U.S. patent application number 12/688986 was filed with the patent office on 2011-07-21 for deformation-resistant plastic aerosol container.
This patent application is currently assigned to GRAHAM PACKAGING COMPANY, L.P.. Invention is credited to Stephen R. Guerin, Tapan Y. Patel.
Application Number | 20110174765 12/688986 |
Document ID | / |
Family ID | 44003335 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110174765 |
Kind Code |
A1 |
Patel; Tapan Y. ; et
al. |
July 21, 2011 |
Deformation-Resistant Plastic Aerosol Container
Abstract
A plastic aerosol container includes a plastic base portion and
a plastic main body portion that is unitary with the plastic base
portion and defines a longitudinal axis. The base portion and the
main body portion together define an internal space within the
container that is pressurized with an aerosol mixture at a pressure
that is substantially within a range of about 50 psi to about 300
psi at room temperature. The main body portion has an upper portion
that has a first maximum transverse diameter, a lower portion that
has a second maximum transverse diameter and an intermediate
portion that has a third maximum transverse diameter. The third
minimum transverse diameter is less than both the first and second
maximum transverse diameters, whereby the main body portion has a
narrowed waist portion that provides reinforcement against
deformation as a result of pressurization within the internal space
of the container. The narrowed waist portion preferably has a
substantially constant radius of curvature.
Inventors: |
Patel; Tapan Y.; (Nashua,
NH) ; Guerin; Stephen R.; (Milford, NH) |
Assignee: |
GRAHAM PACKAGING COMPANY,
L.P.
York
PA
|
Family ID: |
44003335 |
Appl. No.: |
12/688986 |
Filed: |
January 18, 2010 |
Current U.S.
Class: |
215/382 |
Current CPC
Class: |
B65D 83/44 20130101;
B65D 1/0223 20130101; B65D 83/38 20130101; B65D 1/0276
20130101 |
Class at
Publication: |
215/382 |
International
Class: |
B65D 90/02 20060101
B65D090/02 |
Claims
1. A plastic aerosol container, comprising: a plastic base portion;
and a plastic main body portion that is unitary with the plastic
base portion and that defines a longitudinal axis, the base portion
and the main body portion together defining an internal space
within the container, and wherein the main body portion has an
upper portion that has a first maximum transverse diameter, a lower
portion that has a second maximum transverse diameter and an
intermediate portion that has a third maximum transverse diameter,
and wherein the third minimum transverse diameter is less than both
the first and second maximum transverse diameters, whereby the main
body portion has a narrowed waist portion that provides
reinforcement against deformation as a result of pressurization
within the internal space of the container.
2. A plastic aerosol container according to claim 1, wherein the
internal space of the container is pressurized with an aerosol
mixture to a pressure that is substantially within a range of about
50 psi to about 300 psi.
3. A plastic aerosol container according to claim 1, wherein the
second maximum transverse diameter is substantially the same as the
first maximum transverse diameter.
4. A plastic aerosol container according to claim 1, wherein one of
said first and second maximum transverse diameters represents a
maximum transverse diameter of the container.
5. A plastic aerosol container according to claim 4, wherein a
ratio of the third minimum transverse diameter to the maximum
transverse diameter of the container is substantially within a
range of about 0.50 to about 0.95.
6. A plastic aerosol container according to claim 5, wherein the
ratio of the third minimum transverse diameter to the maximum
transverse diameter of the container is substantially within a
range of about 0.65 to about 0.95.
7. A plastic aerosol container according to claim 6, wherein the
ratio of the third minimum transverse diameter to the maximum
transverse diameter of the container is substantially within a
range of about 0.80 to about 0.95.
8. A plastic aerosol container according to claim 1, wherein the
narrowed waist portion is substantially symmetrical about the
longitudinal axis.
9. A plastic aerosol container according to claim 1, wherein the
narrowed waist portion has an outer surface that is concavely
curved when viewed in a longitudinal cross-section.
10. A plastic aerosol container according to claim 9, wherein said
concavely curved outer surface of the narrowed waist portion has a
substantially constant radius of curvature.
