Note: Descriptions are shown in the official language in which they were submitted.
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1
Description
Title: Filter for smoking or vaping article comprising a
nonwoven substrate
Technical field
[0001] A subject of the invention is a filter comprising a nonwoven substrate
having
a low density and comprising natural fibers and a binder. This nonwoven
substrate
is capable of being obtained by a drylaid process. This filter can be used as
filter for
a smoking or vaping article.
Prior art
[0002] A filter for a smoking or vaping article has a right circular
cylindrical shape
and generally comprises an outer envelope of plug wrap paper and a substrate
located within the outer envelope. The filter for a smoking or vaping article,
by virtue
of the substrate, makes it possible to prevent the user from inhaling tobacco
particles
and allows retention of the harmful particulate substances contained in the
smoke
or the aerosol, such as tar.
[0003] Filters are commonly made from cellulose acetate. These cellulose
acetate
filters have a nicotine retention capacity such that the user's perception of
the filtered
smoke is satisfactory. In addition, these filters generate a filtered smoke
having good
organoleptic properties. However, these cellulose acetate substrates degrade
very
slowly and are not dispersible in water. This is particularly harmful since
the filter is
not consumed during the smoking/vaping of a smoking/vaping article and is
regularly found in the environment. Cellulose acetate substrates thus have a
significant environmental impact.
[0004] To limit the environmental impact of conventional filters, it has been
proposed to replace the cellulose acetate with paper. As paper substrates are
biodegradable, they degrade rapidly. However, the nicotine retention capacity
of
filters comprising a paper substrate is such that the user's perception of the
filtered
smoke may not be satisfactory. In addition, the smoke filtered by filters
comprising
a paper substrate may have a drying taste which is unsatisfactory for the
user. The
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user experience provided by these paper substrates is thus not as satisfactory
when
compared with cellulose acetate.
Technical problem
[0005] There is therefore a need for a filter which has a nicotine retention
capacity
of the same order of magnitude as that of a filter comprising a cellulose
acetate
substrate, which provides a satisfactory user experience.
[0006] It is thus to the credit of the inventors to have found that it was
possible to
meet this need by means of a nonwoven substrate.
Summary
[0007] It is proposed a filter comprising a nonwoven substrate comprising
natural
fibers and a binder, in which the natural fibers represent between 70% and
99%, in
particular between 80% and 98%, very particularly between 85% and 98% by
weight
of solids of said nonwoven substrate, the binder represents between 1 /0 and
30%,
in particular between 2% and 20%, very particularly between 2% and 15% by
weight
of solids of said nonwoven substrate, and
characterized in that the nonwoven substrate has a density of between 7 mg/cm3
and 60 mg/cm3, in particular between 8 mg/cm3 and 50 mg/cm3, very particularly
between 10 mg/cm3 and 40 mg/cm3.
[0008] Advantageously, the filter of the invention has a nicotine retention
capacity
of the same order of magnitude as the retention capacities of a filter
comprising a
cellulose acetate substrate. Consequently, the user's perception of the smoke
filtered by the filter of the invention is satisfactory.
[0009] Moreover, the smoke filtered by the filter of the invention has
organoleptic
properties which are satisfactory for the user.
[0010] The nonwoven substrate can also make it possible to produce the filter
of the
invention without a prior shaping step, which is not the case for paper
substrates.
Thus, the process for producing the filter of the invention is simplified.
[0011] According to another aspect, a process is proposed for producing the
filter
of the invention comprising a nonwoven substrate, said process comprising the
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following steps:
a) forming a rod of nonwoven substrate from a nonwoven substrate,
b) wrapping the rod of nonwoven substrate with a sheet of plug wrap paper,
C) depositing an adhesive line, joining the sheet of plug wrap paper to obtain
a rod of filtering material,
d) cutting the rod of filtering material to produce the filter.
wherein the nonwoven substrate is as defined above or is obtained by a process
comprising the following steps:
i) producing a web from natural fibers by a drylaid process,
ii) introducing the binder into the web, and
iii) drying the web resulting from step ii) to obtain the nonwoven substrate.
