Note: Descriptions are shown in the official language in which they were submitted.
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Closed flexible sachet
The invention relates to a closed flexible
sachet in the form of an individual portion provided
for extraction under pressure, containing at least one
~ pulverulent substance for the preparation of a beverage
chosen from ground roast coffee, tea, instant coffee, a
- mixture of instant coffee and ground coffee, a
chocolate-type product or any other dehydrated edible
substance, consisting of two identical flexible sheets
or of a single folded flexible sheet of circular, oval
or polygonal shape, creating a space for the
pulverulent substance between the two sheets or between
the two faces of the folded sheet, and the two sheets
or the two faces of the folded sheet are welded over
their periphery so that the said sachet is
substantially symmetrical with respect to its welding
plane, the material used for the flexible sheets is
impermeable to oxygen and to water vapour in order to
preserve it, and the sachet is opened through the
effect only of the rise in pressure which takes place
upon injection of the extraction fluid.
Patent WO 94/01344 already relates to a closed
flexible sachet provided for extraction under pressure.
With this sachet, at the time of extraction, one of the
flexible sheets is perforated so as to allow the
arrival of the extraction water. The drawback of
perforating the sheet is that firstly it is necessary
to guarantee the seal over the entire periphery of the
sachet and, secondly, if the coffee in the sachet is
not compacted, it is not always guaranteed that the
said sachet will be perforated.
The object of the present invention is to
develop a closed sachet provided for extraction under
pressure, in which it is unnecessary to guarantee the
seal over the entire periphery of the sachet at the
time of extraction and which makes it possible to avoid
perforating one of the two flexible sheets.
The present invention relates to a closed
flexible sachet in the form of an individual portion
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provided for extraction under pressure, according to
the preamble of Claim 1, and in which the two flexible
sheets or the two faces of the folded sheet extend over
one side of the said sachet beyond their welding line
so as to provide, between the said sheets or between
the two faces of the folded sheet, a channel which
allows the arrival of the extraction fluid, the said
channel being substantially perpendicular to the
welding line on which it emerges.
The presence of the channel between the two
flexible sheets or between the two faces of the folded
sheet makes it possible to insert therein a needle or
any other sharp element allowing the extraction water
to be supplied without perforating or tearing one of
the flexible sheets.. It is unnecessary for the needle
or the sharp element to enter into the channel: it is
also possible to envisage the arrival of the extraction
water precisely at the entry of the said channel. In
one or other alternative, the important thing is that,
in the sachet according to the invention, the said
sachet is not opened by inserting the needle or the
sharp element to the extent of breaking the weld which
closes the said sachet, but it is the pressurized water
which initiates and completely opens the said weld of
the sachet in order to allow the extraction liquid to
enter. The water pressure is normally between 1 and 7
bar, i:e., in order to break the weld, a minimum
pressure of water is required which allows the said
weld to be opened up.
The method and the device which are used for
the extraction of sachets according to the invention
may advantageously be of the type which partially forms
the subject of EP Patent Application Nos. 92107548 and
92112364. "Partially" is understood to mean that the
device is used not for the arrival of the water but for
the exit of the coffee. The lower face of the sachet is
opened by localized ruptures after its deformation
against the non-perforating and non-cutting raised and
hollowed-out elements present on the lower face of the
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device through the effect only of the rise in pressure
which takes place upon injection of the extraction
fluid.
The sachet according to the invention may be of
square, rectangular, oval and other shapes. If the
sachet is of rectangular shape, it has a width of
approximately 2 to 15 cm, preferably of the order of 4-
6 cm, and a length of from 6 to 20 cm. Depending on the
size of the sachet, it is possible to envisage the
extraction of a single cup or of several cups, for
example of two cups. Once filled, the sachet has a
thickness, at its centre, which is preferably between 5
and 20 mm. The measured amount of pulverulent substance
contained may vary between 5 and 50 g, according to its
use. The coffee is normally in the sachet in non-
compacted form, which makes the said sachet relatively
soft. It is, however, also possible to package
compacted coffee. The depth of the arrival channel for
the extraction fluid is normally from 3 to 10 mm and
the diameter of this channel is also between 3 and 10
mm. The weld which closes the sachet normally has a
depth of the order of 1 to 3 mm.
