US20190322406A1

US20190322406A1 - Container base constructions and methods of making the same

Info

Publication number: US20190322406A1
Application number: US15/958,677
Authority: US
Inventors: Irene Makarchuk; Daniel A. Landan; Roman D'Alessandro; Victor Ivenitsky; Sameh Guirguis
Original assignee: Inline Plastics Corp
Current assignee: Inline Plastics Corp
Priority date: 2018-04-20
Filing date: 2018-04-20
Publication date: 2019-10-24

Abstract

Disclosed are container base constructions and methods of making the same. Such container are adapted and configured to reduce or eliminate deformation of the base and/or sidewall when the container is filled and/or stacked. The containers have a sidewall that has a top end and a bottom end; and a base attached to the bottom end of the sidewall. The base of the container includes a center panel which is positioned above the bottom end of the sidewall and an outer convex section. In certain constructions, the center panel is flat. Alternatively, the center panel can be curved (e.g., convex).

Description

FIELD OF THE INVENTION

The present disclosure is directed to container base constructions and methods of making the same, and more particularly to, containers that have a base which is adapted and configured to reduce or eliminate deformation of the base and/or sidewall when the container is filled and/or stacked.

BACKGROUND OF THE INVENTION

When a thermoplastic container or cup is filled with a product, typically a liquid, and then sealed, internal pressure can be created within the container. As a result, the base and/or sidewall of the container often bulge/deform. This is particularly a problem when the walls of the cup are thin, or otherwise not sufficiently rigid to prevent the bulging or deformation. This is increasingly the case as manufacturing targets require minimal use of material or where the aim is to reduce the overall weight of the container. This deformation results in a number of possible problems, including altering the appearance of the container to the point that consumers may not purchase or would otherwise return a product in a container with bulging or deformed walls. Furthermore, when such containers are to be stacked on store shelves, for example, bulging may have a negative impact on the stackability of the containers.
As is known in the art, it is possible to mitigate some of the effects of bulging by designing containers with thicker walls, or incorporating other strengthening or structural elements into the container walls. However, these solutions are not always possible or can lead to increased material costs, container weight and other manufacturing and/or design inefficiencies.
There is a need therefore, for container base constructions and methods of making the same, and more particularly to, containers that have a base which is adapted and configured to reduce or eliminate deformation of the base and/or sidewall when the container is filled and/or stacked.

