[0001] This disclosure generally relates to containers for retaining a commodity, such as
a solid or liquid commodity. More specifically, this disclosure relates to a container
having an optimized base design to provide a balanced vacuum and pressure response,
while minimizing container weight.
[0002] This section provides background information related to the present disclosure which
is not necessarily prior art. This section also provides a general summary of the
disclosure, and is not a comprehensive disclosure of its full scope or all of its
features.
[0003] 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.
[0004] 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:

where ρ is the density of the PET material; ρa is the density of pure amorphous PET
material (1.333 g/cc); and pc is the density of pure crystalline material (1.455 g/cc).
[0005] 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.
[0006] 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 121°C - 177°C (approximately 250°F
- 350°F), 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 85°C (185°F), currently use heat setting to produce PET bottles having
an overall crystallinity in the range of approximately 25% -35%.
[0007] Unfortunately, with some applications, as PET containers for hot fill applications
become lighter in material weight (aka container gram weight), it becomes increasingly
difficult to create functional designs that can simultaneously resist fill pressures,
absorb vacuum pressures, and withstand top loading forces. According to the principles
of the present teachings, the problem of expansion under the pressure caused by the
hot fill process is improved by creating unique vacuum/label panel geometry that resists
expansion, maintains shape, and shrinks back to approximately the original starting
volume due to vacuum generated during the product cooling phase.
[0008] Further areas of applicability will become apparent from the description provided
herein. The description and specific examples in this summary are intended for purposes
of illustration only and are not intended to limit the scope of the present disclosure.
[0010] In view of this it is an object of the invention to disclose a container that has
an improved design that can better resist fill pressures, absorb vacuum pressures,
and withstand top loading forces than prior designs.
[0011] This object is achieved by a container according to claim 1. Preferred embodiments
are subject of the dependent claims.
[0012] The present teachings provide for a container defining a longitudinal axis and a
transverse direction that is transverse with respect to the longitudinal axis. The
container includes a finish and a sidewall portion extending from the finish. A plurality
of ribs are defined by the sidewall portion. A base portion extends from the sidewall
portion and encloses the sidewall portion to form a volume therein for retaining a
commodity. The base portion has a contact surface for supporting the container. A
plurality of straps extend radially along the base portion away from the longitudinal
axis in the transverse direction, each one of the straps defines a strap surface that
is closer to the finish than the contact surface. The plurality of ribs and the base
portion are configured to place the container in a state of hydraulic charge-up when
top load is applied to the container after the container is filled.
[0013] The present teachings also provide for a container defining a longitudinal axis and
a transverse direction that is transverse with respect to the longitudinal axis. The
container includes a finish, a sidewall portion, a base portion, a plurality of straps,
a plurality of rib members, and a central portion. The sidewall portion extends from
the finish. A plurality of horizontal side ribs are defined by the sidewall. The base
portion extends from the sidewall portion and encloses the sidewall portion to form
a volume therein for retaining a commodity. The base portion has a contact surface
for supporting the container. The plurality of straps extend radially along the base
portion away from the longitudinal axis in the transverse direction. Each one of the
straps defines a strap surface that is closer to the finish than the contact surface.
The plurality of base rib members are recessed within the base portion. Each one of
the plurality of base rib members is between two of the plurality of straps. A central
pushup portion is at an axial center of the base portion. The longitudinal axis extends
through the central pushup portion. The plurality of horizontal side ribs and the
base portion are configured to place the container in a state of hydraulic charge-up
when top load is applied to the container after the container is filled.
[0014] The present teachings further provide for a container defining a longitudinal axis
and a transverse direction that is transverse with respect to the longitudinal axis.
The container includes a finish, a sidewall portion, a base portion, a plurality of
straps, a plurality of rib members, and a central pushup portion. The sidewall portion
extends from the finish. A plurality of horizontal side ribs are defined by the sidewall
portion. The base portion extends from the sidewall portion and encloses the sidewall
portion to form a volume therein for retaining a commodity. The base portion has a
contact surface for supporting the container. The plurality of straps extend radially
along the base portion away from the longitudinal axis in the transverse direction.
Each one of the straps defines a strap surface that is closer to the finish than the
contact surface. A plurality of base rib members are recessed within the base portion.
Each one of the plurality of base rib members is between two of the plurality of straps.
The central pushup portion is at an axial center of the base portion. The longitudinal
axis extends through the central pushup portion. Each one of the plurality of straps
is at least partially aligned with one of the base rib members in the transverse direction
on opposite sides of the longitudinal axis. The plurality of horizontal side ribs
and the base portion are configured to place the container in a state of hydraulic
charge-up when top load is applied to the container after the container is filled.
The plurality of horizontal side ribs collapse upon application of top load, and movement
of the base portion is constrained by a standing surface, thereby causing fluid within
the volume of the container to reach an incompressible state and resist deformation
of the container.
[0015] The drawings described herein are for illustrative purposes only of selected embodiments
and not all possible implementations, and are not intended to limit the scope of the
present disclosure.
FIGS. 1-5 are views illustrating exemplary embodiments of a container with various
features of the present teachings, wherein FIG. 1 is a perspective view, FIG. 2 is
a side view, FIG. 3 is a front view, FIG. 4 is a bottom view, and FIG. 5 is a section
view taken along the line 5-5 of FIG. 4;
FIGS. 6-9 are views illustrating additional exemplary embodiments of a container with
various features of the present teachings, wherein FIG. 6 is a perspective view, FIG.
7 is a side view, FIG. 8 is a bottom view, and FIG. 9 is a section view taken along
the line 9-9 of FIG. 8;
FIGS. 10-13 are views illustrating additional exemplary embodiments of a container
with various features of the present teachings, wherein FIG. 10 is a perspective view,
FIG. 11 is a side view, FIG. 12 is a bottom view, and FIG. 13 is a section view taken
along the line 13-13 of FIG. 12;
FIGS. 14-17 are views illustrating additional exemplary embodiments of a container
with various features of the present teachings, wherein FIG. 14 is a perspective view,
FIG. 15 is a side view, FIG. 16 is a bottom view, and FIG. 17 is a section view taken
along the line 17-17 of FIG. 16;
FIGS. 18 and 19 are views illustrating additional exemplary embodiments of a container
with various features of the present teachings, wherein FIG. 18 is a bottom view and
FIG. 19 is a section view taken along the line 19-19 of FIG. 18;
FIGS. 20 and 21 are views illustrating additional exemplary embodiments of a container
with various features of the present teachings, wherein FIG. 20 is a bottom view and
FIG. 21 is a section view taken along the line 21-21 of FIG. 20;
FIGS. 22 and 23 are views illustrating additional exemplary embodiments of a container
with various features of the present teachings, wherein FIG. 22 is a bottom view and
FIG. 23 is a section view taken along the line 23-23 of FIG. 22;
FIGS. 24 and 25 are views illustrating additional exemplary embodiments of a container
with various features of the present teachings, wherein FIG. 24 is a bottom view and
FIG. 25 is a section view taken along the line 25-25 of FIG. 24;
FIGS. 26A and 26B are section and side views, respectively, of a base portion of a
container according to additional exemplary embodiments of the present disclosure;
FIGS. 27A and 27B are section and side views, respectively, of a base portion of a
container according to additional exemplary embodiments of the present disclosure;
FIG. 28A and 28B are front and side views, respectively, of a generally rectangular
container according to additional exemplary embodiments of the present disclosure;
FIGS. 29A and 29B are perspective and bottom views, respectively, of a generally cylindrical
container according to additional exemplary embodiments of the present disclosure;
FIGS. 30A and 30B are perspective and bottom views, respectively, of a generally cylindrical
container according to additional exemplary embodiments of the present disclosure;
FIGS. 31A and 31B are views of additional exemplary embodiments of a container according
to the present teachings, wherein FIG. 31A is a bottom view and FIG. 31B is a section
view taken along the line 31B-31B of FIG. 31A;
