PRESSURE GENERATING APPARATUS AND METHOD

GENERATEUR DE PRESSION, ET MODE DE FONCTIONNEMENT

English Abstract

Abstract of the Disclosure
A flexible enclosed plastic bag disposable in a
product container for supplying dispensing pressure
therein. The bag contains an envelope having its outer
sides permanently attached to the respective inside walls
of the bag. One of the sides of the envelope has one of
a two component gas generating system disposed in a
plurality of aligned pocket members formed therein with
their openings facing the other side of the envelope, the
latter being releasably adhered to the first mentioned
side to enclose said one component in said pockets. The
bag contains the second component and a starting means
to initially generate gas and expand the bag and develop
product dispensing pressure within the container. As the
product is dispensed, expansion of the bag causes sequen-
tial separation of the sides of the envelope and serial
opening of the pockets to add aliquots of the first
component to the second component and further generate
gas and maintain said pressure in the container until
substantially all of the product is dispensed from the
container.

Claims

11
WHAT IS CLAIMED IS:
1. In an aerosol type dispenser, internal expulsion
means for developing and maintaining relatively constant
gaseous dispensing pressure for the product being dispensed,
said means comprising an enclosed, fluid impermeable flexible
pouch disposed within said dispenser, and having a pair of
facing wall members, a plurality of pocket members disposed
within said pouch in spaced relation to one another and
affixed to the interior of a first of said wall members,
closure members associated with the interior of the other
said wall member and releasably closing each of said pocket
members, a first component of a two-component gas genera-
tion mixture disposed within each pocket member, the second
component of said two-component gas generation mixture dis-
posed within said pouch and externally of said enclosed
pocket members, starting delay means disposed within said
pouch in contact with said second component for causing
the initial generation of gas after a prescribed period of
time, said pocket members being sequentially severable from
said closure member to empty their contents into admixture
with said second component to generate more gas as said
pouch expands due to the dispensing of said product.
2. In an aerosol type dispenser, internal expulsion
means for developing and maintaining relatively constant
gaseous dispensing pressure for the product being dis-
pensed, said means comprising an enclosed, fluid impermeable
flexible pouch disposed within said dispenser, and having a
pair of facing wall members, a plurality of interconnected
pocket members disposed within said pouch in spaced rela-
tion to one another and affixed to the interior of a first

12
of said wall members, a common closure member associated
with the interior of the other said wall member and re-
leasably closing each of said pocket members, a first
component of a two-component gas generation mixture dis-
posed within each pocket member, the second component of
said two-component gas generation mixture disposed within
said pouch and externally of said enclosed pocket members,
starting delay means disposed within said pouch in contact
with said second component for causing the initial genera-
tion of gas after a prescribed period of time, each said
pocket member being sequentially severable from said closure
member to empty their contents into admixture with said
second component to generate more gas as said pouch expands
due to the dispensing of said product.
3. In an aerosol type dispenser, internal expulsion
means for developing and maintaining relatively constant
gaseous dispensing pressure for the product being dispensed,
said means comprising an enclosed, fluid impermeable flexible
pouch disposed within said dispenser, and having a pair of
facing wall members, a plurality of interconnected pocket
members disposed within said pouch in spaced relation to
one another and affixed to the interior of a first of said
wall members, a common closure member associated with the
interior of the other said wall members and releasably
closing each of said pocket members, a first component of
a two-component gas generation mixture disposed within each
pocket member, the second component of said two-component
gas generation mixture disposed within said pouch and ex-
ternally of said enclosed pocket members, starting delay
means carrying a portion of said first component and dis-

posed within said pouch in contact with said second component for causing
the initial generation of gas after a prescribed period of time, said pocket
members being sequentially severable from said closure members to empty their
contents into admixture with said second component to generate more gas as
said pouch expands due to the dispensing of said product.
4. In the apparatus of claim 3, said pouch comprised of plastic, being
generally elongated and completely enclosed, and said pocket members being
disposed at spaced positions generally longitudinally of said pouch.
5. In the apparatus of claim 4, said pocket members being formed in
a first plastic sheet adhered to said first wall member and said common
closure member comprised of a second plastic sheet adhered to said other
wall member.
6. In the apparatus of claim 5, each said pocket member containing
citric acid solution as said first component and said pouch containing
sodium bicarbonate powder and water as said second component, and said gas
being carbon dioxide.
7. In a self-pressuring dispensing apparatus of the type having an
outer container, a manually actuatable atomizing and dispensing valve on
said container, a dispensible medium within said container and means within
said container for providing dispensing pressure for said medium, the
improvement comprising a liquid impermeable expansible envelope disposed
within said container, said dispensible medium disposed externally of said
envelope, a first component of a two-component gas generating composition
disposed within said envelope, and a pair of
13

