Note: Descriptions are shown in the official language in which they were submitted.
CA 02909856 2015-10-23
BOTTLE AND METHOD OF STERILIZATION
This is a divisional of Canadian patent application no. 2,704,333, filed May
17, 2010.
TECHNICAL FIELD
The invention relates generally to a bottle suitable for use in steam
sterilization processes,
and more specifically, to a bottle having structures that can provide
sufficient strength to allow a
recycled PET bottle to be used in steam sterilization.
BACKGROUND
Steam rinse sterilization processes are often used on bottles and other
containers,
including those made of HDPE and other polymers. Such sterilization processes,
for example
using a WAB peroxide steam rinser, often result in the bottles reaching
temperatures of 75-85 C.
This temperature coincides with the glass transition temperature of PET, as
shown in FIG. 8, and
the modulus of PET changes rapidly throughout this temperature range, as shown
in FIG. 9. As
a result, the physical stability of PET bottles decreases and becomes
unpredictable and
inconsistent, resulting in shrinkage and/or deformation of the bottles. Thus,
the use of PET
bottles in steam sterilization processes can present difficulties. The use of
recycled PET (rPET)
increases the unpredictability and inconsistency of the physical properties,
as the intrinsic
viscosities of recycled materials typically exhibit greater variation.
Additionally, certain
deformation characteristics are more difficult to control in square or other
non-cylindrical
bottles, and controlling shrinkage of the bottle becomes more important as a
result.
The present device and method are provided to address the problems discussed
above and
other problems, and to provide advantages and aspects not provided by prior
bottles and other
containers of this type. A full discussion of the features and advantages of
the present invention
is deferred to the following detailed description, which proceeds with
reference to the
accompanying drawings.
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BRIEF SUMMARY
Aspects of the present invention relate to a bottle that includes a neck
portion having an
opening configured to permit filling and emptying of the bottle, a shoulder
portion connected to a
lower end of the neck portion, a sidewall connected to a lower end of the
shoulder portion and
extending vertically downward from the shoulder portion, and a base connected
to a lower end of
the sidewall and forming a bottom surface of the bottle. The sidewall has a
plurality of annular
ribs extending around a periphery of the sidewall. Each of the annular ribs
includes a plurality of
sequential enlarged portions interconnected by bridges, with each of the
enlarged portions having
a vertical width that is greater than a vertical width of each of the bridges.
According to one aspect, the sidewall further includes recessed lands located
between the
annular ribs.
According to another aspect, a first rib of the plurality of ribs is staggered
in relation to at
least one adjacent second rib of the plurality of ribs, such that the enlarged
portions of the first
rib are vertically offset from the enlarged portions of the second rib, and
the bridges of the first
rib are vertically offset from the bridges of the second rib. In one
embodiment, the first and
second ribs may be staggered such that the enlarged portions of the first rib
are vertically
centered in relation to the bridges of the second rib and the enlarged
portions of the second rib
are vertically centered in relation to the bridges of the first rib. In
another embodiment, all of the
plurality of ribs may be arranged in an alternating, staggered arrangement,
such that the enlarged
portions and the bridges of each rib are vertically offset from the enlarged
portions and the
bridges, respectively, of each adjacent rib, and such that the enlarged
portions and the bridges of
each rib are vertically centered in relation to the bridges and the enlarged
portions, respectively,
of each adjacent rib. The plurality of ribs may form a brick-like pattern in
this embodiment.
According to a further aspect, the enlarged portions of the ribs are generally
rectangular
in shape.
According to yet another aspect, the sidewall of the bottle has a generally
square cross-
section and is formed by four generally flat panels connected by four rounded
corners. The
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plurality of ribs are staggered, such that each rib of a first group of the
ribs has one of the
enlarged portions vertically aligned with each of the four corners, and each
rib of a second group
of the ribs has one of the bridges vertically aligned with each of the four
corners. In one
embodiment, the first group of ribs and the second group of ribs are arranged
in an alternating
arrangement.
According to a still further aspect, the bottle is manufactured using a blow
molding
process, from a material that includes at least some recycled PET, and is
capable of exhibiting a
dimensional stability of less than 1% dimensional change during a WAB steam
sterilization
process in which the bottle reaches temperatures in the range of 75-85 C.
