Note: Descriptions are shown in the official language in which they were submitted.
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Method for packaging a beverage powder in a beverage capsule
Field of the Invention
This invention relates generally to a method for packaging a beverage
powder tending to evolve a gas in a beverage capsule. It also relates to a
beverage
capsule so produced. In particular, this invention relates to such capsules as
adapted for coffee beverages.
Background
Coffee beans, before being used to prepare a coffee beverage, must
generally be roasted. This process induces numerous chemical reactions and
physical changes within the coffee beans, which must be accounted for when
packaging the roasted coffee.
The roasting process is what produces the characteristic flavor of coffee
by causing the green coffee beans to expand and to change in color, aroma and
density. The oils and aromatic volatiles contained and/or developed during
roasting
confer the aroma and flavor of the coffee beverage produced therefrom, but are
also prone to degradation when exposed to the oxygen in the surrounding air.
It is
thus important to protect the roasted coffee from the surrounding air, to
maintain
optimal freshness and shelf life. The roasting process also causes the
production
of gases within the coffee beans, primarily carbon dioxide and carbon
monoxide.
These gases are slowly evolved by the coffee subsequent to roasting in a
process
called "degassing." Grinding the roasted coffee beans will accelerate this
process.
Recently, it has been common to base beverage production systems on
the principle of portioned beverages; that is, providing a pre-determined
volume of
a beverage upon demand. This has been typically accomplished by providing a
capsule, which contains a pre-portioned amount of a beverage powder, most
commonly ground coffee. Hot water is then introduced into the capsule to
prepare
the beverage, which is then dispensed into a container for consumption. Before
use, the capsule can be hermetically sealed under vacuum or controlled
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atmosphere such as mentioned in W08602537 to reduce oxidation by the contact
of coffee with air. While this specification refers to a "capsule," it is
understood
those other terms, such as "pod," "cartridge," or "packet" may be employed
instead.
Such capsules may be configured so as to be hermetically sealed up
until use. It is evident that by such hermetical sealing, it is meant that a
gas transfer
is not made possible in any direction between the inside of the capsule and
the
external atmosphere at least for many months. This is desirable, as the
capsule
will prevent the essential oils present in the coffee from degradation caused
by
contact with oxygen in the air. This improves the flavor and shelf life of the
coffee
within such a capsule. It is also evident that due to its hermetical closure,
the
capsule is configured for a single use.
However, as described above, coffee will evolve gas after roasting.
When the ground coffee is packaged in a sealed container, the container will
trap
any gases evolved by the coffee contained within, which in some cases may
cause
the container to rupture under the pressure generated by the evolved gas. The
container must be constructed more robustly, requiring more materials for its
construction and increasing the cost of its fabrication.
To avoid this, the coffee is held aside for a period of time, allowing
substantially all of the gases to be released from the coffee before it is
packaged in
containers. This process is known in the art as "degassing." By degassing the
coffee beforehand, one may avoid the evolution of gas within the sealed
container
and the accompanying accumulation of pressure.
However, the step of degassing beforehand coffee causes a loss of
aromatic compounds. This aroma loss reduces the aroma intensity and modifies
the aromatic profile of the final beverage obtained from the extraction of the
beverage capsule.
The degassing process is generally accomplished by the use of
degassing silos or buffers, within which the coffee is stored while it
degasses. The
silos are generally provided with means for removing the evolved gases, and
may
optionally be provided with means for introducing an inert gas. This inert
gas,
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generally nitrogen, excludes oxygen from the silos and prevents degradation of
the
coffee.
One must store the degassing coffee within these silos for as long as is
necessary to evacuate a sufficient amount of gas. For ground coffee, the
degassing time is usually between 30 and 60 minutes for a partial degassing to
24
hours or more for a full degassing. However during degassing, a large part of
volatiles aromas of the coffee are lost, diminishing the flavor and the aroma
of the
coffee beverage.
Of course, degassing of the coffee cannot be totally eliminated between
the grinding and the sealing of the capsule since the coffee must be
transported
from the grinding area to the filling and sealing areas. This "transport
degassing" is
dependent on the production line capacity.
W02008129350 refers to a machine for packaging capsules in a
vacuum and/or in a controlled atmosphere. After filling with coffee, the
capsules
are partially closed by an hermetic film. Then, a vacuum is formed inside the
capsules and sealed by a thermo-sealing vacuum device. Optionally, an inert
gas
can be inserted in the capsule after drawing a vacuum to fill the headspace of
the
capsule with a controlled atmosphere. This invention does not deal with a
better
preservation of the aroma of the packaged product. In particular, there is no
indication that the degassing of the product is minimized before the capsule
is
hermetically sealed and gas is kept emanating into the cavity.
