Functional PET Optical Film Coating Technology, AR Transmission Enhancement and Resistance Reduction Electrostatic Film

Release time:

2023-08-21

In recent years, optical grade PET polyester films have been widely used in the optoelectronic display industry. In the manufacturing process of liquid crystal display, PET type optical film is an indispensable material, such as diffusion film, brightness enhancement film, anti-glare film, anti-static film. This depends on the characteristics of PET optical film - high transmittance, low haze, high brightness, no yellowing, good adhesion, good flatness, no dark and bright lines, high temperature and UV resistance, good stiffness, anti-burning cracks, not easy to break and so on.

Functional PET optical film is mainly obtained by applying various functional coatings on the surface of PET polyester film. According to the function of the coating, it can be categorized into three types, i.e. protective coating, decorative coating and functional coating. By coating PET polyester film with different coatings, films with different functions can be produced.

For example, scratch-resistant, AR transmittance-enhancing and anti-static (106~1011Ω) coatings are coated on the surface of PET polyester film to make screen PET protective film, which is used to protect the surface of cell phone or computer screen; it can also be used as the process protective film for precision electronic components.

On the surface of optical PET, a layer of film with lower refractive index is plated by sol-gel method to increase the transmittance of PET, and the maximum transmittance of single layer and double-sided can reach more than 98%.

The multifunctional optical coatings independently developed and produced by WILO include transmittance-reducing anti-reflective coatings, transmittance-reducing anti-static coatings, and anti-bacterial fingerprint-resistant coatings, etc. The characteristics of transmittance-reducing anti-static coatings are as follows:

Product	Optimum film thickness	Transmittance Gain	Conductivity	Color
As960	（105±5）nm	6~8%	109~1011	Light blue-purple
AS975	（100±5）nm	5~7%	106~108	Nearly colorless
Double Layer	Primer:（105±5）nm Top coat: 50~80 nm	5~7%	106~108	Light blue-purple