Figure 5A
- is a schematic cross-sectional illustration of an exemplary filter element;
- Figure 5B
- shows the filter element of Fig. 5A in front view;
- Figure 6A
- is a schematic cross-sectional illustration of an exemplary smoking article including
the filter element of Fig. 4;
- Figure 6B
- is a schematic cross-sectional illustration of an exemplary smoking article including
the filter element of Fig. 4 as a first filter element and a variant of the filter
element of Fig. 4 as a second filter element; and
- Figure 6C
- is a schematic cross-sectional illustration of an exemplary smoking article including
the filter element of Fig. 2.
[0029] The figures are generally not drawn in scale, but only exemplarily indicate the elements
of the respective filter elements and smoking articles.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Figure 1A is a schematic cross-sectional illustration of an exemplary filter element
10. Figure 1B shows the filter element 10 of Fig. 1A in front view.
[0031] The filter element 10 is formed from a conventional filter material 20, such as cellulose
acetate. Other filter materials known in the art can likewise be used. The filter
material 20 may be wrapped in a plug wrap (not shown). The filter element 10 has a
circular-cylindrical form. Similar forms can also be used. The length of the filter
element 10 (in the longitudinal direction L) can vary between about 5mm and 40mm,
preferably between 6mm and 30mm. The diameter D of the filter element 10 may also
vary between about 2mm and 15mm, preferably between 4mm and 10mm.
[0032] The filter element 10 includes a cavity (or channel) 30, which extends into the filter
element 10 along the longitudinal direction L. The cavity 30 is devoid of filter material
20. Form and size of the cavity can vary. The cavity 30 can e.g. have the form of
a blind hole, as in Fig. 1A, and extend into the filter element up to a certain depth,
depending on the length of the filter element. Preferably, the depth of the cavity
30 is at least 1/3 of the length of the filter element 10. The cavity can also be
circular-cylindrical. An inner diameter d may vary, depending on the diameter D of
the filter element 10. The cross-sectional area of the cavity 30 should be at least
3mm
2, preferably between 10mm
2 and 30mm
2. In other words, in case the cavity is circular-cylindrical, the diameter of the
cavity should be at least 1mm, preferably between 3mm and 7mm.
[0033] At least part of the inner surface of the cavity 30 is provided with an adsorbent
40. One or more adsorbents can be provided on the surface of the cavity 30. Adsorbents
can e.g. be selected from a group including activated carbon, zeolites, alumina, silica,
silica gel, ion exchange resins, polyester resins, sepiolite, and carbon species,
such as impregnated carbon, activated carbon fibres, or highly activated carbon. Further
suitable adsorbents and/or catalysts that are known in the art for filtering smoke
or removing components from the smoke can be used.
[0034] The adsorbent 40 can be applied to the inner surface of the filter element facing
the cavity, which surface is formed by filter material 20, by any suitable application
technology.
[0035] Figure 2 is a schematic cross-sectional illustration of an exemplary filter element
110.
[0036] The filter element 110 of Fig. 2 mainly differs from the filter element 10 in Fig.
1A in that the cavity 130 now forms a channel that completely extends through the
filter element 110 along the longitudinal direction. Further, not only part of the
inner surface of the cavity 130 is provided with the adsorbent, but essentially the
entire surface.
[0037] Figures 3A and 3B are a schematic cross-sectional illustrations of a first and second
variant of an exemplary filter element 210 according to the invention.
[0038] In contrast to the filter elements 10, 110 according to Fig. 1 and 2, in the filter
elements 210, 210' according to Fig. 3A, 3B, the cavity 130 is provided by a tube
formed from a tube material 50. The tube forms a single central or inner core of the
filter element 210, 210', which inner core is surrounded by filter material 20. The
tube material 50 can e.g. be a paper material or a suitable polymeric material.
[0039] According to the first variant shown in Fig. 3A, the inner surface of the tube material
that faces the cavity of the tube is provided with one adsorbent 40.
