Retort panel for container

Abstract

A method of forming, filling, and sterilizing a container. Panels of the container are tapered inward on opposite sides from both a top and a bottom to a vertical mid-point. Columns are between the panels and are further from an axial center of the container than the panels. The method includes: filling the container with a product at ambient temperature or colder; closing the container with a cap; sterilizing the product by pressurizing an exterior of the container and heating both the container and the product to cause panels and columns of the container to expand from an as-blown position outward from the axial center of the container; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the panels and the columns to retract inward towards the axial center to the as-blown position or closer to the axial center.

Description

Attorney Docket No. 8330-000743-WO-POARETORT PANEL FOR CONTAINERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 730,512, filed on December 11 , 2024. The entire disclosure of the above application is incorporated herein by reference.FIELD

[0002] The present disclosure relates to a polymeric container including a body with a panel configured to withstand a retort process.BACKGROUND

[0003] This section provides background information related to the present disclosure, which is not necessarily prior art.

[0004] Container retort is a process used in the food industry to sterilize food after it has been packed into its container and sealed airtight. Retort involves subjecting the container to high temperatures and pressure in an autoclave or retort machine. This allows the food to be heated above the boiling point of water, typically between 1 16-130°C, thereby ensuring that it is commercially sterile.

[0005] While existing containers are suitable for their intended use, they are subject to improvement. The present disclosure includes new polymeric containers that have numerous advantages and unexpected results, as explained in detail herein and as one skilled in the art will appreciate.SUMMARY

[0006] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0007] The present disclosure provides for, in various features, a method of forming, filling, and sterilizing a container. The method includes: forming the container by blow molding, the container including a finish defining an opening, a base, and a body. The body includes: panels spaced apart around the body, each one of the panels extending vertically and tapered inward on opposite sides from both a top and a bottom to a vertical mid-point thereof; and columns extending vertically and spaced apart around the body, each of the columns is between two of the spaced apart panels and furtherAttorney Docket No. 8330-000743-WO-POA from an axial center of the container than the panels. The method further includes: filling the container with a product at ambient temperature or colder; closing the container with a cap; sterilizing the product by pressurizing an exterior of the container and heating both the container and the product to cause the panels and the columns to expand from an as-blown position outward from the axial center of the container; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the panels and the columns to retract inward towards the axial center to the as-blown position or closer to the axial center.

[0008] In further features, sterilizing the product includes placing the container with the product therein into a pressure vessel, and introducing steam into the pressure vessel to increase pressure and temperature within the pressure vessel.

[0009] In further features, the method includes increasing the temperature within the pressure vessel to up to 124°C.

[0010] In further features, the method includes increasing pressure within the pressure vessel up to 40 PSI at sea level.

[0011] In further features, the method includes creating a pressure within the container of -6 PSI to 6 PSI.

[0012] In further features, the method includes forming the container from polypropylene.

[0013] In further features, the method includes forming the container with a first stiffening rib above the columns and a second stiffening rib below the columns.

[0014] In further features, the panels are horizontally convex and vertically concave relative to an exterior of the container.

[0015] In further features, the columns have opposing concave borders, and the columns are further from the axial center than the panels.

[0016] In further features, cooperation between curved portions of the panels and straight portions of the columns provides the panels with an hour-glass shape at an exterior of the container.

[0017] In further features, the container includes only five of the panels and only 5 of the columns.

[0018] In further features, the container is made of one of polypropylene and polyethylene.

[0019] In further features, the container is formed by a one-step or extrusion blow molding process.Attorney Docket No. 8330-000743-WO-POA

[0020] The present disclosure further provides for, in various features, a method of forming a container, filling the container with a product, and sterilizing the container and the product. The method includes: forming the container from polypropylene or polyethylene by extrusion blow molding, the container including a finish defining an opening, a base including a strap extending perpendicular to a mold parting line, and a body. The body includes: panels spaced apart around the body, each one of the panels extending vertically and tapered inward on opposite sides from both a top and a bottom to a vertical mid-point thereof; and columns extending vertically and spaced apart around the body, each of the columns is between two of the spaced apart panels and further from an axial center of the container than the panels. The method further includes: filling the container with the product at ambient temperature or colder; closing the container with a cap; sterilizing the product by heating the container after filling up to 124°C causing the panels and columns to expand and pressurizing an exterior of the container up to 40 PSI to limit the expansion of the panels and the columns from an as-blown position outward from the axial center of the container; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the panels and the columns to retract inward towards the axial center to the as-blown position or closer to the axial center.

