U.S. patent application number 11/195610 was filed with the patent office on 2007-03-01 for plastic container finish with structural rib.
This patent application is currently assigned to GRAHAM PACKAGING COMPANY, L.P.. Invention is credited to Kapil B. Gami, Bret Sabold.
Application Number | 20070045216 11/195610 |
Document ID | / |
Family ID | 37802573 |
Filed Date | 2007-03-01 |
United States Patent
Application |
20070045216 |
Kind Code |
A1 |
Gami; Kapil B. ; et
al. |
March 1, 2007 |
Plastic container finish with structural rib
Abstract
A plastic container includes a base, a body, a shoulder and a
neck having a finish. The neck includes an inwardly-projecting
annular rib between the shoulder and the finish to increase the
strength of the finish.
Inventors: |
Gami; Kapil B.; (York,
PA) ; Sabold; Bret; (Bernville, PA) |
Correspondence
Address: |
VENABLE LLP
P.O. BOX 34385
WASHINGTON
DC
20043-9998
US
|
Assignee: |
GRAHAM PACKAGING COMPANY,
L.P.
York
PA
|
Family ID: |
37802573 |
Appl. No.: |
11/195610 |
Filed: |
August 3, 2005 |
Current U.S.
Class: |
215/42 ;
215/40 |
Current CPC
Class: |
B65D 1/023 20130101 |
Class at
Publication: |
215/042 ;
215/040 |
International
Class: |
B65D 1/02 20060101
B65D001/02; B65D 1/46 20060101 B65D001/46 |
Claims
1. A finish of a plastic container comprising: an annular rib
adapted to increase the rigidity of said finish, said annular rib
projecting radially inward on an internal surface of the container
and further forming a circumferential groove on an outer surface of
the container.
2. The finish according to claim 1, wherein said finish is formed
by blow molding.
3. The finish according to claim 1, wherein said finish further
comprises threads adapted to mate with a threaded closure.
4. A plastic container comprising: a body having a longitudinal
axis; a shoulder, said shoulder connected at a first end of said
body; a base, said base connected at a second end of said body; a
neck extending axially away from said body comprising a finish; and
an annular rib connecting said finish to said shoulder, wherein
said annular rib increases the rigidity of said finish.
5. The container according to claim 4, wherein said annular rib
projects radially inward on an internal surface of the
container.
6. The container according to claim 5, wherein said annular rib
concurrently forms a circumferential groove on an external surface
of the container.
7. The container according to claim 4, wherein said finish further
comprises threads adapted to mate with a threaded closure.
8. The container according to claim 4, wherein said finish has an
outside diameter of approximately 83 mm.
9. The container according to claim 4, wherein said plastic
container is formed by blow molding.
10. The container according to claim 4, wherein said finish is
formed by blow molding.
11. The container according to claim 4, wherein said container has
a cylindrical cross-section.
12. A plastic container comprising; a body having a first body end
and a second body end; a shoulder having a first shoulder end and a
second shoulder end; a base connected to said body at said first
body end and said first shoulder end connected to said second body
end; a neck connected to said second shoulder end; said shoulder
extending axially and radially inward between said first and second
shoulder ends in a direction away from said body; said neck further
comprising a finish and an annular rib connecting said finish to
said second shoulder end to provide increased rigidity in said
neck.
13. The container according to claim 12, wherein said annular rib
projects radially inward on an internal surface of the
container.
14. The container according to claim 13, wherein said annular rib
concurrently forms a circumferential groove on an external surface
of the container.
15. The container according to claim 12, wherein said finish
further comprises threads adapted to mate with a threaded
closure.
16. The container according to claim 12, wherein said container is
formed by blow molding.
17. The container according to claim 12, wherein said finish is
formed by blow molding.
18. The container according to claim 12, wherein said finish is
approximately 83 mm in diameter.
19. The container according to claim 12, wherein said container has
a cylindrical cross-section.
Description
BACKGROUND OF THE INVENTION
[0001] b 1. Field of the Invention
[0002] The present invention relates generally to a container, and
more particularly to a blow molded plastic container having a
wide-mouth finish.