[0040] In contrast, according to the second variant shown in Fig. 3B, a first area of the
inner surface of the tube material 50 facing the cavity of the tube is provided with
a first adsorbent 40, while a second area of the inner surface of the tube material
facing the cavity is provided with second adsorbent 40' different from the first adsorbent
40. The first area and the second area may partially overlap.
[0041] Needless to say that respective variants, including different areas of the surface
of the filter element facing the cavity being provided with different adsorbents 40,
40', are applicable also with respect to Fig. 1, 2 described above and to Fig. 4,
5. The number of different areas/different absorbents may vary and is not limited
to two.
[0042] Preferably, the tube material 50 is self-supporting, so that the tube can be formed
in advance and has a predefined stability with respect to collapsing. The thickness
of the tube material 50, defining a thickness of a wall of the tube, can vary, e.g.
between about 0.1mm to 1mm.
[0043] Figure 4 is a schematic cross-sectional illustration of an exemplary filter 310 element.
[0044] This differs from the embodiments Fig. 3A, 3B in that in the filter element 310 the
adsorbent 40 is not only applied to the inner surface of the tube material facing
the tube, but the tube material 150 itself already includes the absorbent 40, i.e.
the adsorbent 40 is integrated or embedded into the tube material 150. Charcoal paper
would e.g. represent a respective tube material 150.
[0045] Figure 5A is a schematic cross-sectional illustration of an exemplary filter element
410 according to a fifth embodiment. Figure 5B shows the filter element of Fig. 5A
in front view.
[0046] The filter element 410 of Fig. 5 differs from the filter element 310 of Fig. 4 (and
the other filter elements described above) in that a plurality of cavities or channels
230, 231, 231, 233 is included in the filter element 410. The number of cavities or
channels may vary, e.g. between 1 and 5. When using a plurality of channels, the sum
of the surface areas of the channels can be increased compared to the provision of
only one channel having the same cross-sectional area as the sum of the cross-sectional
areas of the plurality of channels.
[0047] Needless to say that also in the embodiments according to Fig. 1 to 3B a plurality
of channels or cavities can be included into the respective filter elements.
[0048] Figure 6A is a schematic cross-sectional illustration of an exemplary smoking article
including the filter element of Fig. 4; Figure 6B is a schematic cross-sectional illustration
of an exemplary smoking article including the filter element of Fig. 4 as a first
filter element and a variant of the filter element of Fig. 4 as a second filter element;
and Figure 6C is a schematic cross-sectional illustration of an exemplary smoking
article including the filter element of Fig. 2.
[0049] Figure 6A illustrates, in a longitudinal view, a smoking article 80 in the form of
a cigarette. The cigarette comprises a wrapped tobacco rod 60, which includes an amount
of a tobacco blend wrapped in a cigarette paper (not shown), and a filter. The filter
is composed of the filter elements 510 and 310, where the filter element 310 is the
filter element described above with reference to Fig. 4. The filter element 510 simply
consists of a suitably filter material, e.g. the filter material 20 discussed above,
e.g. cellulose acetate, which can be wrapped in a plug wrap (not shown).
[0050] The filter 510, 310 is connected to the wrapped tobacco rod 60 by a tipping paper
70, which overwraps the filter, i.e. the filter elements 510, 310, and a part of the
wrapped tobacco rod 60. As shown in Fig. 6A, the filter can be designed as a filter
having more than one segment, namely the filter elements 510, 310. The ordering of
these filter elements, along the longitudinal direction of the smoking article can
be changed. Further, any one of the filter elements 10, 110, 210, 410, 510 may be
used instead of the filter element 310 in the embodiment according to Fig. 6A.
[0051] The smoking article 180 shown in Fig. 6B differs from the smoking article according
to Fig. 6A in that instead of the filter element 510 (without cavity) a second inventive
filter element 310' forms part of the filter. The filter element 310' differs from
the filter element 310 by the adsorbent 40' included in the tube material 150', which
differs from the absorbent 40 included in the tube material 150 of the filter element
310. According to this embodiment, different effects that can be achieved by different
adsorbents can be combined.