14
sheets permanently attached on their outer surfaces to the
inner facing surfaces of said envelope and releasably ad-
hered to one another, at least one of said sheets having
a plurality of depressions in its surface each carrying an
aliquot of the second component of said composition, the
other sheet closing and encapsulating the second component
in said depressions and being adapted, upon outward expan-
sion of said envelope due to the pressure of carbon dioxide
generated therein and the dispensing of said medium through
said valve, to gradually separate from said first sheet
and to sequentially open the enclosed depressions thereby
permitting said aliquots of said second component to con-
tact said first component and generate additional carbon
dioxide within said envelope.
8. In a self-pressuring dispensing apparatus of the
type having an outer container, a manually actuatable
atomizing and dispensing valve on said container, a dis-
pensible medium within said container and means within said
container for providing dispensing pressure for said medium,
the improvement comprising a liquid impermeable expansible
envelope disposed within said container, said dispensible
medium disposed externally of said envelope, a first com-
ponent of a two-component gas generating composition dis-
posed within said envelope, and a pair of sheets permanently
attached on their outer surfaces to the inner facing sur-
faces of said envelope and releasably adhered to one another
over substantially their entire contacting surfaces, at
least one of said sheets having a plurality of depressions
in its surface each carrying an aliquot of the second com-
ponent of said composition, the other sheet closing and

encapsulating the second component in said depressions
and being adapted, upon outward expansion of said envelope
due to the pressure of carbon dioxide gas generated there-
in and the dispensing of said medium through said valve,
to gradually separate from said first sheet and to sequen-
tially open the enclosed depressions thereby permitting
said aliquots of said second component to contact said
first component and generate additional carbon dioxide
within said envelope.
9. In the apparatus of claim 7, said first component
comprised of a compound selected from the class consisting
of barium carbonate, calcium carbonate and sodium bicar-
bonate and said second component being a water soluble
acid.
10. In the apparatus of claim 7, said first component
comprised of sodium bicarbonate and said second component
being a water soluble carboxylic acid.
11. In the apparatus of claim 7, said first component
comprised of sodium bicarbonate and said second component
being citric acid.
12. In the apparatus of claim 11, said envelope com-
prised of a three layer laminated plastic, the external
layer being mylar polyester 0.5 to 3.00 mils in thickness,
the inner layer being low density polyethylene 0.5 to 20
mils in thickness, and the middle layer being saran deposited
by spraying at least one of the inner surfaces of said
mylar and polyethylene layers.
13. In the apparatus of claim 12, the sheet of said
pair carrying said depressions comprised of a two-layer
plastic lamination having an outer layer of low density

16
polyethylene about 0.5 to 10.00 mils thick attached to
said envelope and an inner layer of polypropylene 0.1 to
8 mils thick.
14. In the apparatus of claim 13, the other said
sheet of said pair comprised of a three layer plastic
sandwich lamination having an inner Mylar layer of 0.3 to
3.00 mils thickness, the other layers of the sandwich
having low density polyethylene of 0.3 to 20 mils thick
each.
15. In a self-pressuring dispensing apparatus of the
type having an outer container, a manually actuatable
atomizing and dispensing valve on said container, a dis-
pensible medium within said container and means within
said container for providing dispensing pressure for said
medium, the improvement comprising a liquid impermeable
expansible envelope disposed within said container, said
dispensible medium disposed externally of said envelope,
a first component of a two-component gas generating com-
position disposed within said envelope, and an enfoldment
of two sheets permanently adhered on their outer surfaces
to the inner facing surfaces of said envelope and releas-
ably adhered to one another, at least one of said sheets
having a plurality of depressions in its surface each
carrying an aliquot of the second component of said com-
position, the other sheet enclosing and encapsulating the
second component in said depressions and being adapted,
upon outward expansion of said envelope due to the pressure
of carbon dioxide generated therein and the dispensing of
said medium through said valve, to gradually separate from
said first sheet and to sequentially open the enclosed

