WO2024186514A1

WO2024186514A1 - Polymeric container including a body with a plurality of undulating panels

Info

Publication number: WO2024186514A1
Application number: PCT/US2024/017434
Authority: WO
Inventors: John Siciliano; Kevin Dwight GAYDOSH
Original assignee: Amcor Rigid Packaging Usa, Llc
Priority date: 2023-03-03
Filing date: 2024-02-27
Publication date: 2024-09-12

Abstract

A method of forming, filling, and sterilizing a container. 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 and heating both the container and the product to cause the plurality of inner panels and the plurality of outer panels to expand from an as-blown position outward from the longitudinal axis; and depressurizing the container and returning the container to the ambient temperature or colder to cause both the plurality of outer panels and the plurality of inner panels to retract inward towards the longitudinal axis to the as-blown position or closer to the longitudinal axis.

Description

POLYMERIC CONTAINER INCLUDING

A BODY WITH A PLURALITY OF UNDULATING PANELS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a PCT International Application and claims the benefit of U.S. Provisional Application No. 63/449,794, filed on March 3, 2023. The entire disclosure of the above application is incorporated herein by reference.

FIELD

[0001] The present disclosure relates to a method of forming a polymeric container including a body with a plurality of undulating panels.

BACKGROUND

[0002] This section provides background information related to the present disclosure, which is not necessarily prior art.

[0003] Polymeric containers may be formed by extrusion blow molding (EBM). EBM is a manufacturing technique used to produce hollow plastic parts. With respect to container extrusion blow molding, 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.

[0004] While existing EBM 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

[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0006] The present disclosure includes, in various features, a method of forming, filling, and sterilizing a container. The method includes: forming the container by extrusion blow molding, the container including a finish defining an opening, a base, and a body including an undulating ring extending entirely around the body, the undulating ring including a plurality of inner panels and a plurality of outer panels in an alternating arrangement such that each one of the plurality of inner panels is between two of the plurality of outer panels and each one of the plurality of outer panels is between two of the plurality of inner panels, each one of the plurality of inner panels is closer to a longitudinal axis of the container than each one of the plurality of outer 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 plurality of inner panels and the plurality of outer panels to expand from an as-blown position outward from the longitudinal axis; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the plurality of outer panels and the plurality of inner panels to retract inward towards the longitudinal axis to the as-blown position or closer to the longitudinal axis.

[0007] In further features, the present disclosure includes: a method of forming, filling, and sterilizing a container. The method includes: forming the container from polypropylene 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 an undulating ring extending entirely around the body, the undulating ring including a plurality of inner panels and a plurality of outer panels in an alternating arrangement such that each one of the plurality of inner panels is between two of the plurality of outer panels and each one of the plurality of outer panels is between two of the plurality of inner panels, each one of the plurality of inner panels is closer to a longitudinal axis of the container than each one of the plurality of outer panels; filling the container with a 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 and pressurizing an exterior of the container up to 40 PSI to cause the plurality of inner panels and the plurality of outer panels to expand from an as-blown position outward from the longitudinal axis; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the plurality of outer panels and the plurality of inner panels to retract inwards towards the longitudinal axis to the as- blown position or closer to the longitudinal axis.

[0008] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

[0009] 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.

[0010] FIG. 1A 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;

[0011] FIG. 1 B is another side view of the container of FIG. 1 A rotated from the position of FIG. 1 ;

[0012] FIG. 1 C is a cross-sectional view taken along line 1 C-1 C of FIG. 1 A;

[0013] FIG. 1 D is a plan view of a base of the container of FIG. 1 A;

[0014] 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;

[0015] 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;

[0016] FIG. 2C is a cross-sectional view taken along line 20-20 of FIG. 2A; and

[0017] 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.

[0018] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0019] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0020] With initial reference to FIGS. 1 A - 1 D, 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 and bio-polypropylene. 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 biobased counterpart of polypropylene.

[0021] 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. Most 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.

[0022] The container 10 is formed by extrusion blow molding (EBM). EBM includes melting PP and extruding the PP into a parison, which is a hollow tube. The 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 110 of the container 10. There is no additional moving component to form the base. Air is then blown into the parison, which inflates the parison into the shape of the container 10. EBM includes no axial stretching of the PP material as the PP is blown into the final shape of the container 10.

[0023] 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.

[0024] 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. The 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 an undulating ring 70 of the body 60.

[0025] The undulating ring 70 is between the first rib 50 and the second rib 52. Although only one undulating ring 70 is illustrated, any suitable number of undulating panels 70 may be included. The undulating ring 70 extends around an entirety of the body 60. The undulating ring 70 may have any suitable sidewall thickness, such as 0.330mm or less. The undulating ring 70 is generally a flexible ring. The undulating ring 70 will be described further herein.

[0026] The container 10 further includes the base 110 at a second end 112 of the container 10, which is opposite to the first end 14. The base 110 may be any suitable base, such as any suitable vacuum absorbing base. A longitudinal axis “Y” of the container 10 extends through a radial center of the base 110, a radial center of the finish 12, and a radial center of the body 60.

[0027] With particular reference to FIG. 1 D, the base 110 includes a base strap 120. The base strap 120 extends across the radial center of the base 110 and through the longitudinal axis Y. The base strap 120 is oriented 90° relative to a mold parting line 122. At opposite ends of the mold parting line 122 are indentations 130 at a standing ring of the base 110. As a result, when the mold opens the container 10 may be removed from the mold without sticking to the mold, which may otherwise occur as a result of negative draft. The base strap 120 provides additional strength and stiffness to the base 110, which prevents the base 110 from deforming due to changes in pressure. The base strap 120 directs the pressure response to the undulating ring 70. The base strap 120 is tapered such that the base strap 120 is most narrow at the center of the base 110 through which the longitudinal axis Y extends. The base strap 120 is most wide at the outer ends 126 thereof at a heel 124 of the container 10. Thus, the base strap 120 flares outward at the heel 124, as illustrated in FIGS. 1 A and 1 D, for example. The shape of the base strap 120 allows the container 10 to release from the EBM mold without catching on the base strap 120.