[0052] Apparently, also more than two filter elements including different adsorbents can
be combined in this way. In this context, also filter elements without tube material,
as described e.g. with reference to Fig. 2, and/or filter elements where the adsorbent
is only applied to the tube material (as shown in Fig. 3A) can be used.
[0053] As shown in Fig. 6C with respect to the smoking article 280, the filter can also
only comprise one filter element, e.g. the filter element 110 according to Fig. 2
(or any other filter element described above). In order to achieve an effect similar
to that achieved by the embodiment according to Fig. 6B, instead of the filter element
110 according to Fig. 1, a filter element as described with reference to Fig. 3B may
be used, i.e. a filter element in which different areas of the surface of the filter
element facing the cavity or channel are provided with different adsorbents.
[0054] While this invention has been described in connection with what is presently considered
to be practical exemplary embodiments, it is to be understood that the invention is
not limited to the disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within the scope of the
appended claims.
LIST OF REFERENCE SIGNS
[0055]
- 10, 110, 210, 210', 310, 410, 510
- filter element
- 20
- filter material
- 30, 130, 230, 231, 232, 233
- cavity
- 40, 40'
- adsorbent
- 50, 150, 150'
- tube material
- 60
- tobacco rod
- 70
- tipping paper
- 80, 180, 280
- smoking article
- L
- longitudinal direction
- D, d
- diameter
1. A filter element (10; 110; 210; 210'; 310; 410; 510) for use in a smoking article
(80), the filter element (10) being formed from a filter material (20), such as cellulose
acetate,
wherein the filter element (10) includes a cavity (30; 130) that is devoid of filter
material (20), ,
wherein the cavity (30; 130) forms a channel that completely extends through the filter
element (10; 110) along a longitudinal direction (L) of the filter element (10; 110),
wherein the channel (130) is a tube that is formed from a tube material (50; 150),
which tube material is different from the filter material,
wherein at least an inner surface of the tube material facing the cavity of the tube
is at least partially provided with an adsorbent (40),
wherein the tube is formed as a single central core of the filter element (210; 310).
2. The filter (10) element according to claim 1, wherein the adsorbent (40) is at least
one of a group of adsorbents including activated carbon, zeolites, alumina, silica,
silica gel, ion exchange resins, polyester resins, sepiolite, and carbon species,
such as impregnated carbon, activated carbon fibres, or highly activated carbon.
3. The filter element (210; 310) according to claim 1 or 2, wherein the tube material
(50; 150) is a paper material or a polymeric material.
4. The filter element (310) according to any one of claims 1 to 3, wherein the tube material
(150) includes the adsorbent (40).
5. The filter element according to claim 4, wherein the tube material includes multiple
layers, and wherein the innermost layer of the multiple layers that faces the cavity
of the tube includes the adsorbent.
6. The filter element (310) according to any one of claims 1 to 5, wherein the tube material
(150) comprises or consists of charcoal paper.
7. The filter element according to any one of claims 1 to 6, wherein the filter element
(410) includes a plurality of cavities (230; 231; 232; 233) that are devoid of filter
material (20), wherein a surface of the filter element facing at least one of the
cavities (230; 231; 232; 233) is provided with the adsorbent (40).
8. A smoking article (80; 180; 280), including a filter element (10; 110; 210; 210';
310; 410; 510) according to any one of claims 1 to 7.
9. The smoking article (80) according to claim 8, comprising a wrapped tobacco rod (60)
and a filter (510, 310) including the filter element (310), the wrapped tobacco rod
(60) and the filter (510, 310) being connected by a tipping paper (70) which overwraps
the filter (510, 310) and a part of the wrapped tobacco rod (60).