17
depressions thereby permitting said aliquots of said
second component to contact said first component and
generate additional carbon dioxide within said envelope.
16. In a self-pressuring dispensing apparatus of
the type having an outer container, a manually actuatable
atomizing and dispensing valve on said container, a liquid
medium within said container to be dispensed, and means
within said container for providing dispensing pressure
for said medium, the improvement comprising a liquid im-
permeable expansible envelope disposed within said con-
tainer, said liquid medium disposed externally of said
envelope, a first component of a two-component carbon
dioxide generating composition disposed within said
envelope, and a pair of two generally congruent sheets
permanently adhered on their outer surfaces to the inner
facing surfaces of said envelope and releasably adhered
along at least portions of their respective margins to
one another, at least one of said sheets having a plurality
of cup-shaped depressions in its surface at longitudinally
spaced positions each carrying an aliquot of the second com-
ponent of said composition, the other sheet enclosing and
encapsulating the second component in said depressions and
being adapted, upon outward expansion of said envelope due
to the pressure of carbon dioxide generated therein and
the dispensing of said medium through said valve, to
gradually separate from said first sheet and to sequentially
open the enclosed cups thereby permitting said aliquots of
said second component to contact said first component and
generate additional carbon dioxide within said envelope.
17. In a self-pressuring dispensing apparatus of the

18
type having an outer container, a manually actuatable
atomizing and dispensing valve on said container, a liquid
medium within said container to be dispensed, and means
within said container for providing dispensing pressure
for said medium, the improvement comprising a liquid im-
permeable expansible envelope disposed within said con-
tainer, said liquid medium disposed externally of said
envelope, a first component of a two-component carbon
dioxide generating composition disposed within said enve-
lope, and an enfoldment of two generally congruent sheets
permanently adhered on their outer surfaces to the inner
facing surfaces of said envelope, and releasably adhered
along at least portions of their respective margins to one
another, at least one of said sheets having a plurality of
cup-shaped depressions in its surface at longitudinally
spaced positions each carrying an aliquot of the second
component of said composition, the other sheet enclosing
and encapsulating the second component in said depressions
and being adapted, upon outward expansion of said envelope
due to the pressure of carbon dioxide generated therein and
the dispensing of said medium through said valve, to gradually
separate from said first sheet and to sequentially open the
enclosed cups thereby permitting said aliquots of said
second component to contact said first component and generate
additional carbon dioxide within said envelope.
18. In the apparatus of claim 16, said first com-
ponent being sodium bicarbonate solution, said second com-
ponent being citric acid solution, and said apparatus in-
cluding delaying means within said envelope encapsulating
sodium bicarbonate for introducing said sodium bicarbonate

19
into said citric acid solution to initiate the generation of carbon dioxide
gas within said envelope after a predetermined time
delay.
19. Expulsion means for developing and maintaining
relatively constant gaseous dispensing pressure in a con-
tainer for a product being dispensed from said container,
said means comprising an enclosed, fluid impermeable flexible
pouch adapted to be disposed within said container and
having a pair of facing wall members, a plurality of
pocket members disposed within said pouch in spaced re-
lation to one another and each affixed to the interior of
a respective one of said wall members, a closure member for
each pocket member associated with the interior of the
other said wall member and releasably enclosing said pocket
member, a first component of a two-component gas genera-
tion mixture disposed within each pocket member, the second
component of said two-component gas generation mixture dis-
posed within said pouch and externally of said enclosed
pocket members, starting delay means carrying a portion of
said first component and disposed within said pouch in
contact with said second component for causing the initial
generation of gas after a prescribed period of time, said
pocket members being sequentially severable from its clo-
sure member to empty its contents into admixture with said
second component to generate more gas as said pouch expands.
20. Expulsion means for developing and maintaining
relatively constant gaseous dispensing pressure in a con-
tainer for a product being dispensed from the container,
said means comprising an enclosed, fluid impermeable
flexible pouch adapted to be disposed within said container
and having a pair of facing wall members, a plurality of

