U.S. patent application number 12/530688 was filed with the patent office on 2010-05-06 for aerosol for viscous products.
This patent application is currently assigned to Crown Packaging Technology, Inc.. Invention is credited to John Pawel Bilko.
Application Number | 20100108716 12/530688 |
Document ID | / |
Family ID | 37988892 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100108716 |
Kind Code |
A1 |
Bilko; John Pawel |
May 6, 2010 |
AEROSOL FOR VISCOUS PRODUCTS
Abstract
An aerosol dispensing container 1 comprising a container body
20, 30, 40 and a collapsible bag 50 therein. The bag 50 separates a
pressurised chamber defined between the container body 20, 30, 40
and the bag 50 from a product chamber defined inside the bag 50. A
valve 5 is mounted in a valve cup 70 supported by the body 20, 30,
40 and the valve arrangement allows fluid communication between the
valve 5 and the product chamber inside the bag 50. An extrinsic
support means 54, 55 is carried by the bag 50 and is adapted to
ensure flow of product to the valve 5 by preventing radial collapse
of the bag 50, whilst allowing axial collapse of the bag 50 as the
product is dispensed.
Inventors: |
Bilko; John Pawel;
(Wiltshire, GB) |
Correspondence
Address: |
WOODCOCK WASHBURN LLP
CIRA CENTRE, 12TH FLOOR, 2929 ARCH STREET
PHILADELPHIA
PA
19104-2891
US
|
Assignee: |
Crown Packaging Technology,
Inc.
Alsip
IL
|
Family ID: |
37988892 |
Appl. No.: |
12/530688 |
Filed: |
March 13, 2008 |
PCT Filed: |
March 13, 2008 |
PCT NO: |
PCT/EP2008/053013 |
371 Date: |
September 10, 2009 |
Current U.S.
Class: |
222/95 ; 222/105;
222/386.5; 222/387; 222/389; 222/394 |
Current CPC
Class: |
B65D 83/62 20130101 |
Class at
Publication: |
222/95 ; 222/394;
222/386.5; 222/389; 222/387; 222/105 |
International
Class: |
B65D 35/28 20060101
B65D035/28; B65D 83/00 20060101 B65D083/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 13, 2007 |
GB |
0704821.8 |
Claims
1. An aerosol container for dispensing a product, comprising: a
container body, a collapsible bag disposed therein in the container
body, a pressurized chamber defined between the container body and
the bag, a product chamber defined inside the bag, a valve carried
in a valve cup, the valve arranged in fluid communication with the
product chamber, the bag including extrinsic support structure
adapted to prevent radial collapse of the bag to maintain the flow
of product to the valve, whilst while allowing axial collapse of
the bag as the product is dispensed.
2. An aerosol container according to claim 1, wherein the support
structure means comprises a cage or spring.
3. An aerosol container according to claim 2, wherein the spring is
disposed within the bag.
4. An aerosol container according to claim 1, wherein the support
structure comprises one or more circumferential or helical ribs
carried by the bag.
5. An aerosol container according to claim 4, wherein the ribs are
carried on the outside of the bag.
6. An aerosol container according to claim 4, wherein the ribs are
located within the wall thickness of the bag.
7. An aerosol container according to claim 4, wherein the ribs are
discontinuous.
8. An aerosol container according to claim 4, wherein the ribs and
the intervening sidewall of the bag are arranged to define a
bellows structure.
9. An aerosol container according claim 1 wherein the support
structure means is made from a material that is compatible with the
product.
10. An aerosol container according claim 1, wherein the support
structure is a cage.
11. An aerosol container according claim 10, wherein the cage is
disposed within the bag.
Description
TECHNICAL FIELD
[0001] The present invention relates to aerosol containers
comprising an outer casing with a bag for product encapsulated
therein. Such containers are commonly referred to in the art as
bag-in-can aerosols.
[0002] In particular, the invention relates to adaptation of such
bag-in-can systems to allow expulsion of viscous products, for
example in the form of pastes or thick gels. Such products may
include adhesives, sealants and fillers.
BACKGROUND ART
[0003] Bag-in can aerosol dispensers have been known from the prior
art since the 1960's. For example, GB 1030596 (ALLIED CHEM) May 22,
1966 describes the manufacturing method used for production of a
nylon bag and its incorporation into such an aerosol container.
[0004] In later years, such systems were enhanced to provide
various improvements to the bag structure and dispensing
characteristics. For example, U.S. Pat. No. 3,539,083 (DART IND
INC) Nov. 10, 1970 describes modification of the bag and can
structure to ensure that the bag cavity fills the can and also the
incorporation of a dip tube inside the bag to ensure that when the
valve is opened, product being dispensed from the container does
not itself throttle further product dispensing. U.S. Pat. No.
