Polyethylene Foam is produced through the polymerization of ethylene. It’s made up of huge chains of ethylene and has a molecular weight in the millions, meaning the material can be ripped apart by human hands. Polyethylene densities or material properties is created by using different catalysts during the polymerization process. It’s used in shoulder and back straps and in back panel of selected backpacks. Retains shape while resisting compression. It is a versatile, cost effective, lightweight material, which can be produced in varying densities to suit many applications.