pocket members disposed within said pouch in spaced re-
lation to one another and affixed to the interior of a
first of said wall members, a common closure member asso-
ciated with the interior of the other said wall member
and releasably enclosing each of said pocket members, a
first component of a two-component gas generation mixture
disposed within each pocket member, the second component
of said two-component gas generation mixture disposed
within said pouch and externally of said enclosed pocket
members, starting delay means carrying a portion of said
first component and disposed within said pouch in contact
with said second component for causing the initial genera-
tion of gas after a prescribed period of time, said pocket
members being sequentially severable from said closure
member to empty its contents into admixture with said second
component to generate more gas as said pouch expands.
21. Expulsion means for developing and maintaining
relatively constant gaseous dispensing pressure in an
aerosol type dispenser for the product being dispensed,
said means comprising an enclosed, elongated fluid im-
permeable flexible pouch adapted to be disposed within
said dispenser, and having a pair of facing wall members,
a plurality of pocket members disposed within said pouch
in spaced relation to one another and generally longitudin-
ally of said pouch and affixed to the interior of a first
of said wall members, a common closure member associated
with the interior of the other said wall member and re-
leasably enclosing each of said pocket members, a first
component of a two-component gas generation mixture dis-
posed within each pocket member, the second component of

21
said two-component gas generation mixture disposed within
said pouch and externally of said enclosed pocket members,
starting delay means carrying a third component and dis-
posed within said pouch in contact with said second com-
ponent for causing the initial generation of gas after a
prescribed period of time, said pocket members being se-
quentially severable from said closure member to empty
their contents into admixture with said second component
to generate more gas as said pouch expands.
22. In the apparatus of claim 19, said pouch com-
prised of laminated plastic film having an interior layer
of low density polyethylene, said pocket members comprised
of laminated plastic film having an exterior layer of low
density polyethylene from about 0.5 to about 20 mils thick
and an interior layer of polypropylene from about 0.1 to
about 10.00 mils thick, and said polyethylene layers of
said pouch and said pocket members being permanently heat
sealed together.
23. In the apparatus of claim 22, each said closure
member having at least one surface comprised of low density
polyethylene of from about 0.1 to 20 mils thick and being
permanently adhered to the interior of its associated wall
member at that surface.
24. In the apparatus of claim 23, each said pocket
member and its closure member being releasably heat sealed
together.

25. In the apparatus of claim 5 a plurality of relatively short heat
sealed portions, each adjacent and laterally spaced from a respective one of
said pocket members, said heat sealed portions permanently joining said first
wall member and said first sheet and said second wall member and said second
sheet, and releasably joining said second sheet relative to said first sheet,
said heat sealed portions being staggered diagonally longitudinally relative
to said pocket members to accommodate sequential expansion of said pouch
during use.
22