[0028] The undulating ring 70 will now be described in additional detail. The undulating ring 70 extends entirely around the body 60 of the container 10. The undulating ring 70 includes a plurality of inner panels 72 and a plurality of outer panels 74. The inner panels 72 and the outer panels 74 are arranged in an alternating arrangement such that each inner panel 72 is between two outer panels 74, and each outer panel 74 is between two inner panels 72.

[0029] The inner panels 72 each curve inward towards the longitudinal axis Y, and are concave at an outer surface of the container 10. The outer panels 74 are outboard of the inner panels 72 relative to the longitudinal axis Y. The outer panels 74 may also be concave an the outer surface of the container 10, and thus the outer panels 74 may have a shape similar to the inner panels 72. Alternatively, the outer panels 74 may be vertically extending columns that extend parallel to, or relatively parallel to, the longitudinal axis Y prior to the container 10 being filled and capped.

[0030] The undulating ring 70 may have any suitable number of inner panels 72 and outer panels 74. In the example illustrated, the container 10 has six inner panels 72 and six outer panels 74. However, the container 10 may include 4-8 of each one of the inner panels 72 and the outer panels 74, with there being an equal number of inner panels 72 and outer panels 74.

[0031] FIG 1 C illustrates a reference circle R, which represents an outermost diameter of the container 10. In the example illustrated, each one of the outer panels 74 touches, or nearly touches, the reference circle R. Each one of the inner panels 72 is slightly inward of the reference circle R. Thus, a distance D1 between the inner panels 72 and the longitudinal axis Y is less than a distance D2 between the outer panel 74 and the longitudinal axis Y. The undulating ring 70 has a first diameter between opposing outer panels 74, which is larger than a second diameter between opposing inner panels 72. [0032] With reference to FIGS. 2A - 2C, after the container 10 is formed by 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, and then the opening of the container 10 is 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.

[0033] 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 6PSL 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.

[0034] 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 undulating ring 70 to expand outward. With particular reference to FIG. 2C, expansion outward of the undulating ring 70 results in the inner panel 72 moving outward to (or near to) the reference circle R. Expansion outward of the undulating ring 70 results in the outer panel 74 moving outward beyond the reference circle R. The ribs 50, 52 and the base strap 120 limit pressure expansion at the ribs 50, 52 and the base strap 120. As a result, the pressure expansion is directed to the undulating ring 70, which is configured to flex.

[0035] During the ramp down cycle, pressure within the container 10 decreases, which results in the inner panel 72 and the outer panel 74 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 outer panel 74 retracts to slightly within the reference circle R and the inner panel 72 retracts inward of the outer panel 74.

[0036] The container 10 including the undulating ring 70 and the base strap 120 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.

[0037] 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.

[0038] 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.

[0039] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0040] 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.

[0041] 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.

[0042] Spatially relative terms, such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Claims

CLAIMS What is claimed is:

1. A method of forming, filling, and sterilizing a container, the method comprising: forming the container by extrusion blow molding, the container including a finish defining an opening, a base, and a body including an undulating ring extending entirely around the body, the undulating ring including a plurality of inner panels and a plurality of outer panels in an alternating arrangement such that each one of the plurality of inner panels is between two of the plurality of outer panels and each one of the plurality of outer panels is between two of the plurality of inner panels, each one of the plurality of inner panels is closer to a longitudinal axis of the container than each one of the plurality of outer 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 plurality of inner panels and the plurality of outer panels to expand from an as-blown position outward from the longitudinal axis; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the plurality of outer panels and the plurality of inner panels to retract inward towards the longitudinal axis to the as-blown position or closer to the longitudinal axis.

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.

6. 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 undulating ring and a second stiffening rib below the undulating ring.

8. The method of claim 1 , further comprising forming the base of the container with a base strap extending 90° relative to a mold parting line.

9. The method of claim 8, wherein the base strap is most narrow at a center of the base, and the base strap is widest at a heel of the container.

10. The method of claim 9, wherein ends of the base strap extend upward from the base along the heel of the container.

11. A method of forming, filling, and sterilizing a container, the method comprising: forming the container from polypropylene 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 an undulating ring extending entirely around the body, the undulating ring including a plurality of inner panels and a plurality of outer panels in an alternating arrangement such that each one of the plurality of inner panels is between two of the plurality of outer panels and each one of the plurality of outer panels is between two of the plurality of inner panels, each one of the plurality of inner panels is closer to a longitudinal axis of the container than each one of the plurality of outer panels; filling the container with a 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 and pressurizing an exterior of the container up to 40 PSI to cause the plurality of inner panels and the plurality of outer panels to expand from an as-blown position outward from the longitudinal axis; and depressurizing the exterior of the container and returning the container to the ambient temperature or colder to cause both the plurality of outer panels and the plurality of inner panels to retract inwards towards the longitudinal axis to the as-blown position or closer to the longitudinal axis.

12. The method of claim 11 , further comprising creating a pressure within the container of -6 PSI to 6 PSI.

13. The method of claim 11 , 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.

14. The method of claim 11 , further comprising forming the container with a first stiffening rib above the undulating ring and a second stiffening rib below the undulating ring.

15. The method of claim 11 , wherein the strap is most narrow at a center of the base, and the strap is widest at a heel of the container.

16. The method of claim 15, wherein ends of the strap extend upward from the base along the heel of the container.