Field of Art
[0001] The invention relates to packaging techniques and can be used, for instance, in aerosol
packages, purposed for applying paint and varnish coatings, in medicine, mainly for
breast diseases prophylaxis and treatment and local anaesthesia, in perfumery, and
also in housekeeping for spraying different household chemical substances etc.
Prior Art
[0002] One of the global problems is an increasing adverse effect of the human activity
on the environment, and in particular, the deflection of the protective ozone layer
under the influence of chlorine-containing substances, the usage of which was limited
by the Montreal Protocol. Due to this reason, the alternative technical methods for
creation of positive pressure within the package are being proposed in order to decrease
or eliminate the hazardous effect on the environment.
[0003] In the art are known methods for creation of positive pressure for gaseous substances
within the working cavity of aerosol package (European Patent Application EP - A -
385773, Int. Cl. F17C 11/00, 1990 and French Application No. 2 331 485, Int. Cl. B31/10,
1977).
[0004] European Patent Application EP - A - 385773 discloses a gas storage and dispensing
system for the substantially reversible storage of a gas. Said gas storage and dispensing
system comprising a polymeric material having molecular microvoids occupiable by the
gas to cause the polymeric material to form a two-phase gas/solid reversible sorption
gas storage system which will tend to sorb increasing quantities of gas in increasing
ambient gas pressure, and tend to desorb previously sorbed gas with decreases in ambient
gas pressure. Gas, which comprises carbon dioxide, can be used as propellant. Besides
this, according to this document, a dispenser can comprise a semi-permeable barrier
enclosing the gas storage and dispensing system, the semi-permeable barrier being
permeable to propellant gas but substantially impermeable to the non-gaseous component
or components of gas storage and dispensing system whereby the semi-permeable barrier
passes the propellant gas to pressurise the product by direct contact while maintaining
the non-gaseous component or components of the gas storage and dispensing system out
of direct contact with the product. According to this document in variants, illustrated
in fig. 1 -4 the opportunity of use of absorption capacity of the atomized liquid
to provide decrease of the range of the change of initial and ultimate pressure in
the sealed package is not provided. Decrease of this range provides in its turn the
efficiency of quality of spraying in the proposed method.
[0005] Besides, as the mean of separation of sorbent and atomized substance an hydrophobic
membrane 460 (p. 15, line 13-25) is used. This membrane does not prevent penetration
of vapors of the atomized liquid through it in to the sorption system 30. Penetration
of vapors of the atomized liquid through the membrane, particularly aromatie substances
from the atomized deodorant liquid, will cause to rapid decrease of their quantity
in the composition of the atomized liquid. This result to worsen consumer capacity
(quality) of deodorant.
[0006] Besides, in the known method acetone is one of the elements in the composition of
the sorption system 30. Vapors of acetone can penetrate through a hydrophobic membrane
460 so that to change the composition of the atomized subtance, worsening consumer
capacity of the package.
[0007] French application No. 2331485 (Int. Cl. B65B31/10, 1977) discloses an aerosol package
in which an atomized product is located in a first chamber of the aerosol package,
a second chamber contains solid sorbent and propellant, the second chamber being provided
with a changing valve and means for passing propellant to the first chamber.
[0008] However, the known aerosol package does not provide the following factors:
first, means for separating a sorbent from volatile substances and/or vapors contained
in the atomized liquid. Particularly, gaseous aromatic agents of deodorants and medicines
can penetrate through a hydrophobic membrane to the chamber with a sorbent and be
sorbed. As the result, composition of the atomized liquid can change which is inadmissible
from the point of providing useful properties of the aerosol package. The same requirement
also refers to any valve means used to pass desorbed propellant from the second chamber
to the first chamber.
second, means for providing a constant quantity of a sorbent in the second chamber.
Failure to meet this requirement results in carrying away a portion of grains or activated
carbon by a propellant to the first chamber during discharge of a propellant from
the second chamber to the first chamber through valve means which causes unplanned
desorption of the propellant from the sorbent, i.e. a pressure rise inside the aerosol
package and deterioration of liquid spraying uniformity. Furthermore, tests proved
that particles of solid sorbent, in flow, can block up valve means and this will violate
the first requirement above. The conventional means for maintaining a constant quantity
of the solid sorbent are as follows:
- use of solid sorbent in a form of a firm monoblock;
- location of grained sorbent in an additional gas-tight shell;
- use of firm particles, the mean diameter thereof exceeding the diameter of an input
orifice in the valve means;
- mounting a gas-permeable filter at the input of valve means (said filter made, for
example, of foam plastic, wire net, cloth, etc).