SUMMARY OF THE INVENTION

The purpose and advantages of the below described illustrated embodiments will be set forth in and apparent from the description that follows. Additional advantages of the illustrated embodiments will be realized and attained by the containers and methods particularly pointed out in the written description and the claims herein, as well as from the drawings.
To achieve these and other advantages and in accordance with the purpose of the illustrated embodiments, in one embodiment, described herein is a container that includes a sidewall that has a top end and a bottom end; and a base attached to the bottom end of the sidewall. A cavity is bounded by or defined by the sidewall and the base. The base of the container includes a center panel which is positioned above the bottom end of the sidewall and an outer convex section. In certain constructions, the center panel is flat. Alternatively, the center panel can be convex.
In embodiments of the present disclosure, an inner panel connects the center panel to the outer convex section of the base. It is envisioned that in constructions wherein the container is round, the inner panel can be ring-shaped. In such constructions, a cross-section taken through the sidewall is circular and defines a longitudinal axis for the container. Moreover, in such embodiments the base has a cross section that is axially symmetrical.
It is envisioned that the container can further include a lid which engages with the sidewall to form a leak resistant or proof seal. Moreover, the container can also include a hinge joining the lid to the sidewall of the container.
In certain embodiments, a material thickness is the same for the lid, sidewall and base. In such constructions, the base, sidewall, lid and hinge can be formed from a single sheet of material. However, in certain constructions the thickness of the lid, sidewall and base can vary. For example, it could be advantageous to form the lid using a thinner material. It is envisioned that the material used to form the container can be a polymer and the container can be thermoformed from a single sheet of material.
It is also envisioned that in certain embodiments, the sidewall is formed at an angle greater than 90 degrees with respect to the base and/or the surface upon which the container will rest.
Preferably, the deflection of the center panel of the base does not exceed 0.029 inches when the container is fully loaded.
The present disclosure is also directed to a further container embodiment that includes a sidewall having a top end and a bottom end; and a base attached to the bottom end of the sidewall and defining a cavity bounded by the sidewall and the base. In such a construction, the base includes a flat center panel and an outer convex section. The center panel is positioned above the bottom end of the sidewall.
The present disclosure is further directed to a container embodiment that includes a sidewall that has a top end and a bottom end; and a base attached to the bottom end of the sidewall. The base and the sidewall cooperate to define a cavity. In this embodiment, the base includes a convex center panel and an outer convex section, wherein the convex center panel is positioned above the bottom end of the sidewall.
The present disclosure is further directed to a container that includes a sidewall having a top end and a bottom end; and a base attached to the bottom end of the sidewall. A cavity is defined by the sidewall and the base. In this embodiment, the base includes a flat center panel and an outer convex section, wherein the center panel is positioned above the bottom end of the sidewall and is joined to the outer convex section through an inner ring panel.
Still further, the present disclosure is directed to a method of forming a container that includes the steps of: forming a lid from a portion of a single sheet of at least partially transparent plastic material; forming a sidewall from a second portion of the single sheet of at least partially transparent plastic material, the sidewall having a top end and a bottom end; and forming a base from a third portion of the single sheet of at least partially transparent plastic material, the base being attached to the bottom end of the sidewall defining a cavity bounded by the sidewall and the base, the base including a center panel and an outer convex section, wherein the center panel is positioned above the bottom end of the sidewall. In certain embodiments, the single sheet of at least partially transparent plastic material is entirely transparent.
It is envisioned that the center panel can be flat, convex or concave. Moreover, in certain embodiments, an inner panel connects the center panel to the outer convex section of the base. Preferably, in round containers, the inner panel is ring-shaped. Additionally, the sidewall has a circular cross-section and defines a longitudinal axis for the container and the base has a cross section that is axially symmetrical.
Preferably, the lid is formed so as to engage with the top end of the side wall and form a leak resistant or leak proof seal. Additionally, the disclosed method can further include the step of forming a hinge that joins the lid to the sidewall of the container from the single sheet of plastic material. Preferably, in certain constructions at least one line of weakness is formed in the hinge. In is envisioned that the single sheet of plastic material can have a uniform material thickness such that the lid, sidewall and base each are formed having the same thickness.
The disclosed method can further include the step of forming the sidewall at an angle greater than 90 degrees with respect to the base. It is envisioned that the step of forming the sidewall further includes forming an upwardly projecting bead at the top end of the sidewall which extends substantially about the perimeter of the container and is configured to substantially surround a peripheral edge of the lid and hinder access to the container when the container is closed.
The disclosed method can further include the step of forming vents in the container to promote airflow therethrough.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art, to which the present embodiments pertain, will more readily understand how to manufacture the novel containers and employ the novel methods, certain illustrated embodiments thereof will be described in detail herein-below with reference to the drawings, wherein:

FIG. 1A is a perspective view of a container which has been constructed in accordance with an embodiment of the present disclosure showing the container in the open position;

FIG. 1B is a perspective view of the container of FIG. 1A shown in the closed position;

FIGS. 2A-B provide a top plan view and elevational view of the open container of FIG. 1A;

FIGS. 3A-B provide a top plan view and elevational view of the closed container of FIG. 1B;

FIG. 4 provides a cross-section of the base of a prior art container;

FIG. 5 provides a cross-section of the base of a container which has been constructed in accordance with an embodiment of the present disclosure and includes a flat center panel, an inner ring panel and an outer convex section;

FIG. 6 provides a cross-section of the base of a container which has been constructed in accordance with a further embodiment of the present disclosure and includes a convex center panel and an outer convex section;

FIG. 7 provides a cross-section of the base of a container which has been constructed in accordance with yet a further embodiment of the present disclosure and includes a flat center panel and an outer convex section;

FIGS. 8A-8B illustrate the test setup for determining the deflection of the bottom panel of a loaded container;

FIG. 9 provides a boxplot graphical illustration of the amount of deflection of the center panel for four container embodiments.