4,148,416 (METAL BOX CO LTD) Oct. 4, 1979 describes a loose core
member within the bag, which prevents the formation of "pockets"
within the product as the bag collapses and product is
dispensed.
[0005] Whilst the disclosure in the prior art is suitable for many
products, such aerosols are now being proposed for more
challenging, viscous products. The viscosity of the products now
being considered for such bag-in-can technology exacerbates the
problems of throttling the product flow from the aerosol valve and
the uneven or even lack of dispensing of some product from the
container.
[0006] Where a product is very thick the bag-in-can system will
tend to dispense the product nearest the valve adequately. However,
as product is dispensed the bag tends to collapse near the valve,
sealing the path between the remaining product and the valve. Thus,
it becomes very difficult or impossible to expel some of the
product, which remains trapped within the aerosol container. The
viscosity of the product means that the use of a dip tub is
impractical and a free-floating core will not provide a flow path
necessary to dispense the product.
[0007] Historically, bags with pleats or folds created using only
the material of the bag sidewall, "pleated bags", have been a
popular way of trying to control the collapsing of the product bag.
The bags are typically made from a plastics material and are shaped
using conventional blow-moulding techniques to introduce folds or
pleats in the bag sidewall. These folds or pleats are usually `V`
or `U`-shaped in transverse cross-section and generally have a
decreasing sidewall thickness as the diameter of the bag increases
from its pre-shaped form due to stretching of the material. Their
effect is to introduce an annular or circumferential weakening or
bands in the bag, which permits the bag to collapse under applied
forces. U.S. Pat. No. 3,471,059 A (J. L. MOLLER ET AL) Oct. 7, 1969
describes a dispensing container with such a pleated bag. The bag
is formed from an integral piece of material and includes axially
spaced primary fold sections and secondary fold bands collapsible
subsequent to the collapse of the primary fold sections. The
intention of the paneling is to regulate the collapse of the bag
caused by the pressure forces acting on it radially and axially as
product is dispensed. U.S. Pat. No. 4,062,475 A (HARRIS AND MONSON)
Dec. 13, 1977 also describes in one particular embodiment a bag
(flexible liner, 9) with horizontally pleated sides. Again, the
Figures of U.S. Pat. No. 4,056,213 A (MARTIN PAINT) Nov. 1, 1977
show a pleated bag with the pleats or folds forming a collapsible
bellows or piston. In GB 1116423 A (CONTINENTAL CAN) Feb. 28, 1967
such folds are used both to rigidify the bag (circumferentially
extending first means, 25) and to regulate the collapse of the bag
(circumferentially extending second means, 26). In practice however
a pleated collapsible bag does not work very well; the inventor has
found that pleated bags are prone to collapsing inwardly radially
despite the teachings of Moller, Harris, Martin Paint and
Continental Can. The decreasing bag sidewall thickness of the
pleats or folds is insufficient, especially in combination with
highly viscous products, to withstand the pressure of the
propellants used these days and pleated bags still tend to collapse
uncontrollably resulting in undispensed product. There remains the
need to provide a strong product bag which will collapse
predictably under the applied influence of propellant and the
inventor has found that only extrinsic support means, i.e. those
added to the bag, as opposed to intrinsic support means which are
made out of the bag material such as folds or pleats, will
suffice.
DISCLOSURE OF INVENTION
[0008] Accordingly, the present invention provides an aerosol
dispensing container comprising a container body and a collapsible
bag therein to separate a pressurised chamber defined between the
container body and the bag from a product chamber defined by the
bag, and an actuating valve carried by the container body and
arranged in fluid communication with the product chamber,
characterised in that the bag includes extrinsic support means
adapted to prevent radial collapse of the bag to maintain flow of
product to the valve whilst allowing axial collapse of the bag as
the product is dispensed.
[0009] As product is dispensed from the aerosol container, the bag
tends to collapse radially, but the support means keeps the walls
of the bag at a defined distance, preventing further radial
collapse and defining a flow path for the remaining product to the
aerosol valve.
[0010] The inventor has used both a cage-like structure and
subsequently a conventional spring as the support means with
similar results. The cage or spring is preferably located inside
the bag and it is therefore submerged in the product. Therefore,
the material from which the cage or spring is made must be chosen
carefully. The cage or spring must not be adversely affected by the
product (e.g. it must not corrode) and neither must it adversely
affect the product (e.g. by chemical reaction). The cage or spring
should also be arranged so that it does not inhibit or prevent the
flow of product to the actuating valve.