third, using as a sorbent of the atomized liquid having lower absorption properties
with respect to propellant, than that of the solid sorbent, which provides for:
- improvement of atomizing owing to dispersing a propellant when atomizing liquid saturated
with the propellant;
- increase of extent of filling the aerosol package with the liquid to be atomized without
deterioration of spraying, owing to redistribution of the propellant between the chambers,
and thereby reducing the second chamber volume with respective increase of the first
chamber volume;
- improvement of the aerosol package operation safety at various weather conditions
in service (for example, from 0°C to 55°C), owing to reduction of the pressure inside
the aerosol package at heating thereof (thermal shocks) due to sorption by liquid
sorbent of the propellant overflown from the second chamber to the first one through
the valve means, which complies with the two requirements above.
[0009] FR-A-2596139 (Int. Cl. F17C5/00, 1987) discloses a method for charging an aerosol
package with a propellant, carbone dioxide. This technical solution, fails to provide
a separation of a sorbent from the atomized liquid. Lack of such separation results
in negative effects described above. Besides, in such package a valve can be blocked
with sorbent particles which leads to failure of the package as a whole.
[0010] GB-A-1322 942 (Int. Cl. F17C11/00, 1973), discloses a variant of an aerosol package
structure comprising separated liquid propellant and an atomized liquid, in which
spraying is accomplished by injection. This method of spraying is less economical,
because it requires extensive accommodation of propellant during usage of the package.
Furthermore, the structure does not exclude interaction of the atomized substance
with the ambient air inside the package, which is inadmissible in the aerosol packages
used for varnishes and paints, medicines and cosmetics.
[0011] Known in the art is the device for expelling substances from pressurized containers
(International Application PCT/EP90/0S842, publication WO 91/07620, Int.Cl. F17 C11/00,
1991).
[0012] The aforementioned application discloses an aerosol package structure comprising
separated propellant source and atomized liquid. The propellant is hydrogen in a form
of a hydride of an appropriate element, particularly, metal hydrides. Under the pressure
drop in a container with atomized liquid, hydrogen escapes through a valve 5 to a
cavity 4, maintaining pressure in a working space of the package. Metal hydrides are
chemical compounds in which hydrogen molecules form a chemical compound with metal.
Heat of metal hydride synthesis reactions is comparable with heat of chemical reactions
(10 - 100 kilocalories per mole). Heat of physical adsorption is 1 - 5 kilocalories
per mole for simple molecules. The aforementioned systems attain equilibrium at entirely
different pressure and temperature values. Particularly, for typical metal hydrides
MnNi
5 - H and FeTi - H indicated in the application as basic examples, dependence of equilibrium
dissociation pressure on temperature causes either a prohibitive pressure (over 1.5
Mpa) from safety point (package destruction) at the maximum working temperature 55°C,
as in the case of MnNi5 - H system, or insufficient pressure (below 0.3 Mpa) to provide
atomizing at working temperature 20°C and below, as in the case of some FeTi - H systems.
[0013] At the same time, high values of dissociation energy of metal hydrides result in
insufficient rates of hydrogen discharge (about 1% per min) which prevents to maintain
working pressure when the package is being emptied.
[0014] The specification of the cited prior art fails to mention that the atomized liquid
possesses absorption capacity.
[0015] Well known is a method of creation of positive pressure for gaseous carbone dioxide
(CO2) within the working cavity of aerosol package DE-A-36 25561, (Int. Cl. B65D 88/14,
1988). The method comprises the desorption of CO2, which is dissolved in sorbent,
i.e. the liquid to be atomized. The said method is based on creation of big quantity
of working gas above the level of liquid to be atomized and due to this in order to
increase the fullness of the package (i.e. amount of liquid to be atomized) it is
necessary to produce a package with bigger volume and thicker walls. In other words,
to increase its materials consumption. Whereas, according to this method, for increasing
the package fullness and decreasing nonuniformal flow rate of the substance to be
atomized, the working gas must be dissolved in the said substance. i.e. the atomized
substance must possess an absorption capacity for the working gas, that limits the
range of substances which can be atomized by means of this method.
Disclosure of the Invention
[0016] The main objective of the invention is to increase the efficiency of spraying due
to usage of volumetric dispersion effect, that is production of drops of smaller dimension
and maintaining of this increased degree of dispersion in the process of the aerosol
package usage, increased degree of the package charging with spraying product due
to decrease volume of the gas cushion of the propellant, extension of the product
and propellant range, which can be dispersed by this method.
