Method of making a thermally insulated polyurethane shipper

Abstract

A method of making a thermally insulated sandwich polyurethane (PUR) shipper for a temperature sensitive payload is provided. The method comprises the steps of mounting an inner box upside down on a tool, adhering an insulating panel to the outer facing surfaces of the inner box, positioning an outer box around the inner box assembly, pouring liquid polyurethane into the gap between the outer box and inner box assembly, and foaming the liquid polyurethane. The PUR foam fills the space between the VIP panels and the outer box, and preferably covers the VIP panels.

Claims

1. A method of making a sandwich PUR shipper comprising the steps of: Step 100: Providing an inner box having a bottom and four sides; Step 102: Adhering an insulating panel to the outer facing surface of each of the inner box sides to create an inner box assembly, each insulating panel having a top edge that faces away from the inner box bottom; Step 104: Positioning an outer box on top of the inner box assembly so that the inner box and outer box are nested and so that there is a gap between the outer box and the inner box assembly; Step 108: Pouring liquid polyurethane into the gap; and Step 110: Foaming the liquid polyurethane to create PUR foam that covers the top edge of each insulating panel so that the insulating panels are completely enclosed by the inner box and the PUR foam.

2. The method of claim 1 wherein: Step 100 includes mounting the inner box upside down on a tool; and Step 104 includes using the tool to hold the outer box steady so that it does not contact the inner box assembly.

3. The method of claim 2 wherein, after Step 104 and before Step 108, the method comprises the further step of: Step 106: Inverting the tool 180 degrees so that the nested boxes are right side up.

4. The method of claim 2 wherein: each insulating panel is generally rectilinear in shape.

5. The method of claim 1 wherein: the PUR foam has an R-value; and the insulating panels have an R-value equal to or greater than the R-value of the PUR foam.

6. The method of claim 5 wherein: the insulating panels have an R-value greater than that of the PUR foam.

7. The method of claim 6 wherein: the insulating panels have an R-value about at least twice that of the PUR foam.

8. The method of claim 1 wherein: the insulating panels are VIP panels.

9. The method of claim 1 wherein: Step 102 includes wedging the insulating panels against each other so that a side edge of each insulating panel abuts an adjacent insulating panel.

10. A method of making a sandwich PUR shipper comprising the steps of: Step 100: Providing an inner box having a bottom and four sides; Step 102: Adhering an insulating panel to the outer facing surface of each of the inner box bottom and sides to create an inner box assembly, each insulating panel having a top edge that faces away from the inner box bottom; Step 104: Positioning an outer box on top of the inner box assembly so that the inner box and outer box are nested and so that there is a gap between the outer box and the insulating panels; Step 108: Pouring liquid polyurethane into the gap; and Step 110: Foaming the liquid polyurethane to create PUR foam that fills the entire gap between the outer box and the insulating panels and covers the top edge of each insulating panel.

11. The method of claim 10 wherein: Step 100 includes mounting the inner box upside down on a tool; and Step 104 includes using the tool to hold the outer box steady so that it does not contact the inner box assembly.

12. The method of claim 11 wherein, after Step 104 and before Step 108, the method comprises the further step of: Step 106: Inverting the tool 180 degrees so that the nested boxes are right side up.

13. The method of claim 10 wherein: the PUR foam has an R-value; and the insulating panels have an R-value equal to or greater than the R-value of the PUR foam.

14. The method of claim 13 wherein: the insulating panels have an R-value about at least twice the R-value of the PUR foam.

15. The method of claim 10 wherein: Step 102 includes wedging the insulating panels against each other so that a side edge of each insulating panel abuts an adjacent insulating panel.

16. The method of claim 10 wherein: Step 102 includes adhering a bottom insulating panel to the outer facing surface of the inner box bottom.

17. The method of claim 16 wherein: the insulating panels and the bottom insulating panel are VIP panels.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a thermally insulated sandwich PUR shipper according to the invention.

(2) FIG. 2 is a perspective view of an outer corrugated box used in making the thermally insulated sandwich PUR shipper of FIG. 1.

(3) FIG. 3 is a perspective view of an inner box used as a component of the sandwich PUR shipper 10 of FIG. 1.

(4) FIG. 4 is a perspective view of a VIP panel used as a component of the sandwich PUR shipper 10 of FIG. 1.

(5) FIG. 5 is a perspective view of part of a tool that may be used to make the thermally insulated sandwich PUR shipper of FIG. 1.

(6) FIG. 6 is a schematic diagram showing a method of making the thermally insulated sandwich PUR shipper of FIG. 1.

(7) FIG. 7 is a perspective view of an outer corrugated box mounted on top of an inner box assembly.

(8) FIG. 8 is a perspective view of an operator pouring liquid polyurethane into the air gap between the outer box and the inner box.

(9) FIG. 9 is a perspective view of an operator closing the tool and foaming the PUR.

