PLASTIC CONTAINER WITH FLEXIBLE BASE
A plastic container is disclosed that includes a sidewall portion and a base portion. In embodiments, the base portion includes a flexible base portion configured for a first position, a second position, and a third position in response to internal forces associated with filling and cooling of container contents. The first position is a position following formation or molding, and prior to filling; the second position is a position during or following filling of contents at an elevated temperature, but before cooling or significant cooling of the contents, the second position is vertically lower than the first position; and the third position is a position after cooling of contents and vacuum forces associated with the contents have been substantially addressed, the third position is vertically higher than the first position.
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This application is a continuation-in-part of U.S. patent application Ser. No. 12/648,647, filed Dec. 29, 2009, currently pending, which claims the benefit of U.S. Provisional Application No. 61/141,812, filed Dec. 31, 2008. This application is also a continuation-in-part of U.S. patent application Ser. No. 12/702,370, filed Feb. 9, 2010 currently pending, which claims the benefit of U.S. Provisional Application No. 61/151,363, filed Feb. 10, 2009. This application additionally claims the benefit of U.S. Provisional Application No. 61/665,441, filed Jun. 28, 2012, and U.S. Provisional Application No. 61/716,932, filed Oct. 22, 2012. The entire contents of all of the foregoing applications are incorporated herein by reference in their entireties.
TECHNICAL FIELDThe present disclosure generally relates to the field of plastic containers, including plastic containers, which may be lightweighted, and employ features to accommodate pressurization and/or hot-fill conditions.
BACKGROUNDCurrently a significant number of plastic containers are filled with liquids and other contents at elevated temperatures. However, as the product or contents within the container cools, the volume taken up by the product or contents decreases, which can lead to the creation of vacuum forces within the container. Containers that are intended to be filled by a “hot-fill” process are commonly referred to as hot-fill containers. The design of hot-fill containers is influenced by, among other things, a desire to account for anticipated product or content cooling/shrinkage and associated forces. There is also an active interest in the industry to lightweight such containers without sacrificing desired function.
SUMMARYA plastic container is disclosed that includes a sidewall portion and a base portion. Plastic containers in accordance with the teachings of the disclosure may be made of comparatively lighter weights (or “lightweighted”), and further may be configured to address internal vacuum forces in a desired manner. In embodiments, the container may be configured to create a greater/expanded differential to provide increased vacuum absorption.
Embodiments of the disclosure will now be described, by way of example, with reference to the accompanying drawings, wherein:
Reference will now be made in detail to embodiments of the present disclosure, examples of which are described herein and illustrated in the accompanying drawings. While the invention will be described in conjunction with embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the disclosure and appended claims.
The container 10 may be comprised of one or more various polymers including, without limitation, polyethylene terephthalate (PET) and/or various other polymers commonly utilized with hot-fill-type plastic containers. In embodiments the container may also be biaxially oriented, which may be the result of, for example, a stretch blow-molding process. The invention is not, however, limited to the type or style of container shown, and various other sizes and configurations may come within the scope and spirit of the present disclosure.
An embodiment of a base 30 is generally illustrated in
With further reference to
As generally illustrated in connection with the shift or transition of positions (i.e., from first position 42 to second position 44, and then to third position 46), the base portion 40 initially goes down. That is, following filling, the base portion 40 generally decreases in height above the support surface from first position 42 to second position 44. This movement or shift may be due, for instance, to the temperature of filled contents (such as a hot-filled liquid) and the associated hydrostatic pressure. Notably, this initial shift downward of the base portion 40 (e.g., to second position 44) can create or provide a greater “differential” (e.g., the internal spacial or volumetric difference between the second position and the third position). Such an increased or expanded differential can, for example, allow for greater vacuum absorption than if the base portion 40 were to remain in the first position 42 during/through hot-filling. With embodiments, the point P may generally remain essentially disposed in substantially the same position whether the base portion 40 is in a first position 42, a second position 44, or a third position 46.