Description

., 1 1~8~308
PRESSURE GENERATING APPARATUS AND METHOD
Background of The Invention
For a long time there has been a need for a pressure
generating system for use in product dispensing containers
that is isolated from, and is not dispensed with, the
product. This need has been partially due to environ-
mental considerations but also for safety precautions,
avoidance of product ~ontamination or dilution as well as
skin toxicity andjor irritation.
Furthermore, prior aerosol type dispensers generally
were operable only in an upright condition, otherwise pre-
mature exhaustion of the dispensing medium would result
with a substantial loss of usable product which would re-
main indispensable in the container due to loss of dis-
pensing pressure.
~ 15Prior dispensers also had other deficiencies such as
i ~ temperature sensitivity, non-uniform dispensing pressure,
mited shelf-life, unreliability, difficulty of manu-
facture and relatively high cost of manufacture.
The present~invention provides a dispensing mechanism
~which overcomes the above-mentioned deficiencies of the
prior art devices and provides additional novel features
:and advantages, and a wider range of uses, than were
possible wlth devices used heretofore.
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Brief Summary of the Invention
According to one aspect, the present invention provides in an aerosol
type dispenser, internal expulsion means for developing and maintaining
relatively constant gaseous dispensing pressure for the product being dispensed,
said means comprising an enclosed, fluid impermeable flexible pouch disposed
within said dispenser, and having a pair of facing wall members, a plurality
of pocket members disposed within said pouch in spaced relation to one another
and affixed to the interior of a first of said wall members, closure members
associated with the interior of the other said wall member and releasably
closing each of said pocket members, a first component of a two-component gas
generation mixture disposed within each pocket member, the second component
of said two-component gas generation mixture disposed within said pouch and
externally of said enclosed pocket members, starting delay means disposed
within said pouch in contact with said second component for causing the
initial generation of gas after a prescribed period of time, said pocket members
being sequentially severable from said closure member to empty their contents
into admixture with said second component to generate.more gas as said pouch
expands due to the dispensing of said product.
According to another aspect, the present invention provides in a self-
pressuring dispensing apparatus of the type having an outer container, a
manually actuatable atomi7ing and dispensing valve on said container, a
dispensible medium within said container and means within said container for
provlding tispensing pressure for said medium, the improvement comprising a
liquid impermeable expansible envelope disposed within said container, said
dispensible medium disposed externally of said envelope, a first component of
a two-component gas generating composition disposed within said envelope, and
a pair of sheets permanently attached on their outer surfaces to the inner
facing surfaces of said envelope and releasably adhered to one another, at
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least one of said sheets having a plurality of depressions in its surface each
carrying an aliquot of the second component of said composition, the other
sheet closing and encapsulating the second component in said depressions and
being adapted, upon outward expansion of said envelope due to the pressure of
carbon dioxide gener~ted therein and the dispensing of said medium through
said valve, to gradually separate from said first sheet and to sequentially
open the enclosed depressions thereby permitting said aliquots of said second
component to contact said first component and generate additional carbon
dioxide within said envelope.
According to a further aspect, the present invention provides
expulsion means for developing and maintaining relatively constant gaseous
dispensing pressure in a container for a product being dispensed from said
container, said means comprising an enclosed, fluid impermeable flexible pouch
adapted to be disposed within said container and having a pair of facing wall
members, a plurality of pocket members disposed within said pouch in spaced
relation to one another and each affixed to the interior of a respective one
of said wall members, a closure member for each pocket member associated with
the interior of the other said wall member and releasably enclosing said
pocket member, a first component of a two-component gas generation mixture
disposed within each pocket member, the second component of said two-component
:: gas generation mixture disposed within said pouch and externally of said
enclosed pocket members, starting delay means carrying a portion of said first
component and disposed within said pouch in contact with said second component
for causing the initial generation of gas after a prescribed period of time,
said pocket members being sequentially severable from its closure member to
; empty its contents into admixture with said second component to generate more
gas as said pouch expands.
The first component of the two-component gas generation mixture may
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be, for example, sodium bicarbonate. The second component of the two-component
carbon dioxide gas generation mixture may be, for example, citric acid solution.
The starting delay means may be a rupturable or dissolvable capsule containing
sodium ~icarbonate and/or lithium carbonate disposed within the pouch in
contact with the second component for causing the initial generation of carbon
dioxide gas.
Description of thc Drawings
Figure 1 is an elevation sectional view of an aerosol dispensing
container including an expulsion means embodi-
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ment of the present invention shown in a fragmentary
cutaway view;
Fig. 2 is a sectional plan view of the structure
shown in Fig. 1 shown in theexpulsion means in initial
collapsed condition;
Fig. 3 is a sectional plan view of the device of
Fig. 2 showing the expulsion means in intermediate
expanded condition;
Fig. 4 is an enlarged isometric view of the two
envelope sheets of an embodiment of the invention prior
to assembly;
Fig. 5 is an enlarged isometric view of the two
envelope sheets of Fig. 4 in assembled condition;
Fig. 6 is a sectional view taken along lines 6-6 of
Fig. 5;
Fig. 7 is an enlarged schematic showing the method
of insertion of the envelope into the pouch;
Fig. 8 is an enlarged schematic showing heat sealing
of the envelope sides to the inner walls of the-pouch;
Figs. 9 through 11 are reduced sectional elevations
showing assembly of the envelope containing pouch into an
aerosol type dispenser;
Figs. 12 and 13 are enlarged fragmentary schematic
views showing separation of the envelope sides during
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~ ~ 25 expansion to open the pocket members; and
;~ ~ Figs. 14 through I7 are schematic representations of
different arrangements of the pocket members and different
patterns of attachment of the envelope sides to the pouch
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Detailed Description
Referring now to the drawings, in which each of the
various components have the same reference numeral in the
different views, ana in particular Figs. 1-3, a fluid tight
dispensing container is shown and designated generally by
reference numeral 10. Container 10 has a cylindrical body
or sidewall 11, inwardly dished bottom 12 and bell-shaped
top 13 in which is mounted a conventional spring loaded
aerosol spray valve assembly 14. Container 10 and its
component parts just described can be fabricated from any
suitable material such as thin gauge aluminum or other
metal, or even plastic depending on the product to be
dispensed and any governing safety specifications that
might be involved. Valve assembly 14 is also of conven-
tional design having plunger and spray head 15 carryingspray orifice 16, suitably constructed of plastic, and
internal parts (not shown) such as a spring, ball valve
and mounting ring 17 and bottom intake member 18 which may
be of metal and/or plastic consistent with the previously
mentioned requirements.
Within container 10 is liquid product 19 and expulsion
assembly 20 which is the subject of the present invention
and as will be seen generates and maintains gas pressure
within container 10 to enable product 19 to be dispensed
25~ on demand.
At the upper end 21 of the interior of cylindrical
body 11 is a perforated or foraminous barrier member 22
having a plurality of holes 23 distributed throughout its
surface. Also affixed to inner surface 24 of sidewall 11
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and extending longitudinally there along is a perforate
tube member 25 having a plurality of holes 26 at spaced
positions around and along said tube member 25. The func-
tion of barrier member 22 and tube member 25 is to insure
trouble-free operation of the dispenser and prevent expul-
sion assembly 20, as it expands in the manner to be
described, from blocking off or plugging the interior of
the container either laterally/circumferentially or plug-
ging off the valve bottom intake member 18.
Expulsion assembly as shown is disposed within con-
tainer 10 without being attached or anchored to container
10, although it may, if desired be so connected. Assembly
20 is comprised of generally rectangular envelope, bag or
pouch 27 which is constructed of a flexible, fluid imper-
meable plastic such as, for example, polyethylene or poly-
propylene and may be fabricated from a sheet of plastic by
folding it into overlaid halves 27a, 27b which are then
sealed or adhered by suitable means along their respective
contacting side, bottom and top edges 28, 2g, 30 respective-
ly to form a sealed enclosure as shown in Figs. 1-3
inclusive.
Disposed within pouch 27 is fluid impermeable flexible
plastic sandwich or enfoldment 31 having a pair of facing
,
wall members 32, 33 releasably adhered to one another (see
~; 25 also Figs. 2 through 6) and permanently attached by suitable
means such as heat sealed portions 35 to respective interior
sides 27c, 27d of pouch halves 27a, 27b respectively. One
wall member 32 is a substantially flat and the other wall
member 33 has a plurality of cup-shaped depressions,
cavities or pocket members 34 disposed inwardly from one

