TOBACCO POUCH

POCHETTE A TABAC

English Abstract

The invention relates to a method for pasteurizing tobacco contained in a
pouch.
The method has the steps of: providing a pouch that includes a pocket, the
pocket
having a mouth for providing access to the interior of the pocket and having a
closure extending along the mouth; filling the pocket with tobacco through the
mouth; sealing the pocket such that there is an imperfect seal and
pasteurizing the
tobacco contained in the pocket of the pouch. The invention further relates to
a
pouch that contains tobacco, prepared by the present method.

Claims

6
Claims
1. A method for pasteurizing tobacco contained in a pouch, wherein the
method
comprises the steps of:
providing a pouch comprising a pocket, the pocket having a mouth for
providing access to the interior of the pocket and having a closure extending
along
the mouth;
filling the pocket with tobacco via the mouth;
sealing the pocket such that there is an imperfect seal ; and
pasteurizing the tobacco contained in the pocket of the pouch.
2. The method according to claim 1, wherein the method further comprises
the
preliminary step of forming the pouch from a sheet of material.
3. The method according to claim 1 or 2, wherein the pocket of the pouch
comprises at least one micro-perforation in the pocket of the pouch to allow
for fluid
communication between the interior and exterior of the pocket.
4. The method according to claim 3, wherein the at least one micro-
perforation
has a cross-sectional area of less than 0.01 mm2.
5. The method according to any preceding claim, wherein the closure
comprises a first closure strip.
6. The method according to claim 5, wherein the imperfect seal is formed by
sealing the closure strip such that at least one channel is retained to allow
for fluid
communication between the interior and exterior of the pocket.
7. The method according to any one of the preceding claims, wherein the
sealing is obtained by heat sealing a heat-activatable adhesive or by
ultrasonic
welding of the sheet of material or by pressure sealing a pressure sensitive
adhesive.

7
8. The method according to any one of the preceding claims, wherein the
method further comprises a step of sealing the pouch such that there is a
perfect
seal, after the step of pasteurization of the tobacco.
9. The method according to claim 8, wherein the step of sealing comprises
sealing the channel in the first closure strip or the addition of a second
closure strip,
beside the first closure strip which is subsequently sealed.
10. The method according to claim 8, wherein the step of sealing comprises
closing the at least one microperforation.
11. The method according to any of the preceding claims, wherein the step
of
pasteurisation includes applying microwave radiation to the pouch.
12. A pouch for containing tobacco, obtainable by the method according to
any
one of claims 1 to 11.
13. The pouch according to claim 12, wherein the pouch is made of material
comprising oriented polypropylene (OPP), polyethylene terephthalate (PET),
metallised polyethylene terephthalate (MPET), polyethylene (PE) or any
combination thereof.
14. The pouch according to claim 12 or 13, wherein the pouch material has
an
oxygen transmission rate (OTR) value comprised between 1 and 800
cm3/m2/24h/1atm, preferably between 1 and 400 cm3/m2/24h/1atm.
15. The pouch according to any one of claims 12 to 14, wherein the pouch
material has a water vapour transmission rate (WVTR) value comprised between
0.1 and 4 g/m2/day, preferably between 0 2 and 3.5 g/m2/day.