Description of the embodiments
[0012] It is proposed a filter comprising a nonwoven substrate comprising
natural
fibers and a binder, in which the natural fibers represent between 70% and
99%, in
particular between 80% and 98%, very particularly between 85% and 98% by
weight
of solids of said nonwoven substrate, the binder represents between 1% and
30%,
in particular between 2% and 20%, very particularly between 2% and 15% by
weight
of solids of said nonwoven substrate;
characterized in that the nonwoven substrate has a density of between 7 mg/cm3
and 60 mg/cm3, in particular between 8 mg/cm3 and 50 mg/cm3, very particularly
between 10 mg/cm3 and 40 mg/cm3.
[0013] Compared to the conventional density of paper substrates, which is
greater
than 300 mg/cm3, the density of the nonwoven substrate is very low.
[0014] Without wishing to be bound by any theory, the inventors are of the
opinion
that, by virtue of this low density, the nonwoven substrate of the filter of
the invention
has a higher filter filling power than the filling power of a paper substrate.
This higher
filling power makes it possible to reduce the amount of nonwoven substrate
present
in the filter such that the filter of the invention has a nicotine retention
capacity of the
same order of magnitude as the retention capacity of a filter comprising a
cellulose
acetate substrate.
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[0015] For the purposes of the present application, "nonwoven substrate" (also
referred to as "non-woven substrate") denotes a manufactured sheet consisting
of
a web or ply of directionally or randomly oriented fibers bonded together by
friction
and/or cohesion and/or adhesion.
[0016] Typically, the density of the nonwoven substrate is calculated by
dividing its
gram mage by its thickness.
[0017] The standard ISO 536:2012 can be used to determine the grammage of the
nonwoven substrate. The substrate is conditioned for at least 16 hours at 23 C
and
50% humidity before the measurement.
[0018] To measure the thickness of the nonwoven substrate, it is possible to
use a
dead-weight micrometer comprising a 25 cm2 measuring head with two planar,
parallel and circular pressure surfaces. During the measurement, the nonwoven
substrate is placed between the two pressure surfaces for 10 seconds. The
pressure
exerted between the pressure surfaces during the measurement of the thickness
is
0.5 kPa. The substrate is conditioned for at least 16 hours at 23 C and 50%
humidity
before the measurement.
[0019] The grammage of the nonwoven substrate of the filter of the invention
can
for example be between 20 g/m2 and 60 g/m2, in particular between 23 g/m2 and
57 g/m2, more particularly between 25 g/m2 and 55 g/m2.
[0020] The thickness of the nonwoven substrate of the filter of the invention
can for
example be between 700 pm and 6000 pm, in particular between 1000 pm and
4700 pm, more particularly between 2000 pm and 4500 pm.
[0021] According to one particular embodiment, the nonwoven substrate can have
a density of between 10 mg/cm3 and 40 mg/cm3, and a thickness of between
2000 pm and 4500 pm.
[0022] The person skilled in the art will know how to adapt the grammage and
the
thickness of the nonwoven substrate in order to achieve the desired density.
[0023] For the purposes of the present application, the term "natural fiber"
denotes
a fiber of natural origin which has optionally undergone a chemical treatment,
a
physical treatment, or both, in order to optimize the physical characteristics
thereof.
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[0024] For example, the natural fibers can be chosen from wood fibers, leaf
fibers,
fruit fibers, seed fibers, bast fibers, stalk fibers, reed fibers, and
mixtures thereof, in
particular wood fibers, leaf fibers, seed fibers, bast fibers, and mixtures
thereof,
more particularly wood fibers, bast fibers and mixtures thereof.
