Note: Descriptions are shown in the official language in which they were submitted.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 1 -
A DEFORMABLE CONTAINER
The present invention relates to a deformable container, in particular a
deformable
container suitable for dispensing dishwasher machine cleaner in an automatic
dishwasher.
BACKGROUND
It is known that automatic dishwashers require intermittent cleaning to remove
residues, such as limescale, which may have built up in the machine over time.
Typically,
such residues are removed by operating the automatic dishwasher with a
container inside
of it which contains dishwasher machine cleaner. During the operation of the
dishwasher,
the heat generated inside of the dishwasher causes the dishwasher machine
cleaner from
the container to be dispensed into the dishwasher to remove the residues.
After operation
of the dishwasher, the container is removed from the cleaned dishwasher, and
the
container then disposed of.
Dishwasher machine cleaner formulations typically include, but are not limited
to:
water; acidifiers such as citric acid; builders such as HEDP; non-ionic
surfactants; and
hydrotropes such as sodium cumenesulphonate. Further information on dishwasher
machine cleaner formulations is contained within WO 2007/060439, the contents
of which
are herein incorporated by reference.
WO 2009/095638 describes an existing container for use in dispensing
dishwasher
machine cleaner in an automatic dishwasher. The container therein disclosed
has a wax
closure at one end. When the container is placed in the dishwasher with the
wax closure
facing down and the dishwasher then operated, heat generated inside the
dishwasher
causes the wax plug to melt allowing dishwasher cleaner inside the container
to be
dispensed.
The number of components which make up the container from WO 2009/095638
(including the main bottle; the wax seal; and the screw-cap) make this
container difficult
and time-consuming to produce. There is the need, therefore, for an improved
container for
dispensing dishwasher machine cleaner in an automatic dishwasher which is
simpler to
manufacture, and easier to produce.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 2 -
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a
deformable
container, the container defining an interior volume for a fluid, and
comprising an outlet
fluidly connected to the interior volume, and a first seal at the outlet;
wherein a portion of the container, upon being heated to a predetermined
temperature, is caused by the heat to deform to reduce the size of the
interior volume for
causing the fluid from the interior volume to open the first seal and pass out
from the
container via the outlet.
The present invention thus provides a deformable container with few
components,
and which is easy and cheap to manufacture. Since the size of the container is
reduced
during use, this also makes the container easier to dispose of once used.
In its most general form, the deformable container is adaptable for use in any
heated
environment where fluid requires dispensing at a predetermined temperature.
Where the deformable container is intended for use in an automatic dishwasher
or a
washing machine, preferably the predetermined temperature is between 50 C ¨ 75
C, more
preferably 65 C ¨ 75 C.
Preferably, the first seal is operable to open, and the size of the interior
volume is
operable to partially reduce, at a first predetermined temperature; and the
size of the
interior volume is operable to further reduce at a second predetermined
temperature which
is higher than the first predetermined temperature. In such cases, the first
predetermined
temperature may be between 50 C ¨ 55 C, and the second predetermined
temperature
between 65 C ¨ 75 C.
To prevent the container from prematurely leaking any fluid through the
outlet,
preferably the container further comprises a frangible seal at the outlet.
Preferably the
frangible seal is operable to be snapped off or torn off by the user just
prior to the container
being placed in a heated environment.
Preferably, the first seal is linear, rather than curved, to improve the flow
of fluid
through the seal.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 3 -
To further control the escape of fluid from outlet, preferably the container
further
comprises a plurality of corrugated channels which do not substantially reduce
in size when
the container reaches the predetermined temperature. Preferably the plurality
of corrugated
channels are located downstream of the first seal.
The container may comprise a rib which is not substantially deformable when
the
container reaches the predetermined temperature. Preferably, the rib extends
around a
circumference of the interior volume. The rib helps to retain the structure of
the deformable
container at the predetermined temperature, and works with the deformable
portions from
the container to help guide fluid out of the container when it is deformed.
When the container comprises a rib, the container may comprise an interior
volume
comprising substantially no sharp edges in a region that is distal to the
outlet and that is
adjacent the rib. The amount of permissible sharpness in these edges will
depend on the
size of the container. Preferably however, such edges should have a radius of
curvature of
at least 3mm.