10. The smoking article (180) according to claim 9, wherein the filter (310, 310') includes
at least a first filter element (310) and a second filter element (310') according
to any one of claims 1 to 7, wherein a surface of the first filter element (310) facing
the cavity of the first filter element (310) is provided with a first adsorbent (40),
and wherein a surface of the second filter element (310') facing the cavity of the
second filter element (310') is provided with a second adsorbent (40') that is different
from the first adsorbent (40).
1. Filterelement (10; 110; 210; 210'; 310; 410; 510) zur Verwendung in einem Rauchartikel
(80), wobei das Filterelement (10) aus einem Filtermaterial (20) wie Celluloseacetat
ausgebildet ist,
wobei das Filterelement (10) einen Hohlraum (30; 130) beinhaltet, der frei von Filtermaterial
(20) ist,
wobei der Hohlraum (30; 130) einen Kanal ausbildet, der sich vollständig durch das
Filterelement (10; 110) entlang einer Längsrichtung (L) des Filterelements (10; 110)
erstreckt, wobei der Kanal (130) ein Rohr ist, das aus einem Rohrmaterial (50; 150)
ausgebildet ist, wobei sich das Rohrmaterial vom Filtermaterial unterscheidet,
wobei mindestens eine dem Hohlraum des Rohres zugewandte innere Oberfläche des Rohrmaterials
zumindest teilweise mit einem Adsorptionsmittel (40) versehen ist,
wobei das Rohr als ein einzelner zentraler Kern des Filterelements (210; 310) ausgebildet
ist.
2. Filterelement (10) nach Anspruch 1, wobei das Adsorptionsmittel (40) mindestens eines
aus einer Gruppe von Adsorptionsmitteln ist, die Aktivkohle, Zeolithe, Aluminiumoxid,
Siliziumdioxid, Kieselgel, lonenaustauscherharze, Polyesterharze, Sepiolith und Kohlenstoffspezies
wie imprägnierte Kohle, Aktivkohlefasern oder hochaktive Kohle beinhaltet.
3. Filterelement (210; 310) nach Anspruch 1 oder 2, wobei das Rohrmaterial (50; 150)
ein Papiermaterial oder ein Polymermaterial ist.
4. Filterelement (310) nach einem der Ansprüche 1 bis 3, wobei das Rohrmaterial (150)
das Adsorptionsmittel (40) beinhaltet.
5. Filterelement nach Anspruch 4, wobei das Rohrmaterial mehrere Schichten beinhaltet,
und wobei die innerste Schicht der mehreren Schichten, die dem Hohlraum des Rohres
zugewandt ist, das Adsorptionsmittel beinhaltet.
6. Filterelement (310) nach einem der Ansprüche 1 bis 5, wobei das Rohrmaterial (150)
Kohlepapier umfasst oder daraus besteht.
7. Filterelement nach einem der Ansprüche 1 bis 6, wobei das Filterelement (410) eine
Mehrzahl von Hohlräumen (230; 231; 232; 233) beinhaltet, die frei von Filtermaterial
(20) sind,
wobei eine Oberfläche des Filterelements, die mindestens einem der Hohlräume (230;
231; 232; 233) zugewandt ist, mit dem Adsorptionsmittel (40) versehen ist.
8. Rauchartikel (80; 180; 280), das ein Filterelement (10; 110; 210; 210'; 310; 410;
510) nach einem der Ansprüche 1 bis 7 beinhaltet.
9. Rauchartikel (80) nach Anspruch 8, umfassend einen umwickelten Tabakstab (60) und
einen Filter (510, 310), der das Filterelement (310) beinhaltet, wobei der umwickelte
Tabakstab (60) und der Filter (510, 310) durch ein Belagpapier (70) verbunden sind,
das den Filter (510, 310) und einen Teil des umwickelten Tabakstrangs (60) umhüllt.
