A SACHET HAVING AT LEAST TWO SEALED COMPARTMENTS
The present invention relates to separate packaging of at least two substances, for example substances that are to be mixed extemporaneously, in particular two hair coloring substances such as a dye and a oxidizer.
Numerous two-compartment flasks have been proposed that enable two substances for mixing together extemporaneously to be packaged separately. Nevertheless such flasks are relatively complex and expensive to manufacture.
French patent application FR 2 826 641 discloses a device for simultaneously dispensing at least two substances packaged separately in first and second flexible-walled sachets. That device has first and second means enabling the two sachets to be held stationary relative to each other in a superposed position so that their respective outlet orifices are disposed in the vicinity of each other, and of the second means that are movable relative to the first means in order to exert pressure on both sachets so as to force their contents out through the above-mentioned orifices. Such a device is relatively complicated to implement.
The invention seeks to provide a solution to packaging at least two substances that is relatively simple, inexpensive, and practical to use.
The invention achieves this by means of a sachet having two sealed compartments, having first and second opposite main walls and having a partition separating the inside of the sachet into two compartments.
A dual sachet of the invention enables two substances to be packaged in a manner that is relatively simple, reliable, and inexpensive.
Advantageously, the sachet has first and second foldable side walls situated on respective sides of the partition. These first and second side walls are, for example, situated opposite each other relative to a longitudinal axis of the partition. Such a disposition

makes filling easier. In a variant, the first and second side walls are situated on the same side relative to a longitudinal axis of the partition.
The presence of foldable side walls enables the capacity of the sachet to be increased without increasing the area of its main walls, thereby making the sachet more ergonomic.
In an exemplary embodiment, the first and second foldable side walls are reentrant. In a variant, the first and second foldable side walls project outwardly.
Still in an exemplary embodiment of the invention, for at least a fraction of the length of the sachet:
- the first main wall is connected to a first
longitudinal edge of the partition;
- the second main wall is connected to a second
longitudinal edge of the partition, said second edge
being opposite to the first; and
- the first side wall connects the first main wall
to the second longitudinal edge of the partition, and the
second side wall connects the second main wall to the
first longitudinal edge of the partition.
At least one of the side walls may be folded along a fold line which may be substantially parallel to the longitudinal axis of the partition.
The sachet may include a third foldable side wall disposed on the same side of the partition as the first side wall, each of the first and third side walls being connected firstly to the partition and secondly to the first main wall.
The sachet may include a fourth foldable side wall disposed on the same side of the partition as the second side wall, each of the second and fourth side walls being connected firstly to the partition and secondly to the second main wall.
The first and fourth side walls may be connected to the same longitudinal edge of the partition. The second
and third side walls may be connected to the same longitudinal edge of the partition.
The sachet may be substantially symmetrical in structure about its longitudinal axis.
The sachet may include a dispenser endpiece, which may be formed by assembling together and cutting out the main walls, the partition, and the side walls.
The fold line(s) may extend over at least a fraction of the length of the endpiece.
Thus, the first and second side walls may be folded along fold lines and these fold lines may extend over at least a fraction of the length of the endpiece. In particular, the fold lines may extend over more than half of the length of the endpiece.
The partition may have different materials on its opposite faces, for example a material on one face adapted to withstand prolonged contact with a hair dye, and on its opposite face a material adapted to withstand prolonged contact with a hair oxidizer.
The main walls and the partition may be assembled together by heat sealing.
Similarly, the side walls and the partition may be assembled together by heat sealing.
At least one of the side walls may be made integrally with a main wall.
The two compartments may present capacities that are substantially equal. The capacity of each compartment may, for example, be less than or equal to 40 milliliters (mL) .
At least the first and second main walls may be formed by flexible sheets of composite structure, e.g. comprising a film of metal, e.g. of aluminum, and at least one film of a thermoplastic material.
