U.S. patent application number 14/237812 was filed with the patent office on 2014-06-19 for capsule formation.
This patent application is currently assigned to British American Tobacco (Investments) Limited. The applicant listed for this patent is Robert Whiffen. Invention is credited to Robert Whiffen.
Application Number | 20140166026 14/237812 |
Document ID | / |
Family ID | 44735708 |
Filed Date | 2014-06-19 |
United States Patent
Application |
20140166026 |
Kind Code |
A1 |
Whiffen; Robert |
June 19, 2014 |
Capsule Formation
Abstract
A capsule forming apparatus comprising a first support in which
a plurality of first outputs configured to output a first capsule
material are located; a second support in which a plurality of
second outputs configured to output a second capsule material are
located; and a second capsule material feed region between the
first and second supports from which the second capsule material
can enter the second outputs. A method of forming capsules is also
described.
Inventors: |
Whiffen; Robert; (London,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Whiffen; Robert |
London |
|
GB |
|
|
Assignee: |
British American Tobacco
(Investments) Limited
London
GB
|
Family ID: |
44735708 |
Appl. No.: |
14/237812 |
Filed: |
July 27, 2012 |
PCT Filed: |
July 27, 2012 |
PCT NO: |
PCT/EP2012/064781 |
371 Date: |
February 7, 2014 |
Current U.S.
Class: |
131/280 |
Current CPC
Class: |
B01J 13/206 20130101;
B01J 13/04 20130101; A23P 10/30 20160801; A24B 15/283 20130101 |
Class at
Publication: |
131/280 |
International
Class: |
A24B 15/28 20060101
A24B015/28 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 10, 2011 |
GB |
GB1113774.2 |
Claims
1. A capsule forming apparatus comprising: a first support in which
a plurality of first outputs configured to output a first capsule
material are located; a second support in which a plurality of
second outputs configured to output a second capsule material are
located; and a second capsule material feed region between the
first and second supports from which the second capsule material
can enter the second outputs.
2. A capsule forming apparatus according to claim 1, wherein the
second capsule material feed region comprises a gap between the
first and second supports.
3. A capsule forming apparatus according to claim 1, wherein each
of the first outputs comprises a first nozzle and each of the
second outputs comprises a second nozzle.
4. A capsule forming apparatus according to claim 1, wherein each
first output extends at least partially into one of the second
outputs to form a pair of outputs.
5. A capsule forming apparatus according to claim 1, wherein the
first support is substantially parallel to the second support.
6. A capsule forming apparatus according to claim 1, wherein the
first support comprises a first substantially elongate member
through which the first outputs extend and the second support
comprises a second substantially elongate member through which the
second outputs extend.
7. A capsule forming apparatus according to claim 1, wherein the
first support comprises an upper plate which connects all of the
first outputs together and the second support comprises a lower
plate which connects all of the second outputs together.
8. A capsule forming apparatus according to claim 1, wherein
boundaries of the shell material feed region are impermeable to the
shell material.
9. A capsule forming apparatus according to claim 8, wherein the
boundaries of the shell material feed region comprise surfaces of
the supports.
10. A capsule forming apparatus according to claim 1, wherein the
apparatus is configured to feed the first capsule material to the
first outputs in a substantially downward, vertical direction and
wherein the apparatus is configured to feed the second capsule
material to the second outputs in a substantially horizontal
direction.
11. A capsule forming apparatus according to claim 1, wherein the
apparatus is configured to feed the first capsule material to the
first outputs in a direction substantially parallel to a principal
output direction of the first outputs and wherein the apparatus is
configured to feed the second capsule material to the second
outputs in a direction substantially perpendicular to a principal
output direction of the second outputs.
12. A capsule forming apparatus according to claim 1, wherein the
first outputs and second outputs form a capsule material output by
the first and second outputs and comprise droplets having an inner
core of the first capsule material and an outer shell layer of the
second capsule material.
13. A capsule forming apparatus according to claim 1, wherein the
first capsule material comprises a capsule core material and the
second capsule material comprises a capsule shell material.
14. A capsule forming apparatus according to claim 1, further
comprising a vibration unit configured to vibrate a plurality of
the first outputs or a plurality of the second outputs or both.
15. A capsule forming apparatus according to claim 12, further
comprising a body of fluid into which the first and second outputs
are configured to output the capsule material, the fluid being
configured to harden the second capsule material.
16. A capsule forming apparatus according to claim 15, comprising a
fluid director configured to cause the capsule materials to follow
a spiral path in the fluid.
17. A capsule forming apparatus according to claim 15, wherein the
apparatus comprises a looped system around which the fluid is
driven to and from the outputs.
