Method of making a thermally insulated polyurethane shipper

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.