Technical Field
[0001] The present invention relates to a cigarette in which opacity of an outward appearance
of a filter portion is improved.
Background Art
[0002] A cigarette with a filter (hereinafter, referred to simply as a cigarette) has a
structure in which a filter portion and a tobacco portion containing cut tobaccos
are placed opposite to each other at their ends and integrally connected with each
other by wrapping the whole of the filter portion and a base end part of the tobacco
portion with a tipping paper. In recent years, black absorbents such as activated
carbons are dispersed in at least one of a plurality of filter sections constituting
the filter portion of the above described cigarette from a viewpoint of a health risk
or desire of a milder smoking taste. However, such a cigarette has a problem that
the black absorbents in the filter portion can be seen through outwardly.
[0003] As a conventional technology to increase outward opacity of the filter portion, focusing
on the tipping paper arranged as the outermost layer of the filter portion, and increasing
the opacity of the tipping paper generally up to 85% is known by changing a type of
filler, increasing a mixing proportion of filler or using micro-diameter filler (see
Japanese Patent Application KOKAI Publication No.
8-246396, Japanese Patent Application KOKAI Publication No.
10-219599 and Japanese Patent Application KOKAI Publication No.
11-36196).
[0004] However, the tipping papers described in these documents create disadvantages such
as a dramatic decrease in rigidity of the tipping paper (soft paper), a decrease of
bonding force between the fiber and fiber in the tipping paper (paper easily peeled
off) and the like. As a result, wrinkles or a breaking of the tipping paper arises
in a printing process or in a rolling-up process, causing a large amount of paper
dust. In addition, the above described tipping papers are more likely to be wet and
thus, when a consumer puts the filter portion of the cigarette in his (her) mouth,
the above described tipping paper is more likely to be broken due to saliva. Further,
in such a tipping paper having a certain level of opacity, an effect of increasing
opacity by increasing the filler is curbed so that a relatively large amount of filler
is needed to further increase the opacity of the tipping paper.
[0005] Making the tipping paper thicker is effective in increasing opacity without increasing
the filler. However, if the thick tipping paper is used to achieve high opacity, a
difference between an inner circumferential length and an outer circumferential length
in the thick tipping paper becomes large when the thick tipping paper is rolled, so
that a roundness of the filter portion is likely to be distorted and many wrinkles
is likely to be generated on the rolled thick tipping paper.
[0006] On the other hand, there is a tendency to use more black absorbents like activated
carbons responding to a desire of the aforementioned milder smoking taste. Thus, if
it is intended to obtain a white clean impression of the filter portion is intended
to give, it is not necessarily sufficient to increase the opacity of the tipping paper
to 80% to 85%, as disclosed in the above described documents.
Disclosure of Invention
[0007] An object of the present invention is to provide a cigarette having high quality
in which outward opacity of a filter portion is improved to 92% or more, so that black
absorbents of the filter portion are hard to be seen through and a white clean impression
of the filter portion is obtained.
[0008] According to the present invention, a cigarette is provided, the cigarette comprising:
a filter portion including a plurality of filter sections arranged to be integrated
with each other, a material paper winding around each of the filter sections and a
shape-forming paper winding around the integrated filter sections around each of which
the material paper is wound;
a tobacco portion in which tobacco material is rolled by a cigarette paper; and
a tipping paper wound around the entire filter portion and a base end part of the
tobacco portion after placing the filter portion and the tobacco portion opposite
to each other at their ends, so that the filter portion and the tobacco portion are
integrally connected with each other,
wherein at least one of the filter sections contains black absorbents dispersed therein,
the material paper winding around the filter section containing the black absorbents
has opacity of 78% or more, and
the tipping paper has ventilation holes opened in advance in its part positioned on
the filter section containing no black absorbents.
Brief Description of Drawings
[0009]
FIG. 1 is a diagram showing a relationship between a change of outward opacity of
a filter portion (around which a tipping paper is wound and which includes a filter
section in which activated carbons are dispersed) and a degree (visual sensory value)
which indicates how activated carbons in the filter section can be seen through the
tipping paper on the filter portion.