10. Rauchartikel (180) nach Anspruch 9, wobei der Filter (310, 310') mindestens ein erstes
Filterelement (310) und ein zweites Filterelement (310') nach einem der Ansprüche
1 bis 7 beinhaltet, wobei eine dem Hohlraum des ersten Filterelements (310) zugewandte
Oberfläche des ersten Filterelements (310) mit einem ersten Adsorptionsmittel (40)
versehen ist, und wobei eine dem Hohlraum des zweiten Filterelements (310') zugewandte
Oberfläche des zweiten Filterelements (310') mit einem zweiten Adsorptionsmittel (40')
versehen ist, das sich von dem ersten Adsorptionsmittel (40) unterscheidet.
1. Élément de filtre (10 ; 110 ; 210 ; 210' ; 310 ; 410 ; 510) pour utilisation dans
un article à fumer (80), l'élément de filtre (10) étant formé à partir d'un matériau
de filtre (20), tel que de l'acétate de cellulose,
l'élément de filtre (10) comprenant une cavité (30 ; 130) qui est dépourvue de matériau
de filtre (20),
la cavité (30 ; 130) formant un canal qui traverse complètement l'élément de filtre
(10 ; 110) le long d'une direction longitudinale (L) de l'élément de filtre (10 ;
110), le canal (130) étant un tube qui est formé à partir d'un matériau de tube (50
; 150), lequel matériau de tube est différent du matériau de filtre,
au moins une surface intérieure du matériau de tube opposée à la cavité du tube étant
au moins partiellement munie d'un adsorbant (40),
le tube étant formé comme un noyau central unique de l'élément de filtre (210 ; 310).
2. Élément de filtre (10) selon la revendication 1, l'adsorbant (40) étant au moins un
adsorbant sélectionné parmi le groupe se composant de : charbon actif, zéolithes,
alumine, silice, gel de silice, résines léchangeuses d'ions, résines polyester, sépiolite
et composés carbonés, tels que carbone imprégné, fibres de carbone activées ou charbon
hautement actif.
3. Élément de filtre (210 ; 310) selon la revendication 1 ou 2, le matériau de tube (50
; 150) étant un matériau de papier ou un matériau polymère.
4. Élément de filtre (310) selon l'une quelconque des revendications 1 à 3, le matériau
de tube (150) comprenant un adsorbant (40).
5. Élément de filtre selon la revendication 4, le matériau de tube comprenant des couches
multiples, et la couche la plus intérieure des couches multiples qui sont opposées
à la cavité du tube comprenant l'adsorbant.
6. Élément de filtre (310) selon l'une quelconque des revendications 1 à 5, le matériau
de tube (150) comprenant du, ou se composant de, papier au charbon.
7. Élément de filtre selon l'une quelconque des revendications 1 à 6, l'élément de filtre
(410) comprenant une pluralité de cavités (230 ; 231 ; 232 ; 233) qui sont dépourvues
de matériau de filtre (20),
une surface de l'élément de filtre opposée à l'au moins une des cavités (230 ; 231
; 232 ; 233) étant munie de l'adsorbant (40).
8. Article à fumer (80 ; 180 ; 280), comprenant un élément de filtre (10 ; 110 ; 210
; 210' ; 310 ; 410 ; 510) selon l'une quelconque des revendications 1 à 7.
9. Article à fumer (80) selon la revendication 8, comprenant une tige de tabac enveloppée
(60) et un filtre (510, 310) incluant l'élément de filtre (310), la tige de tabac
enveloppée (60) et le filtre (510, 310) étant connectés par un papier manchette (70)
qui suremballe le filtre (510, 310) et une partie de la tige de tabac enveloppée (60).
10. Article à fumer (180) selon la revendication 9, le filtre (310, 310') comprenant au
moins un premier élément de filtre (310) et un deuxième élément de filtre (310') selon
l'une quelconque des revendications 1 à 7, une surface du premier élément de filtre
(310) opposée à la cavité du premier élément de filtre (310) étant munie d'un premier
adsorbant (40), et une surface du deuxième élément de filtre (310') opposée à la cavité
du deuxième élément de filtre (310') étant munie d'un deuxième adsorbant (40') qui
est différent du premier adsorbant (40).