18. A capsule forming apparatus according to claim 15, further
comprising a cooling unit configured to cool the fluid to a
temperature sufficiently low to solidify at least one of the
capsule materials.
19. A capsule forming apparatus comprising: a capsule material
output configured to output capsule material into a body of fluid;
and a fluid flow director configured to create a flow of fluid
which causes outputted capsule material to follow a spiral path in
the body of fluid.
20. A capsule forming apparatus according to claim 19, wherein the
fluid is configured to harden the capsule material.
21. A method of forming capsules comprising: supplying a first
capsule material to a plurality of first outputs located in a first
support; supplying a second capsule material to a plurality of
second outputs located in a second support, supplying the second
capsule material via a second capsule material feed region located
between the first and second supports; outputting a droplet
comprising the first capsule material and the second capsule
material from a combination of the first and second outputs.
22. A method according to claim 21, wherein the droplet comprises a
liquid core of the first capsule material surrounded by a liquid
layer of the second capsule material, and the method further
comprises hardening the second capsule material to form a shell
around the liquid core.
23. (canceled)
Description
FIELD
[0001] The invention relates to the formation of capsules.
Particularly, but not exclusively, the invention relates to an
apparatus and method for forming capsules with a core encapsulated
by a shell. The capsules may be for use in the tobacco
industry.
BACKGROUND
[0002] As used herein, the term "smoking article" includes any
tobacco industry product and includes smokeable products such as
cigarettes, cigars and cigarillos whether based on tobacco, tobacco
derivatives, expanded tobacco, reconstituted tobacco or tobacco
substitutes and also heat-not-burn products.
[0003] Capsules can be incorporated into cigarettes and other
smoking articles. For example, one or more breakable flavour
capsules can be positioned inside the filter of a cigarette to
allow a smoker to make a flavour selection before or during
smoking. Generally speaking, the capsules are broken by squeezing
the filter between finger and thumb to cause a flavour substance
which was previously contained within the capsule to be released
into the filter.
[0004] Equipment used to manufacture capsules for the tobacco
industry includes, for example, a dual nozzle through which core
material and shell material are fed simultaneously. The core and
shell materials are supplied from separate containers, which are
exclusively connected to the dual nozzle via separate feeds. A
cooling fluid system, also exclusive to the dual nozzle, is used to
cool a core/shell combination which exits the nozzles.
[0005] The invention provides an improved process and apparatus for
manufacturing capsules.
SUMMARY
[0006] According to the invention, there is provided a capsule
forming apparatus comprising: a first support in which a plurality
of first outputs configured to output a first capsule material are
located; a second support in which a plurality of second outputs
configured to output a second capsule material are located; and a
second capsule material feed region between the first and second
supports from which the second capsule material can enter the
second outputs.
[0007] The second capsule material feed region may comprise a gap
between the first and second supports.
[0008] Each of the first outputs may comprise a first nozzle and
each of the second outputs may comprise a second nozzle.
[0009] Each first output may extend at least partially into one of
the second outputs to form a pair of outputs.
[0010] The first support may be substantially parallel to the
second support.
[0011] The first support may comprise a first substantially
elongate member through which the first outputs extend and the
second support may comprise a second substantially elongate member
through which the second outputs extend.
[0012] The first support may comprise an upper plate which connects
all of the first outputs together and the second support may
comprise a lower plate which connects all of the second outputs
together.
[0013] Boundaries of the shell material feed region may be
impermeable to the shell material.
[0014] Boundaries of the shell material feed region may comprise
surfaces of the supports.
[0015] The apparatus may be configured to feed the first capsule
material to the first outputs in a substantially downward, vertical
direction.
[0016] The apparatus may be configured to feed the second capsule
material to the second outputs in a substantially horizontal
direction.
[0017] The apparatus may be configured to feed the first capsule
material to the first outputs in a direction substantially parallel
to a principal output direction of the first outputs.
[0018] The apparatus may be configured to feed the second capsule
material to the second outputs in a direction substantially
perpendicular to a principal output direction of the second
outputs.
[0019] The capsule materials output by the outputs may comprise
droplets having an inner core of the first capsule material and an
outer shell layer of the second capsule material.
[0020] The first capsule material may comprise a capsule core
material and the second capsule material may comprise a capsule
shell material.
[0021] The apparatus may comprise a vibration unit configured to
vibrate a plurality of the first outputs or a plurality of the
second outputs or both.
[0022] The apparatus may further comprise a body of fluid into
which the outputs are configured to output the capsule materials,
the fluid being configured to harden the second capsule
material.
[0023] The apparatus may comprise a fluid director configured to
cause the capsule materials to follow a spiral path in the
fluid.