FIG. 32 is a perspective view of a mold system suitable for molding the container
of the present disclosure;
FIGS. 33A-33C is a series of graphs illustrating the relationship between strap inclination
angle and volume displacement, the number of straps and radial strength, the strap
peak angle and volume displacement, and between dimensions of a strap of the container
and a volume displacement of a hot-filled container;
FIG. 34 is a schematic section view of a container showing various curving surfaces
of a central pushup portion thereof;
FIGS. 35A-35D are schematic bottom views of a central pushup portion of a container
according to teachings of the present disclosure;
FIG. 36 is a schematic section view of a container showing various shapes for straps
thereof;
FIGS. 37-39 are schematic bottom views of the container showing various shapes for
straps thereof;
FIGS. 40-45 are views illustrating exemplary embodiments of a container according
to the invention with various features of the present teachings, wherein FIG. 40 is
a side view, FIG. 41 is a perspective view, FIG. 42 is a bottom view, FIG. 43 is a
section view taken along line 43-43 of FIG. 42, and FIGS. 44 and 45 are schematics
of a base on the container;
FIG. 46 is a graph illustrating relationship between outward strap radius and volume
displacement of containers according to the present teachings;
FIG. 47 is a graph illustrating relationship between base clearance and volume displacement
of containers according to the present teachings;
FIG. 48 is a graph illustrating relationship between standing base radius and volume
displacement of containers according to the present teachings;
FIG. 49 is a graph illustrating relationship between inward foot radius and volume
displacement of containers according to the present teachings;
FIG. 50 is a graph illustrating relationship between foot separation and volume displacement
of containers according to the present teachings;
FIG. 51 is a graph illustrating relationship between an outer strap radius and an
inner foot radius of containers according to the present teachings;
FIG. 52A is a side view of another container according to the present teachings, the
container in an as-blown, pre-filled configuration;
FIG. 52B is a side view of the container of FIG. 52A after the container has been
hot-filled and has cooled;
FIG. 52C is a side view of the filled container of FIG. 52B subject to a top load
pressure;
FIG. 52D is a side view of the filled container of FIG. 52C subject to further top
load pressure;
FIG. 53 is a graph illustrating base volume change versus pressure of an exemplary
container according to the present teachings;
FIG. 54 is a graph of filled, capped, and cooled top load versus displacement of an
exemplary container according to the present teachings;
FIG. 55 is a graph illustrating volume change versus gauge pressure of an exemplary
container according to the present teachings;
FIG. 56 is a graph illustrating body volume change versus gauge pressure of an exemplary
container according to the present teachings; and
FIG. 57 is a graph illustrating base volume change versus gauge pressure of an exemplary
container according to the present teachings.
[0016] Corresponding reference numerals indicate corresponding parts throughout the several
views of the drawings.
[0017] A container according to the invention is shown in Figs. 40 to 45. The other figures
show embodiments which are not necessarily covered by the invention but may be used
to facilitate understanding.
[0018] Example embodiments will now be described more fully with reference to the accompanying
drawings. Example embodiments are provided so that this disclosure will be thorough,
and will fully convey the scope to those who are skilled in the art. Numerous specific
details are set forth such as examples of specific components, devices, and methods,
to provide a thorough understanding of embodiments of the present disclosure. It will
be apparent to those skilled in the art that specific details need not be employed,
that example embodiments may be embodied in many different forms and that neither
should be construed to limit the scope of the disclosure.
[0019] The terminology used herein is for the purpose of describing particular example embodiments
only and is not intended to be limiting. As used herein, the singular forms "a", "an"
and "the" may be intended to include the plural forms as well, unless the context
clearly indicates otherwise. The terms "comprises," "comprising," "including," and
"having," are inclusive and therefore specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude the presence or
addition of one or more other features, integers, steps, operations, elements, components,
and/or groups thereof. The method steps, processes, and operations described herein
are not to be construed as necessarily requiring their performance in the particular
order discussed or illustrated, unless specifically identified as an order of performance.
It is also to be understood that additional or alternative steps may be employed.
[0020] When an element or layer is referred to as being "on", "engaged to", "connected to"
or "coupled to" another element or layer, it may be directly on, engaged, connected
or coupled to the other element or layer, or intervening elements or layers may be
present. In contrast, when an element is referred to as being "directly on," "directly
engaged to", "directly connected to" or "directly coupled to" another element or layer,
there may be no intervening elements or layers present. Other words used to describe
the relationship between elements should be interpreted in a like fashion (e.g., "between"
versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein,
the term "and/or" includes any and all combinations of one or more of the associated
listed items.
[0021] Although the terms first, second, third, etc. may be used herein to describe various
elements, components, regions, layers and/or sections, these elements, components,
regions, layers and/or sections should not be limited by these terms. These terms
may be only used to distinguish one element, component, region, layer or section from
another region, layer or section. Terms such as "first," "second," and other numerical
terms when used herein do not imply a sequence or order unless clearly indicated by
the context. Thus, a first element, component, region, layer or section discussed
below could be termed a second element, component, region, layer or section without
departing from the teachings of the example embodiments.
[0022] Spatially relative terms, such as "inner," "outer," "beneath", "below", "lower",
"above", "upper" and the like, may be used herein for ease of description to describe
one element or feature's relationship to another element(s) or feature(s) as illustrated
in the figures. Spatially relative terms may be intended to encompass different orientations
of the device in use or operation in addition to the orientation depicted in the figures.
For example, if the device in the figures is turned over, elements described as "below"
or "beneath" other elements or features would then be oriented "above" the other elements
or features. Thus, the example term "below" can encompass both an orientation of above
and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations)
and the spatially relative descriptors used herein interpreted accordingly.
[0023] This disclosure provides for a container being made of PET and incorporating a base
design having an optimized size and shape that resists container loading and pressures
caused by hot fill pressure and resultant vacuum, and helps maintain container shape
and response.
[0024] It should be appreciated that the size and specific configuration of the container
may not be particularly limiting and, thus, the principles of the present teachings
can be applicable to a wide variety of PET container shapes. Therefore, it should
be recognized that variations can exist in the present embodiments. That is, it should
be appreciated that the teachings of the present disclosure can be used in a wide
variety of containers, including rectangular, round, oval, squeezable, recyclable,
and the like.
[0025] As shown in FIGS. 1-5, the present teachings provide a plastic, e.g. polyethylene
terephthalate (PET), container generally indicated at 10. The exemplary container
10 can be substantially elongated when viewed from a side and generally cylindrical
when viewed from above and/or rectangular in throughout or in cross-sections (which
will be discussed in greater detail herein). Those of ordinary skill in the art would
appreciate that the following teachings of the present disclosure are applicable to
other containers, such as rectangular, triangular, pentagonal, hexagonal, octagonal,
polygonal, 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.
[0026] In some embodiments, container 10 has been designed to retain a commodity. The commodity
may be in any form such as a solid or semi-solid product. In one example, a 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 product at an elevated temperature between approximately approximately 68°C
to 96°C (155°F to 205°F) and seal the container 10 with a closure 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.
[0027] As shown in FIGS. 1-5, the exemplary plastic container 10 according to the present
teachings defines a body 12, and includes an upper portion 14 having a cylindrical
sidewall 18 forming a finish 20. Integrally formed with the finish 20 and extending
downward therefrom is a shoulder portion 22. The shoulder portion 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 portion 22 to a base portion 28 having
a base 30. In some embodiments, sidewall portion 24 can extend down and nearly abut
base 30, thereby minimizing the overall area of base portion 28 such that there is
not a discernable base portion 28 when exemplary container 10 is uprightly-placed
on a surface.
