Study on the surface microstructure preparation process parameters of PET based on ultrasonic embossing technology

Ultrasonic embossing technology has been applied to pattern the functional microstructure on the thermoplastic polymer material surface just in recent years. To investigate the influence of the process parameters within the ultrasonic embossing on the microstructure forming performance, an ultrasonic embossing platform is developed based on an ultrasonic welding machine. A metallic mold with pillared rectangular microstructure on its surface was fabricated using the femtosecond laser. The length, spacing, and depth of the pillared rectangular element are respectively 90, 150, and 45µm. A series of ultrasonic embossing trials were carried on a 1.0 mm thickness PET film. According to the experimental results, it is found that the ultrasonic pressure, welding time, holding time and ultrasonic amplitude all have significant effects on the replication depth, among which the ultrasonic amplitude is the most influential factor. However, when the holding time reaches a certain value, its effect on the replication depth changes small.