Patent Application
20220324604
This application relates to a container for a liquid, and in particular to a retortable, lightweight plastic container for a liquid.
Some products, such as comestible, beverage, nutritional, and pharmaceutical products, may require sterilization when packaged in a container. In some applications, the products are sterilized after filling and sealing the container. This process is known as retort sterilization or retort packaging. Typically, in these applications, the container is filled with a product, typically at or near ambient temperature, and then sealed. The liquid filled container is then exposed to heat and pressure for a period of time sufficient to sterilize the product and the interior of the container.
Retort sterilization of plastic containers, as opposed to glass or metal, requires additional considerations regarding the pressures and temperatures the plastic containers are exposed to during the retort process. For example, during retort sterilization, the increased temperature of the filled product creates a positive internal pressure inside the container. Further, plastic containers have a tendency to become weaker at the high sterilization temperatures. Thus, the plastic container and/or the retort process must be configured to ensure the container withstands the pressures and temperature of retort sterilization without resulting in catastrophic failure or permanent deformation of the container.
A plastic container having a volume capacity, according to one aspect of the present disclosure, includes an upper portion having an annular groove and a reclosable and resealable open top end, a base portion closing off an end of the container, and an intermediate portion being integrally formed with and exiting from the upper portion to the base portion. The intermediate portion includes a plurality of horizontal ribs arranged substantially perpendicular to a longitudinal axis of the container with at least one of the horizontal ribs being disposed longitudinally between an upper land and a lower land. The plastic container has a volume capacity is 220 ml. or greater and a plastic weight of 20 g or less. At least one of the horizontal ribs as a horizontal rib depth of at least 4.5 mm and a horizontal rib width to horizontal rib depth ratio of between 2.2 to 2.7.
A ribbed portion of a plastic container, according to another aspect of the present disclosure, includes an alternating series of horizontal lands and horizontal ribs, including a first land having a first land width, a first rib having a first rib width and a first rib depth, a second land and having a second land width, and a second rib having a second rib width and a second rib depth. The first rib depth is at least 4.5 mm and the first rib width to first rib depth ratio is between 2.2 to 2.7.
Features and advantages of the general inventive concepts will become apparent from the following detailed description made with reference to the accompanying drawings.
Disclosed herein is a plastic container for storing a liquid, such as a comestible, beverage, nutritional, or pharmaceutical product. While the present disclosure describes certain embodiments of the plastic container in detail, the present disclosure is to be considered exemplary and is not intended to be limited to the disclosed embodiments. Also, certain elements or features of embodiments disclosed herein are not limited to a particular embodiment, but instead apply to all embodiments of the present disclosure.
The terminology as set forth herein is for description of the embodiments only and should not be construed as limiting the disclosure as a whole. All references to singular characteristics or limitations of the present disclosure shall include the corresponding plural characteristic or limitation, and vice versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made. Unless otherwise specified, “a,” “an,” “the,” and “at least one” are used interchangeably. Furthermore, as used in the description and the appended claims, the singular forms “a,” “an,” and “the” are inclusive of their plural forms, unless the context clearly indicates otherwise.
To the extent that the term “includes” or “including” is used in the description or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. Furthermore, when the phrase “one or more of A and B” is employed it is intended to mean “only A, only B, or both A and B.”
The plastic container of the present disclosure can comprise, consist of, or consist essentially of the essential elements of the disclosure as described herein, as well as any additional or optional element or feature described herein or which is otherwise useful in plastic container applications.
All ranges and parameters, including but not limited to dimensions, percentages and ratios, disclosed herein are understood to encompass any and all sub-ranges assumed and subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less (e.g., 1 to 6.1, or 2.3 to 9.4), and to each integer (1, 2, 3, 4, 5, 6, 7, 8, 9, and 10) contained within the range.
Unless otherwise indicated, all numbers expressing dimensions or properties of the container, temperatures, pressure, or other properties as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the suitable properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the general inventive concepts are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements. In general, the term “about” modifies a numerical value above and below the stated value by 10%.
