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Plastic wrap, cling film (UK), cling wrap, food wrap, or pliofilm is a thin plastic film typically used for sealing food items in containers to keep them fresh over a longer period of time. Plastic wrap, typically sold on rolls in boxes with a cutting edge, clings to many smooth surfaces and can thus remain tight over the opening of a container without adhesive or other devices. Common plastic wrap can be roughly 0.5 Thousandth of an inch, or 12.5 µm, thick. Although as technology advances the trend has been to produce thinner thicknesses, particularly for household use (as not too much stretch is needed), so now majority of brands on shelves around the world have reduced to 8, 9 or 10 microns.
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Materials used
Plastic wrap was first created from polyvinyl chloride (PVC), which remains the most common material. PVC allows for permeability to water vapour and oxygen transmission. This permeability can add to the shelf-life or duration of peak freshness of the food products wrapped. There have been concerns about the transfer of plasticizers from PVC into food.
A common, cheaper alternative to PVC is low-density polyethylene (LDPE). It is less adhesive than PVC, but this can be remedied with the addition of linear low-density polyethylene (LLDPE), thereby also increasing the film's tensile strength.
In the US and Japan, there is production of plastic wrap using polyvinylidene chloride (PVdC), which is the main component of Saran wrap.