In order to accommodate the coffee on the
flexible sheets or the folded flexible sheet, the
sheets are moulded either by means of compression in a
die/piston assembly, or by means of pressurization of
the inner faces by a gas and/or suction of the outer
faces. In both cases, the mould has the desired relief.
The sheets or the folded sheet may be made from
flexible material such as aluminium with a thickness of
from 5 to 40 microns or from plastic such as PET.
Preferably, the sheets will consist of a
' flexible, multi-layer material which is suitable for
welding using customary methods whilst at the same time
' 35 forming sufficient protection for the product against
oxygen and water vapour. The following combination of
materials is recommended:
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- outer layer: PET (normal, woven or non-woven), PE,
PP, PA, PS or paper;
- high-grade barrier central layer; aluminium with a
thickness of between 5 and 20 microns, EVOH, PVDC,
PET or PVA;
- inner layer: plastic, preferably PE or PP or OPP
with welding lacquer. The seal is normally
achieved at a temperature of between 180 and
250°C.
It is possible to envisage the following multi
layer combinations: PET-EVOH-PE or PET-aluminium-PE.
The use of biodegradable or water-soluble material is
also possible as a single layer or in combination with
other material.
The sachet according to the invention is
manufactured in the conventional manner by means of
deformation by moulding or by drawing of the two
flexible sheets or of the folded flexible sheet which
are impermeable to oxygen and to water vapour, by
measuring the amount of pulverulent substance onto one
of the flexible sheets and by welding the two sheets or
the two faces of the folded sheet over their periphery.
The manufacturing operations are carried out under the
protection of a stream of oxygen-free inert gas, for
example under nitrogen or under CO2.
The major advantage of the sachet according to
the invention is that it allows the arrival of the
extraction water via a small opening in the weld
between the two flexible sheets or between the two
faces of the folded sheet. In this context, it is
possible to envisage several solutions. The channel
between the two flexible sheets or between the two
faces of the folded sheet may, in one version, emerge
directly on the welding line and the extraction fluid
then has a single path via which to arrive at the
sachet. By contrast, if it is desired to improve the
distribution of the flow into the bed of coffee,
provision can be made for an arrival channel which is
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subdivided, after the welding line of the two flexible
sheets or of the two faces of the folded sheet, into at
least two channels emerging at different points in the
sachet: for example, in the case of a sachet for a
single cup, two arrival channels are envisaged, and, in
the case of a sachet for two cups, four arrival
channels are envisaged.
In the sachet-extraction device, it is a sharp
element which is engaged into the water-arrival
channel. So as to guarantee satisfactory insertion of
the said sharp element into the channel, provision is
made on each flexible sheet or on each face of the
folded sheet for a break at the location of the said
channel, allowing separation of the said flexible
sheets or of the said faces of the folded sheet at the
moment the extraction device is pricked. In another
embodiment, it is also possible to envisage offsetting
the two faces of the folded sheet at the location of
the channel. As already mentioned above, it is not
obligatory for the sharp element to engage in the
channel.
According to another embodiment of the sachet
according to the invention, a tube, which is either
adhesively bonded, or crimped or laid in position is
placed in the extension of the channel. The advantage
of this tube is that it facilitates the insertion of
the sharp element.
At the moment of extraction of the sachet
according to the invention, it is held in the
extraction cavity and this guarantees satisfactory
performance of the weld of the two flexible sheets.
This performance is not guaranteed only at the location
V
of the arrival channel for the extraction fluid, so
that the pressure of the said fluid breaks the weld at
this point, and only at this point, so as to allow the
extraction water to enter into the sachet through this
channel or the channels.
As already mentioned above, the sachet
according to the invention needs a satisfactory seal
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viz a viz the extraction fluid only at the location of
the arrival channel. The consequence of this is that it
facilitates the design of the extraction machine and
therefore the latter's cost.
