Plastic containers, used for filling with juices, sauces etc., often are hot filled and then cooled to room temperature or below for distribution to sell. During the process of hot filling and quenching, the container is subjected to different thermal and pressure scenarios that can cause deformation, which may make the container non-functional or visually unappealing. Typically, functional improvements are added to the container design to accommodate the different thermal effects and pressures (positive and negative) that can control, reduce or eliminate unwanted deformation, making the package both visually appealing and functional for downstream situations. Functional improvements can include typical industry standard items such as vacuum panels and bottle bases to achieve the desired results. However, it is often desirable that these functional improvements, such as vacuum panels, are minimal or hidden to achieve a specific shape, look or feel that is more appealing to the consumer. Additional requirements may also include the ability to make the container lighter in weight but maintain an equivalent level of functionality and performance through the entire hot fill and distribution process.
Existing or current technologies such as vacuum panels in the side wall of the container may be unappealing from a look and feel perspective. Vacuum panels rely on different components to function efficiently and effectively. One of the major components of the efficiency includes the area in which the deformation to internal positive or negative pressure is controlled and/or hidden. Technologies that include a vacuum panel in the base portion are limited by surface area of the container and therefore the efficiency and effectiveness of the panel are likewise limited. Because of this, the shape and surface geometry that define the bottle's appearance, along with the potential to make the bottle lighter, are limited. In addition to surface area, another major factor in the performance of a vacuum panel can be its thickness distribution. Material thickness can play a vital role in how the panel responds to both positive and negative internal pressure. Through surface geometry however, the impact of material distribution can be greatly reduced providing a functional panel that performs consistently as it is intended with a wide process window. Thus there is a need to develop a base with specific surface geometries that utilize the limited base area to address the inconsistencies that are presented during the blow process specific to material distribution and the varying dynamics the container will be exposed to through the product lifecycle, as well as to expand the limits of the containers shape and/or weight while maintaining the functionality needed to perform as intended.
Furthermore, an additional factor for consideration in designing a container for use in a hot-fill application is the rate of cooling. For example, a hot-fill container filled at 180° F. generally must be cooled to at least about 90° F. in about 12-16 minutes for commercial applications. Therefore, a need exists for a container that can accommodate different rates of cooling. Preferably, such a container is capable of accommodating both negative pressures relative to the atmosphere due to such cooling as well as positive pressures due to changes in altitude or the like, internal pressure exerted during the hot-fill and capping process, as well as flexing to retain overall bottle integrity and shape during the cooling process.
In accordance with certain embodiments of the disclosed subject matter, a base for a container is provided. The base includes an outer support wall, a support surface extending inwardly from the outer support wall and defining a reference plane, an inner support wall extending upwardly from the support surface, a first radiused portion extending radially inward from the inner support wall and concave relative to the reference plane, a second radiused portion extending radially inward from the first radiused portion and convex relative to the reference plane, an intermediate surface extending radially inward from the second radiused portion and substantially parallel to the reference plane, a third radiused portion extending radially inward from the intermediate surface and convex relative to the reference plane, and a central portion disposed proximate the third radiused portion.
Additionally, and as embodied herein, the central portion can include an inner core. The inner core can include a sidewall and a top surface extending from the sidewall. The top wall having a convex portion relative the reference plane. The base can further include a transition portion between the third radiused portion and the inner core.
Furthermore, and as embodied herein, the base can include a plurality of ribs extending from the central portion to the support surface and spaced apart to define a plurality of segments between the central portion and the support surface. The support surface can have a width of between about 4% to about 10% the width of the maximum cross-dimension of the base. At least an upper section of the inner support wall can extend inwardly at an angle of between about 15 degrees to about 85 degrees relative the reference plane.
In further embodiments according to the disclosed subject matter, the base additionally includes a fourth radiused portion disposed between the support surface and the inner support wall, and/or a fifth radiused portion disposed between the support surface and the outer support wall. Further in accordance with the disclosed subject matter, a container is provided having a sidewall and a base as disclosed above and in further detail below, wherein the base defines a diaphragm extending generally to the side wall. Further in accordance with the disclosed subject matter, a method of blow-molding such a container is provided.