[0028] The exemplary container 10 may also have a neck 23. The neck 23 may have an extremely
short height, that is, becoming a short extension from the finish 20, or an elongated
height, extending between the finish 20 and the shoulder portion 22. The upper portion
14 can define an opening for filling and dispensing of a commodity stored therein.
The container can be a beverage container; however, it should be appreciated that
containers having different shapes, such as sidewalls and openings, can be made according
to the principles of the present teachings.
[0029] The finish 20 of the exemplary plastic container 10 may include a threaded region
46 having threads 48, a lower sealing ridge 50, and a support ring 51. The threaded
region provides a means for attachment of a similarly threaded closure or cap (not
shown). Alternatives may include other suitable devices that engage the finish 20
of the exemplary plastic container 10, such as a press-fit or snap-fit cap for example.
Accordingly, the closure or cap engages the finish 20 to preferably provide a hermetical
seal of the exemplary plastic container 10. The closure or cap is preferably of a
plastic or metal material conventional to the closure industry and suitable for subsequent
thermal processing.
[0030] In some embodiments, the container 10 can comprise a lightweight base configuration
100 generally formed in base portion 28. Base configuration 100 can comprise any one
of a number of features that facilitate vacuum response, improve structural integrity,
minimize container weight, and/or improve overall performance of container 10. As
discussed herein, base configuration 100 can be used in connection with any container
shape, however, by way of illustration, containers having rectangular and cylindrical
cross-sections will be examined. The base portion 28 functions to close off the bottom
portion of the plastic container 10 to retain a commodity in the container 10. FIGS.
1-31B illustrate a variety of base configurations 100 and base portions 28 as well,
as will be discussed.
[0031] Referring back to FIGS. 1-5, the base portion 28 of the plastic container 10, which
extends inward from the body 12, can comprise one or more contact surfaces 134 and
a central portion 136. In some embodiments, the contact surface(s) 134 is the area
of the base portion 28 that contacts a support surface (e.g. shelf, counter, and the
like) that in turn supports the container 10. As such, the contact surface 134 may
be a flat surface (an individual flat surface or a collection of separately spaced
flat surfaces that each lie within a common plane. The contact surface 134 can also
be a line of contact generally circumscribing, continuously or intermittently, the
base portion 28.
[0032] In the embodiments of FIGS. 1-5, the base portion 28 includes four contact surfaces
134, which are spaced away from each other about the longitudinal axis 150 of the
container 10. Also, in the embodiments shown, the contact surfaces 134 are arranged
at the corners of the base portion 28. However, it will be appreciated that there
can be any number of contact surfaces 134 and the contact surfaces 134 can be disposed
in any suitable position.
[0033] The base portion 28 can further include a central pushup portion 140, which is most
clearly illustrated in FIGS. 4 and 5. The central pushup portion 140 can be centrally
located (i.e., substantially centered on the longitudinal axis 150). The central pushup
portion 140 can extend generally toward the finish 20. In some embodiments, the central
pushup portion 140, when viewed in cross section (FIG. 5), is generally in the shape
of a truncated cone having a top surface 146 that is generally parallel to the support
surfaces 134. The pushup portion 140 can also include side surfaces 148 that slope
upward toward the central longitudinal axis 150 of the container 10. The side surfaces
148 can be frusto-conic or can include a plurality of planar surfaces that are arranged
in series about the axis 150.
[0034] Other shapes of the central pushup portion 140 are within the scope of the present
disclosure. For instance, as shown in FIG. 13, the pushup portion 140 can be partially
frusto-conic and partially cylindrical. Also, as shown in FIGS. 17, 23, and 25, the
pushup portion 140 can be generally frusto-conic with a plurality of ribs 171 that
extend at an angle along the side surface 148 at equal spacing about the axis 150.
Moreover, as shown in FIGS. 19 and 21, the pushup portion 140 can be annular, so that
a depending frusto-conic projects exteriorly along the axis 150. FIGS. 35A-35D show
additional shapes for the pushup portion 140 (in respective bottom views of the container
10). For instance, the top surface 146 can be defined by a plurality of convexly curved
lines that are arranged in series about the axis (FIG. 35A), an octagon or other polygon
(FIG. 35B), alternating convexly and concavely curved lines (FIG. 35C), and a plurality
of concavely curved lines (FIG. 35D). The side surface(s) 148 can project therefrom
to have a corresponding shape.
[0035] As shown in FIG. 34, the top surface 146 and/or the side surface(s) 148 can have
a concave and/or convex contour. For instance, the top surface 146 can have a concave
curvature (indicated at 146') or a convex curvature (indicated at 146"). Additionally,
the side surface 148 can have a concave curvature (indicated at 148'), a convex curvature
(indicated at 148"), or a S-shaped combination concave and convex curvature (indicated
at 148'''). This curvature can be present when the container 10 is empty. Also, the
curvature can be the result of deformation due to vacuum loads inside the container
10.
[0036] The side surface 148 can also be stepped in some embodiments. Also, the side surface
148 can include ribs, convex or concave dimples, or rings.
[0038] The central pushup 140 is generally where the preform gate is captured in the mold
when the container 10 is blow molded. Located within the top surface 146 is the sub-portion
of the base portion 28, which typically includes polymer material that is not substantially
molecularly oriented.
[0039] The container 10 can be hot-filled and, upon cooling, a vacuum in the container 10
can cause the central pushup 140 to move (e.g., along the axis 150, etc.) to thereby
decrease the internal volume of the container 10. The central pushup 140 can also
resiliently bend, flex, deform, or otherwise move in response to these vacuum forces.
For instance, the top surface 146 can be flat or can convexly curve without the vacuum
forces, but the vacuum forces can draw the top surface 146 upward to have a concave
curvature as shown in FIG. 34. Likewise, the side surfaces 148 can deform due to the
vacuum to be concave and/or convex as shown in FIG. 34. Thus, the central pushup 140
can be an important component of vacuum performance of the container 10 (i.e., the
ability of the container 10 to absorb these vacuum forces without losing its ability
to contain the commodity, withstand top loading, etc.)
[0040] Various factors have been found for the base portion 28 that can enhance such vacuum
performance. In conventional applications, it has been found that material can be
trapped or otherwise urged into the pushup portion of the base. The amount of material
in these conventional applications is often more than is required for loading and/or
vacuum response and, thus, represents unused material that adds to container weight
and cost. This can be overcome by tailoring the pushup diameter (or width in terms
of non-conical applications) and/or height to achieve improved loading and/or vacuum
response from thinner materials. That is, by maximizing the performance of the central
pushup 140, the remaining container portions need not be designed to withstand a greater
portion of the loading and vacuum forces, thereby enabling the overall container to
be made lighter at a reduced cost. When all portions of the container are made to
perform more efficiently, the container can be more finely designed and manufactured.
[0041] To this end, it has been found that by reducing the diameter of central pushup 140
and increasing the pushup height thereof, the material can be stretched more for improved
performance. With reference to FIG. 5, each container 10 having pushup 140 defines
several dimensions, including a pushup width Wp (which is generally a diameter of
the entrance of central pushup 140), a pushup height Hp (which is generally a height
from the contact surface 134 to the top surface 146), and an overall base width Wb
(which is generally a diameter or width of base portion 28 of container 10). Based
on performance testing, it has been found that relationships exist between these dimensions
that lead to enhanced performance. Specifically, it has been found that a ratio of
pushup height Hp to pushup width Wp of about 1:1.3 to about 1:1.4 is desirable (although
ratios of about 1:1.0 to about 1:1.6 and ratios of about 1:1.0 to about 1:1.7 can
be used). Moreover, a ratio of pushup width Wp to overall base width Wb of about 1:2.9
to about 1:3.1 is desirable (although ratios of about 1:2.9 to about 1:3.1 and ratios
of about 1:1.0 to about 1:4.0 can be used). Moreover, in some embodiments, central
pushup 140 can define a major diameter (e.g. typically equal approximately to the
pushup width Wp or the diameter at the lowermost portion of central pushup 140). The
central pushup 40 can further define a minor diameter (e.g. typically equal to the
diameter of the top surface 146 or the width at the uppermost portion of central pushup
140). The combination of this major diameter and minor diameter can result in the
formation of a truncated conical shape. Moreover, in some embodiments, the surface
of this truncated conical shape can define a draft angle of less than about 45 degrees
relative to central longitudinal axis 150. It has been found that this major diameter
or width can be less than about 50mm and the minor diameter or width can be greater
than about 5mm, separately or in combination.
