DEVICES FOR MANUFACTURING ELECTRETS, AND ELECTRETS OBTAINED THEREBY

摘要

To manufacture a thin sheet electret of small size having charge distributed in very uniform manner, even at its edges, use is made of a device comprising a grounded electrode (2) for supporting a dielectric (1) to be charged, means for generating ions (3) in the vicinity of the dielectric, a grid (4) extending parallel to the surface to be charged of the dielectric, at a small distance from said face, and raised to an electric potential different from ground potential and a conductive frame (7) that is insulated from the electrode and that is electrically connected to the grid, said frame surrounding the dielectric and forming a single block with the electrode.