FIG. 10 provides a boxplot graphical illustration of the amount lift deflection occurring around the bottom edge of the sidewall of four container embodiments; and

FIG. 11 provides a boxplot graphical illustration of the amount lift deflection occurring around the bottom edge of the sidewall of four container embodiments for a double stack of containers.

These and other aspects of the subject invention will become more readily apparent to those having ordinary skill in the art from the following detailed description of the invention taken in conjunction with the drawings.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The below illustrated embodiments are directed to container base constructions and methods of making the same, and more particularly to, containers that have a base which is constructed to reduce or eliminate deformation of the base and/or sidewall when the container is filled and/or stacked during shipment and retail. It is to be appreciated the below illustrated embodiments are not limited in any way to what is shown, as the illustrated embodiments described below are merely exemplary of the invention, which can be embodied in various forms, as appreciated by one skilled in the art. Therefore, it is to be understood that any structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative for teaching one skilled in the art to variously employ the certain illustrated embodiments.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art relating to the below illustrated embodiments. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the below illustrated embodiments, exemplary methods and materials are now described.
Referring now to FIGS. 1A-1B, 2A-2B and 3A-3B, there is illustrated a container which has been constructed in accordance with an embodiment of the present invention that has been designated as reference numeral 100. Container 100 is a round cup but those skilled in the art will readily appreciated that other size and shape containers, vessels, etc. can be used without departing from the scope of the present disclosure.
Container 100 includes a sidewall 20 that has a top end 24 and a bottom end 22. A base 40 is attached to the bottom end 22 of the sidewall 20. A cavity 50 is bounded by or defined by the sidewall 20 and the base 40. As shown in FIGS. 2B and 3B, the sidewall 20 of container 100 is formed at an angle α that is greater than 90 degrees with respect to the base 40 or surface upon which the container will rest.
The container 100 further includes a lid 60. Lid 60 includes a flat center panel 62 which is surrounded by a peripheral sealing surface 64. The top end 24 of the sidewall includes an upper peripheral rim 26 and a sealing surface 28 (see FIG. 2B) which engages with a sealing surface 64 associated with the lid 60 to form a leak resistant seal.
In the embodiment shown in FIGS. 1A-3B, container 100 also includes a hinge 70 joining the lid 60 to the sidewall 20 of the container 100. As a result, container 100 is a single piece construction. However, those skilled in the art will appreciate that container 100 could be a two-piece construction without departing from the scope of the present invention. Moreover, containers constructed in accordance with the teachings of this disclosure do not need a lid and may simply include a foil cover or some other type of closure mechanism.
Referring now to FIGS. 4-7 which illustrate various base constructions which can be used with container 100. FIG. 4 illustrates a prior art base construction which is referred to as base 140. As shown in this figure, base 140 includes a raised, flat center panel 142, an angled inner panel 144 and a flat outer panel 146 which would sit flat upon the supporting surface. The inventors of the present invention have learned through experience that containers which have been constructed to have a base as shown in FIG. 4 tend to deform or bulge when fully loaded. It was determined that the flat outer panel 146 acted as a lever which facilitated deformation of the base and sidewall when the container was loaded. More specifically, as will be described in detail below, when the container is loaded the weight of the product will cause the center panel 142 to deflect downward which in turn causes the outer edge 148 of the base 140 to lift off the supporting surface. This makes the container particularly unsuitable for stacking.
Referring now to FIGS. 5-7 which illustrates three base embodiments which have been constructed in accordance with the present invention and have been identified using reference numerals 240, 340 and 440, respectively.
As shown in FIG. 5, base 240 includes a flat center panel 242, an inner ring panel 244 and an outer convex panel 246. As can be readily seen, a smooth, radiused transition is made between the center panel 242 and inner ring panel 244 and the outer convex panel 246. In each of the disclosed embodiments, the base 240/340/440 of the container 100 includes a center panel 242/342/442 which is positioned above the bottom end 22 of the sidewall 20 and an outer convex section 246/346/446.
As shown in FIG. 6, base 340 includes a convex center panel 342 and an outer convex panel 346. As can be readily seen, a smooth, radiused transition is made between the center panel 342 and the outer convex panel 346.
As shown in FIG. 7, base 440 includes a flat center panel 442 and an outer convex panel 446. As can be readily seen, a smooth, radiused transition is made between the center panel 442 and the outer convex panel 446.
The above described constructions illustrate round containers or cups and in such embodiments, the inner panel and out convex panel are ring-shaped. However, as noted about the container does not need to be round and could be other shapes, such as square or oval.
Referring now to FIGS. 8A and 8B which illustrate a bench test set-up for determining the deflection of the base center panel when the container is loaded. An exemplary testing procedure can be summarized as follows:
1. Place an empty container into the test fixture;
2. Zero out the dial indicator;
3. Pour 2 lbs of water into the container; and
4. Record the measurement on the dial indicator.
The prior art container of FIG. 4 and each of the containers shown in FIGS. 5-7 where tested. The results obtained for the three base embodiments were as follows:


