PET film is a thermoplastic film with high transparency, good gloss and good air tightness. It is widely used in packaging, optics, building materials, medicine and other industries.

  PET film is a relatively polar film, and the surface tension of PET film without any treatment can reach more than 40 dynes. However, some inks are directly applied, and the adhesion is not ideal. A special treatment on the PET film is required to achieve better adhesion.

  Adhesion is fundamental to most properties of coatings, such as scratch resistance, water resistance, abrasion resistance and chemical resistance. There is no clear scientific explanation for the fundamental mechanism of adhesion. It is generally believed that substrates with high surface tension can form good adhesion. However, this theory is based on PET film. Among the commonly used plastic film substrates, PET film is the third most difficult substrate to adhere to after PE and PP.

  Corona treatment is a physical treatment method that forms fine cracks and effective functional groups on the surface of the film by high-voltage discharge. This treatment method is more effective on PET film and is the most commonly used treatment method. The corona-treated PET film not only greatly improves the surface tension, which is beneficial to wetting, but also greatly improves the surface roughness. For scenes with general requirements for adhesion, corona treatment is already very good. However, if the customer has particularly high requirements for adhesion, corona treatment cannot achieve the high quality requirements.

  UV hardening coating liquid is a kind of hardening coating which is cured by ultraviolet lamp. After coating a layer of UV hardening coating liquid on PET film and curing by ultraviolet lamp, it will form a layer of high hardness, transparent and anti-resistant on the PET film. scratched coating. The hardness of the PET film after UV hardening treatment will be greatly improved, thus extending its application scenarios.

  How to improve the adhesion of PET film?

  Therefore, many customers ask us why the adhesion is not good, and whether it is a problem with the quality of your film. In fact, the film itself is no problem, but the original film needs to be pretreated to achieve a more ideal effect.