Thin film surface energy, also known as surface tension, an index is a measure of ability to accept ink. Film printing requires film 38dyn/cm is the smallest accept ink to the surface tension due to surface tension inherent in the existing film material are lower than the resin, so in order to film to firm to accept ink and must do some processing on the surface, thin film surface in print will have enough energy. Commonly used surface treatment consists of the following three ways:
1. corona treatment methods: via a high voltage charge to surface discharge, in the presence of ionizing the surface roughening and surface energy, increasing the combined capacity of the film surface and ink;
2. surface coating: in the process of making labels coated with a special coating, so as to improve the film's surface tension;
3. printing process: in the film production process using a special process, through chemical processing method to improve the characteristics of thin film surface in order to increase the adhesion of inks and films.