In US3077409, the invention seeks to eliminate the holding (degassing)
period for coffee before packing it. It so relates to a coffee package with a
self-
venting reclosure can. The coffee is immediately filled into the can, thus
omitting
the conventional holding cycle. The filled can is then closed under vacuum.
The
can comprises a valve means permitting a portion of the gas within the
container to
pass. However, the problem of preserving aroma is not tackled since the
evolving
gas is allowed to escape out of the capsule.
US4069349 refers to a process for vacuum packaging of roasted ground
coffee in pouches. The pouches are partially sealed, with a tortuous unsealed
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passage, and then stored for a predetermined period of time to permit the
gases to
evolve from the pouches and then sealing the pouches to prevent further
gaseous
passage to and from the product. The degassing of the product outside the
pouch
causes the loss of aromatic compounds.
W02011039711 relates to a method and machine for packing infusion
product into capsules; the machine comprising a series of station for
manipulating,
filling, sealing and overwrapping the capsules and all enclosed within a zone
in
controlled atmosphere (using nitrogen, for example) so as to preserve the
chemical
and physical qualities of the product, for example, aroma in the coffee.
However,
there is no reduction of degassing of the product before sealing and
overwrapping
the capsule; no vacuum is drawn in the package before sealing and no degassing
of the product is contemplated in the package to an extent above the
atmospheric
pressure.W02010007633 refers to a machine for packaging products, in
particular
capsules for machines for delivering infusion beverages. A vacuum bell
provides
vacuum around each capsule to be welded. At the same time, vacuum
compensating means take care of inserting gas, in particular nitrogen, inside
each
capsule in such a way to compensate the presence of vacuum. Afterwards, the
welding means take care of welding the aluminium sheet onto the edge of the
respective capsule. Typically, the product must be degassed before closure of
the
capsule to prevent over-pressure due to the presence of the compensating gas.
Such degassing causes the loss of volatile aromatic compounds.
It is accordingly an object of the invention to provide a method for the
packaging of a beverage powder tending to evolve a gas in a capsule, in which
the
flavor and aroma of the beverage powder are better preserved.
According to a first aspect, the invention is directed to a method for
packaging in a capsule a beverage powder tending to evolve a gas, said capsule
comprising a capsule body defining a cavity containing a quantity of beverage
powder, said cavity being hermetically sealed up or respectively, the capsule
being
hermetically sealed up by an over-packaging.
The packaging method comprises the following steps:
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- providing a quantity of said beverage powder evolving a gas within
said cavity of said capsule body;
- applying a vacuum into said cavity of the capsule body or respectively,
into said over-packaging containing the capsule, so that the internal pressure
in the
5 cavity, or respectively, in said over-packaging is below atmospheric
pressure;
- sealing the capsule to hermetically close said cavity, or respectively,
sealing the over-packaging to hermetically close the over-packaging
surrounding
the capsule while maintaining the internal pressure in the cavity, or
respectively, in
said over-packaging below atmospheric pressure; and
- keeping said gas emanating into the hermetically sealed cavity of the
capsule so that the internal pressure in the sealed-up capsule, or
respectively, in
said over-packaging, is above atmospheric pressure.
This is advantageous in that it permits the packaging of a quantity of
beverage powder in a capsule after a limited degassing, a further degassing of
the
coffee instead occurring within the sealed beverage capsule itself or
respectively
within the over-packaging sealing-up the capsule.
According to a principle of the invention, the vacuum created within the
beverage capsule, or respectively within the over-packaging, before the
capsule or
respectively the over-packaging is sealed, compensates for the pressure
generated by the gases evolved from the coffee. The accumulation of evolved
gas
is thus prevented from building to a pressure that might compromise the
integrity of
the capsule or respectively of the over-packaging.
Since the coffee is not significantly degassed before sealed into the
beverage capsule, the volatile aroma and flavor compounds of the beverage
produced therefrom are preserved and maintained in the capsule or
respectively, in
the over-packaging.
In a practical way, when the beverage powder is a ground coffee, the
method comprises a step of grinding coffee beans before the step of sealing,
the
duration of a degassing step between grinding the coffee beans and sealing the
cavity, or respectively, sealing the over-packaging is less than 25 minutes,
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preferably less than 20 minutes, and most preferably comprised between 5 and
15
minutes.
Thus the degassing time is reduced, and in any event, is shorter than
the duration requested in prior packaging method used to encapsulate ground
coffee in a hermetically close capsule.