	Deflection Under 2 Lbs of H2O in Inches

	Sample #	Base	440	Base 240	Base 340

1	0.03	0.028	0.02
2	0.029	0.029	0.021
3	0.029	0.026	0.02
4	0.029	0.028	0.019
5	0.026	0.024	0.018
6	0.0255	0.024	0.0185
7	0.0235	0.025	0.016
8	0.024	0.026	0.018
9	0.023	0.028	0.017
Ave.	0.027	0.026	0.017

This data was converted into a BOX PLOT which is shown in FIG. 9. FIG. 9 also includes the data from prior art base 140. The data readily illustrates that the prior art base 140 exhibited the largest amount of deflection as compared to the others. Worth noting is the fact that the prior art container that was tested had a material thickness of 51.2 mil while the containers having base constructions 240, 340 and 440 had a material thickness of only 45.3 mil. Of the three base constructions, base 340 performed the best.
The deflection occurring at the bottom of the sidewall was also measured for these same four containers constructions and data representing the deflection in a single stack of containers and a double stack of containers is shown in the BOX PLOTS provided in FIGS. 10 and 11 respectively. As shown therein, the containers having base constructions 240, 340 and 440 did not exhibit any lift at the bottom of the sidewall or lift off of the supporting surface while that prior art base design 140 despite being a thicker gauge container lifted significantly.
As shown in the figures, each of the containers described herein includes tamper resistant and tamper evident features. These features are similar to those described in U.S. Pat. Nos. 7,073,680; 7,118,003; 8,795,580; 9,132,942 and 9,527,640 which are herein incorporated by reference to the extend they do not conflict with the present disclosure.
Still further, an exemplary method for constructing the previously described containers of the present disclosure can include the following steps the order of which can vary:
1. Forming a lid from a portion of a single sheet of at least partially transparent plastic material;
2. Forming a sidewall from a second portion of the single sheet of at least partially transparent plastic material, the sidewall having a top end and a bottom end; and
3. Forming a base from a third portion of the single sheet of at least partially transparent plastic material, the base being attached to the bottom end of the sidewall defining a cavity bounded by the sidewall and the base, the base including a center panel and an outer convex section, the center panel being positioned above the bottom end of the sidewall.
The method can further include the step of forming a hinge that joins the lid to the sidewall of the container from the single sheet of plastic material. Preferably, the single sheet of plastic material has a uniform material thickness such that the lid, sidewall and base each are formed having the same thickness. The disclosed method can further include the steps of: forming the sidewall at an angle greater than 90 degrees with respect to the base and forming vents in the container to promote airflow therethrough.
The techniques described herein are exemplary, and should not be construed as implying any particular limitation on the present disclosure. It should be understood that various alternatives, combinations and modifications could be devised by those skilled in the art. For example, steps associated with the processes described herein can be performed in any order, unless otherwise specified or dictated by the steps themselves. The present disclosure is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.
The terms “comprise”, “include”, and conjugations thereof are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components or groups thereof.
Although the containers and methods of the subject invention have been described with respect to the embodiments disclosed above, those skilled in the art will readily appreciate that changes and modifications may be made thereto without departing from the spirit and scope of the subject invention as defined by the appended claims.