The apparatus and methods presented herein may be used for containers, including plastic containers, such as plastic containers for liquids. The containers and bases described herein can be formed from materials including, but not limited to, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and PEN-blends, polypropylene (PP), high-density polyethylene (HDPE), and can also include monolayer blended scavengers or other catalytic scavengers as well as multi-layer structures including discrete layers of a barrier material, such as nylon or ethylene vinyl alcohol (EVOH) or other oxygen scavengers. The disclosed subject matter is particularly suited for hot-fillable containers having a base design that is reactive to internal and external pressure due to pressure filling and/or due to thermal expansion from hot filling to provide controlled deformation that preserves the structure, shape and functionality of the container. The container base can also provide substantially uniform controlled deformation when vacuum pressure is applied, for example due to product contraction from product cooling.
In accordance with the disclosed subject matter herein, the disclosed subject matter includes a base for a container having a sidewall. The base includes a support surface defining a reference plane, an inner wall extending upwardly from the support surface, a first radiused portion extending radially inward from the inner wall and concave relative to the reference plane, a second radiused portion extending radially inward from the first radiused portion and convex relative to the reference plane, an intermediate surface extending radially inward from the second radiused portion and substantially parallel to the reference plane, a third radiused portion extending radially inward from the inner surface and convex relative to the reference plane, and an inner core disposed proximate the third radiused portion to define a central portion of the base. The base can also include an outer support wall, which can be an extension of the container side. In additional embodiments in accordance with the disclosed subject matter, the base further includes a fourth radiused portion disposed between the support surface and the inner support wall, and/or a fifth radiused portion disposed between the support surface and the outer support wall. As described further below, each radiused portion defines a hinge for relative movement therebetween, such that at least a portion of the base acts as a diaphragm.
Reference will now be made in detail to the various exemplary embodiments of the disclosed subject matter, exemplary embodiments of which are illustrated in the accompanying drawings. The structure of the base for the container of the disclosed subject matter will be described in conjunction with the detailed description of the system.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the disclosed subject matter. For purpose of explanation and illustration, and not limitation, exemplary embodiments of the base and container with the disclosed subject matter are shown in the accompanying figures. The base is suitable for the manufacture of containers such as, bottles, jars and the like. Such containers incorporating the base can be used with a wide variety of perishable and nonperishable goods. However, for purpose of understanding, reference will be made to the use of the base for a container disclosed herein with liquid or semi-liquid products such as sodas, juices, sports drinks, energy drinks, teas, coffees, sauces, dips, jams and the like, wherein the container can be pressure filled with a hot liquid or non-contact (i.e., direct drop) filler, such as a non-pressurized filler, and further used for transporting, serving, storing, and/or re-using such products while maintaining a desired shape, including providing a support surface for standing the container on a table or other substantially flat surface. Containers having a base described herein can be further utilized for sterilization, such as retort sterilization, and pasteurization of products contained therein. As described in further detail below, the container can have a base configuration to provide improved sensitivity and controlled deformation from applied forces, for example resulting from pressurized filling, sterilization or pasteurization and resulting thermal expansion due to hot liquid contents and/or vacuum deformation due to cooling of a liquid product filled therein. The base configuration can influence controlled deformation from positive container pressure, for example resulting from expansion of liquid at increased temperatures or elevations. For purpose of illustration, and not limitation, reference will be made herein to a base and a container incorporating a base that is intended to be hot-filled with a liquid product, such as tea, sports drink, energy drink or other similar liquid product.
As shown for example in
The central portion 116 can be configured to form a variety of suitable shapes and profiles. For example, and as depicted, the central portion 116 can be provided with an inner core 118. The inner core 118 can have a generally frustoconical shape or the like and can be shallow or deep as desired. By way of example, the inner core 118 can comprise a sidewall 120 and a top surface 122 extending from the sidewall 120, the top surface 122 having a convex portion 124 relative to the reference plane P.
As further defined herein, the radiused portions generally function as hinges to control at least in part the dynamic movement of the base 100. For example, the first radiused portion 108 can be configured as a primary contributor to both the ease with which the base 100 deforms and the amount of deformation. With reference to the exemplary embodiments disclosed in
Each radiused portion can be configured to deform in conjunction with the other. For example, a change to the geometry and/or relative location of either of the third radiused portion 114 or second radiused portion 110 can affect the deformation response of the first radiused portion 108. As described further below, a transition portion 126 between the third radiused portion 114 and the inner core 118 can also be configured to affect the efficiency or response of the base deformation. Furthermore, the length of the intermediate surface 112 can be selected to affect such deformation based upon its relationship with the second and third radiused portions 110, 114. In this manner a diaphragm can be designed and tailored based upon the interactions of these base portions to provide a desired performance and affect.
