PE and PVC films used in fresh
food packaging as well as green houses, often
turn opaque and lose clarity when moisture gets
trapped inside the films. Special additive systems
are required to prevent condensation of water
droplets. Compared to the surface treatment,
the dosing of additive in the material is more
effective and more long lasting. They certainly
enhance the attractiveness of packaging systems
and also increase the shelf life of the package.
Antifogging additives are typically surface
active agents that have both hydrophilic as
well as lipophilic parts. Typically Sorbian
esters, polyoxyeytthylene esters, glycerol esters
have so far been effectively used as antifogging
agents. Polyglycerol esters is a new family
of antifogging agents that have been introduced
by Solvay S.A. These are biodegradable and very
efficient because of low content of residual
glycerol. They are in liquid form and are colourless
and maintain the clarity and colour of the basic
polymer. One of the major advantages of these
new products is their controlled migration,
which provides longer life to the film, making
them more effective for a longer time. Some
of the typical products are based on lauric
acid or oleic acid.
These agents can also provide antistatic properties
in addition to their antifogging characteristics.
