U.S. patent application number 16/251670 was filed with the patent office on 2019-05-23 for method of making an aerosol container.
This patent application is currently assigned to GRAHAM PACKAGING COMPANY, L.P.. The applicant listed for this patent is GRAHAM PACKAGING COMPANY, L.P.. Invention is credited to Stephen R. Guerin, Thomas E. Nahill, Tapan Y. Patel, JR..
Application Number | 20190152683 16/251670 |
Document ID | / |
Family ID | 45541081 |
Filed Date | 2019-05-23 |
United States Patent
Application |
20190152683 |
Kind Code |
A1 |
Patel, JR.; Tapan Y. ; et
al. |
May 23, 2019 |
METHOD OF MAKING AN AEROSOL CONTAINER
Abstract
An aerosol container includes a main body portion that is
constructed and arranged to withstand aerosol pressurization within
a range that is about 90-180 prig and a threaded finish portion
that is unitary with the main body portion. The threaded finish
portion has at least one helical thread, a support ledge beneath
the helical thread and a secondary flange that is positioned
beneath the support ledge. The secondary flange has an outer
circumference that is noncircular in at least one location, whereby
it may be engaged during a capping operation to prevent rotation of
the container during capping. A method of making an aerosol
container in which a preform is capped before the blow molding
process is also disclosed.
Inventors: |
Patel, JR.; Tapan Y.;
(Nashua, NH) ; Nahill; Thomas E.; (Amherst,
NH) ; Guerin; Stephen R.; (Milford, NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GRAHAM PACKAGING COMPANY, L.P. |
Lancaster |
PA |
US |
|
|
Assignee: |
GRAHAM PACKAGING COMPANY,
L.P.
Lancaster
PA
|
Family ID: |
45541081 |
Appl. No.: |
16/251670 |
Filed: |
January 18, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14945949 |
Nov 19, 2015 |
10202233 |
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16251670 |
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13031877 |
Feb 22, 2011 |
9221596 |
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14945949 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65D 41/0471 20130101;
B65D 83/38 20130101; B29C 49/4205 20130101; Y10T 29/4998 20150115;
B29C 49/20 20130101; B29L 2031/7142 20130101; B29C 49/56 20130101;
B29K 2105/258 20130101; B29C 49/00 20130101; B29K 2067/003
20130101; B65D 1/0246 20130101 |
International
Class: |
B65D 83/38 20060101
B65D083/38; B65D 1/02 20060101 B65D001/02; B65D 41/04 20060101
B65D041/04; B29C 49/20 20060101 B29C049/20; B29C 49/42 20060101
B29C049/42; B29C 49/56 20060101 B29C049/56; B29C 49/00 20060101
B29C049/00 |
Claims
1. A method of assembling an aerosol container, comprising:
providing a container having a threaded finish portion having at
least one helical thread, a support ledge positioned beneath the
threaded finish portion, the support ledge having at least one
position-registering recess defined therein, and a secondary flange
positioned beneath the support ledge, the secondary flange having
an outer circumference that is noncircular in at least one
location; preventing rotation of the container by engaging the
noncircular portion of the secondary flange; screwing at least a
portion of an aerosol dispensing closure assembly onto the threaded
finish portion at a torque that is within a range of about 15
in-lbs to about 50 in-lbs; and pressurizing the container with an
aerosol mixture having an aerosol propellant.
2. The method according to claim 1, wherein the support ledge has a
first maximum outer diameter and the secondary flange has a second
maximum outer diameter, and wherein the second maximum outer
diameter is substantially the same as the first maximum outer
diameter.
3. The method according to claim 1, wherein the support ledge has a
first maximum outer diameter and the secondary flange is a second
maximum outer diameter, and wherein the second maximum outer
diameter is not substantially greater than the first maximum outer
diameter.
4. The method according to claim 1, wherein the secondary flange
has at least one substantially flat portion defined thereon.
5. The method according to claim 1, further comprising securing the
aerosol dispensing closure against rotation with respect to the
container by applying a securement means.