[0021] In further features, the method includes creating a pressure within the container of about 6 PSI.

[0022] In further features, the method includes stabilizing the product includes placing the container with the product therein into a pressure vessel, and introducing steam into the pressure vessel to increase pressure and temperature within the pressure vessel.

[0023] In further features, the method includes forming the container with a first stiffening rib above the panels and the columns and a second stiffening rib below the panels and the columns.

[0024] 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.Attorney Docket No. 8330-000743-WO-POADRAWINGS

[0025] The drawings described herein are for illustrative purposes only of select embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0026] FIG. 1 A is a side view of a polymeric container in accordance with the present disclosure, the polymeric container is in an as-blown, pre-filled configuration;

[0027] FIG. 1 B is another side view of the container of FIG. 1 A rotated from the position of FIG. 1 ;

[0028] FIG. 1 C is a cross-sectional view taken along line 1 C-1 C of FIG. 1 A;

[0029] FIG. 2A is a side view similar to FIG. 1 A of the polymeric container, but with flexible panels thereof expanded in response to the container undergoing a retort sterilization process subsequent to filling and capping of the container;

[0030] FIG. 2B is another side view of the container in the state of FIG. 2A with the container rotated from the position of FIG. 2A;

[0031] FIG. 2C is a cross-sectional view taken along line 2C-2C of FIG. 2A; and

[0032] FIG. 3 is a cross-sectional view of the container taken at the same position of FIG. 2C after the retort sterilization process is complete.

[0033] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0035] The present disclosure is generally directed to polymeric containers. The polymeric containers may be formed by blow molding, such as injection stretch blow molding (ISBM) or extrusion blow molding (EBM), for example. The ISBM process of the present disclosure provides numerous advantages. For example, injection molded preforms can be produced in a separate injection molding machine and later reheated and placed in blow molds of a blow molding machine where they are stretched lengthwise (axial stretch) to about twice their original length. This process is called two-step injection stretch blow molding. Alternately, preforms can be injection molded and placed in blow molds of the same machine where they are stretched lengthwise (axial stretch) to about twice their original length. This process is called one-step injection stretch blow molding.Attorney Docket No. 8330-000743-WO-POACompressed air is then blown into the stretched preforms to expand them (radial stretch) and form the final shape of the container.

[0036] Alternately, the containers can be formed by extrusion blow molding (EBM). EBM is process used to produce hollow plastic parts. With respect to EBM, a cylindrical parison made of melted plastic material is extruded and then inflated inside a container mold to take its final shape. Container extrusion blow molding is commonly used for producing containers for a wide range of products, such as liquid containers, food containers, medical containers, and more. The process offers advantages, such as high production speed, low labor costs, and the ability to produce containers with complex shapes and features.

[0037] As described in detail herein, the present disclosure provides for a container including a plurality of columns that serve as flexible hinges, a plurality of panels are in-between the columns that flex inward and outward, and a barreled shape body contour that helps mitigate temperature and pressure distortion. This prevents ovalization in the retort sterilization cycle due to the combination of a pressure differential between the container and the retort chamber, as well as an increased flexibility of the plastic due to high temperatures (up to 250°F) that soften the material during sterilization.

[0038] With initial reference to FIGS. 1A - 10, an exemplary polymeric container in accordance with the present disclosure is illustrated at reference numeral 10. The container 10 is configured to store any suitable product, such as milk, water, juice, sport drinks, foodstuff, etc. The container 10 may be made of any suitable material, such as any suitable polymeric olefin. Suitable polymeric olefins include, but are not limited to, polypropylene, bio-polypropylene, and polyethylene. Polypropylene (PP) is a thermoplastic polymer that is partially crystalline and non-polar. The properties of PP are similar to polyethylene, but PP is slightly harder and more heat resistant. PP is a white, mechanically rugged material with a high chemical resistance. Bio-PP is the bio-based counterpart of polypropylene.