[0024] The apparatus may comprise a looped system around which the
fluid is driven to and from the outputs.
[0025] The apparatus may comprise a cooling unit configured to cool
the fluid to a temperature sufficiently low to solidify at least
one of the capsule materials.
[0026] According to the invention, there is provided a capsule
forming apparatus comprising: a capsule material output configured
to output capsule material into a body of fluid; and a fluid flow
director configured to create a flow of fluid which causes
outputted capsule material to follow a spiral path in the body of
fluid.
[0027] The fluid may be configured to harden the capsule
material.
[0028] According to the invention, there may be provided a method
of forming capsules comprising: supplying a first capsule material
to a plurality of first outputs located in a first support;
supplying a second capsule material to a plurality of second
outputs located in a second support, comprising supplying the
second capsule material via a second capsule material feed region
located between the first and second supports; and outputting a
droplet comprising the first capsule material and the second
capsule material from a combination of the first and second
outputs.
[0029] The droplet may comprise a liquid core of the first capsule
material surrounded by a liquid layer of the second capsule
material, and the method may further comprise hardening the second
capsule material to form a shell around the liquid core.
[0030] According to the invention, there may be provided a capsule
formed according to the method defined above.
[0031] For the purposes of example only, embodiments of the
invention will now be described with reference to the accompanying
figures in which:
BRIEF DESCRIPTION OF THE FIGURES
[0032] FIG. 1 is a schematic illustration of an apparatus for
forming tobacco industry capsules in which upper and lower supports
containing upper and lower groups of nozzles are configured to
vibrate;
[0033] FIG. 2 is an illustration of a tobacco industry capsule
comprising an outer shell and an inner, liquid core.
[0034] FIG. 3 is a schematic illustration of a pair of concentric
nozzles for outputting liquid core and shell material;
[0035] FIG. 4 is a flow diagram of a method for forming
capsules;
[0036] FIG. 5 is a schematic illustration of a nozzle apparatus and
a fluid flow system for forming capsules. The nozzles are immersed
in the fluid, which is driven longitudinally past the nozzles;
[0037] FIG. 6 is a schematic illustration of a nozzle apparatus and
a fluid flow system for forming capsules. The nozzles are immersed
in the fluid, which is driven so that capsules follow a spiral path
in the fluid; and
[0038] FIG. 7 is a schematic illustration of a nozzle apparatus and
a fluid flow system for forming capsules. The nozzles are immersed
in the fluid, which is driven so that capsules follow a spiral path
in the fluid. The fluid flows in a looped circuit and is cooled by
a cooling unit.
DETAILED DESCRIPTION
[0039] An apparatus for forming a capsule 1 which is suitable for
incorporating into a cigarette or other smoking article is shown in
FIG. 1.
[0040] The following description generally refers to a capsule 1
having a substantially spherical core 2 and a substantially
spherical shell 3 which encapsulates the core 2. An example of the
capsule 1 is illustrated in FIG. 2. However, as will be explained
below, other shapes of capsule 1 can also be produced. In terms of
size, the core 2 will generally have a diameter in the range of
between approximately 0.5 mm and approximately 5 mm. An example
diameter is 3.3 mm. The shell 3 will generally have a thickness of
between approximately 0.01 mm and approximately 1 mm. An example
thickness is 0.1 mm. It should be understood, however, that the
invention is not limited to forming capsules 1 with cores 2 and
shells 3 within these size ranges. Capsules 1 with cores 2 and/or
shells 3 with sizes which are bigger or smaller than those given
above can also be formed. As will be explained below, the core
material 2 may be volatile and may be formulated to include a
flavour compound such as menthol. One skilled in the art will
appreciate that a variety of different flavours could be formulated
to be included in a suitable core material 2. The flavour contained
in the capsules 1 is released at a required time, for example when
the shell 3 of the capsule 1 is perforated or crushed.
[0041] Referring to FIG. 1, the apparatus 4 for forming capsules 1
comprises a plurality of first capsule material outputs 5. In the
discussion below, the first capsule material outputs 5 are
configured to output capsule core material 2 and can thus be
referred to as core material outputs 5. Each core material output 5
can, for example, comprise a nozzle 5 configured to receive liquid
core material 2 at its entry and output core material 2 at its
exit. The flow of core material 2 through the nozzle 5 to the
nozzle exit can be caused by gravity or can be aided by the action
of a pump. The core material outputs 5 will hereinafter be referred
to as nozzles 5, although other types of output 5 could
alternatively be used.
