U.S. patent application number 11/545031 was filed with the patent office on 2008-04-10 for pinch grip for hot-fillable container.
Invention is credited to John A. Nievierowski.
Application Number | 20080083695 11/545031 |
Document ID | / |
Family ID | 39274223 |
Filed Date | 2008-04-10 |
United States Patent
Application |
20080083695 |
Kind Code |
A1 |
Nievierowski; John A. |
April 10, 2008 |
Pinch grip for hot-fillable container
Abstract
The present disclosure provides a one-piece plastic container
having a body defining a generally rectangular horizontal cross
section. The container includes a first pair of opposing sidewalls
and a second pair of opposing sidewalls. The body includes an upper
portion, a sidewall portion and a base. The sidewall portion is
integrally formed with and extends from the upper portion to the
base. The base closes off an end of the container. The sidewall
portion defines a grip portion having a pair of first walls that
converge with a pair of second walls. The pair of first walls
extend inboard from the first pair of opposing sidewalls. The pair
of second walls extend inboard from the second pair of opposing
sidewalls.
Inventors: |
Nievierowski; John A.; (Ann
Arbor, MI) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
39274223 |
Appl. No.: |
11/545031 |
Filed: |
October 6, 2006 |
Current U.S.
Class: |
215/384 |
Current CPC
Class: |
B65D 2501/0036 20130101;
B65D 23/102 20130101; B65D 2501/0081 20130101; B65D 1/0223
20130101 |
Class at
Publication: |
215/384 |
International
Class: |
B65D 90/02 20060101
B65D090/02 |
Claims
1. A one-piece plastic container comprising: a body defining a
generally rectangular horizontal cross section including a first
pair of opposing sidewalls and a second pair of opposing sidewalls,
said body having an upper portion, a sidewall portion and a base,
said sidewall portion integrally formed with and extending from
said upper portion to said base, said base closing off an end of
said container, said sidewall portion defining a grip portion
having a pair of first walls that converge with a pair of second
walls, said pair of first walls extending inboard from said first
pair of opposing sidewalls, respectively and said pair of second
walls extending inboard from said second pair of opposing
sidewalls, respectively.
2. The one-piece plastic container of claim 1 wherein said grip
portion is further defined by two pairs of third walls, wherein
each third wall converges with one wall of said pair of first walls
and one wall of said pair of second walls, respectively.
3. The one-piece plastic container of claim 2 wherein each of said
pair of third walls defines an angle substantially between 15 and
35 degrees relative to said base.
4. The one-piece plastic container of claim 3 wherein each of said
pair of third walls defines an angle substantially equal to 25
degrees relative to said base.
5. The one-piece plastic container of claim 1 wherein said pair of
first walls converge with said pair of second walls at an angle
substantially between 115 and 120 degrees.
6. The one-piece plastic container of claim 5 wherein said pair of
first walls converge with said pair of second walls at an angle
substantially equal to 117 degrees.
7. The one-piece plastic container of claim 5 wherein said pair of
first walls define an angle of convergence of about 16 degrees.
8. The one-piece plastic container of claim 5 wherein said pair of
second walls define an angle of convergence of about 110
degrees.
9. The one-piece plastic container of claim 5 wherein said first
pair of opposing sidewalls are shorter than said second pair of
opposing sidewalls.
10. A grip portion of a one-piece plastic container having a
generally rectangular horizontal cross section including a first
pair of opposing sidewalls and a second pair of opposing sidewalls,
said grip portion comprising: a pair of first walls that converge
with a pair of second walls, said pair of first walls extending
inboard from said first pair of opposing sidewalls, respectively
and said pair of second walls extending inboard from said second
pair of opposing sidewalls, respectively, said pair of first walls
defining an acute angle of convergence and said pair of second
walls defining an obtuse angle of convergence.
11. The grip portion of claim 10 wherein said pair of first walls
define an angle of convergence of about 16 degrees.
12. The grip portion of claim 10 wherein said pair of second walls
define an angle of convergence of about 110 degrees.
13. The grip portion of claim 10 wherein said grip portion is
further defined by two pairs of third walls wherein both the first
pair and the second pair of third walls define an angle of
convergence of about 130 degrees.