Description

CA 02901699 2015-08-27
TOBACCO POUCH
This application claims priority based on United Kingdom Application No.
1415253.2
entitled "TOBACCO POUCH" filed August 28, 2014, which is herein incorporated
by
reference.
The present invention relates to a method of pasteurizing tobacco. The
invention
also provides a pouch containing tobacco which has been pasteurized.
Tobacco for roll-your-own or make-your-own smoking items is typically stored
in a
sealed pouch made from a metallised or non-metallised material. An example of
such a pouch comprises a closure strip that seals the tobacco content for
transport
and which can be broken by a user to access the contents when necessary. A
need
exists to increase the shelf-life of the tobacco stored in a pouch. One way of
extending the shelf life is to pasteurize the tobacco by way of heating before
it goes
to the consumer.
One problem arising when pasteurising tobacco contained in a completely sealed
pouch is that the pouch is subject to so-called bulging caused by internal
pressure
during heating, which is undesirable because it causes the pouch to expand in
an
unpredictable way which may lead to its rupture, and also causes difficulties
when
packaging tobacco in pouches.
Therefore, there is a need to provide a method of manufacturing sealed pouches
containing tobacco, which do not suffer from the problem of pouch bulging. Of
course,
it is also desirable for the production of such a pouch to be simple, reliable
and cost-
effective.
In order to solve the problems posed, the present invention provides, in a
first aspect of
the invention, a method for pasteurizing tobacco contained in a pouch, wherein
the
method comprises the steps of: providing a pouch comprising a pocket, the
pocket
having a mouth for providing access to the interior of the pocket and having a
closure extending along the mouth; filling the pocket with tobacco via the
mouth;
sealing the pocket such that there is an imperfect seal; and pasteurizing the
tobacco
contained in the pocket of the pouch.

CA 02901699 2015-08-27
2
In a second aspect, the invention provides a pouch for containing tobacco,
obtainable by the above-mentioned method.
The method according to the present invention can comprise a preliminary step
of
forming the pouch from a sheet of material. The pouch is conventionally formed
from a rectangular sheet of material which is folded over itself and welded
together
at the edges to form a pocket where the tobacco is to be kept. A portion of
the
rectangular sheet extending beyond the mouth of the pocket forms a flap
capable of
folding over the pocket.
Once the pouch has been formed from the sheet of material, the pocket of the
pouch is filled with tobacco via the mouth. After filling of the pouch with
tobacco, the
pocket of the pouch is sealed such that there is an imperfect seal.
The provision of an imperfect seal on sealing means that there is fluid
communication between the interior and exterior of the pocket of the pouch.
For
example, to allow for the exchange of gases between the interior and exterior
of the
pocket of the pouch. This is advantageous when the subsequent pasteurization
step is carried out because it renders the pouch less susceptible to so-called
bulging.
An imperfect seal can be obtained in various ways. One way is to have the
pocket of
the pouch comprise at least one micro-perforation, which allows for fluid
communication between the exterior and interior of the pouch. Alternatively,
at least
one micro-perforation may be pierced in the pocket of the pouch after the step
of
sealing to provide an imperfect seal. Preferably, the at least one micro-
perforation
has a cross-sectional area of less than 0.01 mm2 which would limit ingress
flow of
gases after the pasteurisation step is carried out.
A second alternative is to have the closure comprise a closure strip,
preferably
comprising an adhesive, which is preferably a heat-activated adhesive such
that
when the closure strip is heated, the adhesive is activated thereby providing
a seal.
In this case, the imperfect seal is formed by sealing (preferably, heat
sealing) the
closure strip such that at least one channel is retained to allow for fluid

CA 02901699 2015-08-27
3
communication between the interior and exterior of the pocket. Other ways of
sealing can also be used such as ultrasonic welding of the two sheets of
material or
by applying pressure to pressure sensitive adhesives. The pocket of the pouch
may
also include at least one micro-perforation, as detailed above. In other
words, the
imperfect seal may be a combination of at least one micro-perforation and a
channel
which is retained when sealing the closure strip.
The channel can be from 0.1 mm to 10 mm of the closure strip, preferably from
5
mm to 7 mm.
Preferably, the length of the closure strip is from 65 mm to 145 mm. Most
preferably, the length of the closure strip is from 70 mm to 80 mm, from 110
mm to
120 mm or from 130 mm to 140 mm.
The closure strip comprising the heat activatable glue can be heated using a
metal
heater bar in which, when pressed against the closure strip, activates the
glue. In a
preferred embodiment, the closure strip is not resealable once it has been
opened
by a consumer.
The heater bar comprises a recess such that when pressed against the closure
strip, a portion of the closure strip comprising the heat activatable glue is
not heated.
This portion which is not (or less) heated gives rise to a channel allowing
for fluid
communication between the interior and exterior of the pouch. For example, if
a
channel of 5 mm of the closure strip is required, the recess will be 5 mm in
width. In
an alternative embodiment, the heater bar may comprise more than one recess if
more than one channel is required.
After sealing the pocket of the pouch such that there is an imperfect seal,
the pouch
is subjected to pasteurization and/or sterilisation or more generally to a
step in which
tobacco is cured in such a way so as to significantly reduce or completely
remove
microorganisms.
The pasteurisation step can be carried out as described in patent application
W02013/127528.

