INSULATING ASSEMBLIES AND CONTAINERS

Abstract

Insulating assemblies having improved thermal seals are provided. The insulating assemblies have an interface between a base portion and a lid that has an angled transitional portion and at least one elevation change. The angled transitional portion advantageously improves lid removability, assembly reusability, and resistance to thermal energy transfer.

Description

FIELD OF THE DISCLOSURE

This disclosure relates generally to foam insulation assemblies and to methods of producing foam insulated articles and, in particular, relates to insulating structures, such as containers, with a removable lid having an improved thermal seal and methods for producing such structures.

BACKGROUND

Insulated shippers are commonly used for shipping meal kits, confectionary products, cakes, other perishable goods, and medical items such as vaccines. These insulated shippers are chosen for their ability to prevent thermal energy transfer between the interior of the shipper and the environment.

Insulated shippers commonly include a box portion or base having a cavity for goods and a lid configured to seal the cavity from the environment. The base and lid are typically formed from the same material. The interface between the base and the lid is responsible for the greatest thermal energy transfer. As such, the quality of the interface between the base and the lid can be determinative of the overall quality of a particular insulated shipper. In other words, poor sealing of the lid onto the base may result in failure of the insulated shipper and spoliation of the goods inside.

Prior attempts to reduce thermal loss at the interface between the base and the lid of insulated shippers incorporated shaped edges on both the base and lid that interlock together, increasing the contact area and theoretically reducing thermal transfer. For example, zero-clearance lid-base designs, such as the one in FIG. 1, increase the contact area by an amount dictated by the overhang of the lid over the lip of the base. Variations such as the double-groove interlock improve on the zero-clearance design, such as the one in FIG. 2. Dovetail lid-base designs, such as the one in FIGS. 3A-3B, increase the contact area by incorporating a groove in the lid into which a ridge on the base may fit. However, these prior designs have exceptionally poor reusability due to compression creep, where the insulating structure experiences small changes in size and shape over time, and lid breakage when the lid is removed by a user, as depicted in FIG. 3B.

Accordingly, improved insulated shippers are needed for overcoming one or more of the technical challenges described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanying drawings. The use of the same reference numerals may indicate similar to identical items. Various embodiments may utilize elements and/or components other than those illustrated in the drawings, and some elements and/or components may not be present in various embodiments. Elements and/or components in the figures are not necessarily drawn to scale. Throughout this disclosure, depending on the context, singular and plural terminology may be used interchangeably.

FIG. 1 is a cross-sectional view of an existing lid-base interface known in the art.

FIG. 2 is a cross-sectional view of an existing lid-base interface known in the art.

FIG. 3A is a cross-sectional view of an existing lid-base interface known in the art.

FIG. 3B is a cross-sectional view of the lid-base interface in FIG. 3A after breakage.

FIG. 4 is a cross-sectional view of an exemplary lid-base interface in accordance with the present disclosure.

FIG. 5 is a cross-sectional view of an exemplary lid-base interface in accordance with the present disclosure.

FIG. 6 is a perspective view in cross-section of an exemplary insulating assembly in accordance with the present disclosure.

FIG. 7A is a cross-sectional view of an exemplary lid-base interface in accordance with the present disclosure.

FIG. 7B is a cross-sectional view of the lid-base interface in FIG. 7A during removal in accordance with the present disclosure.

FIG. 8 is a cross-sectional view of an exemplary lid-base interface in accordance with the present disclosure.

FIG. 9 is a cross-sectional view of an exemplary lid-base interface in accordance with the present disclosure.

FIG. 10 is a cross-sectional view of an exemplary lid-base interface in accordance with the present disclosure.

FIG. 11 is an illustration of exemplary lid-base transition angle profiles in accordance with the present disclosure.

FIG. 12 is an illustration of an exemplary lid-base interface in accordance with the present disclosure.

FIG. 13 is a cross-sectional view of an exemplary extension ring in accordance with the present disclosure.

FIG. 14 is a perspective view in cross-section of an exemplary insulating assembly with an extension ring in accordance with the present disclosure.

FIG. 15 is a graph of test results for the ISTA 7D 48-hour winter profile for a number of insulating assemblies.

