Note: Descriptions are shown in the official language in which they were submitted.
CA 02591368 2007-06-06
29953-231453
CONTAINER HAVING A SMOOTH FTMSH
C'ROSS-REFERENCE TO RELATED APPLICATION5
[00011 This application is a continuation-in-part of co-pending U.S.
Patent Application No. 11/0 15,645, filed December 20, 2004, the enttre
content of
which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
100021 The present invention relates generally to a finish for a plastic
container, and more particularly, to a smooth, user-friendly finish for a
plastic
container.
Related Art
[0003) Plastic containers, such as polyolefin or PBT containers, may be
used fbr packaging food, dairy, and other drinkable products. Such containers
can
be sealed at the opening in the neck using a conventional closure such as a
screw-
on or push-on lid. Additionally or alternatively, these containers can be
thermosealed with a suitable lid, for example, a foil lid. A thermosealed lid
is
designed to be pulled off to allow access to the contents of the container.
Once
opened, the contents can be, for example, drank directly from the container
or, in
the case of larger containers, spooned, poured, or grasped from the container.
[00041 In designing plastic containers, the integrity of the lip of the
container may be critical in obtaining a good seal with the closure. This is
most
commonly accomplished by increasing the thickness of the lip. Additionally,
lip
thickness may assist in improving the top-loading capabilities of the
container.
Another issue that can arise with container lip design is that the inner edge
of the
lip (which is usually formed by a trimming operation) can present a sharp
edge.
This sharp edge can be uncomfortable and/or dangerous to the consumer, whether
they are drinking directly from the container, or grasping product located
within
the container.
[0005] = Therefore, there remains a need in the art for a plastic container
and/or a container finish that overcomes these and other shortcomings of the
prior
art.
la
CA 02591368 2007-06-06
29953-231453
BR1EF SUMMARY OF THE INVENTION
[0006] According to one exemplaryembodiment ofthe present invention,
a container defines a longitudinal axis, and comprises a neck, a finish
merging with
said neck, said finish comprising a first lip, a second lip spaced apart from
said first
lip in a direction that is substantially parallel to the longitudinal axis,
and a curved
portion connecting said first lip with said second lip.
[0007] According to another exemplary embodiment of the present
invention, a method for sealing a container comprises providing a container
defining
a longitudinal axis and having a neck and a finish merging with said neck, the
finish
comprising a first lip connected to said neck, a second lip spaced apart from
said first
lip in a direction substantially parallel to the longitudinal axis, and a
curved por6on
connecting said first lip with said second lip; and thermosealing a lid to the
container.
[0008] According to yet another exemplary embodiment of the present
invention, a finish for a plastic container defining a longitudinal axis
comprises a first
lip, a second lip spaced apart from said first lip in a direction that is
substantially
parallel to the longitudinal axis, and a curved portion connecting said first
lip with
said second lip.
[0009] According to still another exemplary embodiment of the present
invention, a container defining a longitudinal axis comprises an upper portion
including a finish, said finish comprising a first lip extending about the
longitudinal
axis and defining a first inner radial distance fram the longitudinal axis,
and a second
lip interconnected with said first lip, said second lip extending about the
longitudinal
axis and defining a second inner radial distance from the longitudinal axis,
said
second inner radial distance being larger than said first inner radial
distance. The
second lip is spaced apart from said first lip in a direction
substantiallyparallel to said
longitudinal axis.
[000101 Further objectives and advantages, as well as the structure and
function of preferred embodiments will become apparent from a consideration
ofthe
description, drawings, and examples.
2
CA 02591368 2007-06-06
29953-231453
BRIEF DESCRIPTION OF THE DRAWINGS
1000111 The foregoing and other features and advantages of the
invention will be apparent frotn the following, more particular description of
a
preferrcd embodiment of the invention, as illustrated in the accompanying
drawings wherein like reference numbers generally indicate identical,
functionally
similar, and/or structurally similar elements.