BRIEF DESCRIPTION OF FIGURES IN THE DRAWINGS
[0011] Different embodiments of the present invention will now be
described, by way of example only, with reference to the
accompanying drawings, in which:
[0012] FIG. 1 shows a cut away isometric drawing of a prior art
aerosol container with bag and an expanded area of the top section
of this container.
[0013] FIG. 2 shows a cross section view through an aerosol
container according to the invention with a helical spring located
inside the bag.
[0014] FIG. 3 shows a cross section through the same aerosol
container as that shown in FIG. 2, after the contents of the bag
has been dispensed and the helical spring is compressed.
[0015] FIG. 4 shows a cross section view through an aerosol
container according to a second embodiment of the invention where
ribs are situated within the product compartment and are adapted to
define a bellows structure, which prevents radial collapse of the
bag, whilst allowing axial compression of the bag.
[0016] FIG. 5 shows a cross section view through an aerosol
container according to another embodiment of the invention, in
which the bag sidewall incorporates ribs designed to prevent radial
collapse of the bag, whilst allowing axial compression of the
bag.
[0017] Referring to FIG. 1, a prior art aerosol container 1
comprises a body 30 having a base 20 and a cone 40. The free edge
of the cone 40 is finished with a curl 42. The base 20 and cone 40
are connected to the body 30 using conventional joining methods,
such as a double seam. The base 20 defines a charging port or
aperture 25, through which propellant is inserted into the aerosol
container 1, the propellant being used to drive any product in the
aerosol container 1 out of the valve 5, when it is opened. The
propellant may either take the form of a liquidified propellant or
a compressed gas.
[0018] The aerosol container 1 shown in FIG. 1 is a conventional
"bag in can" aerosol. A bag 50 is inserted into the body 30. The
inside of the bag 50 defines a product compartment and the space
left outside the bag 50, between the bag 50 and the body 30,
defines a propellant compartment into which propellant is
introduced via the charging port 25. Once propellant has been
inserted into the propellant compartment, the charging port 25 is
sealed with a grommet 26.
[0019] FIG. 2 illustrates a first embodiment of the invention, in
which a spring 54 is inserted into the neck 57 of the bag 50 in the
vicinity of the valve 5. The valve 5 is mounted in a valve cup 70
and is arranged in fluid communication with the product compartment
inside the bag 50. The spring 54 is arranged to brace the sidewall
53 of the bag against radial collapse, whilst allowing the base 52
of the bag to collapse axially.
[0020] FIG. 3 illustrates the same embodiment of the invention as
FIG. 2, but this figure shows the spring 54 in its compressed
configuration. As product is forced out of the valve 5, by the
propellant acting on the bag 50, the spring 54 braces the bag 50
and prevents radial collapse. This ensures that the flow path of
product to the valve 5 is maintained. As product is used up the
spring 54 compresses axially, ensuring that most of the product is
dispensed from the bag 50 through the valve 5.
[0021] A disadvantage of this arrangement is that the spring 54 is
submerged in the product inside the bag 50. This may cause the
spring 54 to become "clogged" by the product, thus restricting its
effective operation. In order to overcome this problem, the spring
54 may need to be made of more expensive materials (such as
stainless steel), which is uneconomic for many aerosol
applications. Spring materials that are inert in the presence of a
wide variety of products are prohibitively expensive, often costing
many times the cost of the finished aerosol product on the
supermarket shelf.
[0022] To avoid "clogging" of the spring, the inventor has designed
an alternative bag arrangement (as shown in FIG. 4), in which ribs
55 are provided around the circumference of the bag 50 in fluid
communication with the product compartment, the sidewall 53 in
between the ribs 55 acting as a flexible web. The ribs 55 and the
flexible sidewall 53 therebetween form a bellows structure. The
ribs 55 are adapted to prevent radial collapse of the bag 50 whilst
the bellows structure allows axial compression of the bag 50. The
ribs 55 can be of any cross-section, for example, hexagonal, but
preferably they have a circular cross-section. A disadvantage of
this bellows structure is that it is difficult to manufacture and
makes assembly of the bag 50 inside the aerosol body 30
complex.
[0023] FIG. 5 shows a third embodiment of the invention, which
requires no spring or like component inside the bag 50 and no ribs
55, which are difficult to assemble inside the aerosol body 30. In
this embodiment of the invention, one or more ribs 55 are provided
integrally with the sidewall 53 of the bag 50. The ribs 55 may be
arranged to form a helix or may be provided as segments of a helix,
i.e. they may be continuous or discontinuous. The ribs 55 are
designed and arranged to restrict radial collapse of the bag 50,
whilst allowing axial compression of the bag 50 in much the same
way as the spring 54 (shown in FIGS. 2 and 3) and the ribs 55 shown
in FIG. 4.
* * * * *