The disclosed plastic container is configured to be suitable for retort sterilization without failing while utilizing less plastic material that conventional retortable plastic containers of similar volume capacity. The plastic container may be suitable for other high-temperature processes, such as for example, hot-fill processing or other thermal processes. The term “retort sterilizing” and “retort packaging” may be used interchangeably herein, and unless otherwise specified, refer to the practice of filling a container with a liquid and then subjecting the liquid-filled container to the necessary heat sterilization step, to form a sterilized, retort packaged, liquid product.
The temperature and pressure which the plastic container is exposed to during retort sterilization, as well as the duration of exposure, may vary in different retort sterilizing processes. Retort processing typically exposes the exterior of the plastic container to temperatures from 110° C. to 135° C., with an over pressure of up to 50 psi applied in the plastic container. The total processing time (including heat up to cook temperature, hold at cook temperature, and cool down) can vary widely (e.g., 30 minutes to 2 hours or more) depending on the packaging configuration and food properties.
Referring to
In one exemplary embodiment, the container 10 is a one-piece plastic container from a single or multiple layer material. The container 10 may be made by any suitable manufacturing method, such as injection-stretch blow molding or extrusion blow molding, and may be made from any suitable thermoplastic materials or combination of materials that satisfy the specifications of the present invention including plastics such as polypropylene, high density polyethylene, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and other suitable thermoplastics. It should be understood that the type of thermoplastic material used can impact performance of the container 10 during retort sterilization due to the different properties of different thermoplastics. In the illustrated embodiment, the plastic container 10 is made of polypropylene.
Similar to the type of plastic being used, the amount of plastic used in the container can impact the performance of the container during retort sterilizing, since lower amounts of plastics tend to result in thinner wall thickness. In some exemplary embodiments, the plastic container 10 is manufactured as a lightweight container, having a volume capacity of at least 200 ml (7.44 fl. oz.), such as for example, at least 8 fl. oz. (236.6 ml), while being made from less than 20 grams of plastic, or less than 19 grams of plastic, or less than 18 grams of plastic, or less than 17 grams of plastic. As used in this disclosure, the amount of plastic used in the container refers to the amount of plastic used to make the bottle, excluding the amount of plastic in the cap or closure.
In the illustrated embodiment, the container 10 includes a body 12 having a substantially cylindrical cross section extending along a longitudinal axis A. 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, hexagonal, octagonal or square shaped containers, which may have different dimensions and volume capacities. It is also contemplated that other modifications can be made depending on the specific application and requirements. The body 12 has a height HT and defines an interior space 14 for storing the liquid. The interior space 14 defines the volume capacity of the container 10.
In the illustrated embodiment, the body 12 includes an upper portion 16 having an open top end 18 for providing access to the interior space 14. Integrally formed with the upper portion 16 and extending downward therefrom may be a shoulder portion 20 that provides a transition between the upper portion 16 and an intermediate portion 22 that defines a ribbed portion of the container 10. The upper portion 16 has a width WU from the open top end 18 to the shoulder portion 20. The intermediate portion 22 is integrally formed with and extends downward from the shoulder portion 20 to a base portion 24. The intermediate portion has a width WI from the shoulder portion 20 to the base portion 24 and has a diameter D1. The base portion 24 has a closed bottom end 26 and a width WB.
In the illustrated embodiment, the upper portion 16 includes a continuous external thread 28 adjacent the open top end 18 for releasably connecting to a similarly threaded closure or cap (not shown). The closure or cap (not shown) can define at least one thread formed around an inner diameter for cooperatively mating with the external thread 28 of the upper portion 16. In other embodiments, the upper portion 16 may include a plurality of external threads and/or the upper portion 16 may include other types of connections for releasably connecting the closure (not shown) to the upper portion 16.
The closure or cap (not shown) engages the upper portion 16 to preferably provide a hermetic seal of the plastic container 10. The closure or cap (not shown) is preferably made of a plastic material conventional to the closure industry and suitable for subsequent thermal processing, including high temperature pasteurization and retort sterilization. In yet another embodiment, the upper portion 16 may be free from structures and components for releasably connecting the cap or closure (not shown) to the upper portion 16.