[0042] In some embodiments shown in FIGS. 8 and 9, the container 10 can include an inversion
ring 142. The inversion ring 142 can have a radius that is larger than the central
pushup 140, and the inversion ring 142 can completely surround and circumscribe the
central pushup 140. In the position shown in FIGS. 8 and 9 and under certain internal
vacuum forces, the inversion ring 142 can be drawn upward along the axis 150 away
from the plane defined by the contact surface 134. However, when the container 10
is formed, the inversion ring 142 can protrude outwardly away from the plane defined
by the contact surface 134. The transition between the central pushup 140 and the
adjacent inversion ring 142 can be rapid in order to promote as much orientation as
near the central pushup 140 as possible. This serves primarily to ensure a minimal
wall thickness for the inversion ring 142, in particular at the contact surface 134
of the base portion 28. At a point along its circumferential shape, the inversion
ring 142 may alternatively feature a small indentation, not illustrated but well known
in the art, suitable for receiving a pawl that facilitates container rotation about
the central longitudinal axis 150 during a labeling operation.
[0043] In some embodiments, as illustrated throughout the figures and notably in FIGS. 28A-31A,
the container 10 can further comprise one or more straps 170 formed along and/or within
base portion 28. As can be seen throughout FIGS. 1-25, straps 170 can be formed as
recessed portions that are visible from the side of container 10. That is, straps
170 can be formed such that they define a surface (i.e., a strap surface 173 that
defines a strap axis of the respective strap 170). The strap surface 173 can be offset
at a strap distance Ds (FIG. 2) from contact surface(s) 134 in the Z-axis (generally
along central longitudinal axis 150 of container 10). In some embodiments, this offset
Ds between straps 170 and contact surface 134 can be in the range of about 5mm to
about 25mm. Also, the strap surface 173 can extend transverse to the axis 150 to terminate
adjacent the sidewall portion 24. The periphery of the straps 170 can contour so as
to transition into the sidewall portion 24 and/or the contact surfaces 134.
[0044] At least a portion of the strap surface 173 can extend substantially parallel to
the plane of the contact surfaces 134 as shown in FIGS. 1-4. Also, in some embodiments
illustrated in FIGS. 10-12, at least a portion of the strap surface 173 can be partially
inclined at a positive angle relative to the contact surface 134. The angle can be
less than 15 degrees in some embodiments. The angle can be greater than 15 degrees
in other embodiments.
[0045] FIG. 36 shows various shapes that the straps 170 can have. For instance, the straps
can concavely contour toward the interior of the container 10 as the strap extends
in the transverse direction (indicated at 170'). The strap can also convexly contour
away from the interior as the strap extends in the transverse direction (indicated
at 170"). Moreover, the strap can have one or more steps the along the axis 150 as
the strap extends in the transverse direction (indicated at 170"').
[0046] FIGS. 37-39 show how the straps can be shaped in plan view (viewed along the longitudinal
axis 150). For instance, the strap can have a sinusoidal curvature in the transverse
direction (indicated at 170"" in FIG. 37). The strap can also include steps as the
strap extends in the transverse direction (indicated at 170''''' in FIG. 37). The
width of the strap can increase (shown on the right side of FIG. 37) or can decrease
(shown on the left side of FIG. 37) as the strap extends transversely away from the
longitudinal axis 150. Moreover, the strap can smoothly taper in the transverse direction
(indicated at 170'''''' in FIG. 39). The width of the strap can either increase (top
and bottom straps of FIG. 39) or decrease (left and right straps of FIG. 39) as the
strap extends away from the longitudinal axis 150. Additionally, the straps can radiate
from the longitudinal axis 150 and can each have a substantially common curvature
in the transverse direction to resemble a pinwheel (indicated at 170''''''' in FIG.
38). Other shapes, curvatures, etc. are also within the scope of the present disclosure.
[0047] The shape, dimensions, and other features of the straps 170 can depend upon container
shape, styling, and performance criteria. Moreover, it should be recognized that the
offset (along the axis 15) of one strap 170 can differ from the offset of another
strap 170 on a single container to provide a tuned or otherwise varied load response
profile. Straps 170 can interrupt contact surface 134, thereby resulting in a plurality
of contact surfaces 134 (also known as a footed or segmented standing surface). Because
of the offset nature of straps 170 and their associate shape, size, and inclination
(as will be discussed), straps 170 is visible from a side view orientation and formable
via simplified mold systems (as will be discussed).
[0048] It has been found that the use of straps 170 can serve to reduce the overall material
weight needed within base portion 28, compared to conventional container designs,
while simultaneously providing sufficient and comparable vacuum performance. In other
words, straps 170 have permitted containers according to the principles of the present
teachings to achieve and/or exceed performance criteria of conventional containers
while also minimizing container weight and associated costs.
[0049] In some embodiments, container 10 can include at least one strap 170 disposed in
base portion 28. However, in alternative designs, additional straps 170 can be used,
such as two, three, four, five, or more. Multiple straps 170 can radiate from the
central pushup portion 140 and the longitudinal axis 150. In some embodiments, the
straps 170 can be equally spaced apart about the axis 150.
[0050] Typically, although not limiting, rectangular containers (FIGS. 1-28B) may employ
two or more even-numbered straps 170. The straps 170 can, in some embodiments, bisect
the midpoint (i.e., the middle region) of the respective sidewall. Stated differently,
the strap 170 can intersect the respective sidewall approximately midway between the
adjacent sidewalls. If the sidewall portion 24 defines a different polygonal cross
section (taken perpendicular to the axis 150), the straps 170 can similarly bisect
the sidewalls.
[0051] Similarly, although not limiting, cylindrical containers (FIGS. 29A-30B) may employ
three or more odd-numbered or even-numbered straps 170. As such, straps 170 can be
disposed in a radial orientation such that each of the plurality of straps 170 radiates
from a central point of base portion 28 to an external edge of the container 10 (e.g.
adjacent sidewall portion 24). It should be noted, however, that although straps 170
may radiate from a central point, that does not mean that each strap 170 actually
starts at the central point, but rather means that if a central axis of each strap
170 was extended inwardly they would generally meet at a common center. The relationship
of the number of straps used to radial strength of container 10 has shown an increasing
radial strength with an increasing number of straps used (see FIG. 23B).
[0052] It should also be noted that strap 170 can be used in conjunction with the aforementioned
central pushup 140, which would thereby interrupt straps 170. However, alternatively,
it should be noted that benefits of the present teachings may be realized using straps
170 without central pushup 140.
[0053] As illustrated in the several figures, straps 170 can define any one or a number
of shapes and sizes having assorted dimensional characteristics and ranges. However,
it has been found that particular strap designs can lead to improved vacuum absorption
and container integrity. By way of non-limiting example, it has been found that straps
170 can define a strap plane or central axis 172 that is generally parallel to contact
surface 134 and/or a surface upon which container 10 sits, thereby resulting in a
low strap angle. In other embodiments, strap plane/axis 172 can be inclined relative
to contact surface 135 and/or the surface upon which container 10 sits, thereby resulting
in a high strap angle. In some embodiments, this inclined strap plane/axis 172 can
be inclined such that a lowest-most portion of inclined strap plane/axis 172 is toward
an inbound or central area of container 10 and a highest-most portion of inclined
strap plane/axis 172 is toward an outbound or external area of container 10 (e.g.
adjacent sidewall portion 24). Examples of such inclination can be seen in FIGS. 26B
and 27B.
