Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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IMPROVED EXPANDIBLE PACKAGE
FOR DISPENSING CONTAINERS
This invention relates to product dispens-
ing containers wherein the container contents are forced
out by internal pressure, usually under control of a
valve at the top of the container. More particularly,
this invention relates to a sealed package to be in-
serted in such a container to develop the dispensing
pressure.
U.S. Patent No. 3,718,236 discloses a system
for generating pressure within a dispensing container by
mechanically combining two or more reactive chemicals in
a sealed bag-like structure free-floating within the
container. In one disclosed arrangement, the bag includes
a number of sealed compartments containing sodium bicar-
bonate which are ruptured to combine that chemical with
a mixture of citric acid and water so as to develop gas
pressure within the bag. The rupturing of these compart-
ments is carried out sequentially as the dispensing
operation proceeds, in order to develop successive in-
crements of additional pressurized gas as required to
2~ maintain an approximately constant pressure within the
container as the contents are dispensed.
The bag-like structures shown in United States Patent
3,718,236 are relatively complex and difficult to manufacture by
conventional processes. ~lthou~h the basic structure can be sub-
divided into simpler components for separate manufacture, that
approach requires processing by at least two different types of
machines to make the complete assembly, thus resulting in undesi-
rably high cost.
The present invention provides in a package to be inser-
ted in a container to develop pressure for dispensing the con-
tainer contents, the package being of the type comprising a sealed
enclosure formed by flexible sheet material and containingtherewithin a set of chemicals to be reacted together to form an
initial gas pressure, the sealed enclosure further containing a
plurality of individually sealed cells containing additional
reactant chemicals and arranged to be ruptured sequentially as the
package expands during a dispensing operation to effect reaction
between the additional chemicals and one or more of the set of
chemicals to produce additional increments of gas pressure within
the sealed enclosure; that improvement in such a package wherein;
the sealed enclosure comprises a first outer sheet member formed
with a plurality of pockets opening into the interior of the
enclosure; at least one of the pockets containing a first chemical
component of the set of chemicals; at least another of the pockets
containing a second chemical component OL the set of chemcials
and capable of reacting with the first chemical component to
develop an initial dispensing gas pressure; the plurality of
pockets in the first outer sheet member further comprising a set
of pockets containing additional chemical material capable of
reacting with at least one of the chemical components to develop
further dispensing pressure; the sealed enclosure including a
second outer sheet member seal.ed peripherally to the first outer
sheet member to form therewith the sealed enclosure encompassing
all of the pockets; a tape member between the first and second
outer sheet members and positioned over the openings of the set
of pockets, the tape member being sealed around the peripheries
of the openings to prevent the chemical material therein from
coming into contact with the chemical components; the tape
member being secured to the second outer sheet member to provide
for progressive lift-off of the tape member from the first outer
sheet member to open the peripheral sealsaround the set of
pockets in se~uence as the two outer sheet members separate during
a dispensing operation, thereby permitting reactive contact
between the additional chemical material and at least one of the
chemical components to develop additional increments of gas
pressure within the package.
The present invention also provides a package to be
inserted in a conta.iner for developing expansive pressure to force
out and dispense the contents of the container, comprising: a
first outer sheet member formed with a plurality of pockets; at
least one of the pockets containing a first chemical component;
at least another of the pockets contai.ning a second component
capable of reacting with the first chemical component to develop
an initial dispensing gas pressure; the plurality of pockets
further comprising a set of pockets containing additional chemical
material capable of reacting with at least one of the chemical
components to develop further dispensing pressure; a second outer
sheet member sealed peripherally to the first outer sheet member
to form therewith a sealed enclosure encompassing all of the
pockets; a tape member between the outer sheet members and
positioned over the openings of the set of pockets, the tape
member initially being sealed around the peripheries of the
openings to prevent the chemical material from coming into contact
with either of the chemical components; and the tape member being
secured to the second sheet member to provide for progressively
opening the peripheral seals around the set of pockets as the
two sheet members separate during a dispensing operation, thereby
permitting reactive contact between the chemical material and at
least one of the chemical components to develop additional gas
pressure within the package.
The present invention also provides a method of making
a sealed package for developing expansive pressure within a
dispensing container, comprisi.ng the steps of: forming a first
sheet member with at least first and second separate pockets and
an additional set of pockets; depositing in the first and second
pockets first and second chemical components which are capable of
reacting together to produce gas pressure; depositing into the
additional set of pockets a chemical material capable of reacting
with one of the chemical components to develop gas pressure;
positioning a tape member over the openings of the additional set
of pockets; sealing a second sheet member to the first sheet
member with a peripheral seal to establish a sealed enclosure
encompassing all of the pockets and the tape member; and securinq
the second sheet member to ~he tape member to provide for
progressive lift-off of the tape member from the set of pockets
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when the two sheet members separate as the package expands during
a dispensing operation.
Other objects, aspects and advantages of the invention
will in part be pointed out in, and in part apparent from, the
following description of a preferred embodiment of the invention,
considered together with the accompanying drawings.