5 [0025] Examples of wood fibers which may be present in the nonwoven
substrate
of the filter of the invention can be lyocell fibers (cellulose fibers which
are ground
and dissolved in N-methylmorpholine N-oxide monohydrate for the purpose of
obtaining fibers with a cross section of variable shape (round, oval, cross-
shaped,
circular, lamellar cross section) with calibrated length and mass per unit
length,
which the person skilled in the art can choose depending on their needs),
viscose
fibers (fibers obtained by dissolving cellulose by means of modification of
its
hydroxyl groups by carbon disulfide (CS2) and then its precipitation in the
presence
of sulfuric acid (H2SO4) for the purpose of obtaining fibers with a cross
section of
variable shape (round, oval, cross-shaped, circular, lamellar cross section)
with
calibrated length and mass per unit length, which the person skilled in the
art can
choose depending on their needs), and mixtures thereof, in particular lyocell
fibers,
viscose fibers, and mixtures thereof.
[0026] For the purposes of the present application, "bast fiber" denotes a
plant fiber
contained in the bast of the plants.
[0027] As bast fiber, mention may be made of hemp fiber, Indian hemp fiber,
jute
fiber, kenaf fiber, kudzu fiber, flax fiber, okra fiber, nettle fiber, ramie
fiber, and
mixtures thereof, in particular hemp fiber, flax fiber, and a mixture thereof,
more
particularly flax fiber.
[0028] Typically, the bast fibers may have undergone prior treatment. Thus,
the bast
fibers may be cottonized bast fibers, individualized bast fibers, bast fibers
which
have undergone retting, bleached bast fibers, and mixtures thereof, in
particular
cottonized bast fibers, individualized bast fibers and a mixture thereof.
[0029] For the purposes of the present application, "seed fiber" denotes a
fiber
obtained from seeds of a plant. Examples of seed fibers can be cotton fiber,
kapok
fiber, luffa fiber, milkweed fiber, and mixtures thereof, in particular kapok
fiber.
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[0030] According to one particular embodiment, the natural fibers are chosen
from
lyocell fibers, flax fibers, cottonized flax fibers, cotton fiber and mixtures
thereof, in
particular a mixture of cottonized flax fibers and lyocell fibers.
[0031] According to one particular embodiment, the natural fibers of the
nonwoven
substrate can be a mixture of natural fibers comprising cottonized flax fibers
and
lyocell fibers,
the cottonized flax fibers represent more than 50%, in particular between
70% and 98%, more particularly between 85% and 95% by weight of solids of said
mixture of fibers, and
the lyocell fibers representing less than 50%, in particular between 2% and
30%, more particularly between 5% and 15% by weight of solids of said mixture
of
fibers.
[0032] According to the invention, the natural fibers, before use in the
nonwoven
substrate, can have a length of between 10 mm and 150 mm, in particular
between
15 mm and 100 mm, more particularly between 20 mm and 60 mm.
A drylaid process is particularly suitable for this size of natural fibers.
Thus, the
nonwoven substrate of the filter of the invention of this alternative
embodiment can
be obtained by a drylaid process.
[0033] The length of the natural fibers can be measured by a Classifiber KCF-
V/LS
apparatus from Keisokki. Natural fibers are combed and individualized before
measurement. The sizes of the fibers are measured automatically by an optical
method.
[0034] The natural fibers may also be cut so as to have a length within the
ranges
mentioned above. Conventional cutting techniques which can be used are
guillotine
cutting of natural fibers, grinding of the natural fibers with or without a
system for
removing excessively short and excessively long fibers of air cyclone or
screen type.
[0035] For the purposes of the present application, "binder" denotes a
compound
having properties enabling consolidation of the nonwoven substrate.
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[0036] For example, the binder can be a natural polymer, a synthetic polymer
or
copolymer or a mixture thereof. The natural polymer can be a polysaccharide, a
cellulose derivative, or a mixture thereof. The synthetic polymer can be a
latex.