[0003] 2. Related Art
[0004] Plastic containers for packaging are generally known in the
prior art. Such containers may be used to package a wide variety of
liquid, viscous or solid products including, for example, juices,
other beverages, yogurt, sauces, pudding, lotions, soaps in liquid
or gel form, and bead shaped objects such as candy. Generally,
sealable plastic containers may include at least a closed end
forming a base, a main body portion, a shoulder and a neck having a
finish for accepting various types of closures thereon to seal the
container.
[0005] Known plastic containers can differ from one another based
on the sizes and shapes of the various portions of each container.
For example, the bodies of many known plastic containers may have a
cylindrical cross-sectional configuration but may also have
rectangular cross-sections. Similarly, the finish portion of a
container might be made larger or smaller than conventional
finishes based on the particular application of the container.
Wide-mouth containers, for instance, enable the consumer to scoop
out viscous contents from within the container which do not readily
flow. An example of a wide-mouth plastic container is disclosed in
U.S. Pat. No. 6,555,191 to Smith et al., owned by the assignee of
the present application, the disclosure of which is incorporated by
reference.
[0006] Plastic containers may also differ based on the materials
used therein or in the process of manufacture. In an exemplary
stretch blow molding method of manufacturing blow molded plastic
containers, for example, it is customary to utilize an injection
molded preform having an injection molded threaded finish thereon.
The injection molded finish on the preform ultimately forms the
threaded finish of the container blown from the preform. Another
exemplary method of forming a plastic container involves blow
molding the entire container, including the threaded finish. In
containers manufactured by extrusion blow molding techniques, the
threaded finish is also blow molded, regardless of the size of the
finish. Nevertheless, the methods of forming the containers and the
resulting plastic containers themselves have various
shortcomings.
[0007] Generally, quality plastic containers are not only sturdy,
but also provide an air-tight seal when fitted with an appropriate
closure. In order to create a good seal between the threaded finish
of a container and a threaded closure, the threaded finish needs to
be relatively rigid. Without such rigidity, the finish may be more
prone to deflection such as, for example, ovalization, in a variety
of settings. During processing, for example, threaded closures may
initially be attached to the finish by axially punching them
thereon. Without the necessary rigidity, the finish is likely to
deflect during such attachment and a poor seal can result.
Likewise, during cooling of a container (if hot-filled), a finish
without the necessary rigidity may deflect and create sealing
issues. Furthermore, finishes that lack rigidity might flex when
squeezed or dropped during handling again resulting in improper
sealing between the finish and the closure. Suitable finish
rigidity may also be necessary during induction sealing to ensure a
good induction seal. Each of the aforementioned scenarios can thus
result in spoilage of the contents of the container because of the
poor seal. Container finishes such as, for example, blown
wide-mouth finishes, may often be excessively flexible and unable
to create a good seal once a threaded closure is attached.
[0008] Prior art injection molded finishes often provide the
necessary rigidity but may also require additional processing steps
or include additional material. Typically, the required rigidity is
achieved by either adding additional material to the finish portion
of the preform, by altering the taper angle of the shoulder portion
in the mold, or by increasing the crystallinity of the finish with
respect to the container. These solutions provide the necessary
rigidity, but detract from other aspects of the container. For
example, by adding additional material to strengthen the finish of
a container, both the weight and the cost of the container are
increased. Likewise, altering the angled taper of the shoulder to
provide necessary strength to the wide-mouth finish may ultimately
detract from a desired aesthetic appearance of the container.
Increasing the crystallinity of the finish can require additional
steps in the manufacturing process. These configurations dictate a
costly and inefficient manner of obtaining the required
rigidity.
[0009] What is needed then is an improved plastic container having
a finish that overcomes shortcomings of the aforementioned
conventional solutions.
BRIEF SUMMARY OF THE INVENTION
[0010] According to an exemplary embodiment of the instant
invention, a finish of a plastic container is provided and may
include an annular rib for increasing the rigidity of said finish.
The annular rib may project radially inward on an internal surface
of the container and may concurrently form a circumferential groove
on an outer surface of the container.
[0011] According to a further exemplary embodiment of the instant
invention, an improved wide-mouth plastic container is provided
having a rigid finish that overcomes the shortcomings of the
aforementioned conventional containers. The container may include a
body having a shoulder, a base, and a neck having a finish. The
finish may have a wide-mouth configuration. An annular rib may be
provided between the finish and the shoulder, wherein the annular
rib may increase the rigidity of the finish without requiring
additional material or changes to the particular shoulder
configuration of the container. The annular rib may further enable
the finish to be rigid enough to accept a threaded closure to
create a good seal therebetween without requiring preform redesign.