[0017] The said objective is achieved according to claim 1 by the method of creation of
positive pressure in an aerosol package for spraying a gas-saturated product, including
placing a product containing a sorbent to be sprayed and gas sorbed in the sorbent
in the aerosol package, and by further providing inside the aerosol package a sealed
casing containing a nonspraying sorbent and gas sorbed therein and comprising means
for allowing gas desorbed from the nonspraying sorbent to release from the sealed
casing into the aerosol package when pressure inside the sealed casing exceeds pressure
outside the sealed casing at value of designated pressure differential, the nonspraying
sorbent being activated charcoal and/or zeolite having a higher absorption capacity
for gas than the sorbent to be sprayed, and preventing the sprayed sorbent and/or
its vapors from entering the sealed casing and the nonspraying sorbent from escaping
the sealed casing, thereby creating a positive pressure inside the aerosol package
for dispensing the gas-saturated product.
[0018] It is possible a variant where both activated carbon and zeolite are used as nonspraying
sorbent.
[0019] It is possible a variant where a solid phase of sorbed gas is used to charge said
nonspraying sorbent.
[0020] It is possible a variant where a liquid phase of sorbed gas is used to charge said
nonspraying sorbent.
[0021] It is possible a variant where the means for allowing desorbed gas out of the sealed
casing is a spring valve.
[0022] The said method of creation a positive pressure in an aerosol package decreases an
adverse effect on environment of the use of aerosol packages. Besides, fluctuations
of the positive pressure of desorpted gas in the gas cavity during the process of
spraying are relatively small due to the high sorption capacity of the working gas
in the unchangeable quantity of sorbent, that makes it possible to provide evenness
of the spraying substance, that is expecially important in varnish-dye covering.
[0023] Low values of the initial excess pressure of the sorbent gas and its excess pressure
reduction in the gas capacity of the working volume make it possible the increase
package filling degree of she spraying substance as well as package production economy
because of the material capacity reduction, for example, by means of the thin-walled
package usage.
[0024] The usage of sorption of the residual substances ( working gas, praying substances
) in sorbent decreases corrosion and other processes taking place in waste package,
i.e. makes it possible to decrease harmful waste into the atmosphere and waste package
influence upon the environment.
[0025] Package loading with sorbent gas, for example, with CO2 just in a solid phase makes
package loading operation easier.
[0026] Elimination of the interaction between spraying substance and sorbent while turning
over ( shaking, etc ) the package enlarges the quantity of the used sorbents.
[0027] It's also necessary to point out that this method enlarges the range of climate zones
of the usage and/or storage working range and aerosol package exloitation because
of the possibility of the sorbent usage with demanded characteristics.
[0028] In this method while operating a unit accordingly it is possible to have the dispersed
liquid temperature different from the sorbent and environment temperature that is
obtained by means of the dispersion of sorbent and spraying liquid as well as by means
of heat isolation and/or heat absorbtion characteristics of sorbent.
Brief Description of the Drawings
[0029] On the drawings:
- Figure 1
- is an illustration of a sorbent positioning at the periphery of the working volume
of the aerosol package.
- Figure 2
- is an illustration of a sorbent positioning in the inner case of the the aerosol package,
isolating sorbent from dispersed substance, as well as of the sorbent positioning
in the top part of the working volume above the dispersed liquid level.
Detailed Description
[0030] The given method can be realised in package for different substance dispersion (
spraying ). The construction of the aerosol unit is a sealed capacity 1, made as a
cylindrical case 2 ( referring Fig. 1 and Fig. 2 ) with a bottom 3 and a cover 4,
which is hermetically connected with a dispersion head 5 and a valve 6. As it is shown
in Figure 1 inside of the outer case 2 there is an inner casing 7 with a working volume
8, filled with dispersed substance 9 ( liquid ).
[0031] In the cavity 10 between the outer case 2 and the inner casing 7 there is an activated
charcoal ( it can be zeolite ) as a sorbent 11. At the top part of the inner casing
7 there are some holes 12 ( windows, etc. ) by the help of which the working volume
8 is communicated with the cavity 10. In the working volume 8 from its bottom up to
the top there is a tube 13 for delivery of the dispersed liquid 9 to the inlet of
the dispersion head 5. At the bottom 3 there is a charging valve 14 for the sorbent
and sorbent gas. As sorbent gas there can be used carbon dioxide ( CO2 ) highly used
in aerosol packages that answers ecological demands, put to sorbent gases of package,
as well as - hydrocarbons, ethers and etc. In Figure 2 there is shown another possible
positioning of the sorbent 11 inside the inner casing 7 of the package and/or at the
top part of the working volume 8 above the dispersed ( spraying ) liquid level 9.
