Method for producing ultra-high purity, optical quality glass articles
AssigneeDegussa AG
InventorsMonika Oswald, Gerrit Schneider, Jürgen Meyer
Life of this patent
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Abstract
A method for producing ultra-high purity, optical quality, glass articles is disclosed which involves: 1. compacting metaloxide or metalloidoxide to granules having a mean particle size of less than about 1 millimeter; 2. optionally fully sintering the granules to produce high purity, artificial sand; 3. casting the artificial sand by conventional techniques, such as, slip casting, to form a high density, porous, green body; 4. optionally drying and partially sintering the green body; 5. optionally fully sintering the green body under vacuum; and 6. optionally hot isostatic pressing the green body.
Claims8
A method for producing a fused glass article comprising the steps of:
- a) compacting pyrogenically produced metaloxide or metalloidoxide to form granules having a mean particle size less than about one mm;
- b) forming a green body from the granules or mixture of the granules according to step a) using a technique selected from uniaxial, cold isostatic or hot isostatic powder pressing, slip casting, extrusion, moulding or injection moulding;
- c) drying the green body in a first chamber by raising the temperature of the first chamber to above about 1000° C.;
- and
- d) fully sintering the green body in a second chamber by raising the temperature of the second chamber within a temperature range from about 1,200° C. to a temperature above about 1,720° C.;
- and
- e) hot isostatic pressing the fully sintered green body in a third chamber by raising the temperature of the third chamber to above about 1,500° C. and introducing an inert gas into the third chamber at a pressure above about 100 psig (6.895 bar).
A method for producing a fused glass article comprising the steps of:
- a) compacting pyrogenically produced metaloxide or metalloidoxide to form granules having a mean particle size less than about one mm;
- b) sintering the granules at a temperature less than about 1,100° C., resulting in granules having a density approximately equal to their maximum theoretical density;
- c) forming a green body from the granules or mixture of the granules according to step a) using a technique selected from uniaxial, cold isostatic or hot isostatic powder pressing, slip casting, extrusion, moulding or injection moulding;
- d) drying the green body in a first chamber by raising the temperature of the first chamber to above about 1000° C.;
- and
- e) fully sintering the green body in a second chamber by raising the temperature of the second chamber within a temperature range from about 1,200° C. to a temperature above about 1,720° C.
Dependencies are inferred from the claim text.