According to a feature, the pressure reduction below atmospheric
pressure applied into the cavity, or respectively, into the over-packaging, in
the
step of applying a vacuum, is comprised between 100 and 800 mbar, and
preferably between 250 and 700 mbar, most preferably between 300 and 600
mbar.
These values are well adapted to compensate the increase of pressure
in the capsule body due to the gas evolved by the beverage powder after
sealing of
the capsule body.
The atmospheric pressure is the value of the pressure at the location
where the step of applying a vacuum occurs.
After the keeping step, the internal pressure is comprised between 1050
mbar and 1800 mbar, preferably between 1050 and 1600 mbar, most preferably
between 1050 and 1350 mbar.
The internal pressure is stabilized to a value comprised between 1050
mbar and 1800 mbar, preferably between 1050 and 1600 mbar, most preferably
between 1050 and 1350 mbar, about 72 hours after said sealing step.
This internal pressure is acceptable in term of manufacturing a sealed-
up capsule and is compatible with a 12 month shelf-life for the beverage
capsules.
According to a second aspect, the invention concerns a beverage
capsule comprising a capsule body defining a cavity and being adapted to be
hermetically sealed up with a quantity of beverage powder provided within said
cavity, fabricated by the method of packaging as described above.
The beverage capsule so fabricated will embody the advantages of the
method as detailed above.
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According to an advantageous embodiment of the invention, the cavity
is provided with a predetermined quantity of roast and ground coffee.
Preferably, the cavity is provided with a quantity of roast and ground
coffee comprised between 4 and 16 grams, preferably between 5 and 13 grams. At
the equilibrium (after full degassing), the cavity of the capsule has also
preferably a
volume between 8 to 30 ml, preferably 10 to 20 ml, most preferably 12-16 ml.
Brief Description of the Drawings
Other particularities and advantages of the invention will also emerge
from the following description.
In the accompanying drawings, given by way of non-limiting examples:
- Figure 1 is a series of orthogonal section views depicting an
attachment means, a cutting means, a vacuum-application means, and a sealing
means adapted to perform a method of packaging according to an embodiment of
the invention;
- Figure 2 is a series of orthogonal views of attachment apparatuses in
four different configurations;
- Figure 3 is a flowchart depicting an embodiment of the method of
packaging as integrated into a process for the fabrication of beverage
capsules;
and
- Figure 4 is a schematic view of a method for packaging a capsule in
a sealing over-packaging according to an alternative embodiment of the
invention.
Description of the Invention
The following description will be given with reference to the above-
mentioned figures.
Figure 1 is a sequence of section views depicting the sealing of a
beverage capsule according to the invention. Figure 1 depicts the attachment
and
cutting steps in views A through D, and the vacuum application and sealing
steps
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in views E through H. Portions of the apparatus are omitted from each of these
views for purposes of clarity.
View A depicts an attachment means 100 and a cutting means 101
disposed in a first position, prior to the start of an attachment step. The
attachment
means 100 and the cutting means 101 are generally tubular and coaxial about
the
first longitudinal axis 102.
A capsule body 103 is positioned within the base plate 104, which is
provided with a capsule seat 105 in which the capsule body 103 is positioned.
The
base plate 104 is preferably configured to be mobile, facilitating a high rate
of
production of beverage capsules. This mobile configuration may comprise such
means as a conveyor belt system or rotating turret, for example. In the
preferred
embodiment, the capsule body 103 is positioned beneath the attachment means
100 and cutting means 101 so as to be coaxial with them about the first
longitudinal axis 102.
The capsule body 103 defines a cavity 106, in which a predetermined
quantity of roast and ground coffee powder 107 is provided. The capsule body
103
is substantially cup-shaped, and is provided with an open end 108
communicating
with said cavity 106. The capsule body 103 is further provided with a flange
109,
disposed about the circumference of the capsule body 103 at the open end 108.
The capsule body 103 is preferably fabricated from a formable material
such as aluminum, plastic, starch, cardboard, or combination thereof. Where
the
capsule body itself is not gas-impermeable, a gas barrier layer may be
incorporated therein to prevent the entry of oxygen. The gas barrier may
comprise
a coating, film, or layer of a gas-impermeable material such as aluminum,
ethylene
vinyl alcohol, polyamide, oxides of aluminum or silicon, or combinations
thereof.
For example, in one embodiment, the capsule body 103 is formed of
deep-drawn aluminum. In another embodiment, the capsule body 103 is formed of
deep-drawn polypropylene and aluminum. In a third embodiment, the capsule
body 103 is thermoformed from a combination of polypropylene, ethylene vinyl
alcohol, and polyethylene terephthalate.
