Polyester film, is a polymer resin of the polyester family. Sometimes known as PET (polyethylene terephthalate). polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties, and electrical insulation.
The manufacturing process begins with a film of molten polyethylene terephthalate (PET) being extruded onto a chill roll, which quenches it into the amorphous state. It is then biaxially oriented by drawing. Once the drawing is completed, the film is "heat set" or crystallized under tension in the oven at temperatures typically above 200 °C (392 °F). The heat setting step prevents the film from shrinking back to its original unstretched shape and locks in the molecular orientation in the film plane.
polyester films are thermally stabilized at 150°C for 30 minutes (MD/TD shrinkage at <1%) to ensure proper registration and performance of silver conductive inks.
polyester film is a high clarity film with one side pre-treated to promote adhesion to most printing inks and industrial coatings.
polyester films can serve as the printing shorting pad layer and the bottom circuit in Flexible Electronics applications, including membrane switch circuitry.