[0054] Low strap angles (e.g., FIGS. 1-4) provide base flexibility resulting in base flex
that displaces volume through upward deflection. This upward deflection will be enhanced
under vertical load providing additional volume displacement, transitioning to positive
pressure to maximize filled capped topload. The volume displacement causes increased
vacuum in the container 10. This complementary "co-flex base" technology provides
volume displacement & filled capped topload performance thereby resulting in a "lightweight
panel-less" container configuration for multi-serve applications. Conversely, a high
strap angle (e.g., FIGS. 26B and 27B) provides base rigidity resulting in a base that
enhances vertical and horizontal load bearing properties. Rectangular container designs
provide sufficient volume displacement. This complementary "rigid-base" technology
provides enhanced handling properties on fill-lines and tray distribution offerings
thereby resulting in a "lightweight tray capable" container configuration for multi-serve
applications.
[0055] By way of non-limiting example, it has been found that an inclination angle α (FIG.
19) of strap plane/axis 172 of about 0 degrees to about 30 degrees (i.e. strap angle)
can provide improved performance. This strap angle α can be measured in a side cross-section
take along strap plane or axis 172 relative to a horizontal reference plane or axis
as shown in FIG. 19. However, it should be recognized that other strap angles may
be used and/or the direction of inclination can be varied. The relationship of inclination
angle α to volume displacement of container 10 has shown an increasing volume displacement
with a decreasing inclination angle α (see FIG. 33A).
[0056] With particular reference to FIGS. 26A-27B, it should be noted that strap 170 can
further define or include a secondary contour or shape when viewed generally along
strap plane or axis 172. That is, when viewing from the side of the container 10,
the strap 170 can define a peaked shape or trapezoid shape adjacent the sidewall portion
24 having a raised central area and downwardly extending side surfaces (see FIGS.
FIG. 26B and 27B) as opposed to defining a generally flat, single plane. The trapezoidally
shaped portion can be planar also and disposed at a draft angle relative to a horizontal
(imaginary) reference line. This draft angle can be between 0 degrees and 45 degrees.
In some embodiments, this section of the strap 170 can have a triangular shape that
further provides improved vacuum response and structural integrity while simultaneously
permitting reduction in material weight and costs. By way of non-limiting example,
it has been found that a peak 175 of the strap 170 (FIGS. 19, 26B and 27B) can define
a peak angle β (FIG. 19) relative to a vertical or perpendicular reference line in
the range of about 0 degrees to 90 degrees (flat strap 170). In some embodiments,
peak angle β can define a range of about 1 degree to about 45 degrees. However, it
should be recognized that other angles may be used and/or the direction and overall
shape of strap 170 can be varied. The relationship of peak angle β to volume displacement
of container 10 has shown an increasing volume displacement with a decreasing peak
angle β (see FIG. 23C).
[0057] In some embodiments, as illustrated in FIGS. 1, 12, 16, 18, 20, 22, 24, 29B, 30B,
and 40-42, base portion 28 can further comprise one or more ribs 180 formed in (e.g.,
entirely within) or along strap 170, or between two straps 170. Ribs 180 can include
an inwardly-directed channel (recessed toward the interior of the container 10) or
outwardly-directed channel (projecting outward from the interior of the container
10). Also, the rib 180 can be contained entirely within the respective strap 170 or
can extend out of the respective strap 170 in some embodiments. The ribs 180 can serve
to tune or otherwise modify the vacuum response characteristics of straps 170. In
this way, ribs 180 serve to modify the response profile of one or more straps 170.
With reference to the several figures, ribs 180 can follow one of a number of pathways,
such as a generally V-shaped pathway (FIGS. 29B, 30B) or along longitudinal axis 180
extending from the central longitudinal axis 150. In some embodiments, these pathways
can define a pair of arcuate channels 182 terminating at a central radius 184.
[0058] The plastic container 10 of the present disclosure 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 a preform (not shown) 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. An exemplary
method of manufacturing the plastic container 10 will be described in greater detail
later.
[0059] Referring to FIG. 32, exemplary embodiments of a mold system 306 for blow molding
the container 10 is illustrated. The mold system 306 can be employed for the manufacture
of container geometries, namely base geometries, that could not be previously made.
As illustrated in FIG. 32, in some embodiments, the mold system 306 can comprise a
base system 310 disposed in operably connection with a sidewall system 320. Base system
310 can be configured for forming generally an entire portion of base portion 28 of
container 10 and extends radially and upward until a transition to sidewall portion
24. Base system 310, in some embodiments, can maintain a temperature that is different
from sidewall system 320-either hotter or colder than sidewall system 320. This can
facilitate formation of container 10 to speed up or slow down the relative formation
of the base portion 28 of container 10 during molding.
[0060] In some embodiments, base system 310 can comprise a lower pressure cylinder to extend
and retract a push up member 323 (shown in phantom in FIG. 32). The push up member
32 can be used to extend or otherwise stretch central pushup 140 axially toward the
interior of the container 10. As seen in FIG 32, push up member 322 can be centrally
disposed in base system 310. Also, the push up member 322 can have a retracted position,
wherein the push up member 322 is close to flush with surrounding portions of the
base system 310, and an extended position (shown in phantom), wherein the push up
member 322 can extend away from surrounding portions of the base system 310. In the
extended position, the push up member 322 can engage the preform during forming and
urge preform upward (e.g. inwardly) to form central pushup 140. Also, following formation
of central pushup 140, push up member 322 can be retracted to permit demolding of
the final container 10 from the mold. In some additional embodiments, push up member
322 of base system 310 can be paired with a counter stretch rod, if desired.
[0061] An exemplary blow molding method of forming the container 10 will now be described.
A preform version of container 10 includes a support ring, which may be used to carry
or orient the preform through and at various stages of manufacture. For example, the
preform may be carried by the support ring, the support ring may be used to aid in
positioning the preform in a mold cavity 321 (FIG. 32), or the support ring may be
used to carry an intermediate container once molded. At the outset, the preform may
be placed into the mold cavity 321 such that the support ring is captured at an upper
end of the mold cavity 321. In general, the mold cavity has an interior surface corresponding
to a desired outer profile of the blown container. More specifically, the mold cavity
according to the present teachings defines a body forming region, an optional moil
forming region and an optional opening forming region. Once the resultant structure
(hereinafter referred to as an intermediate container) has been formed, any moil created
by the moil forming region may be severed and discarded. It should be appreciated
that the use of a moil forming region and/or opening forming region are not necessarily
in all forming methods.
[0062] In one example, a machine (not illustrated) places the preform heated to a temperature
between approximately 88°C to 121°C (approximately 190°F to 250°F) into the mold cavity.
The mold cavity may be heated to a temperature between approximately 121°C to 177°C
(approximately 250°F to 350°F). A stretch rod apparatus (not illustrated) stretches
or extends the heated preform within the mold cavity to a length approximately that
of the intermediate container thereby molecularly orienting the polyester material
in an axial direction generally corresponding with the central longitudinal axis of
the container 10. While the stretch rod extends the preform, air having a pressure
between 2.07 MPa to 4.14 MPa (300 PSI to 600 PSI) assists in extending the preform
in the axial direction and in expanding the preform in a circumferential or hoop direction
thereby substantially conforming the polyester material to the shape of the mold cavity
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 most of the intermediate container. The pressurized air
holds the mostly biaxial molecularly oriented polyester material against the mold
cavity for a period of approximately two (2) to five (5) seconds before removal of
the intermediate container from the mold cavity. This process is known as heat setting
and results in a heat-resistant container suitable for filling with a product at high
temperatures.