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In a preferred embodiment, the flange 109 and the capsule seat 105 are
configured so that the capsule body 103 protrudes through the base plate 104,
with
the flange 109 resting directly on the base plate 104 and substantially the
entire
beverage capsule 103 being disposed beneath the base plate 104. In one
alternate configuration, the capsule seat may be configured as a cup, in which
the
capsule body is seated.
A portion of membrane material 110 is disposed between the cutting
means 101 and the base plate 104. Said membrane material 110 is preferably
provided in the form of a continuous sheet or web, which may be fed into the
apparatus by techniques adapted from those known in the art of materials
handling. The membrane material 110 is preferably flexible, permitting
moderate
elastic deformation. The membrane material 110 may have a thickness between
10 and 250 microns, preferably between 30 and 100 microns.
In a preferred embodiment, the membrane material 110 comprises at
least a base layer fabricated of aluminum, polyester (e.g. PET or PLA),
polyolefin(s), polyamide, starch, paper, or any combination thereof. The base
layer
is preferentially formed of a laminate comprising two or more sub-layers of
these
materials. The base layer may comprise a sub-layer which acts as a gas
barrier, if
none of the other sub-layers are of a material which is impermeable to gas.
The
gas barrier sub-layer is fabricated from aluminum, ethylene vinyl alcohol,
polyamide, oxides of aluminum or silicon, or combinations thereof. The
membrane
material 110 preferably also comprises a sealant layer, e.g. polypropylene,
disposed to create a seal with the capsule body 103.
For example, in one embodiment the membrane material 110 is an
aluminum layer between 25 and 40 microns. In another embodiment, the
membrane material 110 comprises a base layer with two sub-layers: an external
sub-layer made of PET and an internal sub-layer made of aluminum. The
aluminum sub-layer serves the function of preventing undesirable transmission
of
light, moisture, and oxygen. In another embodiment, the membrane material 110
comprises three sub-layers: an external sub-layer of PET 5 to 50 microns
thick, a
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middle sub-layer of aluminum 5 to 20 microns thick, and an internal sub-layer
of
cast polypropylene 5 to 50 microns thick.
View B depicts the apparatus in a second position, during a cutting step.
The cutting means 101 is advanced downward along the first longitudinal axis
102
5 into the membrane material 110. In a preferred embodiment, the cutting
means
101 is sharpened along its peripheral edge 111 so as to cut the membrane
material
110 when pressed into it. However, alternate configurations, such as a hot-
knife
apparatus, may be preferable for certain compositions of heat-sensitive
membrane
material. The cutting means 101 is advanced through the membrane material 110,
10 cutting a membrane 112 of the desired size and shape from the membrane
material 110.
View C depicts the apparatus in a third position, during an attachment
step. At the lower end 113 of the attachment means 100 are disposed a
plurality of
faces disposed substantially perpendicular to the longitudinal axis 102, which
are
pressed into the membrane 112. The attachment means 100 is advanced so that
the lower end 113 presses the membrane 112 into the flange 109 over a
plurality of
regions corresponding to the aforementioned faces.
The attachment means 100 is configured to attach the membrane 112 to
the flange 109 over the regions where the faces of the lower end 113 press
said
membrane 112 into the flange 109 of the capsule body 103. In the present
embodiment, the attachment of the membrane 112 to the flange 109 of the
capsule
body 103 is achieved by heat-sealing; though in other embodiments alternate
techniques such as ultrasonic welding may be preferred.
The attachment means 100 is therefore preferably furnished with
appropriate means for attaching the membrane 112 to the flange 109 during the
attachment step. For example, such means may comprise an electrical resistance
heater, hot air jet, or ultrasonic welding horn. This will make the apparatus
more
compact and space-efficient.
Said regions of the flange 109 corresponding to the faces of the lower
end 113 of the attachment means 100 will comprise a portion of the total
surface of
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the flange 109. The cavity 106 of the capsule body 103 thereby remains in
communication with the surrounding atmosphere, via the spaces between the
flange 109 and the membrane 112 where the membrane 112 remains unattached
to the flange 109.
View D depicts the apparatus in a fourth position, after the completion of
the attachment step. The attachment means 100 and cutting means 101 are
withdrawn from the capsule body 103 and membrane 112. The scrap membrane
material 110 may be removed, while the base plate 104 is advanced in direction
114 to both place the current beverage capsule in position for vacuum sealing
and
bring the next beverage capsule into position for the attachment and cutting
steps.