In another of its aspects, the invention also provides a method of coloring hair in which two substances contained respectively in the two compartments of a sachet as defined above are applied to the hair, the
two substances being mixed together extemporaneously, for example.
In another of its aspects, the invention also provides a method of fabricating a sachet as defined above, in which flexible sheets for forming the two main walls, the partition, and the foldable side walls are superposed, with the sheets that are to form the side walls each being folded along at least one fold line, and in which the sheets as superposed in this way are heat sealed in a configuration corresponding to the sachet that is to be made.
The heat sealing may be performed in such a manner as to leave an opening for filling purposes on the side opposite from a dispenser endpiece. The main walls may be spaced apart prior to filling, and the opening that was used for filling may be heat sealed once the sachet has been filled.
The invention can be better understood on reading the following detailed description of non-limiting embodiments of the invention, and on examining the accompanying drawings, in which:
- Figure 1 is a face view of a sachet made in
accordance with the invention;
- Figure 2 is a diagrammatic and fragmentary view in
cross-section on II-II showing the sachet of Figure 1;
- Figures 3 and 4 are respective diagrammatic views
showing details III and IV of Figure 2;
- Figure 5 is a view analogous to Figure 1 showing a
variant embodiment; and
- Figures 6 to 9 are views analogous to Figure 2
showing other variant embodiments.
In the figures, and in particular in Figures 3 and 4, the various elements are not necessarily shown in compliance with their real proportions, for the sake of clarity in the drawing.
The dual sachet 1 shown in Figures 1 and 2 is generally elongate in shape along a longitudinal axis X,
having a body 12 that is extended at one end by a dispenser endpiece 2 that can be cut off in use along a line C, for example, in order to enable the user to empty the content from the sachet.
In the example shown, the body 12 is of
substantially constant width, but it could be otherwise without thereby going beyond the ambit of the present invention. For example, the body 12 could present a shape that is trapezoidal or oval.
The sachet defines a first compartment 3 and a second compartment 4 that are for containing respective first and second substances P: and P2 that are to be stored separately, and that are to be mixed together extemporaneously, for example.
One of them may be constituted by a dye and the other by an oxidizer for coloring hair.
The sachet may be given a variety of shapes and may have a variety of capacities, for example the capacity of the sachet may lie in the range 1 mL per 40 mL per compartment, or even in the range 1 mL to 80 mL or even more, e.g. as much as 1 liter (L).
Where appropriate, the dual sachet may serve to test coloring on a lock of hair, in which case each compartment presents a capacity of 1 mL, for example.
The sachet 1 has first and second main walls 5 and 6, first and second foldable side walls 7 and 8, and an internal partition subdividing the inside of the sachet 1 into compartments 3 and 4.
The partition 9 presents first and second longitudinal edges 10 and 11 situated opposite each other, and first and second faces 28 and 29 situated respectively beside the first and second compartments 3 and 4.
The first main wall 5 presents a first longitudinal edge 13 which is assembled in Figure 2 to the first longitudinal edge 10 of the partition 9 on the same side as the face 28, and a second longitudinal edge 15 which
is assembled to the first edge 17 of the first side wall 1, the edge 18 opposite thereto likewise being assembled to the second longitudinal edge 11 of the partition 9 on the same side as the face 28.
Still in the example of Figure 2, the second main wall 6 has a first longitudinal edge 20 which is assembled to an edge 21 of the second side wall 8, the edge 22 opposite therefrom being connected to the first longitudinal edge 10 of the partition 9 on the same side as its face 29, and the second main wall 6 has a second longitudinal edge 23 which is likewise assembled to the second longitudinal•edge 11 of the partition 9, on the same side as the face 29.
Each side wall 7 or 8 is folded along a fold line 24 that is substantially parallel to the longitudinal axis X in the example described, and that may be situated at substantially equal distances from the edges 17 and 18, or 21 and 22.
