The following chart depicts the relative performance difference of common insulated packaging materials.

The attachement clearly illustrates the difference between which materials merely protect a product from heat spikes, and the duration of those that can maintain a specified temperature range

The packages were of the same relative cubic size/volume.

Each package contained one bottle of 500 ml of water conditioned at 4 degrees C, wrapped in a thin layer of bubble wrap and probed with a thermocouple connected to a data logger.

Each package contained one identical 32 ounce (frozen) gel pack placed on top of the 500 ml bottle.

Once assembled, each package was exposed to a constant 30 degreesC (86 degrees F) for 48 hours.

For a detailed performance graph, click on the attachement icon below.

Container	Insulation	k factor	Wall Thickness	R Value	Hours < 10 C	Hours < 20 C
Corrugate			C Flute		2.5	17
Fabric tote	Thinsulate Microfiber	0.25	3/4"	3	8	23
Molded, Hard Sided	Rigid PUR "Igloo cooler"	0.14	1/2"	3.5	3	24
Bubble in corrugate	foil/bubble double layer	0.19	5/8"	3.3	6	27
EPS	Expanded Polystyrene	0.25	1.0"	4	10.4	25.9
EPS	Expanded Polystyrene	0.25	1.5"	6	11.3	28.1
EPS	Expanded Polystyrene	0.25	2.0"	8	12	30
PUR	Polyurethane	0.15	2.0"	13.3	26	48
Vacuum	Vacuum panel(Nanotherm)	0.029	1.0"	35	32	80.3
Vacuum	Vacuum panel with 1" EPS	0.04	2.0"	50	54	80