Preferably, the step for cutting the membrane 112 as depicted in View B
and the step for attaching said membrane 112 to the flange 109 as depicted in
View C are performed sequentially but in a continuous movement of descent of
the
cutting and attachment means 101, 100. A slight vacuum is further applied
through
the attachment means to maintain the membrane 112 in coaxial position in axis
102 during the cutting and attachment steps. This is advantageous, in that it
minimizes the time to fabricate a capsule and thus increases the rate at which
capsules are produced.
View E depicts the apparatus in a fifth position, prior to the start of a
sealing step. The vacuum-application means 115 and the sealing means 116 are
preferably tubular and disposed coaxially about the second longitudinal axis
117.
The cutting and attachment means depicted in the previous steps are omitted
here
for clarity; however, the cutting and attachment means are ideally disposed
adjacent or in close proximity to the vacuum-application means 115 and sealing
means 116, making the apparatus more compact and space-efficient.
The base plate 104 is advanced in the direction 114 until the capsule
body 103 and membrane 112 are also coaxial with the vacuum-application means
115 and the sealing means 116 about the second longitudinal axis 117. The
capsule body 103 and membrane 112 are thus positioned in a centered position
directly below the vacuum-application means 115 and sealing means 116.
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View F depicts the apparatus in a sixth position, during a vacuum-
application step. The vacuum-application means 115 have been advanced so as
to create an airtight seal between the mouth 118 of the vacuum-application
means
115 and the flange 109 of the capsule body 103. A vacuum 119 is applied to the
capsule body 103 through the vacuum-application means 115, reducing the
pressure in the cavity 106 of the capsule body 103 below atmospheric pressure.
The gas within the cavity 106 of the capsule body 103 is drawn out through the
plurality of spaces between the flange 109 and the membrane 112, which are
defined by the regions where said membrane 112 remains unattached to said
flange 109. The gas can be air or any inert gas such as nitrogen, CO2 or a
combination thereof. In this way, the cavity 106 of the capsule body 107 is
voided
of gas without also sucking any of the coffee powder 107 from the cavity 106.
In
this way, the aspiration of the coffee powder into the apparatus or its
entrainment
between the flange 109 and membrane 112 is avoided.
The vacuum-application step is preferentially configured so that the
vacuum may be rapidly applied to the capsule body 103 while avoiding sucking
the
coffee powder 107 from the cavity 106. It is known that the rapid application
of a
vacuum to a beverage capsule may cause some of the coffee powder within to be
sucked out, which may result in damage to the apparatus from aspirated coffee
powder. The coffee powder may also become entrained between the sealing
surfaces of the beverage capsule, weakening the seal and diminishing its
aesthetic
properties. The application of vacuum may also cause the sealing means to
move,
further compromising seal integrity.
Here, the attachment of the membrane 112 to the flange 109 of the
capsule body 103 over a plurality of regions will prevents the aspiration and
entrainment of the coffee powder 107 between the flange 109 and the membrane
112, as well as prevent the displacement of the membrane relative to the
capsule
body during the application of the vacuum 119. The integrity of the beverage
capsule seal and the reliability of the sealing apparatus are thus preserved
even
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when the vacuum is applied very rapidly, permitting higher-quality beverage
capsules to be produced at a faster rate.
The vacuum-application step is also preferentially configured to enable
the conditions within the capsule to be monitored as the vacuum 119 is
applied.
Specifically, the vacuum-application means permits the rapid application of
the
vacuum 119 to a single capsule body 103, rather than the slower application of
a
vacuum to a group of capsule bodies in a vacuum chamber. Thus, by use of data
collection and/or control-loop methods known in the art, one may continually
adapt
the parameters of the vacuum-sealing process to optimize the sealing of each
capsule while still maintaining an overall high rate of production.
View G depicts the apparatus in a seventh position, during a sealing
step. The mouth 118 of the vacuum-application means 115 is kept in contact
with
the flange 109 of the capsule body 103, such that the vacuum within the cavity
106
of the capsule body 103 is maintained. The sealing means 116 is advanced into
contact with the membrane 112, pressing into it along the sealing edge 120
disposed at an end of said sealing means 116. The membrane 112 is pressed into
the flange 109 by the sealing means 116, thereby bonding the remaining
unattached regions of the membrane 112 to the surface of the flange 109 and
hermetically sealing the membrane 112 to the capsule body 103. While the
remaining unattached regions of the membrane are bonded, the bond of the
attached regions created during the attachment step may be renewed. The air-
tight
hermetic seal created between the flange 109 and the membrane 112 will thereby
preserve the vacuum in the cavity 106 of the capsule body 103, protecting the
coffee powder 107 from exposure to air and subsequent loss of flavor and
aroma.