Additional aspects of the invention relate to a bottle that includes a base
that forms a
lowermost surface of the bottle, an opening proximate a top of the bottle,
spaced vertically from
the base, configured to permit filling and emptying of the bottle, and a
sidewall extending
vertically upward at least a portion of a vertical distance from the base to
the opening. The
sidewall is formed by four generally flat panel sections connected by four
rounded corners. The
sidewall has a plurality of annular ribs extending around a periphery of the
sidewall. Each of the
annular ribs includes a plurality of sequential enlarged portions
interconnected by bridges, with
each of the enlarged portions having a vertical width that is greater than a
vertical width of each
of the bridges. A first rib of the plurality of ribs is staggered in relation
to at least one adjacent
second rib of the plurality of ribs, such that the enlarged portions of the
first rib are vertically
centered in relation to the bridges of the second rib and the enlarged
portions of the second rib
are vertically centered in relation to the bridges of the first rib, and such
that first rib has one of
the enlarged portions vertically aligned with each of the four corners and the
second rib has one
of the bridges vertically aligned with each of the four corners.
According to one aspect, the sidewall further includes recessed lands located
between the
annular ribs.
According to another aspect, all of the plurality of ribs are arranged in an
alternating,
staggered arrangement, such that the enlarged portions and the bridges of each
rib are vertically
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offset from the enlarged portions and the bridges, respectively, of each
adjacent rib to form a
brick-like pattern.
According to a further aspect, the enlarged portions of the ribs are generally
rectangular
in shape.
According to yet another aspect, all of the plurality of ribs are arranged in
an alternating,
staggered arrangement, such that the enlarged portions and the bridges of each
rib are vertically
centered in relation to the bridges and the enlarged portions, respectively,
of each adjacent rib,
and such that the plurality of ribs form an alternating pattern at each of the
four corners where
the enlarged portions and the bridges of alternating ribs are vertically
aligned with each
respective corner.
According to a still further aspect, the bottle is manufactured using a blow
molding
process, from a material that includes at least some recycled PET, and is
capable of exhibiting a
dimensional stability of less than 1% dimensional change during a WAB steam
sterilization
process where the bottle reaches temperatures in the range of 75-85 C.
Further aspects of the invention relate to a bottle that includes a neck
portion having an
opening configured to permit filling and emptying of the bottle, a shoulder
portion connected to a
lower end of the neck portion, a sidewall connected to the lower end of the
shoulder portion and
extending vertically downward from the shoulder portion, and a base connected
to a lower end of
the sidewall and forming a bottom surface of the bottle. The shoulder portion
has a tapered '
configuration that tapers from a narrower top end with a generally circular
cross-sectional shape
to a wider bottom end with a generally square cross-sectional shape, and the
sidewall has a
generally square cross-sectional shape formed by four generally flat panel
sections connected by
four rounded corners. The sidewall has a plurality of raised, annular ribs
extending around a
periphery of the sidewall. Each of the annular ribs includes a plurality of
sequential, generally
rectangular enlarged portions interconnected by bridges, each of the enlarged
portions having a
vertical width that is greater than a vertical width of each of the bridges.
The ribs are further
separated by recessed lands located between the ribs. All of the plurality of
ribs are arranged in
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an alternating, staggered arrangement, such that the enlarged portions and the
bridges of each rib
are vertically centered in relation to the bridges and the enlarged portions,
respectively, of each
adjacent rib, and such that the plurality of ribs form an alternating pattern
at each of the four
corners where the enlarged portions and the bridges of alternating ribs are
vertically aligned with
each respective corner.
According to one aspect, the bottle is manufactured using a blow molding
process, from a
material that includes at least some recycled PET, and is capable of
exhibiting a dimensional
stability of less than 1% dimensional change during a WAB steam sterilization
process where the
bottle reaches temperatures in the range of 75-85 C.
Still further aspects of the invention relate to a method of blow molding a
bottle as
described above, and a method of sterilizing a bottle as described above. The
method of
sterilizing may include conducting a WAB steam sterilization process on the
bottle, which
process reaches temperatures in the range of 75-85 C. The bottle may exhibit a
dimensional
stability of less than 1% dimensional change during the WAB steam
sterilization process.