[0042] The apparatus 4 for forming capsules 1 also comprises a
plurality of second capsule material outputs 6. In a similar manner
to the core material outputs 5, the second capsule material outputs
6 are configured to output capsule shell material 6 and can thus be
referred to as shell material outputs 6. Each shell material output
6 can, for example, comprise a nozzle 6 configured to receive
liquid shell material 3 at its entry and output shell material 3 at
its exit. The flow of shell material 3 through the nozzle 6 to the
nozzle exit can be caused by gravity or can be aided by the action
of a pump. The shell material outputs 6 will hereinafter be
referred to as nozzles 6, although other types of output 6 could
alternatively be used.
[0043] The arrangement and operation of the core and shell material
nozzles 5, 6 will now be described.
[0044] The core material nozzles 5 are supported by a first support
7, which in FIG. 1 is illustrated as comprising a first plate 7
lying in a substantially horizontal plane. In the discussion below
the first support 7 will be referred to in this context, although
other types of support are equally possible. The support 7
interconnects the core material nozzles 5 so that movement or
vibration of the support 7 causes a corresponding movement or
vibration of the nozzles 5. For example, the nozzles 5 and the
support 7 may be formed as a one-piece unit using suitable
techniques such as moulding or casting. Alternatively, the support
7 may comprise apertures into which the nozzles 5 are subsequently
inserted. The nozzles 5 may be fixed in the apertures. Seals may be
provided at the joins between the apertures and the nozzles to
prevent material leakage. Each nozzle 5 comprises a pathway or
aperture through which core material 2 can pass through the support
7 from one side to the other.
[0045] In a similar manner to the core material nozzles 5, the
shell material nozzles 6 are supported by a second support 8. As
with the first support 7, the second support 8 interconnects the
nozzles 6 and retains them in their intended position in the
apparatus 4. In the example of FIG. 1 and the discussion below, the
second support 8 comprises a second plate 8 which lies in a
substantially horizontal plane substantially parallel to the main
plane of the first plate 7 referred to above. Each shell material
nozzle 6 comprises a pathway or aperture through which shell
material can pass through the plate 8 from one side to the other.
As with the first support 7, the second support plate 8 joins the
plurality of shell material nozzles 6 together so that a movement
or vibration of the plate 8 causes a corresponding movement or
vibration in each of the nozzles 6. Furthermore, as with the first
support 7, the shell material nozzles 6 and the second support 8
may be formed as a one-piece unit using suitable techniques such as
moulding or casting. Alternatively, the support 7 may comprise
apertures into which the nozzles 5 are subsequently inserted as
previously described.
[0046] The first and second plates 7, 8 referred to above may be
substantially rigid and can be formed of any suitable material. As
is shown in the figures and will be explained in detail below, the
first support plate 7 and core material nozzles 5 are located
directly above the second support plate 8. The first and second
plates 7, 8 will therefore be respectively referred to below as
upper and lower plates 7, 8. The core material nozzles 5 may extend
at least partially into the shell material nozzles 6 which are
located beneath them. Core material 2 entering the core material
nozzles 5 passes under gravity through the core material nozzles 5
into the shell material nozzles 6 beneath.
[0047] Core material 2 in liquid form may be fed into the entries
of the core material nozzles 5 by any suitable means. For example,
a reservoir 9 of core liquid 2 may be located in the apparatus 4
above the upper support plate 7 so that the core liquid 2 can flow
into the core material nozzles 5 under gravity. The reservoir 9 may
be located directly above the support plate 7 to reduce the
footprint of the apparatus 4. The reservoir 9 may comprise any
suitable container for holding the core liquid 2. For example, in
FIG. 1, the reservoir 9 comprises a manifold 9 from which the core
material 2 is fed towards the core material nozzles 5. Other types
of tank 9 can alternatively be used. Optionally, the entry of each
of the core material nozzles 5 is connected to the reservoir 9 by a
conduit 10, such as a flexible hose, so that liquid core material 2
can flow through the conduits 10 to the core material nozzles 5. To
prevent leakage, each conduit 10 can be sealed to an exit point of
the manifold 9. A common conduit 10 can be used to connect an exit
of the manifold 9 to all core material nozzles 5. Alternatively, a
plurality of conduits 10 can be used to connect a corresponding
plurality of manifold exits to the core material nozzles 5. For
example, one manifold exit and conduit 10 may be provided for each
core material nozzle 5. This is shown in FIG. 1.
