Patent Application
20120298541
1. Field of the Invention
This invention relates generally to the field of packaging, and more specifically to the field of blow molded plastic containers for packaging substances such as beverages.
2. Description of the Related Technology
Many products that were previously packaged using glass containers are now being supplied in plastic containers. Polyethylene terephthalate (PET) thermoplastic resins are polyester materials that provide clarity and transparency that is comparable to glass. PET possesses the processing characteristics, chemical and solvent resistance and high strength and impact resistance that are required for packaging products such as juices, soft drinks and water. PET containers are lightweight, inexpensive, and recyclable and can be economically manufactured in large quantities. They will not shatter and create potentially dangerous shards when dropped, as glass containers may.
PET containers have conventionally been manufactured using the stretch blow molding process. This involves the use of a pre-molded PET preform having a threaded portion and a closed distal end. The preform is first heated and then is longitudinally stretched and subsequently inflated within a mold cavity so that it assumes the desired final shape of the container. As the preform is inflated, it elongates and stretches, taking on the shape of the mold cavity. The polymer solidifies upon contacting the cooler surface of the mold, and the finished hollow container is subsequently ejected from the mold.
In order to minimize materials costs, a plastic container should ideally be constructed to use as little plastic resin as possible. Such lightweighting is usually accomplished by making the sidewall of the container as thin as possible, but this adversely impacts the strength and rigidity of the sidewall. In larger plastic beverage containers, such as those having a volumetric capacity of 64 ounces or greater, outward bulging of the sidewall as result of the hydrostatic pressure exerted by the liquid within the container can be problematic, particularly in containers that are noncircular in transverse cross-section.
A need has existed for an improved noncircular plastic container that possesses improved resistance to outward bulging of the sidewall with respect to conventional containers, without having a significant negative impact on material costs.
Accordingly, it is an object of the invention to provide an improved noncircular plastic container that possesses improved resistance to outward bulging of the sidewall with respect to conventional containers, without having a significant negative impact on material costs.
In order to achieve the above and other objects of the invention, a plastic container according to a first aspect of the invention includes a finish portion defining an opening and a main body portion having a shape that is substantially polygonal in transverse cross-section with a plurality of side panels. The main body portion has a maximum lateral dimension. At least one of the side panels includes a substantially flat portion for receiving a label and a concave portion having an average radius. A ratio of the average radius to the maximum lateral dimension is substantially within a range of about 1.0 to about 2.0.
A plastic container according to a second aspect of the invention includes a finish portion defining an opening, and a main body portion having a shape that is substantially polygonal in transverse cross-section with a plurality of side panels. The main body portion has a maximum lateral dimension. At least one of the side panels includes a first upper substantially flat portion for receiving a label, a second, lower substantially flat portion for receiving a label and a central concave portion positioned between the first and second substantially flat portions.
These and various other advantages and features of novelty that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to
Referring to
Label portion 18 includes a plurality of side panels 20, 22, 24, 26, including front and rear side panels 20, 22. At least one of the side panels 20, 22, 24, 26 includes at least one substantially flat portion 28, 30 for receiving a label and a concave portion 32 having an average radius RC. The main body portion 12 has a maximum lateral dimension DMAX, which is best shown in
In the preferred embodiment, the average radius RC is substantially unchanged when viewed in transverse cross-section from an upper portion of the concave portion 32 to a lower portion of the concave portion 32.
In the preferred embodiment, the front and rear side panels 20, 22 each have a first, upper substantially flat portion 28 near an upper end of the respective panel 20, 22 for receiving a first portion of a label and a second, lower substantially flat portion 30 near a lower end of the respective panel 20, 22 for receiving another portion of the label. A central, concave portion 32 is positioned between the upper and lower substantially flat portions 28, 30.
A plurality of reinforcing ribs 34, 36, 38, 40, 42 are preferably defined in each of the front and rear side panels 20, 22. The reinforcing ribs 34, 36, 38, 40, 42 in the preferred embodiment have a substantially horizontal orientation.
Each of the side panels 20, 22 that have the concave portion 32 has an inwardmost portion 44 and an outwardmost portion 46, as
A ratio D1/D2 of the first distance D1 to the second distance D2 is preferably substantially within a range of about 0.8 to about 1.2 and more preferably substantially within a range of about 0.9 to about 1.1.
Reinforcing rib 34 defines a boundary between the first, upper substantially flat portion 28 and the central concave portion 32, and reinforcing rib 42 defines a boundary between the second, lower substantially flat portion 30 and the central concave portion 32. In other words, the portion of the side panel 20, 22 above the reinforcing rib 34 is preferably substantially flat, while the portion of the side panel 20, 22 below the reinforcing rib 34 is preferably concave. Likewise, the portion of the side panel 20, 22 below the reinforcing rib 42 is preferably substantially flat, while the portion of the side panel 20, 22 above the reinforcing rib 42 is preferably concave.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