FIGURE 1 is a plan view of the initial forming station
for forming the bottom sheet of the package with pockets;
FIGURE 2 shows the formed bottom sheet of the package
with a tape member sealed thereto over certain of the pocketsi
FIGURE 3 shows the formed bottom sheet with a top sheet
sealed thereto and to a part of the tape member;
FIGURE 4 is a longitudinal section taken along line 4-4
of Figure 3;
FIÇU~E 5 is a longitudinal section taken along line 5-5
of Figure 3;
FIGURE 6 is a cross-section taken alon~ line 6-6 of
Figure 3;
FIGURE 7 is a perspective vi~w of the complete package
ready for insertion into a container to be pressurized; and
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1179993
FIGURE 8 is a plan view of another embodi-
ment of this invention.
Referring now to Figure 1, there is shown
a sheet of flexible plastic packaging material 20 which
is transported (from left to right) to a forming station
22 ~y conventional conveying means (not shown). This
sheet may for example be a 2-layer film or web com-
prising polyethylene/polypropylene, with the polyethylene
facing upwards. In the station 22, thermoforming
operations are carried out in accordance with known
processes to form the sheet 20 with a number of pockets
generally indicated at 24, 26 and 28, and adapted to
receive chemicals to be reacted together for developing
gas pressure.
In typical machine operations, such thermo-
forming of the sheet 20 preferably is carried out in
multiple across the width of the plastic film 20, for
example, four abreast, as shown in Figure 1 between the
machine frames 29. However, to simplify the presenta-
tion, only one of the four identical formed sections
will be described in detail hereinafter.
Returning now to the detailed description,
the first of the formed pockets 24 may be circular in
plan view, and provides a cell for holding one or more
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tablets or capsules containing citric acid in solid
form. The second of the pockets 26 is developed in
- this embodiment as three distinct but inter-
communicating rectangular cells for holding a mixture
of bicarbonate of soda and water. The remaining set
of pockets 28 provides a number (seven in this case)
of separate but closely adjacent cells for holding
citric acid in the form of a solution. The pockets
24-2B are filled with chemical materials as set forth
above (not shown in the drawings), in any convenient
way, at the station 22 or at a subsequent station.
Thereafter, the formed and filled sheet
member 20 is transported to another station 30
(Figure 2) where a rectangular tape 32 is positioned
over the set of pockets 28 and is heat-sealed to the
sheet member 20 around the peripheries of the individual
cells, e.g. closely adjacent the open mouths of the
pockets, as illustrated by the shading at 34. The tape
32 is a strip-like member of flexible plastic material.
This tape is heat-sealed uniformly but lightly to the
upper surface of the bottom sheet 20 in such a way that
it can be pulled away with relatively low force, e.g.
300 to 1000 grams per inch of width. The tape may for
example be a 3-layer film comprising polyethylene/
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polyester/polypropylene, with the polypropylene being
the bottom layer sealed to the polyethylene layer of
the bottom sheet member 20 and advantageously providing
the light-force peelability as described. Peelability
in this case means that the pull force should be suffi-
ciently light that the two films can readily be
separated without resulting in any tearing of the films.
With the tape 32 sealed in place as des-
cribed, the bottom sheet 20 is moved forward to a sub-
sequent station 38 (Figure 3) where a second sheet offlexible plastic packaging material 40 is applied over
the first sheet 20 and the tape 32, as with the aid of
a laydown roller 41. This second sheet is heat-sealed
in peripheral fashion around the first sheet, as in-
dicated by the shading 42, to form a strongly sealedenclosure encompassing all of the pockets 24-28 as
well as the tape 32. This top sheet 40 also is secured
to the tape 32, as by heat-sealing the two together
along a narrow line 44 adjacent the pockets 28.~ This
seal, like seal 42, is a strong seal capable of holding
the films together during normal operation of the pack-
age, capable of resisting a force orders of magnitude
greater than the force needed to open the peelable seal
34. Thus the seals 42 and 44 effectively serve as welds,
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whereby application of a sufficiently large force
would tear the film material rather than open the
seal. Figures 4-6 further illustrate the sealing con-
figuration, with certain aspects of the interfilm spac-
ing somewhat exaggerated to clarify the relationshipsinvolved. See also Figure 7 for an overall perspective
view of the final package.
The top sheet 40 may for example be a 2-
layered film or web consisting of polypropylene/poly-
ethylene, with the polyethylene on the lower (inner)side, facing downwards towards the tape 32. This
combination of materials provides for a very strong
seal between the top sheet and the tape at 44, and be-
tween the top and bottom sheets at 42, because both are
polyethylene-to-polyethylene seals.