View H depicts the sealed beverage capsule after the completion of the
sealing step. The sealing means 116 is withdrawn to allow the bond to
solidify.
Then the vacuum is stopped in the vacuum means exposing the capsule body 103
and membrane 112 to atmospheric pressure and causing the membrane 112 to
take a concave form as depicted. Finally, the vacuum-application means 115 is
withdrawn. The vacuum which was applied to the capsule body 103 in an earlier
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step is preserved therein by the seal between the flange 109 and the membrane
112. The base plate 104 is then moved off in direction 114, removing the
capsule
to be packaged and distributed and bringing the next capsule into position for
vacuum sealing.
Immediately after the completion of the vacuum-sealing step, the
membrane 112 will be deflected inwardly into the capsule body 103, a result of
the
vacuum within the beverage capsule and exposure to the atmospheric pressure.
As a result of chemical processes triggered by the roasting process, the
coffee powder 107 within the beverage capsule degasses, the gases which are
evolved are kept within the cavity 106 of the beverage capsule by the membrane
112, the capsule body 103, and the hermetic seal between the two. This
accumulation of evolved gases will cause the pressure within the beverage
capsule
to increase until equilibrium pressure is reached. At equilibrium, there will
be a
positive pressure within the beverage capsule, i.e. a pressure above the
atmospheric pressure, causing the membrane 112 to be deflected outwardly.
The vacuum which is sealed into the beverage capsule thus partially
offsets the pressure generated by the gases evolved from the coffee powder
107.
The degree to which the vacuum offsets the evolved gases may vary from
embodiment to embodiment, depending on the volume of the beverage capsule,
the mass of coffee provided within, and the type and degree of roast of the
coffee
powder itself. In any case, the vacuum within the beverage capsule compensates
for the degassing at least to the extent that the evolved gas is prevented
from
compromising the structural integrity of the beverage capsule and its hermetic
properties.
In a preferred embodiment, the pressure reduction below atmospheric
pressure is comprised between 100 and 800 mbar, preferably 250 to 700 mbar and
more preferably between 300 and 600 mbar. After the beverage capsule is
sealed,
the gases evolved by the coffee powder during degassing will continue to
accumulate in the cavity 106 of the beverage capsule, causing the internal
pressure of the beverage capsule to rise above atmospheric pressure in
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approximately 5 hours. The internal pressure of the beverage capsule will
preferably reach equilibrium between 1050 and 1800 mbar, preferably between
1050 and 1600 mbar, and most preferably between 1050 and 1350 mbar, in
approximately 72 hours after the sealing of the capsule.
5 Additionally, the method is preferably configured so that all, or
substantially all, of the degassing occurs within the beverage capsule after
it has
been sealed. While the pressure within the beverage capsule will be negative
at
time of sealing, the evolved gases will rapidly increase the pressure within
the
capsules. In a preferred embodiment, the capsule will rise above atmospheric
10 pressure in less than 5 hours and stabilize in approximately 72 hours.
Figure 2 is a series of orthogonal views depicting a series of
configurations for the attachment means. As discussed above, the attachment
means comprises at its bottom end a plurality of faces, which are pressed into
the
membrane to attach it to the flange of the capsule body over a plurality of
regions
15 corresponding to said faces.
Figure 2A depicts an attachment means provided with two faces 200 of
a first kind. The faces 200 of a first kind are separated by two channels 201
of a
first kind. When pressed into a membrane during the attachment step as
described above, the membrane will be attached to a flange of a capsule body
over
the portion of the surface of the flange corresponding to the faces 200 of a
first
kind, while remaining unattached and permitting fluid communication between
the
cavity of the capsule body and the surrounding atmosphere. Upon the
application
of a vacuum, the air in the capsule body will flow out through the unattached
regions between the membrane and flange defined by the channels 201 of a first
kind.
Figure 2B depicts an attachment means provided with four faces 202 of
a second kind, separated by four channels 203 of a second kind. Such an
attachment means will attach a membrane to a flange of a capsule body over a
plurality of regions corresponding to each of the four faces 202 of a second
kind,
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while leaving the regions of the membrane corresponding to the four channels
203
of a second kind unattached.
Figure 2C depicts an attachment means provided with eight faces 204 of
a third kind, separated by eight channels 205 of a third kind. As above, the
faces
204 of a third kind will define the region over which a membrane is attached
to the
flange of a capsule body, and the channels 205 of a third kind defining where
it is
unattached.
