Air-to-air atmospheric pressure plasma treatment – perspective for composite manufacturing

Fibre-reinforced polymer composites are gaining increasing attention in various applications for constructing mechanical structures such as wind turbine blades. The interface between fibres and a polymer matrix should be optimally designed to promote the mechanical performance of the composites. Plasma treatment shows obvious advantages over conventional approaches, since it has the characteristic of environmental friendliness, low-cost, and easy operation. A plasma can be favourably generated at atmospheric pressure. One of the most commonly used atmospheric pressure plasmas is a dielectric barrier discharge (DBD). In the present work, an air-to-air DBD is introduced. The DBD was generated in a gas mixture of helium and fluorocarbon between a rod-shaped water-cooled powered electrode covered with alumina and a one-dimensionally movable ground aluminium plate. Polyethylene terephthalate films were used as model specimens, and attached on the aluminium plate for the surface modification. The results indicate that specimen surfaces can be oxidized or fluorinated, depending on the conditions, and that the gap between the electrodes and gas flowrates significantly affect the treatment effect.