Chracteristic Of Dielectric Barrier Discharge In Atmospheric Pressure And Its Impact On Polymer Surface Modificaton

The research of Low-temperature plasma began in the 80's of 20th century. The current study of plasma technology is focusing on its use in various engineering applications. The atmospheric plasma technology can modify the physical and chemical properties of polymer surface without affecting the bulk properties of material. Since the whole process is energy efficient and does not produce any pollution, Low-temperature plasma technology is increasingly attracting attention in worldwide.In this paper, based on the applications of atmospheric pressure plasma, the laboratory designed a set of atmospheric dielectric barrier discharge plasma processing equipment which superior to most of the in-use equipments. It could discharge in a large area and perform to be uniform and can be applied to a various need of continuous processing. The diagnosis shows that the uniform dielectric barrier discharge process is mainly affected by change of power supply and reactive gas components. The electron energy will increase with the increasing plasma discharge power and thus cause the plasma discharge gradually appearing two rapid changes in the reaction area. It was found that those changes were caused by the exciting of oxygen and nitrogen components in the discharge area through electrical and optical diagnosis. Later, a discharge at 800w in argon environment and another at 600w discharge in argon / oxygen environment were considered as the best conditions for the plasma surface modification treatment.Subsequently, an atmospheric dielectric barrier discharge plasma treatment was used to the uniform surface etching of polyethylene terephthalate (PET) tire cord. The roughness of PET fiber increases while the chemical composition has also appears to be quiet different with the sample without treatment. As a result, the surface becomes hydrophilic and gets a better result in gum dipping process.Further analysis of the etching process and the chemical reactions on the interface between material surface and atmospheric plasma phase was investigated, compared with low-pressure discharge and atmospheric glow discharge. It shows that stream etching which impacted mainly with electric field in the discharge area occurs immediately while the oxidation progress is more time-related and be influenced with the components of reaction gas.In this paper, an investigation of plasma diagnosis and the process of surface modification as well as their relation have been indentified. Several hypotheses were put forward according to these conclusions. This experiment may help to afford better process control and substantiate mechanisms for plasma surface modification engineering.