BO PET film manufacture

The basic raw material for biaxial-oriented polyester films is polyethylene terephthalate in granulate form. Polymers often contain special additive types depending on the film type.
The manufacture of biaxial-oriented films is based on two physical processes:

  • Extrusion is a process consisting of transforming polymer into melt, moulding it to the required shape (in this case film) and cooling it below melting temperature.

  • Orientation is film drawing at melting temperature. In this process the film crystallises, which results in a change in its properties. Most importantly, high strength of the film is achieved and its ductility is reduced. The tensile strength properties of biaxial‑oriented films make them an ideal material for flexible packages, electrical insulating materials, bandages, separation layers and film-type sandwich structures – so-called laminates.


Both processes – extrusion and orientation – are completed in a single step, meaning the film has a favourable price and high use value.

BOPET film is manufactured in Fatra on 2 different production lines: Line A and Line B.

Line A Line B
film thicknesses
Film with
extruders
pouring head
6 – 50 µm (75 µm)
3400
2x two-screw
coextrusive A/B/A
23 – 150 µm
2200
1x single-screw
monoextrusive