[0037] The polysaccharide which can be used as binder can be a polysaccharide
or
a polysaccharide derivative. For example, starch, dextrin, gum arabic, and
mixtures
thereof can be used as binder, in particular starch.
[0038] For example, the cellulose derivative can be chosen from ethyl
cellulose,
methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose,
carboxymethyl
cellulose, an alkali metal salt of carboxymethyl cellulose, and mixtures
thereof, in
particular carboxymethyl cellulose.
[0039] As alkali metal of the carboxymethyl cellulose salt, mention may be
made of
potassium, sodium, and magnesium.
[0040] The synthetic polymer or copolymer can, for example, be a polyvinyl
alcohol,
an ethylene-vinyl alcohol, a polyvinyl acetate, a polyvinyl chloride, a
styrene-
butadiene, a polybutadiene, polyacrylics, an ethylene-vinyl acetate, and
mixtures
thereof, in particular polyvinyl alcohol.
[0041] According to another very particular embodiment, the nonwoven substrate
can comprise:
a mixture of fibers comprising between 85% and 95% of cottonized flax
fibers by weight of solids of said mixture of fibers and between 5% and 15% of
lyocell
fibers by weight of solids of said mixture of fibers, and
a binder chosen from starch, polyvinyl alcohol, ethylene-vinyl acetate, which
can represent between 2% and 15%, in particular between 2% and 8% by weight of
solids of said nonwoven substrate,
in which the mixture of fibers can represent between 85% and 98%, in
particular between 92% and 98% by weight of solids of said nonwoven substrate;
and
can have a density of between 10 mg/cm3 and 40 mg/cm3.
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[0042] The nonwoven substrate of this other very particular embodiment can be
obtained by a drylaid process.
[0043] The filter of the invention can be a filter for a smoking or vaping
article.
[0044] For the purposes of the present application, "smoking article" denotes
an
article comprising tobacco and/or any other plant intended to be smoked. For
example, the smoking article may be a machine-manufactured cigarette, a roll-
your-
own cigarette or a make-your-own cigarette.
[0045] Typically, the filter for a smoking article has a right circular
cylindrical shape
and comprises an outer envelope of plug wrap paper for a smoking article, in
particular for a cigarette, and the nonwoven substrate of the filter of the
invention as
defined above located within the outer envelope.
[0046] For the purposes of the present application, "vaping article" denotes
an
article comprising tobacco and/or any other plant intended to be vaped, which
is
intended to be inserted into a device which heats the tobacco and/or the plant
without burning said tobacco/plant and which enables delivery of an aerosol to
a
user. For example, the vaping article can be a tobacco stick.
[0047] Typically, the filter for a vaping article has a right circular
cylindrical shape
and comprises an outer envelope of plug wrap paper for a vaping article, in
particular
for a tobacco stick, and the nonwoven substrate of the filter of the invention
as
defined above located within the outer envelope.
[0048] The filter of the invention can have a density of between 100 mg/cm3
and
200 mg/cm3, in particular between 110 mg/cm3 and 170 mg/cm3, more particularly
between 115 mg/cm3 and 160 mg/cm3.
[0049] Typically, the density of the filter is measured after manufacture of
the filters,
by dividing the mass of the filter by its volume. For a filter having a right
circular
cylindrical shape, the volume of the filter (Vfiiter) is calculated by the
following formula:
Vfilter = Tr*L=k12, in which r denotes the radius of the filter and L denotes
the length of
the filter.
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[0050] The nonwoven substrate of the filter of the invention may not be
crimped
before the formation of the filter. This is highly advantageous since it makes
it
possible to produce a filter while simplifying the production of the filter.
[0051] According to another aspect, the present invention also relates to a
smoking
article comprising a filter as defined above.
[0052] According to another aspect, the present invention also relates to a
vaping
article comprising a filter as defined above.