[0048] Alternatively, the core material 2 may flow into the core
material nozzles 5 directly from the reservoir 9. For example, the
upper support plate 7 may comprise the floor of the core material
reservoir 9 so that the entrances of the core material nozzles 5
are open to the main body of core material liquid 2 in the
reservoir 9. In these circumstances, the upper support plate 7 may
be movable relative to the walls of the reservoir 9 so that it and
the core material nozzles 5 can be vibrated without having to
vibrate the rest of the reservoir 9. For example, a suitable seal
can be provided at the join between the upper support plate 7 and
the containing walls of the reservoir 9 so that there is no leakage
of the core material 2 at the join.
[0049] The flow of core material 2 between the reservoir 9 and the
core material nozzles 5 may be aided by a pump (not shown) which is
configured to pump the core liquid out of the reservoir 9 into the
nozzles 5. If a pump is included in the apparatus 4, it can be used
to pump the core material 2 into the core material nozzles 5 from a
reservoir location which is above, level with or below the upper
support plate 7. A valve (also not shown) can be used to control
the flow rate of the core material 2 to and/or in the nozzles 5.
The valve can be located, for example, in the conduit 10 or at the
exit of the reservoir 9.
[0050] As shown in FIG. 1, the upper and lower supports 7, 8 are
separated by a shell material feed region 11, which comprises a
volume or void 11 which extends between the substantially parallel
main surfaces of the plates 7, 8. The volume 11 may be defined by
the surfaces of the plates, optionally together with upstanding
walls at the edges of the supports 7, 8. The plates 7, 8 and walls
are preferably impermeable to the shell material 3 so that the
shell material is contained in the feed region 11. The shell
material feed region 11 feeds shell material 3 to the entries of
the shell material nozzles 6. In operation, liquid shell material 3
can flow into the region 11 between the upper and lower supports 7,
8 so that it can enter the shell liquid nozzles 6. For example, a
shell material reservoir 12 may supply liquid shell material 3 into
the region 11. Optionally, one or more pumps can be used to pump
the liquid 3 into the region 11 and/or pressurize the liquid 3 in
the region 11 so as to aid its passage through the shell material
nozzles 6 in the lower plate 8.
[0051] As shown in FIG. 1, the shell material 3 may be fed into the
region 11 in a direction which is substantially perpendicular to
the directions in which the core material 2 is fed to the core
material nozzles 5. For example, as shown in FIG. 1, the core
material 2 can be fed to the core material nozzles 5 in a
substantially downward, vertical direction and the shell material 3
can be fed into the feed region 11 and hence to the shell material
nozzles 6 in a substantially horizontal direction. The feed
direction of the shell material 3 may also be substantially
perpendicular to the direction in which the core and shell material
2, 3 flow through their respective nozzles 5, 6. Apertures in the
walls referred to above may be used to feed the shell material 6
into the feed region 11 in all horizontal directions. The
substantially horizontal feed direction of the shell material 6 can
be approximately parallel to the main plane of the upper and lower
support plates 7, 8.
[0052] Referring to FIG. 3, the core liquid nozzles 5 and shell
liquid nozzles 6 form pairs of nozzles, each comprising a single
core liquid nozzle 5 and a single shell liquid nozzle 6. More
specifically, each core material nozzle 5 extends downwardly from
the upper support plate 7 across the void 11 between the plates 7,
8 and into one of the shell liquid nozzles 6 located in the lower
plate 8 to form the nozzle pair 5, 6. Optionally, as shown in FIG.
3, the core and shell liquid nozzles 5, 6 of each nozzle pair are
concentric with one another. The diameter of the entries and exits
of the core nozzles 5 may be significantly smaller than those of
the shell nozzles 6 so that shell liquid 3 can freely enter and
exit the shell nozzles 6.
[0053] As may be evident from the discussion above, the location of
each of the core material nozzles 5 with respect to other core
material nozzles 5 may be fixed by its position in the upper
support 7. Likewise, the location of each of the shell material
nozzles 6 with respect to other shell material nozzles 6 may be
fixed by its position in the lower support 8. However, the location
of the core material nozzles 5 with respect to the shell material
nozzles 6 may be altered by relative movement of the upper and
lower supports 7, 8. The degree of relative movement may be
relatively small, for example 5 cm or less, but is sufficient for
the groups of core and shell material nozzles 5, 6 to be
independently vibrated. Therefore, each nozzle pair 5, 6 may
comprise independently vibratable core and shell material nozzles
5, 6.