11. A plastic aerosol container according to claim 10, wherein a
ratio of the substantially constant radius of curvature to the
third minimum transverse diameter is substantially within a range
of about 2.0 to about 7.0.
12. A plastic aerosol container according to claim 11, wherein the
ratio of the substantially constant radius of curvature to the
third minimum transverse diameter is substantially within a range
of about 3.0 to about 6.0.
13. A plastic aerosol container according to claim 12, wherein the
ratio of the substantially constant radius of curvature to the
third minimum transverse diameter is substantially within a range
of about 3.75 to about 5.0.
14. A plastic aerosol container according to claim 1, wherein said
base portion and said main body portion are fabricated from
polyethylene terephthalate using a blow molding process.
15. A plastic aerosol container according to claim 1, wherein said
main body portion is substantially symmetrical about the
longitudinal axis.
16. A plastic aerosol container according to claim 1, wherein said
base portion and said main body portion are fabricated from a high
intrinsic viscosity polyethylene terephthalate material.
17. A plastic aerosol container according to claim 16, wherein said
high intrinsic viscosity polyethylene terephthalate material has an
intrinsic viscosity that is substantially within a range of about
0.80 to about 0.95.
18. A plastic aerosol container, comprising: a plastic base
portion; and a plastic main body portion that is unitary with the
plastic base portion and that defines a longitudinal axis, the base
portion and the main body portion together defining an internal
space within the container; and wherein the main body portion has
an upper portion that has a first maximum transverse diameter, a
lower portion that has a second maximum transverse diameter and an
intermediate portion that has a third maximum transverse diameter,
and wherein the third minimum transverse diameter is less than both
the first and second maximum transverse diameters, whereby the main
body portion has a narrowed waist portion that provides
reinforcement against deformation as a result of pressurization
within the internal space of the container, said narrowed waist
portion having a substantially constant radius of curvature; and
the internal space of the container is pressurized with an aerosol
mixture to a pressure that is substantially within a range of about
50 psi to about 300 psi.
19. A plastic aerosol container according to claim 18, wherein a
ratio of the third minimum transverse diameter to the maximum
transverse diameter of the container is substantially within a
range of about 0.50 to about 0.95.
20. A plastic aerosol container according to claim 18, wherein a
ratio of the substantially constant radius of curvature to the
third minimum transverse diameter is substantially within a range
of about 2.0 to about 7.0.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates broadly to the field of containers
that are adapted to hold highly pressurized contents, such as
aerosol mixtures, and more particularly to a plastic aerosol
container having a sidewall construction that is adapted to offer
maximum resistance to deformation at high internal pressures.
[0003] 2. Description of the Related Technology
[0004] Aerosol containers have conventionally been fabricated from
metal, and are conventionally formed as a cylindrical tube having
upper and lower end closures. The bottom end closure is typically
shaped as a concave dome, and the upper end closure typically
includes a manually actuatable valve for dispensing the pressurized
aerosol contents of the container.
[0005] Metallic containers have certain inherent disadvantages,
such as a tendency to rust over time and to scratch surfaces with
which they may come into contact.
[0006] Efforts have been made in the past to develop plastic
aerosol containers, but have encountered difficulties, mainly
relating to controlling the deformation of the plastic material as
a result of the significant internal pressurization that is
necessary in an aerosol container. Aerosol containers commonly
require internal pressures of the magnitude of 50-300 psi, which is
significantly greater than pressures that are typically encountered
in other packaging applications for which plastic material has been
used, such as the packaging of carbonated beverages. Accordingly,
design considerations for plastic aerosol containers are quite
different than they are for lower pressure packaging applications
such as plastic beverage containers.
[0007] A plastic aerosol container ideally should be constructed to
minimize expansion of the sidewall when it is fully pressurized. If
the sidewall is permitted to expand a significant amount, the
container is difficult to convey during the manufacturing process,
difficult to package in bulk quantities and is space inefficient in
a retail facility. If significant deformation occurs in the base
portion of the container, it may be unable to effectively support
the container on a horizontal surface, both in the retail facility
and in the household.
