Abstract:
According to known methods for producing SiO2 blanks, successive layers of SiO2 particles are deposited, by means of at least one deposition burner, on the peripheral surface of a support that rotates about its longitudinal axis, thereby forming the porous blank. The support is then removed. The aim of the invention is to facilitate removal of the support and to thereby allow the production of an SiO2 blank (1) whose inner walls are as flawless as possible. To this end, a hard layer sequence (5) which comprises the first layer is deposited, said hard layer sequence (5) having a higher density than the successive layers (6). The inventive porous SiO2 blank is characterized by a core glass zone (2) of porous quartz glass that consists of a plurality of success layers and that is coaxially surrounded by at least one peripheral glass zone (3) of porous quartz glass. Said core glass zone (2) has an inner core glass layer (5) that comprises the innermost layer and an outer core glass layer (6), the inner core glass layer (5) having a higher density than the outer core glass layer (6).
Abstract:
According to a known method for producing a tube consisting of doped quartz glass, the starting components are fed to a deposition burner, particles containing SiO2 and GeO2 are formed, and are deposited on a mandrel rotating about its longitudinal axis, forming a porous layer of soot. Based on said method, the aim of the invention is to ensure that the doping agent is distributed over the tube wall in a radially homogeneous manner. In order to achieve this, an outer compression area (3) having a higher density is generated in the outer area of the layer of soot, and surrounds an inner area (2) of the layer of soot, said inner area having a lower density. A tubular semifinished product consisting of porous quartz glass containing GeO2, which can be subjected to dehydration treatment without significantly changing the predefined distribution of doping agent over the tube wall, is characterised in that the area of the outer wall of the tube is provided with an outer compression area (3) having a higher density and surrounding an inner area (2) having a smaller density.
Abstract:
The invention concerns a process for producing quartz glass bodies, wherein SiO2 particles are precipitated in layers on the cylinder jacket surface of a cylindrical support (1) that rotates about its longitudinal axis, thus forming an oblong porous green body (11). The SiO2 particles are produced in precipitation burners (2), electrostatically charged in an electrical field that is maintained between the surface of the developing green body (11) and the precipitation burners (2), and then sintered in the direction of the green body (11).