Preferably, the container comprises a region proximal to the outlet which
defines a
concave indentation for assisting with the removal of fluid from the container
when the
container reaches the predetermined temperature, wherein the concave
indentation defines
a flow path for the fluid to the outlet which decreases in cross-section
towards the outlet.
In some cases, the interior volume from the container may comprise a plurality
of
smaller volumes which are fluidly isolated from each other prior to the
container reaching
the predetermined temperature. This arrangement allows, for example, two
incompatible
liquids which require separation from each other prior to use, to be kept
separated until the
point when the container is deformed.
Particularly in situations where the deformable container is intended for use
in an
automatic dishwasher or a washing machine, preferably the interior volume is
less than or
equal to 300m1 prior to the container reaching the predetermined temperature.
The size of the interior volume is preferably operable to reduce by between
70% -
90% when the container reaches the predetermined temperature.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 4 -
The reduction in the size of the interior volume may be achieved by a portion
of the
container which expands into the interior volume when the container is at the
predetermined temperature. Preferably however, the reduction in the size of
the interior
volume is achieved by the portion of the container being made of a material
comprising, or
consisting of, a shape-memory material, such as a shape-memory alloy or a
shape-
memory polymer. An example of a suitable shape-memory polymer is PET
(polyethylene
terephthalate).
The first seal may comprise a filleted/chamfered edge which is exposed to the
interior
volume for assisting with the opening of the first seal when the container is
heated to the
predetermined temperature. In this way, when the container is heated to the
predetermined
temperature, any fluid in the interior volume of the container is able to
exert a peeling force
on the filleted/chamfered edge to help peel the first seal open.
As mentioned previously, preferably the container is for application of a
liquid
detergent to the interior of an automatic dishwasher. In such cases, the
liquid detergent is
preferably a dishwasher machine cleaner.
To assist with the mounting of the container when it is used in an automatic
dishwasher, preferably the container comprises an attachment means for
attaching the
container to the interior of an automatic dishwasher. In such cases, and where
the
container additionally comprises a rib, the attachment means is preferably
located on the
rib.
Preferably, the interior volume contains a dishwasher machine cleaner
formulation.
According to a second aspect of the present invention, there is provided a use
of a
deformable container according to the first aspect in an automatic dishwasher.
According to a third aspect of the present invention, there is provided a
method for
dispensing a fluid from a deformable container defining an interior volume
containing the
fluid, and comprising an outlet fluidly connected to the interior volume, and
a first seal at
the outlet, the method comprising the steps of:
placing the container in a heated environment;
heating the container in the heated environment to a predetermined
temperature;
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 5 -
wherein upon the container being heated to the predetermined temperature; a
portion of the container is caused by the heat to deform to reduce the size of
the interior
volume for causing the fluid from the interior volume to open the first seal
and pass out
from the container via the outlet.
In this method, preferably the seal opens, and the size of the interior volume
partially reduces, at a first predetermined temperature; and the size of the
interior volume
further reduces at a second predetermined temperature which is higher than the
first
predetermined temperature. In this case, the first predetermined temperature
may be
between 50 C ¨ 55 C, and the second predetermined temperature may be between
65 C ¨
75 C.
According to a fourth aspect of the present invention, there is provided a
method for
manufacturing a deformable container defining an interior volume for a fluid,
and
comprising an outlet fluidly connected to the interior volume, and a first
seal at the outlet,
the method comprising the steps of:
passing two adjacent sheets of material together through a plurality of
sequential
heated dies such that the heated dies shape the sheets of material into the
shape of the
deformable container.
In this method, preferably the plurality of sequential heated dies comprises a
first
set of heated dies and a second set of heated dies; and preferably the method
comprises
the steps of:
passing the two adjacent sheets of material together through the first set of
dies to
shape the adjacent sheets of material into a partly formed container
comprising the interior
volume;
injecting fluid into the interior volume of the partly formed container; and
passing the partly formed container containing the fluid through the second
set of
dies to shape the partly formed container into the deformable container.