It is also possible to position the sorbent 11 out of the outer case 2 of the package,
but in this case it must be put in a separate sealed cavity, communicating by means
of a supply main of the desorption gas with a gas cavity of the working volume ( it
is not shown in the drawing ). In the top part of the case 2 there is set a charging
valve 15 for a dispersed substance. Charging valves 14 and 15 can be set at any convenient
place on the outer case 2. The movement schemes of the desorption gas and dispersed
substance are shown by arrows in the drawing.
[0032] As the dispersed substance 9 there can be used different liquids, emulsions, suspensions
and fine- dispersed powders. In the latter case dispersed substance supply 9 is provided
by means of creating a pseudo-liquated layer by bringing desorption gas, desorpted
from the sorbent 11, at the moment of pressure lavering in the working volume 8 when
opening the valve 6 of the dispersion head 5.
[0033] The desorption gas can be brought to the working volume 8 as from the communicated
with the working volume cavity 10 where there is a sorbent 11, by the way, this cavity
can be got by a ring space between the inner casing 7, containing the dispersed substance
9, and the outer case 2 of the package ( see Fig. 1 ), and - from the sorbent 11,
situated just in the working volume 8 ( see Fig. 2 ). As energy supply, necessary
for gas desorption, from the package environment is carried out it is important to
provide a thermal contact between the outer case 2 of the package and the substance
of sorbent 11, which is enough for gas to exhaust with a sufficient speed, creating
dynamics of recovery of demanded pressure in the working volume 8 at the moment after
the package action that is to say immediately after the termination of a regular rate
of spraying.
[0034] Package filling is carried out by the dispersed substance 9 and sorbent 11 and then,
for example, by CO2, brought inside the cavity 10 with the sorbent either at a gas
state ( at a lower temperature and heat exhaust from the package ) or as liquid (
also at a low temperature, for example, about-73 C), or as a solid phase - in a state
of "dry ice".
[0035] In two latter variants ( see Fig. 2 ) it is not practically necessary to fulfill
heat exhaust from the package ( about 1.5 kJ/g CO2 ), because heat absorption takes
place in phase conversion of CO2 from a liquid or solid state to a sorption state.
[0036] Package filling is made taking into account, for example such quantity of CO2 supply
into the sorbent cavity which is possible to be absorpted in sorbent in given loading
conditions .
[0037] Sorbent volume in CO2 is determined in this case as by a sorbent type and by a demanded
pressure ( P ) of CO2 in the working volume at a given operation temperature ( for
example, 17 C ). For a typical value of the demanded pressure at a level of 0.15 MPa
the volume ( a ) of such sorbent as activated charcoal ( type AΓ) is about 33 g of
CO2 for 100 g of coal at a temperature ( t ) of 17 C. But taking into account possible
increasing of initial pressure in the package up to, for example, 0.2 MPa and/or operating
characteristics keeping while changing operating temperature in the given limits,
the initial rate of sorbent filling by CO2 is larger, i.e. it consists of 50 g of
CO2 for 100 g of sorbent.
[0038] Correlation of a and P at a constant temperature t is described by the sorption isotherm
equation by Freundlich (see Timofeev D.P. "Sorption Kinetics", M Publishing House
of the Academy of Sciences of the USSR, 1962, p.95-98 ).

where a - sorbent volume by the dissolved working gas in it. P - working gas pressure,K
and N - Freundlich constants, determined by the sorbent type.
[0039] Because of the fact that at the lower value of P of the working range and at the
residual value a the quantity of CO2 supplied during the operation time of the package,
must be sufficient for practically full displacement of the dispersed substance, it
means that when having CO2 density equal to 300 1/kg ( at the pressure of 0.15 MPa
and at t=17 C ), it is nessary to desorpt about 3 g of CO2 in order to displace 1
l of the dispersed liquid. Having difference of the initial and final volume of a
of CO2 equal to 50-35=15 g per 100 g sorbent, it means that the quantity of sorbent
must be not less than 30 g. Having filling density of sorbent at the level of 600
g/l, the volume, filled with sorbent, must not be less than 0.05 l.
[0040] Everything described above refers to the offered technical decision when the whole
initial volume of sorbent is used for its supplement to the working volume. It means
that there must be provided stable conditions of conservation of the sorbent quantity
during operation time and, of course, - necessary heat supply to the whole volume
of it ( sorbent ).
[0041] It stands to reason, that when spraying fine-dispersed powders, as it was described
above, some quantity of CO2 will escape from the package at the time of powder moving
to the spraying zone and to the package environment and this fact will demand usage
of more specific quantities of sorbent than these given above.