FIG. 2 shows a cigarette including a dual type filter portion according to an embodiment.
FIG. 3 shows a cigarette including a triple type filter portion according to the embodiment.
Best Mode for Carrying Out the invention
[0010] A cigarette according to an embodiment of the present invention will be described
in detail below.
[0011] The cigarette according to the embodiment comprises a filter portion having a plurality
of filter sections arranged to be integrated with each other, a material paper winding
around each filter section and a shape-forming paper winding around the integrated
filter sections around each of which the material paper is wound, and a tobacco portion
in which tobacco material is rolled by a cigarette paper. The filter portion and the
tobacco portion are placed opposite to each other at their ends and integrally connected
with each other by wrapping the whole of the filter portion and a base end part of
the tobacco portion with a tipping paper. At least one of the filter sections contains
black absorbents dispersed therein. The material paper winding around the filter section
containing the black absorbents has opacity of 78% or more. Ventilation holes are
opened in advance in a part of the tipping paper positioned on the filter section
containing no black absorbents.
[0012] The inventors studied a relationship between a change of outward opacity of a filter
portion (a region in which a tipping paper is wound around and which includes a filter
section in which activated carbons are dispersed) and a degree (visual sensory value)
which indicates how activated carbons in the filter section can be seen through the
tipping paper on the filter portion, and obtained a result shown in FIG. 1. In FIG.
1, "a" is a characteristic line when a filter section to which 25 mg of activated
carbons is added per 10 mm is used, "b" is a characteristic line when a filter section
to which 50 mg of activated carbons is added per 10 mm is used and "c" is a characteristic
line when a filter section to which 75 mg of activated carbons is added per 10 mm
is used. Arrows in FIG. 1 indicate opacity of the tipping paper.
[0013] As a result in FIG. 1, shadows of the activated carbons can be easily seen when a
general-purpose tipping paper having opacity (about 78% to 85%) is used and the shadows
becomes denser with an increase of an added amount of the activated carbons. An extremely
high level of opacity of 92% or more is required for a tipping paper to make a level
of opacity of the tipping paper still being less visible than a level of "dimly visible"
at which it is difficult to recognize the shadows if it is not tried enough to see
them through the tipping paper. As described above, it is extremely difficult to make
practically a tipping paper having such opacity.
[0014] Also, as the result, it becomes obviously that outward opacity of the filter portion
of at least 92%, preferably 94%, is needed to realize a level of "dimly visible",
in other words "hardly visible", in the filter portion. In this connection, outward
opacity of the filter portion when the shadows are not able to be seen through at
all is 98%.
[0015] Based on the above described result of FIG. 1, the inventors found that there is
a limit to improve opacity of the filter portion by increasing opacity of the tipping
paper. And, the inventors particularly focus on a material paper wound around each
of filter sections, among a filter wrapping paper (generic name for both of a material
paper and a shape-forming paper) of the filter portion, and produce a cigarette with
a filter portion having outward opacity of 92% or more to produce a white clean impression
of the filter portion while a conventional tipping paper can be used and a filter
ventilation can be maintained.
[0016] That is, the main function required for the filter wrapping paper is a shape-forming
function for a filter and a predetermined permeability. And, since the filter wrapping
paper is hidden by the tipping paper and normally invisible, the filter wrapping paper
has not been required to have high opacity. Requiring the filter wrapping paper to
have such an arbitrarily high level of opacity can be firstly focused on only by the
above described view point of the present inventors and it is difficult even for those
skilled in the art to think of such an idea.
[0017] A permeability required for the wrapping paper is to maintain filter ventilation.
In general, a level of opacity of each of a filter wrapping paper and a tipping paper
and permeability thereof are correlated, and the permeability tends to decrease with
an increase of the level of opacity. That is, the filter wrapping paper with a high
level of opacity has air permeability lower than that of a conventional filter wrapping
paper, so that it is difficult to maintain sufficient filter ventilation.
