FLANGE MADE OF QUARTZ GLASS AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To provide a flange made of quartz glass which has excellent heat shieldability and sealability, is foamless and has a high density and a process for producing the same. SOLUTION: This flange made of the quartz glass is formed of laminar quartz glass laminated with plural transparent quartz glass layers in a layer form. The density of the flange is specified to >=2.18g/cm<3> and the surface roughness of the sealing surface of the flange to <=0.5μm Ra and <=5μm Rmax . This process for producing the flange made of the quartz glass comprises grinding the laminar quartz glass obtd. by depositing soot-like silica particulates formed by hydrolyzing as silicon compd. in a flame in a laminar form on a target and subjecting these particulates to a heat treatment at 1300 to 1500 deg.C to form into a flange shape.