It may be noted that if the heat applied in
making the seal 44 also produces unintended sealing be-
tween the tape 32 and the bottom sheet 20, it will be a
weak polypropylene-to-polyethylene seal, using the types
of sheet and tape materials suggested above, and will not
interfere with the pulling of the tape up from the bottom
web with only a light pulling force. When making the
seal 44, the amount of heat reaching the interface be-
tween the tape 32 and the bottom sheet 20 will be signi-
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ficantly less than that producing the seal 34, whenusing comparable heat sealing devices for both seals
~ 34 and 44, so if an inadvertent seal develops along
line 44 between the tape and the bottom sheet it will
be of even less strength than the light-force seal
between the tape and the bottom sheet at the seal line
34. It will of course readily be understood by those
skilled in the art that other techniques can be used
for establishing a strong secure seal between the top
sheet member 40 and the tape 32 along line 44 while
assuring that the tape can readily be peeled up away
from the bottom sheet member with only a small force.
The completed package thereafter is cut from
the forming webs and is ready for use. When the package
is tilted, the water and sodium bicarbonate mixture in
the cells 26 will flow to the tablets or capsule in
cell 24, thus starting gas production within the sealed
package. Gas production will normally be slow enough
to allow time to load the package into a dispensing con-
tainer, particularly if known means are employed to slowdown the reaction.
As a dispensing operation proceeds, the
package expands to fill the space left by the dispensed
contents. Thus the two sheet members 20 and 40 are
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gradually forced apart, especially in the central region
adjacent the seal line 44. This expansion thus also
lifts up the tape 32 in a progressive fashion, starting
at the inner edge of the tape which runs parallel to the
seal line 44, and moving outwardly towards the side edge
of the package, across the set of pockets 28. Since
these pockets are staggered, the progressive lift-up of
the tape causes the individual cells to be opened sequen-
tially, thus developing successive additional increments
of gas pressure to tend to maintain the internal container
pressure approximately constant.
Figure 8 shows an alternative package design
embodying the same basic invention described above, and
formed using the same method sequences. In this alterna-
tive design, the bottom sheet 20 is first formed with anumber of pockets including a generally rectangular pocket
50 at one end of the package. This pocket may be filled
with a liquid reactant chemical such as bicarbonate of
soda and water. A second pocket 52 of generally oval
shape also is formed in the bottom sheet 20 at the same
time, in a more central region adjacent one side of the
sheet. This pocket may for example receive a solid re-
actant che~ical such as one or mote capsules or tablets
containing acetic acid crystals, capable of reacting
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with the bicarbonate of soda in the first pocket 50 to
start the initial gas formation.
~ The bottom sheet 20 of the Figure 8 design
also is formed at the same time with a number of indivi-
dual cells 54 and filled, for example, with dilute citric
acid in liquid form. The openings of these cells then are
covered by a single tape member 32 as described above,
laid down on the bottom sheet 20, as by a machine opera-
tion at the forming station or a subsequent station, and
sealed around the cell openings as at 34 to prevent con-
tact between the liquid therein and the remainder of the
reactant chemicals placed in the other two pockets. The
tape member is secured to the bottom sheet with a rela-
tively weak seal, as described hereinabove, to permit the
tape member readily to be pulled up away from the bottom
sheet 20 by relatively small force, to open up the cells
54 progressively as the package expands during a dispens-
ing operation.
A top sheet 40 is then applied over the
bottom sheet 20, and is sealed to the bottom sheet around
the periphery thereof as shown at 42, to form a strongly
sealed enclosure encompassing the pockets 50, 52, 54 and
the tape member 32. The top sheet also is sealed to the
tape member alon~ a centrally located line 44. This
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also is a strong seal, to hold those two films together
during expansion of the package, thereby to effect lift-
off of the tape member 32 from around the cells 54, just
as in the fi st embodiment described. The materials of
the top and bottom sheets and the tape member preferably
are selected to assure that any unintended sealing ef-
fected between the tape member and the bottom sheet, oc-
curring during sealing of the top sheet to the tape mem-
ber, will be so weak as to be easily broken as force is
applied to lift the tape member up from the bottom sheet
during expansion of the package. Examples of such film
materials are described above with reference to the
Figures 1-7 embodiment, although other materials can be
suitable for these purposes.
The functioning of this alternative package
design is the same as in the first embodiment of Figures
l-7, in that the reaction of the material in the two
larger pockets 50 and 52 pro~ides an initial gas pressuri-
zation after the package has been tilted to bring the
chemicals together. Thereafter the package is inserted
into a dispensing container to apply force to the contents
to effect dispensing thereof. The expansion of the pack-
age during dispensing pushes apart the bottom and top
sheets 20 and 40 thereby lifting up the tape member 32
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progressively from the cells 54, to add successive in-
crements of reactant chemical sequentially from those
cells to the chemical material which already is producing
pressurized gas, thereby to tend to augment the pressur-
izing gas so as to maintain roughly constant the levelof pressurization within the container throughout a
complete dispensing operation.
Although preferred embodiments of the inven-
tion have been described in detail, it is desired to
stress that this is for the purpose of illustrating the
principles of the invention, and should not be con-
strued as limiting of the invention since it is apparent
that those skilled in this art can make modifications
to the disclosed package and packaging methods without
departing from the true scope of the invention.