DETAILED DESCRIPTION

Insulating assemblies and methods for producing insulating assemblies are provided herein including assemblies with improved interfaces between the base portion and the lid of the insulating assembly. In particular, it has been discovered that shaping the interface between the base portion and the lid with a protrusion having an angled transitional section can result in improved thermal properties, improved structural integrity, improved lid removability, and improved structure reusability. Furthermore, in a preferred embodiment, shaping the interface between the base portion and the lid to approximate a non-right trapezoid (i.e., a scalene or isosceles trapezoid), or a segment thereof, has been demonstrated to improve the effectiveness of the assembly.

Throughout this disclosure, various aspects are presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

As used herein, the term “about” with reference to dimensions refers to the dimension plus or minus 10%.

Insulating Assemblies

Insulating assemblies are disclosed herein. In some embodiments, the assembly includes a base portion having a first interface extending along a rim thereof, and a lid having a second interface extending along a rim thereof. The first interface and the second interface may be configured to interlock together to form a closed insulated container, i.e., to define an interior volume bounded by the base portion and lid.

As used herein, an “interface” refers to the area on the base portion or the lid that forms the point of contact between the base portion and the lid. The interfaces are typically shaped or molded so that the base portion and lid interlock together to form a closed insulated container, thereby reducing thermal energy transfer across the interfaces.

As used herein, “interlock,” “interlock together,” and similar phrases refer to the contacting of two components having interfaces that are shaped and/or designed to be joined together and form a closed insulated container. In other words, the interfaces have complementary shapes, sometimes referred to in mechanical industries as a “male” component/interface joining with a “female” component/interface. Thus, the mere contacting of a component with another component does not result in an interlock unless the point of contact includes the joining of two complementary surfaces or structures.

In some embodiments, each of the first and second interfaces have at least one elevation change, such that the interlock is formed by mating corresponding elevations changes of the first and second interfaces.

As used herein, an “elevation change” refers to a segment of a protrusion or channel molded or shaped to form at least a portion of the first and second interfaces. For example, an “L”-shaped lip on the interfaces, when viewed in cross-section, includes an initial flat surface and an “elevation change” to a second flat surface higher or lower than the initial flat surface. Alternatively, a trapezoidal-shaped protrusion or channel includes an initial flat surface, a first elevation change, a second flat surface that is higher or lower than the initial flat surface, a second elevation change, and a final flat surface that is normally level with the initial flat surface.

As used herein, the “transitional section” refers to the surface representing the elevation change. For example, an “L”-shaped lip on the interfaces includes an initial flat surface, a transitional section, and a second flat surface higher or lower than the initial flat surface. A triangular-shaped lip on the interfaces includes a first transitional section increasing or decreasing the elevation, followed by a second transitional section decreasing or increasing the elevation.

In some embodiments, each of the elevation changes comprises a sloped transitional section relative to the vertical. As used herein, an angle or slope “relative to the vertical” refers to an angle or slope measured with 0° representing a perpendicular plane relative to the horizon, and 90° representing a plane parallel to the horizon, measured when the assembly is positioned such that the lid is parallel relative to the horizon. Furthermore, as used herein, an angle measured “relative to the vertical” has a positive angle regardless of whether such angle is measured clockwise or counter-clockwise.

In some embodiments, the sloped transitional section of each elevation change has a slope of between about 2° to about 43°, relative to the vertical. For example, the sloped transitional section of each elevation change may be between about 5° and 20°, relative to the vertical. In some embodiments, the sloped transitional section of each elevation change has a slope of 5° relative to the vertical.

In some embodiments, the base portion is in the form of a container having an open end for receiving the lid.

In some embodiments, the base portion and lid are formed from fused expandable foam beads, and the transitional section includes a transition slope of 20/1 foam beads or less. In other words, the slope of the transition from an initial flat section to the transitional section constitutes a “rise,” or elevation change, of less than 20 foam beads over a “run,” or horizontal change, of greater than 1 foam beads. For example, a slope of 10 involves an elevation change of 10 beads over a horizontal change of one foam bead, and a slope of 5 involves an elevation change of 10 beads over a horizontal change of 2 foam beads. When a fused, expanded foam bead has a diameter of approximately 2 mm, the transition section has a slope of less than 20 foam beads per an elevation change of 20 mm. However, bead size varies depending on the material used (expandable polystyrene, polylactic acid, or another material), the molding process, and the density of the molded foam. Furthermore, the quality and structural integrity of an insulating structure formed from fused, expanded foam beads depends on the fusing of the beads themselves. Accordingly, the acceptable transition slope is not determined by a particular length in millimeters, but is instead determined by a length as measured in fused, expanded foam beads.

