
Polyethylene
terephthalate is a semi crystalline polymer used to produce films. Two
different film materials PET and PET2 are used to make this film.
PET films are biaxially oriented to stretch the polymer chains creating
strength, then heat quenched to lock in the structure with a small
percentage of polymer crystallization. The heat quenching conditions may
leave a residue on the film that may be relieved with later heat
treatment. These films have good thermal stability. They can be
post-processed in the form of sheet or roll, to have better thermal
dimensional stability. They are subject to shrinkage over long periods
of time due to stress relaxation.
They act as barrier to high oxygen, moisture, and aroma. They have one
disadvantage of getting degrade in sunlight unless they contain
ultraviolet inhibitors. They exhibit good water vapor and oxygen gas
barrier properties.
Applications: PET Films and Packaging
PET films find a wide range of applications in magnetic tapes,
photographic films, photoresist and hot stamping foils in addition to
packaging outlets. This film finds it use in print lamination with CPP
or PE, frozen foods like vegetables and meats and sterilized bags. It
also finds its use in PU skin, PVC tiles, PC boards and other plate
films, laser decorations and insulation covering.
The excellent thermal properties of PET allow processing and use over a
wider temperature range than most common packaging films. It is ideal
for retort packaging, dual ovenable lidding and boil in the bag
applications. PET film has the chemical inertness and good gas barrier
properties that are important for many medical, pharmaceutical and food
products. They can be used in the demanding steam, ethylene oxide and
radiation sterilization processes.
PET films are used to make various packaging products like packaging
pouches, packaging bags, aluminum foils, dairy packaging, pharma
packaging etc.