Polyvinylidene
chloride
Polyvinylidene chloride (PVDC)
was developed by Dow Chemicals in the 1930s and
marketed under the tradename Saran. PVDC has a
very low permeability to moisture and other gases
and is resistant to chemicals and
solvents. It was initially used as a protective
coating to combat corrosion on military aircraft
exposed to sea spray.
After the war it enjoyed a
brief spell as monofilament and fibres in heavy
textiles, ropes and car upholstery, exploiting
its resistance to chemicals, but it soon found
application as a film for wrapping food. Cling
film - as it came to be known - was introduced
for commercial use in 1949 and for domestic use
in 1953.
Nowadays, it is mostly used as
a thin barrier layer in multilayer sheet, film
and tube - generally produced by co-extrusion
with other polymers such as polyolefins or
polystyrene but also laminated with cellophane,
paper or board.
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