DESCRIPTION OF THE FIGURES
The invention will now be described, by example only, with reference to the
accompanying drawings in which:
Figure 1 shows a perspective view of a container in accordance with the
invention.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 6 -
Figure 2A shows a bottom view of the container of Figure 1;
Figure 2B shows a front side view of the container of Figure 1;
Figure 20 shows a top view of the container of Figure 1; and
Figure 2D shows a side end view of the container of Figure 1.
Figure 3A shows a first stage of operation of the container shown in Figure 1;
Figure 3B shows a second stage of operation of the container shown in Figure
1; and
Figure 30 shows a third stage of operation of the container shown in Figure 1.
Figure 4A shows an image of a container similar to the container shown in
Figure 1;
Figure 4B shows an image of the container of Figure 4A after having been used
in an
automatic dishwasher;
Figure 40 shows an image of the container of Figure 4B after having been used
in an
automatic dishwasher and whilst still inside the tray of an automatic
dishwasher.
Figure 5 shows a table illustrating the effectiveness of various differently
shaped
containers when heated.
Figure 6 shows a cross-section view of a different container in accordance
with the
invention.
Figure 7 shows a front view of a container having a curved weak seal and a
close up
view of the curved weak seal.
Figure 8 shows an image of a weak seal of a container similar to the container
shown
in Figure 7.
Figure 9 shows a side end view of the container and the fluid-actuated seal of
the
container.
DETAILED DESCRIPTION
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 7 -
With reference in particular to Figures 1 and Figures 2A-2D, there is shown a
container 10 for dispensing a fluid. The container is predominately made of a
shaped
memory-polymer, such as PET, and defines an interior volume 15 for holding a
fluid, such
as dishwasher machine cleaner. The interior volume is divided into a first and
second
smaller region 20;25. Each of the two smaller regions is fluidly connected to
a plurality of
parallel corrugated channels 30 located at the top of the container. The
channels 30 act as
an outlet for the fluid to escape from the container as will be described, and
do not reduce
in size when heated.
Prior to use, the top ends of the plurality of channels 30 are covered by a
frangible
seal 35 which is operable, in use, to be snapped off or torn off by the user
along a fault line
40 extending substantially perpendicular to the direction of the corrugated
channels 30.
Located between the bottom end of the plurality of channels 30 and the
interior
volume 15 is a fluid-actuated seal 45. The fluid actuated seal 45 extends
across the entire
width of the parallel corrugated channels 30 and preferably extends in a
linear direction 46
which is substantially perpendicular to the direction of the corrugated
channels 30.
In an example the fluid-actuated seal has a width, defined by the distance
between
the corrugated channels 30 and the interior volume 15, between 1mm and 3mm,
for
example 1.5mm to 2.5mm, for example 1.8mm to 2.2mm. The seal width may be
1.5mm,
1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm and/or 2.6mm. The fluid-actuated seal may
have a
uniform width or the width of the fluid-actuated seal may vary, for example
the fluid-
actuated seal may have an area with a smaller seal width to provide a non-
uniform seal
.. strength.
In the example illustrated in Figures 7 and 8 the fluid-actuated seal 45
comprises a
curved contour. As shown in Figure 8 the weak seal comprises a first curved
contour 47
located between the plurality of channels 30 and the interior volume 15 of the
first smaller
region 20 and a second curved contour 48 located between the plurality of
channels 30 and
the interior volume 15 of the second smaller region 25. The first curved
contour 47 directs
the fluid towards a first apex 47a and the second curved contour 48 directs
the fluid
towards a second apex 48a so that the internal pressure is greater and the
seal starts to
open at this point. In the example illustrated in Figures 7 and 8 the apex of
first and second
curved contours 47;48 comprises a discontinuity in the curvature i.e. the apex
47a;48a
.. defines a single point.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 8 -
In the example illustrated in Figures 7 and 8 the width of the seal is non-
uniform. The
width of the seal is less close to the apex of the curve. The reduction in the
width of the
seal weakens the seal at this point relative to the wider seal. The narrower
weaker seal
requires a lower pressure to open compared to the wider seal. In the example
illustrated
the seal width gradually declines away from the apex of the curve. The width
of the seal
may be 3mm away from the apex and 2mm at the apex of the curved contours
47;48.