Figure 2D depicts an attachment means provided with eight faces 206 of
a fourth kind, separated by eight channels 207 of a fourth kind. Compared to
the
attachment means depicted in Figure 2C, the faces 206 of a fourth kind are
much
smaller than the faces 204 of a third kind, while the channels 207 of a fourth
kind
are much larger than the channels 205 of a third kind. As a result, the
proportion of
the flange of a capsule body to which a membrane will be attached by the
attachment device in Figure 2D is much lower than would be achieved by the
attachment device of Figure 2C, with a corresponding increase in the size of
the
regions of the flange to which the membrane remains unattached.
The attachment devices may in this way be configured to best suit the
particular application in which the attachment device is to be employed. In
the
foregoing embodiments the attachment devices are altered by adjusting their
number and size; however, in other embodiments it may be advantageous to
modify other elements of their form and geometry such as shape, thickness, or
placement about the lower end of the attachment means.
In this way, one may configure the attachment means to reduce the time
required to apply the vacuum to the capsule body while still minimizing the
aspiration and entrainment of the coffee powder or other edible granules
contained
within the capsule body. The sealing of the beverage capsules may thus be
optimized to achieve a maximum output at a minimum cost.
Figure 3 is a flowchart depicting the method of packaging as integrated
into a process for the fabrication of beverage capsules, said operation
comprising a
series of elements. The first step of the operation is Capsule Body Destacking
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300. The empty capsule bodies are generally stored stacked atop each other
when stored before use, and so must be separated before they can be further
processed. In the step for Capsule Body Destacking 300, the capsule bodies are
separated from each other and placed in the proper orientation to continue in
the
process.
Simultaneously, the Coffee Preparation Process 301 furnishes a supply
of coffee powder for packaging within the beverage capsules. In the Coffee
Preparation Process 301, coffee beans are roasted to the desired degree of
roasting and then ground to the desired degree of fineness.
As discussed above, the gases generated within the coffee beans
during roasting are evolved from the coffee. Some degassing will occur between
the roasting of the coffee and the sealing of the beverage capsule. It is
preferable,
however, to configure the process for fabrication of beverage capsules to
minimize
degassing outside of the capsule, so that the degassing essentially occurs
after the
beverage capsule has been sealed. In an embodiment, the duration between the
grinding of the coffee and the sealing of the capsule is less than ten
minutes.
By limiting degassing before sealing, the aroma and flavor in the
capsule are best preserved. After several days, equilibrium is reached between
the
emanated gases and the retained gases in the coffee. This equilibrium depends
on
the ratio of the coffee weight to the total volume in the capsule, the
pressure
reduction applied during the vacuum step and the resistance of the capsule to
the
equilibrium pressure.
Furthermore, since the coffee is not degassed before the sealing
process, the infrastructure required to degas the coffee beforehand is no
longer
necessary. This renders the beverage capsule sealing operation more compact,
economical, and flexible.
During Product Filling & Densifying 302, a portion of the coffee powder
provided by the Coffee Preparation Process 301 is placed within the capsule
body
and densified, so that the coffee is settled within the capsule body and the
amount
of gas therein is so minimized. In an alternate embodiment, the beverage
powder
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may be compacted into a tablet during the Coffee Preparation Process 301 step,
which is then positioned in the capsule body during the step of Product
Filling &
Densifying 302.
Ideally, each element of the operation is linked by a step for Transport
303, where the capsule body is transferred between the devices for carrying
out
each element of the operation. In addition, it is understood that the elements
for
carrying out each of the elements of the process may be located in proximity
to
each other, or even integrated into each other, so that the time required for
transporting the beverage capsule between elements is minimized. The process
is
thereby rendered more space-efficient and economical.
After this is Membrane Attachment and Cutting 305, as depicted in
Views A-D of Figure 1. In this step, the membrane is attached to the flange of
the
capsule body at a plurality of regions of the flange, leaving a plurality of
unsealed
regions on said flange as well. The membrane is also cut to a size which will
cover
the flange and open end of the capsule body.
Following Membrane Attachment & Cutting 305 is Vacuum Application &
Sealing 306, depicted in Figure 1, Views E-H. A vacuum is applied to the
capsule
body, removing the air from within through the plurality of unsealed regions
of the
flange. The membrane is then sealed over the entirety of the surface of the
flange,
preserving the vacuum within the capsule.