In addition to the profile of the base 100 as defined by the radiused portion locations, the radius of the transition portion 126 between the inner core 118 and the third radiused portion 114, as well as the conical shape of the inner core 118, can be modified to increase or decrease the spring rate or response to pressure differentials, which can accommodate a range of thermodynamic environments, such as variations in hot-fill filling lines. The base profile can also allow the base 100 to be scaled to containers of different overall shapes such as oval, square or rectangular shapes and different sizes while maintaining consistent thermal and pressure performance characteristics.
The overall design and contour of the base profile, or a portion thereof, can act as a diaphragm responsive to negative internal pressure or vacuum as well as positive internal pressure. The diaphragm can aid in concentrating and distributing axial stress. With reference to the exemplary embodiment of
Further in accordance with the disclosed subject matter, the base, and thus the container, can be configured with any of a variety of different shapes, such as a faceted shape, a square shape, oval shape (see
The base segments 130 can each function independently to provide variable movement of the base 100 and can result in displacement in response to small changes in internal or external changes in container pressure. The combined structure of the individual segments 130 and the ribs 128 dividing the segments 130 can reduce the reaction or displacement to positive pressure while increasing or maintaining sensitivity to negative internal pressure. The base segments 130 can move independently in response to the force or rate of pressure change. Thus, each base segment 130 or area within the segment can provide a secondary finite response to vacuum deformation and product displacement. As such, the combination of segments 130 and dividing ribs 128 can adapt or compensate to variations in wall thicknesses and gate locations among containers formed using base 100 that would otherwise cause inconsistent or incomplete base movement as found in the control. The movement of the segments can be secondary to primary movement or deflection of the overall base diaphragm structure, which can be affected by the base geometry and radiused portions, as described herein.
Current and earlier base technologies have also used mechanical actuation as a method to compensate for product contraction. These technologies have incorporated segments or scallops as part of the design of the base, and in these particular instances, the segments—and specifically the area in between the segments—were needed to provide uniform base movement as the base was mechanically inverted. To achieve this, the area between the segments flex or deform to maintain the shape of the segment and maximize the volume displaced by inversion as all the segments around the circumference of the base invert consistently. Without these breaks in the geometry, the base could invert in an uneven and uncontrolled manner. In the case of the present variable displacement base, the segments 130, either concave or convex in shape when viewing the cross section from the central longitudinal axis out to the major diameter, can react individually as a response to either internal positive or negative pressure. The deformation that occurs reacts in the actual segment surface as opposed to the area in between the segment. It is through this action that the segments 130 can respond individually such that base 100 can respond dynamically to multiple forces and maintain consistent total base deformation.
In this manner, base 100 can respond or deform in a controlled manner from the positive internal pressure. The controlled deformation can prevent the base diaphragm region from extending down past the standing ring, which may define reference plane P or support surface 104, while providing a geometry that can respond dynamically to internal vacuum pressure. Base 100 can exhibit a small degree of relaxation or thermal creep due to hot fill temperatures and the resulting positive pressure from thermal expansion within the container. The environmental effect of temperature, pressure and time can interact with base 100 to provide a controlled deformation shape. Due at least in part to the response of the material to heat and pressure, some elastic hysteresis can prevent base 100 from returning to its original molded shape when all forces are removed. It was discovered through analysis and physical testing that the design of the base profile, segments 130 and ribs 128 would lead to an initial surface geometry that, when subjected to the positive pressure of hot filling and capping, results in a shape that also responds efficiently to internal vacuum pressures. Thus, after hot filling and capping, the resulting shape of base 100 can be considered a preloaded condition from which the bottle base can be designed to respond to vacuum deformation from the negative internal pressure created by product contraction during cooling.
Using the base profile as disclosed, a variety of embodiments can be configured as depicted in the figures, for purpose of illustration and not limitation. For example,
For purpose of understanding and not limitation, a series of graphs are provided to demonstrate various operational characteristics achieved by the base and container disclosed herein.
For purpose of illustration and not limitation, exemplary dimensions and angles shown in
In accordance with another aspect of the disclosed subject matter, a further modification is provided of the base for a container as defined above. That is, the base generally, comprises an outer support wall, a support surface extending inwardly from the outer support wall and defining a reference plane, an inner support wall extending upwardly from the support surface, a first radiused portion extending radially inward from the inner support wall and concave relative to the reference plane, a second radiused portion extending radially inward from the first radiused portion and convex relative to the reference plane, an intermediate surface extending radially inward from the second radiused portion and substantially parallel to the reference plane, a third radiused portion extending radially inward from the intermediate surface and convex relative to the reference plane, and a central portion disposed proximate the third radiused portion as defined in detail above. As disclosed herein, the base further includes a fourth radiused portion disposed between the support surface and the inner support wall and/or a fifth radiused portion disposed between the support surface and the outer support wall. As with the radiused portions previously defined, the fourth radiused portion and the fifth radiused portion herein each generally functions as a hinge for further deformation of the base. Hence, the portion of the base acting as a diaphragm can extend inwardly from the fourth radiused portion to include the inner support wall or inwardly from the fifth radiused portion to further include the support surface.
