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Different Kinds of Plastic Wrap

Plastic wrap is a clear, flexible product used in food packaging that clings to food containers and itself. It keeps food fresh and prevents food dehydration. Plastic wrap is made of synthetic polymers, which are large chains of small molecules. The production of household plastic wrap uses three kinds of polymers, each with its own properties. The use of plastic wrap has raised environmental concerns.

  1. Polyethylene

    • Imperial Chemical Industries of Britain discovered polyethylene in 1933, by mixing ethylene and benzene at a high temperature and pressure. Visking Corporation in the United States first made it into a film in 1945. Polyethylene evolved into two forms: low-density polyethylene, or LDPE, and high-density polyethylene, or HDPE. LDPE is used in the production of plastic wrap and it tends to be impermeable and naturally flexible, but it does not cling well.

    Polyvinyl Chloride

    • Polyvinyl Chloride or PVC was produced before World War II. Its first use was as a rubber substitute. It is made with either vinyl chloride or acetylene. In its normal form, it is rigid, but PVC wrap is chemically softened using a plasticizer known as phthalates. Polyvinyl chloride wrap clings well to dishes and itself, but it is not impermeable.

    Polyvinylidene Chloride

    • Dow Chemical Company developed Polyvinylidene chloride, or PVDC, during World War II for military use. In 1952, it was produced for the public under the name Saran Wrap. Saran Wrap was the first cling wrap designed for household use. This wrap is made from vinyl chloride and vinylidene chloride, and requires a plasticizer to soften it. PVDC wrap resists oxygen, water, bases, acids and solvents.

    Environmental Concerns

    • Plastic wrap is a single use petroleum-based product. It contributes to household waste because it is not recycled, and rarely reused. Concerns also exist about plasticizers used to soften plastics for wrap. The chemicals are absorbed into hot and fatty foods. PVC wrap is composed of as much as one-third plasticizers, and PVDC wrap uses about 10 percent plasticizers. Polyethylene wrap does not use plasticizers. Alternatives to plastic wrap include aluminum foil and reusable containers.

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