14. A grip portion of a one-piece plastic container having a
generally rectangular horizontal cross section including a first
pair of opposing sidewalls and a second pair of opposing sidewalls,
and a base, said grip portion comprising: a pair of first walls
that converge with a pair of second walls, said pair of first walls
extending inboard from said first pair of opposing sidewalls and
said pair of second walls extending inboard from said second pair
of opposing sidewalls, and two pair of third walls, each third wall
formed on one of said second pair of opposing sidewalls and
extending to both of said first and second walls, said first,
second and third walls collectively configured at relative
geometrical relationships to provide structural strength in said
grip portion and the container as a whole.
15. The grip portion of claim 14 wherein one pair of said third
walls extends to an interface wall formed with each of said pairs
of first and second walls.
16. The grip portion of claim 15 wherein the other pair of said
third walls extends to an interface wall formed with each of said
pairs of first and second walls.
17. The grip portion of claim 16 wherein said pair of first walls
extend inboard from said first pair of opposing sidewalls at a
first angle less than 20 degrees relative to said second pair of
opposing sidewalls, respectively.
18. The grip portion of claim 17 wherein said pair of second walls
extend inboard from said second pair of opposing sidewalls at a
second angle between 25 and 45 degrees relative to said first pair
of opposing sidewalls, respectively.
19. The grip portion of claim 18 wherein said two pair of third
walls all define a third angle between 15 and 35 degrees relative
to said base.
20. The grip portion of claim 19 wherein said first angle is
substantially 8 degrees, said second angle is substantially 35
degrees, and said third angle is substantially 25 degrees.
Description
TECHNICAL FIELD
[0001] This disclosure generally relates to plastic containers for
retaining a commodity, such as a solid or liquid commodity. More
specifically, this disclosure relates to a one-piece blown
container having an integrally formed pinch grip portion.
BACKGROUND
[0002] As a result of environmental and other concerns, plastic
containers, more specifically polyester and even more specifically
polyethylene terephthalate (PET) containers are now being used more
than ever to package numerous commodities previously supplied in
glass containers. Manufacturers and fillers, as well as consumers,
have recognized that PET containers are lightweight, inexpensive,
recyclable and manufacturable in large quantities.
[0003] Blow-molded plastic containers have become commonplace in
packaging numerous commodities. PET is a crystallizable polymer,
meaning that it is available in an amorphous form or a
semi-crystalline form. The ability of a PET container to maintain
its material integrity relates to the percentage of the PET
container in crystalline form, also known as the "crystallinity" of
the PET container. The following equation defines the percentage of
crystallinity as a volume fraction:
% Crystallinity = ( .rho. - .rho. a .rho. c - .rho. a ) .times. 100
##EQU00001##
where .rho. is the density of the PET material; .rho..sub.a is the
density of pure amorphous PET material (1.333 g/cc); and
.rho..sub.c is the density of pure crystalline material (1.455
g/cc).
[0004] Container manufacturers use mechanical processing and
thermal processing to increase the PET polymer crystallinity of a
container. Mechanical processing involves orienting the amorphous
material to achieve strain hardening. This processing commonly
involves stretching an injection molded PET preform along a
longitudinal axis and expanding the PET preform along a transverse
or radial axis to form a PET container. The combination promotes
what manufacturers define as biaxial orientation of the molecular
structure in the container. Manufacturers of PET containers
currently use mechanical processing to produce PET containers
having approximately 20% crystallinity in the container's
sidewall.
[0005] Thermal processing involves heating the material (either
amorphous or semi-crystalline) to promote crystal growth. On
amorphous material, thermal processing of PET material results in a
spherulitic morphology that interferes with the transmission of
light. In other words, the resulting crystalline material is
opaque, and thus, generally undesirable. Used after mechanical
processing, however, thermal processing results in higher
crystallinity and excellent clarity for those portions of the
container having biaxial molecular orientation. The thermal
processing of an oriented PET container, which is known as heat
setting, typically includes blow molding a PET preform against a
mold heated to a temperature of approximately 250.degree.