[0053] The present invention also relates to the use of a nonwoven substrate
as
defined above in a filter, in particular a filter for a smoking article or a
filter for a
vaping article.
[0054] The present invention also relates to a process for producing a filter
for a
smoking or vaping article comprising a nonwoven substrate, said process
comprising the following steps:
a) forming a rod of nonwoven substrate from a nonwoven substrate,
b) wrapping the rod of nonwoven substrate with a sheet of plug wrap paper,
c) depositing an adhesive line, joining the sheet of plug wrap paper to obtain
a rod of filtering material,
d) cutting the rod of filtering material to produce the filter.
wherein the nonwoven substrate is as defined above or is obtained by a process
comprising the following steps::
i) producing a web from natural fibers by a drylaid process, and
ii) introducing the binder into the web,
iii) drying the web resulting from step ii) to obtain the nonwoven substrate.
[0055] The nonwoven substrate, the natural fibers and the binder are as
described
above in relation to the nonwoven substrate.
[0056] In particular, the filter for a smoking or vaping article produced by
the
production process of the invention has a right circular cylindrical shape and
comprises an outer envelope of plug wrap paper for a filter for a smoking or
vaping
article and the nonwoven substrate of the filter of the invention as defined
above
located within the outer envelope.
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[0057] The nonwoven substrate of the filter of the invention can therefore be
obtained by a drylaid process.
[0058] The drylaid process and the airlaid process are two different the
conventional
routes known to the person skilled in the art to produce a web. The person
skilled in
5 the art will know how to adapt the parameters of the drylaid process to
produce the
nonwoven substrate of the filter of the invention.
[0059] The process of the invention can comprise, if need be, before
production
step i), a step i1) of cutting the natural fibers to obtain natural fibers
having a length
within the ranges mentioned above.
10 [0060] Cutting step i1) can be carried out by conventional techniques such
as
guillotine cutting, grinding of the natural fibers with or without a system
for removing
excessively short and excessively long fibers of air cyclone or screen type.
[0061] During introduction step ii), an aqueous dispersion of the binder is
introduced
into the web. This introduction may for example be carried out by
impregnation, such
as impregnation with a size press, by spraying, such as spraying using a
spray, by
surface application, such as surface application by coating or by printing, in
particular by spraying a spray. Advantageously, the spraying will be performed
on
both faces of the web.
[0062] The aqueous dispersion of the binder can be obtained by any technique
known to the person skilled in the art. The person skilled in the art will
know how to
adapt the concentration of binder in the aqueous dispersion to obtain the
desired
content of binder in the nonwoven substrate of the filter of the invention.
[0063] Drying step iii) can, for example, be carried out by a drying device,
such as
a tunnel through which air passes or an infrared ramp.
[0064] This drying step iii) can be carried out at a temperature of between 75
C and
200 C, in particular between 90 C and 170 C, more particularly between 100 C
and
120 C. A temperature within these ranges advantageously makes it possible to
minimize the duration of this drying step iii) while at the same time
minimizing the
deterioration of the natural fibers of the nonwoven substrate, thus optimizing
the
process of the invention.
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[0065] Advantageously, the combination of the introduction step ii) and of the
drying
step iii) makes it possible to improve the cohesion of the natural fibers and
hence to
consolidate the structure of the nonwoven substrate of the filter of the
invention.
[0066] The natural fibers used in production step i) can be a mixture of
natural fibers.
This mixture of natural fibers can be obtained before production step i).
[0067] The natural fibers can be bast fibers which have undergone prior
treatment,
such as cottonized bast fibers, individualized bast fibers, bast fibers which
have
undergone retting and mixtures thereof, in particular cottonized bast fibers,
individualized bast fibers and mixtures thereof.
[0068] The process of the invention can thus comprise, before production step
i), a
step i2) of treating the bast fibers chosen from retting, bleaching,
cottonizing,
individualizing, and a mixture thereof, in particular cottonizing,
individualizing or
individualizing followed by cottonizing.
