CA2909856C

CA2909856C - Bottle and method of sterilization

Info

Publication number: CA2909856C
Application number: CA2909856A
Authority: CA
Inventors: Bryan J. Lembke; Raymond A. Pritchett, Jr; Matthew A. Russell
Original assignee: Tropicana Products Inc; Graham Packaging Co LP
Current assignee: Tropicana Products Inc; Graham Packaging Co LP
Priority date: 2009-05-15
Filing date: 2010-05-17
Publication date: 2019-08-20
Anticipated expiration: 2030-05-17
Also published as: CA2909856A1; US20110049085A1; CA2704333A1; CA2704333C

Abstract

A bottle 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.

Description

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.

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

2 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

3 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

4 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;

5 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

6 =
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

7 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

8 =
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

9 =
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 , 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.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A bottle comprising:
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, wherein the sidewall of the bottle has a generally square cross-section and is formed by four generally flat panels connected by four rounded comers; and a base connected to a lower end of the sidewall and forming a bottom surface of the bottle, wherein the sidewall comprises a plurality of annular ribs extending around a periphery of the sidewall, each of the annular ribs comprising a plurality of sequential enlarged portions horizontally interconnected by bridges, each of the enlarged portions having a vertical width that is greater than a vertical width of each of the bridges.

2. The bottle of claim 1, wherein the sidewall further comprises recessed lands located between the annular ribs.

3. The bottle of claim 2, wherein the enlarged portions and the bridges of each of the annular ribs form a raised surface with respect to the recessed lands.

4. The bottle of any one of claims 1 to 3, wherein 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.

5. The bottle of claim 4, wherein the WAB steam sterilization process reaches temperatures in the range of 75-85°C.

6. The bottle of any one of claims 1 to 5, wherein the enlarged portions of the ribs are generally rectangular in shape.

7. The bottle of claim 1, wherein each of the bridges is formed by opposing "U" shapes in top and bottom edges of the annular ribs, wherein each of the enlarged portions of the ribs is defined by a top edge and a bottom edge, wherein the top edges of the enlarged portions of a first one of the ribs define a first plane and the bottom edges of the enlarged portions of a second one of the ribs define a second plane, wherein the entire bottom edge of the second rib is located above the first plane and the entire top edge of the first rib is located below the second plane, wherein the first rib and the second rib are immediately adjacent.