[00012] FIG. 1 depicts an exemplary embodiment of a prior art
container according to the present invention;
[00013] FIG. 2 depicts an exemplary embodiment of a prior art
container according to the present invention;
1000141 FIG. 3a depicts an exemplary embodiment of a container
according to the present invention before sealing;
[00015] FIG. 3b depicts an exemplary embodiment of a container
according to the present invention after sealing;
[00016] FIG. 4a depicts an exemplary embodiment of a container
according to the present invention befiore sealing;
[00017] FIG. 4b depicts an exemplary embodiment of a container
according to the present invention after sealing;
[00018] FIG. 5 depicts an exemplary embodiment of a container
according to the present invention;
1000191 FIG. 6 depicts a side, cross-sectional view of a portion of the
container of FIG. 5;
[00020] FIG. 7 depicts an enlarged portion of the cross-section of FIG.
6; and
(00021] FIG. 8 depicts an exemplary embodiment of the container of
FIGS. 5-7 after sealing.
DETAILED DESCRIPTION OF THE INVENTION
[00022] 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
3
CA 02591368 2007-06-06
29953-231453
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 ofthe invention. All references
cited herein
are incorporated by reference as if each had been individually incorporated.
1000231 Exemplary embodiments of the present invention provide a
plastic container, such as a polyolefin or PET container. Exemplary containers
according to the present invention can include a very thin lip that is adapted
for
thermosealing at high sealing temperatures without undesirable deformation. In
an exemplary embodiment of the invention, two lips of the neck of a container
may stick together to give a strong resistance to lip deformation.
Additionally or
alternatively, exemplary containers according to the present invention can
include
features for attaching a lid to the container, such as threads or press-on
features.
Additionally or altematively, the container finish can include two or more
lips of
varying inner radii in order to present the consumer with smoothly contoured
contact surface when consuming products from the container.
[000241 Figure 1 depicts an embodiment of a prior art container 100
having a sealing lip 101 for receiving a thermosealed lid (not shown).
Container
100 has a neck 102 that includes a neck flange 103 that merges with the
sealing lip
101. When thermosealing container 100, sealir+g lip 101 must be thick enough
so
that the sealing temperature doesn't soften the plastic and cause the sealing
lip 101
to sink into the container before foil sealing. When softening occurs, the top
surface of the sealing lip 101 can bend and the edge 104 can curl into the
interior
of the container. As a resalt, the top surface, where the seal would be
formed, is
curved and thus has less surface area for bonding to the foil seal. As a
result, the
seal can fail resulting in a rejected container. To prevent the sealing lip
101 from
sinking into container 100, the lip is typically 0.5 to 1.0 mm thick, for
example.
Such a thickness, however, results in an increase in the amount of plastic
used to
make the container, which, in turn, causes the container to be heavier and
more
expensive to construct.
1000251 The flange 103 serves several purposes in such a container.
First, it provides a contact point for support on a filling line. Second, the
flange
4
CA 02591368 2007-06-06
29953-231453
provides top load strength for storing and stacking containers. However, the
flange adds weight to the container that is not necessarily required for
structural
support of the container itself. Another disadvantage of the flange 103 is
that it
creates a concave inner surface in which the contained product can become
entrapped during storage or use, or can be hard to remove when poured from the
container.
[00026] Figure 2 depicts an embodiment of a prior art container 200
having a sealing lip 201 and a neck 202 merging with sealing lip 201. Although
the container 200 avoids the weight of an added flange, the design of the lip
201
and edge 204 suffers the same drawbacks as container 100 with lid 101 and edge
104. As similarly discussed above with respect to container 100, when
thermosealing container 200, sealing lip 201 must be thick enough so that the
sealing temperature doesn't soften the plastic and cause the sealing lip 201
to sink
into the container before foil sealing. To prevent the sealing lip 121 from
sinking
into container 200, the lip must be, for example, 0.5 to 1.0 mm thick. Such a
thickness, however, results in an increase in the amount of plastic used to
make
the container, which, in turn, causes the container to be heavier and more
expensive to construct.
