US20060091139A1

US20060091139A1 - Thermally insulated containers

Info

Publication number: US20060091139A1
Application number: US10/976,908
Authority: US
Inventors: Kevin Grogan; Kenneth Harris; John Trease; Doug Stein
Original assignee: SCA Packaging North America Inc
Current assignee: Sonoco Development Inc
Priority date: 2004-11-01
Filing date: 2004-11-01
Publication date: 2006-05-04

Abstract

A thermally insulated container includes a base having a bottom wall and sidewalls, and a lid. A liquid-impermeable and moisture-resistant film overlays the outer surface of the base and sidewalls and can extend inside of the base. The film can be plastic shrink wrap film. The sidewalls of the base can be tapered to allow the containers to be nested in a stacked arrangement.

Description

BACKGROUND

The invention is directed to thermally insulated containers and to methods of making the containers.
Thermally insulated containers for containing cold and frozen substances, such as medical products, food, and beverages, are typically made of molded plastic materials that have low thermal conductivity so that such substances can be kept cold, frozen or warm for extended periods of time.
An exemplary transport container described in WO 02/085749 A1 includes a rigid liner, a plurality of layers of flexible insulating material around the liner, an envelope containing the layers and shrunk against the layers, and a cavity within the rigid liner to receive a product to be transported in the transport container.
An object is to provide alternative insulated containers, as well as methods of making the containers.

SUMMARY

An embodiment of an insulated container system, comprising a rigid foam container having a bottom wall including an outer surface, a plurality of sidewalls each including an outer surface and an inner surface; and a film which overlays the outer surface of the bottom wall and of each of the sidewalls and which forms an outer surface of the base; and a lid configured to cover an open end of the rigid foam container opposite the bottom wall.
Another embodiment of the thermally insulated container is provided, which comprises a base including a bottom wall, a plurality of sidewalls and a liquid-impermeable and moisture-resistant film. The bottom wall includes an outer surface. Each of the sidewalls is tapered and includes an outer surface and an inner surface. The film overlays at least the outer surface of the bottom wall and the outer surface of each of the sidewalls and forms the outer surface of the base. The container comprises an optional lid configured to cover an open end of the base.
Another embodiment of a rigid, thermally insulated container system, comprising a rigid styrofoam container having a bottom wall and a plurality of sidewalls integrally connected to the bottom wall; a liquid-impermeable and moisture-resistant film overlaying an outer surface of the bottom wall and each of the sidewalls and providing an outer surface of the base; and indicia on the film at the outer surface of at least one of the sidewalls; and a lid configured to cover an open end of the base opposite the bottom wall.
Methods of making the thermally insulated containers are also provided.

DRAWINGS

FIG. 1 is a side view of an exemplary embodiment of a thermally insulated container.
FIG. 2 is a bottom perspective view of the thermally insulated container shown in FIG. 1.
FIG. 3 is an exploded view showing the interior of the base and the lid of another exemplary embodiment of the thermally insulated container with tapered sidewalls.
FIG. 4 is a side view of another exemplary embodiment of the thermally insulated container with contoured sidewalls.
FIG. 5 is a side view of another exemplary embodiment of the thermally insulated container with contoured sidewalls and a carrying handle.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