F.-350.degree. F. (approximately 121.degree. C.-177.degree. C.),
and holding the blown container against the heated mold for
approximately two (2) to five (5) seconds. Manufacturers of PET
juice bottles, which must be hot-filled at approximately
185.degree. F. (85.degree. C.), currently use heat setting to
produce PET bottles having an overall crystallinity in the range of
approximately 25%-35%.
[0006] In some instances, it may be desirable to provide a user a
grasping area on the container at which a user may engage and
firmly hold the container. In one example, a container may define a
handle near an upper shoulder of the container whereby a user can
pass fingers or a thumb through an adjacent passage formed through
the container to grasp the container. Such a configuration may be
provided on a milk container for example. In other examples, it may
be desirable to define a gripping portion integral with the body of
the container. Furthermore, it is desirable to provide a gripping
portion that contributes to the overall structural integrity of the
container.
SUMMARY
[0007] Accordingly, the present disclosure provides a one-piece
plastic container having a body defining a generally rectangular
horizontal cross section. The container includes a first pair of
opposing sidewalls and a second pair of opposing sidewalls. The
body includes an upper portion, a sidewall portion and a base. The
sidewall portion is integrally formed with and extends from the
upper portion to the base. The base closes off an end of the
container. The sidewall portion defines a grip portion having a
pair of first walls that converge with a pair of second walls. The
pair of first walls extend inboard from the first pair of opposing
sidewalls. The pair of second walls extend inboard from the second
pair of opposing sidewalls.
[0008] According to other features, the grip portion is further
defined by two pairs of third walls. Each third wall converges with
one wall of the pair of first walls and one wall of the pair of
second walls. In one example, each of the pair of third walls
defines an angle substantially between 15 and 35 degrees relative
to the base. The pair of first walls converge with the pair of
second walls at an angle substantially between 115 and 120
degrees.
[0009] According to still other features, the pair of first walls
define an acute angle of convergence and the pair of second walls
define an obtuse angle of convergence. In one example, the pair of
first walls define an angle of convergence of about 16 degrees and
the pair of second walls define an angle of convergence of about
110 degrees. Both the first and second pair of third walls define
an angle of convergence of about 130 degrees.
[0010] Additional benefits and advantages of the present disclosure
will become apparent to those skilled in the art to which the
present disclosure relates from the subsequent description and the
appended claims, taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a front elevational view a one-piece plastic
container constructed in accordance with the teachings of the
present disclosure;
[0012] FIG. 2 is a side elevational view of the container of FIG.
1;
[0013] FIG. 3 is a rear elevational view of the container of FIG.
1;
[0014] FIG. 4 is a bottom elevational view of the container of FIG.
1;
[0015] FIG. 5 is a sectional view of the container taken along line
5-5 of FIG. 2;
[0016] FIG. 6 is a sectional view of the container taken along line
6-6 of FIG. 2; and
[0017] FIG. 7 is a sectional view of an exemplary mold cavity used
during formation of the container of FIG. 1 and shown with a
preform positioned therein.
DETAILED DESCRIPTION
[0018] The following description is merely exemplary in nature, and
is in no way intended to limit the disclosure or its application or
uses.
[0019] FIGS. 1-6 show one preferred embodiment of the present
container. In the Figures, reference number 10 designates a
one-piece plastic, e.g. polyethylene terephthalate (PET),
hot-fillable container. As shown in FIG. 1, the container 10 has an
overall height A of about 288.18 mm (11.35 inches). As best shown
in FIG. 4, the container 10 is substantially rectangular in cross
sectional shape including a first pair of opposing sidewalls 12
each having a width B, and a second pair of opposing sidewalls 14
each having a width C. In the example shown, the first pair of
opposing sidewalls 12 are shorter than the second pair of opposing
sidewalls 14. First pair of opposing sidewalls 12 may be oriented
at approximately 90 degree angles to the second pair of opposing
sidewalls 14 so as to form the generally rectangular cross section
as shown in FIG. 4. The width B is about 126.29 mm (4.97 inches).