[00027] The sealing lips 101, 201 in these prior art containers suffer
several drawbacks. For example, the edge 104, 204 can be relatively sharp,
causing discomfort when a consumer drinks from the container. The sharpness of
the edge 104, 204 can also be increased during the thermosealing process as
the lip
I01, 201 softens during sealing. Additionally, as previously mentioned, the
edge
104, 204 of the lip 101, 201 can curl downward during thermosealing, resulting
in
an incompetent seal and a leaking container. Although making the lips thicker
results in a more competent seal and less curling, it does not typically
prevent
sharpening of the edge 104, 204, and adds undesirable weight to the container.
A
finish having a lip according to the present invention avoids these and other
drawbacks of known lips.
[00028] Figure 3a depicts an exemplary embodiment of a
thetmosealable container 300 according to an embodiment of the present
invention. Container 300 can have a finish 308 that includes an upper lip 301,
a
5
CA 02591368 2007-06-06
29953-231453
lower lip 302, a curved portion 303, a neck 304. Container 300 also includes a
sidewal1305. As shown in Figure 3a, neck 304 merges with sidewal1305; lower
lip 302 merges with neck 304; curved portion 303 merges with lower lip 302;
and
upper lip 301 merges with curved portion 303. In such an embodiment, upper lip
301 and lower lip 302 are substantially horizontal such that the upper lip is
spaced
apart at a distance S from the lower lip in a direction that is substantially
perpendicular to the lower lip. In an exemplary embodiment of the invention,
upper lip and lower lip may be from 0.1 mm to 0.5 mm thick. In an exemplary
embodiment of the invention, the distance S can be about 0.5 to 5.0 mm.
[00029] As shown in Figure 3a, upper lip 301 has an edge 306 that may
be a sharp edge prior to thermosealing container 300 with a foil seal, for
example.
Further, container 300 has a longitudinal axis A that extends substantially
through
the center of container 300. In an exemptary embodiment of the invention, neck
304 be located at a distance Di, measured radially from longitudinal axis A
and
edge 306 can be located at a distance DZ measured radially from longitudinal
axis
A. In such an embodiment, distance D2 may be greater than or equal to Di.
[00030] Figure 3b depicts container 300 after it has been thermoseated.
As shown in Figure 3b, when heat is applied during thetmosealing, the plastic
softens and upper lip 301 can collapse towards lower lip 302. In an exemplary
embodiment of the invention, edge 306 may contact lower lip 302, effectively
removing the sharpness of edge 306 and creating a"sofft" edge from the curve
that
connects the neck 304 with the lower lip 302. Because upper lip 301 and lower
lip
302 are both substantially horizontal, when heat is applied during sealing,
the
degree to which the upper lip sinks into the container is limited by the lower
lip
302. Instead of bending excessively, the upper lip 301 can contact lower lip
302
and, due to softening that occurs during sealing, the upper lip 301 and lower
lip
302 can adhere to one another to give a strong lip resistance. Such a
container
may also provide a lightweight, thin lip that remains top-load resistant.
[00031] As shown in Figure 3b, after thermosealing, the resulting sealed
lip 301, 302 can have a substantially flat surface for sealing. Contrary to
the prior
art lips, which after thermosealing can have a curved surface, container 300
provides a flat surface 307 for thermosealing that provides more surface area
for
6
CA 02591368 2007-06-06
29953-231453
seating the foil to the upper lip 301. In an exemplary embodiment of the
invention, to create this flat surface 307, for example, heat may be applied
during
thermosealing reaches the finish of container 300, soflening upper lip 301 and
curved portion 303. When the upper lip 301 is heated during sealing, space S
may
act as an insulator between upper lip 301 and lower lip 302, so that lower lip
302
does not soften excessively, maintaining the integrity and structure of the
lower lip
and maintaining a substantially flat surface for accepting the seal. When this
happens, upper lip 301 and curve 303 may collapse towards lower lip 302 and
cause upper lip 301 to stick to lower lip 302.
1000321 The resulting container 300, as shown in Figure 3b, provides
other advantages over the prior art containers shown in Figures 1 and 2. For
example, in container 300, no product becomes trapped because container 300
does not have a neck flange or some other welled area for trapping product.
