WO2025226259A1

WO2025226259A1 - Preform and container including base rings

Info

Publication number: WO2025226259A1
Application number: PCT/US2024/025768
Authority: WO
Inventors: Michael T. Lane; James Stelzer
Original assignee: Amcor Rigid Packaging USA LLC
Current assignee: Amcor Rigid Packaging USA LLC
Priority date: 2024-04-23
Filing date: 2024-04-23
Publication date: 2025-10-30
Anticipated expiration: 2026-10-23

Abstract

A preform configured to be molded into a container including: a finish defining an opening; a tip defined by an inner surface and an outer surface at an end of the preform opposite to the finish, the tip configured to form a base of the container; a plurality of rings defined by at least one of the inner surface of the tip and the outer surface of the tip, the inner surface of the tip is opposite to the outer surface of the tip, the plurality of rings including a ridge and a recess, the plurality of rings configured to form base rings at the base of the container; and a preform body between the tip and the finish, the preform body configured to form a body of the container.

Description

PREFORM AND CONTAINER INCLUDING BASE RINGS

FIELD

[0001] The present disclosure relates to a preform and container including base rings.

BACKGROUND

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

[0003] As a result of environmental and other concerns, plastic containers, more specifically polyester and even more specifically polyethylene terephthalate (PET) containers, are now being used more than ever to package numerous commodities previously supplied in glass containers. Manufacturers and fillers, as well as consumers, have recognized that PET containers are lightweight, inexpensive, recyclable and manufacturable in large quantities.

[0004] Blow-molded plastic containers have become commonplace in packaging numerous commodities. PET is a crystallizable polymer, meaning that it is available in an amorphous form or a semi-crystalline form. The ability of a PET container to maintain its material integrity relates to the percentage of the PET container in crystalline form, also known as the “crystallinity” of the PET container. The following equation defines the percentage of crystallinity as a volume fraction: 100 where p is the density of the PET material; pa is the density of pure amorphous PET material (1 .333 g/cc); and pc is the density of pure crystalline material (1 .455 g/cc).

[0005] Container manufacturers use mechanical processing and thermal processing to increase the PET polymer crystallinity of a container. Mechanical processing involves orienting the amorphous material to achieve strain hardening. This processing commonly involves stretching an injection molded PET preform along a longitudinal axis and expanding the PET preform along a transverse or radial axis to form a PET container. The combination promotes what manufacturers define as biaxial orientation of the molecular structure in the container. Manufacturers of PET containers currently use mechanical processing to produce PET containers having approximately 20% crystallinity in the container’s sidewall.

[0006] Thermal processing involves heating the material (either amorphous or semi-crystalline) to promote crystal growth. On amorphous material, thermal processing of PET material results in a spherulitic morphology that interferes with the transmission of light. In other words, the resulting crystalline material is opaque, and thus, generally undesirable. Used after mechanical processing, however, thermal processing results in higher crystallinity and excellent clarity for those portions of the container having biaxial molecular orientation. The thermal processing of an oriented PET container, which is known as heat setting, typically includes blow molding a PET preform against a mold heated to a temperature of approximately 250°F - 350°F (approximately 121 °C - 177°C), and holding the blown container against the heated mold for approximately two (2) to five (5) seconds. Manufacturers of PET juice bottles, which must be hot-filled at approximately 185°F (85°C), currently use heat setting to produce PET bottles having an overall crystallinity in the range of approximately 25%-35%.

[0007] Hot-fill is a packaging and processing technique in which heat is used to sterilize food and beverage products during the filling process. The hot-fill process includes heating the product to elevated temperatures to kill bacteria and microorganisms. The product is then filled into containers, and sealed immediately with a closure. The sealed container is then cooled to ambient temperature. The hot-fill process creates a temporary increase in pressure within the container after filling and sealing. During cooling, the pressure is reduced due to a reduction in volume as the temperature decreases and the product contracts, resulting in a residual vacuum condition within the filled and sealed container.

[0008] As an alternative to hot-filling containers that are heat-set as described above, aseptic processing is also a common sterilization process. In aseptic processing, the product is sterilized outside the container and then filled into a previously sterilized container, which is then sealed with a previously sterilized closure in a sterile environment. Ultra-high temperature (UHT) sterilization is used to sterilize the product before it is filled into a container at high temperatures usually above 135°C for 1-2 seconds for example. Aseptic containers and closures are sterilized to kill microorganisms present due to manufacturing and transporting prior to filling using heat, hot water, hydrogen peroxide or peracetic acid), and radiation. Sterilized containers are filled with sterilized product at lower temperatures that hot-fill such as ambient therefore there is no need to use previously heat-set containers. The lower filling temperature also creates less residual vacuum within the filled and sealed container. However, internal container vacuum is still a concern due to vapor loss over time.