The width C is about 155.88 mm (6.26 inches). The widths B and/or C
may be selected so that the container 10 can fit within the door
shelf of a refrigerator. In this particular example, the container
10 has a volume capacity of about 128 fl. oz. (3785 cc). Those of
ordinary skill in the art would appreciate that the following
teachings of the present invention are applicable to other
containers, such as cylindrical, triangular, hexagonal, octagonal
or square shaped containers, which may have different dimensions
and volume capacities. It is also contemplated that other
modifications can be made depending on the specific application and
environmental requirements.
[0020] As shown in FIGS. 1-4, the one-piece plastic container 10
according to the present teachings defines a body 16 and includes
an upper portion 18 having a finish 20. Integrally formed with the
finish 20 and extending downward therefrom is a shoulder region 22.
The shoulder region 22 merges into and provides a transition
between the finish 20 and a sidewall portion 24. The sidewall
portion 24 extends downward from the shoulder region 22 to a base
portion 26 having a base 28. The sidewall portion 24 defines a grip
portion 30. The construction of the grip portion 30 of the
container 10 allows the sidewall portion 24 to provide increased
rigidity and structural support to the container 10. The base 28
functions to close off the bottom portion of the container 10 and,
together with the finish 20, the shoulder region 22 and the
sidewall portion 24, to retain the commodity.
[0021] With specific reference now to FIGS. 1 and 2, the finish 20
defines an opening 32. The finish 20 of the plastic container 10
may include a threaded region 33 having threads 34, and a support
ring 35. The threaded region 33 provides a means for attachment of
a similarly threaded closure or cap (not illustrated). Alternatives
may include other suitable devices that engage the finish 20 of the
plastic container 10. Accordingly, the closure or cap (not
illustrated) engages the finish 20 to preferably provide a
hermetical seal of the plastic container 10. The closure or cap
(not illustrated) is preferably of a plastic or metal material
conventional to the closure industry and suitable for subsequent
thermal processing, including high temperature pasteurization and
retort. The support ring 35 may be used to carry or orient a
preform P (FIG. 7) through and at various stages of manufacture.
For example, the preform P may be carried by the support ring 35,
the support ring 35 may be used to aid in positioning the preform P
in the mold, or an end consumer may use the support ring 35 to
carry the plastic container 10 once manufactured.
[0022] Grip portion 30 also may include horizontal ribs 46 (FIG.
3). Defined between each adjacent horizontal rib 46 are lands 48.
Lands 48 provide additional structural support and rigidity to the
sidewall portion 24 and grip portion 30 of the container 10.
[0023] With particular reference now to FIGS. 2, 5 and 6, the grip
portion 30 will now be described in greater detail. In general, the
grip portion 30 is defined by a pair of first walls 60, a pair of
second walls 62 and two pair of third walls 64 and 66,
respectively. The pair of first walls 60 extend inboard from the
first pair of opposing sidewalls 12. In one example, the first
walls 60 may define a pair of longitudinally extending raised ribs
70. The pair of second walls 62 extend inboard from the second pair
of opposing sidewalls 14. As best shown in FIGS. 2 and 5, the first
and second walls 60 and 62 may converge at an interface wall 72
substantially parallel to a longitudinal axis 76 of the plastic
container 10. The pair of first walls 60 define interface walls 80
and 82 at a transition to the third walls 64 and 66 (FIG. 2).
Similarly, the pair of second walls 62 define interface walls 84
and 86 at a transition to the third walls 64 and 66. One pair of
third walls 64 extends from the second pair of opposing sidewalls
14 to the interface wall 80 and 84 of each of the pairs of first
and second walls 60 and 62, respectively. The other pair of third
walls 66 extends from the second pair of opposing sidewalls 14 to
the interface wall 82 and 86 of each of the pairs of first and
second walls 60 and 62, respectively. It is appreciated that the
interface walls 72, 80, 82, 84 and 86, and other surfaces of the
grip portion 30 may present a smooth transition to respective
adjacent surfaces. Explained further, the interface walls 72, 80,
82, 84 and 86, and other surfaces of the grip portion 30 may define
radiused transitions formed on the container 10 to enhance user
comfort and durability of the grip portion 30 and the container 10
as a whole.