[0069] Cottonizing is a treatment in which the fibers are refined in order to
pass
through cotton mills. The person skilled in the art knows how to implement a
cottonizing treatment step i2).
[0070] Individualizing is a treatment in which all or some of the fibers of a
set of
fibers are separated from one another. Individualizing can, for example, be
carried
out by combing or by a chemical treatment.
[0071] This treatment step i2) may take place before, after or before and
after
optional cutting step i1).
[0072] For example, the bast fibers may undergo, optionally, individualizing
treatment step i2), cutting step i1) to obtain bast fibers having a length
within the
abovementioned ranges, then optionally cottonizing treatment step i2), in
particular
cutting step i1) to obtain bast fibers having a length within the
abovementioned
ranges, then cottonizing treatment step i2).
[0073] The process may also comprise, between production step i) and
introduction
step ii), a step iii) of compacting the web to obtain a compacted web, this
compacted
web then undergoing introduction step ii).
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[0074] This compacting step iii) can make it possible to reduce the thickness
of the
web in order to control the density of the nonwoven substrate.
[0075] According to another very particular embodiment, the process can
comprise
the following steps:
i) producing a web by a drylaid process from a mixture of natural fibers
comprising between 85% and 95% of cottonized flax fibers by weight of solids
of
said mixture of fibers and between 5% and 15% of lyocell fibers by weight of
solids
of said mixture of fibers,
ii) introducing a binder chosen from starch, polyvinyl alcohol, ethylene-vinyl
acetate or a mixture thereof into the web by spraying an aqueous dispersion of
binder,
iii) drying the web resulting from step ii) to obtain a nonwoven substrate
which can have a density of between 10 mg/cm3 and 40 mg/cm3 and in which the
mixture of fibers can represent between 85% and 98% by weight of solids of
said
nonwoven substrate and binder can represent between 2% and 15% by weight of
solids of said nonwoven substrate.
[0076] Optionally, the nonwoven substrate obtained at step iii) may be
calendered.
[0077] After step iii) and before step a), the nonwoven substrate may be
packed as
bobbin, as roll by a spooling process or in paperboard by a festooning
process.
Examples
[0078] Example 1: Manufacture of the nonwoven substrate
[0079] In the Examples, the air permeability is determined using "FX3300 Lab
Air
IV" Air permeability tester. During the measurements, the tested web is placed
under
the measurement head and we measured the air flow passing through the web at
pressure drop of 200 Pa over the area of 20 cm2. The permeability is measured
in
[cm3/cm2/sec]. For each sample, three measurements were made and the indicated
air permeability is the average value.
[0080] Example 1.1: Nonwoven substrate prepared by a drylaid process and
comprising 95% by weight of solids of said nonwoven substrate of a mixture of
cottonized flax fibers and of lyocell fibers (90% cottonized flax/10% lyocell
by weight
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of solids of the mixture of fibers) and 5% by weight of solids of said
nonwoven
substrate of starch
[0081] The cottonized flax fibers (VERVAEKE FIBRE NV, 22 mm in length) and the
lyocell fibers (1.7 dtex / 38 mm in length from Lenzig) were mixed, opened and
parallelized with a card before being deposited on a forming fabric. A
solution
comprising 5% solids content of starch (Perfectafilm X115 manufactured by
Avebe)
is sprayed onto both sides of the web. The sprayed web is then dried by hot
air oven
at a temperature of between 100 C and 120 C. The content of binder in the web
is
50/0.
[0082] The nonwoven substrate obtained has a density of 11 mg/cm3, a thickness
of 4190 rim, a grammage of 47 g/m2 and an air permeability of 650 c1n3.cm-
2.sec-1.
[0083] All the examples have the same fiber size, with an average length
before
manufacture of 22 mm for the cottonized flax fibers and of 38 mm for the
lyocell
fibers.