[0008] A need therefore exists for an improved plastic aerosol
container having a sidewall configuration that is constructed to
offer maximum resistance to deformation at high internal
pressures.
SUMMARY OF THE INVENTION
[0009] Accordingly, it is an object of the invention to provide an
improved plastic aerosol container having a sidewall configuration
that is constructed to offer maximum resistance to deformation at
high internal pressures.
[0010] In order to achieve the above and other objects of the
invention, a plastic aerosol container that is constructed
according to a first aspect of the invention includes a plastic
base portion; and a plastic main body portion that is unitary with
the plastic base portion and that defines a longitudinal axis. The
base portion and the main body portion together define an internal
space within the container. The main body portion has an upper
portion that has a first maximum transverse diameter, a lower
portion that has a second maximum transverse diameter and an
intermediate portion that has a third maximum transverse diameter.
The third minimum transverse diameter is less than both the first
and second maximum transverse diameters, whereby the main body
portion has a narrowed waist portion that provides reinforcement
against deformation as a result of pressurization within the
internal space of the container.
[0011] A plastic aerosol container according to a second aspect of
the invention includes a plastic base portion and a plastic main
body portion that is unitary with the plastic base portion and
defines a longitudinal axis. The base portion and the main body
portion together define an internal space within the container that
is pressurized with an aerosol mixture at a pressure that is
substantially within a range of about 50 psi to about 300 psi. The
main body portion has an upper portion that has a first maximum
transverse diameter, a lower portion that has a second maximum
transverse diameter and an intermediate portion that has a third
maximum transverse diameter. The third minimum transverse diameter
is less than both the first and second maximum transverse
diameters, whereby the main body portion has a narrowed waist
portion that provides reinforcement against deformation as a result
of pressurization within the internal space of the container. The
narrowed waist portion preferably has a substantially constant
radius of curvature.
[0012] These and various other advantages and features of novelty
that characterize the invention are pointed out with particularity
in the claims annexed hereto and forming a part hereof. However,
for a better understanding of the invention, its advantages, and
the objects obtained by its use, reference should be made to the
drawings which form a further part hereof, and to the accompanying
descriptive matter, in which there is illustrated and described a
preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a side elevational view of a plastic aerosol
container that is constructed according to a preferred embodiment
of the invention;
[0014] FIG. 2 is a bottom plan view of the plastic aerosol
container that is shown in FIG. 1;
[0015] FIG. 3 is a diagrammatical cross-sectional view taken along
lines 3-3 in FIG. 2;
[0016] FIG. 4 is a cross-sectional view of an aerosol valve
assembly for the plastic aerosol container that is depicted in FIG.
1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0017] Referring now to the drawings, wherein like reference
numerals designate corresponding structure throughout the views,
and referring in particular to FIG. 1, a plastic aerosol container
10 that is constructed according to a preferred embodiment of the
invention is preferably fabricated from a plastic material such as
polyethylene terephthalate (PET), polyethylene naphthalate (PEN),
polyamide (Nylon), or a blend containing some combination of the
same from a plastic preform using a conventional blow molding
process such as the reheat stretch blow molding process.
[0018] Plastic aerosol container 10 includes a main body portion 12
having a thin oriented sidewall 14, a finish portion 16 that is
coupled in a pressure-resistant manner to the aerosol valve
assembly 40 that is shown in FIG. 4, and a base portion 18 that is
adapted to support the plastic aerosol container 10 on an
underlying flat horizontal surface such as a retail shelf or a
shelf in a business or household.
[0019] The main body portion 12 defines a longitudinal axis 20, and
is preferably shaped so that it is substantially symmetrical about
the longitudinal axis 20. The main body portion 12, base portion 18
and finish portion 16 together define an internal space 22 for
holding a pressurized aerosol mixture 31, preferably at a high
pressure that is substantially within a range of about 50 psi to
about 300 psi at room temperature, and more preferably
substantially within a range of about 100 psi to about 300 psi at
room temperature. Room temperature for purposes of this document is
defined as a range that is substantially between about 63 degrees
F. to about 77 degrees F.
[0020] The aerosol mixture 31 preferably includes a propellant,
which could be a liquefied gas propellant or a compressed or
soluble gas propellant. Liquefied gas propellants that could be
used include hydrocarbon propellants such as propane, isobutene,
normal butane, isopentane, normal pentane and dimethyl ether, and
hydrofluorocarbon propellants such as difluoroethane (HFC-152a) and
tetrafluoroethane (HFC-134a). Compressed and soluble gas
propellants that could be used include carbon dioxide (C02),
nitrous oxide (N20), nitrogen (N2) and compressed air.