The fluid-actuated seal may also have a chamfered edge. As illustrated in
Figure 9
the fluid-actuated seal 45 may have a chamfered edge 51 located adjacent to
the first and
second smaller region 20;25. The chamfered edge gradually increases the seal
pressure
from the outer edge between the interior volume 15 to the centre of the seal
45 and
therefore reduces the initial peeling force so that fluid pressure required to
open the fluid-
actuated seal is reduced.
Each of the first and second smaller region 20;25 comprises a front side wall
50 and
a rear side wall 55 which are deformable when heated to a predetermined
temperature. A
strengthening rib 60, which does not substantially deform when heated to this
predetermined temperature, and which preferably has a greater thickness than
the front
side wall 50 and the rear side wall 55, extends around the side and top
portions of the
interior volume 15 to provide rigidity to the container 10 at the
predetermined temperature.
A partitioning rib 65, having similar properties to the strengthening rib 60,
extends
from the fluid-actuated seal 45 to the bottom of the container 10 to isolate
the first smaller
region 20 from the second smaller region 25.
A fluid port 80 is provided at the top of each the first and second smaller
region 20;25
to allow fluid to be inserted therein during the forming process of the
container 10 as will be
described.
The container 10 is also provided with attachment means, shown in Figure 1 as
hook
shaped portions 71 in the strengthening rib 60, for allowing the container 10
to be attached
in an upright position to an object, although more preferably between the
supports of a
dishwasher tray when the container 10 is located in an inverted position
inside a
dishwasher, as will be described.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 9 -
Operation of the container 10 shown in Figure 1 and Figures 2A-2D is described
with
reference to Figures 3A-30, and also Figures 4A-40.
Initially, a user grips the container and snaps off the frangible seal 35
along the fault
line 40 (see Figure 3B). Although not shown in the Figures, rather than being
snapped off,
the frangible seal 35 may take the form of a tear-off strip which tears along
the fault line 40.
Once the frangible seal 35 is removed, this exposes the plurality of parallel
corrugated
channels 30. The exposed top surface from these channels 30 forms the outlet
70 through
which fluid can escape from the container 10.
Once the outlet 70 is formed, the container 10 is then inverted and placed
between
the supports of a dishwasher tray, as shown in Figure 30, and such that the
hook shaped
portions 71 engage against the bottom of the dishwasher tray (see Figure 40).
In this
inverted position, fluid contained in the first and second smaller region
20;25 is prevented
from passing to the outlet 70 via the corrugated channels 30 by the fluid-
actuated seal 45,
which at this stage remains closed.
The dishwasher is then operated with the container 10 located inside.
As the interior of the dishwasher heats up, the heat generated within the
dishwasher
causes the deformable container to heat up. In the case of a container made of
PET, once
the container reaches a temperature of approximately 50 C ¨ 55 C, the front
side wall 50
and the rear side wall 55 of the container deform slightly inwardly. The
initial deformation of
these side walls 50;55 causes the size of the first and second smaller region
20;25 to
reduce, which increases the pressure of the fluid contained within these
regions 20;25.
The increased pressure of the fluid exerts a pressure on the fluid-actuated
seal 45
which forces it to peel open, allowing an initial portion of the fluid from
the container 10 to
pass through the channels 30 and out the outlet 70 into the dishwasher.
As the interior temperature inside the dishwasher continues to increase
towards the
intended operating temperature of the dishwasher, typically around 65 C ¨ 75
C, the
increase in temperature causes further inward deformation of the front side
wall 50 and the
rear side wall 55 of the container 10 such that the container is deformed into
a flattened
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 1 0 -
state as shown in the images of Figure 4B and Figure 40. In this state, any
fluid in the
interior volume is forced by the flattened side walls 50;55 through the fluid-
actuated seal 45
and out of the outlet 70. In this flattened state shown in Figure 4B and 40,
the interior
volume of the container is around 10%-30% of its original size as shown in
Figure 4A.
