Saran Wrap

Saran Wrap. It is a prominent brand of plastic film and plastic wrap used primarily for food preservation. Originally developed by The Dow Chemical Company, it became famous for its ability to cling tightly to surfaces and its early resistance to chemicals and moisture. The product's history is intertwined with major developments in polymer chemistry and the rise of consumer goods in post-war America.

History and development

The material was accidentally discovered in 1933 by a Dow Chemical researcher, Ralph Wiley, while working on a dry-cleaning product. Initially developed for military applications, such as protecting fighter aircraft from corrosion and as a spray for automobiles during World War II, its potential for food packaging was later realized. The brand was officially launched for consumer use in 1949, coinciding with the expansion of supermarkets and the rise of frozen food products like those from Birdseye. For decades, it was manufactured at a facility in Plaquemine, Louisiana, and became a staple in American kitchens, heavily advertised on programs like The Tonight Show Starring Johnny Carson.

Composition and properties

The original formulation was based on polyvinylidene chloride (PVDC), a polymer discovered by Dow Chemical scientists. This composition provided exceptional barrier properties against oxygen and aroma transmission, superior to films made from polyethylene or polyvinyl chloride (PVC). Its high cling was due to the inclusion of plasticizers, which allowed the film to adhere to itself and various surfaces like glass and ceramic. The material was also notable for its resistance to many chemicals and its ability to withstand a wide range of temperatures, making it suitable for use in both refrigerators and microwave ovens.

Production and manufacturing

Manufacturing involved the extrusion of the polymer resin into thin sheets, a process refined at plants like the one in Plaquemine, Louisiana. The production required precise control of temperature and pressure to achieve the desired thickness and clarity. For many years, the process was a closely guarded secret of The Dow Chemical Company. The finished product was then distributed on cardboard or plastic cores within iconic boxes, becoming a ubiquitous item on shelves at retailers like Walmart and Kroger.

Common uses and applications

Its primary use is covering food containers and wrapping leftovers to maintain freshness and prevent spoilage in home kitchens and commercial food service operations. Beyond food preservation, it has been used in arts and crafts, for protecting documents, and in temporary home repairs. In scientific laboratories, similar PVDC films are used for sealing experiments. It also sees use in horticulture for creating miniature greenhouses and in catering for presenting platters at events like those held at the Madison Square Garden.

Environmental impact and alternatives

As a single-use plastic, it contributes to issues of plastic pollution and challenges in waste management, as it is not typically accepted in curbside recycling programs due to its polymer composition. This has led to increased scrutiny from environmental groups like Greenpeace. Alternatives include reusable containers made of glass or stainless steel, beeswax wraps, and compostable films made from materials like cellulose. Many municipalities and countries are implementing policies, such as the European Union's Single-Use Plastics Directive, to reduce reliance on such products.

Safety and health considerations

Concerns have been raised about the potential migration of plasticizers, such as phthalates, and other additives into food, especially when used with high-fat content items or during microwave heating. While the Food and Drug Administration (FDA) regulates these materials as food contact substances, consumers are often advised not to let the film directly touch food during cooking. The Centers for Disease Control and Prevention (CDC) and agencies like the World Health Organization (WHO) monitor studies on long-term health effects of exposure to certain chemicals used in plastic production. Category:Plastics Category:American inventions Category:Food packaging