FIGS. 1 and 2 depict an embodiment of a thermally insulated container 10. The container 10 is preferably rigid (i.e., non-collapsible) and portable sized so that it can be carried by an individual. The container 10 comprises a base 12 and a removable lid 14. The base 12 includes sidewalls 16 and a bottom wall 18 together defining the open interior (not shown) of the base 12. The base 12 can typically include four sidewalls. The sidewalls 16 include an outer surface 20 and an inner surface (not shown). The bottom wall 16 includes an outer surface 24 and an inner surface (not shown). The lid 14 is configured to cover the open end of the base 12 opposite to the bottom wall 18.
The base 12 and lid 14 are composed of a material that has low thermal conductivity so that the container 10 is thermally insulated. Accordingly, the container 10 can be used to store and transport cold, frozen, or heated substances. For example, the container 10 can be used to store various hot or cold liquids and solids, such as hot or cold beverages, food and medical products. An exemplary suitable material for making the base 12 and lid 14 is expanded polystyrene (EPS). EPS is a lightweight, rigid foam plastic having low thermal conductivity. Another suitable material for making the base 12 and lid 14 is polyethylene.
However, although EPS, for example, can provide desirable thermal insulation properties, it has been determined that liquids, such as water from melting ice, can eventually permeate through such materials and cause leakage from the container to occur. To reduce or completely eliminate such leakage of liquids, the container 10 may include a film 28, preferably liquid-impermeable and moisture-resistant film, applied to overlay portions of the container, preferably the outer surface 24 of the bottom wall 18 and at least the outer surface 20 of each of the sidewalls 16. The film 28 forms the outer surface of the base 12. The film 28 is preferably a plastic shrink-wrap film applied on the base 12 to form a sealed fit to at least the outer surface 24 of the bottom wall 18 and the outer surface 20 of the respective sidewalls 14.
The film 28 can be composed of any suitable material that is liquid-impermeable and moisture-resistant and can be applied to the base 12 by a shrink fitting process. The film 28 preferably is durable and sufficiently thick to resist tearing and other wear caused by contact with other surfaces or objects. For some retail and medical applications of the container 10, the liquid-impermeable and moisture-resistant material preferably is stain resistant. Exemplary materials for the film 28 that provide suitable properties for use in the container 10 are polyethylene and polyethylene blends.
The film 28 can be applied on the base 12 by any suitable heat-shrink process. For example, a plastic shrink bag having an open end can be pulled over the base 12 and then placed in a heated atmosphere, such as in a heat tunnel or the like, to heat the bag to a sufficiently high temperature to shrink the bag tightly around the bottom wall 18 and sidewalls 16 to provide a liquid-impermeable and moisture-resistant barrier on the outside of the base 12.
The process conditions used for the heat shrink process can be selected based on various factors, including the container material, the container wall thickness, the shrink wrap film composition, and the length of the heated region, preferably a heat tunnel, through which the container and shrink wrap film are conveyed. For example, a container composed of EPS and a polyethylene film can typically be heated at a temperature of from about 150° C. to about 260° C. The dwell time, which is the amount of time that the container and film are heated in the heated region, can typically be from about 15 seconds to about 60 seconds.
FIG. 3 shows another exemplary embodiment of the thermally insulated container 100. In this embodiment, the film 28 covers the outer surface of the bottom wall, the outer surface of the sidewalls 16, the upper surface 30 of the sidewalls, and drapes over at least a portion of the inner surface 22 of each of the sidewalls 16 in the interior 19 of the base 12. The lid 14 is configured to form a friction fit with the base 12 and keep tight extra moisture-resistant film 28 inside the base 12. Alternatively, a portion of the film 28 resulting from the shrink fitting process can be trimmed off so that the film 28 covers only the outer surfaces 20, 24 of the bottom wall 18 and sidewalls 16, respectively, and the upper surface 30 of the sidewalls 16.
As shown in FIGS. 1-3, indicia 32, such as colored or black and white graphics, bar code labels, or the like can be provided on the film 28 at any one, or up to all four, of the sidewalls 16 and/or on the bottom wall 18. The indicia 32 can be pre-printed at one or more locations on the inner and/or inner surface of the film 28 prior to the shrink-fitting process. The pre-printed film 28 can be fitted on the base 12 so that the indicia 32 are located at one or more desired location(s) of the sidewalls 16 and/or bottom wall 18 following the heat shrinking process. By providing indicia on the film 28, which can be shrink fitted onto flat and/or contoured surfaces, as opposed to printing the indicia directly on the sidewalls and/or bottom wall of the container, the indicia advantageously can be provided on insulated containers that can have non-tapered, tapered or contoured sidewalls, as described in greater detail below.
In the embodiment of the container 10 shown in FIGS. 1 and 2, the sidewalls 16 are perpendicular to the bottom wall 18 of the base 12. In other embodiments, the sidewalls can be tapered relative to the bottom wall. As used herein, the term “tapered” means that the sidewalls are non-perpendicular to the bottom wall; i.e., the sidewalls are oriented at an obtuse angle relative to the bottom wall. The obtuse angle is preferably from about 100° to about 130°. For example, in the container 100 shown in FIG. 3, the base 12 includes tapered sidewalls 16, which have flat (i.e., planar) outer surfaces 20. Multiple containers 100 having such tapered sidewalls can be stacked in a nested arrangement. Accordingly, retailers, for example, can stack multiple containers 100 on a single floor space, without having to use shelf space. By nesting the containers 100, freight costs associated with transporting the containers can be reduced. The film 28 forming the outer surface of the base 12 advantageously can reduce friction and allow nested containers 100 to be more easily lifted and separated from such stacks.
FIG. 4 depicts a container 200 according to another embodiment. The container 200 includes tapered sidewalls 16, which are contoured (i.e., non-planar) for aesthetic appeal. Indicia 32 can be provided on the film 28 at one or more of the sidewalls 16 and/or the bottom wall of the container 200.
FIG. 5 depicts a container 300 according to another embodiment. The container 300 includes a carrying handle 34. The sidewalls of the container 300 include a tapered lower portion 16′ and an upper portion 16″. The tapered lower portion 16′ allows multiple containers 300 to be nested in a stacked arrangement. Indicia 32 can be provided on the film 28 at one or more of the sidewalls and/or the bottom wall of the container 300.
The foregoing has described principles, preferred embodiments and modes of operation of the invention. However, the invention should not be construed as being limited to the particular embodiments discussed. Thus, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the invention as defined by the following claims.