In some embodiments, the base portion and the lid of the assembly are formed from fused expandable foam beads made from polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), rubberized expandable polystyrene (EPS), or other modified EPS. It has been discovered that materials suitable for foaming and molding into insulating assemblies that have a resiliency of at least 80% after 24 hours of compression particularly benefit from the interface geometries described herein. Insulating assemblies formed from foam materials having a resiliency of 90% or greater have benefitted from the interfaces described herein, and insulating structures formed from foam materials having a resiliency of 95% or greater have demonstrated even greater improvements. For example, PLA-based foam typically have a resiliency of between 90% and 97% and insulating assemblies formed from PLA-based foam have been shown to benefit significantly from the incorporation of interfaces as described herein.

In some embodiments, the base portion and the lid are formed from a material having an R-value of at least 3.8 at 23° C. As used herein, the “R-value” is an insulating material's resistance to conductive heat flow and is calculated using Equation 1:

$\begin{array}{cc}R=\frac{❘\Delta T❘}{{\varphi }_q}& \mathrm{Equation}1\end{array}$

where R is the R-value in ° F.·ft²/BTU·in, ΔT is the temperature difference across a barrier in ° F. (such as the wall of closed insulated container), and ϕ_q is the heat flux through the barrier in BTU/(h·ft²). Commercial equipment may be used to measure the R-value of a particular barrier, such as a Fox Heat Flow Meter from TA Instruments, New Castle, Del., USA. The R-value of a particular foam insulating assembly is affected by the material used to form the foam beads, the density of the foam insulating assembly, the thickness of the walls of the insulating assembly, and, of particular note to the present disclosure, the quality of the seal between the lid and the base section. In some embodiments, the R-value at 23° C. is between about 3° F.·ft²/BTU·in° F.·ft²/BTU·in to about 5° F.·ft²/BTU·in. For example, the R-value may be 3° F.·ft²/BTU·in, 3.5° F.·ft²/BTU·in, 4° F.·ft²/BTU·in, 4.5° F.·ft²/BTU·in, 5° F.·ft²/BTU·in, or any R-value therebetween. In some embodiments, the R-value at 50° C. is between about 2.5° F.·ft²/BTU·in° F.·ft²/BTU·in and 4.5° F.·ft²/BTU·in. For example, the R-value may be 2.5° F.·ft²/BTU·in, 3° F.·ft²/BTU·in, 3.5° F.·ft²/BTU·in, 4° F.·ft²/BTU·in, 4.5° F.·ft²/BTU·in, or any R-value therebetween. In some embodiments, the R-value at −10° C. is between 3.5° F.·ft²/BTU·in° F.·ft²/BTU·in and 5.5° F.·ft²/BTU·in. For example, the R-value may be 3.5° F.·ft²/BTU·in, 4° F.·ft²/BTU·in, 4.5° F.·ft²/BTU·in, 5° F.·ft²/BTU·in, 5.5° F.·ft²/BTU·in, or any R-value therebetween.

In some embodiments, the closed insulated container passes the International Safe Transit Association (ISTA) 7D 48-hour summer profile test and the ISTA 7D 48-hour winter profile test at an overall weight at least 20% lower than a conventional EPS assembly. The ISTA 7D test procedure evaluates the effect of external temperature on a particular insulated container. Theoretically, an insulated container can be filled with more, or with colder, thermal sinks so as to lower the overall temperature of the insulated container. In this way, an otherwise-poor insulated container can pass the ISTA 7D 48-hour profile tests, but a greater number of thermal sinks or ice packs are required to do so. Therefore, one measure of an improved insulated container that passes the ISTA 7D 48-hour profile tests is the weight of the container, i.e., a container that can pass the ISTA 7D 48-hour profile tests that has a reduced weight compared to conventional containers must have improved thermal energy capabilities. The ISTA certifies thermal chambers for performing and evaluating the results of the 7D test procedures.