[0009] Another sterilization process is retort, where non-sterile products are filled into containers at room temperature into a non-sterile package, and hermetically sealed. Once the product has been filled, the package is loaded into a retort pressure chamber. While in the chamber, the package’s contents are sterilized with pressurized steam temperatures greater than 100°C (212°F) for a period of time to sterilize the package and the contents simultaneously.

SUMMARY

[0010] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0011] A preform configured to be molded into a container including: a finish defining an opening; a tip defined by an inner surface and an outer surface at an end of the preform opposite to the finish, the tip configured to form a base of the container; a plurality of rings defined by at least one of the inner surface of the tip and the outer surface of the tip, the inner surface of the tip is opposite to the outer surface of the tip, the plurality of rings including a ridge and a recess, the plurality of rings configured to form base rings at the base of the container; and a preform body between the tip and the finish, the preform body configured to form a body of the container.

[0012] The present disclosure further includes a preform configured to be molded into a container. The preform includes: a finish defining an opening; threads on an outer surface of the finish; a preform body configured to form a body of the container; a tip defined by an inner radius and an outer radius at an end of the preform opposite to the finish, the tip configured to form a base of the container, a longitudinal axis of the preform extends through a center of the tip; and a plurality of ridges defined by at least one of an inner surface of the tip and an outer surface of the tip, the inner surface of the tip is opposite to the outer surface of the tip, the plurality of ridges encircling the longitudinal axis and configured to form base rings of the container.

[0013] The present disclosure also provides for a container formed from a preform, the container including: a finish defining an opening; threads at an outer surface of the finish; a body defining a sidewall of the container; and a base configured to support the container upright, the base including a plurality of rings defined by ridges and recesses at an outer surface or inner surface of the base extending around an axial center of the base.

[0014] 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

[0015] 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.

[0016] FIG. 1 is a side view of a preform in accordance with the present disclosure;

[0017] FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1 ;

[0018] FIG. 3 is a cross-sectional view of a tip area of the preform;

[0019] FIG. 4 is a cross-sectional view of one-half of the preform of FIG. 1 , and one-half of a container that the preform is configured to form;

[0020] FIG. 5 is a side view of the preform including rings at an inner surface;

[0021] FIG. 6 is a plan view of a bottom of the preform including alternately shaped rings in accordance with the present disclosure;

[0022] FIG. 7A is a plan view of a bottom of the preform including additional alternately shaped rings in accordance with the present disclosure; and

[0023] FIG. 7B is a cross-sectional view of the preform of FIG. 7A.

[0024] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0025] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0026] The present disclosure is directed to a preform 10 (FIGS. 1 -4) configured to form a container, such as the container 1 10 of FIG. 4. The preform 10 is formed of any suitable polymeric material by injection molding. The preform 10 may be formed of polyethylene terephthalate (PET or PETE), recycled PET (rPET) (such as post-consumer recycled (PCR) resin or postindustrial regrind (PIR)), or high-density polyethylene (HDPE), for example and as explained further herein. [0027] The preform 10 includes a preform tip 60 with a plurality of rings 70. With particular reference to FIG. 3, the rings 70 are the results of a plurality of ridges 80 defined by recesses 82 on opposite sides of each ridge. The preform tip 60 with rings 70 provide a breakthrough in injection and blow molding manufacturing. For example, the preform tip 60, and specifically the rings 70, advantageously provide a five to ten percent increase in surface area (or an increase of up to 3%, or an increase of up to 10%) of the preform tip 60 and a base 140 of the container 110 formed by the tip 60, which revolutionizes the production process. The increase in surface area is compared to a smooth surface area defined by the recesses 82 of the plurality of rings 70. Due to the increased local surface area, preform gate conductive cooling (W/mK) during injection molding and preform gate radiant reheating (W/mK) during container blow molding are significantly improved. This results in enhanced process capability, allowing for increased utilization of rPET material, such as PGR and PIR material.

[0028] Containers including the base 140 molded from the preform tip 60 exhibit improved material tensile orientation (lb/in²) and material modulus (N/m²) in the base 140. The heightened structural integrity enhances the container base 140, facilitating a smoother demolding process and enabling container light weighting. Additionally, the improved material modulus effectively avoids brittleness caused by PCR material contaminants or suboptimal moisture levels during preform injection molding.