Claims

1. An insulated container system, comprising:

a rigid foam container having a bottom wall including an outer surface, a plurality of sidewalls each including an outer surface and an inner surface; and

a film which overlays the outer surface of the bottom wall and of each of the sidewalls and which forms an outer surface of the base; and

a lid configured to cover an open end of the rigid foam container opposite the bottom wall.

2. The container system of claim 1, wherein the film is disposed between the lid and an upper surface of each of the sidewalls when the lid closes the open end.

3. The container of claim 1, wherein the sidewalls, bottom wall and lid are composed of a rigid, thermally insulated material.

4. The container of claim 1, wherein the sidewalls, bottom wall and lid are composed of expanded polystyrene.

5. The container of claim 1, wherein the sidewalls are each tapered.

6. The container of claim 1, wherein the sidewalls are each perpendicular to the bottom wall.

7. The container of claim 1, wherein the outer surfaces of the sidewalls are contoured.

8. The container of claim 1, wherein the film is a liquid impermeable and moisture-resistant film.

9. The container of claim 8, wherein the film is a plastic shrink-wrap film.

10. The container of claim 1, wherein the film includes indicia at the outer surface of each of the sidewalls.

11. A rigid, thermally insulated container, comprising:

a base comprising:

a bottom wall including an outer surface;

a plurality of tapered sidewalls each including an outer surface and an inner surface; and

a film overlaying at least the outer surface of the bottom wall and of each of the sidewalls and forming an outer surface of the base; and

a lid configured to cover an open end of the base opposite the bottom wall.

12. The container of claim 11, wherein the film is a liquid-impermeable and moisture-resistant film.

13. The container of claim 11, wherein the film is disposed between the lid and an upper surface of each of the sidewalls when the lid closes the open end.

14. The container of claim 11, wherein the film overlays an upper surface of each of the sidewalls.

15. The container of claim 11, wherein the sidewalls, bottom wall and lid are composed of a rigid, thermally insulated material.

16. The container of claim 11, wherein the sidewalls, bottom wall and lid are composed of a rigid, foamed plastic material.

17. The container of claim 12, wherein the film is a plastic shrink-wrap film.

18. A rigid, thermally insulated container system, comprising:

a rigid styrofoam container having a bottom wall and a plurality of sidewalls integrally connected to the bottom wall;

a liquid-impermeable and moisture-resistant film overlaying an outer surface of the bottom wall and each of the sidewalls and providing an outer surface of the base; and

indicia on the film at the outer surface of at least one of the sidewalls; and

a lid configured to cover an open end of the base opposite the bottom wall.

19. A method of making a thermally insulated container, comprising:

providing a container comprising:

a bottom wall including an outer surface and an inner surface; and

a plurality of sidewalls each including an outer surface and an inner surface; and

applying a film on the container such that the film (i) overlays the outer surface of the bottom wall, (ii) overlays the outer surface and inner surface of each of the sidewalls, and (iii) forms an outer surface of the base.

20. The method of claim 19, wherein the film is a liquid impermeable and moisture-resistant film.

21. The method of claim 20, wherein the film is a plastic shrink-wrap film, and the applying comprises heating the film so as to shrink the film onto the container.

22. The method of claim 21, further comprising printing indicia on the film prior to heating the film.

23. The method of claim 19, wherein the sidewalls of the container are tapered.