In some embodiments, when the lid is interlocked with the base portion, the lid withstands at least 8 pounds of force without being removed after at least 10 lid remove-and-replace cycles. In other words, the insulated container is loaded with at least 8 pounds of contents, inverted so that the downward force is applied directly to the lid of the insulated container, and allowed to rest for 10 seconds (i.e., a “remove-and-replace cycle”). The size and shape of the lid and base portion influence the ability for the insulated container to maintain its strength over a greater number of remove-and-replace cycles. In some embodiments, when the lid is interlocked with the base portion, a removal force necessary for removing the lid changes by less than 10% over 24 hours. In some tests, the insulated container is inverted and allowed to rest for 24 hours. Upon returning to normal orientation, the lid is removed and replaced, and the inversion process is repeated. Upon lid failure while inverted, one pound of contents is removed and the process continued. This test measures the effect of “compression creep,” which is a phenomenon common to foam insulated containers that occurs over time as an insulating container's lid is removed and replaced several times. The fused, expanded foam beads that form the insulated container experience small changes in size and shape over time, particularly when compressed by, for example, interlocking the lid with the base portion. As a result, the lid of a typical insulated container loses integrity over time and fails to remain securely coupled to the base portion. It has been unexpectedly discovered that shaping the interface between the lid and base portion as described herein reduces or eliminates the effect of compression creep.

In some embodiments, the first interface of the base portion has two elevation changes so that the first interface of the base portion forms a protrusion, and the second interface of the lid has two elevation changes complementing the first interface so that the second interface forms a channel into which the protrusion of the first interface is inserted. In other embodiments, the first interface forms a channel while the second interface forms a protrusion. In some embodiments, the protrusion and channel resemble a non-right trapezoid. In other embodiments, the protrusion and channel resemble a semi-circle, half-oval, triangle, or another shape that has a sloped transitional portion and at least two elevation changes. For example, an interface resembling a semi-circle can be considered as having a first sloped transitional portion consisting of a quarter-circle that increases or decreases the elevation by a first amount, and a second sloped transitional portion consisting of a quarter-circle that decreases or increases the elevation by a second amount that may be equal to the first amount.

In some embodiments, the lid is selectively removable from an interlocked configuration with the base portion by a user without deforming the lid or base portion. Prior interlocking lids attempt to achieve improved thermal properties by increasing the contact area between the base portion and lid, but this is normally at the cost of an easily removable lid. It has been unexpectedly discovered that when forming the interfaces as described herein, deliberate application of force to remove the lid easily removes the lid without breakage by providing an airflow path into and out of the insulating structure as the lid is being removed. However, such ease of removal does not come at the cost of resistance to lid removal by the contents.

In some embodiments, the assembly includes an extension ring configured to increase the volume of the closed insulated container. The extension ring may have a first extension interface extending along a lower rim thereof, and a second extension interface extending along an upper rim thereof. The first extension interface may be configured to contact and interlock with the first interface of the base portion by mating at least one elevation change on the first extension interface with the corresponding elevation change of the first interface. The second extension interface may be configured to contact and interlock with the second interface of the lid by mating at least one elevation change on the second extension interface with the corresponding elevation change of the second interface. The extension ring may therefore be used to increase the interior volume of the closed insulated container by first being affixed to the base portion prior to affixing the lid. An extension ring may be desirable when the contents of the closed insulated container require maintaining a lower temperature for a longer period of time, which is typically achieved by the incorporation of more thermal sinks, such as ice packs. Increasing the volume of the closed insulated container through the addition of an extension ring therefore permits the inclusion of more ice packs without reducing the quantity of goods. Furthermore, the ability to modularly change the internal volume of the assemblies reduces manufacturing and storage costs by requiring only the production of a single base portion with a modular volume, instead of configurations of base portions. Further still, manufacturers can utilize weather forecasts for a particular shipment's destination and/or itinerary, with or without the aid of automated software, to evaluate the degree of cooling necessary for a particular shipment and dynamically determine whether an extension ring should be included to accommodate the necessary cooling packs.

In some embodiments, the assembly may be used as a shipper without the addition of any other structural component. In other embodiments, the insulating structure may be inserted into and supported by a layer of corrugation, such as corrugated cardboard. In some embodiments, the insulating structure may be surrounded and supported by a layer of shrink wrap. In some embodiments, the insulating structure may be surrounded and supported by a layer of craft paper.