[0039] PP has a density of between 0.895 and 0.92 g / cm3. Due to the low density of PP, the container 10 made of PP advantageously has a lower density and lower weight as compared to non-PP containers. The Young's modulus of PP is between 1300 and 1800 N / mm2. PP also has good resistance to fatigue. The melting point of PP occurs in a range of 130°C (266 °F) to 166 °C (320 to 331 °F). Polypropylene is resistant to fats and almost all organic solvents, apart from strong oxidants. Non-oxidizing acids and bases can be stored in containers made of PP.Attorney Docket No. 8330-000743-WO-POAMost commercial polypropylene has an intermediate level of crystallinity between that of low-density polyethylene (LDPE) and high-density polyethylene (HDPE). The melt flow rate (MFR) or melt flow index (MFI) is a measure of molecular weight of polypropylene. The measure helps to determine how easily the molten raw material will flow during processing. Polypropylene with higher MFR will fill the plastic mold more easily during the injection or blow-molding production process. As the melt flow increases, however, some physical properties, like impact strength, will decrease. The three general types of polypropylene are homopolymer, random copolymer, and block copolymer.

[0040] High-density polyethylene is a thermoplastic polymer produced from the monomer ethylene. With a high strength-to-density ratio, HDPE is used in the production of plastic bottles. HDPE is commonly recycled, and has the number "2" as its resin identification code. HDPE is known for its high strength-to-density ratio. The density of HDPE can range from 930 to 970kg / m3. Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. The difference in strength exceeds the difference in density, giving HDPE a higher specific strength. It is also harder and more opaque and can withstand somewhat higher temperatures (120°C / 248°F for short periods).

[0041] The container 10 is formed by 1 -step blow molding or extrusion blow molding (EBM). EBM includes melting thermoplastic and a preform or parison, which is a hollow tube. The preform / parison is then captured by two halves of a mold cavity, which is closed around it. The mold halves form the shape of the container 10, including a base 1 10 of the container 10. Air is then blown into the preform / parison, which inflates the preform / parison into the shape of the container 10.

[0042] The container 10 generally includes a finish 12 at a first end 14 of the container 10. The finish 12 defines an opening of the container 10. At an outer surface of the finish 12 are threads 16. The threads 16 are configured to cooperate with corresponding threads of a closure to secure the closure to the finish 12 and close the container 10.

[0043] Below the finish 12 is a neck 30. Extending from the neck 30 is a shoulder 32. The shoulder 32 extends to a body 60 of the container 10. Between the shoulder 32 and the body 60 is a horizontal rib 40. The body 60 may include any suitable number of additional ribs. For example, the body 60 may include a first rib 50 and a second rib 52.Attorney Docket No. 8330-000743-WO-POAThe first rib 50 and the second rib 52 extend entirely around the body 60. The first rib 50 and the second rib 52 are stiffening ribs that provide resistance to ovalization, and also direct internal pressure to panels 70 and columns 90 of the body 60.

[0044] The panels 70 and the columns 90 extend vertically in a direction parallel to, or generally parallel to, a longitudinal axis Y of the container 10 extending through an axial center of the container. The panels 70 and the columns 90 extend vertically between the first rib 50 and the second rib 52. The panels 70 and the columns 90 are spaced apart at regular intervals around an entirety of the body 60 in an alternating arrangement. Thus, each one of the panels 70 is between two of the columns 90. And, each one of the columns 90 is between two of the panels 70. The body 60 may have any suitable sidewall thickness, such as 0.330mm or less. The panels 70 and the columns 90 are described further herein.

[0045] The container 10 further includes the base 110 at a second end 1 12 of the container 10, which is opposite to the first end 14. The base 1 10 may be any suitable base, such as any suitable rigid base. A longitudinal axis “Y” of the container 10 extends through a radial center of the base 1 10, a radial center of the finish 12, and a radial center of the body 60.