~ ~8~8
surface thereof at spaced positions and aligned generally longitudinally of said
enfold~lent 31 which in tu~n is simila~ly al~gned with respect to said envelope
20 in a substantially longitudinal relationship as shown in Fig. 1. Pocket
members 34 are "lidded" or closed by wall member 32 to encapsulate within each
cavity 34 an aliquot of sodium bicarbonate 36 which may be either in the form
of powder or a solution. In the interior of pouch 27 is citric acid solution
37. Also disposed in said citric acid solution is starting means 38 which as
shown is in the form of a dissolvable capsule and contains an initial charge of
sodium bicarbonate which, after a predetermined period of time after assembly
of the pouch 27 in container 10, filling the container with product 19 and
capping it with the top 13 and associated parts, capsule 38 dissolves and
causes the sodium carbonate contained therein to mix with the citric acid
solution 37 and generate the initial quantity of carbon dioxide gas, thereby
expanding envelope or pouch 27 and providing dispensing pressure within con-
tainer 10.
The pouch member 27 in one preferred embodiment is constructed of a
three layer laminated film having a middle layer of saran, the external layer
of Mylar* and the inside layer (interior of the pouch) being low density
polyethylene, each of said layers being approximately 2.5 mils in thickness
except for the saran layer, which is only deposited from a spray. The
characteristics required or desired in said pouch is that it be non-toxic,
have sufficient mechanical strength and chemical stability, be heat sealable
(to the wall members) and flexible but not appre-
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ciably elastic or stretchable.
Wall member 32 is fabricated from material which con-
tacts the bag 27 and is of compatible plastic, e.g.,
polyethylene. In one preferred embodiment it has an over-
all thickness of about 4.5 mils and is a three layersandwich of about 0.5 mil Mylar in the middle and about
2.0 mils low density polyethylene either side.
Wall member 33 carrying the cup-shaped depressions
34 is adapted for deep drawing and is in one preferred
embodiment a laminated plastic having an exterior iayer
(the layer in contact with pouch 27) of low density poly-
ethylene of from about 0.5 to about 20 mils thick and an
interior layer (the other side) of polypropylene of from
about 0.1 to about 3.75 mils thick or higher. It is to
be understood that cavities 34 and capsule 38 may carry
the citric acid and solution 37 may be sodium bicarbonate
and water, or the two carbon dioxide generating components
can be switched the other way around.
A typical formulation is for each depression 34 and
the capsule 38 to be charged with about 1 gram each of a
50% citric acid solution and the envelope content 37 to be
about 5 to 10 grams of sodium bicarbonate mixed with about
S grams of water.
The pressure generated within container 10 is of the
order of about 120 psig +20~ at an ambient temperature of
about 70F, but any desired pressure may be developed by
adjusting the stoichiometry of the particular gas-generat-
; ing ingredients.
While fGr most practical applications of the invention
sodium bicarbonate and citric acid are normally preferred,
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8~3()8
it is possible that under particular circumstances other
materials may be more suitable such as, for example, dilute
hydrochloric acid (e.g., 10-30% even up to about 35%) in
place of the citric acid, and lithium carbonate or calcium
carbonate in place of the sodium bicarbonate.
Various starting delay means can be employed in addi-
tion to dissolvable capsule 38.
The method of assembly is depicted schematically in
Figs. 4-8 and 9-11. Sheet 33 is formed in a mold by heating
and drawing to form cavities 34. The cavities are then
filled with one component, e.g., citric acid. Sheet 32 is
overlayed on sheet 33 to close cavities 34 and the two wall
members are heat sealed together (Fig. 5) and enfoldment 31
is inserted into the open end 39 of pouch or bag 27 (Fig.
7) and the two members 31 and 27 are heat sealed together
at 35. Sodium carbonate solution 37 and starting capsule
38 are added to pouch 27 and then upper edge 30 of pouch 27
is heat sealed to completely enclose the contents in pouch
27 (Fig. 8). The expulsion means assembly 20 is then in-
serted into container 10 and product 19 added, barrier mem-
ber 22 put into place, and top 13 affixed to container 10
(Fig. 10). After elapse of the prescribed period of time,
starting capsule 38 has dissolved, generating carbon
dioxide gas, expanding pouch 27 and the dispenser is now
ready for use (Fig. 11). Figs. 3, 12 and 13 show schematic-
ally how expansion of pouch 27, to separate inner sides of
which wall members 32, 33 are permanently attached, succes-
sively pulls apart portions of releasably adhered wall mem-
bers 32, 33 to successively expose the contents of each
cavity 34 and deliver it into contact and admixture with
.
.; . .
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:
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,