[0063] Alternatively, other manufacturing methods, such as for example, extrusion blow molding,
one step injection stretch blow molding and injection blow molding, using other conventional
materials including, for example, high density polyethylene, polypropylene, 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.
[0064] With additional reference to Figures 40-45, a container 10 according to the present
invention is illustrated as a generally round container with a generally round base
30. Although the container 10 and the base 30 are generally illustrated in Figures
40-45 as being round, the container 10 and the base 30 can have any suitable shape
or size. For example, the container 10 can have any of the shapes described and/or
illustrated above, including, but not limited to, the following: rectangular, triangular,
pentagonal, hexagonal, octagonal, polygonal, or square.
[0065] The base 30 includes lightweight base configuration 100, which generally includes
straps 170, central pushup portion 140, and ribs 180. The straps 170 extend generally
radially from the central longitudinal axis 150 away from the central pushup portion
140 to the sidewall portion 124. Each one of the straps 170 is spaced apart about
the base 30. The straps 170 can be spaced apart at any suitable interval, such as
a generally uniform interval as illustrated in Figures 40-42, for example. Any suitable
number of the straps 170 can be included, such as five as illustrated or seven. Generally,
the greater the diameter of the base 30, the more straps 170 that can be included.
[0066] Each one of the straps 170 extends along the strap plane/axis 172 thereof and is
thus an elongated strap. The straps 170 are illustrated as each having a width that
generally increases along a length thereof, such that each strap is widest at the
sidewall portion 24 and most narrow proximate to the central longitudinal axis 150.
In other words, the strap surface 173 extends further from either side of the strap
plane/axis 172 at the sidewall portion 24 as compared to proximate to the central
longitudinal axis 150.
[0067] Each strap 170 generally includes a first end 176 and a second end 178, which are
at opposite ends of each strap 170 along the strap plane/axis 172 thereof. The first
end 176 is proximate to the longitudinal axis 150 and the second end is at the sidewall
portion 24. Each strap 170 extends linearly from the first end 176 to the second end
178, such as linearly along the strap plane/axis 172 extending along the strap surface
173 from the first end 176 to the second end 178 at the peak 175. Each strap 170 is
generally inclined along the strap plane/axis 172 thereof from the first end 176 to
the second end 178, such that the first end 176 is generally at the contact surface/foot
surface 134 of the base 30 and the second end 178 is at the peak 175. Therefore, the
second end 178 is further recessed into the base 30 as compared to the first end 176,
which may not be recessed into the base 30 at all. Although the straps 170 are illustrated
as generally being inclined or sloped in this manner, the straps 170 need not be inclined,
and thus the strap plane/axis 172 may extend linearly such that the strap plane/axis
172 is perpendicular to, or substantially perpendicular to, the central longitudinal
axis 150 along its entire length or a substantial portion thereof.
[0068] The base 30 further includes a plurality of the ribs 180, which as illustrated in
the container 10 of Figures 40-45 are spaced apart from the straps 170. Each rib 180
is generally elongated and extends generally radially from the central longitudinal
axis 150 along a rib longitudinal axis 190 of each rib 180. Each rib 180 extends to
the sidewall portion 24 from any suitable position along the base 30 between the central
longitudinal axis 150 and the sidewall 30. One or more of the ribs 180 can be between
two of the straps 170. For example and as illustrated, only one of the ribs 180 can
be between two of the straps 170, and can be equidistant between the two straps 170.
Any suitable number of ribs 180 can be included, such as five as illustrated. The
number of ribs 180 can generally correspond to the number of straps 170, such that
a single rib 180 is between two of the straps 170.
[0069] With reference to Figure 43, the straps 170 extend linearly and are angled such that
relative to a base surface 192 that the container 10 may be seated upon, at the inclined
strap plane/axis 172 the strap surface 173 is at an angle α from the surface 192.
The angle α can be any suitable angle such as, for example, from about 0° to about
30°, from about 5° to about 20°, about 10°, or 10°. With respect to the central longitudinal
axis 150, the straps 170 can be arranged at an angle β, which is measured between
the central longitudinal axis 150 and the inclined strap plane/axis 172. The angle
β can be any suitable angle, such as in the range of about 0° to about 90°, about
45° to about 85°, about 80°, or 80°.
[0070] With continued reference to Figure 43, the central pushup portion 140 includes a
top offset surface 194 at the top surface 146 and a bottom offset surface 196 opposite
to the top offset surface 194. The top offset surface 194 is recessed within the top
surface 146, and the bottom offset surface 196 protrudes from a bottom surface 200
of the central pushup portion 140, which is opposite to the top surface 146. The central
pushup portion 140 further includes a flange 198 defined by the side surfaces 148
of the central pushup portion 140. The side surfaces 148 are illustrated as generally
curving away from the central longitudinal axis 150, but can have any other suitable
shape or configuration as described above, such as in conjunction with Figure 34,
which illustrates side surfaces 148 having concave, convex, and generally planar surfaces.
[0071] With reference to Figures 44 and 45, the lightweight base configuration 100 is configured
to move, such as by flexing, in a variety of different directions in order to enhance
durability, structural integrity, resistance to undesirable deformation, and usefulness
of the container 10, such as when the container 10 is subject to increased vacuum
pressures during cooling of hot filled contents thereof. For example and as illustrated
in Figure 44, the central pushup portion 140 is configured to move along the central
longitudinal axis 150, and remain centered on the central longitudinal axis 150 as
the central pushup portion 140 moves along the central longitudinal axis 150. The
central pushup portion 140 is arranged such that the central longitudinal axis 150
extends through the top offset surface 194, the bottom offset surface 196, and generally
an axial center of the top surface 146.
[0072] As illustrated in Figure 44, the central pushup portion 140 can flex along the central
longitudinal axis 150 towards the finish 20 to position 140', with the side surface
148 flexing to 148'. As the central pushup portion 140 flexes along the central longitudinal
axis 150 towards the finish 20, the straps 170 also flex towards the finish 20, such
as to the position at 170' of Figure 44. Relative to a line 210 extending from about
the outward strap radius 202 parallel to base surface 192 that container 10 may be
seated on, and perpendicular to axis 150, the straps 170 flex across an angle α up
to the line 210 and flex across angle β up and away from the line 210. The angles
α and β are the same or generally the same.
[0073] As the straps 170 move to the position at 170', an outward strap radius 202 will
generally decrease and move to position 202'. The outward strap radius 202/202' is
generally measured at the smallest radius where the straps 170 transition to the sidewall
portion 24 at an interior of the container 10. As illustrated in Figure 46, as the
volume displaced of the container 10 increases, the outward strap radius 202 generally
decreases to 202'. At 3% volume displaced, for example, the outward strap radius 202
generally decreases from about 10% to about 40%, such as 25% or about 25% of the original;
or to within a range of about 0.9 times to about 0.6 times the original, such as 0.75
times or about 0.75 times the original. The degree to which the outward strap radius
202 decreases will depend on the size and the composition of the container 10, as
well as on the contents thereof and the number of straps 170 present. For example,
the greater the number of straps 170 present, the more that the outward strap radius
202 will decrease.
[0074] With reference to Figure 45, as the central pushup portion 140 moves along the central
longitudinal axis 150 towards the finish 20, a base clearance Cb will increase a distance
Cb', thereby making the overall base clearance Cb + Cb'. With respect to Figure 47
for example, as the volume displaced percentage increases, the distance Cb' will also
increase. At 3% volume displaced for example, the base clearance will increase anywhere
from about 3mm to about 7mm. In other words, the distance Cb' will increase to within
a range of from about 3mm to about 7mm. The distance that the base clearance increases,
which is identified in Figure 45 as Cb', depends on the size and the composition of
the container 10, as well as on the contents thereof and the number of straps 170
present. For example, the greater the number of straps 170 present, the more that
the base clearance will increase, and the greater that the distance Cb' will be.