In another aspect, an insulating assembly may include a base portion having a first interface extending along a rim thereof and a lid having a second interface extending along a rim thereof. The first interface may be configured to interlock with the second interface to form a closed insulated container, and each of the first and second interfaces comprise a single elevation change such that the interlock is formed by mating corresponding elevation changes of the first and second interfaces. Each elevation change may comprise a sloped transitional section relative to the vertical.

In some embodiments, when the lid is interlocked with the base portion, an upward-facing surface of the lid and an upward-facing surface of the base portion align with one another to form an upward-facing surface of the closed insulated container. As used herein, surfaces “align” when, when the surfaces are positioned proximal to each other, they form a new, flat surface. In this way, the lid may form a “plug-style” lid.

In some embodiments, the corresponding elevation changes of the base portion and the lid form a half-trapezoid. Thus, at least a portion of the lid may be configured to be disposed within the base portion. In some embodiments, the rim of the lid has a width greater than the rim of the base portion so that the lid is a “cap-style” lid.

FIG. 1 is an example of an existing lid-base interface known in the art, commonly referred to as a “zero-clearance” interface 100. When lid 102 is removed from base 104 by a user, the 90° angles that form the transition angles between the flat portions 106, 108 to transitional section 110 prevent ingress or egress of air, thereby creating a suction force. A heightened degree of force is required by a user, which often results in lid failure.

FIG. 2 is an example of an existing lid-base interface known in the art, commonly referred to as a double-groove interface 200. FIG. 3A is an example of an existing lid-base interface known in the art, commonly referred to as a dovetail interface 300. Interfaces 200 and 300 suffer from the same deficiencies as the one depicted in FIG. 1, namely, the creation of a suction force as the lid is removed by a user, often resulting in breakage as depicted in FIG. 3B.

FIG. 4 is a cross-sectional view of an exemplary lid base interface 400 in accordance with the foregoing disclosure. Lid 402 includes non-right trapezoidal channel 404, and base 406 includes a corresponding non-right trapezoidal protrusion 408. Trapezoidal channel 404 and trapezoidal protrusion 406 are formed by a first flat portion 410, first transitional section 412, second flat portion 414, second transitional section 416, and third flat portion 418. Second flat portion 414 is at a different elevation than first flat portion 410 and third flat portion 418, such that the channel 404 and protrusion 406 each have two elevation changes.

First transitional section 412 and second transitional section 416 are sloped and have an angle between about 2° to about 43° relative to the vertical, such as between about 5° to about 20° relative to the vertical. The angle may be 5° relative to the vertical. The slope of the transition from the first flat portion 410 to the first transitional section 412 is 20/1 foam beads or less, as discussed with respect to FIG. 11. The third flat portion may be level with the first flat portion, or the third flat portion may be higher or lower than the first flat portion depending on the desired geometry of the lid-base interface. The protrusion and channel may be non-right trapezoidal, or they may have another shape, such as a semi-circle, semi-oval, triangle, or another suitable shape, provided the transitional section has an angle, such as between about 2° to about 43° relative to the vertical. The depiction of the protrusion and channel as having a non-right trapezoidal shape, to the exclusion of other suitable shapes, is only in the interest of brevity and is not intended to limit the scope of the disclosure.

FIG. 5 is a cross-sectional view of an exemplary lid-base interface 500. Lid 502 includes non-right trapezoidal protrusion 504, and base 506 includes non-right trapezoidal channel 508. Trapezoidal protrusion 504 and trapezoidal channel 506 are formed by a first flat portion 510, first transitional section 512, second flat portion 514, second transitional section 516, and third flat portion 518. Second flat portion 514 is at a different elevation than first flat portion 510 and third flat portion 518, such that the channel 504 and protrusion 506 each have two elevation changes. First transitional section 512 and second transitional section 516 are sloped and have an angle between about 2° to about 43° relative to the vertical. The slope of the transition from the first flat portion 510 to the first transitional section 512 is 20/1 foam beads or less, as discussed with respect to FIG. 11.

Insulating assemblies may have a single lid-base interface geometry across the entire lid-base interface in a particular assembly, i.e., a single interface geometry extending around the entire rim of the lid and corresponding base, such that the cross-section of the interface is similar at any point around the rim of the assembly. Alternatively, assemblies may have a certain lid-base interface geometry along one wall of the assembly, such as the geometry depicted in FIG. 4, and a different lid-base interface geometry along another wall of the assembly, such as the geometry depicted in FIG. 5. In this way, the lid of a particular insulating assembly may have only limited viable orientations when interlocking with the corresponding base portion.