[0018] As described above, according to the embodiment, a cigarette including a filter portion
having outward opacity of at least 92% while sufficient ventilation being maintained
can be obtained by winding only a material paper with opacity higher (78% or more)
than that of a conventional material paper around a filter section containing black
absorbents, using a conventional paper with high permeability as the material paper
winding around a filter section containing no black absorbents and as a shape-forming
paper winding around all of the filter sections, and further setting opening positions
of ventilation holes of a tipping paper wrapping around the filter portion and the
tobacco portion within a range of the filter section containing no black absorbents.
[0019] Also according to the embodiment, since a general-purpose tipping paper having appropriate
rigidity and thickness and also having a good roll-up characteristic can be used,
there is no need to add a large amount of fillers to the tipping paper or to make
the tipping paper thicker and, therefore an excellent cigarette in which streaks of
wrinkles are hardly visible can be obtained.
[0020] As the plurality of filter sections used in the embodiment, there is, for example
two-sections type (dual type) or three-sections type (triple type).
[0021] The filter section can be formed from, for example, a tow of cellulose acetate fibers.
The tow of cellulose acetate fibers can be bound by treating it with triacetin.
[0022] For example, activated carbons can be used as the black absorbents dispersed in the
filter section. It is preferable that 25 mg or more, more preferably 50 mg or more,
of the black absorbents are dispersed for a length (10 mm) of the filter section.
[0023] The material paper wound around the filter section containing the black absorbents
has opacity of 78% or more. Such a material paper preferably has a composition of,
for example, pulp and fillers such as calcium carbonate, titanium oxide, etc. The
more preferable opacity of the material paper is 85% or more. If opacity of the material
paper is increased excessively, it becomes difficult to make the material paper. Therefore,
it is preferable to set the upper limit of opacity to 95%.
[0024] The material paper wound around the filter section containing the black absorbents
preferably has a thickness of 30µm to 100µm.
[0025] Opacity can be measured by a measuring method of an example described later.
[0026] As the material paper wound around the filter section containing no black absorbents
is a conventional product. For example, the material paper whose opacity is 20% to
40% can be used. The conventional material paper preferably has a thickness of 30µm
to 100µm.
[0027] The shape-forming paper wound around the filter sections around each of which the
material paper is wound and which are arranged to be integrated with each other is
a conventional product. For example, the shape-forming paper having opacity of 20%
to 40% can be used. The shape-forming paper preferably has a thickness of 30µm to
100µm.
[0028] The tipping paper is a conventional product. For example, the tipping paper having
opacity of 78% to 85% can be used. The tipping paper preferably has a thickness of
30µm to 100µm.
[0029] Next, the cigarette according to the embodiment will be described more concretely
with reference to drawings.
[0030] FIG. 2 shows a cigarette having a dual type filter portion according to the embodiment.
FIG. 2(a) is a front perspective view, FIG. 2(b) is a sectional view along a line
b-b in FIG. 2(a) and FIG. 2(c) is a sectional view along a line c-c in FIG. 2(a).
[0031] The cigarette having the dual type filter portion includes a tobacco portion 1 and
a filter portion 2.
[0032] The tobacco portion 1 is formed by rolling a cigarette paper 12 around cut tobaccos
11 in a cylindrical shape.
[0033] As shown in FIGS. 2(b) and 2(c), the filter portion 2 includes a first filter section
21a arranged in a side of the tobacco portion 1 and a second filter section 21b adjacent
to the first filter section 21a.
[0034] As shown in FIG. 2(b), the first filter section 21a is shaped by winding a first
material paper 23a around a tow of acetate fibers or folded nonwoven fabrics of pulp,
in which black absorbents, for example activated carbons 22, are dispersed, to form
a cylindrical shape. As described above, the first material paper 23a has opacity
of 78% or more and the thickness of, for example, 30µm to 100µm.
