Effect element for printing PET Film
BOPET film with excellent performance, polyester film has high mechanical strength, good optical properties, high temperature resistance, excellent barrier properties, oil resistance, corrosion resistance, etc., so its application is very widely.PET film can be used in the printing, lamination, vacuum aluminum metallizing and other application .
However, for high-speed, light-screen printing, the BOPET film has to be with certain requirements for surface properties in order to increase the fastness of the printing ink and to increase the adhesion of vacuum aluminized aluminum because these surface properties affect the BOPET film’s Printing and metallizing effect.
Here we would like to discuss about the surface wet tesnion of the PET Film for printing and metallizing, for reference purposes only.
Without treatment BOPET film
BOPET film without treatment, the surface wet tension could be 38 dynes or more, but in order to further improve the printing ink or metallzing .it is better to increase the PET film surface wet tension to have a better adhesion for the ink and metal.
PET film surface treatment methods
PET film surface treatment methods are: corona treatment, chemical treatment, coating, etc, the most commonly used is the corona treatment &chemically treatment,we called chemically treated pet film
Corona treatment method is based on the principle: by the metal electrode and the corona treatment roller (usually high temperature, ozone resistant, high insulation silicone rubber roller) between the high frequency, high voltage power supply, so that the discharge, so that Air ionizes and forms a lot of ozone.
At the same time, high-energy sparks strike the surface of the film. Under their joint action, the plastic film surface is activated and the surface energy is increased. The corona treatment can make the surface tension of BOPET film reach 52 ~ 56 dynes or even higher.
Chemically Coated pet film
Chemically Coated pet film is another effective way to improve the surface properties of BOPET films. The so-called coating method is coated on the film surface layer of a polymer , such as acrylates, copolyester and other polymer solution coating.
After chemically coating on the pet films,it has a strong adhesion, can standard a high temperature and . Good fit for printing ,lamination and metallizing.
Normally,Chemically coated pet film has a better performance than corona treated pet film in printing and metallizing application and cost higher.