[0075] As also illustrated in Figure 45, as the central pushup portion 140 moves towards
the finish 20, the contact/foot surface 134 moves towards the finish 20 to position
134', thus decreasing standing base radius Rsb to Rsb'. The standing base radius is
generally measured from the central longitudinal axis 150 to a point where the contact/foot
surface 134 makes contact with surface 192. With reference to Figure 48, as the volume
displaced percentage increases, the standing base radius will generally decrease from
Rsb to Rsb'. At 3% volume displacement, for example, the standing base radius will
generally decrease to Rsb' within a range of from about 28mm to about 40mm. Again,
the distance that the standing base radius decreases will depend on the size and composition
of the container, the contents thereof, and the number of straps 170 present.
[0076] With reference to Figure 49, as the volume displaced of the container 10 increases
and the side surface 148 flexes to 148' as illustrated in Figure 45, an inward foot
radius of the base configuration 100 increases as measured at about a midway point
along the curved side surface 148. At 3% volume displacement, for example, the inward
foot radius can increase about 1.1 times to about 2.0 times the original before displacement,
such as 1.5 times or about 1.5 times the original. The decrease in the outward strap
radius and the increase in the inward foot radius are directly proportional. For example,
the inward foot radius increases a distance that is about 1.2 times to about 3.3 times,
or about 2 times, the distance that the outward strap radius decreases. Thus, if the
inward foot radius increases about 2 times the distance that outward strap radius
decreases, then the outward strap radius will decrease 10% or about 10%, and the inward
foot radius will increase 20% or about 20%. Any suitable relationship can be established
between the outward (or outer) strap radius and the inward (or inner) foot radius.
With reference to Figure 1 for example, the relationship between the outward strap
radius and the inward foot radius can be set at any point in the illustrated box.
[0077] As the volume displaced of the container increases, the width Ws of each strap 170
(see Figure 40 for example), decreases. The width can be measured between any suitable
points of each strap 170. For example, the width of each strap 170 can be measured
between two points that are on opposite sides of the strap plane/axis 172, furthest
from the longitudinal axis 150, and configured to rest on planar base surface 192
when the container 20 is seated on the planar base surface 192. As the width Ws of
each strap 170 decreases, the feet 134 between the straps 170 move closer together,
thus decreasing a foot separation distance between the feet 134. With reference to
Figure 50, as the volume displaced increases, the foot separation distance also decreases.
At a volume displacement of about 3%, the foot separation distance will decrease about
5% to about 20%, such as about 10% to about 17%, such as about 12.5%. The width Ws
of the straps 170 is effectively the separation distance between the straps 170, and
thus the width Ws of the straps 170 will decrease the same amount as the separation
distance.
[0078] With additional reference to Figures 52A-52D, another configuration of the container
10 according to the present teachings is illustrated. Figure 52A illustrates the container
10 in an as-blown, pre-filled configuration. Figure 52B illustrates the container
10 after being hot-filled and subsequently cooled, with the as-blown position shown
at AB. Figure 52C illustrates the container 10 subject to top load pressure, with
the as-blown position shown at AB. Figure 52D illustrates the container 10 subject
to additional top load pressure, with the as-blown position shown at AB. The container
10 of Figures 52A-52D includes the generally round base portion 30 and the light base
configuration 100 described above. Thus, the container 10 of Figures 52A-52D includes
the straps 170 and the central pushup portion 140, and may include the ribs 180 as
well.
[0079] The main body portion 12 includes the sidewall 24, which extends to the base portion
30 of the container 10. The sidewall 24 defines an internal volume 326 of the container
10 at an interior surface thereof. The sidewall 24 may be tapered inward towards the
longitudinal axis 150 at one or more areas of the sidewall 24 in order to define recesses
or ribs 350 at an exterior surface of the sidewall 32, as well as an inwardly tapered
portion 352 between the ribs 350 and the shoulder portion 22. As illustrated, the
sidewall 24 defines five recesses or ribs 350a-350e. However, any suitable number
of recesses or ribs 350 can be defined. The ribs 350 can have any suitable external
diameter, which may vary amongst the different ribs 350.
[0080] In response to an internal vacuum, the ribs 350 can articulate about the sidewall
24 to arrive at a vacuum absorbed position, as illustrated in Figure 52B for example.
Thus, the ribs 350 can be vacuum ribs. The ribs 350 can also provide the container
10 with reinforcement features, thereby providing the container 10 with improved structural
integrity and stability. Larger ribs, such as rib 350a which has a larger vertical
height and is recessed deeper in the sidewall 24 relative to other ribs 350, will
have a greater vacuum response. Smaller ribs, such as ribs 350b, 350c, and 350e, will
provide the container with improved structural integrity.
[0081] The combination of base portion 30, which as described above is a vacuum base portion
30, and the horizontal ribs 350 allows the container 10 to reach a state of hydraulic
charge up when a top load force is applied after the container 10 is filled, as illustrated
in Figures 52C and 52D for example, which allows the container 10 to maintain its
basic shape. This movement of the base portion 30 caused by top load force is constrained
by the standing surface, and the horizontal ribs 350 begin to collapse, thereby causing
filled internal fluid to approach an incompressible state. At this point, the internal
fluid resists further compression and the container 10 behaves similar to a hydraulic
cylinder, while maintaining the basic shape of the container 10.
[0082] More specifically, in the as-blown, prefilled configuration AB of Figure 52A, the
container 10 stands upright while resting on diaphragm 354, and volume and pressure
are zero or generally zero, thereby providing the container 10 in phase 1. Figure
53 is a graph of base volume change versus pressure, and Figure 54 is a graph of filled,
capped, and cooled top load versus displacement of an exemplary container 10 according
to the present teachings. The various phases described herein are illustrated in Figures
53 and 54.
[0083] With reference to Figure 52B, after the container 10 is hot-filled and cooled, the
base portion 30 is pulled up towards an upper end 356 of the container 10 due to internal
vacuum. The upper end 356 is at the finish 20 and is opposite to a lower end 358 of
the container 10 at the base portion 30. Overall height of the container 10 is reduced
(compare the container 10 in the as-blown position AB), and the container 10 is supported
upright at an outer portion (or standing surface) of the base portion 30 to provide
the container 10 at phase 2. With reference to Figure 52C, application of top load
urges the base portion 30 to the original as-blown position of Figure 52A, and the
internal vacuum crosses over to positive internal pressure, thereby providing phase
3. Figure 52D illustrates phase 4 and an increase in top load, which returns the base
portion 30 substantially to the original as-blown position of Figure 52A and phase
1. The base portion 30 is constrained by the standing surface thereof, the ribs 350
collapse causing further reduction in internal volume of the container 10, and a hydraulic
spike in internal pressure advantageously facilitates very high top load capability.
[0084] Figures 55-57 illustrate pressure-volume characteristics under vacuum and filled
capped cooled top load of an exemplary container 10 according to the present teachings.
Specifically, Figure 55 illustrates container volume change versus pressure. Figure
56 illustrates body volume change versus pressure. Figure 57 illustrates the base
volume change versus pressure. From Figure 57, it is clear that the base 30 is flexible
under vacuum and significantly stiffer under top load, which is a desired characteristic
for good vacuum and filled capped cooled top load. Figure 56 demonstrates that under
top load the volume of the body and ribs 350 continuously decreases, leading to increased
pressure. The ribs 350 are suitable for allowing displacement to increase as top load
increases because the ribs 350 are axially flexible (
i.e., can be axially compressed to lead to pressure charge-up) and radially stiff to maintain
pressure. Therefore, combination of the base 30 and ribs 350 provides an advantageous
configuration for improved vacuum and top load responses.