FIG. 6 is a perspective view in cross-section of an interlocked insulating assembly 600, comprising closed insulated container 602 having a lid 604 and a base 606, enclosing internal volume 608. The interface 610 between the lid 602 and base 604 is depicted as resembling that depicted in FIG. 4, but with rounded corners. As described previously, the interface between the lid and base could have a protrusion on the base, or a protrusion on the lid. The lid-base interface geometry may be consistent around the entire perimeter of the insulating assembly, or it may vary.

FIGS. 7A and 7B depict a lid-base interface 700 before and during removal of the lid 702 from the base 706. In FIGS. 7A and 7B, the lid 702 is depicted as having a non-right trapezoidal channel 704, and the base is depicted as having a non-right trapezoidal protrusion 708. The interface between lid 702 and base 706 is depicted as a non-right trapezoid with rounded corners rather than sharp corners, as described with reference to FIG. 11. As the lid 702 is lifted by a user, air is permitted to enter and/or exit, as shown by the arrows in FIG. 7B. This air ingress and egress is immediately possible upon loosening of the lid due to the shape of the protrusion, namely, the angle of the transitional section being between about 2° to 43° relative to the vertical. As a result, the lid is easily removable without breakage when deliberate force is applied, but a full, robust thermal seal is maintained until deliberate force is applied.

FIGS. 8-10 depict exemplary lid-base interfaces that may be used instead of the trapezoidal interface described previously. In FIGS. 8-10, a “half-trapezoid” shape is utilized so that the protrusion constitutes a single elevation change and one or two adjacent flat surfaces. FIG. 8 depicts a lid 802 in which at least a portion 804 of the lid 802 is disposed within the base portion 806. FIG. 9 depicts a “cap-style” lid 902 in which the sloped transitional section 904 of lid 902 is configured to surround the sloped transitional section 906 of the first interface of the base portion 908. FIG. 10 depicts a “plug-style” lid 1002, where an upper surface 1006 of the lid 1002 is aligned with an upper surface 1008 of the base portion 1004. In each of FIG. 8-10, the transitional section is sloped and has an angle between about 2° to 43° relative to the vertical and the resulting insulating structure realizes the benefits described herein.

FIG. 11 is a graph showing exemplary lid-base interface slopes that have been found to achieve the improved thermal sealing at the lid-base interface discussed herein. It has been unexpectedly discovered that shaping the slope of the lid-base interface to 20 foam beads or less (i.e. an elevation change of 20 beads or less over a horizontal change of 1 bead or more), the benefits described herein may be realized. FIG. 11 depicts a number of exemplary slopes that are 20 foam beads or less, demonstrating the wide variation in shapes that may be utilized in the insulating structures described herein. In some embodiments, the lid-base interface may have a sharp corner. In other embodiments, the lid-base interface may have a curved or rounded corner. In other embodiments,

FIG. 12 depicts an exemplary lid-base interface, illustrating the transitional angles α and β. α and β are each between about 2° and 43°. As described previously, α and β are described as positive angles, regardless of whether the angles are measured clockwise or counter-clockwise. α and β are depicted in FIG. 12 as being equal to one another, but α and β may differ. For example, α may be 4° and β may be 20°.

FIG. 13 is a cross-sectional view of an extension ring 1302 inserted between a lid 1304 and a base 1306 of an insulating assembly. Extension ring 1302 is configured to increase the volume of a closed insulated container. Extension ring 1302 and lid 1304 forms a first interface 1308, and extension ring 1302 and base 1306 forms a second interface 1310. Each of the first interface 1308 and second interface 1310 may have a lid-base interface geometry as described herein. The first interface and second interface may have identical geometry, as depicted in FIG. 13, which may increase the modularity of the extension ring and accompanying lid and base. In other words, the lid 1304 may be placed directly on base 1306 because the interface geometries are identical. The first interface and second interface may have different geometry depending on the intended use of the insulating structure.

FIG. 14 is a perspective view in cross section of an insulating assembly 1400 having an extension ring 1402 between a lid 1404 and base 1406.

EXAMPLES

The disclosure may be further understood with reference to the following non-limiting examples.