For purpose of illustration and not limitation, reference is now made to the exemplary embodiment of
In this manner, and as previously described, the radiused portions will function as hinges and can cooperate for dynamic movement of the base as a whole. That is, by providing the fourth radiused portion 750 at the inner edge of the support surface 704, the portion of the base 700 extending inwardly from the fourth radiused portion 750 will act as a diaphragm. Similarly, by providing a fifth radiused portion 752 at the outer support wall 702, the portion of the base 700 extending inwardly from the fifth radiused portion 752 will act as a diaphragm. Depending upon the dimensions of the support surface 704, the diaphragm therefore can comprise at least about 90% of the surface area of the base 700, or even at least about 95% of the surface area.
Furthermore, and as described above, the dimensions and angles of the various features can be selected to tailor the overall performance of the base as desired. For example, the radius and angle of curvature of the various radiused portions, the distances therebetween, and the lengths of the support walls and surfaces can be modified to increase or decrease the spring rate or response to pressure differentials to accommodate a range of thermodynamic environments, such as variations in hot-fill filling lines. Additionally, the angle of curvature of the inner support wall 706 relative to the reference plane P defined by the support surface 704 can be selected for the desired response to pressure differentials to affect the efficiency of the base deformation.
Operation of an exemplary base 700 further having fourth and fifth radiused portions 750, 752 is illustrated schematically with reference to
For example, and as depicted generally in
Particularly,
In accordance with another aspect of the disclosed subject matter, a container is provided having a base as described in detail above. The container generally comprises a sidewall and a base, the base comprising an outer support wall, a support surface extending inwardly from the outer support wall and defining a reference plane, an inner support wall extending upwardly from the support surface, a first radiused portion extending radially inward from the inner support wall and concave relative to the reference plane, a second radiused portion extending radially inward from the first radiused portion and convex relative to the reference plane, an intermediate surface extending radially inward from the second radiused portion and substantially parallel to the reference plane, a third radiused portion extending radially inward from the intermediate surface and convex relative to the reference plane, and a central portion disposed proximate the third radiused portion. As embodied herein, the container sidewall can be coextensive and/or integral with the outer support wall of the base. Other modifications and feature as described above or otherwise known can also be employed.
The various embodiments of the base and of the container as disclosed herein can be formed by conventional molding techniques as known in the industry. For example, the base can be formed by blow-molding with or without a movable cylinder.
For purpose of understanding and not limitation, a series of graphs are provided to demonstrate various operational characteristics achieved by the base and container disclosed herein.
In addition to the specific embodiments claimed below, the disclosed subject matter is also directed to other embodiments having any other possible combination of the dependent features claimed below and those disclosed above. As such, the particular features disclosed herein can be combined with each other in other manners within the scope of the disclosed subject matter such that the disclosed subject matter should be recognized as also specifically directed to other embodiments having any other possible combinations. Thus, the foregoing description of specific embodiments of the disclosed subject matter has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosed subject matter to those embodiments disclosed.
It will be apparent to those skilled in the art that various modifications and variations can be made in the method and system of the disclosed subject matter without departing from the spirit or scope of the disclosed subject matter. Thus, it is intended that the disclosed subject matter include modifications and variations that are within the scope of the appended claims and their equivalents.
This application is a continuation of U.S. application Ser. No. 14/176,891, filed on Feb. 2, 2014, which is a continuation of International Application No. PCT/US14/11433, filed Jan. 14, 2014, which claims priority to U.S. Provisional Application No. 61/752,877, filed Jan. 15, 2013, and U.S. Provisional Application No. 61/838,166, filed Jun. 21, 2013, the disclosure of each of which is incorporated by reference herein in its entirety.
Number | Date | Country | |
---|---|---|---|
61752877 | Jan 2013 | US | |
61838166 | Jun 2013 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 14176891 | Feb 2014 | US |
Child | 15048312 | US | |
Parent | PCT/US2014/011433 | Jan 2014 | US |
Child | 14176891 | US |