Dielectric plasma chamber apparatus and method with exterior electrodes

Abstract

A dielectric barrier discharge plasma generator includes a dielectric chamber. The chamber contains or incorporates a solid surface that is to be treated with non-thermal plasma. The dielectric chamber can be substantially sealed and confine an atmosphere therein. An atmosphere control system is provided for controlling the atmosphere within the chamber. At least one or two electrodes are located outside of the dielectric chamber. When actuated by an appropriate source of plasma generating electrical power the electrodes cause the generation of a solid surface modifying non-thermal plasma in a plasma zone within the dielectric chamber. A transport system is provided for moving the electrode and the dielectric chamber relative to one another. A plasma zone is confined within the dielectric chamber adjacent to the electrodes, and remains substantially stationary relative to the electrodes. The dielectric chamber carries the solid surface through the plasma zone. The solid surface remains substantially stationary relative to the dielectric chamber.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention relates in general to methods and devices for applying a non-thermal plasma treatment to objects to change the object's surface characteristics, and, more particularly, embodiments of the present invention relate to treating solid surfaces in a substantially sealed dielectric barrier discharge plasma chamber system with exterior electrodes.[0003]2. Description of the Prior Art[0004]The use of non-thermal plasma to modify the surface properties of many solids for many different purposes is well known. Thermal plasma generators typically operate at temperatures where most metals melt or vaporize, so they are unsuitable for use with organic polymers, and the like. Non-thermal plasma treatment of the surfaces of objects changes the electrical charge, physical and / or chemical properties of the surface. Such properties include, for example, surface tension, biocompatibility, functionality, and the like. See, for...

AI Technical Summary

Benefits of technology

[0019]The present invention has been developed in response to the current state of the art, and in particular, in response to these and other problems and needs that have not been fully or completely solved by currently available non-thermal plasma generator systems and methods. The present invention effectively resolves at least the problems and shortcomings identified herein. In particular, embodiments of the present invention provide a dielectric barrier discharge plasma generator for the treatment of solid surfaces wherein at least a plasma generating electrode is positioned outside of and separately moveably from a substantially sealed dielectric chamber. The walls of the chamber comprise dielectric material to provide a dielectric barrier positioned between the electrodes and the workpiece. A workpiece is placed or occurs within the dielectric chamber. In various embodiments, the dielectric chamber and the workpiece may be one and the same, or the workpiece may be fully or partially enclosed within the dielectric chamber. A plurality of separate dielectric chambers may be provided. A gap is provided within the dielectric chamber in which non-thermal plasma may form. An atmosphere control system is provided to control the atmosphere within the chamber. A transport system is provide

Problems solved by technology

Thermal plasma generators typically operate at temperatures where most metals melt or vaporize, so they are unsuitable for use with organic polymers, and the like.

At high power settings, the surface of the workpiece may be etched or damaged.

Such systems are expensive to make.

Operating expenses are high because of the pumps, the maintenance, and the long cycle times, which tend to be in the order of several minutes.

Such systems are typically too expensive to build to fit one particular part.

A particular workpiece may not fit well in the chamber, so it does not receive a uniform surface treatment, or it may leave a lot of empty space in the chamber.

This empty space must be evacuated at considerable operating expense.

It is very hard to maintain a stable glow discharge between the electrodes i

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