In the example described, the sachet 1 presents a structure that is generally symmetrical relative to the axis X, at least over a fraction of its length, as can be seen in Figure 2. This need not necessarily be the case, and it is possible, for example, for the side walls 7 and 8 to be unequal, e.g. as a function of different respective capacities for the compartments 3 and 4.
When the sachet 1 is empty, the main walls 5 and 6 are pressed against the partition 9, and the side walls 7 and 8 are folded in half. When the sachet is full, the side walls 7 and 8 are deployed like a bellows.
To make the main walls 5 and 6, the side walls 7 and 8, and the partition 9, it is possible to use flexible sheets, each presenting a multilayer structure, as a function in particular of the nature of the substances to be contained inside the sachet.
By way of example, the sheets used may comprise a film of polyethylene, of polyamide, an appropriate varnish, a layer of aluminum, and superpositions of
various materials, e.g. presenting a composite structure including a layer of adhesive between a polyethylene film and a layer of aluminum.
The sheets used for making the various walls and the partition are preferably selected so as to enable them to be assembled together by heat sealing, i.e. by localized application of heat.
By way of example, it is possible to use sheets presenting physico-chemical properties that are different when constituting firstly the first main wall 5 and the first side wall 7, and secondly the second main wall 6 and the second side wall 8.
Similarly, the partition 9 may present different materials on its opposite faces 28 and 29.
By way of example, the partition 9 may be constituted by a sheet comprising two films that have been laminated together, constituted by materials that are respectively suitable for coming into contact with the substances contained in each of the compartments 3 and 4.
The partition 9 may also present the composite structure shown in Figure 3, comprising an intermediate support film 34 coated on each of its faces with films 31 and 32 that are adapted to packaging the substances 3 and 4.
Each main wall 5 or 6 or side wall 7 or 8 may present the composite structure shown in Figure 4, comprising an outer film 33 and an inner film 34 of a material that is suitable for coming into contact with the substance contained in the associated compartment.
The outer film 33, like the intermediate film 30 of the partition 9, may be constituted, for example, by a layer of aluminum, and one of the covering films 31, 32, or 34 may be of a thermoplastic material.
In order to fabricate the sachet 1, it is possible, for example, to start from five sheet elements packaged on respective reels, that are then superposed, the sheets
that are to form the side walls 7 and 8 being delivered in the folded state to the heat sealing station.
The endpiece 2 is situated between the fold lines 24 when the sachet is empty and flat. The main walls 5 and 6 are assembled respectively to the faces 28 and 29 of the partition 9 around the periphery 43 of the endpiece 2.
The sachet is also heat sealed to the periphery 40 of the body 12 with the exception of a zone 41 situated on the edge opposite from the endpiece 2, between the fold lines 24 and at a distance therefrom, said zone 41 being outlined in dashed lines in Figure 1.
On reaching the filler station, the main walls 5 and 6 may be spread apart from each other, e.g. by means of suction cups, and feed pipes can be inserted into the compartments 3 and 4 in order to fill them.
After filling, the zone 41 can be closed by heat sealing so as to package the two substances P^ and P2 in sealed manner in the compartments 3 and 4 *
In use, the user can cut off the endpiece 2 so as to release the two dispenser orifices opening out respectively into the compartments 3 and 4 and separated by the partition 9.
In order to dispense the content of the sachet, the user can press on the main walls 5 and 6 so as to move them towards each other. The substances P: and P2 contained in the compartments 3 and 4 can be mixed directly on the hair, or in a variant they can be mixed in an auxiliary receptacle, prior to being applied to the hair.
Naturally, the invention is not limited to the embodiment described above.
In the variant embodiment shown in Figure 5, the fold lines 24 are close enough to the longitudinal axis X to extend over a fraction of the length of the endpiece 2, e.g. over more than half of its length, as shown.
