High‐speed plasma treatment of polyethylene terephthalate films using ultrasound assisted dielectric barrier discharge

摘要

Abstract Polyethylene‐terephthalate (PET) films were treated using an air‐to‐air type atmospheric pressure dielectric barrier discharge (DBD) plasma in helium with ultrasonic irradiation, particularly for aiming at improving wettability. Airborne ultrasound was irradiated to the plasma using a pneumo‐acoustic stem‐jet Hartmann's generator. The wettability was significantly improved even when the treatment speed was up to 300?mm/s, corresponding to an estimated exposure time of approximately 30?ms. It is at least a factor of 30 shorter than the time required to achieve the same level of plasma treatment effect without ultrasonic irradiation. This effect opens an opportunity for industrial implementation of high‐speed plasma treatment of PET flexible packaging films by a straightforward embedding of pneumatic generators of ultrasound into existing wide‐web roll‐to‐roll commercial machines based on DBD.