Apparatus for atmospheric plasma treatment of a sheet-like structure

Abstract

An objective of the present invention is to provide a cylindrical, continuous plasma-processing apparatus capable of modifying the surface of a longitudinal substrate by a plasma process without the use of a vacuum, which has been required in the prior art. The cylindrical, continuous plasma-processing apparatus is comprised of, as a major portion, a hollow cylinder formed of a porous outer periphery wall made of ceramics, rubbers, or glass, a porous network electrode, and a dielectric inner periphery wall. The interior of this cylinder portion contains a metallic pipe whose surface is covered by a dielectric wall such that when a gas is introduced therein, the gas can be diffused into the cylinder portion through perforations. In a space between the cylinder portion and the metallic pipe, there is an antenna, the surface of which is covered by a dielectric. When a high voltage is applied to the antenna, and with the network electrode and the metallic pipe serving as ground electrodes, a plasma is generated between the antenna, the network electrode, and the metallic pipe. Due to the positive pressure created by the introduction of the compressed gas into the cylinder area, the plasma passes through all of the porous surfaces, including the outer periphery wall of the hollow cylinder. A substrate to be processed, such as a polyester film, is brought into contact with the outer periphery wall to effect surface modification of the substrate with the atmospheric pressure plasma.