Cold Chain Grocery Insulated Bag with Waterproof Inner Membrane and Gel-Pack Compatible Pocket for Last-Mile Fresh Food Delivery

The thermal architecture is the standard four-layer build for this class of bag, assembled from the outside in: a printed outer layer carrying the brand artwork, a closed-cell EPE foam core, an aluminium-foil reflective barrier, and a food-contact inner liner. The aluminium foil does the radiant work, reflecting the heat load back off the contents instead of letting it conduct inward. Because bare foil cannot be heat-sealed, it is supplied as an Al/PE laminate and the PE side is what welds to the inner liner. Behind the foil the EPE core blocks conduction and convection, and 8mm is the mainstream gauge for retail and delivery insulated bags, with 3mm, 5mm and 10mm the other common thicknesses.

Performance is quoted as a system figure rather than a single-layer number: closed-cell PE foams sit at roughly R 3.6 to 4.2 per inch, and a foil-lined foam build reaches an effective R 5 to 10 once the reflective layer and the trapped air gap are counted. A comparable construction of 600D outer, 8mm PE foam and aluminium-foil lining is quoted by the trade at about 8 to 10 hours of cold retention at 25 to 30 C ambient. The wide mouth opens fully for mechanical packing lines, the reinforced bottom carries 15kg without sagging, and the size ladder runs from 6L to 25L to cover single-basket and multi-basket grocery orders.