Characteristics of Coaxial Dielectric Barrier Discharge at an Atmospheric Pressure with a Swirling Gas Argon/Oxygen Mixture for the Surface Modification of Polyester Fiber Cord

A newly developed coaxial dielectric barrier discharge reactor with a length of 1000 mm at an atmospheric pressure was used for plasma treatment of polyester fiber cord in a roll-to-roll manner. In this reactor, swirling mixture gases of oxygen of about 1% and argon with a flow rate of 1.5 to 2.7 L/min ensured the gas usage sparing, discharge uniformity and efficient fiber surface modification. The water contact angle and surface morphology of the treated fiber were measured. The results show that the surface oxygenation is mainly responsible for the wettability improvement of the fiber cord when passing through the plasma zone at a linear speed of 3 to 8 m/min. The specimens of modified-polyester fiber reinforced rubber composite were also prepared for the interfacial shear strength tests. Furthermore, the effect of adding oxygen into argon discharge on the fiber surface oxidation was correlated with optical emission spectroscopy. Finally, the effect of adding oxygen into argon discharge on the kinetic processes of the active species generation were also analyzed.