Additionally, the sharp edge is eliminated because edge 306 merges into lower
lip
302, while at the same time, a flat surface 307 for thermosealing is
maintained.
[00033] In a further exemplary embodiment of the invention, distance
DZ may be less than D,. In such an embodiment, the upper lip of the container
must be sufficiently bendable so as to prevent a sharp edge. Figure 4a depicts
an
exemplary embodiment of a thermosealable container 400 according to an
embodiment of the present invention. Container 400 can have a finish 408 that
includes an upper lip 401, a lower lip 402, a curved portion 403, a neck 404.
Container 400 also includes a sidewall 405. As shown in Figure 4a, neck 404
merges with sidewall 405; lower lip 402 merges with neck 404; curved portion
403 merges with lower lip 402; and upper lip 401 merges with curved portion
402.
[00034] In such an embodiment, upper lip 401 and lower lip 402 are
substantially horizontal such that the upper lip is spaced apart at a distance
S from
the lower lip in a direction that is substantially perpendicular to the lower
lip. In
an exemplary embodiment of the invention, upper lip and lower lip may be from
0.1 mm to 0.5 mm thick. In an exemplary embodiment of the invention, the
distance S can be about 0.5 to 5.0 mm.
[00035] As shown in Figure 4a, upper lip 401 has an edge 406 that may
be a sharp edge prior to thermosealing container 400 with a foil seal, for
example.
7
CA 02591368 2007-06-06
29953-231453
Further, container 400 has a longitudinal axis A that extends substantially
through
the center of container 400. In an exemplary embodiment of the invention, neck
404 be located at a distance Di, measured radially from longitudinal axis A
and
edge 406 can be located at a distance D2 measured radially from longitudinal
axis
A. In such an embodiment, distance D2 may be less than D,.
1000361 Figure 4b depicts container 400 after it has been thermosealed.
Prior to thermosealing, a distance D2 may be less than Di as described with
respect
to Figure 4a. As shown in Figure 4b, when heat is applied during
thermosealing,
the plastic softens and upper lip 401 can collapse towards lower lip 402.
Substantially at about the same time, edge 406 of container 400 can bend into
container 400 and extend down into the container. The resulting container 400,
as
shown in Figure 4b includes a flat edge 407 for thermosealing and eliminates
the
problems caused by having sharp edge because the upper lip bends into the
container in such a manner that the edge will not be touched by the mouth of a
consumer.
1000371 Referring to Figures 5-8, another exemplary embodiment of a
container according to the present invention is shown. The container 500 of
Figures 5-8 can be used with a thermosealed lid, as described above in
connection
with previous embodiments, or altematively, can be used with screw-on, press-
on,
or other known lid types. As shown in Figure 5, container 500 can include a
sidewal1505 having a base 550 attached at its lower end. Container 500 can
also,
include an upper portion including a neck 504 and a finish 508. Container 500
can
define a longitudinal axis A.
[00038] Referring to Figures 6 and 7, the upper portion of container 500
is shown in cross-section. As shown, the finish 508 can include an upper lip
501
and a lower lip 502. The upper lip 501 can comprise a generally horizontal
surface that extends about the longitudinal axis A and terminates in an inner
edge
506. Upper lip 501 and/or inner edge 506 can be formed, for example, when the
container is trimmed, for example, using a trim blade, reamer, or other
device,
however, other methods for forming these parts are also possible. The lower
lip
502 can comprise a radially-inward projection formed by an inwardly curved
wall
portion of the finish 508. This curved wall portion can be formed, for
example,
8
CA 02591368 2007-06-06
29953-231453
during molding of the container (e.g., blow molding or injection molding),
however, other methods for forming this part are also possible. As shown, the
upper lip 501 and the lower lip 502 are interconnected, for example, by an
integral
curved portion 509. The upper lip 501 can be spaced apart from the lower lip
502
substantially along the longitudinal axis A.
[00039] Referring to Figure 6, the finish 508 can include an optional
neck flange 503. Alternatively or additionally, the finish 508 can include
threads,
ridges, or other known features for retaining a screw-on, press-on, or other
type of
closure to the container 500.