[0046] The panels 70 and the columns 90 will now be described in additional detail. Each one of the panels 70 span between the first rib 50, which is an upper rib, and the second rib 52, which is a lower rib. Each one of the panels 70 is curved vertically such that at a vertical midpoint 78 of each panel 70 the panel 70 is closest to the longitudinal axis Y. When viewed from an exterior of the container 10, the panels 70 are concave. Each one of the panels 70 extends vertically and is tapered inward on opposite sides 72A, 72B from both a top 74 and a bottom 76 to the vertical midpoint 78 thereof. Each one of the panels 70 generally has an hour-glass shape.

[0047] The columns 90 also span between the first rib 50 (upper rib) and the second rib 52 (lower rib). The columns 90 are generally straight as viewed from a side of the container 10. The columns 90 generally have opposing concave borders 92A and 92B when viewed from the exterior of the container 10. The columns 90 are outboard from the panels 70 relative to the longitudinal axis Y of the container 10. The intersection of the panels 70, which are curved, and the columns 90, which are straight vertically, defines the panels 70 to have an hour-glass shape when viewed a side of the container 10.Attorney Docket No. 8330-000743-WO-POA

[0048] The container 10 includes a plurality of the panels 70 and the columns 90. The container 101 may include any suitable number of the panels 70 and the columns 90, such as five panels 70 and five columns 90. The panels 70 and the columns 90 alternate around the perimeter of the container body 60. There are an equal number of panels 70 and columns 90 in the example illustrated.

[0049] FIG 1 C illustrates a reference circle R, which represents an outermost diameter of the container 10 in the as-blown, pre-filled configuration. In the example illustrated, each one of the columns 90 touches, or nearly touches, the reference circle R at the vertical midpoint of each column 90. Each one of the panels 70 is inward of the reference circle R at the midpoint 78 of each of the panels 70. Thus, a distance D1 between the panels 70 and the longitudinal axis Y is less than a distance D2 between the columns 90 and the longitudinal axis Y.

[0050] FIGS. 2A - 2C illustrate the container 10 with the body 60 generally expanded in response to the container 10 undergoing a retort sterilization process subsequent to filling and capping the container 10. After the container 10 is formed by 1 - step blow molding or EBM, the container 10 is rinsed with an ionized air jet or water spray. The container 10 is then filled with any suitable product at ambient temperature, or colder. The opening of the container 10 is subsequently capped with any suitable closure 80. The closure 80 is applied with any suitable steam flush or nitrogen. The capped container 10 is then placed in a holding basket. The holding basket full of multiple ones of the container 10 is placed into a large pressure vessel, which is then sealed.

[0051] Steam is introduced into the pressure vessel, which increases the an internal temperature of the pressure vessel up to 124°C, and increases the internal pressure of the vessel up to approximately 40 PSI at sea level. A pressure within the container 10 is created of -6PSI to 6PSI. During this retort sterilization cook cycle, the basket full of containers 10 rotates while being held at a predetermined temperature and pressure. Pressure is released during a ramp down cycle as the basket rotates and the temperature and pressure decreases. This entire process lasts for about 30-90 minutes.

[0052] FIGS. 2A, 2B, 2C illustrate the container 10 during the retort sterilization cook cycle. During the cook cycle, pressure is increased within the container 10, which causes the panels 70 and columns 90 to expand outward. With particular reference to FIG. 2C, this outward expansion of the panels 70 results in the panels 70 moving outward near to (or to) the reference circle R. The ribs 50, 52 and a base strap 120 limit pressureAttorney Docket No. 8330-000743-WO-POA expansion at the ribs 50, 52 and the base strap 120. As a result, the pressure expansion is directed to the panels 70, which are configured to flex.

[0053] During the ramp down cycle, pressure within the container 10 decreases, which results in panels 70 retracting to their as-blown positions of FIG. 1 C, or retracting further inward towards the longitudinal axis Y, as illustrated in FIG. 3. In the example of FIG. 3, after pressure within the container 10 is reduced, the panels 70 retract to slightly within the reference circle R.