[0035] As shown in FIG. 2(c), the second filter section 21b is shaped by winding a second
material paper 23b around a tow of acetate fibers or folded nonwoven fabrics of pulp
to form a cylindrical shape. That is, the second filter section 21b contains no black
absorbents. The second material paper 23a is a conventional material paper having,
for example, opacity of 20% to 40% and a thickness of 30µm to 100µm.
[0036] These two filter sections 21a, 21b wound by the material papers 23a, 23b respectively
have their ends placed opposite to each other and are wound and integrated by a shape-forming
paper 24. The shape-forming paper 24 is a conventional shape-forming paper having,
for example, opacity of 20% to 40% and a thickness of 30µm to 100µm.
[0037] The tobacco portion 1 and the filter portion 2 are integrated by placing their ends
to be opposite to each other and by wrapping the whole of an outer circumferential
surface of the filter portion 2 and a part of an outer circumferential surface of
the tobacco portion 1 near the opposed ends with a tipping paper 3. The tipping paper
3 has ventilation holes 31 opened in advance in a part of the tipping paper 3 corresponding
to the second filter section 21b containing no black absorbents and positioned in
a free end side of the filter portion 2, the part extending in a circumferential direction
of the filter portion. The tipping paper 3 is a conventional tipping paper having,
for example, opacity of 78% to 85% and a thickness of 30µm to 100µm.
[0038] FIG. 3 shows a cigarette having a triple type filter portion according to the embodiment.
FIG. 3(a) is a front perspective view, FIG. 3(b) is a sectional view along a line
b-b in FIG. 3(a), FIG. 3(c) is a sectional view along a line c-c in FIG. 3(a) and
FIG. 3(d) is a sectional view along d-d line in FIG. 3A. In FIG. 3, the same reference
numerals indicate members similar to those in FIG. 2 and descriptions thereof are
omitted.
[0039] As shown in FIGS. 3(b), 3(c) and 3(d), the cigarette having the triple type filter
portion includes a filter portion 2 having a first filter section 201a, a second filter
section 201b and a third filter section 201c. The first to third filter sections 201a
to 201c are arranged in this order from a tobacco portion 1.
[0040] As shown in FIGS. 3(b) and 3(d), each of the first and third filter sections 201a,
201c is shaped by winding first or third material paper 203a or 203c around a tow
of acetate fibers or folded nonwoven fabrics of pulp to form a cylindrical shape.
That is, the first and third filter sections 201a, 201c contain no black absorbents.
Each of the first and third material papers 203a, 203c is a conventional material
paper having, for example, opacity of 20% to 40% and the thickness of 30
µm to 100µm.
[0041] As shown in FIG. 3(c), the second filter section 201b arranged between the first
and third filter sections 201a, 201c is shaped by winding a second material paper
203b around a tow of acetate fibers or folded nonwoven fabrics of pulp, in which black
absorbents, for example, activated carbons 202, are dispersed, to form a cylindrical
shape. As described above, the second material paper 203b has opacity of 78% or more
and a thickness of, for example, 30µm to 100µm.
[0042] These three filter sections 201a to 201c wound by the first to third material papers
203a to 203c respectively have their ends placed opposite to each other and are integrated
with each other by wrapping a shape-forming paper 204 thereon. The shape-forming paper
204 is a conventional shape-forming paper having, for example, opacity of 20% to 40%
and a thickness of 30µm to 100µm.
[0043] In a part of the tipping paper 3 wrapping a part of the tobacco portion 1 and the
whole of the filter portion 2 and integrating them with each other, the part corresponding
to the third filter section 201c containing no black absorbents and positioning in
a free end of the filter portion, ventilation holes 31 are opened in advance to be
arranged along a circumferential direction of the part. The tipping paper 3 is a conventional
tipping paper having, for example, opacity of 78% to 85% and a thickness of 30µm to
100µm. Incidentally, the ventilation holes may be opened in advance in another part
of the tipping paper 3 to be arranged in a circumferential direction of the other
part, the other part corresponding to the first filter section 201a positioned in
a side of the tobacco portion 1. Alternatively, the ventilation holes may be opened
in advance in each of both of the parts (two locations) of the tipping paper 3 to
be arranged in the circumferential direction of each of both of the parts, these parts
corresponding to both of the first and third filter sections 201a, 201c.