In one exemplary embodiment, the finish may be a wide-mouth finish
having a diameter of, for example, approximately 83 mm.
[0012] Further objectives and advantages, as well as the structure
and function of exemplary embodiments will become apparent from a
consideration of the description, drawings, and examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing and other features and advantages of the
invention will be apparent from the following, more particular
description of a preferred embodiment of the invention, as
illustrated in the accompanying drawings wherein like reference
numbers generally indicate identical, functionally similar, and/or
structurally similar elements.
[0014] FIG. 1 depicts a side view of an exemplary container
according to an exemplary embodiment of the present invention;
[0015] FIG. 2 depicts a sectional cut-away view of the exemplary
embodiment of the container shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Embodiments of the invention are discussed in detail below.
In describing embodiments, specific terminology is employed for the
sake of clarity. However, the invention is not intended to be
limited to the specific terminology so selected. While specific
exemplary embodiments are discussed, it should be understood that
this is done for illustration purposes only. A person skilled in
the relevant art will recognize that other components and
configurations can be used without parting from the spirit and
scope of the invention.
[0017] Referring to the drawings, FIG. 1 depicts a side view of an
exemplary container according to an exemplary embodiment of the
present invention. A plastic container 10 may include a body 11
extending along a longitudinal axis and having a first end and a
second end. The container 10 may further include a base 12, a
shoulder 13 having a first end and a second end, and a neck 14. The
second end of the shoulder 13 may be connected at the first end of
the body 11 and the base 12 may be connected at the second end of
the body 11. The neck 14 of container 10 may be connected at the
first end of the shoulder 13 and further may include a finish 15
having threads 18 on an outer surface thereof to accept a threaded
closure. The threaded closure is not further shown or discussed
herein but will be generally known and understood by one having
ordinary skill in the art.
[0018] Generally, a container 10 having the above-described
construction requires a good seal between the finish 15 and the
threaded closure in order to keep the contents of the container 10
fresh and/or preserved. This requires that the finish 15 of the
container 10 be relatively rigid such that the threaded closure can
properly seal the container 10. In the event that the finish 15 of
the container 10 is large in size, for example, where the finish 15
has a "wide-mouth" construction, the finish 15 may be excessively
flexible and unable to create a good seal once the threaded closure
is attached. A wide-mouth finish 15 may be, for example,
approximately 83 mm in diameter but the invention described herein
may be applicable to a finish of any size where the ratio of finish
diameter to finish material thickness is relatively large.
Wide-mouth finishes may be generally considered to have diameters
greater than approximately 48 mm.
[0019] The exemplary embodiment shown in FIGS. 1 and 2 depicts an
annular or circumferential rib 17 between the finish 15 of the neck
14 and the first end of the shoulder 13. The annular rib 17 may be
included in order to increase the strength and rigidity of the
finish 15 such that a good seal can be formed with the threaded
closure without requiring additional material and/or changing an
angle of the shoulder 13. The annular rib 17 may be formed during
formation of the container such as, for example, by blow molding,
and connects the finish 15 to the first end of the shoulder 13.
Alternatively, the annular rib 17 may be formed on the preform
during injection molding thereof. The annular rib 17 may form a
circumferential bead projecting radially inwardly around an inside
surface of the neck 14 of the container 10 and may further form a
circumferential groove around an outside surface of the neck 14.
The annular rib 17 adds strength and rigidity to the wide-mouth
finish without increasing the amount of material required or
drastically changing the overall aesthetic look of the container
10, as would occur if the shoulder were re-designed. The material
thickness of the annular rib 17 may be approximately the same as
the other portions of the container 10.
[0020] In an exemplary embodiment, the container 10 may include a
wide-mouth finish 15 having a diameter of approximately 83 mm. The
finish 15 may further have a wall thickness of between 0.039'' and
0.057'' as measured at unthreaded portions thereon. Without the
annular rib, the finish of the container yields approximately 3.4
lbs. of resistance at a deflection of approximately 0.25 inches
when placed sidelong in a top loading device. With the annular rib
17, however, the finish 15 of the container 10 yields approximately
10.7 lbs. of resistance at a deflection of approximately 0.25
inches when placed sidelong in the top loading device. Thus,
including the annular rib 17 in a finish 15 such as, for example, a
blown finish, may provide nearly three times the rigidity without
requiring additional material.
