Powder treating method and apparatus used therefor

Abstract

The powders such as pigments are treated with the low temperature plasma so that their chemical property is improved. In low temperature plasma treatment, if a plurality of powders coagulate into one lump, or if powders cohere on the vessel's inside wall surface, it is difficult to make uniform and efficient treatment. The present invention provides a powder treating method and apparatus used therefor which make uniform and efficient treatment of powders with low temperature plasma. The first invention is a powder treating method where the powders are treated with low temperature plasma while stirring them by vibration. The second invention is a powder treating apparatus equipped with a treating chamber for housing powders, a device for vibrating this treating chamber and a plasma producing device, in which the powders in the treating chamber are treated with low temperature plasma while stirring them by vibration. While the treating chamber is formed by upper and lower two vessels with their opening mated to one another. An insulator is provided at a junction between these two vessels so as to electrically insulate the upper and lower two vessels, so that these two vessels may be utilized as mutually facing exciting electrode and grounding electrode. The third invention is a powder treating method where the powders are treated with low temperature plasma while being stirred by a precessional movement of a spiral screw which is being rotated.