[0044] Examples of the present invention will be described in detail below.
(Comparative Examples 1 and 2)
[0045] A first filter section (charcoal section) is formed by dispersing coconut shell activated
carbons of the center grain size of 50 meshes in acetate fibers of 3 denier and then
by rolling the acetate fibers with a first material paper to have a circumferential
length of 24.5 mm. An amount of dispersed activated carbons is set to 50 mg for a
length of 10 mm of the filter section.
[0046] In addition, a second filter section without coconut shell activated carbons dispersed
therein is formed by rolling acetate fibers of 3 denier with a second material paper
to have a circumferential length of 24.5 mm.
[0047] The first and second filter sections wound by such material papers are placed opposite
to each other at their ends and then integrally wound by the shape-forming paper,
so that the filter portion of the dual type shown in FIG. 2 is formed.
[0048] The formed filter portion and a tobacco portion formed by rolling cut tobaccos with
a cigarette paper to a cylindrical shape are placed opposite to each other at their
ends, and then the whole of an outer circumferential surface of the filter portion
and a part of an outer circumferential surface of the tobacco portion near to the
opposed end are wrapped by a tipping paper to make them being integrated, so that
the cigarette shown in FIG. 2 is formed. Ventilation holes are opened in advance in
a part of the tipping paper corresponding to the second filter section containing
no black absorbents and positioned in a free end side of the filter portion cigarette
holder side, the ventilation holes being arranged along a circumferential direction
of the filter portion.
[0049] The obtained cigarette has a total length of 55 mm, in which a length of the tobacco
portion is 30 mm and a length of the filter portion is 25 mm (the first filter section
(charcoal filter section): 10 mm, the second filter section: 15 mm).
[0050] In the cigarettes of Comparative Examples 1 and 2, first and second material papers,
a shape-forming paper and a tipping paper individually having a basis weight, a thickness,
a composition and opacity shown in Table 1 below are used.
[0051] Paper quality is measured as described below.
[0052] Before testing these papers, these papers are conditioned for 24 hours or more under
a conditioning environment at 22°C and 50% humidity.
[0053] Their opacities are measured based on JIS P 8148-1993 by an "ISO white-opacity measuring
apparatus WMS-1" manufactured by MURAKAMI COLOR RESEARCH LABORATORY.
[0054] Their thicknesses are measured based on JIS P 8118 by "DIGI-THICKNESS TESTER" manufactured
by Toyo Seiki Seisakusho.
[0055] Measurement results are rounded off to the nearest integers.
[Table 1]
| |
|
Tipping paper |
First material paper |
Second material paper |
Shape-forming paper |
| Comparative Example 1 |
Basis weight (gsm) |
33 |
27 |
27 |
27 |
| Thickness (µm) |
41 |
65 |
65 |
65 |
| Composition (wt%) |
Wood pulp |
86 |
70 |
70 |
70 |
| Rayon |
0 |
30 |
30 |
30 |
| CaCO3 |
2 |
0 |
0 |
0 |
| TiO2 |
12 |
0 |
0 |
0 |
| Opacity |
78 |
40 |
40 |
40 |
| |
|
Tipping paper |
First material paper |
Second material paper |
Shape-forming paper |
| Comparative Example 2 |
Basis weight (gsm) |
40 |
27 |
27 |
27 |
| Thickness (µm) |
41 |
65 |
65 |
65 |
| Composition (wt%) |
Wood pulp |
76 |
70 |
70 |
70 |
| Rayon |
0 |
30 |
30 |
30 |
| CaCO3 |
12 |
0 |
0 |
0 |
| TiO2 |
12 |
0 |
0 |
0 |
| Opacity |
85 |
40 |
40 |
40 |
(Examples 1 and 2)
[0056] Cigarettes having structures similar to those of Comparative Examples 1 and 2, except
that papers having basis weights, thicknesses, compositions and opacities shown in
Table 2 below are used for the first and second material papers, the shape-forming
paper and the tipping paper, are formed. The thickness and opacity of each paper are
measured similarly to those of Comparative Examples 1 and 2.