6. The method according to claim 1, wherein the threaded finish
portion and the main body portion are fabricated from a material
comprising polyethylene terephthalate.
7. The method according to claim 1, wherein a space is defined
between the support ledge and the secondary flange, and the space
has a minimum vertical dimension that is at least about 1 mm.
8. The method according to claim 7, wherein the minimum vertical
dimension is at least about 1.5 mm.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] 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 blow molded plastic
aerosol container having a finish portion that is constructed and
arranged to provide maximum resistance to deformation and stress
cracking at high internal pressures.
2. Description of the Related Technology
[0002] 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.
[0003] 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.
[0004] 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.
[0005] One common type of plastic container is fabricated from a
material such as polyethylene terephthalate (PET) and is
manufactured from an injection molded preform having a threaded
finish portion using the reheat stretch blow molding process. While
such containers hold some promise for aerosol applications, they
are susceptible to stress cracking in the finish portion while
under pressurization. In addition, the finish portion of such
containers has a tendency to deform when the container is
pressurized, possibly resulting in a loss of sealing integrity
between the container and the aerosol dispensing closure.
[0006] A plastic aerosol container that utilizes a threaded finish
portion also requires application of an aerosol dispensing closure
to the finish portion at a torque that may be greater than that
used for the application of closures to conventional, non-aerosol
containers. Conventional capping machines may be unable to generate
such torque without causing undesired rotation of the
container.
[0007] A need exists for an improved blow molded plastic aerosol
container that is less susceptible to stress cracking and
deformation in the finish region than are conventional blow molded
containers. A need also exists for a plastic aerosol container that
can have an aerosol dispensing closure applied thereto at higher
torques without rotation of the container.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is an object of the invention to provide an
improved blow molded plastic aerosol container that is less
susceptible to stress cracking and deformation in the finish region
than are conventional blow molded containers.
[0009] It is further an object of the invention to provide a
plastic aerosol container that can have an aerosol dispensing
closure applied thereto at higher torques without rotation of the
container.
[0010] In order to achieve the above and other objects of the
invention, an aerosol container according to a first aspect of the
invention includes a main body portion containing an aerosol
mixture having an aerosol propellant. The container further
includes a threaded finish portion that is unitary with the main
body portion. The threaded finish portion has at least one helical
thread, a support ledge beneath the helical thread and a secondary
flange that is positioned beneath the support ledge. The secondary
flange has an outer circumference that is noncircular in at least
one location, whereby it may be engaged during a capping operation
to prevent rotation of the container during capping.
[0011] A method of assembling an aerosol container according to a
second aspect of the invention includes steps of providing a
container having a threaded finish portion, a support ledge
positioned beneath the threaded finish portion and a secondary
flange positioned beneath the support ledge. The secondary flange
has at least one noncircular portion. A method further includes a
step of preventing rotation of the container by engaging the
noncircular portion of the secondary flange, and screwing at least
a portion of an aerosol dispensing closure assembly onto the
threaded finish portion at a torque that is within a range of about
15 in-lbs to about 50 in-lbs. The container is then pressurized
with an aerosol mixture having an aerosol propellant.
[0012] A method of making an aerosol container according to a third
aspect of the invention includes steps of providing a preform
having a threaded finish portion, a support ledge positioned
beneath the threaded finish portion and a secondary flange
positioned beneath the support ledge, the secondary flange having
at least one noncircular portion; preventing rotation of the
preform by engaging the noncircular portion of the secondary
flange; screwing at least a portion of an aerosol dispensing
closure assembly onto the threaded finish portion of the preform;
and blow molding an aerosol container from the preform.