Claims

1. A container comprising:

a frustoconical sidewall having a top end and a bottom end; and

a base attached to the bottom end of the sidewall defining a cavity bounded by the sidewall and the base, the base including a center panel and an outer convex section, the center panel being positioned above the bottom end of the sidewall, wherein the outer convex section arcuately projects from the bottom end of the sidewall inwardly and upwardly,

wherein the bottom end of the sidewall defines a bottom plane of the container and the sidewall extends radially outward at an angle greater than 90 degrees with respect to the bottom plane.

2. The container as recited in claim 1, wherein the center panel is flat.

3. The container as recited in claim 1, wherein the center panel is convex.

4. The container as recited in claim 1, wherein an inner panel connects the center panel to the outer convex section of the base.

5. The container as recited in claim 4, wherein the inner panel is ring-shaped.

6. The container as recited in claim 1, wherein the sidewall is cylindrical and defines a longitudinal axis for the container and the base has a cross section that is axially symmetrical.

7. The container as recited in claim 1, further comprising a lid which engages with the sidewall to form a leak resistant seal.

8. The container as recited in claim 7, further comprising a hinge joining the lid to the sidewall of the container.

9. The container as recited in claim 1, wherein a material thickness is different for the lid, sidewall and base.

10. The container as recited in claim 1, wherein the sidewall is formed at an angle greater than 90 degrees with respect to a surface upon which the container will rest.

11. The container as recited in claim 1, wherein the base, sidewall, lid and hinge are formed from a single sheet of material.

12. The container as recited in claim 1, wherein a deflection of the center panel of the base does not exceed 0.029 inches when the container is fully loaded.

13. The container as recited in claim 1, wherein the container is made from a thermoformed polymer.

14. A container comprising:

a frustoconical sidewall having a top end and a bottom end; and

a base attached to the bottom end of the sidewall defining a cavity bounded by the sidewall and the base, the base including a flat center panel and an outer convex section, the center panel being positioned above the bottom end of the sidewall, wherein the outer convex section arcuately projects from the bottom end of the sidewall inwardly and upwardly,

wherein the bottom end of the sidewall defines a bottom plane of the container and the sidewall extends at an angle greater than 90 degrees with respect to the bottom plane.

15. A container comprising:

a frustoconical sidewall having a top end and a bottom end; and

a base attached to the bottom end of the sidewall defining a cavity bounded by the sidewall and the base, the base including a convex center panel and an outer convex section, the convex center panel being positioned above the bottom end of the sidewall, wherein the outer convex section arcuately projects from the bottom end of the sidewall inwardly and upwardly,

16. A container comprising:

a frustoconical sidewall having a top end and a bottom end; and

a base attached to the bottom end of the sidewall defining a cavity bounded by the sidewall and the base, the base including a flat center panel and an outer convex section, the center panel being positioned above the bottom end of the sidewall and joined to the outer convex section through an inner ring panel, wherein the outer convex section arcuately projects from the bottom end of the sidewall inwardly and upwardly,