Dielectric barrier discharge for film treatment

Dielectric Barrier discharges form the basis of corona process which find f requent application in the film and fibre industries. The discharge is crea ted between two electrodes in the inter-electrode space filled with a gas w hich is ionized by the application of a few kilovolts. One of the electrode s acts as a roller on which slides the material to be treated. As such, thi s process operated at the atmospheric pressure permits the material treatme nt directly on the production line. In order to avoid the formation of an e lectric are which would cause a very heavy damage to the material, a solid electrical insulator is introduced between the electrodes -hence the name o f Dielectric Barrier Discharge. This insulator also brings about an improve ment in the uniformity of treatment. As a matter of fact, the atmospheric p ressure discharges are made up of a multitude of micro-discharges of 100 mu m diameter which treat the material locally. This technology is being emplo yed for more than thirty years in order to increase the wettability and imp rove the polymer adhesion. Nevertheless, this has limitations due to the fa ct that the discharge is realized in air, that it is not uniform and that i t can only treat the material pieces in two dimensions. In the course of la st few years, the urgent need of specialized processes permitting surface c hemistry by limiting effluent production has induced a rapid evolution of p lasma technologies base on dielectric barrier controlled discharges. Recent ly, the concluding tests of sterilization by DBD have been carried out in l aboratories. The entire set of these points is given in this text.