Expanded polystyrene is a plastic material that you may often hear referred to as Styrofoam.  While this is not entirely accurate (Styrofoam was actually a trademark of the Dow Chemical Company),  many of the products you think of when you hear Styrofoam are in fact made from expanded polystyrene, or EPS.  All of the coolers and insulated shippers available at Cooler Warehouse are made from this material.  The structure of EPS foam makes it the ideal material for a variety of manufacturing applications.  It is made up of thousands of tiny beads of low-density polystyrene, which makes it both durable and lightweight; a perfect combination for shipping!  Since the cells of the tiny beads are not interconnected, heat has a hard time travelling through expanded polystyrene, making it high-performance insulator.  This combination of qualities make EPS Foam, and K-Lock™ Molded Shipping Boxes in particular, an ideal cold-chain shipping solution.