(10) FIG. 10 is a top perspective view of a completed sandwich PUR shipper shown with some of the PUR foam removed for clarity.

(11) FIG. 11 is a graph comparing the thermal performance of a sandwich PUR shipper according to the disclosure to a PUR shipper for a summer ambient profile.

(12) FIG. 12 is a graph comparing the thermal performance of a sandwich PUR shipper according to the disclosure to a PUR shipper for a winter ambient profile.

DETAILED DESCRIPTION OF THE INVENTION

(13) While this invention may be embodied in many forms, there is shown in the drawings and will herein be described in detail one or more embodiments with the understanding that this disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to the illustrated embodiments. For instance, while the sandwich PUR shipper of the disclosure will now be described as comprising VIP panels, it should be understood that the insulating panels can be any suitable insulating panel.

(14) The term R-value as used herein refers to the resistance of a material to heat flow, and typically is expressed in units of hr-ft.sup.2- F./BTU-in, referring to the thermal resistance of a material that is a nominal one inch thick. Where units are not explicitly provided, the R-value should be understood to be in units of hr-ft.sup.2- F./BTU-in.

(15) The Thermally Insulated Sandwich PUR Shipper

(16) The invention is a thermally insulated sandwich polyurethane (PUR) shipper for shipping a temperature sensitive payload and a method of making the same.

(17) Turning to the drawings, FIG. 1 is a perspective view of a sandwich PUR shipper 10 according to one aspect of the invention. The sandwich PUR shipper 10 comprises an outer box 12, an inner box 14 nested within the outer box 12, insulating panels such as vacuum insulated panels (VIP panels) 16 adhered to the exterior sides and bottom (outer facing surfaces) of the inner box 12, and PUR foam 18 located between the VIP panels 16 and the outer box 18. The top 32 of the inner box 14 has been removed for clarity.

(18) The insulating panels may be VIP panels or any other suitable panel made of insulation material (instead of VIP), preferably with an insulation value (R-value) equal to or greater than the PUR foam. In some instances the R-value of the insulation panels may be about twice that of the PUR foam or even higher. For example, VIP panels may have an R-value of about 35 to 40, much higher than the typical R-value of 5 to 6 for PUR foam.

(19) FIG. 2 is a perspective view of an outer box 12 used as a component of the sandwich PUR shipper 10 of FIG. 1. Preferably the outer box 12 is made of corrugated material and comprises bottom flaps 22 that form the bottom 22 of the outer box 12, four side panels 24 extending from the periphery 23 of the bottom 22 to the top periphery 27, and a top 26 comprised of top flaps 26 foldably attached to the side panels 24 along the top periphery 27.

(20) FIG. 3 is a perspective view of an inner box 14 used as a component of the sandwich PUR shipper 10 of FIG. 1. Preferably the inner box 14 is made of corrugated material and comprises a bottom 28 having a bottom periphery 29, four side panels 30 extending from the periphery 29 of the bottom 28 to a top periphery 33, and a top 32 comprised of top flaps 32 foldably attached to the side panels 30 along a top periphery 33. The top flaps 32 may be folded together to close the inner box 14. The inner box 14 may be sealed with tape 37 or other suitable means.

(21) The inner box 14 is smaller than the outer box 12 so that the inner box 14 can nest within the outer box 12, leaving a gap therebetween for accommodating the VIP panels 16 and the PUR foam 18. The inner box 14 defines an interior space 20 (FIG. 1) for holding a payload.

(22) The VIP panels 16 may generally be composed of a rigid, highly-porous, nano-size material core made from fused silica, aerogel, or glass fiber, surrounded by a plastic film enclosure that is vacuum packed and nearly hermetically sealed so as to remove any remnant air particles within the enclosure. As shown in FIG. 4, each VIP panel 16 is generally rectilinear in shape, somewhat like a flattended brick, with two flat sides 35, three substantially flat side edges 34 and a substantially flat top edge 36. Each vacuum insulated panel 16 may be oriented substantially orthogonally to at least one adjacent vacuum insulated panel 16 and have one or more edges 34 that abut the adjacent vacuum insulated panels 16.

(23) Referring back to FIG. 1, the VIP panels 16 are located between the nested outer box 12 and inner box 14 and, more specifically, between the PUR foam 18 and the inner box 14, which protects the VIP panels 16 from punctures or tearing. Preferably the VIP panels 16 are wedged against each other together so that the side edge 34 of one VIP panel 16 abuts an adjacent VIP panel 16, thereby reducing or eliminating edge leaks. The PUR foam 18 may cover the top edges 36 of the VIP panels 16 to seal off the VIP panels 16 so they are completely enclosed as shown in FIG. 10.