[0084] Example 1.2: Nonwoven substrate prepared by a drylaid process and
comprising 95% by weight of solids of said nonwoven substrate of a mixture of
cottonized flax fibers and of lyocell fibers (90% cottonized flax/10% lyocell
by weight
of solids of the mixture of fibers) and 5% by weight of solids of said
nonwoven
substrate of starch
[0085] The nonwoven substrate is obtained by the process described in example
1.1. After drying, the web was compacted at a pressure of 1 bar. The content
of
binder in the web is 5%.
[0086] The nonwoven substrate obtained has a density of 22 mg/cm3, a thickness
of 1900 m, a grammage of 42 g/m2 and an air permeability of 640 cm3.c1rn2.sec-
1.
[0087] Example 1.3: Nonwoven substrate prepared by a drylaid process and
comprising 88% by weight of solids of said nonwoven substrate of a mixture of
cottonized flax fibers and of lyocell fibers (90% cottonized flax/10% lyocell
by weight
of solids of the mixture of fibers) and 12% by weight of solids of said
nonwoven
substrate of starch
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[0088] The nonwoven substrate is obtained by the process described in example
1.1. The content of binder in the web is 12%.
[0089] The nonwoven substrate obtained has a density of 14 mg/cm3, a thickness
of 2040 pm, a grammage of 29 g/m2 and an air permeability of 890 cm3.cm-2.sec-
1.
[0090] Example 1.4: Nonwoven substrate prepared by a drylaid process and
comprising 95% by weight of solids of said nonwoven substrate of a mixture of
cottonized flax fibers and of lyocell fibers (90% cottonized flax/10% lyocell
by weight
of solids of the mixture of fibers) and 5% by weight of solids of said
nonwoven
substrate of polyvinyl alcohol
[0091] The nonwoven substrate is obtained by the process described in example
1.1. A solution comprising 5% solids content of polyvinyl alcohol (Elvanol 71-
30
manufactured by Kuraray) is sprayed onto both sides of the web. The content of
binder in the web is 5%.
[0092] The nonwoven substrate obtained has a density of 17 mg/cm3, a thickness
of 2500 pm, a grammage of 43 g/m2 and an air permeability of 800 cm3.cm-2.sec-
1.
[0093] Example 1.5: Nonwoven substrate prepared by a drylaid process and
comprising 85% by weight of solids of said nonwoven substrate of lyocell
fibers and
15% by weight of solids of said nonwoven substrate of starch.
[0094] The nonwoven substrate is obtained by the process described in example
1.1. The binder level in the web is 15%.
[0095] The non-woven substrate has a density of 13 mg/cm3, a thickness of
2690 pm, a basis weight of 36 g/m2 and an air permeability of 660 cm3.cm-2.sec-
1.
[0096] Example 1.6: Nonwoven substrate prepared by a drylaid process and
comprising 91% by weight of solids of said nonwoven substrate of cottonized
flax
fibers and lyocell fibers mixture (90% cottonized flax /10% lyocell by weight
of the
fiber mixture) and 9% by weight of solids of said nonwoven substrate of
ethylene-
vinyl acetate.
[0097] The nonwoven substrate is obtained by the process described in example
1.1. A solution comprising 3% of ethylene-vinyl acetate solids (eVinamul Elite
15
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manufactured by Celanese) was sprayed on both sides of the web. The content of
binder in the web is 9%.
[0098] The non-woven substrate has a density of 22 mg/cm3, a thickness of
1600 pm, a basis weight of 38 g/m2 and an air permeability of 712 cm3.cm-2.sec-
1.
5 [0099] Example 1.7: Nonwoven substrate prepared by a drylaid process and
comprising 92% by weight of solids of said nonwoven substrate of cottonized
flax
fibers and lyocell fibers mixture (90% cottonized flax /10% lyocell by weight
of the
fiber mixture) and 8% by weight of solids of said nonwoven substrate of starch
[0100] The nonwoven substrate is obtained by the process described in example
10 1.1. After the drying, the web was calendared with a pressure of 7 bar. The
binder
level in the web is 8%.