The upper portion 16 may also include an upper circumferential ring 30 and a lower circumferential ring 32, axially spaced apart from the upper circumferential ring 30. The upper circumferential ring 30 and the lower circumferential ring 32 are positioned below the external thread 28. The lower circumferential ring 32 may facilitate gripping of the container 10 by a filling machine during an automated filling operation. In other embodiments, the upper portion 16 may include other components for facilitating gripping of the bottle by a filling machine. It is understood that the upper portion 16 may be free from components and structures for facilitating gripping of the container 10 by a filling machine.
The upper portion 16 may also include texturing, such as one or more ratcheted and/or knurled regions 34 that extend partially or completely around the upper portion 16. The one or more ratcheted regions 34 may be configured in a variety of ways. In the illustrated embodiment, two ratcheted regions 34 are positioned between the upper circumferential ring 30 and the lower circumferential ring 32 on opposite sides of the upper portion 16. Each of the ratcheted regions 34 have four, equally spaced-apart, straight vertical ridges. In other exemplary embodiments, the one or more ratcheted regions 34 may include more or less than four ridges, the ridges may be unevenly spaced apart and/or located other than between the upper circumferential ring 30 and the lower circumferential ring 32 and/or opposite of each other. In addition to, or in the alternative, other suitable forms of texturing may be used as would be apparent to one of ordinary skill in the art in view of the teachings herein.
The one or more ratcheted regions 34 may provide a better grip when a user grasps the container 10, may serve as an interface to engage machinery and/or other devices, which may be involved, for instance, in the manufacturing, filling, and/or closing of container 10, and/or may serve as a tactile indicator to a user while turning the cap or closure (not shown).
Below the lower circumferential ring 32, the shoulder portion 20 extends downward while expanding outward (i.e., increasing in cross sectional diameter) to transition to the intermediate portion 22. In the exemplary embodiment, the shoulder portion 20 may include an optional annular groove 36 for use in packaging of multiple bottles in a multipack carrier, such as for example, a Hi-Cone™ plastic carrier. The annular groove 36 may be configured in a variety of ways. Any groove or recess capable of facilitating the use of a multipack carrier to bundle multiple bottles together may be used. In the illustrated embodiment, the annular groove 36 is positioned adjacent the intermediate portion 22. In other embodiments, however, the container 10 may not have the annular groove 36 or the annular groove 36 may be positioned other than adjacent the intermediate portion 22, such as for example, in the shoulder portion 20 closer to the upper portion 16.
In the illustrated embodiment, the annular groove 36 has a width WG and is defined by a constant inner radius RGI. In other embodiments, however, the inner radius RGI may not be constant. The annular groove 36 includes an upper outer radius RGU and a lower outer radius RGL. In the illustrated embodiment, the annular groove 36 is symmetric such that the upper outer radius RGU is equal to the lower outer radius RGL. In other embodiments, however, the annular groove 36 may be asymmetric and the upper outer radius RGU and the lower outer radius RGL may differ.
The intermediate portion 22 may extend continuously in a vertical direction from the shoulder portion 20 to the base portion 24. The intermediate portion 22 is defined by one or more horizontal lands 40 and one or more horizontal ribs 42. In some embodiments, the intermediate portion 22 includes a series of alternating horizontal lands 40 and horizontal ribs 42. The number and arrangement of the horizontal lands 40 and the horizontal ribs 42, however, may vary in different embodiments. For example, in the illustrated embodiment, the container 10 includes two horizontal lands 40 and two horizontal ribs 42. In other embodiments, however, the container 10 may include more or less than two horizontal lands 40 and/or two horizontal ribs 42.
In the illustrated embodiment, the intermediate portion 22 includes a first rib 44, a first land 46 extending between the annular groove 36 and the first rib 44, a second rib 48 spaced apart from the first rib 44, and a second land 50 extending between the first rib 44 and the second rib 48. In the illustrated embodiment, the first land 46 is generally flat in vertical cross-section, extends around the entire circumference of the body 12, and extends substantially parallel to the longitudinal axis A from the annular groove 36 to the first rib 44. In other embodiments, however, the first land 46 may not extend around the entire circumference and/or may extend at an angle relative to the longitudinal axis A. The first land 46 has a width WL1.
