The Inventor of Saran Wrap

Saran resins and films often called polyvinylidene chloride or PVDC, have been used to wrap products for more than 50 years.

Saran works by polymerizing vinylidene chloride with monomers such as acrylic esters and unsaturated carboxyl groups to form long chains of vinylidene chloride. The copolymerization results in a film with molecules bound so tightly together that very little gas or water can get through. The result is an effective barrier against oxygen, moisture, chemicals, and heat that protects food, consumer products, and industrial products. PVDC is resistant to oxygen, water, acids, bases, and solvents. Similar brands of plastic wrap, such as Glad and Reynolds, do not contain PVDC.

Saran might be the first plastic wrap designed specifically for food products, but cellophane was the first material used to wrap just about everything else. A Swiss chemist, Jacques Brandenberger, first conceived of cellophane in 1911. It didn’t do much to preserve and protect food, however.

The Discovery of Saran Wrap

Dow Chemical lab worker Ralph Wiley accidentally discovered polyvinylidene chloride in 1933. Wiley was a college student who at the time cleaned glassware in a Dow Chemical lab when he came across a vial he couldn't scrub clean. He called the substance coating the vial "eonite," naming it after an indestructible material in the "Little Orphan Annie" comic strip. 

Dow researchers remade Ralph's "eonite" into a greasy, dark green film and renamed it "Saran." The military sprayed it on fighter planes to guard against salty sea spray and carmakers used it on upholstery. Dow later got rid of Saran's green color and unpleasant odor.

Saran resins can be used for molding and they melt adhesive bonding in non-food contact. In combination with polyolefins, polystyrene, and other polymers, Saran can be coextruded into multilayer sheets, films, and tubes.

From Planes and Cars to Food

Saran Wrap was approved for food packaging after World War II and was prior-sanctioned by the Society of the Plastics Industry in 1956. PVDC is cleared for use as a food contact surface as a base polymer in food package gaskets, in direct contact with dry foods and for paperboard coating in contact with fatty and aqueous foods. It’s capable of capturing and containing aromas and vapors. When you place a Saran-wrapped peeled onion next to a slice of bread in your refrigerator, the bread will not pick up the taste or odor of the onion. The onion’s flavor and odor are trapped inside the wrap. 

Saran resins for food contact can be extruded, coextruded or coated by a processor to meet specific packaging needs. About 85 percent of PVDC is used as a thin layer between cellophane, paper, and plastic packaging to improve barrier performance.

Saran Wrap Today

The Saran films introduced by the Dow Chemical Company are best known as Saran Wrap. In 1949, it became the first cling wrap designed for commercial use. It was sold for household use in 1953. SC Johnson acquired Saran from Dow in 1998.

SC Johnson had some concerns about the safety of PVDC and subsequently took steps to eliminate it from Saran's composition. The popularity of the product, as well as sales, suffered as a result. If you’ve noticed recently that Saran isn't much different than Glad or Reynolds products, that’s why.