In beverage capsules containing roasted, ground coffee as shown here,
it is particularly advantageous that the vacuum within the capsule is a
reduction of
pressure high enough to offset the pressure generated by the gases evolved by
the
coffee as it degasses in the capsule. A normally configured beverage capsule
will
so resist the pressure accumulated within the sealed capsule as a result of
the
evolved gases.
Finally, the capsule is transferred to Distribution 308, where it may be
packaged in a box, sleeve, bag, or the like and distributed for sale.
Figure 4 depicts a method for packaging a capsule 400 containing
beverage powder tending to evolve a gas, in an over-packaging. The method
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comprises providing a quantity of beverage powder capable of evolving a gas
within a cavity 406 of a capsule body 403. The capsule body 403 is
substantially
cup-shaped and is provided with an open end 408 communicating with said cavity
and a bottom end 401. The bottom end may be apertured. For example, a
plurality
of small apertures can be present in the wall of the bottom end 401 to
facilitate
(without need for a puncturing member) the feeding of water and/or discharge
of
beverage during extraction. The apertures are small enough to allow liquid
transfer
but maintain powder in the cavity.
The capsule 400 may further comprise a flange 409 onto which is
sealed a lid such as a flexible membrane 412 (Step II). The membrane material
is
preferably provided in the form of a continuous sheet or web. In an
alternative, the
lid can be a rigid or semi-rigid wall member connected to the flange by
welding,
e.g., heat or ultrasonic welding, and/or press-fitting in the cavity. The lid
may be
formed of a material hermetical to gas and sealed hermetically on the flange.
However, it may also be non-hermetic to gas and liquid. For example, the lid
may
be apertured. A plurality of small apertures can be present in the lid to
facilitate
(without need for a puncturing member) the feeding of water and/or discharge
of
beverage during extraction. The apertures are small enough to allow liquid
transfer
but maintain powder in the cavity.
In this embodiment, the capsule 400 is sealed in an over-packaging 500
(Step III). The over-packaging may be a flexible or rigid package. For
example, it
can be a flow wrap package sealed onto a seam 501. A vacuum is drawn before
and during sealing of the over-packaging in the interior of the over-
packaging.
Since the capsule 400 is permeable to gas, a vacuum is formed in the cavity as
well. A pressure equilibrium is rapidly obtained so that the pressure in the
cavity is
the same as the pressure between the capsule 400 and the over-packaging 500.
As in the previous embodiment, the gases generated within the coffee
beans during roasting are evolved from the coffee. Some degassing will occur
between the roasting and the sealing of the over-packaging. It is preferably,
however, to configure the process for fabrication of the packed beverage
capsule
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to minimize degassing before sealing, so that the degassing essentially occurs
after the beverage capsule has been sealed in the over-packaging (Step IV). As
a
result of the gas emanating in the capsule and traversing the capsule, the
pressure
in the over-packaging becomes above the atmospheric pressure. In this way the
5 flavor of the coffee is most effectively preserved. The over-packaging is
essentially
impermeable to gas so that the evolved gases after sealing is maintained in
the
over-packaging. After several days, equilibrium is reached between the
emanated
gases and the retained gases in the coffee. This equilibrium depends on the
ratio
of the coffee weight to the total volume in the over-packaging, the pressure
10 reduction applied during the vacuum step and the resistance of the over-
packaging
to the equilibrium pressure.
In the context as described in the above description, the hermetical
closure to the gases refers to the ability of the package, that is the capsule
itself or
the over-packaging, to maintain an internal pressure above 1050 mbar for a
period
15 of at least one week.
Of course, the invention is not limited to the embodiments described
above and in the accompanying drawings.
Modifications remain possible,
particularly as to the construction of the various elements or by substitution
of
technical equivalents, without thereby departing from the scope of protection
of the
20 invention.
In particular, it should be understood that the present invention may be
adapted to fabricate beverage capsules for the preparation of various kinds of
alimentary substances, for example broth, cocoa, coffee, infant formula, milk,
tea,
tisane or any combination thereof. It should also be understood that the
edible
granules comprising said alimentary substances may be provided in various
forms
and sizes, such as flakes, grains, granules, pellets, powders, or shreds and
any
combinations thereof.
While the particular embodiment of the preceding
description is directed to a beverage capsule containing a quantity of
roasted,
powdered coffee, it should not be construed as limiting the scope of the
invention
to beverage capsules so configured.
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The exact configuration and operation of the invention as practiced may
thus vary from the foregoing description without departing from the inventive
principle described therein. Accordingly, the scope of this disclosure is
intended to
be exemplary rather than limiting, and the scope of this invention is defined
by any
claims that stem at least in part from it.