Thus, when the endpiece 2 is cut along line C, the dispenser orifice can enlarge by the side walls 7 and 8 deploying, thereby reducing head loss and making it easier for the substances P1 and P2 to flow out.
Figure 6 shows the possibility of making the main walls 5 and 6 respectively integrally with the side walls 7 and 8.
Figure 7 shows the possibility of having side walls 7 and 8 that connect to the same longitudinal edge 11 of the partition 9. The second main wall 6 is thus connected via its edge 20 to the longitudinal edge 10 of the partition 9 and via its edge 23 to the edge 21 of the foldable side wall 8, the edge 22 of the side wall 8 being connected to the longitudinal edge 11 of the partition 9.
Figure 8 shows the possibility of the sachet having more than two foldable side walls, for example four foldable side walls disposed in pairs on either side of the partition 9, thus forming compartments 3 and 4 each constituting a bellows.
The first main wall 5 is connected in the example described to a third foldable side wall 50 via its edge 13. The third foldable side wall 50 has an edge 51 that is connected to the first main wall 5 and an opposite edge 52 that is connected to the longitudinal edge 10 of the partition 9. The second main wall 6 is connected via its edge 23 to the edge 54 of a fourth foldable side wall 55, which is in turn connected to the longitudinal edge 11 of the partition 9 via its own edge 56 opposite to the edge 54.
In the example shown, the sachet 1 is generally symmetrical in structure about the longitudinal axis X, but that need not be so, and in particular the first and third side walls 7 and 50 could present dimensions that are different from the second and fourth side walls 8 and 55, particularly if the compartments 3 and 4 are to have different capacities.
Figure 9 shows the possibility of the foldable side walls 7 and 8 presenting shapes that project outwards rather than inwards.
The characteristics of the various embodiments can be combined.
For example, in the example of Figure 7, the main wall 5 and the side wall 7 can be made as a single piece, as can the main wall 6 and the side wall 8. The same can apply to the examples of Figures 8 and 9.
In the example of Figure 7, the side walls may project outwards rather than inwards. The same can apply to the example of Figure 8.
Where appropriate, the partition 9 may be made up of two sheets placed side by side, at least in part, in particular along their edges.
The sachets may be packaged in various ways, for example as a string or individually. When the package has a string, the sachets can be assembled to one another either sideways or lengthwise. When they are assembled together lengthwise, the bottom of one sachet should have the shape corresponding to the endpiece of the following sachet.
Throughout the description, including in the claims, the term "comprising a" should be understood as being synonymous with "comprising at least one", unless specified to the contrary.

WE CLAIM :
1. A sachet having at least two sealed compartments (3, 4)
and comprising :
first and second opposite main walls (5, 6) and a partition (9) separating the inside of the sachet into the two compartments, said partition having two opposite faces each facing one of the two compartments, characterized in that first and second foldable side walls (7, 8) are fastened to respective opposite faces of the partition (9), the first foldable side wall (7) being fastened to the first main wall (5) and the second foldable side wall (8) being fastened to the second main wall (6).
2. A sachet as claimed in claim , wherein the first (7) and
second (8) foldable side walls are reentrant.
3. A sachet as claimed in claim 1, wherein the first (7) and
second (8) foldable sidewalls project outwards.
4. A sachet as claimed in claim 1, wherein the first (7) and
second (8) side walls are situated substantially opposite
each other about a longitudinal axis of the partition.
5. A sachet as claimed in claim 1, wherein the first (7) and
second (8) side walls are both situated on a common side
relative to a plane containing the longitudinal axis of
the partition.
6. A sachet as claimed in claim 4, wherein, for at least a
fraction of the length of the sachet :
the first main wall (5) is connected to a first
longitudinal edge (10) of the partition (9) ;
the second main wall (6) is connected to a second
longitudinal edge (11) of the partition, said second
edge being opposite the first edge ; and
the first side wall (7) connects the first main wall
to the second longitudinal edge of the partition and
the second side wall (8) connects the second main
wall to the first longitudinal edge of the
partition.