~1~8.~08
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other gas generating component 37 in the bottom of the
pouch.
Figs. 14-17 depict variations in the arrangement of
cavities 34 and heat seals 35 as well as in configurations
and relative dimensions of pouch 27 and enfoldment 31.
A dispensing apparatus containing the expulsion means
of the present invention has the following advantages and
features:
1. no flammable propellants are used, thereby eli-
minating the dangers of prior art assemblies;
2. the assembled containers can be steam sterilized
without affecting operating performance;
3. a constant balanced internal dispensing pressure
is maintained at the user's demand and insures a
continual even flow of product at room temperature,
regardless of the amount of product remaining in the
container;
4. the product never comes into contact with the
:~ propellant, eliminating any danger of contamination
of the product, such as taste or smell:
5. the dispenser will discharge its contents in any
position, uprigh*, horizontal or inverted and with-
: out escape of propellant;
~:
6. the spray does not chill the sprayed surface as
is caused by hydrocarbon propellants;
~.: ~: :
~ 7. there is no pollution or contamination of the
. :
atmosphere with the propellant becauæe it remains
in the container; and
8. ea~e and low cost of manufacture, extended
: 30 shelf life and reliability of service make this
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.,
"~ ,

8908
dispenser highly advantageous over prior art dis-
pensers.
While certain embodiments of the invention have been
shown and described herein, it is to be understood that
changes and additions may be made by those skilled in the
art without departing from the scope and spirit of the
invention.
.
:
:
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