Example 1: ISTA Study to Evaluate Thermal Performance

Three sample insulating assemblies were tested to determine the effect of lid-base interface geometry on the thermal performance of the insulating structure. The first sample was an EPS box having a density of 2.0 pcf and a double-groove interface. The second sample was an EPS box having a density of 1.2 pcf and the non-right trapezoidal interface of the present disclosure. The third sample was a PLA box having a density of 1.2 pcf and the non-right trapezoidal interface of the present disclosure. An International Safe Transit Association (ISTA) study was completed on these structures. All dimensions for the insulating structures were identical besides the density and interface geometry. Each insulating structure was filled with the same refrigerants and a 100 mL water-filled bottle to simulate the temperature-sensitive payload. Testing was conducted on two structures of each type following the ISTA 7D 48-hour summer profile and the ISTA 7D 48-hour winter profile. The results of the test are presented in FIG. 15.

As shown in FIG. 15, all insulating structures passed the study. Furthermore, as demonstrated in Table A, the R-values were similar despite a weight reduction of 40%. The R-value of the insulating structure may be measured by a specific tool, such as a Fox Heat Flow Meter, available commercially from TA Instruments, New Castle, Del., USA.

TABLE A
Thermal Performance vs. Interface Geometry
	R-Value (° F. · ft2/BTU · in)
	50° C.	23° C.	−10° C.
EPS, 2.0 pcf, double-groove interface	3.917	4.24	4.50
EPS, 1.2 pcf, interface interface	3.538	3.87	4.29
PLA, 1.2 pcf, inventive interface	3.529	3.88	4.32

Example 2: Inverted Force Test to Evaluate Interface Strength

As described above, molded foam insulating structures experience “compression creep” over repeated lid removal and replacements, resulting in poor thermal sealing and poor reusability over time. Even without repeated lid removal cycles, these insulating structures may experience compression creep over time while the lid is installed so that a gap forms between the lid and base.

An experiment was performed between two samples. One sample was an EPS box having the non-right trapezoidal interface described throughout this disclosure. One sample was a PLA box having the non-right trapezoidal interface described throughout this disclosure. Each box was filled with 8 pounds of gel packs and inverted for 10 seconds. If the lid failed, the one pound of contents would be removed and the test performed again. If the lid withstood the force of the contents, the box would be restored upright, the lid removed and replaced, and the test repeated. The results of the test are presented below in Table B.

TABLE B
Results of Inverted Force Test
	Test Weight (lbs)
	Cycle
Sample	1	2	3	4	5	6	7	8	9	10
EPS Box 1	8	2	2	1	1	1	0	0	0	0
EPS Box 2	8	2	1	1	1	1	0	0	0	0
PLA Box 1	8	8	8	8	8	8	8	8	8	8
PLA Box 2	8	8	8	8	8	8	8	8	8	8

As shown in Table B, the PLA box with the non-right trapezoidal interface between the base and lid withstood at least 10 cycles of inversion and lid removal without failing. The EPS box failed on the first cycle, and the lid would not remain sealed until only 2 pounds of contents remained. No EPS box had a suitable seal after 6 cycles, demonstrating the importance of utilizing high-resiliency materials. The inability for EPS based containers to withstand inadvertent removal forces has motivated the adoption of the double-groove or “L” shaped interfaces. These interfaces deliberately increase the force necessary to remove the lid from an EPS container.

Example 3: Comparison of Inventive Interface with Double-Groove

Two insulated assemblies were constructed out of PLA bead foam, each with a density of 1.2 pcf. One sample had a trapezoidal interface as described herein. The other sample had a double-groove interface common in the industry. Each assembly was filled with identical contents and subjected to the ISTA 7D summer profile. The results of the test are presented in FIG. 16.

The insulated assembly with the inventive trapezoidal interface maintained a temperature below 19.5° C. (the critical temperature in the ISTA 7D summer profile) for 53.6 hours. In contrast, the insulated assembly with the double-groove interface maintained a temperature below 19.5° C. for only 47 hours. Indeed, as shown in FIG. 16, the insulated assembly with the inventive trapezoidal interface maintained a lower temperature than the assembly with the double-groove interface at every point throughout the test, keeping contents up to 6° C. cooler even after around 30 hours. Thus, by changing only the interface of the insulated assembly to the inventive trapezoidal interface, the temperature of the contents of the insulated assembly can be maintained below 19.5° C. for 14% longer than the double-groove interface.

