General view of the extrusion of saran bubbles from rolling machines at the Dow Chemical Company plant in Midland, Michigan. During production, molten saran polymer was extruded from circular dies, then cooled and transformed into large bubbles to give the film its required strength and proper thickness. The film subsequently passed through a series of rollers, which deflated the bubbles and prepared the film for winding on rolls. Initially developed for the U.S. Army to wrap arms and equipment for transport during World War II, saran plastic was subsequently developed and marketed as Saran Wrap for household use.