[0054] The container 10 including the panels 70 and the columns 90 is advantageously configured to withstand a fill pressure of greater than 35 psi before any localized deformation occurs. The container 10 is also configured to withstand a positive volume displacement of greater than 4% before any localized deformation occurs. The container 10 is further configured to withstand a vacuum of greater than 16 in. Hg before any localized deformation failure. And, the container 10 is configured to withstand negative volume displacement of greater than 3% before any localized deformation failure.

[0055] 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 disclosure. 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 disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0056] 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. In some example embodiments, well- known processes, well-known device structures, and well-known technologies are not described in detail.

[0057] 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 singularAttorney Docket No. 8330-000743-WO-POA 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.

[0058] 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.

[0059] 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.

[0060] 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. ForAttorney Docket No. 8330-000743-WO-POA 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.

Claims

Attorney Docket No. 8330-000743-WO-POACLAIMSWhat is claimed is:

1. A method of forming, filling, and sterilizing a container, the method comprising: forming the container by blow molding, the container including a finish defining an opening, a base, and a body including: panels spaced apart around the body, each one of the panels extending vertically and tapered inward on opposite sides from both a top and a bottom to a vertical mid-point thereof; and columns extending vertically and spaced apart around the body, each of the columns is between two of the spaced apart panels and further from an axial center of the container than the panels; filling the container with a product at ambient temperature or colder; closing the container with a cap; sterilizing the product by pressurizing an exterior of the container and heating both the container and the product to cause the panels and the columns to expand from an as-blown position outward from the axial center of the container; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the panels and the columns to retract inward towards the axial center to the as-blown position or closer to the axial center.

2. The method of claim 1 , wherein sterilizing the product includes placing the container with the product therein into a pressure vessel, and introducing steam into the pressure vessel to increase pressure and temperature within the pressure vessel.

3. The method of claim 2, further comprising increasing the temperature within the pressure vessel to up to 124°C.

4. The method of claim 2, further comprising increasing pressure within the pressure vessel up to 40 PSI at sea level.

5. The method of claim 2, further comprising creating a pressure within the container of -6 PSI to 6 PSI.Attorney Docket No. 8330-000743-WO-POA6. The method of claim 1 , further comprising forming the container from polypropylene.

7. The method of claim 1 , further comprising forming the container with a first stiffening rib above the columns and a second stiffening rib below the columns.

8. The method of claim 1 , wherein the panels are horizontally convex and vertically concave relative to an exterior of the container.

9. The method of claim 1 , wherein the columns have opposing concave borders, and the columns are further from the axial center than the panels.

10. The method of claim 1 , wherein cooperation between curved portions of the panels and straight portions of the columns provides the panels with an hour-glass shape at an exterior of the container.1 1. The method of claim 1 , wherein the container includes only five of the panels and only 5 of the columns.

12. The method of claim 1 , wherein the container is made of one of polypropylene and polyethylene.

13. The method of claim 1 , wherein the container is formed by a one-step or extrusion blow molding process.

14. A method of forming a container, filling the container with a product, and sterilizing the container and the product, the method comprising: forming the container from polypropylene or polyethylene by extrusion blow molding, the container including a finish defining an opening, a base including a strap extending perpendicular to a mold parting line, and a body including: panels spaced apart around the body, each one of the panels extending vertically and tapered inward on opposite sides from both a top and a bottom to a vertical mid-point thereof;Attorney Docket No. 8330-000743-WO-POA columns extending vertically and spaced apart around the body, each of the columns is between two of the spaced apart panels and further from an axial center of the container than the panels; filling the container with the product at ambient temperature or colder; closing the container with a cap; sterilizing the product by heating the container after filling up to 124°C causing the panels and columns to expand and pressurizing an exterior of the container up to 40 PSI to limit the expansion of the panels and the columns from an as-blown position outward from the axial center of the container; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the panels and the columns to retract inward towards the axial center to the as-blown position or closer to the axial center.

15. The method of claim 14, further comprising creating a pressure within the container of about 6 PSI.

16. The method of claim 14, wherein stabilizing the product includes placing the container with the product therein into a pressure vessel, and introducing steam into the pressure vessel to increase pressure and temperature within the pressure vessel.

17. The method of claim 14, further comprising forming the container with a first stiffening rib above the panels and the columns and a second stiffening rib below the panels and the columns.

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