[0013] 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
[0014] FIG. 1 is a fragmentary cross-sectional view taken along
lines 1-1 in FIG. 2;
[0015] FIG. 2 is a top plan view of an aerosol container assembly
that is constructed according to a preferred embodiment of the
invention;
[0016] FIG. 3 is a bottom plan view of the aerosol container
assembly that is shown in FIG. 2;
[0017] FIG. 4 is a side elevational view of the finish portion of
the aerosol container assembly that is shown in FIG. 2;
[0018] FIG. 5 is a cross-sectional view taken along lines 5-5 in
FIG. 3;
[0019] FIG. 6 is a cross-sectional view taken along lines 6-6 in
FIG. 3;
[0020] FIG. 7 is a diagrammatical view depicting the manufacture of
an aerosol container according to an alternative embodiment of the
invention;
[0021] FIG. 8 is a diagrammatical view depicting an aerosol closure
assembly according to the preferred embodiment of the
invention;
[0022] FIG. 9 is a cross-sectional view taken through a preform
that is constructed according to the preferred embodiment of the
invention;
[0023] FIG. 10 is a flowchart depicting a method according to the
preferred embodiment of the invention; and
[0024] FIG. 11 is a flowchart depicting a method according to an
alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0025] Referring now to the drawings, wherein like reference
numerals designate corresponding structure throughout the views,
and referring in particular to FIG. 1, an aerosol container
assembly that is constructed according to a preferred embodiment of
the invention includes a plastic aerosol container 10 having a main
body portion 12 that is constructed and arranged to withstand
aerosol pressurization within a range of about 50 psig to about 300
psig. More preferably, the main body portion 12 is constructed and
arranged to withstand aerosol pressurization within a range of
about 90 psig to about 180 psig.
[0026] Plastic aerosol container 10 is preferably fabricated from a
plastic material such as polyethylene terephthalate (PET),
polyethylene naphthalate (PEN), acrilonitrile (AN), polycarbonate
(PC), 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. In the
preferred embodiment, container 10 is fabricated from a high
intrinsic viscosity polyethylene terephthalate material, which most
preferably has an intrinsic viscosity that is substantially within
a range of about 0.76 to about 0.95.
[0027] Container 10 preferably has an average wall thickness in the
main body portion 12 that is substantially within a range of about
0.018 inch to about 0.022 inch, permitting it to withstand aerosol
pressures.
[0028] The aerosol container 10 further includes a threaded finish
portion 14 that is unitary with the main body portion 12 and that
has at least one helical thread 16 defined thereon for receiving an
aerosol dispensing closure. Finish portion 14 further includes a
support ledge 18 beneath the helical thread 16, which is used to
help convey the container 10 during manufacture and filling. The
support ledge 18 has a first maximum outer diameter D.sub.L, as is
best shown in FIG. 1.
[0029] The support ledge 18 is preferably constructed so that it
has a substantially circular circumference as viewed in top plan.
In the preferred embodiment, the outer circumference of the support
ledge 18 includes a pair of small recesses 24, which are used for
registering the position of the container 10 during the capping
process, in which an aerosol dispensing closure is applied to the
finish portion 14.
[0030] The threaded finish portion 14 further includes at least one
secondary flange 20, which is positioned beneath the support ledge
18. The secondary flange 20 is preferably constructed so that it
has an outer circumference that is noncircular in at least one
location, so that it may be engaged during a capping operation to
prevent rotation of the container 10 during capping.
[0031] The secondary flange 20 in the preferred embodiment is
fabricated using an injection molding process together with the
rest of a plastic preform 50, shown in FIG. 9, which is used to
manufacture the aerosol container 10 using a reheat stretch blow
molding process. The plastic preform 50 includes a body portion
52.
[0032] In an alternative embodiment of the invention, shown in FIG.
7, a blow molded aerosol container 30 includes a threaded finish
portion 32 having a support ledge 34 and a secondary flange 36. In
this embodiment, the secondary flange 36 is fabricated during the
blow molding process through the use of a mold 38, and is not part
of the preform that is used to manufacture the container 30.
[0033] In another alternative embodiment of the invention,
anti-rotation features could be incorporated into the support ledge
of the finish portion without the provision of a secondary flange.
For example, the support ledge could be provided with two or more
flat surfaces, grooves or notches on the underside of the support
ledge or one or more lugs or notches on the top surface of the
support ledge.