It will be seen from Figure 40 that the hook shaped portions 71 in the
strengthening
rib 60, which engage against the bottom of the dishwasher tray, help keep the
container in
its inverted position, even when it is deformed. This is important since fluid
escape from the
container is optimized when the container is in an inverted position as shown
in Figure 40,
rather than in a flat position. The hook shaped portions 71, when engaged
against the
bottom of the dishwasher tray also keep the container straight in use and
prevent it from
folding like a book onto itself when it deforms. Such folding is
disadvantageous since it
reduces the amount of fluid which can escape from the first and second smaller
regions
20;25. The hook shaped portions 71 also prevent the container 10, once emptied
and
deformed, from being displaced inside the dishwasher by the pressurized water
jets
emitted from the rotating spray arm of the dishwasher.
The extent to which fluid is forced out from the first and second smaller
region 20;25
depends on the shape of the first and second smaller region 20;25, and the
extent to which
the front side wall 50 and the rear side wall 55, which are made of a shaped-
memory
polymer, inwardly deform when they are heated to the predetermined
temperature.
To improve the extent to which fluid inside the first and second smaller
region 20;25
is drawn towards the channels 30, the regions of the front side wall 50 and
the rear side
wall 55 which are away from the outlet 70 and which are proximal to the
strengthening rib
60 and the partitioning ribs 65 should comprise no sharp edges, since these
sharp edges
when deformed can create narrow capillaries which retain fluid inside the
first and second
smaller region 20;25, even after these regions 20;25 have deformed. To
minimize such
fluid retention inside the first and second smaller region 20;25, preferably
the regions of the
front side wall 50 and the rear side wall 55 which are proximal to the
strengthening rib 60
and the partitioning ribs 65 comprise a fillet 90.
To further improve the extent to which fluid inside the first and second
smaller region
20;25 is drawn towards the channels 30, each of the front side wall 50 and the
rear side
wall 55 may comprise a concave indentation 75 in a region proximal to the
channels 30 and
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 11 -
the outlet 70 which decreases in cross-section towards the outlet, and which
does not
deform when heated. Figures 4A-40 show this most clearly, where it can be seen
that the
concave indentations 75 have the same shape both before and after the
container 10 has
been heated and deformed in an automatic dishwasher.
Having the fluid-actuated seal 45 formed in a straight line, rather than as a
curve,
also results in improved transfer of fluid from the first and second smaller
region 20;25
through to the channels 30.
To illustrate how the shape of the first and second smaller regions 20;25
affects how
these regions deform and expel fluid when heated, Figure 5 shows various
differently
shaped deformable containers before and after use inside an automatic
dishwasher
operated at 65 C. As can be seen in Figure 5, the pillow shaped container
having the
concave indentations 75 and the fillet 90 is the most effective of the shown
containers at
expelling fluid.
Although the deformable container shown in the Figures has been described as
being
suitable for dispensing dishwasher machine cleaner in an automatic dishwasher,
it will be
appreciated that the container may be modified for use in any situation where
a fluid
requires dispensing in an environment only when the temperature of the
environment
reaches a predetermined level. One such situation includes dispensing
detergent inside a
washing machine.
The choice of shape-memory polymer for the deformable portions of the
container 10
will depend on the intended application for the container 10. When used inside
a
dishwasher, the deformable portions of the container 10 are preferably
predominately
made of a shape-memory polymer which has a glass transition temperature (TG)
in the
region of the operating temperature inside a dishwasher. Accordingly, for use
inside a
dishwasher, the selected shape-memory polymer should have a glass transition
temperature of between 50 C ¨ 75 C. PET is one such suitable shape-memory
polymer.
Once the choice of shape-memory polymer has been made for the container 10,
manufacture of the container 10 is achieved by heating the container above its
glass
transition temperature and then shaping the container in these conditions, for
instance in a
thermoforming process or a stretch blow moulding process, into a stressed
shape.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 12 -
Importantly, the portions of the container that are stressed in the forming
process are the
portions of the container that are intended to be deformed in use of the
container. These
portions include the front side wall 50 and a rear side wall 55; but not the
partitioning rib 65,
the strengthening rib 60, or the concave indentations 75. Once the stressed
shape is
achieved the container 10 is constrained in this stressed shape and
simultaneously cooled
back below its glass transition temperature. Once cooled, the container 10 is
set in the
stressed shape, which is the shape shown in Figure 1 and Figures 2A-2D.