Other features and advantages of the invention will be apparent from the
following
specification taken in conjunction with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
To allow for a more full understanding of the present invention, it will now
be described
by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a bottle;
FIG. 2 is a front view of the bottle of FIG. 1;
FIG. 3 is a right view of the bottle of FIG. 1;
FIG. 4 is a rear side view of the bottle of FIG. 1;
FIG. 5 is a left side view of the bottle of FIG. 1;
FIG. 6 is a top view of the bottle of FIG. 1;
FIG. 7 is a bottom view of the bottle of FIG. 1;
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FIG. 8 is a graph illustrating the heatflow of PET and HDPE over a temperature
range;
and
FIG. 9 is a graph illustrating the modulus of PET and HDPE over a temperature
range.
DETAILED DESCRIPTION
In the following description of various example structures according to the
invention,
reference is made to the accompanying drawings, which form a part hereof, and
in which are
shown by way of illustration various example devices, systems, and
environments in which
aspects of the invention may be practiced. It is to be understood that other
specific arrangements
of parts, example devices, systems, and environments may be utilized and
structural and
functional modifications may be made without departing from the scope of the
present invention.
Also, while the terms "top," "bottom," "front," "back," "side," "rear," and
the like may be used in
this specification to describe various example features and elements of the
invention, these terms
are used herein as a matter of convenience, e.g., based on the example
orientations shown in the
figures or the orientation during typical use. Additionally, the term
"plurality," as used herein,
indicates any number greater than one, either disjunctively or conjunctively,
as necessary, up to
an infinite number. Nothing in this specification should be construed as
requiring a specific
three dimensional orientation of structures in order to fall within the scope
of this invention.
FIGS. 1-7 illustrate an exemplary embodiment of a bottle 10 according to
aspects of the
present invention. The bottle 10 includes a neck 12, a shoulder portion 14, a
sidewall 16, and a
base 18. The bottle 10 is generally square / rectangular in cross-section, and
the sidewall 16 is
defined by four generally flat panels 20 connected by rounded corners 22.
The neck 12 has a circular opening 11 for filling and emptying the bottle 10
(see FIG. 6),
and is threaded for attachment of a cap (not shown) thereto, as is known in
the art. The neck 12
also includes a flange 13 for supporting a cap ring (not shown) as also known
in the art. In other
embodiments, the features of the bottle 10, including the structure of the
sidewall 16, can be
utilized in bottles that have different types and configurations of openings
for filling and
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emptying, as well as different types and configurations of closures for such
openings, including
flip-top lids, snap lids, peel-back lids, other types of lids, and/or
combinations of such. For
example, in one embodiment, the bottle 10 may include a peel-back portion in
addition to the
threaded cap. As another example, a bottle may have an opening that is not
located at the top of
the bottle, such as by having an opening in a side surface of the bottle.
The shoulder portion 14 expands the diameter of the bottle 10 from the
narrower neck 12
to the wider sidewall 16. The shoulder portion 14 also creates a gradual
transition from a round
cross-section to the square / rectangular cross-section of the sidewall 16.
The lower end 14A of
the shoulder portion 14 is generally square in cross-section, having four
flattened areas 15, and
has at least one greater cross-sectional dimension than the sidewall 16. Each
of the flattened
areas 15 of the shoulder portion 14 is located directly above one of the
panels 20 of the sidewall
16, described below. In this embodiment, the lower end 14A of the shoulder
portion 14, at the
flattened areas 15, has a greater cross-sectional width, a greater cross-
sectional perimeter, and a
greater cross-sectional area measured perpendicular to the vertical axis of
the bottle 10, relative
to the sidewall 16. In other embodiments, the features of the bottle 10,
including the structure of
the sidewall 16, can be utilized in bottles that have a differently-configured
shoulder portion 14,
or that have no identifiable shoulder portion.