[Table 2]
| |
|
Tipping paper |
First material paper |
Second material paper |
Shape-forming paper |
| Example 1 |
Basis weight (gsm) |
33 |
33 |
27 |
27 |
| Thickness (µm) |
41 |
41 |
65 |
65 |
| Composition (wt%) |
Wood pulp |
86 |
86 |
70 |
70 |
| Rayon |
0 |
0 |
30 |
30 |
| CaCO3 |
2 |
2 |
0 |
0 |
| TiO2 |
12 |
12 |
0 |
0 |
| Opacity |
78 |
78 |
40 |
40 |
| |
|
Tipping paper |
First material paper |
Second material paper |
Shape-forming paper |
| Example 2 |
Basis weight (gsm) |
33 |
40 |
27 |
27 |
| Thickness (µm) |
41 |
41 |
65 |
65 |
| Composition (wt%) |
Wood pulp |
86 |
76 |
70 |
70 |
| Rayon |
0 |
0 |
30 |
30 |
| CaCO3 |
2 |
12 |
0 |
0 |
| TiO2 |
12 |
12 |
0 |
0 |
| Opacity |
78 |
85 |
40 |
40 |
(Examples 3 and 4)
[0057] Cigarettes having structures similar to those of Comparative Examples 1 and 2, except
that papers having basis weights, thicknesses, compositions and opacities shown in
Table 3 below are used for the first and second material papers, the shape-forming
paper and the tipping paper, are formed. The thickness and opacity of each paper are
measured similarly to those of Comparative Examples 1 and 2.
[Table 3]
| |
|
Tipping paper |
First material paper |
Second material paper |
Shape-forming paper |
| Example 3 |
Basis weight (gsm) |
40 |
33 |
27 |
27 |
| Thickness (µm) |
41 |
41 |
65 |
65 |
| Composition (wt%) |
Wood pulp |
76 |
86 |
70 |
70 |
| Rayon |
0 |
0 |
30 |
30 |
| CaCO3 |
12 |
2 |
0 |
0 |
| TiO2 |
12 |
12 |
0 |
0 |
| Opacity |
85 |
78 |
40 |
40 |
| |
|
Tipping paper |
First material paper |
Second material paper |
Shape-forming paper |
| Example 4 |
Basis weight (gsm) |
40 |
40 |
27 |
27 |
| Thickness (µm) |
41 |
41 |
65 |
65 |
| Composition (wt%) |
Wood pulp |
76 |
76 |
70 |
70 |
| Rayon |
0 |
0 |
30 |
30 |
| CaCO3 |
12 |
12 |
0 |
0 |
| TiO2 |
12 |
12 |
0 |
0 |
| Opacity |
85 |
85 |
40 |
40 |
[0058] For each of the cigarettes obtained in Comparative Examples 1 and 2 and Examples
1 to 4, opacity when the first material paper, the shape-forming paper and the tipping
paper are layered up and opacity when the second material paper, the shape-forming
paper and the tipping paper are layered up are measured similarly to those of the
Comparative Examples 1 and 2.
[0059] Also, for each of the cigarettes obtained in Comparative Examples 1 and 2 and Examples
1 to 4, a degree which indicates how activated carbons can be seen through a part
of each cigarette corresponding to a charcoal filter section is evaluated by the following
sensory test.
[0060] That is, 16 panelists with normal eyesight visually evaluate each cigarette in a
room illuminated in illumination of about 600 lux by common fluorescent lamps.