[0029] The rings 70 of the preform 10 form visible container base rings 170 at the base 140, which lead to higher quality and sustainability through lighter weight packaging. Up to 10% of the weight of the container base 140 can be shifted to other areas of the container 110, or the total weight of the container 110 can be reduced by up to 10%. The rings 70 of the preform tip 60 not only elevate manufacturing efficiency, but also foster a greener approach to packaging production. By embracing this advancement, manufacturers can create high-performance containers, optimized for strength and environmental responsibility.

[0030] Further to the discussion above regarding materials, the preform 10 may be injection molded from PET, or any other suitable polymeric material, such as HDPE or polypropylene. The preform 10 may also be formed of up to 100% PET PCR material. DAK Americas HS Ti818 is an example of a suitable PET resin. PET is a clear, strong, and lightweight plastic that is widely used for packaging foods and beverages, convenience-sized soft drinks, juices and water. It is also popular for packaging salad dressings, peanut butter, cooking oils, mouthwash, shampoo, soaps, cleaners, and the like. The basic building blocks of PET are ethylene glycol and terephthalic acid, which are combined to form a polymer chain. The resulting spaghettilike strands of PET are extruded, quickly cooled, and cut into small pellets. The resin pellets are then heated to a molten liquid that can be easily extruded or molded into items of practically any shape. PET is completely recyclable, and is the most recycled plastic in the U.S and worldwide. PET can be commercially recycled by thorough washing and re-melting, or by chemically breaking it down to its component materials to make new PET resin. Almost every municipal recycling program in North America and Europe accepts PET containers. Products commonly made from recycled PET include new PET bottles and jars. Recycled PET is commonly referred to as rPET and PCR.

[0031] Post consumer recycled (PCR) resin is the recycled product of waste created by consumers. Post Industrial Regrind (PIR) is any closed-loop/recaptured scrap resin directly resulting from the manufacturing process such as the scrap created by the manufacturing process of bottles and closures that is solely recaptured and reworked within the manufacturing plant such as hot-runners, flash, moils, and tails from the molding or extruding process that has gone through at least one molding or extrusion process and is subsequently grounded and reintroduced back into the manufacturing process. Since PCR/PIR regrind material has gone through an initial heat and molding process it cannot be considered “virgin” material. The physical, chemical and flow properties can differ slightly from virgin material, therefore PCR and PIR is not generally used exclusively to make new bottles or parts, but it is blended with virgin PET. Before PCR and PIR plastic is turned into resin, the materials are sent through a proprietary process and cleaning to produce plastic resin pellets. Verdeco food-grade rPET is an example of a suitable resin.

[0032] 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).

[0033] Polypropylene (PP) is a thermoplastic within the polyolefin group and has an increased molecular crystallinity, flexibility, physical toughness, chemical tolerance, and resistance to high and low temperatures. Polypropylene is a large molecular compound constructed from repeating units of individual propylene monomers linked together by chemical reaction. Polypropylene belongs to the olefin group of simple double-bonded molecules that have their bonds broken and then reconnected to formulate the polymer chain known.

[0034] With particular reference to FIGS. 1 -3, the preform 10 will now be described in additional detail. The preform 10 includes a finish 20, which is configured to form a finish of the container 1 10. The finish 20 defines an opening 22. At an outer surface of the finish 20 are threads 24, which are configured to cooperate with any suitable closure for closing the opening 22. The threads 24 are illustrated as external threads, but the threads 24 may alternatively be internal threads.

[0035] Below the finish 20 is a flange 30. The flange 30 is configured to support the preform 10 in any suitable molding equipment. Below the flange 30 is a preform body 40, which is configured to form a body 130 of the container 110. At a distal end 50 of the preform 10 is the preform tip 60. The preform body 40 is between the preform tip 60 and the flange 30.

[0036] The preform tip 60 is configured to form a base 140 of the container 110. The preform tip 60 tapers inward towards a longitudinal axis A of the preform 10 in a direction extending away from the preform body 40 to the distal end 50, which is generally a pointed end. The longitudinal axis A extends through an axial center of the opening 22, through a center of the finish 20, a center of the preform tip 60, and a center of the distal end 50.