Similar to the first land 46, the second land 50 is generally flat in vertical cross-section, extends around the entire circumference of the body 12, and extends substantially parallel to the longitudinal axis A between the first rib 44 and the second rib 48. In other embodiments, however, the second land 50 may not extend around the entire circumference and/or may extend at an angle relative to the longitudinal axis A. The second land 50 has a width WL2. In one exemplary embodiment, the width WL2 of the second land 50 is greater than the width WL1 of the first land 46. In other embodiments, however, the width of WL1 of the first land 46 may be greater or equal the width WL2 of the second land.
The first rib 44 and the second rib 48 are inward extending and are configured to provide sufficient hoop strength to the container 10 and be deformable (i.e., axially expandable and axially compressible) to provide sufficient volume compensation such that the container 10 does not experience a failure during retort sterilization. The ribs 44, 48 may be configured in a variety of ways. For example, in different embodiments, the ribs 44, 48 may have different widths, depths, wall angles, inner radius, upper outer radius, and lower outer radius.
In the illustrated embodiment, the first rib 44 and the second rib 48 are identical in configuration. Therefore, only the configuration of first rib 44 will be described in detail since the description of the first rib 44 applies equally to the second rib 48. In other embodiments, however, the second rib 48 may be configured differently that the first rib 44. For example, one or more of the width, depth, wall angle, innermost radius, upper outer radius and lower outer radius may be different for the second rib 48 as compared to the first rib 44.
Referring to
The first rib 44 also include an upper outer radius RU1 between the first land 46 and the upper sidewall 60 and a lower outer radius RL1 between the lower sidewall 62 and the second land 50. The width WR1 is measured from the upper extent of the upper outer radius RU1 to the lower extent of the lower outer radius RL1. In the illustrated embodiment, the upper outer radius RU1 is equal to the lower outer radius RL1. In other embodiments, however, the first rib 44 may be asymmetric. Thus, for example, in some embodiments, the upper sidewall 60 may taper at a different angle than the lower sidewall 62 and the upper outer radius RU1 and the lower outer radius RL1 may differ.
In the illustrated embodiment, the base portion 24 is integrally formed with and extends downward from the intermediate portion 22. The base portion 24 may be defined by a generally flat sidewall 66; thus, the base portion 24, in the illustrated embodiment, is free of horizontal ribs. The sidewall 66 tapers inward at an angle α, relative to vertical, from the intermediate portion 22 to the closed bottom end 26. Thus, the closed bottom end 26 has a diameter D2 that is less than the diameter D1 of the intermediate portion 22. In other embodiments, however, the sidewall 66 may be generally parallel to the longitudinal axis A (no taper) or may taper outward.
The closed bottom end 26 may be configured in a variety of ways. In the illustrated embodiment shown in
In the illustrated embodiment, the wall thickness profile of the container 10 is representative of a typical extrusion blow molded bottle. Those skilled in the art would readily understand that for a given bottle with a given surface area, plastic weight of the container translates to a volume of plastic (depending on density) that will yield certain wall thickness ranges.
Table 1 illustrates non-limiting dimensions and ranges for an exemplary embodiment of an unfilled, 8 fl. oz. (236.6 ml) container according the present disclosure. It will be understood that the dimensions may vary in different embodiments of the container. For example, an exemplary range for the dimensions in Table 1 for a container according the present disclosure may be plus or minus 15% of the dimension value listed for Embodiment 1, or plus or minus 10% of the dimension, or plus or minus 5% of the dimension. Thus, for example, in some embodiments, the depth of the first rib DR1 may be in the range of 0.158 inches to 0.214 inches (4.01 mm to 5.44 mm).
Table 3 illustrates computer simulation results for three different plastic container designs under pressure and vacuum loading. The first design (“design 1”) is a known 8.0 oz., 22 g polypropylene, retortable bottle design. As shown in
The second design (“design 2”) corresponds to the hot-fill, horizontal ribbed bottle designs disclosed in U.S. Pat. No. 8,496,130 (“the '130 patent”), shown in
As shown in
The third design (“design 3”) is the exemplary embodiment of the disclosed container having the dimensions illustrated in Table 1 for Embodiment 1 at the same three different bottle weights.