[0061] The evaluation is indicated by one of 5 degrees, in which how an appearance of the
filter portion originating from activated carbons in the charcoal filter section can
be seen from gray to black. In the visual sensory test by 16 panelists, apparently
different visual sensory values from those of other panelists are canceled.
<Visual sensory value>
[0062]
- 1: Activated carbons are not able to be seen through.
- 2: Activated carbons can be dimly seen through.
- 3: Activated carbons can be rather seen through.
- 4: Activated carbons can be clearly seen through.
- 5: Activated carbons can be considerably seen through.
[0063] The opacities shown above and the visual sensory values are shown in Table 4 below.
[Table 4]
| |
Opacity of tipping paper |
Opacity of first material paper |
Opacity of second material paper |
Opacity of shape-forming paper |
Opacity *1 when these papers being layered |
Visual Sensory value |
| Comparative Example 1 |
78 |
40 |
40 |
40 |
86 |
4 |
| |
|
|
|
86 |
|
| Comparative Example 2 |
85 |
40 |
40 |
40 |
89 |
4 |
| |
|
|
|
89 |
|
| Example 1 |
78 |
78 |
40 |
40 |
92 |
2 |
| |
|
|
|
86 |
|
| Example 2 |
78 |
85 |
40 |
40 |
93 |
2 |
| |
|
|
|
86 |
|
| Example 3 |
85 |
78 |
40 |
40 |
93 |
2 |
| |
|
|
|
89 |
|
| Example 4 |
85 |
85 |
40 |
40 |
94 |
2 |
| |
|
|
|
89 |
|
[0064] Note) The upper part of Opacity *1 shows opacity when the first material paper, the
shape-forming paper and the tipping paper are layered up, and the lower part thereof
shows opacity when the second material paper, the shape-forming paper and the tipping
paper are layered up.
[0065] As apparent from Table 4, in each of Comparative Example 1 using the tipping paper
which has the lower limit of opacity (78%) and Comparative Example 2 using the tipping
paper which has higher opacity (85%), outward opacity obtained by layering the first
material paper, the shape-forming paper and the tipping paper in the filter portion
(first filter section in which activated carbons are dispersed) is lower than 92%
expected as outward opacity. And, the visual sensory value in each of these Comparative
Examples is "4" (Activated carbons can be clearly seen through) which is not preferable
for a quality of visual appearance.
[0066] In the Comparative Examples 1 and 2, the second filter section containing no activated
carbons is wound by the second material paper having air permeability of 10000 CU
and the shape-forming paper. And, even after winding a tipping paper around the second
filter section, a sufficient ventilation effect can be achieved at a part of the tipping
paper corresponding to the second filter section because ventilation holes are opened
in advance in the part of the tipping paper.
[0067] In the Examples 1 to 3, since the first material paper having opacity of 78% to 85%
is used to wind around the first filter section in which activated carbons are dispersed
and the tipping paper having opacity (78%) of the lower limit is used, outward opacity
obtained by overlaying the first material paper, the shape-forming paper and the tipping
paper on the first filter section in which activated carbons are dispersed exceeds
92% expected as outward opacity. As a result of this, a visual sensory value of "2"(Activated
carbons can be dimly seen through) can be obtained to provide a white clean impression
meaning a good quality on a visual appearance.
[0068] In the Example 4, since the first material paper having opacity of 85% is used to
wind around the first filter section in which activated carbons are dispersed and
the tipping paper having high opacity (85%) is used, outward opacity obtained by overlaying
the first material paper, the shape-forming paper and the tipping paper on the first
filter section in which activated carbons are dispersed exceeds 94% expected as outward
opacity to provide a more white clean impression.
[0069] In the Examples 1 to 4, the second filter section containing no activated carbons
is wound by the second material paper having air permeability of 10000 CU and the
shape-forming paper. And, even after winding a tipping paper around the second filter
section, a sufficient ventilation effect can be achieved at a part of the tipping
paper corresponding to the second filter section because ventilation holes are opened
in advance in the part of the tipping paper.