[0042] In order to prevent correlations ( for example, when the package is turned over )
of the dispersed substance 9 and sorbent 11, when such a combination of them is used
that the said correlation can provide an undesirable change of their characteristics,
working gas supply from the cavity 10 with the sorbent 11 to the working volume 8
( see Fig. 1 ) is fulfilled only when some given differential pressure between these
spaces is obtained, that can be fulfilled by means of the work of the spring valve
( as the work of the valve 6 of the dispersion head 5 ), which opens the inlet of
the working gas from volume 8 only at a lower pressure in the working volume ( for
example, on the state of sraying ) and/or at an increased pressure in the cavity 10
of sorbent ( for example, at temperature increasing in this cavity ).
[0043] An important quality of the usage of sorbent with an absorption capability higher
in comparison with that of the dispersed substance, is an opporunity to prevent a
package working gas ( after the operation usage of this package ) escapement into
the environment, for example, when the case is damaged ( because, in particular, of
corrosion ). This opportunity is obtained by means of the environment temperature
decreasing, for example, when transporting utilised package into cold climate zones.
When necessary it is even possible to organize a processing treatment of utilised
package in such a way that when package opening takes place, the temperature decreases
up to the value, when the considerable part ( up to 80-90 % ) of the working gas is
again sorpted in sorbent and that's why can be used again as well as sorbent itself.
[0044] The demanded decreasing of the temperature is determined by the following dependence
( see: Stolyarevskii A.Y. "Secondary Energy Accumulation" in the Collection "Atomic
- Hydrogen Energetics and Technology", edition 4, M. Energy - Edition, 1982, p. 95
):

where A and B - are parameters of the given sorbent, P - residual pressure of the
unsorpted gas.
[0045] According to the invention as sorbent there can be used activated charcoal, characterised
by a rather high absorption capability as for as CO2 is concerned and relatively low
price, as well as zeolite, the characteristics of which can provide higher pressure
P at a given working temperature.
[0046] Finding of grade and/or combination of different sorbent types among activated charcoal
and/or zeolite ( for example, charcoal + zeolite) permits to optimise operation condition.
[0047] For convenient loading of the package there can be used liquid sorbents as well as
in combination with solid ones in the state of which there can be used some organic
combinations, in particular, dimethylethertetraethylenealcohol or halogenides.
1. Verfahren zur Erzeugung eines Überdrucks in einer Aerosol-Verpackung (1), um ein mit
Gas gesättigtes Produkt zu versprühen, wobei das Verfahren das Anordnen eines Produkts,
das ein Sorptionsmittel (9), das versprüht werden soll, sowie ein Gas enthält, das
im Sorptionsmittel in der Aerosol-Verpackung sorbiert ist, dadurch gekennzeichnet,
dass das Verfahren weiters in der Aerosol-Verpackung einen abgedichteten Behälter
(10) vorsieht, der ein nicht zu versprühendes Sorptionsmittel (11) sowie ein darin
sorbiertes Gas enthält und eine Einrichtung (12) besitzt, damit das vom nicht zu versprühenden
Sorptionsmittel (11) desorbierte Gas vom abgedichteten Behälter in die Aerosol-Verpackung
(1) freigegeben werden kann, wenn der Druck im abgedichteten Behälter (10) den Druck
außerhalb des abgedichteten Behälters (10) um den Wert eines festgelegten Druckgefälles
überschreitet, wobei das nicht zu versprühende Sorptionsmittel (11) Aktivkohle und/oder
Zeolith ist, die ein höheres Absorptionsvermögen für Gas als das zu versprühende Sorptionsmittel
(9) besitzen, wobei verhindert wird, dass das versprühte Sorptionsmittel und/oder
dessen Dämpfe in den abgedichteten Behälter (10) eindringen und das nicht zu versprühende
Sorptionsmittel (11) aus dem abgedichteten Behälter (10) austritt, wodurch in der
Aerosol-Verpackung (1) ein Überdruck erzeugt wird, um das mit Gas gesättigte Produkt
abzugeben.
2. Verfahren gemäß Anspruch 1, wobei als nicht zu versprühendes Sorptionsmittel (11)
sowohl Aktivkohle als auch Zeolith verwendet werden.
3. Verfahren gemäß Anspruch 1, wobei eine feste Phase eines sorbierten Gases verwendet
wird, um das nicht zu versprühende Sorptionsmittel (11) aufzuladen.
4. Verfahren gemäß Anspruch 1, wobei eine flüssige Phase eines sorbierten Gases verwendet
wird, um das nicht zu versprühende Sorptionsmittel (11) aufzuladen.
5. Verfahren gemäß Anspruch 1, wobei die Einrichtung, durch die das desorbierte Gas aus
dem abgedichteten Behälter (10) austreten kann, ein federbelastetes Rückschlagventil
ist.