[0024] Turning now to FIG. 5, a horizontal cross section through
the grip portion 30 is shown. An extension line 60' projected from
the first walls 60 defines an angle .alpha..sub.1 relative to a
line 14' parallel to the second pair of opposing sidewalls 14. In
one example, .alpha..sub.1 may be between 6 and 20 degrees. An
extension line 62' projected from the second walls 62 defines an
angle .alpha..sub.2 relative to the second pair of opposing
sidewalls 14. In one example, .alpha..sub.2 may be between about 25
and 45 degrees. The inventors have shown through testing that one
preferred configuration includes an angle .alpha..sub.1 of about 8
degrees and an angle .alpha..sub.2 of about 35 degrees. As a
result, it can be shown that the first walls 60 may define an angle
of convergence .alpha..sub.3 of about 16 degrees. Similarly, it can
be shown that the second walls 62 may define an angle of
convergence .alpha..sub.4 of about 110 degrees. Further, it can be
shown that the first walls 60 converge with the second walls 62 at
an angle .alpha..sub.5 between about 115 and 120 degrees, and more
preferably about 117 degrees.
[0025] The grip portion 30 has been configured to define a geometry
convenient for a consumer to grasp and hold the container 10. In
one exemplary method of grasping the container 10, a consumer may
wrap a hand around the first pair of opposing sidewalls 12 at the
grip portion 30 such that a thumb engages a detent 88 formed on one
of the first walls 60 and the remaining fingers engage another
detent 88 formed on the other of the first walls 60. Because the
first walls 60 have been slanted inboard at the angle
.alpha..sub.1, a consumer is offered improved leverage during
gripping for better control of the container 10. In one example, a
span S.sub.1 defined at the innermost location of the first walls
60 is about 72.28 mm (2.85 inches). A span S.sub.2 defined between
the innermost raised ribs 70 of the first walls 60 is about 80.59
mm (3.17 inches). A span S.sub.3 defined at the outermost location
of the first walls 60 is about 83.13 mm (3.27 inches). A depth
D.sub.1 defined at the grip portion 30 from the first pair of
opposing sidewalls 12 to the interface wall 72 is about 53.34 mm
(2.10 inches). A depth D.sub.2 defined at the grip portion 30 from
the first pair of opposing sidewalls 12 to land 48 is about 76.20
mm (3.0 inches). It is appreciated that the cross-sectional
illustration of FIG. 5 may not be drawn to scale.
[0026] With particular reference now to FIG. 6, a vertical cross
section through the grip portion 30 is shown. An extension line 64'
and 66' projected from the third walls 64 and 66 defines an angle
.alpha..sub.6 relative to a line 28' parallel to the base 28. In
one example, .alpha..sub.6 may be between about 15 and 35 degrees.
The inventors have shown through testing the one preferred
configuration includes an angle .alpha..sub.6 of about 25 degrees.
It can be shown that the first pair of third walls 64 may define an
angle of convergence of .alpha..sub.7 of about 130 degrees.
Likewise, the second pair of third walls 66 may also define an
angle of convergence .alpha..sub.7 of about 130 degrees. It is
appreciated that the cross-sectional illustration of FIG. 6 may not
be drawn to scale.
[0027] The resultant geometrical configuration of the respective
first, second, and third walls 60, 62, 64 and 66 of the grip
portion 30 provides improved localized strength at the grip portion
30 as well as creates a geometrically rigid structure. The
resulting localized strength increases the resistance to creasing,
buckling, denting, bowing and sagging of the sidewall portion 24
and the container 10 as a whole during filling, packaging and
shipping operations. Specifically, the resultant localized strength
aids in preventing deformation during hot fill. As such, fillers
are able to fill the container 10 quicker since it is able to
withstand the additional pressures associated with faster filling
speeds. Through testing, it has been shown that a container formed
by current commercially available processes may be filled at a fill
speed of 90 bottles per minute (bpm). In contrast, the container 10
may be filled at a fill speed of 110 bpm. As is shown, about an 18%
improvement in fill rate is realized with the container 10 having
the grip portion 30 versus current commercially available
containers.