With further reference to
In embodiments, the volumetric displacement between the second position and the third position may be at least twice the volumetric displacement between the first and third position. Moreover, for some embodiments, the volumetric displacement between the second position and the third position may be at least three times the volumetric displacement between the first and third position. For example and without limitation, the differential between the first position 42 and third position 46 for a 20 fl. oz. container may be about 5 ml of potential volumetric displacement. However, by configuring the base portion 40 to shift to a second position 44 before vacuum absorption, the potential volumetric displacement (between the second position and the third position) may increase to about 17 ml.
Moreover, in contrast to some prior art containers, the base flexibility does not require additional mechanical assistance. Rather, the base portion 40 may be configured for movement from a first position 42 down to a second position 44 and then up to a third position 46 based entirely upon reaction to internal fill temperature and cooling effects. With such embodiments, no additional external equipment may be necessary to mechanically facilitate the movement of the base portion as such.
The base portion 40 may employ base configuration teachings such as those included in the teachings of U.S. patent application Ser. No. 12/648,647, which is incorporated herein in its entirety by reference, and may include portions configured to, among other things, move or flex in response to internal vacuum pressure/forces. In embodiments, the base 30 can be configured to accommodate nearly all or substantially all of the internal vacuum pressure or forces (particularly as compared to the sidewall portions of the container) that may be occasioned by or associated with the cooling of a hot-fill product or contents.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and various modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to explain the principles of the invention and its practical application, to thereby enable others skilled in the art to utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
Claims
1. A plastic container comprising:
- a sidewall portion; and
- a base including a flexible base portion configured for a first position, a second position, and a third position in response to internal forces associated with filling and cooling of container contents;
- wherein the first position is a position following formation or molding, and prior to filling; the second position is a position during or following filling of contents at an elevated temperature, but before cooling or significant cooling of the contents, the second position is vertically lower than the first position; and the third position is a position after cooling of contents and vacuum forces associated with the contents have been substantially addressed, the third position is vertically higher than the first position.
2. The plastic container of claim 1, wherein the flexible base portion includes a point configured to function as a hinge point for the first position, second position, and third position.
3. The plastic container of claim 2, wherein the point remains disposed in substantially the same position in the first position, the second position, and the third position.
4. The plastic container of claim 1, wherein the sidewall portion is configured to be rigid and substantially resist internal vacuum forces associated with the container.
5. The plastic container of claim 1, wherein the volumetric displacement between the second position and the third position is at least twice the volumetric displacement between the first and third position.
6. The plastic container of claim 1, wherein the volumetric displacement between the second position and the third position is at least three times the volumetric displacement between the first and third position.
7. The plastic container of claim 1, wherein, the plastic container is a plastic container configured to hold 20 fl. oz. and the differential between the first position and third position is about 5 ml of volumetric displacement, and the volumetric displacement between the second position and the third position is about 17 ml.
8. The plastic container of claim 1, wherein the container is comprised of polyethylene terephthalate (PET).
9. The plastic container of claim 1, wherein the container is biaxially oriented.
10. A method for filling a plastic container with a flexible base, the method comprising:
- providing a plastic container including a flexible base portion configured in a first position;
- filling the container with contents at an elevated temperature such that that base portion moves to a second position that is vertically lower than the first position;
- permitting the container contents to cool such that the base portion moves to a third position that is vertically higher than the first position.
11. The method of claim 10, wherein the plastic container includes a sidewall portion that is configured to be rigid and substantially resist internal vacuum forces associated with the container.
12. The method of claim 10, wherein the volumetric displacement between the second position and the third position is at least twice the volumetric displacement between the first and third position.
13. The method of claim 10, wherein the volumetric displacement between the second position and the third position is at least three times the volumetric displacement between the first and third position.
14. The method of claim 10, wherein the flexible base portion moves from the second position to the third position without mechanical forces being imparted on the base portion.
Type: Application
Filed: Mar 15, 2013
Publication Date: Aug 22, 2013
Applicant: Plastipak Packaging, Inc. (Plymouth, MI)
Inventor: Plastipak Packaging, Inc.
Application Number: 13/841,363
International Classification: B65D 1/40 (20060101); B65B 3/04 (20060101);