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4
Preferably, the heating is carried out for about 30 seconds to about 30
minutes,
more preferably for about 2 minutes and about 7 minutes.
Preferably, during the heating step, the tobacco is heated at a temperature of
about
55 to 120 C, preferably about 60 to about 85 C.
Preferably, the heating is carried out by subjecting the package to a heating
medium, in particular water, steam, air or an inert gas.
Alternatively, the tobacco may be heated by means of microwave radiation which
is
able to quickly heat up the tobacco comprising significant moisture content.
After heating, the pouch may be further transported to a cooling station, in
which a
cooling step is carried out. For the cooling step, ambient or cold air is used
to cool
the product down to ambient temperature or to a temperature below ambient
temperature.
Preferably, after pasteurization of the tobacco in the pocket of the pouch,
the pouch
is sealed such that there is a perfect seal to avoid ingress of any
microorganisms.
Therefore, all throughout storage before the pouch is provided to a consumer,
the
pouch is completely sealed. If the imperfect seal is obtained by way of a
closure
strip, in this further sealing step, either the original, first channel in the
closure strip
is completely sealed so that the channel no longer exists along the strip.
Alternatively another full, second closure strip is formed beside the original
closure
strip which is subsequently sealed. In other words, a second closure strip is
placed
across the mouth region of the pocket, and sealed completely, thereby
providing a
perfect seal. If the imperfect seal is obtained by way of one or more
microperforations, then the microperforations are closed or obstructed (i.e.
sealed),
either by a sealant material or by applying a sticker over the at least one
microperforation.
Alternatively, the channel in the closure strip may not be sealed completely
after
pasteurization, such that a channel allowing for fluid communication between
the
interior and exterior of the pocket is present in a pouch to be used by a
consumer. In

CA 02901699 2015-08-27
this case, the channel should be carefully designed to reduce ingress of gas
from =
the exterior while at the same time be of size that allows gas to come out of
the
pouch to expel gas that is formed by the tobacco during storage.
It has been found that a channel of a length of less than 12.5 % (i.e., of
from 0.01%
5 to 12.5%) of the length of the closure strip, preferably from 1.0 % to
9.0 %, most
preferably from 3.5 % to 7.0 % are suitable. When the closure strip comprises
at
least two (or more) channels, the total channel opening shall be the same or
less
than the above mentioned values.
The pouch may further comprise a flap which extends from the mouth and is
capable of folding over the pocket. When the pouch is closed, the flap is
turned
over against the pocket of the pouch. The flap may be detachably connected
with
an adhesive.
The pouch may be formed from a sheet or film of a thermoplastic material such
as a
polyolefin, e.g. polyethylene. However, the pouch is preferably made of a
metallised
material comprising oriented polypropylene (OPP), polyethylene terephthalate
(PET), metallised, polyethylene terephthalate (MPET), polyethylene (PE) or any
combination thereof. Preferably, the pouch is made of a material comprising
OPP,
MPET and PE or PET, MPET and PE. The advantage associated with using a
metallised material over a non-metallised material is that the tobacco is kept
moist
for longer periods of time.
The pouch material typically has an oxygen transmission rate (OTR) in the
range of
from 1 to 800 cm3/m2/24h/1atm, preferably from 1 to 400 cm3/m2/24h/1atm, most
preferably from 1 to 200 cm3/m2/24h/1atm. OTR values can be calculated
according
to the standard method ASTM D3985. In addition, the pouch material typically
has a
water vapour transmission rate (WVTR) of from 0.1 to 4 g/m2/day, preferably
from
0.2 to 3.5 g/m2/day. VVVTR values can be calculated according to the standard
method ASTM F1249.