For the purpose of this modeling comparison, all three bottle designs used the same wall thickness profile and all of the containers were modeled as 8 fl. oz. (236.6 ml), polypropylene bottles. The bottle polypropylene has a material density of 0.9 g/cc and temperature dependent stress-strain curves as shown in Table 2.
Paneling vacuum at room temperature refers to the amount of negative internal pressure in the container at the onset of paneling deformation of the container at room temperature and external atmospheric pressure. Volume compensation at onset of paneling at room temperature refers to the change in internal volume of the container at the paneling vacuum in cubic centimeters. Pressure stiffness at 250° F. (121.1° C.) refers to the ability of the bottle geometry (and wall thickness) to resist deformation and maintain shape integrity under high temperature and positive internal pressure conditions experienced during retort processing. Thus, the pressure stiffness refers to the amount of positive pressure per volume in the container when the container loses shape integrity.
As shown in Table 3, both the Design 2 containers and the Design 3 containers have a paneling vacuum that is equal to or greater than the paneling vacuum of the Design 1 container. In particular, both the Design 2 (17 g) container and the Design 3 (17 g) container deform (i.e., “panel”) at 68.9 kPa (10 psig), which is the same paneling vacuum as the Design 1 (22 g) container, while the Design 2 (22 g) container and the Design 3 (22 g) container panel at 103.4 kPa (15 psig), and 124.1 kPa (18 psig), respectively.
During simulation, the Design 3 containers deformed in the base portion 24 below the second rib 48, while the Design 2 containers deformed within the ribbed portion of the container. As a result, based on the deformation shape and stresses, the paneling deformation is likely to recover fully for the Design 3 containers once the vacuum reduces below the paneling vacuum. Conversely, Design 2 containers showed pinches and dents at the paneling area. Based on the deformation shape and stresses, some of the pinches, dents, or even the overall paneling shape will likely remain and not fully recover once the vacuum drops below the paneling vacuum.
Regarding volume compensation, as compared to the Design 1 container, the Design 3 containers have a lower volume compensation while the Design 2 containers have a higher volume compensation at the onset of the paneling. The change of the volume compensation, however, is small relative to the package headspace of approximately 25.14 ml (0.85 oz.)
Regarding pressure stiffness, both the Design 2 (22 g) container and the Design 3 (22 g) container are stiffer than the Design 1 (22 g) container. In particular, the Design 2 (22 g) container has a pressure stiffness of 0.70 kPa/ml (7.1 psig/oz.) and the Design 3 (22 g) has a pressure stiffness of 1.09 kPa/ml (11.1 psig/oz.) as compared to the Design 1 (22 g) container, which has a pressure stiffness of 0.58 kPa/ml (5.9 psig/oz.). For the Design 2 (17 g) container and the Design 3 (17 g) container, the Design 2 (17 g) container's pressure stiffness is worse than the pressure stiffness of the Design 1 (22 g) container 0.42 kPa/ml vs. 0.58 kPa/ml (4.3 psi/oz. vs. 5.9 psi/oz.), respectively, while the pressure stiffness of the Design 3 (17 g) container is better than the pressure stiffness of the Design 1 (22 g) container 0.68 kPa/ml vs. 0.58 kPa/ml (6.9 psi/oz. vs. 5.9 psi/oz.), respectively. Thus, at lower bottle weights, such as below 19 g, below 18 g, or below 17 g, the Design 2 container may not be suitable for retort processing. Conversely, even at lower bottle weights, such as below 19 g, below 18 g, or below 17 g, the Design 3 container have superior pressure stiffness to the Design 1 container of the same volume capacity.
The container 10, as described above and shown in the modeled data, is suitable for storing a liquid and undergoing retort sterilization without failure while utilizing less plastic material that conventional retortable plastic containers of similar volume capacity.
Unless otherwise indicated herein, all sub-embodiments and optional embodiments are respective sub-embodiments and optional embodiments to all embodiments described herein. While the present disclosure has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the present disclosure, in its broader aspects, is not limited to the specific details, the representative compositions or formulations, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicant's general disclosure herein.
This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/904,961, filed Sep. 24, 2019, the entire content of which is incorporated by reference herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/052502 | 9/24/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62904961 | Sep 2019 | US |