[0037] The preform tip 60 includes an outer surface 62 and an inner surface 64, which is opposite to the outer surface 62. At the outer surface 62 (FIGS. 1 -4) and/or the inner surface 64 (FIG. 5) are a plurality of circumferential rings 70, which encircle the longitudinal axis A. The longitudinal axis A is at a center of each one of the rings 70. The rings 70 are generally configured as stepped surfaces that can be circular and have polygonal or rounded portions or segments, of the preform tip 60. The rings 70 are configured to form base rings 170 of the base 140. The rings 70 progressively decrease in circumference in a direction extending from the preform body 40 to the distal end 50. With particular reference to FIGS. 2 and 3, the rings 70 include a plurality of ridges 80 of the outer surface 62. Each ridge 80 defines a recess 82 on opposite sides of the ridge 80. The recess 82 define an imaginary line or radius defining a smooth surface of the preform tip 60. The ridges 80 are present at the base ring 170 of the base 140. The outer surface 62 and/or the inner surface 64 of the preform tip 60 including the rings 70 has a surface area of at least 14.0cm², such as a surface area of 14.3cm². The inner surface 64 opposite to the outer surface 62 can be smooth, or generally smooth; the outer surface 62 opposite to the inner surface 64 can be smooth, or generally smooth; or both the outer surface 62 and the inner surface 64 can include the plurality of rings 70.

[0038] With reference to FIG. 6, each ring 70 may include an outer surface profile that is wave-like or curved around the circumference of each ring 70. For example, each ring 70 may define a plurality of curved ring ridges 90 and ring recesses 92. With reference to FIGS. 7A and 7B, each ring 70 may include an outer surface profile that is more angular or polygonal around the circumference of each ring 70. For example, each ring 70 may define a plurality of pointed ring ridges 94 and pointed ring recesses 96, and may include linear or generally linear surfaces connecting the pointed ring ridges 94 and the pointed ring recesses 96. The ring recesses 92 and the pointed ring recesses 96 may each define an imaginary line or radius defining a smooth surface of the preform tip 60.

[0039] The preform 10 is configured to be molded into the container 1 10 in any suitable manner. For example, the preform 10 is configured to be molded into the container 110 by injection stretch blow molding, injection blow molding, one-step blow molding, or two-step blow molding. With particular reference to FIG. 4, the container 110 includes a shoulder 120, which is formed from an area of the preform 10 just below the flange 30. The shoulder 120 transitions to the container body 130. The container body 130 may include any suitable number of ribs 132. At a distal end of the body 130 is the base 140, which is formed from the preform tip 60.

[0040] The base 140 includes a standing surface 142, which is a standing ring outboard of a center portion 160, which may be a flexible portion, such as a push-up portion, a diaphragm, or a cone that is configured to be movable in response to vacuum and pressure changes within the container; or movable by an externally applied mechanical force. The longitudinal axis A extends through an axial center of the center portion 160. The standing surface 142 and the center portion 160 may be configured in any suitable manner. In one example, between the standing surface 142 and the center portion 160 is a hinge 150, which extends around the longitudinal axis A. The hinge 150 includes a curved surface 152, about which the hinge 150 is configured to flex. Extending from the curved surface 152 towards the longitudinal axis A is an inner ring 154. Extending from the curved surface 152 towards the standing surface 142 is an outer ring 156. The hinge 150 and the adjacent portions of both the inner ring 154 and the outer ring 156 are formed from the preform tip 60, which is pressed against a corresponding base mold during molding of the container 1 10. The rings 70 are present on outsides of the curved surface 152, the inner ring 154, and the outer ring 156 in the form of base rings 170.

[0041] The container 1 10 may be formed from the preform 10 by two-step stretch blow molding or any other suitable process, such as injection stretch blow molding (ISBM). Two-step stretch blow molding includes using the pre-made injection molded preform 10 optimized for the final blow molded container 1 10. The preform 10 can be injection molded or compression molded. The molded preform 10 is reheated and placed in a blow mold, where it is stretched lengthwise (axial stretch) to about twice its original length. Compressed air is blown into the stretched preform 10 to expand it into the blow mold (radial stretch) forming the final shape of the container 1 10.

[0042] The present disclosure provides numerous advantages. In particular, the increase in the surface area of the preform tip 60 provided by the rings 70 (including the ridges 80 and the recesses 82) results in the following advantages, for example: decrease in mold cooling time during injection and blow molding; improved heating of the preform tip 60 during blow molding; improved demolding from the blow mold due to increased oil applied to the increased surface area of the preform tip 60; improved control over material placement in the container 1 10 due to reduced stretching force resulting in less material in the base 140 because material can be shifted to other areas of the container 1 10; lower material thickness in the base 140 to increase flexibility; container weight can be reduced due to increased control over material placement and less material weight in the base 140; reduced crystallinity in the base 140; and higher amounts of PCR material up to 100%. The ridges 80 and the recesses 82 (and the curved ring ridges 90, ring recesses 92, pointed ring ridges 94, and pointed ring recesses 96) also create variations in material modulus when blow molded into the container base 140. The thicker material at the ridges 80, 90, 94 has a lower modulus relative to the thin material at the recess 82 having a higher modulus. The variation in modulus advantageously increases mechanical strength and crystallinity in the base 140. One skilled in the art will appreciate that the present disclosure provides numerous additional advantages as well.