[0021] The main body portion 12, the finish portion 16 and the base
portion 18 are preferably unitary with each other and in the
preferred embodiment are fabricated from a high intrinsic viscosity
polyethylene terephthalate material, which most preferably has an
intrinsic viscosity that is substantially within a range of about
0.80 to about 0.95.
[0022] Referring now to FIGS. 1 and 3, it will be seen that the
main body portion 12 has an upper portion 28 having a first maximum
transverse diameter D.sub.1, a lower portion 30 having a second
maximum transverse diameter D.sub.2 and an intermediate portion 32
positioned between the upper and lower portions 28, 30 having a
third minimum transverse diameter D.sub.3 that is less than both
the first and second maximum transverse diameters D.sub.1, D.sub.2.
Accordingly, the intermediate portion 32 defines a narrowed waist
portion that provides reinforcement against deformation as a result
of the pressurization within the internal space of the plastic
aerosol container 10. The narrowed waist portion is preferably
shaped so that it is substantially symmetrical about the
longitudinal axis 20.
[0023] The upper portion 28 and the lower portion 30 are preferably
generally cylindrical in shape, having a flat vertically-oriented
sidewall portion as viewed in longitudinal cross-section, which
facilitates handling at the production and filling facility.
[0024] In the preferred embodiment, the upper and lower portions
28, 30 are shaped so that the first and second maximum transverse
diameters D.sub.1, D.sub.2 are substantially equal, and together
define a maximum transverse diameter D.sub.MAX for the entire main
body portion 12 and the entire plastic aerosol container 10.
[0025] Preferably, a ratio of the third minimum transverse diameter
D.sub.3 to the maximum transverse diameter of the container
D.sub.MAX is substantially within a range of about 0.50 to about
0.95, more preferably substantially within a range of about 0.65 to
about 0.95 and most preferably substantially within a range of
about 0.80 to about 0.95.
[0026] The narrowed waist portion is preferably shaped to have an
outer surface that is concavely curved when viewed in a
longitudinal cross-section, as is shown in FIG. 3. The concavely
curved outer surface of the narrowed waist portion moreover
preferably has a substantially constant radius of curvature
R.sub.C. A ratio of the substantially constant radius of curvature
R.sub.C to the third minimum transverse diameter D.sub.3 is
preferably substantially within a range of about 2.0 to about 7.0,
more preferably substantially within a range of about 3.0 to about
6.0, and most preferably substantially within a range of about 3.75
to about 5.0.
[0027] The aerosol valve assembly 40 is sealed to the finish
portion 16 by a crimped flange 54. Aerosol valve assembly 40
includes a dip tube 42 that is positioned within the internal space
22 of the container 10, and a main body portion 44. A valve stem 46
is biased towards a closed position with respect to the main body
portion 44 by means of a spring 48. In the closed position, an
orifice 50 is sealed by a gasket 52 so that no product from the
internal space 22 is expelled under pressure through the internal
passage 56 that is defined within the valve stem 46.
[0028] An additional conventional dispensing and directing cap may
be mounted in the valve stem 46. When the valve stem 46 is
depressed, the orifice 50 is opened and product from the internal
space 22 is expelled under pressure through the internal passage 56
and through the dispensing and directing cap as an aerosol
spray.
[0029] It is to be understood, however, that even though numerous
characteristics and advantages of the present invention have been
set forth in the foregoing description, together with details of
the structure and function of the invention, the disclosure is
illustrative only, and changes may be made in detail, especially in
matters of shape, size and arrangement of parts within the
principles of the invention to the full extent indicated by the
broad general meaning of the terms in which the appended claims are
expressed.
* * * * *