[0028] Additionally, this resultant localized strength prevents the
grip portion 30 from popping out or deforming when the container is
dropped during packaging and shipping. Through testing, it has been
shown that a container formed by current commercially available
processes can withstand a drop test up to 2.3 feet before the grip
portion experiences deformation or pop out. In contrast, the
container 10 having grip portion 30 can withstand a drop test up to
2.9 feet before the grip portion experiences pop out. As is shown,
about a 20% improvement is realized with the container 10 having
the grip portion 30 versus current commercially available
containers.
[0029] As explained above, the plastic container 10 has been
designed to retain a commodity. The commodity may be in any form
such as a solid or liquid product. In one example, a liquid
commodity may be introduced into the container during a thermal
process, typically a hot-fill process. For hot-fill bottling
applications, bottlers generally fill the container 10 with a
liquid or product at an elevated temperature between approximately
155.degree. F. to 205.degree. F. (approximately 68.degree. C. to
96.degree. C.) and seal the container 10 with a closure (not
illustrated) before cooling. In addition, the plastic container 10
may be suitable for other high-temperature pasteurization or retort
filling processes or other thermal processes as well. In another
example, the commodity may be introduced into the container under
ambient temperatures.
[0030] The plastic container 10 of the present invention is a blow
molded, biaxially oriented container with a unitary construction
from a single or multi-layer material. A well-known
stretch-molding, heat-setting process for making the one-piece
plastic container 10 generally involves the manufacture of the
preform P (FIG. 7) of a polyester material, such as polyethylene
terephthalate (PET), having a shape well known to those skilled in
the art similar to a test-tube with a generally cylindrical cross
section and a length typically approximately fifty percent (50%)
that of the container height.
[0031] Turning now to FIG. 7, an exemplary method of forming the
container 10 will be described. At the outset, the preform P may be
placed into a mold cavity 90. In general, the mold cavity 90 has an
interior surface corresponding to a desired outer profile of the
blown container. More specifically, the mold cavity 90 according to
the present teachings defines a body forming region 92, including a
grip forming region 94. According to one example, the grip forming
region 94 may include treatment surfaces 96. Treatment surfaces 96
may be prepared to facilitate removal of the end container from the
mold cavity 90 at the grip forming region 94. Exemplary treatments
for the treatment surfaces 96 may include etching, sand blasting or
other processes suitable to encourage separation of the end
container from the mold cavity 90. The treatment surfaces 96 cause
the grip portion 30 of the resultant container to have a frosted
appearance.
[0032] In one example, a machine (not illustrated) places the
preform P heated to a temperature between approximately 190.degree.
F. to 250.degree. F. (approximately 88.degree. C. to 121.degree.
C.) into the mold cavity 90. The mold cavity 90 may be heated to a
temperature between approximately 250.degree. F. to 350.degree. F.
(approximately 121.degree. C. to 177.degree. C.). A stretch rod
apparatus (not illustrated) stretches or extends the heated preform
P within the mold cavity 90 to a length approximately that of the
end container 10 thereby molecularly orienting the polyester
material in an axial direction generally corresponding with the
central longitudinal axis 76 of the container 10. While the stretch
rod extends the preform P, air having a pressure between 300 PSI to
600 PSI (2.07 MPa to 4.14 MPa) assists in extending the preform P
in the axial direction and in expanding the preform P in a
circumferential or hoop direction thereby substantially conforming
the polyester material to the shape of the mold cavity 90 and
further molecularly orienting the polyester material in a direction
generally perpendicular to the axial direction, thus establishing
the biaxial molecular orientation of the polyester material in the
container 10. The pressurized air holds the mostly biaxial
molecularly oriented polyester material against the mold cavity 90
for a period of approximately two (2) to five (5) seconds before
removal of the container 10 from the mold cavity 90.
[0033] Alternatively, other manufacturing methods using other
conventional materials including, for example, polyethylene
naphthalate (PEN), a PET/PEN blend or copolymer, and various
multilayer structures may be suitable for the manufacture of
plastic container 10. Those having ordinary skill in the art will
readily know and understand plastic container manufacturing method
alternatives.
[0034] While the above description constitutes the present
disclosure, it will be appreciated that the disclosure is
susceptible to modification, variation and change without departing
from the proper scope and fair meaning of the accompanying
claims.
* * * * *