[0101] The non-woven web has a density of 44 mg/cm3, a thickness of 900 pm and
a basis weight of 40 g/m2.
[0102] Example 2: Manufacture and characterization of filters for a smoking
15 article
[0103] Filters for a smoking article were manufactured with the substrates of
examples 1.1 to 1.7 by a standard method for manufacturing filters without
passage
through a crimping machine. A nonporous plug wrap paper was used to wrap the
rods of nonwoven filtering material.
[0104] The filters of the invention were compared with the paper filter and
with the
commercial cellulose acetate filter. The paper filter was made using a
standard
method for manufacturing filters by crimping the substrate CF 36 of 36 g/m2
and
100 urn thickness. The filters obtained for each term were cut into 21-mm
sticks.
[0105] The characteristics of the filters are given in table 1 below.
[0106] Example 3: Manufacture and characterization of cigarettes
[0107] Cigarettes were prepared using the filters described in example 2. To
form
the cigarettes, the rods of tobacco were assembled with the filters using
tipping
paper. A commercial ''American blend" tobacco was used to form the rods of
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16
tobacco. The cigarettes were prepared with a pressure difference similar to
that of
the commercial cigarette. The ventilation of the cigarettes was blocked.
[0108] The cigarettes prepared were smoked on a Borgwaldt RM20 smoking
machine in accordance with the standard ISO 3308:2000. The pressure drop (PD
in
table 2) was measured in accordance with the standard ISO 6565:2002. The
nicotine content in the smoke was measured in accordance with the standard ISO
10315:2000. The smoking results are given in table 2 below.
[0109] Table 2 demonstrates that, with an equivalent pressure drop, the
cigarettes
with filters according to the invention and the cigarettes comprising a
commercial
cellulose acetate filter have a nicotine content in the smoke which is of the
same
order of magnitude, whereas the cigarettes comprising a filter made from
crimped
paper have a much lower nicotine content in the smoke.
[0110] This example 3 thus demonstrates that the user experience provided by
the
cigarettes comprising the filters comprising the substrate according to the
invention
is as satisfactory as that provided by cigarettes comprising a commercial
cellulose
acetate filter.
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Lo"
[0111] [Table 1]
Commercial Filter comprising Filter comprising Filter
comprising Filter comprising Filter comprising Filter comprising Filter
comprising Filter made from
cellulose acetate the substrate of the substrate of the substrate of the
substrate of the substrate of the substrate of the substrate of crimped 0F36
filter example 1-1 example 1-2 example 1-
3 example 1-4 example 1-5 example 1-6 example 1-7 paper
r.)
Length of the filters 21
[mm]
Diameter of the filters 7.8
[mm]
VVeight of the filters
139 5 115 1 134 1 155 1 147 1 149 1
154 1 157 5 221 1
[mg]
Density of the filters
138 117 137 159 150 150
150 151 226
[mg/cm
[0112] [Table 2]
Commercial Filter comprising Filter comprising Filter comprising
Filter comprising Filter comprising Filter comprising Filter comprising Filter
made from
cellulose the substrate of the substrate of the substrate of
the substrate of the substrate of the substrate of -he substrate of crimped
0F36
acetate filter example 1-1 example 1-2 example 1-3
example 1-4 example 1-5 example 1-6 example 1-7 paper
Number of cigarettes 30
smoked
PD of the cigarettes
104+1 90 1 93 1 91 1 100 1 107 1
103 1 96 5 100 1
[mmWC]
Nicotine
0.85 0.04 0.85 0.04 0.71 0.05 0.78 0.05 0.78 0.05
0.71 0,04 0.70 0,03 0.71 0,07 0.5 0.19
[mg/cigarette]