The remainder of the description is made with
reference to the drawings, in which:
Fig. 1 is a plan view of a blank for
manufacturing a sachet according to the invention;
Fig. 2 is a plan view of a blank in a second
embodiment;
Fig. 3 is a diagrammatic plan view of the
sachet during extraction;
Fig . 4 is a plan view of the sachet in a third
embodiment;
Fig. 5 is a plan view of the sachet in a fourth
embodiment;
Fig. 6 is a plan view of the sachet in a fifth
embodiment;
Fig. 7 is a plan view of the sachet in a sixth
embodiment; and
Fig. 8 is a plan view of the sachet in a
seventh embodiment.
The blank (1) is a multi-layer flexible sheet
based on aluminium, polyethylene and polypropylene,
having a thickness of the order of 40 microns and which
is foldable along the line (4). This sheet is
thermoformed so as to create in it two cavities (2, 3)
which make it possible to receive the ground roast
coffee (40) therein. The flexible sheet is then folded
along the line (4) and the two faces of the sheet are
welded along the hatched lines (5; 42). This welding
provides a channel (6) between the two faces, allowing
the insertion of the sharp element for sachet
extraction. In the case of Figure 1, there is a channel
(6) emerging directly onto the bed of coffee. At the
moment of use of the sachet, the water arrives via the
said channel and the pressure of this water makes it
possible to break the seal (45). To facilitate the
insertion of the said sharp element, provision is made
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for breaks (7, 8) on the two faces of the flexible
sheet (1), which makes it possible, when the edge is
pinched in the extraction device, satisfactorily to
open up the opening of the channel ( 6 ) . In the case of
- 5 the figure, there is a sachet, for two cups, which has
a width of 4.5 cm and a length of 9 cm in the case of
~ each cavity ( 2 , 3 ) . The border ( 10 ) of the sachet which
goes beyond the weld (42) has a width of from 2 to
4 cm.
In the case of Figure 2, there is a sheet (11)
based on the same composite as for Figure 1, the said
sheet being foldable along the line (12). It includes
cavities (13, 14) for the ground roast coffee (41). The
sheet is then folded over and welded along the hatched
zones (20, 44) and a channel (15) is made in it which
is subdivided into two channels (18, 19), allowing the
water for extraction to arrive at two different points
in the bed of coffee. When the water arrives, it breaks
the weld in the zone (46) and thus allows sachet
extraction. The breaks (16, 17) permit satisfactory
opening of the channel (15) at the moment of
extraction. The border (43) which goes beyond the weld
(44) has a width of from 2 to 4 cm.
Figure 3 shows a sachet (20) of more oval
shape, with its measured amount of coffee (21). The
weld also appears in the form of hatched zones (22).
The welding zone (23) forms the separation between the
channel (24) and the bed of coffee (21). The sharp
element (25) is displaced between its guides (26) from
a set-back position to a position of engagement in the
channel (24). It is from this moment onwards that the
extraction fluid arrives at a pressure of between 1 and
3 bar and breaks the weld (23). The pressure in the
sachet increases and the lower face of the said sachet
presses against raised and hollowed-out elements which
are diagrammatically represented at (27), until the
said face tears at the locations of the said raised and
hollowed-out elements so as to allow the coffee to flow
into the cup placed beneath the extraction device.
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Figure 4, finally, shows a sachet (30) which
has a measured amount of coffee (31) with a weld (32),
the weld (33) farming the separation between the
measured amount of coffee and the channel (31) for the
arrival of the extraction fluid. In this channel,
provision is made for a tube (34), allowing
satisfactory insertion of the sharp element.