[0054] The upper and lower supports 7, 8 and groups of core and
shell material nozzles 5, 6 can be vibrated by one or more
vibration units 13 during capsule formation. For example, one or
both of the supports 7, 8 may be connected to a vibration unit 13
which is configured to vibrate the support(s) 7, 8 including the
core and shell liquid nozzles 5, 6. The vibration unit 13 may, for
example, comprise a cam 14 which is configured to apply the
vibration to the support 7, 8 as it rotates. The cam 14 can be
connected to the support(s) 7, 8 via a rod 15 which is fixed to a
non-central point on the cam 14 so that the rod 15 pushes and pulls
the support(s) 7, 8 so that the support(s) 7, 8 moves in a lateral,
substantially horizontal plane as the cam 14 rotates. This is shown
schematically in FIG. 1. It will be understood that other types of
vibration unit 13 can alternatively be used to achieve the lateral
vibration in the support 7, 8. Optionally, an individual vibration
unit 13 is provided for each support 7, 8.
[0055] At the exit of the nozzle pairs 5, 6, the core material 2
being outputted from the core material nozzle 5 and the shell
material 3 being outputted from the shell material nozzle 6 combine
to form a combined droplet 16 comprising an inner region of core
liquid 2 surrounded by an outer layer of shell liquid 3. The
formation of the combined droplet 16 is caused by the relative
positions and dimensions of the core and shell material nozzles 5,
6 and is aided when a vibration is applied to the nozzles 5, 6 by
the vibration unit 13 referred to previously.
[0056] Referring to FIG. 4, in a first stage S1 of the capsule 1
formation process, a stream of core material 2 may flow
substantially continuously from the reservoir 9 along the one or
more conduits 10 into the core material nozzles 5. The flow of core
material 2 is shown by arrows in FIG. 1. Likewise, simultaneously
in a second process S2, shell material 3 may flow substantially
continuously from the shell material reservoir 12 into the shell
material feed region 11 and, from there, into the shell material
nozzles 6.
[0057] As referred to above, an example of a pair of core material
and shell material nozzles 5, 6 is shown in FIG. 3. The nozzles 5,
6 are concentric, with the core material nozzle 5 of each pair
partially extending into the shell material nozzle 6. The core
material nozzle 5 may have smaller entry and exit diameters than
the shell material nozzle 6. The entrances of the shell material
nozzles 6 are open to the common shell material feed region 11 so
that liquid shell material 3 enters the shell material nozzles 6
from the feed region 11. The shell material 3 may be under pressure
in the feed region 11 so that it is forced through the shell
material nozzles 6 by a pressure differential between the entries
and exits of the nozzles 6. Additionally or alternatively, the
shell material 3 may move through the shell material nozzles 6
under gravity.
[0058] The entrances of the core material nozzles 5 are open to the
core material reservoir 9, for example either directly or via the
conduit(s) 10 referred to above, so that core material 2 enters the
core material nozzles 5 under gravity. The flow of liquid material
2, 3 through one or both of the sets of the core and shell material
nozzles 5, 6 may optionally be aided by the action of one or more
pumps configured to pump the liquid 2, 3 through the nozzle(s) 5,
6. The one or more pumps (not shown) are configured to provide
extra motive force to aid with discharge of the core and/or shell
material 2, 3 from the nozzle(s) 5, 6. The pump(s) may, therefore,
be of particular help for discharging materials 2, 3 which have a
relatively high viscosity. The extra motive force provided by the
pump(s) may be regulated by opening and/or closing one or more
control valves. For example, the control valves can be selectively
opened or closed to increase or decrease the flow rate of materials
2, 3 into/out of the nozzles 5, 6. The control valves may be of
particular help for materials 2, 3 which have a relatively low
viscosity and for which the flow rate provided by the pump is
undesirably high.
[0059] As referred to above, at the exit of each nozzle pair 5, 6,
the core material 2 being outputted from the core material nozzle 5
and the shell material 3 being outputted from the shell material
nozzle 6 combine to form a combined droplet 16 comprising an inner
region of core liquid 2 surrounded by an outer layer of shell
liquid 3.
[0060] The one or more vibration units 13 can be used to vibrate
the nozzles 5, 6 as the core and shell liquids 2, 3 move through
them. This may be effected by applying a lateral vibration to one
or both of the supports 7, 8 so that the supports 7, 8 move back
and forth in a substantially horizontal direction. Additionally or
alternatively, the vibration unit 13 can be used to vibrate the
conduit(s) 10 through which the core material 2 may flow to the
core material nozzles 5. The vibration caused by the vibration unit
13 aids with breaking up the continuous stream of core and shell
material 2, 3 into the droplets 16 at the nozzle exits. The
frequency at which the vibration unit 13 applies a vibration is
adjustable in response to user controls so that the application of
the vibration can be optimized for the particular core material 2
and/or shell material 3 being used and the desired droplet size.
The supports 7, 8 can be vibrated independently at a different
frequency to each other.