[00040] Referring in particular to Figure 6, the inner edge 506 of the
upper lip 501 can define a first inner radial distance XI from the
longitudinal axis
A. The curved wall portion of the lower lip 502 can likewise define a second
inner radial distance X2 from the longitudinal axis A. According to an
exemplary
embodiment, the second inner radial distance X2 can be smaller than the first
inner radial distance Xl. According to this exemplary embodiment, the
relatively
smooth, curved surface of the lower lip 502 defines a smaller diameter than
the
inner edge 506 of the upper lip 501, and can prevent a user from contacting
inner
edge 506 when dispensing products from container 500 (e.g., drinking a liquid
from the container or grasping solid products from the container). This
feature
can also be beneficial when filling solid products into the container 500
(e.g.,
pickles), as it can prevent the solid products from being damaged. Thereby,
the
container 500 can present a user with a relatively smooth, curved surface
defined
by lower lip 502 when they are consuming products from container 500.
(00041] As discussed above, container 500 can be sealed by
thermosealing a lid, such as a foil lid (not shown) to the upper lip 501.
Further
details on this process are provided above with respect to the embodiments of
Figures 3-4, and apply equally to the embodiment of Figures 5-8. Additionally
or
alternatively, a screw-on or pre.ss-on lid may be provided for use with
container
500.
[00042] Referring to Figure 8, an exemplary embodiment of container
500 is shown after a lid (not shown) is thenmosealed onto the finish 508. As
discussed above with respect to the embodiments of Figures 3-4, the upper lip
501
9
CA 02591368 2007-06-06
29953-231453
can collapse down onto the lower lip 502 during thermosealing, to provide a
stronger sealing surface for the lid, and/or to improve the top load capacity
of the
container 500. Additional details regarding this process are described above
in
connection with Figures 3-4. Also, one of ordinary skill in the art will
recognize
that the upper lip 501 and lower lip 502 can alternatively maintain the
positions
shown in Figures 5 and 6 during thermosealing and/or any other type of capping
process that may be implemented.
[00043] Containers according to embodiments of the present invention
may be manufactured using current blow molding equipment and does not require
any adjustments to the blower or the demoiler, for example. All that is
required is
replacement of the neck region mold. For example, containers incorporating the
structure of the present invention can be extrusion blow molded from a
polyolefin
material (e.g., polyethylene or polypropylene), PET, or other known materials.
The material used to form the container can be single layered or multi-
layered, as
is known in the art. As is known, the containers can incorporate layers of
different
plastics, or additives in one or more layers, to improve the gas barrier
properties of
the container. Small lightweight containers can be formed in an end to end
fashion, with the necks connected by a moil that is trimmed away in separating
the
containers. As will be appreciated by persons skilled in the art, materials or
methods other than those described herein are encompassed by embodiments of
the present invention.
[00044] Containers according to embodiments of the present invention
can be filled and processed on the same equipment as prior art containers. For
example, the lower lip 302 of container 300 can curve outwardly from the neck
304, providing a surface for support during filling operations. Also, top
loading
performance can be improved without the use of a flange. This is possible
because the product can be filled closer to the top of the container which
helps aid
in support.
[00045] Lightweighting of containers according to exemplary
embodiments of the invention can be significant. In an exemplary 100cc
container
with a height of about 10 cm and a diameter of about 2-4 cm and having a
flange,
as shown in Figure 1, for example, the weight of the container may be reduced
CA 02591368 2007-06-06
29953-231453
from about 7 g to about 5 g, a reduction of about 28%. Similarly, in an
exemplary 125cc container with a height of about 5 cm and a diameter of about
6
cm, as shown In Figure 2, for example, the weight of the container may be
reduced
from about 6 g to about 4.5 g, a reduction of about 25%. While weight
reductions
of 25-30% are possible, particularly for small lightweight containers, weight
reductions of up to 10% or more, or even 20% or more can be realized with
larger
containers as well.
[00046] 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.
11
