Market›Saran (plastic)
Company Profile

Saran (plastic)

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. 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. 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.

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, perchloroethylene. It was waterproof, strong and versatile; it could be rolled, forged, drawn, welded, stamped and blown. It was initially developed into a product when a division of General Motors requested a flexible film to prevent corrosion on machine guns shipped overseas. Dow trademarked "Saran" in 1940, but the company did not immediately develop the product commercially. In 1942, fused layers of original-specification PVDC were used to make woven mesh ventilating insoles for newly developed jungle or tropical combat boots made of rubber and canvas. These insoles were tested by experimental Army units in jungle exercises in Panama, Venezuela, and other countries, where they were found to increase the flow of dry outside air to the insole and base of the foot, reducing blisters and tropical ulcers. both employed by Dow Chemical Company, finished the last requirements needed for the introduction of PVDC, which was formulated in 1939 and monofilaments extruded initially. They also eliminated its green hue and offensive odor. A common folk etymology holds that "saran" was formed from John Reilly's wife's and daughter's names, Sarah and Ann Reilly. In fact, Dow researchers could not come up with sufficiently appealing names to market the product. Dow instead decided to use Firestone's name for plastic streetcar seats, and purchased the naming rights. Saran Wrap and other Dow consumer products were acquired by S. C. Johnson & Son in 1998. ==Formulation change to polyethylene==
Formulation change to polyethylene
Today's Saran Wrap is no longer composed of PVDC in the United States, due to cost, processing difficulties, and health and environmental concerns with halogenated materials, was made from polyethylene. However, polyethylene has a higher oxygen permeability, which in turn affects food spoilage prevention. For example, at and 95% relative humidity polyvinylidene chloride has an oxygen permeability of 0.6 cm3 μm m−2 d−1 kPa−1 while low-density polyethylene under the same conditions has an oxygen permeability of 2000 cm3 μm m−2 d−1 kPa−1, or a factor of over 3,000 times more permeable. For that reason, packaging for the meat industry still may use PVDC-containing films, as a barrier layer. ==References==
Source: Wikipedia ↗
tickerdossier.comtickerdossier.substack.com