[0043] 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.

[0044] 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, 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.

[0045] 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. [0046] 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.

[0047] 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.

[0048] 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.

Claims

CLAIMS What is claimed is:

1 . A preform configured to be molded into a container, the preform comprising: a finish defining an opening; threads on an outer surface of the finish; a tip defined by an inner surface and an outer surface at an end of the preform opposite to the finish, a longitudinal axis of the preform extends through a center of the tip and an axial center of the opening, the tip configured to form a base of the container; a plurality of rings defined by at least one of the inner surface of the tip and the outer surface of the tip, the inner surface of the tip is opposite to the outer surface of the tip, the plurality of rings including a ridge and a recess, the plurality of rings configured to form base rings at the base of the container; and a preform body between the tip and the finish, the preform body configured to form a body of the container.

2. The preform of claim 1 , wherein the plurality of rings are circumferential rings extending around the longitudinal axis of the preform, the longitudinal axis extends through a center of each one of the plurality of rings.

3. The preform of claim 2, wherein the plurality of rings include a plurality of curved segments or a plurality of polygonal segments.

4. The preform of claim 2, wherein the plurality of rings include an outer surface profile that is curved or polygonal.

5. The preform of claim 1 , wherein the tip is tapered inward from the preform body to a distal end of the preform.

6. The preform of claim 1 , wherein the plurality of rings are defined by stepped surfaces of the tip.

7. The preform of claim 1 , wherein the preform is made of polyethylene terephthalate.

8. The preform of claim 1 , wherein the plurality of rings are at the outer surface of the tip and the inner surface is smooth.

9. The preform of claim 1 , wherein the plurality of rings are at the inner surface of the tip and the outer surface is smooth.

10. The preform of claim 1 , wherein the plurality of rings are at the inner surface of the tip and the outer surface of the tip.

1 1 . The preform of claim 1 , wherein the plurality of rings progressively decrease in circumference in a direction extending from the preform body to the tip.

12. The preform of claim 1 , wherein the preform is configured to be molded into the container by blow molding.

13. The preform of claim 1 , wherein the preform is formed by injection molding.

14. The preform of claim 1 , wherein the preform is formed by compression blow forming.

15. The preform of claim 1 , wherein the outer surface defining the plurality of rings has a surface area up to 10% greater than a smooth surface area defined by the recess of the plurality of the rings.

16. The preform of claim 1 , wherein the inner surface defining the plurality of rings has a surface area up to 3% greater than a smooth surface area defined by the recess of the plurality of the rings.

17. A preform configured to be molded into a container, the preform comprising: a finish defining an opening; threads on an outer surface of the finish; a preform body configured to form a body of the container; a tip defined by an inner radius and an outer radius at an end of the preform opposite to the finish, the tip configured to form a base of the container, a longitudinal axis of the preform extends through a center of the tip; and a plurality of ridges defined by at least one of an inner surface of the tip and an outer surface of the tip, the inner surface of the tip is opposite to the outer surface of the tip, the plurality of ridges encircling the longitudinal axis and configured to form base rings of the container.

18. The preform of claim 17, wherein the plurality of ridges are at the inner surface of the tip, and the outer surface is smooth.

19. The preform of claim 17, wherein the plurality of ridges are at the outer surface of the tip, and the inner surface is smooth.

20. The preform of claim 17, wherein the plurality of ridges are at the outer surface of the tip, and the inner surface of the tip.

21 . The preform of claim 17, wherein the preform is injection molded and configured to be molded into the container by blow molding.

22. A container formed from a preform, the container comprising: a finish defining an opening; threads at an outer surface of the finish; a body defining a sidewall of the container; and a base configured to support the container upright, the base including a plurality of rings defined by ridges and recesses at an outer surface or inner surface of the base extending around an axial center of the base.

23. The container of claim 22, wherein the recesses have a higher material modulus than the ridges.

24. The container of claim 22, wherein the base includes a portion that is moveable in response to an internal vacuum within the container.

25. The container of claim 22, wherein the base includes a portion that is moveable in response to an external mechanical force.

26. The container of claim 22, wherein the base includes a center push-up portion.

27. The container of claim 22, wherein the plurality of rings are defined by a plurality of ridges and recesses at the outer surface or the inner surface.