(24) Method of Making the Sandwich PUR Shipper

(25) The sandwich PUR shipper may be made using a tool 40 such as that shown in FIG. 5. FIG. 6 is a schematic diagram showing a method of making the thermally insulated sandwich PUR shipper 10 of FIG. 1. The method may comprise the following steps:

(26) Step 100: Mounting an inner box 14 upside down on a tool 40.

(27) Step 102: Adhering an insulating panel 16 such as a VIP panel 16 to the exterior (outer box facing) side of each of the inner box bottom 28 and sides 30 using a sealant or other suitable means to create an inner box assembly 38 such as that shown in FIG. 5. There should be no VIP panel 16 adhered to the top 32 of the inner box 14.

(28) Step 104: Mounting an outer box 12 on top of the inner box assembly 38 as shown in FIG. 7 so that there is a gap 50 (space) between the outer box 12 and the VIP panels 16 or inner box assembly 38. The tool 40 should hold the outer box 12 steady so that it does not contact the inner box assembly 38. The inner box assembly 38 is obscured by the outer box 12 in FIG. 7 but may be seen partially in FIGS. 8 and 10.

(29) Step 106: Closing the bottom flaps 22 of the outer box 12 and inverting the tool 180 degrees so that the nested boxes 12, 14 are now right side up as shown in FIG. 8. The inner box assembly 38, including the inner box 14 and the VIP panels 16 adhered to the sides 30 of the inner box 14, can be seen in FIG. 8 nested within the outer box 12. The outer box 12 is shown with its top flaps 26 open. An operator O is shown in the right foreground.

(30) Step 108: Pouring liquid polyurethane into the air gap 50 between the outer box 12 and the VIP panels 16 as shown in FIG. 8. The PUR will settle around the bottom of the outer box 12. The volume of PUR may be about 10% of the volume of the air gap 50.

(31) Step 110: Closing the tool 40 and foaming the PUR for about 15-30 minutes as shown in FIG. 9. The PUR foam 18 should fill the entire gap 50 between the outer box 12 and the VIP panels 16.

(32) FIG. 10 is a top perspective view of a completed sandwich PUR shipper 10 shown with some of the PUR foam 18 removed for clarity. Preferably, the PUR foam 18 covers the VIP panels 16 to seal off the VIP panels 16 so they are completely enclosed as shown in FIG. 10.

(33) The resulting shipper 10 uses less PUR than conventional shippers and may have improved performance over some conventional PUR shippers.

(34) Case Studies

(35) The following case studies compare performance between a sandwich PUR shipper according to the disclosure and a standard PUR shipper under summer conditions and winter conditions.

(36) Case Study 1Summer Ambient Profile

(37) In case study 1, the performance of a sandwich PUR shipper was compared to the performance of a standard PUR shipper of identical size. The objective was to maintain the specification pay load (eg. vaccines) between 2-8 degrees C. for a period of 72 hours.

(38) FIG. 11 is a graph comparing the thermal performance of the sandwich PUR shipper according to the disclosure to the standard PUR shipper for a summer ambient profile. The sandwich PUR shipper passed the summer ambient profile test while standard PUR shipper failed after 36 hours.

(39) Case Study 2Winter Ambient Profile

(40) In case study 2, the performance of a sandwich PUR shipper was compared to the performance of a standard PUR shipper during a winter ambient profile. Again, the objective was to maintain the pay load between 2-8 degrees C. for a period of 72 hours.

(41) FIG. 12 is a graph comparing the thermal performance of the sandwich PUR shipper according to the disclosure to the PUR shipper for a winter ambient profile. The sandwich PUR shipper maintained product temperature within a narrow tolerance while the standard PUR shipper failed to maintain product within the specified temperature range.

(42) Both case studies 1 and 2 confirm that a sandwich PUR shipper according to the present disclosure can exceed the performance of a standard PUR shipper. The sandwich PUR shipper is capable of meeting a product temperature range specification (eg., 2-8 degrees C.) irrespective of summer or winter ambient profile.

(43) Case Study 3Reduction in Size and Weight

(44) The following table compares volume and size reduction achieved by constructing a sandwich PUR shipper according to the present disclosure.

(45) TABLE-US-00001 TABLE 1 Shipper Type Outer Dimensions, Inches Sandwich PUR Shipper 17.28 11.03 12.78 Standard PUR Shipper 20.05 14.25 16

(46) While keeping the insulation value of the overall shipper the same, a sandwich PUR shipper can achieve a 47% reduction in volume and up to a 20% reduction in weight.

INDUSTRIAL APPLICABILITY

(47) The thermally insulated sandwich PUR shipper may be used in any industry where temperature sensitive products are shipped, including but not limited to the pharmaceutical, hospital and food industries.

(48) It is understood that the embodiments of the invention described above are only particular examples which serve to illustrate the principles of the invention. Modifications and alternative embodiments of the invention are contemplated which do not depart from the scope of the invention as defined by the foregoing teachings and appended claims. It is intended that the claims cover all such modifications and alternative embodiments that fall within their scope.