Figure 5 shows a sachet (47) obtained from a
folded-over sheet, which gives two faces (56, 57). This
IO sachet is provided for a single cup of coffee with one
measured amount of coffee (49). The weld appears in the
form of hatched zones (50, 51). The welding zone (52)
forms the separation between the channel (53) and the
bed of coffee (49). After the weld (52), the channel
(53 ) is subdivided into two channels ( 54 , 55) , so that
the water satisfactorily moistens the coffee at two
different locations. At the moment of extraction of the
sachet (47), the offset of the two sheets (56, 57)
allows satisfactory opening-up of the channel (53) to
permit satisfactory positioning of the water-arrival
channel on the said channel (53). The extraction fluid
arrives at a pressure of between 1 and 4 bar and breaks
the weld (52). The water then flows into the sachet and
the pressure in the sachet increases, and the lower
face of the said sachet presses against raised and
hollowed-out elements represented diagrammatically at
(58) until the said face tears at the locations of the
said raised and hollowed-out elements so as to allow
the coffee to flow into the cup placed beneath the
extraction device.
Figure 6 shows a sachet (48) which makes it
possible to prepare two cups of coffee with a measured
amount of coffee (69) and a measured amount (70). The
weld appears in the form of hatched zones (61, 62, 63).
The welding zone (72) forms the separation between the
channel (71) and the bed of coffee (69). After the weld
(72), the channel (71) is subdivided into three
channels: the two channels (64, 65) firstly allowing
the extraction water to progress onto the bed of coffee
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(69) and, secondly, a third channel (66) allowing the
water to progress towards the second bed of coffee
(70). This channel (66) is then itself subdivided into
two channels (67, 68). At the moment the sachet is
used, the extraction fluid arrives via the channel (71)
at a pressure of between 1 and 4 bar and breaks the
- weld (72). The pressure in the sachet increases and the
lower face of the said sachet presses against the
raised and hollowed-out elements represented
diagrammatically at (59, 60) until the said face tears
at the locations of the said raised and hollowed-out
elements so as to allow the coffee to flow into the two
cups placed beneath the extraction device.
Figure 7 shows a sachet (73) obtained from a
folded-over sheet giving two faces (74, 75). This
sachet is provided for two cups of coffee with measured
amounts of coffee (99, 100). The weld appears in the
form of hatched zones (76, 77, 78). The welding zone
(81) forms the separation between the channel (86) and
the beds of coffee (99, 100) . After the weld (81) , the
channel (86) subdivides into four channels: two
channels (82, 83) for the bed of coffee (99) and two
channels (84, 85) for the bed of coffee (100) . At the
moment of extraction of the sachet (73), the offset of
the two sheets (74, 75) allows satisfactory opening-up
of the channel (86) to allow satisfactory positioning
of the water-arrival channel on the said channel (86) .
The extraction fluid arrives at a pressure of between 1
and 4 bar and breaks the weld (81). The water then
flows into the sachet and the pressure in the sachet
increases and the lower face of the said sachet presses
against the raised and hollowed-out elements
represented diagrammatically at (79, 80) until the said
face tears at the locations of the said raised and
. 35 hollowed-out elements so as to allow the coffee to flow
inta the two cups placed beneath the extraction device.
Figure 8 shows a sachet (87) which makes it
possible to prepare two cups of coffee with one
measured amount of coffee (101). The weld appears in
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the form of hatched zones (88, 89, 90, 91). The welding
zone (92) forms the separation between the channel (93)
and the bed of coffee (101). After the weld (92), the
channel (93) subdivides into three channels: the first
two (94, 95) lead directly to the bed of coffee (101),
and the third (96) conveys the water towards the bottom
of the sachet. At the bottom of the sachet, it
subdivides again into two channels (97, 98). In this
embodiment, the water arrives at four points on the bed
of coffee, which allows satisfactory moistening of the
said coffee and satisfactory extraction from the
sachet.
It is well understood that the sachet according
to the invention max be manufactured either from two
flexible sheets or from a single folded flexible sheet.
The advantage of this second solution is that it
dispenses with one welding zone and thus reduces the
risks of a defective seal in the sachet according to
the invention.
Explanation of the abbreviations:
PVDC - polyvinylidene chloride
EVOH - copolymer of ethylene and vinyl alcohol
PP - polypropylene
PE - polyethylene
PET - polyester
PA - polyamide
PS - polystyrene
OPP - oriented polypropylene
PVA - polyvinylacetate