The base 18 is located at the lower end of the sidewall 16, and includes a
generally
vertical, upstanding portion 51 and a bottom surface 50 forming the lowermost
surface of the
bottle 10. The base 18 also has a generally square / rectangular cross-
section, having four
flattened areas 19, and also has at least one greater cross-sectional
dimension than the sidewall
16. Each of the flattened areas 19 of the base 18 is located directly below
one of the panels 20 of
the sidewall 16, described below. In this embodiment, the upstanding portion
51 of the base 18,
at the flattened areas 19, has a greater cross-sectional width, a greater
cross-sectional perimeter,
and a greater cross-sectional area measured perpendicular to the vertical axis
of the bottle 10,
relative to the sidewall 16. The base 18 also includes a base shoulder 17 that
transitions from the
upstanding portion 51 to the bottom surface 50 of the bottle 10. The bottom
surface 50 has a
generally circular recess 52 with a curvilinear profile and a plurality of
strengthening ribs 54
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arranged in a radial formation at the center of the recess 52. In other
embodiments, the features
of the bottle 10, including the structure of the sidewall 16, can be utilized
in bottles that have a
differently-configured base, or that have no identifiable base below the
sidewall.
The sidewall 16 is recessed from the shoulder portion 14 and the base 18, and
has
generally smaller cross-sectional dimensions in this embodiment. As described
above, the
sidewall 16 is generally square / rectangular in cross-section, having four
generally flat panels 20
connected by rounded corners 22. The upper and lower ends of the sidewall 16
each include an
annular shelf 24 forming transitions from the shoulder portion 14 and the base
18 to the recessed
lands 28 of the sidewall 16, with each annular shelf 24 having a generally
smooth outer surface
that follows the contours of the panels 20 and corners 22. Each annular shelf
24 is separated
from the shoulder portion 14 or the base 18, respectively, by a first annular
shoulder 24A that
forms a reduction in cross-sectional area from the shoulder portion 14 or the
base 18 to the
respective shelf 24. Further, each annular shelf 24 is separated from the
recessed lands 28 of the
sidewall 16 by a second annular shoulder 24B that forms a reduction in cross-
sectional area from
the respective shelf 24 to the adjacent recessed lands 28 of the sidewall 16.
The sidewall 16 also includes a plurality of annular ribs 26 extending around
the
perimeter of the bottle 10, formed as raised or embossed segments of the
sidewall 16. The ribs
26 extend across each of the flat panels 20 and around each of the corners 22.
The ribs 26 are
separated by recessed lands 28, and the ribs 26 are raised with respect to the
lands 28. In the
embodiment illustrated in FIGS. 1-7, the lands 28 are completely separated
from each other by
the ribs 26. Each of the ribs 26 is formed in a brick-like configuration,
having a plurality of
sequential enlarged portions or brick portions 30 separated by narrower
bridges 32. In the
embodiment shown, the enlarged portions 30 are each formed in a generally
rectangular
configuration. However, in other embodiments, the enlarged portions 30 may
have a different
shape, including a square, tapered, or rounded shape. Additionally, the
bridges 32 may have
different configurations in other embodiments, such as a narrower or wider
configuration.
Alternately, the bridges 32 may be only intermittently present, such that one
of the ribs 26 may
have complete gaps or separations between two or more adjacent enlarged
portions 30, and in
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one embodiment, the bridges 32 may be completely absent for one or more of the
ribs 26. In
such embodiments, at least some of the lands 28 may not be completely
separated from each
other. In another embodiment, additional vertical bridges may exist between
two or more of the
ribs 26 on the sidewall 16. In a further embodiment, the orientation of the
embossed ribs 26 and
the recessed lands 28 may be reversed, with the ribs 26 being recessed into
the outer surface of
the sidewall 16 and the lands 28 being raised above the ribs 26.
In the embodiment shown in FIGS. 1-7, the ribs 26 are arranged in an
alternating,
staggered formation, such that adjacent ribs 26 are offset from each other. In
other words, the
enlarged portion 30 of a first rib 26A is offset from the enlarged portions 30
of the upper and/or
lower adjacent ribs 26B, 26C, as shown in FIG. 2. In the embodiment
illustrated, the bridges 32
of the first rib 26A are located in vertical alignment with the approximate
midpoints of the
enlarged portions 30 of the adjacent ribs 26B, 26C. Likewise, the bridges 32
of the adjacent ribs
26B, 26C are located in vertical alignment with the approximate midpoints of
the enlarged
portions 30 of the first rib 26A. Further, in this embodiment, the midpoints
of the enlarged
portions 30 and the bridges 32 of alternating ribs 26 are centered at the
midpoints of each of the
rounded corners 22, as best seen in FIG. 1. It is understood that the bottle
10 is shown as a thin-
wall, blow molded bottle 10, and that the internal surfaces of the bottle 10
are generally mirror-
images of the external surfaces. It is also understood that features of the
bottle 10 may be useful
in other types of bottles, such as bottles having thicker walls.