[0061] In a third stage S3 of the process, combined droplets 16
which have exited the pair of nozzles 5, 6 can enter a fluid 17
such as a suitable oil in which the shell material 6 is caused to
solidify. The fluid 17 may be a cooling fluid configured to
solidify the shell material 3 by reducing its temperature, and will
be described below in such context. However, it will be appreciated
that alternative, for example chemical, solidification processes
can take place to solidify the shell material 3 and therefore that
the fluid 17 does not need to be a cooling fluid 17.
[0062] The fluid 17 is preferably immiscible or substantially
immiscible with the shell material 3. It may comprise a suitable
food-grade oil. Alternatives to oils include propylene glycol,
glycerol, or other suitable food-grade material which, if used as a
cooling fluid, remains in the liquid phase at temperatures below
the freezing point of the shell material 3. The central core
material 2 may remain liquid, for example due its freezing
temperature being lower than the temperature of the fluid 17 or
because it does not chemically react to cause hardening.
[0063] Optionally, droplets 16 exiting the nozzle pair 5, 6 can
fall under gravity through a gas such as air into a fluid reservoir
located below the exit of the nozzles 5, 6. Alternatively, as shown
in FIGS. 5 to 7, the exits of the nozzles 5, 6 may be immersed in
the fluid 17 so that droplets 16 enter the fluid 17 directly from
the nozzle pair 5, 6.
[0064] In a fourth stage of the process S4, a flow pattern may be
established in the fluid 17. For example, a re-circulating flow of
fluid 17 may be established so that fluid 17 flows around a looped
system which starts and finishes at the nozzle exits. Other types
of flow pattern are also possible, as discussed further below.
Baffles may be used to aid with directing the fluid 17 around the
loop. Additionally or alternatively, the flow of fluid 17 may be at
least partially directed by the use of other fluid directors such
as angled nozzle jets, pumps and/or paddles which are configured to
eject or direct streams of the fluid 17 into the larger flow, or
main body, of fluid 17 at a higher velocity than the larger flow,
or main body, of fluid 17. The fluid 17 carries the droplets 16
away from the nozzle exits to a collection point. If a flow pattern
is used, one or more flow restrictors may be placed in the path of
the fluid 17 in order to regulate its flow. This is shown in FIGS.
5 and 6.
[0065] If a flow pattern is used, the flow of fluid 17 carries the
capsules 1/droplets 16 to a collector 18, for example a suitably
sized mesh or grating immersed in the stream of fluid 17, which
collects the capsules 1 whilst allowing the fluid 17 to pass
through it. The collector 18 may be angled to allow for the
capsules 1 to roll down a slope into a receptacle 18a, whilst
separating the fluid 17 and allowing it to re-circulate. As
previously described, the fluid 17 may subsequently be driven
around a looped system back to the nozzles 5, 6, from where it
carries more droplets 16/capsules 1 to the collector 18 in the
manner described above. This is discussed in more detail below with
respect to fluid flow patterns, particularly in relation to FIG. 7.
The looped system can optionally incorporate a refrigeration unit
19 which is configured to cool the fluid 17 as it re-circulates
back to the nozzles 5, 6.
[0066] As referred to previously, the combined droplets 16 of core
and shell material 2, 3 exiting the nozzle pairs 5, 6 take on a
substantially spherical shape in the fluid 17. Therefore, as the
outer layer of shell material 3 solidifies in the fluid 17 during a
fifth step S5 of the process, it forms a substantially spherical
shell 3 around the internal core material 2.
[0067] In its simplest form, the flow pattern may comprise a
longitudinal and substantially uniform stream of fluid 17 which
flows past the exit points of the nozzles 5, 6 at a substantially
uniform velocity and carries the droplets 16 to the collector 18
along a relatively short and direct longitudinal path. An example
is shown in FIG. 5.
[0068] A more sophisticated flow pattern comprises driving the
droplets 16 along a spiral path in the fluid 17, so that the
droplets 16 travel to the collector 18 along a relatively long and
indirect path. An example is shown in FIGS. 6 and 7. This may be
achieved by driving the fluid 17 itself in a spiral pattern, at
least in a region between the nozzle exits and collector 18, by one
or more fluid directors such as jets, paddles and/or pumps so as to
cause the droplets 16 to follow a spiral path on their way to the
collector 18. The pipe or shaft 20 along which the droplets 16 are
driven may be shaped so as to aid with the creation and maintenance
of the spiral flow pattern in the fluid 17. By driving the droplets
16 along a spiral path towards the collector 18 rather than the
direct path described above and illustrated in FIG. 5, the droplets
16 spend more time and travel a further distance in the fluid 17
for a given longitudinal distance travelled towards the collector
18 (e.g. for a given length of pipe 20). Therefore, compared to the
direct, longitudinal path referred to above and shown in FIG. 5, an
equivalent hardening, for example cooling, time and distance of
travel for the droplets 16 in the fluid 17 is obtained for a much
shorter longitudinal distance between the nozzle exit and the
collector 18. The number of droplets 16 present per unit volume of
fluid 17 is also increased. As such, the size and, in particular,
the footprint of an apparatus 4 using a spiral flow path can be
much smaller than an apparatus 4 using a more direct flow path
between the nozzle exit and collector 18. A high rate of capsule
production can be attained with a small overall size of apparatus
4.