[0021] In addition to the aforementioned advantages of the
invention, the inwardly projecting circumferential groove formed by
the annular rib 17 may provide a point of contact for use during
processing. Typically, containers may have an outwardly projecting
flange that can be gripped by container handling equipment to move
and hold containers during processing. This outwardly projecting
flange adds material to the container, however, thus increasing the
weight and relative cost of the container. The circumferential
groove provided by the present invention may also provide a contact
point for container handling equipment, although the groove need
not necessarily serve this function.
[0022] The container 10 may further have a generally one-piece
construction and may be prepared from a monolayer plastic material,
such as a polyamide, for example, nylon; a polyolefin such as
polyethylene, for example, low density polyethylene (LDPE) or high
density polyethylene (HDPE), or polypropylene; a polyester, for
example, polyethylene terephthalate (PET) or polyethylene
napthalate (PEN); or others, which can also include additives to
vary the physical or chemical properties of the material. For
example, some plastic resins can be modified to improve the oxygen
permeability. Alternatively, the container 10 may be prepared from
a multilayer plastic material. The layers can be any plastic
material, including virgin, recycled and reground material, and can
include plastics or other materials with additives to improve
physical properties of the container. In addition to the
above-mentioned materials, other materials often used in multilayer
plastic containers include, for example, ethylvinyl alcohol (EVOH)
and tie layers or binders to hold together materials that are
subject to delamination when used in adjacent layers. A coating may
be applied over the monolayer or multilayer material, for example
to introduce oxygen barrier properties. In an exemplary embodiment,
the present container 10 is prepared from PET.
[0023] The container 10 can be used to package a wide variety of
liquid, viscous or solid products including, for example, juices,
other beverages, yogurt, sauces, pudding, lotions, soaps in liquid
or gel form, and bead shaped objects such as candy. The container
10 may be of cylindrical cross-sectional configuration. The body of
the container 10, as formed, may be substantially tubular, but may
have any cross sectional shape. Cross sectional shapes of the
container 10 may include, for example, a circular transverse cross
section, as illustrated; an oval transverse cross section; a
substantially square transverse cross section; other substantially
polygonal transverse cross sectional shapes such as triangular,
pentagonal, etc.; or combinations of curved and arced shapes with
linear shapes.
[0024] The container 10 can further be made by conventional blow
molding processes including, for example, stretch blow molding and
extrusion blow molding.
[0025] In stretch blow molding, a preformed parison, or preform,
may be prepared from a thermoplastic material, such as by an
injection molding process. The preform may include the threaded
finish 15 and the annular rib 17. In another embodiment, however,
the threaded finish 15 and annular rib 17 may be formed during blow
molding. In either case, the preform may be positioned between two
open blow mold halves. The blow mold halves close about the preform
and cooperate to provide a cavity into which the preform is blown
to form the container. After molding, the mold halves open to
release the container. The container may then be sent to a trimmer
where the moil, or extra plastic material above the finish, is
removed.
[0026] In extrusion blow molding, a molten tube of thermoplastic
material, or plastic parison, may first be extruded between a pair
of open blow mold halves. The blow mold halves close about the
parison and cooperate to provide a cavity into which the parison is
blown to form the container. As formed, the container can include
extra material, or flash, at the region where the molds come
together. It may also include extra material, or a moil,
intentionally present above the container finish. After the mold
halves open, the container drops out and is then sent to a trimmer
or cutter, not shown, where any flash of moil is removed. The
finished container may have a visible ridge formed where the two
mold halves used to form the container came together. This ridge is
often referred to as the parting line.
[0027] The embodiments illustrated and discussed in this
specification are intended only to teach those skilled in the art
the best way known to the inventors to make and use the invention.
Nothing in this specification should be considered as limiting the
scope of the present invention. All examples presented are
representative and non-limiting. The above-described embodiments of
the invention may be modified or varied, without departing from the
invention, as appreciated by those skilled in the art in light of
the above teachings. It is therefore to be understood that, within
the scope of the claims and their equivalents, the invention may be
practiced otherwise than as specifically described.
* * * * *