Patent ID: 7111476
Filing Date: 2006-09-26
Classification: C03B

Abstract:
1. An electrophoretic deposition process for making quartz glass products comprising preparing an aqueous slurry consisting essentially of high-purity micronized silica particles and water, providing said silica particles with a negative electrical surface charge sufficient to provide electrophoretic mobility, providing negative and positive electrodes in contact with said slurry, said electrodes having associated means for separating and removing excess water from the slurry, the positive electrode having an electrically conductive portion providing a shaping surface, said slurry being electrically conductive and substantially free of contaminating metallic ions, maintaining said particles in suspension while controlling the water content of the slurry adjacent to the electrodes, causing the charged silica particles to be deposited at the positive electrode to form a porous silica body of substantial thickness on said shaping surface, separating the silica body from the shaping surface and drying and firing the silica body, the solids content of the slurry adjacent the shaping surface being maintained at about 80 percent by weight or higher during the electrophoretic deposition.