[0069] Referring to FIG. 7, the plurality of pairs of the nozzles
5, 6 may all be immersed in the same stream of re-circulating fluid
17. Thus, only a single fluid system is required to serve all
nozzles 5, 6. The fluid system is common to all nozzles 5, 6. By
providing a common fluid system and/or common core and shell
material source tanks, the overall size, in particular the
footprint, of the apparatus 4 is reduced compared to apparatuses
which do not use such common fluid and/or supply systems.
[0070] The fluid 17 may be driven in any of the flow patterns
referred to above and re-circulates in a looped cycle to
continuously carry droplets 16 emitted by the nozzles 5, 6 to the
collector 18, hardening the shell material 3 and creating a capsule
1 on the way. A cooling unit 19 such as the refrigeration unit 19
referred to previously may be positioned within the loop so as to
cool the fluid 17 as required during circulation. In FIG. 7, the
fluid 17 is driven along a spiral path between the nozzle exits and
the collector 18 thereby allowing the outer shell layer 3 of the
droplets 16 to be hardened over a relatively short longitudinal
distance between the nozzles 5, 6 and the collector 18. This
configuration of looped system allows a reduction in the height of
the apparatus 4 because the main flow of fluid 17 is in a
horizontal rather than vertical direction.
[0071] Once the shell layer 3 has solidified, the shape of the body
of core material 2 is defined by the shape of the solid shell 3. It
is advantageous for the core material 2 to be in a liquid state for
reasons that will be explained below. The capsules 1 are removed
from the fluid 17 using the collector 18 described above.
[0072] A suitable shell material 3 can be a gelatine solution which
gels to form a solid and frangible material. The shell material 3
is able to irreversibly change state from a liquid solution to a
solid in the fluid 17. This state change can be driven, for
example, by a change in the temperature of the shell material 3 in
the fluid 17 or by a compound present in the fluid 17 which causes
the shell material 3 to solidify. It will be appreciated that there
are a variety of different gelling or encapsulating substances
which could be used as the shell material 3 which, when treated,
form a solid, frangible shell; for example, gelatin, sodium
alginate and guar gum. The shell material 3 can be formulated to
include a compound which will cause the shell material 3 to
solidify once in contact with the fluid 17. For example, the
reaction of calcium ions with sodium alginates may be used. The
calcium ions and sodium alginates may be contained in opposite ones
of the shell material 3 and fluid 17 so that the reaction occurs
upon contact.
[0073] Solidification of the shell material 3 in the fluid 17 forms
a solid coating 3 which wholly encapsulates the core material 2.
The thickness of the shell 3 can be adjusted as required by
increasing or reducing the amount of shell material 3 which is
combined with each quantity of core material 2 at the nozzles 5, 6.
The thickness of the shell 3 may impact the characteristics of the
capsule 1. For example, the thickness of the shell 3 may affect how
frangible the capsule 1 is.
[0074] The capsules 1 formed using the above-described process
comprise a liquid, for example menthol, core 2 encapsulated by a
solid, for example gelatinous, shell 3. The solid structure of the
shell 3 has different physical and chemical properties compared to
the liquid precursor from which it was formed. For example, once
solidified around the cores 2, the solid shell 3 may be thermally
stable in a temperature range of between -15 and 60 degrees
Celsius. The shell 3 will also provide an impermeable barrier to
the core material 2 inside the capsule 1. This prevents the core
material 2 from leaking from the capsule 1, even when it is in a
liquid state. The thickness and structure of the shell 3 is such
that when the capsules 1 are squeezed between finger and thumb with
a relatively modest amount of pressure, the shell coating 3 cracks
or otherwise breaks so that the liquid core material 2 contained
within the shell 3 is released. If the capsule 1 is inserted into a
cellulose acetate filter of a cigarette in an optional sixth step
S6, breaking the capsule causes liquid core material 2 to bleed
into the fibrous filter material and thus add flavour to smoke as
it is drawn through the filter from the tobacco rod.
[0075] The embodiments and alternatives described above can be used
either singly or in combination to achieve the effects of the
invention.
* * * * *