[0085] The features described in conjunction with the container 10 illustrated in Figures
52A-52D can be included with any of the containers 10 according to the present teachings.
For example, any of the containers 10 described herein can include any suitable number
of the ribs 350, such as five ribs 350a-350e. Furthermore, any of the containers 10
according to the present teachings can exhibit the performance characteristics set
forth in the graphs at Figures 53-57, such as by providing the containers 10 with
the ribs 350 and the base portion 30 including the straps 170 and central pushup 140,
and optionally the ribs 180.
[0086] The foregoing description of the embodiments has been provided for purposes of illustration
and description. It is not intended to be exhaustive or to limit the invention. Individual
elements or features of a particular embodiment are generally not limited to that
particular embodiment, but, where applicable, are interchangeable and can be used
in a selected embodiment, even if not specifically shown or described. The same may
also be varied in many ways. Such variations are not to be regarded as a departure
from the invention, and all such modifications are intended to be included within
the scope of the invention which is only limited by the appended claims.
1. Ein Behälter, der eine Längsachse (150) und eine Querachse, die quer in Bezug auf
die Längsachse (150) verläuft, definiert, wobei der Behälter (10) Folgendes aufweist:
einen Hals (20);
einen Seitenwandbereich (24), der sich von dem Hals (20) aus erstreckt;
eine Mehrzahl von Rippen (350, 350 a-e), die durch den Seitenwandbereich (24) definiert
sind;
einen Basisbereich (28), der sich von dem Seitenwandbereich (24) aus erstreckt und
den Seitenwandbereich (24) umschließt, um ein Volumen (326) zu bilden, um darin ein
Produkt aufzunehmen,
wobei der Basisbereich (28) eine Kontaktfläche (134) zur Abstützung des Behälters
(10) aufweist; und
eine Mehrzahl von Bändern (170), von denen sich jedes radial entlang des Basisbereichs
(28) von der Längsachse (150) weg in der Querrichtung von einem ersten Ende (176)
zu einem zweiten Ende (178) erstreckt, wobei jedes der Bänder (170) eine Bandoberfläche
(173) definiert, die näher an dem Hals (20) als die Kontaktfläche (134) ist;
wobei die Mehrzahl von Rippen (350, 350 a-e) und der Basisbereich (28) den Behälter
(10) in einem Zustand von hydraulischer Aufladung platzieren, wenn von oben eine Last
auf den Behälter (10) ausgeübt wird, nachdem der Behälter (10) gefüllt ist;
wobei die Bänder (170) sich längs erstrecken und derart abgewinkelt sind, dass sie
relativ zu einer Basisfläche (192), auf die der Behälter (10) gestellt sein kann,
sich in einer geneigten Bandachse (172) erstreckt, wobei sich die Bandoberfläche (173)
in einem Winkel (α) zwischen ungefähr 5° bis ungefähr 30° von der Basisfläche (192)
aus erstreckt;
wobei der Basisbereich (28) ferner einen mittigen hervorstehenden Bereich (140) aufweist;
dadurch gekennzeichnet, dass der mittige hervorstehende Bereich (140) eine obere abgesetzte Oberfläche (194) an
der oberen Fläche (146) aufweist, und eine vom Boden abgesetzte Fläche (196) gegenüber
der von der oberen Fläche abgesetzten Fläche (194), und dass die obere abgesetzte
Fläche (194) innerhalb der oberen Fläche (146) zurückgesetzt ist, und dass die vom
Boden abgesetzte Fläche (196) von einer Bodenfläche (200) des mittigen hervorstehenden
Bereichs (140) hervorsteht, die gegenüber der oberen Fläche (146) ist, und dass der
mittige hervorstehende Bereich (140) einen Flansch (198) einschließt, der von den
Seitenflächen (148) des mittigen hervorstehenden Bereichs (140) definiert ist.
2. Der Behälter nach Anspruch 1, bei dem die Mehrzahl von Rippen (350, 350 a-e) bei Anwendung
einer Last von oben kollabieren, und wobei die Bewegung des Basisbereiches (28) durch
die Basisfläche (192) begrenzt ist, wodurch bewirkt wird, dass Fluid innerhalb des
Volumens (326) des Behälters (10) einen inkompressiblen Zustand erreicht und einer
Deformation des Behälters (10) widersteht.
3. Der Behälter nach Anspruch 1, bei dem jede der Bandoberflächen (173) an den Seitenwandbereich
(24) derart angrenzt, dass die Bandoberfläche (173) von einer Seite des Behälters
(10) sichtbar ist.
4. Der Behälter nach Anspruch 1, bei dem jede der Bandoberflächen (173) einen Toppunkt
(175) aufweist, der an den Seitenwandbereich (24) angrenzt und in einem Topwinkel
in Bezug auf die Längsachse (150) angeordnet ist.
5. Der Behälter nach Anspruch 1, bei dem jedes der Mehrzahl von Bändern (170) mit dem
ersten Ende (176) in der Nähe der Längsachse ist, und das zweite Ende (178) angrenzend
an den Seitenwandbereich (24), wobei jedes der Mehrzahl von Bändern (170) an dem ersten
Ende (176) enger als an dem zweiten Ende (178) ist, oder wobei jedes der Mehrzahl
von Bändern (170) sich nach außen von der Bänderlängsachse (172) aus verjüngt, so
dass jedes der Mehrzahl von Bändern (170) an dem Seitenwandbereich (24) am breitesten
ist.
6. Der Behälter nach Anspruch 1, der ferner eine Mehrzahl von Basisrippenelementen (171,
180) an dem Basisbereich (28) aufweist, wobei wenigstens eines der Mehrzahl von Basisrippenelementen
(171, 180) zwischen zwei von der Mehrzahl von Bändern (170) angeordnet ist.
7. Der Behälter nach Anspruch 6, bei dem die Mehrzahl von Basisrippenelementen (171,
180) sich entlang des Basisbereichs (28) von der Längsachse (150) in der Querrichtung
weg erstreckt, oder wobei die Mehrzahl von Basisrippenelementen (171, 180) innerhalb
des Basisbereichs (28) vertieft sind.
8. Der Behälter nach Anspruch 1, bei dem der mittige hervorstehende Bereich (140) an
einer axialen Mitte des Basisbereichs (28) ist, wobei sich die Längsachse (150) durch
den zentralen hervorstehenden Bereich (140) erstreckt.
9. Der Behälter nach Anspruch 8, bei dem die obere Fläche (146) des hervorstehenden Bereiches
(140) von der Kontaktfläche (134) beabstandet ist, wobei sich die Längsachse (150)
durch die Topfläche (146) erstreckt, und wobei sich die Seitenfläche (148) zwischen
der Kontaktfläche (134) und der Topfläche erstreckt, wobei vorzugsweise die Seitenfläche
von der Längsachse weg gekrümmt ist.
10. Der Behälter nach Anspruch 1, bei dem eine in der Querrichtung definierte Breite von
jedem der Bänder (170) abnimmt, wenn der Behälter (10) einer Volumenverschiebung ausgesetzt
ist, die ein vergrößertes Vakuum bewirkt.
11. Der Behälter nach Anspruch 1, bei dem in Bezug auf eine Linie, die sich senkrecht
zu einer Längsachse (150) des Behälters (10) erstreckt, während der Volumenverschiebung
jedes der Mehrzahl von Bändern (170) so ausgebildet ist, dass es zu dem Hals (20)
hin liegen kann, mit einem ersten Abstand zu der Linie und einem zweiten Abstand von
der Linie, wobei der erste Abstand ungefähr gleich dem zweiten Abstand ist.