7. A sachet as claimed in claim 1, wherein at least one of
the side walls (1, 8) is folded along a fold line.
8. A sachet as claimed in claim 7, wherein the fold line
(24) is substantially parallel to a longitudinal axis (X)
of the partitition.
9. A sachet as claimed in claim 1, the sachet being
symmetrical in structure about its longitudinal axis (X).
10. A sachet as claimed in claim 1, including a dispenser
endpiece (2) comprising two dispenser orifices opening
A
respectively into the compartments and separated by the partition.
11. A sachet as claimed in claim 7, including a dispenser
endpiece, and wherein the fold line (24) extends over at
least a fraction of the length of the endpiece.
12. A sachet as claimed in claim 11, wherein the first and
second side walls are folded along fold lines (24), and
wherein said fold lines extend over at least a fraction
of the length of the endpiece.
13. A sachet as claimed in claim 12, wherein the fold lines
extend over more than half the length of the endpiece
(2).
14. A sachet as claimed in claim 1, wherein the partition (9)
comprises different materials on its opposite face.
15. A sachet as claimed in claim 1, wherein the main walls
(5, 6) and the partition are assembled together by heat sealing.
16. A sachet as claimed in claim 1, wherein the two
compartments (3, 4) present capacities that are
substantially equal.
17. A sachet as claimed in claim 1, wherein the capacity of
each compartment is less than or equal to 40 mL.
18. A sachet as claimed in claim 1, wherein the first (5) and
second (6) main walls are formed at least by flexible
sheets of composite structure.
19. A sachet as claimed in claim 1, including a third
foldable side wall (50) disposed on the same side of the
partition (9) as the first side wall (7), the first and
third side walls each being connected firstly to the
partition and secondly to the first main wall.
20. A sachet as claimed in claim 19, including a fourth
foldable side wall (55) disposed on the same side as the
partition (9) as the second side wall (8), the second and
fourth side walls being each connected firstly to the
partition and secondly to the second main wall.
21. A sachet as claimed in claim 20, wherein the first (7)
and fourth (55) side walls are connected to a common
longitudinal side (11) of the partition (9).
22. A sachet as claimed in claim 19, wherein the second (8)
and third (50) side walls are connected to a common
longitudinal side (10) of the partition (9).
23. The use of a sachet for coloring hair, in which two
substances contained respectively in two compartments (3,
4) of the sachet are applied to the hair, the sachet
comprising :
first and second opposite main walls and a partition separating an inside of the sachet into the two compartments, said partition having two opposite faces each facing one of the said two compartments, characterized in that first and second foldable side walls are fastened to respective opposite faces of the partition, the first foldable side wall being fastened to the first main wall and the second foldable side wall being fastened to the second main wall, the two being fastened to the second main wall, the two substances being mixed together extemporaneously.
24. A method of fabricating a sachet, the sachet comprising :
- first and second opposite main walls and
a partition separating an inside of the sachet into
the two compartments, said partition having two
opposite faces each facing one of the said two
compartments, characterized in that the sachet
comprises first and second foldable side walls
fastened to respective opposite faces of the partition, the first foldable side wall being fastened to the first main wall and the second foldable side wall being fastened to the second main wall,
the method comprising :
superposing flexible sheets for forming the two main walls (5, 6), the partition (9), and the foldable side walls,
folding each of the sheets for forming the side walls along at least one fold line (24), and - heat sealing the sheets, as superposed and folded to one another in a configuration corresponding to said sachet.
25. A method as claimed in claim 24, wherein the heat-sealing
in performed in such a manner as to leave the endpiece
(2) with an opening enabling filling to be performed, and
wherein the main walls are spaced apart during filling, and the opening that is used for filling is closed by heat sealing once the sachet (1) has been filled.
26. A sachet as claimed in claim 1, wherein the partition is
non foldable.