Viewed another way, the sidewall 16 may be described as having an arrangement
of
staggered ribs 26, such that the ribs 26 form an alternating pattern at each
of the four corners 22
where the enlarged portions 30 and the bridges 32 of alternating ribs 26 are
vertically aligned
with each respective corner 22. In one embodiment, the enlarged portions 30 of
a first group of
the ribs 26 (e.g. 26A) are vertically aligned with each of the four corners
22, and the bridges 32
of a second group of the ribs 26 (e.g. 26B, 26C) are vertically aligned with
each of the four
corners 22. The first and second groups of ribs 26 may be arranged in an
alternating pattern, as
described above. Such an alternating pattern may be described as an A-B-A-B
repeating pattern,
with "A" signifying said first group of ribs 26 (e.g. 26A) and "B" signifying
said second group
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of ribs 26 (e.g. 26B, 26C). In another embodiment, the ribs 26 may be arranged
in an alternating
pattern, but each rib 26 may not have only bridges 32 or enlarged portions 30
aligned with the
corners 22. For example, each rib 26 may have two bridges 32 aligned with two
of the corners
22 and two enlarged portions 30 aligned with the other two corners 22, in
alternating
arrangement. In this embodiment, each corner 22 will still have an alternating
bridge 32 /
enlarged portion 30 pattern progressing vertically down the corner 22, with
opposite corners 22
having identical alternating patterns and adjacent corners 22 having opposite
alternating
patterns 22.
The degree of offset or staggering of the ribs 26 can be different in other
embodiments.
For example, in one embodiment, the sidewall 16 may include three or four
different staggered
rib configurations, such that the ribs 26 alternate in an A-B-C-A-B-C pattern
or an A-B-C-D-A-
B-C-D pattern, among other embodiments. In a further embodiment, the ribs 26
may not be
staggered or offset from each other, or may be randomly staggered on the
sidewall 16.
The sidewall 16 is also configured to have a label (not shown) attached
thereto. The
large, flat surface area provided by the plurality of enlarged portions 30 of
the ribs 26 and the
surfaces of the annular shelves 24 provide sufficient area for attachment of
such a label, for
example by using an adhesive.
The bottle 10 is suitable for manufacture by blow molding processes, including
stretch
blow molding processes, but can also be manufactured using other processes.
Additionally, the
bottle 10 is suitable for use with PET and/or rPET materials, but can provide
beneficial effects
when manufactured from other materials, including HDPE and other polymer
materials. Further,
the bottle 10 is suitable for use for steam sterilization processes, including
processes utilizing a
WAB peroxide steam rinser, but can provide benefits in other applications as
well. Still further,
the bottle 10 is suitable for use in cold-fill applications, but may also be
useful in hot-fill
applications, as well as other applications.
The structural features of the bottle 10 shown in FIGS. 1-7, including at
least the
structure of the ribs 26 and/or other structures of the sidewall 16, provide
sufficient strength and
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,
stability to the bottle 10 to enable the bottle 10 to be used in a steam
sterilization process without
unacceptable deformation of the bottle 10. In particular, the structure
enables a bottle 10 made
of PET (including rPET) be used in steam sterilization processes where the
bottle 10 reaches
temperatures in the range of 75-85 C. Prototypes of one embodiment of the
bottle 10 made
using at least some rPET have exhibited dimensional stability of less than 1%
dimensional
change during a steam sterilization process. Additionally, steam sterilization
processes carried
out on prototypes of the bottle 10 have shown superior bacteria kill rates
during steam
sterilization processes. It is thought that the internal geometry of the
bottle 10 may cause
increased turbulence of the sterilizing medium within the bottle 10, which may
produce a greater
kill rate than in other bottles.
While the invention has been described with respect to specific examples
including
presently preferred modes of carrying out the invention, those skilled in the
art will appreciate
that there are numerous variations and permutations of the above described
systems and
methods. The scope of the claims should not be limited by the preferred
embodiments set forth
in the examples, but should be given the broadest interpretation consistent
with the description as
a whole.
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