Saran is the trade name of a thin plastic film used for keeping food fresh by sealing. The compound polyvinylidene chloride (PVDC) was discovered in 1933 by researchers from the Dow Chemical Company and registered in 1940.[1] It was acquired by S.C. Johnson & Son, Inc. in 1998 and the formulation changed to a less effective polyethylene (PE) in 2004 due to chlorine content.[2] As a food wrap, the principal advantages of polyvinylidene chloride, compared to other plastics, are its ability to adhere to itself and its very low permeability to water vapor, flavor and aroma molecules, and oxygen. This oxygen barrier prevents food spoilage, while the film barrier to flavor and aroma molecules helps food retain its flavor and aroma.[3]
History
Byproduct resin 1.1 dichloroethyl, a monomer of Polyvinylidene chloride (PVDC) was discovered at Dow Chemical Company (Michigan, United States) in 1933 when a lab worker, Ralph Wiley, was having trouble washing beakers used in his process of developing a dry-cleaning product,