While the disclosure has been described with reference to a number of embodiments, it will be understood by those skilled in the art that the disclosure is not limited to such embodiments. Rather, the disclosure can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not described herein, but which are commensurate with the spirt and scope of the disclosure. Conditional language used herein, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, generally is intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements or functional capabilities. Additionally, while various embodiments of the disclosure have been described, it is to be understood that aspects of the disclosure may include only some of the described embodiments. Accordingly, the disclosure it not to be seen as limited by the foregoing described, but is only limited by the scope of the appended claims.

Claims

1. An insulating assembly comprising: a base portion having a first interface extending along a rim thereof; anda lid having a second interface extending along a rim thereof,wherein the first interface is configured to interlock with the second interface to form a closed insulated container, andwherein each of the first and second interfaces comprise at least one elevation change, such that the interlock is formed by mating corresponding elevation changes of the first and second interfaces,wherein each of the elevation changes comprises a sloped transitional section relative to the vertical.

2. The assembly of claim 1, wherein the sloped transitional section of each elevation change has a slope of between about 2° to about 43°, relative to the vertical.

3. The assembly of claim 1, wherein the sloped transitional section of each elevation change has a slope of 5°, relative to the vertical.

4. The assembly of claim 1, wherein the base portion is in the form of a container having an open end for receiving the lid.

5. The assembly of claim 1, wherein: the base portion and lid are formed from fused expandable foam beads, andthe transitional section comprises a transition slope of less than 20/1 foam beads.

6. The assembly of claim 1, wherein the base portion and the lid are formed from fused expandable foam beads comprising at least one of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), rubberized EPS, and other modified EPS.

7. The assembly of claim 1, wherein the base portion and the lid are formed from a material having an R-value of at least 3.8° F.·ft2/BTU·in at 23° C.

8. The assembly of claim 1, wherein the closed insulated container passes the ISTA 7D 48-hour summer profile and ISTA 7D 48-hour winter profile tests at an overall weight at least 20% lower than a conventional EPS assembly.

9. The assembly of claim 1, wherein the assembly can be reused at least twice as many times as a conventional EPS assembly.

10. The assembly of claim 1, wherein when the lid is interlocked with the base portion, a removal force necessary for removing the lid changes by less than 10% over 24 hours.

11. The assembly of claim 1, wherein the first interface comprises a protrusion having two elevation changes, and wherein the second interface comprises a channel having two elevation changes.

12. The assembly of claim 1, wherein the first interface comprises a channel having two elevation changes, and wherein the second interface comprises a protrusion having two elevation changes.

13. The assembly of claim 1, wherein the lid is selectively removable from an interlock with the base portion, without deforming the lid or base portion.

14. The assembly of claim 1, further comprising an extension ring configured to increase the volume of the closed insulated container, the extension ring having a first extension interface extending along a lower rim thereof and a second extension interface extending along an upper rim thereof, wherein the first extension interface is configured to contact and interlock with the first interface by mating at least one elevation change on the first extension interface with the corresponding elevation change of the first interface, andwherein the second extension interface is configured to contact and interlock with the second interface by mating at least one elevation change on the second extension interface with the corresponding elevation change of the second interface.

15. The assembly of claim 1, further comprising a corrugated cardboard box into which the closed insulated container is inserted and secured.

16. The assembly of claim 1, further comprising a layer of shrink wrap disposed on an outer surface of the closed insulated container.

17. The assembly of claim 1, further comprising a layer of craft paper disposed on an outer surface of the closed insulated container.

18. An insulating assembly comprising: a base portion having a first interface extending along a rim thereof; anda lid having a second interface extending along a rim thereof,wherein the first interface is configured to interlock with the second interface to form a closed insulated container, andwherein each of the first and second interfaces comprise a single elevation change, such that the interlock is formed by mating corresponding elevation changes of the first and second interfaces,wherein each of the elevation changes comprises a sloped transitional section relative to the vertical.

19. The assembly of claim 18, wherein when the lid is interlocked with the base portion, an upper surface of the lid and an upper surface of the base portion align with one another to form an upper surface of the closed insulated container such that the lid is a plug-style lid.

20. The assembly of claim 18, wherein the sloped transitional section of the second interface of the lid is configured to surround the sloped transitional section of the first interface of the base portion, opposite an interior volume defined by the closed insulated container, so that the lid is a cap-style lid.