[0034] The secondary flange 20 is preferably constructed so as to
have a second maximum outer diameter D.sub.S, which is not
substantially greater than the first maximum outer diameter D.sub.L
of the support ledge 18. Preferably, the second maximum outer
diameter D.sub.S of the secondary flange 20 is substantially the
same as the first maximum outer diameter D.sub.1 of the support
ledge 18.
[0035] Preferably, the secondary flange 20 has at least one
substantially flat portion defined thereon that may be engaged by a
capping machine in order to prevent relative rotation of the
container 10 with respect to the capping machine during the capping
process. As is best shown in FIG. 3, the secondary flange 20
preferably has four flat portions 22 that are evenly spaced around
the circumference of the secondary flange 20.
[0036] An annular space 28 is defined between the support ledge 18
and the secondary flange 20. Annular space 28 has a minimum
vertical dimension H.sub.S that is preferably at least about 1 mm,
and that is more preferably at least about 1.5 mm.
[0037] The aerosol container assembly further includes an aerosol
dispensing closure assembly 40, which is diagrammatically shown in
FIG. 8. The aerosol dispensing closure assembly 40 includes an
apron or collar 42 that is adapted to be threaded onto and sealed
to the threaded finish portion 14. Securing structure is preferably
provided in order to prevent the consumer from unscrewing the
aerosol dispensing closure assembly 40 from the container 10, which
in the preferred embodiment is a glue that is applied to collar 42
of the aerosol dispensing closure assembly 40 and the finish
portion 14.
[0038] The aerosol dispensing closure assembly 40 also preferably
includes a metallic insert 44 mounted on the collar 42 having a
central opening in which an aerosol dispensing valve 46 is
positioned.
[0039] A method of assembling an aerosol container assembly
according to the preferred embodiment of the invention is
diagrammatically shown in FIG. 10 and includes providing a
container 10 as described above having a threaded finish portion
14, a support ledge 18 positioned beneath the threaded finish
portion and a secondary flange 20 positioned beneath the support
ledge 18. The secondary flange 20 preferably has at least one
noncircular portion.
The collar 42 of the aerosol dispensing closure assembly 40 is then
screwed onto the threaded finish portion 14 using a commercial
capping machine. During the capping process, the container 10 is
secured against rotation relative to the capping machine by
engagement of a portion of the capping machine with the noncircular
portion of the secondary flange 20. The collar 42 of the aerosol
dispensing closure 40 is preferably screwed onto the threaded
finish portion at a torque that is substantially within a range of
about 15 in-lbs to about 50 in-lbs. The container 10 is then filled
with product, after which the metallic insert 44 of the aerosol
dispensing closure assembly 40 is applied to the collar and the
container is pressurized with an aerosol mixture at a range of
pressurization that is substantially between about 50 psig to about
300 psig, and more preferably substantially within a range of about
90 psig to about 180 psig using known aerosol pressurization
processes and equipment.
[0040] The aerosol mixture 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.
[0041] In an alternative embodiment that is depicted in FIG. 11,
the collar 42 of the aerosol dispensing closure assembly 40 could
be secured to the threaded finish portion 14 of the preform 50
prior to blow molding the container 10 and its main body portion
12. Securing structure is preferably provided in order to prevent
the consumer from unscrewing the aerosol dispensing closure
assembly 40 from the container 10, which in the preferred
embodiment is a glue that is applied to the collar 42 and the
finish portion 14.
[0042] During this preform capping process, the preform 50 is
secured against rotation relative to the capping machine by
engagement of a portion of the capping machine with the noncircular
portion of the secondary flange 20, shown in FIG. 9. The collar 42
is preferably screwed onto the threaded finish portion 14 of the
preform 50 at a torque that is substantially within a range of
about 15 in-lbs to about 50 in-lbs.
[0043] The container 10 is then blow molded and filled with
product, including the aerosol mixture. The container 10 is
subsequently pressurized.
[0044] 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.
* * * * *