When the container 10 is subsequently heated above its glass transition
temperature
in use, e.g. inside a dishwasher, the container 10 is allowed to revert to a
shape which is
less stressed. This less stressed shape corresponds to the shape of the
container when it
is inwardly deformed.
From the above, it will be appreciated that how the container 10 is
manufactured, and
placed in a stressed shape, affects the extent to which the container inwardly
deforms
when it is heated to the predetermined temperature. It will therefore be
appreciated by the
skilled person that the exact material selected (together with its associated
glass transition
temperature) for the container, and the particular manufacturing conditions
used to shape
the container in its stressed shape, will thus vary depending on the intended
application for
.. the container.
The forming process used to create the container 10 can be performed in a
number
of different ways, as required, to allow for fluid to be inserted into of each
the first and
second smaller region 20;25. In one forming process, the container 10 is
formed by
passing two adjacent sheets of material through a series of sequential heated
dies, wherein
each heated die operates to partly shape the sheets of material into the shape
of the
container 10. In one operation, the adjacent sheets of material are passed
through a first
set of heated dies such that the sheets form the container 10 but without its
fluid ports 80
sealed. From this partly-formed state, the partly-formed container is placed
in an upright
position and fluid is then inserted into each of the first and second smaller
regions 20;25 via
the unsealed fluid ports 80. Once the container is filled, the partly-formed
container is
passed through a further set of heated dies to seal the fluid ports 80 such to
seal the fluid
inside the first and second smaller regions 20;25, and such to create the
container 10.
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 13 -
In relation to the faces of the portions of the heated dies which form the
adjacent
sheets of material into the strengthening rib 60, and any partitioning rib 65,
preferably these
faces are textured, such as corrugated. In this way, when these faces from the
heated dies
contact the portions of material which form the strengthening rib 60 (and any
partitioning rib
65), the die faces deform these portions of material such they share a greater
area of
contact compared with if they were formed using non-textured die faces. This
additional
contact area improves the sealing properties of the strengthening rib 60 and
the partitioning
rib 65.
It will be appreciated that various modifications can be made to the container
herein
described. For instance, it will be appreciated that rather than the interior
volume of the
container being made of two isolated regions 20;25, the interior volume may be
separated
into any number of such regions (including only one) depending on the number
of
partitioning ribs 65 (if any) used.
The size of the container 10 and its interior volume 15 may also vary
depending on
the intended application for the container 10. When being used to hold
dishwasher
machine cleaner, the interior volume may ideally hold no more than 300m1,
preferably no
more than 250m1, and further preferably no more than 200m1, of dishwasher
machine
cleaner.
The dimensions of the container may also vary depending on the intended
application
for the container 10. When being intended for use in an automatic dishwasher,
the
maximum height of the container may be approximately 135mm, the maximum width
of the
container approximately 150mm, and the maximum depth of the container
approximately
35mm.
The reduction in size of the interior volume need not necessarily be achieved
using a
shape-memory material. A similar reduction in size may be achieved using a bag-
in-box
.. type container as shown in Figure 6. In this arrangement, the container 100
may be
provided with a rigid outer housing 102 in which is located a resilient
container 104 defining
an interior volume for a fluid to be dispensed. A fluid-actuated seal 145,
which may be
similar to the fluid-actuated seal 45 described in Figures 1 and Figures 2A-
2D, provides an
outlet for the fluid from the resilient container 104. A heat-transfer fluid
103 (such as air),
CA 03021621 2018-10-19
WO 2017/182652 PCT/EP2017/059552
- 14 -
which expands when heated, is located between the rigid outer housing 102 and
the
resilient container 104.
In operation of the container 100 shown in Figure 6, when the container 100 is
heated
.. to the predetermined temperature, the heat-transfer fluid between the rigid
outer housing
102 and the resilient container 104 expands causing the resilient container
104 to inwardly
deform, which increases the pressure of the fluid inside the resilient
container 104. As the
pressure exerted on this fluid increases, the pressure this fluid exerts on
the fluid-actuated
seal 145 also increases. Ultimately, the pressure on the fluid-actuated seal
45 forces it to
open, allowing fluid out of the container 100.
