Apparatus for plasma treatment of interior surfaces of hollow plastic objects

Abstract

An apparatus and method are provided for surface treating the inside surfaces of hollow or three dimensional plastic objects. While the invention will be described with respect to plastic objects, it will be understood that other objects having a high dielectric strength, such as ceramics, cardboard, paper and wood, may be similarly treated. The surface treating is effected by selectively directing a high voltage plasma field to a selected interior surface of the object to enhance adhesion of various glues, inks and the like. The plasma field is generated in the interior of a tunnel directed into an opening of the hollow portion of the object to be treated. A specially designed electrode is supported from the opening to direct in a controlled manner the field to the selected interior area of the object to be treated. The electrode is supported from a high dielectric shield covering a central area of the opening to direct the plasma field around the shield to a laterally extending electrode below the shield. The electrode is supported from the shield by a conductive rod and is fashioned to extend in a spaced relation to the interior of the object to provide a proper energy level in the plasma to the area to be treated. A plurality of electrodes may be utilized to treat separate and selected interior areas of the object.

Dependencies are inferred from the claim text.